The strata, as upon Earth, were of various character, none of them very thick, seldom reproducing exactly the geology of our own planet, but seldom very widely deviating in character from the rocks with which we are acquainted.

The lowest were evidently of the same hard, fused, compressed character as those which our terminology calls plutonic.

Above these were masses which, bike the carboniferous strata of Earth, recalled the previous existence of a richer but less highly organised form of vegetation than at present exists anywhere upon the surface.

Intermixed with these were beds of the peculiar submarine shell-rock whose formation I have just described.

Above these again come strata of diluvial gravel, and about 400 feet below the surface rocks that bore evident traces of a glacial period.