mM CR WHITNEY LIBRARY, HARVARD UNIVERSITY. WM Kellie OR J. SDS W ane aa, Sturgis Hooper Professor IN THE MUSEUM OF COMPARATIVE ZOOLOGY - « é »4 ere 2D> ID D2 DD YD» DD» >> 2 al 2» _» S>-D Dp »> SD >) >> >> SDD DIED) >» > aw oP 22D 2D? _ D> 5D DD Dp DD D> Dp ~ ? * > 22> E> >P > D»”Dd DD> D»»x» DYDD yD? =») >» JP?) ID ID Dow P»”»D DDd>2 DW D DID» Dy» _Dyv>» a> See D> >> D!) > D2. DD DD wp Dw > > 30 3 > = < PLDI PP >> 22 aps IP? SY SIP 7 = Ee en ai at >» > 2 2» 2» > 2 a > >>> > >? > yD . GEOLOGICAL SCIENCES LIBRARY a ai ir\ : : AIF AA al i An Ae 2 ~) 2 3 ies ae al Ain A aa i ~ fr \j ~\ Nf \ >>) ‘ i Mie tai ‘A, ry i eae Cee ha) y esan hg Ar THE GEOLOGICAL MAGAZINE NEW SERIES. DECADE II. VOL. VIII. JANUARY—DECEMBER. 1881. THE GEOLOGICAL: MAGAZINE: OR, Monthly Journal of Geology: WITH WHICH IS INCORPORATED Pla), Gol Ot OGel Ss W27 NOS. CXCIX. TO CCX. EDITED BY HENRY WOODWARD, LL.D., F.R.S., F.G.8., F.Z.S., F.R.MS., OF THE BRITISH MUSEUM OF NATURAL HISTORY; MEMBER OF THE LYCEUM OF NATURAL HISTORY, NEW YORK; AND OF THE AMERICAN PHILOSOPHICAL SOCIETY, PHILADELPHIA; HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL SOCIETY; OF THE GEOLOGISTS’ ASSOCIATION, LONDON; OF THE GEOLOGICAL SOCIETIES OF EDINBURGH, GLASGOW, AND NORWICH ; CORRESPOND- ING MEMBER OF THE GEOLOGICAL SOCIETY OF BELGIUM; OF THE IMPERIAL SOCIETY OF NATURAL HISTORY OF MOSCOW; OF THE NATURAL HISTORY SOCIETY OF MONTREAL; AND OF THE MALACO- LOGICAL SOCIETY OF BELGIUM. ASSISTED BY PROFESSOR JOHN MORRIS, M.A., F.G.S., &c., &c., AND ROBERT ETHERIDGE, F.R.S.L. & E., F.G.S., &e. PRESIDENT OF THE GEOLOGICAL SOCIETY OF LONDON ; OF THE BRITISH MUSEUM OF NATURAL HISTORY. NEW SERIES. DECADE II. VOL. VIII. JANUARY—DECEMBRER, 1881. LONDON: TRUBNER & Co. 57 anp 59, LUDGATE HILL. F. SAVY, 77, BOULEVART ST.-GERMAIN, PARIS. Se ussite HERTFORD: PRINTED BY STEPHEN AUSTIN AND SONS. LIST OF PLATES. ~ I. Remains of Ornithocheirus (Seeley), Upper Greensand, Cambridge... cE elle EscharoideHorms ot Oolitic Polyzoay | he var. Beyrichia Kledent (2), M‘C. Cy there, sp. Lagena. Conodonts. Spicules. Pearls (?). to. Gleedon Hill, Much-Wenlock. Beyrichia tuberculata, Klozden. (Fine old specimen.) Conodonts. Pearls (?). 11. Railway-cutting near Much-Wenlock. Primttia, sp. (Long form, like that in No. 7.) Beyrichia Kledenz, M‘C., var. intermedia, J. ”? sp. Thlipsura tuberosa, J. & H. Cy there, sp. Sptrorbis. 1z, Eskam-Engham, near Mayhill. Lhlipsura, sp. (Very faint end-mark.) 13. Woolhope. Lsochilina (or Leperdttia ?), sp. Primitia excavata, J. & H. ne sp. (Reticulate.) 9 sp. (Oval.) LE chmina cuspidata, J. & H. Beyrichia tubercudata (?) Kleeden. (Old individual.) 35 Kledent, M‘C. ap i var. tuberculata, Salter. ae op var. ? ? i sp.: Cytherella, sp.? Thlipsura, sp.? Lagena. Pearls (?). 14. Dormington Wood, Benthall Edge. Beyrichia Kledenz (?), M‘C. Thlipsura corpulenta, J. & H. Lagena. Spivorbis. Spicules. Pearls (?). I5. Stocksay. Primitia variolata (?), J.& H. (Crushed specimen.) Beyrichia tuberculata, Kloeden. (Cast.) Cytherella, sp. Cythere, 2 sp. (Resembling C. egualis, J. & K. MS., and C. obtusa, J.& K. MS, from the Carboniferous Formations.) 16. Malvern Tunnel, West End. a. Red Shale. Primitia Remertana (?), J. & H. Thlipsura corpulenta, J. & H. Cythere,2sp. (Like those in No. 15.) Spicules. 5. Blue Shale. Thlipsura corpulenta, J. & H. Cythere, sp. Spicules. T. Mellard Reade—Oceanic Islands. “tT Or 17. Craven Arms, rotten limestone near the. Spzcules (3- and 6-rayed). Conodonts. Pearls (?). The Zagene (mounted on one slide) from Lincoln Hill, the Railway-cutting at Ironbridge, Dormington, Woolhope, and Benthall Edge, comprise: Lagena vulgaris, Williamson, var. Zevzs, Montagu (with tubuliferous neck). 33 >, bs », clavata, D’Orb. 5 a 35 », sulcata, Walker and Jacob. The close correspondence of the Recent with these Silurian forms is very noteworthy. The presence, also, of some Entomostracan species apparently identical with Carboniferous forms is to be noted as an additional example of recurrence (like the Silurian Beyrichia intermedia in the Carboniferous Limestone of Russia). The presence, also, in these old deposits of Hxtomostraca indistinguishable, as to valves, from recent genera, should not be lost sight of. I submitted Mr. Smith’s Collection of Upper-Silurian Ento- mostraca to my friend Mr. J. W. Kirkby, and he favoured ine with the following remarks :— “ With this I return you Mr. Smith’s Silurian Entomostraca, which I thank you for the sight of. They are the best Silurian specimens that I have seen. Some of the Cythere-like forms appear to come pretty near Carboniferous species, as you pointed out to me. A set on one slide can scarcely be distinguished from Miinster’s Cythere bilobata, and on other slides there are specimens that I suppose we should have named C. equalis, J. and K., and C. obtusa, J. and K., had they been found in Carboniferous strata.” V.—Oceranic Isnanps. By T. Metuarp Reapsz, C.H., F.G.S. HE Pacific and Atlantic Oceans far from the continental masses of land are studded with islands, which from their being solely voleanic and of an age going back no further than the Tertiary period, are considered to lend great support to the hypothesis of the permanence of the great oceans and continents. Those who hold these views question the right of New Zealand to be considered a truly oceanic island, though on what grounds has never been quite intelligible to me. Waiving this objection for the purpose of argu- ment, | propose to discuss the bearings of the facts, as formulated by those who believe in the “approximate” immutability of land and sea. But before this can be done it will be necessary to consider the vertical limits within which Dr. Darwin’s generalization, that the ‘‘ reat oceans are still mainly areas of subsidence, the great archi- pelagoes still areas of oscillation of level, and the continents areas of elevation,” ' could have acted. An approximate calculation tells me that had one-half of the ocean floor subsided 1500 feet since Cambrian times, the period Dr. Darwin adopts for the commence- ment of this state of things, the then land, if it possessed the 1 Origin of Species, 4th edit. p. 373. 76 T. Mellard Reade—Oceanic Islands. present contours of our continents, would have been submerged to about the 700 feet contour. It is impossible at present to calcu- late with exactness to what extent this would reduce its surface, but probably one-half. If, on the other hand, the land had risen since Cambrian times 1500 feet, it is evident there must have been very little of it to commence with. Therefore, if there has been a preponderance of depression in the oceans and of elevation in the land since Cambrian times, it has acted within very narrow limits, or there would not have existed land enough to provide sediment for the construction of the enormous thickness and extent of the later sedimentary rocks we know of, to say nothing of those which under my hypothesis must be admitted to extend more or less under the sea-bed. The volcanic oceanic islands are mostly based upon submarine plateaux, one of which in the Pacific extends from Cape Horn ina north-westerly direction to Tahiti, a distance of some 80 degrees of longitude and 30 degrees of latitude, at a depth of about 1000 fathoms.! It is conceivable, if these plateaux were areas of oscilla- tion of level, that the vertical limits of movement may have been too small to have produced by that means continental islands, and it is also conceivable, though not probable, that the plateaux may now all be at the downward limit of oscillation.? Now comes my argument. The lapse of time between the Cambrian and Tertiary periods was vastly greater than that between the commencement of the Tertiary and the present time. I will not presume to say how much more, because authorities differ, but Dana puts it down, as nearly as I can interpret him, at about fifteen times as great. Are we then to assume that during all this vast interval of time, and over an immense extent of the ocean floor, the volcanic forces of the earth, which some physicists maintain have been gradually dying out, lay dormant, so that no volcanic island or land was built up from even a depth of 1000 fathoms—not two-thirds the height of Etna? And are we to go further, and say that this stable state of equilibrium was suddenly disturbed by voleanic eruptions during and since the Tertiary period, by which what are called the Oceanic islands were created? J think neither physicists nor geologists will admit this to be probable without very strong evidence, which has yet to be given. It may be said in reply that such Palzeozoic or Secondary voleanic islands may have existed and become since destroyed by atmospheric or oceanic waste; but this admitted, cuts the ground from under the argument, as the same forces would also have destroyed sedimentary rocks, the absence of which is accounted a proof of the permanence of the oceans and continents. Properly considered, then, the argument drawn from the volcanic or non-sedimentary nature of the so-called oceanic islands is, as usual with negative evidence, not very much to be relied on. Nay, 1 Thalassa, pp. 21-2. 2 This is disproved by Dr. Darwin’s own observations. 3 Manual of Geology, 2nd edit. p. 586. Thomas Stock—Rhizodus at Wardie. We to me it seems rather to point to the fact that the condition of things oceanic since the commencement of the Tertiary period differed and still differs from that which existed in earlier times, and is therefore, looking at it in this light, rather against than for the hypothesis that the oceans and continents occupy permanent positions on the earth’s surface. The distinguished author of the “ Origin of Species,” so fertile in suggestions, yet so fair in judgment, while upholding in a letter to the writer his published views! on the subject, considers, as we all must, that it is full of perplexities, and that the more it is discussed the better. VI.—On tHE Discovery OF A NEARLY ENTIRE RaIzODUS IN THE WARDIE SHALES. By Tuomas Srocx, Esq., Natural History Department, Museum of Science and Art, Edinburgh. (Read before the Edinburgh Geological Society, 16th December, 1880.) HE fact of the occurrence of Rhizodus at Wardie has been known for a good many years. It appears as an addendum to a list of fossils from that locality published* in 1861 by the Geological Survey of Scotland. The specimens hitherto collected, however, have been the merest fragments, consisting principally of detached scales. Almost the first fossil obtained by the writer from Wardie was a badly-preserved fragment of the jaw of Rhizodus containing teeth. Since then a few fragments have occurred refer- able to the same genus. From the fact that these were invariably found along a particular part of the beach, the suspicion was gradually awakened that they had been derived from a common source. This suspicion was confirmed by the discovery of the remarkable specimen which is the subject of this notice. It was found lying in the direction of the strike of the beds, its head seawards, its tail to the shore. The greater part of it was buried under from six inches to a foot of shale. The end of the tail and the anterior portion of the head had been bared by the waves, and though the tail remains almost intact, the head has suffered a good deal from the erosion of the sea. The rest of the fish is preserved. As the bed in which it was entombed is accessible only at very low-water, considerable difficulty was experienced in getting the specimen away; but, thanks to the help of Mr. Macpherson of Trinity, this was effected, and a noble fish has been saved to science. It is undesirable at present to say much about the new facts which this specimen reveals. Much may be made out as to the shape of the fish and the position of the fins; but it would be unwise to give forth statements involving facts of great structural importance until these can be corroborated by examination of the fish, after it 1 T am indebted to Mr. Topley for calling my attention (Groz. Mac. Dec. 1880, p. 573) to Mr. Darwin’s views. * The Geology of the Neighbourhood of Edinburgh, London, 1861. 78 Thomas Stockh—Rhizodus at Wardie. has been properly developed and displayed. It will be enough to say that it appears to be in a good state of preservation; that it is nine feet in length; and that it occurs in the form of an immense flat nodule. A few detached scales were found in nodules beside it; but beyond this and the injury the head has received from the sea, there has been no disintegration of importance. The remains of Rhizodus hitherto obtained have been of a very fragmentary nature. Ure! figured a part of a mandible with teeth. Dr. Hibbert’s* material, though more abundant, was very little better. M‘Coy® says that its general form is unknown. Mr. John Yonng, F.G.S.,* noticing its occurrence near Glasgow, says, ‘‘No large fragments of either the internal skeleton or the outer covering of scales, have yet been found in this locality. In the KE. of Scotland, R. Hibberti is very common in the Burdiehouse Limestone, and in one or two localities in the Fifeshire Coal-field ; but no perfect examples have yet been found, so that its general form is unknown.” Professor Young® remarks that “no fragments have yet been found from which the shape of the body or the structure of the head can be determined.” Professor Miall,*® in a clear and able paper, describes “a large and tolerably perfect skull,” and observes, ‘‘ Much yet remains to be known of the Carboniferous genus Rhizodus, of which only the teeth, scales, pectoral arch, jugular plates, and mandible have hitherto been identified.” American authors? have referred fragments to Rhizodus, but they do not seem to have been so fortunate as ourselves with this fish. The specimens in the Edinburgh Museum of Science and Art, many of them very fine, are all fragmentary, so that there is abundant warrant for saying that the Wardie 2hizodus is the first yet obtained in a nearly perfect state of preservation. It would be no exaggeration to affirm that it is the largest nearly entire fish which rocks of Carboniferous age have yet yielded. Appended are a few localities in the Calciferous Sandstone Series of the district where Rhizodus remains have been discovered: Brick- works at Straiton; Oakbank, near Mid Calder; Burdiehouse ; Arthur’s Seat; Gowan’s new quarry near Juniper Green, on the horizon of the Wardie Shales. It was found by Mr. Henderson at this locality in sandstone, an unusual circumstance. ' The History of Rutherglen and East Kilbride, Glasgow, 1793, pl. xix. fig. 4. 2 Trans. Royal Soc. of Kdinb. vol. xiii. 1836, p. 169, e¢ seq. ° Brit. Pal. Fossils, 1855, p. 612. 4 Trans. Geol. Soc. Glasgow, 1865, vol. 11. p. 38, e¢ seq. 5 Quart. Journ. Geol. Soc. yol. xxii. 1866, p. 596, et seg. 6 Quart. Journ. Geol. Soc. 1875, No. 124, p. 624, et seg. 7 Pal. Ohio, passim; Pal. Illinois, passim ; etc. W. J. Sollas— Striated Triassic Pebbles. 79 Vil.—On Srriatep Pespsies FROM THE TRIASSIC CONGLOMERATE NEAR PortTsKEWET, Monmoutna. By W. J. Soruas, M.A., F.R.S.E., F.G-S. ; Professor of Geology in University College, Bristol. URING a recent visit to the tunnel now in course of con- struction beneath the Severn, I was taken by my friend Mr. Evan Jones, of University College, to examine a heap of Triassic pebbles and conglomerate, which had been exploited from the bottom of one of the shafts of the tunnel on the Portskewet side of the river. My attention was at once arrested by the striated and polished surfaces presented by many of the pebbles, and the results of the short examination I was able to make of them are embodied in the following note. The pebbles are of all sizes, up to a foot or more in diameter, and they are well rounded at the edges and corners. Though they have evidently been derived from the adjacent Mountain Limestone, they break with a finely granular fracture like compact grit, owing no doubt to a crystalline structure superinduced by dolomitization. The matrix in which they were imbedded is a dolomitic paste containing numerous grains of quartz sand; it is coloured red with iron peroxide, which also colours the surface of the imbedded pebbles. The smoothed surface of many of the pebbles is abundantly striated, especially on and around the edges and corners; the strize commence as exceedingly delicate fine lines, which frequently deepen and widen in their course, till they terminate abruptly, so as to present the form of a half cone; at the deep end of the trough (base of the cone) a grain of quartz sand is sometimes found im- bedded. Sometimes however the striz are mere scratches thinning out at each end; they are not always straight, but sometimes curved, a whole group of parallel striaz being occasionally abruptly flexed to one side and then back again into their original direction. Now and then a furrow as much as a quarter of an inch wide may be observed, its sides being scored with delicate parallel striae. The presence of quartz grains in the matrix about the pebbles may be connected with their striation, and when a quartz grain is found imbedded at one end of a scratch, it may fairly be regarded as the instrument by which the scratch was produced. But to have produced the scratch it must have been (1) pressed against the surface, and (2) drawn along it. That the pebbles were pressed against each other, and thus exerted pressure on the sand grains lying between them, is shown by the fact that some of the smaller pebbles are sunk some distance into the larger, as though they had been pressed into a yielding substance. Nothing but great and long-con- tinued pressure could have brought about this result. The cause of this pressure is to be found in the thick deposits of sediment which once rested upon the pebble beds. Buta vertical pressure acting on an accumulation of loose pebbles would be resolved not only in directions normal to the touching-surfaces of 1 Sorby, Cardiff Nat. Soc. Trans. vol. v. 80 Notices oy Memoirs—The St. Gothard Tunnel. the pebbles, but also in others, leading to movements along lines of least resistance, by which the pebbles would become packed as closely as possible together. The quartz grains lying between the pebbles would then not only be pressed against, but also dragged over them. As they began to move, they would produce a delicate almost imper- ceptible striation, but with continued progress this would deepen, the grit would “bite” more deeply into the stone, and would at length become too far imbedded to overcome the resistance in front; then it would be brought to a sudden standstill, and remain as we now find it implanted at the end of the trough which it has excavated. The history of the pebbles is then as follows: the Carboniferous Limestone, which crops up close to Portskewet around Chepstow, was denuded in Triassic times, and furnished material for a beach of rounded and polished pebbles on the shores of the Triassic sea ; subsequent deposits, probably including Jurassic and Cretaceous sediments, were superimposed upon this beach, and under the con- siderable pressure which resulted the pebbles were packed closely together, forced one into the other, and pitted all over with imbedded sand grains; lateral movements dragged along the sand grains over the surfaces of the pebbles, scoring them with delicate furrows and striz. Subsequently the dolomitic paste between the pebbles cemented into a hard matrix, and bound the whole together into a conglomerate. In a note read before the British Association last August, I showed that certain fragments of limestone in a Triassic breccia retained the striation (slickenside) that had been impressed upon them before they were detached from the parent rock and deposited in their present place. We now find an instance of a contrary kind, in which the striz on imbedded pebbles have been produced subsequent to deposition ; but in neither case could an experienced observer be deceived for a moment as to the real nature of the striation; glacial action is here indeed altogether out of the question. It might be thought that the glacial origin assigned to the striations on certain fragments of stone from the Old Red Sandstone and Permian deposits, is called in question by these observations; the exact con- trary 1s, however, the case ; since while we have shown that striation may be produced on included fragments in other ways than by the action of ice, we have at the same time shown that no difficulty need be felt in distinguishing such striation when it occurs. aS PO egonsys) Os IMEEM ORCI SS) Tur Monr Sr. Gornarp TuNNEL. Sulle condizione geologiche e termiche della grande galleria del S. Gottardo. Nota dell’ ing. F. Grorpano, Boll. del R. Comit. Geol. d'Italia. Sept. and Oct. 1880, Vol. XI. N the last Bolletino Inspector F. Giordano gives alengthy report | on the geological conditions of the St. Gothard tunnel, and many of the facts and particulars he tells us are drawn from the various published papers of the late chief engineer Stapff. Particulars are Notices of Memoirs—The St. Gothard Tunnel. 81 given as to the mode of excavation, and then the geological structure is considered. The rock section was found to be much the same as the preliminary investigations had indicated, consisting of granitoid gneiss, black schist, micaceous felsites with a small quantity of cipollino and other calcareous rocks in the large U folds under the Ursern and Ticino valleys. The fan structure, so general in all the Alpine ranges, was very marked, the strata spreading out in the St. Gothard mountain, and forming north and south the two U folds mentioned. It was in this northern fold under the Ursern valley that the greatest difficulties of the undertaking were met with, for the Ursern gneiss was found to be decomposed down to a very con- siderable depth, here over a thousand feet below the surface, so that the felspar had become a soft clay, and in consequence the expense was raised from about 3,500 or 4,000 up to 20,000 francs a métre. But the most interesting results of the undertaking are the obser- vations made on the temperature of the air in the tunnel, together with comparisons of the temperature of the air and the earth at the surface. The figures of the temperature of the air are from observa- tions taken in meteorological stations on the route, and in order to obtain the temperature of the earth at the surface, the temperature of the streams were measured and calculations were made from a large series of such observations. The increase of temperature in the Mont Cenis tunnel was shown to be 1° Centigrade in each 514 métres below the surface, which increment was less than was expected from previous data, mostly obtained in mines and borings. The St. Gothard measurements give 1° C. in about each 52 métres, thus both very closely cor- respond, considering that there are always modifying circumstances, as, for instance, decomposition of the rock where pyrites and other substances occur. The maximum temperature was 30:5° C. under 1700 métres of rock, and the increase of temperature is shown to vary approximately with the profile of the mountain mass above, though somewhat modified by the surrounding mountains. A very interesting concluding chapter deals with the lessons which may be learnt from this gigantic enterprise, and as the health of the workmen has in this case been very seriously affected by the unfavourable condition of work, it is evident that means must be taken to improve the ventilation in any similar undertaking, and Giordano considers that the Belgian system of making the advance gallery at the top gives less satisfactory results in this respect than the English system, where the preliminary gallery is at the base of the future tunnel, and as at present tunnels are proposed both through the Simplon and Mont Blane, these questions have a practical importance. The Simplon tunnel, according to one plan, would pass under a superincumbent mass of 2250 métres, and this, according to the law now formulated regarding the increase of temperature, would give 47° C. in the middle of the tunnel; according to another proposition the tunnel would be at a greater altitude, and would DECADE II.—VOL. VIII.—NO. Il. 6 82 Reviews—Hull’s Coal-fields of Great Britain. give a temperature of 40°C. In the proposed Mont Blanc tunnel, however, the mountain mass would be greater than in either of the Simplon routes, and the temperature even higher. M. Dubois- Reymond has said that work under such circumstances would be impossible in a dry temperature of more than 50° C., or in a moist one of over 40° C., but Herr Stapff considers that some of the deep mines show that this is below the mark, but, however, points out the great difficulties that would accompany any such undertaking where there are a large number of workmen, even were no animals used, and even with every precaution taken in accordance with the experience now gained. A good coloured geological section, together with a comparative diagram of the temperature, accompanies the paper. A. W. W. gS7) dE We AG 2 WS —_—_@—__—_ I.—Tuer Coat-rietps or Great Brirain; Tuer HrsrTory, STRUCTURE AND Resources. With Descriptions of the Coal- fields of our Indian and Colonial Empire, and other Parts of the World. By Epwarp Hui, M.A., LL.D., F.R.S., ete. 8vo. 4th edition. (London, 1881: Edward Stanford, 55, Charing Cross.) N important addition to the literature of our Coal-bearing rocks has just appeared in the fourth edition of Prof. Hull’s work on “The Coal-fields of Great Britain.” Few books have had so great a success, or of which new editions have been called for so rapidly. The third, embodying the Reports of the Royal Coal Commission, was published in 1878, and now in little less than eight years we are presented with the fourth. Portions of the work have been largely re-written, a new frontispiece representing characteristic plants of the Coal period, and three woodcut sections have been added. The latter include sections across the Castle Comer and Tyrone Coai-fields respectively, and a section through the London basin. The chapter devoted, in the last edition, to the consideration of the Animal and Vegetable remains of the Coal period has been split up: the latter portion is entirely new, having been drawn up by Prof. Williamson, F.R.S. As might have been expected, the stratigraphical classification has been modified to meet the more recently enunciated views on this subject as expressed by Prof. Hull in the Quarterly Journal of the Geological Society, for 1877. The statistical portions of the work have been brought down to the date of 1878, whilst the highly important question of quantities, both wrought and unwrought, has been re-considered. The results given in the present volume naturally differ considerably from those stated in the last edition, allowing for the output during the interval between the appearance of the two volumes. In several instances Prof. Hull bows to the decision of the late Coal Commission in this matter, always, however, with the reservation, that seams of Reviews—Hull’s Coal-fields of Great Britain. 83 Coal below two feet in thickness should not be calculated in estimat- ing our future Coal resources. In this we agree with Mr. Hull. The presumable quantity of Coal yet to be worked in Great Britain and Ireland, after necessary deductions, and at a depth not exceeding 4000 feet, is In visible Coal-fields .................. 79,752.000,000 In concealed Coal-measures ......... 56,273,000,000 Motalitons!eenecceesecseos LOo,020,000,000 “a supply,” adds Prof. Hull, “which, if drawn upon at the rate of one hundred and thirty millions of tons, the quantity of 1878, would be sufficient to last for more than a thousand years.” The annual production of Coal over the whole globe is now said to be two hundred and eighty-nine millions of tons per annum. Under this heading the quantities have been brought up to dates varying from 1873 to 1879 for the various countries. During the past four years (1876-1879) the increase in output in our own country has been practically stationary. That for 1879 amounted to 134,008,228 million tons. In the chapter on concealed Coal-fields an account of the recent important borings in the S.E. of England has been added, especially those of the London area. Prof. Hull considers that, “‘ we must look to tracts lying south of the Thames Valley as the possible area of concealed coal-fields,”’ in the South-east of England, and especially, as Mr. Godwin-Austen has pointed out, along the margin of the North Downs, and the borders of the Wealden area. We are glad to see that Prof. Hull, where practicable, devotes a few pages to the organic remains of the various Coal-fields under description. The occurrence of marine bands of fossils is always strongly dwelt on, and plays an important part in the classification adopted throughout the work. As a remarkable instance of the persistence of a calcareous stratum over large areas, is cited the Spirorbis limestone of the Upper Coal-measures, which can be traced in the same position throughout the Coal-fields of Coalbrook Dale, and Forest of Wyre southward, through Lancashire northward, and Warwickshire eastward, representing an area of about 10,000 square miles, and is only on an average about one foot in thickness. The descriptive portions of the various Coal-fields have not been greatly altered, or added to, and remain nearly the same as in the last edition, excepting, of course, the information relating to quantities won and still to be wrought. In the chapter devoted to the Coal-fields of Europe, a useful table is introduced, showing the corresponding groups throughout the British Islands and the various Continental Coal-basins. It appears that the uppermost division of the Coal-measures is usually absent from the latter. In the South Staffordshire Coal-field the great ten- yard, or “Thick Coal,” has been either worked out, drowned, or destroyed to such an extent that probably little more than one-tenth remains to be won. Professor Hull wisely suggests that the coal proprietors of the district should combine to unwater this large area. 84 Reviews— Wallace's Island Life. The general succession of the Carboniferous Series in Scotland has been modified to meet the author’s latest views on Car- boniferous classification, or more properly into four groups, instead of three, as in England. These do not correspond in every way with the subdivisions adopted by the Geological Survey of Scotland. We cannot help thinking some further useful details might have been gleaned about the Scotch Coal-fields from some of the more recently published “‘ Explanations of Maps” of the latter body. The available Coal in Scotland for future use is estimated at about 9,648,000,000 tons. In Ireland, the Antrim Coal Series is now assigned by Prof. Hull to the position of the Lower Coal and Ironstone Group of Scotland (= Edge Coal Series, or Middle Carboniferous Limestone Group of the Geological Survey), and the Yoredale Series of the North of England. The account of the Indian Coal-beds has been completely revised. The age, following the views of Messrs. Medlicott and Blanford, is now stated to range from the Permian to the Upper Jurassic. There are thirty-seven separate fields, of which five only are regularly © worked. The information concerning the Australian Coal-fields is hardly up to date, and might advantageously be increased now that such a large mass of information has been brought together relating to the productive beds of New South Wales, and the unproductive strata of Victoria. We are, however, very glad to see that the views of the late Rev. W. B. Clarke have been more closely followed in this work than those of others who have written on the subject, although less conversant with it. In the account of the African and Canadian Coal-seams, Professor Hull has availed himself of recent Reports and Surveys. We must, in conclusion, congratulate the author upon having again brought his useful and important task to a most successful termination. We shall look forward, in the future, to the appear- ance of another and enlarged edition, with even greater feelings of pleasure than the perusal of the fourth has afforded us. As before, the work is published by Mr. Ed. Stanford, and everything appears to have been done to render it as complete and accurate as possible. TI.—Isuanp Lire; or, THe PHENOMENA AND Causes oF INSULAR FAauNAS AND FLORAS, INCLUDING A Revision AND ATTEMPTED SoLurrion oF THE PRoBLEM oF GroLocricaL Ciimares, By ALFRED Russet Wautace. (Macmillan & Co.; 1880.) HE author desires this volume to be regarded not only as a popular supplement to his Geographical Distribution of Animals, but as a work complete in itself. He considers that the treatment of the subject has been placed on a sounder basis owing to the establishment of a number of preliminary doctrines, of which the most important are those “‘ which establish and define (1) the former wide extension of all groups now discontinuous, as being the neces- sary result of Evolution; (2) the permanence of the great features Reviews— Wallace's Island Life. 85 of the distribution of land and water on the earth’s surface; and (3) the nature and frequency of climatal changes throughout geological time.” Thus it will be perceived that this work, though dealing in the main with biological questions, enters to a considerable extent into physical ones, and has therefore a double claim to the notice of geologists, who will be anxious to know whether the author suc- ceeds in establishing the three preliminary doctrines detailed above, ana how far they assist him in clearing up the many anomalies of Island Life. The first part of the book is occupied with the phenomena, laws, and causes of the dispersal of organisms, wherein the author dis- cusses the general features presented by animal distribution, as well as the changes which have been the most important agents in bringing about the present condition of the organic world. In the second part he proceeds to apply the principles previously enunciated in the elucidation of the phenomena appertaining to Insular Faunas and Floras. Part L—The first five chapters deal mainly with the zoological aspects of distribution. Amongst the elementary facts some remark- able instances of discontinuity even on continents are detailed, and it is observed that such “numerous examples of discontinuous genera and families form an important section of the facts of animal dis- persal which any true theory must account for.” We may feel sure that the question of Evolution as the key to Distribution is ably stated by a naturalist who shares with Darwin the honour of having established the most important principles as to the origin and development of species and genera. ‘The tendency to change, always more or less inherent, though stimulated and taken advantage of by circumstances, in combination with the powers of dispersal of organisms under different conditions, may serve to explain much of the existing distribution of plants and animals. In concluding this part of the subject, the author observes that the theory of Evolution necessitates the former existence of a whole series of extinct genera to fill up the gap between the isolated genera which in many cases now alone exist, while it is almost an axiom of natural selection, that such numerous forms of one type could only have been developed in a wide area and under varied conditions implying a great lapse of time. Thus far, Mr. Wallace has been on his own ground, and there are few paleontologists at this time of day who are not more or less convinced of the truth of the first of his three great principles or doctrines. But when, in dealing with geographical and geological changes, he arrives at the consideration of the second principle, viz. the permanence of continents, there is by no means that unanimity amongst the authorities which the statement in the preface might lead the public to suppose. Geologists, especially in England, cling to the views of the great fathers of their science, and thus the opinions of Lyell and others as to a complete change of land and sea having taken place over and over again are, as he 86 Reviews— Wallace's Island Life. admits in Chapter VI., very generally held. Nor are these views confined to such speculations as those of a late President of the Geological Society of Liverpool. ‘They are still held, to a certain extent, by no less an authority than Professor Huxley, who writes (Nature, Nov. 4, 1880): “There is nothing, so far as ] am aware, in the biological or geological evidence at present accessible, to render untenable the hypothesis that an area of the mid-Atlantic or Pacific sea-bed as big as Europe should have been upheaved as high as Mont Blane, and have subsided again, any time since the Paleozoic epoch, if there were any grounds for entertaining it.” Thus the believers in the possibility of an Atlantis, notwithstanding the severity of our author’s remarks (p. 398), may take comfort in the fact that Prof. Huxley deems such a thing possible, though he does not say that the event ever took place. ‘The business of geologists is not so much to speculate on possibilities as to weigh the available evidence, and nothing can be clearer than the fact that the Jurassic, Lower Cretaceous, and Tertiary deposits, in our own country at least, are more or less of a shallow water or marginal character ; but when Prof. Huxley, some three-and-twenty years ago, spoke of Atlantic ~ mud as “modern chalk,” the converse of this proposition was imme- diately taken for granted, viz. that the chalk must have been an abyssal deposit.. Thus this latter supposition strongly favoured the then prevailing doctrine of the secular interchangeability of the great land and water areas. To combat this notion the author devotes several pages, and he certainly has the authority of Sir Wyville Thompson in support of his introductory statement, “ That few of the rocks known to geologists correspond exactly to the deposits now forming at the bottom of our great oceans.” Still, the origin of chalk is a great puzzle, and some of Mr. Wallace’s statements are likely to lead to much discussion. Some- times, indeed, he seems to advance arguments against his own hypotheses, as, for instance, when he claims for his great central sea the depth of a few thousand feet, and immediately quotes S. P. Woodward to the effect that Ammonites, etc., were limited to depths not exceeding 180 feet. We are far from saying, however, that even these statements are essentially irreconcilable. There are large vertical regions of the chalk singularly free from Cephalopoda, and though, perhaps, not much of the sea in which chalk was deposited ever attained a depth of a few thousand feet, yet a depth of several hundreds—say even a thousand—might be sufficient to prevent the accumulation of any notable quantity of Ammonite remains. The composition of chalk is also an enigma, for Foraminifera form only a small part of it. On the strength of the Faxoe beds in Denmark being highly coralline, he observes, “We have a clear indication of the source whence the white calcareous mud was derived which forms the basis of chalk.” This is a bold assumption. In the first place, there are no regular reef-builders at Faxoe, the principal species being a Caryophyllia. Secondly, Lyell (Tr. Geol. Soc. vol. v. p. 248) expressly says, ‘There are patches of coral cemented together by white chalk, but with these exceptions no Reviews— Wallace's Island Life. 87 portion of our Oolitic rocks can less resemble ordinary chalk than the stone of Faxoe.” We may add that the undoubted coral muds which have gone to form many of our Jurassic limestones yield a very different kind of rock to any variety of chalk known to us. Yet it must be admitted that Sorby, in his first address to the Geological Society in 1879, says, ‘that very many of the minute granules (of chalk) are identical in appearance with those derived from aragonite shells and corals,” and he further observes that, though the more or less entire shells of Foraminifera form an important constituent, ‘‘ yet that other larger calcareous organisms have probably yielded the greater part of the rock.” When we quit the basin of the North Sea for that of the 8.W. of France, the evidence for coral life is stronger, and the abundance of Hippurites, a relative of the reef-dwelling Chama, also points in this direction. Whatever has been the origin of the composition of the peculiar rock known as chalk, the fairest inference seems to be that the conditions which produced it, in this country at least, were pelagic, though by no means oceanic, and hence its existence gives no colour to the notion of a great interchange of continent and ocean. Sir Wyville Thompson is quite in accord with the author on this point when he says (Nature, Nov. 1880), “The Chalk of the Cretaceous period was not laid down in what we now consider deep water, and its fauna, consisting mainly of shallow water forms, merely touches the upper limit of the abyssal fauna.” Prof. Geikie (quoted at p- 94) is practically of the same opinion, when he says that during the Cretaceous period “the Atlantic sent its waters across the whole of Europe and into Asia, but they were probably nowhere more than a few hundred feet deep.” Unfortunately, in thus ignoring the existence at this period of the Scandinavian and other highlands of Old Europe, Prof. Geikie gives colour, perhaps unintentionally, to the notion that the leading features of continents are less perma- nent than the theory adopted by the author would lead us to suppose. This doctrine, viz. the permanence of continents and oceans, he considers lies at the root of all our inquiries into the past changes of the earth and its inhabitants, and it receives strong confirmation from the evidence adduced by Darwin, who has observed that hardly one truly oceanic island has been known to afford a trace of any Paleozoic or Mesozoic formation, so that they have not preserved any fragment of the supposed ancient continents, nor of the deposits which must have resulted from their denudation. * Thirdly, the author discusses the changes of climate which have influenced the dispersal of organisms, and this leads him to the subject of glacial epochs and their causes, to which he devotes three chapters. Those readers who are anxious to arrive at the gist of the work, viz. the phenomena of insular life, will perhaps regret that so much space has been devoted to this class of speculation, and some might even think that with a concise summary of conclusions in the text, the rest of the matter might have been relegated to an appendix, or reserved for a separate work. But these subjects are 1 See ante, p. 75, “ Oceanic Islands,’ by T. M. Reade, F.G.S. 88 Reviews— Wallace’s Island Life. undoubtedly popular—they appeal so powerfully to the imagination, —and may in a certain sense enhance the value of the volume. The last chapter of Part I. discusses the earth’s age, and the rate of development of animals and plants. Part I].—When the difficulties presented by the peculiarities of island life are mastered, Mr. Wallace is of opinion that we shall find it comparatively easy to deal with the less clearly defined problems of continental distribution. Hence the importance of the subject. Islands have had two distinct modes of origin, and the difference is fundamental. They are oceanic or continental. Darwin has shown that with very few exceptions all the remoter islands of the great ocean are of volcanic or of coralline formation, and that none of them contained indigenous mammalia or amphibia. Con- tinental islands are more varied in their geological formation, and may be divided into two groups—ancient and recent. Islands of an anomalous character constitute a fourth section. Amongst the Oceanic Islands are the Azores, Bermuda, the Galapagos, St. Helena, and the Sandwich Islands. Amongst the recent continental islands are the British Islands, Borneo and Java, and Japan and Formosa. Madagascar is an example of the type of ancient continental islands, whilst Celebes and New Zealand figure in the exhaustive division. It would clearly be impossible within the limits of a review to give even a sketch of all these chapters, each of which is a little treatise of itself, full of the best information in that branch of natural history which is connected with the geographical distribution of animals and plants. A sample of the mode of treatment of each of the three principal sections must suffice. 1. Oceanic Islands:—The Azores, which bear the same relation to Europe that the Bermudas do to America, lie in the course of the south-westerly return trades, and also of the Gulf-stream. They are 900 miles from the coast of Portugal, with a maximum depth of 2,000 fathoms intervening, and are destitute of all terrestrial indi- genous vertebrata. To the oceanic type they present a single excep- tion, in that one of the islands contains a small deposit of Miocene age. Thus the group may be of considerable antiquity, but the fauna, “at all events as regards the birds, had its origin since the date of the last glacial epoch.” The small amount of differentiation which time has effected in the birds—a bullfinch being the only speciality —is one of the principal reasons for this belief in the recent origin of the fauna, but the explanation to which Mr. Wallace points is scarcely satisfactory. The glacial theory is adangerous weapon even in the hands of the most experienced geologists, and draws quite as largely upon the unscientific imagination as Atlantis or Lemuria— those especial bugbears of the author. When, therefore, he would have us infer that all land birds were destroyed by the severity of glaciation in a group of islands situated as these are, and at the sea- level, we should at least expect him to indicate some undoubted evidences of ice action in the islands themselves, before consenting to entertain such a proposition. Reviews—— Wallace's Island Life. 89 Why not try submersion? He believes that a submersion to the extent of nearly 2,000 feet destroyed much of the life of the British Isles during the latter part of the Glacial epoch. And if a steady- going continental island like Britain, with a pedigree of rocks equal to any in the world, should have thus suffered, why not a volcanic accumulation in mid-ocean, presumably unstable by reason of its composition ? It is true that Pico is 7,000 feet above the sea, though this is very exceptional. But the submersion of an oceanic island is inconvenient, as this might favour the notion of Atlantis. The zoological reasoning is, as usual, admirable throughout the chapter. 2. Recent continental islands.—“ Great Britain is perhaps the most typical example of a large and recent continental island now to he found on the globe.” All geologists are aware that the British Islands rest upon the 100-fathom platform, which extends in a sweep from the coast of Jutland round by Shetland and Ireland to the south-west of France, and that a rise of less than half this depth would join England to the continent. Mr. Wallace goes into the question of the direct evidence that exists of this recent union, espe- cially quoting the cases of the well-known submerged forests in Cornwall, Devon and the Bristol Channel. Certainly the forest-bed of Cromer, in Norfolk, also mentioned by him in this connexion (p. 317), belongs to quite a different category, as this is a pre-glacial forest bed, almost Pliocene in its character, and can afford very little proof of our latest union with the continent, which “ geologists are all agreed “was subsequent to the greatest development of the ice, but probably before the cold epoch had wholly passed away.” The buried river channels in Scotland, far below the present sea-level, and the discovery of fresh-water and littoral shells at considerable depths off our coasts, are additional proofs of former elevation. On the other hand, the well-known phenomena of Moel Tryfaen, and elsewhere, are indications of a submergence which is, the author states, in no small degree, the cause why our islands are so poor in species, since sufficient time had not elapsed for immigration to have been completed “before the influx of purely terrestrial animals was again cut off.’ This would seem to imply also that the communti- cation might not have been very wide. Amongst the higher animals no more than three species—all birds—can be said to be peculiar, and, whilst Germany has ninety species of land mammalia, Great Britain has forty, and Ireland twenty-two. Possibly the respective areas of the tbree countries may have something to do with this, but the same cannot be said of the more slowly moving reptiles and amphibia, since Belgium has twenty-two species and Ireland only four. We are much better off in freshwater fishes, there being no less than fifteen peculiar, of which ten are species of trout and charr restricted to certain lakes in the British Isles. These local modifications are due to restricted intercourse, and the result is the same as with the life of Oceanic islands. The remainder of this chapter (xvi.) deals with the insects, land and fresh water shells and flora, and is full of highly interesting matter. 90 Reviews—Wallace’s Island Life. 3. Ancient continental islands.—The extraordinary complexity of the organic relations of Madagascar, says Mr. Wallace, is due, partly to its having received its animal forms from two distinct sources, but mainly to its having been separated from a continent now zoologically in a different condition. The facts and reasonings of this important chapter, though in the main zoological, have a distinct geological bearing. Madagascar has not the characteristic animals of either Africa or Asia. Half the existing species consist of Lemurs. In fact, the island is a sort of Zoological Garden of high antiquity, free from the ravages of the large Carnivora, where decaying groups of creatures, which have elsewhere perished or become scarce, maintain a comparatively secluded existence. Why is this so? When Madagascar was united to Africa, from which it is at present separated by waters of considerable depth, the adjacent continent was then entirely severed from Arctogza by the nummulitic sea, and constituted a sort of Australia, poor in the higher forms of life. The upheaval of this sea-bed in Miocene times admitted the higher types of mammalia, which were developed in the great Huro-Asiatic continent, to the mainland of Africa, but Madagascar had then become an island, and the great beasts were thus excluded from it. We know from the rich deposits of fossil mammals in the Miocene beds of Europe and N.W. India that the great African mammals inhabited those regions. These reasonings tend to explain the absence of certain forms; we must next consider the origin of the existing groups. Doubtless Madagascar, through the anagiolamdl of Africa, had an earlier union with Ar ctopeea, though “Fe is rather a strong assumption that, otherwise, it could never have obtained any mamimalia (p. 891). However, the Lemurs, Insectivores, and Civets are known to have inhabited Hurope during the Hocene and Miocene periods, and thus a certain geo- graphical link is established between the ends of groups now wide asunder. The dispersal of these groups, superinduced by changes of surface and climate, throughout long ages of geological time, may thus serve to render possible an explanation of such an extreme case as that of the insectivorous Centetide, now confined to Madagascar and the West Indies. The question whether the birds of Madagascar require the adop- tion of the hypothetical Lemuria is scarcely one to be discussed in the GxrotoeicaL MacGazinze. There are about one hundred and five land birds, all but four or five being peculiar. When we consider that the Azores, more than thrice as far from the mainland, contain but one bird peculiar to them, and bear in mind also that the author regards their whole avifauma as the result of recent immigra- tion, voluntary or involuntary, we can only express surprise at “the unenterprising character of the birds of Hast Africa, who do not care to cross the Mozambique channel, though the Comoro Islands offer a series of convenient halting-places. The chapters on New Zealand, and on the Arctic element in South Temperate Floras, complete the details of Island Life—a work which is certain to be extensively read, and which is full of instructive Reports and Proceedings—Geological Society of London. 91 matter. We recognize throughout the vigorous original touches of the accomplished biologist, and if, in his treatment of some of the problems of speculative geology, the results seem not quite so satisfactory, the faults, if there be any, are perhaps less with the author than in the nature of the subject. The volume is well got up, and usefully illustrated with maps throughout. W. 4H. H. IS SOiVsHS) YNENED) A5ss{O@se SiN Key Grotogrcan Society or Lonpon. T.—Dee. 15, 1880.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. “On the Constitution and History of Grits and Sandstones.” By John Arthur Phillips, Esq., F.G.S. In the first part of this paper the author described the micro- scopic and chemical structure of a large series of grits, sandstones, and, in some eases, quartzites, of various geological ages, noticing finally several sands of more or less recent date. The cementing material in the harder varieties is commonly, to a large extent, siliceous. The grains vary considerably in form and in the nature of their inclosures, cavities of various kinds and minute crystals of schorl or rutile not being rare. The author drew attention to the evidence of the deposition of secondary quartz upon the original grains, so as to continue its crystal structure, which sometimes exhibits externally a crystal form. This is frequently observable in sandstone of Carboniferous, Permian, and Triassic age. Felspar grains are not unfrequently present, with scales of mica and minute chlorite and epidote. Chemical analyses of some varieties were also given. The author then considered the effect of flowing water upon transported particles of sand or gravel. It results from his investigations that fragments of quartz or schorl less than 31" in diameter retain their angularity for a very long period indeed, remaining, under ordinary circumstances, unrounded; but they are much more rapidly rounded by the action of wind. It is thus probable that rounded grains of this kind in some of the older rocks, as, for example, certain of the Triassic sandstones, may be the result of Aiolian action. 2. «On a New Species of Trigonia from the Purbeck Beds of the Vale of Wardour.” By R. Etheridge, Esq., F.R.S., President. With a Note on the Stratigraphical Position of the Fossil by the Rev. W. R. Andrews. In this paper the author described a species of Trigonia discovered by the Rev. W. R. Andrews in the “Cinder-bed” of the Middle Purbeck series in the Vale of Wardour. The specimens were found in the railway-cutting one mile west of Dinton station. The shell was referred to D’Orbigny’s section “ Glabre” of the genus Trigonia, and named Trigonia densinoda. In its ornamentation it closely resembles JT. tenuitexta, Lyc., of the Portland Oolite; but is more depressed and lengthened posteriorly, and destitute of the ante- 92 Reports and Proceedings— Geological Society of London. carinal space which occurs in all known Jurassic “ Glabra.’? The escutcheon is remarkably large and possesses transverse rug, as in the Neocomian ‘“ Quadrate.” The author regarded the species as a transition form connecting the two groups of Trigonie above mentioned. The description of the new species was accompanied by a note on the Purbeck strata of the Vale of Wardour by the ltev. W. R. Andrews. II.—Jan. 5, 1881.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. “The Archean Geology of Anglesey.” By ©. Callaway, Esq., M.A., D.Sc., F.G.S. With a Note on the Microscopic Structure of some of the Rocks, by Prof. T. G. Bonney, M.A., F.R.S., Sec.G.S. The author discussed the stratigraphy and lithological characters of the rocks in the following areas:—The border of the Menai Strait, the Llangefni region, and the central zone, about Bodafon, Llangwyllog, Llanerchymedd, and Paris Mountain, which, he considers, establish the following conclusions :— (1) that in Anglesey there are two Archean groups, the slaty and the gneissic ; (2) the slaty is composed of slates, shales, limestones, grits, con- glomerates, and chloritic schists, in which at present a definite order has not been ascertained. The gneissic group is composed of the following, in descending order—granitoidite, chloritic and horn- blendic schists, grey gneiss, quartz-schist, and hilleflinta; (8) the slaty series is occasionally foliated, but is usually in a partially altered state; the gneissic group is thoroughly metamorphosed ; (4) the slaty series has closer lithological affinities with the St. Davids volcanic group, the Charnwood rocks and the Lilleshall series than with the Bangor group; (5) the slaty series is un- doubtedly Pebidian, the gneissic series may, with some probability, be referred to the Dimetian. The microscopie structure of the principal varieties of the rocks mentioned in the above paper was described by Prof. Bonney. 2. “The Limestone of Durness and Assynt.” By C. Callaway, Esq., D.Sc., F.G.S. This paper gave the result of an examination of the vicinity of Durness and Inchnadamf, where Lower Silurian fossils occur in a limestone, as discovered by Mr. C. Peach. At Durness the only evidence of the limestone underlying the schist is the asserted fact of the dip being in the same direction; for all admit the junction to be a faulted one. The author showed that while the flagey (upper) schists dip uniformly to N.E., the limestone dips in a very variable manner H.S.H., H., and but rarely N.E., any dip N. of H. being exceptional, and then only at a distance from the schist. Again, the Smoo mass of limestone, cut off from the Durness area by a faulted strip of gneiss, dips either E.S.E., or even more to S. After discussing the relation of the quartzite and gneisses, the author passed to the Assynt district, and pointed out that the relations of the limestone and the quartzite are by no means satisfactorily established, that their conformity is rendered dubious by a marked Correspondence—Mr. Horace B. Woodward. 93 discordance. of strike, and that the limestone les in a synclinal basin, so that its dip in one place is in the opposite direction to that of the quartzite. From the above considerations the author holds that in these districts there is no ipeoole of the Lower Silurian age of the ua and newer series of flaggy gneiss and schist. “On a Boulder of JElomalblendls Pikrite near Pen-y-Carnisiog, sac ” By Prof. T. G. Bonney, M.A., F.R.S., Sec.G.S. The boulder described had been originally about a cubic yard in volume, and the fragments lay in a field left of the road from Pen-y-Carnisiog to Bwlyn. The ground-mass consists of hornblende and ser pentinous products with a little mica. In this are crystals, often 2 inch long, of brown hornblende with inclosures of altered olivine. The author doubted whether this hornblende is not a paramorph after augite; some of that in the ground-mass is certainly of secondary origin. He compared the rock with a pikrite from the Lleyn peninsula, and two described by Prof. Geikie from Fifeshire. It differs from all these, but has a singular resemblance to a pikrite from Schriesheim (Odenwald), except that it is rather more altered. He called attention to the rock in hopes that some geologists may discover it in siéu, as it will be of much value in deciding in what direction the ice has moved over Anglesey. CORRES PON DENCE. DISTURBANCES IN THE CHALK OF NORFOLK. Srr,—In the “Annals and Magazine of Natural History,” for October, 1880, is an interesting paper by Mr. Jukes-Browne on “The Chalk Bluffs of Trimmingham,” wherein, after noting the opinions of various writers concerning their origin and history, he expresses his own conviction that they are outlying rocks or needles tormed previously to the deposition of the Pliocene (fluvio-marine) series of the Norfolk coast. Mr. Jukes-Browne justly compares the disturbances in the chalk at Trimmingham with those at Whitlingham and Swainsthorpe, brought into notice by Mr. J. E. Taylor (Guox. Mac. Vol. II. p. 324 ; Vol. III. p. 44), and endeavours to support his own view of the date of the Trimmingham disturbance by reference to Mr. Taylor’s statement that the Chalk at Whitlingham was disarranged before the formation of the Norwich Crag. In a more recent paper by Mr. Taylor (Grou. Mae. Vol. VI. p. 509) the author, however, attributes the twisting and dragging up of the Chalk and its flint-layers to the agent which formed the Upper or Chalky Boulder-clay. This view I entirely coincide with, and during my Geological Survey-work near Norwich I obtained conclusive evidence that the similar disturbance at Trowse was due to glacial action (Got. Maa. Dec. II. Vol. VI. p. 380). I differ only from Mr. Taylor in assigning the formation of this Boulder-clay to the direct agency of land-ice, whereas he inclines to the view that the Upper Boulder-clay was formed under glacial-marine conditions, and that the stranding of ice-bergs would account for the disturbances of the Chalk. There is much to be said 94 Correspondence—Dr. C. Callaway—Prof. T. G. Bonney— on both sides of the question; my object, however, in writing this, was not to discuss the origin of the Chalky Boulder-clay, but to point out that the more remarkable disturbances in the Chalk near Norwich are of glacial origin, and subsequent to the deposition of the Norwich Crag. The section at Litcham, described by Mr. 8. V. Wood, jun., tells the same story; and having visited the Bluffs at Trimmingham on many occasions with my colleague, Mr. Clement Reid, I have been led to adopt his explanation that the disturbances of the Chalk there were produced by land-ice. FAKENHAM. Horace B. Woopwarp. THE PRE-CAMBRIAN ROCKS OF BRITAIN AND BOHEMIA. Str,—In Mr. Marr’s valuable paper On the Pre-Devonian Rocks of Bohemia, published in the last number of the Geological Society’s Journal, there is one point on which further evidence would seem desirable. I refer to his correlation of the Bohemian gneissic series with the St. David’s Dimetian. He describes the Bohemian rocks as “oneiss,” “gneissic rock . . . . interspersed with small garnets,” “white foliated quartzose rock,” ‘crystalline limestone ...... strongly foliated, and containing silvery mica.” Besides these rocks there is a “band of graphite” and dykes of ‘black eclogite.” Having examined the Dimetian of St. David’s from top to bottom, T did not find any one of the varieties named by Mr. Marr. The series is mainly composed of quartzite and granitoid rock, and the existence of foliation has not been proved in either the quartzose or the more felspathic types. I do not deny the Dimetian age of the Bohemian gneiss, but I should hesitate to accept the present evidence as decisive of the point. From Mr. Marr’s description, the Pebidian age of étage A appears highly probable, and the discovery is of great interest. The two Pre-Cambrian groups in Bohemia are in their lithology not unlike the two Anglesey series, of which full descrip- tions will shortly be communicated to geologists. If the older Anglesey series could be definitely accepted as Dimetian, Mr. Marr’s opinion would receive strong confirmation. C. CALLAWAY. WELLINGTON, SaLor, Nov. 30, 1880. ON THE TUSCAN SERPENTINES. S1r,—The author of the notice of Prof. Pantanelli’s paper I Diaspri della Toscana, etc. (Grou. Mac., 1880, p. 564) inadvertently attributes to me an opinion which I do not hold, when he includes me among those who have recently maintained “that the (Tuscan) serpentines represented true submarine lavas of the Upper Hocene.” On the contrary, in my paper (Vol. VI. p. 362) I am at some pains to show that these serpentines are intrusive in the diaspro, etc. The evidence against their being contemporaneous lava flows is strong. It is a remarkable thing that olivine rocks appear very rarely to reach the surface. I have never myself seen a serpentine which was not intrusive. Some pierites, however (e.g. that described by Professor Geikie in his paper on the Volcanic Rocks of the Firth of Forth), and limburgites appear to be lava flows, as may possibly be one or two other olivine rocks. T. G. Bonney. Professor T. Rupert Jones—Mr. W. W. Watts. 95 ENTOMOSTRACA IN COAL-SHALES. Srr,—In the black shale lying around the bases of some of the Sigillarian tree-stumps or stools, containing remains of small Amphibia (Dendrerpeton, etc.), and Land-shells (Pupa, etc.), at the South Joggins, Principal Dawson, of Montreal, has detected numerous specimens of Entomostraca.! Portions of this shale, forwarded for examination, have yielded to my friend Mr. J. W. Kirkby and myself several specimens of Carbonia fabulina, J. and K.,? mostly of the typical form, but some belong to the variety which we term humilis.» All of them have the surface of the valves either punctate or subreticulate. The muscle-spot is only indicated in one or two subtranslucent specimens. A single valve of a larger and relatively longer species is near to, if not identical with, our Cythere ? bairdioides.t Besides 1. Carbonia fabulina, with its var. humilis, and 2. C.? bairdioides, there are present in this shale—3. Ganoid scales of Fishes; 4. very thin shells like Anthracomya (Naiadites) ; 5. Spirorbis (carbonarius, or near it); 6. bits of carbonized wood, showing structure ; 7. Obscure Plant Remains, abundant. T. Rupert JONEs. CERVUS MEGACEROS IN BERKSHIRE. Str,—Portions of the Antlers of two individuals of the Gigantic Trish Deer (Cervus megaceros) dug out of the Peat of the Kennet Valley, at Aldermaston, have been lately procured by my friend Mr. Walter Money, F.S.A., of Newbury, and will probably find a resting place in the Museum of the Oxford University. This authenticated find of Cervus megaceros in the Post-glacial or Quaternary alluvium of Berkshire will be of interest to some of your readers. T. Rupert JONES. PEBBLE FROM THE CAMBRIDGE GREENSAND. Sir,—I notice that in your September Number Mr. Keeping calls attention to a pebble of the Wrekin devitrified pitchstone which was found in the Upper Neocomian deposit of Potton. It may be of interest to some of your readers to know that I found a pebble of a rather similar nature in the Cambridge Greensand near Horningsey, last June. It was a subangular fragment showing well-marked fluidal structure. Prof. Bonney kindly had a thin section cut for me, and examined it. He said, “It is a sort of devitrified pitch- stone or rhyolite with well-marked fluidal structure; it is inclined to be spherulitic, and the nature is undoubted.” He thinks, how- ever, that it has not exactly the structure of the Wrekin pitchstones, but might possibly be matched either in Scotland or Norway. Sipney CoLLeGEr, CAMBRIDGE, Nov. 14th, 1880. W. W. Warts. 1 See the ‘‘ American Journal of Science,” vol. xx. November, 1880, p, 404. 2 « Annals Nat. Hist.’’ ser. 5, vol. iv. p. 31, pl. 2, figs, 1-10. S$ Ibid. figs. 11-14. 4 Ibid. p. 38, pl. 3, figs. 24-26. 96 Miscellaneous. PRESENTATION OF THE EDWARD WOOD COLLECTION TO THE YORK MUSEUM. Str,—The well-known collection of fossils formed by the late Mr. EK. Wood, of Richmond, Yorkshire, has been purchased by Mr. Wm. Reed, I'.G.S., of York, and by him presented to the Museum of the Yorkshire Philosophical Society, York. The collection consists of about 10,000 specimens, and is specially rich in fossils from the Cha venienong rocks. W. Keerine. Tue Museum, York, Jan. 17th, 1881. Mr. Reed had previously presented his own magnificent collection of fossils to the Yorkshire Philosophical Society. IVES @sbE eA BEE OS A Fosstz Rurnoceros In THE Fuirso.—The body of a large Rhinoceros was recently discovered in the Werohojanksi district, Siberia. It was found on the bank of a small tributary to the Jana (Lena?) river, and was laid bare by the action of the water. It was remarkably well preserved, the skin being unbroken and covered with long hair. Unfortunately only the skull of this rare fossil has reached St. Petersburg, and a foot is said to be at Irkutsk, while the remainder was allowed to be washed away by the river soon after it had been discovered. The investigation of the skull shows that this Rhinoceros (2. Merckii) is a connecting form between the species now existing and the so-called Rhinoceros ticho- rhinus, remains of which are not unfrequently found in the Brick-earth of the Valley of the Thames at Ilford, and in Prussia. Tur Readers of this Magazine will be glad to learn that Mr. A. R. Wallace, the celebrated explorer, naturalist, and author, is to receive a pension of £200 a year from the Government, in recognition of his eminence in zoological science, in promoting which he has done so much ‘good service. We are requested by the author to print the subjoined list of Errata in Mr. H. H. Howorth’s paper on ‘‘ The Mammoth in Siberia,’’ Guot. Mac. Dec. 1880, pp. 550—561. Page 551 line 29 for Berislinor read Bereshnoi. rn ey) 29 » Kolymak Pr Kolymsk. 99909 40 » Kazahs ” Kazaks. 9” 99 09 48 », Alansk un Alaseisk. By DBPL) op 1 >, Yerambei on Yerumbei. » 004 ,, 9 » 48 47, 99. 000 45 22 29 Hippopotamus ,, =H Cave-lion, aT ery) 27 » Musk Ox aA Musk Sheep. 9» 006 4, 2 », reindeer, most, ,, reindeer -moss. dot 9 p 26 >, sselakim 50 Sselakino. 59 99 last line » 188 114. 9 99 9, Oand6 ,, delete the authority between parenthesis, Sant (ioplardan 18 >, north of south. 9» 99 9» 04 &39 4, Samukof a Sannikof, >» » » ” >», Aililnoi Kis Kotelnoi. On eino es 46 », Erdmann 39 Ermann. » 060 ,, 2 » Yava, ” Yana. 5994 1239) ” 16 », Erdmann ” Ermann. By 6) ap 18 » Indiger we Indiga. ” ” ” 23 ” bushes ” trunks. 99 35 -, Awauka 95 Awamka, 9” 999 42 3 Amare >» Limax. 59 991) 99 9 2» anabora ” anatina. oy Sh op 45 » Breschof a Brjohof. +3 id. 86 id. Xi. 88. ” ” 50 ” 553, 1.233 558, 7. 233 559, 1. 3; 560, U0. 32 and 48, for Dudimo, read Dudino, THE GEOLOGICAL MAGAZINE. NEW ere niles. DECADE HI VOLS Vili No. II.—MARCH, 1881. (Cu RAL GMEINF/Aaay pea ey Abo anpaSr —»__ I.