Not figured.
Bill robust, compressed, yellow, with an orange-red patch toward the
end of the lower mandible; iris light hazel; feet flesh-coloured;
head, neck, lower parts, rump, and tail pure white; back and wings
light greyish-blue, of a deeper tint than in L. argentatus; edges of
the wings and extremities of the quills white; first seven quills
greyish-black toward the end, that colour including the outer webs and
the greater part of the inner of the two first, and on the rest
gradually diminishing, so as on the seventh merely to form a
subterminal bar; the first quill with a patch of white on both webs
near the end; the tips of all white. Young male in winter with the
bill black, feet flesh-coloured; upper part and sides of the head,
hind part and sides of the neck, light brownish-grey, faintly mottled
and streaked with white; upper parts in general greyish-brown,
confusedly mottled with whitish; rump white barred with brown; primary
quills greyish-black, without white at the end; secondary quills
similar, more grey toward the base, margined and tipped with white,
undulated with brown; tail greyish-black, tipped with whitish; lower
parts greyish-white, mottled with greyish-brown. This species, which
is very intimately allied to _Larus argentatus_, is remarkable for the
great depth and comparative shortness of its bill.
_Male_, 27, wing 17-1/4, but the feathers not complete.
Western Gull, Larus occidentalis, Aud. Orn. Biog. v. v. p.
320.