The Collaborative International Dictionary
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.
Wikipedia
Phoronis is one of the two genera of the horseshoe worm family ( Phoronidae), in the phylum Phoronida. The body has two sections, each with its own coelom. There is a specialist feeding structure, the lophophore, which is an extension of the wall of the coelom and is surrounded by tentacles. The gut is U-shaped. The diagnostic feature that distinguishes this genus is the lack of epidermal invagination at the base of the lophophore. These worms are filter feeders.
Its larva is an Actinotrocha.