New species of Vitrinellidae (Gastropoda: Truncatelloidea) from the Indo-Pacific. The genus Circulus Jeffreys, 1865

New species belonging to the family Vitrinellidae, genus Circulus Jeffreys, 1865, from shallow and deep waters of the Indo-Pacific are described. All of them are compared with the previously known species, belonging to this
genus. Due to the great morphological diversity of the material studied and in the absence of sufficient anatomical and molecular studies that justify the description of new genera, we have placed all the species in the genus Circulus, grouping them by morphological affinities. Cyclostremiscus beauii (P. Fischer, 1857) is considered a junior synonymous of Cyclostrema
angulata A. Adams, 1850. Vitrinella sculptilis Garrett, 1873 and
Cyclostrema marchei Jousseaume, 1872 as well as Cyclostrema octolirata Carpenter, 1856 and Vitrinella liricincta Garrett, 1873 are considered not conspecific. Cyclostrema tornata A. Adams, 1864 is transferred to Tuberes Rubio & Rolán, 2017; Circlotoma callusa Laseron, 1958 and Cyclostrema pachyston Verco, 1907 are transferred to Solariorbis Conrad, 1865; and, finally, Circulus perlatus Pelseneer, 1903 is transferred to Orbitestella Iredale, 1917.