''Caseolus commixtus'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of small air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

in the family

Geomitridae Geomitridae is a taxonomic family of small to medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea Helicoidea is a Taxonomy (biology), taxonomic Taxonomic rank, superfamily of air-b ...

. Although the

Fauna Europaea Fauna Europaea is a database of the scientific names and distribution of all living multicellular European land and fresh-water animals. It serves as a standard taxonomic source for animal taxonomy within the Pan-European Species directories Infr ...

spells this species name as shown here, with a -us ending, in many other sources, including the International Wildlife Law listing the name is spelled "Caseolus commixta". It is assumed these usages are in error, firstly because the Latin word "caseolus" is masculine, and also for reasons of consistency, because

Richard Thomas Lowe Richard Thomas Lowe (1802–1874) was an English botanist, ichthyologist, malacologist, and clergyman. In 1825 he graduated from Christ's College, Cambridge, and in the same year he took holy orders. In 1832 he became a clergyman in the Madeira ...

has named at least five other species in the genus ''

Caseolus ''Caseolus'' is a genus of land snails in the family Geomitridae.MolluscaBase eds. (2021). MolluscaBase. Caseolus R. T. Lowe, 1852. Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=996327 o ...

'' using masculine adjectival names.

Distribution

This species of land snail occurs in

Porto Santo Island Porto Santo Island () is a Portuguese island and municipality northeast of Madeira Island in the North Atlantic Ocean; it is the northernmost and easternmost island of the archipelago of Madeira, located in the Atlantic Ocean west of Europe a ...

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

, Portugal. It is mentioned in Annexes II and IV of

Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The ...

References

commixtus Molluscs of Madeira Endemic fauna of Madeira Taxa named by Richard Thomas Lowe Gastropods described in 1852 Taxonomy articles created by Polbot Habitats Directive species {{Geomitridae-stub