The genus Haplocochlias (Gastropoda, Skeneidae)

The known species of the genus Haplocochlias Carpenter, 1864, currently included in the family Skeneidae, are studied. We have included a total of 29 species, of which 17 were previously known, 11 are described as new species, and one more is kept without a specific name. Each species is figured with scanning electron micrographs, and its variability discussed, when possible. New information on habitat, distribution, and bathymetric range of some species is provided. Fossarus (Gottoina) compacta Dall, 1889, Parviturbo calidimaris Pilsbry & McGinty, 1945, Liotia erici Strong & Hertlein, 1939, Homalopoma concepcionensis Lowe, 1935, Parviturbo francesae Pilsbry & McGinty, 1945, Cyclostrema turbinum Dall, 1889 and Fossarus (Gottoina) bella Dall, 1889 are here transferred to the genus Haplocochlias. The alleged synonymy of Haplocochlias onaneyi with Haplocochlias williami is rebutted. A lectotype is designated for Fossarus (Gottoina) compacta Dall, 1889. In an appendix, fossil species and other taxa (Gottoina and Lophocochlias) related to or resembling Haplocochlias are commented on, and their type species illustrated.