The genus Mesocriconema is diagnosed and 90 valid species and their synonyms are listed. The main diagnostic characteristics of the species included are presented in tabular form. The synonymy of Pakcriconemoides with Mesocriconema is supported.

The genus Criconemoides is diagnosed and lists are given of the valid species with their synonyms, of species inquirendae vel dubiae and of departures. The main diagnostic features of the species included are presented in tabular form.