Seven new species of Hypselostomatidae are described from the Chinese province Guangxi: Angustopila dominikae Páll-Gergely & Hunyadi, sp. n., A. fabella Páll-Gergely & Hunyadi, sp. n., A. subelevata Páll-Gergely & Hunyadi, sp. n., A. szekeresi Páll-Gergely & Hunyadi, sp. n., Hypselostoma socialis Páll-Gergely & Hunyadi, sp. n., H. lacrima Páll-Gergely & Hunyadi, sp. n. and Krobylos sinensis Páll-Gergely & Hunyadi, sp. n. The latter species is reported from three localities. All other new species are known only from the type locality. Specimens nearly identical to the type specimens of Angustopila huoyani Jochum, Slapnik & Páll-Gergely, 2014 were found in a cave in northern Guangxi, 500 km from the type locality. Adult individuals of Angustopila subelevata sp. n. (shell height = 0.83–0.91 mm, mean = 0.87 mm) and A. dominikae sp. n. (shell height of the holotype = 0.86 mm) represent the smallest known members of the Hypselostomatidae, and thus are amongst the smallest land snails ever reported. We note that Pyramidula laosensis Saurin, 1953 might also belong to Krobylos. Paraboysidia neglecta van Benthem Jutting, 1961, which was previously included in Angustopila, is classified in Hypselostoma.

A review of the microgastropod genus Systenostoma is provided. Thai and Malaysian species are transferred to a new genus, Angustopila (type species: Systenostoma tamlod Panha & Burch 1999). A new subterranean Angustopila species is described here. Conchologically, the new species is most similar to the cave-dwelling, Thai A. tamlod (Panha & Burch, 1999). One Thai species (Systenostoma edentata) is transferred to the genus Hypselostoma. Vietnamese members remain in the genus Tonkinospira (nomen novum) for Systenostoma Bavay & Dautzenberg 1908 (non Systenostoma Marsson 1887). A comprehensive map of former Systenostoma species is presented. SEM and NanoCT images, including a video of A. huoyani sp. n. internal shell morphology, provide novel perspectives of the shells of Angustopila and of the scarcely known Vietnamese Tonkinospira species. The biology of these snails is not yet known but collection localities suggest a troglophilic ecology.

The Asian land snail species Bensonella plicidens (Benson, 1849) is enigmatic due to its extremely disjunct distribution. That is, it has been reported from the Himalaya, in Eastern China and Japan, and one subspecies was described from Taiwan. This distribution type has not been reported in any other land snails. It is also notable that some specimens identified as B. plicidens have ‘normal’ plica-like apertural barriers, while others have hook-like projections in the middle of the interrupted barriers, and the hooks point to the outside of the aperture. We examined several Bensonella samples and arrived at the following conclusions: (1) Bensonella plicidens has normal plica-like apertural barriers without hooks, and the Himalayan species with hook-like barriers is a new species, Bensonella hooki Páll-Gergely sp. nov.; (2) the species with hooked barriers recorded from Japan, Taiwan and eastern China differs from both Himalayan species (i.e. Bensonella plicidens and B. hooki sp. nov.), and the name Bensonella lakainguta Hwang, 2014 is available for it; (3) hooked apertural barriers have evolved repeatedly in the Hypselostomatidae and therefore cannot be used as a distinguishing character for the genus Bensonella. Bifidaria (Bensonella) landourensis Pilsbry, 1915 and Boysidia (Bensonella) qingliangfengensis F. Fang, J. Wang and Y. Chen, 2015 are junior synonyms of B. plicidens and B. lakainguta, respectively. Since the type species of Paraboysidia Pilsbry, 1917 and Bensonella Pilsbry and Vanatta, 1900 are very similar in all important shell characters, we consider the former to be a junior synonym of the latter. http://www.zoobank.org/urn:lsid:zoobank.org:pub:0E1DA12A-0ECA-4280-B9ED-C99A43B14686

Two new, extremely small land snail species, Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp. and Angustopila psammion Páll-Gergely, Vermeulen & Anker n. sp. are described from northern Vietnam and northern Laos, respectively. The former is characterized by a rough surface sculpture and bears tiny mud granules arranged in a pattern of radial lines on its shell surface. The latter species is the new global record-holder of the tiniest land snail title, with a shell width of 0.6–0.68 mm and a shell height of 0.46–0.57 mm. These measurements surpass the former records of Angustopila pallgergelyi and Acmella nana.

Previously only a single plectopylid species, Helix laomontana L. Pfeiffer, 1862 was reported from Laos. Here we erect Naggsia Páll-Gergely & Muratov, gen. n. for H. laomontana based on the description of its reproductive anatomy and radula. Another species, Hunyadiscus saurini Páll-Gergely, gen. & sp. n. is described from Northern Laos based on conchological data. Helix (Plectopylis) andersoni Blanford, 1869, which is known from the Burmese-Chinese border region, is also classified within Hunyadiscus Páll-Gergely, gen. n. A third species, Gudeodiscus (Gudeodiscus) messageri raheemi Páll-Gergely & Hunyadi, 2015 is reported from Laos for the first time. The new localities represent the westernmost sites of the genus Gudeodiscus. The reproductive anatomy of the latter species is described.

Land snails were collected for the project ‘Conserving Myanmar’s Karst Biodiversity’ from the limestone karsts in Mon, Kayin, and Shan states and in the regions of Tanintharyi and Mandalay between 2015 and 2017, through cooperation with Fauna and Flora International (FFI) and the Forestry Department of Myanmar. Here, we report on a portion of the collection, and list 17 species from seven genera of the Hypselostomatidae microsnails. Three new species from two genera are described as Bensonella taiyaiorum Tongkerd & Panha, sp. nov., B. lophiodera Tongkerd & Panha, sp. nov., and Gyliotrachela aunglini Tongkerd & Panha, sp. nov. All new species are known only from the type locality in Shan State (Bensonella) and Kayin State (Gyliotrachela). A new combination of Acinolaemus dayanum and three newly recorded species, namely A. cryptidentatus, B. anguloobtusa and G. hungerfordiana are discussed. The low morphological variability of the widely distributed G. hungerfordiana is discussed, and two species are proposed for formal synonymisation. Constituting the first records for Myanmar, five species of Bensonella and two species of Acinolaemus were collected.