254 



V*wmS* i RICINULA. 



m 



MUREX NERITOIDEUS. LinrUEUSi 



Mawe's Linn. pi. 26, fig. 1. 



The Ricinulae approximate the Purpura?, yet are suffi- 

 ciently different to constitute a separate genus. They 

 are in general of a small size and oval form ; spire ve- 

 ry little elevated; whorls with tubercles or spines; 

 aperture almost constantly tinged with a violet or pink 

 color; right side with unequal teeth, nearly closing the 

 aperture ; columella with small plaits or unequal teeth, 

 and not plain and smooth, as in the Purpura. Shell 

 tuberculated or with long spines ; opening oval and 

 toothed, the lower part ending in a half canal, recurv- 

 ed towards the back, and notched. The R. digitata is 

 very remarkable for the two long palmated digits at the 

 upper part of the right side of the aperture. They are 

 marine shells, and possess an operculum. 



Ricinula horrida Ricinula digitata 



miticula aspera 



clathrata morus 



arachnoidea mutica 



Ricinula pisolina. 



