186/.] DR. J. E. GRAY ON THE CALYPTR/EIDjE. 745 



* Cup conical, deep ; shell striated, edge crenated. 



1. DispoTEA STRIATA, Adams. 



Calyptrcea striata, Say ; Chenu, Man. f. 2342. 



Shell circular, radiately costateJ ; costae interrupted by the smooth 

 lilies of growth ; the cup conical, deep ; the right edge straight, even. 

 See D. cancellata, Adams & Reeve. 



** Cup concave, shallow ; shell smooth, edge even. 



2. DiSPOTEA BILOBATA. 



" Calyptrtea bilobata. Gray." 



Shell thin, oblong or ovate, white, brown-rayed, smooth, minutely 

 rugulose, sublaminal ; the cup concave, shallow, the right lip flexu- 

 ous, two-lobed. 



Hab. California. 



2. Crucibulum, Schumacher ; Adams. 



Biconia, Swainson. 



Calyptr apsis, Brod. (not Lesson). 



Dispotea, Say. 



The shell circular, depressed, conical ; apex nearly central, acute ; 

 nucleus subspiral ; cavity circular, conical, with a broad subtrian- 

 gular cup-shaped cavity attached by the upper part of one of its sides, 

 but with the edges free from the cavity of the shell on every side. 



In the young shell the internal cup is imperfect, consisting of a 

 narrow triangular curved subspiral cavity, without any shelly deposit 

 on the inner side of the cup next to the surface of the shell. As the 

 shell enlarges, the width of the side of the cup decreases, and the edge 

 is completed and at length elevated from the inner surface of the shell. 



* The internal cup broad, rather longer than broad. 



1. Crucibulum scutellatum. 



Calyptrcea scutellata. Gray. 



Crucibulum imbricatum, Brod. 



C. umbrella, Desh. (shell very flat). 



C. lignaria, Brod. 



C. corrugutum, P. Carpenter. 



C. ferrugineum. Reeve. 



C. trigonale, Adams & Reeve. 



C. rugosum, Deshayes. 



C. tenuis, Broderip. 



Dispotea spectrum. 



Shell solid, brown (or pale, with brown rays), with broad flat ra- 

 diating and concentric ridges, or more or less smooth and closely 

 radiately striated (Chenu, Man. f. 2332, 2335, 2338). 



Hab. West Coast of America ; Valparaiso ; Chiloe ; Gulf of Cali- 

 fornia. 



Pkoc. Zool. Soc— 1867, No. XLVIII. 



