Basilissopsis is a genus of sea snails in the family Seguenziidae.
In 1897 Dautzenberg and Fischer 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.Dautzenberg and H. Fischer. 1897. Campagnes scientifiques de S. A. Ie Prince Albert l de Monaco. Diagnoses d'especes nouvelles de gasteropodes. Bull. Soc. Zool. Fr. 22: 37–45. 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 Seguenziidae.
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 whorls 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 has a rhomboidal shape. A columellar tooth is lacking. The umbilicus contains a septum. The shell has no microsculpture. There are no data about the radula.
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, 1879) Basilissopsis regina (Marshall, 1983) Basilissopsis rhyssa (Dall, 1927) Basilissopsis vanheugteni Hoffman & Freiwald, 2017 Basilissopsis watsoni Dautzenberg & Fischer, 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.