586 SYSTEMA TIC SYNOPSIS. — GALLING — ALE CTOBOP ODES. 
568. L. al'bus. (Lat. alhuSj white. Figs. 403, 404.) Willow Grouse. Willow Ptarmigan. 
Bill very stout and convex, its depth at base as much as the distance from nasal fossa to tip ; 
whole culmen 0.75 ; bill black at all seasons. $ ^ , 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, I nat. size. (From Brelim.) 
and fore parts rich chestnut or orange-brown, more tawny-brown on back and rump; the richer 
brown parts sparsely, the ta\my-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; Mdng about S.OO; tail 5.50. Arctic and Northern N. Am. from ocean to ocean, 
into the northernmost 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- 
