Stylommatophora is an order of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon includes most land snails and slugs. Stylommatophorans lack an operculum, but some close their shell apertures with temporary "operculum" (epiphragm) made of calcified mucus. They have two pairs of retractile tentacles, the upper pair of which bears eyes on the tentacle tips. All stylommatophorans are hermaphrodites.
Limacidae, also known by their common name the keelback slugs, are a taxonomic family of medium-sized to very large, air-breathing land slugs, terrestrial pulmonate gastropod molluscs in the superfamily Limacoidea.
Parmacellidae is a family of air-breathing land slugs, terrestrial pulmonate gastropod mollusks within the superfamily Parmacelloidea.
Hygromiidae is a taxonomic family of small to medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.
Oxychilidae is a taxonomic family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Gastrodontoidea.
Milacidae is a family of air-breathing, keeled, land slugs. These are shell-less terrestrial gastropod mollusks in the superfamily Parmacelloidea.
Enidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks.
Pleurodontidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.
Elonidae is a family of air-breathing land snails, terrestrial pulmonate gastropods mollusks in the superfamily Helicoidea.
Vitrinidae is a family of small, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Limacoidea.
Ariophantidae is a taxonomic family of air-breathing land snails and semi-slugs, terrestrial pulmonate gastropod mollusks in the superfamily Helicarionoidea.
Urocyclidae is a family of air-breathing land snails, semi-slugs and land slugs, terrestrial pulmonate gastropod mollusks in the superfamily Helicarionoidea.
Gastrodontidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Gastrodontoidea.
Staffordiidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Trochomorphoidea.
Oleacinidae is a taxonomic family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the clade Eupulmonata.
Spiraxidae is a family of predatory air-breathing land snails, terrestrial pulmonate gastropods in the superfamily Testacelloidea.
Aillyidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the informal group Sigmurethra.
Sigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This is an informal group which includes most land snails and slugs.
The Limacoidei is a taxonomic infraorder of air-breathing land snails, semislugs and slugs, terrestrial pulmonate gastropod molluscs in the suborder Helicina
