TERTIARY MOLLUSCA. 129 



Localities. — Rifle Butts, Wetherell Point, Hodge's Bluff, Long 

 Island, Blizzard Mill, and, doubtfully, 0.5 mile north of McKinnon's 

 Mill, and Friar's Hill, Antigua, stations 6854, 6858, 68£2, 6869, 6874, 

 6888, 6856, 6875, Vaughan. 



Types. — Philadelphia Academy of Sciences, Nos. 1653 and 1655. 

 Figured specimens. — U. S. Nat. Mus. No. 167055. 

 Ostrea species, cf. O. trigonalis Conrad. 

 (Plate 9, Figure 1.) 



Wstrea trigonalis Conrad, Proc. Acad. Nat. Sci. Phila., vol. 7, p. 259; figured in Wailes'a Geol. 



Agric. of Miss., plate 14, fig. 10, 1855. 

 Wstrea podagrina Dall, Proc. U. S. Nat. Mus., vol. 18, p. 22, 1895. 

 Wstrea podagrina Dall, Trans. Wagner Inst., vol. 3, pt. 4, p. 682, plate 30, figs. 5, 6, 1898. 



This large, massive species resembles Ostrea trigonalis in the charac- 

 ter of its hinge, which is broad, straight, and separated into thirds by 

 a deep triangular pit in each valve. In front of the hinge the shell 

 continues at about the width of the hinge-line for about 1 cm., beyond 

 which it is rapidly expanding. The lower valve is very highly inflated 

 and broadly plicate, much as in 0. podagrina and in the plicate forms of 

 0. trigonalis and 0. vicksburgensis, all three of which appear to be 

 closely related and may be merely varieties of one species. 



Localities. — Northwest side of St. Jean Bay, St. Bartholomew, sta- 

 tions 6924 and 6925. Fragments, probably of the same species, were 

 obtained at station 6895 and at Governor's Bay, station 6919, Vaughan. 



Geologic horizon. — Upper Eocene. 



Figured specimen. — U. S. Nat. Mus. No. 167056. 



Ostrea haitensis Sowerby. 



(Plate 7, Figures 1, 2; Plate 8, Figure 1.) 



Ostrea haitensis, Sowerby, Quart. Jour. Geol. Soc. London, vol. 6, p. 53, 1850. 



O. heermanni Conrad, Proc. Acad. Nat. Sci. Phila., vol. 5, p. 267, 1853. 



O. heermanni Conrad, Pac. R. R. Rept., vol. 5, p. 326, 1855. 



O. vespertina Conrad, Pac. R. R. Rept., vol. 5, p. 325, plate 5, figs. 36-38, 1855. 



O. virginica var. califomicum Marcou, Geol. N. Amer., 1858. 



O. virginica Guppy, Quart. Jour. Geol. Soc. London, vol. 22, p. 577; not of Gmelin; 1866. 



O. vespertina Gabb, Pal. Cal., vol. 2, p. 107, 1869. 



O. veatchii Gabb, Pal. Cal., vol. 2, p. 34, plate 11, fig. 59; plate 17, fig. 21, 1869. 



O. haytensis Gabb, Trans. Amer. Phil. Soc, n. s., vol. 15, p. 257, 1873. 



O. haitensis Dall, Trans. Wag. Inst., vol. 3, pt. 4, p. 685, 1898. 



O. haitensis Joukowski and Clerc, Mem. Soc. Phys. et d'Hist. Nat. de Geneve, vol. 35, p. 170, 



plate 6, figs. 20-23, 32-35, 1906. 

 O. haitensis Maury, Bull. Amer. Pal., vol. 5, p. 346, plate 57, figs. 1, 2, 1917. 



The following is the original description of this species: 

 "Testa oblonga, crassa, plicata, plicis paucis (senis ad septenis), magnis, 

 undulatis, subsquamosis, squamis nonnumquam subtubulosis; limbo interno 

 omnino glabro." 



Two forms of this species are known from Cuba. The first is a large, 

 heavy shell with close, acute, angular plicae. The number of plica* is 

 variable; some specimens have 12 or more. The other form, which is 

 probably the young of the same species, is much smaller, usually not 



