Fifteen specimens of Pteromylaeus bovinus (Geoffroy St. Hilaire) from the Tunisian coast were examined for ectoparasites during 1996-1998. Myliocotyle pteromylaei gn. et sp. n. found on gills of twelve host specimens is described and illustrated. It differs from other Heterocotylinae mainly by the number and morphology of haptoral dorsal structures, arrangement and number of the anterior glands and morphology of the penis. M. pteromylaei, along with Heliocotyle kartasi, illustrates the originality of monocotylids gill parasites of Pteromylaeus bovinus.