brown, and feet blackish. Tail above blackish, with white exterior 

 border, beneath pale gray in center, bordered with black and fringed 

 with white. 



Measurements. Total length, 545 ; tail vertebral', 285; hind foot, 75. 



b.—anthonyi. {Sciunis), Mearns, Proc. U. S. Nat. Mus. , 1S97, p. 501. 



Type locality. Campbell's Ranch, Laguna, San Diego County, 

 California. 



Geogr. Distr. Interior of Southern and Lower California. 



Genl. Char. Similar to .S'. i:^riseui, but faintly suffused with 

 brown on back. 



Color. Above, gray suffused with yellowish brown; orbital ring 

 and under parts white; feet yellowish brown, gray and black mixed, 

 edged with white; ears at base tawny ochraceous. Tail gray above 

 tipped with white, beneath gray bordered with black and fringed with 

 white. 



Measurements. Total length, 540; tail vertebr;i', 270; hind foot, 

 79; ear from crown, 28. 



D. Otosciurus, Nelson. 



Premolars, ^. Skull very broad, rather short; brain case 

 depressed posteriorly, inflated laterally; rostrum compressed; nasals 

 narrowing posteriorly and extending beyond the premaxillaries. 

 Molar series very heavy. 



75. aberti. {Sciums), Woodh. Proc. Acad. Nat. Scien. Phil., 1852, 

 p. 220. 



(lorsalis, Woodh. (nee Gray), Proc. Acad. Nat. Scien. Phil., 1852, 

 p. 110. 



castanonoius, Baird, Mamm. N. Am., 1857, p. 266. 



Type locality. San Francisco Mountains, New Mexico. 



Geogr. Distr. Arizona, New Mexico and mountains of Colorado. 



Gen/. Char. Above grizzly gray, median stripe chestnut. 



Co/i'r. Upper parts grizzled bluish gray; broad dorsal stripe 

 chestnut; black lateral stripe, feet and under parts white; ear tufts 

 glossy black tinged with chestnut. Tail above blackish fringed with 

 white: beneath pure white. 



Measurements. Total length, 521; tail vertebrre, 229; hind foot, 

 62; ear, 55. 



o.—concolor. {.Sciurus), True, Proc. U. S. Nat. Mus., 1894, p. 241. 



'Type locality. Loveland, Larimer County, Colorado. 



Geogr Distr. Northeastern Colorado. 



Genl. Char. Similar to .S". aberti, but no chestnut on back; tail 

 same on both sides. 



