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AP BULLETINS OF AMERICAN PALEONTOLOGY WAG, 2 * Wee S)42) Paleontological Research Institution Ithaca, New York i, Se AX CONTENTS, OF WW OLU ME XOCv Bulletin No. 88. 89. 90. Sil 92. 92A. 93. 94A. 94B. Middle Devonian Cstracoda from oil wells in south- western Ontario ByeMany Ch “Gurney a ee ee ee eee Eight species of Pennsylvanian crinoids By Jelewemallll Ib, Sierinjole ee Some echinoids from the Cretaceous of Texas By Willian Gikyole Wins; Some new crinoid species from the Morrow sub- series IBy Jeleserellll It, Sieben Four new crinoid species from the Wewoka forma- tion and two from the Ochelata group Byy leiesareill Ib, Siento Stellarocrinus, a new name for Whiteocrinus Strimple Iayy lelerereaulll Ib, iSietinnyol Devonian Bryozoa from Colombia TB ANgaebreengee 180, NYU GIN EN e New Mollusca from the Pleistocene of San Pedro, California-I By So Shellman Merry A stratigraphic study of the mollusks of the Calvert and Choptank formations of southern Maryland By Lois Margaret Schoonover __-—-----------..-.- INDEX Plates 11-16 17-18 Pages 1-382 33-48 49-88 89-98 99-108 109-112 113-146 147-164 165-298 > Ne i a hn ed “BULLETINS OF AMERICAN PALEONTOLOGY * VOL XV * NMUMBE RR Ss 19939 Irwaca, N. Y. LO Potts age se BULLETINS OF AMERICAN PALEONTOLOGY Volume 25 * Number 88 Middle Devonian Ostracoda from Oil Wells in Southwestern Ontario By Mary C. TuRNER August 12, 1939 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaea, New York Wo Ss Ag ty ‘ne wi WPOCOTAORIAT VADEREMA ies -_ =a -) pe sala = | ; BE Sadek T wratanwedio2 AL atteWRlG mort shoastfa0: Hsinoved slhbim =7 Pee a Gish. i TABLE OF CONTENTS THOMEPOGIT@ ROM oo cccconseroocceneneeceecenctacnd seédnooscceeec soc coc coSe ens ancposegsDEasonoaanaaaSccCOROHe Geologie and Stratigraphic Location of Fauna Historical Review 5 6 Preparation and Previous Study of Material _.....2.2-ee- 6 BESS eeaira 2) Vlg UTEP tay aN easel ese wees eee ale arc on eee en nese nereee 6 Comparison of Similar Faunas in Related Areas __..._........2.-.-.------ 7 Table I: Geeurrence of Species in the Various Fields 8 Table II: Occurrence of same Species in Related Areas 9 Description of New Species and Discussions on Previously Described FER TyTN Serer ee eee ee ruee cua MR UNE hein Se ek eT De eB DEANS... Seay 10 Siinirmmerd caravan 1G as © ONC UTS TONS ps as cree ers ne a nt ere eee 29 TRYSHECORECN SICK) a aee tp, RR Ca rere ESS 31 TBixgallammanier Ost VENOM a oe sccostenenecccneeeceseecacbeck coonon taocoasccaasonacenccanSaSnSeS 32 D jeamap eich sighs easy lah Seater es MIDDLE DEVONIAN OSTRACODA FROM OIL WELLS IN SOUTHWESTERN ONTARIO By Mary C. TuRNER INTRODUCTION GEOGRAPHIC AND STRATIGRAPHIC LOCATION OF FAUNA The presence of a microfauna in the Devonian strata of Ontario has been known since the early geological surveys were made, but, it has not been intensively studied until recent years. In 1935, a study of this microfauna, as represented in well cuttings from the oil and gas fields of southwestern Ontario, was initiated by the Geological Survey of Canada for the purpose of determin- ing its usefulness in the study of stratigraphy. Dr. M. A. Fritz (1), as the result of a preliminary study of these fossils, recently described seven microfossil zones in the Devonian strata encountered in the wells of the more important fields. The fields included were the Dover, Dawn, D’Clute, and East Tilbury, all of which are located in Kent and Lambton counties. With the aid of these zones, the horizon marker commonly used by drillers, the top of the Big Lime, was shown to be variable throughout the fields and, therefore, unreliable. At the same time a new horizon marker, the bottom of the Big Lime, was estab- lished. The fossil zones recognized are: Upper Spore zone; Up- per Ostracode zone; Pteropod zone; Bryozoa zone; Lower Spore zone; Trochiliscus zone; and Lower Ostracode zone. The Upper Ostracode zone is described as, “a particularly well marked horizon, extending throughout the bluish-gray calcareous shales of the Hamilton formation; these shales attain a thickness in certain wells of approximately 100 feet.” The ostracodes from this zone are herein discussed. This study was suggested as an M.A. thesis problem by Dr. Fritz whose helpful opinion and criticism throughout the prepara- tion of the thesis I wish to acknowledge. Ave 19 193: 6 BULLETIN 88 6 HISTORICAL REVIEW The ostracodes constitute one of the most important elements in the microfauna of the Middle Devonian of southwestern On- tario. These minute fossils were considered by a few of the early workers, but no exhaustive studies were made. As early as 1874, Nicholson (2), described the most typical spe- cies in this fauna, namely, Ponderodicyta punctulifera (Hall), from the Hamilton formation, Widder, Ontario. Later, Jones in 1890 (3), writing on Paleozoic ostracodes, described additional species from the Hamilton formation at Thedford and Arkona, Ontario. In 1915, Stauffer (4), recorded several typical species in his report on the Devonian of southwestern Ontario. The great abundance of the ostracode fauna in this area has been indicated only recently, in 1936, when Coryell and Malkin (5), described a large number of species from the Widder beds at Arkona, On- taro. PREPARATION AND PREVIOUS STUDY OF MATERIAL The ostracodes described and discussed in this paper form part of a collection of microfossils assembled by the Geological Survey of Canada, in connection with the previously mentioned study. The collection from the well samples was supplemented by specimens from surface exposures of the Hamilton formation at Thedford, Ontario. These were used for comparative purposes in this study. The material was loaned to the Department of Geology, at the University of Toronto, for further examination. The present research was carried on at the Royal Ontario Museum, Toronto. In a preliminary study of the ostracodes, Dr. Fritz determined the various types represented in the collections and made tentative generic identifications. This work, greatly facili- tated the present study. FAUNAL SUMMARY The majority of the ostracodes in the collection are typical Devonian forms. Thirty-one species have been identified. Nine new species and two new varieties of hitherto known species have been described. One new genus, Boursella, a minute, well marked form, not uncommon in the well cuttings, has been erect- 7 DEVONIAN OSTRACODA: TURNER 7 ed. The identified species are :— Haploprimitia punctata, n. sp. Ulrichia conradi Jones Ulrichia fragilis Warthin, var. subnodata, n. var. Boursella trilobata, n. sp. Halliella bellipuncta (VanPelt) Tetradella cicatricosa Warthin Hollinella granifera (Ulrich) Hollinella subcircularis, n. sp. Hollinella, sp. Dizyogopleura euglyphea Warthin Dizygopleura trisinuata VanPelt Dizygopleura sculptura, n. sp. Poloniella cingulata Warthin Eukloedinella doverensis, n. sp. Amphissites subquadratus (Ulrich) Amphissites parallela (Ulrich) Octonaria quadricostata VanPelt Octonaria. ef. crescentiformis VanPelt Euglyphella sigmoidalis (Jones) Bufina lineata, n. sp. Lueasella mundula Stewart Menoeidina subreniformis Stewart Menoeidina arcuata, n. sp. Ponderodictya punctulifera (Hall) Ponderodictya ohioensis (Stewart) Quasillites obliquus Coryell and Malkin Quasillites reticulata, n. sp. Quasillites fordei Coryell and Malkin, var. minimus, n. var. Spinovina distributa Coryell and Malkin Jenningsina concentrica, n. sp. Entomis, sp. The relative abundance of the different genera and species varies greatly. Two genera in particular, Ponderodictya and Quasillites, occur in great numbers and varieties of form through- out all the wells in the four fields considered. In other instances, only one or two specimens of a particular species have been found, as in the case of Eukloedinella doverensis, n. sp., and Halliella bellipuncta (VanPelt), each being represented by a single speci- men. Table I shows the occurrence of the ostracodes in the wells, grouped in their respective fields. COMPARISON OF SIMILAR FAUNAS IN RELATED AREAS A similar assemblage of Middle Devonian ostracodes has been described in recent years from the Bell shale, Michigan (6), from the Traverse group, Michigan (7), from the Silica shale, Ohio (8), and the Widder beds at Arkona, Ontario (5). Table II gives the occurrence of the species listed above in these related areas. It will be noted that this area has more species in common with the areas in Michigan and Ohio than the Widder beds, Arkona. 8 BULLETIN 88 TABLE I: Occurrence of Cpecias in the Various Fields ole H a ci] | al, 22 (sa) isa} Species rv) Q | @ >| Plo q a] ale te) a & (e) oO}; @ ®@ oO Boil Sad a} p 42 a av S|) | 3 a §|~ | al] ala Xe) Sle (e) d}| Oo] ofo j > (op) re) ia) o e io Bi ad alo a1 NX} o yy) A) 2) Q A | ct | e SS) Slo] Bie) 2 ae 3 e) ° Niel si) el) ©] Se cas 57) oA 3) ~P {e} Ol] a wrth a bY a a qi ag) ao} Oo] <= a] a} a aja ; fal (=) A}!A Sean ae atte o> | Amphissites | Amphissites subauadrata (Ulrich) | Boursella trilobata, n. gen., Be || 32 Re | gaG x Qe Sp. Bufina lineata, n. sp. 4 | Dizygopleura trisinuata Van Pelt Dizygopleura sculpture, n. spo |Entomis, sp. | Euglyphella sigmoidalis (Jones) | Eukloedinella doverensis, n. sp. |} Halliella bellipuncta Van Pelt | Haploprimitia punctata, n. sp. |Hollinella granifera (Ulrich) | Hollinella subcircularis, n. sp. )Hollinella, sp. | Jenningsina concentrica, n. sp. i Lucasella mundula Stewart | Menoeidina arcuata, no spo | Menoeidina subreniformis Stewart ‘ Octonaria ef. crescentiformis | Warn Pelt | Octonaria quadricostata Van Pelt Polonielia cinguleta Warthin i Ponderodictya punctulifera (Hall) Quasillites fordei, var. minimus | The Varo Quasillites obliquus Coryell and Malkin Quasillites reticulata, no ap. Gal 4 x AR RR AR tal K x x | Spinovina distributa Coryell and x Malkin | Tetradella cicatricosa Warthin | Ulrichia conradi Jones x x Ulrichia fragilis var. subnodeta Ne var. cat hore: Uszion €7 9 DEVONIAN OSTRACODA: TURNER TABSIE II: Occurrence of same Species in Related Areas | Silica | Beli Shale Species from Ontario Oil Wells Amphissites parallela (Ulrich) Amphissites subquadrata (Ulrich) Boursella trilobata, n. gen., | ne spe. Bufina lineata, n. sp. Dizygopleura euglyphea Warthin Dizygopleura trisinuata Van Pelt Dizygopleura sculpture, n. spo Entomis, sp. Euglypnella sigmoidalis Jones | Eukloedinella doverensis, n. sp. Halliella bellipuncta (Van Pelt) Haploprimitia punctata, n. sp. Hollineila granifera (Ulrich) © Hollinella subcircularis, n. sp. Hollinella, sp. Jenningsina concentrica, n. sp. | Lucasella mundula Stewart Menoeidina arcuata, ne sp. Menoeidina subreniformis Stewart Octonaria cr. crescentiformis Van Pelt Octonaria quadricostata Van Pelt | Polonielia cingulata Warthin | Ponderodictya punctulifera (Hall) Ponderodictya ohf{oensis (Stewart) Quasillites fordei, var. minimus, nD. var. Quasillites reticulata, n. sp. Quasillites obiiquus Coryell and Malkin [| Spinovina distributa Coryell cand Malkin | Tetradella cicatricosa Warthia Ulrichia conradi Jones Ulrichia fragilis, var. subnodata, ne Vare Traverse Group Michigan Widder Beds | Ontario 10 BULLETIN 88 10 The ostracodes herein considered are the first in this facies to be described from below the surface; the collections in the related areas were made from surface exposures. DESCRIPTION OF NEW SPECIES AND DISCUSSIONS ON PREVIOUSEY DESCRIBED FORME Superfamily BEYRICHIACEA Family PRIMITIIDZ Ulrich and Bassler Genus HAPLOPRIMITIA Ulrich and Bassler, 1923 (Maryland Geol. Surv., Silurian, 1923. p. 297) Haploprimitia punctata, n. sp. Plate 1, fig. 1 The carapace is minute, tumid; the outline is suboval. The ratio of length to height is 1.5 to 1. The valves are convex with the greatest convexity in the posterior half. The dorsal margin is straight, equal to three-quarters of the length of the carapace; a shallow channel in the posterior two-thirds indicates the hinge. The cardinal angles are obtuse, the posterior is the more acute, approaching 90° in some specimens. The posterior margin is broadly and evenly rounded, the anterior margin is narrowly rounded. The ventral margin is convex, rising to the anterior. The surface of the valves rises abruptly from the posterior margin, the slope is steeply concave and inclined towards the anterior, leaving a narrow flattened rim around that margin. The slope to the other margins is rounded. The greatest length of an average specimen, measured midway between the dorsal and ventral margins is 0.45 mm., the greatest height measured in the posterior half is 0.29 mm., the greatest thickness measured in the posterior half is 0.25 mm. Anterior to the centre of each valve a well defined sulcus ex- tends from below the dorsal margin halfway to the ventral margin. il DEVONIAN OSTRACODA: TURNER 11 The ventral extremity of the sulcus is umbilicate. The surface of well preserved specimens is distinctly but not profusely punctate. Remarks.—Haploprimitia simplex Stewart is a related form. In H. punctata the ventral margin rises more definitely towards the anterior; the sulcus is broad and well defined and terminates directly below the dorsal margin, whereas in H. simplex the sulcus is a linear slit. The punctate surface serves as a further distinc- tion between the two species. Holotype. Collections of Geological Survey of Canada, Ot- tawa, No. 9395. Genus ULRICHIA Jones, 1890 (Quart. Jour. Geol. Soc. London, vol. 46, 1890, p. 543) Ulrichia fragilis Warthin, var. subnodata, n, var. Plate 1, fig. 2 Ulrichia fragilis Warthin, 1934, Mus. Pal. Univ. Mich., Contr., 4, No. 12, JO. Bal, oll, Il, wkeg. dil, Warthin’s description of Ulrichia fragilis is as follows :— Carapace semiovate in lateral view, with pronounced backward swing; greatest height just posterior to the center; anterior end much sharper and higher than the posterior; hinge line straight, four-fifths of the total length; false border around the free margins delineated by a thin carina which is strongest ventrally; the carina describes a nearly perfect semi- circle, cutting across the anterior portion about one sixth of the length from the end; tubercles blunt, short, converging towards the dorsal margin, where they barely project above the hinge line; kirkbyan pit twice the size of the reticulation pits, located on the antero-ventral slope of the posterior tubercle; surface of the valves within the false border finely reticulated. Length, 0.53 mm., beight, 0.53 mm. The description of Ulrichia fragilis, var. subnodata, n. var., follows :— ; The carapace is subquadrate in laterial view. The valves are flat, with a slight convexity in the posterior half. The ratio of length to height is more than 2 to I. The dorsal margin is straight, equal to four-fifths of the entire length of the carapace. The cardinal angles are obtuse, the anterior is the more acute. The posterior margin is rounded, more protuberant immediately below the mid-line. The anterior margin is straight in the dorsal half, rounded, and more protub- erant in the ventral half. The ventral margin is convex, rising towards the anterior. The greatest length measured slightly below the mid-line is 12 BULLETIN 88 12 05 mm., the greatest height measured in the posterior half is 0.27 mm. There is a marked difference in height between the posterior and anterior extremities. A high, narrow ridge parallels the posterior and ventral mar- gins but anteriorly it rises abruptly to the dorsal margin, leaving a wider marginal border in the antero-ventral region. There are two, low, blunt nodes situated in the dorsal posterior two-thirds of each valve. The sulcus between them is shallow. The anterior node extends to the dorsal margin, the posterior is smaller and does not reach the dorsal margin. The surface within the bordering ridge is coarsely pitted. Remarks.—Three specimens of this species were available for study. As compared with Warthin’s species, their outline is much more angular; the narrow ridge or carina which defines the false border is subsemicircular rather than semicircular, and the nodes are unequal and much lower. ‘Specimens of the typical U. fragilis were found in the surface collections from Thedford, Ontario and used for purposes of com- parison. The specimens placed in U. fragilis subnodata are quite distinct from U. fragilis but the differences are not considered to be sufficient to separate them entirely from that species. Holotype.—Collections of Geological Survey of Canada Ot- tawa, No. 9396. Genus HALLIELLA Ulrich, 1891 (Cincinnati Soc. Nat. His., Jour., 18, pt. 2, 1891, p. 184) Halliella bellipuncta (VanPelt) Plate 1, fig. 3 Amphissites bellipunctus VanPelt, 1933, Jour. Pal., vol. 7, No. 3, p. 332, pl. 39, figs. 37-40. Halliella bellipuncta Warthin, 1934, Mus. Pal. Univ. Mick., Contr., vol. 4 WO, WA, jo, BOS, ol, Il. sole, B, A single valve represents Halliella bellipuncta in this collection. It agrees remarkably well in every detail with the description of the type species given by VanPelt. This species resembles very closely Kirkbyella typa, a Penn- sylvanian form described by Coryell and Booth (9), from the Wayland shale, Texas, and for which the genus Kirkbyella was erected. A Devonian species K. wnicornis Coryell and Malkin (10), has also been described. This latter species bears some re- semblance to H. bellipuncta. Each of these three species has the 13 DEVONIAN OstTRACODA: TURNER 13 typical umbilicate sulcus extending from the dorsal margin half- way to the ventral margin, the raised ridge terminating in a blunt 20de in the ventral half of each valve, and the strongly reticulated surface. The generic description of Kirkbyella mentions the un- ornamented marginal rim or ridge found, also, in H. bellipuncta. Hf. bellipuncta has been described from the Silica shale (11), Ohio ; the figure given is strikingly similar to that given by Coryell and Booth for K. typa. The three species, K. typa, K. unicornis and H. bellipuncta appear to be congeneric. If such is the case, the genus Halliella would be adequate for the reception of all of these species. These observations are based entirely on comparison of the descriptions and figures of the various species and specimens in this collection. Several complete specimens from the surface collections were also used. With regard to the orientation of Halliella bellipuncta Warthin, in placing H. bellipuncta in the genus Halliella, followed the orig- inal orientation as given by Ulrich, that is, he considered the sul- cus to be posterior to the centre. VanPelt considered the sulcus to be anterior to the centre, which results in an opposite orientation. In the opinion of the writer, there is no distinctive character in the general shape of the carapace that warrants the correct orien- tation. Family BEYRICHIID2 Jones Genus BOURSELLA, n. gen. The carapace is minute, subsemicircular to subquadrate in lateral outline. The valves are convex. The thickness of the valves increases rapidly from ventral to dorsal margin, giving a wedge-shaped appearance in ventral view. The dorsal margin is straight, the valves are distinctly trilobate dorsally, the lobes being confluent ventrally with the general surface of the valves. The median lobe is the largest and projects obliquely beyond the dorsal margin. The nodes or lobes are separated by well defined sulci. The valves are subequal, the presence of a narrow overlap of 14 BULLETIN 88 14 the right valve on the left along the free margins is doubtful. The surface is granular. The following species, B. trilobata, n. sp., becomes the geno- type for this newly erected genus. ' Boursella trilobata, n. sp. Plate 1, fig, 4 The carapace is minute and subsemicircular to subquadrate in lateral outline. The valves are convex, increasing in convexity in the dorsal half. The ratio of length to height is slightly more than 2 to I. The dorsal margin is straight, equal in length to three-fifths of the greatest length of the carapace. The cardinal angles are subequally obtuse. The posterior margin is broadly and evenly rounded, the anterior more narrowly rounded. The ventral margin is convex, rising towards the anterior. The maximum length of an average specimen measured mid- way between dorsal and ventral margins, is 0.4 mm.; the height measured in the posterior half is 0.25 mm.; the ‘hicknese increases from ventral to dorsal margin, where it measures 0.11 mm. The right valve appears to be very slightly larger than the left in some specimens, in which the right valve curves over the left on the free margins. The presence of a true overlap is doubtful. The hinge occupies the whole length of the dorsal margin. Each valve is distinctly trilobate in the dorsal half. Ventrally the lobes are confluent with the general surface of the valve. The median lobe is the largest, and forms a spinelike projection be- yond the dorsal margin. It curves obliquely towards the poster- ior. The posterior lobe projects slightly beyond the dorsal mar- gin, and is partially divided again by a very shallow sulcus. The anterior lobe does not extend to the dorsal margin, but is quite distinct and is also inclined towards the posterior. The posterior sulcus is broad and extends from the dorsal margin halfway to the ventral. It maintains a uniform width and has a squarish ventral termination with a slight curve poste- riorly in certain specimens. The median sulcus is narrower and more elongate than the posterior. It extends two-thirds of the distance to the ventral margin. Ventrally, it becomes a shallow depression which curves posteriorly. This sulcus defines the median lobe anteriorly and gives the effect of obscurely yoking it with the posterior lobe, thus setting the posterior and median 15 DEVONIAN OstTRACODA: TURNER 15 lobes apart from the anterior lobe. The surface of the valves is quite distinctly granulose. Remarks.—The strong, spinelike, median dorsal lobe in this new genus immediately suggests an Aechminidlike ostracode. The two smaller lobes, however, separated from the larger one by definite sulci, gives a trilobate effect. The presence of the three lobes has been a determining factor in placing this genus in the family Beyrichiide. A number of specimens were sent to Dr. F. M. Swartz*, who also noted the Aechminid resemblance ; furthermore, he suggested that the obscure yoking of the poste- rior and median lobes might indicate affinities with the genus Bollia. Additional species in future studies may show more definitely the relationships of the genus. A Pennsylvanian genus Aechminella Harlton (12), is closest to this form. Though it is much larger than this species, three dorsal spines or nodes are present. - Aechminella, also, has an Aechminid appearance as would be indicated by the name. It is classified in the family Beyrichtide. Boursella trilobata is a distinct little form which will not be confused with any of the typical Devonian ostracodes. The small size is a constant feature and diagnostic in itself. The species is not uncommon in the well cuttings. Genoholotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9397. Genus HOLLINELLA. Coryell, 1928 (Emen. Kellett, 1929) (Coryell, Jour. Pal., vol. 2, No. 4, 1928, p. 377-378 Kellett, Jour. Pal., vol. 3, No. 2, 1929, p. 196-200) Hollinella granifera (Ulrich) : Plate 1, fig. 19 Bollia granifera Ulrich, 1891, Cincinnati Soc. Nat. Hist., Jour., 13, p. 205, pl. 12, figs. 12a, 12b. Hollina granifera Ulrich and Bassler, 1908, U. S. Nat. Mus., Pr., 35, p. 315, pl. 42, figs. 16, 17. Hollinella granifera Bassler and Kellett, 1934, Bibliographic Index of Pal., Ostracoda, p. 332. An emended description of the species is given. The carapace is elongate, ovate, tapering towards the anterior * Pennsylvanian State College. 16 BULLETIN 88 16 end. The ratio of greatest length to greatest height, including the irl WS We 1H Th The dorsal margin is straight, the length slightly less than that of the carapace. The cardinal angles are subequally obtuse. The anterior margin is straight in the dorsal half, with a pronounced ventral backward swing. The posterior margin is straight in the dorsal two-thirds, rounding ventrally into the very convex ventral margin. The maximum length measured ventral to the mid-line is 1.3 mm.; the height measured in the posterior half is 0.85 mm., including the frill. The height decreases rapidly in the anterior half of the carapace. The thickness is 0.55 mm. measured slight- ly anterior to the centre. The articulation of the free margins and the hinge appear to be characteristic of the genus, that is, the left valve fits into a groove in the free margins of the right valve; along the hinge, the left valve receives the right, except at the cardinal extremities, where the right valve overlaps the left. The frill extends from a short distance below and in front of the posterior dorsal angle, parallels the posterior and ventral margins and terminates at a point below the anterior extremity of the anterior dorsal node. The surface is marked with a deeply impressed sulcus, situated posterior to the centre, and extending from the dorsal margin to below the mid-line. From this point it becomes a posteriorly di- rected, shallow depression, extending almost to the frill. Ante- riorly the sulcus is bounded by a prominent hemispherical node which rises well above the surface. It projects beyond the dorsal margin and is separated from the low swelling ventral to it by a sharp sulcus. A small lobe is situated on the lower part of the posterior margin of the sulcus. Ventrally this lobe is confluent with the general surface of the valve. The surface of the valves anterior to the prominent anterior node is gently convex, the surface at the posterior extremity is flat and continuous with the frill. The entire surface is coarsely granular. Remarks.—A single specimen of this species was found. The genus Hollinella is not of common occurrence in the Devonian 17 DEVONIAN OSTRACODA: TURNER 17 faunas, and has not been recorded from any of the related areas considered in this study. This specimen differs in several minor aspects from the type species; the frill is more extensive postdorsally and is not as wide, and the anterior node does not appear to be quite as prom- inent. H. granifera, however, seems to be the appropriate species in which to place this specimen. Hollinella. subcireularis, n, sp. Plate 1, fig. 20 The carapace is elongate, rectangular in outline. The ratio of the greatest length to greatest height is 1 to 2. The dorsal margin is straight, almost equal to the entire length of the carapace. The anterior cardinal angle is acute, approxi- mately 90°; the posterior cardinal angle is slightly obtuse. The anterior margin is vertical in the dorsal two-thirds, curving strongly into the convex ventral margin. The posterior margin is broadly and evenly rounded. The greatest length of the carapace measured midway between the dorsal and ventral margins, is 1.2 mm., the height, including the frill, is 0.65 mm., in the middle of the posterior half. There is a slight decrease in height anteriorly. The valves are moder- ately convex. The greatest thickness is in the ventral half, slight- ly posterior to the centre. The right valve is larger than the left, the margin being apparently grooved for the reception of the smaller valve on the free margins. This contact margin is finely denticulate. At the cardinal angles, the right valve overlaps the left valve. The marginal frill extends from the postdorsal margin, parallel to the posterior and ventral margins, rising towards the anterior, where it terminates one-sixth of the length of the valve from the anterior margin. The frill is finely crenulated. A deep median sulcus extends from the dorsal margin to below the mid-line. At its ventral extremity, the sulcus expands ante- riorly and posteriorly, forming an inverted T-shaped depression. The surface of the valves rises in a U-shaped ridge above the sulcus. The ridge terminates anteriorly in a large bulbous node which extends to the dorsal margin. It is separated ventrally from the ridge by a narrow depression. The ridge terminates posteriorly in a small, elongate node, situated well below the 18 BULLETIN 88 18 dorsal margin. This node is also separated from the ridge by a shallow depression. The ridge rises steeply from the frill. The surface at the anterior extremity of the valves is flat and low. The entire surface, including frill and sulcus, is finely granu- lose. Along the posterior quarter of the dorsal margin, four distinct spines project beyond the edge of each valve. A number of similar spines are situated in a corresponding anterior position, and occur sparsely over the general surface. This frilled specimen is a female of the species. A small speci- men without a frill and with a similar shape and arrangement of lobes and sulci, is also placed in this species. It is regarded as a young specimen. The length of this specimen is 0.87 mm., the height is 0.43 mm. The surface is very finely granulose and bears no spines. Remarks.—The identification of this species is based on the two specimens described, but the shape and extent of the sulcus, the subsemicircular shape of the carapace, the distinct ventral slope of the U-shaped ridge, and the spines along the dorsal margin, dis- tinguish it from any of the described Devonian species. Hollinella subcircularis bears a closer resemblance to certain Pennsylvanian and Permian species than to any of the earlier Palaeozoic forms. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9308. Hollinella, sp. Plate 1, fig. 17 A single specimen with the characteristic features of Hollinella is placed in this genus. Two features distinguish it from the other specimens in this collection, namely, the abrupt linearlike depres- sion of the sulcus and the presence of two spines on each valve in anterior and posterior ventral positions on a line along which a frill would arise. These spines or nodes are thought to be an incipient frill, in which case, the specimen would be a young female. Although several additional specimens were found in the sur- face collections which showed the above-mentioned features the relationships of the form are not sufficiently clear to warrant a specific identification. Additional material, includ- ing the frilled variety, would be necessary in order to determine the species. 19 DEVONIAN OSTRACODA: TURNER 19 Family KLOEDINELLIDZE Ulrich and Bassler Genus DIZYGOPLEURA Ulrich and Bassler (Maryland Geol. Surv., Silurian, 1923, p, 213) Dizygopleura sculptura, n. sp. Plate 1, fig. 6 The carapace is ovate, subquadrate in lateral outline. The valves are convex, the convexity increasing towards the anterior. The dorsal margin is irregular, rising towards the posterior, where the right valve extends over the left as a narrow flap. The posterior margin is broad and rounded, somewhat more extended dorsally. The anterior margin is truncate, almost straight. The ventral margin is shghtly concave at the middle, rising anteriorly. The greatest length, slightly dorsal to the mid-height in an average specimen, measures 0.5 mm.; the greatest height, meas- ured at the posterior end of the hinge flap, is 0.3 mm. The right valve is the larger, overlapping the left on the free margins and at the posterior end of the dorsal margin. The surface of each valve is highly sculptured. The posterior sulcus extends from below the hinge flap almost to the ventral margin, curving forward and tapering to a point. The median sulcus is wider than the posterior and continues from a short distance below the dorsal margin to below the mid-line. Ventral- ly it curves backward. The anterior ‘sulcus begins farther below the dorsal margin than the median sulcus, curves anteriorly parallel to the anterior margin, then curves ventrally and poste- riorly, almost meeting the posterior sulcus in some specimens. The four lobes or ridges formed by the sulci are united ventral- ly, the two anterior ones unite dorsally, enclosing the dorsal end of the anterior sulcus, and forming a ridge which slopes steeply to the dorsal margin. The slope from the ridge to the anterior margin is concave. There is a tendency, also, for the two poste- rior lobes to be raised dorsally above the general surface. The slope from the posterior lobe to the margin is rounded and less abrupt than the corresponding anterior slope. ; Remarks.—This species most closely resembles D. minima Ulrich and Bassler (13), a Silurian species in which the anterior lobes are confluent dorsally. These Devonian specimens are 20 BULLETIN 88 20 larger than D. minima and differ, also, in that the posterior and anterior sulci curve towards each other ventrally, and in some specimens almost unite. All the surface features appear to be more highly developed and more clearly defined in this newly described species. It may be distinguished from other Devonian species by its shape, and by the arrangement of the anterior lobes and sulcus. Holotype-—Collections of the Geological Survey of Canada, Ottawa, No. 9399. Genus EUKLOEDENELLA Ulrich and Bassler (Maryland Geol. Surv., Silurian, 1923, p. 313) Eukloedenella doverensis, n. sp. Plate 1, figs. 5, 8 Eukloedenella, sp., Stewart, 1936, Jour. Pal., vol. 10, No. 8, p. 750, pl. 100, fig. 28. The carapace is comparatively large, with a smooth surface and subquadrate outline. The valves are convex, somewhat flattened posteriorly, and thickened anteriorly. The dorsal margin is straight, channelled in the anterior half for the hinge. The cardinal extremities are obtuse, the posterior cardinal slope being longer and more obtuse than the anterior. The posterior margin is broadly rounded ventrally. The ante- rior margin is blunt with a backward swing. The ventral margin is straight, rising slightly to the posterior. The greatest length measured at mid-height is 0.9 mm., the greatest height is in the anterior half and equal to 0.49 mm., the thickness, also, in the anterior half is 0.3 mm. A simple umbilicate sulcus on each valve posterior to the centre extends from the dorsal margin slightly less than halfway to the ventral margins. The left valve appears to be larger than the right, but the valves are not in contact along the free margins, and the relative size cannot be definitely determined. Remarks.—A single complete and well preserved specimen of this species was found. Stewart recorded and figured an incom- plete specimen from the Silica shale, Ohio, which appears to be the same as this specimen. The specimens most closely resemble the Silurian species E. wmbilicata Ulrich and Bassler, which is the typical species in Group II of the genus Eukloedenella as out- lined by them, and to which Stewart referred her specimen. E. richmondensis Spivey (14), recently described from a single specimen in the Maquoketa shale, lowa (Ordovician), resembles 21 DEVONIAN OstTRACODA: TURNER 21 this Devonian species in ‘general outline, but, it is thicker poste- riorly, whereas E. doverensis thickens anteriorly, and is a larger and more robust form. ‘The sulcus is closer to the posterior mar- gin in E. richmondensis. Holotype.—Collections of Geological Survey of Canada, Otta- wa, No, 9400. Superfamily CYPRIDACEA Family THLIPSURIDA Jones Genus BUFINA Coryell, 1936 (Am. Mus. Nov., No. 891, Nov., 1936, p. 8) Bufina lineata, n. sp. Plate 1, figs. 9, 12 The carapace is elongate, the outline is subrectangular. The valves are tumid, thick,and flattened laterally. The dorsal margin is straight, rising towards the anterior and posterior; the intervening length is depressed. The cardinal angles are obtuse, the anterior being the more acute. The posterior margin is rounded and more extended ventrally. Some specimens have small spinelike papille on the posterior-ventral border. The anterior margin is truncate, almost straight, swinging back into the ventral margin. The latter is slightly convex, rising towards the anterior. The maximum length of the carapace is 0.81 mm., the height 0.34 mm., the thickness 0.28 mm. The valves are equal. The surface of the valves is raised high above the contact margin, leaving a narrow flat border. Two prominent blunt spines, project obliquely forward from the ‘anterior region of each valve. Posteriorly, the raised surface forms a thickened ridge which parallels the posterior margin. The surface anterior to the ridge is flattened, almost concave. A strong series of fine linear ridges arranged in a subconcen- tric pattern, mark the entire surface, including the posterior ridge and the anterior spines. Remarks.—This species is more elongate than Bufina elongata Coryell and Malkin (15). There is no marked variation in height between the anterior and posterior ends as in other species, and the general shape is more rectangular. The surface striations are typical of this new species. Stewart (16) described a related species, Moorea bicornuta Ulrich, from the Silica shale, Ohio. 22 BULLETIN 88 22 Coryell included this latter species in his genus Bufina. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9401. Menoeidina arcuata, n. sp. Plate 1, figs. 11, 14 The carapace is elongate, arclike in outline. The ratio of length to height is 2.3 to 1. The valves are equally convex, somewhat flattened anteriorly. The thickness increases from posterior to anterior, giving a wedge-shaped appearance in dorsal view. The dorsal margin is convex, with a long gradual posterior slope rising to the point of greatest convexity in the anterior half of the margin. The cardinal angles are obtusely rounded. The posterior margin is narrowly rounded; the anterior margin is blunt, almost straight without backward swing. The ventral margin is straight, with a slight concavity at mid-length. The greatest length measured in the ventral half is 0.63 mm., the greatest height 0.27 mm., measured in the anterior half, the greatest thickness, also, in the anterior half, 0.25 mm. The right valve overlaps the left very slightly posteriorly and ventrally. The surface of the valves rises abruptly from the anterior end and forms a thickened ridge. Dorsally the ridge diminishes, ventrally it terminates in a short blunt spinelike projection. A number (approximately 12 or 13) of relatively large, coarse, equally spaced pits or puncte are arranged in a somewhat regular fashion on the surface of each valve, immediately posterior to the anterior ridge and not extending to the centre of the valve. The remainder of the surface is smooth. The pits are constant in their occurrence and striking in their restricted distribution. Remarks.—Menoeidina arcuata is smaller and more elongate than M. subreniformis Stewart. The height increases from pos- terior to anterior, rather than from anterior to posterior, as in the latter species. The more restricted anterior ridge with the spine- like ventral termination and the strongly pitted anterior area serve to completely distinguish the two species. Although distinct specific differentiation is recognized, little hesitation is felt in referring these two forms to the same genus. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9402. 23 DEVONIAN OSTRACODA: TURNER 23 Genus PONDERODICTYA Coryell and Malkin, 1936 (Am. Mus, Nov., No. 891, Nov., 1936, p. 15) Ponderodictya punctulifera (Hall) Plate 1, fig. 7 Leperditia punctulifera Hall, 1860, N. Y. State Cab., 13th Ann. Rep., p. 92, Primitiopsis punctulifera Jones, 1890, Geol. Soc. London, Quart. Jour., vol. 46, p. 9, pl. 2 figs. 7, 12, 13. Cytherella ? bispinulatus Stewart, 1927, Ohio Geol. Sury., 4th ser., Bull. 32, p. 60, pl. 5, figs. 18, 19. Primitiopsis unicornis VanPelt, 1933, Jour. Pal., vol. 7, p. 326, pl. 59, figs. 23-28. Cytherellina punctulifera Warthin, 1934, Mus. Pal., Univ. Mich. Contr., vol. 4, No. 2, pp. 222, 223, pl. 1, figs. 24, 25. Ponderodictya bispinulata Coryell and Malkin, Noy. 1936, Am. Mus. Noyv., No. 891, p. 15, figs. 28, 28a, 29, 30. Hamiltonella punctulifera Stewart, 1936, Jour. Pal., vol. 10, No. 8, p. 756, pl. 102, figs. 1-5. Ponderodictya punctulifera (Hall) is the most abundant and characteristic species of this ostracode fauna. In this area, as in each of the areas from which it has been described, the species shows great variety of form and surface markings. The large collection of specimens from these well samples has been studied with a view to determining whether the variations in size, shape, and surface markings were sufficiently constant to constitute distinct species or varieties. As a result of this examination, three more or less distinct types have been recognized. Type I is represented by large, convex, subreniform specimens with two prominent posterior spines and an anterior tubercle on each valve. The surface is coarsely reticulate. In general, all the surface features are more strongly developed on the right valve than on the left, although in certain specimens the ante- rior tubercle only, is weak on the left valve. The typical shape in this group is subovoid with the height slightly more than half the length. Other forms are more elongate, while a third variety, distinctly ovoid in outline, is more obese. A similar type has been described from the Silica shale, Ohio. Type II has the ventral posterior spine only, developed on each valve. The anterior tubercle shows a weaker development on both valves and, in some instances, it is entirely lacking on the left valve. Variations in the ratio of height to length and in the relative convexity of the carapaces, similar to those described in 24. BULLETIN 88 24. the first type, are also present here. This second type corresponds closely to one described from the Silica shale. The latter, however, shows no anterior tubercle developed on the left valve. Type III has the posterior spines and anterior tubercle de- veloped on the right valve, but they are completely absent from the left valve. The reticulations on the left valve of some speci- mens are indistinct, especially towards the margins, where they have the appearance of being worn. Weathering of specimen be- fore fossilization, may account for the lack of surface characters in some cases. In spite of this fact, however, other specimens do appear with well marked reticulations and no nodes on the left valve. In addition to the above types, a number of small, subquad- rangular specimens with coarse reticulations and well developed spines and tubercles have been observed. These were at first considered to form a distinct variety, but on considering the species as a whole, they appear to be individual variations, prob- ably small sized mature forms. An attempt was made to use these so-called varietal types as detailed zone markers, but the results proved unsatisfactory. The study of this large collection of specimens of the species Ponderodictya punctulifera, has shown that differences which may appear of great significance when small collections are considered, are in reality merely developmental stages in the growth of the individuals of the species. Certain variations, particularly those of size and convexity, are regarded as sex differences. The large more ovoid and more obese forms are considered to be the females of the species. The state of preservation undoubtedly accounts. for many in- consistencies of shape and surface markings. Some specimens are internal casts and lack surface reticulations. As pointed out, in the third type, the smooth surface with indistinct markings may have been produced by weathering before burial of the speci- mens was effected. The left valve commonly shows the worn appearance; since it is the larger valve and overlaps the right on all margins, it would of necessity be more exposed. 25 DEVONIAN OSTRACODA: TURNER 25 Genus SPINOVINA Coryell and Malkin, 1936 (Am. Mus. Nov., No. 891, Nov. 1936) Spinovina distributa Coryell and Malkin Spinovina distributa Coryell and Malkin, Nov. 1936, Am. Mus. Noy., No. 891, p. 17, fig. 37. A number of specimens have been isolated from those referred to the genus Quasillites because of their more ovate outline and more prominent surface ridges. These specimens are also more tumid than the typical Quasillites. They resemble Spinovina dis- tributa more closely than any of the species of Ouasillites. The distinction between these specimens and those placed in Ouasillites is not very striking. One of the distinguishing fea- tures of Spimovina, as indicated by Coryell and Malkin, is the deep sulcus on the dorsal margin. The specimens of Quasillites, however, in this collection have equally well developed sulci on the dorsal margin. Both genera have the typical ridged surface, anterior spine and posterior crest. The differentiation of the two genera is not very clear; Spinovina, as at present defined, might easily be regarded as a species of Quasillites. Genus QUASILLITES Coryell and Malkin, 1936 (Am. Mus. Nov., No, 891, Nov. 1936, p. 18) Quasillites oliquus Coryell and Malkin Plate 1, figs. 15, 18 Quasillites obliquus Coryell and Malkin, Noy. 1936, Am. Mus. Noy., No. 891, p. 18, figs. 36, 36a. Coryell and Malkin’s description of this species is as follows :— Carapace oblique rhomboidal; hinge line straight, partly covered by the overlap of the right valve in the posterior portion. Cardinal angles obtuse, the posterior larger than the anterior. Ventral margin straight, with broadly curved extremities. Anterior end narrowly rounded in the upper half, with an oblique backward swing in the lower half; posterior end narrowly curved in the lower half. and truncated dorsally. Surface marked by faint longitudinal lines typical of the genus, bifurcating from a median line along the crest of the convexity and diverging anteriorly. A very insignificant posterior ridge is present at the crest of the short steep poste- rior slope of the surface of the valve; a prominent antero-ventral spine projects forward from the crest of the slope where the convexity of the valve dips steeply to the anterior margin. A less ornamented median area is present near the centre of each valve. Right valve, overlaps the left on free margins and on part of dorsal margin; right valve is grooved to receive the free margins of the left valve. Greatest convexity is located near the centre of the anterior half; height practically uniform through- out; dorsal and ventral margins are parallel. Length.