Soils developed on basic igneous rocks, or their associated glacial drifts, are of fairly common occurrence in North-East Scotland and occupy a considerable area in Aberdeenshire. So far, only isolated studies with some specific object in view have been made of such soils, and a few descriptions with analyses have been published (Mitchell, 1936; Muir and Fraser, 1940; Whelan, 1939; Ogg, 1935). Interesting and important facts have been brought out in these investigations, but, apart from the work of Muir, no attempt has been made to study the distribution and field relations of the soils, and arable soils are mentioned only incidentally by Muir. In the present study an account is given of the classification and distribution of the various soil types occurring in the Kennethmont, Insch, Old Meldrum district of Aberdeenshire, an area which is highly farmed and which has long had a high reputation for its fertility and productivity. A soil map is given at the end of this study.

Volcanic eruptions and their deposits provide paleobiologists with an array of depositional environments in which to investigate the conditions in which exceptionally preserved flora and fauna are preserved. Studies of vegetation patterns before and after eruptions have shown that tropical vegetation makes a very rapid recovery at the vegetational level (proportion of devastated land covered). The recolonisation of the rare elements of a diversified flora, however, is slow, and so is the rebound of floristic richness, assembled over centuries from surrounding patches of vegetation and from in situ speciation.

Two major volcanic events that occurred in the past 15 years were studied in an attempt to understand the processes and complex patterns of plant deposition in volcanic landscapes. Both volcanoes gave rise to terrestrial, andesitic, explosive eruptions that gave little warning of their absolute magnitude or duration. In both eruptions, sediment-dammed lakes were formed in which a large quantity of plant material was trapped. In both instances, forests were killed and both standing and fallen trunks record the composition of the pre-eruption flora. The vegetation present in the vicinity of the volcanoes was, in the case of Mount St Helens (Washington, U.S.A.), dense coniferous forest living in a cool temperate climate and, in the case of El Chichón (Chiapas, Mexico), remnants of paratropical rainforest alternating with patches of agricultural land.

Litter layers are present under the tephra at both volcanic sites, yet the pattern of deposition and quality of the plant material differs dramatically between the two, in part because of differences in the types of eruptions and in part because of the nature of the plants available for burial. One of the most significant styles of burial, unexpected in the air-fall ash deposits, is the presence of more than one eruptive layer generated by eruptions only hours apart. These separate eruption layers have different lithological characteristics and the plant deposits buried in the different layers are different in taxonomic composition. Significantly, leaves in the upland volcanic-ash deposits are preserved thus far for 10 years, even in the tropical settings where root growth might be expected to have obliterated all signs of depositional stratigraphy. These impressions and compressions have a high likelihood of entering the fossil record and provide an excellent example of upland deposition and preservation.

Chondrenchelys problematica, from the Viséan (Holkerian) of Scotland, is the earliest holocephalan known from extensive cranial and postcranial material. Here, we provide a comprehensive new description of this taxon using three new specimens, in which we observe many morphological features for the first time. Much of the cranial morphology is closer to that of living chimaeroid holocephalans than was previously appreciated. For this reason, we provide original figures illustrating the chondrocranium of a hatchling Callorhinchus milii demonstrating these similarities. In Chondrenchelys, although the jaw articulation is positioned at the posterior margin of the orbit, the high-walled lamina orbitonasalis and densely-mineralised antorbital crest provide evidence for forward rotation of the jaw adductor musculature. Preserved foramina for the efferent superficial ophthalmic nerves show that the sensory organs on the rostrum were enervated in a manner similar to modern sharks, with the ophthalmic nerves not enclosed in an ethmoid canal, as in modern holocephalans. The conjunction of numerous distinctly holocephalan features with those that are otherwise general to Chondrichthyes demonstrates a decoupling of several of the structural conditions that characterise the distinctive morphological complex of the extant holocephalan skull. The anguiliform postcranium is more elongate than previously reconstructed, and it is now clear that the axial skeleton extended beyond the posterior extremity of the elongate dorsal fin. Morphological characters are reviewed with a view to further phylogenetic analyses. We recommend using the appearance of Chondrenchelys at 336.5 Ma as a hard minimum age for the last common ancestor of elasmobranchs and chimaeroids, because of its secure association with other holocephalans, and current uncertainties concerning elasmobranch stem lineage membership.

