University of Michigaii 



PLATE I. 



Figure I. The valley of the Humboldt River in Maggie Basin. On 

 the right the valley rises to the foothills of the Pinyon Range, on the 

 left to a dry flat covered with fine soil. The lowest part of the valley has 

 a vegetation of grasses, with small trees and shrubs along the streams, 

 ponds and ditches, which is replaced near the sides by a zone of 

 Chysothamnus pinifoUus, and the reptile-amphibian fauna -comprises 

 the following forms : Thamnophis ordinoides elegans, Rana pretiosa 

 luteiventris, Rana pipiens, Bufo boreas, Pituophis catenifer dcscrticola, 

 Bascanion constrictor z'etitstum and Bascanion tacniatum. 



'Figure 2. The flat on the north side of the Humboldt Valley. The 

 basin ridges of waste limit this flat on the north (background). The flat 

 has a fine soil and numerous alkali spots, and supports an open growth 

 of sagebrush. The reptiles found here were Cnemidophorus tigris, 

 Phyrnosoma hernandesi, Sceloporus graciosus, Crotaphytus wislisenii, 

 Pituophis catenifer deserticola, Bascanion constrictor vetustuni, Bas- 

 canioti tacniatum. No amiphi'bians were found on the flat. 



