VITRINELLA. Panama Shells. 189 



Mean divergence about 170°; greatest breadth .062 inch; 

 least breadth .053 inch ; height .82 inch. 



Station. — Unknown. 



Habitat. — Panama; C.B. A. I 



1 specimen was found in the calcareous sand. 



268. Titrinella tricarinata. Nor. sp. 



Shell subdiscoidal : white : with three prominent spiral keels, 

 one on the periphery of the last whorl, and one on each side of 

 it, of which the upper one is visible on the spire : with some 

 irregular transverse striae : spirally striate within the umbilicus: 

 apex subacute: spire convex, a little elevated: whorls three, 

 depressed above and compressed below the keel, with a distinct 

 suture; aperture oblique, orbicular, angulated by the keels: 

 umbilicus wide and deep. 



Mean divergence about 150" ; greatest breadth .072 inch; 

 least breadth .065 inch; height .035 inch; 



Station. — Unknown. 



Habitat. — Panama ; 0. B. A. I 



1 specimen was found in the calcareous sand. 



269. Titrinella TalTatoides. Nov. sp. 



Shell discoidal : whitish, sub-transparent : last whorl with a 

 prominent keel above, which is visible on the spire, with 

 another prominent keel beneath, and a third, less developed, 

 around the umbilicus : spire concave : whorls three, concave 

 above the keel, with a distinct suture : last whorl subangular at 

 the periphery : umbilicus wide and deep. 



Greatest breadth .1 inch ; least breadth .075 inch ; height .04 

 inch. 



Station. — Unknown. 



JULY, 1852. 48 Auk. Ltc. Nat. Hibt. 



