1918.] NATURAL SCIENCES OF PHILADELPHIA. 283 



built villages of summer cottages. It is about a full day's journey 

 from Tucson on horseback. A small saw mill furnishes building 

 material for this summer society, for a sanitarium now under con- 

 struction and for the copper mines over the ridge at the foot of Marble 

 Peak. 



Except in the vallej^ of the San Pedro river and the village of 

 Oracle onty a few miners, ranch men and forest rangers are to be 

 found in all this group of ranges. There are more bears and mountain 

 lions than people. 



The southern slopes of the Catalinas, the foot hills and mesas, and 

 the Galiuro and Tortillita ranges are not heavily forested. At best 

 it is low, open woods or desert shrubbery, through which the granite 

 rocks and precipices glisten in the sun. The soil is dry, though 

 often covered with fallen leaves and growing vegetation. A few 

 Sonorellas and some of the smaller snails may be found at all alti- 

 tudes in the rock slides, the talus, on all sides of the mountain, and 

 in any kind of rock, especially smooth and stratified rock; sometimes 

 also under fallen timber, or in small piles of boulders. 



In the dry season, among dry and hot rocks, dead shells will be 

 the rule. Here one must dig a full eight hour day for a live one. 

 We find a two-foot bar of half inch octagonal steel very helpful. 

 The bar should have a two-inch chisel edge flattened out at each end, 

 one of these turned at a right angle like a hoe. It will weigh one and 

 three-quarter pounds; a good digger, a jimmy for rock work, and a 

 helpful staff in steep and rough places. 



Sonorella is something of a rambler, more*so than Ashmunella or 

 Oreohelix, and upon damp days scouts may be met out in the fallen 

 leaves far from their rocky homes. Often single, dead, lie along the 

 trails where there is no shelter in the vicinity for snail kind. In 1913, 

 on the south side of the Santa Catalinas in the dry season, day after 

 day but one or two living Sonorellas were found. It was the same 

 about Brush Corral Ranger Station, on the north side, in the rocky 

 slides of the canyons nearly on a level with the river. In one of 

 these slides of three or more feet in depth, three hundred good 

 "bones" were found but none alive. It was also the same kind of 

 collecting in the Gahuros and the Tortillitas in the winter of 1917-18. 



A small deep slide of "porphyry" or shale, shaded partially with 

 rose bushes, elder or gooseberry bushes, makes an ideal home for the 

 Southwestern snails. 



The Galiuro range, in Graham County, and the Tortillita range, 

 in Pinal County, as yet unsurveyed, seem to have an elevation of 



