1915.] 



MAEMOTA FLAYIVENTRIS GROUP. 



41 



and, except for size and cranial characters, is the only sure distin- 

 guishing characteristic of the two forms. It seems clear, therefore, 

 that the name fiaviventris must be appHed to the darker of the two 

 forms found in Oregon and Washington, and I have therefore selected 

 Mount Hood, Oreg., as the type locahty. The series available from 

 the Cascades is small and contains only one adult male skull — an old 

 weathered specimen picked up on Mount Hood. Several adult fe- 

 males in the collection from Crater Lake and the Klamath Lake 

 region, however, agree essentially with specimens from Fort Crook 

 and the northern Sierra of Cahfornia. South of Lake Tahoe fiavi- 

 ventris grades imperceptibly into the subspecies sierrae, occupying 

 the southern end of the Sierra Nevada, in the Mount Whitney region. 

 Intergradation with avara occurs in the region east of Klamath Lake 

 and probably aU along the east base of the Cascades. 

 Specimens examined. — Total number, 48, as follows: 



California: Donner, 17; Emerald Bay, 1; Fort Crook, 3; Glen Alpine Springs, 

 El Dorado County, 2;^ Hope Valley, Alpine County, 2; Lassen Creek, Warner 

 Mountains, 1; Mount Lassen, 2; Pine Creek, Lassen County, 1. 

 Nevada: Mount Siegel, Douglas County, 1;^ Winters Mine, Douglas County, 1.^ 

 Oregon: Crater Lake, 2; Fort Klamath, 3; Klamath Lake, 6; Linkville, 2; Mount 

 Hood, 3; Summer Lake, 1. 



MARMOTA FLAYIVENTRIS AVARA (Bangs\ 



Pallid Yellow-Bellied ^Marmot. 



(PI. VII, fig. 3; PI. XIII, fig. 3.) 



Arctomys jlaviv enter avarus Bangs, Proc. New England Zool. Club, I, 1899, p. 68. 

 [Marmota Jlaviventer] avarus Trouessart, Cat. Mamm., SuppL, 1904, p. 344. 



Type locality. — Okanogan, British Columbia. 



Distrihution. — Interior valleys and foothills of southern British Co- 

 lumbia and eastern Washington and Oregon. 



Characters. — Similar to fiaviventris, but smaller and colors paler, 

 especially the underfur and fore legs; upperparts more extensively 

 overlaid with buff. 



Color. — General tone of upperparts chestnut-brown, heavily griz- 

 zled with buff ; underfur at base deep mouse gray (varying to pale 

 fuscous) succeeded by buffy white, the latter shading to hght pinkish 

 cinnamon on hinder back; long hairs blackish broTO or clove brown 

 sub terminally, extensively tipped on fore back with warm buff and 

 on hinder back with hght buff; head and face blackish brown or dark 

 chestnut-brown, with an indistinct narrow band of white or buff' 

 across face in front of eyes; sides of neck warm buff; fore legs and 

 feet ochraceous-buff; hind legs, hind feet, and buttocks hght ochra- 

 ceous-buff, the feet varying to hazel; tail hazel, the hairs tipped 



1 Collection Mus. Vert. Zool., Univ. of California. 



2 Collection Field Mus. Nat. Hist. 



