Lamellariinae is a subfamily of small slug-like sea snails, marine gastropod molluscs belonging to the family Velutinidae, in the order Littorinimorpha.

[1] Species with internal shell, hidden beneath a papillate mantle with lateral flaps.

These flaps are in some genera fused to enclose the shell.

They resemble dorid nudibranches, but differ by their smooth tentacles and the absence of a dorsal gill circlet.

[2] Most species are carnivores feeding mainly on ascidians, tunicates and cnidarians.