Male, anterior, copulatory parts, Onchidium melakense A, C Sumatra, [1723] (UMIZ 00001) B, E, F Peninsular Malaysia, holotype [5979] (USMMC 00075) D, G, H Peninsular Malaysia, holotype [5982] (USMMC 00076) A stalk and penial hooks B penial hook C penial hooks D flat disc at distal end of flagellum of penial accessory gland (the arrow indicates the hole through which the hollow spine protrudes) E hollow spine F hollow spine tip G hollow spine H hollow spine tip. Scale bars: 300 μm (A), 10 μm (B, C, F), 100 μm (D, G, H), 200 μm (E).

 
 
  Part of: Dayrat B, Goulding TC, Khalil M, Apte D, Tan SH (2019) A new species and new records of Onchidium slugs (Gastropoda, Euthyneura, Pulmonata, Onchidiidae) in South-East Asia. ZooKeys 892: 27-57. https://doi.org/10.3897/zookeys.892.39524