500 



THE GEOLOGIST. 



"Noy!-. alrhoueh the Arbroitli pwing- stoue. aud the grey rocks ranging to the 

 noith of Dundee. muc:i resemble the uppermost Ludlow rock, they contain the 

 Cephalaspis Lyellii. and if. therefore, classed with the Devonian rocks, they must, 

 under every c'ircumsrance. be viewed as the very base of that natural group. It 

 follows, therefore, tli-u certain conglomerates on the flanks of the Grampians, 

 whicli iii. lvi lie all those grey rocks with Pterygoti and Cephalaspis, can no longer 

 be unit : 1 ;i; they have been vrith the Old Eed or Devonian, hut must represent 

 some portion of the Silurian system. In speaking of the lowest member of the 

 Old Ilei Suidstone. as characterised by the Cephalaspis Lyellii, the author ex- 

 pressed his conviction, that in the north-eastern Higlilands and Caithness the zone 

 is represented by the vast thickness of thin-bedded red sandstone and conglomerates, 

 which had been already adverted to as lying beneath the Caithness flags. 



The author, who had recently visited Dura Den. in Fifeshire. in the company 

 of Lord Kinnaird and the Rev Dr. John Anderson, whose work on that beautiful 

 tract is we'l known to geologists, declared that there cr^uld be no doubt whatever 

 that the yeilow sandstones of Fife pertain truly to the Old Eed group, are entirely 

 suloacent to the hwe^t cnrboniferous sandstones, and are of the same age as the 

 upper yellow sandstones o: Elgin. A drawing, prepared by Lady Kinnaird (the 

 splendid specimen being in the museum at Eossie Priory), of the fossil fish Holo- 

 ptychius nobilissimus. nearly three feet in length, which was found on the occasion 

 of this visit on the property of l\Irs. Dalgliesh, was exhibited ; and as this species 

 abounds in the lower and red portions of the deposit, and also occurs in the over- 

 lying yellow sandstones, associated with Holoptychius Anderson! and H. Flemingii 

 of the latter, the age of the deposit is clearly substantiated. In conclusion, Sir 

 Eoderick said that this communication must only be considered as a rehearsal of 

 what was to be done with more eifect nest year at Aberdeen, vrhen further obser- 

 Tations migh . lead him either to confirm or modify some portion of his views. In 

 the meantime, the great fundamental reform of the North Scottish series, proving 

 the ascent from rocks on the west coast, which are unquestionably older than any 

 in England and Wales, to the much younger " Old Eed Sandstone" of the east 

 coast, is firmly established. 



The communication was illustrated by several geological maps, including an old 

 one coloured by himself 31 years ago, the maps of M'CuUoch, Nicol, and Knipe, 

 and a map of .Sutherland which the author coloured this summer. Besides large 

 diagrams, there were sketches of the west coast of Sutherland by Miss Charlotte 

 Dempster. 



YiT. Page also communicated a paper on Scottish Geology, under the title of 



The Relations of the Metamorphic and Older Palgeozoic Rocks of Scotland." 



L'uder the same head. Dr. Anderson made a communication " On the Fossils 

 and Yellow Sandstones of Dura Den."' This interesting paper led to considerable 

 discussion, of which we can only give a very abridged account. 



Dr. Anderson said — " I shall only say a very few things, and that as briefly as 

 possible. Sir Roderick Murchison began his lucid and elaborate statement by a 

 reference to Cape Wrath, where, after a day of geological toil, he slept, I doubt 

 not, soundly, in what IMaculloch describes 'as the land's end of Scotland's wildest 

 region, the advance! post of Scotland's wildest seas.' I shall now conduct you to 

 the quiet scenes of the south, where, in the terms of classic mythology, the vale of 

 Ceres, late"y oovorel with the sol len fruitage of autumn, terminated the fossil- 

 ifer-jus > L-i >:-it he was u-y~ to doscribe. I am relieved, however, of much of my 

 task respj/tinz ' 1; 't tliis deposit in the series, inconsequence of what 

 had been \ -y Sir 11; l-.-riek. who declares it now, as he did when he formerly 

 visited the spot, to '. o lafrjber of the true Old Red Sandstone, and to have no 

 geological connection vriro trr? Carboniferous system above ; and I am happy also 

 to say that I have n:> . : pp inerit upon this point seriously now to contend against, 

 nor to be confronted by any Professor Nicol called upon to unlearn the lessons 

 which 1 myself had taught him. Much error, however, still prevails regarding 

 the Yellow Sandstone, both as to its true mineralogical characters and its 

 geognostic relations. In Ireland, it seems to be utterly misunderstood by Sir 

 Hichard Griffith, who, in his comaiuuic ition to this section last year at Dublin, 



