Source : Webster's Revised Unabridged Dictionary (1913)

Phoronis \Pho*ro"nis\, n. [NL., fr. L. Phoronis, a surname of
   Io, Gr. ?.] (Zo["o]l.)
   A remarkable genus of marine worms having tentacles around
   the mouth. It is usually classed with the gephyreans. Its
   larva ({Actinotrocha}) undergoes a peculiar metamorphosis.