GULLS. 513 
across Siberia to the Lena. Nesting in colonies in the vicinity of Lake Ladoga, 
together with the common tern, the female generally lays three or four egys, 
which may be distinguished from those of the former by the orange-red, instead of 
yellow, colour of their yolks. Whereas the species just mentioned is but a very 
occasional visitor there, the black-headed gull (LZ. ridibundus) is a common 
denizen of the British coasts, showing an especial partiality for flat shores during 
the winter, but in the spring seeking marshes for the purpose of breeding. In this 
species the head and upper part of the neck are dark brown, and the beak lake-red 
in the summer-dress; but in the Mediterranean black-headed gull (LZ. melano- 

BLACK-HEADED GULL (} nat. size). 
cephalus) the head is jet-black, and the beak coral-red, with a dark band in front 
of the angle; while the primary quills, in fully adult examples, are white, instead 
of parti-coloured. In America the group is represented by the laughing gull 
(L. atricilla), distinguished from the British species by its larger dimensions, and 
characterised by having the first three outer primaries black, with minute white 
tips. The largest member of the group is the great black-headed gull (L. ichthy- 
aétus), ranging eastwards from the Levant to China, and northwards to Mongolia. 
In length the male may measure as much as 27 inches (against 16 inches in the 
black-headed gull); and in the breeding-plumage the adult has a jet-black head 
and upper neck, the beak orange-red, passing into red at the angle of the mandible, 
VOL. IV.— 33 