—Own tur ConNEXION BETWEEN TRAVELLED BLocks IN THE UppER PUNJAB AND A SUPPOSED GLACIAL Pertop In Upper Inptra. By A. B. Wynne, F.G.S., ete. HE transported blocks of the Indus Valley are not without some interest in connexion with the theory of an Indian Glacial Period akin to that of Hurope, and with regard to the support they do or do not give to that supposition. I do not propose to enter into the whole question of this Glacial Period, one much affected by observations made in regions which I have not explored, but only intend to discuss facts within my knowledge concerning a district with which I am better acquainted. The district is the Upper Punjab, the northern part of ‘the land of the five rivers,” and is almost entirely included in the local portion of the basin of the largest of these, the Indus or Abba Sin. From the last gorge of this great river, where it issues from the Himalayan Mountains, down to within a few miles of where it breaks through their furthest outworks in a southerly direction, a quantity of crystalline masses derived from the Himalayan ridges, and often of huge size up to 50 or 100 feet girth, are distributed for forty or fifty miles, chiefly on its left bank, and so far as twenty miles from the river itself. Similar blocks also occur locally along smaller tributaries of the Indus and of the Jhelum, which is one of its affluents, but these blocks are not known at any great distance from the hills. , ; The blocks in question were noticed many years ago in one of Dr. Verchere’s papers,’ and subsequently in the publications of the Geological Survey of India, where I have attributed their distribution to the agency of floating-ice ; but my friend and colleague Mr. Theobald claims that they are additional evidence in support of his view that extensive glaciers once descended from the Himalayas and left their detritus on the plains of India at elevations of and under 2000 feet, where the climate has so much changed that snow is now never known to fall. Mr. Theobald’s last paper on the subject appears in the Geol. Surv. 1 A. S. Beng. 36. pt. 2. DECADE II.—VOL, VIII.—NO. II. 7 98 A. B. Wynne—The Glacial Period in Upper India. Ind. Records, vol. xiii. pt. 4.1 After referring to the distribution of the blocks which J have called ‘the Indus drift,” he contends that they occur only on the surface of fluviatile deposits, and hence that they must form parts of lateral moraines or other glacially transported detritus, it would seem according to his view deposited from the melting both of solid glaciers and also of floating-ice. Where the limit between these two varieties of ice agency occurs he does not indicate, and it does not appear how his glaciers traversed the fluviatile deposits without disturbing them or sweeping them away. It seems to be generally received that towards the close of the great Tertiary period in the Punjab, during which rocks to the thickness of some miles were deposited, and the successive stages of the elevation of the Himalayas took place, one of the last up- heavals of these mountains occurred. It may also be considered highly probable that these earth-movements of the Himalaya were not always conterminous with the extent of the whole chain. However this may be, I have met with some evidence which may point to the possibility that the western or Punjab portion of the mountains was even so recently as during Post-Tertiary times much more elevated than it is at present. On two of the outer ranges, at heights of many hundred feet above the Indus, near the summits of the Chita and Salt Ranges in the vicinity of this river, I have found either coarse river-like deposits or scattered irregularly-shaped and rounded dark or variously-coloured river-stones, consisting of precisely the same Himalayan rocks as are now being rolled southwards by the river through its gorges far below. Upon these facts I rested the sup- position that the river channel was once situated at a height of something like a thousand or fifteen hundred feet above its present level,? in which case the neighbouring ranges of the Himalaya, as far as the sources of the river, might also have been much more lofty. 1 Tn this publication my colleague has scarcely given an accurate view of my statements or opinions. His suggestion that I thought the Indus had abandoned its deep rocky gorge at the Chita range since this was formed is not warranted by any- thing I have written. His view that stones from the bed of that river were carried up to villages on the summits of the range named, by their inhabitants for the purpose of decorating graves, had of course suggested itself to me, and been rejected for want of evidence that such villages or the graves of their inhabitants ever existed there. He classes me by implication as one of his Antiglacialists, because I have refrained from advocating his theory, for want of conclusive evidence. With these exceptions, and a few others of minor importance as to his limitation of the localities occupied by the travelled blocks, I only regret that the paper seems to prove nothing in support of the author’s views as to the connexion between the blocks and glaciation at low levels in India. : 2 In the paper alluded to before, Mr. Theobald argues that the Indus did not cross the Chita Range ata higher level, because he failed to find its erratics (7.e. trans- ported debris), caught in clefts between the limestone crags of the range. From his reference it would appear likely that he only crossed one or other of the low passes of the range by road, where the limited nature of his observations might lessen their force, if this were not entirely set aside by the fact that the mountain surface of that period must long since have been removed by denudation. The argument, however, was not that the river had wandered, but that it ran at a much higher level nearly at the same place. A. B. Wynne—The Glacial Period in Upper India. 99 Otherwise a slow elevation might be supposed to have taken place nearly at the same rate as the river cut its channel, or the result might be ascribed to the vast and continuous operation of aerial denudation, in reducing the altitude of the ground. If either the first or the last of these suppositions be correct, the greater elevation of the mountains would bring the regions of glaciers and perennial snows under existing climatic conditions nearer to the area now covered by the transported blocks. The Indus is famous for its debacles, and these, carrying in their rush fragments of glaciers laden with rock masses from the high regions into a lake (which there is reason to suppose once covered much of the Northern Punjab Steppe), it appears to, me would account very simply for the transport southwards of the blocks referred to, and also for their distribution. The lacustrine character of the silt or loess, extensively spread over the Rawul Pindi plateau, is in favour of the former existence of a lake or lakes in much the same relative position to the mountains as the Terai swamps at their foot further eastward, and in its waters the ice-floated blocks could have been impelled for some distance in the currents caused by floods. As the natural consequence of the ordinary glaciers of the mountains approaching nearer to the plains, owing to greater alti- tude, traces of these glaciers might still be found in ice-borne blocks resting where glaciers no longer exist beyond the area occu- pied by the supposed lake or lakes. Where such blocks rested on softer material than themselves, sub-aerial denudation would reduce their stability till they might be rolled into the deepest Khuds and river-courses, as is the case along the Upper Indus, the Upper Jhelum in Kashmir territory, or along its tributary the Nainsuk from Kaghan. It would thus appear that either within or beyond the area where floating-ice could move them, great transported rock fragments such as these could find their way into their present positions without the necessity for imagining that enormous glaciers spread in recent times from the Himalaya Mountains out over the plains of India, to elevations not more than 2000 feet (or even less) above the sea, or to distances of 40 or 50 miles away from these mountains—in the Upper Punjab. To any one familiar with the appearance of the “Drift” of Ireland and the glacial features of many of its hill regions, the great differ- ence between these features and the supposed glacier work in the Upper Punjab is so palpable, that the strongest possible doubts suggest themselves as to the probability of extensive glaciation at low levels in the north of India, and certainly when the circum- stances urged in favour of this bear any other interpretation, the alternative supposition gathers force from the comparison. 100 ZT. Davidson & G. Maw—U. Silurian Rocks of Shropshire. JJ.—Notes on THE PuHystcAL CHARACTER AND THICKNESS OF THE Upper SrnurtAN Rocks oF SHROPSHIRE, WITH THE BRACHIOPODA THEY CONTAIN GROUPED IN GrOoLOGICAL Hortzons. By Tuomas Davipson, F.R.S., and Groner Maw, F.G.S. (Continued from p. 13.) HROPSHIRE was always considered by Sir Roderick Murchison as one of the districts in which his Upper Silurian rocks could be most advantageously studied.!. We propose, therefore, in this communication to offer some few notes on the Geology and Palzon- tology of the Wenlock and Ludlow series; illustrated by the Brachiopoda, reserving for the present what we may have to com- municate with respect to the Upper Llandovery. The extensive washings undertaken by one of us have brought to light some fifty to sixty thousand specimens, of which some were previously unknown, while others were new to the district. The new species will be described and figured in the sequel. The occurrence of cleanly-washed fossils in the debris remaining from many of the clays and shales suggested to one of us that the potter’s process of levigation might be conveniently employed by the geologist for the collection of fossils, especially of the smaller species, from the soft shales, in which hand-picking is at best a most laborious process. The potter’s object in clay leevigation is to get rid of the coarser matter. The fossil collector pursues, as it were, the process in reverse by getting rid of all the clay and fine matter, and obtaining in a compact form the coarse debris, including the organic remains. A potter’s ‘“Blunging” or clay levigating machine, though it greatly facilitates the process, and enables large quantities of material to be quickly levigated,is not essential, as an experienced worker can in a day easily levigate several hundredweights of clay or soft shale, with the aid only of a tub and a stout wooden stirrer. The operator should provide himself with a set of sieves of the following mesh: 1, 2, 4, 6, 10 and 12 wires to the inch. Having digested in water, say, half a ton of material, the “ slip” or liquid clay is poured off through the No. 12 or finest sieve, which would catch any small fossils; and the remaining debris, which might weigh about a hundredweight, should be repeatedly washed with fresh water, by which all fine matter will be removed, and the material remaining will in most cases resemble clean coarse gravel, with which the operator will have further to deal. As this will 1 We follow Sir Roderick Murchison’s classification of the Lower Paleozoic formations, for no geologist worked harder to unravel the complications under which the Upper and Lower Silurian rocks were shrouded. The publication of the “* Silurian System’’ in 1839, with all its imperfections and on the model of Smith’s “« Strata identified by Organized Fossils,” did more than any other work to stimulate researches in the right direction all over the world. See also Barrande’s important paper ‘‘Du maintien de la nomenclature établie par Mr. Murchison,’’ Congres International de Géologie, p. 101, Paris, 1878. T. Davidson & G. Maw—U. Silurian Rocks of Shropshire. 101 ultimately be the subject of the laborious process of ‘‘ hand-picking,” it is desirable to reduce its bulk as much as possible. The whole is first passed through the sieve of one-inch mesh, which catches all the stones, lumps of undigested shale and the larger fossils, which are easily picked cut. The mass is thus reduced to from half to two-thirds of its weight, and is then dried. It greatly facilitates further operations, to sort this into separate sizes by passing the dried material successively through the sieves of 4 inch, ¢ of an inch, and 34> of an inch mesh. The fine matter passed through the 5 of an inch mesh seldom contains fossils, and may be thrown away. Now comes the final process of hand-picking from the three sorted lots of debris. These are spread out thinly on a slab of slate or a smooth board, and women, at a wage of 1s. 6d. a day, quickly per- form the operation, and readily learn not only to pick out the fossils from the gravelly debris, but also to roughly sort the species. As an instance of the good results of this process, we would men- tion that from one cartload of the Buildwas Beds of Wenlock Shale no less than 4300 specimens of one species, Orthis biloba, were obtained, besides a much greater bulk of other Brachiopods, amount- ing together to 10,000 specimens at least ; but this does not nearly represent the full wealth of life of this rich horizon, as many of the larger species, and others not completely calcified, would get broken up in the washing process, and we have had to supplement the species obtained by washing with a series of hand-picked specimens. The whole of the debris has been preserved after picking out the Brachiopods, as it abounds in minute corals and other fossils, which will we hope be investigated by other observers. The cost of the process, withthe aid of a potter’s clay blunging machine, amounts to about 18s. per ton of materials. This includes the cartage of the shale two or three miles, the whole process of washing, and the hand-picking of the fossils by paid workers. The following estimate of the thicknesses of the several sub- divisions of the Upper Silurian rocks of Shropshire is based on the average of three sections from 8.8.E. to N.N.W. across the north- eastern end of the great Shropshire escarpment. One of these passes through the town of Much Wenlock, and the others at distances of about two miles to the east and west. The horizontal distances of the lines of contour from the base of the Upper Llandovery to the base of the Devonian average from 34 to 4 miles or about 20,000 feet ; and taking the general dip at 12°, the total thickness of the Upper Silurian series can scarcely be less than 4500 feet. An estimate of the actual thickness of each of its subdivisions is difficult to arrive at accurately, mainly from the fact that most of the zones, both in mineral character and in the range of species, insensibly graduate into each other, and it is probable that no two observers would fix exactly on the same lines of demarcation. There are perhaps few parts of the country in which the surface features of contours are ruled so closely by their geological structure 102 ZT. Davidson & G. Maw—VU. Silurian Rocks of Shropshire. enabling the eye at a glance to follow all the main subdivisions. Standing on Benthall Edge or Wenlock Edge, the most prominent points in the escarpment, three parallel valleys and two well- marked intermediate ridges can be made out at almost every part of the long line of exposure extending from Ironbridge on the north- east to Ludlow on the south-west, the three valleys corresponding with the soft shales and the two ridges with the limestones. The broad sweeping valley of Ape Dale below the observer to the north-west represents the Wenlock Shale, backed up on its north-western side by the harder beds of Llandovery Limestone and conglomerate forming the base of the Upper Silurian series. The Llandovery beds on the lines of section may be roughly estimated at a thickness of 160 to 170 feet, of which the con- glomerate, closely resembling the Millstone Grit, forms the greater bulk. The overlying Wenlock series attain a thickness of from 2500 to 2800 feet: their principal mass consists of soft shales capped by the Wenlock Limestone, which has determined the beautiful escarpment of Wenlock Edge, overhanging the gentle sweep of Ape Dale, and on the south side forms a regular dip slope into the Lower Ludlow valleys of Much Wenlock and Hope Dale. No clear line of boundary exists between the limestone and shale, for the one imperceptibly graduates and dies out into the other. From careful measurements made on Benthall Edge we have ascertained that the compact limestone is from 80 to 90 feet in thickness, and it thickens somewhat in the direction of Wenlock to the south-west. Below the compact limestone rock it becomes inter- stratified with thin layers of shale. Still lower down it assumes a concretionary structure, and gradually dies out into soft shale, through increasingly distant nodular courses, at about 400 or 500 feet below the crest of the limestone ridges. On Benthall Edge the Wenlock Limestone dips from 15° to 20° S.S.W.; tothe westward the dip decreases to from 10° to 15°, and at the eastern extremity of the escarpment at Lincoln Hill, near Coal- brook Dale, the inclination increases to from 45° to 50°. The upturn- ing may have been continuously gradual or interrupted. It commenced before the Carboniferous period, for the Coal-measures rest upon it unconformably, and it continued subsequently, indicated by the fact that the inclination of the margin of the Carboniferous beds is related to the greater or less inclination of the subjacent Wenlock Limestone. The following proposed subdivision of the great mass of Wenlock Shale, which at the north-eastern end of the Shropshire escarpment, attains a thickness of from 2000 to 2200 feet, has been suggested by the alternation of zones of highly fossiliferous and comparatively barren strata. As stated above, there is an insensible gradation between the Wenlock Limestone proper and the Wenlock Shale, the shales under the limestone containing scattered concretionary courses of ‘nodular limestone, and it will be convenient to term this intermediate T. Davidson & G. Maw—U. Silurian Rocks of Shropshire. 103 zone “The Tickwood Beds,” which may be roughly estimated to include a thickness of from 300 to 500 feet of strata. They are exposed in the deep road-cutting near the railway bridge between Tickwood and Farley Dingle. There is also a fine natural exposure 24 miles to the east, by the side of a small stream flowing down the east end of Benthall Edge, opposite Ironbridge ; and most of the adjacent cutting on the Severn Valley Railway passes through the base of these nodular limestones and shales. The 'Tickwood Beds are highly fossiliferous. They contain all the five species of Spirifer found in the Upper Silurians of Shropshire, with a larger proportion of individuals than in any other zone. The Tickwood Beds are also the highest horizon in which the new genus Glassia occurs, and Orthis biloba here attains its highest limit, with the exception that a few individuals occur rarely in the Wenlock Lime- stone and Lower Ludlow. Below the fossiliferous Tickwood Beds, from 1800 to 1900 feet of soft shales occur, which are comparatively barren in organic remains, excepting only that at one-third from their base a remarkably rich zone occurs, the horizon of which seems to correspond closely with that of the Woolhope Limestone of Herefordshire, and possibly of the Barr Limestone of Staffordshire, though in Shropshire the calcareous element is wanting. It is exposed on the east bank of the River Severn, a short distance above Buildwas Bridge, in a section in- cluding from 70 to 80 feet of shale beds, which we propose to call “The Buildwas Beds.” They are also exposed further to the west by the side of the brook south of Harley. Just above the fossiliferous zone of the Buildwas Beds, the monotonous ‘“‘ Mudstone ” character of the Wenlock Shale is broken by the occurrence of a few thin bands of a remarkable cream-coloured clay, resembling steatite in texture. The late Mr. David Forbes made for one of us an analysis of these bands, which were found to consist of AWiabersanrte cs eirntts cdsic seimeye ar: 13°88 Carhoule NGC pines Ad siaseeaaee ee \ SS eloonGarhonntoo lane. LIMO fsrencysroe eaxch a eeesora ie aaedemenas 6°22 Silica ane petal reas 45°48 JAUTEYS 8 he ooo eRe RO ODE 23°52 Protoxide of Iron .......... 1:76 Protoxide of Manganese ...... 0:07 IW TSINGRIE, hninalgdagadnces Hobe 1°44 A OLASHMN At hurts ey A ental = 0 2°15 DOG aNee ret tor Aa pen Cig. 28 oe 0:54 99°94 and remarked on the smallness of the per-centage of magnesia in the mineral, which so closely resembles compounds which, from their unctuous feel and external characters, are usually considered to be highly magnesian. The pale colour of these bands is evidently due to the occurrence of the iron in a state of protoxide, which may perhaps have resulted from the presence of the deoxidising agency of organic matter. If we place the Tickwood Beds as forming a connecting link 104 T. Davidson & G. Maw—U. Silurian Rocks of Shropshire. between the Wenlock Limestone and the Wenlock Shale, the re- mainder of the shale may be subdivided as follows :— Barren Shales of Coalbrook Dale and Ape Dale, or ‘‘ Coalbrook Dale Beas Pie, Gee eth ey Ae ip GLe RW AEE Sh SURE eee 1100 to 1200 feet Fossiliferous zone of Buildwas, or ‘‘ Bauildwas Beds”’ ........ 80 to 100 ,, Barren Shales of Buildwas Park, or ‘‘ Basement Beds’? ....... 500 to 600 ,, These soft shales have largely determined the configuration of the contours of the district, and represent the sweeping Ape Dale valley of denudation, which spreads out for twenty miles below the supporting ridge of Wenlock Limestone of Wenlock Edge, and have in Coalbrook Dale yielded to the excavation of that picturesque valley. Some soft shales, about 100 feet thick, overlying the Wenlock Limestone, and exposed in cuttings by the side of the railway between Buildwas and Wenlock, west of the Bradley Lime Quarries, may also pertain to the Wenlock series: in physical character they more nearly resemble the shales of the Wenlock than the overlying Ludlow Beds. The Wenlock Shale in Shropshire, which cannot be much less than 1800 to 1900 feet in thickness, has a development much in excess of the Wenlock shale in the Malvern district, where Professor Phillips estimated it to be 640 feet thick; indeed, its thickness in Shropshire is greater than in any other district, unless we except its supposed equivalents, the Denbighshire Flags, which Mr. G. Maw believes will be found to belong to a distinctly lower horizon. The Ludlow Series.—Any definite estimate of the relative thick- nesses of the several members of the Ludlow Beds is difficult to arrive at, as at the eastern extremity of the Shropshire escarpment the Aymestry horizon is ill-defined, here and there represented by isolated thin bands of limestone, and again as thick masses of impure concretionary limestone intermixed with shale. Collectively the Ludlow series attains a thickness of from 1200 to 1400 feet, which the Aymestry band divides nearly equally, the Lower Ludlow being a little thicker than the Upper, and consists of softer shales. The Upper Ludlow Beds, as at Burton, near Wenlock, often assume the character of fissile Tile-stones. The Lower Ludlow Beds are exposed in cuttings of the Wenlock Railway between Wenlock and Presthope, and the very base of these beds are seen in the Wenlock Railway east of Wenlock. The equivalent of the Aymestry Limestone is finally exposed in the road-cutting below the Dunge House, near Broseley, and to the west of the Marsh Farm on the high road between Broseley and Much Wenlock. The Upper Ludlow is to be seen by the road-side at Burton, near Wenlock, and is also exposed in Willey Park, and in the bottom of the valley below the Dean Farm, near Broseley. The beds connecting the Upper Ludlow with the Old Red Sand- stone, which are well exposed on the banks of a little stream known as Linley Brook, two or three miles south of Broseley, have been described by Messrs. Roberts and Randall in the Quarterly Journal T. Davidson & G. Maw—U. Silurian Rocks of Shropshire. 105 of the Geological Society of London, vol. xix. p. 229. The upper part of their section given at p. 252 appears to refer to the base of an outlier of the Coal-measures, and the remainder to the base of the Old Red Sandstone and top of the Upper Ludlow. The red micaceous marls in the road-cutting on the Bridgnorth side of the valley clearly belong to the Old Red Sandstone, and these are, we suppose, represented by the bed “c” in Messrs. Roberts and Randall’s section. Below this the section is described as follows :— ft. ins, d. Light-coloured grits, with plant-remains.......0.....seeseeeeeee 20 0 e. Hard micaceous grits, somewhat flaggy, and charged with fish remains (‘‘ THe Upper Bonz BED.”’) ..........ceeece cree 7 0 j- Elagstones bearing current markings ...........0csecesssssveee ig g. Micaceous sandy grits with Linguwl@ ..........cece reece rene’ 0 11 h. Greenish irregularly laminated rock with conglomerate............ 1 0 i. Hard calcareous grit with thickly disseminated greenish grains and TMB ROE WOT oqotood copn00 be00 ncoB0b 60000000 DO0b0n 0 k. Laminated light grey micaceous and sandy shales ..............+. 20 0 i Cissy WUGACZOUS FABNIS doo aengdos0 46000000 000000 050000 000000 0 6 m. Micaceous sandy clays coloured by peroxide of iron .............. 6 0 n. Yellow sandstones (Downton series), with Beyrichia, Lingule, and including two or more ferruginous bands, containing large quantities of the dermal studs of Thelodus, fragments of Lingule, and minute crystals of quartz. Clusters of Modiolopsis complanata occur at the base of this rock (THr LowrrR on Luptow Bonz BED) ........ 8 0 o. Hard calcareous shales with fish-remains, Lingule, etc. ......+00 6 0 . Flaggy beds of impure limestone, with Serpulites longissimus, true Woda Jbmilly Peo a nan pOman conrad so eadce Maman Orne OOo ear 4 0 g. Hard impure limestone, Aymestry series, at base. These are without doubt the passage-beds connecting the Devonian and Silurian series; and the only exception we take to Messrs. Roberts and Randall’s determination is the supposed occurrence of Aymestry Limestone at the base of their section, as, judging from the thickness of the Upper Ludlow Beds in neighbouring sections, it is improbable that the Aymestry Limestone would come within the section here exposed. Of Brachiopoda, we believe no species have been found in the Linley Brook section, except Lingula cornea, which is abundant. General Results of the Washings.— The extensive washings and hand-picking from rocks and shales of the Wenlock and Ludlow series in Shropshire has enabled us to ascertain to what horizon each species is peculiar or what was its stratigraphical range. Of course we limit our conjectures to those species of which we have positively ascertained the presence in each horizon. Some few of them may perhaps occur in horizons not indicated in our table, but as they have not come to our knowledge are necessarily omitted. A glance at our table will show that species were more numerous during the Wenlock than the Ludlow period, that is to say, that while 66 species have been collected from the Wenlock series of Shropshire, only 37 were found in that of the Ludlow period—22 being common to both epochs. These numbers are the result of our personal investigations, but may be slightly modified hereafter or upon still more extended research. 106 ZT. Davidson & G. Maw—U. Silurian Rocks of Shropshire. r | (a5) Old Red Sandstone. $ 5 Ss (éD) L R _ Passage Beds. Q * Upper Ludlow. TinleysBrooks) 3 3 GorerDalewn i Aymestry Limestone. (3 12 y 8 ® TRB ee Lower Ludlow. ~ 2 S Tavis N ee) Ss, L 64 © Shales overLimestone. Lal nb) ie ¥ re & Wenlock Limestone. 2 Au a a ny) 3) © S yi] ‘Tickwood Beds. S| rm 3 Lane’s Rough. —------~ 1 Upper Wenlock Shale. = Gy 2 L. 3 ae : Ora = Ss iS z i) Hope Dale. — ------------ 8 a ~~ XN ay 3 Much Wenlock. ---------* ro iS (ea a Coalbrook Dale Beds. ‘“S | As Middle WenlockShale. < a S 3) ae Shee Z « Benthall Edge. —..- : is 3 Wenlock Edge. -.--- | Buildwas Beds. aS S q fa 3 Coalbrook Dale. ------------» ; a ae Basement Beds. ay Lower Wenlock Shale. P ey - Pentamerus Limestone * | Buildwas Abbey. ---------------- | ||. Upper Llandovery. Ss 0 Harley. Bes f Llandovery Con- S S O Ape Male: yi) jets a glomerate. S = : Buildwas Park, ------------------ Merrish Wood, ---—----—------ f Caradoc Sandstone. Stone House. .....------ Lower Silurian G. Maw, delt N.N.W. T. Davidson & G. Maw—U. Silurian Rocks of Shropshire, 107 The common or abundant species seem generally to have enjoyed the largest vertical stratigraphical range. For example, Orthis biloba may be regarded as one of the most abundant species in the Wenlock series, occurring also in diminished numbers in the Lower and Upper Ludlow. ‘The chief horizon, or where it swarms, is the Lower Wenlock Shales or ‘“ Buildwas Beds,” where we have estimated that upwards of 4500 specimens may be obtained from the washing of a square yard of Buildwas Shale. And from seven tons weight of this shale not less than 25,000 specimens of the shell were obtained, and a vast number more were lost through the wash- ing operations. Orthis elegantula is very abundant both in the Wenlock and Ludlow series, and occurs in no less than nine horizons, but most abundant in the Wenlock Limestone and Shales overlying and underlying it. Orthis hybrida swarms throughout the Wenlock series. O. Lewisii is likewise found to possess an extended range from the Lower Ludlow down to the Lower Wenlock Shales. The other species of the genus are much rarer and have a limited vertical range. Of the interesting small Streptorhynchus nasuta a single specimen was found by the Rev. H. G. Day in the Wenlock Limestone of Benthall Edge. Among the Strophomenide, St. rhomboidalis alone enjoys the greatest vertical range, and is at the same time the most abundant species of the group. Leptena transversalis and especially L. segmentum are very abundant species, while Chonetes lepisma swarms in the shales above the Wenlock Limestone, but has not hitherto been found in Shropshire at any other horizon with the exception of that of the Lower Ludlow. Next to Orthis biloba, Atrypa reticularis is the most abundant species throughout the Wenlock series, and is likewise very common in the Lower Ludlow and Aymestry Lime- stone. Atrypa Barrandi is a very abundant Wenlock species. Meristella tumida possesses an extensive vertical range. Five species of Spirifera have been collected, but of these the small Sp. crispa is the most abundant; it swarms in the Wenlock Limestone, and especially in the shales that underlie it. Nucleospira pisum is a very abundant species in four horizons of the Wenlock series. LRetzia Salteri and especially Retzia Bouchardi are very common species in the Wenlock Limestone and its Shales. Among the Rhynchonellide, Eh. borealis is immensely abundant in the Wenlock Limestone and in its underlying shales, while Rhynchonella Wilsoni is most abun- dant in the Ludlow rocks. It is also worthy of remark that while the species belonging to the Clistenterata are prevalent in the Wenlock series, the reverse takes place for the Tretenterata. For example, five species of Lingula occur in the Ludlow series, while two only have occurred to us out of some fifty thousand specimens of Wenlock Brachiopoda, Lingula Symondi and Orbiculoidea Forbesti being the only abundant species in the Wenlock series, and these apparently almost restricted to the Lower Wenlock Shales. A glance, however, at the table (see over-leaf, pp. 108 and 109), will obviate the necessity of further remarks on this subject. The 81 species recorded in our table belong to some 22 genera. 108 ZT. Davidson & G. Maw—U. Silurian Rocks of Shropshire. BRACHIOPODA FROM UPPER SILURIANS OF SHROPSHIRE. GENERA AND SPECIES OF BRACHIOPODA. r Rare. rr Very rare. c r Not very abundant. c Common. cc Very abundant. LINGULA Symondsi, Salter...... 6 —§| Lewisii, Sow. ......... sae SLALOLO SOW te ceace ee MIUMLNA, SOW. .....00-s| «+ LOL IRS ONE Eee A GUUath SOW soo000s06 ORBICULOIDEA Forbesiz, Dav....| ... DISCINA vugata, SOW. .......05+ Bia Morrisit, Day. .....-..- ae SEHLAULE SOW eee ee base PHOLIDOPS ( Crania) implicata, Sowel. wshtouncdeied t Dinosoivus Davidsonz, Salter... WALDHEIMIA Mawei, Dav......- ? ——— _ Gilasset, Dav....... Be MERISTELLA famzda, Dalman...|... didyma, Dal. ..... d\iseo leviuscula, Sow. -.|... ? ————. _Mawe?, Dav. ......| ... SPIRIFERA flicatella, var. vra- diata, Sow. ..... é var. ——— zuterlineata, Sow. crispa, Linné. ...... elevata, Dal. ........ nile sulcata, His........ He CyRTIA exporrecta, Wahl. ..... all c NUCLEOSPIRA fisum, Sow.......|. ATRYPA reticularis, Linné....... if aspera (small var.) Schlothieerserspertccrt 306 ———— mareginalis, Dal. ...... at imbricata, SOW...... seit Larrandi, Dav. ...... ae GLASSIA obovata, Sow. sp. ...-..|... elongata, Dav. .......-+|... LUDLOW SERIES. WENLOCK SERIES. Passage Beds. (Linley Brook.) RusawAWN, Sova MOEN Yo soosooons0se Bouchardi, Dav. ...... ae 1 | Upper Ludlow. cc rr 0) SI S) 5 o 5 Be H | J Ar o oO g 5 > ° we 2 (Ge | © i ° Es] q a} 000 (e a Ge io) » n a ® cer|jcr EOE ie 1g 6 |) (03 (6; Cc cc Cc 6005 is cet cee (it rrjcr r 6 || ag noo || (G oe 9 | 10] 11 12) T. Davidson & G. Maw—U. Silurian Rocks of Shropshire. 109 1 2 4/5 OS ioe i Sy Oy oy ahl pe BIGHWVARDTATE epewell2, Wave | s0|'o0| oo | sey] cae [see | tr se er STREPDIS Grayz, Davy. ........... oned eset Snell Gomet || sss ahl ice pa) |i@ ae PENTAMERUS Knighti, Sow. ...|...|...| ¢ ¢ galeatus, Dal. ......... 290: goa || asa ll) GC CON RC hie linguifera, SOW. ...... 00 || deoi| dogs |) ase, {Il coor In Ik MG I) ace reed. |) a8 RHYNCHONELLA Wilson, Sow.|...| c | c | c c ————. spherordalis, M‘ ae Seer Nisan II sesceual| tonal nicelmy leneeenel [tre op LEE, IDEXG>) ‘ghdcaodso|-ooe| cost eee. || coo. {I oon) te r haraell Schl. GC] Ce ——— bidentata, Sow Bee Medes Koopa nos 500) |G 1), ie r Strickland, Sow. .....- ctevl seo lees eal tigerelss all ceecons ata cuneata, Dal. .. oe o || @ 1 nucula, Sow. | Cc r Dayi, Dav. . GC WOR icce |S v Speyanaknet seoiie . ¢ r SPee sacs asstiees s0q||'00l| dol] aoa" | ead {Il 500" I! co r == Mel Bilt, SOWs oocand000 seal soo |) 66 || 600 {I] coo, | Ct. é ——— (? Atrypa) depressa, a SOW (CeMws wlacsazri}] soa) coc] eae. || eos II! cas ll oooh soo See |e, 38 q (2? genus uncertain) S navicula, Sow. ...|..-| c | ¢ 2 ay OrTHIS b2loba, Linné. ............ scolGPll coo || BE NG rile el Clo. tee 3 —— lunata, Sow............. Sa Om le 2 elegantula, Dal. ...... ca fCE| & TC ri Cl Ci} © ler & ee Hagia, IDES: “cael| eae | "CW ene || 608 ||| coe || acu! GP eG @ 6 hybrida, Sow. j Sllec|/CEleclee|ece a Lewzsi, Dav. neal isaac lls r Yr Y © |e e RB Bouchardi, Dav. ...... Bese sceal bes cuiliiS eesn ll ps@un (GbE es 5 ——— rustica, Sow............. HE eee UN eevallimcees oH iveaer aC RNC Tal Gmelliaie 3 GE MSOMMZ OSS, IDR. s04| S60} s60 |) sco | e00. {I 2006. ||) s60-|! seo. |! “ooo ||| @ fe ass @quivalvis, Dav. ...... dac'|ragar||) saben anol Neadull Sonal) Codd lleoce treme iret ie Gijorata SCliley eeeeeee: Beale litrenee |p eee tevasietal |i sae oF iS a STREPTORHYNCHUS zasuta, a ADIT. sepeascceeconso|| 061 |'000 | sou.|) coe! fll doo || 3 ae ES STROPHOMENA Dayz, Dav. ...... dap|lobollvese. | Moon aoe ese) Sool/oad {las rhomboidalis, Wilkens} ...|...| rx r soo | CG |G ei] ele we Jurcillata, M‘Coy...... esol} ace} coo || i |i @se) i r euglypha, SOW. ......... zal sey cee r CELATUMG, SOW socoaoll 04 || c00 |} o56 fy B00 Il 600 | tmbrex, Pander..... ... Boo | BON ecb there tal Mooeal aeeetel Mercia) li ceenn hese ———— fecten, Linné. ......... ecto |e esesee | reateesan Neel tes oe ues ain ese lbu Jilosa, Sow. 260] 'C!|| r ornatella, Salter ...... eco || © Liletcheri, Dav. ......... S80 hana 'lledgdelMedae || MBean Mae LEPTANA, transversalis, Dal. e00 | doo {|=c60' || "600: Mf’ coe] doo KG el] Se. W)C r seementum, Angelin |...|...; ...|cr},... | r | ¢ | ¢ lee ——.— /evisata, Sow. -....-... B60\l| doo || boa" |}. CHONETES /episma, Sow.......... 366 sao] ado! © WEG munima, Sow. . Soq|000|M cen |) ae: |} 4e'Fe as 1 3P striatella, Fischer . Bocce dun || || © © (Zo be concluded in our neat Number ) 110 Prof. J. D. Dana—Metamorphism of IJJ.—On a Case IN WHICH VARIOUS MASSIVE ORYSTALLINE Rocks INCLUDING SopaA-GRANITE, Quarrz-DiortrE, Norirr, Horn- BLENDITE, PYROXENITE, AND DIFFERENT Curysouitio Rocks, WERE MADE THROUGH METAMORPHIC AGENCIES IN ONE MurETa- MORPHIC PRocgss. By Prof. Jamus D, Dana, LL.D., A.M., For. Memb. Geol. Soc. Lond., of Yale College, New Haven, Ct., U.S.A. Part II. (Continued from page 65.) B. Tur RELATION oF THE CorTLAND Rocks TO THE OTHER Rocks oF WEST- CHESTER CouNTY. HE above brief description of the Cortland rocks prepares the way fora consideration of their relation to the other rocks of the county. The following questions arise: Are they one with the latter in system ? are they rocks of an earlier system? or are they eruptive rocks, and not metamorphic, and hence, of no bearing on the general question as to the age of the Westchester limestones and the asso- ciated schists ? 1. Evidences of more or less Complete Fusion. The evidences of fusion or plasticity are many; and, taking them collectively, they are decisive. They are exhibited in the following ways: (1) The massive character of the crystalline rocks over so large an area, and a general resemblance in them to igneous rocks ; (2) the great size of the hornblende crystals in some of the quartz- diorite, and the well-defined crystals of hypersthene in part of the norite, resembling the augite crystals of some volcanic rocks, facts indicating freedom of molecular movement during the process of crystallization; (8) the broken condition of the crystalline indi- viduals in some places, which is evidence of movement while in a pasty state after the beginning of solidification; (4) the occurrence in the massive rocks of included fragments of other rocks, like the inclusions in many trap or basaltic ejections: (5) the existence of dykes or veins of the hornblendic and other rocks, of very various sizes, intersecting the adjoining rocks. The inclusions are remarkably numerous in some portions of the region, and are often of wonderful magnitude. About Cruger’s station, in the soda-granite and quartz-diorite, they occur from an inch in breadth to many feet; one seen in the face of a bluff on the railroad, between three and four hundred yards north-east of Cruger’s station, has a maximum breadth of eighteen feet and a length but little less, and consists of garnetiferous mica-schist like that within a fourth of a mile to the east and south; and this is not the largest in that region. They abound also in the chrysolite rocks and norite of Montrose Point and Stony Point, and in the limestone of Ver- planck Point. They usually consist of the various materials which constitute the schist of the vicinity, even to the magnetitic garnet rock, quartzite, ete. Massive Crystalline Rocks. NGL Figure 3 represents (z4; of the natural size) an example from the 3. soda-granite, half a mile ie west of Cruger’s, where displaced fragments of a thin layer of mica-schist occur in the granite. Fig. 4 (;z the natural size) is of an inclusion in the norite of Montrose Point; the distorted form, the fractures, and the faults appear to be evidence of former free movement in aN the massive norite. Fig. \ 5 represents a surface three feet square from a large brecciated pyroxenite adjoining directly the crystalline limestone on the shores of the Hudson at Verplanck Point. The masses in this strange breccia are contorted frag- ments of the limestone, one or two feet long, the thin layers of which have been brought out prominently by surface erosion. The examples of what appear to be veins or dykes are also numer- ous. They cut through the chrysolite rock and norite of Stony Point and Montrose Point, and through the crystalline limestone of Verplanck Point. Those at the last-mentioned place, facing the river (north of the foot of Broadway), vary from an inch in width to over fifty feet. Some are simply faulted bands, like Fig. 6. Others have more irregular courses, as in Fig. 7, representing eight feet from a vein at Verplanck Point. Fig. 8 shows a crossing of two small veins from the same limestone region. Some, if not all, of such veins must, therefore, be true veins or dykes; and are evidence as to the former fused or plastic condition of the material and its injection into fissures. Veins formed in this way are not veins of 112 Prof, J. D. Dana—WMetamorphism of infiltration or segregation, that is, they are not due to the filling of fissures by material supplied slowly in solution or vapour; for no difference in coarseness of texture or structure exists between the rock constituting them and that of the massive rock elsewhere ; they are just such as have heen made by simple injection. There are also peculiarities in the exterior of inclusions, and in the walls of veins or dykes, in some cases, which favour the idea of fusion. At Verplanck, the limestone of the wall is often discoloured for two or three inches, and sometimes penetrated by the material of the vein, or contains miuute crystals of hornblende; and in other cases, the limestone is impregnated with the hornblendic or augitic material in irregular lines or bands, so that surface erosion has left a complexity of small curving ridges. The crystallization of the lime- stone adjoining the vein is sometimes coarser than elsewhere; though, in general, no difference is apparent. Ona small point, just north of the region of veins, part of the limestone is of the coarsest kind, the crystalline grains over a fourth of an inch broad, while the larger part is very fine in grain, like the most of the Verplanck limestone —a fact that indicates the local action of escaping heat. Still more positive evidence, if possible, of fusion is shown at the junction of the schists of Cruger’s Point with the soda-granite, where the schist itself bears evidence of partial fusion and exhibits other contact-phenomena. The proof of the crystallization of the rocks from a more or less perfect state of fusion or plasticity is thus complete. 2. Evidences as to Condition of Fusion. But, admitting fusion or a plastic condition, the question still remains: Were these once-fused rocks fused approximately in situ, that is, where, or near where, they now lie; or were they erupted through fissures from great depths below? that is, using Dr. Hunt’s terms, are they indigenous, or are they exotic? a. The results are partly the same whichever the condition of fusion. —If they were fused where approximately they now lie, that fusion must have come from accessions of heat, and such accessions may have resulted from the movement and friction connected with an up- turning of the rocks; and it may hence have been one of the results, in that region, of metamorphic action at an epoch of general meta- morphism ; and if so, at the very time that these rocks became fused or plastic through the process, other rocks of the region, owing to less extreme metamorphic action, or to less fusibility, may have been left with their bedding unobliterated; just as much granite in New England and other countries received its crystalline condition in the same process and at the same time with the associated schistose rocks, the gneisses, mica-schists, etc. All the facts as to fusion which have been presented are consis- tent with either mode of origin, even to the inclusions and the dykes or veins. (1) The veins or dykes have the same essential characters whether Massive Crystalline Rocks, 115 made one way or the other. As has often happened in the case of granitic rocks, and even granular limestone, the fused or plastic material, under the pressure attending the subterranean movenients, would have entered and filled all fissures that might have been opened to it, and so have made veins or dykes having the sizes of the fissures, whether large or small, and possessing also a uniformity of grain like that of ordinary erupted rocks. (2) Again, whatever the process of ejection, fragments, large or small, of any rocks adjoining such fissures might have become in- cluded in the fused or plastic material. (3) Moreover, the contact-phenomena in the case of veins so formed may be as decided and extensive as in that of any dykes or erupted masses. (4) Further, the evidences of fluidal movement exhibited in the broken condition of many of the crystalline grains would be the same. Sucha fragmenting of grains taking place after the stiffening of incipient solidification requires but a moderate amount of move- ment, and this is all that such circumstances would admit of. One foot would suffice; thousands would be impossible. (5) Again, the resulting rocks need not, and generally do not, differ in kinds from erupted rocks of deeper source. In such fusions in the course of a process of metamorphism, the thickness of the rocks undergoing common movement may have a depth of 20,000 feet or more, and the fusion, therefore, would not be superficial. The view that many of the ordinary erupted rocks are nothing but fused sedimentary rocks need not be here discussed. The improba- bility of the view comes from the improbability of any movements in the earth’s crust being sufficient to fuse its own rocks or the over- lying sediments. But the epochs of metamorphism are the times not only of the profoundest movements of the crust, but also of the most thorough upturning of sedimentary beds, and if these are ever melted through the friction of upturning, or by its aid, then would be the occasion for it. (6) Veins made at such an epoch by the injection into fissures of any rock so fused might have any extent, even that of the whole depth of the rocks metamorphosed; for the fissures may be thus deep. And the material filling them, since it might be that of the bottom rocks, might be wholly unlike that of the rock on either side of all the higher parts of the fissure. But while there may be these resemblances between the effects of metamorphism and those of deep-seated eruption, b. The results of fusion of sedimentary beds under metamorphic action may have distingushing peculiarities.— First: The kinds of rocks so resulting are likely to vary greatly at comparatively short intervals, because sedimentary beds often vary thus. They should not have that uniformity for scores or hundreds of square miles 1 Tn the writer’s Manual of Geology (1880), veins of this kind are called veins of plastic injection, an abbreviation of the full statement that they were made by the injection of material rendered plastic or fused during a process of metamorphism. They are better called dyke-like veins. DECADE II.—VOL, VIII.—NO. III. 8 114 Prof. J. D. Dana—Metamorphism of which often characterizes ejections that have come up from regions beneath the supercrust.' Sediments, and therefore sedimentary deposits, are liable to frequent and sudden changes as to material, which igneous outflows cannot imitate. Secondly, the rocks are likely to have no columnar (basaltic) structure; because the fractures to be filled in such cases are fractures in rocks which are participating in the movement, and which, therefore, are heated rocks, and not cold. Again, the phenomena of contact and the facts as to inclusions, structure and superpositions, may have distinctive peculiarities. ec. The condition of fusion or plasticity in the Cortland region.— To answer the question before us we have, therefore, to consider more closely than has been done the phenomena of contact of the schistose with the massive rocks over the Cortland region, the peculiarities of some of the inclusions, the characteristics of some of the so-called veins or dykes, and the characters of the rocks as to their transitions, structure, and relative positions. 3. Special Facts from the Cortland Region. a. Contact-phenomena between the schistose and massive rocks; facts connected with the inclusions ; stratigraphical relations to the limestones.—The facts with reference to inclusions and all contact- phenomena bear directly, as will appear, upon the question as to any stratigraphical relation in the Cortland rocks to the limestones ; and they are, therefore, here taken from the vicinity of particular limestone areas. (1) The vicinity of Cruger’s limestone area.— The small lime- stone area near Cruger’s (see map) lies mostly to the south and east of the station; only a small portion about forty feet in greatest width borders the river west of it, beyond the first brick- yard (l), the rest of the westward extension of the limestone being beneath the river. The schistose rocks directly and con- formably adjoin it on the north, the average strike of both being N. 70° EH. and the dip 75° to the northward. In the south-eastern portion of the area there is a twist in the whole to the north-west. The limestone is finely crystalline granular, mostly white in colour, and over the hills to the eastward contains crystals of white pyroxene. The schist north of the limestone has a thickness of about a thousand feet. ‘Toward the limestone, it is a silvery mica-schist containing a little black mica and an abundance of very small garnets. A hundred yards or so to the north it is staurolitic, the staurolite occurring in grains of a clear chestnut-brown colour and rarely in distinct crystals; and it also in some parts becomes quartzose and consequently thick-bedded. There are, besides, seams containing much magnetite ; and at one place an intercalation of a black micaceous rock containing some felspar which is abuut equally orthoclase and a soda-lime species. After another hundred to a hundred and fifty yards northward, in the course of which it becomes increasingly staurolitie and garnetiferous, and passes in 1 The term sxpercrust is used for that part of the earth’s crust which has been made by sedimentation, the trwe crust being restricted to the part beneath which is a result simply of cooling. Massive Crystalline Rocks. 115 places into a true gneiss, it comes to its end against soda-granite and quartz-diorite. Thus within a breadth of only 250 to 350 yards, there is here a passage from a stratum of crystalline limestone through conformable schists, to the massive rocks along which we have to look for contact-phenomena. The facts here described are mostly from three south-to-north sections: Section 1, 300 to 400 yards west of the Station (/ to n, on the map) ; section 2, about 700 yards (p) ; section 5, about 900 yards to s). as ee 1,7 to m is the schist; at m is soda-granite, which becomes hornblendic twenty-five feet above, toward the road; and then at n, on the north side of the road, the rock is of coarse quartz- diorite. (The locality u is that of the first outcrop of rocks on the road going north-west from the railroad station.) The contact- phenomena in this section are as follows. In the first place, the mica-schist is even in bedding against the limestone ; becomes more and more contorted to the northward, or away from it; and is full of flexures of a yard or so in span for the last fifty feet or more south of the junction with the granite. With the increase in the flexures of the layers, the schist becomes interlaminated with nodose-lines of quartz, vein-like in origin; and, besides, the garnets become somewhat larger. At the junction referred to, the schist is mostly a garnet rock containing much fibrolite and staurolite, and the latter is in some places granular- massive ina small way. Just below the granite, the layers are a compact body of flexures, and in the soda-granite there is another flexed layer rather faintly indicated. Figure 9 represents the condition here described; it was taken from the west side'of a little bluff at m; the height is twenty feet. The dotted portion is that of the soda-granite. The garnet rock of the flexures under the granite contains, like the granite, soda-lime (or triclinic) felspars, with little orthoclase; and the first foot of Fie. 9. Fie. 10. the granite is strongly garnetiferous ;—facts which show a degree of transition in the material of the two rocks. The flexed bed within the soda-granite is gneissoid in character and of darker _ @ 116 Prof. J. D. Dana—Metamorphism of grey colour than the granite; it is quartzose and garnetiferous, strongly micaceous with black mica, and contains magnetite and a little staurolite. The schist is consequently not a schistose por- tion of the granite, but a distinct bed; it is like the schist in its minerals, but in its more gneissic character indicates that it is intermediate between the schist and the soda-granite. The eastern face of the same ledge is about a dozen feet to the east of the western, and here the junction of the schist with the granite looks more abrupt, but partly in consequence of erosion; above this plane of junction, in the mass of the granite, distinct though fainter indications of flexed beds exist. The change above m from soda- granite to quartz-diorite is simply a change in the substitution of hornblende for the larger part of the black mica, the felspars being equally triclinic in the two, and the quartz equally deficient in amount. Atasmall bluff, 160 yards to the west of m (at 0, see map), the change is more abrupt than between m and n; in only six feet, the rock passes from soda-granite to diorite. ‘A natural inference from the series of facts presented in this section, those as to the flexures in the schist as well as the changes at the junction of the schist and granite, would be that the heat of metamorphism increased from the limestone northward toward the granite and diorite region, the heat being a consequence in part, if not chiefly, of the movement and friction attending the flexing, and that consequently there was produced a more and more yielding condition in the material of the schist as the region of complete fusion was approached, and, at the junction, perhaps a fusing and obliteration of portions of some layers of the schist; and that a bed of schist existed in the granite which approached somewhat the granite in character, but which, owing to the nature of its material, was not wholly obliterated. But, are not these flexed portions of beds fragments that were broken off and carried up by the fused or plastic material as it rose from depths below? They lie so conformably to the flexures of the schist as to suggest a negative reply to this query. Sections 2 and 8 (at p, and qr s, on the map) show inclusions on a grander scale. Section 2 extends up the face of the first high bluff of bare rock west of m (a bluff that has by its east foot a path leading up among the trees to a fine spring). Figure 10 represents a portion of the surface of the bluff about forty feet wide. Below is the hard contorted schist, a well-bedded micaceous schist, becoming in its upper part true gneiss; and above this, as the dotted surface shows, there is soda-granite, and then, after a few yards of this rock, the diorite or hornblende rock, which is indicated in the diagram by short lines instead of dots. About a yard above the schist, within the mass of the granite, a schistose layer, about a foot thick, occurs; and eight to nine feet above this another ‘wn the diorite, and both are conformable to the schist. The upper bed of schist shows (in thin slices) that it is a ‘quartzose, daik-grey gneiss, containing much black mica and Massive Crystalline Rocks. eli, garnet, but also much triclinic felspar and apatite, and in these two points approaching the soda-granite,—thus evincing a very marked transition in its composition toward that of the soda- granite. The first bed above it, lying in the granite, is similar to the schist in its black mica and quartz, but contains very little garnet; but like the soda-granite, it contains much apatite and more triclinic felspar than orthoclase. Still other parallel beds are-indicated at higher levels; one of them exists at the top of the bluff, twenty-five to thirty yards above the upper bed in the figure. The facts look toward the same conclusions as those from section 1. Section 3 was taken along a line about half a mile west of Cruger’s Station, commencing on the river at g (see map, p. 60), in front of the most western of the brickyard sheds, and passing r, a point north of the upper shed, to s. For a distance of about 500 feet from the shore, the rock is mica-schist; next follows soda-granite for about fifty feet; then, very coarse diorite (the hornblende crystals in some parts finger-like in size) for 90 to 100 feet; then soda-granite again. At the shore the schist is nearly evenly fissile; 450 feet north, on the line of the section, it is like the six feet square represented in Fig. 11. In the next fifty feet, Fie. 11. the flexures are distinct, but half faded out or nearly obliterated ; and this is the last step before the soda-granite, the once plastic or fused rock, begins. _ After twenty-five feet of soda-granite the first (a) of the ranges of “inclusions ” appears ; it is on the side of the road which here leads 118 Prof. Dana—MNetamorphism of Massive Crystalline Rocks. up the slope. Between three and four yards of the band are repre- sented in Figure 12. As shown, it is in pieces; yet the pieces are not much displaced, which they would be in an erupted rock. The material is greyish-black, and consists of a very chloritic magnetite, with a little black mica, in a feeble amount of base of triclinic fel- spar. After an interruption it appears again for a short distance to the westward, where it is much more micaceous and garnetifer- — ous; but the exposure is not as .:] satisfactory as in the case of the 41 other bands. Three feet behind | this band, that is, to the north, | there is a similar one having = a parallel position. Hight or nine yards north commences the coarse diorite. At the top of the slope, near the passage of the coarse diorite to the soda-granite, partly in the diorite but mostly in the granite, there are three bands (b) within three to five feet of one another, gneissic in constitution. Figure 13 repre- sents about a dozen yards of these bands, in the diorite and granite. Fig. 12. Fie. 13. Fic. 14. --lo- SO 2 GIS The upper or northern of the three bands (6°) is exposed with small interruptions for a length of more than one hundred and fifty feet; and the more eastern portion is shown in Figure 14. ‘The strike is the same as that of the schist. The rock of the middle of these bands (b?) is a quartzose gneiss, with black mica, many visible grains and octahedrons of magnetite, and some garnet—resembling the gneiss of some of the nearest schist and unlike the inclosing soda-granite in its excess of quartz, mag- netite, and its garnets; and that of the others is similar. About three yards north, but a little to the west, is another band (b'), one to two inches thick, which has a grey colour, and consists of small spangles of silvery mica, some scales of black mica and chlorite, and grains of magnetite—a thin layer of the mica-schist more magnetitic than usual. About eight yards north of the third of the bands represented in Tigure 12, there is another schistose band (c), which is short in the line of the section, but appears again to the eastward and also to the westward ; the rock is quartzose, garnetiferous, and includes chloritic magnetite with fibrolite, and other materials of the schist. W. H. Hudleston—The Yorkshire Oolite. 119 Hight to nine yards farther north, in the soda-granite, another band (d) exists, with the same strike—that of the schist—which outcrops for two hundred feet, or as far as the rocks in the direction are uncovered. This band is grey, like the last, and sparkles with the same pearly mica, but it is made up largely of brown staurolite in a half-granular form, showing but rarely crystalline faces, and contains also disseminated magnetite and some fibrolite and chlorite; a garnetiferous portion contains much black mica. Hight feet farther north, but to the eastward a few yards, a very siliceous schist appears for a short distance. Fifty feet north, in the soda-granite, is still another band (e), which contains much chloritic magnetite; and a hundred feet beyond, another thin, grey, micaceous band resembling closely 6!; the condition of a portion of it is shown in Figure 3, on page 111. Farther north, at intervals, other schistose bands exist, and along the north side of Cruger’s Point, facing the brick-yards at the foot of Park-street, they are more largely displayed. (To be concluded in our next Number.) TV.—ContTRIBUTIONS TO THE PALMONTOLOGY OF THE YORKSHIRE OouiTEs.! Parr VII. By Witrrip H. Hupuxston, M.A., F.G.S., President of the Geologists’ Association. (PLATE IV.) Genus Trocuoroma, Deslongchamps,’ 1842 = Ditremaria, D’Orbigny, in part. In England the Great Oolite of Minchinhampton contains the greater number of species belonging to this peculiar group of Haliotide. Morris and Lycett (Great Oolite Mollusca, p. 80) give a full and interesting diagnosis of the genus, which has only one representative in the Corallian beds of Yorkshire. D’Orbigny figures half a dozen species of Trochotoma from the Corallian of France, and Buvignier gives three from the Coral Rag of the Meuse. None are quoted by De Loriol from the Séquanien of Boulogne. 49,—Trocuotoma ToRNATILIS, Phillips, 1829. Plate IV. Figs. la, b. Trochus tornatilis, Phillips, 1829, Geology of Yorkshire, vol. i. pl. iv. fig. 16. Trochus discoideus, Roemer, 1836, Ool. Geb., p. 150, pl. x1. fig. 12. Trochotoma discoidea, Roemer, 1850, Morris and Lycett, Gt. Ool. Moll. p. 84. pl. x. fig. 10. Trochotoma discoide, Buy., 1852, Stat. eéol. de la Meuse, p. 39, pl. 24, figs. 10-11. Ditremaria amata, D’ Orb., 1852, Terr. Jurass. vol. ii. p. 389, pl. 343, figs. 3-8. 1 Concluded from the February Number, p. 59. 2 T am indebted to Professor Morrisfor the following note with reference to the authorship of this genus :—‘‘ Described by Deslongchamps in 1841, and first published in the Mem. Soc. Linn. Norm. vol. vii. 1842. Lycett sent the proposed name with a specimen to Sedgwick in 1841, but without any description. ‘he first description by Lycett appears to be in the Annals and Magazine ot Natural History for 1848, 2nd series, vol. iil. p. 253, and more fully in the Great Oolite Mollusca, 1850. It would seem therefore that Deslongchamps has the priority of publication. S. P. Woodward in his Manual assigns it to Lycett, although both authors suggested the name T’rochotoma about the same time, 1841-42,” 120 W. H. Hudleston—The Yorkshire Oolite. Trochotoma amata lab) 18—, Deslongchamps, Notes palwont., No. vi. p. 46, . 8, fies. 3-6. Trochotoma tornata, Phillips, 1875, G. Y., 3rd edition, p. 359. non Pleurotomaria tornata (Phillips), D’Orb., op. eit. p. 564, pl. 422, figs. 6-8. Bibliography, etc.—It is certainly stretching the rule of priority to the utmost when we adopt Phillips’s name for this very widespread and somewhat persistent species. As there is no other species of Trochotoma in our Yorkshire beds of this age, it is pretty clear that Phillips’s most inadequate figure was intended for the fossil now under consideration. If, however, this figure, unaccompanied as it is by any description, be rejected as insufficient to establish Phillips’s claim, we must fall back upon Reemer’s name of Trochotoma discoidea, which is in every way preferable. D’Orbigny (Prod. de Pal. Strat. vol. i. p. 354) quotes Trochus discoideus, Roemer, as an Oxfordian fossil, and subsequently (op. cit. vol. i. p. 9) quotes Ditremaria amata, D’Orbigny, from the Corallian. In the Terrains Jurassiques he makes no mention of Roemer’s species, but regards the T’rochotoma discoidea, Buvignier, as a synonym of his | : own D. amata. Brauns (Obere Jura, p. 231) regards Buvignier’s species as identical with Roemer’s. Buvignier’s figure and descrip- tion answer excellently to our Yorkshire specimens, which we must therefore identify with the original Trochus discoideus of the Coral Rag of Hildesheim. Description.—Fig. 1b. Specimen from the Coral Rag of North Grimston (Strickland Collection). Helle grit ee ews sosiaetetere auborcas eae keene eR Tere os 12 millimétres. Basal diameters, rstewridruseicie ste toss ade cece 26 » Spiraltanelevaboutyae cree sete creas « 130° Shell very depressed, more than twice as wide as high, largely excavated. Spire composed of about four whorls, which are wide apart, subdepressed in the early stages, and very much so in the body-whorl, which is large in proportion to the rest of the spire. The ornaments consist of regular raised lines parallel to the suture (i.e. transverse), and these lines are cut across from left to right by a system of fine striations, producing a delicate pattern. The whorls are bicarinated (a feature not observable in the earlier stage): the posterior keel, which forms the salient angle, contains the fissure. This is elongate, and terminates three millimétres from the present margin of the outer lip, which has been slightly reduced by fracture. The space between the keels is rather excavated, and the anterior keel is rounded off. The same ornamentation is continued in the base of the shell, but the state of preservation does not admit of an accurate description of the aperture. Fig. la.—Smaller specimen from the Coral Rag of Brompton (Strickland Collection). This shell has the general character and ornamentation, of the one previously described, but is less depressed. Moreover, the body-whorl developes wide undulations across its surface, which yield an additional ornament. The imbricated band of the sinus is very well seen in this specimen, situated, as in the other case, on the posterior keel. The termination, where the loop Geol. Mag. 1881. Decade . II. Vol. VIIL. PLIV. A. 5S. Foord., del et lith. Mintern Bros, irnp. Coralhan Gasteropoda. Yorkshire. W. H. Hudleston—The Yorkshire Oolite. UPI should be, is unfortunately not visible, and the base of the shell is wholly obscured in matrix. Relations and Distribution—Some might be disposed to regard the differences between la and 16 as important enough to constitute two species. 16 is an exceptionally depressed form, selected for figuring as the best-preserved specimen which I could obtain. It is entirely devoid of the undulations so conspicuous in la. But we find shells with the outline and dimensions of la quite as devoid of the undulations as in 1b; therefore this can hardly be regarded as a character of importance, though D’Orbigny mentions it in his diagnosis of Ditremaria amata. Again there is great variety in the fineness of the ornamentation, but we cannot trace a connexion between any particular degree of fineness and the development of these undulations. If any constant difference can be pointed out, it is that the Grimston and Langton Wold shells are larger and perhaps more depressed than those from the Rag of the Scarborough district, which more resemble the small variety of this species recognized by Morris and Lycett as rare in the Great Oolite of Minchinhampton. Roemer’s shell, judging from his description, is a smaller and less developed variety, with trom two to three whorls. Brauns finds it in the perarmatus beds of Heersum and Coralline Oolite of Hanover. The species is not quoted from the Séquanien of Boulogne, nor do I know it from the Coral Rag of the rest of England, though it is decidedly common in the Coral Rag of Yorkshire. Genus Pieuroromaria, Defrance, 1825. This genus is not particularly well represented in any member of the Yorkshire Oolites, nor does the Inferior Oolite yield a better list in this respect than subsequent formations. Here therefore we note a great difference between the Inferior Oolite of Yorkshire and of the Anglo-Norman basin, which latter may be regarded as the head-quarters of Pleurotomaria, both in numbers and species. On the other hand, the Corallian Rocks of Yorkshire have furnished as many species as the beds of corresponding age throughout the rest of England, though none of the species described can be regarded as common. 50.—Puevrotomaria, sp. Plate IV. Figs. 2a, 6, ¢. Description.—Specimen from the Passage-beds of the Lower Limestones, Wydale (my Collection). JEGUGHT noc 665 cage uO SUDO OnOOUdD Oba DUG OUOUUC 21:5 millimétres. VAG cs Acie uisige Hoc Ot cee CR In CCG entice 22 * Syoummlll GNSS. oo bedgg oosocuacobodudadds D6oouO GH 74° Shell conical, subturrited, but slightly oblique, scarcely umbilicated. Spire composed of six or seven whorls, which increase regularly and are but slightly angular. Each whorl has only one well-defined keel, which forms the principal prominence, and carries the imbri- cated sulcus. In the penultimate whorl of this specimen an anterior keel is imperfectly developed. The ornaments display considerable irregularity. Above the sulcus of the body-whorl the sculpture is 122 W. H. Hudleston—The Yorkshire Oolite. granular, that is to say, it consists of a system of transverse ribbing, deeply decussated by longitudinal furrows. Below the last sulcus the granular character is less decided, and the base of the shell has numerous fine spiral lines, which decussate with wavy lines of growth. Base rounded and tumid: aperture subquadrate: um- bilicus, little more than a notch: columella short and sloping. Relations and Distribution.—This small variety of Pleurotomaria has features in common with many named forms; and yet, when closely compared with these, it is not found to fit any of them exactly. In Yorkshire it has only been noted in one locality, whence but few specimens have been obtained. This shell-bed lies towards the base of the Lower Limestones, and on the same local horizon with the Gervillia-beds of Scarborough Castle Hill.! It is Oxfordian, and contains several of the fossils of the ‘Oolithe ferrugineuse” of Viel St.-Remy, ete. A very near relation is the Cornbrash species described by Lycett (Supplement to Great Oolite Mollusca, p. 24, pl. 31, figs. 8, 8a) as Pl. granulata, Sow.?, When we turn to foreign authors, it is clear that the Wydale Pleurotomaria has affinities with the Pl. Minsteri group, and especially with the variety Pl. Buchana, d’Orb. (Terr. Jurass. vol. ii. p. 552, and pl. 417, figs. 6-10). Nevertheless, in this case, although the outline and proportions are very nearly the same, D’Orbigny’s fossil from the “Oolithe ferrugineuse” is repre- sented as being more finely marked. Judging, however, from D’Orbigny’s figure 8, the base of the two shells is identical. On the whole, the Wydale shell may be deemed a dwarf variety of the Pl. Minsteri group, somewhat differing from any form as yet described. There is a form of about the same size, and with many points in common, which occurs in the shell-bed at Cumnor, near the top of the Lower Calcareous Grit. Thus similarity of physical conditions 1 It should be borne in mind that the Coralline Oolite of Scarborough Castle is lower geologically than the Coralline Oolite of Malton. 