b. Tail elongated, a little forked … Chordeiles.
B. Setirostres. Rictus bristled.
III. Aerial. Tarsi short, more or less clothed.
a. Wings normal, second and third quills longest.
1. Tail moderate, rounded at tip … Antrostomus.
2. Tail elongated, even at tip … Stenopsis.
3. Tail very long, forked or bifurcate … Hydropsalis.
b. Wings abnormal in male; outer six quills nearly equal … Heleothreptus.
IV. Terrestrial. Tarsi elongated, naked.
a. Bill moderately broad; nasal aperture scarcely prominent … Nyctidromus.