310 ANNUAL OF SCIENTIFIC DISCOVERY. 



greater number of species has been found in its coal measm-cs. Thus the 

 predominance of typical or distinctly characterized forms belongs to our 

 country. By comparison of the flora of our epoch on both continents, we 

 find now the same proportional relation and difference as at the time of the 

 coal formation, that is, on this side of the Atlantic a predominance of well- 

 marked types; a predominance of species of trees; 1 a number of species 

 perfectly identical on both continents, and many American species so nearly 

 related to European congeners that their specific characters can hardly be 

 established. 



Though further researches ought necessarily to increase the number of 

 species of fossil plants belonging to our coal measures, the proportional 

 difference is likely to remain as it is established above. 



The fossil flora appears identical at the same geological horizon over the 

 whole extent of our coal-fields. This proves uniformity of stratification 

 and geological unity of the different coal basins of America. 



The first trace of vegetable terrestrial life appears in the middle of the 

 Devonian in a species of Lepidodendron, represented by its bark, its leaves, 

 its cones, and large trunks of silicificd wood. Xo remains of any other 

 form of terrestrial vegetation have been seen in strata either inferior or con- 

 temporaneous to this. All the vegetable remains known in the Silurian and 

 lower Devonian belong to species of fucoides or marine plants, mosth" of 

 small size, resembling some species of Fucus of our time. The first leafy 

 terrestrial plants appear in the Old Red sandstone. All the representatives 

 of this new vegetation belong to a peculiar genus, Noygeratliia Gopp., more 

 related to Conifers or even to Palms than to Ferns. They are found in the 

 same geological horizon, both in Europe and in America, and entirely dis- 

 appear at or before the beginning of the coal epoch. Leo Lesquereux, Silli- 

 man's Journal, Nov. I860. 



INTERESTING GEOLOGICAL SPECULATION. 



The late Professor Edward Forbes, in his work on the Xatural History of 

 the European Seas (which was left uncompleted at his death five years ago, 

 and which has been completed, and published during the past year, by Rob- 

 ert Godwin Austen, F. R. S.), gives a curious and interesting instance of 

 the method by which zoological studies may be brought to bear upon the 

 facts of geology. The fauna of Vigo Bay, an arm of the sea which extends 

 inland some sixteen or eighteen miles on the northwestern coast of Spain, is 

 found by Mr. M'Andrew to be far more nearly related to that of the British 

 seas than to that of the region in which it is situated. Now, it had already 

 been noticed by Professor Forbes, some years ago, that the flora of the west- 

 ern coast of Ireland was in many instances identical with that of the Astu- 

 rias on the northwestern coast of the Spanish Peninsula. We cannot suppose 

 that the seeds of these Spanish plants Avere conveyed to Ireland by Rennel's 

 current, for in that case traces of them would also be found in the south- 

 western counties of England, which is not the case; nor that they were con- 

 veyed by the winds, for the plants which are common to the two countries 

 are precisely those whose seeds are not well adapted for such diffusion. In 

 order, therefore, to account for this singular identity between the floras of 



1 The distribution of the genus Lepidodendron, at the time of the formation of 

 tlse coal, has some analogy with that of the oak in our time. 



