126, 60137) were trapped at localities 6, 10, 12, 14, and 15.

=_Erethizon dorsatum epixanthum_= Brandt.--A Porcupine skull was seen
in the nest of a wood rat by John M. Legler at locality 3 on July 2. On
June 20 a porcupine was seen at locality 12. No specimen was obtained.

=_Mustela frenata nevadensis_= Hall.--Seven Long-tailed Weasels
(60138-60143, 70152) were taken at localities 1, 4, 7, 8, 13, and 14.
Four are males and three are females. Some of these were attracted by
"squeaking" noises and then shot.

=_Taxidea taxus taxus_= (Schreber).--One adult male Badger (60144) was
found dead; the skull and baculum were saved. The subspecific
identification is on geographic grounds, and is tentative. In this area
_T. t. taxus_ and _T. t. fippsi_ may intergrade.

=_Mephitis mephitis estor_= Merriam.--One Striped Skunk (60145) of
unknown sex was found dead in the cellar of a cabin at locality 10.

=_Odocoileus hemionus hemionus_= (Rafinesque).--Mule Deer were observed
at locality 15; no specimen was obtained.

DISCUSSION

The species here reported from the Grand Mesa may be placed according
to their geographic ranges and their restriction to certain habitats in
two groups:

BOREAL.--Each of the 12 species listed below is of northern
distribution, is dependent, at the latitude of Colorado, upon the
habitat provided by areas of high altitudes, and is near its southern
zonal limit on the Grand Mesa. The 12 species are: _Sorex cinereus_,
_Sorex palustris_, _Sorex vagrans_, _Ochotona princeps_, _Lepus
americanus_, _Marmota flaviventris_, _Spermophilus lateralis_,
_Clethrionomys gapperi_, _Phenacomys intermedius_, _Microtus
longicaudus_, _Microtus montanus_, and _Zapus princeps_. _Thomomys
talpoides_ may be considered in this category also, although it is less
restricted in range and habitat than most of the other species listed
as boreal. These thirteen species make up almost half of the
twenty-seven species known from the Grand Mesa.

WIDE-SPREAD.--Species in this category are those that are widely
distributed in the western United States and that occur in Colorado in
both the mountains and the lower more arid intermontane areas. Some of
these species are differentiated into subspecies, one of which
inhabits the mountains and another the lowlands. Wide-spread species
that do not have subspecies in the lowlands different than the
subspecies in the mountains or that are represented by too little
material from the Gra