Scyllaea \Scyl*lae"a\, n. [NL. See {Scylla}.] (Zool.) A genus of oceanic nudibranchiate mollusks having the small branched gills situated on the upper side of four fleshy lateral lobes, and on the median caudal crest. [1913 Webster] Note: In color and form these mollusks closely imitate the fronds of sargassum and other floating seaweeds among which they live. [1913 Webster]