1915. J NATURAL SCIENCES OF PHILADELPHIA. 41 L 



oblong, contained between seven and eight times in the diameter 

 of the shell. Avellaneous in color, paler around the umbilicus and 

 slightly so on both sides of the chestnut-brown shoulder band. Sur- 

 face glossy, lightly striate, the embryonic shell of If whorls \vith 

 S. hachitana sculpture. 



Whorls 5, slowly widening, the last whorl very broad and capacious,, 

 rather strongly descending to the aperture. The aperture is very 

 large, obhque, the peristome well expanded except near the upper 

 termination; margins converging, joined by a thin callus. 



Alt. 15.7, diam. 28.4 mm.; umbiUcus 3.7 mm.; aperture 16.4 mm. 

 wide, 13.7 high. 



Cababi Mountains (about 75 miles west of Tucson), collected by 

 Frank Cole, March, 1915. Type No. 112,253, A. N. S. P., cotypes 

 in Ferriss collection. 



This is one of the largest species, very much resembling aS. ashmuni 

 Bartsch, from Richinbar, Yavapai Co., which has a slightly smaller 

 aperture. As the localities are several hundred miles apart and 

 separated by the depression of the Gila River, they will probably 

 turn out to be distinct when the genitalia of both are examined; 

 but as no differences which could reasonably be called specific appear 

 in a close comparison of the types, we rank the southern form as a 

 subspecies. 



The nine specimens collected measure 28.4, 27.9, 27.8, 25.5, 24.8, 

 24.6, 24.5, 24, 23.9 mm. diameter, being therefore variable in size. 



Sonorella ashmuni ambigua n. subsp. PL X, figs. 6, 6a, 66. 



The shell is smaher than S. a. capox (diameter 20.9 to 23.4 mm.) 

 with the last whorl widening somewhat less, the aperture more 

 rounded. 



Alt. 13.5, diam. 22.5 mm.; umbilicus 3 mm.; aperture 12.2 mm. 

 wide, 11 high. Whorls 4^. 



Cababi Mountains; No. 112,254 sent with the preceding, but 

 whether collected in the same place is not known. They were 

 taken in March, 1914, by Mr. Frank Cole, Mr. Ferriss' guide in 1913. 



Thirty-two specimens measure as follows in diameter: 20.9, 

 21 (2), 21.1, 21.3 (2), 21.4 (2), 21.5, 21.6 (2), 21.7 (2), 21.8, 22 (5), 

 22.2 (2), 22.3, 22.4, 22.5 (3), 22.6, 22.7, 23, 23.2, 23.3, 23.4. 



We are in some doubt about the status of this form, but it is 

 readily separable from S. a. capax in the series seen. The genitalia 

 when examined will no doubt clear up the uncertainty. 



