''Basilissopsis'' 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 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 ...

. In 1897 Dautzenberg and

Fischer Fischer is a German occupational surname, meaning fisherman. The name Fischer is the fourth most common German surname. The English version is Fisher. People with the surname A * Abraham Fischer (1850–1913) South African public official * ...

created this new genus for their specimen of ''Basilissopsis watsoni'', based on the shell characteristics of discolored specimens that were non-nacreous and lacked labral sinuses. This was however contradicted later by the discovery of other species in this genus that possess nacre and labral sinuses. This puts this genus in the family

Description

Nothing is known of the anatomy of the soft body in these species. The conical shell has peripheral carina and collabral axial riblets. 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 contain midwhorl angulation but spiral lirae are absent. The U-shaped posterior sinus is shallow. There is no anterolateral sinus. A basal sinus is present. A columellar sinus is lacking. 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 ...

has a rhomboidal shape. A columellar tooth is lacking. The

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 ...

contains a septum. The shell has no microsculpture. There are no data about the

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 ...

Species

Species within the genus ''Basilissopsis'' include: * '' Basilissopsis athenae'' Hoffman, Gofas & Freiwald, 2020 *'' Basilissopsis bassa'' Lima, Christoffersen & Villacampa, 2014 *'' Basilissopsis charcoti'' Marshall, 1991 *'' Basilissopsis hakuhoae'' Kurihara & Ohta, 2008 *'' Basilissopsis oxytropis'' (

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) *'' Basilissopsis regina'' (Marshall, 1983) *''

Basilissopsis rhyssa ''Basilissopsis rhyssa'' is a species of sea snail, a marine gastropod mollusc in the family Seguenziidae. Description The height of the shell attains 2.1 mm. The shell is very similar to the shell of '' Basilissopsis watsoni'' Dautzenb ...

'' (

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 ...

, 1927) * '' Basilissopsis vanheugteni'' Hoffman & Freiwald, 2017 *''

Basilissopsis watsoni ''Basilissopsis watsoni'' is a species of sea snail in the family Seguenziidae. Description The height of the nacreous shell attains 2 mm. The shell has labral sinuses. Distribution This species occurs in the Atlantic Ocean off the Azore ...

'' Dautzenberg &

, 1897

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=Q4867462 Seguenziidae Gastropod genera Taxa named by Paul Henri Fischer