A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND A DISSERTATION Submitted to the Board of University Studies of The Johns Hopkins University in conformity with the requirements for the degree of Doctor of Philosophy BY DANIEL WEBSTER OHERN BALTIMORE THE JOHNS HOPKINS PRESS 1913 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND B Y DANIEL WEBSTER OHERN* ECHINODERMATA Subbranch C AS LS PELMATOZOA CRINOIDEA Order CAMERATA Family THYSANOCRINIDAE Genus THYSANOCRINUS Hall THYSANOOEINUS EUGENIUS n. sp. Plate XXXVI, Pigs. 3-5 2 Description.—Body medium in size, urn-shaped, truncate dorsally, the infrabasals and the lower parts of the basals forming the base of the body: wall of body almost straight below arm bases. Infrabasals 5, protruding beyond the periphery of column; basals 5, largest of the calyx, extremely convex; posterior basal larger than the rest and truncate above; the 4 lateral basals hexagonal, angular above; radials larger than costals, very convex and prominent heptagonal, angular below, truncate above; costals 2 x 5 , very convex, prominent, the first hexagonal, truncate above and below, the second pentagonal, truncate below, angular above, each side of 1 Manuscript submitted, June, 1907. All references to figures are to the Lower Devonian report of the Maryland Geological Survey in which these plates and text were published. 2 4 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND angle bearing a distichal; distichals 4 (?) x 10, the first larger than the rest which are transversely elongate, the last one often bearing a short, stout spine; arms 10, simple, biserial, composed of alternating cuneiform plates, and often bearing at fairly regular intervals a single spine or even a pair; pinnules not seen; intercostals 3—one in the first series, large hexagonal—two in the second series, hexagonal, smaller than the first and situated above it and between the second costals ; interdistichals 5 or more, small; interradial areas much depressed below the radial; anal interradial wider than the others, the first plate large, conspicuous, highly convex, resting on upper truncated edge of posterior basal and between the posterolateral radials, three plates in the second series, the middle one most prominent and resting directly upon the first series, other series present (indeterminate in specimens examined), the middle one always the more prominent by its convexity. Stem and tegumen unknown. Four individuals of this species are known to the writer. Of these two have spinose arms while the others seem to be without this feature. Nevertheless, unless further collections show this to be other than a specific variation, all must be regarded as one species. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland. Collection.—U. S. National Museum. Family MELANOCRINIDAE Genus TECHNOCRINUS Hall TECHNOORINUS SCULPTUS (Hall) Plate XXXVI, Figs. 10, 11 Mariacrinus (Technocrinus) sculptus Hall, 1859, Pal. N. Y., vol. iii, p. 143, pi. lxxxvi, figs. 13,14, 1861. Description.—"Body unknown. Base urn-shaped, gradually expanding above, abruptly expanded at the junction of the column: cavity for the insertion of the column large. Basal plates marked by strong sharp ridges, which diverge from the base to the upper margins, and unite upon the lines in the direction from the angles to the base of the plates." Hall, 1859. A CONTRIBUTION TO T H E L O W E R D E V O N I A N F A U N A S OF MARYLAND 5 This species is known only from the basal and first radial plates. T h e writer has not seen it. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland (fide H a l l ) . Collection.—American Museum of Natural History. TEOHNOCRINUS STRIATUS (Hall) Plate X X X V I , Figs. 8, 9 Mariacrinus (Technocrinus) striatus Hall, 1859, Pal. N. Y., vol. iii, p. 142, pi. lxxxvi, figs. 12 and 5-11, 1861. Description.—" Body unknown. Surface of plates marked by strong elevated striae, diverging from the center. long, small. Basal plates four, wider than First radial plates wider t h a n high. Column small." Hall, 1859. This species is known only from the basal and first radial plates. T h e writer has not seen it. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland (fide H a l l ) . Collection.—American Museum of Natural History. TEOHNOCRINUS ANDREWSI (Hall) Plate X X X V I I I , Fig. 2 Mariacrinus (Technocrinus) andrewsi Hall, 1859, Pal. N. Y.> vol. iii, p. 141, pi. lxxxvi, figs. 1-4, 1861. Technocrinus andrewsi Wachsmuth and Springer, 1897, Mem. Mus. Comp. Zool., No. 20, p. 306, pi. xxiv,fig.3. Description.—"A rather large species. Calyx to the arm bases hemi- spherical ; plates moderately convex, surrounded by sets of short marginal ridges passing inward, three to four to each side of the plate, and by small pits along the sutures; the center of the plates perfectly smooth. Basals wider than high. Eadials large, about as long as wide. First costals of the form of the radials, but considerably smaller; the second still smaller, narrower as well as shorter. Distichals one, axillary; supporting in the calyx two rather large palmars, followed by several cuneate, interlocking 6 A CONTRIBUTION TO T H E LOWEK DEVONIAN F A U N A S OF MARYLAND free plates, and these by two rows of subquadrangular pieces, united by a -sharply zigzag suture. Arms four to the ray, strong, flat, and of almost uniform width throughout. Pinnules contiguous. Interbrachials four or five : 1, 2, 1, 1, all comparatively large. Column round, large, t a p e r i n g ; •the joints rather long and slightly rounded exteriorly." Wachsmuth and -Springer, 1897. The writer has seen only the exterior mould of the lower part of the calyx of an individual of this species. I t is larger than HalFs type, but the plates that can be made out indicate t h a t it belongs to this species. T h e type came from Cumberland. Occurrence.—ORISKANY FORMATION, RIDGELY MEMBER. Cumberland (fide H a l l ) , Hancock. Collection.—Maryland Geological Survey. TEOHNOORINUS SPINULOSUS ( H a l l ) Plate X X X Y I 1 , Figs. 1, 2 Mariacrinus (Technocrinus) spinulosus Hall, 1859, Pal. N. Y., vol. iii, p. 140, pi. lxxxv, figs. 1-18, 1861. Technocrinus spinulosus Wachsmuth and Springer, 1897, Mem. Mus. Compt. Zool., No. 20, p. 305, pi. xxii,fig.3. Description.—" Calyx subglobose, the arm bases slightly contracting. Plates of the dorsal cup marked by a central spine or node, surrounded by smaller nodes, which vary in number among the plates. From the nodes two to four parallel ridges pass out to the sides, and these are continued upon adjoining plates. Near the arm bases the ridges gradually disappear, and the plates are marked only by a central spine. " Basals four, of medium size, forming a shallow basin with five sets of four ridges, each set communicating with those upon the radials. Eadials a n d costals nearly as wide as long, decreasing in size upwards; the second costal but half the size of the first. costal axillaries. Distichals one to each side of the The first palmar enclosed in the calyx. Arms twenty, stout, rounded; composed at their bases of cuneate pieces, which interlock farther up, and gradually become biserial. four. All other parts of the calyx unknown. Interbrachials apparently Column slightly pentag- A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 7 onal, each alternate joint provided with a node or short spine at the margin." Wachsmuth and Springer, 1897. Two imperfect specimens from the Oriskany comprise all that the writer has seen. The species is well marked and although the specimens are imperfect they are readily recognized as belonging to this species. Hair's type of this, as of all other species of this genus, was found near Cumberland. