The field relations and petrography of a number of small rock bodies occurring near Rockcliffe at the southern margin of the Criffell-Dalbeattie granodiorite are described. The evidence suggests that they were formed by the metasomatic replacement of greywacke and shale hornfelses by Na-bearing and later K-bearing solutions which preceded the ascending granodiorite magma. This metasomatic transformation brought about the development of two distinctive rock types. Equigranular quartz-dioritic rocks which generally grade into the hornfelses are regarded as the result of static metasomatic replacement of the hornfelses with no appreciable movement of the permeated rock. In contrast, rocks of similar mineralogy but occurring as sharply bounded bodies with a conspicuous porphyroblastic texture, are thought to have attained their characteristic features by a certain amount of metasomatic mobilization of the permeated material. Because of the intrusive appearance of these porphyroblastic rocks and their occurrence near the margin of the granodiorite pluton they are here referred to as “marginal porphyrites”.

The Wealden of the Weald is mainly post-Tithonian/pre-Aptian in age. The formation probably comprises the fullest non-marine record of the interval in north-western Europe, spanning most of Berriasian (Infra-Valanginian), Valanginian, Hauterivian and Barremian time. It is well suited to be the standard succession for purposes of direct correlation.

The term “ Wealden ” should, if used for beds outside the English basin, be applied only to those non-marine formations (1) clearly lying within the Berriasian–Barremian range and, if possible, (2) correlatable directly with the standard. Otherwise “ Wealden facies ” should be used.

Beds claimed as “ Wealden ” elsewhere in north-western Europe are examined in this light.

Five bodies with either visible or inferred mineral zoning occur in the serpentinite mass in Glen Urquhart. Their mineralogy and petrology suggest a hydrothermal origin, and they are grouped with other hydrothermal injection phenomena in the glen thought go be phases of Older Granite activity. The two northern bodies seem clearly similar to simple vein deposits characterized by albitite without excess alumina (corundum). The origin of the remaining three bodies is discussed and the view that they too are deposits of albitite-type is favoured. They lack an exposed albitite zone, but this does not invalidate the comparison. Albitite deposits, it is suggested, originate where moving hydrothermal solutions from granites cut ultrabasic rocks. This origin for the veins is preferred to Larsen's (1928) suggestion that the hydrothermal veins represent late-stage sodic residual liquids left after the crystallization of most of the material of “ ultrabasic magmas ”.

There are wide divergencies between the views of different authors as to the correlation of the Jamaican Cretaceous rocks, the extreme views being (a) that the range covered is Albian to Turonian, and (b) that the rocks are mainly or wholly Maestrichtian in age.

An examination of all known occurrences of the rudist genera Barrettia and Titanosarcolites in the Antillean and Central American area suggests that the oft-repeated statement that these two genera occur in association is erroneous. In Jamaica the Barrettia Limestone lies at least 2,500 ft. below the Titanosarcolites Limestone.

Six palaeontological zones may be recognized in the Cretaceous of Jamaica, each containing its own peculiar assemblage of fossils, and with very few species common to two zones. Evidence is brought forward that only the highest part, comprising the uppermost two zones, should be included in the Maestrichtian, that the underlying shale is Campanian, that the Barrettia Limestone and associated shales are Turonian, and that the lowest zone at present known is Cenomanian.

Previous investigations of the cameral deposits of nautiloids are reviewed, with a discussion of their morphology, their distribution in shells, and growth relationships with other shell parts. Cameral deposits are developed commonly in the orders Actinoceratida, Michelinoceratida, Discosorida, and Oncoceratida. While the patterns and growth relationships of cameral and siphonal deposits are specific, and therefore of great potential taxqnomic value, the presence of such structures alone is not a valid basis for the recognition of species or genera.

Structural evidence from the Ben Lui district supports Bailey's view that the hinge of a major recumbent fold can be demonstrated there. Way up evidence indicates that all the recumbent structures from the Ben Udlaidh fold upwards face towards the south-east and south-south-east. The Ben Udlaidh and Ben Lui folds are therefore synclines. The attitude and character of the folds suggest gravitational flow.

Various aspects of the terms teschenite and crinanite are discussed, including their usage in relation to petrogenesis. It is suggested that the use of the term crinanite be discontinued.

The Maich Shell Bed of the Limestone Coal Group of the Carboniferous of North Ayrshire bears a dominantly lamellibranch fauna but includes the brachiopod Lingula squamiformis Phillips. The majority of the shells are here referred to Myalina magna (Hind). An emended description of this species is given, and its affinities with certain species of Myalina and Naiadites from the Namurian and Lower Carboniferous are discussed. The variation in the Myalina community and the distortion due to crushing are examined, and an attempt made to distinguish between them.

