R. M. Deeley—The Glacial Succession. ol 
distance of three miles, showed the slates dipping to the north-west 
at a high angle (about 45°), so that a considerable thickness of slate 
must underlie those which yielded the trilobite. The thickness also 
of the overlying slates must be considerable. 
The. finding of the interesting specimen which we have described, 
in the midst of the Skiddaw Slates of the Isle of Man, will, we trust, 
stimulate research and lead to increased attention being paid to these 
beds. 
VIL.—Tue Gractat Succusston. 
By R. M. Dzztzy, F.G.S. 
LL students of British Glacial geology must feel that to Prof. 
James Geikie we owe much of our present knowledge con- 
cerning the Pleistocene succession in Europe; for he has not only 
been a zealous worker in the field, but has placed before us in a 
clear manner the valuable investigations of Continental geologists, 
with a view to showing how the succession that has been made out 
on the main land may be made to agree with that of our islands. 
In a paper read before the Royal Society of Edinburgh last May, 
“On the Glacial Succession in Europe,” we have his latest important 
contribution to this subject. No doubt when we have the promised 
new edition of the ‘“‘Great Ice Age” in our hands, giving in detail 
the facts upon which he bases his conclusions, we shall be better 
able to appreciate the points he raises in this paper. Still the 
succession he has adopted is so clearly described, that in the absence 
of his more complete work, and even though he has not referred 
specifically to English deposits, I may, perhaps, be allowed to 
compare his results with those I gave in a paper read before the 
Geological Society in 1886. 
Many geologists even now seem to be far from having come to a 
decision as to whether there really was any considerable alternation 
of warm and cold epochs during the Pleistocene period, nor can it 
be said that there is more than a general agreement in many cases 
between the successions made out by workers in different districts. 
We must, therefore, be content at present to state the opinions at 
which we have individually arrived, and by comparing the results 
so obtained strive to construct a true history of the Pleistocene 
period. That this can be accomplished there seems to be no doubt 
whatever; but whether it can be arrived at by a fuller appreciation 
of the facts now at our disposal, or whether it will result from 
future discoveries, remains to be seen. 
I trust that it will not be supposed that I wish to deal with 
Professor Geikie’s conclusions in a captious spirit, or that I wish 
to adversely criticise his conclusions; my object is really to place 
on record what I regard as a possibly correct correlation of the 
succession he has adopted with the one made out by myself, and 
also to refer to certain physical changes which have an important 
bearing upon the question of the age and formation of certain high- 
level shelly gravels. 
Of course it is possible that I may have misunderstood Professor 
