159 



Sup. p. 147. t. 21. /. 3. (young. Walk.t.\.f. 23.J 



White, smooth, glossy, subopaque ; whorls three, 

 round, nearly on a level above ; beneath with a central 

 cavity, round which there are traces under a high mag- 

 nifying power of diverging lines of growth ; aperture 

 circular, with the margin a little reflected. 0,10. Not 

 uncommon from deep water. 



S. DIVISA. F.p. 315. TURBO D. Adams. Lin. T. 

 3. p. 254 White, glossy, subpellucid ; whorls three or 

 four, rounded, nearly on a level above, the lower half of 

 each whorl spirally striated ; beneath, with a large cen- 

 tral patulous cavity exposing the whorls; aperture cir- 

 cular and usually detached from the body-whorl. 0,08, 

 Common in deep water. 



TRIBE. TURBINACEA. 



Turrited or conical; with the aperture oblong or 

 rounded, not expanding, and the margins disunited* 



GENUS. TROCHUS. 



Conical, the spire elevated, sometimes shortened; the 

 periphery angulatedor subangulated often thin and 

 acute ; aperture transversely depressed, the margin* 

 disunited above ; columella arcuated, more or less 

 projecting at the base ; operculated t 



