''Filodrillia columnaria'' 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

Borsoniidae Borsoniidae is a monophyletic family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet, P. (2011). Borsoniidae. Accessed through: World Register of Marine Species at http://www.marinespecies.o ...

.WoRMS (2015). Filodrillia columnaria Hedley, 1922. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=433806 on 2016-03-06

Description

(Original description) The shell has a slender elongate-fusiform shape. Its colour is buff, with a pale peripheral zone underlined by an orange band. It contains seven and a half

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, of which two constitute 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 ...

, angled at the shoulder, flattened above and rounded beneath, excavate at the base. The sculpture :—No radials occur. The fasciole area is traversed by three or four fine close threads. The rest of the shell carries stronger cords, uniform in size and evenly spaced. Of these there are seven on the penultimate and twenty-two 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 ...

. The aperture is open, right insertion ascending above the plane of the suture. A slight

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 ...

can be seen behind the aperture. The outer edge of the expanded lip is denticulate by the spiral sculpture. The inner lip shows a thin sheet of callus. The sinus is deep, spout shaped. 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 open. Hedley, Charles (1920), A revision of the Australian Turridae; Records of the Australian Museum, vol. XIII nr. 6, Sydney
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Distribution

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

References

* May, W.L. 1923. ''An Illustrated Index of Tasmanian Shells: with 47 plates and 1052 species''. Hobart : Government Printer 100 pp. {{Taxonbar, from=Q10282338 columnaria Gastropods of Australia Gastropods described in 1922