312 HELICID^. 



Genus PUPA, Dkaparnaud. 



GENERIC CHAEACTEES. 



Animal small, about twice as long as broad, wide 

 and square in front, slightly tapering and obtusely rounded 

 posteriorly ; beneath, the head is separated from the foot 

 by a transverse line ; the cephalic portion is transverse, 

 more or less lobed in fi-ont ; the locomotive disc is long 

 oval, truncate in front. Tentacles four, the cervical 

 ones oculiferous at tip, the oral ones short and some- 

 times reduced to a minute tubercle. The viscera are 

 remarkable for their great length. 



Shell elongated, cylindrical or acuminate, with nu- 

 merous whorls, the last of which differs but little from 

 the preceding one, having its plane nearly corresponding 

 to the axis of the shell. Aperture sub-circular, or semi- 

 oval, simple or armed with denticles or lamina ; lip sim- 

 ple or reflected ; base perforated by a fissure or circular 

 umbilicus. 



Geographical Distribution. Specimens of this 

 genus have been found over the greater part of the 

 globe. Few are known from Africa or Eastern Asia ; 

 and I am not aware that any one has been found in 

 New Holland. They are numerous in Europe, Western 

 Asia, North America, and the West Indies. Perhaps 

 they may be found equally abundant elsewhere, when 



