DIVISIONS OF BIRDS. 50 I 



order agrees with the Ratitce of Huxley. (Ex. Ostrich, Emeu, 

 Apteryx.) 



4. Rasores or Scratchers. The Rasorial birds have usually 

 strong feet with powerful blunt claws adapted for scratching, 

 but sometimes for perching. All the four toes are present. 

 The upper mandible is vaulted, and the nostrils are pierced in 

 a membranous space at its base, and are covered by a cartila- 

 ginous scale. (Ex. Fowls, Game-birds, Pigeons.) 



5. Scansores or Climbers. The Climbing birds are charac- 

 terised by the structure of the foot, in which two toes are 

 turned backwards and two forwards, so as to give the bird 

 unusual facilities in climbing trees. (Ex. Parrots, Toucans, 

 Woodpeckers.) 



6. Insessores or Perchers. The Insessorial or Passerine birds 

 are characterised by having slender and short legs, with three 

 toes before and one behind, the two external toes generally 

 united by a very short membrane, and the whole foot being 

 adapted for perching. This is by far the largest order of birds, 

 and includes all our ordinary songsters, such as the Thrushes, 

 Linnets, Larks, &c., together with the Swallows, Humming- 

 birds, and many others. 



7. Raptores or Birds of Prey. The Birds of Rapine are 

 characterised by their strong, curved, sharp-edged and sharp- 

 pointed beak, adapted for tearing animal food ; and by their 

 robust legs armed with four toes, three in front and one be- 

 hind, all furnished with long, strong, crooked claws or talons. 

 (Ex. Eagles, Hawks, Owls.) 



8. Saururce. The metacarpal bones are not anchylosed 

 together, and the tail is longer than the body, and consists of 

 numerous free vertebrae, without a terminal ploughshare-bone. 

 The only member of this order is the extinct Arcfuzopteryx. 



ORDER I. NATATORES. The order of the Natatores, or 

 Swimmers, comprises a number of birds which are as much or 

 even more at home in the water than upon the land. In 

 accordance with their aquatic habit of life, the Natatores have 

 a boat-shaped body, usually with a long neck. The legs are 

 short, and placed behind the centre of gravity of the body, 

 this position enabling them to act admirably as paddles, at the 

 same time that it renders the gait upon dry land more or less 

 awkward and shuffling. In all cases the toes are " webbed " 

 or united by membrane to a greater or less extent (fig. 217, A). 

 In many instances the membrane or web is stretched com- 

 pletely from toe to toe, but in others the web is divided or 

 split up between the toes, so that the toes are fringed with 



