Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/858

718 718 PROF. E. HULL ON THE DINGLE .BEDS AND IY. Relations oe the Upper Silurian Series oe the south-west oe Ireland to those in the Silurian Region of England. From what has been said, it will be observed that, along with the late Sir R. Griffith, I regard the great series represented in the Dingle promontory, from the " Sybil (Upper Llandovery) beds " to the highest of the " Dingle beds," as the equivalents of the whole Upper Silurian series of the typical Silurian region bordering the Severn and Wye. Owing to the occurrence of considerable beds of lime- stone and distinctive characters, both penological and palaeontolo- gical, the Upper Silurian series of England and Wales is divisible into well-marked stages, as established by Murchison ; such, how- ever, is not the case in the west of Ireland. This has been acknow- ledged by Sir R. Murchison himself in reference to the district of West Mayo and Galway, and is not less true in reference to the districts of Dingle and Kerry. The remarkable statement by the late Prof. Jukes which I have already referred to, may be regarded as con- clusive* on this head ; he states that " the Sybil-Head beds, the Smerwick beds, and the Dingle beds are all purple slates and con- glomerates of exactly similar general characters, so that it would be impossible to distinguish them." This statement, taken from his notebook as a general conclusion after an examination of the whole section from bottom to top, completely confirms the view I have been advocating in this paper. If we compare the sections in the S.W. of Ireland with those in the typical Silurian region, we shall find the representative strata somewhat as follows : — Upper Silurian Series of England and Ireland. England (Severn and Wye District). Ireland (Kerry). ft. Ludlow beds and passage-beds 150 ) -,-.., ,, ^^ r a ± r ■ t. Ar Dingle beds or Glenga- ^ {fet^°- ■'..::::::::: m *«*>«*>** C Wenlock Limestone 280 ) Wenlock J Wenlock Shale 1 onnn | beds. 1 Denbighshire Grits j Ferriter's Cove and Smer- tTararmon Shale 1500^- lSwvl U PP er Llandovery lime- t [(m wick beds. • i v I upper jjiojiuuverj j"" i i i ^ | stone and sandstone j Upper Silurian beds 6670 Erom the above comparisons it will be observed that there is a large accession of materials in the upper portion of the series in the south of Ireland as compared with the representative beds in the south of England and borders of Wales. In both regions the Upper of Prof. Jukes's notebooks, dated May 31, 1858, after the above paper was almost written, and is accompanied by a sketch and section intended as " a key to the whole promontory," by which he shows that the fossiliferous Ferriter's Cove beds are in part repeated in the Smerwick beds, owing to an inversion.
 * This statement was only discovered by Mr. O'Kelly (Oct. 19, 1878) in one