270 calyptrj:id^. 



Oeims L.EPETA, Gray. 1840. 



Shell obovate, depressly conical, surface with radiating striae ; 

 apex eccentric, posterior ; aperture oval, muscular impression liorse- 

 shoe-shaped, open anteriorly. Animal blind. 



Lepeta caeca. 



Shell small, white, with numerous diverging ribs, checked by revolving lines, 

 apex central. 



Leppta caca (PatpUa), Muller, &c. ; Stimpson, Check Lists, 4. 



Puttlla Candida, Couthouy, Sillim. Journ. o. s. xxxiv. 217 (18.38) ; Bost. Journ. Nat. 



Hist. ii. 86, pi. 3, fig. 17. — Gould, Inv. 1st ed. 152. — De Kay, N. Y. Moll. 61. 

 Pilidiiim candidum, Stimpson, Shells of New England, 29. 



Shell small, conical, white, oval, having numerous minute radi- 

 ating ribs, traversed by equally fine concentric lines, which give the 

 surface, when viewed under a magnifier, the appearance of 

 F'E.53i. j^gi^^Qj^ij; . summit nearly central, margin slightly scalloped 

 by the termination of the ribs ; interior white. Length, 

 seven twentieths of an inch ; height, one tenth of an incli ; 

 _ breadth, one fifth of an inch. 



Only three specimens of this shell are yet known. The 

 first one found was taken by Mr. Couthouy from the stomach of a 

 fish caught off Barnstal)le, and was described by him. A second 

 has since been found l:)y Mr. W. W. Whieldon, of Charlestown. It 

 is at once distinguished by its checkered or granulated surface, no 

 other species, yet described, having that character. 

 Greenland (^Mailer'). 



Family CALYPTR^ID^E, Beod. 



Shell basin-shaped, serving as a cover to the animal ; distin- 

 guished from the preceding family by the branchiEe being situated 

 in a peculiar cavity upon the back. 



Genus CREPIDULA, Lam. 1799. 



Shell oval, arched, somewhat boat-shaped, with an imperfect 

 spire pressed against the margin ; cavity partially divided within by 

 a horizontal partition. 



