KEEL-BREASTED BIR&S. 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 (Camptolcemus) , 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 (Aix 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. Eatoni] * 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. 



