Key to the species of Paragavialidium Zheng

1. Lateral spines of pronotum pointing laterad (Figs. 2–3)....................................................... 2

- Lateral spines of pronotum slightly curved forward (Figs. 4–9).................................................. 3

2. Width of vertex about 1.5 times wider than width of one eye; without a pair of abbreviated carinae beween shoulders (Fig. 2); lower margins of middle femora with two teeth (Fig. 10)...................................... P. orthacanum Zheng

- Width of vertex about 1.9 times wider than width of one eye; with a pair of abbreviated carinae beween shoulders (Figs. 3); lower margins of middle femora with three teeth (Fig. 11)................................. P. emeiensis Zheng et Cao

3. Middle of anterior margin of pronotum with a cylindrical finger-shaped process (Fig. 10)............................. 4

- Middle of anterior margin of pronotum with a triangular finger-shaped process (Fig. 17)............................. 5

4. Middle of anterior margin of pronotum with a long cylindrical finger-shaped process; width of vertex about 2.9 times wider than width of one eye; without a pair of abbreviated carinae beween shoulders; lower margins of middle femora with three teeth................................................................................ P. tridentatum Zheng

- Middle of anterior margin of pronotum with a short cylindrical finger-shaped process; width of vertex about 2.0 times wider than width of one eye; with a pair of abbreviated carinae beween shoulders; lower margins of middle femora with two teeth................................................................................ P. serrifemura Zheng et Cao

5. Width of vertex about 1.3 times wider than width of one eye; lower margins of fore femur with one teeth............................................................................................ P. longzhouensis Zheng et Jiang

- Width of vertex about 1.6–2.0 times wider than width of one eye; lower margins of fore femur with two teeth............6

6. Width of vertex about 1.6 times wider than width of one eye; length of pronotum which surpassing behind top of hind femur about 6–7 mm; length of first segment of posterior tarsus equal to third.......................... P. curivispinum Zheng

- Width of vertex about 2.0 times wider than width of one eye................................................... 7

7. Lower margins of fore femur with two teeth; third pulvillus of first segment of posterior tarsus equal to first and second............................................................................. P. sichuanensis Zheng, Wang et Shi

- Lower margins of fore femur with three teeth; third pulvillus of first segment of posterior tarsus longer than first and second.8

8. Apex of hind pronotal process truncate; wings reaching top of hind process of pronotum.... P. hainanensis (Zheng et Liang)

- Apex of hind pronotal process concave; wings not reaching top of hind process of pronotum................................................................................................ P. serrimarginis Deng et Zheng, sp. nov.