DE VERNEUIL AND d'aRCHIAC ON RUSSIAN PALiEOZOIC FOSSILS. 115 



of the globe, and it is only towards the uppermost beds of the Si- 

 lurian series that we first find Ichthyodorulites belonging to the 

 genus Onchus and to other genera of which the family is not yet 

 determined. 



These remains, although found in England, are generally very rare, 

 and analogous fossils have not yet been obtained in Russia. Accord- 

 ing to the present state of knowledge in palaeontology, it seems to 

 have been in the Devonian period that fishes became for the first time 

 considerably developed, and this important point in the history of 

 these animals is fully confirmed by the study of the Russian forma- 

 tions, for no country is richer in the fossil fishes of that period, and 

 none, considering the recent date of investigations of this kind, has 

 furnished greater material for this department of ichthyology. In 

 fact, from the specimens which have been forwarded to him, M. Agas- 

 siz has already been able to determine as many as forty-six Russian 

 species (nearly half the whole number of Devonian fishes actually 

 known), and of these species, eighteen are common to Russia and 

 Scotland and twenty-eight are peculiar to Russia. In the Carboni- 

 ferous system however, we only know of the Ichthyodorulite found 

 by M. Helmersen near Troitzkoje, about thirty wersts to the west 

 of Serpoukhof *, and one tooth which we discovered at the mouth 

 of the Pinega, and which M. Vogt considers as having belonged to 

 a T[\e\Y genus of the Cestraciont family, establishing a passage to 

 Hybodusf. The Permian system has afforded several species found 

 at Kargala near Bielebi and in the grits of the neighbourhood of 

 Perm, but most of them are not yet made out. 



General conclusion, — From our own investigations, it appears that 

 the palaeozoic fauna of Russia, including the Saurians, Fishes, andl 

 all the Invertebrata except the corals, embraces S92 species J; and if 

 we add to these the species quoted by other authors, the total will 

 amount to 560. This number, not one-fifth part of the general pa- 

 laeozoic fauna §, cannot but suggest how much yet reftiains to be done 

 in this vast empire; but however incomplete the list may be that 

 we now offer, it is already capable of furnishing useful material to- 

 wards making out the history of the various epochs of our globe. 

 When it appears that in the case of so important a portion of the 

 earth's surface as is presented by the whole of Europe, we can trace 

 at its two extremities the succession of changes wliich its inhabitants 



* Erm. Arch. 1841, pi. 3. fig. 3. 



t According to M. Vogt, this tooth is characterized hy its single obtuse cone 

 and the large folds of its enamel. It rescml)les the hinder teeth of IlybodiiSj but 

 differs in the absence of an elliptic base and a longitudinal axis. 



X Adding to this number the thirty-eight species of cov;ils determined by 

 Mr. Lonsdale, and several others of which we were not able to bring specimens, we 

 may consider the whole number of S])ecies admitted by us and the result of our 

 own personal investigation to amount to ytxy nearly 440. 



§ In the memoir published by M. dc Verneuil and M. d'Archiac on the fossils 

 of the Rhenish provinces, the whole number of palaeozoic species was stated to 

 be 2700. Since then the number has been increased by the labours of MM. Con- 

 rad, Emmons, J. Hall, Mather and Vanuxem on the state of New York, by tliose 

 of MM. A. and C. Romer on the banks of the Rhine and the Harz, those of AlM, 

 Portlock and M'Coy on Ireland, &c. 



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