The taxonomic status of the limacoid genus Macrochlamys Gray, 1847 in Thailand has long been plagued by much ambiguity due to the inability to distinguish members from each other, and a few other genera, by shell morphology alone. The taxonomy of the Thai species is evaluated resulting in recognition of seven species, including five new species. The new species, Macrochlamys aurantia, M. coleus and M. tanymentula from Kanchanaburi Province (West Thailand), and M. caverna and M. lemma from Lopburi Province (Central Thailand), are distinguished and described based on shell, animal colouration, radula and genitalia characters. The status of Macrochlamys brunnea Möllendorff, 1902b is at present unclear. Although described from Bangkok, no material identifiable as this species was found in recent extensive surveys and it is provisionally retained in the genus without anatomical evaluation. Macrochlamys kelantanensis Möllendorff, 1902a is re-described with additional morphological and anatomical information. The five new species appear to have a restricted distribution in Western and Central Thailand, whereas M. kelantanensis is more wide-ranging, from Thailand to Malaysia. Detailed descriptions and illustrations of the shell morphology, external morphology, genital anatomy and radulae are provided. The results show that despite the shells being morphologically similar, aspects of classical morphology based taxonomy for Macrochlamys species, especially the genitalia morphology, remain useful and reliable for species delimitation.

The taxonomic status of the limacoid genus Macrochlamys Gray, 1847 in Thailand has long been plagued by much ambiguity due to the inability to distinguish members from each other, and a few other genera, by shell morphology alone. The taxonomy of the Thai species is evaluated resulting in recognition of seven species, including five new species. The new species, Macrochlamys aurantia, M. coleus and M. tanymentula from Kanchanaburi Province (West Thailand), and M. caverna and M. lemma from Lopburi Province (Central Thailand), are distinguished and described based on shell, animal colouration, radula and genitalia characters. The status of Macrochlamys brunnea Möllendorff, 1902b is at present unclear. Although described from Bangkok, no material identifiable as this species was found in recent extensive surveys and it is provisionally retained in the genus without anatomical evaluation. Macrochlamys kelantanensis Möllendorff, 1902a is re-described with additional morphological and anatomical information. The five new species appear to have a restricted distribution in Western and Central Thailand, whereas M. kelantanensis is more wide-ranging, from Thailand to Malaysia. Detailed descriptions and illustrations of the shell morphology, external morphology, genital anatomy and radulae are provided. The results show that despite the shells being morphologically similar, aspects of classical morphology based taxonomy for Macrochlamys species, especially the genitalia morphology, remain useful and reliable for species delimitation

Species of the genus Opisthoporus Benson in L. Pfeiffer, 1851 (family Cyclophoridae) occurring in Vietnam are reviewed and presented. In total, three species are included: Opisthoporus beddomei Dautzenberg & Fischer, 1908; O. lubricus Dautzenberg & Fischer, 1908; and O.thuathienhuensis, new species. Opisthoporusthuathienhuensis, new species, differs most distinctly from related congeners by its small inverted U-shaped breathing tube that has its distal end touching the last whorl. The new species is known only from limestone hills of Thua Thien Hue Province, central Vietnam, where terrestrial gastropod fauna is diverse, but relatively poorly known. This discovery represents the first record of the genus Opisthoporus in central Vietnam. A checklist of Opisthoporus taxa (mainly literature data) is presented.