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 white terminal spot; bill pale yellow, more or less 
tinged with greenish; rictus and inside of mouth orange-red or 
vermilion (in life); iris dark brown; naked eye-ring orange-red or 
vermilion (in life); 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 
extending 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 with outer webs black, tail crossed 
at tip (except on outermost rectrices) by a broad band of black 
(widest on middle rectrices), bill black, and legs and feet dusky 
brownish. 
Downy young.—Head, neck, wings, and under parts immaculate 
white, the neck and base of wings 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 (88.7); 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 (84.1); tarsus, 31-32 (31.5); middle toe, 37-39 
(88.1).° 
« Four specimens. b Five specimens. 
Ex- lan 
Locality. Wing. | Tail. | posed | Tarsus. anus 
‘culmen - 
MALES, 
One adult male from Spitzbergen..............-. sateen eye 323 180 39 34 41 
One adult male from Norway.-..........0200.0eeeeceeeeeneeees 298 128.5] 39 33 89.5 
One adult male from Davis Strait................2.. 22 e eee eee 306 126 39 35 41 
One adult male from Maine (December)...................-.+- 324 129 38 34.5 43 
Eleven adult males of R. t. pollicaris.........2.02..000 ce eee eee 323.6) 135.1 40 33.9 40.9 
Ten adult males of R. brevirostris.............022. 0c eee eee ee eee 311.6 | 125.4 29.4) 30.1 39. 3 
FEMALES. 
Two adult females from France..........-...-2002c0cee seen enue 301.5 | 123 34.2} 31.2 37.7 
One adult female from Orkmeys.............2022.222eeceeee eens 293 114.5 |... 20. 32 39 
One adult female from Cumberland Gull..................25205 298 126 34 32 39 
One adult female from New Hampshire (January)............ 303 119.5] 34 St 37 
Five adult females of R. t. pollicaris............0 000 cee ee ee ee ee 320.6} 1381.3 39.1 33.7 40 
Nine adult females of R. brevirostris............2.202 cece eee ees 312.91 125.7] 20.71 28 39, 3 
