NATATORES. 479 
ORDER VI.—NATATORES. Swimmers. 
Toes connected by membrane to the claws; the feet fitted for 
swimming; lower part of the tibia usually feathered to near the 
joint, which is bare; hind toe, however, usually elevated, and rather - 
small, except in Pelecanide ; fitted for an aquatic life, swimming 
and diving freely ; rump with well-developed oil glands. 
The order Natatores, as characterized above, embraces a large 
number of species of very varied forms, all more or less aquatic in 
their habits. A character common to all consists in the presence 
of a membrane between the toes, usually extending to the claws. 
This membrane, when found in the Grallatores, is eonfined more 
or less to the basal joint, unless Phenicopterus be an exception. 
F This genus has been variously placed in both orders, and it is still 
a question where it really belongs. The internal anatomy resem- 
bles that of the Watatores, as well as the lamellated bill and fully 
webbed toes ; the external form however, as well as habits, bring 
it nearer the Grallatores. 
The order Natatores of most authors has been divided by Bona- 
parte into two,—the Gavie and the Anseres: the former em- 
bracing species which rear their young in nests, and belong to the 
sub-class Altrices ; while the latter are Precoces, the young pro- 
curing food for themselves almost from birth. 
Gavi. — Bill without lamellz, and more or less entire; feet 
. with the toes all connected by one continuovls membrane; or the 
hind toe free, with the anterior continuously webbed. 
AnseErEs. — Bill with transverse lamellz along the edges; hind 
toe free. 
ap ie ene ape ae ANE 
Hs 
