A new genus Filexilia, is established to accommodate the A. tenella-group of Ameira Boeck, 1865 (Harpacticoida, Ameiridae), comprising A. attenuata Thompson, 1893; A. tenella Sars, 1907; A. longicaudata Nicholls, 1939; A. brevipes Kunz, 1954; A, pestae Petkovski, 1955; A. longifurca Bodin, 1964; A. gravellicola Guille & Soyer, 1966; A. intermedia Galhano, 1970; A. brevipes pestae Petkovski, 1955 sensu Marinov(1971); A. brevipes Kunz, 1954 sensu Apostolov (1977); and A. tenella Sars, 1907 sensu Kunz (1983).Ameira longicaudata Nicholls, 1939, a permanently invalid name as a primary homonym of A. longicaudata T. Scott, 1892 (now type-species of Stenocopia Sars, 1907), is replaced by Filexilia trisetosa nom. n. and designated as the type-species. As a result of re-examination of the type material, A. attenuata is reinstated from its status of species incertae sedis in Ameira (Lang, 1948) as Filexilia attenuata (Thompson, 1893) comb. n., and A. tenella Sars, 1907 is relegated to a junior synonym of the latter. Ameira tenella Sars, 1907 sensu Kunz (1983) is regarded as a distinct species F. azorica sp. n. Ameira longifurca, previously considered a probable synonym of A. tenella by Moore (1976), is confirmed as a valid species F. longifurca (Bodin, 1964) comb. n. Ameirapestae, relegated to a subspecies or forma of A. brevipes (Lang, 1965), is reinstated at the species level. Ameira brevipes pestae Petkovski, 1955 sensu Marinov (1971) is sufficiently distinct from the latter to warrant the erection of a new species F. marinovip. n. Ameira brevipes Kunz, 1954 sensu Apostolov (1977) is regarded as species inquirenda in Filexilia whereas A. brevipes f. pontica Apostolov, 1969 is rejected.Updated descriptions are given for both sexes off. trisetosa, F. attenuata and F. longifurca. Keys to the species of Filexilia and Sicameira Klie, 1950 are presented and the phylogenetic relationships of both genera are discussed. Ameira bengalensis Rao & Ganapati, 1969 is transferred as the type species of Glabrameira gen. n.