118 AMERICAN SPECIES OF VERTIGO. 



Length 1.8, diain. 0.9 nun. ; 5y 2 whorls. 



Length 1.7, diam. 0.9 mm. ; fully 5 whorls. 



Arizona : Mt. Miugus, near Jerome, at about 8500 ft., type 

 loc., and on Oak Creek, 40 miles from Jerome, Yavapai Co., 

 Ashmun; Bill Williams Mt., Coconino Co., Ferriss; Graham 

 Mts., and Black River, Graham Co., Ferriss; Dragoon and 

 Chiricahua Mts., Cochise Co., Ferriss & Pilsbry. New Mexico : 

 Grants, Valencia Co., A. & J. Bailey, and Bland, Bernalillo 

 Co., E. H. Ashmun ; on Willow, Whitewater and Silver creeks, 

 Mogollon. Mts., Ferriss & Daniels ; everywhere along the crest 

 of the Black Mts., Ferriss & Pilsbry. 



Vertigo coloradensis arizonensis PILSBRY & VANATTA, Proc. 

 A. N. S. Phila. 1900, p. 604, pi. 23, f. 9. PILSBRY, Nautilus 

 xix, 130 (Grants, N. M.). 



This race, of which large numbers have been studied from 

 many localities, is somewhat narrower than V. coloradensis, 

 and invariably has an angular lamella when adult. The 

 palatal folds are long, and there is no basal or subcolumellar 

 denticle. The penult whorl is usually more coarsely and dis- 

 tinctly striate than the others. 



22c. Vertigo coloradensis inserta. n. subsp. PL 12, figs. 10, 11. 



The shell is similar to V. c. arizonensis in size, shape and 

 sculpture, and in possessing a small angular lamella; but the 

 parietal and columellar lamellae are larger and thicker, and 

 there is a basal fold. 



Length 1.85, diarn. 0.9 mm. ; 5 whorls. 



Length 1.7, diam. 0.9 mm. 



Arizona : many places in the Santa Catalina Mts., the type 

 locality being Bear Wallow; J. H. Ferriss. 



It appears to be of general occurrence in the Santa Cata- 

 linas, the localities being between 8500 and 9500 ft. V. c. 

 arizonensis, which inhabits the same zone in ranges north, west 

 and east, was not found in the Santa Catalinas. One quite 

 short specimen from Rustler Park, high in the Chiricahuas, 

 measuring 1.6 x 0.95 mm. appears to be the same race. 



It differs from V. c. basidens by having an angular lamella. 



