THE NAUTILUS. Ill 



Turning south and eastward from Mogollon, the larger Oreo- 

 helix disappeared from the gulches. The higher peaks, and the 

 largest and most promising canyon, Whitewater, were left un- 

 explored. The wagon needed a broken road, and as the track 

 down the San Francisco had been destroyed by floods we kept 

 the Silver City road for about thirty miles, then turned south- 

 west at Cactus Flats, driving through a beautiful pasture coun- 

 try for about forty miles. It was so beautiful that we went in- 

 to camp and cleaned shells for a couple of days on the bank of 

 a shaded stream. 



Leaving this pasture country, where we trotted the horses the 

 only time on the trip, the party returned easterly again, and 

 over a rough hilly country of Juniper and rattle-snakes, drove 

 for two and one-half days, to Steeple Rock, a mining town in 

 its resting period. South again fourteen miles to Duncan on 

 the Gila, then thirty-two miles down the river, northwestward, 

 to Clifton. The cowboys cross from Mogollon to Clifton in one 

 day, but it took seven days of travel with a farm wagon. Al- 

 together in three months we made a journey of 335 miles. 



Apparently the same snails inhabit this land here, in a direct 

 and pure line of ancestry from those living upon the land before 

 the mountains were uplifted. The conditions after the uplift 

 upon the White and Blue Mountains of Arizona and the north- 

 ern slope of the Mogollons in New Mexico remain about the 

 same, and with the isolation and the 100 miles of deserts, rivers 

 and mountains between, the Ashmunellas and the Oreohelix 

 are the same. This also remains true of the shells in the 

 Kaibab plateau, northern Arizona. 



On both the northern and southwestern slopes of the Mogol- 

 lons are found all the forms, colors and sizes of 0. barbata, that 

 the Chiricahua mountains, 125 miles south, have given. This 

 is the only member of the southern mountain groups that has 

 traveled, outside of the small forms, such as Pupas, Thysanophora 

 and Vallonias. Where the peaks are sharper, divided by dry 

 gulches, the snails divide into species, varieties and groups. 

 In one limestone slope of the Dragoon mountains a dike of 

 granite 50 feet in thickness divides the Holospiras into two dis- 

 tinct species. 



