1913] Grinnell-Swarth: Birds and Mammals of San Jacinto 335 



Peromyscus eremicus eremicus (Baird) 

 Desert White-footed Mouse 



The seventy-five specimens collected represent localities as 

 follows: Banning, 2300 feet, eight (nos. 1449-1456); Cabezon, 

 twenty (nos. 1284-1300, 9339-9341) ; Snow Creek at 1500 feet, 

 eight (nos. 1563-1567, 1578-1580) ; Palm Springs, 450 feet, three 

 (nos. 5983, 5984, 6803) ; Palm Canon, at various altitudes, ten 

 (nos. 2068-2074, 9342-9344) ; vicinity of Dos Palmos Spring, 

 3000-3500 feet, twenty-six (nos. 1940-1947. 1958-1967, 1998- 

 2005). 



It is observable that all of these localities are on the desert 

 side of the mountains, and all are either well within the Lower 

 Sonoran zone, or at highest (Banning) in the belt of blending 

 of that zone with the next higher. Thus, within the same genus, 

 we find a species (sonoriensis) apparently oblivious of tempera- 

 ture range, while the present, eremicus, is closely limited to the 

 climatic conditions obtaining in one division of one zone. 



The desert white-footed mouse appears to affect by preference 

 sandy ground rather sparsely provided with clumpy xerophytic 

 shrubs. 



Our series of specimens is very uniform in the main observ- 

 able characters, save as obviously due to age. The specimens 

 from Banning are a trine the darkest, a possible tendency 

 towards P. e. fraterculus, the Pacific Coast race of the species. 

 The latter, however, we failed to find in San Jacinto Valley, 

 though we had anticipated its occurrence there. The series 

 as a whole closely resembles material from the lower Colorado 

 Valley. In mass effect the latter are faintly paler-colored. 



Reithrodontomys megalotis longicauda (Baird) 

 Long-tailed Harvest Mouse 

 Localities of capture were : Banning. 2200 feet, five (nos, 

 1457-1461) ; Cabezon, 1700 feet, five (nos. 1301-1305) ; Snow 

 Creek, 1500 feet, one (no. 1569) ; Schain's Ranch, 4900 feet, three 

 (nos. 1632-1634) ; Strawberry Valley. 6000 feet, one (no. 2097) ; 

 Hemet Lake, 4400 feet, three (nos. 2244, 2245, 9345). The last 



