In the Scottish Lower Carboniferous limestones there are known to occur at least sevenspecies of Dicyclic Inadunate crinoids belonging to the family Poteriocrinidae, one of the main characters of which is the possession of five simple unbranched arms. One species is also known from the Carboniferous of the Isle of Man. Two of the Scottish species have been assigned to the genus Ulocrinus, viz. U. globularis de Koninck and U. doliolus Wright. The former species is now referred to U. bockschii (Geinitz), which has priority, and the Scottish specimens as they commonly occur appear to be indistinguishable from it. The cup in these two species is specially characteristic, the shape being for the most part globular and the anal area, while sometimes of normal character, is more commonly occupied by a large RA with anal X and rt surmounting it and comparatively small. The arms are rather long, uniserial, and formed of narrow cuneiform brachials (Plate XIV, Figs. 1–6). (Bather, 1916–17; Wright, 1927, 1936.)

The progress of modern discovery, both in Palæontology and Zoology, has been steadily tending to bridge over the gap which seemed at one time to separate the past from the present life-history of our globe, and has brought each more closely into relationship with the other than seemed possible fifty years ago.

An occurrence of kyanite pseudomorphing andalusite, from the Urungwe District of Southern Rhodesia, is described. The pseudomorphs, which include some of the largest of their kind so far recorded, occur in profusion in certain Pre-Cambrian pelitic schists. The original andalusite was completely converted to kyanite during regional metamorphism but the shape of the original crystals was perfectly preserved. This, together with the habit of the kyanite within the pseudomorphs, shows that the change took place under conditions of insignificant shearing stress.

Mudstone inclusions in graded greywacke-conglomerates of Salopian age from the Slieve Bernagh Mountains, Co. Clare, are considered to have been formed by fracture of the conglomerates in the course of slumping shortly after deposition and the infilling of the resulting cavities by mud derived from the underlying beds. The attitudes of the inclusions and of associated pebble imbrication suggests that slumping took place on a slope with a northerly inclination of 10°.

Extensive magmatism in NE China, eastern Central Asian Orogenic Belt, has produced multi-stage granitic plutons and accompanying W mineralization. The Narenwula complex in the southwestern Great Xing’an Range provides important insights into the petrogenesis, geodynamic processes and relationship with W mineralization. The complex comprises granodiorites, monzogranites and granite porphyry. Mafic microgranular enclaves are common in the granodiorites, and have similar zircon U–Pb ages as their host rocks (258.5–253.9 Ma), whereas the W-bearing granitoids yield emplacement ages of 149.8–148.1 Ma. Permian granodiorites are I-type granites that are enriched in large-ion lithophile elements and light rare earth elements, and depleted in high field strength elements and heavy rare earth elements. Both the mafic microgranular enclaves and granodiorites have nearly identical zircon Hf isotopic compositions. The results suggest that the mafic microgranular enclaves and granodiorites formed by the mixing of mafic and felsic magmas. W-bearing granitoids are highly fractionated A-type granites, enriched in Rb, Th, U and Pb, and depleted in Ba, Sr, P, Ti and Eu. They have higher W concentrations and Rb/Sr ratios, and lower Nb/Ta, Zr/Hf and K/Rb ratios than the W-barren granodiorites. These data and negative ϵHf(t) values (–6.0 to –2.1) suggest that they were derived from the partial melting of ancient lower crust and subsequently underwent extreme fractional crystallization. Based on the regional geology, we propose that the granodiorites were generated in a volcanic arc setting related to the subduction of the Palaeo-Asian Ocean, whereas the W-bearing granitoids and associated deposits formed in a post-orogenic extensional setting controlled by the Mongol–Okhotsk Ocean and Palaeo-Pacific Ocean tectonic regimes.

