Limacina
 Limacina is a genus of swimming predatory sea snails commonly known as sea butterflies in the family Limacinidae. This genus contains some of the world's most abundant gastropod species.Etymological meaning of the generic name Limacina is snail-like.As pelagic marine gastropods Limacina swim by flapping their parapodia inspiring the common name sea butterflies.Sea butterflies are part of the clade Thecosomata. Sea angels similar to Limacina are in the order Gymnosomata.