inhabiting the United States. 493 



r " 



bordering on the Ohio river^ and in the western parts of 

 Virginia and Pennsylvania- I have never noticed it in 

 New England nor in the States east of the Alleghany 



F 



mountains. 



Remarks. This shell is frequently confounded with 

 Helix albolahris^ and I have often seen it in Cabinets 

 labelled as a toothed variety of that species. Mr. Say 

 seems to have considered it as such, for a time, but at 

 length was induced to consider it a distinct species, and 

 it is said was about to publish the description, under the 

 present name, in a number of his American Conchology 

 which he was preparing for the press at the time of his 

 decease. It is now generally known in collections by 

 the name which I have adopted. 



Though resembling H. albolabris in many respects, it 

 differs in general aspect, and in many very observable 

 particulars. It is smaller, more convex, and the body 

 whorl is more ventricbse than in that species. The re- * 

 fleeted lip is less flat and broad, and is sometlmies a little 

 grooved. The aperture is more round, and the plane of 

 the mouth, instead of being flattened in the direction of 

 the plane of the base, is much more upright, making a 

 considerable an^^^le with the base of the shell. Attention 



O 



to these differences will enable one to distinguish the 

 shell, even before the tooth is added. In those indivi- 

 duals where the tooth is wanting there is often a slight 

 deposition of testaceous matter in its place, not distin- 

 guishable without close observation. 



The color of the animal varies in being more or less 

 dark, but I have never seen an individual which approach- 

 ed the white or pearly color, which, after observation of 

 great numbers of H. albolabris^ I have always found be- 

 longing to that species. 



