BULIMUS. 289 



and lower parts lighter ; upper tentacles long and slen- 

 der., lower very short. 





 SHELL fusiform, regularly diminishing in volume from 



the body-whorl to the apex, smooth ; epidermis brownish 

 horn-color ; whorls six, very convex, striae of growth 

 hardly apparent ; suture well impressed ; aperture late- 

 ral, rounded oval ; lip white, rather broadly reflected ; 

 umbilicus perforated. 



Length of axis one-fifth of an inch ; diameter of shell 

 one-fifteenth. 



GEOGRAPHICAL DISTRIBUTION. Inhabits the North- 

 ern, Middle, and Western States. It has also been 

 found in South Carolina. 



KEMARKS. This is readily distinguished from the other 

 species by its white, broadly reflected, and flattened lip, 

 which surrounds the whole aperture, except a small 

 portion which is interrupted by the body-whorl. It re- 

 sembles a Cyclostoma, but has a membranous epiphragm. 

 The aperture is entirely destitute of teeth, and opens 

 laterally, or upon the side of the shell, its plane being 

 parallel with the axis of the shell. The umbilicus is dis- 

 tinctly perforated. 



The specific name by which Mr. Say first described 

 this shell being preoccupied in this genus, his second 

 name, applied to a variety, of course takes precedence, 

 and there is no occasion for another. 



VOL. ii. 37 



