172 HELICIDJE. 



Chersina of Say, which inhabits Georgia and a consider- 

 able tract of North America- 

 It is the Helix Trochiformis of Montagu. In all 

 probability the adult specimen from which Muller 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 MUller 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. PL VI. f. 10, 11. 



BODY rather long, always capable of being contained 

 within the shell : mantle 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 intersected by the penultimate whorl : outer lip 

 sometimes thin, but more frequently strengthened by an in- 

 ternal rib or reflected, 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, except 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. 



