bluuebunny/crossref_metadata_2025 huggingface dataset:
II.—Graphical Methods in Field-Geology
Authors: Harker A.
Published: May 2009

In determining the actual position of strata from the appearances presented by their exposed edges in natural and artificial sections, certain mathematical problems are of constant occurrence. To a field-geologist who is not content with rough guesses founded on judgments by eye, the solution of these problems is a matter of importance, and methods have accordingly been given for some of those most frequently met with. These solutions take the form of (1.) trigonometrical formulæ, which can be applied only with the aid of trigonometrical and logarithmic tables; (2.) tables specially prepared from these formulæ for use in the field; (3.) graphical methods, requiring only a ruler, scale and protractor, which may be conveniently combined in one instrument. Of the first kind is the formula for deducing the true dip of strata from two apparent dips, given in Green's Geology (p. 341, 1st ed.), etc. Among special tables are those of Mr. Jukes for finding the apparent dip in any direction from the true dip, and for connecting the dip, thickness and depth of beds: these tables are given in the appendix to the Survey Memoir on the Geology of the South Staffordshire Coal-field, and reproduced in Jukes's “Manual of Geology.” Graphical methods have been used for finding the true dip from two apparent dips: a method partly graphical but requiring a table of cotangents is given in Phillips's “Treatise on Geology” (p. 298, 5th ed.), and also by the Rev. E. Hill (Geol. Mag. 1876, p. 334); a purely graphical method by Mr. W. H. Dalton (Geol. Mag. 1873, p. 332); and an approximate method by Mr. Penning (Geol. Mag. 1876, p. 236), reproduced in his “Field Geology.” As Prof. Green has pointed out (ib. p. 377), the last-named method is equivalent to taking the angle for its tangent, and so applicable only to small angles of dip. Mr. Dalton's solution (loc. cit. p. 334) of another question, to find the effect on strata already inclined of a second tilt in a new direction, is only an approximation, and cannot be applied if the dips are considerable. It is erroneously assumed that the inclination of the strata in a direction at right angles to that of the second tilt is unaltered by the tilting.
IV.—The Sea Against Rain and Frost; or the Origin of Escarpments
Authors: Mackintosh D.
Published: May 2009

As every part of the crust of the earth has at one time been the surface, it follows that all questions connected with the origin of the present “form of the ground” must be very impotant, and that on their issue the progress of Geology must in a great measure depend. But on this subject a very wide difference of opinion at present exists. According to one party, consisting of Professor Ramsay, Mr. Jukes, Mr. Geikie, Colonel Greenwood, Dr. Foster, and others, the more abrupt inequalities of the earth's surface have been produced by subaërial or atmospheric causes. According to the other school, embracing Sir Charles Lyell, Sir Roderick Murchison, Professors Sedgwick and Phillips, Mr.Edward Hull, etc., the sea has been the principal denuding or excavating agent.
IV.—“Bergstürze,” or “Landslips”
Authors: Irving A.
Published: May 2009

As recent events in Switzerland have called the attention of the world to these startling phenomena, perhaps a short summary of what is known of them may be of some service to the readers of the Geological Magazine. In the text-books in use in this country they generally receive little more consideration than the comparatively small scale, on which ‘landslips’ occur in England, would seem to claim for them; and these for the most part occur on the sea-coast. Examples familiar to most of us are such as those of the Isle of Wight, where the Upper Cretaceous strata are known from time to time to slide over the Gault, which is locally known as the “blue slipper,” and that between Seaton and Lyme Regis. On the west coast of South America, in Ecuador, they have been known to occur on a much more gigantic scale in recent years. The tertiary strata of the district of more than 400 feet in thickness consist of sandstones interbedded with clays, and dip towards the coast. The erosive action of the sea eating away the base of the cliffs, and the clays getting softened by water, an enormous portion of the upper strata descended into the sea during the years 1870 and 1871. The landslip of Naina Tal is also fresh in the recollection of most of us. It is however in connexion with the Alps that I propose here to treat of phenomena of this class. The worn-down stumps of ancient mountain-systems which these islands furnish give us only a faint idea of the importance of Bergstürze in relation to the physiography of the Alps, which are of comparatively recent elevation.
IV.—On Some New Railway Sections and other Rock Exposures in the District of Cave, Yorkshire
Authors: Keeping Walter , Middlemiss C. S.
Published: May 2009

The country between Market Weighton and the Humber is characterized geologically by the reappearance of the Oolites along an outcrop of ten or a dozen miles, after having disappeared under the Cretaceous beds further north at Acklam Brow, near Malton.
V.—On the Brecciated Bed in the Dimetian at St. Davids
Authors: Hughes Thos. M'Kenny
Published: May 2009

In recent discussions upon the classification of the Archæan, great importance has naturally been attached to the occurrence of beds of fragmental origin. In the distinctly volcanic beds these are numerous; in the older or more highly metamorphosed portion of the group they are less frequent and their character and origin are more obscure.
I.—The Secret of the Highlands
Authors: Lapworth Charles
Published: May 2009

The theory of the gradual formation of overfolds and overfaults in a stratified system is thus developed by Professor Heim:—

