Gymnophthalmata /(jĭm`nŏf*thăl"mȧ*tȧ)/

Gym·noph·thal·ma·ta

Gymnophthalmata

n. pl.
  1. A group of acalephs, including the naked-eyed medusæ; the hydromedusæ. Most of them are known to be the free-swimming progeny (gonophores) of hydroids. (Zool.)