—1.10 mm. Height.—0.55 mm. Remarks.—The specimens placed in this species correspond to the above description in every respect, except for a distinctly 26 BULLETIN 88 26 channelled hinge in the anterior two-thirds of the dorsal margin, and a flattening of the valves in the posterior dorsal region. These differences are not sufficient to warrant a separation from the type species. In addition to the large typical forms, there are numerous specimens which are small and more convex. The posterior ven- tral region is less protuberant and the anterior margin is more truncate. In other respects they resemble the larger form, and are readily recognized as belonging to this species. Some typical specimens of this species were sent to Dr. Coryell at Columbia University for examination. In a personal communi- cation, he suggested that they represented a new species owing to their more rectangular shape. This second group as outlined above might form a new species, but in the opinion of the writer, stich a division of these forms is not warranted. Quasillites reticulata, n. Sp. Plate 1, fig. 10 The carapace is elongate-ovate with moderate convexity. The ratio of height to length is 1 to 2. The dorsal margin is slightly convex, with a very narrow sulcus in the anterior two-thirds. The cardinal extremities are obtuse, the posterior flattened and elongate, the anterior rounded. The posterior margin is rounded with the border widened and finely crenulated in the post ventral part; the anterior margin has a slight ventral backward swing. The ventral margin is straight or slightly convex. The greatest length, measured slightly above the mid-line is 0.60 mm., the height 0.30 mm., the thickness 0.20 mm. in the anterior half. The right valve overlaps the left ventrally and anteriorly. A minute spine projects forward from the antero-ventral re- gion. The surface of the valves rises steeply from the anterior and posterior margins. The linear markings are very fine and are united by fine crossbars, which produce a reticulate appear- ance. The linear ridges diverge from the smooth central unorna- mented spot. Remarks.—This species differs from the other species of Oua- sillites in its smaller size and more ovate outline. It lacks the 27 . DEVONIAN OSTRACODA: TURNER 27 strong posterior-ventral swing of Q. obliquus. The crenulations on the postventral margin and the fine reticulate markings serve as further distinctions. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9403. Quasillites fordei Coryell and Malkin, var. minimus, n. var. Plate 1, fig. 18 Quasillites fordei Coryell and Malkin, Nov. 1936, Am. Mus. Nov., No. 891, p. 18, fig. 38. The description of the type species is as follows :— Carapace sub-oblong; hinge line straight; ventral margin straight except where it curves to meet the rounded ends of the valves; anterior end almost straight, with backward swing, height about two-thirds as great as the pos- terior end; anterior cardinal-angle slightly obtuse; posterior cardinal angle greater than anterior; greatest extension of posterior margin is near ventral edge. Surface of valves is covered by fine ridges, an outer set paralleling the outer margins of the valve, and the two inner sets each roughly con- centric in the anterior and posterior halves of the valve and converging towards an indefinite transverse cincture which extends from the dorsal to the ventral margin a little posterior to the centre of the valve. The fine ridges are connected, rarely, by very thin dissepiment-like cross-bars. A poorly defined central spot is present. A small spine projects forward from the antero-ventral region, close to the margin. Surface of valves slopes very gradually to the anterior edge; the posterior surface is slightly more convex than the surface of the anterior half, and the slope to the posterior margin is more abrupt with a slight swelline at the crest of this slope. Greatest height is located about one-fourth of che length from the posterior margin. Length—0.68 mm. Height.—0.40 mm. Quasillites fordei, var. minimus is small, elongate, and subquad- rate. The ratio of height to length is somewhat more than I to 2. The valves increase in height in the posterior half. The dorsal margin is straight, in some specimens slightly con- vex, rising at the posterior end. There is a distinct sulcus in the anterior two-thirds. The cardinal angles are obtuse and evenly rounded, the anterior is slightly less obtuse than the posterior. The posterior margin is broadly and evenly rounded; the anterior margin is almost straight with a slight backward swing. The ventral margin is straight. The posterior contact margin is some- what wider than the anterior and finely crenulated in some speci- mens. The valves measure 0.61 mm. in length slightly below the mid- line, 0.27 mm. in height in the posterior half, decreasing by one- third of this in the anterior half. The right valve overlaps the left on the ventral margin and to a lesser extent on the ends. 28 BULLETIN 88 28. There is a small sharp spine in the anterior-ventral region. The surface has strong linear markings arranged in a subconcen- tric manner. Remarks.—This variety of Quasillites fordei differs from the type species in the presence of the sulcus on the dorsal margin, and lacks the abrupt slope to the posterior margin, the valves being more uniformly convex. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9404. Genus JENNINGSINA Coryell and Malkin, 1936 (Am. Mus. Nov., No. 891, Nov. 1936, p. 19) Jenningsina concentrica, n. sp. Plate 1, fig. 16 The carapace is subrectangular to subrhomboidal in outline. The valves are flattened laterally. The ratio of length to height is slightly more than 2 to I. The dorsal margin is straight, rising at the posterior and ante- rior extremities where the marginal rim extends around the car- dinal angles. The latter are obtuse, the posterior being the more obtuse. The posterior margin is broadly rounded, more protuber- ant in the ventral half; the anterior margin is truncate, almost straight, with a backward swing in the ventral part. The ventral margin is straight, with a slight central sinuosity. The specimens have an average maximum length at mid-height of approximately 0.62 mm., the height varies considerably among them, averaging from 0.25 mm. to 0.32 mm. The height in all forms decreases anteriorly. The right valve overlaps the left on the free margins, the overlap being greatest in the centre of the ventral margin. The surface of the valves rises steeply from the anterior margin leaving a narrow marginal rim which continues along the anterior ventral and dorsal margins short distances. Posteriorly, the rise is less abrupt, but the marginal rim is wider and extends up around the post-dorsal margin, and also, continues ventrally along the ventral margin one-third of its length. A number of minute papilla project beyond the edge of the posterior marginal rim in the ventral half, On both valves a sharp spine projects obliquely forward from 29 DEVONIAN OSTRACODA: TURNER 29 the antero-ventral region. There is a small blunt spine or node, in a corresponding dorsal position in some specimens. On the surface of each valve a series of subconcentric ridges, which begin in a triangular pattern in the anterior half of the cara- pace, gradually enlarge to encircle the whole surface. The ridges are connected with crossbars at intervals slightly longer than the distance between the ridges, making series of elongate reticula- tions. Towards the margins, the ridges are closer together and there are no crossbars developed. Remarks.—This species differs from J. catenulata (VanPelt), in the more elongate shape and subrhomboidal outline. The anterior dorsal and posterior ventral regions are more protuber- ant in J. concentrica, while in the other species, both margins are protuberant ventrally. The surface ridges are distinctive in their concentric pattern, which results in the ridges forming parallel lines around the margins. In J. catenulata they diverge from a median line. VanPelt’s specimens are described as having anterior nodes or spines similar to those in J. concentrica, but Coryell neither de- scribes nor figures these structures. Holotype.—Collections of the Geological Survey of Canada, Ottawa, No. 9405. SUMMARY AND CONCLUSIONS As a result of this investigation, it has been shown that the majority of the ostracodes from the well cuttings are typical Middle Devonian forms. Some species, however, e. g. Hollinella subcircularis, n. sp., have Pennsylvanian affinities, while others, e. g. Eukloedinella doverensis, n. sp., suggest certain Silurian species. Among the characteristic Middle Devonian species are: Ponderodictya punctulifera (Hall), Dizygopleura trisinuata Van Pelt, Euglyphella sigmoidalis (Jones), and Amphissites subquad- ratus (Ulrich). Nine new species, two new varieties, and one new genus have been added to the rapidly growing list of Middle Devonian ostra- 30 BULLETIN 88 30 codes. The genera Lucasella and Menoeidina are recorded for the first time outside of their type locality in the Silica shale, Ohio. Two other genera, Quasillites and Spinovina, described originally from the Widder beds, Ontario, are recorded only for the second time. When this study was initiated, it was hoped that minor zones might be established within the Upper Ostracode zone, which could be effectively used in working out the stratigraphy. As the study proceeded, however, it did not seem possible to recog- nize such faunal units. In the Silica shale, Ohio (17), certain species have been found to occur in abundance in the various lithological units. In the Tra- verse group of Michigan (18), a broader zoning of certain species has been recognized. In the area under consideration well samples have been taken at regular intervals from approximately one hundred feet of the Hamilton shales. Through this thickness of strata the more abun- dant species are distributed quite uniformly. The rarer species, though they might seem to be confined, could scarcely be con- sidered as zone markers since there is no uniformity in their order of appearance in the various wells. The study of microfossils has been greatly accelerated within recent years, because of the important role they have played in the field of petroleum geology. The ostracodes are one of the most satisfactory groups of microorganisms to study on account of their diversity of form and their widespread occurrences both geographically and geologically. Since the ostracodes which have been discussed were obtained from the important oil and gas fields of southwestern Ontario the present study has a distinct eco- nomic bearing; an added significance is, therefore, given to this investigation. al ee eu ace Ne 2 90 10. 11. 12. 13. 14. 15. 16. alee 18. DEVONIAN OsTRAcoDA: TURNER 31 REFERENCES Fritz, M. A., Bull. Geol. Soc. Am., vol. 50, 1939, pp. 79-88. Nicholson, H. A., Pal. of Prov. of Ont., 1874, p. 124. Jones, Rupert T., Geol. Soc. London, vol. 46, 1890, p. 542, 543. Stauffer, C. R., Geol. Surv. Canada, Mem., 34, 1915, p. 237. Coryell, H. N. and Malkin, Doris, Am. Mus., Nov., No. 891, Nov. 1936. VanPelt, H., Jour. Pal., vol. 7, No. 3, 1933 pp. 325-342. Warthin, A. S., Mus. Pal. Univ. Michigan Contr., vol. 4, No. 12, 1934, pp. 205-226 Stewart, G. A., Jour. Pal., vol. 10, No. 8, 1936, pp. 739-763. Coryell, H. N. and Booth, R. T., Am. Mid. Nat., vol. 14, 1933, p. 262. Coryell, H. N. and Malkin, Doris, Am. Mus. Nov., No. 891, Nov. 1936, p- 5, fig. 13. tewart, G. A., Jour. Pal., vol. 10, No. 8, 1933, p. 746, pl. 100, fig. 15. Harlton, B. H., Jour. Pal. vol. 7, No. 1, 1933, p. 19-20, pl. 6, figs. 9a, 9b. Ulrich, E. O. and Bassler, R. S., Maryland Geol. Surv., Silurian, 1923, p- 683, pl. LIX, fig. 26. Spivey, R. C., Jour. Pal., vol. 13, No. 2, 1939, p. 172, pl. 21, figs. 22, 33. Coryell, H. N. and Malkin, Doris, Am. Mus. Noy., No. 891, Nov. 1936, p. 9. Stewart, G. A., Jour. Pal., vol. 10, No. 8, 1936, p. 752, pl. 100, fig. 29. Stewart, G. A., Jour. Pal., vol. 10, No. 8, 1936, p. 740. Warthin, A. S., Mus. Pal. Univ. Michigan Contr., vol. 4, No. 12, 1934, pp. 206-207. 32 BULLETIN 88 EXPLANATION OF PLATE 1 (1)* Figure 1. Haploprimitia punctata, n. sp. — Right valve. 2. Ulrichia fragilis Warthin, var. subnodata, n, var. Left valve. 38. Halliella bellipuncta Van Pelt Left valve. “4: Boursella trilobata, n. sp. — —— — — Right valve with view of hinge. 5. Eukloedinella doverensis, n. sp. —.- Left valve. 6. Dizygopleura sculptura, n, sp. = = Left valve. 7. Ponderodictya punctulifera (Hall) Right valve, X20, 8. Eukloedinella doverensis, n. sp. —— pea reee eee S Pits Hinge view. See Buhinaslineata, iiss pe es ee ee Left valve. 104 Quasillites reticulata, in. Spy 22.22.0220 2 Left valve. dis (Menoeidinas arcuata, n., Sp. 22222 eee 12 sBudina, lineata, on, Spy 222 = Loo eee 1 ae Ce Hinge view. 13. Quasillites fordei Coryell and Malkin, var. minimus, n. var. __ Left valve. 4. Menoeidina arcuata, nitsp. 28. ee eee 15. Quasillites obliquus Coryell and Malkin _ Left valve of smaller type. 16. Jenningsina concentrica, n. sp. Lefit valve. Lets MEL OWING Tae VS pis 5, eee eae a ee eee Left valve. 18. Quasillites obliquus Coryell and Malkin _.... Hinge view. LOS Hollinellay sraniferars: (Wich) Right valve. 20. Hollinella subcircularis, n. sp. Left valve. 15 ‘17 *(All specimens are magnified 40 diameters unless otherwise indicated). Pu. 1, Vou. 25 Buu. AMER. PALEONT. No. 88, Pu. 1 Lh A WR NG al 2 bee ot Ba aT TI eon BULLETINS AMERICAN PALEONTOLOGY sg eet Oe Ne Vg om INSTI VOL: KXV Mp 13 1930. NUMBER 89 1939 Paleontological Research Institution IrHaca, N. Y. | eres ee St A,™ ¥ BULLETINS OF AMERICAN PALEONTOLOGY Volume 25 Number 89 Eight Species of Pennsylvanian Crinoids By HARRELL L. STRIMPLE August 23, 1939 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaca, New York lo Ss ANS - t a GISNl SIMvCUsES Ol JAIN INS YODVAINILAIN (CIRIUN ODS By HARRELL L. STRIMPLE The original form described as Cyathocrinus stillativus White has never conformed with any known genus. II’hiteocrinus, n. g. is herein proposed for its reception, and a new form JIhiteocrinus exsculptus, n. sp., described thereunder. Poteriocrinites ramona- énsis, N. Sp., 18 a form from near Ramona, Oklahoma, with which a new ontogenetic theory is proposed. From the Wewoka forma- tion near Holdenville, Oklahoma now comes a form identical with, and presented as Poteriocrinites magnus Wright. Wright’s specimens come from the Lower Limestone series of the Scottish Carboniferous, which is generally correlated with the Chester group, Upper Mississippian (Upper Carboniferous) of North America, whereas the specimens at hand are from the Middle Pennsylvanian (Upper Carboniferous). This occurrence then opens the possibility that the stratigraphic range of the Scottish Carboniferous might possibly extend into the North American Pennsylvanian period. At least there is room for conjecture. Utharocrinus granulosus, n. sp., is of particular interest since we have here the arms, tegmen, and growth stages. In dealing with immature forms in Pennsylvanian strata we must proceed with rigid care, which is, however, to be tempered with sensible judgment. There are at hand two distinct small forms which are rather common in the locales under observations, yet large similar specimens have not been observed. If larger specimens are later found, yet the relationship with these small forms never established through lack of growth stages, there will be no great harm done since each form will serve its purpose as a distinct, determinable unit. It is to be noted that there are a few similar forms which have not been included since they have not been observed in complete enough preservation for accurate generic determinations. Those two under consideration are described herein as Scytalocrinus deminutivus, n. sp., and Scytalo- crinus larvalis, n. sp. 4 BULLETIN 89 36 I am indebted to my wife, Mrs. Melba Strimple, for her usual good collecting and assistance, as all specimens herein figured were collected either by her, or the author, save those figured as Poteriocrinites magnus Wright which were collected by Mr. Audd Dailey of Holdenville, Oklahoma. Order INADUNATA Wachsmuth and Springer Suborder FISTULATA Wachsmuth and Springer Family CYATHOCRINIDA Roemer (Emend. Wachsmuth and Springer) Genus WHITEOCRINUS, n. g. Genotype-—Whiteocrinus stillatwus (White). White described an unusual form as Cyathocrinus stillatiwus. Wachsmuth and Springer (1886) listed the same under Cyatho- crinus but noted that it probably belonged elsewhere. Keyes (1894) referred the same to Phialocrinus, whereas the form is quite distinct from any known genus. Cup composed of five IBB, BB, and RR, with three anal plates ; one hexagonal plate followed more or less evenly but two slight- ly smaller hexagonal plates, those later being within the cup most- ly by virtue of the high articular facets of the RR; all plates of the cup strongly ornamented; the basal area depressed. The arms are known to branch once on the stout IBr‘; brachials rapidly becoming wider than high, pentagonal-shaped, interlock- ing, forming wide strap like biserial arms which exhibit a strong tendency to coil so that one frequently finds small portions in a tight roll. It is known that at least some plates of the tegmen are protruded as spines, In addition to the genotype there are known Whiteocrinus exsculptus, n. sp., another species, figured herein as Whuteocrinus, sp. indet., and Whiteocrinus angulatus’ (Miller and Gurley). Occurrence and horigon.—Pennsylvanian (Upper Carbonifer- ous) ; North America. 1 Miller, S. A., and Gurley, Wm. F. E.: Description of some new species of Invertebrates from the Paleozoic rocks of Illinois and adjacent States Illinois State Museum of Nat. Hist., Bull. No. 3, 1893, p. 59, pl. 6, fig. 9 (as Aesiocrinus). 37 PENNSYLVANIAN CRINOIDS: STRIMPLE 5 Whiteocrinus stillativus (White) Plate 1, figs. 1, 2, 9 Cyathocrinus stillativus White, 1880, Proc. Nat. Mus., vol. II, p. 258; 1880, Geol. Surv. of the Territories, p. 125, pl. 35, figs. 3a, b. Cyathocrinus (%) stillativus Wachsmuth and Springer, 1886, Revision of the Paleocrinide, Part 3; Proc. Acad. Nat. Sciences, Phila., p. 226. Phialocrinus stillativus Keyes, 1894, Geol. Survey Missouri, vol. 4, p. 219, pl. 28, figs. 6a, b. This species has been adequately described, and only certain points are especially brought out here. Just below the articular facets of the RR, two strong ridges pursue divergent courses to the lower extremity of the plate where they are matched by simi- lar occurrences in the BB, as also the strong depressions about the raised area are confluent. The upper lateral extremities are slightly tumid but do not form strong ridges. This system of adjoining tumidity is also carried into the anal series of the cup. The lower portion of BB exhibits various specialized protuber- ances, normally a very sharp vertically developed ridge, after which there is a strong drop to the more or less flattened basal area, the same being occupied by the IBB. The specimen with which we have knowledge of the arms of this species is unfortunately poorly preserved, nevertheless ade- ~ quate for observation. The arms branch once on the rather low, wide IBr'*, following brachials rapidly becoming low symmetrical five sided interlocking plates, forming wide straplike biserial arms. There is a tendency for the outer portions of the arms to become slightly protuberant after which they curve strongly under. The stem is composed of round, alternating, expanding, rather thin columnals, with strongly crenulated circumference, said cren- ulations being easily visible from side view, and pierced by minute round axial canal. Of the tegmen it is known that some of the plates are pro- truded as spines. Occurrence and horizon.—Stanton limestone member, Oche- lata group, Pennsylvanian, the mound just west of the city limits of Bartlesville, Oklahoma. Figured specimens.—Springer Collection of the U. S. National Museum. Whiteocrinus exsculptus, n. sp. Plate 1, figs. 7, 8 This species is identical in general structure with W/iteocrinus 6 BULLETIN 89 38 stillativus, and WV. angulatus, differing in ornamentation and sub- sequent tumidity of the plates, being therein quite distinct. The outer surface of RR are gently tumid as a whole, the only erratic development being just below the articular facet where two small sharp ridges are formed, following divergent courses to the lower portions of the plate, but not quite reaching the sutures, and not being matched by similar development on the BB. The lower portions of the BB are protruded, but rather regularly, so that a strong pentagon is formed when viewed from below, and the sub- sequent drop to the floor of the base is very gentle. Cup 19.1 mm. wide by 9.3 mm. high. Stem and tegmen unknown. Occurrence and horizon.—Stanton limestone member, Oche- lata group, Pennsylvarua, the mound just west of the city limits of Bartlesville, Oklahoma. T ype.—Springer Collection of the U. S. National Museum. Whiteocrinus, sp. indet. Plate 1, figs. 3, 4 This specimen is presented to give a more comprehensive con- ception of the arms of these forms. Please note that the arm shown to the extreme left in pl. 1, fig. 4, is the under side of that arm shown in pl. 1, fig. 3, also to the extreme left. The species is distinct from any known species in that an associated RR is found to have three sharp ridges pursuing divergent courses from just below the articular facet, one being interposed between the normal two. It is thought more fitting to wait for a more com- plete specimen before attempting to establish the species. Occurrence and horizon.—Stanton limestone member, Oche- lata group, Pennsylvanian, the mound just west of the city limits of Bartlesville, Oklahoma. Figured specimen.—Springer Collection of the U. S. National Museum. Family POTERIOCRINITIDZ Bassler Genus POTERIOCRINITES 5. J. Miller Presenting here under, Poteriocrinites ramonaénsis, n. sp., 39 PENNSYLVANIAN CRINOIDS: STRIMPLE 7 which is suggested to possibly represent a link with Ethelocrinus Kirk, exemplified by E. plattsburgensis? Strimple, and E. con- and elimination of the right tube plate, you have a form quite close to E. convexus, which is in turn very close to E. platts- burgensis. This theory is advanced only for those forms specifi- cally mentioned, as there seems to be some differences within the Ethelocrinus. Also presented as, and identical with, Poteriocrinites magnus Wright are some dissociated plates from near Holdenville, Okla- homa. Poteriocrinites ramonaénsis, n. sp. Plate 1, figs. 5, 6 Calyx rather high, turbinate-shaped, diameter 20 mm., height 16 mm.; IBB 5 pentagonal plates easily visible from side view, rising directly from the round flat area occupied by the proximal columnal; BB 5 large, slightly tumid, very thin, hexagonal plates save that of the posterior which is truncated for the reception of the rather large anal X, and carries obliquely, together with the r. post. B, the large radianal; RR five, rather large, pentagonal elements, distal portions slightly constricted giving a swollen ap- pearance, facets developed mildly as shelves, slanting inward, not quite filling face of RR, ligamental furrow to the fore adjoined by strong cross ridges, the muscle scars taking the form of shallow grooves centering at a shallow rounded depression in the median portion of the articular facet; anal series consisting of three large plates, anal X hexagonal, resting broadly on post. B, distal portion extended out of cup and curved strongly inward, radianal pentagonal, resting obliquely on post. B, supported by r. post. B, and supporting above the right tube plate, which is pentagonal with upper extremity extending out of cup, and followed by two azygous plates, that to the left being small and quadrangular. Of the arms only the first few brachials of one ray are definite- ly known, ten cuneiform arms branching on IBr* are indicated. IBr? low, slightly constricted laterally, I[Br* rather squat, stout 2 Strimple, Harrell L.: A group of crinoids from the Pennsylvanian of northeastern Oklahoma, 1938, p. 10, pl. 2, figs. 6, 9, 12. vexus® Strimple. By lowering the IBB disk of P. ramonaénsis 3 Strimple, Harrell L.: A group of Pennsylvanian crinoids from the vicinity of Bartlesville, Oklahoma, Bull. Amer. Paleont., vol. 24, No. 87, 1939, p. 13, pl. 1, figs. 11, 12, 15, 16. 8 BULLETIN 89 40 with strongly rounded back, and deeply notched by ambulacral groove. Round stem composed of alternating expanded columnals, minor crenulations about the edge, axial canal small and penta- lobate. Relationship.—This species is considered closely related to, and the possible predecessor of, Ethelocrinus convexus. The form is quite distinct from other known species of the genus. Occurrence and horizon.—Stanton limestone member, Oche- lata group, Pennsylvanian, the mound 3144 miles due west of Ra- mona, Oklahoma. Type.—Springer Collection of the U. S. National Museum. Poteriocrinites magnus Wright Plate 1, figs. 10-12 Poteriocrinites magnus Wright, 1937, Geol. Mag., vol. LX XIV, No. 879, p. 405, pl. 14; fig. 1. Cursory examination proves the specimens at hand to be iden- tical with P. magnus. Note especially the sharp, squared off lower | extremity of the articular facet. As previously mentioned, Wright’s specimens come from the Scottish Carboniferous, Lower Limestone series, whereas these specimens were collected by Mr. Audd Dailey of Holdenville, Oklahoma, from the Wewoka form- ation, Middle Pennsylvanian (Upper Carboniferous). Figured specimens.—Springer Collection of the U. S. National Museum. Genus UTHAROCRINUS Moore and Plummer Utharocrinus granulosus, n. sp. Plate II, figs. 1-7 Crown of immature specimen measures 10.3 mm. to tip of arms; width of smallest observed calyx 3.4 mm.; height 2 mm.; wormal calyx 10.5 mm. wide, by 4 mm. high. Calyx flaring bowl-shaped; base depressed only in that the lower portions of BB are protruded; IBB disk flattened and oc- cupied in the main by columnar scar, which is slightly depressed ; IBB 5 small, pentagonal elements; BB 5 large hexagonal elements, sawe that the post. which is truncated for the reception of anal X, normally, lower portions are very tumid and possess a vertically developed, very thin, sharp, spinelike node in median section of 41 PENNSYLVANIAN CRINOIDS: STRIMPLE 9 plate; lower extremity curved under to form portion of the basal area; RR 5 pentagonal elements, tumid, articular shelves de- veloped slightly outward; lateral extremities rather high, with strong notch at sutures; ambulacral groove strong; ligamental furrow to the fore sharp but not large; cross ridge rather prom- inent ; muscle scars well developed as wide shallow depressions. Anal series within the cup normally three small, slightly elongated plates, very erratic placement. Under normal conditions the anal X is hexagonal, supported by the post. B, extending slightly out of cup; radianal pentagonal, resting on the post. B, supported by r. post. B, and in turn supports the small, hexagonal right tube plate. Specimens have been observed wherein the radianal is irregularly quadrangular, resting directly on post. B and supporting anal X above, the right tube plate having been entirely eliminated from the cup. Transitional stages between the extreme noted, and nor- mal occurrence as described, have been observed. The arms are ten in immaturity, branching once on IBr*. In mature forms they are known to branch again on IIBr* or IIBr'’, and probably once more in some rays. ‘Three, or more, small, sharp, spinelike nodes are developed horizontally across lower ex- tremity of [Br', that in center followed vertically by several simi- lar nodes, intervening spaces raised as a sharp ridge, that of the apex being stronger than the others, and protruded. This raised ray continues to the tip of the arms. The 1. post. IBr*, and ant. UB, aie Clomeeiescl, ve, gine, Wee, ehaGl I, aioe, WeieS Weiny Sla@ime vin comparison, r. post. IBr* just slightly shorter than the longest. Tegmen is apparently composed of 4 small hexagonal plates to the row, and extends slightly beyond the arms in maturity. At the uppermost extremity there is a circlet of elongated spinelike, flattened plates, extending upward as a crown, The proximal columnals are known, same being thin, alternat- ing expanded, round, apparently the surface is rough as in the rest of the crinoid, and pierced by a minute, round axial canal. In addition to the strong ornamentation previously noted, the entire surface of the calyx and arms are thickly covered by minute, spinelike nodes. 10 BULLETIN 89 42 Relationship.—Utharocrinus pentanodus* (Mather) is the only other known species, same having considerably stronger devel- oped protuberance of the BB, and lacking the strong ornamenta- tion of the form at hand. Occurrence and horizon.—Stanton limestone member Oche- lata group, Pennsylvanian, the mound just west of the city limits of Bartlesville, Oklahoma. Types.—Springer Collection of the U. S. National Museum. Genus SCYTALOCRINUS Wachsmuth and Springer Only one species has been assigned to this genus, from the Pennsylvanian strata to date, that being S. sansabensis® Moore and Plummer. It is to be noted, however, that text fig. 19 dis- tinctly shows the |. post. primibrach as being axillary, and both of the secundibrachs of said ray being axillary, therefore the species is certain to have more than ten arms as is characteristic of the genus. Herein described are Scytalocrinus larvalis,n. sp., and Scytalocrinus deminutivus, n. sp. Scytalocrinus larvalis, n. sp. Plate 2, figs. 11-13 It is possible that this form becomes rather iarge with maturity, but since it is rather common in the locales under observation, and no large specimens have appeared over the past several years, it is doubtful that the form ever becomes very robust. Smallest observed specimen measures 4.0 mm. to tip of arms. Normal specimen measures 7.0 mm. to [IBr'. Cup turbinate-shaped; IBB5 equal pentagonal elements, ris- ing directly from columnar scar; BB 5 large, equal, hexagonal elements, slightly higher than wide, that of the posterior being truncated for the reception of anal X, and larger than others, plates gently tumid; BB 5, smali, equal, pentagonal elements, articular facets unknown beyond the fact that they are extended inward slightly as horizontal shelves and are sharply notched by a smali ligamental furrow to the fore; anal series of three plates; 4 Mather, Denison Univ. Sei. Lab., Bull., vol. 18, 1915, p. 106, pl. 3, figs. 8, 8a, b, (as Delocrinus) ; Moore, R. C., and Plummer. F. B., Denison Univ. Sci. Lab., Bull., vol. 32, 1958, pp. 286-288, text fig. 31 (as Utharo- crinus) . 5 Moore, R. C., and Plummer, F. B., Denison Univ. Sci. Lab., Bull., vol. 32, 1938, pp. 247-250, pl. 14, figs. 9a b; text fig. 9. 43 PENNSYLVANIAN CRINOIDS: STRIMPLE 11 anal X elongo-hexagonal, resting solidly on post. B; radianal elongo-pentagonal, resting obliquely on post. B. supported by r. post. B; right tube plate small, hexagonal, resting on radianal, half in half out of cup. Of the arms our knowledge is limited to the IIBr', above which is unknown. The IBr* are the most elongated of any forms yet observed, and are axillary. The stem is known from proximal columnals only, the same being round, like elongated beads, heavily crenulated so that cren- ulations are visible from side view, and pierced by minute, round axial canal. Tegmen unknown. Ornamentation.—Aside from distinctive porosity, small nodes are visible under strong magnification, and a thin ray runs the length of IBr', the backs of [Br being almost triangular- shaped. Occurrence and horizon.—PI. 2, fig. 13,—Shale-limestone lens between the Okesa sandstone and Torpedo sandstone members, Ochelata group, Pennsylvanian, 5 miles southwest of Bartlesville, Oklahoma. Pl. 2, figs. 11, 12,—Stanton limestone member, Ochelata group, Pennsylvanian, the mound just west of the city limits of Bartlesville Oklahoma; specimens observed from—Stanton lime- stone member, Ochelata group, Pennsylvanian, 34 miles due west of Ramona, Oklahoma; Stanton limestone member, Missouri series, Pennsylvanian, near Wayside, Kansas. Types.—Springer Collection of the U. S. National Museum. Scytalocrinus deminutivus, n, sp. Plate 2, figs. 8-10 The figured crowns are immature, the figured cup more or less mature, the smaller crown measures 6.8 mm. to tip of arms, of which the cup only accounts for 2.0 mm., by 3.0 mm. wide. Large cup measures 5.2 mm. wide, by 3.0 mm. high. Cup turbinate-shaped; IBB 5 small, pentagonal elements, ris- ing slightly higher than wide, that of the posterior being larger than others and truncated for reception of anal X ; RR five, small, equal, pentagonal plates, articular facets developed only slightly inward as horizontal shelves, strong ligamental furrow to the fore, 12 BULLETIN 89 44 joined by pronounced cross ridge; shallow muscle scars developed laterally ; anal series within cup three; anal X hexagonal, resting sclidly on post. B., extending slightly out of cup; radianal pentag- onal, resting obliquely on post. B, supported by r. post. B; right tube plate small, hexagonal, resting solidly on radianal, half in, half out of cup. Arms are known to be ten to IIBr*, branching on IBr', uni- serial. Primibrachs slightly elongated, fully rounded, those of the l. post. and ant. being slightly longer than others, r. ant. and 1. ant. the shortest. Stem unknown save for proximal columnal, which is round, heavily crenulated, and pierced by minute, round axial canal. Tegmen unknown. Ornamentation.—Under strong magnification the plates prove smooth, the porosity in immaturity being very fine meshlike. Relationship.__Immature specimens of this species may at first be confused with S. larvalis, however, the IBr? of the form at hand are fuller all around, not nearly so elongated, as against the thin, almost triangular-shaped backs of the IBrt in S. larvalis, and the minute nodes covering that species. S. sansabensis Moore and Plummer has different type of arm branching. Occurrence and horizon.—Figured specimens, Pl. 2, figs. 8, 10 —Stanton limestone member, Ochelata group, Pennsylvanian, the mound just west of the city limits of Bartlesville, Oklahoma; PI. 2, fig. 9—Dewey limestone, Pennsylvania, Dewey Portland Cement Quarry, Dewey, Oklahoma. Types.—Springer Collection of the U. S. National Museum. EXPLANATION OF PLATES PLATE 1 (2) 14 BULLETIN 89 EXPLANATION OF PLATE 1 (2)* Figure 1, 2, and 9. Whiteocrinus stillativus (White) Fig. 1, view from below, fig. 2, same from above to show arm and fragment of tegmen preserved; fig. 9, well pre- served specimen, from below. Stanton limestone, the mound just west of Bartlesville, Oklahoma. 3,4, 2 Whiteocrinus:sp. indet 2 —————— EE Fig. 1, view from above; fig. 2, same from below, that arm to the extreme left in fig. 1, being to the extreme left, one basal, and two primibrachs shown. Stanton limestone, the mound just west of Bartlesville, Okla- homa. 5,6. Poteriocrinites ramonaénsis, n, sp. —— .W----- Fig. 1, posterior view; fig. 2, anterior view. Stanton limestone, the mound 3% miles due west of Ramona, Oklahoma, 7,8. Whiteocrinus exculptus, n. sp. Fig. 7, view from below; fig. 8, posterior view. Stanton limestone, the mound just west of Bartlesville, Okla- homa. 10-12. Poteriocrinites magnus Wright Fig. 10, radial plate; fig. 11, basal plate; fig. 12, infra- basal circlet, Wewoka formation, near Holdenville, Oklahoma. * All figures natural size Pu. 2, VOL. 25 Buu. AMER. PALEONT. No. 89, Pu. 1 16 BULLETIN 89 48 EXPLANATION OF PLATE 2 (3) Figure Page 1- 7. Utharocrinus granulosus, n. sp. __ poe ne ee 8 Fig, 1, immature specimen, anterior view; fig. 2, small specimen, anterior view; fig. 3, well developed speci- men with portion of tegmen exposed, posterior view; fig. 4, mature specimen, posterior interray to the right; figs. 5 and 6, well developed calyx; fig. 5, view from above; fig. 6, view from below; fig. 7, a group of arms considered as same species, note the protrusion of the tegmen at the tip of arms. Stanton limestone, the mound just west of Bartlesville, Oklahoma, Natural size. 8-10. Scytalocrinus deminutivus, n. sp. — ee aes 11 Fig. 8, immature specimen, right anterior view; fig, 9, slightly larger specimen, posterior interray to the left; fig. 10, large calyx, posterior view. Specimens, fig. 8 and 10, Stanton limestone, the mound just west of Bartles- ville, Oklahoma. Fig. 9, Dewey limestone, near Dewey, Oklahoma. Enlarged X4. 11-13, Scytalocrinus larvalis, n. sp. He SS ale 10 Fig. 11, very immature specimen, right anterior view; fig. 2, right anterior view; fig. 13, posterior view of an- other specimen, Specimen figs. 11 and 12, Stanton lime- stone, the mound just west of Bartlesville, Oklahoma. Fig. 18, shale-limestone lens between Okesa sandstone and Torpedo sandstone members, some 5 miles southwest of Bartlesville, Oklahoma. Enlarged X4. Pu. 3, VOL. 25 Buu. AMER. PALEONT. No. 89, Pu. 2 BULLETINS AMERICAN - PALEONTOLOGY *# VOL. XXV NUMBER SO UES on ©) Paleontological Research Institution Ithaca, New York Li eA oe atte BULLETINS OF AMERICAN PALEONTOLOGY Vol. 25 No. 90 Some Echinoids from the Cretaceous of Texas By William Clyde Ikins January 3, 1940 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaca, New York We Sb Ay WILT aN The writer, William Clyde Ikins, was born January 29, 1916, at Thurber, Texas. He entered The University of Texas in 1933 from which he received his Bachelor of Science degree in Geology with high honors in 1938, He was employed as a student assistant in the Department of Geology from September, 1936 to February, 1938 at which time he was promoted to the rank of tutor. Since then hehas served as such, He served as an assistant geologist in the Bureau of Economie Geology in the summer of 1938. He became a member of Sigma Gamma Epsilon in November, 1936, He acted as secretary-treasurer of the Southwestern Geological Society in the school year 1938-1939. He was elected an associate member of the Society of the Sigma Xi in May, 1939. The permanent address is 2608 McCallum Drive, Austin, Texas. CONTENTS Page A pit eo epee mt AO) AA Oe eee wn SSL WAN Oe en ET Cot a yt 2 FNC KMO We MMe NS thos tem eA ee WN emt Ubon, Baw eines ecw kuin ean 5 Ea ST RONGRDLC ONT. Seeaea a. 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ONUEe uoNi ee) ee pie one ie epee nem 10 Genuspeblietenasterey ecug eta (ie sia sC Nl Ui oa renee a pan pe it Description of Species PE ee NPN is i as EL at 12 Codropsisnsellland sip Mess ayes ee ac ee eis We ae nee 12 JP@CHNOOSS CUTEST, TWh, So Lo ncessnesconrecocnedoenedoentete coe stenereceenteleciseee 14 IE GCMWAGOSUS SAT NOTOWEMML, Te (SV. cen yarnseene seca eos state see seite sreeetecooneece 14 Sail erm asl e crCl Cike ris 1 Salsas [0 ame nC ge 16 PSMIMSITA, TOSSWCIOWMAMANC SA, TO, BID oyet ca seeeseceescerae see scec selec seeesoeeoneseemeneecnen: 17 Salen a es COb LINE NS ree sean Seal tele teh Aen its aea ne nae ee 18 SalemiamstenZeliMenhe so were cmt iain ale ee Ream ie NCL A INO Mee 19 Seillemuig, swylaitimeyyn CRYNMRON) IN, SPD. cecoscecocnecoceesseceresacee sneectnereactsesseeeee 20 (CiOMIO]O NOUS WAMTANEW Al, Wo SDo o.ccorenesecrereeteaonsenetnaeoaseo eruoseserudndoneebcecoees 21 hy mos omamby le Clnen 48 paps Seca tek tel ces UNE e yay ee oe eee 23 IP SSUCOCMAG eg, THININAME YA, Th, BID ceccoecanoncescenensoodee ate c hed dorpencceseacsoconine 24 JalOleemyroms lewllemachts ily iSO Mee 25 LetOleCIAO NS INOMCIOSMASS CAMO Ty S706. cecccesenecsnere rer nercac see soneeoetneneoeen 26 sytney wii Me yices wie Sy com vec ens Me acne Oo iy Coen Oe 26 ING Cle olite Simvvall cl e1:ce meric [0 ap eta geese minut sen mL ene 28 IB Io para hiyaeseten sien e eeyiiie tok VN PR Dm LOR A LA NaN Se ae er eal a 29 IELENSGIS <2 ie ae aae Wats een aan GR SG nd AO Rese Rings ae CU Nein Wien iets Mpeg ihl Aa Bini 33 WAN lo 1940 ei 7 een 7 ty ie 1 ) r as pial = . ‘ > t y Sie - . x 4 < 4 {i a a ak! mt , if . i . t I \ nae ‘ SOME BCHINOIDS FROM THE CRETINCEOWS Olle’ We ves By WILLIAM CLYDE IKINS ACKNOWLEDGMENTS The writer wishes to express his most sincere appreciation to all those who have made the preparation of this paper possible. He is indebted to Dr. F. L. Whitney who has given his advice, time, the use of his library, and his aid in photographing speci- mens. To Dr. F. M. Bullard, he is indebted for giving his time in reading the manuscript. To Dr. G. C. Engerrand he wishes to express apprecia- tion for encouragement and time in reading the manuscript. INTRODUCTION At the suggestion of Professor F. L. Whitney, work was begun on the study of a collection of Cretaceous echinoids which he had assembled. The collection was not made from any particular lo- cality or stratigraphic level but was obtained from various parts of the State and from several Cretaceous formations. This work is not an attempt to study the echinoids stratigraphically, but an attempt to describe the new species which were contained in the collection as well as to correct certain errors in classification which have been made and incorporated in the literature. The stratigraphic significance of echinoids in the Texas Creta- ceous would be of interest as there has been very little work done on this subject. The author hopes to be able to continue his studies of the echinoids along this line. * Presented to the Faculty of the Graduate School at the University of Texas in partial fulfillment of the requirements of the degree of Master of Arts. Austin, Texas. June, 1939. WILLIAM CLYDE IxKINs, B.S. (a3 6 BULLETIN 90 54 SVMS TIEMUNTUC DIES CRUE TIOIN'S Genus LORIOLIA Neumayr, 1881* Loriolia texana (Roemer).—This species, which was de- scribed by Roemer as a Diadema has been recently assigned by some workers to the genus Loriolia while others refer it to the genus Pseudodiadema. If the specimens of this species from the Glen Rose formation contained the apical system, this prob- lem would be easily solved. Under these circumstances other generic characters must be considered. These two genera are similar in that they both have tubercles of equal size in the ambu- lacra and interambulacra. They are also perforate and crenulate. The pores of both are uniserial and the ambulacral plates simple. According to Desor’s figures of the types of the genus Pseudo- diadema, the apical system is quite circular and not elongated on the posterior-anterior axis. Likewise the ambulacra converge to a central point and there is no noticeable separation of bivium and trivium. The figures of the type of the genus Loriolia show, as pointed out by Neumayr, that there is a noticeable separation of bivium and trivium. Hence the apical system is elongated along the pos- terior-anterior axis, This genus is characterized by a groove in the posterior portion of the discal opening. It is not known, as pointed out by Neumayr, whether there was a posterior genital plate in this groove or whether the anus pierced the apical appara- tus at this point and the posterior genital plate was absent. Of the specimens studied, none contained the apical disk, but the discal opening is elongated along the posterior-anterior axis and there appears to be a noticeable separation of bivium and trivium. The groove in the posterior portion of the opening is strongly developed. These characters point to the genus Loriolia. A literal translation of the original descriptions of these two genera now follows :— Genus LORIOLIA Neumayr, 1881 In all characteristics with the exception of apex Loriolia accords with Pseudodiadema; the summit is indeed only incompletely known, deviates essentially from all hitherto observed regular sea urchins; in the first line is itself strongly elongated so that the ambulacra do not converge in a point but a distinet separation of bivium and trivium takes place. The apical apparatus has the form of an elongated ellipse; whether the anus by itself * Neumayr, M., Ueber Loriolia, eine neue Echinidengattung, Deutsche Geol. Gesell. Zeitschr. 33, 1881. pp. 570-573.