March, 1904. Mammals of Southern California — Elliot. 277 



8,000 feet so small that its limited fauna and flora do not show the 

 characteristic forms belonging to such altitudes. The higher parts 

 of the Range, in contrast to the usual eruptive formation of the 

 desert ranges, is made up almost wholly of sedimentary rocks. The 

 ridge and sides of Telescope Peak are composed of slate, which 

 formation evidently accounts for much of its steepness. Lower 

 down, the Range is made up largely of a hardened, metamorphosed 

 sandstone of various colors, with its strata much contorted and 

 folded. Various kinds of schists form a large part of the rock forma- 

 tion also. Lower down, some granite and much porphyry and 

 basaltic lava form the slopes of the Range. The Panamints are 

 evidently much younger than other desert ranges and have not been 

 subject to erosion long enough to wear away the sedimentary rocks 

 which overlie the igneous or eruptive series, except near their base. 



The Panamint Range is flanked by the lowest and hottest deserts 

 in America and is everywhere subject to extreme dryness. On 

 account of these conditions the Lower Sonoran Zone extends far up 

 the mountains, the creosote bush, its characteristic floral species, 

 reaching an altitude of 5,000 feet. The lower edge of the Upper 

 Sonoran Zone, which is marked by the Juniper Belt, extends down 

 to 6,000 feet. Between these two belts a small shrub, Coleogyne, 

 forms a nearly pure growth and covers large tracts at the north end 

 of the Range between these altitudes. The pinon, Pi 11 its mono- 

 phylla, forms an extensive forest between the altitudes of 7,000 and 

 9,500 feet. Above the area of the pinon the white-barked pine, 

 Piu us flcxilis, predominates for a short distance and extends to the 

 summit of Telescope Peak, where it becomes a prostrate shrub. 

 From 9,000 feet to the summit of the highest peaks the bristle-cone 

 pine, Piuits aristata, forms a heavy forest of tall columnar trees, in 

 which P. flcxilis is seldom seen. The last two species, in the absence 

 of the yellow pine, evidently mark the Transition Zone, although 

 the latter is closely related to the Boreal-timber-line tree of the 

 Sierras. Piuits flcxilis, however, is found commonlv in the Yellow 

 or Black Pine Belt of the Sierras, beyond which belt it does not extend 

 far. Besides the pines and junipers, the following species were found 

 in the Upper Sonoran and Transition Zones: 



Populits tricocarpa. — Balsam cottonwood; a few seen in Han- 

 nopee Canon, at 8,500 feet. 



Salix. — Various species of willows occurred in the canons to an 

 altitude of 9,000 feet. 



Cercocarpus. — Mountain mahoganv was abundant about the Coal 

 Kilns and ranged from 7,000 to 9,000 feet. 



