Twenty-one new species are described in a new genus, Mexitettix. Another new genus, Mexacris, is erected for two species previously placed in Phaedrotettix. Both new genera are known only from eastern Mexico — from Coahuila south to Vera Cruz. Mexitettix extends south to Hidalgo. Both species consist of entirely flightless species whose forewings are small pads which extend from the prontum to cover the auditory tympana. Mexitettix lives among weeds and bushes in dry country, often among rocks in eroded landscapes and mountain sides.