ADDRESS. 15 



continent of Europe. These are exclusively of a marine character, wliile 

 the remainder corresponds to the Old Red Sandstone of Wales, England, 

 and Scotland. 



At Tchudora, about 105 miles S.E. of St. Petersburg, the lowest 

 members of the series consist of flag-like compact limestones accumulated 

 in a tranquil sea and containing fucoids and encrinites, together mth 

 shells of Devonian age, such as Spirifers, Terebratulce, Orthis, Lepteenas, 

 Avicula, Modiola, Natica, Bellerophon, &c., while the upper division 

 gi'aduates into the Carboniferous series as it often does in Britain, and, like 

 the Old Red Sandstone of Scotland, contains only fish-remains, and in 

 both countries they are of the same species. ' Proceeding from the 

 Valdai Hills on the north,' the geologist ' quits a Devonian Zone with a 

 true " Old Bed" type dipping under the Carboniferous rocks of Moscow, 

 and having passed through the latter, he finds himself suddenly in a 

 yellow-coloured region, entirely dissimilar in structure to what he had 

 seen in any of the northern governments, which, of a different type as 

 regards fossils, is the true stratigraphical equivalent of the Old Bed system.' 

 This seems to me, as regards the Russian strata, to mean, that just as the 

 Devonian strata of Devonshire are the true equivalents of the Old Red 

 Sandstone of Wales and Scotland, they were deposited under very different 

 conditions, the first in the sea and the others in inland fresh-water lakes. 

 At the time Sir Roderick Murchison's work was completed, the 'almost 

 universal opinion was that the Old Red Sandstone was a marine forma- 

 tion. In the year 1830, the Rev. Dr. Fleming, of Edinburgh, read a 

 paper before the Wernerian Society in which he boldly stated that the 

 ' Old Bed Sandstone is a fresh-water formation ' of older date than the 

 Carboniferous Limestone. This statement, however, seems to have made 

 no impression on geologists till it was revived by Godwin-Austen in 

 a memoir ' On the Extension of the Coal-measures,' &c., in the Journal 

 of the Geological Society, 1856. Even this made no converts to what 

 was then considered a heretical opinion. I have long held Dr, Fleming's 

 view, and unfortunately published it in the third edition of ' The Physical 

 Geology and Geography of Great Britain,' without at the time being 

 aware that I had been forestalled by Dr. Fleming and Mr. Godwin- 

 Austen. 



To give anything like a detailed account of all the fresh- water forma- 

 tions deposited in estuaries and lakes from the close of the Old Red 

 Sandstone times down to late Tertiary epochs, is only fitted for a manual 

 of geology, and would too much expand this address ; and I will therefore 

 give little more than a catalogue of these deposits in ascending order. 



In the Coal-measure parts of the Carboniferous series, a great propor- 

 tion of the shales and sandstones are of fresh-water origin. This is proved 

 all over the British Islands by the shells they contain, while here and there 

 marine interstratifi cations occur, generally of no great thickness. There 

 is no doubt among geologists that these Coal-measure strata were chiefly 



