1915.] 



MAEMOTA FLAVIVENTEIS GEOUP. 



47 



Clmracters. — About the size of engelhardti, but with longer tail; 

 colors much more ochraceous above and redder below, the fore part 

 of back overlaid with a mantle of golden buff. Compared with 

 dacota: Slightly smaller, with upperparts less extensively reddish 

 and more mixed with black, and underfur decidedly paler; skull 

 averaging smaller, with relatively slenderer rostrum and much smaller 

 palatal foramina. 



Color. — Underfiu" of upperparts at base blackish brown on fore 

 part of body, becoming fuscous on hinder parts, succeeded by a 

 broad area of whitish buff (tilleul buff of Kidgway) shading (on 

 hinder back) to pinkish cinnamon or pale russet; long hairs black 

 sub terminally, broadly tipped on fore part of back with warm- or 

 ochraceous-buff and on hinder part with white or buffy white; top 

 and sides of head blackish brown, with a conspicuous band of white 

 or buffy white across face in front of eyes; sides of face mixed with 

 cinnamon or white; sides of nose, lips, and chin white or buffy white; 

 sides of neck with ochraceous-buff patches behind ears; fore legs 

 kaiser brown; hind legs and rump warm buff; hind feet hazel to 

 russet; tail chestnut-brown or blackish brown, varied with hazel or 

 cinnamon-buff (fading to dull cinnamon or clay color) ; underparts 

 hazel shaded with kaiser brown, becoming bright chestnut on throat 

 and sometimes on beUy. Variation: A dark, brownish color-phase 

 occurring rai*ely, and seemingly most frequent at high altitudes, may 

 be described as follows: General tone of upperparts dark brown 

 grizzled with white; underfur at base mouse gray (shading on hinder 

 back to fuscous) succeeded by buffy white (shading on hinder back 

 to light pinkish cinnamon); long hairs blackish brown, tipped with 

 white; top and sides of head blackish brown; xmderparts mixed 

 blackish brown and pinkish buff in about equal proportions; throat 

 shaded with russet; feet and tail blackish brown; legs brownish 

 mixed with ochraceous-tawny. (Specimen from Lake Fork, Wind 

 River Moimtains, Wyo.; altitude 10,600 feet.) 



Slcull. — Females averaging larger than those of engelhardti, with 

 broader rostrum and interorbital region and smaller buUae. Com- 

 pared with dacota: Smaller, with narrower rostrum and interorbital 

 region, and much smaller palatal foramina. 



Measurements. — Adult male: ^ Total length, 590-600 (average 

 595) ; tail vertebrae 159-170 (165) ; hind foot, 78-79 (78.5). Old male 

 from Pryor Mountains, Mont.: 670; 165; 96. Adult female:^ 534- 

 591 (565); 145-175 (165); 75-85 (78). Slcull: Adult male:^ Condylo- 

 basal length, 86.7-94.2 (90.6); palatal length, 47.7-53 (50.7); post- 

 palatal length, 34.2-37.2 (36.2); length of nasals, 35.1-40.4 (37.8); 

 zygomatic breadth, 55.7-63.7 (59); breadth across mastoids, 41.3-45 



1 Two specimens from Bitterroot Valley, Mont. 



* Seven specimens from Bitterroot Valley, Mont. 



3 Six specimens fi-om Montana, Idaho, and Wyoming. 



