A New Pocket Gopher (Genus Thomomys), from Eastern Colorado   By: E. Raymond (Eugene Raymond) Hall (1902-1986)

BY

E. RAYMOND HALL

University of Kansas Publications Museum of Natural History

Volume 5, No. 8, pp. 81 85 October 1, 1951

University of Kansas LAWRENCE 1951

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Edward H. Taylor, Robert W. Wilson

Volume 5, No. 8, pp. 81 85 October 1, 1951

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1951

23 7439

A New Pocket Gopher (Genus Thomomys) from Eastern Colorado

By

E. RAYMOND HALL

The pocket gophers of the species Thomomys talpoides in east central Colorado have long been referred to the subspecies Thomomys talpoides clusius Coues with type locality at Bridger Pass, Wyoming. Recently, two subspecies, T. t. attenuatus and T. t. rostralis (see Hall and Montague, Univ. Kansas Publ., Mus. Nat. Hist., 5(3):25 32, February 28, 1951) were named from along the Wyoming Colorado boundary with the result that the populations of Thomomys talpoides in east central Colorado are separated from T. t. clusius of Wyoming by the geographic ranges now ascribed to the recently named T. t. attenuatus and T. t. rostralis . The subspecific identity of the animals from east central Colorado thus is left in doubt. Examination of pertinent materials was made in the expectation that the names Thomomys talpoides macrotis F. W. Miller (Proc. Colorado Mus. Nat. Hist., 9:41, December 14, 1930) and Thomomys talpoides cheyennensis Swenk (Missouri Valley Fauna, 4:5, March 1, 1941) would apply to the specimens, the identity of which is in doubt. This examination discloses instead, as set forth in more detail below, that neither of the two names mentioned immediately above does apply; the Coloradan specimens in question are referable to an heretofore unrecognized subspecies which may be named and described as follows:

Thomomys talpoides retrorsus new subspecies

Thomomys clusius , Warren, The Mammals of Colorado, G. P. Putnam's Sons, New York, p. 80, 1910; Cary, N. Amer. Fauna, 33:132, August 17, 1911.

Thomomys talpoides clusius , Bailey, N. Amer. Fauna, 39:100, November 15, 1915; F. W. Miller, Proc. Colorado Mus. Nat. Hist., 9:41, December 14, 1930; Warren, The Mammals of Colorado, Univ. Oklahoma Press, Norman, p. 162, 1942.

Type. Male, subadult, skull and skin, No. 69840 Biological Surveys Collection, U. S. Nat. Hist.; from Flagler, Kit Carson County, Colorado; obtained on November 26, 1894, by Clark P. Streator; original No. 4460.

Range. Western end of the Arkansas Divide in Colorado from eight miles south of Seibert westward to Colorado Springs

Diagnosis. Size medium (see measurements); upper parts grayish brown; underparts lighter; skull small; tympanic bullae moderately inflated and angular anterolaterally; interpterygoid space narrowly U shaped; pterygoid hamuli without transverse enlargement; nasals truncate posteriorly; premaxillary tongues projecting posteriorly behind nasals for distance of eight tenths (0.5 1.1) of a millimeter.