104 Mr. H. H. Howorth on 



and afford no proof of ice action!' (Geo/. Mag., " Decade 

 III.," Vol. i, p. 74). To revert to Mr. Prestwich — 



" It is on facts of the same character as those which Dr. 

 Croll adduces for the pliocene period that he would have found 

 evidence of the action of ice in Scotland during" the oolitic 

 period ; but we must seek for some other explanation to 

 account for the incompatible fact that at those times warm 

 conditions of climate extended to 70° — 8o° north, and that 

 corals, Cephalopods, and huge reptiles swarmed in the seas." 

 I would add that, so far as I know, no striated boulder has 

 ever occurred in the oolitic rocks. 



"Nor is it easy to admit a claim for ice action during 

 carboniferous times when the luxuriant vegetation of the coal 

 measures flourished not only here but on Bear Island and 

 other northern lands. With respect to the blocks of granite 

 alluded to as occupying the lower beds of the coal measures 

 in France, they may be, like the tors of Cornwall, blocks 

 left in situ from the decomposition of the granite on which 

 the coal measures there rest, or they may be boulders washed 

 down at that period by the torrents from the adjacent 

 granite mountains. Other foreign pebbles may be accounted 

 for as we have accounted for those in the chalk." (Quart. 

 Jour. Geol. Soc. for August, 1887.) 



In a paper on certain boulders of quartzite found actually 

 imbedded in a coal seam in Leicestershire, Mr. W. S. Gresley 

 collects a number of other instances of their occurring in 

 coal measures from other localities, and shows that these 

 rounded and water-worn boulders were the debris left by 

 currents of water, and he argues that they were dropped or 

 washed out of the roots of trees as they were floated along 

 in flood time from higher ground on which they grew. 

 (Geol. Mag., "Decade III," Vol. II., 553-555-) 



Professor V. Ball again writes, " Angular fragments of 

 granite and of schist, quartzite, and reinquartz have been 

 discovered in beds of carboniferous limestone near Dublin." 



