The Clionidae are a family of sea angels, which are a group of pelagic marine gastropods.
The Clionidae use winglike flaps for rhythmical locomotion, as if flying in the sea.
Clionidae d'Orbigny, 1851 is unfortunately also the name of a family of sponges in the order Hadromerida, class Demospongiae.
Within the ICZN there has been a proposed emendation of spelling to Clionaidae for the sponge family.
The ICZN has ruled the correct name of gastropod family is Clionidae Gray, 1847, with type genus Clione Pallas, 1774.