The freshwater of Australia, New Guinea and some of the neighbouring islands are inhabited by peculiar fishes belonging to the Atherinidae and which are chiefiy distinguished by their compressed elevated form, long second dorsal and anal fins and generally by the presence of strong pungent spines in dorsals, anal and ventrals. The upperjaw is bent and provided with well developed teeth, which more or less extend to its outside. They are generally considered to form a distinct subfamily, the Melanotaeniinae. MAX WEBER (3) was the first to point out their importance from a geographical point of view. He considered them as freshwater-fishes, rarely found in brackish water, for which the sea forms an unpassable barrier. At the time WEBER wrote his paper, the Melanotaeniinae were only known from Australia and New Guinea, two landmasses which certainly have been connected together in recent geological times. His prophecy, that they might occur in the islands near New Guinea, which also have been connected with the larger island, has been prooved to be true later (WEBER 4, DE BEAUFORT 1) and has greatly strengthened his opinion on the distribution of these fishes.