''Exomilus edychrous'' 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 ...

.Bouchet, P. (2015). Exomilus edychrous (Hervier, 1897). In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://marinespecies.org/aphia.php/aphia.php?p=taxdetails&id=714108 on 2016-09-20

Description

The length of the shell varies between 3 mm and 4.1 mm; its diameter 1.1 mm. (Original description) The small, solid, shell is subcylindrical. The shoulder is sloping, the body perpendicular, the base excavate, sharply angled at base and shoulder. The colour of all specimens seen are faded, but appear to have been buff, the protoconch and spots on the lower whorls darker, the basal keel white. The teleoconch contains three

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. 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 ...

consists of 3½ whorls, of which the first is turbinate, slightly tilted and engraved with microscopic spirally punctured lines, followed by two transitional whorls keeled at periphery, and ornamented by fine close obliquely radiating riblets. The adult sculpture : on 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 ...

, fifteen spiral cords, of which the third and eighth are prominent, expressing the angle above and below the barrel of the whorl, the basal cords are broken into beads. The penultimate whorl shows six, and the antepenultimate with three spirals. Broader than the spirals are the perpendicular radials, fourteen on the body whorl, and proportionately fewer on the rest. Commencing at the suture and vanishing on the base, they raise tubercles at the intersection of the spirals. The resulting meshes enclose deep pits in which is a microscopic shagreen surface. The aperture is contracted, straight above, flexed below, fortified by a broad strong

varix A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins usua ...

, out of which a deeply notched subcircular

anal sulcus The anal sulcus, also called the anal sinus or anal canal, in Gastropods is a notch, a shelly tube at the top of the aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and fo ...

is excavated. The spiral sculpture traverses the varix. Within the outer lip are four tubercles. The inner lip is excavate. The

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 short and broad. Ch. Hedley (1909), Mollusca from the Hope Islands, north Queensland; Proceedings of the Linnean Society of New South Wales v. 34 p. 458

Distribution

This marine species has a wide distribution:

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, Queensland, Australia; off

Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island ...

and Southeast Africa

References

* Hervier, J 1897. ''Descriptions d'espèces nouvelles de Mollusques, provenant de l'Archipel de la Nouvelle-Calédonie (suite)''. Journal de Conchyliologie 44: 138-151 * Powell, A.W.B. 1966. ''The molluscan families Speightiidae and Turridae, an evaluation of the valid taxa, both Recent and fossil, with list of characteristic species.'' Bulletin of the Auckland Institute and Museum. Auckland, New Zealand 5: 1–184, pls 1–23 * Kilburn, R. N. 2009. G''enus Kermia (Mollusca: Gastropoda: Conoidea: Conidae: Raphitominae) in South African waters, with observations on the identities of related extralimital species.'' African Invertebrates 50(2): 217-236

External links

Fedosov A. E. & Puillandre N. (2012) ''Phylogeny and taxonomy of the Kermia–Pseudodaphnella (Mollusca: Gastropoda: Raphitomidae) genus complex: a remarkable radiation via diversification of larval development.'' Systematics and Biodiversity 10(4): 447-477
*
MNHN, Paris: ''Exomilus edychrous'' (syntype in the MNHN, Paris)
*
Moretzsohn, Fabio, and E. Alison Kay. "HAWAIIAN MARINE MOLLUSCS." (1995)
edychrous Gastropods described in 1909 {{Raphitomidae-stub