UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Some Devonian brachiopods reported from western Canada Fortescue, John Adrian Claude 1954

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1954_A6_7 F6 S6.pdf [ 22.28MB ]
Metadata
JSON: 831-1.0053561.json
JSON-LD: 831-1.0053561-ld.json
RDF/XML (Pretty): 831-1.0053561-rdf.xml
RDF/JSON: 831-1.0053561-rdf.json
Turtle: 831-1.0053561-turtle.txt
N-Triples: 831-1.0053561-rdf-ntriples.txt
Original Record: 831-1.0053561-source.json
Full Text
831-1.0053561-fulltext.txt
Citation
831-1.0053561.ris

Full Text

SOME DEVONIAN BRACHIOPODS REPORTED FROM WESTERN CANADA  by John Adrian Claude Fortescue  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN THE DEPARTMENT OF GEOLOGY AND GEOGRAPHY  We accept this thesis as conforming to the standard required from candidates for the degree of Master of Science*  Members of the Department of Geology and Geography.  University of British Columbia Vancouver, B.C., Canada. April, 1954.  ABSTRACT *  I.  The aim of thia study waa to compile a l i s t of descriptions of genera and species of brachiopod fossils which have been reported by various authors from the Devonian rocks of Canada, West of the 110th meridian. This thesis i s divided into two parts. essentially bibliographical.  The f i r s t part i s  The second part contains descriptions of  genera and species of brachlopods. The bibliography i n Part I contains forty references from which brachiopod faunal l i s t s were compiled. Part I also contains an index map showing the geographical location of outcrop areas from which the fossils were collected, and a chart showing the stratlgraphic range of brachiopod genera i n a typical Devonian section of the Southern Rocky Mountains. In Part II, the brachiopod faunal l i s t s have been arranged in a systematic manner. They are supplemented by detailed descriptions of fifty-one genera and ninety-eight species.  The descriptions are  prefaced by a short discussion of biological classification; on the modern concept of species;  a glossary of brachiopod  and a short l i s t of important references  a note terminology,  on this group of f o s s i l s .  A l l the descriptions are taken from the literature on the subject because none of the type material is presently at the University of British Columbia.  The brachiopod descriptions are arranged by  superfamilies. Conclusions are drawn regarding the scope and limitations of this study.  Some suggestions are offered for the further study of  this group of f o s s i l s .  INTRODUCTION  II.  Many reports have been written during the past eighty-five years on the geology of Canada, west of the 110th meridian.  In most of these  reports reference i s made to Devonian rocks and f o s s i l s . Brachiopod fossils are very abundant, both i n species and i n numbers, i n certain beds of these Devonian strata.  The brachiopod  faunas include species which have been reported from Devonian rocks i n other parts of the world, and species that are peculiar to Western Canada. There exists today no work of reference i n which the f o s s i l brachiopods from Western Canada are described i n detail.  The descrip-  tions of these fossils are scattered through the literature on the geology of Western Canada, and that describing the Devonian strata of other parts of the world.  This thesis brings some of these descrip-  tions together i n a systematic manner. Unidentified f o s s i l collections are of l i t t l e use to a geologist. Correctly identified fossils can further geological enquiry along three main lines. F i r s t , i f a given species i s identified i n a f o s s i l collection from a given locality, this information w i l l further knowledge of the geographical distribution of that species. Second, a species may indicate the presence of a given faunal zone within a stratigraphic section. Third, the detailed morphology of a species may suggest genetic affinities between i t and other morphologically similar species.  The  accurate identification of the various species i n a collection i s therefore very important. Three stages may be distinguished i n the identification of a  fossil.  These are:-  III,  (a) Collection of fossils from a specific locality and horizon. (b) Sorting fossils into their various phyla. (c) Specific identification of individual f o s s i l s . This thesis i s compiled as an aid to the specific identification of brachiopodB from the Devonian rocks of western Canada, A collection of these f o s s i l s , made by Dr. Okulitch during the f i e l d seasons of 1950 and 1951, 1B at present unidentified at the University of British Columbia.  The author considered that a compilation  of descriptions i s prerequisite to the systematic study of the collection. It i s hoped that this thesis w i l l f a c i l i t a t e the identification of brachlopods i n the collection.  IV.  ACKNOWLEDGMENTS  The author would like to express his sincere thanks to Or. V. J . Okulitch, Professor and Chairman of the Division of Geology in the University of British Columbia, for his constant encouragement and constructive criticism of the work ae i t progressed. Thanks are also due to Mr. A. Tomlinson and other members of Geology $21 class last year, for allowing the writer to use some of the specific descriptions of brachiopods compiled by them during the course. Finally the author would like to express his appreciation to Miss E. McDonald who has spent many hours typing the manuscript of the thesis.  TABLE ABSTRACT.  OF  CONTENTS.  PAGE.  ••  I.  INTRODUCTION.  ••  •  —  -  I  I  ACKNOWLEDGMENTS : PART I  .  IV.  Sources and General Palaeontology*  - — — —  Introduction.-——-  —  Stratigraphic Chart. Bibl i ography •  . _ i . —  —  —  — —  —  i  .  ——4.  —  PART II Systematic Palaeontology.—--  —  •—  —  —  6• 10.  Introduction. a) Biological and Palaeontological Classificatiorw-10. b)  Classification of Phylum B r a c h l o p o d a . — — — — 1 2 .  Glossary of Brachiopod Terms.  —  15.  Systematic Lists and D e s c r i p t i o n s . — — — — — - — — 2 J . a) Description of classes, orders and superfamilies.25. b) Systematic l i s t s of genera and species. I] Layout of generic d e s c r i p t i o n s . - — — — — —— —— -- 22 5? .. Layoutof ofPhylum specific d e s c r i p t i o n s . — — - — — — 225. 5. Classification Brachlopoda.  ——26.  Class I n a r t l c u l a t a — Order Atremata — — —— Superfamily Lingulacea — Genus Lingula — Order Neotremata — Superfamily Oranlaea Genus Crania —  —  —  Class Articulata — Superfamily Dalmanellacea — Genus Aulacella — Carinlferella • Phlpidomella Schizophoria - — — — n  0  Superfamily Pentameracea  —  —  ...... •  — — — 2 6 . — •- • - ---26. 27. — — 2 8 , —-———28. ...... .—29.  — — — — — 5 0 .  — — — — — J l . •. • —.52. — 5 5 . 54. — — — — 5 6 •  ••  — — — — — — — 5 9 *  Genus Gypidula PentameruB  40. 42.  0  Sup erf ami ly Str ophomenac eaGenus Douvillina Douvillanaria Leptaena Leptoatrophia " Nervo atrophia Schuchertella " Strapheodonta " Strophonella  <— — —  —  44. 46. 48. —-51. -55. 54. 57. —60. 65.  0 n  n  0  Superf amily Ohonetacea—— Genus Chonetes— — Chonopectus  ———70.  — — — —  —  —71 • 75.  n  Superf amily Productacea Genus Devonoproductus— • Productella " Strophalosia  •  —  Sup erf amily Rhynchonel 1 a c e a — Genus Calvinarla— Oamarotoechia-——— • Etonia " Hypothyridlna " Leiorhynchus— — — Paurorhyncha — Pugnax • Pugnoldes— n  0  n  D  Sup erf ami ly Atrypacea Genus Atrypa: • Grunewaldtia— Superf amily S p i r i f e r a c e a — Genus Ambocoelia 0 Ambothyris-— Athyrls ChorlstltesCrurlthyris— Cyrtia Cyrtina CyrtiopsisCyrtospirlfer Eleutherokomma— Elytha Martlnia Mart lnop sisMeristella— Platyrachella  —  ——85. — —-86. ———-——.-38. 92. 95. — -95. 100. 101. — — 105. — — — — — — —  —  —  74. 76. 78. 82.  —  106 . ——108. 116.  •— 117. —————125. —155 • 125. 155. — 155. 128. 128. 155. 155. ———————155. 15J. , 154. —154. — -157 • 159.  153. U4O. 15U. lltf. 151.  Genus Reticular! a Spirifer Tenticospirifer » Tylothyris " Warrenella n  n  Superfamily Genus " " n  Terebratellacea Cranaena Cryptonella Rensselandia Stringocephalus  CONCLUSIONS SELECTED BIBLIOGRAPHY  '  —  159 • 160. '• 162. 16L« 166. 168. 170.  PLATES Plate I Superfamily DALMANELLACEA  180  Plate II Superfamily PENTAMERACEA Superfamily STROPHOMENACEA  181  Plate III Superfamily STROPHOMENACEA (continued)  — — 182  Plate 17 Superfamily PRODUCTACEA Superfamily CHONETACEA Superfamily RHYNCHONELLACEA  183  PLATE V Superfamily RHYNCHONELLACEA (continued) Superfamily ATRYPACEA  18U l8lj  Plate VI Superfamily SPIRIFERACEA  •  185  Plate VII Superfamily TEREBRATELLACEA  186  PART  I  1 #  INTRODUCTIOH This part of the thesis deals briefly with the general  palaeontology  of the brachlopoda of Western Canada, and includes a bibliography of forty-three papers i n which the Devonian rocks of Canada, west of the 110th meridian, are discussed.  The general palaeontology i s divided  into two parts; the geographical distribution, and stratigraphical distribution of the brachiopod faunas.  The former i s illustrated by  means of an index map, and the latter by means of a chart. The Index Map. The Index map consists of an outline map of Western Canada on which the outcrop areas of Devonian rocks covered by this survey have been indicated. Numbers on the index map refer to papers listed i n the bibliography at the end of this part of the thesis. The numbers indicate the approximate location of the outcrops which were studied by the authors of papers cited i n the bibliography. Some of the papers are themselves compilations, and therefore could not be Indicated on the map because the fossils listed i n them were oollected from several different l o c a l i t i e s . The paper by Warren and Stelck (1950) 1B an example of a report of this type. The Stratigraphic Chart. The Information on this chart was taken from the paper by de Wit and McLaren (1950). The chart indicates the stratigraphic range of common brachiopod genera i n a type Devonian section i n the Southern Rocky Mountains.  130*  I2t*  122*  IIS*  ||4«  no*  106*  Two facts are apparent from the chart* First, that the most varied brachiopod faunas are to be found i n the central part of section i n the Mount Hawk and Alexo Formations. Second, that a stratigraphic break i s indicated by the total absence of brachiopod fossils i n the top beds of the Mount Hawk formation* This chart i s included here as an example of the varied stratigraphic range of common brachiopod genera i n an outcrop area of the Devonian rocks of Western Canada* References. The references i n the bibliography are numbered i n chronological order, commencing with the paper by Meek (1869), which i s numbered ( I ) , and ending with that by Crickmay (1955) which i s numbered ( 4 j ) . The papers were numbered i n this way for two reasons.  First, to avoid  constant repetition of authors' names and dates i n the systematic faunal l i s t s i n Part II of this study, and second, to f a c i l i t a t e quick reference to the papers. The author considers that the forty-three papers listed i n the bibliography, are representative of paperB written on the Devonian rocks of Western Canada, during the past eighty-five years. Faunal l i s t s of two papers which were written during the last century are included*  One paper i s by Meek (1869), in which he describes new  Devonian brachiopod species which had been collected from the Mackenzie River area during Kexmicott's last expedition.  The other paper i s by  Whiteaves (1891), who describes a l l the Devonian fossils from the Mackenzie River basin, which were at that time i n the collections of the geological survey of Canada. Detailed papers recently published on the subject were written by  A GENERALIZED STRATIGRAPHICAL COLUMN OP TBE DEVONIAN ROCKS IN THE SOUTHERN CANADIAN ROCKIES, SHOWING THE STRATIGRAPHIC RANGE OF THE VARIOUS BRACHIOPOD GENERA IDENTIFIED FROM THE ROCKS. (AFTER DE WIT AND MC LAREN 1950). MISS.  DEVONIAN  AGE  PALLISER FLUME  150  PER- MOUNT ALDRIX HAWK SXO  MORRO  600 580'  950»  1  •  *  —*  DIVISIONS.  95'  GENUS  — *  •  *—*  *-* *• *•  *.  •  *  — *  *—*  *  *"**  •  — *  *  — * — *  *—• *-*  •  — *  *— — *  «  *-  **—  •  —*  * • **  STRATIGRAPHIOAL  COSTI- EXGAN SHAW  — *  -  CAMAROTOECHIA  cfil-  PAURORHYNCHA  -  PUGNOIDES  2  LEIORHYNCHUS  5  LINGULA  -  SCHIZOPHORIA  5  n  STROPHOEODONTA"  6  "SCHUCHERTELLA"  2  CHONETES  5  PRODUCTELLA  11  ATRYPA  11  GRUNEWALDTIA  2  OYRTOSPIRIFER  5  TENTICOSPIRIFER  1  ^SPIRIFER'  8  "MARTINA"  5  'CYRTINIA^  1  'ATHYRls'  4  GYPIDULA  2  5. Warren (1949), Warren and Stelck (1950), Crickmay (1952), and de Wit and McLaren (1950)* A l l the papers which are listed i n the following bibliography are at present i n the library of the University of British Columbia, with the exception of that by Meek (1869), which was secured on inter-library loan from the University of Michigan.  6. STRAT7JGEAFHIC REFERENCES FROM WHICH THE LISTS OF BRACHIOPGDS WERE TAKEN.  (1) MEEK, F.B. (1869).  "Remarks oa the Geology of the valley of Mackenzie River with figures and description of f o s s i l s from that region i n the Museum of theSmithsctnian Institution chiefly collected by the late Robert Kennicott, Esq." Trans.Chic.Acad. S c i . Vol. I. p. 61-llU.  (2) WHTTEAVES, J.F. (1891).  "The Fossils of.the Devonian rocks of the Mackenzie River Basin". Geol. Surv. Can. Cont. to Pal. Vol. I. Pt. 3. No. 5* p. 197-253*  (3) SHINER, H.W. (1911).  "Lake Minnewanka Section". Geol. Surv. Can. Summ. Rept. 1911,  p. ll»5.  (U) SHIMER, H.W. (1913).  "Spiriferoids of the Lake Minnewanka Section Alberta." Bull. Geol. Soc. Amer. Vol. 2k, pp.233-2l|9.  (5) CAMERON, A.E. (1917).  "Explorations i n the v i c i n i t y of Great Slave Lake." Geol.Surv. Can. Summ. Report. 1917, Pt. C , pp. 21r28.  (6) CAMSELL, C. and WTATT, M. (1919).  "The Mackenzie River Basin". Geol. Surv. Can. Mem. 108..  (7) KINDLE, E.M. (1919). . .. "Discovery of a Portage Fauna i n the Mackenzie River Valley." Geol. Surv. Can. Mus. Bull. 29, p. 1.  (8) CAMERON, A.E. (1921). "Hay and Buffalo Rivers, Great Slave Lake and adjacent Country". Geol. Surv. Can. Summ.Re port. 1921, Pt. B. pp.l-Ui*  (9) HUME, G.S. (1921).  "North Nahanni and Root Rivers area and Cariboo Island Mackenzie River d i s t r i c t . " Geol. Surv. Can..Summ. Rept. (1921) Pt. B. pp.67-78.  (10) WHITTAKER, E.J. (1921). "Mackenzie River District between Great Slave Lake and Simpson". Geol. Surv. Can.Summ.Rept. (1921) pt. B. pp. U5-55*  (11) WILLIAMS, M.T. (1921). "Exploration East of Mackenzie River between Simpson and Wrigley". Geol. Surv. Can.Summ. Rept. (1921) Pt. B., pp.56-66.  7. (12) HOME, G.S. (1922). "Geology of the Norman o i l f i e l d s and a reconnaissance of a part of the Liard River"* Geol. Surv. Can. Summ.Rept. (1922), Pt. B., pp. 1*7-6)*. (13) SHEPARD, F.P. (1922). "Problems inStratigraphy along the Rocky Mountain Trench". Jour. Geol. Vol. XXX. p. 367* (Iii) KINDLE, E.M. (1921*). "Standard Palaeozoic section ofRocky Mountains near Banff, Alberta." Pan. Amer. Geol. Vol. XLII, p. 113* (15) W&LCOTT, CD. (1921*). "Geological Formations of Beaverfoot-Brisco Stanford Range, British Columbia." Smith Misc. Coll..Vol. 75, No. 1, p. 32. (16) WALKER, J.F. (1926). "Geology and Mineral Deposits of Windermere Map area, British Columbia." Geol. Surv. Can. Mem. 11*8. (17) SHIMER, H.W. (1926). "Upper Palaeozoic faunas of the Lake Minnewanka section, near Banff, Alberta." Geol. Surv. Can. Bull. 1*2, pp. 1-81. (18) WARREN, P.S. (1927). . . "Banff Area, Alberta." Geol. Siav. Can. Mem. 153* (19) KINDLE, E.M. (1928). "The occurrence and correlation of a Devonian fauna from the Peace River, Alberta." Geol. Surv. Can. Bull. 1*9, p. It*. (20) WARREN, P.S. (1928). "The Palaeozoics of the Crowsnest Pass, Alberta." Trans. Roy. Soc. Can. Vol. XXII, Pt. 1, Sec. IV,.p. 109* (21) KINDLE, E.M. (1929). "The Succession of Fossil Faunas i n the east part of Jasper Park." Amer. Jour. S c i . Fifth Ser. Vol. XVII, p. 186. (22) ALLAN, J.A., WARREN, P.S. and RUTHERFORD, R.L. (1932). "A Preliminary Study of the Eastern Ranges of the Rocky Mountains in Japser Park, Alberta." Trans.Roy. Soc. Can. Third Ser. Vol. XXVI, Sec. 17, p. 225.  8.  (23) BURGESS, C.H. (1932). "The Kiln Shale Fauna." Bull. Mas. Camp. Zoo. Vol. T.XXTT, No. 5, p. 197* (24) EVANS, C.S. (1932). "Brisco-Dogtooth Map Area, British Columbia." Geol. Surv. Can. Summ. Rept. (1932), Pt. A,II, p. 142A. (25) WILLIAMS, M.T. aid BOCOCK, (1932). "Stratigraphy and Palaeontology of the Peace River Valley, British Columbia." " Trans.Roy. Soc. Can. Vol. XXVI, Sec. IV, p. 198. (26) WARREN, P.S. (1933). "Age of the Devonian Limestone at McMurry, Alberts." Can. Field Nat. Vol. XLVII, No. 8, p. LU8. (27) KELLY, Hi A. (1939) • . "Devonian and Mississippian Stratigraphy of Jasper Park, Alberta." Bull. Geol. Soc. Amer. Vol. 5"0, p. 2,000. (28) WARREN, P.S. (1942). "The Spirifer.argentarius fauna in the Canadian Rockies." Trans.Roy. Soc. Can. 3rd Series, Vol. XXXVI, Sec. 17, p.-129. (29) BEACH, H.H. (1943). "Moose Mountain and Mor ley Map Areas, Alberta. Geol. Surv. Can. Mem. 236.  n  (30) WARREN, P.S. (1944). "Index Brachiopods of the Mackenzie River Devonian." Trans. Roy. Soc. Can. Vol. XXXVIII, 3rd Ser., Sec. 17, p. 1944. (31) LANG, A.H. (19U7). "Brule and Entrance Map Areas, Alberta." Geol. Surv. Can. Mem. 244. (32) LAUDON, L.R. et al. (1949). "Stratigraphy of theWapiti Lake Area, B.C." Bull. Amer. Assoc. Pet. Geol. Vol. 33, Pt.II, p. 1518. (33) WARREN, P.S. (1949). "Fossil Zones.of the Devonian of Alberta". Bull. Amer. Assoc. Pet. Geol. Vol. 33, Pt. I, p. 564. (34) WARREN, P.S. and STELCK, C.R. (1949). "The Late Middle Devonian Unconformity in North West Canada." Trans. Roy.Soc. Can. Vol. XLIII, Ser. I l l , Sec. IV, p. 139« . (35) de WIT and McLAREN (1950) "Devonian Sections in the Rocky Mountains between Crownest Pass and Jasper, Alberta." Geol. Surv. Can. Paper 50-23*  9. (36) ERDMAN, O.A. (1950). "Alexo and Samders Nap Areas, Alberta.™ Geol. Surv, Can. Mem. 254• (37) WARREN, P.S. and STELCK, C.R. (1950). "Succession of Devonian Faunas. inWestern Canada. Trans. Roy.Soc. Can. Vol. XLIV, Ser.3, Sec. 4, p. 61. 0  (38) BELL, G.L. (1951). "Devonian Stratigraphy and Palaeontology of Ram River Area, Alberta." Unpublished Master of Arts Thesis, submitted to the University of British Columbia, April, 1951. (39) CRICKMAY, C.H. (1952). "Descriminatibn in the Later Upper Devonian." Jour. Pal. Vol. 26, No. 4, pp. 566-609. (40) CRICKMAY, C.H. (1952). "Some Devonian Spiriferidae from Alberta." Jour. Pal. Vol. 24, No. 2, pp. 214-225. (41) CRICKMAY, C.H. (1953). "Warranella A New Genus of Devonian Brachiopods." Jour. Pal. Vol. 27, No. 4, pp. 596-600.  10.  PART  II  IHTR0DUCTI0N This part of the thesis i s divided into four sections, the f i r s t three of which are introductory to the last section. Biological and palaeontological classifications are discussed f i r s t .  In  the second section a brief summary i s given of the classification of the Phylum Brachiopoda.  The third section i s a glossary of common terminol-  ogy used i n the description of brachiopod shells.  The fourth section  includes systematic description of brachiopod genera and species. These l i s t s were compiled from references on Devonian rocks of Western Canada which are included i n the bibliography to Part I of this thesis. The faunal l i s t s are supplemented by detailed descriptions of fifty-one genera and ninety-eight species  of brachiopods.  BIOLOGICAL AMD PALAEONTOLOGICAL CLASSIFICATIONS. In modern detailed studies of brachiopod f o s s i l s , attempts have been made to classify the fossils on the basis of phytogeny, rather than morphology. The theory of evolution i s the basis for phylogenetic classification. Phylogenetic classification i s an attempt to classify organisms according to their genetic a f f i n i t i e s . In the "ideal  0  case a genus would be a taxonomic unit.  The "genotype"  of the genus would represent the original stock from which a l l the species included i n the genus evolved.  This "ideal" classification of fossils i s  seldom possible because of the fragmentary nature of the f o s s i l record. Morphological classification was an older empirical approach to c l a s s i f ication.  A genus i n such a classification was a receptacle into which  morphologically similar species were placed regardless of their genetic  affinities.  ^  The modern trend i n brachiopod classification i s to s p l i t large compound genera into groups which are presumed to have genetic a f f i n i t i e s . Examples of studies i n which this has been done are those by Schuchert  and Cooper (1951), Cloud (19*5),  Williams (1955).  In order to attempt to trace the evolution of fossil species detailed, rather than general, descriptions of the type material are required. Both Thompson (1927) and Buckman (1918), have stressed this point. Thompson (1927) wrote:Biological classification i s now an attempt to express the degrees of a f f i n i t y through descent. Instead of as few characters as possible being used to decide upon the generic position of a species, as many characters as possible, as are necessary, are employed to determine the relationship to other species. It has frequently been found that the species grouped together under the older wide genera form homoeomorphous series of polyphyletic origin." 0  and Buckman (1918) stated t h a t i "It requires long and careful research to find the bases for proper definition (of the various homoeomorphous series) which i s not only much more satisfactory i n the end but gives a better idea of a f f i n i t i e s and a far truer picture of the methods of evolution." To sum up this discussion of classification, two principles may  be  stated:First, the description of type specific material should be as detailed as possible, i n order that genetic affinities between similar species could be studied. Second, species should be assigned to genera on a large number of characteristics. These two principles must be considered when the specific descriptions, which are assembled i n this thesis, are used for purposes of identification of unknown material. Detailed discussion of evolution and the phylogenetic approach  12.  to classictfation i a given i n Simpson (1955)* CLASSIFICATION OF THE PHYLUM BRACHIOPODA. Historical.  The classification of the Phylum Brachiopoda has been attempted by many authors since Fabius Columna f i r s t described brachiopod shells i n 1616.  Historical accounts of the development of brachiopod c l a s s i f i c -  ation are given i n Schuchert (1897) and Thompson (1927). Present day Brachiopod Classification. There exists today no completely satisfactory classification of the Phylum Brachiopoda. There i s general agreement that the phylum may be divided into two groups;  Class Articulata and Class Inarticulate.  The further division  of these classes i s s t i l l subject to discussion. Shrock and Twenhofel (1952) summed up the question of c l a s s i f i c ation as followsj"No existing classification of the Brachiopoda should be considered as f i n a l . Most specialists feel that much more needs to be known about living and f o s s i l brachiopods before a completely satisfactory c l a s s i f ication can be devised." Shrock and Twenhofel (1952) based their classification on the systems of classification suggested by three authors: Thompson (1927), Schuchert and La Vene (1929) and Cooper (1944). This classification i s adopted here. A l l descriptions of class, order and- superfamilies i n this thesis are taken from Shrock and Twenhofel (1952). TERMINOLOGY OF FOSSIL BRACHIOPODA. A glossary of brachiopod descriptive terms follows. The sources of these definitions are In works by Schuchert and Cooper (1951) and Moore, Lalliker, and Fisher (1952).  15.  GLOSSARY OP BRACHIOPOD DESCRIPTIVE TERMS.  ADDUCTOR MUSCLES Muscles which close the shell ADVENTITIOUS DEPOSIT Extra fibrous shell substance deposited by the mantle on the inside of the shell, f i l l i n g up cavities and irregularities of the surface. By deposition of such adventitious shell i n the umbonal cavities, the dental plates may be obliterated. ALA Lateral flange on outer side of crural lamellae. ANTERIOR That portion of the shell i n front of the hinge line away from beaks. APICAL PLATE A small f l a t structure situated in the apex of the delthyrium and flush with the interareas. To the under side of i t probably was attached the pedicle. This plate i s not a r e l i c t of the deltidium. APSACLINE See Interareas. AREA  See  Interareas.  ARTICULATION The locking together of the two valves, effected in the main by the teeth of the ventral valve moving in sockets of the dorsal valve, but maybe further assisted by the brachial parts. BRACHIAL VALVE See Dorsal Valve BRACHIDIA  Calcareous brachial supports in the spire- and loop-bearing pods.  brachio-  BRACHIOPHORES Plates that bound the notothyrial cavity (q.v.), also known as socket plates or brachial apparatus. BRACHIOPHORE SUPPORTS Plates attached to the dorsal face of the brachiophore, and used to strengthen the latter.  14.  CARDINAL ANGLE Angles formed at each of the extremities of the hinge between i t and the foreward extension of the shell. CARDINAL AREA See Interarea and Palintrope. CARDINAL EXTREMITY Lateral terminus of hinge line. CARDINAL PROCESS A median unpaired process, lying immediately on the inner side of the dorsal umbo, and serving for the attachment of the diductor muscles. CARDLNACIA Process near the posterior or cardinal margin in the interior of the dorsal valve, connected with articulation, muscle attachment, and attachment of brachial supports. CATACLINE See Interareas. CHLLLDIAL PLATES Discrete plates, one on either side of the notothyrium, and partially closing i t . CHILIDIUM The covering of the notothyrium, the dorsal equivalent of the ventral deltidium. COMMISSURE The boundary line between the anterior and lateral margin of the valves. See Plane of Commissure and R ctimarginate. e  CONVEXITY In describing the convexity of a brachiopod, the dorsal valve i s named f i r s t ; this i s for the sake of making comparisons always in the same direction, namely, from dorsal above to ventral below. See Resupinate. COSTA (COSTAE) A coarse r i b on the outer surface of a valve. Costae may be angular sub-angular or rounded. COSTELLA (COSTELLAE) Fine external ribs which may be angular, sub-angular or rounded. CRURA (sing. CRUS) Processes i n the dorsal valve of the Telotremata to which are attached the fleshy brachia or the brachidia.  15.  CRURAL BASE Projection from hinge plate of brachial valve at edge of notothyrium for attachment of one of crura. CRURAL PLATE A general term commonly applied t o the brachial processes of the orthids, strophomenids, and rhynchonellids, without regard to detailed structure, function, or homologies. CRURAL IUM The dorsal equivalent of the ventral spondylium. DELTARIUM See D e l t i d i a l Plates DELTHTRIAL CAVITY Ventral umbonal cavity bounded by dental plates. DELTHYRIUM The triangular aperture which transects the ventral interarea medially, and through some portion of which the pedicle passes. The delthyrium may or may not be closed by a deltidium or d e l t i d i a l plates. Its equivalent i n the dorsal valve i s the notothyrium (q.v). DELTIDIAL PLATES In Telotremata, two plates growing medially from the walls of the delthyrium after neanic growth. These often unite medially, closing the delthyrium more or less completely. When united they make a Deltarium = symphytium of Buckman, pseudodeltidium of Schuchert. In Protremata, similar plates are at times developed and these are called Lateral Plates (q.v.). DELTIDIUM  An independent, more or less strongly arched plate i n the ventral pal in trope or cardinal area i n many Protremata, growing from the apex toward the hinge-line and partly or completely covering the delthyrium. I t i s always delimited from the inter area by grooves. It i s characteristic of primitive shells, and i s formed by a f l a p of the ventral mantle.  DENTAL PLATES or DENTAL LAMELLAE V e r t i c a l or nearly v e r t i c a l plates associated with the teeth of the ventral valve, usually uniting the palintrope t o the floor of the valve, and bounding the delthyrial cavity. They are separated from the walls of the shell by the umbonal cavities. When the l a t t e r have been f i l l e d by adventitious s h e l l , the dental plates become OBSOLETE. DENTAL SOCKETS Excavations i n the dorsal cardinal margin i n which the teeth of the ventral valve articulate.  DENTICLES Small processes on the posterior surface of the dorsal socket which are inserted into the accessory sockets i n the v e n t r a l teeth. DIDUCTOR MUSCLES Muscles that open the valves. DORSAL DIRECTION Toward the dorsal valve at r i g h t angles to the plane of commissure. DORSAL MEDIAN RIDGE A low a x i a l thickening on the d o r s a l i n t e r i o r of most orthids and rynchonellids. See Median Septum. DORSAL VALVE Usually the smaller valve and the one to which the brachia are always attached. Synonyms: BrachialValve Socket Valve Entering Valve Haemal Valve DUPLEX SPONDYLIUM See Spondylium Simplex. ENDOPUNCTAE See Punctae EXOPUNCTAE See Punctae FHAE Fine elevated concentric l i n e s . FOLD A broad median external undulation or p l i c a that may be situated on either the d o r s a l or the v e n t r a l valve, hence d o r s a l or v e n t r a l f o l d . More common fcn the dorsal v a l v e . I t s counterpart i s the SULCUS. FORAMEN See Pedicle Foramen FOSSETTE SeeCrural  Fossette  FULCRAL PLATES Small concave plates attached to the outside wall of the brachiophore support or brachiophore and inner wall of the s h e l l . They serve to define the sockets and strengthen the brachiophore supports. GERONIC Signifying e l d age.  17. GROWTH LINE M a r k i n g on s h e l l s u r f a c e p a r a l l e l t o v a l v e m a r g i n , i n d i c a t i n g p o s i t i o n of t h i s margin.  former  HINGE LINE L i n e along which a r t i c u l a t i o n takes p l a c e . HINGE PLATE D i v i d e d o r u n d i v i d e d p l a t f o r m i n beak r e g i o n o f b r a c h i a l i n t e r i o r , g e n e r a l l y j o i n e d t o d e n t a l s o c k e t s and c r u r a l b a s e s ; may be d i v i d e d i n t o i n n e r and o u t e r p l a t e s . HINGE TOOTH P r o j e c t i o n on h i n g e l i n e o f p e d i c l e v a l v e w h i c h f i t s d e n t a l s o c k e t of b r a c h i a l v a l v e , s e r v i n g as p i v o t i n a r t i c u l a t i o n . INNER HINGE PLATE S u b h o r i z o n t a l s m a l l p l a t e e x t e n d i n g m e d i a l l y from c r u r a l b a s e . INTERAREA P o s t e r i o r p l a n e o r c u r v e d s u r f a c e l y i n g between t h e apex and t h e l i n e o of valve j u n c t i o n . Synonym: C a r d i n a l A r e a . J.UGUM S i m p l e o r complex c o n n e c t i o n between h a v l e s o f a b r a c h i d i u m . LATERAL AREAS The p a r t s o f the v a l v e s on e i t h e r s i d e o f t h e median a x i s o r on e i t h e r s i d e o f the f o l d and s u l c u s . LATERAL PLATES E x t e r n a l m a r g i n a l p l a t e s r e s t r i c t i n g t h e d e l t h y r i u m and seen o n l y i n c e r t a i n o r t h i d s and p e n t a m e r i d s . These d i s c r e t e p l a t e s appear t o be formed i n e x a c t l y the same manner as d e l t i d i a l p l a t e s . LATERAL SEPTA" See Median Septum. MEDIAN RIDGE See d o r s a l median r i d g e and median s e p t u m . MEDIAN SEPTUM A l o n g i t u d i n a l v e r t i c a l p l a t e between t h e v e n t r a l m u s c l e s . LATERAL SEPTA a r e r a r e l y d e v e l o p e d between t h e muscles o f t h e same v a l v e , b u t are moreoften p r e s e n t when s p o n d y l i a are d e v e l o p e d . MULTICOSTATE See C o s t a e . MUSCLE IMPRESSIONS Marks o f muscle attachment on the  shell.  18 MUSCLE SCAR A more o r l e s s w e l l d e f i n e d a r e a r e p r e s e n t i n g muscle a t t a c h m e n t . MYOPHORE The rugose s u r f a c e See S h a f t .  the f i n a l or  o f t h e muscle attachment on the c a r d i n a l  last  process.  NEANIC S i g n i f y i n g y o u t h , or the stage i n w h i c h s p e c i f i c c h a r a c t e r s b e i n g to develop. NEPIONIC D e s i g n a t i n g the smooth s h e l l s t a g e s u c c e e d i n g t h e  protegulum.  NOTOTHYRIAL PLATFORM T h i c k e n e d s h e l l m a t t e r i n t h e umbonal i n t e r i o r o f t h e d o r s a l v a l v e between t h e b r a c h i o p h o r e p l a t e s . I t i s t h e s e a t o f d i d u c t o r muscle attachment i n p r i m i t i v e b r a c h i o p o d s n o t y e t p o s s e s s i n g a c a r d i n a l processj i n o t h e r s h e l l s i t i s t h e p l a c e where t h e v e n t r a l c a r d i n a l process a r i s e s . NOTOTHYRIUM and NOTOTHYRIAL CAVITY The d o r s a l c o u n t e r p a r t o f t h e v e n t r a l d e l t h y r i u m and d e l t h y r i a l cavity. OUTER HINGE PLATE P a r t o f hinge p l a t e e x t e n d i n g l a t e r a l l y outward from c r u r a l b a s e . PALIN TROPE The a n t e r o - v e n t r a H y or a n t e r o - d o r s a l l y d i r e c t e d s h e l f d e v e l o p e d a t t h e p o s t e r i o r end o f t h e d o r s a l and v e n t r a l v a l v e s due t o t h e p r o g r e s s i v e m i g r a t i o n of the hinge margin i n i t s growth, formerly c a l l e d c a r d i n a l area. PALLXAL MARKING Sinuous b r a n c h i n g i m p r e s s i o n on p a r t s o f s h e l l i n t e r i o r o u t s i d e muscle s c a r s , formed b y f l u i d - f i l l e d passageways o f mantle ( p a l l i a l s i n u s e s ) , w h i c h connect w i t h body c a v i t y i n the p o s t e r i o r p a r t o f shell. PEDICLE CALLIST A c a l l u s o f s h e l l substance a t t h e i n t e r n a l apex o f t h e v e n t r a l v a l v e between the d e n t a l l a m e l l a e , t o w h i c h t h e p o s t e r o - v e n t r a l s u r f a c e o f t h e p e d i c l e was a t t a c h e d . PEDICLE FORAMEN A s m a l l or l a r g e r o u n d p e r f o r a t i o n a t t h e apex o f e l s e w h e r e - t h r o u g h t h e d e l t i d i u m f o r t h e p r o t r u s i o n o f a s m a l l p e d i c l e ; w i t h age, i t may become l a r g e b y a b r a s i o n . When t h i s foramen i s a b s e n t , the p e d i c l e emerges between t h e d e l t i d i u m and c h i l i d d u m , o r t h e s e c o v e r i n g s may c o m p l e t e l y c l o s e t h e d e l t h y r i u m and n o t o t h y r i u m , i n w h i c h c a s e t h e r e i s no known f u n c t i o n a l p e d i c l e .  19. PEDICLE MUSCLES M u s c l e s w h i c h r e t r a c t the p e d i c l e . PEDICLE VALVE One o f the two main p a r t s o f b r a c h i o p o d s h e l l w h i c h bear s a t t a c h m e n t o f p e d i c l e j b y c o n v e n t i o n , d e f i n e d as v e n t r a l i n p o s i t i o n . PLANE OF'COMMISSURE The plane p a s s i n g t h r o u g h the a n t e r i o r commissure and t h e  hinge-line.  PLICA See f o l d . PLICATE Used o f a s h e l l t h a t has u n d u l a t i o n s a f f e c t i n g b o t h the i n t e r i o r and outer surfaces. The p r i m a r y o r n a m e n t a t i o n i s superposed over t h e plications. POSTERIOR REGION That r e g i o n o f the s h e l l back o f the t r a n s v e r s e a x i s and t o w a r d beak, or apex.  the  PROTEOULUM The i n i t i a l s h e l l o f a l l b r a c h i o p o d s . PSUDOCURALIUM See N o t o t h y r i a l P l a t f o r m . PSEUDORESUPINATE See R e s u p i n a t e . PSEUDOSPONDYLIUM A c a l l u s r e s e m b l i n g a s p o n d y l i u m , d e v e l o p e d i n some s h e l l s b e n e a t h t h e m u s c l e s o f the v e n t r a l v a l v e and c o n f l u e n t w i t h the i n n e r l o w e r surfaces of the dental l a m e l l a e . PUNCTAE Any minute p e r f o r a t i o n s o f t h e t e s t . Types o f Punctate t e s t s : P u n c t a t e - The i n n e r f i b r o u s l a y e r i s p e r f o r a t e d b y s m a l l h o l e s r e p r e s e n t i n g c a v i t i e s o c c u p i e d b y minute c a e c a o f t h e mantle.. Impunctate - Have t h e f i b r o u s l a y e r dense and i m p e r f o r a t e . Pseudopunctate - The f i b r o u s l a y e r s u r r o u n d s and o f t e n c o v e r s i n t e r n a l calcareous s p i c u l e s . I n worn o r e x f o l a t e d specimens s h e l l l a y e r s t e a r away from the s p i c u l e s and l e a v e coarse p i t s that simulatepunctae. RECTIMARGrlNATE Having a s t r a i g h t  anterior  commissure.  RESUPINATE A c o n d i t i o n w h e r e i n t h e r e l a t i v e c o n v e x i t y o f the two v a l v e s i s r e v e r s e d , t h e convex v e n t r a l v a l v e o f t h e e a r l y growth s t a g e s becoming concave and the concave d o r s a l v a l v e becoming s t r o n g l y convex, p r o d u c i n g t h e r e b y a convexo-concave s h e l l .  20. ROSTRATE.. Having a l o n g beak produced b y n a r r o w i n g o f t h e h i n g e l i n e .  RUGA Concentric s h e l l corrugation which affects surfaces.  both outer  and i n n e r  SEPTUM * See D o r s a l Median R i d g e and M e d i a n Septum. SESSILE CRURALIUM SeeCruralium SESSILE SPONDYLIUM A. s p o n d y l i u m w h i c h r e s t s d i r e c t l y on t h e f l o o r o f t h e v a l v e w i t h o u t t h e s u p p o r t o f a median r i d g e . SHAFT The s h a f t o r s t a l k o f t h e c a r d i n a l p r o c e s s , w h i c h b e a r s the myophore o r s e a t o f d i d u c t o r muscle a t t a c h m e n t .  SINUS See S u l c u s SOCKETS S o c k e t s are found i n b o t h v a l v e s and a r e used i n t h e a r t i c u l a t i o n process. SPINE Long or s h o r t , s t r a i g h t o r c u r v e d , s o l i d o r h o l l o w p r o j e c t i o n o f the s h e l l surface.  SPIRALIUM One o f t h e p a i r o f s p i r a l b r a c h i d i a on i n t e r i o r o f some b r a c h i a l valves. SPONDYLIUM A spoon shaped p l a t e t e r m i n a t i n g more o r l e s s f r e e l y , l o c a t e d i n t h e apex o f t h e v e n t r a l v a l v e o f v a r i o u s s t o c k s o f a r t i c u l a t e b r a c h i o p o d s . T h i s p l a t e s e r v e s as the s e a t o f attachment o f t h e m u s c l e s . It is s u p p o r t e d b y a more o r l e s s e l e v a t e d , l o n g o r s h o r t , median septum. K o z l o w s k i has r e c e n t l y shown (1929) t h a t t h e s p o n d y l i u m may be d i v i d e d i n t o three d i f f e r e n t types. SPONDYLIUM DISCRETUM D e n t a l p l a t e s do n o t converge and u n i t e media i l l y , b u t e x t e n d d i r e c t l y to the f l o o r of the v a l v e . S t r i c t l y spadeing t h i s i s not a spondylium, b u t s u c h a c o n d i t i o n o f the d e n t a l p l a t e s i s p r i m i t i v e and d e s e r v e s a designation. SPONDYLIUM DUPLEX See Spondylium S i m p l e x .  21. SPONDYLIUM SIMPLEX A t e r m a p p l i e d b y K o z l o w s k i t o the t y p e o f s p o n d y l i u m i n w h i c h the d e n t a l p l a t e s and the v e r t i c a l septum are u n i t e d i n t o a s i n g l e p i e c e . T h i s t y p e i s i n c o n t r a s t t o the Spondylium D u p l e x o f Pentamer us w h i c h i s composed o f two p i e c e s each o f w h i c h i s borne on a b a s a l septum. SPONDYLOID I n t h i s c o n d i t i o n the d e n t a l p l a t e s a r e so t h i c k e n e d on t h e i r i n n e r b a s a l s i d e s t h a t t h e added t e s t a c e o u s d e p o s i t grows t o g e t h e r and s i m u l a t e s a s p o n d y l i u m . T h i s c o n t r a s t s w i t h the p s e u d o s p o n d y l i u m , w h i c h i s formed b y a c a l l o u s t h i c k e n i n g on the f l o o r o f the v a l v e . STRIAE I n t e r s p a c e s between c o s t a e and c o s t e l l a e . T h i s term has been much abused and i t s c u r r e n t use f o r a r a d i a l r i b i s i n c o r r e c t . SULCUS (SULCATE) A median d e p r e s s i o n i n t h e c o n v e x i t y o f t h e s h e l l , t h e o p p o s i t e o f a f o l d or p l i c a . R e p l a c e s t h e t e r m s i n u s . TEETH The two a r t i c u l a t i n g p r o c e s s e s o f t h e v e n t r a l v a l v e . There a r e a l s o a c c e s s o r y small t e e t h i n the d o r s a l v a l v e i n many b r a c h i o p o i d s , w h i c h are h e r e c a l l e d D e n t i c l e s . THICKNESS L i n e a r d i s t a n c e from f a r t h e s t  o p p o s i t e p o i n t s on s u r f a c e o f the two v a l v e s .  TRAIL. A n t e r i o r p r o l o n g a t i o n o f some b r a c h i o p o d s h e l l s , g e n e r a l l y a s t r o n g angle t o g e n e r a l plane o f p o s t e r i o r p o r t i o n of v a l v e s . TRANSVERSE AXIS A l i n e t h r o u g h t h e w i d e s t p a r t o f t h e s h e l l from l e f t t o r i g h t . UMBO Convex p o r t i o n o f v a l v e a d j a c e n t  t o beak  UMBONAL CAVITIES Chambers s e p a r a t i n g the d e n t a l l a m e l l a e from t h e w a l l s o f the v a l v e . UNIPLICATE A term a p p l i e d t o t h e a n t e r i o r commissure when t h e r e i s a f o l d i n t h e d o r s a l v a l v e opposed b y a s u l c u s i n t h e v e n t r a l v a l v e . UNISULCATE i s the r e v e r s e c o n d i t i o n . VENTRAL A c c o r d i n g t o c o n v e n t i o n , d i r e c t i o n away from p o s i t i o n o f b r a c h i a l v a l v e toward o p p o s i t e v a l v e ; v e n t r a l v a l v e i s t h u s e q u i v a l e n t t o pedicle valve.  22. VENTRAL DENTAL SOCKETS Small sockets i n the t e e t h of the v e n t r a l v a l v e next t o the hinge margin. I n t o t h e s e a r t i c u l a t e s m a l l d e n t i c l e s on t h e o u t e r w a l l of t h e d e n t a l s o c k e t . They are a l s o c a l l e d ACCESSORY DENTAL SOCKETS. VENTRAL VALVE The s h e l l s i t u a t e d on t h e v e n t r a l s i d e o f t h e a n i m a l and i n a r t i c u l a t e forms h a v i n g the t e e t h on each s i d e o f t h e d e l t h y r i u m . U s u a l l y .the l a r g e r and deeper o f .the two v a l v e s . Synonyms: P e d i c l e Dental Receiving Neutral WIDTH L i n e a r d i s t a n c e between f a r t h e s t o f a v a l v e or s h e l l .  o p p o s i t e p o i n t s on l a t e r a l m a r g i n s  25. THE LAYOUT OF THE SYSTEMATIC LISTS AND DESCRIPTIONS. Descriptions of Classes. Orders and Superfamillee. These are a l l taken from Shrock and Twenhofel (1952).  The  stratigraphic ranges of the various genera, where given, are taken from Shimer and Shrock (1944). Systematic Lists of Genera and Species. The generic and specific names i n these l i s t s are usually followed by a number (or numbers).  The numbers refer to papers cited i n the  bibliography i n Part I of this thesis.  A few brachiopod species listed  here were described by Thomlinson*, and do not appear i n the references which were used for compiling the faunal l i s t s . An asterisk beside a specific name indicates that species i s illustrated and described after the generic description of the genus to which i t belongs. Layout of Generic Descriptions. Each generic description commences on a new page. A generic description i s headed by the name of the genus, under which i s the name of the original author ( i f known), and the date that the genus was f i r s t described.  Below the heading the reference from  which the description following was taken, i s l i s t e d .  The description  i s usually followed by the name of the species on which the genus was based and the stratigraphic range of the genus, i f i t i s known. Layout of the Specific Descriptions. Eaeh specific description i s laid out i n a similar fashion to the generic descriptions, except that a line drawing of each species i s included, with the text. •Thomlinson and Geology 521 class 1952*55* (See Acknowledgments  24.  Illustrations of the Genera. Seven plates follow the brachiopod descriptions.  On each plate  line drawings of a typical species i n each genus i s illustrated. brachiopod illustrations are grouped together i n superfamilies.  The  PHYLUM BRACHIOPODA  Range  Class Inarticulata Order Atremata Superfamily Lingulacea  Lower Cambrian to Recent  Order Neotremata Sjqperfamily Craniaea Class Articulata Superfamily Dalmanellacea  Middle Ordovician to Permian  Superfamily Pentameracea  Middle Ordovician to Devonian  Superfamily Strophomenacea Lower Ordovician to Recent Superfamily Chonetacea  Ordovician to Permian  Superfamily Productacea  Lower Devonian to Permian  Superfamily Rhynchonellacea Middle Ordovician to Recent Superfamily Atrypacea  Middle Ordovician to Upper  Superfamily Splriferacea  Ordovician to Triassic  Superfamily Terebratellacea Lower Silurian to Recent  26. PHYLUM BRACHIOPODA Class Inarticulate. "Inarticulate brachiopods have shells composed of conical or tongue-shaped valves that lack articulation and are held in apposition bymuscles alone. The shell matter i s chitinophosphatic or calcareous, and growth of the shell i s either holoperipheral or mlxoperipheral. In the embryo the mantle lobes develop directly without revolution, and the pedicle develops during the free-swimming stage within the valves of the protegulum from the ventral mantle lobe. At a later stage the pedicle, which clearly is attached to the larger (pedicle) valve, i s protruded and used for fixation. Most inarticulate shells are circular or oval in outline and asymmetrically conical in profile, but some have a tongue-shaped outline and a f l a t lenticular profile. The conical forms, excepting the cemented Craniidae, are fixed by a short pedicle, whereas the lingulids have a long flexible pedicle and live in burrows with their setiferous anterior margin protruding. The development and migration of the pedicle are complex. The complicated muscle system leaves an equally complicated set of muscle marks." Range: Lower Cambrian to Recent. Order Atremata "The Atremata are inarticulate, chitinophosphatic-shelled brachiopods of subtriangular, oval to subrounded, or tonguelike outline having the pedicle attached to the larger (or pedicle) valve, in which i t occupies a groove. Specialized forms have heavy calcareous shells with internal platforms for muscle attachment. Superfamily Lingulacea. (Shrock and Twenhofel). "Elongate chitinophosphatic and thin-shelled atremates probably derived from the Obolacea, as the pedicle structures are similar. They have highly differentiated muscles and a wormlike tubular and flexible pedicle, both of which aid the animal in i t s free-living and burrowing habit. Modern Lingula a typical genus of the superfamily, has a long and ancient history. It appeared f i r s t i n the Ordovician, as one of the earliest representatives of the superfamily, and has persisted to the present with l i t t l e evident change. Range:  Lower Cambrian to Recent. *L.  Genus Lingula Linn.  35", 36.  Minuta  Meek  L. Mel ie Hall. 23. L. Spat ul at a Vanuxem. 3k, 37.  27. Genus LINGULA Bruguiere n. gen. (1797) Meek ( i ? 7 i ) Smith Contrib. t o Knowl. 172, Pt. 1. p. 68 "Shell oblong or more or l e s s oval, depressed, t h i n , gaping at each end, and rounded or subtruncste i n f r o n t , and more or l e s s pointed at the beak, consisting of alternate corneous and testaceous laminae, the former of which are fibrous and the l a t t e r tubular; composition l a r g e l y phosphatic. Valves both moderately convex, held together by the action of muscles; beak of v e n t r a l valve more pointed and prominent than that of the other. Surface smooth or marked by concentric l i n e s , sometimes crossed by r a d i a t i n g s t r i a e . Pedicle long thick c y l i n d r i c a l f l e s h y and f l e x i b l e . "  Genotype:  Lingula Anatina.  KINUTA  DEVONIAN HRACHIOPODA  ~ l\ ^"•l  Thia la the smallest specimen of Unguis I have avar Man, and may possibly ba a young shell. It resembles closely Llnguls apftula Hall, from tha enesse al»ta or Haw Tork, bjt la r»thar wider in proportion to length, and ii-• • a n.ora pointed bask. It la alao mora convex than any specimens I h»ve ss.i. of that apeclea. Locality! Near Fort Ra.elution, cn jreat Slava Lake. ijietframi Ventre view.  LjmULA J—J Meek (1868) Trans. Chic. Acad. Sci. Vol. 1, p. 87. LPPutA MDTOTA Meek Dssorlptloni Shall minute, extremely thin, ovate, rather convex) front r-ther narrowly rounded) sides most convad In outline alightly In front of the middle, thence narrowing with alight convexity to tha beak, whloh is obtusely pointed. Surface polished, but showing, under a strong mngnetfler, microecoplc lines of growth. Langth, U.06 inch, breadth, 0.0$ Inch.  IBCULA  CLASS EJARTICULATA Order Neotremata. "The Neotremata are a specialised and, to a certain extent, degenerate brachiopod, having small chitinous, chitinophosphatic (or, rarely, supposedly calcareophosphatic) or calcareous shells consisting typically of high or flattened conical valves. The pedicle when present, emerges through a perforation or sheath, or a triangular c l e f t , and i n maturity i n certain forms may be lost when the pedicle valve i s cemented to the substratum. The protegulum i s semicircular or semieliptical and the adult shells are circular or e l l i p t i c a l , because shell growth i s holoperipheral. Range: Lower Cambrian to Recent." Superfamily Craniaea. (Shrock and Twenhofel.) Neotremates with flattened calcareous shells lacking a pedicle opening and usually cemented to some object by pedicle valve. Range: Ordovician to Recent. Genus Crania  Retzius  C. hamiltonae  19 Hall  2, 27.  29. Genus CRANIA: Retzius n. gen. Retzius (1781) Schrifte der Berliner Gesellschaft Nat. Freunde, Vol. 2. p. 72. Description from Nettleroth (1889) Kentucky Fossil Shells, p. 31. "Shell smooth or striated by radiating striaej umbo of the dorsal valve sub centralj umbo of the ventral valve sub-central, marginal or prominent and cap l i k e with an obscure triangular area transversed by a central line. Shell usually attached to other shells or marine bodies. The large muscular impressions of the attached valve are sometimes convex in other species, deeply excavatedj those of the upper valve are usually convex. In C. tripartita of Munster, the nasel process divides the fixed valve into three eells. Some of the species are entirely free or but slightly attached." Genotype:  Anomia Craniolaris (Linne) Crania Baattensburgensis (Retzius).  Description from Thomson (1927), Brachiopod Morphology and Genera (Recent and Tertiary), New Zealand Board of Sci. and Art Manual. "Shell inequivalue, ventral valve cemented to i t s support by almost i t s whole surface, dorsal valve more or less conical, apex sub central, directed posteriorly, outline subcircular to sub rectangular, posterior margin straight or slightly indented; test smooth or with radiating striae, ribs or spinules calcarious, penetrated by vertical canals which repeatedly branch toward the outer surface. Interior with muscular impressions generally strongly marked, especially the posterior adductors, which l i e near the posterior margin some distance apart and the anterior adductors, which are only a l i t t l e behind the centre of the valves and are close together. In front of the muscular impressions the interiors of the valves show 4-7 grooves on either side, being the impressions of the p a l l i a l sinuses. Mantle without marginal setae, branchia Spirolophus with the apices of the spires directed dorsally. Five to eight coils."  50.  