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AMERICAN PALEONTOLOGY
(Founded 1895)
Vol. 54
No. 240
A PELECYPOD FAUNA FROM THE GAPTANK FORMATION (PENNSYLVANIAN) WEST TEXAS
By
SAMUEL O. Birp
1968
Paleontological Research Institution Ithaca, New York 14850, U.S.A.
PALEONTOLOGICAL RESEARCH INSTITUTION
1967 - 1968 PRESIDENT i oe tads seslc ses e segs saad eaee ee do RRR Peta ae geen eee g tia KENNETH E. CASTER WICESPRESIDE NIT) sccesasieca osst eae ate eee eee ese RMON ee means WILLIAM B. HERoY SECRETARY="DREASURER: 5, d:ccssssvacesscecccsseuecscssl cesedceut oksactsectoestvcoccueccevets REBECCA S. HARRIS DIRE CTOR F clecesiccecc cals Soke coos ca gua cacceemeeerew sts eee tet eee EROS KATHERINE V. W. PALMER COUNSEL cccbsiccdeccsecescsesasesocccducsaaseecscegestcastasnecastetesccteestcosssoresiest cutcecesveeze ARMAND L. ADAMS IREPRESEN DATIVE we ACACANS i © OLIN CII pee eee eee ce KENNETH E. CASTER
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KENNETH E. CASTER (1966-1972) KATHERINE V. W. PALMER (Life) DonaLp W. FISHER (1967-1973) WILLIAM B. HEROY (1962-1968) REBECCA S. Harris (Life) AXEL A. Otsson (Life) DANIEL B. Sass (1965-1971) Hans G. KuGLer (1963-1969)
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AMERICAN PALE ON LOROGY
(Founded 1895)
Vol. 54
No. 240
A PELECYPOD FAUNA FROM THE GAPTANK FORMATION (PENNSYLVANIAN) WEST TEXAS
By
SAMUEL O. Birp Mary Washington College
April 24, 1968
Paleontological Research Institution Ithaca, New York 14850, U.S.A.
Library of Congress Catalog Card Number: GS 68-132
Mus. COMP. ZOOL- LIBRARY
MAY 10 1968
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CONTENTS
Page
ANY S tive Clan eee ee ela cere aaa sae Ua eee atc esac ead vas Savon eae uM eeu aeU ea eet Nee nace te eaee ances atch 111 TET O CUT CEO TUa ns eee ete arte et Actor Sooty RG nae Pe ee IR Te ie ean eaaten see aery auth: 111 BN CKO WEG IME MES eres ese se coe ccatee cee e ae eee nea MLD ga ae gee a en eat ge cnet nd aaeaWl eee cent Ch EGS 111 PT yy LOU See VO Thera oe reese ere cee ae ONSEN woh ote toMetnar ese seart Tada anerete ta osete 112 Strationaphy ‘and ehistoricall Geology cee ee ccsee cesses ee cee centres erecta eee eeee 112 Bre destemecolllectia mse ces ye seer ree eee MeN UR Cr Ue ein econ nun pease de Bea 114 Stratignaphicwacenotwh ee temircrscce ecctescee ectiet eae eee ee ee cern eee eee 115 Faunal list from Bed ten, Gaptank Formation ..0........0...:ccecceesseeeseeeeeeeeeeeeeeeeeeseeees 115 Pal EOE COLO Gays rer ee ee ee ae eee ra ee Ua aieatra ATE Aenea Mey genase the eee 117 HIS TS CLUS S10 TV ios eee eR Sg eA RE Ce Be Oat EBLE a a Deir ailal enn Sealant? 122 Brief glossary and abbreviations of shell morphology................:cccscceceeeeeees 123 Systematicwmp ale omtol o Sayin eecees scarce oes eee ces oe se cae des eee eeu pa set vealed eae ta eM cae ee 125 Ey cdrrn' Orv din Gd aie saree ere ie secre etc aes ae arian aR shed ogee eae nclere attest 125 Wola dormyda che si tweese on b ser senate rs en endl Sorc one ene NN ec AIL en Wa N ae 131 DENS NEM AA OK UW eN seca ase ee carat ey sa Pa a Nt ao tS Pea Be 133 Niu Gulimidiae geese ee eee ene SP sO ea Ue COU RUN esos ET I ED, 136 Grarmrmatod Onn tr diate caer ese ee ee le acer aera eaten te ee Lear oo 137 Gonocarry divalent tee eee eee eee Be gtanuh SPA) staged Melia hy Sin LAUR Dialer 143 TACO Tel ale pees ata ee a ene te eas eA Slate a rere AR OL SUR Senay nin CEM oe 144 Bamilyaiin quire nd alge less it tele hey Be eye Ne eet as, SA 146 IMAiy, till dive tosses ter et Ret Oi lee Naty cole, dR sas ie aus co WR Ue cl Ue ok 146 Mio diommor pir cia ers emote crac ce cena te ce acta Pee ah cca ceu tees ees ee eats a ence ee es 148 PENNY CCA) (Oy OX KOLO wa LE ae oe ee A Sr rear Sg eye vee yay aay ee ee ea 150 Family Inquirenda 22.00.0200... UE aes 1a a Neuis: t eeOSOS 161 TN BSC YO oY) oN ea a A ee a pr Oe ee 162 DANS tary Gl ale mest ree ae tae rn ene SUNN re Meer mee cane de rea ae yee rcAste as celUn co ae NONONLED 163 IBDN graryeaipy Tay pias co ene es NN asada eae othe Sle Dee td peeea ta ey ound ge eS ee aR 167 YeNT ON OY SH OV Ube, eek yeetacea par eS eRON a Sa aaa aS ee Sat Uo ny Noe Cae re eu 173 A Teit espe ester este eee ce call HORS alo Duca Seen at a ee A gtieenalled Rann oer BON 177
TABLES 1. Statistical comparisons of Astartella spp. for the regression of HB on Lt 165
Appendix: Tables of raw measurement data.
PUB Toy Mes) Ye a UC A ee ap ha ae Re ad ne ea 173
A Reet of edie Bd (ca a OT ee RR ON RD ee 174
SUPE eS ahi Cie See ae RR PSN NN SAD A ae AS eS a 174
Alva bl ean Vater nereesine ee hikae MUIM asa, Jie tie ete a ane edible teenie Nenana MEE 175
BT cally pes Wl pierseske nee ee geod al eS Rect Ue Eaten (Fa IE Nt Mae esa ce a etl ce Gala PE 175
EY Beet) oh LER GNVE (Beas aS aca Fe ee eT ee ee cv 176 TEXT-FIGURE
1. Sketches to illustrate measurements symbols ......002 202 eee eee 124
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A PELECYPOD FAUNA FROM THE GAPTANK FORMATION (PENNSYLVANIAN), WEST TEXAS
S. O. Bird ABSTRACT
The Gaptank Formation crops out in the vicinity of the North American standard Lower Permian in the Marathon Basin of Texas. The formation con- tains a rich, largely unstudied invertebrate fauna. The richest fossiliferous zone of the Gaptank Formation is Bed ten for which a Missourian age is indicated.
The Pelecypoda fauna from Bed ten is diverse and inciudes nine new species. Some of these species are so unique that they do not compare well to any known species. For this reason and because internal characters could not be determined, open nomenclature is used in appropriate places. The Bed ten faunal assemblage seems to belong to what Johnson (1962) termed the Chonetina association, a normal marine assemblage. Further, the association of pelecypod and gastropod genera with an abundant calcareous brachiopod assemblage would seem to indicate a deep water environment; perhaps deeper than other described North American Pennsylvanian faunas. It is suggested that depth of water accounts for the uncommon diversity of the Bed ten pelecypods. Be- cause species of the various systematic groups are normal in size and orna- mentation and because many species are common Pennsylvanian forms, an isolated normal or restricted abnormal environment does not explain the unique morphological types and unique associations found in Bed ten.
INTRODUCTION The geology of the Marathon Basin in Brewster and Pecos Counties of southwestern Texas is famous, yet little has been done with the rich Pennsylvanian fauna of the Gaptank Formation. Bed ten of the Gaptank Formation contains a rich pelecypod fauna in- cluding nine new species and a new unnamed genus. The purpose of this paper is to describe and illustrate the Pelecypoda from Bed ten. In addition, the results of a brief study of the paleoecology of Bed ten and of a quantitative study of some population samples of
Astartella spp. are included in the work.
ACKNOWLEDGMENTS
The writer wishes to express his gratitude to the following people for lending him specimens and for aiding him with valuable suggestions: G. A. Cooper, U.S. National Museum; J. M. Weller, University of Chicago; H. R. Wanless, University of Illinois; Rich- ard Leary, Illinois State Museum; Mrs. Lois S. Kent, Illinois Geo- logical Survey; L. M. Cline and L. R. Laudon, University of Wis- consin; T. J. M. Schopf and A. La Rocque, Ohio State University; P. T. Flawn and Peter Rodda, University of Texas; and H. G. Richards, Philadelphia Academy of Natural Sciences.
Special thanks are due Roger L. Batten of the American Museum of Natural History who suggested the study, helped with photographic techniques and quantitative studies, read the manu- script, and aided with his support, criticism, and advice.
112 BULLETIN 240
Dr. Herbert Howe, Professor of Geology, Purdue University, lent much help with the photography.
The writer is also indebted to Ellis L. Yochelson and John Pojeta, Jr. of the U.S. Geological Survey who read the entire manu- script and offered many valuable suggestions. Not withstanding the abundant help the writer has had, he alone is solely responsible for omissions and errors in the work.
Finally, this opportunity is taken to thank the Wisconsin Alumni Research Foundation for its financial aid to the study. Thanks are due Mary Washington College for defraying the cost of the engraving of the illustrations.
PREVIOUS WORK
The Gaptank Formation was named by J. A. Udden (1917, p. 38) from a cattle tank located in Stockton Gap, Pecos County, 25 miles north of Marathon, Texas. J. W. Beede identified some of the fauna and included a list of fossils in Udden’s paper. Other workers have discussed the Gaptank Formation in several publica- tions, the most complete being that of P. B. King (1930). This is a detailed report of the stratigraphy of the Gaptank Formation which includes a faunal list prepared by R. E. King. More recently Bostwick (1962) and Ross (1965) studied the stratigraphy and fusulines of the Gaptank Formation.
STRATIGRAPHICAL AND HISTORICAL GEOLOGY
The Gaptank Formation crops out at three major localities in the Marathon Basin; at the type locality on the Marathon-Fort Stockton highway 25 miles northeast of Marathon; at the Dugout Creek area eight miles west of Marathon; and at Black Peak, locat- ed on the north side of Doubtful Canyon (southwest of the Dugout Creek area) in the Del Norte Mountains.
At its type locality, the Gaptank Formation is folded into a broad anticline. The lower one-half of the formation may be ob- served on the southeast flank of the anticline. Here the formation consists of a series of conglomerates, sandstones, and shales. The upper part of the Gaptank Formation crops out on the northwest flank of the anticline. Five dense limestones separated by sand- stones constitute this portion of the formation. The lower part of
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 113
the Gaptank has been assigned to the Desmoinesian-Virgilian Series; the upper beds to the Virgilian Series (Moore, et al., 1944) . The lithologic break from coarse and fine clastics to carbonates and clastics is not accompanied by an unconformity. This change in rock type occurs within the Virgilian beds. About 200 feet below this change in lithology is Bed ten which is richly fossiliferous.
Exposures of the upper part of the Gaptank may be followed from the type locality to the southwest for six or seven miles. ‘These exposures are covered by wash and are somewhat scattered in dis- tribution.
At the Dugout Creek area, west of Marathon, a window in an overthrust sheet exposes the autochthonous Gaptank Formation. Outcrops of the formation are spotty and the structure is complex. Indeed, it has been difficult to determine how much of the Gaptank Formation is represented in this area. ‘The Black Peak locality to the southwest seems to be structurally related to the Dugout Creek area and here too stratigraphic relations are difficult to interpret (King, 1930, p. 46).
The sediments of the Gaptank Formation were deposited in a geosynclinal trough. The extent of this trough was apparently altered by positive elements which were periodically raised above the marine waters. Evidence of cannibalism is found in the five conglomerates in the lower one-half of the formation. According to King (1930, pp. 43-44), the conglomerates thin to the north and contain fragments of the underlying Dimple Limestone (Mor- rowan), Marvillas Chert (probably Ordovician) , and the Caballos Novaculite (probably Devonian). The angularity of pebbles and boulders from these formations seems to indicate short transpor- tation and rapid burial, The environment during deposition of most of the Gaptank Formation either was not well suited for the erowth of organisms or was not conducive to their preservation.
Orogenic uplift began in the area near the beginning of Gap- tank time, and moving from south to north through time, pro- duced geanticlines and associated troughs. The full force of these movements was exerted near the end of Gaptank time. During this orogeny, beginning in Desmoinesian time and continuing into mid- dle Virgilian time, the sediments at the type locality were folded into the broad anticline seen today. ‘The uplift that produced the
114 BULLETIN 240
thrusting in the Dugout Creek area has been dated as post-Cre- taceous (King, 1930, pp. 43-44) .
Under these rigorous conditions one would not expect to find an environment suitable for marine life. Indeed, the 1800 foot section of the Gaptank Formation at the type locality, contains only the following noteworthy faunas: (1) Chaetetes Limestone, which marks the base of the Gaptank Formation (pre-orogeny) ; (2) Bed 6, from which King reported a molluscan fauna; (3) Bed 10, the zone primarily studied here; and (4) Beds 13 and 21 from which have been reported Triticites mooreit Dunbar and Condra (1932) and Triticites cullomensis Dunbar and Condra (1932), re- spectively.
BED TEN COLLECTIONS
Bed ten consists of about 165 feet of green shale with inter- bedded argillaceous limestone units. The limestone units are 25 feet, 65 feet, and 85 feet above the base of Bed ten at a locality about two miles south and east from Gaptank. These units are two to three feet thick and are abundantly fossiliferous.
The bulk of specimens studied from Bed ten of the Gaptank Formation were collected near the type locality at Gaptank. The U.S. National Museum collections are: (1) locality 700 —2 miles S. 17° E. of Gaptank, 14% miles E. of a point on the Fort Stockton road 2 miles S. of Gaptank, about 234% miles NE of Marathon, Texas; (2) locality 700a—same as locality 700 but % mile E. in a small canyon. These collections were made by Dr. G. A. Cooper, 1940 and Drs. Cooper atid N. D. Newell, 1941. The writer made further collections in the close vicinity of localities 700 and 700a during the summer of 1956. For the most part, the specimens were collected on the shaly slopes of two arroyos below the lime- stone units of Bed ten from which the specimens had been weathered and transported.
Other zones of the Gaptank Formation are sparsely fossiliferous or characterized by only a few species. An extensive, more general collection from the Gaptank Formation is deposited at the Bureau of Economic Geology, University of ‘Texas.
The writer’s personal collections of pelecypods from Bed ten have been deposited at the U.S. National Museum.
Or
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 1]
STRATIGRAPHIC AGE OF BED TEN
Few species from Bed ten of the Gaptank Formation are use- ful as zone fossils. Those present that are regarded by Moore, e¢ al. (1944), as Pennsylvanian Series indicators are: Missouri Series — Enteletes spp., not older than Missourian; Enteletes hemiplicatus; Hystriculina splendens (also Desmoinesian) ; Streblopteria (Streblo- chondria) sculptilus; and Virgil Series — Kozlowskia wabashensis. Triticites irregularis, a Missourian Series indicator, is abundant in Bed ten. Hence the Bed ten fauna suggests a Missourian age.
Comparison of the Bed ten fauna with faunas of North Central Texas as identified by Plummer and Moore (1921) indicates the following number of species in common: Bendian Series 3; Des- moinesian (Strawn) Series 9; Missourian (Canyon) Series 12; and Virgilian (Cisco) Series 12. In some cases the same species is found in more than one series. On the basis of this comparison alone, Bed ten would correlate as well with the Cisco Series as with the Canyon. However as noted above, on the basis of the few guide fossils, the age of Bed ten is Missourian. The same conclusion was reached by Ross (1965) for beds equivalent to Bed ten (Ross’s beds A, B, and C) on the basis of the fusulines.
FAUNAL LIST FROM BED TEN, GAPTANK FORMATION
Fauna Abundance Group No.* PROTOZOA
Triticites irregularis Schellwien and Staff, 1912 CC PORIFERA
Wewokella solida Girty, 1911 A CNIDARIA
Hadrophyllum sp. RR
Lophophyllum profundum (Milne-Edwards and
Haime), 1851 C ]2
BRYOZOA
Rhombopora sp. C 5 ECHINODERMATA
Archeocidaris sp. RR
Crinoid Stems A BRACHIOPODA
Enteletes hemiplicatus plattsburgensis Newell, 1931 C
Derbya bennetti Hall and Clark, 1892 R ]
Derbya crassa (Meek and Hayden), 1859 C |
Rhychopora illinoisensis (Worthen), 1884 CC
Antiquatonia portlockiana
(Norwood and Pratten), 1854 R I Reticulatia huecoensis (R. E. King), 1951 R |
* Group numbers are from Johnson (1962)
116 BULLETIN 240
Fauna Abundance Group No.*
Aystriculina wabashensis
(Norwood and Pratten) , 1885 C Kozlowskia splendens (Norwood and Pratten), 1885 C 1 Neospirifer cameratus (Morten), 1836 R 1 Neospirifer triplicatus (Hall), 1852 R 1 Condrathyris perplexa (McChesney), 1859 CC 7 Cleiothyridina orbicularis (McChesney), 1859 R Composita subtilita (Hall), 1852 CC Composita trilobita Dunbar and Condra, 1932 C Composita elongata Dunbar and Condra, 1932 C Hustedia sp. RR 1 Punctospirifer kentuckensis (Shumard), 1852 C 1
MOLLUSCA - GASTROPODA
Warthia kingi Moore, 1941 CC Straparolus (Amphiscapha) reedsi (Knight), 1934 A 16 Mourlonia sp. C Glabrocingulum (Ananias) sp. C Worthenia tabulata (Conrad), 1835 C Gosseletina sp. Cc 7 Glyptotomaria (Glyptotomaria) apiarium Knight, 1945 RR Platyceras (Orthonychia) parvum (Swallow), 1858 A Anomphalus sp. C Trachydomia nodosa (Meek and Worthen) , 1860 AA Stegocoelia sp. R Pseudozygopleura sp. C Orthonema_ sp. C Ianthinopsis typicus (Meek and Worthen), 1860 C Ianthinopsis paludinaeformis (Hall) , 1858 C 2 MOLLUSCA - CEPHALOPODA Goniatites sp. RR MOLLUSCA - PELECYPODA “Edmondia” sp. R “Edmondia” ct. “E.” subtruncata Meek, 1872 AA Wilkingia terminale (Hall), 1852 RR 14 Pleurophorella costata (Meek and Worthen), 1869 RR Nuculopsis girtyt Schenck, 1934 RR @ Grammatodon erectumbona Bird, n. sp. RR Grammatodon hexacostata Bird, n. sp. RR 15 Grammatodon kansasensis (Sayre), 1930 RR Grammatodon carbonaria (Cox) , 1857 C Conocardium parrashi Worthen, 1890 C Pteria longa (Geinitz), 1866 RR “Promytilus”’ postumbonus Bird, n. sp. RR Goniophora gnoma Bird, n. sp. RR Acanthopecten carboniferus (Stevens), 1858 R Annuliconcha interlineata (Meek and Worthen), 1860 C Clavicosta cf. C. echinata Newell, 1937 RR Streblopteria (Streblopteria) sp. RR
Streblopteria (Streblopteria) obliqua Bird, n. sp. RR
TEXAS PENNSYLVANIAN PELECYPODS: BIRD ly
Fauna Abundance Group No.* Streblopteria (Streblochondria) aff. S. (S.) sculptilus (Miller), 1891 RR 18 Streblopteria (Streblochondria) fila Bird, n. sp. RR Streblopteria (Streblochondria) tenuilineata (Meek and Worthen), 1860 RR Streblopteria (Streblochondria) semicosta Bird, n. sp. RR Streblopteria (Obliquipecten) sp. RR Cypricardinia questa Bird, n. sp. RR “Stutchburia” corrucostata Bird, n. sp. C Astartella varica McChesney, 1859 CC ABBREVIATIONS RR—very rare R—rare CC—very common C—common AA—very abundant A—abundant
The abundance data refer only to general impressions of relative abundance. Actual quantification of data was not done.
