The North Qôroq centre consists of a number of units of syenite, all undersaturated, with later units in sharp intrusive contact with earlier ones. Chemical and mineralogical characteristics have been determined by primary crystal-silicate liquid equilibria and also later, extensive, metasomatic alteration probably involving an alkali-rich aqueous phase. Cathodoluminescence studies on feldspars, the dominant phase present, reveal the development of red-luminescing albite in all the rocks affected by a late-stage fluid phase in contrast with the blue luminescence shown by unaltered perthites. Spectral and chemical investigation of the feldspars confirms earlier views that red luminescence is caused by Fe3+, an impurity in the feldspar structure, but also indicates that, for red luminescence to be seen, the blue luminescent peak must be greatly reduced or absent. The cause of the blue luminescence is less obvious but may well be related to an oxygen defect centre. Such a centre is apparently absent in red-luminescing albites and hence not formed during growth involving late-stage fluids. The fluids evolved from highly peralkaline, undersaturated magmas and metasomatised less evolved syenites forming feldspathoids, particularly sodalite. Once equilibrium had been attained the fluid behaved principally as a passive phase on its passage through the rocks, aiding the unmixing of the alkali feldspars.

In a paper by Mr E. W. Binney on the Fossil Fishes of the Pendleton Coal Field, published in 1841, the dentary bone of Rhizodopsis is figured as the “upper jaw of a new species of Holoptychius,” to which, however, he did not attach any specific name. In the same paper its scales are also figured and referred to the same genus. Scales belonging to the same fish were afterwards figured by Professor Williamson under the name of Holoptychius sauroides, and again by Mr Salter, as those of Rhizodus granulatus. Both of these specific names occur under Holoptychius in Agassiz's general list of Ganoids published in 1843, but as they were unaccompanied either by figures or descriptions, it is really immaterial which of them, if indeed either, was applied by him to the fish in question. The authority for the term “sauroides” as applied to the common species of Rhizodopsis, the only species of the genus which is as yet known with certainty, must therefore remain with Professor Williamson. Holoptychius sauroides of Binney and of Messrs Kirkby and Atthey is quite another fish, now also distinguished generically as Strepsodus, and for it the specific name “sauroides” is therefore equally valid.

The principal basic components of the Tertiary Carlingford complex are believed to have formed through the differentiation of magma of a high-alumina basaltic type. These rocks, which were once thought to be in the form of a ring-dyke, are shown to occur as a floored and multi-layered intrusion. Four major layers have been recognized. Within each, differentiation through crystal fractions settling under the influence of gravity is believed to have been the chief factor producing chemical variation. The effect of this process is seen in the compositional and modal variations of the gabbroic rocks and their constituent minerals. The variations from bottom to top of each layer correspond to a decreasing temperature of crystallization with height. At the bottoms are gabbros enriched in olivine. At the tops, the gabbros are rich in plagioclase. Throughout the layers, the plagioclases are transitional between the high and low (temperature) structural states. The resemblance of these rocks to other layered intrusions (e.g. Rhum, Bushveld, etc.) is taken as proof of the magmatic origin of the Carlingford layered basic rocks.

The base of the lowest layer is in contact with Silurian sediments and Tertiary basalts. The sediments have been intensely metasomatized with reciprocal contamination of the gabbro immediately above. Greater extremes of metasomatism and mobilization are seen in the sedimentary xenoliths which occur within the gabbros. At the base of the topmost layer of gabbro, a horizontal screen of highly metasomatized Silurian sediments separates that gabbro from the one below.

Microstructural features of eurypterid cuticles are analysed from a biomechanical viewpoint: some fibrous elements are now considered to resemble the macrofibres of extant arthropod cuticles; possible preferred orientation zones in Mycterops are related to directional stresses; pore canals are not viewed as acting as crack-stoppers but laminae (sensu Dennell 1978) may have served this function. Could some eurypterids have walked on land?—this problem is approached by using extant Limulus as a model. It leads on to the use of scaling exponents to determine the limits that possessing an exoskeleton places on the size of land arthropods: moulting may be the limiting factor. Possible critical factors limiting the size of aquatic arthropods are discussed briefly.

Sediments, mainly sandstones, conglomerates and shales, accumulated in small turbidite fans along the northern arc–trench margin of the Iapetus Ocean from middle Ordovician to Silurian time. These fans, together with the underlying pelagic facies and part of the oceanic crust, were sliced and accreted northward resulting in the Lower Palaeozoic accretionary prism which forms the Scottish Southern Uplands and the Longford-Down inlier in Ireland. North Down is the continuation of the Northern belt of the Southern Uplands of Scotland into Ireland, bounded to the S by the Orlock Bridge fault. Lithological and petrographical comparison with the rest of the Northern belt indicates closer affinities with the Southern Uplands of Scotland than with the western end of the Longford-Down inlier. Major ENE—WSW-trending Caledonian strike faults define five blocks, in which new formations of Caradoc and ? Ashgill age are defined. Pillowed spilitic rock, interpreted as a fragment of the ocean-floor, is only recognised in the Ballygrot block. Pelagic and hemipelagic black shales and cherts are overlain by arenaceous sediments in all blocks.