—Eds, 55 CRETACEOUS ECHINOIDS: IKINS 7 was enclosed in a circle and bordered behind by a strong bordered genital plate, or whether it pierces the apical apparatus at this point and the posterior genital plate absent, is questionable. Even so it is unknown whether the anal opening occupied the whole elongate elliptical space sur- rounded by genital and ocular plates or whether supernumerary plates ap- peared whereby Loriolia would be related to Salenia. Our information in this direction is of course still very incomplete, only so much is certain, that here is exhibited a deviation from all Pseudodiade- mas and all regular sea urchins that a separation appears necessary. We find the nearest point of comparison first in the Echinonei under which many Hyboclypeus species with highly situated anus show extraordinary conform- ity. If one, for instance, considered the summit from Hyboclypeus gibber- ulus one must concede that here only a slight difference prevails. A genus which Loriolia probably stands very near is the remarkable Heterodiadema; also, we find here, in all the characters with exception of anus and apical apparatus, near conformity with Pscudodiadema, also, we see deep notching of the posterior interambulacral zone; unfortunately nothing is known about the development of the apical appartus in Hetero- diadema, it has fallen out of all specimens and one observes only the gap which the anus and summit together produce in the corona. Jn all prob- ability Heterodiadema is, as has already been brought forth several times, nearest related to young forms of Acrosalenia, in which the anus strongly hollows out the posterior genital plate (Milnia Haime). Presumably Lor- tolia also will rank here through an association with Heterodiadema is in no ease permissible, the strong separation of bivium and trivium furnishes a very fundamental diagnostic character for Loriolia. The specimen which constitutes the type of Loriolia has been figured by Cotteau under the name Pseudodiadema Bourgueti; there arises next the question whether all the pieces of this species occurring in the Neocomian in considerable numbers belong to the new genus. Genus PSEUDODIADEMA Desor, 1858 Urchins of medium and small size. Tubercles are not inequal as in the preceding genera but of equal size on the two areas, besides crenulate and perforate, sometimes forming only two rows in the secondary series, some- times disposed in four and even six rows in the interambulacral areas. Poriferous zones simple. Radioles in the form of smooth spines well striat- ed longitudinally when one examines them with a magnifying glass. They are encountered from the lower Oolite up to the base of the Tertiary. Genus TROCHOTIARA Lambert, 1901 Trochotiara texana (Roemer).—This interesting species from the Walnut formation has been assigned by some workers to the genus Polydiadema while others assign it to the genus Trocho- tiara. These two genera are quite similar but they differ in the structure of the ambulacral plates. Tvrochotiara has ambulacral plates which are trisocieés. By this we mean that the large plate which contains the primary tubercle is made up of three parts each of which contains one pair of pores. Near the ambitus there may be a supplementary plate. Polydiadema has ambulacral plates which are quadrisociées from the apex to below the ambitus. 8 BULLETIN 90 56 This species from the Walnut formation has ambulacral plates which are trisociées; therefore, it belongs to the genus Trocho- tiara. A literal translation of the descriptions of these two genera now follows :— Genus TROCHOTIARA Lambert, 1901 Test of small size, depressed, circular, peristome quite large and apex broad and frail, pentagonal. The ambulacral majeures trisociées with sometimes a supplementary plate at the ambitus. Poriferous zones uni- geminal divided near peristome. Ambulacral tubercles not contrasting the interambulacral in principal series flanked or not with secondaries. Milliary zone broad, naked, depressed at its upper surface and ornamented with more or less abundant equal granules. The radioles are elongate, cylin- drical, and of smooth appearance. Genus POLYDIADEMA Lambert, 1888 Test subpatelliform more or less depressed with large, deepened and notched peristome. Apex large and fragile. Poriferous zones are undu- lating, unigeminal and divided toward the peristome. Majeures quadriso- ciées from the apex to below the ambitus. Tubercles well developed and a little larger at the ambitus, the interambulacra covering the major part of the plates with scrobieular circles more or less incomplete and some inequal, separated granules. Genus DIPLOPODIA McCoy, 1848 Subgenus TETRAGRAMMA Agassiz, 1840 Several species of echinoids from our Cretaceous deposits have been recently assigned by some workers to the genus Tetra- gramma while others assign them to the genus Diplopodia. An examination of the figures of the types of these two genera shows that they are both characterized by pores which are uniserial but doubled near the discal opening. The tubercles are crenulate and perforate and the ambulacral plates are compound in both. The only difference between the two is that Tetragramma has secondary rows of tubercles which are equal in size to the tuber- cles in the primary rows. By secondary rows of tubercles we mean those which do not extend all of the way from the apex to the peristome. Hence these are present only near the ambitus and they do not extend to the poles. By primary rows of tubercles we mean those which extend from the apex to the peristome. In the true Diplopodia the secondary rows of tubercles when 57 CRETACEOUS HCHINOIDS: IKINS 9 present are not equal in size to those of the primary rows. This distinction seems to be based on a character which might be debatable. Some would consider this a specific character while others would consider it important enough to establish a genus. On this basis it seems best not to class Tetragramma as an independent genus but to place it as a subgenus of Diplopodia. The following Texas species belong to the subgenus Tetra- gramma :— Tetragramma tafft (Cragin), 1893—-Comanche Peak. Tetragramma streeruwitzt (Cragin), 1893—Washita. Tetragramma texanum (Roemer) Clark, 1893—Fredericks- burg. The following Texas species belongs to the genus Diplopodia :— Diplopodia hil (Clark), 1893—Austin chalk. A literal translation of the original description of the subgenus Tetragramma now follows :— Genus TETRAGRAMMA Agassiz, 1840 The species which I arranged in this new genus are very close in many respects to the type of Diadema. They are, like them, urchins of medium aud small size having the tubercles perforate and the pores disposed in simple pairs. The buccal opening is of medium size. It is prob- able also that the ovicuctal apparatus and dental apparatus do not sensibly differ, but along with these analogies, one notices a partic- ular character which, on account of its constancy, appeared to me to necessitate a new division in the group of Diademas. This _ dis- tinetive character of the new genus comes from the distribution of the tubercles: in place of two rows of primary tubercles on each area, we have at least four on the interambulacral areas and two on the ambulacral areas. It results as a direct consequence that the Tetragrammas or urchins with four primary rows on the interambulacral area should have a more worty and rougher aspect than the true Diademas. The several rows of tubercles are almost equal. In the true Diademas on the contrary one con- stantly notes a more decided difference in the primary rows and the sec- ondary rows, some developed so that they might be the latter. These differences may appear, perhaps too insignificant to justify a gen- erie separation; nevertheless, one is forced to accord a real value, when one considers the numbers of species of true Diademas and their great uniform- ity. The tubercles carry, in all of the known species, perforated and slightly erenulated mamelons. The spines are unknown. I have taken for type of my new genus ZT. variolare (Cidarites variolaris Al. Brongniart) so frequent in the marly chalk. Genus PHYMOSOMA Haime, 1853 Cyphosoma Agassiz, 1838 (not Mannerheim, 1837) The genus Phymosoma should have priority over the genus Cyphosoma (Agassiz, 1838) for when Agassiz described the 10 BULLETIN 90 58 genus in 1838 he was not aware that Mannerheim had established the name of a genus of the Coleoptera in 1837. The following Texas species belong to the genus Phymoso- ma :— Phymosoma texanum (Roemer), 1852—Trinity and Freder- icksburg. Phymosoma mexicanum Bose, 1910—Fort Worth to Denton. Phymosoma volanum (Cragin), 1892—Washita. Genus ENALLASTER d’Orbigny, 1853 Plate 4, figs. la, 1b This genus has been listed by some workers as being synony- mous with Heteraster d’Orbigny (Plate 4, figs. 2a, 2b). Thus classification, however, could not have been based on careful ob- servation, for they are two distinct genera as pointed out by D’Orbigny in 1853. These two genera are quite similar in gen- eral appearance, but upon careful study of the unpaired ambulac- rum, one sees that the plates of Enallaster are simple while those of Heteraster are compound. Heteraster has three kinds of pores; simple internal pores which are small and aligned in a single vertical row, elongated transverse external pores, and be- tween these accessory pores which are in special plates and which alternate at irregular intervals with the other two types of pores. Enallaster has two types of pores which are placed in simple plates; very elongate, transverse pores, and small, simple pores. The inner pores of the transverse pores are not vertically aligned with the-inner pores of the small pores; therefore there is a stag- gering of the inner pores of the two types. According to D’Orbig- ny’s description of the genus as well as to his figures, these two types of pores alternate at regular intervals. It has since been proven, however, that the alternation is not regular. E. traski Whitney, for example, from the Buda limestone has two pairs of elongate pores followed by a pair of round pores; then five pairs of elongate pores followed by a pair of round ones, which are then followed by three pairs of elongate pores, before another pair of round pores occurs. 59 CRETACEOUS ECHINOIDS: IKINS 11 The peristome of Enallaster is transverse while that of Heter- aster is pentagonal. A literal translation of the original descriptions of these two genera now follows :— Genus ENALLASTER d’Orbigny, 1853 Hemipneustes Forbes, 1852 (not Agassiz, 1836) Toxaster Roemer, 1850 (not Agassiz) Characters. Genital and ocular apparatus as of the two preceding genera with this difference, at least according to the figures of Mr. Forbes in which he has in front of the four genital plates a complimentary plate. Mouth transverse, not labiate; anus oval, supramarginal Ambulacra subpetaloid, mequal. Unpaired ambulacrum very broad, placed in a groove, entirely unlike others: the two branches are composed of pores very unlike those of the others; one sees in a regular alternative succession a pair of very elongate pores, transverse, and a pair of simple pores, very small, and that on all the broad part of the ambulacrum: the rest is provided with equal pores. The ambulacral pairs are superficial, very inequal in length, formed of inequal zones, the broader behind. No fascioles. Tubercles inequal, rare, crenulate, and scrobiculate. Shell thin, cordiform, depressed. Relations and differences. With all of the principal characters of Echinospatagus and Heteraster, this genus is distinguished only by its un- paired ambulacrum. This instead of being formed of equal successive pores as with the first, or of three sorts of pores on three parallel lines, like the second, has pores of very different form alternating with one another on each of the two poriferous zones. It is one of the most singular conforma- tion of pores which we know among the echinoids. Genus HETERASTER d’Orbigny, 1853 Spatangus (in part) Brongniart Toxaster (in part) Agassiz, 1840 Characters. Genital and ocular apparatus as among the other genera of the family and especially as among the Echinospatagus. Mouth pentag- onal, not labiate. Anus oval, supramarginal. Subpetaloid ambulacra in- equal. The unpaired ambulacrum placed in a slight groove composed of three kinds of pores; of simple internal pores, small; of elongated, trans- verse external pores, and between these accessory pores interculated and alternating witb the others at irregular distances and depending on special interculated plates which unite these internal pores and the external ones. The ambulacral pairs are almost superficial or slightly excavated, very in- equal, the anterior one the longer, all subpetaloid. They are formed of inequal pore zones the posterior one large; the other anterior narrow. In each zone the anterior range is formed of simple pores. The external range of much larger pores generally transverse. Outside of the petaloid parts of the ambulacra there are only small simple pores. There is no fasciole. Tubercles rare, separated, inequal, crenulate, and often scrobi- culate. Shell thin, cordiform, oval, and depressed. Relations and differences. With ali of the principal external characters of Hchinospatagus, those which distinguish it are three sorts of pores in place of two in the unpaired ambulacrum, that is to say of internal and external pores in each zone, and of intermediate pores interculated be- tween them and assigned to special plates placed between the ordinary plates. 12 BULLETIN 90 60 The only two species known are from the upper Urgonian region of the 17th Neocomian stage. Both were described by Mr. Agassiz as Towxaster. It is quite singular that this author with all that he had to say about the two species did not notice the pores so different in the unpaired ambulacrum. Therefore, the following Texas species belong to the genus Enallaster :— Enallaster texanus (Roemer), 1852—Fredericksburg and Washita. Enallaster obliquatus Clark, 1915—Glen Rose. Enallaster texasus d’Orbigny, 1853—Fredericksburg. Enallaster bravoensis Bose, 1910—Washita. Enallaster wenoensis Adkins, 1920—Weno and Pawpaw. Enallaster traski Whitney, 1916—Upper Buda. Enallaster adkinsi Lambert, 1927—-Duck Creek. Encallaster inflatus Cragin, 1892—Grayson. DE SERMMMON OL SH nrs Order CENTRECHINOIDA Jackson Suborder ALODONTA Jackson Family CENTRECHINIDAE Jackson Genus CODIOPSIS Agassiz, 1840 Codiopsis sellardsi, n. sp. Pie il, mes, IA, ilo, Le Description —The test is medium in size, elevated and globose. When viewed from above, it is subpentagonal in outline, the am- bulacral areas being at the angles and the interambulacral areas forming the sides. The superior surface is elevated and abruptly rounded whereas the inferior surface rounds gently from the am- bitus to the peristome. The ambulacral areas are narrow being only about one-third of the width of the interambulacral areas. They are straight and increase in width from a point at the apical disk to a maximum width of about 5 mm. at the ambitus. Only fine granules are scattered above the ambitus. Reaching over about two-thirds of the distance from the peristome to the ambitus, there are two alternating rows, of about six each, of round, noncrenulate, im- perforate, mamillated tubercles. Two rows of alternating gran- 61 CRETACEOUS ECHINOIDS: IKINS 13 ules are situated adradially from the tubercles. The pores above the ambitus are round and are located in a slight depression. They are arranged in groups of three to each ambulacral plate. The pore pairs increase below the ambitus until there are four rows of pores at the peristome. Between each pair of pores in this region there is a granule. The interambulacral areas are wide and depressed. The sur- face above the ambitus is ornamented with minute granules ar- ranged in such a manner as to form fine longitudinal lines. Be- low the ambitus, there are four rows of noncrenulate, imperforate, mamillated tubercles which diverge from the peristome, two rows being in either half of the area. In the adradial rows there are from seven to eight tubercles, while in the median rows there are from three to four tubercles. The peristome is small, without notches, and is elongate and oval along the lateral axis. The specimen has been slightly crushed, but the peristome was undoubtedly oval before the crush- ing occurred. The apical system is small and is composed of five genital and five ocular plates. The right anterior genital is larger than the others and contains the madreporite which is irregular in shape and occupies most of the plate. The genital plates are perforated by large round pores which are located on the outer margins of the plates. The ocular plates are irregular in shape and are al- most bell-shaped. Perforations on the outer ends of the plates are not to be observed. The periproct is almost circular in shape. Related forms.—This species closely resembles Codiopsis tex- ana Whitney in proportions and in general appearance, but it may be distinguished by its elongate, oval peristome and its more globular form. The tubercles of this species do not seem to be so well developed. Dimensions.—Diameter at ambitus, 33 mm.; height, 28 mm.; apical disk, 11 mm.; peristome, about 10 mm. along the posterior- anterior axis and about 15 mm. along the lateral axis. Occurrence.—Stratigraphic level not known—probably upper Fredericksburg—found with other Fredericksburg fossils. Locality —Seven Mile Mesa near Fort Stockton, Texas. 14 BULLETIN 90 62 Genus PEDINOPSIS Cotteau, 1863 Pedinopsis engerrandi, n. sp. Plate 1, figs. 2a, 2b, 2e Description.—Test medium size, circular in outline, subconi- cal, sides inflated; adactinal surface flat; abactinal surface con- cave. Ambulacra straight and quite narrow being I mm, at the apical disk, 4 mm. at the ambitus, and 1.5 mm. at the peristome. Sur- face crnamented with six rows of primary tubercles at the am- bitus, the two marginal ones being complete, the four inner ones incomplete. The tubercles are perforate and finely crenulate. Pores biserial, small, and round; ambulacral plates compound. The interambulacral areas are wider than the ambulacral areas and they widen from 1.5 mm. in the plocogenous zone to 8.2 mm. in the median zone, and 2.5 mm. at the peristome. Surface orna- mented with twelve rows of perforate, finely crenulate tubercles at the ambitus, which become reduced toward the peristome. Tu- bercles equal in size with those of the ambulacra. Small granules are scattered over the ambulacra and interambulacra. The actinal surface is in a poor state of preservation, but the peristome is about 8 mm. in diameter and is marked by ten dis- tinct incisions in the interambulacra. The apical system is not preserved, but 1t was apparently about 4 mm, in diameter. Related forms.—This species is quite similar to Pedinopsis yarborough, n. sp., but the abactinal surface of this species is concave rather than convex. It has a slight resemblance to Pedinopsis desori Cotteau from the Cenomanian of Europe, but the abactinal surface of this spe- cies is concave while that of P. desori is convex and elevated. Dimensions.—Diameter at ambitus, 21 mm.; height, 11.5 mm.; apical disk, 4 mm.; peristome, 8 mm. Occurrence.—Lower clays of Walnut formation. Locality.—Outcrop on Anderson Mill road just west of Mar- shall Ford Dam road, Travis County, Texas. Pedinopsis yarboroughi, n. sp. Plate 1, figs. 3a, 3b, 3¢ Description.—The test is circular in ambital outline, globose, 63 CRETACEOUS ECHINOIDS: IKINS 15 sides inflated; abactinal surface gently convex; adactinal surface almost flat with a slight concavity near the peristome. The ambulacral areas are narrow and straight. They widen gently from 1 mm. at the apical disk to 5 mm. at the ambitus, then narrow down to 3 mm. at the peristome. The surface is ornamented with six rows of tubercles at the ambitus. The outer rows are complete and reach from the apical disk to the peris- tome while the inner rows do not extend to the poles. The tu- bercles are finely crenulate and perforate. Granules are quite numerous between the tubercles. The plates are compound. The pores are small and biserial. The interambulacral areas are broader than the ambulacral areas and are composed of two rows of alternating plates. There are fourteen rows of tubercles at the ambitus, which become re- duced to four at the peristome. The tubercles are finely crenu- late, perforate, and are about the same size as those of the ambu- lacral areas. Small granules are scattered over the plates. The apical disk is not present, but it must have been about 4.5 mm. in diameter. The peristome is round and is marked by ten distinct incisions in the interambulacra. ; Related forms.—This species slightly resembles Pedinopsis pondi Clark in general appearance, but the sides are more in- flated. There are only fourteen tubercles in the interambulacral area at the ambitus instead of eighteen. It differs from Pedinopsis engerrandi, n. sp. in that it is more elevated and globose and that the abactinal surface is gently con- vex instead of concave. Dimensions.—Diameter at ambitus, 24 mm.; height, 15 mm.; apical disk, 4.5 mm.; peristome, 9 mm. Occurrence.—Lower clays of Walnut formation. Locality.—Outcrop of lower Walnut on the north side of the road at Dies ranch on the Pond Springs School-Anderson Mill road, Travis County, Texas. 16 BULLETIN 90 64. Suborder STIRODONTA Jackson Family SALENIIDAE Desor Genus SALENIA Gray, 1835 Salenia leanderensis, n. sp. Plate 1, figs. 4a, 4b, 4e Description —The test is circular in ambital outline, sides slightly inflated; abactinal surface gently and regularly rounded ; adactinal surface practically flat. The ambulacra are quite straight and wide. They are about one-half the width of the interambulacra at the ambitus and they widen only slightly between the apical disk and the peristome. The surface is ornamented with two alternating rows of about twelve imperforate, crenulate, mamillated tubercles. There are no granules between the tubercles. The pores are round, unigem- inal, and become irregular as well as crowded upon approaching the peristome. The interambulacra are composed of two rows of alternating plates, five to a row. Each plate is ornamented with a scrobicu- late boss which bears an imperforate, crenulate mamelon. Gran- ules are arranged such that there is a granule in the upper and lower adradial corners as well as five on the medial margin of each plate. The peristome is decagonal and is quite large, being over one- half the diameter of the shell. The ambulacral and interambu- lacral lips are practically equal. The branchial incisions are well developed. The apical disk is circular in outline and is raised above the surface of the shell. It is composed of five ocular and five gent- tal plates as well as the suranal plate. There appears to be no ornamentation on the plates. The oculars are triangular in shape. The genitals are each perforated by a pore which is located near the center of the plate. The incision in the right anterior genital plate extends from the genital pore to the margin of the plate so that it is difficult to locate the first pore between the ocular and genital plates. The periproct is slightly deltoid but rounded at the angles. Related forms.—This species has no doubt been misidentified as Salenia mexicana Schliter, but it may be readily distinguished 65 GrRETACEOUS EcHINOIDS: IKINS 17 by its size, the number of ambulacral tubercles, about twelve 1n- stead of eighteen to twenty, and the shape of the shell. This species has only five interambulacral plates while S. mexicana usually has six. This species bears a resemblance to Salemia philipse Whitney from the Glen Rose formation in general appearance, but it has about twelve ambulacral tubercles instead of five. It has five interambulacral plates in each row instead of four. The apical system is circular and not pentagonal. Dimensions —Diameter at ambitus, 9 mm.; height, 5 mm.; apical disk, 6 mm. ; peristome, 5 mm. Occurrence.—Upper_clays of Walnut formation. Locality Borrow pit on west side of road, 1 mile north of Leander, Texas. Salenia pseudowhitneyi, n. sp. Plate 1, figs. 5a, 5b, 5¢ Description—The test is medium in size, circular in ambital outline; abactinal surface depressed convex ; adactinal surface slightly concave, sides inflated and regularly curved. The ambulacral areas are narrow and slightly flexuous. The surface is ornamented with two rows of about nineteen alter- nating circular, imperforate, mamillated tubercles. Between each pair of tubercles there is a pair of granules. The pores are uni- serial, round, and are slightly crowded but quite regular upon reaching the peristome. The interambulacral areas are wide and consist of two rows of seven broad, alternating plates. Each plate contains a large, scrobiculate, crenulate boss which bears an imperforate mamelon. Granules are so arranged in the middle of the area that there are two rows of large granules with two rows of smaller granules between them. There is also a large granule in the upper and lower adradial corners of each plate. The peristome is large, circular, decagonal, and contains strongly developed branchial incisions. The apical system is large, subpentagonal, and is composed of five ocular and five genital plates as well as the suranal plate. The ocular plates are small, subtrigonal, and their basal margins 18 BULLETIN 90 66 are extended with respect to the basal margins of the genitals. The genitals are broad and their basal margins are not pointed but gently rounded. Their shape along with the shape of the oculars gives the outer margin of the apical disk a scalloped ap- pearance and disrupts a true pentagon. The incision in the right anterior genital plate is crescent-shaped and extends from the genital pore to the margin of the plate. Related forms.—This species is very similar to Salenia whit- neyt Cannon in many respects, but it may be distinguished by the shape of the apical system which is not pentagonal but subpen- tagonal and scalloped on the outer margin. ‘The genitals of this species are not depressed with respect to the oculars so that when viewed laterally the base of the apical disk is a straight line in- stead of a zigzag line. The genital plates are broader and are not pointed at the base but gently rounded. Dimensions.—Diameter at ambitus, 17.1 mm.; height, 10.5 mm.; apical disk, rr mm.; peristome, 7.5 mm. Occurrence.—Anacacho formation. Locality.—Lower chalky marl at King’s Water Hole on Hondo River, 2 miles north of Hondo, Texas. Salenia scotti, n. sp. Plate 2, figs. la, 1b, 1c Description.—The test is subcircular in outline at the ambitus ; abactinal surface greatly elevated, the sides slightly inflated; adactinal surface flat. The ambulacral areas are straight and narrow, slightly widen- ing from 1.5 mm. at the apical disk to 2 mm. at the peristome. The surface is ornamented with two rows of about nineteen al- ternating tubercles which are imperforate, mamillated, and cir- cular in outline. Situated between these are small granules which become quite noticeable opposite the second ambulacral tubercle above the peristome. The pores are round, some being elongated horizontally, uniserial, and become more numerous as well as irregular upon approaching the peristome. The interambulacral areas are wider than the ambulacral be- ing 4 mm. wide in the plocogenous zone, 6.5 mm. in the median zone, and 4 mm. at the peristome. They consist of two rows of large alternating plates, six being present in each row. The 67 CRETACEOUS HcHINOIDS: IKINS 19 primary tubercles decrease in size from the abactinal surface te the peristome where they are about the same size as the tubercles within the ambulacral areas. Each plate contains a large, scro- biculate, crenulated boss which bears an imperforate mamelon. The granules are so arranged on the margins of plates that there are two in the upper adradial corner and only one on the lower adradial corner, while on the medial margins of the plates there are four. Milliaries occur between the granules on the medial margins of the plates. The peristome is large, about one-half the diameter of the test, and is circular in shape. The basicoronal plates bear ten greatly developed incisions which divide the peristome into ten almost equal parts. The apical system is large, circular, and is composed of five ocular and five genital plates and the suranal plate which is lo- cated in the center of the system by the periproct. There are radiating furrows which extend out from the suranal plate toward interambulacra 1, 2, and 3. Between these furrows are two delta-shaped depressions which with the furrows give the apical disk, a characteristic ornamentation. The incision in the right anterior genital plate is irregular in shape. The periproct is elevated and triangular or deltoid in shape. Related forms.—This species is somewhat similar to Salenia mexicana Schlitter in that it has about nineteen ambulacral tu- bercles, but it is much more elevated. The periproct of this species is much more prominent and the ornamentation of the apical disk is entirely different. This species differs from S. volana Whitney in that it has about nineteen ambulacral tubercles where- as S. volana has about fifteen to seventeen. This species is also much more elevated. Dimensions.—Diameter at ambitus, 16 mm.; height, 12 mm. ; apical disk, 9.5 mm.; peristome, 8 mm. Occurrence.—Upper Salenia level of the Goodland formation. Locality.—Unknown. Salenia stenzeli, n. sp. Plate 2, figs. 2a, 2b, 2c Description.—The test is circular in outline at the ambitus ; abactinal surface only slightly convex; sides inflated; adactinal 20 BULLETIN 90 68 surface almost flat and only slightly concave. The ambulacral areas are flexuous and quite narrow, slightly widening from 1 mm. at the apical disk to about 2 mm. at the peristome. The surface is ornamented with two rows of about sixteen alternating tubercles which are imperforate, mamillated, and circular in outline. Small granules are situated between these tubercles. The pores are round, uniserial, and become ir- regular as well as more numerous upon reaching the peristome. The interambulacral areas are wider than the ambulacral areas being 4 mm. wide in the plocogenous zone, 6.5 mm. in the median zone, and 3 mm. at the peristome. They consist of two rows of six alternating plates each of which is ornamented with a scrobi- culate, crenulated boss upon which rests an imperforate mamelon. The peristome is small, about one-third of the diameter of the test, and is circular in outline. The incisions in the basicoronal plates seem to be only slightly developed. The apical system is large, about two-thirds of the diameter of the test, and is circular in outline. It is composed of five ocu- lar and five genital plates as well as the suranal plate which is lc- cated in the center of the system. The incision in the right an- terior genital plate is crescent-shaped. The periproct is circu- lar in shape and is only slightly elevated. Related forms.—This species slightly resembles Salema neo- comiensis Cotteau from the Neocomian of Europe, but it has six interambulacral plates and about sixteen ambulacral tubercles, whereas S. neocomiensis has only five interambulacral plates and about eighteen ambulacral tubercles. It may be distinguished from Salenia mexicana Schlitter by its general outline. The shell is inflated and the sides round off to an almost flat abactinal surface. Dimensions.—Diameter at ambitus, 14 mm.; height, 9 mm. ; apical disk, 9.5 mm.; peristome, 5.7 mm. Occurrence.—In the Exogyra whitney: shale of the Grayson formation. Locality—C. Muleros, opposite the smelter, El Paso, Texas. Salenia whitneyi Cannon, n. sp. Plate PNAS, BA, Bo, SC Description.—Test medium in size, elevated, the aboral surface depressed, convex, the adoral surface nearly flat, slightly concave, the sides inflated and. regularly curved. 69: CRETACEOUS HCHINOIDS: IKINS ; 91 The apical system is pentagonal, depressed, conical. The ocular plates are small, subtrigonal, t..eir basal margins continuous with the basal mar- gins of the genitals forming the sides of the pentagonal outline. The gen- ital plates are elongate, their basal extremities being tie apices of the pentagon. ‘Two small ridges ornament the margins of the genitals; the oculars are without ornamenta.ion. The madreporite is narrow, elongate, extending from the genital pore to the margin of the plate. Le periproet is subtrigonal, bordered about equally by the suranal, the posterior genital, and ihe rig.t posterior genital plates. YLe ambulacra are narrow and flexuous. Tke nonporiferous areas are provided with two rows of rounded, mamillated, alternating tubercles, 22-24 in each row, between each pair of which is a pair of prominent granules. ''ne pores are circular, arranged in unigeminal series, those nearest the embitus being the largest. Tne interambulacra are broad and supplied with two rows of mamillated primary tubercles, 6-7 in a row, two rows of large granules in zigzag alignment, two rows of smaller granules between the larger, and many minute granules encircling the others. T.e peristome is large, depressed, decagonal, the branchial notches strong. Young foims lack the regularity of arrangement of granules in the inter- ambulacra, are often relatively more depressed, and have the pentagonal outline of the apical system destroyed by protruding ocular plates. Dimensions.—Height, 16 mm.; diameter, 23 mm.; diameter of apical system, 15 mm. Remarks.—-This species is somewhat similar to Salenta bellula Clark, but is larger, has no ornamentation on the apical disk, has a subtrigonal peri- proet, and has more primary tubercles on both the ambulacra and inter- ambulaera. Occurrence.—Basal chalky marl at King’s Water Hole on Hondo River about 2 miles north of Hondo, Texas. Genus GONIOPHORUS Agassiz, 1838 Goniophorus whitneyi, n. sp. Plate 2, figs. 4a, 4b, 4c Description—The test is circular in outline, sides slightly in- flated ; abactinal surface slightly rounded but pointed at the apex ; adactinal surface gently concave. The ambulacral areas are slightly flexuous and lanceolate, changing only slightly in width between the apical disk and peri- stome. The surface is ornamented with two rows of about fifteen alternating, imperforate tubercles. Between the tubercles are two rows of alternating granules. The poriferous zones are com- posed of about twenty-nine circular, alternating, uniserial pores which become slightly irregular upon reaching the peristome. The interambulacral areas are broader than the ambulacral areas being 2.5 mm. wide in the plocogenous zone, 4 mm. at the ambitus, and 1 mm. at the peristome. They consist of two alter- nating rows of seven plates each. Each plate contains a crenu- 99 RuatAmMN 90 70 lated, scrohiculate boss which bears a spherical imperforate mame- lon. The plates are largest at the ambitus and they diminish in size toward the poles. Granules are arranged on the margins of the plates such that there is a granule in the upper and lower adradial corners as well as in the upper and lower medial cor- ners. Small bands of milliaries are located all along the margins of the plates. The peristome is small, only about one-third of the diameter of the test and is circular in shape. The incisions in the basicor- onal plates are but slightly developed. The apical system is quite large, pentagonal, and composed of five ocular and five genital plates as well as the suranal plate which is located in the center of the system. The posterior geni- tal is so arranged that it is not in contact with either of the lateral genitals due to the position of the periproct, hence oculars I and V are insert whereas II, III, and IV are excert. There are two radiating ridges which radiate from the apex of the suranal plate toward the center of the right and left anterior genital plates. On each genital plate there are two elevated granules, one being on either side of the pore. The incision in the right anterior genital plate is deltoid in shape. The periproct is large and circular be- ing slightly elongated laterally. Related forms——In general appearance this species slightly re- sembles Goniophorus scotti Lambert, but it is over twice as large in size. The apical disk is markedly different in ornamentation. This species has seven plates in the interambulacral areas where- as G. scotti has only six. Likewise this species has about fifteen ambulacral tubercles while G. scotit has only about ten. This species differs from Goniophorus lunulatus Agassiz, the genotype, from the Cenomanian of Le Havre, in having seven interambulacral plates as compared to six. ‘The periproct of this species is more nearly round and the ornamentation of the apical disk is entirely different. The subtubercular pores of this spe- cies are less prominent. Dimensions.—Diameter at ambitus, 9.5 mm.; height, 6.5 mm. ; apical disk, 5 mm.; peristome, 3 mm, 71 Cremacrous HaHtNoms: ITKINS YQ Occurrence.—Del Rio formation. About ten feet helow the Buda-Del Rio contact. Locality.—Fifteen hundredths mile east of the road at a point .4 mi. south of the Marathon-Alpine-Terlineua road fork. Buck Fill quadrangle, Brewster County, Texas. Family PHYMOSOMATIDAE Meissner Genus PHYMOSOMA Haime,. 18538 Phymosoma byheei, n. sp. Plate 2. figs. 5a, 5b, 5e Description.—Test subpentagonal, sides inflated and regularly curved; adactinal and abactinal surfaces almost flat. The ambulacra are straight and broad. They widen gently row down to 5 mm. at the-peristome. The area is composed ot two rows of alternating, compound plates, twelve or thirteen to a row. Each plate is ornamented with a scrohiculate, crenulate boss which bears a spherical, imperforate mamelon, Grannies are scattered over the medial and adradial margins of the plates. The poriferous zones are broad and straight. Ahove the ambitius the pores are biserial, while below the ambitus they are uniserial, but upon approaching the peristome they hecome irregular and crowded, The interambulacra are narrow and are composed of two rows of alternating plates, twelve to a row. Each plate is ornamented with a large scrobiculate, crenulate boss which hears an imner- forate mamelon. These are located near the medial margin of the plate. Near the adradial margin of each plate there is a mamelonated granule. Hence there are only two rows ot pri- mary tubercles in the area. Granules are scattered on the me- dial and adradial margins of the plates. The peristome is large, depressed. and marked hy ten stronely developed branchial incisions. The ambulacral lips are broader than those of the interambulacra. The discal opening is large and pentagonal. The angles occu at the medial suture of the interambulacral areas. Related forms.—This species has no doubt heen misidentified as Diplopodia hilli (Clark) which also occurs in the Austin challs, Clark assigned his species to the genus Cyphosoma hut according to his figures as well as to his description, the tubercles of his 24 BULLETIN 90 ee) species are perforate. Hence it does not belong to this genus. This species is characterized by imperforate tubercles which are crenulate as well as scrobiculate. Dimensions.—Diameter at ambitus, 31 mm.; height, 13 mm. ; apical opening, 11.5 mm.; peristome, 13.5 mm. Occurrence.—Austin chalk, Locality—One and one-half mile west of Dessau, Travis Coun- ty, Texas. Genus PSEUDODIADEMA Desor, 1858 Pseudodiadema whitneyi, n. sp. Plate 3, figs. la, 1b, le Description—Test circular in ambital outline, sides inflated and regularly curved; adactinal surface almost flat but slightly depressed near the peristome ; abactinal surface depressed, convex. The ambulacra are straight and narrow. They widen gently from I mm. at the discal opening to 2.5 mm. at the ambitus, then narrow down to 1.5 mm. at the peristome. They are composed of two rows of alternating plates. Each large plate consists of three parts each of which contains a pair of pores. The surface is ornamented with two rows of primary tubercles, about ten to each row. The tubercles are scrobiculate, crenulate, and per- forate. Granules are scattered on the margins of the plates. The poriferous zones are wide. The pores are round, uniserial, and they become irregular upon approaching the peristome. The interambulacra are about 3 mm. wide at the discal open- ing, 5.5 mm. at the ambitus, and 2.5 mm. at the peristome. They are composed of two rows of alternating plates, about eleven to each row. Each plate is ornamented with a scrobiculate, crenu- late boss which bears a spherical, perforate mamelon, Granules are scattered on the outer margins of the plates. The discal opening is large and subpentagonal to oval.. The margin is smooth and there is no posterior groove. The peristome is small, decagonal, and is marked by ten moder- ately developed branchial incisions. The lips of the interambu- lacra are about three times as wide as those of the ambulacra. Related forms.—This species does not appear to be closely re- lated to any yet described. It may be readily distinguished from Trochotiara texana (Roemer) which also occurs in the same 73 CRETACEOUS ECHINOIDS: IKINS 25 formation by its subpentagonal to oval discal opening which has no posterior notch and by the structure of the ambulacral plates. Dimensions.—Diameter at ambitus, 13 mm.; height, 6 mm.; discal opening, 6 mm.; peristome, 6 min. Occurrence.— Upper clays of the Walnut formation. Locality —Rorrow pit on west side of road 1 mile north of Leander, Texas. Order EXOCYCLOIDA Jackson Suborder HOLECTYPINA Gregory Family PYGASTERIDAE Gregory Genus HOLECTYPUS Desor, 1842 Holectypus buliardi, n. sp. Plate 3, figs. 2a, 2b, 2c Description.—The test is circular in ambital outline; ambitus sharp; abactinal surface elevated and regularly curved; adactinal surface almost flat near ambitus, but quite concave in the vicinity of the peristome. The ambulacra are narrow and lanceolate. They widen gently from a point at the apical disk to 2 mm. at the ambitus then de- crease in wicth upon approaching the peristome. The poriferous zones are narrow, the pores small, round, and uniserial. There are four vertical rows of tubercles in the area at the ambitus, which become reduced toward the poles. The irterambulacra are about twice the width of the ambu- lacre at the ambitus. The plates are long, narrow; each orna- mented with a horizontal row of tubercles, about three to a row at the ambitus, but fewer above and below. ‘The tubercles are small, perforate and finely crenulate. The peristome is small and slightly decagonal; ambulacral and interambulacral lips practically equal. The apical system is small and elevated slightly above the sur- face cf the shell, It is composed of five ocular and five genital plates. The genitels are long, pointed, and are perforated near their outer margins. The right anterior genital is enlarged and modified to form the madreporite which extends to the center of the system. The oculars are quite indistinct but triangular in shape. 26 BULLETIN 90 74 The perrproct is quite large and is situated about midway be- vween the peristome and ambitus. Both ends of the periproct are pomrved but the amverior end is very slightly rounded in some Specimens. Related jorms.—Vhis species has a slight resemblance te Holec- iypus hondoénsis Cannon from the Anacacho formation, but it uy be readily distinguished by its circular ambital outline and the Shape of the periproct. Dimensions. —Diameter at ambitus, 9 mm.; height 4.7 mm. ; peristome, 2 wun.; length of periproct, 2 mm.; width of same 1.2 rly. Occurrence.—Ausun tormation, About the Terebratulina guadalupe zone. Locality.—On Little Walnut Creek south of old iron bridge on road trom Austin to Sprinkle, Texas. Hulectypus honaveusis Cannon, n, sp. Plate 3, figs, 3a, 3b, 3c Desceription.—Test sub-pentagonal almost cireular, subeonieal, adoral surface flat, depressed at the peristome, sides regularly curved, ambitus uear the adoral surface. The apical disk is small, pentagonal (?). The details are not distin- guishable on our specimen. The ambulavral areas are straight, narrow, widest at the ambitus. The primary plates bear two pairs of pores on one primary tubercle. Hach tubercle is in a relatively wide areola which in turn is surrounded by fine | granules. he pores are small, circular and unigeminat. The interambulacral areas are about twice the width of the ambulacral. The primary plates are long, narrow, and supplied with 3 rows of primary tubercles. Each tubercle has a wide areola which in turn is surrounded by fine granules. The peristome is small, depressed, and having shght branchial imeisions which give it a decagonal margin. 7 The periproct is oval, being about twice as long as wide, situated on the flat adoral surface about equally distant from peristome and ambitus. Dimensions —Height, 8 mm.; diameter, 13 mm. Remarks.—This species bears certain resemblances to Holectypus planatus Roemer, but differs by having only two rows of tubercles in the ambulacral areas, Six in the interambulacral areas, and having a much smaller periproct. Occurrence.—Basal chalky marl at King’s Water Hole on Hondo River about 2 miles north of Hondo, Texas. Suborder SPATANGINA Jackson Tribe CASSIDULOIDEA, Duncan Family ECHINONEIDAE Wright Subfamily ECHINONEINAE Desor Genus PYRINA Desmoulins, 1835 Pyrina whitney, n. sp. Plate 3, figs. 4a, 4b, 4c Descripiion.