PUPA. 325 



tentacles long and slender, slightly curving ; inferior 

 prominent and conical, pellucid at tips. Respiratory 

 foramen visible in the external angle of aperture. 



SHELL sub-conical ; epidermis whitish horn-color ; 

 whorls between five and six, very convex, diminishing 

 regularly from the last whorl, which is somewhat ventri- 

 cose, to the apex ; suture well impressed ; lip white, 

 thickened, somewhat reflected, its extremities connected 

 by a raised, testaceous fold, making the margin of the 

 aperture entire ; aperture lateral, rather triangular or 

 trilobate, more than half as wide as the body whorl, 

 expanded above and diminishing regularly into a very 

 narrow throat, with four teeth, one upon the columella, 

 large, coarse, and irregular, projecting into and very 

 much filling up the aperture, and having a concavity on 

 the side towards the lip ; another tuberculous, not large, 

 more or less near the margin of the lip ; and two others, 

 massive and prominent, deep seated in the throat, one 

 being in the base behind the columellar tooth, and the 

 other on the side of the umbilicus and apparently pro- 

 duced by the umbilical fold ; umbilicus with a minute 

 perforation ; base of the shell with a sharp keel between 

 the umbilicus and margin ; last whorl impressed behind 

 the outer lip. 



Length one-tenth, diameter one-twentieth of an inch. 



GEOGRAPHICAL DISTRIBUTION. Inhabits all the North- 

 ern, Middle, and Western States, also Florida, Louisiana, 



