''Semicassis undulata'' is a Mediterranean species of medium-sized

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Cassinae, the helmet snails and bonnet snails.

Taxonomy

This taxon was previously sometimes referred to at subspecies level as ''Semicassis granulata undulata'', but in 2019, the World Register of Marine Species lists this Mediterranean taxon as a separate species from '' Semicassis granulata'', which is a Western Atlantic taxon.Rosenberg, G. (2012). Semicassis granulata undulata (Gmelin, 1791). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=591482 on 2012-06-17

Distribution

This species occurs in the Mediterranean Sea and in the Atlantic Ocean off Northwest Africa and the

Macaronesian Islands Macaronesia (Portuguese: ''Macaronésia,'' Spanish: ''Macaronesia'') is a collection of four volcanic archipelagos in the North Atlantic, off the coasts of Africa and Europe. Each archipelago is made up of a number of Atlantic oceanic island ...

References

* Kreipl K. 1997. ''Recent Cassidae.'' Christa Hemmen, Wiesbaden, 151 p. page(s): 55 Cassidae Gastropods described in 1791 Taxa named by Johann Friedrich Gmelin {{Cassidae-stub