LEVEXIA. 217 



Genus CASSIDEA, Link. 



Mantle -margins reflexed over the lips of the shell. 



Operculum none. 



Shell oval; spire short; aperture straight, narrow, chan- 

 nelled posteriorly; columella toothed; outer lip involute, 

 toothed ; varices none, or obsolete. 



Syn, Cyprsecassis, Stutch. 



Ex. C. testiculus, Linncpus, pi. 23, fig. 3. 



Cassidea resembles Moruifi, but the shell is not cancel- 

 lated ; the lobes of the mantle are expanded, and, accord- 

 ing to Stutchhury, cover both lips of the shell; the foot is 

 destitute of operculum; the inner lip is spreading, but the 

 margin is not free, as in Cassis, and the columella is 

 transversely plicate, as in Cyprcea. 



Species of Cassidea. 



rufa, Linn. testiculus, Linn. 



tenuis, Wood. 



Genus LEVENIA, Gray. 



Operculum narrow, the nucleus on the middle of the 

 straight edge. 



Shell ovately-subcylindrical ; spire conical, whorls no- 

 dulous, the penultimate distorted and gibbous; aperture 

 narrow, contracted in the middle; inner lip moderate, pli- 

 cated ; outer lip thin, not reflexed, internally plicated. 



Syn. Cassis sp., Sow. 



Ex. L. coarctata, Sotverby, pi. 23, fig. 4. Opercukiraj 

 L. coarctata, fig. 4, «, 4, b. 



VOL. I. F F 



