THE Dutch edition of this work appeared in 1899, and Dr. Hinde's appendix, then issued in English, is now transferred, with its separate pagination, to the translation of the complete work. The Borneo Expedition, of which Dr. Molengraaff was the geological member, was organised by Mr. S. W. Tromp, Resident of West Borneo, in connection with the Society for the Promotion of the Scientific Exploration of the Dutch Colonies. The observations were made some ten years ago, and the author has not included references to the work of others, published since the completion of the Dutch edition. We are in possession, however, of the summary of the geology of Borneo drawn up by Dr. E. Suess in 1901 (“Das Antlitz der Erde,” 3ter. Band, pp. 308-319), and many readers have already turned to that summary for an exposition of the work of Molengraaff. Dr. Posewitz, about 1890, brought together, after three years' residence in the island, the facts then known about the geology and mineralogy of Borneo (“Borneo”; translated by Hatch, 1892), and his geological sketch-map was intended to show how large a part of the country had already been examined in a preliminary kind of way. Dr. Molengraaff, in his atlas, provides only one geological map, dealing with the parts of Central and South Borneo known to him; an enlarged map of a portion of this area follows, and the other maps prudently record the observations actually made on the banks of the rivers, which provide practically the only routes for travellers in the country. Some generalised sections and panoramic landscapes follow, the latter proving that wide views are obtainable when observers climb above the forest-zone. The fine illustrations, and plates in the volume of text reveal, moreover, many features of crag and mountain that will be new to those who think of Borneo as clothed with vegetation, amid which the rivers wander in equatorial shade.