in taxon Myxinidae Gnathostomata <vertebrates> Craniata <chordates> respiration organ respiratory velum velum trifid and posteriorly directed lamina arising from roof of pharynx, behind posterior end of naso-pharyngeal duct; A respiratory pump found in basal craniates. Muscular scroll-like flap that moves water through median nostril and over gills this is restricted to hagfishes; structure with same name found in tunicates. UBERON:0012121 velum feeding organ