The term intermedio-lateral tract was introduced in 1859 (Phil. Trans., 1859, p. 445) by Lockhart Clarke to designate a tract or column of nerve cells in the spinal cord, which he had previously described in 1851 (Phil. Trans., 1851, ii. p. 613) as occupying that portion of the lateral margin of the grey matter which is intermediate between the anterior and posterior cornua. According to Clarke's original account, the column in question was very transparent in appearance, and resembled somewhat the substantia gelatinosa of the posterior horn. It was found in the upper part of the lumbar enlargement, extended upwards through the dorsal region, where it distinctly increased in size, to the lower part of the cervical enlargement. Here it disappeared almost entirely. In the upper cervical region it was again seen, and could be traced upwards into the medulla oblongata, where, in the space immediately behind the central canal, it blended with its fellow of the opposite side. In the more complete account of the tract published in 1859 (p. 446), its component cells are described as in part oval, fusiform, pyriform, or triangular, and as being smaller and more uniform in size than those of the anterior cornua. In the mid-dorsal region, where they are least numerous, they are found only near the lateral margin of the grey matter, with the exception of some cells which lie among the white fibres beyond the margin of the grey substance. In the upper dorsal region the tract is larger, and not only projects further outwards into the lateral column of the white fibres, but also tapers inwards across the grey substance, almost to the front of Clarke's column. In the cervical enlargement it gradually disappears, although it seems to contain, in part at least, a few scattered cells resembling those of the intermedio-lateral tract of the dorsal region. In the upper cervical region, as already stated, it is again seen occupying a lateral horn similar to that found in the dorsal region. It is composed of the same kind of cells, and can be followed up into the medulla, where it is said to give origin to some of the fibres of the vagus and the spinal accessory.

In the recently completed and formally ratified new series and stage classification of the Ordovician System, the base of the Middle Ordovician Series coincides with the base of the global Dapingian Stage. In the Global Stratotype Section and Point (GSSP) of this stage, which is located at Huanghuachang in southern China, the base of the Dapingian Stage is defined as the level of first appearance of the conodont Baltoniodus triangularis. The fact that this species, along with some other taxa present at the Dapingian GSSP, occurs in many sections in Baltoscandia makes it possible to recognise with considerable precision the level of this global stage boundary in Sweden, Estonia, northwestern Russia, and Denmark. In several, but not all, regions, especially in the East Baltic, the global stage boundary coincides with the base of the regional Volkhov Stage and can be tied to the base of the Megistaspis polyphemus Trilobite Zone. The regionally somewhat different relationships between the position of the global stage boundary and a very widespread hardground complex are probably due to the occurrence of local and/or regional unconformities in the upper Floian–lower Dapingian interval. Although biostratigraphically important graptolites are present in the study interval in some Baltoscandic sections, the precise graptolite correlation of the base of the Dapingian Stage remains somewhat unclear, although it appears to be near, or at, the base of the Isograptus victoriae victoriae Zone (Ca 2).

This study uses marine geophysical data, principally single-beam and high-resolution multibeam echo sounder bathymetry, combined with seismic sub-bottom profiles, and existing Quaternary geological information, to map the glacial geomorphology of a large area of seafloor (∼50,000 km2) on the continental shelf around northern Scotland, from west of Lewis to north of the Orkney Islands. Our new mapping reveals the detailed pattern of submarine glacial landforms, predominantly moraines, relating to ice sheets that covered Scotland and much of the continental shelf during the Late Weichselian glaciation and earlier in the Mid to Late Pleistocene. The reconstructed retreat pattern based on geomorphological evidence highlights the large number of different retreat stages and the asymmetric, non-uniform evolution of this ice sheet sector during Late Weichselian deglaciation. Time-equivalent ice-front reconstructions show that marine sectors of the ice sheet, such as the Minch, changed their geometry significantly, perhaps rapidly; whilst other sectors remained relatively unchanged and stable. We suggest that this behaviour, governed principally by bed topography/bathymetry and ice dynamics, led to reorganisation of the Late Weichselian ice sheet as it retreated back to two main ice centres: one in Western Scotland and the other over Orkney and Shetland. This retreat pattern suggests relatively early deglaciation of NW Lewis (ca. 25 ka BP) and the mountains of far NW Scotland – the latter possibly forming a substantial ice-free land corridor. Our reconstructions differ from most previous syntheses, but are strongly supported by the independently-mapped offshore Quaternary succession and key onshore dating constraints.

