The part of North Ayrshire to which the following remarks refer is generally known, geologically, by the name of the Dalry basin. It has an area of nearly thirty square miles of carboniferous strata, is of a triangular form, and lies in the parishes of Dalry, Kilbirnie, and Beith. The south-west angle extends into the north of Kilwinning parish, and, from the other two angles, proceed long narrow extensions, the one running into the Castlesemple valley to near Howood, Renfrewshire, where it is separated from the central Scottish basin by a narrow ridge of trap. The other angle also extends into Renfrewshire, by the Lugton valley, to Shelford, where another ridge of trap separates it from the carboniferous strata of the Levern valley, the breadth of the trap being about two miles. On the south it is separated from the main Ayrshire basin by a very large greenstone dyke, which causes a displacement of the strata to the extent of nearly 200 fathoms. It is surrounded on two sides by hills formed of trap and volcanic ash, the latter predominating in their base, the former near their summits. A very characteristic bed of ash, found in the base of the hills, extends beneath the lower limestone, and is found to occur wherever the limestone is seen cropping out towards the trap hills. Some of these ash-beds have a thickness of 30 feet, and are of an amorphous character; others have a regularly stratified appearance. Sections of them are to be This 250-word extract was created in the absence of an abstract