HyalonemaHy`a*lo*ne"ma\, n. [NL., fr. Gr. ? glass + ? a thread.] (Zo["o]l.) A genus of hexactinelline sponges, having a long stem composed of very long, slender, transparent, siliceous fibres twisted together like the strands of a color. The stem of the Japanese species (H. Sieboldii), called glass-rope, has long been in use as an ornament. See Glass-rope.