OF NORTH AMERICA. 25 
Habitat — North America in general. Dur- 
ing the breeding season they frequent the in- 
land ponds and marshes, but at other times 
they are not uncommon on all the salt-water 
bays of our coast. They are good divers and 
feed upon a general course of aquatic diet. 
The resemblance of this bird to the next is 
so close that they are sometimes hardly dis- 
tinguishable. Opinions vary as to their qual- 
ities as food. Coues says they are good when 
fat. The gunners eat them, but shore men 
will even eat gulls with gusto; for my part, 
excuse me. 
220 Shot kh SCAU P DUCK: 
RUE EEE vBLUE-BILL: 
Aythya affinis. 
This bird is not easily distinguished from 
No. 21, except that it is somewhat smaller, 
measuring 15 to 18 inches in length, and under 
30 inches in extent. 
Habitat — Same as last, which it resembles 
almost exactly, except for being a little smaller. 
Like them they form rafts or flocks on the 
water, and when they rise make the air re- 
sound with the sound of their wings, but un- 
like them they prefer the more brackish 
water of the river mouths, and the great 
rivers and ponds of the interior. 
