Genus Thamkhondonia gen. n.

Diagnosis.

The diagnostic features of the genus are the same as those of the type species, Thamkhondonia moureti sp. n. The elongated axially and radially sculptured shell with an ear-shaped aperture differs from that of any known genus of Pomatiopsidae from tributaries of the Mekong River. The shell shows some resemblance to those of species in the triculinid genus Paraprosothenia Annandale, 1919 and the marine genus Attenuata Hedley, 1918, but differs from both by the characteristic shell sculpture consisting of spiral cords and axial ribs.

Etymology .

Named after the type locality inside the Tham Khon Dôn Cave situated under the massif of Pha Kouankaohong near village Ban Na in Khammouane Province.