BIRDS OF NORTH AND MIDDLE AMERICA. 585 
wing-coverts, immaculate pure white; back, scapulars, and wings 
uniform pale gull gray, on the primaries passing gradually into white 
terminally, the secondaries passing into white terminally (for about 
44,5 mm.); shafts of primaries yellowish white to pale straw yellow; 
bill yellow demon, or gamboge), the mandible with a lateral sub- 
terminal spot of red; iris yellow; naked eye-ring red; legs and feet 
flesh color or pinkish (in life). 
Adults in winter —Similar to the summer plumage, but head and 
neck streaked or clouded with pale-grayish brown or brownish gray; 
naked eye-ring pale yellow and legs and feet paler flesh color. 
Young in first plumage.—General color grayish white, more or 
less tinged with pale brownish gray, or grayish brown, on under parts, 
the upper parts transversely mottled with brownish gray and more or 
less tinged with pale buffy, the head and neck streaked and clouded 
with pale brownish gray or grayish brown; tail pale brownish gray 
or grayish brown, more or less mottled with whitish; bill yellowish 
or flesh color with terminal portion blackish; iris yellowish brown; 
legs and feet brownish flesh color. 
Immature (second winter ?).—Entirely white or yellowish white, 
the bill and feet colored essentially as in first plumage. 
Downy young.—Grayish white, the under parts more purely white; 
head and neck irregularly marked with scattered large spots of dusky, 
the back, wings, and rump irregularly clouded with dark grayish. 
Adult male.—Wing, 428-474 (453.7); tail, 175-207 (186.3); ex- 
posed culmen, 53-67.3 (60.2); tarsus, 53.1-74 (65.6); middle toe, 
51.3-66 (61.3).¢ 
Adult female——Wing, 424-457 (436.7); tail, 172.5-190 (182.7); 
exposed culmen, 49-60.5 (55.4); tarsus, 57-69.3 (62.5); middle toe, 
53-63 (56.5).° 
a Eleven specimens. b Hight specimens. 
Ex- 
Locality Wing. | Tail. | posed | Tarsus.) Middle 
culmen toe. 
MALES. 
Three adult males from northeastern North America..,........ 455.6 | 195.5 61.5 61.5 59.8 
Four adult males from Point Barrow, Alaska.............----- 449.4 | 185.7 56. 6 65.8 61.6 
Four adult males from Bering Sea, etc., Alaska.............--- 456.8 | 197.7 63.8 68.5 62.3 
FEMALES. 
One adult female from Spitzbergen..............---2.---2+0+- 457 190 60.5 62 63 
Two adult females from Cumberland Gulf.............---.-.-- 431.5 | 180.7 58.2 65.4 | (58.5) 
Two adult females from Point Barrow, Alaska........-....---- 430.5 | 175.7 49.5 58.5 53.2 
Three adult females from St. Michaels and Point Gustavus, 
AlGSKA).... tcnic adi SHER EE eee ee asmes meee ees ee 437.8 | 186.3 55.8 63.5 55.9 
