



1916] Kellogg: Mammals and Birds of Northern California 367 



orange buff on the sides, and somewhat lighter between eyes; thigh 

 patches small, same color as back, darkening towards ankle; supra- 

 orbital white spot distinct; black ring around eye; white spot on 

 upper edge of ear; line over nose and at base of whiskers black; 

 upper portion of feet white, beneath seal brown; upper and lower 

 tail stripes seal brown, the upper merging into black some distance 

 in front of the white pencil. Underparts pure white. 



Measurements. — Of type, total length, 310 millimeters; tail 

 vertebrae, 194 ; hind foot, 46 ; height of ear, 14. Length of nasals, 

 measured along median line, average of 12 adult males, 14.7 milli- 

 meters, average of 3 adult males of D. californicus, 13.5 ; average 

 of 10 adult females of D. c. trinitatis, 14.3 ; average of 5 adult females 

 of D. californicus, 13.5. Greatest anterior breadth of nasals, average 

 of 12 adult males of D. c. trinitatis, 4.3; average of 3 adult males of 

 D. californicus, 3.6 ; average of 10 adult females of D. c. trinitatis, 4.3 ; 

 average of 5 adult females of D. californicus, 3.8. 



Discussion. — This new subspecies is based chiefly on the series of 

 fifteen skins (nos. 12854-12868) obtained at Helena. These are 

 in winter pelage, while the 28 specimens (nos. 13665-13692) from 

 Scott River, Siskiyou County, are on account of the difference in 

 season slightly lighter in average coloration. In these the orange 

 buff of the sides is more pronounced, but the skull characters are 

 similar. The series from Helena, compared with topotypes of 

 californicus, from Ukiah, Mendocino County, is distinctly darker 

 both in the general color and, more markedly still, in the color of 

 the dark stripes on the tail. The white of the thighs appears 

 restricted and in the dry skins is almost concealed. Such exterior 

 differences, however, are not so convincing as points of difference 

 that can be readily distinguished in the skull, and in the case of 

 this subspecies the length of the nasals and their width anteriorly 

 are well-marked characters. 



Another subspecies, Dipodomys californicus pallidulus (Bangs, 

 1899, pp. 65-66), has been described, from Sites, Colusa County; 

 but a study of a series of topotypes of this form in the collection 

 of the Museum of Vertebrate Zoology does not substantiate the 

 subspecies. The characters given for 'pallidulus as compared with 

 californicus are: "Color very much paler; thigh patches not dusky; 

 . . . the black markings at base of whiskers and over nose . . . 

 nearly wanting . . . ." A further statement (Elliot, 1901, p. 



