branchial plume
From ZooTerms (Dictionary of Invertebrate Zoology)
branchial plume: (Annelida: Polychaeta) In certain Sabellidae and Serpulidae, a structure around the terminal mouth comprised of semicircular lobes bearing a few to a series of grooved, ciliated filaments or radioles, each with a series of paired ciliated side branches or pinnules functioning in filter feeding and respiration.
