bluuebunny/crossref_metadata_2025 huggingface dataset:
On Certain Palaeozoic Bryozoa in the British Museum (Natural History)
Authors: Nekhoroshev B. P.
Published: May 2009

While working for several years on Palaeozoic Bryozoa with the aim of establishing the Palaeozoic stratigraphy of the Altai Mountains on the basis of the Bryozoan faunas, I have always been aware of a great contradiction. The works of American authors showed clearly that the stratigraphic importance of the Bryozoa is not inferior to that of any other group of fossils, whilst in the works of newer European authors the Palaeozoic Bryozoa were not only deprived of any significant rôle, but often even quite ignored. Owing to this, there arose a question whether the Palaeozoic Bryozoa have a universal distribution like, for instance, the Brachiopoda; or whether there is in North America a special Bryozoan fauna of stratigraphic importance locally, but absent from other parts of the globe. The study of the Siberian Palaeozoic Bryozoa showed a number of forms so far known only from North America, and this suggested that the apparent absence of “American” forms in the other parts of the globe is owing to the lack of intensive study given to the Palaeozoic Bryozoan faunas outside North America. Through the kindness of Dr. Nalivkin, who handed over to me several Bryozoa collected by him in the Middle Devonian of Germany, I was able to confirm this suggestion and I decided to examine, if possible, the existing collections of Palaeozoic Bryozoa of Europe. This appeared the more necessary because, although Palaeozoic Bryozoa were originally described by European authors, yet the species described by them were quite ignored by later American writers. Clearly then, if a comparison of the European with the American Palaeozoic Bryozoa were made, it would be likely that the trivial names of some American species would be replaced by the prior trivial names of European species. To make this comparison, I visited during the winter of 1928–1929 some of the most important museums of Europe, in which I could find either the type specimens of the European Bryozoa, or merely rich collections of topotypes. A revision of the material contained in the museums of Berlin, Munich, Bonn, Prague, Paris and London wholly confirmed my view, namely, that the “American” forms of Palaeozoic Bryozoa were universally distributed, but hitherto had been described and figured, often quite incorrectly, as distinct genera.
The Igneous Rock at Hestercombe, Somerset
Authors: Evens E. D. , Wallis F. S.
Published: May 2009

The object of this investigation was to examine the well-known Hestercombe “syenite” in greater detail than had been done before, to attempt to trace its extent, and if possible, to determine its age.
On a New Species of Eurhinosaurus in the British Museum
Authors: Swinton W. E.
Published: May 2009

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.
The Upper and Lower Junctions of the Midford Sands at Limpley Stoke, S.E. of Bath
Authors: Gorham A.
Published: May 2009

Before describing the section at Limpley Stoke I wish to acknowledge the very kind help given to me by Dr. W. D. Lang, F.R.S., Keeper of the Department of Geology in the British Museum (Natural History), who has had the fossils examined and through whose encouragement I am recording the results of an investigation extending over a considerable time.
The Geology of the Farsan Islands, Gizan and Kamaran Island, Red Sea
Authors: Macfadyen W. A.
Published: May 2009

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.
Igneous and Associated Rocks from the Andes of Eastern Ecuador
Authors: Sheppard George
Published: May 2009

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.
The Petrography of the Hunstanton Red Rock
Authors: Rastall R. H.
Published: May 2009

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.
On the Geological Evolution of the Chesil Bank
Authors: Baden-Powell D.
Published: May 2009

The Quaternary System has always presented peculiar difficulties to those geologists who have attempted to work out its chronology, largely owing to the fact that it is not always easy to correlate the details of one locality with those of another. In some cases at least, this appears to be due to lack of knowledge of the detailed sequence of events within a limited district, whether such a sequence is considered from the climatic or from the cultural point of view, or from a combination of both. The main object of the present paper is to enquire into the state of our knowledge concerning the Quaternary and Recent train of events which have taken place within a limited district, so that in the future this area can be compared with others which will have been treated in a similar way.
Sedgwick Museum Notes: The Contacts of the Threlkeld Microgranite
Authors: Richardson C. , Caldwell E.
Published: May 2009

During an expedition to the Lake District, led by Miss Elles, the contact of the Threlkeld microgranite with the rocks into which it has been intruded was examined. The lower contact of the microgranite with the Skiddaw Slates is now well exposed at the eastern end of the main quarry south of Threlkeld railway station; and also in the light-railway cutting connecting this quarry with the newer quarries to the S.W. This contact is transgressive to the bedding of the slates, and at the first-named exposure the two rocks are dove-tailed into each other. The slate can be seen to be but slightly hardened and so little alteration has been effected that well-preserved graptolites were found within 18 inches of the contact.
On the Structure and Mode of Occurrence of Scolithus linearis (Haldeman) in the Cambrian Quartzites of the North-West Highlands
Authors: Macnair Peter , Reid D. M.
Published: May 2009

