General 
descrip- 
tion. 
Adult bird. 
522 NATATORES. CATARACTES. SKuUA, 
and mosses, and its two eggs are of a dark oil-green, with 
irregular blotches of liver-brown. At this season the bird is 
very courageous, and, like the Common Skua, attacks every 
intruder upon the limits of its territory, by pouncing and 
striking at the head with its bill and wings. It also occa- 
sionally endeavours to divert attention by feigning accidental 
lameness, in the same manner as the Partridge and Lapwing. 
Its flight is rapid and peculiar, being performed by succes- 
sive jerks, which render it easily distinguishable from the 
Gulls, amongst whom it is so often seen mingled, in watch- 
fulness of their movements. ‘This species is widely distri- 
buted throughout the higher Arctic Regions, and was met with 
in all the late Expeditions to the polar seas, both in Europe 
and North America. 
Puiate 101.* represents the Arctic Skua of the natural size, 
and in the matured plumage. 
Bill having the cereous part greyish-black, with the tip 
darker ; depressed, and broad at the base; grooved as 
in the Cat. Pomarinus, and forming three plates; lower 
mandible laterally grooved for two-thirds of its length ; 
the symphasis forming a slight angle ; commissure 
straight to a little beyond the line of the nostrils, when 
it becomes curved in both mandibles. Irides chesnut- 
brown. Forehead, chin, cheeks, sides of the neck, and 
breast, pale straw-vellow. Belly yellowish-white, pass- 
ing towards the abdomen and upon the flanks into 
greyish-brown. Feathers of the upper part of the neck 
wiry and acuminate, forming a kind of collar. Crown 
of the head, nape of the neck, back, quills, tail, and 
under tail-coverts, brownish-black, tinged with grey, 
deepest upon the head and the extremities of the wings 
and tail. Shafts of the quills and tail-feathers whitish 
to near their points. The two middle tail-feathers much 
produced, and tapering to a fine point. Wings, when 
closed, very little longer than the lateral feathers of the 
