Heterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs. The great majority of species of pyrams are micromolluscs.
Caecidae is a taxonomic family of very small and minute sea snails or micromolluscs, marine gastropod molluscs in the order Littorinimorpha.
The Capulidae, the cap snails or cap shells, are a taxonomic family of limpet-like sea snails, marine gastropod molluscs in the clade Littorinimorpha. Capulidae is the only family in the superfamily Capuloidea. According to taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Capulidae has no subfamilies.
Architectonicidae, common name the staircase shells or sundials, are a family of sea snails, marine gastropod mollusks in the informal group "Lower Heterobranchia" of the clade Heterobranchia.
Ringiculidae are a family of minute deep water sea snails, marine gastropod mollusks or micromollusks in the informal group Lower Heterobranchia.
Mathildidae is a family of minute sea snails, marine gastropod molluscs in the informal group of the Lower Heterobranchia.
Omalogyra is a genus of minute marine gastropod molluscs in the family Omalogyridae.
Pyramidelloidea is a superfamily of mostly very small sea snails, marine gastropod mollusks and micromollusks within the clade Panpulmonata.
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.
Tethydidae is a family of dendronotid nudibranch gastropod mollusks in the superfamily Tritonioidea.
Cylichnidae, common name the "chalice bubble snails" or "canoe bubble snails" is a family of sea snails or bubble snails, marine gastropod mollusks in the superfamily Cylichnoidea.
The Tofanellidae is a taxonomic family of sea snails, marine gastropod mollusks in the informal group Lower Heterobranchia.
Murchisonellidae is a taxonomic family of sea snails, marine opisthobranch gastropod mollusks in the superfamily Murchisonelloidea.
Buccinum pulchellum is a species of sea snail, a marine gastropod mollusk in the family Buccinidae, the true whelks.
Colloniidae is a family of small sea snails with calcareous opercula, marine gastropod mollusks in the clade Vetigastropoda.
Skenea is a genus of small to minute sea snails, marine gastropod mollusks in the family Skeneidae.
The Skeneidae are a speciose family of minute to small marine gastropod molluscs in the superfamily Trochoidea.
Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.
Ammonicera is a genus of minute sea snails, marine gastropod molluscs or micromollusks in the family Omalogyridae.
