The Coast-line which I am about to describe extends from the Vale of Clwyd, in Flintshire, to the Great Orme's-head Mountain at the northern end of the Menai Straits.

Although the causes of the configuration of the Lake district have been discussed by Mr. Mackintosh in some interesting communications to this Magazine, and the distribution of the granite blocks from Wastdale Crag formed the subject of an able paper read by Professor Phillips to the British Association at Birmingham, 1865, the glaciation of this region seems scarcely to have attracted the attention which it deserves. In the hopes, then, that some one may be induced to do for North Wales, I venture the following remarks; although, owing to want of time and other causes, they are far less complete than I could wish them to be.

Mr. Mackintosh (Vol. III., p. 69, and p. 155, of the Geol. Mag.) adduces the preservation of numerous terraces on the hill-sides in the Cretaceous districts of ‘Wilts. and Dorest,’ as “evidence of limited subaerial denudation since those terraces were formed,” for that they are “raised sea-beaches,” he says, admits of no doubt.

My knowledge and observation of facts are neither of them sufficient to enable me to determine the mode of deposit of these blocks in their present sites; probably they may have been glacially trnasported, at the same time with the gravel, to the places where they are now found; or, possibly, they, or some of them, may have been swept away from their original localities in the Tertiary formation, by a flood, or floods, general or partial.

The plate containing the figures of the Polyzoa here described was prepared some years since by Mr. J. De Carle Sowerby, but has never been published, and no description of the fossils themselves has as yet been given. I have, therefore, been requested by my friend Mr. Woodward to draw one up; and the specimens have been kindly placed in my hands by Mr. N. T. Wetherell for the purpose.

Examining the Cambridge sands, fresh from a remembrance of the Undercliff and the grand developement of the cherty rock of the Upper Greensand in Southern sections, perhaps its most marvellous character is that here it no longer makes a feature in the land, but has dwindled away to barely a foot in thickness, and yet is to be traced through several counties. Blending insensibly into the chalk, resembling in structure beds that sometimes occur in the Gault, it appears but as a parting seam between those deposits. Yet so soon as Dr. Fitton made clear the sequence of the Cretaceous beds, Professor Sedgwick recognised in the film of black nodules, glauconite and chalky marl, the analogue of the sands of the Vale of Wardour and the Isle of Wight.