Crepidula, common name the "slipper limpets" or "slipper shells", is a genus of sea snails, marine gastropod mollusks in the family Calyptraeidae. This family includes the slipper snails (Crepidula), hat snails (Calyptraea), spiny slipper snails (Bostrycapulus), and cup-and-saucer snails (Crucibulum) as well as Crepipatella, Siphopatella, Grandicrepidula, and Maoricrypta.These recent changes in the definition of Crepidula are based on both DNA sequence data as well as anatomical work.