Approximately 700 samples from five slate, three marble and five quartzite units have been analysed for 26 elements to determine the use of geochemistry in stratigraphic correlation. Statistical treatment of the data has established that for all the slates and marbles, and certain of the quartzites, geochemistry is a viable method of distinguishing units of similar lithology. The most useful elements for distinguishing the four main slate units are P, Cr. Zn, Cu and, to a lesser extent, Rb, Sr, Y, Nb, Ba, La and Ce. Sr may indicate climatic changes or variable organic activity. The three marble units were considered as three limestone and three dolostone types. Dolostones are distinguished by high insoluble residue contents and the elements that distinguish between the dolostones are heavily influenced by these. Limestones, however, have very large differences in Sr. SiO2, Al2O3, K2O, Cr, Mn, Cu, Rb, Sr, Y and Zr have been used in discrimint function analysis. These parameters are strongly controlled by the insoluble residue with Al2O3, K2O, Cr and Rb being correlated with shaley impurities and SiO2, TiO2 and Zr with sandy impurities. Sr, Pb, Y and Zn, and to a lesser extent S and Mn, appear to be associated with the carbonate fraction.

The quartzites were found to be of three major types: (1) a very variable deltaic deposit (Appin Quartzite Formation), (2) marine bodies of immature quartz sands (Glen Coe and Eilde Quartzite formations) and (3) highly mature quartz sands (Binnein Quartzite Formation and northerly outcrops of the Glen Coe Quartzite Formation). It is possible to distinguish these three types on the basis of some trace elements (Zn, Rb, Sr, Y, Ba, La, Ce) but it is not feasible to distinguish between the Glen Coe and Eilde quartzites purely on geochemistry. The Eilde Flags, an immature estuarine sandstone, has a geochemistry intermediate between that of the quartzites and the pelites, although with higher CaO, Zr and Ba than either.

The study of Organic Form, which we call by Goethe's name of Morphology, is but a portion of that wider Science of Form which deals with the forms assumed by matter under all aspects and conditions, and, in a still wider sense, with Forms which are theoretically imaginable.

The study of Form may be descriptive merely, or it may become analytical. We begin by describing the shape of an object in the simple words of common speech: we end by defining it in the precise language of mathematics; and the one method tends to follow the other in strict scientific order and historical continuity.

Sixteen new species of trilobites are described and named, and thirty species are figured. The specimens were collected from a small exposure of mudstones at Craighead Quarry; most of the species are only known from this one exposure. The occurrence of several species which show strong affinities with forms from higher horizons indicates that the mudstones are more recent than other Balclatchie Group (Lower Caradocian) deposits.

Namurian alkali-dolerites in W and central Fife comprise up to nine component sills. These have three-dimensional shapes which are directly related to penecontemporaneous structures in the sedimentary host rocks. Two forms of control are identified. Basinal control is apparent where restored sill geometry shows thickening towards the bottoms of saucer-shapes which mimic sediment disposition at the time of emplacement. Fault control is evidenced by sills which change horizon along extensive E–W fractures once assumed to be entirely post-Carboniferous but now confirmed as growth-faults.

There are no associated dykes representing likely feeders comparable with those of the later tholeiitic Midland Valley Sill, but evidence is presented to suggest that at least some of the alkali-dolerite magma reached sill intrusion levels through volcanic pipes.

Contact relations and petrography of the volcanic breccia known as the Stac Fada Member, near Stoer, show that it is not a simple sediment-gravity flow, but was generated lower in the sedimentary succession by phreatomagmatic activity and rose to the surface as buoyant peperitic slurry. A previously undescribed part of the member, 9 m below the intrusive base of the main ‘flow’, has an intrusive top. Vesicle trains within the breccia matrix suggest that the slurry was boiling at a temperature of at least 160°C.

The distribution of melt has been mapped in a granite pluton deformed whilst it contained melt. At the outcrop scale, leucomonzogranite melt was segregated from hornblende monzogranite when the rigid crystal framework was tectonically compacted. The melt collected in well-defined, structurally controlled sites that formed during dextral, non-coaxial, strike-slip shearing. The segregations are generally isolated, but locally they link to form extensive branched arrays which drained larger volumes of granite in a two-step process. First, melt drained from the compacting matrix through the array and pooled along dilatant foliation planes; later, the melt moved farther away when a single planar melt-transfer channel formed.

