TO GEOLOGY. 141 



somewhat flattened at the top ; umbilicus none ; mouth 

 ovate ; columella with three folds. 



Length .... Breadth .2, of an inch. 



Observations. A single imperfect specimen only having 

 come into my possession, I am unable to give a full descrip 

 tion of it. The spire and outer lip are both removed. Its 

 folds are rather larger than those described above, and it 

 differs in having three folds on the columella. 



C. elevata. Plate 5. Fig. 139. 



Description. Shell elevated, turrited, cancellate ; sub 

 stance of the shell rather thin ; whorls seven, convex ; 

 suture impressed ; umbilicus none ; mouth ovate, one 

 third the length of the shell ; columella with two folds ; 

 outer lip striate within. 



Length 9-20ths, Breadth .2, of an inch. 



Observations. This pretty little species is remarkably 

 elevated in the spire and beautifully cancellate. A single 

 specimen only w r as obtained, the outer lip of which is 

 broken. It may be easily distinguished by its elevated 

 spire and cancellate exterior. 



C. costata. Plate 5. Fig. 140. 



Description. Shell rather elevated, turrited, with large, 

 sharp, longitudinal ribs ; substance of the shell rather thin ; 

 whorls five, subangular and somewhat flattened at the 

 top ; umbilicus none ; mouth ovate, rather narrow, about 



