566 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



outer web of which is almost wholly black) and 18-20 mm. on the 

 fifth; proximal primaries pale neutral gray, scarcely paler terminally, 

 the sixth (from outside) sometimes with a black subterminal spot on 

 outer web, the fifth (from outside) tipped with white, the fourth some- 

 times also with a v/hite terminal spot; bill pale yellow, more or less 

 tinged with greenish; rictus and inside of mouth orange-red or 

 vermihon (in life); iris dark brown; naked eye-ring orange-red or 

 vermihon (hi fife); legs and feet black or olivaceous-black. 



Winter plumage. — 'Similar to the summer plumage but occiput, 

 nape, and hindneck (sometimes sides of chest also) washed with light 

 or pale neutral gray, the auricular region and a spot immediately in 

 front of eye darker gray or blackish gray, this color sometimes 

 extendmg across occiput. 



Young. — ^Similar to the winter plumage but hindneck crossed by 

 a patch of black, anterior lesser wing-coverts with more or less of 

 black, proximal lesser coverts and tertials black centrally, primary 

 coverts and five outer primaries v/ith outer webs black, tail crossed 

 at tip (except on outermost rectrices) by a broad band of black 

 (widest on middle rectrices), biU black, and legs and feet dusky 

 brownish. 



Downy young. — Head, neck, wings, and under parts immaculate 

 white, the neck and base of wmgs more or less tinged with buff; 

 back, rump, and flanks yellowish gray, the down darker basally. 



Adult male.— Wing, 298-324 (312.7); tail, 126-130 (128.4); 

 culmen, 38-39 (38.7); tarsus, 33-35 (34.1); middle toe, 39.5-43 

 (41.1).« 



Adult female.—Wing, 293-306 (299.4); tail, 114.5-126 (121.2); 

 culmen, 34-34.5 (34.1); tarsus, 31-32 (31.5); middle toe, 37-39 

 (38.1).^ 



a Four specimens. 



b Five specimens. 



Localitj^ 



MALES. 



One adult male from Spitzbergon 



One adult male from Norway 



One adult male from Davis Strait 



One adult male from Maine (December) 



Eleven adult males oi R. t. pfAlicaris 



Ten adult males of R. hrevirostris 



FEMALES. 



Tvfo adult females from France 



One adult female from Orkneys. 



One adult female from Cumberland Gulf 



One adult female from New Hampshire (January) 



Five adult females of iJ. t. pollicaris 



Nine adult females of R. hrevirostris 



Wing. 



323 



298 

 •306 

 324 

 323. 6 

 311.6 



301. 5 



293 



298 



303 



320. G 



312.9 



Tail. 



130 



128.5 



126 



129 



1^5. 1 



125.4 



123 



114.5 



126 



119.5 



131.3 



125.7 



Middle 

 toe. 



41 



39.5 



41 



43 



40.9 



39.3 



37.7 



39 



39 



37 



40 



39. 3 



