1871.] HARKNESS AJTD HICKS ST. DAVId's PROMONTORY. 403 



fended the Survey nomenclature by reference to the then received 

 definition of Syenite and Grreenstone, terms still imperfectly understood 

 and applicable to the main mass of the rocks in question, though 

 possibly subsequent closer examination and new sections may have 

 rendered some modification of the boundary line desirable. He was 

 prepared to allow the metamorphic origin of all rocks of the classes 

 under consideration, but did not think there was sufficient evidence 

 to show that the divisional planes in the Syenite and Greenstone of St, 

 David's were due to original stratification ; but they might correspond 

 rather to the great joints of most granites. Mr. Hughes pointed 

 out that the conglomerate contained fragments of the hornstone and 

 quartz of this older series, which he considered was probably part of 

 an old ridge or shoal, possibly of Laurentian, but certainly of Pre- 

 Cambrian age, and thought that there were slight differences in the 

 Hthological character of the beds on either side, such as might be 

 explained on this supposition. He agreed with Prof. Ramsay in 

 thinking that there was evidence of the proximity of land in early 

 Cambrian times, but was not prepared to refer these red rocks to 

 inland seas or lakes as opposed to open sea ; the whole seemed rather 

 the deposit of an open sea encroaching during submergence. He 

 did not attach very much importance to the restriction of genera to 

 limited horizons in these older rocks of St. David's ; for, as it 

 was reserved for Mr. Hicks to discover these fossils after so many 

 other observers had examined the district, he anticipated that 

 further researches must certainly result in finding links which will 

 connect together more closely beds the stratigraphical relations 

 of which seem to indicate so clearly an unbroken though varying 

 series. 



Mr. GwYif Jefpreys had been struck by the intercalation of non- 

 fossihferous beds from time to time among the fossiliferous beds 

 described in the paper. Beds now in course of formation contained 

 also very few, if any, organisms, apparently in consequence of the 

 great deposits of mud brought down by rivers and redeposited in 

 certain parts of the sea-bed. That this was the case had been 

 proved by recent dredging- operations both in the Atlantic, off the 

 coast. of Spain, and in the Mediterranean. 



Mr. BoYB Dawktsts called attention to the extension of the Mol- 

 luscoida, Annulosa, and MoUusca, deep down in the Cambrian rocks, 

 and yet without any trace of their convergence. The origin of life 

 might be as far removed from that period as was the Cambrian from 

 the present time. The difference in the colours of the rocks he was 

 inclined to refer to the different degrees of oxidation of the iron 

 they contained, which might supervene in a comparatively short 

 time. 



The Eev. W. S. Symoktos had, in visiting the spot, been much 

 struck by the rocks, at that time termed Syenite, which he believed 

 might be an extension of those on the Carnarvonshire peninsula, 

 and which he thought supported the whole series of the Cambrian 

 rocks, so that they might after all be the Laurentian, the same as 



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