PALEOECOLOGY
The paleoecological findings presented here are based on studies of brachiopods, gastropods, and pelecypods. General eco- logical statements concerning taxa within these groups are present- ed below. Outer neritic as used here refers to marine zones with relatively minor fluctuations in physical factors of environment; perhaps depths of 150 meters and more. Near shore means the zone where waters are somewhat agitated and subject to wide environ- mental fluctuations.
The information presented in this section is based on studies of Mid-Missourian faunas and faunal lists from a variety of lith- ologies. These studies and comparisons with the results of studies by Johnson (1962) and Mudge and Yochelson (1962) suggest that the Bed ten faunule indicates outer neritic conditions. The Bed ten assemblage compares well to what Johnson terms the Chonetina association.
In a quantitative study of 63 Middle and lower Upper Penn- sylvanian species from the area of Fulton County, Illinois, Johnson (1962) delimited 19 groups which he combined into three types of associaticns. A brief description of these associations follows: Chonetina association — consisting largely of articulate brachiopods and apparently representing a neritic assemblage living on a rela- tively firm substrate; Orbiculoidea association — dark shale as- semblage thought to represent near-shore zones and soft substrate
118 BULLETIN 240
conditions; Gastropod association — bonded to both of the other associations, conditions intermediate to those indicated in the pre- ceding associations.
Unfortunately, fusulines were not a part of the faunas studied by Johnson. Fusulines are abundant in Bed ten, but because the megafossils were mainly collected after they had weathered out of the matrix, the association of the larger invertebrates and the fusu- lines is not established for Bed ten. Mudge and Yochelson (1962) recognized 13 groups, including four with fusulines, from their study of Upper Pennsylvanian and Lower Permian rocks of Kansas. Group 4 (which included fusulines) , groups 5 and 6, and group 7 of Mudge and Yochelson (1962, p. 109) appear to coincide respec- tively with Johnson’s Chonetina association, Orbiculoidea associa- tion, and gastropod association.
Ignoring the fusulines, the fauna of Bed ten appears to be a Chonetina association though no species of Chonetina are present in Bed ten. Johnson’s Groups I and V comprise the Chonetina association; Group I contains 13 species and Group V contains four species. ‘Ten species from Bed ten may be assigned to Johnson's Group I and one may be assigned to his Group V. Of the ten Groups bonded to the Chonetina association in the original study, four Groups, represented by five species, are present in Bed ten. Of the nine groups present in Bed ten!, five are bonded to the Chonetina association and two more belong to the association proper. The other two Groups present in Bed ten are Groups 2 and 15. Group 2, represented by two species in Bed ten, belongs to the gastropod association proper and Group 15, represented by one species in Bed ten, bonds the gastropod and Orbiculoidea as- sociations. (The three Bed ten species referred to these last two Groups may not be the same species as those included in these Groups in the original study, however.) The gastropod associa- tion has species in common with the Chonetina association and the two associations are not mutually exclusive. The Orbiculoidea association, which Johnson stated to be distinct in time or space from the Chonetina association, is not represented by a single
‘See Faunal List from Bed Ten for distribution of species within the various Groups.
‘TEXAS PENNSYLVANIAN PELECYPODs: BIRD 119
species in Bed ten of the Gaptank formation though, as noted above, one species bonds at once to the Orbiculoidea and to the gastropod associations. Hence from these qualitative comparisons with Johnson’s study, the Bed ten fauna, in so far as comparisons are possible, appears to be a Chonetina association.
Below, three systematic groups from Bed ten of the Gaptank Formation are analyzed individually.
Brachiopoda. — This group is well represented in Bed ten of the Gaptank Formation. Species of Composita are by far the most abundant elements of the Bed ten macrofauna. Productid and spiriferid types are also common. The productid assemblage is rep- resented by species of the genera Reticulata, Kozlowskia, and Hystriculina; the spiriferids by species of Neospirifer and Condra- thyris. Reticulata, Kozlowskia, Hystriculina, and Neospirifer seem to be found in both near-shore and outer neritic assemblages while Condrathyris seems to have preferred only normal marine conditions. Crurithyris, the common relatively near-shore Penn- sylvanian spiriferid, as well as the better known near-shore dwell- ers, Lingula and Orbiculoidea, are absent. Derbya and the less widely distributed genera Enteletes and Rhynchopora are common in Bed ten.
Brachiopoda in Bed ten have several species in common with the faunas studied by Johnson (1962). Of those species or closely related species from Bed ten that can be compared to those of Johnson’s study, 10 out of a possible 11 total comparisons (be- longing to 7 genera) belong to Johnson’s Group I, a limestone assemblage. ‘Ten species of 10 genera comprise the articulate brachiopod group of his Group I. His assemblage in Group I in- cludes 10 of the 21 species of articulate brachiopods studied by him. This, together with the finding of the nearly complete match out of the possible comparisons of the Bed ten articulate brachio- pods, indicates that articulate brachiopods form tightly knit com- munities in Pennsylvanian limestone faunules, and that the oc- currence of members of Group I can be predicted if a few other members of the Group are known.
Gastropoda. — ‘The pleurotomariids are abundant in Bed ten. The main components of this superfamily in Bed ten are species of Worthenia, Glabrocingulum, Mourlonia, and Gosseletina. Species
120 BULLETIN 240
of Worthenia seem to tolerate a variety of environments and are found in both near-shore and outer neritic assemblages. Pleuro- tomariaceans that seem to thrive in near-shore conditions are Phanerotrema and Trepospira, neither of which are found in Bed ten. Species of Mourlonia and Gosseletina, on the other hand, ap- pear to prefer outer neritic conditions.
The bellerophontids, represented by a single genus, Warthia, in Bed ten, seem generally to indicate near-shore conditions. This statement is supported by their distribution and chemical environ- ment (high manganese and high iron content of sediments) in which they have been found (Parker, 1957, p. 116). Warthia, a common genus in Bed ten, seems to tolerate wider ranges of eco- logical conditions than most genera of this group. It is found with the apparent near-shore indicators, Knightites (Retispira), Euphe- mites, Pharkidonotus, and Bellerophon as well as with outer neritic faunas. Moore (1941, p. 124) reported Bellerophon, Euphemites, and Warthia from the oolitic part of the Ozawkie cyclothem (cen- tral Kansas) which appears to be a near-shore deposit.
Species of Platyceras are believed to be coprophagous on crin- oids (Bowsher, 1956, p. 261). This genus is abundant in Bed ten as are remains of crinoids. Trachydomia, also abundant in Bed ten, seems to live in profusion only in outer neritic waters. Stra- parolus, on the other hand, is apparently found in both near-shore and deeper marine assemblages (Mudge and Yochelson, 1962, p. 105) .
Pelecypoda. — Burrowing pelecypods are nearly absent in Bed ten of the Gaptank Formation. One specimen each of Wilkingia, Nuculopsis, and Pleurophorella were collected from Bed ten. The fauna of Bed ten comes from thin limestone units — most burrow- ing pelecypods occur in shales, sandy shales, or sandstones. Hence the substrate of Bed ten may not have been suitable for the bur- rowing forms.
Species that may have burrowed to shallow depths or else were vagrant epifauna belong to the genera Cypricardinia, Stutchburia, Edmondia, and Astartella. A pallial sinus is not present in these genera, hence none burrowed deeply, if at all. The last two gen- era rank, respectively, first and second in number of specimens per pelecypod genus. Both of these genera and Cypricardinia appear
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 121
to occupy widely diverse ecological zones. Species of Stutchburia have been so infrequently recognized that an assessment of their niche is not now possible.
Those forms that spend at least part of their existence attached by byssal threads represent the bulk of the Bed ten pelecypods. The Bed ten genera of this group are: the pectinoids Annuliconcha, Acanthopecten, Clavicosta, and Streblopteria (three subgenera pres- ent); Grammatodon (=Parallelodon) ; and “Promytilus.”
The Pectinacea is represented by more genera and _ species than any other pelecypod group in Bed ten, but no species of the group is common. The pectinaceans have a varied mode of exis- tence: living attached by a byssus (commonly to seaweed), lying on the sea floor, and swimming freely about. Roger (1939) noted that the number of littoral species of pectinids is small, and that this group is more common in the 30 to 72 meter zone in modern seas. He further noted that they are also more common from this zone to the edge of the continental shelf than elsewhere and that pectinid pelecypods found from 500 meters down are of small size and are not common. The diverse assemblage of pectinoids in Bed ten, represented by more genera and species at one stratigraphic interval than, to the writer’s knowledge, occur elsewhere, would then suggest an environment of fairly deep water. As is usually the case, probably owing to the lack of dentition in the pectinaceans, no specimen was found in the bivalve state. The valves are prob- ably separated by scavengers or the waves of storms which penetrate to deep water.
Four species of Grammatodon were identified from Bed ten. The most common species is G. carbonaria (Cox), most specimens of which are single valved and some of which are in a more clastic matrix than the typical Bed ten specimen. The specimens of G. carbonaria may have been transported from higher energy zones. In general, species of Grammatodon occur in shales, shaly lime- stones, and limestones covering a wide range of ecological condi- tions.
Only one specimen of the superfamily Mytilacea, usually a common element in marine Late Paleozoic faunules, was found in Bed ten. Present day mytilaceans thrive in the littoral and shallow neritic zones, and though present in deeper water, are much
122 BULLETIN 240
less common there. The Myalinidae probably also preferred a habitat near shore, but seem to have done better if the waters were also quiet (Newell, 1942, pp. 16-19). The extreme paucity of this common group of pelecypods in Bed ten may indicate that the water was too deep for them.
DISCUSSION
Bed ten of the Gaptank Formation has a diverse assemblage of pelecypods. The Bed ten fauna also contains a large group of articulate brachiopods. Normally, Pennsylvanian faunas rich in articulate brachiopods are sparse, both in number of species and in total number of pelecypods (Mudge and Yochelson, 1962, p. 104). This mutual lack of association of articulate brachiopods and pelecypods in the Pennsylvanian has also been noted by John- son (1962, Table 5, p. 42) and others. Yet it appears that the Bed ten fauna represents a biocoenose which lived below wave base for specimens show little abrasion, fragmentation, or sorting by size. Further, the pelecypods, with the exception of the pecti- noids, are almost all in the bivalve condition.
The diversity of the pelecypod assemblage, particularly the di- versity of the pectinoids, coupled with the absence of mytilaceans, the association of pelecypods with the large group of articulate brachiopods, the lack of evidence of wave energy (including the lithology) in Bed ten of the Gaptank Formation all indicate an outer shelf environment.
Beyond the evidence discussed above, an environment of normal marine, deep or moderately deep water is attested to by the great abundance of the fusuline Triticites irregularis Schellwien and Staff. Dunbar (1957, pp. 753-4) noted that the fusulines indi- cate well aerated, normal marine waters, and that they seem gen- erally to have preferred zones free from wave agitation. Further evidence of well aerated water is the profusion of crinoidal re- mains in Bed ten. (Because Dunbar, op. cit., stated that fusulines rarely occur with crinoids and mollusks, it might be that the fusu- lines represent a different cycle of deposition than the rest of the fauna discussed above) .
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 123
BRIEF GLOSSARY AND ABBREVIATIONS OF SHELL MORPHOLOGY
Auricles, ears, wings — extensions along the dorsal margin of some valves, par- ticularly well developed in pteriids, limiids, and pectinoids.
Byssal notch — excavation in the shell for passage of byssal threads which serve to attach the organism io the substrate. In pectinoids the notch is best de- veloped on the anterior auricle of the lowermost (right) valve. In arcoids the notch is on the ventral margin of the valves and is equally developed on the two valves. In mytiloids the notch is usually in the anteroventral mar- gin of both valves. (See sinus and sulcus below.)
Costae, costellae, ribs — radial ornament of variable weight.
Fila, lamellae, ridges — concentric ornament of variable weight, coarser and more regular than growth lines.
Gape — lack of complete contact along line of commissure.
Interspaces — areas between concentric or radial ornament.
Obliquity — A. Beaks—untwisted, 7.e., meeting the dorsal margin at right angles are orthogyre; anteriorly directed beaks are prosogyre; posteriorly directed beaks are opisthogyre.
B. Shell-umbonal ridge vertical between dorsal and ventral margin is termed acline; umbonal ridge concave posteriorly is prosocline; and um- bonal ridge concave anteriorly is opisthocline.
Shell body — shell exclusive of auricles.
Sinus —a shallow groove in the left anterior auricle of pectinoids and in the antero-ventral portion of the shell of mytiloids and some arcoids.
Sulcus — depression between anterior auricle and shell body in pectinoids; de- pression extending dorsally from ventral margin in arcoids and mytiloids. In both cases the sulcus is formed by the migration of the byssal notch with shell growth and commonly can be seen in the growth lines or coarser con- centric ornament.
Umbones — beaks and adjacent elevated portion of valve dorsal and lateral ex- terior, extending variable distances ventrally.
Umbonal folds — shoulders between shell body and auricles.
Umbonal midline — trace of the center of the umbones.
ABBREVIATIONS
BV — bivalved specimen.
LV — left valve.
RV —right valve.
C — convexity, the maximum depth of valve (s) measured perpendicularly to plane of commissure.
DAMB — distance from anterior margin OE hinge line to tip of beak.
DPMBE —distance from posterior margin of hinge line to tip of beak. Along with DAMB measures the inclination and position of beaks.
DUR — maximum distance between umbonal ridges, usually at posterior margin of valves.
Ht — height of vaive, maximum dorsal-ventral dimension.
Lt—length of valve, the maximum anterior-posterior dimension measured parallel to hinge line.
LH — length of hinge line.
HB — height of beak, measured vertically from tip of beak to hinge line.
HAA — height of anterior auricle, maximum vertical dimension.
LAA — length of anterior auricle, maximum horizontal dimension.
HPA — height of posterior auricle.
LPA — length of posterior auricle.
124 BULLETIN 240
Cc Ht Wy OPMB —
= TZ DAMB Lt a
HS
MLS
trace of umbonal mid-line
portion posterior to umbonal mid- line
portion anterior to umbonal mid-line
Text-figure 1. Sketches to illustrate measurements symbols.
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 12
Or
HIL — height of internal ligamental area or chondrophore, maximum vertical dimension.
LIL — length of internal ligamental area or chondrophore, maximum horizontal dimension.
LLA — length of external ligamental area, measured parallel to hinge line, at line of maximum dimension.
WLA — width of external ligamental area, measured along slope of ligamental area at line of maximum dimension.
HS — maximum height of sulcus formed in response to migration of byssal notch.
MLS — maximum length of sulcus.
LES — length of escutcheon, measured parallel to hinge line.
WES — maximum width of escutcheon, measured perpendicular to hinge line.
LLu — maximum length of lunule, measured parallel to hinge line.
WLu — maximum width of lunule, measured perpendicular to hinge line.
OI — obliquity index, distance measured parallel to hinge line from trace of umbonal midline of early ontogenetic stages to anteroventral and_ postero- ventral margins. The index is the ratio of the anterior distance to pos- terior distance. Hence a value of one indicates an acline shell, a value of more than one indicates a prosocline shell, and a value of less than one indicates an opisthocline shell.
PC — peripheral commissure, measured by tracing the length of the line of commissure; a rough index of valve size and, with combinations, of valve shape.
(1) — measurements taken on one valve of a bivalved specimen.
SYSTEMATIC PALEONTOLOGY Class PELECYPODA
Family EDMONDIIDAE King
Discussion. — Convergence in external morphology between, at least four edentulous Upper Paleozoic genera, is so strong that confusion in identification is possible; yet each of the genera is in a separate family. These genera are Sanguinolites McCoy, 1844; Ed- mondia de Koninck, 1844; Pleurophorella Girty, 1904; and Wilk- ingia Wilson, 1959. In ornamentation and shape these taxa over- lap; ligamental areas are poorly known. Internal characters, of course, serve to resolve the difficulties, but these features can sel- dom be observed and hence are not well documented. Brief notes on distinguishing characteristics of these genera follow.
Wilson (1959, 1960) has been active in a search for under- standing of some of the edentulous genera. He confirmed the presence of internal cartilage plates in the type species of Edmondia, Isocardia unioniformis Phillips, 1836. He also determined that Hiatella sulcata Fleming, 1828 — Sanguinolaria? sulcata Phillips, 1836 has these plates, and he judged Fleming’s species to be an Edmondia. At least one other species assigned to Edmondia has
126 BULLETIN 240
these unique structures, Edmondia primaeva (Portlock) , 1843, fide Hind (1899, pl. 30, fig. 2). These structures are now used to characterize Edmondia s. s. Subgenera have not been proposed for species of Edmondia which do not possess the cartilage plates but presumably will be.
At least some species of Wilkingia gape posteriorly and Wilson has verified the presence of a pallial sinus in the type species, Venus elliptica Phillips, 1836.
Internal characteristics of both Sanguinolites and Pleurophor- ella ave virtually unknown. Hind (1900) included at least two species in his illustrations of the type species of Sanguinolites, Sanguinolaria? angustata Phillips, 1836; the holotype (pl. 40, fig. 1) is not illustrated to show the dersal margin. The species repre- sented by Hind’s plate 40, figures 3, 3a, 5 are not conspecific with the holotype as supposed by Hind. These latter specimens are similar to “Allorisma”’ costata — Pleurophorella costata (Meek and Worthen) , 1869. Hind’s figure 3a shows this specimen to have the long narrow ligamental groove of “Allorisma” costata. What the ligamental area of the type species of Sanguinolites looks like is not known. If it does not have a ligamental area of the “Allorisma” costata type, Sanguinolaria? angustata Phillips, 1836 may prove to have internal cartilage plates as did what Phillips (1836) called Sanguinolaria? sulcata and thence be likewise assigned to Edmondia.
Girty’s description of Pleurophorella did not serve to distin- guish this genus from others. The internal characters of the type species, P. papillosa Girty, 1904 are completely unknown. Girty placed Allorisma costata Meek and Worthen, 1869 into his new genus. One specimen of Meek and Worthen’s species, which is de- scribed later under Pleurophorella, shows this species to possess a chondrophore. ‘Tentatively then, Girty’s genus Pleurophorella is inferred to possess an internal ligamental area and the generic name is retained. It may turn out that the type species of Sanguinolites has external and internal ligamental areas like that of Pleurophor- ella costata, in which case this species would be assigned to San- guinolites.
