The Creag Strollamus area lies about three miles to the north-west of Broadford, and presents in miniature all the formational and structural elements of the plutonic region of Skye.

The pre-plutonic substructure of the area consists of Torridonian, largely sandstones and grits, overthrust at low angles upon Cambrian limestones. The thrust plane has been thrown into a number of gentle folds on N.E.-S. W. axes, and has suffered displacement by faults of small throw having the same N.E.-S.W. trend. Owing to later erosion the Torridonian sediments remain as a very thin veneer over much of the area, but thicken rapidly towards the north-west.

Tertiary volcanics, very largely basalt lavas, were extruded upon a surface of considerable relief, but have now been partly removed to reveal large stretches of Torridonian. Subsequent movements included the development of a number of N.W.-S.E. or N.N.W.-S.S.E. faults, usually of small throw, as well as a general warping of the area, so that the volcanics are now inclined north-eastwards at angles around 30 degrees.

Particular attention is directed to the disposition of the sub-volcanic surface in relation to the thrust plane. In a south-easterly direction the erosion surface gradually converges on the thrust plane and ultimately, in the area of the Broadford gabbro, descends beneath it.

Gabbros form a number of masses of widely varying size, but evidently represent sheeted bodies, formerly of greater continuity. Gabbro occurs only in localities where, as considerations of structure show, the former presence of volcanics may reasonably be inferred, the sub-volcanic surface representing the downward limit of gabbro just as it limits the volcanics themselves. Within the gabbro masses internal structures can be recognised which agree with those in the basalts.

Petrographically the close relationship between gabbros and basalts is confirmed by the occurrence of grading contacts and the presence within the gabbros of relic textures and small-scale structures, including amygdales, comparable with those of the basalts. It is therefore concluded that the gabbros developed by the transformation of the pre-existing volcanic rocks.

Just as the downward limit of gabbro in the structure of the area is the sub-volcanic surface, so the granites are confined upwards by this surface and downwards by the thrust plane. Granite occurs in place of Torridonian in the pre-plutonic structure. The variation in habit of the granites from “boss-like” to sheeted in a south-easterly direction is to be correlated with this observation.

Having regard to the preservation of pre-granite structures, often of considerable complexity, it does not appear possible that the granites have been emplaced by the mechanical displacement of Torridonian. Transformation of Torridonian, essentially in situ, is therefore considered the more probable explanation. Support for this view is provided by the nature of the junctions between Torridonian and granite. These are invariably merging and show, at least on a limited scale, that granitisation has indeed occurred.

The southern Bathgate Hills, in the eastern part of the Midland Valley basin of Scotland, were the site of a volcanic rise during late Dinantian to early Silesian times and a sequence of basaltic lavas and tuffs up to 600 m thick accumulated. The volcanic pile interrupted the regional sedimentary deposition, which involved a cyclical sequence of marine limestones and mudstones followed by estuarine, lagoonal and deltaic clastic deposits. During the Brigantian Stage of the Dinantian, freshwater terrestrial environments developed locally on the volcanic rise between eruptive phases, but later in the Brigantian the rise was transgressed by marine limestones. Intermittent basaltic eruptions continued into the Amsbergian Stage of the Silesian, accompanied by intrusion of high-level alkaline doleritic sills and associated with strata-bound Zn—Pb mineralisation. Folding later in the Silesian was followed by the intrusion of a suite of quartz-dolerite sills and dykes. These latter were commonly intruded along penecontemporaneous E—W trending faults. The intrusion of the quartz-dolerites may have resulted in remobilisation of earlier strata-bound mineralisation into epigenetic veins.

The Dalradian Supergroup contains three distinct glacigenic units, formerly termed ‘Boulder Beds’, which are correlated with widespread Neoproterozoic glaciations. The oldest and thickest unit, the Port Askaig Formation, marks the Appin–Argyll group boundary of the Dalradian Supergroup and has been correlated with the Middle Cryogenian (Sturtian) glaciation. The Auchnahyle Formation, a diamictite-bearing sequence near Tomintoul in NE Scotland, exhibits strong lithological similarities to the Port Askaig Formation. Both these glacigenic ‘Boulder Bed’ units contain abundant dolomite clasts in their lower parts and more granitic material at higher levels. Both metadiamictite units are overlain by thick shallow-marine quartzite units. C isotope data from Appin Group carbonate strata below the Auchnahyle Formation support this correlation. U–Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) detrital zircon data from the Auchnahyle Formation metadiamictite differ slightly from the Port Askaig Formation, but are similar to detrital zircon spectra obtained from the Macduff Formation, a diamictite unit in the younger Southern Highland Group of the Dalradian Supergroup; both apparently reflect derivation from local basement rocks. No detritus younger than 0·9 Ga is observed, so the data do not constrain significantly the depositional age of the glacial strata. A thin tholeiitic pillow basalt unit in the lower part of the Auchnahyle Formation is geochemically distinct from pre-tectonic metadolerite sills and from basic metavolcanic rocks up-section. A Sturtian (c. 720–700 Ma) age for the Auchnahyle Formation metadiamictite would imply that this basaltic volcanism represents the oldest recorded volcanic activity in the Dalradian Supergroup and is inferred to represent an early, local phase of proto-Iapetan rifting within the Rodinian supercontinent.

