The fin-to-limb transition is heralded as one of the most important events in vertebrate evolution. Over the last few decades our understanding of how limbs evolved has significantly increased; but, hypotheses for why limbs evolved are still rather open. Fishes that engage their fins to ‘walk' along substrate may provide some perspective. The charismatic frogfishes are often considered to have the most limb-like fins, yet we still know little about their underlying structure. Here we reconstruct the pectoral fin musculoskeletal anatomy of the scarlet frogfish to identify adaptations that support fin-assisted walking behaviours. The data are compared to three additional anglerfish species: the oval batfish, which represents an independent acquisition of fin-assisted walking; and two pelagic deep-sea swimmers, the triplewart seadevil and ghostly seadevil. Our results clearly show broad musculoskeletal differences between the pectoral fins of swimming and walking anglerfish species. The frogfish and batfish have longer and more robust fins; larger, differentiated muscles; and better developed joints, including a reverse ball-and-socket glenoid joint and mobile ‘wrist'. Further, the frogfish and batfish show finer-scale musculoskeletal differences that align with their specific locomotor ecologies. Within, we discuss the functional significance of these anatomical features in relation to walking, the recurring evolution of similar adaptations in other substrate locomoting fishes, as well as the selective pressures that may underlie the evolution of limbs.

The genus Machaeroprosopus has long been considered invalid because the type specimen of the Late Triassic phytosaur species, M. validus, has been lost. Re-examination of the primary literature regarding the establishment of the Late Triassic phytosaur genus Machaeroprosopus demonstrates that M. buceros is the correct type species, not M. validus. Thus, the genus level name Machaeroprosopus has priority over the genera Pseudopalatus and Arribasuchus and all nominal species should be reassigned. Reassignment of these species to Machaeroprosopus satisfies the requirements of the International Code of Zoological Nomenclature (ICZN) and preserves historical context. The name Pseudopalatinae is retained as the valid clade name for these phytosaurs because its usage falls outside of the ICZN.

The section Farinosae was first denned by Pax (1) in 1889 with citation of P. farinosa and P. sibirica as representative species. He published at the same time his section Auriculatae. The only distinction given of apparent moment between the two sections is the shape and size of the capsule. In Auriculatae it is globose and included in the calyx, while in Farinosae it is cylindric and more or less exserted. This diagnostic character was found to be unsatisfactory, with the result that in 1905 Pax (2) in his Monograph combined the two sections under Farinosae. There was still an undercurrent of opinion that a division was justified, and at the Third Primula Conference in 1913 Bayley Balfour (3) reverted to the previous arrangement without, however, any stated reasons. At the Fourth Primula Conference held in 1928 the sections of the genus were reviewed by Smith and Forrest (4), who again subordinated Auriculatae to Farinosae. In 1932 appeared Bruun's Cytological Studies in Primula (5), with a detailed analysis of the species then available in cultivation. Here valid evidence was given that certain species assessed in the past as within Auriculatae did differ cytologically from the general run of species included without question in the Farinosae. But the cytological evidence taken alone tends to associate these Auriculatae with other species quite dissimilar from the broad morphological point of view. The problem is referred to again by Wright Smith (6) in his Hooker Lecture, where it is admitted that the cytological data do support the view that there is a degree of fundamental difference between the two sections. But the difficulty still remains of finding satisfactory macroscopic distinctions. The present authors have come to the conclusion that it is better to keep both under the general heading Farinosae rather than to separate them by slender and often misleading characters supported as these may be by the cytology. In any case much remains to be done on the cytological side, as the majority of the species are yet to be analysed, and for general purposes the incorporation of the cytological data in an analytical key would not be satisfactory.