Genus “EDMONDIA” de Koninck, 1844
Diagnosis. — Shell equivalve, inequilateral, not gaping, sub-
TrExaAs PENNSYLVANIAN PELECYPODs: BIRD 27)
ovate to subrectangular; beaks anterior, prosogyre; hinge edentu- lous; ligament internal?, external?, marginal?; adductors subequal; pallial line simple; valves smooth or with concentric ridges.
Ty pe species. - Edmondia unioniformis (Phillips) = Isocardia unioniformis Phillips, 1836. Subsequent designation King (1850, p. 162); Stoliczka, 1871, p. xvil.
Range. — Devonian-Permian.
Discussion. — Much confusion exists concerning the characters of this common genus. De Koninck (1844, p. 66) included in his description the statement “lunule echancree”. ‘This statement has been interpreted by various authors to mean that the genus has a lunule and by others that its valves are gaping. That neither in- terpretation is correct may be determined from the characters of the type species. The first of the two Edmondia species described by De Koninck was identified by him as Edmondia unioniformis (Phillips) , 1936. Although the species figured by De Koninck is likely congeneric with that of Phillips, the species appears to be distinct from Phillip’s species as noted by Hind (1899, p. 288). The type species was designated by King (1850, p. 162). Girty (1915, p. 105) erroneously supposed that the type species need be that species which De Koninck figured.
Wilson (1960) studied three syntypes of the type species and designated a lectotype. These specimens show that the type species has neither lunule nor gape. However, according to Wilson all three of the type specimens possess cartilage plates or ossicles. These plates, first noted by King (1850) can be best understood from illus- trations by Hind (1899, pl. 30, fig. 2) and by Wilson (1960, pl. 2, figs. 1-4). The function of these unique plates is not known: their presence may indicate that Edmondia had an internal ligament or had both internal and external ligaments or perhaps they served merely to strengthen the valves (possibly against a dorsally orient- ing predator) .
From a systematic rather than a functional viewpoint the cartilage plates have introduced deeper problems. Many species, including perhaps all American species?, previously assigned to
* Elias (1957) reported cartilage plates in a specimen of Edmondia from the Red Oak Hollow Formation of Oklahoma: he did not illustrate this specimen however.
128 BULLETIN 240
Edmondia have not been observed to have cartilage plates. Girty (1915, p. 105) noted that American shells assigned to Edmondia do not have these plates. No specimen from the Gaptank Forma- tion was seen to have such structures. Therefore, open nomencla- ture is used here to refer to what would earlier have been consid- ered to be typical species of Edmondia.
The hinge structure which Hind (1899) called a transverse lamella, but which was not mentioned by Wilson (1960), is a narrrow toothlike rumple on the posterior part of the hinge plate. A somewhat similar, elongate ridge is observed on the hinge areas of specimens of “Edmondia” subtruncata from the Gaptank Forma- tion. This ridge is above the line of commissure in these speci- mens, however.
Species of Edmondia are difficult to characterize. ‘They are generally ornamented only by irregular fila, leaving gross form as the basis for distinction. Until more species of the genus are studied quantitatively and an idea of the variation in form ob- tained, it will continue to be difficult to make correct identifica- tions and comparisons.
Edmondia is closely related to Cardiomorpha de Koninck, 1844; the characteristics of Cardiomorpha have been only poorly defined and much latitude has been permitted in the interpre- tation of the generic characters. Several genera were included in the 17 species originally assigned to Cardiomorpha by De Koninck.
The type species of Cardiomorpha, C. elongata de Koninck, 1844 designed by King (1850, p. 179), is easily distinguished from species of Edmondia by its being higher than long and by its in- curved beaks. In subsequent works, thick-shelled edentulates with strongly incurved beaks, some with distinctly longer than high valves, have been referred to Cardiomorpha.
Now the only consistent difference between Cardiomorpha and “Edmondia” is that species of Cardiomorpha have strongly in- curved beaks. Whether this characteristic alone should be given generic significance and whether other differences such as shell structure and musculature exist between species of the two genera must be answered by further study.
TEXAS PENNSYLVANIAN PELECYPODs: BIRD 129
“Edmondia” sp. Pl. 11, fig. 1
Diagnosis. — Shell large, thick subovate; anterior margin broad- ly rounded; posterior margin truncate; ventral margin subparallel to dorsal margin; umbones prominent, broad; umbonal ridge in- distinct; beaks prosogyre, anterior; ligamental area opisthodetic, wide; convexity high, maximum convexity midway between top of umbo and ventral margin; external ornament of indistinct lamellae and faint, irregular, closely spaced radial lines.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm) .
Jel Lt ¢ R.V. 45.5 63.8 18.8 R.V. 42.5 54.3 14.0
Material. — U.S. National Museum, No. 155826.
Discussion. —Three specimens of this thick-shelled form were collected from Bed ten of the Gaptank Formation. One well-pre- served specimen displays minute, irregularly spaced and developed radial striations. The other two specimens are more deeply eroded and no trace of the radial ornament is present on them. The radial striations may be produced by slight weathering of the outer ostra- cum with the resultant fine striations reflecting the radial tangen- tial prismatic structure of that shell layer. If, on the contrary, the striations are true ornament, the ribbing is restricted to the outer surface of the valves.
“Edmondia” cf. “E.” subtruncata Meek, 1872 Pia figs. 2-6
Edmondia subtruncata Meek, 1872, U.S. Geol. Sur., Nebraska, Final Rept., p. Diy ple Qatign i:
E. ovata Meek and Worthen, 1873. Geol. Sur. Illinois, vol. 5, pl. 26, fig. 13; Meek, 1874; Amer. Jour. Arts and Sci., 3d ser., vol. 7, p. 580; Girty, 1915, U.S. Geol. Sur. Bull. 544, p. 106, pl. 14, fig. 13 Diagnosis. — Shell subovate to subrectangular; hinge line nearly
straight to gently convex; anterior margin subtruncate to sharply rounded; posterior margin gently rounded to straight, meeting dorsal margin at obtuse or nearly right angle; umbonal ridge distinct, round; convexity rapidly decreasing posterior to ridge; maximum convexity on umbones near dorsal margin; beaks proso- gyre; umbones prominent, wide and inflated; valves smooth except for growth lines and irregularly spaced fila.
130 BULLETIN 240
Range. — Pennsylvanian.
Measurements. — (See Appendix) .
Material. — Hypotypes, U.S. National Museum, Nos. 155827, 155828.
Discussion. — Meek and Worthen’s Edmondia ovata was not accompanied by a description. Meek (1874, p. 580) later stated that he doubted if £. ovata was distinct from E. subtruncata. Judg- ing by the figures of the two proposed species and the amount of variation noted in Gaptank representatives tentatively referred to “E.” subtruncata, it appears that the name E. ovata is unnecessary.
Wide variation in form exists in the specimens collected from the Gaptank Formation. Some are elongate posteriorly, others are truncated posteriorly and anteriorly and others are as high as long. Elongate specimens compare well to Meek’s original figure except in ornament. In the few Gaptank specimens in which the ornament is preserved, the fila are more irregularly spaced and of more unequal weight than in Meek’s figured specimen.
Length of hinge, portion of hinge posterior to beak, and peri- pheral commissure are other variable characters. Height of beak and portion of hinge anterior to beak show relatively little varia- tion.
The marked variability of the hinge posterior to beak com- pared to the relative lack of it anterior to the beak suggests that most growth anteriorly is attained early in the life of the organism and that growth posteriorly continues for a longer period of time. This allometry is not related to development of siphons in Ed- mondia for the pallial line is simple. Hence if species of Edmondia burrowed, they did so only to shallow depths.
Specimens here assigned to “Edmondia” subtruncata are the most common members of the pelecypod fauna in Bed ten of the Gaptank formation. The vast majority of the specimens collected were in the bivalve condition, though in many, one valve is ro- tated with respect to the other. Incongruously, the ornament of only a few specimens is well preserved. Apparently the ornament, con- sisting of fine fila, was present only in the upper layer of the shell material and has been removed during diagenesis of the sediment. The notion that the fila are resorbed during later ontogenetic
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 131
stages is untenable because young forms show the same poorly pre- served ornamentation as older specimens.
Family PHOLADOMYIDAE Gray Genus WILKINGIA Wilson, 1959 (Allorisma King, 1844 and 1859)
Type species.— Venus elliptica Phillips, 1836. Original desig- nation.
Range. — Mississippian-Permian.
Discussion. — This well-known genus has been recently inves- tigated by Wilson (1959), who gave it the new name Wulkingia. King (1844) originally chose Sanguinolaria? sulcata Phillips, 1836 — Edmondia sulcata (Phillips), 1836; Wilson, 1960 as the type species of Allorisma King, 1844. In 1850 King revised the genus Allorisma and, using the name Allorisma, selected a new type species, Hiatella sulcata Fleming, 1828, thereby apparently creating a homonym. However, according to Wilson (1959, 1960), HZ. sa?- cata F.eming, 1828 — Edmondia sulcata (Fleming), 1828 — Ed- mondia sulcata (Phillips), 1836. Hence Allorisma King, 1844 is synonymous not homonymous with Allorisma King, 1850. In spite of King’s selection of an Edmondia for the type species of Allorisma, his later description of Allorisma is essentially that of Wilkingia. The reason for the similarity of descriptions is that King, (1850) based his description on Venus elliptica Phillips, 1836, the type species of Wilkingia, which he figured and erroneously identified as Hiatella sulcata Fleming.
Wilkingia terminale (Hall), 1852 Pl. 12, fig. 16
Allorisma terminale Hall, 1852, Stansbury’s Expedition to Great Salt Lake, p 413, pl. 2, fig. 4.
A. subcuneata Meek and Hayden, 1858a, Acad. Nat. Sci. Philadelphia, Proc., p. 263.
A. terminale (Hall), Girty, 1903, U.S. Geol. Sur., Prof. Paper 16, p. 437, pl. G, figs. 4-6.
Diagnosis. — Shell elongate, maximum length near ventral mar- gin; anterior margin rounded to nearly straight; posterior margin gently rounded; ventral margin gently convex, maximum depth about two-thirds way from anterior to posterior margin; umbones prominent, erect, wide; beaks orthogyre, located far anteriorly; umbonal ridge broad, rounded, gently concave dorsally; convexity
132 BULLETIN 240
high in relation to height of valves, maximum convexity just pos- terior and ventral to umbones; lunule and escutcheon large, dis- tinct; surface marked with widely spaced, prominent concentric ridges, more closely spaced ventrally, without fine lines in inter- spaces.
Range. — Pennsylvanian.
Measurements. — (Mm) ;
lal, Jot JL WLu C DAMB
IW 38.1 82.3 15.6 9.0 37.2 ai BW. 56.1 74.6 Med 9.3 28.4 10.8 TR We 54.0 OWES: 24.2 13.6 40.7 14.6 BW 56.8 12358 41.1 14.6 58.0 12.8 ADVE 43.0 84.8 26.5 8.7 50.9 19.6 AY 55.2 128.0 40.0 15.4 AAW, 29.0 50.4 20.6 5.5
* Holotype. **Labeled “‘cotypes” of Allorisma subcuneata.
Material. — Holotype, U.S. National Museum No. 15072, type collection. “Cotypes” of Allorisma subcuneata. U.S. National Mu- seum, No. 6608, type collection. Hypotype, U.S. National Museum, No. 155829.
Discussion. — ‘The external mold which is the holotype of this species can be distinguished from specimens at the U.S. National Museum labeled as “cotypes” of Wilkingia suwbcuneata by its more anteriorly located beaks, its deeper, wider lunule, and by its um- bonal ridge which is more concave upward. However, Girty’s (1903, p. 438) interpretation that the holotype is a distorted speci- men appears to be correct. Hence specimens that Meek and Hay- den called Allorisma subcuneata are now considered more typical representatives of A. terminale.
Hind (1900, p. 421) wrote that Wilkingia maxima (Portlock) , 1843 cannot be separated from W. swbcuneata. Hind had the holo- type of Portlock’s species but did not note the number or nature of the specimens of the American shells that he compared to W. maxima. The holotype of Portlock’s species is incomplete, the whole posterior portion of the shell is missing. Until more complete comparisons are made, it seems best to treat Portlock’s species as distinct from Hall’s.
TEXAS PENNSYLVANIAN PELECYPODS: BiRD 133
One specimen of W. terminale, an external mold, was collect- ed from Bed ten of the Gaptank Formation.
Family ANATINIDAE Dall Genus Pleurophorella Girty, 1904
Allorisma of authors; Sanguinolites pars of Hind, 1900; Permophorus pars of Newell, 1957.
Diagnosis*. — Shell equivalve, strongly inequilateral, gaping (2), elongate; beaks well anterior, small, prosogyre; umbones broad, flat; umbonal ridge sharp, distinct; ligament opisthodetic, set in distinct grooves; resilium set on triangular chondrophore (s) ex- tending on both sides of the beak; lunule indistinct, escutcheon prominent; adductors and pallial line unknown; ornament con- sisting of well-developed concentric lamellae or ridges and tiny papillae.
Type species.—Pleurophorella papillosa Girty, 1904. Orig- inal designation.
Range. — Pennsylvanian.
Discussion. —'The original description of this genus does not include characteristics which separate the genus from Wilkingia. The internal features of the type species are unknown. Newell (1957, p. 9) suggested that the type species may be a Permophorus Chavan, 1954. Newell’s evidence for this view is a similarity in external form between Pleurophorella papillosa and some smooth forms of Permophorus. If Newell is correct in his interpretation, a new genus will need to be erected for what is here called Plewro- phorella costata. It is also remotely possible that with further study the species will be placed in Sanguinolites as was suggested under the discussion of the Edmondiidae.
The description of the genus above is an emended one based on an excellently preserved specimen of Allorisma costata Meek and Worthen, 1869. This specimen (Plate 11, fig. 7) from the Graham Formation of North Central ‘Texas, displays a chondro- phore. Girty’s intuitive separation of this species from Allorisma is therefore sound. ‘The chondrophore has been observed only in
*Emended diagnosis based on specimen of “Allorisma” costata Meek and Worthen, 1869.
134 BULLETIN 240
the left valve; preservation has not permitted judgment as to whether the right valve also has this structure. Other internal characters of the genus remain unknown. It is not yet known if the valves gape posteriorly.
The presence of a chrondrophore in Pleurophorella costata is of great interest for, with the exception of the nuculoids, it is the earliest probable burrower possessing this type structure. Hence Pleurophorella may prove to be the progenitor of the long line of edentulous, chondrophore bearing burrowers of the Mesozoic and Cenozoic Eras. Further work on the nature of shell structure, muscu- Jature, and pallial line is needed to show this proposed relation- ship to be correct.
Pleurophorella may be separated from the closely related gen- era Wilkingia Wilson, 1959 and Sanguinolites McCoy, 1844 by its possession of the chondrophore. It also distinguishes Pleurophor- ella from the earlier genera Orthonota Conrad, 1841 and Sphenotus Hall, 1885, both of which closely resemble Pleurophorella exter- nally.
Pleurophorella costata (Meek and Worthen), 1869 Pl. 11, figs. 7-14
Allorisma costata Meek and Worthen, 1869, Acad. Nat. Sci. Philadelphia, Proc..
p- 171; Meek and Worthen, 1873, Geol. Sur. Illinois, vol. 5. p. 585, pl. 26,
fig. 15.
Sanguinolites angustatus pars (Phillips), Hind, 1900, British Carboniferous
Lamellibranchs, vol. 1, p. 366.
Pleurophorella costata (Meek and Worthen), Girty, 1904. U.S. Nat. Mus.,
Proc., vol. 27, p. 723.
Diagnosis. — Shell elongate, thin; anterior margin short, gently rounded, gradually rounded to dorsal margin; posterior margin truncate, nearly straight, proceeding linearly forward to join dor- sal margin at obtuse angle, joined to ventral margin in slightly obtuse angle; ventral margin gently arched, with a slight sulcus under umbones; umbones wide, prominent, slightly compressed, low; umbonal keel sharp, nearly straight to gently concave upward; dorsally a fainter, lower ridge occurs, becoming obsolete anteriorly; hinge edentulous; directly beneath beaks is a small triangular process (chondrophore) separated from main, external ligamen- tal area by a thin ridge running obliquely posteriorly; ligament mainly external, opisthodetic, set in long narrow, unornamented groove; lunule indistinct, escutcheon prominent; beaks small, near-
TreExAS PENNSYLVANIAN PELECYPODS: BIRD 135
ly orthogyre; ornament of concentric ridges with irregularly spaced, and irregularly raised, discontinuous lamellae; ornament dorsal to umbonal ridge slightly subdued.
Range. — Pennsylvanian.
Measurements. — (Mm).
Ht Lt HB C2) DUR LH LLA WLA LES WES LIL HIL R.V.414.0 30.0 Bae Gsleso:Ou olin (ae OOO 19:8 9 OG) al ealkOh Sole 0:9 Rave 1107-- 26:8 3.3 L.V. 10.2 16.2 BIE 9:9 22:0 10.0 Ibe Wee) Gea PRI TsVe auc6) 2641
Material. — Hypotypes, U.S. National Museum, Nos. 155830, 155831. linois Geological Survey — collections of H. C. Wanless and J. M. Weller. Meek and Worthen specimens: Probable holo- type and three paratypes; Illinois State Museum.
Discussion. — Meek and Worthen’s specimens at the Illinois State Museum do not possess labels clearly indicating a holotype (Richard Leary, written communication) . The specimens are fra- eile and as a result could not be sent to me for examination. ‘The best preserved specimen is a mature right valve which is figured in Plate 11, figure 13. According to Leary this specimen is probably the holotype of Pleurophorella costata (Meek and Worthen) , 1869 = Allorisma costata Meek and Worthen, 1869. Measurements of this specimen are close to those cited by Meek and Worthen and the specimen illustrated by them later (1873) was a right valve.
Pleurophorella costata is more elongate in relation to height than P. papillosa Girty. P. costata also has much more prominent concentric ridges than P. papillosa. Both species have one prom- inent umbonal keel and a fainter umbonal keel dorsal to this. Two specimens of what Hind (1900, pl. 30, figs. 3, 3a, 5) con- sidered to be Sanguinolites angustata (Phillips) , 1836, are close to Pleurophorella costata in form and ornamentation. The interior of these specimens is unknown. Judging from the figures, Hind’s identification of these two specimens is incorrect. The generic as- signment may also be inaccurate. ‘The single dorsal view (pl. 30, fig. 3a) shows an external ligamental area like that of Pleurophor-
*Probable holotype.
136 BULLETIN 240
ella costata; no indication of a chondrophore is observable in this view.
Pleurophorella costata has been reported from several areas of the Mid-Continent Pennsylvanian but seems never to have been abundant. Its range is here extended to the Graham Formation of North Central Texas and to the Gaptank Formation of West Texas where one specimen was found.
Family NUCULINIDAE d’Orbigny Genus NUCULOPSIS Girty, 1911
Type species. — Nucula ventricosa Hall, 1858 non Hinds, 1843 = Nuculopsis girtyi Schenck, 1934. Original designation.
Range. — Mississippian-Pennsylvanian.
