examined. In the autumn of 1950 one of us, Hall, was able to
examine the specimens from Colorado; also, the specimens from Wyoming
accumulated in the past two seasons of field work in Wyoming were
examined by Hall. A result of these studies is the recognition of two
heretofore unnamed subspecies of the northern pocket gopher in
southeastern Wyoming.

Grateful acknowledgment is made of the opportunity to study the
Coloradon specimens in the Biological Surveys Collection of the United
States National Museum, and of the financial assistance from the Kansas
University Endowment Association which permitted the field work in
Wyoming.

Descriptions and names for the two new subspecies are given below:

=Thomomys talpoides rostralis= new subspecies

_Type._--Female, adult, skull and skin, no. 17096 Mus. Nat. Hist., Univ.
Kansas; from 1 mi. E Laramie, 7164 ft., Albany County, Wyoming; obtained
on July 16, 1945, by C. Howard Westman; original no. 320.

_Range._--Southern Wyoming and south in the mountains of Colorado to the
Arkansas River but not including the Colorado River drainage except in
Grand County and part of Routt County.

_Diagnosis._--Size medium (see measurements); upper parts ranging from
between Cinnamon-Rufous and Hazel (capitalized terms are of Ridgway,
Color Standards and Color Nomenclature, Washington, D. C., 1912) in the
eastern part of the range to between Argus Brown and Brussels Brown in
the western part of the range; sides Cinnamon-Rufous; throat whitish;
remainder of under-parts whitish, in many specimens tipped with
Ochraceous-Buff; feet and tail whitish; rostrum long; nasals ordinarily
truncate posteriorly; temporal ridges nearly parallel; interpterygoid
space broadly V-shaped.

_Comparisons._--From _Thomomys talpoides clusius_ (topotypes), _T. t.
rostralis_ differs in: Body longer; color more reddish (lighter with
less brownish and more ochraceous); rostrum both longer and broader,
actually and also in relation to length of the skull; skull broader
interorbitally; upper molariform tooth-row longer; tympanic bullae less
inflated. For comparison with _T. t. attenuatus_ to the east, see the
account of that subspecies.

From _Thomomys talpoides macrotis_ (topotypes) to the southeast, _T. t.
rostralis_ differs in: Body shorter; upper parts slightly more
ochraceous and less grayish; skull averaging smaller in all measurements
except that interorbital region is broader and rostrum and upper
molar