304 Scientific Proceedings, Royal Dublin Society. 



been replaced by others of Permian type, and of more hardy nature, 

 the formations present a mixed or alternating assemblage of a 

 marine Carboniferous fauna, and a terrestrial Permian flora. For 

 the Northern Indian region Dr. Waagen assumes that the Permian 

 fauna migrated with warm currents from China, to be suddenly 

 extinguished by cold northerly currents in the earliest Triassic 

 times. As to the Carboniferous glaciation of Europe he finds insuf- 

 ficient evidence, and does not notice the granite boulders in our 

 Carboniferous limestone, but he considers the extension of the glacial 

 conditions into Permian times in Europe as beyond all doubt. 



This is the barest possible outline of a Paper which shows 

 strongly the breadth and subtlety to which palreontological views 

 of geological history may be extended. We must not, however, 

 suppose that the theory which Dr. Waagen builds with much re- 

 liance upon data widely separated will be at once accepted; indeed 

 he seems to have based his largest deductions upon assertions of his 

 own, not universally recognised, thus : the Carboniferous age of the 

 whole of the Salt Range boulder beds appears to have been all that 

 he wanted to reconstruct the geological and glacial conditions of a 

 very large part of the world's surface in that period ; but this very 

 point of age may be regarded as open to question, for it is on 

 record 1 that the fossils upon which the assumption of the carbon- 

 iferous age of the boulder beds is based are enclosed in transported 

 pebbles from a source as unknown with accuracy as that of the 

 crystalline and porphyritic boulders in the same deposits ; and 

 though some parts of these Salt Range boulder beds certainly 

 underlie strata containing Carboniferous organisms to the westward, 

 towards the east other parts of their detrital accumulations, which 

 have furnished the most perfectly striated and many-sided facetted 

 pebbles, are physically inseparable from layers containing the sup- 

 posed early Cretaceous Carclita beaumonti, and pass by gradation 

 upwards into the base of the Eocene or Nummulitic limestone. 3 

 Taking this as an instance of uncertain grounds for world-wide 

 conclusions, while admiring the ingenuity and research of the 

 retrospect, we may place greater confidence in the more cautious 

 general opinions of others favouring the glacial character of the 



1 Oldham, Eec. Geol. Sur. Ind., six., p. 127. 



2 K. D. Oldham, loc. cit., p. 129. Wynne, Mem. G. Sur. Ind., vol. xiv. 