2 Sowerby’s species is a fossil of the Inferior Oolite, originally described (M. C. t. 220, fig. 2) from Dundry. He gives two figures, but does not distinguish them by letter or numeral. The specimens are not in the type collection at the New Natural History Museum. Nevertheless, since a fossil similar to the right-hand figure isso common in the Inferior Oolite of Bradford Abbas and elsewhere, we cannot be in doubt as to the form of Sowerby’s species. ‘That author says that ‘‘ the granulated surface is the result of decussating furrows which vary in depth and number in different individuals.” I have examined a large series of English speci- mens from the Inferior Oolite, and find that Sowerby’s P. granulata, though subject to great variety, has a much wider spiral angle, is more umbilicated, and has a greater variety of ornamentation. Nevertheless there are forms in the Inferior Oolite of Normandy classed by Deslongchampsas varieties of P. granulata (see Mem. Soc. Linn. Norm. vol. viii. pl. 16, fig. 6a), which lead up to the Cornbrash species, and also to the form now under consideration. See also a figure in Quenstedt’s Der Jura, pl. 57. fig. 7, of a fossil from the Brauner Jura delta, p. 414. Still the elements of the Plewrotomaria in the Yorkshire Cornbrash, which must be regarded as very closely related to the shell now figured, are clearly not those of P7. granulata, Sow., in any respect beyond the granulated character of the general sculpture. We have seen that Sowerby regarded the granulated surface of his species as the result of decussating furrows varying in depth and number ; hence, when we bear in mind like- wise the great differences in external appearance due to various conditions of mineral- ization, too much stress should not be laid upon mere granulation. W. H. Hudleston—The Yorkshire Oolite. 123 is accompanied by approximately identical modifications of form and growth, 51.—Pxievrotomaria Minsrert, Roemer, 1839, Not figured. Pleurotomaria Minsteri, Roemer, 1839, Suppl. to Ool. Geb. p. 44, pl. xx. fig. 12. Idem, Dee 1852, Terr. Jurass. vol. ii. p. 549, pl. 416, gs. 4-8. There occurs in the Upper Limestones at Filey Brigg, and else- where about the same horizon, a Plewrotomaria which, though not much larger than the one previously described, approaches still more closely to Roemer’s species in its outline, dimensions, and the step- like character of the whorls, which has only one keel. In more typical specimens of Pl. Minster, such as those from the Elsworth Rock, and especially from the Trigonia-beds of Osmington (Corallian Series of Weymouth), the transverse ribbing is more continuous and less granulated than in the Yorkshire specimens. This arises from the comparative shallowness of the decussating furrow, and is pro- bably too much the result of varying conditions of preservation to be regarded as a feature of primary importance. Though tolerably common, I have never been able to obtain a Specimen in good preservation, but there is a fossil in the Leckenby Collection marked “‘ Pleurotomaria granulata, Sow., Lower Calcareous Grit, Filey Brigg,” which I have very little doubt belongs to this variety, and probably comes from the Upper Limestones of that locality. 52.—PLEUROTOMARIA RETICULATA, Sowerby, 1821. Plate IV. Fig. 3. Trochus reticulatus, Sowerby, 1821, Min. Conch. table 272, fig. 2. Bibliography, ete.—Sowerby’s original specimens were from the Lower Kimmeridge of Ringstead Bay, observed also at Portland Ferry in the same formation. He gives as the diagnosis “ conical, transversely reticulate-striated ; whorls bicarinated, base convex.’’? Description—Specimen from the Coral Rag of Settrington (my Collection). ILEMRIN onesqdoo00c ar eMvaveh wlarcacyeuderal ae surartg 33 millimetres. \WAGHING Sao Se mea Oo On OROTBION Stas iatan oat 31 5 Spiralfani Ol emereeucreieecsrteYorieyetectens tase teers 273°. Shell trochiform, turrited, but slightly oblique, scarcely umbili- cated. Spire composed of six or seven whorls, which are strongly bicarinated, the upper keel being more acute than the other. It is situated at the angle of the whorl, and carries the band of the sinus. The imbrications are smoothed by attrition. The ornaments con- sist of a system of transverse lines, met at right angles by a system of longitudinal ones, thus producing a net-like or reticulate structure, which appears, however, to be subject to considerable irregularity, and sometimes approaches the granular ornamentation of the 1 Both the figure and description by Sowerby indicate that this species should be bicarinated. Yet in the type collection at the New Natural History Museum are three specimens not figured (the figured specimen should be at Cambridge), which clearly come from the Zrigonia-beds of Weymouth, and belong to its very close relative, P/. Miinsteri, the more usual Oxfordian form. 124 W. H. Hudleston—The Yorkshire Oolite. Wydale species. The specimen towards the last whorl is in- differently preserved. Relations and Distribution. — The differences between this form and the more typical Pl. Miinsteri are, that this one has a narrower spiral angle, and has the whorl distinctly bicarinated, and each whorl is less completely overlapped by the succeeding one, so that the sutural excavation is more marked. On the other hand, it resembles the types of that species in having the ornamentation reticulated rather than granulated, that is to say, the transverse ribbing is not cut through sufficiently deeply to produce a very distinct granulation, though there is an approach to it in some places. With respect to distribution this must be viewed as representing Pl. Miinsteri in the higher beds. It is clearly a Kimmeridge form, though I cannot find it noticed on the Continent from beds of that age. Rare in the Coral Rag of the Howardian Hills. 08.—P LEevRoToMARIA AGassrzit, Miinster, 1844. Plate IV. Figs. 4a, 0. Pleurotomaria Agassizii, Miinster, Goldfuss, 1844, pt. 3, p. 71, pl. 186, fig. 9. Idem Idem, D’ Orbigny, 1852, Terr. Jurass. vol. i. p. 572, pl. 426, figs. 1-5. Bibliography, etc.—Munster’s species was from the Corallenkalke of Nattheim. His description is not very close, but the figure (enlarged) is fairly like the specimen now under consideration. That this is the species intended by D’Orbigny there is every reason to believe, as his description in most respects tallies with the North Grimston specimen, though his figure, which is almost too good for a fossil, is somewhat different. Description.—Specimen from the Coral Rag of North Grimston (Strickland Collection). Gn OU Beier creies seers sos sR ee Acer eas 72 millimetres. AVVAIC Uti 2 ccmecemetaimenh fh hela. Mn ae arm ai 60 »» Spiraltamp lee rnin cis Al eat eiUeitvad ied es 60°. Shell conical, trochiform, umbilicated. Spire composed of about nine whorls (seven now remain without the apex). These, with the exception of the last whorl, increase under a regular angle, and are so close, towards the apex, that the suture can with difficulty be made out. They are nearly flat, and down to the margin of the penultimate form an almost unbroken cone. The penultimate is rather swollen, and the last whorl is obtusely angular. The ornaments vary in different parts of the shell. In the posterior whorls the closely-set transverse ribbing is fine and rather granular. Anteriorly the system of transverse coste is wider apart, sometimes granulated, sometimes almost continuous, but on the whole irregular and coarsish over the entire surface of the two last whorls. A characteristic feature is a double row of thick rough tuberculations, which become very prominent in the anterior whorls. Between these the imbricated band of the sinus is conspicuous, occupying a postion a little above the middle of each whorl. The base is nearly flat, and has the irregular ornamentation of the rest of the body- whorl without the tuberculations. The sides of the umbilicus are steep, and the columella but slightly inclined outwards. W. H. Hudleston—The Yorkshire Oolite. 125 The aperture is irregularly quadrate: angular externally, and but little cut away on the interior. Relations and Distribution.—This is by far the finest specimen of the ornamented group of Pleurotomaria, allied to Pl. anglica, which has ever been found in beds of this age in Yorkshire. There is a specimen in the Leckenby Collection—length 82mm., width 28mm. —which may be regarded as representing the usual size of this some- what rare form. Thus Sir Charles Strickland’s shell may almost be viewed as a megalomorph, bigger even than the foreign specimens described by Goldfuss and D’Orbigny. Itis only right to point out that D’Orbigny describes Pl. Agassizii as having the aperture shortened anteriorly, which can hardly be said to be the case with this shell, whose aperture is more like that of Pl. Hesione, D’Orb., or of Pl. Phedra, D’Orb., which are supposed to represent this group on a higher horizon. D’Orbigny’s Pl. Agassizii has been obtained in the Yonne, Haute Sione, and Charente Inferieure. In the Corallian of Weymouth there is a shell which has more affinity with Pl. Pelea (see Damon’s Suppl. 1880, pl. xvii. fig 8), having only a single instead of a double row of tuberculations, and being in other respects different to the North Grimston shell. Whiteaves (Ann. and Mag. Nat. Hist. 1861, vol. vill. p. 142 et. seq.) quotesa new species of Pleurotomaria allied to anglica from the Corallian of Oxford, and somewhat similar forms have been found sparingly in the Coral Rag of other districts. Genus Paretua, Linneus, 1758= Helcion, Montfort and D’Orbigny. Shells of this genus are particularly scarce from the Corallian rocks of Yorkshire. There are one or two bad specimens in some collections, but the only decently-preserved specimen known to me is the one described below. 54.—PatTeLta ruGosA, Sowerby, 1816. Variety. Plate IV. Fig 5. Patella rugosa, Sowerby, 1816, Min. Conch. t. 139, fig. 6. Idem. Idem. 1850, Morris and Lycett, Gt. Ool. Moll. p. 89, pl. xii. figs. 1, la-g. Patella Mosensis, Buvignier, 1852, Stat. géol. de la Meuse, p. 27, pl. 21, figs. 3-4. Bibliography, etc.—The type form of Sowerby’s species is the well- known and abundant Patella from Minchinhampton, of which such forms as P. Tessoni, Deslong., may probably be regarded as megalo- morphs. With modifications, P. rugosa would seem to have an extensive vertical range. Helcion Lupellensis, D’Orb. (Prod. de Pal. Strat. vol. ii. p. 12), from the Corallian of La Rochelle, is probably a representative. P. Mosensis, Buv., is also a near relative, representing the species on the same horizon in the region of the Meuse. That author describes his species as being near to P. rugosa, Sow., from which it is to be distinguished by a sharper apex, finer lines of increase, and less elevation. Buvignier’s figure, however, will hardly fit the Yorkshire specimen. Description.—Specimen from the Coral Rag of North Grimston (Strickland Collection). IUGMERIM, gogceodau0c0729005b0Cb00ou0DbNsC 25 millimétres. WIG oo oenoenradddnoscooooddooadNnO ce KS 21:5 55 126 W. H. Hudleston—The Yorkshire Oolite. Shell oval, depressed; apex (imperfectly preserved) near the anterior margin. Ornamented with longitudinal radiating ribs, which are fine and wavy, and partly deflected where they are decussated by a few encircling rugose bands. ‘The condition of the specimen scarcely admits of closer description. Relations and Distribution.— From the bulk of the Minchinhampton specimens this variety is clearly distinguished by the fine and more wavy character of the longitudinal radiating ribs. Still these are not so fine as those shown in Buvignier’s figure of P. Mosensis. No instance of any variety of Patella rugosa having been found on this horizon in other parts of England is known to me, so that this specimen from the hard Rag of North Grimston is almost unique. An imperfect specimen from the Upper Calcareous Grit of Pickering may belong here. Order OpistHoprancaratTa, M. Edwards. This section of the Gasteropoda is so poorly represented, and the specimens are for the most part in such bad preservation, that very little can be said on the subject, which must be disposed of briefly. Genus Butua, Klein, 1753. Shell oval, ventricose, convoluted. Apex perforated. Aperture longer than the shell, rounded at each end, lip sharp. 55.—Butia (? Akera) Beauerannvt, De Loriol, 1874. Plate 1V. Fig. 6. Akera Beaugrandi, Loriol, 1874, Loriol and Pellat, Et. Sup. Jurass. de Boulogne, vol. i. p. 38, pl. vi. fig. 1. Description. — Specimen from the Coral Rag of Ayton (my Collection). Length, restored ....... 0000000000000 00000 . 40 millimetres. \ AGH AYERS CSIMINKS 555600 0000000 500000 o00c 24 5 Shell oval, moderately elongate, contracted at either extremity, and slightly tumid in the middle. Spire apparently composed of two or three whorls. The last is very large, and has its surface covered with broad and very marked lines of increase, which, from their prominence and irregularity, produce a certain amount of sculpture on the otherwise smooth surface. The inner lip is broken away anteriorly, and the outer lip so involved in matrix that a closer description is impracticable. Relations and Distribution.—There is so little to distinguish the various species of Bulla from one another that, when, as in this case, a specimen is unique and deeply involved in matrix, some difficulty arises as to its correct identification. Akera Beaugrandi occurs in the Pterocérian of the Boulonnais. In outline and proportions, and especially in the broad lines of growth, the Ayton specimen greatly resembles De Loriol’s species. Unfortunately, there is no evidence that the anterior portion of the columella is as much excavated as in the type specimen. Buvignier has two species of Bulla, viz. Bb. Dyonisea, Buv. (Stat. géol. de la Meuse, p. 28, pl. 21, figs. 25 and 26), and Bulla Moreana, Buv. (op. cit. p. 28, pl. 21, figs. 83 and 34)— both from the “argile de Kimmeridge” of the Meuse—which also W. H. Hudleston—The Yorkshire Oolite. UD bear some resemblance to the specimen under consideration. The proportions of B. Dyonisea especially come very near, but the lines of growth are represented as being fine in that species. Genus Actmon, Montfort, 1870 = Tornatella, Lamarck. Shell conically ovate, with a conical, many-whorled spire. Spirally grooved or punctate-striate ; columelia with a long tortuous fold. Actmonina, D’Orbigny, 1850, is an Acteon (Tornatella), without plaits on the columella. Cyxtinpritres, Lycett, 1850, is regarded by S. P. Woodward as a subgenus of Actgon (cf. Great Ool. Moll. p. 97, and Manual of Mollusca, p. 180). Section 1: Shell smooth, slender, subcylindrical; spire small, aperture long and narrow, columella rounded, twisted and directed slightly outwards. Section 2: Shell oval, spire sunk, whorls with acute margins. This subgenus is apparently not recognized by continental authors. 506.—ActTmon RETUSUS, Phillips, 1829. Plate IV. Fig. 7. Acteon retusus, D’Orbigny. Prod. de Pal. Strat. vol. i. p. 353, Et. Oxf. Bibliography, etc.— Phillips’s specimen most probably came from the Lower Calcareous Grit of the coast. The columella in his figure appears more twisted than is the case with the specimen under consideration. Description.—Specimen from the Coral Rag of Ayton (Leckenby Collection). ICN GG secscanesiacsnwsievcveveuesecceede cases aceews Che’ 19 millimétres. AAV cogsapacencoundenbacoscoscsdodoo0scn5cHUdacbOoeD co W 2: Ratio of body-whorl to entire length............... d3§ WOW. Shell ovately-cylindrical, smooth. Spire composed of four or five whorls, which are tumid, increase suddenly, and are clearly separated by the suture. The height of the body-whorl is three-fourths of the entire shell. In form it is an ovate cylinder rapidly contracting at either extremity. The aperture extends over almost the entire length of the body-whorl, and is narrow posteriorly. The outer lip appears to be rather thick. The inner lip, nearly straight at first, is strongly excavated anteriorly, but scarcely twisted (? Actconina). It projects clear of the columella, which is solid. Anterior portion of the aperture wide. No markings other than fine lines of growth can be distinguished. Relations and Distribution.—This form is near to Bulla (Acta@onina) oliveformis, Koch and Dunker (Nordd. Oolith. p. 41, pl. v. fig. 3), which is said to occur in the Upper “ Corallenkalke”’ of the Middle Oolite along with Astarte rotundata, Roemer, Melania striata, Sow., and Cidarites Blumenbachiit, Goldf.—the very species which are companions of the Ayton shell. Phillips’s species is more usually met with in the Lower Calcareous Grit, but it is not common any - where. 57.—CyLInDRITES ELONGATUS, Phillips, 1829. Plate IV. Fig. 8. Bulla elongata, Phillips, 1829, Geology of Yorkshire, vol. i. pl. iv. fig. 7. Cylindrites elongata, Phillips, 1875, op. cit. 3rd ed. p. 260. 128 W. H. Hudleston—The Yorkshire Oolite. Bibliography, etc. —No description has ever been given of this species, and Phillips’s figure is turned in such a way as to show nothing of the twist in the columella, which would seem to exclude it from the Bullide. Those foreign authors who have been bold enough to speculate in this connexion have generally regarded this species as a Bulla. Thus Brauns (Ob. Jura, p. 259), in describing Bulla Hildesiensis, Roemer, refers to Bulla elongata. De Loriol also (Et. Supr. Jurass. de Boulogne, vol. 1. p. 88) appears to conceive that Bulla elongata is a true Bulla, having certain “rapports” with Akera Beaugrandi. As all the specimens accessible to me are in a wretched state of preservation, I can only suggest that the species in question may belong to the second section of Cylindrites, which in the sunken character of the spire and thinness of the outer lp approaches Bulla. Description. — Imperfect specimen, Passage-beds of the Lower Limestones, Scarborough Castle (my Collection). IWGNSUIN 395455040 60000000900 5000 008 DOad0DDO 38 millimétres. Stee Anil ght A NG CONE AIRS 3 LO: lee Shell ovate-elongate, contracted at either extremity, but more so anteriorly. Spire composed of few whorls, smooth, and showing no lines of increase. Shell substance rather thick, except on the outer lip. Aperture long and narrow throughout, but more especially towards the posterior extremity. ‘The excavation of the columella is gradual ; near the base it is strongly twisted and directed outwards so as to meet the outer lip with a sharp curve. (N.B.—The anterior extremity of the aperture is broken away in Fig. 8.) Relations and Distribution. — Cylindrites elongatus is excessively plentiful in the Passage-beds and body of the Lower Limestones of the Tabular Hills, where, along with Gervillia aviculoides, it con- tributes largely to the shell-beds of that horizon. It is almost un- known in the Coralline Oolite, and has never, to my knowledge, been found in the Coral Rag. Thus it must be regarded as an Upper Oxfordian fossil, whose representatives should be sought in such beds as the “ Oolithe ferrugineuse”’ rather than in the “ Coral Rag” of the Continent. 58.—Cyxinprites, sp. Plate IV. Fig. 9. The specimen figured is from the Coral Rag of Ayton. It represents a form which is of somewhat rare occurrence in the Coral Rag of the Scarborough district. The examples hitherto found are too imperfect to identify or describe. The nearest species is pro- bably Cylindrites Lhuidii, Whiteaves. It belongs to the section of Cylindrites with a well-developed spire, whereas Cy. elongatus belongs, as we have seen, to the section where the spire is sunken. EXPLANATION OF PLATE IY. Fic. la. Trochotoma tornatilis, Phillips. Coral Rag of Brompton. Strickland Collection. ‘ wo le As Same Collection. OC. R. North Grimston. aan b Pleurotomaria, species. Lower Limestones, Wydale. My Collection. Front and back. W. H. Hudleston—The Yorkshire Oolite. 129 Fie. 2¢. Portion of same magnified. », 38. Pleurotomaria reticulata, Sowerby. Coral Rag of Settrington Grange. My Collection. » 4aandd. ,, -Agassizii, Miinster. Coral Rag of N. Grimston. Strick- land Collection. Back and front. » 5. Patella rugosa, Sowerby, variety. Coral Rag of N. Grimston. Strickland Collection. . Bulla Beaugrandi. De Loriol. Coral Rag of Ayton. My Collection. . Acteon retusus, Phillips. Coral Rag of Ay ton. Leckenby Collection. . Cylindrites elongatus, Phillips. Passage- beds of the Lower Limestones, Scarborough Castle. My Collection. » 9. Cylindrites, sp. Coral Rag of Ayton. “My Collection. EXPLANATION OF TABLE. The table annexed contains a complete list of the Gasteropoda entitled to be regarded as species belonging to the Corallian beds in Yorkshire. On referring to the generalized scheme of these beds in the special introduction, pp. 246—247, the various subdivisions are indicated, but a few additional remarks explanatory of the four columns in the table of fossils may be useful. The basal beds of the Kimmeridge Clay limit the group upwards. The Supracoralline beds, which immediately underlie these, have hitherto yielded such very poor traces of Univalves, that it is not worth while to devote a column to this subformation. C.R. No. 2.— This is the Florigemma-Rag, which girdles the western half of the Vale of Pickering, and overlies the Coralline Oolite of those regions. North Grimston, Langton Wold, Hildenley, Slingsby, etc., have been the most productive localities. Its fauna is fairly similar to that of C.R. No. 1; but where the forms are identical or analogous, they are for the most part finer and larger. Its affinities with the fauna of the Coral Rag at Upware are rather striking—shown perhaps still more in the Conchifera. C.R. No. 1.—This is the Coral Rag which occupies the inner slopes flanking the Vale of Pickering eastwards from Brompton. Seamer station is the nearest point to Scarborough, distant about three miles. Brompton, Ruston, Ayton and Seamer are the best places for collecting; and as all these villages are within an easy drive of Scarborough, that town is often quoted as the locality for the fossils of this Rag. It is devoid of Cidaris florigemma, but contains Cid. Smithii C.0.—The Coralline Oolite includes the Chemnitzia-limestones, and calcareous pastes with Oolite which underlie the Coral Rags throughout the circuit of the Vale. The Oolite at Malton belongs here. Paleeontologically it includes the shell-beds connected with the Middle Calcareous Grit, especially the Trigonia-beds at Pickering. The subdivision contains a large and varied assemblage of Conchi- fera, but the Gasteropoda, though individually abundant in some instances, belong to few species. L.L.—The Lower Limestones constitute an important group or subformation in a stratigraphical sense, and they contain large beds 1 There may be some doubt as to whether all the spines of Cidaris—tfor the test is hardly ever met with—really belong to C. Smithii, Wright, but no ene which could fairly be referred to C. florigemma has been found. DECADE II.—VOL. VIII.—NO. III. 9 ~ ~ [ool mer) 130 W. H. Hudleston—The Yorkshire Oolite. of Oolite, which have been frequently mistaken for the Oolites above the Middle Calcareous Grit. The so-called Coralline Oolite of Scarborough Castle belongs here. Gasteropoda are scarce and badly preserved with few exceptions. The Lower Coral Rag of Hackness is in this series, and the shell-beds on this horizon in other localities (e.g. Wydale) have yielded a few specimens. LCG, Lower Calcareous Grit. N.B.—The numbers on the left side of the Table refer to species described in the Memoir. vr means very rare; r rare; * moder- ately plentiful ; c, common; v c, very common. CORALLIAN GASTEROPODA, YORKSHIRE: GENERA AND SPECIES. Hrlby 'C484) uColB> ff Col 1 2 I | Purpuroidea nodulata, Young and Bird ... ... aoe Ld val * 2 — cf. tuberosa, Sowerby a00'|| 660 |) coe |} os oO, species : SG ode, EDU SoHE |) Made eil lh 0605 Ih doo vr Murex Haccanensis, Phillips we daa t6a0 ? 3 | Watica buccinozdea, Young and Bird Wiigles “oe Mkiters b06 20 rt 4 Clymenia, D’Orbigny ... ... «| 500 * * 5 Cipyide, SOOM S53, 385 S43 bon I S50 300 a vr 6 arguta, Phillips... ... dos’ aco! fase || o00 r r 7 | Chemnitzia Heddingtonensis, Sowerby 100 990 ez vel ec c 8 Pollux, D’Orbigny ... 696) [IP cea, lilt “Soe vr 9 Langtonensis, Blake and Hudleston aoe ae 660 vr 10 86 GMT, WY CTOEINF ag Ga. a] 000 a0 || coo vr Os (Cia, \DKOVMEAIG; ana ad 380 | dhe |] Gor r It | ‘‘ Phasianella” striata, Sowerby ... ... « oo Ci) We r 12 | Ph. striata, var. Bartonensts ... 1... vee one ee SAD bs r 13 | Pseudomelania gracilis, Sp.M. ... 12. v0. nee | vee 000 ip 14 | —. Buvigniert, auctorum Snbn or aso | ¢ aan |) eae r Yr I5 | ———— species... .. See Utces~ Rcicieig’ cored ti eloe aha iiececa lie weal H@ | —= Leymeriti, D’Archiac fee tiulersee) Cs seal A VRE Tee tere 17 | Certthium muricatum, Sowerby ... ... «| oe c 18 — Russiense, D Orbigny abo, cao 1G Gel te 19 — near to imeforme, Roemer, pes cone ieee r c * 20 | ————— near to grandimeum, Buvignier ...| ... |... r 21 | ———— near to Humbertinum, Buvignier ...| ... | ... ie 22 | ———— dicinctum, Sp.D.... 0. cee cee ee | nee 004 ee vr BE, | ——$ = GUO, BHDsiV6 090 00m 900 400-00 || ie 24. | ————- imornatum, Buvignier cfc Aegis gee core | aaa r c r 25 | Nerinea fusiformis, D’Orbigny ge ies Ae ll ice 2 ? 26 | ————. Moreana, D’Orbigny SPRMLACGH inci li mcceee Uy weet Gras vr ditto, Brompton ae sek VT Goo a TAMSIN Ee Seoe Ail lave * 27 | —— species tok Beene) cee cons moo karescueh| leboce |e Airis 28 | ———— _pseudovisurgis, sp. IS.) sce Pasar nace Nisashlh hacen AIRY 29 | ———— emeri, Phillippi... ... ... «. Pp lavac c 30 | ———— species... . Gale sepa adee leyseere lh ddr (aos: r 31 Goodhallii, Sowerby .. OS eee ast het One| eae vr BP) || altace lye aaser, OWNS jan Gen San cen aoe |LOG 33 | Littorina muricata, Sow. var. A. ... «.. «..|LCG} ? —__. SOW svat aD eosin asics vals * c * ———_ ——— Sow. var. G% ... neue | one ae at * PUTA Gi Sear Hage WD Oferta? | ey 9a | coo |). aco r Alaria, "ch. tridactyla, Buvignier can ade" |} 00 d00 AB r 34 | Amberleya Stricklandi, sp.n. ... .12 vee nee | ae 000 r ? 35 | ————_ grinceps, Roemer AIO day | aoe gaa HES oad 500 oe vr W. A. E. Ussher— Prehistoric Europe.” 131 36 | Neritopsis Guerre’, Hébert and ena ata Aare toae r 37 Moreauana, DiOxbienysass ees eek alreat ? 38 decussata, Miinster Aa: eietes es Bae Bp vr 39 | Turbo corallensis, Buvignier Micah raletet lotdlaasl Paamet [ive Aten se r 40 LETS, ID ONAN 255. Gon a3 eo ||. S80 sat 200 r 41 —— levis, Buvignier ... G03 e668. 1000’ S90" Bor 308 r r 42 | Delphinula funiculata, Phillips Stes Losey lassie | jeans r * r 43 JQ Nas, IDS MOTO! \ Ges loud. 000) 050 |e coe Ree eee Vat 44. | Trochus obsoletuns, Raemlerstie; cas 5) cee eee sce. Var 45 | ———— aeuticarina, Buvignier ... 2. vee | nce | vee | wee vr 46 | —— granularis, sp.n. 000 | G00 |) 008 ? 47 | —-—— Aytonensis, Blake and Hudleston ... |... r r 48 | ———— species.. Bae MeBoe Ooi 908 sf Ttobd 560 || WIE 49 | Trochotoma tornatilis, ‘Phillips PREACH ec ene cel INE 500 c * 50 | Pleurotomaria, sp... s00 060, 009 cos |) WE Sl | ———— Minsteri, Roemer a iis ames vas * 52 | —— GetecUulata SOWEGDY) eee) ese) cease |e ee 83 abs r 53 Asassizee. Niumster se.) |) ae) es) eo 60 fae be vr 54 | Patella rugosa, Sowerby—variety ... ... ... |. oc aN vr 55 | Butla Beaugrandi, De Loriol ... ... «2. «.- ae Aoa ||) WV 8 5) | Adiaun raise, niles “ees Gan) cg ee cos, EIS Crl nce r 57 | Cylindrites elongatus, boeee Ned coca Wir reanim eee Ll |PaWy C R 58 | Cylindrites, species Tha ees ie ry ERRATA. Page 295, line 12, for 1850 read 1852, and similarly where vol. ii. %p Terrains J urassiques is quoted. », 298, dele,, ,, ,, 4, Under the word buccinordea. », 9394, line 20, for fig. 2 read fig. 3 y OOEy ph ORY Te, Tie, », 403, last line but one, for 3 read 2. ree asuslinebUbibWOsaE ec iseatOs », 404, line 12, for Rag read Oolite. », 484, ,, 8, ,, St. Michel read St. Mihiel. », Idem,, 21, ,, Verdunense ,, Virdunense. », 485, ,, 42, ,, species read individual. 5, 488, ,, 1, ,, St. Michel read St. Mihiel. », 085, ,, 386, ,, Heve read Heéve. V.—‘ Preuistoric Evrope”—Svupmercep Forests anp Forest- Brps, CornwaLt. By W. A. KE. Ussuer, F.G.S. N Mr. Geikie’s admirable work on “Prehistoric Europe,” in the chapter ‘‘On British Post-Glacial and Recent Deposits,” he alludes more than once in very flattering terms to my share in elucidating Cornish Post-Tertiary Geology, at the same time, how- ever, questioning certain conclusions attributed to me with reference to the general correlation of the Forest-beds in stream-sections, 7.e. those resting on the tin ground, with the Forests ‘‘ exposed upon the present foreshore.” Mr. Geikie says, after sifting the evidence, p. 441: “I have been unable to discover the grounds upon which it is assumed that the Lower Peat and Trees which rest upon the tin gravels are necessarily synchronous with the submerged forests exposed upon the present foreshore. In some cases this may be the fact, but it is hard to believe, on the evidence produced, that this correlation can be gene- 132 W. A. E. Ussher—< Prehistoric Europe?’ — rally sustained.” After illustrating his objection by a reference to the Happy Union Section described by Mr. Colenso at Pentuan, he arrives at the conclusion that the ancient forest-bed on the stream- tin-gravels is a relic of an older land surface than that represented by the submarine forests on the present coast-line. Had I stated that the forest-beds in question were generally cor- relative with the traces of vegetation from time to time discoverable on the present foreshore, I should have committed the egregious error into which Prof. Geikie thinks I have fallen, and that upon the single favourable datum furnished by Mr. Carne’s section of Huel Darlington mine in the vicinity of Mounts Bay. In Post-Tertiary Geology of Cornwall (printed for private circulation in 1879), p. 45, I have stated my views as follows: ‘‘ The growth of the old forest, the relics of which have been met with all round the Cornish coast, must have extended over a long period of time. The evident connexion of the Mounts Bay Forest with the bed in Marazion Marsh overlying stream-tin, pointed out by Mr. Carne ; and the constant presence of a distinct vegetable stratum, or of detritus mixed with vegetable matter, on the tin-gravels in most of the principal sections, points to a general correlation of the sub- merged forests on the coasts with the forest-bed in stream-tin sections.” I did not anticipate the acceptation of the phrase “submerged forests on the coasts,” in the above passage, in so littorally literal a sense as “‘the submerged forests exposed upon the present foreshore,” as Prof. Geikie has rendered it, but meant by it the extensive tract of which these traces between high- and low- water mark are the only observable relics—a tract of the extension of which I have taken (op. cit. p. 43) the depths of the stream-tin gravels of Par, Pentuan, Carnon, etc., below the sea-level to be indicative. I conceive the forests to have flourished over a wide area extend- ing beyond the limits of the present coasts. That this area was of the nature of a great plain broken and stepped by old marine terraces modified by subaerial denudation, and that it was breached by valleys representing the then existing lines of drainage and also clothed with vegetation. As a gradual subsidence narrowed the limits of the forest tract, the sea in its advance would naturally encroach upon the valleys, and if the forest growth continued un- impaired on the plain, and in its inequalities, the lower tracts would of course be first submerged, and their submersion could not be regarded as strictly synchronous with that of the forest belt fringing parts of the foreshore where no such depression existed. But here again I must guard myself against misunderstanding. I do not think that those parts of the forest which had taken root in the tin ground in the valleys were left in undisputed possession of those positions from their first growth until the access of the sea to their sites (Vide Pleistocene Geology of Cornwall, Part IV. General Notes on Submerged Forests and Tin Gravels, Gron. Mac. for 1879. “‘T'o synchronize the forest remains in the various sections, etc.,” and “In like manner the duration of the forest growth, etc.’) and Forest-beds in Cornwall. 133 Such an idea would postulate the entire desertion of the main drainage lines during the period of forest growth, of the duration of which the Forest-bed in stream-tin sections affords no measure whatsoever. Take for example the Happy Union Valley. Part of it was at least tenanted by running water, the old forest-bed (to use a relative term) being buried beneath a stratum of silt, probably river detritus, one foot thick; then we have a nearly continuous layer of vegetable matter, probably drifted, and an appearance of silting up and of moss growth, the water being confined to small runlets hardly breaking the continuity of vegetable matter. After this the gradual prevalence of estuarine ccrditions is evidenced in a bed of silt, which resembles, from the description, as Mr. Geikie points out, the bluish clay so often found beneath the submerged forests on the foreshore. In this silt drift-wood also occurs; but as the top of the bed is about 18 feet below low-water level, it would have been, supposing the growth in situ, subjected to estuarine conditions before the forest belt on the foreshore was buried beneath sea sand; and the vegetable matter corresponding strictly in position with the submerged forest between high- and low-water mark would, as Mr. Geikie points out, occur in the bed of sand 20 feet thick, in which oaks were found lying in all directions, and bones of red-deer, etc. In Carnon Stream Works, as given by Mr. Henwood (T.R.G.S. Corn. vol. iv.), where human remains were found in association with vegetable matter at 46 feet below low-water, there would appear to be no vegetable representative of the forest growth on the foreshore: but I cannot therefore regard the vegetable bed on the tin ground in this section as representing an older land surface than the submerged forests fringing the coast-line, in any other sense than its position in a depression entitles us to infer—that its growth as a tiny portion of a large forest tract was of less duration than that of portions not similarly situated, and being submerged before the districts at a higher level did not remain a land-surface so long. The growth of woods on the tin ground soil would be unlikely to lead to the formation of a bluish-grey substratum, such as we find beneath most traces of submerged vegetation on the coasts, resulting from surface decomposition of the Killas, tinged by carbonaceous matter; so that such differences are no doubt due to the accidents of position. Local conditions, however, were so varied as to permit of the formation of a clay soil in certain valleys, Pentuan for example, upon alluvial deposits accumulated subsequently to the destruction of the parts of the forest rooted in the tin ground, and this clay appears to be similar to that which we find beneath those portions of the submerged forest between high- and low-water mark, which doubtless nourished the forestial growth from its beginning to its close over much of the area it originally occupied. The expression ‘‘older land-surface,” as indicated by the forest- bed on tin gravels, has been fully explained to me by Mr. Geikie, who kindly furnished me with the following summary of his views, thereby depriving these remarks of any controversial character. 134 G. H. Kinahan—Laccolites. 1. Forest-bed on stream-tin gravels=great forest growth: land of wider extent than now. 2. Marine and estuarine beds in stream-tin sections=submergence of land and entombment of trees. 3. Trees and forest-bed in upper part of stream-tin sections, and, probably, sub- merged forests on foreshore =elevation of land, and re-advance of trees. 4. Beds above 3 =partial submergence. In the above synopsis Mr. Geikie advocates a recent oscillation by which the dwindling forest growth gained new strength in a comparatively brief respite prior to its final decay; and is inclined to regard the traces of vegetation on the foreshore as relics of the re-growth of the trees upon sites rendered untenable by the previous subsiding movement. To this I have no objection whatever to urge: on the contrary, it is in conformity with the oscillation advocated by Mr. Godwin- Austen, to account for planed rock reefs at a little above high-water level’ (Rep. Brit. Assoc. for 1850, Trans. of Sects. p. 71). “Such an oscillation might serve to explain the river sediments gaining on the marine in estuarine stream-tin sections, and to enable them to continue, part passu, with a resumption of the subsiding move- ment,” etc., etc. (Pleistocene Geology of Cornwall, Part V. General Notes, Grou. Mag. for July, 1879). Mr. Geikie’s conclusions are based on an extensive knowledge of facts, collated from all quarters, and which, I need hardly say, were beyond my range. I could only advocate the probability of an oscillation of a few feet, as suggested by Mr. Godwin-Austen, so that from so restricted a point of view I could not regard the re-elevated foreshore as favourable to the growth of trees. I do not, however, think, as regards Cornwall, Devon, and Somerset, that the elevation hinted at might not, without militating against facts, . be made sufficiently elastic to have converted the shallows of such coasts as Mounts Bay into dry land, and have continued long enough, not only to arrest the decay of the surviving forests in inland localities, but even to permit of their re-growth upon deserted foreshore sites, and to give colour to the tradition of ‘“‘Caraclowse in Cowse, in English the hoare rock in the wood,” as applicable to St. Michael’s Mount. In conclusion, I must plead necessity for recurring at such length to this subject, at the same time expressing my thanks to Mr. Geikie for affording me the opportunity of explaining, more fully, views which the general tenor of my classification, as expressed in my papers on Cornish Post-Tertiary Geology, may have left somewhat ill defined, as it was foreign to my purpose to discuss at length the changes indicated by the details of individual stream-tin sections. VI.—Laccouirss. By G. H. Kinanan, M.R.1.A., President of the Royal Geological Society of Ireland. N the Report on the Geology of the Henry Mountains, Rocky 4 Mountain Region, Mr. G. K. Gilbert, of the U.S. Geographical and Geological Survey, points out that many of the intrusions of G. H. Kinahan—Laccolites. 135 eruptive rocks now exposed had a deep-seated origin; the molten rock having filled vacancies in the rocks, and never coming to the surface until they were exposed by denudation or by faults. To quote our author, “The lava... instead of rising through all the beds of the earth’s crust, stopped ata lower horizon, insinuated itself between two strata, and opened for itself a chamber by lifting all the superior beds. In this it congealed, forming a massive body of trap.” For these masses of eruptive rocks, Gilbert proposes the name laccolite (Gr. lakkos cistern, and lithos stone). In the Cos. Wexford and Wicklow some of the protrusions of eruptive rocks are entitled to this name, the rocks having congealed in cisterns below the surface of the earth; there are, however, some marked differences between them and the laccolites of the Henry Mountains. The latter were intruded into nearly horizontal strata, the laccolites only consist of one kind of rock, while the adjoining rocks seem to have been very little altered. But the Wexford and Wicklow laccolites, on the other hand, were intruded into highly disturbed strata, they are made up of a variety of rocks, and always the aquo-igneous action due to their intrusion—‘“ baked” or altered, a greater or less thickness of rocks about them. Vertical section of a Laccolite in contorted strata. > Baked rocks. Molten rocks of Laccolite. Fragmentary rocks The distance to which the “baking” has extended is very variable, on account of the ends, not the planes, of the differently composed beds being in contact with the eruptive rocks; rocks of different characters and composition being differently susceptible ; conse- quently, in regard to their composition, some have been more altered in depth and quality,—few apparently being ever changed into gneissoid and granitoid rocks. 136 G. H. Kinahan—Laccolites. The rocks in the more marked laccolites are usually gabbros or allied eurites, that graduate into granitoid, and allied basic elvans ; but sometimes there are also felstones with their allied elvans. Associated with these normal intrusive rocks are others of fragmentary character, like agglomerates and other tuffs. Such mechanically formed rocks are usually supposed to be accompaniments of surface accumula- tions; a little consideration, however, will show that it is not only possible but even highly probable that they accompany the formation of some laccolites. In order that a laccolite may be formed in a particular place, some favourable conditions must exist at that place. During the dis- turbances of the strata, such has taken place in the Cambro-Silurian rocks of Wicklow and Wexford, the horizontal jamming of one or more breadths of rock against each other would make them tend to rise and yield more readily to the pressure of the molten mass injected beneath. In some cases they might rise even independently of this pressure, leaving a vacancy under them, inviting the ingress of the lava ; such hollows might sometimes be enlarged by the gases being forced into them under high pressure, the gases blowing in, out of the passages, loose fragments of the rocks in addition to those carried in on the molten matter; and all brought into the chamber, either by the force of the gas or by the molten matter, be driven into the cracks or other vacancies, or be lifted up on the surface of the latter. The general character of the laccolites under consideration seems to be this—their principal mass or nucleus is composed of intrusive rocks, while on these and filling interstices in the “baked rocks ” are these fragmentary rocks, while ‘baked rocks” envelope all. Sometimes, however, these fragmentary rocks extend away into the “baked rocks.” An explanation for these also may be suggested ; open fissures existed between beds of strata or across them, all of which had to be filled; into those that terminated either upward or lengthways the fragmentary matter was blown and forced to remain in them, while if the fissure led to another cistern or to the surface, the fragmentary matter would be forced through or carried out of it; thus we should have dykes of the normal rocks of the laccolite leading from one to another, while on these normal rocks and in dykes or in apparently interbedded masses leading away from them, we should find their fragmentary adjuncts.’ The fragmentary rocks associated with the gabbros are often highly calcareous. In many cases they are an agglomerate con- taining limestone concretions ; and in some places there are masses of such agglomerates that appear to be independent laccolites, the rocks surrounding them being baked; in some places it is evident that small masses of such fragmentary rocks must have been pro- truded into their present positions. 1 Gilbert mentions as adjuncts to his laccolites ‘‘dykes and sheets’; these, how- ever, are filled with a rock the same as the laccolites, while in Wexford and Wicklow the dykes and sheets often seem to be fragmentary rocks. 137 aS¢) dal VA 2G 0H WV Se ——_e—_ T.—A MownocrarH OF THE SrLuRIAN Fosstts oF THE GIRVAN District in Ayrsurre. By H. A. Nicuoxson, and R. KvHeripGs, jun. Fasc. III. 8vo. pp. i—vi., 237—3841, and Plates xvi— xxiy. (London and Hdinburgh, Blackwood, & Co., 1880.) ESIDES descriptions of Serpulites and various so-called Worm- tracks (which are here carefully treated as having been pro- bably due to Crustaceans and other creeping and burrowing animals besides Worms), the Asteroid and Crinoid Echinodermata, found in the Silurian rocks of Girvan, are published in this Part of Nicholson and Etheridge’s excellent Monograph. It contains also some of the intended Supplements descriptive of (1.) Clathrodictyon and Hyalo- nema (?), but why the latter should be regarded as a Rhizopod is not clear; (2.) Heliolites, Plasmapora, Propora, Pinacopora, Haly- sites, and Favosites, among the Tabulate Corals ; (8.) Stawrocephalus, Cyclopyge, Trinucleus, Dionide, and Agnostus, among the Crustacea ; with (4.) the cirripedal Turrilepas. See also Grou. Mac. No. 177, p. 135 ; and No. 189, p. 189. These additions are chiefly based on a large amount of new material collected by Mrs. Gray and others in the Girvan district ; and are partly due to information accruing in the course of the work. The printing and paper are of the first quality, and the plates are also good. An index to the first volume, now completed, is given in this Fasciculus ; and great credit is due to the authors for these good results of their persistent and enthusiastic labour, supported by a Royal Society Government Grant. IL.—ReEvvusr pe GEOLOGIE, POUR LES ANNEES 1877 ET 1878. Par MM. Detzsss et De Lapparent. (Paris, F. Savy, 1880.) ROM the preface to the sixteenth volume, it would appear that this useful publication will now be brought to a close. During sixteen years, under the able editorship of M. Delesse associated with M. Langel in the first three numbers, and with M. de Lapparent in the continuation (vols. 4 to 16), this work has contained a concise account of the contents of the numerous papers connected with geology, and the allied sciences, during that period. The present volume records the progress of geology during the years 1877-78, and like the preceding ones, the subjects are arranged under five heads: Physiographic, Lithological, Historical, Geographic, and Dynamic Geology. Among the various papers collated, special attention has been given to the new researches on lithology, metamorphism and the analysis of rocks, as also to agricultural geology. The sixteen volumes will form a very important, if not an indispensable work of reference for the geologist, in which the authors have endeavoured to continue the useful work of M. d’Archiac, by giving, year by year, the principal facts bearing on the progress of the science. J. M. 138 Reports and Proceedings— eS Oink S AINE 2S OC aah ke,S. GEOLOGICAL Society or Lonpon. J.—Jan. 19, 1881.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. “Further Notes on the Family Diastoporide, Busk.” By G. R. Vine, Esq. Communicated by Prof. P. Martin Duncan, M.B. Lond., E.R.S., F.G.S. In continuing his review of the family of the Diastoporidea, the author stated that upon the question of the classification of the Polyzoa he is inclined to accept the views recently published by the Rev. T. Hincks, in preference to the earlier one enunciated by Prof. Busk. He now described the forms found in the Lias and Oolite, including Diastopora stromatoporides, Vine (= liassica, Quenst. \ D. sane aesm, Vine, D. oolitica, Vine, D. cricopora, Vine. The author then proceeded to argue against the inclusion of the foliaceous forms in the genus Diastopora, and concluded by giving a definition of the genus, as now limited by himself. _ 2. “Further Notes on the Carboniferous Fenestellide.” By G. W. Shrubsole, Esq., F.G.S. The author pointed out the discrepancies in the descriptions given by Lonsdale, Phillips, M‘Coy, and King of the genus Fenestella, as represented in the Silurian, Devonian, Carboniferous, and Permian formations respectively. He then proposed a new definition of his own, and described the following species:—/. plebeia, M‘Coy, F. membranacea, Phil., F. nodulosa, Phil., F. polyporata, Phil., F. crassa, M‘Coy, F. halkinensis, sp. nov.; and in conclusion he pointed out that the few species to which he has reduced the Carboniferous Fenestelle find their representatives in the North-American continent, only one really new form, J. Norwoodiana, having been described there. IJ.—February 2, 1881.—Robert Etheridge, Esq., F.R.S., Presi- dent, in the Chair.—The following communications were read :— 1. “On the Coralliferous Series of Sind, and its connexion with the last Upheaval of the Himalayas.” By Prof. P. Martin Duncan, M.B. Lond., F.R.S., F.G.S. This communication is the result of the author’s study and de- scription of the fossil corals of Sind, undertaken at the request of the Geological Survey of India. The history of the researches in the geology of the Tertiary deposits of Western Sind was noticed in relation to a statement made some years since by the author and Mr. H. M. Jenkins, F.G.S., that there was more than one Tertiary series there, in opposition to both D’Archiac and Haime. After a brief description of the geology of the Khirthar and Laki ranges of hills, which were called Hala Mountain by the French geologists, the succession of the stratigraphical series demonstrated by the survey under Blanford and Fedden was given, and the author proceeded to discuss the peculiarities of the six coral faunas of the Geological Society of London. 139 area, and to argue upon the conditions which prevailed during their existence. A transitional fauna, neither Cretaceous nor Hocene, underlies a trap: to the trap succeeds a great development of Num- mulitic beds, containing corals, the Ranikot series, some of which are gigantic representatives of European Nummulitic forms. A third fauna, the Khirthar, succeeds, and a fourth, Khirthar-Nari, which was a reef-building one; and a fifth, the Nari, is included in the Oligo- cene age. An important Miocene coralliferous series (the Gaj) is on the top of all. These faunas above the trap are Nummulitic, Oligo- cene and Miocene in age, and in the first two European forms, which are confined to definite horizons, are scattered indefinitely in a vertical range of many thousands of feet. The corals grew in shallow seas, but most of them were not massive limestone builders, but there were occasional fringing reefs, or rather banks of com- pound forms, which assisted in the development of limestones. Many genera of corals, which elsewhere are massive, are peduncu- late in Sind, and the number of species of the family Fungide is considerable. There are also alliances with the Eocene coral fauna of the West Indies. The depth of the coralliferous series and the intercalated unfossil- iferous sandstones, etc., is, according to the Survey, 14,000 feet, without counting an estimated 6000 feet of unfossiliferous strata in one particular group. The subsidence has therefore been vast, but not always continuous. After noticing the numbers of genera and species in this grand series of coral faunas and the remarkable distinctness of each, the author proceeded to discuss the second part of his subject. When President of the Society, he had stated in his Anniversary Address for 1878, that he was not convinced of the truth of the theory of the Geological Survey of India regarding the Pliocene age of the last Himalayan upheaval. The considerations arising from the position of a vast thickness of sedimentary deposits overlying the Gaj or marine Miocene, and containing Amphicyon, Mastodon, Dinotherium, and many Artiodactyles of the supposed pig-like ruminant group, lead to the belief that the author was not justified in opposing the theory enunciated by Lydekker and the Directors of the Survey. The position of these Manchhar strata on the flanks of the mountain system of Sind was compared with that of the sub-Himalayan deposits. The faunas were compared, and the Sewalik deposits, the equivalents of the Upper Manchhar series of Sind, were pro- nounced to be of Pliocene age. They were formed before and during the great upheaval of the Himalayas, and in some places are covered with glacial deposits. A comparison was instituted between these ossiferous strata and the beds of Eppelsheim and Pikermi, and the author discussed the question relating to the age of terrestrial accumulations overlying marine deposits. 2. “On two new Crinoids from the Upper Chalk of Southern Sweden.” By P. H. Carpenter, Esq., M.A. Communicated by Prof. P. Martin Duncan, M.B. Lond., F.R.S., F.G.S. 140 Reports and Proceedings—Gtol. Soc. London. Stem-joints of a Crinoid resembling those of Bourgueticrinus have long been known in the Plinerkalk of Streben (Elbe); but on the discovery of the calyx it was found to differ considerably from that genus. It was then referred to the genus Antedon by Prof. Geinitz. Stems also resembling Bourgueticrinus have been found in the Upper Chalk of Képinge (S. Sweden), and a calyx resembling that de- scribed by Prof. Geinitz has also been found. Prof. Lundgren kindly entrusted this to the author for description. For these two fossils he considers not only a new genus but also a new family required. He proposes for the former the name Meso- crinus, as the characters of its calyx ally it to the Pentacrinide. The author describes the characteristics of the genus Mesocrinus and of the species M. suecica (the Swedish) species, and _ its differences from M. Fischeri (from Streben), and discusses the relationships of the genus, which combines the characters of a Pentacrinus-calyx with a Bourgueticrinus-stem. A new species of Comatula (Antedon impressa) from the Ignaberga Limestone of Scania was also described, and its systematic position discussed. Dr. Otto Hahn, of Reutlingen, exhibited a large series of Micro- scopic sections of Meteorites, in explanation of which the following remarks were addressed to the President and Fellows present :— “Dr. Hahn, in inviting you to examine the microscopical speci- mens of meteorites which he has prepared, and in order to assist you in determining the character of the forms and structures which you will find exhibited in them, desires to present a short summary of the negative considerations which forbid that such structures should be classed among crystalline forrms. “Asis well known, the chondrites, the species of meteorites from which his specimens are prepared, consist, besides the metals which they enclose, of the minerals enstatite and olivine. “In his work on the meteorites and their organisms, lately pub- lished, Dr. Hahn has given photographs of 130 different forms and structures. Now if these structures are crystalline, the two minerals in question would present themselves in at least 130 different forms and structures, although the absence of all structure is recognized as a fundamental principle of the theory of minerals. ‘‘ Again, the structures exhibited by the chondrites cannot be due to slaty cleavage, since olivine has no slaty cleavage, and that of enstatite and of other minerals does not appear under the micro- scope, or else presents itself there under totally different forms. “The greatest importance, however, is to be attached to the total absence of all polarized light exhibited by the two minerals as occur- ring in the meteorites. The contained forms and structures do not polarize the light at all, or only very feebly, although the same minerals, under ordinary circumstances, polarize light very strongly. The absence of all aggregate polarization is especially noticeable, as proving that these objects are not aggregates of crystals. “Should we still feel inclined to regard the enclosures as mineral Correspondence—Prof. J. W. Darson. 141 forms, and not as organisms, we must be struck by the utter absence of all crystalline forms, especially in those very minerals which always, and occasionally also in meteorites, appear in a crystallized form. “Further, the external forms, and consequently the outlines of the enclosures, harmonize so perfectly with their internal form and structure, that we cannot entertain the idea that these enclosures had been rolled about and ground down before they became finally imbedded in the chondrites. “The idea of an aggregate of crystals, if still looked upon with favour, would be contradicted by the fact that the enclosed balls or globes are ail constructed excentrically, whereas all terrestrial crystallites are formed concentrically.” CORES O@iANe Dee GzEe STROMATOPORA AND CAUNOPORA. Srr,—In the August (1880) Number of the Grotocicat Macazrnz, which owing to some error of transmission has come to hand only a few days ago, I observe an interesting paper by Dr. F. Roemer, on the relation sometimes observed between the growth of Stromatopore and tubular corals ; and which in some formations in this country is so common as to have been regarded as a sort of “ commensalism.”’ I have referred to these cases in my paper on Stromatoporide in the Journal of the Geological Society for February, 1879, as well as to other perforations, probably due to the operations of some boring animal. While, however, some snecimens of these kinds may have been referred to the genus Cawnopora, it would be unfortunate if palzontologists should suppose tiat all the fossils of that genus are of the character in question. It will be seen by reference to the paper above cited, that such Caunopore as my C. Hudsonica, as well as C. incrustans and C. planulatum, Hall, not only have vertical canals which are essential parts of their structure, but that these canals send forth radiating tubes into the substance of the thickened lamine. Of the Stromatoporide with such vertical canals there are two types, which I have referred respectively to the genera Cawnopora of Phillips, and Cenostroma of Winchell: the former having single vertical tubes, the latter groups of such tubes. In America both genera begin in the Niagara formation and extend upward to the Chemung, or from the lower part of the Upper Silurian to the upper part of the Erian or Devonian. J. W. Dawson. McGitu’s Cottece, MontrEAt. ON CERTAIN CASES OF THE OUTCROP OF STRATA. S1r,—As the Rev. O. Fisher’s allusions to Spherical Trigonometry in your January Number may sadly perplex many accomplished geologists, who have not made a special study of higher mathe- matics, | venture to enclose a simplified explanation of his results. First, as regards the delineation of cylindrical surfaces exposed 142 Correspondence—The Rev. H. G. Day. in plane sections, the ordinary rule of ‘foreshortening,’ as taught in all Schools of Art, will amply suffice. I have found in practice that a shadow cast by sunlight on a paper properly inclined gives the true result most simply. It is, however, worthy of remark that the outcrop of a cylindrical stratum on a plane surface cannot differ from the outcrop of a plane stratum on a cylindrical hill, or in a hollow cylindrical valley ; and is therefore reducible to ‘‘Sopwith’s models.” Next, in assuming that the trail outcrop had a definite direction on either side of the railway cutting, does not Mr. Fisher assume that the trail lies in one plane ? Under these circumstances a straight rod placed at the one out- crop parallel to the other outcrop satisfactorily determines the strike and dip of the stratum. As regards the equation tan @ = cos § tan a (2) T subjoin a short proof. Let A B CD be horizontal (strike) lines in the inclined plane. B E vertical,-C D E a horizontal plane. Then 7 BCH=@ BDE=a CED=£8 Also CD Eis right angle. g BE _ BE cos Hence tan 6 OE ED =tan cosf H. G. Day, MA. THE PRE-CAMBRIAN ROCKS OF BRITAIN AND BOHEMIA. Srr,—In Dr. Callaway’s letter on this subject (Guon. Mac. Feb. 1881), there are some passages which are to my mind a little mis- leading in regard to the Dimetian rocks at St. Davids. The main portion of the group consists of what appears to be a massive granitoid rock, but on closer examination traces of foliation are Correspondence—Dr. Henry Hicks. 143 abundant. Indeed, throughout the whole group there is a schistose character developed, so that in consequence the most massive portions are found to be utterly worthless for dressing, either for building or paving purposes. This fact, though a species of rough evidence, is found to be very valuable in distinguishing many of the metamorphic rocks from those of igneous origin. In the latter the even admixture of the constituents and the regular crystallization enable them to be readily dressed in blocks, whilst the former, except where they consist of limestone or such-like sediments, are seldom sufficiently even in character through any thickness for this purpose. Hence the intrusive granites, greenstones, and various lava flows are frequently used for building and paving purposes, but the metamor- phic rocks but seldom. The term gneissic or schistose may certainly be applied to the St. Davids Dimetian rocks throughout, but perhaps more especially to the middle portion of the group, seen in the valley between the Camp and Ponthclaish. Here the beds are usually less massive than at the base, or in the upper or more quartzose portion, and on very slight weathering the foliated character is very marked. Thin lines of nearly pure white felspar are also common, and a tolerably clear gneissic appearance ex- hibited. It must not be expected that in these attempts at correlation anything like an absolute identity in character can be found in different areas. Certain general resemblances in mineral character, combined with the physical evidences indicative of contemporaneous deposition, are all we can expect, especially if, as I presume, I may take for granted, that most will now allow that these metamorphic rocks must have had at first an aqueous origin, and were deposited in successive layers of various materials like the alternating sedi- ments found in more recent groups. If we examine closely any of the unaltered groups, capable of being correlated by their fossils, we readily recognize some general mineral resemblances over very con- siderable areas, and Mr. Marr has particularly referred to some of these in his very excellent and highly suggestive paper. But there are, on the other hand, many minor differences, and this is especially the case where the sediments have been deposited in rather shallow water. For instance. the Harlech group at St. Davids and in the Harlech mountains is mainly composed of sandstones, whilst in Carnarvonshire it consists chiefly of slates, and in the north-west of Scotland of conglomerate and grits. Now if we suppose, as I believe was the case, that the Dimetian group was chiefly deposited in shallow water, the differences so well marked in the unaltered rocks of the Harlech group are exactly those which would, under the influence of metamorphism, produce a massive granitoidite at one place, a quartzose gneiss or micaceous schist at another, and yet a general resemblance indicating the prevalence of tolerably similar physical conditions at the time would be retained in the group in each area. On these considerations I think Mr. Marr was fully justified in classing the quartzose gneisses of Bohemia with the Dimetian rather 144 Correspondence—Mr. Jukes- Browne—Mr. Kinahan. than with any other known European Pre-Cambrian group, especially as he found them overlaid unconformably by rocks similar to those found in the Pebidian group. Certainly from his descrip- tions they could not be classed with the dark hornblendic and red eneisses which the Scotch geologists have invariably claimed to be characteristic of the Hebridean or Lewisian group. Moreover, the very fact that most of the gneisses in the central highlands were found, like the Dimetian of Wales, to be highly quartzose in character, formed one of the chief stumbling-blocks to their being recognized as of Pre-Cambrian age: even Nicol found this a difficulty. Now, however, since the Dimetian rocks in Wales have been recog- nised, this need offer no difficulty in future, and I feel convinced that ere long the Dimetian and Pebidian groups will be as easily separated from one another even ‘in Scotland as has been the case now in Bohemia through Mr. Marv’s researches. Henpon, N.W., Fed. 7, 1881. H. Hicks. - DISTURBANCES IN THE CHALK OF NORFOLK. Str,—I am indebted to Mr. H. B. Woodward for pointing out that Mr. J. E. Taylor was subsequently inclined to suggest a different age and cause for the disturbance at Whitlingham. This had escaped my notice, but supposing that Mr. Taylor’s later view, now endorsed by Mr. Woodward, is correct, it does not follow that all disturbances of the Chalk in Norfolk are due to the same cause. The passage of ice has no doubt disturbed and broken up the Chalk in many places; but I still submit that it is difficult to conceive of any surface agency being capable of producing such a sharp con- tortion in a solid scar of chalk like that at Trimmingham. A. J. JukES-BRowNE. Hieueate, Fed. 4. SHRINKAGE FISSURES. Sir,—I would direct the special attention of geologists to the chasms due to the subsidence in Cheshire; of which an excellent sketch recently appeared in the Graphic. From these shrinkage fissures we learn how gorges or canons can be made without denudation — because if such a small thing as the vacancy in a salt mine produces snch marked results, how much greater must be the results from vacancies caused by vulcanicity and other natural phenomena? ‘The sketch has an aspect very similar to some of the maps of cations in Dr. Hayden’s magnificent reports. G. H. Kinanay. We regret to record the death of two well-known and highly- esteemed geologists, namely :—Dr. J. J. Biespy, F.R.S., F.G.S. ; and Prof. Jamms Tennant, F.G.S. Notices of these veterans will be given next month. Geol. Mag /8E) Tho *Davidson de] & lth. M&N.Hanhart imp. Ue Ss LUE AN SBA iN One @iyAs THE GEOLOGICAL MAGAZINE. NEW SERIES, , DECADE LE, VOLia Vill: No. IV.—APRIL, 1881. ORIGINAL ARTICIES. I.—Desorretions of New Urrer Srinurian BracHIopopA FROM SHROPSHIRE. By Tuomas Davipson, F.R.S, (Concluded from p. 109.) (PLATE V.) 1. Waldheimia? Mawei,n. sp. Pl. V. Figs. 7, 8. HELL small, marginally sub-pentagonal, longer than wide, straight or slightly indented in front. Dorsal valve laterally gently convex, longitudinally concave, with a small median rib com- mencing at about the middle of the valve, and widening as it nears the front. Ventral valve very convex and keeled along the middle or divided longitudinally by a groove commencing at about half the length of the shell and extending to the front. Beak small, incurved, foramen minute, beak ridges strongly marked. Surface of valves smooth. In the interior of the dorsal valve, under the hinge-plate, a slightly elevated longitudinal septum or ridge extends to within a short distance of the frontal margin. To the hinge-plate are 16 17 attached the principal stems of the loop, which, after giving off crural processes, extend to with- in a short distance of the front, where they become reflected so as to form the loop. Length 2, breadth 14, depth 4 line. Obs.—This small shell was pro- cured in some abundance from the washings of the “Tick woodBeds,” or Upper Wenlock Shales, from under railway bridge at Farley Waldheimia Mawei, Dav. Developed by Dingle, also from the upper part Rev. N. Glass. of the Wenlock Shale, below limestone, water course, under Benthall Edge, and opposite Iron- bridge in Shropshire. Having placed in the hands of the Rev. Norman Glass a number of specimens filled with a light-coloured semi-transparent spar, he was able, after much trouble and patience, to develope the loop in several specimens, and in the clearest possible manner, and so like DECADE II.—yYOL. VIII.—NO. IV. 10 146 T. Davidson — Upper Silurian Brachiopoda. im general character is this loop to that of Waldheimia that I have provisionally placed it with that genus. LExteriorly this small species bears so much general resemblance to some forms of Centronella, and in particular to ©. Hecate, Billings (Canadian Journal, May, 1861,-p. 68), that previously to having been made acquainted with its loop I had placed the new English species in Billings’ genus. Centronella-is described by Prof. J. Hall (Sixteenth Annual Report of the Regents of the University of New York, p. 45, 1863) as consisting of two delicate riband-like Jamellee, which extend to about half the length of the dorsal valve. “These lamellee at first curve gently outwards, and then approach each other gradually, until at their lower extremities they meet. at an acute angle; then becoming united, they are reflected backwards towards the beak in what appears to be a thin flat vertical plate.” Now our small species does not show these characters, for in all the specimens developed by the Rev. N. Glass the extremities of the principal stems do not converge so as to become united at their lower extremities, but are wide apart, and instead of extending to only half the length of the shell, are prolonged to within a short distance of the frontal margin. The loop is not therefore that of Centronella as described by Billings and Hall. The genus Waldheimia had not hitherto been quoted as far down as the Upper Silurian. Terebratula and Centronella had been so, and we now know that species with short and long loops commence to appear in the Upper Silurian period. 2. Waldheimia ? Glassei, n. sp. | Pl. V. Fig. 6. Shell small, sub-pentagonal, broadest posteriorly, slightly truncated in front. Dorsal valve slightly convex, curving rather abruptly at the lateral margins, with a median longitudinal groove or depression, commencing about half the length of the shell, and extending to the front, beak incurved, truncated by a small foramen, hinge-ridges well defined, surface of valves smooth, marked by concentric lines of growth. Length 3, breadth 3, depth 2 lines. Obs.—About fifteen examples of this species were obtained by Mr. Maw from the washings of some seven tons weight of Buildwas Lower Wenlock Shales. All the specimens procured were of about the same dimensions, none exceeding the measurements above given. Only very few of them were in a perfect state of preservation, and none were in a suitable condition for Mr. Glass’s operations, consequently all his endeavours to develope its interior characters proved unsuccessful. It is a rather larger shell than Waldheimia ? Mawei, but bearing some resemblance to it in external shape; this has prompted me to leave it provisionally with that genus. Perhaps it may possess the interior characters of Centronella, and it will be very desirable to procure specimens suited to Mr. Glass’s operations. 3. Atrypa reticularis, Linné sp. At p. 9 of this paper I alluded to the interior characters of this abundant species. Having, thanks to Mr, Maw’s liberality, been T, Davidson— Upper Silurian Brachiopoda. 