MAMMALS OF THE MEXICAiST BOUNDARY. 493 



STablainily ^'IICROTIJST^. 



LEMMINGS and VOLES. 



Cranium abruptly and strongly constricted immediately in front of 

 the brain case, which is quadranj^idar, projectini^ scjuarely into the 

 orbit; orbital and temporal fossae well differentiated; jugal formino; 

 half, or more than half, of outer side of zygoma and always reaching 

 forward more than halfway from squamosal root to maxillary plate; 

 sagittal area subquadrate, usually broader than long; angular process 

 of mandible narrow, everted, hamular, and thickened at end; infra- 

 cond^dar notch low and deep. (Merriam.) 



and smaller than N. intermedia gilva. Color very much paler than in either; tail well haired, 

 very light in color and scarcely darker above than below. Skull differing from that of A'. 

 intermedia gilva in being smaller with shorter, heavier rostrum and wider nasals; audital 

 bullae larger, interparietal narrower. From N. lepida it differs in having rather narrower 

 brain case, heavier rostrum, shorter nasals, with maxillary arms extending farther back- 

 ward behind them; audital bullae larger. 



Color. — Upper parts pale buff yellow, somewhat lined along back with brownish, black- 

 tipped hairs; a white patch at base of ear; cheeks, sides, and upper surfaces of legs and arms 

 pale orange buff; head pale grayish buff j^ellow; whiskers mixed black and white; under 

 parts pure white — no pectoral collar — the hairs white to the base, except along lower sides 

 and on under surface of legs where they are pale gray at base; white of under parts extend- 

 ing very high up on sides; tail well haired, white below, j-ellowish white above, slightly 

 darker, more grayish toward tip above; feet and hands white; ears large, nearly naked, pale 

 grayish (probably nearly flesh color in life). 



Measurements. — Type, male, old adult; total length, 317: tail vertebrae, 155; hind foot 

 (from dried skin), 31.5 mm. 



Skull, type: Basal length, 37.2; occipitonasal length, 41.4; zygomatic width, 22.2; 

 mastoid width; 16.6; interorbital width, 6; length of nasals, 16.2; length of upper tooth 

 row, alveoli, 8; length of single half of mandible, 26 mm. 



Remarks. — Neotoma hella probably occurs with A', intermedia gilva. Mv. Thurber took 

 the latter at Whitewater, only a few miles from Palm Springs and in the same desert country. 



Mr. G. S. Miller, jr., has most kindly compared mj- type with the type of N. vennsta True, 

 and writes, me that it is not that animal, which is close to if not identical with iV. intermedia 

 gilva. N. hella can be told at once from A^. intermedia gilva by its smaller size and paler and 

 quite different coloration. Its relationship to A", lepida is closer, but it is very different in 

 color — much paler and less heavily marked above with dusky tipped hairs; the head in par- 

 ticular is much lighter and the color of the under parts is different. The tail of N. hella is 

 peculiar in being pale yellowish white above, not dusky as in N. lepida. (Proc. New 

 England Zool. Club, I, 1899, p. 66). 



NEOTOMA STEPHENSI Goldman. 

 STEPHENS WOOD-RAT. 



Neotoma stepTiensi Goldman, Proc. Biol. Soc. Washington, XVIII, p. 32, Feb. 2, 1905 

 (original description). 

 The following is Mr. Goldman's description: 



Type from Hualpai Mountains, Arizona (altitude, 6,300 feet). Adult female, No. 

 117466, U. S. National Museum Biological Survey Collection. July 1, 1902. 

 F. Stephens. Original number 4192. 

 General characters. — Size small; fur long, soft, and silky; tail slightly bushy, nearly con- 



