[xii-B] See Memoir by the Author, Quart. Journ. Geol. Soc., vol. vii. p. 240.

[xiii-A] Würtembergisch. Naturwissen. Jahreshefte, 3 Jahr. Stuttgart, 1847.

[xiii-B] Nov. Act. Acad. Cæsar. Leopold. Nat. Cur. 1850, p. 902. For figures, see ibid. plate xxi. figs. 14, 15, 16, 17.

[xiv-A] See Manual, [p. 268.]

[xv-A] Manual, [p. 289.]

[xv-B] Ibid. [p. 268.]

[xvi-A] For Terminology, see Note, p. 223.

[xvi-B] Quart. Journ. vol. vii. Memoirs, p. 111.

[xvii-A] Principles, 1st ed. chaps. v. and ix.

[xvii-B] Ibid. p. 153.