slope of the main range of the Island. The alluvial diggings at Collingwood were first discovered in this district in 1858, and in 1864 the great gold fields near Hokitika, attracted the majority of the mining population of New Zealand. Since then the field has been gradually but thoroughly explored, and more or less gold obtained in almost every part of it. The mode of occurrence of the gold admits of very simple classification dependent on the physical features of the country.

The Southern Alps which are near to the West Coast, in the latitude of Mount Cook, are continued northwards through Nelson province to Cook's straits, by the Spencer Mountains, forming a well-marked range, that defines the head waters of the streams flowing to the east, and is characterised by the line of eruption of the Mesozoic Diorites. The towns of Nelson and Hokitika are, according to this view, equally situated on the west side of the mountains; and between Blind Bay, at Nelson, and the west coast at Hokitika, a well-marked depression extends in a S. W. direction for one hundred and forty miles, separating the central range from a triangular area of mountain country, that has its northern termination at Cape Farewell, and its southern one at the Grey river. This latter district is extremely rugged, and displays a greater variety in its geological structure, than any other part of New Zealand.

Frequent changes in the formation are common in this area, from Hornblende rocks to Schist and Clay slates, while the summits of the mountains are frequently capped with outliers of the upper Secondary coal formation and marine limestones; while in the majority of the streams that radiate from it, gold is found under such circumstances as to indicate that auriferous lodes occur in rocks throughout the district. A few quartz reefs have already been discovered, such as at Moonlight Creek on the Grey river, and Waimongaroa near the Buller, and at Wangapeka and Collingwood, in the north; but as a mining field it is still practically undeveloped. The alluvial gold has, on the other hand, been very extensively worked, the yield up to the present time amounting to 2,235,591 oz. The alluvial gold occurs in well-defined “leads,” of which there are three distinct kinds, without including the local “sluicing” diggings in the valleys of the mountain torrents, already alluded to, as generally distributed throughout the area. Unlike the gold drifts of Otago, which rest on the denuded surface of their parent rocks, the auriferous gravels in the western district, as a general rule, rest on the surface of recent Tertiary rocks, of marine origin, having, in fact, been carried out of the mountains by the rivers, and deposited along a gradually changing coast line. They thus have a general distribution parallel to whatever was the western shore of the island at the time of their deposit.

The earliest formed, and most elevated of these “leads,” extend in a N. E. direction, from near Ross, where they are cut off obliquely by the sea coast, into the Nelson province, running parallel with the main range, and have already been traced as far as the high terraces near the source of the Little Grey river. They have here their greatest altitude, though still resting on the marine strata, and slope steadily to the south, till at Ross the main lead is actually beneath the present sea level, and worked by true “deep sinking.” These leads have been intersected by the more modern streams, and a second class of leads thereby formed; while the third class of alluvial workings is formed by the ancient and modern sea beaches, along which the gold has been drifted by the action of the waves and surf. These workings extend for more than two hundred miles along the coast, and as they are undergoing constant renewal they will afford a permanent source of employment.

The peculiarity of the Westland alluvial diggings that requires to be most impressed on the mind, is that, in the majority of cases, the streams have cut