Key to males of the genus Sinotympana

1 Fore wing radial crossvein distinctly infuscated, radiomedial vein without infuscation, ventral margins of pygofer obovate, un- cal lobes slightly curved mediad............................................................ S. incomparabilis

- Fore wing radial and radiomedial crossveins distinctly infuscated, ventral margins of the pygofer parallel, uncal lobes straight................................................................................ S. caobangensis sp. nov.