296 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



the young depends on the season of birth, those horn early having the 



winter and those horn late the summer pelage; the color and quality 

 of the coat vary accordingly; in sonic the ventral surface is washed 

 with fulvous. 



A specimen (No. 61132, U.S.N.M.) taken on the hot east slope of 

 the Coast Range Mountains, near Mountain Spring, was in complete 

 post-breeding or summer pelage May 15, at which season those on 

 the peaks and west slope of these mountains were still in winter 

 pelage. Very few of those taken at Laguna, in the pine zone. June 

 ( .» to 21, were out of the winter pelage; those in summer pelage were 

 immature, probably horn the preceding year. The Mountain Spring 

 specimen differs from all the rest in being paler and browner, with 

 no black in the dark dorsal stripes, except in the middle of the 

 median one. the two outer pairs being reddish brown, the outermost 

 blending with the cinnamon of (he sides. 



Measurements. — Average of five adult males: Length, - 247 mm.; 

 tail to end of vertebrae, 115; tail to end of hairs. 144; hind foot. 36; 

 ear from crown, 13. Average of fifteen adult females: Length, 2,54 

 mm; tail to end of vertebras, 121; tail to end of hairs, 151; hind 

 foot, 36.4; ear from crown, 15.1. Skull, -V.) by 20.5. Mammae, four 

 pairs. 



Sir nil. — Compared with Enfant his cinereicollis and /:". dorsalis, the 

 skull is slightly larger, relatively narrower and higher, with the 

 rostral portion less depresed and more elongate, the nasal hones 

 very narrow and suddenly expanded apically, and the interpterygoid 

 fossa longer and narrower. All three species differ from the type 

 of the genus in having the infraorbital foramen reduced to a narrow, 

 slit-like opening instead of a large, open, rounded foramen. 



Habits and local distribution. — We found the Merriam chipmunk 

 ranging from Mountain Spring and the lower slopes of the .Coast 

 Range over the highest peaks, but not extending its range to the 

 Pacific Ocean. The young are probably born in May and June. 

 Fifteen adult females, taken June 7 to*21, 1894, were nursing, none 

 being pregnant. A very young individual was taken at the summit 

 of the Coast Range June 20, 1894. It climbs over rocks, hushes, and 

 trees, feeding upon various seeds, fruits, and berries, but especially on 

 acorns and pine seeds. 