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland. Collection.—U. S. National Museum. TEOHNOORINUS (?) LEPIDUS n. sp. Plate XXXVII, Figs. 3-5; Plate XXXVIII, Fig. 1; Plate XXXIX Description.—Specimen large; calyx cup-shaped, depressed dorsalry, somewhat constricted at arm bases; plates generally highly convex, smooth. Basals not discernible in specimens observed; costals 2, second pentagonal and axial; distichals 2 x 10, the first usually hexagonal, the second pentagonal, hexagonal or heptagonal and axillary; palmars 2 x 2 0 , of irregular shape, each second one bearing an arm; intercostals 3, one in the first series, hexagonal, situated above and between the radials and between the first costals, two in the second series, situated between the second and costals, and above and between the second costals and the intervening intercostal of the first series; interdistichals several (7-10), of irregular size, shape and arrangement, all smaller than the corresponding distichals, some much smaller; interpalmars about 5, variable in size, arrangement and shape; interaxillaries 3, with supplementary smaller ones between the bases of the arms, the first interaxillary situated above and between the first costals, the second and third succeeding in order, each limited laterally by the palmars; between the bases of each pair of arms originating from the same costal is one or more small plates. Arms 20, biserial, extremely long and carrying multitudinous long pinnules, composed of several acutely spheroid alternating plates which are followed by regularly arranged alternating cuneiform plates. The lower plates of the calyx cannot be made out with certainty in any of the specimens at hand. The genus Technocrinus has been found so far only 8 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND in the Oriskany of Maryland. To it are referred provisionally certain large, pinnuliferous specimens from the region of Hancock. These are all in the form of natural moulds of the exterior. The interior casts are also found, but in the latter no arrangement of plates can be made out. The chief difference between the genus as defined by Wachsmuth and Springer and the specimens here referred to it, is in the distichals. When, however, it is remembered that the definition of the genus was based on two species, it is not surprising that such deviations should arise as other species are discovered. Mr. Springer, to whom the specimens under consideration were submitted, would refer them provisionally to this genus and the writer is of the opinion that further collections will show this to be correct. In one specimen the arms measure more than 22 cm. in length. Occurrence.—ORISKANY FORMATION, RIDGELY MEMBER. Cacapon Bridge; Pennsylvania Sand Quarry, 3 miles north of Berkeley Springs, West Virginia. Collection.—Maryland Geological Survey. Order FISTULATA Family CALCEOCRINIDAE Genus CALCEOCRINUS Hall CALCEOCRINUS MARYLANDICUS n. sp. Plate XL, Figs. 1-3 Description.—Body robust, laterally compressed. Basal disk of medium size, highly convex. Basals three, probably anchylosed, the suture lines barely discernible. Anterior basal U-shaped, truncate anteriorly. Lateral radials large, irregularly hexagonal, strongly convex and cinctured transversely. Anterior radials small as compared with the laterals, triangular, not in contact, apices ending near the bottom of a deep circular depression. The first brachial of the anterior ray large, wider than high, quadrangular, its lower angles in contact with the lateral radials and lower lateral brachials. The lower lateral brachials two, separated by depression, but evidently joined by syzygy, the suture lines, however, being discernible; the lower one much wider than high, quadrangular, separated from the radial below by a gaping suture; the upper one pentagonal, axial, sup- A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 9 porting on its horizontal edge a vertically ascending arm, and on its vertical side another axial plate which likewise bears an arm and a plate and so on until the number of lateral arms is eight; the axial plates form a marked ridge running along the bases of the arms. Lateral arms cylindrical, branching at about every fourth joint, which is nodose. Anterior arm much more robust than the lateral, cylindrical, its plates separated by deep incisions, not branching at least below the twelfth plate. Anal plates two, triangular, separated from the basal disk by a deep semicircular fossa, and truncate above. The upper surfaces jointly support a large anal tube which is larger at its base than the anterior arm, and decreases in size upward at least to the third plate where the tube disappears within the enfolding lateral arms. The posterior half of this anal tube is composed of large semicylindrical plates, but the anterior (interior) portion is invisible. Stem robust, composed evidently of plates uniform in size. The species is based on a specimen in the Museum of the Maryland Academy of Sciences collected by John Widgeon. This specimen seems, however, quite distinct from any heretofore described, and so far as the writer knows is the first occurrence of this genus in the Lower Devonian. The writer is informed that when found the stem was separated from the calyx so that only presumably are they the same individual. The upper portion of the arms has been broken off. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Quarry oppo- site Keyser, West Virginia. Collection.—Maryland Academy of Sciences. Family CYATHOCRINIDAE Genus HOMOCRINUS Hal! HOMOORINUS PROBOSOIDALIS H a l l Plate XL, Figs. 4, 5 Homocrinus proboscidalis Hall, 1859, Pal. N. Y., vol. iii, p. 138, pi. lxxxv, figs. 24, 25,1861. Description.—" Body subturbinate; base large. Basal plates wider than long, hexagonal. Eadial plates about as long as wide; brachial plates resting upon the truncated edges of the radial plates. 10 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND "Arms bifurcating upon the third brachial plate, and again upon the third and fifth or sixth plate above the first bifurcation: bifurcation apparently equal. Proboscis long, fusiform, very slender below, and acquiring its greatest diameter at about two-thirds the distance from base of body to summit of proboscis. Column unknown." Hall, 1859. The writer has not seen this species. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland (fide Hall). Collection.—American Museum of Natural History. HOMOCRINUS HARTLEYI n. sp. Plate XL, Fig. 6 Description.—Calyx small, broadly invert-conical, expansion regular from base of calyx to base of arms. Under basals 5, pentagonal, the lateral edges converging downward, lower edge coincident with the faces of the column. Basals large, largest of the calyx, convex, the four laterally situated are pentagonal, the posterior hexagonal and truncate above bearing the anal. Eadials alternating with the basals and resting above and between the four simple and pentagonal, the right posterior one being not easily made out, but apparently unlike others, upper edge of all notched but not profoundly. Anal large. Lower arm plates rather small, wider than high and profoundly convex, making the calyx deeply excavated between the arm bases. Column pentagonal, enlarged above. Arms and tegmen unknown. The species is based on one specimen in the collection of Mr. Hartley, but is quite clearly marked as a new species. It is larger than any other American form referred to this genus known to the writer except Homocrinus polyxo (Hall) from the Waldron Niagara. It has not, however, the interplate ridges of that species and the radially situated plates are not so deeply notched. