Tail much rounded, the middle feathers being an inch longer than the lateral; bill of moderate length, slender, black; feet vermilion; head, neck, all round, lower parts, rump and tail, white, the lower parts tinged with pink, which soon fades; a narrow collar of black; fore part of back, scapulars, and both surfaces of wings light greyish-blue; tips of scapulars and secondaries white.
Adult, 14; wing 101/2.
Arctic Seas.
Larus Rossii, Cuneate-tailed Gull, Swains. & Rich. F. Bor. Amer. v. ii. p. 427.
Ross's Gull, Larus Rossii, Aud. Orn. Biog. v. v. p. 324.
*** Tail even.
443. 3. Larus Bonapartii, Richardson. Bonaparte's Gull.
Plate CCCXXIV.
Bill slender, black; feet orange, tinged with vermilion; head and upper part of neck all round greyish-black, that colour extending half an inch lower on the throat than on the occiput; a white band divided by a narrow black line margining the eye behind; lower part of neck all round, anterior edge of wing, alular, smaller coverts on the carpal margin, four outer primary coverts, shaft and inner web of outer primary, both webs of second, inner webs of third and fourth, rump, tail, and all the lower parts, white; back, scapulars, and wings light greyish-blue; outer web of first quill, excepting a small portion toward the end, its tips to the length of half an inch, black, as are the ends of the next six, which however have a small tip of white, the black on some of them being an inch long, and running along the inner edge to a considerable extent. Female somewhat smaller, similar to the male, but with the head and upper part of the neck umber-brown. Young in second plumage with the bill greyish-black, the feet flesh-coloured; head and neck greyish-white; a small patch of black behind the eye; upper parts dull bluish-grey, many of the wing-coverts greyish-brown, edged with paler; quills as in the adult; rump and tail white, the latter with a broad band of black at the end, the tips narrowly edged with whitish.
Adult, 141/8, 321/4.