243 Mr. L. Beeve on the Geographical Distribution of the Bullmi. 



different degrees of temperature, it may be remarked tbat the 

 calcifying energies of the Bulimi are most strongly exerted 

 in thickly wooded districts, in the midst of plenty of decaying 

 vegetable matter, close and humid, with a mean heat of from 

 80° to 85°, among shady thickets or in ravines. Near the sea- 

 level in thin calcareous soil, and in sandy plains, where the vege- 

 tation is scanty and parched, and in grassy savannahs, the shell 

 is thin and often vividly colom-ed. In those species whose habit 

 it is to burrow in the ground, the shell is mostly small, pattern- 

 less, and of glassy tenuity, even in localities remote from each 

 other and differing materially in physical character. 



I. The Western Hemispheke. 



The Western Hemisphere comprises four grand provinces of 

 distribution, the Venezuelan, the Brazilian, the Chilian, and the 

 Bolivian, and from these may be further distinguished the di- 

 stricts of the Gelepagos Islands and of the Great Antilles. The 

 fii-st province includes the countries of New Granada and Ve- 

 nezuela ; the second comprises the empire of Brazil and Buenos 

 Ayres ; the third comprises Chili and West Peru ; and the fourth 

 province includes Bolivia and the Argentine Republic. About 

 three hundi-ed and fifty species are known. 



1. The Venezuelan Province. 



The highest condition of the genus is in intertropical America, 

 which yields about one half of the number of species known from 

 all parts of the world. In the luxuriant districts of New Gra- 

 nada and Venezuela, watered by the tributaries of the Magdalena 

 and Orinoco rivers, with a temperature varying from 70° to 100° 

 in the shade, about sixty species have been collected at different 

 altitudes. On the mountain sides near the sea, away from the 

 land breezes, with little vegetation, where the thermometer never 

 falls below 80°, are a few species, B. erectus, Cacticolus, &c., of 

 which the shell is extremely thin and sombre from the want of 

 moisture for the animal, which is curiously spotted and painted, 

 and attaches in clusters to the parched Cacti, eating into their 

 fleshy substance. The animals of the beautifully variegated 

 shells of the Philippine Bulimi are of a uniform dull gray 

 colour. These contrasts between animal and shell are worth 

 noting. Higher up on the mountains of Venezuela for the space 

 of about 2000 feet, the countiy being still of a sandy and stony 

 nature, with little vegetation except Cacti and other dry prickly 

 shrubs, and a few trees in the ravines, the Bulimi are still com- 

 paratively small, but the shell is more brilliant in colour. B. Cu- 

 rianensis, Knorri, and Studeri are beautiful examplesof this type, 