The genus Lyginorachis was proposed by Kidston (1923, pp. 18–19) to accommodate isolated petioles which, whilst their structure was similar in some respects to that in the petiole of Lyginopteris, could not be finally identified with the latter genus. Two species of Lyginorachis have been described (Scott, 1923, pp. 57-60; Crookall, 1931, pp. 27-34, pls. i-iii). Both came from Scottish Lower Carboniferous rocks; the one, Lyginorachis papilio Kidston and Scott, from the Cementstone Group (Calciferous Sandstone Series) at Norham Bridge on the Tweed, and the other, Lyginorachis Taitiana Kidston and Crookall, from the Auldton Limestone (Carboniferous Limestone Series) near Lesmahagow, Lanarkshire. Crookall also described a smaller and simpler petiole (loc. cit., pl. ii, fig. 3) as Lyginorachis sp., from the Cementstone Group at the Langton Burn, near Duns, Berwickshire.

In the Transactions of the Royal Society of Edinburgh, Vol. LIV, Part III, No. 11, 1926, the author published an account of the anatomy of the head of an African Elephant fœtus, 21 cms. in length. The present paper deals with the voluntary muscles (except those already described) of the same fœtus. The author intends to prepare later an account of the skeleton and internal organs, so that a complete description of the anatomy of this rare specimen will be available.

The section which treats of the head will henceforward be referred to as Part I; the present paper, therefore, becomes Part II.

The body muscles were investigated under the Zeiss Binocular Dissecting Microscope, and the work was facilitated by rapid staining with a weak solution of saffranin. Owing to long preservation, the muscles, nerves, and blood-vessels of the specimen were quite colourless. The saffranin gave a certain amount of differentiation which lasted for several hours, and the advantage of the method is that the colour disappears entirely when the specimen is put back into the store jar between one working period and the next.

Samples from the various horizons of five soil profiles representative of diverse types widely occurring in north-east Scotland were intensively examined, after separation into particle-size fractions, by appropriate instrumental and chemical techniques including optical examination, X-ray diffraction, electron microscopy and diffraction, infra-red absorption spectroscopy, thermal analysis procedures, chemical analysis and selective chemical dissolution. The results obtained are presented and assessed with respect to quantitative estimation of the mixed SiO2-Al2O3-Fe2O3 gel system occurring in these soils. At best results can be only semiquantitative, but interesting trends are observable in each profile and marked differences are noted between profiles on different parent materials, although this effect is somewhat obscured under impeded drainage conditions. The maturity of the soil is also a significant factor. Results in general can be explained in terms of current concepts on pedogenesis.

The vertical and horizontal distributions of important plants and animals on exposed rocky shores in Caithness are described, and comparisons are made with other shores of the British Isles. The environmental conditions which cause a marked uplift in the zonation of inter-tidal species in Caithness are considered.

In the western Midland Valley of Scotland and the neighbouring areas of the south-western Grampians and Southern Uplands, the regional Bouguer anomalies may be resolved into (i) a westerly-rising component similar to that prevailing throughout western Scotland, and (ii) a broad high over the central zone of the graben with marked decreases towards the bordering mountains.

When allowance is made for the contribution to the gravity anomalies of the light Upper Palæozoic rocks within the graben, the adjusted values outline an accentuated high over the graben with a drop of 25–30 mgal from the maximum to the northern limit of the area and with a corresponding drop to the south. In a profile normal to the major geological structure, the shape of the high approximates to a parabola with its apex 5 miles north-west of the Inchgotrick Fault.

These regional changes may best be explained by a thickening of the Upper Crustal Layer under the Grampians and Southern Uplands, most probably by the addition of thick Lower Palæozoic and Dalradian geosynclinal deposits. Thicknesses of the order of 17,000 ft., additional to those under the Midland Valley, are required to account for the gravity changes. The relative attenuation of the succession in the Midland Valley area, implies that the area of the graben was already a crustal entity in pre-Upper Palæozoic times.

The anomalies accord qualitatively with isostatic compensation of topography. The predominant high positive background values, have, however, no significance peculiar to the graben area.

The following additional remarks are the outcome of my study of the polyhedral data for tenfold knottiness, which I received from Mr Kirkman on the 26th of last January. My main object was, as in the first chapter of Part II., to determine the number of different types; as well as the number of essentially different forms which each type can assume, as distinguished from mere deformations due to the mode of projection.

