bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplementary Note on the Walton-Common Section
Authors: Hudleston W. H.
Published: October 2009

There seems to be so much uncertainty as to the character of the basal beds of the Lower Bagshots in the London Basin that any opportunity which affords us unmistakable evidence of their real nature should be seized without delay. We have had so much theorizing, based upon the evidence of well-sections and of limited exposures, that we turn with pleasure to a good continuous section like the one which has lately been disclosed between Walton and Weybridge on the London and South-Western Railway. The main features of the Lower Bagshot series in this section, at its actual junction with the London Clay, were very fully described by me in a communication made to the Society last year. Whether we regard the junction there shown as evidence of an unconformity or otherwise, the fact of a complete lithological change is patent to all.

1. Recapitulation of some points in the previous paper.

Resting immediately upon the grey-coloured and sticky London Clay, distinguished by its fine and perfectly regular bedding, is a sharp yellow sand full of current-bedding. This yellow sand I dabbed “No. 1 Bagshots.” Then follows the first clay series, which I called No. 2, or the “Blue Bagshots.” It is surmounted by a second sandy series, referred to in my previous paper as “No. 3 Bagshots.” As far as the new cutting for the widening of the line had then progressed, there was no reason to suppose that No. 3 was succeeded by a second clay series, beyond
On the Rocks of the Malvern Hills
Authors: Rutley Frank
Published: October 2009

The rocks of the Malvern Hills have already been the subject of much discussion, and some of our most eminent geologists have devoted a large amount of time and trouble to the unravelling of their history.

One of the most important papers, however, upon this subject was written by Dr. Harvey B. Holl, over twenty years ago; and with this paper and a few maps I have spent several weeks in examining the range.

The general result of this examination may be of interest, inasmuch as it enables me to confirm to a great extent the statements made by Dr. Holl, whose careful observations and sound inferences cannot fail to impress those who endeavour to follow up his work.

One of the main points which Dr. Holl wished to demonstrate was, “that the rocks which had hitherto been treated of as syenite, and supposed to form the axis of the hills, were in reality of metamorphic origin, and belonged to the Pre-Cambrian, Azoic, or Laurentian Age.” I think that, at the present day, many geologists will be found who are ready to accept this conclusion, in spite of the protest of the late Sir Roderick Murchison.

Dr. Holl, in his paper, discusses first the structure and origin of the crystalline rocks of the Malvern Hills, he next treats of the adjacent Palæozoic strata, and finally endeavours to show the chronological relationship of the several events in their geological history.

Without attempting to follow out such an extensive programme, I have
A Preliminary Inquiry into the Genesis of the Crystalline Schists of the Malvern Hills
Authors: Callaway Ch.
Published: October 2009

Introduction.

The igneous origin of some foliated rocks was first suggested to me by the granite of Northern Donegal
*
. The Rev. E. Hill, F.G.S., had previously noticed† a gneissic structure in the granite of Guernsey. Mr. J. J. Harris Teall, F.G.S., has described foliation in basic rocks in the North-western Highlands‡ and at the Lizard§. Schistosity in granitoid rocks has also been observed in the Alps by Professor Bonney, F.R.S. Besides English workers, several foreign writers, both American and Continental, have declared in favour of an igneous origin for certain schists, so that the production of a parallel structure in igneous rocks may fairly be regarded as an established fact.

The work which I have described in another paper (p. 517) led me to hope that we might be able to advance a step further. The intrusion of veins of granite in diorite, under pressure, suggested that at great depths, where pressures were at a maximum and chemical processes might be presumed to be most active, gneissic rocks of a more varied character might be produced. At the town of Galway I had seen gneisses which might have been produced in this way; but the crystalline schists of the Malvern Hills have furnished clear evidence of the genesis of some of the more complex gneisses, besides throwing additional light upon the production of the simpler schists. I am able to show that many of the schistose rocks of Malvern have an igneous origin, and I hope that the clues I
Notes on the Upper Keuper Section at Shrewley where the Fish were found, and on the Trias generally in Warwickshire
Authors: Brodie P. B.
Published: October 2009

As a rule, the Trias in Great Britain, considering its extent and thickness, is noted for the paucity and rarity of fossils, perhaps it is the most unfossiliferous of all rocks containing organic remains in this country, especially when compared with the abundant fauna and flora of the New Red Sandstone in Europe and other parts of the world. Any addition therefore to our knowledge in a field so comparatively barren is of considerable interest to the Palæontologist. It is now many years ago since I discovered
Palæoniscus superstes
, apparently the last of the genus, in the Upper Keuper at Rowington. Last summer, in company with my son, Mr. Douglas Brodie, I visited the sandstone-quarry at Shrewley, and he drew my attention to some obscure remains on a slab of sandstone which, when cleared, turned out to be portions of fish, unfortunately fragmentary and ill preserved, belonging to the genus
Semionotus
, which, though frequent in the German Keuper at Coburg, Stuttgardt, and elsewhere, has not been previously recognized here. On a second visit I found a few more in a somewhat better condition, all of which I placed in Mr. Newton's hands. On the slab on which the first specimens were found were two impressions of footsteps of a large
Labyrinthodon
, and I fancy that the whole number, seven, may have been lying on the surface of one large slab afterwards broken on removal. The following section of the quarry will show the probable position of most of the fossils
On
Chondrosteus acipenseroides
, Agassiz
Authors: Davis James W.
Published: October 2009

