346 VERTEBRATE ANIMALS OF THE UNITED STATES 



C. castanurus (Merr.). Head and shoulders chestnut; length 284 

 mm.; tail 92 mm.; hind foot 43 mm.: Wasatch Mountains, Utah. 



C. cinerascens (Merr.). Head and shoulders chestnut; color of back 

 grizzled gray; length 322 mm.; tail 108 mm.; hind foot 44 mm.: Idaho, 

 Montana and northwards. 



C. wortmani (Allen). Color yellowish gray, mixed with black; 

 neck and shoulders deep ochraceous; length 280 mm.; tail 95 mm.; hind 

 foot 42 mm.: Wyoming and northwestern Colorado. 



5. Ammospermophilus Merriam. Antelope chipmunks; ground 

 squirrels. Size small; one whitish lateral stripe; tail very short and 

 carried curved over the back; skull very broad; dentition 1/1,0/0, 2/1, 

 3/3:4 species, in arid plains; several litters of young raised a year, of 

 from 4 to 12 each. 



A. leucurus (Merr.). Color grizzled yellowish brown above and 

 yellowish white beneath; tail grizzled blackish above and white below; 

 length 209 mm.; tail 69 mm.; hind foot 38 mm.: southern California, 

 and Arizona; Sonoran zone; in deserts. 



Subspecies of A . leiicunis 



A. I. cinnamomeus (Merr.). Upper parts uniform pale cinnamon, 

 lined with black: northern Arizona, southern Utah and Colorado. 



A. I. vinnulus (Elliot). Color darker; under parts of body and tail 

 white: mountains of southern California. 



A. harrisi (Audubon & Bachman). Similar to A. I. leucurus; tail 

 iron gray above and below; length 230 mm.; tail 80 mm.; hind foot 40 

 mm.: southern Utah and Nevada into Arizona and northwestern New 

 Mexico. 



A . inter pres (Merr.) . Similar to A . leucurus, but darker; tail bushy, 

 with 2 free black bands; length 226 mm.; tail 80 mm.; hind foot 37 mm.: 

 western Texas and eastern New Mexico. 



A. nelsoni (Merr.). Color yellowish brown; under parts white; 

 length 228 mm.; tail 68 mm.; hind foot 40 mm.: San Joaquin Valley, 

 California. 



6. Citellus Oken. {Spermophilus Cuvier). Ground squirrels; 

 gophers. Small body and slender; cheek-pouches large; thumb rudi- 

 mentary (Fig. 182) ; dentition i /i, 0/0, 2 /i, 3 /3 : about 80 species, mostly 

 in the more or less arid regions of western America, northern Asia and 

 Europe ; about 1 5 species in the United States. Ground squirrels feed on 

 grains, seeds, fruits, plants, etc. and are very destructive to crops; they 

 also often eat insects and other small animals. They breed in deep bur- 