PHYLUM BRACHIOPODA Class Articulata. "Articulate brachiopods have oval and transverse calcareous shells composed of two typically convex but unequal-sized valves that are held together along the posterior hinge line by means of articulating devices. The shell i s opened and closed by the action of specialized muscles, and the valves, like the leaves of a book, have only one motion, that of simple opening and closing on a single axis. Each valve has a triangular opening in the pal in trope. The opening on the pedicle pal in trope i s the delthyrium, whereas that on the brachial i s the notothyrium; both tend to be modified* The shell can be adjusted on the pedicle, and most articulates have the pedicle opening more or less modified. The shellmatter i s dominantly calcium carbonate with fibrous prismatic structure, and growth i s largely hemiperipheral. In the development of the embryo the mantle lobes are revolved or reversed from a posterior to an anterior position. The pedicle i s developed from the caudal part of the embryo and i s never enclosed within the shell as in the Inarticulata. It i s attached by muscles to both valves, but i t belongs to the larger or pedicle valve. In no known articulate brachiopod does the pedicle l i e in the brachial valve. Although the intestine lacks an anus in a l l living representatives, i t may have had an anal opening i n some ancient and extinct genera. Most articulates show modifications of the delthyria and notothyria and development of many kinds of calcareous supports for the brachia. They also exhibit much variation in surface sculpture." Range: Lower Cambrian (Palaeotremata) to Recent. Superfamilies of the Phylum Brachiopoda here desribed from Shrock and Twenhofel (1962). Superfamily Dalmanellacea Superfamily Pentameracea Superfamily Strophomenacea Superfamily Chonetacea Superfamily Produetacea Superfamily Rhynchonellacea Superfamily Atrypacea Superfamily Spiriferacea Superfamily Terebrafeiiaeea  Superfamily Dalmanellacea (Shrock and Twenhofel, .p. 3 2 5 ) . "Dalmanellids are endopunctuate crthoids with a lobed (usually trilobed) cardinal process. The superfamily i s thought to have been derived from the Orthacea. Representatives appeared f i r s t i n the Middle Ordovicianj they spread widely and diversified greatly during the Silurian and Devonian; and the superfamily f i n a l l y became extinct during the Permian." Ranget  Middle Ordovician to Permian.  Genera Described:  Range:  I . Genus Aulacella Schuchert and Cooper I I . Genus Cariniferella Schuchert and Cooper I I I . Genus Phipidomella Oehlert  Upper Devonian Silurian to Permian  17. Genus Schizophoria King.  Silurian to Pennsylvanian  Reported occurrences of this superfamily i n the literature reviewed i n Part I of this thesis. I . Genus Aulacella Schuchert and Cooper A. infra• 3 8 . I I . Genus Cariniferella Schuchert and Cooper C. iowensis Stainbrook. 3 7 . I I I . Genus IBhipidomella Oehlert. 3 6 . 1 0 , 2 1 , 21*, 3 5 , 3 7 .  17. Genus Schizophoria King.  * S. allani Warren. 30. S. athabaskensis Warren. * 5. iowensis Hall.  30, 3 8 .  9, 30,36, 37.  * S. lata Stainbrook. 3 0 . S . macfarlani Meek. S. striatula Schlotheim.  1 3 , 1 5 , 21*, 31*, 3 7 . 8 , 1 0 , 1 2 ,1 3 ,1 6 ,18, 1 9 , 2 0 , 21,  22,  21*,  26,  33,  31*,  36,  37.  52. Genus AULACELLA Schuchert and Cooper n. gen. Schuchert and Cooper, Amer. Jour. Sci. (5"), v o l . 22, 1931,  p.246.  "This genus externally resembles Rhipidomella and Thiemella but has a well marked fold on the ventral valve and a sulcus on the dorsal which are not reversed in the young stages. Internally the arrangement of the ventral muscle-scars i s similar to that of Rhipidomella in the imprisonment of the adductor, f i e l d by the diductor scars. The diductor impressions are never broadly flabellate as in Rhipidomella and the adjuster marks are usually clearly visible as in Cariniferella. Furthermore, the diductor impressions are separated by a low ridge which i s forked much as in Cariniferella« This i s a feature never shown by Thiemella or Rhipidomella in which th"e median ridge i s always direct and unforked. In the dorsal valve the cardinalia are ponderous and strongly resemble those of Cariniferella and Rhipidomella but are totally unlike those of Thiemella which are delicate and confined. In our classification Aulacella i s placed in association withDalmanella and Cariniferella because of the close similarity of the ventral musculature and dorsal cardinalia. The only known species i s the German Orthis eifelensis." Genotype: Range:  Orthis eifelensis de VerneuU.  55. Genus CARINIFERELLA Schuchert and Cooper n. genus. Schuchert and Cooper, Amer. Jour. Sci. (5), vol. 22, 1931, p. 21*6. "Transversely semicricular, margins rounded, cardinal angles obtusely rounded; hinge-line narrower than the greatest width of the shell; lateral profile convexo-concave to unequally biconvex; anterior commissure sulcate; fold narrow, subcarinate; sulcus deep, narrow}, ventral interarea short, "apsacline, beak not prominent, incurved, umbo low, convex and sulcate. Ornamentation multicostellate, with elevated growth-lines covering the whole surface. Test fibrous, punctate. Ventral interior: Delthyrial cavity deep; teeth strong; dental plates thick, nearly obsolete in adults; muscle f i e l d bilobed in front; diductor scars elongate, expanded anteriorly; adductor track linear, not enclosed in front by the diductor scars. Aggregate adductor scar e l l i p t i c a l . Adjuster scars narrow, divergent, short, placed posterior to the diductor impressions. Short p a l l i a l sinuses extending antero-laterally for a short distance in frong of the diductor scars. Dorsal interior: Cardinalia confined to the immediate v i c i n i t y of the hinge, sockets deep, oblique; brachiophore plates widely divergent and extending vertically to the floor of the valve, without fulcral plates; cardinal process very small, shaft short, myophore trilobed; median ridge low, extending to the anterior margin of the muscle area where i t merges into the fold produced by the ventral sulcus. Muscle area small as a whole, not extending to the middle of the shell. Adductor scars separated by horizontal ridges; anterior adductors the smaller. Genoholotype:  Qrthis carinata Hall  Range: Upper Devonian. Distinguishing Characters: The distinctive features of this genus are the convexo-concave profile of the shell, the aberrant sharp fold gnd the.corresponding deep, narrow sulcus, the Dalmanella-like ventral musculature, the strongly divergent brachiophore plates, and the small muscle area of the dorsal valve."  5* Genus RHIPIDOMELLA Oehlert n. gen. Oehlert, Jour. Conch. (3), vol. 30(38), 1890, p. 372. Horn. RhipidomyB Oehlert I887. "Exterior: Sub-trigonal to circular, anterior margin not uncommonly emarginate, hingeline narrow; lateral profile unequally biconvex, the brachial valve having the greater convexity, with the ventral one concave at the front in many species; anterior commissure faintly uniplicate or rectimarginate; in some instances a sulcus on each valve; ventral interarea the longer, curved, apsacline, umbo swollen or gently convex, beak incurved; dorsal interarea greatly reduced, ortho- to apsacline; delthyrium open notothyrium usually closed by the cardinal process or partially by c h i l i d i a l plates; surface multicostellate, hollow costellae numerous. Fibrous, punctate. Ventral interior: Delthyrial cavity shallow; dental plates abbreviated, teeth strong, divergent, elongate; a broadly curved ridge extending from the bases of the low dental plates around the margin of the muscle field; muscle f i e l d large, flabellate, not confined to the delthyrial cavity, occupying from one-third to five-sixths the length of the valve and usually deeply impressed; diductor scars semiflabbelate, separated from each other by a sharp or low broad ridge, completely enclosing the adductor scars, which form an e l l i p t i c a l patch just anterior to the pedicle c a l l i s t ; adjuster scar commonly discernible on the outside of the diductor scar; pedicle c a l l i s t occupying the delthyrial cavity. Dorsal interior: Cardinalia confined, sockets wide, deep, without concave fulcral plates; brachiophores long, bluntly pointed, supported by adventitious substance deposited beneath their anterior edge; sharp processes or points on the ends of the brachiophores have been interpreted as crura; cardinal process large, myophore commonly ponderous, lobate; shaft short. Median ridge extending to the middle of the shell. Muscle f i e l d quadripartite, the posterior scars the larger. Ovarian and p a l l i a l impressions occupying the area of the shell not covered by the muscle marks. Genotype: Terebratula michelini L'Eveille. Range:  Silurian (Clinton) to close of Permian.  Distinguishing Characters: Rhipidomella i s characterized externally by i t s nearly circular, or, in later species, subtrigonal outline; the unequal convexity of the valves, of which the dorsal i s almost always the more ventricose, and the ventral one usually either markedly concave or showing a tendency in that direction. The hinge-line i s always very narrow. Internally the ventral musculature i s very characteristic and the teeth are different from those in nearly a l l other genera of the orthids. The dorsal valve with i t s arched umbo, has a ponderous cardinal  55 process with a very short shaft but an expanded myophore* The cardinalia are distinctive and consist of widely divergent brachiophores supported by inconspicuous depesits of adventitious shell much as i n Heterorthis.  56*. Genus SCHIZOPHQRIA King new gen* King, Mon. Perm. Foss., 1850, pp. 105, 106. "Exterior: Externally l i k e Hebertella; margins rounded, carindal extremities rounded, hinge-line usually narrower than the greatest width of the shell, lateral profile resupinate, convexity of valves varying, the dorsal valve always with the greater convexity, anterior commissure rectimarginate to uniplicatej dorsal valve frequently with a low fold; ventral valve frequently sulcate i n front; ventral palintrope the longer, faintly or strongly apsacline, curved or plane, beak slightly or strongly incurved, umbo gently or strongly convex; dorsal palintrope short, curved very strongly apsacline so that i t overhangs the ventral interarea; multicostellate, with abundant hollow costellae; test fibrous, punctate. Ventral interior: Delthyrial cavity usually deep, teeth strong; crural fossettes oblique; dental plates strong, frequently obscured by adventitious deposit, extended about the margins of the muscle area as a low ridge; muscle area bilobate or obcordate; diductor scars long, divergent, separated by a wide or narrow ridge having i t s origin.-a short distance forward of the apex; adductors small, borne on the median ridge; adjustor impressions usually long and tenuous, situated on the outside margins of the diductors. Dorsal interior: Cardinalia large; brachiophores scarcely separable from their supporting plates, vertical, or nearly so, strongly divergent, continued forward slightly as a ridge along the l a t e r a l margins of the muscle f i e l d ; cardinal process in young shells l i k e that of Rhipidomella, but i n old shells largely resorbed, making a narrow ridge. In old shells an elevation i s frequently formed on each side of the cardinal process i n the notothyrial cavity. Muscle area quadripartite, the anterior pair of diductors being separated from the posterior pair by oblique ridges extending antero-laterally from the median ridge; peripheral margins thickened and elevated i n some species. P a l l i a l sinuses prominent, six in number, four of these taking their origin at the anterior extremity of the median ridge, starting as two trunks, then dividing into four and extending anteriorly i n a subparallel arrangement, repeatedly branching near the anterior margin into subsidiary rami. Two other trunks originate, in some species, at the end of the ridge dividing the adductors, passing antero-laterally, bifurcating near the margin and then becoming arborescent at the margin. GenoholOtype: Range:  Conchyliolithus Anomites resupinatus Martin  Silurian (Clinton) to Pennsylvanian, with a very wide geographic distribution.  Distinguishing Characters: Schizophoria i s distinguished by i t s convexoconcave profile, the divergent or subparallel diductor scars i n the ventral valve separated by a low median ridge (euseptoid) which bears the adductor marks, and i n the dorsal valve by the widely divergent crural apparatus  57. c h a r a c t e r i s t i c muscle m a r k s , and p a l l i a l t r u n k s . The a d d u c t o r m u s c l e s are s e p a r a t e d b y a c u r v e d , o b l i q u e r i d g e , a f e a t u r e w h i c h a t onces s e p a r a t e s t h i s genus f r o m P r o s c h i z o p h o r i a . 'Aie p a l l i a l marks c o n s i s t o f f o u r or s i x s u b p a r a l l e l t r u n k s . S c h i z o p h o r i a c l o s e l y resembles H e b e r t e l l a e x t e r n a l l y , b u t the fundamental d i f f e r e n c e i n s h e l l s t r u c t u r e and c a r d i n a l i a s e r v e s t o d i f f e r e n t i a t e them i m m e d i a t e l y . The s i m i l a r i t i e s and d i f f e r e n c e s between O r t h o t i c h i a and t h e genus under d i s c u s s i o n a r e p o i n t e d out under t h e f o r m e r g e n u s . "  SUlMMOaU  O. 4>  tha baaV or tha p*41ol* vulva and aoa.tlaaa touching or oloalng ovar tha baa* or tt* pauiola valva ooaplataly, aaeVlng tha dalthyrium and aort or tha oardinal araa of that valva.  "urfaoe or both vulva. ornaa*nt*4 by rin* roundaa coatue, about riva occupying tue "pace or £ am. Ihey ara oroaaaa by atrong groato SCHIUifHOKU .U..NI larran (1W44) l i r e , aaich ara apt to baooaa croadau naar t a . aarrtn, S.'., Trana.Boyal 'oo.uan. ,i>ro arlea. front margin of »a» m a l l . ajatteiwu larg* Vol. aa, % e t ' n . IT, 194« oval ^unota ara praaant on tha ooataa. c  Ihia oneiaerable aea.iginartt -Un- •»**•» ra»e i.bltnoa to M**va LTiMttr.Mtt. a*p*elaUy HaaaaiaM.ni «h«ll l«p », unequally bl-oonvex, in tha ahap Ma.v'a • or tn* vulva. than •ubquadrat. or rounded, greute.t *idta about apaoiaa, noaaver, l a brachial alaay* longer aid* tha ald*lengtn or anterior to ta. nid-length and tha ourvature or tna uabonea or tha breohof tit. ahell, length and width about e^uul. l u l valva 1. greatar. ahereae i t appear, to f.'.«.ur.rent. of tare, v n l m n i nr.: length i t ba cartaln taut tnara ara vurletlea or •*. aocma,, ST mm., und 86 ma.; aldth 3.4 ma., Z.i mm., larlanal i n taa Upper iavonlan, tha only true und a.6 am, ; thlc na». t.4 aw., e. t am., bud JUJ— apaolman i n our collection i« : rem tha Kid41. bovonien. ma. t  v  ledlole valve moderately oor.T.z in region or uabo but flat about the middle or tie K a i l , where a aid. mallow alnua ooevnenoew to form which qulC'ly deepen*, beooner angular, and extend, up Into t i l . brachial vulva at the margin a* u nl a •harp, angular projection. .Un, a l i r a ahort, about half to* aldth or the m e l l . Cardinal araa, broadly triangular; delthyrium higher than alda; bea e • not or .lightly incurved. fc  v  braonlal valve T.ry glbboua, atrongly arohad froa tha ba«v to tha ant.rlor margin. Trenaver.ely, tha graatart ourvuture la along tha mlc11 na of tt* "hall, tha alda. or tha vulva, railing aaay "hardly to tha lataral margin., fleev-e .mail and atrongly lnourv.d, tha araa baalnd tha baa*, atrongly inflated, aoaatla** projecting beyond  mere i a a variety or mutation or g.allacl ahioh dlffara frcm taa apaoiaa i n h a v i n g t t e ^ ^ brao iial valva a l i t t l e l e . « oonvax and taa extension of taa *inua up into tha brachial vulva mora roundec or ilngulold rataar than anarply angular. |aj "ff Lo°»4ftv; b ar l*ivonian. .aterweye formation, «taubuev hlvar. naar UcMurray, alberta. uu  a  JUg.  Uruchlul vulva or a eyntype frontal viaa or a ayntypa  38  lOeUSIS  UrFlK UgVOaleJ BMACMIOPOUA  KM 1 WHOM 1A  ana 17.1 aa. | width 86.b B»., 83.w m., SM •fO.iam.; tnlcsnsss lb.b aa., 14.a aa., aaa 11.b aa. Paaicle valve aoat convei In tha uabonel region, aurisce alepaa repiuly to tha cara. inal margin ana gently to latsral aarglna. Shalloa mesial sinus begins near alaiengta, lncrcasss In aiath ana aaptb anteriorly, as at aaall, polntsa, incurveu, catenae beyond that ol other valve, area oroaaly triangular, gently curved towarj apai, diverging at 46° fro* plane of valve; aeltnyrlua large,twice aa high aa aide. Internally 8 atout ninge teetn diverge slaely and are eupportea by abort dental lea. ellac »hic: continue foraard aa elavatea rid#es oounalng lateral ana anterior aarglae of auacle area. Muscle acara deep, elongate, coranora la outline with alight ejeaial eaarglnatlaa In front! divided longitudinally by rounded a* a l e i Bcnltophorla lowonals Ball (illustrations rlage srlaing shortly In front of bea*, increa•fter itilnbrooi 1940) 1-3. Peaicle, brasing In height and aldth to baae af eaarglnetchial u l anterior via** of • hoaeoytype. Ion, daecendlag abruptly to floor of valve. 4. Poatarior view of a hypo type. 5, 7-b. Brachial, peaicle ana lateral vies os a Brachial valve aore convei, nlgheet In cennypotypa. 6. Interior vlaa of a pedicle tral portion, alopaa aoat abruptly on either valve. 9-10. Paaicle ana brachial vlewe, aide oa beat to cardinal margin; anterior aadreopectlvely, ot t»o apaclacna of tha type lan portion lnaenteo. by sinus of oppoelts valoeecrlbea a* a U . M t ? H t aucorblcularl. we. Bean aaall, pointed,incurves). Area curved, by Hall half height of oppoolto area, llaa la plans ot waive; delthyrium aaall, old* In proportion to height. SCHIZOPHORIA IOWKsBIS Suriece bears numerous, tins, rouadad, radSphliophorle tooonolo Hall (thia description iating ooatae which lncraaae la nuaber by d l B i n Italnbroot (lB40,.Aaer. Bialena lotuvtalon, accoapllahed aeveral tlass; at treat rallat, Val. 03, p. 4b3.) aargln, 8 occupy 1 aa. Intercoetal depreeeleae •ldth greater, leas,or equal to costas. OenDeecrlption—Shall auborbicular In out. centrlc striae ol grooth ot variable strength Una, aubaqually blconvet, elder than long, crooo coetae ana In some opectaeae are oreada* slnuoua at tba front margin, Heaauremanta oi tooara ths treat. thrae hypotypaa are: langth 19.6 an., 19.baa. Occurrence . . . UPPCh IXVOIIAI aWACHIOfOUA oppoelte valve, aresi high, oroaaly wHMp lar, shsrply doflneu at tba el aaa, goatlv oeai, half aa alee aa valve, ctve beneath the bead, allghtly lacllaad toaard oppoelte area. Dslthyrluo narrowly triangular, half aa wie* ao nigh. Bueele scare broadly I label late la outline, anteriorly quadrate with a aedlee eaarglnstion, and laae than half ae long aa the valve, (hoy are sharply defined at the elaee by a bound-In bridge which rleee abruptly froa floor ot valve ana le contlnuoue poeterlorly with the dental laaellae tut obsolete anteriorly near tne aeulen Una. Scare divided loag* ltudlnally by broad, cooaplcuoua, paxtllel•ehlsamhorla lata Stalnbroot, 1940. Aaerlcsn slded ridge which, arising a abort oaf in front audi and laturaTTet, vol. 83, p. 497, pi.8. ot best. 1, 1 , 3, Pedicle, posterior, and brachial vlewe Brachial vulva aore con vet than paalclo. of the holotype. 4,6, Pedicle and lateral Most prominent In uabonel region, whence eurvleee of a aaall paratype. tace elopee abruptly to cardinal aargln and with moderate rapidity to tne lateral and SOHIIOPHOHIA LATA anterior aarglna. Oeprteeae toaard cardinal eitremli.es ana flattened eeelally. Beat blunt SBhlaonhorla lata Stalnbroot. 1940 Aaarlcan allghtly inclined tosara opposite oeat. Hid I sua i a t u r s T l s t , vol. 23, p. 468, Suriscs aartaa by nuaeroua radiating coatas increeeing by divlolon end eeparatea oy epacee • M i l lasqually biconvex, tranaversely euboi variable olatn, ueually narrower than e l l l p t l c a l la outline with rounded poatero and antero-lateral aarglna, considerably elder than coatee. Approiiaately two cootaa per aa. at long, broadest at aldlength, moderately alnuoua front aarglne of mature ehalle. A foa cascent r lc grootn linee occur et Irregular laterla froat. Dimensions of the holotype ere; vale but are aore coaaon near tbe troat at langth, 37.5 aa.; aldth,37.1 aa.| thlcknaea, 16 aa.| width of area 18.6 aa.; distance froa tne anelle. Oblong punctae are ecat tared over tne ourtace oi the valves on the oreota of tha beak to beat 3.7 as. Pedicle valve gently convst, nlgheet a l i t t l e coetae and are aore nuaeroua near toe llaea at lBcreeaat. anterior to beat, surface eloping rapidly froa Much larger than B. lowenele, wider and thuabo to cardinal aarglna and gently and evenly to the lateral aarglna. A mesial sinua origla- inner, all tare internally la tbe character ot atee at the aldlength, aldona and deepens toaard •eaten ridge at pedicle valve. Subelllptlcel shape aad proportionately broaoer shell distba front, where it attains a aldth halt that tinguish this fora froa S. laudonl. Stall ax of thai valve. Uabo low, broadly convei froa to S. etrtetule war. auetralte Kindle la gaaareide to elde, aad increasing in height toward tba beat. Beat large, pointed, a U t i l e incur- al ehaa* but la not aa largo, baa flaw cootaa aad conetderafcly higner area. vlng, elevated, and attended beyond that of  Superfamily Pentameracea. (Shrock and Twenhofel, p, 5^5 )•  59.  "The pentamerids are typically large biconvex impunctuate shells with a spondylium duplex and usually a cruralium or two parallel vertical plates i n the brachial valve. The hinge line i s narrow, interareas small, and surface smooth or costate." Range: Middle Ordovician to Devonian. Genus Gypidula  Rail  Genus Pentamerus  Hall  Reported occurrence of this genus i n the literature reviewed i n Part I of this thesis. Genus Gypidula Hall G. *G. G.  comis  10, 24, 52, 55.  Owen  8.  cornuta Fenton and Fenton galeata  Dalman  11, 25.  Genus Pentamerus *P.  borealis  Meek 1.  22, 57, 58.  4o Genus GYPIDULA Hall n. gen. Hall, N.Y. State Cab., 20th Rept., 1867, p. 163 "Exterior: Galeatiform, hinge-line short and straight; cardinal extremities rounded; lateral profile biconvex, the ventral valve usually having the greater convexity. Anterior commissure rectlmarginate or sulcatej the ventral fold usually low and defined at the anterior only. Ventral interarea very narrow, defined by low ridges, curved, apsacline to anacline, delthyrium large, open; beak pointed, incurved strongly; umbo inflated. Dorsal Interarea obsolete; beak pointed, incurved; umbo swollen. Surface smooth or multicostate; shell substance fibrous impunctate. Ventral interior: Delthyrial cavity deep; teeth strong, narrow, elongate; dental plates convergent, forming a narrow spondylium, supported by a duplex septum for part of i t s length; free at the front end. Septum short. Dorsal interior: Notothyrial cavity deep; crural apparatus consisting of three pairs of plates intimately united. At the posterior are two plates slightly convex inward, uniting with the poster-doraal wall of the valve at the back and their dorsal or distal edges uniting with the brachial supports. These form a sort of hinge-plate. The sockets are excavations i n the lateral edges at the junction with the wall of the valve. A second set of plates are set off from those above by ridges. These are vertical, narrow, elongate bands with their front ends free, and are supported by septa which converge inward and unite directly with the wall of the valve. Cardinal process simple, absent, or present i n some species. The diductors are usually borne i n a narrow pit under the beak. A low septum divides the space between the septal plates into two, and on each side of the ridge obscure adductor impressions are v i s i b l e . GenolectOtype: Range:  Pentamerus Occidentalls Hall  Silurian and Devonian of North America and Europe.  Distinguishing Characters: Gypidula i s most readily recognized externally by i t s galeate from and the position of the fold on the ventral valve. Internally the differential characters are i n "the dorsal valve, i n the discreteness of the brachial supports, which form a double track on the dorsal surface when the shell i s eroded or seen i n section."  41  —  f B B M MBM  •">**»> end «<ton i92i.. r  renter, and Fan ton (192U) Mich. Univ. Naa. Gaol., Contrlb. vol. 1, p. 121, pi. 25, fl«a. 26-31. 0TPIDUL1 CCWIUTi ranton and I'm-tor. DaecrlPtlcai Shall of medlua alsa or laaa, wider than long lo younger epecimena and longer than wide la old one.. Diaanalona of three apaelaana, tha aaeond of which la tha holetype i length of padiele valva, 16.7 an., 21.9 am., and 23.6 mm.) length of brachial valva, 15.5 an., 16.9 aa., and 19.5 aa.| aldth, 19.2 aa., 21.» mm.. and 23.) am.; thlokneae, 9.2 aa., lit.6 mm., and 16.2 am. Pedicle valve highly convex) beek large prominent, aharply pointed, atrongly incurved.  Cardinal araa broadly triangular, etro-.gly aveaadl padicla opening aaaa only la young apaal triangular and about aa high aa aide, rag1 or high) aaatara-lataral alopae ellghtly flattened and concave) lateral alaaaa daacead abruptly fraa the aaeial portion, anterior Berg la elnuate. Meal a fold originate, about 1C aa. rroa the beak end la loa and broad, or narrow ad araelaeati aearealy dietlngwlahabla In aaall apeelaaaa elnce they are quite flet. ca tha fold if* I ar 3 laa rounded pllctior.s separated by moderately bread ahalloa farroaa. Lateral alopaa of largo apaelaana eaecth cr aarked by 2 or more low rounded pllcationa. Brachial velve aoderstely convex in uabonal ragloai bear pointed, ellghtly Incurved In aaall apaelaana but beneath the seek of oppoelte valve la mature one a. Cerdinol area vary low and alight ly arched. Uabonal aree mo.1ernt.ly convex; poaterolateral alopaa flattened and ellghtly concave. Surface of both velvea narked by fine concentric linaa and heavier growth wrl.kleo. Dlagrxaoi 1. Ventral view. 2. Dora, view. 3. Latarn. view.  42. Genus PENTAMERUS Sowerby, n.gen. 1859 Hall (1894), Nat. His. of New York. Vol VIII Part II p.2J2. "Shell8 elongate-subtrigonal or subpentagonal i n outline, strongly inequivalve, biconvex: median fold and sinus faint, i f at a l l developed. Anterior margins of contact usually straight, with sometimes a faint fold, at others a low sinus on both valves. Surface with numerous sharp or rounded, simple or divided plications extending from beaks to margins; cardinal slopes broad and usually smooth. .. In the pedicle-valve the umbo i s elevated, attenuated, more or less incurved, not prone upon the opposite valve. No cardinal area i s developed. The delthyrium i s very broad and bears a concave deltidium, which, however, i s frequently wanting. Teeth small, supported by convergent lamellae which unite i n the interior cavity and form a single median vertical septum of variable length; i n the typical species usually extending almost, and sometimes quite to the anterior margin, and vertica l l y , for f u l l y one-half the depth of the combined valves. The spondylium i s very narrow and deep; combined with the median septum the height of these plates equals f u l l y two-thirds of the depth of the valves. The anterior margins of these plates are doubly incurved, the most projecting points being at the base of the septum, and at i t s line of union with the dental lamellae. The median septum consists of two vertical lamellae, each continuous with one of the component plates of the spondylium. The spondylium was the seat of muscular attachment and i t bears a series of fine radiating lines along i t s median portion, and transvers or concent r i c lines over i t s lateral slopes; the former probably representing the scar of the adductor, and the latter the impressions of the diductor muscles. In the brachial valve the beak is obtuse and closely incurved into the deltidial cavity or spondylium of the opposite valve. The dental sockets are long and narrow, their inner margins being bordered by two broad, convergent crural plates, which extend toward the bottom of the valve, but do not reach i t . These Sloping plates are supported by two vertical septa, with which they are united, not at their extremities, but obliquely, just within their free edges. At the anterior angles of these free edges, there are two long, straight or slightly curved, rodlike crural processes extending into the anterior cavity of the shell. Beneath the beak i s a faintly developed, bilobate or multilobate cardinal process. The muscular scars l i e on the surface of the valve between the two vertical septa, and extend for some distance i n front of them. They are divided by a low axial ridge. Shell-substance fibrous, impunctate." Type, Conchldium blloculare. Linne  (-  Pentamerus conchidlum Dalman)  43  UKVtiN.lt, W » U I | . n \ » i .  rather vantrisosa, and closely lncur»ad, SS ss ts bring the point m a r l y or quits In eontac' sits, tha umbo of tha otiiar valve. Surfaca a1th rather small, irrsgular, distinct radiating cost**, whlah Increaaa by division, ssoh of ths principal ansa, particularly on tha aidas of tha vslvaa, giving off one or mora smaller ribs on ths outer alas, which never equal theothers in s l i s . Lsngth froa ths front to the bask of tha iorsal vslvs, 0.97 inch) do. to tha moat rroaiasnt part of the umbc of the ventrnl valve, 1.13 inches! greatest breadth, 1.05 Inches) convexity of ths two valves, 0.91 inch.  rWTAxana BCRIALIS Meek (186S)  Trans. Chic. Acad. S c i . V o l . 1 . p. 9 3 . PWTAHERU3 BOfiiAl.13 Mask Deacrlptioni Shell aubglohoas, about aa wide as long. Dorsal valve moderately convex, Being moat prominent i n the central and umbonal regional beak Incurved, and not projecting much beyond tha cardinal Margin, which la rathar atralght) front depressed so aa to form a ah a How, flattened mesial sinus, extending but s abort distance hack from the margin. Ventral valve more glbboua than ths othsr, particularly In tha umbonal region, forming a nearly regular deacending arch froa the beak to tha froat, where there l a a alight, flattened mesial pror nance, causing a moderately distinct sinuosity in tha margin, occupied ny a corresponding projasticti of tha edge of turn othsr velvej beak prominent.  Localityi  Andersen river.  Dlagrnmsi  1. 2. 3. u.  Devonian \Hamilton group).  Dorsal visw '.'antral view Side view. Anterior view.  44. S u p e r f a m i l y Strophomenacea  ( S h r o c k and T w e n h o f e l , p . 325) -  "Strophomenids have f l a t t r a n s v e r s e c o s t e l l a t e s h e l l s w i t h a p r o f i l e t h a t may be c o n c a v o - c o n v e x , c o n v e x o - c o n c a v e , o r r e s u p i n a t e . The s h e l l i s pseudopunctuate. The p e d i c l e o p e n i n g , i f p r e s e n t , i s an a p i c a l foramen i n a d u l t s h e l l s , but t h e p e d i c l e seems never t o have emerged t h r o u g h the d e l t h y r i u m because i n young s h e l l s i t p r o t r u d e d t h r o u g h a t i n y s u p r a - a p i c a l foramen, surrounded b y a s h e a t h and a n t e r i o r l y s i t u a t e d w i t h r e f e r e n c e t o t h e d e l t i d i u m . Commonly the p e d i c l e a t r o p h i e d and t h e s h e l l l a y f r e e on t h e bottom o r was attached by p a r t o f the surface of the p e d i c l e v a l v e . A d e l t i d i u m and a c h i l i d i u m were u s u a l l y w e l l d e v e l o p e d , and s h o r t b r a c h i o p h o r e s supported the lophophoreThe Strophomenacea were an i m p o r t a n t and p r o l i f i c group d u r i n g the P a l e o z o i c , b u t s i n c e t h e n have g r a d u a l l y d e c l i n e d u n t i l now o n l y two l i v i n g genera remain.™ Ranges  Lower O r d o v i c i a n t o R e c e n t .  Genera D e s c r i b e d :  Range:  I . Genus D o u v i l l i n a O e h l e r t  Devonian  I I . Genus D o u v i l l a n a r i a S t a i r i b r o o k I I I . Genus L e p t a e n a Dalman  Middle Ordovician to Mississippian.  1 7 . Genus L e p t o s t r o p h i a H a l l and C l a r k e . V . Genus N e r v o s t r o p h i a C a s t e r .  Devonian.  V I . Genus S c h u c h e r t e l l a G i r t y .  V I I . Genus Strapheodonta  Lower D e v o n i a n .  Lower Devonian t o Permian.  Hall.  Devonian.  V I I I . Genus S t r o p h o n e l l a H a l l  Middle S i l u r i a n Devonian.  to  Reported occurrences of t h i s s u p e r f a m i l y i n the l i t e r a t u r e reviewed i n Part I of t h i s t h e s i s . I . Genus D o u v i l l i n a O e h l e r t D. arcuata H a l l .  37.  * D . d e l i c a t a F e n t o n and F e n t o n . I I . Genus D o u v i l l i n a r i a  Stainbrook  D. v e r i b i l e s C a l v i n .  37, 38.  *5. I I I . Genus 3Le.ptaena Dalman L . rhomboidulis Wilckens.  11.  17. Genus L e p t o s t r o p h i a H a l l and C l a r k e !>.. M a g n i f i c a  Hall  V . Genus N e r v o s t r o p h i a C a s t e r H . r o c k f o r d e n s i s F e n t o n and Fenton N. v e s i t i t a V I . Genus S c h u c h e r t e l l a G i r t y . S. a r c t o s t r i a t a  1 1 , 1 2 , 2 1 , 2k,  Hall.  22.  * S. chemungensis C o n r a d . * S. g i r t y i S h i m e r .  1 8 , 2 2 , 37*  * S. n e v a d e n s i s M e r r i a m . * S. p a r v a S t a i n b r o o k . V I I . Genus S t r a p h e o d o n t a  37* 38•  Hall  * S. c o s t a t a S. demissa  s. d o r s a t a • S. S.  halli inequistriata  S. I n f l e x a S.' i o w e n s i s S. perplana  s. p l i c a t a s. aubdemissa s. umbonata s. p a r v a V I I I . Genus S t r o p h o n e l l a H a l l .  9, 2 1 .  37.  29,  31,  32,  35.  46. Genus DOUVILLINA Oehlert 1887 emended Williams (1953) North American and European Stropheodontidss Morphology and Systematics, p. 43*  Their  "Exterior: Outline semicircular to elongately semi-oval, mucrcnatej concavo-convex, with a varying strength of curvature but usually strong. Ventral interarea apsacline to orthocline in the later stages of stock development, dorsal interarea correspondingly anacline to hypercline, delthyrium progressively closed by pseudodeltidium which never loses the sharp median fold, chilidium initially large'j progressively degenerate, in later stages vestigial. Unequally parvicostellate with incipient secondary costation represented by fine sharp folds usually along the primaries in end stock members. Pseudopunctae radial but very closely spaced in late forms. Ventral Interior: Hinge line progressively denticulate; in late forms, portions of the denticulate area on either side of the umbo became isolated (secondary pseudoteeth) and fitted behind the laterally expanded cardinal process lobes; no dental plates. Process pits progressively deeper, strongly excavate in late forms; ventral process prolonged anteriorly into a median ridge, progressively stronger but never losing posterior concavity nor developing pseudoteeth. Muscle scar small, quadrate to subcircular in late forms; adductor scars lanceolate impressed on either side of the median ridge, diductor scars short bounded by strong lateral walls which fuse with a progressively developed transverse ridge anterior to the muscle scar area and with i t eventually forming a shallow sub-circular cup. Dorsal Interior: Cardinal process lobes initially rather elongate, conjunct, attachment faces directed postero-ventrally becoming progressively stouter and more disjunct; in ultimate forms deeply disjunct, directed posteriorly, each lobe expanded laterally. Socket plates abbreviated to obsolescent. Adductor scars initially lightly impressed on either side of the median ridge, bounded by faint curved lateral ridges and divided by a pair of low ridges diverging at a small angle and lying on either side of the median ridge. In later forms, scars progressively more deeply impressed, bounding walls higher, lateral ridges, high, tuberculate (braceplates) curving towards each other, each uniting posterocentrally with a branch of bifurcated strong median ridge. Genotype: Range:  Leptaena dutertrei Murchison  Middle Silurian to Upper Devonian.  DJMTjlTl  and vartxeali a n t e d aa 1* t2aa of tea) ejaaaalta valve. Surface of bote valves aarkad by coma angular costao. the eoataa are crcaaaday aery fine Irregular concentric rtrla) ahlukfoja nodes on the coatee., the aarfeee appears te be panctate. Rexaurasi Ihle apeolaa dUXex* acraanTly from the other Jbxerlcsn f araa of tola genua l a alae, degree of convexity, end ooaraenaae of plication*, fixe In.emal chareetara carve to aatebllati tha genua.  noprnm, DJBJCaTa Fenton aid Fenton. Futon «nd Fenton (13210, IHelu Univ. Has. Gaol. Costrib., v o l . 1, p. 91, p i . 20, f i g s . 17-20.  DlagrexBi  DOWmJHl PHLICrta Fenton and Fenton Jot^^r^^^^ 1 median sice; eeBnTcuvuTar l a outline, broader than lone with toe greatost aldth near the old-length) posteriorly there l a an Incurring of the aargln ahich givea tha hinge l i n e a ourconata appeal auta. Diawnalonfl of one specimen) length, 19.5 savj aldth, 21.9 an.f thickness, $.2 BB.) height of cardinal area, 1.8 oak 1  Padlnla valva mdarately convex) mjslal fold l e v and luuuded. Cardinal area hnrlsontal and landaiataly loaj aazted by fine v e r t i c a l atTriae, ara crossed by coarae hcrxaontal U n a s . Oalttayrlni f l a t , triangular, aarfcsd by ftno growth lenellaeu Brachial valva " iln otaly concave] aealal atoaa s h a l l or and very I n d i s t i n c t l y hormrhwi. Cardinal araa llnear 1  1. Ventral viae. 2. Ooraal viae.  48 Genus DOW ILLINARIA Stainbrook, n.gen. Stainbrook (1945), Rrachiopoda of the Independence Shale of Iowa. "Shell small, thin, concavo-convex, broader than long with greatest width generally at midlengthj subquadrate i n outline with antero-lateral and front margins broadly rounded, postero-lateral margins concave and hinge-line less than greatest width, sometimes considerably so; angles slightly projecting, and anterior commissure sulcate. Pedicle valve depressed convex, highest anterior to midlength, surface arching gently from the beak over greater portion of the valve but more strongly near front and lateral margins. Median fold strongly to weakly developed, originating at beak, angular, and sometimes causing an emargination at front. Umbo low and very gently convex. Beak small, scarcely projecting. Cardinal area low, apsacline, slightly curved, vertically marked by strong narrow ridges which decrease i n size and height to a point about midway to extremities; upper ends of ridges directed toward beak. Remainder of area horizontally striated; i n some examples i t may be smooth or but slightly ridged. Delthyrium covered by a high narrow convex deltidium which may be open a l i t t l e at base. In many examples there i s a hole on either side due to wear caused by prongs of brachial process. internally border of valve adjoining cardinal area strongly denticulate; denticulae short, parallel, strongly convex projections, the inner extensions of ridges on exterior of area. Denticulae decrease i n size to a point a short distance from hinge extremity. Hingeteeth apparently not developed. Delthyrial cavity nearly f i l l e d by a median ridge which bifurcates anteriorly; each lateral arm forms the posterior border of a diductor scar while the median portion appears to touch under surface of deltidium. On each side of posterior end of median ridge i s a deep bulbous cavity in which an arm of brachial process articulates. Muscle area small, semicircular i n outline, about a third as long asvalve; bordered on each' side by a narrow ridge which originates a short way lateral to base of delthyrium, rises from floor of valve to i t s highest point on antero-lateral margin of muscle area, and, curving inward, decreases i n height to i t s junction with the median ridge. These thin lateral ridges, deeply excavate anteriorly and laterally, outwardly overhang floor of valve to form a structure similar to that of Douvillina. Median septum arises in front of adductor scars, increases in height to junction with lateral ridges, and then descends abruptly to floor of valve. In some instances septum may be continued forward a short way. On each side of septum where joined by lateral ridges i s a slight depression to accommodate a brachial braceplate. Muscle scars are seldom distinguishable as they are not strongly impressed on surface. Posterior adductors are radiately grooved and appear to be crescentic while the adductors are narrow and elongate. Ridges bordering muscle area are strongly papillose externally. Papillae large and resembling incipient endospines.  49 Genus LEFTAENA ' Salman, 1828, n . g e n . I n H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , V o l . V I I I , p t . 1 . p . 2 7 6 . " S h e l l s p l a n o - c o n v e x when young, concavo-convex a t m a t u r i t y ; c o n v e x i t y normal. Surface covered by conspicuous c o n c e n t r i c c o r r u g a t i o n s o r w r i n k l e s o v e r t h e f l a t t e r p o r t i o n s o f t h e v a l v e s . Where t h e s e cease t h e s u r f a c e i s more o r l e s s a b r u p t l y and o f t e n r e c t a n g u l a r l y d e f l e c t e d , f o r m i n g a c o n s p i c u o u s a n t e r i o r s l o p e . The whole e x t e r i o r i s c o v e r e d w i t h f i n e , even, r a d i a t i n g , t h r e a d - l i k e , t u b u l a r s t r i a e , w h i c h , i n w e l l p r e s e r v e d specimens, are c r e n u l a t e d b y f i n e r c o n c e n t r i c striae. O u t l i n e , transverselysubquadrate or s e m i o v a l . H i n g e - l i n e s t r a i g h t , i t s l e n g t h making t h e g r e a t e s t d i a m e t e r o f the s h e l l ; extremi t i e s often subauriculate. C a r d i n a l a r e a n a r r o w , s l i g h t l y w i d e r on the p e d i c l e - v a l v e , not d e n t i c u l a t e . I n t h e p e d i c l e - v a l v e the d e l t h y r i u m i s c o v e r e d b y a convex d e l t i d i u m , p e r f o r a t e d a t the apex b y a foramen w h i c h i s c l o s e d at m a t u r i t y o r encroaches upon t h e apex o f the v a l v e . T h i s d e l t i d i u m i s most c o n s p i c u o u s l y d e v e l o p e d i n e a r l y s t a g e s o f growth t h e n h a v i n g t h e form o f a tube o r s h e a t h , w h i c h c h a r a c t e r becomes o b l i t e r a t e d as m a t u r i t y a p p r o a c h e s , b y the i n c r e a s e i n the s i z e o f t h e c a r d i n a l p r o c e s s o f the o p p o s i t e v a l v e , and the c a l l o s i t y formed about i t s b a s e . I n a d u l t s h e l l s t h e foramen has become e n c l o s e d b y t h e s u b s t a n c e o f the s h e l l , i t s e x t e r n a l opening b e i n g an o b l i q u e groove i n f r o n t o f the apex o f t h e v a l v e , and i t s i n n e r a p e r t u r e a p p e a r i n g i n f r o n t o f t h e p e d i c l e s c a r . Not i n f r e q u e n t l y the passage i s c l o s e d a t m a t u r i t y . The t e e t h are v e r y d i v e r g e n t and q u i t e c o n s p i c u o u s , g e n e r a l l y s u p p o r t e d b y l a m e l l a e w h i c h a r e c o n t i n u e d around the s u b c i r c u l a r m u s c u l a r area o f the n a r r o w umbonal c a v i t y . The m u s c u l a r s c a r s c o n s i s t o f a narrow median or adductor, enclosed by f l a b e l l i f o r m d i d u c t o r s . I n the b r a c h i a l v a l v e t h e a r e a i s l i n e a r , t h e d e l t h y r i u m i s p r o g r e s s i v e l y f i l l e d b y the growth o f a c a l l o s i t y , w h i c h i s o f t e n d e e p l y grooved a l o n g t h e c e n t e r , and sometimes p e r f o r a t e d i n t h e l i n e o f d i v i s i o n between t h e b r a n c h e s o f t h e c a r d i n a l p r o c e s s . The c a r d i n a l p r o c e s s c o n s i s t s o f two s e s s i l e , d i v e r g i n g apophyses w h i c h have b r o a d , f l a t , s t r i a t e d s u r f a c e s o f a t t a c h m e n t , and a r e extended beyond t h e h i n g e - l i n e . The s o c k e t s are m o d e r a t e l y deep; the c r u r a l p l a t e s are u s u a l l y not s h a r p l y d e f i n e d , but are continued i n a c u r v i n g l i n e along the i n n e r surface of t h e v a l v e , p a r t i a l l y embracing a p a i r o f b r o a d , ovate m u s c u l a r i m p r e s s i o n s w h i c h a r e marked b y a r b o r e s c e n t r a m i f i c a t i o n s ; r e c u r v i n g and a g a i n i n c u r v i n g , these r i d g e s p a r t i a l l y surround a p a i r of s m a l l e r muscular areas, l y i n g i n f r o n t o f the f i r s t . A t the i n n e r base o f each b r a n c h o f t h e c a r d i n a l p r o c e s s t h e r e a r i s e s a l o w e l e v a t i o n or c a l l o s i t y , w h i c h , e x t e n d i n g o b l i q u e l y f o r w a r d , and u n i t i n g i n t h e c e n t e r , c o n t i n u e s as a narrow median r i d g e d i v i d i n g t h e p o s t e r i o r p a i r o f m u s c u l a r i m p r e s s i o n s . T h i s r i d g e sometimes t e r m i n a t e s i n a p o i n t n e a r t h e b a s e o f t h e f i r s t p a i r o f i m p r e s s i o n s , and t h e second p a i r a r e s e p a r a t e d b y a l o t : , slender median septum, w h i c h sometimes a p p a r e n t l y t a k e s i t s o r i g i n at t h i s p o i n t , b u t w h i c h i s i n f a c t a. c o n t i n u a t i o n from the i n t e r r u p t e d p o s t e r i o r r i d g e , and extends f o r some d i s t a n c e over t h e p a l l i a l r e g i o n .  50 Remainder of valve marked by abundant papillae which are large near muscle area but smaller farther away. Slight p a l l i a l markings obscured by papillae radiate from muscle area. Depression below median fold i s apparent on anterior half of valve only. Brachial valve concave to nearly f l a t , umbonal region convex, occasionally strongly so, and highest anteriorly. Median sulcus originating near beak, subangular at bottom, narrow, and generally sharply depressed below remainder of valve. Area low, a l i t t l e more than baif as high as that of pedicle valve, f l a t , catacline, similarly marked by vertical ridges but they are narrower and interspaces broader. Chilidium narrow and gently convex. In the neanic stages brachial valve i s convex but this condition i s reversed when the shell i s about one-third adult size. Internally brachial process well developed, strongly bifurcate; each prong b i f i d and posteriorly curved beyond cardinal area. On each side of process i s a short thin erect ridge, the brachiophore, l a t e r a l l y directed and attaining highest point at anterior end. Edge of area marked by strong denticles which are absent toward the extremities. Immediately in front of the process arises a strong median ridge which bifurcages about half way to midpoint and i s deeply grooved there. Each arm or braceplate extends laterally and then anteriorly for a short way, disappearing abruptly at midlength. They are thin and inwardly slanted so as to partially enclose a deep cavity in which are the anterior adductor scars. Between these scars a slight ridge extends forward up onto ridge formed by inward reflection of the external sulcus. Posterior adductor scars larger, separated by posterior median ridge, and having no definite lateral bounding structure. Region immediately adjacent to scars depressed to form a definite visceral area. A radially grooved ridge i s formed near front and lateral margins by thickening of valve; beyond this, the shell i s thin. Surface has abundant papillae, those in visceral area larger and longer. Exterior of both valves marked by numerous radiating costae which increase by intercalation. They are thin, acutely angular, variable in size as every fourth or f i f t h i s larger, and widely separated. In the interspaces are from three to six fine costellae. Numerous minute wrinkles of growth cross costae and may give them a rugose appearance." Genotype:  Strophodonta variabilis Calvin  Described by Williams (1953), Geol. Soc. Am.,  Mem.  56, p. U5*  "This genus includes a third divergence from the douvillinids which has been affected by resupination. The relationships, however are complex and render the group distinct from the douvillinellids. In the f i r s t few millimeters of growth, the valves have normal concavo-convex relationship; this growth i s superseded by a convexo-subplanate condition; and i n maturity the concavo-convex condition returns. Specimens were accordingly truly biconvex for much of their lives, which i s unusual in  51  stropheodontids. Again there i s every indication that this stock originated from a normal low-convexity douvillinid radicle just prior to or during the deposition of the Independence shale.™ Genotype: Stropheodonta variabilis Calvin  52. Genus liEPTOSTROPHIA H a l l and C l a r k e , n .  genus.  H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , 1892, V o l . V I I I , p t . 1. p .  287.  "The p l a n o - c o n v e x s p e c i e s o f S t r o p h e o d o n t a are d i s t i n g u i s h e d from t h e group o f S. demissa b y more than c o n t o u r a l o n e . The c h a r a c t e r s of the d e l t i d i u m show the same p r o g r e s s i v e development as i n the c o n c a v o convex S t r o p h e o d o n t a s , the e a r l i e s t s p e c i e s h a v i n g the d e l t h y r i u m somet i m e s open, sometimes p a r t i a l l y c l o s e d b y a convex p l a t e ; w h i l e i n the Devonian s p e c i e s t h e d e l t i d i u m i s r e d u c e d t o a f l a t , t r a n s v e r s e l a m i n a , s u p p o r t e d w i t h i n b y t h e c a l l o s i t y about t h e c a r d i n a l a p o p h y s e s . I n the p e d i c l e - v a l v e a r e two v e r y s t r o n g l y p u s t u l o s e , d i v e r g i n g r i d g e s , b o u n d i n g the m u s c u l a r i m p r e s s i o n s on t h e i r l a t e r a l m a r g i n s , w h i l e a n t e r i o r l y t h e s e s c a r s a r e b r o a d l y f l a b e l l i f o r r a and n o t s t r o n g l y l i m i t e d . The c e n t r a l a d d u c t o r s are s m a l l , r e l a t i v e l y obscure and n o t d i v i s i b l e . S h o u l d i t be found d e s i r a b l e o r i m p o r t a n t t o r e c o g n i s e the v a l u e o f t h e c h a r a c t e r s above i n d i c a t e d , t h e s e forms may be s e p a r a t e d under t h e t e r m L e p t o s t r o p h i a . Genotype:  Stropheodonta m a g n i f i c a ,  Hall.  55. The m u s c u l a r a r e a , when i t s f e a t u r e s are most d i s t i n c t l y r e t a i n e d , shows a s u b d i v i s i o n i n t o t h e f o l l o w i n g s c a r s : (a) A l a r g e p o s t e r i o r p a i r ( t h e p o s t e r i o r a d d u c t o r s ) , the s u r f a c e o f w h i c h i s covered w i t h arborescent r i d g e s , the a n t e r i o r p o r t i o n o f each o f t h e s e s c a r s i s smoother t h a n t h e r e s t , g e n e r a l l y much t h i c k e n e d and o f t e n e x t r e m e l y e l e v a t e d a t i t s o u t e r m a r g i n s . These may be r e g a r d e d as a c c e s s o r y elements o f t h e p o s t e r i o r a d d u c t o r s , (b) An a n t e r i o r p a i r ( a n t e r i o r a d d u c t o r s ) , s i t u a t e d c l o s e t o g e t h e r a t about the c e n t e r o f t h e valve. The p o s i t i o n o f t h e s e i s g e n e r a l l y w e l l d e f i n e d b u t t h e i r o u t l i n e i s f r e q u e n t l y obscure, ( c ) An e l o n g a t e , narrow median s c a r , w h i c h i s apparently d i v i d e d f o r i t s e n t i r e l e n g t h by a f a i n t r i d g e . In front o f t h e m u s c u l a r a r e a t h e r e a r e o f t e n a number o f s h o r t p r o t u b e r a n c e s on each s i d e o f t h e median septum, and the a n t e r i o r p a i r o f s c a r s i s f r e q u e n t l y o b l i t e r a t e d b y prominent c a l l o s i t i e s . A t the l i n e o f g e n i c u l a t i o n the i n t e r i o r s u r f a c e i s e l e v a t e d i n t o a v e r y p r o m i n e n t , s h a r p , o r a b r u p t l y rounded c r e s t . S p i r a l c a l l o s i t i e s f o r t h e s u p p o r t o f the b r a c h i a , s i m i l a r t o t h o s e i n D a v i d s o n i a and L e p t a e n i s c a , havebeen observed by D r . Davidson. S h e l l substance s t r o n g l y  punctate."  Genotype:  L e p t a e n a r u g o s a , Dalman = P r o d u c t a r u g o s a , H i s i n g e r = Conchites rhomboidalis, Wilckens  Range:  Upper S i l u r i a n .  