FIELD BOOK OF MAMMALS 



San Joaquin Valley and neighboring foothills and valleys, 

 California. North to Little Panoche Creek, San Benito 

 County; south to Carriso Plain and Bakersfield." (Hol- 

 lister) 

 Ramona Grasshopper Mouse. — Onychomys torridus ramona 

 (Rhoads). 

 Darkest of the torridus group found in the United States. 

 Upperparts from blackish brown (winter) to reddish brown 

 (summer) ; sides reddish brown ; ear tufts inconspicuous, 

 brown and whitish; tail above, blackish brown, tip and 

 underside whitish; underparts creamy white. Total length, 

 5.6 inches; tail vertebras, 2.0 inches; hind foot, .8 inch. 

 Found in "Extreme southwestern California and north- 

 western Lower California, Mexico. From San Fernando 

 and San Bernardino south into Tecate Valley." (HolHster) 



******* 

 The Grasshopper Mice are soft -furred, attractive rodents 

 and little apt to be confused with any other Mice. The white 

 underparts serve to distinguish them from House Mice and 

 most of the Voles, and the proportionally short, thick tail sets 

 them off from the White-footed Mice. 



Grasshopper Mice dwell on the plains and open stretches 

 and are not found in forests. They have a preference for dry 

 regions and reach their greatest abundance in the arid sections 

 of the West or the deserts of the Southwest. These Mice live 

 in burrows in the ground and in sandy districts one has little 

 difficulty in finding their tracks and entrances to subterranean 

 workings. As a rule they are more or less closely associated 

 with other plains-loving Mice such as Peromysciis and Perog- 

 nathus, and a trap set on one of the sandy runaways may take 

 all three genera on successive nights. The Scorpion Mice are 

 strictly nocturnal. 



There are about four young in a litter and in the southern 

 part of their range these Mice have more than one litter a year. 

 On the northern part of their range, where the summer season 

 is shorter, but one family is raised in a season. Although 

 Grasshopper Mice may be inactive during periods of severe 

 weather, they do not hibernate. 



Genus Reithrodontomys ' 



Dentition: Incisors, {; Canines, {] ; Premolars, §; Molars, f = 16. 



I See A. H. Howell, North American Fauna, No. 36, 1914, for a full 

 revision of this genus. 



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