Discussion. — Nuculopsis is the name given by Girty to nucu- loids with supposedly anteriorly located beaks. Species of Nucula s.§. Lamarck, 1799 have the beaks at the posterior end of the shell. Girty (1911, p. 133) regarded the long portion of the hinge as pos- terior in Nuculopsis and hence as having the more typical pelecy- pod relationship between beak position and anterior end of shell. Girty’s basis for this conclusion was his observation that what he took for a ligamental groove is on the long portion of the hinge on the type species. A pallial sinus is absent in Nuculopsis as it is also in Nucula. Schenck (1934), however, believed that specimens of the type species had an internal ligament and a chondrophore and believed, therefore, that the short side of the shell is posterior in Nuculopsis as in Nucula. Schenck’s evidence is not convincing. Elias (1957, p. 747) confirmed Schenck’s interpretation that an ex- ternal ligament was not present in the type species of Nuculopsis. That the short side of Nuculopsis is posterior has also been sug- gested by Driscoll (1964) on the basis of his study of pedal muscu- lature. Elias further noted that a chondrophore is present in Nucu- lopsis girtyt. The chondrophore, according to Elias, does not inter- rupt the dental series in Nuculopsis girtyi, whereas in Nucula spp. the dental series is interrupted by this structure. Hence the nature of the dental structure and chondrophore offer a basis of generic distinction in the group. Species of Nuculopsis are further charac- terized by having smooth inner ventral margins. Species of Nucula s. 1. also may lack ventral denticles.
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 137
The interpretation of Schenck and Elias that the posterior is the short end of the shell is used here.
Nuculopsis girtyi Schenck, 1934 Pl. 13, fig. 4
Nucula ventricosa Hall, 1858, Iowa State Geol. Sur., vol. 1, pt. 2, p. 716, pl.
29, figs. 4, 5 [non N. ventricosa Hinds, 1843].
Nuculopsis ventricosa (Hall), Girty, 1915, U.S. Geol. Sur., Bull. 544, p. 117, pl.
15, figs. 1-8.
Nuculopsis girtyit Schenck, 1934, Mus. Roy. d’Hist. Nat. Belgique, Bull., vol.
LOSING 2 20% pe 29 Splits 2 sates! Solera do? :
Nucula (Nuculopsis) girlyi (Schenck), Hoare, 1961, Desmoinesian Brachiopoda and Mollusca from Southwest Missouri, p. 101, pl. 13, figs. 7, 8.
Diagnosis. — Shell subovate; posterior margin just projecting in. back of beaks, short, rounded; anterior margin sharply rounded; ventral margin gently convex; dorsal margin gently arched; um- bones prominent, posteriorly placed, broad; umbonal ridge not distinct; surface marked with concentric lamellae of two sizes.
Range. — Pennsylvanian.
Measurements. — Hypotype, bivalved, (mm). Ht. 9.0; Lt 17.0; C720:
Material. — Hypotype, U.S. National Museum, No. 155832. Bureau of Economic Geology, University of ‘Texas Locality 185- T-4.
Discussion. — Only one specimen of this species is on hand from Bed ten of the Gaptank Formation. However, at Texas Uni- versity Locality 185-T-4, a locality north of Gaptank, in strata younger than Bed ten, the species is very abundant.
Family GRAMMATODONTIDAE Branson Genus GRAMMATODON s. 1. Meek and Hayden, 1860
Type species.— Arca inornata Meek and Hayden, 1858 (1858b) . Original designation.
Range. — Devonian-Cretaceous.
Discussion. —The taxonomy of this family remains in con- fusion though several paleontologists have treated the group, to wit, Arkell (1930), Branson (1942), and Driscoll (1961). The con- fusion arises in part from the question of systematic relationships of Mesozoic and Paleozoic representatives of the group and in part from legal aspects of names. Grammatodon Meek and Hayden, 1860 has priority with respect to Parallelodon Meek and Worthen,
138 BULLETIN 240
1866. Branson (1942) considered the two genera, each represented by distinct species, as belonging to one genus. However, Nicol (1954) considered Grammatodon to belong to the family Cucul- laeidae. Nicol’s evidence is not convincing, and he stated that his conclusions were tentative. Branson’s treatment of Paleozoic ar- coids with elongate posterior teeth, subovoid to rectangular shape, cancellate to nearly smooth shells, with or without byssal gape as belonging to one genus, Grammatodon, is followed here. No attempt is made to apply subgeneric designations. Grammatodon erectumbona Bird, n. sp. Pl. 12, figs. 12-14
Diagnosis. — Shell subrhomboid; anterior margin gently round- ed; posterior margin slightly obliquely truncate to nearly straight; ventral margin nearly straight; umbones broad, erect, not inclined; umbonal ridge prominent, sharp, distinct to postero-ventral margin; beaks slightly prosogyre; ornament of fine, sharply rounded, closely spaced radial ribs, ribs nearly equal in weight all around shell in young forms, more uneven in adults, concentric ornament of growth lines only.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm) .
Ht Et ¢ ital Holotype BAe 7.4 228 7.8 12a Paratype RAVE Wee 19.8 Paratype LAY, 9.8 16.0
Material. — Holotype, U.S. National Museum, No. 155833. Paratypes, U.S. National Museum, No. 155834, 155852.
Discussion. — This species is distinguishable from all others by its erect broad umbones; its lack or near lack of a ventral sinus and by its ornamentation. The ornament consists of sharply round- ed ribs which become less sharp posteriorly. ‘The ribs are not regu- lar in weight across the valves but do not increase in size pos- teriorly as in G. biplicata. Some of the ribs are bifid, especially on the anterior portion of the sheil—where they branch about one- halfway from beaks to ventral margin — and on the concave region of the shell posterodorsal to the umbonal ridge —where they branch about three-fourths of the way from beak to posterior mat-
gin.
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 139
The internal features could not be observed in any of the three specimens collected of this species. Two of the specimens are single valves, a left and a right, embedded in calcareous matrix; the other, the holotype, is a fine bivalved specimen.
Grammatodon hexacostata Bird, n. sp. Plas. figs 2
Diagnosis.— Shell elongate, low; anterior margin nearly straight; posterior margin obliquely truncate; ventral margin gently convex with distinct shallow groove just below umbones and becoming obsolete about two-thirds up from ventral margin, maximum depth of ventral margin near posterior extremity; um- bones low, gently inclined anteriorly; umbona! ridge distinct, broad becoming obsolete near posteroventral margin; ligamental area wide, marked with three—five faint, minute, chevron-shaped grooves; central teeth tiny, slightly convergent, lateral teeth not observed; ornament of numerous, distinct, rounded ribs of nearly equal weight all around shell, except where bifurcate and except in the ventral sulcus where there are six ribs of smaller size than ad- jacent ribs, concentric ornament of growth lines which become coarse enough dorsally and posteriorly, beginning on posterior por- tion of umbones and extending posteriorly beyond umbonal ridge, to impart a nodose aspect to ribs.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm).
Ht [Gt C LH Holotype B.V. 10.5 18.2 8.0 13.2 Paratype Rev. 10.1 13.0 geno)
Material. — Holotype, U.S. National Museum, No. 155835. Paratype, U.S. National Museum, No. 155836.
Discussion. — This species is similar to the specimens identi- fied and illustrated by Meek and Worthen (1873) as Parallelodon tenuistriata (Meek and Worthen) , 1866. Grammatodon hexacos- tata is distinct in that the ribs are equal in prominence in the an- terior and posterior portions of the shell. Further, G. hexacostata has a more pronounced ventral sinus and sulcus and the ribs of this region of the shell are six in number and are smaller than adjacent ribs. Finally, some of the ribs in G. hexacostata are ir- regularly bifid, the branching taking place at irregular distances
140 BULLETIN 240
from the ventral margin. The position of the bifid ribs is differ- erent from that in G. erectumbona. In G. hexacostata, the ribs anterior and posterior to the ventral sinus, but not posteroventral to the umbonal ridge, are bifurcate. In G. erectumbona, the ribs on the anterior portion of the shell and those above the umbonal ridge are bifid.
Two specimens, one bivalved (the holotype) and the other a fragmentary right valve, were collected from Bed ten of the Gap- tank Formation.
Grammatodon cf. G. kansasensis (Sayre), 1930 Pl. 12, fig. 15 Parallelodon kansasensis Sayre, 1930, Univ. Kansas Bull., vol. 31, p. 108, pl. 9, figs. 4-7.
Diagnosis. — Shell elongate, low; anterior margin acute, nar- row; posterior margin obliquely truncate, narrow; ventral margin nearly straight, with vague ventral sinus, subparallel to dorsal margin; umbones low, broad; umbonal ridge distinct, sharp, ex- tending nearly to posteroventral margin; beaks widely spaced; liga- mental area wide; ornament of concentric lamellae and_ poorly defined radial ribs, ribs observable only on posteroventral and an- terior portion of valves.
Range. — Pennsylvanian.
Measurements. — Bivalved specimen (mm). Ht. 7.0; Lt 19.0; Isl Wes G70
Material. — Hypotype, U.S. National Museum, No. 155837.
Discussion. — This species, which is represented by a single specimen collected from Bed ten, is readily distinguished from other species of the genus by its sharp anteroventral margin; its low, rounded beaks; and by its faint, irregularly developed radial orna- ment. ‘The Gaptank specimen referred to this species is larger and more convex than Sayre’s specimens and has a hint of radial ribbing on the anterior end of the shell.
Grammatodon carbonaria (Cox), 1857 Pl. 12, figs. 4-9
Arca carbonaria Cox, 1857, Third Rept. Geol. Sur. Kentucky, p. 567, pl. 7 fig. 5.
[Non] Parallelodon carbonaria Morningstar, 1922, Geol. Sur. Ohio, 4th ser., Bull. 25, p. 209.
’
Diagnosis. —Shell elongate, rectangular or slightly expanded posteriorly; anterior margin sharply to gently rounded; posterior
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 141
margin rounded to obliquely truncate, meeting dorsal margin at obtuse to nearly right angle; ventral margin gently arched to nearly straight, gently but distinctly sinuate under umbones, sul- cus shallow; hinge line straight, much shorter than maximum length of shell; dental series unknown; umbones broad, low, but high in relation to total height of valves; umbonal ridge nearly straight, sharp to gently rounded; ligamental area wide, inclined to nearly flat, amphidetic, marked with chevron-shaped grooves; sur- face of valves covered by numerous, rounded, fine, closely spaced radial ribs, nearly equal in weight across valves, and distinct, coarse widely spaced, wrinkled lamellae, with fine, wavy lamellae between.
Range. — Pennsylvanian.
Measurements. — Hypotypes. (mm) .
Ht Lt C LLA(l) WLA(I) B.V. 15.0 29.6 78 (D2 102 0.8 LA 35.2 19.2 5.8 RV. 12.2 25.5 6.3 RV. 12.0 29.1 B.V. 11.9 24.0 9.1 EV. 30 240 6.8
Material. — Hypotypes, U.S. National Museum, Nos. 155838- 155842. Illinois Geological Survey, No. 216. Identified by Dr. J. M. Weller, 1928.
Discussion. — The holotype of this species is lost and no topo- type material, “limestone over coal no. 11 at Providence, Hopkins Co., Kentucky,” is available. ‘The dental series of the species has never been determined; it has, however, the fine radial ribs, the medial sinus, and corresponding sulcus, and the chevron-shaped grooves of the ligamental area characteristic of the family. [In form and ornament, Grammatodon carbonaria closely resembles Permo- phorus pricet (Branson), 1930, a poorly known taxon whose sys- tematic position is obscure.] The chevron ornamentation of the ligamental area in G. carbonaria was observed in only one other- wise poorly preserved specimen collected by J. M. Weller from the St. David Limestone from the Pennsylvanian of Ilinois. This speci-
142 BULLETIN 240
men, and the one figured on Plate 12, figure 9, are deposited at the Illinois Geological Survey Museum.
The radial ribs of Grammatodon carbonaria are restricted to the outer shell layer; slightly corroded specimens appear nearly smooth. The ornament tends to disappear especially on the um- bonal areas and on the posterior portion of the shells. The con- centric ornament consists of widely spaced, coarse lamellae between which are minutely fine, wavy lines which produce tiny nodes at the intersection of radial ribs.
Grammatodon carbonaria attains a large size and shows con- siderable variation in shape, ranging from rectangular to pos- teriorly produced and expanded forms. Several specimens show a tendency to slough off shell layers around the umbones and along the dorsal margins. The result is that the “ligamental area” be- comes extremely wide since younger as well as older portions of this structure are exposed to view. Also the umbones become nar- row and steep on the hinge line side of the valve.
The species is represented by several poorly preserved speci- mens in Bed ten of the Gaptank Formation. Some of the valves are in a slightly coarser matrix than the normal Bed ten fossils, and nearly all specimens are univalved, indicating transportation of these specimens from a higher to a lower energy zone.
Grammatodon biplicata Bird, n. sp. Pl. 12, figs. 10, 11
PR eaee carbonaria Morningstar, 1922, Geol. Sur. Ohio, 4th ser., Bull. 25, inoptae carbonaria Cox, 1857, Third Rept. Geol. Sur. Kentucky, p. 567, oe We ast) Dy Diagnosis. — Shell elongate, rectangular; anterior margin sharp- ly rounded; posterior margin truncate, nearly straight, meeting dorsal margin at nearly right angle; ventral margin gently convex outward, apparently not sinuaie; hinge line straight, nearly as long as valves; dental series unknown; umbones broad, not gibbous; umbonal ridge sharp to low; ligamental area a narrow groove pos- terior to beaks, not observed anteriorly; radial ribs of unequal weight, becoming coarser dorsal to umbonal ridge, coarsest ribs on umbonal ridge, ribs rounded anteriorly becoming flattened pos- teriorly, ribs bifurcated just ventral of midline all across valves, concentric ornament of growth lines only.
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 143
Range. — Pennsylvanian. Measurements. — (Mm).
Ht JL Holotype BVi 13.6 olay Paratype B.V. 11.8 30.5
Material. — Holotype and paratype, Orton Museum Ohio State University, No. 9188. Both collected by Morningstar from the lower Mercer Limestone, near Somerset, Ohio.
Discussion. — This species is based on two bivalved specimens identified by Morningstar as Parallelodon carbonaria (Cox) , 1857. The shape of the two species is close but Grammatodon biplicata has irregularly weighted ribs which are bifid and which become coarse near the umbonal ridge. The radial ornament of G. carbon- aria is regularly developed and the ribs are not bifid. G. biplicata has a hint of a ventral sinus as seen in progressive growth stages, but unlike G. carbonaria, the sinus is located just anterior to the umbonal ridge in G. biplicata.
The valves of Grammatodon biplicata are more elongate in relation to height than in G. erectumbona and in G. biplicata the ribs become coarser at the umbonal ridge while they do not in G. erectumbona.
Family CONOCARDIIDAE Neumayr Genus CONOCARDIUM Bronn, 1835
Diagnosis. — Shell equivalve, inequilateral, slightly opistho- cline; gaping at both ends; anterodorsal margin produced into ros- trum; anterior margin often markedly concave, steeply or gently sloping to ventral margin posterodorsal margin alate, broad, gent- ly concave to convex; ventral margin broadly rounded to acute and narrow; dorsal margin straight, coincides with maximum length of shell; umbones small, sharp; umbonal ridge often a sharp keel; beaks prosogyre, located just anterior to center of hinge line; liga- ment external and possibly internal; anisomyarian; ornament of radial ribs and concentric lamellae, discrepant anterior and_ pos- terior to umbonal ridge.
Type species.—Cardium (Conocardium) elongatum J. deC. Sowerby, 1812. Monotypy (fide Dickens, 1963, p. 105).
Range. — Ordovician-Pennsylvanian, ‘Triassic?
144 BULLETIN 240
Conocardium parrashi Worthen, 1890 Pl. 13, fig. 3 Conocardium parrashi Worthen, 1890, Geol. Sur. Illinois, vol. 8, p. 112, pl. 20, fig. 7.
C. missouriensis Girty, 1915, Missouri Bureau Geol. Mines, 2d ser., vol. 13, p. 353, pl. 28, fig. 3.
C. parrashi (Worthen) , Sayre, 1930, Univ. Kansas Bull., vol. 31, p. 109, pl. 9, fig. 20.
Diagnosis. — Shell small, slightly opisthocline; posterodorsal margin acute; anterior rostrum small; umbones sharply raised; um- bonal ridge sharp, with spines on axis, spines becoming larger ven- trally, ridge gently concave anteriorly; beaks small, indistinct, slightly prosogyre; ornament anterior to umbonal ridge of coarse costae, nodose, bifurcated near margin of shell, posterior to um- bonal ridge, costae more numerous and finer, crossed by numerous, fine, distinct concentric lines to give cancellate appearance.
Range. — Pennsylvanian.
Measurements. — Hypotypes, (mm).
Ht Let G B.V. Wee: Tell 6.8 B.V. 7.0 6.8 B.V. 4.9 3.8 Sez
Material. — Hypotypes, U.S. National Museum, No. 155843.
Discussion. —"The distinguishing characteristics of this species are its small size, its spiny umbonal ridge, its slight backward obliquity and its highly discrepant ornamentation anterior and pos- terior to the umbonal ridge. Conocardium carinatum Hall, 1856 from the Mississippian of Indiana has the bifid posterior costae of C. parrashi, but C. parrashi is not so opisthocline as C. carinatum and has cancellate ornamentation anterior to the umbonal ridge while C. carinatum has only costellae in this zone.
Family PTERIIDAE Meek Genus PTERIA Scopoli, 1777
Diagnosis. — Shell strongly inequivalve, left valve more convex than right, obliquely elongate, prosocline, alate; posterior ear larger than anterior ear; anterior ear with shallow byssal notch; hinge line long; two teeth in each valve; ligament external; adults monomyarian; ornament of growth lines and fila, some forms with one or more ridges on the anterior margin.
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 145
Type species.— Mytilus hirundo Linnaeus. Original designa- tion.
Range. — Devonian-Recent.
Pteria longa (Geinitz), 1866 Pl. 13, fig. 6 Gervillia longa Geinitz, 1866, Carb and Dyas in Nebraska, p. 32, tab. 2, fig. 15. Avicula longa (Geinitz), Meek, 1872, U.S. Geol. Sur., Nebraska, Final Rept., p.
199, pl. 9, fig. 8.
Pteria longa (Geinitz), Beede, 1900, Univ. Geol. Sur. Kansas, vol. 6, p. 125, pl. 16, fig. 4; Sayre, 1930, Bull. Univ. Kansas, vol. 31, p. 100, pl. 9, figs. 13-14. Diagnosis. — Shell elongate, narrow; strongly prosogyre; pos-
terior margin beyond auricle nearly straight, inclined; anterior mar- gin subparalled to posterior margin; ventral margin broadly round- ed; umbones strongly inclined, rather gibbous, meeting hinge at highly oblique angle; umbonal folds both well defined, sharp; an- terior ear much smaller than posterior, posterior ear straight along dorsal margin, gently concave outward at posterior margin; orna- ment of fine, distinct fila, extending regularly onto auricles and following contour of them.
Range. — Pennsylvanian.
Measurements. — Hypotype, right valve, (mm). Ht. 11.0; Lt 13105 ERA] 10:0; EIPA 4.4
Material. — Hypotype, U.S. National Museum, No. 155844.
Discussion. — ‘This species is easily distinguished from Pteria sulcata (Geinitz) , 1866 by its shape and ornament. ‘The posterior margin of P. sulcata is concave and the anterior margin is convex so that the shell expands posteriorly and becomes increasingly more prosocline posteriorly in a manner reminiscent of Monopteria. In P. longa the posterior and anterior margins are nearly parallel and the shell does not expand posteriorly nor become more strongly prosocline. Pteria longa lacks the alternating grooves and ridges under the anterodorsal margin and the coarse, wavy concentric lines of P. sulcata.
