neh po Walls (GiliPis Cle 1D, WP ELD Ip BE J ° se (oe <= oo faa) | = Lu re, i x= HARVARD UNIVERSITY. Sturgis Hooper Professor MUSEUM OF COMPARATIVE ZOOLOGY Cer weyyyey MAS NAS Sy ve WW vu GEOLOGICAL SCIENCES LIBRARY Y go WS eile vy Sy Ae jee RN N WAN Kak 4). Sul \ e SWI WY Ss Maca Sia aly Ate Hei THE GEOLOGICAL MAGAZINE. NEW SERIES. DECADE II. VOL. II. JANUARY—DECEMBER, 1875. THE GEOLOGICAL MAGAZINE: Monthly Journal of Geology: WITH WHICH IS INCORPORATED hk GHOLOG ES NGS. CXXVII. TG CXXXVIII. EDITED BY HENRY WOODWARD, F.R.S., F.G.S., F.Z.S., VICE-PRESIDENT GF THE GEOLOGISTS ASSOCIATION 5 MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, PHILADELPHIA 5 HONORARY MEMBER OF THE GEOLOGICAL SOCIETIES OF EDINBURGH, GLASGOW, AND NORWICH; CORRESPONDING MEMBER OF THE GEOLOGICAL SOCIETY OF BELGIUM; OF THE NATURAL HISTORY SOCIETY OF MONTREAL; AND OF THE LYCEUM OF NATURAL HISTORY, NEW YORK. ASSISTED BY PROFESSOR JOHN MORRIS, F.G.S., &c., &c., ROBERT ETHERIDGE, F.B.S., L. & E., F.GS., &e. NEW SERIES. DECADE Iii. VOL. II. JANUARY—DECEMBER, 1875. LONDON: TRUBNER & Co., 57 anp 59, LUDGATE HILL. F, SAVY, 77, BOULEVART ST.-GERMAIN, PARIS. 2 1875, HERTFORD: eer! eeu ‘PRINTED BY STEPH] GES Om Bi AEs: PLATES. PAGE Vesa Species OLsOystenhy lin. cin. ok oeseek Sets celui ae ocak pede BO weliw Devonian bolyz0al urea nest ti Pa ee Se ep Nice aNene Guan rnts 33 ee ieee Graal tied one ce weal sate ae nice a real ere erty lunat cian eie 49 elon Weteoricrlaonstoundy 1 8/7(Orab: Oyvada kei cree eee comer cranes 152 vt Ni LMGEn a VOCE artes Basen nei eee Vika an eA inten meer cies 124 Senile AB OSS EA HORTA Oy ns nee Sacre Urael edn cones amore anes Wes 198 « VII. Sketch of Vulcano to Illustrate Mr. Judd’s Paper 9. ie se sae 99 MINA SHossileAmornnarda ma Rie octet atie Manel may oem oneal a cn) UN ee 291 ¥ VIII. View of Stromboli ... uu... URI Sa aise aN rad Wana ae 145 wae Nalin Se News Carbon iterous: Mossi se minis soley eee er ome amie aes 241 ~ IX. Section of Meteoric Iron from Toluca, Mexico (Autotype) .... ... 1 311 ¥ X. Tasmanites and Better-Bed Coal i. ck cece cesses see nee eee 387 »~ XI. The Meteorite which fell at Busti, Dec. 2,1852 (Chromolithograph)..... 401 Wa Ol OLetACCOUSEA TOmnNatd(e ature oneal an aed we a EMI SMEE Sas Pact cans 392 ae Rossileboraminitera trom Sumatra pa sains eee seamen er) cease 532 pa MVE Wossily Horaminiterarom: Sumatra 9) we sss |e. te esl eee eee 533 v XY. Incised Outline of a Reindeer from the Kesslerloch Cave, Thaingen, Schaffhausen on. cece cae eee SARS Gases MRR t edn SEAMEN nba th Tee 610 * To the Binder.—By an oversight two plates are numbered each Plate VII. and two are numbered each Plate VIII. (see above). The Binder is particularly requested to observe the titles of these plates, so as to avoid their being transposed or other- wise misplaced. ee J ie eat out LIST OF WOODCUTS. PAGE Map Illustrating the Volcanic Group of the Lipari Islands... o.oo 7 View of Panaria and surrounding Islands 0.0 we, cece cee cece tenes tee tees 9 Ruined Crater of Monte Sant? Angelo... 0. cee sues sees eee eaten ee 14 Section near Quaglia on the South-West Coast of Vulcano ook see sane 15 linremarinnyes Soman Cb ILE) ORV) Ges om om ceo am am om om oy ome 16 Muleancllovwathorts/Ehree Cratersenere. (ecu cd cee wane, | eect ences) | geen) cen 58 Section of Cone of Vulcanello in Sea Cliff... .... Rau aie ohak eae af 58 View of the Breached Crater of Campo Bianco... 0... wee sue vee ore 67 Sections of Quartz-trachyte Lava-streams at Porto delle Genti os 69 Diagrams of the Submergence of Land in Isle of Man ..... Oe aaa Opa Sea 83 iPamorathewclands ot a\iul canopy seme ewes ee aii tan se nes AAR atau rete 110 Diagram Illustrating the Sediment Theory of Drift... _ ..... Ba tare usher oe ns 171 Three Fossil Fruits, Cardiocarpus elongatus; C. bisectus; C. samareformis : and Welwitschia mirabilis, from Dana’s Manual of Geology... ..... ..... 179 Section of the Red Rocks near Birmingham... ce, fee ees oe 196 Wiewlotethe? Active, Cratersot cotroniyol igi e iene sumer: ues sna 208 Section through the Island of Stromboli wn. on ek cee ce tee cee 210 Planvotatheplslandof lschiaes. se i cscy eect ease mit g bees Myerson areca 248 Monte Rotaro with Monte Tabor... 