P. siamensis:

BMNH 1897.10.8.126, holotype, 76.5 mm SL; Thailand: Chao Phraya basin, Bangpakong River . ANSP 59284 (1), 42.4 mm SL [holotype of Leiocassis bicolor ^ZBK] ; ANSP 59285-59289 (5), 37.6-45.6 mm SL [paratypes of Leiocassis bicolor ^ZBK]; Thailand: Chieng Mai . ANSP 60178 (1), 85.6 mm SL [holotype of Leiocassis albicollaris ^ZBK]; Thailand: Bangkok . CAS 94782, 64: 30.4-107.0; Cambodia: Ratanakiri Province, O Champha, 4-8 km upstream from its mouth into Tonle San near Te Veng .