9 Ditropopsis davisoni sp. n. 9A Frontal view, shell 1.5 mm wide 9B Back view (Malaysia, Sabah, Upper Padas valley, Matang River South of Long Pasia, RMNH.5003917, holotype) 10 Ditropopsis trachychilus sp. n. 10A Frontal view, shell 2.3 mm high 10B Umbilical view 10C Frontal view, shell 2.7 mm high (10A, 10B Malaysia, Sabah, Crocker Range N.P., near the km 54 marker on the road Kota Kinabalu-Tambunan, Gunung Mas, RMNH.5003918, holotype, shell partly reconstructed; 10C Malaysia, Sabah, Kinabalu N.P., Kotal’s route between 2924–3048 m) 11 Ditropopsis koperbergi (Zilch, 1955). 11A Frontal view, shell 1.9 mm high 11B Umbilical view 11C Operculum, frontal view, diameter 0.65 mm 11D Operculum, lateral view (Malaysia, Sabah, Danum Valley Conservation Area, V 9881).