THE 



SILURIAN SYSTEM, 



FOUNDED ON 



GEOLOGICAL RESEARCHES 



IN THE COUNTIES OF 



SALOP, HEREFORD, RADNOR, MONTGOMERY, CAERMARTHEN, 

 BRECON, PEMBROKE, MONMOUTH, GLOUCESTER, 

 WORCESTER, AND STAFFORD ; 



WITH 



DESCRIPTIONS OF THE COAL-FIELDS AND OVERLYING FORMATIONS. 



BY 



RODERICK IMPEY MURCHISON, F.R.S. F.L.S. 



VICE-PRESIDENT OF THE GEOLOGICAL SOCIETY OF LONDON, 

 GENERAL SEC. BRIT. ASSOC. ADVANCEMENT OF SCIENCE, 

 MEMBER OF THE ROYAL GEOGRAPHICAL SOCIETY, 

 HON. MEM. OF THE ROYAL IRISH ACADEMY, 

 ETC. ETC. ETC. 



IN TWO PARTS. 



PART I. 



LONDON : 

 JOHN MURRAY, ALBEMARLE STREET. 



1839. 



