Vv LARIDAE 307 
the orbits yellowish. In winter the head is streaked, and in the 
young the plumage is mottled with brown. This species extends 
over Northern Europe and most of North America, ranging to the 
south of those countries in the cold season; its representative in 
the Mediterranean and Central Asia is Z. cachinnans, with yellow 
feet and red orbits, and in Arctic Siberia Z. vegae, chiefly differing 
from the last-named in its pinkish legs. Z. audowini of the Western 
Mediterranean hag blackish feet, and a crimson bill with black band. 
L. canus, the Common Gull, found throughout Northern Europe and 
Asia,and migrating to the Mediterranean,the Nile,the Persian Gulf, 
and China, has white mirrors on the first three primaries, yellow 
bill, and greenish-yellow feet. It has occurred in Labrador, and 
breeds in North Britain on islands, lakes, and flat stacks, though 
rarely, if ever, on cliff-faces ; the shrill note is more lke that of the 
Herring Gull than the harsh ery of our Black-backs. The smaller and 
darker L. brachyrhynchus occupies North-Western America, reaching 
California in winter; the paler Z. delawarensis, with a subterminal 
black band on the yellowish bill, frequents lakes and marshes in 
North America, and breeds towards the north ; LZ. californieus, with 
little black on the beak, inhabits western North America. 
Of the Black-backed Gulls, Z. marinus, the Great Black-back, 
largest of the Family except Z. glaucus, is found from Arctic Europe 
to North-East America, migrating as far as the Mediterranean, the 
Canaries, and Florida; it has a grey wedge on the primaries 
hke the Herring Gull, and pinkish feet. Somewhat scarce in 
Britain in summer and comparatively non-gregarious, it is noted 
for its fierceness, and will even attack sheep. The smaller 
L. dominicanus, with olive feet, ranges from lat. 10° S. in South 
America to South Africa and New Zealand, with the correspond- 
ing Antarctic Seas; LZ. schistisagus of the North Pacific being 
intermediate between this and the next species. ZL. fuscus, the 
Lesser Black-back, found both on our shores and inland, has 
yellow feet; its main range covers North Europe, excluding Ice- 
land; but it even breeds in Morocco and on the Red Sea, extend- 
ing in winter still further southwards. The similar Z. afinis of 
North Russia and West Siberia, with coarser feet, migrates to 
Somaliland, India, and occasionally other districts; the very 
stout-billed ZL. occidentalis represents our species on the Pacific 
coast of North America. 
Mr. Saunders’s next section contains five Gulls resembling 
