172 HELICIDiE. 



Chersina of Say, which inhabits Georgia and a consider- 

 able tract of North America. 



It is the HelLv Trochiforinis of Montagu. In all 

 probability the adult specimen from which Miiller de- 

 scribed his Helix fulva was the H. edentula of Draparnaud 

 or the H. bidens of Chemnitz, both of which have a white 

 keel and lip, as noticed by Miiller in his description. 

 The last-mentioned species is Scandinavian as well as 

 French, and is closely allied to H. edentula. In the 

 present species neither the keel nor lip is white. 



This species forms a passage to the next genus, Helix. 



Genus IV. HE'LIX*, Linne. PI. VI. f. 10, 11. 



BoDT rather long, always capable of being contained within 

 the shell : manth thick, slightly cloven on the under side : 

 tentacles 4, cylindrical, more or less swollen or bulbous at the 

 tips : foot in most species broad. 



Shell conical, not very glossy : spire usually produced, rarely 

 depressed or flat : mouth forming an oblique segment of a circle, 

 which differs in size according to the degree in which it is in- 

 tersected by the penultimate whorl : oiUer lip sometimes thin, 

 but more frequently strengthened by an internal rib or re- 

 flected, in some cases furnished with tooth-like tubercles 

 which contract the mouth : umbilicus usually distinct and more 

 or less open, but in a few species quite closed or wanting, ex- 

 cept in the young state. 



This genus comprises all the true Snails. They are 

 for the most part vegetarians ; but they occasionally show 

 a preference to animal food, both raw and cooked — being, 

 like Man, omnivorous. Every wood, hedge-bank, old 

 wall, field, and garden yields some kinds; while others 

 frequent mountains, water-sides, open plains, and sand- 

 downs near the sea. Most of them prefer shade and 



* A coil. 



