-gymnophthalmata-

‖n. pl. [ NL., fr. Gr. gymno`s naked + 'ofqalmo`s the eye. ] (Zool.) 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. [ 1913 Webster ]