HEEPv CAEBOliriFEEOTTS FLOEA. OF BEAR ISLAND. 167 



but probably the siliceous schists, which are greatly developed in the 

 ujDper divisions of the Mountain Limestone, rej)resent the Culm or 

 Millstone -grit. The position of the Eussian-island hmestone, which 

 is widely spread, especially in Spitzbergen, is still doubtful ; for de- 

 terminable fossils are wanting in it ; and the classification of the red 

 shales in the Devonian is by no means certain. But although much 

 still remains doubtful, we can see from clearly estabhshed facts that 

 a remarkable and analogous development must have taken place in 

 South Ireland and in Bear Island, high up in the north, and in the 

 middle of Europe, in the formation of the rocks as well as in the 

 plants and animals contained in them. Therefore the flora of the 

 Ursa stage is of great significance in the history of the earth, as we 

 shall see stiU more clearly if we cast a glance at the position which 

 it holds in the order of the earth's development. 



In the Silurian and Lower Devonian aU the known plants and 

 animals are marine ; and it is not until the Middle and Upper Devo- 

 nian that land-plants, indicating dry land, make their appearance. 

 Yet at present there are only a few localities known to us, which 

 may be designated as Devonian islands : the neighbourhood of 

 Saalfeld, in Thuringia, which belongs to the Upper Devonian, is the 

 only one which has yielded a fairly respectable number of plants ; and 

 even these have been found mostly in small fragments, which pro- 

 bably may have been divided into too many species. Towards the 

 end of the Devonian period the dry land increases rapidly in the 

 northern hemisphere ; it must have been a time of rising of the bed 

 of the sea. AVith this great formation of dry land begins a new 

 epoch — the Carboniferous. The first division of this I have caUed 

 the Ursa stage. With it came in the first rich land-flora, which 

 can be traced in the northern hemisphere, both of the Old and 

 New World, from 47° to 74° and 76° K. lat. Everywhere it exhi- 

 bits the same character ; everywhere appear Calamites radiatus 

 (which probably clothed the marshy low country with its long 

 column-like stems), the branching Lejndodendron, thickly clothed 

 with leaves, and the curious Knorria. Even the Gyclostigmata, 

 with which we have become acquainted in Ireland and Bear Island, 

 were probably not wanting in dry-land formations lying between 

 them, and formed part of the woods under whose shade the species 

 of Cardiopteris and Pcdceopteris spread out their powerful fronds. 



This flora already comprises such a remarkable number of species, 

 many of which appear in such widely distant regions, that it seems 

 to indicate a wide-spread continent Avhich was situated in the 

 temperate as well as in the arctic zone. The coal-lands of Russia 

 reached perhaps as far as Bear Island, the plants of which would then 

 represent the most northern off'shoots of the Russian Lower-Carboni- 

 ferous flora. That the Ursa stage must have belonged to a land 

 of considerable extent is shown by the freshwater animals found in it, 

 the great pond-mussels (Anodonta) and the insects (all Neuroptera), 

 They could only have lived in a land large enough to give rise to 

 lakes and rivers. 



It is difiicult to decide how long this state of things lasted. Then 



IT 2 



