176 Proceedings of the Royal Fhi/siccd Society. 



at the time of their formation. Eeliable geological history 

 only begins with the fossiliferous strata of the Palaeozoic era. 

 From these we learn that in the European area the Archaean 

 rocks of Britain, Scandinavia, and Finland formed, at that 

 time, the most extensive tract of dry land in our part of the 

 world. How far beyond the present limits of Europe that 

 ancient northern land extended, we cannot tell ; but it 

 probably occupied considerable regions which are now 

 submerged in the waters of the Arctic Ocean. , Further 

 south, the continental plateau appears to have been, for 

 the most part, overflowed by a shallow sea, the surface of 

 which was dotted by a few islands of Archaean rocks, occupy- 

 ing the sites of what are now some of the hills of Middle 

 Germany and the Archaean districts of France and the 

 Iberian Peninsula. Archaean rocks occur likewise in Corsica 

 and Sardinia, and again in Turkey, and they also form the 

 nuclei of most of the great European mountain-chains, as the 

 Pyrenees, the Alps, the Carpathians, and the Urals. These 

 areas of crystalline schists may not, it is true, have existed 

 as islands at the beginning of Palaeozoic times, for they were 

 doubtless ridged up by successive elevations at later dates ; 

 but their very presence as mountain-nuclei is sufficient to 

 show that at a very early geological period, the continental 

 plateau could not have been covered by any great depth 

 of sea. We can go further than this, — for all the evidence 

 points to the conclusion that, even so far back as Cambrian 

 times, the dominant features of the present European 

 continent had been, as it were, sketched out. Looked at 

 broadly, that part of the great continental plateau upon 

 which our European lands have been gradually built up 

 may be said to be traversed from west to east by two w^ide 

 depressions, separated by an intervening elevated tract. 

 The former of these depressions corresponds to the great 

 Central Plain which passes through the south of England, 

 north-east of France, and the Low Countries, whence it 

 sweeps through Germany, to expand into the extensive low 

 grounds of central and northern Eussia. The southern 

 depression embraces the maritime tracts of the Mediterranean, 

 and the regions which that sea covers. To these dominant 



