The holotype and only known specimen of Rhachiosteus pterygiatus Gross is partially redescribed and new restorations are given. Attention is drawn to important points in its osteology and the possible development of a cutaneous sensory system. A definition of the family Rhachiosteidsæ Stensiö is given. This family differs from all other described groups of euarthrodires in the lack of posterior lateral and posterior dorsolateral flank plates. Rhachiosteus is a pachyosteomorph brachythoracid, as defined in the text, and may be fairly closely related in some way to the (coccosteomorph) family Coccosteidsæ. There is no indication that it is closely related to any other known pachyosteomorph, or to other groups of arthrodires, such as the Rhenanida and Ptyctodontida, in which there are no posterior flank plates.

Notoungulates, native South American fossil mammals, have been recently objective of several palaeoecological studies. Ecomorphology and biomechanics of the masticatory apparatus, together with micro and mesowear analyses on tooth enamel, were applied in order to understand their palaeobiology. In particular, the relationship between some dental traits (hypsodonty, occlusal surface area and complexity) and body mass is still poorly understood. These features were measured by means of the hypsodonty index (HI), occlusal surface area (OSA) and tooth area (OTA), enamel crest complexity (ECC) and length (OEL). The relationships between these indices were evaluated in five pan-contemporaneous Santacrucian Notoungulata genera from Patagonia: Adinotherium and Nesodon (Toxodontia), Interatherium, Protypotherium and Hegetotherium (Typotheria). While OSA, OTA and OEL were size dependent and strongly correlated, HI and ECC were size independent. All notoungulates analysed have very hypsodont teeth, indicating high rates of tooth wear in response to an increase of abrasives consumed with the food; their tooth occlusal area and complexity could be related to chewing efforts associated with the toughness of the plants consumed. HI, OSA and ECC were considered useful for palaeoecological reconstructions, but the results presented here show that these three features are integrated as a complex, so should not be evaluated separately.

Felsic magmatism has occurred over a large region of East Asia since Jurassic times and has provided important mineral resources such as tin, tungsten, base metals and gold. The circum-Japan Sea region preserves various geological records of active continental margins, including Jurassic to Early Tertiary magmatic arcs and subduction zones and pre-Jurassic continental basements, which were separated by the opening of the Japan Sea during the Miocene. The felsic magmatism in this region shows a wide variation in terms of redox state and related mineralisation, encompassing east–west contrasts around the Pacific Ocean. A review of granitoids and associated ore deposits in this region indicates that the character of the crust, sedimentary versus igneous, is an essential factor to control the redox state, and a tectonic setting may be an additional factor in some cases.

The reduced-type granitoids, characterised by tin mineralisation, were generated in carbonbearing sedimentary crust which was composed mainly of accretionary complex material and not influenced by previous magmatism. Involvement of sedimentary materials is corroborated by oxygen, sulphur and strontium isotope data. The oxidised-type granitoids, characterised by gold or molybdenum mineralisation, were generated in igneous crust which was depleted in reducing agents as a result of previous magmatism. Granitoid magmatism in a given area tends to become more oxidised with time.

Jurassic accretionary complexes in East Asia are thought to have been largely displaced from the original place of accretion and stacked up against the northeastern margin in the Khingan and Sikhote–Alin Mountains. This region, dominated by sedimentary crust, was subsequently subjected to Cretaceous felsic magmatism and converted to a large province of reduced-type granitoids and tin–tungsten mineralisation. Diverse geodynamic processes, including the change of the arc-trench system, the creation and collapse of the back-arc basin and the collision of continents, may have prepared many favourable sites for the generation of reduced-type granitoids in northeast Asia. These processes may have resulted in a remarkable contrast with the Pacific margin of North America, where repeated arc magmatism during the Mesozoic formed granitoid batholiths of the oxidised-type.

The granitoid types may also be controlled by the tectonic setting and mode of magma emplacement. In the northern Kitakami area of Northeast Japan, Early Cretaceous episodic magmatism occurred in a Jurassic accretionary complex, and formed the oxidised-type granitoids accompanied by submarine bimodal volcanism associated with kuroko mineralisation. Granitoids of fissure-filling type emplaced under extensional environments may be oxidised, irrespective of basement geology, because of insignificant crustal input.

