This study describes bioerosion traces ascribed to either predation or endo- and epibiont activity in twenty assemblages from the Mediterranean region and Paratethys, spanning in age from Eocene to Recent. Statistical analysis of the distribution of bioerosion traces among genera and assemblages revealed that there is higher drilling predation intensity on smaller species. Larger species seem to be primarily affected by non-drilling predators. Greatest variety in types of bioerosion could be related to species’ ecology and body size. Both major categories of bioerosion (etchings and traces of predatory activity) vary considerably among samples. Different genera show significant differences in the frequency of different bioerosion types. Shell size seems a major factor contributing to these differences.

Among the numerous fragments of plants found inside the fossil hollow tree stumps of Lepidophloios wünschianus Carr. from the Calciferous Sandstone Series in the island of Arran (Walton, 1935, p. 313) are two small portions of a strobilus. These fragments are embedded in the calcite matrix, and as they are separated from one another by a distance of only a few millimetres it is possible that they are parts of one strobilus. They have suffered considerable maceration and distortion before petrification occurred. A series of over 54 peel sections transverse to the axes of the two fragments and a series of 80 longitudinal sections through one of them were prepared. The longitudinal sections were made from 4 mm. of the block of material. Each section therefore used on an average 0·05 mm. of the block.

This paper completes the description of intact and three-dimensional Ctenopyge species from the upper Cambrian Peltura minor Zone in Västergötland, central Sweden. All these species are present together, on the same bedding planes. The most abundant species, Ctenopyge (Eoctenopyge) angusta Westergård, 1922 has previously been described, and an almost complete ontogeny worked out. C. (Ctenopyge) gracilis Henningsmoen, 1957 is a small trilobite with nine thoracic segments and very long, thin curving and subparallel thoracic spines; the genal spines partially encircle the body. Two axial spines at the rear are of considerable length. When reconstructed in side view, the posterior thoracic spines rise upwards as an inclined fan, but when relaxed the tips of all the thoracic and axial spines come to lie in the same plane as the horizontal genal spines. An almost complete ontogeny is described for this species, and individuals show an evident spinosity from an early stage, but the body size at which thoracic segments are liberated is highly variable. C. (Ctenopyge) ahlbergi n. sp. is a larger, robust and broad species distinguished by long, stout genal spines, ten thoracic segments, and a very spiny body with the first three to four spines expanded into lateral flanges. A degree 6 meraspis shows these flanges already developing. C. (Ctenopyge) rushtoni n. sp has likewise ten thoracic segments, and has stout, broad-based and tapering spines. Incomplete meraspides 6 and 7 are known for this species. In both C. (Ctenopyge) ahlbergi and C. (Ctenopyge) rushtoni there are also two axial spines at the rear, and the extended body would have had a similar rising tail fan to that of C. (Ctenopyge) gracilis. C. (Mesoctenopyge) tumida is also present as a single large adult and several smaller holaspides. In this species the first thoracic segment is confirmed as bearing a pair of long curving spines, somewhat smaller than the encircling genal spines. The remaining thoracic spines are straight and sharp, and evidently longer in young holaspides. There is a single long axial spine on the last segment. No adult pygidium has been found.

Some comments on the diversity of the fauna as a whole and the range of functional types are appended.

Specimens of trematopid amphibians from the Asturian (Upper Carboniferous) of Nýřany, Czech Republic, are redescribed as two taxa, namely Mordex calliprepes Steen and Mattauschia (gen. nov) laticeps Fritsch. Mordex calliprepes is represented by a single post-metamorphic specimen and has the diagnostic trematopid characters of the nasal region. Mattauschia laticeps is represented by one adult partial skull and mandible plus some fragments and two small post-metamorphic specimens including the species name-bearer. It has the trematopid-type modified lacrimal and a large but oval naris and appears to be the most primitive trematopid yet described. The stratigraphically sequential large trematopids Mattauschia, Fedexia, Ecolsonia and Acheloma show progressive acquisition of the derived features that characterise the terminal form Acheloma.

