''Mitromorpha paula'' is a species of

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

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 ...

Mitromorphidae Mitromorphidae is a monophyletic family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet, P. (2011). Mitromorphidae Casey, 1904. In: MolluscaBase (2018). Accessed through: World Register of Marin ...

Description

The length of the shell attains 3.8 mm, its diameter 1.5 mm. (Original description) The minute, solid shell consists of 4½

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, including a blunt

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

of 2 whorls,. The whorls of the protoconch are convex and apparently smooth, but microscopically granular, separated by a linear suture. It ends abruptly, and from within it issue the spirals of the first spire-whorls. Perfect specimens show the granules in very close-set spiral rows. The spire whorls are slightly convex, with eight spiral lirae. The sutures are simple. The

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 ...

is arge, tapering anteriorly. 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 elongate-oval and rather widely open in front. The outer lip is simple, crenulated outside by the sculpture, slightly convex in profile, with a minute round, shallow sinus close to the suture. The inner lip is a complete narrow glaze. The sculpture shows twenty-three spiral lirae, flat-topped, half as wide as the interspaces, axially faintly incised. The colour is cinnamon-brown, lighter in a band on the prominence of the whorls.Verco, J.C. 1909. ''Notes on South Australian marine Mollusca with descriptions of new species. Part XII.'' Transactions of the Royal Society of South Australia 33: 293–342
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Distribution

This marine species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Australia and occurs off

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

References

Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213–359, pls 42–56

External links

* {{DEFAULTSORT:Mitromorpha Paula paula Gastropods described in 1909 Gastropods of Australia