It is some thirty years ago and about ten years after the mapping of this area by the officers of the Geological Survey that one of the present writers ascended Quinaig at Inchnadamph and saw for the first time the so-called “Pipe-rock” which caps the summit of that mountain. Here one can walk over the exposed surfaces of the quartzite and it is impossible not to observe the curiously spotted or pitted surfaces of the white slabs which, in many places, look like nothing so much as the soles of a labourer's shoe covered with projecting hobnails (see Plate IV, Fig. 1).
Rock Crystal and Diamond Pipes in Brazil
Authors: Walls Robert R.
Published: May 2009

It is now eight years since the present writer drew attention in these pages to his discovery of a diamond-bearing pipe of igneous origin in Brazil (3). The matter, though hotly contested and denied at the time, seems now to have been generally accepted. So much so in fact that Dr. Alex. du Toit, in his presidential address to the Geological Society of South Africa (10) compares the diamond-bearing pipes of Brazil and South Africa as an indication of the former close connection of these lands.
The Classification of a Glassy Rock: The Pitchstone of Wormit, Fifeshire
Authors: Shand S. J.
Published: May 2009

In most systems of petrography the glassy rocks are treated in a very casual way. The names which are commonly given to them, such as obsidian, pitchstone, perlite, vitrophyre, and the like, afford no reliable indication of composition; and when a rock is partly crystalline and partly glassy, the composition of the glass is often assumed, quite unwarrantably, to be the same as that of the crystals. It is only in the Norm classification that vitreous rocks fall unfailingly into the same compartments as holocrystalline ones of similar chemical composition; and before any rock can be classified by this method, it is necessary to have a complete chemical analysis of it; which is, for many workers, a serious obstacle.
Notes on Some Early British Graptolites
Authors: Stubblefield C. J.
Published: May 2009

Fifty years ago Charles Callaway collected some graptolites from the Shineton (Tremadocian) Shales exposed in Mary Dingle (south of the Wrekin, Shropshire); these he recorded as Dendrograptus sp., stating that he was unprepared to assign them “to any known species or to give them a new name”. The fossils were sent to Charles Lapworth who in 1879 (loc. cit.) wrote that they belonged to two different genera, Clonograptus and Bryograptus; the Clonograptus he later identified (loc. cit.) with reserve as C. rigidus Hall, whilst the Bryograptus formed a genosyntype for that then new genus. Bryograptus was defined by Lapworth about this time from two new species—(1) B. callavei, collected by Callaway from the Shineton Shales, and (2) B. kjerulfi, of which Lapworth had only seen the figures (Graptolithus tenuis) which Kjerulf had drawn from specimens found in the Alum Shales of Vaekkerö (near Oslo).
Pleistocene and Recent Basalts of Transjordania and Palestine
Authors: Tyrrell G. W.
Published: May 2009

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.
On the Classification of Faults
Authors: Earle Kenneth W.
Published: May 2009

The experience of several years' teaching in the interpretation of geological maps has convinced the writer of the need for some more satisfactory method of classifying faults than has hitherto obtained.
Quartzose Conglomerate at Caldon Low, Staffordshire
Authors: Barke F. , Hind Wheelton , Scott A.
Published: May 2009

IN the Geological Magazine for February, 1919, J. W. Jackson and W. E. Alkins described the occurrence of a quartzose conglomerate at Caldon Low, Staffordshire. In August one of us (F. B.) pointed out some previous references to this outcrop. The curious and ambiguous reply by Messrs. Jackson and Alkins
On an Inverted Mass of Upper Cretaceous Strata near Leighton Buzzard, Bedfordshire; and on an Overlap of the Upper Gault in that Neighbourhood
Authors: Kitchin F. L. , Pringle J.
Published: May 2009

Summary of Conclusions.

We may summarize our chief conclusions as follows:—

(1) The brachiopod-bed of Shenley Hill, as described by Messrs. Lamplugh & Walker, who referred it to the Lower Greensand, is shown by stratigraphical and palæontological evidence to be of a composite character. Its constituent parts belong respectively to the basement-bed of the Upper Gault and to the basement-bed of the Cenomanian stage, as understood by English geologists (sub-zone of Catopygus columbarius).

(2) The Cenomanian bed is present in the form of isolated lenticles of limestone. Although no comparable stratum can be found at the present outcrop, which has receded from the area where conditions produced this particular type of deposit, the bed has a close lithological counterpart in Northern France (Matringhem), where there is an almost identical bed at the base of the varians zone.

