leatherleaf slug, Veronicellidae Gray, 1840

According to the following paper (The slugs and semislugs of Sabah, Malaysian Borneo (Gastropoda, Pulmonata: Veronicellidae, Rathouisiidae, Ariophantidae, Limacidae, Philomycidae)), maybe it resembles to Valiguna flava (Heynemann, 1885). But the genitalia has to be examined to determine the species.