298 



SHELLS AND SHELL-FISH. 



PART II. 



short ; the base truncate and emarginate, or with a 

 short recurved channel ; inner lip toothed or plaited.* 



Harpa Lam. Varices numerous and regular^ forming 

 longitudinal ribs, coronated near the suture ; aperture 

 and lips highly polished ; base truncate {fig. Q5. b^c). 

 muhicostata. Sow. Gen. f.l. crenata Sw. Bligh, Cat. 



CypRiECASsis Stuclibury. Shell oblong, oval, ventri- 

 cose, without varices ; spire very small ; aperture 

 cypraeiform ; outer lip thickened, convex, and ad- 

 vancing on the spire ; inner margin regularly toothed ; 

 inner lip thickened, convex, and spreading on the 

 body-whorl, without being detached ; pillar angu- 

 lated internally, and crossed by uniformly slender 

 plaits ; canal very short, reposing on the body- whorl; 

 aperture very narrow, with a recurved channel above. 



testiculus. Mart. f. 375. ? crumena. Mart. 37. f. 379. 



rufa. lb. 32. f. .341. harpjBformis. Lam. No. 26.t 



Cassis Lam, Shell ponderous, marked with varices ; 



out any varices. There is, in fact, every modification of shape among the 

 Tritons as they now stand ; some have the aperture wide, others narrow: 

 the channel is either very long or truncate ; the spire greatly lengtliened 

 or greatly depressed ; the pillar toothed or smooth ; the varices cither alter- 

 nate or none. But, the suh-genera not having been determined, I leave 



the group in this confused state. These facts, better than any theoretical 

 arguments, show the absolute necessity of defining the sub-genera. 



* Except in Dolium and Harpa. 



f Uniting this genus to Harpa. 



