w.

The following are measurements of a series from the U. S. Range Reserve:

[Transcriber note: Next line was corrected per erratum. The
original text was of the following paragraph (_Averages for 17
adult females: Total length, 326.4 millimeters_).]

Average measurements of 30 adult specimens of both sexes: Total length,
326.2 millimeters (349-310); tail vertebrae, 188.4 (208-180); hind foot,
49.5 (51-47); the average weight of 29 adult specimens of both sexes was
114.5 grams (131.9-98.0).

Averages for 17 adult females: Total length, 326.4 millimeters
(349-310); tail vertebrae, 188.8 (208-179); weight (16 individuals),
113.7 (131.9-98.0); excluding pregnant females, 13 individuals averaged
112.9 grams (131.9-98.0).

Averages for 13 adult males: Total length, 326 millimeters (345-311);
tail vertebrae, 187.8 (202-168); weight, 116.8 grams (129-100).

There appears to be no significant difference in the measurements and
weights of males and females, with the possible exception of the
comparison of adult males and adult nonpregnant females.

OCCURRENCE.

GENERAL DISTRIBUTION.

_Dipodomys spectabilis spectabilis_ is found in southeastern Arizona, in
northwestern, central, and southern New Mexico, in extreme western
Texas, in northern Sonora, and in northern and central Chihuahua (Fig.
1). A subspecies, _D. s. cratodon_ Merriam, has been described from
Chicalote, Aguas Calientes, Mexico, the geographic range of which lies
in central Mexico in portions of the States of Zacatecas, San Luis
Potosi, and Aguas Calientes.

HABITAT.

In the Tucson region _spectabilis_ is typically a resident of the Lower
Sonoran Zone. This is perhaps the principal zone inhabited over its
entire range, but the animal is often found in the Upper Sonoran also,
and in the Gallina Mountains of New Mexico Hollister found it invading
the yellow pine Transition where the soil was dry and sandy and the pine
woods of open character. The same observer found it common in grassy and
weed-grown parks among the large junipers, pinyons, and scattering
yellow pines of the Bear Spring Mountains, N. Mex. Bailey calls
attention to the fact that the animal apparently does not inhabit the
lower half of the Lower Sonoran Zone, as it extends neither into the Rio
Grande Valley of Texas nor the Gila Valley of Arizona. In extreme
western Texas it is common at the upper edge of the arid Lower Sonoran
Zone, and in this region does not e