Through the courtesy of Dr W. S. Bruce, the leader of the Scottish National Antarctic Expedition, and of the late Professor D. J. Cunningham, the skeletons of the seals collected in the Antarctic during the voyage of the Scotia have been placed in my hands for study, and I wish to express my gratitude to these gentlemen for their great kindness in placing all the necessary requirements at my disposal. I also wish to state that Dr Bruce has given to the Museum of the University of Edinburgh a choice of the various skeletons, which, together with the specimens already obtained, will form a comprehensive and almost unique collection of the Antarctic seals.

The establishment of Primula petiolaris and its allies as representing a distinct section of the genus was the work of Pax in Engler's Bot. Jahrb., x, 173 (1889). His definition of the section was reasonably adequate, allowance being made for the scanty material available to him. The main information at his disposal came from Wallich's diagnosis (1) of P. petiolaris in 1824 and Hooker's treatment (2) of that species and its varieties in 1882. The chief diagnostic marks instanced by Pax were the membranous leaves with very broad midrib and with sharply and closely erose-denticulate margin, the great variability in leaf-shape and in the degree of development of the scape, the rose-coloured flowers and the globose capsule. Very apposite were his comments on the difficulty in distinguishing the component species and his conviction that the many varieties of P. petiolaris may quite well represent individual species, although the lack of careful observations on living material compelled him to leave within that aggregate even such plants as P. Tanneri. Pax's conception of the confines of his section was better exemplified by his choice of its components than by his diagnosis.

Drepanopterus pentlandicus Laurie, 1892 is redescribed from the original type material along with previously unfigured specimens. A cleft metastoma is confirmed as a characteristic of the genus, along with the armature of the second and third prosomal appendages being modified into flattened blades, while the species is shown to possess a somewhat enlarged second tergite and lateral prosomal margins that overlap the first opisthosomal tergite. Different ontogenetic stages of D. pentlandicus are described, and reveal that these latter characters develop only later in ontogeny, suggesting that described specimens of Drepanopterus abonensis Simpson, 1951 may represent juveniles. Cladistic analysis of Stylonurina shows the genus Drepanopterus to be monophyletic consisting of D. pentlandicus, D. abonensis and D. odontospathus sp. nov.: it forms a basal clade of mycteropoids. Hibbertopteroidea Kjellesvig-Waering, 1959 is shown to be a junior subjective synonym of Mycteropoidea Cope, 1886, with the synonymy of many of the hibbertopterid genera hypothesised and Hibbertopterus Kjellesvig-Waering, 1959 suggested to represent juvenile specimens of Cyrtoctenus Størmer & Waterston, 1968. Hibbertopterus permianus Ponomarenko, 1985 is transferred to Campylocephalus Eichwald, 1860. The role of heterochrony in the morphological development of the mycteropoid lineage is discussed, with both hibbertopterids and mycteropids suggested to be hypertrophic and pre-displacement peramorphs respectively.

Some 40 brachiopod species are known from the localities of Kilbucho and Wallace’s Cast in the Kirkcolm Formation in the Northern Belt of the Southern Uplands of Scotland. The fauna is diverse despite the relatively small numbers of brachiopod specimens (c. 180) available for study. Much of the fauna was transported downslope and is locally preserved in obtrution deposits. It represents a broad census of outer shelf and upper slope palaeocommunities around this part of the Laurentian margin during the early Katian, and is dominated by relatively small plectambonitoid brachiopods. When compared with other circum-Iapetus assemblages, the brachiopods from the Southern Uplands compare most closely with those from the Bardahessiagh Formation, Pomeroy, Northern Ireland, rather than with adjacent, well-known faunas from the Girvan district, SW Scotland. These new data suggest that this part of the Southern Uplands was located in closer proximity to Pomeroy than Girvan, and located in deep-water environments similar to those in the upper parts of the Bardahessiagh Formation.