Two species of
Chondrosteus
have been described by Sir Philip Egerton, viz.
Chondrosteus acipenseroides
and
C. crassior
. Both were obtained from the Lias of Lyme Regis. The former species was known to Louis Agassiz, who named, but did not describe it (‘Poissons Fossiles,’ vol. ii. part 2, p. 280). In 1858 Egerton communicated a paper to the Royal Society (Phil. Trans. vol. xlviii. p. 871) on
Chondrosteus
, in which he described a number of specimens, which he referred to the species named by Agassiz and to the second one named above. The specimen which afforded the most perfect description was in a slab of indurated shale. A part of the head and the tail were missing; the length of the parts preserved was 15 inches, and the total length of the fish was estimated at 24 inches. This, together with examples of the head of
C. acipenseroides
, and a head and a good example of the tail of
C. crassior
, afforded a large amount of detailed information, on which Sir Philip Egerton was enabled to base the description and the determination of the genus. The characters of the species are indicated as follows (
loc. cit.
p. 883):—“The numerous specimens derived from smaller individuals present indications of two species, one having the bones of the head thin and smooth, the other being characterized by stronger cranial plates, having a granulated exterior. The anal fins of the latter are more massive, and have the transverse articulations at shorter intervals. I propose to
On the Ancient Beach and Boulders near Braunton and Croyde, in N. Devon
Authors: Hughes T. McKenny
Published: October 2009

The ancient high-level beaches of the south-west of England have long attracted notice. Paris referred some of them to blown sand; Carne and Boase mentioned the occurrence of similar phenomena around the coast of Cornwall. Godwin-Austen described a “raised beach” at Hope's Nose, and later on, in his paper on the superficial accumulations of the coasts of the English Channel, gave an account of several other deposits in different localities, which seemed to him to indicate an elevation of the coast-line. The position of many of these beaches is indicated by Greenough on his geological map and by De la Beche on the maps of the Geological Survey.

Among the raised beaches we generally find included the sandcliffs of Saunton Down and Middle Borough, on the coast west of Barnstaple. These deposits have a further interest attached to them from the occurrence at their base of large boulders of various kinds of rock, some of which, it would seem, do not exactly resemble any rock-masses in the drainage-areas from which they could have been transported to where they are now found by any kind of river-action.

Sedgwick, Murchison, Williams, and De la Beche have described these cliffs, pointing out the similarity of the deposits to those of the modern shore, and, assuming that the whole was an ancient beach, of course explained itz present position by changes in the relative level of land and sea. It seems to have been generally spoken of as a Raised Beach from the time
Further Observations upon
Hyperodapedon Gordoni
.
Authors: Huxley T. H.
Published: October 2009

It is now twenty-nine years since, in describing those remains of
Stagonolepis Robertsoni
from the Elgin Sandstones which enabled me to determine the reptilian nature and the crocodilian affinities of that supposed fish, I indicated the occurrence in the same beds of a Lacertilian reptile, to which I gave the name of
Hyperodapedon Gordoni
. I laid stress upon the “marked affinity with certain Triassic reptiles” (e. g.
Rhynchosaurus
) of
Hyperodapedon
, and I said that these, “when taken together with the resemblance of
Stagonolepis
to Mesozoic Crocodilia,” led me “to require the strongest stratigraphical proof before admitting the Palæozoic age of the beds in which it occurs”.

Many Fellows of the Society will remember the prolonged discussions which took place, in the course of the ensuing ten or twelve years, before the Mesozoic age of the reptiliferous sandstones of Elgin was universally admitted.
Hyperodapedon
was destined to play no inconsiderable part in the controversy. Some ten years after the discovery of the original specimen, remains referable to the same genus were found in strata of unquestionably Triassic age in Central and Southern England; and, about the same time, I received abundant evidence of the occurrence of
Hyperodapedon
, associated with Dicynodonts, Crocodilia, and Labyrinthodonts, in certain Indian rocks which, on other grounds, were strongly suspected to belong to the oldest Mesozoic series. An account of these new materials, together with a full description of the original specimen of
Hyperodapedon
, was read before the Society and published in the ‘Quarterly Journal’ for 1869.
On some Results of Pressure and of the Intrusion of Granite in Stratified Palæozoic Rocks near Morlaix, in Brittany
Authors: Bonney T. G.
Published: October 2009

In my paper on the “Structures and Relations of some of the Older Rocks of Brittany”* I briefly referred to the slaty rocks in the neighbourhood of Morlaix. As the main object of my journey was to study the older and, presumably, Archæan rocks of Brittany, only a moderate amount of time was devoted to those of later date, and not many specimens were collected. These, however, have proved of unusual interest; so I venture to offer a few remarks upon them to the Society, because, as I anticipated, they seem to throw some light upon the history of the genesis of certain crystalline schists.

