ANATIDZ. 87 
of lores, and advancing quite to the 
nostril.......... Arctonetta. (Page 108.) 
@. Feathering of forehead separated from that 
of lores by the interposition of a more or 
less extensive naked angle, or prolonga- 
tion of naked skin of the bill. 
Somateria. (Page 108.) 
f*. Tail more than half as long as wing, much graduated, the 
feathers with narrow webs and very stiff shafts, their 
bases scarcely hidden by the short coverts. 
g’. Nail of bill very small, hardly visible from above, and 
bent abruptly backward beneath the tip of the 
upper mandible; outer toe longer than middle. 
Erismatura. (Page 113.) 
1 g’. Nail of bill normal (ie. large, almost wholly visible 
from above, and not bent abruptly backward at 
tip); outer toe shorter than middle. 
Nomonyx. (Page 114.) 
e. Lores wholly or partially naked; wing more than 12.00. : 
Cairina.’ (Page 100.) 
@. Lower portion of tarsus in front without transverse scutelle. 
Dendrocygna. (Page 118.) 
6°. Tarsus longer than middle toe, without claw. (Subfamily Anserine.) 
c’. Serrations on cutting-edge of upper mandible visible from outside for 
greater portion of the tomium, the latter decidedly sinuated, or 
concave. 
a’. Bill very stout, its depth through base equal to much more than 
half the length of the culmen; color of adults white, with 
blackish primaries, or else with head and part of neck white, 
the wing-coverts plain bluish gray........... Chen. (Page 114.) 
d’. Bill weaker and more depressed, its depth through base less than 
half the length of the culmen; color of adults never white, or 
with white head, or bluish gray wing-coverts. 
Anser. (Page 115.) 
ce. Serrations on edge of upper mandible visible only near angle of mouth, 
the tomium very slightly or not at all sinuated. 
d'. Nostril near middle of nasal fosse; cutting-edge of upper mandible 
not appreciably or regularly sinuated; bill and feet always 
entirely black; head partially or entirely black; tail-coverts 
and crissum White...) Branta, (Page 116.) 
d@. Nostril at lower anterior extremity of nasal fosse; cutting-edge 
of upper mandible appreciably and regularly sinuated, or con- 
cave; bill and feet light-colored ; head white (sometimes stained 
1 Cairina Fiesine, Phil. of Zool. 1822, 260. Type, Anas moschata Linn, 