(3) At Harris's Pit the Cenomanian bed, an inconstant layer of Upper Greensand formerly seen above it, and an overlying mass of Gault Clay of rostratus age are in an inverted order of succession. There is a junction of erosion and non-sequence between the Gault and the Cenomanian bed.
The Pre-Glacial Valleys of Arran and Snowdon
Authors: Gregory J. W.
Published: May 2009

THE history of the British Isles in the Pliocene has an important bearing on their glacial geology and on the origin of their existing geographical features. Physiographic evidence indicates that the Lower Pliocene was in Britain an epoch of depression, during which the sea covered parts of South-Eastern England, whereas the Middle and Upper Pliocene were marked by an uplift which excluded the sea from the British Isles, except in East Anglia and Western Cornwall. It is generally agreed that this uplift raised the low-lying plains that had been formed during the Lower Pliocene into plateaus from 500 to 1,400 feet above sea-level. The uplift lasted through a long period of time; and such a slowly rising land would naturally be greatly denuded by rivers. Plateaus and platforms due to the Pliocene uplift have been described by Dr. Mort for Arran and by Professor W. M. Davis for Snowdon; yet in their discussion of the present topography of those districts they attribute a very slight influence to stream erosion during the long pre-Glacial elevation.
A Recent Worldwide Sinking of Ocean-level
Authors: Daly Reginald A.
Published: May 2009

LOCAL uplift and local sinking of the earth's surface have been fully demonstrated for past geological epochs. The amounts of these movements have generally been stated with reference to the present sea-level, and for the greater movements the statements of magnitudes are not seriously impaired by the fact that general sea-level itself has been shifting, upwards and downwards, through geological time. Among the causes for general or “eustatic” shifts of sea-level are: appropriate crustal movements whereby the volume of the ocean basin has been changed; delta-building and volcanic eruption on the sea-floor, the displacement of sea-water not being compensated by crustal sinking; volcanic addition of new water to the ocean; subtraction of water which becomes chemically bound during the alteration of rocks; glaciation on land, lowering sea-level by the abstraction of water from the ocean; deglaciation on land, raising sea-level; changes in the earth's centre of gravity and in her speed of rotation.
Isostatic Measure of the Rocky Mountains
Authors: Keyes Charles
Published: May 2009

Among the enisled high plateaux of Eastern Utah the brilliant isostasy theory had its birth. When these arid mountains first became the subject of special description, about 1880, no such thing as a distinctive desert geology was entertained. Possibility of a definite geographic cycle in land sculpture was one of the modern earth conceptions yet undreamed. Competency of the wind as a general erosive agency was not yet established. Operation of epeirogenic movements was little understood. Omission of such basic considerations necessarily led to curious aberration in interpretation of the phenomena presented by lands of little rain.
Differentiation and Ore-deposits
Authors: Rastall R. H.
Published: May 2009

AT the present time most mining geologists appear to be in general agreement on the principle that primary ore-deposits are derived from igneous magmas. Furthermore, it is now almost universally recognized that the segregation and concentration of the metals and their compounds into payable ore-deposits is but part of a larger and more fundamental problem, namely, the differentiation of the igneous rocks, a problem which has exercised the ingenuity of petrologists for many years past and is still by no means solved. Unfortunately most of the speculations and theories put forward in explanation of these phenomena are in the main founded on facts and inferences derived from the study of the silicates; comparatively few petrologists have taken into account the behaviour of the oxidic and sulphidic compounds of the useful metals, which are commonly regarded in the light of rare and accidental constituents of the magma, rather than as having any particular bearing on the point at issue. The most notable exception to this general statement is Vogt, whose work on slags and ore-deposits is of an epoch-making character from the theoretical point of view, as well as of immense practical importance in smelting and blast-furnace practice. However, within the last few years great attention has been devoted by mining geologists to the subject of the genesis of ore-deposits, mainly because of its bearing on the question of persistence in depth or the replacement at lower levels of one ore by another, such as is known to occur in certain cases. It may be suggested, therefore, that the time has now come when it may be possible to attempt to combine the facts hitherto discovered along different lines of research into a coherent whole.
Isostatic Tendencies as the Origin of all Geodynamic Phenomena
Authors: Sandberg C. G. S.
Published: May 2009

C. E. Dutton, in his paper on some of the greater problems of physical Geology (Bull. Phil. Soc. Washington, vol. xi, pp. 51–64, 1889–91), formulated his conception of Isostasy in the following words: “For this condition of equilibrium of figure to which gravitation tends to reduce a planetary body, irrespective of whether it be homogeneous or not, I propose the name of Isostasy. Isostasy is being disturbed by denudation and sedimentation …”
The Pliocene Age of the Brain Valley Gravels, Essex
Authors: Gregory J. W.
Published: May 2009

