PROSEllPINID^. 



145 



Proserpina among the genera of Helicirtidce, stating, that " pos- 

 sibly it constitutes a peculiar type of organization, which will 

 cause it to become the nucleus of a new family." 



At last Dr. Gray, by observation of the animal of a new spe- 

 cies allied to Carocolla eolina, Duel., has confirmed the family, 

 and proposed to divide it into the two following genera : — 



I. CERES, Gray. 



Shell heliciniform, keeled, upper surface rugose, covered with 

 a periostraca, lower surface with a callous polished coat. Mouth 

 provided with lamellae on both sides. Peristome straight, rather 

 thickened. 



Ceres, Gray in Proc. Zool. Soc. 1856, Apr. 



Pfr. Hon. Auric, p. 168. 

 Carocollse, Helicis, Odontostomatis, Proserpinse, sp., Auct. 



Shell rugose and covered with a periostraca above, smooth 

 and polished and covered with a thin callous coat beneath. 

 Mantle free from the back of the neck, with a thick double- 

 edged collar, the outer edge rather reflexed. The front part of 

 the upper surface of the foot near the axis of the shell is de- 

 pressed into a rather expanded concavity which is lined with an 

 extension of the mantle, having a raised edge near the margin 

 of the concavity. This raised edge is evidently a continuation 

 of the edge of the mantle of the body, sinuated at the columnar 

 and outer upper angle of the mouth of the shell. It is more 

 developed and crumpled up, in the specimens in spirits, on the 

 left side of the concavity ; and there is little doubt, in the living 

 state, that this extension of the mantle is expanded out and 

 deposits the polished callous coat of the under surface of the 

 shell and the callosity over the axis ; hence the larger size of the 

 left side of the extension. 



Fig. 2. 



x 3 



jT^mffi 



Pffytf^S 



Teeth of Ceres Salleana : o, central tooth. 



Lingual membran? of Ceres Salleana broadj elongate, with 