The skull anatomy of a new species of the phytosaur Machaeroprosopus is described for the first time on the basis of two specimens from the Upper Triassic Cooper Canyon Formation of Texas. Additional information is provided by a third specimen referred to Machaeroprosopus sp. A paranasal bone, an additional paired element of the narial region, is identified. Important new data are presented for the braincase, including the morphology of the epipterygoid and presphenoid, an anterior process of the prootic, an anteroventral process of the laterosphenoid, and a parasphenoid process. Machaeroprosopus lottorum n. sp. is characterised by four apomorphies: a supratemporal fenestra closed on the skull roof with bevelled anterior rim, a comparatively short squamosal, a flat and rugose narial rim, and medially extended palatines that come close to form an ossified secondary palate. With respect to the supratemporal fenestra, the supraoccipital–parietal complex and several features of the squamosal, Machaeroprosopus lottorum n. sp. bridges the morphological gap between species previously referred to the genera Pseudopalatus and Redondasaurus. A parsimony analysis of known species of Machaeroprosopus supports the hypothesis that the development of the rostral crest in Machaeroprosopus is a sexually dimorphic feature, and questions the validity of the genus Redondasaurus. Consequently, Redondasaurus is here considered a junior synonym of Machaeroprosopus.

This paper describes extensive new collections of ammonites made bed-by-bed across the Oxfordian/Kimmeridgian boundary sequence in the Flodigarry sections at Staffin Bay on the Isle of Skye. The ammonites belong to the Sub-Boreal family Aulacostephanidae and the Boreal family Cardioceratidae, enabling recognition of both the current standard Sub-Boreal and Boreal ammonite zonations. In consequence, it is possible to make a close correlation of these two zonal schemes through the interval studied in Skye. The research has provided new palaeontological data at levels of precision that justify the proposal of the section at Staffin as the site of a potential Global Boundary Stratotype Section and Point (GSSP) for the Oxfordian/Kimmeridgian boundary.

The traditional Oxfordian/Kimmeridgian boundary placed at the Pseudocordata/Baylei zonal boundary of the Sub-Boreal zonal scheme corresponds precisely to the Rosenkrantzi/Bauhini zonal boundary of the Boreal zonal scheme. This level is characterised by the appearance of the first Pictonia (Pictonia flodigarriensis sp. nov.) together with first Prorasenia, replacing an older assemblage of Ringsteadia–Microbiplices (Sub-Boreal). It is also characterised by the first occurrence of small-sized Amoeboceras (Plasmatites) spp., as well as large Amoeboceras schulginae Mesezhnikov (Boreal). An alternative level that may be considered as a potential GSSP is the boundary between the Bauhini Zone and the Kitchini Zone of the Boreal zonal scheme, characterised by first occurrence of Amoeboceras (Amoebites) of the A. bayi group. This level corresponds to the Planula/Galar subzonal boundary of the Sub-Mediterranean zonal scheme, and lies close to the currently accepted Oxfordian/Kimmeridgian boundary in the Sub-Mediterranean Province.

This piece of work was undertaken as the result of certain observations made during class-work on irregular nutrition. This particular species of Cuscuta was being successfully grown at the time in Glasgow Botanic Gardens, and my sincerest thanks are due to Mr Banks, the Curator of the Gardens, who has very kindly allowed me to have abundant material at all times, and has also provided me with various host-plants upon which to grow the parasite. He has also allowed me to make observations on the plants growing in the Gardens, and to take photographs whenever I wished.

