MARINE MOLLUSCA OF THE UNITED STATES. 121 



Genus STYLIOLA, Lesueur. 

 Blainville, Man. Malacol. 1825. 

 Cressets, Rang.«A.nn. Sci. Nat., xiii. 302. 1828. 

 1. S. vitrea, Yerrill. Fig. 251. 



Am. Journ. Sci., 3d ser. III. 248, t. 6, f. 7. 1872. 

 Shell smooth, polished, diaphanous, almost glassy, long conical, 

 rather slender, slightly curved towards the acute apex. 

 Length 12, diam. 2 mill. 



Animal white ; swimming organs obovate, with the end broadly 

 rounded, and bearing the slender tapering tentacles near the mid- 

 dle of the anterior edge ; intermediate lobe short, rounded in 

 front. 



Martha's Vineyard. 



Family CYMBULTIM2, Gray. 



Syn. Brit. Mus. 1840. 



Genus PSYCHE, Rnng. 



Ann. Sci. Nat., v. 284. 1825. 



1. P. globulosa, Rang. Fig. 252. 

 Ann. Sci. Nat., v. 283. 1825. 

 Body round, diaphanous, mouth slightly arched, fins long, 

 rounded at their extremity, narrowed at their base, with a slight 

 shell-case above ; viscera of a handsome purple, forming an ovoid 

 mass, suspended in the middle of the body. 



St. Pierre and Miquelon. 



Family LIMACINIDJE, Gray. 

 Syn. Brit. Mus. 1840. 



Synojysis of Genera. 

 Shell subglobose, subdiscoidal, sinistral ; spire slightly raised ; the last 

 whorl with an obscure keel ; axis umbilicated, keeled on the edge ; oper- 

 culum ? Limacina, Cuvier. 

 Shell thin, vitreous, discoidal, depressed, sinistral ; axis umbilicated ; 

 whorls smooth ; aperture angulated below or canaliculated, sometimes 

 prolonged into a spine-like curved beak ; operculum glossy, thin, trans- 

 parent, of few whorls, with a central muscular scar. 



Spirialis, Eydoux and Souleyet. 



Genus LIMACINA, Cuvier. 

 Regne Anim., ii. 380. 1817. 



1. L. helictna, Gmelin. Fig. 253. 

 (Clio.) Syst. Nat., 3149. 1790. 

 Shell subglobose, subdiscoidal ; spire slightly raised ; whorls 



