232 VERTEBBATA. 



Ardeida. Nycticorax. Tigrisoma. 



Cancroma (Boatbill). Botaurus (Bittern). Ardea (Heron.Egret), 



Palamedeidce. 

 Opistholophus = 



Chauna. 

 Palamedea. 



Order IX. ANSEKES. 

 NATATORES. 



Legs mostly short, naked above the knee ; toes webbed, the hind 

 toe, except in the Steganopoda, free. 



The legs are placed behind the centre of gravity, so that many 

 can only walk in an erect position. The body is heavy, and 

 covered with a thickish coating of down beneath the feathers. The 

 anterior toes only are webbed, except in the Steganopoda, which 

 have the hind toe also united to the others ; in Podic&ps the web is 

 confined to the sides of the toes. The bill is variously formed, flat, 

 and furnished with lamellae in the geese, with tubular nostrils in 

 the petrels, compressed in the gulls, and provided with a gular 

 pouch in the pelicans. In some of the males of the duck and 

 merganser families there is a bony dilatation of the lower part of 

 the trachea (two in the sheldrake). 



The Anseres are almost invariably water-birds ; they are mostly 

 polygamous ; the young are often capable of feeding themselves. 

 The nest, if any, is always of the rudest kind, and they lay few 

 eggs. The penguins are incapable of flight, but, aided by their 

 fin-like wings, they are the best of divers and swimmers ; on the 

 other hand, the albatross seems to pass its whole life in the air, 

 now motionless, now " performing its vigorous evolutions with- 

 out a perceptible movement of the wings," feats " simply impos- 

 sible by any mechanical means of which we have the least con- 

 ception" (Wyville Thomson*). Besides fish, many feed on sea- 

 weed, grass, &c. 



This order contains the wild swan or hooper (Cygnus fertts), 

 the tame swan (Cygnus olor), wild goose (Anser ferns), wild duck 

 (Anas boschas), widgeon (Anaspenelope), teal ( Qiterquedula crecca), 

 eider (Somateria mollissima), sheldrake (Tadorna vulpanser). po- 

 chard, or dun-bird (Fuligula ferina), scaup (Fuligula marila), 

 golden-eye (Clangula glauciori), gannet (Sula bassana), booby 

 (Sulafusca), shag (Phalacrocorax graculus\ cormorant (Phala- 

 crocorax carbo), pelican (Pelecanus onocrotalus], frigate-bird 



