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AMERICAN

PALEONTOLOGY

Vou. 6

NUME ER Si istity

June 30, 1919

arbsab

Harris Company Cornell Univ., Ithaca, N. Y. Oe eeuvaN

as

REM Saar

Po) MES

Vol.

Bull. Amer. Paleont. Frontispiece

Timothy Abbott Conrad 1803 - 1877

Isaac Lea 1792 - 1886

Sir Charles Lyell 1797 - 1875

Truman Hemingway Aldrich IS48 -

BULLETINS OF

AMERICAN PALEONTOLOGY

Vol. 6

No. 3!

PELECYPODA OF THE ST. MAURICE AND CLAIBORNE STAGES

BY

G. D. HARRIS

Vue 30, Foro

Cornell Univ., Ithaca, N. VY. WS vA Harris Co.

To The Hon. TRuMAN H. ALDRICH Who has continuously maintained that true Conradian love for

Our Eocene Mollusca from the last days of that forgetful dreamer On into the Twentieth Century this work is

Most respectfully dedicated

By the. Author

ACKNOWLEDGMENT

In ’92, during one of those pseudo- economic, or political paroxysms that formerly afflicted our federal Geological Survey, the writer, an employé of that organization, very naturally found it necessary to seek other quarters where his work in Ter- tiary Paleontology could be advantageously continued. Through a recommendation of Chief Paleontologist Walcott (now Secre- tary of the Smithsonian Institution) such a haven was found on the State Geological Survey of Texas, then being ably adminis- tered by Mr. E. T. Dumble.

Field parties had for several years been bringing into the Museum at Austin Tertiary material. A very little of this had been reviewed by Heilprin of Philadelphia, but the great mass was practically untouched.

Two seasons’ work with visits to Washington and Philadel- phia to consult type material, and atrip through Alabama and Mississippi for additional specimens resulted in getting together a fairly complete monograph on the Texas Eocene Mollusca, a MS of some 350 pages and 31 plates. The illustration was ex- cellently done by the late McConnell and the plates were actual- ly engraved. However, till this day the report has remained unpublished. But the large share of the new species were long since brought out in the Philadelphia Academy’s Proceedings, and the lists of fossils from various localities have been very largely quoted. Occasionally in the present report the writer has made use of the proof plates from his old Texas Report. But in general, it has seemed best to use photographs of material now deposited in the University collection, for, aside from their lack, perhaps, in sheer artistic beauty, they do express the finer specific idiosyncrasies oftentimes far better than do the best of drawings.

While conducting a Geological Survey of Louisiana for ten consecutive years considerable additional trans-Mississippian Eocene material was collected, especially during the early years of reconnaisasance when young Veatch’s (A. C.) delight in diffi-

cult and successful exploits brought in splendid material from hitherto unheard of localities.

While visiting Washington with pockets and bags full of material for comparison, the writer has been received by the Department of Mollusca as a prodigal son, in the spirit of true friendship. It is certainly fortunate for American Tertiary Paleontology that there has been at the National Museum a man of Dr. Dall’s erudition and sympathetic interests.

It is much to be regretted that time and means have not been at the writer's command for properly illustrating more of Conrad’s type specimens at the Philadelphia Academy. Yet with the bivalves the need is not so great as with the univalves. The facilities for work already afforded at the Academy by the curator, Dr. Pilsbry could not be better and in the near future the writer hopes to have the greater, or, as yet poorly illustrated, part, of the Conradian collection properly photographed.

Aside from the facilities the writer has enjoyed in working out his own material at various museums, mention must be made of the fact that among others, Dr. Dall of Washington, Hon. T. H. Aldrich of Birmingham, Alabama, and Prof. Whitney of Austin, Tex., have sent specimens for comparison and have loaned co-types and furnished materials used in various genera throughout this work as will be noted in reading descriptions and consulting the illustrations with their accompanying ex- planations.

PELECYPODA OF THE ST. MAURICE AND CLAIBORNE STAGES

BY

G. D. HARRIS

In a general way the Eocene series of the Gulf border may very properly be subdivided into five stages,—three representing for the most part marine sedimentation ; two palustrine though lo- cally becoming marine and filled with beautifully preserved mol- lusca. Intheir natural sequence these stages are :

Jackson stage, marine

Claiborne stage, lignitic or lacustrine St. Maurice stage, Marine

Sabine stage,* lignitic or lacustrine Midway stage, marine

In the summer of 1895 the writer made a somewhat extended expedition in the Southern States east of the Mississippi, visiting and collecting from such localities as might furnish well preserved basal Eocene fossils. The results of this expedition were com- bined with observations previously made while on the Arkansas and Texas Geological Surveys, and published as Bulletin No. 4 (Amer. Pal.) June, 1896. After another extensive field season ina slightly more southern latitude along the outcropping of the next higher stage, Bulletin No. 9 appeared (June ’97) on the Pelecypoda of the Lignitic Stage; the Gastropoda, Pteropoda and Cephalopoda followed in May ’99 as Bulletin rt.

