Rivularia Heude, 1890
Examined species: Rivularia auriculata (Martens, 1875)
(Figs 2G, 3G, 6 G).
Remarks: The semi-elliptical operculum of Rivularia is most similar to that of Tulotoma . However, the operculum of Rivularia has no obvious marginal region; there is, however, a smooth, large scar region.