1852.] SEDGWICK ON THE LOWER PALEOZOIC ROCKS. 163 



tions into the lower division of the Upper System (the Caradoc Sand- 

 stone)/'' Again, in the Proceedings (Nov. 1841, vol. iii. p. 548) I 

 gave the same definition of my Upper Cambrian group, and added : 

 " Many of the fossils are identical in species with those of the lowest 

 divisions of the Silurian System.'"' 



xigain, in the next page (p. 549), I give a list of Snowdonian fos- 

 sils, some of which I collected in 1831 . The list was named by Mr. 

 Sowerby the year before Mr. Salter had become my fellow-labourer ; 

 and in 1832 I had at least two species of Ortkis from Snowdon, which 

 I believed identical with two Bala species. Lastly, I will quote the 

 third edition of the Syllabus of my Cambridge Lectures, which was 

 drawn up in 1836 and published very early in 1837, and therefore 

 appeared two years before the publication of * The Silurian System.' 

 Describing the Upper Cambrian rocks, I used, in this Syllabus (p. 51), 

 the following words : " Associated with them are calcareous slates. 

 Corals, Encrinites, Trilohites, Orthoceratites, Orthis, Producta, Spi- 

 rifer, &c. Many shells of the same species with those of the Lower 

 Silurian rocks." Again, in the same page, I affirm, "that the Bala 

 limestone contains Bellerophon bilohatus, Producta sericea, and seve- 

 ral species of Ortkis, all of which are common to the Lower Silurian 

 System.'^ This third edition of my Cambridge Syllabus was withdrawn 

 from publication in 1 840, in consequence of the new palaeozoic arrange- 

 ments become necessary by the introduction of a Devonian series. 

 But the extracts from it above-given, as well as the quotations from 

 our Proceedings, however unimportant in themselves, do bear upon 

 my present question, and prove what I am now asserting, — that I 

 never presumed to separate, palseontologically, the Cambrian from the 

 lower Silurian rocks. If their fossils were of the same general type,> 

 the fact would only prove that Sir Roderick's "Silurian System" 

 never was a system in the sense in which he had expounded it ; but 

 the fact would by no means prove that he had any right to make 

 good his system by extending it over a province already legitimately 

 occupied, and over which he had no personal claims whatsoever. 



On this point I may conclude my remarks, by affirming that my 

 argument is greatly misrepresented by Sir R. I. Murchison '^, when 

 he recommends me to abandon the term Cambrian System as applied 

 to the physical groups of North Wales, because such name was used 

 before their fossil contents were known. His advice, whatever may 

 be its worth, is founded in mistake, and obliviousness as to some facts 

 we studied together in the field ; and he has little reason to fix on 

 me his own meaning of the word " System," which I never believed 

 correct, and against which I have, as above stated, very often pro- 

 tested in the former discussions of this room. 



In 1 834, when I, for the last time, met my friend in Wales, that 

 we might compare notes and determine the limits of our respective 

 surveys, he made no difficulty in excluding the Bala limestone (in 

 spite of its fossils) from his " System," and this was done on the sup- 

 posed evidence of sections. The fact of this exclusion proved that 

 * Quart. Journ. Geol. Soc. vol. iii. p. 175. 



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