^{page 517 note 1} Especially Sternberg, Brongniart, Goeppert, Petzholdt, Geinitz, Unger, Schimper, Weiss, Renault, and Grand Eury.

^{page 518 note 1} Omalius d'Halloy, Leonhard and Hoernes, Vogt, C. D'Orbigny and Gente, Beudant, Credner, Lapparent, Contjean, and others.

^{page 518 note 2} ‘In a steep rock called Craig y park, and others in the Parish of Istrayd Dyvodog, we observed divers veins of coal, exposed to sight as naked as the rock; and found a flint axe, somewhat like those used by the Americans’ (Phil. Trans. vol. xxviii. 1714, p 501; in a letter dated September 22, 1697).Google Scholar

^{page 518 note 3} The Coal-fields, etc., 4th edit. p. 12.

^{page 519 note 1} Proceed. Geol. Soc. vol. iii. pp. 229 and 487.Google Scholar

^{page 519 note 2} Mem. Geol. Survey, vol. i. 1846, p. 152.Google Scholar

^{page 520 note 1} The Coalfields of Great Britain, 4th edit. p. 81, etc.

^{page 520 note 2} Report and Transactions of the Cardiff Naturalists' Society, vol. xvii. (for 1885), 1886, pp. 20–34.Google Scholar

^{page 521 note 1} Quart. Journ. Geol. Soc., vol. xii. 1856. pp. 38–73;Google Scholar also Report Coal Commission, 1871, pp. 424 and 511, with plates; and Rep. Brit. Assoc. for 1879, p. 227, pl. xiv.

^{page 521 note 2} Pl. i.Q.J.G.S., vol. xii. 1856.Google Scholar

^{page 522 note 1} Mem. Geol. Surv. vol. i. 1846, p. 314.Google Scholar

^{page 522 note 2} See Hull's, ‘The Coalfields,’ etc., 4th edition, pp. 88, etc., and map.Google Scholar

^{page 523 note 1} Ibid, chap. i.

^{page 523 note 2} Etheridge, 1885 p. 238.

^{page 523 note 3} “The Coalfields,” etc., 1881, p. 108.Google Scholar

^{page 524 note 1} “Report,” 1838, Trans. Sec. p. 85.Google Scholar

^{page 524 note 2} Bevan, , “Geologist,” vol. ii. 1859, pp. 78, 79.Google Scholar