COMPARISON WITH PENNSYLVANIA, ETC. 143 



(3.) Any one who has carefully compared the coal measures of the 

 Joggins with those of Wallace ami Pictou, must be convinced of the 

 hopelessness of comparing individual beds, even at this comparatively 

 small distance. A fortiori detailed comparisons with Pennsylvania 

 and more distant localities must fail. 



(4.) I do not think that any previous observer has supposed that 

 the coal measures of Eastern Cape Breton represent the whole of the 

 coal formation of Nova Scotia. The " Upper Coal measures" of my 

 papers on Nova Scotia arc certainly wanting, and probably the 

 Sydney Coal-field exhibits no beds higher than No. 4 of Logan's 

 Joggins section. 



(5.) The whole of the coal-beds in the Joggins section belong to 

 the Upper and Middle coal measures. It is quite incorrect to iden- 

 tify No. 6 of Logan's section with the Lower Coal measures. These 

 do not occur at the Joggins, but are found in Nova Scotia, as in 

 Virginia and Southern Pennsylvania, at the base of the system, under 

 the marine limestones. The Albert beds are the equivalents of these 

 lower measures, and not of the Pictou eoal. In my paper on the 

 Lower Carboniferous coal measures (Journal of Geological Society of 

 London, 1858), will be found a summary of the structure of the 

 Lower Coal measures, as shown at Ilorton Bluff, and elsewhere. The 

 term "true coal measures," quoted by Mr. Lesley, does not mean in 

 my description the Middle Coal measures, but merely that part of 

 them holding the workable coal-seams. 



(6.) Whatever may be the value of M. Lesquereux's applications 

 of the fossil flora to the identification of coal-seams in the West, I am 

 prepared to state, as the result of an extensive series of observations, 

 still for the most part unpublished, that in Nova Scotia the flora is 

 identical throughout the whole enormous thickness of the Middle coal 

 measures, and that the differences observable between different seams 

 are attributable rather to difference of station and conditions of 

 preservation than to lapse of time. It is indeed true, as I have 

 elsewhere explained, that the assemblages of species in the Lower, 

 Middle, and Upper Coal measures may be distinguished ; but within 

 these groups the differences are purely local, and afford no means for 

 the identification of beds in distant places. 



(7.) I do not desire to offer any opinion on the questions raised by 

 some American geologists as to the extension of the term Carboniferous 

 to the Chemung group ; but I know as certain facts, that the flora of 

 the Lower Coal measures, under the marine limestones and gypsums 

 of Nova Scotia, is wholly Carboniferous, and that the flora, on which 

 alone I consider myself competent to decide, of the Chemung of New 



