102 CITELLUS. 



mixed with white hairs and narrowly edged with white, beneath sil- 

 very white at base, remainder buff mixed with black, bordered and 

 tipped with black and narrowly fringed with white. Ear ver\^ small, 

 similar in color to the back. 



Measurements. Total length, 252; tail vertebrae, 89; hind foot, 

 35; ear, 8.5. Skull: total length, 36; occipito-nasal length, 35; 

 Hensel, 30; zygomatic width, 23; interorbital constriction, 9.5; 

 palatal length, 17 ; length of nasals, 12 ; length of upper tooth row, 7 ; 

 length of mandible, 2.5; of lower tooth row, 7. 



195. Citellus tereticaudus (Baird). 



S pernio philus tereticaudus Baird, N. Am. Mamm., 1857, p. 315. 

 Elliot, Syn, N. Am, Mamm., F. C. M. Pub., 11, 1901, p. 98, 

 Zool. Ser. 

 Citellus tereticaudus Elliot, Mamm. Middle Amer. & W. Indies, 

 F. C. M. Pub., IV, Pt. I, 1904, p. 144. Zool. Ser. 

 Round-tailed Spermophile. 



Type locality. Old Fort Yuma, San Diego County, California. 

 Geogr. Distr. Central California to Tucson Plain, Arizona; Lower 

 California and State of Sonora, Mexico. 



a. Citellus tereticaudus mohcn'ensis (Merriam). 

 Spermophilus mohavensis Merr., N. Am. Faun., No. 2, 1889, p. 15. 



Elliot, Syn. N. Am. Mamm., F. C. M. Pub., 11, 1901, p. 98. 



Zool. Ser. 

 Citellus tereticaudus mohavensis Elliot, Pub. Field Columb. Mus., 



Ill, 1903, p. 291. Zool. Ser. 

 Mohave Desert Spermophile. 



Type locality. Mohave River, San Bernardino County,. California. 

 Geogr. Distr. Mohave Desert, California. 



b. Citellus tereticaudus sonoriensis (Ward). 

 Spermophilus sonoriensis Ward, Amer. Nat., xxv, 1891, p. 158. 

 Citellus tereticaudus sonoriensis Elliot, Mamm. Middle Amer. & 



W. Indies, F, C. M. Pub., iv, Pt. i, 1904, p. 144. Zool. Ser. 

 Sonoran Spermophile. 



Type locality. Hermosillo, State of Sonora, Mexico. 

 Geogr. Distr. State of Sonora. Range unknown. 



196. Citellus perotensis (Merriam). 



Spermophilus perotensis Merr., Proc. Biol. Soc. Wash., viii, 1893, 



p. 131. 

 Citellus perotensis Elliot, Mamm. Middle Amer. & W. Indies, 



F. C. M. Pub., IV, Pt. I, 1904, p. 145. Zool. Ser. 



