The active volcanoes, Ngauruhoe, White Island, and Tarawera, all discharge andesitic material. The ash produced by the explosive eruption of the last-mentioned was chiefly derived from the rhyolitic rocks through which the line of vents was formed, and was, consequently, acidic in composition. Probably the large amount of rhyolitic sand brought down during Recent times by the Waikato and other rivers flowing from the Taupo region was similarly produced from older acidic rocks by the explosions of andesitic volcanoes. The loose pumiceous sands and gravels about Lake Taupo, and the unweathered rhyolitic ash found over the country eastward, were probably blown out at the same time. The andesitic cone of Mount Egmont rises from a volcanic pile of decidedly older rocks of similar composition. Its relation to the rhyolitic. rocks is nowhere shown. But on phyisographic grounds it is clearly of Recent origin; and, since its rocks are of similar composition to those of the central volcanoes, this mountain is considered to be of about the same age. The Taranaki Plain surrounding Mount Egmont is covered with tuff derived from it. In the Mokau district, about fifty miles north-east of the peak, the 120 ft. coastal terrace, which is in direct continuity with the Taranaki Plain, is formed of or veneered with similar material more or less sorted by wave-action. On the other hand, the higher coastal terraces of this district are covered with siliceous sands containing pebbles of grey-wacke, but no trace of andesitic material. The coastal drift is northward, and had Egmont been active while the higher marine shelves were being cut the detritus on them could scarcely have failed to contain some trace of volcanic material. Probably, then, the last eruption of the Taranaki volcanic centre, which presumably produced the peak of Egmont, was associated with the Recent land oscillations that produced the 120 ft. coastal terraces. Conclusion. The deposits of Pleistocene and Recent age are, in New Zealand, of greater economic importance than those of all other ages. The plains, river-valleys, and lowlands generally were formed or profoundly modified, and the soils that cover them were produced during these periods. During the same time, too, practically all the detrital gold won from the gravels of the South Island was liberated from a hard matrix and concentrated into workable deposits. New Zealand boasts of its abundant water-power, which is derived from streams that have not yet, owing to the recency of land uplift, cut their valleys to grade. And in this connection the vast mass of rhyolitic material which, ejected by Pleistocene volcanoes in the centre of the North Island, acts as a porous sponge and regulates the flow of rivers is of special interest. On the other hand, land-depression has provided harbours and valuable artesian basins in many parts of the Dominion. Literature. The official geological reports dealing with New Zealand occur scattered through various publications. A central Geological Survey was established in 1865, and the reports of the officers were issued with more or less regularity up to 1894 independently of other publications. After that date they appeared as parliamentary papers, and were bound with the volume of reports, records, &c., issued yearly by the Mines Department. The Geological Survey was reorganized in 1905, since which year, in addition to the annual report printed as a parliamentary paper, bulletins dealing