In a recent visit to the Isle of Man, I spent three long days in examining the deposits of the very interesting district in the south of the island, and I wish to draw the attention of your readers to some facts which are, I think, important. Not being an experienced geologist, I hope I shall do so with becoming modesty, and I should feel very gratified if some more practised geologist would verify my statements, which are, however, not rashly made, as I have sifted the question with care and patience.