Hydromedusae

Hydromedusa 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]}. [1913 Webster]

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}. [1913 Webster]