Trochomorpha (?) sp. 1

Material examined.

Specimens from Tam Nang Rod Cave, Na-dan village, Yommalath District, Khammouan Province (Fig. 33E).

Remarks.

These specimens differ from all other known species in Indochina by having a trochiform with a dome-shaped shell with the upper periphery dome-shaped and the lower periphery flattened; the shell is thickened and relatively large; last whorl with a sharp peripheral keel; upper periphery with irregular growth lines and brownish subsutural band; aperture angulated, lip simple and slightly thickened; umbilicus widely open and deep.

The generic assignment of this species in Trochomorpha s.l. is still provisional, and additional anatomical studies are necessary to confirm the systematic position of this species.