Thin section maps show that most melt was distributed in the foliation plane and along the lineation in the crystallising matrix. The location of melt at the grain scale is primarily controlled by the feldspar-dominated shape fabric of the crystal framework, and not by tectonic stresses as at the outcrop scale. Tectonic stresses account for the relatively small proportion of melt films located in grain boundaries normal to the lineation. The distribution of melt-bearing grain boundaries outlines larger domains in the thin sections that form a linked three-dimensional network through which melt moved within the crystallising framework.

The anatomy of the soft worms variously arranged under the Nemertean Order has, even in recent times, not been carried out with that completeness necessary for their thorough elucidation, a state of matters partly due to the confounding of the structure of one family with another, and predicating of the series what investigation has but proved in one group. Few British comparative anatomists have paid much attention to these animals; indeed, Dr George Johnston, Mr Harry Goodsir and Dr Thomas Williams, are the only three who have left researches of any moment on the subject. The observations of the first-mentioned naturalist were made many years ago, with the aid of inferior instruments, and, though conscientious enough, are very meagre and unsatisfactory; and those of Dr Williams, while also showing the defects just noted, bear evident traces of imagination. Mr H. Goodsir's interpretation of structures was, from his limited observations, likewise very erroneous. On the Continent, again, the investigators have been more numerous, and a long list of distinguished names attest the interest which the subject has received at their hands.

For the opportunity of examining these specimens I am indebted to Dr W. S. Bruce, the leader of the Scottish National Antarctic Expedition, 1902–1904. I should like to take this opportunity of expressing my thanks to him, and also to Dr Marett Tims for his assistance during the preparation of the paper.

In the following pages two separate subjects are considered which are connected only by their relation to the same animals. The first concerns the feeding mechanisms and habits of the Lophogastridæ, but unfortunately no living animals could be examined.

As a result of some work on the feeding mechanisms of the Malacostraca (Cannon and Manton, 1927, in the press, etc.) it was concluded that in the Syncarida, Peracarida, and Eucarida a primary filter-feeding habit exists. This has been modified or given up entirely in the higher forms of each division in favour of feeding on larger masses of food. In the adult Hemimysis, Anaspides, and Nyctiphanes the filter-feeding mechanisms are essentially similar. The maxilla forms a combined suction pump and filter and draws a current of water through a filtering comb of setæ borne on its proximal endite. This comb is scraped by the basal part of the first trunk limb, which transfers the collected food forwards on to the proximal endite of the maxillule by which it is pushed into the mouth.

Twenty-seven species assigned to 20 genera of trilobites are described from Feilaishi in Guizhou Province, the type section of the Shihtzupu Formation in S W China. They occur in association with a sparse graptolite fauna including Glyptograptus teretiusculus. Eleven taxa are recorded here for the first time. Much new morphological information is provided regarding previously known species and 3 lectotypes are selected. The trilobites are largely endemic and indicate a quiet and comparatively shallow water environment

The country lying between the head of Loch Ainort and the northern end of the Blaven Range in central Skye forms part of a Tertiary igneous complex. Country rocks in the area are Jurassic sediments. The earliest igneous rocks are basalt lavas which show the effects of thermal metamorphism by a later intrusion of eucrite and gabbro. This latter, which is part of the Blaven mass, has features of a layered intrusion such as igneous lamination, repetition of layers rich in certain minerals and comparable textures. It may be correlated with zones of the Cuillin layered intrusion. The eucrites are cut by a cone sheet swarm. Adjacent to the eucrite is a vent breccia which contains eucrite blocks, is not cut by cone sheets and is, therefore, of later age than the eucrite. The major part of the area under discussion is formed from four granitic ring dykes and a hybrid suite with ring dyke form, all of which belong to the Western Redhills intrusive complex; in addition, part of a fifth granitic ring dyke, which probably belongs to the Eastern Redhills intrusive complex is included in the area. The granites are mainly fayalite-hedenbergite types with a variety of phenocrysts of felspar and features characteristic of high level intrusions such as granophyric texture and varying optical and chemical properties of the felspar indicating higher temperature modifications. Three new chemical analyses of the granites and one of ferrohedenbergitic pyroxene are presented. The granites may be regarded as partial remelts of the underlying basement gneiss and a simple investigation of thermal requirements indicates that the heat necessary for the partial melting could be provided by a mass of basic rock presumed from geophysical evidence to underlie the complex. Various acid and basic minor intrusions in the area are also described.

