BULIMUS. 187 



but when this occurs^ very little difference is perceptible 

 among such as inhabit countries that lie far apart. 



We owe to an admirable paper, by Mr. Eeeve, ' On the 

 Geographical Distribution of the Bulimi' the valuable 

 information that the localities of about five hundred species 

 are known, and that the majority are registered, with their 

 circumstances of habitation. This paper, communicated at 

 a meeting of the Royal Society, speaks also on the modi- 

 fication of their calcifying functions, according to the local 

 physical conditions in which the species occur ; and men- 

 tions that their area of geographical distribution lies be- 

 tween 40° south and 35° north, in the New World, and 

 42° south and 60° north, in the Old World— that is, be- 

 tween the southern extremity of Chili and Texas in the 

 former, and between Yan Diemen's Land and Sweden in 

 the latter ; and, further, that within this wide range, no 

 locality, however dissimilar, exists, in which the BuUmi are 

 not found. Little variation occurs with regard to the 

 moUusks themselves, but, as respects distinctions of form, 

 composition, and system of colours, forty typical assem- 

 blages of species are distributed over this area, in seven 

 provinces, of which three-fifths belong to the western 

 hemisphere, and the remaining two-fifths, with a wider 