In the course of my studies on the Microscopic Anatomy of Lichens, during the last fifteen years, I have frequently met with various more or less minute Parasites—mostly black and punctiform or papillæform—sometimes disciform or maculæform—affecting either the thallus or apothecia of lichens, or both thallus and apothecia. They grow equally on foliaceous and crustaceous lichens, especially of the following genera:—Parmelia; Physcia; Umbilicaria; Solorina; Peltidea; Nephromium; Sticta; Stereocaulon; Usnea; Neuropogon; Cladonia; Bæomyces; Squamaria; Placodium; Lecanora; Pertusaria; Thelotrema; Lecidea; Graphis; Endocarpon; Verrucaria.

The only observations made with Dr Lloyd's bifilar magnetometer, published with corrections applied to the individual observations, are those made in the Makerstoun Observatory, forming part of the Transactions of the Royal Society of Edinburgh. The results obtained from these observations (especially from those for 1844 and 1845), were first compared by me in 1856, with observations (also corrected by myself) made in the Trevandrum Observatory during the same years. The singular resemblance of the variations of daily mean intensity thus discovered at two places so distant, and so differently situated on the earth's surface, induced me to undertake the considerable labour of determining the temperature coefficients, and of correcting and discussing all the published (and some unpublished) observations made in the colonial observatories. This labour was too great to have been undertaken by me alone, in consistence with my other duties, and it is due to the liberality of His Highness the Rajah of Travancore, that I could employ in part for this work the computers attached to his Observatory.

The author recalls the facts regarding the rediscovery, in recent years, of Carter's genus Conulites ( = Dictyoconoides Nuttall). He shows how, of seven species which have been referred to this genus, three always have numerous intercalary whorls in their spires, and four never have any such whorls. The association of these two groups together within a single genus has, so far as he himself is concerned, been due to the uncertainty hitherto existing regarding the type species cooki, whose spire was stated by Carter sometimes to show an intercalary whorl, but generally to be “single throughout.” Carter's original specimens, which had long been mislaid, have recently been found, however, and they all prove to belong to now familiar types, which invariably contain numerous intercalary whorls in their spires. The author therefore separates the four species which do not possess such whorls into a new genus, Lockhartia.

The author next discusses the supposed identity of Dictyoconoides with Rotalia, and shows that the Rotalia must be judged by their type species R. trochidiformis. He shows that this species, among other characteristic features, invariably displays the structures called “astral lobes” by Carpenter and Brady, and is distinguished by the same from both Dictyoconoides and Lockhartia; while it is further distinguished from Dictyoconoides by the absence of intercalary whorls in its spire.

The author then compares the development of Rotalid forms, like the above, with that of piano-spiral ones like Nummulites and Assilines; and he finally shows the fundamental difference in structure between all these spirally wound types and those with an “end-on” development, like the Dictyoconus group of forms, with which some of them have been confused in the past.

Like most metazoan biomineralisations, the brachiopod shell is the end product of a biologically controlled calcification process. The main agent of the control is the extracellular matrix, which is secreted by the outer mantle epithelium. This matrix mediates the calcification process by allowing crystal nucleation and elongation in specific orientations and finally, by stopping crystal growth. The proteinaceous moiety of brachiopod shell matrices has been extensively studied. Less known are the post-translational modifications that occur in these matrices, in particular glycosylations. In this comparison of five species of Recent articulated brachiopods, the ratio of soluble to insoluble organic matrix varies between the species. Polydisperse macromolecular materials occur in each of these species with discrete proteins of 50 kDa in Notosaria nigricans, Calloria inconspicua and Neothyris lenticularis, 37 kDa in Terebratulina retusa and Gryphus vitreus and 20–25 kDa in N. nigricans. Protein mixtures from all five species respond differently to anionic stains (Stains-All and Alcian Blue). PAS staining results in a positive smear in C. inconspicua and T. retusa and highlights low molecular weight glycoproteins in C. inconspicua. The polysaccharide composition of the soluble matrix of T. retusa is different from the others due to high proportions of arabinose and low proportions of fucose. In all cases, polysaccharide composition of the insoluble matrix is dominated by glucose and glucosamine. Insoluble matrices have more glucose and xylose and less galactosamine and glucosamine than the corresponding soluble matrix. Relatively high amounts of glucosamine may suggest the presence of chitin in the shell matrix of rhynchonelliform brachiopods.

