1	Apical half of mentum acute, triangular (Figs 25, 34–35)	2
–	Apical half of mentum rounded (Figs 26–29, 31–33) or quadrate (Fig. 30)	3
2	Punctures of frons and clypeus multisetigerous	Peltonotus sisyrus Jameson & Wada
–	Punctures of frons and clypeus unisetigerous	Peltonotus talangensis Jameson & Jakl
3	Apex of labrum weakly sinuate (Figs 23–24)	4
–	Apex of labrum bi-emarginate (Figs 21–22) to deeply bilobed (Fig. 20)	5
4	Apex of clypeus with weak, medial tubercle; lateral pillow of elytron (dorsal view) elongate-oval, extending more than half length of epipleuron; epipleuron as in Fig. 82	Peltonotus nasutus Arrow
–	Apex of clypeus lacking weak tubercle; lateral pillow of elytron (dorsal view) narrower at apex and broader at base, extending less than half length of epipleuron; epipleuron as in Fig. 80	Peltonotus morio Burmeister
5	Elytra with castaneous vittae or maculae (e.g., Figs 13, 18–19)	6
–	Elytra lacking vittae, entirely castaneous, reddish, or black	7
6	Elytral epipleuron in ventral view simple, lacking apical incision (Fig. 81)	Peltonotus mushiyaus Jameson & Wada
–	Elytral epipleuron in ventral view incised at apex (Fig. 91)	Peltonotus vittatus Arrow
7	Labrum with apex deeply bilobed (e.g., Fig. 20)	8
–	Labrum with apex bi-emarginate (e.g.,Figs 21–22)	13
8	Elytral epipleuron in ventral view simple, not emarginated (Fig. 83)	Peltonotus nethis Jameson & Wada
–	Elytral epipleuron in ventral view emarginated (e.g., Fig. 73)	9
9	Maxillary stipes with setae curly at apex (e.g., Fig. 41)	10
–	Maxillary stipes with setae straight, not curly at apex	11
10	Epipleural emargination with well-developed tooth in ventral view (Fig. 73)	Peltonotus brunnipennis Benderitter
–	Epipleural emargination with moderately developed tooth in ventral view (Fig. 77)	Peltonotus gracilipodus Jameson & Wada
11	Elytra entirely reddish (Fig. 17)	Peltonotus tigerus Jameson & Wada
–	Elytra entirely black	12
12	Lateral pillow of elytron (dorsal view) well-developed, extending medially at least ¼ elytral width, visible in ventral view (Fig. 88)	Peltonotus suehirogarus Jameson & Wada
–	Lateral pillow of elytron (dorsal view) moderately developed, extending medially about 1/8 elytral width, not visible in ventral view (Fig. 77)	Peltonotus podocrassus Jameson & Wada
13	Elytral epipleuron in ventral view broad, nearly parallel from base to near metacoxa, lacking emargination (Fig. 75, 84)	14
–	Elytral epipleuron in ventral view narrowing from base to near metacoxa (not parallel-sided), with or without emargination (e.g., Figs 76, 78–79)	15
14	Elytral epipleuron in ventral view with sparse, reddish, moderately long setae	Peltonotus favonius Jameson & Wada
–	Elytral epipleuron in ventral view without setae	Peltonotus pruinosus Arrow
15	Labial palpomere 2 greatly enlarged and dorsoventrally flattened, 2–3 times wider than palpomere 1 (e.g., Fig. 28)	16
–	Labial palpomere 2 not greatly enlarged and flattened, at most 1.5 times wider than palpomere 1 (e.g., Fig. 33)	17
16	Maxillary stipes with setae curly at apex (Fig. 41); lateral pillow of elytron (dorsal view) well-developed, visible in ventral view (Fig. 79)	Peltonotus malayensis Arrow
–	Maxillary stipes with setae straight, not curly at apex; lateral pillow of elytron (dorsal view) moderately developed, not visible in ventral view (Fig. 77)	Peltonotus silvanus Jameson & Wada
17	Body length more than 20 mm; epipleuron in ventral view simple, not emarginate (Fig. 78)	Peltonotus kyojinus Jameson & Wada
–	Body length less than 20 mm; epipleuron in ventral view simple or emarginate (Figs 74, 76, 85–86)	18
18	Elytral epipleuron emarginate in ventral view (Fig. 86)	19
–	Elytral epipleuron simple in ventral view (Figs 76, 85)	21
19	Elytral epipleuron in ventral view with round emargination (Figs 74, 86); not occurring in Mt. Bawang, Kalimantan region of Borneo	20
–	Elytral epipleuron in ventral view with elongate-oval emargination; Mt. Bawang, Kalimantan region of Borneo	Peltonotus adelphosimilis Jameson & Wada
20	Punctures of frons and clypeus mulitsetigerous, setae minute and/or short; elytral epipleuron as in Fig. 86; Borneo	Peltonotus similis Arrow
–	Punctures of frons and clypeus unisetigerous, setae minute; elytral epipleuron as in Fig. 74; Sumatra	Peltonotus cybele Jameson & Wada
21	Elytral epipleuron in ventral view terminating near metacoxa (Fig. 85)	Peltonotus rubripennis Miyake & Yamaya
–	Elytral epipleuron in ventral view extending posterior of metacoxa, terminating near sternite 3 (Fig. 76) Peltonotus fujiokai Jameson & Wada