THOMOMYS. 220 



345. alpinus. {'J'/iomomys), Merr., Proc. Biol. Soc. Wash., 1897, 



p. 216. 



Type locality. Mt. Whitney, California. 



Geogr. Distr. High Sierra, eastern California. 



Genl. Char. Size small; dark; similar to T. fiilrus, but paler; 

 skull small; zygomata spreading; nasal short; brain case rounded; 

 temporal ridges not strongly pronounced. 



Color. Above drab brown suffused with pale fulvous brown; 

 nose and mouth dusky; beneath plumbeous washed with ochraceous 

 buff; feet and tail whitish. 



Measurements. Total length, 228; tail vertebra, 67; hind foot, 30. 



346. clusius. {Thomomys), Coues, Proc. Acad. Nat. Scien. Phil., 



1875, p. 138. 



Type locality. Bridger's Pass, Rocky Mountains. 



Geogr. Distr. Uncompahgre Reservation, Utah, through south- 

 western Wyoming into southern and central Idaho. 



Genl. Char. Smallest species known; tail less than one-third 

 the length of head and body; colors pale, mammae six pairs; claws 

 weak. 



Color. Above pale yellowish gray tinged with pale brown; fur 

 plumbeous at base; beneath white to the roots. Feet and tail white, 

 snout blackish. 



Measurements. Total length, 127; tail vertebra;, 38; hind foot, 18. 



347. aureus. {Thomomys), Allen, Bull. Amer. Mas. Nat. Hist., 1893, 



p. 49, pi. I, figs. 6, 7. 



Type locality. Bluff City, Utah. 



Geogr. Distr. San Juan region, southeastern Utah. 



Genl. Char. Size large; claws developed, large; skull similar to 

 that of T. perpallidus, but broader and heavier. 



Color. Post Breeding Pelage. Above golden, interspersed with 

 dusky tipped hairs on back and crown; beneath white to roots of 

 hairs; around ear blackish; feet white. Tail, basal half yellowish, 

 apical half whitish. 



Breeding Pelage. Above dull dusky yellowish; beneath grayish 

 white, base of hairs plumbeous. 



Measurements. Total length, 296; tail vertebrae, 66; hind foot, 35. 



348. perpallidus. {Thomomys), Merr., Scien., 1886, viii, p. 588. 

 7\pi- locality. Colorado Desert, southern California. 



Geogr. Distr. Colorado Desert, southern California and north- 

 eastward to the Painted Desert, Arizona. 



Genl. Char. Similar to T. clusius, tail longer, half the length of 

 head and body. Color pale. 



