Royal Geological Societij of Ireland. 573 



view, occurred principally in old high-level gravels, at a considerable elevation above 

 the river, which had much deepened its valley since the time of their deposit. At 

 Du Toit's Pan, however, none of the diamonds, nor indeed any of the other stones, 

 showed any signs of wear ; and he considered that at that spot was one of the 

 centres at which diamonds had been found in their original matrix. 



Mr. Daintree stated that in Australia there were agate-bearing beds of amygdaloid 

 greenstone, similar to those in South Africa, and that he had called attention to their 

 existence in the neighbourhood of the Bui-nett river, where since then a diamond of 

 the value of £80 had been discovered. 



Mr. Maskelyne commented on the dissimilarity of the minerals found in the 

 diamond-bearing beds of Brazil from those of Dn Toit's Pan or of South Africa 

 generally. He thought that possibly the minerals described as peridot and spinel 

 might be bronzite and garnet, which, however, came fi'om igneous rocks ; and the 

 remarkable fact was that with them occurred unrolled natrolite and diamonds in an 

 equally unrolled condition, which was suggestive of their having been due to a com- 

 mon origin. 



Mr. Ward gave an account of an examination of some of the rock from Du Toit's 

 Pan, with a view of discovering microscopic diamonds, none of which, however, had 

 been found. 



Prof. Rupert Jones had been equally unsuccessful in the search for minute dia- 

 monds, both in sand fi-ora Du Toit's and in the ocherous gravel from Klip Drift. He 

 pointed out the water-worn condition of the agate from Du Toit's Pan, which showed 

 aqueous action, though there were also several other minerals present in a perfectly 

 fresh and unrolled condition. He thought a careful examination of the constituent 

 parts of the gravel might ultimately tbrow light on their origin. That fluviatile 

 action was sufficient to account for their presence had already been shown by Dr. 

 Eubidge and others, who had treated of the grand plateaux and denudations of the 

 district under notice. 



n. EoTAL GrBOLOGicAL SociETY OF Ibeland. — This Society met 

 on the evening of Wednesday, November Sth, 1871. Edward Hull, 

 Esq., F.E.S., Director of the Irish branch of the Geological Survey, 

 in the Chair. 



Dr. Frazer exhibited some diamonds from the South African fields. 



Mr. G. H. Kinahan, M.E.I.A., of the Geological Survey, read a 

 short paper on the Coal-measures of Ireland. This communication 

 was a reply to a statement made before the Society in January last 

 in a paper, " On the Bally castle Coal-field," by Mr. E. Hull, 

 in which it was asserted that there were true Coal-measures in 

 Connaught, while none exist in the provinces of Munster or Leinster, 

 as laid down in the Geological Maps published under the direction 

 of the late Mr. J. B. Jakes. The author of this paper showed that 

 the Coal-measures of Leinster, Munster, and Connaught were 

 identical ; therefore, if Mr. Hull's statement respecting Connaught 

 was correct, his assertion as to Munster and Leinster must be 

 wrong. He pointed out that the late Mr. Foot and himself wished 

 to divide the Goal-measures into four series, but that the late Mr. 

 Jukes objected, and stated, " If we were to seek to force this Coal- 

 measure series into a strict analogy with those of other districts, we 

 might look upon these lower black shales with marine fossils as the 

 representative of the upper limestone shale of Derbyshire ; and 

 the set of sandstones and flagstones No. 2 as the representative 

 of the Millstone Grit of that county. It would, however, be 

 impossible in the South of Ireland to draw any recognizable boundary 

 subdividing the Coal-measure series, and the attempt would, there- 