The fragment of silicified tree stem identified in the preceding paper by Mr. W. N. Edwards as a Dadoxylon from the Upper Carboniferous of Warwickshire was found in the gravel pit at Tiptree Heath just west of the King's Arms. This pit is at 269 feet above sea-level on the summit of the ridge that runs from Wickham Bishop, towards Colchester. The gravel is part of an extensive sheet which is shown on the Geological Survey Map (sheet 47) as Glacial Gravel. Dr. A. E. Salter (Proc. Geol. Soc., xix. 1905, p. 31) recorded from this pit Bunter debris, sarsens, radiolarian chert, rhyolite, and the green ash associated with it, and Carboniferous chert, with crinoids.
On the Deposition of Calcareous Tufa in a Mountain Stream at Binn, Canton Valais, Switzerland
Authors: Macfadyen W. A.
Published: May 2009

Aggradation of the bed of a river is a well-known and common phenomenon in certain circumstances, but in the present case a mountain stream, whose grade is to steep that waterfall are present, is found flowing along the top of a well-marked but very irregular ridge to tufa. This is found in a little stream near the village of Binn, known to mineralogists for the rare minerals which occur in metamorphosed Triassic dolomite not far away up the valley of the Binna.
Some Observations on the Geology of Viti Levu
Authors: Matley C. A. , Davies A. Morley
Published: May 2009

In the course of a voyage across the Pacific in September, 1924, from Vancouver to New Zealand, I broke my journey at Suva for four weeks with the object of seeing something of the geology and scenery of Viti Levu. Half that time, however, was spent in a cruise to the Tonga Islands and Samoa, leaving therefore only a fortnight for Viti Levu, but His Excellency the Acting Governor, the Hon. T. E. Fell, C.M.G., gave me facilities for visiting the mountainous country of the interior which enabled much more of the island to be seen in that short time than would otherwise have been possible. To him and to other officers of the Government who assisted me in my tour I offer my best thanks. Mr. F. R. Charlton, the Acting Crown Surveyor, accompanied me on my coastwise journey and in a traverse across the island from north to south. His knowledge of the country and of the Fijian language and customs was invaluable. Major Caldwell, Mr. Reay, and Mr. Armstrong, the District Commissioners through whose areas we padded, gave us hospitality and every assistance possible, and Mr. Boyd, the Commissioner for Native Affairs, made arrangements with Fijian chiefs, in whose houses we were charmingly and hospitably entertained. When making the tour I had no intention of writing any account of it for publication, but several new facts came to light which it is desirable to place on record.
Some Unmapped Faults in the Lower Carboniferous of Westmorland and their Relation to the Dent Fault System
Authors: Miller A. A.
Published: May 2009

Summary and Conclusions

1. The Dent Fault diminishes in throw towards the north, and is almost non-existent 3 miles south of Kirkby Stephen.

2. The principal line of dislocation is then displaced about a mile to the east, where there is a steep monoclinal fold, replaced sometimes by a fault, running in a direction parallel to the Dent Fault and also having a downthrow to the east.

3. Further parallel faults, many of them hitherto unmapped, assist in the subsidence of the country to the east.

4. Cross-faults, in most cases with downthrow to the south, accommodate the margin of the “Rigid Block” to local increase or decrease of throw.

5. These two systems of faults are of approximately the same age, and were brought about by the same crustal movements.
The Stratigraphical Horizon and Field-Relations of the Holywell Shales and “Black Limestone” of North Flintshire
Authors: Sargent H. C.
Published: May 2009

In my paper on “The Massive Chert Formation of North Flintshire” certain views were expressed which do not accord with conclusions stated in various Memoirs of the Geological Survey. The object of this paper is to support my views by further evidence.
The Occurrence of Gypsum in the Tertiary Clays and Sandstones of Ecuador
Authors: Sheppard George
Published: May 2009

Gypsum or selenite is one of the commonest “decomposition” minerals found in connexion with the exposed surfaces of the Tertiary rocks in southern Ecuador. With the possible exception of the coarser grits and conglomerates, the normal sandstones are usually veined extensively by sheets of this mineral; it also occurs in a fibrous form (plates), in agglomerations of minute scalenohedrons, flake-like folia parallel to the bedding, and also in beautiful rosette-like or “stellate” groupings. In the typical clay shales or “gredas” the distribution of gypsum is not so general, though crystals or irregular groups of imperfectly shaped crystals occur on the weathered slopes or screes. In many localities, where a steep talus slope of shale forms the foot of a superimposing sandstone cliff, the scree itself is invariably covered with broken plates of gypsum in such profusion that from a distance it has the appearance of irregular masses of ice or glass. The platy form (which usually consists of parallel laminae with vertical fibres) is probably the most common and, in reality, each plate has been formed after the manner of a typical vein deposit.
Further Jurassic Fossils from Kenya Colony
Authors: Gregory J. W.
Published: May 2009

