248 



white teeth ; base smooth, polished, umbilical region 

 indented. 



Greatest transverse diameter one-fourth of an inch. 



GEOGRAPHICAL DISTRIBUTION. Inhabits Ohio, Mis- 

 souri, and the western parts of Pennsylvania and Vir- 

 ginia. It will probably be found in all the Western 

 States. 



REMARKS. This is a beautiful, as well as a. very dis- 

 tinct species. Its uniform, shining, reddish-brown color 

 is peculiar to it. Its numerous, narrow whorls, increas- 

 ing almost imperceptibly in width from the apex outward, 

 with their very prominent, elevated striae of increase, 

 give it a considerable resemblance on the upper surface 

 to the Polygyra of Say ; but on the base the similarity 

 ceases. The aperture, including the teeth, is very much 

 like that of Helix gularis, Say, but is smaller in propor- 

 tion to the size of the shell ; and the teeth are shorter 

 and less lamellar, while they are equally prominent. The 

 oblique striae, so distinct on the upper surface, cease 

 entirely at an obtuse carina on the upper part of the 

 outer whorl, leaving the base smooth. The base is 

 lighter in color than the upper surface, and is indented 

 at the centre. The umbilicus is nearly, or quite obsolete. 

 The edge of the lip is brown. The whole surface some- 

 times, and the base often, reflects a metallic lustre. 



The teeth within the aperture are in general formed 

 of a single prominent lamina, or tooth-like fold ; but some- 

 times one, or both of them, are bifid, or even trifid. A 



