SUBFAMILY FULIGULINyS. 283 



young birds, which probably from either fatigue or hun- 

 ger have made a brief stop while migrating. 



The members of this subfamily are great divers and 

 subsist upon mollusks, fish, various grasses, and bulbous 

 roots which they procure on or near the bottom. Their 

 flesh varies greatly according to the kind and quality of 

 their food ; those subsisting upon a fish diet possess often 

 an " ancient fish-like smell " and taste, while those that 

 feed on leaves, or roots of the more delicate plants, such 

 as the wild celery, are very tender and of excellent flavor. 

 The sexes are usually very different in the hues of their 

 plumage, the principal exceptions to this being among 

 the Scoters of the genus CEdemia. There is much di- 

 versity of structure among these birds, necessitating 

 quite a number of genera, and the specific characters are 

 strongly marked, and consequently easy of recognition. 

 These Ducks feed mostly by night, the persecutions to 

 which they are subjected preventing them from obtaining 

 their food during the day, at which time, weather per- 

 mitting, they assemble in large numbers in the middle 

 of broad waters and sleep or dress their feathers. Moon- 

 light nights are favorite ones for feeding, and on such 

 occasions they visit creeks or ponds in marshes near the 

 sea. The notes uttered by these birds are harsh and 

 guttural, and the animated, inspiring quack of some of the 

 fresh-water species is never heard among them. 



KEY TO THE GENERA 

 {For North American Species.) 

 A. Hind toe broadly lobed. 



) RUFOUS-CRESTED 



u. Head with an elongated crest. j- duck. 



' Netta. 



