Ra´dii Accesso´rii, n. pl. Barbs of the supplementary feather.
Radio´li, n. pl. Barbules (which see).
Radio´li Accesso´rii, n. pl. Barbules of the supplementary feather, aftershaft or hypoptilum.
Ra´dius, n. Outer bone of forearm.
Ra´mus, n.; pl. rami. Branch or fork. Gnathidea.
Raph´e, n. Line of separation of two parts of an organ when prominent or otherwise distinguished.
Rapto´rial, a. Pertaining to birds of prey.
Rati´tæ, n. pl. Birds with flat sternum, as ostriches, emus or cassowaries, and the apteryx.
Rau´cous, a. Hoarse-voiced.
Rec´trix, n.; pl. rectrices. Quills of the tail. (70.) (The singular is little used.)