*Now known as the Sabine stage from the river by that name separ- ating Sabine County, Texas and Sabine Parish, La. and showing good fossil-

6 BULLETIN 31 6

Many things have delayed the appearance of our work on the higher Hocene stages. First among these has been an almost constant connection with National, State or private surveys de- manding a vast amount of time on subjects generally but distant- ly related to Tertiary paleontology, yet admitting of occasional studies of out-of-the-way places in middle Eocene areas, hence in- creasing our collections and adding slowly to our knowledge of these interesting stages. Five timesin our goings and com- ings to the Gulf region have we touched at the very center of mid-Hocene interest, Claiborne Bluff, collecting always new fossils and facts for future study and illustration. But from the very nature of human affairs there must come a time when field work is temporarily suspended and notes and fossils are given un- divided attention if this work, now so long delayed, is ever to appear.

it would doubtless be more in accordance with precedent and perhaps more logical to treat here of the mollusca of the St. Maurice stage only, the so-called Lower Claiborne of our various previous contributions. For, the more we study the so-called Claiborne and Lower Claiborne faunas the more distinct do they appear. ‘The Lower Claiborne or St. Maurice represents an age of general depression along the Gulf border with widely distribut- ed molluscan remains ; the Claiborne, a somewhat uplifted lacus- trine condition with rarely local depressions sufficient to allow of the incursion of the warm seas from the south with their teeming marine life. One notable example of this kind is to be seen at the famous Claiborne bluff on the Alabama, though in the roadside

iferous outcrops alongits banks. Exception has been taken to the name Sa- bine since Penrose made use of the expression “‘Sabine River beds” to in- clude certain horizons not included within the stage as now defined. This use of a descriptive expression can scarcely invalidate the clearly defined name as proposed by Veatch and sanctioned by the proper authorities of the U. S. Geological Survey. Thename Wilcox, since used by that bureau lacks priority and is based on an obscure county name in Alabama, one that in no way carries the historical significance of Sabine, nor would it be found on general maps of the United States.

7) ST. MAURICE AND CLAIBORNE PELECYPODA 7

scarcely a mile above, the ‘‘sands’’ give way largely to lignitic deposits. However, the complete differentiation of these two stages has not been satisfactorily carried out in western Texas and in the Carolinas. Nor even in Georgia do we know to a certainty the distribution of each of these stages. Again, there is an advantage, physical at least, in having species of adjacent stages figured together on the same plate.

References to the literature together with discussions of local and general stratigraphy will follow in due season. Hxtensive synonymies and discussions of provenance and relationship of species are withheld for publication in PALHONTOGRA PHICA AMERICANA. We are interested here solely in illustrating and describing the mid-EKocene molluscan fauna of our southeast- ern coast. Some species run through several Eocene stages and may have already been referred to and figured in previous Bull- etins on the Midway or Sabine stages. The mid-Hocene facies of such species will be herewith figured, but the original de- scription must be found by referring to former Bulletins.

G. D. Harris. Cornell University, Hebel. 1OLo;

iS aae BULLETIN 31 8

PEL EG we @DA,

Ostrea alabamiensis Lea, Plates 1-5. O. gigantissima Finch (in part), undescribed, A. J. S., vel. 7, 1824, Pp. 39. O. alabamiensis Tea, Cont. to Geol., p. 91, pl. 3, fig. 71, 1833. O. semilunata Yea, ibid, p. 90, pl. 3, fig. 69. O. lingula-canis Lea, ibid, p. 92, pl. 3, fig. 72. O. pincerna Vea, ibid, p. 92, pl. 3, fig. 73. O. georgiana Co., Jr. Acad. Nat. Sci., Phila., 1834, vol. 7, p. 156. O. contracta Con., Proc. Acad. Nat. Sci. Phil., 1855, p. 269; also Mex- ican Boundary Surv., pl. 18, fig. 1. O. alabamiensis and georgiana Con., Am. Jr. Conch., vol. 1, 1865, p. 14-15. O. alabamensis de Gregorio, Mon. Faun. Eoc., 1890, p. 175, pl. 18. O. alabamiensis Cossm., Ann. de Géol., 1893, p. 18. O. claibornensis Con. MS, Harris, Bull. Am. Pal., vol. 1, p. 3, 1895. Ostrea alabamitensis Har., ibid., p. 3. O. alabamensis and georgiana (in part) Dall, Tr. Wag. Free Inst. Sci., vol. 3, p. 678-683, 1895. ? Ostrea vomer Clark & Martin, Geol. Surv. Md. Eoc., p. 193, pl. 1, rgro. Lea’s original description.—Shell subelliptical, curved behind, crenu- late on both sides of the beak ; beaks recurved, pointed. Dita ea Length 2.1, Breadth 1.5 of an inch. A single valve only of this species has been received by me. The ex- terior of this is roughly squamose. ;

The most remarkable character of this species is the fine di- varicate sculpturing of the corneous epidermis. O. prismatica Gray, as described by Reeve from Panama (Conch. Icon. pl. 1. fig. I) possesses this feature to some extent. Of the four forms figured and described by Lea, O. alabamiensis represents most clearly the normal form, hence the name has been retained in preference to the others, although one was described on a previous page. Lea’s figure of alabamiensis is, however, a little mislead- ing in that it appears to represent a fairly thick shell. The speci- men from which the figure was drawn is thin and pearlaceous. O. semilunata evidently grew in close proximity to a root, stick, stone or other object and became somewhat distorted. Its pe- culiar shape as figured caused Conrad to refer it to his O. selle- Jormts (Am. Jr. Conch., vol. 1, p. 15, 1865), amistake he certainly

9 ST. MAURICE AND CLAIBORNE PELECYPODA 9

would not have made had heever seen Lea’s shell. Occasionally at Claiborne and especailly at Gosport this species shows speci- mens of six or more inches in length (pl. 1). Some, of this character, in the Philadelphia Acad. Coll., are labelled in Con- rad’s handwriting Ostrea claibornensts.

