Key to genera of Monomachidae

1. Female brachypterous or micropterous (Figs. 4, 10); male with radial cell of fore wing open apically (Figs. 7, 9, 13); clypeus longest medially, ventral margin broadly rounded to sinuate; mandible bidentate, teeth rounded to acute, subequal in size; basignath fusiform; m-cu intersecting Cu basad of Cu1b.................................................. Chasca

– Female macropterous; male, with the exception of one species ( M. paulus Musetti & Johnson), with radial cell of fore wing closed; if radial cell open, then ventral margin of clypeus with two small, submedian teeth; mandible with a large, truncate posterior tooth; basignath quadrate and m-cu intersecting Cu at Cu1b...................................... Monomachus