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On the Fresh-water Limestone of Burdiehouse in the neighbour- 

 hood of Edinburgh, belonging to the Carboniferous Group of 

 Rocks. With Supplementary Notes on other Fresh-water 

 Limestones. By Samuel Hibbert, M. D., F. R. S. Ed., &c. 

 &c. 



(Read December 2. 1833, February 17, April 21, and December 1, 1834.) 



INTRODUCTION. 



I propose in this memoir to methodically connect several 

 desultory notices, which I had occasion to read during the last 

 session of the Royal Society's meetings, relative to the Lime- 

 stones of fresh-water origin in the neighbourhood of Edinburgh, 

 belonging to the carboniferous group of rocks, and to the organic 

 remains which they contain. 



Hitherto, the limestones belonging to this older class of de- 

 posits have been considered as exclusively of marine origin. I 

 had long since, however, been prepared to expect that a lime- 

 stone of a fluviatile or fresh-water origin would, some time or 

 other, be proved to exist. For, in judging from analogy, it would 

 be unreasonable to presume, that, when fresh-water limestones 

 appear in the rocks of every later epoch, they should meet with 

 an exclusion in the carboniferous group. In entertaining, there- 

 fore, less confined views, I was not at all surprised to find them 

 confirmed in a limestone near Edinburgh, which lately came under 

 my examination, — I allude to that of Burdiehouse. It enclosed 

 none of the marine shells, corallines, or encrinites to be found in 

 the other limestones of the vicinity, but contained in the place 

 of them, and in the greatest possible abundance, the various 

 plants observable in our coal-fields. I also procured from it 



VOL. XIII. PART I. Y 



