inches. There are six species of Pocket Mice recorded as actually having 

 been taken in Colorado, as follows: The Buff-bellied Pocket Mouse, 

 Perognathus fasciatus inf raluteus ; the Plains Pocket Mouse, P. flavescens; 

 the Black-eared Pocket Mouse, P. apache melanotis; the Colorado Pocket 

 Mouse, P. a. caryi; Baird's Pocket Mouse, P. flavus, and the Kansas Pocket 

 Mouse, P. hispidus paradoxus. In color they are various shades of buff, 

 with many black or blackish hairs mingled in the back. They are found 

 in the prairie and other dry regions of the state. 



KANGAROO RATS. 



Kangaroo Rats are an exclusively western group of mammals, ranging 

 from Oregon well south into Mexico, and always confined to more or less 

 arid regions. Like the Pocket Mice and Pocket Gophers they have external 

 cheek pouches, opening on the outside of the mouth, not on the inside as 

 in the case of the chipmunks and similar animals; these pouches are lined 

 with hair and are used for carrying food to the nests and storage places. 

 Their hind legs are greatly elongated, and the tail is extremely long, with 

 a tuft or pencil at the tip, and is well-haired its full length. All the 

 species have certain markings in common, these being more or less dis- 

 tinct crescentic black facial lines, white spot over eye and behind ear, and 

 a white stripe across the thigh. The upper parts are buffy, with more 

 or fewer black hairs; the under parts and feet white. The tail has a dark 

 stripe above and another below, with white between. The pencil is dark. 

 The total length is about ten inches, the tail about six. 



We have four forms in Colorado, the Mountain or San Luis Kangaroo 

 Rat, Perodipus ordii montamis; the Moki Kangaroo Rat, P. o. longipes; 

 the Wyoming Kangaroo Rat, P. o. luteolus; and Richardson's Kangaroo 

 Rat, P. o. richardsoni. They inhabit many of the lower arid portions of 

 the state. 



The habits of these animals are very interesting. While mainly 

 twilight or nocturnal, as their large eyes would lead one to suspect, yet 

 they do occasionally go abroad by daylight, and the individual whose 

 picture is shown here was captured in the daytime in the San Luis Valley 

 where it was out among the greasewood and sage brush. Two of us had no 

 difficulty in running it down and taking it in our hands. It did not appear 

 to leap in trying to escape, but rather to run. They live in burrows, 



No. 13. Mountain Kangaroo Rat, Perodipus montanus. 

 22 