Mr. E. J. Wayland, of the Geological Survey of Uganda, has recently found three interesting fossils which throw further light on the age of the beds to the west and north of Mombasa. One of them is a cast of an ammonite in brown ironstone, which has been kindly examined by Dr. L. F. Spath; he says that being only a cast its specific identification is perhaps impossible. It is a Grossouvria, and he says it is very similar to several examples of G. lateralis (Waagen), from the Callovian anceps beds of Kachh. He identifies it as certainly a member of Siemiradzki's form-series of Perisphinctes balinensis, Neumayr. This identification is of interest as the fossil was obtained at the point 10/6 miles from Mombasa on the Uganda Railway. This position lies to the west of, and therefore at a lower horizon than, the ammonite-bearing shales near Mombasa. At 11 1/9 miles along the railway I found a lamellibranch in some dark shales and Dacqué (Geol. Rundsch., vol. i, 1910, p. 159) has recorded from near by some obscure Cephalopod and plant remains which he identified as Bathonian.
Vesuvianite and Grossular as Products of Regional Metamorphism
Authors: Tilley C. E.
Published: May 2009

The chemical environment of vesuvianite and grossular is typically revealed in their associated minerals, calcite, diopside, scapolite, and wollastonite, characteristically developed under the physical conditions prevailing in thermal metamorphism.
The Structure and Development of Sphenotrochus crispus, and Notes on Aporose Morphology
Authors: Ryder T. A.
Published: May 2009

A Porose corals have, with few exceptions, received little attention in Britain since the publication of works by P. M. Duncan and R. F. Tomes, during the latter half of last centary. The newer methods of investigation by means of thin slices and serial sectioning, so successfully employed by Drs. Stanley Smith and W. D. Lang, and others, in the Rugosa, were not then in use, and so very little is known of the internal structures–the only basis for classification and comparison–or of the developmental stages of the Aporosa.
A New Genus of Tabulate Corals from New South Wales
Authors: Jonas O. A.
Published: May 2009

The peculiar coral to be described below was collected by Mr. R. S. Allan, of New Zealand, at Yass, New South Wales. It has a superficial resemblance to Favosites but close examination shows it to be imperforate and to belong to the Chaetetidae. It shows so many characters of interest that it seems to merit a full description.
Notes on some Analyses of Egyptian Igneous and Metamorphic Rocks
Authors: Hume W. F. , Harwood H. F.
Published: May 2009

For some years Dr. W. F. Hume had desired to obtain additional analyses of Egyptian igneous and metamorphic rocks for the purpose of a detailed investigation he proposed to make of their nature and distribution. The Chemical Department of the Egyptian Government was, however, too fully occupied on current work for Government contracts, and could not undertake the specialized analytical work necessary.
Notes on the Structure of an Early Dictyonema.
Authors: Bulman O. M. B.
Published: May 2009

The more important points in connexion with the structure of D. flabelliforme are:—

1. The absence of any real approach to the spiral arrangement of the thecae along the stipes.1

2. The absence of a common canal; and the consequent budding of each hydrotheca direct from the preceding one.1

3. The initial constriction of each hydrotheca cavity.

4. The budding of the bithecae from the sides of the hydrothecae along which they lie.

5. The early stage at which the presence of the bithecae is observed.

6. The derivation, indifferently “right-handed” or “left-handed” of the crossing canal.

7. The nature of the dissepiments—hollow bars derived principally as outgrowths of the bithecae.
Chalky Boulder-clay in the North-West District of London
Authors: Mantle H. G.
Published: May 2009

At the commencement of the year 1925 the Post Office authorities, for the purpose of laying down telephone lines, were making a trench from the corner of Rochester Road (Camden Town) north-eastward up the Camden Road and across it into and along Murray Street in the direction of St. Paul's Road, and were laying ducts at the depth of about 10 ft. The distance from the corner of Rochester Road to a point opposite the corner of Murray Street is 160 yards, the direction north-east, with a slight rise in that direction. Previously the London County Council tramway cable ducts had been laid down to the depth of 3 ft. 6 in., but below this level the whole of the ground excavated was in an undisturbed state. The trench was 2 ft. 7 in. wide. A man-hole had been sunk at the corner of Rochester Road, another at the end of the works on the Camden Road, and a third opposite to it at the corner of Murray Street, all to a depth from the surface of more than 12 ft. In fact the Camden Road man-hole was sunk to the depth of 15 ft. 6 in., so as to enable the excavators to tunnel under the road to Murray Street in order that the stream of traffic along the Camden Road might not be disturbed.
On Some New Ammonoidea from the Chalk Rock
Authors: Billinghurst S. A.
Published: May 2009

As a result of work on the Chalk Rock in the Hitchin district during the last two years, I have obtained several Ammonoidea which differ in certain respects from those already figured and described and include two new species.
Mangaia and Rurutu: a Comparison between Two Pacific Islands
Authors: Chubb L. J.
Published: May 2009

Professor Patrick Marshall's important and interesting memoir, which has recently appeared, on the geology of Mangaia, one of the Cook Islands, inevitably suggests a comparison between this island and Rurutu in the Austral Group, which I visited in 1925, during the St. George Expedition to the Pacific, and described in a recent communication to the Geological Society. Owing to the shortness of the Expedition's stay at this island, my observations were necessarily somewhat incomplete, but I had the advantage of many conversations with Mr. S. Russell, who spent several months there in 1924, prospecting for minerals. He gave me copies of his reports, and he accompanied us on our visit.
The Petrography and Correlation of the Surface Deposits of South-east Devon
Authors: Shannon W. G.
Published: May 2009

Summary of the Conclusions

The petrography of the Plateau Deposits has been determined. They yield species both of local origin and of the general Haldon types.

