Stonehouse, and in other parts of the hill near Mill Bay. Some of the specimens of shells and madrepores, which I now send, are from a part of Stonehouse Hill, a little to the west of the quarry at Mill Bay. They were broken from detached stones lying in undisturbed ground considerably below the surface, and agreeing in appearance with the solid rock. The quarry at Mill Bay lies about a mile and a half east of the Dock Yard. The specimens from this quarry were also broken from detached masses of rock found at different depths.
Still further to the east, under the citadel, at the east end of the Hoe, I have found many well-defined shells belonging chiefly to the genus Turbo, some in detached masses, some imbedded in the solid rock; but the substance of the shell in these specimens is so altered, as to exhibit the colour and texture of the surrounding matter Lastly, in a quarry at Cat-down, I have obtained shells or rather fragments of shells, as well as madrepores, but in small quantity, and not so perfect as elsewhere. It has hitherto been a point in dispute whether the limestone at Plymouth does or does not contain organic remains; but I hope that the specimens which I now send the Society will be considered as deciding the question; it must be admitted at the same time, that the instances where shells occur are by no means frequent, and that they are not then found in any quantity. I send herewith a tooth, which, together with many others, and the head and bones of a large animal, was found in the Breakwater quarries at Oreston, at the bottom of a cave or hollow in the limestone rock. It was sent by Mr. Whidbey to Sir Joseph Banks.
I take this opportunity of observing, that on the eastern side of the Sound, under Statten Heights, and nearly in a line with the great national work the Breakwater, there occurs a remarkable