Study of abundant phalangiotarbid (Arachnida: Phalangiotarbida) material – provisionally assigned here to Bornatarbus mayasii (Haupt in Nindel 1955) – from the Upper Carboniferous of Writhlington, UK, has revealed new information about some previously equivocal characters. The present authors report a trifurcate apotele, possible spiracles on sternite 5, and confirm the presence of 10 opisthosomal tergites plus a dorsal anal operculum. The affinities of phalangiotarbids are obscure, with most authors favouring affinities with Opiliones (harvestmen) and/or Acari (mites and ticks). Phalangiotarbida is scored for characters used in previous studies of arachnid relationships. A cladistic analysis based on 63 characters using 13 terminal arachnid taxa (plus a hypothetical outgroup), resolves Phalangiotarbida as sister group to (Palpigradi + Tetrapulmonata): the taxon Megoperculata sensu Shultz (1990). Even under cladistic analysis, the position of the Phalangiotarbida remains hard to resolve, but a prosomal sternite with distinct sclerites potentially groups them with the Megoperculata.

In the Session of 1867-8 I communicated to this Society a paper on the Dissipation of Energy, of which only a very brief abstract was published in the Proceedings. The main feature of that paper was the suggestion, as at least a valuable working hypothesis, that even in cases of the steady motion of heat, electricity, &c., the unexhausted energy is probably as small as possible, consistently with the conditions of each form of experiment.

The early tetrapod Crassigyrinus scoticus was a large aquatic predator from the mid Carboniferous (late Viséan or early Serpukovian) of Scotland, around 330 My in age. There are five main specimens with cranial remains: an articulated skeleton; two incomplete skulls; and two lower jaws. Crassigyrinus retains several apparently primitive features of the palatal dentition and lower jaw, and its phylogenetic position is disputed. A partial lower jaw resembling that of Crassigyrinus was discovered at Burnmouth in the Borders region of Scotland. The horizon in which it was found is dated as late Tournaisian, CM palynozone, around 350 My in age. Though it lacks dentition, the jaw preserves much of the postsplenial, angular and surangular, whose appearance externally and internally is almost identical to that of C. scoticus. Internally, the jaw shows a similarly limited extent of the suturing between the splenial series and the prearticular, a primitive condition. Externally, the type and distribution of dermal ornamentation closely matches that of C. scoticus, as does the deeply excavated and marginally positioned lateral line groove. As well as external and internal features, all specimens of C. scoticus are of similar skull size, though the Burnmouth jaw is somewhat smaller. If correctly attributable to Crassigyrinus, this specimen extends the existence of the genus by approximately 20 million years towards the base of the Carboniferous.

The rapid advances made of late in the diagnosis of cardiac and other diseases affecting the organs of circulation, render the present inquiry into the normal or healthy condition of the valves of the vascular system, not more important anatomically, than medically. As the nature and composition of the parts in which valves are found in some instances materially influence their action, I have deemed it necessary to advert briefly to the properties and structure of the veins and arteries, when describing the venous and arterial or semilunar valves; and to the arrangement of the muscular fibres in the ventricles, when pointing out the peculiarities of the auriculo-ventricular ones. As, moreover, much information is to be obtained by comparing analogous structures, I have, in the present instance, not confined my observations to any particular form of valve, but have examined in succession the entire valvular arrangements of the fish, the reptile, the bird, and the mammal; my object being to arrive, if possible, at a correct knowledge of the more elaborate varieties as they exist in man, and in the higher mammalia.

