Catalogue of the Fresh-water Fishes of Africa in the British Museum (Natural History)

Abstract

THE British Museum has recently published the fourth volume of Mr. G. A. Boulenger's “Catalogue of the Fresh-water Fishes of Africa;” Thus is brought to a conclusion—at any rate, for some years to come—a work of very great value. Mr. Boulenger's research into the ichthyology of the African rivers and lakes has gone far beyond a mere catalogue of species. It began to attract attention nearly twelve years ago by the light that it threw on the past geological history of Africa, the former superficies of this continent at different times in regard to rising and falling levels of land, the connections of the continent with outlying islands, the desiccation or the flooding of great areas of land in, the interior, the increase or the restriction of river basins and of lake limits. Briefly summarised, it went to show that the Nile system in past times has been in direct communication with the now isolated Lake Rudolf, and has come very near to the Chad Basin, which again has communicated intermittently with the Niger, while the Niger or its upper portion may at one. time have had an outlet into the Atlantic in common with the Senegal, and have been separable by only a few miles of land from the upper waters of the Gambia, the Volta, and of all those streams that flow from north to south through the forests of Guinea and the Gold Coast into the great African Bight. On the other hand, it showed a comparative poverty and isolation in fish fauna of the Zambezi Basin and South Africa; and it illustrated, above all, the specialised character and wealth in fish-fauna of the Congo Basin. This region (with which Tanganyika was not always connected) must have approached very closely to the upper waters of the Gaboon and Cameroons rivers to account for the near relationship between their fish-fauna and that of the Congo Basin. Catalogue of the Fresh-water Fishes of Africa in the British Museum (Natural History). Vol. iv. By Dr. G. A. Boulenger. Pp. xxvii + 392. (London: British Museum (Natural History), and Longmans, Green and Co., 1916.) Price 30s.