Diplura C.L. Koch, 1850 is a mygalomorph genus with putative records from Central and South America. The type-species Diplura macrura (C.L. Koch, 1841), originally described from West Indies, is poorly known and represented only by its holotype. Most of the 20 species currently included in the genus lack modern taxonomic descriptions, as D. lineata (Lucas, 1857), from Rio de Janeiro state, Brazil. Males and females of Diplura macrura and D. lineata are herein redescribed. New junior synonyms of D. macrura are identified (Linothele bicolor (Simon, 1889), Diplura uniformis Mello-Leitão, 1923, and the two junior synonyms of the latter species, Thalerothele minensis Mello-Leitão, 1926 and T. aurantiaca Mello-Leitão, 1943). Also, two junior synonyms are established for D. lineata: Diplura fasciata (Bertkau, 1880) and Diplura nigridorsi (Mello-Leitão, 1924). The type-locality of D. macrura is corrected to São João del Rei, Minas Gerais state, Brazil. D. macrura is restricted to the state of Minas Gerais and D. lineata to the state of Rio de Janeiro. The type-locality of D. parallela (Mello-Leitão, 1923) is also corrected from Argentina to Paraná state, Brazil. The distribution of Diplura is now restricted from south Panama to north Argentina, excluding previous erroneous records for Cuba and West Indies. The six synonymies herein established help to clarify the genus composition, which includes now 17 valid species.