Gymnophthalmata \Gym`noph*thal"ma*ta\
(j[i^]m`n[o^]f*th[a^]l"m[.a]*t[.a]), n. pl. [NL., fr. Gr.
gymno`s naked + 'ofqalmo`s the eye.] (Zool.)
A group of acalephs, including the naked-eyed medus[ae]; the
hydromedus[ae]. Most of them are known to be the
free-swimming progeny (gonophores) of hydroids.
[1913 Webster]