CATALOGUE OF MAMMALS COLLECTED BY E. HELLER 

 IN SOUTHERN CALIFORNIA. 



BY I). G. ELLIOT, F. R. S. E., ETC. 



On his return from the expedition into the San Pedro Martir 

 Mountains in Lower California, Mr. Heller was instructed to continue 

 collecting in the Colorado and Mohave Deserts, Death Valley, 

 and the various mountain ranges in the vicinity of these, visiting as 

 many as possible of the type localities accessible on his proposed 

 route. In pursuance of the course indicated for him to follow, he 

 commenced his labors in February, 1902, at Whitewater, where 

 four days were passed. This place is fifteen miles from Palm Springs 

 and at the eastern terminus of San Gorgonio Pass and the extreme 

 western end of the Colorado Desert at an elevation of 12,000 feet, 

 and here topotypes of Dipodomys m. similis = D. m. simiolus, were 

 procured. "The vegetation about Whitewater is almost wholly that 

 of the Lower Sonoran of the desert. The creosote bush, the char- 

 acteristic species, is abundant about the ranch and to the west as 

 far as Cabezon, ten miles from the mouth of the Pass. The mesquite, 

 Prosopsis julifera, extends westward to the same limits as the creosote. 

 A small tree yucca, Y. mohavensis, is abundant, and forms a con- 

 spicuous part of the vegetation." 



From Whitewater Mr. Heller went to Palm Sprixgs, a village on 

 the Colorado Desert situated in a cave of San Jacinto Mountain and 

 about fifteen miles east of Whitewater. "The desert at this place," 

 writes Mr. Heller, "is a level plain of white sand, recently a bed of 

 the arm of the Gulf of California, but now 4,000 feet above sea level, 

 from which the mountains rise abruptly in some places, forming 

 cliffs, and the mouths of the canons are marked by great alluvial 

 fans which rise a considerable height above the plain. Although so 

 close to Whitewater, the conditions are much more those of the 

 desert, and the heat in summer is extreme. The Lower Sonoran Zone 

 spreads out over the entire desert and reaches into all the canons, 

 and ascends the sides of the hills as high as 3,000 feet. The creosote 

 bush grows here to large proportions and forms a continuous belt 

 from the lower hills well out into the desert. The mesquite, Prosopis 

 julijlora, and the desert willow, Cliilopsis linearis, are generally dis- 



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