On Ord Ban, quartzite in superposed recumbent folds trending north–south is separated by a slide from mica-schist, granulite, and marble folded in monoclines trending east–west. The reasons for distinguishing between these two styles of folding are given, and the characters of the two styles are contrasted. A fold in quartzite and a fold in marble are described in detail, and kinematic interpretations are attempted. It is concluded that evidence of an early deformation involving mylonitization has been preserved in the quartzite, and that the latest tectonic event distinguishable was the production of the monoclines with attendant twinning of calcite and dolomite.

Petrographic and chemical study of New Zealand keratophyres, occurring in a typical spilite-keratophyre association, shows that they were originally partly glassy flow-rocks and breccias comparable with rhyolites of young volcanic areas. They are now composed of a low temperature mineral assemblage inconsistent with textural evidence of high temperature extrusive origin, and alkali metasomatism has enriched some rocks in soda and others in potash, so that their compositions are symmetrically disposed about that of a primary rhyolite magma with roughly equal amounts of the two alkalis.

Data from other occurrences suggest that this condition is common amongst described keratophyres.

Though the rocks do not originate from any special magma, the term keratophyre should be retained, with appropriate qualifiers, for old rhyolites with low-temperature mineralogy, which, incidentally, will often be found to have been affected by alkali metasomatism.

A statement by Jeffreys that the Wegener fit of South America and Africa is a misfit of 15° has been widely quoted and accepted. However, careful check by any rigorous method will show that these continents do in fact fit together as precisely as their forms can be defined. Whether continental drift be true or false, this argument against it must be abandoned.

Modal analyses of nine specimens of Ghosh's Type I and six specimens of his Type II Carnmenellis granite indicate that there is no significant difference between the average compositions of these two facies.

Thermal metamorphism of zeolites in amygdales of basaltic rocks is shown to give glomero-porphyroblastic aggregates of plagioclase crystals. Plagioclase phenocrysts in basic rocks are shown to undergo but little change during similar degrees of metamorphism.

Field observations collected on a short expedition to Jan Mayen indicate that ankaramite was extruded at three different periods at the north-eastern end of the island, either as lava flows or pyroclastic deposits. Cycles of volcanic activity, in which the earlier lavas are ankaramite and the later ones trachybasaltic, have been recognized.

One new and several re-interpreted species of Lower Cretaceous age are included in Pyrobolospora, a new organ-genus of large spores bearing neck structures; in Triletes (section Aphanozonati) are placed two other species of megaspores, one emended and one new. These are a small part of a distinctive Wealden assemblage of plant microfossils, which represents a critical period in plant evolution and which should play its part in stratigraphy. Certain difficulties in nomenclature and morphology are discussed.

Chemical and optical data are presented for a ferrohedenbergite separated from the Tertiary Meall Dearg granophyre of Skye. Comparison is made with similar pyroxenes crystallizing in the later stages of the Skaergaard intrusion.

Beds near Glynneath previously believed to be of Middle Dibunophyllum Zone (D2) age are claimed to belong to the Upper Dibunophyllum Zone (D3). These beds are described, and the implications of the position of this new locality on the Neath Disturbance are discussed.

The morphology of Cyrtograptus rigidus Tullberg n. subsp. A is described from uncompressed material. Particular attention is directed to the sequence of development of the connecting structure of cladium and main branch, which is demonstrated with the aid of figured growth stages of cleared and uncleared specimens. Also discussed is the intimate relationship of relative rate of growth of characters of cladium to those on the main branch. Cursory study of numerous other uncompressed species of Cyrtograptus in the author's collection reveals that the principles of cladial development outlined here are of general application.

Evidence from graded bedding and other sedimentary structures has shown that in the eastern outcrop of the Western Longmyndian rocks of the Shrewsbury area the stratigraphical base lies towards the east. Since in the western outcrop of these rocks the base is believed to lie towards the west, Professor Whittard's suggestion that the Western Longmyndian rocks are folded into a syncline, with the “ Oakswood Group ” representing a repetition of the “ Bayston Group ”, is accepted. The form and age of the fold are briefly discussed.

The extinct Ratnapura fauna of Ceylon is a radiation from the Indian Shivalik. In it occur a hexaprotodont hippopotamus and a race of Elephas maximus which is the most recent member of the Proboscidea. Since such an association is unknown elsewhere, it has given rise to many explanatory theories. A uranium test of associated fossils of both animals now establishes that this has resulted from redeposition and that the animals were not contemporaneous. This makes less vague the hitherto conjectural views regarding the earth movements, and the ages of the gem deposits and of the early human lithic artefacts in them.