respiratory velumGo to external page http://purl.obolibrary.org/obo/UBERON_0012121
A respiratory pump found in basal craniates [ http://en.wikipedia.org/wiki/http://palaeos.com/vertebrates/glossary/glossaryUV.html ]
Muscular scroll-like flap that moves water through median nostril and over gills
trifid and posteriorly directed lamina arising from roof of pharynx, behind posterior end of naso-pharyngeal duct;
this is restricted to hagfishes; structure with same name found in tunicates.