The ultrabasic rocks of the southern portion of the Early Tertiary Cuillin Igneous Complex, Isle of Skye, are recognised as forming a Peridotite Series s.l. and have been separated into six distinct structural–lithological units. These units range from almost pure dunite (Unit 1, at the lowest structural level), through to feldspathic peridotites and allivalites (Units 5 and 6, at the highest structural levels). Detailed field and mineralogical studies indicate that both cumulus and postcumulus processes involving ultrabasic (picritic) magmas may be identified, and that the latter processes have significantly modified many of the primary features of these rocks.

Layering, both modal and phase, is present within all six units, although it is more prominent within the higher units, especially Units 5 and 6. Differing orientations of fabrics defined by cumulus spinel and intercumulus plagioclase layers within Unit 3 indicate the important role of compaction and intercumulus melt migration. Unit 4 is extremely heterogeneous, involving material ranging in composition from peridotite to allivalite, and provides clear evidence for postcumulus melt movement, magma-mixing, disruption and brecciation. Units 5 and 6 developed with a more porous cumulus framework, giving rise to dendritic growths involving cumulus olivine and poikilitic plagioclase.

It is concluded that postcumulus melt movement, injection and magma-mixing, involving ultrabasic magmas, were significant processes in the formation of the ultrabasic rocks of the Cuillin Igneous Complex.

The original, plan of the Shackleton Expedition, had it been realised, would have yielded geological results of no little value. The base would have been on Coats Land, and next in importance to crossing the Antarctic continent was the projected geological sledging trip across the Wilhelm Barrier, westwards from the head of the Weddell Sea to the southern. continuation of Graham Land. Had it been carried out, it would of course have settled finally the relationship of Graham Land to the rest of Antarctica. The besetment and destruction of the Endurance, however, put an end to the original plan, and no landing was ever made either on the eastern or on the southern side of the Weddell Sea.

A Summary is given of the field relations, geographical distribution and petrography of twenty-nine dolerite plugs associated with the Tertiary lava plateau of north-east Ireland. All but two of the plugs are composed of olivine dolerite. The exceptions are a pyroxene-rich dolerite and a tholeiitic type containing abundant chlorophæite. Trace-element determinations have been made on specimens from thirteen of the plugs.

Slight but definite chemical differences are shown to exist between the olivine-dolerites and the average Tertiary olivine-basalt lava of the area. The petrogenetic relationships of the two are briefly considered.

The 1800 km-long Aleutian archipelago represents a model ecosystem to track human–environmental interactions across space and through time. Defining the southern margin of Beringia across which much of the early peopling of the Americas occurred, the Aleutians present a 9000 year record of human occupation in the eastern part of the island chain, and more than 3000 years in the west. Molecular evidence demonstrates: (1) that Aleuts shared common ancestry with Chukchi and Siberian Eskimos of Chukotka; (2) the original patterns of migration into the Aleutian islands were from the Alaskan peninsula in a westward direction with no evidence for island-hopping from Kamchatka; and (3) a highly significant statistical relationship between geography and genetics, based on mtDNA sequences, was observed despite previous population disruption. Historically, the Aleutian region is a rich ecotone, with ocean fisheries, abundant populations of large marine mammals, thick kelp forests, complex near-shore ecosystems and intertidal zones, spawning streams, and a highly diverse avian fauna. Each of these environments and resources has been pivotal in shaping the adaptive strategies of human occupants of the island chain since the initial colonisation of the Aleutians from the Alaskan Peninsula. In turn, Holocene human immigration, prehistoric cultural adaptations and subsequent historic events have had reciprocal impacts on the natural systems of the Aleutians.

Seven new species and one new genus of the family Haplolepidae (Actinopterygii: Palaeonisciformes) are described from new material obtained from the Drumgray coal shales, North Lanarkshire: Westphalian A (Bashkirian): Protohaplolepis isabellae; Protohaplolepis limnades; Protohaplolepis traquairi; Parahaplolepis alexandrae; Parahaplolepis elenae; Pyritocephalus youngii and Millerolepis eleionomae. The discovery of these new taxa increases the number of haplolepid species found in Europe to 16, thus producing a faunal count more than comparable to that of North America. This high concentration of haplolepid remains in limnic deposits is also a strong indication that these fish were not only adapted to a coastal paralic basin, but also well-adapted to a freshwater brackish environment. A comprehensive description of the skull roof morphology, including a short description of some of the larger dermal bones, is given of seven new haplolepid species obtained from the coal shale tips at Wester Bracco and Shotts in North Lanarkshire. In consequence, a revised table of the stratigraphical distribution of the Haplolepidae in Europe is provided. Furthermore, the new genus Millerolepis is assigned to the subfamily Parahaplolepinae and the generic position of the problematic Haplolepis attheyi from Newsham, Northumberland is discussed, with the taxonomic position of Protohaplolepis proposed.

