FAMILY COLIMACEA, 87 



Bulimus acrutus. 



Genus V. BULIMUS, Scopoli. 



Animal ; slender, bearing a turriculate shell of from eight to nine 

 whorls, mantle not reflected over the shell , head with the upper 

 pair of tentacles rather long, the lower short, foot lanceolate, 

 posteriorly minute, palate, teeth serrated. 



Shell ; minutely umbilicated, turriculate or conically cylindrical, 

 rather thin, variegated or plain horny, whorls eight to nine, 

 moderately convex, striated in the direction parallel with the 

 lines of growth, aperture small, lip mostly dilated over the 

 umbilicus. 



The value of the genus Bulimus rests very much on its geogra- 

 phical limits. The importance hitherto attached to the number 

 of whorls of the shell and to their elongately drawn out mode of 

 convolution is now confirmed by observations made on the habits 

 and distribution of the species. The British species are too few to 

 furnish materials for generalization. Comparing the foreign Bulimi 

 with Helices, it will be found that they are more arboreal in tropical 

 countries, and less numerous and smaller in the temperate and sub- 

 temperate zones. At the Philippine Islands, in JN"ew Granada, at 

 Natal, Brazil, and Bolivia, Bulimus exists of very large size, much 

 surpassing any Helix in dimensions. In Europe, Bulimus is greatly 

 sxirpassed by Helix in size, and the number of species is quite insig- 

 nificant in comparison. The number of Bulimi throughout the 

 globe compared with the Helices (including Zonites) is about one to 

 two. The latest census by Pfeiffer gives Bulimus 1100, Helix 2050. 

 In France, the proportion is one in eight ; in Britain, only one in 

 ten. In the United States there is no Bulimus at aU north of 

 Tennessee, which is fifteen degrees south of Britain geographically, 



