^{page 50 note 1} Watts', W. W. substitution of Yorkian in place of Kidston's Westphalian is strongly to be recommended: “Carboniferous Nomenclature,” Geol. Mag., Vol. LIX, 1922, p. 238; see also R. Crookall, “On the Fossil Flora of the Bristol and Somerset Coalfield,” Geol. Mag., Vol. LXII, 1925, p. 393.CrossRefGoogle Scholar

^{page 51 note 1} Howell, H. H. and Salter, J. W. in “The Geology of the Neighbourhood of Edinburgh,” Mem. Geol. Surv., 1861, pp. 103, 105, 144.Google Scholar

^{page 51 note 2} Gunn, W., “Notes on the Correlation of the Lower Carboniferous Rocks of England and Scotland,” Trans. Geol. Soc. Edin., vol. vii, 1899, p. 361; and Geol. Mag., 1898, p. 342. Gunn points out that all except the lowest division of the Scottish “Carboniferous Limestone” Series lies above the Yoredale Beds as defined by Phillips. “The term Yoredale was by the Geological Survey extended so as to include these beds [in Wensleydale, Yorkshire], but they were classed with the Millstone Grit by Phillips, though sometimes he seems to have included a portion of them in his Yoredale Series.”CrossRefGoogle Scholar

^{page 51 note 3} Munier-Chalmas and A. de Lapparent: “Note sur le nomenclature des terrains sedimentaires,” Bull. Soc. Géol. Fr., 3rd ser., vol. xxi, 1893, p. 447; see also A. de Lapparent, Géologie, 5th ed., vol. ii, 1906, p. 889.Google Scholar

^{page 52 note 1} Potonié, H.: “Die floristische Gliederung des deutschen Carbon und Perm,” König. Preuss. geol. Landesanstalt, N.F., heft 21, 1896, pp. 14, 57.Google Scholar

^{page 52 note 2} Frech, F.: “Lethaea geognostica,” Band 2, Lief. 2, 1899, Table xxii, p. 354.Google Scholar

^{page 52 note 3} Renier, A., “Les Gisements houillers de la Belgique,”—chap, viii, Rélations internationales de stratigraphie, Annales des Mines de Belgique, tome xx, 1919, p. 250.Google Scholar

^{page 53 note 1} Crookall, R. in “The Fossil Flora of the Bristol and Somerset Coalfield”: Geol. Mag., Vol. LXII, 1925, p. 395, adopts Kidston's view that the Radstockian is the lowest part of the Stephanian. He, too, quotes Zeiller as approving. The difference is evidently of minor significance.Google Scholar

^{page 53 note 2} Kidston, R., “Fossil Plants of the Carboniferous Rocks of Great Britain”: Mem. Geol. Surv., 1923, p. 14; see also “On the Various Divisions of British Carboniferous Rocks as determined by their Fossil Flora”: Proc. Boy. Phys. Soc. Edin., vol. xii, 1894, p. 183.Google Scholar

^{page 53 note 3} “Summary of Progress for 1903”: Mem. Geol. Surv., 1904, p. 118. “The Geology of the Neighbourhood of Edinburgh”: Mem. Geol. Surv. Scotland, 2nd ed., 1910, p. 6.Google Scholar

^{page 53 note 4} Kidston, R., Cantrill, T. C., and Dixon, E. E. L., “The Forest of Wyre and the Titterstone Clee Hill Coal Fields”: Trans. Roy. Soc. Edin., vol. li, 1917, p. 1066.Google Scholar

^{page 54 note 1} Eyles, V. A. and MacGregor, A. G. in “Summary of Progress for 1924”: Mem. Geol. Surv., 1925, pp. 91–4.Google Scholar

^{page 54 note 2} This unconformity brings Millstone Grit about a quarter way down the Upper Limestone Group which immediately underlies it (see Dinham, C. H. in “Econ. Geol. Central Coalfield Scot., Area IX”: Mem. Geol. Surv., 1921, p. 78, and pl. v). In Ayrshire, comparable phenomena have been met with (see G. V. Wilson in “Sum. Prog. Geol. Surv. for 1913”: Mem. Geol. Surv:, 1914, p 59). Outside of Scotland, unconformable relations have also been proved in South Wales (see O. T. Jones in “The Geology of the South Wales Coalfield, xi, Haverfordwest”: Mem. Geol. Surv., 1914, p. 151; also F. Dixon and T. F. Sibly, “The Carboniferous Limestone Series on the South-Eastem Margin of the South Wales Coalfield”: Quart. Journ. Geol. Soc., vol. lxxiii, 1918 for 1917, p. 157).Google Scholar