The peculiar tectonic structure called “boudinage” by Lohest (5, pp. 471–2), has recently been found in Unst, Shetland Islands, by Professor H. H. Read (8, pp. 134–8), who has also noted its occurrence in tie Durn Hill quartzites of Banffshire (9, p. 471).What would now be termed boudinage-structure was seen by Ramsay in North Wales, and was described in 1866 in these words (6, and. fig. 18): “In the great quarry west of the Ffestiniog and Trawsfynydd fault the cleavage dips from 45° to 50° north-west, the inclination of the beds being about 35° in the same direction, and a greenstone dyke runs through them between the cleavage-planes…, bulging and thinning off in a rapid succession of oval-shaped masses of 3 or 4 feet in length. Associated with it are quartz veins ccurring principally at the points between the separate bulgings of the greenstone.”

The Upper Famennian (Upper Devonian) Strud locality has yielded very abundant and diversified flora as well as vertebrate and arthropod faunas. The arthropod fauna, mostly recovered from fine shales deposited in a calm, confined floodplain habitat including temporary pools, has delivered a putative insect and various crustaceans including eumalacostracans and notostracan, spinicaudatan and anostracan branchiopods. Here we present the Strud eurypterids, consisting of semi-articulated juvenile specimens assigned to Hardieopteridae recovered from the pool and floodplain deposits, as well as larger isolated fragments of potential adults recovered from stratigraphically lower, coarser dark sandy layers indicative of a higher-energy fluvial environment. The Strud fossils strongly suggest that, as proposed for some Carboniferous eurypterids, juvenile freshwater eurypterids inhabited sheltered nursery pools and migrated to higher-energy river systems as they matured.

Mafic–ultramafic Quaternary lava flows form the Tigris volcanic field (covering 1750 km2) at the northeastern tip of Syria and extend into Turkey. This volcanic field occurs between the Euphrates graben and the Bitlis–Zagros collision suture that forms the boundary between the Arabian and Eurasian plates. The rocks are made up of labradorite, clinopyroxene, olivine and opaque phases. The Tigris lavas are compositionally restricted to basanites and alkali basalts, having a narrow range of major element compositions (SiO2, 42.2–48.2 wt%; MgO, 5.7–9.0 wt%, with Mg numbers ranging from 0.51 to 0.62; TiO2, 1.7–3.2 wt%), and are alkaline in nature. The rocks are enriched in HFS elements such as Zr (119–231 ppm), Nb (14–43 ppm) and Y (17–22 ppm). The REE patterns are strongly fractionated ((La/Yb)N = 10.6), indicative of a garnet-bearing source. The 143Nd/144Nd isotopic compositions range from 0.512803 to 0.512908, and 87Sr/86Sr from 0.70327 to 0.70403 (εNd = 3.2–5.3) suggesting strong affinities to ocean island basalts. Modelling using a variety of mantle source materials and different degrees of partial melting indicates that the magma was produced by a small degree of batch partial melting (F = 1.5%) of a primitive, garnet-lherzolite fertile mantle source. The overall petrological/chemical nature supports this interpretation. Shear heating at the base of the lithospheric mantle of the northern boundary of the Arabian plate, caused by a change in plate motion as the Arabian plate moved in a more easterly direction during the Plio-Quaternary, could represent a possible source of the heat necessary for partial fusion and magma generation. Adiabatic decompression and melting represents a more likely process for the generation of the Tigris magma. Elemental ratios such as K/P (4.6), La/Ta (12), La/Nb (0.90), Nb/Y (1.22) and Th/Nb (0.09) indicate that the magma was subjected to minimal crustal contamination.

More than twenty years ago, whilst engaged in the study of the Lower Carboniferous rocks of Westmorland, I noticed the occurrence of certain small concretionary nodules of very compact texture in the dolomites near the base of the succession in the neighbourhood of Shap.

