The operculum is a corneous or calcareous anatomical structure like a trapdoor that exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc.
Cochlodina laminata is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.
Clausiliidae, also known by the common name door snails, is a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks.
Neniatlanta pauli is a species of small, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium, a sort of sliding door.
Muticaria is a genus of small, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails, all of which have a clausilium.
Megalophaedusa spelaeonis, in Japanese: Kazaanagiseru, is a species of small, air-breathing land snail, terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.
Trichotoxon martensi is a species of air-breathing land snail or semislugs, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. This species is endemic to Tanzania.
Pontophaedusa funiculum is a species of land snail, a gastropod in the family Clausiliidae, the door snails within the subfamily Serrulininae. All door snails have a clausilium with which they can close the shell aperture.
The Achatinoidea are a superfamily of air-breathing land snails and slugs, terrestrial gastropod mollusks in the informal group Sigmurethra.
The Clausilioidea are a superfamily of air-breathing land snails and slugs, terrestrial gastropod mollusks in the informal group Sigmurethra.
Ruthenica is a genus of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the subfamily Clausiliinae of the family Clausiliidae, the door snails, all of which have a clausilium.
Albinaria latelamellaris is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails.
Megalophaedusa is a genus of medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails, all of which have a clausilium.
Conus martensi is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies.
Parmarion martensi is a species of air-breathing land semislug, a terrestrial pulmonate gastropod mollusk in the family Ariophantidae.
Serrulina serrulata is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.
Bathyptychia is a genus of medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails, all of which have a clausilium.