The shape of P. longa is more similar to that of P. welleri Sayre, 1930; Sayre’s species has one or more ridges near the antero- dorsal margin, however, and tends to have a smaller posterior auricle in relation to shell size than does P. longa. Finally, Sayre (1930, p. 111) stated that his species has a reticulate ornament on the posterior auricle. Noncorroded specimens, at least, of P. longa, do not have reticulate pattern of the posterior ear.
146 BULLETIN 240
A fragmentary bivalved specimen and a nearly perfect right valve of this species were collected from Bed ten of the Gaptank Formation.
Family INQUIRENDA
Genus and species indeterminate Pl. 13, fig. 7
Diagnosis. — Slightly inequivalve left valve more convex than right, inequilateral, subtrigonal, extremities of dorsal margin auricle-like; anterior margin short, rounded; posterior margin near- ly as high as maximum valve height; ventral margin gently round- ed; umbones prominent, pointed, extending high above anterior portion of hinge, not markedly raised above posterior portion; um- bonal folds prominent; ligament, muscle scars and pallial line un- known; ornament of two valves possibly discrepant, both valves with fine fila, left valve with subdued, wide costae on ventral mar- gin only.
Measurements. — Bivalved, (mm). Ht 15.7; Lt 16.5; C 9.1.
Material. — U.S. National Museum, No. 155845.
Range. — Bed ten of Gaptank Formation.
Discussion. — With all critical features of this species concealed it is not possible to assign it to a genus or yet even a family with any degree of certainty. Externally the form is unlike any Upper Paleozoic bivalve and should warrant erection of a new genus were the single, bivalved specimen representing it better preserved or had there been more specimens of the species.
Family MYTILIDAE Fleming Genus PROMYTILUS Newell, 1942 Type species. —Promytilus annosus Newell, 1942. Original designation. Range. — Carboniferous-Permian, Mesozoic?
“Promytilus” postumbonus Bird, n. sp. P38) Lene Diagnosis. — Equivalve, thin-shelled, subovate; anterior lobe
distinct, large; posterior margin broadly rounded; ventral margin gently convex, with a distinct, deep sinus located under the um- bones and a corresponding sulcus extending over one-half distance from ventral to dorsal margin; dorsal margin short, forming a sharply acute angle with ventral margin at anterior end; umbones prominent, gibbous at anterior one-third of hinge; umbonal ridge
TEXAS PENNSYLVANIAN PELECYPODsS: BIRD 147
broadly rounded, inflated, distinct; shell smooth except for growth lines and irregularly spaced lamellae.
Range. — Bed ten of the Gaptank Formation.
Measurements. — Holotype, bivalved, (mm). Ht 10.4; Lt 15.0; HS 4:2) MLS) 4.3; © 7.1:
Material. — Holotype, U.S. National Museum, No. 155846.
Discussion. — ‘The taxonomic position of this species is un- certain. The microstructure of the single specimen of the species is recrystallized. Because no evidence of a duplivincular ligament can be observed, the species is assigned to the Mytilidae rather than to the Myalinidae. The characters of “Promytilus” postum- bonus appear to be midway between the characters of Newell's (1942) Promytilus and Volsellina, two genera which may need revision Or may prove to be unnecessary when more Upper Paleo- zoic mytiloids become known. The character of “P.” postumbonus which it shares with typical representatives of Promytilus, is the distinct ventral sinus and corresponding sulcus. With the two orig- inally designated species of Volsellina, “Promytilus” postumbonus shares the posterior of terminal position of the beaks. Though New- ell (1942, p. 37) inferred otherwise in his proposed evolutionary sequence from Promytilus to Mytilus, it is suggested that the ventral sinus, produced in response to the formation of byssal threads, 1s a more important index to classification than position of the beak. Therefore, this taxon is tentatively referred to Promytilus rather than to Volsellina, which has only a vague ventral sinus. However, “P.” postumbonus certainly departs from typical representatives of the genus in its convex rather than concave ventral margin, which contracts rather than expands posterior to the ventral sinus so that in “P.” postumbonus there is no spatulate aspect to the shell. Fur- ther, the shell of representatives of Promytilus are smooth while that of “P.” postumbonus is marked with distinct concentric lines. In these last two respects “P.” postumbonus is more like represen- tatives of Volsellina.
Recently, Dickens (1963, p. 60) also described a_ species, Modiolus koneckii, from the Permian of Western Australia, which he regards as morphologically intermediate to Newell’s Volsellina and Promytilus. Dickens’ species, however, can not be confused with “P.” postumbonus; the former species has a more spatulate shape
148 BULLETIN 240
and is longer with relation to height and has radial ornament. The systematic position of “P.” postumbonus as intermediate between Promytilus and Volsellina was deduced before I saw Dickens’ work thereby adding doubt to the need for Newell’s two genera.
“Promytilus” postumbonus is not closely related in morphology to any known Paleozoic species. It is remarkably similar to Modiolus johnson: (Whitfield) , 1885 from the Cretaceous of Maryland. ‘This similarity strongly attests to Newell’s (1942, p. 36) observation concerning the extreme conservation in external shape of this group of organisms.
A single bivalved specimen of this species is the sole represen- tative of the Mytilacea in Bed ten of the Gaptank Formation. ‘The rarity of the superfamily Mytilacea, a common element in many Pennsylvanian faunas, is to be expected. According to Newell (1942, p- 19) and Yochelson (personal communication) the mytiloids are typically shallow-water inhabitants and seem to always have been euryhaline. The common occurrence of mytiloids in the bivalve con- dition indicates that they preferred, in ancient as well as in mod- ern times, areas where the water was quiet, 7.e., shallow-water areas protected from vigorous wave activity such as lagoons and estuaries where species of the family Mytilidae are most common today (all members of the Myalinidae are extinct). The Bed ten fauna indi- cates that the water depth was too great for mytiloids to be well represented.
Family MODIOMORPHIDAE Miller Genus GONIOPHORA Phillips, 1848
Diagnosis. — Equivalve, inequilateral, subrectangular to subtri- gonal; anterior margin rounded to nearly straight; posterior mar- gin truncated obliquely; ventral margin nearly straight to highly sinuate; hinge with central tooth in right valve, corresponding groove in left valve; ligament external, opisthodetic; lunule and escutcheon well formed; beaks small, strongly prosogyre, incurved; umbones prominent, umbonal ridge sharp, extending without re- duction in prominence to posteroventral margin; pallial line en- tire; adductors subequal; ornament of concentric lamellae, radial striae or growth lines only.
‘TEXAS PENNSYLVANIAN PELECYPODs: BIRD 149
Type species. —Cypricardia cymbaeformis J. de C. Sowerby, 1839. Original designation.
Range. — Devonian-Permian.
Discussion. — Post-Devonian species of this genus tend to be small. In addition, these forms tend to have a highly sinuate ven- tral margin, great convexity in relation to length of valves, and maximum convexity located high on shell. Species illustrating these features are the apparently closely related G. crista Chronic, 1952 from the Kaibab Formation; G. acutacarinata (Armstrong), 1865 (in Hind, 1899, p. 359, pl. 39, figs. 14-19) from the Upper Lime- stone Series of Scotland; and G. gnoma Bird, n. sp. from the Gap- tank Formation. This group may prove to deserve generic or sub- generic status with further investigation.
Goniophora gnoma Bird, n. sp. Pl. 13, fig. 5
Diagnosis. — Shell small, subtrigonal; anterior margin round- ed; posterior margin narrow, scarcely more than being the inter- section of dorsal and ventral margins; ventral margin convex an- teriorly, becoming concave posterior to umbones; flattened perpen- dicularly to the plane of commissure; dorsal margin convex; slop- ing steeply posterior to beaks, lunule and escutcheon deep, prom- inent; umbones broad; umbonal keel acute, posterodorsally is an- other acute keel; beaks nearly terminal, strongly incurved; smooth except for growth lines.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm) .
Ht Lt C Holotype BV. 3,5 6.4 ee: Paratype Bev 4.6 6.3 Oe)
Material. — Holotype, U.S. National Museum, No. 155847. Paratype, U.S. National Museum, No. 155848.
Discussion. — This species, represented by two bivalved speci- mens from Bed ten of the Gaptank Formation, somewhat re- sembles Goniophora acutacarinata (Armstrong), 1885 but is read- ily distinguished from it by having two umbonal keels and a greatly reduced posterior margin. The latter feature gives G. gnoma a tri- gonal shape. In shape and size G. gnoma is closely similar to G.
150 BULLETIN 240
crista Chronic, 1952 but is distinguished from Chronic’s species by its two umbonal keels and by its complete lack of concentric lam- ellae.
Family AVICULOPECTINIDAE Etheridge, Jr. Subfamily AVICULOPECTININAE Meek and Hayden Genus ACANTHOPECTEN Girty, 1903 Type species. —Pecten carboniferus Stevens, 1853. Original designation. Range. — Mississippian-Permian.
Acanthopecten carbeniferus (Stevens), 1858 Pl. 13, figs. 16, 17
Pecten carboniferus Stevens, 1858, American Jour. Sci. (2), vol. 25, p. 261.
Aviculopecten (Acanthopecten) carboniferus (Stevens) , Girty, 1903. U.S. Geol. Sur., Prof. Paper 16, p. 418.
Acanthopecten carboniferus (Stevens), Newell, 1937 (1938), State Geol. Sur.
Kansas, vol. 10, pt. 1, p. 72, pl. 12, figs. 8-10.
Diagnosis. — Shell shape variable, usually suborbicular; an- terior margin rounded becoming gently concave near auricle; pos- terior margin nearly straight from anteroventral margin to auricle; ventral margin rounded, cuspate; umbones sharp, distinct; anterior umbonal folds distinct; posterior umbonal fold poorly defined; posterior auricle small, anterior auricle elongate, subtriangular; left valve with broad costae with gently sloping flanks, each topped with narrow, rounded costella, crossed by regular coarse fila which swing down in sharply defined troughs to form ventrally pointing spines; at least anterior auricle costate with fila produced into spines ventrally, strongly notched for byssus; ornament of right valve dis- similar to left, consisting of widely spaced, narrow, costellae, inter- spaces nearly flat, fila absent.
Range. — Pennsylvanian.
Measurements. — Hypotypes (mm) .
Ht IL LAA C R.V. 13e2 Wd 10.3 Ile \ We 14.0 20.3 4.0
Material. — Hypotypes, U.S. National Museum, Nos. 155849, 155850.
Discussion. — A rare right valve along with a well-preserved left valve and an external replica of a left valve are at hand from
TEXAS PENNSYLVANIAN PELECYPODs: BrirpD 151
Bed ten of the Gaptank Formation. The ornamentation of the valves is highly discrepant; the anterior auricle of the right valve is more than one-half as long as the shell itself and has four strong costae, the most dorsal one is strongest. ‘The upper umbonal surface of the left valve shows that, in early stages of growth, ornamenta- tion consists of costellae and normal fila. The result is a pattern of ornament similar to typical species of Streblopteria (Streblochon- dria). A short distance ventrally the riblets are nodose at the inter- sections with the fila and within four or five fila ventrally, they become pointed in the troughs and arched over the costellae. The
costellae at the same time are thickened so that the adult pattern is assumed.
Genus ANNULICONCHA Newell, 1937 (1938) Type species. — Aviculopecten interlineatus Meek and Wor- then, 1860. Original designation. Range. — Mississippian-Permian.
Annuliconcha interlineata (Meek and Worthen), 1860 _—~Pl. 13, figs. 14, 15
Aviculopecten interlineatus Meek and Worthen, 1860, Acad. Nat. Sci. Phila- delphia, Proc. p. 454; 1866, Geol. Sur. Illinois, vol. 2, p. 329, pl. 26, fig. 7.
Posidonomya lasallensis Miller and Gurley, 1896, Illinois State Mus. Nat. His- tory, Bull. 11, p. 12, pl. 1, figs. 17, 18.
Annuliconcha interlineata (Meek and Worthen), Newell, 1937 (1938), State Geol. Sur. Kansas, vol. 10, pt. 1, p. 76, pl. 13, figs. 6-10. Diagnosis. — Shell essentially circular, acline or gently proso- cline; anterior, posterior, and ventral margins gently rounded; um- bones breadly rounded; umbonal folds distinct; auricles triangular; ornament of shell body of raised concentric ridges and interspaced fila; concentric ornament extending onto auricles, in auricular sulcii ornament bends toward umbones then turns outward to parallel outer surface of auricles.
Range. — Pennsylvanian.
Measurements. — Height and length of specimens of this species are nearly equal. No specimens at hand have complete auricles.
Material. — Hypotype, U.S. National Museum, No. 155851.
Discussion. — ‘This species is the most common of the Gaptank pectinoids. Besides the ten adult specimens, what appear to be spat of Annuliconcha interlineata occur on some adult pectinoid speci- mens. One such spat on the posterior auricle of the left valve speci-
152 BULLETIN 240
men of Acanthopecten carboniferus mentioned above is almost cer- tainly a specimen of Annuliconcha interlineata. Presumably, young individuals of A. interlineata settled on older members of their species and on other pectinoids and possibly on other organisms or on hard substrate and attached themselves by byssal threads. Sub- sequently, the attachment was severed and the organism again be- came free. Hence only the young are found attached to other shells and this attachment — which appears to be accomplished by cemen- tation of one valve —is probably effected by byssal threads. The apparent cementation is the result of diagenesis. If this interpre- tation is correct, the spat were attached tightly or were inhabitants of quiet water so that after death they were not dislodged from their hosts. The spat have been most frequently seen on auricles of adult pectinoids.
Genus CLAVICOSTA Newell, 1937 (1938) Type species. — Clavicosta echinata Newell, 1937 (1938). Orig-
inal designation. Range. — Pennsylvanian-Permian.
Clavicosta cf. C. echinata Newell, 1937 Pl. 18, figs. 10, 11 Clavicosta echinata Newell, 1937 (1938), State Geol. Sur. Kansas, vol. 10, pt.
1, p..79, pl. 13, figs. 1-5.
Clavicosta sp. Mudge and Yochelson, 1962, U.S. Geol. Sur., Prof. Paper 332, p- 90, pl. 16, fig. 3.
Range. — Pennsylvanian-Permian.
Measurements. — Hypotype, right valve (mm). Ht 15.1, Lt 13.0.
Material. — Hypotypes, U.S. National Museum, Nos. 155853, 155854.
Discussion. — Two separate presumably right valves and an ex- ternal replica from Bed ten of the Gaptank Formation are re- ferred to this taxon. The specimens appear to be inclined, and because opisthocline shells are not known for the subfamily Avi- culopectininae, it is inferred that they are slightly prosocline. In none of the three specimens is the hinge or auricles preserved, and it was at first thought that these shells were a species of Pseudo- monotis such as P. hawnt (Meek and Hayden), 1858. Pseudomono- tids are also prosocline. The hinge area of species of Pseudomonotis are commonly poorly represented because of the attachment of
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 153
these forms to the substrate. However, if the specimens here con- sidered are truly prosocline, they are right valves, and right valves of species of Psewdomonotis are flat or only slightly convex while the specimens at hand are decidedly convex. Further, the ornament, though similar to that of Psewdomonotis hawni, is consistent rather than varied and the costae are tuberculose instead of scaly. Finally, none of the specimens at hand show attachment scars at the um- bonal area on what is presumed to be the right valve.
Well-preserved bivalved representatives of Psewdomonotis and Clavicosta are readily distinguished. Both valves of species of Clavi- costa are convex and neither valve was attached, while the right, attached valve of species of Pseudomonotis is typically flat or con- cave.
The ornament of the specimens from Bed ten of the Gaptank Formation shows the characteristic features of the genus, coarse costae between which occur two somewhat depressed slightly finer costae. From these specimens it could not be determined that the costae were, respectively first and second order. The coarse costae of these specimens are sharp crested and ornamented by a series of slightly overlapping tubercles. The tubercles are irregularly spaced with the rounded apex situated on the costae and directed dor- sally; the prongs extending ventrally down the flanks of the costae. The tubercles become shorter, hence more numerous and the costae and the tubercules become finer posteriorly. Between the major costae, the minor costae are less elevated, narrower, and more gently rounded than the major ones. The fine ornament reported by Newell is not present on these specimens. The finer costae are closer to the major one on either side than they are to each other. Both sets of ribs extend deep into the shell structure producing a rumpling of the entire shell material present at the ventral margin.
Subfamily STREBLOCHONDRIINAE Newell Discussion. — The three proposed genera of the subfamily can be distinguished only with considerable difficulty. Each of the genera has been recognized from Mississippian faunas and yet by Upper Pennsylvanian time divergence between the genera has not produced distinct generic boundaries or, alternately, the genera are polyphyletic. Because of this lack of distinction Streblochondria
154 BULLETIN 240
Newell, 1937 (1938) and Obliquipecten Hind, 1903 are here treat- ed as subgenera of Streblopteria McCoy, 1851.
Species of Streblopteria s. s. are characterized by having no trace of radial ornamentation on the shell body and only vague ribbing on the anterior auricles; the posterior auricles are much re- duced. Species of Streblopteria (Streblochondria) typically have well-developed ornament on the shell body and on the auricles; here too the posterior auricle may be nearly obsolete. In the type species and closely related species of Streblopteria (Streblochondria) the shell body is ornamented by distinct fila and closely spaced costellae to produce a cancellate effect. Other species questionably referred to this subgenus have microscopic cancellate ornamentation on the upper umbonal surface only, have weak costellae, or are smooth. A new species from the Gaptank Formation, Streblopteria (Streblochondria) fila, has prominent fila and weak costellae which become slightly better developed anteriorly. Another new species, S. (Streblochondria) semicosta, has only growth lines and costellae restricted to the anterior portion of the shell body and has distinct costae on the anterior auricle. In short, the range of ornamentation in species of S. (Streblochondria) is from smooth to only concentric io both concentric and radial to the peculiar, microscopic cancellate ornament of Streblopteria (Streblochondria)? tenuilineata (Meek and Worthen) .
Streblopteria (Obliquipecten), the third subgenus of the sub- family, is poorly known. Only recently has it been known from ma- terial other than the type species from the Lower Carboniferous of England. Ciriacks (1963, p. 55) reported a species of Obliquipecten from the Permian of Wyoming and two specimens, a left and a right valve, from the Gaptank Formation are here referred to the sub- genus. The Gaptank specimens are not flat like the type species but do have the marked backward obliquity and the obsolete pos- terior auricles of the type species. The umbones are prominent and gibbous. Distinction between Streblopteria (Streblopteria) and Streblopteria (Obliquipecten) is based primarily upon the degree to which the posterior auricles is reduced and the degree of back- ward obliquity of the shell. Species of S. (Obliquipecten) have only
‘TEXAS PENNSYLVANIAN PELECYPODs: BIRD 155
the slightest hint of posterior auricles or none at all and the shell is markedly opisthoctine.
Genus STREBLOPTERIA McCoy, 1851 Subgenus STREBLOPTERIA McCoy, 1851
Type species. —Meleagrina laevigata McCoy, 1844. Subsequent designation Meek and Worthen 1866, fide Newell [1937, (1938) , p- 88].
Range. — Mississippian-Permian.