The ascent of silicic magmas in dykes and diapirs on Venus is investigated using magma transport models for granitic melts on Earth. For fixed planetary thermal and melt properties, differences in critical minimum dyke widths, and hence magma ascent rates, are controlled by gravitational strength alone. For density contrasts of 200–600 kg/m3 and a solidus temperature of 1023 K, minimum critical dyke widths (wc) on Venus range from c. < 1–1200 m for a transport distance of 20 km. Dyke widths are especially sensitive to small changes in the far-field lithospheric temperature at values close to a critical Stefan number (S∝crit) of 0·83 where dyke magma temperatures are equal to the mean surface temperature. Typical magma ascent rates range from 0·02m/s (ηm = 105 Pa s) to 10−9 m/s (ηm = 1017 Pa s) giving transport times of between 12 days and c. 105 years. Dyke ascent velocities for highly viscous melts are compared with diapiric rise of a hot Stokes body of radius comparable with the pancake dome average (c. 12 km), and require dyke widths of the order of 100 times the average width of low viscosity flows to prevent freezing. In both cases, magma flow is characterised by Péclet numbers between 1 and 4, although even at high viscosities (> 1014 Pa s), dyke ascent is still 100 to 1000 times faster than diapiric rise. At a melt viscosity of 1017 Pa s, critical dyke widths are between c. 1% and 5% the diameter of an average width pancake dome on Venus, indicating that even for extreme melt viscosities, domes can easily be fed by dykes. Given the abundance of dome structures and associated surface features related to hyperbasal magmatism, batholithic volumes of silicic rocks may be present on Venus. Intermediate to high silica melts formed by partial melting of the Venusian crust should be compositionally more akin to Na-rich terrestrial adakites and trondhjemites than calc-alkaline dacites or rhyolites.

There is a general consensus that the global chemistry of ocean water has not changed markedly during the Phanerozoic. Nevertheless, significant changes have occurred in the geochemical cycles of some elements and patterns of change have been reconstructed, in various forms, through consideration of the isotope ratios 13C/12C, 34S/32S, 87Sr/86Sr and 143Nd/144Nd. There have also been attempts to constrain variations in the isotopic composition of sea water itself through measurements of D/H and 18O/16O, the latter both directly and indirectly. Dissolved constituents in seawater display secular changes in isotopic composition as a consequence of quite different driving mechanisms. δ13C and δ34S variations are broadly correlated and linked by carbon and sulphur exogenic cycle interaction through redox reactions (the “free oxygen cycle”). The 87Sr/86Sr trend is determined by the balance among different Sr inputs to the oceanic pool, which vary in their isotopic composition (limestones, old granitic material and young basaltic material). Neodymium isotope variations are not globally synchronous. Changes in 143Nd/144Nd are influenced by local erosion products from continental landmasses and can therefore be different for coexisting palaeocean basins.

Soil moisture is a key issue for eco-hydrological research in arid and semi-arid regions, and is primarily concerned with water availability for vegetation. Shallow and deep soil moisture occurs according to the maximum infiltration depth. Soil moisture has three-dimensional characteristics: inter-layer variability, horizontal heterogeneity and temporal variability. Soil moisture is affected by various factors including terrain, soil characteristics, climate and vegetation, and the effects of these change with time (e.g., rainfall patterns) and space (e.g., soil depth). In arid and semi-arid regions, deep soil moisture is of particular importance to vegetation restoration and the evaluation of vegetation sustainability; however, accurate prediction of the spatial distribution of deep soil moisture in the Loess Plateau of China still faces numerous challenges. Therefore, future research should focus on the mechanisms, models and scale effects of soil moisture, particularly for deep soil moisture.

Detailed descriptions and illustrations are presented of the structure of three representative species of tropical shipworms, Nausitora hedleyi, Teredo furcifera and Teredora princesae. The disposition of the various organ systems is described and illustrated with notes on the histology of the different regions so as to throw light on the adaptations and specializations of these unusual bivalves. The trend of evolution within the Teredinidae is discussed in the light of the available evidence contained in the present morphological studies.

The present investigation was undertaken to throw some light upon the nature and mode of action of the peripheral nervous mechanism of the uterus.

Previous work has demonstrated that the organ, like other viscera, has an autonomic action. That the uterus and vagina can function independently of the central nervous system has been shown both clinically and experimentally by Sir J. Y. Simpson (1), Goltz (2), Riemann (3), Rein (4), Kabierske and Heidenhain (5), Masius (6), and Kurdinowsky (7).

The nervous mechanism of the uterus may be divided into a central and a peripheral part.