The rock beneath and in the immediate neighbourhood of Morlaix consists of alternating bands, differing in texture and colour†. The grey material, at the time of deposition, was evidently a fine-grained silt or earthy sand, the dark a carbonaceous mud. The layers of the former commonly do not exceed an inch in thickness, and are often less; the others are frequently more; but extremely thin, more or less lenticular streaks of the one material are occasionally interlaminated with the other. Both are cleaved, the sandy band imperfectly, the dark band very completely. Commonly the planes of cleavage and stratification coincide, and then the rock has a compressed appearance; but minor folds and “wriggles” are frequent, so that the “stripe” is cut by the cleavage-planes at very different angles. In these cases the change in amount and direction of the cleavage, the thickening of
On the Obermittweida Conglomerate, its Composition and Alteration
Authors: Bonney T. G.
Published: October 2009

The series of specimens from Obermittweida entrusted to me for examination by Professor Hughes is a remarkably fine one. All those of the conglomerate are of a fair size, some weighing several pounds, and are carefully selected so as to show the nature both of the matrix and the included pebbles; there is also a piece of the neighbouring gneiss. The pebbles are, in form, both well rounded and subangular. Some of the smaller fragments, indeed, occasionally seem to be little, if at all, worn, while the larger, in three specimens at least, are true pebbles. Two of them are full three inches in diameter. More than one kind of rock is present. The matrix also varies from a rather coarse-grained micaceous grit, to a hard tolerably uniform rock, in which the individual constituents can barely be detected by the unaided eye. It is of a purplish-brown colour, and has evidently been subjected to a pressure definite in direction, which has produced, especially around the included pebbles, an incipient cleavage. These divisional surfaces are coated with a filmy mica, producing what I have already termed “sheen surfaces.” As is usual, they bend round the pebbles, like the husk around a nut, so that the presence of a concealed pebble is often indicated by a “varnished” ovoid swelling on the surface of the mass. The matrix, though clearly fragmental in origin, suggests that a certain amount of metamorphism
in situ
has taken place, and in this respect it reminds one of
On the Discovery of Trilobites in the Upper Green (Cambrian) Slates of the Penrhyn Quarries, Bethesda, near Bangor, North Wales
Authors: Woodward Henry
Published: October 2009

The Cambrian rocks of Wales, once so barren of all evidence of organic remains, have now, thanks to the late Mr. J. W. Salter and Mr. T. Belt, to Mr. Homfray of Portmadoc, but most of all to the researches of Dr. Henry Hicks, F.R.S., at St. Davids and elsewhere, become peopled with an extensive series of organisms, amongst which the Trilobites make up a large proportion of the fauna*

It is true that the
Longmynd Group
elsewhere had only yielded Annelide-burrows and a portion of a Trilobite (
Pal#x0153;opyge Ramsayi
); but the investigations of Dr. Hicks at St. Davids have contributed a Sponge (
Protospongia major
), two Ostracods (
Leperditia cambrensis
and
L. Hicksii
), eight Trilobites (
Agnostus cambrensis, Plutonia Sedgwickii, Paradoxides Harknessi, P. aurora, P. Hicksii, Conocoryphe Lyelli, C. bufo, Microdiscus sculptus
); in addition to which two
Lingulellœ
and two Thecœ must be added.

The following table shows the fauna of each formation, from the Longmynd up to the Tremadoc;—

Dr. Hicks writes:—“The Longmynd series, so well exposed in coast-sections at St. David's, is evidently identical with that of North Wales and Shropshire, the lithological characters and the order of succession being strangely alike. In Shropshire, North Wales, and Ireland they have yielded a few indications of life, but these districts
need further exploration
”*. How true was this last remark will be seen in the sequel.

On the 5th August last I received a letter and box of specimens from Professor James J. Dobbie, of the University College of North Wales, Bangor
On
Thecospondylus Daviesi
(Seeley), with some Remarks on the Classification of the Dinosauria
Authors: Seeley H. G.
Published: October 2009

In the Fox Collection in the British Museum is the anterior third of a vertebra,
with the number R/181 from the Wealden Beds of Brook, in the Isle of Wight, which indicates an animal of a type which hitherto has had but one other representative in Europe. With his usual acumen Mr. William Davies, F.G.S., recognized it as being the cervical vertebra of an animal closely allied to the genus Cœlurus of Marsh. No one would have been more competent than that veteran palæontologist to have written its history; and if I gladly undertake the task, it is because it enables me to suggest this honour to the work of a distinguished pioneer, whose labours on the Fossil Vertebrata have smoothed the way and facilitated the studies of every student of the National Collections for the last quarter of a century.

Imperfect as the specimen is, it may serve as a nucleus round which knowledge will accumulate, until the genus becomes as well known as the larger Wealden reptiles.

The centrum is elongated, compressed from side to side, with a flattened base, and flattened subquadrate anterior articular face, with the sides of the face prolonged backwards as subparallel sides, and as a ventral surface which is subparallel to the neural canal. The cervical ribs are co-ossified with the centrum and neural arch. The bony tissue, not unlike that of Ornithosaurs for its relative thickness, forms a dense external film, which defines the form of the
Supplementary Notes on the Stratigraphy of the Bagshot Beds of the London Basin
Authors: Irving A.
Published: October 2009

In this paper it is intended to lay before the Society the results of additional work in this Formation done during the year 1887. It deals with the succession of the beds all along the northern margin of the district, from Farley Hill near Reading to Englefield Green, and with the development of the formation in the more westerly portion of the area (basin of the Kennet).

