Captain Bayfield, in his survey of the Gulf of St. Lawrence, discovered in several places, especially in the Mingan islands, a counterpart of the inland cliffs of St. Mihiel, and traced a succession of shingle beaches, one above the other, which agreed in their level with some of the principal grooves scooped out of the limestone pillars. These beaches consisted of calcareous shingle, with shells of recent species, the farthest from the shore being 60 feet above the level of the highest tides. In addition to the drawings of the pillars called the flower-pots, which he has published[78-B], I have been favoured with other views of rocks on the same coast, drawn by Lieut. A. Bowen, R. N. (See fig. 97.) [Illustration: Fig. 97. Limestone columns in Niapisca Island, in the Gulf of St. Lawrence. Height of the second column on the left, 60 feet.] In the North-American beaches above mentioned rounded fragments of limestone have been found perforated by _lithodomi_; and holes drilled by the same mollusks have been detected in the columnar rocks or "flower-pots," showing that there has been no great amount of atmospheric decomposition on the surface, or the cavities alluded to would have disappeared. [Illustration: Fig. 98. The North Rocks, Bermuda, lying outside the great coral reef. A. 16 feet high, and B. 12 feet. _c._ _c._ Hollows worn by the sea.] We have an opportunity of seeing in the Bermuda islands the manner in which the waves of the Atlantic have worn, and are now wearing out, deep smooth hollows on every side of projecting masses of hard limestone. In the annexed drawing, communicated to me by Lieut. Nelson, the excavations _c_, _c_, _c_, have been scooped out by the waves in a stone of very modern date, which, although extremely hard, is full of recent corals and shells, some of which retain their colour. When the forms of these horizontal grooves, of which the surface is sometimes smooth and almost polished, and the roofs of which often overhang to the extent of 5 feet or more, have been carefully studied by geologists, they will serve to testify the former action of the waves at innumerable points far in the interior of the continents. But we must learn to distinguish the indentations due to the original action of the sea, and those caused by subsequent chemical decomposition of calcareous rocks, to which they are liable in the atmosphere. Notwithstanding the enduring nature of the marks left by littoral action on calcareous rocks, we can by no means detect sea-beaches and inland cliffs everywhere, even in Sicily and the Morea. On the contrary, they are, upon the whole, extremely partial, and are often entirely wanting in districts composed of argillaceous and sandy formations, which must, nevertheless, have been upheaved at the same time, and by the same intermittent movements, as the adjoining calcareous rocks. FOOTNOTES: [67-A] Western Islands, vol. ii. p. 93. pl. 31. fig. 4.