506 MANUAL OF ZOOLOGY. 



richly supplied with filaments of the fifth nerve, and doubtless 

 serves as an efficient organ of touch. The feet are furnished 

 with four toes, of which three are turned forwards, and are 

 webbed, whilst the fourth is turned backwards, and is free. 

 The trachea in the males is often enlarged or twisted in its 

 lower part, and co-operates in the production of the peculiar 

 clanging note of most of these birds. The body is heavy, and 

 the wings only moderately developed. 



The groups of the Ducks (Anatida), Geese (Anserince], 

 and Swans (Cygnidtf), are too familiar to require much special 

 notice. The Anatidtz, or true Ducks, have the hallux fur- 

 nished with a very narrow membranous lobe, and the laminae 

 of the upper mandible generally projecting. As examples may 

 be taken the Mallards and Teals (Boschas), the Widgeons 

 (Mareca), the Shoveller (Anas), and the Pin-tail Ducks (Dafila). 

 The Sea-ducks (Fiiligulintz] frequent the sea chiefly, and have 

 the hallux furnished with a wide membranous lobe. Good 

 examples are the Eider-duck (Somateria\ the Surf-duck 

 (Oidemia), the Canvass-back Duck, and Pochard (Fuligula), 

 and the Golden-eye (Clanguld). 



The Anserince are distinguished from the Ducks chiefly by 

 their stronger and longer legs, arid comparatively shorter wings. 

 Good examples are the Grey Lag (Anser ferus\ the Canada 

 Goose (A. Canadensis], the Bean-goose (A. Segetum), and the 

 Snow-goose (A. hyperboreus). All the domesticated varieties of 

 Geese appear to be undoubtedly descended from the " Grey 

 Lag " Goose, a common wild species which is found in marshy 

 districts in Europe generally, in [Northern Africa, and as far 

 east as Persia. 



In the Swans the neck is extremely long, and the legs are 

 short. In the Hooper Swan \Cygnus ferus) the sternal keel is 

 double, and forms a cavity for the reception of a convoluted 

 portion of the trachea. This is not the case, however, with 

 the Mute Swan (C. olor\ the Black Swan (C. atratus), or the 

 Trumpeter Swan (C. buccinator), all well-known members of 

 the group. 



The Flamingoes, however, forming the group of the Phcenicop- 

 terida, require some notice, if only for the fact that the legs are 

 so long and slender that they have often been placed in the 

 order Grallatores on this account. The three anterior toes, 

 however, are webbed or completely united by membrane, and 

 the bill is lamellate, so that there can be little hesitation in 

 leaving the Flamingo in its present position amongst the Nata- 

 tores. The bill is singularly bent, both mandibles being sud- 

 denly curved downwards from the middle. The common 