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland. Collection.—Frank Hartley. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 11 Family AGASSIZOCRIN1DAE Genus EDRIOCRINUS Hall EDRIOCRINUS SACCULUS Hall Plate XL, Figs. 7-12 Edriocrinus sacculus Hall, 1859, Pal. N. Y., vol. iii, p. 143, pi. lxxxvii, figs. 1-22, 1861. Edriocrinus sacculus Weller, 1903, Geol. Survey N. J., Pal., vol. iii, p. 342, pi. xlv,figs.3-5. Description.—" Body more or less obconic or turbinate below and cylindrical above, varying in its proportions of length and breadth. Base varying in form from turbinate to hemispheric, solid, often obliquely truncate or indented below: upper margin marked by six subangularly concave depressions for the insertion of the radial and anal plates. Eadial plates large, longer than wide, inserted into the depressions in the margin of the base, gradually expanding towards the upper margin which is thickened externally, slightly concave for the reception of the plates of the arm. Arms broad at the base, composed of numerous very short transversely linear plates, of which ten or twelve or more occur below the first bifurcation: first bifurcation in the middle, and each side again bifurcating on the third or fourth plate above, with each division bifurcating once or twice beyond this; making eight or ten or more divisions at the extremities. Anal plates two, the lower large and of the same form as the radial plates; the second one small and short. Proboscis and summit unknown. Column, none; affixed to foreign bodies by the solid base."Hall, 1859. This is the most common crinoid of the Oriskany. Usually the armshave been broken off but in the fine collection of Mr. Hartley is a group of two, both of which are nearly perfect, and others preserving fragmentsof the arms. It was upon collections from Cumberland that Hall based his original description and account of the habits of the genus. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland, Knobly Mountain, near Cumberland; east side Nicholas Mountain and elsewhere in Maryland; Franklin, West Virginia. Collections.—Maryland Geological Survey, U. S. National Museum. 12 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND EDRIOCRINUS POCILLIFORMIS Hall Plate XL, Figs. 13-15 Edriocrinus pocilliformis Hall, 1859, Pal. N. Y., vol. iii, p. 121, pi. v,figs.8-12, 1861. Edriocrinus pocilliformis Meek and Worthen, 1868, Geol. Survey 111., vol. iii, p. 370, pLvii, figs. 5a, b. Edriocrinus pocilliformis Keyes, 1894, Missouri Geol. Survey, vol. iv, pt. i, p. 221, pi. xxx,fig.7. Edriocrinus pocilliformis Talbot, 1905, Amer. Jour. Sci., 4th ser., vol. xx, p. 23, pi. iv, figs. 1-6. Description.—" Base hemispheric or subturbinate, often less than a hemisphere, externally smooth or finely granulate: upper margin scolloped with five large and one smaller depression for the insertion of the radial and anal plates. Interior more or ]ess deeply concave, with depressions corresponding to those on the edge of the crip; the concavity not parallel to the exterior convexity. Eadial plates and arms unknown." Hall, 1859. " Infrabasals present but so fused that their number is uncertain. Height from one-half to two-thirds that of the cup as ordinarily found. Basals five, completely fused with each other and with the infrabasals or distinguished from the latter as a narrow protruding band. Suture lines sometimes apparent on the interior. Upper margin scolloped for the attachment of the radials and the anal plates. Height about half that of the infrabasals. Eadials five, often as high as the infrabasals and basals combined, and like them, fused to form a part of the cup. In most instances, however, the suture lines between the radials are plainly discernible. As a rule, the union between the radials and basals is not so strong as that of basals with infrabasals; and the cup is generally broken off at the top of the basals. Since in no specimens are brachials preserved, the union of brachials with radials must have been still weaker. Anal plates as high as the radials, but only half as wide. Eadials and anal gently convex, sloping in all directions from the center of the plate. Arms and ventral disc unknown. The attachment scar is visible on a number of specimens, and in some is a short distance up on the side of the cup, rather than on the bottom." Talbot, 1905. A CONTRIBUTION TO T H E LOWER DEVONIAN F A U N A S OF MARYLAND 13 Occurrence.—HELDERBERG FORMATION, N E W SCOTLAND MEMBER. Cumberland, Maryland; Cherry E u n , West Virginia. Collections.—Maryland Geological Survey, U . S. National Museum. VERMES a»ss ANNELIDA Genus CORNULITES Schlotheim CORNULITES CINGULATUS H a l l Plate X L , F i g . 16 Cornulites cingulatus Hall, 1888, Pal. N. Y., vol. vii, p. 20 (supplement to vol. v), pi. cxvi,fig.29. Cornulites cingulatus Clarke, 1900, Mem. N. Y. State Mus., vol, iii, No. 3, p. 27, pi. ii, figs. 35-38. Cornulites cingulatus Weller, 1903, N. J. Geol. Survey, Pal., vol. iii, p. 272, pi. xxxii,fig.3. Description.—" Tube very rlexuous, with regularly transverse but un- equally distant, sharply angled or evenly rounded annulations." Hall, 1888. " Shell having the form of a gradually tapering, more or less curved or flexuous, annulated cone. On the internal casts the annulations have the aspect of insheathed cones, the slope being abrupt below and gradual above. The width of the annulations is variable, but is usually a little less than 1 m m . ; they are somewhat irregular, there occasionally being one which does not entirely surround the tube." Weller, 1903. A single specimen from the Keyser member appears to belong to this species and is the only one which the writer has seen from the Lower Devonian of the State. Occurrence.—HELDERBERG Collection.—U. FORMATION, K E Y S E R MEMBER. S. National Museum. Pinto. 14 A CONTRIBUTION TO T H E LOWER DEVONIAN F A U N A S OF MARYLAND MOLLUSCA CLASS PELECYPODA order PRIONODESMACEA Section SCHIZODONTA Superfamily Family PTERINACEA PTER1NEIDAE Genus PTERINEA Goldfuss P T E R I N E A H A L L I Clarke Plate L X X V I I I , Figs. 11, 12 Avicula securiformis Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 290, pi. liii, figs. 11-14, 1861. Pterinea halli Clarke, 1903, Bull. N. Y. State Mus., No. 5, p. 495. Description.—" Shell subrhomb ovate, slightly oblique;, length and height varying from nearly equal, to the height one-fourth greater than the width, moderately convex in the middle and on the u m b o : anterior margin long, slightly concave above and curving to the base; posterior .margin below the sinus, somewhat abruptly curving into the broad rounded .basal m a r g i n : anterior wing small, trigonal, subacute, distinctly separated by a sinus from the body of the shell; posterior wings large, subacute *at the extremity, not strongly distinct from the body of the shell, extending as far as, or a little beyond, the margin of the shell; marginal sinuosity long and shallow. Surface marked by moderately strong radiating costae and strong elevated concentric striae." Hall, 1859. To this species is referred a fragment which has the sculpture and outline, as far as this latter can be made out, of Hall's species. I t is freely .admitted that such reference is a mere conjecture. Occurrence.