290 VERTEBRATE ANIMALS, 
VII. Raptores or Birds of Prey, characterised by having a 
strong, sharp-edged, and sharp-pointed beak, adapted for tear- 
ing animal food, and by their robust legs, armed with four toes, 
three in front and one behind, all of which are furnished with 
long, strong, crooked claws or talons. (£2. Eagles, Hawks, Owls.) 
VIII. Saurure or Lizard-tailed Birds, characterised by 
having a tail longer than the body, composed of numerous 
distinct and movable vertebrze, each of which carries a single 
pair of quill-feathers. (This order includes only the remarkable 
fossil bird, the Archaeopteryx.) 
ORDER I, NATATORES.—The order of the Swimming Birds 
comprises birds which are as much at home in the water as upon 
land, or even more so. In accordance with their aquatic mode 
Fig. 154.—Natatores. A, Foot of the Cormorant; B, Beak of the Bean-Goose 
(after Jardine). 
of life, the Vatatores have a boat-shaped body, generally elon- 
gated, and usually having a long neck. The legs are short, and 
are placed behind the centre of gravity of the body ; this posi- 
tion enabling them to act admirably as swimming-paddles, at 
the same time that it renders the gait upon dry land compara- 
tively awkward and shuffling. The toes in all the Vatatores are’ 
webbed to a greater or less extent, or, in other words, are united 
by a membrane (fig. 154, A). In many the web or membrane 
between the toes is stretched completely from toe to toe, but in 
others the membrane is divided between the toes, so that the 
feet are only imperfectly webbed. As their aquatic mode of life 
exposes them to great reductions of temperature, the body in the 
Natatorial birds is closely covered with feathers, with a thick 
covering of down next the skin. They are further protected 