—The test is circular in outline at the ambitus; 75 CRETACEOUS ECHINOIDS: IKINS 27 abactinal surface inflated and gently rounded; adactinal surface concave. The ambulacral areas are straight, lanceolate, slightly widen- ing from a point at the apical disk to 6 mm. at the ambitus, then narrowing down to 1.5 mm. at the peristome. The poriferous zones are straight and are composed of about one hundred and twenty-four rounded uniserial pores. The interambulacral areas are wider than the ambulacral areas being 2 mm. wide in the plocogenous zone, about 15 mm. at the ambitus, then narrowing down to 2 mm. at the peristome. Both the ambulacral and interambulacral areas bear, numerous pri- mary tubercles which are in slight depressions. Very fine gran- ules are disseminated between the primary tubercles. The peristome is circular being somewhat elongated on the posterior-anterior axis and situated in the middle of the base. The apical system is small being composed of four genital and five ocular plates. The right anterior genital plate has been modi- fied to form the madreporitic opening. The two posterior oculars are in contact with each other but the anterior and lateral oculars are between the genitals. The periproct is oval and is located on the lower portion of the posterior margin, the upper portion of the periproct being at about one-half of the height of the shell. Related Forms.—This species presents a slight similarity to Pyrina parryi Hall in general appearance but it is more elevated, circular in outline and is more convex on the actinal surface. The shape of the peristome is more circular and the periproct is located lower on the posterior surface. It may be distinguished from Pyrina inaudita Bose by the fact that the periproct is much lower. It is more circular in outline than Pyrina clarki Bose. Dimensions.—Length, 35 mm.; height, 20 mm. ; width, 34 mun. ; height of periproct, 7 mm.; width of same, 4 mm. Occurrence.—Georgetown formation. Locality.—East slope of Mount Bonnell west of Austin, ‘Vexas. 28 BULLETIN 90 76 Subfamily ECHINOBRISSINAE Duncan Genus NUCLSOLITES Lamarck, 1801 Nucleolites wilderz, n. sp. Plate 3, figs. 5a, 5b, 5c Description —Test medium in size, subquadrate ; adactinal sur- face slightly concave, abactinal surface depressed, convex. The greatest width of the shell is just anterior to the anal opening. The ambulacral areas are short and lanceolate. They extend around to and are well developed in the region of the. peristome. The poriferous zones on the upper surface are subpetaloid. The pores of the inner row are round whereas those of the outer row are slightly elongate and obliquely placed. The interambulacral areas are broad and bear numerous small mamillated tubercles around which are located many minute granules. They widen gradually in size from the apical system until they reach the peristome where they end in a distinct lobe. The apical system is small and is situated about one-third of the length of the shell from the anterior end. Four of the genital plates are pierced by large genital openings. The madreporite is large and centrally located. The periproct is supramarginal, elongate, narrow, and is situ- ated in the anterior end of a shallow groove. The anal sulcus almost totally disappears before reaching the posterior margin. The peristome is small, pentagonal in shape, and is located slightly anterior of the center of the base. Extending posteriorly from the peristome to the margin of the shell is a broad band which is free from tubercles. Related forms.—This species reminds one of Echinobrissus texanus Clark when viewed from above or below, but when viewed from the side it is unlike any other whose description has fallen under my observation. It is characterized by a long flat ridge on top and is not pointed as most other species. Dimensions.—Length, 28 mm.; width, 24.5 mm. ; height 13 mm. Occurrence.—Austin formation—Spondylus guadalupe zone. Locality Travis Heights, Austin, Texas. WG CRETACEOUS ECHINOIDS: IkKINS 29 BIBLIOGRAPHY Adkins, W. S., and Winton, W. M. Paleontological Correla ion of the Fredericksburg and Washita Forma- tions in North Teaas, Univ. of Tex. Bull. 1945, 1919. Adkins, W. S., Handiook of Texas Cretaceous Fossils. Univ. of Texas. Bull. 2838, 1928. Adkins, W. §S, Texas Comanchean Echinoids of the Genus Macraster. Univ. of Tex. Bull. 3001, 1930. Agassiz, L. Description des Echinodermes Fossiles de la Suisse, 1839-1840. d’Archaic, A. and Haime, J. Description des Anima Fossiles du Groupe Nigam alee ae de L’Inde, Paris, 1853. Bather, F. A., Gregory, J. W., and Goodrich, E. S. A Treatise on Zoology, Pt. 3, The Echinodermata, London, 1900. Bose, E. Instituto Geoldgico de México, Boletin Nim. 25, 1910. Boyle, C. B. A Catalogue and Bibliography of Norih American Mesozoic Inverte- brata. U.S. Geol. Survey, Bull. 102, 1893. Cannon, R, L. The Fauna of the Escondido Formation. Thesis M.A., Univ. of Tex. Library, 1922 Clark, W. B. The Mesozoic Echinodermata of the United States. U.S. Geol. Sur- vey, Bull. 97, 1893. Clark, W. B., and Twitchell, M. W. The Mesozoic and Comocate Echinodermata of Te United States. U. S. Geol. Survey, Monograph, vol. LIV, 1915. Conrad, T. A. Report U. S. and Mexican Bound. Survey, vol. 1, pt. 2, 1857. Cotteau, G. Etudes sur les Echinides fossiles du Départment de 1’ Yonne, 1857-1878. Cotteau, G. Note sur quelques Echinides du terrain Crétacé du Mexique, Bull. Eco. Geol. de France, 3 serie, t. XVII, 1890. Cotteau, Peron, and Gauthier Echinides fosstles de |’ Algérie, Paris, 1876-1891. Cragin, F. W. A Contribution to the Paleontology of the Texas Cretaceous. Geol. Survey of Texas, Fourth Ann. Rept., 1893. 30 BULLETIN 90 78 Credner, G. R. Ceratites fastigatus und Saienia texana. Zeitschr. fiir gesam. Natur- wiss, vol. 46, 1875. Descor, H. Synopsis des Wehinides fossiles, Paris et Wiespade, 1858. Dunean, P, M. P Kevision of genera and great growps of tre Hchinoidea. Linn. Soe. Jour. Zoology, vol. 23, 1891. Giebei, C. G. ; Beitrag sur Paleontology aes Texanischen Kreiaegebirges. Naturwiss. Ver. in Haile sahresb. fiir 1852, 1853. Hawkins, H. LL. Some Cretaceous Heninoias from Jamaica. Geol. Mag., vol. 60, No. 5, 1923. Hawkins, H. L. Netes on a new coliection of fossil Hchinoidea from Jamaica. Geol. Mag., 61, No. 7, 1924. Jackson, KR, T. Phylogeny cf the Hehini. Mem. Bost. Soe. Nat. History, 1912. Jackson, K, ¥. Fossil Hchint of tie West indies. Carnegie institution of Washing- ton, Publication No. 306, 1922. Kew, W.S. W. Cretaceous and Cenozoic HeninotGea of the Pacific Coast of North America, Univ. of California Dept. of Geol. Bull., vol. 12, No. 2, 1920. Lambert, J. Bull. Geol. Soe. France, 1902-1905. Lambert, J.. and Thiéry, &. Hissar de Nomenclature Kaisonnée des Hciviides. Chaumont, 1909-1925. Morton, S. G. - Synopsis of tre organic remains of tie Cretaceows Group of the United States, 1834. @VOrbizny, A. : Paléontologie francaise, Description de Animaux invertébrés. Ter- rains Cretaces (&chinides), vol. 6, 1853-1860. Reeside, J, B., Jr. A kare Cretaceous Sea Urchin, Scuteilasier cretaceous Uragin, U. 8. Nat. Mus., Proc. vol. 66, Art. 20, 1924. Roemer, i, Die Kreidebildungen von Texas wad ire crganiscren Hinschliisse, 1852. Roig, M. S. Los equinodermos fosiles de Cuba, Cuca Direecion de Montes y Minas, Bol. Minas, No. 10, 1926. Schititer, C. Die regularen Echiniden der noradeuiscnen Kreide, 1883. Shumard, 8. F. Paleontology of the exploration of ihe Red Kiver of Louisiana in the year 1852. Rept. of Capt. RK. B. Marcy, U. S. Army, 1853. 79 CRETACEOUS ECHINOIDS: IKINS 31 Smiser, J. S. A study of the Echinoid fragments in the Cretaceous rocks cf Texas. Jour. of Pal., vol. 7, No. 2, 1933. Stoliczka, F. Mem. Geol. Survey India, Cretaceous Hchinoidea, vol. iV, 1873. Ewenhofeil, W. H. Geology and invertebrate caleontology of the Comanciean and *‘ Da- kota’? Formations cf Kansas. State Geol. Survey of Kansas, Bull 9, 1924. Weisbord, N. H. Some Cretaceous and Tertiary Hckinoids from Cuba. Bull. Amer. Pal., vol. 20, No. 70e, 1934, Whitney, F. L. The Echinoidea of the Buda Limestone. Bulli. Amer. Pal., voi. 5, No. 26, 1916. ; Whitney, F. iL. Bibliography and index of North Amerwan Blesozoie Invertebrata. Bull. Amer. Pal., vol. 12, No. 48, 1922. Whitney, M. 1. Fauna of the Gien Rose Formation. Thesis M.A., Univ. of Tex. Li- brary, 1931. Whitney, M. I. Fauna of the Glen Rose #ormation. Thesis Ph.D., Univ. of Tex. Li- brary, 1937. Wright, T. Mon. British Fos. Hchinodermata of Cretaceous Horimetions. Paleon- tolographical Society, 1864-1882. Bev ARN 4 ae 4, PLATES PLATE 1 (4) 34. RuLLEaTIN 90 82 EXPLANATION OF PLATE 1 (4) Figure Page 1) (Codiopsissellardsi, n= Sp... Eee 12 a. Abactinal surface; b. lateral surface; c. adactinal surface; x 1 2. (Pedinepsis. engerrandi, n. Sp... 5... ee eee 14 a. Abactinal surface; b., lateral surface; c. adactinal surface; xX 1 3. Pedinopsis yarberoughi.n: sp... 2 2 eee 2. Abactina! surfsee; b. lateral surface; ec. adactinal surface; xX 1 4, Salenia leanderensis, n. sp. — —— {2 ee 16 a. Abectinal surface; b, lateral surface; c. adactinal surface; X 4 5. Salenia pseucowhitneyi, n. sp. —— Valo! i Went At 7 a. Abactinal surface; b. lateral surface; ¢. adactinal surface; x 1.5 Pu. 4, Vou. 25 Buu. AMER. PALEONT. No. 90, Pu. 1 3€ BULLETIN 90 EXPLANATION OF Figure il, Salenia scotti, n. sp. b. a. Abactinal surface; < 1.6 Salenia stenzeli, n. sp..__-__ a. Abactinal surface; x 1.5 b. Salenia whitneyi Cannon a. Abactinal surface; x1 b. Goniophorus whitneyi, n. a. Abactinal surface; «4 b. Phymosoma bybeei, n. sp. a. Abactinal surface; x1 b. ‘lateral lagenall . Ts S195 lateral Spy == latera 5 lateral PLATE 2 surface; surface; surface; surface; 84 (5) Page ce. adactinal surface; ec. adactinal surface; c. adactinal surface; Laon 21 ec. adactinal surface; eee eee 23 ec. adactinal surface; >a Pu. 5, VOL. 25 Buu. AMER. PALEONT. 38 BULLETIN 90 86 EXPLANATION OF PLATE 3 (6) Figure Page 1. Pseudodiadema whitneyi, n. sp. 24 a. Abactinal surface; b. lateral surface; c. adactinal surface; x 5 : 2..- Holecty pus. bullardi,, 1... 'sp.222 = ee ee eee 25 a. Abactinal surface; b. lateral surface; ec. adactinal surface; x 4 3. Holectypus hondoénsis Cannon n. sp. 26 a. Abactinal surface; b. lateral surface; c. adactinal surface; < 2 4. ‘Pyrina. whitneya; on. spice ee eee 26 a. Abactinal surface; b. lateral surface; ec. adactinal surface; << al 5. . Nucleolites wilderz,n. sp).9. 22) 4.2 eee 26 g a. Abactinal surface; b. lateral surface; c. adactinal surface; x UU Pu. 6, VOL. 25 Buu. AMER. PALEONT. 4() BuLLETIN 90 88 EXPLANATION oF PLATE 4 (7) Figure Page 1. .<@Bmallaster texanus (Roemer)... ee eee 10 a. Section of unpaired ambulacrum; b. section of left anterior paired ambulacrum; highly magnified 2. Heteraster oblongus ‘Brongniart => Paneer te 10 a. Section of unpaired ambulacrum; b. section of left anterior paired ambulacrum; highly magnified Buuu. AMER. PALEONT. No. 90, Pu. 4 PL. 7, Vou. 25 BULLETINS AMERICA — PALEONTOLOGY _ VOL XKV * NUMBER 91 1940 = Paleontological Research Institution Ithaca, New York We Sey, Uae oy 4 ve soa BULLETINS OF AMERICAN PALEONTOLOGY Vol. 25 No. QI Some New Crinoid Species from the Morrow Subseries By Harrell W. Strimple January IT, 1940 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaca, New York Wo S Ao . » - i: oe 0 im ’ a ( : I * ” SOME NEW CRINOIDS FROM THE MORROW SUBSERIES By HarreELL L. STRIMPLE INTRODUCTION For additional knowledge of Morrow crinoids we are deeply obligated to Mr. Audd Dailey of Holdenville, Oklahoma. Mr. Dailey has with much patience, found a little known crinoid bed near Fittstown, Oklahoma, conducted the author and his wife, Mrs. Melba Strimple, to the locale for collecting, and placed his collection at the disposal of the author. It is most fortunate that Mr. Dailey has taken such a strong interest in Paleontology, and recognizes the advisability of presenting his important findings to science. Presented herein is a more or less preliminary report on the new forms observed to date. Of course it is understood that consistent collecting, over a long period of time, will bring to light many more forms than now known. It is hoped that event- ually we will have a more comprehensive selection of these rare Morrow crinoids. IDIRSCRIUPIION Ole SPaXCWas Family ICHTHYOCRINID Angelin (Emend. Wachsmuth and Springer) Genus AMPHICRINUS Springer Amphicrinus divergens, n. sp. Plate 1, figs. 11, 12 Calyx shallow, expanding rapidly; diameter, 10 mm.; height, 4 mm. Proximal columnal is in place so that pres- ence or absence of IBB not known; BB five, protrud- ine well out from under proximal columnal, that of the posterior no longer than others and truncated for the reception of anal X; RR low wide plates; seven-sided save those of the posterior which are six-sided; IBr' either five- or six-sided, low wide plates; IBr? are axillary and five-sided. That of the an- 4 BULLETIN 91 92 terior is strongly encroached upon to the left by a comparatively large is.terbrachial. The iBr', where preserved, are small hexa- gonal plates followed by two. In those rays preserved the arms appear to branch again with the II1Br*. Anal X is rather large, five-sided, followed by a single plate. The upper extremity has a diagonal slant so that the left side is considerably higher than the right. This plate readily distinguishes the species from other known forms. Occurrence and horizon.—Morrow subseries (limey blue shale just above the Caney shale formation), Pennsylvanian period; 6 miles SE of Fittstown, Oklahoma. Type.—Springer Collection of the U. S. National Museum. Collected by Mrs. Melba Strimple. Family CATILLOCRINID4 Wachsmuth and Springer Genus CATILLOCRINUS (Troost) Shumard Catillocrinus morrowensis, n. sp. Plate 1, figs. 7-10 Cup high, bowl-shaped; largest observed measures 6 mm., high; to mm., diameter. Basal disk low, occupied in the main by large columnar scar. Sutures not discernable in large figured specimen, but in the smaller, three unequal elements are observed, the smaller being posterior in position. The majority of the cup is composed of very large, unequal radials. R. post. R and 1. ant. R are small; each faceted for the reception of a single, com- paratively large arm; that of the r. post. having a small raised process for the reception of anal X; and the upper extremities of both are strongly encroached upon by adjoining RR, particularly the right shoulder of r. post. R which supports a long, narrow extension of the r. ant. R. The other three RR are large, ex- panding strongly, and sharply flared laterally at the upper ex- tremities. In the largest observed specimen the r. ant. R is faceted for the reception of 12 arms, |. post. R, 9 arms, and the largest, ant. R, 15 arms. The articular facets are identical with other known Catillocrinus. The median portion of RR are decidedly tumid, giving the specimens a pentalobate appearance when viewed from below. The calyx pattern is similar to C. carpentert, and C. 93 Morrow CrINOIDS: STRIMPLE 5 scoticus, which is to be expected since these species are closest stratigraphically. It is to be noted, however, that these species do not follow the calyx pattern that is typical of Catillocrinus. Surface of cup is sprinkled with minute granulations. Occurrence and horizon.—Morrow subseries, Pennsylvanian period; 6 miles SE of Fittstown, Oklahoma. Types.—Springer Collection of the U. S. National Museum. Collected by H. L. Strimple. Family POTERIOCRINTID2® Bassler Genus HYDREIONOCRINUS de Koninck Hydreionocrinus daileyi, n. sp. Plate 1, figs. 4-6 Calyx very shallow, saucer-shaped; height, 6 mm.; maximum diameter, 16.5 mm. Basal depression small, not very deep; IBB 5, small, equal elements comprising the floor of basal depression ; BB 5, large, hexagonal elements, lower extremities curved under to form walls of basal depression, main portion of plates resting horizontally; post. B truncated for reception of anal X, and r. post. B for reception of radianal; RR 5, pentagonal, wider than high, median portions protruded outward and slightly downward as large spatulate-shaped protuberances. Articular facets devel- oped slightly upward as wide shelves. To the fore is a sharp ligamental furrow, backed by a narrow cross ridge which is broken in mid-section by a v-shaped notch. Ambulacral notch only slight; muscle scars shallow, developed laterally. Anal X is rather small, pentagonal, resting solidly on post. B well within the cup. Radianal rather large, elongate, pentagonal. Right tube plate very long, six-sided, curving strongly inward so that the upper facet forms a horizontal plane with the quadrangular azygous plate resting on the anal X. Columnar scar is small, round, heavily crenulated, and pierced by a minute round axial canal. Surface of calyx plates are smooth. The spectacular spatulate protuberance of the RR and distinct anal pyramid distinguishes this species from other known forms. If the factor of shallow and deep cups were established as suf- 6 BULLETIN 91 94 ficient for generic separation, this species could be assigned to Plaxocrvinus Moore and Plummer, but unfortunately the author has at hand growth stages, from a higher horizon, that show some species of these forms have a deep calyx when young and are yet very shallow in maturity. Pending a more comprehensive understanding of these forms there seems to be no alternative but to assign them to Hydreionocrinus. Occurrence and horizon.—_Morrow subseries, Pennsylvanian period; 6 miles SE of Fittstown, Oklahoma. Type.—sSpringer Collection of the U. S. National Museum. Collected by Mr. Audd Dailey of Holdenville, Oklahoma. Genus ETHELOCRINUS Kirk fithelecrinus oklahomensis Moore and Plummer . Plate 1, figs. 1-3 Ethelociimus oklahomensis Moore and Plummer, 1938, Denison Univ. Bull., Journ. Sei. Lab., vol. 32, p. 256. There is at hand a complete set of magnificent arms of E. okla- homensis. The calyx was hopelessly smashed in preservation and all plates net saved, but there is fortunately enough remain- ing to definitely establish the species. The post. B shows the presence of the large radianal in addition to the anal X. Two IBB plates, devoid of ornamentation, show the flattened basal disk. Normal, well preserved, heavily ornamented RR and BB conclude the identification. The arms are massive, numbering ten, branching once on the primibrachs, and are thought to be approximating their maximum length, measuring 62 mm. long., with a mean width of around 8 mm.; strongly rounded backs and very thick. Pinnules not so large as would be expected. Primibrachs are large, wide, and heavily ornamented, knoblike protuberance just below the apex, and followed by two stout, low brachials. Those brachials fol- lowing are ornamented, low, interlocking plates up to about mid- length of the arms where, for some unknown reason, the arms start to swell and protrude, climaxing with sometimes a right, sometimes a left brachial becoming even larger and developing into a massive spine. Some of the plates adjoining develop ~ 95 Morrow CriINOIDS: STRIMPLE smaller spines. After climaxing the arms rapidly return to nor- mal appearance, although the width is more slowly lost. Upper brachials are not pronouncedly ornamented. Occurrence and horizon.— Morrow subseries_ (limey blue shale just above the Caney shale formation), Pennsylvanian period; 6 miles SE of Fittstown, Oklahoma. Figured specimen.—Springer Collection of the U. S. National Museum. Collected by Mr. Audd Dailey of Hoidenville, Okla- homa. Genus DELOCRINUS Miller and Gurley Delocrinus convexus, n. sp. Plate 1, figs. 13, 14 Cup low, bowl-shaped; height, 5.5 mm.; diameter, 12 mm.; base is gently convex or flattened; IBB five, small, equal elements ; BB five, large, hexagonal plates, well rounded to participate in the basal convexity ; post. B truncated for the reception of anal X; RR five, large, regular elements, slightly wider than high. Arm articu- lar facets developed inward as horizontal shelves, notched to the fore by sharp ligamental furrow, backed by low cross ridge. Anal X rather elongate, resting solidly on post. B, half in half out of cup, hexagonal-shaped, followed apparently by a single anal plate. Of the arms there are only a few brachials preserved, the r. ant. IB‘ is in place and proves to be low, wide, and nonawnillary. Columnar scar is small, round, heavily crenulated, and pierced by a minute, round, axial canal. This species is obviously not a true Delocrinus, but neither does it follow the characteristics of other known forms. Pending a more comprehensive knowledge of the arms it seems best to place it under Delocrinus. Occurrence and horizon.—Morrow subseries (limey blue shale just above the Caney shale formation), Pennsylvanian period; 6 miles SE of Fittstown, Oklahoma. Type.—Springer Collection of the U. S. National Museum. Collected by Mr. Audd Dailey of Holdenville, Oklahoma. 8 BULLENN 91 96 REFERENCES Moore, R. C. and Plummer, F. B. 1938. Upper Carboniferous crinoids from the Morrow subseries of Arkansas, Oklahoma, and Texas: Denison Univ. Bull. Journ. Sei. Lab., vol. 32, pp. 209-313, 5 pls. Springer, F. 1920. Crinoidea Flexibilia: Smithsonian Inst., Publ. 2501. 1923. On the fossil crinoid family Catillocrinidae: Smithsonian Mise. Coll., vol. 76, No. 3, 41 pp., 5 pls. Wright, James. 1939. The Scottish Carboniferous Crinoidea: Trans. Royal Soe. of Edinburgh, vol. LX, Part 1, (No. 1). PLATE 1 (8) 10 BULLETIN 91 EXPLANATION OF PLATE 1* (8) Figure Page 1-3. Ethelocrinus oklahomensis Moore and Plummer... ss Fig. 1, view of arms ;fig. 2, radial plate found associated with arms; fig. 3, posterior basal plate found associated with arms. 4-6. Hydreionocrinus daileyi, n. sp... posterior view. 7-10. Catillocrinus morrowensis, n. sp, Figs. 7-9, largest observed specimen, posterior view, view from above, view from below; fig. 10, smaller specimen, view from below showing protrusion of radials, and three basals. 11, 12. Amphicrinus divergens, on. spi. eee Fig. 11, anterior view; fig. 12, posterior view. 13, 14. Delocrinus: ‘convexus; n: sp. eee eee Fig. 18, view from below; fig. 14, anal x to the left. * Figure 1 natural size, all others X2. Pu. 8, VOL. 25 Buty. AMER. PALEONT. No. 91, Pu. 1 AMERICAN PALEONTOLOGY * VOL. XXV * NUMBER 92 1940 Paleontological Research Institution Ithaca, New Vork Ue Sue: Sibi iens Sauk an BULLETINS OF AMERICAN PALEONTOLOGY Vol. 25 Four New Crinoid Species from the Wewoka Formation And Two from the Ochelata Group : By Harrell L. Strimple January 15, 1940 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaca, New York Ws Sb Ac MOWR, INEM (CIRIUNOMUD SIPIACHWES JUXOME Iis8 WEWOKA FORMATION AND TWO INROIM Wels, OCEIMLATA GINOUIT By HARRELL L. STRIMPLE INTRODUCTION For our knowledge of crinoids from the Wewoka formation, we are deeply indebted to Mr. Audd Dailey, of Holdenville, Okla- homa, who has been kind enough to place his collection at the disposal of the author. These forms will form a valuable link between the lower and upper Pennsylvanian, which has hitherto been practically unknown. Mrs. R. I. Pound, of Bartlesville, Oklahoma, contributed the excellent specimen of Amphicrinus. The form herein described as Euonychocrinus dubius, n. g., n. sp., has been known to us for some time, but not until recently was the excellent specimen, figured subsequently, found by my wife, Mrs. Melba Strimple. DE SCRI-MONSOReS Pa Cuns Order FLEXIBILIA Zittel Family ICHTHYOCRINIDZ Angelin (Emend, Wachsmuth and Springer) Genus EUONYCHOCRINUS, n. g. A cursory examination of the form at hand discloses that it 1s quite different from other known Pennsylvanian Flexibilia. The horizontal development of the arms certainly reminds one of the Mississippian Onychocrinus, but since it is hardly possible that the genus would survive such a long lapse of time without any intermediate forms, and in fact since the form at hand is distinct within itself, it is deemed advisable to propose a genus for its re- ception, Euonychocrinus, n. g., seeming appropriate. 7 } 45 4 BULLETIN 92 102 Generic description Cup low, expanding rather rapidly; IBB (if present), and most of five BB covered by wide proximal columnals ; post. B larger than other BB, and truncated for recep- tion of anal X; RR five, low, wide elements, articular facets for reception of arms developed almost horizontally; anal X quad- rangular, developed inward; interbrachials four, small, elongated elements. Of the arms our knowledge is limited to the first few brachials, which are developed strongly outward, taper consider- ably, and have strongly rounded backs. Genotype—Euonychocrinus dubius, n. g., n. sp. Occurrence and horigon.—Pennsylvanian ; North America. Euonychocrinus dubius, n. sp. Plate 1, figs. 11-13 Cup low, expanding rapidly; diameter, 9.3 mm.; height, 2.5 mm.; large, columnar scar covering IBB (if present) and most of the BB; post. B considerably longer and wider than other BB, and is truncated for the reception of anal X ; RR five, rather large, wide, pentagonal elements ; that of the I. post. is developed strong- ly inward to form a support for the anal X and in fact participates in forming a portion of the wall for the ambulacral groove of the l. post. arm; articular facets developed outward; anal X large quadrangular element, broadly truncated for the reception of a single azygous piece, developed inward at right angles with the horizontal arms, and outward facing articular facet of post. B; first interbrachials four, there being no r. post. in position, elon- gated, slightly above mid-height suddenly sharply notched, ap- parently for the reception of very narrow secondary pieces, upper extremity truncated for reception of a single plate, these plates are developed slightly outward at an angle between the almost hori- zontal arms, and the almost vertical anal X. Of the arms our knowledge is limited to the first few brachials, which are rather stout, considerably narrower than the RR, rounded backs yet with wide shallow ambulacral grooves. Tegmen unknown. Proximal columnals are very thin, wide, round, lightly crenu- lated about the perimeter, and pierced by a minute axial canal. 103 PENNSYLVANIAN CRINOIDS: STRIMPLE 5 Holotype.—Springer Collection, U. S. National Museum. Col- lected by Mrs. Melba Strimple. Occurrence and horizon.—Stanton limestone member, Miss- ouri series, (Ochelata group), Pennsylvanian; near Wayside, Kansas. Comparatively common. Amphicrinus simplex, n. sp. Plate 1, fig. 1 Cup low, expanding rapidly ; diameter, 16 mm.; height, 5 mm. ; IBB (if present) and much of BB covered by large proximal columnal; BB five, extending well out from under proximal columnal, particularly that of the post. which is broadly truncated for the reception of anal X; RR five, low, wide plates, those of the posterior being six-sided, others seven-sided; anal X large, six-sided, followed by a small, narrow, elongated secondary piece to the left, faceted for the reception of a large azygous plate above, the right shoulder is slightly dropped, but not so pronounced as in A. divergens Strimple; the small secondary azygous piece is followed by a small, four-sided piece, which is overhung by IBr?. Of the arms our knowledge is limited to those of the 1. post. and ]. ant.; IBr* are low, wide, nonaxillary plates; IBr? are not quite so low, wide, axillary pieces, branching once, and no further evi- dence of branching through the I]Br* observed. Primary iBr observed are comparatively large, hexagonal plates, followed by two rather elongated, six-sided plates, third series composed of three, very narrow, elongated plates, the outer ones being five- sided, the middle hexagonal, fourth series composed of two elon- gated plates. Observed primary ill Br elongated, hexagonal plate. This form is quite distinct from other known species of Amphi- crinus in the arrangement of azygous pieces together with the ar- rangement and number of primary iBr, and since it is from a horizon from which few crinoids have keen known, it seems ad- visable to erect a new species for its reception. Holotype.—Springer Collection, U. S. National Museum. Col- lected by Mrs. R. I. Pound, of Bartlesville, Oklahoma. Occurrence and horizon.—Wewoka formation, Pennsylvanian ; near Holdenyille, Oklahoma. 6 BULLETIN 92 104 Order INADUNATA Wachsmuth and Springer Suborder FISTULATA Wachsmuth and Springer Family POTERIOCRINITID Bassler Genus SCYTALOCRINUS Wachsmuth and Springer Scytalocrinus pentacolumnus, n. sp. Plate 1, figs. 14, 15 Cup high, turbinate-shaped; IBB visible from side view; dia- meter, approximately 7.8 mm.; height, 6 mm.; IBB five, small regular elements; BB five, large six-sided elements, save that of the posterior which is truncated for the reception of anal X; RR five, large, pentagonal plates, slightly wider than high; anal X hexagonal, radianal pentagonal, right tube plate apparently six- sided, all three being approximately equal in size. All plates of the cup have scalloped appearing edges, so that a raised portion meets like occurrence on the adjoining plate. Arms unobserved save for r. post. [Br’, same being elongated, constricted in mid-section, and axillary. Tegmen unknown. Proximal columnal 1s pentagonal, crenulated about the perim- eter, and pierced by minute round axial canal. Relationship.—The peculiar scalloped appearing edges of the plates, and the pentagonal stem, serve to distinguish this form from other known species. Holotype.—Springer Collection, U. S. National Museum. Col- lected by Mr. Audd Dailey of Holdenville, Oklahoma. Occurrence and horizon.—Wewoka formation, Pennsylvanian ; near Holdenville, Oklahoma. Rare. Genus DELOCRINUS Miller and Gurley Delocrinus parinodosarius, n. sp. Plate 1, figs. 3, 5, 8 Cup low, bowl-shaped; diameter, 13 mm.; height, 4 mm.; fun- nel-shaped basal cavity; IBB five, small, confined to the basal cavity; BB five, large, six-sided save for that of the posterior which is truncated for the reception of the small anal X, lower extremity curved under to participate in basal concavity, elon- gated, shallow depression occupies median portion of plates; RR five, normal, wider than high, pentagonal elements, upper por- 105 PENNSYLVANIAN CrINOIDS: STRIMPLE 7 tion slightly protruded and occupied by a crescent-shaped row of nodes, above which the cup is constricted; anal X small, elongo- hexagonal, resting well within the cup, articular facet is shallow, rounded depression as is characteristic of Delocrinus, faceted for the reception of a single azygous plate. The columnar scar is small, round, crenulated, and pierced by a minute star-shaped, axial canal. The surface of the calyx is rough, but only those nodes on the RR are prominent. This feature, together with the shallow de- pressions of the BB constitute the main characteristics differenti- ating the species from other known forms. Holotype.—Springer Collection, U. S. National Museum. Col- lected by Mr. Audd Dailey of Holdenville, Oklahoma. ~ Occurrence and horizon ——Wewoka formation, Pennsylvanian ; near Holdenville, Oklahoma. Delocrinus wewokaeénsis, n. sp. Plate 1, figs. 2, 4, 6 Cup very low, saucer-shaped; diameter, 21 mm.; height, 7.5 mm.; funnel-shaped basal cavity, very wide; IBB five, small, equal elements confined to the bottom of the basal cavity; BB five, large, pentagonal elements, that of the posterior being six- sided by virtue of supporting anal X, lower portion curved under to form walls of basal concavity; RR five, large pentagonal, reg- ular elements, articular facets developed inward as wide horizon- tal shelves; anal X rather large, elongo-hexagonal, resting well within cup; articular facet split for two secondary pieces, that facet to the left being larger and almost covering the entire surface to the fore, both of the facets being rather shallow, with the rim mildly crenulated. The cup is smooth. Columnar scar is small, round, heavily crenulated and pierced by minute, star-shaped, axial canal. Arms and tegman unknown. Relationship.—This form is not a true Delocrinus, even though possessing most of the characteristics of one, due to the upper articular facet of the anal X. The form is not considered distinct enough to segregate generically, and is probably the immediate 8 BULLETIN 92 106 predecessor to that form known as D. hemisphericus (Shumard). Holotype.—Springer Collection, U. S. National Museum. Col- lected by Mr. Audd Dailey of Holdenville, Oklahoma. Occurrence and horizon.—Wewoka formation, Pennsylvanian ; near Holdenville, Oklahoma. Comparatively common. . Genus PENTADELOCRINUS Strimple Pentadelocrinus twinensis, n. sp. Plate 1, figs. 7, 9, 10 Cup rather low, bowl-shaped ; diameter, 16 mm.; height, 6 mm. ; base shallowly concave; IBB five, small, regular elements, extend- ing well beyond the proximal columnal, and confined to the basal cavity; BB five, rather large, six-sided elements save that of the posterior which is seven-sided, being truncated for the reception of anal X, lower extremities curved under to participate in basal concavity, decidedly tumid and recurving at outer margins to form confluent ridges with adjoining pieces; BB five, large pen- tagonal elements, slightly wider than high, tumid, and recurving at the sutures, strong articular facets developed inward as wide, sloping shelves, strong ligamental furrow to the fore climaxed by a sharp deep notch in midsection, all well shown in the illustra- tions ; anal X rather large, elongated, six-sided, resting well with- in the cup, and faceted for the reception of two azygous plates. Of the arms our knowledge is limited to the r. post. IBr', which is very low, and nonaxillary. All plates are very delicately granular. Tegmen unknown. Proximal columnal is pentagonal, crenulated, and pierced by a minute axial canal. Relationship.—This form is quite similar in general appearance to Cibolocrinus regularis Moore and Plummer, however, the presence of five IBB and a pentagonal stem eliminates even gen- eric relationships. The species is quite distinct from P. typus Strimple in the tumidity of the plates, fuller calyx, granular sur- face, and in the recurving of the outer extremities of the calyx plates. P. typus is saucer-shaped, sutures regularly depressed and is smooth. Holotype.—Springer Collection, U. S. National Museum. Col- lected by H. L. Strimple. Occurrence and horigon.—‘Gastropod” shale zone, Ochelata group, Pennsylvanian; “Twin Mounds” 5 miles SE of Ochelata, Oklahoma. Rare, — 107 PENNSYLVANIAN CRINOIDS: STRIMPLE an) REFERENCES Bassler, R, S. 1939. Paleozoic Pelmatozoa. Moore, R. C. and Plummer, F. B. 1938. Dennison Univ. Bull., Journ. Sci. Lab., vol. 32, p. 235, pl. 16, figs, 2a-d. Shumard, B. F. 1858. Trans. St. Louis Agad. Sei., vol. 1, p. 221. Strimple, H. L. 1939. Bull. Amer. Paleo., vol. 24, No. 87, p. 11, pl. 1, figs. 7-9. 1940. Bull. Amer. Paleo., vol. 25, No. 91, p. 3, pl. 1, figs. 11, 12. 10 BULLETIN 92 108 EXPLANATION OF PLATE 1 (9)* 1: vAmphicrinus: ‘simplex, nj sp. ee Oblique side view of holotype. Wewoka formation, near Holdenville, Okla. . 2, 4, 6. Delocrinus wewokaénsis, n. sp. — vee eee View from above, side view of posterion siadl 5 view 7 Beara be- low; holotype. Wewoka formation, near Holdenville, Okla. 3, 5, 8. Delocrinus parincdosarius, n. sp. —.—— oe pete te = View from below, view from above, and siidle « view 7 or poste- rior; holotype. Wewoka formation, near Holdenville, Okla. 7,9,10. Pentadelocrinus twinensis, n. sp. = Side view of posterior, slightly alice view Soma bellow, and view from above; holotype. Ochelata group, “Twin Mounds” near Ochelata, Okla. 11-13, Euonychocrinus dubius, n. g., n. sp. View from below, side view of posterior, and view from above; holotype. Stanton ls. member, Missouri series (Ochelata group), near Wayside, Kansas. 14, 15, Seytalocrinus pentacolumnus, n. sp. ee ee 2s: 2 eens Oblique anterior view, and view 68 Mposterion. jholleiyoe. Wewoka formation, near Holdenville, Okla. * All figures enlarged X2. 4 Pu. 9, Vou. 25 Buu. AMER. PALEONT. No. 92, Pu. 1 if ye bay hay ane ADDENDA March 7, 1940 BULLETIN 92A SHEPELEAKOCRINGS, NEW NAME FOR WAHITEOCRINUS STRIMPLE By HARRELL L. STRIMPLE Lf¥ 0 so ADDENDA SIMEILILAUIROCIRUN US, INDE! INDAGMNE, TROUR TVIGHOIPEOCIRUN US, SWI UMUPILe By FARRELL L. STRIMPLE I described in these Bulletins’, as a new genus, IVhiteocrinus, to receive those Pennsylvanian crinoid forms typified by Cyatho- crinus stillativus White, which species was taken as the genotype. It has been called to my attention that |] hiteocrinus 1s a preoc- cupied name, having been used by Jaekel’. Therefore, I propose a new generic name, Stellarocrinus, with Cyathocrinus stillativws White as the genotype. So far as known to the author, the only reference which has heen made to IIlhiteocrinus Strimple (not Jaekel), subsequent to its inception has been by Moore’. This opportunity is taken to extend our knowledge of Stellaro- crinus stillativus (White), and present a new species as Stellaro- crimus Cistinctus, n. sp. IDIZ SCRIPTION Ole Slee) Order INADUNATA Wachsmuth and Springer Suborder FISTULATA Wachsmuth and Springer Family CYATHOCRINID2 Roemer (Emend, Wachsmuth and Springer) Genus STELLAROCRINUS, n. n. Genotype.—Cyathocrinus stillativus White. Stellarocrinus stillativus (White) Plate 1, figs. 1-4 Cyathocrinus stillativus White, 1880, Proc. Nat. Mus., vol. 2, p. 258; 1880, Geol. Surv. of the Territories, p. 125, pl. 35, figs. 3a, b. 1 Strimple, Harrell L.: Bull. Amer. Paleont., vol. 25, No. 89, August, 1939) p. 4. 2 Jackel, O.: Pal. Zeits., Bd., 3, 1918, p. 58. 3 Moore, R. C.: Denison Uniy. Bull., Journ. Sei. Lab., vol. 34, Art. 6, December, 1939, p. 180 (as a footnote). 2 BULLETIN 92A 110 Cyathocrinus (?) stillativus Wachsmuth and Springer, 1886, Revision of the Paleocrinoidea, Part 3, Proc. Acad. Nat. Sci., Puila., p. 226. Phialocrinus stillativws Keyes, 1894, Geol. Survey Missouii, vol. 4, p. 219, pl. 28, figs. 6a, b. Whiteocrinus siillativus Strimple, 1939, Bull. Amer. Paleont., vol. 25, INjot 895 p= 05) ple dee tiest ly oe Oo) The two specimens at hand warrant figuring in that one is very young, and unusually well preserved, the other being mature, with most of the anal sac well shown. Immature specimen.—Cup low, with diameter of 6.4 mm.; height of 1.5 mm. (excluding articular facets). Arms are strap- like, extending outward for a short distance, then abruptly coiling inward. Only ten arms noticed, and the extremities are thought to have been observed, approximate length, 15 mm., mean width, 3 mm.; IBr’ elongated, median portion constricted, length, 3.1 mm.; subsequent Br low wide elements, incipiently interlocking. The tegmen is somewhat compressed, but is seen to be composed of stout, spiney plates, that which occupies the upper extremity pointing upward. The cup is not so strongly ornamented as in more mature forms. Mature specimen.—Diameter of calyx, 18.4 mm.; height to lower extremity of arm articular facet, 7.4 mm.; arms very fragmentary, measuring some 7 mm., wide, decidedly biserial, flat, straplike, branching once on [Br’, said plates being 4.2 mm., long, by 7 mm., wide ; tegmen not preserved in its entirety, but shown to be composed of circlets of stout, spinelike azygous plates. These plates are quite common in many of the middle Pennsylvanian formations. _ Cup strongly ornamented as is characteristic of the species. Comparison.—There is considerable change in ratio between height and width of calices, which is partially due to the strong protrusion of the RR in mature forms, and is not thought to be. necessarily representative of the species. Normally the calyx loses height with maturity, in many other observed genera of this period. The [Br* are reduced from 3:3 (length:width) to 4:7. The ornamentation is stronger in maturity, which seems character- istic of these forms. There is no appreciable difference in the arms, save the transition from incipiently biserial arms to decided- 111 PENNSYLVANIAN OCRINOIDS: STRIMPLE 3 ly biserial arms, and possibly proportionately greater width in maturity. _ Occwrence and horizon.—Immature specimen, Stanton lime- stone member, Missouri series, Pennsylvanian, near Wayside, Kansas. Mature specimen, Stanton limestone member, Ochelata group, Pennsylvanian, the mound just west of Bartlesville, Okla- homa., Iigured specimens.—Springer Collection, U. S. National Mu- seum. Collected by Mr. and Mrs. H. L., Strimple. Stellarocrinus distinctus, n. sp. Plate 1, fig, 5. Cup is high, bowl-shaped, measuring 4.1 mm., high (excluding articular facet), with maximum diameter of 89g mm. The arrang- ment 1s identical with that characteristic of the Cenuss ee eitenannms are known to branch once with the IBr! and again with about the I1Br‘, being at least 20 cuneiform arms; IBr! are elongated, measuring 5 mm., long, by 4 mm., wide (maximum) ; subsequent Br have rather rounded backs, save for those sides being larger, which are protruded as spines.- It is possible that the arms might become more or less biserial with maturity, and it is certain that the IBr* will lose some of its length to width. The arms appear to be tapering considerably at their most extreme point, indicative of approximating their maximum length, where they measure some 17 mm. in length. ., The column is composed of alternating expanded, round columnals. The tegmen is unknown. Relationship—The cup of this species is similar to S. exsculptus (Strimple)*, differing mainly in that the two ridges of each R in S. exsculptus do not pass the sutures. Considering that the specimen at hand is young, we have observed that with this unusual genus the calyx ornamentation apparently becomes more spectacular with maturity, and in any eventuality the form is de- cidedly more sharply angular than the gently ornamented S. ex- sculptus. Of S. stillativus there is figured herein a specimen con- siderably younger than the form at hand, wherein we have flat, incipiently biserial arms, as against the well rounded, cuneiform 2 MGeme os Dy Folly Aly ites 7S, 4 BULLETIN 92A WI) 20 arms of S. distinctus. Inthe fully mature form of S. distinctus we are certain to find some strong evidence of the spiney Br, as well as the early branching of the arms for the second time. Occurrence and horizon.—Stanton limestone member, Ochelata group, Pennsylvanian, the mound just west of Bartlesville, Okla- homa. Holotype.—Springer Collection, U. S. National Museum. Col- lected by H. L. Strimple. EXPLANATION OF PLATE 1 (10)* Figure Page Is, SUGEEST UIE COMMS) 2 1 obliterated by matrix, and side view showing exposed tegmen. Stanton limestone member, Ochelata group, Pennsylvanian, just west of city limits of Bartlesville, Oklahoma. 3,4. Stellarocrinus stillativus (White) —.... 1 Immature specimen. View from below (anterior), and view from above. Stanton limestone member, Missouri series, Pennsylvanian, near Wayside, Kansas. by) Stellarocrinus) distinct us. my Spe 3 Oblique anterior view. Stanton limestone member, Ochelata group, Pennsylvanian, just west of city limits of Bartlesville, Oklahoma. * All figures approx. X2. Pu. 10, Vou. 25 Buu. AMER. PALEONT. No. 92 App., Pu. 1 (Coe ps Research In BULLETINS OF AMERICAN PALEONTOLOGY Vol.. 25 Devonian Bryozoa from Colombia By Andrew H. McNair June 8, 1940 PALEONTOLOGICAL RESEARCH INSTITUTION Ithaca, New York U. S. A. i. CONTENTS Page UBS TRIAC Wier ate tees 4 Ae AN a ape Car Te a Eiticaene s R See No 5) LEN DR ODIU CERIO Nes renee, Seon teal! ree Ce he OEM Tea oa te 5 CATON SENS LIND NGI: Ole IVAWIN 6 METHOD OF STUDY AND REPRODUCTION OF SPECIMENS _....... 7 IDES CRIE-TION TONS VOZOAU «russ oe mime wee eile MUR ayy Mena to On : 8 STB ELOG RATS ivi Skee Niet UIs Veh eee aR Ove ns Pile LIS Oe PEED Milne (cs Me 21 DEVONIAN BRYOZOA FROM COLOMBIA By ANDREW H. McNair Dartmouth College eNJByS) REC IL A deseription of the Bryozoa from the Middle Devonian Floresta series of the State of Colombia, South America, is the purpose of this paper. Twenty-four new species are described. Although all of the species found in the fauna are new, they indicate strong relationship to the Middle Devon- ian bryozoans of eastern Nortn America and therefore show that the Flor- esta fauna is probably ‘‘boreal’’ rather than ‘‘austral’’ in origin and relationship. A description is given of the method used in photographing the specimens, all of which were preserved as impressions in soft shales. INTRODUCTION The specimens described in this paper were made available for study through the kindness of Dr. Kenneth E. Caster. They are a part of a fauna discovered by Mr. Axel Olsson and Dr. Parke A. Dickey in 1935, from the Floresta series of the State of Colombia. The cooperation of these men and the International Petroleum Company by whom they were employed has made this study possible. The fossils of the collection, other than bryozoans, have been described by Caster (1939). The present paper com- pletes the description of the large and varied collection of Olsson and Dickey. The author wishes to express his appreciation to the men who have aided him, either directly or indirectly, during the course of this study. He is especially indebted to Professor G. D. Harris and the Paleontological Research Institution for facil- ities of publication. 6 BULLETIN 93 118 The fauna described here was collected from the Floresta series of Colombia, at exposures on the automobile road between Santa Rosa and Corales in the western part of the Departmento de Boyaca. =, & = ay aS oa ¢ ae Area, SANS 8... Ss a Y See Wipes: Dire pore’ Be ee Ses eee = as NY Be Aree ORO Ces ie On ities ve, PS {) é pe C) selec PN a a ‘De ee 24 ey A So s30, JILIN, IOOl O00) 28 BULLETIN 93 140 EXPLANATION OF PLATE 3 (13) Figure Page 1. -Fenestrellina colombiana, n.. sp. ee 12 Obverse face of holotype showing form of branches and fene- strules. Carine not well shown on figure. Pal. Res. Inst. No. 5892. 2. Fenestrellina colombiana, n. sp... 12 Obverse face showing diverging branches, from immature part of zoarium. Paratype. Pal. Res. Inst. No. 5893. 3. Fenestrellina acuta; n: (Spree: =.= 2 ee eee 14 Obverse face showing oblique dissepiments and apertures with- out peristomes. Holotype. Pal. Res. Inst. No. 5895. 4, Fenestrellina olssoni, n. sp. Sl 13 Obverse face showing wide branches, prominent carine and strong dissepiments. Left part of specimen eroded. Holotype. Pal. Res. Inst. No. 5896. 5.< Fenestrellina- olssoni,, n.. spi EE EE 13 Reverse face showing strong branches and wide fenestrules. Spines on branches not well shown. Paratype. Pal. Res. Inst. No. 5897. 63"* Fenestrellina olssoni,, n, isp. #222. 2 22) ee eee = ils Interior of branches showing shape and arrangement of zoccia. Paratype. Pal. Res. Inst. No. Bel 7. Fenestrellina colombiana, n.. sp.._--_---7_----_----_-- 12 Reverse face showing shape and arrangement of branches and fenestrules. Paratype. Pal. Res. Inst. No. 5894. 8. ~FKenestrellina: quadrata, ny Sp).....22 ee eee eee 14 Obverse face showing fenestrules of two sizes and shape of branches and dissepiments. Branches have been squeezed during preservation so that only one range of apertures is visible on most branches. Holotype. Pal. Res. Inst. No. 5899. 9. Fenestrellina quadrata, n. sp). 2=. = eee 14 Reverse face showing fenestrules of two sizes. Branches thin- ner and fcnestrules smaller than holotype, indicating that speci- men came from immature part of zoarium. Paratype. Pal. Res. Inst. No. 5900. Figure BULLETIN 93 142 EXPLANATION OF PLATE 4 (14) Page Feneéstrellina hharrisi, “n.. Sp... 7-22 eee Obverse face of zoarium showing method of branching, prom- inent apertures and indented fenestrules. Holotype. Pal. Res. Inst. No. 5901. Fenestrellina. harrisi, 1. Sp,...--2-22222...2 2 a eee 15 Reverse face showing shape and arrangement of “pranches, dissepiments and indented fenestrules. Paratype. Pal. Res. Inst. No. 5902. Semicoscinium colombiensis, n. sp... 15 Obverse face showing flexuose branches and circular fenes- trules. Carina broken. Paratype. Pal. Res. Inst. No. 5903. Semicoscinium colombiensis, n. sp. -—-—--..--------- 15 Obverse face showing elliptical fenestrules. Right side of specimen eroded. Holotype. Pal. Res. Inst. No. 5904. Semicoscinium colombiensis, n. sp... 2 15 Reverse face showing angular branches and dissepiments. Pro- jections on branches not well shown. Paratype. Pal. Res. Inst. No. 5905. Semicoscinium (?) minutum, n. sp. 16 Obverse face showing size and distribution of branches and dissepiments, high carine and inflected fenestrules. Holotype. Pal. Res. Inst. No. 5906. Unitrypa casteri, mi Spl =. eee 17 Obverse face showing superstructure on the right and branches with apertures on the left. Superstructure slightly eroded and not as massive as typical specimens. Holotype. Pal. Res. Inst. No. 5907. Unitrypa’ casteri;-né sp... ee eee eee 17 Surface of superstructure showing delicate longitudinal ridges and connecting bars and the hexagonal openings between them. Paratype. Pal. Res. Inst. No. 5908. Unitrypa Caster, n. ‘Spc 22 17 Obverse face of a specimen believed to belong to this species, showing shape and distribution of fenestrules, branches and dissepiments. Paratype. Pal. Res. Inst. No. 5909. Pu. 14, Von. 25 Buu. AMER. PALEONT. No. 93, Pu. 4 Se . 4 wa Lee

