The Upper Llandeilo Rocks of the South of Scotland have long been known to yield graptolites in great profusion, few other forms of animal life being recognised as occuring in them. Having, this summer, had an opportunity of examining the graptolite-shales of Garple Linn, near Moffat, I was struck with the occurrence in them of numerous bodies, differing from the graptolites in form, though resembling them in mineral texture.

The Geological Department of the British Museum is much indebted to Dr. Cowper Reed for his careful description of the Girvan fossils which he assigns to Cornulites (Geol. Mag., Vol. LX, 1923, pp. 268–76). A slight correction, unfortunately, is necessary. Various specimens received from Mrs. Robert Gray as “Tentaculites” were registered in the Department under the numbers correctly quoted by Dr. Reed. He himself, in returning the specimens to us, pointed out, also correctly, that some of them were of quite different nature. He omitted, however, in some instances, to remove those numbers from the lists that he quoted. To prevent further confusion, the numbers to be cancelled are given below. At the same time, opportunity is taken to quote the number of the specimen that is hereby selected as the holotype of each new species. The numbers then remaining will denote the paratypes.

In the autumn of 1887, during a stay in North Cornwall, I paid a hasty visit to Tintagel, and took away a few specimens of rocks, without, however, having time or opportunity to examine more than very superficially into their field-relationships.

The subject of stratigraphical classification and nomenclature has given rise to much controversy in the literature.

Those who have made separations of heavy minerals from sands or crushed rocks will doubtless have realized that concentrates obtained by panning are not identical with those obtained when heavy liquids (usually bromoform) are used, for certain of the heavy minerals, either because of their shape or somewhat lower densities, tend to be washed away to a greater extent than zircon, rutile, etc. Yet, on account of the high cost of bromoform, panning is frequently adopted; and a compromise method of panning off most of the light material and completing the separation by means of bromoform is also used. As there is no record in geological literature (so far as I can trace) showing precisely to what extent the composition of the residue depends upon the method adopted, the following account may be of interest.

Petrographic and chemical study of biotite gneiss and charnockite and the gradational transition zone between them suggests three probable modes of origin: (i) that charnockite was regionally widespread and the biotite gneiss was derived from it by retrograde metamorphism; (ii) that the charnockite represents a conformable intrusive igneous rock which with biotite gneiss was subjected to high-grade metamorphism; (iii) that the charnockite was derived from the biotite gneiss, by the introduction of some ferrous-iron rich juvenile solution.

The latter is preferred by the author because it explains better the physical, chemical, and mineralogical characteristics of the charnockite.

Evidence is presented to show that the hornblende in the charnockite was not due to retrograde metamorphism and the conclusion is drawn that the crystallization of hypersthene is not evidence of dry conditions of metamorphism.

An excellent exposure of a Raised Beach has lately been discovered at Easington. This deposit, in my opinion, forms a part of the beds of sand, gravel, conglomerate, and breccia which are exposed along this part of the Durham coast for at least 5 or 6 miles, and which were described by me as Raised Beaches in 1905. I also consider that the upraised littoral formations were produced in late Pleistocene times.

The structure of the Jurassic area of north-east Leicestershire has been discussed by several writers, and markedly different opinions have been held. In the present paper fresh informationabout the variation of the Jurassic beds is brought forward to show the true position and orientation of the fold axes active in Jurassic times, and the history of the fold is discussed in more detail than has previously been attempted.

The Tablazos or Quaternary raised beach deposits of the West Coast of South America have attracted attention for a considerable time, as evidence of recent changes in sea-level. Early accounts of those occurring on the more southerly portion of the Continent are given by d'Orbigny in his Voyage dans l'Amérique méridionale and by Charles Darwin in his Observations on the Geology of South America. The Tablazos of Peru received considerable attention in Dr. Bosworth's work (1) and a brief sketch of the fauna was given.

