104 CYNOMYS. ARCTOMYS. 



under parts pale fulvous; tail like back on basal half, rest mixed black 

 and white bordered and tipped with white. 



Winter Pelage. Above pale buff, mixed with black; under parts 

 pale yellow to fulvous. 



Measurements. Average total length, 360; tail vertebrae, 69; hind 

 foot, 60. 



133. lewisil. {Arctomys), Aud. & Bach., Quad. N. .\m.. Ill, i«53, p. 



32, pi. cvii. 



leucurus, Merr., N. Am. Faun., No. 4, 1890, p. 33. 



Type locality. Wyoming. 



Geogr. Distr. Wyoming, Utah in llncompahgre Indian Reser- 

 vation. 



Genl. Char. Similar to C'. gunnisoni, but two-thirds of tail white. 



Color. Above grizzled; grayish buff mixed with black on rump; 

 black patch over eye and a black and buff one below the eye; thighs 

 buff; under parts buffy white. Tail, basal half like back; terminal 

 half white. 



Measurements. Total length, 335; tail vertebrae, 53; hind foot, 58. 



134. arizonensis. Mearns, Bull. Am. Mus. Nat. Hist., i8go, p. 305. 

 Ty/ie locality. Point of Mountain, near Wilcox, southern Arizona. 

 Geogr. Distr. Southern Arizona. 



Genl. Char. Size large; tail nearly twice as long as E. giinni- 

 soni. 



Color. Summer Pelage. Above vinaceous-cinnanion; below whit- 

 ish; tail with a narrow subterminal bar of broccoli brown. 



Winter Pelage. Above pale sandy buff; below white tinged with 

 buff. 



Measurements. Average total length, 376; tail vertebras, 84; 

 hind foot, 61. 



40. Arctoniys. 



I. iz:!; p. ^JZl- M. ^^ - 22. 



Arctomys. Schreb. Saugeth., 1792, p. 770. Type.-/, marmotta, Linn. 



Mus. Linn. Syst. Nat., 1758, i, p. 601 (Part). 



Glis. Erxleb. Syst. Regn. Anim., 1777, p. 358 (Part). 



Form stout, heavy, legs short; tail short, stout, hairy; cheek 

 pouches small; fore feet with a rudimentary poUex having a flat nail. 

 Skull heavy; superior outline nearly straight to posterior portion of 

 nasals when it curves downward; interorbital region depressed; post- 

 orbital processes broad at base, stout, decurved, and at right angles 

 to axis of skull; zygomata expanded; molar series with two trans- 

 verse grooves across their crowns, nearly parallel, barely converging 



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