s, es, ” % 28 : fe Galea Ce oe Po Deere BE FR ae 4 a rig Orly Oo oe 3 K Sd aes A » : 4 n eA” F Gee ee ASele ae ort sei os AS: 4 ob ‘ 7 : « 3 : : “< , * Fo a Pars %5 - SOO ME GS OP a see igpgeuds Soe Se Te ame gna) & 32 BULLETIN 93 EXPLANATION OF PLATE 5 (15) 144 Figure Page L... Polypora elegantula, n, sp. eee Obverse face of specimen from mature zoarium showing straight rounded branches and elliptical fenestrules. Holo- type. Pal. Res. Inst. No. 5910. 2. ‘Polypora ‘elegantulla, ‘n.. sp. 22. ee Obverse face of specimen from immature zoarium showing diverging branches. Paratype. Pal. Res. Inst. No. 5911. 3. Polyporagranulifera, ni ispwte 2) ee eee Reverse face of specimen from mature part of zoarium show- ing large fenestrules. Paratype. Pal. Res. Inst. No. 5913. 4. Polypora granulifera, n. sp. a Obverse face of a typical specimen showing size of breaelnas, longitudinal ranges of apertures and longitudinal strie. Para- type. Pal. Res. “Inst. No. 5914. 5.7 -Polypora: eranulifera, n.. sp... Reverse face showing angular branches. and _ dissepiments. Paratype. Pal. Res. Inst. No. 5915. 6... Polypora granuilifera, mn: spit eee Hroded specimen showing interior of branches. Paratype. Pal. Res. Inst. No. 5916. te Polypora’ granuliféra,: sn: spy 2.2 ee eee Reverse face showing very angular branches and dissepiments. Specimen from mature part of zoarium. Paratype. Pal. Res. Inst. No. 5917. 8. Polypora. granulifera, n, Sp... ee ee eee Obverse face from mature part of zoarium. showing size of - branches, longitudinal ranges of apertures and inconspicuous longitudinal ridges. Holotype. Pal. Res. Inst. No. 5912, Buu. AMER. PALEONT. No. 93, PL. 5 Pu. 15, VOL. 25 ro h ‘ -,. ; yo ANS Al ae, G PEATE Vil Cat) 34 BULLETIN 93 | 146 EXPLANATION OF PLATE 6 (16) Figure Page 1, PEO DD Sul SEMESE, TD aS TO chee oe eee a - 19 ridges. Secondary ianichies have ie poker from specimen, Holotype. Pal. Res. Inst. No. 5918. 2. Sulcoretepora olssoni, ni sp... eee 19 Branch showing arrangement of apertures and longitudinal ridges. Secondary branches have been broken from specimen. Holotype. Pal. Res. Inst. No. 5919. 38. Prismopora inornata, n. sp. eee | | Bl Surface of a triangular branch. Lower right shows bifurea- tion. Note irregular arrangement of apertures. Holotype. Pal. Res. Inst. No. 5920. 4... Deniopora florestze,. ni. ‘Spy occu eS 20 Surface of branch showing strong median keel and arrange- ment of apertures. Specimen eroded. Holotype. Pal. Res. Inst. No. 5921. Pu. 16, Vou. 25 BULL. AMER. PALEONT. No. 93, Pu. 6 me Te : Sree Fin 8 pany 4 Paleontological- Research Institution & Gar tee ete CONDENSED TABLE OF CONTENTS OF BULLETINS OF AMERICAN PALEONTOLOGY. AND PALAONTOGRAPHICA Ancpnrcana* BULLETINS OF AMERICAN PALEONTOLOGY Volume I. (Nos. 1-5), 354 pp., 32 aie: — 8.00 Mainly Tertiary Mollusea. : TE(NOs: (6410). 847-ppo Bapls ee Se 10,0 ~ Tertiary Mollusea and Foraminifera, Paleozoic faunas... ao HE. 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Vee 5 600 ey Mainly Paleozoic faunas-and Tertiary Sinthusca: XXV._-(Nos. 88-94) not-complete. 154 pp., 18 pls. 95 : Paleozoic fossils of Ontario, Oklahoma and Colombia, Mesozoic -echinoids and California Tertiary mollusks. _ XXVI- (Nos. 95= -) not complete._264 pp,, 39 pls. _- cloth bound 4.59 g eS Marine spel. be paper bound 3.59 PALEONTOGRAPHICA A AMERICANA Volume-1 (NUs. 1-535 519-0. Tepigns sera a ee ae — $12,00 + Monographs of arcas, Lutetia, rudistids aa venerids. Il. (Nos. 6-11) not complete.” 490 pp., 81 pls, 2-2. =10.20-+ Monographs of corals, turrids, spondyli, brevicones, ~ Pseudorthoceratide and Fasciolaria. | AMERICAN ~ PALEONTOLO oe ae | ee VOLUXXYV © NUMBER 94B oe OSI . : " | Paleontological Research Institution PoP Ti a . BY ee AT ae en Tae = es 3 " # “ ns ta aeeaieom rine ey CONDENSED TABLE OF CONTENTS OF BULLETINS OF AMERICAN PALEONTOLOGY AND PALAHONTOGRAPHICA AMERICANA* BULLETINS OF AMERICAN PALEONTOLOGY Volume: Ti Soeces 5g cee nln oi Ye) ATR Oe Sex eee ae 5 us eeesenenee eae B) LE TOCUCELONIN ee eke ee Peet ee Ae eM ies i ents Soar R A Nera aed n noes 6 SS tinea ba ovat Tica rr aos Rte is ee BRR ie ee ene A ce ae Panipat ek 11 Sy Shenlati Ce CESCELpELOIUS py esac Gets ek pk eee ee Se ae 15 Girly yer ce Mg petit Rese es Sees rae eae cle oles er NeaMe le desea ir Wn oh ener eet eee 15 JNSR OIG ee Re etal A We ae MER Sot UN een, at SSIES Se ene 5 kine er 18 Rec tind copper ee tec crr. aes, ll as Sete Wal uu ee elo nei en ea eal eur eA 23 DAS Gevrabs Gl Se ten sete) seers Pee oer ttt nee ee An see eaten a) Lees et peter eed a 37 (@rassatellidzer sia bl Se Ge ie Nene enn An iene eee 46 PIS; eT Ch eee ee te ere i a ee ee a le RRM a) Da Le ee EE 51 PUSS ONG ATs Chia Cl Cates eae te ee coerce es es I rt ot Sane ee 55 WGiNGIeT Ge: ete oe eee ee aS gegen ns Cee Rd Oa ol oe 61 PAC G OI amet eon oe Sei Ae nw ke es MER So Bont ee ee 61 CLD ee Re eae ren eres ee re AT oe te 62 GOs lice eee Stee RS Ned a ee Ne ae Se ee 65 Stratigraphic and areal distribution of species __.........2eeeeeeeeeeee 70 SSynevcrin cry cra LO 11 CLUS 1S gp eae me Sa UL eee 95 NBO ANY ULIS bin ees stent sited nek thet eo eA tee Os oF ace) Sen Nee eee 101 Surnmanyaofmlocalitiess 61 evesse sh. ee wen ARE fle eb ae ace 107 Biloog arp Uyny<-see etn eee Mien me RS IAL RET enki s 0 Bale Seen 107 Waa A RA Ge ae Spear a ER er ae TMF co Ge ee eR eM eet 111 A STRATIGRAPHIC STUDY OF THE MOLLUSKS OF THE CALVERT AND CHOPTANK FORMATIONS OF SOUTHERN MARYLAND by Lois MARGARET SCHOONOVER ACKNOWLEDGMENTS The writer wishes to express her appreciation for the unlim- ited assistance, suggestions, and criticisms which have been given by many kind friends during the course of this investigation. The Department of Geology of Bryn Mawr College has made this study possible through an appointment as part-time Demon- strator over a period of four years, as well as through additional financial assistance in field work and in laboratory materials. The writer is especially indebted to Dr. Lincoln Dryden, under whose direction this study has been pursued, for his unfailing interest, and for his assistance in field and laboratory work, and in the. final preparation of the manuscript. Dr. E. H. Watson of Bryn Mawr College has also been very helpful with his encouragement and many suggestions. Dr. R. E. L. Collins, of the University of Tennessee, assisted materially in both field and laboratory work. During the course of this study visits were made to several in- stitutions where extensive collections and type specimens are de- posited. Officials and staff members in these institutions have all been most gracious and helpful in granting permission to use their collections and library facilities. Particular thanks are due the United States National Museum, Academy of Natural Sciences of Philadelphia, Maryland Geological Survey, Paleon- tological Research Institution, and Cornell University. At the United States National Museum, Drs. Julia Gardner, R. B. Stewart, F. S. MacNeil, and the late W. C. Mansfield gave much helpful advice and criticism. The author is very grateful for) BULLETIN 94B 170 to Drs. E. W. Berry and C. T. Berry for their kindness in mak- ing available the collections of the Maryland Geological Survey, particularly the type and figured specimens of the Miocene re- port. Miss Anne Harbison was of especial assistance in making available type specimens and library facilities in the Academy of Natural Sciences of Philadelphia. Dr. C. W. Merriam kindly permitted the writer to study the Cornell University collections. The writer is particularly grateful to Prof. G. D. Harris and the Paleontological Research Institution for the opportunity to publish this study at the present time. Prof. Harris and Mrs. K. V. W. Palmer, both of the Paleontological Research Institu- tion, have given many valuable criticisms and suggestions throughout the entire course of this study. The Olsson collection of Miocene mollusks was very generously loaned by that institu- tion, and Mr. A. A. Olsson lent his unfinished manuscript of the Miocene mollusks of the Atlantic coastal plain. The writer is also indebted to Miss Mary Flynn of Bryn Mawr College for making the photographs included in this report, and to Mr. Edwin L. Kessler of Newtown Square, Pennsylvania, _for drawing the chart. INTRODUCTION The following paper presents a restudy of the Miocene mol- lusks of southern Maryland with particular emphasis on their stratigraphic relationship and distribution. Many of the larger mollusks from the Maryland Miocene have been known since the first half of the nineteenth century, when they were described by Thomas Say, T. A. Conrad, and others. In 1904 G. C. Martin and L. C. Glenn published a monographic study of the mollus- can faunas in the Miocene report of the Maryland Geological Survey. This report is now in need of considerable revision. Good, photographic illustrations are needed to replace the origi- nal drawings, and more adequate descriptions and comparisons of the species are conspicuously desirable. The Maryland Miocene report gives no detailed information on the stratigraphic distribution of even the more common spe- cies. Species are usually cited as occurring in the “Calvert for- 171 MaryLaNnp MroceENE: SCHOONOVER 7 mation’, or in the “Choptank formation”, with no clue as to which part, or parts, of the formation is meant. Actually, a species may occur in one bed, throughout an entire formation, or through- out parts of two formations. Usually it is impossible to tell which is the case from the information given, although anyone who has done field work in the Miocene of southern Maryland can make a good guess as to the stratigraphic horizon from which a certain species has come. For example, if a species is cited as occurring in the Calvert formation south of old Plum Point wharf, it most probably came from “zone 10”, since that is by far the most fossiliferous bed at that locality. This paper is limited in scope to the more purely stratigraphic aspects of the problem. Its chief contributions are the factual information presented in the lists of species and in the distribu- tion chart, and the detailed study of eleven genera of pelecypods. The species lists have been made as complete as possible for all of the localities and stratigraphic horizons visited by the writer. The chart of distribution shows the geographic and stratigraphic occurrence of the more important genera of pelecypods, as well as their relative abundance in each case. In this work, empha- sis has been placed on those genera which were found to have stratigraphic importance in the field. Both the distribution chart and the method of detailed study of the pelecypods will be con- sidered again in a later paragraph of this section. The collections of this report were made by the writer dur- ing the summers of 1936, 1937, and 1938, mainly from the west- ern shore of Chesapeake Bay in southern Maryland. Most of the localities are in Calvert County, a few are in St. Mary’s, and one is in Charles County. In Calvert County, collectin,: was done principally along, or near, the western shore of the Bay, which for thirty miles has a N-S or NNW-SSE trend. Chesa- peake Beach (Seaside) is the most northerly locality, and Drum Point the most southerly. The last, however, is in the St. Mary’s formation, with which this report is only indirectly concerned. More properly, then, Camp Boy Haven may be taken as the most southerly collecting ground. In the writer’s collecting only specimens in place, or in fallen blocks the source of which could nct be mistaken, were taken. = ee ee Deeeeeeeiand 8 BuLLETIN 94B 17 Lo A small collection of fossils was made from the Choptank for- mation along the south shore of the Potomac River in West- moreland County, Virginia. Although W. C. Mansfield has attempted to correlate these beds with the Maryland zones, their exact correlation has not been definitely established. For that reason, as well as on account of the small size of the writer’s collections, the Virginia fossils will not be discussed in detail. The localities in Calvert County are along a series of high, eastward-facing cliffs, which overlook Chesapeake Bay, and which extend almost continuously from Chesapeake Beach to Drum Point. The lower parts of the cliffs are readily access- ible, but the upper, stratigraphically higher, beds can usually be reached only where there are large fallen masses, up and over which one can climb. The constant and rapid wearing back of the cliffs, shown in the many falls and landslides, assures one of fresh exposures, and hence of unweathered fossils at many localities. In a few instances, fossils have been collected from localities a mile or less inland from the Bay. New roadcuts offer the best opportunities, but fossils sometimes are brought to the sur- face during the plowing of fields. After such artificial exposures are a few years old, the fossils in them disappear, probably through rotting and leaching by near surface waters. A few in- land localities mentioned in the Miocene report as exposing fos- siliferous beds are now completely barren. Similarly, Dryden (personal communication) reported that when he was working at Hollin Cliff on the Patuxent River in 1929 there were numer- ous fossils present on the surface. The writer visited the same locality (number 13 in this repert) in 1936 and again in 1938. The only fossils, aside from a few indurated blocks, which could be found at that time were obtained by digging a deep hole with a spade. The shells were all very rotten, and apparently in the process of being leached out. The chart, herewith inserted, represents an attempt to express graphically (a) the vertical range, (b) the horizontal distribution, and (c) the relative abundance of all the pelecypods which have been found to have stratigraphic or other importance in the field. Of these three groups of data, the last has been nv(e3 MaryLhAnp MiocENE: SCHOONOVER a a] im i ais i +e i i f a" 4 ii CHART q 10 1,213 14 15| 1 Undifferentiated ue Ud 18 !9 Chentence SPECIES "ZONE" [4] 5 Bh Abundant O Few GGMnay, ; ; = z ak OG TE a a 40\42|41\40|34|52|14|36| 4 |2 | 5 |i1\48\4 |13 Jo2\43|38 54|53|46\¢3145/26| |o3ealar|s7|zzlesla sal) } Go = = ; es /50}34|7 |10|54149150|33115|55|5I\60}22I/2/ | |ea|ao]si 2/61 Glycymeris parilis ‘Anadara_subrostrata I Anadara_staminea Z aisleiE aeleialsley Pecten _humphreysii Olx Amusium_cerinum x Chlamys coccymelus ge Chlamys_madisonius Chlamys madisonius var. near marylandicus x Chlamys_marylandicus an fale x Astarte_cuneitormis Astarte _cuneiformis var. obesa Astorte cuneiformis var. calvertensis B|x|x}O RINE x x x Led x x [0] ° ° x|x|O x |x @ SLoILuL i x|x|x |B x|x[*|@ Astarte_cuneiformis var. parma Astarte_thomasii fe} Astarte thisphila Astarte obruta Astarte exaltata Oo} _|O Evcrassatella_melina 98/@|0/8/0|B @|O O|x|x|x/@ fe) ® {e) x Eucrassatella_turgidula @/e| [olalelelol lelelolo I x] x Evcrassatella marylandica eee Saxolucina_foremani Saxolucina_anodonta fe) @ @ ®@ ® BO lo 5 {e) ® fe) Oo il fe) is) Lucinoma_contractus Diplodonta_acclinis Diplodonta_subvera Cardiym leptopleurum Ee Cardium craticuloide El Cardium laqueatum H x x Isocardia markdei Isocardia_mazlea ° bo eal ead Rad Rall ad x i) 2 fe) fe) x i Isocardia fraterna var. marylandica lg ° 2 i ole all OH) {5 olololis}o[o[olo[ofolo ° Isocardia_ignolea if x Antigona staminea @/O Chione_latilirata | I o|k Chione_parkeria O |e | Bai | Corbula_idonea a Corbula elevata 8 © Corbula inaequalis Corbula cuneata [| ele o|a * (eo) fe) | | x |S « {e) ie {o) © [e) fe) o C7) x fe) 6 @ fe) (e) (o} 2@|\9|8 @ (e) fo} e} Ke) T | f ( i \ f ; - r t enn ot seme oS, ae ee Ws MarynANnp MiocENE: SCHOONOVER 9 found to be much the most difficult of representation. The great- est source of error lies in the wide variation in the ratio of total mass of shell material to the mass of matrix in any given bed. In “zone 10”, a very fossiliferous bed, a species might be marked “few” or “rare”, but the same number of specimens found in a relatively unfossiliferous bed might cause one to mark that spe- cies there as being “common”. Consequently, the symbols for abundance of any species should be understood as being strictly comparable to one another for only the one particular bed in question. Of necessity, the personal element has loomed large in the making of this chart, and the final result represents no more than the writer’s best judgment at the time the chart was constructed. In the systematic descriptions of pelecypods, the method of treatment varies from group to group. The method which seemed best adapted to a clear presentation of the characters of a group has been used in each case. The principal aim has been to place emphasis on the relationships, both biologic and strati- graphic, of a group as a whole, rather than as a collection of sep- arate species. For example, comparisons have been made among the range, distribution, and variations of all the species of the Astartes taken as a group, rather than giving a treatment of them individually and separately. The method of study has been unusual only in the respect that it was based on exceptionally large suites of specimens. In each case in which detailed work is given in the systematic descrip- tions, the work was based on a study of several hundred speci- mens. For example, in the case of the Pectinide, the writer’s suites consisted of over 500 specimens. The writer has about 300 specimens of C. madisonius from zone 10 of the Calvert alone, and more than 300 specimens of Astarte from different horizons. All of the specimens of one species, or of several close- ly-related species, were spread out on tables at the same time. In this way they were most accessible for study and comparison. One result of the writer’s use of this method has been the erowing conviction that it is inadvisable to found species of fos- sils on a few unusual specimens. In many cases the range of variation in a species was found to be considerable. The ex- 10 BULLETIN 94B 174 tremes in any series of specimens could easily be selected as dis- tinct species. However, in suites the size of those with which the writer was dealing every intermediate gradation was also present. Since complete series between the extremes could be arranged, the writer has been very hesitant to give even the extreme varieties new names. She has preferred to describe them simply as members of the main stock which vary in certain given directions. In several cases she has taken forms described as senarate species by other authors and called them varieties of the n ~in stock. This wide range of variation is especially striking in the case of the Astarte cuneiformis stock, and in that of the Chlamys ma isonius stock. Several species of Astarte allied to Astarte cur iformis have been described by other authors, but for the reasons already given they are regarded here as varieties. In the case of the Chlamys madisonius stock several names have been applied to different variations. Even after an examination of the type specimens of some of these “species” the writer found it impossible to identify any of them positively among her col- lections. If they are at all common in the beds from which they were described, it could reasonably be expected that she would have found a few. The type specimens themselves are very sim- ilar to many forms in the writer’s collections, but every grada- tion between these forms and the more central ones commonly regarded as C. madisonius is present. It seems strongly inadvisable to burden the literature with new names for all the variations which can be recognized in so prolific a stock as, for example, Chlamys madisonius. Rather, it is sufficient for the present purpose to recognize that the forms do vary, both areally and stratigraphically, and to describe these variations. One group of variations in the C. madisonius stock, a variation which is described as approaching C. marylandicus, is illustrated on plates 2 and 3. These forms look quite distinct from typical C. madisonius as illustrated on plates 2, 4, and 5, and yet every gradation between them can be found. In the synonymy of species no attempt has been made to give complete references to all citations of each species. The original description and a few subsequent references which added some- 175 MARYLAND MIocENE: SCHOONOVER 11 thing of distinct value are the only ones included. Fuller synony- mies have already been given in the Maryland Miocene report, and there seems to be little need for repeating them here. The localities given for different species are those where the writer personally has found these species. The Maryland Mio- cene report summarized all the localities from which the differ- ent species had been reported up to the time of publication of that report, and little further work has been published since that time. Almost no attempt has been made to identify the gastropods more accurately than could be done by reference to the Mary- land Miocene volume. The writer is perfectly aware that many of the names used therein have since been revised, but the time involved in recognizing and applying such revisions as have al- ready been made makes such work impracticable at the present. However, it is believed that such revisions are not indispensable for the purposes of this work. It will be sufficiently clear if it is understood that the present writer’s reference to a species of gastropod is to that species as illustrated and described by Martin in the Maryland Miocene volume. The same remarks apply to many of the pelecypods. Effort has been made to apply revised names of pelecypods in cases where this did not involve an excessive amount of time-consum- ing, bibliographic research. Mistakes may easily have been made in the application of revised names, or the writer may have accepted others’ revisions without examining the evidence critical- ly enough. However, she feels that such mistakes are not too vital for the purposes at hand, and she prefers to rely on the judgment of paleontologists who have had extensive taxonomic experience. SIMRAT GIP NC The Miocene deposits in the Chesapeake Bay region form a broad band trending northeast to southwest from New Jersey, across Delaware, and the eastern and western shores of Mary- land, into Virzinia. In this report only that area of the Miocene lying in Maryland within the western shore counties of Calvert, St. Mary’s, and Charles will be considered, and especial atten- tion will be given to Calvert County. The Miocene beds of this alt BULLETIN 94B 176 area have been divided into three formations, Calvert, Choptank, and St. Mary’s, from oldest to youngest, respectively. The St. Mary’s formation is not the immediate concern of this report, though its stratigraphy and fossils will be mentioned incidentally. All of the beds have a very gentle south or southeast dip, so that the oldest formation is exposed farthest inland, and the younger ones outcrop successively in a more southerly or south- easterly direction. The best exposures of the Miocene in ail the Chesapeake Bay region are those of the Calvert Cliffs, known in the literature for well over a hundred years. In the thirty- mile stretch of the cliffs from Chesapeake Beach to Little Cove Point, the Miocene beds can be traced almost uninterruptedly. Probably less than a sixth of the entire distance is taken up by low-lving areas and valleys where tributary streams enter the bay. This area has become a favorite place for the summer cot- tages of people living in Washington, Baltimore, and nearby places. As a result, reasonably good roads lead to the water7) iv front at intervals seldom exceeding two or three miles. The most difficult portions of the cliffs to reach are the stretches be- tween Long Beach and the Cove Point lighthouse, and between Cove Point and Little Cove Point. Even here there are private roads by which one can reach the cliffs. The lower part of the Calvert formation is exposed in the northernmost cliffs near Fairhaven in Anne Arundel County, and near Chesapeake Beach in Calvert County. The upper part outcrops from a short distance south of Chesapeake Beach to the mouth of Parker Creek . The Choptank formation is exposed best in the stretch between the mouth of Parker Creek and a short distance north of the Cove Point lighthouse, and the St. Mary’s formation is well exposed near Little Cove Point. The latter formation is found from north of Cove Point lighthouse to Drum Point, but it is most fossiliferous over a stretch near Little Cove Point. An historical summary of work relating to the Maryland Miocene is given in the Miocene report of the Maryland Geologi- cal Survey, and will not be repeated here. The first detailed subdivision of the section into zones was made by G. D. Harris? 1 Harris, G. D.: The Tertiary geology of Calvert Cliffs, Maryland; Am. Jour. Sci., 3d ser., vol. 45, 1893, pp. 21-31. ( 177 MaAryLANdD MIocENE: SCHOONOVER 13 in 1893. Harris recognized what he called the Plum Point fauna, the Jones’ Wharf fauna, and the St. Mary’s fauna, and gave the more fossiliferous beds letters from a to g. In the Miocene report of the Maryland Geological Survey G. B. Shattuck divided the formations into numbered zones. The most abundantly fossiliferous beds correspond to Harris’s let- tered zones, but the less fossiliferous, intermediate beds are sub- divided further. The Calvert formation includes zones 1-15, the Choptank zones 16-20, and the St. Mary’s zones 21-24. The zones of the Calvert formation are grouped as two members, the Fairhaven diatomaceous earth, comprising zones 1-3, and the Plum Point marls, comprising zones 4-15. Zone 4, or the Ostrea percrassa bed, of the Miocene report corresponds to Harris’s zone a, zone 1G to zone b, zone 14 to zone d, zone 17 to zone e, zone 19 to zone f, and zone 22 to zone g. The Fairhaven diatomaceous earth does not carry many fos- sils. Those present are usually preserved as casts, or the shell substance is so rotten that it is practically impossible to collect them or to identify them accurately. Consequently it has been necessary to omit the Fairhaven diatomaceous earth from con- sideration in this paper. Many of the “zones” recognized by Shattuck and the Mary- land Geological Survey are not true paleontologic zones”, but rather, beds. The principal shell beds are the only ones which could be designated as true paleontologic zones. Those beds which Harris designated as zones conform much more nearly to the definition of a paleontologic zone than do the intervening ones which were numbered by Shattuck. Of the zones desig- nated by Harris, zone d, or zone 14, is the only one which is probably not a paleontologic zone. Some of Shattuck’s zones cannot be identified in the field. This is particularly true of the beds between the oyster bed, zone 4, and the thick shell bed, zone 10, and between the top of zone 10 and the bottom of zone 17 of the Choptank. Zones 5-9, in- clusive, were differentiated on the basis of the relative abundance 2 For a discussion of paleontologic zones, see Arkell, W. J:: The Ju- rassic system in Great Britain, Oxford, Clarendon Press, 1933, pp. 17-19. 14 ie BULLETIN 94B 178 of the pelecypod, Corbula elevata. Even in the type locality it is almost impossible to recognize these zones. They are not well Cefined, and one must do considerable guessing to delimit them even where they were described. They have not been identified in any but this one locality. For the purposes of this report, then, zones 5-9 should be regarded as one bed. In the locality lists, and in the lists of occurrence of species these zones were given with question marks. The only reason or advantage in doing this was to show relative position within the bed composed of “zones” 5-9, and to make possible some comparison with Shattuck’s divisions. Otherwise the entire thickness should be rezarded as a single unit. The beds between zones 10 and 17 lend themselves somewhat more readily to subdivision. Zones 11 and 13 can be recognized over a considerable stretch of the cliffs as dense clay layers with prismatic jointing. Zone 12, between them, is a thin, sandy layer carrying quite a few fossils. The fossils are poorly preserved, and none were collected by the writer. However, this layer has yielded more vertebrate remains than any other bed. Zone 14 can be recognized best in the area between Parker Creek and Governor Run. Further north it is present, but it is so high in the cliffs that it is usually inaccessible. It can only be identi- fied there by the fact that it carries more fossils than the enclos- ing beds. As one looks up at the higher portion of the cliffs zone I4 stands out as a band of shells. It is, however, never distinctly marked off from the enclosing beds. The only way the writer has ever found of delimiting it is by the relative rarity of fossils. There is no marked lithologic change, and the fossils do not stop abruptly, either above or below it. The beds between zone 14 and zone 17 are even more diffi- cult to differentiate. The writer has recognized zone 16 only in the area just north and south of Calvert Beach. Even here the bottom of the zone is not exposed. Elsewhere is seems im- possible to differentiate the beds between zones 14 and 17. The writer has never been able to identify the supposed Calvert-Chep- tank unconformity, which should lie between zones 15 and 16, according to the Maryland Miocene report. In that report it 1s stated that the unconformity can best be seen from a boat in the area north of Governor Run. The writer has gone by boat alons 179 MaryLANp MioceENE: SCHOONOVER 15 the stretch from Dares Beach to Parker Creek, and from Gov- ernor Run to Parker Creek, but never could she recognize any- thing to call an unconformity. At one locality less than half a mile north of Scientists’ Cliffs a colony of the echinoid, Echinocardium orthonotum, was found about 18 feet above water level, or about 2-3 feet above the top of zone 14. It is possible that this colony marks the “unconform- ity”, but there is no proof that it does. As previously mentioned, most of the localities from which the material used in this report was collected occur along a north- south, or linear, section. Very little is known about the extent of any of the Miocene beds, except the Fairhaven diatomaceous earth, inland from the Calvert Cliffs. Zone 10 is present at Hollin Cliff, localities 13 and 62, almost nine miles inland, and at the “Old Walls Place’, locality 9, in Charles County, about 1114 miles west of the Bay shore. The Choptank formation with its fossiliferous beds, 17 and 19, is present near Jones Wharf on the Patuxent River in St. Mary’s County, about nine miles di- rectly west of the Bay shore in Calvert County. These are al- mest the only localities at which the zones described from the cliffs have been identified at any distance back from the Bay shore. The zones cannot be identified on the basis of lithology alone, and at most inland localities the fossils have been destroyed by rotting or leaching. SVS EVAICy DESECRiE MONS Phylum MOLLUSCA Class PELECYPODA Order PRIONODESMACEA Family GLYCYMERID: Genus GLYCYMERIS da Costa Glycymeris parilis (Conrad) Plate 1, figs. 1, 8 Pectunculus parilis Conrad, 1843; Acad. Nat. Sci. Philadelphia Proc., vol. 1, p. 306; 1845, Fossils of the Medial Tertiary, p. 64, pl. 36, fig. 2. Glycymeris parilis (Conrad). Glenn, 1904, Maryland Geol. Survey, Mio- cene, p. 393, pl. 107, figs. 1-2. Conrad’s original description—Orbicular, slightly oblique; height and length equal; posterior superior margin obliquely subtruncated; ribs de- 16 BULLETIN 94B 180 fined by slightly impressed narrow radii; radiating striae minute and ob- solete; marginal. teeth prominent. This is the only species of Glycymeris the writer has found in the Maryland Miocene. It is very abundant and characteristic of zone 10 of the Calvert, and so far has not been observed in any other bed. Even if future collecting should yield a few spec- imens from other beds, the species will remain a reliable mark- er for zone 10. Whenever it is found at all abundantly, one can be certain he is dealing with that zone. This species commonly occurs in bands several inches thick within the main fossil zone. In these bands there are few other fossils ; indeed, the shells are so closely packed together that the amount of sandy matrix is small. More than half of the speci- mens in these bands have the two valves still articulated, and the bands doubtless represent communities still in the position in which they lived. The bands are particularly well developed at a locality just north of Randle Cliff Beach, though they may be found almost everywhere zone 10 is exposed. Dall reported G. americana from the Miocene of Calvert and Charles counties, Maryland, but this occurrence has not been verified, and it seems very questionable. This species is char- acteristic of the Upper Miocene in Virginia and North and South Carolina, of the Pliocene in North Carolina and Florida, and of the Pleistocene in South Carolina. It was not reported by Glenn from Maryland. Glycymeris subovata (Say) is characteristic of the Yorktown and Duplin Miocene in Virginia, North and South Carolina. It was reported by Glenn from the Choptank formation at Greens- boro, in Caroline County, Maryland, and at Davis’s Mill on the Choptank, near Skipton, in Talbot County. In the collection of type and figured specimens of the Maryland Geological Survey at Johns Hopkins University there are two specimens labelled Glycymeris subovata Say, from Greensboro, One of these is figured as figures 3 and 4, plate 107 of the Maryland Miocene report, and the other is not figured. These two specimens are preb- ably immature, but they are definitely different from G. parilis. The shell is thicker, more inflated, and longer in proportion to the 181 MARYLAND Mi0ocENE: SCHOONOVER iy height. The ribbing consists of narrow impressed lines, with the interareas very gently convex. However, these two specimens do not correspond to specimens of G. subovata of similar size from Virginia. Young specimens of G. subovata are thinner and flatter. These two specimens seem to correspond most closely to young specimens of a new, undescribed species from the St. Mary’s of Virginia, referred to by Mansfield (Florida Geol. Survey Bull. 8, page 40) as be- ing very similar to G. waltonensis Gardner from the Shoal River formation of Florida. Aside from these two specimens, the writer has never seen any specimens of Glycymeris from either the Choptank or St. Mary’s formations in Maryland. If the genus is present in either of these, it is only as rare specimens, and it is not characteristic. Of the three species, G. americana, G. subovata, and G. parilis, G. parilis averages the most convex, the greater convexity being particularly noticeable in the central region just below the um- bones. Many specimens of G. americana and G. subovata seem to be of about equal convexity, though some series of G. subovata tend to be flatter. In typical specimens the outline of the shell varies rather con- sistently in the three species. It is most nearly circular in G. subovata. In all three the greatest length of the shell is just ven- tral to a line connecting the outer ends of the hinge plate. The hinge plate, especially the central portion, is most strongly arched in G. subovata, least strongly in G. americana. It is intermediate in G. parilis. In G. americana the length is greater in proportion to the height, and the greatest length is confined to the dorsal half of the shell, after which it narrows down ventrally more rap- idly than in the other two species. The character of the ribbing in the three species is distinct. In G. subovata the ribs are fewer and broader. They are set off by sharply impressed lines, and the ribs between the lines are gently convex. In G. parilis the lines are more numerous but not so deeply impressed, and the ribs between the lines are flat. The ribs on G. parilis are not so apparent. In G. americana the impressed lines are still less distinct, and the ribs are almost flat. Each rib is crossed by very fine radiating strie. 18 BuLLETIN 94B 182 Figured specimens.—Nos. 3909 and 3915, Paleontological Re- search Institution. Horizon.—Zone 10, Calvert Miocene. Localities.—1, 36, 4, 2, 5, 3, 48, 9. Family ARCIDA Ten species of Arcidz were reported by Glenn from the Mary- land Miocene, but of these only four are abundant enough or distinct enough to be useful in stratigraphic field work. One of these occurs in the Calvert formation, one in the Choptank, and two in the St. Mary’s. The species which Glenn gave, and their stratigraphic occurrences are listed below. The species which are here regarded as of stratigraphic importance are marked with asterisks. Calvert formation *Area (Scapharea) subrostrata Conrad Arca (Barbatia) centenaria Say Area (Barbatia) marylandica Conrad Choptank formation Area (Scapharea) elnia Glenn *Area (Seapkarea) staminea Say Area (Noétia) incile Say Arca (Barbatia) centenaria Say St. Mary’s formation Area (Seapharea) clisea Dall *Arca (Scapharea) arata Say *Area (Scapharea) idonea Conrad Area (Barbatia) virginie Wagner Several of the species listed here are rare, or the report of their occurrence in Maryland was probably a mistake, so they may ‘be dismissed with a few remarks. Glenn reported Arca (Barbatia) centenaria from both the Calvert and Choptank for- mations. It must be rare, however, since I have never found a single specimen. It is much more characteristic of the York- town Miocene of Virginia than of the Maryland Miocene. Arca (Barbatia) marylandica occurs in the Calvert formation, probably in zone 10, but is also quite rare. W. C. Mansfield spoke of its being fairly common in zone 10 (personal communi- cation), but I have failed to find a single specimen. Consequent- ly no further information as to its range can be given here, though it seems likely that it is limited to zone 10, 183 . Marytann Miocene: ScHoonover 19 Arca (Scapharca) elnia was described by Glenn from Jones Wharf, zone 17 at Governor Run, and 2 miles south of Gov- ernor Run. It was described as a species intermediate be- tween Al. staminea and A. subrostrata. This seems to be an- other rare, and not too distinct, species. I have collected one specimen only, which came from zone 10 of the Calvert forma- tion from locality 28, south of Plum Point. Arca (Noétia) mcile was reported from Maryland, but this was probably an error, as noted by MacNeil?. MacNeil says, Dall and tae Maryland Geological Survey reported FH. incile in the Burns and Harris collection from the Caoptank formation at Jones Wharf, Md. Tnis was evidently an error, as the specimens of this species in the Burns snd Harris collection in the United States National Museum are recorded in the locality catalog as having come from Virginia and are like speci- mens from Rushmere Wharf in form and preservation. No collections from Maryland have contained any specimens of Hontia, to my knowledge. I have not definitely identified any specimens of Arca (Scaph- arca) clisea from Maryland. Specimens of Arca from the St. Mary’s formation at Langley’s Bluff (locality 37) differ from the typical forms of A. idonea found on the St. Mary’s River. They possess some characteristics belonging to 4. staminea of the Chop- tank, and approach A. clisea in other respects. Their exact po- sition and relationship have not yet been determined. The occurrence of Arca (Barbatia) virginie in Maryland can be neither confirmed nor denied, but it is a rare species and much more characteristic of the Virginia Miocene. In the Mary- land Geological Survey collections there is one much worn spec- imen labelled “Arca virginize Wagner’, from “St. Mary’s, Md.” It is marked “Fig’d.”, but is not the specimen figured in the Maryland Miocene report. It is a right valve, and is Arca arata, net A. virginia. The figure in the Maryland Miocene report is that of the exterior of the left valve of a type specimen, and the specimen should be in the Wagner Free Institute of Science. There now remain for consideration only four species of Arcas which are regarded as of real stratigraphic value. Two of these occur only in the St. Mary’s formation, and so do not belong 3 MacNeil, F. S.: Species and genera of Tertiary Noetine, U. S. Geol. Survey Prof. Paper 189-A, 1938, p. 15. MacNeil assigned Arca incile to the new genus Hontia in this paper. 90 BULLETIN 94B 184 strictly within the scope of this report. These are A. arata and A. idonea. They both occur on the St. Mary’s River and at Langley’s Bluff. A. 1.’onea is much less common at Little Cove Point than at the other two localities where the St. Mary’s forma- tion outcrops. The two remaining species are 4. subrostrata, which is con- fined to zone 10 of the Calvert, and A. staminea which occurs in zones 16-19, inclusive, of the Choptank. There appear to be no Arcas in any part of the Calvert formation except zone 10. Arca subrostrata is very common at practically every locality where this zone is found. Its absence from any of my localities for zone 10 is probably due to collection failure. circa staminea was found in zone 16 at one locality (23, N. of Calvert Beach). It is common in both zones 17 and 109, at al- most every locality where they occur. It is common in zone 18 at locality 49, north of Scientists’ Cliffs. At this place there is a thin band consisting almost exclusively of Arcas in clay at an elevation of 4914-52 feet above high tide, or 11 feet above the top of zone 17. At an elevation of 56-5714 feet there is another band of fossils in which Arca staminea is common. This band is about 314 feet below the bottom of zone 19. Within the principal shell beds (zones 10, 17, 19), both these species of Arca characteristically occur in thin bands consisting almost exclusively of a single species. The valves usually re- main attached. Apparently the species were gregarious, and these bands represent colonies which were not washed about by waves or currents before burial. The individual bands cannot be traced any great distance (probably not more than a quarter of a mile), and they recur at different horizons within the shell beds at different localities. The individual bands appear to be more extensive in the Choptank than in the Calvert formation. In general, Arca subrostrata can be regarded as a good index fossil for zone 10, and Arca staminea for the entire Choptank formation. The two species can be separated easily according to the characters indicated in the following key: 185 MaryLAND MiocENE: SCHOONOVER 91 Elongate Hibs flattened, not noded, bearing radial sulci, usu- ally one strong medial suleus, with one or more shal- OWE! OMS Oil GAC SUC oer peceereccnesontonenneoswssssesneeaceocecias Arca subrostrata Not elongate Ribs elevated, rounded, often noded; radial sulci limited to one, if any on each rib Arca staminea Subfamily ANADARINZ Reinhart Genus ANADARA Gray Anadara‘ subrostrata (Conrad) Plate 1, figs. 2-4 Arca subrostrata Conrad, 1841, Acad. Nat. Sei. Philadelphia Proe., vol. 1, p. 30; 1842, Acad. Nat. Sci. Philadelphia Jour., Ist. ser., vol. 8, pt. 2, p. 185; 1845, Fossils of the Medial Tertiary, p. 58, pl. 30, fig. 7. Arca (Scapharca) subrostrata Conrad. Glenn, 1904, Maryland Geol. Sur- vey, Miocene, p. 385, pl. 104;-figs. 2, 3a, 3b. Arca swbrostrata Conrad. Sheldon, 1917, Paleontographica Americana, vol. i, No. 1, p. 51, pl. 12, figs. 1-4. Conrad’s original description.