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The present writer dissents radically from the author's fundamental conclusions and from his estimate of the present drift of opinion, but finds the book interesting and suggestive, and its contributions to Pleistocene paleontology notably valuable.

In this bulletin, Professor Lawson presents the results of some of his studies on the west coast of California. The essay concerns itself especially 1° with the coasts of San Diego and Los Angeles counties, and with the islands of San Clemente and Santa Catalina which lie a few miles to the west; and 2° with the coastal region from Santa Cruz to the Golden Gate. So far as concerns the southern region, the data are drawn principally from four localities. These are: a) the coastal slope of San Diego county,—the San Diego mesa; b) San Pedro Hill; c) San Clemente Island; d) Santa Catalina Island.

The San Diego mesa is a terraced plain having a breadth of from twelve to eighteen miles. It is characterized as a Pliocene delta, made up principally of Pliocene sands and sandstones, but covered by a thin sheet of river gravels. The evidence for the statement that these gravels are of fluviatile origin is not given. The gravels are thought to have been deposited approximately at sea level. They now stand at a maximum elevation of nearly eight hundred feet. The inference is that an elevation of eight hundred feet has taken place along the coast of San Diego county since Pliocene time. Various marine terraces at levels of seven hundred feet and less characterize the mesa.

San Pedro Hill is an abrupt headland on the coast of Los Angeles county. Its slopes likewise show a series of marine terraces and sea-cliffs. The highest terrace on this headland stands at an elevation of 1240 feet. There are many lower terraces on the San Pedro Hill, the lowest mentioned having an altitude of 120 feet. Through the higher terraces the streams have cut for themselves cañons; but they flow over the lower terraces in shallow channels. This is evidence of the recency of the elevation marked by the lower terraces. Molluscan borings in the old sea-cliffs, up to an elevation of 1240 feet, may still be seen.

From the relations of the Miocene to the Pliocene formations of the headland, it is inferred there was an "important interval of denu-