_Dipus americanus_ Barton, Trans. Amer. Philos. Soc., 4:115, 1799.
_Jaculus americanus_ Wagler, Nat. Syst. Amphibien, 23, 1830.
_Meriones microcephalus_ Harlan, Proc. Zool. Soc. London, p. 1, 1839, based on two specimens from "the farm of Mr. Beck, in Philadelphia County, a few miles northeast of the city [= Philadelphia, Pennsylvania]."
_Jaculus hudsonius_, Baird, Repts. Expl. and Surv. 111, 8 (pt. 1): 433, July 14, 1858 (part--the part from Massachusetts, Connecticut, New York, New Jersey, and Pennsylvania).
_Zapus hudsonius_, Coues, Bull. U. S. Geol. and Geog. Surv. of the territories, 2nd ser. No. 5:260, 1877 (part--the part from Massachusetts, Connecticut, New York, and Pennsylvania); Preble, N. Amer. Fauna, 15:17, August 8, 1899 (part--the part from Peterboro and Waterville, New York, southeastern Massachusetts, Connecticut, New Jersey, Pennsylvania, West Virginia, Maryland, North Carolina, and Ohio).
_Zapus hudsonius americanus_, Batchelder, Proc. New England Zool. Club, 1:6, February 8, 1899; Preble, N. Amer. Fauna, 15:19, August 8, 1899.
_Zapus hudsonius hardyi_, Bole and Moulthrop, Sci. Publ. Cleveland Mus. Nat. Hist., 5:165, September 11, 1942 (part--the part from New York, Ohio, and Pennsylvania).
_Zapus hudsonius brevipes_ Bole and Moulthrop, Sci. Publ. Cleveland Mus. Nat. Hist., 5:168, September 11, 1942, type from Bettsville, Seneca County, Ohio.
_Zapus hudsonius rafinesquei_ Bole and Moulthrop, Sci. Publ. Cleveland Mus. Nat. Hist., 5:169, September 11, 1942 (part--the part from southeastern Ohio), type from Cat Run, extreme southeastern Belmont County, Ohio.
_Type._--No type specimen designated. _Dipus americanus_ was characterized from jumping mice obtained by Barton near the Schuylkill River, a few miles from Philadelphia, Pennsylvania.
_Range._--Southeastern United States and lower peninsula of Michigan; east of central Indiana; from central New York and Massachusetts southward to northern Georgia. See fig. 47. Zonal range: Austroriparian (Lower Austral), Carolinian (Upper Austral), Alleghanian (Transition), and Canadian.
_Description._--Size small; back from near Light Ochraceous-Buff to near Ochraceous-Buff with admixture of black-tipped hair forming distinct dorsal band; sides bright, lighter than back from near Light Ochraceous-Buff to near Ochraceous-Buff; lateral line usually distinct and of color of sides; underparts white, sometimes with slight suffusion of color of sides; tail bicolored, brown to brownish-black above, yellowish-white to grayish-white below; ears narrowly edged and heavily flecked with color of sides; feet white to grayish-white above; skull short; braincase relatively narrow; incisive foramina relatively broad; skull relatively narrow across zygomata; interorbital region relatively broad; distance from incisors to postpalatal notch relatively short; auditory bullae relatively small.