147 able to examine upwards of eight thousand specimens of the species from the Wenlock and Ludlow rocks of Shropshire, I have ascer- tained how much it varies in shape, and especially so at different stages of growth. The smallest or youngest examples measured not much more than half a line in length and breadth, and every stage was obtained up to shells measuring one inch and a half in length and breadth. When quite young the dorsal valve is flat or nearly so, with a strongly-marked longitudinal mesial depression; this same valve with age becomes gradually more and more convex or gibbous, and loses gradually all trace of the longitudinal depression. The front line is also either straight or more or less curved upwards, so much so that many specimens show in the dorsal valve a well-developed mesial fold, with a corresponding sinus in the yentral one. The ribbing varies also to a very considerable extent in different specimens. In young individuals the ribs are few in number, and in this condition it much approaches in shape and character to similar-sized examples of Atrypa Barrandi. The number of ribs seems also to increase rapidly with age. Some specimens with very convex dorsal valves are covered with numerous fine radiating ribs, while others of the same size show a much smaller number, and these more coarse and prominent. The concentric lines or squamose ribs due to growth are also much stronger, closer, or more wide apart in some individuals than in others, still all these individuals are linked one to the other by gradual passages. Feeling anxious to ascertain whether there existed interiorly any gradual increase in the number of spiral coils from the young up to the adult condition, I placed in the hands of the Rev. N. Glass a number of well-preserved specimens at different stages of growth, and some of which he kindly developed with his usual ability, and he was soon able to show, and in the: most distinct manner, that the number of coils in each of the vertical spiral coils increased with the growth of the shell. In a specimen measuring four lines in length and _ breadth there were only five convolutions in each spiral cone, and these Specimens much resemble those of Atrypa Barrandi, and in all probability, if not certainly, in still younger specimens Mr. Glass would have found not more than three or four coils. In a specimen measuring five lines in length he found six coils, in another six lines in length seven coils, and so on no doubt the increase would proceed up to fifteen convolutions in each spiral— the usual number found in full-grown specimens. Mr. Glass ascer- tained likewise that the basis of the spiral cones in young specimens with flattened dorsal valves is not level, the two inner sides of the principal coils being slightly higher than the two outer sides, and turned towards the margin of the shell—which is exactly what we have described and represented in Atrypa marginalis and Atrypa Barrandi, the dorsal valves of which are also nearly or quite flat (see pp. 10 and 11 of this paper). As the shell grows, and the dorsal valve becomes more convex, the basis of the spirals becomes 148 T. Davidson— Upper Silurian Brachiopoda. more level, and the spiral cones more elevated, as we have figured them in p. 9 of this paper. The principle of the variation of shape in the spirals of certain genera and species of the Atrypide, seems to be the providing of such a form of spirals as should allow the greatest length of coil possible in the interior of the shell ; for example, in Glassia obovata and G. elongata the ventral valve if anything is slightly more convex than the dorsal, and consequently the spirals are slightly more convex on the ventral side, and the length of the coils on that side is still further increased by the notch or indentation on the ventral slope of the posterior border of the spirals. Again, as we have just seen, in Atrypa marginalis, A. Barrandi, and in the young specimens of A. reticularis, the dorsal valve is nearly or quite flat, and this being the case there are several differences between their spirals and those in the full-grown specimens of A. reticularis, the dorsal valve of which is ventricose. First, there are a fewer number of spiral coils, but to allow space even for these some changes were necessary in the arrangement of the spirals, and therefore the principal coils instead of being level are slightly higher on their inner than on their outer sides, whilst, unlike the majority of the full-grown specimens of A. reticularis, the principal coils are some little distance apart, and the ends of the spirals bend over to meet each other. It will be seen at once that these peculiarities in the arrangement of the spirals (the coils being only few in number) make them on their dorsal side to be almost level, and suitable, therefore, to the interior space which they have to fill. ) Through the kindness of Mr. R. P. Whitfield, Mr. Glass and myself have been able to examine the only developed American example of Prof. Hall’s Celospira disparialis, from the collection of the American Museum of Natural History, New York, and we are able to assert that its characters and spirals are so exactly similar to those of Atrypa Barrandi, that we are strongly inclined to consider them as belonging to the same species, and both as referable to Atrypa. I have added these details to show how important it is to study the gradual development of a species from its youngest to its full-grown condition. 4, Glassia obovata, Sow., sp. Pl. V. Figs. 1, 2. Atrypa obovata, Sow., Sil. sp., pl. vill. fig. 9, 1839. We have already described the interior and character of this species. It is variable in shape, the valves being nearly equally and uniformly convex, and almost circular. ‘The front line is straight or slightly curved, surface smooth. Length 5, width 53, depth 3 lines. Glassia obovata is not an abundant species in Shropshire, but some good examples were obtained by Mr. Maw from the Buildwas Lower Wenlock shales. 5. Glassia elongata, n. sp. Pl. V. Figs. 3, 4. Shell small, elongated oval, valves very gently convex, straight, or slightly rounded in front, tapering posteriorly, broadest anteriorly, T. Davidson— Upper Silurian Brachiopoda. 149 beak small, incurved, surface smooth. In the interior of the dorsal valve the spirals are narrow anteriorly, but broader on the posterior side, and the principal coils on the posterior side of the spirals are, as in Glassia obovata, slightly notched or indented, the notch or indentation being in the direction of the end of the spiral, and occupying in most cases the whole breadth of the posterior border. The posterior border of the spirals, including, of course, the notch referred to, slopes slightly downwards on the ventral side towards the anterior margin, and arising from this the notch is partly seen in the ventral aspect of the spirals. This slope of the posterior border of the spirals also accounts for the upper part of the coils on the ventral side being more depressed and less oval than the correspond- ing part of the coils on the dorsal side. I here append a restored outline sketch of the arrangement of the Spiral coils of Glassia obovata. D dorsal, V ventral aspect. spiral coils in Glassia obovata, Fig. 18, from specimens developed by the Rev. N. Glass. The dorsal side of the coils in each spiral cone is somewhat displaced from its natural position in order to show the continuity of the coils. Fig. 19 shows that the coils are not circular, but elongated oval. 6. Meristella? or Atrypa ? Mawei, n. sp. Pl. V. Fig. 5. Shell almost circular, as wide as long, valves moderately convex ; ventral valve rather the deepest, no fold or sinus, but a slight longitudinal groove divides the dorsal valve into two equal lobes ; beak not much produced, with a small circular foramen. Surface of valves marked at intervals by a few slightly projecting concentric ridges. Length 6, breadth 6, depth 3 lines. Ols.—A single perfect specimen of this shell was found by Mr. 150 T. Davidson— Upper Silurian Brachiopoda. Maw among the debris from the old Wenlock limestone quarries at Benthall Edge in Shropshire. It is not possible to determine to what genus the shell should be referred, as its interior characters have not been ascertained, and it was not considered right to sacrifice the only specimen known in the attempt to discover the character of its spiral appendages. We have therefore provisionally put it with Meristella. It is with much pleasure that I name this new species after its indefatigable discoverer, and in remembrance of the great labour and liberality with which he has assisted me in getting up the material for this communication. 7. Streptis Graywi, Dav. Pl. V. Fig. 13. Atrypa ? Grayii, Day., Sil. Mon. pl. xiii. figs. 14-22. In 1846 I picked up two or three examples of this remarkable small twisted shell at Hayhead near Walsall, and described and figured it in 1848 in the Bulletin de la Soc. Geol. de France under the name of Terebratula Grayii. In 1859 Salter (in Siluria) made of it a Rhynchonella. Lindstrom in 1860 a Spirigerina? and in my Silurian Monograph I provisionally put it with Atrypa? adding, “my endeavours to procure specimens showing the internal character have proved fruitless, and I cannot determine exactly the genus.” Knowing little or nothing of its interior arrangements, I felt ex- tremely puzzled and uncertain as to the genus to which the shell should be referred, and, as justly remarked by Prof. James Hall at p- 38 of the 16th Annual Report on the State Cabinet of Natural History of New York, “so long as we remain unacquainted with the interior of the shell, we are compelled to refer the species to some genus having similar forms, though the fibrous or punctate struc- ture may in many instances prove a valuable aid in these references.” I have now seen upwards of one hundred and forty specimens of this remarkable species. and every individual presented exactly the same exterior character, and which I have described and represented at p. 141 and in pl. xiii. of my Silurian Monograph. Possessing, thanks .to Mr. Maw’s great liberality, a number of good examples, I sent some of them to the Rev. Norman Glass to operate upon, and after many experiments on perfectly preserved specimens filled with spar and suitable to his operations he has informed me that he could in none of them detect the slightest trace of any calcareous support for the labial appendages—not the trace of a loop or spiral skeleton, and he was of opinion that it could not be referred to any of the genera into which it had been provisionally located. I therefore propose provisionally to place it under a distinct genus, and have selected the name Streptis (twisted), all the specimens hitherto discovered having presented that character. No calcareous support for the labial appendages, cardinal process much produced, hinge-teeth large and prominent. 8. Rhynchonella cuneata, Dal. and His. Pl. V. Fig. 10. Sil. Mon. pl. xxi, figs. 7-11. Since describing this well-known species at page 164 of my T. Davidson— Upper Silurian Brachiopoda. 151 Silurian Monograph, Prof. J. Hall has, at p. 166 of the 'Twenty- Highth Annual Report of the New York State Museum of Natural History (1879), proposed a new genus, Rhynchotrete, for the reception of Dalman’s species, and which he characterizes in the following words :-— “Shell triangular, surface with angular plications, ventral beak straight, produced beyond the dorsal beak, extremity perforate, the foramen with an elevated margin; space between the foramen and the hinge-line occupied by a deltidium in two pieces, being divided by a longitudinal suture, and transversely striated. Valves articulated by two slender curving teeth, proceeding from a broad curving hinge-plate in the ventral valve, which fit into corresponding sockets in the dorsal valve. Crure rising from near the dorsal beak and curving into the ventral cavity, and thence recurved towards the dorsal side, and probably uniting, as shown in fig. 4 (Fig. 11 of our Plate). Structure fibrous and apparently very minutely punctate.” It seems quite evident that Prof. Hall has not actually seen the short Terebratula-shaped loop represented in his restored fig. No. 4 (Fig. 11 of our Plate), for he says in his description, “and probably uniting, as shown in fig. 4”’—and in the explanations of his fig. 4 he adds, “the additional features of the loop represented in this figure have not as yet been satisfactorily determined.” In order, if possible, to ascertain the internal character of this species, I asked the Rev. Norman Glass to develope the interior of several well- preserved specimens of Rh. cuneata from the Wenlock Limestone of Benthall Edge, and all of them showed only the two small curved lamelle not attaining a third of the length of the dorsal valve, as in Rhynchonella proper. In no instance did Mr. Glass discover any indication of a loop. I would therefore leave Dalman’s species with Rhynchonella until, on positive evidence, it can be shown to be generically separable. 9. Rhynchonella Dayi, sp. Pl. V. Fig. 9. Obtusely deltoid or sub-pentagonal, wider than long, valves moderately convex, and divided into three almost equal lobes. Ventral valve not quite as deep as the dorsal one, divided by a broad well-defined mesial sinus, beak small, showing a small circular foramen margined by a deltidium, surface of valves ornamented with some fourteen or sixteen angular ribs. of which four form a well- defined mesial fold, the ribs being slightly bent upwards at the front, lateral margins of fold wide and flat. Length 54, width 6, depth 34 lines. Obs.—This small species is well distinguished from young specimens of the same age of Rh. borealis, with which it had been confounded by its less triangular shape, as well as by the ribs of its fold being bent upwards close to their frontal extremity. In size and in number of ribs Ah. Dayi somewhat resembles small examples of the Jurassic /’h. tetraedra. This small species was found by Mr. George Maw in the Wenlock Limestone of Benthall Hdge, as well as in the Wenlock Shales 152 T. Davidson— Upper Silurian Brachiopoda. underlying the limestone. JI have much pleasure in naming it after the Rev. H. G. Day. 10. Orthis elegantulina, n. sp. Pl. V. Fig. 12. Shell small, nearly circular, and about as broad as long. Dorsal valve moderately convex, divided longitudinally by a sinus of greater or lesser depth. Hinge area narrow. Ventral valve deeper, and more convex than the dorsal one, and slightly longitudinally keeled. Hinge-line shorter than the breadth of shell, beak small, incurved, area triangular, fissure small. Surface of both valves marked by strong raised stria, bifurcating once or twice as they near the lateral and frontal portions of the valves. Length 3, width 3, depth 2 lines. Obs.—My attention was first drawn to this small species at the commencement of 1880 by Mr. J. F. Walker. It is a much smaller shell than Orthis elegantula, and more circular, its beak much less incurved and of smaller proportions, and its ribbing or striation comparatively much stronger than in O. elegantula. O. elegantulina swarms in the Lower Wenlock Shales of Buildwas in Shropshire, and is less abundant in the Upper Wenlock Shales. 11. Kichwaldia Capewelli, Day. sp., Sil. Mon. p. 193, pl. xxv. figs. 12, 15. Ever since I first described this beautifully sculptured shell in 1848, I have felt uncertain whether it was provided with spiral appendages. I consequently placed in the hands of Mr. Glass a number of well-preserved specimens filled with spar, and which had been obtained by Mr. Maw from his washing of Buildwas Lower Wenlock Shales. After many experiments not the trace of . a spiral coil could be detected, and Mr. Glass arrived at the con- clusion that it had none. Prof. J. Hall having kindly sent me several well-preserved specimens of his Hichwaldia reticulata, I am convinced that it is the same species as my EH. Capewelli. At page 170 of the Twenty- Highth Report of the New York State Museum of Natural History, Prof. Hall says, “Surface of the shell, except a small place on the umbo of the ventral valve, covered by fine reticulate markings with elongate, generally hexagonal pits or openings, with thin and sharp ridges within ; these markings vary in different specimens, and also in different parts of the same individual, being generaily finest on the cardinal slopes. The small triangular space near the ventral beak which is destitute of marking has the appearance of having been exfoliated ; but since this is an invariable character in all the individuals examined, varying in size with the size of the shell, it is probably dependent upon organic causes.” ‘This description of the shell sculpture, and of the smooth part at the umbo of the ventral valve, is exactly what we find, not only in our British specimens, but also in Swedish ones; and in pl. 2, fig. 16, of his ‘‘ Fragmenta Silurica,” Prof. Lindstrom gives a good illustration of this peculiarity. T. Davidson—Upper Silurian Brachiopoda. 153 12. Streptorhynchus nasutum, Lindstrom. Cyrtia ? naswta, Day., Sil. Mon. p. 201, pl. xxv. figs. 1, 2. For a long time much uncertainty has prevailed with respect to the genus to which this remarkable species should be referred. It was in 1860 described by Prof. Lindstrom as a Strophomena, but the fortunate discovery of perfect interiors of Swedish examples has enabled Prof. Lindstrom to place this shell in King’s genus Streptorhynchus. Prof. Lindstrom’s beautiful figures in pl. xvii. of his work ‘“‘Fragmenta Silurica” clear up all uncertainty in the matter. This little shell appears still to be very rare in Great Britain, for I am acquainted with four specimens only. One of these was found by the Rev. H. G. Day in the Wenlock Limestone of Benthall Hdge, another in the same limestone at Dudley, and the two specimens have been liberally presented to me by their discoverer. 13. Genus Uncires, Defrance, 1828. For many years past I have been on the look out for specimens that would clear up the interior characters of Defrance’s Devonian genus. In 1853, in the General Introduction of my work on « British Fossil Brachiopoda,” I described and figured part of the interior of the dorsal valve, showing the lateral pouch-shaped cavities opening exteriorly, as well as the attachments to the hinge- plate of the principal stems of the spiral appendages, also indications of the spiral appendages from a specimen which Prof. Beyrich of Berlin was so fortunate as to discover at Paffrath, and which was brought to my notice by Prof. H. Suess of Vienna. In 1871, Prof. Quenstedt, in pl. 43 of the Atlas to his ‘Die Brachiopoden ” (Petrefactenkunde Deutschland), figures spiral coils in a specimen of Uncites. No one, as far as 1 am aware of, seems to 20. Specimens of Uncites gryphus in the Imperial Museum of Vienna. 21. Restored interior of the dorsal valye. @ cardinal process; 4 principal stems of spirals; ¢ connecting lamell ; d spirals; e pouch-shaped expansions. 154 T. Davidson— Upper Silurian Brachiopoda. have described the mode in which the spirals were connected. After many inquiries in different directions, Prof. Zittel informed me that he believed there existed in the Imperial Museum of Vienna some specimens that might help in this investigation, and ac- cordingly my old and valued friend Prof. Suess at once kindly obtained for my inspection the important specimen, Fig. 20, and in which are seen, not only the attachments of the principal stems of the spirals to the hinge-plate, but likewise their connection by the means of a curved bridge-like process, and which connects them at about half their length—small portions of the spirals themselves being also visible. We are likewise indebted to Mr. A. Champernowne of Dartington Hall, Totness, not only for the discovery of the first British specimen of the genus, but also for finding a specimen showing the cardinal process, which in Uncites gryphus is heart-shaped and strongly developed. This valuable specimen was presented to the Albert Memorial Museum, Exeter, by its discoverer. I am now, therefore, for the first time able to offer a correct restoration of the interior of the dorsal valve (woodcut, Fig. 21). Mr. Champernowne informs me that in addition to the locality, Orchard Quarry, Dartington, Mr. P. Vicary has obtained two specimens from the Chudleigh Limestone in Devonshire. We still remain unacquainted with the shape and position of the muscular impressions, but these will, in all probability, be some day discovered. EXPLANATION OF PLATE Y. -2. Glassia obovata, Sow. sp. 4 elongata, Day. The interiors of the valves or spirals are seen as a transparency. Meristelia 2 Mawei, Dav. Waldheimia? Glassei, Dav. — Mawei, Dav. Rhynchonella Day, Day. 0-11. ——-—- cuneata, Dalman.: 10 shows two short curved lamelle only, as developed by Rey. N. Glass. 11 is taken from Prof. Hall’s restored figure in p. 166 of 28th Annual Report of the New York Museum of Natural History. sal ee Orthis elegantulina, Dav. op bBo Streptis Grayi, Davy. Norr.—In the first part of this paper, published in the January Number, I stated that Mr. Whitfield “had been engaged in develop- ing the spirals and their connections in the Paleozoic Brachiopoda, but only in American specimens, and principally in siliceous shells or in shells possessing a hard limestone matrix.” I also stated that “Mr. Glass’s operations had been confined almost entirely to English specimens, and to those English specimens only which were partly or wholly filled with spar.” In my Carboniferous Supplement, published at the commencement of last year, I also stated that ‘some finely worked out specimens of American Palaeozoic Spirifers, and other genera, have been described and illustrated by Prof. Hall and Mr. Whitfield; but in this case the results were obtained T. Davidson— Upper Silurian Brachiopoda. 155 principally in siliceous specimens or by sections, and not developed in spar by the process Mr. Glass has discovered.” I have recently received a note from Mr. Whitfield, in which he informs me that in the above statements I have been labouring under a mistake, that the siliceous specimens he has worked out are comparatively few, and that he has principally operated on specimens filled with calc-spar— these operations extending back for some years, and relating not only to American, but also to a number of European forms, including some from Bohemia and England. He says, ‘‘In fact I have treated my specimens exactly as Mr. Glass has treated his.” Mr. Whitfield thus describes his method of operating-—‘‘I have been in the habit of cutting down to near the spires with tools, then treating with hydrochloric acid to render them more translucent, frequently cutting longitudinally a little outside of the middle so as to get the loop in profile. Athyris vittata, A. spiriferoides, Meristina nitida, and M. Maria are all cut thus.” Mr. Whitfield also refers to a friend of his as having operated in a similar manner upon American specimens of Atrypa reticularis, and upon Huropean specimens of Tereb. scalprum. Mr. John Young, of the Hunterian Museum, Glasgow, has also, in the course of correspondence, informed Mr. Glass that more than twelve years ago he operated upon four specimens—three of Athyris ambigua, and one of A. Roysii—developing the spirals from their sparry matrix by means of acid and a file and knife. More recently, as I stated in my Carboniferous Supplement, Mr. James Neilson, Jun., has developed in the same manner the spirals in A. Roysii and Sp. lineata. As to the English forms worked out by Mr. Whitfield, I may state that I have never seen any drawings of them—my knowledge of the spirals and their connections in those of our English Brachiopods which are filled with spar having been entirely derived from the preparations of Mr. Glass. Mr. Glass, as he informs me, does not lay any claim to the discovery that the Paleeozoic spiral- bearing forms of the Brachiopoda which are filled with spar are favourable to the development of the spirals and their connections, nor does he lay any claim to the first employment for such a purpose of the knife supplemented by acid—though he was the first to publish any account of such a process, and it was only after he had done this that he became aware of its previous use. He thinks, however, that his own method is somewhat different to that previously employed. In the comparatively simple matter of developing the spirals Mr. Glass has found through operating upon many hundreds of specimens that to obtain the best and most finished results the acid should first be used in removing the outer valve or valves when they have not been transformed into spar. That then scraping with a knife and frequent washing with water must be solely relied upon until the spirals are clearly revealed without even a trace of the sparry matrix upon them. ‘Then to obtain a perfectly smooth surface, fine emery cloth must be used, and finally the specimen must be dipped for two or three seconds in the acid to remove the dullness of the surface and to give to it a glossy and transparent appearance as if it 156 G. MW. Dawson—Geology of British Colunbia. had been polished. As to the more difficult matter of developing the connections of the spirals, Mr. Glass has found that the only method giving any certainty of result is by limiting the use of the acid as described above and by scraping away the matrix and parts of the spirals until the connections of the spirals with the hinge- plate, and the connection of the spirals with each other are com- pletely exposed. Mr. Glass says that in his own operations he places no dependence upon the making of sections, though he has no doubt that those who have a preference for this mode may sometimes use it with good effect. Since writing the above Mr. Whitfield has kindly forwarded to me a specimen of Meristella arcuata in which the spirals and their connections are silicified. Mr. Whitfield only partly prepared this specimen, so that the very delicate and fragile loop might be preserved during transit, and said in his accompanying note—‘‘It will need careful working with acid in order to develop it so as to shew the loop rings and processes.” Having sent the specimen to Mr. Glass he has successfully worked it out, and the rings of the loop appear very plainly as previously figured by Prof. Hall. Now as in Meristella tumida there are no rings it cannot properly belong to the genus Meristella. Mr. Whitfield agrees with me in thinking that it is identical with the American Meristina Maria. Certainly Meristina Maria agrees very closely with our Meristella twmida in external form, and Mr. Glass has just worked out a typical specimen of the American species sent to me by Prof. Hall which proves beyond doubt that the connections of the spirals with the hinge-plate and their connection with each other are identical in both species. In the American description of the interior of Meristina Maria the loop is said to be simple, but it is now proved that the end of the loop is bifurcated in exact agreement with the figure of the interior of Meristella tumida given in the first part of this paper. Mr. Glass has worked out a specimen of Meristella didyma, which is probably identical with the American Meristina nitida. In this specimen Mr. Glass thinks he has developed a simple loop such as that described by Prof. Hall for his genus Meristina. I am not quite sure of this, however, and think it desirable that we should have further evidence, but if Mr. Glass’s supposition should prove correct, then the genus JJeristina should be retained for this and similarly organized species, and Meristella tumida, with its synonym Meristina Maria, should constitute a new genus which 1 would name Whitfieldia. IJ.—Sxeronu or tHe Groitocy or British CoLnumBia. By Gzorcz M. Dawson, D.S., A.R.S.M., F.G.S. WENTY years ago the region now included in the Province of _ British Columbia was—with the exception of the coast-line— little known geographically, and quite unknown geologically. From the days of Cook and Vancouver, and the old territorial disputes with the Spaniards, this part of the west coast of North America G. M. Dawson—Geology of British Columbia. 157 attracted little attention till the discovery of gold in 1858. As among the first in the field geologically may be mentioned Dr. Hector and Messrs. H. Bauerman and G. Gibbs. The observations of these gentlemen, though bringing to light many facts of interest, were confined to a comparatively small part of the area of the province, and it was not till the inclusion of British Columbia in the Dominion of Canada in 1871 that the systematic operations of the Geological Survey of Canada were extended to this region. Since this date a number of reports treating of the geology of British Columbia have been published, and on these, together with a per- sonal knowledge of the country, obtained during five seasons’ work in it in connexion with the Survey, I shall chiefly depend in giving a brief account of the main geological features so far developed. British Columbia includes the whole breadth of a portion of the great Cordillera belt which forms the Pacific margin of the Con- tinent. This here consists of four parallel mountain ranges running in general north-westerly and south-easterly bearings, which, be- ginning on the Pacific Margin, may be named as follows :—Van- couver Range, Coast or Cascade Range, Gold Range, and Rocky Mountain Range proper, the last constituting the western border of the great plains of the interior of the Continent. The first mentioned, in a partially submerged condition, forms Vancouver and the Queen Charlotte Islands, and still rears some of its peaks to a height surpassing 6000 feet, The valley lying to the north-east of this is occupied by the sea, forming the Strait of Georgia, Queen Charlotte Sound, and Hecate Straits. The Coast Range is a rugged mountainous district with a width of about one hundred miles, and axial summits reaching in some places elevations surpassing 8000 feet. To the north-east of this stretches a region which may be called the Interior Plateau of British Columbia, the average width of which is nearly one hundred miles, and its mean elevation about 8500 feet. This plateau is, however, irregular, hilly, or even in some places mountainous, and is intersected by deep trough-like river valleys. It is only when it is occupied by Tertiary volcanic rocks that it assumes considerable uniformity of surface. : Bounding the plateau to the north-east is a third wide range, known locally as the Cariboo, Columbia and Purcell Mountains. It is broken to the north at the 54th parallel and resumes under the 56th as the Omineca Mountains. This mountain axis may be named the Gold Range, and it is probable that many summits in it surpass 8000 feet. Separated from it by a narrow but well-defined valley is the Rocky Mountain Range with an average width of fifty to sixty miles. ‘This shows peaks of about 10,000 feet in height on the 49th parallel, is supposed to surpass 15,000 feet near the 52nd, and becomes comparatively low and narrow in the vicinity of the Peace River, about the 56th parallel. Such are the main orographical features of British Columbia, a slight knowledge of which is necessary to render intelligible the description of its geological structure. 158 G. MW. Dawson—Geology of British Columbia. In describing the rocks, those of Tertiary and Cretaceous age of the coast will first be noticed, next those of the interior of the pro- vince referable to these periods, and lastly the older underlying metamorphic rocks. Tertiary.—The Tertiary rocks do not form any wide or continuous belt on this part of the coast, as is the case farther south. They are found near Sooke, at the southern extremity of Vancouver’s Island, in the form of sandstones, conglomerates, and shales, which are some- times carbonaceous.’ Tertiary rocks also probably occupy a consider- able area about the mouth of the Fraser River; extending southward from Burrard Inlet, across the International boundary formed by the 49th parallel, to Bellingham Bay and beyond. Thin seams of lignite occur at Burrard Inlet. Sections of the Tertiary rocks at Bellingham Bay are given in Dr. Hector’s official report. Lignite beds were here some years ago extensively worked, but the mine has been abandoned owing to the superior quality of the fuels now obtained from Nanaimo and Seattle. About the estuary of the Fraser the Tertiary beds are much covered by drift and alluvial deposits, and are consequently not well known. Lignites, and even true coals, have been found in connexion with them, but so far in beds too thin to be of value. Fossil plants from Burrard Inlet and Bellingham Bay have been described by Newberry and Lesquereux, and these are supposed to indicate a Miocene age for the deposits.’ Much farther north, in the Queen Charlotte Island, the whole north-eastern portion of Graham Island has now been shown to be underlain by Tertiary rocks, which produce a flat or gently un- dulating country, markedly different from that found on most parts of the coast. The prominent rocks are of volcanic origin, including basalts, dolerites, trachytic rocks, and in one locality obsidian. Numerous examples of fragmental volcanic rocks are also found. Below these, but seen in a few places only, are ordinary sedimentary deposits, consisting of sandstones or shales, and hard clays with lignites. Ata single locality on the north end of Graham Island, beds with numerous marine fossils occur. These, in so far as they admit of specific determination, represent shells found in the later ‘Tertiary deposits of California, and some of which are still living on the north-west coast; and the assemblage is not such as to indicate any marked difference of climate from that now obtaining.® The Tertiary rocks of the coast are not anywhere much disturbed or altered. The relative level of sea and land must have been nearly as at present when they were formed, and it is probable that they originally spread much more widely, the preservation of such an area as that of Graham Island being due to the protective capping 1 Report of Progress, Geol. Survey of Canada, 1876-77, p. 190. 2 In the geology of the U. 8, exploring expedition, Prof. Dana describes some Tertiary plants from Birch Bay. These were afterwards reported on by Newberry, Boston Journ. of Nat. Hist. vol. vii. No. 4. See also American Journal of Se. and Arts, 2nd series, vol, xxvii. p. 359, and vol. xxviii. p. 85. Report on the Yellow- stone and Niusain expedition, 1869, p. 166. Annals Lye. of Nat, Hist. of N. Y,, vol. ix. April, 1868. 3 Report of Progress, Geol. Survey of Canada, 1878-9, p. 84 B. G4. M. Dawson— Geology of British Columbia. 159 of voleanic rocks. The beds belong evidently to the more recent Tertiary, and though the paleontological evidence is scanty, it appears probable from this, and by comparison with other parts of the west coast, that they should be called Miocene. To the east of the Coast or Cascade Range, Tertiary rocks are very extensively developed. They have not, however, yielded any marine fossils, and appear to have been formed in an extensive lake, or series of lakes, which may at one time have submerged nearly the entire area of the region described as the interior plateau. The Tertiary lake or lakes may not improbably have been produced by the interruption of the drainage of the region bya renewed elevation of the coast mountains proceeding in advance of the power of the rivers of the period to lower their beds; the movement culminating in a profound disturbance leading to very extensive volcanic action. The lower beds are sandstones, clays, and shales, generally pale-greyish or yellowish in colour, except where darkened by carbonaceous matter. They frequently hold lignite, coal, and in some even true bituminous coal occurs. These sedimentary beds rest generally on a very irregular surface, and consequently vary much in thickness and character in different parts of the extensive region over which they occur. The lignites appear in some places to rest on true “underclays,” representing the soil on which the vegetation producing them has grown, while in others—as at Quesnel—they seem to be composed of drift-wood, and show much clay and sand interlaminated with the coaly matter. In the northern portion of the interior the upper volcanic part of the Tertiary covers great areas, and is usually in beds nearly horizontal, or at least not extensively or sharply folded. Basalts, dolerites, and allied rocks of modern aspects occur in sheets, broken only here and there by valleys of denudation; and acidic rocks are seldom met with except in the immediate vicinity of the ancient volcanic vents. On the Lower Nechacco, and on the Parsnip River, the lower sedimentary rocks appear to be somewhat extensively developed without the overlying volcanic materials. The southern part of the interior plateau is more irregular and mountainous. The Tertiary rocks here cover less extensive areas, and are much more disturbed, and sometimes over wide districts— as on the Nicola—are found dipping at an average angle of about thirty degrees. The volcanic materials are occasionally of great thickness, and the little disturbed basalts of the north are, for the most part, replaced by agglomerates and tufas, with trachytes, porphyrites, and other felspathic rocks. It may indeed be questioned whether the character of these rocks does not indicate that they are of earlier date than those to the north, but, as no direct paleontological evidence of this has been obtained, it is presumed that their different composition and appearance is due to unlike conditions of deposition and greater subsequent disturbance, No volcanic rocks or lava flows of Post-glacial age have been met with, though I believe that still farther to the north-west the rocks are of yet more recent origin than any of these here described, and HN ed = i al in — — pal Loman _ =A = S S *S S) cS a) = = —Q > > S aS S iS) ida) l S a SS Ss Q S —— iZ Li NG es %3 161 SHY OO1 ! 1 ’ i | | AIVIS IVLINOZIXOFT S *snorajtuoqied y1ed ur ‘o10zoa]eg sozizj1engd puesysiqos ‘guojsoulry ° aS } = ‘A1QUNOD JOATY Ove OY} FO SYIO1 SNOVdvAOID “11 *SYIOI D1UvITOA AreIWOT, JO si1o1[jNO * rS *so[eYS SIJOUOJ OISSIIT, “Or ‘oye * iS) *d10Z0@] 8g $9z1ZjIVNQ pue szsigoG ‘sauojzsouny °6 *s[eod oinduirt yyIM ‘sazz[g pue soleys ‘SoUOJSpues SNnOdd¥I0I_5 * aS +2 "(¢) Ossvlty, SoyeZ]S pue szsIGOS “g *OPIULID * ae *(2) UeRyorVy YSIYIS Bow pue ssioux ouljeysArD ATYStPy 2 “SOSUBY YSLOD OY} JO S}sIYOG-epue[quioy pure -vorur SSIOUD * II Or 6 L 9 S + € Zz I sulejunoyy, Ayo yY F SEU EIU SA eral Sosury 4SEOD G. M. Dawson—Geology of B “TATIVUVd wi8S AHL 4O ALINIOIA FHL NI NOIOAM VUATTIGUOOD AHL SSOWOV NOILOUS HOLUNS Osis OTT ND. yseod oye eae 11 DECADE If.—VOL. VIII.—NO. IV. 162 Prof. J. D. Dana—Metamorphism of I have even heard a tradition of the Indians of the Rasse River which relates that, at some time very remote in their history, an eruption covering a wide tract of country with lava was witnessed. The organic remains so far obtained from these Tertiary rocks of the interior consist of plants, insects, and a few freshwater molluscs and fish scales, the last being the only indication of the vertebrate fauna of the period. The plants have been collected at a number of localities. They have been subjected to a preliminary examina- tion by Principal Dawson, and several lists of species published. While they are certainly Tertiary, and represent a temperate flora like that elsewhere attributed to the Miocene, they do not afford a very definite criterion of age, being derived from places which must have differed much in their physical surroundings at the time of the deposition of the beds. Insect remains have been obtained in four localities. They have been examined by Mr. 8. H. Scudder, who has contributed three papers on them to the Geological Reports,’ in which he describes forty species, all of which are considered new. None of the insects have been found to occur in more than a single locality, which causes Mr. Scudder to observe that the deposits from which they came may either differ consider- ably in age, or, with the fact that duplicates have seldom been found even in the same locality, evidence the existence of different sur- roundings, and an exceedingly rich insect fauna. Though the interior plateau may at one time have been pretty uniformly covered with Tertiary rocks, it is evident that some regions have never been overspread by them, while, owing to denudation, they have since been almost altogether removed from other districts, and the modern river valleys often cut completely through them to the older rocks. The outlines of the Tertiary areas are therefore now irregular and complicated.” (To be continued in our next Number.) IlJ.—On a CAsE IN WHICH VARIOUS MASSIVE CRYSTALLINE Rocks INCLUDING Sopa-GRANITE, Quartrz-Diorirz, Noritz, Horn- BLENDITE, PyYROXENITE, AND DIFFERENT CuRysouitic Rocks, WERE MADE THROUGH METAMORPHIC AGENCIES IN ONE Mrra- MORPHIC PROCESss. By Prof. James D. Dana, LL.D., A.M., For. Memb. Geol. Soc. Lond., of Yale College, New Haven, Ct., U.S.A. Part III. (Concluded from page 119.) IV\.HE extent of these bands, their number, uniformity of direction | and apparently of dip, and the identity of the material con- stituting them with beds of the schist, especially the more northern, are such as to warrant the following section (Fig. 15). 1 Reports of Progress, Geol. Survey of Canada, 1875-6, p. 266 ; 1876-7, p. 457; 1877-8, p. 175, B. : 2 For additional information on the Tertiary rocks of the interior, see the following Reports of Progress, 1871-2, p. 56; 1875-6, pp. 70 and 225; 1876-7, pp. 75 and 112, B. Massive Crystalline Rocks. 163 A B represents a portion of the schist near the granite; B to C, soda-granite ; C to D, coarse syenite-like diorite; D to H, soda- Sranite; a to f, the bands, which are lettered as in the above de- scriptions of them. Fie. 15. AB 6} D E The depth to which the beds are made to descend downward in the granite (100 feet) is an assumption in this section; but con- sidering that probably 5000 feet, and more likely over 10,000 feet of these upturned rocks have been removed by erosion, and noting also the number of the bands and their parallelism to the schist, and the effect of pressure to keep them in place, the assumption can be no exaggeration. Since it is obviously impossible that the inclusions taken in and carried up by rocks erupted through deep fissures should be beds of schist 100 to 200 feet long, and a series of such beds separated by the fused rock retaining together their parallel position, we have to admit that these indications of bedding are of unobliterated bedding. The rest of the upturned strata were fused or at least softened ; these portions of beds were not fused, though flexed and variously displaced. There is reason for the resistance to fusion in the mineral nature of the beds; for quartz, staurolite, fibrolite, magnetite, are infusible minerals; muscovite and biotite are but slightly fusible on thin edges; and orthoclase fuses with great difficulty, much greater than the other felspars, oligoclase, labradorite and albite. Thus the study of the phenomena of contact becomes in this region a study of ‘inclusions ”’; and the larger of the inclusions turn out to be beds of schist, conformable to the schist. We seem to be thus forced to the conclusion that the soda-granite and the included diorite were once parts of the same sedimentary strata with the schist, and that all, with the Cruger limestone, were once a continuous stratified formation; and that the plasticity given to the granite-making or diorite-making portions, because of the heat, occasioned the exceptional geological features of the region. The region of Cruger’s Point is continued northward into that of Montrose Point; the latter is characterized, as has been stated, by chrysolitic rocks for its southern three-fourths, and by norite with chrysolitic rock for the other fourth; and through the facts there as well as elsewhere afforded, the evidence from inclusions is made to extend also to these other rocks. With the chrysolitic pyroxenite and chrysolitic hornblendite, there is also hornblendite which is not chrysolitic, but more or less augitic, and containing some triclinic 164 Prof. J. D. Dana—Metamorphism of felspar. On the south side of Montrose Point facing Cruger’s Point (or the brick-yard between the two), in the chrysolitic rock, there is what looks like a vein or dyke two to four inches wide, exposed for a length of twenty feet. The material shows it to be no vein or dyke, but a bed from the schist; it is a dark-coloured quartzose garnet rock, heavy with magnetite and containing some staurolite, resembling much a portion of the schist in section 1 (above de- scribed), near the soda-granite. The covering of earth prevented a determination of its whole extent. Jn the same kind of rock, about fifty yards north of the brick-yard which divides Montrose Point (into a North Montrose and a South Montrose Point), a vein-like band, two feet to twenty inches wide, descends the bluff, which consists of a light-grey massive argillite. Examined in thin slices by the microscope, it is found to have a mealy aspect with microlithic points, like an argillite in the first stages of metamor- phism. The band is a bed from the schist, although a different variety of it from any exposed at Cruger’s. Other long vein-like bands are black and of very fine grain; some of them look greyish and minutely arenaceous. The micro- scope shows, on an examination of thin slices, that some consist of grains of hornblende and felspar, the latter partly orthoclase, and look like hornblende schist, while others are very fine-grained hornblendic mica-schist. One of the latter had a thickness of two feet. These bands are most numerous in the norite of the northern part of the pomt. Figure 4, as stated on page 111, represents an “inclusion” in the norite; but the inclusion is evidently a bed bent back on itself; for a vein would not be thus folded double in its enclosing rock. The rock of this bed much resembles the norite, though finer in grain, and consists (as observed by means of a thin slice) of hornblende with much augite and some triclinic felspar. On the same part of the point, the norite and chrysolitic rocks apparently cut through one another, but with the norite oftener lke au inclusion in the chrysolitic rocks. Again, they follow one another, or lie side by side, but without a distinct divisional plane ; and in one place the rock consists of bands of norite and chrysolitic hornblendite without a trace of any planes of separation. Figure 16 represents an example of this kind, in which the bands are two to three inches wide, norite bands (the fine-dotted in the figure) alternat- ing with bands of the chrysolitic rock. Difference of material in successive portions might, under some metamorphic conditions, give rise to such a structure, although the bands are so thin; successive ff < sf alstSe outflowing of different eruptive rocks could not produce it. Going north from the vicinity of Cruger’s Station along section 1, instead of section 3, the rocks change from the coarse diorite at Fie. 16. Massive Crystalline Rocks. 165 the end of the section to fine-grained ; and then, in three-fourths of a mile, the rock is well-characterized norite. Moreover, the norite contains a band of magnetite, exposed in a working (near Mrs. Murden’s) with which occur garnet and fibrolite. The band is bedded, the magnetite is chloritic, and the assemblage of minerals is the same that occurs in the soda-granite, as well as the schist west of Cruger’s. Fibrolite is found also with the magnetite of Eastern Cortland. The norite and chrysolitic rocks are thus apparently in the same category with the soda-granite and quartz-diorite. Stony Point.—This conclusion is further sustained by the facts to be observed at Stony Point, and these facts come into this place, although the locality is on the west side of the Hudson; for tbe Cruger schists make the south border of the region precisely as near Cruger’s, and have the same strike and dip, showing a like relation to the Cruger limestone belt and proving its former extension across the river. For further comparison between the geological facts of the east and west sides of the river, it is to be observed that the succession of rocks west of Cruger’s, on the line going northward, from the river on the south side of the point to the north side of Montrose Point, is (1) limestone; (2) schist; (3) soda-granite (with some included diorite) ; (4) chrysolite rocks ; (5) (on Northern Montrose Point) norite and chrysolitic rocks in complicated combination. The same is the order on Stony Point, except that the limestone is not in sight (no doubt because submerged) ; it is: (2) schists ; (8) soda-granite; (4) chrysolite rocks, followed by (8) norite and chrysolite rocks combined. (The diorite of the Cruger soda-granite is not represented there.) On the map, 2 is the area of the schists ; y, the soda-granite; z, the chrysolitic rocks, and z'the latter with norite. But besides being the same in order, there is evidence that the soda-granite succeeds the schist along a plane of bedding of the schists, as if conformable. This is apparent at the junction of the two on the east-north-east shore of the point. Included beds of schist occur, but the covering of earth prevents a determination of their direction. Further, the chrysolitic rocks succeed to the soda- granite along a plane parallel to the same plane of bedding, as is seen just west of the boat-pier near the middle of the northern shore. Besides these facts, there are included beds of fine-grained hornblende rock (schist ?) and other kinds in the norite and chrysolitic rocks, which are in general conformable to the same plane, or about N. 70° E. in strike, with a dip of 75° to 80° to the northward. Such facts sustain the inference as to the former connexion of the rocks of the east and west sides of the river, and strongly favour the view that the succession in the rocks noted was dependent originally on stratification. Tf the thickness of the schists at Cruger’s Point may be taken as that at Stony Point, the submerged Cruger limestone is to be found beneath the bottom mud of the river within a few hundred feet of the south-east shore. 166 Prof. J. D. Dana—Metamorphism of (2) Vicinity of the Peekskill Limestone areas.—The Peekskill limestone areas have similar stratigraphical relations to the norite and the other Cortland rocks. One of the two areas extends up Sprout Brook or Canopus Hollow, and the other up the valley in the village of Peekskill along which Center-street descends toward the river. The southern extremities of these areas are shown on the map, page 60; the former has the strike N. 52° EH. and dip 75° S.; the latter N. 78° HE. dip 75° 8. Figure 17 represents a section Fie. 17. a Ob ed Oi G & about 1300 yards in length from north to south, along the line marked a b ¢ on the map, starting from the limestone at the mouth of Sprout Brook, near the Ironworks. The limestone (a) lies against true, whitish, well-bedded, conformable quartzite (a to b) ; this quartzite changes gradually to jointed massive granitoid and gneissoid quartzite, with only an occasional bedded band or plane ; each such band or plane is conformable in direction to the limestone and the adjoining bedded quartzite. This quartzite (the rock referred to on p. 24, vol. xx. Am. Jour. Sci.) continues southward to the Center-street valley, but on the north side of the valley, just back of Hill’s Foundry, it is followed by an arenaceous mica-schist (c d), with the strike varied to N. 78° EH. the dip remaining the same; then, on the south side of the valley, 50 yards above Baxter’s Iron Works (on Water-street), the limestone of the second belt outcrops, having the same dip and strike as the mica-schist ; and behind these ironworks, thin-fissile dark-grey mica-schist (containing both white and black mica) appears conformable in position to the limestone ; then, after an earth-covered interval of about 200 yards, there is an outcrop of massive norite along South-street, north of Hudson- street, which is without bedding, but has an extremely micaceous layer—a kind of coarse mica-schist—intersecting it near its middle, which is conformable in its strike and dip with the mica-schist and limestone of Center-street valley; and it shows conformable planes of bedding also near its south extremity. Moreover, this norite has a lighter-grey colour and contains more quartz and orthoclase than in other outcrops more remote from the mica-schist and limestone, and thus exhibits an intermediate character corresponding with its inter- mediate position. This stratification in portions of the norite is also distinct a mile to the eastward of this locality on the same side of the limestone, at the point mentioned on page 59. The granitoid and gneissoid quartzite of Peekskill looks much like true granite and gneiss; but its transition to bedded quartzite shows what it in fact is; and this is confirmed by the examination of thin slices, the quartz in it proving to consist of an aggregation of grains just like a sandstone. (The transition of this granitoid quartzite to Massive Crystalline Rocks. 167 schist or slate has been mentioned on page 24, vol. xx. Am. Jour. Sci.) These facts are all in favour of the conclusion that the norite was once a stratum conformable to the Peekskill limestone areas. (3) Vicinity of the Verplanck Limestone belt. —The Verplanck limestone belt follows the border of the river from a point just north of the foot of Broadway, and has the usual strike for the county, north-eastward. Like the Cruger limestone area, it has, on the landward side, with a small exception, a border of ordinary mica- schist or micaceous gneiss, a fine-grained arenaceous rock, the fel- spar of which is mostly orthoclase. This schist extends to the point marked d on the map: at ¢ the rock is massive norite, but no junc- tion of these two rocks is here in sight. The exception referred to is at the south-west extremity of the belt on the river. Here there lies against the eastern side of the limestone a great mass of greyish or brownish-black rock of the Cortland series. It is mostly pyroxenite, moderately coarse in grain, but varies to a kind in which the augite individuals are half an inch broad, and, on the other hand, to a fine-grained variety ; and it con- tains, besides augite, a little hornblende, quartz, calcite, and apatite. But portions of the mass consist of coarsish hornblendite; and a small part of micaceous augite-norite; and there are also broad and narrow bands of very fine-grained black hornblendic mica-schist, not showing well a schistose structure, part of which are conformable in strike and dip with the beds of the limestone, while others are in other positions. All the material is very pyrrhotitic. Besides, it contains the remarkable limestone breccia, of which a portion three feet square is represented on p. 111. This singularly-constituted mass shows no appearance that looks like a subdivision into dykes or veins, except in the bands of horn- blendic mica-schist ; one of these bands has a border of the mica- ceous augite-norite just mentioned. In the limestone just north of this mass, facing the river, occur the supposed dykes or veins mentioned on page 111. Some of them consist of pyroxenite ; others of coarsish hornblendite ; very fine-grained hornblendic rock looking like hornblende schist (Ae) ; very fine-grained hornblendic mica-schist ; augite-norite. As already admitted, there is here abundant evidence of a former plastic state in at least part of this augitic and hornblendic material. Still, there are strong reasons for questioning the idea of its deep- seated origin. 1. The variety in the constitution of the mass border- ing the limestone and in the supposed dykes or veins is very unlike what is ordinarily found in regions of igneous eruption. 2. The supposed veins or dykes are for the most part conformable with the bedding of the limestone, and partake in its flexures, just as if they had been originally beds alternating with the limestone depositions. 8. The impregnation of the limestone along the junctions with pyroxenic or hornblendic material, sometimes minute crystals, looks as if it may have been in part at least a result of mixture attending original deposition. Further (4), there is the decisive fact that these intercalated masses 168 Prof. J. D. Dana—Metamorphism of are represented to the northward by bands ten feet and less to over thirty feet in thickness, of a black fine-grained mica-schist, very pyrzitiferous. Going from the Point, the first outcrops of interstrati- fied schist and limestone occur after an earthy interval of 300 yards, and here the mica-schist is hornblendic, a feature it loses to the north- ward. These beds of mica-schist have just the positions of most of the supposed “veins,” and appear to be their more northern portions ; and further, among the more northern “veins” of the Verplanck shore, some are simply mica-schist. Such facts explain also many of the vein-like bands of Montrose and Stony Points. The difference in mineral constitution between such interstratified beds to the north- ward and on the shore is what should be expected ; for the limestone is bordered to the eastward in the one case by true mica-schist, and, in the other, by augitic or hornblendic beds; and the associations at Montrose and Stony Points are similar. This view is also sustained by the occurrence in the limestone near the schist, 1000 yards from the Point, of coarse spots of pyroxene with mica and chlorite, rudely in layers, which must be due to the original: deposition of impurity and metamorphic action. The augitic rock (pyroxenite) on the east of the limestone at the Point outcrops (owing to excavations in the drift) for 200 yards from the shore; but its place beyond this con- tinues covered for three-fourths of a mile, and here the rock is arenaceous mica-schist; the spots of pyroxene are its only representative. The essential continuity of these intercalated beds of mica-schist with the intercalated beds of augitic and hornblendic material alone the coast proves identity of origin, and origin by sedimentation. It indicates also a small change of constitution in the beds as they extend in that direction. The plasticity occasioned in part of the latter, during the progress of the metamorphism, accounts for all that looks like eruptive phenomena, even to the broken felspar grains found in a slice of the pyroxenite of one of the so-called veins. There is nowhere evidence of injection into or through cold rocks. (4) Vicinity of the smaller limestone areas of the Verplanck Peninsula. —Six small limestone areas occur in the Verplanck peninsula. They are lettered on the map 1 to 5 and yj. Number 3 has the strike of the large Verplanck belt, and has about it the same arenaceous mica- schist. The others are in the midst of, or adjoin, the norite, diorite, and chrysolitic rocks, and hence might be put down among the “inclusions” of the region. In addition, they have a north-west strike (N. 17°—40° W.). But this is the strike, in part of Cruger’s limestone area, and in a portion of the Verplanck belt, so that the twist is not confined to them. And, among so extensive masses of rock that became plastic or fused in the era of upturning, this abnormal position of included strata is not strange. Numbers 2 and 5 are probably parts of the belt; and numbers 1 and 4 may be in the same line, though disconnected by intervening rocks. The following are some of the stratigraphical facts observed among them. No. 4, at Centerville, has at middle on its east side the compact porphyritic mica rock, Cb, which is schistose directly adjoining the Massive Crystalline Rocks. 169 limestone in the field west of the road, and has the strike of the lime- stone N. 47° W. But to the westward in the field (in which the limestone can be traced for 250 yards with a change of strike to N. 62° W.) the mica rock changes to hornblendite and quartz-diorite ; and to the south-eastward along the road, augite-norite appears within a few feet of the limestone, both the felspathic fine-grained (almost cryptocrystalline) variety (Bc), and the coarser dark variety. Whether this latter change in the bordering rock is due to a fault or not, could not be ascertained ; it was not due to an intrusive dyke. No. 5 outcrops on the railroad at 5 (see map) and on two roads at 5/ and 5”, with the strike N. 32° W. Between Montrose Station and this limestone at 5/’, the rock is norite, excepting some greyish augitic rock (Bc) at the corner (Munger’s), where the road turns west, and an outcrop of chrysolitic norite (hypersthene rock) 135 yards west of Munger’s. Highty yards beyond the chrysolitic rock comes the outcrop of limestone. One hundred and fifty yards west of the small exposure of limestone on the north side of the road, a ledge commences which extends along for nearly 850 feet, with no dyke-like subdivisions. It consists mainly of norite, but with some hornblendite and norite-gneiss, and has distinct planes of bedding in several places, all of which are conformable to one another. ‘The strike of its beds is N. 27° W., or nearly that of the limestone, and the dip 60° to 70° H. Part of the norite is garnetiferous. Figures 18, 19 represent the stratification observed in the ledge—Fig. 18 the eastern portion, and 19 the western; forty feet of earthy interval separates the two. At the east end, at a, the rock (as a slice shows) is hornblendite (with about equal proportions of orthoclase and triclinic felspar), and it is schistose. It passes at the place to coarsish quartz-diorite. At 6, it is well-defined micaceous gneiss or norite-eneiss, affording perfect observations of the strike and dip. West of this the rock is mainly norite and augite-norite. At c, for eight feet, black bands (or beds less felspathic than the rest) alternate with the ordinary grey-black rock, and exemplify the con- formability stated, though without divisional planes; at d, are divisional planes in the grey-black augite-norite, having the strike N. 27° W. and dip 70° H. At e, is a much decomposed micaceous gneissic layer (norite-gneiss apparently) conformable in strike, but varying in dip from 40° E. to 60° K.; at f, a distinct bed of light- coloured very felspathic augite-norite, deeply decomposed, having the conformability ; at g, or the west end, the rock is again mica- 170 Prof. Dana—WMetamorphism of Massive Crystalline Rocks. ceous and gneissic, with some garnets, the bedding distinct, and N. 27° W. in strike as at the east end. This ledge, although made up mainly of massive norite and augite- norite, bears thus positive evidence of its having once had bedding throughout, and affords thereby a demonstration that its norite is of metamorphic origin, and that the associated beds comprised also the limestone of the region. (5) A bed of quartzite in norite——About half a mile east of the limestone number 5, about the Montrose Station, the rock is the ordinary dark-coloured norite. 120 yards up the road going north- eastward from the station, a bed of whitish granitoid quartzite outcrops on the roadside for seventy yards, first on the west and then on the east side. This bed of quartzite overlies norite. The norite near the quartzite is micaceous, quartzose and schistose, and that underneath is of the ordinary massive kind. There is evidence also that the bed of quartzite has norite above as well as below it. The quartzite looks somewhat like a pale quartzose porphyritic granite; but, as observed in thin slices, the quartz consists of aggregated grains like sandstone ; showing a resemblance to the Peekskill quartzite. The felspar is mainly orthoclase. C. ConcLusions AS TO THE CorTLAND Rocks. Many more observed facts might be here reported. But the above appear to be sufficient to settle the question as to the relations of the rocks of the Cortland series. They appear to sustain fully the following conclusions :— (1) These rocks, although they include soda-granite, norite, augite-norite, diorite, hornblendite, pyroxenite, and _ chrysolitic kinds, are not independent igneous rocks erupted from great depths. (2) However complete their former state of fusion or plasticity may have in some cases been, they are metamorphic in origin. (3) The strata that underwent the metamorphism were one in series and conformability with the adjoining schists and limestone, and were part of the Westchester limestone series. (‘They are younger rocks if of different age, since they contain and intersect portions of the Verplanck limestone.) (4) These Cortland rocks differ from the other Westchester County rocks because the metamorphic process had to do with sedimentary beds that differed in constitution or were in some respects under different conditions from those that existed elsewhere. On the view reached, it follows that the limestones, schists, and other rocks of the Cortland region originally constituted together one series of horizontal strata. ‘They underwent an upturning through subterranean movements, and in the course of it, they became metamorphosed ; part into mica-schist and gneiss, part by loss of bedding, into the massive rocks. The number of these rocks does not imply widely different ingredients in the original strata. For hornblendite and pyroxenite have the same chemical constitution ; the chrysolitic rocks contain no ingredient not in them also, and are peculiar mainly in their less proportion of silica. Moreover, the W. H. Herries—On the Bagshot Beds. Wal diorite, norite, and augite-norite are alike in containing the same bases in nearly the same proportions. The soda-granite differs in chemical constituents only through its mica, which indicates the presence of potash; but the other rocks also are often micaceous and contain in addition more or less orthoclase. Silica, alumina, iron protoxide, magnesia, lime, soda, potash, are all the essential ingredients obtained in analyses of these various rocks (excluding the magnetite, apatite, pyrrhotite, and pyrite); and it is not mysterious, therefore, that such rocks should be among the results of metamorphism. The geologist will nowhere on the continent find a more instructive spot for a day’s walk than in the western portion of the Cortland region. Starting from Cruger’s Station (37 miles from New York City), a walk of half a mile brings him to the western brick-yard shed ; going north from here by a wood road carries him along section 3, and in less than a mile in a northerly direction (passing brick-yards at the end of it) he will reach Montrose Point and the chrysolitic rocks; following these around by the shore for about a mile he will then pass a brick-yard on the Point, and beyond it find the norites and chrysolite rocks together; a mile and a half more (passing on the route the large Verplanck ice-house) will take him to Broadway, in the village of Verplanck, near the foot of which street,on the shore, occur the limestone and its associated augitic and hornblendic rocks. Thus, in a distance of seven miles, he will see a wonderful diversity of rocks and facts. Possibly he may be convinced, at the end of the walk, that igneous eruption explains everything. But let him go over this ground a second time more carefully, then trace the rocks of Verplanck Point north-eastward, and afterward extend his walks in other directions over the Cortland region, and he may see enough to satisfy himself finally that, although there has been fusion and some eruption, it was not eruption from the earth’s deeper recesses, like that which brought up trap (dolerite) through a series of great fissures for a thousand miles along the Eastern Atlantic border, from the Carolinas to Nova Scotia, all of it rock of one kind essentially, but eruption from less depths, not greater than the lower limits of a series of formations that were subjected together to fold- ings, fractures, and metamorphic change, and mostly far short of this. IV.—Woopwarpran Laporatory Nores.! Part II].—Tse Bacsnor Beps oF tHE Bagsuor District. By W. H. Herries, B.A. Cantab. HE district to which the following notes refer is that which lies E between Bagshot, Woking, Aldershot, Farnborough and Ascot. It consists mainly of heath-land, and seems but little known to geologists; in fact, the only authority for the beds included in this area is Professor Prestwich, who, in his paper on the Bagshot Beds [Q.J.G.S. vol. ii. (1847), p. 278], has supplied all the information about the district that is at present known, He divided the beds 1 Continued from Decade II. Vol. VII. 1880, p. 458. 172 W. H, Herries—On the Bagshot Beds. into an Upper Sandy series, a Middle Clayey series, and a Lower Sandy series. The Middle series he grouped with the Bracklesham of the Hampshire basin. The Upper he placed between the Brackle- sham and Barton; our present object is to show that it is more nearly related to the latter. Upper Bagshot.