Wikipedia
Laginiopsidae
The Laginiopsidae are a taxonomic family of floating and swimming sea snails, sea slugs or sea angels, pelagic marine opisthobranch gastropod mollusks in the suborder Gymnosomata, the sea angels.
These small pelagic snails lack shells (except in their early embryonic stage).
They are carnivorous, equipped with swimming parapoda (fleshy, winglike outgrowths), strong jaws and grasping tentacles, often with suckers resembling those of cephalopods.