Nectocalyx
Nectocalyx , noun
[New Latin, from Greek nhkto`s swimming + {not transcribed} a calyx.]
(a)
(Zoology) The swimming bell or umbrella of a jellyfish of medusa.
(b)
(Zoology) One of the zooids of certain Siphonophora, having somewhat the form, and the essential structure, of the bell of a jellyfish, and acting as a swimming organ.