Hypselostoma cambodjense Benthem Jutting, 1962

Sutcharit, Chirasak, Thach, Phanara, Chhuoy, Samol, Ngor, Peng Bun, Jeratthitikul, Ekgachai, Siriwut, Warut, Srisonchai, Ruttapon, Ng, Ting Hui, Pholyotha, Arthit, Jirapatrasilp, Parin & Panha, Somsak, 2020, Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda), ZooKeys 948, pp. 1-46 : 1

Hypselostoma cambodjense Benthem Jutting, 1962 Figs 3H , 8A-C

Hypselostoma cambodjense Benthem Jutting, 1962: 3-5, fig. 1. Type locality: Phnom Can Long, à 6 km au Sud de Tuk Méas, Cambodge. Vermeulen et al., 2019b: 33.

Material examined.

Locality no. 11: CUMZ-CM004 (77 shells; Fig. 8B ). Locality no. 12: CUMZ-CM073 (63 shells). Locality no. 9: CUMZ-CM087 (122 shells; Figs 3H , 8A ). Locality no. 17: CUMZ-CM138 (40 shells; Fig. 8C ). The snails were found to live on limestone wall syntopically with Georissa spp.

Distribution.

Kampot Province, Cambodia and Ha Tien Town area, Kien Giang Province, Vietnam ( Vermeulen et al. 2019b).

Remarks.

This species was originally described from limestone hills near "Tuk Méas”, probably in Banteay Meas area. The specimens collected from locality no. 9 are thus considered as topotypic specimens. These specimens agree well with the illustration in van Benthem Jutting (1962: fig. 1).

Hypselostoma cambodjense tends to be abundant and widely distributed in several karstic hills in southern Cambodia and Vietnam (see Vermeulen et al. 2019b). The populations from the localities no. 11 (Fig. 8B ) and 17 (Fig. 8C ) differ from the topotypic specimen (Fig. 8A ) by having an obtusely angular to slightly shouldered last whorl, with the presence of minor lamellae, while the protoconch, shell sculpture, and major lamellae (parietal, upper palatal, lower palatal and columellar) are identical. Therefore, we treat them as a morphological variant of the same species.

Figures

Figure 3. Living snails of A Lagocheilus klobukowskii (Morlet, 1885) B Lagocheilus landesi (Morlet, 1885) C Pupina crosseana Morlet, 1883 D Valiguna siamensis (Martens, 1867) E, F Valiguna sp. E notum or dorsal view and F hyponotum or ventral view G Succinea tenuis Morelet, 1865 and H Hypselostoma cambodjense Benthem Jutting, 1962. All not to scale.

Figure 8. Morphological variation among Hypselostoma cambodjense Benthem Jutting, 1962 populations A from locality no. 9 (topotype) B from locality no. 11 and C from locality no. 17. The insets show the apertural dentition. Abbreviation: p, parietal lamella; upl, upper palatal lamella; lpl, lower palatal lamella; c, columellar lamella.