MAMMALS OF THE MEXICAN BOUNDARY. 289 



Type-locality — Fort Webster, Copper Mines of the Mimbres, Granl 

 County, New .Mexico. Int. 32° 47', long. 108° 4'. (Type, skin with 

 fragment of skull. No. 3151, l'. S. National Museum.) 



Geographical range. — Upper Sonoran to lower edge of Transition 

 Zone of the Elevated Tract. 



Description. — Size medium; ears high and pointed: tail long, and 

 rather bushy: pelage short, hut silky and dense. Coloration pallid, 

 all hut the median dorsal stripe being obsolete. In post-breeding 

 pelage the color above is whitish gray, finely mixed with blackish 

 and vinaceous; dorsal stripes faintly outlined: sides, and anterior 

 portion of limbs, yellowish brown; ventral surface soiled white. 

 the fur plumbeous at base. Side of head, with three dark and two 

 white longitudinal stripes, the middle dark one involving the eye. 

 Post-auricular patch large and white. Ear whitish, with anterior 

 border rusty brownish, this pattern being reversed on its inner sur- 

 face. Tail broad and bushy, iron-gray above, and longitudinally 

 striped below, where the central area is orange-rufous, bordered on 

 each side, successively, with hurt', black, and gray, giving a 7-striped 

 pattern. Hands soiled white; feet buff. Mammae, 4 pairs. 



The winter pelage is. of course, grayer, the upper surface lacking 

 the vinaceous tint, the subterminal zone of the underfur being nar- 

 rower, paler, and more yellowish. 



Measurements. — Average of ten adult males: Length, 231 mm.: tail 

 to end of vertebra?, 103 ; tail to end of hairs, 131 ; hind foot, 34.8 ; ear 

 from crown. 15.9; ear from notch, 21.6; head, 40.3: distance from 

 nose to eye, 16; nose to ear. 32. Average of fifteen adult females: 

 Length, 238 mm.: tail to end of vertebra'. 104: tail to end of hairs. 

 134; hind foot, 34.<> : ear from crown, 16.2; ear from notch. 21.2; 

 head. 40.0; distance from nose to eye, 16.2 ; nose to ear, 32.3. Skull, 

 39 by 21. 



Skull and teeth. — Skull (fig. 47) similar to that of Eutamias cin- 

 , /■( icollis, but with braincase longer and lower, and the skull narrower 

 anteriorly: incisors broader. 



Life history. — The Gila chipmunk, as its name implies, is an in- 

 habitant of the Gila Basin; but its range is not restricted thereto, 

 and may also be found to cover a considerable portion of the Colorado 

 and Yaqui River basins. Its preference seems to be for broken. 

 rocky country, where there is timber: yet it inhabits long reaches of 

 barren canyons, entirely destitute of trees. It must, necessarily, be 

 able to subsist on a great variety of food, else it could not exist under 

 such diverse conditions. Although quite abundant, in suitable locali- 

 ties, in the pine zone, it is more characteristic of the jagged canyon-, 

 rocky basins, and precipitous slopes bordering the mesas, which con- 

 stitute such marked topographical feature- of this region, and which 

 30639— No. .">c— 07 m 19 