This study has been a somewhat protracted one, in consequence (1) of the great number of tenfold knots; (2) of the very considerable number of distortions of several of the types, many of which are essentially distinct while others present themselves in pairs differing by mere reversion; and especially (3) of the fact that the polyhedral method often presents some of the distinct forms of one and the same type projected from essentially different points of view (of which, in the present case, there are sometimes twelve in all).

This paper reports a new assemblage from the Late Triassic (mid–late Carnian) at Woźniki near Częstochowa (Poland). The Woźniki vertebrate assemblage is similar to that of Lisowice–Lipie Śląskie, a new locality bearing vertebrates from latest Triassic (latest Norian–early Rhaetian) strata of southern Poland, in the presence of dicynodonts, shark spines, plagiosaurs and a cyclotosaur, but conchostracans and bivalves are similar to those from the Krasiejów site (late Carnian). The most complete specimen from Woźniki belongs to a dicynodont, and consists of cranial and postcranial bones of a single individual. It demonstrates that large dicynodonts were part of the Late Triassic vertebrate assemblage in Central Europe. Numerous tetrapod tracks and traces are associated with skeletal fossils at Woźniki.

The northern Colorado River extensional corridor (NCREC, USA) provides an excellent record of coeval volcanic and mid- to upper-crustal (<13 km) plutonic suites. The NCREC is a 50–100-km-wide zone that records late Tertiary lithospheric extension, volcanism, continental sedimentation and plutonism. Compilation of published studies of NCREC magmatic rocks permits an assessment of volcanic–plutonic links, magma sources and magmatic processes. The volcanic sections provide an excellent record of magma compositions (basalt, trachyandesite, trachyte and rhyolite) which span a 9-million-year period in the Miocene age (20–11 Ma).

Contemporaneous Miocene plutons span a similar compositional range (gabbro, diorite, quartz monzonite and granite) and were emplaced during a 4·5-million-year interval from 17 to 12·5 Ma. Geochemical and isotopic compositions and compositional trends allow direct correlation between plutonic and volcanic suites across the entire compositional range. Petrogenetic models demonstrate that intermediate magmas formed by a combination of magma mixing and fractional crystallisation involving mantle-derived mafic with crustal-derived felsic end-member magmas. Plutons exhibit a variety of features which suggest magma chamber processes, including (1) mafic cumulate sequences, (2) felsic cumulate sequences, and (3) magma mingling and advanced stages of magma mixing. Thus, the NCREC plutonic-volcanic record provides a link between magmatic processes recorded in pluton magma chambers and magmatic products in the form of extrusive igneous rocks. The NCREC plutons represent upper crustal magma chambers which connected volcanic eruptive centres to deeper-level magma chambers, and ultimately, to zones of mantle and crustal mel

The records of columnar shell structures of linguloid brachiopods (Class Lingulata, Order Lingulida, Superfamily Linguloidea) are reviewed in the light of the discovery of two new taxa from the Middle Cambrian Forsemölla Limestone Bed of southern Sweden. The linguloid taxa, described here as Eoobolus? sp. aff. E. priscus (Poulsen) and Canalilatus? simplex sp. nov., are both characterised by a columnar shell structure, a structural type that is representative for acrotretoid brachiopods and that has previously only rarely been reported from the linguloids. Though the two taxa are superficially similar to known genera, i.e., Eoobolus and Canalilatus, their shell structure challenges such affiliations, as the shell structure of the type species of these genera is previously unknown. Linguloid families whose morphological characteristics agree the most with those of the new taxa, i.e., the Zhanatellidae and the Eoobolidae, and from which columnar shell structures have been reported, i.e., the Lingulellotretidae and the Kyrshabaktellidae, are reviewed briefly. Many taxa assigned to these families completely lack shell structure data and are in need of restudy in order to elucidate their systematic position. Knowledge of the representative type of shell structure of the various suprageneric taxa within the Linguloidea is considered crucial, in order to unravel their currently poorly resolved phylogenetic relationships.

The Canonbie Coalfield occupies a small tract of ground between the Liddel Water and the river Esk in the south-east part of the county of Dumfries. Though of limited extent, the coalfield has aroused considerable interest, due partly to the important series of plants obtained from the beds, and partly to the questions bearing on the correlation of the Carboniferous rocks of the Scottish Border with those in the North of England and Central Scotland.

Some years ago, when studying the electrical organs of the torpedo, I was forced to the conclusion that the nerves supplying the batteries had not been accurately described, and that notwithstanding the statements in the most recent works, the first electric nerve is not derived from the trigeminus. Finding some difficulty in making out the arrangement of the cranial nerves in the greatly specialised torpedo, I directed my attention, first to the skate, and later to certain sharks, more especially to the Greenland shark (Læmargus). I had not proceeded far before I was convinced that we had still much to learn as to the anatomy of the cranial nerves of both the higher and lower vertebrates.