Key to the species of Sinocyrtaspis (males)

1 Posterior margin of 10th abdominal tergite with 1 notch; cercus not reaching posterior margin of 10th abdominal tergite.... 2

- Posterior margin of 10th abdominal tergite split; cercus surpassing posterior margin of 10th abdominal tergite............ 3

2 The notch on posterior margin of 10th abdominal tergite slightly wider than long, apex of genitalia positioned on the notch (Chang et al. 2012, Fig. 2C)................................................................. S. brachycerca

- The notch on posterior margin of 10th abdominal tergite narrow and long, apex of genitalia not positioned on the notch (Chang et al. 2012, Fig. 1C)........................................................................ S. angustisulca

3 Basal area of cercus with 1 spiniform process............................................................... 4

- Basal area of cercus without spiniform process.............................................................. 5

4 Apical half of 10th abdominal tergite rectangular (Chang et al. 2012, Fig. 3E); 1/3 basal area of cercus on dorsal margin with 1 long spiniform process........................................................................... S. spina

- Apical half of 10th abdominal tergite cardiac (Fig. 6G); 1/3 basal area of cercus on dorsal margin with 1 short spiniform process................................................................................... S. cardia sp. nov.

5 Subapex of cercus extending ventrally and dorsally, twisted, apex lamellate (Fig. 5I)............ S. hengshanensis sp. nov.

- Subapex of cercus neither extending nor twisted.............................................................6

6 Cercus strongly bent inner-ventrally, inner margin of apical half lamellate extended (Fig. 2I).................. S. truncata

- Apical half of cercus moderately bent inward, inner margin of subapical area conspicuously extended inner-dorsad, phylloid (Fig. 1G)..................................................................................... .. S. lushanensis