HELIX. 203 



SHELL very minute, conic, apex obtuse ; epidermis 

 brownish horn-color ; suture well impressed ; whorls six, 

 with conspicuous, elevated, obtuse, equidistant, oblique 

 ribs ; lip thickened, somewhat reflected ; columella with 

 a long, lamelliform, raised line, or tooth, which appears 

 to revolve within the shell parallel to the suture, and 

 sometimes a second, nearer to the base, less conspicuous, 

 and terminating farther within the aperture ; base flat ; 

 umbilicus small, impressed. 



Greatest transverse diameter one-tenth of an inch. 



GEOGRAPHICAL DISTRIBUTION. Inhabits a very wide 

 range of territory ; was noticed by Mr. Say in Missouri ; 

 is found in the Northern, Eastern, Middle, and Western 

 States, also in Mississippi, Arkansas, and Texas. 



REMARKS. This species is of about the same size as 

 //. rupestriSj Draparnaud, of Europe. It is very remark- 

 able for the raised parallel laminae which revolve within 

 the shell, terminating abruptly on the columella. Usually 

 but one of them is apparent. When both are visible, 

 their parallel arrangement bears some resemblance to 

 the track of a railroad. The oblique striae on the 

 whorls are very conspicuous. It varies much in the 

 height of the spire, some specimens being very much 

 flattened, others with a pointed apex ; usually the spire 

 is high and rounded at the apex. The aperture is 

 moderate, not dilated, often delicately roseate, and some- 

 times reddish brown. Found in forests in the interstices 

 of decaying logs, and under layers of wet leaves. 