Foliated to massive hornblende and biotite-bearing tonalite, trondhjemite and granodiorite comprise a terrane of batholithic dimensions in southwestern to central Newfoundland. These rocks intrude and include Ordovician ophiolite fragments and metasedimentary rocks of Fleur de Lys type, and are cut by a suite of Silurian gabbro-diorite and norite and Siluro-Devonian (?) granite intrusions.

A U/Pb (zircon, sphene) age of 456 ± 3 Ma (2σ) and a K/Ar (hornblende) age of 455 ± 14 Ma (previously reported) for a representative least-deformed tonalite of the Southwest Brook Complex indicate that it crystallised and cooled in Caradoc time. A less precise U/Pb (zircon) age of 428 ± 41 Ma (2σ) is measured for tonalitic Cape Ray Granite in southern Newfoundland. On discrimination diagrams which use Rb, Nb and Y contents to infer tectonic setting, these rocks fall in the field of volcanic arc granites. The occurrence of zircon cores with average ages of 1430 + 18/–17 and 1541 ± 173 Ma (2σ) also indicate that the magmas formed in part by partial melting of Proterozoic crust, or sediments derived from such crust. It is suggested that the tonalitic magmas were generated during the Taconic Orogeny in an arc: continent collision zone at the ancient margin of eastern North America.

Tonalitic rocks in western Newfoundland broadly correlative in age and chemistry with the batholith include the Burlington Granodiorite and Hungry Mountain Complex, as well as allochthonous slices of foliated tonalite emplaced over Ordovician platform carbonates W of Grand Lake.

(39.) A machine working by expansive power consists essentially of a portion of some substance to which heat is communicated, so as to expand it, at a higher temperature, being abstracted from it, so as to condense it to its original volume, at a lower temperature. The quantity of heat given out by the substance is less than the quantity received; the difference disappearing as heat to appear in the form of expansive power.

The heat originally received by the working body may act in two ways: to raise its temperature, and to expand it. The heat given out may also act in two ways: to lower the temperature, and to contract the body. Now, as the conversion of heat into expansive power arises from changes of volume only, and not from changes of temperature, it is obvious, that the proportion of the heat received which is converted into expansive power will be the greatest possible, when the reception of heat, and its emission, each take place at a constant temperature.

In a Lepidosiren embryo of stage 20 (Graham Kerr) the mesoderm stretches continuously through the head and trunk regions. In the trunk the dorsal mesoderm is segmented into myotomes, but the segmentation stops short some distance behind the auditory vesicle, leaving unsegmented mesoderm in front of this. In both head and trunk the lateral plate mesoderm is still connected with the dorsal, myotomic or somatic portion.

This research was undertaken as an endeavour to build up a method of discrimination of magnetic lattices in crystalline substances. Theory, due to Professor Peddie, hereafter referred to and expanded in detail, gives an estimate of the intensity of Magnetisation in a co-directed system of regularly arranged magnetic doublets, such as we may regard a magnetised piece of crystalline substance to be composed of.

When a magnetic field is applied to a crystalline portion of matter it is magnetised, not necessarily in the direction of the field, as would be the case if the substance were purely amorphous, but in general in some direction inclined to that of the magnetising field. This is due to the crystalline quality of the body, and the consequent internal inter-polar magnetic reactions. The saturation intensity of magnetisation in any plane is constant, but its obliquity to the field varies with the orientation of the field in the substance. The external field is assumed to be strong enough to co-direct all the molecular magnets; that is, to produce saturation.

This present revision of Bohemian Ordovician illaenid trilobites of the Prague Basin (Czech Republic) follows the recent evaluation of their systematic position. This revision contains redescriptions and illustrations of the type species of several illaenid genera, the most up-to-date references for those genera, and an assessment of their variability and also of the palaeobiogeographic distribution of some illaenid genera. Bohemian illaenids in several cases include the type species of globally distributed taxa, whose distinction has often been uncertain and controversial. The validity of the genera Zbirovia Šnajdr, 1956 and Zdicella Šnajdr, 1956 is discussed and confirmed. The genus Alceste Hawle et Corda, 1847 stays in open nomenclature. In Ectillaenus katzeri katzeri (Barrande, 1856) allometric growth is described and Vysocania Vaněk & Vokáč, 1997 is considered to be a junior synonym of Stenopareia Holm, 1886.

