Key to the Madagascar Orphninae genera (both sexes)

1. Protibiae with 2 outer teeth apically and 1 much smaller outer tooth basally (Fig. 7 D)........... Pseudorphnus Benderitter

- Protibiae with 3 outer teeth in apical half (Figs. 10 H, 30C, 28F).................................................2

2. Body length smaller (usually less than 7 mm); lateral margin of pronotum with 4 long setae: 2 near anterior margin, 1 in the middle, and 1 near posterior margin; some or all these setae may be abraded, but 4 chaetiferous punctures are always distinct; left and right mandibles may differ strongly in length in males, and frontoclypeus is somewhat asymmetrical in such cases; disc of pronotum smooth, without processes or excavations.................................. Madecorphnus Paulian

- Body length larger (usually longer than 7 mm); lateral margin of pronotum with numerous setae (at least more than 10) evenly distributed along the margin, setae may differ strongly in length; left and right mandibles of about same length, frontoclypeus symmetrical; disc of pronotum may be with more-or-less developed tubercles, ridges, and excavations in males........... 3

3. Eyes smaller (width of eye in dorsal view more than 7 times smaller than distance between eyes); propleurae with a longitudinal ridge bearing a row of setae parallel to lateral margin of pronotum; disc of pronotum with more-or-less developed tubercles, ridges, and excavations in males, and smooth in females; apical outer tooth of protibia in males directed laterally, at reasonable angle to internal margin of tibia (Fig. 30 C)....................................... Triodontus Westwood

- Eyes larger (width of eye in dorsal view less than 4 times smaller than distance between eyes); propleurae without a longitudinal ridge, only with a sparser row of setae; disc of pronotum with 2 feebly developed tubercles in middle or without tubercles; apical outer tooth of protibia almost parallel to internal margin of tibia (Fig. 28 F)........ .. Renorphnus Frolov & Montreuil