SCIURUS. 109 



Color. Above gray, as are also the sides; outer surface of limbs 

 pale gray; rest of pelage white; orbital ring grayish white; ears 

 grayish; tail above black and white mixed, fringed on sides with 

 white, beneath cinnamon rufous. 



Measurements. Total length (skin), 260-304; tail vertebrae, 254- 

 287; ear: height, 23-25; width at base, 21.5-24. Skull: average of 

 five; basilar length, 55.5 ; palatal length, 28.4; interorbital width, 37.1 ; 

 length of upper molar series, 11.7. 



77. arizonensis (Sciurus), Coues, Am. Nat., 1867, p. 357. Elliot, 

 Syn. N. Am. Mamm., 1901, p. 59. 



collicei Allen, Mon. N. Am. Rod., 1877, p. 738. (nee Rich.) 

 ARIZONA GRAY SQUIRREL. 



Type locality. Fort Whipple, Yavapai County, Arizona. 



Geogr. Distr. State of Nuevo Leon, Mexico (San Pedro Mines, 

 Allen), to Arizona. Texas? 



Genl. Char. Smaller than 5. carolinensis ; tail as long as head and 

 body; soles naked to heel. 



Color. Above mixed gray, black, white, and tawny, the latter 

 predominating; sides and limbs outside grizzled gray and white; 

 beneath and inside of limbs pure white; tail above basally gray and 

 white, remainder black mixed with white and fringed broadly with 

 white, beneath tawny in the center, bordered with black and fringed 

 with white. 



Measurements. Total length, 457.4; tail vertebrae, 241.3; hind 

 foot, 58.4; height of ear, 20.3. Skull: occipito-nasal length, 63; 

 Hensel, 48; zygomatic width, 35; interorbital width, 20; palatal 

 length, 21 ; length of upper molar series, n. 



a. huachuca (Sciurus}, Allen, Bull. Am. Mus. Nat. Hist., 1894, 



p. 349. Elliot, Syn. N. Am. Mamm., 1901, p. 60. 

 HUACHUCA SQUIRREL. 



Type locality. Huachuca Mountains, southern Arizona. 



Geogr. Distr. Huachuca Mountains, Arizona, into State of Sonora, 

 Mexico. 



Genl. Char. Similar to S. arizonensis, but nearly uniform gray 

 above, only a trace of fulvous dorsal stripe. 



Color. Upper parts grizzled gray; dorsal stripe nearly obsolete; 

 sides lighter gray; nape patch pale fulvous; under parts of body and 

 limbs pure white; tail above black sprinkled with white and fringed 

 broadly with white, beneath pale chestnut, bordered with black and 

 broadly fringed with white. 



Measurements. Total length, 540; tail vertebrae, 265; hind foot, 

 70; ear, 34. Skull: average of four; basal length, 53.5 ; palatal length, 



