A VARYING SPECIES. 1 49 



for whose help in various ways I would express sin- 

 cere thanks. I will not attempt to describe the 

 numerous varieties, but will simply mention by 

 name — Cooperi^ Haydeni^ Newcouibi^ Hemphilli^Gab- 

 biaiia^ IVasatchensis^ Oqiiirrhensis^ Goiildi^ Biiiiieyi^ 

 albofasciata^ castanea^ Utahensis and viiilticostata. 

 In one of Mr. Hemphill's published letters he signifi- 

 cantly remarks, "The field is very large, ^ * ^ 

 and no doubt many more varieties of strigosa are just 

 waiting for the catcher. ' ' 



Helix {Patula) Idahoeiisis^ Newc, I-da-ho-en'-sis, 

 is shown in Fig. 132. Shell small, strong, white. 



Spire elevated, consisting of five whorls, 



which are crossed by many blunt ribs. 



Umbilicus small, aperture nearly circular. 



The shell as a whole is nearly spherical in 

 Fig. 132. shape, its diameter being equal to its height, 

 which is only half an inch. Even this species is now 

 considered as an extreme variety of strigosa. As its 

 name indicates, it is an inhabitant of Idaho, the one 

 from which this figure was drawn coming from the 

 Salmon River mountains. 



Several species of the genus Zonites^ Zo-ni'-tes, 

 now follow in our train of study. They are all small, 

 having spiral shells, usually with rounded whorls and 

 an open umbilicus. 



Zojiites arboreus^ Say, ar-bo'-re-us, has a spire of 

 four or five whorls, so much flattened that the shell 

 appears nearly like a circular disk. Shell smooth, 

 amber-colored, very thin and almost transparent. 

 Diameter somewhat over an eighth of an inch. This 

 species which hides under leaves and among bushes, 

 inhabits all North America. The specimen described 

 was collected at Los Angeles. A variety, Z. Breweri^ 