We strongly suspect that the surrounding conditions at Claiborne during the deposition of the ‘‘sands’’ were not favor- able for Oyster development. Shells grown to considerable size are often thin, very gibbous and Azomza-like (pl. 2, fig. 1 and pl. 6, fig. 1). These specimens show the exterior radiating lines already referred to at great advantage. If the oyster lives be- yond this stage, it seems diseased and is usually very much de- formed in some way or other (pl. 2, fig. 3). Parts may be very thin or thick ; exteriorly smooth or highly foliated (var. /rionzs pl. 5, fig. 1; marginal crenulations may be present or absent ; a great lengthening of the shell is of common occurrence, causing a contracted appearance toward the beak. Hence the derivation of the variety contracta (Proc. Ac. Nat. Sci. Phila., KOH5, Pp: 200 >and Mex: B' dy. Surv.; p. 160, pl. ne; digs, a bic d, 1857) of the Rio Grande section. Not all the specimens along the river are ‘‘contracted.’’ The more southerly, Jackson ex- posures as a rule furnish the typical coztracta while the northerly exposures, furnish more nearly typical alabamiensis. In this sec- tion of the country in late Eocene times, it appears that condi- tions were less hostile to this type than at Claiborne. Far to the east again, in eastern Georgia, South Carolina and North Caro- lina the georgzana flourished in great profusion. ‘That this is the eastern equivalent of contracta or well-fed alabamiensis, we have no doubt. It often shows the peculiar, radiate marking of the exterior referred to above.

Type.—Alabaniensts. No. 5439 Phila. Acad. Of contracta, U. S. Nat. Mus.

florizon.—-St. Maurice, Claiborne and Jackson Eocene.

Specimens figured.—Mostly Mus. Cornell Univ. ; but pl. 4 and pl. 5, figs. 1 and 3 from Texas State Mus.

Localities.—Texas : Along the Rio Grande 2 mls above San José, just above the mouth of Good Cr., Zapata Co. ; at Webb-Za-

10 BULLETIN 31 Io

pata Co. line, 5, and 13 mls below Laredo ; Cedar Creek and Dunn ranch, Robertson Co. ; 5 mls W. of Crockett, W. of Caney Rayou, San Antonio road, Houston Co.; 4 mls N. E. Alto, Cherokee ; S. E. Corner of Frio Co.

Large jspecimens described by Conrad as O. contracta were from ‘‘Oyster Point, near Mier, Tex.’’ Other localities for the same are: Rio Grande at Carrizo, above Roma, 15 mls below Carrizo and at Campbellton, Atascosa Co.; Oyster Bluff, Brazos River, Milam Co., 2 mls above the mouth of Pond Cr. South Fork of Hurricane Cr.

Louisiana ; Sabine River, near Columbus as in nearby E. Tex.; 3 mls S. KE. of Negreet; in form of cast 2 mls N. of Plaindealing.

Alabama : Claiborne, Gosport, Lisbon, Hamilton Bluff.

Georgia - Grovetown, Shell Bluff.

South Carolina : Rocky Swamp, Orangeburg Dist.

LVorth Carolina; very abundant on the Neuse and Trent Rivers. See especially exposure near R. R. bridge at Pollocks- ville.

The localities mentioned above are those from which we have personally identified this form. Various authors, especial- ly Dall, have mentioned this species (under the name of georgiana) as having a wide Oligocene distribution in Florida, as the ‘‘/ezt fossil’ of the Grand Gulf (See Trans. Wag. Free Inst. Sci., vol. 3, p. 685, &c). Wecannot speak with authority on the wide geologic range here suggested.

Ostrea selleformis, Plates 6-8.

O. selleformis Con. Foss. Sh. Tert. Form., p. 27, pl. 13, fig. 2, 1832.

O. radians Con. ibid, fig. 1.

O. divaricata Lea, Con. to Geol., 1833, p. 91, pl. 3, fig. 70, 1833.

O. selleformis Con., Proc. Nat. Inst., 1842, p. 192, pl. I, fig. I.

O. selleformis Heilp., Ann. Rept. (IV), U. S. Geol. Sury., 1883, p. 21s Np 562, NSS. 2)>) plesepratt mens

O. selleformis de Greg., Mon. Faun. EKoc., p. 175, pl. 19, ff 1-12, 1890.

O. selleformis Dall (in part), Tr. Wag, III, p. 677, 1808.

O. selleformis Clark and Martin, Geol. Surv. Md. ; Eocene, p. 192, pls.

48, 49, 1901.

Ir ST. MAURICE AND CLAIBORNE PELECYPODA II

Conrad describes the one valve of this species as radians: Oblong, compressed, lobed and flexuous on one side; the ribs numerous, radiated ; beaks very small, not prominent, pointed and a little curved laterally, Vance’s Ferry, S. C.; Claiborne, Ala.

O. selleformis: Oblong, convex, thick and ponderous, lobed; one side of the larger valve profoundly sinuous and the opposite side gibbous ; smaller valve sinuous and a little convex ; dorsal margin long and slightly arched, with both extremities obtusely rounded.

Since these are but different valves of the same species, Con- rad’s intimation that there are two valves of his selleformis was based on an error. ‘This error, however, he corrected in 1842, strangely choosing selleformis instead of radians, a more appro- priate name perhaps, and coming first in his original publication.

