Another locality at which evidence of the gradual elevation of the land can be obtained is found to the west of Black Point, where abundant remains of our present bay shells are found at a considerable elevation above the level of the sea; and, were not the surface of the country, particularly the lower levels, so completely covered in by the drifting sands, no doubt many analogous deposits could be found. To the south and west of the Mission, and in all the lower levels between there and the range of hills overlooking the Puerta Suelo, the surface is covered by these recent post tertiary deposits, through which the older rocks protrude in many places as isolated masses, the recent argillaceous sandstone being deposited in nearly horizontal strata around their base. These sandstones have given rise, by their decomposition, to the extensive surfaces of yellow sandy loam seen between the Mission and the Ocean House. I think the highest of these beds does not attain a greater elevation than one hundred feet above the present level of the ocean. More recent evidence of the gradual elevation of the land is furnished by the holes made by the marine worms in the rocks on the shores of the bay, many of these holes being found at elevations which the highest tides do not at present reach. On the age of these deposits it is useless at present to speculate. All that we know for certain is, that geologically speaking, they are recent; but whether it is five hundred, or five thousand, or fifty thousand years since the present site of Mountain Lake was on a level with the ocean, our present data do not enable us to form an opinion. All that the facts prove is that this portion of the continent is being gradually raised en masse.