BULIMUS. 277 



Length of axis one inch, commonly three-fourths. Dia- 

 meter of last whorl half an inch. 



GEOGRAPHICAL DISTRIBUTION. Inhabits Alabama, 

 where it appears to be abundant. Was noticed by Mr. 

 Say in Missouri, and has been brought from Arkansas, 

 Texas, and Mexico. 



REMARKS. This very pretty species seems to be 

 rather widely distributed, and is very abundant in some 

 places. Mr. Nuttall informed me that its remains lite- 

 rally covered the ground in some localities in Alabama. 

 It varies widely in form, being sometimes elongated and 

 slender, and at others short and ventricose. It is usually 

 thin and somewhat fragile ; but I have specimens from 

 Texas which are thick and heavy, having a considerable 

 testaceous deposit between the colurnellar and external 

 extremities of the lip, and a thickened margin within the 

 lip. The columella is also sometimes strongly folded ; 

 and the umbilicus is more or less closed. The longitu- 

 dinal lines and blotches of darker color are occasioned 

 by the parts of the shell which are transparent. As it 

 grows older, it becomes uniformly opaque and white. 



By some this is supposed to be identical with Bidimus 

 radiatus of Europe. I have never seen a specimen 

 which authorized this opinion in my view ; and the 

 figures of that species everywhere indicate a much less 

 ventricose shell. 



[The large and solid Mexican and Texan specimens, 

 which have been above noticed as varieties, have been 