—Ovate; profoundly ventricose; ribs about 30, little prominent, flat, longitudinally suleated; posterior side produced, cuneiform; rounded at the extremity; hinge linear in the middle, teeth obsolete, except towards the extremities; within slightly suleated; crenu- lations of the margin suleated in the middle. Length 2 inches. Specimens from localities 35 and 36, north and south of Randle Cliff Beach, average slightly larger than those from other locali- ties, Young specimens are commonly less elongate than the adult shells, and occasionally are very similar in general shape and outline to A. staminea. A. subrostrata is usually thinner- shelled than A. staminea. The ribs on A. subrostrata only verv rarely bear nodes. Figured specimens.—Nos. 3910-3912, Paleontological itesc. Institution. Horizon.—Zone 10, Calvert Miocene. Localities —35, 36, 2, 5, 3, 48, 13, 9. Anadara staminea (Say) Plate 1, figs. 5-7; plate 2, fig. 4 Arca staminea Say, 1832, Amer. Conch., part 4, pl. 36; fig. 2. Arca elevata Conrad, 1840, Fossils of the Medial Tertiary, No. 1, cover. 4 According to Reinhart’s classification (1935), this and the follow- ing species, A. staminea, should be assigned to the genus Anadara. In the foregoing discussion the list of species was quoted from the Maryland Miocene report, and it seemed best to retain Glenn’s terminology for all of the species for the sake of clearness in that discussion. Henee, Arca subrostrata and Anadara subrostrata are the same species, as are Arca stammea and Anadara staminea. he) BULLETIN 94B 186 Arca callipleura Conrad, 1840, Fossils of the Medial Tertiary, p. 54, pl. 9 yeti ae Area triquetra Conrad, 1843, Acad. Nat. Sci. Philadelphia Proe., vol. 1. p. 305. Arca (Scapharca) staminea Say. Glenn, 1904, Maryland Geol. Survey, Miocene, pp. 387-88, pl. 105, figs. 2-6; Sheldon, 1917, Paleontographiea Americana, vol. 1, No. 1, pp. 39-40, pl. 9, figs. 7-13. Say’s original description—Shell thick, prominently convex; with about twenty-eight ribs which are rounded and narrower than the intervening spaces, excepting on the anterior side, where they are broader, and simply wrinkled, those of the anterior part of the disk have one or two longitudi- nal impressed lines; they are crossed by numerous transverse, elevated lines, which are hardly more distant from each other than their own width; in- tervening spaces wrinkled: beaks distant, curved a little backward, and the tip a little behind the middle of the hinge margin; area flattened, a little curved, rather spacious, with obvious impressed, oblique lines: hinge mar- gin rectilinear, with small, numerous teeth: posterior margin regularly arcuated: base subrectilinear, very deeply crenated: anterior margin oblique, rectilinear; anterior side abruptly compressed. This species is thicker-shelled than A. subrostrata. The ribs are more elevated and rounded, and the nodes are much more commonly developed, though they are not present on all speci- mens, The radial grooves are limited to a single groove on each rib. Specimens show some variations in different beds and differ- ent localities. In general, specimens from zone 19 have a diame- ter which is greater in proportion to other dimensions of the shell than in those from zone 17. The latest growth of the shell takes place along all margins at an angle approaching a right angle to the plane between the valves. The cardinal area is ac- cordingly widened. This gives a much inflated shell, with a diameter greater in proportion’ to its other dimensions than in shells from zone 17. The Jones Wharf specimens are less inflated, their cardinal area is narrower, the shell substance less thickened, and the out- line is less squarely compressed anteriorly and posteriorly. The same is true of specimens from locality 44, north of Long Beach, and from locality 25, south of Calvert Beach. It is not so strik- ing in specimens from locality 27, north of Calvert Beach, or from locality 56, south of Flag Pond. These specimens show considerable variation, with some shorter, higher, and more in- flated forms than from zone 17 at other localities. Individual specimens probably could not be separated from those of zone 187 Maryann MioceNnn: ScHOONOVER 23 19, but a suite of specimens from zone 17 is less consistent in shape and outline and could probably be separated. Specimens from zone 19 seem to have sharper angles at the junction of the anterior and dorsal, dorsal and posterior, posterior and ventral margins. Some of these variations have been described as separate spe- cies, as noted by Sheldon and Glenn. Glenn said, “A careful comparison of what are doubtless the type specimens of A. callipleura shows that it is but a short, elevated, thickened, and well sculptured form of A. staminea.” Sheldon added, “A. tri- quetra Conrad is a short, high and little sculptured form of A. staminea.” The specimens from zone 18 apparently belong to the short, high type of zone 19. The sulcus Sheldon spoke of as being just anterior to the umbonal ridge is not very noticeable in any of my specimens, and is entirely absent from the short, high forms characteristic of zone 19. Figured specimens.—Nos,. 3813, 3914, and 3919, Paleontolog- ical Research Institution. Horizons.—Zones 16-19, inclusive, Choptank Miocene. Localities.—23 ; 59, 6, 10, 21, 27, 25, 44, 56; 50, 49; 33, 55, 15. Family PECTINIDE Four groups of Pectinidz are present in the Calvert and Chop- tank formations of southern Maryland. ‘Two of these are repre- sented by relatively rare specimens, but they are so distinct that they could not be confused. These two groups are Pecten, s. S., represented by Pecten (Pecten) humphreysu Conrad, and Amu- sium, represented by Amusium (Pseudamussium) cerinum (Con- rad). The first of these occurs in the lower part of the Calvert formation, zone 4 up through zone 10, but has not been recorded from any beds above zone 10. The second occurs chiefly in zone 10. I also collected one specimen from zone 6? north of Randle Cliff Beach. The species was reported by Glenn from the Chop- tank formation at Jones Wharf, but with the exception noted here I have not seen specimens from any beds other than zone 10 ot the Calvert. 94 BULLETIN 94B 188 The third group is included in the subgenus or section Placo- pecten, and is represented by Chlamys (Placopecten) maryland- icus (Wagner). This species is fairly common in zone 17 of the Choptank formation, and so far as I am aware no authentic spec- imens have been recorded from any other bed. A few specimens from the Calvert formation have been found which would be taken for C. marylandicus at first glance, but they are not identical. Some series of C. madisonius from the Choptank show variations in the direction of C. marylandicus, but these can always be separated from the true C. marylandicus. The fourth group is that of the subgenus Lyropecten. It is by far the most common group of Pectens in the Maryland Miocene, and its chief representative, C. madisonius, is also one of the most common mollusks. C. madisonius might better be regarded as a stock or lineage than as a species, because of its many variations. Several species and subspecies belonging to this stock have been described, but they are all so similar that they are difficult to differentiate. The species and subspecies which have been de- scribed from the Calvert and Choptank formations are shown in the following chart. Pecten (Pecten) humphreysii Conrad Plate 2, figs. 1-2 Pecten Humphreysti Conrad, 1842, Proc. Nat. Inst., Bull., vol. 2, p. 194, pl. 2, fig. 2. Vola Humphreysti Conrad. Whitfield, 1894, U. S. Geol. Survey Mon. 24, p. 32, pl. 4, figs. 6-9. Pecten (Pecten) humphreysii Conrad. Glenn, 1904, Maryland Geol. Sur- vey, Miocene, p. 372, pl. 98, figs. 10-12; Tucker, 1936, Am. Midland Naturalist, vol. 17, No. 2, p. 478, pl. 3, fig. 3, pl. 4, fig. 10. Conrad’s original description.—Suborbicular, inferior valve convex; su- perior flat, and with about seven remote, narrow, convex ribs, and concen- trically wrinkled; towards the apex is a concave depression; ears equal, sides direct and straight; inferior valve with the ribs wide, approximate, plano-convex and longitudinally striated; one of the ears emarginate at the base. This species is never very abundant, but careful collecting will usually yield a specimen or two from the beds between the oyster bed and zone 10, and from zone to itself. In Maryland the species is apparently limited to these beds, and has never been reported from above zone 10. It is a very distinct species, and could not be confused with any other, 25 SCHOONOVER MaryYLAND MIOCENE: 189 Be aS | su dH ors) an oS 83 | Be Py=) ne 7) A, z | ale | SN TeWAD000 RO ; SONTUBOe BNTUOST peu tom, JiIoTsseq snTuoSsTpeuU eli ejieumques —1t-----+-s °g3“snquostpeu ! a i A, I q | | | | od o ) oa z Se ! | a @ & & (0) Se O ! I ° ao woo | Gq om | sa a, a | | 3 | | Kr itieiien S:AUVA “LS | ANVLAOHO y LUBA TVO 26 BULLETIN 94B 190 Figured specimens.—Nos. 3916 and 3917, Paleontological Re- search Institution. Horizon.—Zones 4-10, Calvert Miocene. Localities—41, 40a, 52, 39; I, 36, 5, 3, 48, 13, 62, 9. Chlamys (Placopecten) marylandicus (Wagner) Plate 3, figs. 4-5 Pecten marylandicus Wagner, 1839, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 8, p. 51, pl. 2, fig. 2 (numbered fig. 2 on plate, fig. 1 in text). Pecten (Placopecten ?) marylandicus Wagner (nart). Dall, 1898, Wag- ner Free Inst. Sci. Trans.. vol. 3. pt. 4, p. 728. Pecten (Chlamys) marulandicus Wagner. Glenn, 1904, Maryland Geol. Survey, Miocene, p. 376. pl. 99. fig. 6. Chlamys (Placonecten) marulandicus (Wagner). Tucker-Rowland, 1938, Mus. roy. Hist. nat. Belgique, Mem., 2d ser., fase. 13, p. 54, pl. 4, ier, WB, joll, %, wie, iG. Wananer’s oriainal descrintion.—Shell ovate. compressed: ribs numerous. con~istine of narrow. nearly smooth strie. disnosed in pairs; interstitial spaces each with a carinated line: ears uneanal; inferior valve very slichtly corvex: ribs similar to those of the opposite valve; inner margin of the valve with profoundly elevated lines. Locality. Meherine river, North Carolina. This Pecten is allied to Pecten Madisonius, Say. but ean readily be distinonished by its want of broad. elevated rihs. and a surface destitute of scales: several snecimens of Spirorbus nautiloides, Lam., are attached to the surface of the superior valve. Waener’s locality was probably wrones. since the species is known only from the Choptank formation of Marvland and Vir- sinia. In the Philadelphia Academy there are two travs of C. marnlondicus, each trav containing three specimens. So far as the present writer can determine. either or both of these could have been Waecner’s original material. In one trav there are two labels. one saving “Patuxent River. Marvland’”’. which is probablv correct. and the other “N. Car. Pliocene ?”, which must be a mis- take. Tn the second trav no locality is given. Waener’s original fisure was of a left valve. but the drawine was extremelv poor. Tt would be difficult to determine the species from the drawings, and one could never identify the specimen from which the drawine was made. A right valve in the first trav hears several specimens of Spirorbis and may he the specimen to which reference was made in Wagner’s description. A penciled note inside the shell indicates that this should be the specimen figured, 191 MaryLANp MiIocENE: SCHOONOVER 27 but this is a right valve, and the one figured was a left valve. A second specimen in this tray corresponds in size with the orig- inal figure. Mrs. Tucker-Rowland selected a right valve from the second tray as one which she thought might be the holotype. If a holo- type existed, it would have to be a left valve, because the original figure was of a left valve. Mrs. Tucker-Rowland indicated that the specimen she chose was from the type locality and was iden- tified by Wagner, but no locality is given in the tray with that specimen, and it is very questionable whether any of these speci- mens actually came from the Meherrin River, North Carolina. Mrs. Tucker-Rowland gives measurements for the “holotype” as height, 76, width, 69 mm. Wagner gave no measurements, and the measurements above appear to have been taken from the specimen figured by Mrs. Tucker-Rowland. However, the width is not the maximum width for that specimen, the maximum being 77mm. If one is to give any measurement other than the maxi- mum for the width or length of a Pecten, that measurement has almost no meaning because it can be varied so as to yield any value from the maximum down to zero. True Chlamys marylandicus occurs only in the Choptank for- mation, and, so far as this writer has observed, only in zone 17 of the Choptank. It occurs in the Choptank of the Nomini, Strat- ford, and Horsehead Cliffs of Virginia, but the Choptank has not been well differentiated as to zones in these localities. The ribbing of C. marylandicus is its most distinctive feature, and it usually serves to differentiate it from other Maryland Miocene Pectens at a glance. The ribbing consists of radial lines which tend to group themselves into major ribs of varying degrees of prom- inence. In true C. marylandicus the lines occur in pairs, each pair alter- nating with a single line. All the lines are about equidistant, but the paired lines are slightly more elevated than the intervening single line, and so form a slightly elevated major rib. This major, exterior ribbing is reflected on the interior of the shell. Toward the ventral margin of the largest specimens another faint line may appear between the paired lines; also one on each side of the major rib at its base, The exterior of the shell is 28 BULLETIN 94B 192 covered by an extremely fine concentric sculpture which extends between the radial lines but does not cross them. Several series of specimens of C. madisonius from the Calvert (locality 40, zone 4, south of Randle Cliff Beach; locality 62, zone 10, Hollin Cliff) and Choptank (Jones Wharf, Md., and Stratford Cliffs, Va.) formations show striking similarities to C. marylandicus and could at first be mistaken for that species. These forms have similar radiating lines, but they are not so evenly spaced. Groups of three, instead of two, alternate with a single line, and the ribs formed by the three-groups are often more elevated than the similar ribs in C. marylandicus. The spaces between the lines of the three-groups are narrower than those hetween these eroups and the sinele lines of the interareas. The ceneral appearance of the two shells is such that in true C. mary- lancicus the effect is that of a relatively smooth surface with many radiating lines. In the variety the major ribs are more prominent, aid the appearance is that of C. madisonius without the scaly structure. Both C. marylandicus and the variety of C. madisonius are illustrated on plate 3. Figured specimens.—Nos. 3925, 3926, Paleontological Research Institution. Horizon.—Zone 17, Choptank Miocene. Localities.—27, 25, 7, 6, 50. Chlamys (Lyropecten) madisonius (Say) Plate 2, figs. 3, 5-6; Plate 3, figs. 1-3, 6; Plate 4, figs. 1-4; Plate 5, figs. 1-3 Pecten madisonius Say, 1824, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 134; 1896, Harris Reprint, Bull. Amer. Paleont., vol. 1, No. 5, a 40; Conrad, 1840, Fossils of the Medial Tertiary, p. 48, pl. 24, fig. 1. Pecten (Chlamys) madisonius Say. Glenn, 1904, Maryland Geol. Survey, Miocene, p. 377, pl. 100, fig. 1. Chlamys (Lyropecten) madisonius (Say). Tucker-Rowland, 1938, Mus. roy. Hist. nat. Belgique, Mem., 2d ser., fase. 13, p. 9, pl. 1, figs. 1-2; pl. 4, fig. 8. Say’s original description.—Much compressed, with about sixteen striated ribs. Shell rounded, much compressed; the whole surface covered with scaly striae: ribs elevated, rounded, with about three stria on the back of each; intervening grooves rather profound: ears equal, sinus of the ear of the sunerior valve profound, extending at least one third of the length of the ear. 193 MaryLANpD MiocENE: ScHOONOVER 29 Length rather more than four inches and a half; breadth four inches and four-fifths. In magnitude this shell is justly entitled to compare with the preceding (P. jeffersonius) ; but it differs in being much less convex, and in having a much more profound sinus in the ear of the superior valve. Three spee- imens, from which the above description was taken, belong to the Academy, end were presented by Mr. Watson. Mrs. Tucker-Rowland figured and described a young specimen from the U. S. National Museum which she thought might be the holotype, though she did not indicate why she chose this specimen. She gave as dimensions of this specimen height, 46 mm., width, 41 mm. In his original description Say gave the dimensions as length over 444 inches (114 mm.), and breadth, 4 4/5 inches (122 mm.). If any holotype exists it would have to have those dimensions, Say’s specimens should be in the Academy of Natural Sciences of Philadelphia. His original description indicated that it was based on three specimens. Search in the Academy has failed so far to locate these specimens. The only specimen with Say’s label is not C. madisonius, but probably C. jeffersonius edgecomb- ensis. The label indicates that the specimen came from St. Mary’s River, Maryland, but this is probably a mistake, and it more likely came from Virginia. The specimens figured by Mrs. Tucker-Rowland (pl. 1, figs. 1-2) as C. madisonius probably did not come from the St. Mary’s formation, on St. Mary’s River, Maryland, but from the Chop- tank formation. Although I have not seen the actual specimens, the illustrations are typical of Maryland Choptank torms, and I have not seen specimens like Mrs. Tucker-Rowland’s from the St. Mary’s formation anywhere in Maryland. C. madisonius is one of the most characteristic species in the Maryland Miocene. It occurs throughout the Calvert and Chop- tank formations, but not in the St. Mary’s. The species shows many variations in different beds and in different localities. The chief variations which can be observed relate to the following characters :—size, length-height ratio, thickness of shell sub- stance, degree of prominence of the scaly sculpture ; distance from the beak at which the scaly sculpture begins ; number and prom- inence of major ribs; number of radial striz; the angle from the umbo to the anterior and posterior margins; degree of concavity of the dorsal slopes from the umbo. 30 BULLETIN 94B 194 The literature dealing with the occurrence and characteristics of this stock is fairly extensive, but it occurs in scattered publi- cations and in such unorganized form that it is difficult to under- stand and to use. Four species or subspecies of the madisonius stock have been described from the Calvert formation: madisonius (Say), Ss. Ss. madisonius bassleri Tucker-Rowland, 1938 madisonius acanikos (Gardner) Tucker-Rowland, 1938 coccymelus (Dall), 1898 careful study of many specimens from different localities indicates that there are two more groups not included among these, which deserve recognition. One of these is a group re- sembling C. marylandicus but distinct from that species and show- ing transitional stages from C. madisonius. The other group is a small, thin, flat variety of C. madisonius found abundantly in zone ro at the north end of the Calvert Cliffs, near Randle Cliff Beach, and becoming progressively more rare away from that locality. It is impossible to state whether any of the Maryland Calvert forms are really identical with C. acanikos Gardner from the Chipola Miocene of Florida, because of lack of adequate material from Florida for comparison. Mrs. Tucker-Rowland regarded C. acamikos Gardner as a subspecies of C. madisonius Say, and stated that it is rather common at Plum Point. The Florida form is certainly very close to some of the forms from zone Io of the Calvert. C. coccymelus (Dall) is a rare species, and never abundant enough to be of stratigraphic value. The type was stated by Dall to have come from Plum Point, Maryland; hence it probably came from zone 10. The chief characteristic of this species is the single row of spines on each rib. The height of the shell is slightly greater in proportion to the length, and consequently the umbonal angle smaller than in typical C. madisonius. The holo- type may not be a full-grown adult. C. madisonius bassleri Tucker-Rowland is an unusually spinose POGOe) variety of C. madisonius, characterized by three rows of spines on each rib, the center row being more prominent than the other two. The presence of three scaly radials on each rib is quite character- 195 MaryLANpD MI0ocENE: SCHOONOVER 31 istic of C. madisonius and would not serve to differentiate this subspecies from C. madisonius. The degree to which the scales are developed into spines seems to be the distinguishing character. The umbonal angle is slightly greater than in C. coccymelus, and so the outline of the shell is close to that of C. madisonius from the Calvert. The holotype came from Plum Point, and the subspecies was also reported from Chesapeake Beach. The stratigraphic occur- rence is probably zone 10 in each case. A study of the specimens in my collections indicates that this subspecies simply represents one extreme in the many variations of the C. madisonius stock in the Calvert formation. It is not an outstanding, clear-cut subspecies, since it can only be separated by a minute comparison of many specimens with the original description and type material. It is too rare and too indistinct to be of stratigraphic value. The comparisons which Mrs. Tucker-Rowland made under the heading of “Remarks” in her original description of C. madi- sonius bassleri are unfortunate and confusing. This paragraph is quoted here: C. madisonius bassleri is smaller, and the shell is thinner than that of madisonius, s.s. The development of scaly sculpture is more pronounced ; ribs more numerous and narrower; left valves more convex; more nearly oval in outline. This subspecies tends to be larger than coccymelus, has fewer ribs; a single row of scales on the summits of the ribs; less conspicu- ous scaly sculpture; longer hinge line; more strongly convex. This sub- species appears to be quite characteristic of the Maryland Calvert. Mrs. Tucker-Rowland states in the paragraph quoted above that the ribs are more numerous in the subspecies than in madt- sonius, s. s. The subspecies carries 16 ribs. This is the same number Say gave in his original description for madisontus; it is the same number Mrs. Tucker-Rowland gives in her description of the “holotype” of madisonius (but which could not be the holo- type, as pointed out above). Mrs. Tucker-Rowland then gives the number of ribs as varying from 14 to 17 in her more general description of madisonius. Evidently the number of ribs could not be relied upon to separate the two. In comparison with C. coccymelus Mrs. Tucker-Rowland im- bo BULLETIN 94B 196 we) plies that a single row of spines on the ribs is a distinguishing character of the subspecies bassleri. The single row of spines on the ribs was the most conspicuous identifying characteristic of C. coccymelus, Mrs. Tucker-Rowland’s holotype of C. madi- sonius bassleri, in the National Museum, bears three rows of spines on each rib, the central one more prominent than the other two. An examination of the type specimens of both C. coccymelus and C. madisonius bassleri shows that it is C. madisonius bassleri which has the more conspicuous scaly structure, for in this sub- species the scaly radials cover not only the top of the ribs but also extend down their sides and across the interspaces. In the type of C. coccymelus there is only a single row of spines on the ribs, and the interspaces are smooth except for a single, extremely fine, beaded radial, and a second fine radial about 5 mm. from the ventral margin. It is not wise to rely too fully on the difference between one and three scaly radial striz, or rows of spines, on the major ribs. Often in young stages a single row appears first, and in more mature parts of the specimens an additional row appears on each side of the first. Hence, young specimens commonly show a single row of spines, and more mature ones three. There is also consid- erable variation in the degree of development of the second and third rows. Sometimes they are developed almost equally with the first row, and at other times they are much less well developed. Similarly there is considerable variation in the number and degree of development of the scaly radials in the interspaces. The general appearance of suites of specimens from different beds and localities varies, and it is possible to make some distinc- tions between such suites. These distinctions would not hold for individual specimens, but in large suites they are apparent. C. madisonius was reported by Shattuck from “zone 2” of the Calvert formation on a branch of Lyons Creek. It occurs in the oyster bed, zone 4, and from there up through the Choptank for- mation. It is noteworthy that in the lower beds of the Calvert formation the specimens are much smaller than those in the Chop- tank. The largest specimens this writer has collected from zones 4-10 of the Calvert scarcely exceed 80 mm. in height, and spec- imens of this size are not nearly so common as those about 60 mm. 197 Maryianp Miocene: ScHoonovieh 33 or less in height. In zone 14 of the Calvert specimens averaging 100-125 mm. in height first become common. In zone 17 of the Choptank formation, the specimens are of similar size to those in zone 14, but in zone 19 they are larger and heavier, the height commonly reaching 140 mm. In the oyster bed, zone 4, only small specimens less than 40 mm. in height are common. The scaly radial strize so common on specimens from other beds and localities are much less well developed. Along with these occurs C. madisonius, variety, which resembles C. marylandicus so strongly that it would at first be mistaken for that species. The only specimens of this variety collected here are so distinct from C. madisonius that they would never ‘be mistaken for that species, although similar forms in the Choptank show almost every gradation into C. madisonius. In the specimens from zone 4 the major ribs are only very slightly elevated. ach is covered by three radial threads, and there are about three radial threads in the interspaces. The general effect is that of a smooth surface covered by fine radial threads. In the beds between the oyster bed, zone 4, and zone Io, there are a few small specimens of C. madisonius scattered throughout, but they are not abundant. Those that are present are similar in character to those from zone 4. It seems possible that there is some relation between the development of these shells and the lithology of the containing beds. These beds, zones 4 through 9, are fine-grained, bluish, sandy clays, with some diatomaceous material. Zone 16 of the Choptank is similar in appearance, and in it the Pectens show a similar development—the specimens are small, relatively smooth, and with sharply elevated ribs. Prob- ably the environmental conditions which affected the type of sedi- ment also affected the life forms and resulted in similar develop- ments. My observations on the variations in the specimens found in these beds are not so dependable as those on specimens from zones 10, 14, 17 and 19, however, because the suites of specimens available for study are not nearly so large as in the latter cases. The following observations on the variations in the C. madi- sonius stock within zone 10 are based on a study of over three hundred specimens from various localities. The first and most 34 BuLLetiIn 94B 198 striking thing about the forms from zone to is their small size. The average specimen is less than 70 mm. high. On the other hand, if they are compared with young specimens of similar size from zones 17 and 19 of the Choptank, where the species attains a much greater size, they can usually, if not always, be separated. Perhaps the forms from the beds below zone 14 of the Calvert should be separated as a species or subspecies distinct from C. madisonius, s. s. of the Choptank on the basis of size and other differences. The Calvert forms from zone 10 certainly show consistent differences and are not identical with the typical large C. madisonius from zones 17 and 19 of the Choptank. There would be no mistaking large suites of specimens from the Calvert below zone 14 and those from the Choptank. Whether these dif- ferences are important enough to be given specific or subspecific rank is uncertain, and so they are merely described here without giving them new names. The chief variation observed in specimens of C. madisonius within zone 10 is that at the north end of the Calvert Cliffs a thin flat variety occurs which becomes much less common the further one goes away from the area just north of Randle Cliff Beach. This variety is illustrated on plate 4, figures 1-3. It possesses a thinner shell and is less convex than C. madisonius elsewhere in zone 10. The dorsal slopes from the umbo are very nearly straight lines, and not so concave as in C. madisonius from other localities, such as Plum Point. The height is greater in proportion to the length of the specimen in the variety. There are three scaly radial threads on each rib which are more uniform than in C. madisonius from zone 10 elsewhere. The scaliness begins quite early, usually within 10 mm. from the beak. In the interspaces there is one central, fine scaly thread, with one or more still finer ones on each side of it. About half of the specimens collected from locality 1, north of Randle Cliff Beach, belong to this variety. It is interesting to note that almost all the specimens of this variety are of a very light, yellowish-tan color, while those which are more like the forms which occur in zone 10 at Plum Point are also more like them in color, being darker and more grayish. Color certainly OF on 199 MarytANp MrocENE: SCHOONOVER could not be regarded as a reliable character for determining a variety of a fossil species, but it is rather striking that the color does coincide with other characters in this case. Some young specimens from the Choptank formation at Jones Wharf approximate this variety in shape, but lack the character- istic scaly sculpture, or else the scaliness does not start nearly so early. In specimens of C. madisonius from most beds and localities tie dorsal slopes from the umbones are straighter in young spec- imens, and become more concave in adults. They form nearly straight lines in many specimens from zone 10 near Randle Cliff Beach, but are more concave in specimens from Plum Point. In many large specimens from the Choptank these lines change their direction with growth so that in the last stages they begin to ap- preach parallelism with the hinge line itself. A suite of specimens from Plum Point compared with a suite cf specimens of similar size from Jones Wharf shows certain differences. In general, the ribs of the Plum Point specimens are more sharply elevated; the umbonal region is more convex ; the length is greater in proportion to the height than in specimens of similar size, but not in proportion to adult specimens ; the Plum Point specimens lack the fine, smooth radial lines common on Jones Wharf forms. Between Plum Point and Dares Beach there is a thin shell layer at the top of zone 10 which is slightly separated from the main mass of the zone itself. In specimens from this layer the scaly sculpture is rather well developed and much more uniform over the entire surface, ribs and interareas, than in specimens from other beds. Some of the very large specimens from zones 17 and 19 of the Choptank have scaly sculpture which is equally uniform, but coarser. A few specimens from zone 14 approach C. sayanus from the Oak Grove Miocene of Florida in the great length of the shell, and in the manner in which the ribs become flattened and almost obsolete toward the ventral margin. The sand in zone 14 car- ries a considerable admixture of mud, and the shells are not so well preserved as in the more purely sandy beds. Consequently the surface of specimens from this bed is usually weathered and 86 BuLLETIN 94B 200 the scales gone. On the specimens which do retain the scales, they seem to be fairly fine and evenly distributed, similar to those on specimens from the top of zone 10, referred to above. The number of ribs is quite variable in specimens from within the same bed and in specimens from different beds. There is a slight tendency toward a smaller average number of ribs in zone 19 of the Choptank. Specimens from zone Io at Plum Point have a range of 16 to 19 at least. About equal numbers of spec- imens have 17 and 18 ribs, and the next most abundant have 16. Specimens of the new variety from zone 10 north of Randle Cliff have a range of 17 to 19, 17 and 18 being most common. In zone 19 the common range is 13 to 18, with the majority of specimens bearing 14-16. Such differences could not be regarded as very dependable, and would be of no use in determining species. They are interesting, however, because they appear to continue the trend of reduction of the number of ribs found in the line from C. madisonius, through C. santamaria, to C. jeffersonius. Chlamys madisonius Figured specimens.—Nos. 3918, 3921, 3931-34, Paleontological Research Institution. Horizons.—Zones 4-19, Calvert and Choptank Miocene. Localities —Zones 4-9, localities 42, 40, 39, 52. Zone 10, lo- Callies 1, BO, 4h 5, 2s By 4A, BS, ©2, 1s, © Howe 14, localliines 53, 40, 45, 26. Zone 16, localities 23, 24. Zone 17, localities 47, 57, 34, 27, 25, 44, 7, 6, 59. Zone 18, locality 49. Zone 19, localities 2A, TS. BS, Si, BA, 12 Chlamys madisonius, variety approaching marylandicus. Figured specimens.—Nos. 3920, 3922-3924, and 3927, Paleon- tological Research Institution. Horizons.—Zones 4, 10, 14, Calvert; zone 17, Choptank Mio- cene. Localities.—40 ; 62; 45; 7, 59, 6. Undifferentiated Choptank, Bit, BB. Chlamys madisonius, variety. Figured specimens.—Nos. 3928-30, Paleontological Research Institution. Horizon.—Zone 10, Calvert Miocene. Localities.—1, 36, 5. co 1 201 MarvbLaNnp MIocENE: SCHOONOVER Chlamys coccymelus Horizon.—Zone 10, Calvert Miocene. Locality.—1. Amusium (Pseudamussium) cerinum (Conrad) Pecten cerinus Conrad, 1869, Am. Jour. Conch., vol. 5, p. 39, pl. 2, fig. 2. Pecten (Pseudamusium) cerinus Conrad. Dall, 1898, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 753; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 373, pl. 99, fig. 2. Amusium (Pseudamussium) cerinus (Conrad). Tucker-Rowland, Mus. roy. Hist. nat. Belgique, Mem., 2d ser., fase. 13, p. 68, pl. 5, fig. 11, pl. 6, fig. 8. Conrad’s original description.—Subovate, extremely thin, compressed; ears equal; right valve radiately ribbed; ribs very slightly raised and rounded; surface ornamented by minute, close divaricating lines, left valve without ribs. Dall, 1898—Shell small, thin, polished, compressed; left valve more convex, with about twenty faint, flat, rather irregular obsolete ribs, separat- ed by narrower, shallow sulci, the whole surface with minute Camptonectes striation; right valve with concentric incremental lines and a few faint threads near the beaks and anterior submargin; ears small, subequal; etenolium present; cardinal and auricular crura developed; interior of left valve faintly fluted, but without lire. Alt. 19, lat. 18 mm. In some of the specimens there are a few feeble concentric undulations near the beak of the left valve. This is always a very rare species. It is quite fragile, so that when it is found it is usually broken. I have collected seven spec- imens from locality 9 in Charles County, and one specimen from each of the other localities listed below. Horizons.—Zones 6?, 10, Calvert Miocene. Localities.—41 ; 35, 3, 48, 9. 1Q22 = 7) Order TELEODESMACEA Family ASTARTIDA Genus ASTARTE Sowerby The conditions for Astarte evolution during Miocene time must have been extremely favorable, and a profuse development of both species and individuals resulted. The common species show a great amount of variation so that in a collection with only the extremes represented they would be accepted without hesita- tion as full species. But in a large collection these very dissimilar shells are connected by a complete chain of intermediate forms, so that it seems best to regard the extremes as varieties of the main stock. 38 BULLETIN 94B 203 The table below gives all the species of Astartide here recog- nized as occurring in the Calvert and Choptank formations, and the zones in which each is known to occur: Zones Astarte cuneiformis 10, 14 Astarte cuneiformis var. parma 10 Astarte euneiformis var. calvertensis 10 Astarte cuneiformis var. obesa 10 Astarte thomesii 10 Astarte exaltata 10 Astarte thisphila 1@, ALY Astarte obruta, (l7@), IS, 1 In the Calvert Miocene the Astartes can be grouped rather readily into three main stocks: Astarte cuneiformis stock Hlongate, triangular outline Flattened beak; heavy umbonal ribs _... typical A. cuneiformis Flattened beak; heavy umbonal ribs; high in proportion, to aibSicsl CTO et a, ake te Ae AS eee A. cuneiformis var. parma Beaks not noticeably flattened; fine ribs extending varying distances over disk _____.....__. A. cuneiformis var. calvertensis Inflated form; smooth except for a few ribs on wumbo EO Oe oes nL POU AN TM EARL A. cuneiformis var. obesa Astarte thomasvi stock Quadrate, moderately inflated form; lunule impressed, concave. Fine-ribbed variety Broad-ribbed variety Astarte exaltata stock High, triangular; H equal to or greater than L; lunule deeply impressed, strongly concave. A. exaltata A. thomasu Astarte cuneiformis Conrad Plate 6, figs. 1-2, 5-6; Plate 7, figs. 5-6 Astarte cuneiformis Conrad, 1840, Fossils of the Medial Tertiary, p. 42, pl. 20, fig. 9; Dall, 1903, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1494; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 353, pl. 93, figs. 4-6. Conrad’s original description.._Shell trigonal, much compressed; umbo flat, with distant shallow undulations, and acute little prominent ridges; apex very acute; lunule very profound, with a sharply carinated margin; posterior side produced, cuneiform, acutely rounded at the extremity; cardinal teeth long and rather slender; margin crenulated. Glenn, 1904.—This shell is quite variable. The undulations near the beak may be either coarse or quite fine and may extend over a good portion of t.e surface, or they may be almost obsolete. The posterior side may be much produced and acutely rounded, giving the shell a distinctly cuneiform shape; or it may be only very slightly, if at all, produced, when the shell becomes more compact and triangular in outline. This shortening may continue until some specimens approach A. vicina in outline. The inner margin may be smooth. The base may be regularly arched or may be emarginate posteriorly. 203 MaryLAND MicceENE: SCHOONOVER 39 Astarte cunetformis and its varieties are the most common and characteristic representatives of the genus in the Calvert forma- tion. With one exception, | have found this group only in zone 10 of the Calvert. Five specimens of rather typical A. cuneiformis from zone 14 a short distance south of old Plum Point Whart constitute this exception. It would not be surprising if further collecting would yield additional specimens from the more fossil- iferous beds of the upper Calvert. In the sections given in the Maryland Miocene report Shattuck records A. cuneiformus from zone 2 on Lyon’s Creek (page Ixxxvi), but this has not been veri- fied, and I have not observed any Astartes below zone 10. The A. cuneiformis stock is abundant and extremely variable, and as a result several different species have been named corre- sponding to the extreme variations. Astarte parma Dall,’ (pl. 7, fig. 6) appears to be a high variety of A. cuneiformis. The umbonal sculpture “with about five small, fine ribs, close together, followed by three or four very distant, much wider ripples, obsolete towards the ends and ventral margin, with a few irregularly spaced linear concentric sulci beyond” (Dall) is not consistent, and is equally characteristic of A. cune?- formis. Astarte calvertensis Glenn® (pl. 6, figs. 5-6) represents the ex- treme variety in which the ribbing is all fine and evenly spaced, and extends over the entire disk. Series of specimens can be ob- tained ranging from those with the fine ribbing on the umbo only to those with it extending varying distances until it covers the entire disk. No sharp line can be drawn between the forms with the fine ribbing on the umbo only and those with it on the whole disk. Consequently it seems more appropriate to regard A. cal- vertensis as a variety of A. cuneiformis rather than as a distinct species. Aside from the character of fine ribbing these varieties differ from typical A. cuneiformis only in being slightly less elon- gate and less pointed posteriorly. Astarte cunetformis var. obesa Dall’ (pl. 6, fig. 1) is “thicker Dall We Hos Wagener Pree InstsiSei., Erans:, vol- 3, spt: 6; 119035 p. 1493, pl. 57, fig. 22. se or L. C.: Maryland Geol. Survey, Miocene, 1904, p. 352, pl. 94, 7 Dall, W. H.: Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, 1903, p. 1494. 40 BuLLETIN 94B di and more convex, with the umbones not flattened and the whole surface perfectly smooth.” It carries a very few ribs on the ex- treme tip of the umbo. This variety can be recognized quite readily. Specimens of 4. cuneiformis from the north end of the cliffs near Randle Cliff Beach average larger, smoother, more elongate, and more pointed posteriorly than those from farther south near Plum Point, and from the “Old Walls Place” in Charles County. The ribs do not usually extend so far over the disk, but are re- stricted to the umbones. They are usually few and coarse, not approaching the variety calvertensis, but tending more in the direc- tion of the variety obesa. The specimen illustrated on plate 7, figure 5 is representative of the forms from zone 10 near Randle Cliff Beach. Only one specimen from this locality showed fine ribbing approaching the variety calvertensis. One specimen might be called the variety parma. Some of the Randle Cliff specimens resemble A. perplana of the St. Mary’s, but the latter is higher in proportion to its length and more trigonal in shape. Also, the beaks are more nearly centrally located, and the ribs on the umbones are heavier and more smoothly rounded. Astarte cunetformis Figured specimens.—Nos. 3936 and 3946, Paleontological Re- search Institution. Horizon.—Zones 10, 14, Calvert Miocene. LOCOMIA, AO, 4, A, 5 By AS, O, 13, C2, 42, AS? 5, Astarte cunetformis var. obesa Figured specimen.—No. 3935, Paleontological Research Insti- tution. Horizon.—Zone 10, Calvert Miocene. Localities.—1, 36, 2, 48, 9. Astarte cuneiformis var. calvertensis Figured specimens.—Nos. 3939 and 3940, Paleontological Re- 205 MARYLAND MIOCENE: SCHOONOVER 41 search Institution. Horizon.—Zone 10, Calvert Miocene. Localities.—1, 2, 3, 48, 9. Astarte cuneiformis var. parma Figured specimen.—No. 3947, Paleontological Research Insti- tution. Horizon.—Zone 10, Calvert Miocene. Localities.—1, 2, 3, 48. Glenn® described a new species, Astarte castrana, from the Calvert as follows: Shell triangular, nearly equilateral, with rounded base; beak acts, turned slightly forward; shell flat or depressed; outer surface with small, shallow concentric grooves near the beak, slightly undulated over the rest of the shell by obscure and irregular growth lines, or in some specimens almost perfectly smooth over this outer part; teeth robust; ligament areas impressed; pallial line distinct; margin, smooth or crenulated. This species is doubtless the ancestor of Astarte thisphila from which it may be readily separated by its much smoother surface, much flatter form and thinner shell, as well as by its lacking the flattening or depression near the umbo so characteristic of thisphila. It has a less prominent beak, is flatter, less symmetrically rounded, thinner, and much less smooth on the surface than Astarte obruta. It is found only at a lower horizon than either of the other two species mentioned above. So far I have never seen any specimens from the Calvert forma- tion which I could identify, on the basis of this description, as Astarte castrana. Some young specimens of 4. thisphila from zone 17 of the Choptank answer most closely to the above descrip- tion, but there seems to be no adequate reason for trying to separate these from Astarte thisphila. Astarte thomasii Conrad Plate 7, figs. 1-4 Astarte Thomasti Conrad, 1855, Acad. Nat. Sci. Philadelphia Proe., vol. 7, p. 267; 1866, Am. Jour. Conch., vol. 2, p. 72, pl. 4, fig. 16. Astarte thomasii Conrad. Glenn, 1904, Maryland Geol. Survey, Miocene, p. 351, pl. 94, figs. 1-2. Conrad’s original description.