''Microdrillia commentica'' 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 Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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). 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). Whorls in nature File:Photograph and axial plane floral ...

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, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

. 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 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 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 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 is ...

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 Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and occurs off

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

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