0. cece cee eee cess ee teeee seen eee 253 ‘DheiCraterslake chliarodeleBacnorslschiay Wren cccdye cena) Weer cscs uess een 264 Island of San Stephano seen from the South 2... os Peeps 299 The Headland Monte della Guardia in Ponza ., ce, sees sete sete settee 300 Western Spur of Monte della Guardia ww. ad a lees aa SOIL Blocksof CaillesironvineearisnC ollechionen 2 men ee ere te tee ogee ee 369 MreteOnitenOmmATIMCT ess hence un et), Verne Weg Manian y Pamir tieccs Sart Ratee tak 402 MiaeramyotelakerGlaciens. atin asso nise eye ce ean eet ees ae ae 438 Wilews olsaglia leen@ tle timer cers, ter diese dane? Ons den satay ene eae cee 43 Machine for Me) timemlcommammtcy ges oct cscs cer pach Rap Gee Rr ccc avs 441 Diagram Tlustrating the Welocity of Tce 2 cc ce ee cece 1 449 Hlood@lievelcor the=Evninile mimes etuure: ibe me rae Med os etna 444 Section of Hirwaint Commoneeg ine) eq sl (se ee eos sock) sass ures 445 Diagrams Illustrating a Stream of Water in an Artificial Channel... ..... _..... 446 Diagrams of different effect of Depth and Velocity 0.0. cee san elie 447 Vill List of Woodcuts. Diagram showing Width of the Mississippi at various points... sine son 448 @ourseror the miversAmazon emer m ee Peewee, yess gerne ie evmmie ne center 448 Actual Junction of Tributaries of the Mississippi at acute angles ou. uae 449 SEUNG: OED OUNCE! ANG NEAT IG | Gees ok pe eR om emcees oe cet 449 AlitematestHeadlandsrards Coombes (icc. acca teceuitc: mule nee ne meee nS 450 Diagram of the effect on Velocity in relation to different quantities... ... ..... 450 Diasramyonthe River Danube | icc sce sccuemets ase al Seieratiphe eres 451 Angular Junction of Side Stream with Main River oo, cess cence cuss eee 451 Mount Mabon, trom a phobopmap icra ters) age ese amino a eer a te reese 452 Diasramyors Outline ot eM ormiainy eerie Maen mre meee ace ier eae mere re: 452 ish Baek, EU: soi. svete reteiieeaen (meres neers Ses ittiace lalpestee tapes Bais) db etieay Merona 453 Nection ois Misheback etal amet cuaeceter crac tee dere erie ater as ier nee eee 453 Sectionyotie sell or (Glacial GO actait een ere eee eee pen co eee 454 SectronsoL al wo Hall se se tespeee reteset onan a eee valy encom a aici enee 454 Outline of Sand Hills near Leighton Buzzard 0... cece cesses seers ness tees 454 Beclesbourn Glen: \ i. jactee ume: mp ares tate nie ee eee nea ae 455 iHolkestonesin'the PluvialéPerioduses ere ames. ere ce ure ene 456 Bicclesbourn! Glen in) the Pltuvial Period. ciel eae eee eee 456 Section showing Surfaces removed by Denudation 2. i, sesse cscs cents eee 457 Gorge through Chalk Hills being formed 0. ne cece coe Sr ny cr 457 Gorzesthronshy Chalk iallssormed seguir Be Ween) aH) ———_ T.—ConTRIBUTIONS TO THE StuDY OF VOLCANOS. By J. W. Jupp, F.G.S. INTRODUCTION. YHE study of the nature and causes of the phenomena of volcanic activity, which for some time previously seemed to have almost fallen into abeyance, has during the last few years attracted the attention of many patient observers and earnest thinkers. In proof of this statement, we need only point to the valuable essays upon the subject which have recently been published by Dana, James Hall, Le Conte, Shaler, Hilgard, Sterry Hunt, and others in America, and to those by Mr. Mallet, Captain Hutton, the Rev. O. Fisher, and others in this country. But while we cannot but regard with pleasure the revival of research in this important department of geological inquiry, it will be well not to overlook a source of danger in the direction which it seems to be almost exclusively taking. The earliest speculations on the subject of Vulcanology belong to the domain of Cosmogony, rather than to that of Geology. With the smallest basis of knowledge of the actual phenomena of volcanic activity, theorists sought to build up “Systems of the Earth,” in which recourse was freely had to igneous action to accomplish all such operations which were felt to be necessary for the removal of the difficulties of their hypotheses. During the latter portion of the last century, however, the accurate study of the phenomena presented by active volcanos was com- menced by Sir William Hamilton, Dolomieu, and Spallanzani, in that district of Hurope where they are most admirably displayed, namely, Southern