—Triangular, not ventricose, inequilateral ; ribs concentric, robust, recurved; concentric lines more or less marked, minute; towards the posterior end the ribs suddenly become obsolete; ex- tremity truncated, nearly direct, or sloping inwards; inner margin crenu- lated; lunule large. ovate, acute, deeply excavated. Locality.—Near-Mullica Hill. Prof. Thomas. 8 Glenn, L. C.: Maryland Geol, Survey, Miocene, 1904, p. 353, pl. 93, P na ) J M ) ] i figs. 7-9. 42 BULLETIN 94B 200 Astarte thomasii represents a considerably less commion stock of Astartes than A. cunetformis. It is distinct and can readily be distinguished by its more quadrate outline, inflated form, and lack of flattening on the umbones. Two varieties can be recognized — one with fine, even, well-marked ribs similar to those on A. cunet- formis var. calvertensis, the other with broader, but less distinct ribs, which do not usually cover the entire disk. The basal part of the shell on the broad-ribbed variety is often smooth, and the entire shell does not reach the size attained by the fine-ribbed variety. This seems to be related to the lithology of the beds in which the species occurs, in that the fine-ribbed variety occurs in the more sandy beds, and the broad-ribbed variety in the more nuddy beds. The specimens figured in the Maryland Miocene report belong to the fine-ribbed variety. An examination of the specimens pre- served in the Maryland Geological Survey shows that the exterior view given in figure 1, plate 94, of that report does not portray the ribs clearly. The ribs are more numerous and more rounded than the figure would indicate. An examination of what are probably Conrad’s specimens in the Academy of Netiutrell Sciences in Phila- delphia indicates the same thing. There is some intergrading of these two varieties, though it is not so striking as in the case of A. cumeiformis, This may well be because the suites of specimens at hand for study are so much smaller in the case of A. thomasii, which is a much more rare species. Specimens of A. thomas with fine ribs are similar to A. calvertensis in that there is considerable variation in the area of the disk covered by the ribs. Conrad’s specimens from New Jersey, in the Academy of Natural Sciences in Philadelphia, have the ribs extending over the entire disk. The occurrence of A. thomasii is rather limited. So far I have found it only in zones ro at a few localities. It occurs south of old. Plum Point Wharf, and at locality 9 in Charles County. South of old Plum Point Wharf the fine-ribbed variety was found in the main mass of the shell bed. For some little distance at this same locality there is a thin shell band at the top of zone 10 which is separated slightly from the rest of the bed. A. thomasu is 207 MARYLAND MI0cENE: SCHOONOVER 43 common in this upper thin shell layer, in fact slightly more com- mon than A. cuneiformis. It is the broad-ribbed variety whica is present here. At the “Old Walls Place” in Charles County, locality 9, 4. thomasii is again rather common, and both the fine- and broad-ribbed varieties are present, though the former is more common. Figured specimens.—Nos. 3942-45, Paleontological Research Institution. Horizon.—Zone 10, Calvert Miocene. Localities.—3, 48, 9, 43, 38. Astarte exaltata Conrad Plate 7, figs. 7, 10 Astarte exaltata Conrad, 1841, Acad. Nat. Sci. Philadelphia Proe., vol. 1, p. 29; 1842, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 8, p. 185; 1845, Fossils of the Medial Tertiary, p. 66, pl. 37, fig. 6; Dall, 1903, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1489. Astarte vicina Say. Glenn, 1904, Maryland Geol. Survey, Miocene, p. 350, pl. 93, figs. 10-11. Conrad’s original description.—Obovate, acute, convex; umbo suleated; apex very prominent; lunule elongated and profound. Height and length equal, 5/8 inch. Dall, 1903.—A small, high species, with a very much impressed lunule and pointed, concentrically sculptured beaks, the concentric sculpture obso- lete towards the ventral margins. This species and A. vicina Say have frequently been confused. Both are rare, and Say’s figure of A. vicina was poor. Say gave the dimensions of his species as “length nine-tenths of an inch, breadth one inch,” but A. exaltata never reaches this size. The dimensions of any specimens of A. exaltata that I have seen are always less than 3/4 of an inch in either direction. A study of Conrad’s and Say’s material as preserved in the Academy of Natural Sciences in Philadelphia indicates that A. vicina and A. thomasii are more alike than A. vicina and A. exal- tata. Specimens, presumably Conrad’s, of A. vicina look like forms from the 4. arata group from Virginia, and I do not feel certain that these specimens even came from Maryland. They look more like specimens from the Yorktown of Virginia. A. exaltata-is usually rare, but at one locality, No. 9, in Charles County, it is common, and slightly more abundant than 4. cunet- formis. It occurs only in zone 10. 4.4. BULLETIN 94B 208 Figured specimen.—No. 3948, Paleontological Research Insti- tution. Horizgon.—Zone 10, Calvert Miocene. Localities.—2, 3, 48, 9, 43. In the Choptank formation there are two species of Astarte, A, thisphila and A. obruta. They can usually be separated easily from the Calvert forms and from each other by the characters indicated in the following table: Short, high, triangular, inflated Umbones flattened, heavily ribbed A. thisphila zones 16, 17 tk ea See ee A. obruta zones 18. 19 A. thisphila is conspicuously flattened in the umbonal region, and bears heavy, angular, concentric ribs, which usually extend 10-5 mm. over the disk. In A. obruta the tip of the beak for a distance of not over 5 mm. is flattened and bears a few concentric ribs, bit the rest of the shell is moderately inflated and smooth. A. obvvta is much like an isosceles triangle in outline; 4. thisphila is ss perfectly so. Umbones not flattened; surface smooth <1. thisphila is much more variable than A, obruta. Some var- ieties resemble 4. obruta in outline, but can be separated by the heavy ribs and flattening near the beak. A few specimens show such distinct gradations into typical A. obruta that the two cannot be separated. Others resemble some varieties of 4A. undulata cf the Yorktown, and may have been ancestral to that form, though they are distinct and should not be included with it. Glenn states that A. thisphila is usually less convex than A. undulata, but this does not hold true for the specimens at hand. The two seem to be about equally convex, though the former is a smaller species. At many localities the smaller forms of 4. thisphila are shorter, higher, more inflated, and more conspicuously flattened in the um- bonal region than the typical forms. These are so striking that they might almost be given a varietal name, but all gradations into the more typical form are present. This variety is particularly coramon in zone 17 along the Patuxent River, north and south of 209 MaryuaNnp MIocENE: SCHOONOVER 45 Jones Wharf, and on the Bay shore at localities 27 and 25, north and south of Calvert Beach. This variety is more distinct from A. obruta than is the typical A. thisphila, and at first, from a com- parison of forms from Jones Wharf with the published description, I took the variety to be the typical form. An examination of the types in the Maryland Geological Survey showed that the species was described from the larger, longer and less inflated forms. A. thisphila occurs in both zones 16 and 17, but it is much more abundant and characteristic in the latter. A. obruta occurs in zones 18 and 10, and is more abundant and characteristic in zone 1g. It is the only Astarte occurring in zone 19. I have never seen a specimen of A. thisphila in zone 19, and the Astartes in that zone seem to be quite constant and easily identifiable. In the sec- tions given in the report of the Maryland Geol. Survey A. this- phila is reported from zone 19 south of Parker Creek (page Ixxxix), and at Flag Pond (page xci), although in the descrip- tion of the species it is reported to occur only in the lower fossil bed, or zone 17 (pp. 355-350). The reference of this species to zone Ig was probably a mistake. Certainly if A. thisphila ever occurs in zone 19 it is not common enough to be considered char- acteristic. Glenn reported A. thisphila from the Calvert formation at Plum Point, but I have never seen it outside of the lower portion of the Choptank formation. Jf it does occur in the Calvert, it 1s very ae: On the other hand rare specimens of A. obruta were collected by the author from zone 17, but these were so few that they do not invalidate the statement that-d. obruta is characteristic only of zone 19. At one locality north of Scientists’ Cliffs, 4. obruta was found commonly in the clays between zones 17 and 19, that is, in zone 18. The source of 4. thisphila is not clear, and it seems to be more closely related to A. distans from the New Jersey Kirkwood formation and to 4. floridana from the Florida Choctawhatchee than to any of the forms in the Calvert Miocene of Maryland. 46 BULLETIN 94B 210 Astarte thisphila Glenn Plate 8, figs. 1, 4 - Astarte thisphila Glenn, 1904, Maryland Geol. Survey, Miocene, p. 355, pl. 94, figs. 7-9. Glenn’s original descrip/ion.—Shell triangular; moderately thick, convex, but depressed or flattened near the beak; angular undulations on the beak prominent, becoming broader farther from the beak and extending well toward, or in some cases entirely to, the basal margin; tip of beak curved forward, producing a convex curve or shoulder on the dorsal margin just posterior to the apex; anterior margin regularly rounded; basal margin rounded anteriorly, straight or slightly emarginate posteriorly; posterior extremity above the line of the base and obtusely rounded; interior smooth except in quite young specimens, when it is some‘imes slightly undulated ; teeth strong... It differs from the A. obruta by having a less symmetrically curved sur- face and outline, by being strongly undulated and by the characteristic convex curve or shoulder just posterior to the tip of the beak... Figured specimens.—Nos. 3950 and 3952, Paleontological Re- search Institution. Horizon.—Zone 16, 17, Choptank Miocene. Localities.— 23 ; 57, 27, 25, 44, 56, 34, 7, 6, 59. Astarte obruta Conrad Plate 8, fig. 5 Astarte obruta Conrad, 1834, Acad. Nat. Sci. Philadelphia, Jour., Ist ser., vol. 7, p. 150; 1840, Fossils of the Medial Tertiary, p. 43, pl. 21, fig. 2; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 354, pl. 94, figs. 9-6. Conrad’s original description.—Shell triangular, convex, smooth, with a few obsolete undulations; beaks prominent, suleated, margin crenulated ... Allied to A. undulata Say, but is more convex and not profoundly undu- lated; the umbo is not flattened. Glenn, 1904.—Shell nearly equilateral, moderately thick; the suleations on the beak usually not prominent and extending but a very short distane> from the tip of the beak; the rest of the gently convex surface smooth except for a few broad, almost obsolete, undulations; surface occasionally crossed from beak to base by exceedingly faint, slightly impressed, radial lines; beak projecting, acute, with its very tip curved somewhat forward. The gently rounded outline, and moderately convex, almost smooth sur- face serve to distinguish this species from any other... Figured specimen.—No. 3953, Paleontological Research Insti- tution. Horizons.—Zone 17 (rare) ; zones 18, 19, Choptank Miocene. Localities.—6, 59; 49; 33, 15,55, 51- Family CRASSATELLIDA Genus EUCRASSATELLA Iredale Three species of Ewcrassatella are present in the Calvert and Choptank formations of the Maryland Miocene. ‘They are closely 211 MaryniaNnp MioceENE: SCHOONOVER 47 related species, but they are sufficiently distinct in characteristics and distribution to serve as horizon markers. EF. melina is char- acteristic of zone 10 of the Calvert, but also occurs in zone 14. E. turgidula occurs sparsely in zone 16 of the Choptank, abundant- ly in zone 17, and in zone 18 at one locality. E. marylandica 1s common and characteristic in zone 19 of the Choptank, and occurs only in zone 19 so far as 1am aware. One specimen of Eucrassa- tella was reported by Mansfield from the St. Mary’s formation of the St. Mary’s River, and I collected one specimen from the St. Mary’s at Langley’s Bluff. A few of the distinguishing characteristics of the three species are summarized in the following table: Beaks conspicuously flattened. Umbonal ribs extend less than 8 mm. from beak; GY] GYONDT Pell LX Ovesrtvayy SraY Waa gu] Osean cw 0 UN eel cae Na ee eee E. melina zones 10, 14 Umbonal ribs extend 10-15 mm. from beak; about 10 in number E. turgidula zones 16-18 Beaks rounded, incurved Umbonal ribs extend 5 mm. or less from beak; 4) tin impmaler, low, wemeuliiy COCO) oon eecnecseeceseccersce= sno EL. marylandica zone 19 The original descriptions and some later characterizations of the species are quoted below for reference. For the purpose of the present discussion it seems best to consider all the species together and to treat them as a group, rather than under the head- ings of the individual species. There appear to be no consistent differences in suites of speci- mens from different localities, as was the case with some other forms, such as the Pectens. The chief distinctions which can he made among the three species relate to the following characters — shape, thickness, and convexity of the shell; flattening of the umbo; umbonal ribs. E. marylandica can usually be separated from the other two species by its rounded beak. The umbones of E. melina and E. turgidula are conspicuously flattened and bear heavy illo. Ilsa E. marylandica there is only a very slightly flattening which does not extend for more than 5 mm. and which is commonly obscured by erosion of the beaks. The beaks are smooth except for a few 48 BULLETIN 94B 212 fine concentric ribs which are present only in well-preserved speci- mens. The umbonal ribs in E. melina are of the same general charac- ter as in FE. turgi ula. The earliest ones are fine, the later ones coarser. In E. turgidula they extend slightly further over the disk and become coarser than in FE. melina. In both species they die out anteriorly, and are absent posterior to the umbonal ridge. They are heaviest just anterior to the umbonal ridge. E. melina is thinner-shelled and more evenly convex over the entire surface than the other two species. FE. turgidula and E. marylandica are heavier, more strongly convex, and more pointed posteriorly than FE. melina. The average specimen of EF. melina is more square posteriorly. The shell substance is thicker in both E. turgidula and E. marylandica than in E. melina. Specimens of E. turgidula which are not full grown are less thickened. The outline of E. marylandica is much like that of FE. turgidula, but the posterior dorsal margin is more concave, and consequently the posterior part of the shell appears to be longer, narrower, and more pointed. EF. turgidula, in turn, is narrower and more pointed posteriorly than E. melina. The posterior dorsal margin is slightly concave, but less so than in EF. marylandica, and more so than in E. melina. In young specimens the posterior dorsal margin is straight or slightly convex, and the outline of the shell is more like that of E. melina. Young specimens of the two species are somewhat difficult to differentiate, but in EF. turgidula the umbonal ribs are heavier and extend a little further over the disk. Of the three species, E. melina is the most compressed. FE. tur- gidula and EF. marylandica are about equally convex, but both are more convex than FE. melina. FE. marylandica appears more con- vex because the beak is more rounded and more strongly incurved. In E. turgidula the greatest convexity is sometimes centered at a point just posterior to the center of the shell, giving the entire shell a slightly twisted aspect. é The truncated, posterior, dorsal slope is most flattened in FE. melina. In both FE. turgidula and E. marylandica it is narrower lig MARYLAND Miocene: ScHOONOVER 49 and more rounded, and bears a secondary ridge proceeding from the border of the escutcheon to the posterior dorsal angle. It is separated from the principal surface of the shell by a sharper angle than in the case of FE. melina. In Glenn’s description of E, melina he noted that the species 1s “Somewhat more produced posteriorly and hence is proportionally narrower along tie obliquely truncated posterior margin than 1s represented in Conrad’s figure.” This is true for some of the specimens from zone ro in Maryland, but there is also consider- able variation in the degree of elongation of the posterior part of the shell, and Conrad’s figure is typical of some of the shorter forms. Undoubtedly these forms all belong to the same species. for the range of variation is not great enough to enable one to pick out the extremes as separate species even if the intermediate forms were absent . Glenn’s statement (see quotation below) that adult specimens of E. turgicula and E. marylandica are difficult to separate seems less true of the suites of specimens which the present writer has collected than the fact that E. melina and E. turgidula are difficult to separate. This difference of opinion might be taken as an indi- cation of the close relationship of all three species. Specimens from zone 14 of the Calvert formation are somewhat difficult to determine, because the preservation of all shells from this bed is poor. They are identified as E. melina in this report, although if more perfect specimens were available it is possible that they would be intermediate between E. melina and E. turgidula. Forms from zone 18 at locality 49, north of Scientists’ Cliffs, are intermediate between EF. turgidula and E. marylandica, All the specimens obtained were somewhat broken, but they resemble E. marylandica except for the beaks, which are flattened and ribbed as in E. turgidula. Eucrassatella melina (Conrad) Plate 6, figs. 3-4 Crassatella melina Conrad, 1832, Fossil Shells of the Tertiary Formations of North America, p. 23, pl. 9, fig. 2; 1838, Fossils of the Medial Ter- tiary, p. 22, pl. 12, fig. 2. Crassatellites melinus (Conrad). Glenn, 1904, Maryland Geol. Survey, Miocene, p. 346, pl. 92, figs. 1-2. Conrad’s original description.—Ovate, thick, not compressed; anterior 50 BULLETIN 94B 914 margin obtusely rounded; posterior margin oblique and angular; dorsal margin nearly straight; concentric lines coarse; umbonial slope subangular and scareely curved; beaks with concentric grooves; inner margin entie. Locality. Cumberland Co., N. J. Upper Tertiary. This shell is intermediate to C. undulata anu Marylandca, but is per- fectly distinet from both ..: . Glenn, 1904.—This species, as found in Maryland, is more properly de- seribed as subovate, convex-depressed, and rater tin except in old speci- mens, which are somewhat thicker and more convex. It is somewhat more produced posteriorly and hence is proportionally narrower along the oblique truncated posterior margin than is representei in Courad’s figure. The dorsal slope has regular, well marked, angular, concent-ie undulations near the beak that become obsolete during later stages of growth; posterior and dorsal slopes separated by a distinctly angular line; posterior slope some- what flattened; posterior dorsal margin but sligi.tly concave; hinge area rather narrow, not massive; muscular impress.ons and pallial margin very distinet. Figured specimens.—Nos. 3937 and 3938, Paleontological Re- search Institution. Horizons.—Zones 10, 14, Calvert Miocene. Localities.—1, 36, 4, 2, 5, 3, 48, 9, 38; 45. Eucrassatella turgidula (Conrad) Plate 6, fig. 7; Plate 7, figs. 8-9 Crassatella turgidula Conrad, 1843, Acad. Nat. Sci. Pailadelphia Proe., vol. 1, p. 807; 1845, Fossils of the Medial Tertiary, p. 69, pl. 39, fig. 7. Crassatellites turgidulus (Conrad). Glenn, 1904, Maryland, Geol. Survey, Miocene, p. 348, pl. 92, figs. 3-5. Conrad’s original description.—Oblong-ovate, slightly ventricose; surface with coarse lines of growth, and concentric undulations obsolete except on the umbones, where they are strongly marked and wide; beaks submedial; umbones flattened; anterior dorsal margin straight; posterior extremity truncated and nearly direct, more oblique in young shells; basal margin swelling a little anteriorly, posteriorly straight to the extremity which is obliquely angulated. Locality. Calvert Co., Md. Allied to C. Marylandica, but has less prominent, more flattened um- bones, which are widely and profoundly undulated. It is, also, more ven- tricose, and has a more regularly arched basal margin. Young shells of the two species are widely unlike each other. Glenn, 1904.— Shell thick, convex, and not strongly produced posteriorly ; umbo not prominently elevated; posterior dorsal margin slightly concave or nearly straight; hinge area broad; teeth robust; muscular impressions deep; pallial line distinct. The young are long-ovate in outline, thin and flat; surface with very prominent, regular, angular, concentric undulations on the umbonal slope and extending over a large portion of the entire surface of the shell; pos- terior dorsal margin straight or convex. This species is likely to be confused with C. marylandicus, but may be separated in the adult stage by having a less prominent, broader, and more 215 MaryLANp M1ocENE: ScHOONOVER 51 flattened umbo and a more profoundly and widely undulated umbonal slope, by being less produced posteriorly and by having a muci less concave pu- terior dorsal margin. ‘1he young or the two species are quite distinet and need never be coniused with each other. Figured specimens.—Nos. 3941 and 3949, Paleontological Ke- search Institution. Horizons.—Zones 16-18, Choptank Miocene. Localities. —23, 24; 7, ©, 10, 21, 59, 27, 25, 44, 57, 50; 49. Eucrassatella marylendica (Conrad) Plate 8, figs. 2-3, 6 Crassatella Marylandica Conrad, 1832, Fossil Shells of the Tertiary Formations of North America, p. 22, pl. 8, fig. 1; 1838, Fossils of tae Medial Tertiary, p. 21, pl. 12, fig. 1. Crassatellites marylandicus (Conrad). Glenn, 1904, Maryland Geol. Survey, Miocene, p. 347, pl. 93, figs. 1-3. Conrad’s original description.—Ovate oblong, thick and ponderous; pos- terior side narrowed and produced, with the extremity slightly angular or obtusely rounded; umbonial slope subangular; inner margin entire. Locality. | Choptank river, near Haston, Md. Upper ‘Ler. Glenn, 1904—Shell convex; umbo elevated and prominent; regular con- centric undulations on umbonal slope very slightly developed or obsolescent ; surface marked by somewnaat irregular growth lines; posterior basal margin often slightly emarginate; pos.erior and dorsal slopes meet in an angular line or ridge; posterior slope crossed by a slightly obtuse ridge extending from the beak io the upper end of the obliquely truncated posterior margin ; posterior dorsal margin deeply concave, anterior ome straight; hinge area broad; teeth robust; museular impressions deep; pallial line distinct. The young are convex, thick and massive also, with prominent beaks and put slightly produced posterior extremity, giving the shells a triangular outline. The regular, concentric undulations on the umbonal slope are small and not profound and are confined to the portion of the surface in the immediate vicinity of the umbo. This species is likely to be confused in the adult stage with C. turgidulus, with which it is doubtless closely related. Figured specimens.—Nos. 3951 and 3954, Paleontological Re- search Institution. Horizon.—Zone 19, Choptank Miocene. Localities.—33, 55, 15, 51. Family LUCINIDA Genus SAXOLUCINA Stewart Subgenus MEGAXINUS Brugnone, 1880 (emend.) Two species of Saxolucina are present in the Maryland Mio- cene, S. foremani and S. anodonta. S. anodonta appears first in zone 10 of the Calvert formation, and continues throughout the Calvert, Choptank, and St. Mary’s. It also occurs in the York- ov to: BULLETIN 94B 216 town Miocene of Virginia, and in the Pliocene of South Carolina and blorida. S. foremani occurs chiefly in zone 10 of the Calvert. Glenn reported it from the Choptank formation at Governor Run, but I have not found it except in zone 10. Certain facts concerning the distribution of these two species within the Calvert formation are of interest. S. anodonta is much more abundant at the north end of the cliffs (near Randle Cliff Leach) than at any other locality in zone 10, and S. foremani is iather rare here. Further south S. anodonta gradually becomes less abundant, and S. foremani more abundant. However, even where S. foremani is most abundant, it is never so abundant as S. anoconta at the localities where the latter is most common. For example, north of Randle Cliff Beach I collected more than 80 specimens of S. anoconta, to three of S. foreman. At Plum Point (locality 3) I collected 19 specimens of S. anodonta to 40 of S. foremani, The first locality south of Randle Cliffs where S. foremani is common is number 5, south of Camp Roosevelt. 5S. foreman 1s more common than S. anodonta at the “Old Walis Place,” locality 9. A few variations in the form of S. anodonta can be noticed in suites of specimens from different beds and different localities. Specimens from the Choptank are on the average larger than those from either the Calvert or the St. Mary’s. They are also slightly flatter in proportion to their size than those from the Calvert. Specimens from zone 17, especially from Jones Wharf, seem to have the growth lines and surface more even and regular than on those from the Calvert formation. Specimens from any beds may be considerably thickened by the addition of material to the inside of the shell, chiefly in the area enclosed by the pallial line, but this tendency is especially noticeable in specimens from zone 19 of the Choptank. Some forms from zone 19 north of Camp Conoy are thickened in this way until they are almost half an inch thick. This is probably a pathological character. The inside of the shell, principally the area enclosed by the pallial line, is commonly very rotten and tends to break away from the rest of the specimen. The muscle scars show a similar tendency. Often they are represented by holes where the shell substance has broken out. Or ws 217 MaryLaAnp MIo0cENE: SCHOONOVER Specimens from the St. Mary’s formation are somewhat inter- mediate between S. anodonta and S. foremant. They are smaller than S. anodonta from the Choptank, slightly smaller than 5S. anodonta from the Calvert, but larger than S. foremam. ‘They are more convex than S. anodonta, less so than S. foreman. They are less perfectly orbicular and have more clearly developed angles where the dorsal and posterior, posterior and ventral margins meet than in S. anodonta from the Calvert and Choptank. Mansfield? mentioned that “The shell of this species (S. ano- donta) from the Calvert and Choptank formations is larger and thinner than that in the succeeding St. Mary’s formation.” It is true that they are larger, but they are not consistently thinner. The St. Mary’s specimens in my collections are more consistent in thickness than those from the Calvert and Choptank, and many from the latter are thicker than any St. Mary’s forms. Saxolucina (Megaxinus) foremani (Conrad) Plate 11, fig. 5 Lucina Foremani Conrad, 1841, Acad. Nat. Sci. Philadelphia Proe., vol. 1, p. 29; 1842, Acad. Nat. Sci. Philadelphia Jour., Ist ser., vol. 8, p. 184; 1845, Fossils of the Medial Tertiary, p. 71, pl. 40, fig. 4. Phacoides (Pseudomiltha) foremant (Conrad). Glenn, 1904, Maryland Geol. Survey, Miocene, p. 336, pl. 90, figs. 1-2. Saxoluctna (Megaxinus) foreman Say. Chavan, 1938, Jour. conchy- liologie, vol. 82, p. 79. ‘ Conrad’s original description.—Orbicular, ventricose, moderately thick; surface with irregular shallow grooves, and rather distant prominent striz, with intermediate, fine, concentric lines; posterior margin subtruncated obliquely outwards; beaks prominent, not central; hinge edentulous. Length 1 1/2 inch. Glenn, 1904.—It may be distinguished from P. anodonta by being smaller and much more convex; as found in Maryland, the interior, prismatic por- tion, of the shell is often badly decayed, while the exterior portion is usual- ly well preserved; it is at times quite thick. Figured specimen.—No. 3966, Paleontological Research Insti- tution. Horizgon.—Zone 10, Calvert. Localities.—1, 4, 2, 3, 48, 9. Saxolucina (Megaxinus) anodonta (Say) Plate 10, fig. 5 Lucina anodonta Say, 1824, Acad. Nat. Sci. Philadelphia Jour., vol. 4, p- 146, pl. 10, fig. 9; Conrad, 1840, Fossils of the Medial Tertiary, p. 39, pl. 20, fig. 4. 9 Mansfield, W. C.: Miocene pelecypods of the Choctawhatchee forma- tion of Florida, Florida Geol. Survey Bull. 8, 1932, p. 99. 54 BULLETIN 94B 218 Phacoides (Pseudomiltha) anodonta (Say). Dall, 1903, Wagner Fiee Inst. Sci. Trans., vol. 3, pt. 6, p. 1378; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 337, pl. 90, figs. 3-4; Mansfield, 1932, Florida Geol. Survey Bull. 8, p. 98, pl. 20, fig. 19. Saxolucina (Megaainus) anodonta Say. Chavan, 1938, Jour. conehyliolo- gie, vol. 82, p. 79. Say’s original description.—Orbicular, slightly transverse, compressed; teeth obsolete. Shell with elevated wrinkles; orbicular, a little transverse, with a very slight impressed longitudinal line on the anterior margin: anterior and posterior ends equally curved: apices not prominent beyond the general curve of the shell, with a very short deep emargination behind them; teeth obsolete; both the cardinal and lateral ones are generally altogether want- ing: lunule short, cordate, profound. Length from the apices to the base one inch and one-tenth, breadth one inen and one-fifth. The impressed line on the anterior part of the shell is hardly visible in many specimens, and is sometimes only a very slight undulation, not obsery- able but on close inspection ... Figured specimen.—No. 3960, Paleontological Research Insti- tution. Horizons.—Zone 10, Calvert, zones 17, 19, Choptank, LOCOMIA, XO, Ah GS, By As}, O)3 (Gy WO, Ail, SO), 7, AL, D7, Be, a7 337 90% 25: Genus LUCINOMA Dall Lucinoma contractus (Say) Plate 11, fig. 9 Lucina contracta Say, 1824, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 145, pl. 10, fig. 8; Conrad, 1840, Fossils of the Medial Ter- tiary, p. 40, pl. 20, fig. 5. Phacoides (Lucinoma) contractus (Say). Glenn, 1904, Maryland Geol. Survey, Miocene, p. 339, pl. 90, figs. 5-6; Mansfield, 1932, Florida Geol. Survey Bull. 8, p. 99, pl. 20, fig. 23. Say’s original description.mShell convex, suborbicular, with numerous concentric, regular, equidistant, elevated, membranaceous strie, and inter- mediate smaller transverse lines: umbones not very prominent: apices proxi- mate, nearly central: anterior hinge margin rectilinear, to an ob.use ang!e near the middle of the anterior margin: anterior submargin with a very slightly impressed line: posterior margin rounded: cardinal teeth one in the left valve, and two in the right, the posterior one of which is subbifid at tip: lateral teeth none: within obsoletely striated towards the margin: posterior muscular impression perfectly rectilinear, elongated, and oblique. Length one inch and nine-tenths, breadth two inches and one-tenth. This species was reported by Shattuck as common and char- acteristic of zones 1-3 of the lower Calvert. The lowest strati- graphic horizon at which I have found it is zone 14 of the upper Calvert. It is very common in zone 16 of the Choptank just 219 MaryuAND MI0cENE: SCHOONOVER 5d north and south of Calvert Beach and in fact is the most common single species here. It occurs in its living position with the plane between the valves vertical. It is the most conspicuous example in all the Maryland Miocene of a fossil being preserved in its living position. Locality 27, north of Calvert Beach is the only locality where this form is abundant in zone 17. It was found in zone 17 at two other localities, number 44 just north of Long Beach, and number 6 south of Jones Wharf, but only a few specimens were collected at each place. One double-valved specimen was found in the St. Mary’s formation at Little Cove Point. For the most part it seems to be true that this species is most common in beds other than the main shell layers. In beds where the other fossils are most abundant this one is absent or present only in very small numbers. The only exception to this is locality 27, north of Jones Wharf. It is noteworthy that this is the same locality at which the species is most abundant in zone 16. Specimens of L. contractus from the Florida Miocene are larg- er and more nearly circular than the Maryland specimens. Figured specimen.—No. 3970, Paleontological Research Insti- tution. Horizons.—Zone 14, Calvert; zones 16, 17, Choptank. Localities. —26, 45; 23, 24; 27, 44, 6. Family ISOCARDIIDZ Genus ISOCARDIA Lamarck Four, and possibly five, species of /socardia are present in the Calvert and Choptank formations of Maryland. Some of their characters, and their distribution are indicated in the following table: Length greater than height Shell large, inilated, with a pronounced umbonal ridge. Moderately rounded, ovate _.. I. fraterna var. marylandica, n. var. Zones 14-17 More elongate and pointed posteriorly _............2......--- I. ignolea Zone 14 Shell small, not greatly inflated; umbonal ridge not prominent Isocardia sp. ‘“Zone 5’? 56 BULLETIN 94B 29) Length approximately equal to height Much inflated, high Beak profoundly incurved I. markoci Zone 10 I. mazlea Zone 10 Beak less strongly incurved All of the Maryland species of /socardia show considerable variation in form. J. fraterna var. marylandica, n. var. is the most common and the most variable of the Maryland forms. This variety has usually been considered identical with /. fraterna, but that name should be restricted to the larger, more circular forms from the Yorktown Miocene of Virginia. A comparison of the Virginia and Maryland forms shows consistent differences which warrant varietal, 1f not specific, rank, At the north end of the cliffs along the Bay Shore of Mary- land, between Chesapeake Beach and Captain Hubbard’s place, there is a thin band of /socardia within zone 5, a short distance above the oyster bed. The Isocardias in this bed are small, aver- aging about 144 inches in length, elongate, and usually somewhat crushed. It is rather difficult to obtain perfect specimens from this bed, but those collected are not identical with the forms from the higher beds. Specimens from zone 5 are less pointed poster- iorly, the umbonal ridge is less marked and acute, and the dorsal margin parallels the ventral for greater distance than in the Chop- tank forms. How much of this difference may be due to the dif- ferent environment in which the forms lived is impossible to say. It accompanies a marked difference in lithology, and it does not seem improbable that the differences might be explained by dif- ferences in ecology. Isocardia ignolea is related to /. fraterna var. marylandica but is more elongate and pointed posteriorly. It is very similar in shape to young specimens of J/. fraterna marylandica from zone 17 of the Choptank north of Calvert Beach. The locality and horizon from which the type specimens of /. ignolea came is un- known. Glenn gave it as either Plum Point or Little Cove Point, which would mean either the Calvert or St. Mary’s formations. Unfortunately the species is rare, and I have not found enough additional specimens to give much information on its distribu- 221 MARYLAND Mi0cENE: SCHOONOVER 57 tion. The only specimens in my collection which I could assign to this species are two from zone 14 of the Calvert, at locality 45, south of the mouth of Parker Creek. Two species which differ more markedly from those mentioned above are J. markoéi and J. mazlea. They are rare species, and both are limited to zone 10 of the Calvert formation. They can be separated rather readily from J. fraterna marylandica and the forms of that group by the fact that they are very short and high, the height and length being about equal. They can be separated from each other by the fact that the beak of J. markoéi is consider- ably more incurved than that of J. mazlea. Conrad originally described J. markoéi but included figures of both species. His description applies partly to one and partly to the other. Glenn noted that Conrad had included two species, and restricted the name J. markoéi to the one with the more strongly incurved beak, and described the other as J. mazglea. Isocardia fraterna var. marylandica, n. var. Plate 9, figs. 4-6; Plate 10, ae | figs. 4, 6 Isocardia fraterna Say. Dall, 1900, Wagner Free Inst. Sci., vol. 3, pt. 5, p. 1066 (im part); Glenn, 1904, Maryland Geol. Survey, Miocene, p- 317, pl. 85, figs. 3-4. Description.—Shell moderately large, inflated, ovate; moderately elongat- ed; often thin-shelled for its size; surface smooth except for growth lines and irregular concentric undulations 5 to 15 mm. wide, probably represent- ing alternate growth and resting stages, and which are sometimes reflected on the inner surface of the shell. Beaks aniterior, ineurved; umbonal ridge prominent, and making a distinct angle at the posterior ventral margin. Sometimes there is a shallow depressed area just anterior to this ridge; a second, less prominent ridge is often present along the middle of the slope posterior to the umbonal ridge. This variety differs from typical J. fraterna from the higher Miocene beds of Virginia and North Carolina in being smaller and less circular in outline; the umbones are wider and higher; there is often a depressed band extending from the beaks to the posterior-ventral margin, and the posterior end is bluntly pointed. The Virginia forms differ from the variety in their larger size, more rotund and circular outline, lack of the depressed band just in front of the umbonal ridge, and heavier hinge. Say figured and described as /. fraterna one of these larger, more circular 58 BULLETIN 94B 222 shells. Hence the designation of /. fraterna, s. s. must be re- stricted to the Virginia shells closest to Say’s figure and descrip- tion. Considerable variation is shown by the Maryland forms. As noted by Dall, young specimens tend to be more elongate than adults. Some resemble /. ignolea, particularly in suites of speci- mens from zone 17 of the Choptank north of Calvert Beach. Maryland specimens commonly have a pronounced ridge separat- ing the dorsal and posterior slopes. This ridge makes an angle at the margin. The angle is usually more pronounced than is indicated by figure 4, plate 85, of the Maryland Geol. Survey report. Some specimens are much more rounded in outline and inflated, resembling Conrad’s drawing (1838) of the Virginia form, while others are flatter and more elongate. Three speci- mens from zone 16 of the Choptank, north of Calvert Beach, re- semble Virginia forms, and are more rounded, inflated, and the umbonal ridge is inconspicuous. Another variation is represented by more quadrate forms in which the posterior is more square than pointed. Some speci- mens from zone 14, north of Governor Run are of this type. The onlv three specimens of Jsocardia which T have collected from the St. Marvy’s formation (from St. Mary’s River) and a fourth one in the U. S. National Museum from the same localitv belons to this variation. These St. Mary’s specimens are slight- lv thinner-shelled than typical forms from other horizons and lo- calities. Thev possess concentric undulations 10-1& mm. broad, which are reflected on the inner surface of the shell. Finer con- centric growth lines are superimposed on these broad undula- tions. Broad undulations of this tvpe are not uncommon on spec- imens from other localities, but they are more pronounced. more regular, and more strongly reflected on the inner shell surface of these St. Mary’s specimens. Tsocardias are on the whole quite rare in the St. Mary’s. The four specimens noted above are the only ones T have ever seen in that formation, 993 MaryLANp MiocENE: SCHOONOVER 59 At the present time I cannot state definitely whether /. fraterna marylandica occurs in zone 10 of the Calvert. My suites of spec- imens from zone 10 are small and consist chiefly of J. markoei and J. mazlea. A few specimens may represent especially short forms of I. fraterna marylandica, but in the absence of a larger series of specimens I cannot separate them positively from J. maglea. - Types.—Holotype, No. 3956; paratypes, No. 3959, 3961 ; fig- ured specimen 3957, Paleontological Research Institution. Horizons.—Zone 14, Calvert Miocene; zones 16, 17, Chop- tank Miocene. Localities. —54, 53, 45, 263 23, 24; 27, 25, 44, 34, 47, 57; 7) © 59. Isocardia ignolea Glenn Isocardia ignolea Glenn, 1904, Maryland Geol. Survey, Miocene, p. 318, pl. 85, figs. 1-2. Glenn’s original description.—Shell oval, moderately elevated anteriorly, gently depressed posteriorly ; beak depressed, moderately incurved ; surface of shell with numerous gentle, somewhat irregular, close-set, concentric undulations most prominent on the marginal two-thirds of the surface; meeting of posterior and umbonal slopes marked by a ridge, of posterior and basal margins by an angle; posterior margin bluntly rounded; a car- dinal and a posterior lateral tooth in left valve, two cardinals in right valve; ligament area curved, ridged, and grooved; interior smooth; muscle impressions and pallial margin distinct. This species is characterized chiefly by its elongate shape. The type specimens were reported as coming from Cove Point or Plum Point, which would mean that they were St. Mary’s or Calvert in age. The only specimens in my collection which | could assign to this species are two from zone 14 of the Calvert formation from a short distance south of the mouth of Parker Creel. Some young specimens of /. fraterna marylandica from zone 17 north of Calvert Beach closely resemble this species in out- line. The type specimens of J. ignolea appear to be quite distinct from the average J. fraterna marylandica. The most inflated part of the shell is just anterior to the center, giving a slightly twisted appearance to the shell. A slightly depressed area runs 60 BuLLETIN 94B 224 just anterior to the umbonal ridge. The posterior end is rathe= pointed. Horizon.—Zone 14, Calvert Miocene. Locality.—45. Isoeardia markoéi Conrad (emend.) Plate 10, figs. 1-3 Tsocardia Markoéi Conrad, 1842, Proce. Nat. Inst., Bull. 2, p. 193, pl. 2. fig. 1 (right hand figures only and diagnosis in part); 1845, Fossils of the Medial Tertiary. p. 70, pl. 40, fig. 2 (right hand figures only and diagnosis in part); Glenn, 1904, Maryland Geol. Survey, Miocene, p. 316, pl. 84, figs. 2-3. Conrad’s original description.—Suborbicular: length and height nearly equal; inflated; umbo very prominent, and the beaks profoundly ineurved ; posterior margin direct. arched above, nearly straight below. and obtusely angulated at its junction with the base; base regularly, not profoundly arched; posterior slope slightly sinuous. Glenn, 1904——Conrad has figured in each ease citel above two forms that on comparison of a number of specimens show constant differeness, and his deseription applies partly to one and partly to the other. It he- comes necessary, therefore, to restrict his name, and as the remarkable elevation and profound incurvature of the beaks seem to have been perhaps the most prominent characteristics in his mind—just as they produce the more striking of the two forms—the name J. markoéi will here be used to designate the species with highly elevated, narrow, prolonged, profoundly ineurved beaks, a feature well represented in the right hand drawing of each of his figures. It is about as high as long; posterior margin quite or almost entirely arched; dorsal slope crossed by two or three broad, deep, concentric undulations marking resting stages during growth. Figured specimen.—No. 3958, Paleontological Research Insti- tution. ene Horizon.—Zone 10, Calvert Miocene. Localhties.—3, 9. Isocardia mazlea Glenn Plate 9, figs. 1-3 Tsocardia Markoéi Conrad, 1842, Proc. Nat. Inst., Bull. 2, p. 193, pl. 2, fig. 1 (left hand drawing only and diagnosis in part) ; 1845, Fossils cf the Medial Tertiary, p. 70, pl. 40, fig. 2 (left hand drawing only and diagnosis in part). Isocardia mazlea Glenn, 1904, Maryland Geol. Survey, Miocene, p. 317, pl. 84, figs. 4-5. Glenn’s original description.—Shell rounded, inflated; length greater than height; umbo elevated, broad, short, only moderately incurved, not strongly projecting; dorsal slope crossed by several shallow and at times indistinct concentric undulations; posterior margin curved above, straight below and meeting the base at an obtuse angle to which there extends a flattened ridge which is bordered on the posterior slope by a broad, gently depressed or grooved area. See also remarks under J. markoéi. 225 MarytaANnp MIocENE: SCHOONOVER 61 Figured specimen —No. 3955, Paleontological Research Insti- tution. Horizon.—Zone 10, Calvert Miocene. Localities.