42 



NOETH AMERICAN FAUNA. 



[No. 37. 



with warm buff, their bases chestnut-brown; underparts ochraceous- 

 buff or light ochraceous-buff, the bases of the hairs on belly chestnut- 

 brown; sides of nose, lips, and chin white, bordered on throat with 

 hazel. 



SJcull. — Similar to that of Jiaviventris, but decidedly smaller; nasals 

 shorter, ending but little back of posterior border of premaxillae. 



Measurements. — Adult male: ^ Total length, 495-660 (average 

 554); tail vertebrae, 149-178 (165); hind foot, 76-80 (78). SlcuU: 

 Adult male: ^ Condylo-basal length, 85.7-86.5 (86.1); palatal length, 

 47.9-48.8 (48.3); postpalatal length, 34-34.8 (34.4); length of nasals, 

 36.6-37.6 (37.1); zygomatic breadth, 55.6-56.7 (56.1); breadth across 

 mastoids, 39.1-42.2 (40.6); least interorbital breadth, 17.8-19.5 

 (18.6); breadth of rostrum, 19.4-20 (19.7); maxillary tooth row, 

 19-19.3. Adult female: 3 Condylo-basal length, 76.4-79.4 (77.9); 

 palatal length, 42.6-44.6 (43.6); postpalatal length, 30.3-31 (30.7); 

 length of nasals, 31.5-33.5 (32.8); zygomatic breadth, 52.4-52.7 

 (52.5); breadth across mastoids, 37.6-38.6 (38); least interorbital 

 breadth, 17.1-18 (17.6); breadth of rostrum, 16.8-18.3 (17.3); max- 

 illary tooth row, 17.8-19.1 (18.5). 



RemarJcs. — This is a small, pale race of Jiaviventris living in the low 

 foothills of eastern Oregon and Washington and southern British 

 Columbia. It intergrades with Jiaviventris along the eastern base of 

 the Cascades, in Oregon; with nosopTiora in northwestern Montana; 

 and probably with parvula in northern Nevada. Specimens from 

 Spokane Bridge, Wash., are a little darker than the typical form, 

 and one from Elgin^ Oreg., has a slightly larger skull. Specimens 

 from Rockland, Wash., are intermediate between avara and Jiavi- 

 ventris. Melanistic individuals are rare in this race; one from Pull- 

 man, Wash., has the fore back solid black, faintly grizzled with 

 white, and the underfur pale gray; the hinder back is gray, the hairs 

 being black subterminally and tipped with white; the belly and feet 

 are black varied with buff; and the tail is black varied with tawny and 

 white. 



Specimens examined. — Total number, 53, as follows: 



British Columbia: Ashcroft, 8; Cascade, 6;^ Midway, 9;*'^'^ Nicola Valley, 1;« 

 Okanogan, 9; Penticton, 1;^ Vernon, 1. 



Oregon: Elgin, 2; Harney, 2; Guano Creek, Lake County, 1. 



Washington: Cheney, 1; Diamond, 1; Douglas, 1; Pullman (14 miles south- 

 west), 1; Rockland, 4; Spokane Bridge, 5. 



1 Four specimens from Okanogan, British Columbia; and Douglas, Wash. 



2 Two specimens from Okanogan and Cascade, British Columbia. 



3 Four specimens from southern British Columbia. 

 * Collection Victoria Mem. Mus. 



5 Collection Field Mus. Nat. Hist. 



6 Collection Amer. Mus, Nat. Hist. 