This address is concerned—not, I feel, unsuitably on this particular occasion—with the two major interests that have occupied me since I began research in marine biology following graduation at Edinburgh in 1922. Initial work on the bivalve molluscs, Mya arenaria and Ostrea edulis, at Edinburgh and Plymouth respectively, was followed by appointment as Balfour Student in the University of Cambridge and leadership of the Great Barrier Reef Expedition of 1928–29. There I made acquaintance with corals, with the reefs they form and with their associated molluscan fauna, which has since been widely extended in other regions of the Indo-Pacific and also in the Gulf of Mexico and the Caribbean in the Atlantic. It is clearly impossible to review this wide subject-matter, this address representing a statement of opinion based largely on the results of personal research.

Studies of the growth stages of some species of Promicroceras (Currie, 1942 and 1943) have led to similar inquiries into the growth stages of other genera. The choice of genera studied has been determined mainly by the material available; but fortunately the material available has provided an opportunity for investigation of a compressed fairly involute form (Witchellia) and some depressed involute forms (Cadoceras and some Sphaeroceratids) for comparison with the evolute Promicroceras.

Most of the specimens used are from a collection of ammonites kept for study by Professor A. E. Trueman, to whom the writer is again indebted for material. Other specimens used are from the collection of the Hunterian Museum, Glasgow University. As usually happens in investigations of this kind, a number of the specimens cut had to be discarded owing to the structure being obliterated by calcification. As a result, the number of measurable sections available was smaller than one had hoped.

Stable isotopic ratios (mainly 18O/16O, but also D/H) have been measured for the three most important types of late-Hercynian granites, and their hosts, in the western area of the Central Iberian Massif (CIM), Spain. These granites are amphibole-bearing biotite granites, biotite granites and cordierite-bearing biotite granites. No intrusive relationships have been observed among them; the contact of each granite with the others is always gradational. Host-rocks are Precambrian/Cambrian metasediments, ranging from low-grade schists to migmatites (nebulites).

Whole-rock δ18OSMOW values are as follows: amphibole-bearing biotite granites 8·9 ± 0·58% (1σ, n = 17); biotite granites 9·0 ± 0·35% (1σ, n = 11); cordierite-bearing biotite granites 9·6 ± 0·24% (1σ, n = 21). δ18O values for nebulites, into which some of these granites were emplaced, are significantly higher, at 11·1 ± 0·58‰ (1σ, n = 13). The Precambrian to Cambrian shales gave an average value of δ18O = 11·9 ± l·23‰ (lδ, n = 5). Whole-rock oxygen isotope ratios indicate that the origin of the granites was in neither purely sedimentary/metasedimentary rocks nor pristine mantle melts. δ18O values close to 9·0‰ require a crustal protolith, having an important recycled component.

Oxygen isotope results are compatible with the cordierite-bearing granites being generated by assimilation of nebulite-like material by a biotite granite magma. However, 18O/16O of mineral separates obtained from the three different granites and the nebulite indicate that isotopic equilibrium, if ever reached, has not been preserved. The modified isotopic equilibrium is attributed to fluid activity, but mineral-pair δ-δ plots suggest that the granite system behaved as a closed system, and that the fluid was deuteric (magmatic) in origin. This implies that if assimilation did happen, it occurred at a temperature higher than the closure temperature of the different minerals to isotopic exchange. In a δ18O vs δD plot, hornblende and biotite separates from the granites plot within the igneous field. A simple mesocrustal anatectic origin for the peraluminous late Hercynian granites of the western area of the CIM is difficult to sustain on the basis of the stable isotope data, consistent with other field, petrographic and geochemical evidence. Cordierite in the cordierite-bearing granites is not “restitic” from a deep source area, but rather is xenocrystic from the high-grade metamorphic country rock (nebulites).

It should be possible to infer the thermal state of the source terrane for granitic bodies, provided we have independent means to establish the chemical nature of this terrane. The chemical nature of the granitic rocks, including their degree of hydration, implies the solidus temperature. The concentration of the heat-producing radioactive elements in the granite (K, U, and Th) probably provides an upper estimate of their concentration in the source rock, which is an important thermal parameter. The depth and ambient temperature of the country rock into which the granite magma intruded provide useful boundary conditions for the thermal regime at the crustal level of anatexis. These constraints in turn form the bases for estimating the subcrustal thermal flux as well as the effective thermal interface for enhanced heat flow from below that resulted in anatexis. These inferences, in combination with other field-based parameters such as uplift rates and permissible time lapses for the geological events, permit realistic thermal modelling for the formation of granitic batholiths. The procedure is applied to the Late Cretaceous Pioneer and Boulder batholiths in southwestern Montana, U.S.A. The modelling results suggest that mantle upwelling, not subduction or thrust loading, caused anatexis. The isotopic chemistry of the granitic rocks rules out direct mixing of mantle magma, and field relations rule out crustal thinning as causes for partial melting.