Mordex has a combination of primitive and derived characters and its position within the family is less clear. The many ‘branchiosaurs' in the Nýřany assemblage include specimens that could be larvae of both Mordex and Mattauschia but certain attribution is not possible and they are assigned to Olsoniformes incertae sedis. Mordex and Mattauschia appear to be terrestrial exotic elements in the Nýřany tetrapod assemblage, but with possible larvae in the lake assemblage. Representatives of at least four Palaeozoic dissorophoid families were present in late Middle Pennsylvanian/Asturian strata implying diversification of the Dissorophoidea prior to this time.

The lower Carboniferous–late Permian dyke swarms of the Scottish Highlands and Islands comprise a mild-strongly alkaline basic series of dolerites, camptonites and monchiquites. Differentiation within the suite was largely controlled by olivine + clinopyroxene fractionation. Major and trace element data indicate that dolerites and camptonites chemically overlap, their mineralogical contrasts resulting from differential loss of an H2O, CO2-rich fluid phase during ascent. By contrast most monchiquites have high Mg-values and are relatively primitive compositions, some being near-primary magmas which have risen rapidly from mantle levels with little chemical modification.

HREE-buffered incompatible element profiles imply a garnet–lherzolite source, which must underlie the lithospheric mantle region represented by spinel lherzolite xenoliths found in some monchiquites. C. 0·5–2·0% partial melting can account for the gross incompatible element variation in the suite, but relative fluctuations in K, Ba, Rb, Sr, P and Zr imply chemical heterogeneity controlled either by refractory mantle accessory phases or by modification of magmas during ascent through variably metasomatised lithospheric mantle.

I have to apologise for placing this communication before you in a somewhat incomplete form. My work has been much interrupted in the past, and it will again shortly be stopped for a considerable time. I have therefore decided to place before you the results so far as they are worked out.

Four kinds of robust elements have been recognised in Amorphognathus quinquiradiatus Moskalenko, 1977 (in Kanygin et al. 1977) from the early Late Ordovician of Siberia, indicating that at least 17 elements were present in the apparatus, one of them similar to the P1 element of the Early Silurian Distomodus. The new generic name Moskalenkodus is proposed for these conodonts with a pterospathodontid-like S series element morphology. This implies that the related Distomodus, Pterospathodus and Gamachignathus lineages had a long cryptic evolutionary history, probably ranging back to the early Ordovician, when they split from the lineage of Icriodella, having a duplicated M location in common. The balognathid Promissum, with a 19-element apparatus, may have shared ancestry with Icriodella in Ordovician high latitudes, with Sagittodontina, Lenodus, Trapezognathus and Phragmodus as possible connecting links. The pattern of the unbalanced contribution of Baltoniodus element types to samples suggests that duplication of M and P2 series elements may have been an early event in the evolution of balognathids. The proposed scenario implies a profound transformation of the mouth region in the evolution of conodonts. The probable original state was a chaetognath-like arrangement of coniform elements; all paired and of relatively uniform morphology. This was modified at the origin of protopanderodontids by the introduction of a medial S0 element, which resulted in the separation of the exposed unit of M and S series elements from the P series elements hidden in the throat. A rotation of the S series elements to an almost horizontal position in early prioniodontids may have promoted duplication of the M element pair. In Gamachignathus, Icriodella and Pterospathodus lineages, these elements are differentiated morphologically. Subsequent anteriorward bending of the P element series caused duplication of the balognathid P2 element pair, but they remained undifferentiated, even in the otherwise elaborate Promissum. The whole clade of conodonts with supernumerary element pairs in the apparatus has its roots in high latitudes of the Ordovician.

The hind limbs of birds have long been considered a key feature in the conquest of different environments. However, the high level of morphological diversity encountered complicates the foundation of a good theoretical correlation between morphology, locomotor habits and substrate preference and this, in turn, complicates palaeobiological interpretations. Phorusrhacids (Aves, Cariamiformes) are a good example, since they have been unequivocally categorised as terrestrial birds due to their reduced forelimbs; and as apex predators with the ability to pursue prey based only on their hind limb morphology. Multivariate techniques (PCA and discriminant analysis), based on traditional metrics and geomorphometrics of the hind limb and pelvis, were applied in order to explore terrestriality and cursoriality in phorusrhacids. Although several groups of birds could be identified, when looking solely at hind limb metrics, some phorusrhacids appear to be associated with walking birds, while others are associated with cursorial birds. However, the pelvis separates cursorial birds and phorusrhacids from walking and wading birds. This scenario is complicated further by a lack of clear definition of the different locomotor modes and substrate preferences in extant birds, and this makes it difficult to confirm phorusrhacid cursoriality based solely on morphometrics. However, some qualitative features of the pelvis and foot make the picture a little clearer. To study limb adaptations in fossil birds, a more holistic study, with an emphasis on qualitative features of the whole posterior locomotor module, is necessary, since morphometrics leaves some issues unresolved. A comparison with the wings is also needed, in order to make a more complete analysis of locomotor behaviour.