The “Tarskavaig-Moine” schists occupy a small area in the Sleat district of Skye, extending southwards from Tarskavaig to the Point of Sleat, a distance of about seven miles, with a maximum width of outcrop of two and a half miles between the coast on the west and structurally overlying formations on the east. Their tectonic relationships and petrographic characters were first described in detail by C. T. Clough in the Geological Survey Memoir on the North-West Highlands of Scotland (1, pp. 589–594, and pp. 618–621). The northern part of the outcrop falls in Sheet 71 of the one-inch geological maps, and is described in the accompanying memoir (2); the southern part falls in the unpublished Sheet 61. Later publications summarize these earlier discussions (3, p. 171; 4, p. 309; 5, p. 23); the last named includes a map of the whole outcrop, on a scale of two miles to an inch, simplified from manuscript maps by Clough. A summary of the tectonics and metamorphism has recently been published by Dr. E. B. Bailey (6).

The incommodus, atavus and cyphus monograptid groups appear more or less simultaneously in the atavus Zone. The atavus and cyphus groups are related, one of these probably giving rise to the later tenuis group of monograptids, Possible roots of these groups and relationships with later monograptids are discussed. Monograptus strachani sp. nov. is proposed to replace the name M. incommodus sensu Elles & Wood.

The material upon which the following descriptions are based was obtained chiefly by Mr. Ussher, who collected the Whiteway and Hestow Farm specimens. The Daymer Bay form was collected by Mr. John Pringle. For the new species of Proetus I am indebted to Mr. Claude H. Peter, Town Clerk, Launceston, who, through Mr. Clement Reid, kindly lent it for description. It is evident from the examination of this limited quantity of material that the British Devonian fauna is not yet fully known. We may expect the discovery of many species hitherto unrecorded in this country, which will be of interest from the possible comparative relationship with the fauna of foreign deposits. The accompanying illustrations were drawn by my colleague, Mr. H. H. Thomas, to whom I tender my best thanks.

It was indicated in a previous paper (Geol. Mag., LXXII, 1935, p. 208) that the Scottish Lower Carboniferous crinoid fauna contains a number of species which have never been adequately described. In the present communication, ten of these are discussed, the remainder, another ten or eleven species, will be dealt with later. All the specimens except four were collected by myself many years ago, but it was only recently that the requisite leisure was found to develop and clean them thoroughly.

—The field impression of a high degree of uniformity in the composition of the intrusive Karroo dolerites over a vast area is confirmed by new chemical and microscopical studies. The pyroxene characteristic of the dolerites is a typical pigeonite, which, however, does not display any twinning on (100). The plagioclase is potash-free, usually a labradorite, but it has been observed that a homogeneous crystal of plagioclase may be in twin position to another homogeneous crystal of a very differently composed plagioclase. The close resemblance of the doleritic liquid to the artificial liquid taken by Bowen to represent basaltic liquid is noted, and his conclusion that pyroxene and feldspar should crystallize simultaneously in natural basaltic liquid is confirmed.

Conceivably the doleritic liquid was quite original and not a differentiate of any earlier liquid. However, analogies like those with the tholeiites and similar hypabyssal rocks of Great Britain suggest that in South Africa, as in Great Britain, the liquids of these hypabyssal rocks were derived from the slightly more femic plateau-basalt.

On that assumption the question of the mode of differentiation arises. The fractional crystallization of plateau-basalt, as now described by Bowen and other leaders, does not appear competent to explain the abnormally low soda of one of the analyzed dolerites, nor the excess of soda and total alkalies in plateau-basalt respectively over the soda and total alkalies of the Karroo dolerite. Further, the settling-out of early olivine does not explain the excess of (total) FeO in plateau-basalt over the (total) FeO in the Karroo dolerite. The actual relations indicate the need of renewed examination of the theory of magmatic differentiation by crystal-fractionation. In any case many more data are required before it is possible to decide upon the precise relation of the Karroo dolerite to a parental magma. Possibly such additions to knowledge may annul present difficulties in the way of accounting for the composition of the dolerite.

