264 HELICID^. 



species. In North America tlie species are few in 

 number, and the typical Bulimi are confined to its most 

 southerly portion, none of them extending farther north 

 than Tennessee ; and the species found in Florida and 

 Texas are also common to the neighboring West India 

 Islands, and to the more southerly ISIexican territoi-y. It 

 is only the aberrant forms that are found in the Middle 

 and Northern States. 



Remarks. The genus Bulimus was originally pro- 

 posed by Scopoli, in 1777. As instituted by him, it 

 applied, for the most part, to aquatic shells ; and as after- 

 wards employed by Bruguiere, it included shells which, 

 though alhed in form, were widely different in their 

 natural affinities. One after another, new and well char- 

 acterized genera were withdrawn from it ; until, under 

 the judicious restrictions applied by Lamarck, it was left 

 in such a condition as to be adopted, in the main, by 

 most subsequent naturalists. But simplification did not 

 stop here. The genus, as then left, was made up of spe- 

 cies which varied so little in external characters, whether 

 of the shell or the animal, from those of the genus 

 Hehx proper, — or, when they were so different from the 

 typical form of that genus as to appear widely distinct 

 at first sight, they were found to be connected by such 

 an unbroken series of intermediate forms, — that some 

 authors gave up the division, and united both the Buli- 

 mi, Achatina, and all the other Helicid£e, under the 

 single genus Helix. Such was the course of F^russac, 

 who, in his great work on the Mollusca, made only 