Streblopteria (Streblopteria) obliqua Bird, n. sp. Plate 13, fig 12
Diagnosis.— Shell higher than long, strongly opisthocline; dorso-anterior margin gently concave outward; anterior margin short ventrally, sharply rounded; posterior margin sharply rounded, but gradually rounded to meet posterior auricle; umbones distinct, not gibbous; anterior umbonal fold distinct; posterior umbonal fold obscure; posterior auricle indistinctly set off from shell body, higher than long; anterior auricle incompletely preserved; shell and auricles smooth except for irregularly thickened lamellae.
Range. — Bed ten of Gaptank Formation.
Measurements. — Holotype, right valve (mm). Ht 20.9; Lt S352 @) 4:6; Ol 0 48.
Material. — Holotype, U.S. National Museum, No. 155855.
Discussion. — The presence of a posterior auricle and posterior umbonal fold of the single specimen of this highly opisthocline species favors its designation to Streblopteria (Streblopteria) rather than to the subgenus Obliquipecten. The valve is, however, flat- tened. Though the shell layers are well preserved, there is no hint of ornamentation besides growth lines.
The growth lamellae show that S. (Streblopteria) obliqua be- comes relatively shorter with respect to length. The posterior por- tion of the shell is the faster growing of the heterogenous charac- ters, height and length, so that the shell becomes more strongly opisthocline with advancing ontogeny.
Streblopteria (Streblopteria) sp. Pl. 14, figs. 1, 2
Diagnosis. — Shell high in relation to length, opisthocline; anterior margin gently rounded, rumpled near dorsal extremity;
156 BULLETIN 240
posterior margin gently rounded, meeting dorsal margin at slightly obtuse angle; ventral margin gibbous, prominent; posterior um- bonal fold indistinct; anterior umbonal fold undefined; posterior auricle tiny, obsolete; anterior auricle not observed; ornament ab- sent except for growth lines.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm) .
Ht Lt ¢ Ol R.V. 25.7 19.6 4.] 0.75 RAVE 20.1 19.7 4.5 0.81
Material. — U.S. National Museum, Nos. 155856, 155857.
Discussion. — "Two right-valved specimens, which are prob- ably conspecific, are tentatively placed in this genus. Both speci- mens are fragmentary. One is crushed anteroventrally so that it appears to have a distinct anterior umbonal fold. The shell has largely been broken away anterior to this region. The actual shell margin can be seen in the limy matrix, however, and shows that the apparent umbonal fold is not real. ‘The smaller specimen lacks a ventral margin, and the tip of the umbone has been broken so that this structure appears too low.
Subgenus STREBLOCHONDRIA Newell, 1937 (1938) Type species. — Aviculopecten sculptilus Miller, 1891. Original designation. Range. — Mississippian-Permian. Streblopteria (Streblochondria) aff. S. (Streblochondria) sculptilus
(Miller), 1891 Pl. 13, fig. 13
Aviculopecten sculptilus Miller, 1891, Indiana Geol. Sur., Ad. Sheets, 17th Rept., p. 92, pl. 20, fig. 5.
Streblochondria sculptilus (Miller), Newell, 1937 (1938), State Geol. Sur. Kan- sas, vol. 10, pt. 1, p. 82, pl. 16, figs. 5, 7, 9, 11.
Discussion. —One specimen of this species was collected from Bed ten of the Gaptank Formation. The shell body of the specimen is nearly complete, but the auricles are wanting. Streblochondria sculptilus differs from S. hertzeri (Meek), 1871 mainly in being higher in relation to length and in having a smaller umbonal angle. S. sculptilus is distinguished from S. stantonensis Newell, 1937 (1938) only by the nature of the auricles which are not pres- ent in the specimen at hand.
TEXAS PENNSYLVANIAN PELECYPODS: BiIRD 157
Range. — Missourian.
Measurements. — Hypotype, right valve, (mm). Ht 12.7; Lt 9.5; Gilet.
Material. — Hypotype, U.S. National Museum, No. 155858. Streblopteria (Streblochondria) fila Bird, n. sp. Pl. 14, figs. 7, 8
Diagnosis. — Shell subcircular, distinctly though slightly opis- thocline; umbones prominent, moderately gibbous; anterior um- bonal fold prominent, posterior umbonal fold gradually rounded, distinct; anterior auricle longer than high, much longer than pos- terior auricle, byssal notch apparently well developed; convexity high; ornament of shell body of prominent, regular, closely spaced fila and faint radial lines, radial ornament most prominent under anterior auricle where the fine costellae are sharply raised and closely spaced; auricular ornament not known.
Range. — Bed ten of Gaptank Formation.
Measurements. — Holotype, right valve, (mm). Ht 14.0; Lt 475 JbvAVA\ Dobe ILI Bey Zao (0; ae (ONL sil)
Material. — Holotype, U.S. National Museum, No. 155859. Paratype, U.S. National Museum, No. 155860.
Discussion. —This species fits in well with the apparent sub- generic trend to a more orbicular outline. The trend is the result of the reduction of height in relation to length of shell. There is no recognizable trend in the type of ornamentation in species of Streblochondria. S$. (Streblochondria) fila has subdued radial orna- ment.
Streblopteria (Streblochondria) fila is represented by two right valves. One specimen is nearly complete, the anterior auricle is covered by matrix and the posterior extremity of the posterior ear is missing. The species is distinctive for its high convexity and its ornamentation. The regularly spaced fila are strongly developed and crossed by closely spaced, feebly developed radial riblets. ‘The characteristic cross-hatched effect commonly seen in the genus is not displayed because of the jack of development of the radial ornament. Anteriorly, the radial riblets are relatively sharply raised but even here they are subdued and narrow. The nature of orna- mentation of S. (Streblochondria) fila most closely conforms to that of S. (Streblochondria) hertzert (Meek) , 1871 but S. (Streblo-
158 BULLETIN 240
chondria) fila has a higher convexity and is more orbicular than that species. As in S. (Streblochondria?) tenuilineata (Meek and Worthen) , 1860 the outer ostracum of the shell is coarsely devel- oped. The shell structure is radial crossed lamellar and can be easily seen with a hand lens.
Streblopteria (Streblochondria?) tenuilineata (Meek and Worthen), 1860 Pl. 14, figs. 3-6
Pecten tenuilineatus Meek and Worthen, 1860, Acad. Nat. Sci. Philadelphia, Proc., p. 452.
Streblopteria? tenuilineata Meek and Worthen, 1866, Geol. Sur. Illinois, vol. 2, p- 334, pl. 26, fig. 9.
Crenipecten foerstii Herrick, 1887, Denison Univ. Sci. Lab., Bull., vol. 2, p. 28, pl. 3, fig. 9.
Crenipecten foerstii (Herrick), Morningstar, 1922, Ohio Geol. Sur., Bull. 25, 4th ser., p. 230, pl. 13, figs. 7-8.
Streblopteria tenuilineata (Meek and Worthen), Sayre, 1930, Kansas Geol. Sur., Bull. 17, p. 121, pl. 11, fig. 3.
Streblochondria? tenuilineata (Meek and Worthen) , Newell, 1937 (1938), State Geol. Sur. Kansas, vol. 10, pt. 1, p. 84, pl. 1, fig. 3; pl. 15, figs. 10-16. Diagnosis. — Shell suborbicular, acline or slightly opisthocline
to strongly opisthocline; anteroventral margin rounded to nearly Straight, anterior margin near auricles concave outward, posterior margin broadly rounded; umbones gibbous; beaks orthogyre to prosogyre; anterior and posterior umbonal folds well defined; pos- terior auricles subquadrate, anterior auricles longer, rounded at extremities; shell body of both valves with microscopic cancellate ornament on dorsal part of umbones, absent elsewhere; posterior auricle normally with four or five broad or narrow distinct costae, with or without concentric ridges, posterior auricle with only con-
centric Ornament or no ornamentation. Range. — Pennsylvanian.
Measurements. — Hypotypes (mm) .
Ht Lt LAA LPA Ol Ie R.V. 18.0 16.5 5.0 4.0 0.98 2: REV: ea 19.6 73 Atay 0.54 Be R.V. 17.8 17.6 5.8 3.0 0.64 a L.V. 17.1 We 4.8 4.6
Material. — Hypotypes, U. S. National Museum, No. 155861. Orton Museum of the Ohio State University, No. 15289.
Discussion. —One fragmentary right valve of this species was
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 159
found in Bed ten of the Gaptank Formation. This valve bears the microscopic cancellate ornamentation of the umbonal area that has been previously reported for the left valve.
Newell’s [1937 (1938), p. 84] citation of Crenipecten foersti Mark is a misprint for C. foersti2 Morningstar. Morningstar's three specimens of this species were kindly loaned to me by Dr. Schopf of the Orton Museum, Ohio State University. These specimens, as noted by Newell (op. cit., p. 85), are highly oblique for Sireblop- teria (Streblochondria?) tenuilineata; also these specimens, because of preservation, show no trace of the umbonal ornamentation so characteristic of the species. According to Newell (loc. cit.), topo- types of Herricks Crenipecten foerstit, which like Morningstar's specimens, are from the Pottsville Series of Flint Ridge, Ohio, are conspecific with S. (Streblochondria?) tenuilineata. However, based on Newell’s figures (op. cit., pl. 15, figs. 10-13) as well as on Morn- ingstar’s specimens, the auricular costae of the Ohio forms are much more distinct and narrow and the umbones are lower (project less above the shell body). The auricles of the Pottsville form are not so high in relation to their length as Middle Pennsylvanian repre- sentatives of S. (Streblochondria?) tenuilineata. The Ohio forms may prove to be a distinct species or at least subspecies.
As in specimens of Streblopteria (Streblochondria) fila, the structure of the outer ostracum in S$. (Streblochondria?) tenuiline- ata is coarsely radial cross lamellar and can be seen throughout the shell with slight magnification.
Streblopteria (Streblochondria) semicosta Bird, n. sp. Pl. 13, fig. 9
Diagnosis. — Shell small opisthocline; anterior margin short, gently rounded ventrally, gently concave upward and outward dorsally; ventral and posterior margins rounded; umbones high, gibbous; umbonal folds prominent; posterior auricle short, sub- quadrate; anterior auricle relatively large, convex rather than flat, rounded anteriorly; byssal notch distinct but shallow; anterior margin of shell body ornamented by fine, low, radial ribs, ribs be- coming obsolete dorsally near base of anterior ear, additional fainter ribs situated posterioventrally restricted to ventral margin, general surface with fine lines of growth only; anterior auricle with six long costae extending from tip to base of ear, crossed by numerous growth lines, ribs not present on dorsal one-third of ear.
160 BULLETIN 240
Range. — Bed ten of Gaptank Formation.
Measurements. — Holotype, right valve (mm). Ht 11.6; Lt O03 IGANAN 4208 Ibe 210s OL Woo.
Material. — Holotype, U. S. National Museum, No. 155862.
Discussion. — The costate anterior auricle and the faint but dis- tinct anterior costation of the anterior part of the shell body bring me to place this species in the subgenus Streblochondria. ‘This unique ornamentation distinguishes this species, which is repre- sented by a single right valve, from any known species of the genus.
Subgenus OBLIQUIPECTEN (Hind), 1903 Type species. — Obliquipecten laevis Hind, 1903. Original des- ignation. Range. — Mississippian-Permian. Streblopteria (Obliquipecten) sp. Pl. 14, figs. 10, 11
Diagnosis. — Shell suborbicular, higher than long, strongly opisthocline; anterior margin gently rounded, strongly concave outward under beaks; posterior and ventral margins gently round- ed; umbones prominent, gibbous, extending high above anterior margin; beaks prosogyre; anterior umbonal fold prominent; pos- terior umbonal fold absent; left valve with small, poorly defined anterior wing; anterior auricle of right valve apparently broken off; posterior auricles absent; ornament of right valve lacking; left valve with distinct, closely spaced, flattened costae on anteroven- tral portion of shell, becoming obsolete a short distance dorsally.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm). Ht Lt C Ol IREVe 30.2 21.8 Test 0.33 IEW, 22.0 15.0 6.5 0.27
Material. — U.S. National Museum, Nos. 155863, 155864.
Discussion. —'The two valves are tentatively referred to the same species. The species is placed in the subgenus Obliquipecten be- cause of the shape and strongly opisthocline attitude of the shell, the radiating costae of the anterior portion of the left valve, the lack of a posterior ear on the right valve, and the triangular liga- mental area of the right valve which 1s set posterior to the beaks as that of the left valve illustrated by Newell (1937, p. 90, 1h, BZ)
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 161
The specimens collected from the Gaptank Formation do not have the flattened umbones nor flattened valves of the type species. Family INQUIRENDA Genus CYPRICARDINIA Hall, 1859
Type species. — Cypricardinia lamellosa Hall, 1859; subsequent designation by Hall (1885, p. xvi).
Range. — Devonian-Permian.
Discussion. — Several students of Paleozoic Pelecypoda (see Dickens, 1963, p. 98) have expressed doubt as to whether the name Cypricardinia should be used for Upper Paleozoic pelecypods. Un- like earlier forms, Upper Paleozoic species referred to Cypricardinia have equal valves and a marginal rather than an external liga- mental area (Dickens, 1963, p. 98) . In general external morphology, Upper Paleozoic and Devonian representatives of the genus are much alike, Because further study is needed to show the differences noted above to be consistent, the genus Cypricardinia is used here without recourse to open nomenclature.
Cypricardinia questa Bird, n. sp. Pl. 12, fig. 3
Diagnosis. — Shell oblong, thin, slightly expanded posteriorly; anterior short, gently rounded; posterior margin sharply rounded ventrally but gradually rounding into dorsal margin; ventral margin gently convex; dorsal margin straight, shorter than maxi- mum length of shell; umbones small, gently inflated; umbonal ridge distinct near beaks, becoming rounded and indistinct pos- teriorly; ligamental area narrow, amphidetic; beaks small, proso- gyre; ornament of numerous, regularly spaced, gently raised, imbri- cated concentric lamellae with fine, regular lines between, radial ornament absent.
Range. — Bed ten of Gaptank Formation.
Measurements. — Holotype, bivalved, (mm). Ht 12.0; Lt 11.0; DBAM 1.6; C 8.8.
Material. — Holotype, U. S. National Museum, No. 155865.
Discussion. — Cypricardinia questa does not closely resemble any known species of the genus. Its total lack of radial ornamenta- tion is apparently unique. ‘This condition is not the product of cor- rosion for the ornament is in an excellent state of preservation. Cypricardinia questa is distinguished from C ? elegantula Dickens,
162 BULLETIN 240
1963 by having a less spatulate outline, more prominent umbones, more regular concentric ornament, and its lack of radial costation. The general shape of C. questa is close to that of the type species, C. lamellosa Hall, 1859, but C. questa has much higher beaks and again has no radial ornament.
Cypricardinia questa 1s represented by a single, broken, bi- valved specimen from Bed ten of the Gaptank Formation.
Family MYOCONCHIDAE Newell Genus STUTCHBURIA Etheridge, Jr., 1900
Type species. — Orthonota? costata Morris, 1845. Original des- ignation.
Range. — Pennsylvanian-Permian.
Discussion. — Newell (1957) and Dickens (1963) have studied the type species of this genus and found it to possess poorly de- veloped, obsolescent, cardinal teeth. Newell recognized one cardinal tooth in each valve; Dickens two in the left and one in the right valve. In addition there are two posterior laterals in the right valve and one in the left. Permophorus Chavan, 1954 — Pleurophorus King, 1850 is a closely related genus distinguishable by its better developed cardinal dentition.
No teeth were observed on the species here tentatively re- ferred to Stutchburia, yet most of the hinge was observable on one specimen.
“Stutchburia” corrucostata Bird, n. sp. Jedi alal, sukees We Jelly 114 roles, IL
Diagnosis. — Shell subrectangular; anterior margin gently rounded; posterior margin obliquely truncate; ventral margin gent- ly convex; dorsal margin nearly straight; umbones low, broad; umbonal ridge indistinct; ligamental area narrow, opisthodetic, marginal rather than external; lunule small, well defined, escutch- eon indistinct; ornament of coarse costae, becoming coarser pos- teriorly and concentric lamellae; costae wider than interspaces.
Range. — Bed ten of Gaptank Formation.
Measurements. — (Mm).
Ht Lt C Holotype—B.V. 9.8 18.3 6.5 Paratype—L.V. 15.0 24.0 5.1
Paratype—L.V. 9.2 17.8 6.2
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 163
Material. — Holotype, U.S. National Museum, No. 155866. Paratypes, U. S. National Museum, Nos. 155867, 155868.
Discussion. — “Stutchburia” corrucostata is not closely similar to any known Carboniferous species. The species attains a moderate size and is ornamented with coarse costae at all observed stages of ontogeny. Though these ribs are coarse, they are not deeply im- pressed in the shell for slight corrosion produces a smooth valve. The ribs become progressively coarser posteriorly. The concentric lamellae are coarse all across the shell and bend ventrally at the junction with ribs to produce a fluted or nodose aspect.
Family ASTARTIDAE d’Orbigny Genus ASTARTELLA Hall, 1858
Diagnosis. — Shell essentially equivalve, subovate to subquad- rate, truncated posteriorly, ventral margin straight to broadly rounded; two cardinal teeth in each valve, two posterolateral teeth in left valve, one posterolateral in right valve; one anterolateral tooth in left valve, two anterolaterals in right valve; lunule and escutcheon well defined; ligament external, opisthodetic; adductor scars nearly equal; pallial line simple; ornament of concentric ridges of variable weight and spacing; beaks anterior, prosogyre; umbonal ridge usually low, broad, not well defined.
Type species.— Astartella vera Hall, 1858. Original designa- tion; monotypy.
Range. — Pennsylvanian-Permian.
Discussion. — Externally this widely distributed Late Paleozoic genus is sometimes difficult to distinguish from Cypricardella Hall, 1858 (Hall, 1858a). However, species of Cypricardella are re- ported to have but one cardinal tooth in each valve whereas in species of Astartella there are two cardinal teeth in each valve. Further, the umbonal ridge of Cypricardella is better defined and the valves are typically more elongate than in species of Astartella. (Compare also to Kaibabella Chronic, 1952 and to Eoastartella Ciriacks, 1962) .
Species of Astartella have been described primarily on the basis of ornamentation, position of beak, and nature of posterior margin. The latter two characteristics were not found to be useful for de- termining species. Ornamentation in Astarteila is of two main types;
164 BULLETIN 240
concentric ridges without lamellae between; A. varica McChesney, 1867, A. compacta Girty, 1915 (1915a), and A. subquadrata Girty, 1908 are examples; and concentric ridges with fine lamellae in in- terspaces, exemplified by dA. vera Hall, 1858 and probably 4. concentrica (Conrad), 1842. These small concentric lines between the ridges are developed to various intensities, being prominent in some specimens and barely visible with a hand lens in others.
Several proposed species are similar to Astartella vera Hall, 1858. Among these are: Astartella concentrica (Conrad), 1842; Edmondia concentrica McChesney, 1859 = Astartella concentrica (McChesney) , 1867; Astartella newberryt Meek, 1875; and Astar- tella gurleyi White, 1872. Of these, I have been able to obtain type material of only 4. vera Hall and A. gurley: White. Because of this lack of comparative material, actual synonymization is not made except in the case of A. vera and A. gurleyi.
