The stratified rocks of Forfarshire, to the south of the Grampian range, belong entirely to the Old Bed Sandstone division of the geological series. They consist chiefly of coarse grits, dark-red and grey sandstones and flagstones, immense masses of conglomerate, with intercalated flagstones, sandstones, and shales, marly and argillaceous shales, and some crystalline limestones or cornstones. These, although in many instances broken up, and often faulted and contorted by trappean outbursts, all rest conformably the one upon the other. Thrown up against the flanks of the Grampian range at very high angles, and dipping towards the south-east, some very-fine sections are afforded by the streams which, issuing from these mountains, cut through the sandstones, in many instances in a line almost at right angles to their strike. Of these the North Esk, the West Water, the Koran, and the Isla may be mentioned as affording peculiar facilities for studying these formations. In all places I have yet examined the Forfarshire sandstones are cut off from the schists and slaty beds of the Grampians by considerable outbursts of trap; it is, however, pretty evident that the sandstones overlie these schists unconformably. Although I do not intend at present to go at all into the geology of the Highland districts of Forfarshire, I may here state that it seems to me highly probable that these schistose beds may be the equivalents of some portion of the Lower Silurians.