628 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



(iti"-life); iris grayish brown ; legs and feet yellowish green or olive- 

 yellowish. 



Adults in winter. — Similar to summer adults, but occiput, nape, and 

 hindneck longitudinally spotted with grayish brown; "iris cream 

 color with dark gray motthngs;"" rictus orange-red ;<^ naked orbital 

 ring dusky red;*^ legs and feet grayish olive-yellow, the joints darker, 

 the webs purer yellow." 



Young. — Head and neck dull whitish, striped with grayish brown ; 

 upper parts grayish brown, the feathers irregular but broadly mar- 

 gined with duU whitish, grayish white, or pale dull buffy; greater 

 wing-coverts and secondaries pale gray, margined with pale buff and 

 with a sub-margin of dusky grayish brown; tertials grayish brown 

 margined with buffy white; primary coverts and primaries dull black 

 or dusky, very narrowly tipped with white; rump and upper tail- 

 coverts white, irregularly spotted with dusky grayish brown: tail with 

 proximal two-thirds (approximately) grayish white, fading into 

 pure white basally, the distal third dusky grayish brown narrowly 

 tipped with white, the grayish white of lateral rectrices finely mottled 

 with dusky, especially toward base; under parts grayish white, the 

 chest and sides thickly spotted or blotched with light grayish brown; 

 bill blackish terminally, dull whitish or flesh color basally; iris dark 

 brown ; naked orbital ring brownish ; legs and feet whitish or yellowish 

 flesh color. 



Downy young. — ''Covered all over with a soft yellowish gray 

 down, whiter in tint on the face, throat, and abdomen; forehead 

 blackish brown; entire upper parts spotted here and there with 

 large blackish spots, one or two spots being also on the throat, under 

 parts generally unspotted, except that on the flanks there are some 

 irregular black marks. It may be distinguished from the young 

 of other GuUs by a large black spot which touches the base of the 

 upper mandible, and which is never absent, though often varying 

 in size."^ 



Adult male.-^Wmg, 348-380 (364); tail, 135-150.5 (141.9); exposed 

 culmen, 36.5-45 (39.5); tarsus, 45-56 (50.2); middle toe, 35-45 

 (38.3).^ 



Adult female. — Wing, 339; tail, 139; exposed culmen, 38; tarsus, 

 52; middle toe, 42.5.'' 



a Stejneger, Bull. U. S. Nat. Mus., No. 29, p. 76. 



^ Dresser, Birds of Europe. 



c Eight specimens. 



d One specimen (from Bering Island, Kamchatka). 



