Previously to Mr. Lyell's visit to Nova Scotia in the year 1843, it was generally supposed that the marls and sandstones containing those remarkable beds of gypsum, which have recently occupied so much attention, were both in age and position analogous to the new red sandstone of Europe. Such indeed was my own opinion (as stated in an imperfect outline of the geological structure of this island which appeared in Haliburton's ‘History of Nova Scotia,’ published in 1829), founded chiefly upon the occurrence of gypsum and brine springs in a formation bearing considerable resemblance in lithological character to the new red sandstone, without any reference whatever to its fossils, which at that period had not been examined by competent observers. Mr. Lyell, in a paper on this subject read before the Society in 1843, and more recently in his ‘Travels in America,’ has clearly shown, from their proximity to the older rocks, the great disturbances which (compared with the coal-measures) they have undergone, and more particularly from their characteristic fossils, that the gypsiferous strata of Nova Scotia and Cape Breton are the representatives of the lower beds of the carboniferous limestone of Europe; but hitherto I am not aware that any decided example of the superposition of the millstone grit and coal-measures has been observed. It affords me therefore much satisfaction to be able to furnish a section of the strata forming a lofty cliff at Cape Dauphin, the western boundary of the Sydney coal-field, where the carboniferous limestone and