In a Review of Dr Stur's Zur Morphologie und Systematik der Culmund Carbonfarne, I pointed out that he appears to have included two types of fern fructifications in his genus Calymmatotheca.

The first type includes those forms originally placed in Calymmatotheca and consists of a number of exannulate sporangia arranged around a common point of attachment; the second type, which was first described in Zur. Morph., u. Syst. d. Culm- u. Carbonfarne, is there represented by C. Avoldensis and C. Frenzli. The fruit of these two species is apparently surrounded by an involucre or indusium, and it is only with this part of the fructification that we are at present acquainted. I also further indicated that in Calymmatotheca, as I proposed to restrict the genus, the fruiting portions of the frond are entirely deprived of foliage pinnules, whereas in the other type (C. Avoldensis and C. Frenzli) only a very slight modification takes place in the fertile portion of the fronds—the sporangia being borne on the ordinary foliage pinnules.

Since the time when Astronomy emerged from the obscurity of ancient fable, nothing is better known than its progress through the different nations of the earth. With the era of Nabonassar, regular observations began to be made in Chaldea; the earliest which have merited the attention of succeeding ages. The curiosity of the Greeks was, soon after, directed to the same object; and that ingenious people was the first that endeavoured to explain, or connect by theory, the various phenomena of the heavens. This work was supposed to be so fully accomplished in the Syntaxis of Ptolemy, that his system, without opposition or improvement, continued, for more than five hundred years, to direct the Astronomers of Egypt, Italy and Greece. After the sciences were banished from Alexandria, his writings made their way into the east, where, under the Caliphs of Bagdat, Astronomy was cultivated with diligence and success. The Persian Princes followed the example of those of Bagdat, borrowing besides, from Trebisond, whatever mathematical knowledge was still preserved among the ruins of the Grecian empire.

§ 1. The networks considered in the following paper are those networks of the plane whose meshes are regular polygons with the same length of side.

When the polygons are all of the same kind the network is called regular, otherwise it is semi-regular.

The regular networks have been investigated for the three geometries from various standpoints, the chief of which may be noted.

1. The three geometries can be treated separately. For Euclidean geometry we have then to find what regular polygons will exactly fill up the space round a point. For elliptic geometry we have to find the regular divisions of the sphere, or, what is the same thing, the regular polyhedra in ordinary space. The regular networks which do not belong to either of these classes are then those of the hyperbolic plane.

The group of the Phæosporeæ was first recognised by Thuret in 1850. It includes algæ that vary greatly in size, habit, external appearance, and mode of branching, some possessing a flat thalloid appearance with or without a long stalk (e.g., Laminariæ), others being filamentous and much branched (e.g., Ectocarpus, Sphacelaria, Chordaria, &c). The great majority of the genera included in the group are marine or brackish water forms, but recently E. Flahault has described, under the name of Lithoderma fontanum, a fresh water species from the neighbourhood of Montpellier.

The dimensional statistics and proximal development characters of the Llanvirnian pendent didymograptid D. murchisoni are defined using the type material from near Builth Wells (Powys) and other collections from Abereiddi Bay (Dyfed). Population variability (as expressed by variation coefficients) in the undeformed faunas amounts to about 10% for the sicula lengths and thecal spacings, but is over 20% (up to 200%) for stipe lengths and divergences. Characters with low variability have greater species-diagnostic value. Proximal development in the species involves a dicalycal th 11 and a low origin for that theca from the sicula. The taxa Didymograptus amplus, D. nanus, D. geminus, D. geminus latus and D. acutus are varieties within populations of D. murchisoni and are therefore junior synonyms.

The resulting rationalised taxonomy allows advances to be made in the use of the species in stratigraphy and tectonics. For example, an occurrence of undeformed (pyritised) D. murchisoni in full relief at Abereiddi in the same beds as flattened and deformed faunas, allows a calculation of the absolute three-dimensional strains to be made for the slates there. The strains are strongly flattening (K < 0 · 3) and involve volume changes of about −56%. The high dilatation values imply that stylolite and grain-boundary pressure solution operated during the deformations to take the changes in volume beyond what is possible with simple compaction (i.e. porosity reduction).

