8 University of Michigan 



entirely dry during the summer months, except during the last 

 half mile of its course, where it is fed by a large spring. In 

 the summer James Creek is discontinuous on the basin floor 

 (PI. II, Fig. 2). 



Near the heads and frequently along the sides of most of 

 the canyons in the Cortez Range which are tributary to the 

 Annie and James, there are small cold springs, some of which 

 flow throughout the summer while others disappear in July 

 and August. From these springs small streams are formed in 

 the summer which usually flow for a short distance and then 

 disappear entirely or reappear farther down the canyon. Fre- 

 quently such streams appear and disappear several times in 

 their course and all of them finally vanish on or before reaching 

 the valley, except that James Creek flows for a short distance 

 on the basin floor. In the spring and during cloudbursts they 

 are probably continuous throughout most of their courses. In 

 the parts of the Seetoya and River Ranges studied, the canyons 

 are without springs and wholly dry in the summer. In the 

 Pinyon Range, Woodruff Creek is undoubtedly spring fed, for 

 in July and August the east branch had a continuous stream 

 of water which only terminated near the mouth of the canyon, 

 while the west branch was dry. There are other springs, both 

 hot and cold, in the region but these are not important factors 

 in the distribution of the vertebrates. They are mostly at the 

 base of the talus slopes when these are near streams. Thus 

 there are several on the bank of the creek in Maggie Canyon, 

 a few along the bank of the Humboldt in Moleen Canyon, and 

 one spring from which a considerable stream of water issues 

 in the summer was found in a small gorge in the southern end 

 of the Cortez Range. 



There are very few permanent ponds or lakes in the region. 

 The few ox-bow ponds in the valley of the Humboldt and in 

 Maggie Canyon have been mentioned. Just south of the junc- 



