330 Univi rsity of California Publications in Zoology [Vol. 10 



of the above specimens is a half-grown Juvenal. All were caught 

 on the gravelly floor of the valley among scattered brush, the 

 station being within the Lower Sonoran zone. 



Peromyscus maniculatus sonoriensis (LeConte) 



Sonora White-footed Mouse 



A series of ninety-six specimens was preserved as follows: 

 Round Valley. 9000 feet, three (nos. 1763 1765); Tahquitz Val- 

 ley, soon feet, twenty-two (nos. 2168 2187, 9332, 9333); Straw- 

 berry Valley. 6000 feet, three i nos. 2075 2077 I ; Santa Rosa Peak, 

 at 7500 feet, three inos. 2038 2040); Kenworthy, 1500 feet, 

 thirty-one (nos. 1811 1817, 1828 1847, 1858, 9329 9331); Valle- 

 vista. 1800 feet, four nos. 2255-2257, 9384 I ; Fuller's Mill, 6000 



feet, two (nos. 1649 1650 ; Schain's Ranch, 1900 leet, eighl s. 



1648, 1671-1677); Banning, 2300 feet, two (nos. Mill. 1464); 

 Cabezon, 1700 feet, fifteen nos. 1265, 1270 1283); Snow Creek 



at 1500 feet, one (no. 1598); Whitewater. 1130 feet, two nos. 



l.~>77. 1599). 



The species was thus captured at almost every collecting sta- 

 tion, from the highest point at which traps were set (Round 

 Valley. 9000 feet) to both the Pacific ami desert bases of the 

 mountains. As is notoriously the case elsewhere, this mouse 

 ignores zone limits in its dissemination, occurring in the San 

 Jacinto region from Lower Sonoran to Canadian, inclusive of 

 both zones. Furthermore, it ranges indiscriminately through 

 differenl associations, being caught among cactus and creasote 

 brush on the dryest desert floor, on sage flats, in chaparral, ami 

 in veratrum patches on wet Boreal meadows. 



Our large series of specimens shows such a range of appar- 

 ently individual variation, both as to color and size, as to baffle 

 oui- attempts at segregation on geographical grounds. A paling 

 desertwards, as with so many of the mammals of the region, 

 might well lie expected; and there may he such, if our senses or 

 methods were refined enough to take proper ; ounl of the varia- 

 tion from other than geographical causes. 



Taking the whole series in mass effect, we feel justified in 

 employing for it the one name sonoriensis, thus following Osgood 

 (1909. p. 93) in the disposition of his material. Many individual 



