[13] See Remarks on the Structure of Calamites by W. C. Williamson, Philos. Trans., 161, p. 477.
[14] Williamson on the Structure and Affinities of Sternbergiæ, in Manch. Lit. and Phil. Soc. Mem. ix. Dawson on Sternbergia, in Edin. New Phil. Journ., new series, vii. 140.
[15] See Notice of Antholithes Pitcairniæ, by C. W. Peach, in Bot. Soc. Trans. Edin. vol. xi.
[16] See Professor Duns on the association of Cardiocarpum with Sphenopteris. Proc. R.S.E., April 1, 1872.
[17] See Meyer's Palæontographica, Cassel, 1864.
[18] See fuller description of Coniferæ and Cycadaceæ in Balfour's Class Book of Botany, pp. 906-912.
[19] Coal in the Kimmeridge clay is probably of animal origin.
[20] Carruthers, Geol. Mag., vol. viii. December 1871.
[21] Annals and Mag. of Nat. Hist. 2d ser. ii. 380.
[22] Journ. Geol. Soc. of London, vii.