Plant fossils are a common and important element in the East Kirkton biota of Brigantian (late Viséan age). The most important taxa are preserved as compressions or anatomically preserved as permineralisations. The basis of the quantitative study of the flora and the distribution of individual plant species was the trenched section excavated for the East Kirkton Project. The largest diversity of compressions have been recorded from loose blocks. In the trenched section, the uppermost ashes contain only lycopsid compressions including Stigmaria. Nodules in the underlying shales yield mainly lycopsid leaf and sporophyll compressions. The uppermost limestones (Units 39-52) contain drifted fragments of pteridosperm fronds mainly Sphenopteridium crassum, S. pachyrrhachis, Spathulopteris obovata and Adiantites antiquus. Permineralised Lyginorachis spp. occur at this level. Large permineralised woody gymnosperm axes have been found loose (including Pitus, 50 cm in diameter). Permineralised axes, mainly reworked, including the gymnosperms Bilignea, Eristophyton, Stanwoodia and possibly Protopitys, have been found in Units 72-88. Poorly preserved permineralised lycopsids are rare, but include Lepidophloios. Loose chert blocks contain root mats of permineralised Stigmaria, together with Lepidocarpon, the sphenopsid Archaeocalamites and the fern Botryopteris. Similar material is found in Unit 83 of the Limestone sequence. Unit 82, the black shale containing many of the articulated vertebrates, contains predominantly pteridosperm frond and pinnule material including Spathulopteris obovata. The distinctive changes in the flora from the base to the top of the trenched sequence reflect mainly ecological and taphonomic controls upon plant distribution and preservation. Evidence suggests a close relationship between climate, fire, erosion, deposition and vegetation type through the sequence and a climatic change, from a drier to a wetter environment, is suggested at the top of the East Kirkton Limestone sequence.

Investigations have been made into the conditions of sedimentation of the Ordovician rocks of the Girvan district, with special attention to a series of greywackes, the Ardwell Beds, which are remarkable for frequent intraformational disturbances and unconformities.

In presenting the evidence it is proposed to follow the stratigraphical classification of Peach and Horne (1899), who, after careful consideration, adopted Lapworth's (1882) succession, except for a few minor alterations. These authors pointed out that the Llandeilo rocks north of the River Stinchar consist of Kirkland Conglomerate, Stinchar Limestone Group, and Benan Conglomerate, while south of the river they are represented by Tappins Greywackes and Glen App Conglomerate (see table p. 488).

A new occurrence of the Hirnantia brachiopod fauna is documented from the Criadero Quartzite of Almadén, Ciudad Real Province, Spain. This unit is the regional development of a largely unfossiliferous sandy facies that frequently overlies the typical Late Ordovician diamictitic glaciomarine formations in the Iberian Peninsula and the Armorican Massif. The new occurrence establishes palaeontologically the latest Ashgill age of the quartzite, at least for its lowest horizons, and adds new data on a fauna that, although widespread, has been very rarely documented from peri-Gondwanan Europe. The new collection contains only Hirnantia sagittifera and Plectothyrella crassicosta chauveli. The subspecific status of the latter and its inclusion within Plectothyrella crassicosta is discussed herein, based on the continuous variation in rib thickness of several samples of both forms. The extremely low diversity and the occurrence of the key form P. c. chauveli, are both typical of the Bani Province that developed on the subpolar margins of Gondwana. This contrasts with other occurrences of the Hirnantia Fauna in peri-Gondwanan Europe, such as those from Sardinia and the Carnic Alps, which are characteristic of the more temperate Kosov Province.

