HELIX. g9 



States, but they are not everywhere equally abundant ; 

 nor do all the specie§ range over an equal extent of ter- 

 ritory, some of them being nearly omnipresent, while 

 others are quite local. Thus we have H. arborea, thy- 

 roidus, tridentata, and lal\^rintliica over nearly the 

 whole extent of the country ; H. profunda, solitana, 

 intertexta, nmltilineata confined to the States bordering 

 on the great lakes ; H. auriculata, septemvolva, fati- 

 giata, mohiliana, and rhodocheila on the confines of the 

 Gulf of Mexico ; H. sjmiosa, edyariana, and cumher- 

 landica in the region of Tennessee and Georgia ; H. 

 major in Georgia ; and so on with other species and 

 regions. The number of species is smaller at the south 

 than at the north, but the number of individuals is 

 greater. In limestone regions, where the materials for 

 the shell are furnished in abundance, as m Ohio and 

 Western New York, snails may be collected in great 

 numbers ; whereas in the granite regions of New Eng- 

 land, the collection of a small number is so tedious a 

 task, that it would be fortunate to obtain twenty speci- 

 mens of the larger species in a day's seax'ch. 



Remarks. It forms no part of our object to attempt 

 a division of the genus into lesser groups in accordance 

 with natural characters, as the few species on which we 

 are engaged would not afford the basis for such a division. 

 Numerous subdivisions have already been made, founded 

 upon the shell ; but none of them can claim to represent 

 natural series. We doubt not, however, that hereafter, 

 VOL. II. 23 



