''Diloma'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of medium-sized

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, marine

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 ...

mollusk 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 ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.Bouchet, P. (2010). Diloma Philippi, 1845. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=391149 on 2011-07-02 There is also a genus ''Diloma'', F.H.Wind & P.Cepek, 1979 a genus of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

in the class

Prymnesiophyceae Prymnesiophyceae is a haptophyte class. Although it was originally described by Casper in 1972, it did not receive a Latin diagnosis (a requirement for valid publication under the International Code of Botanical Nomenclature The ''Internat ...

Description

The solid shell is imperforate and depressed globose. It is slate-colored or black, sometimes (especially if worn) reddish or brownish. The conic

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is short. The

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

is acute, usually reddish. The sutures are linear. The five

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s are slightly convex, rapidly increasing and spirally obsoletely striate. The

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

is usually depressed or subconcave below the suture. The base of the shell is rounded, eroded and iridescent in front of the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

. The aperture is huge, oblique iridescent. The outer lip is rather thin, not black-margined within; but bordered by a brilliantly iridescent band; The

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

is concave, obsoletely subdentate below, very broad and flattened or excavated on the face. It is composed principally of an opaque white layer which also lines the base but does not extend to the edge of the lip. The length of the shell varies between 15 mm and 26 mm. Its diameter varies between 17 mm and 24 mm.

Distribution

This genus occurs in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, including

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, and other areas.

Species

Phylogram A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In o ...

of the species in the genus ''Diloma'': Other species in the genus not included in the phylogram include: * ''

Diloma durvillaea ''Diloma durvillaea'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Rosenberg, G.; Bouchet, P. (2012). ''Diloma durvillaea'' Spencer, Marshall & Waters, 2009. Accessed through: World Register of Ma ...

'' Spencer, Marshall & Waters, 2009Spencer H. G., Marshall B. A. & Waters J. M. (2009). "Systematics and phylogeny of a new cryptic species of ''Diloma'' Philippi (Mollusca: Gastropoda: Trochidae) from a novel habitat, the bull kelp holdfast communities of southern New Zealand". '' Invertebrate Systematics'' 23: 19-25.
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* ''

Diloma nanum ''Diloma nanum'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Bouchet, P. (2012). ''Diloma nanum'' Gould, 1861. Accessed through: World Register of Marine Species at http://www.marinespecies.org/ ...

'' Gould, 1861 Species brought into synonymy: * ''Diloma constellatum'' Souverbie, 1863: synonym of ''

Austrocochlea constellata ''Austrocochlea constellata'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Bouchet, P. (2012). ''Diloma constellata'' Souverbie, 1863. Accessed through: World Register of Marine Species at http:/ ...

'' (Souverbie, 1863) * ''Diloma coracina'' Suter, H., 1909: synonym of '' Diloma arida'' (Finlay, 1927) * ''Diloma gaimardi'' Hutton: synonym of ''

Diloma aethiops ''Diloma aethiops'', whose common names include scorched monodont, spotted black topshell, and in the Māori language pūpū, pūpū-mai, or māihi is a species of small sea snail, a marine gastropod mollusc in the family Trochidae, subfamily M ...

Gmelin Gmelin may refer to: * Karl Christian Gmelin, Carl Christian Gmelin (1762–1837), German botanist, author of ''Flora Badensis, Alsatica et confinium regionum cis- et transrhenania'' (1806) * Charles Gmelin (1872–1950), British Olympic athlete * ...

, 1791 * ''Diloma impervia'' (Menke, 1843): synonym of ''

Oxystele impervia ''Oxystele impervia'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Description The size of the shell varies between 12 mm and 18 mm. The imperforate, rather thin shell has a conoidal s ...

'' (Menke, 1843) * ''Diloma piperinum'' (

Philippi Philippi (; , ''Phílippoi'') was a major Greek city northwest of the nearby island, Thasos. Its original name was Crenides (, ''Krēnĩdes'' "Fountains") after its establishment by Thasian colonists in 360/359 BC. The city was renamed by Phili ...

, 1849): synonym of ''

Austrocochlea piperina ''Austrocochlea piperina'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Marshall, B. (2015). Austrocochlea piperina (Philippi, 1849). In: MolluscaBase (2015). Accessed through: World Register of M ...

'' (Philippi, 1849) * ''Diloma sinensis'' (Gmelin, 1791) :synonym of '' Oxystele sinensis'' (Gmelin, 1791) * ''Diloma suavis'' (Philippi, 1849): synonym of '' Pictodiloma suavis'' (Philippi, 1849) * ''Diloma tabularis'' (Krauss, 1848): synonym of '' Oxystele tabularis'' (Krauss, 1848) * ''Diloma tigrina'' (Anton, 1838): synonym of ''

Oxystele tigrina ''Oxystele tigrina'', common name the tiger top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Description The size of an adult shell varies between 25 mm and 43 mm. The more or l ...

'' (Anton, 1838) * ''Diloma variegata'' (Anton, 1838): synonym of '' Oxystele variegata'' (Anton, 1838) * ''Diloma novaezelandiae'' Anton, 1839: synonym of ''

Diloma subrostrata ''Diloma subrostratum'', common name the mudflat top shell, is a species of small sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Marshall, B.; Bouchet, P. (2016). Diloma subrostratum (Gray, 1835). In: MolluscaBase ...

'' (Gray in Yate, 1835) * ''Diloma (Chlorodiloma) millelineata'' (Bonnett, 1864): synonym of '' Chlorodiloma millelineata'' (Bonnett, 1864) * ''Diloma (Fractarmilla) lenior'' Finlay, H.J., 1927: synonym of ''

Diloma bicanaliculata ''Diloma bicanaliculatum'', common name the knobbed top shell, is a species of small sea snail, a marine gastropod mollusk, in the family Trochidae, the top snails. The size of the shell varies between 10 mm and 20 mm. Distribution Th ...

'' (Dunker, 1844)

References

* Williams S.T., Karube S. & Ozawa T. (2008) ''Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined''. Zoologica Scripta 37: 483–506

External links

* {{Taxonbar, from=Q3512321 Trochidae Taxa named by Rodolfo Amando Philippi Gastropod genera