Feb., 1912. Mammals of Illinois and Wisconsin — Cory. 109 



KEY TO OUR SPECIES. 



A. General color largely gray or gray mixed with rusty; under parts white or whitish; 



hairs on tail broadly tipped with white. 



Gray of upper parts more or less mixed with rusty. Occurs in about southern 

 two-thirds of Illinois. ' Southern Gray Squirrel. 



Sciurus carolinensis, p. 115. 



Similar but slightly larger and upper parts clear gray in winter. Occurs in 

 Wisconsin and northern Illinois. Northern Gray Squirrel. 



Sciurus carolinensis leucotis, p. 116. 



B. General color largely tawny gray; under parts not white (usually tawny); hairs 



on tail broadly tipped with tawny or pale rufous. 



Western Fox Squirrel. Sciurus niger rufiventer, p. 109. 



C. General color reddish brown; under parts white; entire length, including tail, 



12 to 14 inches. Red Squirrel. Sciurus hudsonicus loquax, p. 122. 



D. General color black or partly black; color phases of: 



Northern Gray Squirrel. Sciurus carolinensis leucotis, p. 116. 

 or Western Fox Squirrel. Sciurus niger rufiventer, p. 109. 



Subgenus PARASCIURUS Trouessart. 



Premolars — ^; rostrum long and broad; brain case narrow at 

 occiput; nasals relatively broad; molars large. 



Sciurus niger rufiventer (Geoffroy). 

 Western Fox Squirrel. 



Sciurus rufiventer Geoffroy, Cat. Mamm. Mus. d'Hist. Nat., 1803, p. 176. 

 Sciurus occidentalis Aud. & Bach., Proc. Acad. Nat. Sci. Phila., 1841, p. 102. 

 Sciurus vulpinus Lapham, Trans. Wis. State Agr. Soc, II, 1852 (1853), p. 339 



(Wisconsin) . 

 Sciurus magnicaudatus Kennicott, Trans. 111. State Agr. Soc, I, 1853-54 (1855), 



p. 579 (Cook Co., Illinois). 76., Agr. Rept. for 1856, U. S. Patent Office Rept., 



1857, P- 55- 

 Sciurus Sayi Strong, Geol. Wis., Surv. 1873-79, I. 1883, p. 439 (Wisconsin). 

 Sciurus ludovicianus Custis, Barton's Med. & Phys. Journ., II, 1806, p. 47. Allen, 



Proc. Bost. Soc. Nat. Hist., XIII, 1869 (1871), p. 188 (Iowa). Miles, Rept. 



Geol. Surv. Mich. I, i860 (1861), p. 220 (Michigan). Van Hyning & 



Pellett, Proc. Iowa Acad. Sci., XVII, 1910, p. 214 (Iowa). 

 Sciurus niger Garman, Bull. Essex Inst., XXVI, 1894, p. 6 (Kentucky). Herrick, 



Geol. & Nat. Hist. Surv. Minn., Bull. No. 7, 1892, p. 158 (Minnesota). 

 Sciurus niger rufiventer Osgood, Proc. Biol. Soc. Wash., XX, 1907, p. 44. Jackson, 



Proc. Biol. Soc. Wash., XX, 1907, p. 71 (Wisconsin). Hahn, Ann. Rept. 



Dept. Geol. & Nat. Resources Ind., 1908 (1909), p. 466 (Indiana). 



