64 The Mammals of Colorado 
Type locality.— Florida, La Plata Co., Colo. 
Measurements. — Total length, 9.5; tail vert., 5.75; hind foot, 
Description. — (From a specimen taken at Meeker, Rio Blanco Co., 
Jul\^ 7th.) Sides ochraceous buff mixed with blackish, except a clear 
FIG. 24. ROCKY MOUNTAIN JUMPING MOUSE, ZapUS pHucepS 
About i life size. E. R. Warren, Photo. 
narrow lateral line next the white underparts; dorsal area very 
dark, the black hairs largely predominating; under parts white 
with but a faint tinge of buffy in some places; tail bicolor, dusky 
above, grayish white below. The larger size, darker dorsal area, 
whiter underparts, and whitish underside of tail serve to distinguish 
it from Z. h. campestris. 
Distribution. — The Rocky Mountain Jumping Mouse is a mountain 
form, and has been reported from Alberta, British Columbia, 
Montana, Idaho, Wyoming, Colorado, and New Mexico. In Colo- 
rado it is recorded from La Plata, Saguache, Costilla, Boulder, 
Gilpin, Gunnison, Routt, and Rio Blanco Counties. Its range 
of elevation as known to me is from 6,000 to 10,000 feet. It is no 
doubt found through all the mountainous portion of the State. 
Family HETEROMYIDiE 
Rodents with large fur-lined cheek pouches opening outside 
