Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia Author Foon, Junn Kitt Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia & Rimba, 22 - 3 A, Casa Kiara 2, Jalan Kiara 5, 50480 Kuala Lumpur, Malaysia Author Clements, Gopalasamy Reuben Rimba, 22 - 3 A, Casa Kiara 2, Jalan Kiara 5, 50480 Kuala Lumpur, Malaysia & Department of Biological Sciences, Sunway University, No. 5 Jalan Universiti, 47500 Bandar Sunway, Selangor, Malaysia Author Liew, Thor-Seng Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia & Rimba, 22 - 3 A, Casa Kiara 2, Jalan Kiara 5, 50480 Kuala Lumpur, Malaysia thorsengliew@gmail.com text ZooKeys 2017 2017-07-04 682 1 94 http://dx.doi.org/10.3897/zookeys.682.12999 journal article http://dx.doi.org/10.3897/zookeys.682.12999 1313-2970-682-1 0AE82225C67E4D908BBEC30124E6C312 FFBCE458FFDBFFC93B2EFFB2F562FFBE 3484859 Opisthostoma trapezium van Benthem Jutting, 1952 Figure 14C Materials examined. Prk 47 Kanthan : BOR/MOL 9071, BOR/MOL 9164. mykarst-027: BOR/MOL 9035, BOR/MOL 9126. Prk 53 Hill KF : BOR/ MOL 10780 .mykarst-025: BOR/MOL 9397, BOR/MOL 9421, BOR/MOL 9489, BOR/MOL 9515 . Distribution. Restricted to central and upper Kinta Valley only. Remarks. Distinguished from congeners by its box-like shell shape, pronounced but widely spaced radial ribs and the direction the aperture is facing is parallel to the coiling axis of the apical whorl. Previously known from Gunung Kanthan only ( Maassen 2001 ).