Page:The Zoologist, 4th series, vol 3 (1899).djvu/558

528 contents are printed either in the English, German, or French languages. Among much that is both interesting and valuable may be found an article by Dr. Einar Lönnberg, of Sweden, on "A short comparison between the Capsian and the Baltic Seas." In the first, animal life is much richer than in the second, and we are given a summary of the principal features of the faunas of these seas.

"Passing on to draw an incomplete sketch of the fauna of these seas, I think, we can omit the Seals, three species in the Baltic and one (of northern origin) in the Caspian Sea, although they are destructive to the fish. The fish-fauna has many characteristics in common. Firstly we see a whole lot of freshwater fishes being common to both seas. Nearly all the Baltic freshwater fishes are also found in the Caspian Sea, but the latter is inhabited by a great number of very important foodfishes which are entirely wanting in the Baltic. Among those I think the Belorybitza (Luciotratta), the different species of Sturgeons and the Caspian Pikeperch (Stizostedium caspium) must be ranked first, not forgetting the Caspian Herrings and others. The Baltic has, in addition to its freshwater fishes, some marine fishes which may have entered through the Sound and the Belts, but of these the Plaice and Turbot are of commercial value only in the southern parts, the Flounder up to the neighbourhood of Stockholm, but the Cod still further north to the islands Ulföarne near Hernösand, although of less importance north of Aaland. The Baltic Herring yields the largest quantities and the anadromous Salmon and katadromous Eel are the best paid fishes in the market. Among the fishes which belong to the Baltic relict fauna, only Cottus quadricornis is used for food, but of course being a small fish it is of little value. The fishes of the Caspian Sea seem mostly to belong to the freshwater fauna or to that of brackish water; true marine types are scarce. The Belorybitza being closely related to the "White Salmon" of the Arctic Sea, seems to point to a northern origin, as do the Caspian Seal and some of the lower animals. The Sturgeons are also, at least partly, inhabitants of the Black Sea. But the Mediterranean fauna, which has taken possession of the Black Sea, does not seem to have been able to enter the Caspian Sea." Comparisons of the lower animals are of "great interest, because they show (as is also done by many species of fish) that hardy forms can endure to live and thrive well both in the Caspian and the Baltic Sea, in spite of all differences between these seas. But it must not be forgotten that the greatest part of the Caspian fauna is endemic and characteristic, for that region and the lower fauna of the Baltic is partly hardy marine forms which mostly have entered through the sounds in the south-west, although some are relict forms, and partly freshwater species."