678 GREAT BLACK-BACKED GULL. 
and is plentiful during summer on the coasts of the North Sea, 
Scandinavia, and Russia, ranging as far east.as the delta of the 
Petchora, and probably to the mouth of the Yenesei (Popham). 
Southward, no nesting-places are known on the Continent, except in 
the north-west of France ; though the bird occurs in winter as far as 
the Canaries, and is met with on the Mediterranean and Black 
Seas, as well as on inland waters. Across the North Atlantic it is 
found breeding in Danish Greenland up to lat. 68° N., and has 
been observed in Baffin Bay ; while southward, it nests in Labrador, 
Maine, and on some of the great inland lakes, visiting Florida, and 
occasionally Bermuda in winter. The Bering and Okhotsk Seas are 
frequented by ZL. schistisagus of Stejneger, a species which is quite 
as large as small specimens of Z. marinus, and is often nearly as 
dark on the mantle; and it was an example of this, from Northern 
Japan, that I formerly referred to LZ. marinus. Ur. Stejneger’s fine 
species proves, however, to be closer to the Herring-Gull section of 
the family; the next link in that direction being Z. vega, which 
inhabits the eastern coasts of Siberia and visits Japan and China in 
winter. This last has a grey mantle, like Z. cachinnans, but its 
tarsi and toes are flesh-coloured instead of bright yellow. 
The nest of the Great Black-backed Gull is frequently on some 
isolated stack of rock or on an islet in a loch; and the eggs, laid in 
May, are never more than 3 and often only 2 in number; their 
colour is stone-buff, boldly blotched with dark grey and umber: 
measurements 3 by 21 in. Nothing in the way of animal food 
comes amiss to this predacious species, whether it be sickly ewes, 
weakly lambs, young or wounded water-fowl and game, eggs, or 
carrion. The majestic flight, large size, and loud querulous note of 
this species facilitate its recognition on the wing. 
The adult male has the plumage white, except the mantle, which 
is black with a tinge of slate-colour ; the scapulars and secondaries 
have white tips which form a strongly contrasted alar bar ; all the 
primaries are broadly tipped with white, the first often for 3 in., 
while the second has merely a black subterminal bar, and even the 
third sometimes has a white spot; the ‘wedges’ on the inner webs 
are greyish, as in the Herring Gulls ; bill yellow, red at the angie ; 
iris red; legs and feet flesh-colour. Length of a male 28-30 in., 
wing 19-20 in. The female is smaller, and has a less robust bill. 
The young bird is paler in ground-colour than immature Z. argen- 
tatus,and has more sharply defined mottlings. The white mirror 
on the outer primary is shown long before mature plumage is 
assumed. 
