Aplysia

‖A‐plys″i‐a (�), n. [Gr. � a dirty sponge, fr. � unwashed; ἀ priv. + � to wash.] (Zoöl.) A genus of marine mollusks of the order Tectibranchiata; the sea hare. Some of the species when disturbed throw out a deep purple liquor, which colors the water to some distance. See Illust. in Appendix.