586 



SYSTEMATIC SYNOPSIS — GALLING — ALE CTOROPODES 



568. L. al'bus. (Lat. alhus, white. Figs. 403, 404.) Willow Grouse. Willow Ptarmigan. 

 Bill very stout and convex, its dei)th at base as much as the distance from nasal fossa to tip; 

 whole culmen 0.75 ; bill black at all seasons. ^ 9, in winter: Snow white; 14 tail-feathers' 

 black, white-tipped ; the middle pair (which most resemble and perhaps are true rectrices, hav- 

 ing no after-shafts) together with all the coverts, one pair of which reach to end of tail, white ; 

 shafts of several outer wing-quills black; no black stripe on head. $, in summer: The head 



Fig. 403. — Willow Ptarmigan, summer plumage, J nat. size. (From Brehm.) 



and fore parts rich chestnut or orange-brown, more tawny-brown on back and rump; the richer 

 brown parts sparsely, the tawny-brown more closely, barred with black ; most of the wings and 

 under parts remaining white. 9 similar, wholly colored excepting the wings, the color more 

 tawny than in the ^, and more heavily, closely, and uniformly barred with black. Length 

 15.00-17.00; wing about 8.00; tail 5.50. Arctic and Northern N. Am. from ocean to ocean, 

 into the northeramost U. S. Eggs very heavily colored, with bold confluent blotches of intense 

 burnt sienna color, upon a more or less reddish-tinted buff ground. All the eggs of birds of this 

 family are colorless when the shell first forms high in the oviduct, acquiring pigment as they 

 pass down; in the ptarmigan, where the coloring is so heavy, an egg cut from the pigment- 



