110 THE NAUTILUS. 



There must be a difference in the anatomy of different lots of Sue- 

 cinea avara sent in. We found it plentiful on the ant hills in the 

 Antelope valley, a desert as dry as the St. Simon valley. Again 

 on the hottest and dryest of mountain rock at the Hurricane Fault. 

 Still again we found it v/ith Oreohelix at the Big Springs in the 

 Kaibab Mountains living in as moist a situation as we find Polygyra 

 multilineata. These were of a different color, larger and more cor- 

 pulent. 



After this I hope to go into strange countries with U. S. Geologi- 

 cal folios in addition to the contour maps, for the whole Mt. Trum- 

 bull country was of lava formation, barren of shells except the small 

 truck. We need limestone and shelter in our business. The Hurri- 

 cane Fault had lime but no shelter and was equally as barren. This 

 Trumbull side-trip took half of our time and cost a lot of money, but 

 we enjoyed it. We love the Mormons, at least their cooking, and I 

 am now physically perfect until next August. 



I will send you a map marking our collecting stations. There 

 were 113 of these. Oreohelix was found at perhaps 100 stations and 

 80 of these are unlike any other colony in color, size or architecture, 

 while each colony is reasonably uniform individually. We had a 

 theory when we left the Two Springs canyon that the shells were 

 small and dark in the higher altitudes and that they grew larger in 

 a regular ratio as we pasf-ed to the lower levels, but in the Warm 

 Springs Canyon the shells were largest at the upper stations and 

 smaller at the lower. In the Snake Gulch they were smallest at the 

 midway stations, and in Quaking Asp canyon it was a skip about 

 between large and small. At Castle Springs, heavily shaded and in 

 elderberry bushes, we found the largest. At Big Springs, facing 

 the sun, moisture abundant, they were small with many albinos. 

 Thus as to elevation, shade, moisture, soil or food we have no theory 

 except like old time chickens they may just happen to be large, 

 small and. middling, ring-banded, streaked or speckled. Our largest 

 measured 30 mm. diam. and our smallest 8 mm. In the Huachucas 

 the colonies of Oreohelix are of mixed forms, but the Kaibab shells 

 are of one kind in each colony, with occasional albinos. Some of 

 the colonies apparently divided their rock slide territory into families, 

 designated by size or color. In one instance passing around the 

 point of a rock, less than one hundred feet, and good traveling for 

 snails, the colony on one side was as large again in size as those upon 



