RI´MA, _n._ Outline of a slit-like opening.
RI´MA GLOT´TIDIS, _n._ Opening of the glottis.
RI´MA ORIS, n. Equivalent to COMMISSURE (which see).
ROS´TRUM, _n._ Bill; beak; projecting forepart of head of birds; of two
jaws, upper and lower, consisting of a frame of certain bones over which
is stretched unfeathered skinny or horny membrane, the rhamphotheca.
(9.)
ROUND´ED (_tail_), _a._ Having the central feathers longest, the rest
successively gradually and slightly shorter. A tail is _double-rounded_
when, with central feathers shorter than the next, the rest are
graduated as before.
RU´DIMENT, _n._ A beginning.
RUDIMEN´TARY, _a._ Undeveloped; imperfectly elaborated; existing only in
its beginnings.
RUFF, _n._ Set of lengthened or otherwise modified or peculiarly colored
feathers around the throat or whole neck.
RU´GA, _n._ Ridge or raised fold; wrinkle.
RUGOSE´ or RU´GOUS, _a._ Wrinkled.