Sea snails are slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell.
Neomphaloidea is a superfamily of deep-sea snails or limpets, marine gastropod mollusks. Neomphaloidea is the only superfamily in the order Neomphalida.
Trochoidea is a superfamily of small to very large vetigastropod sea snails with gills and an operculum. Species within this superfamily have nacre as the inner shell layer. The families within this superfamily include the Trochidae, the top snails. This superfamily is the largest vetigastropodan superfamily, containing more than 2,000 species.
Scissurellidae, sometimes known by the common name little slit snails, are a taxonomic family of minute sea snails, marine gastropod molluscs or micromolluscs in the clade Vetigastropoda.
Catantostomatidae is an extinct family of marine gastropods included in the Vetigastropoda and placed in the superfamily Pleurotomarioidea.
Rhaphischismatidae is an extinct family of fossil sea snails, marine gastropod molluscs in the superorder Vetigastropoda. They date from the Lower Carboniferous (Mississippian). The family contains a single genus, Raphischisma. In the Bouchet & Rocroi, 2005), this family is assigned to the Pleurotomariacea.
Peltospiridae is a small family of gastropods that used to belong to the clade Vetigastropoda, but is now included in the clade Neomphalina
Anatomidae is a family of minute sea snails, marine gastropod mollusks in the clade Vetigastropoda.
Liotiidae is a family of small sea snails, marine gastropod mollusks in the clade Vetigastropoda.
Phasianellidae, with the common name "pheasant shells" or "pheasant snails", is a family of small sea snails with calcareous opercula, marine gastropod mollusks in the subclass Vetigastropoda.
Eucyclidae is a family of gastropods in the superfamily Seguenzioidea.
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005.
Pleurotomarioidea is a superfamily of small to large marine gastropods included in the order Pleurotomariida of the subclass Vetigastropoda.
Scissurelloidea is a taxonomic superfamily of minute sea snails, marine gastropod mollusks or micromollusks in the subclass Vetigastropoda.
Seguenzioidea is a superfamily of minute to medium-sized sea snails, marine gastropod mollusks in the clade Vetigastropoda.
Trogloconcha is a genus of sea snails, marine gastropod molluscs in the family Larocheidae.
The Skeneidae are a speciose family of minute to small marine gastropod molluscs in the superfamily Trochoidea.
Margaritidae is a family of small sea snails, marine gastropod mollusks in the superfamily Trochoidea.
Hemimarginula is a genus of sea snails, marine gastropod mollusks in the family Fissurellidae, the keyhole limpets and slit limpets.
Clypeostoma is a genus of mostly small deep water sea snails, marine gastropod mollusks in the family Chilodontaidae.
