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.
Buccinum is a genus of medium-sized sea snails, marine gastropod molluscs in the family Buccinidae, the true whelks.
Trochus is a genus of medium-to large-sized, top-shaped sea snails with an operculum, of the family Trochidae, the top snails.
Thais, sometimes known by the common names dog winkles or rock shells, is a genus of medium to large predatory sea snails with an operculum, marine gastropod mollusks in the family Muricidae.
Lambis is a genus of large sea snails sometimes known as spider conchs, marine gastropod mollusks in the family Strombidae, the true conch family.
Lima is a genus of file shells or file clams, marine bivalve molluscs in the family Limidae, the file shells, within the subclass Pteriomorphia.
Turbo is a genus of large sea snails with gills and an operculum, marine gastropod molluscs in the family Turbinidae, the turban snails.
Patella is a genus of sea snails with gills, typical true limpets, marine gastropod mollusks in the family Patellidae, the true limpets.
Semicassis is a genus of medium-sized predatory sea snails, marine gastropod molluscs in the subfamily Cassinae within the family Cassidae, the helmet snails and bonnet snails.
Cassis, common name the helmet shells, is a genus of very large sea snails, marine gastropod mollusks in the family Cassidae, the helmet shells and their allies. This is the type genus of the subfamily Cassinae.
Pugilina is a genus of large sea snails, marine gastropod mollusks in the family Melongenidae, the crown conches and their allies.
Volema is a genus of sea snails, marine gastropod molluscs in the family Melongenidae, the crown conches and their allies.
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.
Galeodea is a genus of large sea snails, marine gastropod mollusks in the subfamily Cassinae of the family Cassidae.
Casmaria, is a genus of medium-sized sea snails, marine gastropod molluscs in the subfamily Phaliinae of the family Cassidae, the helmet shells and their allies.
