THE SKUA. 285 
The only species ot Rissas necessary for us to describe is the 
Kittiwake (Aéssa tridactyla, Fig. 105), which has the top of the head 
black, its neck, tail, and lower parts of a white hue; its back and 
wings are bluish grey, and its beak and feet vermilion red. It is 
called the Laughing Gull, on account of its cry, and is most easily 
tamed... It is widely spread all over Europe, and builds its nest on 
the coast at the mouths of rivers. It is only a visitor in France and 
Germany, but in Holland it is found as a permanent resident. Owing 
Fig. 105.—Kittiwake. 
to this species possessing great diversity of plumage at different ages, 
this Bird has received several names, and been divided into as many 
species, which modern research has proved to be erroneous. 
The Grey Kittiwake (Zarus canus) is often called the Sea Pigeon. 
Its plumage is of a beautiful white colour, with a grey back. It is 
common in summer in the regions of the Arctic Circle; in autumn 
and winter it is found on the sea-coasts of temperate Europe. 
The Skua, or Dung-bird (Stercorarta), is remarkable for its stout 
bill, which is nearly cylindrical, and covered with a membrane from 
‘the base as far as the nostrils; the upper mandible is convex, 
hooked, and armed at the extremity with a crooked point, which 
almost appears as if it was supplementary. These birds principally 
