Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species

16 Japonia anceps sp. n. 16A Frontal view, shell 6.0 mm high 16B Same shell, umbilical view 16C Same shell, right lateral view (Malaysia, Sabah, Interior Province, Crocker Range N.P., Gua Laing c. 12 km North of Keningau, RMNH.5003957, holotype) 17 Diplommatina bidentata sp. n. 17A Frontal view, shell 2.3 mm high 17B Same shell, frontal view, with position of internal teeth indicated (Malaysia, Sabah, Sabah, Tawau Province, Batu Baturong c. 50 km W.S.W. of Lahad Datu, RMNH.5003954, holotype) 18 Diplommatina tylocheilos sp. n. 18A Frontal view, shell 1.8 mm high 18B Same shell, right lateral view, with position of internal teeth indicated (Malaysia, Sabah, Gunung Trusmadi slopes, Gua Loloposon, RMNH.5003953, holotype).