185 
COLYMBID^E, OR DIVERS. 
Succeeding the extensive and generally distributed 
family of the Ducks and Goosanders, we place 
another, much more limited in numbers, but of 
habits even more peculiarly aquatic. They are 
all most expert divers, as their title indicates, live 
entirely on the water, except during the process of 
incubation, and undergo a periodical change of plu- 
mage in one form or another. The different modi- 
fications of form, though limited, are distributed 
over the world, hut are scarcely employed in any 
economical purpose. The skins of the larger species 
are sometimes dressed and used as ornaments. We 
have only two genora entering tlio British list, the 
first, the True Divers, have the body flat and heavy, 
and when stretched out, tapering and dart-like ; 
the wings small, sharp-pointed, and stiff, admirably 
adapted for progress under water, at the same time 
capable of quickly transporting their owners over 
land when required. The legs are placed still more 
backward than in the Sea-Ducks and Goosanders, 
so as almost to preclude the possibility of walking, 
while they are calculated to give their whole pro- 
pelling force to the body of the bird on the water ; 
the tarsus is very thin and flattened, the webbed 
foot very ample, and constructed so as to fold when 