Wherever a stratified rock series is subjected to the lateral horizontal thrust of the earth’s crust, a fold is originated. This fold consists of two opposed and symmetrical members, with more or less remote axes, viz. (Plate VIII. Fig. 1)
VI.—Does Elephas primigenius occur in the Norfolk Forest Bed?
Authors: Gunn John
Published: May 2009

I have been urged so strongly to state what is the result of my researches, with respect to the presence of Elephas primigenius in the Forest-bed series, that I am induced to offer the following remarks for insertion in the Geological Magazine.
IV.—The Pleistocene Geology of the Firth of Tay and the “Elevation and Subsidence” Question
Authors: Durham James
Published: May 2009

Within the last few months a good deal has been written upon the question of upheavals and depressions in the crust of the earth both in the Geological Magazine and in “Nature.” By far the majority of these writers have maintained with some show of reason that depressions are the result of the deposition of material of some sort on a part of the earth where it was not previously, in consequence of which the newly loaded part sinks down, just as a weight placed upon an air cushion causes the part on which the weight rests to be depressed. This novel view has been supported by pointing to the fact that numerous instances are met with in which vast thicknesses of rocks have been superimposed one upon another, while throughout their whole depth traces of shallow or comparatively shallow water are found, it being inferred that the sedimentary deposit being the cause of the depression, the bottom sinks exactly in proportion to the amount of the deposit. The Carboniferous system has been advanced as a conspicuous instance of this state of matters; the same holds true of the lower Old Red Sandstone, which appears to have been deposited in lakes.
II.—On Traces of Glaciers in the English Lakes
Authors: Bonney T. G.
Published: May 2009

Although the causes of the configuration of the Lake district have been discussed by Mr. Mackintosh in some interesting communications to this Magazine, and the distribution of the granite blocks from Wastdale Crag formed the subject of an able paper read by Professor Phillips to the British Association at Birmingham, 1865, the glaciation of this region seems scarcely to have attracted the attention which it deserves. In the hopes, then, that some one may be induced to do for North Wales, I venture the following remarks; although, owing to want of time and other causes, they are far less complete than I could wish them to be.
IV.—Further Notes on a Collection of Fossil Shells, etc., from Sumatra (obtained by M. Verbeek, Director of the Geological Survey of the West Coast, Sumatra). Part IV.
Authors: Woodward Henry
Published: May 2009

This cast indicates a fusiform turrited shell adorned by discontinuous varices; the spire is wanting; it also shows that the shell was transversely ribbed and corrugated; the outer lip was strongly plicato-dentate internally; the aperture rather small; canal moderately long.
III.—On the Physical Cause of the Submergence and Emergence of the Land During the Glacial Epoch
Authors: Croll James
Published: May 2009

An ordinary glacier descends in virtue of the slope of its bed, and, as a general rule, it is on this account thin at its commencement, and thickens as it descends into the lower valleys, where the slope is less and the resistance to motion greater. But in the case of continental ice, matters are entirely different. The slope of the ground exercises little or no influence on the motion of the ice. In a continent of one or two thousand miles across, the general slope of the ground may be left out of account; for any slight elevation which the centre of such a continent may have will not compensate for the resistance offered to the flow of the ice by mountain ridges, hills, and other irregularities of its surface. The ice can move off such a surface only in consequence of pressure acting from the interior. In order to produce such a pressure, there must be a piling up of the ice in the interior; or, in other words, the ice-sheet must thicken from the edge inwards to the centre. We are necessarily led to the same conclusion, though we should not admit that the ice moves in consequence of pressure from behind, but should hold, on the contrary, that each particle of ice moves by gravity in virtue of its own weight; for in order to have such a motion, there must be a slope, and as the slope is not on the ground, it must be on the ice itself: consequently, we must conclude that the upper surface of the ice slopes upwards from the edge to the interior. What, then, is the least slope at which the ice will descend? Mr. Hopkins found that ice barely moves on a slope of one degree. We have therefore some data for arriving at least at a rough estimate of the probable thickness of an ice-sheet covering a continent, such, for example, as Greenland or the Antarctic Continent.
IV.—On the Occurrence of Plants in the Skiddaw Slates
Authors: Nicholson Henry Alleyne
Published: May 2009

The occurrence of plant-remains in the Silurian and Cambrian rocks is a subject of great interest, but one which has not hitherto been sufficiently investigated. Many supposed plants have been described by Emmons, Hall, Billings, and Dawson, from the older Palæozoic rocks of North America, and little doubt can be entertained of the vegetable nature of some even of the most ancient of these. Many, however, as believed by Professor E. Forbes and Mr. Salter, are certainly referable to the tracks or burrows of marine animals. More recently the Cambrian rocks of Sweden have yielded to the researches of Torell and Linnarsson some remarkable impressions and casts of fossils, which are believed to be of a vegetable nature (Geol. Mag., September, Vol. VI., p. 393, Plates XI., XII., and XIII.). In Britain there is not, as far as I am aware, any instance of the occurrence of plant-remains in deposits of Lower Silurian age, as to the nature of which all authorities are agreed. The Oldhamia of the Cambrian rocks is believed by Mr. Salter to be a plant, but good authorities would place it either amongst the Polyzoa or Hydrozoa. The Cruziana semiplicata of the Lingula Flags has often been assigned to the Fucoids, but it is believed by Mr. Salter to be “the filled-up burrow of a marine worm” (Mem. Gaol. Survey, vol. iii., p. 248). Long ago Professor McCoy described from the Skiddaw slates (lowest Llandeilo) certain fossils which he believed to be fucoids (Quart. Journ. Geol. Soc., vol. iv., p. 223, and Pal. Foss., pl. i. A). After studying a large number of specimens, however, I have been compelled to come to the conclusion, held by Mr. Salter and Professor Harkness, that these fossils (viz. Palæochorda major, P. minor, and Chondrites acutangulus) are truly referable to the action of marine worms. Within the last few years, however, I have obtained from the Skiddaw Slates several fossils, which certainly do not admit of being explained in this manner, though I would not go so far as to assert that they are unquestionably plants. The age of the deposit in which they occur renders them, at any rate—whatever their true nature may be—of sufficient interest to merit a short description.
I.—The Volcanic History of Ireland
Authors: Hull Edward
Published: May 2009

