252 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Apr. 17, 



namely, from the sandstones comprising the promontory of the Fore- 

 land, at the base, to the grits and slates &c. overlying the Upper Old 

 Red Sandstone of Pickwell Down to the south. The author has been 

 unable to see any trace of a fault of sufficient magnitude to invert 

 the order of succession, or that would cause the rocks of the Foreland 

 at Lynton to be upon the same horizon as those south of a hue of 

 high ground that passes across the county from Morte Bay on the 

 west to Wiveliscombe on the east. 



The Foreland grits and sandstones are overlain by the Lower or 

 Lynton slates, and form a group equal in time to the Lower Old 

 Bed Sandstone of other districts, but deposited under purely marme 

 conditions. 



The author then shows that above the Lower or Lynton slates 

 there is an extensively developed series of red, claret-coloured, and 

 grey grits, from 1530 to 1800 feet thick ; these form a natural and 

 conformable base to the Middle Devonian or Ilfracombe group. The 

 highest beds, containing Myalina and Natica, insensibly pass into 

 the gritty and calcareous slates of Combe Martin, Ilfracombe, &c. ; 

 this Middle group Mr. Etheridge unhesitatingly regards as the 

 equivalent of the Torquay and Newton Bushel series of South 

 Devon. 



Mr. Etheridge gives detailed Tables of the organic remains of the 

 two groups (the Lower, or Lynton, and the Middle or Ilfracombe), 

 and collates with them those species found in equivalent strata in 

 Ehenish Prussia, Belgium, and France. He is inclined to believe 

 that these two marine fossiliferous groups represent in time the 

 unfossiliferous Old Eed Sandstone (Dingle beds) of Xerry, and the 

 Glengariif and Killarney Grits of the south-west of Ireland. 



The author then endeavours to prove that the Pickwell Down 

 beds are the true Upper Old Red Sandstone only, not the whole of 

 the formation, as was lately proposed. 



Arguments are also brought forward to show the probability of 

 the Carboniferous slate (in part) and Coomhola grits being the equi- 

 qualent of the EngHsh Tipper Old Red Sandstone, or Upper Devo- 

 nian, and that the North Devon beds only are to be regarded as the 

 true type, to which the Irish must be compared, and not vice versa. 



Physical and palseontological evidence distinctly proves, the author 

 states, that the whole of the slates and limestones of Lee, Ilfra- 

 combe, and Combe Martin underlie the Morte Bay Red Sandstones. 



The author compares the whole of the Devonian fauna of Britain 

 with that of the Rhine, Belgium, and France, by means of a series 

 of Tables based upon the British types. These marine Devonian 

 species are compared with those of the Old Red Sandstone proper, 

 the Silurian, and the Carboniferous ; and analyses are made of all the 

 classes, orders, genera, and species, in relation to the groups of 

 rocks in which they occur, — the result being the conclusion that the 

 marine Devonian series, as a whole, constitutes an important and 

 definite system. 



