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.