HABITS AND PROPERTIES. 47 



ities. Possibly, it belongs to tbe genus Pupa rather 

 than to Bulimus. Tlie introduced species Bulimus 

 luiric'Hs is everywhere diffused, but it differs in some 

 respects from the trae Bulimi, and may be considered 

 to be the type of a sub-generic group. Helix is plen- 

 tifully distributed in the whok territory, except in the 

 extreme north and the extreme south ; the difference in 

 the two stations being, that each species declines numer- 

 ically in the north, while at the south many of them dis- 

 appear entirely, but are replaced by a smaller number of 

 species, better suited to the chmate. Selix rhodocheila 

 for instance, is exclusively a southern species, and has 

 thus far been met mth only in the southern part of the 

 peninsula of Florida, and the adjacent islands. Still 

 further noi^th, the polygyral Helices prevail, and then 

 appear the great mass of species which occupy nearly 

 the whole area of country up to the Great Lakes. Suc- 

 cinea is everyivhere disseminated, its distribution being 

 as miiversal as its foi-ms are imvarying. It is probably 

 the most universally disseminated genus. Of the distri- 

 bution of the genera and species occupying the country 

 west of the Rocky Mountains, we know but very httle. 



Habits, &c. The manner of life of the Helicidm 

 has been described, in general terms, when ti-eating of 

 the habits of the whole order. They were said to live 

 mostly in the forest, sheltered under the trunks of fallen 

 trees, layers of decaying leaves, stones, or in the soil 

 itself. In these situations they pass the greater part of 



