744 DR. J. E. GRAY ON THE CALYPTR^IDvE. [June 27, 



diately costated ; the internal cavity small, compressed, open to the 

 apex of the shell. 

 Hub. ? 



2. Trelania. 



Shell circular, depressed, conical ; apex nearly central, acute ; 

 nucleus subspiral ; cavity circular, conical, with a narrow lunate deep 

 compressed cup-shaped cavity attached to the inner surface of tlie 

 shell by the apex and one of the sides, rest free ; the edge of the 

 cavity complete and free from the inner surface of the shell. 



Trelania radiata. 



CalyptrcBa radiata, Brod. 



Shell brown-rayed, with numerous narrow, close, regular, radiating 

 striae. 



Hab. California. 



** Cup-shaped appendage large, broad, triangular. 

 "Cup-and-Saucer Limpets." 



1. Catillina. 



Shell oblong, conical, radiately ribbed ; the apex acute, subcentral, 

 recurved ; nucleus regular, spiral, of one whorl and a half; the cavity 

 conical, with a broad trigonal cup on the left side under, but not 

 extending to, the apex of the cavity, filled with a callous deposit at 

 the tip ; the part of the cup next to the inner surface of the shell 

 scarcely thickened and not raised up. 



Catillina pectinata. 



Shell conical, high, solid, thick ; the cup large, open, triangular, 

 with the upper part filled with a thick calcareous deposit. 



Calyptraa pectinata, Carpenter. 



C. concamerata. Reeve. (Chenu, Man. f. 2337, 2339.) 



Hab. ? 



Very like a small Crucibulum scutellatum. The upper part of the 

 cup is always partly filled up by a calcareous deposit, and the edge 

 of the cavity next to the inner surface of the shell is not thickened 

 or raised. 



2. DisPOTEA, Adams. 

 " Culypeopsis, Lesson." 



Shell circular, conical ; the apex acute, posterior, recurved consider- 

 ably above the edge ; nucleus subspiral, lateral ; the cavity conical ; 

 apex subspiral, with a broad large trigonal cup-like cavity under the 

 apex, attached to the cavity by one of its sides, the edge of which is 

 not raised or thickened ; the outer or right lip of the cup straight, 

 spreading, cavity open to the tip. 



This chiefly differs from the former genus in the inner lip not 

 being reflexed over the cavity of the cup. 