Part I.

In this part of the paper I shall attempt to show from the description of numerous sections that the inference as to marginal conditions in my last paper is found to hold all along the northern flank of the district.

In the recent discussion of this subject some ambiguity has crept into the use of the term “Middle Bagshot.” For my part I have, as I believe, consistently used the term throughout with the exact connotation which I gave to it in the year 1883*, and in the Quarterly Journal of the year 1885 (vol. xli. p. 494). In the Wellington-College section it is seen to include beds of the horizons Nos. 3-10; and whenever I have found a complexus of beds answering in general physical character to these, I have assigned them to the Middle Stage without taking the empirical consideration of mere thickness into account; since in none of the deep-well sections of the interior of the district have we anything approaching to a recurrence of such a series in either the Upper or Lower stages.

North Flank
On the History and Characters of the Genus
Septastræa
, D'Orbigny (1849), and the Identity of its Type Species with that of Glyphastræa, Duncan (1887)
Authors: Hinde George Jennings
Published: October 2009

The circumstances which have given origin to the present paper are as follows:—On December 1, 1886, Prof. P. M. Duncan, F.R.S., read before the Society a paper entitled “On a new Genus of Madreporaria—
Glypkastrœa
, with remarks on the
Glyphastrœa Forbesi
, Edw. & H., sp., from the Tertiaries of Maryland, U.S.”*, and exhibited specimens of the form described as the type of a new genus. The statements made by this author and the characters depicted on his diagrams did not appear to me to be borne out by the corals exhibited, and I determined to find out for myself, by an independent and thorough investigation of all the specimens of the form which could be obtained, whether the history and character of the species,
Septastrœa Forbesi
, Edw. & H., supported the description given of it in the paper in question, and justified the removal of it from the genus
Septastrœa
, in which it had been originally placed by the French authors, to the new genus
Glyphastrœa
, proposed by Prof. Duncan.

The specimens which have been studied by me for the purposes of this paper are:—first, the acknowledged type of
Septastrœa Forbesi
in the collections of the British Natural History Museum, South Kensington, and several other examples of the same form preserved with it; also microscopic sections of the type form which, at my request, the authorities of the British Museum kindly had prepared for me to ascertain its internal structure; secondly, two beautifully preserved examples of the same species, belonging
On some additional Occurrences of Tachylyte
Authors: Cole Grenville A. J.
Published: October 2009

Since the spring of 1883, when I had the honour of being associated with Prof. Judd in a paper on the Basalt-glass of the Western Isles of Scotland*, a few additional occurrences of tachylyte in the British Isles have come under my notice in the field. Specimens have been thus collected from Ardtun in Mull, Kilmelfort in Argyll, from near Bryansford, County Down, in Ireland, and among certain older rocks of the Welsh border. I am also enabled, by the kindness of my friend Mr. A. W. Dymond, to give an account of the microscopic characters of the tachylyte of the Quiraing in Skye.

The Duke of Argyll, in his classic description of the leaf-beds of Ardtun in Mull†, refers to a glassy layer between two of the basaltic masses of the headland; and the same occurrence was mentioned by Mr. Koch during the discussion on the paper dealing with Scottish basalt-glass. Mr. J. Starkie Gardner, who called my attention to the rock upon the ground itself, has described and figured the course of an intrusive sheet that forms a very conspicuous feature at Ardtun‡. At its most accessible portion it is about 8 ft. thick, and in the centre still retains, as shown by microscopic examination, a considerable amount of colourless glassy matter. In this matrix cumulites and belonites are developed; plagioclase felspar is abundant, interspersed with brown prismatic augite, while the magnetite is collected into crystals that are often well defined. On a sea-face so exposed the
Description of a new Species of
Holaster
Authors: Jukes-Browne A. J.
Published: October 2009

Holaster, rotundus,sp. nov. (Plate XII.)

Description
.—Test large, rather thick, tumid, circular, or broadly ovate, but generally as broad as long. Upper surface elevated and sloping evenly all round towards the ambitus, Under surface flattened, but rounded at the border. Mouth opening in a slight depression near the anterior border; anal opening above the base on the posterior border, with a small depression or hollow below it. The dimensions of full-grown specimens are two and a half inches in breadth or transverse diameter and the same in length; height about two inches. The ambulacral summit is central; the ambulacra, which are straight, lanceolate, and apetaloid, radiate from it.

The anteal sulcus is feebly developed, the depression in front of the mouth being continued for a short distance along the ambulacral area, but hardly far enough to break the circular outline when the test is viewed from the summit.

Both the antero- and postero-lateral ambulacra are straight and nearly equal; the poriferous zones are similar and narrow; the pores are clearly visible from summit to base, about 50 being visible in each avenue of the anterior pair, but not quite so many on the posterior pair. The apices of the three anterior pairs converge at a little distance from the posterior pair, just as in
Holaster subglobosus
.

The composition of the apical disk appears to be as usual in the genus
Holaster
, and the madreporiform body is distinct in the specimens examined.

