430 



BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



usual, the hairs increasing in length from base to tip, those of its 

 under surface being much shorter than above; its color clove-brown 

 above, sometimes white and sometimes dusky below, usually without a 

 line of demarkation between. Body above, brownish gray, coarsely 

 mixed with black, grayish on the head, gradually changing to tawny 

 cinnamon on sides, rump, and outer surface of limbs. As in Perowys- 

 cus merriami, the dark coloring of the outer surface of fore limbs 



Fig. 97.— Pekomyscus . californicus insignis. Skull, a, doksal view; 6, 



C, LATERAL VIEW. 



VENTKAL view; 



extends down to the wrist. The feet are white, except that the dark 

 coloring often extends down on the basal third of the dorsum of pes, 

 as in Neotoma micropus. The under surface is sometimes wholly 

 white, but more often with a pectoral spot of cinnamon or fawn-color 

 on the chest, this, when present, varying from a trace to a large patch. 

 Sometimes there is a colored patch on the 

 throat. The orbital region is dusky. Topo- 

 types (from Dulzura, California) are darker, 

 more mixed with black above in winter than 

 in summer. 



A young specimen, taken at La Jolla, on the 

 edge of the Pacific, February 10, 1892, by Mr. 

 F. Stephens, was one-third grown at the date 

 of capture. This, the youngest specimen in 

 the series of 40 before me, is smoke-gray above, 

 arid has a faint drab staining on the sides, and 

 the barest indication of the pectoral patch; 

 below white, exhibiting much of the gray basal portion of the hair 

 between the narrowly white tips. 



Cranial characters.— There are but two skulls of northern P. cali- 

 fomicus in the U. S. National Museum. One of these (No. ff It) 

 is labeled " Santa Clara," in Professor Baird's handwriting; and the 

 other (No. f ffll) was collected at Baird, in northern California, by 

 Mr. C. H. Townsend. These are rather young, and slightly smaller 

 than specimens of P. c. insignis of the same age. The nasals are a 



Fig. 98.— Pekomyscus cali- 

 fornicus msiGNis. Crown 



OF molar teeth, a, LOWER 



series; 6, UPPER series. 



