_Cotyle_, BOIE, Isis, 1822, 550. (Type, _Hirundo riparia_, L.)
GEN. CHAR. Bill small; nostrils lateral, overhung by a straight-edged
membrane. Tarsus about equal to middle toe without claw; feathered at
upper end, especially on inner face, and having also a small tuft of
feathers attached to posterior edge near the hind toe. Middle toe with
basal joint adherent externally to near the end, half-way internally,
the claws comparatively little curved, the lateral reaching beyond the
base of the middle. Tail slightly forked. Color dull lustreless brown
above, in _riparia_ white beneath with gray pectoral band. Nests in
holes in banks; eggs white.
[Line drawing: _Cotyle riparia._
20641]
Many American birds have been referred to _Cotyle_, but the only one
really belonging to the genus is the cosmopolitan _C. riparia_. The
peculiarity of the genus consists essentially in the tuft of tarsal
feathers at the base of the hind toe, and the unusual length of the
lateral claws, combined with the lateral nostrils overhung by
membrane. By these characters the genus is very easily distinguished
from _Stelgidopteryx_.
Cotyle riparia, BOIE.