Numerous permineralised, complex medullosan pollen organs are described from Middle and Upper Pennsylvanian sediments of North America. Together with a reinvestigation of type specimens for the previously described species, these provide the basis for fully characterising internal structure and external morphology, and for recognising structural homologies among all medullosan synangia. All medullosan pollen organs, simple and complex, can be interpreted as consisting of sporangial tubes that are embedded in parenchymatous and sclerenchymatous ground tissue, and that have vascular bundles within the parenchymatous tissue. The sporangial tubes are arranged in a single series, usually a ring, with parenchymatous ground tissues and vascular bundles to the outside of the ring and sclerenchymatous ground tissue to the inside of the ring. In the larger, complex forms the ring is plicately folded and there may be a centrally-placed hollow in the distal surface. Differences in morphology, in the folding pattern of the rings, in the structure (or absence) of a distal hollow, and in architecture of the major vascular system are employed to delimit genera. Size and shape of the organ, histological features, numbers of sporangia, and presence or absence of lacunae are used to delineate species. Currently recognised genera are Dolerotheca Halle, Sullitheca Stidd et al., Stewartiotheca Eggert and Rothwell, and Bernaultia gen. nov.

The life history of Petrobius brevistylis Carpenter is described from material reared in the laboratory and captured in the field (south Devonshire). A method of identifying the first eight instars is discussed and their diagnostic morphological characters described. Fecundity and time of oviposition are considered at some length. The effects of climate on various phases of the life history are considered as well as the faunas found associated with P. brevistylis. A brief description of the life history of P. maritimus (Leach) is included.

In following out the life-histories of some of the water-beetles I have been struck by the remarkable differences in habits and in structure between the members of a family, for instance, between Hydrophilus and Hydrobius, two fairly closely related genera of the Hydrophilidæ. The description of the life-history of Hydrophilus as given by Miger, Lyonnet, and others will, only to a small extent, apply to Hydrobius, although the suggestions which I am able to make with regard to certain facts in the life-history of the latter may throw light upon somewhat similar facts in the life-history of the former.

