Rostellum \Ros*tel"lum\, n.; pl. {Rostella}. [L. See {Rostel}.]
A small beaklike process or extension of some part; a small
rostrum; as, the rostellum of the stigma of violets, or of
the operculum of many mosses; the rostellum on the head of a
tapeworm.
[1913 Webster]