52 The Mammals of Colorado 
preference. It is found on the prairies, living in abandoned 
prairie-dog or badger holes, or living about the rabbit brush, 
sage-brush, or greasewood so common in many localities. 
It is also found among rocks on the hillsides, and the ledges 
which often border the streams and gulches, so that after all 
it may be said to be rather indiscriminate in its choice of a 
residence. 
Sylvilagus auduboni warreni (for E. R. Warren). 
Colorado Cottontail. 
Sylvilagus auduboni warreni Nelson, Proc. Biol. Soc. Wash., 
XX., p. 83 (1907). 
Type locality. — Coventry, Montrose County, Colorado (C. H. 
Smith, January 4, 1907). 
Measurements. — Total length, 15.5; tail vert., 2.0; hind foot, 
3.8; ear from notch, dried skin, 2.75. 
Description. — (From a specimen taken at Coventry, Dec. 15th.) 
Back a dark pinkish buff much mixed with black ; rump gray with 
much black; sides buffy, rather gray next back, but clear buff 
adjoining belly; upper part of tail gray, mixed with blackish; 
nape and front legs rufous, quite dark; pectoral band pinkish 
buffy; rest of underparts white. Some specimens have so much 
black on the back that the posterior portion might almost be said 
to be that color, it is so much in evidence. Specimens from Cortez, 
Montezuma County, in my collection, have the rufous of the neck 
and feet very dark and intense. 
The skull is as in bailey i. 
The darker color distinguishes this species from baileyi, which 
has a similar skull, and while pinetis, the only other whose range 
approaches it, is often quite dark, the two are readily distinguished 
by cranial characters, and especially by the difference in the size 
of the bullae, warreni having much the larger, and also longer ears. 
Distribution. — The Colorado cottontail is found, according to 
Nelson, in "southwestern Colorado, and adjacent parts of Utah, 
New Mexico, and Arizona." In Colorado we have it from Mon- 
trose, Montezuma, San Miguel, Mesa, Delta, Garfield, Conejos, 
Costilla, and Saguache Counties. It ranges from below 5,000 to 
8,000 feet, mainly in the Upper Sonoran, but extending into 
both Lower Sonoran and Transition. It has been found in the 
valley of the Grand River up at least as far as Rifle, and is separated 
from the range of the Wyoming Cottontail to the north by the divide 
