''Cyclostrema ocrinium'' 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 ...

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 ...

mollusk 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 e ...

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 ...

Liotiidae Liotiidae is a family of small sea snails, marine gastropod mollusks in the clade Vetigastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Gofas, S. (2013). Liotiidae Gray, 1850. Accessed through: World Register of ...

.Bouchet, P. (2012). ''Cyclostrema ocrinium'' Melvill & Standen, 1901. Accessed through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=701872 on 2012-12-03

Description

The height of the shell attains 2 mm, its diameter 3 mm. The delicate, white, umbilicated shell contains four

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). Whorls in nature File:Photograph and axial plane floral ...

s. it is destitute of spiral ribs. The longitudinal riblets are very close and fine, about 26 in number on the five-angled

body whorl The body whorl is part of the morphology of the 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. In gastropods In gastropods, the b ...

, that surround the umbilicus at the base being the strongest and most conspicuous. Regular rows of shining gemmae on the costulae at the point of the angular projections take the place of spiral lirae. The interstices are plain, vitreous white. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is circular. The peristome is continuous. The outer lip is crenulate. The columellar margin is not reflexed over the umbilicus, which is deep and conspicuous.Melvill & Standen (1901) Mollusks from the Persian Gulf and Arabian Sea; Proceedings of the Zoological Society of London. v. 2, 1901
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Distribution

This marine species occurs in the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...

and off

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...

References

* Trew, A., 1984. ''The Melvill-Tomlin Collection. Part 30. Trochacea''. Handlists of the Molluscan Collections in the Department of Zoology, National Museum of Wales

External links

World Register of Marine Species
ocrinium Gastropods described in 1901 {{liotiidae-stub