50 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 
orella, S. ambigua, was found in the low hills, but not beyond there. 
It is one of the wide-ranging snails, found also far southward, on 
the Mexican boundary, and extending west of any other Sonorella. 
Sonorellas were the only large species obtained from Tucson to 
Ajo. Chaenaxis and Thysanophora hornii were common, but 
other small shells few in number. Desert Sonorellas, large as they 
are, give the pursuer a hard race. In dry weather they retire to 
the deepest regions of their talus world, and to the farthest corners, 
and stay there in cool weather, wet or dry. Only a steady down- 
pour on a warm day awakens long sleep and the attachment to 
smooth stones. But in numerous instances Sonorella has been sur- 
prised in the world above, in rainy weather, wandering among the 
fresh vegetation and fallen leaves. There again they are discovered 
with much difficulty. In the egg-laying periods they often 
gather plentifully among stones near fresh vegetation at the lower 
edge of the slide. In some instances they seemed to herd their 
young. Perhaps but a few times in their history do they partake 
of a square meal. And, where is their harvest field, in the stone 
pile, or in the vegetation above? 
Ajo is now one of the great mining centers of Arizona, and at the 
time of our visit was but a little over a year old in this reputation, 
though an old camp in the history of the state. The prospect of 
novelty and entertainment was pleasing, but the snailing proved 
disheartening. Later, information was gathered that a colony of 
shells had been seen in the Big Ajo Mountains southward, at a 
walnut grove and spring. Also that there were shells in the 
Mesquite Range on the Mexican border. The large Growler Range 
west of Ajo city looked promising from a distance, but the Mexican 
bandits were active at that time along the western boundary. 
There were also hills of promise on the road back. The Pisenomo 
route Tucsonward was taken, and shells found in the south end of 
the Quijotoa Range, and in the southern foot hills of the Cababi 
Range. Again Sonorella ambigua; also Chenaxis, and various 
Pupillide. 
Sonorellas have a wide range in station, from decaying logs in the 
deep moist woods of the Catalinas, to the hot side of dry desert 
hills. At our camp near the Palo Alto Cattle Company’s ranch 
house, at the foot of Kitt’s Peak, a small desert hill not over fifty 
feet high sheltered a colony of Sonorellas. Near the summit of 
Kitt’s peak a colony of small Sonorellas, S. xanthenes, had chosen 
