1910.] NATURAL SCIENCES OF PHILADELPHIA. Ill 



Two examples, extremes of a continuous series, are figured to illus- 

 trate this (fig. 23 c, d), from about the middle of the amphitheatre 

 west of Reed's Mountain. This variation is not peculiar to any special 

 colonies, though greater in some lots than others. 



At the Cave Creek Falls there is a small form. Three specimens 

 measure as follows : 



Alt 8 7 6.7 mm. 



Diam 16 16 13.5 " 



Whorls 5£ 5§ 5£ 



The genitalia of two individuals are figured. PI. X, fig. 4, is from 

 one of the very large shells of the head of Cave Creek at about 8,000 



Fig. 23. — A. chiricahuana (Dall). A, B, Cave Creek Canyon; C, D, amphitheatre 



of Cave Creek. 



feet elevation, near Long Park, diam. 19.5 mm. The ducts are very 

 long in these large snails. Both penis and spermatheca adhere to 

 the uterus throughout part of their length, the penis looping under the 

 spermatheca. The vagina is stout down to its base. PI. X, fig. 1 , was 

 drawn from one of the very small shells of the Cave Creek Falls, diam. 

 13.5 to 16 mm. The ducts are shorter and the base of the vagina is 

 thin-walled. The penial retractor is longer in this species than in 

 the toothed species, but not so long as in the Huachucan Ashmunellas. 

 The collar and foot are slate-colored; mantle-lining of the last whorl 

 cream-white, not maculate. 