Representatives of the Hemiptera: Sternorrhyncha, Fulgoromorpha, Cicadomorpha and Heteroptera from the Late Eocene of the Isle of Wight, UK, are analysed and discussed. Psylloidea were reviewed and a key to the described taxa is given. Aphidoidea were studied, previously described taxa revised and new taxa described. New taxa of Aphidoidea are Hormaphididae: Hormaphis? longistigma Wegierek sp. nov.; Eriosomatidae: Eriosoma gratshevi Wegierek sp. nov. and Colopha? incognita Wegierek sp. nov.; Drepanosiphidae: Panfossilis anglicus Wegierek gen. et sp. nov. and Betulaphis kozlovi Wegierek sp. nov. Previously described Fulgoromorpha were revised and new taxa are described. The homonym Hastites Cockerell, 1922 (Cixiidae) preoccupied by Hastites Mayer-Eymar, 1883 is replaced by Catulliastites Szwedo nom. nov. for Catulliastites muiri (Cockerell) comb. nov. New taxa described are Cixiidae: Klugga gnawa Szwedo gen. et sp. nov., Klugga regoa Szwedo sp. nov., Liwakka gelloa Szwedo gen et sp. nov., Delwa morikwa Szwedo gen. et sp. nov., Kommanosyne wrikkua Szwedo gen. et sp. nov., Kernastiridius nephlajeus Szwedo gen. et sp. nov., Margaxius angosus Szwedo gen. et sp. nov., Dweivera reikea Szwedo gen. et sp. nov., Samaliverus bikkanus Szwedo gen. et sp. nov., Komsitija tuberculata Szwedo gen. et sp. nov., Langsmaniko marous Szwedo gen. et sp. nov., Komnixta jarzembowskii Szwedo gen. et sp. nov. and Worodbera nimakka gen. et sp. nov.; Tropiduchidae: Reteotissus hooleyi Szwedo gen. et sp. nov., Phatanako gen. nov. for Phatanako wilmattae (Cockerell) comb. nov., Senogaetulia kwalea Szwedo gen. et sp. nov., Dakrutulia mikhailkozlovi Szwedo gen. et sp. nov., Keriophettus atibenus Szwedo gen. et sp. nov. and Sognotela emeljanovi Szwedo gen. et sp. nov.; Issidae: Krundia korba Szwedo gen. et sp. nov., Breukoscelis vadimgratshevi Szwedo gen. et sp. nov., Breukoscelis phrikkosus Szwedo sp. nov. and Uphodato garwoterus Szwedo gen. et sp. nov.; Nogodinidae: Ambitaktoinae Szwedo subfam. nov., Ambitaktoa stoumma Szwedo gen. et sp. nov., Phariberea gurdonika Szwedo gen. et sp. nov., Wixskimoa torxsea Szwedo gen. et sp. nov., and Nadrimini trib. nov. with Niadrima yulei Szwedo gen. et sp. nov.; Lophopidae: Ankomwarius brodiei Szwedo gen. et sp. nov.; Ricaniidae: Ankwlanno bluga Szwedo gen. et sp. nov. Previously described Cicadomorpha were revised and new taxa are described: Cicadidae: Kintusamo boulardi Szwedo gen. et sp. nov; Aphrophoridae: Blenniphora Szwedo gen. nov. for Blenniphora woodwardi (Cockerell) comb. nov., Blenniphora skaka Szwedo sp. nov. and Blenniphora bikkanoa Szwedo sp. nov.; Luisphantyelus briwus Szwedo gen. et sp. nov., Natajephora lijanka Szwedo gen. et sp. nov.; Cercopidae: Berro enissuextaensis Szwedo gen. et sp. nov.; Cicadellidae: Mileewinae: Teniwitta andrewrossi Szwedo gen. et sp. nov. Formerly described true bugs (Heteroptera) are revised and several new taxa are described – Nepomorpha: Corixidae: Diacorixites szwedoi Popov gen. et sp. nov.; Cimicomorpha: Tingidae: Parasinalda wappleri Popov sp. nov., Viktorgolubia Popov gen. nov. for Viktorgolubia seposita (Cockerell) comb. nov.; Miridae: Gurnardinia herczeki Popov gen. et sp. nov.; Pentatomomorpha: Lygaeidae: Gurnardobayini Popov trib. nov., Gurnardobaya rossi Popov gen. et sp. nov.; Cydnidae: Eocenocydnus lisi Popov gen. et sp. nov.; Pentatomidae: Podopinites coloratus Popov gen. et sp. nov. and Podopinites acourti (Cockerell) comb. nov. An overview of the Late Eocene fauna of the Hemiptera is presented. Ecological and biogeographical patterns of the Hemiptera from the Isle of Wight deposits are discussed.

The extensive series of specimens of members of the Hyolithidæ which Mrs Elizabeth Gray has collected from the Ordovician and Silurian beds of the Girvan district, and submitted to me for investigation, forms the basis of the following memoir.

Through the kindness of Dr John Horne and Professor J. W. Gregory, special facilities have been afforded me of examining the other Scotch examples in the Geological Survey Collection, Edinburgh, and the Museum of Glasgow University. My thanks are also due to Dr F. L. Kitchin for the opportunity of studying the specimens in the Jermyn Street Museum.

The Recent Saefell tuff-ring on Heimaey, Iceland was formed by surtseyan activity in shallow seawater. The tuff-ring has a basal diameter of about 3 km, a maximum rim height of 188 m above sea-level and a crater diameter of 1300 m. Three tuff-units are recognised, separated by unconformities on and inside the crater rim due to syndepositional slumping. The crater contains a nested rim which was constructed above slumped crater tuffs. Directional data indicate strongly directed blasts to the SW at a late stage in the activity.