In the course of the study of Astartella, topotypes of A. vera Hall were kindly loaned to me by Dr. J. M. Weller of the Walker Museum of the University of Chicago (now in Field Natural His- tory Museum). These specimens were compared to three other samples identified as A. vera and one sample of A. varica. In these comparisons only one of 28 possible combinations of characters tested proved valuable in species separation, to wit, height of beak versus length of valve. The results are shown in ‘Table 1.
From ‘Table | above it can be seen that, with the exception of the Wildhorse sample, each of the samples of Astartella vera is significantly different from A. varica for the regression of height of beak on length. The slope for this combination is so high for the “Coal Measures” sample that this sample showed significantly greater slope for the combination than the Heumader Shale and the Wewoka Formation samples of the same species. From this study it is seen that the regression of height of beak on length for species of Astartella is useful but not completely reliable for separ- ation of samples of the species. In the course of this study no better sets of characters were recognized, however.
The extreme variation of the combination height of beak and length of valve in the samples of A. vera suggests that height of beak alone is not sufficient for distinguishing closely related species of the genus. ‘The variation of this combination of characters shows
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 165
TABLE 1 Statistical Comparisons of Astartella spp. for the Regression of HB on Lt
Samples H We “C.M.” G.T. Wi 0 0 0 0 H 0 ty = We + ~
7 GaMes ~
Symbols: O—no significant difference at 5% level, one-sided. --—regression slope of column sample significantly greater than row sample at 5% level, one-sided. —-—regression slope of column sample significantly small- er than row sample at 5% level, one-sided. regression equations are given with species descrip- tions below. Wi— Wildhorse Formation, Wildhorse, Oklahoma; A. vera. H — Heumader Shale, Elk County, Kansas; A. vera. We — Wewoka Formation, Ada, Oklahoma; A. vera. “C.M.” — “Coal Measures”, Springfield, Illinois; A. vera. G.T.— Bed ten of Gaptank Formation; dA. varica.
neither vertical nor horizontal directional variation in the samples of A. vera studied. Further study may warrant the erection of sub- species for extreme variants of A. vera.
Species of Astartella are widely distributed in the Pennsyl- vanian. ‘They are found commonly in both near-shore and normal marine assemblages and do not seem to be valuable as tools for ecological interpretation.
Astartella vera Hall, 1858 Pl. 14, figs. 12-17 Astartella vera Hall, 1858, Rept. Geol. Sur. Iowa, vol. 1, pt. 2, p. 715, pl. 29, fig als:
A. gurleyi White, 1878, Acad. Nat. Sci. Philadelphia, Proc., p. 35.
Diagnosis. — Shell subtrigonal to subquadrate; anterior margin rounded to nearly straight; posterior margin nearly straight, meet- ing dorsal margin in distinctly obtuse angle; ventral margin nearly straight to broadly convex; dorsal margin gently arched; umbones prominent, gibbous; beaks relatively high in relation to length of valves; umbonal ridge broadly to rather sharply rounded; ornament
166 BULLETIN 240
of closely spaced concentric ridges and concentric lamellae of vari- able prominence in interspaces.
Range. — Pennsylvanian.
Measurements. — (See Appendix) .
Growth equations. — Essentially linear. Y = HB; X — [een the form Y = a, ++ b,,X. Computed by least squares.
“Coal Measures”, Springfield, Ill. Y — —0.16 + 0.460X Heumader Shale, Elk Co., Kansas Y — 0.03 + 0.266X Wildhorse Fm., Wildhorse, Okla. Ye) 0045-5075 exe Wewoka Fm., Ada, Okla. Y— 0.07 + 0.306%
Material. —‘Topotypes of Astartella vera Hall. Walker Mu- seum, University of Chicago, No. 13303, now in the Field Museum of Natural History. Hypotypes, Pennsylvanian collections of Drs. L. M. Cline and L. R. Laudon, University of Wisconsin.
Discussion. — The relation of this species to closely related or possibly synonymous species is discussed above. One species, A star- tella gurleyi White, is here placed in synonymy with A. vera. A small number of poorly preserved topotypes of A. gurleyi, along with topotypes of A. vera, were loaned to me by Dr. J. M. Weller. The two species occur together and A. gurleyt was apparently based on juveniles of A. vera.
Astartella compacta Girty, 1915 (1915a), another small form, is apparently distinct. Hoare (1961, p. 127) reported that fine lamellae do not occur in the interspaces of concentric ridges in Girty’s species.
Astartella vera was not collected from the Gaptank Formation, although dA. varica, with which it is sometimes associated, is com- mon in Bed ten of the formation.
Astartella varica McChesney, 1859 Pl. 14, figs. 9, 18, 19
Astartella varica McChesney, 1859, Chicago Acad. Sci. Ext. Trans.; McChesney, 1867, Chicago Acad. Sci., Trans., vol. 1, p. 42, pl. 2, fig. 21; Girty, 1915, U.S. Geol. Sur., Bull. 544, p. 145, pl. 18, fig. 1.
; Diagnosis. — Shell subquadrate, early stages subtrigonal; an- terior margin rounded to straight; posterior margin straight, meet- ing dorsal margin at oblique or nearly right angles; ventral margin nearly straight; dorsal margin essentially straight; umbones broad; beaks low with respect to length of valves; umbonal ridge indis- tinct; ornament of relatively widely spaced, sharp concentric ridges, no lamellae in interspaces.
‘TEXAS PENNSYLVANIAN PELECYPODS: BIRD 167
Range. — Pennsylvanian.
Measurements. — (See Appendix) .
Growth equations. — Essentially linear. y = HB; x = Lt; in the form Y — a, + b,,X. Computed by least squares.
Bed ten, Gaptank Formation Y — 0.13 + 0.135xX.
Material. — Hypotypes, U.S. National Museum, Nos. 155869, 155870.
Discussion. — Astartella varica is readily distinguished from other species of the genus by having coarser, more widely spaced concentric ridges without smaller lamellae in the interspaces. Judging from the description and illustrations of Cypricardella sec- toralis Girty, 1927 (1927a), this species may be conspecific with A. varica. The hinge of Girty’s species is not known, however, and it may prove to truly be a Cypricardella.
Excepting “Edmondia” subtruncata Meek, A. varica is the most common Bed ten pelecypod.
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APPENDIX Appended Tables of Raw Measurement Data (in millimeters).
Table I. See page 165.
TABLE II
Measurements of Specimens of Astartella varica McChesney, 1860 from Bed Ten, Gaptank Formation
Specimen Rt Lt LH HB Cc PC DAMB DPMB BV 1 10.3 10.4 8.9 3.4 8.0 37.9 6.0 11.5 BV 2 10.8 12.9 D2e7, 3.0 ey 40,2 6.1 8.5 BV 3 14.8 nts 15,1 4.6 10.4 6.8 11.7 BV 4 12.8 14.7 als}574 4.0 8.1 4,2 Doth 8.9 BV 5 12.2 14.5 13.2 LA 7.0 42,1 6.2 9.9 BV 6 11.8 13.9 11.9 3.2 9.1 41.1 6.0 7.9 BV 7 13.5 14.7 11,0 285 8.7 46.2 6.0 Ost BV 8 10.5 12.9 11.3 2.5 Wedd 36.4 4.6 8.2 BV 9 12.9 11.3 2.1 6.9 tone ee BV10 9.8 11.9 9.0 2.5 ew, 35.2 sae Date BV11 11.6 14.7 12.8 2.6 7.9 41.3 4.0 9.4 BV12 12.0 13.9 12.3 4.4 7.2 40.1 5.3 9.0 BV13 10.1 12.3 10.9 2.6 6.9 36.6 4.8 8.2 BVI, 10,1 11.9 9.9 Be3 Ufa 36.1 sleet iene BV15 7.2 9.1 7.9 2,2 5.4 26.9 4.2 5.5 BV16 13.0 4.1 13.0 3.3 8.7 42,2 5.8 10.0 BV17 13.0 14.9 12.0 3.4 7.9 45.9 6.0 12.0 BV18 13.0 14.5 13.8 B0/ 7.8 43.0 See) 9.9 BV19 11.9 13.4 12,2 3.5 74 40.2 Dae 8.4 BV20 12.0 15.8 14.0 3.3 9.8 45.0 5.4 10.9 BY21 4.2 15.8 15.9 5.0 10.5 48.0 ae pana BV22 13,2 18.0 15.8 2.6 8.0 52.0 5.3 11.9
Specimen Ht Lt LH HB c PC DAMB DPMB SR Velie Ve ces Wien ui SO gi SEA oe ne PURO na A Sen ue RS ie 2 Re eee BV 1 8.2 10,8 9.8 3.0, Boal 29.9 4.8 Woe) BV 2 8.2 9.3 9.0 2.6 atl Piles) 4.3 7.7 BV 3 8.0 10.8 8.8 3.6 Call 30.9 4.0 3 BV 4 Ore a2: 11.3 4.4 7.6 33.0 5.0 8.3 BV 5 8.7 11.0 10.0 Blow 6.8 30,5 4.6 TA BV 6 9.3 12.5 allo 353) 7.0 35.0 4.7 8.9 BV 7 8.0 52 8.9 3.0 5.0 AUS) 3.6 6.4 BV 8 10.2 12.0 alte) 3.4 ov) 34.7 4.8 eal BV 9 8.8 10.8 9.9 Sioa 5.8 29.8 4.8 8.0 BY10 9.6 12,0 10,2 355) 6.9 35.6 5.0 9.0 BV11 Qadl 10.9 10,0 BES 6.6 30.6 4.1 8.1 BV12 8.9 10,8 Det 7408) 5.4 31.6 4.0 ToS BV13 10,0 12.8 10.9 3.6 6.2 B5s2 Dal oak BV1A 7.0 8,0 ee 2.4 5.2 23.8 3.2 6.0 BV15 8.1 9.8 8.9 3.0 6.2 27.8 4.1 Goal BV16 le) 9.6 9.0 3.0 6.1 26.8 Boll 7.1 BV17 8.6 aD) 10,5 Saal 5.8 32.8 Sot 7.6 BY18 9) DaLeal 10.4 2.8 6.0 32.8 5.2 8.5 BV19 7.0 8.8 U9 2.5 5.4 24.6 3.4 6.4 BV20 8.8 10.6 9.0 Bod Dir) 29h) 4.0 7.0 TABLE IV Measurements of Astartella vera Hall, 1858 Wildhorse Limestone, Wildhorse, Oklahoma Specimen Ht Lt LH HB c PC DAMB DPMB BV 1 ee sD) 14.2 Wee alt gal Be)oal 7.0 11.4 BV 2 14.2 19,0 16.8 Yee alg) sal 53.4 Se) 13.9 BV 3 20.3 25.1 21.0 8.8 MESS 70.5 8.2 17.0 BV 4 is). 19.9 os 10.8 67.9 9.0 OBS BV 5 16.0 19.6 17.6 6.0 10.6 55.8 Mod) 13.0 BV 6 atfaee LON. 17.0 ae) 14.0 55.4 Tk 12.9 BV 7 12.9 16.0 14.3 5.6 10,0 44.9 6.6 11.8 BV 8 9.2 2a: 10.2 4.] 6.7 34.2 4.8 8.0 BV 9 16.2 18,8 18,8 6.0 8.6 57.8 Med) 17.0 BV10 16.5 19.8 NG at 6.0 10.9 51D 7.6 12.8
Measurements of Astartella vera Hall, 1858
BULLETIN 240
TABLE III
Heumader Shale, Elk County, Kansas
Birp
‘TEXAS PENNSYLVANIAN PELECYPODS:
TABLE V
, 1858
Wewoka Formation, Ada, Oklahoma
Measurements of Astartella vera Hall
DPMB
DAMB
C
Lt LH HB
Ht
Specimen
ANONOHOONMNOWN
SmMoOownrnwoer See!
ANWONOONOCO
Soeseererinls mes uitielaettionite sare
Onn wetaytsats
Onn RHOKRORNAN
COAMNHYOUD aad
NNONDWNOODNS
WMWINONUNUNAUNNAN AE
DoOorytwsOownoon
He owowwoon Hoar loa
ADANNORDDAHA
TOAKAOKOAS HAAN den
AHAOOMKHMODW MW
WOON aWKNWww doin
ANMDTNHOODWAO eS mmammmmammamaea
TABLE VI
, 1858
"Coal Measures", Springfield, Illinois
Measurements of Astartelle vera Hall
DPMB
DAMB
Lt
Ht
Specimen
HRonoowrooo
KAW wowww de
hOWWATANHO TOON unin
NOONNONWHAO
o 8 e
wOordnraore
FAWN ONO NATE et OF SIGN O MIAO
WOONDTOROON AXkwWAnmoHno Ss AnAnAnn eA
MOOWMOOANOS
HONWK ANS Sie sltesed ea tread
ROKHOAONANNY
OIE Sao gioeo
ANMNTNOHWAHAO bPb>b>b>>b>pept aaoamamanaaAa
176 BULLETIN 240
TABLE VII
Measurements of "Edmondia" subovata Meek and Worthen, 1869 from Bed Ten, Gaptank Formation
NNAHOBWO
ONDHHWYWOD
Specimen Ht Lt LH HB c PC DAMB BV 1 18,2 2207, 15.0 3.1 14.9 62.4 6. BV 2 Tgp. 24.9 20.7 5.8 16.7 66.6 5. BV 3 13.9 16.0 10.9 2.7 11.7 55.8 4. BV 4 19.3 23,1 17.9 4.3 16.0 66.8 5. BV 5 16,3 18,2 15.9 4.8 13.3 56.0 Be, BY 6 16.9 21.1 u4.9 5.3 14.9 66.0 5. BV 7 15.5 19.6 15.9 Pea. 18.4 55.3 ihe BV 8 12.8 16.0 11.0 2.8 10,3 45.8 a BV 9 4.2 17.0 13,3 4.7 13.2 50.6 i. BV10 19.8 21.5 18,2 4.1 15.1 62.8 6. BV11 16.7 18.0 15,3 4.0 13.5 56.0 5. BV12 18.7 21.9 16.8 4.8 13.7 60.3 5. BV13 16.0 18.9 15.9 3.2 10.7 56.5 5, BVA 16.9 20.9 16.4 3.8 Ww.4 57.6 4. BV15 14.0 17.0 13.6 3.6 11.5 49.2 5, BV16 16.4 18.6 14,2 4.0 13.4 54.8 he BV17 it ee mee) ie BV18 as ae iEee atist Gag BV19 16.0 19,2 17.9 S16Y/ 14.2 55.8 4. BV20 19.0 25.1 21.6 4.6 16.1 70.4 5. BV21 18.7 22,1 16.0 4.8 4.9 62.4 Be BV22 18.9 21.0 15.8 4.1 13.9 61.7 6. BV23 12,9 17.0 15,3 3.9 11.8 49.8 Ls BV24 eet 34.6 30.0 7,2 ei. a 9, BV25 17,2 23.3 19,8 4.2 17,0 6.2 ah
WNr OO MRO
:
YH Hee =)
=) OR ONUWWROONONOOR
=) HNONDBWANHMOOWNNN
al |
OR ARAMN
HH Qverd
nN ORRMON!HDA
PLATES
178 BULLETIN 240
EXPLANATION OF PLATE 11 Figure Page
12 PAE Amon dae SP yk oes secosee le eee ote oh eA be nce a eee eee 129 Bed ten, Gaptank Fm. USNM, loc. 700a; USNM, No. 155826. Left valve, hint of radial striae shows; X 0.8.
2-6. “Edmondia” cf. “E.” subtruncata Meek |... ee. 129
Bed ten, Gaptank Fm. 2. Right valve with broad umbone, faint ridge; X 1. 3. Cardinal view; X 1. 4. Subquadrate left valve; umbones sharp, ridge distinct; X 1. 5. Hinge line of left valve; edentulous; depression under beaks housed ligament, below this is transverse ridge. USNM, No. 155827; X 1.8. 6. Right valve of bi-valve specimen; ornament shows. USNM, No. 155828; X 2.2.
7-14. Pleurophorella costata (Meek and Worthen) 0... 0... 134
7a. Cardinal view showing two umbonal keels, lunule and escut- cheon, thin ligamental groove. Graham Fm., 4 mi. NE. of Jacksboro, Texas, coll. Renfros. USNM, No. 155830; X 1.3. b. Right valve; fine lamellae are between ridges; X 1.3. c. Left valve; X 1.3. d. Enlarged view showing triangular chondro- phore just below beaks; X 2.9. 8a. Right valve; ornament ex- tends dorsal to umbonal keel. Seaborne Ls., Fulton Co., IIl., coll. H. C. Wanless. Illinois Geol. Sur. Coll.; & 2.0. b. Cardinal view; X 2.0. 9. Right valve. Bed ten, Gaptank Fm.; USNM, loc. 700a; USNM, No. 155831; X 1.5. 10,11. Pyritized left valves; from the niggersheads over Rock Island Coal, Mercer Co., Ill., coll. H. C. Wanless, 1926; Illinois Geol. Sur. Coll.; X 2.0. 13,14. Types of Meek and Worthen’s species. Warren County, Ill. Illustrated specimens came from the same block of limestone, now disjointed. Illinois State Museum, No. 2975. Photographs courtesy Richard Leary, Illinois State Museum, Springfield. 13. Large right valve, probable holotype; slightly oblique view. Two smaller, fragmentary paratypes are below the holotype; X 1.3. 14. Two paratypic left valves; X 1.3.
15. “Stutchburia” corrucostata Bird, 1. SP. .......0o. ooo cceerrceeec eee 162 Bed ten, Gaptank Fm.; holotype, USNM, No. 155866. a. Cardinal view of young, bivalve specimen; posterior costae nodose; ligamental area covered by matrix; X 2.0. b. Left valve; costae increase in weight posteriorly; X 2.0. c. Right valve; X 2.0.
PLATE 11
BuLL. AMER. PALEONT., VOL. 54
BULL. AMER. PALEONT., VOL. 54 PLATE 12
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 179
EXPLANATION OF PLATE 12
Figure Page 1,2. “Stutchburia” corrucostata Bird, n. sp. 00. 162 Bed ten, Gaptank Fm.; paratypes. 1. Large left valve; USNM, No. 155867; X 1.5. 2a. Distorted lett valve of bivalve specimen; radial ornament worn; USNM, No. 155868; X 2.7. b. Cardinal view; hinge edentulous; ligamental area obscure; X 2.7.
3. Cypricardinia questa Bird, n. sp. Aer SRA EN ernie cl eG . 161 Bed ten, Gaptank Fm.; holotype, USNM, No. 155865. a. Frag- mentary lett valve of bivalve specimen; fine concentric lines between lamellae seen with hand lens : X 1.6. b. Cardinal view; X 1.6. 4,9. Grammatodon carbonaria (Cox) ... . 140
4a. Bivalve specimen; transverse ridge at hinge posterior not a tooth; Gaptank Fm., Marathon Dist., Monument Springs, Texas; coll. King and Girty, 1929; USNM, No. 155838; X 1.6. b. Right valve; rib size unequal; X 1.6. 5. Right valve; Bed ten, Gaptank Fm.; valve corroded; faint medial sulcus; USNM loc. 700a; USNM, No. 155839; X 1.4. 6. Left valve; Bed ten, Gaptank Fm.; USNM, No. 155840; X 2.0. 7. Elongate, pos- teriorly expanded right valve; USNM loc. 700a; USNM, No. 155841; X 1.4. 8. Right valve; Bed ten, Gaptank Fm.; USNM, No. 155842; X& 2.3. 9. Left valve. St. David Ls., Green Co., Ill.; Coll. J. M. Weller, 1928. Illinois Geol. Sur., No. 216; X 1.3.
