October, 1843.] 307 



LuCINA. 



L. multlstriata. Oval, equilateral, slightly ventricose, with fine prominent 

 closely arranged concentric and minute radiating lines; disk with two or more 

 distinct undulations on the inferior half; beaks prominent ; dorsal margins 

 profoundly declining ; anterior lateral tooth distinct, remote ; inner margin 

 minutely crenulated; lunule elliptical, slightly impressed. Height one-third of 

 an inch. 



Locality. Wilmington, N. C. 



Amphidesma. 



A. asquata. Longitudinally oval, convex, with about 17 laminated concentric 

 stria?; anterior and posterior margins nearly equally rounded ; basal margin 

 very regularly rounded ; beaks slightly prominent ; one cardinal tooth in the 

 right valve, and no lateral teeth. Length less than one-third of an inch. 



Localities. St. Mary's Co., (Md.) Wilmington, N. C. 



Crassatella. 



C. turgidula. Oblong-ovate, slightly ventricose ; surface with coarse lines 

 of growth, and concentric undulations obsolete except on the umbones where 

 they are strongly marked and wide ; beaks submedial ; umbones flattened ; 

 anterior dorsal margin straight ; posterior extremity truncated and nearly direct, 

 more oblique in young shells; basal margin swelling a little anteriorly, posterior- 

 ly straight to the extremity which is obliquely angulated. 



Locality. Calvert Co., Md. 



Allied to C. Marylandica, but has less prominent, more flattened umbones, 

 which are widely and profoundly undulated. It is, also, more ventricose, and 

 has a more regularly arched basal margin. Young shells of the two species 

 are widely unlike each other. 



Crepidula. 



C. splnosa. Oval, ventricose, rather thick, with longitudinal rib-like series 

 of thick, elevated, foliated, erect spines, and coarse transverse wrinkles ; dia- 

 phragm sinuous, the margin profoundly sinuous. 



Locality. James River, near Smithfield, Va. 



Differs from C. cosiata, Morton, in wanting the numerous fine costfc, and in 

 having fewer, much longer, and thicker spines. 



Fulgtjr. 



F. rugosus. Pyriform, with rather coarse rugose revolving lines, disposed to 

 alternate in size, and very distinct numerous lines of growth ; whorls scalariform, 

 with a tubcrculated carina, the margin of which presents a waved outline, the 

 tubercles being obtuse ; spire prominent, profoundly channelled at the suture, 

 the margin of the channel carinated in young shells. Length 3 inches. 



Locality. St. Mary's River, Md. 



Compared with F. coronatus, this species, when adult, is comparatively 

 shorter and more inflated, with a shorter spire, much coarser revolving lines, 

 which with the more numerous, more obtuse tubercles, give the shell a very 

 different appearance from the coronatus. In an adult specimen of the latter 

 species there are 13 spiniform tubercles on the body whorl. In the allied species 



42 