The interambulacral areas are formed of large wide plates, those
Notes on a Recent Discovery of
Stigmaria ficoides
at Clayton, Yorkshire
Authors: Adamson Samuel A.
Published: October 2009

T
he
extensive quarries of Messrs. Murgatroyd and Sons, at Fall Top, Clayton, near Bradford, Yorkshire, are now justly celebrated, not only for the excellence of the stone worked there, but also for the discovery of the finest and most fully developed examples of
Stigmaria ficoides
yet seen. The bed of stone, which is so famous throughout the country, owing to its durability when used for landings, flags, &c., and known as the Elland Flagstone of the Lower Coal-measures, is here extensively quarried. In this neighbourhood the sequence of the beds in descending order is as follows: first, the Better-Bed Coal, then some 30 feet of irregularly bedded and raggy sandstone, followed by about 40 feet of sandy shale, and finally the lower flagstone, which is of great thickness. It was in the measures above the lower flagstone, and about 5 feet below the surface, that the stump of this large fossil tree was found. The raggy stone and shale is of little commercial value, and Messrs. Murgatroyd have to resort to blasting operations to remove it. In November 1887, during this work, the ramifications of the roots of a large tree were partially exposed, and the firm at once gave orders that they should be carefully bared. These praiseworthy instructions were skilfully followed by their workmen, with the result that this splendid example could be perfectly seen (see plan, p. 375). The stump rose a little above the surface on which the roots were almost horizontally extended. When first exposed,
On the Eruptive Rocks in the Neighbourhood of Sarn, Caernarvonshire
Authors: Harker Alfred
Published: October 2009

T
he
district to be treated lies to the west and south of the village of Sarn, near the south-western extremity of Caernarvonshire. The eruptive rocks there exposed, excluding outlying patches, occupy an area of irregular shape, which
extends about 5¾ miles from north to south, and has a greatest breadth
of about 2¼ miles. This part of the country has received but brief notice from Sir A. Ramsay in his memoir on the “Geology of North Wales”, and from Dr. Hicks, who claims a portion of the area for his Pre-Cambrian systems. Several specimens from the district have been described by Professor Bonney and the late Mr. Tawney, and the latter has also made a few observations on the field-relations of some of the rocks; but with these exceptions we have no published information about the western part of the Lleyn peninsula, though there are probably few districts of equal size in Britain where so many interesting rock-types are to be met with.

The rocks will be discussed in the following order :—Granite and Gneissie Granite ; Gabbro, Diorite, and Gneissic Diorite; Diabase; Hornblende-Diabase; Hornblende-Picrite; and Dolerite. Some of these, however, are but little developed, and, for most purposes, the rocks of the district may be divided into two groups—an acidic, developed in the north and west, and a basic and intermediate in the east and south. Mr. Tawney and Dr. Hicks have pointed out that the map of the Geological Survey
On the Cae Gwyn Cave, North Wales
Authors: Hicks Henry
Published: October 2009

The recent researches at Cae Gwyn have proved most conclusively that there was no foundation for the views of those who contended that the drift which crossed over the entrance and extended into the cavern was
remanié
, and had gradually crept down the hill. They have shown beyond the possibility of doubt that the deposits which overlie the bone-earth are
in situ
, and are identical with the typical glacial deposits of the area. It was found also that these deposits had at one time extended continuously across the valley above this elevation (400 feet above ordnance datum), and that the caverns had consequently been completely buried beneath them. The explorations carried on in 1885, 1886, and 1887, in the Cae Gwyn and Ffynnon Beuno caverns, show that they must have been occupied by the animals before any of the Glacial deposits now found there had accumulated, also that a thick floor of stalagmite had formed over these remains before the caverns were subjected to water-action. This action broke up the floor and completely re-sorted the materials, evidently washing out some, but also adding sandy and gravelly material to the deposits. Very large blocks of limestone, which were found at many points in the caverns, had evidently been disturbed by the same force, and had in many cases protected the original contents; they were, however, invariably found in the lowest deposits, and were covered over by laminated clay, sands, and gravels. It is certain that the caverns had been completely filled
The Greensand Bed at the Base of the Thanet Sand
Authors: Gardiner Margaret I.
Published: October 2009

This bed may be seen at various points from Pegwell Bay in the east to Chislehurst in the west of Kent, and there is a bed at Sudbury, in the N.W. corner of Suffolk, which Mr. Whitaker considers to be the same. At Lewisham and Croydon, to the west of Chislehurst, it is missing, and the light buff micaceous sand which usually succeeds it in West Kent rests directly on the flint bed above the chalk; so that, unless either the 9 inches of greensand and flint or the 2 feet of grey sand last seen in 1830 at Epsom by Prof. Prestwich are the same, the succeeding beds of the Thanet Sand overlap it westwards.

Specimens have been obtained from Pegwell Bay, Chislet near Herne Bay, Upnor, Chislehurst, and Sudbury. Leaving for the present the Sudbury sand out of consideration, this basement bed is a very fine sand formed of about equal quantities of dark and light grains mixed with more or less clayey matter. Its appearance in a section varies considerably with the weather, for it is the dark greenish grey of the darker grains which gives the colour when it is wet ; but when it is dry the clayey matter becomes a white powder, and is a much more conspicuous constituent. A microscopic inspection shows the sand to consist of quartz, flint, glauconite, and small quantities of felspar and various rarer minerals, with a few casts of microscopic organisms.

