The Mammals of Colorado 
Habits. — These seem to be similar to those of C. lateralis^ 
of which it is an arid land form, living among the sage brush 
and greasewood of that region. In its color and habitat it is 
a corresponding form to the Least Chipmunk, which also 
inhabits the same region, though the present species goes 
farther up among the pines than the latter does. It did not 
seem to be particularly common anywhere. 
Genus EUTAMIAS (Grk. eu, well or good + tamias, a steward) 
Eutamias Trouessart, Cat. mamm. viv. et joss., p. 86 (1780). 
Type Tamias asiaticiis. 
This genus contains the bulk of the chipmunks which are dis- 
tinguished by possessing internal cheek pouches and a characteristic 
pattern of coloration consisting of a series of five dark and four 
light dorsal longitudinal stripes. The tail is rather shorter 
and less bushy than in the squirrels, and the ears never have 
tufts. 
The skull is slender and light, and has very slender, backwardly 
directed postorbital processes, and an oval interorbital foramen, 
and the anterior premolar, if present, is small and functionless. 
Dentition: i. \ ; pm. m. J X 2 = 22 or 24. 
I 
The species of this genus are found all over North America 
and northern Asia. In Elliot's Check-list 25 North American 
species are mentioned, of which 5 species and 3 subspecies 
inhabit Colorado. 
Key of the Species 
A. Larger; total length over 8.25. 
a. Grayish ; dorsal stripes not distinct. E.dorsalisutahensis, p. 171 
b. Stripes distinct; ground color of upper parts dull dark chest- 
nut; dark stripes distinctly black in midsummer pelage. 
E. quadrivittatus, p. 173 
c. Stripes distinct; color very pale, general tinge pale rusty 
rufous. E. quadrivittatus animosus, p. i 74 
d. Stripes distinct ; ground color of upper parts hght bright 
chestnut; dark dorsal stripes not black. 
E. hopiensis, p. 1 75 