5* Genus NERVOSTROFHIA Caster, n. gen. Caster (1939), Bull. Am. Pal. Vol. 2ii, No. 83, p. 79. "This genus based on Stropheodonta nervosa (Hall) i s characterized by exceedingly thin shells which are sub planate, the ventral one being usually only very slightly more convex than the dorsal one, which is in some cases correspondingly very slightly concave. The surface ornamentation of the genotype usually gives a f i r s t impression of hirsuteness, for the principal costellae are conspicuously discontinuous, and irregular i n height where developed. The ornament i s really comprised of delicate radial corrugations of the shell which usually are reflected in reverse on the interior. New r a d i i originate by intercalation. Between the principal r a d i i are usually from four to six very fine undulating r a d i i which also originate by intercalation, but are essentially continuous. The hinge i s crenulated far about two thirds of the width, the crenulations usually diverging from the median line toward the front of the shell. The delthyrium i s closed by a convex deltidium which may be secondarily opened at the commissure plane for the reception of the cardinal process. Internally the ventral valve usually shows prominent paradental lamellae which ordinarily f a i l to reach the palintrope wall. The ventral process i s strongly developed, but the anterior boundary of the pedicle p i t i s usually obscure, and may well be developed as a special feature. The median septum varies considerably i n degree of development. The ventral muscle scars are usually not well defined. They are flabellate area, which i n certain Upper Devonian species of large size are well differentiated by l a t e r a l borders of callous material. The adductors were attached in the Upper Devonian shells to elongate median sub parallel plates or platforms which are separated either by a median septum or by a sharply angular median fossa, which sometimes has a r e l i c t septum at the bottom. In the genotype the adductor scars are ordinarly not well shown." Genotype:  Stropheodonta Nervosa.  Described by Williams (1953), Geol. Soc. Am.,  Mem.  56, p. i l l .  "Exterior: Outline semicircular to elongately semi-oval, hinge line raucronate, concavo-convex and varying from a low to high curvature, with or without a variable ventral median sulcus and corresponding fold. Ventral interarea wide, apsacline to hypercline, dorsal interarea narrow anacline to orthocline, delthyrium completely or almost completely f i l l e d by pseudodeltidium, medianly folded or smooth. Chilidium vestigial or absent. Ornamentation rather finely parvicostellate, variably nervate. Pseudopunctae fine in a close pattern. Ventral Interior: Hinge line rather variably denticulate but generally almost completely so. Process pits deep. Ventral process strong, tapering anteriorly to a fine long median ridge. Diductor  55 muscle s c a r , m o d e r a t e l y l o n g , t r i a n g u l a r ( i n h i g h c o n v e x i t y forms more parallel sided). L a t e r a l bounding r i d g e s d i s t i n c t and v e r y s t r o n g posteriorly, adductor s c a r s e l o n g a t e l y o v a l , i m p r e s s e d e s p e c i a l l y p o s t e r i o r l y d i v i d e d b y median r i d g e . Dorsal Interior: C a r d i n a l process lobes i m p e r f e c t l y to c o m p l e t e l y d i s j u n c t , attachment f a c e s d i r e c t e d p o s t e r i o r l y t o d o r s o posteriorly; s o c k e t p l a t e s p a r a l l e l t o t h e s i d e s o f , and a n k y l o s e d t o , c a r d i n a l process l o b e s . N o t o t h y r i a l p l a t f o r m low, muscle-bounding r i d g e s , s l i g h t l y d i v e r g e n t or s u b p a r a l l e l , h i g h p o s t e r i o r l y ; adductor s c a r s g e n e r a l l y on l o w p l a t f o r m o f s e c o n d a r y s h e l l d e p o s i t w h i c h may obscure t h e median r i d g e . P o s t e r o l a t e r a l areas o f both v a l v e s r a t h e r coarsely tuberculate. Range: M i d d l e Devonian ( L a t e E r i a n ) t o Upper D e v o n i a n r e p o r t e d so f a r from A m e r i c a o n l y .  (Senecan),  Discussion: C a s t e r ' s d e s c r i p t i o n has been emended t o i n c l u d e forms such as L e p t o s t r o p h i a camerata F e n t o n and F e n t o n , L . r o c k f o r d e n s i s Fenton and F e n t o n , and L . c a l v i n i M i l l e r , ( i . e . , s p e c i e s w h i c h C a s t e r w o u l d r e f e r t o S u l c a t o s t r o p h i a C a s t e r 1939), and forms w h i c h S t a i n b r o o k w o u l d i n c l u d e i n h i s genus P s e u d o d o u v i l l i n a , genotype P . e u g l y p h a S t a i n b r o o k . There are no major i n t e r n a l d i f f e r e n c e s between any o f t h e s e g r o u p s , as S t a i n b r o o k (19U5. p . 27) and C a s t e r (1939, p . 81) have a l s o n o t e d , and t h e genera have been based on (a) degree o f c o n v e x i t y a t t a i n e d , (b) p r e s e n c e o r absence o f s u l c a t i o n , ( c ) t h e presence o r absence o f a median f o l d i n t h e p s e u d o d e l t i d i u m . Thus, i n the r e s t r i c t e d use o f t h e s e c h a r a c t e r s as proposed b y S t a i n b r o o k , N e r v o s t r o p h i a embraces l o w - c o n v e x i t y forms w i t h a median f o l d t o t h e p s e u d o d e l t i d i u m . S t a i n b r o o k would p l a c e L . r o c k f o r d e n s i s , w h i c h has a v a r i a b l y developed v e n t r a l s u l c u s , i n t h i s group because i t has a m e d i a n l y f o l d e d p s e u d o d e l t i d i u m ; Caster places L . rockfordensis i n Sulcatostrophia irrespective of pseudodeltidial f o l d . S u l c a t o s t r o p h i a " i n c l u d e s l o w - t o h i g h - c o n v e x i t y forms w h i c h are s u l c a t e and have a smooth p s e u d o d e l t i d i u m , and P s e u d o d o u v i l l i n a h i g h - c o n v e x i t y n o n s u l c a t e forms w h i c h a l s o have a smooth p s e u d o d e l t i d i u m . From a s t u d y o f o t h e r groups, i t appears t h a t none o f t h o s e c h a r a c t e r s i s o f sound g e n e r i c v a l u e . Strophomenoids g e n e r a l l y a r e notorious f o r t h e i r v a r i a t i o n i n c o n v e x i t y even w i t h i n a p o p u l a t i o n . S u l c a t i o n a l s o has n o t t h e s t a b i l i t y n e c e s s a r y f o r use as a g e n e r i c character; i n t h e s t r o p h e o d o n t i d s a t l e a s t , i t seems t o be a v a r i a b l e product o f g e r o n t o m o r p h o s i s . For instance, a p o p u l a t i o n of L . r o c k f o r d e n s i s w i l l show v a r i a t i o n from a n o n s u l c a t e form t o i n d i v i d u a l s w i t h a g r e a t e r s u l c a t i o n t h a n i s p r e s e n t i n some o f t h e L . camerata f o r m s . We have a l r e a d y seen t h a t t h e m e d i a n l y f o l d e d p s e u d o d e l t i d i u m i s a s t a g e o f development i m m e d i a t e l y p r e c e d i n g the smooth p s e u d o d e l t i d i u m , and t h i s i s b o r e n out b y t h e f a c t t h a t l o w - c o n v e x i t y n o n s u l c a t e forms found i n t h e S l y Gap f o r m a t i o n ( i . e . N e r v o s t r o p h i a s i n t h e r e s t r i c t e d sense) have a smooth p s e u d o d e l t i d i u m . I f we a c c e p t S t a i n b r o o k ' s d e f i n i t i o n o f N e r v o s t r o p h i a , t h e s e S l y Gap s h e l l s c o n s t i t u t e a new genus, and t h e r e would be f o u r general  56. erected t o cover a c l o s e l y r e l a t e d s t o c k . I n ray e s t i m a t i o n , i t i s p r e f e r a b l e t o r e l e g a t e a l l t h e s e forms t o N e r v o s t r o p h i a and r e g a r d t h e group as a main g e n e r i c s t o c k p u r s u i n g a n o r m a l c o u r s e o f development i n r e s p e c t o f the p r o d u c t i o n o f a smooth p s e u d o d e l t i d i u m and, i n i t s gerontomorphic s t a g e s , g i v i n g r i s e t o two s u b s i d i a r y d i v e r g e n c e s , a s u l c a t e s p e c i e s group and a h i g h - c o n v e x i t y s p e c i e s g r o u p . Genotype:  Stropheodonta n e r v o s a H a l l .  57. Genus SCHUCHERTELLA  Stainbrook (1943), Jour. Paleontology, Volume 17, No. 1., p. Ul. "Shells small to large, variable i n shape, biconvex, planoconvex, or resupinate, broader than long, with the hinge line less than the greatest width. Pedicle valve with moderately.high umbo and beak, which in some species may be twisted. Palintrope variable in height, divided by a strongly convex deltidium, which completely covers the delthyrium and may be concave at the base; each half i s divided into two areas by a line extending from the beak to the hinge line halfway to the extremities. The areas of the palintrope on either side of the deltidium are vertically and horizontally striated. The deltidium and the outer portions of the palintrope are only horizontally marked. Internally the hinge teeth are small, extend but l i t t l e beyond the hingeline, and are unsupported below by lamellae; only the edges of the hinge plate are thickened. Muscle areas small, indistingly impressed on the floor of the valve, and separated by a faint median ridge. The remainder of the interior i s quite smooth except near the lateral and anterior margins, where the costae are strongly expressed in reverse. Brachial valve variable, convex, f l a t to slightly concave. Palintrope low but distinct, divided by a low chilidium, which embraces the c ardinal process; each half of the palintrope i s divided into regions as in the opposite valve. Internally the cardinal process i s short, b i f i d , with each arm excavated a l i t t l e on i t s posterior extremity. From the base of the process on either side a ridge diverges for a distance of one or two millimeters laterally and anteriorly; distally these ridges are expanded a l i t t l e and posteriorly partially enclose a deep dental socket. Muscle area flabellate, usually not extending to the midlength; scars separated by a distinct median ridge, which i s broadly rounded along the summit. The remainder of the v alve i s generally smooth or marked by obscure ridges and faint papillae. Near the lateral and anterior margins the valve i s strongly cost ate. In neanic individuals the entire interior with the exception of the muscle scars may be cost ate. The above diagnosis i s based on Schuchertella lens (White), with Schuchertella prava (Hall) and Schuchertella iowensis (Stainbrook) as examples. Schuchertella was founded by Girty (1904) on Streptorhynchus lens White from the .Louisiana limestone of Missouri. The characters of the genus were summed up by Weller (1914) who mentioned the biconvex ity of the shell and the absence of dental lamellae as outstanding. These two characters he stated "as far as has been observed are always associated." The genus as thus defined i s closely related to Schellwienella, which differs i n possessing dental lamellae and a resupinate shell. Genotype: S. lens White  118  UPPER  a  I  ixroaiu  BPUOHIOMM  •  anhuahmr t e l l e chgmun,gan.l. (Conrad) l l l u a t ratloae after kindle. " P o r t i o n of a ventral valve showing atrlaa nnd distorted beak. 8, Dorsal valve, (both 13) 3, area Of wentrsl valve. • O H U O R X R T I L U CHtMUsOENSIS  Bchuchertolla cboaungonst a Conrad (Kindle)  KflwTT I. Seol. Burr. Bull. 391. pi. III.  P. 16. The variable character of thia apeciea l a at 11 known. Thia l a eepecially aanlfeet la the atrlaa, which are of threw general types. In one of theoo the etrlae are aubsqual, fine, aad thrssdllks, aa In the warlet* figured by d i r t y . In another variety fine aad o'oarao atrlaa alternate aore or loaa regularly. In a third variety, which baa bean obeerved at only one l o c a l i t y , the etrlae are arranged in faeciclee of three or four fine atrlaa as par ate u by much coarser ones.  41M11  • rYdt un.Viit.IAt. Mh'UHOMlM  Junction of ths two valvea. Baas wnittsae projecting slightly ever the sardlnal or00. Delthyrium covered by s eesjvex, tr—suroolr ridged, end striated deltidium. Internally both dental lsasllss and aedlaa septum absent. Braehial vslvs vary gently sad ssswasuslly convex both longitudinally and tranevarasly. Cardinal area very na  3CHXHBITSI1A CIRTTI (Shiner 12*6) Shimer, H.W. Osoc. Ser. Can. P u l l . U2, p.Jl». 3Ch"XHgTiaU GIRTI! Deecrl.tloni Shell n o l l e biconvex, wider than 7tOrg^vTTn"hlnge-lLne epp»reutlv shrrtor t . n the greatest width of the obeli. Selthyrlur. s l i g h t l y higher than wile. The dlnens^ons of i acr^whst lnperfest shell are. length of jjed'eV valvals of brschlal valve 16 m% treatest breadth apparently near the midline of the shell; 2!; mu j thickness 9.5 »U langth cf hinge lins IS lsngth and heeal breadth cf lelthyriu. '..r and u.5 "at. A amaller pedicle vslv* w-.s 13 A . lcn^ and 17 mm, vide. v  i  Pedicle valve arched fron hcl- tc front, d i s t i n c t l y ao lr. ths umbonal rot'on, very slightly aa ar almost flat beyond. Transversely ths vslvs Is most eomvex in ths umbonal region, from ths highest point of salon ths voire dsoondo in almost straight 11ns to ths cardinal margin. Anteriorly ths waive le slightly flattened medially. Cardinal area high, tieasvsrsaly end vsntioelly atrlaa, straight below, arched above, tba lower part inclined posteriorly so rs to form an eagle of about 110 dagrwea with the plana of tha  Surface of both valvea marked by fine, ah ar ply elevated radial coetae, about II ts 16 of which occupy the space of 5 mm. j lnterspsssa wider than costss. These coatas may be nearly equal in height and breadth, may alternate in aiss, or each third or fifth coasts may be consllerehlv stronger than the intermediate ones. Five concentric growth .lr.es are faintly visible between the a trlae. Remarks.  A.parently Identical uith Ortho  Chrnmupgensla var. Glrtyi but differs in that the hinge line Is always snorter then the width of the shell below, whereas in ; QlrtT ths hinge lins may be the shall below. l.ocalltj or Horlscni Upper Devonian (Cursy) or Colorado, In the tlinneaaks region in ths Upper Devonian 'iberta. Ulegraas Pig. 1. Fedlcle visa of type specimen Fig. 2. side view of type apeelaan Pig. 3. cardinal view of type easel  59 IIViDA*a6I»  umh 1* VON las dHACniOPOUA aeeeureaente.-- Holotypa, a lata 41 a a . , length 3 b aa., tnlctnese 13.6 aa. Occurrence.--  aerriea 1940, Holotype,brachial viae, ellghtly r cauced. 8CHUCHIRTELLA  SEVADAIB8I8  •chiicttartallaBaTadaanala Merries (1940) Oeol. loc. A S S T . , Me. Pap. lo. 4b, p. 80, pi. 6, fig. 6. Daacrlptlon.This apocle* la on the whole a auch larger iora than Sccucncrtolla 6ague1 sad poeeeeee* coeraer radlel omaaantatloa ana batter developed concentric lncreaentel rldgee. Profile el ventral valve lletteoea in Iront oi uaboi no reveraal ol curvature. Tao well preeervea apeclaene ehow etralgbt anterior coaalaeurea. lo ladlvlduale oi thle iora ahoe conveiiiy of tbe ventral valve oeyona the uabonal region. Ditlere froa (J. dofprale (Hall) and froa f. chomungonala (Conrad) in lta generally coaraer ornaaentatlon. The cardinal area ol tbe nee fora appeara to be reletively loaer than that of J. lane White 'genotype cl Schuchertella) froa the Louleiana llaeetone of Ulaaourl. The fora froa Lone Mountain regaraea oy falcon (16b4, p. lib) as Bchuchertelle chcaungeaele var. perveree (Hall) probably repreeente »hle epeclet PfiAVA  DEVONIAN HHACIIiOPODA  SCHUCHERTEIX4  Brachial valve more convex than thepedicle, being arched along the nid-length cf the v a l v e . Beak small and does not project beyond the ca'dinal marglnj area l i n e a r .  SCHUCHERTELLA fftAVA Stainbrook Stainbrook, 19li5, Oaol. aoc. Aaar., ram. l u , p. 31*, p i . 2, figs. 19, 20. SCHUCHERTELLA ffiAVA Stainbrook PaacriPtloni Shell medium sized, unequally biconvex, s e m i - e l l p t i c e l in outline, with the cardinal extremities obtusely angular. Diaanaiona of the hypotypej length LU.O mm., width 20.( ram., thickness 5.0 mm. Pedicle valva s l i g h t l y convex, with maxiaua convexity in the umbonal region, thence the shell flattens to the anterior and l a t e r a l margins. Cardinal area 3 mm. in height, inclined US degrees posteriorly to the plana of the valve. The deltidium is strongly convex, and narked by sinuous growth lamellae.  'he surface of both valves marked by f i n e l y roun ied radiating costae which incr ase by division toward the antericr margin. The costae erecrossed by fine concentric growth lawellae which become apparent in the v-.terior portion cf the s h e l l . Diagram:  Dorsal view.  4  60. Genus STROPHEODONTA Hall n.  genus.  H a l l (1852), P a l . o f New Y o r k , V o l . I I , p . 63. " S h e l l w i t h g e n e r a l form and c h a r a c t e r s o f L e p t a e n a ( v i z . one v a l v e convex and t h e o t h e r c o n c a v e , t h e concave one f o l l o w i n g t h e same c u r v e , and n e a r l y p a r a l l e l t o t h e convex o n e ) ; c a r d i n a l area continuous, n e a r l y l i n e a r , m o s t l y occupied by the d o r s a l v a l v e s t r i a t e d t r a n s v e r s e l y ; foramen d e c i d e d l y c l o s e d ; v e n t r a l v a l v e w i t h h i n g e l i n e u n i n t e r r u p t e d ; margins o f hinge l i n e c r e n u l a t e d ; area s t r i a t e d v e r y s t r o n g l y i n t h e t r a n s v e r s e and more s l i g h t l y i n t h e l o n g i t u d i n a l d i r e c t i o n . M u s c u l a r i m p r e s s i o n s somewhat b i l a t e r a l . The c r e n u l a t e d h i n g e l i n e i s a v e r y s t r o n g d i s t i n c t i v e c h a r a c t e r s i n c e i n L e p t a e n a t h i s m a r g i n i s smooth. I n t r u e L e p t a e n a a l s o t h e a r e a i s s t r i a t e d o n l y l o n g i t u d i n a l l y ( t h a t i s i n t h e d i r e c t i o n of the hinge l i n e ) and t h e foreamen i s i n p a r t o c c u p i e d b y a p r o j e c t i o n o f t h e v e n t r a l v a l v e which f i l l s I t ; w h i l e i n S t r o p h e o d o n t a , t h e foreamen, i f i t e v e r e x i s t e d , i s e n t i r e l y c l o s e d b y growth o f t h e i o r s a l v a l v e and t h e h i n g e l i n e o f t h e v e n t r a l v a l v e i s s t r a i g h t and c o n t i n u o u s . The s t r i a e o f the s h e l l i n many s p e c i e s o f S t r o p h e o d o n t a differ from t h o s e o f L e p t a e n a and some o f t h e s p e c i e s a r e r e a d i l y d i s t i n g u i s h e d by t h i s c h a r a c t e r a l o n e . " Genotype:  L e p t a e n a demissa (Conrad)  Conrad (18U2) d e s c r i p t i o n o f Stropheomena d e m i s s a , J o u r n a l Academy N a t u r a l S c i e n c e s , P h i l a d e l p h i a , V o l . V I I I , p . 25 b , p i . 1U, f i g . I i ; . i s n o t i n the L i b r a r y of the U n i v e r s i t y o f B r i t i s h Columbia. D e s c r i b e d b y W i l l i a m s (1953), G e o l . S o c . Am. Mem. 56. "Exteriors Outline semicircular to elongately semi-oval, mucronate, c o n c a v o - c o n v e x w i t h a h i g h v a r i a b i l i t y i n s t r e n g t h o f c u r v a t u r e . V e n t r a l i n t e r a r e a a p s a c l i n e i n e a r l y members, o r t h o c l i n e i n l a t e f o r m s , and dorsal interarea correspondingly anacline to hypercline; delthyrium p r o g r e s s i v e l y c l o s e d b y p s e u d o d e l t i d i u m e v e n u t a l l y e n t i r e and smooth, c h i l i d i u m i n i t i a l l y s t r o n g l y convex p r o g r e s s i v e l y degenerate u n t i l i t i s lost. U n e q u a l l y p a r v i c o s t e l l a t e ; i n l a t e r forms a s e c o n d a r y b u t p r o g r e s s i v e l y dominant c o s t a t i o n i s s u p e r i m p o s e d . Pseudopunctae i n i t i a l l y i n an open r a d i a l p a t t e r n , i n l a t e forms more c l o s e l y s p a c e d . Ventral Interior: Hinge l i n e becoming p r o g r e s s i v e l y d e n t i c u l a t e from i n i t i a l s t a g e s o f k t o 6, s u p p o r t e d b y a p a i r o f d i v e r g e n t d e n t a l p l a t e s s u b s e q u e n t l y l o s t , t o an almost e n t i r e l y d e n t i c u l a t e s t a g e . Process p i t s p r o g r e s s i v e l y deeper, s t r o n g l y excavate i n l a t e r forms. V e n t r a l process p r o l o n g e d a n t e r i o r l y i n t o a v a r i a b l y d e v e l o p e d median r i d g e , i n i t i a l l y o b s c u r e , p r o g r e s s i v e l y s t r o n g e r , l o s i n g t h e c o n c a v i t y on t h e p o s t e r i o r f a c e  61 and f i n a l l y d e v e l o p i n g a p a i r o f s t r o n g p s e u d o t e e t h . D i d u c t o r muscle scar e l o n g a t e l y s u b c i r c u l a r , a n t e r o - l a t e r a l t o the l a n c e o l a t e adductor s c a r , i n i t i a l l y v e r y f a i n t l y i m p r e s s e d but p r o g r e s s i v e l y more s t r o n g l y s o . No h i g h - b o u n d i n g muscle r i d g e s . Dorsal Interior: C a r d i n a l process lobes i n i t i a l l y p l a t e - l i k e , c o n j u n c t , w i t h attachment f a c e s d i r e c t e d p o s t e r o - v e n t r a l l y becoming p r o g r e s s i v e l y s t o u t e r and more d i s j u n c t u n t i l attachment f a c e s a r e f i n a l l y d i r e c t e d p o s t e r i o r l y t o p o s t e r o - d o r s a l l y . Socket p l a t e s i n i t i a l l y s t r o n g , d i v e r g e n t , m i g r a t i n g towards h i n g e l i n e and e v e n t u a l l y p a r a l l e l w i t h i t t h e n a b b r e v i a t e d a f t e r l o s s o f d e n t a l p l a t e s i n the v e n t r a l v a l v e and f i n a l l y o b s o l e s c e n t . A d d u c t o r muscle s c a r , s u b c i r c u l a r , d i v i d e d b y a median r i d g e and b y 2 v a r i a b l y d e v e l o p e d l a t e r a l r i d g e s . I n i t i a l l y f a i n t l y i m p r e s s e d , i n l a t e r forms s c a r s , f o l i a c e o u s , i m p r e s s e d on b u i l t - u p a r e a s o f secondary d e p o s i t w h i c h b u r i e s p o s t e r i o r p a r t o f median r i d g e and o f t e n e x t e n d s f o r w a r d on e i t h e r s i d e o f t h e v i s i b l e p a r t o f t h e septum as two b r o a d c a l l o s i t i e s . " Genotype: Range:  L e p t a e n a demissa Conrad Upper O r d o v i c i a n t o the end o f Upper D e v o n i a n .  008TATA  UPPxn DEVONIAN BHAChIOPODA  8TR0PHE0DOJ.TA  t a d , a s k i n g e r i g h t a n g l e w i t h the p l a n e o f the v a l v e , and about h a l f aa h i g h or mora than h a l f aa h i g h as the o p p o s i t e a r e a . I n t e r n a l l y tba b i f i d c a r d i n a l p r o c e a s l a s h o r t ana s t o u t , tbo apophyses a r e c l o s e t o g e t h e r and a l l g h t l y d i v ergent, l l u a c l e a r e a e l e v a t e d , the adductor a c a r a o u t l i n e d oy narrow rounded r i d g e a , and the a a d l a n r i d g e not e t r o n g l y developed but extending *l{TFE« <f9r f fPf 1 '** °»» P - l l c l . vie. ol beyond the c e n t r e o f the v a l v e . Hear and p a r a • t y p i e e l s p e c i m e n . 8 , 3 , P e a i c l e end b r a c h l l e l t o t h e a n t e r i o r ana l a t e r a l a a r g l n a l a a v l e e e of • hypo t y p e . low rounded r i d g e , beyond which the s u r f a c e o f the v a l v e i s a c r u p t l y a e i l e c t e d t o the x a r g i n a . 8TROPHE0DOHTA C08TATA S u r f a c e o l p e d i c l e v a l v e a a r x e d cy a o d e r a t a l y s t r o n g rounded t o a n g u l a r c o a t e e , which I n c r e a s e S t r o p h e o d o n t a o p e t i t e o w n S t a i n b r o o k 1938 by i n t e r c a l a t i o n a c c o a p l i e r . f i three t l a e e f r o a J o u r , of P a l e o n t o l o g y , v o l . 18, p . 844 beat to f r o n t . Coetae o i b r a c h i a l v a l v e c o r e p i . 33, f l g e . 38-81. rounded, w i d e r , ana l n c r e a a e by d i v i s i o n . The D e s c r i p t i o n . - - I b e l l e a e l l , concavocoetae on both v a l v e e vary i n e l s e , tha l o n g e r c o n v e x , o l d e r t h e n l o n g , oubquadr a n g u l a r onee b e i n g broader ana xore c r o s i n e n t . The i n i a o u t l i n e , a n t e r o l a t e r a l a a r g l n a roundt e i c o e t a l epacee a r e aa a i d e c r e i d e r than ::.e ad a n d c a r d i n a l a n g l e , a u r i c u l a t e , g r e a t e s t coetae and i n x . s t e p e c i x e n e a r e rounded at the a l d t h a l o n g tba h i n g e l i n o or i n f r o n t o f bottoa. S e v e r a l prominent growth l i r . e s and it. Dlaenelona of e e v e r s l hypotypee. length nuaeroua l i n e c o n c e n t r i c a t r l a a c r o e a the cos18.8 a a . , lb.8 a a , , a l d t h , 16.6 a a . , l b . 7 a a . , t s * . Worn v a l v e s snow '.he x . n - t e l y p u n c t a t e c o n v e x i t y o f tbo p e d i c l e v a l v e , 6.t> aa., and a h e l l substance and nuaeroue l i n e l o n g i t u d i n a l 6 aa. r a d i a t i n g e t r l a e on tne c o e t a e . P e d i c l e v t l v e convex, g r e a t e u t c o n v e x i t y a t 8. c o a t a t a d l f f e r a f r o a 8. p l i c a t e i n te.r.g tbe a l d p o l n t , t b a s u r f a c e c u r v i n g thence t o t h e e a a l l a r , l e a s convex, and In p o s s e s e l n g a l e a a f r o n t and l a t e r a l a a r g l n a and l e a a r a p i d l y e t r o n g l y d e v e l o p e d unbonal r e g i o n . to tha h i n g e l i n e , g e n t l y f l a t t e n e d or dep r e o e e d In f r o n t o f the uabo and depreeaed In i r o n t o f the a n g l e s . Beak a a a l l , p o i n t e d , a l l g h t l y I n c u r v e d , c s r u l n a l a r e a t l a t or g e n t l y concave, n l g n e e t beneath tne beak nnd a a l n t a l n l n g the aaae h e i g h t n e e r l y t o the e x t r e a l t l e a , v e r t i c a l l y s t i l s t e d , and i n c l i n e d p o e t e r l o r l y at an angle o l about 45° t o tnt p l a n a o f the v a l v e . I n t e r i o r unknown. B r a c h i a l v a l v e concave, f l a t i n unbonal r e g i o n and c u r v i n g e t r o n g l y upward t o the l a t t i a l and anterior aarglna. Area f l a t , v e r t i c a l l y a t r l a a  >t  n  62 DORiATA  UPPER DEVONIAN BRAOHIOPODA  «  S  pilflBfllBflflftU flflrjula. Sttinbrooic, 1,8, pedtola and breohlal vlewe of a paratyp*. 3,4,5, Poatarlor, pedicle and brachial viewa of tha holotypa,  8TR0PHE0DONTA  Padlcla valva atrongly coovex, tha eurface curving froa the central point of the valve a l t o equal r a p i d i t y to the aargina, e l l g h t l y aurlculate at tha anglee; uabo e l i t t l e convex; beaJc email and projecting e ehort aletanca beyond tbe hinge l i n e ; area H a t , of nearly the aaae height throughout, ana altuatea in the plane of the valve. Interior unnnown. Brachial vulve deeply ana evenly concave, but flattened in the uabonal region; area low and nearly at right angle* to that of the pedicle v l v e . Coetae of both valvee nuaeroue, r a d i a t i n g , coaree, rounded to angular at the euaaita, and Increasing by l u b r i c a t i o n on the pedicle valve and by alvlelon on the b r a c h i a l . Orowth line a not uncoaaon and In many epeclaene conspicuous near the anterior aargln. Specimens at hana are noticeably lacxlr.g i n coatae, due in generel to aaatherlng but in eoae inatancea due to wear oetore entoaoaent. The • b e l l e are ueually reddieh or p u r p l i s h . The aedlua e l i e , the proportionately greater convexi t y , and the thicxneee of the ehelle d l a t l n guleh tma apeciee i r o a 3. h a l l l , froa 8. cedarenala. and 8. U t t l o t o n e n o l a .  8TK0PHE0D0NTA 00R8ATA •trophaodonta doreata italnbronic. Jour, of Paleontology, 1838, v o l . 18, p. ab*.  alia,  Deeorlptlon.—Shall of aedlua alder than long, with the greateat width anterior to tha l i n e , aubquadrat* in outline, e l l g h t l y rounded at tb* anglee and broadly rounded at tha f r o n t . MJoaaureaenta of the holotype and of two paratypee: length, 87.5 a a . , 30.1 a a . , and 38.6 a a . ; a l d t h , 31.5 a a . , 37.8 a a . , and 37.8 a a . | oonvexlty of the pedicle valve, 11.6 a a . , 13.3 and 14.6 aa.  bing*  aa,  HALL I  UPPIH DEVONIAN BKAOHIOPODA  STROPS EODOIT A  Brachial valva ahallowly concave, flattened in the uabonal region, eurface curving upward evenly to anterior and l a t e r a l aargina and aora abruptly to cardinal aargln. Cardinal area 1/8 aa high aa that of oppoaite valve, f l a t , v e r t i c a l l y e t r l a t e d , and at r i g h t anglee to the plane of the valve. Internally the apophyaee of the cardinal proceas are u.-.ort, etout, grooved at the e x t r e a i t l e e , widely divergent, and extended a l i t t l e beyond the hinge l i n e . Tne auecle scars are variably aevelopea in d i f f e r Itropbeodonta h a l l l Cleland. 1, 3, Pedicle vleaa ent epeclmene, weax In t h i n , atrong In old or Posterior adductor acsxe are or two holotypee, M.A.8. 778, f r o a Buffalo, Iowa thlcx s h e l l s . borderea l & t e r a l l y ana a n t e r i o r l y by low nar3, Internal vies of a brachial valve, S . U . I . row rlagea, anicn, originating in lront of and 6-367, froa Llnwood, Iowa. l a t e r a l to cardinal proceaa, extend forwaxa for some ulstar.ee and, turning inaara ana bacxSTROPHfODOHTA HALLI ward, boraer the anterior scars a ehort way. trophaodonta h a l l l Cleland, Jour, of Paleonto- Narrow median aeptua risee between front xarglna of the anterior aaductora, Increases In ogy 1B3B, voirTZT P.8*3, p i . 35, flge.1-3 height towara front, enae abruptly ehortly beDeeorlptlon.—Shell large, wiaer than long, yond aldale oi valve. Nuxeroua papillae are tranaveraely aubell l p t i c a l with rounded anecatterea over remainder of valve cut are t e r o l a t e r a l aargina, extended cardinal anglee, aora abundant and pronounced near muacle scare. wldeat along tbe hinge l i n e . Several mm. irom the l a t e r a l and anterior marMeaeurementa.—Hypotype, length, 89.3 aa., glne the floor ie elevated into a broad, low width, 40.9 aa, thicxneee, 9.1 aa. Pedicle valve convex, highest in the central ridge marxea by numerous tranaveree ainuaee. part, aurfaoe eloping gently away from the a i d point in a l l d i r e c t i o n , more r a p i d l y on approchlng anterior and l a t e r a l aargina, depreesed anterior to the cardinal e x t r e a i t l e e and elevated In the uabonal region. Beax email, p r o j e c t ing a l i t t l e beyond the hinge l i n e , . a r e a f l a t , v e r t i c a l l y etrlated, often attalna height of aora than 8 a a . , gradually decreaeing in height toward the extreaitlee, i n c l i n e d poeterlorly and approaching the plana of the valve. Intern a l l y the broadly f l a b e l l l l o r a auecle area extende anteriorly beyond the midlength, more than half aa wide aa the valva. Area aarxed by low angular radiating rldgee and le d i e t l n c t along poeterolateral border and l n d l e t i n c t l y aet off froa reet of reive toward front.  ?  63 UPPIH DEVON I All BRACHIOPODA  PLICATA  f  trophopdonta p l i c a t e B a l l . 1,2, P e d i c l e and r a c h l a l vlewa o f a h o l o t y p * . 3, B r a c h i a l v i a e of a n o t h e r . 4,5, L a t e r a l and p e d i c l e v l e a o o l a l a r g o epeolaen, f r o a H i d R i v e r , Johneon County,  Iooa.  8TH0PHE0D0NTA PLICA 1A Stropheodonta p l i c a t e H a l l , S t a l n b r o o t 193b, J o u r , o f P a l e o n t o l o g y , v o l . 18, p.246, pi.  33, f l g e .  1-5  D e s c r i p t i o n — She^l about medium s i t e , mature epecioone e t r o n g l y concavo-convex, about aa l o n g aa wide, eubquadrate i n o u t l i n e w i t h a l l g h t l y a u r l c u l a t e c a r d i n a l anglee and rounded a n t e r o l a t e r a l a a r g l n a , e l d e s t near the midl e n g t h , and w i t n tne hinge l i n e g e n e r a l l y l e a a than tbe g r e a t a a t w i d t h , ksasureiaente o i two hypotypee, l e n g t h , 19.1 aa. and 19.1 oa.,width, 20.9 a a . and 16.7 am., t h l c x n e e e , 9.4 am. and  Si ROPHEODOBTA  Beat s m a l l , D l u n t , ana extended oeyond tne c a r d i n a l a a r g l n . Area h i g h a a t beneath the beak and d e c r e a s i n g I n h e i g h t r a p i d l y toward t h a e x t r e o l t l e e , a l l g h t l y concave, and e l t u a t e d i n the plane o f the v a l v e . An Incomplete v a l v e ahowe the l l a b e l l a t e a u a c l e e c e r e ana the c r e n u l s t e hinge l i n e c h a r a c t e r i s t i c o f the genue. B r a c h i a l v a l v e g e n t l y t o deeply concave, t b e s u r f a c e depreeaed In t h e u a t o n a l r e g i o n ana a l i t t l e e l e v a t e d i t the a n g l e e , beak l n d i e t i n gulehable. Area l o a , o f n e a r l y the same h e i g h t throughout, and a t r i g h t a n g l e e t o tbe o p p o s i t e area. S u r f a c e o f both v a l v e a a a r x e d by r.uaeroue e t o u t a n g u l a r c o u t a e , which are s e p a r a t e d by I n t e r c o s t a l epacee n e a r l y aa wide aa the coetae. Increase i s oy j i v i s i r. a c c o a p l l a h e a s e v e r a l t i a e a , tne coa-.ae celr.g l a r g e r near the t e a t s ana s m a l l e r r.ear the f r o n t a a r g l a . The c o a t e e , v a r i a b l e In e l x e and l e n g t h , a r e arranged i n groupe g i v i n g tnem a f a a c l c u l a t e anpearance c h a r a c t e r i s t i c o f t h i s f o r a . Stropheodonta p l i c a t e l e d l a t l n g u l a h e a : r o a Stropheodonta c o t t a t a oy l a r g e r e i z e , oy g r e a t er c o n v e x i t y o f the c e d l c l e v . l v s , and cy the ouch c o a r a e r coetae a r r a n g e d I n g r o u p s .  P e d i c l e v a l v e e t r o n g l y convex, arched i r o n beak t o f r o n t and more e t r o n g l y over the umbo, b l g b e a t a t the m i d p o i n t , l r o a which the s u r t e c e a l o p e e r a p i d l y t o tha a n t e r i o r ana l a t e r a l a a r g l n a and aore r a p i d l y on each a i d e o f the uabo t o the hinge l i n e , a l i t t l e f l a t t e n e d a t tbe c a r d i n a l a n g l e s . Uabo s t r o n g l y d e v e l oped ana p r o j e c t i n g beyona the ningo l i n e . SUB DERI 88A  UPPER DEVONIAN BKACHIOPODA  BTHOPHEODOITA  the umbonal r e g i o n and depreeaed toward the c a r d i n a l e x t r e o l t l e e ao aa t o g i v e then an a u r l c u l a t e appearance| beat a a a l l , s c a r c e l y p r o j e c t i n g ; c a r d i n a l a r e a low and d a c r e a a i n g b u t l i t t l e i n h e i g h t u n t i l near t b e e x t r s a l t i e a , H a t , v e r t i c a l l y a t r l a t a d , and p o s t e r i o r l y i n c l i n e d a l i t t l e t o the plane o f t h e v a l v e . I n t e r i o r n o t known. B r a c h i a l v a l v e moderately concave, the a u r l a c e f l a t t e n e d c e n t r a l l y but c u r v i n g upward s t r o n g l y t o the l a t e r a l and f r o n t aarglna,' area H a t , n e a r l y h a l f a s h i g h as the o p p o s i t e a r e a ana making a r i g h t angle w i t h I t . The i n t e r nal c h a r a c t e r s are s i m i l a r t o those o i o t h e r members o l the genua. S u r l a c a o f b o t h v a l v e s marxea oy nuaeroua a n g u l a r f a i r l y e t r o n g c o s t a e , which I n c r e a s e by Stronbnodonts aubdealaaa H a l l ( i l l u s t r a t i o n s i n t e r c a l a t i o n ana b i i u r c & t l o n . They are aore a f t e r S t a i n b r o o k , 1938 p i . 35, f l g a . 14, 15, rugose ana c l o s e r togetner In tne p o s t e r i o r p a r t 17, 1 8 . ) 1, I n t e r n a l view o f a b r a c h i a l v a l v e , of the v a l v e s ana s n t e i i o r i y are e v e n l y s p a c e d , 3 , 3, 4, P e d i c l e vlewe, o f tnree hypotypee. about two occupying the space o l a m i l . l a e t e r at the i r o n t margin. The I n t e r c o s t a l spacea 8TR0PHE0D0HTA SUB DEMI 83 A are as wlae as tne c o s t a e or wider i n d , l i x e them a r e a a r t e a cy numerous puncatae where Stropheodonta a u b d e a l a a a H a l l ( d e s c r i p t i o n worn and by l i n e l o n g i t u d i n a l r a d i a t i n g e t r l a e . a f t e r Stainbrook, Jour, o of P a l e o n t o l o g y , 1938, 8. eubdemlasa d i f f e r s from S. h a l l l i n the p. 8 4 6 J . g r e a t e r w i d t h I n p r o p o r t i o n t o l e n g t h and i n the a u r l c u l a t e e x t e n t l o n o f the c a r d i n a l e x t D e s c r i p t i o n . — S h e l l medium to l a r g e , wider than r e o l t l e e . l o n g , w i t h tbe g r e a t e s t w i d t h a l o n g the hinge Una, tranaveraely aubeeoi-ellptioal i n outline w i t h the c a r d i n a l a n g l e e extended and a u r l c u l a t e and the a n t e r o l a t e r a l margins rounded. Dloena l o n a o i a hypo type, a a e d l u n - s i a e d , n e a r l y c o o p l e t e ehell.' l e n g t h , 19.8 sua.; w i d t h , 31.3 aa.; c o n v e x i t y o f p e d i c l e v a l v e , 7.5 am. P w d i c l o v a l v e moderately convex, a t t a i n i n g i t s h l g h e a t p o i n t i n the c e n t e r o i the v a l v e , whence the s u r f a c e s l o p e s l a t e r a l l y and a n t e r i o r l y w i t h moderate r a p i d i t y ; g e n t l y convex i n  64 •ATA  UPPER DEVONIAN BRAOHIOPODA  STROPHEODONTA  of t h e c a r d i n a l a n g l e e ; umbo l a r g e end c o n aplcuoue, p r o j e c t i n g beyond t h e hinge l i n e ; beak a a a l l , i n c u r v i n g , and p r o j e c t i n g a l i t t l e c a r d i n a l a r e a h i g h e a t beneath the oeak, dec r e a s i n g i n h e i g h t toward the e x t r e a d t l e e , g e n t l y c u r v e d , and s i t u a t e d I n tne plane o f the v a l v e . B r a c h i a l v a l v e s t r o n g l y concave, the uabonal r e g i o n f l a t t e n e d or depreesed, deepeet I n the c e n t r a l p a r t , t h e e u r f a c e c u r v i n g upward r a p i d l y near the a a r g i n a , f l a t t e n e u toward the c a r d i n a l a n g l e e so as t o f o r a s m a l l t r i a n g u l a r areas e l e v a t e a above tne c e n t r a l p a r t of t h e v a l v e ; beak l n d l a t i n g u l s h a b l e ; a r e a low, f l a t and a t r i g h t anglee t o the plane o f t h e v a l v e . Surface o f b o t h v a l v e e broxen by nuaeroue odonta uabonata Stainbrook• 1,Pedicle coarse a n g u l a r r a d i a t i n g coatee o f v a r i a b l e Pedlole and l a t e r a l vlewe of a paratypa, 8 . U . I . a l i a , which l n c r e a a e by i m p l a n t a t i o n . The I n t e r c o s t a l spaces are aa wide or wider than 6-350; both froa Solon, Iowa. 8,5, Pedicle the c o e t a a . S h e l l substance when worn i e puncTlewe of two paratypee, M. A. 8. 87; both froa t a t e and a t r l a t e . Occasional groath U s e e U n d e r ' e boathouae, North of Iowa City, Iowa. croaa the coetae. Occurrence.--Cedar V a l l e y l l m e a t o n e . The STROPHEODONTA URBONATA type s p e c i a e n e a r e f r o a the b e l l u l a xone (Regl e t o c r i n u e bede o f C a l v i n ) ana were c o l l e c t e d •trophaodonta Uabonata Stainbrook. 1938, Jour, i n Johnson County between Solon and the Iowa of Paleontology, v o l . 18, p.858, p i . 33, U g a , R i v e r . Other examples have been found at U n 6-9, 19. der'a boathouae, n o r t h of Iowa C i t y , a t Deeorlptlon.—Shell leaa than aedlua alee; B u f f a l o , and a t Brandon, Iowa. highly concavo-convex; eubquadrate In outline T y p e s . — H o l o t y n e , S.U.I. 6-350A; P a r a with angular cardinal e x t r e a i t l e e and rounded anterolateral aargina, which meet in a gradual typee, 6-2bOB and C, and U. A. S. 475, 486, and 87. curve at the front; a. l i t t l e wider than long, and widest In front of the hinge l i n e . Dlaanaiona of the holotype and of a paratype; length, SO.Saa. and 88,4mm.; width, 81.7aa. and 88aa. (Incomplete); convexity of the pedlole valve, 16.6 aa. and 10.8mm. Pedlole valve etrongly convex, the point of graateat convexity poeterior to the midlength, whence the eurface elopea rapidly to th* anterior aargln and more r a p i d l y to the l a t e r a l aargina, dapreeeed a l i t t l e In front  PAHVA  UPPEH DEVONIAN bKACH10P0UA  STROPHEODONTA  S u r f a c e o f b o t h v a l v e e broken by nuaeroue f i n e a n g u l a r c o a t e e , which a r e r e g u l a r i n appearance. Coetaa l n c r e a a i n g by d l v l a l o n and i n t e r c a l a t i o n on the p e d i c l e v a l v e and by d l v l a l o n on the b r a c h i a l . Three t o f o u r i n the epece o f a a a . a t the f r o n t a a r g l n ef a a e d i u a - a i i e d a p e c i a e n . Croaoeo by f e w nta parva Owen ( l l l u e t r a t l o n a after e t r o n g l i n e a o f growth and nuaeroue l i n e 7 1938, p i . 33, l l g e . 80-87, 38-33.) c o n c e n t r i c e t r l a e . In worn s p e c i a e n e the e h e l l eubetance i e l o n g i t u d i n a l l y e t r l a t e d 8,3, Pedicle and brachial vlewe of a aaall and m i n u t e l y p u n c t a t e . hypotype, 1, 4, 5, Pedicle vlewe of t h r e e Owen's typee o f t b i e e p e c l e e have n o t hypatypee. been r e c o v e r e d , but h l a b r i e f d e e c r i p t l o n , STROPHEODONTA PAHVA h l a meaeureaents, and h i e l l l u e t r e t i o n i n d i c a t e t h a t he had a t hand bpeclmene a e a c r l o e a . ropheodonta parva Owen (tnle description However, Owen notee f r o a 80 t o 30 coatae tar Stainbrook, (1938), Jour. Paleontology, ahereaa eome o f our specimens ahow a e a r l y Vol. 18, p. 845.) t w i c e t h a t aany. The s m a l l s i x e , the nuaeroue f i n e c o a t e e , ana the c h a r a c t e r i s t i c D e e o r l p t l o n . — S h e l l a e l l c e t e , wlaer then shape d l a t i n g u l e h 8. p a r v a f r o a o t n e r Devonlong, depressed concavo-convex, auorectanguian epeclee. lar o u t l i n e , a n g l e s a l i t t l e a u r l c u l a t e , l a Occurrence.-t e r a l a a r g i n a a t r a l g h t and p a r a l l e l f o r moat part. Dlaenalone o f 8 hypotypea: l e n g t h , 15.4 a a . , 18.1 a a . ; w i d t h , 19 ma., 16 mm.; t h i c x neee, 5.6 aa., 3.9 am. Pedicle higheat p o e t e r i o r t o m i d l e n g t h , s u r f a c e e l o p i n g thence t o l a t e r a l ana a n t e r ior aargina and aore a t r o n g l y on each aide o f umbo t o hinge l i n e . Area low, h i g h e s t beneeth beak (about 1 a a . ) , f l a t , v e r t i c a l l y s t r i a t e a , and a l t u a t e d i n plane o f v a l v e . Brachial valve a h a l l o w l y concave, f l a t t e n ed c e n t r a l l y and g e n t l y depreeeed i n the uabonal region; area f l a t , n e a r l y aa wide aa t h a t of oppoelte velve and f o r a l n g an obtuse angle with i t . C a r d i n a l procaee s n o r t , a u e c l e ecere f a i n t l y l a p r e e e e d , end low median aeptua extende a ehort way beyond the a i d l e n g t h .  S  /  65.  Genus STROPHONEILA Hall 1879 emended. Williams (1953), Geol. Soc. of Am. Memoir 56, p. U7. "Exterior? Outline elongately semi-oval, mucronate, resupinate with a varying degree of curvature of geniculation. Ventral interarea wide, apsacline, dorsal Interarea narrow anacline, delthyrium progressively closed by pseudodeltidium but never attaining the entire stage, chilidium i n i t i a l l y highly arched, massive, becoming obsolescent but never absent. Basic ornamentation finely parvicostellate with widely spaced primaries, in some later forms shell ornamented by secondary costellae, often faintly rugate especially postero-laterally. Pseudopunctae open to closely radial in disposition. Ventral Interior: Hinge line progressively denticulate from a few denticles on either side of umbo to about half the length of hinge l i n e . Early forms with widely divergent dental plates, lost by fusion in later members of the astock. Process pits i n i t i a l l y faint, progressively deeperj ventral process progressively stouter to form a massive support to pseudodeltidium, prolonged anteriorly as a fine strong median ridge. Muscle scar i n i t i a l l y rather faintly impressed and subcircular, ultimately becoming quadrate and bounded laterally and anteriorly by low interrupted ridge with a "petaloid" appearance. Diductor scar flabellate lying lateral to a wide oval adductor scar. Dorsal Interior: Cardinal process lobes i n i t i a l l y long and plate-like, conjunct with postero-ventrally directed attachment faces, becoming massive and incipiently disjunct. Notothyrial platform i n i t i a l l y absent, in later forms consisting of a low, triangular deposit of secondary shell substance. Socket plates i n i t i a l l y long and widely divergent becoming short. Adductor muscle scar faint, subcircular, divided by a low median ridge and bounded by low indistinct ridges." Genotype:  Stropheodonta semifasciata Hall  Range: Lower Silurian (Gasworks Sandstone) to Middle Devonian (Hamilton).  70. S u p e r f a m i l y Chonetacea (Shrock and T w e n h o f e l , p . 3 2 7 ) . " F l a t t i s h s h e l l s w i t h concavo-convex p r o f i l e , p s e u d o - p u n c t a t e , and w i t h s p i n e s a l o n g p o s t e r i o r m a r g i n o f p e d i c l e v a l v e . Range:  Upper O r d o v i c i a n t o P e r m i a n .  Genera D e s c r i b e d : I. II.  Range:  Genus Choneta,s F i s c h e r Genus Chonopectus H a l l and W h i t f i e l d  Upper D e v o n i a n t o Lower M i s s i s s i p p i a n .  Reported!.occurrence o f t h i s s u p e r f a m i l y i n t h e l i t e r a t u r e r e v i e w e d i n Part I of t h i s t h e s i s . I . Genus Chonetds F i s c h e r .  8, ° , 1 0 , 1 2 , 2 1 , 2 2 , 2 6 , 3 1 , 3U, 35.  »C. deflecta Hall. C. l o g a n i H a l l .  18, 2 0 , 2 2 , 3 3 . 2.  C. s e t i g e r a K i n d l e . II.  21.  Genus Chonopectus H a l l and W h i t f i e l d . C . horaeus C r i c k m a y .  39.  71  Genus CHONETES Fischer n.  gen.  D e s c r i p t i o n b y F i s c h e r (1837) i n H a l l (1852) N a t . H i s t . N.T.,  Vol. II,  p.6U.  " T h i s genus has t h e same form as L e p t a e n a and i s d i s t i n g u i s h e d p r i n c i p a l l y b y a row o f t u b u l a r s p i r e s on t h e m a r g i n o f t h e d o r s a l v a l v e boardering the a r e a . "  D e s c r i p t i o n by Davidson  (1854)  i n B r i t i s h F o s s i l B r a c h i p o d a , p . 113*  " S h e l l i n e q u i v a l u e , compressed s e m i c i r c u l a r , w i t h a s t r a i g h t h i n g e l i n e , commonly as l o n g as the w i d t h o f t h e s h e l l , o r p r o l o n g e d i n t h e shape o f a u r i c u l a r e x p a n s i o n s , d e n t a l v a l v e convex depressed towards t h e c a r d i n a l edge, s o c k e t v a l v e always concave f o l l o w i n g t h e curves of the other; a r e a d i s t i n c t almost e q u a l i n b o t h v a l v e s or l a r g e r o r more produced i n the d e n t a l one, t h e uppermost edge o f t h e a r e a i n the l a r g e r v a l v e i s a c u t e and p r o v i d e d w i t h a row o f d e l i c a t e s p i n o s e h o l l o w t u b e s , v a r y i n g i n number i n d i f f e r e n t s p e c i e s and becoming g r a d u a l l y l o n g e r as t h e y r e c e d e from t h e e x t r e m i t y o f t h e beak, d i v e r g i n g o b l i q u e l y from t h e h i n g e l i n e ; f i s s u r e covered by a p s e u d o - d e l t i d i u m . I n t h e s o c k e t v a l v e t h e opening i s e n t i r e l y f i l l e d up b y a p r o j e c t i n g b i f i d or t r i f i d c a r d i n a l p r o c e s s ; s u r f a c e ornamented w i t h m i n u t e , l o n g i t u d i n a l , d i c h o t o m i s e d , or i n t e r c o l a t e d s t r i a e , r a r e l y l a r g e l y p l a i t e d , b u t t r a n s v e r s e l y marked b y c o n c e n t r i c l i n e s o f g r o w t h . I n t e r n a l l y t h e v a l v e s a r t i c u l a t e b y means o f t e e t h p l a c e d a t t h e s i d e s o f the f i s s u r e o f t h e d e n t a l v a l v e , and c o r r e s p o n d i n g s o c k e t s e x c a v a t e d on each s i d e o f t h e c a r d i n a l prominence a l r e a d y d e s c r i b e d . In the d e n t a l v a l v e , a small l o n g i t u d i n a l r i d g e d i v i d e s the muscular i m p r e s s i o n s i t u a t e d on e i t h e r s i d e , the c a r d i n a l muscles p r o b a b l y o c c u p i e d the g r e a t e s t space, t h e a d d u c t o r l y i n g on e i t h e r s i d e c l o s e t o the mesial r i d g e . In the socket v a l v e a b l u n t m e d i o - l o n g i t u d i n a l r i d g e d i v i d e s the q u a d r u p l e i m p r e s s i o n o f t h e adductor m u s c l e , w h i c h forms on e i t h e r s i d e two o v a l s c a r s between w h i c h ( i n some specimens) two s h o r t v a s c u l a r i m p r e s s i o n s p r o c e e d i n an outward o b l i q u e d i r e c t i o n . When t u r n i n g backwards and i m a r d s , t h e y t e r m i n a t e some d i s t a n c e from t h e i r origin. I n t e r i o r o f t h e v a l v e s i s c o v e r e d w i t h minute g r a n u l o u s a p e r i t i e s , arranged i n l o n g i t u d i n a l l i n e s ; a n i m a l unknown, p r o b a b l y f r e e or a t t a c h e d i n the young b y f i b r e s i s s u i n g from the f i s s u r e . " Discussion; D a v i d s o n f u r t h e r adds: " I n 1837 F i s c h e r de Waldheim (1) proposed t h e genus Chonetes b u t d i d n o t c h a r a c t e r i s e i t s u f f i c i e n t l y , and i t was o n l y a f t e r the p u b l i c a t i o n s of M . de K o n i n c k (2) and de V e r n u e i l (3) t h a t i t s v a l u e became k n o w n . " (1) F i s c h e r de Waldheim (1837) O r y c t o g r a p h i c du Gouv. de Moscow, p .  13h-  72. (2) M. de K o n i n c k (I8ii3) D e s c r i p t i o n des Anim. i ^ o s s . d u T e r r a i n . Carb. de B e l g i q u e . ( 3 ) De V e r n u e i l ( 1 8 4 5 ) R u s s i a and t h e U r a l M o u n t a i n s . V o l . ( i i ) .  Genotype: ( A c c o r d i n g  (ItShoaa)  t o Davidson) Chonetes S a r c i n u l a t a ( S c h l o t h ) .  UPP3P DEVONIAN RRACHIOPODA  CHO'.'STSS DSriJETA (Hall 1S67) J . Hall, Nat. Hist. Hew Tork. Vol. VII, p. 16. C'-ONETES DERBCTA (H»ll) Poser lotloni She?l semielliptical, length and width rour to five or eight to nine, hut rarely proportioi.aTly wider. Ventral valve extremely gibhoua, regularly arched to greatest elevation, being shout, the middle of the ler.gthj abruptly depressed towards the cardinal angles, which are flattened with extrea Itiee deflected toward the ventral side. The umbo is a little elevated at-ove the c ardinel margin, and the minute Apex (In perfect specimens? projects a little over the area. Dorsal valve deeply concave but not equalling the convexity of th» ventral valve. Area of the ventral valve nerrow with the exterior margin declining In e gentle curve to the extremities! the triangular foreamen is partially cloaed by a paeudo deltidium and the apature occupied hy the cardinal process of the opposite valve. Dorsal area more than half a. wide as the ventr-l, and marked In the middl. by e wide trlengulnr callosity.  v  VSTE3  Surface of the ventre'' valve marked / from twenty els to thlrtyfour sub angular or acmetliaes rounded striae, which are often irregularly lncreaeed by MfurcatIon or intercalation towards the mergl.i. In thoee with fewer striae they are sharper, more ahruptly elevated and only half »s wide se the Interepaceei while those with a larger nsmbef the striae end interspaces are equal hut ecrwttmes the striae heccnie fuller and r-iore revnded and the interspaces proportionally lass In width. The striae on the dorsal valve correspond to these on the ventral, but there is considerable space et the cardinal angle devoid of striae. Fine closely arranged concentric ctriae are visible or. the surface o f well preserved apecimens. Geological Type Lr.-alltyt  Hamilton grou; , New York.  Dia^ramai Pig. 1. Ventral ) *lg.'i.Dorsal ) views c f the ordinary fcrr. and sile. 'ig. 3. Profile j Fig. h. "entrsl ) fig. .">. Prrfile ) views o f a specimen referred to e Fig. 6. Dorsal ) c. gi^>-oea.  75 Genus CHONOPECTUS. n . gen. I n H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , 1892, V o l . V I I I , p t . p . 312.  , 1.  " T h i s name i s proposed f o r t h e s p e c i e s , Chonetes F i s c h e r i , Norwood and P r a t t e n , a l a r g e , n o r m a l l y concavo-convex s h e l l , w i t h a sub-semicircular outline, o c c u r r i n g i n the o o l i t i c l i m e s t o n e and y e l l o w sandstone o f the B u r l i n g t o n beds o f I o w a . I n t h i s s p e c i e s the c a r d i n a l m a r g i n o f t h e p e d i c l e - v a l v e b e a r s a row o f e r e c t s p i n e s , as i n Chonetes. The beak i s o f t e n compressed o r d i s t o r t e d i n s u c h a manner as t o l e a v e a f l a t t e n e d a r e a , w h i c h r e s e m b l e s , and p r o b a b l y i s a c i c a t r i x from a t t a c h m e n t i n e a r l y g r o w t h . T h i s c h a r a c t e r i s more prominent i n some i n d i v i d u a l s t h a n i n O t h e r s , and appears t o have become c o n s i d e r a b l y obscured b y t h e l a t e r growth o f the s h e l l . The s u r f a c e o r n a m e n t a t i o n i s a l s o p e c u l i a r ; the s h e l l b e a r i n g a d o u b l e o b l i q u e s e r i e s o f c o n c e n t r i c l i n e s , w h i c h g i v e t o t h e s u r f a c e t h e appearance o f e n g r a v i n g on a m a c h i n e - t u r n e d w a t c h c a s e . These l i n e s are w r i n k l e s r a t h e r t h a n s t r i a e , and are s t r o n g e s t o v e r the umbonal and c e n t r a l r e g i o n , where t r a c e s o f them may sometimes be observed on i n t e r n a l c a s t s o f the v a l v e s . The w r i n k l e s are crossed by a normal s e r i e s of v e r y f i n e c o n c e n t r i c growthl i n e s , and beneath t h e s e , b u t n o t always exposed, a r e e x c e e d i n g l y f i n e , crowded, r a d i a t i n g s t r i a e , u s u a l l y v e r y much i n t e r r u p t e d i n t h e i r c o u r s e from beak t o m a r g i n , and o f t e n f l e x u o u s and i r r e g u l a r . Sometimes t h e s u r f a c e i s e n t i r e l y f r e e from t h e d o u b l e s e r i e s o f c o n c e n t r i c w r i n k l e s , and marked o n l y b y t h e f i n e r a d i a t i n g and c o n c e n t r i c s t r i a e . The i n t e r n a l m u s c u l a r i m p r e s s i o n s o f the s p e c i e s have n o t been f u l l y d e t e r m i n e d . C a s t s o f t h e p e d i c l e - v a l v e show t h e i m p r e s s i o n o f a s h o r t median septum d i v i d i n g two b r o a d obcordate f l a b e l l i f o r m m u s c u l a r s c a r s , from t h e o u t e r m a r g i n o f w h i c h sometimes o r i g i n a t e s a s e r i e s o f i r r e g u l a r l y r a d i a t i n g furrows o r r i d g e s , w h i c h were p o o b a b l y of vascular o r i g i n . I m p r e s s i o n s o f a v e r y narrow c a r d i n a l a r e a and e x c e e d i n g l y s m a l l h i n g e - t e e t h are a l s o seen on i n t e r n a l c a s t s o f t h i s valve." Genotype:  Chonetes f i s c h e r i ,  Norwood and P r a t t e n  Superfamily Productacea  (Shrock and Twenhofel, p. 5 2 8 ) .  "Members of this superfamily, the productids, are pseudopunctate brachiopods, typically piano- or concave-convex, with conspicuous spines on the entire exterior of the shell. They are particularly abundant i n Pennsylvanian rocks the world over, but range from Lower Devonian to the end of the Paleozoic. Ranget  Lower Devonian to Permian.  Genera Described: I.  Range:  Genus Devonoproductus Stainbrook  II. Genus Productella Hall  Devonian to Mississippian  III. Genus Strophalosia King Reported occurrence of this superfamily i n the literature reviewed i n Part I of this thesis. I.  Genus Devonoproductus Stainbrook D. walcottl. 5 8  II. Genus Productella Hall.  8 , 9 , 1 0 , 1 2 , 16, 2 1 , 2 4 , 5 1 , 5 4 , 5 5 , 57.  P. belanski Stainbrook. 5 7 • P. callawayensis Swallow. 26. * P. coloradoensls Kindle.  16, 18, 2 0 , 2 1 , 22 , 2 4 , 2 9 , 55,  56,  57.  Kindle. 2 1 .  * P. depresaus P. dlsslmilis  Hall. 2 .  P.  girtyi  Shimer. 5 6 .  P.  hallna  Walcott. 2 0 , 2 2 , 2 6 , 5 5 .  P. hirsute * P.  Hall. 2 5 .  lackrymoBsa  Conrad. 2 , 9 , 1 5 , 2 1 , 5 7 .  75. III. Genus Productella Hall (continued) * P. laminatus Kindle * P. lata Warren. 2 2 . * P. pyxidata Hall P. shumardiana Hall. . 2 2 . P. spinulicosta Hall. P. suboculata Hall.  2 , 8, 11, 2 2 , 2 l i , 2 5 . 36. 2.  IV. Genus Strophalosia King S. productoides Nicholson. 2 .  76*. Genus DEVONOPRODUCTUS Stainbrook, n . Stainbrook  (19U3),  Jour. P a l . V o l .  gen.  17, N o . 1. p . 55.  " S h e l l s m a l l t o medium i n s i z e , p r o d u c t i f o r m , a u r i c u l a t e a t t h e a n g l e s , s t r o n g l y c o n c a v o - c o n v e x , w i t h s t r a i g h t h i n g e l i n e , w h i c h may be l e s s t h a n t h e g r e a t e s t w i d t h , p r o p o r t i o n o f b r e a d t h t o l e n g t h and h e i g h t v a r i a b l e among i n d i v i d u a l s o f t h e same s p e c i e s , ephebic specimens are u s u a l l y l o n g e r than w i d e . P e d i c l e v a l v e s t r o n g l y a r c h e d from beak t o f r o n t , more s t r o n g l y so p o s t e r i o r l y , s t r o n g l y a r c h e d t r a n s v e r s e l y i n t h e c e n t r a l p a r t , and expanding toward the f r o n t . C a r d i n a l a n g l e s depressed and s l i g h t l y e x t e n d e d , a t l e a s t i n e p h e b i c e x a m p l e s . Umbo p r o m i n e n t , h i g h , extended beyond t h e h i n g e l i n e , worn i n most examples b u t a p p a r e n t l y n o t a t t a c h e d . P a l i n t r o p e extremely low, reduced, n e a r l y l i n e a r , i n specimens w i t h c l o s e l y a p p r e s s e d v a l v e s i s o f t e n s c a r c e l y v i s i b l e when examined w i t h the unaided eye. I t i s d i v i d e d i n t o two p a r t s b y a l o w d e l t h y r i u m , w h i c h i s u s u a l l y c o n c e a l e d b y the b e a k . There i s no e v i d e n c e o f a d e l t i d i u m , the space b e i n g o c c u p i e d b y t h e c a r d i n a l p r o c e s s o f t h e o p p o s i t e valve. The e x t e r i o r i s marked b y numerous s m a l l t o minute c o s t a e , w h i c h i n c r e a s e b y d i v i s i o n s e v e r a l t i m e s from beak t o f r o n t . Spine bases i : u s u a l l y s u b c i r c u l a r , sometimes e l o n g a t e , s p a r s e , i r r e g u l a r l y s c a t t e r e d over the s u r f a c e , s i t u a t e d on one or morecostae, w h i c h p a s s t h r o u g h and n o t around the b a s e s . S p i n e s when p r e s e n t a r e e r e c t , s t r o n g , h o l l o w , c y l i n d r i c a l , and more or l e s s p e r p e n d i c u l a r t o the s u r f a c e o f t h e v a l v e . They may have been s e v e r a l m i l l i m e t e r s i n l e n g t h . A l o n g the h i n g e l i n e a r e f o u r or f i v e s p i n e b a s e s , w h i c h p r o j e c t upward and backward i n a manner somewhat r e m i n i s c e n t o f C h o n e t e s . I n t e r n a l l y a deep v i s c e r a l chamber i s d i s t i n c t l y s e t o f f from the s m a l l e r r e m a i n i n g p o r t i o n o f the v a l v e . I t i s s e m i o v a l i n shape and b r o a d e s t a n t e r i o r l y . The p o s t e r i o r and l a t e r a l b o r d e r s are formed b y a r i d g e , w h i c h d i v e r g e s from the base o f the h i n g e t o o t h on e i t h e r s i d e and swings o u t w a r d l y i n a b r o a d c u r v e toward the f r o n t , where i t becomes indistinct. The p o s t e r i o r p o r t i o n o f the r i d g e may be p r o j e c t i n g a i d shelflike. The muscle s c a r s are w e a k l y i m p r e s s e d on f l o o r and are u s u a l l y indistinct. As f a r as can be d i s c e r n e d t h e y occupy a l a r g e p a r t o f t h e v i s c e r a l d i s c and a r e marked b y a few r a d i a l s t r i a e . The r e m a i n d e r o f t h e v a l v e , w h i c h may be d e s i g n a t e d as t h e t r a i l , i s narrow and marked b y many minute rounded crowded p a p i l l a e . The h i n g e t e e t h are g r e a t l y r e d u c e d , m i c r o s c o p i c , b e i n g m e r e l y p r o j e c t i o n s o f the angle formed b y t h e h i n g e l i n e and a s i d e o f t h e d e l t h y r i u m . I n most specimens t h e y are n o t e v i d e n t , o n l y two i n d i v i d u a l s show them u n m i s t a k a b l y . S m a l l d i m p l e s are p r e s e n t a l o n g the h i n g e l i n e beneath t h e s p i n e s , t h e y do n o t appear elsewhere on t h e v a l v e i n t e r i o r . The b r a c h i a l v a l v e i s s h a l l o w l y c o n c a v e , d e e p e s t c e n t r a l l y , a i d  77. i n an area w h i c h broadens l a t e r a l l y and a n t e r i o r l y from t h e beak. Umbo concavej beak s m a l l , rounded, s l i g h t l y e l e v a t e d . S u r f a c e marked b y numerous r e g u l a r l y spaced a n g u l a r c o n c e n t r i c w r i n k l e s o f g r o w t h , w h i c h are s t r o n g l y l a m i n o s e when w e l l p r e s e r v e d . Between the l a m i n a e are numerous f i n e c o n c e n t r i c s t r i a e . C l o s e i n s p e c t i o n a l s o demonstrates the presence o f f a i n t r a d i a t i n g c o s t a e , w h i c h are i n t e r r u p t e d b y the growth laminae. The l a t t e r are homologous w i t h t h e rugae o f t h e p e d i c l e v a l v e and g i v e the c h a r a c t e r i s t i c appearance t o t h e v a l v e . The s h e l l substance where worn appears t o be s t r o n g l y p u s t u l o s e . No p a l i n t r o p e i s distinguishable. I n the i n t e r i o r t h e d e n t a l s o c k e t s are n e a r l y o b s o l e t e and a r e h a r d l y d i s t i n g u i s h a b l e as s u c h , b e i n g m e r e l y n i c h e s between the apophyses o f t h e p r o c e s s and the p o s t e r i o r edge o f t h e v a l v e . Interior distinguisha b l e as a l a r g e v i s c e r a l d i s c and n a r r o w t r a i l . The d i s c i s subovate i n o u t l i n e , b r o a d e s t a n t e r i o r l y and b o r d e r e d p o s t e r i o r l y on each s i d e b y a n a r r o w r i d g e , w h i c h o r i g i n a t e s a t t h e base o f t h e c a r d i n a l p r o c e s s and c u r v e s a n t e r i o r l y t o d i s a p p e a r near the m i d d l e o f t h e v a l v e . B i s e c t i n g t h e v i s c e r a l a r e a i s a n a r r o w , t h i n median septum, w h i c h o r i g i n a t e s a s h o r t d i s t a n c e a n t e r i o r t o t h e p r o c e s s and extends a l i t t l e beyond the m i d p o i n t . M, t h i s p l a c e i t a t t a i n s i t s maximum h e i g h t . The a n t e r i o r p o r t i o n o f t h e v i s c e r a l d i s c i n some examples i s l i m i t e d b y narrow grooves o r i g i n a t i n g a t the a n t e r i o r end o f t h e septum and d i v e r g i n g l a t e r a l l y and p o s t e r i o r l y i n b r o a d c u r v e s t o the r e g i o n i n f r o n t o f t h e p r o c e s s , where they disappear. The muscle a r e a s are f a i n t and o f t e n i m p e r c e p t i b l e . The : s c a r s . a r e e l o n g a t e , f l a b e l l a t e , and do n o t r e a c h the m i d p o i n t . Surface o f the v i s c e r a l d i s c g e n e r a l l y smooth e x c e p t toward the f r o n t , where i t may be s l i g h t l y marked b y r a d i a l s t r i a e . That p o r t i o n o f t h e v a l v e e x t e r i o r t o t h e v i s c e r a l d i s c i s marked, e s p e c i a l l y a l o n g t h e f r o n t , b y numerous crowded p o i n t e d p r o j e c t i o n s . They are s p i n o s e i n appearance, a p p a r e n t l y h o l l o w where b r o k e n , p o i n t e d , and may be termed e n d o s p i n e s . Devonoproductus r e s e m b l e s Products!! 1 a i n shape, i n the p r e s e n c e o f a p e d i c l e p a l i n t r o p e , a d e l t h y r i u m , t e e t h , s p i n o s e p e d i c l e and n o n s p i n o s e b r a c h i a l v a l v e s , i n the p o s s e s s i o n o f a median septum i n t h e b r a c h i a l v a l v e , and i n h a v i n g rugae on the p e d i c l e v a l v e . I t d i f f e r s from R r o d u c t e l l a i n h a v i n g the e x t e r i o r o f the v a l v e s c o s t a t e , the b r a c h i a l v a l v e s t r o n g l y l a m e l l o s e , and i n n o t showing d i m p l e s on the b r a c h i a l v a l v e o p p o s i t e the s p i n e s o f the p e d i c l e e x c e p t i n g a l o n g t h e h i n g e l i n e . Devonoproductus l a c k s a p a l i n t r o p e i n t h e b r a c h i a l v a l v e , has t h e t e e t h and s o c k e t s g r e a t l y r educed, has the v i s c e r a l d i s c o f each v a l v e d i s t i n c t l y s e t o f f from t h e t r a i l , and has a diaphragm i n t h e p e d i c l e v a l v e i n the form o f s h e l v e s a l o n g the p o s t e r i o r b o r d e r s o f t h e v i s c e r a l a r e a . Devonoproductus has a l s o endospines on t h e b r a c h i a l i n t e r i o r on t h e t r a i l . T h i s genus may be t h e r a d i c l e from w h i c h l a t e r genera o f p r o d u c t i d s have been d e v e l o p e d . I t c o u l d e a s i l y l e a d t o P r o d u c t u s by t h e development o f r e t i c u l a t e urabonal r e g i o n s , b y e s t a b l i s h m e n t o f c o n t i n u o u s r u g a e , and b y the l o s s o f t e e t h and s o c k e t s and p a l i n t r o p e . It could also l e a d w i t h few changes t o L i n o p r o d u c t u s b y the r e d u c t i o n o f the b r a c h i a l growth l a m e l l a , p a l i n t r o p e and s p i n e s . "  7 # .  Genus PRODUCTELXA Hall,  sub g e n .  H a l l (1867), P a l . o f New Y o r k , V o l . 17, p.l5>l60 and l62-l8li, p i . X X I I I . " S h e l l s h a v i n g the g e n e r a l form o f P r o d u c t u s b u t u n i f o r m l y w i t h a narrow a r e a on each v a l v e , a foramen o r c a l l o s i t y on t h e v e n t r a l a r e a s m a l l t e e t h , and more or l e s s d i s t i n c t t e e t h s o c k e t s . • The r e n i f o r m v a s c u l a r i m p r e s s i o n s , r i s i n g between t h e a n t e r i o r and p o s t e r i o r o c c l u s o r m u s c u l a r i m p r e s s i o n s c u r v e s g e n t l y outwards, and f o l l o w i n g a c u r v a t u r e somewhat p a r a l l e l w i t h t h e m a r g i n o f t h e s h e l l t o below the m i d d l e o f i t s l e n g t h , i s a b r u p t l y r e c u r v e d and t h e e x t r e m i t y t u r n e d a l i t t l e backwards t e r m i n a t e s about h a l f way between the m a r g i n and t h e a n t e r i o r e x t r e m i t y o f t h e m e s i a l septum. The c a r d i n a l p r o c e s s seen from t h e i n n e r s i d e i s b i l o b e d and from t h e exterior s i d e o f each o f t h e s e d i v i s i o n s i s u s u a l l y b i l o b e d . Discussions I n t h e specimens a f f o r d i n g t h e most s a t i s f a c t o r y e v i d e n c e of area e t c . , t h e foreamen i s open, b u t i n some specimens the i m p r e s s i o n o n l y r e m a i n s , and t h e r e i s t h e appearance o f a narrow i n d e n t a t i o n below t h e beak so t h a t i t i s i m p o s s i b l e t o d e t e r m i n e whether t h e foreamen has been open, o r c l o s e d b y a d e l t i d i u m . "  Genotypes  Productus Subaculateatus  H a l l (1867) d e s c r i p t i o n o f r o d u c t u s p  (Murcaison) subaculateatus.  " V e n t r a l v a l v e g i b b o u s , l e n g t h and b r e a d t h about 7 t o 8. Hinge e x t r e m i t i e s a n g u l a t e d and t h e margins b e i n g c o n t r a c t e d a l i t t l e below form s m a l l e a r s w h i l e below t h i s c o n t r a c t i o n t h e s i d e s a r e r e g u l a r l y c u r v e d and t h e f r o n t i s b r o a d l y r o u n d e d . The umbo i s c o n s i d e r a b l y e l e v a t e d above the h i n g e l i n e , and t h e apex i n c u r v e d . S u r f a c e marked b y c l o s e l y arranged c o n c e n t r i c s t r i a e , and studded w i t h s l e n d e r r o u n d s p i n e s . On t h e upper p a r t o f t h e s h e l l and on t h e e a r s t h e s p i n e s are r o u n d a t the b a s e , and r i s e d i r e c t l y from the surface. On the m i d d l e and l o w e r p a r t o f the v a l v e t h e r e i s a s l i g h t e l e v a t i o n o f t h e s u r f a c e a l i t t l e above the base o f t h e s p i n e , b u t n o t a defined r i d g e . "  79 C0L0RADEN8I8  UPPER DEVONIAN BRAOHIOPODA  PRODUCTELLA  aore a b r u p t l y i n f r o n t . However, the C o l orado and the L o u i s v i l l e e p e c l e e a r e v e r y c l o s e l y a l l i e d , p a r t i c u l a r l y i n the a c a t t e r e d i r r e g u l a r s p i n a baaea of c i r c u l a r outline. Prominent e a r s a l a l l a x t o thoae of the Colorado apecimene a r e p r e s e r v e d on one o f the L o u i s v i l l e s h e i l a . The more a r c u l a t e f o r a and g r e a t e r tendency t o a g e n i c u l a t e f r o n t are the c h i e f a l a t l n g u i a h x a 3 lng features of t h l a soeclea. Round s o l n e oases mark the a n t e r i o r 2/3 of the a h e l l . On w e l l - o r e e e r v e d s p e c i a e n e amall round t u b e r c l e a which do not se<a t o heve been s p i n e s take the p l a c e o f these i n the uabonal r e g i o n . In e x f o l i a t e d a r . e l l a a a a l l round p i t a mark the a o l u o f t h e a h e l l 4 5 6 under the aplne baeee, i n d i c a t i n g a t h i c k e n i n g of t h e s h e l l on the i n n e r aide a t t h e Productella o o l o r a d e n a l a E l a d i t 1909 baae o f the a p i n e a . I n a few a p e c l z e n e t h e 1, 3 , Two v e n t r a l v a l v a a . 8, s i d e n a t u r a l mold e x h i b i t s narrow e l o n g a t e d p i t a profile view of v e n t r a l v a l v e . 4, V e n t r a l c o r r e e p o n u i n g t o s i m i l a r e l e v a t l o n e on t h e valva of tba type epeoiaen. 5, View o f i n t e r i o r o f the v e n t r a l v a l v e . These howInterior of doraal v a l v e . 6, V e n t r a l v a l v a e v e r , do not appear on the o u t e r s u r f a c e •bowing a abort p l i c a t i o n near the f r o n t . of the v a l v e . Fine c o n c e n t r i c l l n e a o f growth mark the s u r f a c e o f w e l l - p r e a e r v e d shells. Prominent c o n c e n t r i c w r l n k l e e Bark PROuuCTELLA COLORADENSIS the e a r s and l e a s d i s t i n c t l y the uabonal r e g i o n . They are absent or i n d i s t i n c t on oductella c o l o r a d e n e l a E l n d l e 1909, U. S. the a n t e r i o r 2/3 o f the s h e l l . O l . Surv. B u l l . 391, p i . I V p. 17. Doraal v a l v e d i s t i n c t l y g e n i c u l a t e i n f r o n t and moderately concave I n the x i d u l e Mature epeciaene enow tendency toward ana p o s t e r i o r p o r t i o n . The s u r f a c e i e a elnua in the v e n t r a l v a l v e . O e n e r a l l y marked ay s m a l l s h a l l o w p i t s aoout c o r r e e p t h l e aaounta o n l y t o a f l a t t e n i n g acroaa ondlng i n nuaber t o tha aplne baaea o l t h a tbe middle of the a h e l l , but i n aoae a h e l l a o p p o a l t e v a l v e . The c a r d i n a l p r o c e a a haa • d i s t i n c t alnua l a present, aa shown i n two a h o r t , e l l g h t l y d i v e r g i n g pronga. f i g . 4 . In p. a e a l g l o o o a a ther l a no such f l a t t e n i n g , the a h e l l p r e s e n t i n g a r e g u l a r l y o i r o u l a r o u t l i n e i n f r o n t . The Colorado fora 1* e l l g h t l y more arched, the beak aora atrongly Incurved and the a h e l l deacenuing  #  W  O  s  UPPEH DEVONIAN BRAOHIOPODA  UEPKE88A  1 P r o d u c t e l l a d e p r e a s a K i n d l e , 1909. 1,2, V e n t r a l v a l v e showing e x i o l l a t e d s u r l a c e and tbe e l d e p r o f i l e . PRODUCTELLA DEPRESSA P r o d u c t e l l a depreaea K i n d l e , 1909, U. S. Oaol. Surv. B u l l . 391, P I . V. P.20. S h e l l l a r g e , broader than l o n g , the prop o r t i o n oeing about 11 t o 8. Tne v e n t r a l v a l v e i e o n l y moderately convex i n the a e a l a n p o r t i o n s , depreeeea aa comoarea w i t h aoet e p e c l e e o f P r o d u c t e l l a , ana haa broad f l a t t e n e d e a r a . A broad and r a t h e r deep a l n u a a a r x a the a n t e r i o r t h i r d of the a h e l l , g i v i n g i t a elnuate f r o n t . The beak and u a bone are a a a l l end l n c o n a p l c u o u a . The e n t i r e e u r f a c e , w i t h the p o s s i b l e e x c e p t i o n of the uabonal r e g i o n , which I s e x f o l i a t e d , i e aarxed by a a a l l e l o n g a t e a aplne baeee p o i n t i n g i o r w a r d . These are r a t h e r nuaeroue i n the a n t e r i o r p o r t i o n o l the a h e l l ana a r e c o m p a r a t i v e l y scarce on the e a r s . Con-  PRODUCULIA  c e n t r i c w r i n x l e e and very l i n e a t r i a e ox growth c o a p l e t e the e u r f a c e a a r x l n g e . T h l a eoeclee aay be compared w i t h P. b l a l v e a t a . P. b o v d l . and 1», Aachjyaaaa v a r . l l a a o i t h e Cheaung, each of which l a c h a r a c t e r i s e d by a alnua I n tbe v e n t r a l v a l v e . The l i m i t a t i o n of tne e p i n e a t o the m a r g i n a l r e g i o n I n the D r a t e p e c l e a , however, u l a t l t . g u l s h e s I t f r o a P. aepreaea. In P. b o v d l the s i n u s ex tends t o the ceax, l n a t e a d of b e i n g l i m i t e d t o the a n t e r i o r p o r t i o n ot the a h e l l , aa i n tr.ia e p e c l e a . I t seeme a l s o t o have a g r e a t e r p r o p o r t i o n a l breadth a t the hinge l i n e than I n P. o o / d l . The gibboua c h a r a c t e r of t h e v e n t r a l v a l v e o l P. lachrvmoaa v a r . l l a a d i s t i n g u i s h e s i t irom P. deoreeaa. whoae b r o a d aepreesea v a l v e hae J u s t keen u e a c r i c e a . A e i a i l a r ana s t i l l more s t r i c k i n g c o n t r a s t e x i s t s between t h l e e p e c l e e ana P. c o l o r a a e n s i a . which i s a s s o c i a t e d w i t h i t .  LACHRTM03A T O - . LDU  U P P E R DEVONIAN BRACHIOPODA  mCCUCTtilA  .... PRCP'XTEJXA LACHRTM03A vsr. LIHA (H»ll  1%7)  Hull Pal of New Tork, Vol. IV. P. 17U PRODUCTKILA LACHRYH03A yar. I.IMA (Hall) Daaerlptloni («ft«r Conrad) Sar.l orbicular lower valve vsntricose, depressed i n tha mllUe. most profound towarda tha bass) surface with numerous e l l i p t i c a l tubercnles d i s p o r t somewhat In quincunx order; umbo ventrloose superior l s t o r s l surfaces much depressed. Vemsrksi Differs from ?. Uehrymosa i n ths depressed mlddls, much more numerous shorter tublcules. The slss Is nf-srly the same. LocalItrt  Chemunj group, Net.' Tork.  lUaars-asi Fig. 1. Ventral valve, regularly ^^^Wrvex. Pig. 3. p r o f i l e of same. Fig. j. shorter mors quadrats form with mesial depression Fig. It. Cardinal visw of same specimen showing muscle markings and cevltlee l e f t by teeth.  LAMIiAT'JS  A  UPPEH DEVONIAN BHACHIOPOOA  a)  •  P r o d u c t e l l a l a a l n a t u a K i n d l e 1909. l , Vent r a l v a l v e of the type e p e c l a e n . a, Hypot h e t i c a l v e n t r a l v a l v e . 3, V i e s of a v e n t r a l v a l v e of a a a a l l I n d i v i d u a l . PH00JC1KLLA LAMINA!US  S  r o d u c t e l l a l a a l n a t u a K i n d l e 1909, U. 8. s o l . Surv. B u l l . 361, p i . IV, l l g e . 13, 14, p. 18.  S h e l l rather a a a l l , eubhealepheric i n outl i n e , w i t h hinge l i n e e l l g h t l y e h o r t e r than g r e a t e e t a l d t h of s h e l l , ano c a r d i n a l anglee rounded. V e n t r a l v a l v e moderately convex. Beak a a a l l , a l l g h t l y o v e r a r c h i n g the hinge l i n e . Surface studded w i t h s l e n d e r , c l o e e l y p l a c e d o p i n e s , and a a r k e d by a a e r l e e of 14 to l b prominent c o n c e n t r i c l a a e l l o a e bands, having a a l d t h of f r o a 1 t o 1 1/2 aa. each, and by very f i n e c o n c e n t r i c e t r l a e . P e d i c l e v a l v e unknown. Thia epocloe r e a e a b l e e i n l t e nuae r o u a f l n a aplnee tbe naxt d e a c r l b e o a p e c l e e , P. a p l n l g e r a , but the u n l f o r a c h a r a c t e r and r e g u l a r apaclng of the l a a e l l o e e banda and tbe l e a s h i g h l y arched v e n t r a l v a l v e d i s t i n guish I t froa that l o r e . Tbe prominent l a a e l l o e e bands, Indeed, d l a t l n g u l a h i t e f f i c i e n t l y f r o a any other s p e c l e e .  PHODUCTELLA  81 Lata  gUQOJCTSLlA  DSVuNIjJJ BRACdlBPObA  Htmur^t: Xhe specie") i s '-nown from two ri>t i e r i n j , e r f e o t j i e a l o l s v a l v e m , both of *.iloh b r a badly e x f o l i a t e d . I n eorse of i t a c b a r a o t a r a t..a m a e l l re»emblem i. donroeaa i n d l e , from t h a uuray l l m e e t ^ n e , but differs i n tna tb«n.ca o f u " i r . u " una I n t i e d i w t r l b u t l o i . ol' t ,e » ir.«". r  r  »»;e L i . a L o c a l i t y : uVj,ar -evonibr.; Uj,jvar bade o f .vdr.r.a*bnVb l i a e - t o r . e . 1 fral'srai.cs  PBUU(0TSU* LiT» A a r r e n 11887) warren, * . " . , » . • . « . Utl  flaaMitlld  :;emoir l b a , 1 » £ 7  ^lttf.rum:  :  ,«.rrer., .-!(..  l V i 7  1 - inctijij.lete  r  valve  e-.ic-e  »»rran  rajanrlpttonj "nail large, alder t i u n long, n o d o r a t e l y oor.vsx. Dinsr.ml r e o f ar. lm. erfeot t  wpeolien:  length, a t learnt'61mm., width, a t  l e e at 66 an. , oor.vexlty o f j . s d i o l e v a l v e b t lsswt  It na.  f s d l o l s valve with g r s s t a n convexity a l i t t l e p o s t e r i o r t o t h e m i d d l e , trie murl'aca xaa r o u n d i n g a l i t t l e more a b r u p t l y toward t n e baav t h a n toward t h e a n t e r i o r n u r g l n . .omtsrol a t a a e l a r e a * f l a t t e n e d . Baa'' wmall, p o i n t e d , and o n l y v e r y a l l g h t l y v r o d u c e - beyond tne  hinge-line.  "urfaoe marked b y ntunerou*, i r r a g u l u r , uune o e n t r l o w r i n k l e * and flr.e l i n e * of growth. * - l n e - b e a e a few, U n i t e d t o t h e l u t e i n , and t  poetero-lateral  'love",  u r o * o f v o r y ,-rominent  o n e * b e i n g " l t u a t s d near t h e h l n e - l i i . a on e i t h e r aide o f n o boav. Breahlal v a l v e liLV-iiomn. mTWTA  ilPPSR DEVONIAN PHACHIOPODA  rHCP JC 8U.< rTfUUTA (Hall 1*58) -  T  -.•slier (1°11») H I . " e d . Surv. Hon.l, p. 100, p i . 19. nPDy;:x:.LA PTHDATA  Deserlptlijni Shell v l i e r than lonr sub semielTTpleTT'ln e j t l l n e , htng» l i n e a l i t t l e shorter than the greatest wltth c r l l n i ' ext-emltlss roundel. Dimensions of an average si -.. I spscimsn hinge 11ns to fre.t r.rgin 11.U unj unbensl region of padlels vslvs to front ..rgln 16.h mi irr»'' s t width 19.1 on. length of hlr.gs l i n e * 17 mnj convexity o' paliela valve 17 **•] depth of visceral eevlty \,t Pedlela vslvs .-.c le-etely cor.vsd greatest convexity rritert>r t' the - t d l l e j unbone] region projects beyord hlnre 11- e, surf see eurvinj abruptly fron the umhr-»: re'ton to ths esrai a l margin curving lass abruptly te the l a t e r a l narglns and .ere gently to tbe anterior margin, strongly ard rather abruptly ooaprasssd towards the cardinal extremities] mssla! sinus ebtrlwve beet small and Incurved. 'rachlsl valve r i t h e r deeply concrve with the surface somewhat deflected towsr Is ths cardincl s x t r ' n i t i e s , the conenvlty rather narrow et the beai and roadenl ,g raFldlv i n t e r i o r l y . v  Surface of both valves marked by more or lese •reviled eenoentrle l i n e s of growth.  HOTUCfxXU  Spina Ware extrc.-ely variable lr. their developaaatf on the pedicle valve they ar« sometimes nearly ebeent except for a few near the cardinal margin and again they are nore or leas crowded and usually arranged in radiating series over tha entire surface sometime t.hey are strong and elonrate ~nd the radiate arrangement is so well defired that tha surf-ce of the vslvs appears airiest to be ri>rked by radiating costae; upon the brachial valve tha spine bassi ar" never so ccnepic Mum* Internally the eardlr.nl process i s s.-ell i f i d with each d i v i s i o n longltuuerslly excavated along i t s pocterior and outer surfwess. Free, ths bass of the cardinsi process a psir of 111 Isfined low broadly diverging ridges extend for one t h i r d cr mere of the distance to the posterior Irteral u r g i n g t h e i r posterior slopes constituting rudlnsntary .!sr.tal sockets. A T.ediur: septum reaehea to Just beyend the middle c f the valve. The greater part cf ths inner surface l a covered by closely crcwded tubsrculsa •ITanged more cr less in a radiating series-. v  Locality end Hcrlsoni  Lower Hississlppien of Missouri.  Slagrami Fig. 1. Pedicle valve, f i g . 2. Brachial valve. Fig. 3. S<<!e view.  62. Genus STROPHALOSIA K i n g 181LLI, n . g e n . I n H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , 1 8 ° 2 , V o l . V I I I , p t . 1 . p . 311*. " S h e l l s p r o d u c t o i d i n g e n e r a l f o r m , a c i c a t r i x , u s u a l l y apparent on the umbo o f t h e p e d i c l e - v a l v e , i n d i c a t e s t h a t t h e y were a t t a c h e d t o f o r e i g n b o d i e s b y t h e substance o f the s h e l l . B o t h v a l v e s have a w e l l d e f i n e d a r e a and c o v e r e d d e l t h y r i u m , t h e s e f e a t u r e s b e i n g much t h e more c o n s p i c u o u s i n the p e d i c l e - v a l v e . I n t h i s , v a l v e t h e t e e t h a r e p r l n e n t , but n o t s u p p o r t e d b y l a m e l l a e ; the m u s c u l a r arrangement i s t h e same as i n P r o d u c t u s , though t h e c a r d i n a l i m p r e s s i o n s a r e r e l a t i v e l y l a r g e r and more e l o n g a t e , e x t e n d i n g beyond t h e lJLmits o f t h e c e n t r a l a d d u c t o r s . o m  I n the b r a c h i a l v a l v e the c a r d i n a l p r o c e s s i s e r e c t , b i f i d on i t s a n t e r i o r , and q u a d r i f i d on i t s p o s t e r i o r f a c e . I t i s s u p p o r t e d on each s i d e b y s h o r t , a r c h e d c r u r a l p l a t e s , and i s c o n t i n u e d i n t o a median septum w h i c h e x t e n d s f o r h a l f t h e l e n g t h o f t h e v a l v e . M u s c u l a r i m p r e s s i o n s s m a l l , q u a d r u p l e , n o t d e n d r i t i c , the i n t e r i o r p a i r b e i n g s h a r p l y r a i s e d . The b r a c h i a l r i d g e s o r i g i n a t e from between t h e a d d u c t o r s c a r s , c u r v i n g g e n t l y outward, r e c u r v i n g , a t f i r s t g r a d u a l l y and t h e n a b r u p t l y t o t h e i r a n t e r i o r l i m i t ; t h e n t u r n i n g s u d d e n l y backward and a g a i n i n w a r d h o r i z o n t a l l y , meeting the median septum n e a r i t s a n t e r i o r e x t r e m i t y . S u r f a c e o f the p e d i c l e - v a l v e c o v e r e d w i t h s p i n e s , w h i c h n e a r the beak are o f t e n c u r v e d backward, embracing some e x t e r n a l o b j e c t . I n some s p e c i e s a l l t h e s p i n e s o f t h e v a l v e have e v i d e n t l y been a t l e a s t o f a c c e s s o r y importance i n e f f e c t i n g i t s a t t a c h m e n t . The s u r f a c e o f t h e b r a c h i a l v a l v e may be e i t h e r s p i n o u s , l a m e l l o s e o r s m o o t h . " Genotype: Range:  O r t h i s excavata, G e i n i t z , = S. G o l d f u s s i , Permian o f E u r o p e .  (Munster) D a v i d s o n .  8J.  Superfamily Rhynchonellacea (Shrock and Twenhofel, p. 32°). "The rhynehonellids are impunctate subtriangular, rostrate shells, characteristically costate, and the delthyrium i s usually closed by deltidial plates. The small foramen l i e s just anterior to the beak. The lophophore i s supported by crura. The Rhynchonellacea are supposedly the earliest and simplest telotrematous brachiopods." Range: Middle Ordovician to Recent. Genera Described:  Range:  I. Genus Calvinaria Stainbrook II. Genus Camarotoechia Hall aid Clarke.  Silurian to Middle Mississippian.  III. Genus Etonia Hall  fcower  17. Genus Hypothyridina Buckman  Devonian Middle to Upper Devonian. Middle Devonian to  V. Genus Leiorhynchus Hall  Permian VI. Genus Paurorhyncha Cooper  Upper Devonian  VII. Genus - Pugnax Hall VIII. Genus Pugnoides Weller  Upper Devonian to Mississippian. Reported occurrences of this superfamily i n -the literature reviewed i n Part I of this thesis. I. Genus Calvinaria Stainbrook * C. albertense (Bell).  18, 22, 33, 37, 38.  II. Genus Camarotaechia Hall and Clarke. 10, 19, 31, 32, 35* C. allani Warren.  22.  * C. banffensia Warren.  18, 32.  * C. contracta Hall.  9, 12, 32, 37*  * C. horsfordi Hall.  18, 20, 21, 22, 33, 37.  C. jasperensis Kelly. * C. nordeggi Kindle.  21. 21, 33, 36, 37.  * C. shimeri Warren. 18, 21 Note:  C. end^ichi Meek = Paurorhyncha endlichi Meek.  84. III. Genus Etonia Hall.  9, 37.  E. pecularis Conrad.  25.  E. v e r i M l i s Whiteaves. 17. Genus Hypothyridlna Backraan. •K H. camerani Warren.  2. 32.  30, 33, 37.  * H. emmonsi Hall and Whitfield. H* magister Balanski.  30, 32. 38  30.  MotetHypothyris cuboides Sowerby the genotype of Genus Hypothyridina has been reported by authors 9, 10. 37. V. Genus Leiorhynchus Hall.  8, 9, 10, 12, 30, 31, 33. 35.  * L. athabaskense Kindle. L. basilicum Crickmay.  21, 22, 23, 33. 39«  * L. cascadensis Warren. 18, 36, 37. * L. castanea Meek. 27, 30, 3k, 37. L. carya Crickmay. 3°. L. clarki Pros ser. « L. glaber Kindle.  11. 21, 22.  L. limitaris Hall.  21.  L. metacostale Merriam. * L. walcotti Merriam. 71. Genus Paurorhyncha Cooper. * P. endlichi VII. Genus Pngnax Hall.  Meek  19.  37. 38. 35  38.  2k, 33, 3k, 36, 37.  * P. minutus Warren. 18. 22. * P. pugnus Martin.  19, 20. 26.  VIII. Genus Pugnoides Weller. 32, 35. * P. salon T. and S. (?) 3U, 37. * P. sandersoni Warren. 30, 3U» * P. subacumlnata.  38.  66. Genus CALVINARIA S t a i n b r o o k , n . gen. S t a i n b r o o k , (19U5) G e o l . Soc.  Amer. Mem. I i i , p. U 3 .  " S h e l l l a r g e sub e q u a l l y b i c o n v e x , t r a n s v e r s e l y s u b e l l i p t i c a l i n o u t l i n e w i t h b r o a d l y rounded a n t e r o l a t e r a l margins, t r u n c a t e f r o n t margin and s l i g h t l y more a b r u p t l y curved angles, much w i d e r t h a n l o n g and l o n g e r t h a n t h i c k , a n t e r i o r commissure s t r o n g l y u n i p l i c a t e . P e d i c l e v a l v e s t r o n g l y and r e g u l a r l y curved from beak t o f r o n t , gently arched t r a n s v e r s e l y , a n t e r i o r p o r t i o n occupied by a broad shallow f l a t bottomed s u l c u s , o r i g i n a t i n g i n t h e f r o n t o f t h e umbo and extended at t h e f r o n t as a b r o a d l i n g u a l p r o j e c t i o n . L a t u r a l slopes gently convex from f o l d l a t e r a l l y b u t more s t r o n g l y c u r v e d from back t o f r o n t . Umbo b r o a d l y convex, rounded and p r o j e c t i n g beyond t h e h i n g e l i n e . Beak b l u n t , i n c u r v e d , b e a r i n g an o v a l foramen which may o r may not be concealed. A n t e r i o r p o r t i o n marked b y s h o r t sub a n g u l a r p l i c a t i o n s , numbering from f o u r t o s i x on s l o p e s and from one t o t h r e e i n t h e s u l c u s ; t h o s e i n t h e s u l c u s s t r o n g e r t h a n those on t h e s l o p e s b u t none r e a c h e s the umbo. Area s m a l l s c a r c e l y d i s t i n g u i s h a b l e . I n t e r n a l hinge t e e t h s t r o n g , f a r a p a r t , unsupported b y d e n t a l p l a t e s . Edges o f c a r d i n a l s h e l f b o a r d e r i n g t h e d e l t h y r i u m t h i c k e n e d so t h a t t h e r e a r e s l i g h t r i d g e s l e a d i n g inward and f o r e w s r d t o t h e edges o f the muscle s c a r . There are, however, no l a t e r a l c a v i t i e s between these r i d g e s and t h e f l o o r as i n Pugnoides. Muscle a r e a d e e p l y impressed, e l o n g a t e , extended t o middle o f v a l v e and b o r d e r e d l a t e r a l l y b y s l i g h t outwardly c u r v e d r i d g e s . D i v i d i n g t h e muscle s c a r s i s a l o n g s t o u t d i s t i n c t median septum which o r i g i n a t e s a s h o r t way i n f r o n t o f t h e apex and r e a c h e s c e n t e r o f v a l v e ; i t i s h i g h e s t and b r o a d e s t a t m i d d l e . B r a c h i a l v a l v e a r c h i n g v e r y g e n t l y from a n t e r i o r margin t o umbo and s t r o n g l y thence t o beak more s t r o n g l y arched t r a n s v e r s e l y i n middle and depressed or s l i g h t l y concave near l a t e r a l margins. F o l d broad, h i g h e s t near f r o n t , narrower and lower t o middle, shortened by l i n g u a l e x t e n s i o n o f o p p o s i t e v a l v e , d e e p l y i n d e n t e d b y a median s u l c u s w h i c h d i v i d e s i t i n t o two s t r o n g p l i c a t i o n s which, i n t u r n , a r e g e n e r a l l y d i v i d e d i n t o two s h o r t p l i c a t i o n s a t f r o n t . L a t e r a l s l o p e s show two t o s i x s h o r t p l i c a t i o n s , umbo b r o a d l y convex s l i g h t l y p r o j e c t i n g . Beak s m a l l , b l u n t , u s u a l l y hidden b y t h a t o p p o s i t e . Internally crural cavity i s s h o r t , opens and b r i e f l y supported b y a median septum. C r u r a l r i d g e s s h o r t , p a r a l l e l t o p o s t e r i o r commisure, and f r o m a n t e r i o r b o r d e r s o f sockets. Median septum t h i n , h i g h e s t p o s t e r i o r l y , and g r a d u a l l y d e c r e a s i n g i n h e i g h t t o i t s t e r m i n a t i o n at o r i n f r o n t o f mid p o i n t . " Discussion:  C a l v i n a r i a e x t e r n a l l y resembles Pugnoides Leionhynchus C a l v i n a r i a internal1 y, u n l i k e those above does n o t have  87. d e n t a l l a m e l l a e b u t a l o w median r i d g e i n t h e p e d i c l e v a l v e as w e l l a s one i n t h e b r a c h i a l and i s more  t r a n s v e r s e i n shape. nm m  alaa.  O  O  O  O  m  CJLVOmU (Ulorhynchua) AI.H*TWSK warren 1926. Htrrtn, P.S. (1928) Trana. Royal Soe. Canada, 3rd Sar., v o l . 22, P i . Sao. 1*, p. 117, p i . 1, flga. 1-$. CALVINARIA  ALBAHTBNSK  Warren  rlptloni Shell aaall for the genua and usually oth aIdea. Brachial reive gibbous with fold at anterior and aupportlng two Bub-equal plication.. Pedicle valve with broad alnua bearing a aadial plication. Oiaanaiona of average specimen Length 10 a a . | width, 13 aa.j convexity 7 aa.  33  Remarket  This l i t t l e shall haa aueh the appearance but tha aadial aaptiat In tha brachial valvo prevents ite inclusion with that genus. On three of tha aany apaelaana examined there is a tendency toward the development of plications along tha edge of tha lateral slopes, end on one apeclaen a third plication on the fold.  a\T~ "  This . p e d e s differs froa L . a^absr A I n d i a by i t a aaaUer alaa and aharpar p l i c a t i o n s . I t baa close affinities with L . p e r r l p l l c e t u a t a l l y ( N M ) froa the Upper Devonian lata Park region. but any aa dietingulahad by i t s e<  la  aaaller The of t a a a m a i t e a r i a a obtained sparvaiatetea i a tha a a a U a a t aaaeiaaa o f L ^ a a e v y y a s t j a . i a  aiaa I t i s p«aal»TyTaVT»e»laTa f o r . of tha latter eaaelea.  our eolleetlona.  at Hay M i the iir»%mmm). tone Werran nealltn  Reported by Wsrran and Stalk  Haogeea protsue  River, N. w\ T. ( U (1926) lists aa creeaaaaexj rmm laetlon aaa aa Wit sad it HcLaren (1950) elao lasers' ita preeanee.  88. Genus CAMAROTOECHIA Hall & Clarke nom.  nov.  Hall and Clarke (189U) Nat. Hist, of New York State, Vol. VIII, Pt. II, p. 189. "By restricting the application of the term Stenoschisma to shells agreeing in hinge structure with Rhynchonella formoso, the necessity i s created for a new designation for the large group of shells to which the term was applied in 1867" Genus STETJOCHISM& Hall, n. gen. Hall (  ) Nat. Hist. New York, Vol. IV, p$  335.  "Shells subtriangular, ovoid or subglobose; hinge line short, beak of ventral valve extended attenuate or more or less arcuate and appressed against the opposite valve. A mesial sinus and fold on the ventral and dorsal valves respectively. Surface plicated with simple or rarely bifurcating plications. "The valves are articulated by teeth and sockets. Strong medial septum in the dorsal valve of many of the species, which becomes thickened in i t s upper part, with a shallow triangular pit in the centre and the crura supported on each side: dental sockets crenulate. The teeth are strong Tv-ith lamellae extending to the bottom of the valve limiting the rostral cavity and sometimes partially surrounding the muscular area. In casts of the ventral valve the cavities made by the diverging lamellae are very distinct; and in the dorsal valve the place of the septum i s strongly marked, the space being wide above, and within this cavity at the upper part there i s a small angular elevation of greater or less extent which originally f i l l e d a depression i n the upper part of the septum." Genotype:  Camarotoechia Congregata (Conrad)  Conrad (181+1) description of Atrypa Congregata quoted in Hall ( I 8 6 7 ) . "Sub orbicular with about fifteen rounded costae crossed by wrinkled lines lesser valve with central part f l a t , slightly elevated, except towards the base where i t i s more prominent,- wide at base and rapidly narrowed above, with four flattened ribs, inferior valve with a regularly concave depression in the middle."  89 DEVONIAN BIUCiUOiOD.  BANIIaW«I8  1  I  8  CAMARCttlCdlA B A N F F K N S I S sarren *arren. r . B . ,  0 . S.C.  a  11*27)  Memoir 162, 1»2T  L . . . r o * ^ h l , hanffa njflj  CAJUSOtOKBUA  a i d - l e n g t h o f the a h e l l ; aurfeoe e l o p i n g abruptly to the p o a t a r o - l a t e r a l aargina. Mesial f o l d obsolete i n the p o s t e r i o r part o f t h a v a l v e am r a t h e r b r o a d and f l a t a n t e r i o r l y , i - l l c a t i o n s s i m i l a r t o t h o s e o f the p e d l o l e v u l v e , A oooupying t h e f l a t t o p o f t h e f o l d and 3 c o n s i d e r a b l y s m a l l e r ones o c c u p y i n g t h a s l o p e on e i t h e r s i d e .  *rrin  leaaarlntloni S i e l l subt r i a n g u l a r I n o u t l i n e , wider than long, tha g r e a t e s t w i d t h i n f r o n t o f tha aid-length o f t h e a h e l l ; posterolateral aargina but a l l g h t l y convex, meeting at tha baav i n an angle o f about 110 degree*; anterior aargln t r u n o a t e , t h e a n t e r o - l a t e r a l aargina rounding r a t h e r s h a r p l y t o i t . Dimens i o n * of tha only apeolman: l e n g t h EC mm., width tt a a . , t h i c k n e s s about 18 mm. fadicle valva l e a s oonvax than t h e b r a o h i a l , rather flattened i n the m i d d l e and e l o p i n g vary abruptly t o t h a p o a t a r o - l a t a r a l merging. Mesial sinus o b s o l e t e i n t h e p o e t e r i o r h a l f o f the valva, b r o a d and s h a l l o w a n t e r i o r l y and produce i upward i n a r e g u l a r l y rounded lingual e x t e n s i o n t o meet t h e l o l d o f t h e braohial valva. Baav a p p a r e n t l y p o i n t e d , but allghtly lnourved and produced beyond t h a t o f tha braohial v a l v a . f l l o a t l o n s s i m p l e , angulur, baeoalng nearly o b s o l e t e a t tha baav, about 86 i n number, o f whioh 12 oooupy the m e s i a l s i n u s . B r a o h i a l v a l v a q u i t e s t r o n g l y oonvex, t h e g r e a t e s t o o n v e x l t y a p p a r e n t l y i n f r o n t o f the  SamarVa: Ihe form b e a r s a c l o s e r e s e m b l a n c e to lamarotoaca.li. a l l e . n a n l a ( a l l l i a a a ) , b u t the p l i c a t i o n s u r e f i n e r and a o r a nuaeroue t h a n those o f t h a t s w e d e s and t h e f o l d and s i n u s o f o u r species are d i s t i n c t l y broaaer taan t a t t o f t h e e a ' t e r n form. »».a  c.r.d L o c a l i t y :  p e r wevoniar.; u , e r cede  o f kinr.e*tn''a Ti:iiestor.e. heferer.ce ; . a r r e n , t. •. , 1**7, sila,  ram:  l i t . 1 - J r a d i c l e vie» r i . t - orc.iial vie* 'if •• - ..uteral vl >« t  r  90 HORSFCRDI  DEVONIAN BRACHIOPODA  m0  CAHAP.OTCSCFIA  on other parts of the s h e l l . The sise varies from a quarter of an inch i n length and five sixteenths i n width, t o nine sixteenths i n length and thirteen sixteenths of an inch i n width, according to age. Geological 'ormatloni Hamilton group, western Mew York.  SAWtOTQtCHIJ HORSFCRDI (Hall J . H a l l . Nat. Hiat. New Part TI, T e l . 17.  1*67)  Tork,  DaearlPtlcnl Shell In M l grown specimens tran evenly sub e l l l p t l o a l j roatral portion sometimes a l i t t l e extendedj front nearly •treight or broadly rounded) langth tc width ae ebeut f i v e to six or seven. Young shells evoid eubtrtgenal. Tentral valve moderately incurved, flattened end Incurved in the frongj a a l l g h t l y depressed sinus, appearing about tha middle of the length Which le flat i n the bottom and eurvinr, abruptly upwards i n frong) bear modsrxtely extended abruptly seute md usually but l i t t l e incurved. Dorsal vslvs very gibbous In old shells sloping abruptly to the beak, dsprssssd envex In young shells. Mesial slsvatlon defined below the middle of the length. Surfape marked by fifteen to twsntyfour well defined angular plications of which four to six or seven marks the neslal sir us or f e l l , which are deeply bifurcated in front. I n the si lea and towards ths oardtnal lateral, margins of ths • h e l l ths pi lost ions are less angulari eoneontrloelly narked by fine undulattng strlaa • i l s h sre seen towar Is ths front but rarely on  Dlagrsnai rig. fig. Vlg. Pig. Fig.  1. 2. 3. U. 5.  Dorsal Ventral Profile Cari'.-al Frtnt  •'lew of a large, well formed characteristic j,»ci.iw»i of 5'*>u les.  91 •dlelKhl  1 £ OilUWTOKdl. VIUKRI B a r r e n  liKVt..1  U»8T)  Barren, t . V , , ».".C. Memoir Its, 18E7  viairoigHi.i ihiBtrt ••»•» Baaarlptlnni • n a i l o r medium a l i a , subovate IB O B t l l n o ; r o l l grown speolmens g i b b o u s , t h e breohiel valve baing muoh mora cor.vax than t h a p a d l o l a ; greatest w i d t h about tha raid-length of tba shall. Dimensions o r an average s p e i l mem langth IT ran. , w i d t h £0 mm. , t h i c k n e s s 10 aa. Padlola T a l v a m o d a r a t a l y c o n v e x , tha grestaa*t oor.voslty bali.g naar t n a umbo. L a t e r a l araa riattanad. tteav s m a l l , p o l n t a a , a c u t a , and but l l t t l a i n c u r v e d ovar t h a t o l tha bri.cnlal Talva. *lnu» "hallo*, rounded i n t h a bottom i n young speoimen* but Deoonur.e r i a t tanad In i o r o g i b b o u a form*, coraienolng about W* mid-length o r tha Khali, r a b i d l y Lroadarii*,a n t e r i o r l y and b a i n g ,-roduced upward i n a l i n g u a l extension t o meat tha t o l d o i tna braohial v a l v a . Braohlal v a l v a mora oonvex t h a n t h a padiol* v a l v a , ths point o r greatest convexity uwually anterior t o t h e raid-length o r the shsllj s tendency toward f l a t t e n i n g e v i d e n t U o n g t h s l a t e r a l margin, f o l d o o m e r o l n , about t h s a l d d l * Of tbo shell and beoonlng q u i t s pronuuruiu. at the anterior m a r g i n , f l a t on top on e t r o n g l y •eaves r e r m o , rounded end r a t h e r p o o r l y d e r i i i e d on lows ooi.vex 1'ormw.  uitau.UUGU  dsMAtDTflKdlA  Surfaoa marVad by rrom 40 t o IC rounded t o s u b u i g u l e r a t r l a a , rrom 1£ t o 16 occupyi n g t h e top and s i d e * o r t h e r o l d and t h e bottom t-nu s i d e * o l the minus, o o e i n g t n e u s u a l number on tne f l a t t e n e d top o l t h e t o l a on the raore convex i o n « . BeiLsrVe; I h i s i s a4.pa1er.tly t h e name rorm d e s c r i b e d , but not r.umeu, c y " h i r . a r , f r o a the L a e kinnewanVa " e c t i o r . . I n »c:.e r e s p e c t s I t r e s e m b l e s s m a l l l o m s o r w. o r . d l l c a l • b u t t.ie s t r i a e are much too f i n e and numerous and t.is l a t e r a l m a r g i n s are not g e n i c u l a t e a s i n that species. I t core c l o ' e l y r e * e a b l e * C. n o r s : o r a l , out mey be d i s t i r . g uisa.ee f r o a t.iat s p e c i e s oy tae r i r . e r ai.d more numerous striae. v  »,:« and L o c a l i t y : UoDar i a v a n i a n ; Bfioeraoat b e a s o r kir.i.eaacVa l i a e s t c r . e or. " u l v h u r lleur.taln. .-velerei.ee: wla>,riia:  -airer., r . ? . . I v i T  * i 1 - x s - i c . e v i e * c: c o - t y , e f i t , . 1 - - r - o a i a l vie., co-tj-,e  92. Genus EATONIA H a l l 1857  n.  gen.  In H a l l and Clarke, Nat. H i s t , of New  York, V o l . VIII, pt. 2, p. 20l|.  "Concavo-convex s h e l l s with median f o l d and sinus, and p l i c a t e d or r a d i a t e - l i n e ate e x t e r i o r , /interior margin deeply sinuate. From the beak of the pedicle-valve diverge two l a t e r a l cardinal ridges which l i m i t a more or l e s s d i s t i n c t f a l s e area. On the i n t e r i o r the teeth are adnascent to the l a t e r a l walls of the valve, a l l traces of supporting lamellae being absent. Muscular area large, f l a b e l l a t e and deeply excavated i n the substance of the s h e l l . Pedicle impression broad, traversed medially by a l o n g i t u d i n a l groove, diductors extending for about one-half of the length of the s h e l l , t h e i r outer margins being elevated, they enclose a pair of small c e n t r a l adductor scars whose posterior margins are r a i s e d into prominent myophores. The scars are divided by a s l i g h t median septum which i s continued p o s t e r i o r l y ; t h i s septum being often rendered v e r y conspicuous by the growth of the s h e l l about the apophyses of the c a r d i n a l process of the opposite valve, and i n extreme cases i t s development i s such that i t r i s e s above, and encloses the adductor scars, the l a t t e r being excavated i n i t s substance. In the b r a c h i a l valve the dental sockets are long and narrow, the cardinal process very large and composed of a stout, erect stem r e s t i n g upon a rather short median septum, and divided at i t s summit into two long, divergent, tooth-like branches, whose upper faces extend to the i n t e r i o r surface of the opposite valve, hence t h e i r greatest elevation i s at t h e i r anterior extremities, whence they slope toward Ihe beak of the valve, usually u n i t i n g before that point i s reached. The surface of attachment of each of these apophyses i s medially grooved. Below them,.and at the base of the central stem, a r i s e the crura, which are long, straight and slender, with expanded extremities. The muscular scars are c l e a r l y defined and consist of a pair of small posterior adductors, and i n front of them a larger p a i r whose surface i s r a d i a l l y s t r i a t e d , the e n t i r e area being elgonate-oval. Vascular impressions are occasionally retained i n the pedicle-valve. Genotype:  Atrypa medialis, Vanuxem. Lower Helderberg group. (Delthyris shaly limestone).  95 Genus HYPOTHYRIDIHA. Buckman 1906" n. nom, Shimer and Shrock  (19^), Index from N. Amerioa, p. 515»  "Subouboidal i n outline and globular i n profile, ventral valve less deep than dorsal, and with long anterior tongue: costae low and rounded, separated by narrow striae; ventral interior with very short dental plates and small muscular f i e l d , dorsal interior without a median septum." Genotype: Atrvpa cuboides Sowerby Range: Middle and Upper Devonian.  CMKRLM  LIVuNIiuN iJReiMiCerOfia  aYfor.iYRIDiK„  C H S R M  ..arren (194.)  warren, I. ?. , I r e n e . Hoy. •oo.Oan. , 3 r d V o l . at, «eot 'n I V , 1*44 a r v B t a r r l d l n a oameronl  "aria*  ...rr.r.  fleenrlptlon: T a i n wueolee 1* p r o b a b l y l i t t l e • o r e t h e n . r a r i e n t o f j , T,|,Vm.. ( H a l l ) . I t d i f f e r . I n t h a t the p e d i c l e v a l v e 1 . more v o n t r l o o w e near the b o a * , than .iall'» »paoie», the l i n g u a l e a t e n . l o n o f the a l n u . 