312 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



the skull and teeth are unmistakably citelline. In C. lateralis the 

 first upper premolar is smaller than in the remaining species of Cal- 

 lospermopJiUus, and the mammae are four pairs, as in Tamias, Euta- 

 mias, and Scinrus. In C. chrysodeirus, a species of this group from 

 Fort Klamath, Oregon, the mammae are five pairs, and the first upper 

 premolar much larger, in this respect approaching Citelhis citellus 

 (Lihnfeus). 



Life history. — This, the type of the genus Callospennophilus, is an 

 alpine species of the wooded mountain regions of the interior of the 

 United States. In Arizona, its range is nearly coextensive with that 

 of the Arizona chipmunk (EntamAas cinereicollis)., though it descends 

 to a somewhat lower altitude in certain places. It is recorded by Doc- 

 tors Coues and Yarrow from the vicinity of Fort Apache, whence I have 

 traced it along the Mogollon Mountains to the San Francisco Range. 

 In ascending the northwestern extremity of the Mogollon Range, either 

 to the north or east of Fort Verde, it was not met with below 6,000 

 feet. It descends lower in the White Mountain region and occurs at 

 various points in the adjacent Territory of New Mexico. 



The Say ground-squirrel, although generally distributed over the 

 elevated region of its habitat in Arizona, is somewhat colonial, often 

 living in large communities where food is plentiful. As its food con- 

 sists largely of low, green vegetation, it is quite as terrestrial, as the 

 Harris chipmunk, seldom climbing trees, but showing great adaptability 

 for movement amid the rQcks and prostrate timber of its forest home. 

 As one rides through the woodland it is seen perched on stones and 

 fallen timber, or nimbly running about among the branches and decayed 

 trunks of fallen forest monarchs. It often sits erect on its hind feet 

 with its paws dropped by its sides, uttering a high-pitched whistle 

 which is ventriloquial in character, seeming to proceed from the near- 

 est treetops whilst in reality it comes from the ground at a much 

 greater distance. It is quite the reverse of shy, being often so regard- 

 less of your presence as to run almost under your horse's feet, and in 

 camp its curiosity and audacity are boundless. The young are brought 

 forth in June or July in burrows under logs or stones. Its nest is 

 bulky, being composed of dry grass or any soft material at hand, such 

 as wool or hair, if living in the neighborhood of grazing camps. 



When in camp on the western side of Humphreys Peak of the San 

 Francisco Mountains, in June, 1887, these ground-squirrels were found 

 ranging nearly to the timber line, in company with the Mogollon 

 chickaree and the Arizona chipmunk. At Antelope Spring (altitude 

 8,065 feet) in the same region they were annoy ingly familiar, entering 

 my tent during my absence and appropriating my cotton to build nests 

 with and eating whatever scraps of food could be found. They even 

 dared to enter boldly when I was within, .engaged in preparing speci- 

 mens. They would devour the flesh of the birds and mammals skinned, 



