220 Unii'crsitjj of California P)(hJications i)) ZooJofjij. IVol. 7 



thence northeast along the Colorado River passing into the sub- 

 species cinnamomeus in the Painted Desert of northeastern 

 Arizona, and interpres in New Mexico and Texas. Nevada is 

 not mentioned as part of its habitat. Bailey (1908, p. 8) in- 

 cludes the antelope squirrel among the mammals inhabiting the 

 "arid interior," particularly the Humboldt and Carson valleys, 

 Nevada. Records from northern Humboldt County thus defi- 

 nitely extend the known range of the species. 



Habits. — An observer in the tield is immediately impressed 

 with the general similarity in habits of Ammospcnnophilus 

 leucurus and Citellus mollis. The larger more strikingly colored 

 tails of the former afford the best means of identification. (For 

 remarks on coloration of the antelope squirrel see C. H. "Sler- 

 riam, 1890b, p. 52.) They were shy, and after seeing the col- 

 lector were soon out of sight. JNlost of those noted were juvenals. 

 The first young one was secured June 20 at Big Creek Ranch, 

 and an older immature June 17 at the mouth of Alder Creek. 



The species is typically one of the sagebrush flat, but ranges 

 a few hundred feet higher up onto the barren foothill ridges. 

 Apparently the squirrels do not venture very far from their 

 burrows, which are very often among rocks. Seated on its 

 haunches on a roclv, one was heard to utter a chuckling note. 



Callospermophilus trepidus Taylor. 

 Nevada Golden-mantled Ground Squirrel. 



Habits. — The experience of our party in capturing this 

 animal was very similar to that recorded by Alien (1895c, p. 

 :VM)) and Grinnell (1908, p. 142) for other species of the genus, 

 in that a large proportion of those secured were juvenals. Out 

 of thirty-eight specimens taken by us only ten were fully adult. 

 This shows that the young are born rather early in the summer. 

 A number of females showed signs of having suckled young. l)ut 

 none contained embryos. 



As already recorded (Taylor, 1910, p. 28()), two of the adults 

 and many of the juvenals were undergoing a molt into the 

 brighter pelage. The other adults and juvenals had already 

 assumed the post-breeding, or first winter pelage, respectively. 



The first evidence of the presence of these squirrels was the 



