118 The Cambrian and 



were all of them species of the Bala group ; but, unquestionably, 

 that did not prove them fossils of any true Silurian stage. 



7. As to evidence derived from foreign regions, I by no means 

 protest against the reasonable use of it ; but I do protest against 

 its use in determining the proper fundamental nomenclature of 

 British rocks. Questions of this kind must be decided on British 

 evidence ; neither can I now (from utter want of documents) dis- 

 cuss what my friend calls induction, made in 1843. At that time 

 I did believe that my friend's lower Silurian groups would be 

 found to descend as far as the Bala limestone — that the Bala lime- 

 stone was Caradoc — and that a considerable part of the undulating 

 groups of South Wales would turn out Upper Silurian. How I 

 came, in 1843, to entertain, hypothetically, these erroneous views, 

 and how I got rid of them, are questions I have discussed in a 

 paper which before this time is probably published in the Quar- 

 terly Journal of the Geological Society. 



8. Lastly, I request the reader to bear in mind that my whole 

 position is not aggressive, but defensive. I continue to use the 

 nomenclature mutually agreed upon about sixteen or seventeen 

 years since. The rocks found in Wales, and not in Siluria, I still 

 call Cambrian. All the rocks in Siluria are still called Silurian. 

 My scheme involves no geographical incongruity, deprives my 

 friend not of one single rock he is entitled to name on British evi- 

 dence, and it has the incontestable right of priority. It does not 

 exclude the Llandeilo flag from the rocks of Siluria. But this very 

 Llandeilo flag (the Bala limestone) was in 1834 placed by my 

 friend among the Upper Cambrian groups, and in a region where 

 the sections were unambiguous and rightly interpreted ; while the 

 typical Llandeilo flag of South Wales was utterly misinterpreted 

 by himself as to its geological relations. All this is clear to de- 

 monstration ; and the conclusions that follow from it are inevi- 

 table, and settle at once all grounds of difference between my friend 

 and myself. No man living can have a right to change his no- 

 menclature by fashioning it to sections which are wrong, while he 

 discards sections which are right. 



In all his argument he seems to think especially of the import- 

 ance of perpetuating his own premature nomenclature of foreign 

 rocks ; and this view warps his whole argument. His premature 

 nomenclature is to be vindicated at whatever cost, and without any 

 reference to the published sections of a fellow-labourer, who had 

 honestly worked through the vast and most difficult series of true 

 Cambrian rocks, and knew their relations ; while he had himself 

 barely touched the same series on its outskirts — had only pre- 

 tended to describe two of its highest stages ; and, as to the lower 

 of these two stages, had irremediably blundered. Hence he has 

 been compelled to adopt a monstrous scheme of development, lead- 

 ing to the monstrous conclusion that his single stage — the Llan- 