As species are most generally defined in modern literature several of the sel/eformzs-like forms here included under one name might be regarded as distinct species.

With a small amount of material at hand, from a limited number of localities, perhaps no cne would hesitate to affirm that very well defined species could be differentiated. But with the increase of material from intermediate localities the seeming dis- tinctness of certain types rapidly disappears. Nevertheless there is considerable fixity to some of these varietal forms and it is well worth while to have them defined and named and have their interrelations and stratigraphic significance pointed out.

0. selleformis var. smithvillensis, Plate 8

From Smithville, Tex., are derived numerous small speci- mens with thin shells, and rarely, larger representatives, show- ing one plicate valve and one nearly smooth valve, giving a somewhat compressirostvra appearance. Yet the plications are yery numerous and without the foliations and squamose charac- ‘ters of the latter species. ‘The flat valve shows signs of weak pli- cations. ‘There is an entire lack of a marginal kink or fold—the feature doubtless first suggesting the name selleformis.

0. selleeformis (typical) Pls. 6 and 7.

Rarely in Texas do the large, ponderous, saddle-formed mu- tations of this species occur. From near Columbus on the Sabine,

bet is)

BULLETIN (31 12

eastward through Wautubbee and Hickory, Miss., Claiborne, Coffeeville and Lisbon, Ala.; Shell Bluff, Ga. ; Vance’s Ferry, 5S. C.; City Point and Piping Tree, Va., these heavyweights are of common occurrence.

Young, comparatively thin specimens of this type havea wide distribution in the St. Maurice beds of Texas, and are not uncommon eastward to the Carolinas. In these the posterior kink is not always well defined and now and then there isa slight trace of radial sculpture on the flat valve. (See pl. 6.)

Var. divaricata Lea simply represents young individuals with- out a definite posterior kink and without a posterior cardinal ala- tion. Such specimens are occasionally found with other varieties at Claiborne, Ala.,- Negreet, Wa., and elsewhere. »)(Seeyplye, fig. 7. Dall mentioned also Natchitoches Parish, La., Choctaw Bluff, Ala., and City Point, James River, Va.

Var. vermilla de Greg. Like adzvaricata but with posterior alation of cardinal area. Described from Claiborne; our best specimens from Bienville Par., La. (See pl. 9, fig. 8.)

Type.—Phila. Acad. ; from the lower calcereous layers, Claiborne Bluff, Ala.

Florizon.—St. Maurice and Claiborne Eocene.

Specimens figured.—P\. 6, figs. 2-12, young specimens from the base of the bluff at Claiborne ; pl. 7, adult from the same lo- cality; pl. 8, var. smzthvillensis, C. U. Museum, from Smith- ville, Tex, ; pl. 9, fig. 7, var. divaricata, C. U. Mus., from New- ton, Miss. ; pl. 9, fig, 8, var. vermzlla, C. U. Mus., Beinville Par- slag bel

Ostrea selizformis (?) var. lisbonensis, Pl. 9. Figs 1-6

We have never felt satisfied with the general reference of this form to sel/leformts and have long kept it apart from Conrad’s species in our collections under the designation of /zsbonensis. It occurs large and well defined at Lisbon, Ala., but it is in Louisi- ana where it is typically and extensively developed. When adult, it reaches about one-half the dimensions of the large sel/eformzs in the bluff at Claiborne. The coarse plications, aviculoid form,

13 ST. MAURICE AND CLAIBORNE PELECYPODA 3

posterior emargination and convexity of both valves which, by the way, are of a thick, dense make-up, distinguish it from the thin, nearly flat, multicostate, less aviculoid, less emarginate and early kinked young and adolescent individuals of sel/leformzs.

Whitfield described in U.S. Geol. Surv. Mon. IX, p. 222, pl. 29, fig. 2, 1885, acast of an oyster from the Shark River Ho- cene beds of New Jersey under the name of O. glauconotdes, and referred specimens from the base of the bluff at Claiborne to this species. But, even with the New Jersey type in hand (kindly ioaned by State Geologist Ktimmel) it is impossible to state whether the New Jersey and Claibornian specimens should be re- ferred to the species. The former evidently had a much thinner shell and was inflated near the beak.

Type.—Paleont. Mus. Cornell Univ.

Horizon.—St. Maurice Eocene.’

Specimens figured.—Chestnut, La.; Harris Collection, now deposited at Cornell.

Localities.—Collier’s Ferry, Burleson Co., likewise from Bra- zos, Robertson, Cherokee Co’s., Tex. ; Natchitoches, Marble Q’y, Chestnut, 35 mls $. EH. of Creston, in Bienville Phrish, and at Chautauqua, La; Lisbon and Hamilton Bluff, Ala.

Fig 1. Ostrea var. perplicata Dall Variety perplicata Dali

Dall in his Florida Fossils as published in the Transactions of the Wagner Free Institute of Science, vol. 3, p. 678, names a

a .

14 BULLETIN 31 14

variety of selleforimis, perplicata from ‘‘Kocene, Caton’s Bluff, Conecuh River, Alabama; L. C. Johnson.’’ ‘This is an inalate form of the same stock as our /sbonensis. ‘The description reads :

‘Shell very heavy, arcuate triangular, with coarse, rounded, numerous divaricating ribs (twenty-five to forty), no auriculation or posterior sinuosity of the margin near the hinge, the upper valve extraordinarily ponderous, the general form regular and uniform, the valve margins nearly or quite simple.

