The inner or immediate trough of a glaciated valley is now generally regarded as very closely related in origin to the glacier that last flowed in it, being equally a result of its erosive work whether vertically excavated or laterally opened by it. This is the Trog of Richter (1900), which he regarded as more or less exactly containing the glacier of the last glaciation during at least a great part of the period of trough-development, though signs of overflow at the height of the ice flood are found above the “shoulders” which bound the trough. Rarely does the trough comprise the whole valley: more commonly shoulders distinctly separate steep trough walls from gentler upper valley-side slopes. In addition to the inner trough-side shoulders, however, higher benches are in many cases unmistakably present, though they may be poorly defined and are always discontinuous, so that their correlation and restoration as a definite number of actual upper shoulders is by no means certain.

Dr. R. H. Rastall (1932) has described the petrography of the Middle Jurassic sandstones of Eskdale and shown that they possess a remarkably restricted suite of detrital minerals, having for example no garnet or staurolite, but containing much anatase and brookite, both apparently of authigenic origin. The present writer (1934) showed that in other parts of North-East Yorkshire beds of the same age contain relatively rich heavy mineral assemblages. After a more detailed survey the writer was able to show (1939c, Text-fig. 2) that the peculiar restricted assemblage was confined to a belt or elongated oval area—which can be roughly defined as occupying the north-west and northeast quarters of Sheet 43 (Geol. Survey “one-inch” map) and the north-east quarter of Sheet 44—and that as one passed outward from this area one met with increasingly richer assemblages at all horizons in the Middle Jurassic.1 This result, as well as the results of mapping certain other characteristics of the assemblage, led the writer to suggest that this belt, which coincides closely with the Cleveland axis, is a belt along which active decomposition and alteration has occurred in these deposits after they were laid down.

A Recent short stay on Antigua has enabled me to inquire into a few points in the geology of that island. Among the matters of interest were to investigate the crucial question of the age of the Seaforth Limestone, which carries with it the age of the volcanic mountainous part of the island. Also to inquire into the supposed occurrence of Cretaceous Chalk at Cassada Gardens; to see some of the igneous intrusions in the Central plain and the Antigua Limestone; to collect the freshwater mollusca of the silicified tuff beds; and to search the Antigua Limestone for the so-called “Oligocene rudist”, Neomonopleura (Rothpletzia), which Dr. Lehner told me he thought occurred at Hodge's Bay. The sub-fossil land shells in the Pleistocene marls at St. George's Church also interested me, among other matters.

This paper is an attempt to review briefly the progress of geological research in an area familiar to zoologists as the classic ground covered by Alfred Russel Wallace, but which is also the field where Dutch geologists have for many years been carrying out valuable work on a much larger scale than has been possible in the smaller areas under British control in the Malay Peninsula and Borneo. There is a considerable amount of geological literature dealing with the Peninsula and Archipelago. In The Geology of Malaya (1931) is a bibliography of that concerning the Malay Peninsula, and in F. H. Hatch's translation of Posewitz's Borneo (1892) will be found lists of the earlier literature dealing with both the British and Dutch portions of that island. In the Malay Peninsula the Journal of the Straits Branch of the Royal Asiatic Society has included scientific papers since the appearance of their first number in 1878; and in 1927 C. E. Wurtzburg produced an index, including an earlier index by W. D. Barnes, of the Journal up to 1915, when the title of the society was changed to The Malayan Branch of the Royal Asiatic Society. In 1930 the Malayan Branch published an exceptionally interesting number containing a translation by H. V. Mills of Manoel Godinho de Eredia's Description of Malacca, Meridional India and Cathay, originally written about 1600 in Portuguese. This is the earliest known publication that can be called scientific about this part of Asia and contains information about tin and gold, also “traces of diamonds and emeralds as Pliny points out” which later workers have not been able to find.