The previous literature on the pre-Cambrian rocks of Ireland is considerable in amount. The views of the early workers are briefly referred to in the Handbook of the Geology of Ireland, by G. A. Cole and T. Hallissy, published in 1924. This work doubtless expresses the opinion of Irish geologists of the present day.

The solid and liquid states are defined on the basis of the viscosity-temperature curve.

Glasses are amorphous solids. Their state of molecular aggregation is fundamentally different from that of liquids: they are not super-cooled liquids.

It is suggested that porphyritic texture may result from an even rate of magmatic cooling on account of the abnormal increase in viscosity which occurs before vitrifaction.

At Hunstanton Cliff and at Snettisham there is a gradual transition, without physical break, between the Carstone and the Red Rock. At Hunstanton there is a physical break, marked by a solution-surface, between the Red Rock and the Sponge Bed. At Snettisham the Red Rock is incomplete at the top.

The Carstone shows a peculiar and characteristic assemblage of mineral constituents, with much glauconite and ferruginous ooliths. The heavy minerals are notable for the abundance of kyanite and staurolite and rarity of garnet.

The Red Rock consists of three fractions: (a) calcium carbonate, (b) red mud, (c) sand. This sand is exactly like the Carstone, with the same heavy minerals, and it continues, though in diminishing amount, up to the very top of the Red Rock.

The insoluble residue of the Sponge Bed is entirely different: it consists mainly of silicified foraminifera, with a few colourless quartz grains, and it contains no heavy minerals at all.

There is an abrupt and complete lithological change at the base of the Sponge Bed.

The red fraction of the Red Rock is rich in Fe2O3, and Al2O3, and it is suggested that it is of lateritic origin.

The precise manner of formation of the Red Rock is not explained. It has not been found possible to visualize a set of conditions under which fairly large pebbles, ferruginous sand grains, ferruginous ooliths, red mud, and calcium carbonate were all deposited at the same time.

It is suggested that the red mud is due to lateritic material derived from a neighbouring land area.

The heavy mineral assemblage shows that the material of Carstone type did not come from the north, and probably not from the west. The only possible source is the Caledonian and Armorican plateau of London-Brabant or a continuation of it under the North Sea. The sudden change at the top of the Red Rock is due to the submergence of this land area by the Cenomanian transgression, which in Norfolk was accompanied by local erosion: this finally closed the source of supply of the heavy minerals: here and there a slight recurrence of transport of lateritic material gave rise to pink bands in the Chalk at higher horizons.

The interpretation by Messrs. Kitchin and Pringle, on palaeontological grounds, of the relations of the Red Rock to the Carstone and to the Chalk is shown to be quite inconsistent with the results of this petrographical investigation.

It has been made eminently clear by Suess1 in his great synthesis of the structure and form of the planet that between those mountain systems which come into contact with one another there are very different types of structural connection. Suess' interpretations of various examples, now famous, are so well known that no repetition is here necessary, Moreover, his brilliant work has invested the subject with a surpassing interest which has led many others to give it their attention. Already the structures of the junctions between many of the world's mountain systems are understood. But the connection between two of the great mountain systems of western North America, the Coast Range of British Columbia and the Cascade Range of Washington, has been largely neglected by geologists, or misinterpreted, if not indeed completely misunderstood. Even Suess' interpretation is open to objections: it fails to separate the two ranges, and to correlate the structures of the Cascades in any way with those of the Interior Plateaux or the Rocky Mountain System.

The suite of volcanic and metamorphic rocks described in this paper were collected by the writer in the early part of 1929. With the exception of the micaceous slate (Pl. XVIII, Fig. 3), which was found in situ along the valley of the Rio Patate near Guadaloupe, all the specimens were obtained near the Cascada de Agoyan, a locality a few miles downstream from Baños along the Rio Pastaza.

—An analysis of the Loess problem is made on the basis of recent studies co-ordinating results of research along a variety of lines. Sources of confusion in the past are indicated, and the question of the delimitation of the term “loess” is discussed.

