Bellamyinae Rohrbach, 1937

Subfamily Bellamyinae Rohrbach, 1937 View in CoL

Identification key to genera Bakyietaia gen. nov., Taia View in CoL , Angulyagra View in CoL *, Sinotaia View in CoL , Anulotaia View in CoL , Filopaludina View in CoL

1. Columellar lip recurved, forming callus covering umbilicus completely or partially ...................... 2

– Columellar lip simple, not recurved, umbilicus open ....................................................................... 3

2. Primary keels smooth, operculum with small nuclear region (around 1/4 to 1/5 of inner opercular region) with shiny grains or veins ........................ Bakyietaia Zhang, Yen & von Rintelen gen. nov.

– Keel absent, or with obvious spines or nodules on primary keel, inner opercular region completely or partly covered by a rough sandpaper-like layer .......................................... Taia Annandale, 1918 View in CoL

3. Umbilicus widely open, with a strong keel around, primary keels strong ....................................... 4

– Umbilicus narrowly open, without obvious keel around, primary keel weak or absent .................. 5

4. Shell large, ~ 35 mm in height, thin and fragile, operculum with growth lamellae on exterior surface and radial striae on interior surface, with large smooth nuclear region (around 1/3 of inner opercular region) ............................................................................................................ Angulyagra Rao, 1931 View in CoL

– Shell small to medium, always 20 to 30 mm in height, thick and solid, operculum with small nuclear region (around 1/5 of inner opercular region) with shiny grains or veins ..... Anulotaia Brandt, 1968 View in CoL

5. Operculum with small nuclear region with shiny grains or veins ...................... Sinotaia Haas, 1939 View in CoL

– Operculum with inner opercular region (including nuclear region) completely or partly covered by a rough sandpaper-like layer ...................................................................... Filopaludina Habe, 1964 View in CoL

*Only characters of the type species of Angulyagra View in CoL have been included when building the key.