Italy. A little later Hutton, with his able co- adjutors and exponents, Sir James Hall, Playfair, and Macculloch, sought to apply the phenomena of active volcanos to the explanation of the appearances presented by those ancient rocks, in which the signs of igenous action were clearly visible; and in no country could they have been more favourably situated for carrying on such researches than in Scotland. In the two schools which we have thus noticed as taking their rise at no distant date from one another, in Italy and Scotland re- spectively, we have an indication of the two branches of inquiry into which the study of Vulcanology must necessarily tend to flow. A suggestive comparison may be draw between the investigation of DECADE II.—YOL. II.—NO. I, 1 2 J. W. Judd—On Volcanos. volcanic action on the earth and that of vital action in the human body. In either case our opportunities for direct experiment are comparatively few; and in both, therefore, we are compelled to resort to indirect means in order to attain the desired results. To acquire an understanding of the nature and causes of vital action, one class of inquirers—the Physiologists—study the phenomena presented by the living body as it performs its various functions ; while another class—the Anatomists—examine, in the dead subject, the machinery by which the various processes are carried on, and the structure which is built up by their operations. As in Biology, so in Geology, we have inquirers investigating, by the aid of mathe- matics, physics, and chemistry, the movements, products, and other attendant phenomena of volcanic activity—the Physiology of the Earth; while others devote themselves to researches connected with the position and relations of the masses which constitute it—the Harth’s Anatomy; and these latter find in the ruins of extinct volcanos, and the intrusive masses connected with them, alike the mechanism and the products of igneous activity. There is, indeed, this difference between the study of the Anatomy of the Microcosm and that of the Macrocosm—that, while in the former we are able by dissection to examine the structure of its parts at our will, in the latter we can only attain our object by taking advantage of those revelations of its interior, effected by the conjoint action of sub- terranean movements and surface denudations. It will not, perhaps, be doing violence to our comparison, if we venture to push it one step farther, and to remark that, as the pro- gress of Biology has in recent years been very greatly furthered by the microscopic study of the minute tissues of which organized bodies are composed, so a new department of Geology has arisen—Micro- petrology, the homologue of Histology—which promises equally to advance our knowledge of the origin, nature, and succession of those series of changes which constitute the “life of the globe.” The study of the internal structure of rocks by the aid of the microscope, the initiative to which was given in 1858 by Mr. Sorby’s remarkable paper “On the Microscopical Structure of Crystals, indicating the Origin of Minerals and Rocks,” has recently, in the hands of Zirkel, Forbes, Vogelsang, Rosenbusch, Allport, and a host of other enthu- siastic observers, made most prodigious strides, and promises to afford the most valuable aid to geological research. The first attempt at a general treatise on Vulcanology was that cf Mr. Scrope in 1825. Unfortunately, while following out the two lines of inquiry which we have just indicated, and attaining many important results, the correctness and value of which have been established by subsequent investigations, the author permitted him- self to be drawn aside from the true paths of geological inquiry into the speculations of Cosmogony. No one was more conscious of this blemish of his work than the author himself, as was shown by the subsequent publication of his well-known work, ‘The Geology and Extinct Volcanos of Central France,” in which this error is most carefully avoided; and also in a second edition of his general treatise, J. W. Judd—On Volcanos. 