''Caseolus commixtus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small air-breathing land snails,

terrestrial Terrestrial refers to things related to land or the planet Earth. 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 or near the ground, as opposed to ...

pulmonate gastropod mollusks in the family

Geomitridae Geomitridae is a Taxonomy (biology), taxonomic Family (biology), family of small to medium-sized air-breathing land snails, Terrestrial molluscs, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.MolluscaBase eds. (2021). M ...

. Although the

Fauna Europaea Fauna Europaea is a database of the scientific names and distribution of all living multicellular Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight o ...

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 scientist, a botanist, ichthyologist, malacologist, and a 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 i ...

has named at least five other species in the genus '' Caseolus'' using masculine adjectival names.

Distribution

This species of land snail occurs in

Porto Santo Island Porto Santo Island () is a Portuguese island 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 and Africa. The munic ...

, Madeira, 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 E ...

References

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