NATATORES. 257 
From the Anatina we are led by easy gradations of charac- 
ter to the fourth subfamily Fuligulina, embracing TEmM- 
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- 
tide, 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 Anatide are distinguished from the rest of this or- 
der, not only by the broad and depressed form of the biil, 
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 
essential point, and differs from that of all other birds in the 
edges being furnished with lamellar plates, more or less de- 
a 
published in the Fourth Number of the Journal of the Royal Institution 
of Great Britain. 
VOL. II. R 
