The tholeiitic, columnar (Staffa type) lavas found at, and near, the base of the Tertiary lava succession on the Isle of Mull contrast markedly with overlying transitional tholeiiticalkalic Mull Plateau Group lavas, and as a result previous workers have classed the Staffa type lavas as a distinct group. The Staffa type lavas are among the most contaminated in the British Tertiary Igneous Province and have equilibrated and fractionated at shallow depths within the crust (relative to the overlying Plateau Group lavas), so obscuring the chemical identity of their parental magma. However, Staffa type lavas which are more basic than examples hitherto reported help in the elucidation of the parental magma. It is demonstrated that the Staffa type lavas were derived from a parental magma which was compositionally similar to that of Plateau Group lavas. The primary reasons for the distinctive features of the Staffa type are related to post-mantle melt generation processes, i.e. to extensive crystal fractionation and to crustal contamination at shallow crustal depths. The lavas are compositionally and temporally unrelated to the Hebridean tholeiitic magma types, the Central Mull Tholeiite type and the Skye Preshal More type.

Isle of Wight disease is, as we have seen, primarily a disease of the respiratory system, in which the organism remains localised throughout the entire course of the attack.

The effects are, however, far-reaching, and are registered in the disordered functioning of several organs, and in visible pathological changes in some of them.

The parasitic invasion has two aspects.

We have, in the first place, to consider the active injury wrought upon the host by a parasite developing and living at the expense of its body fluids. With this aspect of the question may be coupled the possibility of a definite toxic action on the part of the parasite.

In the second place, we have to consider the passive rôle of the mites in hindering or inhibiting the normal functions of the infected organs.

Before proceeding to consider the various pathological conditions, a few words on the distribution of the parasite within the host is called for.

The first petrographic description of the rocks of South Georgia was given by H. Thürach in 1890, as part of the results of the German Scientific Expedition to that area of 1882–83. He described the rocks as clay-slates interstratified with phyllite and phyllite-gneiss, with quartz-phyllite, calc-phyllite, and quartzite-slate. He also mentions a great development of interbedded schalsteine or diabase tuffs, and describes a rolled pebble of “korniger gneiss.” His phyllite-gneiss is said to contain tourmaline, apatite, and andalusite. He emphasises the great crushing and disturbance the rocks have undergone.

The theory of reciprocal figures used as diagrams of forces was first completely stated by Professor T. Clerk Maxwell, in a paper published in the “Philosophical Magazine,” April 1864. The following definition of reciprocal plane figures, and their application to statics, are there given as follows:—

“Two plane figures are reciprocal when they consist of an equal number of lines, so that corresponding lines in the two figures are parallel, and corresponding lines which converge to a point in one figure form a closed polygon in the other.”

“If forces represented in magnitude by two lines of a figure be made to act between the extremities of the corresponding lines of the reciprocal figure, then the points of the reciprocal figure will all be in equilibrium under the action of these forces.”

The demonstration of this statement is given. The conditions under which stresses are determinate, and some examples of reciprocal figures, are also given in the paper, which leaves nothing to be desired by the mathematician.

Charts, showing by Isobaric Lines the mean pressure of the atmosphere over the globe during the months of the year, may be justly regarded as furnishing the key to all questions of meteorological inquiry; for without the information conveyed by such charts it is impossible to discuss satisfactorily those questions which relate to prevailing winds, the varying temperature, and the rainfall throughout the year in the different countries of the world. It is to meet this desideratum that the Charts of Mean Atmospheric Pressure of the globe which are given with this paper are offered as the first approximate solution of this great physical problem.

Since Part I. was read in March 1868, valuable additional information has been obtained from Australia, New Zealand, Tasmania, Africa, South America, the west coast of North America, Iceland, Norway, and Sweden, and from several isolated stations in different parts of Europe and Asia. The period for the British Islands and a large portion of Europe has been extended so as to include the eleven years from 1857 to 1867.