Faunas of disarticulated ossicles, particularly columnals, are a potentially important source of data for helping to elucidate the patterns of evolution and extinction shown by pelmatozoans in the late Ordovician. The columnal fauna of the Hirnantian High Mains Formation, Craighead Inlier, Strathclyde, includes the following morphotaxa: Cyclocyclicus (col.) foraminosus sp. nov.; Cyclocyclicus (col.) periogmos sp. nov.; Hypsinomocrinus (col.) lewisi gen. et sp. nov.; Tetragonotetragonalis (col.) girvanensis sp. nov.; and Pentagonopentagonalis (col.) sp. This is the first Hirnantian columnal fauna to be described from the North American province; it is distinctly different from Hirnantian columnal biota described from Wales and Kazakhstan.

A-type felsic magmatism associated with the Cambrian Southern Oklahoma Aulacogen began with eruption of voluminous rhyolite to form a thick volcanic carapace on top of an eroded layered mafic complex. This angular unconformity became a crustal magma trap and was the locus for emplacement of later subvolcanic plutons. Rising felsic magma batches ponding along this crustal magma trap crystallised first as fine-grained granite sheets and then subsequently as coarser-grained granite sheets. Aplite dykes, pegmatite dykes and porphyries are common within the younger coarser-grained granite sheets but rare to absent within the older fine-grained granite sheets. The older fine-grained granite sheets typically contain abundant granophyre.

The differences between fine-grained and coarse-grained granite sheets can largely be attributed to a progressive increase in the depth of the crustal magma trap as the aulacogen evolved. At low pressures (<200MPa) a small increase in the depth of emplacement results in a dramatic increase in the solubility of H2O in felsic magmas. This is a direct consequence of the shape of the H2O-saturated granite solidus. The effect of this slight increase in total pressure on the crystallisation of felsic magmas is to delay vapour saturation, increase the H2O content of the residual melt fractions and further depress the solidus temperature. Higher melt H2O contents, and an extended temperature range over which crystallisation can proceed, both favour crystallisation of coarser-grained granites. In addition, the potential for the development of late, H2O-rich, melt fractions is significantly enhanced. Upon reaching vapour saturation, these late melt fractions are likely to form porphyries, aplite dykes and pegmatite dykes.

For the Southern Oklahoma Aulacogen, the progressive increase in the depth of the crustal magma trap at the base of the volcanic pile appears to reflect thickening of the volcanic pile during rifting, but may also reflect emplacement of earlier granite sheets. Thus, the change in textural characteristics of granite sheets of the Wichita Granite Group may hold considerable promise as an avenue for further investigation in interpreting the history of this rifting event.

The structures and mineralogy of the Tertiary ultrabasic and basic intrusions are described. The ultrabasic rocks are thought to be remnants of a layered intrusion which once extended from Hirta to Boreray, and which probably formed by crystal accumulation. The eucrites may represent higher levels of this intrusion. A 350 feet-thick, fine-grained margin is described from the East Glen Bay Gabbro. The metamorphism of the ultrabasic and eucritic rocks, and the formation of the Glacan Mor Complex, probably occurred in a basic environment, before intrusion of the first acid rocks on St. Kilda. Five major-element and twenty-two trace-element analyses are presented.

Among the interesting specimens which have been yielded by the material of Calciferous Sandstone age (Culm), from Pettycur, near Burntisland, are a petiole of Dineuron and a very small species of Botryopteris. The former genus does not appear to have been previously discovered in Britain, and the present species is, as far as I am aware, only represented by a single example. The Botryopteris, in the form of fragments of petioles, is not infrequent, but its stems are of much more rare occurrence.

Perhaps the most interesting feature connected with the Old Red Sandstone formation in Shetland is the evidence of prolonged volcanic activity in those northern isles. The great development of contemporaneous and intrusive igneous rocks, which gives rise to some of the most striking scenery in Shetland, is all the more important when compared with the meagre records in the Lower Old Red Sandstone of Orkney and the Moray Firth basin. Not till we pass to the south of the Grampians do we find evidence of a far grander display of volcanic action during this period, in the sheets of lava and tuff in the Sidlaws and Ochils and in the great belt stretching from the Pentlands south-westwards into Ayrshire. The relations of the Shetland igneous rocks are admirably displayed in the various coast sections, especially in the mural cliffs of Northmavine and some of the Western Islands. From these records, though they have been subjected to much denudation, it is possible to construct a tolerably complete sketch of the volcanic history of this formation, as developed in that region.