240 
LARIN-32. GAY I A. 
third ; tarsus rather short, compressed, anteriorly with nu- 
merous curved seutella ; hind toe very small and elevated, 
the fourth a little shorter than the third ; memoranes ante- 
riorly concave; claws small, slightly arched, compressed, ra- 
ther acute. Plumage full, close, soft, blended, on the back 
and wings rather compact ; wings verjr long, rather narrow, 
pointed ; tail of moderate length, emarginaie or even, of 
twelve broad, abruptly rounded feathers. 
Species of this genus occur in all climates. In the colder 
regions they are migratory like the Terns. Five species oc- 
cur in Britain. The name Gavia I have adopted from Bris- 
son. 
298. Gavia Atricilla. Blackish-grey-headed Mew. 
Bill an inch and three-fourths in length ; tarsus nearly two 
inches ; wings three inches longer than the tail ; bill and 
feet rich carmine; outer quill black, the next five with that 
colour gradually diminishing, their tips white, those of the 
outer two excepted. In winter, the back and wings light 
bluish-grey : the other parts white ; the head faintly marked 
with brownish-grey ; a black crescent before the eye, and a 
grey patch behind it. In summer, the colours similar, but 
the head and part of the neck blackish-leaden-grey, the lower 
parts tinged with rose-colour. 
Male, 17, 40, 12f, 2, 2, l-^, T \. Female, 16, 38. 
This species ranks merely as an accidental straggler, a very 
few individuals only having been seen in the south of Eng- 
land. It is said to be abundant on the coasts of the Medi- 
terranean, and, according to Mr Audubon, is plentiful in the 
southern parts of the United States. 
Larus Atricilla, Lath. Ind. Ornith.ii. 813.- — Larus Atricilla, 
Temm. Man. d’Ornith. ii. 779, iv. 483. — Laras Atricilla, 
Blackish-grey-headed Mew, MacGillivray, Brit. Birds, v. 
299. Gavia ridibunda. Brown-headed Mew. 
Bill an inch and a third in length ; tarsus an inch and three* 
fourths ; wings two inches and a half longer than the tail ; 
bill and feet rich carmine ; outer four quills and their coverts 
white, the first with the greater part of its outer margin, the 
tip, and a narrow band along its inner edge black ; on the 
next five no black on the outer w r eb, that on the tip more 
extended, the black band on the inner edge broader; the tips 
white, those of the outer two excepted. In winter, the back 
and wings light bluish-grey ; the other parts white ; the head 