^{page 55 note 1} B. N. Peach has expressed very much the same idea when he wrote “As the rocks afford no sign of a physical break in the region under consideration, some great physical change must have taken place outside it to account for the almost complete replacement of the flora and fish fauna by others. Change of climate alone seems powerless to bring about so sudden a revulsion.” Proc. Roy. Phyn. Soc. Edin., vol. xix, 1916, p. 257.Google Scholar

^{page 56 note 1} Renier, A., “Stratigraphie du Westphalien”: Congrès Géol. Intervat., 1922, livret guide, excursion C 4; see also p. 60 of present paper.Google Scholar

^{page 56 note 2} Renier, A., “La More du terrain houiller sans houille (H 1a) dans le bassin du couchant de Mons”: Ann. Soc. Géol. Belg., vol. xxxiii, 1906, pp. 169, 170.Google Scholar

^{page 56 note 3} Renier, A., “Note sur la flore de l'assise moyenne, H 1b de l'etage inférieur du terrain houiller”: Ann. Soc. Géol. Belg., vol. xxxv, 1908, pp. 122, 123.Google Scholar

^{page 57 note 1} Howell, H. H. in 1861 made use of fish in support of his determination of English Coal Measures in Scotland.Google Scholar

^{page 57 note 2} Traquair, R. H., “Distribution of Fossil Fish Remains in the Carboniferous of the Edinburgh District”: Trans. Roy. Soc. Edin., vol. xl, 1903, p. 707.Google Scholar

^{page 57 note 3} It is only right to note that Hercynian is used in Bertrand's sense familiar to British readers, and not in that originally given to it by von Buch, L., see E. Suess, Face of the Earth (Sollas edition), vol. iv, p. 1.Google Scholar

^{page 58 note 1} E. Suess uses the name Eria borrowed from Lake Erie—Face of the Earth, vol. iv, p. 59. For our purpose it is convenient to call the European part of the Erian continent Eureria, as we can then continue the use of the name into post-Devonian times.Google Scholar

^{page 59 note 1} De, Lapparent (Géologie, 5th ed., fig. 376, p. 905) extends the peninsula in Dinantian times; but this seems illogical considering the pan-European character of the Dinantian fauna.Google Scholar

^{page 59 note 2} Dixon, E. E. L. has very definitely combated the depth-hypothesis in its application to certain radiolarian cherts of South Wales, in “The Carboniferous Succession in Gower (Glamorganshire)”: Quart. Journ. Geol. Soc., vol. lxvii, 1911, p. 519. On the other hand, L. Cayeux, in a preliminary announcement, says that the many radiolarian cherts he has examined (horizons not stated) are clearly deep-sea deposits on account of their freedom from quartz, spongespicules, and foraminifera; see “La question des jaspes à radiolaires au point de vue bathymétrique”: C.R. Comm. Géol. Soc. Fr., Janv., 1921, p. 11.Google Scholar

^{page 59 note 3} King, W. B. E., in “The Upper Ordovician Rocks of the South-Western Berwyn Hills”: Quart. Journ. Geol. Soc., vol. lxxix, 1923, p. 494, has already developed this comparison with special reference to Dixon's work. In a similar connexion, J. E. Marr, in “Conditions of Deposition of the Stockdale Shales of the Lake District”: Quart. Journ. Geol. Soc., vol. lxxxi, 1925, remarks “Professor Charles Lapworth, however—see his notes, in a paper by Professor J. Walther, ‘Ueber die Lebensweise Fossiler Meeresthiere,’ Zeitschr. Deutsch. Geol. Gessellsch., vol. xlix, 1897, p. 209—maintained that graptolites were pseudoplanktonic, being attached to floating algae of Sargasso type, and that the colouring matter of the deposits was due to carbon derived from the ‘weed’, although he adduced no analyses in support of this view. Incidentally, he stated that these graptolite-bearing beds were deposited in deep and shallow water alike, the essential conditions being quietness of the waters”. Marr's paper includes a wealth of his own observations in regard to the geological importance of chemico-biological environment.Google Scholar

^{page 60 note 1} Murray, J. and Irvine, R., “On the Chemical Changes which take place in the Composition of the Sea-Water associated with Blue Muds on the Floor of the Ocean”: Trans Roy. Soc. Edin., vol. xxvii, 1893, p. 496. See also the same authors' suggestion that the reaction between the sulphides and clay may render silica available for animal consumption: “On Silica and the Siliceous Remains of Organisms in Modern Seas”: Proc. Roy. Soc. Edin., vol. xviii, 1891, p. 248. Geologists will find useful references of this kind in L. W. Collet's Les Dépôts Marins, Paris, 1908.Google Scholar

^{page 61 note 1} De Lapparent draws attention to a contested determination of Spirifer mosquensis from the east side of the Upper Silesian coalfield, west of Cracow—Géologie, 5th ed., p. 940.