Throughout the volcanic activity, base-surges formed antidunes, U-shaped channels, vesiculated tuffs, small ripples and plastering structures. One antidune reflects a decrease in surge flow power during deposition and subsequent slumping due to base-surge drag and instabilities developed during growth. On the basis of field characteristics, the structures are divided into those deposited by hot, dry, fast-moving surges and those by cooler, wet, slow-moving surges. Base-surges are compared with turbidity currents and deposition of distinct structures by the head, body and tail regions is interpreted.

The changes in the vascular pattern of the pregnant rat uterus at placental sites and the intervening areas, have been studied radiologically and by injection techniques during the period of pregnancy. A description is given of the development and final pattern of the maternal placental blood channels. From the 15th day onwards wide variations are found in the vascular filling of placentæ after arterial injection. Possible mechanisms for the control of blood flow to placental sites are discussed.

A survey is given of the functional morphology of extant Chelicerata with special reference to segmentation of the body, segmentation and articulation of the legs, coxal glands, mouthparts and ingestion, respiratory organs, sperm transfer, and development. This is followed by a discussion of primitive types, evolution and diversity, the transition from aquatic to terrestrial life, and the affinities of extant chelicerate groups.

Heterodontosaurids are poorly understood early ornithischian dinosaurs with extensive geographic and stratigraphic ranges. The group is best known from the Lower Jurassic upper ‘Stormberg Group’ (upper Elliot and Clarens formations) of southern Africa, previously represented by at least three distinct species and ten described specimens. This paper describes four additional heterodontosaurid specimens from southern Africa. A partial skull of a large individual of Heterodontosaurus tucki (NM QR 1788) is approximately 70 longer than that of the type specimen of Heterodontosaurus, and provides new information on allometric changes in mandibular morphology during growth in this taxon. It is the largest known heterodontosaurid cranial specimen, representing an individual approximately 1·75 metres in length, and perhaps 10 kg in body mass. NHMUK R14161 is a partial skull that appears to differ from all other heterodontosaurids on the basis of the proportions of the dentaries, and may represent an unnamed new taxon. Two additional partial skulls (NHMUK RU C68, NHMUK RU69) are referred to cf. Lycorhinus. At least four, and possibly five or more, heterodontosaurid species are present in the upper ‘Stormberg’. This high diversity may have been achieved by dietary niche partitioning, and suggests an adaptive radiation of small-bodied ornithischians following the end Triassic extinctions.

The author recalls the various opinions which have been expressed as to the relationships of Blanckenhorn's genus Dictyoconus to other foraminiferal types. He shows how Dictyoconus has been affiliated to the genera Lituola, Lituonella, and Coskinolina by such authorities as Messrs Schlumberger, Douvillé, and Schubert in the past; but has since been dissociated from them by Professor Cushman in his recent monograph on the Foraminifera. The author then discusses the grounds for this dissociation, which seem to him to be inadequate; and he describes his discovery, in certain Lower Eocene beds of Northern Baluchistan, India, of numerous specimens of Didyoconus, Coskinolina, and Lituonella, mixed indiscriminately together within the same narrow limestone bands, and deceptively similar in external appearance. He describes the differences between these genera—differences which are confined to the peripheral portion of the test—and shows how sections of the three Indian forms reveal the closest agreement in their internal characters as a whole; their generic characters alone affording the means of distinguishing between them. He therefore regards these Indian forms as affording clear evidence of the close affiliation of these three genera. These Indian forms, which are the first representatives of their respective genera to be found so far east, are very similar to such western forms as Dictyoconus egyptiensis (Chapman), Coskinolina liburnica Stache, and Lituonella roberti Schlumberger and Douvillé; but they have individual peculiarities of their own, and so are described by the author as three new species.