The kyanite and staurolite present have been derived from the north.

The planation of the limestones was initiated during the Cretaceous period.

The raised beaches are of slightly different types, the Thatcher raised beach being later. They furnish evidence of a former greater thickness of the Plateau Deposits.

Modern beach deposits furnish some evidence of the distributive powers of certain minerals, and point to the existence of Triassic and Cretaceous sediments outside the Bay.
On Cyamocephalus, a new Synxiphosuran from the Upper Silurian of Lesmahago, Lanarkshire
Authors: Currie L. D.
Published: May 2009

The Upper Silurian rocks of Lesmahago, Lanarkshire, have long been known to contain Arthropod remains. In the Kelvin-grove Museum, Glasgow, are a number of curious forms from the Logan Water Lesmahago, which Professor McNair was good enough to allow me to examine. In the hope of solving some problems presented by them, I obtained, through the kindness of the Keeper of the Geological Department of the British Museum, the loan of a specimen from the same locality, which forms the subject of this note. Instead, however, of solving any difficulties, the specimen presented a new problem.
Fauna of the Brachiopod Beds at Cauldon, Staffs
Authors: Alkins W. B.
Published: May 2009

In a recent note Mr. J. Wilfrid Jackson, F.G.S., and the writer mentioned the occurrence at Cauldon, Staffordshire, at highly fossiliferous limestones, resembling those of the “Brachiopodbeds” of Castleton, Park Hill, Narrowdale, Thorpe Cloud, and other stations on the north-west, west, and south-west of the Staffordshire- Derbyshire limestone massif. It will perhaps be of interest to put on record the fauna of these beds, as far as it has yet been worked out, since the conditions under which they occur renders it highly improbable that any considerable amount of material will ever be available from them, and since they represent a phase which does not, so far as is known at present, occur to any extent in the more immediate neighbourhood of this station.
Founders of Seismology.—III. John Milne
Authors: Davison Charles
Published: May 2009

During the period of about ten years which included that of Mallet's death—say, five years before and five after—the study of earthquakes made rapid progress. Among the more prominent contributors were M. S. de Rossi and G. Mercalli in Italy, F. A. Forel and A. Heim in Switzerland, E. Suess in Austria, J. F. J. Schmidt in Greece, T. Oldham in India, and C. G. Rockwood and C. E. Dutton in the United States. Their work, however, was mainly carried out on the old lines. For the introduction of new methods of study and of a new spirit infused into seismology, we are indebted to the small band of early British teachers in Japan, to J. A. Ewing, T. Gray, and, above all, to J. Milne. In the new epoch, now opening, when seismology demanded the whole energy of its supporters as well as their active co-operation, it is not, I think, too much to claim that Milne lifted the science to an altogether different and higher plane.
An Outline of Chinese Geology
Authors: Lee J. S.
Published: May 2009

The apparent conflict in palæontological evidence is still more aggravated if the views of several able palæobotanists be taken into consideration. Plant-remains have been frequently found from the Shansian rocks in various parts of northern China. They amount to a copious flora. Numerous species are described by Newberry, Schenk, Abbado, Zeiller, Zalescky, and Yokoyama. In some cases these writers agree in assigning the flora to the Upper Carboniferous. The presence of Tœniopleris multinervis, which is said to have never been found in Europe below the Autunian stage, and a number of its allied species, such as Lepidodendron gaudryi, Calamites cf. leioderma, has, however, led Zeiller to conclude that the coal-bearing Shansian rocks in the Shan-si Province range from the highest Stephanian to the Lower Permian. Schenk also holds that the coal-bearing series of Kai-ping, eastern Chi-li, and that of Pen-hsihu, Manchuria, are of Permian age.
Some Remarkably Preserved Brachiopods from the Lower Magnesian Limestone of Durham
Authors: Trechmann C. T.
Published: May 2009

