HELLX. 85 



been separated. Even now, it embraces a very great 

 number of widely diversified species, furnisliing grounds 

 for numerous subdivisions. Still, there is little difficulty 

 in at once distinguishing the members of this genus 

 from all others, if we except the genus Bulimus, ivith 

 which it seems continuous Dy means of the groups 

 found in the region of the Philipphie Islands. The 

 species inhabiting the United States, however, present 

 no difficulty in this respect. The genus CarocoUa, 

 which has been pretty generally admitted by conchol- 

 ogists, comprising species vnth an acute or carinated 

 periphery, is now restored to Helix. The mere circvun- 

 stance of carination seems not to be a sufficient ground 

 for separation ; for the young of most species, however 

 globular they may become when adult, are generally 

 carinated ; and it does not yet appear that there is any 

 corresponding differences in the structure or habits of the 

 animal. It would not be worth oui* while however, to 

 attempt to enter into detail respecting the diversity and 

 economy of this great genus as it is found over the 

 wide world ; but we wiU confine our remarks to those 

 members of it with which we are specially concerned, 

 namely, to the groups which inhabit the United States ; 

 nor need they be much extended in this place, as we 

 have already dwelt upon the points of principal interest 

 in the history of the snails, m our prehminary remarks 

 on the whole family. 



The snails pass the greater part of their lives under 

 dead leaves and logs, under stones, or burrowing in the 

 VOL. u. 22 



