Some time ago the Leyden Museum received a small collection of fishes and reptiles from the Congo-Coast, kindly presented by Mr. Kamerman. Among them there were several specimens of Gerres melanopterus which, as is known, was firstly described by Bleeker 1) in his »Mémoire sur les Poissons de la Côte de Guinée” after a single specimen, collected by Mr. Pel, the late Dutch Governor of the Coast of Guinea. In that paper Bleeker also gives a description and figure of another species of that genus, G. octactis, based upon a single specimen, from the same locality. A third species from the West-Coast of Africa previously had been described by Günther under the name G. nigri. Steindachner however in his interesting paper »zur Fischfauna des Senegal” 2) comes to the conclusion that Gerres octactis is not a distinct species, but should be considered as an adult specimen of G. melanopterus. I was happy enough to find Bleeker’s type specimens in our collection, and I had also the opportunity to examine several specimens of G. melanopterus and G. nigri, collected on the Coast of Liberia by Büttikofer and the late Sala. After a careful study I cannot accept Steindachner’s suggestion concerning the identity of the two species above referred to, as I hope to demonstrate in the following lines.