Total contents of 21 trace elements were determined in particle size separates from the horizons of four profiles, two freely drained and two very poorly drained, of Scottish soils on drifts of basic igneous and granitic origin. Trace elements, including Co, Cu, Li, Mn, Ni, V, Zn and also Fe contained in the more easily weathered ferromagnesian minerals, tend to accumulate in the clay and silt. Elements such as Ti and Zr and also La and Y contained in resistant minerals accumulate in the silt or fine sand. Ti and Zr are mobilised to some extent, however, as these elements are present in the clay separates and in some cases show enrichment therein.

The alkali metals Li and Rb accumulate in the silt and clay particularly in the granitic soils, while the alkaline earth metals Ba and Sr occur in greatest concentrations in the sands due to their being held largely in resistant feldspar minerals. On release these elements are not strongly adsorbed by the clay.

Very poor pedological drainage leads to increased weathering and release of such elements as Co, Cu, Ni, V and Zn from the coarse or fine sands with correspondingly greater enrichment of the associated silt and clay. Weathering and enrichment of the fine fractions takes place largely in situ, there being little evidence of downward translocation due to leaching.

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.

Dr G. S. Carter, on his expedition to the Gran Chaco of South America in the year 1926–27, collected a fairly complete series of the developmental and adult stages of Callichthys. Several species were represented among the adults obtained, but the developmental stages are almost entirely those of Callichthys (now called Hoplosternum) littoralis. Callichthys belongs to a small subfamily of freshwater fishes belonging to the group Siluridæ. The fish was first described under the name of Callichthys littoralis by Hancock (10). He gives a brief description of the external form and tells how the fish make a regular nest of leaves in which they lay the eggs, and which the male and female both guard most carefully.

In my previous papers on “The Meteorology of Edinburgh” the data referring to local climate were reduced down to the end of 1896. In the time that has elapsed since their publication a number of memoirs from places on the Continent and elsewhere have appeared in which the data, mostly dealing with long periods, were brought down to the end of 1900. In order to facilitate the comparison of the Edinburgh record with those referred to, I have completed new monthly and annual averages for the ten years 1891–1900, the fifty years 1851–1900, and for longer periods, which embrace 137 years in the case of mean temperature, 131 years for mean barometric pressure, 130 years for the non-instrumental phenomena, and 124 years for rainfall (see Tables I. to IV.). The values previously published have been carefully examined, and a number of errors which escaped detection at the time eliminated. A Table of Errata (see Table XXIX.) is appended. Tables V. and VI. show respectively the mean monthly and annual departure from the normal of the mean maximum and minimum temperatures for the fifty years 1851–1900. A few of the values formerly published (see Table XVIIL, Trans., vol. xxxix. pp. 130–133) are about 0°·6 too high, but they have been corrected.

The author summarises recent reports regarding the appearance in Mesozoic rocks of Blanckenhorn's genus Dictyoconus, long supposed to have originated in the Middle Eocene. He figures and describes the best known of these Mesozoic forms, in order to place its age and generic attribution beyond question, and discusses the problem of its relationship to allied genera as affected by its early appearance. He then describes d'Orbigny's contemporary (Cretaceous) genus Orbitolina, with which Dictyoconus has often been confused, in order to show its radical difference in structure and the characteristics of forms which can be more justly regarded as related to it. He also discusses the genotype of Orbitolina, since the species lately quoted as such is unsuitable.

The poetical beauties of Virgil's sixth book are great and many; and a most agreeable task it would be to point them out: but that is not my present purpose. Nor do I intend to draw a comparison of the sentiments of our poet with those of Homer, concerning a future state. From Homer, no doubt, Virgil received the first hint of this episode ; but the evocation of the ghosts, in the eleventh book of the Odyssey, is not in any degree so striking, or so poetical, as Eneas's descent into the world of spirits. Nor does the former exhibit any distinct idea of retribution. In it all is dark and uncomfortable. “I would rather, says the ghost of “Achilles, be the slave of a poor peasant among the living, “than reign sole monarch of the dead:” a passage blamed, not without reason, by Plato, as unfriendly to virtue, and tending to debase the soul by an unmanly fear of death.