Brachiopods are among the most common components of the Late Ordovician benthic faunal assemblages recorded in the Faraghan Mountains, Zagros Ranges, Iran. A total of 19 species referable to 16 genera are identified, including seven new species; namely Drabovia elegans, Hibernodonta bonehensis, Hedstroemina zakeenensis, Jezercia faraghani, Protomendacella multicostata, Tafilaltia dargazensis and Tafilaltia seyahouensis. Reported brachiopod assemblages are oligotaxic (2–3 species per assemblage) to monotaxic. The only exception is the medium diversity Aegiromena-Hedstroemina Association, with up to ten species, which occurs at the lower part of the A. nigerica Zone. Low diversity patterns were probably controlled by the palaeogeographical position of the region in high southern latitudes throughout the Ordovician. Paterula sp. and Iranospirifer sp. are the only brachiopods documented from the Silurian (Llandovery) Sarchahan Formation. This paper gives the first detailed report of shelly fossils from the Llandovery ‘hot shale’ of the Arabian margin of Gondwana. Most of the Katian genera, and many of their species, are shared with neighbouring high- to mid-latitude peri-Gondwanan margins, including Morocco, Spain, France, Sardinia and Bohemia.

Two Ordovician plectambonitoid genera, Alwynella and Grorudia, occur in drill core sections of Latvia in the East Baltic, and in exposures and loose blocks on the Swedish Island of Öland in the Baltic Sea. The new material confirms differences between the two taxa that are assigned herein to separate families, Alwynellidae fam. nov. and Grorudiidae Cocks & Rong, 1989. In particular, the undercut cardinalia separates Alwynella from Grorudia and indicates its proximity to the sowerbyellids. The genus Grorudia, which is externally similar to Alwynella, is more closely related to the palaeostrophomenines. A new species Grorudia morrisoni sp. nov. is established in the East Baltic. The specimens from Öland are included tentatively within the genus Grorudia due to lack of interiors. Both Alwynella and Grorudia were confined to deeper-water facies in the Baltic palaeobasin, within successions ranging in age from latest Mid (late Llanvirn) to earliest Late Ordovician (mid Caradoc).

A small fossil insect with scales on the wings and body was identified as a representative of Aphiesmenoptera from Burmese amber. The species is introduced here as Tarachocelis microlepidopterella (†). The insect is described in detail, and photos and line drawings are provided for wing venation, head, mouthparts, scales, legs and abdomen. All characters shared with primitive Lepidoptera and Trichoptera are symplesiomorphies or groundplan traits of Amphiesmenoptera. In addition, the Burmese fossil has a number of remarkable autapomorphies, giving it an appearance that deviates clearly from known families of Lepidoptera and Trichoptera. The species, representing a family of its own, Tarachocelidae, is considered a separate and unique taxon in the stem-group of Amphiesmenoptera and is provisionally placed as Amphiesmenoptera incertae sedis.*

*NB: See Note Added in Proof (Section 4).

It is a familiar experience for the teacher in charge of a class dissecting Rana temporaria to notice or have his attention directed to blood-vessels in an abnormal position or absent from the place where they were expected. Sometimes, perhaps too frequently, they are ignored; but they are of interest, not only in themselves, but also because they throw light on problems that have arisen in other lines of work. From time to time such abnormalities have been reported in R. temporaria and in other Anura, but the literature of the subject is scattered in different journals.

Latest Eocene fossil plant remains occur in concentrations within blue-grey micrite known as Insect Limestone near the base of the Bembridge Marls Member (Bouldnor Formation, Solent Group), Isle of Wight, southern England. Some of the previously reported taxa (collections in the Natural History Museum, London) are not preserved within the Insect Limestone. These (e.g., all Arecaceae (palms)) are excluded from the floral list. New non-destructive techniques have yielded additional taxonomic information. Leaves previously assigned to Ficus and Fagus are now incertae sedis. Wetland elements are abundant, particularly Typha, but also Acrostichum, Azolla, Potamogeton, Sparganium and others. Non-wetland elements are rare. Trees and shrubs included representatives of Betulaceae, Caprifoliaceae, Juglandaceae, Lauraceae, Rhamnaceae (the sclerophyllous Zizyphus), other flowering plants and several genera of conifers. There are rare specimens of possible herbaceous plants and propagules with plumes or awns, the latter possibly an early fossil record of Clematis. The common plant remains were probably derived from vegetation near a freshwater body, sometimes with slight brackish influence, whilst rarer elements were probably blown in from a greater distance. There is little evidence of plant–insect interaction; one leaf with small galls, a stem containing an insect larva and a possible association between stratiomyid flies and Typha.

