On the Silurian Bocks of Bohemia. 67 



years of researches in England and Wales, I established the 

 Silurian system as a true natural " terrain," which, charac- 

 terised by peculiar organic remains, is separated from the 

 mountain limestone above it, by the great deposit of the old 

 red sandstone. This first step was the prelude to the sub- 

 sequent labours of Professor Sedgwick, M. Landale, and my- 

 self, whereby the " Devonian system " of fossiliferous lime- 

 stones, schists, sandstones, &c., was shewn to be the equiva- 

 lent of the old red sandstone. In this manner the relations 

 of the older series of fossiliferous strata having been unra- 

 velled, the next step was to apply this basis of classification 

 as exhibited in Britain to Europe and other countries, and 

 see how it would there stand the test. You know the part I 

 have borne in carrying out this project; and I only allude to 

 it to inform you, that it was on my return from Poland and 

 Silesia in 1843, whilst I was making certain additions to tlie 

 work on Russia, that I next visited Prague, and then, for 

 tlie first time, became really convinced of t!ie fact, that to 

 whatever extent the Silurian rocks were to be recognised in 

 Germany (tlie strata beneath the carboniferous limestone of 

 Belgium and Rhenish Prussia chiefly representing the De- 

 vonian system), there could be no doubt that M. Barande 

 had succeeded in demonstrating, that the palteozoic rocks of 

 the tract around Prague were of true Silurian age. He had, 

 in fact, even in 1840 (and immediately after the publication 

 of my classification), communicated to me his opinion, that 

 the Bohemian deposits were of the same age as those I had 

 described and classified. After making an excursion with 

 him to view the order of the limestones and shells, I never 

 shall forget the surprise and delight I felt in seeing the 

 rooms and cabinetsof thisaccomplished private gentleman, ab- 

 solutely loaded with organic remains, nine-tenths of which had 

 certainly never before been laid before geologists ; nor did I 

 hesitate a moment in confirming the conclusions at which 

 M. Barande had already arrived, by comparing his fossils, 

 and the rocks in which they are embedded, with the animal 

 forms and sections of my Silurian system. Since that time, 

 M. Barande further communicated to me, that there existed 



