1. Antennae longer, with 25 segments, its length longer than hind femur....... Gomphomastax Brunner von Wattenwyl, 1898.
1’ Antennae shorter, with 11~22 segments, its length not longer than hind femur..................................... 2
2. Apex of hind femur without spine........................................................................ 3
2’ Apex of the hind femur with 1~5 spines................................................................... 6
3. Antennae shorter, with 11 segments, its length almost as long as width; head not exceeding compound eyes............................................................................................ Myrmeleomastax Yin, 1984.
3’ Antennae shorter, with 12~19 segments, its length longer than width; head exceeding compound eyes.................. 4
4. Antennae shorter, with 19 segments, reaching the basal part of hind femur in male; face with promontory, parallel on both sides................................................................................................................................................................................... Sinomastax Yin, 1984.
4’ Antennae shorter, with 12~15 segments, not reaching the basal part of hind femur in male; promontory of face wider between antennae............................................................................................. 5
5. Antennae 13~15 segments......................................................... Ptygomastax Bienko, 1959.
5’ Antennae 12 segments............................................................ Angulomastax Zheng, 1985.
6. Antennae with 21~24 segments.................................................... Phytomastax Bienko, 1949.
6’ Antennae with 15 segments........................................................... Pentaspinula Yin, 1979.