—This is best exposed in the Foxhills and in Frimley ridges. The series consists entirely of white and yellow sands, with no pebble-beds, by which it is distinguished from the Lower Bagshot sands. Professor Prestwich has recorded a few casts of shells and other obscure remains, chiefly from the cutting through the ridge on the South Western main-line near Frimley Green. JI have been so fortunate as to discover a better locality, and have been able to add considerably to his list. This place is the cutting on each side of the tunnel through the ridge in the new Line from Brookwood through North Camp and Aldershot to Farnham. This cutting, which is not marked on the Ordnance Maps, lies between the words “ Pirbright Common” and “ Mitchet Lake.” The section shows nothing remarkable, and is entirely in the Upper Bagshot. It consists of loose yellow sands, with one or two whiter and rather harder bands, capped by drift gravel. The fossils occur either loose in the sand, or imbedded in small irony concretions, which lie scattered all through the bed. From this cutting, and from the refuse heaps on the side, I have been able to secure a fair collection of fossils, though nearly all unfortunately are in the state of irony casts. This renders specific identification difficult, but Mr. Tawney and Mr. H. Keeping, of the Woodwardian Museum, Cambridge, have kindly identified for me the following. The abundance or paucity of their occurrence is indicated by letters, while it is indicated within brackets whether the form occurs at Barton or Bracklesham, or both. y.c. Dentalium, sp. (like a large un- Ostrea, sp. described Brook species). Pecten triginta-radiatus 2? (Bk. c. Solarium bistriatwm ? (L. Kocene). only). canaliculatum P c. Phorus, two species. carinatus ? (Barton). . Cardita suleata ? (Barton). Qa oO o | Littorina, sp. | Natica labellata ? (both). ambulacrum (both). patula (both). Nucula similis. ¢, [Corbula ficus t (Barton only). ; { pisum (both). striata (both). sp. like NV. conoides (Bk. c. Tellina scalaroides (Brook only ?). only). sp. v.c. Turritella imbricataria (both). e. Crassatella suleata ? (Barton only). sp. or Niso ? c. Cytherea, more than one species. = Rostellaria rimosa (both). Fusus, sp., perhaps young of F. longevus (both). Voluta, sp. Cancellaria, sp. Terebellum, sp. Volvaria acutiuscula (Barton only). Bulla attenuata (both). s Pp. yv.c. Ostrea flabellula (both). A consideration of the above list tends to show a position rather Cardium turgidum ? sp. Protocardium, sp. Lucina mitis (both). Rigaultiana (Barton only). Clavagella coronata (Barton only). Many casts of bivalves indetermin- able. r. Serpulorbis Marshii (both). Wood. a W. H. Herries—On the Bagshot Beds. 173 above the Bracklesham, and seems to assign to the Upper Bagshot of the London basin a position almost equivalent to the Barton of the Hampshire basin. It would also indicate that that part at least of the Hampshire basin Upper Bagshot which, at its summit immediately under the freshwater Lower Headon at Hordwell, contains Oliva Branderi and C. (Vicarya) concavum, is a distinct and probably higher horizon. There are many exposures of the Upper Bagshot in the ridges, but at only three others have I found fossils, and these fossils are not to be compared in state of preservation with those in the Tunnel Hill cuttings. These places are the old cutting on the main line where Prof. Prestwich found his specimens (loc. cit. p. 393) ; a new cutting at Crawley Hill in the new railway from Frimley to Ascot, and a road cutting on the side of the hill near Heatherside nursery gardens. It is remarkable that the fossils should be so com- paratively well preserved only in one place, while in the others they are usually friable pseudomorphs of iron sand, often hollow, and only having the general shape of the fossils they represent, no markings being preserved. Middle Bagshot.—On good fossil evidence this was referred by Prof. Prestwich to the Bracklesham, and sections were given by him in the paper referred to above of the chief fossil localities, viz. Golds- worthy Hill and Chobham Place. Strange to say, at the former of these places I have not been successful in finding any fossils, though I have carefully searched as much of the cutting as is still exposed, it being now much overgrown. A fine section is, however, now open in the new line between Frimley and Ascot, about a mile from Ascot station. The beds shown are in descending order. Wppembacshot rls Yellowssands Pee es ccm en«c sch ic ae ates see feet inches. (elon bandey ys riiesishersrck-icieelaetel «eh.) SAPS FOCr as Ol IeMelllowasan dsl esi ant pparrtayirs git: rwet ack iecats 4% 6 | Pebble-bed often in a greenish matrix ........ 0 10 Middle Bagshot ~ Yellow, white, red, laminated sandy clays.... 10 0 about eed blesbedys zWar. atecateisieccscetntanne stun ever se 0 2 | Yellow and liver-coloured laminated sands .... 3 0 ( Green sand, fossiliferous yellow sand ........ 12 0 about Lower Bagshot Yellow sand. In the Greensand bed fossils occur in a particular band. The following have been found here :— Phorus, sp. c. LPecten corneus. v.c. Natica, sp. v.c. Corbula gallica. Fusus longevus. v.c. Cardita planicosta. Turritella, sp. acuticosta. Voluta, sp. c. Cytherea obliqua ? v.c. Ostrea flabellula. Cardium semigranulatum. sp. porulosum. The fossils are invariably casts and often curiously distorted. In this section the pebble-beds are very thin, but towards the east they swell out. In a shallow road cutting near the Queen’s Clump, about half a mile west of Long Cross, the fossiliferous greensand again appears, and is there capped by about six feet of pebbles. Near Ottershaw the pebble-beds must be ten feet or more, and are always 174 G. W. Lamplugh—The Shell-bed at Speeton. in the greensand. The pebbles are mostly flint, but I have found a quartz pebble. The fossils, it should be noted, are always in the greensand ; fossil localities are, the railway cutting described above, the road cutting near Long Cross, a ditch cutting in the road near Fellow End, cuttings 8. and W. of Chobham Place, and at Knowle Hill; all these places lying north of the Upper Bagshot ridge. Prof. Prestwich mentions besides Goldsworthy Hill near Woking, and the cutting at Shapely Heath near Winchfield, but at neither of these places have I been successful in finding fossils. Lower Bagshot.—One of the best exposures of these beds in this district is at St. Anne’s Hill near Chertsey. The upper part of this hill is one large pebble-bed, the lower consists of light-coloured sands with thinner pebble-beds. A large sand pit has been opened on the north side. In the refuse heaps of this pit I noticed some large blocks of white sandstone exactly like the Sarsen stones found in the drift gravel. I did not see any in situ in the pit, but the workmen told me that they occurred irregularly in the sand, and they seemed to be merely consolidated portions of the sand itself. Some of the pebble-beds are likewise solidified and form hard conglomerates. This is the only instance of stone resembling Sarsen stone that I have seen in the Bagshot beds. Professor Prestwich states that Sarsen stones occur in the Upper Bagshot just below the drift gravel : with this however I cannot altogether agree; for though I have examined many Upper Bagshot pits, I have never seen a Sarsen stone in the Upper Bagshot beds themselves; it is true I have seen hundreds in the overlying drift gravel. The pebble-beds of the Lower Bagshot are chiefly flint, though sometimes pieces of ironstone are found, probably from the Lower Greensand. I have found no fossils in the Lower Bagshot except vegetable remains, which are generally obscure. A bed in a pit near Golds- worthy Hill, consisting of light-coloured sandy foliated clays, lying just above the Lower Bagshot Sands, is full of stalk-like impressions. In the Sarsen stones carbonaceous pipes are often common. V.—On a SHELL-BED aT THE Base or THE Drirr at SPEETON NEAR FInEy, ON THE YORKSHIRE Coast. By G. W. Lampiueu. Introduction—A few miles north-west of Flambro Head the Chalk, after grandly edging the sea with sheer cliffs of over 400 feet, recedes inland ; its steep high scarp making at first an angle of about 20° with the coast. Between these Chalk Wolds and the Oolitic range opposite is the broad flat Vale of Pickering, which is based on soft clays and shales belonging to the Neocomian and Kimmeridge series, deeply covered with glacial and modern alluvial deposits. Where inter- sected by the sea, the Vale has a width of about four miles, but expands inland into a broad plain; to contract again beyond Malton into a mere cutting, by which the Derwent has forced its way through the Oolitic hills into the plain of York. At its eastern G. W. Lamplugh—The Shell-bed at Speeton. 175 end the glacial deposits are of great thickness, but slope away inland, and are soon overlaid by the low-lying modern peats and silts ; and it is this drift barrier alone which prevents the Derwent from now flowing directly into the North Sea; as it would seem to to have done in Pre-Glacial times. The little village of Speeton is perched on the edge of the chalk- scarp just after it has left the coast; and below it are the sections which have already made the name familiar to geologists. On its right, at the base of the high cliffs, is the well-known outcrop of Red Chalk, nowhere so well seen; whilst the low cliffs immediately below the village consist chiefly of that mass of clays and shales whose slipped and intricate sections have been so ably deciphered by Professor Judd,' who has found in them representatives of the Neocomian, Portlandian, and Kimmeridge ages. Nor is the interest of these cliffs even now quite exhausted, for, though as yet little noticed, at first overlying but soon overlapping and hid by the Secondary clays, are some of the finest and most complete drift sections of a coast famous for its drift sections; and, at the base of the drift, is a bed of sand with shells; to which I would now draw attention. Description of the bed.—The first, and, so far as I am aware, the only previous notice of this bed, is contained in the 8rd edition of Prof. Phillips’s “‘ Geology of Yorkshire, Part I.,” where he gives the following brief account of it (p. 100), which will serve to describe its position :—‘“ Whilst searching these (i.e. the Neocomian) cliffs in the autumn of 1855, I discovered a considerable bed of shelly sand under or in the lower part of the drift at a considerable height above the shore, and took measures and bearings to recover the spot. The shells then found were all Dimyaria (Cardia, Telling, Amphidesma Listeri, Mactre and Psammobia), shells of a sandy shore; they were often found with valves united. Only living species were found, unless a very large Cardium, much resembling C. Parkinsoni of the Crag, were really of that species. This shell-bed, re-examined in 1872 by Mr. J. E. Lee and myself, yielded the same shells, with a portion of Cyprina islandica® and a Littorina with colour bands preserved. “The situation is nearly over the contorted pebble-beds, at a height of 105 feet from the shore, the drift rising here to 160 feet. The shelly sands are seen to be covered by a clay-drift with chalk 1 Quart. Journ. Geol. Soc. vol. xxiv. p. 218. 2 | think it doubtful whether this was really obtained from the shelly sands, but had not rather been washed on to their surface from the overlying Boulder-clay ; for it is hardly likely that a fragment of so strong a shell as C. islandica should be found, when such comparatively delicate shells as Scrodicularia piperata have been deposited unbroken ; for though these shells are now almost always found so crushed as to make it difficult to recognize them, this has been done after they were buried, for the fragments always remain together and are in no wise rolled. Most careful search, also, has failed to reveal to me another particle, whereas worn frag- ments of this shell are rather abundant in the clay above, which is constantly washing down and masking the sand bed. As Prof. Phillips considered the bed of Drift-age, he would not consider this of much import. 176 G. W. Lamplugh—The Shell-bed at Speeton. fragments in unusual abundance ! immediately over the sands. These are 10 feet thick ;* they are traced downwards to within 8 feet of the Kimmeridge Clay; but this junction has not been actually seen, and it is supposed that a small band of drift-clay may underlie the shells. Itis obviously a portion of the old sea-bed, and may be compared to the so-called Crag at Bridlington and the shell-bed found by Sir C. Lyell at the base of Dimlington Cliff. (Here follows a rough sketch of the bed.) “ About forty years since, Mr. Bean showed me some of these shells, and I was struck by the resemblance to Crag, both of the shells and the yellow sandy matrix; but my friend, supposing them to have been collected by birds,’ did not inform me of the locality, and appears not to have made further research. This is, I believe, the only notice which has been published, though soon after my examination in 1855 acommunication on the subject was made to the Ashmolean Society at Oxford. Though, as I believe, only one bed of these shells occurs, the slipping of the cliffs has made a kind of double escarpment, so that when first seen in 1855, there was a large exposure; and but for other occupations, measures would have been taken to excavate largely, and obtain a more complete descrip- tion of the deposit.” To those acquainted with these cliffs or with Prof. Judd’s paper on the “Speeton Clay,” it may assist the above account of the position of the bed, as the contorted pebble beds (Portlandian) are never now seen, to add that this exposure is on the ridge which divides ‘“‘ Middle Cliff” from ‘New Closes Cliff,” on which, when seen in profile, the slip mentioned by Prof. Phillips makes a well- marked terrace. - When I first examined it two years ago, I soon saw that there was a much better exposure than in Prof. Phillips’ time, the slip which causes it having gradually sunk to a lower level, thus baring a greater thickness of the sand, which is also seen to change its character in its lower part, and to contain three or four species of shells which are absent from the upper part of the bed. In fact, so low had the terrace sunk, that I was able with the help of a spade to demonstrate the non-existence of the supposed underlying band of Boulder-clay. At the time of writing the slip shows signs of a general break-up; so that, unless a fresh mass come down from above, we may hope shortly to have a perfectly clear section down to the Neocomian. / 1 This was probably really the chalky gravel presently to be described as capping the bed, with a masking of Boulder-clay. 2 J found them to be 14 feet. 3 A source of much trouble in collecting from the drifts on the coast; for the sea- birds carry molluscs into the clifis to break and eat, and the fragments get washed into the clays and gravels. 4 Any one’ looking for this bed might find it difficult to hit upon, owing to the before-mentioned masking by Boulder-clay washed from above, so that it exactly resembles Boulder-clay itself. Until its position was pointed out tome by F. A. Bedwell, Esq., of this town, who had re-discovered it, 1 was unable to find it from this reason. G. W. Lamplugh—The Shell-bed at Speeton. Lik Instead of Boulder-clay, I found a slight thickness of gravel of a purely local character to underlie the shelly sands, consisting entirely, as far as I could see, of much stained Red and White Chalk pebbles, Neocomian nodules, plates of Upper Kimmeridge shale, with many fragments of fossils, chiefly Belemnites, not much rolled, from the Red Chalk and Neocomian, and an occasional Oolitic pebble. I have also found in the bed itself a pebble of jet from the Upper Lias. This gravel rested directly on the lower part of the Lower Neoco- mian, the Astierianus band of Prof. Judd, containing Belemnites lateralis and Exogyra sinuata in abundance ; and not on Kimmeridge Clay. The section from the cliff-top to the Neocomians then stood as follows :— Curr Top. If the top red clay be traced north- ward, it is found to separate into two well- marked divisions, the upper of which is Rediifisih Bawidmdley red and the lower brown, with gravels 30 feet. and sands, sometimes of great thickness, between them. Here, however, they are mingled, and no line can be seen. The Boulder-clays, except the top red clay, contain shell fragments sparingly scat- Sand and Gravel, 5 feet. Dark Boulder-clay, tered through their mass, which differ 10 feet. widely, however, from those contained in ———————_—_——_— Ss the bed below; Dentalium, two or three Sandy Shell bed, species of Astarte, Cyprina, Mya, Saai- With ne 2 Hee aboveand| ¢#¥4; ete., occurring amongst others, and Walow: of course the ubiquitous Tellina Balthica, Penn EEE EEE Ee Ee eee teeeteeeees which never fails a Yorkshire Post-Ter- Lower Neocomian. tiary shell-list. The shell-bed itself is made up as follows :— Thickness. ft. ins. Fine chalky gravel a 200 500 6 Dark clayey sand ; few shells. Soft yellow sand with indu- rated lumps: many shells, Cardiwm edule, T. Balthica, Scrobicularia piperata; passing into ) & Dark blue-black muddy sand, with a foetid odour: with a few pebbles and plates of Kimmeridge shale: many shells —T. Balthica, C. edule, Utriculus obtusus, Hydrobiaulve, plentiful; Littorina littorea and L. rudis, rare; at the very bottom—Mytilus edulis 5 1 Gravel of Red and White Chalk, “broken “Neocomian fossils, etc. ra ae sco!) Blowin 11 16 3 The shells are in so bad a state of preservation that it is very difficult to remove them. More especially is this the case in the upper part of the bed, where the water which oozes out from the soaked sand below percolates more freely. DECADE II.—VOL. VIII.—NO. IV. 12 178 G. W. Lamplugh—The Shell-bed at Speeton. The following species have been obtained : 1 Tellina Balthiea. Mytilus edulis. Psammobia sp. (fide Phillips). Littorina littorea. Mactra sp. (Gas Sane », rudis, var. . Scrobicularia piperata. Hydrobia ulve. Cardium edule. Utriculus obtusus, var. pretenwis. As noticed by Prof. Phillips, the bivalves generally occur with valves united; but they are not often in the attitude of life; usually having the umbos upwards, and with the valves gaping open. Single shells do occur, and also an occasional imperfect valve; but, on the whole, they show very few signs of wave action, and appear to have been left by quietly receding tide-waters on a muddy flat. Another proof of the quietness of the waters is the sharply-fractured and unabraded state of the broken Belemnites, which, with a few other pebbles, are sparsely scattered through the lower part of the sands. That the bed accumulated slowly is shown by the difference in fauna and lithological character between the upper and lower parts of the deposit; the result of some slight and gradual change in the surrounding conditions, probably a slight deepening of the water with an accelerated current. The shells confirm the idea strongly suggested by the shape of the ground that the beds were formed at the mouth of a quiet tidal estuary. When the waters of the sea stood at the level indicated, the glacial and later beds which now cumber the Vale being then unformed, what is now the Vale of Pickering would then be a wide, shallow, land-locked estuary receiving the copious drainage of the Hastern Moorlands, which now flows through the narrow gorge at Castle Howard to join the Ouse. The piece of light jet found in the deposit tells of distant erosion in the Upper Lias, having doubtless been brought down by the old river from the higher reaches of the valley, north of Pickering. Unfortunately the above limited shell-list yields us little evidence as to the age of the bed. Tellina Balthica, however, shows that it cannot be so old as the Red Crag; and as it will be shown to underlie the oldest Yorkshire Glacial deposit, its age must lie somewhere between then and early Glacial times. Tis Extent and Stratigraphical Relations.—By far the clearest and best exposure of these shelly sands is the one described above, on the dividing ridge between “ Middle ”’ and ‘‘ New Closes Cliff,” about half a mile north of Speeton Gap (where the Chalk ends). On the south side of this ridge they end abruptly, having been carried away by a huge slip, and portions of them may sometimes be seen down at the level of high-tide; but beyond this, though I have carefully sought over the slipped ground up to the foot of the chalk scarp, I have not been able to find any traces of them. The accompanying chalk-gravel, rapidly increasing in thickness and in roughness as we approach its parent-slope, can be followed through- : 1 IT have to thank Dr. Gwyn Jeffreys for his kindness in examining these shells or me. G. W. Lamplugh—The Shell-bed at Speeton. 179 out, but without further signs of shelly sand, which probably ‘therefore thins out as the Neocomian clays rise to a higher level, and we approach the high-water mark of the old estuary. It is, indeed, tolerably certain, that in this exposure the beds have reached their greatest development, for northward from this point the underlying Secondary clays show a steep denudation slope, which reaches the beach at the north end of New Closes Cliff; so that if all the drift were removed, a broad flat terrace of Neocomian clays, coinciding perhaps with the tidal flat of the old estuary, would stretch along under the chalk-scarp. And, as might be expected, it is on the crest of this terrace that the sands are thickest, for in the deeper central portions of the valley the current from the land would probably run too strongly to allow sand-banks to form. I have found traces of the sands here and there amongst the slips across New Closes Cliff, following the denudation slope of the Secondaries till they reach the beach- ‘line, where the sands may be seen at the cliff-foot when the sand and shingle of the beach happen to be removed from the base of the cliff. The distinction between upper and lower parts still holds, but the sands are only about two feet thick, and shells are not at all plentiful. Northward beyond this they may be seen at intervals between slips, being often little better than a re-arranged form of the Speeton clay, till “The Gill” is reached, where they finally disappear from the cliff-foot. In May, 1879, however, there was a very interesting exposure on the beach, nearly opposite the village of Reighton, about a mile north of “The Gill,” and here again T obtained traces of the deposit, and alsu had direct evidence as to its being older than any Yorkshire Boulder-clay. As has been shown, in the chief exposure, in New Closes Cliff, the shelly sands are overlaid by a dark Boulder-clay, above which a red Boulder-clay is seen—a parting of gravels occurring between them. I have also mentioned that, if the upper clay be traced northward, it is found to consist really of two separate clays, the division here having been obliterated. The top clay’ I believe to be the northward extension of the ‘‘ Hessle Clay” of Holderness. The other two form the “Purple Clay” of Messrs. Wood and Rome,? but I have also endeavoured to show* them to be really distinct, and as good divisions as any of those now recognized, and which may be readily traced wherever the “ Purple Clay ” is well developed, either north or south of Flambro. ‘The shell-bed is therefore overlaid here by what we may call the “‘Lower Purple Clay.” The exposure on the beach, however, revealed older divisions. It extended nearly 500 yards, and had a varying width of about 30 yards. In it the following beds were seen, appearing to dip slightly towards the cliff :— ' Proce. Yorkshire Geol. Soc. for 1879 (On the Divisions of the Glacial Beds in Filey Bay). 2 Quart. Journ. Geol. Soc. vol. xxiy. p. 147. 3 VY. supra. 180 G. W. Lamplugh— The Shell-bed at Speeton. Commencing from the high-water side we first crossed over— 1. Boulder-clay, belonging to the ‘‘ Lower Purple,’’ which is continued into the cliff. 2. Bluish Boulder- -clay, with many shell fragments, and with streaks of fine blue mud containing many crushed shells. Fauna that of the Bridlington glacial shell-bed. This was undoubtedly the ‘‘ Basement-clay’’ of Messrs. Wood and Rome. 3. Brown Boulder-clay, full of stones; no shells. (Not yet seen elsewhere on the coast, the bottom of the Basement-clay being rarely visible.) . Band of fine Chalk-gravel, with a seam of sand. . Thin band of re-arranged Kimmeridge shale, with broken fossils. . Highly contorted Upper Kimmeridge shale, Here it is tolerably certain that the sandy beds are represented by the few inches of dark muddy sand in the fine chalk rubble (No. 4), for we have already seen how rapidly they thinned after leaving the edge of the old hollow, probably owing, as before suggested, to the strength of the current in the middle of the valley. I did not see any shells; but as all those found in the chief exposure were shore species, and this exposure but small, this did not surprise me. No. 38 seems to be the remains of an older clay than any before noticed in Yorkshire, but I know of no other case in which the bottom of the “Basement-clay ” presents itself for investigation. It may well be the result of a land-glaciation preceding the flow which formed the overlying shelly blue clay, which appears to have come in main from seaward. There is thus a curious unconformity in the beds overlying the shell-bed whose preservation is a remarkable instance of the irregu- larity of glacial denudation. Age of the Deposit.—As the so-called ‘‘ Basement-clay ” is now believed, and probably rightly, to be of the age of the Cromer Tills, it follows that the bed of shells at Speeton is older than that deposit. May it not then, on good evidence, be correlated with some part of the marine Pre-Glacial beds of Norfolk ? Beds of similar Age in the Neighbourhood.—There is, almost con- tinuously, on the top of the Chalk from its first appearance, north of Bridlington, to Flambro, a band of fine gravel of varying thickness, consisting wholly of chalk. This gravel sometimes admits sand- streaks, which, at the bottom of the Danes Dyke Valley, a narrow old Pre-Glacial hollow three miles north of Bridlington, and in other places, thicken out into well-bedded sands and sandy silts. These, at Danes Dyke, are seven feet in thickness, and though as yet Il have not found any shells or other remains in them, they are probably of about the same age as the Speeton bed. It is rather curious that at Danes Dyke these sands show the same division into dark blue below and yellow above. Some years ago the remains of some large elephantine animal were found in the cliff about a mile and a half north of Bridlington, and as far as I can learn they appear to have been obtained from the horizon of this bed, but I have not been able to obtain any exact information on this point. Da Prof. T. Rupert Jones—On the Carboniferous System. 181 VI.—Norte on THE CARBONIFEROUS SYSTEM IN BRITAIN. By Prof. T. Rupert Jonzs, F.R.S., F.G.S. i comparing the relative thicknesses of the Welsh-English and the Scotch Carboniferous series for lecture notes. I have found it difficult to obtain from books definite statements on this point as regards some groups of these strata in Scotland. After considerable reading I gather the following information. A general section of the Carboniferous strata of Scotland shows this arrangement ;— Upper Coals. Moor Rock or Roslyn Sandstone. ( Upper Limestones. Carboniferous Limestone Series ’ Lower Coals with Limestones. | Lower Limestones. Calciferous Sandstone Series. In the “Geological Survey Memoir on the Neighbourhood of Edinburgh” Mr. Howell gives the following average thicknesses. for the Mid-Lothian Coal-field (p. 73) :—Coal-measures 1220 feet ; Millstone-grit 340 feet; Carboniferous Limestone series (including Upper Limestones 650’, Edge Coals 600’, Lower Limestones 340’) 1590 feet. The thickness of the Lower Carboniferous strata (Cal- ciferous Sandstone) is not given in Prof. Geikie’s portion of the Memoir, but his description of the series proves it to be of great amount. In the “ East-Lothian Memoir” Prof. Geikie estimates the thick- ness of the Calciferous Sandstone series at 1350 feet, as seen on the coast section between Siccar Point and Thorntonloch.t The thickness of the Carboniferous Limestone series is not mentioned in this Memoir, though the usual arrangement of the Upper and Lower Liniestone groups, with profitable Coal-measures between them, is fully described. tay i In later Memoirs of the Geological Survey of Scotland many details of the local thickness of the subdivisions of the Carboniferous Limestone series and of the Coal-measures are given; but no estimate of the aggregate thickness of the formations is ventured on. The grouping of the strata in the West of Scotland appears to be similar to that of the Hastern side, although the Lower Carboniferous series has not the same facies as that in the Hast. In the useful ‘“‘Catalogue of the Western Scottish Fossils.” published by Members of the Geological Society of Glasgow for the British Association Meeting of 1876, the thicknesses of the different members of the. system, in Central and Western Scotland, are thus stated (pp. 31 and 52) :— Upper Coals and Ironstones ......... . 1500 to 1800 feet. Millstone-grit Series .............44. 480 ,, 900 ,, Carboniferous ( Upper Limestone Series ............ 480 ,, 600 ,, Limestone Lower Coals arid Ironstones ........... 420 ,, 600 ,, Series, Lower Limestone Series..........+.+. 600 ,, 1200 ,, Calciferous Sandstone Series.......... 1500 ,, 1800 ,, 4980 ,, 6900 ,, 1 «Geol. of East Lothian,’’ 1866, p. 30. 182 Prof. T. Rupert Jones—On the Carboniferous System. In Fife the Lower Carboniferous, or Calciferous Sandstone, series appears to be abnormally thick (8900 feet according to Mr. J. W. Kirkby’s paper in the Quart. Journ. Geol. Soc. No. 144, p. 559), compared with the estimate given by Prof. Geikie for the same series in Hast-Lothian. In a letter received from the author of the above paper, it is stated that a general section of the Fifeshire Carboniferous series (which, besides being essentially complete, is of interest on account of its being the most northerly exposure of this formation in Britain) in all probability is nearly as follows :— feet. feet. iy Uippeneedwbcdsaene rier 900 I. Coal-measures ........ 2. Lower Measures with work-\ 4 400 2300 AO COA aoocen0n000¢ IL. Millstone-grit series, or Moor Rock ..............-. ee 300 (1. Upper portion with lme- 400.) i i | Stones 27... 90393089 | III. Carboniferous Lime- g 2. Middle portion with work- 800 1600 stone Series ...... ablercoalsmaseee seca | 3. Lower portion with aa 430 | if RUGMES cosnnpedoegan000 J TY. Calciferous Sandstone! series .........2..220+se005s 5060 4000 . 8200 The English series of Carboniferous strata immediately south of the Border does not apparently differ much from the Scotch. Ina sketch of the Geology of Northumberland, by the late Mr. George Tate (“ Transact. Nat. Hist. Soc. Northumberland and Durham,” 1868, vol. ii. pp. 6—18), the Carboniferous strata are grouped as below :— feet. feet. I. Coal-measures aye Totter pi sialclatepalausvetaralaperencvolsint venrcodersoare 6000 2000 Mie Mallstone= Orit te, teratats muerc ied. ls Ch dois es Cecte minnie teretae etree 58.50 500 1. Calcareous Group, with 1700 | many beds of limestone .. } IIL. Mountain Limestone., 42. Carbonaceous Group, with 2600 | seven workable coals and 900 a few limestones ........ Ys Pucdian Group! eee scales: <2 hee ceeeetonce eae S080 1000 6100 The lowest or Tuedian group of this series consists of “rey, greenish, and lilac shales, thin beds of argillaceous and cherty lime- stones, and a few buff magnesian limestones, and of sandstones and slaty sandstones.” Several of the shales and sandstones also are calcareous. The characteristic fossils are Stigmaria, Lepidodendron, and Sphenopteris; Rhizodus and other Fishes; Molluscs allied to Modiola; Entomostraca; Spirorbis; and occasionally such marine forms as Orthoceras, Murchisonia, and Pleurotomaria. These features are pretty much those of the Calciferous Sandstone on the other side of the Border, with which series of strata Mr. Tate’s group is identical. 1 Basement beds not seen. Reviews—Prestwich’s Index Guide to the Geol. Collections. 183 In comparison with these north-country sections, the Welsh- English series, taken generally, offers :— feet. ( Upper or Ardwick series. Coal-measures.. 10,000 { Middle or Pennant series. | Lower or Gannister series.! Upper Carboniferous. Millstone-grit... 1,000 I; Carbone 1. Up. Limestone-shale or Yoredale series. cite By ne czeus 2. Mountain, Scar, or Great Limestone. 5 : se Carboniferous. Limestone .. 1,500 alt acon Oral iaesten etshales 12,500 Of course, the question as to how far the whole series of the two regions, or members of the series, may be conterminous and con- temporaneous, or merely analogous and homotaxeous, is not regarded in this notice. REVIEWS. ———>>—— An Inpex GUIDE To THE GEOLOGICAL COLLECTIONS IN THE UNIVERSITY Museum, Oxrorp. By Professor Prestwicu, M.A., F.R.S., ete. (Oxford, Clarendon Press, 1881.) INCE the “Notices of Rocks and Fossils in the University Museum,” by the late Prof. Phillips, which has long been out of print, many additions have been made, portions of the collection re-arranged, and a large number of specimens have been carefully named and located, so that a new and thoroughly revised catalogue was essentially requisite, and this has now been supplied by Prof. Prestwich. Without giving too much detail, or troubling the reader with an array of specific names, this guide gives a general account of the arrangement adopted, in which the author has endeavoured to show, besides the position of the specimens in the Museum, their relative place in systematic classification and geological age. The order in which the collections are described is (1) the Rocks and their constituents, and (2) the Organic remains or the Paleonto- logical portion. The former include the chief building and ornamental stones of the British Islands (of which the use in the Museum itself furnishes a good example), as well as notices of other Igneous, Metamorphic, and Sedimentary Rocks; a table showing the succession of the last in the British area is given at p. 21. A brief description of the classification of the minerals concludes this part. The second portion treats of the general paleontological series of the Paleozoic and Secondary strata, and of the Tertiary and Quaternary rocks and fossils (pp. 25-48), together with descrip- tions of the local collections of the typical fossils of the Oxford district (pp. 49-58), as well as of the collections illustrative of the range and variations in time of particular classes of fossils, and to which the diagram at p. 64 is a valuable supplement, as 1 In his memoir ‘‘ On the Classification of the Carboniferous Series’ (Quart. Journ. Geol. Soc. vol. xxxiii. pp. 6138, ete.), Prof. EK. Hull gives his reasons for grouping the Gaunister, Millstone, and Yoredale series as the Middle Carboniferous,”’ 184 _ Reports and Proceedings— showing clearly the order in time of the succession of life on the globe. Both the visitor and student will find this work a concise and handy guide to the rocks and fossils contained in the Museum, which, among many interesting forms, contains the classical specimens collected by Dr. Buckland, and the fine series of Saurian remains obtained by Prof. Phillips and described in his “Geology of Oxford and the Valley of the Thames.” J. M. ISP NISMS aes) JNAND) ISsVOe@saaio say erS- GEOLOGICAL Socirty oF Lonpon. J.—Awnvat Generat Mrerine.—February 18th, 1881.—Robert Htheridge, Ksq., F.R.S., President, in the Chair. The Szcrerarizs read the Reports of the Council and of the Library and Museum Committee for the year 1880, the Council announcing with much satisfaction that the financial depression under which the Society had been suffering during 1878 and 1879 had proved, as was anticipated, only temporary, and that the Society is now in a very prosperous condition. The Council’s Report also announced the publication of the new Catalogue of the Library, which, although considerably larger than was at first expected, will be issued to the Fellows at the price originally fixed for it. The Report further announced the awards of the various Medals and of the proceeds of the Donation Funds in the gift of the Society. In presenting the Wollaston Gold Metal to Prof. P. Martin Duncan, M.B., F.R.S., F.G.8., the Prestpent addressed him as follows :— Professor Duncan,—It is with no ordinary pleasure that the Council have awarded to you the Wollaston Medal, the highest honour that it is in their power to bestow, in recognition of the valuable services which you have rendered during so many years to the advancement of Geology, and especially of Palaontology ; and I may add that it is equally productive of gratification to me that this honour is to be formally conferred upon you by my hands. Since the year 1863 paleontologists have been indebted to you for no fewer than twenty-six memoirs relating to the history, structure, and distribution of the fossil Actinozoa, a group which you have made peculiarly your own by long-continued and most careful researches. Further, you have enriched the publications of the Paleontographical Society with several most important treatises on British Fossil Corals, supplementary or, rather, perhaps, complementary to the classical Monograph of MM. Milne-Kdwards and Haime. These labours alone, and the value of their results, might have justified the Council. in awarding you the Wollaston Medal; but besides your researches upon the Actinozoa, we have to point to several important papers upon the fossil Echinoder- mata, to others relating to subjects of Physical Geology (also freely touched upon in your more special memoirs), and particularly to your exceedingly important work in: connexion with the Geological Survey of India, in describing the fossil corals of that Peninsula, and discussing the questions of both zoological and geological interest which naturally arise out of the study of those organisms. Few, indeed, of our Fellows are in a better position to appreciate your valuable labours than myself ; scarcely a day passes that I have not occasion to consult one or more of your contributions; and the more I consult them the more I am convinced of their value. Patiently and unobtrusively, for nearly twenty years, you have followed out the line of research necessary for the fulfilment of your self-imposed task; you have sacrificed the advantages of professional life to devote your energies to the advance- ment of science; for seven years (from 1864 to 1870) you gave the Society the Geological Society of London. 185 benefit of your services as one of its Honorary Secretaries, and for two years (1876— 1877) you worthily occupied the Presidential Chair. Such considerations as these would not alone, perhaps, have warranted the award of the Council; but the recollection of such services rendered to the Society is hardly out of place, as supplementing those more generally appreciable merits upon which the award was really founded. On all accounts it is with much pleasure that I hand to you the Wollaston Medal. Professor Duncan made a short speech acknowledging the pleasure he felt in receiving the Medal. The Prestpent then presented the Murchison Medal to Prof. ARCHIBALD GEIKIE, F.R.S., F.G.S., and addressed him as follows :— Prof. Grrxre,—If any one Fellow of our Society more than another could be selected to receive the Murchison Medal for his vaiuable contributions to geology, it would be yourself; since no man living has contributed more to the advancement of that science which it is the special object of our Society to cultivate and diffuse. Your labours in the field connected with your duties as Director of the Geological Survey of Scotland, your learned and valuable contributions to the Journal of our Society, the Transactions of the Royal Society of Edinburgh, and the Glasgow Geological Society, and other publications too numerous to mention, eminently qualify you to be the recipient of the Medal founded by your late chief and friend Sir Roderick Murchison. To enumerate your contributions to the literature of the geology of Scotland, or your many important writings connected with our science, would lead me too far—some thirty papers, besides educational works, have resulted from your industry and knowledge. Your able paper alone, on the ‘‘ Old Red Sandstone of Scotland,’’ published in the Transactions of the Royal Society of Edinburgh, would entitle you to the highest consideration of the Society. Able. indeed, are other contributions, especially those ‘‘On the Chronology of the Trap Rocks of Scotland,” ‘‘ On the Date of the last Elevation of Central Scotland’’ (in vol. xvii. of our Journal), ‘‘On the Phenomena of Succession amongst the Silurian Rocks of Scotland’’ (Trans. Glasgow Geol. Soc. vol. iii.), and ‘‘On Earth Sculpture.’’ The, Council believed, too, that it would be gratifymg to you to receive a mark of their esteem and sense of your untiring labours, the Medal founded by one with whom in earlier life you were closely associated, and whose endowed Chair of Geology in the University of Edinburgh you have been the first to fill. en GEIKIE expressed, in reply, his gratification at the gift of the Murchison edal. The Prestpent next handed the Lyell Medal to Mr. Warineton W. Suyrtu, F.R.S., F.G.S., for transmission to Dr. J. W. Dawson, FE.R.S., F.G.S., of Montreal, and addressed him as follows :— Sir Charles Lyell, in founding the Medal that bears his name, intended that it should serve as a mark of honorary distinction, and as an impression on the part of the governing body of the Society of their opinion that the Medallist has deserved well of science. I need hardly say that the Council, in awarding the Lyell Medal to Principal Dawson, have done so with a sincere appreciation of the high value of his truly great labours in the cause of Paleontology and Geology. When I refer to his published papers, I find that they number nearly 120, and that they give the results of most extensive and valuable researches in various departments of geology, but more especially upon the paleontology of the Devonian and Carboniferous formations of Northern America. No fewer than 30 of these papers have appeared in the pages of our own Quarterly Journal. Considering the nature of these numerous con- tributions, the Council would have been fully justified in awarding to Dr. Dawson’ one of its Medals, upon the sole ground of the value of their contents; but these are far from representing the whole of the results of his incessant activity in the pursuit of science. His ‘ Acadian Geology,’ ‘ Post-pliocene Geology of Canada,’ and ‘Fossil Plants of the Devonian and Upper Silurian of Canada,’ are most valuable contributions to our knowledge of North American Geology ; whilst in his ‘ Archaia,’ ‘The Dawn of Life,’ and other more or less popular writings he has appealed, and worthily, to a wider public. We are indebted to his researches for nearly all our knowledge of the fossil flora of the Devonian and other Precarboniferous rocks of America, and of the structure and flora of the Nova-Scotian coal-field ; and finally I must refer especially to his original investigation of the history, nature, and 186 Reports and Proceedings— affinities of Hozoon. These researches are so well known that they have gained for Dr. Dawson a world-wide reputation; and it is as a slight mark of their esteem, and their high appreciation of his labours, that the Council have awarded to him this Medal, which I will request you to forward to him, with some verbal expression of the feeling with which it is oftered. Mr. Warineron W. Smyru then read a letter from Dr. Dawson regretting he was unable personally to be present, and expressing his sense of the honour con- ferred upon him. The Presmpent then handed the Bigsby Medal to Prof. Morrts, F.G.8., for transmission to Dr. Cuaries Barrors, and addressed him as follows :— The Council of this Society has selected Dr. Charles Barrois to be the recipient of the Bigsby Medal, and have awarded it to him for his numerous papers and con- tributions to geological science. Dr. Barrois’s chief or most important work (written in the year 1876, and published at Lille) is ‘Recherches sur le terrain crétacé supérieur de l’ Angleterre et de |’ Irlande,’ a production almost exhaustive in its description of the Cretaceous rocks of England and Ireland, and of the utmost value to tnglish students of geology. Dr. Barrois in this work has been the first to attempt to arrange the English Cretaceous rocks in Paleontological zones, and eminently has he succeeded in defining and correlating the horizons of France and Brita. He is also the author of a ‘Mémoire sur le terrain Crétacé du Bassin d’ Oviedo, Espagne,’ with a paleontological description of the Echinodermata by Gustave Cotteau. His great industry and untiring zeal for geological science entitle him to the consideration of the Council ; and I therefore beg you to forward to him the Bigsby Medal as our recognition of his services, and, according to the wishes of the founder, we look forward to other and equally valuable contributions. Prof. Morris read a note from Dr, Barrois, in reply, to the honour conferred. In handing to Prof. J. W. Jupp, F.R.S., Sec. G.S., the balance of the Wollaston Donation Fund for transmission to Dr. Ramsay H. Traquair, F.G.S., the Prestpen'r said :— In handing to you, to be forwarded to Dr. Traquair, the balance of the proceeds of the Wollaston Donation Fund, I have to request that you will inform him of the feeling of the Council, that it is rarely that they can have the opportunity of awarding this fund to a more able and accomplished naturalist than himself. His long-continued researches upon the Ganoid Fishes of the Carboniferous formation have rendered his name eminent in this department of Paleontology. As an accomplished anatomist and zoologist, we must have every confidence that his treat- ment of these Vertebrates in the memoir which he is contributing to the publications of the Palewontographical Society will be of the most careful and judicious description, whilst the value of this and his other works is vastly enhanced by the beautiful figures with which he illustrates them. Under these circumstances it affords me much pleasure to place in your hands, for transmission to Dr. Traquair, the balance of the Wollaston Fund, which I hope he will receive as some recognition on the part of the Society of the value of his researches, and, at the same time, as a small aid to him in further prosecuting them. Prof. Jupp, in reply, read an appropriate note received from Dr. Traquarr, cordially thanking the Society. The PrEsipENT next presented the balance of the proceeds of the Murchison Donation Fund to Frank Ruriey, Hsq., F.G.S., and addressed him in the following words :— For many years you have devoted your time and attention to the microscopical structure of rocks and rock-forming minerals, a branch of scientific research of the highest importance to the petrologist and geologist ; and now that our attention is being so much drawn to the structure of the metamorphic and igneous rocks, with a view to a better nomenclature and a revision of old and obsolete views, the Council of our Society believed that in your hands good work would still be carried on ; they, therefore, have awarded to you the balance of the Murchison Fund, which I have much pleasure in handing to you in recognition of your past researches, the results of which you have from time to time communicated to the Journal of the Society, Tew are more aware than myself of the interest you take in this branch of study, Geological Society of London. 187 and it affords me much gratification to be the medium of conveying to you the appreciation of the Council and the accompanying fund. Mr. Ruruey suitably returned thanks. In presenting to G. R. Vinu, Esq., one moiety of the balance of the proceeds of the Lyell Donation Fund, the Presipent addressed him as follows :— A moiety of the balance of the proceeds of the Lyell Geological Fund has been awarded to you by the Council of the Geological Society. In making this award the Council were actuated in part by the wish to express their sense of the value of your researches upon the fossil Bryozoa of the Paleozoic rocks, as evinced especially by your published writings on the Diastoporide, an exceedingly difficult group, and in part by their desire to assist you in the further prosecution of your investigations. I have much pleasure in handing to you this small testimony of the appreciation of the Council. Mr. Vinx, in reply, thanked the President for this token of recognition, on the part of the Council, of his labours. The Presipent then handed to Prof. H. G. Sreney, F.R.S., F.G.S., for transmisson to Dr. Anton Frirscon, of Prague, the second moiety of the Lyell Donation Fund, and said :— The Council has awarded a portion of the Lyell Geological Fund to Dr. Anton Fritsch, Professor of Zoology in the University of Prague, in recognition of his valuable contributions to paleontology. Dr. Fritsch is an accomplished zoologist, who has enriched his studies of many groups of fossils, invertebrate and vertebrate, with admirable knowledge of existing lite. Durmg the last thirty years Dr. Fritsch has published about one hundred and twenty memoirs, many of which relate to paleontology and geology. Besides scattered papers on Hozoon, Callianassa, and other subjects connected with the fossil fauna of Bohemia, Dr. Fritsch has also published some standard works monographing the fossils of his native land. These comprise the Cretaceous Cephalopods (1872), the Cretaceous Reptiles and Fish (1878), and his great work on the Fauna of the Permian Rocks (still in progress), of which two volumes, devoted to Amphibia, have been issued. ‘These volumes are excellent examples of descriptive work, illustrated worthily, and this award is especially intended to mark the sympathy of the Council with Dr. Fritsch in his endeavours to adequately make known the Permian fauna, and in the hope that the fund may assist him in completing a work which has already taken high rank among _ paleontological monographs. Prof. Szruey felt sure that Dr. Fritsch would duly appreciate the honour of the award made him by the Council. The Prestpent then proceeded to read his Anniversary Address, which was devoted to the analysis and distribution of the British Paleozoic fossils, and especially as to their distribution in the successive formations, elucidated by elaborate tables. The Address was prefaced by obituary notices of Fellows and Foreign Members of the Society deceased during the past year, including Dr. J. J. Bigsby, Mr. Searles V. Wood, Prof. Ansted, Dr. C. Nyst, M. Bosquet, and others. The ballot for the Council and Officers was taken, and the following were duly elected for the ensuing year :—President: R. Etheridge, Esq.,F.R.S.; L,and E, Vice- Presidents : John Kyans, D C.L., LL.D., F.R.S.; J. W. Hulke, Esq., F.R.S. ; Prof. J. Morris, M.A.; and H. C. Sorby, LL.D., F.R.S. Secretaries : Prof. T. G. Bonney, M.A., F.R.S.; Prof. J. W. Judd, F.R.S. Foreign Secretary : Warington W. Smyth, Esq., M.A., F.R.S. Treasurer: J. Gwyn Jefireys, LL.D., F.R.S. Council: H. Bauerman, Esq.; Bev. J. F. Blake, M.A.; Prof. T. G. Bonney, M.A., F.R.S.; W. Carruthers, Esq., F.R.S.:; Prof. P. M. Duncan, M.B., F.R.S.; Sir P. de M. Grey-Egerton, Bart., M.P., F.R.S.; R. Etheridge, Esq., F.R.S.; John Evans, D.C.L., LL,D., F.R.S.; Lieut.-Col. H. H. Godwin- Austen, F.R.S.; J. Clarke Hawkshaw, Esq., M.A.; Rev. Edwin Hill, M.A.; W. H. Hudlestone, Esq., M.A.; J. W, Hulke, Esq., F.R.S.; J. Gwyn Jeffreys, LL.D., F.R.S.; Prof. J. W. Judd, F.R.S.; Prof. N. 8. Maskelyne, M.A., M.P., F.R.S. ; J. Morris, Esq., M.A.; J. A. Phillips, Esq.; F. W. Rudler, Esq.; Prof. H. G. Seeley, F.R.S.; Warington W. Smyth, Esq., M.A., F.R.S. ; H. C. Sorby, LL.D., F.R.S.; H. Woodward, LL.D., F.R.S. 188 Reports and Proceedings— II.—February 23, 1881.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. A letter from Dr. John Kirk, communicated to the Society by the Right Hon. Earl Granville, dated :— ‘© H.M. Agency and Consulate General, Zanzibar, December 20, 1880. «My Lorp,—It may be of interest to record the occurrence here of an earthquake shock felt in the island of Zanzibar at 6:58 A.M., mean time, on the morning of the 18th inst. « Although the shock was very distinct, no damage appears to have been done to any buildings in town. ‘Tt is now twenty-four years since a similar shock has been here noticed; but on the mainland, especially in the vicinity of Ujiji, they are both more common and more severe than at the coast. “Shortly after the cable was laid between Mozambique and Delagoa Bay, the communication was suddenly interrupted after one of these earthquake shocks, which seems to have caused the falling in of rocks by which the cable was crushed. «7 have the honour to be, etc., “The Right Honourable Joun Kirk, Earl Granville, etc., etc., H.M. Agent and Consul-General, London. Zanzibar.”’ 2. “The Permian, Triassic, and Liassic Rocks of the Carlisle Basin.” By T. V. Holmes, Esq., F.G.S. The district discussed in the author’s paper was worked over by him when engaged on the Geological Survey, and consists of those parts of Cumberland and Dumfriesshire which adjoin the Solway. Its southern boundary is, approximately, a line ranging from Mary- port to Rose Castle on the River Caldew, and touching the Eden about two miles above Wetheral. On the east and north-east its limits are the immediate neighbourhoods of the junction of the rivers Eden and Irthing, Hethersgill on the Hether Burn, Bracken- hill Tower on the Line, and the Border Boundary on the Rivers Hsk and Sark; and in Dumffiesshire the small tract south of a line ranging from the junction of Scots Dyke with the Sark on the north- east, to Cummertrees on the south-west. The lowest bed in this area is the great Upper Permian or St. Bees Sandstone, which occupies a belt of country in the neighbour- hood of the outer boundary. Directly above St. Bees Sandstone, in the west of the district, lies a formation consisting of shales with gypsum, which, though 700 feet thick in the neighbourhood of Abbey Town, is nowhere visible, but is known solely from borings, the country west of the Caldew, and of the Hden below the junction of the two streams, being thickly drift-covered and almost section- less. In the east of the district the St. Bees Sandstone is overlain directly by a soft, red, false-bedded sandstone, called by the author Kirklinton Sandstone, from the locality in which the rock is best seen, as well as its relations to the under- and overlying beds. But while there is no evidence of any unconformity between the St. Geological Society of London. 189 Bees Sandstone and the overlying Gypseous Shales in the west, there is evidence of a decided unconformity between the St. Bees and Kirkiinton Sandstones in the east. In Carwinley Burn (for example), which runs into the Esk at Netherby, only from 200 to 000 feet of St. Bees stone was seen below the outcrop of the Kirklinton, instead of the 1000 to 1500 feet which probably exist about Brampton on the one hand and in Dumfriesshire on the other. Yet Carwinley Burn affords an almost continuous series of sections, from the (non-faulted) Permian-Carboniferous junction to some distance above the outcrop of the Kirklinton Sandstone. As, in addition, the shales underlying the St. Bees Sandstone are gypseous, both near Carlisle and at Barrowmouth, close to St. Bees Head, the author classed the (Upper) Gypseous Shales as Permian, and the Kirklinton Sandstone as Bunter. Resting unconformably on the Kirklinton Sandstone, in the district between Carlisle and Kirklinton, are the Marls seen on the Eden, between Stanwix and Beaumont, and on the Line between Westlinton and Cliff Bridge, Kirklinton. Their unconformity is shown by the fact that on the Line they rest on the lower, or red, beds, and between Stanwix and Beaumont on the upper, or white, beds of the Kirklinton Sandstone. The Marls have therefore been classed as Keuper. So far as the evidence goes, they appear to be very thin and to extend but a very small distance south of the Eden. Lastly. the Lias appeared to the author to be unconformable to all the beds below, and to rest partly on the Gypseous Shales, partly on the Kirklinton Sandstone, and partly on the Keuper Marls. Of the existence of Rhetic beds there was no evidence, all fossils hitherto found having been determined by Mr. Etheridge (our President) to be Lower-Lias forms. But the Lias-sections are so small and few in number, and the ground so persistently drift-covered, that only a boring could settle the question. 3. “On Astroconia Granti, a new Lyssakine Hexactinellid from the Silurian Formation of Canada.” By Prof. W. J. Sollas, M.A., F.G.S. This paper contained a description of a new fossil Hexactinellid sponge from the Niagara chert beds of Hamilton, Ontario. It is the second oldest known example of the Lyssakina. Some remarks were added on the mineral state of the spicules and their association with chert. The author proposed for it the name of Astroconia Granti, the former in allusion to the peculiarly spinose character of rays of the sexradiate spicules. 'The anchoring spicules were de- scribed as consisting of a straight shaft with four recurved rays, each having a small bifid spine near the base on the outer surface. III.—March 9, 1881.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. “Description of Parts of the Skeleton of an Anomodont Reptile (Platypodosaurus robustus, Ow.).—Part Ii. The Pelvis.” By Prof. Owen, C.B., F.R.S., F.G.S., ete. _ In this paper the author described the remains of the pelvis of 190 Reports and Proceedings— Platypodosaurus robustus, which have now been relieved from the matrix, including the sacrum, the right “os innominatum,” and a great part of the left lium. There are five sacral vertebra, which the author believes to be the total number in Platypodosaurus. The neural canal of the last lumbar vertebra is 8 lines in diameter, and of the first sacral 9 lines, diminishing to 6 lines in the fifth, and in- dicating an expansion of the myelon in the sacral region, which is in accordance with the great development of the hind limbs. The sacral vertebra increase in width to the third; the fourth has the widest centrum. This coalescence of the vertebree justifies the con- sideration of the mass, as in Mammalia, as one bone or “ sacrum.” which may be regarded as approaching in shape that of the Mega- therioid Mammals, although including fewer vertebra. Its length is TL inches; its greatest breadth, at the third vertebra, 54 inches. The ilium forms the anterior and dorsal walls of the acetabulum, the posterior and postero-ventral walls of which are formed by the ischium and pubis. ‘The diameter of its outlet is 38 inches, the depth of the cavity 14 inch; at its bottom is a fossa 14 inch broad. The foramen is subcircular, 1 inch in diameter. The ventral wall of the pelvic outlet is chiefly formed by the pubis; it is a plate of bone 6 inches broad, concave externally, convex towards the pelvic cavity. The subacetabular border is 7-8 lines thick; it shows no indication of a pectineal process, or of a prominence for the support of a mar- supial bone. The author remarks that of all examples of pelvic structure in extinct Reptilia this departs furthest from any modifica- tion known in existing types, and makes the nearest approach to the Mammalian pelvis. This is shown especially by the number of sacral vertebre and their breadth, by the breadth of the iliac bones, and by the extent of confluence of the expanded ischia and pubes. 2. “On the Order Theriodontia, with a Description of a New Genus and Species (Ailurosaurus felinus, Ow.).” By Prof. Owen, C.B., E.R.S., F.G.S. The new form of Theriodont reptile described by the author in this paper under the name of #lurosaurus felinus is represented by a skull with the lower jaw, obtained by Mr. Thomas Bain from the Trias of Gough, in the Karoo district of South Africa. The postorbital part is broken away. The animal is mononarial ; the alveolar border of the upper jaw is slightly sinuous, concave above the incisors, convex above the canines and molars, and then straight to beneath the orbits. The alveolar border of the mandible is concealed by the overlapping teeth of the upper jaw; its symphsis is deep, slanting backward, and destitute of any trace of suture; the length of the mandible is 31 inches, which was probably the length of the skull. The incisors are =, and the molars probably = or $4, all more or less laniariform. The length of the exserted crown of the upper canine is 12 millims. ; the root of the left upper canine was found to be twice this length, extending upwards and backwards, slightly expanded, and then a little narrowed to the open end of the pulp-cavity. There is no trace of a successional canine; but the condition of the pulp-cavity and petrified pulp would seem to indicate renewal of the working Geological Society of London. 1D part of the canine by continuys growth. The author infers that the animal was monophyodont. #lurosaurus was said to be most nearly allied to Zycosaurus, but its in-isor formula is Dasyurine. With regard to the characters of the Theriodontia the author re- marked that we may now add to those given in his ‘ Catalogue of South African Fossil Reptiles,’ that the humerus is perforated by an entepicondylar foramen and the dentition is monophyodont. 3. “Additional Observations on the Superficial Geology of British Columbia and its Adjacent Regions.” By G. M. Dawson, Hsq., D.Sc., F.G.S. This paper is in continuation of two already published in the Society’s Journal (vol. xxxi. p. 603, and vol. xxxv. p. 89). In sub- sequent examinations of the southern part of the interior of British Columbia the author has been able to find traces of glaciation in a N. to S. direction as far as or even beyond the 49th parallel. Jron Mountain, for instance, 3500 feet above the neighbouring valleys, 5280 feet above the sea, has its summit strongly ice-worn in direction N. 29° W.-S. 29° H. Other remarkable instances are given which can hardly be explained by local glaciers; boulder-clay is spread over the entire district; terraces are cut in the rearranged material of this, bordering the river-valleys, and at greater elevations expand- ing over the higher parts of the plateau and mountains. At Mount It-ga-chuz they are 5270 feet above the sea. The author considers that the higher terraces can only be explainéd by a general flooding of the district. Some of the wide trough-like valleys of the plateau contain a silty material which the author regards as a glacial mud. North of the 54th parallel and west of the Rocky Mountains similar evidence of glaciation is obtained; erratics are found in the Peace and Athabasca basins. The fjords of British Columbia are extremely glaciated, the marls being generally in conformity with the local features; terraces are scarce and at low levels. The Strait of Georgia was filled by a glacier which overrode the §.E. part of Vancouver’s Island; evidence is given to show that this ice came from the neighbouring mountainous country. Queen Charlotte’s Island shows evidence of local glaciation. Boulder-clays and stratified drifts are found, with occasional arctic shells. The author considers that the most probable explanation of the phenomena of the whole region is to suppose the former existence of a great glacier mass resembling the inland ice of Greenland, and that the Glacial period was closed by a general submergence, during which the drifts were deposited and, at its close, the terraces cut. Erratum.—In the March Number, page 188, line 15, of the Got. Mae., for stromatoporides read stomatoporides. 192 Correspondence—MUr. W. Keeping. COR Ss Oa Dania i FOREIGN PEBBLES OF BRITISH BEACHES. Srr,—It is no doubt well known to Mr. Birds as well as many other observers, that the foreign pebbles, described by him! from the Brighton and St. Leonard Beaches, are not confined to the S.E. and 8. coasts of Hngland, they being indeed far more abundant in some places on the opposite coast of Britain. Aberystwyth, in the centre of Cardigan Bay, is, like Brighton, celebrated for the “pebble” riches of its beach, which aftord em- ployment to a large number of lapidaries in their cutting and polish- ing. Now these ‘“‘ pebbles” are all of them foreign to the district, and many of them are not even British in origin. Flint agates and “onyx” are not uncommon, and jasper is abundant. Besides these there are large numbers of other interesting strangers, many of them igneous rocks, including granites and quartz-felsites in many varieties, both pink and grey; orthoclase-felsite, porphyrites, basalt, and serpentine, and volcanic agglomerate ; also numerous sedimentary and metamorphic rocks. So abundant are these foreign rocks that in some of the small Welsh bays they are decidedly more conspicuous than the local stones, and handfuls may be gathered in a square yard. As to the origin of these pebbles I quite agree with Mr. Birds, that they are washed up from deposits now covered by the sea. I am not, however, able to see how these facts can determine for us the distribution of any vast ice-sheets such as Dr. Croll has described. To settle this question we must find whether the Boulder-clay was a true Till—a land-ice product, or only a marine Boulder-clay, stored with pebbles dropped from melting icebergs; and this cannot be settled by reference to the pebbles found on the beaches. Now, in the case of the foreign stones of the Welsh shingles, none of them occur in the drifts of the neighbouring country, these drifts being entirely the products of local land-ice; but I have detected some of them in the drifts of the lowlands of Anglesea. These latter are, however, marine Boulder-clays—laminated deposits like the Norfolk Contorted Drift, and containing delicate marine shells in perfect preservation. Therefore, I conclude that the foreign pebbles of the beaches are derived, not from any morainic formation produced by a vast ice- sheet, but from a Boulder-clay, formed as a marine deposit in the Trish Sea at a time when that sea was traversed by icebergs, brought hither by currents from the glaciers of Scotland, and Scandinavia. The original homes of many of the rocks are unknown to me. There are many Scotch porphyrites, and a few rocks from the Lleyn peninsula. The flints and some basalts may have come from the North of Ireland. W. Kempine. Tue Museum, York. 1 See Grou. Mac. January, 1881, p. 47. Geol. Mag. 1881. Decade II. Vol. VII. Pl. VI. Tae Ae Seat lal Zenaspis Salweyi, (Egerton, sp.) (Cephalaspis Asterolepis.) from the Old Red Sandstone skerrid Vawr, near Abergavenny. THE GEOLOGICAL MAGAZINE. NEW SERIES) DECADE=Il2 VOL. VIII. No. V.—MAY, 1881. Oreo ae GS aleaIN Acta | ASSES alesis @ En SS. ———— I.—Note oN A FINE Heap-sHieLtp or Zzewaspis (CEPHALASPIS) SaLweyi, EGERTON SP.= C&PHALASPIS ASTEROLEPIS, HaRury. By tue Epriror. (PLATE VI.) N our Plate is depicted the head-shield of the well-known Old Red Sandstone fish, Cephalaspis, the genus first described by Agassiz in 1835, the species C. Salweyi, by Egerton in 1857, and still later as C. asterolepis, by Harley in 1859. The specimen was obtained by Mr. John Edward Lee, F.G.S., of Torquay, from. the “Cornstones,” Old Red Sandstone, Skerrid Vawr, near Abergavenny, and is drawn about one-third less than the natural size. ‘Two cornua were obtained by Dr. Mac Cullough from the same quarry at Abergavenny, furnishing the evidence of these parts which are wanting in Mr. Lee’s specimen” (Lankester). At page 53 of Professor Lankester’s Monograph of Old Red Sand- stone Fishes (Part I. Cephalaspide, Pal. Soc. Mon., 1870) is given a life-size outline woodcut of this specimen; but the breadth seems somewhat too wide in proportion to the length of the shield, which in Mr. Lee’s specimen is more pointed in front. Mr. Lankester observes (op. cit. p. 54), “Another specimen has been recently obtained for the British Museum which is better than that in the Geological Survey Museum drawn on pl. xii. fig. 2; or than Mr. Salwey’s specimen ”’ (see pl. xii. fig. 6). These specimens seldom show the outer tuberculated layer, upon the character of which the specific differences between C. Salweyi and C. asterolepis have been founded. On some of these specimens a few of the tubercles are left here and there, but as a rule they merely show the beautiful stellate polygonal structure beneath the outer layer. Prof. Lankester observes, “Sir Philip Egerton attached importance to the great breadth between the eyes, but the size of the individual and variations in pressure are liable to affect this character.” He adds, “‘ After some hesitation I have decided to associate C. Salweyi and C. asterolepis as one species, not being able, on careful examina- tion, to find any character which should separate the large specimen described by Dr. Harley from Sir Philip Egerton’s original C. Salweyi.” Concerning the genus, Prof. Lankester proposes (op. cit. p. 55) DECADE II.—VOL, VIII.—NO. Vv. 13 194 &. D. Roberts—On the Twt Hill Conglomerate, Carnarvon. to place this large head-shield with others in the sub-genus Zenaspis, on the ground that with it have been found associated some remarkable scutes which are regular in size and hemispherical in outline. These scutes are symmetrical in outline, and were probably placed in the median line on the dorsal surface. They indicate an armature of body quite different from that of C. Lyelli. The flank-scales of individuals as large as Mr. J. H. Lee’s specimen must have been of considerable size and strength. We are indebted to Mr. J. E. Lee for kindly permitting us to reproduce the plate of this fine fossil in the Grotocican Maqazine. IJ.—EvipEncE BEARING UPON THE Position or THE Twr Hub CONGLOMERATE. By R. D. Rozerts, M.A., D.Sc. (Lond.), F.G.S., Clare College, Cambridge. DISCUSSION has more than once arisen, in the course of the last two years, respecting the true position of the quartz conglomerate exposed near Twt Hill, Carnarvon, which was first described by Prof. Bonney and Mr. Houghton in the Quarterly Journal of the Geological Society, vol. xxxv. p. 821. The typical quarry is situated on the S.H. side of the ridge, close underneath Twt Hill, and the exposure there shows the quartz conglomerate in juxtaposition to the granitoid rock that constitutes the axis of the ridge. The authors describe a passage between the granitoidite below and the conglomerate above, and state that the latter “‘ passes up into a rock which has some resemblance to the bottom rock” (granitoidite). In the Gon. Mac. for March, 1880, p. 118, Dr. Callaway writes: ‘‘Messrs. Bonney and Houghton have detected at Twt Hill a passage between the granitoidite and a quartzose con- glomerate with a 8.E. dip. I have visited this section, and having examined the rock inch by inch, I can entirely confirm their identi- fication.” a, Granitoid Rock of ‘'wt Hill. c¢. Sandstone. b. Quartz Conglomerate. f. Small Faults. To this view of the position of the quartz conglomerate as a part of the lowest Pre-Cambrian series, Prof. Hughes took ex- ception; a careful study of the stratigraphical relations of the R. D. Roberts—On the Tut Hill Conglomerate, Carnarvon. 