134 



TAMIAS. 



35. Tamias. Chipmunks. 



J. A. Allen. A review of some of the North American Ground 

 Squirrels. Bull. Am. Mus. Nat. Hist., 1890, p. 45. 



Tamias Illig., Prodr. Syst. Mamm. et Av., 1811, p. 83. Type 



Sciurus striatus Linnaeus. 



Tenotis Rafin., Am. Month. Mag., i, 1817, p. 362. 

 Eutamias Trouess., Le Nat., n, 1880, p. 86. 



Tail short, not bushy, narrow; cheek pouches large; ears without 

 tufts. Skull narrow anteriorly; superior outline convex; postorbital 

 processes slender, directed backward and downward; antorbital 

 foramen oval; zygomata expanded and depressed anteriorly; upper 

 premolars either two or one. 



FIG. 22. TAMIAS OBSCURUS. 

 Field Columbian Mus. Coll. Nat. size. 



UPPER TOOTH ROW. 

 Enlarged 8 times. 



LOWER TOOTH ROW. 

 Enlarged 8 times. 



A. Eutamias. 



Skull with superior outline highest over parietals ; orbital foramen 

 a narrow, slit-like opening; rostrum compressed; nasals short, slightly 

 narrowed posteriorly; pterygoid fossa long and wide; audital bullae 

 large. 



