The identities and the relationships of Odonteucoila Ashmead, 1903, Coneucoela Kieffer, 1909, and Trichoplasta Benoit, 1956, are discussed and the re-defined genera are described. The use of some morphological terms are defined and other new terms are proposed. Lectotypes are designated for Odonteucoila chapadae and Coneucoela brasiliensis (type-species of the respective genera); four new synonymies and fourteen new combinations are proposed. Odonteucoila auct. is considered polyphyletic. The re-defined genus Odonteucoila is placed in the Chrestosema group of genera and appears to have a strictly Neotropical distribution. Species from other parts of the world, previously assigned to Odonteucoila, are transferred to Trichoplasta, which is closely related to Rhoptromeris. The type-species of Trichoplasta, T. basilewskyi Benoit, 1956, is synonymized with T. tanganyikensis (Weld, 1944) n. comb. (originally described in Coneucoela). Coneucoela brasiliensis Kieffer, 1909, is the only recognized Coneucoela species and it is considered to belong to the Ganaspis complex of genera. A cladistic analysis of the Rhoptromeris group of genera concludes the paper.