1 1 8 The Rev. D. Williams's Proofs that the Devonian 



of the Old Red Sandstone which fills that whole intermediate 

 position." Athenseum, No. 736, page 937. 



Admitting the validity of the organic test for the sake of 

 argument, it has not yet been shown that the Devon and 

 Cornish organic fossils are of the requisite intermediate type 

 or proportion, taking the mountain limestone as a standard 

 of reference, to justify the identification contended for; nay 

 more, I contend that when the elements of the premises are 

 fairly distributed, the result will tend rather to impeach the 

 Old Red hypothesis than to confirm it. 



It is remarkable that the froportions given in Lonsdale's 

 Table *, from the limited area of the South Devon limestones, 

 should agree so nearly with Phillips's Tables, drawn from the 

 entire region : it tends at least to warrant an inference that 

 future discoveries in the Devonian and Carboniferous systems 

 generally may not cause those proportions to vary materially 

 one way or the other. 



Up to the period of the publication of the Palaeozoic Fossils, 

 the aggregate numbers stand thus : — 



Mountain and magnesian lime species .... 420 

 Devonian species 275f 



Of the latter, fifty-one are determined as mountain lime 

 species. We appear thus to attain good evidence that the 

 earth in by-gone ages has not been visited by periodical uni- 

 versal suspensions of animal and vegetable life, followed by 

 perfectly new creations, while a great moral caution is tacitly 

 but emphatically conveyed as to the application of testimony, 

 drawn from organic remains, to establish remote equivalents. 



Omitting the probability that many mountain lime species 

 will yet be found in Silurian strata or their coeval deposits, 

 the revolting and, to me, monstrous conclusion implied by the 

 Old Red hypothesis is, that during the period of the Old Red 

 Sandstone (a formation which has been repeatedly stated to 

 pass by well-defined transitions into the mountain limestone) 

 a ratio of 224 species of corals, encrinites and hardy mol- 

 luscs out of every 275 must have been finally and universally 

 obliterated from the creation, and replaced by 369 new 

 species. An analysis of the Devonian species by ^ Phillips, 

 gives 



Polypiaria. — 34 species, of which two only are mountain 

 lime. 



Crinoidea. — 16 species, of which four only are carboni- 

 ferous. 



Conchifera Plagirayona ... 26 Mountain Lime 2 

 Mesomyona ... 20 2 



• Geol. Trans. 2nd series, vol. v. part iii, p. 737. 

 f Phillips's Palaeozoic Fossils, p. 165. 



