AIR-BREATHING SXAILS AND SLUGS 273 



with l)rown stripes. \^eiy many of the varieties have 

 received names, such as cooperi^ he//i pliilli^ (jouJdi^ 

 castanea^ anci multicostata^ but it would be out of 

 phice in this small volume to attempt to describe 

 them all. It any of my readers have an opportunity 

 to collect and stud}' these snails, they will have a 

 ver}' interesting opportunity to compare the different 

 forms. 



One of the most marked varieties, 

 which we shall even consider as a distinct 

 species, is Oreohelix idahoetisis^ Newc, 

 the Idaho Snail, a view of which is given Fig. 266 

 in Figure 266. The shell is small, 

 strong and white. The whorls are crossed by many 

 blunt ribs. Its diameter is about half an inch. 



Oreohelix elrodi^ Pilsbry, Elrod's Snail, is another 

 of this series, and is found in the Mission Mountains 

 of Montana. The last whorl of this shell has an acute, 

 peripheral keel, for which reason it is believed by 

 some to be identical with the California species, 

 JL pi phragmo phora circumcarinata. Figure 269. The 

 shell is nearly an inch across. 



FatuJa solitaria^ Say, the Solitary Snail, is essen- 

 tially an eastern species, being particularly abundant 

 near the Ohio River. Nevertheless it is founci in 

 Idaho, Oregon and Washington. The shell is low, 

 and has five whorls, a large, circular umbilicus, and 

 a sharp outer lip. It is of a yellowish brown color, 

 and the whorls are banded with two dark brown 

 stripes with a lighter one between them. Its diame- 

 ter is three-fourths of an inch or more. 



Functuin conspectunu Bland, is the Dial Dot- 



