146. AMERICAN JOURNAL 



EGERIA, Lea. 



E. DONACEA, nob. — pi. 11, fig. 12. 



Description. — Triangular, donaciform, ventricose ; posterior 

 side short, subtruncated at the extremity ; anterior dorsal mar- 

 o-in slightly incurved ; disks minutely radiated ; umbo ventri- 

 cose ; inner margin crenulated. 



Locality. — Claiborne, Alabama. 



VENERID^. 



CYTHERIOPSIS, Conrad. 



Description. — Triangular; hinge composed of two compressed 

 or linear teeth under the apex, and two oblique teeth anterior to 

 them ; in the left valve are four diverging teeth, the posterior 

 one linear; and a lateral pyramidal compressed tooth ante- 

 riorly; cartilage area rugose; pallial line with a shallow, 

 rounded sinus. 



C. Hydaxa, Conrad. 



This very distinct genus has been usually referred to Gra- 

 telovpia, Desmoulins ; but it has one more cardinal tooth in 

 each valve, and a slight pallial sinus, which in Gratehupia is 

 very profound. It is at present represented by this one spe- 

 cies, and peculiar to the Eocene. 



CYCLAS, Klein. 

 C. CLAIBORNEXSIS, nob. 



Description. — Suborbicular, compressed, inequilateral; beaks 

 small and acute ; disk with concentric, prominent, numerous 

 lamelliform striiB ; ligament margin straight, oblique ; poste- 

 rior end truncated, or slightly emarginate ; ventral margin 

 profoundly rounded. 



Height 1^ inch. Length 1| inch. 



Locality. — Claiborne, Alabama. 



This shell occurs in the group at the base of Claiborne 

 Bluff, belonging to an older division of the Eocene than the 

 Claiborne group above. The cardinal teeth are prominent, 

 and the pits profound. 



