112 THE NAUTILUS. 



Upon the slopes of the mountains of southern Arizona and 

 New Mexico and the knobs and peaks of the desert this specific 

 development is intensified, and it is but a short distance from 

 one species of Sonorella to another. Of the four leading genera 

 of this region, the Sonorellas are best fitted to cope with the 

 drouths and the woodchoppers. If it is limestone country, the 

 Holospiras are tenacious. Both are found in very hot and dry 

 rocks, doing fairly well. Sonorellas, two alive, were found 

 near Castle Rock upon the homeward journey. Other promis- 

 ing prospects were left for another season. This Sonorella fam- 

 ily follows the mountains down to 3,000 feet in Arizona. Nearly 

 every little hill in Pima count} 7 , Arizona, has its own species of 

 Sonorella. 



Returning to our subject, the Mogollons, two side trips were 

 made into the mountains on foot from Glenwood, New Mexico. 

 In the Little Whitewater canyon one of the smallest of Ash- 

 munellas was obtained. A two-days journey in the Cave Creek 

 Canyon secured a larger Ashmunella and Oreohelix barbata, in 

 large quantities. One juvenile of the larger Oreohelix only came 

 to the net. 



Another journey of two days was taken up the Dry Canyon, 

 six miles south of Glenwood. Six miles up the Valley a 

 camp was made. Here the precipices boxed in the stream so 

 completely the canyon was not scarred by man or cattle, the 

 stream was full of pound trout, and the slides full of snails. 



The Glenwood Ashmunellas had teeth upon the lip, but no 

 lamella or tooth upon the parietal wall. One species measured 

 ten mm. in diameter, the other twelve to fourteen and one-half. 

 In the Dry Creek canyon, measurements ran from ten to sixteen 

 mm. and as to teeth, ran the scale from none to three and a 

 lamella. In twenty colonies there were about as many varia- 

 tions in species and forms, and in some colonies, as with Ash- 

 munella heterondon. Pils., all variations in teeth existed. 

 Oreohelix barbata varied still more in size and form, with some 

 liberality in color. 



Ashmunella mogollensis came in about six miles above camp, 

 and here the vegetation was so luxuriant that Ashmunellas were 

 found in the weeds they slept in. The miner who owned the 



