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 side by wave action. Its smooth upper surface in the inter- stream areas is still strewn with wave-rolled material; and the beach, except for the work of the scoring streams, seems as in the previous case to have been exposed but yesterday.

The most extraordinary development of wave-cut terraces, now uplifted, which I have observed on the west coast of South America is that at the port of Mollendo, in southern Peru (Fig. 42). The terraces increase in height from the northern part of the Peruvian coast and reach a splendid development at this point. They are visible at sea as long, gently-sloping, rock benches of huge size. Opportunity was afforded for the more detailed examination of their upper surfaces than was possible in the preceding cases {Paita, Lomas, Pisco, Eten, etc.), and it was found that evidence for their formation by the sea and subsequent uplift to a height of at least 1500 feet is conclusive. About the inner margin of the terraces are coves like those now seen at many places on the present strand line or but a little above it. They are not so clearly distinguishable as the latter because of the partial filling or obliteration they have suffered, but their characteristic outlines are still to be made out with certainty. The whole aspect of the terraces with their regular outlines is in striking contrast to the comparatively irregular forms of the mountain side above them where there has been no planing action by the sea.

It would be a repetition of the foregoing descriptions to note the individual features of the different terraces observed along the coast farther south; and, as these have been described to some extent in the accompanying list of papers, their description here is unnecessary. At Iquique, Tocopilla, Antofagasta, and elsewhere, they are developed as clearly as in the