Carbon replicas of coccoliths examined under the electron microscope reveal structural details which are invisible under an oilimmersion microscope, but are essential for a systematic study of these minute bodies. In an appendix, one new genus and six new species are described. Some of these appear to have a limited vertical range within the English Chalk.

An assemblage of microplankton from the Cornbrash of Yorkshire is described. It consists dominantly of dinoflagellates, including three new species of Gonyaulax and one new species of Pareodinia. A relatively small number of hystrichospheres are present, including new species of Baltisphaeridium, Cymatiosphaera, and Pterospermopsis. The character and significance of the assemblage are discussed.

The possibility of the Southern Upland Fault of Scotland continuing to the west coast of Ireland is examined critically. No post-Carboniferous faulting has occurred along this line in Ireland. It cannot be connected with any major fault occurring in the Lower Palaeozoic rocks of County Mayo or County Galway; and there is no evidence that it continues as a structural line to the south-west of Carrick on Shannon.

A basic gneiss in Ghana is traversed by light veins which are considered to have originated by replacement because gneissic mineral banding persists through them. Veins make up to 10 per cent of the rock over hundreds of square miles. It appears that a very large amount of material has been transported through the basic rocks without destroying their gneissic structure.

It is suggested that the rock-suite, characteristic of the discordant bathyliths and ranging in composition from ultrabasic to ultra-acid, is formed from two magmas, a basaltic and a granodioritic, that the basic rocks are emplaced among the geosynclinal sediments before the introduction of the acid magma, and that intermediate rocks are hybrids. Further, it is suggested that hybridization takes place in two stages: first, by reaction between basic rocks and water and carbon dioxide, released from sediments as a result of deep-seated metamorphism, and rising in advance of the acid magma; and secondly, by the magma itself. The first intrusions carry shattered country rocks and are stock-like bodies, and these are followed by successive emplacements of granodiorite, the earliest of which envelop most of the stocks and are, thereby hybridized to form tonalites. Only those stocks near the margins of the later intrusions are preserved, and hence occur as satellites about the larger more acid bodies.

The order of intrusion, the grainsize of the basic hybrids, and the occurrence of hornblende is discussed and it is concluded that dioritic rocks and dioritic magmas originate at a high level in the geosynclinal pile.

Rafts of semipelitic rock, included within a granitic body, contain segregations of microcline, biotite, cordierite and sillimanite. These structures appear to have resulted from a process of localized metasomatic rearrangement.

Contact metamorphism by a gabbro of an unusual slightly metamorphosed argillite with comparatively high magnesia and total iron has produced an olivine-bearing hornfels. The sediment is of such a chemical composition that an almost isochemical transformation is considered to have taken place. Only Mg shows any significant change from the sediment to the hornfels.

The Whin Sill of this district has the form of a series of sills at different stratigraphical levels. Minor scarps at right angles to the main trend of the sill are explained by intrusion of offshoots, from its upper surface, along low angled fractures in the superincumbent strata. An intrusion mechanism is suggested to account for the presence of the Oxford Limestone both above and below the Whin Sill.

Field evidence and theoretical arguments are used to elucidate the form of the intrusion. In the absence of a more accurate term this is described as chonolithic. Passive injection of the magma into a potential vacuum has enabled control to be exercised on the intrusion-form by the country rocks and their structures. The effects of this control are discussed.

A north-south valley west of the Malverns contains a variety of Pleistocene deposits, largely hidden by late Pleistocene solifluxion. Around Eastnor is a stony clay attributed to an ice-tongue that crossed the Malvern Hills from the Severn valley. Various sediments north of Eastnor are thought to have been laid down in a lake held up by this ice-tongue and fed by a stream diverted across the hills north of the Malverns by the main Severn valley glacier. The Upleadon Gravels south of Eastnor are attributed to water released from the lake when the ice-tongue melted. Both lake and glacier are correlated with the Woolridge Gravels and hence with the Penultimate Glaciation.