Before continuing the description of the alimentary tract, there are two general questions which must first be discussed very shortly. So far we have only dealt with the first two parts, the buccal cavity and the pharynx, and the latter name has such a well-defined significance that it is easy to state the boundaries of that part of the canal to which it should be applied, and therefore to fix the limits of the part in front. Unfortunately there seems to be no sort of unanimity with regard to the exact application of the names of the parts which follow, so that it is not easy to be sure to what parts the names should properly be applied, and it is extremely difficult to make comparisons between different forms without repeating a large part of the work already done by other observers. To take a concrete case: the part to which the name “œsophagus” has been applied has been limited, by different workers, by the extent of the stratified epithelium, by the extent of the striated muscle, by the absence of a serosa, by the absence of glands, and even by the relative diameter of the tube. Needless to say, these various boundaries do not coincide (in many cases some of them do not exist), and hence the difficulty of unravelling the descriptions in the literature of the subject is very great. So in what follows the names used will be defined, and I hope the nomenclature suggested will be such as to be acceptable and of scientific utility throughout the Chordata.

The four stem-group neopterygians from Foulden are redescribed: Carboveles ovensi White, Aetheretmon valentiacum White, Strepheoschema fouldenensis White and Fouldenia ottadinica White. Carboveles is shown to be a junior synonym of Phanerosteon Traquair, Fouldenia ottadinica White is synonymised with Styracopterus fulcratus (Traquair), Strepheoschema rhodesi Moy-Thomas with S. fouldenensis White and Aetheretmon whitei Moy-Thomas with A. valentiacum White. The family Strepheoschemidae is erected to comprise Strepheoschema and Aetheretmon, characterised by paired ventral ridge scales in front of the pelvic fins. Cosmoptychius striatus (Agassiz), recorded here from Foulden for the first time, is widespread in the geologically younger Oil Shale Group. The Foulden actinopterygian fauna is identical to that of the Cementstone Group at Coomsdon Burn, Northumberland, although with two additional taxa. Styracopterus fulcratus occurs also at a further two Cementstone Group localities in Scotland.

The current underlying assumption in most geochemical studies of granitic rocks is that granitic magmas reflect their source regions. However, the mechanisms by which source rocks control the intensive and compositional parameters of the magmas remain poorly known. Recent experimental data are used to evaluate the ‘source rock model’ and to discuss controls of (1) redox states and (2) the Sr isotopic compositions of granitic magmas.

Experimental studies have been performed in parallel on biotite-muscovite and tourmaline-muscovite leucogranites from the High Himalayas. Results under reducing conditions ( = FMQ – 0·5) at 4 kbar and variable suggest that the tourmaline-muscovite granite evolved under progressively more oxidising conditions during crystallisation, up to values more than four log units above the FMQ buffer. Leucogranite magmas thus provide an example of the control of redox conditions by post-segregation rather than by partial melting processes.

Other experiments designed to test the mechanisms of isotopic equilibration of Sr during partial melting of a model crustal assemblage show that kinetic factors can dominate the isotopic signature in the case of source rocks not previously homogenised during an earlier metamorphic event. The possibility is therefore raised that partial melts may not necessarily reflect the Sr isotopic composition of their sources, weakening in a fundamental way the source rock model.

