482 FLORA OF THE CARBONIFEROUS PERIOD. 



certain extent, distinct in their flora. Any minor differences which 

 exist in subordination to these main divisions, will be fully detail- 

 ed in the memoir on the coal beds of the Joggins already refer- 

 red to. 



I have included in the list such plants from New Brunswick 

 as are known to me. Those from Grand Lake in that Province 

 are I believe on the horizon of the middle coal formation, though 

 tending to the upper. A collection formed by Sir W. E. Logan 

 atBaie de Chaleur, in beds of the lower and probably middle coal 

 formation, includes also some species which in Nova Scotia are 

 more characteristic of the upper coal formation. This apparent 

 mixture of plants of different horizons, may be a consequence of 

 the comparatively small thickness of the New Brunswick coal 

 formation. 



In the present unsettled state of the species of coal plants, it is 

 with much diffidence that I venture to publish this list, which 

 •will without doubt admit of many corrections and improve- 

 ments, even in the memoir on the formation of the Nova Scotia 

 coals, with which I propose to follow it. I have, however, en- 

 deavoured to avoid adding to the load of synonyms, and have in 

 all doubtful cases leaned to the side of identity with known species 

 rather than to that of giving new names. I may add, that the 

 increase of my collection has enabled me to reunite many speci- 

 mens which I had regarded as representatives of distinct species. 

 But for the large number of specimens which I have been enabled 

 to examine, I should certainly in the case of several variable 

 species, as for example Alethopteris lonchitica and Lepidodendron 

 corrugatum, have erred in this way. I am constantly more and 

 more convinced that no satisfactory progress can be made in fossil 

 botany without studying the plants as they occur in the beds in 

 which they are found, or in large numbers of specimens collected 

 from those beds, so as to ascertain the relation of their parts to 

 each other. 



Dadoxylon, linger. 



Large quantities of drifted coniferous trunks are found in the 

 sandstones of the coal formation in Nova Scotia; but, after shoe- 

 ing more than one hundred specimens, the following are the only 

 species I can distinguish. It is to be observed, however, that the 

 different states of preservation of these trunks render their study 

 and comparison very difficult. 



