146 HELIX. 



nent, blunt parietal tooth, peristome white, thickened, broad, almost 

 covering the umbilicus, with a large squarely truncated denticle on 

 its right margin and a stout, bluntly pointed one on its base. 

 Diam. 11 mill. 



Kingston, Northern Idaho, 



H. SALMONENSIS, Tryon. PI. 38, figs. 96, 97. 



Umbilicated, thin, shining sparsely hirsute, greenish horn-colored, 

 growth-wrinkles not prominent ; whorls 4 J, hardly convex, the last 

 scarcely descending and deeply grooved behind the peristome, base 

 slightly convex; aperture very oblique, trilobed, with a small parietal 

 tooth, peristome narrow, scarcely reflected, bearing two distant, 

 slightly developed denticles. Diam. 8'5 mill. 



Salmon River, Idaho. 



Described by W. G. Binney as Triodopsis Harfordiana, the 

 specific name preoccupied in the section Polygyra. 



H. BINOMINATA, Tryon. PL 38, figs. 98, 99. 



Imperforate, coarsely, slightly wrinkled, russet colored, sparsely 

 hirsute; whorls 5J, convex, the last globose, slightly descending; 

 aperture very oblique, lunate, with a short, narrow, somewhat 

 curving parietal tooth, peristome white, broad, thickened, revolute, 

 usually quite concealing the umbilicus, bearing on its basal margin 

 an elongated, lamellar, tooth-like process. Diam. 17 mill. 



Kingston, Northern Idaho. 



Described by "W. G. Binney under the preoccupied name of 

 H. Hemphilli. 



H. YUCATANEA, Morelat. PL 30, fig. 13. 



Depressed above, but quite convex below the angular periphery ; 

 whorls 5, obliquely ridged above, striate below, constricted behind 

 the reflected lip; aperture trilobate, parietal tooth very oblique, 

 nearly V-shaped, with a lip tooth opposite, and a smaller erect basal 

 one ; umbilicus rather wide and deep ; light horn ^color. 



Diam. 8 mill. 



Yucatan. 



Subsection II, ISOGNOMONOSTOMA, Fitzinger. 1833. 



H. INFLECTA, Say. PL 30, figs. 14-16, 16a, 16b. 



Whorls 5, minutely obliquely striate, sometimes hirsute, very 

 much contracted behind the lip; aperture trilobate, parietal tooth 

 almost transverse, large and blade-shaped, basal lip tooth a small 