1 a not «o ro l o n g e d upward, and the s i d e * o r the breoha l v a l v e ere much more . l o p i n g to»ard t.ie l a t e r a l mergine. Ihe number of co»tbe on the tongue o f the t h r e e .pool nan* examined i . •even, and the number on eaoh l a t e r a l "lope i s about f o u r t e e n . Ihe d i m e n s i o n s o. t h r e e opeolmens a r e : l e n g t h £4 ma. , £1 m r r . . (ir.com,,:• t » ) , end 19 mm.; w i d t h £6 mm., £b mm., t-nd £1 ma; h e i g h t l b mm. , 16 mm. , und li> n.n. ; viict.i o f tongue 16 mm., 14 mm., and l i mm. m e r e i s a v a r i a t i o n i n the . l i e of the spool r.en., c u t l i t t l e v a r i a t i o n i n other feature*.  {  if- f poalltyi Uppermost k i d d l e l/evonlun. Two .pool-none from the r r e s q u ' i l e o o l o m l t e , f r e o q u ' l l e J o i n t , ureat "lave L.t-e und or.a from drift. a  f i g . 1 - ..rt-ohiel v i s * of syntype F i g . £ - f r o n t a l v i e * or "yntyj-a  laOIHTHirjIKi  94 1  AN BR'CHIOPODa  HYK:H7*-< ID JNA  Brachial va]ve ouxierfct-ly convti tc gioooue; fold subdued, aharply arcned, with the surface sloping abruptly from the borders cf th* fcld tc the lateri»l margin, ivxterior of bctn valves marked by numerous weli-def ir.ed rcunded p l i e c t l o n i which ere neparatfed by sharp narrow furrewa.  HYPC'THYP.EJINA SMMONSI Stainbrcok. Stalr.brcok, 19u5- Geol. Soc. Amer., :-wn. Iii, p. U2, pi. U, figs. 10-11.. hTKTHYRIDINA EMMONSI Stainbrook. D e e c r l p t i o p i Shell variable in size, transversely subcuboidal to subelliptical in profile; generally subpentagoral in outlinej very in equally uiconvex, anterior margin truncate. Greatest width of the shall at midlength or somewhat posterior to the mid- ar.gti.; width greater than length; length and thickness approximately n , .. . Pedicle valve ginUjr convex, sligntly elevated in tha umhonal region, tending in some •pecisiens to become flattened or :ently concave ne r tht posterolateral margin. A broad shallow sinus of variable width extends upward -s a srarp quadrate lingual extension. Pedicle bear usually In contact with the brachial umbo; area obscured. r  hemrrksi (Bell, ^951) Distributier: of Hypctryriiina in the Hocky Mountains shows the* A g e de**r*ir.* * r.5 based on the genus .-re net reliable. In tne Hackemie iriver d i s t r i c t it occurs as low M tha br.se of the Stringocephalua tone, and in this :-«c is obviously not Indicative cf the base cf tne Upper Jevcnian. It is alec report i frca :-erlr_xFluM transit iot.al beds, froa: tne urp-er rardrlX, and frau the Airrxo .Tiember. Liagr-msi 1. Ventral view. 2, Anterior view. }* Lat^ra. view.  95 Genus LEIQRHYNCHUS H a l l n . gen. H a l l (i860), T h i r t e e n t h R e p o r t on t h e S t a t e C a b i n e t , p . 75 (Not i n t h e L i b r a r y of the U n i v e r s i t y of B r i t i s h Columbia. Hall  (1868) Genus L e i o r h y n c h u s . N a t . H i s t , o f N . I . , P t . 6 V o l . U. P t . I , p.  355.  "The s h e l l s o f t h i s genus a r e o v a t e , c i r c u l a r or t r a n s v e r s e , w i t h a median s i n u s and f o l d i n the v e n t r a l and d o r s a l v a l v e s respectively. The s u r f a c e i s p l i c a t e d b y rounded b i f u r c a t i n g p l i c a t i o n s w h i c h a r e always more c o n s p i c u o u s on the m e s i a l f o l d and s i n u s , ' w h i l e t h e y o f t e n become o b s o l e t e on t h e l a t e r a l p o r t i o n o f the s h e l l , c o n c e n t r i c a l l y marked b y s t r o n g l i n e s o f g r o w t h . Substance's o f t h e s h e l l f i b r o u s usual l y t h i n . V a l v e s a r t i c u l a t i n g b y t e e t h and s o c k e t s ; the apex o f t h e v e n t r a l v a l v e p e r f o r a t e a t some p e r i o d o f i t s g r o w t h , t h e l o w e r s i d e b e i n g completed b y d e l t i d i a l p l a t e s . On t h e i n t e r i o r o f t h e v e n t r a l v a l v e two s h o r t d i v e r g i n g d e n t a l l a m e l l a e e x t e n d i n t o and are j o i n e d t o t h e s i d e s o r bottom o f the r o s t r a l c a v i t y ; m u s c u l a r i m p r e s s i o n o c c u p i e s a narrow t r i a n g u l a r o r o v a t e - t r i a n g u l a r space below the d e n t a l lamellae. The d o r s a l v a l v e has a w e l l d e f i n e d septum o f t e n r e a c h i n g b e l o w t h e m i d d l e o f t h e v a l v e and d i v i d e d above, l e a v i n g a t r i a n g u l a r o r spoon shaped d e p r e s s i o n . The h i n g e p l a t e s are n a r r o w , s t r o n g p r o c e s s e s , w i t h s o c k e t s embracing t h e t e e t h o f the o p p o s i t e v a l v e . " Genotype: Hall  Orthis  Quadriscostata.  (1867) d e s c r i p t i o n o f L e i o r h y n c h u s Q u a d r j ^ c o s t a t a (Vanuxem).  " S h e l l b r o a d l y ovate, f o l d and s i n u s .  somewhat gibbous and w i t h d i s t i n c t m e s i a l  V e n t r a l v a l v e a l i t t l e gibbous toxrards beak; f l a t w i t h a wide m e s i a l s i n u s .  sides nearly  D o r s a l v a l v e more gibbous t h a n t h e o p p o s i t e g r e a t e s t c o n v e x i t y i n the middle of the v a l v e ; m e s i a l f o l d prominent. S u r f a c e o f t h e m e s i a l f o l d and s i n u s marked b y t h r e e , f o u r or f i v e rounded p l i c a t i o n s w h i c h b i f u r c a t e above. S i d e s o f the v a l v e s .  96. o b s c u r e l y marked b y rounded p l i c a t i o n s w h i c h become o b s o l e t e towards the m a r g i n , and sometimes t h i s p a r t o f the s h e l l i s almost e n t i r e l y f r e e from any m a r k i n g s w h a t e v e r .  ATHABASCSiSE  UPPER DEVONIjm HR/CHIOPODA  Fi6? LBIOHHTJCHU3 ATHABASCZHSE (Kindle Kindle, E.H.,  1 9 2 ! ; )  Pan. An. Geol. Vol. XLII.  LSIORHTHCHUS ATHABASCBfSE (Kindle) Description! Resembles L. utaher.se Kindle in i t s nan plicated sides, but in '.hp proportions of i t s length and hresdth which aro about 3i$ i t d i f f e r s conspicuouslyI t i s related to - L. Jeffereoner.se Haynes but in the vedgelilce l a t e r a l margins of the shell and in the great elevation of the dorsal valve and very deep sinus shows a different shell expression. Three to eight plications characterise the fold and sinus which are hoardered by the nor. plicated aides. ?he plications do not r e 3 C h entirely tc the beaks. /ge and Locality! L. ethflbaacer.se in the upper part of the Banff limestone on the north side of Folding mountain 1& nlles south of 3ulphur Springs Station, Jasper P.-irk, A3herta. This shell occurs abundantly in the Athabaaca River aectiona. Diagram Fig. 1. Dorsal view Fig. 2. Anterior view f i g . 3. Dorsal vlev.  ""  *  LilCaHYIICrT-i.  97 C«3U»Mi.\Sa  D i V c N l a i l BBAurUrGflA  L U C l H Y N C r l U ! <..SC»DX.\SB * e r r * n U . 8 T ) eerrer., »,#. , Q. M i . Leiorhynotiua  b w a o l r 162,  lvtt  o.acadanoo s e r r e n  Deportation! • o * l l U r n . v e n t r i o o w e . tr»n-v e r a e l y aubovete i n o u t l i n e , - r a e h l e l v a l v e nuoh wore e t r o n g l y o o n v e i t n e n t n * p o d l e l e valve, rroportlor.e o f length to * i d t a v.rying I n a l f f o r o r . t epeel nono. fiiaenalor.* o f on • • • r a f f * "pool-on i l o n g V I L I an. , a l d t h S t a a . . • l a t a St a a . , tni*»n*»» tt a a . r e d l s l e v s l v s aoderately convex, tno p o i n t of g r e a t e s t o o r v e x l t y being W r o n g l y i n c u r v e d , a n t not s s t e n d t n g boyono tbo t»o o f i n s b r a o h l o l v a l v * . " I n s * d s s p . round** a t t n * b o t t o a , ooaaoBOlnf a t t b o Sea* end r a p i d l y w i d e n i n g a n t e r i o r l y t o about n a i f tna a i d t a • f t h s i h s l l ant b e i n g produced upward i s a b r o a d l i n g u a l a s t a n a i o n t o a o o t t b o f o l d on tha b r a o h i a l v a l v e . L a t e r a l a l o e o * r a t n a r a b r u p t I s t i t s aabonal r e g i o n and mora g e n t l y convex a n t e r i o r l y , f l l o a t l o n * i n tne e i n u * r e a t r l o t e d to t h e o o n t r e , t I n nuaber, narrow and rounded: p l l o e t l o n e OS the l a t e r a l e l o p e * r e a t r l o t e d t o t b e a r e a b o r d e r i n g t n * e t n u a , ' i *oae oa*«a n e a r l y o b a o l o t o , f r o a t t o S i n nuaber and auoh w i d e r t h a n t n * p l l o e t l o n * oooupylng t i e a l n u * . v  p o i n t e d and i n c u r v e d , / o l d a t r o n g and w a l l d e f i n e d , oonnenolng near tno boa* a n d basoaing ait,n and p r o a l n e n t a n t e r i o r l y ; t o p roui.ded and b e a r i n g f r o a 8 t o 8 n a r r o w , rounded p l i c a t i o n * i n t a e c e n t r e , lateral • l o p e * rounding a b r u p t l y to tae c a r d i n a l a a r g l n * and mora g e n t l y t o tae l a t e r a l and a n t e r i o r aarglna. x l l o a t l o n * on t a * . a l e r t , • l o p e * l a r g e , about 1 i n n a a b * r , and I n aoa* o a a e * n e a r l y oo»ol*t*. Wit 1*1' f o r a V a l i a a •ac*4«SS**ly i n d l n e n e l o r . a , bat tae aa*t . . . r a s t e r ; * t . e l'aatura* are c . i . a t . n t . I t sls«aly r*w*-*l*^OMm$m W*'»* "««r* r r o a t i a t %sule» lr. I t * g r e a t e r e o h v e x i t y , t a * reui.oad t c p o i tae l e l a ana . . a m c o t t e a a l t.io * i r . a * . aad t a s : e . * r t u a . e r o f p l i c a t i o n * en tae 1*1 d ... »..-..•• * c a * * p * c l a e n * *u.g«*t «-iall i.rt» ,t..i.t.i.ili a n t u i c n i IMeav,, at I .a a l n u * t l - - r a f e k l a a a a r.*Vsr a t t a i i . a «o , r * a t a e . i t u r e l t U v a t o t a * aldtn o f ta ••.«... ana t.-.e p l l e a t i o r . * a r * n * v * r d e v e l o p s *o a:usda>:.t2y a * I s aate'-'a •hell. s  t  aaX-afi  be.aa o i klni.eaai.va l l a * * t . r . e cr. tain.  a.e aWun-  •error., a. *., 1..T. fig. tig. fix*  1 • abttri.r vie* 8 - . rue ..«. v i e a «J - ssdiols v i e * v i a k w M «ld*r * p e v l a * n .  B r a o i l e l v a l v e e t r o n g l y c o n v e x , tbe p o i n t  valva, and tha plleatieae, I U or • i g h t , *#• short and confined to the lo Surface of the younger shall* with pi lest i a s an the sides and stronger iwprwsMd (rwaad p i l e at lone on the mesial f o l d and slnu*. "cceentrt* l i n e * of growth m*rk the upper pert of eeah v a l v a . Tha surface of the older ehelle le aaoeth wit", th* exception of thepllcat lcr.e on the -as l e i felt sat sinus and a few l i n e s of grnwth.  RHTJICHOKaliI.il CAaTAKiiA (Meek 1868) Trene. Chic. Acad. S c i . " a l . 1. p. 93 pi t i l l , f i g * . 9*-c. RHTHCHO'lEX/  —9m,  f i g s . 11a and  '-'or. .8. UU».  Description! Shall sub globose, ventricose on ths dorsal side and sowswhst f l a t t e n e d on the • a n t r a l length and breadth sub equal or a l l t t l s Ion er than wide.  Ventral valve s l i g h t l y convex on the uir.be, flattened or s l i g h t l y convex on tha aides with a more or l s s s w e l l defined sinus which i s f i r s t sesn about the centre of tha valve. The sinus has f r o a three to s i x depressed rounded p l i c a tions and vsrlae f r o * the sub quadrate, liraSulf c r a exten aion with aub p a r a l l e l eioaa on the s c a l i e r ahelle where i t l e etrongly incurved, to the shorter depression outlined by tea e l e v i t d, actute, margins c f ths lower part, which i s not curved beneeth even i n large lr dividual a. Beak abruptly Incurved over that of the oppoelte vslvs. Dnrsn; valve gibbous eloping sor.ewhat abruptly to the aargln of ths opposite valve; the n e s l a l f o l d prominent In younger s h e l l s and asrkwd with three or four p l i c a t i o n s which extend to tha upper t h i r d of the v s l v s . In older spsciasms the fold Is eearcely traceable above the middle of tha  County peak Eureka d i s t r i c t , Nevada, Diagram*! Fig. 'lg. 'ig. Fig.  1. Front view of si .all sub cuboid*! spec lawn, 2. L a t e r e l view of sub eir-cldal speelear.. 3. Ventral view of adult shell. !.. Veatrsl and l i t e r a l view of adult ehalla  aL.«"3>.  I X I O R K Y V C K l ' S 31 Via  OWB  D3Vrvt»-i RRACHICPODA  (Klndl  Kindle, g.X. Pen./*. S e a l , 7 o l . XLII. LBKRHIWC-VS OLAHER (Kindle) joscri^tlcnt S h e l l I f r g e , with ;rcmii*nt TeTin?vFea by t w o h r c d rr-u.ded p l i c a t i o n s end slr.us with • v»«v •*» 'lic.-.tion on enterior he?f. r c l d elnus and p l i c a t i o n s are ebsent on the p o s t e r i o r h a l f o f the sheila Sldea o f s h e l l sr.octh. *he peucity and poor development of p l i c a t i o n s d i s t i n g u i s h t h i s fror. other speci=3 of the genus. siid l ^ c a l l t y i The types rre frcm the '•ri" p r e c r the Banff line3tone on the north side r f 'elding Mountain l j miles south eaet of S l p h u r 3;r ngs j t n t i c n , .'asper Park, Alberta. r  ;  Hiagrar 1 Pig. 1. Ventral view ' i g . 2. Dorsel view Pig. 3. Anterior view.  tALCOTTI  UIOnr.Y..CHJi  UPPah t&VOa I AN BnACHUPOiJA  L. BtAkMSSUUt Wayne*. f i t n i n tha r a n ? * it v a r i a t i o n n L*ior;.yttcua a a l c o t t l Q ' • ur i n d i v i a u a l a n a v i r i * «oaaBual the eopearanoe ot Puguax • g e e a a r e a e n t * . - - H i l ' t y n e , a u t n t.1 a t . , ana  l e n g t h w3 ua., I M U N » H .  H-»rh»uuhua a a l c o t t l a e r r i e a 1M0, I , Carsali l viae v i a * 01 o l no'.styoa, M l o t y o a , se l ilgg h h t l yy reuuceu. r*uui:eu. « - * , , Anterior visas ol oaratypas, a l l g h t l y reduced. LA IOnHYNCH Jb "ALC01 11 Lelorhynchus a a l c o t t l s e m e s (1?«0) l a o l . Soc. a s " . Special paper *6, p. b » , o l . t , llga. « - » . Nature a h e l l , large and robust, laequl vel veu. convexity o l doraal v a l e s greater than that o f ventral. Radial ribbing ol t o l d vary heavy In aoaa i n d i v i d u a l s , rlbe varying f r o a t o o ta about a i l , coaaonly three; eulcue deep at coaaleeure; ribbing ol sulcus e i t r e a e l y v a r i able bat usually heavy. Tbe large also, v e a t r l c o s l t y of tha daraal valva, aad g r s a t w e i g h t o i r a d i a l ribbing aa t o l d and eulcue o i a any var tan t a ara character* i e t i c f e a t u r e a ol' thla eitreaely variable e p e c l e e . L e l a r h y i n h u a e a l c o t t l includsa i n d i v i d u a l s e h l c h r e a r a b i r l o r n * f r o a the Three Paris s h a l e o f Montana; these i n c l u d e Leiori.ycch-a l i t f o r e o n enee Haynes, L. aadlesnfr.of Haynea,  jafca5Sw  1 6 . U na.  100. Genus PAURORHYUCHA Cooper n. gen. Cooper (19*2) WaBh. Acad. S c i . Jour. 52-55 Vol. 8, p. 251. "Large, subtriangular, with unequally deep valves, the ventral one slightly convex but the dorsal one very deep, uniplicate aulticostellate. Ventral interior with much reduced dental plates and small teeth. Muscular area small, elongate-oval. Foramen minute, beak closely pressed onto dorsal umbo. Deltidial plates vestigial. Dorsal interior with long median septum supporting a small V-shaped chamber to which the divided hinge-plate i s attached. Socket plates elevated, crural bases concave, often swollen. Discussion: Differs from Lelorhynchus in the presence of a deep V-shaped chamber. Prom Plethorhyncha i t differs i n the slighter development of the dorsal median septum, smaller ventral muscular f i e l d and mode of thickening of hinge-plate." Genotype:  Rhynchonella endlichi  Meek.  101  Genus PUGNAX Hall n. gen. Hall (l8°li) Nat. Hist, of New York, Vol. 8, Brachiopida I I , p. 202. "Shells with deep fold and sinus; elevated and often accuminate on the anterior margin, more or less sharply plicated, the plications usually being simple, those of the fold and sinus the strongest, those of the l a t e r a l slopes often obscure or obsolete. Pedicle valve shallow; brachial valve deep. Teeth supported by v e r t i c a l lamellae; hinge plate similar i n structure to that of Hypothyris; the median septum of the brachial valve i s extremely feint when present, but i s usually undeveloped. Muscular impressions not large but well defined and clearly subdivided. Vascular sinuses sometimes retained on the pedicle valve, always obscure on the brachial valve." Genotype:  Conchyliolithus Anomites.  102  PUGNUS  uFPJut JAVO&IAN onACHIOPODA  PUGNAX  b e f o r e r e a c n i n g t n e oeax. P l i c a t i o n s i n a i n u e a r i s e i n some s h e i l a i n d e p e n d e n t l y . In o t n e r s tne l a t e r p l i c o t i o n a a r e tne r e t m i t o i o i i u r catlon. Doreel v a l v e g r e a t l y e l e v a t e a a t t r o n t ox tee i o l a , i r o a s h l c h i t a l o p a a a b r u p t l y a o s n e e r a t o tne l a t e r a l margins ana more g e n t l y i o r e a r a t o tne bea*. F o l d maraea by t n r e e t o l i v e p l l c s t i o n e , wnicn are a h a r p l y a n g u l a r a t tbe f r o n t but a r e rounaea p o s t e r i o r l y , ineee g e n e r a l l y become o b s o l e t e about 1/3 o i toe a i s t a n c e i r o a t n e eeaa to tne f r o n t . Tney g e n e r a l l y i n c r e a s e tnrough b i f u r c a t i o n . Proa teo t o t n r e e rounaea p l i c a t i o n s s n l c b a r e Pugne* pugnua M a r t i n , i l l u s t r a t i o n s a l t e r ftlnule 1909. 1, f r c n t p r o ! H e view. a e v e i o p e a o n l y near the a a r g l n ox tne a n e n 2, 3, 4, D o r s a l , f r o n t , ana v e n t r a l v l e e e are p r e s e n t on each s l a e o l the s i n u s . Tha o f an I n d i v i d u a l . 5, 6, V i e e s o l tbe l i n e ox c o n t a c t o e t s e e n tne p l i c a t i o n s ana l e r g e e t and most abundantly p l i c a t e d t n e i r I n t e r m e d i a t e txougne l o r as a s e r i e s ox e h e l l ooservea. very a c u t e anglee a l o n g t n e a n t e r i o r margin o f the v a l v e e . PUGNAX PUUHUS In some s e l l p r e s e r v e d specimens t o e s u r i a c e o l botn v a l v e s l a c o v e r e d by t i n e PugneJ ougnua M a r t i n , d e e c r l o t l o n a l t e r r a a l a t l n g s t r i a e , p r o b a b l y sr. e v a n e e c e n t K l n a l e ( 1 9 0 9 ) , U. S. G e o l . Survey B u l l . No. 391 c h a r a c t e r , ae a t r i a e n o t c l e a r on o t h e r p. 4 2 , p i . V i , f l g e . 3-tta. a e l l p r e s e r v e d specimens, i t a a i e i l n g s t r i a e tena t o enow temporary ana l o c a l development S n e n t r a n a v e r s e l y ovate ana e l e v a t e a i n a h i c h oecame f u l l y a e v e i o p e a i n sues Car c o n . l r o n t . P r o p o r t i o n e o i l e n g t h ana b r e e d t n i f e r o u s forme a s P^SBSO. a l a s o u r l e n a i a . sea* ere about 6 t o 7. v e n t r a l v a l v e e i l g n i i y a h e l l e enoa i n a l s t l n c t , l a m e T l o e e T c o n c e n i r i e concave i n uabonal r e g i o n , b u t n e e r l y f l a t striae. on a l t n e r e i a e o: tne e l n u e . Beax o i v e n t The l e r g e e t l n d l v l u u a l o b e e r v e a , e c i c n apr a l v a l v e p o i n t e d ana I n c u r v e d over beat o i peere t o r e p r e s e n t a g e r o n t l c s n a i l , d l j i e r e o p p o e l t e v a l v e . Slnue oroaa, aeep i n f r o n t , i r o a tne above o l s c r i p t i o n i n t n e g r e a t e r oeglne about 1/4 tne a l a t a n c e i r o n tne bees nuaber ana prominence ox the p i l c e t i o n e . to the f r o n t ar.u oer.ua anaxply upsaru aa a m e r e a r e 14 on eacn v a l v e , 5 ot a n i c n occupy uroad l m g u l i o r m e x t e n s i o n i n t o tne o p p o s i t e tne f o l d and 4 tae o l n u a . Tne l a t e r a l p l i c a valve. Froa t e o t o l o u r s t r o n g r a a l a t l n g t i o n s a r e s e l l a e v e i o p e a n e a r l y t o the beaxs p l l c a t l o n a ^ r n e r a l l y occupy tne s i n u s , ana T h i s specimen haa a l e n g t h o f ao ma. and a b r e a d t h o f 36 a a . teo rounaea p l i c a t i o n s are p r e s e n t on each s i d e o i i t . All o i t.ifee c t c o i e o b s o l e t e  105.  Genus PUGNOJLDES , F Weller, n. gen. Weller (1910), B u l l . G.S.A. V o l . 21,  p. 512.  "One of the rhynchonelloid s h e l l s which has been commonly r e f e r r e d to by recent authors to the genus Pugnax i s Rhynchonella ottumwa (White).A series of cross sections of t h i s species i s reproduced (Plate ) i n which i t i s shown to possess a l l the essential characters of Camarotoechia. I f , however, i t i s legitimate t o recognise such genera as Wilsonia and Leiorhynchus, genera possessing e s s e n t i a l l y the same internal structure as Camarotoechia, and based p r i m a r i l y upon external form and ornamentation of the s h e l l , then R. ottumwa with i t s external aspect of Pugnax must also be excluded from Camarotoechia and there i s no genus i n which i t can be placed, i t becomes necessary t o establish a new one f o r i t s reception. This genus may be c a l l e d Pugnoides with P. ottumwa as genotype."  Genotype:  P. ottumwa.  DSVONIAN BR<CHI0P01)A  PUUNCHES  facurrencei Reported by Warren end Stelk (1950) froa the uyrtlna panda lone i n the deevertail Llr.eatane at lereljou Hock, below Fort •Jomsn. N.W.T. ' maiOmSS SCUM Thomas and Stainbrook Kenton and Kenton, 1924, Mich, UnlT. ltuo. Seal. ^ontrlb. m l . 1, p. 129, p i . 35. f l e e . 9-12. PUGMOIDE3 Sam  Thomas and Stainbrook  Description! Deninaions taken free tare t>plcal apoc linens collected at Solon, Ia.j le..gth U.6 no. and 12.8ran.| width, IS na. and 17.It nm.j thickness, 11.7 ro. and 13.2 am. Pram these i t w i l l be seen that, i n proportion, the species differs froa P. c a i T l n l i n greater width, lesser thickness, more abrupt, f l . i t bottomed sinus, smoother umbonaJ .•egioi:, f l a t t e r , lower and more flat-toned f o l d , and greater general compactness of proportion.  Dlegraaai  1. Ventral v i e s . 2. Anterior eiow. 3. Lateral view.  104  suucimntm  romionas  SUBACUXMATA  taraiAN  uebeter  Stainbrook, 19u5, Gaol. Soc. Azaer., Meai. l b , p. 13, p i . o, f i g s . 20-21. PuaomSS SUBAClDtPUTA Webster. Description! Shall eeneuhst variablej subtriangular In marginal outline! greatest aldth above the centre of the shell) contracting quite rapidly to tbe front, where I t terminates in three sharp anglee, which aro produced by the sharply angular folds on the front of the valves. IXTsal valve atrongly convex In the center; furnished with three prendnant angular sharp folds at tbe front, which usually become obsolete before reaching tha center of the shell) sinus large, deep and brc.dly rounded; margined i n front by from two to three sharp, short folds; front and c r d i u a l aargina sharply serrate. Surface of ahell smooth; texture fibroue. In young aivclmena of this species folds or elevations are net present on any portion of the s h e l l .  ivmcass  BRACK I C W D A  Age and Occurrencei Noted by Stainbrook iron the Lima crook 'ornation (Haekberry Stage)| and from the Perdrlx at Ran Oap In the Becky Mountains. Diagramsi  1. Anterior vlewe of 2. two individuals.  105  rGKARUtJEI  DEVUNI/.'J HRZ-CHIOrODJI  ORT:ilS  cnglea to ths plane cf the valvss) foremen t r i angular, and about two-thirds as wide as nigh. Similar or ventral valve convex in ths l a t e r a l aid umbor.sl rc-glcns, the most gibbous part be trig near the beak, which i s short aid • l i t t l e incurved st tlie pclnt) provided with s broad rounded mesial slnue, which eomnencea very shallow nair ths Kiddle of the valve, and wldana and deepens rather rapidly towards ths front margin to which i t imparts t broadly eaiarglnate outline. Larger or dorsa.i valve extremely gibbous, particularly in the region of the umbo, which, i n adult specimens, projects eensHerpbly beyond that of the other, and i s at a l l ages strongly incurved. Surface marked with fine r^diM:. s t r i a e , sane nine or ten of which may be counted in ths apnea of 0.11 inch. ORTHIS HcFffiLAKSI lisek (186B) Trans. Chic.Acad. S c i . Vol. 1. p. flfl. >MTH.1S KCPAH1.AN&I Keek Descr iptloni Snail subcordate, resuplnate, very gibbous) length (In adult examples) greater than the breadth) cardinal and umbonal regions very narrow) posterolateral margins straight, and rapidly diverging forward to the widest part of the valves, w h i c h l r a l i t t l e tn advance of the middle) hin.;e l i n e short or scarcely euallng half the ( T v s t e s t breadth cf the valves) cardinal nreamodsrate, nearly twice as high in the ventnu valve as lr. the ether, strcngl;.arched in t b e dorsal v a l v e , and s l i g r . t l y i n the ventral, . h e r e ".t i s less than half aa h i , ; ! ! as wide, r:i.i r.u-.^es r . e r r l y s t r i g h t y  Sreadth of an adult, l . ? t inches) lengtn fre.-i the most rarcninent part cf the umbc of ths ventral valve to the front, i.60 Inches. Qrertest convexity of the two valves, 1.16 inches) length of hinge, 0.77 inch. Localityj Forty .miles below Fort Good Hope on Hackenaie r i v e r , and on Loekhart r i v e r , 1st. 47 i e r . IS min. >:., long. 126 dog. W., i n the Devonian (Hamilton group.) I heve also seen speclxens wl'ich I believe to -olong to t h i s species iron, the Husiltc group beds of Iowa and I l l i n o i s . Diagransi  1. Side view  2. filter' cr view 3. ucrsa. view u. .osttri'-r view  5. Ventr.--; view.  106. S u p e r f a m i l y A t r y p a c e a (Shrock and T w e n h o f e l , p . 330). " A t r y p i d s a r e subquadrate s p i r i f e r o i d s w i t h a complex b r a c h idium. The p r i m a r y l a m e l l a e f o l l o w themargins o f t h e s h e l l , and t h e s p i r a l i a are d i r e c t e d i n w a r d o r t o w a r d t h e f l o o r o f t h e b r a c h i a l valve. Ranges  M i d d l e O r d o v i c i a n t o Upper D e v o n i a n .  Genera D e s c r i b e d :  Ranges  I . Genus A t r y p a Dalman  S i l u r i a n t o Devonian  I I . Genus G r u n e w a l d t i a Tschernyschew Reported occurrences o f t h i s superfamily i n the l i t e r a t u r e reviewed i n Part I of the t h e s i s . I . Genus A t r y p a Dalman.  2k, 31, 32, 33, 35, 3 6 .  * A . a l b e r t e n s i s Warren.  30, 37* 38.  * A . andersonensis Warren. *  A . a r t i c a Warren.  30, 3k, 37.  A. aspera Schlotheim. A. bentonensis  30, 3h, 37«  11.  Stainbrook.  37.  * A . b o r e a l i s Warren. 3 7 . A. bremerensis  Stainbrook.  * A . c l a r k e i Warren.  30, 37, 38.  A . cosmeta C r i c k m a y .  39•  * A . devoniana Webster. * A . gigantea Webster.  37.  30, 37, 38. 37, 38.  A . g r e g e r i Rowley. 2 6 . A. h a y r i v e r e n s i s Warren.  38.  A . h u c k e l b e r r y e n s i s F e n t o n and F e n t o n . * A . independensis Webster. * A. missouriensis M i l l e r .  37«  37 18, 20, 22, 3 1 , 3 6 .  I . Genus  A t r y p a Dalman (Continued)  ' •  A. montanensis  37.  A. owensis  37.  A. p e c h i e n s i s G r a b a u .  37.  A. r e t i c u l a r i s L i n n .  2, 8, 9, 11, 12, 1 3 , 15, 16, 1 9 ,  20, 22, 2U, 25, 26, 35, 36. • A. s c u t i f c r m i s S t a i n b r o o k . •A.  spinosa. H a l l .  37-  8, 9, 10, 12, 19, 20, 22, 25,  36. II.  Genus G r u n e w a l d t i a Tschernyschew.  35.  26,  106  Genus ATRYPA Dalman, 1828 n. gen. In Hall and Clarke, Nat. Hist, of New York, Vol. VIII, pt. 2, p. 163. "Diagnosis: Shells subcircular or longitudinally suboval in outline, ^ibbous, strongly inequivalve. Hinge-line short, straight; cardinal extremities rounded. Beaks not prominent. Pedicle-valve the smaller; convex in the umbonal region, but depressed and often deeply sinuate anteriorly. Beak small, usually incurved in advanced growth-stages, concealing the foramen and deltidium. The foramen i s triangular in young shells, extending to the hinge-line, but becoming gradually closed by the growth of d e l t i d i a l plates, and at maturity i s circular and apical, encroaching slightly on the substance of the valve. The plates of the deltidium are not coalesced along the median sature. On the interior the umbonal cavity is short but very broad. The teeth are large, widely separated and doubly grooved, f i r s t by an oblique furrow at the base, into which i s fitted a crenulated ridge of the other valve, then by a short longitudinal depression on the summit; the tooth i s doubly curved and reflected, making the articulation of the valves very firm. These teeth arise from the inner surface of the lateral slopes of the valve, and are hence unsupported by lamellae. The muscular impressions are sharply defined; the triangular pedicle-scar i s followed in front, by a median elongate double scar of the adductors, outside of which are strong, radiately striate, flabellate diductors, which frequentl y extend beyond the middle of the valve. Brachial valve convex or rotund i n the middle, with a median fold which i s rarely developed except toward the anterior margin. Beak incurved and concealed. No cardinal area. The hinge-plate i s composed of two diverging processes which may or may not meet at the apex. Each of these processes i s obliquely grooved, forming an inner and outer lobe. The latter forms the upper portion of the socket wall which i s curved downward and unites with the lateral surface of the valve, forming a broad dental socket which i s traversed by an oblique crenulated ridge. The inner lobes of the hinge-plate are short, their extremities free, bearing the crura. These crura are long and narrow, diverge laterally and are attached to the primary lamellae near their ante-lateral curvature. The mode of attachment i s peculiar, the crural lamellae bending upward and then abruptly downward, greatly widening at the line of contact and touching the spiral ribbon only J at i t s outer margin. The demarkation between the crura and the ribbon of the coils i s therefore very distinct. The spirals have, in a general sense, their bases parallel to the inner surface of the pedicle-valve and the apices directed toward the deepest point of the opposite valve. Their axes are more or less convergent, so that the approximate surfaces of the cones are flattened. The basal section of these cones i s hemicordate, the anterior extremity being much the narrower, but the upper volutions are more nearly e l l i p t i c a l . The  109. ribbon i s broad, being conspicuously so on the anterior curves of the f i r s t few volutions, each one extending considerably beyond the next following. These anterior curves may be more or less distinctly fimbriated. The loop i s composed of two processes which are continuations of the primary lamellae without angulation. These processes are situated posteriorly, directed toward the center of the shell, and are, in effect, the starting points of the spirals. They have the following structure: the ribbon maintains i t s usual width for a considerable distance within the point of attachment to the crura, then narrows rather abruptly, the processes ascending as they approach each other. Their terminations in mature shells are broadened, thickened, erect and recurved at the tips, having a clavate appearance. In immature growth-stages or undeveloped adult conditions this thickening i s absent, the axtremities of the processes are in close apposition, or may form a continuous lamella. The muscular impressions consist of four large adductor scars divided by a low median ridge. Ovarian pittings and vascular sinuses occur over the inner surfaces of both valves. The latter consist of twomain trunks, sending two branches posteriorly, and two longer, converging branches anteriorly. External surface covered with radial plications crossed by concentric growth-lines, at the crossing of the two series of lines the external layers of the shell may be produced into broad lamellar expansions or hollow spines. Shell-substance fibrous, impunctate. GenotypeJ  Anemia reticularis, Linne. groups inclusive.  From the Clinton to Waverly  110  ffltlfflHAU  UPPffl OSVCHlaS BSACHIOPOB*  ilRTTi  Surface o f both valves ornratntad by coarse pouudad costae of which 8 c r $ reach the beak.. They increase i n number by b i f u r c a t i o n or ii.iplantatlon t o fifteen or eighteen along the margin. They ere crossed by numerous i m b r i c a t i n g lamellae which In mature specimens may become crowded at the front margin and are there IS l i t t l e evidence t h a t the lamellae are produced into spines an the c r e s t o f the costae. ATRYPA AIBBgTgJSIS (Warren 19UU) Vacrrenj P . S . Trans. Royal Sec. Canada. 3rd S e r i e s , V o l . TJXVIII, Section 17. p . 118.  Remarks! convexity, e r e c t beak specimens) absence of  ATRYPA ALBgyrgSIS (Harren)  G e o l o g i c a l Horizon;  Description! S h e l l s n a i l t o median s i z e d , e q u a l l y convex and sub c i r c u l a r t o sub quadrate length and width about equal, t r e a t e s t width about the mldlength o f the s h e l l , may be s l i g h t l y sinuous along the front margin In o l d specioens. Dimensions c f 3 specimens, length 20 ran. 18 mm. 17 mm.} width 21 mm. 19 mm. and IS mm.] thickness 10 emu 11 una. 9 mm.  Localltyi  P e d i c l e v a l v e moderately convex throughout w i t h no tendency t o f l a t t e n towards the margins, but i n some specimens nay develop a broad, very shallow alnua near the front margin. C a r d i n a l shoulders rounded t o sub angular; beak e r e c t and not curved over t h a t of the opposite v a l v e (The beak i n o l d specimens i s u s u a l l y worn back and the fareamen i s accordingly l a r g e . ) B r a c h i a l v a l v e moderately convex w i t h a tendency t o f l a t t e n a t the p o s t e r l o l a t e r a l margins i f tha c a r d i n a l angles are not rounded. Eo d e f i n i t e f o l d produced, beak small end sharply incurved.  Thla species i s d i s t i n g u i s h e d by i t a moderate the equal c o n v e x i t y o f the two v s l v e s , i t s i n the f e d i c l e v a l v e (worn i n mature the sub c i r c u l a r form coarse costae end the spines. Waterways P o r a a t l o n .  /Ithabsska River a t McHuxry, A l b e r t a .  Types: Syntypea Dv. 861-S6U. Diagrams! F i g . 1. P e d i c l e v a l v e . P i g . 2 . Side View. F i g . 3. "frachial v a l v e .  Ill  DBVOHIAHA  UPPER DEVONIAN BRACHIOPODA  1  3  4  3  5  e  1 A t r y p a d e v o n t a n a Sebeter (Form A), o r a c b l a l v l e a o l a t h i c x specimen. ( A f t e r f e n t o n and Penton, 1935, p i . 3 7 , f i g . 1) 2 A. d e v o n l a n a S B o s t e r (Form B ) , p e d i c l e v l e a o f a specimen ahoae l a m e l l a e are n o t p r e s e r ved. ( A f t e r f e n t o n ana Fenton, 1935, p i . 3 7 , fig.a) 3 A.devonlana S e b s t e r (Form C ) , b r a c h i a l view. ( A l t e r Penton and Fenton, 1935, p i . 3 7 , f i g . 7 ) 4-6 A . d e v o n l a n a S e b s t e r , b r a c h i a l , s i d e , and p e d i c l e v i e w s . ( A f t e r Sblater and Shrock, p i . 141, F i g s . 16-18) ATRYPA U E V O a i A H A D e s c r i p t i o n : L i k e A. w a t e r l o o e n s l s t h i s s p e c i e s ahoss such g r e a t v a r i a t i o n t h a t i t may be c o n s i d e r e d by groups or 'forme". U n l i k e t b a t spec i e s i t s forms d i f f e r so g r e a t l y t h a t no g e n e r a l d e s c r i p t i o n seems a d v i s a b l e , though the c h a r a c t e r s o f o r n a m e n t a t i o n s p e c i f i e d under f o r m A may be r e g a r d e d as t y p i c a l . Specimens i l l u s t r a t i n g ioTmo are r e g a r d e d as i y p o t y p e s ol" the s o e c i e s .  ATRYPA  Form A ( F i g . 1) S h e l l medium t o l a r g e , a l d t h as g r e a t as l e n g t h o r , more t y p i c a l l y , g r e a t e r t h a n l e n g t h , e s p e c i a l l y where l a m e l l a e a r e p r e s e r v e d . D i mensions o f two t y p i c a l specimens w i t h o u t l a m e l l a e : l e n g t h o f b o t h p e d i c l e ana b r a c h i a l v a l v e s , 33.3, 24.6 mm.; w i d t h , 23.3, 25.3 mo.; t h i c k n e s s , 15, 18.2 am. P e d i c l e v a l v e q u i t e convex i n e a r l y stages', l a t e r a l a r e a s s l o p e g e n t l y from c e n t r a l convexi t y to margins,' i n some specimens, e s p e c i a l l y those whose l a m e l l a e are p r e s e r v e d , a c o n c a v i t y l e formed i n the l a t e r a l r e g i o n s ; s i n u s appears 13 t o 15 mm. from the beak, broad and s h a l l o w , 7.5 to 10 mm. wide I n t y p i c a l s h e l l s . B r a c h i a l v a l v e h i g h l y convex; lamellae, l a t e r a l l y , e x t e n d outward and r e c u r v e ; f o l d i n d i s t i n c t e x c e p t near a n t e r i o r margin; cardin a l a r e a s rounded, h i n g e l i n e s t r a i g h t ; be ox h i d d e n by r e c u r v e d beak o f p e d i c l e v a l v e : I n d i s t i n c t f u r r o w on umbo. Surface marked oy p l i c a t i o n s t h a t i n c r e a s e I n number by b o t h b i f u r c a t i o n and i m p l a n t a t i o n ; ? t o 9 i n 5 mm. a t 10 mm. from p e d i c l e bene; growth l i n e s numerous, e s p e c i a l l y near a n t e r i o r margins.  112  UIOABTSA  TJPP&h OETOBIAS BKACHIOPODA  1  It  1,4 A t r y p a g l g a a t o a S e b s t e r , b r a c h i a l view o i a l a r g e s p e c l s e n and p e d i c l e v l e a ox* a s m a l l e ? o n e . ( A f t e r Btalabrooft-, 1938, p i . 3 0 , f i g s S, 1 8 . ) ATHTPA aiOABTtA Webster Atryps. filgantoa S e b s t e r , 1831, A a . M i d i ana Bet., T O I . 7 , p . 1 6 . - Fenton a w l F e n t o n , 1935, J o u r . P a l e o n t o l o g y , v o l . 14, p . 2 3 3 . S h e l l l a r g e , e u b o r b i c u l a r , l a t e r a l margins b r o a d l y rounded, v e r y u n e q u a l l y b i c o n v e x , a l d e r than l o n g , b r o a d e s t t o the o l d l e n g i h , h i n g e l i n e s t r a i g h t and l e e s than the g r e a t e s t a l d t h , rounded a t the a n g l e s . Dimensions o f too h y p o t y p e e : l e n g t h , S O s o . , and 39mm.t w i d t h , S B . 7 . , and 45.omm.| t h i c k n e s s , 27.6mm.. and 21.6am. P e d i c l e v a l v e g e n t l y concave, a l i t t l e convex i n the unbonal r e g i o n , whence t h e s u r f a c e e l o p e s g e n t l y a n t e r i o r l y and l a t e r a l l y , ana then r i s e s t o the m a r g i n s . Be a* s h o r t , p o i n t e u , i n c u r vea, p i e r c e d by a foramen a t the aoex. Greatly thickened i n t e r i o r l y . suite l e s c a r e d e e p l y suna-en. B r a c h i a l v a l v e l o n g e r ar.u i-ore CDavex than p e c i c l e , gr, utett c:>:.vexity p j e t e r l s r t o the  ATRYPA  m l d l e u g t h ; h i g h e s t I n the umbonal r e g i o n ; s u r face s l o p i n g e i t n moderate r a p i d i t y t o toe f r o n t ana l a t e r a l m a r g i n s , f l a t t e n e d s l i g h t l y n e a r the a n g l e s , I n c u r v e d beneuth tne b e a k . Umoonal r e g i o n p r o m i n e n t , p r o j e c t i n g a l i t t l e beyond the hinge l i n e . R a d i a t i n g c o s t a e numerous, l e s s t h a n medium e l s e , I n c r e a s i n g oy d i v i s i o n , aoout f o u r or f i v e i n f i v e m i l l i m e t e r s on the umbonal r e g i o n of a l a r g e specimen. Growth l i n e s p r o m i n e n t , a o r e crowded and l a m e l l o s e near tbe a n t e r i o r and l a t e r a l m a r g i n s . This species resembles Atrypa w a t t r l o o e n s l a i n shape, but I s re s u l l y s e p a r a t e d oy I t s s m a l l e r c o s t a e , which are about b a l l as l e r g e . It l i e s aoove t h a t form i n much of the Cedar V a l l e y area. The form d e s c r i b e d as Aj. w a t e r l o o e n s l s w e b s t e r l Fenton and Fenton l a p r o b a o l y the same.  113  IMBSPSa'iJ&.NCIo  JPP&n JSVOHlAM SHACHIOPOUA  ATBIPA  P e d i c l e v a l v e convex umbonally; i n young apec l s e n s , 10 t o 2 5 am. l o n g , e q u a l to the B r a c h i a l ; p o a t e r o - l a t e r a l a r e a s i l a t t e n e u on e i t h e r a i a e o f the umbo. I n the n e a n l c s t e g e a e x t r e m i t i e s rounded, i n e p h e o i c and g e r o n t i c s t a g e s a n g u l a r or a u b a n g u l a r ; h i n g e l i n e s t r a i g h t o r n e a r l y ao t h r o u g h o u t ; i n n e a n l c s t a g e p e d i c l e b e a t prominent, e x t e n d i n g beyond b r a c h i a l v a l v e , • 1 t h v e r y a a a l l foramen. With growth, beak b e come e I n c u r v e d , f i n a l l y bent c l o s e l y over beak o f b r a c h i a l v a l v e , w i t h foramen c l o a e d . C a r d i n a l a r e a s m a l l ; i n e p h e b l c and g e r o n t i c s t a g e a , l i k e the foramen, i t i e more or l e e s h i d d e n by the v e r y convex b r a c n i a l umbo. About 40 a a . i r o a t h e b e a t the s h a l l o w , r a t h e r b r o a d s i n u s a r i s e s ; l a m e l l a e obscure i t , g i v i n g p e d i c l e v a l v e i n g e n e r a l a f l a t apoearance. In a hypo t y p e , a a l i g h t c o n c a v i t y appears b e t s e e n growth l a m e l l a e 17 t o 24 a a . f r o a t h e b e a t ; a t 24 am. a l a m e l l a e x t e n d s outward u n t i l ( i n one p l a c e ) i t l a 12.5 am, beyond t h e margin o f t h e b r a c h i a l v a l v e . B r a c h i a l v a l v e r e g u l a r l y convex u m b o n a l l y , r e c u r v e d toward tbe e x t r e m i t i e s , f l a t t e n e d l a t 1,2 A. lndependencle B o o s t e r , p e d i c l e and e r a l l y ; f o l d , a b r o a d , rounded t o a u b a n g u l a r brachial, vleea. e l e v a t i o n n o t c l e a r l y demarkea f r o a the g e n e r a l 3 A. independeacls ebbater, l a t e r a l view c o n v e x i t y o f the s h e l l . ( A f t e r Shlmer and Shrocx p i . 120, f i g . 69) P l i c a t i o n s i n c r e a s e by b i f u r c a t i o n s on t h e 4 A. lndependencle sebeter, l a t e r a l T i e * oody o f t h e p e d i c l e v a l v e , by b i f u r c a t i o n and of a h e l l w i t h l a m e l l a e r e s t o r e d . ( A l t e r Plications Fenton and f e n t o n , 1935, p. 377, f i g . l.A.) i m p l a n t a t i o n on t h a t o f t h e b r a c h i a l . o f v a l v e e o f f i g u r e a eyntype same i n s l s e a t A t r y p a exposes Webster, 1921, AB. Midland comparable d i s t a n c e a f r o a tbe beaks. Great v a r B a t . , v o l . 7, p. 1 5 . — A . l n d e p e n d e n c l e fbbater, f e n t o n and Fenton, 1935, Jour. Paleon- i a t i o n s i n a l t e o f p l i c a t i o n e among the many specimens a t hand. On b o t h v a l v e s , l a m e l l a e tology, vol. 9., p.377. e x t e n d outwards from s t r u c t u r e s u s u a l l y c o n s i d e r e d growth l i n e s ; l a m e l l a e have tbe same t y p e D e s c r i p t i o n : S h e l l s l a r g e ; mature specimens o f p l i c a t i o n and apoearance a s the body o f t h e aubquadrate, u s u a l l y elder than l o n g even when s h e l l e x c e p t t h a t 'growth l i n e s " a r e l a c k i n g . l a c k i n g the l a m e l l a r extensions," young speOn b r a c h i a l v a l v e e the l a m e l l a e a p p a r e n t l y were cimens l o n g e r than a i d e . Dimensions o f one o f more c o n s e r v a t i v e than on p e d i c l e v a l v e s , and •abater'a syntypee; length of p e d i c l e v a l v e In most c a s e s n o t w e l l p r e s e r v e d . Variation 37 a a . ^ l e n g t h o f b r a c h i a l v a l v e . 35 a s , ; i n s p a c i n g ana prominence o f g r o w t h l a m e l l a e maximum w i d t h , 37.7 mm.; t t l c i t n e e a a t the are w e l l snown by t n e i l l u s t r a t i o n s ; or. b r a c a l a l e n g t h 20.3. h i a l v a l v e e these l a m e l l a e a r e commonly 5 t o 7 mm. apart.  114  •XS&UBIgKSS  iJiVuiUai. .jiafidUw-Vaa,  aaitfs-a  *jrm a n d l o c a l i t y t Upper aarvonlon. ilmeeton* member o r d e r r a r s e n f o r m a t i o n , .aontbne. iJlarfram:  *THYJ/A a ?"UJHEi;n» M i l l a r (1664) L a i r d , l . i : . , J o u r n . j a l e o o . , 7 o l . a, H E ?  Aims i^r%raTA9BrAr  *»ii*r  S  aorlutlon: S h e l l p m b l l , p u ' o c i r c u l a r to n e a r l y rouler In outline, " l i g h t l y l o n g e r then a i d * • 1 t h an average l e n g t h o f 1£ mm. f o r f i v e a a l l o r * n e r v e d Piieolnanw rsnr-lng from 11 t o 14 mow t h e a v e r a g e width l e 1 1 . 4 mm., runr.lng from 10 to I S mm.  Ihe whe'lw e r e b i c o n v e x alto, o n l y " l i g h t l y e l e v a t e d umbo' on both v a l v e * . Ihe g r e a t e s t thlc»-r.epp ! • I n t b e umbonal r e g i o n and average* 6 . 4 mm. The beev o f the eodlole v a l v e * l l g b t l y o v e r h a n g * the o a r d l n e l a r e a waloh i s V 6 r y e m a i l . 1  Ihe o u rf a c e o r both v a l v e * i o c o v e r e d w i t h 60-70 r a d i a t i n g * t r l n t l o n * which b i r a r e a t e t o ward the a n t e r i o r margin o f the v a l v e . Indistinct growth l i n e * c o n c e n t r i c w i t h t i e a c t a r l o r edge a r e e l e o pre pent, a v e r y l n d i a t l n o t medial B l e u * l a p re pet.t on the v e n t r a l v t l v e w i t h a n eppowlng m e d i a l f o l d on the d o r w a l v a l v e . BernardP: 1'rilr rorm 1* v e r y d l e t l n c t from a j j g r g o , montepenPl * ' ' i c d l e a a i c a 1 P round a t a rimlToi" • t r a t l g r o p h l c h o r i z o n . T . i i * rorr, h b * w t r i a t l o n s and an i n d i s t i n c t r o l d ar.d wiiiuw whereap g j j g j a , m o n t a n e n P l P h n P coar*e c o P t L o and a d i r t 1 r x V m e d i a l r o l d ar.d wlnu*.  i ' i g . 1 br.a 'c - e e r e a i view * i g . £ unci 4 • V e n t r a l v l e a  115  8CUTirOHMl8  1-3  UPPER  flEVOIUAs  A t r y p a acutlformlB S t a i n b r o o k , P e d i c l e , b r a c h i a l , and a n t e r i o r vlewe o f tbe h o l e t y p e , ( a f t e r S t a i n b r o o k , 1938, p i . 3 1 , f i g s . 16, 19, 20. )  O e a c r l p t l o n : S h e l l above ate dims e l s e , eubeq u a l l y biconvex; with n e a r l y s t r a i g h t poete r i o r m a r g i n s , a b r u p t l y rounded a n g l e e and b r o a d l y c u r v e d a n t e r o l a t e r a l margins; w i d e r than l o n g , b r o a d e a t p o e t e r i o r t o the m l d l e n g t h , a t r o n g l y s i n u o u s a l o n g the f r o n t margin. LUmena l o n a of the b o l o t y p e : l e n g t h , 28.3 ma., width, 29.9 mm., t h i c k n e s s , 15.9 am. P e d i c l e v a l v e a t r o n g l y arched from beak t o f r o n t a l o n g the m i d l i n e , g e n t l y arched t r a n s v e r s e l y a t the m l d l e n g t h ; a l i t t l e e l e v a t e d i n the umbonal r e g i o n , d e p r e s s e d on e i t h e r e l d s o f i t and f l a t t e n e d toward the c a r d i n a l a n g l e e . A b r o a d s h a l l o w s i n u s , g e n t l y concave a t t h e b o t tom and I n d i s t i n c t l y d e f i n e d a t the a i d e s , o r i g i n a t e s a t the m l d l e n g t h and, w i o e n l n g and deepe n i n g toward the f r o n t , forma there a b r o a d l y rounded l i n g u a l e x t e n s i o n . Beak s m a l l , p o i n t e d , I n c u r v i n g over the o p p o s i t e beak and p i e r c e d a t tbe apex by a s m a l l c i r c u l a r foramen. B r a c h i a l v a l v e moderately arched a l o n g the h l n g e l l n e , w i t h the c u r v a t u r e g r e a t e s t i n the u x b o n a l r e g i o n , a t r o n g l y arched t r a n s v e r s e l y ; the e u r f a c e e l e v a t e d and g e n t l y f l a t t e n e d a l o n g  BHACHIOPOLIA  ATRYPA  the s u r f a c e e l e v a t e a and g e n t l y f l a t t e n e d a l o n g the m i d l i n e , e l o p i n g a b r u p t l y thence to the l a t e r a l margins, a l i t t l e f l a t t e n e d near tbe c a r d i n a l a n g l e s . Beak e m a i l , e l l g h t l y p r o j e c t i n g , and c o n c e a l e d by t h a t of the p e d i c l e v a l v e . E x t e r i o r o f both v a l v e s marked by numerous, f i n e r a d i a t i n g c o s t a e , r e g u l a r i n appearance, i n c r e a s i n g by I n t e r c a l a t i o n and d l v l a l o n , ana s e p a r a t e d by spaces o f e q u a l w i d t h . About f i v e c o s t a e occupy the space of t h r e e m i l l i m e t e r s a t the f r o n t m a r g i n . Growth l i n e s w i d e l y spaced i n the p o s t e r i o r p o r t i o n o f the s h e l l , more numerous ana c l o s e r t o g e t h e r a n t e r i o r l y , and o c c a s l o n a l y so s t r o n g l y l a m e l l o s e as to l n t e r r u n t the c o n t i n u i t y of the c o s t a e . Resembles A t r y p a l n d e p e n d e n a l a i n shape and appearance but averages s m a l l e r anu has f i n e r c o s t a e . A. i n d e p e n d e n a l a aver age 8 about t h r e e COBtae i n the apace of three m i l l i m e t e r s a t the ant e r i o r margin.  116. Genus GRUErJEvfALDTIA Tschernyschew 1 8 8 5 , n .  gen.  I n H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , V o l . V I I I , p t .  2, p. 175  " T h i s name has been proposed f o r the s p e c i e s T e r e b r a t u l a latilinguis, Schnur, o r i g i n a l l y d e s c r i b e d from t h e m i d d l e D e v o n i a n a& G e r o l s t e i n . T h i s s p e c i e s was c o n s i d e r e d b y K a y s e r as a v a r i e t y of Atrypa r e t i c u l a r i s . The R u s s i a n specimens have t h e p e d i c l e - v a l v e v e r y convex, the r e l a t i v e c o n v e x i t y of the v a l v e i n A . r e t i c u l a r i s b e i n g r e v e r s e d i n t h i s s p e c i e s . From t h e d e s c r i p t i o n and f i g u r e s g i v e n b y Tschernyschew, t h e s p i r a l cones have t h e i r b a s e s l y i n g a g a i n s t t h e l a t e r a l s l o p e s o f t h e p e d i c l e - v a l v e , and t h u s the o u t e r f a c e o f the cones i s p a r a l l e l t o , and j u s t w i t h i n t h e s u r f a c e o f t h e b r a c h i a l valve. I t i s such a m o d i f i c a t i o n o f t h e b r a c h i a l a p p a r a t u s as must n e c e s s a r i l y ensue from the v a r i a t i o n i n t h e c o n t o u r o f t h e s h e l l . The c h a r a c t e r o f t h e l o o p has n o t been d e t e r m i n e d . n  Genotype:  T e r e b r a t u l a Ha t i l i n g u i s  117. S u p e r f a m i l y S p i r i f e r a c e a ( S h r o c k and T w e n h o f e l , p . 330). " S p i r i f e r i d s , o r s p i r i f e r s as t h e y are most commonly c a l l e d , are t y p i c a l l y t r a n s v e r s e s h e l l s h a v i n g c a l c a r e o u s s p i r a l i a o f t h e s p i r i f e r o i d type. The i n t e r a r e a s are commonly w e l l d e v e l o p e d , and t h e d e l t h y r i u m i s m o d i f i e d b y a d e l t i d i u m o r by d e l t i d i a l p l a t e s . The s h e l l may be smooth, c o s t e l l a t e or c o s t a t e , and i n many genera i t i s a l s o p l i c a t e and s u l c a t e . Ranges  Ordovician to T r i a s s i c .  Genera D e s c r i b e d s I.  Ranges  Genus A m b o c o e l i a H a l l  Devonian t o M i s s i s s i p p i a n  I I . Genus A m b o t h y r i s George I I I . Genus A t h y r i s McCoy  Middle Devonian t o M i s s i s s i p p i a n  IV. Genus C h o r i s t i t e s F i s c h e r V. Genus C r u r i t h y r i s George VI. Genus C y r t i a Dalman  Middle  Silurian  V I I . Genus C y r t i n a D a v i d s o n V I I I . Genus C y r t i o p s i s  :  Grabau  IX. Genus C y r t o s p i r i f e r N a l i v k i n  Upper D e v o n i a n  X. Genus Sleutherokomma C r i c k m a y XI. Genus E l y t h a F r e d e r i c k s  Devoniai  X I I . Genus M a r t i n i a X I I I . Genus M a r t i o p s i s Waagen XIV. Genus M e r i s t e l l a H a l l  M i d d l e Devonian Upper S i l u r i a n t o M i d d l e Devonian  XV. Genus P l a t y r a c h e l l a F e n t o n and F e n t o n XVI. Genus R e t i c u l a r i a XVII. Genus S p i r i f e r JVIII. Genus T e n t i c o s p i r i f e r T i e n XIX. Genus T y l o t h y r i s N o r t h XX. Genus W a r r e n e l l a  Crickmay.  118. Reported occurrences of t h i s superfamily i n l i t e r a t u r e reviewed i n Part I of t h i s t h e s i s . I . Genus A m b o c o e l i a  H a l l . 9, 2li.  * A. meristoides.  37.  I I . Genus A m b o t h y r i s George A» h a l l i B r a n s o n .  37.  I I I . Genus A t h y r i s McCoy *  A. angelica H a l l . ;  2 , 9 , 1 8 , 1 9 , 2 0 , 2 1 , 2 2 , 26, 2 9 , 3 1 , 3U.  *  A. angelicoides Herriam.  32, 36.  A. brandonensis  Stainbrook.  37.  A. buffaloensis  Stainbrook.  3h>  A. fultonensis  SwaL l o w .  A . parvula Whiteaves. A. v i t t a t a Stainbrook.  22. 2,  36.  3l+, 37«  I V . Genus C h o r i s t i t e s F i s c h e r C. p r o t i s t u s  Crickmay.  39«  C. g l e n n f o x i C r i c k m a y .  39.  V . Genus C r u r i t h y r i s George C . y o u n g s t o r m e n s i s C r i c k m a y . 