—ORISKANY Collection.—George FORMATION, EIDGELY MEMBER. M. Eoeder. Cumberland. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OE MARYLAND 15 Genus LEPTODESMA Hall LEPTODESMA ? sp, Plate LXXV, Fig. 2 Description.—Three incomplete internal casts whose outlines and other characters cannot be made out with certainty are tentatively referred to this genus. The ligamental area is long and wide and longitudinally striated. Beneath the beaks are several fine transverse teeth, and posterior to the beak is a hinge margin evidently corresponding to a tooth in the shell. The anterior extremity seems to be neither nasute nor auriculate. The anterior muscular impression is small and deep. Tn the cast the position of pallial line is marked anteriorly by a sharp ridge. A part of an exterior from the same rock mass shows the surface of the shell to be marked only by irregular concentric growth lines. Length 5.5 cm.; height 4.5 cm. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Eock Enon Springs, Virginia. Collection.—U. S. National Museum. Family AMBONYCHIIDAE Genus MYT1LARCA Hall MYTILARCA MARYLANDICA n. sp. Plate LXXV, Figs. 3, 4 Description.—Shell inequivalve, slightly inequilateral, convex, depressed, subtrigonal in outline; anterior side concave beneath beaks, thence broadly rounded, antero-ventral margin truncate, posterior extremity sharply rounded to subangular. Beaks prominent, approximate. Left valve convex, the maximum inflation being in the umbonal region; right valve less convex, much depressed toward ventral side. Muscular markings and exterior ornamentation not seen. Length 20 mm.; height 24 mm. The specimen figured is a cast of the interior, the only individual seen. The truncation of the postero-ventral side seems due, in part at least, to poor preservation, and the irregularity in the outline of the anterior 16 A CONTRIBUTION TO T H E L O W E R D E V O N I A N F A U N A S OP MARYLAND margin is caused by mechanical displacement of a portion of the cast. The precise horizon from which this species comes is unknown. Occurrence.—HELDERBERG Collection.—George FORMATION. Cumberland. M. Eoeder. MYTILARCA CORDIFORMIS ( H a l l ) ? Plate L X X V , Figs. 5, 6 Megambonia cordiformis Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 278, pi. 1, figs. 6a, b, 1861. Description.—" Shell cordiform, extremely gibbous from the base up- wards to the umbones, which are elevated and incurved, not compressed at the basal or lateral m a r g i n s ; anterior cardinal extremity slightly auriculate, the prominence covering the muscular impression small. marked by concentric lamellose striae." Surface Hall, 1859. Two specimens in the collection of Mr. George M. Eoeder from an unknown horizon appear to belong to this species. valves are present. I n both specimens both The individuals are smaller than Hair's figure but in other respects are very similar. Occurrence.—HELDERBERG Collection.—George FORMATION. Cumberland. M. Eoeder. Subgenus PLETHOMYTILUS Hall MYTILARCA ( P L E T H O M Y T I L U S ) ROWEI n. sp. Plate L X X V , F i g . 7 Description.—Shell equivalve; not strongly inequilateral; gibbous; broadly ovate; umbonal slope expanding somewhat rapidly from umbones to about one-fourth or one-third the length of the shell, then arching broadly and gently to the postero-basal margin, sloping gradually to the postero-dorsal and suddenly to the antero-basal m a r g i n ; postero-dorsal margin almost rectilinear to about three-fourths the length of the shell, posterior extremity subcircularly rounded, basal margin broadly rounded, anterior margin rectilinear ( ? ) to beak; beaks prominent, approximate. Surface of interior smooth, interrupted irregularly by broad, often discontinuous, concentric furrows. Hinge-line not seen. Greatest length 73 m m . ; greatest width 55 mm. A CONTRIBUTION TO T H E L O W E R D E V O N I A N F A U N A S OF MARYLAND 17 All the specimens seen are casts of the interior, but there is little doubt as to the generic affinities. The naming of the species is a humble compliment to the late D r . E . B . Eowe. Occurrence.—-ORISKANY Collection.—Maryland FORMATION, EIDGELY M E M B E R . Hancock. Geological Survey. Family PINNID^ Genus PALEOPINNA Hall P A L E O P I N N A LATA n. sp. Plate L X X V I , F i g . 1 Description.—Shell large, very oblique, axis and hinge-line making an angle of about 2 3 ° ; greatest length to greatest height as about 3 to 4 ; anterior margin truncate and emarginate, ventral margin broadly and regularly curving, posterior margin more rapidly rounding and recurving to meet the hinge-line; left valve gibbous in middle and anteriorly, depressed posteriorly and dorso-posteriorly; right valve not known. Umbo wide, beak probably extending to posterior limit of body; a narrow ridge extending from beak ( ? ) along hinge-line to posterior end of dorsal margin. Interior marked by broad obsolete growth lines. Exterior un- known. Length 8.75 c m . ; height 6 cm. The description is from the cast of the interior of the left valve of a single specimen. I t has all the marks of this genus and is readily separable from the other species of this genus by its great breadth. A part of the postero-dorsal extremity and of the beak is broken off. Occurrence.—ORISKANY Collection.—Maryland FORMATION, EIDGELY M E M B E R . Hancock. Geological Survey. Family PTERIIDAE Genus ACTINOPTERIA Hall ACTINOPTERIA COMMUNIS ( H a l l ) Plate L X X Y I , Figs. 2-4 Avicula communis Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 286, pi. lii, figs. 1-7; pi. liii, figs. 1, 4, 6, 1861. Actinopteria communis Clarke, 1900, Mem. N. Y. State Mus., No. 3, vol. iii, p. 34, pi. iv, figs. 1, 2. Actinopteria communis Weller, 1903, Pal. N. J., vol. iii, p. 292, pi. xxxi,fig.21. 18 A CONTRIBUTION" TO THE LOWER DEVONIAN, FAUNAS OE MARYLAND Description.—" Shell obliquely ovate; the left valve,gently convex in the middle, an,d, becoming gibbons towards,.the, beak,; which in the young shell is narrow and projecting above the hinge-line; right valve flat or gently, concave in the middle, and below, and becoming slightly convex on the umbo; anterior side gently: curving to the base which is broadly rounded, the curvature of the posterior side being more abrupt: anterior wing small, trigonal, obtuse at its extremity, strongly denned from the body of the shell: posterior wing three times as long as the anterior wing, obtusely or subacutely pointed, extending more or less beyond the margin of the shell, concave on the outer or lateral margin, its junction with the body of the shell not strongly defined. " Surface of the left valve marked by slender, sharply defined, rounded radii, the principal of which are distant from two to four or five times their width, and the spaces occupied by one, two or three finer interstitial radiating striae (these radii are but faintly, and sometimes not at all perceptible on the posterior wing, except along its upper margin, while they are not seen on the anterior wing) ; concentrically marked by fine lamellose striae, which, in the more perfectly preserved surfaces, are elevated and subimbricating : these striae are usually conspicuous on both the anterior and posterior wings. Surface of the right valve marked by broader and scarcely elevated radii and less defined concentric striae." Hall, 1859. This species is rare in the Lower Devonian of Maryland. That it is subject to wide variations is apparent from Hair's figures, and it may be questioned whether that author has figured but one species. However, no further light can be obtained from the few Maryland forms. Occurrence.