Two new species of Ordovician echinoderms are described: Pleurocystites mitratus from the Kiln Mudstones (Caradoc) at Craighead, and Homocystites beggi from the Starfish Bed (Ashgill) of Threave Glen. Description of the former necessitated a review of the composition and status of the family Pleurocystitidae. The genus Dipleurocystis Jaekel 1918 and the subgenera Pleurocystites s.s. and Pleurocystella Paul, 1967 are rejected. The number and type of pectinirhombs; size of the periproct, composition of its border and nature of its covering plates (periproctals), and the ornament of the thecal plates and proximal columnals, are the most useful taxonomic criteria within the Pleurocystitidae. Pleurocystites mitratus is characterized by three conjunct pectinirhombs, a symmetrical theca without a rectal lobe and small periproctals each with a central pit. Homocystites beggi is distinguished from the closely related H. constrictus by strong granular ornament on the thecal plates.

Other echinoderm remains include plates of a cheirocrinid cystoid from the Kiln Mudstones.

Ice deposits from Greenland and Antarctic ice sheets have stored over long periods of time information about the climate and environment of our planet. Attention will be focused on the 2083 m Vostok Antarctic ice core which represents a unusually long record (160 000 ka) due to the low accumulation rate (∼2 g cm−2a−1) and the rather uniform conditions of ice flow. This ice core provides a unique opportunity to obtain several palaeo-data such as temperature, accumulation (precipitation), aerosol loading, CO2 and trace gases over a full glacial-interglacial climatic cycle.

The Vostok temperature, deduced from the interpretation of the deuterium content, and the CO2 records show a large 100 ka signal with a change of the order of 10°C and 70 ppmv respectively. The two records are closely correlated and both display shorter periodicities characteristic of the earth orbital parameters. CH4 concentrations also show variations from about 0·35 to about 0·65 ppmv linked with the glacial-interglacial warming. These features suggest a fundamental link between the climatic system and the carbon cycle and stress the role of radiatively active gases in climatic changes.

The accumulation (precipitation) record appears to be governed by temperature with values during the coldest stages reduced by a factor of 2 with respect to the present rate. Ice deposited during these coldest stage is also characterised by high concentration of marine and terrestrial aerosols; these peaks probably reflect strengthened sources and meridional transport during full glacial conditions, linked to higher wind speed, more extensive arid areas on surrounding continent and a greater exposure of continental shelves.

In his Presidential Address to the Royal Society of Edinburgh in October 1920, Professor Bower (2) called attention to the question of Size in relation to stelar morphology, and advanced evidence (with particular reference to the Filicales) to show how the principle of similar structures has affected the internal morphology of the vascular system of plants. In dealing with the application of this principle he remarks that “the stems and roots of most plants are approximately cylindrical. The same is the case as a rule for their conducting tracts also. The cylinder is one of those solid forms in which the proportion of external surface to bulk is exceptionally low. Any deviation from the cylindrical form, either by external projections or by involutions, necessarily leads to an increase in the proportion of surface to bulk. The surface varies only as the square of the linear dimensions, but the bulk as the cube. It follows, therefore, that in carrying out any of those physiological functions of a living organism which depend on surface, as do all those of the acquisition and inter change of material, the actual size of the part which exercises that function is a matter of the greatest moment. The larger the plant is, the more dependent will it then be upon its form and detailed structure, not only for its stability, but also for the performance of its functions of absorption and transit of liquids and gases. This will apply not only to the external surface, but also to those internal surfaces which limit one tissue tract from another.” In illustration of this, examples were taken from the stems, tubers, and petioles of the Filicales, and the size-factor was also found applicable to the large prop-roots of palms, such as Areca and Verschaffeltia.

