\Hy`dro*me*du"sa\, n.; pl. {Hydromedus[ae]}. [NL.
See {Hydra}, and {Medusa}.] (Zo["o]l.)
Any medusa or jellyfish which is produced by budding from a
hydroid. They are called also {Craspedota}, and {naked-eyed
medus[ae]}.
Note: Such medus[ae] are the reproductive zooids or
      gonophores, either male or female, of the hydroid from
      which they arise, whether they become free or remain
      attached to the hydroid colony. They in turn produce
      the eggs from which the hydroids are developed. The
      name is also applied to other similar medus[ae] which
      are not known to bud from a hydroid colony, and even to
      some which are known to develop directly from the eggs,
      but which in structure agree essentially with those
      produced from hydroids. See {Hydroidea}, and
      {Gymnoblastea}.