''Microdrillia commentica'' is a species of

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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.org/ ...

.WoRMS (2015). Microdrillia commentica. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=434401 on 2016-03-15

Description

The height of the small shell attains 7 mm. (Original description) The small, solid shell has a narrowly fusiform shape. Its colour is uniform cream. The shell contains nine

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). In nature File:Photograph and axial plane floral diagra ...

s. The first three are small and smooth, the next ones with a dozen prominent curved radial ribs. On the following whorl, a keel arises from the base, reaches the periphery, and, as a conspicuous median keel, descends to the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

. The upper whorls have a second conspicuous spiral keel below the suture, between which and the peripheral keel lies the fasciole, a third and fainter keel runs below the median. On the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

, there are about a dozen spirals below the main keel. The fasciole is sculptured by transverse crescentic threads becoming weaker on the later whorls. Radial threads also appear over the whole shell. The aperture is narrow, notch deep, subsutural. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is simple, thin and projecting. 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 i ...

is broad and short. Hedley C. (1915), Studies on Australian Mollusca. Part XII; Proceedings of the Linnean Society of New South Wales v. 39
(described as ''Drillia commenticus'')

Distribution

This marine species is endemic to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and occurs off

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

References

* Hedley, C. 1922. ''A revision of the Australian Turridae''. Records of the Australian Museum 13(6): 213–359, pls 42–56

External links

Bouchet P., Kantor Yu.I., Sysoev A. & Puillandre N. (2011) A new operational classification of the Conoidea. Journal of Molluscan Studies 77: 273–308
* commentica Gastropods of Australia Gastropods described in 1915 Endemic fauna of Australia Fauna of Queensland {{Borsoniidae-stub