Diplommatina sp.

Material examined.

Specimens from limestone cliff near Tam Tarn Kaison Cave, Viengxay District, Houaphanh Province (Fig. 14F).

Remarks.

These specimens differ from Diplommatina bifissurata in having less whorls (5 or 6), a circular aperture without anterior canal and protrusion, and with a strong columella tooth, while the latter species has 8 whorls, an anterior canal well developed resulting in a short protrusion on apertural lip, and with a small columellar tooth.