LARIDA, JAEGERS.—GEN. 279-80. 309 
Skua Gull. Length about 2 feet; wing 17 inches; tail 6; tarsus 23, 
middle toe and claw 3; bill about 2, its depth at base 8. Above, blackish- 
brown, varied with chestnut and whitish ; throat and sides of neck yellowish- 
brown, streaked with white ; below, fusco-rufous, with an ashy ‘shade ; quills 
blackish, with white shafts and a conspicuous large white area at base; tail 
feathers blackish, white at the base; very old birds are much darker and 
more uniform brown, almost blackish above, rather smoky brown below. 
Northern N. Am., rare or casual; “California.” Lestris cataractes Nurv., 
ii, 812; Stercorarius cataractes Lawr., Ann. Lye. N. Y. 1853, 71, and in 
Bo., 838; Buphagus skua Cours, Proe. Phila. Acad. 1863, 125. . sxua. 
** Bill and tarsi relatively longer than in the foregoing ; central rectrices finally 
projecting far beyond the rest. Smaller and less robust. (Stercorarius.) 
Pomarine Jaéger. Middle tail feathers finally projecting about 4 inches, 
broad to the tip. Length about 20 inches; wing 14; bill 14-12; tarsus 
about 2. Adult: back, wings, tail, crissum and lower belly blackish-brown, 
deepening on the top of the head and slight occipital crest to brownish- 
black ; below, from bill to belly, and neck all round, pure white, excepting 
acuminate feathers of sides of neck, which are pale yellow; quills whitish 
basally, their shafts largely white ; tarsi above blue, below, with the toes and 
webs, black. Wot quite adult: as before, but breast with dark spots, sides 
of the body with dark bars, blackish of lower belly interrupted ; feet black. 
Younger: whole under parts, with upper wing and tail coverts, variously 
marked with white and dark; feet blotched with yellow. Young: whole 
plumage transversely barred with dark brown and rufous; feet mostly 
yellow. Dusky stage (coming next after the barred plumage just given?) ; 
fuliginous, unicolor; blackish-brown all over, quite black on the head, 
rather sooty brown on the belly; sides of the neck slightly gilded. 
Northern N. Am., ranging S. to the Middle States in winter. Sw. and 
Riew., F. B.-A. ii, 429; Nurv., ii, 315; Aup., vii, 186, pl. 451; Lawr. 
PHB GUROO Orme OOUNS@iacr 129. © .. 6 s.c0 « % ss POMATORHINUS: 
Parasitic, or Richardson’s Jaéger. Middle tail feathers finally projecting 
about 4 inches, ¢apering, acuminate; smaller; wing 12-13; tarsus 197-1]; 
bill 14-13; tail 5-6, the long feathers up to 9 inches. Adult: upper parts, 
including top of the head and slight occipital crest, and crissum, blackish- 
brown, deeper on wings and tail; chin, throat, sides of head, neck all round 
and under parts to the vent, white, the sides of the neck pale yellow; quills 
and tail feathers with whitish shafts ; feet blue and black. Younger: clouded 
below with dusky in variable pattern and amount. Young: barred cross- 
wise with rufous and dusky; feet mostly yellow. There is a fuliginous 
stage, precisely:as in the last species. Northern N. Am.; U.S. in winter. 
Lestris richardsonii Sw., F. B.-A. ii, 433, pl. 73 (in dusky plumage) ; 
Nurr., ii, 319 (dusky) ; Aup., vii, 190, pl. 452; Stercorarius richardsonii 
Cougs, 1. c. 135; Lestris cepphus Nurtr., ii, 818 (adult); Stercorarius 
parasiticus Lawr. in Bp., 839; Cours, /.c. 1382. . . . . PARASITICUS. 
- Arctic, Long-tailed, or Buffon’s Jaéger. Middle tail feathers finally pro- 
