''Filodrillia haswelli'' 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 haswelli (Hedley, 1907). In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=433809 on 2016-03-08

Description

The length of the shell attains 5.5 mm, its width 1 mm. (Original description) The small shell has a fusiform shape. It is blunt at each end, rather thin, scarcely opaque. It consists of 5½

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 first two constituting a glassy dome-shaped

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 rest are rather inflated, constricted at the sutures and excavate at the base. Its colour is chalk white, rather glossy when fresh. The sculpture shows fine spiral threads, one more prominent than the rest defines a slight angle on the shoulder. 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 ...

there are about four above and twenty below the angle. The spirals are crossed by arcuate growth lines. The aperture is slightly ascending, narrow above, rounded within a deep notch, fortified without by a heavy

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 ...

. A thin callus is spread on the inner lip. 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.Hedley, C. 1907. ''The results of deep sea investigation in the Tasman Sea. Mollusca from eighty fathoms off Narrabeen''; Records of the Australian Museum v. 6 (1905-1907)
/ref>

Distribution

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

References

* Hedley, C. 1922. ''A revision of the Australian Turridae''. Records of the Australian Museum 13(6): 213-359, pls 42-56 * May, W.L. 1923. ''An Illustrated Index of Tasmanian Shells: with 47 plates and 1052 species.'' Hobart : Government Printer 100 pp. * Laseron, C. 1954. ''Revision of the New South Wales Turridae (Mollusca)''. Australian Zoological Handbook. Sydney : Royal Zoological Society of New South Wales 1-56, pls 1-12. {{Taxonbar, from=Q10282342 haswelli Gastropods of Australia Gastropods described in 1907