—2, 3, 9. Family VENERIDZE Subfamily VENERINA Genus ANTIGONA Schumacher Section ARTENA Conrad Antigona (Antigona) staminea (Conrad) Plate 11, figs. 6-8 Cytherea staminea Conrad, 1839, Fossils of the Medial Tertiary, back cover of No. 1, pl. 24,fig. 1. Cytherea (Antigona) staminea Conrad. Glenn, 1904, Marylanid Geol. Survey, Miocene, p. 314, pl. 76, figs. 6-8. Antigona (Antigona) staminea (Conrad). Palmer, 1927-1929, Paleonto- graphica Americana, vol. 1, No. 5, p. 329, pl. 27, figs. 2, 4-5, 9-11, 14. Conrad’s original description.—Shell subtriangular, thick, with about ten very prominent acute slightly reflected concentric ribs, with an intermediate carina, and crowded minute lamellar strix ; anterior tooth very small; mar- gin crenulated. Length 1 inch. Locality, Calvert County, Md. Glenn, 1904.—Ferm compact, rounded, triangular; valves convex; beak not prominent; ribs perpendicular to the surface and at times as many as sixteen; posterior edge of dorsal slope often marked by a slight ridge caus- ing a slight posterior basal emargination; cardinal teeth three in each valve; anterior lateral tooth in left valve very small and rounded and fitting into a correspondingly small socket in right valve; muscular impressions subequal ; pallial sinus a mere notch. This species is very common and abundant in zone 10 of the Calvert formation. It also occurs in zone 12, south of the mouth of Parker Creek, but was not collected from that zone. As the distribution chart indicates, it was present at every locality but one, at which collections were made from zone 10. That one was locality 13 at Hollin Cliff, and its absence there can be at- tributed to the extremely small size of the collection made there, and the poor condition of the specimens. The collection from this place was obtained by digging in the cliffs with a spade, and it consisted of only a few, poorly preserved specimens. Under these circumstances A. staminea could very easily have been overlooked. The young of this species are more elongate in proportion to their height than the adults. A few specimens were more pointed posteriorly than the average, but there-was no apparent relation- 62 BULLETIN 94B 226 ship between this character and the geographic distribution. The intermediate carina mentioned by Conrad is not a common nor a prominent feature. The ribs are usually more numerous than Conrad’s number would indicate, as many as sixteen being found on many specimens. Suites of specimens from different localities do not show any consistent differences, except in a few forms from the upper thin shell layer of zone 10 between Dares Wharf and Plum Point, (lo- calities 38 and 43). These are slightly larger, less inflated, longer in proportion to their height, and more evenly rounded than typ- ical forms. Only a few specimens were collected from these local- ities, however, so these statements are based on an examination of less than a dozen specimens. This species is not known to occur on the St. Mary’s River, as stated by Dall. Figured specimens.—Nos. 3967-69, Paleontological Research Institution. Horizon.—Zone 10, Calvert Miocene. Localines—1, 36, 4, 2, 5, 3, 48, 9, 02, 43, 38. Genus CHIONE Megerle von Miihlfeld Subgenus LIROPHORA Conrad Three distinct species of Chione are present in the Maryland Miocene, and all three have some value as horizon markers. The species and their ranges are as follows: Radial sculpture present Concentric lamin thickened, rounded, irregular, engl jommimenllhy G@OMIMMOME ooo. nce chee eee C. latilirata Zone 10, Calvert Concentric lamine thickened, flattened, completely Corsi CHOU 21 Teese A igi cum etme ha sally nce Ohh a anes iach wi Bon C. parkeria Zone 14, Calvert Radial sculpture absent Concentric lamine elevated, sharp or rounded, regu- laryibutivdistimet, 337 ul eb ree ee ee eae eee C. alveata Zone 24?, St. Mary’s Chione latilirata was first described from the Calvert formation of the Calvert Cliffs, Maryland, but it ranges through the Upper Miocene and Pliocene, and is still living from Cape Hatteras, Las) bo xj MaryLANpD MiocENE: SCHOONOVER 63 North Carolina, to Rio Grande do Sul, Brazil. In Maryland I have never found it in any beds other than zone Io of the Calvert formation, although Glenn reported it from the Choptank at Greensboro. In view of its range up to the Recent it is somewhat surprising that it has not been found elsewhere in the Maryland Miocene. However, it certainly is not common in any beds other than zone 10, even should further collecting yield a few specimens from other horizons. Chione parkeria was described by Glenn from the Calvert for- mation south of the mouth of Parker Creek, but no information was given regarding its more detailed stratigraphic occurrence. The species occurs in zone 14 of the Calvert formation at this and other localities. It does not occur in zone 10, the main fossil bed of the Calvert formation, at any locality so far as known. It is very common and characteristic of zone 14, and possibly occurs in zone 12. It occurs at almost every locality where zone 14 can be identified, and is frequently associated with /socardia fraterna var. marylancica in a light-brown clay. There may be a valid question as to whether the species is actually limited to zone 14, or whether I have been calling every bed which contained C. parkeria zone 14. At any rate, the species is definitely limited to the upper part of the Calvert formation,—to the beds between zones 12 and 15, inclusive. Chione alveata appears to be limited in Maryland to the St. Mary’s Miocene of the St. Mary’s River, and does not occur at any other Maryland localities of the St. Mary’s formation. Chione latilirata (Conrad) Plate 11, figs. 3-4; Plate 12, figs. 1-3 Venus latilirata Conrad, 1841, Acad. Nat. Sci. Philadelphia Proe., vol. 1, p. 28; 1845, Fossils of the Medial Tertiary, p. 68, pl. 38, fig. 3. Chione (Lirophora) latilirata (Conrad). Dall, 1903, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1298 (not pl. 42, fig. 3). Chione latilirata (Conrad). Glenn, 1904, Maryland Geol. Survey, Mio- cene, p. 309, pl. 77, figs. 3-4, 6 (not fig. 5). Chione (Lirophora) latilirata (Conrad). Palmer, 1927-1929, Paleeonto- graphica Americana, vol. 1, No. 5, pp. 387-388, pl. 41, figs. 12, 12a, 13, 33. 64 BULLETIN 94B 228 Conrad’s original description.—Trigonal, convex, depressed, ribs con- eentric. about 5 or 6 in number, flattened, reflected, irregular, one of them generally very wide; ribs irregularly suleated on the posterior slope; inner margin finely crenulated. Smaller than V. alveata, and with broader, less prominent ribs, which do not diminish in size on the posterior margin. This species is quite variable as it occurs in Maryland. Speci- mens are usually small, though this is partly due to the fact that they are not well preserved, but are soft, and the larger ones break up in collecting. The largest ones I have collected measure about 22 mm. long by 18 mm. high, but forms 17 by 14 mm., or smaller, are much more common. There is considerable variation in the number and breadth of the ribs, the degree to which they are reflected toward the beak and flattened against the disk, and in the closeness of spacing of these ribs. There are commonly five or six major ribs which are variable in size, and may or may not be well plastered to the disk. In addition there are finer ribs on the umbo, which are more numer- ous, and may number as many as six or more, before the broader, more prominent ribs start. Fine, radial, impressed lines appear on the ventral side of each rib in well-preserved specimens. There are no apparent differ- ences between forms from different localities, but the species is much more abundant at the north end of the cliffs near Randle Cliff Beach than further south in the vicinity of Plum Point. Figured specimens.—Nos. 3964, 3905, 3971-73, Paleontological Research Institution. Horizon.—Zone 10, Calvert Miocene. Localities —1, 36, 5, 2, 3, 43, 38, 9. Chione parkeria Glenn Plate 11, figs. 1-2 Chione parkeria Glenn, 1904, Maryland Geol. Survey, Miocene, p. 310, pl. 76, figs. 9-11. Chione (Lirophora) parkeria Glenn. Palmer, 1927-1929, Paleontograp - ica Americana, vol. 1, No. 5, p. 379, pl. 41, figs. 10, 22, 28. Glenn’s original description.—Shell triangular, (op:essed, poste io |7 somewhat cuneiform, anteriorly rounded; beaks projecting, acute, approx- imate; lunule distinct, cordate; base posteriorly emarginate; dorsal surface with about five to eight concentric ribs so perfectly flatiened and closely for] i) | 299 MaryuANp MiocENE: ScHOONOVER appressed to the valve and each other as to become almost obsolete and be marked only by faint undulations and fine concentric impiessed or lami- nated lines; ribs crossed from beak to base by numerous distinct, regular, radiating lines; cardinal teeth three in each valve; laterals none; muscle impressions deep; pallial sinus a slight notch; margin minutely crenu- lated. This species seems to be closely related to C. ulocyma Dall. This species is larger, more pointed and more emarginate pos- teriorly than C. latilirata. The ribs are so well flattened back against the disk that they are scarcely separable. The surface is usually decorticated, but when present it is covered by fine radial, impressed lines, which are more prominent and more widely spaced than those in C. Jatilirata. There are no apparent dif- ferences between forms from different localities. Figured specimens.—No0s. 3962, 3963, Paleontological Research Institution. Horizon.—Zone 14, Calvert Miocene. Localities.—54, 53, 46, 63, 45. Family CORBULIDZ Genus CORBULA (Brugieére) Lamarck The genus, Corbula, is represented in the Maryland Miocene by three subgenera, including four species. The species are all so distinct that they should not be confused. The species and the zones in which they occur are indicated in the following table: Shell large, height 15-30 mm. _______............. C. (Bicorbula) idonea Zones 10, 14, 17, 18, 19. Shell small, height less than 15 mm. Shell elevated, height approx. equal to length Concentric ribs numerous Een G ls etevor Mela es eae St AA eee eee aa C. (Corbula) elevata Zones 5-10. Shell not elevated; length greater than height; length 10 mm. or less Sculpture fine and uniform C. (Caryocorbula) cuneata Zones 10, 17, 19? Sculpture irregular in WiC OATS Ch ya.ctoremliele mo oF cere BO es C. (Caryocorbula) inequalis . Zones 10, 16, 17, 19, 24. Only one of these species, C. elevata, has an especially restricted 66 BULLETIN 94B 230 range. It is abundant in zones 5 through 10, but never occurs above the top of zone 10. It was on the basis of the relative abundance of this species that Shattuck differentiated zones 5-9. The other three species of Corbula all appear for the first time in zone 10, and are present in the more fossiliferous beds of both the Calvert and Choptank formations, With the exception of a single, small, worn specimen from Langley’s Bluff, Maryland, C. 1.onea was not found in the St. Mary’s formation. C. inequal- is and C. cuneata both occur in the St. Mary’s and in the York- town in Virginia. C. imequalis is common, but C. cuneata is always rare wherever it occurs. C. im@qualis is the only Corbula that is common in the St. Mary’s formation. All of these species of Corbula show a strong tendency for the outer layers of the shell substance to peel. One who fails to no- tice this tendency would be very likely to describe as distinct species the peeied and unpeeled forms, particularly in species like C. elevata, which have characteristic ribbing. Subgenus BICORBULA Fischer Corbula idonea Conrad Plate 12, figs. 10-14 Corbula idonea Conrad, 1833, Am. Jour. Sci., lst ser., vol. 23, p. 341; 1838, Fossils of the Medial Tertiary, p. 6, pl. 10, fig. 6. Corbula (Corbula) idonea Conrad. Glenn, 1904, Maryland Geol. Survey, Miocene, p. 279, pl. 67, figs. 1-3. Conrad’s original description.—Shell subtriangular, convex, thick, ob- securely undulated; with a fold on the posterior submargin and the ex- tremity angular; basal margin acute; cardinal tooth very thick and ele- vated. Length, one inch. There seem to be no consistent differences in specimens of this species from different beds and localities. The one excep- tion is that forms from the ‘Choptank formation average slightly larger than those from the Calvert. However, this slight differ- ence in size is not sufficient for separating Choptank from Cal- vert forms, unless one uses, in addition, the unreliable criterion of color. Young specimens are longer in proportion to their height than adults, and they are more pointed posteriorly. The rostrum 1s more conspicuous in the young forms. Right valves are more 531 MARYLAND M10cENE: ScHOONOVER 67 strongly convex and have the beaks more curved than left valves. The posterior dorsal margin of the right valve is concave; that of the left is straight or slightly convex. The only surface ornamentation consists of irregular growth lines and gentle concentric undulations. On the right valve the growth lines in the umbonal region are fine and regular, resem- bling those of C. cuneata. Some valves when peeled may show two faint, broad, radial ribs which divide the shell into three unequal sections, the anterior of which is the broadest. These ribs do not show well, if at all, on specimens that have not been peeled. They are more common and conspicuous on left than on right valves. Occasional specimens show a finer, more regular, radial structure when peeled, but this is not common. Some old speci- mens are considerably thickened. Figured specimens.—Nos. 3977-79, Paleontological Research Institution, Horizons.—Zones 10, 14, Calvert Miocene; zones 17, 18, 19, Choptank Miocene; zone ?, St. Mary’s Miocene (one specimen only). LOCOMMESAL, Ay 2, B MS, AB, ©8 FB. AQ’ BA, 27, 2S, ddl, S77, 6, ©, 595 ADs 38 55; US, SEs Bye Subgenus CORBULA, s. s. (or VARICORBULA Grant and Gale, 1931) Corbula elevata Conrad Plate 12, figs. 4-9 Corbula elevata Conrad, 1838, Fossils of the Medial Tertiary, p. 7, pl. 4, fig. 3; Whitfield, 1894, U. S. Geol. Survey Mon. 24, p. 86, pl. 15, figs. 15-19; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 280, pl. 67, figs. 4-5. Conrad’s original description.—Shell triangular, equilateral, height greater than the length; inferior valve ventricose, with regular numerous concentric impressed lines, which disappear on the posterior slope; umbo profoundly elevated; posterior slope with an obtuse furrow descending from the beak; extremity narrowed, slightly emarginate. Whitfield, 1894——The form is triangularly ovate in outline, slightly in- equilateral, and much inflated, both valves being quite ventricose; the beaks are large and very gibbous, that of the deeper valve much the largest. Umbonal ridge distinct in each valve, but not strongly marked. Surface of the valves variable in their markings, usually with impressed concen- trie lines, but sometimes developing concentric ridges more or less rounded, but indistiaet on the umbonal slope . .. In the interior the hgamental pit of the larger valve is very large and deep, excavating the inner face of the beak in most instances. The tooth is also very large and strong. 68 Buiietin 94B 939 Whitfield’s drawings show forms a little higher in proportion to their length than any I have seen. One rather important characteristic which has apparently gone unnoticed is that the heavy concentric ribs are confined to the right valves and do not appear on the left valves. The left valves are usually peeled, but when the outer shell layer is still present it has only rather fine, irregular lines which could scarcely be re- garded as anything more than growth lines. The left valves of C. elevata are rather difficult to separate from the young of C. idonea. The latter are slightly longer in proportion to their height, less inflated, and more pointed poster- iorly. ‘The basal margin of C. idonea is reflected upward more at the posterior end. In right valves of C. elevata the socket and resilial pit make a sharp inverted V, offset from the dorsal mar- gin, while in young C. idonea of similar size the V is absent and the dorsal margin is more evenly rounded. The resilial pit of the latter is more inclined to the plane between the valves. C. idonea 1s less perfectly equilateral than C. elevata. Figured specimens.—Nos. 3974-76, Paleontological Research Institution. Horizons.—Zones 5-10, Calvert Miocene. Wocaliives:——At,, AOan 52, 20715, 145.35, GOn Sake eee One 9, 13, 43- Corbula cuneata Say Corbula cuneata Say, 1824, Acad. Nat. Sci. Philadelphia, Jour. 1st ser., vol. 4, p. 152, pl. 13, fig. 3; Conrad, 1838, Fossils of the Medial Ter- tiary, p. 5, pl. 3, fig. 3 (right hand fig.). Corbula (Cuneocorbula) cuneata Say. Dall, 1898, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 854; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 282, pl. 67 figs. 15-19. Say’s original description.—Shell transversely ovate-trigonal, acutely angulated or somewhat rostrated before, and depressed on the anterior slope, which is separated from the disk by a subacute line: surface of both valves similarly striate with equal, elevated, equidistant lines, forming grooves between them; the striae on the smaller valve are rather more distant: umbones not prominent. Length of the larger valve hardly more than the fourth of an inch, breadth more than two-fifths of an inch. This species is much too rare to be of stratigraphic value. Glenn noted that when it is found at all it is more commonly at LS 33 MARYLAND MIocRNE: SCHOONOVER 69 the Jones Wharf horizon, or zone 17. It is more elongate and much thinner-shelled than C. inequalis, Glenn observed that its striz are “much finer and more close set, equal, and equidistant” than in C. inequalts. Hlorizons.—Zones 10, Calvert; zones 17, 19?, Choptank Mio- cene. ILOCOMMES—=Fil, Ay BS 27 BE, wa, ©, KOR Pins, Subgenus CARYOCORBULA Gardner Corbula inequalis Say Corbula inaequale Say, 1824, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 153, pl. 13, fig. 2 (fig. at center of page) ; Conrad, 1838, Fossils of the Medial Tertiary, p. 6, pl. 3, fig. 2, left hand fig. under 3. Corbula (Cuneocorbula) inaequalis Say. Dall, 1898, Wagner Free Inst. Sei. Trans., vol. 3, pt. 4, p. 853; Glenn, 1904, Maryland Geol. Survey, Miocene, p. 281, pl. 67, figs. 6-14. Corbula (Caryocorbula) inequalis Say. Mansfield, 1932, Florida Geol. Survey Bull. 8, p. 158, pl. 32, figs. 12-13. Say’s original description.—Shell convex, transversely ovate-trigonal, rough, with unequal coarse wrinkles: anterior margin with a very acute but short rostrum at its inferior termination, separated from the disk by an acute line: base rounded and a little contracted near the anterior angle: umbones not prominent. Length two-fifths, breadth rather more than half an inch. This species has a different aspect from the preceding (C. cwneata) ; it is longer in proportion to its width, more convex, and the wrinkles, though prominent, are altogether destitute of that equality which distinguishes those of the other shell. As noted by both Glenn and Mansfield, this species is quite variable in size, thickness, outline of the shell, and the nature and strength of the ornamentation. Glenn observed that: Specimens from the Jones Wharf horizon are often more finely striated than those from the Calvert formation, while those from the St. Mary’s formation are largest, thickest and have the most rounded base. All agree in having rather coarse, irregular, concentric undulations. Horizons.—Zone 10, Calvert; zones 16-19, inclusive, Choptank Miocene. ILOCOMMS 1, BO, Al, 2, By ABs AS, ©, 12, OR A, AAle ail, Ar a 0, 59, 7; 49; 33, 55, 15, 51. 70 BuLLETIN 94B 934. S IAINIGIRAUPISUUC ANID) JUNIE, IDICS IRIS ON) Ol? SIMECWES In the following section lists of species are given for each stratigraphic horizon and locality where the writer has made eCllecions, Osily goecies colllececl iy wae Wiser aire ina cluded. The lists are as complete as possible, except that some of the extremely small and more rare species are omitted. Care- ful identification of all of these is impossible at present. However, these rare forms have relatively little importance in this study. The lists are arranged (1) according to stratigraphic horizons, the lowest horizon being given first, and (2) according to locali- ites. The localities, under each zone, are arranged in consecutive order beginning at the north end of the cliffs and working south. Inland localities are listed after those along the Calvert Cliffs. For a more detailed description of the localities than is given at the heading of each list, reference should be made to the locality list. CALVERT FORMATION Zones 4, 5-9 From the beginning of the cliffs, south of Chesapeake Beach. Loeality 19, zone 4, Ostrea percrassa bed. Ostrea percrassa Conrad Same locality, but from zone 5? Isocardia ef. I. fraterna var. marylandica, n. var. Cardium sp. indet. Same locality, zones 5-9? Corbula elevata Conrad North of Randle Cliff Beach Locality 42, zone 5? Thin fossil band just above the oyster bed. Yoldia sp. indet. (large form) Chlamys madisonius (Say) Isocardia ef. fraterna var. marylandica, n. var. ?Macoma lenis (Conrad) Loeality 41, zone 6? Corbula elevata beds. Nucula proxima Say Yoldia cf. Y. levis (Say) Atrina harrisii Dall Pecten humphreysii Conrad Amusium cerinum (Conrad) Modiolus dueatellii (Conrad) Thracia conradi Couthouy Corbula elevata Conrad Corbula inequalis Say Vermetus virginicus (Conrad) ? io) (Shi MaryLAND MI0cENE: SCHOONOVER South of Randle Cliff Beach Loealicy 40-b, zone 3? From three feet below the oyster bed. Yoldia cf. Y. levis (Say) Cardium sp. indet. ?Macoma lenis (Conrad) Loeality 40, zone 4, Ostrea percrassa bed. Ostvea pererassa Conrad Calamys madisonius (Say) Calamys madisonius, var. near marylandicus Also observed, but not collected: Ostrea sp. indet. Chlamys madisonius (Say) Tsoeardia, ef. I. fraterna marylandica, n. var. Venus sp. indet. Panopea, probably P. whitfieldi Dall Kephora_ sp. indet. Loeality 40-a, zone 6? Corbula elevata beds. Peecten humphreysii Conrad Corbula elevata Conrad Loeality 52, zones 5-9 Atrina harrisii Dall Peeten humphreysii Conrad Chlamys madisonius (Say) Modiolus dueatellii (Conrad) Thracia conradi Couthouy Corbula elevata Conrad \~rth of Plum Point Beach Locality 39, zone 5 or 6? Pecten humphreysii Conrad Chlamys madisonius (Say) Corbula elevata Conrad Zone 10 Loealities 1, 14, 35, zone 10, north of Randle Cliff Beach. Pelecypods Nucula proxima Say Nucula prunicola Dall Leda liciata (Conrad) Glyeymeris parilis (Conrad) Anadara subrostrata (Conrad) Atrina harrisii Dall Ostrea pererassa Conrad? Ostrea selleformis var. thomasii Glenn? Peecten humphreysii Conrad Chlamys madisonius (Say) Chlamys madisonius (Say), variety Chlamys coccymelus (Dall) Amusium cerinum (Conrad) Modiolus dueatellii (Conrad) ‘Astarte cuneiformis Conrad | Astarte cuneiformis var. obesa Dall | Astarte cuneiformis var. parma Dall \Astarte cuneiformis var. calvertensis Glenn Huerassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) foremani (Conrad) el 72 BULLETIN 948 236 Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Phacoides trisuleatus (Conrad) Phacoides prunus Dall? Cardium leptopleurum Conrad Cardium eraticuloide Conrad Dosinia acetabulum Conrad Maeroeallista marylandica (Conrad) Antigona staminea (Conrad) Chione latilirata (Conrad) Metis biplicata (Conrad) Tellina producta Conrad Tellina declivis Conrad? Semele carinata (Conrad) Semele subovata (Say) Mactra clathrodon Lea ?Paramya subovata (Conrad) Corbula idonea Conrad Corbula elevata Conrad Corbula inequalis Say Corbula cuneata Say? Saxicava arctica (Linné) Panopea americana Conrad Panopea whitfieldi Dall Gastropods Acteon shilohensis Whitfield Terebra curvilineata var. whitfieldi Martin Pleurotoma bellacrenata Conrad Mangilia parva (Conrad) Drillia pseudeburnea (Heilprin) Fulgur sp. indet. (young) Siphonalia devexa (Conrad) Nassa peraltoides Martin Eephora tricostata Martin Scala marylandica Martin? Seala calvertensis Martin Niso lineata (Conrad) Odostomia conoidea (Brocchi) ? Turbonilla interrupta (Totten) Cerithiopsis calvertensis Martin Vermetus graniferus (Say) Turritella indenta Conrad Turritella plebeia Say Turritella variabilis var. B. Martin Turritella variabilis var. cumberlandia Conrad Solarium trilimeatum Conrad Crucibulum costatum (Say) Calyptrea aperta (Solander) Xenophora conchyliophora (Born) Polynices heros (Say) Polynices hemicryptus (Gabb) Sinum fragilis (Conrad) Se 237 MaryYLAND MIOCENE: SCHOONOVER Calliostoma calvertanum Martin Calliostoma philanthropus (Conrad) Teinostoma calvertense Martin Teinostoma liparum (H. C. Lea) Fissuridea marylandica (Conrad) Scaphopods * Dentalium attenuatum Say Dentalium danai Martin (not of Meyer) Cadulus thallus (Conrad) Loeality 36, zone 10, Calvert, south of Randle Cliff Beach Pelecypods Nucula proxima Say Nucula prunicola Dall Nuceula taphria Dall Leda liciata (Conrad) Leda liciata var. amydra Dall Leda, n. sp.? Glyeymeris parilis (Conrad) Anadara subrostrata (Conrad) Atrina harrisii Dall \ Pedalion maxillata (Deshayes) Ostrea selleformis var. thomasii Glenn Peeten humphreysii Conrad Chlamys madisonius (Say) Chlamys madisonius (Say), variety Modiolus dueatellii Conrad? ' Astarte cuneiformis Conrad Astarte cuneiformis var. obesa Dall Crassinella duplinianus (Dall) Euerassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Phacoides trisuleatus var. whitfieldi Dall Erycina sp. indet. Cardium leptopleurum Conrad Cardium eraticuloide Conrad Cardium, n. sp. Dosinia acetabulum Conrad Macroeallista marylandica (Conrad) Antigona staminea (Conrad) Chione latilirata (Conrad) Venus rileyi Conrad Metis biplicata (Conrad) Tellina producta Conrad Semele carinata (Conrad) Mactra clathrodon Lea Corbula elevata Conrad Saxicava arctica (Linné) Panopea whitfieldi Dall Gastropods Acteon shilohensis Whitfield 7‘ Terebra eurvilineata var. whitfieldi Martin Pleurotoma bellacrenata Conrad 73 BULLETIN 94B 238 Pleurotoma ealvertensis Martin Surecula marylandica Conrad Caneellaria sp. indet. Marginella ealvertensis Martin Fulgur sp. indet. Siphonalia devexa (Conrad) Nassa trivittatoides (Whitfield) Nassa peraltoides Martin Eephora tricostata Martin Seala marylandica Martin Eulima eborea Conrad Eulima migrans Conrad Turbonilla interrupta (Totten) Cerithiopsis calvertensis Martin? Vermetus graniferus (Say) Vermetus virginicus (Conrad) Turritella indenta Conrad Turritella plebeia Say Turritella variabilis var. cumberlandia Conrad Turritella variabilis var. B Martin Turritella variabilis var. C Martin Solarium trilineatum Conrad Crucibulum costatum (Say) Crucibulum multilineatum (Conrad) Calyptrea aperta (Solander) Polynices heros (Say) Polynices hemicryptus (Gabb) Sinum fragilis (Conrad) ; Calliostoma aphelium Dall ‘ans Calliostoma philanthropus (Conrad) ' Teinostoma calvertense Martin Teinostoma liparum (H. C. Lea) ' Wwe Teinostoma greensboroénse Martin? j Scaphopods Dentalium attenuatum Say Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Cadulus newtonensis Martin (not Meyer and Aldrich) Loeality 4, zone 10, Calvert, north of Captain Hubbard’s. : Pelecypods ae Glyeymeris parilis (Conrad) Chlamys madisonius (Say) Chlamys madisonius bassleri Tucker-Rowland? Astarte cuneiformis Conrad Kuerassatella melina (Conrad) Saxolucina (Megaxinus) foremani (Conrad) Phacoides crenulatus (Conrad) Antigona staminea (Conrad) Corbula idonea Conrad Corbula inequalis Say Gastropods Kephora tricostata Martin Turritella indenta Conrad Turritella variabilis var. cumberlandia Conrad MaryYLAND MI0cENE: SCHOONOVER 75 Fissuridea marylandica (Conrad) Locality 5, zone 10, Calvert, from roadeut along main road north of the entrance to Camp Roosevel.. Pelecypods Glyeymeris parilis (Conrad) Anadara subrostrata (Conrad) \Pedalion maxillata (Deshayes) Pecten humphreysii Conrad Chlamys madisonius (Say) Astarte cuneiformis Conrad Eucrassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Antigona staminea (Conrad) Chione latilirata (Conrad) Semele carinata (Conrad) Corbula elevata Conrad Saxicava aretica (Linné) Gastropods Turritella indenta Conrad Turritella variabilis var. B Martin Scaphopods Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Loeality 2, zone 10, Calvert, south of Camp Roosevelt. Pelecypods Nuecula proxima Say Nucula tapbria Dall Leda liciata (Conrad) Leda liciata var. amydra Dall Glycymeris parilis (Conrad) Anadara subrostrata (Conrad) Pedalion maxillata (Deshayes ) Ostrea sp. indet. (young) Chlamys madisonius (Say) Chlamys madisonius bassleri Tucker-Rowland? Anomia sp. indet. Modiolus dueatellii (Conrad ) / Astarte cuneiformis Conrad Astarte cuneiformis var. obesa Dall Astarte cuneiformis var. parma Dall Astarte cuneiformis var. calvertensis Glenn Astarte exaltata Conrad Euerassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) foremani (Conrad ) Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Phacoides prunus Dall Erycina speciosa Glenn? Cardium leptopleurum Conrad? “A BULLETIN 94B 240 Isoeardia mazlea Glenn Dosinia acetabulum Conrad Maeroeallista marylandiea (Conrad) Callocardia sp. indet. (young) Antigona staminea (Conrad) Chione latilirata (Conrad) Venus rileyi Conrad Tellina producta Conrad Tellina declivis Conrad? Semele carinata (Conrad) Mactra clathrodon Lea Corbula idonea Conrad Corbula elevata Conrad Corbula inxqualis Say Saxicava arctica (Linné) Panopea whitfieldi Dall Gastropods Volvula iota var. patuxentia Martin? Retusa conulus (Deshayes) Cylichna calvertensis Martin Terebra curvilineata var. calvertensis Martin Sureula marylandiea (Conrad) Mangilia parva (Conrad) Hephora tricostata Martin Seala sayana Dall Niso lineata (Conrad) Vermetus virginicus (Conrad) Turritella plebeia Say Turritella indenta. Conrad Turritella variabilis var. cumberlandia Conrad Turritella variabilis var. B Martin Turritella variabilis var. exaltata Conrad Tachyrhynehus perlaqueatus (Conrad) Crucibulum costatum (Say) Calyptrea aperta (Solander) Crepidula fornicata (Linné) Polynices heros (Say) Polynices hemieryptus (Gabb) Calliostoma philanthropus (Conrad) Calliostoma calvertanum Martin Fissuridea marylandica (Conrad) Scaphopods ‘ Dentalium attenuatum Say Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Localities 3, 11, 28, zone 10, Calvert, south of old Plum Point Wharf. Pelecypods Nucula proxima Say Nueula prunicola Dall Nueula taphria Dall 241 MARYLAND MIOCENE: SCHOONOVER Nucula sinaria Dall? Leda liciata (Conrad) Leda liciata var. amydra Dall Leda, n. sp.? Glycymeris parilis (Conrad) Anadara subrostrata (Conrad) Anadara elnia (Glenn) Ostrea pererassa Conrad Pecten humphreysii Conrad Chlamys madisonius (Say) Chlamys madisonius bassleri Tucker-Rowland ? Amusium cerinum (Conrad) Anomia sp. indet. ‘Modiolus dueatellii (Conrad) Astarte cuneiformis Conrad Astarte cuneiformis var. parma Dall Astarte cuneiformis var. calvertensis Glenn Astarte exaltata Conrad Astarte thomasii Conrad Crassinella duplinianus (Dall) Huerassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) foremani (Conrad) Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Phacoides trisuleatus var. whitfieldi Dall Phacoides prunus Dall Erycina sp. indet. ?Solecardia cossmanni Dall Cardium eraticuloide Conrad Cardium laqueatum Conrad Tsocardia markoéi Conrad Isocardia mazlea Glenn Dosinia acetabulum Conrad Macroeallista marylandica (Conrad) Antigona staminea (Conrad) Chione latilirata (Conrad) Venus rileyi Conrad = Tellina producta Conrad Tellina umbra Dall Abra marylandica Glenn? Semele carinata (Conrad) Ensis ensiformis (Conrad) Spisula sp. indet. Mactra clathrodon Lea Corbula idonea Conrad Corbula elevata Conrad Corbula ineequalis Say Saxicava arctica (Linné) Panopea whitfieldi Dall Panopea goldfussii Wagner Panopea americana Conrad Gastropods Pleurotoma bellacrenata Conrad 77 78 BULLETIN 94B 242 Sureula marylandica Conrad Manugilia parva (Conrad) Cancellaria alternata Conrad Caneellaria prunicola Martin Seaphella solitaria (Conrad) Scaphella typus (Conrad) Fulgur spiniger (Conrad), variety Fulgur coronatum Conrad Fulgur coronatum var. rugosum Conrad Siphonalia devexa (Conrad) Ptychosalpinx lienosa Conrad Columbella calvertensis Martin Eephora tricostata Martin Kephora quadricostata var. umbilicata (Wagner) Keala sayana Dall? Seala marylandica Martin Scala pachypleura Conrad Eulima eborea Conrad Eulima migrans Conrad Niso lineata (Conrad) Odostomia conoidea (Brocchi) Odostomia marylandica Martin Turbonilla interrupta (Totten) Cerithiopsis calvertensis Martin? Vermetus graniferus (Say) ? Vermetus virginicus (Conrad) Turritella indenta Conrad Turritella plebeia Say Turritella plebeia var. A Martin Turritella plebeia var. B Martin Turritella variabilis var. cumberlandia Conrad Turritella variabilis var. exaltata Conrad Turritella variabilis var. B Martin Turritella variabilis var. C Martin Turritella equistriata Conrad? Solarium trilineatum Conrad Rissoa marylandica Martin Crucibulum costatum (Say) Calyptrea aperta (Solander) Crepidula fornicata (Linné) Crepidula fornicata (Linné), variety Crepidula plana Say Xenophora conchyliophora (Born) Polynices heros (Say) Polynices hemicryptus (Gabb) Calliostoma philanthropus (Conrad) Teinostoma calvertense Martin Teinostoma liparum (H. C. Lea) Teinostoma, n. sp. Fissuridea griscomi (Conrad) Fissuridea marylandica (Conrad) 13%) Maryuanp MiocENE: SCHOONOVER Scaphopods Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Loeality 48 zone 10, Calvert, south of old Plum Point Wharf. Pelecypods Nucula prunicola Dall Nuecula taphria Dall Leda liciata (Conrad) Leda liciata var. amydra Dall Glyeymeris parilis (Conrad) Anadara subrostrata (Conrad) Peeten humphreysii Conrad Chlamys madisonius (Say) Anomia sp. indet. Modiolus duestellii (Conrad) Astarte cuneiformis Conrad Astarte cuneiformis var. obesa Conrad Astarte cuneiformis var. parma Dall Astarte cuneiformis var. calvertensis Glenn Astarte exaltata Conrad Astarte thomasii Conrad Enerassatella melina (Conrad) Venerieardia granulata Say Saxolucina (Megaxinus) foremani (Conrad) Saxolucina (Megaxinus) anodonta (Conrad) Phacoides erenulatus (Conrad) Phaecoides prunus Dall Cardium laqveatum Conrad Tsoeardia mazlea Glenn? Dosinia acetabulum Conrad M>croeallista marylandica (Conrad) Antigona stam*nea (Conrad) C>ione latilirata (Conrad) Venus rileyi Conrad Tellina producta Conrad Semele carinata (Conrad) Maetra clathrodon Lea Corbula idonea Conrad Corbula elevata Conrad Corbula inequalis Say Saxicava arctica (Linné) Gastropods Seaphella solitaria (Conrad) Scaphella typus (Conrad) Fulgur coronatum var. rugosum Conrad Siphonalia devexa (Conrad) Seala pachypleura Conrad Niso lineata (Conrad) Eephora tricostata Martin Pyrula harrisii Martin Vermetus graniferus (Say) Vermetus virginicus (Conrad) 79 80 BULLETIN 94B 244 Turritella plebeia Say Turritella indenta Conrad Turritella variabilis var. cumberlandia Conrad Turritella variabilis var. exaltata Conrad Turritella variabilis var. A Martin Crucibulum costatum (Say) Calyptrea aperta (Solander) Crepidula plana Say Xenophora conchyliophora (Born) Polynices heros (Say) Fissuridea marylandiea (Conrad) Scaphopods Dentalium attenuatum Say Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Locality 43, wpper part of zone 10, Calvert, south of old Plum Point Wharf. Pelecypods Nueula taphria Dall Ostrea selleformis var. thomasii Glenn? Chlamys madisonius (Say) Anomia sp. indet. (young) Astarte cuneiformis Conrad Astarte exaltata Conrad Astarte thomasi Conrad Kucrassatella melina (Conrad) Venericardia granulata Say Cardium sp. indet. (young) Isocardia fraterna var. marylandica, n. var. Antigona staminea (Conrad) Chione latilirata (Conrad) Corbula idonea Conrad Corbula inzqualis Say Gastropods Seala expansa (Conrad) Seala pachypleura (Conrad) Vermetus virginicus (Conrad) Turritella variabilis var. exaltata Conrad Fissuridea marylandica (Conrad) Locality 38, upper part of zone 10, Calvert, north of Dares Beach. Pelecypods Atrina harrisii Dall Ostrea selleformis var. thomasii Glenn? Chlamys madisonius (Say) Anomia sp. indet. Astarte cuneiformis Conrad Astarte thomasii Conrad EHuerassatella melina (Conrad) Cardium leptopleurum Conrad Antigona staminea (Conrad) Dosinia acetabulum Conrad Chione latilirata (Conrad) Venus rileyi Conrad Corbula inzqualis Say Panopea whitfieldi Dal} MARYLAND MIocENE: SCHOONOVER Gastropods Vermetus virginicus (Conrad) Turritella variabilis var. eumberlandia Conrad Fissuridea marylandica (Conrad) Loeality 62, zone 10, Calvert, Hollin Cliff. Pelecypods Ostrea percrassa Conrad Pecten humphreysii Conrad Calamys madisonius (Say) Calamys madisonius var. near marylandicus Astarte cuneiformis Conrad Venericardia granulata Say Corbula elevata Conrad Corbula inzequalis Say Gastropods Turritella indenta_ Conrad Scaphopods ; Dentalium danai Meyer? Additional species observed, but not collected: Pedalion maxillata (Deshayes) Antigona staminea (Conrad) Loeality 13, zone 10, Calvert Hollin Cliff. Pelecypods Nucula sp. indet. Anadara subrostrata (Conrad) Atrina harrisi Dall Pedalion maxillata (Deshayes) Ostrea pererassa Conrad Chlamys madisonius (Say) Astarte cuneiformis Conrad Venericardia granulata Say Phacoides crenulatus (Conrad) Venus sp. indet. Antigona staminea (Conrad) Corbula elevata Conrad Corbula inequalis Say Martesia ovalis (Say) ? Gastropods Eephora (fragment) Turritella indenta Conrad Turritella variabilis Conrad Additional species observed, but not collected: EKucrassatella melina (Conrad) Cardium sp. indet. Dosinia acetabulum Conrad Locality 9, zone 10, Calvert, ‘‘Old Walls Place,’’ Charles County. Pelecypods Nucula proxima Say Leda liciata (Conrad) Leda liciata var. amydra Dall Glyeymeris parilis (Conrad) 8] 82 BULLETIN -:B 246 Anadara subrostrata (Conrad) Pedalion maxillata (Deshayes) Chlamys madisonius (Say) Amusium cerinum (Conrad) Anomia_ sp. indet. Modiolus dueatellii (Conrad) Astarte cuneiformis Conrad Astarte cuncifoimis var. obesa Dall Astsrte cuneifoimis var. calvertensis Glenn Astarte exaltata Conrad Astarie thomasii Conrad Hucrassatella melina (Conrad) Venericardia granulata Say Saxolucina (Megaxinus) foremani (Conrad) Saxolucina (Megaxinus) anodonta (Say) Phacoides crenulatus (Conrad) Phacoides trisuleatus (Conrad) Phacoides prunus Dall Hrycina sp. indet. Cardium eraticuloide Conrad Cardium laqueatum Conrad Isoeardia markoéi Conrad Jsocardia mazlea Glenn Dosinia acetabulum Conrad Macroeallista marylandica (Conrad) Callocardia subnasuta (Conrad) Antigona staminea (Conrad) Chione latilirata (Conrad) Venus rileyi Conrad Tellina declivis Conrad Tellina sp. indet. Semele carinata (Conrad) Mactra clathrodon Lea Corbula idonea Conrad Corbula elevata Conrad Corbula inzequalis Say Saxicava arctica (Linné) Panopea whitfieldi Dall Gastropods Acteon shilohensis Whitfield Retusa conulus (Deshayes) Retusa calvertensis Martin Pleurotoma communis var. protocommunis Martin Sureula rugata (Conrad) Mangilia parva (Conrad) Drillia pseudeburnea (Heilprin) Marginella calvertensis Martin Seaphella typus (Conrad) Scaphella solitaria (Conrad) Fulgur coronatum var. rugosum Conrad Siphonalia devexa (Conrad) Ptychosalpinx lienosa (Conrad) Hephora tricostata Martin . F 247 MaryLaNnp MiocENE: ScCHOONOVER 83 Kephora quadricostata var. umbilicata (Wagner ) Seala sayana Dall Seala prunicola Martin Seala pachypleura (Conrad) Hulima migrans Conrad Odostomia conoidea (Broechi) Turbonilla gubernatoria Martin? Cerithiopsis calvertensis Martin Vermetus graniferus (Say) Vermetus virginicus (Conrad) Turritella indenta Conrad Turritella plebeia Say Turritella variabilis var. exaltata Conrad Turritella variabilis var. cumberlandia Conrad Crucibulum costatum (Say) Calyptrea aperta (Solander) Crepidula fornicata (Linné) Xenophora conchylophora (Bon) Polynices heros (Say) Calliostoma philanthropus (Conrad) Teinostoma calvertense Martin Teinostoma lparum (H. C. Lea) Fissuridea marylandica (Conrad) Scaphopods Dentalium attcnuatum Say Dentalium danai Martin (not Meyer) Cadulus thallus (Conrad) Zone 14 Locality 54, zone 14, Calvert, north of Randle Chiff Beach. Pelecypods Tsocardia fraterna var. marylandica, n. var. Chione parkeria Glenn Locality 53, zone 14, Calvert, immediately south of old Plum Point Wharf. Pelecypods Chlamys madisonius (Say) Anomia sp. mdet. Astarte cuneiformis Conrad Kuerassatella melina (Conrad) Diplodonta subvexa (Conrad) Jsocardia fraterna var. marylandica, n. var. Dosinia acetabulum Conrad Chione parkeria Glenn Corbula idonea Conrad Corbula ingequalis Say Gastropods Turritella variabilis var. A Martin Locality 46, zone 14, Calvert, 2-3 miles south of old Plum Point Whar‘. Pelecypods Chlamys madisonius (Say) Anomia sp. indet. 84 BuLLETIN 94B 248 Chione parkeria Glenn Locality 63, zone 14, Calvert, north of Dares Beach. Pelecypods Calamys madisonius (Say) Anomia aculeata Gmelin Astarte cuncifoimis Conrad Isocardia fraterna var. marylandica, n. var. Chione parkeria Glenn Loeality 45, zone 14, Calvert, from south of the mouth of Parker Creek to Governor Kun. Pelecypods Chlamys madisonius (Say) Chlamys madisonius near C. marylandicus (Wagner) Anomia sp. indet. Astarte castrana Glenn? Euerassatella melina (Conrad) Isocardia fraterna var. marylandica, n. var. Isocardia ignolea Glenn? Venus mercenaria Linné Chione parkeria Glenn Lucinoma contracta (Say) Corbula idonea Conrad Gastropods Eephora tricostata Martin Hephora quadricostata var. umbilicata (Wagner) Locality 26, zone 14, Calvert, north of Governor Run. Pelecypods Chlamys madisonius (Say) Anomia aculeata Gmelin Lucinoma contracta (Say) Cardium laqueatum Conrad Isocardia fraterna var. marylandica, n. var. Dosinia acetabulum Conrad Venus campechiensis var. capax (Conrad) ? Gastropods Eephora tricostata Martin Eephora quadricostata var. umbilicata (Wagner) CHOPTANK FORMATION Zone 16 Locality 23, zone 16, Choptank, north of Calvert Beach. Pelecypods Yoldia levis (Say) Anadara staminea Say ~Pedalion maxillata (Deshayes) ~Chlamys madisonius (Say) Pandora crassidens Conrad? 249 A Loeality 24, zone 16, Choptank, south of Calvert Beach. MarytaAnp Mt1ocENE: SCHOONOVER < Astarte thisphila Glenn ..Huerassatella turgidula (Conrad) Lucinoma contracta (Say) Phacoides crenulatus (Conrad) Diplodonta subvexa (Conrad) Cardium sp. indet. “vIsocardia fraterna var. marylandica, n. var. Dosinia acetabulum Conrad Callocardia subnasuta (Conrad) Venus plena (Conrad) Abra longicallus (Seacchi) Semele carinata (Conrad) Asaphis centenaria (Conrad) Ensis ensiformis Conrad Spisula delumbis (Conrad) ? Mactra clathrodon Lea ‘Corbula idonea Conrad Corbula inequalis Say Panopea whitfieldi Dall Gastropods Hephora tricostata Martin Turbonilla interrupta (Totten) Vermetus graniferus (Say) “Turritella plebeia Say yf J Turritella variabilis var. cumberlandia Conrad Polynices heros (Say) Teinostoma liparum (H. C. Lea) Scaphopods Cadulus thallus (Conrad) _Pelecypods ‘ Chlamys madisonius (Say) -Euerassatella turgidula (Conrad) u, t ite Sy 7 oP VG Lie) & shih & Yio aed XY. (Nes. 55-58). 314 pp., 80 pls. Mihjc pracy ieee magne ce Para 6.00 Mainly Heuadoran, Peruvian and Mexican Tertiary forams and mollusks and Paleozoic fossils. XVI. (Nos. 59-61). 140 pp., 48 Dise oe eS 5.006 Venezuela and Trinidad Tertiary Mollusca. XVII. (Nos. 62-63). 283 pp., 33 pls. ——-——-_-_-----__--__--—— 6.00 Peruvian Tertiary Mollusca. XVIII. (Nos. 64-67). 286 pp., 29 pls. —---—-——--—---- 6,00 Mainly Tertiary Mollusca and Cretaceous corals. XIX. (No. 68). 272 pp.; 24 pls. ———-_--_-_-_---—----__-- plore 5.00 Tertiary Paleontology, Peru. KX. (Nos. 69-70C). 266 pp., 26 pls. —————-—-_----____--—- 6.00 Cretaceous and Tertiary Paleontology of Peru and Cuba. XXI. (Nos. 71-72). 321 pp., 12 pls. ———-_____--_—-_--_-_-_—_-—-— 5.00 Paleozoic Palecntology and Stratigraphy. XXII. (Nos. 73-76). 356 pp., 31 pls. ——-___--—-_---_--->-—-—--—— 7.00 Paleozoic Paleontology and Tertiary Foraminifera. XXIII. (Nos. 77-79). 251 pp., 35 Bish 2 Sees oer eee DOG Corals, Cretaceous microfauna and biography of Conrad, XXIV. (Nos, 80-87). 334 pp., 27 pls. —__--—--_---______----—- 6.00 Mainly Paleozoic faunas and Tertiary Mollusca. XXV. (Nos. 88-94B). 306 pp., 30 pls. —-————--—----__-_------ 7.00 Paleozoic fossils of Ontario, Oklahoma and Colombia, Mesozoic echinoids, California Pleistocene and Maryland Miocene mollusks. XXVI. (Nos. 95, 96, 97-) not complete. 300 pp., Adap ls; obisie ros 4,50 Florida Recent marine shells, Texas Cretaceous fossils and Cuban Cretaceous corals. PALHONTOGRAPHICA AMERICANA Volume I. (Nos. 1-5), 354 pp., 82 pls. ———_____-_-____---- $ 8.00 Monographs of arcas, Lutetia, rudistids and venerids. II. (Nos. 6-10). 347 pp., 23 pls. ———_—__--__--—_-__-__-_—_--_—_- 10.00 Monographs of corals, turrids, spondyli, brevicones, Pseudorthoceratide and Fasciolaria, ri o, pa = a h f if y 3 2 pu ag \ = i ; ye % a ; Le * ine a i i) Pe Whee ae \ LW WAAN A u | { \ YN ga Y gem | 5 9 WN sem ¥ r [ wy AA aeeehaearar= a AAAAr AAR AAAANAAAANAEAE DR Ane BORRER Malai laaalalal ae AARRAARAA Anas aA RAARAAARAR arena AAAAAANa \ ala\ala\ AA ABAAAA AAAAAZ Allele aan ANAAAA Le perevrrer AAAAA AAAAAAAAAAAAAAS AAA AR A\AAAANAAAAAAAARACA NaN A | A AN AA alAlaialain!_|_i~!~|- a > AAA PY NaNa\a\a | AANA lan aaa Ia AM MAM Anas RANARP a aaAaiaaARAaneea rn casa AAA ON Ranaeena naaslaaaaen AAAAAAA Aaa e pARRAAAARAAAARAA AAAA alas PW \alala Bln Ain Yax\ PANY if AAAAIARIAF \AAAAA 2,AARIAINAAAAAAAAAAA AIA lA Besisnatannnctas AAAa a RAAAAAA a RARRAR I AAAA Ar anna AANAAa : | len AN . AAA DARGA PPPAAAAARARN Aa Aye \ -_ ee AAAAlAalh | | : RAAARBAAAAAAAA AR Aa AAA AA, rrrerermrrinetes oso AAAAAAAAAA AAAAAW pear | AAANaas We -AAAA, ale AA \ Ik J) \ | )\ /\ i | ) | \ WU VN ty WV HA 4] SN |) V q | q “= | LA | | } Il | | || j\ j | YM GUey¥ ey ‘WWW Saosin > 5) = TT