THE LAUEENTIAN ROCKS. 25 



separately recognised ; but from Mr. McCulloch's description, 

 as well as from the specimens collected by him, and now in 

 the Museum of the Geological Society of London, it can 

 scarcely be doubted that the Labrador series occurs in Skye. 

 The labradorite and hypersthene rocks from that island are 

 identical with those of the Labrador series in Canada and New 

 York, and unlike those of any formation at any other known 

 horizon. This resemblance did not escape the notice of Em- 

 mons, who, in his description of the Adirondack Mountains, 

 referred these rocks to the hypersthene rock of McCulloch, 

 although these observers, on the opposite sides of the Atlantic, 

 looked upon them as unstratified. In the Canadian Natwralist 

 for 1862, Mr. Thomas Macfarlane, for some time resident in 

 Norway, and now in Canada, drew attention to the striking 

 resemblance between the Norwegian primitive gneiss forma- 

 tion, as described by Naumann and Keilhau, and observed by 

 himself, and the Laurentian, including the Labrador group ; 

 and the equally remarkable similarity of the lower part of the 

 primitive slate formation to the Huronian series, which is a 

 third Canadian group. These primitive series attain a great 

 thickness in the north of Europe, and constitute the main 

 features of Scandinavian geology. 



" In Bavaria and Bohemia there is an ancient gneissic series. 

 After the labours in Scotland, by which he was the first to 

 establish a Laurentian equivalent in the British Isles, Sir 

 Roderick Murchison, turning his attention to this central 

 European mass, placed it on the same horizon. These rocks, 

 underlying Barrande's Primordial zone, with a great develop- 

 ment of intervening clay-slate, extend southward in breadth 

 to the banks of the Danube, with a prevailing dip towards the 

 Silurian strata. They had previously been studied by Giimbel 

 and Crejci, who divided them into an older reddish gneiss and 

 a newer grey gneiss. But, on the Danube, the mass which is 

 furthest removed from the Silurian rocks being a grey gneiss, 

 Giimbel and Crejci account for its presence by an inverted 

 fold in the strata ; while Sir Roderick places this at the base, 

 and regards the whole as a single series, in the normal funda- 

 mental position of the Laurentian of Scotland and of Canada. 



