HELIX. 141 



Geographical Distribution. Inhabits all the West- 

 ern and South-western States, and the western part of 

 New York. Dr. GrifBth has noticed it on the Lehigh, 

 in Pennsylvania ; and I have received it from the moun- 

 tains of the Carolinas, Georgia, and Tennessee. 



Remarks. I consider this species not to be well 

 established ; but I retain it in deference to the opinions of 

 conchologists generally, who diflfer from me. The descrip- 

 tion of Mr. Say hardly points out any difference between 

 it and the preceding ; and accordingly, varieties of H. 

 2}all{ata are commonly seen in cabinets as H. appressa. 

 Well marked specimens of the two are very unlike ; but 

 they approach each other by nice, and hardly apprecia- 

 ble shades of difference, until they at length seem to 

 blend into one. It is impossible to say how far the 

 characters of shells are modified by the accident of their 

 locahty and other causes ; but that they are so to a con- 

 siderable degree is certain ; and it appears to me that 

 the differences between this and the preceding species 

 are not greater than might be produced by the influence 

 of external circumstances. The shell intended to be 

 described is very common in the Western and South- 

 western States, is usually only about half as large as H. 

 palUata, and considerably more flattened in shape. It 

 has a smooth and shining epidermis, without the hirsute 

 projections, and is finely striated, and sometimes carinate. 

 The lip is narrower and less broadly expanded, the aper- 

 ture much less contracted, and the tooth on the pillar-hp 

 VOL. II. 36 



