BUFFON'S or the PARASITE SKUA (_Lestris [Stercorarius] parasitica_) is considerably smaller, and more slenderly built, than the species last described, from which it is also distinguishable by the central tail-feathers. These are considerably elongated and sharp-pointed. The colour of this bird is either sooty brown, with a white throat, and a whitish or yellowish patch upon the forehead, or the upper side is sooty brown, the throat yellowish, the under side greyish white, and the region of the crop grey. This variation in the colours of different specimens seems quite independent either of age or sex. The eye is brown, beak black, cere dark leaden grey, and the foot blue-black. The length is eighteen to nineteen inches; breadth, thirty-nine to forty-two inches; length of wing, twelve inches; length of tail, seven inches. The Parasite Skua is met with in the Arctic Regions of both hemispheres. It is found in Spitzbergen and Greenland, extending thence to the middle of the coast of Norway; it occurs in Iceland; in the islands to the north of Scotland; in the Faroe Islands; off the coast of Labrador; in Newfoundland; also in Behring's Straits; and in the Sea of Ochotsk it is abundant. In England and Ireland it is but rarely seen. During the winter it is a regular visitant to the more southern coasts of the countries bordering on the North Sea, and sometimes wanders inland. Except during the breeding season, it passes its whole life on the sea. Its presence is by no means confined to coasts and rocky reefs; it remains for weeks together far out of sight of land. The unpractised observer will find but little difficulty in distinguishing the Parasite Gull, even from its nearest allies, as soon as he has witnessed the manner of its flight. Its gait when walking is hurried, but is not otherwise remarkable, and when swimming, with the exception of its dark colour, it very much resembles some of the smaller Gulls. Its flight, however, is more versatile than that of any member of the family; frequently it skims along like a Falcon, at one time giving a few rapid strokes with its wings, then sweeping onwards to a considerable distance, somewhat after the manner of a Kite; suddenly, however, it seems to shiver, or rapidly shake its wings, and precipitates itself downwards, describing a sort of arch, mounts up again, and immediately adopts a course made up of an alternation of larger and smaller arches joined beneath each other. It now shoots with great rapidity downwards, then slowly mounts again, and remains for a moment quiet, as it were exhausted; but the next instant, as though possessed by an evil spirit, it turns, and winds, and struggles, and flutters in an indescribable manner.