35 



The inference appears tx) the author irresistible, that the Bardie- 

 house limestone is of fresh-water origin. The neighbouring moun- 

 tain limestone abounds in corallines, encrinites, and shells, all evi- 

 dently marine. These are in vain sought for in the limestone of 

 Burdiehouse; which, on the other hand, presents the remains of 

 Fishes apparently inhabiting fresh-water, and of Ferns, Lycopo- 

 diaceous plants, and such aquatic vegetables as flourish most among 

 fresh-water lakes and marshes. Tliis limestone, then, is the memo- 

 rial of some inland fresh-water lake or tank, within the waters of 

 which it was elaborated. 



December 16. 

 Sir HENEY JAEDINE in the Chair. 



The follovdng Donation was presented : — 

 Transactions of the Agricultural and Horticultural Society of India. 

 Vol ii. parts 1 and 2. — From the Society. 



The following communications were read : — 



1. "A General View of the Phenomena displayed in the 

 Neighbourhood of Edinburgh by the Igneous Eocks in 

 their relations with the Secondary Strata ; with reference 

 to a more particular description of the section which has 

 been lately exposed to view on the south side of the Castle 

 Hill." By the Eight Hon. Lord Greenock. 



The author referring, in the introductory part of his paper, to the 

 views taken by Hutton of the structure of the earth's surface around 

 Edinburgh, explained, — That the prevailing rocks are strata of sand- 

 stone and shale of the coal formation, with occasional beds of lime- 

 stone; and interrupted by insulated as well as grouped hUls of igneous 

 origin, rising abruptly through them, — That the latter or trap-rocks, 

 seem in many quarters interstratified -w-ith the former, as if they 

 had burst while in a state of fusion between the strata of the second- 

 ary rocks, — That fragments of the secondary rocks are often seen 

 imbedded in the trap, as if they had been broken away from the 

 strata to which they belonged, and been hurried along by the fused 

 empted mass, — And that the trap-roeks often present very different 

 appearances in the same hills, shewing that they were erupted imder 

 varying circumstances at different periods of time. The author far- 

 ther explained, that the environs of Edinburgh seem to constitute a 

 great basin, surrounded by trap-rocks, which dip outwards in all 