39. V I . Genus C y r t i a C . c y r t i n i f o r m i s H a l l and W h i t f i e l d , C . rockymontana W a r r e n .  20, 2 2 .  C. stanleyensis  36.  k-  it Shimer.  V I I . Genus C y r t i n a D a v i d s o n .  8, 1 1 , 12, 21, 36, 37.  * C . b i l l i n g s i Meek. 1, 19, 26, 30, 37. * * glabra Kindle. 7, 37. c  C. hamiltonensis H a l l .  2 , 8, 26, 3 3 , 3U.  V I I . Genus C y r t i n a D a v i d s o n ( C o n t i n u e d ) C. h e t e r o c l i t a Davidson. * C. i n u l a t a H a l l (?) * C . panda Meek.  37.  38.  1, 3, h» 33, 3$, 38.  * C . rockymountana W a r r e n . C. t r i q u e t r a H a l l . VIII.  37.  Genus C y r t i o p s i s Grabau C. nehannieniensis Crickmay. C. minetes Crickmay.  39.  C. h i r a e t h l y n a e Crickmay.  39*  C. n o r m a n d v i l l a n a C r i c k m a y . C. prepta Crickmay.  39.  39.  I X . Genus C y r t o s p i r i f e r N a l i v k i n .  35.  C. alexandrae Crickmay.  39.  C. a n i m a s e n s i s G i r t y .  32.  C. c n a r i t o p e s C r i c k m a y . C. g l a u c u s C r i c k m a y .  39•  39.  C . k e n n e c o t t i . Meek.  1, 30.  C. p l i c a t u s Stainbrook. C. portae Merriam.  37*  32.  C. t h a l a t t o d o x a Crickmay. * , C . whitneyi Hall.  39.  30, 31, 33, 37, 38.  X . Genus Eleutherokomma C r i c k m a y * E . b e a r d i Crickmay.  37.  * E . hamiHtoni Crickmay. * E. killeri  39.  Crickmay.  37. 37.  * E . leducensis Crickmay.  37.  120. X . Genus Eleutherokomma C r i c k m a y ( C o n t i n u e d ) E . r a y m o n d i Haynes. *  37«  E . r e i d f o r d i Crickmay.  37.  X I . Genus E l y t h a F r e d r i c k s " 1,  E . compacta Meek.  15, 37.  E . " u n d i f e r a " Roemer. 9, 21,  X I I . Genus M a r t i n i a  1,  *  M . f r a n k 3 . i n i Meek.  *  M. k i r k i Merriam.  3l+,  *  M . maia B i l l i n g s .  21*.  29, 31, 30,  35,  36.  37.  37.  M. n e v a d e n s i s W a l c o t t .  33.  M. o c c i d e n t a l i s Merriam.  *  37«  3,  3h*  M . r i c h a r d s o n i Meek.  1,  8, 2 i i , 3k, 37.  M . a u b l i n e a t a Meek.  1, 8, 30,  3k, 37.  X I I I . Genus M a r t i n o p s i s Waagen 33.  M . s u b l i n e a t a Meek. X I V . Genus M e r i s t e l l a H a l l .  32.  X V . Genus P l a t y r a c h e l l a F e n t o n and F e n t o n .  36.  P . c y r t i n a f o r m i s H a l l and W h i t f i e l d .  21,  37.  X V I . Genus R e t i c u l a r i a 13,  ( P . f i m b r i a t a Meek.  2li.  8, 21,  X V I I . Genus S p i r i f e r * S . a l l a n i Warren.  30,  S . animanensis G i r t y .  - Elytha fimbriate) 2k, 29, 3U, 35, 36,  37.  37. 6, 18,  19,  21,  29,  36.  * S. a r g e n t a r u s (  S.' compactus  see E l y t h a  * S . d i s g u n c t u s Sowerby.  compactas) 2, 5, 9, 10,  12,  l i t , 25, 2 9 ,  37.  121. X V I I . Germs S p i r i f e r  (Continued)  -S.davisi Williams.  111.  * S. e n g e l m a n i . S. e u r y t e i n e s  28. Owen.  3h, 37.  S. eudonus C r i c k m a y .  39-  S. g a l l a t i e n s i s Haynes. * S. g l a b r a W h i t e a v e s . S. f i m b r i a t a  2.  Meek.  S. h u n g e r f o r d i  18.  21*. 36.  Hall.  ( S. i n u t i l d s H a l l see T y l o t h y r i s i n u t i l i s ) 5. jasperensis ¥ a r r e n .  22, 2 8 , 33, 36, 38.  S . macronatus C o n r a d .  33.  ( S. m e r i s t o i d e s see A m b o c o e l i a m e r i s t o i d e s * S. n o t a b i l i s K i n d l e .  6.  * S. r i c h a r d o n s i . Whiteaves.. * S. raymondi Haynes.  2.  1 6 , 2 8 , 33, 3 6 .  S. s u b a t t e n u a t a H a l l .  2.  S. o r s t e s H a l l and W h i t f i e l d . S. parryanus H a l l .  )  32.  29.  * S. p i n y o n e n s i s W a r r e n . 2 8 . * 5. s t r i g o s u s Meek. S. t u l l i a H a l l . * S. w h i t n e y i H a l l .  37, 38. 2, 1 3 , l l * , 2 6 . 9, 10, 1 8 , 19, 20, 21, 22, 27, 2 9 , 3 6 .  S. z a n t e d e s h i i C r i c k m a y . X 7 I I I . Genus T e n t i c o s p i r i f e r T i e n . * T. cyrtinaformis. T. k e l e t i c u s Crickmay.  39*  35. 32. 39*  X I X . Genus T y i o t h y r i s N o r t h .  33.  T, i n u t i l i s H a l l .  2,  XX  Genus W a r r e n e l l a C r i c k m a y * W. a d o d e c t a C r i c k m a y  37.  4  A #  4i  #  * W. e c l e c t e a C r i c k m a y . 4 l .  125. Genus AMBOCQS L I A H a l l i 8 6 0 , n . gen. I n H a l l and C l a r k e , N a t . H i s t , o f New Y o r k , V o l . . V I I I , p t . 2 , p . 5U. "Diagnosis: S h e l l s s m a l l , concave-, or plano-convex. M a r g i n a l o u t l i n e n e a r l y s e m i c i r c u l a r . H i n g e - l i n e l o n g and s t r a i g h t , i t s l e n g t h n e a r l y or q u i t e e q u a l i n g the g r e a t e s t t r a i s v e r s e diameter of the shell. Pedicle-valve greatly elevated; umbo arched and i n c u r v e d ; w i t h a narrow median groove w h i c h becomes f a i n t e r o r d i s a p p e a r s towards t h e a n t e r i o r m a r g i n . C a r d i n a l a r e a w e l l d e f i n e d and a r c h e d ; divided m e d i a l l y b y an open d e l t h y r i u m , whose l a t e r a l margins b e a r i n c o m p l e t e d e l t i d i a l plates. Teeth p r i m i n e n t , e r e c t , s t r o n g l y r e c u r v e d at t h e t i p s ; not supported by d e n t a l p l a t e s . Muscular area q u i t e r e s t r i c t e d , c o n s i s t i n g o f n a r r o w , e l o n g a t e d i d u c t o r s , e n c l o s i n g an a l m o s t l i n e a r a d d u c t o r . The e n t i r e a r e a i s sometimes d i v i d e d b y a f a i n t median r i d g e . The i n t e r i o r s u r f a c e about t h e m u s c u l a r a r e a i s s t r o n g l y p i t t e d . B r a c h i a l v a l v e convex a t t h e b e a k , becoming d e p r e s s e d o v e r the p a l l i a l r e g i o n and r e f l e x e d n e a r the m a r g i n . C a r d i n a l a r e a c o m p a r a t i v e l y b r o a d and s t a n d i n g a t n e a r l y r i g h t a n g l e s t o t h e a r e a o f t h e o p p o s i t e v a l v e . D e l t h y r i u m open, t h e d e l t i d i a l c o v e r i n g a t t a i n i n g t h e same degree o f development as i n t h e p e d i c l e - v a l v e . C a r d i n a l p r o c e s s narrow and much e l o n g a t e d , r e s t i n g on t h e b o t t o m o f t h e v a l v e e x c e p t at i t s p o s t e r i o r extremity which i s simply b i f u r c a t e d . Crural plates erect, p a r a l l e l ; t a k i n g t h e i r o r i g i n i n t h e d e l t i d i a l p l a t e s and e x t e n d i n g about onef o u r t h t h e d i s t a n c e a c r o s s t h e v a l v e . The s p i r a l s a r e a t t a c h e d b y l o n g c r u r a , t h e r i b b o n making a few v o l u t i o n s o n l y , t h u s f o r m i n g l o o s e c o i l s d i r e c t e d l a t e r a l l y . The l o o p has a p p a r e n t l y the same i n c i p i e n t c o n d i t i o n o f development as i n S p i r i f e r According t o C E h l e r t , the s p i r a l r i b b o n b e a r s s p i n u l e s on i t s o u t e r m a r g i n s . M u s c u l a r i m p r e s s i o n s a n t e r i o r and composed o f f o u r w e l l d e f i n e d a d d u c t o r s c a r s . S u r f a c e smooth or w i t h f i n e c o n c e n t r i c s t r i a e c r o s s e d b y i n d i s t i n c t r a d i a t i n g l i n e s ; r a r e l y s p i n o u s . S h e l l substance f i b r o u s , impunctate. " Genotypes  O r t h i s umbonata, C o n r a d .  Hamilton group.  124  MOilSTCrDSS  aMBOCOSLI/l Hartlaie Spirifer without a trass of a msalal f a l l , though the lnasdiate oargla et the middle of the froat Is very slightly r»lsed to glee rooa far an obscure projection of that of the narrow and curved. Ventral valve gibbous, sexartlaes rathar strongly so, without s mesial sinust beak prooiaesi, Incurved, In ventrlcoss specimens Sonet less alojDst folded lows, upon the other so as to close end hide the foramen; ares very small and obscure, often nearly obsolete; foramen triangular, rrther higher than wide, aad sot closed by a pawtdo-deltidium. Surface marked by fine, nther ohscur- concentric striae, with e fan rather stron - concentric rld/es of growth, usually phasing over ths middle of the ventral valve, and between that and the front. Internal o a t shearLig distinct radiating ivrklngo. Internal spires rather large, and consisting (la e aaall specimen) of about six turns. Socket plates of duroal valve thin, prealnent, approximate, end but allghtly diverging ferwerd.  OrrVJl DSTOlIiUI aRACKIarttfA  iewsgth of a awrtsro spec: , 0.73 inch; breadth. 0.65 inch; convexity, G.b7 inch.  smirn ituarmw, HSEMTOPP >*e* (i860) Trans. Qllc.eead. Sci. Vol. 1, l*>7-«, F> 106. SPJHIPEH  t m r r m i i )  HJISTOIMS  Hsek  Shall varying froa longitudinally subeval to auborblrular, helm; saastiase longer then aide, end in other easnplee slightly alder than laig, gonar.il ly rather ventrlcoss In adult spaclaensi hinge line very short and passing so gndually into the regularly rounded lateral marylua as acarcely to appc.T straight at a l l ; frunt narrowly, or more or lass regularly rounded. Dorsal valve convex, but lass so than the other.  andaisau and Loekhsrt rivers, 1st. 67 dsg. • nin. S., long. 126 dag. V.  1. 2. 3. U.  Dcrss.'. view Ventral view Side view Anterior view  125.  Genus ATHYRIS McCoy 18ILU, n. gen. In Hall and Clarke, Nat. Hist, of New York, Vol. VIII, pt. 2, p. 83 "Diagnosis: Shells subequally biconvex; outline transversely e l l i p t i c a l , subcircular or elongate-subovatej surface medially sinuate. In the pedicle-valve the beak i s inconspicuous and incurved, usually concealing the foramen and deltidial plates; frequently, however, the former i s exposed. Cardinal slopes not well defined i n the typical group. The convexity of the valve i s greatest i n the umbonal region, the surface sloping evenly to the sides, and becoming depressed on the median line into a sinus, which i s most conspicuous on the anterior margin. Beak of the brachial valve not prominent; a median fold corresponds in strength to the sinus of the opposite valve. In the interior of the pedicle-valve the d e l t i d i a l plates are usually absent; the teeth are prominent, recurved at the tips, and supported by stout dental lamellae, which are not produced anteriorly about the muscular area. Between them l i e s a deep, transversely striated pediclecavity, and in front of this an ovate muscular scar extending about one-half the length of the valve and divided into flab'ellate diductors (which are frequently very indistinct) and narrow, cordate adductors. The p a l l i a l region i s covered with ovarian pittings and branching sinuses. In the brachial valve the dental sockets are broad and deep. The hinge-plate varies considerably i n form; in the •typical division of the genus i t i s subtriangular in outline, and supported by stout crural plates. The median portion i s f l a t or concave, the lateral margins thickened and elevated. At the apex of the plate and just within the beak of the valve i s a circular perforation (visceral foramen), which i s continued beneath the plate into the cavity of the valve. The anterior margin of the plate i s straight or slightly concave, occasionally trilobate, and the crura are attached at the extremities of the lateral ridges. Sometimes the outline of the hinge-plate i s rendered subquadrate by the development of two post-lateral expansions. The brachidium consists of spiral cones lying base to base, with their apices directed laterally. The form of these cones varies with that of the internal cavity, but as a rule they are much compressed vertically, the posterior curvature being short and convex, while the anterior curve i s long and sometimes depressed. The crura originate from the hinge-plate at a large angle, are long and convergent; the primary lamellae arising from their extremities, make an angular curve at their origin, thence, in the typical species, curving deeply upward and backward, to form the f i r s t volution. The spirals are connected by a loop, which takes i t s origin on the f i r s t half of theprimary lamellae, the two lateral lamellae converging, and uniting at about half the distance across the base of the cones, to form a broad saddle with a convex upper surface; the anterior extremity of this saddle may be simple or divided; i t s posterior  126. p o r t i o n i s n a r r o w e d , i n c l i n e d downward o r toward t h e beak o f the b r a c h i a l v a l v e f o r a s h o r t d i s t a n c e , thence i t r i s e s a b r u p t l y t o w a r d t h e umbo o f t h e p e d i c l e - v a l v e , and b i f u r c a t e s n e a r t h e e x t r e m i t i e s o f t h e c r u r a , each b r a n c h f o l l o w i n g t h e c u r v a t u r e o f t h e p r i m a r y l a m e l l a e and c o n t i n u i n g f o r o n l y a p a r t o f t h e d i s t a n c e between the ends o f the c r u r a and t h e o r i g i n o f t h e loop. These a c c e s s o r y l a m e l l a e v a r y somewhat i n f o r m , a r e n a r r o w e r t h a n t h e r i b b o n o f t h e c o i l , and l i e between t h e p r i m a r y , and t h e f i r s t band o f the secondary l a m e l l a e . The m u s c u l a r a r e a c o n s i s t s o f a l o n g , o v a t e s c a r , w h i c h i s d i v i d e d i n t o a subquadrate p o s t e r i o r p a i r , and a s u b c o r d a t e a n t e r i o r p a i r o f a d d u c t o r i m p r e s s i o n s . These a r e s e p a r a t e d l o n g i t u d i n a l l y b y a v e r y f a i n t median r i d g e . . On c a s t s o f t h e i n t e r i o r t h e f i l l i n g o f t h e v i s c e r a l foramen i n t h e h i n g e - p l a t e f r e q u e n t l y shows a c r o s s - s t r i a t i o n l i k e t h a t o f t h e p e d i c l e - c a v i t y o f the o p p o s i t e v a l v e , and a l s o i n d i c a t e s t h a t t h e median r i d g e i s c o n t i n u e d t h r o u g h o u t the e x t e n t o f t h i s p a s s a g e . The s u r f a c e o f the v a l v e s i s v a r i o u s l y ornamented; i n the t y p i c a l g r o u p , a t each c o n c e n t r i c g r o w t h - l i n e , t h e r e i s a b r o a d l a m e l l a r e x p a n s i o n ; i n some c a s e s t h i s e x p a n s i o n i s s t r i a t e d l o n g i t u d i n a l l y , o r i t may be d i v i d e d i n t o f l a t s p i n e s , w h i c h merge i n t o t h e l a m e l l a a t t h e i r bases; a g a i n t h e s p i n e s may be l o n g and t u b u l a r , b u t c o n n e c t e d b y t h e l a m i n a r e x p a n s i o n s . The s u r f a c e j f r e q u e n t l y appears t o be smooth, or c o v e r e d o n l y w i t h c o n c e n t r i c s t r i a e , and i n one o f t h e l a r g e s t subd i v i s i o n s o f t h e genus ( S e m l n u l a ) t h i s i s a normal c o n d i t i o n , w h i l e i n other d i v i s i o n s i t i s often a l t o g e t h e r c a s u a l . Shell-substance fibrous, Genotype:  impunctate.  Terebratula c o n c e n t r i c a , von Buch.  Middle Devonian.  127 "??3>. 2I7CMIA:! BVCHICPODJI  A l i i  #  ATVTBI3 A.r)gLlCA (Hell 1861) Hall »n, M-.rl-a 18«3, Pal, \.T. Stata, pt. 2, p. 90, p i . h$, f i g s . 26-JO. /ITHTRIS A' igf.T:.' p»acrt|.'.loni 3M11 13-25 n i . a l i a , rjbpanta_'<ina? in o.tTlnaj a-Je.ta leejv, fold yroailnent on anterior half o f valve. Surface «*r*ei by reguli.r fine i-i nrai.trle laeallee. U e a l i t r aaj Horlscni ','ppar Devonian of tha «ppai mrtnrmr^TrT'm I .'lavada.  AHGEUCOIuIS  1  UPPlr. JEVOHIAH BKAOHIOPODA  ^ •  # 3  A t h y r t a e n g o l i c o l d e a Iter n a n 1940, 1 - i a n t e r i o r , v e n t r a l ana u n r e a l vlewe o l p a r a t y p e e , e l l g h l l y reuuctu. ATHYKIB AaGLUCOlJEB A t h / r l a a n w e l l c o l d e s I t e r r l e a ( l f t 4 0 ) G e o l . Soc. Aaer. , Soec. Pep 2b, p. o4, p i . 10, f i g s . 1,2,4. O e e c r i p t l o n . — Averege s h e l l e l s e a a a l l i v a r y l n g f r o a treneveree t o narrow; b i c o n v e x , w i t h c o n v e x i t y o f a o r a a l anu v e n t r a l v a l v e about e q u a l i e u l c u e ana d o r a a l f o l u e e l l developed; coaaieaure paraeulcatej r e d t a l ornaaentation abaent; c o n c e n t r i c l n c r e a e n t e l l l n e a nuaeroue end c l o e e l y apeced. A t h y r l e e n g e l U o i u e a d l i f e r a f r o a the l e e Yor« A. angel l e a In i t a g e n e r a l l y a a a l l T e l s e , g r e a t e r v e a t t i c o e i t y o l many i n d i v i d u a l s , and f r e q u e n t l y aore o r o f o u n u d e v e l o n a e n t of the l e t e r a l s u l c a t i o n on e i t h e r e l d e o f tbe d o r e a l told. Ueaaureaente H o l o t y p e , w i d t h 14.4 a a . , l e n g t h 14.2 a a . , t h t c i n e e * l b . 7 a a . Occurrence.-- Upper U e v l l e Gate f o r m a t i o n , C y r t o a p i r l f e r lone: i n aeaoclation with Cyrtot p l r l f i r p o r t e r . S c h l x o p h o r i a a l a p e o n l . and Leiorhyiichue a a l c o t t l .  ATHYRI3  128. Genus CYRTINA Davidson, n. gen. Davidson (1858), Monograph of British Carboniferous Brachiopoda, Pt. V, p. 66. Sub Genus Cyrtia Dalman (1827) and Cyrtina Davidson (1858). "In the eighty third page of my general introduction, doubts were expressed as to the value of Dalman's Cyrtia and his diagnosis i s there stated to be unsatisfactory and equally applicable to several species of Spirifer. In fact the genus appears to have been created simply to receive those few species of Spirifer which possess a circular foreamen in the deltidium of the larger valve, for the author did not furnish any information regardingthe internal arrangements of his two named types C. exporrecta and C. trapezoidalis. Subsequently to 1827 several other species were added (by different authors) to the genus Cyrtia and amongst these are some whose shell structure has been stated to be punctate, while that of Dalman's type i s unpunctate, as in Spirifer proper, and although i t has always appeared to me probable that a difference in shell structure would be accompanied by some important interior modification, i t was not until very lately that I was enabled to discover some of the characters of the following species. C. exporrecta, C. trapezoidalis, C. Murchisoniana, C. cuspidata, C. heteroclyta, C. Demarlii and C. septosa. The results show that in the f i r s t four, which belong to Dalman's genus, the internal characters are similar, but different from the last three, which cannot be properly retained under the same generic denomination, for i t i s evident that considerable dissimilarities in the arrangements of the plates of the ventral valve must have carried along with them some important difference in the soft part of the animal, and I therefore propose at least provisionally to distinguish the l i t t l e groups of spiriform shells of which C. heteroclyta,C. Demarlii and C. septosa are examples under the generic or sub generic apellation of Cyrtina, and to leave that of Cyrtia to those which agree with Dalman's C. exporrecta, C. trapezoidalis and C. Murchisoniana, etc.; but i t is necessary to observe that the last named genus i s of i t s e l f of such l i t t l e value that i t w i l l remain a question of further discussion whether i t should be retained or added to the synonyms of Sowerby's jpirifer. In Cyrtia a short hinge tooth i s situated on either side of the base of the fissure supported by vertically shelly plates which diverge and extend from the extremity of the beak forming the fissure walls and occupying about one third of the length of the bottom of the valve. There exists in Cyrtia no median plate or septum, the arch-like deltidium which covers the entire fissure i s generally, but not always, perforated by a circular foreamen. In the smaller valve the spiral  129. appendages and their mode of attachment i s exactly similar to what we find in Spirifer and with which the plates in the ventral valve also very closely agree. Therefore Cyrtia (Dalman) presents no other feature by which i t can be separated from Spirifer. proper, than that of i t s deltidium and foreamen, which are characters of hardly sufficient importance to warrant the creation of a separate genus. In Cyrtina the diverging plates already described do not exist, but we find in the interior of the ventral valve (of C. heteroclyta and C. septosa) two contiguous vertical septa which coalesce into one median plate which extends from the extremity of the beak to within a short distance of the frontal margin and then diverges to form the dental plates in a very similar manner to what we perceive in Pentamerus. The fissure i s covered by an arched shaped deltidium, but i n C. Demarlii Mr. Bouchard has remarked that the median septum i s continued as the under surface of the deltidium, and the dental plates are fixed to the sides instead of the upper edge as in C. heteroclyta and C. septosa. The arrangements i n the smaller or more important valve are s t i l l unknown notwithstanding many efforts I have made to pry into their interior: and i t i s certain that no vestage of spiral coils have hitherto been noticed by an author. .Therefore, although we possess no proof that these three species of Cyrtina were possessed of spirals, and consequently true Spiriferidae, i t w i l l be necessary to pause before admitting the shells in question into the Genus Pentamerus." Genotypes:  C- heteroclyta C. Demarlii C. septosa - 7~.'. -<.-. V ~  }  1-Z *  130 DKVCUAN  •tI.HNGSX  high, eleeed below the middle by a eolarately eenvex deltidinn which (in the sneelnen examinee), l l lae|l> aaarglnated eheve by a large ova. aperture with beveled merging, boreal valve elder then long, trunoato-eube.llptioal, much cou.preeeed or nearly f l a t , or a l i t t l e oeneavei front very eli.'htly relaed 'y the ahailow alnua of the opposite valve. Surface orna .e..t«i by about forty rounded »i»i f a i n t l y d e f i e d n d l e t l n g costae on eaeh valve, ter. or eleven or which occupy the vary ilia low mesial alnua of the doraal valve, and about the same nuiiher the corresponding : l l r M ;vo>.leer, •» of the ventral valve. These esatae an ^ t i m i Ufuret'e, or tnora.ee by theintercalation of othera, whioh l i e cut before re> ohInk the heeka, particularly en the a l l e l e portions of the valvee. Feint tr«eee ef vary fine crotated concentric striae, aid a few atrcnger H a s ef ;rowth «ark the valvee l a the oepaolte direct or>| while, with a reed magnifier, minute gtaaalea -ay be seen er. a l l parte of the surface, eafelletoe eurfeeee else ehew, under e magnifier, the minutely punctate structure characteristic ef the genua.  HYHTINA 'ULLl'AiSI Week (1868) Trans. Wile. »cad. S c i . V o l . 1 . P.  n.  CYRTINA  IULLI'MSI  cloak  Uaeoripttmii J h e l l of iedlum a i s a | hinge l i n e less than tha (.tvateat breath, and ohtuaely angular, or scriewhat ro.mted at tha extreaitlee. Ventral valve prominent at the u i * o , f r o m whlok i t slopes ahruptly, with a moderately convex o u t l l w, to the anterior and l a t e r a l marginal provided with a hro.-d, very shallow, undefined iiestal sinus in fronti beak ohtueeiy engular and a l i t t l e curved hackwardai area triangular, soiwwhat longs? or. tha hinge lu.e than on either of angular l.-teri-I margins, s l i g h t l y arched and inclined r->ckwai\is o v e r the hin*e, and showing more or leas distinct transverse -iaris o f ^rowthj foranen very narrow, or less that; h a l f a s wile se  GLABRA  CTVTJNi  WACHIuHUW  Length from the front te the elnge, wu' lne*| t e . from front te point of hea ef ventre! valve, 1.6C LMhi breadth, 0.6C ineh. length ef hinge, t . * lneh| conv.xlty of the two valvee, < .33 Inch, Bfceut fcurf i f t h s o i which l a occupied ny the ventrrl valve aler.e. LocalItyi Clear Water r i v e r , a tributary of athe'aeoe river. Devonian ef the age of the Hamilton »roup. Diagrams!  1. l i e view i* Ventre, view 3. osterlor v u w it. bersa view.  CTRTINA  DEVONIAN BRACHIOPODA  Horlson and Localityi Simpson shale, bank of Hackensle "iver 5 miles above Rabbitekln River, ...Vl.T. CYRTINA OLABRA kindle kindle (1919) Geol. Surv. Canada, Hua. B u l l . ?9, p i . 1, f l g a . 1-3. CYRTINA OLABRA kindle. Descriptioni Shell snail with aubpyramidal pedicle valve. Si lea of ventral valve sloping regularly to the margin with a broad ahailow sinus not renehlng quite to the beak. Rr.ichlal valve convex in the umhtaial and median portion and a l l g h t l y convwx near the anterior and l a t e r a l margins, l u l l tai pedicle valve showing only at front margin of a h e l l . Cardinal area transversely s t r l n t i d and Inclined forward. D e l t i d i a l pl.itu not observed. D e . t i d i a l opening extend big to tho apex. The perfectly smooth surface of thla shell distinguishes i t ron other species of Cyrtina.  Dlagra  1. Doraal view. 2. Poeterior view. 3. Ventral view.  131 J"" " * 1  DEVONIAN BRACHIOrODA  1  CTHTEIA 1WULATA Stainbrook Staliibrook, lyliS, Geol. *ee. Amer., HOB. I i , p. 59, p i . 6, f i g s . 26-29. crura*  CTHTBA.  Brachial nearly f l a t , gently convex centrally, f o l d Strang, originating s t the beak, elevated above remainder of valve, highest at front, gently convex or flattened along suaalt, bordered on each side by s deep furrow; some specimens show a s l i g h t medial depression at the front or posteriorly. Interior unknown. Dingramsi  EnJUTA Stainbrook  Description! Shell s n a i l , eabpyrsnidax in snaps, eubqnsdrate i n outline with rounded entero-lateral margins; having greatest width generally along the hiagel l n e or s l i g h t l y anterior In seas specimens, angles usually extended, and anterior commissure strongly unlpllcate*  1. 2. 3> It.  Ventral view. Dorsal view. Anterior view. Posterior view.  Pedicle valve strongly convex, subpvraaldal In shape, highest l a the umbonal rsgioa slrnost directly posterior to the beaks. Slopes s l i g h t l y curved from back to front and from sulcus to angles. Cardinal area f l a t for tbe greater part, hi;h, and s l i g h t l y to considerably curved near tlie bs.nk.  PASDA  DEVONIAN K1ACKKP0DA  CTHTIKA  and l a t e r a l nargin; beak high, not incurved but sonatinas twisted t o one side; pre* large, welldefined, triangulpr, neprly f l ^ t , or s l i g h t l y arched, and f i n e l y and regularly striated both ways; deltidium narrow, a l i t t l e convex, aid at the upper extremity perforated; mesial sinus very shallow and rounded, csusir. : slight projection intc a corresponding recess In the margin of the other valve i n front. Surface ornamented by 1 0 to 1 2 smell, regular, simple radiating costae on etch side of the .reals! sinu: end f o l d , which l a t t e r are without costae, but marked with very f i n e , obscure radiating ptriee. Pine, obscure lines of growth also mark the entire surfoee concentrically, i n wall preserved spcimana. t  CTRTINA PAHDA Reek (1868) Trans. Chic. Aend. S c i . Vol. 1. p. 1U0. CYHTIHi P«MDA Meek Descriptloni Shell pyramidal, wider than long; hinge l i n e leas than the greatest breadth of the valvea i n adult examples; l p t a r a l extremities obtusely angular or somewhat rounded. Dorsal vulve truncato-subelllptie, nearly f l a t , or but l i t t l e convex; bosk not prominent; mesial fold rounded, ne.-rly f l c t , excepting at the front, where i t l a a l i t t l e raised, ecryping d i s t i n c t l y more than one-third of the entire breadth of the valve at the anterior nargin, but narrowing very abruptly to the nenk. Ventral valve very convex; aidee eloping abruptly frcr. the beck t c the front  "ength, 0 . U 5 inch; breadth, 0 . 6 6 inch; convexity, 0.51 inch. Locality! Onion r i v e r , long. 125 deg. W., l a t . , 67 deg. H. DiiRrsmsi  1. Side view 2 . Ventre! view 3. Dorsal view ii.  Hos:.eritr view.  1 3 2 ROCKTMOHTANA  CfRTINA  DEVONIAN 3RACHI0P0DA  Tha surface of both valvee l e f i n e l y close, oonsletlng of fine concentric nt. Brachial valve gently convex, with a uniformly rounded f o l d appearing at the anterior margin In mature specimens.  CTRTPIA yoggpfjftgu Warren, 1920. Trans.Royai Soo. Canada, 3rd Sar., v o l . 22, p t . l . Sao. b, p. 11», p i . 1, flgs.6-13. CTRTOJA RCICrnOrraU warren acrlptloni Shall a n a l l , axooth subpyraml"l»l In ahapa, subquadrate i n outllna with rounded M l t e r o - l a t e r a l margins] createet aldth anterior to the hinge-line; poetero-loteral aarglna rounled, and anterior eenmdaure unlpllcate. Dimensions; length, 6.8 aa., a l d t h 9.8 an., thickneee, 6.' na.  Remarks• Stainbrook (19U5, p. 59) has suggestsd that the species be referred t o Thomassrl*. Some support to this v i s a i s provided by ths occurrence of an i n d e f i n i t e l y farmed d e l t h y r i a l plats. P i agr anai  1. 2. 3. u.  Ventre: view. Anterior view. Posterior rlsw. Lateral view.  Pedicle valve subpyraaldai, thickset in the umbonal region; surface s l i g h t l y curved, and descends abruptly t o the anterior end l a t e r a l margins. Tbo sulcus originates st ths beak sad paaaee forward into a low rounded l i n g u a l extension. Cardinal area high, f l a t , subperpendicular to the plane of coralsure, and transvsrssly lsivaslose. Dslthyrlun higher than vide.  BTAJIDLTSBBIS  UPPEft JCVOxlAK BRACHIOPODA  CYATIA  h i g h e r than s i d e (base 1/4 h e i g h t ) , bounded by tbe t h l c x e n e d a a r g l n a , o f t h e a t r o n g l y deve l o p e d a e n t a l p l x t e e ; these p l a t e s e x t e n d about h a l f d i s t a n c e t o f r o n t a l margin. Medi a n a l i u s n a x r o a and aaooth a t beax, becoming broad, o l moderate d e p t h , and p l i c a t e d a n t e r iorly; these p l i c a t i o n s e n t e r i n g i n the umbon e l r e g i o n b i f u r c a t e r a p i d l y , r e s u l t i n g i n about 4 0 l o o , rounded p l i c a t i o n s a t the f r o n t o i tbe v a l v e . L a t e r a l e l o p e s o l v a l v e each s i i n about 4 0 low, rounded, a i a p l e p l i c a t i o n * . B r a c h i a l v a l v e much l e s s convex then t h s pedicle, with t h s greatest convexity at tbe C v r t l a ataadlvanala B n l a e r , 1946, G a o l . uabo; c a r d i n a l s x t r s a l t l e s i l s t t s n e d . MedSurvey o f Canada, Hue. B u l l . 4 4 , p i . 1, i a n f o l d low, b r o a d l y rounded, l n c r e a a l n g i n f i g s . 4 a, b, e, d, a ; 1, i s , S, 4 , 6. b r e a d t h r a o i d l y t o a a r a the f r o n t . Plications C a r d i n a l , p e d i c l e , b r a c h i a l , a l d a , and a l a l l a r i n nuaber, c h a r a c t e r , and a l i o t o a n t e r i o r v i s e s o f t h s type specimen. those o f c o r r e s p o n d i n g p o s i t i o n s upon t h e opposite valve. CTH1IA SiASJLTIKBIS Tbe f i n e r e u r f a c e a s r k l n g e c o n s i s t o f m i n ute r a d l e ' l n g , o a p l l l o a e l i n e s , c o v e r i n g t h e CJUJUU a t a n a l r e p a i . Shiaer, 1946. entire s h e l l . L a r g e r than C. c y r t l n l f o r a l s , i n c r e a a e d S h e l l medium s i t e , e u b p y r a a l a a l w i t h g r e a t - nuaber o f p l i c a t i o n s i n t h e s i n u s , and mors e s t c o n v e x i t y a t umbo. H i n g e - l i n e e q u a l s h i g h l y a r c h e d c a r d i n a l a r e a . C y r i l a norwoodi g r s a t s s t aldth, c a r d i n a l e x t r e a l t i e e angular. a a a l l e r I n e l s e , bae narrower d e l t h y r l o r n , Dlawnsioaa o f t n a type s h e l l : length froa narrower aad s h a l l o w e r a e d i a n s i n u s , and fewh l n e t e - l i n e t o f r o n t a l margin, 4 0 a a . , f r o a e r p l l c a t l o a e ( 30-40 i n a t e a d o i 6 0 ) . flplrlier bees Of b r a c h i a l v l v e t o f r o n t a l a a r g l n 41 aa. ailaWtVM,%AeJISt9«Bttv Q l r t y l a b r o a d e r , hee greatest aldth (at hinge-line) 41 aa., thlcxbroeder d e l t h y r i u a , and hae 40-45 p l i c a t l o n a aeas, 1 9 a a . , ot p e d i c l e v a l v e 1 3 a a . , o f upon each l a t a i a l e l o p e and o n l y 5-10 I n the b r s t - h i a l v a l v e 6 aa. , d e l t h y r l u a 6 aa. a i d e alnu*. S p l r l f e r d l a l u n c t u a o c c l d e n t a l l a Whltat baa* and 1 0 aa. h i g h . s a v s s l a d l a t i n c t l y a l a t a w i t h couree n l i c a t l o n a . P e d i c l e valve eubpyraaldal, greateat conO c c u r r e n c e . — I n Upper Devonian a e c t i o n s i n v e x i t y near beax from which the s u r f a c e c u r v e s tha M l n r t w a n x a r e g l o a . a b r u p t l y a u t r r i o r l y and l a t e r a l l y t o the a a r g l n o f the v a l v e , Beak o o l h t e d , very a l l g h t l y i n c u r v e d , nt t i n e a s l i g h t l y t s l a t e d . Cardinal area b r o a d , e x t e n d i n g to tne c a r d i n a l e x t r e a l t i e e , a l u j e t e t r a i g h ; below, more d l e t l n c t l y a r c h e d i n upper h a l f , v e r t i c a l l y s t r i a t e over i t e e n t i r e aree. Delthyrioa conaiderably  155. Genus ELEUTHERQKOMMA Crickmay n . gen. C r i c k m a y ( 1 9 5 0 ) , J o u r . P a l . V o l . 21+, N o . 2 , p p . 2 1 9 - 2 2 5 , p i t s . 36,  37.  • D e s c r i p t i o n : Medium r i d g e d , s u b e q u a l l y b i c o n v e x , s t r o n g l y t r a n s v e r s e and mucronate S p i r i f e r i d a e , w i t h non p l i c a t e f o l d and s u l c u s and c o s t a e ( o r p l i c a t e ) l a t e r a l s l o p e s . H i n g e - l i n e s t r a i g h t and e q u a l t o t h e g r e a t e s t w i d t h o f the v a l v e . V e n t r a l v a l v e w i t h s h o r t i n t e r a r e a , medium b r o a d d e l t h y r i u m and i n c u r v e d beak; i n t e r i o r l y w i t h strong s t r a i g h t dental l a m e l l a e diverging t o w a r d t h e i r b a s e s w i t h l o n g s t r a i g h t h i n g e t e e t h and i n some a s m a l l a d v e n t i l i o u s d e p o s i t o f n a c r e p r o d u c i n g i n some specimens the appearance of a t r a n s v e r s e d e l t h y r i a l p l a t e but n o t a t r u e p l a t e : u s u a l l y possessing a l o w , t h i n , sharp median r i d g e b u t n o t a t r u e septum. D o r s a l v a l v e w i t h v e r y s h o r t i n t e r a r e a and l o w , s h a r p b e a k , i n t e r i o r l y w i t h deep n a r r o w s o c k e t s and s t r o n g o b l i q u e s o c k e t p l a t e s , a s h o r t , broad, rounded, undivided, v e r t i c a l l y s t r i a t e c a r d i n a l process and a l o w median r i d g e b u t n o t a t r u e septum. E x t e r i o r o f l a t e r a l s l o p e s ornamented b y few t o many c o s t a e (or p l i c a e ) ; and c n t h e whole s h e l l c o n c e n t r i c l a m e l l a e . M i c r o ornament o f the whole s h e l l ( e x c e p t the i n t e r a r e a ) f i n e r a d i a l t h r e a d s ( o r s t r i a e ) c r o s s e d b y f i n e r e g u l a r c o n c e n t r i c m i c o - f i l a and i n some i r r e g u l a r l y spaced m i c r o - s p i n e s . D i s t i n c t i o n from most o t h e r M i r i f e r i d genera l i e s i n t h e e x a g g e r a t e d l y t r a n s v e r s e and mucronate c h a r a c t e r . From M u c r o s p i r i f e r as from a l l o t h e r genera i t i s s e p a r a t e d b y i t s complex m i c r o - o r n a m e n t . Genotype:  Eleutherokomma h a m i l t o n i C r i c k m a y .  »  134 Eleutneroxoema b e a x a l Crickmay, 1950, J o u r , ox P a l e o n t o l o g y , v o l . 24, p.443, p i . 37, x l g s . 1-3, 10. D e s c r i p t i o n . — S h e l l eubequally biconvex, outline semicircular, extremities fine aculelform mucronea. L a t e r a l e l o p e s w i t h 9 t o 12 d e l i c a t e rounded c o s t a e , whose s t r e n g t h d e c r e a s e s w i t h d i s t a n c e f r o m f o l d and e u l c u e . Coatee ahow on Internal euriace. v e n t r a l v a l v e a t r o n g l y convex. S u l c u s oounaea by s t r o n g c o e t a e , narrow, unmarxea. Bear strongly incurved. Interarea ahort. Delthyr i u m about 60 ; open, w i t h o u t c a l l u s . Hinge teeth f i n e . Dental l a m e l l a e s t r o n g , d i v e r g i n g p a r a l l e l t o f i r s t f u r r o w , about 1/4 l e n g t h of valve. Doraal valve s l i g h t l y l e e s convex. Fold wider than i n other species, evenly tapered, p r o m i n e n t , f l a t upon the culmen. Beak s l i g h t l y more prominent than i n o t h e r s p e c i e s . Intera r e a v e r y s h o r t . N o t o t h y r i u m not wide; very ehort. C a r d i n a l p r o c e s s rounded, v e r t i c a l l y finely striate. Socket p l a t e s s t r o n g . Incons p i c u o u s I n t e r n a l median r i d g e . i n c e n t r a l r e g i o n of v a l v e . E x t e r i o r covered with f i n e c o n c e n t r i c l a m e l l a e , 3 t o 6 t o the mm. Between each o a l r are 1 - 4 . — E l c utherokqmma b e s r a i C r i c k m a y , 1, 3 or 4 f i n e c o n c e n t r i c m i c r o f i l a . Surface covP a r a t y p e No. 2, from I m p e r i a l P a d d l e R i v e r Bo. 1 b o r e h o l e , at 8090-8110 f e e t d e p t h , m o l d e r e d w i t h f i n e r a d i a l t h r e a d s ( m i c r o - s t r i a e ) , 10 or 12 t o the mm. I n t e r s e c t i o n o f these two of e x t e r i o r of p e d i c l e v a l v e . The p o s t e r i o r f i n e ornaments p r o d u c e s a s h a r p , d e l i c a t e , f i m margin l e I n c o m p l e t e . M a g n i f i e d t o show b r i a t e p a t t e r n , and from s t r o n g e r i n t e r s e c t i o n s , micro-ornament, xlO.O. 2, P a r a t y p e Bo. 1, short, d e l i c a t e micro-spines a r i s e . from same s o u r c e , mold o i p a r t of i n t e r i o r M e a s u r e m e n t s . — H o l o t y p e , w i d t h , 44.5 mm.; of p e d i c l e v a l v e , »lth some a h e l l s u b s t a n c e l e n g t h ( d o r s a l v a l v e ) , 9.5 mm. ( t h e c o r r e s p o n d p r e a e r v l n g the l e f t mucro, X3.0. 3, H o l o ing v e n t r a l v a l v e 10.5 mm.); depth ( d o r s a l type, from same s o u r c e , mold o i e x t e r i o r o i v a l v e ) , 3 mm. b r a c h i a l v a l v e , w i t h eome s h e l l substance O c c u r r e n c e . — I n f i n e d a r k l i m e s t o n e aone bea t i l l i n piece. The d o r s a l p a r l n t r o p e and low the b l a c k s h a l e , i n I m p e r i a l P a d d l e R i v e r the e x c e a s l v a l y f i n e mucronea have been l o s t Bo. 1 b o r e h o l e , at d e p t h B090 t o 6110 f e e t . i n b r e a x i n g the m a t r i x . M a g r . i f l e a to show micro-ornament, x6.o: 4, P a r a t y p e No.3, a A g e . — L a t e r than E. l c d u C o a e l e and S. k l l l e r i . e m a i l p o r t i o n o i the s u r f a c e more n l g h l y below b l a c k s h a l e zone c a r r y i n g T e n t a c u l l t e s sp.. m a g n i f i e d to show micro-ornament, x20.0. M a n t l c o c e r a a c f s i m u l a t o r H a l l , B a c t r l t e e ap. HAMILTONI  UPPEH DEVONIAN BKAOHIOPODA  1-3, g l a i i t h » r n i r « m m . h a m l l t o n l Crickmay, 1, H o l o t y p e , from La S a l i n e ROCK, p e d i c l e valve, e x t e r n a l aspect. L e t t mucro f u l l y p r e e e r e v e a , r i g h t b r o k e n o f f a t l e s e than m i d - l e n g t h , x l . 8 . 2, P a r a t y p e B o . l , from La S a l i n e ROOK, b r a c h i a l v a l v e , e x t e r n a l a e p e c t . Both mucronea broken o f x ; impress i o n o f r i g h t mucro l e p r e s e r v e d f o r about 7/6 o f l t e f u l l l e n g t h . X 4 . 0 . 3, P a r a t y p e Bo. 2, f r o a La S a l i n e ROCK, p e d i c l e v a l v e , e x t e r n a l a e p e c t , m a g n i f i e d to ahow m i c r o ornament, X 5 . 0 . ELEUTHEHOEOMMA HAMILTOHI Eleutherokomnia h a m l l t o n l Crickmay, 1950, J o u r . P a l e o n t o l o g y , v o l . 24, p.440, p i . 3 6 , f l g a . 1-3. D e s c r i p t i o n . — S h a l l somewhat e m a l l e r than o t h e r s p e c i e s , e u b e q u a l l y b i c o n v e x , approxi m a t e l y s e m i c i r c u l a r i n o u t l i n e , each e x t r e m i t y produced s h a r p l y i n t o a v e r y l o n g , e l e n d e r , n e e d l e - l i k e mucro. L a t e r a l s l o p e s w i t h e i g h t to t e n rounqeu coetae and narrower  ELKUTHEROKOMMA  f u r r o w s , s t r e n g t h of c o s t a e d e c r e a s i n g w i t h d i s t a n c e f r o m f o l d ana s u l c u s . Coetae weak on i n t e r i o r o f s h e l l . v e n t r a l v a l v e a t r o n g l y convex, sulcus bounded by s t r o n g c o s t a e , narrow, deep, marked by t r a c e o f a median c o a t a w i t h i n . Beak strongly incurved. Interarea ahort. Delt h y r i u m about 80°, open e x c e p t f o r a s m a l l I r r e g u l a r deposit of a d v e n t i t i o u s nacre forming a c a l l u s which o f t e n resembles a t r a n s verse d e l t h y r i a l p l a t e . Hinge t e e t h l o n g , sharp, s t r a i g h t . Dental l a m e l l a e strong, l e e s than 1/4 l e n g t h o f v a l v e , d i v e r g i n g from beax p a r a l l e l t o 2nd c o a t a . I n t e r n a l eurface w i t h low, b l u n t median r i d g e through c e n t r a l r e g i o n of v a l v e . D o r a a l v a l v e l e a s convex, more rounded, leea angular. F o l d narrow, not p r o m i n e n t , n o n - p l i c a t e e x c e p t a t a n t e r i o r commissure, where a f a i n t t r a c e of a median f u r r o w a p p e a r s . Beax low, i n c o n s p i c u o u s . Intera r e a v e r y s n o r t , N o t o t h y r i u m wide and s h o r t . C a r d i n a l p r o c e s s s m a l l , low r o u n d e d , v e r t i c ally finely striate. S o c c e t p i s t e s l a r g e and m a s s i v e . R o s t r a l chamber w i t h a d v e n t i t i o u s nacre. Bo d o r a a l median r i d g e . E x t e r i o r except p a l i n t r o p e covered with f i n e c o n c e n t r i c l a m e l l a e , 3.5 t o mm., more c l o s e l y spaced a t a n t e r i o r eage, e a c h l a m e l l a p r o j e c t i n g 0.3 t o 0.3 mm. above s u r f a c e . Between e a c h p a i r o f l a m e l l a e are 4 t o 6 concentric m l c r o - f l l a . Surface (except i n t e r a r e a ) a l s o c o v e r e d w i t h a i c r o - e t r l s e , 14 t o 16 to as. M e a s u r e m e n t s . — H o l o t y p e , w i d t h , 42mm.,'length 9 mm.; depth ( v e n t r a l v a l v e ) 3mm. O c c u r r e n c e . — U p p e r m o s t xone o f the Waterways f o r m a t i o n a t La S a l i n e Rocc. A g e . — L a t e but not n e c e s s a r i l y l a t e s t , M i d d l e Devonian.  135 ilLLkrtl  UPPER  D E V O N I AB B R A O H I O P O D A  SUDTSXBOXQMBA  d i s c r e t e . Hinge t e e t h s m a l l . D e n t a l l a m e l l a e v a r i e s I n l e n g t h , s t o u t , d i v e r g i n g toward b a s e s and toward a n t e r i o r . Bo t r a c e o r a mealan r i d g e . D o r s a l v a l v e e l l g h t l y l e s s convex. F o l d narrow, f l a r i n g b r o a d l y a t i t a a n t e r i o r end, p r o m i n e n t , i t a culmen f l a t t o s h a l l o w l y furrowed. Beax low, I n c o n s p i c u o u s . Hotot h y r l u o wide, ahort. C a r d i n a l procees s m a l l , rounded, v e r t i c a l l y s t r i a t e . S o c x e t a narrow. Socket p l a t e s t h i n . A n t e r i o r t o t h e umbonal r e g i o n l e a low, t h i n , d o r s a l median r i d g e . Exterior with f i n e , close, concentric 1-4, Eloutherokomma a l l i e n Crickmay 1, H o l o - l a m e l l a e . Between l a m e l l a e a r e f a i n t , f i n e , t y p e , from I m p e r i a l Egremont Ho. 1 w e l l a t ooncentrlc m l c r o - f l l a . E n t i r e surface coverea 4430-4446 f e e t d e p t h , mold o i i n t e r i o r o f a w i t h m i c r o - s t r i a e , about 10 t o mm. p e d i c l e v a l v e , w i t h p a r t o f t h e r i g h t mucro o l M e a s u r e m e n t s . — H o l o t y p e , w i d t h 49 mm.; t h e b r a c h i a l v a l v e o i the same I n d i v i d u a l . Tne l e n g t h , 10 mm.| depth ( v e n t r a l v a l v e ) , 3 mm. mucronea a r e m o s t l y , b u t n o t p e r f e c t l y , p r e Occurrence.—In fine grained limestone a e r v e d . x l . 5 . 4, H o l o t y p e , r e v e r s e o f earns none below t h e r e e i s , a t a d e p t h o i 4430 tc specimen, z l . 6 . 4446 l e e t i n I m p e r i a l Egremont Ho. 1 w e l l . A g e . — L a t e r than E. n a m l l t o n l . E a r l i e r EUUTHtHOKOMMA EILLERI than E. b e a r d l which o c c u r s I n l a t e s t M i d d l e t o e a r n e s t upper Devonian. I l e i i t h a r n r n m m . x l l l e r l Crickmay, 1950, J o u r , o l P a l e o n t o l o g y , v o l . 4 4 , p . 4 4 4 . p l . 36, l l g s . 4,6. D e s c r i p t i o n . — S h e l l , average a l e e f o r genua, eubequally biconvex, a n g u l a r l y a l i f o r m I n outl i n e , each e x t r e m i t y produced i n t o s t r o n g l y t a p e r i n g , n e e d l e - s h a r p mucro. L a t e r a l e l o p e s narrow, w i t h 9 t o 14 f i n e , rounded coetae and l u r r o w a o f l i n e w i d t h , s t r e n g t h o f c o s t a e dec r e a s i n g g r a d u a l l y w i t h d i s t a n c e from f o l d and s u l c u s . Costae ahow s t r o n g l y on I n t e r i o r . Ventral valve stronglyconvex. S u l c u s narrow bounded by e t r o n g c o s t a e , unmarked except f o r ' micro-ornament. Beax I n c u r v e d . Interarea ahort. D e l t h y r i u m about 60°, open except f o r l i n e a r c a l l u s upon the i n n e r f a c e o f t h e d e n t a l lamellae; the two opposing c a l l u s e s r e m a i n i n g D e s c r i p t i o n . — L a r g e r than average o f t h e genua, e u b e q u a l l y b i c o n v e x , s t r o n g l y t r a n s v e r s e e x t r e m i t i e s produced i n t o a l o n g Blender mucro. L a t e r a l s l o p e s wide, f l a t t e n e d , w i t h 14 t o 15 f i n e , rounded,prominent c o e t a e , which become i n c r e a s i n g l y s l e n d e r w i t h d i s tance from f o l d and s u l c u s . Costae s c a r c e l y show on I n t e r n a l s u r f a c e o f s h e l l . V e n t r a l v a l v e s t r o n g l y convex, a n g u l a r . S u l c u s bounded by s t r o n g c o s t a e , narrow, f l a r i n g a t a n t e r i o r edge, unmarked. Beak p r o minent, l e e s I n c u r v e d than i n ot:.er s p e c i e s . I n t e r a r e a n o t a b l y l o n g e r than average f o r genua D e l t h y r i u m 50- , open except i o r i a l n t d e v e lopment o f l i n e a r c a l l u s . Hinge t e e t h e t r o n g . D e n t a l l a m r l l a e a t r o n g , 1/3 l e n g t h o f v a l v e d i v e r g i n g w i d e l y toward a n t e r i o r , p a r a l l e l t o t h i r d c o s t s , a t r o n g , sharp median r i d g e f r o m near beak a c r o s s c e n t e r o f i n t e r n a l s u r f a c e . Doreal v a l v e l e s s convex; l e a s a n g u l a r . F o l d narrow, p r o m i n e n t , w i t h b r o a d a h a i l o w median f u r r o w i n i t s a n t e r i o r h a l l . Beak sharp, n o t conspicuous. I n t e r a r e a e h o r t . Not o t h y r i u m wide, a b o r t . C a r d i n a l p r o c e s a l o w , flat, vertically atriate. Socket p l a t e s l a r g e and m a s s i v e . Umbonal r e g i o n l i t t l e o r no c a l l u s . S h o r t , s h a r p median r i d g e e x t e n d s a n t e r i o r l y f r o m I n f e r i o r edge o f t h e c a r d i n a l p r o c e s s l e d u c e n s l a C x i c i o a y , 1, f r o m 1-3, n e u t h e r o x o i for a short distance. M l l l e t - L e d u c No. 16-6 b o r e h o l e a t 6058-6078 f e e t F i n e c o n c e n t r i c l a m e l l a e , 4.3 t o mm. c o v e r d e p t h , mold o f i n t e r i o r o f b r a c h i a l v a l v e w i t h s u r f a c e . Between each p a i r a r e about 6 r e some a h e l l substance showing r i b b i n g and o t h e r gular, concentric mlcro-flla. Fine r a d i a l s u r f a c e marks a t t a c h e d t o i t I n p l a c e s . Outt h r e a d s c o v e r s u r f a c e , about 15 t o mm. Maxes l i n e completed i n b r o k e n b l a c k l i n e . Interior m i c r o s c o p i c q u a d r i l l e p a t t e r n d o r e a l median r i d g e l a f a i n t l y d i s c e r n i b l e . x 2 . 5 . M e a s u r e m e n t s . — H o l o t y p e , w i d t h 60 mm.; length 4, H o l o t y p e . r e v e r s e o f same specimen. Some 11 mm.; depth 4.5 mm. (doreal v a l v e ) , length micro-ornament i s shown aa an i m p r e s s i o n i n t h e v e n t r a l v a l v e 13 mm. m a t r i x , x2.e. 3, P a r a t y p e B o . l , from the same Occurence. — I n f i n e l i m e s t o n e xone b e l o e d a r k e o u r c e , mold of p a r t o f e x t e r i o r o f a s m a l l s h a l e xone.et d e p t h of 60=8-6078 feet 1" V l l l e t p e d i c l e v a l v e . Specimen i s a d e e p l y concave Imp r e s s i o n . M a g n i f i e s t o show micro-ornament, x 5 . 5 Leduc No.16^6 b o r e h o l e , sec.6, T . 4 8 , R.44, west of 4 t h M e r i d i a n . Occurs r a r e l y s l t h E. k i l l e r 1 A g e . — L a t e s t M i d d l e to e a r l i e s t u'pper Devonian. Eleutherokomma l e d u c e n s l e Crickmay, 1950, J o u r , of P a l e o n t o l o g y , v o l . ^ 4 , p.44<i, p i . 5 6 , I l g a . 6 - B .  136  RE1DF0RDI  UPPER u£ VOS I AS BRAOHIOPODA  «l«w;hgrflEPpma r e l d i o r t f l Crickmay, 1, H o l o t y p e , Hay R i v e r , B o r i n v e s t T e r r i t o r i e s , 14 m l l e e from mouth, p e a i c l e v a l v e . S h e l l aubetance e n c r u s t e d • 1 t h minute c o r a l l i n e ana bryosoan c a l c a r e o u a d e p o s l t e . The l e f t mucro l e c o m p l e t e , X 4 . 4 . 4 - 5 , P a r a t y p e H o . l , from the same l o c a l i t y , a epecl.men e l t h both v a l v e s , much e n c r u s t e d , e x t r e m l t l e a broken, X 4 . 0 . 8 , D o r a a l a s p e c t . 3, p o e t e r i o r a e o e c t . 4, a n t e r i o r a s p e c t . 5, l e f t l a t e r a l aaoect. 6, Paratyoe Bo. 4 , from same l o c a l i t y , b r a c h i a l v a l v e , e x t e r n a l a a p e c t . Both mucronee broken o n . U a g n i f l e a t o show some micro-ornament, x3.4. tLKJTHIHOKOlUA REIDFORDI  K'H^TTyfUfinfl  Paleontology,  r c l d f o r d l Crickmay, 1950, J o u r . v o l , 4 4 , p . 4 4 4 , p i . 3 7 , f i g e . 4-9  ElJUTHEROKOahA  D e s c r i p t i o n . — S n e l l average s i c e or l a r g e r , eubequally biconvex, angularly a l l i o r m , long, n e e o l e - l l x e mucronee. L a t e r a l s l o p e a s l o e , a l t b 18 t o 30 r o u n a e a c o s t a e ana s l i g c t l y narrower f u r r o w s . Costae d e c r e a s e i n s t r e n g t h w i t h d i s t a n c e f r o m f o l d ana sulcus,* beyond the 1 4 t h c o e t a e , they d e c r e a s e g r e a t l y i n l e n g t h , t e n d i n g to r u n not r a d i a l l y out parallel. On tbe i n t e r n a l s u r f a c e of the s h e l l c o s t a e show m a i n l y towara the a n t e r i o r edge* they are f a i n t or absent i n o t h e r r e g i o n s . B n e i i substance t n l c x . V e n t r a l v a l v e s t r o n g l y convex. S u l c u s a v e r age w i a t n , e v e n l y t a p e r e a , deep, s l o p i n g s l t n i n to a narrow bottom, unmarxea. Beax a t r o n g l y Incurved. Interarea snort. Delt h y r i u m about 30°, open e x c e p t f o r a r e g u l a r , massive c a l l u s . Hinge t e e t h s t o u t , l o n g . D e n t a l l a m e l l a e e t r o n g , 1/3 l e n g t h o i valve, r e l m o r c e d with considerable c a l l u s i n tne umbonal c a v i t i e s ana w i t h a v e r y r e g u l a r c a l l u s i n tbe d e l t h y r i a l c n a a b e r , d i v e r g i n g s t r o n g l y towara t n e l r bases, ana d i v e r g i n g i r o a the beak p a r a l l e l to the second c o e t a . Low median r l a g e only i n young e t a g e e . D o r s a l v a l v e l e s s convex. F o l d narrow, s l i g h t l y f l a r i n g , mar sea by a s h a l l o w l u r r o w . Beax s t r o n g e r , more c o n s p i c u o u s than o t h e r s p e c i e s . C a r d i n a l p r o c e a s d i v i d e d by a s l i g h t central concavity, v e r t i c a l l y s t r i a t e . Socke t a s h o r t , deep, r o u n d i s h . Socket p i a t e e massi v e , c u r v e d , r e i n f o r c e d w i t h c a l l u s i n the r o s t r a l c a v i t y . Median r i d g e v a r i e s . E x t e r i o r has f i n e , c l o s e c o n c e n t r i c l a m e l l a e i r r e g u l a r l y spaced. Lamellae f a r t h e r a p a r t on umbonal r e g i o n , c l o s e r i n a n t e r i o r r e g i o n . Surface covered w i t h m i c r o - s t r i a e , 7 to 10 per ma. Tend t o o b l i t e r a t e m l c r o - f l l a . M e a s u r e m e n t s . — H o l o t y p e , w i d t h 59am.; l e n g t h 11.5am.; d e p t h , 4 mm. A g e . — F i n g e r Lakes age ( e a r l y t o m l d - y r a a n i a n j .  