_Jaculus hudsonius_, Baird, Repts. Expl. and Surv. 111, 8 (pt. 1):433, July 14, 1858 (part--the part from Platte River, Nebraska, and Cass County, Missouri). _Zapus hudsonius_, Coues, Bull. U. S. Geol. and Geog. Surv. of the Territories, 2nd ser. No. 5:260, 1877 (part--the part from Platte River, Nebraska). _Zapus hudsonius campestris_ Preble, N. Amer. Fauna, 15:20, August 8, 1899 (part--the part from Columbus in Nebraska and Jackson County in Missouri). _Type._--Male, adult, No. 22953, Univ. Kansas Mus. Nat. Hist.; NW corner sec. 4, T. 12S, R. 20E, 5-1/2 mi. N, 1-3/4 mi. E Lawrence, Douglas County, Kansas; obtained on May 4, 1948, by E. Lendell Cockrum and Rollin H. Baker, original No. 916 of Cockrum. _Range._--Southern South Dakota, Nebraska, Kansas, Missouri, and northeastern Oklahoma. See fig. 47. Zonal range: Upper Austral (Upper Sonoran and Carolinian). _Description._--Size small; back near Cinnamon-Buff with admixture of dark-tipped hair forming distinct, broad, dorsal band; sides bright Cinnamon-Buff with sparse mixture of dark-tipped hair; lateral line usually distinct, of clear Cinnamon-Buff; belly white, sometimes with suffusion of color of sides, tail bicolored, brownish to brownish-black above, grayish-white to yellowish-white below; ears dark, narrowly edged with color of sides; feet white to grayish-white above; mastoid region relatively narrow; maxillary tooth-row relatively short; zygomata relatively short; zygomatic arch relatively broad; interorbital region relatively broad; auditory bullae relatively small and narrow; lateral margins of nasals not constricted posteriorly. _Comparisons._--From _Zapus hudsonius preblei_, _Z. h. pallidus_ differs as follows: Coloration brighter and richer, more buff, less black; zygomatic arch more broadly bowed; condylobasal length averaging less; braincase narrower; interorbital region broader; incisive foramina shorter. For comparisons with _Zapus hudsonius pallidus_ and _Zapus hudsonius intermedius_ see accounts of those subspecies. _Remarks._--The characters that distinguish this jumping mouse from neighboring kinds are relatively stable throughout most of its geographic range. _Zapus hudsonius pallidus_ is one of the best defined subspecies of _Z. hudsonius_.