688 PEOCEEDIN-GS OF THE GEOLOGICAL SOCIETr. 



beds of Lynton, Combe Martin, and Ilfracombe may belong to the 

 Carboniferous Slate rolled to the north by contortions, and some- 

 what differing lithologically from those further south." No rolling 

 has destroyed the value of the intermediate fossiUferous Middle or 

 Ilfracombe and Combe-Martin group; for of the seventy species 

 found in these beds, six only recur in the Carboniferous series of any 

 area, viz. Gyathocrinus variabilis, Fenestella antiqua, RhyncJionella 

 pleurodon, M. pugnus, Streptorhynchus crenistria, smdAvicula vetusta. 

 All these are also in the intermediate Upper Devonian series in North 

 Devon. Thus, then, these beds on the north coast, which are below 

 the red beds of Morte Bay, do " disclose facts which have no parallel 

 in the south-west of Ireland;" but there is no doubt as to their 

 stratigraphical place, or the zoological .value assigned to them. 



If we admit the physical succession of the North-Devon rocks to 

 be established, and that they constitute three well-defined groups, 

 this of necessity destroys the views of Professor Jukes, who believes 

 that the uppermost bed of the Old Eed Sandstone was in existence 

 before any of the beds containing marine Devonian fossils were 

 deposited ; and his Old Red Sandstone is the non-fossiliferous red 

 series which strikes from Morte Bay through Garmon Down, Span 

 Head, Dulverton Common, to Haddon and Main Down (Wivelis- 

 combe), which red sandstones, according to the hypothetical fault, 

 are the Foreland beds to the north repeated, caused by the supposed 

 great downthrow existing between these two points ; consequently, 

 upon this hypothesis, the Toreland grits and sandstones and the 

 Lynton slates, with the overlying fossiliferous Ilfracombe group, 

 and the non-fossiliferous Mortehoe slates, are, or should be, above 

 his Old Red Sandstone, both being the same by virtue of the 

 fault : this, I maintain, is not borne out either on physical or 

 zoological grounds. I doubt not for one moment that the red 

 sandstones in question may be the equivalents of the "Welsh and 

 Irish Upper Old Red Sandstone with the fossiliferous Upper Devo- 

 nian series resting upon them and the surrounding or associated 

 Carboniferous Slates and Coomhola Grits also ; but I do not admit 

 the existence of the fault, and I endeavour to prove that we have in 

 North Devon a complete succession of the three groups, determined 

 physically and palseontologically. 



The relation that the Upper red sandstones of Pickwell &c. have 

 to the overlying fossiliferous Upper Devonian slates, sandstones, and 

 grits is the same relatively that the thick Middle group of sand- 

 stones of the Hangman, Trentishoe, Martinhoe, &c, have to the 

 Middle Devonian or fossiliferous calcareous slates of Ilfracombe and 

 Combe Martin above them ; and on equally good grounds we are 

 enabled to establish a base for the Lynton slates and gritty lime- 

 stones upon the non-fossihferous red sandstones of the Poreland. 



This order of succession is not only a true one, but it is in 

 accordance with the reading of the succession in Europe ; it is based 

 both upon the position of the rock-masses of North Devon, and 

 upon their associated groups of fossils. The physical conditions 

 coinciding with the zoological evidence, it is that group, as a 