In China the Loess is essentially an aeolian deposit formed under special climatic conditions which ruled, though in different degrees, at two distinct epochs in the Pleistocene period that seem to correspond to the Günz-Mindel and Riss-Würm twin-glaciations respectively. The variations in the deposits and the relation between them, the associated fresh-water sediments, and recognizable stages in the physiographic evolution of the landscape are described. The character and implications of the fossil content are discussed, especially in their bearing on the problems of former climates and of exact correlation of geological events.

For many years the writer has been specially interested in the variations apparent in the processes of weathering of rocks under different climatic and physiographic conditions, and has made several attempts to explain such features. Of these published attempts the most detailed took the form of a Presidential Address to the Royal Society of New South Wales in 1927. Certain portions of the argument were repeated in Economic Geology, but the regional aspects of the question were omitted.

As is well known, the chronological order of deposition of the sediments of that broad band of schists which extends across Scotland from Banffshire and Aberdeenshire in the north-east to Argyllshire in the south-west is a most difficult problem to determine. The noteworthy development that has been made during recent years, leading to a more intimate understanding of the structure of the Southern Highlands, has made this problem much more vital. The question as to the top and bottom of these beds has been much discussed in recent years, and it can not be denied that views have been widely divergent on this matter. When a foreign geologist desires to call attention (through this paper) to certain conditions of fact, it may be pointed out that he is carrying on similar studies of another section—the Norwegian—of this same mountain chain, where one meets similar problems as in the Scottish Highlands.

The area studied includes the majority of the main granite masses north of the belt of Ordovician and Silurian rocks running eastwards from Quimper to around Vitré and Laval. The heavy minerals of the Channel Islands granites have already been described by the writer (1). In the present paper the work is extended to the northern half of Finistère, and the greater part of the Côtes-du-Nord, Ille-et-Vilaine, and Manche. It is confined for the most part to the granites, and comparisons are made with those of the Channel Islands in an endeavour to obtain more definite evidence as to the age of the Jersey “Newer” Granites.

In 1928 the Trustees of the British Museum purchased for the Geological Department the skeleton of a large Ichthyosaur then being prepared in the workshop of Dr. B. Hauff in Holzmaden. During its preparation the skeleton was, with the permission of the Department, studied by Professor F. von Huene, of Tübingen, who subsequently published and adequate description and figure of it, and who reached the conclusion that it was probably a new species. Since I consider that the specimen is undoubtedly different from the others so far described as Eurhinosaurus longirostris I propose here to review briefly its main characteristics under a new specific name. As von Huene has done the most important work on the genus it is with great pleasure that I name this new species in his honour.

In view of the probability that there is likely to be some little delay in publishing the official Memoir on the Bufumbira volcanic rocks, which is in course of preparation by Mr. A. D. Combe and the writer, with, we hope, collaboration with authorities in England, permission has been given to publish a short summary of the results so far obtained in the investigation of these rocks. Mr. Combe has made a careful geological survey of the ground and has separated on his map forty-nine flows from nearly forty different centres situated at the south-west corner of the Uganda Protectorate. The remainder of this large volcanic field lies in the Belgian Congo to the west and south, and though all of those volcanoes, several of which are still active, have been visited by geologists and specimens of the rocks obtained, no very detailed field-work has been published on them, either by us or any other observers up to the present time; so far as is known to the writer.

Syrabia, to use Krenkel's comprehensive term for the great region comprising Arabia, Syria, Palestine, and Sinai, has been the theatre of vast igneous activity from the Cretaceous to the present time. M. Blanckenhorn divides the igneous rocks of this region into two groups, according to age, as Cretaceous-Eocene and Neogene-Quaternary. The Cretaceous-Eocene group includes gabbro-serpentine-diabase intrusives and extrusives involved with, and restricted to, the Eurasian fold-mountain system in the northern part of the region, and also prevailingly basaltic eruptives occurring in the Syrabian plateau country.

