Abstract We present reviews of the Sabah (Malaysia, on the island of Borneo) species of the following problematical genera of land snails ( Mollusca , Gastropoda ): Acmella and Anaglyphula ( Caenogastropoda : Assimineidae ); Ditropopsis ( Caenogastropoda : Cyclophoridae ); Microcystina ( Pulmonata : Ariophantidae ); Philalanka and Thysanota ( Pulmonata : Endodontidae ); Kaliella , Rahula , ( Pulmonata : Euconulidae ); Trochomorpha and Geotrochus ( Pulmonata : Trochomorphidae ). Next to this, we describe new species in previously revised genera, such as Diplommatina ( Diplommatinidae ); Georissa ( Hydrocenidae ); as well as some new species of genera not revised previously, such as Japonia ( Cyclophoridae ); Durgella and Dyakia ( Ariophantidae ); Amphidromus , and Trachia ( Camaenidae ); Paralaoma ( Punctidae ); Curvella ( Subulinidae ). All descriptions are based on the morphology of the shells. We distinguish the following 48 new species: Acmella cyrtoglyphe , Acmella umbilicata , Acmella ovoidea , Acmella nana , Acmella subcancellata , Acmella striata , and Anaglyphula sauroderma ( Assimineidae ); Ditropopsis davisoni , Ditropopsis trachychilus , Ditropopsis constricta , Ditropopsis tyloacron , Ditropopsis cincta , and Japonia anceps ( Cyclophoridae ); Diplommatina bidentata and Diplommatina tylocheilos ( Diplommatinidae ); Georissa leucococca and Georissa nephrostoma ( Hydrocenidae ); Durgella densestriata , Dyakia chlorosoma , Microcystina microrhynchus , Microcystina callifera , Microcystina striatula , Microcystina planiuscula , and Microcystina physotrochus ( Ariophantidae ); Amphidromus psephos and Trachia serpentinitica ( Camaenidae ); Philalanka tambunanensis , Philalanka obscura , Philalanka anomphala , Philalanka rugulosa , and Philalanka malimgunung ( Endodontidae ); Kaliella eurytrochus , Kaliella sublaxa , Kaliella phacomorpha , Kaliella punctata , Kaliella microsoma , Rahula delopleura , ( Euconulidae ); Paralaoma angusta ( Punctidae ); Curvella hadrotes ( Subulinidae ); Trochomorpha trachus , Trochomorpha haptoderma , Trochomorpha thelecoryphe , Geotrochus oedobasis , Geotrochus spilokeiria , Geotrochus scolops , Geotrochus kitteli , Geotrochus subscalaris , and Geotrochus meristorhachis ( Trochomorphidae ).