134 TAMIAS. 
35. Tamias. Chipmunks. 
os) 
[= P24 = of 3 M = ee-on ee: 
[=I I—I I—I 3 
ios) 
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, pp.) Sg.ueuyee 
Sciurus striatus Linneus. 
Tenotis Rafin., Am. Month. Mag., I, 1817, p. 362. 
Eutamias Trouess., Le Nat., 1, 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. 
Fic. 22. TAMIAS OBSCURUS. 
Field Columbian Mus. Coll. Nat. size. 
UPPER TOOTH ROW. LOWER TOOTH ROW. 
Enlarged § times. Enlarged § 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 bulle 
large. 