The Farsan Islands form a group in the southern part of the Red Sea, about 17° N. Lat., 42° E. Long., and lie some 40 km. off the Asir Coast of south-west Arabia. The two main islands are Farsan Kebir (whose north-western arm is known as Seïr), and Segíd, which nestle together with a length of 60 km. and breadth of roughly 25 km. There are five smaller islands varying in length from 5 to 13 km., and a host of minor islets and rocks. The islands are in general of rather low elevation, not rising to more than 10 to 20 metres above sea-level. Local hills occur up to 75 metres, and are mostly due to faulting, occasionally to folding.

Two papers bearing the same title have recently appeared in this magazine on the geology of Mangaia and Rurutu, two small islands located in the western part of the South Pacific Ocean.

In the first place let us deal with the origin of the word. It was first used in 1807 by F. Buchanan in A Journey from Madras through Mysore, Canara, and Malabar. In dealing with the iron-ore seen during his journey he wrote:—“In all the hills of the country the ore is found forming beds, veins, or detached masses in the stratum of indurated clay, that is to be afterwards described, and of which the greater part of the hills of Malabar consists. … What I have called indurated clay … is one of the most valuable materials for building. It is diffused in immense masses, without any appearance of stratification, and is placed over the granite which forms the basis of Malayala. It is full of cavities and pores, and contains a very large quantity of iron in the form of red and yellow ochres. In the mass, while excluded from the air, it is so soft, that any iron instrument readily cuts it, and is dug up in square masses with a pickaxe, and immediately cut into the shape wanted with a trowel, or large knife. It very soon after becomes as hard as a brick, and resists the air and water much better than any bricks I have seen in India. … As it is usually cut into the form of bricks for building, in several of the native dialects it is called the brick stone. … The most proper English name would be Laterite, from Lateritis, the appellation that may be given to it in science.”

The genus Dimorphoceras was instituted by Hyatt, the genotype being Goniatites gilbertsoni (Phillips). The shells are involute and compressed, having the umbilicus very small or closed. The test shows fine lines of growth and a deep hyponomic sinus. Dimorphoceras is differentiated from other goniatites by having either one or both of the sutural lobes sub-divided by a small subsidiary saddle. Specimens are not generally abundant; and owing to the feeble ornamentation of the test, distinction between species is impossible unless uncrushed specimens showing sutures are obtained.

At 10.17 a.m. on the 17th June a severe earthquake shook Wellington and dislodged the mirrors of the Milne-Shaw seismographs at the Dominion Observatory. As soon as the instruments were readjusted, the after-shocks indicated the epicentre was in the northern part of the South Island; and telegrams from all parts of the Dominion showed that Murchison village had suffered more damage than any other locality. Accordingly a number of Government Officers from several technical departments visited those areas where great damage was reported and on their return to Wellington a round-table conference was held on 26th June, in the room of the Hon. The Minister for Scientific and Industrial Research. In addition to investigations that would normally follow the earthquake, several other pieces of work were suggested at the conference or were subsequently undertaken.

Three small simple corals were collected by Mr. F. P. Mennell from the Upper Cretaceous of the Cheringoma district, Portuguese East Africa. The area is of special geological interest as it includes the southern end of the Great Rift Valley and furnishes useful evidence as to the date of the formation of that valley. A coral from almost the same horizon has been figured by Schlosser, and, as it is clearly a different species, the horizon may be expected to yield a good fauna of simple corals.

The material which is described in this note was collected by members of the Geological Staff of the Anglo-Persian Oil Company, Ltd.

It is unusual to discover specimens of Palaeozoic Brachiopoda which clearly display the characters of the delthyrium; in particular, very little is known concerning these features in Carboniferous Protremata. The writer has therefore been fortunate in obtaining well-preserved examples of Chonetes, in which the ventral pseudodeltidium and the dorsal cardinal process are exhibited in detail. It has also been found possible to determine the internal features of these structures by means of serial sections.