BIRDS OF NORTH AND MIDDLE AMERICA. 681 
toe largest; anterior toes fully webbed, the anterior margin of web 
not at all incised. 
Plumage and coloration.—Plumage in general full and blended, the 
feathers of neck, however, hair-like, though full and dense, and those 
of occiput and nape somewhat elongated. Coloration extremely 
variable, sometimes entirely dusky, but usually dusky above and 
with more or less white on under parts, the postero-lateral portions 
of neck yellowish. 
Range.—Circumpolar regions, southward in winter as far as Peru, 
Africa, Australia, etc. (Monotypic.) 
COPROTHERES POMARINUS (Temminck). 
POMARINE JAEGER. 
Adults, light-colored phase (sexes alike).—Pileum, lores, and malar 
region, together with upper parts, except nape and hindneck, plain 
dark sooty gray; anal region and under tail-coverts lighter brownish 
gray, sometimes intermixed with whitish; rest of head and neck, 
including hindneck, together with under parts of body, immaculate 
white, the auricular region and sides of nape more or less strongly 
tinged with straw yellow; bill dull brownish (whitish in life), its 
terminal third (approximately) black; iris dark brown; legs and 
feet blackish, the upper portion of tarsus pale bluish (in life). 
Adults, intermediate phase (sexes alike).—Similar to the light- 
colored phase but chest and hindneck barred or transversely spotted 
with dusky, and lateral under parts irregularly barred with the 
same.® 
Adults, dusky phase (sexes alike).—Entirely plain dark sooty gray- 
ish brown, with a slaty cast in certain lights, the auricular region 
sometimes (usually?) tinged with yellowish. 
Young, light-colored phase-—Head, neck, and under parts dull 
buff, everywhere barred with dusky, the bars broad and sharply 
defined on under tail-coverts and flanks, indistinct on head and neck; 
upper parts dusky grayish brown, the scapulars and interscapulars: 
tipped with buff, the rump and upper tail-coverts spotted with the 
same. 
Young, dusky phase-—Entirely sooty grayish brown, the breast, 
abdomen, and sides narrowly and rather indistinctly, the under and 
upper tail-coverts broadly and sharply barred with buff. 
Downy young.—Immaculate grayish brown (between benzo brown. 
and deep brownish drab) passing into paler (between benzo brown 
and drab) on chin and under parts of body; bill brownish, the legs. 
and feet much paler brownish. 
@ The majority of specimens are of this intermediate phase, the two extremes being 
comparatively rare. A large series shows every gradation between the two extremes, 