Quartz
.—The quartz is in not much rounded
On the Durham Salt-District
Authors: Wilson E.
Published: October 2009

The new salt-field in the North of England occupies the low-lying country bordering the estuary of the Tees, situate partly in Yorkshire, partly in Durham, and bounded by the Magnesian Limestone district of Durham on the north, by the Jurassic hills of Cleveland on the south, and by the German Ocean on the east.

At the present time this salt-field has a proved or fairly indicated area of at least twelve square miles. Of this area, however, more than half lies beneath the sea, and is therefore inaccessible by the only system of working at present in operation in the district. Beyond these limits, however, the Durham salt-field has probably a wide extension. Evidences of a limitation of the field in a northerly and also in a westerly direction have, indeed, been obtained; but what are its boundaries on the south and on the east we have not as yet, and perhaps never shall have, any means of determining.

Discovery of the Rock-salt at Middlesborough and Origin and Progress of the Salt Industry in South Durham.

In the year 1859, Messrs Bolckow and Vaughan, the celebrated ironmasters of Middlesborough-on-Tees, being in want of water at their Middlesborough Ironworks, had a borehole, 18 inches in diameter, put down to a depth of 1200 feet. Although large supplies of water were yielded by the more pervious strata passed through in this boring, this water was so highly charged with sulphate of lime as to be quite unfit for the purposes for which
On the Horizontal Movements of Rocks, and the Relation of these Movements to the Formation of Dykes and Faults and to Denudation and the Thickening of Strata
Authors: Barlow William
Published: October 2009

I propose to call attention to some horizontal movements of rock occasioned by gravitation, the importance of which has, I believe, been almost entirely overlooked, and shall try to show that the great forces of denudation in many cases owe much of their power to fissuring and dislocation produced by these movements, also that to these movements is to be referred the production of dykes and faults.

In the Grand Cañion District of the American Union a wide expanse of elevated horizontal strata, some thousands of square miles in extent, has been denuded in such a manner as to display a succession of huge terraces or steps of successive strata, each terrace being terminated by a sinuous line of cliffs or abrupt slopes.

Between the succeeding escarpments the strata dip slightly from the crest of the one below to the foot of the next above. In the median parts of any given terrace the strata are very nearly horizontal and have inclinations scarcely exceeding one degree;
but as we approach the escarpment of the next higher terrace, the inclination increases to three or four degrees, becoming a maximum at the base of this wall
.

The cumulative effect of the slight dip thus displayed, which for the most part has a northerly direction, is that the top of a certain stratum, the Carboniferous, is more than 8000 feet lower at the north, below the topmost terrace, than at the south, where it comes to the surface and forms a wide plateau,
The Permian Rocks of the Leicestershire Coal-field
Authors: Brown Horace T.
Published: October 2009

(1) Stratigraphical

The exposed Carboniferous strata of the Leicestershire Coal-field are bounded on their western edge by a narrow strip of course current-bedded sandstones and conglomerates, which form the base of the Trias in this part of the country, and which are doubtless homotaxial with the typical Bunter Conglomerate of South Staffordshire, Shropshire, and Cheshire. These sandstones and conglomerates are about 120 feet in thickness on the extreme margin of the Coal-field, but when traced eastward for two or three miles, by the aid of several outliers, they are found to thin out rapidly, and, east of a line drawn north and south through Ingleby and Measham, are conformably overlapped by the Keuper.

The Trias, throughout the greater part of the area, rests upon the truncated edges of Carboniferous rocks, either upon Coal-measures, or, in the northern part of the district, upon Millstone Grit or even Yoredale Shales; there are, however, found here and there, intercalated between the Bunter and the Carboniferous, some thin beds of purple marls, breccias, and sandstones, seldom exceeding in aggregate thickness 30 or 40 feet, but differing remarkably, in lithological characters, from both the overlying and underlying rocks.

My attention was first seriously directed to these rocks during a re-survey, on the six-inch scale, of a tract of country lying immediately to the east of Burton-on-Trent, and the results obtained induced me to make a careful examination of the beds throughout the Coal-field; for, although described and mapped as Permian by the Survey geologists, doubts
Notes on the Radiolaria of the London Clay
Authors: Shrubsole W. H.
Published: October 2009

Microscopical examination of London Clay from wells in Sheppey and elsewhere, and from pit-sections at the same horizon in different parts of the London Basin, continued for some years, has afforded proof of the existence near the base of this formation of a Diatomaceous zone, which was constant so far as the examination extended. It yet remains for some one to ascertain whether this zone continues throughout the full extent of the London-Clay area. The list of specimens given in my paper “On the Diatoms of the London Clay” (Journ. Royal Micr. Soc. vol. i. p. 381) has since been considerably enlarged by Mr. Kitton and others, from washings supplied by myself.