—HELDERBERG FORMATION, KEYSER MEMBER. land, Tonoloway ? Cumber- Dawson, Corriganville. ISTEW Dawson, Devil's Backbone. Horizon unknown. Miller's Spring, Cedar Cliff, West Virginia. ORISKANY FORMATION. Locality not known. Collections.—-Maryland Geological Survey, U. S. National Museum. COEYMANS MEMBER. SCOTLAND MEMBER. ACTINOPTERIA OOMMUNIS (Hall) var. Description.—A few imperfect specimens from the Oriskany resemble in a general way A. communis (Hall). The left valve shows fine, alter- A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 19 nating striae, crossed by finer, concentric striae, giving to the whole a cancellated effect which is somewhat more marked on the posterior wing. These specimens are very like those figured by J. M. Clarke under this species and may be wholly identical with them. It seems best, however, to designate them as a variety, but their fragmentary condition will not permit definition. Occurrence.—ORISKANY FORMATION, KIDGELY MEMBER. Winchester Eoad and Miller's Spring near Cumberland. Collection.—Maryland Geological Survey. ACTINOPTERIA TEXTILIS (Hall) Plate LXXYI, Fig. 5 Avicula textilis Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 288, pi. Hi, figs. 9, 10 ?; pi. liii, figs. 2, 3, 5, 7, 10, 1861. Actinopteria textilis Weller, 1903, Pal. N. J., vol. iii, p. 332, pi. xliii, figs. 13, 14. Description.—" Body of the shell obliquely subovate; length about once and a half the height, becoming regularly convex from the base, gibbous in the middle, and gently depressed along the line of junction with the posterior wing; ventral margin very regularly and broadly curved ; hingeline greatly extended: posterior wing long, nearly three times its greatest width, the extremity extending beyond the margin of the shell, the margin moderately sinuate. Surface marked by regular strong radiating ribs, which, at the base, are distant from each other three times their width; the intermediate space marked by a central finer ray, and, on each side between it and the larger costa?, are one or two still finer rays, which are scarcely perceptible to the naked eye: these are crossed by concentric ridges, giving a cancellated surface and a slightly nodose character to the larger costse. The wing is marked by strong radiating and concentric striae, which are of neariy equal size, and slightly nodose at their junction." Hall, 1859. Length 4.7 cm.; height 4.5 cm. Occurrence.—HELDERBERG FORMATION, N E W SCOTLAND MEMBER. Cumberland, Dawson. Collections.—Maryland Geological Survey, George M. Eoeder. 20 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND ACTINOPTERIA TEXTILIS VAR. ARENARIA ( H a l l ) Plate LXXVII Avicula textilis var. arenaria Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 465, pi. cix, figs. 1, 2; pi. ex, fig. 2, 1861. Avicula textilis var. arenaria Weller, 1903, Pal. N. J., vol. iii, p. 360, pi. 1, fig. 1. Description.—" Shell large, obliquely subovate; the proportions of length and height variable. Left valve becoming moderately and regularly convex from the base, the greatest convexity being about the first third below the hinge-line. Posterior wing large, extending along the margin of the body of the shell halfway from beak to base. Anterior wing small, triangular, wrinkled. The right valve is slightly concave, smaller than the other, faintly marked by the radiating ribs, which sometimes are scarcely seen. Surface marked by strong radiating ribs sometimes regularly dichotomizing and subequal, and in other specimens quite unequal, showing a few stronger ribs, with several finer ones between, and these are crossed by strongly elevated imbricating lamellse." Hall, 1859. Several specimens from the Oriskany of the state are referred to this variety. The close resemblance between A. communis, the typical A. textilis and the varietal form, casts doubt upon the identification of the forms as they occur in Maryland. Occurrence.—ORISKANY FORMATION, KIDGELY MEMBER. Warren Point, Pennsylvania; west side of Queen's Point opposite Keyser, Miller's Spring, West Virginia. Collections.—Maryland Geological Survey, U. S. National Museum. ACTINOPTERIA VIRGINIOA 11. s p . Plate LXXVIII, Pigs. 1, 2 Description.—Body of the shell obliquely ovate, gibbous, maximum inflation about one-third the distance from the beak to the base. From this point the shell arches rapidly to the beak and gently to base; contracts rapidly on either side of the umbo near the beak and less so as the distance from beak increases; beaks not prominent; posterior wing not sharply A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 21 separated from body, convex; anterior wing not seen; anterior extremity suddenly rounded, basal margin broadly and regularly arcuate, posterior extremity broadly rounded; surface of body covered by low, arched, radiating ribs, between which, toward the margin, finer ones are interposed ; posterior wing unornamented. Hinge-line straight. The description is from a cast of the interior of a left valve which is not quite complete. The species bears some resemblance to A. recticosta Hall, but the general outline and the character of the radiating ribs at once separate it. Another imperfect cast in the Maryland Geological Survey collection is doubtfully referred to this species. I t is, however, more oblique, the large ribs are smaller and the small ones larger in proportion than the specimen described. It is not improbable that further collections will separate this as another species, the material now in hand not warranting such procedure. Length 6.5 cm.; height 4.5 cm. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Near Fountain, four miles southwest of Keyser, West Virginia; Hancock, Maryland. Collections.—Maryland Geological Survey, TJ. S. National Museum. Genus AVICULA Klein AVICULA RECTICOSTA H a l l ? Plate LXXYI, Fig. 7 Avicula recticosta Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 466, pi. cix, fig. 3, 1861. Description.—" Shell slightly oblique, subrhomboidal: hinge-line greater than the greatest width of the shell below; width equal to about once and a third the height, very moderately convex. Posterior wing large, extending nearly as far backwards as the posterior margin of the shell. Anterior wing smaller, triangular, slightly concave on the outside. Surface marked by strong dichotomizing subequal ribs, which proceed principally in pairs from the umbo to the margin of the shell. Posterior wing with fine radiating ribs and close concentric laminae; the anterior wing being marked only by the concentric striae." Hall, 1859. 22 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND To this species is referred, doubtfully, a single fragmentary individual. Occurrence,—ORISKANY FORMATION. Locality unknown. Collection.—Eobert H. Gordon. Section ISODONTA Family PECTINIDAE Genus AVICULOPECTEN McCoy AviCULOPECTEN ( ? ) , CUMRERLANDENSIS n . s p . Plate LXXVIII, Fig. 3 Description.