703 



Professor Sedgwick and R. I. Murchison^ Esq., on the 



analogy. Thus the terms Carboniferous system, Devonian system, Silurian 

 system, and Cambrian system, will represent a vast and apparently uninter- 

 rupted sequence of deposits ; each having, as a whole, zoological and (often 

 also) mineralogical characters of its own, yet each passing into the system 

 next in order by almost imperceptible shades of difference. The old palao- 

 zoic rocks appear, therefore, notwithstanding their enormous scale, and 

 the wide diffusion of the same organic types, to have been formed in subor- 

 dination to the same laws which, in after periods, produced the more clear 

 succession of our secondary formations. 



English Channel. 



Section from the Foreland on the Bristol Channel to the English Channel. For the details of 

 the portion between the Foreland and Dartnnoor, see Plate LI. fig. 1. 