The Flowers River Igneous Suite of north-central Labrador comprises several discrete peralkaline granite ring intrusions and their coeval volcanic succession. The Flowers River Granite was emplaced into Mesoproterozoic-age anorthosite–mangerite–charnockite–granite (AMCG) -affinity rocks at the southernmost extent of the Nain Plutonic Suite coastal lineament batholith. New U–Pb zircon geochronology is presented to clarify the timing and relationships among the igneous associations exposed in the region. Fayalite-bearing AMCG granitoids in the region record ages of 1290 ± 3 Ma, whereas the Flowers River Granite yields an age of 1281 ± 3 Ma. Volcanism occurred in three discrete events, two of which coincided with emplacement of the AMCG and Flowers River suites, respectively. Shared geochemical affinities suggest that each generation of volcanic rocks was derived from its coeval intrusive suite. The third volcanic event occurred at 1271 ± 3 Ma, and its products bear a broad geochemical resemblance to the second phase of volcanism. The surrounding AMCG-affinity ferrodiorites and fayalite-bearing granitoids display moderately enriched major- and trace-element signatures relative to equivalent lithologies found elsewhere in the Nain Plutonic Suite. Trace-element compositions also support a relationship between the Flowers River Granite and its AMCG-affinity host rocks, most likely via delayed partial melting of residual parental material in the lower crust. Enrichment manifested only in the southernmost part of the Nain Plutonic Suite as a result of its relative proximity to multiple Palaeoproterozoic tectonic boundaries. Repeated exposure to subduction-derived metasomatic fluids created a persistent region of enrichment in the underlying lithospheric mantle that was tapped during later melt generation, producing multiple successive moderately to strongly enriched magmatic episodes.

During the investigation of certain water-soluble and porous materials it was necessary to produce thin sections showing their structure and crystal composition. Using water as a lubricant during the thinning of the sections the specimens tended to break up and essential constituents were lost through solution, while paraffin had a marked solvent action on the Canada balsam cement resulting in disintegration of the thin section and contamination by particles of carborundum.

In its upper reaches the River Rheidol flows south, parallel to the coast of Cardiganshire, and about ten miles inland. At Devil's Bridge it turns sharply to the west (Text-fig. 1) and enters the sea at Aberystwyth. Due to rejuvenation the river has, in its southward course, incised the floor of its old mature valley the form of which is still clearly visible, and which continues to the south beyond Devil's Bridge to Pontrhyd-y-groes and Tregaron. This part of the valley now contains only small streams.

Since the publication of the Third Eeport on Palæsozoic Phyllopoda (Brit. Assoc. Eeport for 1885), we have examined many additional specimens in the Museums of the Edinburgh and Glasgow Universities, and in the Braidwood Museum belonging to Dr. J. R. S. Hunter, of Braidwood, near Glasgow. Mr. James Thomson, F.G.S., has given us a quantity of nodules, containing remains of Ceratiocaris, from the Lesmahago district; and other friends have lent us several interesting specimens.

This paper deals with the species which are considered to belong to the genus Cymbites, and the reason for placing Paroniceras, Bonarelli, as a synonym. A few notes are added concerning Agassiceras, which is also affected; and a description of the little-known species Agassiceras Colesi (J. Buckm.) is given.

Tony Hallam's contributions to mass extinction studies span more than 50 years and this thematic issue provides an opportunity to pay tribute to the many pioneering contributions he has made to this field. Early work (1961) on the Jurassic in Europe revealed a link, during the Toarcian Stage, between extinction and the spread of anoxic waters during transgression – the first time such a common leitmotif had been identified. He also identified substantial sea-level changes during other mass extinction intervals with either regression (end-Triassic) or early transgression (end-Permian) coinciding with the extinction phases. Hallam's (1981) study on bivalves was also the first to elevate the status of the end-Triassic crisis and place it amongst true mass extinctions, changing previous perceptions that it was a part of a protracted period of turnover, although debates on the duration of this crisis continue (Hallam, 2002). Conflicting views on the nature of recovery from mass extinctions have also developed, especially for the aftermath of the end-Permian mass extinction. These discussions can be traced to Hallam's seminal 1991 paper that noted the considerable delay in benthic recovery during Early Triassic time and attributed it to the persistence of the harmful, high-stress conditions responsible for the extinction itself. This idea now forms the cornerstone of one of the more favoured explanations for this ultra-low diversity interval.