The figures herewith shown are of ‘‘Co-types’’ kindly fur- nished by Dall, and are in the U. S. Nat. Mus. collection.

Ustrea vicksburgensis, var. ludoviciana. n. var. Pl. 10, figs. I-10

In Conrad’s description of O. vicksburgensis he gives no characteristics that would necessarily demand that this variety be referred to this species. The description (Proc. Acad. Nat. Sci. Phila., 1847, p. 296) reads as follows :

Plicated ; very irregular and adhering, the upper valve not fiat, but swelling in anirregular manner. Height 13 in.

Their is nothing peculiar about this shell, yet it is clearly distinct from any other species of the American Tertiary hitherto described. Common.

This species is again described in the Journal of the Acad- emy, (vol. 1, p. 126) and a figure is given (pl. XIII, fig. 5) but with this additional information the species would still be ill de- fined.

It has sometimes been referred to O. panda Mort. on account of fig. 10, pl. 19, of Morton’s Synopsis. The name panda, how- ever, applies only to the species from the vicinity of St. George’s on the Delaware and Chesapeake canal, referred primarily by Morton (1830, A. J. S. vol. 17, p. 284) to evistagalli with a ques- tion, and figured as such in vol. 18, pl. 3, fig. 22. The name panda was proposed in 1833 (zd. vol. 23, p. 293) for this Cre- taceous species. In 1834, in the ‘‘Synopsis &c’’ Morton includes several Tertiary specimens under the name Janda and figures one on pl. 19, he. 10. ' Gabb, 1861, Ceroc. Phila: Ac) seempaiemis impropriety proposed the name orton for the Tertiary speci- mens. An examination of the specimens in the Phila. Academy

15 St. MAURICE AND CLAIBORNE PELECYPODA 15

Gabb had before him in naming mortonz, is quite sufficient to prove their identity with vicksburgensis. One specimen, Morton’s original of fig. 10 and used by Gabb as one of his mortonz, had a general resemblance to our form /adoviciana. The radiating ridges are rather sharp plications than rounded ribs so common in /zdo- viclana—somewhat like the ornamentation of the Miocene szbfa/- cata. It passes insensibly into coarsely plicate wicksbhurgenszs two or three inches in diameter.

Varietal characterization.—General form and size as figured ; left valve gibbous, extended at lower posterior margin; ribs on post-umbonal slope faint, generally about six in number ; anter- iorly, ribs strong, 6-12 often bifurcating, especially strong from beak to posterior margin. Lesser valves concave, decidedly of the appearance of the lesser valves of some small Hxogyras.

Type.—Harris collection at Cornell Univ. No’s. 2-6, Natch- itoches, a.-- 1, 7-10, Chestnut, La.

Geologic horizon.—St. Maurice Eocene.

Localities.—Especially in Natchitoches Parish, La., about Natchitoches, Provencal, Robeline and Chestnut ; also Bienville Parish and Columbus, Sabine Parish. That it occurs as far east as Alabama several not exactly localized specimens from this State in the Museum attest. Long drawn out, claw-shaped mu- tations are common along the Sabine River, near Columbus.

Ostrea johnsoni, Pl. 10, figs. 11-15.

O. johnsoni Ald., Bull. 1, Ala. Geol. Surv., 1886, p. 41, pl. 6, fig. 6.

Aldrich’s original description.—‘Shell large, thick ; both valves con- vex; beaks pointed in lower valve; breadth of shell greater than length ; both valves strongly plicate, generally with six folds, the plications becom- ing very deep with age, the concave part between the two basal folds run- ning out into a long curved tongue; surface strongly laminated, lamin terminating at edge of shell; attachment scar not visible ; ligamental area with a rather deep, transversely striated furrow in the lower valve, shallow- er and broad in the upper; muscular scar, large nearest the base and pos- terior margin ; curved, spatulate, nearly straight on upper side.

This form seems to be confined tothe Lower Claibornian above the Buhrstone.’”’

Dall remarks (Trans. Wag. III. p. 681): ‘“Thisis an excellent species with a few strong plications, making the valves claw-like.’’

na(ON Ae BULLETIN 31 16

The number of plications varies greatly, see pl. ro.

This species seems to have a very limited range, from Cune- cah River, Ala., to Newton, Miss.

Type.— Aldrich Coll. (Johns Hopkins Univ. Mus. )

Hlorizon.— St. Maurice.

Specimen figured.—Cornell Univ. Mus. (11-13, Caton’s Bluff ; 15, Lisbon, Ala.)

Localities.—Claiborne, Lisbon, Newton, (jde Ald.) also at Caton’s Bluff, Conecuh River, Ala.

Anomia ephippioides Pl. rr, yRIgSseie3-

A. ephippioides Gabb, Ja. Phila. Acad. Nat. Sci., 2d Ser., vol. 4, 1860, p. 388, pl. 67, fig. 59. A. ephippioides Dall, Trans. Wag. &c., vol. 3, 1898. p. 782.

Gabb’s original description.—‘‘Very irregularly sub-quadrate, some- times very nearly circular, sometimes almost triangular ; convex, occasion- ally marked by longitudinal rugee, and always by distinct lines of growth ; lower valve, the muscular foramen large, ligament margin thickened.

Size of largest specimen: Length 1.5 in., width 1.3 in.”

