Opisthoporus bernardii (Pfeiffer, 1862) Fig. 6E

Rhiostoma bernardii Pfeiffer, 1862: 45, 46, pl. 6, fig. 5. Type locality: Siam [Thailand]. Kobelt 1911: 761, pl. 111, figs 9, 10.

Cyclotus bernardii: Inkhavilay et al. 2019: 19, fig. 8d, e.

Opisthoporus bernardii: Do et al. 2020: 108, table 3.

Material examined.

Locality no. 9: CUMZ-CM043 (8 shells). Locality no. 13: CUMZ-CM127 (2 shells), CUMZ-CM118 (2 shells). Locality no. 10: CUMZ-CM062 (3 shells; Fig. 6E), CM063 (1 shell), CUMZ-CM064 (2 specimens in ethanol). The snails were found to live on the ground among leaf litter.

Distribution.

Cambodia, Laos and Thailand (Inkhavilay et al. 2019).

Remarks.

Opisthoporus bernardii was originally described from “Siam” [Thailand], and it has been reported from Cambodia (Fischer 1973a) and Laos (Inkhavilay et al., 2019). The diagnostic characters of this species are the depressed helicoid shell, with thick or thin periostracum, circular aperture, and a short to long sutural tube (accessory breathing device) located just behind an apertural lip. Pfeiffer (1862) provided details of the operculum, which is calcareous and has a multi-spiral plate-like shape, while the operculum of Rhiostoma is thick calcareous and has a multi-spiral cup shape (Egorov 2009).