Experimentally constrained calibrations of the incorporation of H2 O and CO2 into cordierite as functions of P–T-aH2O-aCO2 are integrated with KFMASH grids which define mineral-melt equilibria in pelites. This is used to explore the impact of the volatile content and composition of cordierite on anatexis and melt-related processes in high-temperature (HT) and ultra-high-temperature (UHT) metamorphism. The strongly temperature-sensitive H2O content of cordierite coexisting with dehydration melts (0·4–1·6 wt.%) causes a 10–25% relative decrease in the amount of melt produced from pelites compared with models which treat cordierite as anhydrous.

KFMASH melting grids quantified for aH2O demonstrate consistency between the measured H2O contents in cordierite from granulite-migmatite terrains and mineral equilibria. These indicate anatexis with aH2O in the range 0·26–0·16 at 6–8 kbar and 870–930°C. The pressure-stability of cordierite+garnet with respect to orthopyroxene+sillimanite+quartz in KFMASH is strongly influenced by cordierite H2O content, which decreases from 1·1 to 0·5 wt.% along the melting reaction Grt+CrdH+Kfs=Opx+Sil+Qz+L. The lower-T invariant point involving biotite (8·8 kbar/900°C) that terminates this reaction has aH2O of 0·16±0·03, whereas the higher-T terminating invariant point involving osumilite (7·9 kbar/940°C) occurs at aH2O 0·08±0·02. Osumilite-bearing assemblages in UHT terrains imply aH2O of <0·08, and at 950–1000°C and 8–9 kbar calculated aH2O is only 0·04–0·02. Cordierites stable in osumilite-bearing assemblages or with sapphirine+quartz have maximum predicted H2O contents of ca. 0·2 wt.%, consistent with H2O measured in cordierites from two sapphirine-bearing UHT samples from the Napier Complex.

The addition of CO2to the H2O-undersaturated (dehydration-melting) system marginally decreases the temperature of melting because of the stabilisation of cordierite, the solid product of the peritectic melting reactions. The preferential incorporation of CO2 enhances the stability of cordierite, even at fixed aH2O, and causes the stability fields of Grt+Crd+Sil+Kfs+Qz+L and Grt+Opx+Crd+Kfs+Qz+L to expand to higher pressure, and to both higher and lower temperatures. The minimum solubility of H2O in granitic melt is independent of the CO2 content of cordierite, and the distribution of H2O between melt and cordierite is similar at a given melt H2O-content to the H2O-only system. This enhanced stability of CO2-bearing cordierite leads to a reduced stability range for osumilite-bearing assemblages to temperatures of ca. 950–975°C or greater. Cordierites in the Napier Complex UHT gneisses contain 0·5 and 1·05 wt.% CO2, consistent with a role for CO2 in stabilising cordierite with respect to osumilite in these unusual sapphirine-bearing granul

The mode of occurrence of borosilicates and the breakdown fronts of prograde tourmaline (tourmaline-out isograd) in three anatectic migmatite regions of the Ryoke metamorphic belt, SW Japan, are reported. The breakdown of tourmaline in the migmatite zones and release of boron into the melts, followed by the extraction of the boron-bearing melts from the migmatite zones occurred throughout the Ryoke metamorphic belt. Retrograde, magmatic tourmaline in interboudin partitions filled with leucosome is useful for calculating the degree of partial melting in the migmatites. Using boron contents in the leucosomes and pelitic schists, the degree of partial melting at the migmatite front of the Aoyama area is estimated to be 12 wt.%. Extraction of the boron-bearing melt is suggested by the boron-depleted nature of the migmatites. Connection of boudinage structures probably supplied the vertical pathways of the segregated melts, and major transport of the melts was accomplished by dyking. Irregularly shaped, amoeboid tourmaline locally occurs on the high-temperature side of the tourmaline-out isograds in the Yanai and Komagane areas, implying incomplete extraction of boron-bearing melts from those areas. Discriminating retrograde from prograde tourmaline enables correct recognition of the tourmaline-out isograd. The amount of retrograde tourmaline in migmatites can potentially be used as an indicator of the degree of melt extraction from them.

