314 LARIDH, GULLS.—GEN. 281-5. 
with blackish, and bill often black. Length 16-20 inches; wing 11-13; 
bill 14-14; tarsi about the same, and rather shorter than the middle toe and 
claw. Quite different from any other species. Arctic America and Europe, 
coastwise, rarely S. to U. S. in winter. Sw. and Ricu., F. B.-A. ii, 419; 
Nurr., ii, 301; Aun., vii, 150, pl. 445 ; Pagophila eburnea and P. brachytarsi 
Laws. in Bp., 856; Couss, J. c. 308, 309. . . . . . . EBURNEUS. 
** Tail of the adult almost entirely’black. (Blasipus.) 
White-headed Gull. Adult with the head white, gradually merging on 
the neck and under parts into pale ash; mantle dark plumbeous; upper tail 
coverts whitish ; ends of secondaries and tertiaries white ; primaries and tail 
feathers black, some of the former usually with white specks at the end, the 
latter white at extreme tip and base; bill red, black-tipped; feet dark. 
This is the final plumage; but the blanching is very gradual and tardy, a 
more usual condition being leaden-gray all over, the mantle slate-gray, the 
quills and tail black. Very young birds are fuliginous brown, paler or 
grayish below, the feathers of the upper parts with lighter brown edges, 
the bill pale with dark tip. Length 16-20 inches; wing 13-14. Pacific 
Coast, U. S. and southward, abundant. JZ. belchert Vicors, Zool. Voy. 
Blossom, iv, 358; L. fuliginosus Goutp, Zool. Voy. Beagle, Birds, 141; 
LL. heermanni Cass., Proce. Phila. Acad. vi, 1852, 157, and Ill. 28, pl. 5; B. 
heermannt Lawr. in Bp., 848; Cours, /.c. 304. . . . . BELCHERII. 
6. Hind toe rudimentary or minute, usually without perfect claw. (?issa.) 
Kitliwake Gull. Hind toe only appearing as a minute knob, its claw 
abortive. Mantle rather dark grayish-blue ; 1st primary with the whole outer 
web, and the entire end for about 2 inches, black; next one, with the end 
black about as far, but outer web elsewhere light, and a white speck at 
extreme tip ; on the rest of the primaries that have black, this color decreases 
in extent proportionally to the shortening of the quills, so that the base of 
the black on all is in the same line when the wings are closed (a pattern 
peculiar to the species of fissa); and these all have white apex. Bill 
yellow, usually clouded with olivaceous; feet dusky olivaceous. Rather 
small; 16-18 ; wing 12 long; bill 14-14; tarsus about the same; middle toe 
and claw longer ; tail usually slightly emarginate. In winter, nape and hind 
neck shaded with the color of the mantle. Young: bill black; a black bar 
on the tail, another across the neck behind; wings and back variously 
patched with black; dark spots before and behind the eyes; quills mostly 
black. Arctic America and Europe, chiefly coastwise, very abundant; in 
winter, commonly 8. to the Middle States; breeds from New England 
northward. Sw. and Ricu., F. B.-A. ii, 423; Nurt., ii, 298; Avup., 
vii, 146, pl. 444; Lawr. in Bp., 854; Cours, /. c. 304. . TRIDACTYLUS. 
Var. xorzeBur. It is a curious fact, that the common kittiwake of the North 
Pacific usually has the hind toe better formed — sometimes nearly if not quite as 
long as in ordinary gulls, with a nearly or quite perfect, though small, claw. But 
I cannot predicate a specific character on this score, since the development of the 
toe is by insensible degrees. See Cougs, Proc. Phila. Acad. 1869, 207 (footnote). 
Bonap., Consp. Av. ii, 226; Cours, Proc. Phila. Acad. 1862, 505; Exxior, pl. 54. 
