Hooded Merganser . 35 
It nests in holes in trees and stumps near the banks 
of lakes, and lines its nest with grasses, feathers and 
down. When the young birds are hatched they are 
carefully transported to a secluded pool by the mother, 
who carries them in her bill by the neck or wing. 
The eggs, 6 to 10 or even more, are white or buffy and 
measure 2°05 x 1°70. 
Subfamily ANATINA, 
The river Ducks have a broad flattened bill with fine 
comb-like lamellae in both mandibles; the tarsi are 
scutellate, and shorter than the middle toe without claw ; 
the hallux is without a lobe, and the sexes are generally 
unlike. 
Key oF THE GENERA AND SPECIES. 
A, Bill distinctly spatulate, broad at the end, narrow at the base 
Ks (Spatula). S. clypeata, p. 46. 
B. Bill more or less parallel-sided, not spoon-shaped. 
a. Tail graduated for more than one-third of its total length, 
tail-feathers sharp-pointed. 
al Fourteen tail-feathers; speculum green and black 
(Mareca). M. americana, p. 40. 
b! Sixteen tail-feathers. 
a? Bill longer than the middle toe without claw; tail very 
long and produced in, adult male (Dafila). 
D. acuta, p. 47. 
b? Bill shorter than the middle toe without claw ; speculum 
white (Chaulelasmus). C. streperus, p. 38. 
b. Tail graduated less than one-third of its total length; tail 
feathers sharp-pointed. 
Larger, wing over 8 (Anas). 
Head and neck glossy green. A. platyrhynchos, p. 36. 
3 in winter. 
al 
a? 
b? Head streaked with fuscous and buffy. 
a? Below mottled, dusky and grey. A. platyrhynchos, p. 36. 
3 in eclipse and ? 
b? Below mottled, dusky and brown. A. f. maculosa, p. 38. 
bt Smaller, wing under 8. 
a? No blue on wing; speculum green (Nettion). 
N. carolinensis, p. 41. 
Dp 2 
