Cymbuliidae is a family of pelagic sea snails or "sea butterflies", marine gastropod mollusks in the superfamily Cymbulioidea.
Instead of an external calcareous shell, they possess a pseudoconch, consisting of conchiolin, a cartilaginous tissue. The mantle and the gill have disappeared as well. They breathe through the skin. They prefer warm water.
Cymbuliidae are found in all marine waters between -54 and 55ðN.
The family Cymbuliidae consists of two following subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005):
Genera within the family Cymbuliidae include:
subfamily Cymbuliinae
subfamily Glebinae