﻿AMERICAN TERTIARY AND CRETACEOUS FOSSILS. 395 



anterior ; cardinal margin curved, anterior slightly sinuate, basal and posterior regu- 

 larly rounded ; surface marked by about eight large transverse ribs and numerous 

 smaller ones ; lunule small, deep. 

 Dimensions.— Length 45 in., width *2 in., height of valve *03 in. 

 Locality. — Ripley Group, Eufala, Ala. My collection. 



CRASSATELLA, Lam. 



C. pteropsis. PI. 68, fig. 28. Subtriangular, flattened ; beaks very small; in some 

 specimens a slight depression in advance of the umbonal ridge, which is rounded ; 

 surface marked by heavy transverse ribs, which become faint on and behind the 

 umbonal ridge ; hinge rather small ; muscular scars deeply impressed ; cardinal 

 margin straight, anterior margin regularly rounded, basal margin slightly sinuous, 

 posterior subangular. 



Dimensions. — Length *9 in., width 1*4 in., height of valve '2 in. 



Locality — Ripley Group, Hardeman Co., Tenn., Prof. Safford ; and from the same 

 formation at Eufala, Ala. Collection of the Smithsonian Institution, No. 553. 



CARDITA, Brag. 



C. subquadrata ? Gahb. Prof. Safford sent me, with the other species, several 

 fragments of specimens, which must have been at least two inches in diameter. They 

 are of the same outline, and, as far as I can ascertain, have the same markings as the 

 above species. In the larger specimens the intermediate radiating ribs die out, 

 leaving the ribs of nearly the same shape as C. planicosta of the Eocene formation. 



Locality. — They are from Hardeman Co., Tenn. 



CARDIUM, Linn. 



C. multiradiatum. PI. 68, fig. 29. Subquadrate, equilateral ; beaks small ; surface 

 marked by numerous, fine, radiating ribs of equal size. 



Dimensions. — Length 1 in., width *9 in. 



Locality. — Ripley Group, Eufala, Ala. Collection of the Smithsonian Institution, 

 No. 509. 



This is most probably identical with a cast found abundantly in the brown marl of 

 New Jersey. 



MODIOLA, Lam. 



M. Saffordi. PI. 68, fig. 30. Gibbous, widened posteriorly; beaks small, ante- 

 rior ; umbones very large ; umbonal ridge prominent, rounded, with a rounded furrow 

 anterior to it; cardinal margin nearly straight, posterior margin rounded, anterior 

 wide and regularly rounded, basal sinuous ; surface marked by regular radiating ribs, 



