''Williamia radiata nutata'' is a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of small

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 ...

or saltwater

limpet Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended indep ...

with a lung, 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 * ...

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 includ ...

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

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Siphonariidae Siphonariidae, also known as false limpets, are a taxonomic family of small to medium-sized air-breathing sea snails, marine and brackish water pulmonate gastropod molluscs. __TOC__ Shell description Empty siphonariid limpet shells can b ...

, the marine pulmonate limpets.Bouchet, P. (2011). Williamia radiata nutata (Hedley, 1908). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=559220 on 2012-04-11

References

* Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979 * Marshall B.A. (1981) ''The genus Williamia in the western Pacific (Mollusca: Siphonariidae).'' New Zealand Journal of Zoology 8: 487-492. {{Taxonbar, from=Q8020943 Siphonariidae