The elevated Drift deposits near Dublin have been brought under the notice of the Society by other observers. The late Mr. John Kelly has described in our Journal (vol. vi. p. 133) part of the gravels which form the subject of this paper; including the collection at Caldbeck Castle, 1300 feet above the sea. I have already mentioned before the Society (in 1867) the fact of having found marine shells in the Pleistocene gravels near Dublin, at heights of 1000 and 1200 feet above the present sea-level; but I did not wish to offer a paper on the subject until I had collected what might seem sufficient materials for one. These shells are not only in a very fragmentary condition, but also scarce, so that they easily escape notice; and it is necessary to pay several visits, at sufficient intervals, to the few places where the shells are accessible, in order to obtain from thence even a limited collection of detenninable species.