Several quarries in the neighbourhood of Shildon, near Bishop Auckland in South Durham, display interesting sections of the Lower Magnesian Limestones and the beds on which they rest. At present the most instructive is that at East Thickley, near Shildon railway station, and as there seems a probability in the near future of this quarry becoming obscured by pit refuse, a record of the section exposed in it seems to be desirable. A large part of the rock-face has already been so obscured. A short distance south-east of this one other quarries exist closely adjoining the railway, but they are now almost entirely filled up with rubbish though sections in the railway cutting may still be seen. About a mile south-west of Thickley across the railway a quarry is at present being worked near Midderidge Grange, and seems to be the one in which important reptilian and other vertebrate remains were found in the Marl Slate many years ago. Notable among these is the headless skeleton of Proterosaurus Huxleyi Hancock & Howse, each bone of which has the interior filled with galena. This and other important specimens are now in the Hancock Museum at Newcastle-on-Tyne. At present, however, the only rock visible in Midderidge Quarry is the dolomitic Lower Magnesian Limestone, in which no fossils are to be seen. These quarries are either, as in the case of East Thickley, situated on the junction of the Permian with the Coal Measures, or, in the case of Midderidge, very close to the junction.
On the Rocks of the Avon Section, Clifton
Authors: Reynolds Sidney H.
Published: May 2009

An account of the lithological succession of the rocks of the Avon Gorge was given at the Bournemouth meeting of the British Association in 1919, and a summary of the rock-characters mainly from the lithological aspect was published in the Geological Magazine (1919, p. 523). Further work has now been done, and a full account of the rocks is published in the current issue of the Quarterly Journal of the Geological Society. The following summary prepared for the above paper was considered redundant owing to the fact that the matter it contains is already incorporated in the text of the paper. In view, however, of the importance and accessibility of the Avon Section it is thought that a brief statement such as the following, in which the rock-characters are summarized firstly from a stratigraphical and secondly from a lithological aspect may be useful.
Mangaia and Rurutu—a Comparison between two Pacific Islands
Authors: Marshall P.
Published: May 2009

In an article with the above heading (GEOL. MAG., Vol. LXIV, 1927, p. 518) Mr. L. J. Chubb discussed the geology of these two small Pacific islands, which are somewhat centrally situated in the western part of the South Pacific Ocean.
Remarks on the Attachment of Dictyonema flabelliforme (Eichw.)
Authors: Bulman O. M. B.
Published: May 2009

The specimen to be described is from part of the McKenny Hughes Collection, preserved in the Sedgwick Museum, and was without any indication of horizon or locality. It is a slab of hard, light-grey, spotted shale, containing numerous examples of Dictyonema flabelliforme (Eichwald). The matrix is quite unlike any Dictyonema Shale known to the writer from extra-British localities, and from the general habit of the graptolites, supported by the lithology of the shale, the specimen is considered to be from some locality in Wales. In the view of Dr. G. L. Elles, who has examined the specimen, it may be part of a collection of D. flabelliforme made by McKenny Hughes from the Portmadoc district. A remarkable feature is shown in the proximal ends of three of the rhabdosomes, where the sicula terminates, not in a nema, but in a little tuft of root-like fibres.
The Petrology of Sark
Authors: Wooldridge S. W.
Published: May 2009

It is proposed to offer a few remarks as to the general relations of the rocks described to their associates in the Channel Islands, and in the Armorican Massif generally.
Is the Chalk a Chemical Deposit?
Authors: Tarr W. A.
Published: May 2009

The composition of chalk has been shown to consist dominantly of three types of material, in the order of their importance, (1) amorphous, or extremely fine-grained material, (2) spheres, and (3) organic remains.

The first, the writer believes, represents chemically precipitated calcite and aragonite, the second a chemically formed oolite, and the last the normal organic constituents.

Recent studies have shown that the surface waters of the ocean in favourable localities are saturated with CaCO3 and that variations in amount of CO2 mean either solution or precipitation. It is believed that the physical conditions of the Cretaceous sea favoured precipitation. Bacteria may have been a contributing factor.

It is hoped that the above suggestion of the possible chemical origin of a part of the chalk (the larger part) will cause those who have the opportunity of study to apply it further, for until the great amount of extremely fine material is accounted for the origin of chalk is not settled. The writer regards the chemical origin with favour because it seeks to explain the origin of chalk in the light of present knowledge of the precipitation of calcium carbonate from sea water.
Sedgwick Museum Notes. The Characteristic Assemblages of the Graptolite Zones of the British Isles.
Authors: Elles Gertrude L.
Published: May 2009

