Potamididae, common name potamidids (also known as horn snails or mudwhelks) are a family of small to large brackish water snails that live on mud flats, mangroves and similar habitats.

[1] They are amphibious gastropod molluscs in the superfamily Cerithioidea.

[1] According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Potamididae has no subfamilies.

[1] Six living and a number of fossil genera are currently recognized:[1] Recent genera:[1] Fossil genera (fossils are difficult to differentiate from other cerithioideans, such as the Batillariidae): Most of the 29 living species of Potamididae show a close association with mangroves.

Most species live on mudflats, but some also climb mangrove trees.