A Stem of Stenomyelon tuedianum Kidston is described with the base of a petiole of Kalymma tuediana Calder attached to it.

Two new species of Stenomyelon are described—Stenomyelon heterangioides, characterized by interspersed xylem parenchyma and mesarch protoxylem, and Stenomyelon primaevum distinguished by a solid tri-radiate protostele lacking parenchyma bands. The possible external features of Stenomyelon are compared with a compression of a Pteridosperm with large fronds.

The Foulden Site of Special Scientific Interest is one of the few Cementstone Group localities that yields significant fauna and flora. Excavations in 1980 and 1981 removed a 1·3 m2 slab of the Fish Bed for laboratory study of the vertical and spatial distribution of the biota. Layer by layer analysis revealed an almost mutually exclusive relationship between the vertical distribution of the palaeoniscoid fishes and malacostracan crustaceans, as well as a horizon crowded with juvenile acanthodians. Elongate elements of this biota showed slight preferred orientations at that prolific horizon. Some 27 m of strata including the Fish Bed, Plant Bed and Shell Bed are recorded in detail, and their biota noted. Interim results of work on the main groups collected are summarised in associated papers in this part of Transactions. Brief reports are given here on the euryhaline marine bivalve mollusc Modiolus latus (Portlock), a rare durophagous bradyodont shark tooth and an Eogyrinus-like amphibian scute.

Late Yanshanian magmatism in SE China includes three stages of thermal event induced by the interaction between the continental margin of Eurasia and the paleo-Pacific plate during the Cretaceous period. Products of syn-orogenic magmatism (130–110 Ma) include high-Al gabbros (HAG), and gneissic tonalite, trondhjemite and granodiorite (TTG), which intruded into the deep basement (18–24 km). Rocks of the post- and an-orogenic magmatism are shallow-level (6–8 km) I-type granitoids (110–99 Ma), and miarolitic A-type granites plus rhyolite-dominate bimodal volcanics (94–81 Ma), respectively. Geochemically, HAG and TTG belong to the medium-K calc-alkaline affinity with high Sr/Y, whereas other granitoids are mainly high-K calc-alkaline to shoshonitic rocks with low Sr/Y. Sr and Nd isotope compositions suggest different sources of HAG and TTG from other rocks. Progressive depletions of Ba, Sr, Eu and P from I- to A-type granites reflect partial melting of felsic granulites from hydrous to dry conditions, whereas high Sr/Y in HAG and TTG are compatible with dehydration melting of amphibolites. Tectonic models which accommodate HAG and TTG may involve thickening of the lithosphere to convert the pre-existing lower-crust basic rocks into amphibolites. It was followed by basaltic underplating which is attributed to delamination of the thickened lithosphere and led to triggering of crust melting under exten

The first four parts of this work, on the skeleton, muscles, and vascular system, were published in the Transactions of the Society in 1905, 1907, 1909, and 1912.

The present section does not include the teeth, which, belonging properly to the skin, will be described when the skin and its appendages are dealt with. It will be noticed from time to time that I have to record striking differences from results obtained by other authors. Such differences must, of course, be recorded; but in recording them it must not be understood, unless the contrary is expressly stated, that the observations under discussion are necessarily inaccurate. One cannot investigate Myxinoid anatomy without frequently coming up against somewhat astonishing variations, and I have long been convinced that there must be races or colonies of Myxine which have not been distinguished specifically, but which, nevertheless, possess anatomical features in common. To give one instance out of many. Mr R. H. Burne has described in detail an anal slime gland in Myxine.

Artificial interspecific hybrids in “diploid” species of potatoes have been recorded by Bukasov (1938), Emme (1936), Reddick (1939), and others. These authors paid little, if any, attention to the number and behaviour of the chromosomes in their plants, but rather concentrated on interspecific compatibilities, inheritance of flower colour, and resistance to disease or the genetical sequellæ to exposure to low temperature, all with regard to the possible utilisation of the plants in commerce.

The present cytological investigations are primarily concerned with the cytology of two interspecific “diploid” potato hybrids with a view to determining the homology of the chromosomes of the parents and its bearing on sterility.