''Raphitoma perinsignis'' 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

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

.MolluscaBase (2019). MolluscaBase. Raphitoma perinsignis (E. A. Smith, 1884). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=1253741 on 2019-12-18

Description

The shell reaches a length of 7⅔ mm and a diameter of 3 mm. The ovate-fusiform shell is slightly pink with a reddish line around 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 ...

. The shell contains eight

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 three smooth, convex whorls in the

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 ...

. The subsequent whorls are convex and somewhat shouldered above the middle. They are covered with 10-12 narrow ribs. Towards the outer lip the ribs gradually become more remote from each other. The raised lines of growth are conspicuous and cross the five spiral lirations (16-20 on the body whorl), which are thus made minutely subgranulous. The aperture measures about half the length of the shell. The outer lip is incrassate and slightly sinuate above. The short

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 ...

is narrow.Smith E.A. (1884). Diagnoses of new species of Pleurotomidae in the British Museum. Annals and Magazine of Natural History. ser. 5, 14: 317-329
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Distribution

This marine species occurs off

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

References

External links

* {{DEFAULTSORT:Raphitoma Perinsignis perinsignis Gastropods described in 1884