124 



are thirteen or fourteen in number, extending from the suture 

 about half the distance to the tip of the beak, and near the suture 

 exhibiting a tendency to rise into arched scales ; the whole surface 

 of this shell is sculptured with small revolving grooves, to the num- 

 ber of from twenty-five to thirty on the body whorl ; inferior 

 moiety of the body whorl tinged with rufous ; suture profoundly 

 impressed ; aperture gradually diminishing to the beak ; striae of 

 the labrum within distinct, sometimes obsolete or wanting. 



Length nine-twentieths ; greatest breadth more than one-fourth 

 of an inch. Inhabits the Southern coast of East Florida. 



The aperture is not suddenly contracted at the origin of the 

 beak channel, as in many species, but is gradually diminished in 

 width, much like Montfort's Q.(^u.xe of Lafirm /ihsus. 



For this shell I am indebted to Mr. Elliott. 



Patella alternata. — Shell conical, with upwards of thirty 

 obsolete, hardly raised, unequal ribs ; apex obliquely curved, the 

 tip pointing nearly in a parallel direction with the surface of the 

 shell, and acute ; color brown, radiated with white ; base oval. 



Basal length three-tenths of an inch. Inhabits the Southern 

 coast of East Florida. 



Communicated by Mr. Elliott. It seems to approach the leti^o- 

 pleura, as described by authors, excepting that the base is not 

 ovate, as the base of that shell is said to be. 



Calyptr^a striata. — Shell oval, prominently convex, with 

 numerous, slightly elevated, equal, equidistant radiating lines ; 

 summit glabrous, wax-yellow, subacute, inclining towards the left 

 side and the posterior end ; inner valve patelliform, dilated, attached 

 by one side to the shorter side of the shell ; acutely angulated at 

 the anterior line of junction, and rounded behind, and rapidly at- 

 tenuated to an acute tip, which nearly corresponds with the inner 

 apex of the shell. 



Length less than nine-tenths of an inch. 



This species belongs to my indicated genus Dispotxa. I am 

 indebted for it to Mr. John S. Phillips, who obtained two speci- 

 mens on the coast of New Jersey, about three miles north of Long 

 Branch. 



Venericardia tridentata. — Shell suborbicular, subequi- 

 lateral, thick and ponderous, with about eighteen convex, longitu- 