La Scotia a rapporté de son expédition au pôle sud une très importante collection d'Holothuries; nous remercions bien vivement M. W. S. Bruce de l'honueur qu'il nous a fait en nous en confiant l'étude.

Cette collection ne renferme pas moins de trente-quatre espèces, dont vingt et une, c'est à dire près des deux tiers, sont nouvelles. Cette proportion aurait été probablement plus grande, mais par suite de l'action de quelques agents conservateurs employés (formaldéhyde et acide acétique glacial) certains échantillons sont indéterminables: leurs corpuscules calcaires ayant été complètement dissous par les liquides acides. Pour la même raison nous avons décrit quelques nouvelles espèces sans pouvoir fournir daus la diagnose les caractères de leurs spicules. Mais la majeure partie des exemplaires et surtout ceux de grandes profondeurs sont en bon état et très bien préparés.

An in situ magnetic susceptibility survey of Unit 10 of the Eastern Layered Intrusion of the Isle of Rum, in a line perpendicular to the strike, was carried out as a guide to selecting sampling sites for subsequent laboratory magnetic studies. These laboratory studies indicate that the dominant magnetic phase is magnetite. An effective particle size of the magnetite was derived from the magnetic data: it was found that high concentrations (∼0·3%) of magnetite in the perioditites were achieved by the presence of fewer but larger particles. The regions of lower magnetite concentration (∼0·01%), which are mainly in the plagioclase-rich rocks, contain more abundant but smaller particles.

The variations in magnetic properties correlate with the abundance and inferred temperatures of formation of hydrothermal alteration minerals in the rocks. Petrographic observations indicate temperatures of alteration of 500–800°C in the olivine-rich peridodites in the lower part of the Unit, but of the order of 300°C in the plagioclase-rich rocks at the top of the Unit.

These relationships between magnetic mineralogy and hydrothermal alteration suggest that the magnetite was produced by olivine oxidation during hydrothermal alteration. It is proposed that variations in the magnetic properties of layered cumulate rocks may be used to map out variations in the temperature and intensity of hydrothermal fluid flow. The variations in the Unit 10 rocks studied are interpreted as indicating control of high-temperature hydrothermal fluid flow through them by contrast in permeability between brittle peridotites and quasiplastic plagioclase-rich rocks.

The Tealliocaris and Crangopsis previously recorded from Foulden are shown to be Bairdops elegans and Belotelson traquairi, respectively. This locality thus yields the oldest Known Bairdops. The two species are confined to the lower Carboniferous sedimentary basin S of the Southern Uplands massif. Elsewhere, these genera are thought to characterise the nearshore marine fauna. The reciprocal relationship noted between malacostracans and actinopterygians may therefore be a function of fluctuating salinity.

Textural relations and chemical zoning of cordierites in granites act as sensitive recorders of the conditions of their crystallisation history and underlying magma chamber processes. In this contribution, we present new data on texturally distinct and variably zoned cordierites from the late-Devonian, granitic South Mountain and Musquodoboit Batholiths, and infer the conditions of their formation. Using a combined textural (grain size, grain shape and inclusion relationships) and chemical (major element composition and compositional zoning) classification, we recognise the following six cordierite types: CG1/TT1, anhedral to subhedral macrocrysts with random inclusions and patchy normal zoning; CG2a/TT2, euhedral to subhedral macrocrysts with random inclusions and normal zoning; CG2b/TT2, euhedral to subhedral macrocrysts with random or oriented inclusions, and oscillatory zoning; CG3a/TT3, subhedral to euhedral microcrysts with no inclusions and reverse zoning; CG3b/TT4, euhedral macrocrysts with no inclusions and no zoning; and CG4/TT5, anhedral macrocrysts with random inclusions and normal zoning. The textural criteria suggest that these cordierites formed as a product of cotectic crystallisation from a melt, or as the result of a peritectic reaction involving country-rock material. The combined chemical and textural criteria suggest that: (1) normal zoning results from cotectic crystallisation during cooling, cotectic overgrowths on grains formed in a peritectic reaction with country-rock material, or cation exchange with a fluid; (2) oscillatory zoning results from cotectic crystallisation during variations in XMg of the silicate melt following magma replenishment; (3) reverse zoning results from crystallisation during pressure quenching; and (4) the unzoned cordierite results from cotectic crystallisation under fluid-rich conditions.

The tract of land embraced in the area from which the fossils have been derived, that form the subject of the present Memoir, extends in an easterly direction from Saltcoats to Newmilns, a distance of about 19 miles. At both extremities, the Coal Measures narrow down to under half a mile wide at Saltcoats, and about a mile broad at Newmilns. The greatest width is found towards the centre of the field, where in a northeast and south-west direction it is over 12 miles broad.