The Kraemer Island macrodyke that is exclusively exposed on Kraemer Island about 7 km west of the Skaergaard Intrusion belongs to a regional dyke swarm termed the ‘Skaergaard-like dykes’ (or FG-1 dykes). Weakly modally layered olivine gabbros dominate the exposed parts of the intrusion that has a width of 650 m to 1000 m. Plagioclase (core An68±2) and Ca-rich pyroxene (core Mg no. 79±1) grains are normally zoned, whereas olivine grains (Fo50–65) are homogeneous. Calculated mineral–magma equilibria, based on experimentally determined Mg–Fe magma–olivine and magma–clinopyroxene partition coefficients, suggest that the observed olivine and clinopyroxene compositions in the gabbros cannot have formed from a common parental magma. The unzoned nature of olivine grains and their iron-rich com-positions relative to clinopyroxene suggest post-cumulus Mg–Fe exchange between olivine and interstitial melt. A gabbroic pegmatite is developed in the centre of the intrusion along its entire exposed 5 km strike length. Here, mineral zonation is limited and compositions are similar to rims of cumulus minerals in the enveloping olivine gabbros. The pegmatite could therefore represent interstitial melt mobilized from gabbroic cumulates that later accumulated and crystallized at its present stratigraphic location. Cumulus olivines in the gabbros are close to equilibrium with Ca-rich pyroxene in the pegmatite. This is interpreted as reflecting interstitial melt mobility during the late stages of solidification of the macrodyke. Chilled margins are well preserved at the intrusion margins and are rich in Fe (14–15.3% FeOTOT), Ti (3–3.3% TiO2) and light rare-earth elements ([La/Sm]N = 1.2–1.3), similar to magmas well represented in the overlying sequence of contemporaneous High-Ti Series flood basalts. It is therefore likely that extensive wall-rock melting adjacent to the macrodyke reflects continuous feeding of the overlying flood basalts through the Kraemer Island macrodyke.

A new dinosaurian track-bearing site, with tridactyl footprints from the Lower Jurassic (pre-middle Pliensbachian) volcanogenic and epiclastic rocks of the Marifil Volcanic Complex, Patagonia, Argentina, is presented and described. The best-preserved footprint, classified as cf. Anomoepus, confirms the utility of the Anomoepus-like tracks for the Early Jurassic biochronology. Palaeobiogeographically, this record supports the idea that the South American Early Jurassic dinosaur fauna presents elements of Pangaean distribution, and others with Gondwanan relationships with prevalent southern African affinities. Dinosaur records from South America between the Rhaetian and the Pliensbachian are very scarce, and this find contributes to the knowledge of early radiation and evolution of Dinosauria.

Of the rich collections of fossils made by Professors J. W. Gregory and E. J. Garwood, as members of Sir Martin Conway's expedition to Spitsbergen in 1896, only a few Labyrinthodont remains, so far, have been described; but through the kind offices of Dr. A. Smith Woodward, the writer some time ago was entrusted with the naming of the Cephalopoda in those collections. The Ammonites are of the greatest interest, both from a palæontological and a stratigraphical point of view; and in view of the impossibility of publishing, in the near future, a full description of the fauna, with the necessary number of plates, it is intended to give a short preliminary account of these Cephalopoda. It is matter for regret that other groups of invertebrate fossils, such as the Triassic Pelecypoda, or the Upper Jurassic Aucellids, could not be dealt with, and their detailed study, probably, would yield important results. Spitsbergen Vertebrata, on the other hand, always have received considerable attention.

The Oramutia volcanics consist of a group of ignimbrites overlain by pumice tuffs, which lie in a fault formed valley on the eastern flank of the main Kenya rift valley. The presence of a dyke of ignimbrite suggests that the “claystone ” ignimbrite of this area was erupted from fissures. A similar explanation probably applies to the pumice tuffs. These volcanics are therefore the product of Katmaian type eruptions.