3 in which the speculative portions are omitted. In the latter he has confined his researches within the true limits of geological inquiry, and the work remains the most complete and masterly treatise on the subject which has yet been produced. In the “ Principles of Geology ” due weight has been assigned by Sir Charles Lyell to igneous action in producing the existing features of the globe. In order to illustrate the manner in which the phenomena presented by the rocks of the globe are capable of explanation by the operations now taking place on its surface, both the “ physiological” and ‘‘anatomical”’ branches of the subject are treated with that force of argument, that justice of illustration, and that felicity of language, with which every geologist is familiar. Mr. Dar- win’s works on South America and the Volcanic Islands of the Atlantic may be regarded as additional and very valuable illustrations of the “ Principles of Geology,” the work which, as he has himself assured us, first led him into those lines of research in which he subsequently attained such preeminent success. — During the last fifty years innumerable very valuable contributions to both branches of the science of Vulcanology have been made. Geographers and travellers, physicists and chemists, mineralogists and petrologists, have accumulated the most valuable details, illustrat- ing the nature and distribution, the characters and materials, the phenomena and products of active volcanos. Humboldt, von Buch, Hoffmann, Junghuhn, and others have occupied themselves with their general features; Gustave Rose, Abich, Scacchi, vom Rath, and Fuchs, with the rocks of which they are composed ; and Daubeny, Deville, Fouqué, and Janssen, with the chemical operations taking place within them. Equally valuable have been the labours of those physical geologists who have supplied us with detailed descriptions and accurate maps, illustrating the features presented by the olderigneous rock-masses and their relations to the stratified deposits with which they are associated. Foremost in this category we must mention Charles Maclaren, who at so early a date described with admirable clearness the volcanic rocks in the neighbourhood of Edinburgh, ‘The maps and memoirs of the Geological Survey, especially those relating to North Wales and Central Scotland, also afford very valuable illustrations of the older volcanic rocks. In some of the latest researches on Vulcanology, to which I have referred at the commencement of this article, however, a tendency is shown towards abandoning these safer methods of inquiry, based on the doctrine of Uniformity, and reverting to the earlier methods—in effect, to the substitution of Cosmogony for Geology. In the ingenious theory elaborated by Mr. Mallet a still bolder course is adopted, and, almost entirely ignoring the results of geological inquiry, this author endeavours to build up on the foundation of the nebular hypothesis of Laplace, and by the aid of those laws of Physics which he regards as fully established, a system of “ Vulcanicity.” Had the Physical Sciences attained their final stage of development, Mr. Mallet might perhaps have been justified in taking such high ground as he does 4. J. W. Judd—On Volcanos. in dealing with one of the natural sciences; but when we find that not a few of the data and principles of calculation on which he relies are disputed by authorities of equal eminence with himself in their special departments, geologists may be forgiven for thinking that the tone assumed by him in dealing with this subject was scarcely warranted. Nor is their confidence in the value of his speculations increased, when they find him arriving by means of them at con- clusions totally at variance with the clearest results of geological observation,—such, for example, as that ordinary explosive volcanic eruptions did not take place during the Paleozoic period ! We are far from denying the advantage of inquiries and specula- tions of this character. It cannot but be of interest to the student of Geology, and at the same time calculated to afford him suggestions in the carrying out of his investigations, to see how far the con- clusions at which he has arrived by direct observation can be made to harmonize with the hypotheses based on the latest results of Physical Science. But, as these latter are continually undergoing modification