In 1858 C. H. Pander described as Ptydodus a number of teeth from Upper Devonian limestones in Russia. His admirable figures of complete teeth and of sections through them established the very chimæroid structure of these bodies. Since that time similar teeth have been repeatedly described, and have served for the establishment of three genera and many species from rocks of Middle and Upper Devonian age.

It has been known from antiquity that involution of the uterus is aided by putting the child to the breast, and the work of Moir (1933) has demonstrated conclusively that suckling brings about waves of contraction of the puerperal uterus. Since suckling must necessarily involve stimulation of the nipple, it seemed of interest to know what sensory apparatus is present in the nipple to receive these stimuli. While histological studies of the mammary gland itself have been numerous, only slight attention has been paid to the histological structure of the areola and the nipple.

It must be appreciated from the outset that the present study is devoted to the innervation of the nipple in the quiescent breast. There may be considerable change during pregnancy and lactation, not only in the size of the organ and its epithelium but also in the other structures. It has been shown that there is an increase in the number of nerve-fibres in the actively secreting mammary tissue, and it is possible that there is an increase in the nerve-structures of the nipple also. The richness of the innervation in the quiescent nipple certainly makes a further study of these nerve-structures during pregnancy and lactation of great interest.

The cranial anatomy of the primitive Carboniferous temnospondyl Cochleosaurus bohemicus is described herein from several large, presumably adult, skulls. This new morphological data modifies earlier descriptions by Frič (=Fritsch in post-1876 publications), Romer and Steen, which were based almost entirely on small, subadult Cochleosaurus bohemicus specimens. Recognition of a new autapomorphy for Cochleosaurus bohemicus, (pitting on the ventral surface of the postorbitals) which is independent of ontogenetic change, has facilitated more accurate intra-specific comparisons between cochleosaurids. Cladistic analysis reveals a clear dichotomy separating the Edopoidea from the more derived clade of the remaining temnospondyls, which includes Balanerpeton and Dendrerpeton. The Edopoidea are only weakly supported as a superfamily in this analysis. The Cochleosauridae are a monophyletic family comprising the genera Procochleosaurus, Adamanterpeton, Cochleosaurus and Chenoprosopus.

Previously described and new specimens of the anthracosaur Silvanerpeton miripedes from the Scottish Viséan of East Kirkton yield important new data which allow us to provide a more complete reconstruction of the skull roof, palate, braincase and lower jaw. A stout sacral rib and an incompletely ossified tarsus with a subquadrangular intermedium are also recorded for the first time. A remarkably well preserved humerus in extensor view shows similarities with humeri of immature specimens of the embolomere Proterogyrinus. A new cladistic analysis, built from combining characters used in two recent matrices, places Silvanerpeton in a basal position relative to embolomeres and more derived stem amniotes. Data from Silvanerpeton inform character polarity near the base of the amniote total group. We discuss some morphofunctional implications of character changes at the root of total group amniotes, acquisition of terrestrial habits, and patterns of early disparity in this clade.

The Topsails igneous terrane of western Newfoundland contains several intrusive and volcanic suites underlain and separated by screens of older intrusive rocks. The heterogeneous Hungry Mountain complex yielded U-Pb zircon upper and lower intercept ages of 2090 ± 75 Ma and 467 ± 8 Ma, demonstrating a significant inherited component of Aphebian age, while an adjacent suite of relatively massive granodioritic to granitic rocks yielded a slightly discordant U-Pb zircon age of 460 ± 10 Ma. The 438 ± 8 Ma age of the Rainy Lake complex, a suite of island arc type intrusive rocks, suggests it forms part of a Silurian magmatic episode, which also included Springdale Group bimodal volcanics (429 ± 4 Ma), and peralkaline granite and subvolcanic porphyries which intrude the Springdale Group (429 ± 3 Ma and 427 ±3 Ma, respectively). Most igneous units contain a slight component of inherited zircon, but initial 87Sr/86Sr ratios (average 0·704) are similar to calculated ‘Bulk Earth’ values at this time.

Available data suggest that the Topsails terrane formed an oceanic tract with active volcanic island arcs when obduction commenced in early Ordovician time. The subsequent magmatic history, including the major but short-lived early Silurian magmatism, can be directly or indirectly related to obduction processes, including over-riding of the Topsails terrane by ophiolitic allochthons. There is no evidence of any Acadian (Devonian) igneous activity in the Topsails terrane.

So barren of fossil remains is the Cementstone Group of the Scottish Lower Carboniferous Rocks that any addition to our knowledge of the fauna and flora of the period is especially welcome. The list of vertebrate remains is notably meagre, and such as have been found, e.g. at Abden, are generally very fragmentary.

