derms and tests of foraminifera, as well as brachiopods and algae it thickens downstream, where it includes water-worn pebbles of coal, due no doubt to the contemporaneous erosion of a seam elsewhere, for coal is found below the limestone at other localities in Hunua Range.

Sketch-map of Bell and Ardmore Creeks Scale

About a mile south of the previous contact, the basal conglomerate is admirably exposed on the right bank of Bell Creek, resting on a worn surface of greywacke (Fig. 2, Plate 1). It contains broken shells of oysters and other molluscs and a few brachiopods, and is overlain by at least 20 ft. of sandstone, with poorly-preserved marine fossils, which dips at 5° to the north-west. These exposures are 230 ft. above sea-level, so that the surface of the Mesozoic rocks rises here in a southerly direction, a fact of importance, for it throws light on the structure of the Papakura Valley depression to the north and will be referred to subsequently.

On the west side of the valley, several hundred yards due north of this second contact, beds of fairly pure limestone, apparently about 30 ft. thick, are exposed in two sinkholes now almost completely masked by a tangle of vegetation. Most of the rock has a crystalline