The Kenogamissi complex represents a large exposure of folded Late Archaean crystalline crust exposed within the Abitibi Subprovince, Ontario, Canada. It is composed of an heterogeneous amphibolite-grade orthogneiss unit, and several generations of batholiths and plutons of tonalite, granodiorite and granite composition. Together, the various units represent granitic magmatism during the period from 2740 Ma to 2660 Ma. Structural mapping and petrographic studies were focused on the orthogneiss unit (2723 Ma), on the newly defined Roblin tonalitegranodiorite batholith (ca. 2713 Ma) and on the highly strained metavolcanic rocks within the deformation aureole that surrounds the Kenogamissi complex. Structural analysis indicates that the Kenogamissi complex was emplaced into the greenstones as a dome that caused severe flattening and recumbent F2 refolding of earlier F1 folds in the deformation aureole. Doming is interpreted to be caused by the emplacement and inflation of tonalite-granodiorite batholiths, such as the Roblin Batholith, into the actively folding Swayze greenstone belt. Continued regional folding resulted in F3 refolding of F1 and F2 in the deformation aureole. Continued regional folding also deformed and folded the Kenogamissi complex and resulted in further uplift and emplacement of the complex into the greenstone belt. The early-formed magmatic foliation and compositional layering in the Roblin Batholith were folded by F3 while the batholith was still a crystal mush, and an F3 axial-surface magmatic foliation was locally formed. Folding of the partially molten Roblin Batholith also resulted in the remobilisation of fractionated liquids into shear zones which formed on the limbs of the F3 magmatic folds. Similar structures are present in the orthogneiss unit and are interpreted to represent remobilisation of melts which intruded the orthogneiss at the time of emplacement of the Roblin Batholith. The formation of the dykes on sheared fold limbs may be attributed to increased dilatancy during localised shearing of the crystal mush. Deformation-assisted remobilisation and extraction of fractionated liquids, and the possible transport of the fractionated liquids to higher levels in the crystallising Roblin Batholith, may have played a role in its magmatic differentiation.

The specimens which form the subject of this paper were collected on voyages to and from Australia on board the s.s. Orsova and Otway of the Orient Line. Sea-water was being constantly pumped on each ship, by a rotary pump, from an inlet about 18 feet below the water-line to a large tank on the boat deck, and I was allowed to run off, through a plankton net, as much of the water as I desired in order to collect the organisms contained therein. For this privilege, of which I availed myself to a liberal extent, I beg to thank Captain J. F. Healey and Captain F. S. Symons. The small organisms suffered comparatively little by their passage through the pump and pipes, and were, for the most part, in a living and active condition when examined.

Haller (1888), one of the first to publish an account of the alimentary tract in the Gastropoda, was followed by Amaudrut (1898) who produced a detailed comparative account of “La partie anteriéure du tube digestif” in a number of gastropods. Later workers have either studied the complete alimentary system in one or two gastropods (Herrick 1906; Dakin 1912) or have been concerned with the functional morphology of particular organs, such as the oesophagus, stomach, (Graham 1941; 1949), and proboscis (Alpers 1931; Carriker 1943). Much of this scattered work has been collected by Fretter and Graham (1962). Effectively nothing is known about the functional morphology of the alimentary tract in many groups, including the neogastropod families Turridae, Terebridae, and Volutidae. This account of the proboscis and oesophagus forms part of a general study of the functional morphology of the Turridae.

1. The experiments to which I shall have to refer in this paper were all made above ten years ago. A brief report of the general results, so far as they were then obtained, was made to the British Association in 1852, at whose expense the instrumental apparatus had been provided. The causes of the delay which has occurred in the publication of the numerical results will be presently explained.

The material for this work was obtained from the stock of Axolotls which breed in the Zoology Department of Glasgow University. The objection to using captive specimens for cytological work is overridden by the fact that the Axolotl, unlike some other urodeles, breeds readily in captivity, so that the germ-cell cycle can be taken as normal.

The reasons for wishing to add yet another account of urodele spermatogenesis to the considerable number already existing are twofold. First, widely different interpretations of a similar process in different species have been put forward, and one of the most recent accounts (Stieve, 1920, on Proteus) is entirely at variance with the usual course of spermatogenesis in urodeles. Second, there has been great discrepancy in the number of chromosomes assigned to this species.

