MAMMALS OV THK MKXTOAN BOUNDARY. 



347 



place late in June, the young were frolicking abroad in numerous 

 families in utter disregard of our presence. Near Chavez Pass enor- 

 mous areas were covered by their colonies. 



In Aravaipa Canyon, in southern Arizona, the Arizona prairie-dogs 

 {Cynomys liodovicianus arizonensis) were active during the coldest 

 weather; but the short-tailed prairie-dogs living in the Agua Fria Val- 

 ley between Forts Verde and Whipple do not appear during the cold- 

 est periods, but venture ' forth as soon as the weather moderates. 

 Probably those residing on the San Francisco Mountains, where the 

 winter is long and cold and the ground deeply covered with snow, 

 regularly hibernate, as the large ground-squirrel {Otospermophilus 

 grammurus) is known to do; but early in April, 1886, we found them 

 out of their burrows, close to the snow which still covered the divide 

 of the MogoUon Mountains. 



This barking-squirrel is gi-aminivorous, devouring nearly every 

 green thing within its settlements, which in consequence become 

 barren and forbidding in appearance. Lack of food or sudden inunda- 

 tions are the ordinary causes leading to a change of location, which is 

 usually accomplished b3' a gradual invasion of contiguous territory'. 



An interesting chapter might be written under the caption of "The 

 prairie-dog as a pet," to which every army youngster could contribute 

 something of interest from personal experience. In captivity it is 

 playful, and makes an extraordinarily bright and agreeable pet. It 

 is fond of raw meat, and drinks water freely. Its propensity for 

 undermining the walls of the buildings and digging up the yards is 

 regarded as reprehensible by some; but, to juvenile minds, such 

 trifling peccadillos are more than compensated for by its clever tricks 

 and its attachment for its master, at whose clothing it will tug when 

 ready for a f I'olic or desirous of being fed. 



MeajturemenU of 77 spi'cimen.i of tlie genus Cynomyn. 



Locality. 



C^/nomys gunniaoni. 



Agua Fria post-office, central 

 Arizona. 



-do. 

 .do. 

 .do. 

 .do . 



Mormon Lalce, Mogolion 

 Mountains, Arizona. 



....do 



1884. 

 Apr 25 



1887, 

 Nov 6 



....do... 



....do... 

 ...do... 

 May 30 



May 31 



Sex and 

 age. 



9 ad. 



<f ad. 

 tfad 

 cf ad. 

 cf ad. 

 rfad. 



?ad. 



mm. 

 333 



367 

 351 





mm. 

 65 



60 

 62 

 61 

 61 

 62 



mm. 

 5.0 



6.0 

 6.0 

 7.0 

 6.0 



7.5 



oAtaerican Mnseum of Natural History. 



