''Nepotilla microscopica'' 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 1.3 mm, its diameter 0.7 mm. (Original description) The very minute, yellowish shell contains 3½

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 flo ...

s, including a 1½ whorled

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 ...

, which is large, rounded, and spirally lirate. The two adult whorls are strongly angled at the periphery, from whence to the suture they are flat or concave. The sculpture consists of sharp, narrow, axial ribs, about twelve 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 ...

, which extend from suture to suture, and pass into the aperture. They are widely separated, the interspaces being crossed by a few very faint spiral lirae. The aperture is rather expanded. 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 very short. The columella is excavate. The outer lip is strongly varixed. The sinus at the suture is deep and open and bordered by a varix.

Distribution

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

References

* Gatliff, J.H. & Gabriel, C.J. 1916. ''Additions to the alterations in the Catalogue of the Marine Shells of Victoria.'' Proceedings of the Royal Society of Victoria 29(1): 106-113 * 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

Atlas of Living Australia: ''Nepotilla aculeata''
*
Grove, S.J. (2018). A Guide to the Seashells and other Marine Molluscs of Tasmania: ''Nepotilla microscopica''
{{Taxonbar, from=Q3715277 microscopica Gastropods described in 1916 Gastropods of Australia