NATATORES. 257 



From the Anatina we are led by easy gradations of charac- 

 ter to the fourth subfamily Fuligulina, embracing TEM- 

 MINCK'S second section of Canards, or Ducks with a lobated 

 hind toe. These are more pelagic in their habits than the 

 foregoing groups, and in form also make a more evident ap- 

 proach to the typical families of the present order ; their 

 legs, by being thrown far backwards, and much out of the 

 centre of gravity, render their progress upon land constrained 

 and awkward, but essentially contribute to their power of 

 swimming. With them the neck becomes shortened and 

 thicker, and the gullet more capacious, proportionate to the 

 larger kind of food upon which they subsist. They swim 

 remarkably well, rarely quit the water, and are in the con- 

 stant habit of obtaining their food by diving. Nearly allied 

 to these last in the backward situation of the legs, the form 

 of the feet, lobated hind toe, and aquatic habits, are the 

 members cf the genus Mergus, forming the fifth subfamily 

 Mergina. They differ, however, in the form of the bill, 

 which in a great measure loses the breadth and depression 

 seen in the three immediately preceding groups of the Ana- 

 tidce, and becomes more like that of the succeeding families 

 of the order ; at the same time that the connexion with the 

 first subfamily Anserina is preserved by the Smew (Mergus 

 albellus)) whose bill is almost of an intermediate form between 

 that of some of the smaller Geese and the other species of 

 Mergi. 



The AnaiidcB are distinguished from the rest of this or- 

 der, not only by the broad and depressed form of the bill, 

 but by its softer consistence, and being entirely clothed by 

 an epidermis, or skin, with the exception of the dertrum, or 

 terminating nail. Its structure is also peculiar in another 

 ssential point, and differs from that of all other birds in the 

 Iges being furnished with lamellar plates, more or less de- 

 published in the Fourth Number of the Journal of the Royal Institution 

 ' Great Britain. 

 VOL. II. R 



