''Ancistrobasis monodon'' 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 extremely small deep water sea snail, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 ...

Seguenziidae Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Bouchet, P. (2012). Seguenziidae. Accessed through ...

.WoRMS (2013). ''Ancistrobasis monodon'' (Schepman, 1908). Retrieved through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific speciali ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=492314 on 2013-06-10

Description

(Original description by Schepman) The height of the shell attains 4¾ mm. The yellowish-white, perforate, conical shell has slightly convex sides, The six

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 are slightly convex. The nucleus is smooth. The other whorls are

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 ...

d by numerous concentric ribs and spiral lirae, about 9 in number on the penultimate whorl, producing a cancellated appearance. Where they cross, they form small tubercles. The body whorl is angular at the periphery. The flat base of the shell is sculptured by 12 spiral lirae and by radiating riblets, which make the inner 9 lirae beaded, the outer ones being crenulated. The small

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy * ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus urbis Romae The ...

is funnel-shaped, pervious, with smooth walls. 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 rhombic. Its upper margin is nearly straight, thin, thickened interiorly by a broad, white rib, with a few short plicae. The basal margin is slightly convex, with a few inconspicuous plicae and a strong tooth near the

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 ...

, forming the end of an internal rib, winding round the columella. The columella is nearly straight. Its upper part is thickened, covering part of the umbilicus. The parietal wall has a thin layer of enamel.Schepman 1908-1913, The Prosobranchia of the Siboga Expedition; Leyden,E. J. Brill,1908-13
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Distribution

This marine species occurs off the Sulu Archipelago, Philippines, and off New Caledonia.

References

External links

To Encyclopedia of Life

To World Register of Marine Species

Intergovernmental Oceanographic Commission (IOC) of UNESCO. The Ocean Biogeographic Information System (OBIS)
{{Taxonbar, from=Q13371531 monodon Gastropods described in 1908