BUNBURY ON THE COAL FORMATION OF CAPE BRETON. 437 



a large number of tlie Ferns of the "West Indies extend into Brazil, 

 and as far soutli as Rio de Janeiro ; and the details already published 

 by Sir "W. Hooker, in the first volume of his ' Species Filicum/ suf- 

 ficiently prove that the number of Ferns common to the tropical 

 regions of the old and new worlds is much greater than had been 

 generally supposed. 



We may, I think, conclude, that the wide diffusion of the same 

 forms of vegetation through the ancient carboniferous deposits of 

 Europe and America is less extraordinary than it would appear if 

 we neglected to observe the large proportion of Ferns in this ancient 

 vegetation, and their distribution at the present day. If the Lepido- 

 dendra really belonged to the Lycopodium tribe, and were analogous 

 in their constitution to the recent forms of that order, the same con- 

 clusions may be extended to them ; for a great number of the recent 

 Lycopodia are plants very extensively spread over the globe. On this 

 point I need only refer to the valuable observations of Dr. Hooker, 

 in his ' Flora Antarctica.' 



Still, it must be admitted, that the uniformity of this ancient vege- 

 tation over so large an area, — extending from Scotland to Alabama 

 in latitude, and in longitude from Bohemia to the Ohio, — is greater 

 than can be found at the present day ; and I quite agree with Mr. 

 Lyell in believing that this indicates a greater uniformity and equa- 

 bility of climate, depending probably on a different distribution of 

 land and sea. I believe we are fully justified by analogy in saying, 

 that if such continents as Europe and North America had not existed 

 at that period, but in their stead groups of islands, large and small, 

 and if the ocean which now intervenes between the two continents 

 had been thickly studded with such groups, like the Southern Pacific 

 at present, there would have been nothing unnatural or surprising in 

 such a uniformity of vegetation throughout those regions, as we now 

 meet mth in the coal-formation. But I suggest this merely as a 

 hypothesis, which, if admitted, would serve to explain a remarkable 

 fact, and I do not wish to build much upon it ; being aware, as I 

 observed on a former occasion, of the danger of resting a large theory 

 on such uncertain foundations as are supplied by fossil botany, at 

 least in the present state of our knowledge. 

 November 1846. C. J. F. BuNBURY. 



EXPLANATION OF THE PLATES. 

 Plate XXL 



Fig. 1 A. Neuropteris cordata, natural size, exhibiting the position of the small 



basal leaflets relatively to the large one. 

 1 B. Neuropteris cordata, var. angustifolia, natm'al size, with the basal 



leaflets. 

 1 C. N. cordala, natm'al size, with apparent hairs on its surface. 

 1 D. Part of the same, magnified. 

 1 E. Another specimen of the same, with appearances so«xewhat resembling 



fructification. 

 1 F. Part of the above specimen, magnified. 



