During the past autumn the London and South-Western Railway Company has been engaged in widening the line between Walton and Weybridge stations, and consequently there has been an excellent exposure of the beds composing the Walton-Oatlands plateau. The communication now made to the Society relates only to such portion of the railway-cutting as extends from Walton station in a west-south-west direction to the boundary of Oatlands Park, and more particularly to that portion of it known as “America.” The total length, as measured on the 6-in. Ordnance map, is 1070 yards. This distance is divided unequally by the railway bridge on Walton Common known as “Sir Richard9s.” The distance between Walton station and the centre of this bridge is 710 yards, whilst the distance from this point to the boundary of Oatlands Park is 360 yards, or thereabouts. For the purposes of description and convenience of reference, the entire section may be divided into four blocks. Block A extends from Walton station to where the unaltered London Clay in seen to occur in situ —a distance of 313 yards. Block B extends from this to the point where the Bagshot Beds are first seen in situ —a distance of 345 yards. Block C extends from the above to the point where the Bagshots are first cut through to the level of the line, and the hollow filled up with Plateau-gravel—a distance of 165 yards. Block D exhibits the relations of the Bagshots to the Plateau-gravel, where the latter is most fully developed—a.