The Cassidae are a taxonomic family of medium-sized, large, and sometimes very large sea snails commonly called helmet snails or bonnet snails. These are marine gastropod mollusks in the superfamily Tonnoidea and the clade Littorinimorpha.
Tonna is a genus of large sea snails, marine gastropod molluscs in the family Tonnidae, the tun or cask shells.
Gibbula is a genus of small sea snails, marine gastropod molluscs in the subfamily Cantharidinae of the family Trochidae, the top snails.
Clanculus is a genus of sea snail, marine gastropod molluscs of the family Trochidae, the top shells.
Polinices is a genus of predatory sea snails, marine gastropod molluscs in the subfamily Polinicinae of the family Naticidae, commonly known as moon snails.
Turbinella is a genus of very large sea snails with an operculum, marine gastropod mollusks in the subfamily Turbinellinae of the family Turbinellidae.
Janthina is a genus of small to medium-sized pelagic or planktonic sea snails, marine gastropod molluscs in the family Epitoniidae.
Cymbula is a genus of sea snails, the true limpets, marine gastropod mollusks in the family Patellidae.
Vexillum is a genus of small to medium-sized sea snails, marine gastropod mollusks in the family Costellariidae.
Purpura is a genus of sea snails, marine gastropod mollusks in the subfamily Rapaninae of the family Muricidae, the murex snails or rock snails.
Ancilla, common name the ancillas, is a genus of sea snails, marine gastropod mollusks in the family Ancillariidae.
Eburna is a genus of sea snails, marine gastropod mollusks in the family Ancillariidae.
Jujubinus is a genus of sea snails, marine gastropod mollusks in the family Trochidae, the top snails.
Sinum is a genus of predatory sea snails, marine gastropod mollusks in the subfamily Sininae of the family Naticidae, the moon snails.
Tutufa is a genus of sea snails, marine gastropod mollusks in the family Bursidae, the frog shells.
Casmaria erinaceus, common name : the common bonnet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails.
Casmaria ponderosa, common name the heavy bonnet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails.
Phalium glaucum, common name the grey bonnet or glaucus bonnet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails.
Phalium, common name the bonnet shells, is a genus of large sea snails, marine gastropod molluscs in the subfamily Phaliinae of the family Cassidae, the helmet shells, bonnet shells and their allies.
Distorsio is a genus of medium-sized sea snails, marine gastropod mollusks in the family Personidae, the Distortio snails.
