Rhiostoma sp.

Inkhavilay, Khamla, Sutcharit, Chirasak, Bantaowong, Ueangfa, Chanabun, Ratmanee, Siriwut, Warut, Srisonchai, Ruttapon, Pholyotha, Arthit, Jirapatrasilp, Parin & Panha, Somsak, 2019, Annotated checklist of the terrestrial molluscs from Laos (Mollusca, Gastropoda), ZooKeys 834, pp. 1-166 : 1

Rhiostoma sp.

Material examined.

Specimens from limestone outcrops in Ngoy Town, Ngoy District, Luang Phrabang Province (Figs 11E, 18F).

Remarks.

These specimens differ from Rhiostoma morleti , R. marioni , R. christae Thach, 2016 and R. herosae Thach & Huber in Thach, 2017 from Laos and Vietnam in having a long, descending and curved detached-whorl (proboscis-like detached-whorl), an aperture opened subventrally, and with a short and complete tubular accessory respiratory structure close to the aperture. In contrast, these four nominal species have a short to absent detached-whorl, a complete tubular or canal-like accessory respiratory structure, and an aperture opened laterally.