VerbarSerpula

Any one of numerous species of tubicolous annelids of the genus Serpula and allied genera of the family Serpulidaelig They secrete a calcareous tube which is usually irregularly contorted but is sometimes spirally coiled The worm has a wreath of plumelike and often bright colored gills around its head and usually an operculum to close the aperture of its tube when it retracts