Revision of the genus Chordodes (Gordiida: Nematomorpha) from Africa IV. Ultrastructural redescription of Chordodes congolensis Sciacchitano, 1933, Chordodes ferox Camerano, 1897, Chordodes madagascariensis (Camerano, 1893), Chordodes mobensis Sciacchitano, 1958 and reinterpretation of Chordodes maculatus Sciacchitano, 1958 and Chordodes kakandensis Sciacchitano, 1958

Six species of the genus Chordodes from Africa were investigated in order to certify their taxonomic descriptions and verify the species status. Scanning electron microscopy demonstrated that the female of Chordodes congolensis has seven types of areoles, while the females of C. ferox have six and the male and females of C. madagascariensis have four and five areolar types, respectively. The females of these three species have polymorphic crowned areoles with both short and long filaments, these areoles are only observed along the ventral groove. The female of Chordodes mobensis has five areolar types and we found that crowned areoles were present in clusters of 10–12 areoles. Chordodes maculatus has been synonymized with C. kolensis and C. kakandensis with C. schoutedeni, because no differences could be detected that justify these species as valid.