Y2 AMERICAN JOURNAL 



ASTARTE, Sowerby. 



A. COMPSONEMA, Conrad. — PI. 4, fig. 18. 



Descrii^tion. — Sub-triangular, inequilateral, slightly convex ; 

 ornamented with regular, sub-equal, close, concentric lines, 

 rounded, slightly recurved, between 45 and 50 in number; 

 apex prominent, acute; lunule lanceolate; dorsal margin very 

 oblique, slightly sinuous ; posterior side slightly contracted ; 

 extremity much above the line of the base, and obtuse. 



Locality. — Virginia ? 



This elegant species is more elevated than A. concentrica^ 

 Con., and has more numerous and finer lines ; it differs from 

 A. bella, Con., in having rather larger lines, and in the hinge- 

 plate being much narrower, and the lunule much less exca- 

 vated. The genus is remarkably developed in the American 

 Miocene, 18 species having been described, whilst 4 species 

 only have been obtained from the Eocene, and there are but 

 3 recent species on the Atlantic coast, as far North as Massa- 

 chusetts ; and, except A. castanea, Say, they do not live South 

 of that State. There is a curious blending of tropical or sub- 

 tropical genera in the American Miocene, with forms which 

 are prevalent in Northern latitudes. Thus Gyprsea, (7o??w5and 

 Grassatella lived on the Virginia coast in company with many 

 species of Astarte, of which genus no species has been found 

 even in the Postpliocene of Virginia or Carolina. 



A. DiSTANS, Conrad. — PI. 4, fig. 14. 



Description. — Triangular, convex-depressed, with four broad, 

 concentric undulations; concentric lines unequal; umbo flat- 

 tened, with prominent, small, concentric ribs ; inner margin 

 minutely crenulated. 



A. distans, Conrad. — -Proceed. Acad. Nat. Sciences, 1862, p. 

 288. 



Locality, — Shiloh, Cumberland Co., N. J. 

 A. Thomasii, Conrad.— pi. 4, fig. 16. 



Description. — Triangular, slightly ventricose ; ribs robust, 

 rounded, recurved ; concentric lines minute ; towards the pos- 

 terior end, the ribs become obsolete; posterior extremity sub- 

 truncated nearly direct ; summit prominent ; lunule large, 

 acutely ovate, deeply impressed ; inner margin crenulated. 



A. Thomasii, Conrad.— Proceed. Acad. Nat. Sciences, 1855, 

 p. 267. 



Locality. — Near Mullica Hill, N. J. 



