SCIURID^ 69 



Sierra Nevada and eastward to the Panamint Mountains, but are 

 common in few places. They prefer rocky hillsides bordering 

 valleys. They are a desert race of the Californian Ground- 

 Squirrel, with otherwise similar habits. 



In the Providence Mountains, in the eastern part of the 

 Mohave Desert, are a few Ground-Squirrels that I suppose are 

 some form of Citcllus gramumrxis, but I have no examples and 

 cannot place them positively. As near as I remember the ap- 

 pearance of those that I sent the National Museum the whitish 

 neck patches were indistinct and confluent and the hind parts were 

 tinged with reddish brown. They are about the size, general 

 appearance and habits of the California Ground-Squirrel. 



Subgenus Xerospermophilus. (Dry — spermophile. ) 

 Ears rudimentary; tail various in length and shape, usually 

 narrow and one^fourth to one-half as long as head and body; 

 pelage usually plain, sometimes striped ; skull wide and strong ; 

 size small. 



Citellus tereticaudus Baird. (Round-tail.) 



ROUND-TAILED GROUND-SQUIRREL. 



Winter pelage; above pale brownish cream buff; below 

 creamy white; hairs comparatively long and soft. Summer pel- 

 age; above from nose to tail pinkish drab; below, sharply out- 

 lined along the sides, white; hairs short and coarse. Young; 

 similar to winter adult. 



Length about 240 mm. (9.50 inches) ; tail vertebrae 95 

 (3.75); hind foot 35 (1.40); ear a mere rim. 



Type locality, old Fort Yuma, California. 



Round-tailed Ground-Squirrels inhabit soutlieastern California. 



southern Arizona, northwestern Sonora and northeastern Lower 



California. In California they are most common in the lower 



Colorado Valley and in a few places in the Colorado Desert, 