This species ina general way resembles 4. szmplex of our coast (sometimes called A. ephippium, hence Gabb’s name). Specimens when well preserved show a peculiar postulose exter- ior, the pustules in some instances becoming elongated.

Although Gabb’s types are supposed to be in the Phila. Academy’s collection none there show the ‘‘lower valve.’’ This with a larger form usually referred to “sbonensis occurs in great abundance from the Rio Grande to the Sabine almost wherever the St. Maurice beds are represented.

Although specimens of Azomza are abundant in the Lower Claiborne (St. Maurice) of Louisiana, the pustulate type becomes rare and the generally larger, smooth //sbonensis predominates.

Type.—Phila. Acad. Nat. Sci.

Florizon.—St. Maurice Eocene.

Specimens figured.—Cornell Univ. Mus.

Localities.—From 13 mls below Laredo, northeastward through- out ‘Texas to the Sabine about Sabinetown.

LF ST. MAURICE AND CLAIBORNE PELECYPODA 17

Anomia lisbonensis, Plann.) Bigs: 6-10

H.. ephipptioides var. lisbonensis Ald. Bull. 1, Geol. Sury. Ala., 1886, p. 41, pl. 4, fig. 6. zl. lisbonensis Dall, Trans. Wag. &c, vol. 3, 1898. p. 781.

Aldrich’s characterization of lisbonensis.—‘Shell thin, pearly, subor- bicular ; upper valve smooth, slightly wrinkled onthe umbo ; lines or growth distant; hinge line doubly sigmoid, the extremities winged. Muscular scars indistinct.

Locality.—Lisbon and beds at base of Claiborne Bluff.

The type is externally marked with broad radiating bands of color. On comparison with A. ephipfoides Gabb, it appears much larger and more transverse ; that species is not smooth externally, and is often plicate. It occupies the same horizon however.”’

We have several good specimens of the larger valve of this form from these type localities, some of which are shown by the figures, 6, 7, 8. We would not be at all surprised if some of the more radiately marked specimens, from the Lisbon vicinity are the same as Conrad’s A. jugosa although he labelled the type of that species (now in the Academy’s collection) from the ‘‘White Limestone of South Carolina,’’ The interior of that specimen seemed to us more like hard gray marl than ‘‘white limestone.”’ Conrad’s figure of jugosa shows the feeble ribs much too distinct- ‘ly. They areremarkable for showing a down-bowing of the lines of growth as they pass over the obscure costee.

Asremarked above, the pustulose specimens of 4zomza in our collections are Texan. ‘The markings in “sbonenzs, besides con- centric lines of growth consist generally of microscopic hachures as Shown by figure 9. ‘There is, too, a slight tendency to show interrupted radial foliation. Figs. 9, 10 are from the same local- ity in N. W. Louisiana, Hammett’s Branch. Fig. roshows how even here there is a tendency for the otherwise /zsbonensis to be- come slightly pustulose in places.

Type.—Aldrich Coll., now at Johns Hopkins Univ.

Fforizon.—St. Maurice Eocene.

Specimens figured.—Geol. Mus., Cornell Univ.

Localities. —Common in Texas with ephippiordes ; Mt. Leban- on—Hammett’s Branch, Natchitoches, Chestnut, in Louisiana ; Lisbon and base of bluff at Claiborne, Ala. Thin, delicate spec-

18 BULLETIN 31 18

imens of this species are common at Hamilton Bluff, Ala. Anomia navice!lodies var. hammetti Har., PL 12. (Bigsw ieee

Varietal characterization.—Shell long-ovoid as illustrated : rather thick, very flat, somewhat curved ; exterior marked by a large number of irregularly divaricating, radiate riblets having a tendency to develop minute, hollow prickles ; broad, concentric undulations irregularly disposed.

Along with this upper left valve there are fragments of heavy right valves, shown on pl. 11, figures 4 and 5 that in all probability belong to this species, though we have not thus far found two valves together to prove the question beyond a doubt. These show a remarkable thickening about the opening as well as about the whole cardinal -area.

Type.-—Deposited in Pal. Mus., C. U.

Florizon.— St. Maurice Eocene.

Specimens jigured.—F rom Hammett’s Branch, La.

Localities—Hammett’s Branch and Bayou Negreet, La.

Plicatula filamentosa Con., Pl. 12, fig. 3, et. seq.

See Bull. Am. Pal. vol. 2, p. 233. Also P. filamentosa Dall, Trans. Wag. &c., ’98, p. 762.

The appearance of radii within young shells and their grad- ual obscuring by calcareous thickening within is well shown by figures 4, 5 and 6. De Gregorio (Koc. Faun. Ala., p. 179) has described a young valve like fig. gas ‘‘Spondylus amusstopse.”’ Exteriorly just outside the irregular attachment area, faint radi- ating plications appear in young forms, especially of the upper Sabine horizon. Next, strongly marked concentric lines of growth at certain regular intervals giving the appearance of fim- briate radiating lines ; fourthly, deep radial folding, often mainly sub-marginal. ‘The Sabine forms have more regular and numer- ous plications than the later specimens of this species. But the concentric lines with the tendency to produce ribs of a second or- der is already noticeable in a few specimens from Hatchetigbee.

Typical jfilamentosa must be regarded as the Claiborne form, shown by figs 3-8. A comparatively small number of plications,

19 ST. MAURICE AND CLAIBORNE PELECYPODA 19

superposed by fine secondary rays anda strong tendency to have the hinge line extended, giving the shell an auriculate aspect are features tending to differentiate this from earlier varieties.

