White-tailed Prairie Dog 
155 
Habits. — Very similar to those of the other species. In 
Routt County the old males were found to be extremely fat 
in late June, and presented a truly aldermanic appearance 
as they sat on their mounds barking at the passer-by. They 
were then in excellent pelage, while the adult females were 
still in worn winter coat, and not at all fat, not having yet had 
time to recuperate from their labors in raising families. 
Genus CITELLUS (Lat., diminutive of citus, swift) 
Citellus Oken, Lehrb. der Naturg., ii., p. 842 (1816). Type, 
Citellus citellus. 
Squirrel-like animals of terrestrial and burrowing habits with 
tails of varying length but never quite so bushy as in the true 
squirrels; cheek pouches always present; skull with somewhat 
slender postorbital processes backwardly directed; anteorbital 
foramen oval or circular with a marked tubercle on its outer lower 
border; dentition i., \; pm., f;m.;f X 2 = 22. 
The members of this genus are distributed over the whole 
of the northern temperate regions of both hemispheres from 
eastern Europe across northern Asia, to North America. 
Forty-three North American species are recognized by 
Elliot in his Check-list, distributed chiefly over the western 
two thirds of the country from Alaska to the state of Vera 
Cruz in Mexico. Up to the present ten species and sub- 
species have been found within the limits of Colorado. 
Key of the Species 
A. Size smaller, total length under 12.0; tail shorter, less than 
f the length of the body, 
a. No lateral or other stripes. 
a'. Uniform speckled black and yellowish above; tail short, 
less than ^ the length of the body. C. e lagans, p. 1 56 
b'. Hinder part of the body indistinctly spotted with white, 
each spot bordered posteriorly with black; tail longer, 
about i the length of the body. 
sl". General color above cinnamon brown, well spotted, 
extending to shoulders. C. spilosoma major, p. 157 