157. Genus MERISTKT.TiA Hall 1 8 5 9 , n. gen. In Hall and Clarke, Nat. Hist, of New York, Vol. VIII, pt 2, p. 5 U . "Diagnosis: Shells having the same general external characters as Merista. Valves convex, often inflated, cardinal areas obscure. The umbo of the pedicle valve i s incurved at maturity, concealing most, i f not a l l of the foramen; in early stages of growth, however, the beak is more erect and exposes the deltidial plates in an elementary condition of development. The anterior margin of the shell i s sinuate, and usually there i s a sinus on the pedicle-valve, with a less conspicuous fold on the brachial valve; sometimes both valves bear a low sinus, or the sinus on the pedicle-valve may be absent, while the fold on the brachial valve i s present, thus giving the shell a nasute anterior extension; again, fold and sinus may be absent on both valves* In the interior of the pedicle-valve the delthyrium i s wide, i t s margins being thickened into dental ridges. The teeth are conspicuous, often much thickened and curved backward at their tips, interlocking with the opposite valve in such a manner as to make a very firm articulation. The teeth are supported by lamellae which rest upon the bottom of the valve, and are continued for a short distance about the posterior margin of the muscular impression. In old shells this portion of the valve becomes greatly thickened, the muscular impression correspondingly deepened, and the identity of the dental lamellae i s obscured by their becoming merged with the substance of thew-«alve. The pediclecavity i s deep and frequently shows a strong muscular scar. The impression of the diductor muscles i s subquadrate-ovate or subtriangular i n outline, very strongly impressed and usually clearly divisible into i t s two lateral components. The central adductor scar i s faint, but linear when retained. The lateral scars are deeply striated longitudinally. The anterior margin of the muscular area i s frequently obscure but i s not infrequently a ridge from which radiate fine, anastomosing p a l l i a l sinuses. In the post-lateral regions the ovarian sinuses are sometimes retained. In the brachial valve the beak i s depressed and sometimes obscured by the incurvature of the umbo of the opposite valve. The dental sockets are narrow and divergent. The hinge-plate i s subject to some unessential variation i n form. Usually i t i s triangular, concave on the upper surface, and divided into two lobes by a median groove. The crura take their origin from just within the anterior margins of the lobes thus formed. In some species the hinge-plate i s more subquadrate in outline, the variation being produced by the development of post-lateral expansions. This plate i s supported by a median septum, which extends for somewhat more than one-third of the length of the valve. The crura are short and stright, and the primary lamellae of the brachidium originate from them at an acute angle, and come into closest appoistion at the anterior extremity of the median septum.  1158.  In the mature individual, the spiral ribbon makes about fifteen volutions, the bases of the cones being subparallel.to the longitudinal axis of the shell and their apices directed toward i t s lateral margins. In their general shape the cones conform to the character of the interior cavity, and in the less convex species (M. Walcotti, M. lenta), they are appressed on the side of the flatter or brachial valve. The structure of the loop i s the same as described for the genus Merista, with this difference, however: the circular arms of the loop curve f i r s t outward in the horizontal plane, then backwa- d and abruptly downward to the inner edges of the primary lamellae: in their return the same curvature i s reversed and they therefore meet the stem of the loop in the horizontal plane, their point of union being invariably above the point of coalescence of the lateral branches of the loop. The muscular area i s elongate-ovate, and extends far the entire length of the median septum; the four adductor scars are sometimes distinctly seen, the posterior pair being broader and embracing the posterior extremities of the anterior scars. External surface of the valves smooth or with concentric striae. Shell structure fibrous, impunctate. 11  Genotype:  Merista laevis, Hall.  Lower Helderberg group.  159. Genus PLATYil&CHKF.T.A F e n t o n and F e n t o n , n . gen* Eenton and Fenton (1°2U) The S t r a t i g r a p h y and Fauna o f t h e H a c k b e r r y Stage o f t h e Upper D e v o n i a n , M a c M i l l a n , p , 158* "Description: Shell s p i r i f e r o i d , small t o large, with high and n e a r l y f l a t c a r d i n a l a r e a . S u r f a c e marked b y s t r o n g p l i c a t i o n s , w h i c h may be e i t h e r f i n e o r c o a r s e . D i a g n o s t i c characters are the presence o f a w e l l - d e f i n e d d e l t h y r i a l p l a t e and i m p u n c t a t e s h e l l structure. The former s e p a r a t e s t h e genus from S p i r i f e r , and t h e l a t t e r from P s e u d o s y r i n x , w i t h t h e genotype b e i n g most l i k e t h e l a t t e r genus i n g e n e r a l appearance. I t seems p r o b a b l e t h a t many, i f n o t m o s t , o f the S p i r i f e r - l i k e s h e l l s p o s s e s s i n g d e l t h y r i a l p l a t e s s h o u l d be r e f e r r e d t o t h i s new genus. C e r t a i n l y , t h e assumption o f H a l l and C l a r k e t o t h e e f f e c t t h a t p u s t u l o s e s u r f a c e i n d i c a t e s p u n c t a t e s t r u c t u r e i s n o t t o be r e l i e d upon, f o r P . m a c b r i d e i , w h i c h i s s t r o n g l y p u s t u l o s e , does n o t show t h e s l i g h t e s t t r a c e o f punctae. That t h i s i s n o t a m a t t e r o f p r e s e r v a t i o n i s shown b y t h e f a c t t h a t a s s o c i a t e d s p e c i e s , such as C y r t i n a i o w a e n s i s , show t h e punctae v e r y p l a i n l y . A p p a r e n t l y t h i s new genus o c c u p i e s a p o s i t i o n a n c e s t r a l t o W e l l e r ' s P s e u d o s y r i n x , w h i c h p o s s e s s e s the p l a t e v e r y s t r o n g l y d e v e l o p e d , and c o a r s e p u n c t a e . I t , i n t u r n , appears t o be a n c e s t r a l t o S y r i n g o t h y r i s , w h i c h i s p u n c t a t e , and p o s s e s s e s b o t h d e l t h y r i a l p l a t e and s y r i n x . Genotype:  S p i r i f e r macbridei Calvin  Genus SPIRIFER Sowerby, 1815 n. gen. Description from Geol. Surv. of New York, Part II, p. 5. "Shells transversely elongate, rarely produced axially; with or without median fold and sinus. Hinge-line straight, usually forming the greatest diameter of the shell, but i n some of the subdivisions of the genus, short and inconspicuous. Cardinal extremities alate, acuminate or rounded. Surface covered with granulations, striae, plications or costae, variously g rouped and which may be present or absent on the median fold and sinus, these are crossed by concentric growth-lines which may take the form of varices or expanded lamellae, or be modified into frimbriae of simple or compound spines. In the subgenera Martiniaand Martiniopsis the surface i s smooth except for the concentric striae. Shell substance fibrous, impunctate except as below described, i n the smooth species the epidermal layer i s minutely pitted. The pedicle-valve has the umbo more or less elevated over the hinge-line, the apex acute, erect or incurved. The cardinal slopes show a slight tendency to concavity or excavation, and the median portion of the valve i s more or less strongly depressed by a sinus. The cturdinal area i s broad, f i s t or incurved and i t s surface i s transversely striated, the inner shell-layers bear a series of longitudinal or vertical canals at whose marginal extremities the fibrous tissue i s produced into a row of denticles, corresponding to a row of pits on the opposite valve, thus forming an accessory articulation of the valves. The essential articulation i s effected by means of stout, simple teeth lying at the marginal extremities of the triangular deltidium and supported by dental plates which are usually short, but, i n rare types, may be produced even to the anterior margin of the valve. The pedicle-passage or delthyrium i s usually open. Normally i t i s closed by a pair of deltidial plates having the form of scalene triangles, which develop from the sides of the delthyrium and meeting, enclose wholly or partially a circular or oval pedicle foramen. At normal maturity these plates become anchylosed along the median suture and form a single convex plate (the so-called Pseudodeltidium). The usual absence of the deltidium may be due either to accidental removal or to resorption with advancing growth. In the adult and senile stages of development many species, especially i n the line of development to:Syringothyris, form a testaceous callosity in the pediclecavity, thickening the umbo and extending across the delthyrium, reaching in extreme cases, nearly to the cardinal margin. The muscular area consists of a subtriangular pedicle-impression occupying the pedicle-cavity, and continuous with a deeply impressed oval or obcordate area, which i s posteriorly situated and divisible into a  141  narrow median adductor and broad lateral diductors, the surface of the latter being marked by radiating or.racemose furrows. The posterior and anterior members of the diductors may frequently be distinguished, the former being of less extent and their surface markings somewhat different from those of the latter. A median septum in this valve i s usually absent: occasionally i t i s i n a condition of incipient development, and i n certain species having the aspect of SPIRIFERINA and belonging to the line of descent of which this genus may be regarded as the final or accessory product, i t forms a most conspicuous feature of the interior. In the brachial valve the umbo i s inconspicuous, the apex only being incurved over the cardinal area; a median fold corresponds to the sinus of the opposite valve. The cardinal area i s narrow and divided by a broadly triangular delthyrium. The dental sockets are narrow, moderately deep and bounded interiorly by highly developed socket walls, the extremities of which support the crural bases. The cardinal process i s a low, transverse, sessile apophysis, having i t s surface vertically striated; occasionally i t i s bipartite or i t may be wholly resorbed. The crura are long, straight and slightly divergent: their union with theprimary lamellae of the spiral ribbon i s at a broadly obtuse angle. The brachial coils are directed outward and upward toward the cardinal angles of the valves and their variation i n size and direction i s i n keeping with the differences i n the marginal outline of the shell. The number of revolutions of the ribbon exceeds that i n any other genus of brachiopdds. There i s no loop; i t s position, however, i s indicated by a pair of short spinous processes originating on the primary lamellae soon after their junction with the crura, and which are directed inward with a slight convergence. The muscular area has about the same extent as that of the pedicle-valve, though less distinctly impressed and generally more elongated. It i s constituted of two pairs of adductor impressions with their surfaces radiately or palmately striated. The anterior pair are central, narrow at their posterior extremities which are embraced by the broader posterior scars. A faint median septum i s sometimes present. In some instances of importance the socket walls are supported by septa which may be considerably produced over the bottom of the valve. In both valves the genital region i s distinctly punctated, but vascular markings are rarely observed." Genotype:  Anomites striatus, Martin.  AaOCITAalUB  «• • * I  N  UPPIH UtVOaUK BHAOHIOPOUA  I  JBU11IX Mm.M.UI Meex, 1. A ventral i l i i . a , C a r d i n a l via* of aaaa apeelaea, anoalng Ita loa, atrongly Incurved araa, ioraaan, ato. 3, A doraal view of aaaa. •PIRIHH AHOINTAHIUi  aaUUIli  I J ^ l . i J l u j Hoot, 1677, Part I Peleeatelogy u. a. Oeel. i r p l . 40 th Par. (King' Vol. 4. p. 4a), p i . 3, tlga. 4, 4 a, and 4 b. when rather aaall, aodarately convex, older than leag, aad having a general eubeealoireuler or eubtrlgonal outline, with the greateet breadth ea tha hlnge-llae. Lateral e x t » realtlee asutely angular. Valvee nearly equally sea vex. ventral valve with the aoet aeavexIty betweea the alddle and tha uabe. Beak atrongly Incurved. Area lew, with aeerly parallel eloee near the break, but eoaewhat abruptly narrowed at tha lateral extreaitlee, though oonttnued the entire length ef the hinge, foramen wider than high. Mesial sinus ahailow and narrow, but well oeilaed by the aerglnsl r i b on each aide exteed lag quite to the beak, aad without oeatae. Lateral alepea eaoa occupied by froa la ta 14 alaple radiating coatee, whleb dlalalab very gradually la alaa toward the l a t a r a l extreai t l e e . Doreal valve aoet convex near the alddle. Beak rather alotlnetly Incurved, aealal told correeponulng la alae to the elnua el tne other valva, being rather low, aad flattened on top along i t a whole leagtb  ultn a lurrow along Ita alaois. Lataral alopaa ooatats, aa la tha other valve, lurtaca ef both valvta aarkad alth very flaa, regular, undulating llnee of groeth, aoet utatlnct between tbe ooetaa. Length, 0.66 lncn; breadth, O.bO laon; convexity, 0.44 laoh.  143  DISJuTJCTOS  UPPER DEVONIAN BRACHIOPODA  Trans. Oecl. Soc. London, 2nd 3er.Vol.5. p i . l i l i , f i g s 1, 2 and 13. S ? a r f a DISJUTXTUS (jcverby) Sescrlptioni S e i r l c i r c u l s r with an snarginnte f r o n t , very ccr.vex rndiated J p i > e r v a l v e with stout 12 r i b s much r a i s e d lr. f r o r . t , f o r c i n g a rounded elocia*.Ion; r i b s ro.ir.ded, nunicrcus, ol.oui 25 on each side c f n i d d l e , beaks renote; hinge area broad curved, i t s e d g e ? neflrly pprellsl. I . c c a l l t y i Ban.staple;, Snglnnd. Diagram r i g . 1. Central view F i g . 2. Vorsal view.  SPIRIFER  144  UPPER DS7CNUN BRtdOXKIDA  sprarrsa (HAHTDm)  PSJUHHNH  Meet  (1669)  Trans. Chlo. Acad. S c i . Vol. 1, 1867-9, p. 107. SPIHIFSa (MARTIN Ix) FMmLlm Meek Shell rather large, orbicular, aubquadrate io outline, moderately gibbous; hinge equaling about three-fourths of the greatest breadth, and roondod at the extremities. Dorsal valve moderately convex, (tha most sroadnent part being i n tbe central and *""Hvv' regions), provided near the front with a las, undefined mssial prominence 1  SPlttlPJfll Martinis  which scarcely reaches ths middle, and i s marked by a shallow longitudinal depression; bosk extending a l i t t l e beyond the hinge and rather distinctly Incurved; area narrow end not extended to the extremities of ths hinge, and d i s t i n c t l y arched. Ventral valve more gibbous than tha othsr, i t s most prominent part being between the middle and ths beak, which i s prcduoed beyond that of tba . other valve, and d i s t i n c t l y incurved; mssial sinus very narrow, shallow, and extended nearly to the beak, forming a short asadolraular projection i s front, f i t t i n g into s corresponding sinuosity in ths front of tha opposite valve; area moderate, continued to the extremities of the hinge; finely striated both ways, and d i s t i n c t l y arched and Inclined back over ths cardinal l i n s - i t s l a t e r a l margins at f i r s t sloping from ths beak, then extending oat parallel to the hinge margin for s short distance, after which they again alope to the extremities of ths binge; foramen broad at the base and narrowing rapidly to ths beak, closed for half ths diets nee down by a rather convex psevdodeltldiun, which l e arched on the lower margin. Surface a'Tjnrently nearly smooth, excepting a few small marks of growth, but snowing, under a magnif i e r , very fins, obscure, closely arranged concent r i c atrias, with some appearance of minute radiating striae. Length from front to beak of dorsal valve, l.li7 inches; do. to beak of ventral valve, 1.80 inches) greatest breadth, 1.9k inches; convexity of the two valves, 1.2b inches; length of hinge, l.$U Inches. Mackenzie river, forty miles below tha "Ran parta. i Diagrams! 1. Ventral view 2. Side view 3. Dorsal view.  145 KBHCOTTI  OTTJR DSVONIAB BfUCKUPODA  SPIRITS! KBRNIOORI I  (1869)  Trass. C M C Acad. Sol. Vol. 1, 1867-9, p. 101. SPTJUFBB  IEMMIUUTTI  Bask  Shall snbatmrl nlrcalirr, rathar ooBprasssdt valves nearly squally convoxj length less thsn half the breadth) greatest breadth en the hinge line, which i s extended apparently into s point st each extremity. Dorsal valve most convex near the middle, thence earring aore rapidly to the beak thsn to ths frontj sides sloping very gradually and becoming rather flattened near tha extremities! beak sesawhat eaaprsBsed, scarcely projecting beyond the hinge l i n e , and with the linear ares a l i t t l e Incurved! mssial fold narrow and scarcely distinct from the general convexity of the central region, excepting near tba front. Ventral valve HOTaBILIS  SPIRIFER  very s l i g h t l y loss convex than tha other,, most prominent between ths middle and the beak) lateral slopes a l i t t l e lass flattened than i n ths dorsal valvaj mesial sinus narrow, rather shallow, with rounded margins, continued nearly to the beak, from which It widens and dsspsns-very gradually to ths anterior margin, where i t produces s moderately distinct, narrow emsrglnetleni beak e l i t t l e incurved and mere prominent thsn that of ths other vslvs, but not produced mash beyond the margin of i t s own area, which i s narrow, with nearly parallel margins, and inclined, with s slight curve, back over the binge) foramen presenting nearly ths form of an equilateral triangle. Surfsea with shoot twentysix to t h i r t y simple, regular, we 11-defined, radiating costae, on each side of the mesial fold and sinus, separated by depressions of their own breadth. The mssial sinus and depression are also each occupied by s i x or seven more or leaa bifurcating eostsa. By ths eld of s good magnifier, faint traces of numerous minute, closely arranged concentric striae pod granules are also seen on a l l parts of the surface. length, 0.6U inch] breadth, l.US inches) convexity, 0.3B inch) height of ares i n ventral valve, 0.10 inch. Locality! Llsrd's r l v s r , lat. 60 dag. 15 min. N., long. 123 dag. W. I t waa found loose, but most probably belongs to rocks of about the age of the Hamilton group in the immediate nelgbbocrhccd. Diagrams!  uTPItt D K V O H I A H  1. Ventral view 2. Dorsal view 3. Side view.  BRACHIOPODA  SPIRIFER  of v a l v e s . A p l i c a t i o n i s i n some s h e l l s present i n the bottom o f the s i n u s . The f o l d i s g e n e r a l l y marked by a s l i g h t median depression which i a obsolete i n tbe post e r i o r t h i r d o f the f o l d . The two p l i c a t i o n s l i m i t i n g the s i n u s are much stronger than those on e i t h e r s i d e . Surface of each valve merged by 44 t o 30 p l i c a t i o n s . Of these three t o s i x on e i t h e r side o f the f o l d and sinus o r i g i n a t e a t the hinge near the beaks and diverge toward the f r o n t o f the v a l v e s a f t e r the u s u a l manner i n B o i r l f e r . The remainder o f the p l i c a t l o n a which l i e between theae and the e x t r e a l t l e e of the hinge, have the remarxable p e c u l i a r B o i r l f e r a o t a b l l l e K i n d l e . 1, Fragmentary d o r s a l v a l v e , a, 3, Ventral and d o r s a l v i e s a i t y o f extending forward normal or n e a r l y normal t o the hinge l i n e . These l a t e r a l p l i of a specimen. 4, Beaks and area, showing cations, have, moreover, the p e c u l i a r i t y of d e l t n y r l u a , St. 5, Dorsal v a l v e , showing being o f the same or g r e a t e r e l s e a t the f i n e l a m s l l o s e s t r i a e . Tbe s h e l l i s t i l t e d binge l i n e than i n f r o n t , being thus ouch s l i g h t l y lorwara, showing beak and area o f stronger and more prominent a t the hinge v e n t r a l valve. l i n e than the othere. In some specimens one of the strong n o d e l i x e outer p l i c a t i o n s a d j SPIRITS* HOTABILIS acent t o tbe f i n e r s e r i e s c o a l e s c e s w i t h one o f the l a t t e r a short d i s t a n c e from the S p i r i f e r v t a b l l l e K i n d l e , 1909, 0. 8. binge l i n e . The d i v e r s e d i r e c t i o n e of growth Oeol. Surv. B u l l . 391, P I . V I I , p. B6. o f the two s e r i e s of p l i c a t i o n s r e s u l t I n three o r four o f the outer s e r i e s bending S h a l l moderately gibbous, t e r m i n a t i n g a b r u p t l y i n conformity w i t h the d i r e c t i o n l a t e r a l l y i o slender mucronate e x t e n s i o n s . of the d i v e r g i n g s e r i e s on coming i n t o conWidth three or four times the l e n g t h . t a c t w i t h them. Tbe p l i c a t i o n s are c r o s s e d A t r i a n g u l a r d e l t h y r i u m covered by a conby a s e r i e s of l a m e l l o s e s t r i a e which are vex deltldum reaches to the be ax of the e x f o l i a t e d i n most specimens. v e n t r a l valve. The small pointed beax o f the v e n t r a l v a l v e . The small pointed beax The p e c u l i a r a e r i e s of p l i c a t i o n s on of the v e n t r a l valve i s incurved over the the mucronate expansion o f the s h e l l a l s delthyrturn. t l n g u i e h I t from any other S p i n i e r . In The v a l v e s are d i s t i n c t l y gibbous i n t h s other r e s p e c t s i t c l o s e l y resembles 3. b l m e s l a l l s H a l l . median r e g i o n and show a s l i g h t l y concave p r o f i l e between t h i s and the extended mucronate expansions. A r a t h e r narrow f o l d and s i n u s extend f r o a the beax t o the f r o n t  146  DEVONIAN BEACaiOPODA  SPIBI1SB  non-ooetate elnue. l a e d o r s a l v a l v e l e low, o n l y e l l g h t l y e l e v a t e d , and hap a somewhat f l a t t e n e d median f o l d . The o e r d l n a l area l e f l a t and I s not t r i a n g u l a r I n shape.  g  f I HI FSB RAYMOND! Haynas (1916) L a i r d , W.U.,  Journ. f a l e o n . , V o l . £1, 1987  S p i r i f e r rcvaonal  Haynee  D e s c r i p t i o n ; E l l " 9 p l r l f e r I n moat abundantly represented I n the c o l l e o t l o c s from Montana.  figmarve: With the e z o e p t i o n o f P i a e , t h i e form appears almotrt l d e n t i o a l .1th t h e S p i r i f e r J a n p o r e n H l H earren » L . ; h i n t u r n appears t o be l d e n t i o a l mith the S p i r i f e r a r g e n t a r l t i B MeeV; C e r t a i n l y much r e v i s i o n o r the F p i r l f e r s o f the Boo>ry Mountain area i n needed. Age and L o c a l i t y : Upper Devonian. Limestone member o f J e f f e r s o n f o r m a t i o n , Montana. Diagram.:  The vulvop have an average a l d t h o f £3 mm. w i t h i n the l i m i t s o f 16 t o 4 4 mm. Ihe l e n g t h o r the v a l v e runp from 7 t o IB mm. averaging li mm. Tha r a t i o o f a l d t h to l e n g t h l e about 1.B0 t o 1. Tbe average thlcvneep o f teo epeoimen l a 9 mm.  Fig. 1 and 3 - Doreal v i e s - V e n t r a l view He. £  The rtiellR are t r i a n g u l a r i n o u t l i n e and noma o f the s h e l l p , p a r t i c u l a r l y the l a r g e r onen. tend t o be very e l a t e . Ihe "urface o f the v a l v e P l e covered w i t h etrong pubrounded coetae. Ihe average number o f coptae on the v e n t r a l v e l v e 1 P 18, running from 14 to £6. The average number o f coetae on the d o r e a l v a l v e i s 17, running from l b t o £0. The cumber o f coptae appear t o lncreape with t h e p l i e o f the i n d i v i d u a l . No P t r i a t i o n p p a r a l l e l to the coptue eere observed. Growth l i n e s cono e n t r l o e l t h the a n t e r i o r (.art o f the s h e l l a r e i n d i s t i n c t l y present i n a fee specimen?. She ver.trol v a l v a l p o n l y moderately e l e v ated I n the umbonal r e g i o n and h a s a d i s t i n c t , HiUUHDSQHI  SPTRIF31 Martinis  OPPSt DEVONIAN BRACHIAPQDA  truncated, or very faintly sinuous in the middle. Ventral valve A) out one-third more convex than tha other, provided i n front with a shallow, subangular, undefined mesial sinus, which dies out before reaching the middle of the valve) beak rather pointed, moderately prominent, and Incurved but not projecting more than one-eighth tha entire length of tha ahell beyond that of tha other valve, from which i t stands s l i t t l e remote) area broadly triangular, not distinctly defined, arcuate; foramen triangular, unclosed, higher than wide. Doraal v alve moderately convex, and without a mesial fold even ± the immediate front) beak small, projecting l i t t l e beyond the hinge, and not distinctly incurved, provided with a narrow area. Surface (of internal east) showing faint indications of eighteen to twenty remote linear, radisting ridges on each valva, so indistinct as to leave doubts whether or not they ware connected with external costae. Length, 0.55 inch) breadth, 0;65 inch) convexity, O.uu inch. SPffilFHt (MARTIN IA) RICHARDSON I Week (1869) Trans. Chic. Acad. Sci. Vol. 1, 1867-9, p. 10u. SPlRiyjR__( HART IN IA) RICRAKD30HI Meek Shall small, wider than long, rather gibbous, hinge line about as long as half the transverse diameter of the valves) lateral margins rounding somewhat abruptly into the hlngo margin, and converging with e slightly convex outline to the front, which i s a l i t t l e  Locality? Fort Good Hope, on Mackenzie river, 1st. 66 dog. N. long. 128 deg. V. Diagramsi  1. Ventral view 2. Dorsal view 3. Posterior view.  147  S p i r i f e r p l h o n e n s l s Keek 1877, 1, P r o f i l e view, n a t u r a l e l s e . 3 , D o r s a l v i e s of aai 3, v e n t r a l view o f same.  spiBiFra piBOsssaxa S p i r i f e r plaanenelo M e * 1877, P a r t I , P a l e o n t o l o g y 0. 8. O e o l . E x p l . 40 t h F a r . ( l i n g ) V o l . 4. p . 4 5 . p i . 1, f i g a . S, 9 a.e-b. S h e l l a t t a i n i n g about a a e d l u a a l a a , eomewhea a l d e r than l o n g , T a r r i n g f r o a tranew veraely-euboval to a nearly s e m i c i r c u l a r g e n e r a l o u t l i n e , r a t h e r gibbous i n a d u l t examplee. Cardinal aargln nearly or quite BepallBg^tse g r e a t e a t b r e a d t h , and t e r m i n a t l a g l a r e o t a n g u l a r or r a t h e r more obtuse extremities. L a t e r a l a a r g i n a r o u n d i n g t o the f r o s t , whioh Is a o s e t i a a a rounded, eometiaee a l l g h t l y a i n u o u s , or i n o t h e r e x a a p l e e more prominent and aubangular l a the m i d d l e , vent r a l v a l v a g e n e r a l l y r a t h e r more gibbous than the o t h e r , i t s g r e a t e a t c o n v e x i t y b e i n g l a the uabonal r e g i o n , f r o a which i t rounds o f f e v e n l y toward the f r o n t and l a t e r a l a a r g i n a as w e l l aa to the beak, whioh pro— j e e t a beyond t h a t of the o t h e r v a l v e , ana l a rather d l a t i a c t l y incurved. Cardinal area _of_aederate_hel(tht, narrowed_to_ the l a t e r a l  8TRI00B0B  1  add s t r o n g l y erohed w i t h the beak. Foraaan having n e a r l y the f o r a of an e q u i l a t e r a l t r i a n g l e , and p r o v i d e d w i t h s l i g h t l y - r a i s e d sharp, l a t e r a l a a r g i n a . Mesial sinus shallow, rounded, smooth, and of moderate o r e a a t h , narrowed r e g u l a r l y , ana w e l l d e f i n e d t o the apex o f the beak. Doraal v a l v e g e n e r a l l y aora than a a a i o i r c u l a r , moat convex i n the c e n t r a l and a n t e r i o r r e g i o n s . Beak p r o j e c t i n g l i t t l e beyond the c a r d i n a l a a r g l n , and w i t h the narrow a r e a i n c u r v e d . M e s i a l r i d g e d e p r e s s e d , smooth, and f a i n t l y furrowed along the m i d d l e , c o r r e s p o n d i n g i n o u t l i n e to the form o f the a l n u a i n tbe o t h e r v a l v e . Sariaoe or eaen v a l v e ornaaentea by from 11 to 14 a l o p l e , r e g u l a r , r o u n d f c , r a d i a t i n g p l l o a t l o n a on each e l d e o f the a e a l a l f o l d and a l n u a , and a l a o ah owing, under a m a g n i f i e r , minute, r e g u l a r , crowded, r a d i a t i n g a t r l a e , orooeed near tbe f r o n t by e t r o n g e r u n d u l a t i n g l i n e a o f growth. Length o f a m e d i u a - e l i e d specimen, 0.B3 l n o h | b r e a d t h o f the ease, 1.30 i n c h e s ; o o B v e x l t y , 0.73 i n c h .  BPIRIFSR  UPPER DEVOHIAH BRAOHIOPODA  3  3  a c i r i f e r atrlgOBua Meek 1877. 1, View o f v e n t r a l v a l v e , 3 , view of d o r e a l v a l v e . 3, P r o f i l e view of  SPIRIFER STRIOOSUS  S  avium  UPPER IS VOS I AB BRAOHIOPODA  puomsxs  m f a r B t r l r o B u a Meek 1877. o. s. O e o l . P i . o f 40th P a r . P t . 1, P I . 3 , P i g s . 5, B a , 5b. S h e l l under medium e l s e , convex, BUD— t r i g o n a l , or approchlng sub s e m i c i r c u l a r , w i t h the g r e a t e a t b r e a d t h on the h i n g e - l i n e . Lateral e x t r e a i t l e e generally acutely angular. L a t e r a l margins o on v e r g i n g t o r t h e prominent, aubangular mladle o f the f r o n t , with a somewhat s t r a i g h t e n e d or convex o u t l i n e . Dorsal valve convex i n the m i d d l e , and coapreeaed toward the l a t e r a l e x t r e m l t i e a . Mesial f o l d narrow, prominent, and aometinea aubangular near the f r o n t , c o n t i n u e d to the beak, vent r a l v a l v e s c a r c e l y more convex than the d o r a a l , most gibbous i n the umbonal r e g i o n , w i t h convex l a t e r a l a l o p e e . Beak moderately prominent, and d i s t i n c t l y I n c u r v e d , area narrow, w e l l a e f l n e d , and narrowing o f f l a t e r a l l y , BO aa not q u i t e to reach the e x t r e m l t i e a of the h i n g e , a r c h e d , and d i r e c t e d o b l i q u e l y backward w i t h the beak, rather d i s t i n c t l y s t r i a t e d v l e r t l c a l l y . Mes-  i a l a l n u a cor r e s p e n d i n g i n e l s e t o the f o l d o f the other v a l v e . Surface o f e a c h v a l v e with 30-26 r a d i a t i n g c o a t a e , some o f whioh ore s i m p l e , w h i l e o t h e r b i f u r c a t e , about 6 or 7 u s u a l l y occupy the a e a l a l f o l d ana sinus. 3 or 3 o f those w i t h i n each margin o f the s i n u s u s u a l l y c o a l e s c e w i t h the two marginal onea, whioh a l a o g e n e r a l l y each g i v e o f f a l a t e r a l r i b on the o u t e r a i d s . Costae o f the a e a l a l f o l d more or l o s e b i f u r c a t i n g , while those of tbe l a t e r a l a l o p e e o f both v a l v e e are acre f r e q u e n t l y e l m p l e , but some t i n e a d i v i d e d . F i n e r a u r f a c e - o a r k i n g s unknown. Length, 0.63 C o n v e x i t y , 0.57  lnoh. lnoh.  B r e a d t h , 1.18  inch.  148 HHOTBTT  DEVONIAN RRACHIOFQDA  SPJAXTBB  farm sharp, though abort mucronatians. iroa high, flattened below and arched naar tha beak, marked by fine vertical striae. Delthyrium broadly triangular.  SFiHlHg wTHIrBKTI Ball Fenton and Fenton (192L) Mich. Ofclv. M&a. Gaol., Ccotrib. rol. 1, p. ll<6, pi. 28, tigs. 1-9, pi. 30, figa. Ui-19. SPIRITS mflBBTI Ball Description! Shall of medium or large else, with gresteat width along the hingeline. Length of pedicle valva, 17 mm., brachial valTo, 16.9 mm. width, 30 cm. thlokneaa 16 nm., height of cardinal area S.mu  Braohial valve less convex than tha pedicle, with marl man convexity near tea umbo. Shell elopes abruptly to tha cardinal margin in the unhonal region but is depressed laterally. Surface cf the ahell marked by fins, Irregular, radiating striae. Remarks i Spirifer whltneyi and its varieties are I the Heckberry representatives) of the group to which belong 5. diejttnctua. S. verusuill, S. archiacl. and other apsclxena both European and American. Diagramsi 1. Ventral view. 2. Posterior view. 3. Anterior view.  Pedicle valve moderately convex in the anterior two thirds, with tha curvature increasing la the tmhonal area. Beak prominent, recurred. Shell curves abruptly to the cardinal margin In the region of the beak, lesa so laterally, end is flattened near tha extremities, which are produced to  •BltBSTI v a r . ABIMASEB8I8  UPPER DEVOBIAB BRAOHIOPODA  a o l r l f e r w h l t n e y i vaz. anlaaeenela ( S i x t y ) 1,3, Doraal and v e n t r a l vlewe o i a small specimen showing t e i e t e o beaka. 3, Dora a l v a l v e . 4, V e n t r a l view ehowlng the g r e a t l y e l e v a t e d area of t h l a v a r i e t y . SPIRI/iK IHITNETI var. ABIMA8EB8I8 S p i r i f e r w h l t n e y i var. anlaaeenele ( G i r t y ) K i n d l e lBOfl, ti. 3 . Oeol. 3urv. B u l l . 301, P I . IX, P. <S5, Thla v a r i e t y repreeente a type which can g e n e r a l l y be d i e t i n g u l a h e a from 8. w h l t n e y i by i t a smaller a i r e , tbe more e l e v a t e d area of the v e n t r a l v a l v e , the s l i g h t l y t w l e t e d and but s l i g h t l y incurved v e n t r a l beax, and the more rounded p l i c a t i o n s . P e r f e c t l y preserved epecleans f r o a Bee Mexico which seem t o be i d e n t i c a l w i t h t h i s v a r i e t y , aa d e a c r l b e a by O l r t y from Colorado, show granulosa p l i c a t i o n s covered w i t h very f i n e r a d i a t i n g s t r i a e . There i s wide v a r i a t i o n i n the c h a r a c t e r o f the area o i the v e n t r a l v a l v a . Thle v a r i a t i o n i n c l u d e s specimens i n which the area i s moderately concave, v e r t i c a l , and i n c l i n e d forward.  SPIRIFUl  149 Genus TYLOTHIRIS North (n. gen.)  1920.  D e s c r i p t i o n f r o m S t a i n b r o o k , J o u r . P a l . V o l . 1 7 , N o . 5« P» 438. " S h e l l o f medium s i z e t o s m a l l , b i c o n v e x , s p i r i f e r o i d i n shape, w i t h a n g l e s extended t o rounded, g e n e r a l l y w i t h t h e g r e a t e s t w i d t h a l o n g the h i n g e l i n e , s e m i e l l i p t i c a l t o subquadrate i n o u t l i n e . P e d i c l e v a l v e the moreconvex, g e n t l y t o s t r o n g l y c u r v e d from beak t o f r o n t . S i n u s o r i g i n a t i n g a t the beak, deep, i n most c a s e s w i t h a median p l i c a t i o n o r o c c a s i o n a l l y f l a t and n o t p l i c a t e a t t h e b o t t o m . S l o p e s marked b y numerous s i m p l e s t r o n g s u b a n g u l a r p l i c a t i o n s , s e p a r a t e d b y narrower f u r r o w s , and o n l y a few r e a c h i n g t h e beak. Palintrope v a r i a b l e , o f t e n h i g h , n e a r l y f l a t t o s t r o n g l y c u r v e d , h o r i z o n t a l l y and vertically striated; u s u a l l y t h e o u t e r p o r t i o n on e i t h e r s i d e i s h o r i z o n t a l l y marked o n l y . A s t r o n g groove e x t e n d s from t h e beak t o t h e h i n g e l i n e a l o n g t h e immediate margins o f t h e p e d i c l e o p e n i n g . No d e l t i d i u m was observed i n any o f t h e numerous specimens a t h a n d . Beak p o i n t e d , o f t e n e l e v a t e d , i n c u r v e d i n some and n o t a t a l l i n o t h e r s . I n t e r n a l l y the d e l t h y r i a l supporting p l a t e s are s t r o n g l y developed, concave a n t e r i o r l y and t o w a r d the a n g l e s , and extended a s h o r t way f o r w a r d a l o n g t h e f l o o r o f t h e v a l v e . They a r e a l s o s l i g h t l y e x c a v a t e d below t h e m a r g i n s o f t h e p a l i n t r o p e as i n S p i n o c y r t i a . Between t h e d e l t h y r i a l s u p p o r t i n g p l a t e s i s a t r a n s v e r s e s t r u c t u r e v a r y i n g from a c a l l u s t o a t r u e p l a t e concave a n t e r i o r l y and e x t e n d i n g a s h o r t d i s t a n c e f o r w a r d . A t h i n e r e c t median septum e x t e n d s t o t h e m i d p o i n t , where i t generally attains i t s greatest height. B r a c h i a l v a l v e g e n e r a l l y g e n t l y t o moderately convex. F o l d s t r o n g , e x t e n d i n g from beak t o f r o n t , e l e v a t e d , b r o a d l y convex, d e p r e s s e d m e s i a l l y b y a deep s i n u s i n most s p e c i e s , i n o t h e r s t h e s i n u s may be obsolete. S l o p e s marked b y p l i c a t i o n s as i n t h e o p p o s i t e v a l v e . Internally t h e c a r d i n a l p r o c e s s i s subquadrate t o s e m i e l l i p t i c a l i n o u t l i n e , b r o a d l y convex, and v e r t i c a l l y g r o o v e d . The s o c k e t s are deep, narrow and l a t e r a l l y directed. A t h i n s l i g h t median septum i s v a r i a b l y d e v e l o p e d i n most species. E x t e r i o r o f t h e v a l v e s e x c e p t i n g t h e p a l i n t r o p e s marked b y numerous c o n c e n t r i c growth l a m i n a e . The s h e l l s u b s t a n c e i s f i b r o u s and impunctate. Our s p e c i e s d i f f e r from t h e genotype, T y l o t h y r i s l a m i n o s a , i n b u t few d e t a i l s . The m e s i a l septum o f t h e p e d i c l e v a l v e i s n o t as s t r o n g l y d e v e l o p e d and i s h i g h e s t a n t e r i o r l y . The a p i c a l c a l l o s i t y i s n o t as s t r o n g i n most s p e c i e s , and t h e a p i c a l chambers formed b y t h e u n i o n o f t h e c a l l o s i t y w i t h the median septum are v e r y s m a l l . Most o f our s p e c i e s have a m e s i a l s i n u s on t h e f o l d and a p l i c a t i o n i n t h e p e d i c l e s i n u s , b u t one s p e c i e s does n o t and i n o t h e r s t h e r e o c c u r examples i n w h i c h n e i t h e r i s present. These d i f f e r e n c e s seem t o be due t o e v o l u t i o n a r y t r e n d s and  probably are not of generic Genotype:  importance.  T y l o t h y r i s laminosa.  151. Genus WARREJW-T4. Crickmay, n .  gen.  C r i c k m a y , :(l°53)<- Jour. P o l . V o l . 2 7 , N o . k, r  pp.596-600,  "Smooth, r o b u s t , s t r o n g l y umbonate M a r t i n i i d a e w i t h umboral c a l l u s e x t e n d i n g i n a n t e r i o r d i r e c t i o n o v e r much o f the i n t e r i o r * V e n t r a l v a l v e s t r o n g l y convex s u l c a t e l i n e d i n t e r i o r l y w i t h t h i c k , e x t e n s i v e , symmetrically developed c a l l u s . Teeth w e l l developed. D e n t a l l a m e l l a e l o n g , a p p r o x i m a t e s l i g h t l y d i v e r g e n t d y i n g out b a s a l l y i n umbonal c a l l u s . D e l t h y r i u m o f medium w i d t h , c l o s e d b y a s t r o n g , short deltidium. D o r s a l v a l v e convex, u n i p l i c a t e , l i n e d w i t h much c a l l u s . Cardinal process short s a g i t t a l l y s t r i a t e . Hinge p l a t e deeply c l e f t . S o c k e t s l a r g e , deep, w i t h prominent b o r d e r i n g r i d g e s . Spiralia with seven t o n i n e t u r n s . Discussion. S i n c e one s p e c i e s W. F r a n k l i n i i has a m i c r o - o r n a m e n t , i t i s p r o b a b l e t h a t t h i s w i l l prove t o be a g e n e r i c c h a r a c t e r i s t i c , though w i t h o u t v e r y s u p e r i o r p r e s e r v a t i o n i t w i l l n o t be o b s e r v e d . W a r r e n e l l a i s d i s t i n c t from M a r t i n i a w h i c h l a c k s d e n t a l l a m e l l a e , and from M a r t i n o p s i s and M a r t i n i e l l a w h i c h l a c k the e x t e n s i v e i n t e r n a l c a l l u s and such a s s o c i a t e d s t r u c t u r a l m o d i f i c a t i o n s as r e d u c e d d e n t a l lamellae. W a r r e n e l l a i s one o f t h e few D e v o n i a n r e p r e s e n t a t i v e s o f t h i s f a m i l y other genera being M i s s i s s i p p i a n t o Permian". Genotype:  Warrenella eclectea  (Crickmay).  152 OOBECTA  UPPffi DEVONIAN BRACK! PODA  MSfflBBU  "tending aore t a n half way to anterior borders basally In oalius appearing to extend st one stage of dwvwlopwsnt to floor of valval Joined by a transverse structure which beeooee anteriorly the convex surface of the nedlen fore of tbe callus, teeth small. Brachial valve of low convexity. Bsak and dorsal Interarea leaa ooMpiencus than l a other apselas. Paid very lneensplsnoss st a l l stages. Cardinal process prominent with e snail concave crown very deeply end finely s t r i a t a . Sockets s n a i l . Apical callus thick only l a umber a l region extending thinly over Interior wore then half nay to anterior border thinner thsn In sadlsn fore with low square cot walls. Spirslss with seven to eight turns.  10.5 on.  MWRM«fl nfnmSCTL- Crlekmey (X9S3)  fkinanaiMiai wast upper slept of Socks s Pardrle, •uuialilp Uv, Bsnga 21, west of Sth Naridlan, Alberts, Canada) uppermost bed of Plona ferastlon.  Jour. Pal. Vol. 27, No. h. pp. 596-600 ?5 text figs. WARRENEX-A AH1DBCTA (CX-lckmay)  Msaraa of HolotTpa x 2.2  Shall of snail or sub medium siae, smooth, not strongly, nor Tory i m e q n j i t y biconvex. Anterior commissars gsntly uniplleste. Hlnge11ns 521 of total width. Ventral valve gsntly convex, of medium daptb allghtly wider then long. Beek strongly Incurred abruptly tapered, acute regular In aedlan section symmetrical. IDtararss abort not dnllaHad In any way. Daltbyrinn of medium width (60*)| daltldlua very short. Sulcus beginning each anterior to onbo, ineoupleuotts, aha Ilea and of aodsrsts width wren at anterior end. aprteal callus thick.  SCLICTE/  width 23 am.| langth 20 aw.) langth L valve 16 oa,| daptb valves together  3E7CHLU.'  1. 2. 3. b. 5*  Dorsal view Ventral Maw left Lateral view, Anterior view. Posterior view.  WXRPJBZU4  l-UCHIOPCDA  Brachial valve of medium convexity. Beak and dorsal Interarea aonsplououa. fold beginning anterior to umbo, expending similarly to sulcus markedly flaring at anterior end. Cardinal process small round boss l i k e , deeply aid f i n e l y striate bosrdered by greater etrlae. Sockets large boardsrsd by sharp rldgss aplevl callus thick extending one halfway to anterior border) thinner i n a narrow median sons with square cut walla. Spiralla with seven to sight turns. Bolotypei Width 22.5 mm.) langth IB mm.) length or brseblsl valve lb.5 am.) depth (valvea together) l b mm. WA.TRENELLA SCLECTEA - Crickmay (L953) Jour. Pol. Vol. 27, pp. 596-600 Figs. 1 - 5 .  Ocuui'raiiooi Vest upper slops of Kouot Haekensie, Township bS, Bangs 23, wast of Sth Meridian, 'Alberts, Canada) lower bO f t . of Cheviot formation.  WARRENgLLA ELSCTEA (Crickmay)  Diagram of Holotype x 2.2.  Stall of small or sub-medium siaa, smooth strongly but unequally biconvex. Anterior commlasure strongly unlpllcate to faintly paresulcste. Hinge line 7$% of total width.  Pig. Pig. Fig. Pig. Fig.  Ventre! valve strongly convex, deep and wide i n ratio with length. Beak incurved abruptly, tapered, acute, regular in median isctlon symmetrical. Interarea long (2bg of hinge length), not sharply delimited- Delthyrium of medium width, deltidium short. Sulcus beginning immediately anterior to umbo, inconspicuous and shallow in posterior region, expanding end deepening at a rate greater than the normal growth curves. Apical callus very thick extending moro than half way to anterior boarders pieced by small apical and nmnnnal vaults. Dental l a a e l l & a sab parallel ending basally in a rounded arch. Teeth large.  1. Dorsal view 2. Ventral view 3. Left lateral view b. Posterior view 5. Anterior view.  Superfamily Spiriferacea  155*  Genera of the Superfamily SPIRIFERACEA., detailed descriptions of which were not found i n the l i t e r a t u r e . below are taken from Shimer and Shrock  The b r i e f descriptions  (1944),  Genus Ambothyris - not described here. Genus C h o r l s t i t e s - not described here. Genus C r u r l t h y r i s - George  1951.  " ( S p i r i f e r u r e i Fleming). Like Ambocoella. small, hinge narrower than greatest width; ventral umbo incurved; surface smooth to spinose; cardinal process s e s s i l e , elevated, t r i a n g u l a r , tuberculate; dorsal musculature located just anterior to cardinals; scars elongate. Dev.-Perm. (Ohio, Ind.  f  Midcontinent, Tex.)"  Genus C y r t i o p s i s - not described here. Genus C y r t o s p l r i f e r N a l i v k i n  1918.  Genotype: S p i r i f e r v e r n e u i l i Murchison. Generally medium-sized s h e l l s , often very wide, with costate f o l d and sulcus; dental plates strong; spire attached t o socket plates; no supporting lamellae under socket p l a t e s . U. Dev. (Chemung-Oonewango) (N.Y., Appalachians, Ia., Mont.; Mackenzie Valley; Canadian Rockies; Great Basin.) Genus Elvtha Fredericks  1918.  Genotype: Delthyrla flmbriatus Conrad. Transversely e l l i p t i c a l i n outline; biconvex, valves subequal i n depth; costate, with low rounded costae crossed by distant lamellae bearing one row of long double-barreled spines; ventral valve with strong dental plates and median septum; dorsal valve with strong socket plates supported by short septa; no median septum. Dev. (Hamilton) (N.Y., Appalachians, Mich., Ohio, Ind., Ky., Ia., Great Basin; Mackenzie Valley.) E. flmbriata Conrad. Hamilton and T u l l y . Appalachians, Mich., Ind., Ky., Term., 111."  Ont.;  N.Y.,  Genus Martinia - not described here. Genus Martinopsis Waagen  1885.  Genotype: M. i n f l a t e . Shells of about medium size with smooth exterior; a shallow ventral sulcus and low dorsal f o l d ; beak strongly incurved; delthyrium covered with a deltidium; ventral  15*-interior with long dental plates, H. Dev. (Ont., Ohio. Nev.). Genotype.  "M mala Billings. 8  Genus Beticularla - not described here. Genus Tenticospirlfer Tien 1958 Genotype: Spirifer tentloulum Verneuil. Small spiriferoids with fold and sulcus costate; ventral valve hemipyramidal and with long dental plates. U. Dev. (Ia., Mont., Wyo., Utah, Nev.).  155 TJ??SR OBJOni/m HRACKIOPODA  (HJHRA var. HEVAD3ISIS  not? no  Betesi This v a r i e t y d i f f e r s froa t y p i c a l spec loan* of S(H.) glehrs in having the greatest transverse diameter higher up on the s h e l l end the n e s l a l f o l d and sulcus nora usually angular. It ajeo averages s n a l l e r in l i z e , the largest s;«einsr, hrvlr.g s height of iX am. a br'.ndth of 38 rr.. v.-i %Y.<i ev»rog. .beet 2 $ Taa. by 3 0 am. Locality! SPIRIFa (H.)GLA3RA var.  OTHgHalS  j'pper Devonian uirestcr.e, iureka J l s t r i e t , Nevpda.  Diagrams!  whleott. P a l . of the Eureka D i a t r i e t U.S.rj.S. Kon. P.. I831t. MARTINA GLAERA var. N57A0ENSIS (Walcott) Description! The range of v a r i a t i o n i s considerable, the specimens d i f f e r i n the strength and angularity of the mesial f o l d and sinus. The depression along the middle of the mesial f o l d .TOT he strong, cr e n t i r e l y absent, even i n large sised specimens.  fig. fig-  1. )Dorsal views. 2- )  Pig. Fig.  U.  3.  Side view. Anterior ilew.  Seme s h e l l s --.re also much more transverse than others and the r e l a t i v e length of the hinge l i n e v a r i e s . The'scrfeee i s usually smooth, owing t o the condition o f preservation o f tbe s h e l l . Examples ahow, however, ttuvt i t was marked i n some instances by obscrue rediatlr» p l i c a t i o n s concentric s t r i a e 1 mm. d i s t a n t , also f i n e rwttstlng interrupted s t r i a e . These vnry and ir. some s h e l l s are e n t i r e l y absent.  UHU  MAhTIslA  UPPBt DEVOIZAJ BMACHIOPOflA  (Oeoxge, 1937, p . 110)of e b l c b , • a r t i c l e g l a b r a ( M a r t i n ) , shows an e n t i r e m e s i a l and, according to George, doe a not have d e n t a l p l a t e s - Resembles T i n g e l l a Orabau but doea not ahow oreni anuiateo a a r found i n T l n a g l n a of growth l a m eH l l a es found g ^ j T ' ^ P ^ f ^ f f ^ B Orabau. B o r a a T v a l  l|Tllrifl>  a a r r l a a 1940, 1, V e n t r a l v i a e of paratype, a l l g h t l y reduced, a, Doraal v i e s of h o l o t y p e , e l l g h t l y reduced. 3 , 4, Doraal and l a t e r a l vlewe of paratypee, a l l g h t l y reduced. MART IB IA EIREI UZBI  Mer t i n t s mm Merriam 1940, d e a l . Boo. of A s e r l c a S p e c i a l Papere Bo. MS, p. 85, p i . 0, f i g a . 36-49. S h e l l o f medium e l s e , width about B / l O t h a of l e n g t h , i n aome I n d i v i d u a l s equal to or exceeding l e n g t h . S h e l l deeply b i c o n v e x , c o n v e x i t y o f v e n t r a l valve g r e a t e r than t h a t of d o r a a l . v e n t r a l valve w i t h w e l l - d e f i n e d median eulcue extending f r o a t i p of umbo t a eoamlaeure. Doraal valve f r e q u e n t l y snowing a r e t h e r broad f o l d whioh l a d i v i d e d by a aedian eulcue. Doreal f o l d and aedlaa s u l c u s may be undeveloped i n Immature etagee. S h e l l e i t h e r aaooth or ahowlng f a i n t r a d i a l a t x l a t l o n a , p a r t i c u l a r l y on s u l c u s . o f v e n t r a l v a l v e . Axee o f a p i r a l l a appear to be a l a o a t p a r a l l e l to hinge a a r g l n , not i n c l i n e d p o a t e r l o r l y as i n B e t l c u l a r l a . Dent a l p l a t e e are w e n developed. V e n t r a l auecle s c a r e narrow. Thle f o r a l a p r o v l a l o n a l l y placed l a the genus M a r t i n i s M'Coy, the genoleototype  and Tlinnggeellllaa Orabau i n absence or e e p t a . t l n i a novadenals ( t a l e o t t ; l a more transverse and has moro ex tenet ve c a r d i n a l a r e a . May be o e n e p a c l f l c w i t h e p l r t r e r o l d e o f tbe Eurexa d l a t r l o t , r e f e r r e d to M a r t i n i s B i l l i n g s by t a l e o t t . m e n o t o i d e e i r o a the LocXhart R i v e r , • A . ada, l e e o r e rounded In o u t l i n e , w i t h l a e a preolneat v e n t r a l umbo. M. fclrfcl l a s p e c i f i c a l l y d l a t i n o t f r o a •,. h e e l of the Maokentle R i v e r Devonian, Canada, which la haa a l e s s prominent ventral soae ae i n d i v i d u a l s of a i r Ml the d o r a a l ff o l d a u l c of f r a n x l l n i l a d i v i d e d by a s a d l e a aa u a . Measureaenta.— Holotype, width 38 tblcxneee l b length 36 . Paratypea*. width length thloxneae 38.0 aa. 31.0 MS.Oaa. 19.5 mo. 1S.0 a s . MS.Oaa. 3U.0 lo.O 37.00D. Occurrence —  aaia  rranaTTnt alan,  as. as.  156 KAIA  tXPPffi DHVOHIAN EBACHTOPQDA  RAH? IDA  F.C*  3PBIFE3 HAM (Hall  1867)  v.Hall, Hat. Hist. Nov 'or*. V o l . VI, p. Ul6. SPmrrsR XAM Doacrlptloni Shall below medium generic aize ventrlcoss with rounded eordinal angles giving n longitudinally cv-Ue outline v i t h depressed suh-gluhose form) hinge lL-.e very short) cardinal orea narrow and sometimes hidden by boaV. Dorsal valve sub orbicular moderately ventrlsoae with a d i s t i n c t l y elevat-ri rounded .-MSlal f o l d . Ventral val^e more ventrleose than the opposite with .1 large tumid Incurved heak and a moderate sub angular mesial sinus. Surface deatltude of p l l c a t i o r s hut mar Ved by more or less dentinet striae cf growth. Zoological r c r w t l o n i Ccralferous limestone of Ohio and Canada west.  Pig. *i«. Fig. Fig.  1. 2. 3. u.  Dorsal of an elongate specimen. Ventral Profile . Front view) OPPEH lUtVUNlAH BRACRTAPCDA  SOBLJBBMTUS  SPIRITS! Kartlaia  traces of a mesial fold| beak small, projecting little beyond tba cardinal margin) area small. Ventrd valve twice or three times ss convex es theother, and without a mesial slnusj ares triangular, moderately high, not very sharply defined) foramen triangular, higher than wide, unclosed in all ths spselmsns examined. Surface very nearly smooth, but snowing, under e magnifier, feint traces of very fine concentric striae, and obscure Indications of radiating lines. Internal casta of the ventral valva with s faint furrow extending along the mlddla, an each side of.which there is a shallow, flat Impression, extending tram the '"ft^yt region to each antero-lstoral margin. Breadth of a large Individual, 0.62 inch) length, 0.60 Inch) convexity, 0.3li inch.  