I Have the pleasure of congratulating the Society on its prosperous condition after an existence of forty years, during which time it has numbered amongst its members men of the highest distinction in Science, and has been presided over by some of the most illustrious amongst the Cultivators of Geology. In looking over the names of the first officers of the Society in 1833, I am rejoiced to see those of the Provost of Trinity College, Sir E. Griffith, and Professor Apjohn, who are still amongst us; and to myself it could not have been otherwise than a matter of high gratification to have been elected to an office which has been filled by such eminent men as the former Presidents of this Society.
III.—Descriptions of New Fossils from the Devonian Formation of Canada
Authors: Nicholson H. Alleyne
Published: May 2009

Polyzoary calcareous, sessile, and encrusting, forming systems of small circular discs, the upper surfaces of which are marked with radiating ridges, upon which the cells are carried. Each disc is attached by its entire lower surface, slightly convex above, with a central non-poriferous space, round which a number of radiating poriferous ridges occupy an exterior slightly elevated zone. Cells forming a double series on each ridge, immersed, with rounded mouths, which are not elevated in any part of their circumference above the general surface.
I.—A Ramble Across the Mendip Hills
Authors: Woodward Horace B.
Published: May 2009

Many of those interested in geology are by time generally forbidden, and perhaps by inclination equally restricted from the investigation of details on a holiday trip. Nor need this be regretted, for the greatest pleasure in science is not always to be gained by the examination of details, but rather in the contemplation of results derived from such an examination.
IV.—The Devonian Question
Authors: Champernowne A.
Published: May 2009

In last month's Geological Magazine there is much (by three writers) that bears upon the Devonian Question, and I would now add a few words on the same subject, which is of the greatest interest to me.
II.—Restorations of Anchisaurus, Ceratosaurus, and Claosaurus
Authors: Marsh O. C.
Published: May 2009

A number of restorations of dinosaurian reptiles have been recently made by the writer, based upon American specimens which he has personally investigated. Reduced figures of three of these restorations have already appeared in this Magazine; namely, Brontosaurus and Stegosaurus from the Jurassic, and Triceratops from, the Cretaceous. Three others of interest are given in the present Number; Anchisaurus from the Triassic, Ceratosaurus from the Jurassic, and Claosaurus from the Cretaceous.
VI.—Notes on the Devonian Fishes of Campbelltown and Scaumenac Bay in Canada,—No. 3
Authors: Traquair R. H.
Published: May 2009

Mr. Whiteaves in his description of this species mentions that “in one specimen there are indications of what looks like a short break or separation between the anterior and posterior portions of the dorsal (or between the two dorsals if there were two, which is scarcely probable), but this break may be owing to an accidental and abnormal fracture of the fin rays at this point, for in other specimens the two portions appear to be continuous.” This break is, however, represented in all his figures, including the restored sketch given in his second paper in the Transactions of the Royal Society of Canada.
IV.—The True Horizon of the Mammoth, Etc.: Being a Reply to Mr. Mark Stirrup, F.G.S.
Authors: Howorth Henry H.
Published: May 2009

The very great importance of the issues involved if we are to make any definite progress in the study of the later deposits must be my excuse for this reply to Mr. Stirrup's letter. He says that the only available material for discussing the results of the expedition of Toll and Bunge to the Siberian islands is an abstract published by Schmidt some months ago. In this he is surely mistaken.
V.—Traces of a Great Post-Glacial Flood
Authors: Howorth H. H.
Published: May 2009

Having examined the various theories of the origin of the Loess, which have been current, and found them wanting, I would, with great deference, propose another which has not hitherto been suggested by any geologist, and which offers at least a probable solution of our untractable problem. In previous papers of this series, if we have not proved, as we think we have, that the evidence in favour of the Mammoth and his companions having been suddenly overwhelmed by a great diluvial movement is unanswerable, we claim to have at least shown a very strong á priori probability in favour of such a view.
I.—On a Series of Phyllopod Crustacean Shields from the Upper Devonian of the Eifel; and on one from the Wenlock Shale of S. Wales
Authors: Woodward Henry
Published: May 2009

Having in the autumn of 1878 arranged to make a geological excursion to the Eifel, with my friend Mr. John Edward Lee, F.S.A., F.G.S., of Torquay, we were so fortunate, when near Gerolstein, to meet Professor Dr. Ferdinand Roemer, of the University of Breslau, Silesia, who has made the Eifel region his special study, and who cordially joined our party, giving us the benefit of his great knowledge of this most interesting geological region.
VI.—Traces of a Great Post-Glacial Flood
Authors: Howorth H. H.
Published: May 2009