The collection to be described below contained nearly 150 specimens, and includes Plants, Lamellibranchs, Annelids, Arthropods, and Fishes: of these the Plants and Fishes are by far the most important, and constitute more than two-thirds ot the total number of specimens.

Earliest Silurian (basal Llandovery) brachiopod faunas are surveyed and listed from around the globe, and divided between Lower Rhuddanian and Upper Rhuddanian occurrences. 60 genera are known from the Lower Rhuddanian within 20 superfamilies and there are 87 genera in 25 superfamilies in the Upper Rhuddanian. The 29 areas surveyed span the globe, both latitudinally and longitudinally. Only six superfamilies are Lazarus taxa which are known both from the Ordovician and Middle Llandovery (Aeronian) and later rocks but have not been recorded from the Rhuddanian. These are surprising results, since many previous studies have inferred that the Rhuddanian was a time of very sparse faunas. The global warming that followed the latest Ordovician (Hirnantian) ice age did not proceed quickly, with an ice-cap probably present through at least the Llandovery. There is a marked absence of Lower Rhuddanian bioherms even at low palaeolatitudes; however, the ecological recovery rate was far faster than that following the end-Permian mass extinction event. The partitioning of the Rhuddanian shelf faunas into well-defined benthic assemblages progressed slowly over the interval.

Descriptions of the two Coal Measure plants Senftenbergia and Dactylotheca have appeared in the literature on numerous occasions previous to this account. The former genus was first described by Corda (1845), and the latter by Zeiller (1883). Other contributions have been made by more recent investigators, and these have since been revised and supplemented by Kidston (1924). In each case the account was based upon an examination of the material as it appeared on the rock in the form of a compression. More recently, however, newer methods for dealing with plant compressions have been devised, and it was felt that the application of an improved technique would furnish a more adequate description of the plants, particularly of their fruiting members.

Since the time when Agassiz and Buckland made known the former presence of glaciers in the mountain valleys of North Wales, much has been written concerning the glaciation of Snowdonia, but comparatively little attention has been given to that of Western Carnarvonshire. This part of the country stretches south-westwards as the broad promontory of Lleyn between Carnarvon Bay and Cardigan Bay. Western Carnarvonshire for the most part lay outside the paths followed by the native glaciers. None of the larger valleys of Snowdonia trend in this direction, and so the marks of recent glaciation are not so fresh and striking in this region as they are further east. Hitherto no one has attempted to give any detailed account of the Drift deposits over the whole of Lleyn, but various references to the glaciation of the region are found scattered in the literature dealing with the geology of Wales.

The district in which the city of Edinburgh is situated was one of the first in Britain from which fish-remains of Carboniferous age were collected. It is now sixty-seven years ago since Agassiz described the fossil fishes which were discovered by Lord Greenock at Wardie. Dr Hibbert at Burdiehouse, and Professor Jameson at Burntisland. The list given from this region in the “Tableau Générale” at the beginning of the Poissons Fossiles comprises twenty-nine names, of which eight were nomina nuda and are not now verifiable, the original specimens being lost; one, Diplodus minutus, was described, but insufficiently, and the original is also lost; six are synonyms of others in the list; leaving fourteen good species, of which one, Ptychacanthus sublævis, is a synonym of a Selachian spine (Tristychius arcuatus), described and figured from the Glasgow district.

The monotypic ostracode Entomozoe (pro Entomis) (Superorder Myodocopa) from the Silurian of Scotland, type genus of the Entomozoidae, is revised for the first time since being established in 1861. Based on the type and new collections of Entomozoe tuberosa (Jones, 1861), the genus shows affinity to bolbozoid myodocopes rather than to forms hitherto universally considered as ‘typical’ entomozoid myodocopes. The families Entomozoidae and Bolbozoidae are considered synonymous. In the interests of stability of nomenclature, in particular to preserve the traditionally understood usage of the taxon Entomozoidae, a case must be made to the International Commission on Zoological Nomenclature to set aside any previous designations and to establish a new type-species for Entomozoe.

Entomozoe, from the Llandovery Series, is the earliest known myodocope in the fossil record. It occurs as part of a low diversity, shallow water, nearshore assemblage. In contrast to other, but younger, Silurian bolbozoid myodocopes, it is probably a benthic form. The differences in the anterior shell morphology of Silurian bolbozoid taxa possibly reflect changes both in soft-part morphology and from benthic to pelagic lifestyles within the group.

Both bolbozoid and ‘entomozoid’ myodocopes are assigned to the Order Myodocopida rather than to the Order Halocypridida, though the taxonomic affinity of the ‘entomozoids’ is, at best, uncertain.