Ten silicified brachiopod taxa have been recovered from the Ben Suardal Limestone Formation (Durness Group) on the Isle of Skye, western Scotland. This Arenig fauna contains a new camerellid genus, Boreadocamara, and new species of each of the orthacean genera Archaeorthis, Fasciculina, and Oligorthis. Representatives of Billingsella, Finkelnburgia, Syntrophia, Syntrophopsis, and an indeterminate orthacean have also been recovered from etched residues of the Ben Suardal Limestone. The Skye fossils show strong affinities with the Scoto-Appalachian or American faunal province, in keeping with the inferred plate tectonic position of the Durness Group along the northwestern margin of the early Palaeozoic ‘Iapetus’ Ocean.

A brief account of the stratigraphy of the Westphalian (Upper Carboniferous) of the Ayrshire Coalfield is given. Older rocks are found to be overlain by Westphalian strata of differing age in various parts of the coalfield. A correlation of the coal seams known by numerous local names in various areas of the coalfield is shown. The vertical distribution of species of non-marine bivalves is illustrated and the faunas associated with various horizons discussed. The presence of variants of Anthraconaia pulchella Broadhurst at more than one horizon is noted. The lateral distribution of species at given horizons is examined and it is shown that elements of the overall fauna of an horizon may be absent in parts of the coalfield. The occurrence of marine bands in the succession is noted and their distribution discussed. It is suggested that during the Aegiranum Marine Band incursion the northern and north-western parts of the coalfield were nearer a land mass. A new stratigraphical name, the Bogton Marine Band is proposed. The band occurs within the Upper Similis-Pulchra Chronozone.

The Late Triassic fauna of the Lossiemouth Sandstone Formation (LSF) from the Elgin area, Scotland, has been pivotal in expanding our understanding of Triassic terrestrial tetrapods. Frustratingly, due to their odd preservation, interpretations of the Elgin Triassic specimens have relied on destructive moulding techniques, which only provide incomplete, and potentially distorted, information. Here, we show that micro-computed tomography (μCT) could revitalise the study of this important assemblage. We describe a long-neglected specimen that was originally identified as a pseudosuchian archosaur, Ornithosuchus woodwardi. μCT scans revealed dozens of bones belonging to at least two taxa: a small-bodied pseudosuchian and a specimen of the procolophonid Leptopleuron lacertinum. The pseudosuchian skeleton possesses a combination of characters that are unique to the clade Erpetosuchidae. As a basis for investigating the phylogenetic relationships of this new specimen, we reviewed the anatomy, taxonomy and systematics of other erpetosuchid specimens from the LSF (all previously referred to Erpetosuchus). Unfortunately, due to the differing representation of the skeleton in the available Erpetosuchus specimens, we cannot determine whether the erpetosuchid specimen we describe here belongs to Erpetosuchus granti (to which we show it is closely related) or if it represents a distinct new taxon. Nevertheless, our results shed light on rarely preserved details of erpetosuchid anatomy. Finally, the unanticipated new information extracted from both previously studied and neglected specimens suggests that fossil remains may be much more widely distributed in the Elgin quarries than previously recognised, and that the richness of the LSF might have been underestimated.

The decomposition of white light by prismatic refraction, as effected by Sir Isaac Newton, has, for more than a hundred and fifty years, been received as a demonstrated truth by the most distinguished philosophers of all nations. Various attempts indeed have been made, both in his day and in ours, to overturn this beautiful generalization, but they have been made by persons not only ignorant of the subject, but unacquainted with the first principles of physical research.

The analysis of light by the prism is perfect, in so far as it goes, and was demonstrated by Newton in the case of spectra produced by the single refracting medium which he employed. It was left, indeed, to his successors to discover the different dispersive powers of bodies, and the irrationality of the coloured spaces, and thus to establish the principles of the Achromatic and the Aplanatic Telescopes. These discoveries presented no points of objection to the views of Newton. They were entirely of a supplementary character, and were calculated to establish more firmly his general doctrine respecting the composition of light.