We must now turn to the theories which make these terraces to be deposited by the rivers when so charged with water that the whole valleys, from their solid foundations up to a height of at least 80 feet, were filled with water. These theories postulate no gigantic denudations extending over limitless ages, but accept the valley terraces as fluviatile deposits left along their own banks by the rivers when, by means of exceptional causes, they were, at one time, so flooded, that they actually reached the upper level terraces which in fact represent their old banks when so flooded. Two causes for such abnormal floods have been assigned. Mr. Tylor postulates a Pluvial period, characterized by most exceptional rainfall; while Mr. Belt urges that these floods were caused by the pounding back of the European rivers, and the consequent formation of a European lake by a great Atlantic glacier.
I.—On the Headon Beds of the Western Extremity of the Isle of Wight
Authors: Lucas A. H. S.
Published: May 2009

The recent answer to the recent questioning of the hitherto accepted correlations of the beds of the Lower Fluvio-Marine Tertiaries in the Isle of Wight and South Hants does not seem to be universally accepted as decisive. It is obviously impossible for foreign geologists to institute useful comparisons between British and foreign subdivisions so long as we in England are quite at variance on the stratigraphical and palæontological facts of the beds in question. Yet these conflicting readings are what we have to offer them at present.
V.—On the Classification of the European Rocks known as Permian and Trias
Authors: Irving A.
Published: May 2009

As this subject has been a matter for considerable debate during the past few years, and the British Committee of the International Geological Congress have had the matter under their consideration, it may be useful if I attempt to place before the readers of the Geological Magazine the results of the investigations of our sub-committee. As is well known, the term “Poikilitic” has been proposed in some quarters as a comprehensive name for both series, some writers advocating the view that they ought to be regarded as one “system,” as indeed they were of old under the name “New Red Sandstone.”
X.—On the Occurrence of a Glaucophane-bearing Rock in Anglesey
Authors: Blake J. F.
Published: May 2009

The occurrence of glaucophane has not, I believe, been previously noted in Great Britain, and as it is a mineral of some interest, my friend Mr. Teall has suggested that a separate notice of it should be given. It would otherwise be naturally described in the Report on the Microscopic Structure of Anglesey Rocks to be presented to the British Association at their forthcoming meeting.
II.—Contributions to the Geology of Africa
Authors: Raisin Catherine A.
Published: May 2009

The following notes have been drawn up from a study of specimens which were collected by G. F. Scott Elliot, Esq., during the earlier of two recent expeditions in Africa. He followed the Nile to somewhat beyond the second cataract, and brought back more than 130 examples of various rocks. The collection was sent to University College for examination, which I was allowed to undertake by the kindness of Professor Bonney, to whom I am further indebted for much help and advice on points of difficulty. A detailed description has been furnished to Mr. Scott Elliot to be included in the account of his journey, which it is to be hoped will be published before long. It may, however, be useful to have a short summary of the chief points of geological interest for general reference in an easily accessible publication.
III.—A Word on Geological Hypothesis
Authors: Posnett H. Macaulay
Published: May 2009

“Scientific men,” said Professor Thomas H. Huxley, “get an awkward habit—no, I won't call it that, for it is a valuable habit—of believing nothing unless there is evidence for it; and they have a way of looking upon belief which is not based upon evidence, not only as illogical, but as immoral.”
II.—Notes on the Geology and Palæontology of Argentina
Authors: Ameghino Florentino
Published: May 2009

Until a few years ago it was believed that the Territory of Patagonia was of an extremely simple and uniform geological structure; it was supposed that from the Colorado to the Straits of Magellan, and from the Atlantic to the base of the foot-hills of the Andes, it was constituted exclusively by the marine Patagonian Formation, on the age of which the most varied opinions were expressed, although all agreed in referring it to the Tertiary series. This uniformity was interrupted only at intervals by great sheets of basalt which appeared sometimes at the surface, sometimes below the boulder-deposit.
III.—Blind Trilobites
Authors: Reed F. R. Cowper
Published: May 2009

We now come to the second o rder of the Trilobita, which Beecher (loc. cit.) calls the Opisthoparia. In common with the third order, the Proparia, compound paired eyes are usually present, and these are invariably situated on the free cheeks, which form part of the dorsal surface of the head-shield.
I.—Note on a Devonian Cælacanth Fish
Authors: Woodward A. Smith
Published: May 2009

Students of Palæozoic fishes are indebted to Professor A. von Koenen, of Gottingen, for two interesting memoirs on the fragmentary fish-remains of the North German Devonian formations. Owing to their incomplete character, however, the Professor is only able to suggest a provisional interpretation of most of the specimens, and the determination of their true nature must be left for future discoveries.
VI.—Blind Trilobites
Authors: Reed F. R. Cowper
Published: May 2009