Variety concentrica Dall (Trans. Wag., p. 762.) ‘‘Is marked by a total disappearance of radial striz and the development of fine, even, regularly spaced, concentric, elevated sculpture all over the shell.’’ This tends to give way to the usual flamentosa structure when a dozen or so specimens are examined from any one local- ity. (Seefigs. 9 and 12.)

Variety planata (Ald., Jr. Cin. Soc. Nat. Hist., vol. 9, 1886, p. 45, pl. 2, fig. 20) is one of the commonest forms in the St. Maurice. Here the wrinkling of the concentric lines at even in- tervals causing radii of various orders or dimensions, reaches the limit. So important does this feature become that the original concentric lines are practically obliterated. and rows of scaly spines, hollow and long in certain rays are the dominating feature of the shell surface. See fig. 17. Large old specimens like fig. 16 often show clearly a tendency to become strongly plicate about the basal margin. ‘These plications are however, more nu- merous than in the later Claiborne sand specimens.

Types.—P. filamentosa (Phila. Acad.) ; concentrica (U.S. Nat. Nus.) ; planata (Ald. Coll., J. H. Univ. Coll.)

fforizon.—Uppermost Sabine to Jackson.

Specimens figured.—Cornell Univ. Paleont. Mus.

Localities.—For filamentosa, sen. sty., Claiborne sands ; for concentirca, pre-eminently the Texas variety, common in Cher- okee, Anderson, Houston and Robertson Co’s; Columbus and Negreet, Sabine Pam., La., Wautubbee, Miss.; for flanata, Newton, Hickory, Wautubbee, H. Johnson’s, Miss. and St. Maurice, Cooper’s Well, Winnfield, about 1000 ft., La.

Pecten deshayesii Plo i340 igs: 2-7.

P. deshayesii Vea, Cont. to Geol., 1833, p. 87, pl. 3, fig. 66.

P. lwelli Veatd. p, 87, pl. 3, fig. 67.

P. deshayesii de Greg., Mon. Faun. Eoc., 1890, p. 180, pl. 21, figs. 12-15.

Lea’s original description.—Shell orbicular, rather compressed ; ears

20 BULLETIN 31 20

nearly equal; substance of the shell rather thick ; ribs about twenty-one, large, alternating with as many small ones, all imbricate ; beaks pointed.

Diam. : 5 Length 1.3, Breadth 1.3 of an inch

Lea’s original description of lyelli.—Shell longitudinal, rounded be- low, angular above, compressed ; ears very unequal, having a channel on the larger one ; substance of the shell thin; ribs about twenty-ywo, round- ed, slightly imbricate ; beaks acutely angular.

Diam. ‘ 3 Length .8, Breadth .7 of an inch.

There seems to be considerable uncertainty as to what, and how many species of Pecten really come from the Claiborne sands. Dall says regarding deshayesi (Trans. Wag., III, p. 738):

‘‘This species is positively known to occur in the Jacksonian at Clai- borne and elsewhere, but I have obtained no specimens from the vast amount of marl belonging to the true Claiborne sands horizon which has come under my notice.’’

Cossmann finds this species ‘‘excessivement rare’’ in his bar- rel-full of sand.

Our various collection at the same horizon and place, when- ever at all extensive, have never failed to produce several good specimens of /ecten of this and perhaps other nearly related forms.

The specimens of this so-called species found in famous ‘“‘sands’’ are very variable in outline, size and markings. | What one usually finds is just what Lea described: one or more large left valves, quite highly ornamented, along with smaller right valve with simpler ribbing. The right valves seem more elong- ate, just as Lea remarks under his /ye//7. Along with these, one generally secures fragments, at least, of large right valves with flat, smooth, broad ribs, regarded by some as having been worn. (See iploy ra eS)

The right valve while young possesses a very prominent an- terior byssal ear with a deep notch, and a broad shallow groove extending to the beak, also about 5 imbricate rays; posterior ear much smaller, forming an angle of approximately 90 de- grees with the hinge line and having about 5, often double, rays; general shell surface with ribs equalling interspaces in width, about 18 well defined ribs on the face of the shell, with half a dozen or so fine radiating lines or subdivided riblets on

QI St. MAURICE AND CLAIBORNE PELECYPODA 21

the lateral umbonal margins; surface ornamentation, imbricate concentric lines ; ribs often showing an incilnation to bifurcate on marginal areas, at least a deeply incised line is often seen on the tops of the ribs in these regions; near basal margin there is a tendency to show obscurely, however, three raised lines on top of main ribs and one or three lines in the inter-costal area.

Left valve while young showing markings similar to those described above, with more nearly equal ears, however, anda tendency to show at an earlier age three lines on top of the ribs; and a strong line (often between two others) between the ribs , irregularities like subdivision of coste, increasing comparative width of interradial spaces, great increase in radiating, fimbriate lines on top of ribs on their sides and in interspaces, apparent; shell deepening rapidly with age.

Occasionally on certain portions of the exterior of the left valve a strong bi-partite structure is seen in the ribbing. This has given rise to the varietal name #7mus by de Gregorio. We do not think it of even varietal rank.

Concerning the type of deshayes? in the Phila. Acad. it may be noted+that it shows 20-22 primary, with as many inter-ribs ; the latter apt to be on the anterior side of the intercostal space; traces of tertiary riblets; few signs of riblets superim- posed on primary ribs; finely, evenly crinkled, concentric in- cised lines on ears.

