1913] Grinnell-Swarth : Birds and Mammals of San Jacinto 331 



skins might upon their separate merits be referred to gambeli, 

 and it is patent that the mean of the whole aggregate might 

 fall between typical sonoriensis and typical gambeli; but we feel 

 that the leaning of the mode is most strongly toward the former. 

 The San Jacinto region is again shown to lie on the borderland 

 between two faunal areas, their distinctive forms here blending 

 or hybridizing, which, is not easy to say. Osgood (1909, pp. 

 68—70, 91 I lias admirably treated of the problem in similar 

 situations in his revision of the genus Peromyscus. 



Peromyscus boylei rowleyi Alien 

 Rowley White-footed Mouse 



Our collection contains 131 specimens apportioned by locali- 

 ties as follows: (iarnet Queen Mine. 6000 feet, twenty-three 

 (2008-2028, 9334, 9335) ; Kenworthy, 4500 feet, five (nos. 1790 

 1704); Thomas Mountain. 6800 feet, twelve (nos. 2218-2228, 

 9337); Hemet Lake. 4300 feet, two (nos. 2242. 2243); Straw- 

 berry Valley, 6000 feet, twenty-one (nos. 2098 2117. 2128) ; Tah- 

 quitz Valley. SIMM) feet, fourteen (nos. 2203-2215, 9336) ; Round 

 Valley. 9000 feet, thirteen i nos. 1767. 1778-1789); Puller's 

 Mill, 5900 feet, eighteen (nos. 1717. 1728-1744) ; Schain's Ranch. 

 4900 feet, twelve (nos. 1678-1689); Cabezon, 17DO feet, four 

 (nos. 126S. 1200. 1585, 9338) ; Snow Creek. 1500 feet, four (nos. 

 1584, 1586-1588); Dos Palmos Spring. :;:><><} feet, three (nos. 

 1910-1912). 



This species would appear to lie about as widely distributed 

 through this region as Peromyscus m. sonoriensis; for it is 

 recorded from fully as many stations. Bu1 /'. h. rowleyi has 

 much more marked assoeiational restrictions, being very closely 

 confined to the vicinity of water courses. Although ranging from 

 Rower Sonoran. as at Cabezon, to the highest station in Boreal 

 when 1 any trapping was carried on. the low /one captures were 

 made along streams where the contention might well be made 

 that at least one zone higher was the one really present, although 

 closely hemmed in on either side by the lower zone. The metrop- 

 olis of rowleyi, judging from its distribution elsewhere in south- 

 ern California as well as in the area under consideration, is 



