Tomopteris
To*mop"te*ris\, n. [NL., fr. Gr. ? a cut + ? wing (but taken to mean, fin).] (Zo["o]l.) 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.