375 
of the United States . 
narrowed and rounded at tip, end of both mandibles distinct; 
upper mandible not covering the margins of the lower, 
ridge broad, elevated ; nail sub-orbicular, curved, obtuse ; 
lower plane ; marginal teeth short, conic, acute : nostrils 
medial, lateral, longitudinal, large, elliptic, open, pervious, 
covered by a membrane ; tongue thick, fleshy, fimbriated on 
the sides. Head small, lora feathered ; neck moderate: body 
cylindrical. Feet central, stout; tarsi rather longer than 
the middle toe; toes moderate; webs full, entire; hind toe 
equal to a phalanx of the middle, simple, touching the ground 
at tip ; middle toe longest ; outer longer than the inner : nails 
falculate, the middle dilated into a sharp edge. Wings 
moderate, acute, sometimes spurred ; quills strong, primaries 
much longer than the secondaries ; first and second, or second 
only, longest. Tail of numerous feathers, rounded. 
Female similar to the male. Young of some species dif- 
fering extremely from the adult, and changing repeatedly. 
Moult annual, but protracted. Plumage moderately thick. 
Colors dull, more or less of light, or very dark, cinereous. 
Size large. Trachea simple. 
Habits terrestrial : keep in flocks, mostly in marshes and 
low grounds, and migrate according to season, from cold to 
temperate regions. Shy : cunning : vigilant : when sleeping 
or feeding, establishing sentinels to give warning of any dan- 
ger. Altogether diurnal. Retiring at night to the water : 
very clamorous when uniting: go to pasture by day ; feed 
principally on vegetables, which they nibble off, on roots and 
seeds ; some also on fishes, reptiles, and small aquatic ani- 
mals : commit great devastation in corn-fields, by cutting or 
rooting up the young plants. Disposed to polygamy. Build 
on the ground. Walk with less awkwardness than the allied 
genera. Swim but little, and deeper in the water, neither 
their body, feet, nor plumage being calculated for it : hardly 
ever dive, and never by choice. Flight exceedingly high, 
