See text The Calyptraeidae are a family of small to medium-sized marine prosobranch gastropods.

This family has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005.

Crepidula fornicata was transported to Europe on imported American oysters in the late 19th century and is now considered a significant pest in European oyster beds.

[2] Internally, the shell is distinguished by a shelf-like, cup-like, or half-cup-like structure used for muscle attachment.

Calyptraeids may form a tower of up to 25 animals, sometimes referred to as a mating chain.