In June, 1827, Dr. W. H. Fitton read before the Geological Society of London the following statement:—"It is obvious that, during a period of time sufficient for the accumulation of the Wealden, the deposition of matter in the adjacent seas could not have been inconsiderable; so that we might expect to find, interposed between the strata which then formed the bottom of the sea and the Lower Greensand, a series of beds coeval with the Wealden in point of date, but differing from it in possessing the characters of a marine deposit, and including marine shells and other productions of salt water; with which, near the shore, the productions of the land, or even the freshwater shells of the rivers, might be occasionally intermixed. . 1st. That the Wealden and its marine equivalent could not both be found in the same place; and consequently (since we have the former in England) that the marine beds of that date are not to be expected generally in this country; 2dl