1	Hind wings shortened	2
–	Hind wings absent	3
2	Pronotum approx. as wide as long; apicale of aedeagus arrowheaded (Figs 25–26, in Masumoto 1989). China (Taiwan)	Pseudoogeton uenoi
–	Pronotum approx. 1.4 times as wide as long; apicale of aedeagus simply short fusiform. Japan	Pseudoogeton kimurai
3	Body blackish brown, with ferruginous tinge, dorsal surface strongly shining; apicale of aedeagus elongated equilateral triangular, lateral sides gradually narrowed forward. Laos	Pseudoogeton endoi
–	Black, or with violet and sericeous tinge; lateral sides of apicale of aedeagus abruptly narrowed forward	4
4	Pronotum widest in middle (Fig. 3); aedeagus stouter, apicale length/width < 1.5 (Figs 5–7). China (Sichuan)	Pseudoogeton maoxianum sp. n.
–	Pronotum widest behind middle; aedeagus slender, apicale length/width > 1.5	5
5	Dorsal surface of body with violet tinge; pronotum hemispherical; striae on elytra fine and shallow, intervals almost not punctate. China (Sichuan)	Pseudoogeton gebieni
–	Dorsal surface of body black, pronotum moderately convex and transverse; striae on elytra strong and deep, intervals with clear punctures. China (Sichuan)	Pseudoogeton amplipenne