246 Mr. L. Reeve on the Geographical Distribution of the Bulimi. 



humidity of the atmosphere, and the cold precipitated from the 

 cold antarctic drift current which flows in a northerly direction 

 along the western shores of South America neai'ly to the equator. 

 The effect of moisture and consequent amount of decaying vege- 

 table matter in promoting the formation of shell is curiously 

 illustrated by the presence of a stout richly- coloured species of 

 large size, B. phasianellus, on the rainy border of Peru, where 

 they crawl up the stripped trees in great abundance ; and by the 

 B. Tupacii, dwelling on bushes and garden walls on the Bolivian 

 side of the Andes at an elevation of 9000 feet, which has a ro- 

 bust dark-painted shell similar to those of the lofty Venezuelan 

 type. B. rosaceus, which inhabits a wide range of country, ex- 

 tending from the environs of Valparaiso, near the sea, to Coca- 

 pata in Bolivia, crouches under stones in the sand in the first- 

 named locality, and has a pale smooth calcareous shell. But in 

 the woods of Cocapata, where it lives in more humid situations 

 among the trunks of trees, the shell is larger, stouter, more richly 

 coloui'ed, and with more of epidermis. Thus we have the change 

 which characterizes different species, presented in the same spe- 

 cies under different conditions. Another remarkable instance is 

 pi'esented in B. zebra. This species inhabits an area of Central 

 America enclosing Honduras, Nicaragua, the West Indies, and 

 Pernambuco, reaching to the shores of Peru, and produces a shell 

 varying so much in character according to the physical conditions 

 under which it is formed, that it has been described as several 

 species. The same has occurred with B. regina, which in its 

 range from New Granada and Guayana to Bolivia and the in- 

 terior of Peru, affects a condition partaking in each instance of 

 the local conchological character of the country. 



4. The Bolivian Province. 



From Bolivia and the Argentine Republic about forty Bulimi 

 are described, illustrative of six types. The large Brazilian 

 B. ovatus, living near the coast, is here represented in the heart 

 of the continent, at Santa Cruz, by the gigantic B. maccimus and 

 Valenciennesii, inhabiting the dense forests of the Cordilleras with 

 B. lacunosus and a few other allied forms. Another type with 

 shells of stout growth is represented by B. Tujiacii, thamnoicus, 

 and inca; and an extremely interesting form is presented in 

 B. onca, found by M. D'Orbigny at the bottom of a deep ravine 

 near Tutulima. A few species with delicately painted shells, 

 constituting another group, inhabit the woods in the vicinity of 

 Cochabamba, B. linostoma, xanthostoma, fusoides, &c. ; and a cha- 

 racteristic group with shells of light structure, freely marked but 

 not highly coloured, is typified by B. pcecilus, hygrohyl(eus, mar- 

 marinas, orendes, &c. The ground-burrowing species, with ex- 