The unique specimen on which this description is based is in the Geological Department of the Manchester University Museum (No. L. 8549). It is on a slab of dark grey flagstone measuring 26 × 21 cm. from the Hill of Forss, Waas, Caithness, the plant being spread out on the surface of the stone like a very complete herbarium specimen (Plate fig. 1). It was referred to and briefly described, but not named, in 1888 by Mr G. Edward, who discovered it, and from whom it passed with other Old Red Sandstone fossils into the Manchester collections. In his paper, Mr Edward called attention to “three of the largest and most perfect Old Red Fossil Plants that may be seen in any museum in the kingdom,” which he had found during his collecting expeditions extending over some thirty years. Two of the fossil plants he refers to can be identified in the Manchester University Museum. The one we are concerned with here is described as “a lovely bush-like plant with hundreds of ribbon or grass-like leaves that have pod, or pocket, or flower-like terminations.”

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

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

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

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

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

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

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

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

La collection d'Astéries, d'Ophiures et d'Échinides, dont M. le Dr. William S. Bruce a bien voulu me confier l'étude, comprend surtout les échantillons recueillis par l'Expédition de la Scotia lors de son séjour dans l'Antarctique et quelques autres provenant des îles Falkland, du banc de Burdwood et de l'île Gough, ou de dragages effectués entre le 46° et le 51° lat. S. M. Bruce y a joint quelques spécimens capturés pendant le voyage de retour de la Scotia, au Cap, à Sainte-Hélène, à l'Ascension et à Saint-Vincent.

The fjord-like inlets or sea-lochs which form so conspicuous a feature in the scenery of the west of Scotland stand in marked contrast to the shallow, low-shored firths of the east coast. When Dr John Murray decided to extend the physical and biological work of the Scottish Marine Station to the west coast he foresaw that many interesting conclusions were likely to be derived from the study of these isolated sea-basins. Various papers, published by him and other workers, contain preliminary discussions of many of the phenomena observed, fully justifying the anticipations which had been formed.

For one year my work, as described in this paper, was carried out under the provisions of an Elective Fellowship in Experimental Physics of the University of Edinburgh, to which I had been elected in 1886; and subsequently by a personal grant from the Government Grant Committee for Scientific Research. The Committee also devoted several sums of money in payment of expenses in compiling this discussion. The Scottish Marine Station throughout gave the use of the steam-yacht “Medusa,” and the necessary apparatus.

Sedimentary sequences in lower Strathspey provide a record of Late Pleistocene interglacial and glacial environments. After deposition of till and glacifiuvial sediments, probably in Oxygen Isotope Stage 6, a soil developed at Teindland and Redburn which contains downward translocated pollen. This indicates that the earliest vegetation was woodland with grassland openings, Pinus-Alnus at Teindland and Alnus-Corylus at Red Burn. Podzolisation of the soil ended with an influx of sands derived from erosion of the surrounding slopes, at Teindland perhaps a response to extensive burning during a grassland phase. The combined pollen and sedimentary evidence suggests events at the close of an interglacial. Luminescence dates of 79 ± 6 and 67 ± 5 ka for the sands over the soil suggest that the soil developed in Oxygen Isotope Stage 5e. Overlying the soil and sands at Teindland are glacigenic debris flows, perhaps reflecting glaciation during Oxygen Isotope Stage 4. Three, undated, younger till units, with interbedded gravels, also occur in the surrounding area and provide evidence of the complex glacial history of lower Strathspey since Oxygen Isotope Stage 5.

In the introduction to his previous paper on the Structure (Odell, 1939) the author included a short description of the stratigraphy of the region under review, and the briefest account only is therefore here deemed necessary.

A principal feature of north-east Greenland is the considerable number of representatives of the Geological Succession which lie exposed in the ice-free mountainous tract between the Inland Ice Cap and the Greenland Sea. These formations include Pre-Cambrian, Palæozoic, and Mesozoic sedimentaries with Kainozoic eruptives. They have a general trend north and south, and while the older rocks are situated mainly inland, the younger ones lie along the fringes of the coast-line. Consequently, as one sails westward up the immense fjords which cut transversely across the formations, one moves downwards in the succession towards the older rocks. The older rocks, however, underlie by far the greater part of the ice-free area, and of these, sandstones and coarse elastics of Old Red type, quartzites, slates, and limestones ranging from Ordovician to Pre-Cambrian, and metamorphic rocks with granites comprising a Metamorphic Complex, are found in three great belts in order from east to west, between latitudes 72° and 74°. Within these limiting latitudes, the numerous inlets and deeply entrenched fjords, whose great bare walls display in remarkable fashion the multi-coloured formations and their structures, have yielded a considerable amount of information in recent years to the British, Scandinavian, and other geologists who have studied them.