54 



NORTH AMERICAN FAUNA. 



[No. 37. 



underparts mixed dark chestnut-brown or blackish brown and pale 

 buff (tdleul buff of Ridgway) in varying proportions, buff usually 

 roost pronounced in the median line; chin, and sometimes throat, 

 shaded with tawny or bay. Young (Osier, Colo.): General tone 

 above, clove brown (becoming slightly more tawny on hinder back) 

 sparingly grizzled with white; underparts mixed blackish brown and 

 light buff; tail snuff brown above, pale clove brown below; hind feet 

 same color as under side of tail, overlaid with light buff. 



SlcuU. — Similar to that of dacota, males about the same size or 

 slightly smaller, females larger; nasals (in females) averaging longer; 

 palatal foramina narrower; interpterygoid fossa broader; postorbital 

 constriction narrow; similar to that of warreni but averaging shorter 

 and relatively broader with slightly broader premaxillae. 



Measurements. — Adult male :^ Total length, 645-664 (average 655); 

 tail vertebrae, 180-220 (204) ; hmd foot, 90-92 (90.7). Adult female 

 630-670 (646); 180-220 (190); 88-90 (89.3). SlcuU: Adult male: ^ 

 Condylo-basal length, 88.3-90.8 (89.5); palatal length, 49.4-52.7 (51); 

 postpalatal length, 34-35.2 (34.6); length of nasals, 36.4-38.4 (37.4); 

 zygomatic breadth, 60.2-60.4 (60.3); breadth across mastoids, 41.5- 

 41.7 (41.6); least interorbital breadth, 21-21.1; breadth of rostrum, 

 21.9-23.3 (22.6); maxillary tooth row, 19-19.8 (19.4). Adult female : ^ 

 Condylo-basal length, 84.5-89.5 (87.7); palatal length, 48.4-50.3 

 (49.3); postpalatal length, 31.9-35.7 (34.2); length of nasals, 35.4-39 

 (37.5); zygomatic breadth, 59.4-60.6 (59.8); breadth across mas- 

 toids, 41-43.8 (42.7); least uiterorbital breadth, 20.4-22.3 (21.1); 

 breadth of rostrum, 22.3-22.4; maxiUary tooth row, 20-21. 



Remarks. — This is the darkest and one of the largest of the races 

 oi fiaviventris. In its dark colors and the absence of light face mark- 

 ings it somewhat resembles the monax group. It is closely related to 

 warreni and probably intergrades with it, but material from southern 

 Colorado is too scanty to show clearly its relationships. A badly worn 

 skin without skull from ^^Fort Massachusetts" [ = mountains near] 

 has been in the National Museum collection for many years, but not 

 until 1903 and 1904, when Vernon Bailey collected a fine series of 

 adults in the Pecos River and Taos Mountains, N. Mex., was it possi- 

 ble to determine the characters of the species. 



In a series of 12 specimens from Osier, Colo., in the San Juan 

 Range, about half of the individuals are considerably paler above 

 than in the typical form, being uniformly pinkish cinnamon grizzled 

 with white, without prominent brownish markings. A badly worn 

 specimen from Florida, Colo., is decidedly redder above, particularly 

 on the head and feet, indicating apparent intergradation with 



1 Four specimens from. New Mexico. 



2 Two specimens from Wheeler Peak, N. Mex. 



s Three specimens from Wheeler Peak and Pecos Baldy, N. Mex. 