Combined field and geophysical data show that plutons from the Bega Batholith are elongate, meridional, wedge-shaped bodies which intruded during a period of regional east–west extension in the Palaeozoic eastern Lachlan orogen, eastern Australia. Plutons within the core of the batholith have intruded coeval, syn-rift sediments and co-magmatic volcanics. The batholith is bound by high-temperature, dip-slip faults, and contains several major NE-trending transtensional faults which were active during batholith construction. In the central part of the batholith, the Kameruka pluton is an asymmetric, eastward-thickening, wedge-shaped body with the base exposed as the western contact, which is characterised by abundant, shallow-dipping schlieren migmatites which contain recumbent folds and extensional shear bands. A shallow (<30°), east-dipping, primary magmatic layering in the Kameruka pluton steepens progressively westward, where it becomes conformable to the east-dipping basal migmatites. The systematic steepening of the layering is comparable to sedimentary units formed during floor depression in syn-rift settings. The present authors suggest that the wedge-shaped plutons of the Bega Batholith are the deeper, plutonic expression of a hot, active rift. The batholith was fed and sustained by injection of magma through sub-vertical dykes. Displacement along syn-magmatic, NE-trending faults suggests up to 25 km of arc-perpendicular extension during batholith construction. The inferred tectonic setting for batholith emplacement is a continental back-arc, where modern half-extension rates of 20–40 mm yr−1 are not unusual, and are sufficient to emplace the entire batholith in ∼1 Ma. This structural model provides a mechanism for the emplacement of some wedge-shaped plutons and is one solution to the ‘room problem’ of batholith emplace

The collection of Actiniaria and Zoantharia made by the Scottish National Antarctic Expedition contains nineteen species, one of which, Porponia antarctica Carlgren, I described as a new species in 1914. In all there were six species from the Antarctic, three from the Falkland Islands, six from the west coast of Cape Province, three from the Cape Verde Islands, and one, not specifically determined, from Gough Island. The new species here described are Epiactis vincentina, Epiactis brucei, Sicyonis antarctica, and Palythoa vincentina. I have not thought it necessary to compile a complete list of the literature and synonyms of the species, since in the papers cited full information is given.

Lithostratigraphical studies coupled with the development of new dating methods has led to significant progress in understanding the Late Pleistocene terrestrial record in Scotland. Systematic analysis and re-evaluation of key localities have provided new insights into the complexity of the event stratigraphy in some regions and the timing of Late Pleistocene environmental changes, but few additional critical sites have been described in the past 25 years. The terrestrial stratigraphic record remains important for understanding the timing, sequence and patterns of glaciation and deglaciation during the last glacial/interglacial cycle. Former interpretations of ice-free areas in peripheral areas during the Last Glacial Maximum (LGM) are inconsistent with current stratigraphic and dating evidence. Significant challenges remain to determine events and patterns of glaciation during the Early and Middle Devensian, particularly in the context of offshore evidence and ice sheet modelling that indicate significant build-up of ice throughout much of the period. The terrestrial evidence broadly supports recent reconstructions of a highly dynamic and climate-sensitive British–Irish Ice Sheet (BIIS), which apparently reached its greatest thickness in Scotland between 30 and 27ka, before the global LGM. A thick (relative to topography) integrated ice sheet reaching the shelf edge with a simple ice-divide structure was replaced after the LGM by a much thinner one comprising multiple dispersion centres and a more complex flow structure.

Osteohistological characteristics of the large temnospondyl amphibian Metoposaurus diagnosticus from the Upper Triassic of Poland (Krasiejów locality) were determined using vertebral intercentra thin-sections from different regions and growth stages. The intercentra showed a trabecular structure in both the endochondral and periosteal domains. Endochondral ossification developed first, and the primary bone occurs near the periphery with a higher degree of remodelling in the centre. Periosteal bone deposition begins later; first on the ventral side, continuing laterally and finally onto the dorsal side. Periosteal growth rate was initially very rapid, and then subsequently decreased in rate. In all sections, numerous remains of calcified cartilage are visible, which may indicate a juvenile, paedomorphic or plesiomorphic character. The four histologic ontogenetic stages (HOS) of sampled vertebrae were determined based on growth marks. Most of the sampled bones belong to juvenile individuals (HOS 1 to 3), apart from one atlas and the largest anterior dorsal intercentrum, which represent the oldest described stage (HOS 4). Sharpey's fibres are preserved in ventro-lateral cortical regions, around parapophyses and on the posterior side of the neural arch.