BlLLETIM 31 



PELECVPODA 



Ostrea alabamiensis Lea, Plates 1-5. 



(). o!o-a)if!ssi}iia Finch (in part), nndescril:)ed, A. J. S., vcl. 7, 1824, 



P- 39- 

 O. alahamieusis Lea, Cont. to Geol., p. 91, pL 3, fig. 71, 1833. 

 O. semilunata Lea, ibid, p. 90, pL 3, fig. 69. 

 O. Uugula-ianis'Li^a., ibid, p. 92, pi. 3, fig. 72. 

 O. piiicerna Lea, ibid, p. 92, pi. 3, fig. 73. 



O. geoygiana Co., Jr. Acad. Nat. Sci., Phila., 1834, vol. 7, p. 156. 

 O. contrada Con., Proc. Acad. Nat. Sci. Phil., 1855, p. 269; also Mex. 



lean Boundary Surv., pi. 18, fig. i. 

 O. alabamiensis and georgiaua Qor\., Am. }t. Conch., vol. i, 1865, p. 



14-15- 

 O. a/aba//it'nsis de Gregorio, Mon. Faun. Eoc, 1890, p. 175, pi. 18. 

 O. a/abaniiensis Cosstn., Ann. de G^oL, 1893, p. 18. 

 O. daiboniensis Con. MS, Harris, Bull. Am. Pal., vol. i, p. 3, 1895. 

 Ostrea alabamiensis Har., ibid., p. 3. 

 O. alabaiuefisis and geo/giana (in part) Dal], Tr. Wag. Free Inst. Sci., 



vol. 3, p. 678-683, 1895. 

 ? Ostrea vomer Clark & Martin, Geol. Surv-. Md. Eoc, p. 193, pi. i, 1910. 



Lea's original description. — Shell subelliptical, curved behind, crenu- 

 late on both sides of the beak ; beaks recurved, pointed. 



Diam. . . . 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 roughl}- squamose. 



The most remarkable character of this species is the fine di- 

 varicate sculpturing of the corneous epidermis. O. prismatica 

 Gray, as described b}' Reeve from Panama (Conch. Icon. pi. i. 

 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 oi alabamiensis is, however, a little mislead- 

 ing in that it appears to represent a fairh' thick shell. The .speci- 

 men from which the figure was drawn is thin and pearlaceous. 

 O. semilnnala evidently grew in close proximity to a root, stick, 

 stone or other object and became somewhat di.storted. Its pe- 

 culiar shape as figured cau.sed Conrad to refer it to his O. sellce- 

 forviis (Am. Jr. Conch., vol. i, p. 15, 1865), a mistake he certainly 