Triradioxylon gen. nov. is erected for petrified stems and petioles in which the primary xylem has a triradiate form and possesses protoxylem at the ends of the arms and in the central region. Secondary xylem is dense and composed of small tracheids having multiseriate bordered pits on all walls. Rays are narrow and high. The cortex has sclerotic nests and radial bands of fibres (sparganum structure).

In the type species T. primaevum sp. nov. the petioles are borne 5–6 cm apart in a phyllotactic spiral of ⅓ on a stem about 1 cm (or more) diameter. The petiole is swollen at its base (about 8 mm diameter) and very gradually tapers to about 2 mm in the rachis which has not been seen to dichotomise. The length of petiole up to the first pinna may exceed 10 cm. Pinnae arose alternately and themselves branched. The T-shaped petiolar bundle has two protoxylem groups at the end of each arm and the central protoxylem divided into three in the rachis.

Two detached rachises which cannot be assigned with certainty to Triradioxylon primaevum are placed in the genus Lyginorachis and named L. whitadderensis sp. nov. In these the T-shaped vascular bundle is slightly larger than that in the rachises of T. primaevum and the ends of the transverse arms are wider and may possess three protoxylem groups.

The rachises in both T.primaevum and L. whitadderensis bear alternate triarch pinna-traces but in L. whitadderensis a pair of sub-opposite monarch pinna-traces is also present.

Triradioxylon is classified along with Buteoxylon in the family Buteoxylonaceae placed tentatively as incertae sedis in the Pteridosperms although showing some affinity with Aneurophyton in the Progymnospermopsida.

In the course of an examination of Bishop Berkeley's “New Theory of Vision,” the foundation of the Ideal Philosophy, I have found it necessary to repeat many old experiments, and to make many new ones, in reference to the functions of the eye as an optical instrument. I had imagined that many points in the physiology of vision were irrevocably fixed, and placed beyond the reach of controversy; but though this supposition may still be true in the estimation of that very limited class of philosophers who have really studied the subject, yet it is mortifying to find that the laws of vision, as established by experiment and observation, are as little understood as they were in the days of Locke and Berkeley. Metaphysicians and physiologists have combined their efforts in substituting unfounded speculation for physical truth; and even substantial discoveries have been prematurely placed in opposition to opinions of which they are the necessary result.

The discovery of new specimens of Palaeonitella cranii (Kidston & Lang) Pia in the Early Devonian Rhynie chert permits the classification of this charophyte alga. This relatively small charophyte is composed of multicellular furcating branchlets with antheridia attached to the parent plant by a pedicel. The non-calcified gyrogonites, which are not seen in life position, are composed of six sinistrally spiralling cells and have six coronula cells arranged in a single layer around an apical pore.

Because the oogonia of P. cranii have six sinistrally spiralling cells and an apical pore, Palaeonitella has been assigned to the Palaeocharaceae. The shape and form of the oogonia is reminiscent of the extant Chareae, but the morphology of the thalli is indicative of the Nitelleae. This suggests that P. cranii, although retaining some characteristics of the Nitelleae, has some of the characteristics of the Chareae, supporting existing molecular studies which place the Nitelleae at the base of the Characeae.

Palaeonitella cranii inhabited the freshwater alkaline pools and streams which formed on sinter aprons created by hot spring activity. Extant charophytes exist in a similar environment (pH 8·66–8·9, temperature 25–30°C in summer) in pools and channels fed by hot springs in Yellowstone National Park, Wyoming, USA.

Articulated thelodonts, Loganellia scotica (Traquair), Shielia gen.n. taiti (Stetson), Lanarkia horrida Traquair, L. spinulosa Traquair and Turinia pagei (Powrie) from the Silurian and Devonian of Scotland are re-described. A new species, Lanarkia lanceolata sp.n. from the Wenlock, Lower Silurian, is established. For each species, diagnosis is specified, varieties of scale morphology are given, the branchial area is described and body morphology is detailed. A paired ventral fin in Shielia gen.n. taiti and Lanarkia lanceolata sp.n. has been discovered. A new reconstruction of Loganellia and Shielia, and diagnosis for thelodonts from Scotland are given. The locality list of Scottish agnathans is reviewed and the biostratigraphical distribution discussed.

Microfossil (pollen and diatom) evidence is presented from sites in the Forth valley, south-central Scotland, where alternating organic and estuarine minerogenic deposits record the influence of the changing Holocene sea level. Radiocarbon dating confirms the age of the Main and Low Buried Beaches, and of the Main Postglacial Transgression, in different parts of the Forth valley. Radiocarbon dates on shells from beds in the carse sediment and a Mesolithic shell midden near Grangemouth relate to the falling sea level in the 4th and 5th millennia BP. Sea-level curves are constructed for the western and eastern Forth valley.

