American Association. 263 



the geological series, of tliose great masses of crystalline or sub- 

 crystalline stratified rocks, in the North Highlands of Scotland, in 

 some of which organic remains were discovered by Mr. Charles 

 Peach, ia 1855? 



That discovery induced me, in the same year, to re-visit the lo- 

 calities in the north-west part of Sutherlandshire, to the east of 

 Cape Wrath(Durness), in which the fossils had been detected ; my 

 chief object being to ascertain if the views of former explorers of 

 that region, including Sedgwick and myself, in 1827, were correct ; 

 viz., that these cpartz rocks and limestones, associated with mica 

 schist and a sort of gneiss, are of a more ancient date than the great 

 series of Old Eed Sandstone, or Devonian deposits, that occupy so 

 large a portion of the north-east of Scotland, and are particularly 

 developed in Caithness and the Orkney Islands, 



The results arrived at in that excursion, in which I was ac- 

 companied by Prof. James Nicol, were communicated at the 

 meeting of the British Association at Glasgow, in September, 1855, 

 and published in the volume of that year — (See Transactions of 

 the Sections, 1855, p. 85). I then re-affirmed the opinions I had 

 formed in the year 1827, in company with Professor Sedgwick, as 

 to the anteriority of all these quartz rocks with intercalated lime- 

 stones, to the Old Red Sandstone, or Devonian System; and judg- 

 ing from the facts that such ci-ystalline and sub-crystalline strata 

 reposed unconformably upon an ancient granitoidal gneiss, and 

 were flanked and surmounted by the ichthyolitic deposits of 

 Caithness, I expressed my belief that, although very imperfect 

 and difficult of absolute determination, the fossils there found by 

 Mr. Peach were of Lower Silurian age. 



At that time, my eminent and lamented friend, the late Hugh 

 Miller, had suggested theoretically that the quartzites and lime- 

 stones of the K'orth Western Highlands might prove to be the 

 metamorphosed equivalents of the Old Eed series of the East 

 Coast ; and, subsequently. Prof. jSTicol has even endeavored to 

 show that these rocks may be the metamorphosed representatives 

 of the carboniferous series of the South of Scotland ! Both these 

 suggestions were of course opposed to my own belief, and as they 

 have been put forth by distinguished contemporaries, I have now 

 to show how my own views have been sustained. 



Within these few weeks, Mr. C. Peach has found, in the same 

 locality, (Durness), other and better preserved fossils, which have, 

 I rejoice to say, set the questio vexata at rest, as will be seen by 