—Shell subcircular, length and height about equal; slightly oblique; left Valve gibbous, the maximum inflation being anterior to the center of the shell which curves thence steeply to the anterior, and much less so to the basal and posterior margins; anterior margins broadly sinuate at junction of anterior wing and the body of the shell, thence slightly convex outward to anterior extremity, thence the margin is almost semicircular to the posterior wing which is widely sinuate, the maximum excavation being at about two-thirds the distance from the extremity of the wing to the body of the shell; anterior wing small, concave; posterior winglarge, convex, the extremity being nearly a right angle and on line with the posterior extremity of the body; hinge-line straight, equal to greatest width of shell. Surface of body ornamented with coarse, radiating ribs which are subequal on the anterior, and alternating on the central and posterior parts; the radiating ribs are crossed by finer concentric striae and irregular growth lines; surface of posterior wing ornamented with alternating ribs which are somewhat finer than those of the body and crossed by concentric striae, the two sets of markings giving a cancellated effect. Eight valve and interior not seen. The description is from a single left valve, which is figured. The label has been lost but the specimen is no doubt from the Helderberg, as is shown by other fossils in the rock mass. Length about 5 cm.; height 5.2 cm. Occurrence.—HELDERBERG FORMATION. Locality unknown. Collection.—Maryland Geological Survey. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OE MARYLAND 23 Section DYSOOONTA Superfamily M Y T I L A C E A Family MODIOLOPSIDAE Genus MEGAMBONIA Hall MEGAMBONIA LAMELLOSA Hall Plate LXXVIII, Fig. 5 Megambonia lamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii,p. 467, pi. cix, figs, 5, 6, 1861. Description.—" Shell obliquely ovpid> :very gibbons in the middle and towards the umbo; the body of the shell rather abruptly narrowed above the middle. Anterior wing short, rounded, very convex, separated from the body of the shell by a'b'rbad rounded depression, leaving a sinus in the margin. Posterior wing broad triangular, extending more than two-thirds the entire length of the posterior slope; its jimction with the body of the shell marked by a depression. Surface marked by concentric-damellose striae, which, on some parts of the specimens, are very prominent. Faint remains of radiating striae are sometimes perceptible on the casts." Hall, 1859. It has been found only in the form of casts, but it is not uncommon in the Oriskany of 'Maryland. Length about 3.5 cm.; height 2.5 cm. Occurrence.—ORISKANY FORMATION, BXDGELY MEMBER. Queen's Point opposite Keyser, Miller's Spring, and Knobly Mountain, West Virginia; near Cumberland, Hancock, Maryland. Collections.—Maryland Geological Survey, IT. S. National Museum. order TELODESMACEA Superfamily CYPRICARDIACEA Family PLBUROPHORIDAE Genus CYPRICARDINIA Hall SUBLAMELLOSA Hall CYPEICARDINIA ' Plate LXXVIII, Fig.'8 Cypricardinia sublamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 267, pi. 1,fig.1, 1861. 24 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND Description.—"Shell transversely elongated; anterior extremity contracted; umbones very depressed; posterior slope convex, without a defined ridge; extremity somewhat acutely rounded. Surface marked by rounded concentric striae or ridges, which are more prominent on the posterior half of the shell." Hall, 1859. Occurrence.—HELDERBERG FORMATION, NEW SCOTLAND MEMBER. Devil's Backbone. Collection.—Maryland Geological Survey. INCERTAE SAEDES Genus ILIONIA Billings ILIONIA SINUATA (Hall) Plate LXXVIII, Figs. 9, 10 Anatina ? sinuata Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 265, pi. xlix, figs. Za-d, 1861. Description.—" Shell thin, equivalve, compressed, inequilateral, subrhomboid, with the posterior side much wider than the anterior; posterior ? rounded, much compressed near the extremity, with a distinct shallow groove extending from near the beak obliquely to the postero-basal margin, and a second broad groove extending from the hinge-line, immediately behind the beak, vertically to the base of the shell, each one producing a slight sinuosity in the margin of the shell: umbones vertical, or not perceptibly inclined to either side of the shell; anterior cardinal slope nearly flat, compressed and subalate. Surface concentrically marked with fine subimbricating striae, which are undulated in passing over the depressed lines on the anterior side of the shell." Hall, 1859. Several specimens from an unknown horizon in the Lower Helderberg are referred to this species but not without doubt. All are in the form of interior casts and none have the outline sufficiently complete to permit restoration. Nevertheless, from the entire collection enough can be gathered to show a very close resemblance to HalFs figures and description. The Maryland forms are in general much larger than those figured by Hall. , ; • • : • A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 25 Occurrence.—HELDERBERG FORMATION. East of Martin Mountain, Allegany County, on road leading to Eush. Collection.—-Maryland Geological Survey. GASTROPODA subclass STREPTONEURA CLASS order ASPIDOBRANCHIA Suborder RHIPIDOGLOSSA Family PLEUROTOMARIDAE Genus PLEUROTOMARIA Defrance PLEUROTOMARIA LABROSA Hall Plate LXXX, Fig. 1 Pleurotomaria labrosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 339, pi. lxvi, figs. 1-5; pi. lvii, figs. 6a, b, 1861. Description.—" Shell rhomboid ovate. Spire little elevated above the body of the shell: volutions three or four; the upper ones small and moderately increasing, the last one ventricose, much expanded on the outer side, and subangular: aperture broadly ovate; the columellar lip extremely thickened, the callosity extending to the outer lip. Surface marked by prominent spiral ridges with wider furrows between, and, on the upper part of the volution, by a broader band or groove, which is margined by caringe: lines of growth marked by strong elevated lamellose strise, which are undulated in passing over the spiral ridges; those marking the broader spiral band are less strongly elevated, and make a single retral curve, indicating the marginal sinus." Hall, 1859. Occurrence.—HELDERBERG FORMATION, Cumberland. Collection.—George M. Eoeder. NEW SCOTLAND MEMBER. 26 A CONTRIBUTION TO THE LOWER .DEVONIAN FAUNAS OF MARYLAND Family BELLEROPHONTIDAE Genus BELLEROPHON Montfotrt BELLEROPHON CF. AURICULATUS Hajl Plate LXXIX, Pigs. 1, 2 Bellerophon auriculatus Hall, 1852, Nat. Hist. N. Y., Pal., vol. ii, p. 334, pi. Ixxvi, figs, la, b. Description.—" Convolute; volutions somewhat flattened from the dorsal side; last volution rapidly enlarging; aperture expanded, curving outwards and nearly r.enexed at the?:lateral angles. The remains of a carina, with arched striae diverging therefrom, are visible upon the dorsal die." Hall, 1852. • Several specimens, in the collection of Mr. Eoeder are tentatively referred to in this species. In general aspect they resemble Hall's figures very closely, but are much smaller. Precise horizon unknown. Diameter of shell 1.5 cm.; of aperture 1..5 ;cm. Occurrence.—HELDERBERG FORMATION. Cumberland. Collection.—George M. Boeder. Genus CYRTOLITES Conrad CYRTOLITES EXPANSUS Hall Plate LXXIX, Eigs. 5, 6 Cyrtolites ? expansus Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 479, pi. cxiv, figs. 4, 5, 1861. Cyrtolites expansus Clarke, 1900, Mem. N, Y. State Mus., vol. iii; No. 3, p. 28, pi. iii,figs.20-23. Description.—" Shell obliquely depressed. conical; the apex incurved, but making scarcely or no more than, a single volution, very rapidly expanding from the apex; the body ventricose; subcarinate on the dorsum: aperture nearly circular. Surface of cast marked by faint transverse ridges and finer longitudinal striae." Hall, 1859. ", . . . characterized: 1 by the sharply concentric lamellae of the surface ; 2 by the broadly expanded aperture; 3 by the well-defined median ridge on the earlier parts of the shell, on which: the striae have a pronounced retral bend, the ridge being obsolete at the margin." Clarke, 1900. