[42] Challenger Reports, No. 2, p. 10.
[43] See “Smithsonian Contributions,” vol. ix.
[44] Quart. Journ. Geol. Soc., vol. xxv., p. 350.
[45] Trans. of Glasgow Geol. Soc. for 1866.
[46] Revue des Deux Mondes for 1867.
[47] Letter to the author, February, 1870.
[48] “Révolutions de la Mer,” p. 37 (second edition).
[49] Edin. Phil. Journ., vol. iv., p. 262 (1821).
[50] Phil. Mag., § 4, vol. xxviii., p. 131. Reader, December 2nd, 1865.
[51] This point will be found discussed at considerable length in the Phil. Mag. for September, 1869.