Lineagona n. gen., is established for two species from either side of the Rio Grande River in Texas and México. Lineagona culmenicola n. sp., is from the vicinity of Monterrey, Nueva Leon, México, and L. chisosi (Loomis, 1963) n. comb. ex Cleidogona Cook, in Cook & Collins 1895 is from Big Bend National Park, Texas, USA. A key to the genera of Cleidogonidae is provided and gonopod terminology in Cleidogonidae is updated.