i8o 



Osgood, Nevj North American Birds. 



r Auk 

 LApril 



Lagopus leucurus altipetens,^ subsp. nov. 

 White-tailed Ptarmigan. 



Southern 



Type from Mt. Blaine, Colorado. No. 69774 U. S. National Museum, ? 

 ad. Collected Sept. 3, 1874, by C. E. Aiken. 



Characters. — Adult in fall plumage similar to Lagopus leucurus, but 

 general color of upperparts bufl: instead of gra\ ; adult in summer plumage 

 indistinguishable in color from leucurus; wings and tail decidedly longer 

 than in leucurus. 



Color. — Adult male in fall plumage : Upper parts pale cinnamon rufous, 

 back, rump and upper tail-coverts finely dotted and vermiculated with 

 brownish black; head and neck all around somewhat lighter with broader 

 vermiculation and spotting; breast, sides and flanks similar to back but 

 daiker; occasional feathers of breast with broad bars or median areas of 

 white; middle of abdomen, under tail-coverts, tail and wings pure white. 



Measurements. — The southern bird is considerably the larger as will be 

 seen by the following table. Measurements are in millimeters. 



Remarks. — Until the present year the northern White-tailed 

 Ptarmigan has been represented in the National Museum collec- 

 tion only by specimens in summer plumage or in white winter 

 plumage. During the past season, however, I secured an adult 

 female in fall plumage in the mountains on the south side of 

 Turnagain Arm, Cook Inlet, Alaska. Before skinning this bird, 

 it was evident to me that it was different from any ptarmigan that 

 I had ever seen before. Consequently it was one of the first birds 



' Altipetens = seeking the heights. 



• These are the measurements of Swainson's type expressed in millimeters. 