and development from the progress of research, we must ever be on the guard against allowing such theories to have undue weight, or being supposed capable of replacing the methods of geological inquiry, at first so well developed by Hutton, and afterwards so clearly illustrated by the labours of Lyell, Scrope, and Darwin—methods based on the principle that the explanation of the phenomena of the past can only be obtained by a study of the operations which are still going on around us. __ In giving a series of sketches of the structure and phenomena of some of the most interesting volcanic districts in Europe, we shall endeavour, as far as possible, to avoid all subjects of a purely specu- lative character, and it will be our chief aim to direct especial attention to those features which suggest analogies with the volcanic formations of former geological periods, and appear to be calculated to throw light on the nature and succession of those operations by which these latter have been originated. While dwelling, however, upon the more general features of geological structure and igneous action, in our descriptions of the several districts, we shall endea- vour not to lose sight of any of those results of chemical, minera- logical, or microscopical research which appear to throw light upon the subjects of our studies. Our object, in short, will be to confine these studies within what we have indicated as being the most im- portant and legitimate paths of geological inquiry,—namely, the investigation of the structures and operations of extinct and active volcanos, with a view to arriving at the laws which have governed the developments and manifestations of igneous forces, alike in past geological periods and during the existing epoch. I.—Tue Lirarr Isnanns. There is certainly no district in Hurope, and perhaps none in the whole world, which affords such beautiful illustrations of the phe- nomena of volcanic action, and at the same time offers such re- markable facilities for their investigation, as the little group of J. W. Judd—On Volcanos. 5 Mediterranean islands lying between the Phlegrean Fields of Calabria and Sicily. Htna, it is true, presents us with the monu- ments of igneous forces acting upon a grander scale, and Vesuvius excites a livelier interest by its historical associations, its fossil cities, and its proximity to a splendid capital; but neither of these volcanos can vie with those of the Lipari Islands, either in the remarkably suggestive features of their structure, in the permanent and interest- ing characters of their operations, or in the variety and beauty of their products. Nor have the advantages here presented to the geologist been neglected by the pioneers of our science. Sir William Hamilton, Dolomieu, Spallanzani, and Scrope have, by the study of their active and extinct vents, contributed much towards our knowledge of the modus operandi of volcanic forces; Hoffmann, Allan, and Abich have described the interesting rocks of which the Lipari Volcanos are composed ; while the last-mentioned author, with Daubeny, Charles Ste.-Claire Deville, Fouqué, and Janssen, have investigated the nature and products of the chemical actions going on within them. The geological interest attaching to the volcanos of the Lipari Islands has induced the French Academy to send out, on several different occasions, commissions charged with their investigation. _ Many undertakings, which in other countries require an appeal to the resources of the Government, are in our own safely left to in- dividual enterprise ; and Mr. Scrope, who more than fifty years ago experienced and called attention to the advantages which the Lipari Islands offer as objects of study, has furnished several students of volcanic geology, myself among the number, with the opportunity of carrying on researches in them. As no general sketch of the geology of the Lipari Islands has been published since the admirable, but now somewhat obsolete, work of Friedrich Hoffmann, which made its appearance in 1884, it has been suggested to me that an account of some of the results of my own studies there in the spring of 1874 would be of interest to the readers of this Journal. The sketch which we are here able to