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 2 7 In the collection of Mr. George M. Eoeder is to be found the only entire specimen which the writer has seen from Maryland. The agreement with Hall's description is very exact. Diameter of shell 6.2 cm.; of aperture 4.75 cm. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Williams Eoad near Cumberland. Collections.—Maryland Geological Survey, George M. Eoeder. order CTENOBRANCHIATA Suborder P L A T Y P O D A Superfamily GYMNOGLOSSA Family PYRAMIDELLIDAE Genus LOXONEMA Phillips LOXONEMA FITCHI H a l l Plate LXXIX, Fig. 7 Loxonema fitchi Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 296, pi. liv, figs 9, 11a, &, 1861. Description.—" Shell subfusiform, very gradually attenuate: volutions seven or eight. Surface unknown." Hall, 1859. Volutions broadly arched, wide, suture deeply impressed. A few imperfect casts which may be from the Helderberg agree well with Hair's description and figures. In the state of their preservation no further features can be observed. Occurrence.—HELDERBERG FORMATION. Tonoloway. Collection.—Maryland Geological Survey. Superfamily T A E N I O G L O S S A Family LITTORINIDAE Genus HOLOPEA Hall HOLOPEA sp. Description.—A large specimen, coming from an unknown horizon in the Lower Devonian, was studied, which evidently belongs to this genus, but whose condition of preservation does not permit identification or de- 28 A CONTRIBUTION TO T H E L O W E R D E V O N I A N F A U N A S OF MARYLAND scription. I n general aspect it is not unlike H. antiqua, but any attempt at further identification is hazardous till further collections are made. Occurrence.—HELDERBERG Collection.—George FORMATION. Cumberland. M. Boeder. H O L O P E A sp. Plate L X X I X , F i g . 9 Description.—The large specimen figured represents a form which is referred with doubt to this genus. A part of the body whorl has been broken off, all surface features have been obliterated and the whole shell laterally compressed, thus making identification impossible. T h e writer is very much in doubt as to the horizon to which this specimen belongs. Length 4 c m . ; diameter 3.2 cm. Occurrence.—HELDERBERG Collection.—George FORMATION. Cumberland. M. Boeder. Genus ORTHONYCHIA Hall ORTHONYCHIA TORTUOSA ( H a l l ) Plate L X X I X , Figs. 10-12 Platyceras tortuosum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 472, pi. cxiii, figs. 1-5, 1861. Orthonychia tortuosa Clarke, 1900, Mem. N. Y. State Mus., vol. iii, No. 3, p. 30. Platyceras tortuosum Weller, 1903, Geol. Survey N. J., Pal., vol. iii, p. 362, pi. xlix, figs. 13-17. Description.—" Shell spirally ascending, making a little more than one free volution: volutions widely separated, very gradually increasing in size towards the aperture, which is scarcely expanded; peristome very oblique. A broad spiral fold sometimes marks the inner side of the spire." Hall, 1859. Surface marked by irregular, undulating lamellae, the undulations evidently marking the position of sinuses. As high as three distinct folds are observable on the interior of the spire. Length 5 cm.; maximum diameter 3 cm. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 29 Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Devil's Back- bone, Hancock, Knobly Mountain near Cumberland. Collections.—Maryland Geological Survey, Maryland Academy of Sciences. Genus PLATYCERAS Conrad PLATYCERAS NODOSUM Conrad Plate LXXIX, Pigs. 13,14 Platyceras nodosum Conrad, 1841, Ann. Rept. Pal. N. Y., p. 56. Platyceras nodosum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 473, pi. cxv, figs. 1-6; pi. cxvi, figs. 1-4, 1861. Platyceras nodosum Clarke, 1900, Mem. N. Y. State Mus., No. 3, vol. iii, p. 31. Description.—" Subfalcate, with numerous thick obtuse nodes. This is a cast in the sandstone, and the shell was probably covered with spines. Length two inches." Conrad, 1841. " Shell obliquely subovate: volutions contiguous, about two or three, very rapidly expanding from the apex; summit of the spire on a plane with, or a little above, the outer volution; aperture round. Surface marked by round obtuse nodes and strong interrupted or tortuous lamellose stride." Hall, 1859. This species in its typical form with well-marked nodes, has been found only in the Oriskany formation at Warren Point. However, several localities furnish specimens with irregular swellings. Such specimens are doubtfully referred to this species. Diameter of shell 6.5 cm.; of aperture 5 cm. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland, east side of Nicholas Mountain, Maryland; Warren Point, Pennsylvania. Collection.—Maryland Geological Survey. PLATYCERAS GEBHARDI Conrad Plate LXXX, Figs. 2-9 Platyceras gebhardi Conrad, 1840, Ann. Rept N. Y. Geol. Survey, p. 206. Platyceras gebhardi Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 312, pi. lvi, figs. 5a, b, 6, 7, 9; pi. lv, figs. 6a, b; p. 474, pi. cxvii, figs. 1-10, 1861. Platyceras cf. gebhardi Clarke, 1900, Mem. N. Y. State Mus., No. 3, vol. iii, p. 30, pi. iii,fig.29. Strophostylus gebhardi Weller, 1903, Geol. Survey N. J., Pal., vol. iii, p. 318, pi. xxxix, figs. 1-3. 30 A OONTKIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND Description.—" Shell obliquely subovate or subglobose, somewhat gradually expanding, and becoming ventricose in the last volution. Spire composed of about four volutions, which are contiguous except the last one near the aperture, the apex being nearly in the plane of the outer volution : aperture expanded, campanulate, and sometimes with the lip reflexed. Surface marked by fine transverse undulating stride, which are sometimes distinctly bent backwards along a line near the dorso-lateral curvature of the shell, or nearer to the middle of the summit, and rarely slightly carinated along this line. In a few specimens, distinct revolving striae are seen cancellating the transverse striae." Hall, 1859. This is the most common species of gastropod in the Lower Devonian of the state. It varies widely in size and in the character of the apex which is sometimes above and sometimes below the plane of the body whorl. See further remarks under var. ventricosum. Occurrence.—ORISKANY FORMATION, EIDGE,LY MEMBER. Knobly Mountain, Monster Bock, opposite Keyser, West Virginia; Nicholas Mountain, Hancock, Cumberland, Flintstone, Maryland; Warren Point, Pennsylvania. HELDERBERG FORMATION, NEW SCOTLAND MEMBER. Cumberland, Maryland; Cherry Bun, Miller's Spring, West Virginia; Warren Point, Pennsylvania. Collections.—Maryland Geological Survey, IT. S. National Museum. PLATYCERAS GEBHARDI VAR. VENTRICOSUM Conrad Plate LXXXI Platyceras ventricosum Conrad, 1840, Ann. Rept. Pal. N. Y., p. 206. Platyceras ventricosum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 311, pi. lvi, figs. 1-4, 8; pi. lvii, fig. 4; p. 475, pi. cxviii, figs. 3-9, 1861. Platyceras ventricosum Meek and W o r t h e n , 1868, Geol. Survey 111., vol. iii, p. 441, pi. ii, figs. 4a, Z . > Platyceras ventricosum Nicholson, 1874, Rept. upon t h e Pal. of t h e Province of Ontario, p. 115, pi. ii, figs. 1, l a . Platyceras ventricosum Nettleroth, 1889, K e n t u c k y Fossil Shells, p. 168, pi. xxv, fig. 10. Description.