OF CONCHOLOGY, 101 



Distinguished by the whorls of the spine suddenly curved in- 

 wards above the suture. 



GADUS, Rang. 



G. OBNUTUS, Conrad. — PI. 9, fig. 18. 



Description. — Slightly curved, gradually tapering above, more 

 suddenly towards the mouth, which is small. 



Locality. — Haddonfield, N. J. 



CARDITAMERA, Conrad. 



C. MACROPLEURA, Conrad. 



Description. — Trapezoidal, ventricose ; large, prominent, flat- 

 tened on the surface, crossed by prominent lines ; ribs 13, grad- 

 ually increasing in size from the anterior extremity to the umbo- 

 nal slope ; the adjoining post-umbonal rib large, but smaller than 

 the umbonal, and between it and the dorsal line are 3 small or 

 slender ribs, the marginal one thickest ; posterior margin ob- 

 liquely truncated ; umbo broad. 



Locality. — Virginia. 



SAXCICAVA, Lam. 

 S. INCITA, Conrad. 



Description. — Trapezoidal, inequilateral, convex, with minute 

 concentric lines ; posterior end obliquely truncated, biangulated ; 

 beaks distant from the anterior margin. 



Locality. — E. shore, Maryland. 



CYPRINOPSIS, Conrad. 



Equivalve ; two anterior cardinal teeth, and one very oblique 

 bifid tooth in the right valve. Pallial line entire. 



Type. — Artemis elUptica, Smith, Journ. Geolog. Soc. vii, pi. 

 15, figs. 2, 3. 



Meretrix ovalis, Gabb, Palseont. Calif. Cretaceous. 



This genus is nearly related to Cyprina, but the two subequal 

 anterior cardinal teeth of the right valve sufiiciently distinguish 

 it. It has also a much narrower posterior tooth, bifid, not tri- 

 lobed or broadly channelled as in Cyprina. 



PAL^OCORBIS, Conrad. 



Equivalve ; hinge with a pit under the beak of the left valve, 

 and an obtuse anterior thick cardinal tooth ; an anterior thick 



