MAMMALS OF THK MEXICAN BOUNDARY. 319 



instant disappearance under the buildings. A large pile of shingles, 

 lett over from reroofing the hospital, and long a bone of contention in 

 the garrison, was neatly piled up in a corner of the hospital yard. 

 This was the favorite rostrum of the ground-squirrels, who sat up erect, 

 with their forepaws hanging down, and chirped a welcome to me as I 

 passed into the hospital at the sounding of surgeon's call in the morn- 

 ing. Their ordinary note is a loud, hollow whistle, which reminds one 

 of the call of the black-headed grosbeak {Bahiamelanooephala), though 

 louder and more penetrating in character; following it, when one is 

 close by, a chipmunk-like chippering is heard, so low as to be inau- 

 dible at a short distance. 



As one rides among the rocky foothills, this squirrel is frequently 

 seen curled up in the top of a scrub-oak bush, eating acorns or sun- 

 ning itself and uttering its characteristic note. It loves the sunshine 

 and delights to absorb the warmth and enjoy the scenery from the 

 highest point of some rock pinnacle. The ancient cliff dwellings and 

 ledges in the rocky canyons are its favorite abode. Many of its bones 

 were exhumed from the buildings of the cliff dwellers in the vicinity 

 of Fort Verde. 



The "Point of Rocks," near Whipple Barracks, Arizona, is a huge 

 pile of granite rock, of ver)^ coarse structure, several miles in extent. 

 It is divided by the canyon of Granite Creek, and furrowed by numer- 

 ous side canyons and crevices. It contains a number of basins and 

 deep indentures, with many towering points often capped by enor- 

 mous rounded bowlders, balanced as if in imminent danger of falling. 

 There are a few pines and pifions, some scrub and tall evergreen oaks, 

 together with hackberries and cedars in the ravines, and willows along 

 the stream. These large ground-squirrels were very numerous upon 

 the piles of rounded granite rocks. Those shot there in November were 

 coated with fat, as is the rule at this season. They were swift and 

 graceful climbers, though by no means comparing in this respect with 

 the still more abundant Gila chipmunk {Eutaviias dorsalis), whose 

 agility and celerity of movement, displayed in running over the rug- 

 ged rocks, were positively amazing. 



Though swift and sure-footed in rocky places, this species immedi- 

 ately loses confidence and seems to become paralyzed by fear when 

 surprised in trees, which, however, it climbs regularly to obtain food. 



The season of reproduction, as might be surmised, from the varying 

 conditions of altitude, climate, etc., to which- the species is subjected, 

 varies greatly with locality. In the low regions it probably rears 

 more than one litter of young annually. On June 20, 1886, I shot a 

 female at Flagstaff, Arizona (altitude 6,886 feet) that was suckling 

 young. At Fort Verde on March 30, 1 887, a rutting male was shot, 

 sporting with a female.. On May 6, following, young more than 

 ]ialf grown were shot on the summit of Squaw Peak, the highest point 



