Geological Society. 493 



being found to contain the same minerals in the western parts of 

 Europe, had been even termed by some, the saliferous system. That 

 the red deposits (red and green) are, however, the true equivalents 

 of our old red sandstone, is demonstrated, not only by order of 

 superposition, but also by the many organic remains which they 

 offer. Fishes are the most distinguishing fossils of this great Rus- 

 sian system, and among these are species (notably the Holoptychius 

 Nobilissimus, Murchison, with the Coccosteus, Diplopterus and Cteno- 

 ptychius of Agassiz), forms which occur in deposits of the same age 

 in Scotland. The fishes are in abundance, and a work, illustrative 

 of them, is now preparing by Professor Asmus, of Dorpat, near which 

 University they abound. The authors have traced these fish-beds 

 for a great distance, occupying several stages in the system, and 

 each stage characterized by peculiar species of ichthyolites. 



The zoological contents of this system are also of great value in 

 illustrating and confirming the palaeozoic classification proposed by 

 Messrs. Sedgwick, Murchison and Lonsdale ; or in other words, the 

 evidences found in Russia leave no doubt that the old red and De- 

 vonian systems of rocks are identical. The Orthis subfusiformis, 0. 

 striata, Spirifer calcarata, S. trapezoidalis, Productus caperatus, Te- 

 rebratula prisca (large var.), and Serpula omphaloides, shells distinct 

 from those of the carboniferous system, but similar to those which 

 occur in Devonshire, Westphalia, Belgium, and other places (in de- 

 posits which have been shown by these authors to be of the age of 

 the old red sandstone), are found in Russia in the same beds with the 

 fossil fishes of the old red sandstone of the British Isles. 



Still more striking, observe the authors, are these cumulative 

 proofs, when it is stated, that although in France and Germany 

 there are scarcely any lithological equivalents for the British old red 

 system, yet, that in extending researches far to the east, this mem- 

 ber of the series is found to resume very many of the same mineral 

 characters which distinguish it in the central and northern parts of 

 the British Isles ; and then under similar conditions it contains the 

 ichthyolites of the British deposits. 



3. Carboniferous System. — In the northern regions of Russia, the 

 lower or calcareous part only of the carboniferous system exists, 

 which in the Waldai Hills, near Wytegra, on the Onega, and in 

 many other places, is seen to overlie the old red sandstone. The 

 inferior beds consist of incoherent sandstones and bituminous shale, 

 which sometimes contain thin beds of impure pyritous coal, and im- 

 pressions of several plants well known in the carboniferous system 

 of our own islands. These are surmounted by various bands of 

 limestone, the lowest of which only have occasionally some minera- 

 logical resemblance to the mountain limestone of Western Europe ; 

 other beds being lithologically undistinguishable from the magne- 

 sian limestone of England ; some from a pisolite ; a third and very 

 prevalent band of considerable thickness is milk-white, and not more 

 compact than the calcaire grossier of Paris. This white Productus 

 limestone was traced by the authors from the neighbourhood of 

 Moscow to beyond Archangel (and they ascertained that it ranged 