195 beds having led him to refer the conglomerate to the base of the Cambrian. Prof. Hughes’s wide experience and acknowledged ability as a field geologist give great weight to his opinion on matters of stratigraphy, but certain difficulties have presented themselves, which cannot be lightly passed over. Apart from the alleged passage of the conglomerate into granitoidite, described by Prof. Bonney, Mr. Houghton and Dr. Callaway, there is the fact that the Cambrian conglomerate of the Bangor district and other parts of Carnarvonshire is largely made up of pebbles of felsite, while the Twt Hill conglomerate is composed chiefly of quartz pebbles and contains no felsite. These objections I believe I am in a position to meet. A recent visit to certain sections in Anglesea, and a re-examina- tion of the beds at T'wt Hill, under specially favourable conditions, enables me to offer additional evidence strongly confirmatory of Prof. Hughes’s view that the bed in question is the Cambrian con- glomerate. The following is the substance of notes taken during several visits to the Twt Hill quarry, and confirmed on the 6th of January, when I last visited the district. The quarry was on that occasion free from brambles and undergrowth, which in the summer somewhat obscured the section, and the relations of the beds were clearly shown. On the N.N.W. side of the quarry—western corner—the granitoid rock is succeeded by the conglomerate, which in some parts is fine, in others coarse. The pebbles are mostly quartz; very rarely one of dark quartzite or schist may be found. They vary Fic. 2. Section in Twt Hill Quarry from a to ¢ (Ground Plan). SSE. from the size of a grain of wheat to that of a pigeon’s egg. The quartz pebbles frequently exhibit a glazed appearance, and the matrix contains crystals of iron pyrites disseminated through it. The conglomerate stretches E.N.E. and dips S.S.H. at an angle of about 50°. Succeeding it and bounding the southern rim of the quarry is a bed of sandstone, which may also be detected a few feet beyond the quarry. That this rock is not similar to the bottom rock (granitoidite) is clear from the character of the bed, but to remove all shadow of doubt, I have procured a section of the rock for the microscope, and the result completely bears out the stratigraphical inference. Standing in the quarry, and facing towards the N.N.W., the conglomerate is seen dipping down the rock-face towards the spectator, clinging as it were in patches to the underlying granitoidite so as to give an appearance of beds dipping to the S.W. It is much decomposed by the weather, and the pebbles may with ease be picked out. The rocks are much traversed by fissures, which frequently show slickensided surfaces indicating movement, and in 196 &. D. Roberts—On the Twt Hill Conglomerate, Carnarvon. many instances small shifts may be detected by carefully tracing bands of rock across the fissures. Many of the cases of apparent passage proved on close examination to be the result of small faults bringing into intimate juxtaposition the conglomerate and granitoidite. The decomposition at the junctions in parts also rendered it difficult at first sight to make out the relations of the rocks, but after several hours’ careful examination of the section at different times, I enter- tain no doubt that the conglomerate is quite distinct from the granitoidite and belongs to a later period. At the eastern end of the quarry the typical granitoid rock is quarried, and it presents considerable variation in appearance in different parts of the quarry; it is traversed at one spot by bands of white quartz, which might well have furnished the materials of the pebbles in the conglomerate. More than once in a N.H. direction these beds are again exposed, notably in a quarry between Tygwyn and Ysyuborwen. There the conglomerate is seen some- what coarser in character than in the Twt Hill quarry, alternating with beds of grit and sandstone and showing the same strike and dip. Pebbles of jasper, quartzite and schist are rather more numerous here and the character of the bed is well shown. The evidence seems therefore clearly against the view that the conglomerate with its associated grits and sandstones is a part of the Pre-Cambrian granitoid series. On the other hand nothing hitherto said points conclusively to the base of the Cambrian’as the true position of these beds. To the complete and final settlement of the matter it is necessary that either undoubted fossiliferous Cambrian beds should be traced down into the deposits in question, or better still that fossils should be found in the sandstones themselves overlying the conglomerate. Both these demands can, I believe, be satisfied. The evidence has been obtained in another district. where the exposures are more numerous and the stratigraphical relations more readily made out than in Carnarvonshire. On two occasions last year I had the advantage of being conducted by Prof. Hughes over parts of Anglesea, where we found beds not distinguishable from those exposed at Twt Hill. I shall refer to three sections. 1. On the shore in Dulas Bay, a few miles to the 8.H. of Amlwch, black slates occur, in which we had the good fortune to discover Graptolites. These will be described in a forthcoming paper by Prof. Hughes. We traced the beds inland, and finally made a traverse across the strike with the object of finding if possible the basement conglomerate. The black slates we traced passing down into brown sandstones, and these into a conglomerate identical in petrological character with the Twt Hill conglomerate. It is well shown in a quarry at Penlon, about two miles due west of Traeth Dulas. The appearance of the quarry is singularly like that at Twt Hill. The conglomerate, made up of quartz pebbles, rests on granitoid rock and passes up into brown sandstones. 2. Dr. Callaway states in the Geonogroan Magazine, for March, 1880, p. 118, that near Nebo, two miles §.H. of Amlwch, he discovered in two quarries a quartzose conglomerate, “ lithologically T. Mellard Reade—Molian Sandstone. 197 perfectly indistinguishable from the Twt Hill rock,” which he holds to be unconformably overlaid by black Cambrian shales, and thus according to his view proving the Pre-Cambrian age of the grit. In company with Prof. Hughes, I visited these quarries towards the close of last year. We found the conglomerate and grit and the black shales against them, but saw no unconformability. The black shales crushed and broken at the junction! are faulted against the conglomerate in the manner shown in Fig. 3. Fie. 3. Section in Quarry } E.S.K. of Nebo, Amlwch. a. Black slate. 6. Jointed and veined grit conglomerate in parts. f. Fault. In the larger quarry the grit and conglomerate are much traversed by joints running in the same direction as the fault, which joints might easily be mistaken for lines of bedding, and the shale would then appear to be resting on the ‘upturned edges” of the con- glomerate. These sections, therefore, do not bear out Dr. Callaway’s interpretation. 3. About a mile and a quarter from Llanerchymedd, on the 8.W. road, not far from Bryngwallen, the granitoid series is exposed in a quarry on the S. side of the road. On the opposite side, in a field, about 50 yards from the road, another quarry has been opened in beds of grit and conglomerate. The latter is composed of pebbles of quartz, imbedded in a matrix containing crystals of pyrites, and resembles in all respects the conglomerates of Penlon, Nebo, and Twt Hill. It passes up, as does the conglomerate in the other sections, into grit and sandstone. The sandstone only a few feet from the conglomerate includes a fossiliferous band containing Orthides. This fixes the position of the sandstones and with them the quartz conglomerate into which they pass. Even if it be denied that this conglomerate and the Twt Hill conglomerate are identical in spite of their singular resemblance to one another, this discovery removes the only really strong a priori argument against referring the Twt Hill bed to the Cambrian series, viz. the absence of felsite pebbles. The Bryngwallen conglomerate, which passes up into fossiliferous sandstone, is composed of pebbles of quartz, imbedded in a felspathic matrix and is not distinguishable in the field from the Twt Hill conglomerate: ie bons SANDSTONE. By T. Mezztarp Reape, C.E., F.G.S. 8 bearing upon the subject of Mr. J. Arthur Phillips’s interest- ing ine valuable paper in the last number of the Quarterly Journal of the Geological Society, entitled, ‘On the Constitution and History of Grits and Sandstones,” a description of a cliff section of blown sand now to be seen on the coast at Crosby may not be 198 H. H. Howorth—The Mammoth in Europe. without value. The section in question, which attracted the attention of a local geologist, Mr. William Semmons, and myself, is at a point on the coast where the sea is encroaching upon the sand-dunes, and washing them away at the base leaves the face almost vertical. The resemblance of the sand to rock is most striking, presenting all those peculiarities of cross-bedding and lines of erosion we are familiar with in some of the Triassic sandstones of the neighbourhood. During the last twelve years, in walks along the shore, 1 have often observed the laminations of the blown sand disclosed by denudation, but never so strikingly as in the present case. The beds not only display delicate laminations, but stand out in ribs and cornices, simulating Gothic mouldings in profile. On trying how so loose a material as blown sand could retain these projecting forms, I was surprised to find the projections comparatively hard and solid. On breaking a piece off, the reason became apparent; for instead of the usually dry incoherent grains of sand, below the surface-skin the sand was quite damp. A very little addition of siliceous or calcareous cement would turn the mass into rock. The explanation is obvious. The late very wet winter has allowed the entire mass of the sand-hills to become saturated with moisture, and the water adhering to the grains gives them cohesion. The sea saps the base, and the wind acting upon the vertical face of the sand so produced, developes the latent form of rock-structure contained within it. The microscope shows that the grains are much rounded, but in this case not solely by wind action. There is no doubt that the grains of sand, before being finally built up into sand-dunes, are washed over the shore again and again. They are blown over the shore at neaps in strong winds, and as often devoured again by the sea. We are also unaware of the initial shape of the grains, as I have no doubt they are primarily derived from the Triassic rocks, and secondarily in part from the drift. The rounding may therefore be the result of ages of abrasion. What wonder then that Mr. Phillips finds that five miles of travel down stream did little or nothing towards rounding grains of siliceous sand ! Outside the estuary of the Mersey are great sand-banks, such as the Burbo Bank, continually shifting, yet preserving a certain permanence of form. Admiral Spratt, F.R.S., the Acting Con- servator of the Mersey, in his report for 1879, considers that the sand is continually travelling in great circles, in directions he particularly describes, round these banks. Here then is a great grinding mill for rounding the grains, as doubtless many of them have been on the banks before getting washed on to the shore. IV.—Tue Mammorn 1x Hurorz.! By Henry H. Howorrn, F.S.A. AVING considered the conditions under which the Mammoth lived in Siberia, we now propose to turn to the parallel problem in Europe, and to show that the mode of life was practically 1 Continued from the GronocicaL Macazing, 1880, Decade IT. Vol. VII. p. 561. H. H. Howorth—The Mammoth in Europe. 199 the same in both areas, and that the problem which has to be solved is virtually the same in both. It is true that in Siberia we find carcases of the Mammoth remaining with their flesh intact, a circumstance which is not known in Europe; but this is entirely due to the fact that the ground in no part of Europe which has been sufficiently explored is frozen all the year round, so as to enable the soft parts of the Mammoth to be preserved. The country east of the White Sea, and between it and the great gulf of the Obi, may very possibly satisfy this con- dition; but it is virtually a terra incognita in regard to its geology, and it is only recently that its superficial aspects have been examined with any attention. Elsewhere in Europe, the ground in summer is not permanently frozen, and it therefore cannot preserve what is so subject to rapid decay as the flesh of animals. But, although we have not the flesh itself, we have what is equivalent to it for our purpose, namely, the preservation of skeletons, with their various bones remaining in position, and under circumstances which make it clear that when buried they were clothed with flesh, just as the bodies in Northern Siberia were, and that it is only an absence of the requisite cold which has interfered with their complete preserva- tion. We find in Europe what we find in Central Siberia. There also the cold is not sufficient, and in consequence we have in that area no bodies with their flesh, but only skeletons. Such an one was that found by Messerschmidt on the river Tom, south of Tomsk, and referred to by Strahlenberg, and another referred to by the same author, found near Lake Tzana, between Tara and Tomskoi, which, from his account, still retained its articulations (Strahlen- berg, p. 404). To most of us it is difficult to realize how purely artificial the terms Europe and Asia are. How they correspond to nothing, either in historical or physical geography. ‘The Ural mountains form no frontier that has been of the slightest interest in history, while as a physical formation they are of even less importance. Their moderate height and frequent passes have formed no barriers, either botanical or zoological, ‘and the country with its living facies is practically the same on both sides of the chain. It is not a mere figure of speech by which my friend Mr. Seebohm, in describing his recent journey to the Petschora, calls that area ‘Siberia in Europe.” Siberia, as a physical province, really begins with the great Polish plain, and includes the monotonous levels of European Russia. This being so, it is not remarkable that we should find in European Russia, skeletons of Mammoths occurring under similar conditions to those of Siberia, and equivalent, as we have seen, if the conditions of climate were the same, to the occurrence of bodies with their flesh intact. The most important of these, and the one of whose discovery we have the greatest details, was found about the year 1846, near Moscow. The skeleton was found at Troitzkoe, not far from Khoroschowo, in the bed of a dried-up stream, which must once have fallen into the river Moskwa. It was described by Prof. Charles Kouillier, the then Secretary of the Imperial Society of 200 H. H. Howorth—The Mammoth in Europe. Naturalists. The skeleton was standing vertically, the fore-feet having sunk lower than the hind ones, and Brandt says that it must have sunk down in soft mud. His remaining remarks are so exactly what I would urge, that I prefer to quote them in the original as the words of a very skilled paleontologist. He says: “‘ Wiirde das Moskauer Governement damals einen ewig gefroreren Boden besessen haben und noch bis auf heute besitzen ahnlich wie der Norden Siberiens, so wiirde das fragliche Mammuth wohl als ganzes Cadaver zum Vorschein gekommen sein.”—Bulletin de la Soc. Imp. des Natur. de Moscou, vol. xi. part 11. p. 250. About 1826, according to a communication made by Pander to Brandt, there was found on the banks of a river near Petersburgh the skeleton of a Mammoth, which was also in an upright position (Bericht ueber die Verhandl. Berliner Acad., 1846, pp. 225, 226). This skeleton may be paired with another discovered in 17705 at Swijatosski, 17 versts from St. Petersburgh, and which is mentioned by Buffon (see De Blainville, Osteographie, p. 108). Tilesius mentions that a complete Mammoth’s skeleton was found at Struchof in the government of Kazan. In 1821, as appears from a letter written to Cuvier from St. Petersburgh, there were found, in the government of Woronej, two entire skeletons, whose tusks, although broken, were many feet long. It was argued these were the remains of elephants brought to Russia during the invasion of the Tartar, Mamai (Cuvier, Ossemens Fossiles, “VOL, thy [D> Ios). Travelling to another corner of European Russia, Von Nordmann mentions the discovery of a complete skeleton 40 versts from Odessa, seven fathoms under the ground, of which he secured a portion of a hip bone and two tarsi (Paleontologie Stdrusslands, . 273). ; In Western Russia, De Blainville reports the fishing up of the molar of a young animal with other bones of the skeleton from the river Uscha, near the Obrinka, not far from Grodno (op. cit. p. 112). Hagenius (Beitrage zur kunde Preussens, vol. i. p. 56) reports how the illustrious “‘ Castellanus Sremensi’” had informed him that a whole skeleton of an elephant was found at the town of Gruczno on the Vistula, which was broken to pieces by the peasants, but he secured part of a tusk (see Baer, de Fossilibus Mammalium reliquis, p: 13). In Germany several cases are known. Of these the most famous, perhaps, were the two skeletons found at Tonna, in the province of Gotha. One of them was discovered in 1696, and a femur with the head of another, a humerus, some vertebrae and ribs, together with the skull, four molars, and two tusks were recovered. ‘Tentzel described the remains in the 19th volume of the Philosophical Transactions, and proved, by an elaborate examination, against the views of the doctors of Gotha, that these bones were not, lusus nature, but the remains of an elephant. The perfection of the skeleton may be judged from Tentzel’s words: “ Hquidem nihil dubitare attinet, quin omnia reperta sunt ad absolvendum H. H. Howorth—The Mammoth in Europe. 201 Elephanti sceleton necessaria”’ (see Tentzel, Epist. de Sceleto Eleph., Phil. Trans. vol. xix.; Cuvier, Ossemens Fossiles, 4th ed. vol. 1. pp. 81—84). A second skeleton described by Cuvier was discovered 50 feet from the former one. This was in a cramped and curved position, occupying a space 20 feet in length, the hind-feet being near the tusks. The latter had fallen out of the alveoles and were crossed (Cuvier, op. cit. p. 80). From the valley of the Oder we have the record in Volkmann’s Silesia subterranea of the discovery of the bones of a giant in digging the foundation of a church at Leignitz. These bones, like similar bones from other sites, were probably those of a Mammoth. Brockman (Hpist. itin. p. 80) mentions the finding of a skeleton of a Mammoth at Tiede, in the valley of the Ocker, a short distance from Wolfenbuttel, of which Leibnitz figured a molar tooth. Another skeleton was found at Osterode, at the foot of the Hartz, by Dr. Koenig. These finds are both mentioned by De Blainville, who adds that skeletons have also been found in the valley of the Unstrut (op. cit. p. 119). Schlotheim mentions an entire skeleton of a Rhinoceros found in 1784 at Ballenstedt, which was broken by the workmen (Cuvier, op. cit. p. 98). South Germany, with its mountainous contour, was not well adapted to the habits of the great pachyderms, and, like the mountainous district of Siberia, is not so fruitful in Mammoths’ remains as the more level country. We 4 fortiori, therefore, do not meet with so many cases of skeletons or parts of skeletons found more or less intact. In 1605 a tusk with some Elephants’ bones were found near Halle, in Suabia; the tusk still hangs in the church of Halle (Cuvier, op. cit. p.95). Schlotheim, in his Connais- sance des Petrifactions, p. 5, speaks of a skeleton found near Passau, at the confluence of the Inn and Danube (see Cuvier, op. cit. p. 97). In 1807 many portions of an elephant’s skeleton well preserved were found at Neustaedt or Vag Ugheli, on the Vag in Hungary (id. pp- 98, 99), 60009000 00000600 000000000000 900 ,, LOWE UBER 6 cob aden cébounobuseoocodoH0bs000 1000 ,, Productive Coal-measures ........ 2.2.0 eseeeees UBD 55 4911 The fuel obtained from these measures is a true bituminous coal, with—according to the analysis of Dr. Harrington—an average of 6:29 per cent. of ash, and 1-47 per cent. of water. It is admirably suited for most ordinary purposes, and is largely exported, chiefly to San Francisco, where, notwithstanding a heavy duty, it competes successfully with coals from the west coast of the United States, owing to its superior quality. The output of 1879 amounted to 241,000 tons, and is yearly increasing. In addition to the main area of Cretaceous rocks above described, there are numerous smaller patches, holding more or less coal, in different parts of Vancouver Island, several of which may yet prove important. In the Queen Charlotte Islands, Cretaceous rocks cover a consider- able area on the east coast, near Cumshewa and Skidegate Inlets. At Skidegate they hold true anthracite coal, which, besides being a circumstance of considerable geological interest, would become, if a really workable bed could be proved, a matter of great economic importance to the Pacific coast. At Skidegate, where these rocks are most typically developed, they admit of subdivision as follows, the order being, as before, descending : A. Upper shales and sandstones .................- 1500 feet. 13}, (Clomid Comellomenbnis, 6666000 doo 6004 00000000 2000 ,, C. Lower shales with coal and clay ironstone ...... 5000 ,, 10), AaaloGTENIES oo¢0.000006 00000060 co000000G00C 3500 ,, 19,, ILoere RANE 44650000 006000 00000000 G00 1000 ,, 13,000 216 G. I. Dawson—Geology of British Columbia. The total thickness is thus estimated at about 13,000 feet. With the exception of the agglomerates, the rocks in their general appearance and degree of induration compare closely with those of Vancouver Island. The agglomerates represent an important intercalation of volcanic material, which varies in texture, from beds holding angular masses a yard in diameter, to fine ash rocks, and appears at the junction to blend completely with the next overlying subdivision. ‘These beds are generally felspathic, and often more or less distinctly porphyritic. At the eastern margin of the formation the rocks lie at low angles, but become more disturbed as they approach the mountainous axis of the Islands, showing eventually in some cases overturned dips. It is in this disturbed region that the anthracite coal has been found, and from the condition of included woody fragments in the eastern portion of the area, it is probable that any coal seams discovered there would be bituminous, like those of Vancouver Island. Though it was originally supposed that the anthracite occurred in several beds, it has, I believe, now been shown’ that this appearance is due to the folding of a single seam which immediately overlies the agglomerate beds of subdivision D. The coal is associated with carbonaceous shales holding a species of Unio, but is succeeded, in ascending order, by beds charged with marine fossils, and fresh-water conditions are not known to have recurred at other horizons. It was where opened nearly vertical, and about six feet in thickness, but became thinner, and after about S00 tons of anthracite had been obtained, the mine was abandoned; the locality, however, still appears worthy of further and closer examination.? In regard to the geological horizon of the different Cretaceous areas above described, the most complete information has been obtained for the Nanaimo and Comox basins. Large collections made by Mr. Richardson, in connexion with the work of the Geological Survey, have now been described by Mr. J. F. Whiteaves.* These fossils are all from the lower portion of the formation, which is conclusively shown to represent the Chico group of the Californian geologists, which, with the locally developed Martinez group, is considered to be equivalent to the Lower and Upper Chalk of Europe. The highest subdivision of the Californian Cretaceous, the Tejon group, is supposed to represent the Maestricht, and in the’ absence of fossils from the upper portion of the Vancouver Island formation, itis possible that it may be equally young. The flora of the Vancouver Cretaceous consists largely of modern angiospermous and gymnospermous genera, such as Quercus, Platanus, Populus, and Sequoia ; several of the genera and a few of the species being com- 1 Report of Progress,Geol. Survey of Canada, 1878-79, p. 72 B. 2 For further information on the Cretaceous rocks of the coast, see Dr. Hector’s report in Palliser’s Exploration in North America, and Quart. Journ. Geol. Soc. vol. xvii. p. 428. Reports of Progress, Geol. Survey of Canada, 1871-2, p. 75; 1872-3, p. 32; 1873-4. p. 94; 1874-5, p. 82; 1876-7, p. 160; the last reference being Mr. J. Richardson’s complete report on the Nanaimo and Comox Basins, also pp. 119 and 144, 1878-9, p. 638, a detailed report on Queen Charlotte Islands by the writer. 3 Mesozoic Fossils, vol. i. part ii. G. WM. Dawson—Geology of British Columbia. 217 mon to it and to the Dakota group of the Middle Cretaceous of the interior region of the continent. The botanical evidence, while yet imperfect, is therefore by no means in contradiction to that afforded by the animals and the stratigraphy. A number of fossils from the Queen Charlotte Islands have also been described and figured! from Mr. Richardson’s collections made during a visit to the islands in 1872. Additional collections made by the writer in 1878, while considerably increasing the fauna, will enable more exact conclusions as to the horizon of the beds to be arrived at. There are few cases of specific identity between the forms in the Vancouver Cretaceous, previously described, and those of the Queen Charlotte Islands, the latter representing a lower stage in the Cretaceous formation. The plants found in these rocks, em- bracing numerous coniferous trees and a species of Cycad, also indicate a greater age than those of Vancouver. The coal-bearing beds at Quatsino Sound on the west coast of Vancouver Island, have also yielded a few fossils. These consist chiefly of well-characterized specimens of Aucella Piochiit, which occurs but sparingly in the Queen Charlotte Islands, and brings the rocks into close relations with the Aucella beds of the mainland of British Columbia, and in Mr. Whiteaves’ opinion probably indicate an “Upper Neocomian” age. The rocks of the Queen Charlotte Islands and Quatsino may therefore be taken together as represent- ing upper and lower portions of the so-called Shasta group of California, which in British Columbia can now be readily distin- guished by their fossils. On the mainland, developed most characteristically along the north-eastern border of the Coast Range, is a massive series of rocks first referred to by Mr. Selwyn, in the provisional classification adopted by him in 1871, as the Jackass Mountain group, from the name of the locality in which they are best displayed on the main waggon-road. The age of these rocks was not known at this time, but fossils have since been discovered in the locality above mentioned and in several others, the most characteristic forms being Aucella Piochii and Belemnites impressus. The rocks are generally hard sandstones or quartzites, with occasional argillites, and very thick beds of coarse conglomerate. A measured section on the Skagit includes over 4400 feet, without comprising the entire thickness of the formation. Behind Boston Bar, on the Fraser River, the formation is represented by nearly 5000 feet of rocks, while on Tatlayoco Lake it probably does not fall short of 7000 feet. At the last-named place these beds are found to rest ona series of felspathic rocks, evidently volcanic in origin, and often more or less distinctly porphyritic. On the Iltasyouco River, near the 51st parallel, and in similar relation to the Coast Range, an extensive formation characterized by rocks of volcanic origin, and often porphyritic, has also been found. Its thickness must be very great, and has been roughly estimated at one locality as 10,000 feet. It has been supposed, on lithological grounds, to represent the porphyritic 1 Mesozoic Fossils, vol. i. part i. 218 G. MW. Dawson—Geology of British Columbia. formation of the vicinity of 'latlayoco Lake, and fossils found in it have been described as Jurassic.’ From analogy now developed with the Queen Charlotte Island fauna, however, Mr. Whiteaves believes that these beds are also Cretaceous. Still further north the Cretaceous formation is not confined to the vicinity of the Coast Range, but spreads more widely eastward, being in all probability represented by the argillites and felspathic and calcareous sandstones of the Tower Nechacco; and, as the explorations of 1879 have shown, occupying a great extent of country on the 55th parallel about the upper part of the Skeena and Babine Lake. They here include felspathic rocks of volcanic origin similar to those of the Iltasyouco, which are most abundant on the eastern flanks of the Coast Range, and probably form the lower portion of the group. Besides these volcanic rocks, there is, however, a great thickness of comparatively soft sandstones and argillites, with beds of impure coal. The strata are arranged in a series of folds more or less abrupt, and have a general north-west and south- east strike. It is not impossible, from the general paleeontological identity of the rocks of the interior with the older of those of the coast, that the Skeena region may eventually be found to contain valuable coal-seams, but this part of the country is at present very difficult of access, and there is no inducement to explore it.? Rocks of the Vancouver and Coast Ranges.—Previous to the deposit of the Cretaceous, the older formations had been folded and dis- turbed, and were in degree of alteration much as at present. While there is therefore no difficulty in distinguishing the Cretaceous from the Pre-cretaceous rocks, the subdivision of the latter becomes in many instances a difficult matter, the generally wooded and inaccessible character of the country adding to the obscurity in many districts. Without therefore entering into detail in regard to the various groups, which it has been found necessary provisionally to constitute and name, I shall attempt to give a short connected sketch of these older rocks, beginning with those of the Coast. In 1872 Mr. Richardson described a section across the centre of Vancouver Island,* comprising a great thickness of beds which have been closely folded together and overturned. These consist of lime- stones, generally crystalline, but varying in texture and colour, interbedded with compact amygdaloidal and slaty volcanic rocks of contemporaneous origin. These are classed generally as “diorites” in the report cited, but admit of separation into several different species of igneous rocks, not here necessary to detail. Argillites also occur, but are apparently not prominent in the section. Fossils are found abundantly in some of the limestones, and though invariably in a poor state of preservation, the late Mr. Billings was able to distinguish, besides crinoidal remains, 1 Report of Progress, Geol. Survey of Canada, 1876-77, p. 150. 2 T am indebted to Mr. J. F. Whiteaves for facts in regard to the paleontological evidence of the horizons of the subdivisions of the Cretaceous, communicated in ad- vance of the publication of part iii. of the Mesozoie Fossils. 3 Report of Progress, Geol. Survey of Canada, 1872-78, pp. 52-56. G. MU. Dawson—Geology of British Columbia. 219 a Zaphrentis, a Diphiphyllum, a Productus, and a Spirifer, and pronounced the beds to be probably Carboniferous in age. Rocks belonging to the older series, unconformably underlying the Cretaceous, have now been examined in many additional localities on Vancouver Island, and, while no paleontological facts have been obtained to prove that they are older than those of the section above described, much circumstantial evidence has been collected to show that rocks even much more highly crystalline than those of the above section, and which, judged by standards locally adopted in Eastern America, would be supposed to be of great antiquity, represent approximately, at least, the same horizon. At the south-eastern extremity of the island, in the vicinity of Victoria, a series of rocks occurs which was placed by Mr. Selwyn, in his provisional classification of the rocks of British Columbia, under the title of the Vancouver Island and Cascade Crystalline Series... Mr. Selwyn, in speaking of these, remarks on_ their lithological similarity to the Huronian rocks, or those of the altered Quebec group of Eastern Canada. A somewhat detailed examination of this series has since been made, and shows it to be built up in great part of dioritic and felspathic materials, which in places become well characterized mica-schists, or even gneisses, while still else- where distinctly maintaining the character of volcanic ash-beds and agolomerates. With these are interbedded limestones, and occa- sionally ordinary blackish argillites. No more certain paleonto- logical evidence of the age of these beds than that afforded by some large crinoidal columns which occur in the limestones, has yet been obtained. These, however, suffice to show that they cannot be referred to a pre-Silurian date, and it is highly probable that they are actually a more altered portion of the series represented in the first described section, from which their greatest point of difference is found in the smaller proportionate importance of limestones. They occur in the continuation of the same axis of elevation at no very great distance, and the greater disturbance which they have suffered would serve te account for the higher degree of alteration in materials so susceptible of crystallization as those of volcanic origin. Elsewhere, in the vicinity of Vancouver Island, rocks holding fossils, which seem to be Carboniferous, and formed in part of volcanic materials, occur; and on Texada Island, beds probably of the same age are found, consisting of interstratified limestone or marble, magnetic iron ore, epidotic rock, diorite, and serpentine. Passing north-westward, along the same mountainous axis, to the Queen Charlotte Islands, we find the rocks there underlying the Cretaceous Coal series to present, in the main, features not dissimilar to those of Vancouver Island. Massive limestones, generally fine- grained, grey, and often cherty, are folded together with felspathic and dioritic rocks, sometimes so much altered as to have lost the evidence as to whether they were originally fragmental or molten. 1 Report of Progress, Geol. Survey of Canada, 1871-2, p. 52. 220 G. WM. Dawson—Geology of British Columbia. In other places they are still well-marked rough agglomerates, or amyedaloids. No characteristic fossils have been obtained from these rocks, but at the summit of this part of the series, and adhering closely to a limestone which apparently forms its upper member, occurs a great thickness of regularly-bedded blackish calcareous argillite, generally quite hard and much fractured, but holding numerous well-preserved fossils, including J/onotis subcircularis and other characteristic forms of the so-called “ Alpine Trias” of California and the 40th parallel region, which represents the Hollstadt and St. Cassian beds of Europe. The resemblance of the lower unfossiliferous rocks first described to the probably Carboniferous beds of Vancouver, leads to the belief that these may also be of the same age, while any slight unconformity between these and the Triassic may be masked by subsequent folding and disturbance. In the extreme north-western part of Vancouver Island Triassic rocks like those of the Queen Charlotte Islands occupy extensive but yet undefined areas, while the slaty auriferous rocks of Leach River, near Victoria, may also represent the Triassic argillites in a more altered state.? As already mentioned, Mr. Selwyn, in his provisional classification, unites under one title the older rocks of Vancouver Island, above described, and those which form the greater part of the Cascade or Coast Ranges. The progress in the investigation of the country seems to favour the correctness of this view, and to show a blending and interlocking of such characters of difference as the typical or originally examined localities of the two series present. ‘Tracing the rocks eastward from the shores of Vancouver Island, we find them becoming more disturbed and altered, the limestones always in the condition of marbles, and seldom or never showing organic traces, the other rocks represented chiefly by grey or green diorites, gneisses—generally hornblendic—and various species of felspathic rocks, such as may well be supposed to have resulted from the more complete crystallization of the voleanic members of the series. Recurring in a number of places, and folded with these rocks, is a zone of micaceous schists or argillites. The rocks classed as the Anderson River and Boston Bar series? in the provisional classification represent one fold of these schists, which may be supposed to be more or less exactly equivalent to the Triassic flagey argillites of the first mountainous axis. The Coast Range constitutes an uplift on a much greater scale than that of Vancouver and the Queen Charlotte Islands to the south- west of it, a circumstance which appears to have resulted in a more complete crystallization of its strata, and has also led to the intro- duction of great masses of hornblendic granite. These may in many places represent portions of the strata which have undergone incipient or complete fusion, in place. There is every evidence that in the Appalachian-like folding of this region the same rocks are | 1 Reports of Progress, Geol. Survey of Canada, 1878-9, p. 46 B; 1876-7, p. 95. * Report of Progress, Geol. Survey of Canada, 1871-2, p. 62. G. M. Dawson—Geology of British Columbia. 221 many times repeated. Last of the lower part of the Fraser River the folds have been completely overturned to the eastward. These rocks of the Coast Range have with other features of the country a great extension in a north-east and south-east bearing, stretching, with an average width of 100 miles at least, from the 49th parallel to Alaska, a distance of 500 or 600 miles. Pre-Cretaceous Rocks of the Interior.—North-east of the Coast ’ Range the older rocks of the interior plateau are more varied, but have in their different developments characters in common with each other and with those of the Coast Range, which draw them closely together. These rocks, which were included under the Lower and Upper Cache Creek groups of the original classification, may be said as a whole, in their present state, to consist of massive limestones, diorites or allied materials, felspathic rocks, compact agelomeritic or slaty quartzites and serpentines. The last-named rock occurs in association with the contemporaneous volcanic materials, and doubt- less represents the alteration product of olivine rocks. It is in beds of considerable thickness and wide-spread, and is of interest as bein g of a period so recent as the Carboniferous. The limestones are not unfrequently converted to coarse-grained marbles, and together with the quartzite appear in greatest force on the south-western side of the area they occupy. They have now been traced, maintaining their character pretty uniformly throughout, from the 49th to the 58rd parallel. Schistose, or slaty argillite rocks, which may represent those already described as folded with the Coast Range series, also occur, and a portion of these at least probably belongs to the over- lying Triassic or Jurassic division. In regard to the evidence of the age of the great mass of these rocks, forming the so-called Upper and Lower Cache Creek groups, the following points may be mentioned. A portion at least of the formation was in 1871 shown, by fossils collected by Mr. Selwyn, to belong to a horizon between the base of the Devonian and summit of the Permian. Additional fossils have since been procured, of which the most characteristic is the peculiarly Carboniferous foraminifer Fusulina. This has now been found in several localities, scattered over a wide area, and is associated at Marble Canon with the remark- able Loftusia Columbiana.' In the southern portion at least of the interior plateau region there exist, besides the Paleozoic rocks just described, and in addition to the probably in part Triassic argillites, extensive but as yet undefined areas of Triassic rocks of another character. These are in great part of volcanic origin, and have been designated the Nicola series. They have generally a characteristically green colour, but are occasionally purplish, and consist chiefly of felspathic rocks and diorites, the latter often more or less decomposed. The rocks are in some cases quite evidently amygdaloidal or fragmental, and hold toward the base beds of grey sub-crystalline limestone, intermingled in some places with volcanic material, and containing occasional layers of water-rounded detritus. The distinctly unconformable junction of this 1 Quart. Journ, Geol. Soc., 1879, p. 69. 222 G. IW. Dawson—Geology of British Columbia. series with the Cache Creek rocks is seen on the South Thompson, a few miles above Kamloops. In the Gold Range which borders on the interior plateau to the north-east, the conditions found in the Coast Range appear in many respects to be repeated. The rocks just described, but with less quartzite and limestone, and probably an added proportion of volcanic material, are found in a more or less highly altered state as gneisses, dioritic, hornblendic, and micaceous schists, and coarsely © crystalline marbles, while a belt of schistose and argillaceous beds, probably the same with that already several times referred to, and newer than the rocks just mentioned, is tightly folded with them, giving to this axis of elevation its famed auriferous character. No fossils have yet been found in the crystalline rocks of this range. Respecting the proved existence in it of a series of rocks older than elsewhere known in the province, the facts are given on a succeed- ing page. For the region to the north-east of the Gold Range, including the eastern flanks of the range, and the country between it and the Rocky Mountains proper, little information has been obtained. It is one exceedingly difficult of access, owing to its mountainous and densely-wooded character ; but the transition from the much-flexed rocks of the first-mentioned range to the comparatively little bent though much broken masses of the Rocky Mountains is probably pretty abrupt. Structure of the Rocky Mountains.—In the Rocky Mountains we have the broken margin of the undisturbed sheets of strata which underlie the great plains, projecting in block-like masses. In British America our geological knowledge of the range is confined to the observations of its extreme northern part by Sir J. Richardson, of its southern portions by Dr. Hector, a traverse on the Peace River by Mr. Selwyn, and my own observations in the last-named locality and on the 49th parallel. The most complete section is that in the vicinity of the 49th parallel,' to which I shall briefly refer, and then indicate points of difference between the rocks shown in it and those of the north- western continuation of the range. 'The total thickness of the beds here seen is about 4500 feet. The lowest are impure dolomites and fine dolomitic quartzites, dark purplish or grey, with a thickness of 700 feet or more. These may be of Cambrian age, and are supposed to represent the Pogonip formation of Clarence King’s 40th parallel section.” Overlying this is a pale grey cherty magnesian limestone, with magnesian grits, estimated at 200 feet in thickness, which is supposed to represent the Ute-Pogonip limestone of Silurian age of the 40th parallel section. Next in order is 2000 feet or more of sandstones, quartzites, and slaty rocks of various tints, but chiefly 1 Though the investigation of the rocks of this part of the Rocky Mountains was carried on quite independently, and reported on in 1875, it has been thought desirable to refer the formations as far as possible to King’s section, as being much the best hitherto published for the Rocky Mountain Region. * Geol, and Resources of 49th Parallel, p. 56. G. M. Dawson—CGeology of British Columbia. 223 reddish or greenish grey, holding also magnesian grits, and a well- marked zone of bright red beds. These may be equivalent to the Nevada Devonian and Ogden quartzites of the same age, on the 40th parallel. The Carboniferous is next represented by a massive bluish limestone 1000 feet in thickness, above which lies an amygdaloidal trap 50 to 100 feet thick, which maintains its place for at least twenty-five miles along the mountains. Above this are flaggy beds of magnesian limestone and sandstone with red sandstone, which become especially abundant towards the top, the thickness of the series being about 200 feet. The position of the upper line of the portion of the for- mation which should be referred to the Carboniferous is uncertain, but it is probable that a part at least of the beds last described belong to it. Passing gradually upwards from this series is about 400 feet of beds, characterized by a predominant red colour, and chiefly thin- bedded red sandstones, often ripple-marked, and showing on some surfaces impressions of salt crystals. Fawn-coloured magnesian sandstones and limestones occur towards the top. These without doubt represent the Triassic or Jura-Triassic red beds extensively developed everywhere to the southward, in the eastern ranges of the Cordillera region. North-westward, to the Athabasca River, Dr. Hector’s numerous excursions in this mountain axis prove the great mass of the range to be composed of Carboniferous and Devonian beds, which are pre- dominantly limestones, but it is also probable that some of the older rocks above described may occur. In the Peace River region, on the 55th and 56th parallels, the con- ditions are somewhat changed. Massive limestones of Devonian and probably also of Carboniferous age, associated with saccharoidal quartzites, here form the axial mountains. On the west side these are overlain by an extensive schistose series, in which micaceous schists and argillites, more or less altered, predominate. These are known to occupy a long trough east of the Parsnip River, and cross the Misinchinka, with considerable width. They are doubtless of the same age as the gold-bearing schists of Cariboo, before referred to, and while no fossils have here been found in them, a series of dark argillites on the eastern slope of the mountain axis which con- tain several Triassic forms—more particularly the characteristic Monotis—may, it is supposed, represent the continuation of the same series in a less altered state. These marine Monotis shales, it will be observed, seem to represent in this section the red beds of the region further south. Volcanic material appears to be entirely absent from the limestone series. While in the Rocky Mountains on the 49th parallel, formations extending downwards to the Cambrian have been identified with some degree to certainty, it will be observed that none older than Carboniferous or Devonian have so far been mentioned as occurring in other parts of the region. It is quite possible, however, that rocks of Silurian or even Cambrian age may exist, though the disturbed nature of the country has so far prevented their discovery. It has been attempted here merely to give a general sketch of the more 224 G. M. Dawson—Geology of British Columbia. important groups of rocks, which constitute the mass of the forma- tions of the Province. Still older rocks, which may indeed represent part of the Archean of the 40th parallel area, are known to occur, but about them little has yet been certainly determined. They appear at intervals in the Gold Range, and in the region between it and the Rocky Mountains. The rocks appear to be gneisses and granites, holding orthoclase felspar, and with abundant quartz and mica, very often garnetiferous and coarsely crystalline. They were originally classed with the schistose gold-bearing rocks of Cariboo and their representatives elsewhere, but we have already found reason to believe that these schists are much newer, and during the past summer those on the Misinchinka have been found to be charged with half-rounded quartz and felspar from the old rocks above mentioned, which must have been fully metamorphosed at the time of their deposition. A small area of these oldest and possibly Laurentian rocks occurs near Carp Lake in the northern part of the Province. They also exist in the Cariboo district, though they have not yet been defined there. They are described by Mr. Selwyn as occurring on the upper part of the North Thompson, and the gneissic rocks noted by Dr. Hector near the sources of the Athabasca, on the western side of the Rocky Mountain axis, probably belong to the same fundamental series. Physical Conditions implied by the Deposits.—This review of the state of knowledge of the rock series of British Columbia may well be concluded by glancing rapidly at the physical conditions implied in the production of the different formations. The oldest land surface of which we have any knowledge is that of the probably Archean rocks just described, and must have been in the region of the Gold Range of to-day. It may have extended farther westward in early Paleozoic time, forming a continental area like that supposed by King to have stretched west from the Wahsatch Mountains on the 40th parallel, but no trace of its existence to the eastward of the western margin of the Rocky Mountain Range has yet been found. In Devonian and Carboniferous times the geography of the region begins to outline itself more definitely. The probably Archean rocks at this time formed a more or less continuous barrier of land along the line of the Gold Range, between the interior con- tinental basin to the north-east and the Carboniferous Pacific to the south-west. In the-eastern sea organic limestones with sandy and shaly beds were being deposited, and in the vicinity of the 49th parallel at least one well-marked flow of igneous material evidences the existence of volcanic phenomena. In the west and south-west of the land barrier the conditions were widely different. Here, too, limestones were in process of formation, but extensive siliceous deposits were also forming, while a great chain of volcanic vents— submarine or partly subaerial—nearly coincident with the present position of the Coast Range and those of Vancouver and the Queen Charlotte Islands. Trap and agglomerate rocks were thus added to the series. Similar centres of volcanic activity may have existed in the vicinity of the land barrier on the west, whilst the finer felspathic G. M. Dawson—Geology of British Columbia. 225 material affected the composition of the argillites and other rocks, in progress of deposition, even at a great distance from any of the vents, and the series acquired a great thickness. Evidence of some disturbance at the close of the Carboniferous period is found in the unconformable superposition of the Nicola Triassic on these rocks, in the southern portion of the interior of the Province. This, however, appears to have affected the region to the west of the land barrier alone, and to have resulted in the more com- plete definition of this barrier, and probably to its increased elevation ; tor in Triassic and Jurassic times we find the deposition of the red beds and flagey dolomitic limestones with salt, going on to the east near the 49th parallel, and further south the actual inclusion of salt and beds of gypsum, proving that this region was then a shallow inland sea cut off from communication with the ocean. To the west of the land barrier on the contrary, in the Triassic, and probably also in the Jurassic, a great thickness of volcanic rocks with lime- stones and argillites was being formed along the border of the Pacific. The argillites of this period probably afterwards became the chief gold-bearing formation of the country, as is proved to have been the case in California. These with the volcanic accumulations doubtless represent the Star Peak and Koipato groups of the Triassic as described by King on the 40th parallel between the Sierra Nevada and the Wahsatch Ranges ; and though, as elsewhere stated,’ I have not been able to find that the existence of Carboniferous volcanic rocks has been recognized in the Sierra Nevada of California, it seems probable, from the description and appearance of the rocks, that more or less altered volcanic materials, perhaps both of Mesozoic and Paleozoic age, enter into its composition. A further circumstance of interest-in connexion with the Jura-Trias period is the evidence now obtained that the sea apparently spread uninterruptedly eastward across the Rocky Mountains and into the Peace River country, at least as far south as the 55th parallel. This is proved both by the lithological character of the rocks, and the fossils they contain,’ and we thus arrive at an approximate definition, not only of the western but also of the northern limits of the great inland sea, which extended south-eastward to New Mexico, though we still remain ignorant of the precise character of the northern barrier. This period was closed by a great disturbance along the whole Cordillera region. In California the Sierra Nevada rose up as a mass of crumpled and compressed folds. In the southern part of British Columbia the disturbance affected the region from the Gold Range to the coast, extending the land area westward to the 121st meridian, and giving, so far as is known, the first upthrust to the mountains of Vancouver and Queen Charlotte Islands, but forming no continuous range where the great belt of coast mountains now is. In the earliest beds of the Cretaceous there is evidence of a general slight subsidence in progress, with the formation of conglomerates, and we can trace the shore-line of the Cretaceous Pacific, which 1 Grou. Mac. 1877, p. 315. 2 See, on the latter point, Report of Progress, Geol. Survey, 1876-7, p. 158. DECADE II.—VOL. VIII.—NO. Y. 15 226 G. MW. Dawson—Geology of British Columbia. crosses the 49th parallel near the 121st meridian, southward to the Blue Mountains of Oregon, south-westward to Mount Shasta, and from this, according to Whitney, still further southward along the western slope of the Sierra Nevada. To the north it appears nearly to follow the present north-eastern line of the Coast Range to the d2nd parallel, when it turns north-eastward, passing completely across the line of the Gold Range, and by straits and openings through the Rocky Mountains on the 55th parallel, connecting this with the great Cretaceous Mediterranean Sea of the interior of the continent. In the southern part of British Columbia it would appear that the Rocky Mountains proper were not at this time elevated, but that the Cretaceous Mediterranean washed the eastern shore of the Gold Range. In the Peace River region, however, just mentioned, there is ample proof that the Rocky Mountains formed even at this time a more or less continuous shore-line or series of islands, around which the Cretaceous beds were deposited. The existence of a great thickness of rocks of volcanic origin in the Cretaceous of several parts of the Province has already been alluded to. Their resemblance to those described as occurring in the Cordillera region in Chile, by Darwin, has been pointed out by the writer in a former communication to the GzoLocrcaL MaGazine.* The Cretaceous closed with another period of folding, in which additional height was given to the Vancouver and Queen Charlotte Island Ranges, the Coast Ranges were produced, as well as cor- tugations doubtless caused still further eastward which cannot now be separated from those of other periods. At this time, or shortly after, the Rocky Mountains attained their full height and development. No trace of the earlier or Eocene Tertiary has been found in British Columbia, and it is probable that the Province was through- out at that time a land area. In the Miocene, the relative elevation of sea and land was much as at present, but the great inland lake formerly alluded to was in existence. This lake was doubtless the northern continuation or homologue of that which has been called the Pah-Ute Lake by Clarence King, and which lay east of the Sierra Nevada on the 40th parallel. The rocks formed in it thus represent the Truckee Miocene of King’s section. The Miocene closed with extensive volcanic disturbances through- out the country south-west of the Gold Range, and eventually by still another epoch of corrugation and crumpling probably synchro- nous with that which produced the Tertiary Coast Hills of California, and which may have given to the northern part of the coast the greater elevation, which it appears to have possessed during Plio- cene times, when the wonderful system of fiords, by which it is now dissected, were cut out. The most striking points brought out by the study of this region are probably the following. First, the repeated corrugation, parallel in the main toa single axis, which has occurred in the Cordillera region. Second, the occurrence of great and wide-spread masses of 1 Grou. Maa. 1877, p. 314. The rocks elsewhere described were at the time the article in question was written supposed to be Jurassic. Reviews—Chevalier Jervis—On Gold in Nature. Zot volcanic material at at least four distinct horizons, proving the activity for an immense period of the volcanic forces along this portion of the Pacific margin. Lastly, the sometimes almost insuper- able difficulty of distinguishing between volcanic rocks of different periods when they have suffered a like degree of metamorphism, and the inappropriateness of attempting to apply lithological standards, which have in eastern America or elsewhere been found locally useful in distinguishing between different series of crystalline rocks, in a region characterized by the abundance of easily crystallizable volcanic materials, and in which rocks of as late date as the Carboniferous have suffered a degree of metamorphism comparable to that of the Huronian or altered Quebec group of Hastern Canada. EVES ee Un I.—On Gotp in Nature. [Dei Oro in Nartoura, etc.] By Curvy. Wm. Jervis, F.G.S., Conservator of the Royal Italian Industrial Museum in Turin, etc. Small 8vo. 204 pages, with Woodeuts and Tables. (Turin, Loescher; London, Triibner & Co.) \HIS history of Gold among ancient and modern nations, its | geographical distribution, and its geological, mineralogical, and economical aspects, is an extension of a part of Prof. Jervis’s public lectures at the Royal Museum in Turin, on the nature and geological bearings of mineral lodes and veins, and of detrital metalliferous formations, such as the alluviums and diluviums in which the precious metals and gems are so frequently met with. The lectures were new for Turin and attracted large audiences; but the subject of Gold alone is treated of in this published portion. In writing his monograph on gold, the author has considered this metal historically, economically, and scientifically, but excluding its chemical relationship, as being so well known already. He has given a summary of the history of gold, both as extracted from its original beds, and as employed in society, from the earliest recog- nizable periods (as recorded in ‘‘Genesis”’), through the several great nations of antiquity, down to the Fall of the Roman Empire. This summary is clear and useful, and not without some new historical considerations. From the period last mentioned down to our own times the production of gold in different countries, and the modes of its occurrence, are treated of in successive chapters—under the follow- ing geographical headings—1. Japan, China, Siam, Eastern Archi- pelago, and Africa. 2. The lands discovered and opened up by Columbus, Cortez, and Pizarro in the 16th century. 3. Brazil, Uruguay, Guiana, Venezuela, Columbia, Ecuador, Chili, and Bolivia. 4, Hurope and Asiatic Russia. 5. United States of North America, with California and conterminous territories. 6. Canada, British Columbia, and Nova Scotia. 7. Australia, Tasmania, and New Zealand. Necessarily the geological details and methods of digging, washing, and mining for gold are more fully given for Hungary, Russia and Siberia, California, and Victoria, than for other localities. 228 Reviews—Dr. George J. Hinde—On Chalk Sponges. Statistics of gold-production in the second half of the 19th century in Hungary, in Russia, in California and elsewhere in the United States, in British Columbia, in Victoria, and in New South Wales, are shown in careful tables. The several kinds of gold, with specific gravity, per-centage of impurities, and other particulars and authorities, from forty world-wide localities, are given in another table. The numerous recorded nuggets of gold found in Russia, the United States, Victoria, and New South Wales, with their dates, localities, depth from the surface, weight, and carat- value, fill a large table of twelve pages. Another large table, with lithographed scales and graduated lines, exhibits the relative production of gold, from 1848 to 1880, both inclusive, in California, Australia, Russia, Siberia, British Columbia, and other countries. From the Fall of the Roman Empire we find in history little about gold and gold-mining down to the time of Marco Polo’s travels. Japan then comes into notice; and not long afterwards America and her gold-fields were visited by Europeans. In the preceding interval, gold was very scarce in Western Europe. The 17th century brought forward the Uralian and Siberian gold- deposits; and in the current half of the present century California and Australia displayed their vast gold-fields. Thus the order adopted by Chev. Jervis in the practical and economical history of gold is well considered and correct. How far the possession of gold-mines may or may not benefit a state is briefly considered in a short chapter. The author has added a polyglot vocabulary of the words used for gold by a hundred different tribes and nations. This has been enlarged from Christopher Keferstein’s ‘‘ Mineralogia Polygottica.” A full index completes this small, but very useful and trustworthy Monograph on Gold. T. R. J. Il.—Fosstz Sponge Spicutes rrom THE Urrer Onaix. Founp IN THE INTERIOR OF A SINGLE FLINT-STONE FROM HoRSTEAD IN Norrorx. By Guorer Jennines Hinpn, Ph.D., F.G.8. 8vo. pp. 83; Five Plates. (Munich, 1880.) VERY student of geology will be familiar with the sketch of the Chalk-pit at Horstead, drawn many years ago by the late Mrs. John Gunn, and of which a wood-engraving was published by Lyell, in his “ Elements of Geology,” and ‘“Student’s Elements.” At that time the Chalk displayed a considerable number of the huge and remarkable flints called potstones or ‘“ Paramoudras,” but during the progress of the working the number shown has de- creased, and latterly but few have been obtained. Now the working of the Chalk at this old pit has been given up, but many “large variously shaped nodules of flint” remain, “strewn over the floor of the pit, after the removal of the soft chalk in which they had been imbedded.” One of these, “about a foot in diameter, and more spheroidal than the generality of the potstones,” attracted the attention of Dr. Hinde during a visit he paid to the pit a little time ago; it exhibited “a central cavity, which contained a quantity of Reviews—V. Bail’s Jungle Life in India. 229 material resembling fine flour in appearance and feel, and of a creamy-white tint.” Carefully wrapping this material in a news- paper, he took away the prize, with the object of submitting it to minute investigation. The result is given in the work before us. The material when prepared for examination weighed about three or four ounces, and yielded a number of Foraminifera, and Entomo- straca, fragments of Echini, Annelida, Cirripedia, Polyzoa, Brachio- poda, Lamellibranchiata, and Fishes; and in addition the beautifully varied Sponge-spicules, which Dr. Hinde has now figured and described. These spicules, which he studied at Munich with the hearty co-operation of Prof. Zittel, he has grouped under no less than twenty-one genera, including nine new species. In a postscript he refers to the recent work of Prof. Sollas (Ann. and Mag. Nat. Hist. ser. 5, vol. vi. pp. 384-895, 437-460), wherein that author describes a number of sponge-spicules from flint-nodules of the Chalk at Trimmingham in Norfolk. Prof. Sollas has placed them under seventeen genera, of which no fewer than thirteen are new, and Dr. Hinde admits that “nearly all the forms present at Trimmingham” are included among those he describes from Horstead. We must leave the students of sponges to settle these differences. Dr. Hinde discusses the difficulties that attend the exact identification of isolated spicules “from the fact that in the skeletons of both fossil and recent sponges, very many [foreign | spicules get intermingled with the sponge.” ‘‘ Another difficulty is owing to the fact of the same form of spicule being common to several different genera of sponges,” while “in other sponges, there are six or seven different forms of spicule in the same species.” But setting aside these perplexities, Dr. Hinde has done excellent service to science in developing and illustrating the treasures of this single flint-nodule from Horstead. Although he does not attempt to discuss in detail the question of the origin of the flints in the chalk, he makes some remark upon it, and observes “that the beautifully perfect state of preservation of the various delicate fossil organisms in the interior of this flint, when compared with the nearly complete obliteration of their structures in the enveloping chalk, points to the conclusion, that the period in which the flints were formed must have been previous to that consolidation of the mass of the chalk by which the smaller fossils were mostly destroyed.” To the many interested in flint-formation, Dr. Hinde’s work offers plenty of material for careful study, while at the same time it furnishes an excellent example of what may be done by patient investigation in a somewhat restricted field. 1elh 3) \iNfc Tll.—Juneue Lire in Inpia; on THE JOURNEYS AND JOURNALS OF an Inpran Guoxoctst. By V. Baut, M.A., Geological Survey of India. S8vo. pp. 720. (London, De la Rue & Co., 1880.) UR Indian Geological Survey has now been in active progress for about a quarter of a century. As early as 1851, the late Dr. Oldham went to Calcutta for the purpose of making preliminary observations, but it was not until 1856 that he was enabled to 230 Reviews—V. Ball’s Jungle Life in India. establish a regular system of operations. Since that period the important results of this Survey have been made known to us in the “« Memoirs,” ‘‘ Records,” and ‘ Palszontologia Indica.” The geologist in this country will perhaps have but a vague idea of the work that has to be carried on in order to interpret the structure of many parts of our Indian Empire. Here a sling-bag will contain all our needful apparatus, and we can pursue our observations over every acre of land. There one needs to be accompanied by a score or more of servants, including a native doctor, an elephant, bullocks, horses, dogs, and all the materials for camp-life; and there the chief geological sections are those exhibited in the river-channels. Here the structure, arrangement, and life-history of our great groups of rocks are well ascertained, and we are now entering into almost tedious detail and controversy in the naming and correlating of sub- divisions, often but a few feet in thickness. There the majority of sections to be visited have been unseen by geological eyes, the rocks must be grouped in a large way, and the boundaries, that may often be accurately fixed in the rocky gorges cut out by the streams, must be marked across large tracts of country in accordance with the physical features, checked only by traverses here and there. In the work before us Mr. Ball has given an account of his wander- ings during a period of fourteen years, while engaged on the Indian Geological Survey. ‘The account is made up of the notes extracted in chronological order from his Journals; and they relate chiefly to the Zoology, Botany, and Antiquities, besides which are not a few descriptive of the various tribes of men. Mr. Ball is an accomplished naturalist and evidently an ardent sportsman, though, whether he would or not, the encounters with many a tiger or bear, not to men- tion other unfriendly wanderers and visitants, were to be anticipated by one engaged in such districts as Mr. Ball had to examine. Snakes -do not appear to have been so troublesome as most Huropeans would expect. The field-work of the Survey in Bengal usually commences about November and lasts until the end of April, by which time fever too frequently compels a speedy return to Calcutta. At all times, however, attacks of fever are sources of anxiety, and Mr. Ball men- tions that during two months (November and December) in the Singhbhum district, out of twenty-seven men, only three escaped illness. A good deal of his attention was bestowed upon the Coal- districts ; but as reports of all the explorations have been published, Mr. Ball here confines himself to brief and general notices of the geology. In the Bokaro Coal-field he mentions one seam 90 feet in thickness! The Ranigunj Coal-field, known as early as 1774, and worked a few years later, comprises an area of 500 square miles of coal-bearing rocks, and is known as the “black country” of India, being the largest and most important of the areas in which coal is worked. Formerly a large proportion of the coal was obtained by quarries 1 See article on the Geological Survey of India, in the Quart. Journ. Science, Oct. 1870, p. 458. Reviews—V. Baill’s Jungle Life in India, 231 and open workings, but most of the seams thus accessible have been exhausted, and regular mining is now carried on. None of the mines are of great depth, the “ pillar and stall” system is generally adopted, and there is no danger from fire- or choke-damp. Upwards of 500,000 tons of coal have been obtained in one year, but the annual production appears to be decreasing. Some remarks on the Talchir Coal-field are also given. Many notes on gold-mining, on workings for ores of iron, copper, lead, and manganese, and for diamonds, are included, as well as others upon the Metamorphic and Submetamorphic rocks, the Trap- dykes, and other geological features. Speaking of the Laterite rock seen at Midnapur, Mr. Ball notices the fact of its being un- fossiliferous, and observes that its appearance seemed to favour the view of its having been formed by the deposition of volcanic ash in water. The work itself will be read rather as a guide to the natural history of camp-life in India than as an exhaustive account of the district described (Western Bengal and the Central Provinces), for little or no attempt has been made to embody the records of others, the plan of the author being to confine himself to personal observations. Notes are also given of visits paid to the Andaman and Nicobar Islands. The work, which has assumed a formidable size, is one, however, that appeals to the naturalist rather than the general reader, who would doubtless find the scientific notes some- what tedious. As a picture of the life of our geological brethren in India, it will interest many of our readers, some of whom, having spent many months in out-of-the-way parts of this country, will not be surprised to learn that camp-life in India is ‘at times a very dull, lonely, and monotonous one.” “But (as Mr. Ball observes) the life affords various com- pensations, without which it would be unbearable. To the lover of nature there are many attractions in it. There is a great, an indescribable pleasure in being the first to take up the geological exploration of a hitherto quite unknown tract—in being the first to interpret the past history of a portion of the earth’s crust which no geologist has ever seen before.” Nevertheless, one lacks the ad- vantage, obtained in this country, of friendly recognition and criticism of his labours, and while enthusiasm in his work will carry a man through it, “ Experience has shown how manifold are the risks to be encountered, while the term of service at present. required, before a full pension can be earned, affords but a faintly- seen vision in the far-distant future of a home at home for one who has adopted the career of a geologist under the Government of India.” Some attempts have been made to instruct natives in field- geology, but these do not at present appear to have been successful. Jn conclusion we may mention that the book is handsomely “ got up,’ and is accompanied by a map, eleven vignettes, and twelve plates, including two of chipped quartzite implements, polished celts, etc. Ho By Wi 232 Reports and Proceedings— IV.