188 INTRODUCTION TO CONCHOLOGY. 



range^ and more decided local variety of character^ in con- 

 formity with a greater diversity of soil and climate, inhabit 

 the eastern. The seven tj^ical provinces of distribution 

 are mentioned as Yenezuelan, Brazilian, Chilian, Bolivian, 

 Caucasian, Malayan, and African, among which, such local 

 advantages as are most favourable to the calcifying func- 

 tions of the Bulimij are, abundance of decaying vegetable 

 matter, with an equable temperature of from 80° to 85" in 

 dark, close, humid woods, among shady thickets or in deep 

 ravines, over wliich 



" Looks out the joyless snn. 

 And draws the coihous steam from swampy fens. 

 Where putrefaction into life ferments, 

 And breathes destructive myriads." — Tliomson. 



On sandy plains, and shores of thin calcareous soil, 

 where the vegetation is parched and scanty, or on wide 

 savannahs, Biilimi are distinguished by light and often 

 vividly coloured shells ; in such, on the contrary, as burrow 

 in the earth, the shell is mostly colourless and often of a 

 grassy texture. Their highest range is in intertropical 

 America, and they extend in both hemispheres, according 

 to the parallels of equal temperature laid down by Hum- 



