A worm such as Echiurus, living in the sediment, extends its proboscis from the rim of its burrow with the ventral side on the substrate. The surface of the proboscis is well equipped with mucous glands to which food particles adhere. The mucus is bundled into boluses by cilia and these are passed along the feeding groove by cilia to the mouth. The proboscis is periodically withdrawn into the burrow and later extended in another direction.
a worM sUCh as echiuRuS liViNG iN The sEDImeNt exteNDS itS pROboSciS FrOm thE rIm oF its burROw WitH the ventral sIde on thE subsTrAtE thE surfACE oF tHe PrObosCiS Is WeLl equIPped WiTH MuCouS glands to WhIch food particlEs aDhere tHe mucUS Is bUndled iNto bolUseS by Cilia anD theSe are passed alonG the FeedINg GROovE by cIlia tO thE mOUtH thE probosCis Is PEriodIcally withDRaWN iNTo ThE burrow AnD lAtEr extenDed iN aNotHeR diRectiOn