172 Classification of the Fossiliferous Rocks. 
While speaking on this subject we cannot overlook the controversy 
respecting the terms Cambrian and “ lower Silurian,’ as it is still far 
from being settled ; but we truly hope it willbe so in a philosophic point 
at the next meeting of the British Association, by the most compe- 
tent judges of the country. The journalist, who is undoubtedly 
guided by the best known and most correct information on the sub- 
ject, is not in a position at present to give any decided information. 
At the last meeting of the Association, three of our best geolo- 
gists, Hopkins, Philips, and Strickland, agreed, and expressed a 
strong conviction, that Sedgwick would ultimately succeed in esta- 
blishing his nomenclature ; and on the other hand we have a party 
who think otherwise. It is not now the time to use either 
disguised or ambiguous phraseology. Let the question be determined 
on truth, and let truth only be the Polar star, and on this ground 
only let the combatants stand or fall. We can no longer be guided 
by the creed which certain parties assume in order to gratify the 
feelings or the prejudices of the party for which he caters to at- 
tract attention. 
To shew how this disputed question now stands, I perhaps can- 
not do better than quote the opinion of Professor Jukes, President 
of the Geological Society of Dublin, on this subject. ‘‘ I will just 
here say one word,” remarks Mr Beete Jukes,* ‘as to the con- 
troversy respecting the terms ‘ Lower Silurian’ and ‘ Cambrian.’ 
It resolves itself into a question of whether we should take paleeonto- 
logical or lithological and stratigraphical characters as the founda- 
tion of our classification. Every one, including Professor Sedgwick 
and Sir Roderick Murchison, used to think that the rocks and fossils 
of Caernarvonshire and the neighbouring parts of North Wales, 
would of necessity be all older than those of Montgomeryshire, Shrop- 
shire, and the Welsh border country. The Silurian rocks and fossils, 
therefore, with their sub-division into upper and lower, were accepted 
as one thing, and the Cambrian rocks and fossils were expected to 
turn out another thing when the latter came to be fully described. 
Instead of that, it results that what were called the Lower Silurian 
rocks on the Welsh border, and which were left with a totally un- 
defined base, had really a much greater thickness than was expected, 
and swept in many broad folds and undulations through the whole 
of North Wales, and that the rocks of Siluria, with the exception of 
the uppermost, were the same as those of Cambria. In Cambria, 
however, the rocks only were described, while in Siluria both the 
rocks and fossils were described and figured, neither, indeed, com- 
pletely, but both so much so that the contemporaneous rocks of other 
countries could be recognised by their fossil characteristics. Had 
the identity of the rocks of Cambria and Siluria been known at the 
time, it is probable that only the upper would have been called 
* President of the Geological Society, and Director of the Geological Survey 
of Ireland. 
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