The Pneumodermatidae are a family of sea angels, or small floating predatory sea snails or sea slugs. They are pelagic marine heterobranch opisthobranch gastropod mollusks in the clade Gymnosomata.These small pelagic snails lack shells (except in their early embryonic stage). They are carnivores, equipped with swimming parapoda (fleshy, wing-like outgrowths), strong jaws, and grasping tentacles, often with suckers resembling those of cephalopods.