The idea that the well-known shell-bearing sands of Moel Tryfaen indicate a submergence to the depth at which they are found, cannot perhaps be yet said to be, in the language of Mr. Dugald Bell, “a day-dream of the past,” though it is fast becoming so. Towards this result there must be two stages—disbelief in the submergence, and belief in something else. As to the first, Sir A. Ramsay wrote—“He must be a bold man who could see the shellbeds at Moel Tryfaen and deny that the sea had been there.”

The specimens which form the subject of this note were sent to me by Mr. G. F. Franks, F.G.S., of Bridgetown, Barbados, and were obtained by a correspondent of his from the island of Canouan, one of the Grenadine group. Mr. Franks had made slides from three of the samples, and having recognised them as foraminiferal limestones he sent them to me for fuller examination, stating at the same time that the limestone was associated with a compact igneous rock, apparently a porphyritic andesite, with abundant glassy ground mass enclosing streams of microliths. He also sent fragments of four differenct varieties of the limestone, and my friend Mr. W. Hill has been kind enough to cut me a slide frome one of these which appeared different from the others.

In the course of a recent prolonged residence in Tuscany and the Carrara Marble District, I had occasion to become well-acquainted with the Maremma hills and the islands composing the Tuscan Archipelago; and as I propose to revisit those islands at an early date with a view to more closely examine certain phenomena relating to the eruptive and metamorphic series more especially of Elba, it may not be out of place if, in the meantime, I give a rapid preliminary sketch of the leading geological and petrological features of that archipelago as a whole.