NORTH AMERICAN BIRDS. 
I. Distance from posterior end of 
nostril to loral feathers 
equal to or greater than 
length of nostril; anterior 
outline of loral feathering 
strongly convex. 
Histrionicus. (Page 107.) 
E. Distance from posterior end of 
nostril to loral feathers less 
than half the length of the 
nostril; anterior outline of 
loral feathering forming a 
nearly straight line, run- 
: ning obliquely backward 
and downward from near 
nostril to corner of mouth. 
Clangula. (Page 106.) 
sy’. Distance from tip of bill to loral feather- 
ing greater than graduation of tail. 
i‘, Distance from posterior border of 
nostril to angle of mouth much 
less than half the distance from 
anterior border of nostril to tip 
of upper mandible. 
P, Width of bill at base equal to 
one-half the length of cul- 
men ; speculum plain white. 
Camptolaimus. (Page 
107.) 
2. Width of bill at base much less 
than one-half the length of 
the culmen ; speculum dark- 
colored (steel-blue or violet 
in male), bordered before 
and behind by a white bar. 
Eniconetta. (Page 107.) 
Rk. Distance from posterior border of 
nostril to angle of mouth equal 
to or greater than distance from 
anterior end of nostril to tiv of 
upper mandible. 
Oidemia. (Page 110.) 
i, Feathering of lores reaching anteriorly to or be- 
yond posterior end of nostril, or else tertials fal- 
cate, or plumage barred with black and brown. 
7. Feathering of forehead continuous with that 
