74 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 
*Group 4. Wing, 8.50 to 10 inches long. 
Section 1. Hind toes, with well defined membraneous lobe 
or flap; belly, white, sometimes tinged on lower part 
with dusky or gray; head, marked with more or less 
white, or brownish white. 
Head, brownish; a patch of dull white on face at base of 
bill; speculum, white (female. 
Aythya marila. Greater Scaup Duck. 
Blue-bill. Black=head. 
See No. 105. 
Aythya maria. 
Head and neck, dark glossy green; a nearly round patch of white on cheek at base 
of bill: back, black; speculum, white (male). 
Glaucionetta clangula americana. American Golden Eye. Whistler. 
See No. 108. 
Head, bluish black, or purplish blue; an irregular white patch on cheek at base of 
bill (male). Glaucionetta islandica. Barrow’s Golden Eye. 
See No. 109. 
Top of head, brown; sides of head, brownish white; speculum, gray ; bill, more 
than one and a quarter inches long (female). Aythya americana. Red=headed Duck. 
See No. 103. 
Bill. not over 1.25 long; a patch of white, or grayish white, on the head, including 
the eye; no speculum; under tail covert, white; adult males have the tail feathers long and 
pointed. Clangula hyemalis. Old Squaw. Long-tailed Duck. 
See No. 111. 
Section 2. Hind toe, with well defined membraneous lobe 
or flap; belly, white, sometimes tinged on lower part 
with dusky or gray; no white, or grayish white, on 
head. 
Head, black, glossed with green; back, grayish white, finely 
lined with black; speculum, white (male). 
Aythga marila. Greater Scaup Duck. 
Blue-bill. Black=head. 
See No. 105. 
Aythya marila nearctica. 
* For directions for measurement, see page 9. 
