a1. With a long crest; tarsus almost naked. ... Clamator (p. 364)
a2. Without a crest; tarsus more or less feathered at base.
b1. Secondaries shorter, in closed wing, scarcely exceeding half
the length of primaries. ... Cuculus (p. 370)
b2. Secondaries longer, in closed wing, equaling two-thirds the
length of primaries or more.
c1. Plumage never entirely black; bill at nostril wider than deep,
or at least not deeper than wide.
d1. Larger, length 300 mm. or more; plumage banded or barred,
hawk-like in both sexes. ... Hierococcyx (p. 368)
d2. Smaller, length 250 mm. or less.
e1. Tail slightly forked, outer feather short; plumage black
with a white bar on inner webs of primaries. ... Surniculus
(p. 365)
e2. Tail rounded; plumage never black.
f1. Larger; tail, about 120 mm.; plumage rather dull,
never metallic bronze nor violet.
g1. Young and adult differently colored; bill compressed;
tail-feathers of the same length throughout. ... Cacomantis
(p. 374)
g2. Young and adult similar; bill stout, not compressed;
tail-feathers narrower near their tips. ... Penthoceryx
(p. 373)
f2. Smaller; tail, about 75 mm.; plumage bright
metallic bronze or violet; abdomen strongly barred with
white. ... Chalcococcyx (p. 375)
c2. Plumage entirely black in the male, barred in the female,
with ten or more buff bars on the tail; length, 250 mm. or more;
bill at nostril decidedly deeper than wide. ... Eudynamys (p. 377)
Genus CLAMATOR Kaup, 1829.
A pointed occipital crest; wing short and rounded, primaries extending
but little beyond the secondaries; tail much longer than wing;
tail-feathers graduated; sexes similar in color.