KEEL-BREASTED BIRDS. 249 
the toes except the hind one being connected by a web 
(Fig. 285). They are distinguished by the bill, which is 
broad and flattened, covered with a tender, sensitive cov- 
ering. The edges of both mandibles are furnished with a 
series of fine, tooth-like plates that interlock and form a 
strainer ; the upper mandible ends in a rounded nail. 
The hooded merganser, eider-duck (Somateria mollis 
sima), and the Labrador duck (Camptolemus), are represent- 
atives; the latter is remarkable as having become extinct 
within a few years. It ranged as far south as New Jersey. 
The wood-ducks (Azx sponsa) are found all over the United 
States, and winter in the South. The nest is occasionally 
placed in hollow trees, in which case they bring the young 
down in their beaks. 
The Kerguelen’s Land teal (Q. Zatoni)* is peculiar to 
that country and the Crozet Islands. 
The Canada goose (Branta Canadensis) is the common 
wild goose of North America. They attain a length of 
about three feet, and migrate south in the winter, flying 
in long lines or triangles, generally led by a drake. _ They 
nest in timber along streams. The brant, snow, ross, and 
black geese are allied forms. 
The swans are characterized by long, snake-like necks 
that add to the grace and beauty of their appearance. The 
trachea or windpipe is consequently extremely long, espe- 
cially in the trumpeter, in which it enters a cavity in the 
breast-bone, makes a turn, forming a large coil, finally lead- 
ing to the lungs. 
The whistling swan (Cygnus Americanus) ranges over 
North America. 
* In Three Isle Harbor, Kerguelen’s Land, Professor Moseley ap- 
proached a flock of these birds to shoot them ; having never seen man 
before, they ran at him in lines, seven in a row, each led by a drake, 
and gathered about him like farm-yard fowl, gazing with apparent aston- 
ishment. When the nests were approached, they fluttered away, as if 
injured, a trick common in many of our birds. 
