of the Cairn Range. The Maitai rocks consist of greywackes and sandstones which in many places have been rendered slaty by the pressure of sharp folding. They are everywhere steeply inclined, and in the bed of the Selwyn about a quarter of a mile above the Springfield road-crossing they strike N. 40° W., with an easterly dip of 65°, while the same general direction of strike is to be found in the rocks to the south-west of the Manuka Range. The greywacke, as shown by thin sections of samples from various points, is of a very uniform type, containing a considerable amount of calcium carbonate. The rock seems everywhere considerably altered, the sections showing abundant epidote, together with much kaolin, presumably produced by the weathering of potash feldspar. The evidence available does not assist in assigning a definite age to the greywackes, but their unconformable relationship to the Jurassic rocks of the Cairn Range is discussed in a subsequent section. Map of Part of Malvern Hills District. B. Jurassic Rocks. Rocks of Jurassic age constitute the northern part of the Cairn Range from the neighbourhood of Precipice Hill to the Cretaceous outlier near Hart's coal-pit. They are again exposed on the north-western side of