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 was 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 