Lake. Diagram Trans. Chic. Acad. Sol. 1867-9. p. 103.  Vol. 1.  SPIRjm(inRTTiriA)3u3LrmTuS Meek Shall small, subcircular, or truncateorbicular, moderately convex in adult speoiasnai lateral margins rounding gradually into tha more or lass regularly roasted front, end more abruptly into the ehsrt hlngsj cardinal margin considerably shorter than tba greatest breadth of tba valves. Dorsal valve snbsemlolreulsr, rather compressed and without any  C o m in the dark hltnmlnous llmestccs, near vtlon, on tbe sooth elds of the Oreat Slave 1. sine view 2. Dorsal view 3. Ventral view of east.  -157  CTRTIHIFORRIS  DEVONIAN BR/CHIOPODA  TBnTICOSPIRIFEB  Brachial valve slightly convex, the greatest convexity being i n the nrnlwmsl region; tbe surface l a evenly arched i n the central portion of the valve, and slopes evenly to a l l margins. As indistinct medial fold originates at tha mid-length of the valve, and projeoto forward to form a moderately prominent rounded ridge. TKMTUXSj'myKR ClRTiNlFOHMIS Ball and Whitfield Coopar, 19a7, l a Index Fossils of North America, p. 321, p i . 121, figs. ul-W». TBsTICOSPIRIPffi CTjrTDJIPQHHIS Ball azsBfilltflald Description! Shall aaall, alder than long, eutaaagathyrld, cardinal extrezdtlea angular. Dimenelonsi lasgth 12.8 an, width 1U.8 na, thlekneas 9.7 mm. Pedicle valve E n r a a l d a l , the surfac* aloplng evenly to tha lateral aargina end curving slightly to the anterior margin. Tha media sulcus originates a t the beak, eortmndo forwards ae a shallow depression broadening to the front margin. Beek pointed, very slightly to aodarately Incurved; cardinal area about teo thirds aa high aa wide, nearly f l a t and marked by fine vertical atraiae. Delthyrlnm shout three times as high aa wide.  UTARXBBI8  4  The surface of both valves l a ornamented by s series of lew rounded plications, about tan of these restricted to the sulcus and fold, and the lateral slopes bear from 16-18. Ou-utieucei Cheviot Format ton (Mount Bask member; In eastern rouges ofRocky Mountains near Berdegg, Alberta. Diagrams! 1. Ventral vies. 2. Dorsal view. 3- Posterior view. It. Lateral view.  UPPER DEVONIAN BRACHIOPODA  5  6  B l r l f e r utahenela Meek 1877, p i . I l l , I l g a . , 1. a, 1 b, 1 c, 1 d, l e. 1, A n t e r o - v e n t r a l ?view, n a t u r a l s i z e , d, Doreal view of ease  epeoimen. 3, 810e v i e s of smaller specimen. 4, C a r d i n a l view of another specimen, shoeing area end foramen. S, C a r a l n a l v i e s o i the v e n t r a l valve o i tne l a r g e s t specimen eaen. 6, Antero-ventral view o l same. SPIHIFKH UTAH EN 318 B o l r l f e r utahenela Meet 1B77, Part I , Paleontology U. 8. Oeol. E x p l . 40 th Par. (King) Vol. 4. D. 39, p i . I l l , I l g a . 1-1 e.  S h e l l small, l n e q u l v a l v e , convex, eoaetlmee aubpyraaldal, w i t h o u t l i n e forming r a t h e r more than a o r o l c l r c l e . Length about 1/4 to a/3 the breadth. L a t e r a l e x t r e m i t i e s obtueely angular. V e n t r a l valve e l e v a t e d a t umbo, and a l o p l n g o f f a b r u p t l y to the f r o n t ana l a t e r a l margins, with u s u a l l y a a l l g h t l y convex o u t l i n e , e s p e c i a l l y on tne a n t e r i o r alope, aometlaea with one of the l a t e r a l alopaa concave i n out-  SPInlFEH  l i n e p o s t e r i o r l y . M e s i a l sinus ahailow, narrow, rounded w i t h i n , and extended to aoei o f beak. Beak e l e v a t e d , abruptly pointed, and ellgn'.ly arched. Area nlgn, or e i t n n e l g n t equaling about h a l f l i e breadth, t r i a n g u l a r , and continued to the e x t r e m i t i e s of the hinge, w e l l - d e f i n e d or angular, l a t e r a l s l o p e s , ranging a t about r l g b t anglee to tbe place of tne s h e l l , and u s u a l l y a l i t t l e arched. Foramen p r o p o r t i o n a l l y very narrow, ax some t i n e a twice ae high ae wide. Doreal valve much depressed, or but modera t e l y and evenly convex. Beak email, l n a l a t l n c t t r o a c a r d i n a l margin, aomevnat i n c u r v e d . Area merely l i n e a r . M e s i a l f o l d depreeeed. Suriace o l each valve marked by 30 to 40 e a a l l almple, r a d i a t i n g coetae, or s t r i a e , b to 10 of which occupy tne mesial s i n u s , ana about aa many the mealal f o l d , where tney sometime* bifurcate. In general form, as w e l l aa i n I t s h i g h , large area, i t has more the apect of a C y r t i a or C y r t i n a than of a T r l g o n o t r e t r e . But as none o i tne specimens snow any i n u i c a d o n e o l the loremen oeing c l o a c a oy a l a l a e a e i t l oium, or o i a punctate s t r u c t u r e , I nave p r e l e r r e d to r e f e r I t p r o v i s i o n a l l y to the t y p i c a l s e c t i o n of the genue S p l r l i e r . Occurrence.—Rare i n tne Ensnae anule.  0PPE8 BETOHIiH BBACHIAFODi  COMPACTUS  &rijLiraa  projecting a l i t t l e beyond the hinge l i n e , aad rather distinctly Incurved over i t s narrow cardinal ares. Ventral valve most gibbous i n ths rmtwjnsl regloni beak rsxtsdaent sod distinctly Incurved) mesial sinus moderate, extending to the bosk, rounded or vary f a i n t l y subangular, widening gradually forward wltboct very distinctly defined margins to ths front, where i t terminates i n e semicircular projection, f i l l i n g a corresponding recess i n the margin of the other vslvej area moderately high and arching with ths beak, rather well defined, but without angular margins, and marked by distinct transverse atrlaa, crossed by very mlr.ute vertical lines) foreman presenting nearly ths form of an equilateral triangle, or rather higher than wide. Surface with about nine to ten simple, rounded, rathar depressed castas on each aide of themealel f o l d and sinus, and numerous fine, very regularly snenged, equal uruadod concentric etrlae, which err regularly arched l a crossing ths ribs, under s good magnifier, on protected portions of wall preserved epscixsKcs, traces of extrnaaly small radiating etrlae, apparently pruduued by regularly disposed grsoulss, ary else be BrTRIFBB CCHPiCTCS Meek (1869) Tnna. Chlo. Acad. Sol. Vol. 1. 1867-9, p. 102.  SnRPBB  C0MP»CTD3 Meek  Shall subglobose, a l l t t l a wider than long, greatest transverse diameter usually st B O B point betsasn tha middle end the cardinal margin) Blags l i n e euuallng about two-thirds ths greatest breadth of the valves) l s t a r a l margins scarcely ever even obtusely angular at their ccmsctlons with the hinge, but rounding regularly into tha front, which i s snrnntlmns very faintly sinuous at the termination of ths mesial fold. Dorsal valve rather gibbous, but s l i t t l e less so thsn ths vantralj mesial fold rounded, depressed or moderately prominent, and without coetae) beak  length of e medium slsed specimen, 0.90 Inch) breadth, 0.96 inch) convexity, 0.70 inch) breadth of mesial fold and sinus of ths front, C I S inch. Same specimens are proportionally pore gibbous. i  Locanart river, l a t . 67 deg. 65 min. B. dag. U.  159.  SUperfamily Terebratulacea  ( S h r o c k and T w e n h o f e l , p . 332)  T e r e b r a t u l a c e a n s are endopunctate a r t i c u l a t e s w i t h a l o o p l i k e b r a c h i d i u m , w i t h hinge p l a t e s or a c a r d i n a l p l a t e i n the b r a c h i a l v a l v e , w i t h o u t a n o t o t h y r i u m o r c h i l i d i u m , and w i t h the d e l t y r i u m u s u a l l y more o r l e s s r e s t r i c t e d b y d e l t i d i a l p l a t e s . Range:  Lower S i l u r i a n t o R e c e n t .  Genera D e s c r i b e d :  Range:  I . Genus Cranaena H a l l and C l a r k e II.  Genus C r y p t o n e l l a H a l l  Middle Devonian t o M i s s i s s i p p i a n . Devonian  I I I . Genus R e n s e l a n d i a H a l l "  M i d d l e Devonian  17. Genus S t r i n g o c p h a l i s Defrance  Middle Devonian  Reported occurrence of t h i s superfamily i n the l i t e r a t u r e reviewed i n Part I of t h i s t h e s i s . I. II.  11, 32, 37.  Genus Cranaena H a l l and C l a r k e . Genus C r y p t o n e l l a H a l l C a l v i n i H a l l and W h i t f i e l d .  I I I . Genus R e n s e l a n d i a H a l l *  R. leavis  Meek.  2  33« 1, 30, 37.  17. Genus S t r i n g o c p h a l i s D e f r a n c e . S. b u r t e n a D e f r a n c e .  2, 12, 30, 33, 3U, 37.  6, .8.  160. Genus CRANAEHA Hall and Clarke, n. gen.  1893  This description i s taken from Cloud, P.E., Geol. Soc. of Am. Special Paper No. 38, p. 132. "Diagnosis: Shell small to moderately large, smooth, terebratulifcrm. Pedicle foramen typically permesothyrid. Cardinal plate free and perforate. Loop short, consisting of simple lateral bands joined by a short, posteroventrally recurved transverse band. Median septa absent. Dental plates present. General Characters: Shell smooth or marked by growth lines only, ranging in length from less than 10 mm. to about UO mm. and in proportion from longer than wide to subcircular or, rarely, to wider than long, subequally biconvex with ventral valve the deeper. Ventral sulcus and dorsal fold present or lacking, or a sulcus may be present without a fold. Anterior commissure rectimarginate to sulcate, entire to emarginate. Lateral commissures rectimarginate to sinuate. Cardinal margin terebrat u l i d . Beak long or short, suberect to incurved. Foramen typically permesothyrid (rarely mesothyrid) commonly marginate or labiate. Deltidial plates conjunct, plane or slightly convex externally, punctate. Ventral valve with short but well-developed dental plates. Muscle f i e l d long and narrow, individual marks not clearly separable but seemingly divisible into narrow linear adductor scars in the center, bounded latera l l y by longer and larger diductor impressions. Dorsal valve with a cranaeniform loop as described for the subfamily and a free, perforate cardinal plate. The apex of the cardinal plate, behind the dorsal foramen, occasionally.displays a pair of small, faintly rugose, myophore surfaces, presumably the diductor impressions. Muscle f i e l d narrow and elongate and muscle pattern ordinarily indistinct. %ere marks of individual muscles are distinguishable a pair of small, subovate, medial adductor impressions can be seen lying at the anterior ends of muscle tracks which are offset a b i t from the center of the valve by a pair of medial p a l l i a l trunks, a second pair of somewhat obliquely elongate, linear adductor scars l i e s outside the f i r s t pair, bounding i t laterally with i t s anterior ends. Myophragm present or absent. Comparison: Cranaana has been confused with Cryptonella but the two genera actually differ widely in characters of the loop and in features of the beak and pedicle foramen. The beak of Cryptonella i s relatively long and straight to nearly straight or scarcely suberect, whereas that of Cranaena varies from distinctly suberect to so strongly incurved that the deltidial plates are concealed. The pedicle foramen of Cranaena i s almost invariably permesothyrid and commonly marginate or labiate. In Cryptonella on the other hand, the foramen i s submesothyrid, telate or partially att r i t e , with an unthickened margin, and knicks a small V-shaped re-entrant in the ends of the conspicuous, long, conjunct deltidial plates. Internally the long and complex loop of Cryptonella contrasts strongly with the short and simple loop of Cranaena. The pattern of the ventral muscle f i e l d of  161. Cryptonel 1 a i s generally s i m i l a r 'to that of the Centrcnellidae and i s possibly more primative than the l i n e a r arrangement found i n Cranaena; the dorsal muscle f i e l d s i n the two genera are s i m i l a r i n general but d i f f e r i n that the anteromedial adductor scars of Cryptonella are r e l a t i v e l y l a r g e r and closer to the middle of the valve than i n Cranaena* Important i n t e r n a l d i s t i n c t i o n s e x i s t between Cranaena and Hamburgia, Dielasma, Beecheria, G i r t y e l l a , Septothyris, and "Harttella"» Hamburgia has an a p i c a l l y s e s s i l e , imperforate, cardinal plate; Dielasma~and Beecheria have imperforate, s e s s i l e c a r d i n a l plates; G i r t y e l l a , Septothyris and " H a r t t e l l a " have imperforate c a r d i n a l plates supported by median septa; .dental plates are absent i n " H a r t t e l l a " and obsolescent i n Beecheria. The only other genera needing comparison are Dielasmoides and Dielasmella; Dielasmoides has a t y p i c a l l y s u l c i p l i c a t e e n t e i i o r commissure and apparently discrete hinge plates. Dielasmella i s c h a r a c t e r i s t i c a l l y a much compressed s h e l l with a straight .beak and a low median sulcus bounded by a pair of low f o l d s i n each valve; the range of v a r i a t i o n of Cranaena (see Cranaena praecursor) but d i f f e r s from most species of that genus i n that the dorsal foramen i s proportionately large and the median portion of the c a r d i n a l plate i s very short, while the socket bases subtend r e l a t i v e l y large angles with the p o s t e r o l a t e r a l margins and a r e l a t i v e l y «m»n one between themselves." Genotype: (by subsequent designation of H a l l and Clarke, 18°U, Terebratula romingeri Hall,7 1863. Range:  loc. cit.)  Devonian and Mississippian (rocks of Onondaga or Oriskany age to at l e a s t as high as the Spergen limestone) of North America. In the r e s t of the world the range i s l e s s c e r t a i n , f o r Devonian species probably assignable to Cranaena have been c a l l e d Cryptonella or Dielasma. The genus i s d e f i n i t e l y present i n the Devonian of Europe and perhaps ofAsia, A f r i c a , andSouth America as w e l l .  162. Genus CRYPTONELLA Hall 1861 n. gen. Description in Cloud, P.E., Geol. Soc. Amer. Special Paper No. 38. p. 127. "Diagnosis: Shell small to moderately large, ter ebr at ul i f or m. Test commonly unornamented but faint costellae may occur anteriorly. Pedicle foramen submesothyrid. Cardinal plate free, loop cryptonell iform; dental plates present. General Characters: Cryptonella ranges in size from C. attenuata the adults of which average about 10 mm. in length, to C. planirostra, large specimens of which may exceed 30 mm. in length. Shell subequally biconvex; outline subcircular to elongate-subpentagonal to lozengeshaped, profile commonly depressed sublenticular. Anterior commissure rectimarginate; margin subtruncate, rounded or emarginate. Lateral commissures rectimarginate;. lateral margins rounded or with posterolateral portions straight and defining a wedge-shaped beak. Cardinal margin characteristically terebratulid. Beak straight to nearly straight or barely suberect, Pedicle foramen submesothyrid, margin unthickened and telate or somewhat attrite. Deltidial plates conjunct, prominent, having a re-entrant knicked into their apices by the base of the foramen. Shell ordinarily lacking ornamentation except for growth lines, but in Cryptonella melonica individuals which are marked anteriorly by a rather numerous, simple, faint, radial costellae are not uncommon. This i s not a feature of exfoliation or the impressions of p a l l i a l sinuses, for the costellae occur on well-preserved shell surfaces as well as exfoliated ones. Ventral interior with well-developed dental plates terminating in moderately strong hinge teeth. Muscle f i e l d one-third to one-fifth as long and one-third to one-fourth as wide as the valve; consisting of a pair of moderately small sub ovate diductors scars lying at the front end of elongate muscle tracks and bounding the posterolateral edges of a small subovate, scarcely divided adductor scar. A low and narrow myophragm i s commonly present. A pair of impressions of radial main p a l l i a l trunks extend anteriorly from the ends of the diductor scars while a second pair bound the sides of the muscle f i e l d and extend forward from there. a  In the dorsal valve the cardinal plate is free, perforate, and unthickened. Muscle f i e l d from one-fifth to about one-third as long and one-fifth to one-fourth as wide as the valve. It consists of narrow, elongate, posterolateral adductor scars offset nearly twice their width from the center and bounding anteriorly a pair of obliquely subovate, anteromedial adductor impressions whose posterior ends nearly meet at the center of the valve. These anteromedial scars are larger and broader but commonly not so long as the posterolateral ones. One pair of traces of main p a l l i a l trunks extends anteriorly from between the muscles near the middle of the valve and a second pair bounds the lateral edges of the muscle f i e l d * Myophragm commonly present. Loop described under C. planirostra.  165 Comparison: From a l l known genera except Cryptacanthia. Cryptonella differs i n the combination of i t s cryptonelliform loop, free and perforate cardinal plate, submesothyrid foramen, and straight to slightly suberect beak. Cryptacanthia differs i n i t s snail size, i t s gibbous shape with depressed dorsal and strongly convex ventral valve, i t s dorsal sulcus and ventral fold, and probably i n Internal details. A detailed comparison with Cranaena will be found under the discussion of that genus." Genotype (by subsequent designation of Hall and Clarke, 1864, op c i t . , p. 861): Terebratula rectirostra Hall. Range: Lower, Middle and probably Upper Devonian of North America. Outside of North America i t i s known from the Lower Devonian and possibly higher strata i n Europe. Other reported occurrences uncertain.  164. Genus RENSSELANDIA H a l l , 1 8 6 7 , n . gen. I n C l o u d , P . E . , G e o l . S o c . o f Am. S p e c i a l Paper N o . 3 8 , p . 9 4 . " D i a g n o s i s : Biconvex Rensselandiinae o f elongate-subovate or subcircular outline. C a r d i n a l margin s u b t e r e b r a t u l i d t o submegathyrid, a n t e r i o r commissure c o n s i s t e n t l y r e c t i m a r g i n a t e . Hinge p l a t e s d i s c r e t e , not supported by c r u r a l p l a t e s . Loop v e r y l o n g , o r d i n a r i l y more o r l e s s widened a n t e r i o r l y , w i t h or w i t h o u t a l o n g o r s h o r t v e r t i c a l p l a t e o r p r o c e s s p r o j e c t i n g backward from t h e median a n t e r i o r p o r t i o n . D e n t a l p l a t e s o b s o l e t e o r o b s o l e s c e n t . V e n t r a l muscle f i e l d shaped l i k e a showshoe w i t h t h e b r o a d end p o s t e r i o r . General Characters: S h e l l s subovate t o s u b c i r c u l a r i n o u t l i n e , subequally biconvex or w i t h v e n t r a l v a l v e the deeper, ranging i n l e n g t h from about 3 5 mm. t o over 90 mm. A n t e r i o r commissure r e c t i m a r g i n a t e . A n t e r i o r and l a t e r a l margins r o u n d e d , c a r d i n a l m a r g i n s u b t e r e b r a t u l i d t o submegathyrid. Beak r a t h e r s h o r t t o l o n g , s u b e r e c t t o i n c u r v e d . D e l t i d i a l plates small, l i n e a r , discrete. P e d i c l e foramen m e s o t h y r i d , t e l a t e t o somewhat a t t r i t e . O r d i n a r i l y l o w v e n t r a l p a l i n t r o p e s , e a c h about h a l f as w i d e as t h e c a r d i n a l m a r g i n , are p r e s e n t but a n a r r o w t r u e i n t e r a r e a may d e v e l o p . A d o r s a l p a l i n t r o p e o r a narrow d o r s a l i n t e r a r e a may be p r e s e n t . S h e l l s u r f a c e t y p i c a l l y smooth e x c e p t f o r g r o w t h l i n e s , b u t the a n t e r i o r p o r t i o n s o f some v e r y w e l l - p r e s e r v e d s u r f a c e s are r a d i a l l y capillate. D e n t a l p l a t e s o b s o l e s c e n t , h i n g e t e e t h s t r o n g and m e d i a l l y i n c u r v e d . V e n t r a l muscle f i e l d e l o n g a t e l y s u b p y r i f o r m , r e s e m b l i n g i n o u t l i n e a snoxv-shoe w i t h the b r o a d end p o s t e r i o r . A n a r r o w , e l o n g a t e , u n d i v i d e d or s c a r c e l y d i v i d e d adductor i m p r e s s i o n forms the a n t e r i o r end of the muscle f i e l d , w h i l e the p o s t e r i o r end i s composed o f a p a i r o f b r o a d e r , subovate d i d u c t o r s c a r s commonly d i v i d e d by a myophragm. Impressions of p a l l i a l sinuses i n r a d i a l p a i r s . Hinge p l a t e s d i s c r e t e , v e n t r a l l y concave, e x t e n d i n g f r e e a n t e r i o r l y from p s t e r i o r m a r g i n . D o r s a l muscle f i e l d s u b t r a p e z o i d a l , m o d e r a t e l y l a r g e , and d i v i d e d b y a myophragm. I t i s composed o f a s i n g l e p a i r o f c o n s p i c u o u s , s u b t r a p e z o i d a l or somewhat e l o n g a t e l y s u b r e c t a n g u l a r , r a d i a l l y s t r i a t e d adductor impressions l y i n g i n f r o n t of a p a i r of l o n g or s h o r t , smooth muscle t r a c k s . Impressions of p a l l i a l trunks i n r a d i a l p a i r s . Loop l o n g and m a r g i n a l . C r u r a v e r y s h o r t w i t h g r e a t e s t w i d t h h o r i z o n t a l , t y p i c a l l y e x p r e s s e d as a s i m p l e n a r r o w i n g o f the h i n g e p l a t e s . The c r u r a g i v e r i s e , b y abrupt d o r s o l a t e r a l g e n i c u l a t i o n , t o the main bands o f the l o o p , and t h e c r u r a l p o i n t s are s i m p l y the f l a t - l y i n g , a n t e r i o r p o i n t s at the place of g e n i c u l a t i o n . Main bands o f l o o p f o l l o w p o s t e r i o r b o r d e r from c r u r a t o p o s t e r o l a t e r a l c o r n e r s and t h e n c u r v e around p a r a l l e l t o l a t e r a l b o r d e r s , t w i s t i n g a t t h e same t i m e , so t h a t t h e i r edges become r e v e r s e d and the one t h a t s t a r t e d on t h e i n s i d e comes t o l i e on the o u t s i d e . The l o o p c o n t i n u e s a n t e r i o r l y , j u s t d o r s a l t o  165. plane commissure and a short distance inside s h e l l margins, f o r twot h i r d s cr more the length of the valve. O r d i n a r i l y the main bands curve somewhat ventrad and p o s t e r i o r l y before they meet, and quite commonly they are somewhat widened t o form a subhorizontal transverse plate. A v e r t i c a l plate or process may r i s e on v e n t r a l side of transverse plate at point of suture and extend p o s t e r i o r l y f o r a greater or l e s s distance. Whether the complete loop i s subcircular or subovate i n outline depends on the shape of the s h e l l that bears i t . Comparison: Family and subfamily characters w i l l delimit Rensselandia from Rensselaeria and Amphigenia. Within the subfamily Subrensselandia i s distinguished from Rensselandia by thepresence of c r u r a l plates, while Chascothyris d i f f e r s i n being a t y p i c a l l y transverse s h e l l with v e n t r a l sulcus and dorsal f o l d . " Genotype: (by subsequent designation of Schuchert, 1879, p. 271) Rensselaeria ? johanni = Rensselandia johanni H a l l , 1867, l o c . cit. Range:  Middle Devonian of North America (post Marcellus beds) and Europe (Stringocephalus zone). LAE7IS  RJHSSELiEBU  UPPEK DETOHIAH BRACHIAPQDI  valve a l i t t l e lea convex than theotheri beak Incurved. Ventral valva most convex somewhat behind the middle: beak small, moderately prominent, and closely carved over that of the opposite valvaj foramen small. Surface smooth, with a few varyobsour. traces of ridges of growth. Same of the specimens also ahow, under e magnifier, very faint Indications of radiating striae, but i t i s not clear that they are surface markln-a. Length of medium alaed adult specimen, 1.77 inches) breadth, 1.13 inches] convexity about 1.10 Inches. Smaller apaelaana proportionally lass convex.  BBNSSgLABtla LAS? 13 Meek (1869) trans. Chic. Acad. S c i . Vol. 1., 1867-0, p. 108. BBSSSELA3IA LA27IS Meek Shell rather above medium sise, longitudinally ovate or subelliptlc In outline, moderately convex In young examples, and very gibbous in adult specimens; frcnt generally rather narrowly rounded; lateral margins forming broad semi ovate or aeaie l l l p t l c a l curves, not Inflected. Doreal  [  Locality and poaltloni Onion river, 1st. 67 deg. id., long. UU deg. M., and forty miles below Good I Hops, Heckensle river, l a t . 65 deg. 50 min. a., | long. 130 W.j also Lockhart river, l a t . 67 deg. ' 15 min. N . , long. 126 deg. W. Ihe specimens are a l l casts, in a hard, gray dolamitle rock, breaking with a rough. Irregular fracture, aad presenting s harsh granular appearance, that might at a glane., cause i t to be mistaken far s sandstone, cr at any rate for a ailldoua rock. Aa this difrers from the matrix of the other fossils from the same l o c a l i t y , I suspect that this species belongs to s different rock, possibly alder then the Hamilton group. It eeama to be abundant at both local i t les, and i s the only recognisable f o s s i l in the massos collected. Diagram 1. 2. 3. k.  Lateral view. Doreal view. Central view. interior view.  166. Genus STR BIGOCEPHALUS Defrance, n . gen.  1825  T h i s d e s c r i p t i o n i s t a k e n from C l o u d , P . E . , G e o l . S o c . o f Am. S p e c i a l Paper N o . 38, p . 10li. " D i a g n o s i s : L a r g e , sub-globular t o t r a n s v e r s e l y s u b l e n t i c u l a r S t r i n g o c e p h a l i d a e . Beak p r o m i n e n t , d e l t i d i a l p l a t e s c o n j u n c t i n a d u l t s , foramen h y p o t h y r i d , v e n t r a l i n t e r a r e a or p i a n a r e a s p r e s e n t and o r d i n a r i l y w e l l d e v e l o p e d . H a v i n g prominent median s e p t a i n b o t h v a l v e s and a l o n g , r o d l i k e , t e r m i n a l l y b i f i d c a r d i n a l process i n the d o r s a l v a l v e . Hinge p l a t e s d i s c r e t e , not supported by c r u r a l p l a t e s . General Characters: S h e l l r a n g i n g i n l e n g t h from 60 mm. t o over 150 mm. s u b e q u a l l y b i c o n v e x o r w i t h v e n t r a l v a l v e t h e deeper, s u b g l o b u l a r t o t r a n s v e r s e l y s u b e l l i p t i c a l , commonly s l i g h t l y a s y m m e t r i c a l . A n t e r i o r commissure r e c t i m a r g i n a t e t o g e n t l y s u l c a t e o r g e n t l y u n i p l i c a t e . A n t e r i o r m a r g i n e v e n l y rounded or e m a r g i n a t e ; l a t e r a l m a r g i n s rounded; c a r d i n a l m a r g i n s u b m e g a t h y r i d . Beak l o n g , p o i n t e d , p r o m i n e n t , j s u b e r e e t to strongly incurved. P e d i c l e foramen s u b o v a t e , v a r i a b l y h y p o t h y r i d i n position. Delthyrium of a d u l t s h e l l s c l o s e d by conjunct d e l t i d i a l p l a t e s , b u t a h e n i d i u m may be p r e s e n t as w e l l . The d e l t i d i u m , whether o f d e l t i d i a l p l a t e s a l o n e o r i n c o m b i n a t i o n w i t h a h e n i d i u m , commonly has a concave s u r f a c e due t o i n t e r f e r e n c e b y t h e i n c u r v i n g beak o f the d o r s a l v a l v e . V e n t r a l i n t e r a r e a o r p l a n a r e a s o r d i n a r i l y p r e s e n t and w e l l d e v e l o p e d ; d o r s a l p l a i n t r o p e g e n e r a l l y , but not i n v a r i a b l y , present. S h e l l surface c h a r a c t e r i s t i c a l l y uncrmamented e x c e p t f o r growth l i n e s ; b u t some i n d i v i d u a l s , p a r t i c u l a r l y young specimens o f S. d o r s a l i s , are r a d i a l l y eapillate. Punctae o f v e r y s m a l l d i a m e t e r and d e n s e l y crowded. S h e l l substance a p p a r e n t l y i n two l a y e r s ; a very t h i c k inner l a y e r , with component f i b e r s a t a s t e e p a n g l e , and an o u t e r l a y e r about o n e - t h i r d as t h i c k , w i t h f i b e r s a t a s l i g h t a n g l e t o t h e s h e l l s u r f a c e . I n some specimens, a l t e r n a t i n g c o n c e n t r i c bands o f f i b e r s i n t h e o u t e r l a y e r seem t o be d i f f e r e n t l y o r i e n t e d w i t h r e s p e c t t o the l e n g t h o f t h e v a l v e , c a u s i n g a p e c u l i a r e x f o l i a t i o n phenomenon r e s e m b l i n g c o n c e n t r i c c o l o r banding. The v e n t r a l v a l v e l a c k s d e n t a l p l a t e s , b u t t h e h i n g e t e e t h are l a r g e and s t r o n g and are b u t t r e s s e d b y t h i c k d e p o s i t s o f s e c o n d a r y s h e l l . D e n t i c u l a a s s i s t a r t i c u l a t i o n . A prominent median septum i s p r e s e n t , e x t e n d i n g a t l e a s t t h r e e - f o u r t h s t h e l e n g t h o f t h e v a l v e from t h e beak and becoming h i g h e r a n t e r i o r l y . D i d u c t o r s c a r s mark s i d e s o f septum toward i t s h i g h a n t e r i o r e n d , t h e m u s c l e s t h e m s e l v e s a p p a r e n t l y h a v i n g extended p o s t e r i o r l y , and somewhat v e n t r a l l y , from t h e r e t o a n t e r i o r f a c e s o f c l a v a t e l a t e r a l e x t e n s i o n s o f c a r d i n a l p r o c e s s . Wide i r r e g u l a r l y rugose a r e a s o f a d d u c t o r attachment extend from each s i d e o f median septum about halfway t o l a t e r a l m a r g i n s . P e d i c l e tube p r e s e n t o r a b s e n t ; i n some i n d i v i d u a l s i t i s a ponderous h o l l o w p r o c e s s n e a r l y c l o s e d a t t h e a n t e r o v e n t r a l end, p o i n t i n g t o a t r o p h y o f the p e d i c l e . The p e d i c l e a p p e a r s t o have been a t t a c h e d t o t h e b r o a d p o s t e r i o r end o f the median septum. Pallial impressions not d i s t i n c t ; s h a l l o w , i r r e g u l a r d e p r e s s i o n s i n the p o s t e r o -  167. l a t e r a l c o r n e r s o f some s h e l l s c o u l d be o f p a l l i a l o r g e n i t a l  origin.  D o r s a l median septum o f v a r i a b l e h e i g h t and l e n g t h . Compared t o t t h a t o f t h e v e n t r a l v a l v e i t i s o r d i n a r i l y l o w and s h o r t , b e i n g o n l y about h a l f as l o n g as t h e v a l v e and n o t r e a c h i n g as h i g h as t h e h i n g e p l a t e s . I n a specimen o f t h e A s i a t i c S. obesus ( U . S . N . M . ) , however, t h e d o r s a l septum i s n e a r l y t h r e e - f o u r t h s as l o n g as the v a l v e and a l m o s t as h i g h as l o n g , e x t e n d i n g v e n t r a d t o t h e p l a n e o f commissure a t i t s p o s t e r i o r end. The c a r d i n a l p r o c e s s i s a remarkable s t r u c t u r e , r a t h e r s i m i l a r t o that of the T r i p l e s i i d a e . I t i s v e r y long, t h i c k , r o d l i k e , t r a n s v e r s e l y f l a t t e n e d a t i t s v e n t r a l end, and s p l i t i n t o two c l a v a t e e x t e n s i o n s w h i c h f i t on e i t h e r s i d e o f t h e v e n t r a l median septum and n e a r l y meet t h e f l o o r o f the v e n t r a l v a l v e . The g r e a t c a r d i n a l p r o c e s s and median septum almost f i l l t h e space between the h i n g e p l a t e s and t e n d t o c o n c e a l t h e f a c t t h a t they are d i s c r e t e structures. L i k e those o f B o m h a r d t i n a , t h e h i n g e p l a t e s o f S t r i n g o c e p h a l u s are v e n t r a l l y convex and unsupported b y c r u r a l p l a t e s , though commonly"buttressed b y s e c o n d a r y umbonal t h i c k e n i n g . D e n t a l s o c k e t s l o n g and deepj l a t e r a l a c c e s s o r y s o c k e t s r e c e i v e d e n t i c u l a o f v e n t r a l v a l v e . M u s c l e f i e l d about h a l f as l o n g and o n e - t h i r d as w i d e as t h e v a l v e j d i v i d e d b y t h e median septum i n t o a p a i r o f e l o n g a t e l y subovate a d d u c t o r i m p r e s s i o n s somewhat r e s e m b l i n g t h e w i n g s o f a maple seed and l o n g i t u d i n a l l y s t r i a t e l i k e t h o s e o f B o m h a r d t i n a . D i d u c t o r muscle s c a r s borne on f l a t t e n e d v e n t r a l ends o f c a r d i n a l p r o c e s s . I m p r e s s i o n s o f main p a l l i a l s i n u s e s b o r d e r muscle f i e l d and e x t e n d p o s t e r o l a t e r a l l y , b u t f u r t h e r v a s c u l a r d e t a i l i s unknown. The s p i n o s e , m a r g i n a l l o o p o f S t r i n g o c e p h a l u s i s , i n g e n e r a l , w e l l known,j b u t t h e c o u r s e o f t h e c r u r a and the p o s t e r o m e d i a l arms o f t h e main bands i s commonly r e p r e s e n t e d as b e i n g r a t h e r s t r o n g l y i n c l i n e d t o the p l a n e o f commissure and l a r g e l y v e n t r a l t o i t . In at l e a s t one n e a r l y complete l o o p (Y.C.S.-3U93), however, the c o u r s e o f the l o o p i s sLaost e n t i r e l y w i t h i n t h e d o r s a l v a l v e , and no p a r t o f i t i s a t v e r y much o f an a n g l e t o t h e p l a n e o f commissure. F u r t h e r d e t a i l w i l l be f o u n d under t h e d e s c r i p t i o n o f S . b u r t i n i . Comparison: A s p i n o s e m a r g i n a l l o o p , median s e p t a , r o d l i k e c a r d i n a l p r o c e s s , d i s c r e t e h i n g e p l a t e s , and g e n e r a l e x t e r n a l appearance a r e such a unique c o m b i n a t i o n t h a t f o r m a l c o m p a r i s o n would be s u p e r f l u o u s . " Genotype: ( b y o r i g i n a l d e s i g n a t i o n ) T e r e b r a t u l a b u r t i n i = S t r y g o c e p h a l e b u r t i n i D e F f a n c e , 1825. Range:  M i d d l e Devonian o f t h e N o r t h e r n Hemisphere.  CONCLUSIONS  1  5g  #  The concluding remarks of this study are arranged under three headings dealing with the contributions, limitations, and suggestions for further research. General Conclusions. 1.  This thesis brings together for the f i r s t time, faunal l i s t s and  detailed descriptions of some brachiopod fossils reported from Canada, west of the 110th meridian. 2.  Fossil descriptions could be added to this thesis to form a complete  l i s t of Devonian Brachiopod Fossils from Western Canada. 5. The l i s t s and descriptions included here will be of use i n the identification of brachiopod collections at the University of British Columbia. Limitations of this Study. 1.  These l i s t s of Devonian brachiopod faunas are not complete.  The  l i s t s were compiled from forty-one papers only. Hany papers on the Devonian strata of Western Canada were not examined. 2.  A l l the fossils listed have not been described.  5. The question of synonomy of each brachiopod f o s s i l listed here i s not discussed. 4. Varieties of species have not been l i s t e d . 5.  Descriptions listed here are taken partly from older works and may  be limited i n detail. Suggestions for further study of Devonian Brachiopod faunas from Western Canada. 1.  Important Information on the stratigraphic value and geographical  extent of Individual species might be obtained from a study of the stratlgraphlcal palaeontology of these f o s s i l s .  2.  A study of the palaeoecology of these fossils might give informat-  ion on the tolerance of various species to changes of lithological environment. The relative importance of individual species i n a fauna might become apparent from such a study. 5. The author considers that an attempt should be made to systematize morphological descriptions of these br&chiopode.  If the morphological  features of a l l brachiopod species vere l a i d out i n a similar systematic manner, together with photographs and serial sections of the type material, the identification, morphological limits and generic a f f i n i t i e s of individual specieB might be facilitated.  170  SELECTED BIBLIOGRAPHY  References included in this bibliography are of two kinds; important general references on brachiopod f o s s i l s , and papers i n which Devonian brachiopod faunas from other parts of North America are described. This bibliography does not duplicate the references from which the brachiopod descriptions were taken, except where such a reference includes descriptions of other important Devonian brachiopod fossils. This bibliography i s not complete.  It includes only a selection  of t i t l e s on the subject of Devonian strata and brachiopod fossils from North America. An asterisk against a reference denotes that the reference i s not presently in the library of the University of British Columbia. ARBER, M.A. ( 1 9 l | 0 ) . "The Relation of the Valves to the Pedicle in Strophomenid brachiopods." Geol. Mag. Vol. 7 7 . pp. 161-17U. •BELANSKI, C.H. ( 1 9 2 8 ) . "Description of Typical Fossils of the Shellrock Stage." Amer. Mid. Nat. V. of 1 1 . No. 5 - p. 1 9 8 . #BRANSC¥, E.B. ( 1 9 2 0 ) . "The Devonian of Missouri." Missouri Bur. Geol. and Mines. Ser. 2 . Vol. 1 7 . p. 9 9 . BUCKMAN. ( 1 9 1 8 ) . "The Brachiopoda of the Namyau Beds Northern Shan States Burma." Geol. Surv. India Pal. India. New rev. Vol. 3 - Mem. 2 . 1917. CASTER, K.E. ( 1 9 3 0 ) . "Higher Fossil Faunas of the Upper Allegheny." Bull. Amer. Pal. Vol. 1 5 . No. 5 8 . CHADWICK. ( 1 9 3 5 ) . "Faunal Differentiation in the Upper Devonian." Geol. Soc. Amer. Bui. Vol. 1*6. p. 3 0 5 . Includes detailed faunal l i s t s of Upper Devonian Fossils.  171.  CLARKE, J.M. (1907).  "Some New Devonic Fossils." New York State Mus. Bui. 107.  pp. 153-292.  CLOUD, P.E. (19U2). "Terebratuloid Brachiopods of the Silurian and Devonian." Geol. Soc. Amer. Spec. Pap. 38* An excellent monograph on these f o s s i l groups.  COLEMAN, P.J. (1951).  "Atrypa i n Western Australia." Jour. Pal. Vol. 25. No. 5« p. 677A quantitative approach to the identification of the Genus Atrypa i s outlined i n this paper.  COOPER, G.A. (1935). "Evolution of Internal Characters in Classification of the Brachiopoda." Geol. Soc. Amer. Bull. I4I4.. p. 193. An important reference on brachiopod classification. •frCCOPER, G.A. (1937). "Brachiopod ecology and paleoceology." Nat. Res. Council. Rept. Comm. Ecology 1936-1937. pp. 26-55. -COOPER, G.A. (19U2). "Correlation of the Devonian Sedentary formation of North America." Geol. Soc. Amer. Bull. Vol. 53. pp.1729-1793. Correlations of major formations with some references to index brachiopods. COOPER, G.A. (191.2). "New Genera of"North American Brachiopods." Jour. Wash.Acad. S c i . Vol. 32. p. 231. COOPER, G.A. (19Ui)." Phylum Brachiopoda in Shimer and Shrock's "Index Fossils of NcrthAmerica. " Ch. 9. PP. 277-365. New Tork. Wiley. This reference contains a carefully selected bibliography. Generic descriptions are brief, but the photographs are excellent. COOPER, G. A. and WILLIAMS, S. (1935). "The Tully Formation of New York." Geol. Soc. Amer. Bull. Vol. I46. pp. 781-868. *CURRY, H.D. (1931). "The Fauna of theChemung Formation of Southwest New York." Iowa Acad. Sci. Proceed. Vol. 37. p. 257.  172 DAVIDSON, T . ( 1 8 5 8 - 1 8 8 0 ) . "Monograph o f B r i t i s h F o s s i l B r a c h i o p o d a . " P a l a e o n t o g r a p h i c a l S o c i e t y V o l s . 2 and h» A c l a s s i c r e f e r e n c e on the f o s s i l b r a c h i o p o d a . *FENT0N, C . L . ( 1 9 3 1 ) . " S t u d i e s i n the E v o l u t i o n o f t h e Genus S p i r i f e r . " Wager F r e e I n s t . S c i . Pub. V o l . . 2 . p p . U36. " FENTON, C . L . and FENTON, M . A . ( l ° 2 i i ) . "The H a c k b e r r y Stage o f t h e Upper D e v o n i a n . " U n i v . M i c h . o n t r i b . G e o l . V o l . 1. p . 1-260. c  *FENT0N, C . L . and FENTON, M . A . ( 1 9 3 0 ) . " S t u d i e s i n the Genus A t r y p a . 9 Amer.-Mid. Nat. V o l . 12. p . 1. FENTON, C . L . and FENTON, M . A . ( 1 9 3 1 ) . " A t r y p a as a H o r i z o n M a r k e r . " . B u l l . G e o l . S o c . Amer. V o l . Ii2. p .  352-353'  FENTON, C . L . and" FENTON, M.A, ( 1 9 3 2 ) . " O r i e n t a t i o n and I n j u r y i n t h e Genus A t r y p a . " Amer. M i d . N a t . V o l . 1 3 . p p . 6 3 - 7 4 . FENTON, C . L . and FENTON, M . A . ( 1 9 3 5 ) . " A t r y p a d e s c r i b e d b y Clement L . Webster and R e l a t e d F o r m s . " J o u r . P a l . V o l . 9 . p . 369. HALL., J . ( 1 8 5 8 ) . "Geology of Iowa." V o l . 1. P t . 1. Palaeontology. C o n t a i n s o r i g i n a l d e s c r i p t i o n s o f s e v e r a l Devonian b r a c h i o p o d a . HALL, J . and CLARKE. J . M . (1892, l 8 9 u ) . "An I n t r o d u c t i o n t o the Study o f B r a c h i o p o d a i n t e n d e d as a Handbook f a r the Use o f S t u d e n t s . " N . Y . S t a t e G e o l . S e r v . R e p t . 11 p p . 1 3 2 - 2 2 3 , l 8 9 2 j p t . I I . A n n . R e p t . 1 3 . p p . 9&5-1137, 189U. A c l a s s i c s t u d y o f B r a c h i o p o d morphology. HALL, J . ( l B l t f and 1 8 6 7 ) . " N a t u r a l H i s t o r y o f New Y o r k . " P a r t V I V o l . 1 . and V o l . i i . A l b a n y New Y o r k 18U7 and 1 8 6 7 . A c l a s s i c - study o f Brachiopods.  .  HAYNES, W . P . 1 9 1 6 ) . "The Fauna o f t h e Upper D e v o n i a n of M o n t a n a . " A n n a l s of- C a r n e g i e Mus*. V o l . , 1 0 . P t . 2 . p p . 13-5h-  173; KINDLE, E.M. (1909). "Devonian Fauna of the Ounay Lime stone •"' U.S. Geol. Survey Bull. No. 391* KINDLE, E.M. (1912). "The Silurian and Devonian Section of Western Manitoba." Geol. Surv. Can.Sum.Rept. 1919. pp. 2U7-261. Devonian brachiopod faunal lists are included of an area adjacent to that covered by this thesis. LAUDON, L.R. (1931). "A Spirifer disjunctus fauna of Iowa." Iowa Acad. Sci. Proceed. Vol. 37. p. 251. MC EWAN, E.D. (1939).' "Convexity of Articulate Brachiopods as an aid to Identification." Jour. Pal. Vol. 13- pp. 617-690. Includes a key to the identification of brachtopod genera, mainly by means of convexity of valves. MEEK, F.B. (1873). "Descriptions of Invertebrate Fossils of the Silurian and Devonian Systems." Ohio Geol. Surv. o l . 1; pt. 2. "pp. l-2li3. Descriptions and figures of many brachiopod species. v  MERRIAM, C. W. (19U0). "Devonian Stratigraphy and Palaeontology of the Roberts Mountain Region Nevada." Geol. Soc. Amer. Spec. Pap. 25* MOORE, R.C.', LALICKER, C. G. and FISHER, A. G. (19£2). "Invertebrate Fossils." Toronto Mc Graw-Hill. NETTLEROTH, C, E. (1889). "Kentucky o s s i l Shells." Frankfort Kentucky 1889. f  SCHUCHERT, C. (1897). "A Synopsis of American Fossil Brachiopoda." U.S. Geol. Surv. Bull. 87. p. I-46I1. Contains excellent lists of fossil brachiopoda. An exhaustive bibliography is included. *SCHUCHERT, C. and EE VENE, CM. (1929). "Fossilium Catalogue I Animalia." Pars. ti2 Brachiopoda lUO. pp. Berlin. SCHUCHERT and COOPER (1931). "Synopsis of the brachiopod genera of the Orthoidea and Pentameroidea with notes on the Telotremata." Amer. Jour. Sci. Vol. 22. pp. 2 l i l - 2 5 l .  174. SCHUCHERT, C. and COOPER, G. A. (1931). "Brachiopod genera of the suborders Orthoidea and Pentameroidea". Peabody Mus. of Nat. Hist. (Tale). Mems. Vol. 1*. pt. 1. 270 pp. A detailed study on these brachiopods. SHROCK and TWENHOFEL (1952). "Principles of Invertebrate Palaeontology." New York McGraw-Hill. Ch. 9. p. 270. A modern detailed treatment of brachiopod morphology. SIMPSON, G.G. (1953). • "The Major Features of Evolution." New York. Columbia University Press 1953. A comprehensive modern discussion of evolution. SLOSS, L. L. and LAIRD, W.M. (19l*7) . "Devonian System i n Central and Northwestern Montana." Amer. Assoc. Pet. Geol. Bull. Vol. 31. pp. Ili0l*-U*30.  STAINBROOK, M.A. (191*5).  "Brachiopoda of Independence Shale of Iowa." Geol. Soc. Amer. Mem. 11*.  STAINBROOK, M.A. (191+3). "Spiriferacea of the Cedar Valley Limestone of Iowa." Jour. Pal. Vol. 17. No. 5. p. h3&* STAINBROOK, M.A. "(19l»3). "Strbphcmehocea of the Cedar Valley Limestone of Iowa." Jour. Pal. Vol. 17. pp. 39-59. STAINBROOK, M.A. (19U2) A. "Brachiopoda of the Cedar Valley Beds of Iowa Inarticulata Rhynchonellacea and Rostrospiracea." Jour. Pal. Vol. 16. No. 5« p i . 88. STAINBROOK, M.A. (191*2). "The Brachiopoda of the High Point Sandstone of New York." Amer. Jour. Sci. Vol. 21*0. p. 883. STAINBROOK, M.A. (191*1). "Terebratulacea of Iowa." Jour. Pal. Vol. 15. o l . p. 50. v  STAINBROOK, M.A. (19l*0). "Orthid Brachiopods of the Cedar Valley Limestone of Iowa." Amer. Mid. Nat. Vol. 23. pp.. 1*82-1*92. STAINBROOK, M.A. (1938). ; "Pentameridae of the Cedar Valley Beds of Iowa." Jour. Pal. Vol. 19. pp. 723-739.  1 7 5  STAINBROOK/ M.A. (1938). "Atrypa and Stropheodonta from the Cedar Valley Beds of Iowa. Jour. Pal. Vol. 12. No. 3. pp. 229-256. *STOOKY, W. S. (1932). "New Data on the Upper Devonian of Iowa." Iowa lead. Sci. Proceed. Vol. 39• p. 183. #TH0MPS0N, J.A. (1927). "Brachiopod Morphology and Genera (Recent and Tertiary). N.Z. Board of Science and A r t Manual 7. 338 pp., . A classic study in brachiopod morphology. This reference can be obtained on inter-library loan from The University of Princeton. 0  *TIEN, C. C. (1938). "Devonian Brachiopoda of Hunan." Pal. Sin. n. per B. No. 1*. Whole Ser. No. 113. p."95. Includes original descriptions of several brachiopod genera. WHITEAVES, J.O. (1892). "The Fossils of the Devonian Rocks of the islands, shores, or immediate' vicinity of Lakes Manitoba and Winnipegensis." Cont. Can. Pal. Vol. 1. pp. 281-290. A study of Devonian faunas in an area east of that covered by this thesis. WILLIAMS, A. (1953). "North American and European Stropheodontids." Geol. Soc. Amer. Mem. 56. An excellent modern treatment of theStropheodontids.  PLATE  I.  Superfamily Dalmanellacea. Genus Aulacella  Schuchert and Cooper*  A. eifelenBie Verneuil 1,2,  dorsal and ventral views of exterior x 1%.  3 , ventral mould x 2 . Genus Cariniferella 0. carinata  Schuchert and Cooper. Hall.  4, 6*, ventral and dorsal exteriors x l-§. C. danmonti  Yerneuil.  5 Ventral interior x l | . Genus Rhipidomella Oehlert R. vanuxemi  Hall.  7 exterior view of ventral valve x l , 8 dorsal interior x 1. Genus Schizophoria S.  King.  a f f . striatnla  Schlotheiin  9 dorsal view x l . 10 lateral view x 1.  SUPERFAMILY  DALMANELLACEA  PLATE  II.  Superfamily Pentameracea. Genus Cypldula  Hall.  G. occidentalis  Hall.  1=5 Dorsal, ventral, lateral, anterior and cardinal views of a specimen showing plications extending some distance from the margin of the shell x 1. 6-7 Lateral and anterior views of another individual destitute of plications x 1. 8  Enlargement of upper half of the shell showing area and foramen.  Superfamily Strophomenacea. Genus Strophonella.  Hall.  9  Sp.  Ventral view of complete specimen x 1§-.  10  Sp.  Ventral Interior x 1 approx.  PLATE  SUPERFAMILY  PENTAMERACEA  II  PLATE  III.  Superfamily Strophomenacea. Genus Douvillina D. arcuata  Oehlert. Hall.  1. Ventral view x 1%. 2 . Ventral interior x l£. D. subinteretrlalis aeretensls  Kozlowski  5 . Ventral Interior. D. newsomensis Poerste 4. Posterior-lateral and ventral aspects of cardinalia (x J approx.) Genus Douvillanarla D. verlabllis  Stainbrook. Calvin.  5 . Ventral view of hypotype x 2 . 6 . Dorsal view of another x 2 . 7 . Internal view of brachial valve x 2 . Genus Leptaena Dalman. L. depressa  Sowerby.  8. Ventral view x 1. 9. Ventral Interior x 1. Genus Leptostrophia L. magnlflca  Hall and Clarke. Hall.  10. Interior of brachial valve - cast x 1. L. BeckjL 11. Exterior of brachial valve showing exterior corrogations x 1.  PLATE  III (CONTINUED).  Genus Nervostrophla  Caster.  N. rockfordensis  Fenton and Fenton.  12.  Ventral Interior x l£.  15.  Ventral view of complete specimen x 1.  14.  Dorsal interior x 2.  Genus Schnchertella  Girty.  S. Desiderata 15.  Dorsal exterior x 1.  S. Woolworthana 16. Ventral interior x 1. 17. Genus Stropheodonta  Dorsal interior x 1, Hall.  Id.  sp. ventral view of complete specimen x 2.  19.  sp. ventral interior.  20.  sp. dorsal interior.  PLATE C.  IV (CONTINUED)  ambiguata 1, 2, 5 dorsal .ventral and anterior views x la-  Genus Camarotoechia C.  Hall and Clarke.  congregata Contrad A i 5, 6, 7  Genus Etonla  ventral, dorsal, lateral and anterior views.  Hall.  E. medialis  Vanuxem  8, 9, 10. dorsal, lateral and anterior view of a large shell.  PLATE  IV.  Superfamily Productacea. Genue  Devonoproduotus D.  Stainbrook  walcotti Fenton and Fenton 1, 2, 5, Dorsal, ventral and side views x 1.  Genu8  Productella Hall P.  subaculeata 4, Ventral view shows one large spine x 1. 5, Dorsal view x 1.  Genus  Strophalosla S.  King  truncata Hall 6, Interior of brachial valve to show cardinal process x 2. 7,  8 , Pedicle valve ventral and posterior views to show truncation of beak x 2,  Superfamily Chonetacea. GenuB  Chonetes Fischer C. macronata  Hall  1, Pedicle valve destitute of spines. 2, Pedicle valve with divergent spines. Genus Chonopectus C,  fischeri  Norwood and Patten  5, Small pedicle valve with cardinal spines x 1. 4, Pedicle valve with reticulate ornamentation no spines x 2. Superfamily  Rhynchonellacea.  Genus Calvinaria  Stainbrook  PLATE  133  SUPERFAMILY  SUPERFAMILY  SUPERFAMILY  PRODUCTACEA  CHONETACEA  RHYCHONELLACEA  IV  PLATE  V.  Superfamily Rhychonellacea. (Continued.) Genus Hypothyrldlna H.  cuboides  Buchman Sowerby  1, 2, Posterior and dorsal view x 1. Genus Lelorhynchus  Hall  L. sp, 5» 4, 5» 6, Dorsal valves to show gradation i n size x 1. Genus Pugnus  Hall  P. pugnax 7, 9, Ventral and dorsal viewB x 1. 6a. and 7b. anterior views x 1. 10, lateral view x 1. Genus Pugnoldes P.  Weller  ottumwa  White  11 a - k Cross sections of rostral portion of a paratype x 2§. Superfamily Atrypacea. Genus Atrypa A.  Dalman  reticularis  Sowerby  1, 2, Dorsal and lateral views of a gibbons specimen. 5, 4, Dorsal and lateral views of a normal specimen. Genus Gruenewaldtia G.  Tschernyschew  latilingius  Schnur  5, 6, 7» Dorsal lateral and anterior views.  18L  SUPERFAMILY  P L A T E  RHYCHONELLACEA  '4.  I.  mm ^ o. ©  V  ®  <g>  Oc. «A (  Q  0  SUPERFAMILY  Q ATRYPACEA  8*  PLATE 20.  VI (CONTINUED.)  Internal longitudinal view.  Genus Tenticosplrifer T. cvrtlniformls  Tien Hall and Whitfield  2 1 , 2 2 , 2 J , 24, Ventral, dorsal, posterior and lateral views. Genus Tylothyris  North  T. mlssourlensls  Weller  2 5 , 2 6 , Ventral, interior and dorsal exterior x 2 .  PLATE  71.  Superfamily Splrlferacea. Genus Amboeoelia A,  Hall  umbonata  Conrad  1, 2, 3, Dorsal, ventral and lateral views x 1. 4, 5, Anterior of a pedicle and a dorsal valve x 5. Genus Athyrls  McCoy  A.  Hall  cora  6, 7, 8, 9, Dorsal, lateral, ventral anterior views. Genus Cyrtina C.  Davidson  septosa  Phillips  10, 11, 12, Posterior, anterior and lateral views. Genus Elytha E.  Fredricks  flmbriatus  Conrad  13, 14, 15, Ventral, dorsal and lateral views. Genus Martinopels Vaagen "M"  laevls Hall 16, 17, Posterior and dorsal views of an interior cast*  Genus Meristella Hall M.  bella Hall 18, Interior of pedicle valve showing teeth deeply excavated muscular area and the testateous thichening which f i l l s the pedicle cavity except along the median line.  M.  laevis Hall Single plate showing sub-triangular medium cavity and supporting septum x 3  M.  walcotti  Hall  PLATE  VII.  Superfamily Terebratulacae. Genus Cranaena C.  Hall and Clarke  Bchuchertl  Cloud  1, 2, 5, 4, Dorsal, ventral, lateral and anterior views of holotype. Genus Cryptonella Hall C. planirostra  Hall  5, 6, Lateral and dorsal views of a solicied shell. C.  reimsnni  Cloud  7, 8, Ventral and dorsal view of holotype. C.  exJrnia Hall 9, Dorsal view x 3.  Genus Renselandia R.  johanni  Hall Hall • *  10, 11, 12, 13* Ventral, dorsal, posterior and lateral views of a typical specimen* Genus Stringocephalus S.  DeFrance  burtina DeFrance 14, 15, Dorsal and posterior views of a medium-sized specimen.  P L A T E  SUPERFAMILY  TEREBRATELLACEA  VII  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0053561/manifest

Comment

Related Items