Abstract
Adults of three new species are described for the first time. Unionicola (Pentatax) thaiensis n. sp. is described from Thailand and resembles U. bonzi (Claparede) and U. imamurai Hevers. U. (Polyatax) heardi n. sp. is described from Thailand and resembles U. scutigera Viets, U. neokoenikei Viets and U. japonensis Viets. U. (Parasitatax) brandti n. sp. is described from Thailand and Laos and resembles U. diversipes Viets and U. tumida (Wolcott). These three new species were found in fresh water mussels.