The majority of fossiliferous beds in the Cambrian are of anargillaceous nature, and limestones are comparatively rare, but weneed not here enter into a discussion as to the causes of their rarity.When, however, we come to the Ordovician, we find calcareous bedsmuch developed, and since we find in them, as well as in the slatesand shales, these blind genera, and as far as we know not lessabundantly, it appears as if the physical conditions of sedimentationhad but little to do with the existence and perpetuation of theseforms.
II.—Notes on Altered Igneous Rocks of Tintagel, North Cornwall
Authors: Hutchings W. Maynard
Published: May 2009

In the autumn of 1887, during a stay in North Cornwall, I paid a hasty visit to Tintagel, and took away a few specimens of rocks, without, however, having time or opportunity to examine more than very superficially into their field-relationships.
VII.—On some Physical Changes in the Earth's Crust
Authors: Ricketts Charles
Published: May 2009

Subterranean landslips differ from landslips occurring in cliffs along the coast, and in escarpments elsewhere, in that, a fissure having been formed and its sides become separated (Figs. 2 and 3 a), so that they are without support along the line of division, it may happen that by the giving way of some soft or unconsolidated stratum (b), at any depth, from a few feet only, down to the molten nucleus, wedge-shaped masses (c) extending parallel to the fissure would break off (d) and slipping down strike against the opposite wall (Fig. 3e) and thus fill up the fissure.
VIII.—On a Cœluroid Dinosaur from the Wealden
Authors: Lydekker R.
Published: May 2009

In going through the remains of Chelonia preserved in the British Museum I came across two vertebræ from the Wealden of the Isle of Wight, which had been inadvertently included in that series. These specimens (B.M. No. R. 901) formed part of the collection of the late Rev. Mr. Fox, and clearly indicate a small Dinosaur allied to the genus Cœlurus.
II.—On Statical and Dynamical Metamorphism
Authors: Judd John W.
Published: May 2009

It has long been recognized by geologists that rock-masses which have undergone movement, and have thereby been subjected to internal stresses, exhibit, as the consequence of the action upon them of such mechanical forces, unmistakeable evidences of having been greatly modified, alike in their mineralogical and in their structural characters. That the most complete and striking examples of such changes are to be found in the rock-masses which constitute mountain-chains—rock-masses which have actually been made to “flow,” and in so doing have been subjected to shearing movements of the most intense character—was clearly pointed out by Scrope, Darwin, Sharpe, Naumann, and Dana; all of whom referred the foliated structure exhibited by such rock-masses to this cause.
I.—Subaërial Deposits of the Arid Region of North America
Authors: Russell Israel C.
Published: May 2009

The subaërial deposits now accumulating in the arid portion of the United States may be divided into four classes: 1, Eolian Sands; 2, Talus Slopes; 3, Alluvial Cones; and 4, Calcareous Clays to which no specific name has been applied, but which, for reasons stated below, will be called “adobe” in this paper.
III.—The Marsupites Chalk of Brighton
Authors: Brydone R. M.
Published: May 2009

A description on modern lines of the Brighton chalk below the (old) zone of Actinocamax quadratus is to be found in Dr. Rowe's “Coast Sections”, pt. i, p. 346. The principal points that he makes are that between Ovingdean Pumping Station and Black Rock the cliffs display below the (old) zone of A. quadratus a thickness of 58 feet of chalk, the whole of which, he assigns to his zone of Marsupites, and further to his Marsupites band as Uintacrinus was not found in it, but he notes that Uintacrinus has been found on the reefs. These points have, as far as I know, stood unchallenged hitherto, but I am unable to reconcile them with my experience.
IV.—Note on a Chalk Ammonite, probably referable to Ammonites Ramsayanus, Sharpe
Authors: Crick G. C.
Published: May 2009

In 1856 Sharpe founded the species Ammonites Ramsayanus upon a single deformed specimen (in the collection of J. Wiest, Esq.) that was obtained from the “Chalk with silicious grains, at Chardstock, Somersetshire.”
I.—The Earliest Traces of Man
Authors: Howorth Henry H.
Published: May 2009

The origin of Man remains an unsolved problem. In spite of very keen and anxious researches, extending over many years, we are still without a real clue to the difficulty. Whence and how and when he came we do not know, and we had better say so.
VI.—On the British Earthquakes of 1900
Authors: Davison Charles
Published: May 2009

During the past year there were only two undoubted earth-quakes in this country. Some may have occurred in Glen Garry, one of our most sensitive regions; but the construction of a new railway through the valley renders it difficult to identify true earthquakes with certainty. The total number of British earth-quakes during the last twelve years thus amounts to 116, of which 46 had epicentres in England and Wales and 70 in Scotland, 42 of the latter number being confined, or almost confined, to Glen Garry.
I.—Eminent Living Geologists
Authors: Bonney T. G.
Published: May 2009

Thomas George Bonney was born July 27th, 1833, at Rugeley, Staffordshire. His family is of Huguenot origin, and thus affords yet another instance of the remarkable intellectual enrichment of our country which resulted from the religious persecutions in France. His father, the Rev. Thomas Bonney, son of the Rev. George Bonney, vicar of Sandon, and sometime Fellow of Jesus College, Cambridge, was a man of wide and varied interests, and a hard worker, in spite of feeble health; he was master of the Grammar School, Rugeley, and for many years ‘perpetual curate’ of Pipe Ridware, a very small parish about five miles from Rugeley. The church was rebuilt through his efforts, and he took great interest in primary education, acting for some time informally as Inspector of Schools in the Diocese. He married a daughter of Edward Smith, a Staffordshire man of independent means, and died in 1853, leaving a widow and ten children, of whom Professor Bonney, then just entering upon his second year at Cambridge, was the eldest. The family inherited some property, but the income it afforded was small for the education of so many.
IV.—On the Limburgite from near Sasbach
Authors: Bonney Canon T. G.
Published: May 2009

