324 University of California Publications in Zoology. [Vol. 7 



at Quinn River Crossing are typically Sonoran in distribution, 

 many of them being found elsewhere not lower than Upper 

 Sonoran. On the other hand, while a number of the animal 

 species abundant at this locality (e.g., Oreoscoptes montanus, 

 Dendroica aestiva hrewsteri, Eutamias pictus, Perognathus par- 

 vus olivaceus, TJCamnophis vagrans) occur also in Transition, no 

 species in other localities characteristic of, or limited to, that 

 zone, with the possible exception of Otocoris alpestris merrilli 

 and Sceloporus graciosus, were found at Quinn River Crossing. 

 The conclusion seems justified, therefore, that the Quinn River 

 Valley in this vicinity is Upper Sonoran. 



Pine Forest Mountains (4350-9400 feet; Biological. Cross- 

 section Camps nos. 1 to 8). — If one stands upon a high point 

 and looks out over the lower slopes of the range he is impressed 

 immediately with the excessively arid appearance of the moun- 

 tains as a whole (see pi. 8, figs. 1 and 2). No trees are to be 

 seen anywhere at the lower altitudes, except for the very narrow 

 and often broken lines along streams. The lower ridges, lying 

 baked and bare, are observed to be unprotected except by a very 

 meager growth of sagebrush or associated xerophytes. In the 

 higher parts of the mountains, the scene is somewhat more varied 

 (see pi. 10, fig. 1). A few quaking-aspen groves are noted on 

 the more humid of the meadows, and brush-like patches of the 

 same species of tree are apparent on certain favorable steep 

 slopes. Furthermore, a tract of limited proportions, confined 

 almost entirely to the western slope of the mountains, is seen to 

 be occupied by small limber pines, Pinus flexilis (?) (see pi. 11, 

 fig. 1). It is unfortunate that the identification of the pine is 

 based on foliage only, no cones being at hand. Geographic and 

 zonal considerations indicate that it is Pinus flexilis, although 

 its identity can not be considered to be certainly established. 

 Scattering groups of mountain mahogany are observed on certain 

 of the western ridges (see pi. 10, fig. 2). 



The topography of the higher parts of the mountains seems 

 to indicate the former presence of glaciers. Several hanging 

 valleys were observed, and in three localities, namely at the head 

 of Leonard Creek, in the vicinity of Alder Creek Lake, and at the 

 head of Big Creek, there are land forms resembling cirques. 



