GROGRArillCAL DISTRIBTTTION. JI5 



and saturated ^vith water, localities not habitable by 

 other genera. Ildiv multilineata is one of the species 

 said to inhabit wet meadows. 



Elevation. Although all our species, as has been 

 said, may be supposed to have surmounted very consider- 

 able elevations, yet they do not constantly inhabit the 

 highest levels, such positions being, by reason of climatal 

 influences, less favorable to them than less elevated 

 situations. There are, however, some species which, 

 although diffused throughout almost every part of the 

 country, are found more commonly than others, in the 

 higher regions of the mountains, and which appear to 

 occupy them by choice. It would seem, therefore, that 

 elevation exercises an influence independent of climate. 

 We are not aware that many facts have been observed 

 which support this opinion, and the only species which 

 we can mention with confidence as being frequently 

 noticed in such situations is Helix inornata, which, both 

 in New York, Vermont, and Massachusetts, we have 

 procured from the highest ridges. This native species 

 bears some resemblance to Helix alUaria, which Mr. 

 Forbes cites as an inhabitant of the highest elevations 

 in Great Britain. 



But, notwithstanding these remarks, the general influ- 

 ence of elevation corresponds with that of increasing 

 northern latitude, and is decidedly climatal. The height 

 of the most elevated mountains in the United States, 

 eastward of the Rocky Mountams, however, is so incon- 

 siderable, that they enjoy for a short period, at least 