So much confusion has existed on the subject of limburgite, that, although it has now been partly dissipated, a record of my own investigations may be of use, at any rate to English petrologists. The rock has been classed by some with the peridotites. From these it is separated by Rosenbusch, who in his latest work places it in a subgroup with the augitites in proximity to the basalts. Zirkel uses limburgite as a synonym for magma-basalt. F. Graeff implies relationship with the nepheline-basalts. Harker's remarks suggest similar conclusions, as do those of Cole, though his opening words are perhaps slightly misleading. All, however, lay so much stress upon the absence of felspar, by giving such definitions as “Limburgite und Augitite sind die felspathfreien Entglieder der Gesteinreihe Trachydolerit, Tephrit,” etc., or “Frei von Feldspar und Felspathoiden ist der Limburgit,” and in some cases by reference to the peridotites, that students may readily overlook the fact that this rock is only free from felspar in the same sense as tachylite or many pitchstones and obsidians.
VI.—Photography in Geology
Authors: Woodward Henry
Published: May 2009

Photography has now become so invaluable an accessory to every branch of science, that it is not surprising to find it has proved indispensable alike to the geologist and the palæontologist. One has but to turn back over the four decades of this Magazine and compare the number and quality of the illustrations, in the earlier with the later years, in order to realize the great advances that have been made by the application of photography both to process-plates and to illustrations in the text (especially in the last quarter of a century), which has so enriched and enhanced the value and interest of this and other scientific journals. That good half-tone process-blocks can be made from photographs of any geological subject taken in the field, is now well established; nevertheless, two points are absolutely essential to their success: (1) the photograph must be particularly clear and well-defined in its details; (2) the block, however good, may easily be rendered worthless by bad or careless printing; moreover, it must be reproduced upon paper with a finely finished surface, although it need not necessarily be the highly glazed kind (heavily loaded with kaolin) now so much in vogue for the illustrated Monthlies.
III.—On the Rate of Increase of Underground Temperature
Authors: Sollas W. J.
Published: May 2009

In the 22nd Report of the Committee appointed to investigate the rate of increase of underground temperature, read this year before the British Association in Glasgow, some remarks previously made by me are animadverted upon; and as the Secretary, Professor Everett, has invited me to discuss the matter with him, I take the opportunity of entering somewhat more fully into the question of conductivity than has hitherto seemed necessary. We read in the Report “… . in view of the fact that the President of Section C last year characterised the variation in the British Isles ‘from 1° in 34 feet to 1° in 92 feet’ as ‘a surprising divergence of extremes from the mean,’ it is well to emphasise the connection between gradient and conductivity. If there is anything like uniformity in the annual escape of heat from the earth at different places, there must necessarily be large differences in geothermic gradients, since the rate of escape is jointly proportional to the gradient and the conductivity.”
II.—Woodwardian Museum Notes: Salter's Undescribed Species. VIII.
Authors: Reed F. R. Cowper
Published: May 2009

There is only the one poorly preserved and imperfect specimen in the Woodwardian Museum on which Salter founded this species. It comes from the Wenlock Limestone of Dudley and belongs to the Fletcher Collection. Salter says of it (a 827): “Strongly costated and marked with lines of growth which decussate the ribs. Twice the size of the common Ludlow species.” The material is so poor that the specific description must necessarily be incomplete.
III.—The Ventral Integument of Trilobites
Authors: Beecher Charles E.
Published: May 2009

In previous papers by the writer on the structure and appendages of Triarthrus, no attempt has been made to describe or illustrate the character of the ventral integument, especially in the sternal or axial region. The specimens hitherto described were prepared to show details of the appendages, and though portions of the ventral membrane were exposed in many individuals, the subject was not considered of sufficient moment to warrant a distinct study, particularly as no characters were observed in the cuticle that had not been previously seen in more or less perfection by Walcott in the genera Ceraurus and Calymene. A recent discovery by Jaekel, however, necessitates the separate consideration of this structure. This necessity arises from the fact that a positive addition to the knowledge of the trilobite anatomy may be deduced, although, as will be shown, Jaekel was apparently entirely misled in his interpretation of the nature of his discovery.
VI.—Echinocaris Willdbornei (Jones & Woodward) and Echinocaris Sloliensis, n.sp.
Authors: Partridge E. M.
Published: May 2009

During the last year the Marwood Beds of Sloley Quarry, near Barnstaple, have yielded some additional specimens of Echinocaris, which have afforded material for the present note. The specimens have all been found in the fine micaceous shaly beds, six to eight feet thick, on the north side of the quarry, below the massive sandstones, and above the shallow-water bed containing plant-remains, rain-prints, worm-tracks, etc. The same shaly beds contain Lingula squamiformis in abundance; other bivalves are less frequent. They have now yielded as many as twelve specimens of Echinocaris.
VII.—On some Examples of Marine and Subaerial Erosion
Authors: Monckton Horace Woollaston
Published: May 2009

