256 PROF. E. HULL ON THE GEOLOGICAL RELATIONS 



elaborate paper " On the Physical Structure of "West Somerset and 

 jS'orth Devon"*, from which I shall have occasion to quote rather 

 frequently ; and the reader may he referred to it for an account of 

 what others have done in this field of inquiry. This paper renders 

 any attempt of the same kind altogether useless. 



It is also scarcely necessary for me to do more than to allude to 

 the controversy which called forth Mr. Etheridge's exhaustive 

 paper. We all recollect with what ardour and ability my friend 

 and predecessor, the late Professor Jukes, endeavoured (as we may 

 say) to obliterate the great group of marine beds established by 

 Murchison and Sedgwick under the name of " Devonian " from off 

 the geological map of the British Isles and of Western Europe. If 

 success had been possible, lie ougJit to have succeeded; but for myself, 

 I feel satisfied that success was impossible, because the evidence, 

 both physical and pala3ontological, in favour of the views of the 

 founders of the " Devonian System " is overwhelming ; and if any 

 doubt on this point remained after Professor Jukes's papers had seen 

 the light, it has been completely removed by the essay of Mr. 

 Etheridge, supplemented, in the same volume of our Journal, by 

 that of a careful and accurate observer, who for years had studied 

 these rocks on the spot, Mr. Townshend M. Hallf. A recent visit 

 to the district confirms me in the belief that between the "Eoreland 

 Grits " and the Carboniferous Limestone there is a great and con- 

 secutive series of marine beds, and that it is comparable (with cer- 

 tain modifications) to the Belgian section of the same rocks. 



II. Statement of the case. 



Perhaps the simplest way of presenting my subject will be to 

 state the case in a series of separate propositions or theses, and then 

 to offer for consideration the evidence upon which they are based. 

 Considered in the order in which I propose to treat them, they may 

 thus be stated. 



First. Having, in the paper already referred to, shfiwn that 

 between the Glengariff grits and slates (which, for brevity, I shall 

 henceforth call " the Glengariff beds ") and the succeeding forma- 

 tions, either of Old Bed Sandstone or Carboniferous age, there is a 

 wide hiatus of unrepresented time, I shall endeavour to show that 

 this is filled up in the south and south-west of England and in Bel- 

 gium by the great series known as " the Middle " and " Lower 

 Devonian " beds, lying between " the Eoreland Grits " on the one 

 hand, and " the PickweU-Down Sandstone " on the other. 



Secondly, That, consequently, while a deep sea in which were 

 deposited the Middle and Lower Devonian beds overspread the 

 south of England and adjoining continental areas, land conditions 

 prevailed in the south of Ireland during the same period. 



* Quart. Journ. Geol. Soc. vol, xxiii. p. 568. 



t " On the Eelative Distribution of Fossils in the North-Devon Series." In 

 a recent joint paper by Messrs. Champernowne andUssher, " On three traverses 

 made in North Devon," they state that their observations go to confirm Mr. 

 Etheridge's views. 



