Macrogyrodactylus polypteri Malmberg, 1957* is a viviparous monogenean found on the skin and fins of the African freshwater fish Polypterus senegalus Cuvier. It was first reported by Malmberg (1957) from Gambia. Khalil (1964, 19G9) and Amirthalingam (19C5) recorded it on the same host species and Saoud & Mageed (1969) found it on P. bichir in the Sudan. Prudhoe (1957) described a new genus and species, Neogyrodactylus congolensis, on the skin of Clarias lazera from the Congo but Yamaguti (1963) considered this genus to be a synonym of Macrogyrodactylus. A third species, M. clarii Gussev, 1961 was reported on Clarias sp. from south Ethiopia and Ghana. On the basis of one specimen M. latest Paperna, 1969 was reported on Lates nilotica from Ghana. So far the species of the genus are confined to African freshwater fishes.