324 VERTEBRATE ANIMALS OF THE UNITED STATES 



M. megacephalus Merr. Color yellowish brown; under parts white; 

 tail bicolor, terminal third blackish; length 150 mm.; tail 80 mm.; hind 

 foot 24 mm.: northern California and Nevada and southeastern Oregon. 



Family 4. Zapodidae. — Jumping mice. Small mouse-like rodents 

 with very long hind legs and tail and short fore legs, which 

 progress by leaping; ears and eyes large; upper incisors much curved, 

 compressed and deeply sulcate: 2 genera and about 15 species, in the 

 northern United States and Canada; i species in China. 



Key to the Genera of Zapodidae 



ai One very small premolar present i. Zapiis. 



a2 No premolars present 2. NapccozapcE. 



I. Zapus Coues. Tail longer than the rest of the body; hind foot 

 nearly half as long as the head and body; dentition i/i, 0/0, i/o, 3/3; 

 premolars very small: about 10 species, which live in meadows and make 

 nests in burrows in the ground or in tufts of grass or hollow logs; 

 progress is made by leaps, which may be 10 feet in length; they hiber- 

 nate in the winter; i or 2 litters annually of 5 or 6 young each. 



Z. hudsonius (Zimmermann) . Meadow jumping-mouse. Body 

 about the size of a house-mouse; color yellowish brown above, wdth a 

 broad dark dorsal band; white beneath; tail tipped with brown and 

 bicolor; feet white; length 217 mm.; tail 132 mm.; hind foot 30 mm.: 

 eastern and central States; westward to the Rockies and Alaska. 



Subspecies of Z. hudsonius 



Z. h. hudsonius (Zimm.). Hudson Bay to Xew Jersey, and in the 

 mountains to North Carolina; west to Iowa and Missouri and Alaska. 



Z. h. americanus (Barton). Size small; length 191 mm.: from 

 Raleigh, N. C. along the coastal plain to Connecticut. 



Z. h. Campestris Preble. Size large; length 222 mm.: Great Plains 

 from Manitoba to Nebraska; westward to Colorado and Wyoming. 



Z. prince ps Allen. Color yellowish brown, with a broad dark dorsal 

 band; length 245 mm.; tail 147 mm.; hind foot 32 mm.: Rocky Moun- 

 tain region from New Mexico to Alberta. 



Subspecies of Z. princeps 



Z. p. oregonus Preble. Color lighter; length 250 mm.: Blue Moun- 

 tains, Oregon. 