—Aw Axzstract or tHE Grotocy or Inpia. By P. M. Duwoan, M.B. (Lond.), F.R.S., F.G.S. Third Edition. (London, 1881.) HIS work is chiefly intended as a text-book for the students of the geological class at the Indian Hngineering College, but the geologist and general reader will find it also a clear and concise abstract of the present established facts in Indian geology, and a useful summary of the larger and more detailed Manual by Messrs. Medlicott and Blanford, noticed in this Magazine (February and March, 1880). The present edition has been carefully revised by Prof. Duncan, and contains much additional matter and some alterations, necessitated by the publication of the official Manual above referred to, and from which excellent book the author fairly acknowledges many pages of his abstract are derived. India may be naturally divided into three regions, the Peninsular, Extra- Peninsular, and Indo-Gangetic; the distinctness in the geological structure and physical features of the two former is very marked, the latter is a vast alluvial plain, due to a depression which has been more or less filled up with the alluvia of the rivers of the other regions flowing into it. The geology of these three regions is described in a series of chapters commencing with the recent deposits, and proceeding in descending order with the Tertiary, Cretaceous, Jurassic and underlying series, followed by descriptions of the Peninsular Coal-fields, their fauna and flora, and of the Azoic and Metamorphic rocks of the two regions. The work will be a useful guide to the general facts of Indian geology, as regards the nature, character, and arrangement of the crystalline, metamorphic, and sedimentary rocks of India. Besides classified lists of the formations of Peninsular and Hxtra-Peninsular India, a table is given showing the equivalents (homotaxially considered) of the formations compared with those of Europe. J. M. IS aI OisyayS) JAN aD) aSiyO Aa IA AD ALIN TS Sis ae) Fare INTERNATIONAL GEOLOGICAL CoNnGRESS. N the Gron. Mac. for December, 1876 (Decade II. Vol. III. p- 573), attention was drawn to certain proposals made for the holding of an International Geological Congress at Paris in 1878, whose purpose should be to consider the many obscure points in geological classification and nomenclature. The Congress was duly arranged, opened, and carried on for six days, under the Presidency of Prof. Hébert. At the concluding sitting it was resolved that a Second Session should be opened at Bologna, September 29, 1881. His Majesty the King of Italy has consented to be Patron of the Congress, and Signor Q. Sella has been nominated President. Two principal subjects were proposed by the Congress of Paris for discussion, and each was referred to an International Commission named by the Congress; they were as follows :— 1. Geological Cartography: to consider the possibility of the adoption of a common system of signs and colours. International Geological Congress at Bologna. 233 2. The Unification of Geological Nomenclature : to consider all matters relating to stratigraphical classification and nomenclature, and so far involving an inquiry into the value and significance of petrological and paleontological characters. Prof. T. M‘K. Hughes was appointed the Commissioner on the Unification of Geological Nomenclature for Great Britain, and he was requested to organize a Committee to report upon the different Geological subdivisions, and on the various details bearing upon the questions of classification and nomenclature. Acting in conjunction with Prof. Prestwich, he has accordingly formed a Committee which has met on several occasions in London. The matters at present discussed have been the definition of the terms :—System, Formation, Terrane, Deposit, Bed, Layer, Rock, Group, Series, Zone, Horizon, Period, Age, Epoch, Era, Time, Cycle, Date, etc. The organization of Sub-committees has also been carried on, and one or more Reporters have been attached to each (after the plan adopted by Committees of the British Association), to collect the information from the several members composing it, and to draw up the Reports. The following Reporters were appointed :—Com- mittee to consider Recent and Tertiary, J. Starkie Gardner and H. B. Woodward; Cretaceous, W. Topley and A. J. Jukes-Browne ; Jurassic, W. H. Hudleston and the Rev. J. F. Blake; Trias and Permian, C. E. De Rance and the Rev. A. Irving; Carboniferous, Devonian, and Old Red Sandstone, G. H. Morton and A. Strahan ; Silurian, Cambrian and Pre-Cambrian, C. Lapworth and J. E. Marr; Petrology and Mineral Veins, H. Bauerman and T. Davies. The duty of the Sub-committees will be (1) To draw up a list of the names now in use for each formation, and for its subdivisions ; (2) To ascertain the true significance of such names or terms, giving reference to the authors by whom they were used in the first instance, or subsequently with a modified meaning; (3) To investigate the synonymy of the names, firstly in regard to the British rocks, and afterwards in regard to equivalent beds in foreign countries; (4) To offer suggestions for the unification of the Nomenclature. Through the liberality of His Majesty the King of Italy, the Italian committee of organization are able to offer a prize of 5000 francs for the best suggestion for an international scale of colours and conventional signs practically applicable to geological maps and sections, including those of small scale. The index of colours and signs should be accompanied by maps representing regions of varied geological structure, and by an explanatory memoir in the French language. The documents should be marked with a motto, which should be placed on the outside of an envelope containing the name of the author, which will not be opened until the Congress, when the name of the successful competitor will be made known. The index and accompanying papers should be sent in to Prof. J. Capellini, Director of the Museum at Bologna, by the end of May. The award will be made by a jury of five chosen from the presidents of sub-commissions. Should no index be thought worthy of the grand prize, the best will receive a gold medal of the value of 1000 234 Reports and Proceedings— francs, while the two next will be given medals of silver and bronze of similar shape.? GrotocicaL Society or Lonpon. I.—March 23, 1881.—Robert Etheridge, Esq., F.R.S., President, in the Chair.—The following communications were read :— 1. “The Upper Greensands and Chloritic Marl of the Isle of Wight.” By C. Parkinson, Esq., F.G.S. In this paper the author described the Upper Greensand as ex- posed at St. Lawrence and along the Undercliff. At the base of the St. Lawrence cliff there are hard bands of blue chert, from which astaciform Crustacea have been obtained ; and quite recently, in a large boulder of the same material lying on the beach, there were found the remains of a Chelonian, referred by Prof. Owen to the family Paludinosa, and named by him Plastremys lata. The presence of these freshwater organisms was thought to imply a connexion with the Wealden continent. The chert-bed, 2 feet thick, was regarded by the author as marking the boundary between the Gault and the Greensand. Above it the author described 56 feet of compact red and yellow sands, of which the first 20 feet are un-fossiliferous, the upper 32 feet show traces of organic remains; between them there is a fossiliferous zone 4 feet in thickness, containing Ammonites inflatus, A. auritus, and species of Panopea, Cucullea, Arca, and Trigonia, and immediately below this aseparate band containing an undetermined species of Ammonite. These sands are followed by 88 feet of alternate beds of hard chert and coarse greensands, having at the bottom 6 feet of inferior building-stone, surmounted by 5 feet of freestone. The latter con- tains Ammonites rostratus, and the cherts various fossils, chiefly bivalves. Clathraria Lyelli also occurs at this level. Above the greensands come 6 feet of chloritic marl :—the upper 34 feet fossiliferous, with a base of hard phosphatic nodules containing crushed specimens of Pecten asper ; the lower 24 feet compact, with darker grains and few fossils. .The author compared the sections of this series given by Capt. Ibbetson and Dr. Barrois; his own views closely correspond with those of the latter writer. 2. “On the Flow of an Ice-sheet, and its Connexion with Glacial Phenomena.” By Clement Reid, Esq., F.G.S. The author considers that the Boulder-clays have been formed beneath an ice-sheet, and consequently there must have been formerly a huge mass of ice, which would have to flow 500 miles on a nearly level surface, and then to ascend a gentle slope for nearly another 100 miles. He does not think a great piling up of the ice at the north pole can be assumed to account for this motion. This he explains by the gradual passage of the earth’s heat through the mass of ice, raising the temperature of the whole instead of lique- fying the surface-layer. As the heat passes upwards, it raises the 1 This last paragraph we extract from an article in ‘‘ Nature,’”’ March 31st, 1881, by Mr. De Rance. Geological Society of London. 235 temperature of a particular layer, causes it to expand, and so to put a strain upon the layer above, and then to rupture it. The broken part spreads out, reunites by regelation, and then receiving the heat from the layer below again expands and ruptures the layer next above. Thus the movement is from the base upwards, rather than from the surface downwards. The author estimates that the ice-sheet in Norfolk was only about 400 feet thick, because Boulder-clay does not appear above that level, but only coarse Boulder-clay; in North Yorkshire it extends up to about 900 feet. The author considers that the shell-beds of Moel Tryfaen were not deposited under water, but thrust up-hill by this advancing ice-sheet. 3. “Soil-cap Motion.” By R. W. Coppinger, Esq. Communicated by the President. The author described numerous cases in Patagonia where the stumps, etc., of trees are to be seen in the marginal waters of the sea and of lakes. These, together with stones and rocks, sometimes simulating perched blocks, he considers to have been brought down by the motion of the soil-cap—-a thick spongy mass resting upon rock often worn smooth by the action of ice, and so sliding down the more easily under the influence of vegetation. The appearances are not unlike those due to subsidence; but he points out that all the evidence is in favour of recent upheaval, instead of subsidence. II.— April 6, 1881.—J. W. Hulke, Esq., F.R.S., Vice-President, in the Chair.—The following communications were read :— 1. “The Microscopic Characters of the Vitreous Rocks of Montana, US.” By F. Rutley, Esq., F.G.S. With an Appendix by James Kecles, Esq., F.G.S. The specimens described were collected by Mr. J. Eccles, F.G.S. They consist of various obsidians and rhyolites, some of them porphyritic or spherulitic, which appear to throw some light on the epoch at which these structures have been set up. In a black porphyritic obsidian is a crystal which the author believed to be olivine. Zirkel has already noticed the occurrence of this mineral in a trachyte. The structure of some of the above indicates that it is extremely difficult to draw hard and fast lines between trachytic rhyolites and felstones. A tuff containing fragments of a rhyolite, some perlitic, was also described. The spaces included within the boundary of some of these perlitic cracks exhibit depolarization and sometimes interference-crosses. The author considered these to be the result of strain in contraction, and connected with incipient crystallization. Andesites, from two localities in the northern part of the Yellow- stone district, were also described. In an appendix Mr. Eccles briefly described the geology of the region from which the above specimens were collected, referring for greater detail to the memoirs of Dr. Hayden and his fellow-workers. In the Yellowstone-Park region trachyte and obsidian (the latter 2036 Reports and Proceedings— Geological Society of London. being the upper) form an irregular plateau, resting on rocks of Carboniferous age; no vents were observed ; but Mount Washburne, a few miles distant, is a broken-down volcanic cone, from which both trachyte- and basalt-flows (the latter the newer) have proceeded. 2. “On the Microscopic Structure of Devitrified Rocks from Ru Snowdon, and Skomer Island.” By F. Rutley, Esq., F.G.8 The first specimen described was found about a quarter of a mile from Beddgelert, on the Capel Curig road. Hxamined microscopi- cally, it sawed traces of perlitic Sean. with small spherulites, both isolated and in bands, not exhibiting radial structure, but apparently composed of very minute chlorite and a garnet, probably spessartine. Hence the rock must be a devitrified obsidian or pitchstone. The second specimen is a banded greenish-grey “ fel- stone,” at Clogwyn du’r Arddu, of Bala age, which also has probably been vitreous. The third specimen, from near Pont y Gromlech, is a schistose felsitic rock. This was compared microscopically with an obsidian from Hungary and a rhyolite from Gardiner’s River. (N. America), and was shown to have been probably once a glassy rock. In conclusion the author discussed the limits of the terms felstone, rhyolite, trachyte, and obsidian. An appendix was added upon the microscopic characters of some rocks from Skomer Island, off the coast of Pembrokeshire. These were shown to be devitrified obsidians, some of them exhibiting spherulitic and perlitic structures. A trachytic rock and a basalt from the same locality were also described. 3. “The Date of the last Change of Level in Lancashire.” By T. Mellard Reade, Esq., C.E., F.G.S. The author described some observations made by him at Blundell- sands, on the coast of Lancashire, near Liverpool, according to which, judging from the position of high-water mark, the land had gained considerably upon the sea between 1666 and 1874. At one end of a length of 850 yards, spring-tide high-water mark had receded 15 yards, and at the other end 5 yards. The author estimated that the deposit of sand that had accumulated in 8 years amounted to an average of 10 yards wide and 2 yards deep. Allowing a further depth of 1 yard for sand that may have been blown over the top, he finds 10,500 cubic yards as the quantity of sand deposited in 8 years on a shore-frontage of 3850 yards, or 3-75 cubic yards per yard of frontage per annum. Applying this unit of measurement to the 16 miles of coast forming the western boundary of the deposit, he gets 105,600 cubic yards as the quantity of sand annually moved ; 22 square miles of sand, 12 feet thick, give 272,588,800 cubic yards of sand accumulated, which, divided by the annual quantity, will give 2580 years as the age of the whole deposit of blown sand. The author adduced other evidence in support of his view, and concluded that if the last change of level in South-west Lancashire was a downward one, it could not have taken place within 2500 years. Correspondence—Dr. C. Callaway—Rev. O. Fisher. 237 COE Si @ iNet INS zeae THE PRE-CAMBRIAN ROCKS OF ST. DAVIDS AND OF BOHEMIA. Sir,—I cannot find that the letter of Dr. Hicks in your last issue materially strengthens the proof for the Dimetian age of the eneissic series which underlies the Bohemian Pebidian. Dr. Hicks maintains that the St. Davids Dimetian is a true gneiss. I cannot of course say that the rock in the few sections which I did not see is not foliated; but I saw no true foliation in the principal localities named in his papers, and I cannot discover anything about foliation in the microscopic descriptions of Mr. T. Davies, Prof. Bonney, and Mr. Tawney. It is at any rate certain that if these rocks are schists, their foliated structure is of the obscurest possible character, and quite unlike that of the true gneisses. I quite agree with Dr. Hicks that we are not to expect “absolute identity,’ but I deny that there is even a “ general resemblance ” between the Dimetian of St. Davids and the gneissic rocks of Bohemia, so far as we can judge from Mr. Marr’s descriptions. Nor do I think that a similarity of the conditions of deposit, even if proved, goes for much. I presume that most arenaceous rocks, from the Tertiary downwards, were laid down in comparatively shallow water. That the Bohemian gneiss unconformably underlies the Pebidian, simply proves that it is pre-Pebidian. I do not deny its Dimetian age: indeed, I think it highly probably that Mr. Marr is right; but, as we do not yet know how many gneissic series lie below the _ Cambrian, I demur to the assumption that any Archean gneiss group which is not Lewisian must be Dimetian. Any resemblance to the newer gneiss of the Highlands can have no decisive value in our present uncertainty of the age of that formation. These Archean groups are a very complicated study, and more haste may sometimes prove to be the worse speed. ‘The researches of Dr. Hicks have done much towards unravelling the Archean mystery, but we must work along our clues with great caution, else we shall become the sport of the Philistines who would condemn us to grind in the prison-house of an eternal Siluria. C. CanLaway. WELLINGTON, SALoP, March 5th, 1881. OBLIQUE AND ORTHOGONAL SECTIONS. Str,—In my short notice about the section of a folded plane there is an error which Mr. Day has not pointed out. I did not expect that what I had written would have attracted attention; but since it has done so, I may ask to be allowed to say, in the sixth line from the bottom of p. 21, dele “=0,” and in the fifth, for “0” read «« # A B=6 suppose.” I cannot exactly see that Mr. Day’s proof gives my second equation, because his a, 6, and ¢ do not appear to be the same angles as in my demonstration. The method of the shadow is ingenious and of course correct. Haruton, 4th March, 1881. QO. Fisuxr. 238 Oss apASe ae —_— JOHN J. BIGSBY, M.D., F.R.S., F.G.S., F.R.G.S. Born Ave. 147TH, 1792; Drep Fs. 107TH, 1881. Dr. J. J. Braspy was the son of J. Bigsby, Esq., M.D., Edinburgh. He was born at Nottingham, on the 14th August, 1792, and early followed the career of his father by entering the Medical Profession, and shortly after taking his degree, he was appointed about 1818 as Medical Officer toa German Rifle Regiment in the English Service and ordered to Canada. Soon after his arrival he was sent by the Governor to Hawkesbury Settlement, where there had been an out- break of typhus fever. In the following year the more agreeable task was assigned to him of travelling through Upper Canada to report upon its Geology. A part of the collections he then made are still pre- served in the British Museum, not the least interesting of which are the curious siphuncles of Huronia Bigsbyi, from Drummond's Island, Lake Huron. About the year 1822 he was appointed British Secretary and Medical Officer to the Canadian Boundary Commission. In 1828 he was elected a Fellow of the Geological Society of London, to whose Transactions he had already been a contributor. Dr. Bigsby returned to England about 1827, and commenced to practise as a medical man at Newark. In 1846 he came to reside in the metropolis, and from that date identified himself with most of the scientific societies in London. In 1850 he published the account of his experience of life and travel in North America, under the title of ‘Shoe and Canoe.” His first scientific paper appeared in Silliman’s American Journal in 1820, and he contributed altogether about twenty-seven papers to learned societies in London and elsewhere. His most important . scientific work appeared in 1868, entitled “Thesaurus Siluricus,”’ being a list of all the fossils which occur in the Silurian formation throughout the world. He was elected a Fellow of the Royal Society in the following year, and was awarded the Murchison Medal in 1874 by the Council of the Geological Society. In 1878 he published his second catalogue, entitled “'Thesaurus Devonico-Carboniferus,” and at the time of his death had far ad- vanced towards the completion of his third volume, the < ‘Thesaurus Permianus.” In 1876 he requested the Geological Society to accept, in trust, a sum of money to provide a medal to be called the “ Bigsby Medal,” and to be awarded biennially to some geologist not more than forty-five years of age of any nationality; Prof. Marsh, Prof. Cope, and Dr. Barrois having been up to this time the three recipients. Dr. Bigsby died at his residence, 89, Gloucester Place, Portman Square, at the good old age of 89 years. PROFESSOR JAMES TENNANT, F.G.S., F.C.S., Born 1808; Dizp Frpruary 23rp, 1881. Durine the earlier part of the present century the science of Mineralogy had no more claim to be considered one of the exact sciences than has Geology at the present day. To be able to Obituary—Prof. James Tennant. 239 identify minerals “at sight,” and to test them by their hardness, lustre, form, and weight, represented the common extent of a collec- tor’s acquirements. But few understood the use of a goniometer, and not many could use the blowpipe, or correctly make an analysis of a mineral in this country. It was young James Tennant’s lot to come to London at an early age, and enter the service of Mr. Mawe, the well-known Mineralogist, whose shop was a centre of resort for men of science. The stock-in-trade consisted of shells, minerals, marbles, etc., most of which Mr. Mawe obtained during his frequent travels. Here Tennant gained his first acquaintance with minerals. The classes of the Mechanics’ Institution which he joined, and attendance on Faraday’s lectures at the Royal Institution, improved his educa- tion, and enlarged his scientific knowledge of the specimens in which his master dealt. At Mr. Mawe’s death, the management of the business devolved upon Tennant, who shortly after succeeded to it as proprietor. He derived much advantage from the friendship of Sir Everard Home, whose knowledge of crystals enabled him to impart much valuable information to Tennant. When King’s College opened in the Strand, the Council desired a teacher in Mineralogy, and applied to Faraday for his nomination of a fit person; his recommendation was in favour of Mr. Tennant, who shortly after his appointment received the title of ‘ Professor of Mineralogy.” The new position opened a wider field of usefulness and of interesting study. His after-life was devoted to the diffusion of knowledge relating to mineralogy and geology, and many of the students who attended his lectures proved that he had not taught in vain by turning out to be useful collectors and observers of minerals abroad. He was one of the strong promoters and believers in the discoveries of Diamonds in South Africa, at a time when others denied their genuineness. Professor Tennant was a very ardent advocate of technical educa- tion, and having seen the valuable application of the lathe in cutting both diamonds and other valuable stones and marbles, he induced the Turners’ Company to promote the advancement of turning, by offering prizes annually for specimens in all branches of the turner’s art. Great credit is due to Prof. Tennant for the revival of this branch of technical education as applied to ornamental work of all kinds and materials. He was one of the founders of the Geologists’ Association, of which body he was formerly President. He was also for several years a member of the Council of the Geological Society of London. SIR PHILIP DE MALPAS GREY-EGERTON, BART., M.P., F.R.S., F.G.S., OF OULTON PARK, TARPORLEY, CHESHIRE, Born Noy. 137H, 1806; Diep Aprit dru, 1881. AnotHER distinguished name has been erased by death from the list of Fellows of the Geological Society. Sir Philip Hgerton was the eldest son of the Rev. Sir Philip Grey-Egerton, by his wife Rebecca, youngest daughter of the late Josias Dupré, Esq., of Wilton 240 Obituary—Sir P. de M. Grey- Egerton. Park, Bucks; he was educated at Eton and Christ Church, Oxford, graduating B.A. in 1828. Having studied geology under Conybeare and Buckland, together with the Earl of Enniskillen, he made a lengthened geological tour with that nobleman through Germany, Switzerland, and Italy. About this time he became acquainted with Professor L. Agassiz, at Neufchatel, and commenced the forma- tion of a grand collection of Fossil Fishes, both from British and Foreign localities. A large number of the types of Agassiz’s Mono- graph on the “ Fossil Fishes of the Old Red Sandstone” (published in 1844) are to be found in the Enniskillen and Egerton Collections, as also of specimens described and figured in the Decades and Memoirs of the Geological Survey, the Quart. Journ. Geol. Soc., the GeroLtocicaAL Magazine, etc. He entered Parliament in 1850 as Member for Chester, and he afterwards represented the Southern and Western Divisions of Cheshire since 1835. He was senior elected Trustee of the British Museum, and one of the Original Trustees of the British Association, and of the Royal College of Surgeons of London, and a Member of the Senate of the University of London. He was elected a Fellow of the Geological Society in 1829, and of the Royal Society in 1831, to the Proceedings of both which he has been a frequent contributor. Having been almost always a Member of the Council of the former Society, an opportunity only occurred to award him the Wollaston Medal in 1873. The first Kingsley Medal was also presented to him in 1878, by the Chester Natural History Society, in recognition of his valuable services in promoting the objects of that Society. During the long period which he served as a Member of Parliament, although not distinguished in debate, he was never- theless one of the hardest workers in Committees of the House, and whether as a naturalist, or antiquary, a field-sportsman, or country gentleman, he was always thoroughly in earnest in all he undertook. His career was an eminently useful and practical one, and his loss in the world of science, as well as of politics, will be keenly felt; but most severely by the circle of his most intimate friends who had grown to know and value him for his private character, and the noble example he set as a thorough and upright Hnglish gentleman. He worthily did honour to the motto of his ancient house :— ‘JT trust not in arms but in virtue.’’ Man S Czee ae eAaN ee @miS- A Dexp Coau-Mine.—It is interesting to record a triumph of engineering skill and perseverance. On Saturday, March Sth, at the Ashton Moss Colliery, in Lancashire, the main seam of coal was cut at the depth of 2691 feet. This is the deepest pit in the United Kingdom, Rose Bridge Colliery, which was the deepest previous to this sinking, being only 2460 feet. The temperature in the Ashton Moss Colliery at 860 yards was 78° Fahr.— Atheneum, March 19. THE GEOLOGICAL MAGAZINE. NEW SSERIESHs DECADE slit ) VOL. wwii No. VI—JUNE, 1881. Oe Ses Aaa) Abtee sake @ tees SS. ——@__ J.—SussipENCE AND HLEVATION, AND ON THE PERMANENCE OF OcEANS. By J. SrarkiE GARDNER, F.G.S. HE theory of permanent Continents and Oceanic basins, opposed as it is to the general teaching of text-books, seems to have given rise to comparatively little discussion. In the latest edition, for instance. of Tivell’s Princinles. we read: “Tt is nat taa munch Norrce.—The Chromo-Lithographic Plate intended to accompany Mr. J. S. Gardner’s paper, not being ready in time to appear in this month’s Magazine, will be issued in our next number, for July.—Eprr. Geox. Mac. weeny ee UWU WH ULUULLY e gratuitous, and entirely opposed to all the evidences at our command,” the supposition that temperate Europe and temperate America, Australia and South America, have ever been connected, except by way of the Arctic or Antarctic Circles, and that—lands now separated by seas of more than 1000 fathoms depth have ever been united. Mr. Wallace, it must be admitted, has succeeded in explaining the chief features of existing life distribution, without bridging the Atlantic or the Pacific, except towards the Poles, yet I cannot help thinking that some of the facts might perhaps be more easily explained by admitting the former existence of the connexion between the coast of Chili and Polynesia and Great Britain and Florida, shadowed by the sub-marine banks which stretch between them. Nothing is urged that renders these more direct connexions impossible, and no physical reason is advanced why the floor of the Ocean should not be upheaved from any depth. The route by which the floras of South America and Australia are supposed to have mingled is beset by almost insurmountable obstacles, and the apparently sudden arrival of a number of sub-tropical American plants in our Hocenes, necessitates a connexion more to the south DECADE II.—VOL. VIII.—NO. VI. 16 240 Obituary—Sir P. de M. Grey- Egerton. Park, Bucks; he was educated at Eton and Christ Church, Oxford, graduating B.A. in 1828. Having studied geology under Conybeare and Buckland, together with the Earl of Enniskillen, he made a lengthened geological tour with that nobleman through Germany, Switzerland, and Italy. About this time he became acquainted with Professor L. Agassiz, at Neufchatel, and commenced the forma- tion of a grand collection of Fossil Fishes, both from British and Foreign localities. A large number of the types of Agassiz’s Mono- graph on the “ Fossil Fishes of the Old Red Sandstone ” (published in 1844) are to be found in the Enniskillen and Egerton Collections, as also of specimens described and figured in “the Decades and Memoirs of the Geological Survey, the Quart. Journ. Geol. Soc., the GrEoLtocgicaL MaGazing, etc. He entered Parliament in 1830 as Member for Chester, and he afterwards represented the Southern and Western Divisions of Cheshire since 1835. He was senior elected Trustee of the British Mnsenm and ona =f 5) whether as a naturalist, or antiquary, a field-sportsman, or country gentleman, he was always thoroughly in earnest in all he undertook. His career was an eminently useful and practical one, and his loss in the world of science, as well as of politics, will be keenly felt; but most severely by the circle of his most intimate friends who had grown to know and value him for his private character, and the noble example he set as a thorough and upright Hnglish gentleman. He worthily did honour to the motto of his ancient house :— “‘T trust not in arms but in virtue.”’ IVES Care ASN EE @ US - A Devp Coat-Minz.—It is interesting to record a triumph of engineering skill and perseverance. On Saturday, March oth, at the Ashton Moss Colliery, in Lancashire, the main seam of coal was cut at the depth of 2691 feet. This is the deepest pit in the United Kingdom, Rose Bridge Colliery, which was the deepest previous to this “sinking, being only 2460 feet. The temperature in the Ashton Moss Colliery at S60 yards was 78° Fahr.— Atheneum, March 19. THE GEOLOGICAL MAGAZINE. NEW) SERIES) (DECADE I VOLES) MII No. VI—JUNE, 1881. (usta SMILING /Naby 9S ahah Own wsHi Se — I.—SuBsIDENCE AND ELEVATION, AND ON THE PERMANENCE OF OCEANS. By J. Srarkre Garpner, F.G.S. HE theory of permanent Continents and Oceanic basins, opposed as it is to the general teaching of text-books, seems to have given rise to comparatively little discussion. In the latest edition, for instance, of Lyell’s Principles, we read: “It is not too much to say that every spot which is now dry land has been sea at some former period, and every part of the space now covered by the deepest ocean has been land.” The new theory has been upheld chiefly by Sir Wyville Thomson, Prof. Geikie and Mr. Wallace. The latter especially has collected every kind of evidence together that seems to support it in his latest, and most admirable work, “Tsland Life.” By a process of reasoning, supported by a large array of facts of different kinds, he arrives at the conclusion that the distribution of life upon the land, as we now see it, has been accomplished without the aid of important changes in the relative — positions of continents and seas. Yet if we accept his views, we must believe that Asia and Africa, Madagascar and Africa, New Zealand and Australia, Europe and America, have been united at some period not remote geologically, and that seas to the depth of 1000 fathoms have been bridged over; but we must treat as “utterly gratuitous, and entirely opposed to all the evidences at our command,” the supposition that temperate Hurope and temperate America, Australia and South America, have ever been connected, except by way of the Arctic or Antarctic Circles, and that—lands now separated by seas of more than 1000 fathoms depth have ever been united. Mr. Wallace, it must be admitted, has succeeded in explaining the chief features of existing life distribution, without bridging the Atlantic or the Pacific, except towards the Poles, yet I cannot help thinking that some of the facts might perhaps be more easily explained by admitting the former existence of the connexion between the coast of Chili and Polynesia and Great Britain and Florida, shadowed by the sub-marine banks which stretch between them. Nothing is urged that renders these more direct connexions impossible, and no physical reason is advanced why the floor of the Ocean should not be upheaved from any depth. ‘The route by which the floras of South America and Australia are supposed to have mingled is beset by almost insurmountable obstacles, and the apparently sudden arrival of a number of sub-tropical American plants in our Hocenes, necessitates a connexion more to the south DECADE II.—yOL. VIII.—NO. VI. 16 242 J. Starkie Gardner—Permanence of Continents and Oceans. than the present 1000-fathom line. Again, the geological evidence, as I have pointed out in the Popular Science Review, is far from being so favourable to Mr. Wallace’s view, as he supposed. Apart from the regions of less depth, which I think may have been more or less land during the Tertiary period, there is some reason to believe in the general permanence of the Oceans over the areas where they are now deepest. It is perfectly certain that the causes which lead to elevation and subsidence must react upon each other, and if these were exclusively the result of shrinkage, there would be no reason why the sea-bottom at the greatest depths should not have come to the surface. With a layer fluid under a given pressure, resting upon solid, and sensitive to any increase or decrease of pressure, the chief effects of elevation and subsidence could be explained.' Many persons have been struck with the almost universal tendency to depression exhibited in areas occupied by deltas and estuaries. ‘This fact has frequently been alluded to in the Gxono- ercaAL Magazine, and elsewhere, and has been most clearly ex- pressed by Dr. Charles Ricketts,? that this subsidence is directly produced by the accumulation of sediment. However insignificant, some cause must initiate movement in the earth’s crust, and as an incautious shout may bring down an avalanche, so even an accumu- lation of a few feet of clay over several square miles may create a disturbing re-adjustment, and eventually lead to a downward tendency. Supposing a sediment, 50 feet in depth and entirely submerged, to have displaced an equivalent of sea-water, we should have an in- ereased pressure per square yard (taking the mean density of the materials composing a delta at 170 lbs. per cubic foot) of rather more than 25,000 lbs., or about 34,845,000 tons per square mile. When we see that deltas have accumulated to depths of perhaps even beyond 1000 feet, and extend, as in the Mississippi, to 19,450 square miles, it is easy to realize how vast a force is present.’ The hypothesis that added weight leads to subsidence may also to some extent be sustained by the continuous depression of Coral Islands. Great accumulations of ice in the Glacial period seem to have been accompanied by subsidence, and even Greenland at the present day may be sinking under its ice-cap. To apply the theory to a wider field, we frequently observe signs of subsidence on the sea-coast. We meet on every shore with vestiges of submerged land vegetation and with traditions of sub- mergence since historic times. Though raised beaches exist, it should be remembered that these are local and always rendered con- spicuous, while depressed beaches seldom or never attract attention. Forests have been depressed beneath the sea-level and no trace of them has ever come to light, except at low spring-tides and in " According to Lyell, all known rocks would fuse under a pressure of from 20 to 25 miles, whilst greater pressure would reconvert them to solids with a high specific gravity. ~ 2 Grot, Mae. 1872, Vol. IX. p. 119. 3 See Permanence of Continents, J. S. Gardner, Popular Science Review, 1881, p. 125. J. Starkie Gardner—Permanence of Continents and Oceans. 243 exceptionally rough weather. We have generally to trust to founda- tions and well-borings near the coast, and these, as far as I am acquainted with them, have invariably shown that our sea-shores are steadily sinking. If this were not so, our land would be surrounded by extensive shoals of uniform depth, for the whole of the sediments from the wasting of the shore are thrown down almost entirely upon a belt 80 miles wide. The moving power of waves is not felt to a greater depth than forty feet, tides appear to have no permanent action in removing sediment, and shore currents of sufficient power are local and merely cut channel-ways. The rapidity with which silt accumulates may be seen by the manner in which wrecks become lost to view, and in the discolouration of the sea during rough weather pro- duced by particles from the shore held in suspension. This shore deposit does not find its way to the depths of the ocean, and if its constant accumulation is not balanced by subsidence, what becomes of it?! A glance moreover at any stratified rock composed of littoral deposits, will show from its thickness, which often exceeds the depth of water in which it is supposed to have been deposited, that it must have been deposited in a subsiding area. No conclusion but this can be drawn in working through our Hocenes, and it is suffi- ciently obvious that no thick littoral deposit can take place in an area of elevation. If the theory that sedimentation directly causes subsidence is pushed still further, we discover a physical reason for the per- manence of Ocean basins. If permanent, deposition must have been continuous since Paleozoic times, and would to a large extent have filled in even the very greatest depths of the ocean, unless compensated by constant and gradual depression. The mean of four experiments made on the ‘Challenger ” Expedition, deter- mined the quantity of carbonate of lime in the form of living organisms in the surface waters to be 2°545 grammes, so that if these animals were equally abundant in all depths down to 100 fathoms, it would give 16 tons of carbonate of lime to each square mile of 100 fathoms depth.? There is no reason, however, why organisms contributory to sediment should not extend to, and even become more abundant towards the bottom. In the absence of knowledge as to the duration of life in such minute marine organisms as Globigerina, we are without data for estimating the rate of depo- sition in deep seas. Although at great depths shells of Foramini- fera are reduced to bicarbonate, this does not seem to result in loss of material, for the samples of deep sea-bottom that have been dredged, and our own Chalk formation, tend to show that the supply of lime is not kept up to any extent by the dissolution of dead organisms. The continuously increasing weight of sediment and of water 1 Sir J. Herschel was of opinion that the weight of sediment displaced by the sea produced elevation and depression along coast-lines (Phys. Geogr. p. 116). 2 This would deposit, if replenished annually, one inch of sediment in 8,000 years. Tf life extended equally to 2,000 fathoms, one inch would be produced in 400 years. Tf 12 generations were produced per annum, one inch would result in 33 years, and this might be more than doubled by the decay of lite at the bottom. 244 J. Starkie Gardner—Permanence of Continents and Oceans. must exercise enormous pressure, tending to make the greatest depths of the sea permanent, and to continually elevate lines of least resistance into ridges or banks, resulting, where the state of tension is extreme, in isolated volcanic outbursts. The lines of absolute least resistance would probably, however, more generally coincide with sea-margins, because these would be the nearest lines to the area of depression, free from accumulating sediment. Upon coasts, there- fore, while we might expect, and actually find, a tendency to local depression, owing, as I suggest, to littoral sedimentation ; at a few miles inland there should be found a far more important and preponderating tendency to elevation. That such a tendency has really existed is apparent from the positions of the chief mountain chains. Considering the very different distribution of seas which prevailed during the periods of elevation of some mountain chains, and the complicated forces at work, it is remarkable how the chief mountains of the world follow the existing, or recently existing coast-lines. In Europe we have the Icelandic mountains on its southern shores, and formed probably when Iceland extended some way north. The Norwegian chain, and the Welsh and Irish mountains follow the coast-line, and were chiefly formed perhaps, when England and Scotland were united to the Continent. The Sierra Nevada, the Cantabrian mountains and the Pyrenees; the Corsican, Sardinian and Sicilian mountains, the Apennines, Maritime and Dinaric Alps, and the Alps them- selves, were formed when Eocene seas washed their bases. In Asia we find the Mediterranean, the Red Sea, the Gulf of Aden, the Persian Gulf, and the south shore of the Caspian, margined by mountains. Both sea-boards of Hindustan are followed a little way inland by the Hastern and Western Ghauts, and the Hima- layas skirted the sea at the time of their formation. The Malay peninsula is a mountain ridge, and mountains follow the sinuosities of the Hastern coast of Asia from Singapore to Behring’s Straits. Eastern and Western Australia also have their coast ranges. In Northern Africa there are almost continuous mountains from the south of Morocco to Suez. The Kong mountains follow the coast of Liberia to the Slave Coast. The Cape mountains stretch north at least to Mozambique, and hills seem to line the coast from Zanzibar and meet the northern range at Suez. In America a magnificent range follows the Western coast from Alaska to Cape Horn, and on the east are the Alleghany and Rio de Janeiro mountains. Unless we believe that the principal chains of mountains follow present or past coast-lines by a mere coincidence, we must recognize that some definite law is at work. But even more conclusive evidence is derived from the position of active volcanos, for these prove that the fluid layer is actually forced nearest to the surface along coast-lines. The Pacific is almost encircled by a marvellous chain of volcanic vents; and earthquake regions are also generally in proximity to the sea. If the sedimentation going on annually at the bottom of the ocean really produces depression, that is, displacement of the fluid J. FE. Marr—Cambrian and Silurian Rocks. 24d layer, it must force up mountain chains along lines of least resistance. The sustained pressure would continually keep fresh layers of the solid interior or of its own material at the liquefying point, and press them out in turn—imperceptibly deepening the ocean basins where they are deepest and raising the shallower parts to higher levels, thereby slowly lessening the surface area of seas. On the other hand, the dry land would extend in a corresponding degree, and its surface become more diversified, for new mountain chains would perhaps in succeeding ages have a tendency to reach greater elevations. Geology itself supports this hypothesis. The records of the Paleozoic rocks point to a com- parative uniformity in the earth’s surface in remote times, there being neither evidence of great depths in the sea, nor of mountainous elevations in the land, and paleontological evidence shows these con- ditions to have been progressively modified until the present day. If mountain chains and volcanic outbursts were caused only by the cooling of the earth, we should find, instead of the uniformly shallow sea of the older Palzeozoic rocks—and the almost uniformly level land of the Carboniferous —evidence of even greater inequalities of surface than now exist. While therefore upon this theory the greatest depths of the ocean may always have been permanent, the banks and ridges of less depth with islands occasionally rising to the surface, and crossing the Atlantic and Pacific, must either be rising or sinking. If they do not mean changes of level in the sea-bottom, whether of past or present elevation, what do they mean? Forces are unceasingly acting, and there is no reason why an elevating force once set in action in the centre of an ocean should cease to act until a continent is formed. They have acted and lifted out from the sea, in com- paratively recent geological time, the loftiest mountains on earth. Mr. Wallace himself admits repeatedly that sea-beds have been elevated 1000 fathoms, and islands have risen up from depths of 3000 fathoms; and to suppose that the upheaving forces are limited in power is, it seems to me, to again quote from Island Life, ‘utterly gratuitous, and entirely opposed to all the evidences at our com- mand.”’ In conclusion, I will only add that these ideas are obviously put forward tentatively, and await further proof or disproof. I propose next month to make the subject clearer by means of a diagram. J].—Tue CLASSIFICATION OF THE CAMBRIAN AND SILURIAN Rooks. By J. KE. Marr, B.A., F.G.S. PAPER by M. Barrande, which has been recently published,' seems to call for some reply. M. Barrande, whilst working out the succession in Bohemia, adopted Sir R. I. Murchison’s name “Silurian,” and even applied it to lower rocks than did ever _1 «Ju Maintien de la Nomenclature établie par M. Murchison, par M. J. Barrande,’’ Extrait du Compte Rendu Sténographique du Congrés International de Géologie, tenu & Paris du 29 au 31 aout et du 2 au 4 Septembre, 1878. 246 J. BE. Marr—Cambrian and Silurian Rocks. Murchison himself, and in the paper under consideration he supports this classification. Jt may seem presumptuous to question the adoption of this classification by the great expositor of the Bohemian basin, but I would submit that it is not sufficient to judge of the merits or demerits of an historical classification, from its application to an isolated area, apart from the classical one, but it should be ascer- tained whether it can be applied over much larger tracts of country. M. Barrande first expresses a regret that Murchison and Sedgwick studied only stratigraphical geology, and neglected paleontology, and attributes to this cause the confusion which has arisen. But not only had these two geologists considerable knowledge of palaon- tology themselves, but they also employed palxontologists of the first rank to assist them in their labours. Moreover, so far from the confusion having arisen from paleontological errors, it arose from mistakes in stratigraphy, in which the Woodwardian Professor had no part; it would be presumption on my part to enter further into this personal question, after the masterly essays of Sedgwick in the prefaces to “ British Paleozoic Rocks and Fossils,” and “A Catalogue of Cambrian and Silurian Fossils,” and the able defence of Sterry Hunt, reprinted in his “‘ Chemical and Geological Essays.” M. Barrande then goes on to state that the three faunas which he names primordial, second, and third, can be traced over very wide areas, whereas the smaller subdivisions (éfages) have no exact parallelism in different countries. This is to a certain extent true of deposits formed in shallow water, but the black muds which indicate deep-water conditions are very widely spread. I may cite as an instance of this the occurrence of the Arenig fauna in countries as widely separated as Britain, Sweden, Bohemia, France, and Spain. The characteristics given of the three faunas admit of so many exceptions, as to be of very doubtful classificatory value. The primordial fauna is said to be composed almost entirely of Trilobites : this may be the case where the deposits are of a deep-sea character ; but whenever indications of shallow water occur, Brachiopods abound, e.g. in the Lingula Flags of Britain, the Olenus beds of Scandinavia, where Orthis is very abundant in the calcareous beds,! and in a paper read before the Geological Society, June 9th, 1880, I gave reasons for supposing certain grits of Bohemia, crowded with Lingula Feistmanteli, to be the equivalents of the Lingula Flags of Britain. ‘In the second place these primordial Trilobites are characterized by their conformation,” the head is small, the thorax large, and the tail scanty (eawigu) ; this scantiness is explained as not referring to the extent of the tail, but to the small number of segments of which it is composed. In reply to this I may remark that the tails of such genera of the second and third faunas as Remopleurides, Acidaspis, and various genera of the Cheirwride are strictly comparable to those of Paradomides, ete., of the primordial fauna. * Cf. Linnarsson, Bihang till K. Svenska Vet. Akad. Handl. Band 3, No. 12. J. LH. Marr—Cambrian and Silurian Rocks. DAG The second fauna is described as possessing Trilobites which contrast with those of the primordial group ; either the head, thorax, and tail are pretty nearly in equilibrium, as in Asaphus, or the thorax is reduced, and the head and tail developed, as in Illenus. But Illenus possesses no segments to the pygidium, and this is the case with the primordial Microdiscus and Agnostus, which also have a reduced thorax. Lastly there are several Trilobites of the second fauna, comparable with others of the primordial, such as Calymene with Conocoryphe, and Harpes with Erinnys, and the tails of these do not possess very many segments, and are quite disproportional to the thorax in their size, and the number of segments. M. Barrande believes that the second fauna is also characterized by fossils which have never been found in the preceding fauna. These are chiefly Cephalopods and Lamellibranchs. But the occurrence of an abundance of Cephalopods and Lamellibranchs in the earlier beds of the second fauna, e.g. in the Orthoceras Limestone of Sweden, and in the Tremadoc rocks of Ramsey Island, as shown by Dr. Hicks (Q.J.G.S. Feb. 1873), would indicate that they must have previously existed in the earlier fauna; migration with certain physical conditions, as kindly suggested to me by Dr. Hicks, will account for their absence, so far as known, in the European area. In short we may object to the first of M. Barrande’s arguments, that the primordial beds have not been yet studied over a sufficiently large area for us to say definitely that they are without Cephalopods or Lamellibranchs anywhere; in fact the evidence goes to point to the fact that they must have existed somewhere at this time. To the second argument we may object that characters which are hardly of generic value in the Trilobites! can scarcely be of much value as assisting the classification of large groups of beds, especially when there are so many exceptions to the rules laid down. M. Barrande proceeds to point out that although in his opinion these three faunas are distinct, there exist nevertheless beds of passage between them in certain countries. Such he considers to be the Tremadoc rocks of England. In these beds he recognizes rare representatives of the primordial fauna, as Conocoryphe (Cono- cephalites) and Olenus, whilst with these appear Trilobites more characteristic of the second fauna, as Niobe and Psilocephalus or Iilenus. In a paper on Bohemia, already referred to, I pointed out reasons for concluding that Band D. d. 1 #8. of M. Barrande repre- sented the Tremadoc rocks of England, and that among the scanty fauna obtained from it, there occurred the primordial Harpides, with Amphion, a Trilobite found in Barrande’s second fauna. The beds of Hof, in Bavaria, described by M. Barrande as containing forms both of primordial and second faunas, also seem to be referable to the Tremadoc rocks. The Tremadoc rocks of Shropshire (ef. Callaway, Q.J.G.S. vol. xxxiii. p. 652) also have a fauna somewhat 1 Of the genus Phacops, the subgenus Chasmops has a large tail and many seg- ments, the subgenera Phacops proper and Acaste have much smaller ones, and few segments relatively to the thorax. 248 J. EH. Marr—Camnbrian and Silurian Rocks. intermediate between M. Barrande’s first two faunas, especially after the light thrown upon the fossils of this group by Dr. Linnarsson (Grout. Mac. Decade II. Vol. V. p. 188). The Tremadoc group is considered by M. Barrande as appertaining from its base to his second fauna. He states that unfortunately some English geologists have associated it with part of the true primordial fauna, in the subdivision which they name Upper Cambrian. If we analyze the list of Tremadoc fossils given in Salter’s Catalogue of Cambrian and Silurian Fossils in the Wood- wardian Museum, we find that of eleven genera, two are peculiar to the Tremadoc beds, one occurs both above and below, two occur below only, and six above only. This seems to bear out M. Barrande’s view of the relation of this formation. Consequently those English geologists who have a tripartite division at present, ought to have a quadripartite one, or at any rate to shift their boundary-line in one case. But, indeed, we can draw hard paleontological lines between most of the groups of the so-called primordial beds in Britain, and I think that the explanation of this is evident. The primordial fauna of Bohemia is the representative of only one English formation, viz. the Menevian; when the so-called primordial group in Britain has been searched for fossils as carefully and persistently as that part of it in Bohemia which is fossiliferous, these breaks will disappear. In England our opportunities of collecting fossils are rarer than are those of foreign geologists ; consequently we show a preference for working out the richer zones, and do not give so much time as wouid be desirable to the more barren inter- mediate beds. Proceeding to consider the boundary between his second and third faunas, M. Barrande says that in the Llandovery group of England, which has been well studied, the inferior portion contains principally species of the second fauna, whilst the superior holds a majority of species of the third fauna. Our geologists now, however, usually group the Llandovery or May Hili Group entirely with the beds containing the upper fauna, whilst so far is our knowledge of these rocks from being complete, that there is still a great deal of con- fusion as to certain beds, whether they are of Upper Bala age, or belong to the lower part of the May Hill beds. I have in a recent paper (Q.J.G.S. 1880, p. 591) endeavoured to show that M. Barrande’s “Colonies,” which he appeals to as affording a mixture of the organisms of his second and third faunas, are to be explained as due entirely to physical disturbances. M. Barrande states that Murchison’s nomenclature is adopted by the Geological Society of London with the consent of nearly all European geologists, and that the names “Primordial Silurian,” ‘Lower Silurian,” and “ Upper Silurian,” are employed in the last edition of ‘“ Siluria,” a classic work which is in the hands of all geologists upon both continents. The amount of agreement with regard to this classification is shown in the following table, partly compiled from the list in Salter’s Catalogue of Cambrian and Silurian Fossils in the Woodwardian Museum : J. H. Marr—Cambrian and Silurian Rocks. 249 Eases a> es isp ely ee) IS! 5 S| eee 5 Shy ouey, ue SMP Sn Be BH ef 6 eer as SS acl ee eS =) aint (a aa Sees 5 & : Seat See is Bilis lie a a Se mS : Sh emavecpn parts iis ie B& MOE Mio Ye pe By TM CAMBRIAN. SILURIAN. S —S— Uy SY WV-——~,--— UC —~-—_ Z OF Pp 7 = = aU eat LOWER UPPER = 3 Gee SILURIAN. SILURIAN. | && SS eyes oe See E cay —~—-— —Y) ——~-— S = LOWER SILURIAN, or UPPER Be. 7 CAMBRO-SILURIAN. SILURIAN. | $8 i) ere IG Ry Ula en — = CAMBRIAN. LOWER UPPER BS SILURIAN. SILURIAN. a L+H V+ W.-Y a tg CAMBRIAN. LOWER UPPER Be SILURIAN. SILURIAN. | 25 —~- LY a eee UW —~-— = nf E, LOWER SILURIAN. UPPER ee a SILURIAN. | &3®. = es CAMBRIAN. Orpoyicran. SILURIAN. ae a a) : SILURIAN. ae With this list before us, it is impossible to say that geologists are agreed with regard to one or another classification. Nor are foreign 250 J. HE. Marr—Cambrian and Silurian Rocks. geologists at all agreed as to their nomenclature; for although they use the terms Silurian and Cambrian, they are used in various senses. In Sweden, for instance, the Lobiferus and Retiolites Beds, respec- tively representing the May Hill and part of the Wenlock of Britain (cf. Tornqvist, Ofversigt af K. Vetensk.- Akad. Forhandl. 1879, No. 2, p. 72), are by some authors classed as Lower Silurian. What nomenclature then are we to adopt? No classification depending on natural breaks is applicable over an enormously large area, for very obvious reasons, but yet the British names of other formations than the Cambrian and Silurian are very largely used by European and other geologists, when describing their own areas. Nor are these groupings comparable with one another as regards size; for example, the Pliocene cannot be compared in magnitude with the Carboniferous, and yet these names are used as of equal value in the lists of systems given in our text-books. In short, our present classification may be described as an historical one; such being the case, the names Cambrian and Silurian should be used in their historical sense, until our entire nomenclature is re-modelled, and hence the word Cambrian should include the rocks from the base of the Harlech Beds to the top of the Bala group, as defined by its historian Sedgwick. The term thus used is also natural to as great an extent as, if not greater than, that for any other system, for it seems that the movements which affected the northern hemisphere in the Old World were very wide- spread during the deposition of the old rocks; the beds deposited in deeper water can be traced continuously over very large areas, e.g. the Arenig beds occurring as black muds in Britain, Southern Sweden, France, Spain, and Bohemia, also the representatives of the Birkhill Shales and of the beds characterized by Retiolites Geinitzianus ; consequently if these areas were contemporaneously submerged to some depth, it follows that the intermediate upheavals were also contemporaneous, and the greatest upheaval throughout Europe seems to have been after the end of the Bala period, so that even where the deposits were not actually raised above the water, as they were in many cases, there was deposition in very shallow water. This is the greatest upheaval in the European area which occurred throughout the periods between the deposition of the Harlech Beds and that of the Ludlow, and it is accompanied by a paleonto- logical break. Other physical breaks are local, and seem to have been due, not to widespread upheavals, but to local volcanic action, and hence are of no classificatory value; such is the break at the base of the Coniston Limestone of the English Lake District, and that at the base of Htage D. of Bohemia. English geologists are requested to bring their nomenclature before the International Commission for the Unification of Geological Nomenclature. A classification must therefore be adopted for our Lower Palaozoic rocks; let us then be consistent, and add the names Cambrian and Silurian in their historical sense to the remainder of our historical names, especially as by so doing we make the nearest possible approach to a natural nomenclature, and although late, do justice to the great work of one of our greatest geologists. H. H. Howorth—The Mammoth in Europe. 251 IiJ.—Tuz Mammors 1x Europe. By Henry H. Howorrn, F.S.A. (Continued from page 205.) a France deposits of the same kind, such as those at Menche- court, are familiar enough. ‘To complete our merely illustrative list of examples, I would quote the vast deposits found in the offing of the Thames, and right away to the Dutch coast. Dr. Bree says that the bones occur in such quantities on the sea-bottom off Dun- kirk that the sailors call it the Burying Ground (Leith Adams’s Mem. on Elephas primigenius, p. 73). The identity of conditions in Hurope and Siberia is carried out in other details. The deposit in which the bones occur is in both a fresh-water one, consisting of marly clay and of gravel, and its contents are of the same class. We mentioned in a previous paper how Schmidt found the remains of the Mammoth mixed with land and fluviatile shells. This is precisely the character of the corresponding beds in Western Europe, only that in the latter, from the fact of their having been examined with much more critical care, the number of species of such shells recorded is very much greater. The discovery of these fresh-water shells is so constant, and they are so exceedingly numerous in the beds containing Mammoths’ remains, ete., that it is perfectly useless to enumerate in detail the localities where they have occurred. In Ireland, in the marl under- lying the peat, with the Megaceros; in Hngland, in various neigh- bourhoods with the so-called Pleistocene fauna; and in France, in beds of the same horizon. We are told that sixty-five species of such shells have been found at Menchecourt, thirty-three at Saint- Acheul, and eighteen at Saint-Roch. They have been found in the valley of the Saone, of the Somme, in Dauphiny, and the Jura. The Loess in the valley of the Rhine and its tributaries is very full of such shells; so are the similar deposits in the Vosges and the Black Forest. In the 29th volume of the Bulletin of the French Geological Society, p. 832, will be found an account of similar deposits in the valley of the Danube, also containing shells of the same class. The fact is they may be said to be universally present in these beds. The great abundance of their remains prove that the conditions must have been singularly favourable for the development of such molluses. They point the same moral as the similar shells found in Siberia. The species, with the exception of a few to which I shall revert presently, are the same as those still found in the Western Palearctic region. M. Daubrée says of the shells found in the Loess of the Rhine Valley that some species are very common, namely, Succinea oblonga, var. elongata, Helix hispida, Pupa muscorum, Helia arbusto- rum, Clausilia parvula, Pupa columella, Pupa edentulata, Helix erystallina, Olausilia gracilis, Helix pulchella, Helix montana, Pupa dolium, Clausilia dubia, Pupa pygmea, Bulimus lubricus, and Pupa secale. Seven other species are very rare. Of the whole number only 252 H. H. Howorth—The Mammoth in Europe. one, namely, Limnea minuta, is fluviatile, and of this only 28 indi- viduals out of 200,000 specimens have been noted. The greater part of these species, says our author, still live in the country ; ; the rest are so little different that they may be treated as mere varieties. Nearly all still live in cold damp climates, and some in the Alps as high as the limits of snow (Bull. Geol. Soc. of France, vol. xxiv. p- 490). Heer, speaking of the same class of shells, refers to the twenty- one species found by Professor Mousson in the Gallen part of the Rhine Valley, and described by him in the Transactions of the Natural History Society of Zurich in 1856, says they still without exception occur in Eastern Switzerland, most of them in the valley of the Rhine or at the foot of the nearest mountain slopes. Helix ruderata is not now found in the plain, however, and only in the highest mountain region, that of the mountains of Glaris, Priittigau and the Senlis chain. Helix sericea glabella and Helix arbustorum subalpina also belong to the mountain region. Helix strigella, with a wide umbilicus, still occurs near Sargans, and is peculiar to that district. All the species except the four first named, says Heer, are either forest snails from the region of leafy trees, or species which prefer shady moist places. Inhabitants of dry sunny localities are wanting. . . . Speaking of the Loess of the Lower Rhine, he says of the numerous snails which have been collected in it, the species of shady moist localities certainly predominate, and with them are mixed certain forms (such as Helix hispida, Helix ruderata, and Helix arbustorum subalpina), which at present are met with only in high mountains, while no species occur which belong to warm sunny localities (Prim. World of Switzerland, vol. i. pp. 213 and 214). M. Tournouér, in describing the similar mollusca from the tuffs of Moret in the valley of the Seine, says that thirty-five species in all were discovered. They must have lived in the recesses of moist woods attached to leaves, to tender herbaceous plants, and to rocks where water fell; some were probably brought down from a higher level by torrents. Of the thirty-five species just named, one half still live in the neighbourhood; of the rest, some, like the Helix limbata, belong to the sub-Pyrenean district of South-western France, others to the mountain districts of the Alps and Jura. Of this class are Bulimus montanus, Clausilia dubia, Pomatia septem-spiralis, etc.; some to Hastern Europe, as Helix bidens, Clausilia pumila, ete. ; others again to Southern forms, as Vitrina major, Zonites acies, a Helix, like Helix fruticum, etc. Some kinds seem to be extinct, as Succinea Joinvillensis, Cyclostoma lutetianum, several forms of Succinea, Zonites, and Clausilia. The most common species at Moret are the Helix arbustorum and nemoralis, still found over all Central and Northern Europe. The whole class found here is singularly like the parallel class from Canstadt, in Wurtemberg, both deposits being marked by the peculiar forms Helix bidens and Zonites acies. They bespeak a diffusion of Huropean species more uniform than prevails now, with a damp and more uniform climate than now prevails, and at Moret one with a somewhat higher mean tempera- H, H, Howorth—The Mammoth in Europe. 