﻿282 CONRAD'S DESCRIPTIONS OF 



A very thin shell, with a plain surface, only one valve of which is in the Tuomey 

 collection. 



TRIGONIA, Lam. 



Trigonia thoracica, Morton. PL 47, fig. 10. This species occurs among the 

 Tippah fossils found by Dr. Spillman. It has 14 acute or angular, prominent, oblique 

 ribs; umbonal slope angulated or slightly carinated; posterior slope transversely 

 ribbed, ribs linear ; a groove runs obliquely to the extremity of the post umbonal 

 area ; this groove is represented within by a short, distinct rib. 



VENILIA, Morton. 



Venilia trapezoidea. PL 47, fig. 7. Trapezoidal, inequilateral; disk without 

 distinct concentric ridges ; umbonal slope nearly terminal, carinated ; posterior ex- 

 tremity truncated, direct. 



Locality. — Eufaula, Alabama. Tuomey's collection. 



CARDIUM, Lin. 



Subgenus TRAQHYCAKDIUM, March. 



Cardium Eufaulense. PL 46, figri2-. Obliquely ovate, rather thick in substance, 

 profoundly ventricose ; ribs about thirty-eight, smooth, prominent, acutely rounded, 

 on the posterior slope angular, compressed or carinated ; summit prominent; beaks 

 contiguous. 



Locality. — Tippah Co., Mississippi, and Eufaula, Alabama. Tuomey's collection. 



A single small valve of this shell was sent by Dr. Spillman, but specimens as 

 perfect as living shells, except in color, are in Tuomey's collection, one of which is 

 represented in the figure. Among the Cretaceous species of Cardium figured by 

 D'Orbigny there is no representative of the G. Eufaulense. 



CALLISTA, Poll— DIONE, Gray. 



Callista Eufaulensis. PL 46, fig. 24. Suboval or suborbicular, convex ; margins 

 regularly and almost equally rounded ; umbo broad ; summit prominent ; disk with 

 regular concentric impressed lines which do not extend to the base ; anterior cardinal 

 tooth compressed and elongated. 



Locality. — Eufaula, Alabama. Tuomey's collection. 



A single valve only of this thin, fragile species is in Tuomey's collection. 



ASTARTE, Sowerhy. 

 Astarte crenalirata. PL 46, fig. 25. Triangular, convex ; costae about twenty, 

 concentric, very prominent, slightly recurved, crenulated by minute radiating lines ; 

 margin within crenulated, crense rounded on the posterior margin, and the rest 

 tuburculiform. 