I propose in this memoir to methedically connect several desultory notices, which I had occasion to read during the last session of the Royal Society's meetings, relative to the Limestones of fresh-water origin in the neighbourhood of Edinburgh, belonging to the carboniferous group of rocks, and to the organic remains which they contain.

Hitherto, the limestones belonging to this older class of deposits have been considered as exclusively of marine origin. I had long since, however, been prepared to expect that a limestone of a fluviatile or fresh-water origin would, some time or other, be proved to exist. For, in judging from analogy, it would be unreasonable to presume, that, when fresh-water limestones appear in the rocks of every later epoch, they should meet with an exclusion in the carboniferous group. In entertaining, therefore, less confined views, I was not at all surprised to find them confirmed in a limestone near Edinburgh, which lately came under my examination,—I allude to that of Burdiehouse. It enclosed none of the marine shells, corallines, or encrinites to be found in the other limestones of the vicinity, but contained in the place of them, and in the greatest possible abundance, the various plants observable in our coal-fields. I also procured from it specimens of fish allied to such as are obtained from beds associated with coal. These facts indicated to me that I had at length found a fresh-water limestone belonging to the carboniferous group of rocks.

Charnockite and homophanous leptynite are two quartz–feldspar neosomes in the late Archaean granulite-migmatite Eastern Ghats terrane of Orissa, India. Three phases of deformation and metamorphism are recognised to have preceded a late phase, or phases in which deformation was not intense. An early granulite facies event (D1–M1) produced basic granulites and khondalite (sillimanite-garnet aluminous paragneiss). A second event (D2–M2) involved some retrogression but temperatures and pressures remained high (possibly c. 750°C—>5 kb). D3–M3 was associated with the development of open folds (F3) with axial planar shear zones in pinched antiforms; temperatures and pressures were also falling (c. 650°C— 4kb), but the shear zones acted as a control on the development of firstly homophanous leptynite, and secondly charnockite. In both cases, neosomes of quartz and potassium feldspar have myrmekitic textures and intergranular occurrence. The palaeosome became strained and garnet–biotite and garnet–biotite–clinopyroxene ± orthopyroxene mineral assemblages were formed in association with the development, respectively, of homophanous leptynite and charnockite. The persistence of straining in the palaeosome and the presence of poikilitic textures indicate that this typical assemblage does not represent one in thermodynamic equilibrium. This has important consequences for geothermobarometry.

The structural control on neosome development reflects a regional characteristic where shear zones are the site of peralkaline plutons, fenitisation, carbonatites and epigenetic graphite development. The peculiar features of charnockite are seen as just one of several aspects related to the fluxing of hot CO2-dominated fluids from either the deep crust or mantle during the late Archaean development of the Indian craton.

This investigation first commenced in the examination of a few special points which had arisen in connection with Professor Ewart's investigations on the Cranial Nerves and Lateral Sense Organs of Elasmobranchs. As this examination revealed facts of more interest than was expected, it occurred to me to investigate very thoroughly the whole of the cranial nerves of this animal, and to publish the results as a continuation of the work already alluded to. The research turned out to be much easier and more interesting than I had anticipated, and, as regards its cranial nerves at any rate, Chimæra is unrivalled among vertebrates, first, for the ease with which its nerves may be dissected, and second, for the almost ideal results that are to be obtained. The endless perplexity and mystification produced by the study of the trigeminal and facial nerves of the cartilaginous fishes,—dispelled to a very great extent, it is true, by the researches of Marshall and Spencer,—would probably have never arisen if Stannius had made a careful examination of the roots of the 5th and 7th nerves of his Chimæra. This, however, he omitted to do in the very form—in fact, as far as we know, the only form—which would have repaid the investigation ; and hence the embryologist stepped in and made a discovery that the anatomist had just, and only just, failed to grasp. The more important facts, therefore, relating to the cranial nerves of the Holocephali are, it is claimed, here recorded for the first time.

Marine shelf siliciclastics of the early Cambrian Buen Formation of North Greenland have yielded the earliest abundant, well localised Bradoriida (Arthropoda) from the Laurentian part of North America: the shelf-dwelling Petrianna gen. nov. Petrianna apparently has a fairly rigid, phosphatic shell. Its assignment to the Cambriidae, a family markedly dissimilar morphologically from the phosphatocopines (the only Bradoriida hitherto regarded as having a primary phosphatic shell), implies rejection of the criterion of carapace composition in the ordinal/subordinal classification of Bradoriida.

Petrianna confirms the Bradoriida as a consistent component of the earliest arthropod faunas. Cambriids are currently known only from the early Cambrian of Greenland, Siberia and China and offer potential for correlation. Cambriid occurrences span parts of the Redlichiid, Olenellid and Bigotinid trilobite faunal realms but are known only from tropical/subtropical regions, thus indicating possible palaeolatitudinal controls on their distribution.