253 ture, more like that now prevailing on the southern flanks of the Alps, in Friouli, and Croatia, where alone are now found the great Zonites (verticillus, croaticus, etc.), the Helix nemoralis, Helix arbus- torum, and Helix bidens (Report of the International Congress of Anthropolog ry at Stockholm, pp. 104-106). This evidence is assuredly coincident with that furnished by the fresh-water shells of the Siberian strata, in which Mammoths’ remains occur, and especially by the remarkable fact that such a southern form as Cyrena fluminalis occurs there (see Belt on the Superficial Deposits of Siberia, Journal Geological Society, vol. xxx. p- 490, etc.). These mollusca not only point to a mild climate but to one which was comparatively mild all the year round. For they could not migrate with the seasons nor could they survive an arctic tem- perature. The same conclusion is attested by the remains of plants. Here I would quote a curious passage from an essay by Baer, entitled “De Fossilibus Mammalium Reliquiis,” ete., in which he describes the discovery of a number of trunks of birch trees with bones of Mammoths. I will quote his own graphic words. ‘In ponendo fundamento domus, custodi noni emissarii canalis Bromber- gensis destinatae, repertum est sub turfa, 9 pedes alta, stratum arenae tenuis et huic incumbens, magnus arborum numerus cortice fere incolumi, necnon ossium maximorum farrago, quorum wmulta, e fossa extracta sunt... . Clar. Wutzke, e consiliis regiminis, qui canali huic fodiendo, praefuit, de hac re a me interrogatus dentes effossos, dentibus mammonteis omnino similes fuisse affirmavit. Memoratu dignissimum videtur sceleton in sylva prostrata inventum esse, et quidem inter arbores, quos plaga nostra et hodie gignit. Con- tendit vir laudatus quanquam lignum corruptum invenisset, ex cortice Betulam albam se agnovisse nec unum inter operarias fuisse qui non idem censisset. Quid strias fuscas, quibus praeter alias gaudet cortex betulinus, conspicuas observavit vir in his rebus peritissimus. Num ex relatio concludere eis elephantem primigenium in patria nostra, betuletis inhabitasse et ergo non tropicam temperiem expertum esse, an mavis casu quodam terrae superficiel commotiones Betulas cum reliquis Mammonteis ex antiquiore aevo superstitibus in maris fundo quem arena indicat commiscuisse” (op. cit. pp. 15 and 16). Mammoths’ remains were found associated with cones of the Pinus sylvestris at Sprottau, in Silesia (Quarterly Review, vol. cxiv. p. 378), but it is the evidence recently adduced by Heer and Saporta which is the most valuable. The former has written on the Plant Remains from the Quaternary deposits so rich in Mammoth remains at Canstadt in Wurtemberg and elsewhere, and the latter on the similar remains from Moret, in the valley of the Seine. From the tuffs of Canstadt Professor Heer has succeeded in identifying 29 species of plants; these comprised a large oak with obtusely and widely lobate leaves, six inches broad, and oval acorns nearly twice as large as those of Quercus pedunculata; a poplar with large cordate ilear ae with but faintly undulated leaves (Populus Fraasii, Heer); a walnut, like the American Juglans nigra and 254 H. H. Howorth—The Mammoth in Europe. cinerea; and among the species still living there, the red fir, the white birch, the hazel and the sycamore, the white fir, aspen, silver poplar, pedunculated oak, hornbeam, elm, lime tree and spindle tree, the Salix monandra, fragilis, aurita, siminalis, and especially Salix cinerea, the Cornus sanguinea, the Rhamnus frangula and catharticus, the box, the Vaccinium uliginosum, the great manna grass (Glyceria spectabilis) the reed and the harts’ tongue (Scolopendrum officinale). Except the extinct species and the box, all these plants now live in Wurtemberg ; the sycamore is not found at Canstadt however, but in the mountains, and the whortleberry in the peat bogs. ‘On the whole,” says Heer, ‘“‘climatal conditions are implied in the flora of Canstadt similar to those now prevalent in the same locality.” In old turbaries of Ivrea and in drift debris near Mur in Styria trunks of the Siberian pine (Pinus cembra) have been found, and near Schwerzenbach, in the Canton of Zurich, in drift loam, Betula nana, Salix retusa, Salix reticulata, Salix polaris, Polygonum viviparum and Dryas octopetala (Heer, op. cit. pp. 206-7). This more northern flora is perhaps due to the proximity of the Alps, or it perhaps belongs to a somewhat earlier period. It is very probable indeed that the white clay band above the Bovey Tracey Lignites, which was described by Professor Heer and others in the 152nd volume of the Philosophical Transactions, is of the same age as the brick-earths and white marls in which the Mammoth occurs. It is interesting to note that Professor Heer recovered from this clay leaves of the Betula nana, and of three species of Salices which he. identified respectively with Salix cinerea, Salix repens, and Salix ambigua. The first of these points to Devonshire then having had a colder climate than now, it not being found south of Scotland; the evidence of the willow leaves, says Professor Heer, is the same, indicating that at this time Bovey was a cold peat moor. He remarks that Salia cinerea is one of the commonest species at Canstadt (op. cit. p. 1044). M. Saporta’s researches have been devoted to the French strata, and he communicated a most interesting paper to the Stockholm meeting of Anthropologists in 1874, on the flora of the tuffs of Moret in the Seine Valley, already referred to. The following plants have been found there: Scolopendrium officinale, Corylus avellana, Salix cinerea, Salix fragilis, Populus canescens, Ficus carica, Fraxinus excelsior, Viburnum tinus, Hedera helix, Clematis vitalba, Taxus sempervirens, Acer pseudo-platanus, Euonymus Huropeus, fuonymus latifolius, Cercis siliquastrum. Of these fifteen species, five are not now found at Moret, namely, Ficus carica, Viburnum tinus, Tavus sempervirens, Huonymus latifolius, and Cercis siliquastrum. The whole of the plants found at Moret are also found at Canstadt, except the Cercis, the Viburnum, and the Ficus. The co-existence of these species, says M. Saporta, proves very clearly that, notwith- standing the variations due to latitude, Hurope from the Mediter- ranean to its central districts offered fewer contrasts, and was more uniform than it is now. A more equable climate, damp and clement, allowed the Acer pseudo-platanus and the fig to live associated together near Paris, as it allowed the reindeer and hyena. ‘The H. H. Howorth—The Mammoth in Europe. 255 Acer grows with difficulty now where the Ficus grows wild, while the latter has to be protected in winter in the latitude of Paris (op. cit. pp. 192, 104). In this debris of the flora we not only have a capital means of fixing the isothermals of the period when, and the district where, the Mammoth and his companions lived, but also have no doubt a fair list of the plants upon which he was accustomed to feed. The evidence of the animals found with the Mammoth in Western Hurope and Siberia points to precisely the same conclusion. Un- fortunately we have had only very incomplete researches in the latter area, but we know that the Rhinoceros tichorhinus, Bison priscus, Bos primigenius, Hquus caballus, and the Ovibos moschatus occur there, and all these occur together in the west; but further we find in these deposits in the west several animals which are still living in Siberia, and which have no doubt survived from the epoch of the Mammoth, but are no longer found living in Hurope, such as the Saiga Antelope, the Reindeer, the Lemming, two species of Spermophilus, etc. The presence of these animals in both areas points most forcibly to the climatic and other conditions having been alike in both, a view which is much confirmed by the famous discovery described by Mr. John Evans, in the 20th volume of the Journal of the Geological Society, of not only bones of the wild goose which have occurred elsewhere in Hurope, but also of portions of egg-shells, in all probability belonging to the same bird, which still breeds in such enormous numbers in Siberia. The immense deposits of fluviatile mollusca from the beds we have described prove what a famous feeding ground Hurope must then have been for the wild goose, and shows why Hurope should then have been its breeding quarters, it being widely held now that the summer habitat of birds is mainly fixed by abundance of suitable food. While the evidence of the Mammals is satisfactory that a con- tinuous climate and conditions ranged over both Siberia and HKurope, their evidence is also consistent with that of the other factors we have adduced, that the climate must have been a temperate, and doubtless one with a more equable mean between summer and winter, marked perhaps by an isotherm very like the one which now characterizes Central Europe. This is surely pointed by the dis- covery of bones of Lepus timidus, near Salisbury, described by Mr. Evans in the paper already cited, and the more important discovery of remains of the Sorex araneus, of young moles, of the Lepus timidus, - of the common squirrel, of the Mus terrestris, and of many bones of frogs, together with those of the Mammoth, Rhinoceros, and Hyena, at Kostritz (see Schlotheim zur Petrefactenkunde, Gotha, 1822). It would seem, therefore, that Siberia and Hurope during the period of the Mammoth formed one zoological province, which in Western Europe more or less overlapped with an entirely different province then occupying the Mediterranean border-land, and of which some sporadic elements, such as the Hippopotamus, the Ehinoceros leptorhinus, and probably the Machairodus, extended into Mid-Britain. These mammals are matched among the mollusca 256 E. T. Newton—Pre- Glacial Mammalia. by large specimens of Cyclostoma elegans, like those found in Northern Italy, the Cyrena fluminalis now living in the zone from the Caspian to Syria, larger specimens of Helix arbustorum, also pointing to a higher temperature, and Vitrina elongata, now living in the South of France, and these again by such plants as the Ficus carica. The conclusion from these various facts seems inevitable that just as the companions and the various conditions of life which sur- rounded the Mammoth in Europe were the same as those in Siberia, so its mode of life was the same. That it lived and died where its remains are now found in a climate marked by a temperate character all the year round, and further that the causes of its disappearance were probably the same in both. The consideration of this last very critical question I propose, with the permission of the Hditors, to postpone to another paper. I ought to state that this paper was written some time before the publication and entirely independent of Mr. Geikie’s very admirable work on “ Prehistoric Europe.” IV.—Nores oN THE VERTEBRATA OF THE PreE-GuactiAL ForzEst Bep Series ofr THE Hast oF HNGLAND. By E. T. Newton, F.G.S. (Published by permission of the Director-General of the Geological Survey.) PART IV.—RODENTIA AND INSECTIVORA. S in the previous notes (Grou. Mac. Decade II. Vol. VII. No. 10, p. 447, 1880), so in the present, it is deemed desirable to give in the first instance a complete list of all the examples of the groups under consideration, which have hitherto been recorded, and then, having examined each critically, finally to give a corrected list. RopENTIA AND INSECTIVORA SAID TO HAVE BEEN FOUND IN THE “‘ Forest BED Serizs.’’ (See also corrected list, at p. 259.) Trogontherium Cuviert. Sciurus, sp. Castor fiber (= C. Europeus). Mus musculus. Arvicola amphibia. Talpa Europea. agrestis. Sorex fodiens. arvalis. remifer. glareolus. Myogale moschata. Ropentia. Trogontherium.—In the year 1846, Prof. Owen referred certain lower jaws of a large Rodent, obtained from the Forest Bed, to Fisher’s genus Trogontherium, with the specific name of T. Cuvieri (Brit. Foss. Mams. p. 184). Sir C. Lyell had already referred to these specimens in 1840 (London and Edinb. Phil. Mag. ser. 3, vol. xvi. p. 845), on Prof. Owen’s authority, as belonging in all pro- bability to a species of Beaver distinct from the recent one. English writers have, since the year 1846, almost without an exception, received Prof. Owen’s determination; but on the Continent there has been great diversity of opinion, so much so, that the synonymy has become much too complicated for any attempt to be made to E. T. Newton—Pre- Glacial Mammalia. 257 explain it in the present notes. It will be sufficient to say that in 1869 M. Gervais (Zool. et Paléont. General, p. 80), adopted M. Pomel’s name of Diabroticus Schmerlingit for these large ‘ Forest Bed” Beavers, believing that their affinity with Fisher’s Trogontherium had not been established. Prof. Owen, however, in 1869 (GEOL. Mae. Vol. VI. p. 49), described other specimens of these Rodents, and being still convinced that his previous determination was correct, retained the name of Trogontherium Cuviert. Since that time several examples of upper- and lower-jaw teeth, with limb-bones, have been obtained, and it is with no little satisfaction I am able to say, that these confirm, in an unexpected manner, Prof. Owen’s determination. Fisher’s type specimen was a skull without the lower jaw and having the cheek teeth in an early stage of wear, so that each exhibited four folds or islands of enamel; the hindermost one having two small additional folds. The first British specimens found were lower jaws, so that it was extremely difficult to compare them, especially as neither of them had the teeth in the same early con- dition of wear as the type. The only upper jaw with teeth which was known, until quite recently, was that figured by Prof. Owen in 1869 (loc. cit.), and in this the only two teeth which were perfect had each only two folds, and consequently differed much from the original specimen. On this account several writers were of opinion that they could not be referred even to the same genus. An exami- nation of the numerous teeth, both lower and upper, which are now to be found in various collections, show in a most conclusive manner, as if seems to me, that the folds of enamel, which in the early con- dition are all connected with the exterior surface of the crown, rapidly lose their connexion and become isolated, as is the case with most of the folds in Mr. Fisher’s type. Gradually as the tooth wears some of the islands of enamel become obliterated, and hence in old examples some of the teeth may exhibit only two folds, as in the upper jaw figured by Prof. Owen and mentioned above. One series of upper teeth, in Mr. Savin’s Collection, agrees as closely as possible with Fisher’s original specimen as figured by Rouillier. The great difference, which Prof. Owen maintained there existed, between this large “‘ Forest Bed” Beaver and the recent forms of Castor, is likewise confirmed by recent acquisitions. Not only do these differences extend to the forms and proportions of the grinding teeth and incisors, both upper and lower, but also to the form of the lower jaw itself and to the bones of the limbs. There is no evidence of a second species of Trogontheriwm from the “Forest Bed,” all the remains at present found being referable to T. Cuvieri. These remains have been obtained at Cromer, Mundesley, Bacton, West Runton, and Kessingland, and Mr. R. Fitch has an incisor from the Norwich Crag of Thorpe. Castor.—The remains of Beavers were among the earliest Mam- malian bones obtained from the “ Forest Bed,’ and were mentioned by 8S. Woodward in 1888 (Geol. Norfolk), and referred to Custor fiber. I have been unable to trace any remains of the true Beaver among the older specimens, except one tooth in the King Collection, and DECADE II.—yYOL. VIII.—NO. VI. 17 258 E. T. Newton—Pre- Glacial Mammaiia. am inclined to think that most of the remains referred to as Castor were really T'rogontherium. However, quite recently two or three undoubted examples have been found at West Runton and Kessing- land, so that there is no question as to the occurrence of this genus in the “‘ Forest Bed Series.” I have preferred to retain Prof. Owen’s name of Castor Huropeus, seeing that good authorities acknowledge a constant, though slight, difference between this form and the American Beaver. Arvicola.—The remains of Voles were recognized among the « Forest Bed” Mammalia as early as the year 1840 (Lyell, Lond. Hdin. Phil. Mag. ser. 3, vol. xvi. p. 545). Prof. Owen seems to have been the first to refer any of them to the Arvicola amphibia (Brit. Foss. Mams. 1846, p. 205); and since then it has been included in most of the lists. Within the last few years remains of a smaller species have been found, and these have been referred by different writers to the species given in the list above. After a careful examination of a large series of Voles’ remains, including, as | believe, all the im- portant specimens hitherto found, I am led to the following con- clusions: 1st. That of the larger forms of Vole found in the “Forest Bed,” the greater number have well-developed fangs to the cheek teeth, in the adult condition, and on this account they cannot be referred to the common Vole, although the patterns of the teeth are almost identical in the two. I propose therefore to call this species Arvicola (Hvotomys, Coues) intermedia, in reference to the intermediate position which it occupies between the T.—Fritrscu’s Permian AMPHIBIANS OF BOHEMIA. HE second part of Dr. Fritsch’s Monograph of the Fauna of the Permian Rocks of Bohemia fully sustains the interest of the first volume. It consists of 34 quarto pages of text, amply illustrated by many figures printed in the text, and by 12 coloured plates. It is impossible not to regard with admiration a work so fully and wisely illustrated; but equally in the literary work the author has endeavoured to give his labours completeness of expression, not so much with the object it may be of making the task of future labourers a sinecure, as in a happy endeavour to say everything that is worth knowing about his fossils. This memoir commences with some general remarks on the Branchiosauride, in which the opinion is expressed and sustained that several of the Stegocephali which have been described in other countries must be included in this family, so that the author finally arranges in it the following ten Reviews—Fritsch’s Permian Amphibia. 273 genera :—Branchiosaurus (Fr.), Amphibamus (Cope), Pelion (Cope), Protriton (Gaudry), Pleuroneura (Gaudry), Sparodus (Fr.), Brachider- peton (H. and A.), Hylerpeton (Owen), Dawsonia (Fr.), Hylonomus ? (Dawson). The next family treated of is termed Apateonide, but the author finds all his specimens referable to a genus which is named J/elaner- peton. 'This genus is defined as differing from Branchiosaurus in the form and proportions of the head and in its length relatively to the body, for while the head is between a third and a fourth of the length of the body in Branchiosaurus, it is here between a fourth and less than a fifth. The brain case has a similar posterior develop- ment to that seen in Branchiosaurus; the supratemporal bones are placed more anteriorly. The width of the vertebrz is to the length of the vertebral column as 1 to 8 in Branchiosaurus, while in Melanerpeton the proportion is 1 to 11 or 1 to 13. The sacral vertebrae enlarge and the ribs attached to them are modified in form. The ribs are short, and extend throughout the body, and are developed in the first five caudal vertebrae. The thoracic plates have a median stalk-like prolongation or interclavicular process. The abdominal armour was either absent or but faintly developed. Of this genus three species are described. The paleontological value of these presumed generic characters may perhaps require further considera- tion. Melanerpeton pusillum is estimated to have been 46 to 55 mm. long. The head, which did not exceed a cen- timétre, has been carefully restored; but the restoration wants the quadrate-jugal and quadrate bones. According Melanerpeton pusillum (Fritsch). Natural to the figure, though I do size. From the Permian Limestone of not find any corresponding Olberg near Brannan. explanation in the text, the pre-frontal and supra-tem- poral bones are both blended with the jugal. The external or anterior nares appear to be in contact with each other, and occupy the middle line of the snout just behind the pre-maxillary bones. There are two small fontanelles about the size of the parietal foramen placed in the middle of the suture between the nasal and frontal bones; there also appears to have been a fontanelle in the middle of the suture between the supra-occipital bones. The maxillary bone contains 11 smooth small teeth. Jelanerpeton pulcherrimus is a much larger species, having a length of 125 mm. The body is three times as long as the head. The skull is sub- triangular, being broad behind and relatively shorter than in Melanerpeton pusillum. The supra-temporal bone is deeply excavated behind. The surface structure of the skull bones is radiated. The author describes in detail the various elements of which it consists; but as the skull closely resembles that of Branchiosawrus (see Grou. Mae. Dee. II. Vol. VI. p. 524), it is unnecessary to describe it fully now. DECADE II.—yYOL. VIII.—NO. VI. 18 274 Reviews—Fritsch’s Permian Amphibia. The skin in this species is naked, or shows no certain evidence of scales. The vertebral column is well ossified. There are 23 dorsal vertebrae; 1 sacral; and 16 caudal vertebra, though 4 more were developed, making a total of 44. As in the allied forms the notochord persists. The transverse process is strong, and placed anteriorly. The hinder part of the vertebra is overlapped superiorly by the succeeding vertebra. The sacral vertebra is twice as wide as the last dorsal. The tail-vertebree are much shorter than the Melanerpeton pulcherrimum (Fritsch). Upper side of the skull, restored; 3} times natural size. im. intermaxillary; ms. maxillary; WN. nasal; £. frontal; P. prefrontal; tf. postfrontal; Pto. post- orbital; J. jugal; Pa. parietal; Sq. squamosal; Zp. epiotic; St. supratem- poral; Q. quadrate; So. supraoccipital. thoracic vertebre, and rapidly diminish in breadth. There are no ribs to the first five vertebre, though they may have existed; and the last three dorsal vertebra have the ribs short. The ribs in the tail are not so long as the vertebree are wide. The shoulder girdle is strongly developed. The middle thoracic plate has a broad shield shape with a median hinder process. In front of it are the two clavicles, the lateral parts of which are thin and cylindrical. ‘The coracoids are spoon-shaped, and the scapula like that of Branchio- saurus. The tore-foot is short. The humerus is four-sided, and as wide at the proximal end as it is long. There were five digits made up of very short phalanges. The femur is twice as long as wide, and, though longer than the humerus, is narrower. ‘The Reviews—Fritsch’s Permian Amphibia. 270 fibula is rather more slender than the tibia. The metatarsals were well developed, and twice as long as the ends are wide. Melanerpeton fallax (Fritsch) presents a very distinct form of skull, and I entertain but little doubt that it belongs to a distinct genus, which may be easily separated from Melanerpeton, not only by the skull-form, but by the skull structure. The outline is remarkably constricted posterior to the parietal foramen, anterior to which the shape is a broad blunt triangle. Between the broad pre-maxillary, oblong jugal and triangular pre-frontal a bone appears on the anterior margin of the orbit, which the author omits to name, but indicates by the letter /, that can only be the lachrymal. Post- frontal, post-orbital, and supra-temporal bones appear from the restoration to be blended together. A few remarks follow on the relation of Melanerpeton to Archego- saurus. Dolichosoma longissimum (Fr.), restoration half natural size. From the Coal of Nyran. 276 Reviews—Fritsch’s Permian Amphibia. The next family, Aistopoda, comprises snake-like animals devoid of limbs, with biconcave vertebrae, ribs, and smooth teeth. It is represented in Bohemia by the genera Dolichosoma, Ophiderpeton, Paleosiren, and Adenoderma. In Dolichosoma the skull is small ; it tapers towards the snout. There are 150 biconcave vertebre, with zygapophyses, and well-developed transverse processes. _Dolichosoma longissimum (Fritsch) is distinguished by having the ribs twice as long as the vertebra. In form it closely resembles the i777 im Dolichosoma longissimum, upper surface of skull restored, enlarged six times. whip-snake (Dendrophis). The fragment found measures 60 cm., and indicates for the entire animal a length of about a métre. An impression of the skin is preserved; enlarged 45 times it shows a Reviews—Fritsch’s Permian Amphibia. 277 fine granular structure, so that if any scales existed they are not preserved. The eyes are placed rather behind the middle line of the skull, and are separated by an interspace of two-thirds their diameter. The parietal foramen lies far behind the orbits. The anterior nares cannot be distinguished. The nasal bones (N.) are anchylosed together, and forked behind. The premaxillaries (im) resemble those of Siren lacertina. The maxillary (ms) is a strong bone extending to the anterior extremity of the snout, and to the middle of the orbit ; it carries about 15 smooth teeth, which are curved backward: there may have been two rows. ‘The frontal and parietal bones are blended into one mass. The frontal terminates in front in three processes. The epiotic terminates at its outer angle in a knob-like swelling. The teeth of the lower jaw, 20 in number, were smaller than those in the upper jaw. ‘There are indications of a branchial skeleton extending to the sixteenth vertebra. One hundred and fifty vertebree are preserved, but there may well have been fifty more. In the neck the ribs are simple, in the body they are com- plicated, and in the tail they are absent. The dorsal vertebra have a depressed elongated quadrate form, with a ridge in the position of the neural spine; the neural arch is constricted in the middle, and terminates at its four corners in zygapophyses. The transverse processes are compressed, directed downward and outward, and given off from the lower margin of the front of the centrum. The centrum has a circular cup at each end, and the cones unite, so that the notochord was persistent. The form of this vertebra may be com- pared with that of Epicrium glutinosum. ach vertebra has a slightly different shape. The tail vertebree are smaller and shorter, and have weak zygapophyses, and are perforated in the middle of the side as though for the passage of an intervertebral nerve. The ribs of the neck at the sixteenth vertebra are twice as long as the centrum. The dorsal ribs show towards the proximal end two peculiar processes. The proximal end is bent at nearly a right | angle to the body of the rib; the processes occur at the flexure, one is dorsal, and the other has a ventral direction. ‘These processes present some analogy to the uncinate processes on the ribs of birds. The author next describes Dolichosoma ( Ophiderpeton ?) angustatum (Fr.). The parieto-frontal region of the skull is very similar to that of Dolichosoma longissimum. There is some uncertainty felt as to its exact generic relations. The next genus in this family is Ophider- peton, of which five species are described. Ophiderpeton granulosum (Fr.) is covered on the back with horny shagreen-like scales, while the ventral surface is covered with small scutes pointed at both ends, half as long as the vertebrae, and arranged in a V pattern. The ventral scutes are parallel to each other, half as long as the vertebre. The body in form resembles Dolicho- soda. It is impossible to estimate its length, for the sixty vertebrae preserved show no variation in size. ‘The skull is badly preserved. The neural arch of the vertebra is deeply notched posteriorly (¢). From the posterior zygapophyses deep grooves (7) run forward and 278 Reviews—Fritsch’s Permian Amphibia. outward. The transverse processes (fr7) are near the middle of the centrum. The ribs are formed on the general plan of those of Dolichosoma, but the transverse processes are longer and nearer to the posterior end. Ophiderpeton pectinatum (Fr.) is only known from a few vertebre, some parallel pointed abdominal scutes and remarkable pectinated plates, supposed by the author to have been clasping sexual organs placed in the region of the cloaca; but their true nature may be doubtful. Upper view of vertebra of Ophiderpeton granulosum (Fritsch), enlarged 12 times. Ophiderpeton vicinum (Fr.). The ventral surface of the body was covered with oat-shaped scutes, while the dorsal armour had a shagreen-like character. The armour is similar to that of Ophider- peton Brownrigge (Huxley). Ophiderpeton Corvinii (Fr.) is founded on two specimens of a large pectinated plate. Ophiderpeton Zieglerinum (Fr.) is founded on ventral armour in which the scutes are from 16 to 20 times as long as broad. Paleosiren Beinertii (Geinitz) is briefly noticed and regarded as nearly related to Ophiderpeton; its vertebre are 10 cm. long and 8 cm. wide, indicating an animal that may have been fifteen métres in length. The armour is well developed. This part of the work concludes with a notice of Adenoderma gracile (Fr.), of which the skin is well preserved, showing, as the author believes, glands arranged in four rows. The head is crushed, as long as wide, and one-fifth as long as the body. There are 22 short biconcave vertebrae between the head and pelvic region. Five caudal vertebra are preserved. Short ribs are developed on the first 13 vertebre. Towards the end of the memoir Dr. Fritsch enunciates the conclu- sion that the Stegocephali may prove to be the ancestors both of Reviews—Action of Rain-water on Superficial Deposits. 279 Amphibians and Reptiles, a sound induction which must long have been making its way with philosophical naturalists. It is impossible to conclude this brief notice without congratulat- ing the author on the admirable way in which the memoir is pro- gressing. It is indeed a model of monographic work, wrought out of materials that would have discouraged if they did not bafile a writer less patient, able and painstaking than Dr. Fritsch, and may well call out the sympathy and admiration of his fellow-labourers among fossil vertebrates. H. G. SEELEY. II.—Mémorr= suR LES PHENOMENES D’ALTERATION DES D£&POTS SUPERFICIELS PAR L’ INFILTRATION DES EAUX METHORIQUES HTUDIES DANS LEURS RAPPORTS AVEC LA GEOLOGIE STRATIGRAPHIQUE. Par Eryest Van DEN Brogcs. 4to. pp. 180. One Coloured folding Plate, and 34 figures in the text. (Brussels, 1881.) VHIS handsome Memoir forms part of vol. xliv. of the quarto series published by the Royal Academy of Sciences of Belgium under the title of ‘Mémoires couronnés et Mémoires des savants étrangers.” Init Mr. Vanden Broeck, who is well known as one of the most zealous and active of the younger naturalists and geologists of his country, has brought together a great number of facts relating to the alteration of superficial deposits by the action of rain-water. This subject was first taken up by the author in 1874, and since that time he has taken every opportunity, by means of papers describing special cases exhibited in various portions of the Tertiary basin of the Netherlands, of calling the attention of geologists to the frequent misreading of sections, due to the want of care in distinguishing the altered, but undisturbed, parts of beds or groups of beds from unconformable deposits. One of the first cases of the kind, clearly explained by him, related to the Laekenian and Bruxellian of the Brussels Eocene. Here unfossiliferous sands, resting upon what had been generally regarded as strongly eroded surfaces of fossiliferous more or less calcareous rock, were shown to be really undisturbed portions of the latter, from which the carbonate of lime had been removed, and in which other changes, such as the oxidation of glauconite for instance, had taken place, by the action of rain-water.1 This is a fair sample of the kind of useful application that can be made for stratigraphical purposes of a proper knowledge of the results of the long-continued percolation of carbonated waters through sand and other deposits. Of course these effects have long been known to chemists and geologists, but their application towards the unravelling of the often obscure details of Tertiary geology is very largely, if not altogether, due to Mr. Vanden Broeck. In the present Memoir, after some general considerations respect- ing the réle of water, and especially rain-water, as an agent in the metamorphosis of rocks, the author describes its special action on felspathic, metalliferous, clayey and shaley, siliceous, and calcareous 1 See Annales de la Société géologique du Nord, t. iii. p. 174. 280 Reviews— Geology of Minnesota. rocks. The original matter of the paper is chiefly to be found under the last head, and in an appendix on infiltrations in Quater- nary deposits. All the sections described seem to bear out the author’s views very completely, but since many competent observers have failed to admit them in certain cases, such as that of the Red Drift of Paris, which Professor Hébert declines to regard as altered Grey Drift, it must be concluded that the evidence is not always so clear and satisfactory. But although all Mr. Vanden Broeck’s examples may not be accepted as proven by those specially conversant with the detailed structure of the many districts whence they have been collected, there is no reason to doubt the general truth and the important nature of his thesis. Indeed, illustrations are not wanting in England, as in the case of the shelly Red Crag of Suffolk, where Mr. Whitaker has shown that the supposed line of erosion between it and a certain unfossiliferous sand is really a line of dissolution of shells, the sand being simply Red Crag deprived of its fossils through the percolation of water." On the whole, Mr. Vanden Broeck’s Memoir must be welcomed as being, up to the present, the most complete epitome of a class of facts of considerable geological importance, which had been singularly neglected and ignored, until our author took them in hand in his own vigorous and enthusiastic manner. It may be added that Mr. Vanden Broeck would be glad to receive information as to any new facts or objections relating to the subject of his Memoir. Goa la: III.—Tur Gronocy oF Centrrat anp Western Minnesota. A Pre- liminary Report by Warren Upnam, Assist. on the Geol. and Nat. Hist. Surv. of the State, under the direction of Prof. N. H. Winchell, of the State University. From the General Report of Progress for 1879. 8vo. pp. 58. ieee a rather unpromising exterior, this memoir includes several matters of special interest. It will also attract atten- tion from the fact that it is the first report of the first student of Glacial Geology ever officially employed in his special capacity for a considerable period, and in a region over most of which glacial deposits prevail exclusively. In consequence of the paucity of natural exposures (which is a circumstance not to be deplored, since natural sections are so generally misleading), recourse has generally been had to artificial excavations, mainly wells, in determining the character of the glacial deposits. The records of no less than 582 wells have been examined and digested in the preparation of the report. A compact lower till, usually blue, and a less compact upper till, usually yellow or brownish, botb containing considerable intercalated sandy and pebbly layers, are recognized as of general extent ; and local deposits of modified drift, often presenting a kame-like aspect, are also described. Inter-glacial beds, containing soil, wood, plants, and 1 See Quart. Journ. Geol. Soc. Lond. vol. xxxiii. p. 122. Reviews—C. Struckmann—The Wealden of Hanover. 281 fresh-water or terrestrial shells, are recorded in a few instances, apparently always within the lower till, but generally near its upper surface. The superposition of glacial drift upon decomposed gneiss and granite is noted. Much attention has been given to the gigantic terminal moraine stretching in a sinuous line across Minnesota, and Dakota, and thence north-westward far upon the Saskatchewan plains in the adjacent British territory. The same moraine has already been traced across Wisconsin by Prof. T. C. Chamberlain, the director of the Geological Survey of that State, and is believed to exist also in Illinois, Indiana, Ohio, Pennsylvania, New York, and New Jersey. Beyond it has been explored by Upham along the north shore of Long Island, through Rhode Island, and along Cape Cod. The moraine thus appears to stretch, though with several interrup- tions, across more than half of the continent. It lies near the southern limit of ice-action in the east; but in the west it is fully three hundred miles north of that line. The silty deposits of the Red River Valley are described in some detail ; and the exploration of their origin is a valuable contribution to the glacial theory. It is suggested that as the ice-sheet retreated over surfaces sloping to the northward, the waters derived from its dissolution accumulated in all depressions to the level of the south-lyig divide. Such an accumulation is supposed to have taken place in the vast basin occupied by Red River and Lake Winnipeg ; and for it the very appropriate name of Lake Agassiz is proposed. The silts of the region are regarded as the finer glacial debris suspended in, and finally precipitated by, the waters of this lake. The conception embodied in this hypothesis appears to have been first grouped, though in a general way, by N. H. Winchell. It seems to afford the first satisfactory key to a rational explanation of the stratified deposits so generally found on northwardly sloping glaciated regions. Wide vi TV.—Die WEALDEN-BILDUNGEN DER UmGEGEenp von HANNOVER EINE GEOGNOSTISCH-PALAONTOLOGISCH-STATISTISCHE DARSTELLUNG von C. Srruckmann. Mit fiinf Tafeln Abbildungen. Hahn’sche Buchhandlung, 1880. HE author of this interesting work is already favourably known to our readers by ‘‘ Der Obere Jura,” reviewed in our volume for 1879. The Monograph now before us is a detailed description of the Wealden formation from the beds resting upon the Portland Limestone te the Hilsthon of the Chalk, near Hanover. The Wealden is divided into three stages, each forming a well-marked horizon of life. . J. The deepest is the ‘“‘Munder or bunte Wealden-Mergel,” representing the Purbeck beds of English geologists, and consisting of thick beds of limestone interstratified with beds of marl, in which are numerous specimens of Exogyra virgula, fossils are rare, the most abundant is Corbula mosensis, Buy. ‘They attain a thickness 282 Reviews—CO. Struckmann—The Wealden of Hanover. of 120 métres, and belong to the Upper Kimmeridge. Over these follow dark-coloured beds, twelve métres in thickness, of almost black marly limestone and shales. Rich in fossils, as Hrogyra virgula, Pecten concentricus, Gervillia obtusa, G. tetragona, Cardium eduliforme, Isocardia striata, Cyprina Brongniarti, Thracia incerta, Corbula mosensis, O. inflexa, C. alata, Turritella minuta, and rarely also Serpula coacervata. ‘These beds belong to the Lower Portland, and on them rest beds of the Upper Portland with few fossils, on which follows the Serpulit or Purbeck Limestone, consisting of very different strata, such as hard blue siliceous limestone, fine Oolitic limestone, clayey and sandy marls, with clay and sandstone, in which thirty species of organic remains are known. Serpula coacervata is found alone, and whole banks are filled with this Annelid—hence the name Serpulit. II. The Middle Wealden, or the group of Hastings sandstone, rests upon the Serpulit. It consists of thick beds of fine-grained, yellowish-white, or greyish durable sandstone, which for its ex- cellent quality has been employed in building Cologne Cathedral ; and other hard beds called Blaustein are used for road material. The thickness of the sandstone amounts to 500 feet, and some of its beds contain a rich fossil flora of thirty-three species. The following are the most abundant: Sphenopteris Mantelli, Pecopteris Geinitzii, Mantonidium Goepperti, Microdictyum Dunkeri, Hausmannia dichotoma, Anomozamites Schaumburgense, Sphenopteris Sternbergiana, Sph. Kurriana, Spirangia Jugleri. The Mollusca consist of moulds and compressed shells. The osseous remains of Fish and Saurians are rare, but single scales of Sphaerodus semiglobus and Lepidotus Mantelli are abundant. Our author has found at Bad Rehburg the foot-prints of Reptilian animals, Ornithoidichnites, similar to those described and figured by Mr. Beckles, from the Hastings sandstone of Bexhill, near Hastings. JII. The Upper Wealden or Weald Clay consists of dark grey or blackish, thin-bedded, friable sandy shales and marl; a quartzite rock with thin beddings of limestone, and an abundance of Cyrena, Cyclas, Corbula and Melania species, Melania strombiformis, Melania rugosa, Paludina fluviorum, and other beds with Cyrena species, Cypris, and Fishes’ scales. The Upper Wealden varies in thickness from 15 to 40, and 65 to 77 métres. The fauna of this Upper member of the Wealden is limited to a few species, as Mytilus membranaceus, Modiola lithodomus, Unio Menkei, many species of Cyrena, Corbula and Cyclas, with Melania harpaeformis, M. strombi- formis, M. rugosa, Paludina, Litorinella, Planorbis, Oypris Valdensis and two others, and the remains of Fishes, as Pycnodus, Sphaerodus, Hybodus ; of fossil plants only indistinct traces have been found. Under the lowest member of the Wealden, the Munder-Mergel, lies the Hinbeckhauser limestone, which belongs to the Upper Portlandian, representing a portion of the Upper Jura, and forming, it may be, passage-beds from the Portland to the Wealden. The Serpulit maintains by its organic remains the predominant character of the Wealden, so that it cannot be separated from both the upper Reports and Proceedings—Geological Society of London, 283 divisions. The entire Flora and Fauna of the Wealden formation has a Jurassic character, and the relations of the Lymneen and Brackish-water deposits of the Wealden with the Marine beds of the Portland, afford evidence of the alternation of conditions which prevailed during the close of the Jurassic epoch. The plates which illustrate the Monograph are beautifully executed. The number of species amounts to 146, of which there are— Plants 33 species belonging to 24 genera. Conchifera 62 rn 5 9 Gasteropoda 21 99 36 6 Annulata M Insecta 1 Crustacea 8 bp 90 2 Fish 18 0 : 8 Reptiles 2 % 33 2 146 51 The construction of the Paleontological table and catalogue of species is to be highly commended, seeing that it brings before the eye at a glance the most important points connected with the history of the Fauna and Flora of the Wealden and associated formations. One column contains the name and synonym of each species, another the literature of the same, a third their distribution in the Kim- meridge and Portlandian, a fourth in the Purbeck and Wealden, and a fifth contains localities and general remarks thereon. All students who aim at precise and concise methods in order to represent the ancient life history of any formation may well take a lesson from these tables. This work will be welcomed by all geologists who take an interest in the marvellous chapter of the Harth’s history to which it relates, and especially so to English naturalists acquainted with the correlated beds of the Wealden in our Southern Coast sections, which they can now compare with those in the neighbour- hood of Hanover. J. W. Soar @ see aS) Acris) ee @ @ senna) eS Se GxotocicaL Soorrty or Lonpon. April 27, 1881.—Robert Etheridge, Hsq., F.R.S., President, in the Chair.—The following communications were read :-— 1. ‘On the Precise Mode of Accumulation and Derivation of the Moel Tryfan Shelly Deposits; on the Discovery of similar High- Level Deposits along the Eastern Slopes of the Welsh Mountains ; and on the Existence of Drift-zones showing probable Variations in the Rate of Submergence.” By D. Mackintosh, Esq., F.G.S. The author commenced by giving a sketch of the progress of dis- covery connected with the Moel Tryfan deposits. He then described certain phenomena connected with these deposits, to which little or no attention has been devoted by other observers. After identifying the local stones, and indirectly local erratics, he traced the derivation of the far-travelled erratics which came from the N. and N.W. He drew particular attention to an extensive exposure of slaty lamina, 284 Reports and Proceedings— the edges of which have been bent by a force assailing the hill from the N.W.; and as these edges have been shattered so as to form parcels of slate-chips covered by, or rolled up in laminated sand, along with parcels of clay, he endeavoured to prove that a stranding of the floating-ice which must have brought part of the erratics (including numerous chalk-flints), will alone account for the pheno- mena. After describing patches of gravel and sand in other parts of Caernarvonshire, referring to the Three-Rock Mountain deposits in Ireland (which must have come from the N.W.), and briefly noticing the drifts on Halkin Mountain, Flintshire, he entered upon the main subject of his paper, namely, the discovery of an extensive series of marine drifts, including (besides deposits on flat ground) about twelve hillocks or knolls, consisting of rounded gravel and sand, and in at least two instances, containing gravel-pits with numerous shell-fragments. They extend along the east side of the northern part of the mountain-range which runs between Minera and Llangollen Vale, and are situated at levels between 1100 and 1300 feet above the sea. The gravel is largely made up of rounded Eskdale-granite pebbles, and during his last or fourth visit to the district, he found a large granite boulder on the axial summit of the ridge, about 1450 feet above the sea, showing a submergence of the mountain to at least that extent. He went on to assign reasons fur believing that the sea lingered longer at the level of the sand and gravel knolls than lower down and higher up, so as to allow time for the extra rounding of the pebbles, accumulation of erratics, and multiplication of Mollusca; for he could discover no reason for supposing that the mollusks which left the shells did not live on or near the spot in the littoral or sublittoral zone. He then described a small exposure of high-level rounded gravel and sand near Llan- gollen, and dwelt on the remarkable fact that the marine deposits on Moel Tryfan, Three-Rock Mountain (Ireland), Minera Mountain, and in Macclesfield Forest, occur at about the same altitude above the sea-level. After proposing a provisional classification of the drift-deposits of North Wales and the Pennine hills into zones, showing probable variations in the rate of submergence, he concluded by discussing the question, Whether the submergence was caused by the subsidence of the land or the rising of the sea, without venturing to express any decided opinion on the subject, but inclining to the former idea. 2. “On the Correlation of the Upper Jurassic Rocks of England with those of the Continent.” By the Rev. J. F. Blake, M.A., F.G.S. Part I. The Paris Basin. This was an attempt to settle the many questions of correlation arising out of the detailed descriptions given of the various localities in the Paris basin where Upper Jurassic rocks are developed, by a consecutive survey of them all; undertaken by the aid of a grant from the “Government Fund for Scientific Research.” In previous papers the names used for the great subdivisions and their boun- daries were adopted without material modification ; in the present such modifications were proposed as may bring the English and continental arrangements into harmony. Geological Society of London. 285 Five distinct areas were considered in this paper. a. The southern range; 6. The Charentes; c. Normandy; d. The Pays de Bray ; e. The Boulonnais. a. The Southern Range.—This is continuous from the Ardennes through the Meuse, Yonne, etc., to the Cher. In the Ardennes the “ Ferruginous Oolite” corresponds to our Osmington Oolite, and to the Lower Limestones and Passage-beds of Yorkshire, the under- lying “Middle Oxfordian” being equivalent to our Lower Cal- careous Grit. | Above comes immediately the Coral Rag with Cidaris florigemma; and the stratigraphical and paleontological break is constantly between the Coral Rag and Ferruginous Oolite when that occurs. The Corallian is a well-marked formation, though its character is variability. It is divisible generally into two groups—Coral Rag and Supracoralline beds, the latter usually being the “ Diceras-beds”’; but in the Yonne there is a great development of Diceras-beds below, associated with Cidaris florigemma and massive corals, which is gradually introduced in going west. This part of the series in the Haute Marne has been described as very different ; but the author did not at all agree with M. Tombeck’s stratigraphical determination, and considers the “ Oolite de la Nothe”’ no more than the continuation of the Supracoralline Diceras-beds, which he considers to uniformly overlie and never to underlie the Am. marantianus marls, which latter are Oxfordian. In fact nothing abnormal occurs in this Department. The whole series has a tendency to degenerate into barren lithographic limestones, in which distinctions are lost. The Astartian and Virgulian beds were traced through this range, the latter seldom showing any well-marked Pterocerian division, and the former being mostly connected with the overlying series. Above these are limestones hitherto called “ Port- landian,” in which two zones are constant ; but above all are vacuolar Oolites, which alone may be truly correlated with the Portland rocks of England. The whole of the beds in this range are eminently calcareous, a true clay being scarcely anywhere seen. b. The Charentes.—In these two Departments the lower portion is very calcareous, and the distinction of one part from another very slight; but the highest portion, both near Cognac and on the Ile _ d’Oleron, yields beds which may be paralleled with our true English Portland rocks. ce. Normandy.—The complete sequence has here been made out, from the true Oxford Clay of Dives to the Virgulian of Havre, and the similarity of the whole to the sequence in Dorsetshire is very remarkable. “The Trouville Oolite” is the exact representative of the “Osmington Oolites ” with the Nothe Grits below ; but the place of the Sandsfoot clay is taken by the true Coral Rag, whose right position in the Weymouth section is hereby determined. The Supracoralline beds are the sands of Glos, and the Astartian beds are the Trigonia-beds of Havre, which are the exact representatives of the “ Kimmeridge passage-beds.” d. The Pays de Bray.—Nothing below the Virgulian is here seen, and the commencement. of the so-called “ Portland beds ” was con- 286 Reports and Proceedings—Geological Society of London. sidered by the author to be at a lower level than it is placed by M. Lapparent, on account of the similarity to beds at Boulogne. The true Portland rocks occur as ferruginous sandstones with Trigonia gibbosa. e. Boulonnais.—The Houllefort limestone was correlated with the Osmington Oolite. The Coral Rag of Brucdale was considered equivalent to that of the Mont des Boucards, the so-called limestones of the latter place being Supracoralline. The Nerinzan Oolite and the Gres de Wirvigne represent the Astartian. “The higher parts of the series have been already correlated. From this study it was proposed—that the “Lower Calcareous Grit,” and almost all the Coralline Oolite should be placed in the Oxfordian series as the upper division, under the name “Oxford Grit,” and “‘ Oxford Oolite”; that the Corallian consists of two parts, the Coral Rag and the Supracoralline beds; that the Kimmeridgian should include the Astartian and Virgulian, the Pterocerian being a subzone; that the ‘Upper Kimmeridge ” and the Hartwell clay, with the “Portland sand,” should make a new subdivision to be called Bolonian, the northern and southern types being both represented at Boulogne, which may be divided into Upper and Lower; and that the true Portland limestone and the Purbeck be united into one group, as Lower and Upper Portlandian ; the fact of the latter being freshwater being paralleled by parts of the true Portland having that character. 3. “On Fossil Chilostomatous Bryozoa from the Yarra-Yarra, Victoria, Australia.” By Arthur William Waters, Hsq., F.G.S. The author gave a descriptive list of seventy-two pieces of Bryozoa belonging to the suborder Chilostomata, from a lump of clay obtained by Mr. Allen from the neighbourhood of the Yarra-Yarra River, The specimens are fragmentary, but in excellent preservation. There are eight species of Catenicella, a genus unknown in the fossil state until quite recently, when Mr. Bracebridge Wilson described twelve fossil species, none of which are known living; two of the Yarra-Yarra species still live in the Australian seas, and one of these also occurs in the Geological Society’s collection from Mount Gambier. Among the most interesting of all the specimens described by the author is a Catenicella, consisting of long internodes, with a double row of cells in each internode. The short-beaded Catenicelle now living have probably been developed from forms with long internodes. Jficroporella is also well represented by some interest- ing forms, which make it necessary to widen the definition of the genus. A very interesting Cellaria with subglobular internodes explains the Cretaceous fossil called Eschara aspasia by dOrbigny. Of the Chilostomata found in this deposit thirty-nine are con- sidered new, although this number may have to be reduced; nine- teen are now found living; seven correspond with those from the fossiliferous beds of Orakei Bay, New Zealand, described by Stoliczka; about twenty-three are found in the Mount Gambier formation. Of about thirty Cyclostomatous Bryozoa which occur in this deposit, at least seven are common to it and Orakei Bay. Besides the Bryozoa, Correspondence—MUr. C. S. Wilkinson. 287 the author has obtained many other organisms from this clay, and especially a large number of Foraminifera now in the hands of Prof. Karrer of Vienna. He estimates the total number of determinable species belonging to various classes at over 200. In treating of his special subjects the author adopts the principles of classification laid down by Hincks, Smitt, and other recent writers on living Bryozoa, which he regards as preferable in themselves, and also as facilitating the comparison of fossil with recent forms. COR za Sa—@ Nea NyCS a. nen GLACIAL BOULDERS IN SECONDARY DEPOSITS, SIDNEY, NEW SOUTH WALES. Mr. C. 8. Wilkinson, F.G.S., Government Geologist, Department of Mines, Sydney, N.S. Wales, referring to the occurrence of Glacial boulders in the “ Hawkesbury Series,” writes to Mr. R. Etheridge, jun., under date 10th February, 1881 :—‘‘ Here we have huge and small angular masses of soft shales embedded in pebble conglomerates and false-bedded sandstones. With these sandstones (Hawkesbury) are interstratified argillaceous shales, and the boulders are of the same material and contain the same fossils. It seems that during the deposition of the Hawkesbury Series, the rapid and changing currents which deposited the false-bedded sandstones, were at intervals suc- ceeded by quiet waters, from which the mud forming the shales settled down, probably during winter-time, when ground-ice formed. Spring-time following, the ice broke up, and drifting about broke up some of the newly-formed shales, and mingled the shale frag- ments with pebbles and sand brought by currents from the shores. The shale boulders are always found just above, or not far from the undisturbed shale-beds, thus :— B. NFS Z SEAN eu aa 2s oo Ss = = eR SSS ss =< S555 SSN In the sandstones just above the bed with angular blocks (A), are (B) small rolled flattish pieces of the same shale, the longer diameter inclined in one position, showing the direction of the ‘transporting currents at the time; some of the angular masses are curved, showing that they must have been in a ” soft condition, when torn up from the underlying shales. The principal fossils found in these are fragments of Plants—Phyllotheca, Thinnfeldia, Odontopteroides ; Fishes—Palaoniscus, Cheirolepis granulatus, Myriolepis Clarkii, and another, which appears to be new.” 1 Lower Mesozoic. B. 288 Correspondence—Mr. Whitaker—Mr. Whidborne. THE BAGSHOT BEDS OF THE BAGSHOT DISTRICT. Str,— Being greatly interested in the geology of the London Basin, and having just read Professor Jones’s paper on the Bagshot District (Proc. Geol. Assoc. vol. vi. No. 9), I at once turned to Mr. Herries’ article with the above title, on receiving the current Number of the GuotocicaL MaGazine, to be however “ brought up sharp” by the first paragraph (p. 171). The statement that “the only authority for the beds included in this area is Professor Prestwich, who... . has supplied all the in- formation about the district that is at present known,” quite astonishes me, at least as far as regards the words which I have italicized. No one is more ready to bear witness to the great value of Professor Prestwich’s many papers on the London Basin than I am, for no one, probably, has used them more; but that great authority on Tertiary geology would never claim such an exclusive right to the Bagshot District, the structure of which he made out and first described in detail. There happens to be an institution known as the “Geological Survey,” whose work consists in recording the details of the geology of these islands. Some of its officers (chiefly a former colleague. Mr. Polwhele, a Cambridge man) years ago surveyed the Bagshot District, and the result of their work has been published on the Geological Survey maps. Moreover, in the course of my own work on that Survey, I have a distinct recollection of running one of the so-called ‘‘ Horizontal Sections” across that district, and of having corrected the proofs of a Memoir (vol. iv. 1872) that gives a detailed description of the Bagshot Beds, and in which, I believe, the pebble- beds were for the first time described at any length. This note is not written with any wish to disparage Mr. Herries’ work; on the contrary, I welcome an addition to the ranks of our Tertiary geologists, and congratulate him on his enlargement of the local Bagshot fauna. My object is to caution young geologists against rashly assuming that they know everything that has been done in any district. That such an error should have come from the Woodwardian Museum is astonishing, as Professor Hughes, himself an old Survey man, could at once have enlightened his pupil. To conclude, I assure Mr. Herries that, should a second edition of the Geological Survey Memoir on the London Basin be called for, I shall make use of his paper and acknowledge his discoveries, to which I hope he may make many additions. GronocicaL Survey OFrtice, Wititam WHITAKER. 28, Jermyn Srreet, Lonpvon, 8.W., 11 April, 1881. PENTREMITES IN THE MIDDLE DEVONIAN OF DEVON. Srr,—Pentremites not being as yet in the British Middle Devonian lists, may I mention their probable occurrence in the neighbourhood of Torquay? I have placed two specimens, apparently of different species, in the hands of Mr. R. Etheridge, jun., who (with Mr. P. H. Carpenter) has kindly promised to examine and describe them. He pronounces them to be Blastoidea, though from their state of preservation the genus requires further investigation. One bears a superficial resemblance to Pentremites planus (Sandb.). A third specimen, also fragmentary, is in the collection of Mr. J. EH. Lee. CHARANTE, ToRQUAY. G. F. WHIDBORNE. GEOL. MAG. 1881. DECADETI. VOL. VIL. PLATE VIL. q Pacific Ocean. °38 [ oodword de Fig. a West Newman & C9 Lith. ; PY g. 1. Sdeatl Section across Ocean Basm . iy Sea. 2. Accumulated sediment. 3. Solid rock, converted at 4. to fluid by pressure. 5. Solid central mass. - Ki g. %. The Pacitic basin, showing encircling volcanos, trom Scrope. Fig. 3, Ideal Section as in Fig.1. but showing submarine lines of least resistance . THE GEOLOGICAL MAGAZINE. NEWER SERIES = DECADE ts WOR ViIiis No. VIL—JULY, 1881. @O2 EGAN E ASE “AME, EEE @ rere Sr. J.—Nore In Exprnanation or Prate VII., to ILLUSTRATE THE THuoryY oF SuBSIDENCE AND Euevation oF LanbD, AND THE PERMANENCE OF OckEAns.! By J. S. Garpner, F.G.S. Fic. 1 is intended to represent a section across an ocean basin. It is supposed that the combined weight of water (1) and sediment (2), acting upon an elastic layer of rock (3), compresses the fluid layer which underlies it (4), and forces it to escape laterally, and either to accumulate and partially solidify, thus raising the crust above; or, where the tension is extreme, and the resistance inadequate, to form fissures or vents. The continuously sustained pressure towards the centre of the basin constantly converts fresh solid into fluid, which escapes again and again, perhaps at intervals of centuries, causing fresh upheavals or eruptions, perpetually deepening the ocean basin. The relative mass of sediment to crystalline rock may be enor- mously greater, since its accumulation must have been increasing from the remotest ages. Fre. 2 represents the basin of the Pacific with its encircling chain of volcanos, and is after Scrope. Fre. 3 is an ideal section similar to that of Fig. 1; but showing in addition sub-marine lines of insufficient resistance. In the article, reference to one of the most striking examples of subsidence being directly due to weight of sediment was omitted. The constant influx of brackish water seen in our coal-fields, and the nature of coal, show beyond doubt that it was deposited at or about the sea-level, yet in the South Wales district the Coal-measures are 10,000 to 12,000 feet thick, with 75 distinct seams. IJ].—On tHe Genera Meris74, Surss, 1851, ann Dayz, Dav. 1881. By Tuomas Davipson, F.R.S., etc., etc. N his memoir “ Brachiop. der Késsener Schichten,” p. 17, Prof. Hi. Suess proposed his genus Merista, giving as its type the M. Herculea, Barrande, and at page 85 of the German edition of the general introduction to my work on British Fossil Brachiopoda Prof. K. Suess redescribes his genus, and in pl. ili. figures its spirals and shoe-lifter process; but neither the connexions of the spirals, nor their attachments to the hinge-plate, had then been discovered. Prof. Suess also includes in his genus Merista the so-called Atrypa tumida, Dalman (now the type of our genus Whitfieldia), whose 1 This Plate should have accompanied Mr. Gardner’s article which appeared in the June Number, see pp. 241-245.—Kprr. Geo. Mac. DECADE II.—VOL. VIII.—NO. VII. 19 290 T. Davidson—On the Genera Merista and Dayia. internal and differential characters were then likewise unknown. In our British Devonian rocks the genus Merista is represented by the Merista plebeia, or = scalprum; but although Mr. Glass has been able in several specimens to develope its spirals, he entirely failed to expose its loop, on account of the difficult nature of the limestone or Opaque spar which fills most of the specimens. Considering it to be very desirable that the interior character of this important genus should if possible be discovered, I wrote to my old and vaiued friends M. Barrande, of Prague, and to Prof. H. Suess, of Vienna, and requested them to kindly send me some specimens of Merista Herculea, that the Rev. Norman Glass might endeavour to work out the loop and the attachments to the hinge- plate, which had not been hitherto discovered; and thanks to his great skill, experience and patience, we are now acquainted with the whole characters belonging to the genus under description. The principal stems forming the spirals are attached to the hinge- plate a; from thence they proceed fora short distance into the interior of the shell with a very gentle inclination forward, and at 6 they are abruptly bent backwards at an acute angle towards the bottom of the lateral portions of the beak. From thence they form a broad rounded curve facing the bottom of the dorsal valve c, and after converging to about half their length, again divide towards the front, and thus form the first spiral coil. Again, at about half their length, at d, the principal Interior of the dorsal valve of Merista Herculea. lamelle widen and give off Developed by the Rev. Norman Glass. another lamella. ‘These Y lamelles converge from both sides towards the middle of the interior of the shell between the spiral coils, and after the two extremities have come into contact, the lamella thus formed proceeds in a straight direction for a short distance to near the hinge-plate, and then bifurcates and curves round on each side, forming two slender rings e. The anterior border of these rings being attached a little below the place where the converging lamella of the loop become united. The outer edges of the rings slope gently towards the bottom of the dorsal valve, and are rather less in width than the primary branches to which they are attached. The spiral cones are composed of ten or twelve convolutions, the number, however, varying in different specimens and at different stages of growth. The extremities of the spirals are directed towards the middle of the lateral portions of the shell. In the ventral valve, under the beak, are two roof-shaped plates fixed by their lateral margins to the medio-longitudinal region of the T. Davidson—On the Genera Merista and Dayia. Dom valve and with their narrow end fitting under the extremity of the beak. Prof. King compared these plates to a shoe-lifter process. With very small differences the loop of Meristella, Hall (M. arcuata, Hall), is similar to that we have described in Merista, and were it not that Meristella has no shoe-lifter process, it would not be possible to distinguish the two genera. Again, Whitfieldia (Atrypa tumida of Dalman) is distinguishable from both Merista and Meristella by the absence of those peculiar ring-shaped processes attached to the loop, and has instead only a short bifurcating process where in both the last-named genera the rings are formed. These three genera seem, indeed, closely allied, although each contains peculiarities by which it may be distinguished from the others. Genus Dayta, Dav. 1881. Type Zerebratula navicula, J. de C. Sowerby, Sil. Syst., pl. v. fig. 17, 1837. At page 191 of my Silurian Monograph, I say, “Surely this shell differs much, both by its external as well as its internal characters, from those peculiar to the genus Rhynchonella : so much so that it may hereafter be found desirable to propose for it, and similarly characterized shells, a separate generic or sub-generic desig- nation.” In 1867 I was acquainted with the interior surface of both valves, and described and figured in detail its very remarkable muscular and other impressions; but I had no idea that the shell was provided with spiral coils for the support of the labial appendages. During the month of March, 1881, the Rev. H. G. Day showed me some fine specimens of the so-termed Rhynchonella? navicula, and offered to send them to the Rev. Norman Glass, that he might see whether the shell was possessed of spiral appendages, and on the 22nd of the same month Mr. Glass wrote me: “I now send you two specimens worked out of R. ? navicula, showing entirely new spirals and loop,” and since all the interior characters are so distinct from what we find in other spiral- bearing genera, Mr. Glass suggested that I should propose a new genus for the shell under description. It is very probable even that we have in our British Silurian rocks other species referable to the same genus, but we are at present acquainted with Dayia navicula only, so that the generic characters may be taken from that as the type. Hxteriorly, Dayia navicula is elongated, oval or boat-shaped, broadest posteriorly —ventral valve very deep, convex, and arched, and keeled along the middle, beak closely incurved, dorsal valve slightly convex posteriorly, anterior half of ‘shell concave, surface smooth. In the interior surface of the dorsal valve a slightly raised ridge extends from under the hinge-plate to about half the length of the Interior of the dorsal valve of valve, and on either side are two scars Dayia naviewla. Developed formed by the adductor muscle. On the by the Rey. Norman Glass. . : . internal cast the place occupied by the 292 T. Davidson—On the Genera Merista and Dayia. mesial ridge forms a longitudinal groove, the muscular impressions being slightly in relief on either side. The sockets are widely separate. ‘The primary stems of the spirals are attached to the hinge- plate of the dorsal valve, and after extending parallel to each other for a short distance, bend at right angles abruptly towards the lateral portions of the beak, and form two large curves facing the lateral portions of the valve. On approaching the front they form four or five convolutions, which become smaller until they reach their terminal coil, which faces the middle of the lateral portions of the shell. Near the front the primary lamellz give off two processes, which converge and extend between the spiral coils in an upward and backward direction. After becoming united towards the middle of the shell, they are again prolonged in the shape of a single lamella, which proceeds upwards for a little distance with its extremity directed towards the hinge-plate. The spiral coils are therefore connected by a loop having a somewhat similar position to that described by Prof. J. Hall in Zigospira, but in this last named genus the spiral coils have their extremities facing each other in the centre of the shell, while in Dayia it is quite the reverse, the extremities of the spiral coils facing the lateral portions of the shell. In the interior of the ventral valve a mesial groove extends from the extremity of the beak to about the middle of the shell, and on either side, running parallel with the hinge-line, are two broad, rounded projections, at the outer extremity of which are situated the articulating tooth; under these are two obliquely placed or chevron- like, elongated, oval-shaped muscular scars, considerably raised from the bottom of the valve, these projecting parts forming correspond- ing depressions in the internal cast. We are therefore now, thanks to the incomparable skill of the Rey. Norman Glass, fully acquainted with the characters of the spiral arrangements of this remarkable genus, and which I name after the Rey. H. G. Day, in consideration of the important help he has always been ready to offer me in my investigations of the Silurian fossils with which he is so well acquainted. Placed by Sowerby in 1839 with Terebratula, by M‘Coy in Atrypa in 1846, with Hypothyris by Phillips in 1849, with Rhynchonella by Salter in 1859, I hope it has now found a resting-place in Dayiu, being entirely dissimilar from any of the genera above quoted. Dayia navicula seems con- fined to the Upper Silurian. It would be very desirable that the interior of the so-termed Werista ? cymbula should be examined, for it bears much external resemblance to Dayia navicula. From the different articles we have inserted in this year’s volume of the GrotocgicaL MaGazrne, it will be seen how very important it is to become acquainted with the loops and attachments of the spirals in the spiral-bearing genera of Brachiopoda. Indeed, it has been demonstrated from the admirable researches, so skilfully conducted by the Rev. Norman Glass, that it is impossible to feel certain as to the genus to which the larger number of the spiral-bearing species really belong until their interior details have been ascertained, and how fallacious it is to depend solely on external appearances. We are, unfortunately, not yet acquainted with the internal S. H. Scudder—New Carboniferous Insects. 293 character of the following Silurian British spiral-bearing species of Brachiopoda, and any one possessing duplicates available for that purpose could not serve science better than by placing them in the able hands of the Rev. Norman Glass:— Meristella ? angustifrons, M‘Coy, sp.; M. ? Circé, Barrande?; M. ? Maclareni, Haswell; J. ? crassa, Sow.; I. ? sub-undata, M‘Coy;