Note 15 — Chapter V · ON THE OLDER TERTIARY FORMATIONS OF PATAGONIA AND CHILE.

Professor Forbes has some admirable remarks on this subject, in his “Report on the Shells of the Ægean Sea.” In a letter to Mr. Maclaren (Edinburgh New Phil. Journal, January 1843), I partially entered into this discussion, and endeavoured to show that it was highly improbable, that upraised atolls or barrier-reefs, though of great thickness, should, owing to their small extension or breadth, be preserved to a distant future period.