104 AMERICAN JOURNAL 



DESCRIPTIONS OF NEW SPECIES OF TERTIARY, 



CRETACEOUS, AND RECENT SHELLS. 



t 



BY T. A. CONEAD. 



CKASSATELLID^E. 



CRASSATELLA. 



C. peralta, Conrad. — PI. 8, fig. 1. 



Description. — Subtriangular ; height rather more than the 

 length ; convex ; cardinal margin oblique ; posterior margin 

 widely subtruncated, with a slightly inward slope. 



Locality. — Goshen, Cape May Co., N. J. Mr. Ashmead. 



Observations. — A very perfect ferruginous cast of this species 

 from a new locality, which I suppose to be Miocene, was found 

 in company with the following species, a less perfect cast. 

 They are widely dissimilar to other known species. 



C. planata, Conrad. — PI. 8, fig. -4. 



Description. — Subovate, compressed, anteriorly obliquely 

 truncated inwards ; posteriorly slightly produced ; extremity 

 nearly medial in relation to the height of the shell. (Cast.) 



C. curta, Conrad.— PI. 8, fig. 2. 



Description. — Subtriangular, convex ; rather longer than 

 high ; posterior end truncated, direct; ventral margin rounded 

 in the middle, rectilinear posteriorly ; cardinal plate broad. 



C. curta, Conrad. — Proceed. Acad. Nat. Sciences, 1862, p. 

 578. 



Locality. — Virginia ? 



VENEPJD.E. 



MERCENARIA, Schum. 

 M. obttjsa, Conrad. — PI. 8, fig. 3. 



Description. — Cordate-triangular, very inequilateral, thick 

 and ponderous, ventricose, densely covered with reflexed la- 

 minated concentric lines, and with obsolete radiating lines in 

 the middle of the valves ; posterior end obtusely rounded, the 

 extremity truncated either direct or obliquely inwards ; beaks 

 prominent ; lunale large, cordate, impressed ; inner margin 

 densely crenate ;' anterior cicatrix large and profound. 