Minute, lamellose concentric micro-frills are described on the external surfaces of the Devonian brachiopod Athyris campomanesi (Verneuil & Archiac). The micro-frills are very regularly spaced with a separation of approximately 0.5 mm, are inclined anteriorly and antero-laterally, and become more or less recurved peripherally down towards the valve surface. These micro-frills must have been secreted by outward extensions of epithelium, presumably resulting from an increase in the rate of cell proliferation or extension in the marginal zone. Extrapolating from the known growth rates of living brachiopods, it seems probable that the micro-frills formed very rapidly, within a matter of days or hours. In life the micro-frills would have formed minute channels around the peripheries of both valves, similar in form and function to rain gutters. As such they probably functioned as baffle chambers, within which excess paniculate material from the inhalant feeding currents would have accumulated. Such particulate material is likely to have been moved laterally from the median axis of the shell down to the sediment surface under the effects of gravity and in vitro shell movements. Each micro-frill may only have functioned in this fashion for a matter of weeks before being rendered ineffective by the forward growth of the valve margin, at which stage it would have been abandoned and replaced by a subsequently formed micro-frill.

The Pliocene Hipparion from La Gloria 4, La Calera, Orrios 1 and 3, Villalba Alta Río 1, Villalba Alta (Teruel basin) and Layna (Soria province), all in Spain, and Dorkovo (Sofia, Bulgaria), are described and tested by multivariate analysis. These Spanish and Dorkovo forms are compared with the specimens from Pavlodar (large-sized) and Kalmakpai (both in Kazakhstan), Çalta (large-sized, Turkey), the Roussillon (France) and Alcoy (Spain). The faunal assemblages indicate an Early and Late Alfambrian age (Ruscinian, MN14 and MN15) for the Spanish Hipparion and Early Alfambrian (MN14) for Dorkovo specimens. Hipparion remains from Pliocene Spanish localities show a very similar structure. They are referred to Hipparion fissurae, except Orrios 1 assigned to Hipparion aff. H. fissurae and Villalba Alta classified as Hipparion cf. H. fissurae. Despite certain relationships between Hipparion from Layna and Pavlodar, the multivariate analysis confirms the independence of both forms: H. fissurae in Layna, and H. longipes in Pavlodar. The specimens from Kalmakpai present many features close or intermediate to Layna and Pavlodar forms. Finally, Hipparion from Dorkovo is determined as Hipparion cf. H. crassum. These remains have a great morphological resemblance to H. crassum from Roussillon.

Serpentinites are a major component in a distinctive suite of metasedimentary and metamorphosed igneous rocks, the Outokumpu association, in the early–middle Proterozoic Svecokarelides of eastern Finland. Like the adjacent mica schists and associated supracrustal rocks, they show the effects of at least six phases of deformation (D1–D6). The tectonic history began with the emplacement of the Outokumpunappe (pre-D1), but a study of relict assemblages in the serpentinites and theirenvelope rocks reveals evidence for a complex pre-nappe history involving ultramaficmagmatism with extensive high-temperature hornfels development, and low-temperature serpentinisation contributing to sea-floor exhalation of sulphide ores.

The serpentinites subsequently underwent recrystallisation during several phases of regional metamorphism giving rise to mineral fabrics, including a pressure-solution initiated segregation (M1–D1), anthophyllite growth during the thermal climax (D2–M2—600–680°C, 2·5–4 kb), and steatitisation (D2c–M2c). Steatitisation is structurally controlled, occurring where serpentinite bodies impinge upon localised shear zones (wrench faults—D2c). Talc–carbonate–brucite assemblages reflect the influx of CO2 in this environment. Deformation during late metamorphic retrogression (greenschist—D3–D4) has a dichotomous expression with crenulations developed in strongly anisotropic phyllonitised serpentinite and irregular fracturesin massive rock.

The implications of such polyphase reconstitution for geochemical and isotopic studies are assessed and discussed.