DUCKS. 
99 
and from tne structure and sensibility of the edges 
of these members, they are calculated to separate 
the nourishing particles from the mud, sand, or 
herbage, and to seek their food in the dark. The 
legs are placed nearly under the centre of the body, 
and consequently the greater number of the species 
walk freely ; and the feet, though they are amply 
webbed, have the membrane lining the hallux cither 
narrow or entirely wanting. We shall place first 
in this sub-family, not as typical of it, but as ap- 
parently somewhat allied to the true geese, and on 
one side leading from them, the sheldrakes, of which 
we possess two very beautiful examples, one of them, 
during the breeding season, common everywhere 
around our shores. Beforo giving the characters, 
we must, however, shortly notice an American and 
Asiatic form which is beginning to creep into our 
lists, and which would lead from the tree geese 
( Dendrocygnw ) mentioned in the description of the 
spur-winged Egyptian goose. This is the genus Den- 
dronessa, of which the beautiful summer or wood- 
duck of North America is the most familiar example, 
while another inhabiting the waters of China may 
now soon become as plentiful in our collections. 
A pair of these birds were shot some years since 
near Dorking in Surrey, * but we have no reason to 
believe that they were really accidental wanderers J 
many specimens are kept on artificial waters, and 
as in the instances of the Egyptian geese, they have 
most probably escaped. The species seems easily 
* Jenyns. 
