(2) In the schist No. 4487 from Waipori two lineations are apparent in the hand-specimen; the most conspicious, b, has a trend of 170°−175°, while the fainter one, b', trends at 160°. From the ab orientation curve for muscovite (Turner, 1938a, Fig. 2, pp. 11, 112) it was established that the axis of the mica girdle approximates to b and is not related to b'. A fabric diagram based on measurement of mica in the ac section, using a universal stage, shows a girdle centred at b and thus confirms the original conclusion. (3) In the ac section of schist No. 4457 measurement of the trace of (001) in muscovite gave the lower curve of Fig. 13. The maxima at X and Y were interpreted to indicate that while the majority of the flakes lay subparallel to ab (the schistosity surface), they tended to be concentrated in planes, S1 and S3 inclined respectively at 20° and 10° to ab, rather than in ab itself. This, too, is borne out exactly by the occurrence of appropriately located maxima X and Y in the fabric diagram Fig. 14. Since the latter shows the distribution of poles of (001) as seen looking from the positive end of the b axis, points measured clockwise from the negative end of c in Fig. 14 will correspond to points on the ac curve of Fig. 13 measured anticlockwise from the positive end of a. It will be seen that there is good agreement in detail as well as for the maxima, when Figs. 13 and 14 are compared on this basis. Whether the maxima X and Y are due to the presence of two distinct s-surfaces S1 and S3, or represent curvature of a single set of s-surfaces about b has not been established. Acknowledgments. The writer is greatly indebted to Dr. Earl Ingerson, of the Geophysical Laboratory, Washington, who was kind enough to make independent measurements of quartz and mica in two of the rocks discussed in this paper. Figs. 6 and 9 have been prepared from Dr. Ingerson's results. While accepting full responsibility for the conclusions here put forward, the writer is also glad to acknowledge the benefit of critical discussion of the problem with Mrs. E. B. Knopf and with Dr. Ingerson. Literature cited. Fairbairn, H. W., 1939. Hypotheses of Quartz Orientation in Tectonites, Bull. Geol. Soc. Am., vol. 50, pp. 1475–1492. Knopf, E. B., and Ingerson, E., 1938. Structural Petrology, Mem. Geol. Soc. Am., no. 6. Sander, B., 1930. Gefügekunde der Gesteine, Vienna, J. Springer. Turner, F. J., 1936. Interpretation of Schistosity in the Rocks of Otago, New Zealand, Trans. Roy. Soc. N.Z., vol. 66, pp. 201–224. — 1938. Petrofabric Investigations of Otago Schists, No. 1, Trans. Roy. Soc. N.Z., vol. 67, pp. 443–462. — 1938a. Petrofabric Investigations of Otago Schists, No. 2, Trans. Roy. Soc. N.Z., vol. 68, pp. 107–121. — 1938b. The Metamorphic and Plutonic Rocks of Lake Manapouri, Fiordland, N.Z., Part III, Trans. Roy. Soc. N.Z., vol. 68, pp. 122–140. — 1940. Structural Petrology of the Schists of Easteru Otago, New Zealand, Am. Jour. Sci., vol. 238, pp. 73–106, 153–191.