102 
NATURAL HISTORY. 
[EAST. ZOOL, 
wings, their bill covered with a soft skin, and furnished 
on the edge with a series of plates, through which they 
filter the water, and thus separate their food. The Swans 
and Geese have beautifully formed, long necks; the 
Cereopsis has the base of the beak covered by a yellow skin, 
and the Hydrobates the hind toe large, and webbed be¬ 
neath. The Merganser ( Mergus ) has a slender, serrated 
bill; and the Flamingo ( Phcenicopterus ) combines the long 
legs of the Waders with the shining velvet plumage, com¬ 
pressed legs, and serrated bill of the Ducks. 
The family of the Divers (Colymbidee) have very mode¬ 
rately feathered short wings, and the legs placed so far back 
on the body, that they can assume an erect position. 
The bill is compressed* at the tip, and smooth. They 
live constantly on the water, and dive for their food. 
The Grebes have a very silky plumage, and the toes se¬ 
parate, and fringed on the side by a membrane. These 
birds live on lakes, and are said to carry their young under 
their wings when alarmed. The Finfoot ( Podoa ) has the 
feet of the Grebes, but the tail is longer, and the claws 
sharp; the Divers (Colymbus) have completely-webbed-feet, 
and live on the sea-coast. 
The family of Auks ( Alcidce ) have, like the Divers, 
very short wings, and the legs placed far behind the centre 
of the body, which enables them to stand nearly erect, but 
they have the toes all united by a web. In some the 
wings are covered with feathers, and have no hind toe, as 
the Guillemots (Uria ), Penguins ( Spkeniscus ), and Puf¬ 
fins ( Fratereula ). Others have the wings covered with 
small scale-like feathers, and all the four toes directed for¬ 
wards. 
The remainder of the web-footed Birds have very long 
wings, which enable them to suspend themselves in the air 
for a great length of time, so that it almost appears to be 
their proper sphere, as they are seldom seen on the ground 
except in the breeding season. 
The family of Gulls (Laridas) have the hind toe free, 
and sometimes very short and rudimentary, and a com¬ 
pressed bill. The Petrels have the bill strongly hooked 
at the end ; their hind claw is placed immediately on the 
tarsus, without any toe. Of all the Water birds, these 
keep more especially out at sea; they often fiv so far 
