2(12 University of California Publications in Zoology [Vol. 10 



thickets are more numerous and cover larger areas, in many 

 places extending out upon the floor of the valley. At Vandeven- 

 ter Flat there are many large-sized live oaks. The scaly-barked, 

 reddish-colored Adenostoma sparsifolium is about the most con- 

 spicuous feature of the chaparral of this region, while the fact 

 that it was always found in association with the gray vireo 

 ( Vireo vicinior) brought it forcibly to our notice. The ranges 

 of the two in the San Jacinto Mountains were found to be abso- 

 lutely the same (see p. 291). 



There are settlements in Hemet Valley : at the Thomas Ranch, 

 a large and prosperous ranch just above Hemet Lake; at Ken- 

 worthy, where there are several small ranches and the mines 

 above mentioned, the latter abandoned, but mills and other build- 

 ings still standing; and at Vandeventer Flat, a single ranch. 



We established a base camp at Kenworthy on May 19. making 

 it our headquarters until July 5. Collecting was prosecuted in 

 the vicinity from May 19 to 25 and from June 2 to 11. 



Dos Palmos Spring 



On the desert slope of the Santa Rosa Mountains, at 3500 

 i'eet altitude. Two palm trees in a narrow, rocky gulch mark 

 the source of a trickle of water which flows over the rocks for 

 a few hundred yards and sinks in the sand where the canon opens 

 out upon the more level mesa. This station, below the belt of 

 pinon and sage, is about on the upper margin of the Lower 

 Sonoran zone, with an abundance of typical desert plants and 

 animals. The rolling mesa of hard gravel or sand, with occa- 

 sional rocky outcroppings, traversed by many sandy washes and 

 gulches, supports a fairly dense growth of brush, creasote, several 

 species of cactus, pluchea, yucca, and other plants of low zone 

 (see pi. 10, fig. 1). Along the water courses are dense thickets of 

 desert willow (Chilopsis) , mesquite and catclaw; in several rocky 

 gulches, clumps of two or three palms ; and on the stony hills 

 some two miles below the spring the uppermost limit of the 

 ocotilla is reached. 



Two miles to the northward Black Hill, a conspicuous land- 

 mark, rises abruptly from the mesa, a jumbled pile of loose, black 

 rocks, almost destitute of vegetation. The stream flowing from 



