Webster’s Revised Unabridged Dictionary · 1913
Glass-sponge
Glass′-sponge′ (·spŭnj′), n. (Zoöl.) A siliceous sponge, of the genus Hyalonema, and allied genera; — so called from their glassy fibers or spicules; — called also vitreous sponge. See Glass-rope, and Euplectella.