Key to species of the genus Platyscelis from China (based on males)

1 Lateral carina of elytra reaching sutural angle, visible completely in dorsal view................................... 2

- Lateral carina of elytra merging with epipleura, not reaching sutural angle, visible completely or only in anterior part in dorsal view............................................................................................... 3

2 Elytral surface without longitudinal carinae or indistinct; outer margin of protibiae straight, outer angle of apex rectangular; metatibiae weakly curved; apex of parameres nearly straight in lateral view (Fig. 34)................................................................................................. Platyscelis (Pleiopleura) ovata Ballion, 1878

- Elytral surface with longitudinal carinae obviously; distal part of outer margin of protibiae obviously curved to inner side, outer angle of apex obtuse; metatibiae obviously curved; apex of parameres curved to ventral side in lateral view (Fig. 36)................................................................. Platyscelis (Pleiopleura) striata Motschulsky, 1859

3 Anterior margin of pronotum deeply emarginate, strial punctures merging into longitudinal long furrows at sides, interstriae with extremely dense and coarse punctures; distal part of parameres wrapped in a hat (Figs. 29–30)................................................................................. Platyscelis (Platyscelis) subcordata Seidlitz, 1893

- Anterior margin of pronotum weakly emarginate or straight, strial punctures not merging into longitudinal long furrows at sides; distal part of parameres not wrapped in a hat (Figs. 5–28, 31–32).......................................... 4

4 Outer margins of parameres without hooks at apex in dorsal view (Figs. 7, 15)..................................... 5

- Outer margins of parameres with hooks at apex in dorsal view (Figs. 5, 9, 11, 13, 17, 19, 21, 23, 25, 27, 31)............. 6

5 Pronotum with sparse punctures on disc, moderately dense and shallow at sides, narrowly depressed or weakly flatted at sides of basal; elytra long oval; apex of protibiae moderately extended; protarsi wide, mesotarsi narrower than protarsi; apex of parameres strongly narrower than base in dorsal view and hook-liked curved to dorsal side in lateral view (Figs. 7–8)...................................................................... Platyscelis (Platyscelis) amdoensis Egorov, 1989

- Pronotum with dense punctures on disc, denser at sides, widely flatted at sides from base to middle; elytra short oval; apex of protibiae strongly extended; protarsi narrow, mesotarsi nearly equal to protarsi; apex of parameres weakly narrower than base in dorsal view and straight in lateral view (Figs. 15–16).............. Platyscelis (Platyscelis) brevis Baudi di Selve, 1876

6 Elytral surface covered with soft and thick setae (Figs. 37–38).................................................. 7

- Elytral surface covered with soft setae occasionally, especially at apex, or nearly without any setae.................... 8

7 Elytral surface with long thick setae (Fig. 38); metatibiae straight and narrow; parameres narrowing towards apex arcuately, outer margins with extremely weak hooks at apex in dorsal view, apex not curved to dorsal side in lateral view (Figs. 21–22).................................................................. Platyscelis (Platyscelis) freyi Kaszab, 1940

- Elytral surface with short thick setae (Fig. 37); metatibiae curved, wide and flat; parameres narrowing towards apex straightly, outer margins with long and sharp hooks at apex in dorsal view, apex curved to dorsal side in lateral view (Figs. 5–6)........................................................................ Platyscelis (Platyscelis) acutipenis sp. nov.

8 Elytral surface without longitudinal carinae or traces......................................................... 9

- Elytral surface with longitudinal carinae and traces.......................................................... 14

9 Posterior angles of pronotum rectangular, sharp and weakly protruded outward apically........................................................................................... Platyscelis (Platyscelis) suiyuana Kaszab, 1940

- Posterior angles of pronotum obtuse or rectangular, neither sharp nor protruded outward apically..................... 10

10 Pronotal punctures extremely dense and coarse and merged at sides; parameres wide and short in dorsal view (Fig. 27)...................................................................... Platyscelis (Platyscelis) licenti Kaszab, 1940

- Pronotal punctures unconnected at sides; parameres long in dorsal view (Figs. 9, 11, 13, 19)......................... 11

11 Parameres narrow, narrowing from base to apex gradually at sides in dorsal view (Figs. 9, 11); elytral punctures shallow, nearly disappeared at apex................................................................................... 12

- Parameres wide at base, emarginate at middle at sides in dorsal view (Figs. 13, 19); elytral punctures clear............. 13

12 Pronotum not depressed along lateral margins; outer margins of parameres with short and obtuse hooks at apex in dorsal view, apex curved to ventral side in lateral view (Figs. 9–10).... Platyscelis (Platyscelis) angusticollis angusticollis Kaszab, 1940

- Pronotum depressed along lateral margins from base to middle; outer margins of parameres with long and sharp hooks at apex in dorsal view, apex straight in lateral view (Figs. 11–12).... Platyscelis (Platyscelis) angusticollis platytarsis Kaszab, 1940

13 Elytra apically wide and nearly straight, emarginate at sutural angle, surface with dense and deep punctures; parameres moderately narrowing towards apex in dorsal view, apex curved to dorsal side in lateral view (Figs. 13–14)................................................................................ Platyscelis (Platyscelis) bogatshevi Egorov, 1989

- Elytra apically round, not emarginate at sutural angle, surface with sparse punctures; parameres strongly narrowing towards apex in dorsal view, apex curved to ventral side in lateral view (Figs. 19–20)..................................................................................................... Platyscelis (Platyscelis) densipunctata sp. nov.

14 Lateral carina of elytra wide, visible completely in dorsal view........... Platyscelis (Platyscelis) confusa Schuster, 1934

- Lateral carina of elytra narrow, apex not visible in dorsal view occasionally...................................... 15

15 Punctures extremely dense and moderately coarse on head; pronotal punctures dense and coarse at sides, and merged partially; parameres obviously wide in dorsal view, apex curved to dorsal side occasionally in lateral view (Figs. 23–24).......................................................................... Platyscelis (Platyscelis) gebieni Schuster, 1915

- Punctures dense and fine on head; pronotum with unconnected oval dense and fine punctures at sides; parameres narrow in dorsal view, dorsal side straight in lateral view (Figs. 25–26)................. Platyscelis (Platyscelis) helanensis sp. nov.