On the excursion of the Geologists Association to Gower last Easter our Director, Mr. R. H. Tiddeman, showed us a series of examples of the celebrated raised beach, and a good deal of discussion arose as to its relation to the other recent deposits of the district. Into those questions I do not propose to enter on this occasion, but will accept, what all admitted, viz., that the beach is an old sea beach, that the platform upon which it rests is the work of the waves, and that it has been raised to its present position by earth-movement.
II.—Woodwardian Museum Notes. On a Specimen of Cyclopteris (Brongniart.)
Authors: Seward Albert C.
Published: May 2009

The specimen of which I give below a brief description is of some interest as adding to the store of facts which may help us in the elucidation of the obscure genus Cyclopteris. So far as I know such large Cyclopteris leaves have not been previously figured attached to a rachis.
IV.—Notes on the Sauropterygia of the Oxford and Kimeridge Clays, mainly based on the Collection of Mr. Leeds at Eyebury
Authors: Lydekker R.
Published: May 2009

I Presume that most English students of Mesozoic Reptiles are acquainted, at least by report, with the magnificent collection of the remains of Sauropterygians and other Saurians from the Oxford Clay of Northamptonshire in the possession of Mr. A. N. Leeds, of Eyebury, near Peterborough. Those, however, who have not had the good fortune to see this unrivalled collection, can have no idea of its richness, or of the light it throws on the organization and affinities of the Sauropterygians of the later Jurassic seas.
IV.—The Geological Age of the Earth
Authors: Joly J.
Published: May 2009

The able review of my paper on the Geological Age of the Earth which appears in the March number of this Magazine (p. 124), from the pen of the Rev. O. Fisher, raises again questions of such wide interest that some further remarks, referring principally to the criticism of the distinguished writer of the review, and also to criticisms which I have received from others and which are probably in the minds of many who have considered the matter, may not be out of place.
II.—On a Granophyre Dyke intrusive in the Gabbro of Ardnamurchan, Scotland
Authors: Busz K.
Published: May 2009

Last year, while on an excursion to Scotland, I visited the Ardnamurchan peninsula, which, as is well known, consists to a great extent of rocks belonging to the gabbro family. On the road leading from the little village of Kilhoan, opposite the Isle of Mull, on the north coast, a small quarry has been opened for road-metal, which shows an exquisite section of a granophyre dyke intrusive in a dark and almost black fine-grained rock, which the microscopic examination proved to be a gabbro. This is, therefore, a similar occurrence to that of Barnavave, Carlingford, Ireland, which has been admirably described by Professor Sollas, and also that of Strath in the Isle of Skye, of which Mr. Harker has given us a detailed account. As occurrences of this kind seem to be rather rare and, as far as I am aware, hitherto not known from Ardnamurchan, I may be excused for calling your attention to the following short description of these rocks, although there is but little to be added to the results attained by the skilful researches of the above-mentioned authors, and it only shows again that on Ardnamurchan we are to expect very nearly the same geological phenomena as in the adjacent islands, in particular in Skye and Rum.
VII.—Note on Zieten's Type-Specimens of Ammonites polygonius and Ammonites discoides
Authors: Crick G. C.
Published: May 2009

The presence of Zieten's type-specimen of Ammonites calcar in the British Museum (Natural History) among some fossils which were bought of Dr. Bruckmann naturally suggested an examination of the other fossil Cephalopoda obtained from the same source, in the hope of finding other type-specimens. Thus far, the result of this examination has been the discovery of two more of Zieten's types; these are the type-specimens of (i) Ammonites polygonius and (ii) Ammonites discoides.
V.—Twenty Years' Work at the Younger Red Rocks
Authors: Irving A.
Published: May 2009

Having made my first acquaintance with that puzzling series of strata which bridges over the vast interval of geologic time between the Carboniferous and the Jurassic in the Nottingham district during a residence of eight years in the good old town (see Proc. Geol. Assoc. vol. iv.; also Quart. Journ. Geol. Soc, November, 1875), the meeting at Nottingham seems a fitting occasion for summarizing the results of further work in connection with those rocks, as opportunities have offered, during the last twenty years.
I.—On the Discovery of Cyclosphæroma in the Porbeck Beds of Aylesbury
Authors: Woodward Henry
Published: May 2009

In December, 1890, I had the good fortune to describe a new Sphasromid discovered by Mr. Thomas Jesson, B.A., F.G.S., in the Great Oolite of Northampton, which I named Cyclosphæroma trilobatum (see Geol. Mag., 1890, Dec. III, Vol. VII, pp. 529–533, PL XV). This specimen, which is redrawn on the accompanying PI. XIV (Fig- 1), is remarkable for its rounded outline, which induced me to apply to it the name Cyclospharoma.

Great was my joy when, in March last, I received from my friend Mr. E. J. Garwood, M.A., F.G.S., another Jurassic Isopod, of which both the intaglio and the, relievo had been obtained by him in the Purbeck beds near Aylesbury. This remarkably beautiful Crustacean proves to be a more perfectly preserved example of the same Sphseromid which I had described in 1890, from the Great Oolite of Northampton, and it needs but to compare Figs. 1 and 2 upon our Plate to perceive that in Fig. 1 the thoracic segments are much compressed together posteriorly, and that the hinder part of the telson is wanting; otherwise the resemblance between it and the newly-found and much more perfect example from the Purbeck beds of Aylesbury (PI. XIV, Fig. 2) is unmistakable.

