MAMMALS ^^^ 



D. m. mortivallis Elliot. Color very pale: Death Valley, California. 



D. m. nevadensis Merr. Color pale; tail shorter; hind foot longer: 

 Washoe County, Nevada. 



D. in. nitrakis Merr. Color intense ochraceous: Inyo County, 

 California. 



D. m. nitratoides Merr. Dusky crescent over nose: Tulare County, 

 CaHfornia. 



D. calif ornicus Merr. Color dark sepia brown; tail long; length 302 

 mm. ; 183 mm. ; hind foot 43 mm. : northern California. 



D. deserti Stephens. Color pale yellowish brown; mastoid region 

 enormously inflated; length 322 mm.; tail 192 mm.; hind foot 48 mm.: 

 southern California. 



D. elator Merr. Back clay-color ; length 290 mm. ; tail 1 70 mm. ; hind 

 foot 45 mm.: northern Texas and southern Oklahoma. 



D. spectahilis Merr. Color ochraceous buff; length 350 mm.; tail 

 211 mm.; hind foot 52 mm.: southern Arizona. 



D. parvus Rhoads. Color buffy gray; tail-pencil sooty brown ; length 

 248 mm.; tail 154 mm.; hind foot 35 mm.: southern California. 



4. Microdipodops Merriam. Kangaroo mice. Size very small; 

 penicillate, four-striped tail lacking; mastoid region very much inflated: 

 3 species. 



M. calif ornicus Merr. Color olivaceous; under parts snow white; 

 length 160 mm.; tail 92 mm.; hind foot 25 mm.: southern California. 



M. pallidus Merr. Color pale buff; tail with a dark tip; length 171 

 mm.; tail 102 mm.; hind foot 25 mm.: Churchill County, Nevada. 



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

 tail bicolor; length 150 mm.; tail 80 mm.; hind foot 24 mm.: northern 

 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. Zapus. 



Sii No premolars present 2. Napceozapus 



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, ^/t,; 

 premolars very small: about 8 species, which live in meadows and make 

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