The Stephanian Konservat-Lagerstätte of Hamilton, Kansas, deposited in a marine-estuarine environment preserves a mixture of terrestrial, fresh-water, and marine fossil organisms. The marine component is the most diverse taxonomically, whereas one ostracod species, commonly interpreted as a fresh-water form, together with vascular plant debris dominates volumetrically. Well-preserved terrestrial and aquatic vertebrates and arthropods were embedded in rapidly deposited calcareous mud conducive to microbial early-diagenesis of vertebrate soft tissues in a tidal estuarine setting. Many vertebrate fossils show no evidence of preburial decay or disarticulation. Dark-coloured body silhouettes (‘skin preservation’) are composed of calcitic bacteria, calcite crystals and organic material, and have been interpreted to reflect preservation under saline conditions. The aquatic vertebrates had a broader tolerance of salinity than today. The fishes were perhaps migratory (anadromous or catadromous), and some used the estuarine environment for spawning. The tetrapods (dissorophid amphibians) retained their tolerance to salinity from their marine ancestors and were able to spawn in near-shore environments. The terrestrial biota was dominated by the conifer Walchia and was subjected to forest fires, as evidenced by preserved charcoal fragments.

Critical collecting, measurement of sections and taxonomic reassessment through the Climacograptus wilsoni Zone (basal Lower Hartfell Formation) of the southern Scottish graptolite zonal sequence suggests that, although only locally developed, it is an easily recognisable and useful biostratigraphic interval. The North Cliff of Hartfell Spa is defined as type section for both the base of the Lower Hartfell Formation and that of the C. wilsoni Zone. The zonal assemblage is figured and described, with particular emphasis being placed on the distinctive species C. wilsoni which has not been redescribed since the beginning of this century.

Garnet-bearing xenoliths from Letseng-la-Terae display a range of textures from coarse to granuloblastic. Equilibration temperatures and pressures of primary phases are in the ranges 950-1400°C and 27-50 kb, respectively. Deformed lherzolites equilibrated throughout this temperature range but coarse xenoliths are restricted to low temperature equilibration.

All garnets display coronas developed during the reaction:

In some rocks, reaction has completely eliminated garnet.

In rocks where garnet is disrupted, the corona minerals are strung out in the fluidal texture indicating that reaction occurred before deformation. Rocks transitional to, and of granuloblastic texture, contain garnet and aluminous spinel; in addition ‘pools’ of minerals originating by dynamic separation of corona fragments are observed.

Chemical comparison between the corona minerals and minerals in a garnet-spinel rock and two spinel granuloblastites, suggests that these spinel-bearing rocks may be derived from normal garnet peridotite by a complex sequence of reaction, followed by deformation, annealing and chemical homogenisation. The conclusion that reaction and deformation took place at high levels in the upper mantle is contrary to some earlier hypotheses of shearing within the low velocity zone in response to continental plate movement, but is consistent with mantle diapir models.

The zoning found in ore deposits is dominantly of two distinctive types: that in syngenetic sedimentary deposits, like the Kupferschiefer, and that in common hydrothermal deposits of either epigenetic or syngenetic characteristics. Here, epigenetic hydrothermal deposits include those commonly classified as vein, porphyry copper, contact metasomatic, and Mississippi Valley deposits; the syngenetic hydrothermal deposits are conformable, massive ores such as at Rammelsberg. The two zoning sequences, beginning nearest the source of the metals, are: in hydrothermal deposits, Fe—Ni—Sn—Cu—Zn—Pb—Ag—Au—Sb—Hg, and in sedimentary deposits, Cu—Ag—Pb—Zn.

A zoning sequence represents the natural order of increasing solubilities of the metallic sulphides and other minerals in ore-forming solutions. Comparison of zoning sequences with relative solubilities in proposed ore solutions provides a rigorous test of the efficacy of such solutions. When corrected for relative metal concentrations (mass-action effect), then both theoretically predicted, and experimental relative solubilities of sulphide complexes match precisely the order of hydrothermal zoning. The order in sedimentary zoning is identical to the mass-action-corrected calculation of the sequence in which sulphides must precipitate from solutions containing metallic ions or weak chloride or hydroxyl complexes. The consanguinity of these correlations imply (1) that hydrothermal zoning is the product of deposition from sulphide complexes, and (2) that chloride complexes may be the metal-transporting agent in sedimentary deposits.