HELIX. 151 



DESCRIPTION. 



Animal -whitisli, head and tentacles slate color ; foot 

 slender, semitransparent, length less than twice the dia- 

 meter of the shell, terminating acutely. Cavity of the 

 tentacles apparent, when taey are retracted, by two dark 

 lines with a white space between. 



Shell sub-globose ; epidermis brownish, or chestnut, 

 covered with numerous, sharp, rigid hairs ; whorls five, 

 rounded ; suture distinct ; aperture contracted, very nar- 

 row, almost closed by an elongated, lamelliform tooth, 

 situated on the pillar-lip, and extending from the centre 

 of the base, withui the junction of the lip with the outer 

 whorl, into the edge of the aperture ; hp narrow, very 

 much depressed, and reflected against the outer whorl, 

 with a deep cleft or fissure near the centre of the inner 

 margin ; umbilicus wholly covered ; base convex. 



Greatest transverse diameter nearly one half of an 

 inch ; ordinary size less than one-fourth. 



Geographical Distribution. Inhabits the Middle, 

 and all the Western States, where it is common, and the 

 New England States more rarely. In Massachusetts it 

 is an uncommon shell. 



Remarks. This is a very peculiar species. The sin- 

 gular abrupt fissure on the inner edge of the lip distin- 

 guishes it from every other, except the three succeedmg 

 species, which bear a slight resemblance to it in this re- 

 spect. It varies in diameter from one-sixth to one-half an 