10,11. Grammatodon biplicata Bird, n. sp. ooo... ee 142 Coll. Morningstar near Somerset, Perry Co., Ohio; lower Mercer Ls.; Pottsville Series; Orton Museum, No. 9188, Ohio State University. 10. Holotype; bivalve specimen; costellae coarsen posteriorly; some costae bifid, especially posterior; X 1.4. 11. Paratype; bivalve specimen; flattened costae; X 1.4.
12-14. Grammatodon erectumbona Bird, n. sp. oo... 138 12. Paratype; weathered right valve; ribs bifid, irregular in weight; USNM loc. 700a; USNM, No. 155834; X 1.6. 13. Para- type; left valve; USNM loc. 700; USNM, 155852; X& 1.9. 14a. Holotype; young left valve; ribs vaguely bifid at this growth stage; USNM loc. 700a; USNM No. 155833; X 2.6. b. Right valve; few ribs bifid; X 2.6.
15. Grammatodon cf. G. kansasensis (Sayre) ............................... 140 Bed ten, Gaptank Fm.; USNM loc. 700a; USNM, No. 155837. a. Long, low left valve; minute costellae near margins of valve; X 2.2. b. Cardinal view; X 2.2.
16. Wilkingia terminale (Hall) ............ LAH bap IB eee A veto RMN Let 00 131 Bed ten, Gaptank Fm.; USNM loc. 700; USNM, No. 155829; internal mold, right valve; X 1.1.
180
Figure 1,2.
10,11.
12.
13.
14,15.
16,17.
BULLETIN 240
EXPLANATION OF PLATE 13
Grammatodon hexacostata Bird, n. sp. ..... 00.02... ENN 139 Bed ten, Gaptank Fm.; USNM loc. 700a. 1a. Holotype; right valve; six ribs in medial sulcus; USNM, No. 155835; X 2.3. b. Cardinal view; X 2.3. 2a. Paratype; right valve; USNM, No. 155836; X 2.0. b. Hinge view, chevrons mark ligamental area; teeth tiny; X 2.0.
Conocardium parrashi Worthen 000.200... ee ees 144 Bed ten, Gaptank Fm.; USNM, No. 155843. Right valve; X 4.9.
Nuculopsis girtyi Schenck 2000... ete eects 137 USNM loc. 700a; USNM, No. 155832. Left valve; X 1.5.
Goniophora gnoma Bird, n. SP. .o........ occ eee ee teres 149 Bed ten, Gaptank Fm. Holotype; USNM, No. 155847. a. Hinge view; high convexity; two umbonal keels; prominent escut- cheon; X 2.5. b. Hinge view, incurved beaks; lunule; X 2.5. c. Oblique view of left valve; X 2.5.
Pteriaclongan(Geinutz) ci ie eae sinensis coe Neuen tense 145 Bed ten, Gaptank Fm.; USNM, No. 155844. Right valve; X 3.0.
Genus and species not determined 22.0.0... cece 146 Bed ten, Gaptank Fm.; USNM loc. 700a; USNM, No. 155845. a. Hinge view obscured by matrix; X 1.8. b. Left valve; X 1.8. c. Right valve with broad, vague costellae; X 1.8.
“Promytilus” postumbonus Bird, n. sp. ...0..00.0..... ee 146 Bed ten, Gaptank Fm.; USNM loc. 700a; holotype, USNM, No. 155846. a. Right valve with deep ventral sinus and _ sulcus; X 1.9. b. Left valve; X 1.9. c. Cardinal view; X 1.9.
Streblopteria (Streblochondria) semicosta Bird, i. sp. ............ 159 Bed ten, Gaptank Fm. Holotype; USNM, No, 155862. Right valve; costellae faint, widely spaced; X 2.6. Clavicosta cf. C. echinata Newell 2000. 152 Bed ten, Gaptank Fm. 10. Right valve with ribs of two weights; USNM, No. 155853; X 2.5. 11. Fragmentary right valve with fluted costae; USNM, No. 155854; X 2.0. Streblopteria (Streblopteria) obliqua Bird, n. sp. ........................ 155
USNM loc. 700a. Holotype; USNM, No. 155855. Right valve; X 1.6.
Streblopteria (Streblochondria) aff. S. (S.) sculptilus (Miller) 156 Bed ten, Gaptank Fm.; USNM, No. 155858. Right valve; X 2.4.
Annuliconcha interlineata (Meek and Worthen) .... ................... 151 Bed ten, Gaptank Fm. 14. Left valve; X& 2.0. 15. Right valve; USNM, No. 155851; X 3.0.
Acanthopecten carboniferus (Stevens)
Bed ten, Gaptank Fm. 16. Right valve; USNM, No. 155849; X 2.6.
17a. Umbonal area enlarged; X 30. 17b. Full view of same left valve; USNM , No. 155850; X 2.0.
BULL. AMER. PALEONT., VOL. 54
PLATE 13
Buu. AMER. PALEONT., VOL. 54 PLATE 14
Figure
1,2.
3-6.
7,8.
9,18,19.
10,11.
12-17.
TEXAS PENNSYLVANIAN PELECYPODS: BIRD 181
EXPLANATION OF PLATE 14 Page
Streblopteria (Streblopteria) Sp. 000 ees _ 155 1. Broken right valve; USNM loc. 700; USNM, No. 155856; X 1.4. 2. broken right valve; USNM loc. 700a; USNM, No. 155857; X 14.
Streblopteria (Streblochondria?) tenuilineata (Meek and Worthen) 158 3-5. Mercer Ls. S.E. of Frazeysburg, Muskingum Co., Ohio; coll. Morningstar, Orton Museum, No. 15289, Ohio State Uniy. 3. Opisthocline right valve; umbonal area eroded; X 2.1. 4. Ex- ternal replica of lett valve; X 2.1. 5. Worn right valve; auricles markedly low; X 2.1. 6. Bed ten, Gaptank Fm.; USNM, No. 155861. a. Umbonal area of right vaive enlarged to show cancellate ornament; X 30. b. Full view; ears typical height; X 2.4.
Streblopteria (Streblochondria) fila Bird, n. sp. ................... 157
Bed ten, Gaptank Fm. 7. Holotype; right valve; prominent fila and vague, fine radial ribbing; coarse crossed lamellar structure; USNM, No. 155859; X 3.3. 8. Paratype: right valve; USNM, No. 155860; X 2.0.
Astartella varica McChesney .oo....000000..cooccecceccceecetececeeeeeeeees 166 9. Gaptank Fm.; Texas Bureau Econ. Geol., Cat. No. 35393. Left valve; two prominent cardinal teeth; X 1.8. 18,19. Bed ten, Gaptank Fm.; USNM loc. 790. 18. Trigonal right valve; USNM, No. 155869; & 1.5. 19a. Left valve; USNM, No. 155870; X 1.5. b. Right valve; X 1.5.
Streblopteria (Obliquipecten) SP. .o..0..00000000oooococecccccecececceeees . 160
Bed ten, Gaptank Fm. 10. Broken left valve; part of anterior ear present; broad radial costae of anterior margin atypically prominent; USNM, No. 155363; X 1.6. 11. Larger right valve: anterior ear missing; USNM loc. 700; USNM, No. 155864; X 1.5.
Astartella;veravilalle iiss oe es soe alo aes 165
12,13. Topotypes from the Desmoinesian near Springfield, III. Walker Museum, No. 13303. Chicago Univ. (now Field Mus. Nat. Hist.) 12. Right valve; X 2.0. 13. Cardinal view; X 2.0. 14,15. Topotypes of 4A. gurleyi White: from the Desmoinesian near Danville, Ill. Walker Museum, No. 13320. Chicago Univ. (now Field Mus. Nat. Hist.) 14. Left valve: X 4.0. 15. Hinge view: X 4.0. 16,17. Heumader Shale (middle Missourian), Elk Co., Kansas, Univ. Wisconsin, 16. Cardinal view; X 2.0. 17. Left valve; lamellae seen with hand lens; X 2.0.
INDEX
Note: The left hand bold faced figures refer to the plates. The nght hand light figures refer to the pages.
A Acanthopecten .......... 121, 150 acutacarinata,
Goniophora ............ 149 Allorisma. .................... 126, 131, 132,
133, 135 angustata,
Sanguinolaria? ........ 126 augustata,
Sanguinolites .......... 135 annosus, Promytilus 146 Annuliconcha _............ 121, 151, 152 ANCOMS 3 ome oe 138 PAT Cae ierese means acti SAM 137 Arkell, W.-J. .............. 137 AStartellay es ee 120, 163, 164,
165, 166 Aviculopecten ............ 151, 156
B
Beede, J. W. ......0......... 112 Bellerophon _............ 120 Bellerophontids _........ 120 Bendian Series ............ 115 biplicata,
Grammatodon ....12 138, 142, 143 Black Peak, Texas .... 1174, 1018} Bostwick, D. A. .......... 112 Bowsher, A. L. ............ 120 Brachiopoda ................ 119 BransonynCa ee 137, 138 Brewster County,
ORAS ce aieshe ne 111
Cc Caballos Novaculite . 113 Canyon Series ............ 115 carbonaria,
Grammatodon ...12 121, 140, 141,
142, 143 carbonaria,
Parallodon .............. 143 carboniferus,
Acanthopecten 13 150, 152 carboniferus, Pecten 150 Cardiomorpha ............ 128 Cardium
(Conocardium) ........ 143 carinatum,
Conocardium ......... 144 Chaetetes Limestone 114
Chonetina association 117, 118 Chronicehe ye 150 Ciriacks, K. W. .......... 154 Cisco Series. ................ 115 Clavicosta. ...........5.. 121, 152, 153 @)ine 1a: Me es ee ee 166 “Coal Measures” ........ 164 compacta,
Astartella 00000000000... 164, 166 Composita .......0.0.0.0.0..... 119 concentrica,
Astartella ............... 164 concentrica,
Edmondia ................. 164 Condra, G.. Es 1... 114 Condrathyris .............. 119 Conocardium .............. 143, 144 Cooper, G. A. .............. 114 corrucostata,
“Stutchburia” 11,12 162, 163
costata, ‘“Allorisma” .. 126, 133, 135
costata, Orthonata? .... 162 costata,
Pleurophorella ....11 126, 133, 134,
135, 136 Cretaceous .................. 148 Grinoids#= ee 122 crista, Goniophora .... 149, 150 Crurithyris .................. 119 cullomensis,
triticites 2.0.0.0... 114 cymbaeformis,
Cypricardia ............ 149 Cypricardella ............ 163, 167 Cypricardia ................ 149 Cypricardinia .............. 120, 161, 162
D Del Norte Moun-
tains, Texas ............ 112 Denby alee eee pone 119 Desmoinesian
DELIESHe ee eae 113, 115 Devonian .................... 113, 161 Dickens, R. ................ 147, 148, 161,
162 Dimple Limestone ..”. 113 Doubtful Canyon,
AD Oa Si seer es. 112 Driscoll, E. G. ............ 136, 137 Dugout Creek,
POX AS) se een Me ee ene 112, 113, 114 Dunbar, C. O. ............ 114, 122
182
INDEX
E echinata, Clavicosta ............ 13 152 Edmondia ..................... 120, 125, 126,
127, 128, 129, 130, 164, 167
“RKdmondia” sp. ....11] 128, 129 elegantula,
Cypricardinia? ........ 161 AS Mie eae ne 127, 136, 137 elliptica, Venus ....... Ny. 126, 131 elongata,
Cardiomorpha ........ 128 elongatum, Cardium
(Conocardium) ........ 143 Enteletes ............0.0....... 119 EFoastartella 20.00.0000... 163 erectumbona,
Grammatodon ....12 138, 140, 143 Huphemitess 2... ... 120
fila, Streblopteria (Streblochondria) 14 154, 157, 158,
159 Fleming, J. 0... 125 Flint Ridge, Ohio ...... 159 foerstii, Crenipecten .. 159 Fort Stockton,
MORASS reas aione eee 114 Fulton County,
MNOS ee 117 Fusulines .................... 118, 122 G Gosseletina ................ ; 119, 120
Gastropod
associations...” 118, 119 Gastropoda ................. 119 Genus and species
not determined .13 146 Gintyre Gece oe 126, 127, 128,
133, 136 girtyi,
Nuculopsis ........ 13 136, 137 Glabrocingulum .......... 119 gnoma,
Goniophora ........ 13 149 Goniophora .................. 148, 149 Graham Formation .... 133, 136 Grammatodon ............ 121, 137, 138,
139, 140, 141, 142, 143
gurleyl, Astartella ................ 164, 166 H ET al lees ceteris tence 132 hawni,
Pseudomonotis ........ 152, 153 hemiplicatus,
Enteletes .................. 115 hertzeri,
Streblochondria 156, 157 Heumader Shale ....... 164 hexacostata,
Grammatodon ....13 139, 140 16 Gira be A Nis samme ace are Bona 126, 127, 128,
132, 135 hirundo,
My talus ee 145 Hoarse, R. D. .............. 166 Hopkins County,
Kentucky .............. 14] Hystriculina ................ 119 1 PMN OSes ee 141 inornata, Arca .......... 137
interlineata,
Annuliconcha ....13 151, 152 interlineatus,
Aviculopecten ........ 151 irregularis,
Driticites 2705202 114, 122
J Johnson, R. G. ............ 117, 118, 119, 122 johnsoni, Modiolus .... 148 K Kaibab Formation ... 149 Kaibabellaw 22 os. 163 Keal'S als wcsia a eee ean ta 118, 120 kansasensis,
Grammatodon ...12 140 KGa ea eee ee 112, 113, 114 Kein SRM Hainer ean oa 112 CITE oe linens wae: 127, 128, 131 Knightites
(Retispira) 2.0.0.0... 129 Koninck, L. G. de ...... 127, 128 koneckii, Modiolus .... 147 Kozlowskias tes ee 119
183
laevigata, © Meleagrina laevis, Obliquipecten lamellosa, Cypricardinia Loudon, L. R. ..............
Marathon Basin,
Texas Marathon, Texas Marvillas Chert Maryland maxima, Wilkingia .... Meek. HB ioc iccsneeses Meleagrina Mercer Limestone Mid-Continent Mississippian Missourian Series Monopteria Moore, R. C. ............... mooreli, Triticites Morningstar, H. .......... Morrowan Series Mourlonia Mudge, M. R. ........
Mytilus
Neospirifer newberryi, Astartella ob: Newell, N. D. Sela INTC OLED ee eee ee North Central MeCXa Spee se oe Nucula ......... Nuculopsis
1°)
obliqua, Streblopteria (Streblopteria) ...13 Obliquipecten
INDEX
161, 162
ial, 1H 112, 13 aia
119, 120 117, 118, 120, 122
145, 147
119
164 114, 133, 141, 148, 153, 159. 160, 162
138
. 115, 133, 136
136
- 120, 136, 137
155
. 154, 155, 160
Orbiculoidea
association .............. 117, 118, 119 Orbiculoidea.............. 119 Ordovicians 73. 113 Orthonota 2.0... 00000000... 134, 162 ovata, Edmondia ........ 130 Ozawkie cyclothem .... 120
P papillosa,
Pleurophorella ........ 126, 133, 135 Parallelodon .............. 121, 137, 139,
143 Ranker Cae Acci ee 120 parrashi,
Conocardium ...... 13 144 Pecos County,
ROM AS Pee Noni Meee 111, 112 PeCtenevies ce sees: 150 Pelecypoda .................. 120 RermMlany ee ee 118, 147, 154 Permophorus ............ . 133, 141, 162 Phanerotrema ............ 120 Pharkidonotus ............. 120 Phillhipssdg eee ee 127 Platyceras ee 120 Pleurophorella .......... 120, 125, 126,
133, 134, 135,
136
Pleurophorus ............. : 162
Pleurotomariids ........ 119, 120
Plummer, F. B. .......... 115 postumbonus,
“Promytilus” ...... 13 146, 147, 148 Pottsville Series ........ 159 pricei, Permophorus . 141 primaeva, Edmondia.. 126 Productidi ees 119 Promytilus 0.0.0.0... .. 146, 147, 148 “Promytilus” ............. 121, 146, 147,
148 Pseudomonotis 152, 153 Plena ee, ak cae 144, 145
Q
questa,
Cypricardinia ....12 161, 162
R Reticulatay ae 119 Rhynchopora ........... 119 RO GCI ee 121 ROSS Ca Airis 112, 115
184
INDEX
S St. David Limestone 141 Sanguinolaria? ............ 125, 126, 131 Sanguinolites .............. 125, 126, Ae Sayiresc Ana Nine ee 140, 145 Schenck, H. G. WW... 136, 137 Schopf, T. J. M. ........ 159 sculptilus, Aviculopecten ......... 156 sculptilus, Streblop- teria (Streblo- chondria) _............ 13 115, 156 sectoralis, Cypricardella .......... 167 semicosta, Streblop- teria (Streblo- chondria) a 13 154, 159 Somerset, Ohio .......... 143 Sphenotus ......0..000000.... 134 Spiniferid( 2 200... 119 splendens, Hystri- culinal Se ee 115 statonensis, Streblo- chondria .................. 156 Stockton Gap, Texas 112 Straparolus ................ 120 Strawn Series ............. 115 Streblechondria .......... 153, 156, 160 Streblopteria ............ 121, 154, 155 Streblopteria (Obliqui- pecten) sp. .......... 14 154, 160 Streblopteria (Streblochondria) .. 151, 154, 156, 157, 158, 159 Streblopteria (Streblopteria) ........ 154, 155 Streblopteria (Streblop- tenia) spe 14 155 Stutchburia —............ 120, 121, 162 subcuneata, Allor- ISMVAG Se mes eae 132 subcuneata, Walkingias yee 132 subquadrata, Astartella ................ 164 subtruncata, “Edmondia”’ ........ 11 128, 129, 130, 167 suleata, Edmondia ..... 131 suleata, Hiatella ...... 125, 131 suleata, Pteria ............ 145 suleata, Sanguino- Pana seins rani eaalees 125, 126, 131
T
tenuilineata, Streblop- teria (Streblo-
chondria)? .......... 14 154, 158, 159 tenuistriata, Parallelo-
GO TN AA ona ie 139 terminale,
Walkingia 2) 12 131, 132, 133 Trachydomia .............. 120 Trepospira .................. 120 Triticites ........0..0000..... 114, 122
U Wdden Jo Are soins. 112 unioniformis,
Edmondia ................. 127 unioniformis,
Isocardia ................. 125, 127 Upper Limestone
Series, Scotland .... 149
Vv varica, Astar- fellas ceo stain 14 164, 166, 167
ventricosa, Nucula .... 136
vera, Astartella ....14 163, 165, 166
Virgilian Series ........ 113, 115
Volsellina ....0000............ 147, 148 WwW
wabashensis,
Kozlowskia .............. 115 Wanless, H. C. ............ 135 Wianthiai, ea 120 Weller, J. M. .............. 135, 141, 164 welleri, Pteria ............ 145 Western Australia .... 147 Wewoka Formation . 164 Wildhorse
Formation (yen 164 Wilkingiae ie 120, 125, 126,
131, 132, 133,
134
Wilson, R. B. ............ 125, 126, 127,
128, 131
Worthen, A. H. ........ 130
Worthenia .................. 119, 120
Wyoming 2... 154 Y
Yochelson, E. L. ........ 117, 118, 120,
122, 148
185
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