It has become increasingly evident during the past few years that there are many geologists working on the older Palaeozoic rocks in various parts of the British Isles, to whom a knowledge of the common assemblages of graptolites characteristic of our different British graptolite zones might be useful. In the following lists, therefore, an attempt has been made to put together the facts gleaned from the study of the Graptolite Shales of the British Isles in many widely separated localities. The lists do not claim to be in any way a complete representation of the entire fauna of any zone, but merely an enumeration of those graptolites which in the author's experience are most universally and abundantly represented, so that they are likely to be the forms met with most characteristically in an exposure of any particular horizon. Some co-mingling at the boundaries of the zones must naturally be expected, especially when dealing with a succession of purely shaly deposits, but as a rule even then the coming in of new forms in abundance should be taken as an index of the passage to a higher horizon. This fact is one upon which great emphasis should be laid, it is upon this coming in of new forms, usually indicative of a more advanced stage in evolution, that the basis of modern zonal stratigraphy is laid; the persistence of old forms tends to vary greatly in different localities with the richness of the previous fauna; when the fauna of the earlier zones was both rich and varied, there are naturally more survivors into the succeeding zones than when the fauna was a poor one.
The Occurrence of Boulders in the Tertiary Formations of Ecuador, South America
Authors: Sheppard George
Published: May 2009

Along certain of the coast sections in the province of Manabi, Ecuador, a series of large igneous boulders (of a coarse granitic type) occurs in situ among normal Tertiary sandstones. Tertiary sediments form the greater part of the “littoral” or coast belt of this country. One of the masses of rock referred to above had a weight, at least, of twenty tons—an exceptional size for an undoubted constituent member of a sandstone or a conglomerate.
The St. George Scientific Expedition
Authors: Chubb L. J.
Published: May 2009

Although the full account of the Geological work carried out by the St. George Expedition to the Pacific must await the working out of the specimens collected, the following brief preliminary notes may be of interest.
The Classification of the Acidaspidae
Authors: Reed F. R. Cowper
Published: May 2009

Since Dr. J. M. Clarke's1 attempt in 1890 to subdivide the Acidaspidae (= Odontopleuridae) by means of the characters of the occipital ring and its spines, several other methods of classification of the members of this family have been proposed. Van Ingen,2 in 1901, adopted Clarke's names for the subgenera which he raised to the rank of genera, but he slightly modified their definitions and preferred to use the name Acidaspidae for the family, as is general in Europe, dividing it into four main groups comprising six genera. Raymond,3 in 1916, was led to criticize Clarke's principle of classification, pointing out the unnatural association of species which resulted from its application, and he accordingly desired to alter the definitions of the genera as given in 1913 in the second edition of Zittel-Eastman's “Textbook of Palaeontology ” (vol. i, p. 722). Special attention was paid to the characters of the pleurae, as in Barrande's old scheme.
The Origin of Flint
Authors: Brydone R. M.
Published: May 2009

Mr. W. A. Richardson's paper in the December, 1919, number of this Magazine has furnished a very useful summary of the problem of the origin of flint, with some very interesting suggestions; but it cannot be allowed to pass altogether unchallenged.
Preliminary Notes on the Geology of the Ningi Hills Northern Nigeria
Authors: Williams Gerard W. , Rastall R. H.
Published: May 2009

THE country described in the following notes comprises the area lying between latitudes 10° N. and 11° 30′ N. and longitudes 8° 45′ E. and 10° E., and is situated in the northern portion of Bauchi province and the south-eastern portion of Kano province, Northern Nigeria.
Sedgwick Museum Notes: Notes on the Genus Sphaerocoryphe
Authors: King W. B. R.
Published: May 2009

Dr. F. R. Cowper Reed, in a paper entitled “Notes on the Affinities of the Genera of the Cheiruridæ”, points out that Sphærocoryphe belongs to the Cheiruridæ, while Staurocephalus, which has at first sight some superficial likeness to it, belongs probably to the Enerinuridæ.
On a New Ammonite Genus (Dayiceras) from the Lias of Charmouth
Authors: Spath L. F.
Published: May 2009

THE following account is based on the six specimens recorded by Dr. W. D Lang in his paper on “The Ibex-zone at Charmouth, and its relation to the Zones near it” After mentioning the occurrence, in the top of the zone, of an apparently new Polymorphitid, Dr. Lang added the following footnote: “A striking form, 3 to 4 inches in diameter, with numerous, very thin costæ. Two specimens were found (not in place) in the winter, 1915–16, by Lieut. Dan Haggard, who presented them to the British Museum. The author found parts of three specimens in place in the Pyritic Marls in June, 1916. A sixth specimen, the best preserved of all, has been in the British Museum many years, and is labelled ‘Said to be from Lyme Regis’.”
The World's Copper Production
Authors: Hatch F. H.
Published: May 2009

The following article originally appeared in the Times Trade Supplement of August 28 last. It is here reprinted with some small additions by the courtesy of the proprietors of that Journal.
Kent's Cavern. Mr. Northmore's Account of his Discoveries
Authors: Longworth-Dames F.
Published: May 2009

In connexion with the recent excavations in Kent's Carven, the following particulars relative to the discovery of the first organic remains by Mr. Thomas Northmore, F.S.A., of Cleve, near Exeter, in September, 1824, will prove of interest to many readers. They are given in a letter written by Mr. Northmore to the Editor of The Panorama of Torquay, 1832—Mr. Octavian Blewitt.