According to the World Registry of Marine Species, this superfamily comprises five families, two of which are extinct:[1] These holoplanktonic snails are found floating or swimming in tropical to subtropical open oceans and seas at a depth of maximum 200 to 300 m [2] These snails have adapted themselves to a pelagic living : The taenioglossate radula, situated at the tip of the proboscis, can be protruded to capture the prey.

They have paired, large spherical eyes, contained in a gelatinous mass, that they use to locate their prey.

This sucker has grown larger in the family Atlantidae where it serves to hold the prey.

The body size varies from microscopic (Atlantidae) to macroscopic (Carinariidae and Pterotracheidae).

Fertilized eggs are laid in mucous strings that hatch after a few days into free swimming veliger larvae (except in Firoloida desmaresti where the eggs remain attached in a tubular filament to the female body).