Tomopteris \To*mop"te*ris\, n. [NL., fr. Gr. to`mos a cut +
ptero`n wing (but taken to mean, fin).] (Zool.)
A genus of transparent marine annelids which swim actively at
the surface of the sea. They have deeply divided or forked
finlike organs (parapodia). This genus is the type of the
order, or suborder, Gymnocopa.
[1913 Webster]