give must, of course, be mainly descriptive, and it will be impossible, within its limits, to enter into detailed discussions of those numerous problems of volcanic geology, towards the solution of which this interesting group of islands affords such valuable materials. The name by which this group of islands (a Sketch-map of which is given on page 7) is generally known is derived from its central, largest, and most populous member. An earlier designation, and one which is still often applied to them, is that of “the Holian Isles,” and there is a curious interest attaching to its dérivation. The original Eolus appears to have been a prince or chief of the Greek colony which inhabited these islands, and, being probably a man of superior intelligence and shrewdness, he seems to have ac- quired some fame by employing the two active volcanos of his dominions as natural “ weather-glasses.” Stromboli is still believed by the Liparotes to respond, like a barometer, to changes of atmo- spheric pressure; and the characters of the vapour-clouds which rise 6 J. W. Judd—On Volcanos. both from it and from Yuleano are, unquestionably, indicative of hygrometric variations. The power of forecasting events is, by the vulgar mind, often confounded with that of bringing them to pass ; and the hero or prophet of one generation becomes the demigod of the next, and the deity of succeeding ones. Hence it is not sur- prising to find Kolus invested, in later mythologies, with the dignity of “God of the Winds.” Such is the account of the origin of the name as given by some eminent Italian scholars; but those who have experienced the fierce and sudden storm of the seas surround- ing the Holian Isles may perhaps be disposed to adopt a simpler explanation of the identification of these islands with the blusterous deity. The group of the Liparis consists of seven inhabited islands and ~ a great number of small islets and rocks. The whole of these are entirely composed of volcanic materials, and two of the islands, Vulcano and Stromboli, contain still active vents; in the others, craters and lava-streams, in various stages of freshness or ruin, testify to the former scale of igneous operations within them ; while active fumaroles and hot springs indicate forces not yet wholly subdued. In describing the geological structure of the Lipari Islands, it may be well to notice the several rock-masses in what appears to be their chronological order of formation. As in the case of the classical district of the Auvergne, this order of succession in the volcanic outbursts is sufficiently indicated by the varying extent to which the different formations have suffered from denuding forces, and the relations which they everywhere maintain towards one another. A careful study of the district seems to prove that at one time there existed a great central volcanic mountain, now, like the volcano of Santorin in the Adgean sea, in great part submerged, and reduced to a few islands representing the crater ring. Radiating from this great central volcano, three fissures appear to have been originated, and at various points along these fissures volcanic cones were thrown up, and numerous eruptions took place. Finally, the apparently dying energies centred in this volcanic district have become localized at two almost extreme points, giving rise to voleanos so opposite in their mode of action and in the characters of their products, as to suggest questions of the highest interest to the geological inquirer. It must of course be borne in mind that these three periods of volcanic outbursts, though sufficiently well characterized for the purposes of geological classification, are merely different phases in the display of the same igneous activity; and that, as they do not appear to have been separated by periods of quiescence, they are by no means sharply and clearly divided from one another. While Stromboli stands unrivalled as an example of a volcano in the phase of permanent moderate activity, offering facilities for quiet study, (of which the distracting sensations of overwhelming grandeur and personal danger can scarcely fail to deprive the ob- server, in the cases of volcanos in more violent stages of eruption), Vuleano furnishes us with a most admirable and easily accessible J. W. Judd—On Vanes Norvtx. Fie. 1. MAP stromboluzn0 4, ILLUSTRATING THE VOLCANIC GROUP OF THE wee LIPARI ISLANDS, Stromboli 0). Based on the French Admiralty Chart of Dumondeau., i ee) A ca fj f @ Active craters, i ) Extinct craters, —-—=<—-= Probable lines of fissure. / ld 4 Alicudi (2,172 ft.) ales To Ustici, —— -@ Filicudi (2,598 ft.). Dogs : ; SLE. Submerged Tract. ZZ@SE_b 1. Panaria(1,430 ft.). Vee Vo 2, Basiluzzo. Zep =, 3. Dattilo. LSECIEX # 4, Lisca bianca. ; a 72 S 5. Bottaro, Salina 7 LX aD 6. Panarella. (3,125 ft.). 