Hypselostoma khmerianum (Sutcharit & Panha, 2023) comb. nov.

Figs 186 G, 202, 223

Gyliotrachela khmeriana Sutcharit & Panha in Sutcharit et al. 2023: 1295–1299, fig. 4.

Type material examined.

Cambodia • holotype; CUMZ 14206 .

Additional material examined.

Thailand • 15 shells (4 adult, 1 of them broken); Sa Kaeo Province, Khlong Hat district, Tham Phet Pho Thong; 13°24.946'N, 102°19.691'E; 03 June 2023; A. Hunyadi leg.; coll. HA .

Type locality.

“ The limestone hills at Phnom Sampeov Mountain, Banan District, Battambang Province, Cambodia (13.026000°N, 103.101011°E) ”.

Differential diagnosis.

This species is not similar to any hitherto described congener due to the combination of conical shell, absence of spiral striation, all whorls keeled, strong but not numerous apertural barriers, and separated angular and parietal lamellae. The shell shape somehow resembles H. sculpturatum but it differs from it by its adnate last whorl, separated angular and parietal lamellae and not spirally striated teleoconch. Hypselostoma circumcarinatum sp. nov. has its whorls keeled, a merged angulo-parietal lamella and spirally striated whorls. It is different from H. chatnareeae by the separated angular and parietal lamellae, weaker keel, and the absence of a deep groove above the keel.

Distribution.

This species is known from the type locality in Cambodia and is now reported for the first time in Thailand (Sa Kaeo province).