246 Fretp Museum or Naturat History — Zodzoey, Vor. XI. 
Family ZAPODIDE. Jumping Mice. 
The Zapodide,* or Jumping Mice, are a semi-boreal family com- 
prising two well marked subfamilies — Zapodine and Sminthine; the 
latter, however, is not represented in North America. The subfamily 
Zapodine contains three genera, two of which are North American and 
which include about 20 species and subspecies, but so far only a single 
species, the Hudson Bay Jumping Mouse, 
Zapus hudsonius, has been taken within our 
limits. It is probable, however, that the 
t; Woodland Jumping Mouse, Napeozapus in- 
Zabus. ; signis, occurs in northern Wisconsin, as it has 
been taken in the Michigan peninsular. The 
two genera may be briefly characterized as 
follows: 
A small upper premolar present; tail not 
tipped with white; teeth 18. Genus Zapus. 
iMac eninge Upper premolar absent; tail tipped with 
white; teeth 16. Genus Napeozapus. 
Subfamily ZAPODIN &. 
Genus ZAPUS Coues. 
Zapus Coues, Bull. U. S. Geol. Surv. Terr., 2nd ser., I, 1875, p. 253. 
Type Dipus hudsonius Zimmermann. 
Tail very long and slender; hind legs greatly elongated; antorbital 
foramen large and oval; upper premolar present but small; crowns of 
molars with enamel much folded; upper incisors sulcate (grooved) and 
brownish orange in color; hind foot with 5 toes, each with separate 
metatarsal; fore foot with 4 functional toes with perfect claws and a 
rudimentary thumb with a flat nail; pelage rather coarse; internal 
cheek pouches present but small. 
Dental formula: I. ay C.—, Pig 2 i 2 
I-1 o-o0 o-o0 3-3 
*For reasons for recognizing the family Zapodide as distinct from Dipodide, 
see Lyon, Proc. U. S. Nat. Mus., XXIII, 1901, p. 659. 
