~~ 
5p) PROCEEDINGS OF THE ACADEMY OF [Feb., 
moderately in front, and is well-rounded on periphery and base, as 
usual. The aperture is large, oblique, rounded, nearly as high as wide. 
Peristome thin, narrowly expanded outwardly, the basal margin a 
trifle reflexed, columellar margin dilated in a curved triangular plate 4 
over about one-third of the umbilicus. Alt. 14, diam. 23mm.; aper- 
ture, alt. 12, diam. 13 mm. 
Bic EmiGRAnt CN. 
— 
pincry 
L HoRsesHoe CA. 
Zz 
“a 
Fig. 2.—Distribution of Sonorella in the Chiricahua Mountains: 1, S. bicipitis; 
2, S. bowiensis (at point of the arrow); 3, S. optata; 4, S. micra; 5, S. virilis 
leucura; 6, S. virilis; 7, S. binneyi. Large areas between 1 and 2 and between 
3 and 4 are unexplored. 
