The study of the materials from these two recently discovered occurrences has added much to the knowledge of meteorite craters. The two present many points in common and they supplement one another. At Henbury there is a much better development of the meteoric iron, while at Wabar the silica-glass predominates.

The accurate analysis of an igneous silicate rock is a task beset with difficulties and one which, on account of the very complete analyses now required by petrologists, involves the expenditure of a considerable amount of time. The advantages which accrue from the performance of quantitative analytical operations on the micro-scale are becoming more and more apparent, and the application of at least semi-micro-analytical methods to rocks was thought to have profitable possibilities, particularly in the way of hastening the analyses.

Specimens of quartz-muscovite-schist obtained fro: boulders in the Shotover river, western Otago, New Zealand, ere recently examined by the writer and found to contain abundant piedmontite, a mineral not previously recorded from New Zealand. The specimens had been collected twenty years before and were labelled ' micaceous quartz schist coloured with haematite' in the geological collections of the Otago University. The following description is submitted pending further field investigations.

Though calcium hydroxide has long been known as a product of hydrolysis of Portland cement, reliable data on its physical and optical properties were not available until Ashton and Wilson prepared this substance artificially and had examined crystals developed in rugs in old cement briquettes. In examining some recently collected larnite-spurrite-rocks from Scawt Hill the writer observed crystals now shown to be Ca(OH)2 as constituents of aggregates composed mainly of coarsely grained afwillite, forming infillings in these contact-rocks.