Upper Cretaceous marine rocks of the Big Bend Region of trans-Pecos Texas preserve a number of marine-adapted mosasauroids. At least three unnamed taxa of basal mosasauroids are represented by remains from shaly limestones in the middle Turonian portion of the Boquillas Formation. These occur along with remains of larger derived mosasaurs referable to Russellosaurina and an undescribed tylosaurine. Derived mosasaurs from the middle to late Coniacian include the first report of Tylosaurus kansasensis outside of Kansas, T. nepaeolicus, Platecarpus planifrons, and Platecarpus aff. P. planifrons. Clidastes liodontus is found in the latest Coniacian or early Santonian part of the Pen Formation. An undescribed species of Ectenosaurus, Clidastes sp. and an indeterminate plioplatecarpine occurs in the middle Santonian to early Campanian interval of the Pen Formation. The mosasaur fauna from the Big Bend region is quite similar to that from the Smoky Hill Chalk of Kansas, a thousand kilometres to the north. We refine the position of the Cenomanian–Turonian boundary within the Ernst Member of the Boquillas Formation, based on ammonite faunas. We also corroborate previous interpretations describing the time-transgressive nature of the onset of deposition of the Pen Formation based on a west-to-east descending level of the Inoceramus (Cremnoceramus) undulatoplicatus FAD.

Sebecus icaeorhinus possessed a narrow, elevated snout and laterally compressed, serrate teeth, unlike modern crocodilians, but superficially similar to those of theropod dinosaurs. Lever arms of the mandibular adductors were generally relatively greater than those of Crocodylus niloticus. Some of the adductors and the depressor mandibulae were relatively larger than in Alligator mississippiensis. Thus Sebecus may have had a stronger bite than the modern forms examined. The form of the teeth suggests use in cutting. Some theropod dinosaurs are similar to sebecosuchians in the possession of relatively deep, narrow snouts and laterally-compressed, serrate teeth. However, the adductor structure was substantially different from that of Sebecus. The presence of muscle and tendon attachments in Sebecus suggests the adductor structure of mesoeucrocodylians is conservative and was established before divergence of the sebecosuchian and neosuchian lineages. No results presented here contradict the interpretation of sebecosuchians as land-dwelling predators.

The collection of fossil corals from British Somaliland described in the following paper was made by Mr R. A. Farquharson, M.A., M.Sc., F.G.S., Government Geologist, during his survey of the country in 1923–24.

The first known fossil coral from Somaliland was collected in 1894–95, and in 1898–99 a collection of Jurassic, Eocene, Oligocene, and Pleistocene corals was made by Mr and Mrs Lort-Phillips, Miss Cole, Mr Aylmer, Miss Gillet, and Captain Marshall, and described by Professor Gregory, F.R.S. In 1907 Mr T. W. Vaughan described some Pleistocene and Recent corals from French Somaliland. A further large collection of Jurassic, Oligocene, and Pleistocene corals was made by Mr B. K. N. Wyllie, B.Sc., and Dr W. R. Smellie, both geologists on the staff of the Anglo-Persian Oil Company, and described in 1925 by Professor Gregory.

In the fourth part of these researches, I described a new base produced by the action of sodium upon picoline, to which I gave the name of Parapicoline, because it has the same composition as picoline, although the circumstances of its formation appeared to show that it had been produced by the combination of two molecules of that substance, so that its true formula would be C12H14N2. Unfortunately, its high boiling point, and tendency to decompose when distilled, made it impossible to determine its vapour density, which afforded the only means of ascertaining whether this hypothesis was correct; and it was only assumed, because similar cases of polymerisation had been established beyond a doubt in the case of other classes of organic compounds. In the hope of obtaining a similar base of lower boiling point, and therefore better adapted to the necessary experiments, I have submitted pyridine to the action of sodium, and the results of the inquiry are contained in the following pages.

Two detailed sections through 4 km of distal alluvium of the Upper Devonian Old Red Sandstone in the Munster Basin, southern Ireland, display a limited number of lithofacies. There is little ordering of these lithofacies on a small scale but changes in the proportions of lithofacies through time define a sequence of stages of basin evolution. The depositional environments changed progressively from sheetflood dominant, via mobile ephemeral channels and floodplains to a more fixed channel–overbank system and eventually to a coastal plain. On the basis of the sedimentary record a progressive reduction in subsidence rate with time is deduced as the main control on the evolution of the basin fill. This deduction is consistent with predictions from previously applied extensional basin models, but is insufficiently refined at present to distinguish between the different models.