- the ring of ciliated tentacles encircling the mouth of a bryozoan or phoronid.
- a similar organ in a brachiopod, composed of two ciliated, spirally coiled tentacles.
- a circle or horseshoe of ciliated tentacles surrounding the mouth and used for the capture of food in minute sessile animals of the phyla Brachiopoda, Phoronida, and Ectoprocta
