''Mitromorpha multicostata'' 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 in the family

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 4.3 mm, its diameter 2 mm. (Original description) The solid, yellowish shell has an elongate oval shape. It contains 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). Whorls in nature File:Photograph and axial plane floral ...

s, including a pointed

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 two smooth whorls. The spire

s are convex. The suture is well impressed. The base of the shell is contracted. The aperture is elongate oval, not constricted into a

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

. The outer lip is simple and convex in outline. The columella is slightly curved. The shell shows numerous straight rounded axial ribs that extend across the whorls, and over about two-thirds of 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 ...

there are about 24 on the penultimate whorl. They are separated by deep grooves, which are narrower than the ribs. There is one distinct spiral groove or depression below the suture. Numerous faint spirals, which can scarcely be seen without a lens, cross the shell, and are most conspicuous in the grooves. They become much stronger on the base.May, W.L. 1910. ''New marine Mollusca.'' Proceedings of the Royal Society of Tasmania 48: 380–398

Distribution

This marine species is endemic to Australia and occurs off Tasmania.

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 Multicostata multicostata Gastropods described in 1911 Gastropods of Australia