Shell valves of A, B Scabies songkramensis sp. n., A holotype ZMMSU 00500 and B paratype ZMMSU 00501. C Scabies crispata, Brandt collection SMF 188682 from Bangkok, Thailand D Scabies nucleus Brandt collection SMF 198394 from Mekong River, Pakse, Laos E Scabies phaselus Brandt collection SMF 188695 from Takrong River, Nakon Ratchsrima, and F hinge plates of Scabies songkramensis sp. n., holotype, with illustrating and measurements terminology. Abbreviations: aa, anterior adductor muscle scar; lt, lateral teeth; pa, posterior adductor muscle scar; pl, pallial line; pt, pseudocardinal tooth; H, height of valves; L, length of valves; and W, width of valves.