Revision of the Genus Triviella Jousseaume, 1884 (Mollusca, Gastropoda)

All known fossil and Recent species of the endemic South African genus Triviella Jousseaume, 1884 are critically revised. The type material of many species is presented on photos for the first time, and many of the often short original descriptions were emendated when necessary. All available information are summarized and aspects of the zoogeography are explained. Five new species are described as Triviella lorenzi n. sp., Triviella chiapponii n. sp., Triviella montorum n. sp., Triviella carptima n. sp., and Triviella martybealsi n. sp.