Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles. Bryozoans, or colonial moss animals, are the only
Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles. Bryozoans, or colonial moss animals, are the only ones that can completely (*) retract it, while Phoronid tube worms extend it from their chitonous tubes.  Also found in Pterobranchs and Brachiopods, for 10 points— name this horse- shoe shaped filtering organ of simple deuterostomes.
Held in place by muscles of the mesocoel, this gas exchange and food collection organ is a U-shaped ridge around the mouth bearing ciliated tentacles.
lophophore