In a paper “On the New Town Well at Sheerness” (Proc. Geol. Assoc. vol. v. p. 355), I had previously called attention to 60 species of Foraminifera and some other microzoic forms not specifically mentioned. Among these latter were some reticulated fragments suggestive of Radiolaria, but no specimens occurred sufficiently perfect to be described. My friend Dr. Bossey, F.R.M.S., of Redhill, was more fortunate in this respect than myself, for in 1881 he saw and sketched a Radiolarian skeleton, apparently nearly perfect, which he had found in some London-Clay washings sent to him by me.

The formation of a well for the Queenborough Cement Company in 1885, near the Railway Station, gave me another opportunity of searching for new forms of Tertiary life. In accordance with previous experience, after passing through a zone rich in brightly glittering patches
Trigonocrinus
, a new Genus of Crinoidea, from the “Weisser Jura” of Bavaria; with the Description of a new Species,
T. liratus
.—Appendix. Sudden Deviations from Normal Symmetry in Neocrinoidea
Authors: Bather F. A.
Published: October 2009

Locality and Horizon.

The National Collection contains a large amount of material from the White Jura of Würtemberg and Bravaria. The exact horizon and locality of the specimens is often doubtful. Several hundred calyces of Eugeniacrinus, chiefly E. caryophyllatus, together with some thousand stem-fragments of the same genus, are said to come from Streitberg, which is a locality for Upper Oxfordian fossils in the district of Ober Franken. In sorting this abundant material the two specimens that I now propose to describe were found. The remains in question consists of calcspar tinged a dirty yellow; they appear to have been washed out of a yellow marly matrix. They probably occured in the same bed as the Eugeniacrini; and, after a comparison with fossils in continental museums, I am inclined to refer them to the “Weisser Jura a.” It is greatly to be regretted that no more certain evidence is available.

Description of the Specimens.

Imagine an amphora of triangular section with an “ear” at each corner in the shape of a spine, the mouth fairly broad, the bottom broken off, and the whole only 4 mm. high. Such gives a fair idea of these singular fossils. It will be convenient to distinguish the two specimens as A and B.

Specimen A is the more perfect of the two, especially at the lower or aboral end.

There is no trace of a Stem in the specimen, nor are there obvious signs of a sutural surface on the aboral ends of the
Notes on the Petrographical Characters of some Rocks collected in Madagascar by the Rev. R. Baron
Authors: Hatch Frederick H.
Published: October 2009

T
he
rock-specimens here to be described were collected by the Rev. R. Baron during his extensive travels through Madagascar. They do not by any means represent the whole of his collection; but care has been taken to make the collection include all the more important types of crystalline and volcanic rocks.

The paper is divided into two parts, the first dealing with the older crystalline rocks, and the second with the comparatively recent volcanic eruptions.

I. T
he
O
lder
C
rystalline
R
ocks

The mountainous portion of Madagascar, extending from north to south through the eastern half of the island, is a ridge of old crystalline rocks, on the western flanks of which volcanic rocks have been erupted. Mr. Baron's collection comprises both foliated rocks (gneisses) and rocks in which there is no parallel structure visible in the hand-specimen (granite, gabbro or norite, pyroxene-granulite, and pyroxenite).

In the following pages the petrographical characters of these rocks will be described briefly, the order as here given.

1. G
neiss

Considered petrographically, the specimens of gneiss, collected by Mr. Baron, may divided into an acid and a basic series, the former being characterized by the presence of abundant quartz with orthoclase as the dominant felspar, the latter by the subordination of the quartz and the predominance of plagioclase felspar.

a.
Acid Series (Granite-Gneiss).

To this division belongs a type of gneiss very common in Madacasgar and occuring, for instance, in the immediate neighbourhood of the capital. It is a medium-grained rock with a granitoid texture, foliation
The Basals of Eugeniacrinidæ
Authors: Bather A.
Published: October 2009

In the course of my paper on
Trigonocrinus
I had occasion to refer to the views held by various writers as to the position of the basals in the Eugeniacrinidæ. As the question was then gone into thoroughly, and as the occasion is so recent, it is unnecessary to recapitulate the arguments there employed. Suffice it to say that I adopted the opinions of Prof. E. Beyrich and Prof. K. von Zittel in preference to those of Mons. P. de Loriol § on the one hand, and of Dr. P. H. Carpenter ∥ on the other. Dr. Carpenter, who was present at the reading of my paper, and joined in the discussion, was not wholly convinced by my arguments; at the same time he admitted that, if the specimens alluded to by Beyrich and v. Zittel showed the course of the axial canals to be as described by those authors, then I should be entirely justified in following their views as to the basals, anomalous though the said views appeared to him to be.

I had already spoken to Prof. v. Zittel on the subject and could not doubt the accuracy of his observations any more than his good faith. The sceptical attitude, however, maintained by Dr. Carpenter in all his discussions with me, both private and public, induced me to write to Prof. v. Zittel; for it should be remembered that neither Beyrich nor v. Zittel had ever described the actual specimens on which they based their conclusions, and
On the Action of Pure Water, and of Water saturated with Carbonic Acid Gas, on the Minerals of the Mica Family
Authors: Johnstone Alexander
Published: October 2009

In papers which have been published in the ‘Transactions’ of the Royal and Geological Societies of Edinburgh, the Author has already given preliminary accounts of certain of his researches into the nature of the action of water saturated with carbonic acid gas on the following mineral and rock substances:—Orthoclase, oligoclase, labradorite, muscovite and biotite, hornblende, augite, olivine, steatite, magnetite, hæmatite, calcite, siderite, and statuary marble (crystalline limestone).

