AKNIVEKSAKY ADDRESS OF THE PRESIDENT. 



193 



Lower Carboni- 

 ferous beds. 



Old Red Sand- 

 stone or "Upper 

 Devonian. 



South of Ireland. 

 / Carboniferous Limestone, 

 j Carboniferous Slate. 



j Coomhola Grrit and Slate (pas- 

 ^ sage-beds. 



C Kiltorcan beds. 



I Old Eed Sandstone and Conglo- 

 [ merate. 



North Devon. 

 Carboniferous Limestone. 

 Barnstaple beds. 



(Pilton beds. 

 Baggy and Marwood beds- 

 ( Cucullcsa-zowQ). 



Upcot beds ? 

 Pickwell-Down Sand- 

 stone. 



Prof. Hull then enters minutely into the question of the equiva- 

 lency and relationship of the North-Devon, Lower and Middle 

 Devonian series to beds, if any, in the South-Irish area. The Irish 

 Upper Old Red Conglomerate does not appear to have had, in that 

 area, any immediate predecessor ; and Mr. Hull suggests and con- 

 tends that the unconformity between the Gleugariff beds and 

 the Old Eed or Carboniferous beds proves that certain strata are 

 absent or were never deposited over the South-Irish area. If Mr. 

 Hull's correlation be correct, it may possibly follow that the Middle 

 and Lower Devonian of North Devon may occupy the place of the 

 missing strata in the south of Ireland. Furthermore, Mr. Hull 

 regards the Foreland grits and slates (the base of the North-Devon 

 beds) as representing in part the Glengariff beds, which he believes 

 to be of Upper Silurian age. The Foreland grits and sandstones, the 

 recognized base of the Devonian rocks in Devonshire, Mr. Hull would 

 correlate with the uppermost Silurian or Passage-group of Sir E.Mur- 

 chison; and he also infers that the great gap which appears to exist 

 in Ireland between the Glengariff beds and the succeeding Old Eed 

 Sandstone and Carboniferous series was filled up in North Devon by 

 the Mortehoe slates, the Ilfracombe series, and the Lynton beds, or all 

 the strata that exist between the base of the Pickwell-Down Sand- 

 stones and the top of the Foreland grits. Mr. Hull's views as regards 

 the representative beds in the south of Ireland, North Devon, and 

 Belgium are carefully tabulated on p. 266 of the 1 Quarterly Journal of 

 the Geological Society,' vol. xxxvi., 1880, the relations of each group 

 being given. The Belgian and Boulonnais sections are also referred 

 to and tabulated. Scotland, through Geikie's latest memoir (Zoc. 

 cit.), is compared with both areas, Devon and North and South Ire- 

 land. On page 273 is also given a table of representative forma- 

 tions for Ireland, North Devon, South Wales, Scotland, and Belgium. 

 These two contributions, by Professors Geikie and Hull, to the his- 

 tory of the Old Eed and Devonian rocks of Scotland, Ireland in 

 part, and North Devon have materially added to our knowledge of 

 their physical history and condition. 



The distribution of the 49 or 50 genera and 125 species of fish 

 through all the known deposits of Old Eed in the British Islands 

 seems to result in there being no middle fish-bearing group, either 

 in England, Scotland, or Ireland. Only 2 genera and 2 species are 

 regarded as Middle Old Eed, Eucejphalaspis (Cephalaspis) Agassizi, 

 Lank., and Holojptychius Murchisoni, Ag. ; but it would hardly 

 appear that these two species are rightly placed stratigraphically. 



