BIRDS OF NORTH AND MIDDLE AMERICA 



91 



to nearly truncate, the rectrices (16) not wider distally than tips, more 

 or less rounded. Tarsus slightly less than one-sixth to a little more than 

 one-fifth as long as wing, completely and densely clothed with long, hair- 

 like feathers, in winter plumage, with much shorter feathers, the planta 

 tarsi nude, in summer; middle toe decidedly shorter than tarsus, com- 

 pletely feathered (the feathering even sometimes concealing claws) in 

 winter, in summer nude except basally, their upper surface without 

 distinct transverse scutella except on terminal phalanx, being elsewhere 

 covered with small, rounded, rather indistinct scales ; claws relatively 

 broad, very concave beneath, long in winter, much shorter in summer. 



Figure 8. — Lagopus lagopus. 



Plumage and coloration. — A more or less extensive nude superciliary 

 space, brightly colored (red) and fringed in summer; neck with neither 

 air sacs nor elongated feathers; plumage in general rather soft (except 

 remiges and rectrices), the feathers relatively broad, rounded, and dis- 

 tinctly outlined, except on lower abdomen, anal region, and legs, where 

 soft, hairlike, and blended. In winter plumage entirely white except tail 

 (in part) and, sometimes, a black stripe on side of head — the tail also 

 entirely white in one species.^* In summer the plumage, more or less 

 extensively mottled or barred or spotted with black, brown, dusky, gray, 

 or ochraceous ; the remiges, however, always remaining white (except 

 in L. scoticus). 



" In L. scoticus the plumage is entirely blackish and brown or rarely mottled, 

 even in winter, even the primaries being wholly dusky. 



