THE CARBONIFEROUS. 43 



have been stated by Mr Robb, which would tend to diminish some- 

 what the probable importance of the lower beds of coal underlying those 

 worked at Glace Bay and Cow Bay. These, however, include the 

 equivalents of the Gardiner seam and the M'Gillivray seams. To 

 these points I may add the statement that in my sketch map, page 

 413, the strike of the beds at the east side of Sydney Harbour should 

 turn a little more to the south, and that the outcrops should be closer 

 to each other ; and that, by an error in the engraving, the town of 

 Sydney is removed from its true position on the southern arm of the 

 harbour to the south-west bar. I am indebted to Mr Mosely of 

 Sydney for information bearing on some of these points. 



In the Reports of the Geological Survey for 1872-3, 1873-4, and 

 1874-5, Mr Robb has gone with great elaborateness into these ques- 

 tions, and correlates the Sydney main seam not only with the Boss 

 or Victoria, but with the David's Head scam of Bridgport, the Har- 

 bour seam of (Jlace Bay, and the Block-House seam of Cow Bay. 

 Mr R. Brown has stated a similar view of the equivalency of these 

 beds in his work on the Coal-fields of Cape Breton.* 



Leaving these local details, I may now refer to some curious fossil 

 plants met with in the Coal formation of Cape Breton, and deserving 

 of record as additions to our knowledge of its flora. Among the 

 rarest of fossil plants in the Coal rocks of Nova Scotia have hitherto 

 been the trunks of tree-ferns. The scattered fronds are sufficiently 

 abundant, but trunks of arborescent species are seldom found. Mr 

 Poole's collections at Glace Bay enable me to add another fine 

 species to the Coal flora of Nova Scotia. It is a large flattened stem, 

 a foot or more in diameter, marked with many wrinkles over the 

 whole surface, and with large distant oval leaf-scars 1-i- inch in 

 diameter and 3 inches in length, to which large fronds must have 

 been attached. It is a near ally of Caulopteris macrodiscus, Stern- 

 berg, but has larger and more distant scars, more obtuse above. I 

 would name it Caulopteris glacensis. It belongs to the genus 

 Pfychopteris of Corda. Another remarkable trunk, which I found 

 obscurely preserved in coarse sandstone at North Sydney, appears 

 different from anything hitherto described. It seems to have had 

 four vertical rows of scars, the form of which could not be made out ; 

 but I have little doubt that it belonged to an arborescent fern with 

 a stem 4 inches in diameter and several feet at least in height. 

 Near an abandoned coal-mine at Bridgeport I also found a fragment of 

 one of those tree-ferns surrounded with aerial roots, to which the name 

 Fsaronius has been given, but not admitting of specific description. 



* London, 1871. 



