Zapus major Preble, N. Amer. Fauna, 15:24, August 8, 1899, type from Warner Mt’s, Lake County, Oregon.

Zapus princeps major, Hall, Univ. California Publ. Zool., 37:10, April 10, 1931.

Zapus nevadensis Preble, N. Amer. Fauna, 15:25, August 8, 1899, type from Ruby Mt’s, Elko County, Nevada.

Zapus princeps nevadensis, Hall, Univ. California Publ. Zool., 37:10, April 10, 1931.

Zapus princeps palatinus Hall, Univ. California Publ. Zool., 37:8, April 10, 1931, type from Wisconsin Creek, 7800 ft., Toyabe Mt’s, Nye County, Nevada.

Zapus princeps princeps, Anthony, Bull. Amer. Mus. Nat. Hist., 33:17, March 17, 1913.

Type.—Male, adult, skin and skull; No. 78156, U. S. Nat. Mus. Biol. Surv. Coll.; Elgin, Blue Mountains, Union Co., Oregon; obtained on May 29, 1896, by Edward A. Preble, original No. 959.

Range.—Southeastern Washington, eastern Oregon east of Cascades, northeastern California, central and northeastern Nevada, and southwestern Idaho. See [fig. 46]. Zonal range: Transition and Canadian.

Description.—Size large; back from near Light Ochraceous-Buff to near Cinnamon-Buff, usually overlaid with black hairs forming broad dorsal band, which in some individuals is almost black; sides lighter than back, from near Light Pinkish-Cinnamon to near Cinnamon-Buff and Ochraceous-Buff, often with black hairs interspersed; lateral line faintly marked or wanting; belly pure white; tail bicolored, grayish-brown above and grayish-white to yellowish-white below; ears dark, edged with color of sides; palatal bridge long; interorbital region broad; inferior ramus of zygomatic process of maxillary usually with median projection; auditory bullae relatively small; incisive foramina greatly enlarged posteriorly; tooth-rows divergent anteriorly; nasals narrow posteriorly.

Comparisons.—From Zapus princeps curtatus, Z. p. oregonus differs as follows: Size averaging larger; upper parts darker; tooth-rows more divergent [410] anteriorly; palatal bridge longer; mastoid region broader; incisive foramina relatively wider posteriorly.