''Astralium provisorium'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of sea snail, a marine gastropod

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 es ...

in the

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

Turbinidae Turbinidae, the turban snails, are a family of small to large marine gastropod molluscs in the superfamily Trochoidea.Bouchet, P. (2014). Turbinidae Rafinesque, 1815. Accessed through: World Register of Marine Species at http://www.marinespec ...

, the turban snails.

Description

The length of the shell varies between . The imperforate shell has a conoidal shape with a flat base and contains about five

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. The three upper whorls are three eroded and nearly covered by incrustations, but apparently rather smooth. The penultimate whorl shows oblique wrinkles, crossed by 3 or 4 spiral rows of square granules. Towards the body whorl, about eight irregular tubercles make their appearance. These are also covered by the wrinkles and granules, below the tubercles. The last row of granules runs uninterrupted and is succeeded towards the keel by short plications, which have about the same direction as the wrinkles. Moreover, the upper surface of this whorl is covered by spiral lirae, only visible under a lens. The whorls are inflated at their upper part, concave at the lower portion and are then again broader, thus covering the sutures and even part of the subsequent whorls. The keel is very sharp, with short spines, about 1 to 7 in number, if seen from the base. These spines are compressed, and open in front. The base of the shell is flat, with 8 irregular lirae, with compressed scales. Towards the keel, a few undulating spiral striae appear. This

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

is crossed by small radiating riblets. 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 ...

is rhomboidal, very oblique, with sharp edges and an internal nacreous layer, at some distance from the margin, with 10 lirae near this margin, and a groove corresponding to the keel. The basal margin is smooth. The thick

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...

is emarginate, thickened towards the base and forming a toothlike angle, at the junction with the basal margin. The colour of the shell is yellowish-olive. The top whorls, a zone at the base of the whorls, especially of the last oneare rose-coloured. The base is tinted with the same colour.Schepman M.M. (1909), The prosobranchia of the Siboga Expedition
/ref>

Distribution

This marine species occurs off the Sulu Archipelago, southwestern Philippines

References

Schepman 1908–1913, The Prosobranchia of the Siboga Expedition; Leyden,E. J. Brill, 1908–13
* Kreipl K. & Dekker H. 2003. ''A new species of Astralium Link, 1807 (Mollusca, Gastropoda, Turbinidae) from the Philippine Islands''. Novapex 4(1): 25–27 * Alf A. & Kreipl K. (2011) ''The family Turbinidae. Subfamilies Turbininae Rafinesque, 1815 and Prisogasterinae Hickman & McLean, 1990''. In: G.T. Poppe & K. Groh (eds), A Conchological Iconography. Hackenheim: Conchbooks. pp. 1–82, pls 104–245.

External links

* {{DEFAULTSORT:Astralium Provisorium provisorium Gastropods described in 1903