112 OXYSTYLA, MEXICO, ETC. 



b. Varices few, gray ; apex and peristome white ; no bands ; 

 surface plicatulate leucochilus, p. 129 



b l . Varices few, blackish, the peristome also dark. 



tricincta, p. 120 



ft 2 . Varices numerous, several on the last whorl, and blackish 

 like the peristome ; bands 0-2. melanocheilus, p. 122 



a 1 . Shell rather thin, with longitudinal stripes in addition to vari- 

 ceal streaks. 



ft. Varices few, narrow, 1 or 2 on the whole shell. 



c. Last whorl without spiral bands ; stripes 2- or 3-forked 

 above, widening into broad blotches above the peri- 

 phery ; last whorl large. princeps, p. 113 



zonifera, p. 123 



c 1 . Similarly blotched, but with 2 obscure bands below ; 



form more slender and acuminate. livens, p. 118 



c 2 . Last whorl with thrice angulated narrow continuous 



stripes. crossei, p. 116 



trifracta, p. 115 uhdeana, p. 129 



c 3 . Last whorl with a peripheral band of oblong blackish, 

 alternating with buff spots ; mottled ; 2 narrow bands 

 on spire ; shell large, with long, straight columella. 



deceptor, p. 116 



c*. Last whorl with simple, rarely forked or zigzag brown 



stripes, crossed by three spiral bands, ferussaci, p. 119 



c 5 . Last whorl with a light zone below the suture and 



another around the base, the wide intervening belt 



darker, with wider stripes. zonifera, p. 123 



c 6 . Shell large, with close, pale violaceous nearly straight 



stripes, and few varices. livida, p. 124 



ft 1 . Varices 1-4, narrow, a perceptibly paler zone on the 



closely streaked shell below the suture. zonifera, p. 1 23 



a 2 . Shell solid and strong with longitudinal stripes or spots, and 



varices. 



ft 2 . Varices rather wide, the lip very broadly dark-bordered 

 inside ; shell heavy and thick, boldly striped above, gener- 

 ally becoming rich reddish-brown on the last whorl. 



ponderosa, p. 130 



ft 3 . Varices usually 4 to 6, wide and prominent ; lip generally 

 rather broadly dark-bordered; usually a white subsutural 

 band ; shell solid. 



