with Descriptions of Xw Species of Fossil Pla 



The fact to which reference has just been made, viz.: the 

 occurrence' of Oiiodea s'ensibilis on the Island of Mull, off the 

 "West coast of Scotland, while it has not been found in the Ti - 

 tiary beds of other parts of Europe, is indicative, so far as it 

 goes, not only of an American connection during the Mioc 

 period, but of an American origin for that species, and bo by 

 inference of the other genera and species common tn the two 

 continents during that epoch. 



If this inference should be confirmed by future observation, 

 we should then see that the Eocene tropical or sub-tropical 

 flora of Europe, was crowded oft' the stage by the temperate flora 

 of the Miocene, which, accompanying a depressi n of tempera- 

 ture, had migrated from America, while the Eocene flora re- 

 treated South and East, and is now represented by the living 

 Indo- Australian flora, characterized by its species of Hdk 

 Dryandra, Eucalyptus, &c, which form so conspicuous an 

 element in the Eocene flora of Europe. This theory would 

 account for the presence of these tropical forms in the Lower 

 Miocene of Europe, while so far as yet obtained they are en- 

 tirely absent from the Miocene flora of America*. In Eur 

 a few of the Eocene forms lingered behind in the grand exodus 

 of that flora, and mingled with the more boreal and occidental 

 barbarians by which thecountrv wasoverrun ; while in America 

 those which we now call Asiatic forms never had an exist 

 That this bridge between America and Europe was in :i >• 

 perate climate is proved by the character of the plan*- which 

 passed over it. On referring to a terrestrial globe, it will I 

 that by way of Greenland, Iceland, and the Bebrides, ll 

 no very wide gaps to be spanned ; but a connection by thai 



would carry us so far into the Arctic zone that noi f tin 



which we suppose to have made the journey could have with- 

 stood the cold of the climate had it been the same ae at present. 

 We have conclusive evidence, however, that it 

 on Mackenzie's River, Disco Island, on Iceland and tie dof 



Mull, we have, in the recurrence of part.- of the very t' 