The material for the observations recorded in this paper has been kindly lent to me by Mr Graham Kerr, Professor of Zoology in the University of Glasgow. It consisted of some of his beautiful series of cut embryos, and of some freshly-sectioned material which I stained specially for the purposes of the research.

The blood corpuscles of the embryo Lepidosiren are exceptionally favourable objects for the study not only of the morphology of the blood, but also of cell structure. The karyokinesis in the red corpuscles presents features of considerable interest—and the phenomena are presented to the observer on such a scale as to render them almost diagrammatic.

In the present paper I shall deal with the structure of the corpuscles and the mitotic phases in the erythrocytes, reserving for a future communication the results of studies on the origin and histogenesis of the elements.

The original specimen of the stem with secondary wood, to which the name Palæopitys Milleri was given by M'Nab in 1870, was found by Hugh Miller in a nodule half disinterred by the sea near Cromarty; its age was shown by the remains of Coccosteus decipiens in other nodules of the deposit, and by scales of Diplacanthus in the nodule containing the wood.

Quaternary deposits and landforms are an integral component of Scotland's geodiversity and natural heritage with intrinsic, scientific, educational, cultural, aesthetic and ecological values. Their conservation is founded on the assessment and safeguard of key protected areas principally for their scientific values. The evaluation of site networks for Quaternary deposits and landforms (including glacial, fluvial, coastal, mass movement, karst and cave features) has evolved since the late 1940s, culminating in the Great Britain Geological Conservation Review (GCR) site assessments undertaken principally between 1977 and the early 1990s. Significant scientific progress since then has arisen, for example, from re-investigation of existing sites and discoveries of new sites, developments in geochronology and the formulation and application of new concepts and models. Both the GCR site lists and the supporting site documentation now require updating in the light of this progress. Today there is greater emphasis on the wider, non-scientific values of geoconservation including, for example, on ecosystem services, links with biodiversity and cultural heritage, geotourism and the benefits for human health and wellbeing through improved understanding of dynamic landscapes, climate change and natural hazards. Involvement of wider public support beyond the geoscience community and fostering better integration of geoheritage within the developing nature conservation agenda, including a land systems approach, protected area planning and management, natural capital and connecting people and nature, will help further to protect our Quaternary geoheritage.

The Carboniferous tetrapod Crassigyrinus scoticus is an enigmatic animal in terms of its morphology and its phylogenetic position. Crassigyrinus had extremely reduced forelimbs, and was aquatic, perhaps secondarily. Recent phylogenetic analyses tentatively place Crassigyrinus close to the whatcheeriids. Many Carboniferous tetrapods exhibit several characteristics associated with terrestrial locomotion, and much research has focused on how this novel locomotor mode evolved. However, to estimate the selective pressures and constraints during this important time in vertebrate evolution, it is also important to study early tetrapods like Crassigyrinus that either remained aquatic or secondarily became aquatic. We used computed tomographic scanning to search for more data about the skeletal morphology of Crassigyrinus and discovered several elements previously hidden by the matrix. These elements include more ribs, another neural arch, potential evidence of an ossified pubis and maybe of pleurocentra. We also discovered several additional metatarsals with interesting asymmetrical morphology that may have functional implications. Finally, we reclassify what was previously thought to be a left sacral rib as a left fibula and show previously unknown aspects of the morphology of the radius. These discoveries are examined in functional and phylogenetic contexts.

Rowleya trifurcata gen. et sp. nov. is described from specimens discovered in coal-balls from the Union Mine of Burnley, Lancashire. It consists of slender cylindrical axes (0·3–1·4 mm diam.) branched at long intervals by anisotomous dichotomies. Often three closely consecutive dichotomies produce a lateral trifurcation in which one or both outer branches have been arrested in growth. These bear one or two pairs of vascularised tapering appendages interpreted as ‘leaves’. Main axes usually possess a tetrarch solid strand of primary xylem somewhat like certain branches of Stauropteris. Slightly smaller axes often have a triarch strand of primary xylem triangular in cross-section. Backwardly directed branches are occasionally borne above a trifurcation and opposite a pair of ‘leaves’.

Rowleya trifurcata is associated with Psalixochlaena cylindrica and Botryopteris hirsuta. Its closest affinities seem to be with Stauropteris and Psilotum.