OF THE SOUTHERN ATLANTIC STATES. Ill 



A. protexta. Oblongo-elliptical, compressed, with minute raised 

 puiicta ; basal margin straight ; apex prominent, about one fourth 

 the length of the valve from the posterior extremity ; posterior side 

 shghtly reflected ; lateral teeth none. Length, seven eighths inch. 



A. nuculoidcs. Ovate, convex, with very regular, minute concen- 

 tric lines ; anterior extremity acutely rounded ; beaks near the 

 posterior extremity ; basal margin arcuate ; lateral teeth obsolete. 



CARDITA. 



Cardita perjjiana. Plate V, fig. 16. Trigonal, nearly flat; ribs 

 about eleven, angular, minutely granulated. 



C abbreviata. Plate V, fig. 17. Trigonal, elevated, convex-de- 

 pressed, ribs about eleven, convex, minutely granulated ; posterior 

 extremity angulated. This and the preceding species belong to the 

 genus Venericardia of Lam. 



NA.TICA. 



Natica Carolimana. Plate V, fig. 18. Obliquely suboval, with 

 obsolete spiral lines ; umbilicus large, with a central rounded, prom- 

 inent, tliick carina ; apex prominent. 



N. jjercallosa. Spire convex-depressed ; surface with fine, obsolete 

 spiral striae, umbilicus closed by a profound callus. Differs from 

 N. dtipliiata in having the umbilicus perfectly concealed, and in the 

 depressed spire. I thmk this species occurs recent on the southern 

 coast. 



INFUNDIBULUM. 



Infundihidum centralis. Obtusely ovate, with fine concentric 

 irregular hnes ; apex central. 



POLYPARIA. 



LUNULITES. 



Lunulites denticulata. Prominently convex ; apex slightly prom- 

 inent ; pores elliptical, arranged in quincunx order, and having 

 slender projecting spines on the inner submargin; base with ramose, 

 minutely granulated lines ; margin denticulated. 



L. depressa. Suboval, convex-depressed ; pores unequal in size 

 and irregular in form ; many of the larger pores filled with a minutely 

 porous plate or diaphragm, solid in the centre ; others denticulated 

 on the inner submargin ; base granulated, and with very numerous 

 minute ramose strise, slightly impressed ; margin denticulated. 



