First record of subterranean rissoidean gastropod assemblages in Southeast Asia (Mollusca, Gastropoda, Pomatiopsidae)

In February 2017 we investigated several caves and karstic springs in Laos for the presence of underground freshwater gastropod species. We report previously unrecorded freshwater gastropod assemblages in the largest cave in Laos, Tham Khon Dôn, and in the third largest cave, Pha Soung, in Khammouane Province, with single finds in Na Li Cave (Khammouane Province), an unnamed cave near Vieng Thong (Bolikhamsay Province) and a small karst spring near Phonsavan (Xianghouan Province). All 15 species recorded and described herein are new to science. Four species are assigned to the new genus Pseudoiglica : P.pseudoiglica sp. n. , P.olsavskyi sp. n. , P.kameniari sp. n. , and P.phonsavanica sp. n. Three species are assigned to the new genus Thamkhondonia : T.moureti sp. n. , T.vacquiei sp. n. , and T.smidai sp. n. Eight species are assigned to the genus Tricula Benson, 1843: T.valenasi sp. n. , T.davisi sp. n. , T.spelaea sp. n. , T.lenahani sp. n. , T.reischuetzorum sp. n. , T.phasoungensis sp. n. , T.bannaensis sp. n. , and T.viengthongensis sp. n.