the Triassic beds near Nelson to the typical Maitai series, although they have frequently changed their attitude on the question. The author makes a radical departure, however, in assigning to this series the schists of the Pelorus Valley and the Marlborough Sounds as well as those of Central Otago. He says, “It is therefore true that, so far as observations go, no unconformities of any importance have yet been discovered between the Trias-Jura and the schists of Otago, though the two formations extend side by side for 200 miles. Such remarkably concordant observations show that the stratigraphical evidence almost compels one to place the Trias-Jura and the Otago schists in the same series.” Lithological evidence to support this contention is cited from Otago, and also from the schist-areas of Westland. The author points out the entire absence of fragments of schists in the conglomerates and sandstones of which the Maitai sediments are formed, although fragments of granite and other plutonic rocks are common. The palaeontological evidence, as well, is considered favourable to the contention that the sediments, and therefore in all probability the conformable metamorphic rocks, are of Trias-Jura age.

Section III of the work deals with the geological history of the country, and the special conditions under which the beds were laid down. The author is of the opinion that the thick Maitai series was laid down on a shore-line, and not in the deep sea as believed by Hutton. He explains the absence of fossils by comparing the conditions of deposition with those of a modern sandy-shore line, which is almost devoid of animal-remains.

The problems connected with the orogeny of the country are fully dealt with, and reference is made to the bearing of the recent work of the Geological Survey on this important question. The author dissents from the view insisted on by Gregory that there are two periods of mountain-folding in New Zealand, one trending north-west and the other north-east, the former occurring in north-west Nelson and in Otago. It is pointed out that in the latter case the rocks of undoubted Jurassic age are affected by this direction of folding in Otago, and therefore the folding cannot be of earlier date, it being in all probability of late Jurassic age.

The author deals briefly in various sections with the inferences that can be drawn from the character of the fauna and flora as to the climates of former geological periods. He apparently accepts Ettingshausen's determinations of our fossil plants. Perhaps, in the absence of published papers showing the extremely doubtful value of the identifications, the author was compelled to do so. However, the seeds identified as hakea, occurring in the lignites of Central Otago, should be assigned to a Podocarpus allied to P. vitensis, which suggests as equally interesting problems of land connection or the transport of seeds as if the relation was really with an Australian form.

Full attention is given as occasion demands to the history of the volcanoes in various parts of the country; the outlying islands to the south are specially referred to; and the difficult question of the Pleistocene glaciation receives careful consideration. These are sections of the subject on which the author is specially qualified by his own personal researches to speak with authority. A brief summary of the economic geology of the country is given, and the work concludes with a list of the literature which has appeared since Wilcken's catalogue was compiled in 1910, a list of the more important works dealing with New Zealand geology, and a list of the works cited in the text.

R. S.

John Mackay