1915.] 



NATURAL SCIENCES OF PHILADELPHIA. 



391 



colonies were found near by. Our second camp was at the cabin in 

 the saddle at the head of Agua Caliente Canyon, somewhat above 

 7,000 feet and close to collecting Station 6 of map. There is a good 

 spring. The best collecting is in Walnut Canyon, Station 5, where 

 three species of Sonorella live. From above this camp there is fine 

 timber, but no land shells worth mentioning up to the summit of 

 Mt. Hopkins. Good collecting stations were found in Madera 

 Canyon which would be an excellent place to camp. We also reached 

 the head of Josephine Canyon from this camp. A two-day excursion 

 was made, via Brandt's mining camp, over the 8,500-foct saddle 

 north of Old Baldy, and down Camperel Canyon^ to perhaps 7,000 



1-14 6 7 8 15 



Fig. 3. — Collecting stations in the Santa Rita Mcu:itair.>. Contour interval, 



1000 feet. 



feet. There is fine pine on the top and extending some distance 

 down. Also some huge spruce and hemlock trees. We passed 

 through aspens, then small-leaved maples, to walnuts, in the bed 

 of the canyon. Sonorella clappi occurs here, and a few specimens of 

 a Sonorella (occidentalis) , which we provisionally rank as a subspecies 

 of the Huachucan S. granulatissimo. It will be seen that our work 

 extended nearly across the middle of the highest part of the range 

 in a rather narrow band, the collecting stations being marked on the 

 accompanying tracing simplified from the U. S. G. S. topographic map. 



5 This canyon is not named on the topographic map. On it Stetson's dam is 

 situated, lower down. 



