FIELD BOOK OF MAMMALS 



an inch and a half long, but part of this so included under the 

 skin of the rump that the external tail seems very short. 



Little is known of the breeding habits of this animal but it 

 is believed that the young are bom in June and number 

 three to five. 



Family Zapodidae. Jumping Mice 



Form mouse-like; hind legs and tail greatly elongated; 

 internal cheek-pouches present; upper incisors narrow, 

 grooved in front; crown surface of molars with complex, folded 

 pattern; terrestrial in habit; gait saltatorial (when alarmed); 

 soles of feet naked. 



Subfamily Zapodinae. 

 Genus Zapus' 



Dentition: Incisors, {; Canines, §; Premolars, J ; Molars, f = i8. 



Jumping Mouse. — Zapus hudsonius 



and related forms 



Names.^ — Jumping Mouse; Kangaroo Mouse. Plate XXX. 



General Description. — A medium-sized Mouse with greatly 

 elongated hind legs; very long, slender, tapering tail; short 

 forelegs; ear not reaching much beyond surrounding pelage; 

 color yellowish brown above, white below; pelage long and 

 somewhat coarse when compared to that of the White-footed 

 Mice or Meadow Mice; throughout most of its range hiber- 

 nating in winter; when alarmed progressing by long leaps. 



Color. — vSexes colored alike. 



Upperparts (summer) mixed yellowish fawn and black, 

 pelage slate-colored at base and only tips of hairs colored; a 

 dark dorsal band from crown to base of tail where black- 

 tipped hairs predominate; tail above, grayish brown, below, 

 white, a sharp contrast between the two surfaces; feet white; 

 underparts white, sometimes tinged with color encroachment 

 from sides. 



^ For a revision of this genus see E. A. Preble, North American Fauna, 

 No. 15, 1899. 



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