Gonothyraea
Diagnostic description:
Colony erect, branched or unbranched, monosiphonic or polysiphonic, stem divided into regular internodes bearing alternate hydrothecae; hydrotheca campanulate, radially symmetrical, with true diaphragm, hydrothecal margin cusped; gonophores forming degenerate medusa extruded from urn-shaped pedicellate gonotheca but remaining attached while planula develops in a sac-like meconidium with marginal tentacles