Abstract
Salween River basin's karst ecosystems in southeastern Myanmar remain largely unexplored and are likely to harbour a high terrestrial snail diversity that are often associated with high levels of snail endemism. Here, an outstanding group of new karst-associated terrestrial snails, Burmochlamys gen. nov., are discovered. A study of the comparative morphological and anatomical data reveals that the reproductive tract and radula of this new genus are closely related to the helicarionid genus Sophina Benson, 1859 but shell morphology (shape, size, and sculpture) and mantle extensions are distinct from the latter genus. Burmochlamys gen. nov. now consists of four known nominal species, B.cassidula comb. nov., B.cauisa comb. nov., B.perpaula comb. nov., and B.poongee comb. nov., and five new species; B.albida sp. nov., B.fasciola sp. nov., B.moulmeinica sp. nov., B.versicolor sp. nov., and B.whitteni sp. nov. The highlight is that the members of the new genus show site-specific endemism, being restricted to karstic habitat islands of the Salween River basin. In addition, the discovery supports that the unique and complex structure of Salween River basin's karst ecosystems are habitats in which the terrestrial malacofauna have speciated and become endemic.