''Nepotilla bathentoma'' 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). . 3 ...

Description

The length of the shell attains 2.8 mm, its diameter 1.45 mm. (Original description) The small, white, thin shell consists of 5

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 the prominent conical

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 convex elate whorls, with exserted apex. The whorls of the spire have a corded obtuse angulation, with a slope from the upper suture, somewhat constricted towards the lower. 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 ...

shows a second angulation starting from the suture at the aperture. Below this the base is rapidly concavely contracted. The aperture is obliquely oval. 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. The outer lip is thin, simple and biangulate. There is a deep, narrow sinus at the suture with parallel margins. The outer lip is in profile slightly convex to the front angulation, then concave to the edge of the siphonal canal. The columella is very long, nearly straight. When looked at from the apex the shell is faintly polygonal, with ten angles in a spiral (in a cotype these are produced into transverse sharp tubercles). A single spiral runs between the angulation and the upper suture, and in the body whorl bounds the front of the posterior sinus. Another lies midway between the angulation and the lower suture. In the suture, the second angulation of the body whorl may appear as a sutural cord. This bounds the back of the posterior labral sinus. Concave forward axials run from the suture to the nearest spiral, then become straight and very oblique from this to the first angle, then vertical to the next angle, and are lost on the base. They do not cross the spirals or stand erect. 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

Distribution

This marine species is endemic to Australia and occurs off New South Wales, South Australia and Tasmania

References

* 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 * May, W.L. 1923. An illustrated index of Tasmanian shells: with 47 plates and 1052 species. Hobart : Government Printer 100 pp.* 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

External links

Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213-359, pls 42-56
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Mollucs of Tasmania: ''Nepotilla bathentoma''
{{DEFAULTSORT:Nepotilla Bathentoma bathentoma Gastropods described in 1909 Gastropods of Australia