In a paper published in the ‘Quarterly Journal of the Geological Society’ for March 1913 (Q. J. G. S. vol. lxix, p. 1), I gave an account of the Ashgillian succession in the Cautley District, Yorkshire, and stated that the development of the Ashgillian Series in the North of England is far more satisfactorily shown around Cautley than in the neighbouring areas of the Lake District and Edenside. I have described this Cautley succession ‘as one which should be taken as the type for the Ashgillian Series of Northern England.’ It is, nevertheless, desirable that one should know how this Ashgillian Series is developed in the place from which it takes its name—namely, the stream and quarry of Ashgill west of Coniston Lake,—and I accordingly devoted several weeks during the summers of 1913 and 1914 to the study of the succession in the tract in which Ashgill lies. I have been much helped in this work by my son, Lieut. F. A. Marr. The study of the rocks here is rendered more difficult than in the Cautley region, partly owing to their smaller thickness, as a result of which the fossils appear to have been largely broken before entombment, but especially owing to the great amount of cleavage, which causes much distortion of the fossils. But, after the experience gained in the Cautley region, this study has been rendered easier, and I now feel able to compare the succession of the Ashgill region with that of Cautley, though a final