Sinotaia Haas, 1939

Examined species: Sinotaia angularis (Müller, 1774) (Figs 4C, 5C, 7C).

Remarks: Apart from Anularya, Sinotaia can be distinguished from other genera with a concentric inverted-comma-shaped operculum by the following combination of characters: a thick, smooth, shiny, non-transparent and small nuclear region and a thick enamel region.