174 [December, 1S44. 



This species may be distinguished from C. sequorea, by its greater com- 

 parative length, smaller size, and in wanting the strong furrows of that spe- 

 cies. Mr. Ruffin obtained several entire specimens. 



C. liciata. Suboval, thin and fragile, convex-depressed, surface with mi- 

 nute, closely arranged concentric lines ; anterior margin rather acutely 

 rounded ; posterior margin obtusely rounded or subtruncated obliquely out- 

 wards, the extremity rounded ; lunule lanceolate, defined by an obscure line; 

 beaks prominent, and profoundly curved towards the anterior margin. Length 



1 inch. Height _ 8 _ inch. 



° 10 



Locality. Marlbourne, Hanover county, Virginia. Mr. Ruffin. 



This species is related to C. ovata, Rogers, but is more compressed, less 

 dilated posteriorly, the striae more numerous and distinct on the middle of 

 the valves, while the ovata has there only lines of growth. 



C. eversa. Suborbicular or lentiform, ventricose, surface with fine, closely 

 arranged concentric lines ; anterior and posterior extremity rounded ; basal 

 margin profoundly rounded, and forming a regular curve from the extremi- 

 ties ; umbo broad, with a prominent apex ; lunule ovate-acute, marked by a 

 well defined impressed line ; cardinal teeth robust. Length If inch. Height 

 If inch. 



Locality. Marlbourne, Hanover county, Virginia. 



This shell has much the exterior aspect of an Artemis. Mr. Ruffin has 

 one specimen with both valves. It occurs at Marlbourne, the residence of 

 Edmund Ruffin, Esq., who is making important investigations in the Eocene 

 deposits of that locality. He has kindly sent me beautiful specimens of 

 C ardit a plant xosta and Cardium Nicu licit, together" with the new species of 

 Cytherea above described. 



C. pyga. Suboval, ventricose, thick, with closely arranged robust con- 

 centric lines; umbo wide, prominent above; dorsal margin very oblique, 

 rounded ; posterior extremity obtusely and obliquely rounded inwards ; an- 

 terior extremity much narrower than the posterior, and more acutely 

 rounded ; lunule lanceolate, defined by a distinct impressed line ; cardinal 

 teeth robust. Length If inch. Height 1^ inch. 



Locality. Potomac river, Stafford county, Virginia. Mr. BrufF. 



I am indebted to Mr. BrufF, of Washington, for an opportunity to describe 

 this species. The specimen is a right valve, very perfect, and in outline 

 has some resemblance to C. liciata, but is larger, thicker, more ventricose, 

 with much wider umbones, &c. 



Pecten. 



Pecten elixatus. Suborbicular, inferior valve ventricose, with fourteen 

 wide, elevated, rounded ribs, and with concentric wrinkles. Height \\ 

 inches. 



Locality. Near Santee canal, South Carolina. 



Occurs in friable white limestone. 



