SCIURIDHZ—TAMIAS ASIATICUS AND VARIETIES. 795 
America southward nearly to the United States, decreasing in size and 
becoming brighter in color southward, in the interior, and thus passing grad- 
ually into var. guadrivittatus. 
Var. QUADRIVITTATUS. 
Rocky Mountain Chipmunk. 
VaRIETAL CHARS.—Length of head ard body 4.50 to 5.00; of tail to end 
of vertebrae about 3.50; to end of hairs about 4.50. Pattern of coloration 
strictly the same as in var. borealis, but the colors brighter, with much more 
rufous, and the size smaller. Under parts sometimes faintly tinged with fulvous. 
The black dorsal stripes are edged and more or less mixed with rufous; the 
light stripes, particularly the outer, are whiter, varying from grayish-white to 
pure white; the sides of the body, especially anteriorly, are bright reddish- 
ferrugineous; the tail yellowish-rusty, with a subterminal border of black 
edged with yellowish. 
Hasirat.—Middle and southern portions of the Rocky Mountains, from 
near the northern boundary of the United States to New Mexico. Also in 
the mountain-ranges, thence westward to the Pacific coast, and in the Black 
Hills. Most specialized in the mountains of Colorado. Passes insensibly, at 
the northward, into var. borealis; at the eastward and in the Great Basin, 
into var. pallidus; in Northern California and Oregon and in the Bitter Root 
and Cascade Ranges, into var. townsendi. 
Var. PALLIDUS. 
Pale Chipmunk. 
VARIETAL CHARS.—Smaller and paler than var. quadrivittatus. Length 
of head and body 4.25; of tail to end of vertebrae 3.25; to end of hairs 4.00 
to 4.25. General color above pale whitish-gray, the sides slightly washed 
with pale fulvous. The dark dorsal stripes are dusky, faded reddish-brown ; 
outer pair of light stripes nearly white, inner grayish-white; generally only 
the middle dark stripe decidedly blackish. Yellow of the tail very pale 
clay-color. 
Hasirat.—The dry plains of the Upper Missouri and Yellowstone and 
the desert plains of the Great Basin. Everywhere passing into var. guadri- 
vittatus at the edges of the wooded mountain-ranges, of which it is merely a 
depauperate pallid form. The prevalent form over the plains of the Yellow- 