A reference to the diagnosis of the genus (as given in Geol. Mag., 1890, p. 530) will show that it must now be amended in consequence of the discovery of the more complete specimen by Mr. Garwood.
V.— On a Jurassic Lamellibranch and some other associated Fossils from the Sarawak River Limestones of Borneo; with a Sketch of the Mesozoio Fauna of that Island
Authors: Newton R. Bullen
Published: May 2009

Certain deposits in the neighbourhood of the Seberuang Eiver, a tributary of the Kapuas in Western Borneo, were described by E. Everwijn in 1854 as containing numerous so-called “Nummulites.” Similar organisms were obtained at a later date from the same district by Dr. F. Schneider, which were examined by Dr. K. Von Fritsch and proved to belong to the genus Patellina. Two new forms were described and figured under the names of P. scutum and P. Irochus, whilst the occurrence of Patellina itself suggested to Von Fritsch. the probability of the beds in question being of Cretaceous age.
IV.—Essays in Theoretical Geology
Authors: Oldham R. D.
Published: May 2009

I have already shown that the northern boundary of the Indo-Gangetic alluvium is a structural one, and that the rock area immediately to the north of it has been elevated, while the nature of the boundary on the south, the deep imbayments of the alluvium, the gentle manner in which the older rocks slip under it, and the inliers, alike show that, on the south, the alluvium has gradually encroached on the rock area by the subsidence of the latter.
IV.—Vulcano and Stromboli
Authors: Fulcher L. W.
Published: May 2009

Since the excellent and interesting series of papers on the history and description of these celebrated volcanoes by Professor Judd, which appeared in the Geological Magazine for 1875, there is, as far as I know, no connected record of their condition. The islands, though affording such excellent opportunities for the study of volcanic action, are but rarely visited by geologists; but having had the opportunity of examining them myself in the autumn of last year as a member of the party arranged by Dr. Johnston-Lavis under the auspices of the Geologists' Association, I thought it would be well, whilst recording my own observations, to prefix a brief account of the volcanoes since the above-mentioned date. The information, on which the following brief sketch is based, has been derived partly from a series of papers by Prof. Mercalli, on notes derived by correspondence with Sig. Pincone, the former manager of the lately existing Chemical Works at Vulcano, who now resides at Lipari, and partly from papers in various periodicals to which I will refer as occasion requires.
VII.—Notes on the Altered Coniston Flags at Shap
Authors: Hutchings W. Maynard
Published: May 2009

The alteration undergone by the Coniston Flags, owing to the intrusion of the Shap granite, has been well and fully described by Messrs. Harker and Marr in their most able and interesting paper, read before the Geological Society in the spring of this year, “The Shap Granite and the Associated Igneous and Metamorphic Rocks” (Q.J.G.S. vol. xlvii. 1891).

I have worked a great deal, microscopically, on the rocks of this district, both before and since the publication of the results of Harker and Marr, and this work has enabled me in a special manner to appreciate the quality and value of their investigations in this complicated and interesting region. I was so fortunate, two summers ago as to spend some time at Shap with Mr. Marr, who most kindly assisted me to understand some of the problems involved, and pointed out to me the places where specimens of special interest could be collected.
III.—Note on the Denudation and Elevation of the Weald
Authors: Monckton Horace W.
Published: May 2009

It is I think, practically admitted that the present condition of the Weald is the result, firstly of marine, and secondly of subaerial denudation. A plain of marine denudation was first formed, and the valleys were carved out by subaerial action.
IV.—Tertiary and Post-tertiary Stratigraphy
Authors: Struthers Thos R.
Published: May 2009

As a basis for the following observations on the classification of Tertiary and Post-tertiary strata, we submit a comparative view of the nomenclature adopted by various authors.
VIII.—The Lower Paleozoic Rocks Near Settle
Authors: Marr J. E.
Published: May 2009

The rocks of this area have been previously described by Professor Hughes (Geol. Mag. Vol. IV.), and some notes upon the same were subsequently submitted by myself to the British Association at Yorkin1881, and published in the Proceedings of the Yorkshire Geological and Polytechnic Society (Proc. Y. G. & P. S. N.S. vol. vii.). Further work was carried on this year, incompany with a party of Cambridge geologists, under the guidance of Prof. Hughes, and I have to thank him and them for much information, and for the opportunity of examining many specimens.
VIII.—On the Secular Straining of the Earth. I.
Authors: Davison Charles
Published: May 2009

As early as the times of Descrates (1668) and Newton (1681), the “ settling and shrinking of the whole globe after the upper regions or surface began to be hard,”2 was held a sufficient cause for the formation of mountain-chains. Following the growth of our knowledge of mountain-structure, the contraction theory has been rediscovered several times in the present century. It has been worked out in great detail by Élie de Beaumont, Prevost, Delabeche and others; but, above all, by J. D. Dana, the real founder of the theory, in an admirable series of papers extending over the last forty-two years.

Leaving its details out of account, the fundamental idea in the contraction theory may be stated as follows: The whole earth was originally at a high temperature throughout, its present distribution of temperature being the result of cooling since the initial epoch.