The type specimen of /yel/Z has about an equal number of ribs ; but slight traces of intercostee and concentric line ; ribs not showing bifurcation as plainly as is indicated by fig 7, pl. 13 of this work.

Types.—Philadelphia Acad. Coll., Cat. Nos. 5425, 5426.

Localities and Horizon.—Typically in the Claiborne sand horizon. A specimen seemingly of the /yel/7form is in our col- lection from the Orangeburg district, S. C.

Specimens figured.—Collections at Cornell Univ.

Pecten wautubbeanus Dall, PIA Eigs) 1.25304)

P. (Chlamys) wahtubbeanus Dall, Trans. Wag. &c, 1898, vol. 3, p. 736, pl. 34, fig. 9.

22 BULLETIN 31 22

Dall’s original description.—Shell small, flattish, with small, unequal ears and rounded disk ; fourteen or fifteen ribs carrying basally three dense- ly finely imbricated, rounded threads, the interspaces narrower with two crenulate threads; submargins with close, fine, imbricate threads ; ears prom- inent, with a deep wide, byssal notch, radiately imbricate with coarse ele- vated radial threads; interior with shallow sulci, the cardinal crura devel- oped but no lirae on the disk. Alt. 22, lat. 22mm.

This species differs from the Claibornian* . deshayesti Lea by its threaded and less individualized ribs, its similarly sculptured valves, more conspicuous notch, and concentric sculpture and smaller size when adult.

We have emended the spelling of this species, the “‘h’’ having crept into the name from bad orthograpy of the collector. Dall states that this species is ‘‘abundant at Wautubbee.’’ Our col- lections furnish many fine specimens from Wautubbee, but we scarcely feel like giving it the wide geologic range implied in “‘Claibornian and Jacksonian of Louisiana, Alabama and Mississ- ippi.’’

This species is extremely variable in appearance, even at the type locality. The right valve seems to be far more abundant and is flatter than the left andis moreapt to assume a worn ap- pearance (see fig. 1). While the ribs, about the periphery in the right valve, nearly always show the tri-partite markings described by Dall, such secondary ornamentation on the left valve are far less conspicuous though present on the lower margin of the shell (see fig. 3). On the type specimen, however, such markings are well defined.

Whenever the middle one of the three riblets is strongest, then, whether the rib be worn or intact, it apearsnarrow. When- ever the lateral riblets are well developed the rib has a broad ap- pearance and the interspaces seem narrow and deep. In extreme cases the riblets are not distinctly developed but the imbricate lines of growth are welldefined. The general aspect of the shell is accordingly greatly changed. Quite often, however, after a very marked growth line, the tri-partite ornamentation reappears. A very gibbose, perhaps somewhat pathologic specimen in our

*Note that on p. 738, Trans. Wag. III no Pectens are known from the Claiborne sand.

23 St. MAauRICE AND CLAIBORNE PELECYPODA 22

collection from near Negreet P. O., La. shows this feature in a remarkable degree. The broad ribbed variety we have named cainet, see below. Also see fig. 8, type of variety. From the selleformis, light-colored layers near the base of the bluff at Clai- borne thin, varietal forms are found, one of which herewith fig- ured (fig. 5) is quite as large as the average deshayest from the sends above. It is characterized by the scaly spinosity of the b1- partite ribbing shown on valves of w#llcoxi Dall (fig. 6), and de- scribed also as deshaysei var. tirmus by de Gregorio.

The intimate relationship of some forms of deshayest and waz- tubbeanus may also be noted by the fact that the usual small right valves generally known as Jye///, in the collection of the U.S.

Nat. Mus., No. 116,012, are classed as wautubbeanus.

Type.—U. S. Nat. Museum.

Florizon.—St. Maurice Eocene.

Specimens figured.—Wautubbee and Hickory, Miss. var. ; fig. 5 from base of bluff at Claiborne.

Localities. —Simpkins place, 3 mls S. E. of Negreet, and St. Maurice, La; Wautubbee, Hickory, 8 mls W. of Enterprise, Miss. ; 3 mls S. W. of Orangeburg, S. C.; Coffeeville, base of bluff at Claiborne, Ala.

Pecten (wautubbeanus var?) willcoxi Dall, Pl. 14. Figs. 6, 7.

P. ( Wautubbeanus) var. willcoxi Dall, Trans. Wag. &c., vol. 3, 1898, P. 737, pl. 29, fig. 4.

Dall’s original description—Shell small, broad, flattish, thin ; left valve with about sixteen narrow, rounded, elevated ribs, with somewhat sparse, regularly spaced prickles on their tops; between the ribs are similar, but lower and smaller, non-dichotomous radial threads; submargin very narrow, nearly plain, with faint Camptonectes striation ; ears small, subequal, except the byssal ear, which is longer, narrow, with a deep sinus and con- spicuous fasciole, and about sixty scabrous radii, the right posterior ear with concentric striz and only faint traces of a few radii; the ears on the left valve similar, with five or six strong scabrous threads ; internal basal margin of left valve with short flutings in harmony with the radial sculpture ; the disk not grooved ; in the right valve the internal channels are more pro- nounced ; the right hinge line has a single crural ridge parallel with the margin on each side ofthe pit. Alt. 23, lat. 24 mm.

This form is closely related to P. wautubbeanus, from which it differs by the isolated character of the prickles on