In the present communication he wishes to give some details of observations noted, and results of experiments carried out, while engaged in recent investigations into the nature of the changes produced by pure distilled water, and also by water saturated with carbonic acid, on the principal members of the mica family of minerals.

C
lassification
O
f
T
he
M
icas

It is convenient for all ordinary purposes to arrange the micas into two great classes. Division I. comprehends the varieties which are
anhydous
or practically so; Division II. includes the micas which are most distinctly
hydrated
.

Division
I.

In this section the micas generally known as muscovite (including lepidolite &c.) and biotite (including phlogophite and lepidomelane &c.) are placed. They are specially characterized by the possesion of a splendent or shining lustre, and of a high degree of elasticity in their fine laminæ. Normal specimens of these of these varieties contain usually from about 1 to 1·9 per cent of water, and none belonging properly to this division have more than 2·5 per cent of that liquid in their composition. They pass, however, quite gradually, by
On the Ashprington Volcanic Series of South Devon
Authors: Champernowne Arthur
Published: October 2009

There exists in South Devon an extensive series of igneous and quasi-igneous rocks occupying a considerable area, mainly east of the River Avon, which have as yet received scarcely more than passing notice, and the study of which is attended with much perplexity

Sir Henry De la Beche noticed the Yalberton trappean rocks south-west of Paignton, which are included in our subject, and spoke of them as interposed between the Yalberton limestone and that of Watton, which forms the western termination of the Berry Head mass. The relations of the igneous rocks to the Devonian limestones will be considered
de novo
as we proceed.

Dr. Holl mentions the rocks of this series in the neighbourhood of Totnes, Ashprington, &c, as “thick slates, in which much volcanic matter is disseminated.” He observes that“volcanic rocks are frequent,” and that “beds which are light-coloured often yield a red soil.” This was written with reference to rocks which occupy the ground between Harberton and the Dart. Though we might reasonably take exception to the term “slates” as not strictly applicable to any portion of these rocks with which we are acquainted, yet as it is quite certain that Dr. Holl well appreciated the importance of the group, and as no spot could be pointed out where they attain a greater development than [at] Ashprington and its neighbourhood, the provisional term “Ashprington volcanic series” has been here retained.
The Rocks of Alderney and the Casquets
Authors: Hill E.
Published: October 2009

1.General Description.

Alderney is seldom visited and has been seldom described. It deserves both description and visit. Macculloch gives an account of it in the first paper of the first volume of our ' Transactions.' Ansted,in his ' Channel Islands,' notices many features with accuracy, and seems to have taken a special interest in the place. Since his time I am not aware of a single addition to our knowledge until theadmirable map of France by MM. Vasseur and Carez, sheet No. IV.N.E. of which assigns colours and letters to the island. After the first draft of this paper had been written, a paper by M. Bigot
*
came into my hands, containing, besides notes on Jersey and Guernsey, a brief but excellent description of Alderney, which includes several of the facts that I have independently discovered.

I have to thank Professor Bonney for invaluable notes on the rock-sections, which he has allowed me to incorporate in this paper.

Alderney is an oval island (see: Map, p. 381
†
),
about 3½ miles long by 1 mile broad, lying E.N.E. to W.S.W. The western portion is a tableland just over 300 feet in height, which, along the west and south, falls in grand cliffs to the sea, but slopes to the shore along the north-western side. The eastern extremity is separated from this by lower ground and the deep indentation of Longy Bay, but above the Mannez Qualwy and at Fort Albert there are elevation of 140 feet and 180 feet respectively.
Note on the Pelvis of
Ornithopsis
Authors: Seeley H. G.
Published: October 2009

In 1874, on the occasion of my first visit to Eyebury to examine the fossil reptiles of the Oxford Clay, Mr. Alfred N. Leeds, and Mr. Charles Leeds, M.A., mentioned to me the following circumstance. A well had been sunk at the gas-works at Peterborough, which, at the depth of 36 feet, came down upon a number of bones of a large terrestrial reptile. It is well known that to the west of Peterborough the Cornbrash and Lower Oolites rise from beneath the base of the Oxford Clay. The well passed through 24 feet of blue clay, which Mr. Leeds had no difficulty in recognizing by its fossils as typical Oxford Clay. Beneath the clay were 12 feet of grey sand, nearly white in places, and fine-grained, but it was uncertain whether the bedding which it showed was current-bedding, Beneath the sand were the bones resting on the underlying clay. Mr. Charles and Mr. Alfred N. Leeds were fully aware that the remainder of the skeleton was probably on the spot, and made overtures to the Gas Company to allow them to drive a horizontal shaft in the hope of finding it. The bones found remained exposed to the weather for some time till they began to crumble beyond recognition and ceased to be interesting, when they passed into the hands of the most enthusiastic and able explorers who have worked the Oxford Clay.