^{page 542 note 2} Q.J.G.S. 1874.

^{page 542 note 3} Proc. Liverpool Geol. Soc. 1894–5 and 1895–6.

^{page 543 note 1} Q.J.G.S. 1884.

^{page 543 note 2} Nature, vol. xl, p. 246.Google Scholar

^{page 543 note 3} Q.J.G.S. 1883, vol. xxxix, pp. 83–132.Google Scholar

^{page 543 note 4} See Davies and Reade, Proc. Liverpool Geol. Soc. 1894–5. Reade, “Drift Beds of Moel Tryfaen”: Ibid.., 1892–3; etc.

^{page 544 note 1} I had the pleasure of showing this to several well-known geologists during an excursion of Section C of the British Association—Liverpool meeting, 1896.

^{page 544 note 2} See “Geology of the Vale of Clwyd” (McKenny Hughes): Proceedings of Chester Society of Natural Science, No. 3. Also, “Drifts of the Vale of Clwyd”: Q.J.G.S. 1887, p. 80.

^{page 544 note 3} Mackintosh, , Q.J.G.S., vol. xxxviii, p. 184.Google Scholar

^{page 544 note 4} Prestwich, , Darbishire, R. D., Geol. Mag. 1865, p. 293.Google Scholar

^{page 545 note 1} “On the Discovery of Marine Shells in the Drift Series at High Levels in Ayrshire”: British Association, Section C, Liverpool Meeting, 1896.

^{page 545 note 2} The Baron's Stone of Killochan is a well-known example, and, according to Geikie, contains 480 cube feet.

^{page 546 note 1} These deposits have been often visited and described, but the most detailed account of them will be found in the Proceedings of the Liverpool Geological Society, Session 1892–3.

^{page 546 note 2} Memoirs of Geol. Survey—Mold, Flint, and Ruthin, p. 139.

^{page 546 note 3} Q.J.G.S. 1892.

^{page 546 note 4} Marine shells are recorded from Bacup, Lancashire, 800 feet above sea-level, which appear to have come from Boulder-clay.–Bolton, H., Trans. Manchester Geol. Soc., vol. xxi, pp. 574–6.Google Scholar See also Roeder, Ibid., 607–19.

^{page 546 note 5} “Dublin and Wicklow Shelly Drift”: Proc. Liverpool Geol. Soc., Session 1893–4. Mr. Joseph Wright, F.G.S., records the occurrence of marine Boulder-clay in Divis, co. Antrim, at between 1,300 and 1,400 feet.—Proc. Belfast Nat. Field Club, 1894–1895 (2), iv, pp. 215–6.Google Scholar

^{page 546 note 6} “Notes on the Superficial Deposits of North Shropshire”: Geol. Magazine, November, 1896, p. 482.

^{page 547 note 1} Professor Bonney has lately given an excellent résumé of the whole subject in his interesting book, “Ice-Work, Present and Past.”

^{page 548 note 1} Since this was written I have had the pleasure of reading Sir Wm. Dawson's “Canadian Ice Age” (Montreal, 1893), which renders clear many phenomena I have observed in Britain on which I could previously only surmise.

^{page 548 note 2} The following is the substance of what I said:—“In working out this objection the supporters of the Irish Sea Glacier unconsciously minimise the quantity of High-level Shelly Drift; there is much more in existence than they have persuaded themselves to believe. There is no occasion for me to name the localities over again, as I have stated them at the commencement of this paper. Again, it can hardly be expected that all High-level deposits laid down by the sea should contain shells, and further it is unphilosophical to assume that all High-level drifts have been discovered. Their discovery has generally been in the nature of an accident. I fear the advocates of the Irish Sea Glacier are continually forgetting how difficult it is to prove a negative, and unfortunately the arguments are too frequently of the negative kind.”—Natural Science, vol. iii, p. 430, 1893.Google Scholar

^{page 549 note 1} See Memoirs of the Geological Survey of Scotland, Explanation of Sheet 7, p. 14.

^{page 549 note 2} In the “Scenery of Scotland” (second edition), by Sir A. Geikie, a Drift map is published in which the only shelly drift shown between the Clyde and the Irish Sea is in the extreme south-west corner of Scotland. It is evident from this that the important shelly drifts of Ayrshire were unknown at the time of publication.

^{page 549 note 3} Mr. Dugald Bell, previous to the discoveries of Mr. Smith in Ayrshire, threw such doubts upon the recorded instances of the occurrence of shells in the Drift of the South of Scotland that the stock example of Chapelhall, near Airdrie, which was supposed to prove a submergence of about 500 feet, was omitted in the last edition of Dr. James Geikie's well-known “Ice Age.” A committee with Mr. Dugald Bell as a member re-examined the locality, with a result entirely negative. This is only another instance of the futility of negative evidence, for, as we see, not long afterwards evidence of the most conclusive sort of the presence of sea-shells in natural sections open to the world were found in Ayrshire up to double the height. See “The Great Ice Age and Submergence”, by Bell, Dugald, Geol. Mag., Dec. IV, Vol II, p. 322.Google Scholar

^{page 549 note 4} In a paper read before the Geological Society of Glasgow, April, 1880, and published in its Transactions, vol. vi, pt. 2, pp. 264–276, I stated my opinion that the Scotch Till and the Low-level Marine Boulder-clay of Lancashire are continuous, and that some of the unfossiliferous Scotch Till had probably been formed under glaciers where they debouched into the sea. This is rendered far more probable now that we know that the mud of the Scotch Boulder-clay is marine.

^{page 550 note 1} See Memoir of Geol. Survey, Scotland, Explanation of Sheet 7.

^{page 550 note 2} “Illustrations of the Huttonian Theory.”