284 PKOCEEDINGS OF THE ACADEMY OF [Nov.-DeC.^ 



about 7,000 or 8,000 feet, granite or other igneous rock prevailing, 

 and with but a little timber. A few ledges of sharp-pointed limestone, 

 dolomite probably, had no attraction for the snails. The entire 

 region at present is inaccessible except to horsemen and pedestrians 

 and these should carry their own food and shelter. We did, and 

 lived like kings before the war. 



One of us (Ferriss) collected a few days, less than a week, in the 

 Santa Catalinas, Mount Lemon and Soldier Camp, in 1910; again 

 much of the time from May to October in 1913, on the southern 

 slope, around Mount Lemon, Soldier Camp, IVIarble Peak and on the 

 northern mesa, about Brush Corral. Again a month was spent in 

 1917, at Sabino Basin, Bear Creek, and Brush Corral, the Rincon 

 Peaks and the Galiuros. The guide, Frank Cole, on a hunting trip, 

 brought in Sonorellas from the Tortillitas and from the Canada del 

 Oro section of the Santa Catalinas. Many inviting prospects in 

 these mountains remain neglected. They surely contain species 

 still unknown. 



Life is rapid in snaildom, decay a slow i^rocess in an arid climate; 

 and possibly these fat cemeteries in the basements of Sonorella 

 slides merely represent the natural death rate of many years. It 

 may be that one living inhabitant to one hundred skeletons is the 

 right proportion. However an impression grows upon the collector 

 as he digs in the arid foothills, that in earlier times there were periods 

 or seasons more favorable to snail life — seasons with more moisture, 

 more vegetation, and a deeper humus. The steep mountain gulches 

 with walls on either side thrown above the surrounding surface quite 

 plainly speak of days when the floods were greater than any known 

 in modern times. These boulder bulwarks contain potsherds and 

 other evidence of human occupation; also Sonorellas. As collecting 

 grounds they are often preferable to the large slides farther up the 

 mountain. Among these boulders, in the hot sunlight, we found 

 the largest Sonorella. Measured crudely in the field it had a diameter 

 of 33 millimeters. 



In collecting Sonorellas and Oreohelices from arid to humid zones 

 in the same canj^on or mountain, one gets the impression that the 

 differences of size are mainly a matter of the breed; that they are 

 racial, rather than due to length of growing season, supply of food or 

 climatic comforts. We naturally search ideal environments of 

 food, shade and shelter for robust races, and expect to meet the 

 pigmy forms in hot, dry and barren places. Often what we find is 

 the reverse of this. On one climb in 1918, at Kitt's Peak, a large 



