''Ancistrobasis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of sea snails, and 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 ...

s 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 ...

Dall Dall may refer to: People * Anders Bendssøn Dall (died 1607), Danish Lutheran bishop * Bobby Dall (born 1963), American musician * Caroline Healey Dall (1822–1912), American feminist writer *Clarrie Dall (1887–1953), Australian footballer * C ...

(1889) regarded (with some doubt) ''Ancistrobasis'' as a section of the closely related genus ''

Basilissa ''Basileus'' ( el, ) is a Greek term and title that has signified various types of monarchs in history. In the English-speaking world it is perhaps most widely understood to mean "monarch", referring to either a "king" or an "emperor" and a ...

'' ''Watson, 1879''.

Description

This genus contains the dentate forms of species formerly included in the genus ''

''.

Shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

: The conical shell shows peripheral carina and collabral axial riblets. The midwhorl angulation and the spiral lirae are present on all

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 posterior sinus depth is shallow. The posterior sinus has a U-shape. The anterolateral sinus is absent. The rhomboidal

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 ...

contains a basal and columellar sinus. The umbilical septum (a transverse plate secreted with early formed whorls of the shell) is absent. The shell contains pustulate microsculpture.

Radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

: The rachidian tooth is broader than high with lateral wings prominent. The lateral tooth cusp is broad. The radula contains less than 10 marginal tooth pairs.

Species

Species within the genus ''Ancistrobasis'' include: *''

Ancistrobasis adonis ''Ancistrobasis adonis'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily ...

'' Marshall, 1991 *''

Ancistrobasis boucheti ''Ancistrobasis boucheti'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis boucheti'' Marshall, 1991. Retrieved through: World Register of Marine Species ...

'' Marshall, 1991 *''

Ancistrobasis caledonica ''Ancistrobasis caledonica'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis caledonica'' Marshall, 1991. Retrieved through: World Register of Marine Spe ...

'' Marshall, 1991 *'' Ancistrobasis compsa'' Melvill, 1904 *''

Ancistrobasis depressa ''Ancistrobasis depressa'' is a species of sea snail, a marine gastropod mollusk in the family Seguenziidae. Description (description by G.W. Tryon) The height of the shell attains 5 mm. The shell figured differs from ''Basillisa costula ...

'' (

, 1889) *''

Ancistrobasis dilecta ''Ancistrobasis dilecta'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis dilecta'' Marshall, 1983. Retrieved through: World Register of Marine Species a ...

'' Marshall, 1983 *''

Ancistrobasis largoi ''Ancistrobasis largoi'' is a species of sea snail, a marine gastropod mollusk in the family Seguenziidae. Description The size of the shell varies between 3 mm and 7 mm. Distribution This marine species occurs off the Philippines ...

'' Poppe, Tagaro & Dekker, 2006 *''

Ancistrobasis monodon ''Ancistrobasis monodon'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis monodon'' (Schepman, 1908). Retrieved through: World Register of Marine Species ...

'' (

Schepman Mattheus Marinus Schepman (17 August 1847 – 19 November 1919) was a Dutch malacologist. He was one of the foremost collectors of mollusc shells in the Netherlands, and was also high on the overall list of European collectors. Dutch collecto ...

, 1908) *''

Ancistrobasis reticulata ''Ancistrobasis reticulata'' is a species of sea snail, a marine gastropod mollusk in the family Seguenziidae. Distribution This species occurs in the Gulf of Mexico, off Brazil Brazil ( pt, Brasil; ), officially the Federative Republi ...

'' (

Philippi Philippi (; grc-gre, Φίλιπποι, ''Philippoi'') was a major Greek city northwest of the nearby island, Thasos. Its original name was Crenides ( grc-gre, Κρηνῖδες, ''Krenides'' "Fountains") after its establishment by Thasian col ...

, 1844) *''

Ancistrobasis scitula ''Ancistrobasis scitula'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis scitula'' Marshall, 1991. Retrieved through: World Register of Marine Species ...

'' Marshall, 1991 *''

Ancistrobasis tiara ''Ancistrobasis tiara'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis tiara'' Marshall, 1991. Retrieved through: World Register of Marine Species at ht ...

'' Marshall, 1991 *''

Ancistrobasis zumbii ''Ancistrobasis zumbii'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.Bouchet, P. (2013). ''Ancistrobasis zumbii'' Lima, Christoffersen & Barros, 2013. Retrieved through: World Reg ...

'' Lima, Christoffersen & Barros, 2013 ;Species brought into synonymy: *''Ancistrobasis costulata'' (

Watson Watson may refer to: Companies * Actavis, a pharmaceutical company formerly known as Watson Pharmaceuticals * A.S. Watson Group, retail division of Hutchison Whampoa * Thomas J. Watson Research Center, IBM research center * Watson Systems, maker ...

, 1879): synonym of ''

'' (

, 1844) *''Ancistrobasis regina'' Marshall, 1983: synonym of ''

Basilissopsis regina ''Basilissopsis regina'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Basilissopsis regina'' (Marshall, 1983). Retrieved through: World Register of Marine Species a ...

'' (Marshall, 1983)

References

* Marshall B.A. (1991). ''Mollusca Gastropoda : Seguenziidae from New Caledonia and the Loyalty Islands. In A. Crosnier & P. Bouchet (Eds) Résultats des campagnes Musorstom'', vol. 7. Mémoires du Muséum National d'Histoire Naturelle, A, 150:41-109 {{Taxonbar, from=Q3167941 Seguenziidae Gastropod genera