Trochomorpha (?) sp. 2

Material examined.

Specimens from Tam Xang Cave, Thakhek District, Khammouan Province (Fig. 33F).

Remarks.

These specimens obviously differ from Trochomorpha paviei by having a trochiform shell with the upper periphery dome-shaped and the lower periphery flattened; shell thickened, with monochrome dark brown colour; shell surface with thin transverse ridges; apertural lip slightly thickened; umbilicus open and deep. In contrast, Trochomorpha paviei has a trochiform shell with the upper periphery depressed, dome-shaped and the lower periphery convex; shell thin, translucent with monochrome brownish colour; apertural lip simple; 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.