—" Shell ventricose; aperture very large and campanulate; volutions three, contiguous, depressed below the upper margin of the whorl." Conrad, 1845. A CONTRIBUTION TO* THE LOWER DEVONIAN FAUNAS OF MARYLAND 31 " The shell is obliquely ovate-spreading rapidly from the apex, and becoming extremely ventricose below; aperture campanulatc; the lip in contact with the spire, and sometimes strongly refiexed. Surface marked by fine transverse or concentric lamellose strise, which are somewhat undulated and rarely finely cancellated by faint, revolving striae. Volutions contiguous throughout, or the last one free; peristome continuous or interrupted, free or in contact with the body volutions, sometimes abruptly expanded at the margin." Hall, 1859. This variety is made a species by Hall. In the specimens from Maryland the difference between the typical Platyceras gebhardi and the variety is so slight that it cannot be regarded as of specific value. Indeed, it is extremely doubtful if even a varietal difference exists and the writer is of the opinion that further collections will show the complete identity of HalFs two species. Occurrence.—ORISKANY FORMATION, RIDGELY MEMBER. Cumberland, east side Nicholas Mountain, Hancock. Collection.—Maryland Geological Survey. PLATYCERAS { MAGNiifictrM Hall Plate LXXXII, Figs, 1-6 Platyceras magniflcum Hall, 1859, Nat. Hist. N. Y., Pal., voll'iii, p. 476, pi. cxix, figs. 1-6,1861. Description.—" Shell obliquely subovate. Spire depressed below the plane of the outer volution: volutions two or three, very rapidly expanding and becoming extremely ventricose below, usually free or with the first one contiguous; aperture expanded, subcircular, campanulate, and often with the margin refiexed, particularly on the left side. Surface marked by distinct transverse lamellose undulating strise." Hall, 1859. Occurrence.—ORISKANY FORMATION, RIDGELY MEMBER. Cumberland, east side Mcholas Mountain, Cash Valley, Maryland; Warren Point, Pennsylvania; Miller's Spring, West Virginia. Collections.—Maryland Geological Survey, TJ. S. National Museum. 32 A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND PLATYCERAS SUBEALCATUM n. sp. Plate LXXXII, Figs. 7, 8; Plate LXXXIII, Figs. 1-3 Description,—Shell subfalcate; whorls (of casts) one; very rapidly expanding from beak to aperture, becoming extremely ventricose, and suddenly contracting at the aperture; surface marked by low, distant, parallel, longitudinal undulations, sometimes becomes slightly nodulose; aperture subcircular; outer surface and peristome not seen. Found only as internal casts. This species in the character of the undulations, bears some resemblance to P. platystomum of the Lower Helderberg of New York; but its shape and the constriction of the aperture show it to be distinct from other species of the genus. Diameter of shell 4.5 cm. to 8 cm.; of aperture 3.2 cm. to 6 cm. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Hancock. Collection.—Maryland Geological Survey. PLATYCERAS PATULUM Hall Plate LXXXIII, Fig. 4 Platyceras reflexum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 477, pi. cxx, fig. 3, 1861. Description.—" Shell subhemispheric. Spire forming about three volutions, which are usually contiguous, sometimes free, very rapidly expanding, the last one extremely ventricose and assuming a hemispheric form; apex much below the plane of the last volution. Aperture nearly circular; peristome much expanded upon the side of the body volution, and thickening below in the form of a columellar lip. Surface transversely striated." Hall, 1859. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. Cumberland. Collection.—Frank Hartley. PLATYCERAS REFLEXUM Hall Plate LXXXIII, Figs. 5, 6; Plate LXXXIV, Figs. 1, 2 Platyceras reflexum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 477, pi. cxx, figs. 1-7, 1861. A CONTRIBUTION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND 33 Description.—" Shell spiral, obliquely or arcuately subcorneal, spirally ascending; the apex consisting of one or two free, but closely approximating volutions; the body volution .diverging, and spreading somewhat rapidly towards the aperture: aperture broad, the peristome often sinuous and sometimes abruptly expanded: volutions round or subangular, and rarely distinctly angular, with the aperture subquadrate. Surface transversely striate; the striae sometimes bent abruptly backwards on the surface, indicating the existence of a marginal notch at some period of growth." Hall, 3859. Occurrence.—HELDERBERG FORMATION, NEW SCOTLAND MEMBER. Corriganville. ORISKANY FORMATION, EIDGELY MEMBER. Cumberland, east side Nicholas Mountain. Collections.—Maryland Geological Survey, U. S. National Museum. PLATYCERAS ? CALLOSUM Hall Plate LXXXIV, Figs. 3,4 Platyceras ? (Platyostoma ?) callosum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 478, pi. exx, figs. 8a, D, 1861. Description.—" Shell obliquely ovoid, ventricose. Spire consisting of about three volutions; the apex minute, and the first two volutions nearly in the same plane; the last volution expanding greatly below. Aperture suborbicular: peristome continuous, thickened and coalescing with the body volution at its lower side; the umbilical cavity closed by a callosity; the shell, approaching the aperture, becoming lamellose* the lamellae elevated and imbricating. Surface marked by undulating transverse striae and obscure revolving striae, with obsolete parallel undulations. The lines of growth are strongly arched forward on the middle of the back of the shell." Hall, 1859. Occurrence.—ORISKANY FORMATION, EIDGELY MEMBER. (fide Hall). Collection.—American Museum of Natural History. Cumberland 3 4 4 COMPETITION TO THE LOWER DEVONIAN FAUNAS OF MARYLAND : , ; . ;. ••:.,:.,..;, — PlATYCERAS SII^UATUM H a l l ? Plate L X X X I V , Figs. 5, 6 Pldtyderassiniidtum EtsLll, 1859, Nat. Ilist. ft. Y., Pal., vol. iii, p. 314, pi. lv, figs. 5, 7; pLlvii,• Description.—" Shell depressed, somewhstt obliquely ovoid:1 volutions about three, ( contiguous, the" last one becoming'very ventricose, a little flattened on the upper1 side, and expanded laterally to the axis of the spire: aperture broad, campanulate; margin deeply Sinuate. Surface marked by fine concentric or transverse lamellose striae, and stronger wrinkles or folds1. The stria} are abruptly bent backwards oil the Upper dorsal side, and a deep sinus marks the labrum: the lower side of the aperture is likewise deeply sinuate." Hall, 1859. Occurrence:—ORISKANY FORMATION', BTDGELY MEMBER. East side Nicholas Mountain. Collection.-—Maryland Geological Survey. PLATYCERAS TRltOBATUM H a l l ? • Plate L X X X W , Pigs. 7, 8 Platyceras trilotatum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 316, pi. Ivii, ._,.., t figs^5a, &,.G, 1861. . Description.-—" Body of the shell obliquely'or arcuately ovoid, trilobate: volutions three or four^ the last one- (or more) becoming free, gradually expanding to -the•>aperture; the apex closely involved and rising above the plane of the outer-volution, or sometimes on the same plane, concave towards the suture: aperture subanguiarly ovate, sinuate on the right and left sides, and the shell extended in 'front* Surface marked by two strong spiral depressions corresponding to'the sinuosities of the aperture, and crossed by lamellose stria? which are strongly undulated on the sinuosities of the last volution, and are marked by other undulations on the earlier volutions, indicating former sinuosities in the margin of the aperture." Hall, 1859. A specimen in the