7 7 7 7. Formiche, va 4 8. Lisca nera. 2 Oe 7 + Submarine fuma- 0-—~9@(- / role, ca BANA (6 J Lipari (1978 ft.). "Co \ Vulcano (1,601 ft.). To Capo di Milazzo. SouTu. 8 J. W. Judd—On Volcanos. crater, in the Solfatara condition, remarkable alike for the abundance and variety of its gaseous emanations, and for the beauty of the minerals which result from them, but at the same time subject to paroxysmic outbursts on the grandest scale. In all the islands we find the most beautiful illustrations of the constant shifting of centres of volcanic action along lines of subterranean fissure, and the most instructive examples of the wide diversities in the charac- ters of lavas, from those of the most highly silicic or acid composition to those of the most ferruginous and basic, and from the highly crystalline varieties on the one hand, to perfect glasses on the other. The analogy between the relations and order of formation of the great central volcano and the surrounding lines of volcanic vents in the Lipari Islands on the one hand, and the ruined volcanos of Central France, namely, the Mont Dore, the Cantal, and the Mezen, and the long chains of “ Puys” surrounding them, on the other, must strike every student of volcanic geology, and is a sufficient justification for our adopting the following order in our descriptions of the Lipari volcanic formations :— I. The great central volcano now almost entirely submerged, and of which we have only a few highly ruinous relics in Panaria and the surrounding islets. II. The chains of extinct and more or less degraded cones which constitute the larger part of the other islands. III. The very remarkable features and the interesting products of the still active or but recently extinct vents in Stromboli, Lipari, Vulcano and Vulcanello. IV. Our sketch of the district will appropriately conclude with descriptions of the remarkable phenomena exhibited by Vulcano and Stromboli respectively, and a history of the changes which have taken place within them during the periods concerning which we have authentic records. . 1.—First Period of Volcanic Activity in the Lipari Islands. The submerged tract (see Map, p. 7) which marks the probable site of a great central volcano in the Lipari Islands is composed— judging from the nature of the islands and rocks which still rise above the sea-level—of various materials of the trachytic class. These occur in the form of tuffs and agglomerates, of lava streams, and of solid masses of enormous dimensions, which appear to have been extruded in a viscid or pasty condition in the manner so com- mon with rocks of théir class. In the disposition of the materials in this central group of islets the student of volcanic geology at once recognizes those forms so characteristic of partially submerged and greatly denuded crater rings, which are so well exemplified in the ruined volcanos of San- torin in the Algean Sea, and of Ventotiene, one of the Ponza Islands (vide Scrope’s ‘ Volcanos,’ 2nd ed. p. 209). As shown in the sketch (Hig. 2), the inclined streams of lava, with their alternating beds of tuff, which doubtless once constituted the sides of a great cone, gradually built up by their successive emission, now exist only as Se | Ge Se (Naess ae yo. — Bete Cele oo SS See c Ti : Lr ——— J. W. Judd—On Volcanos. — 10 J. W. , Judd—On Volcanos. isolated fragments, such as Basiluzzo, Dattilo, Bottaro, Lisca nera, and Lisca bianca, each of which presents the peculiar wedge-like forms so characteristic of the denuded segments of old crater rings. Some of the lava masses in this tract, especially those of Basiluzzo and Dattilo, exhibit a rudely columnar structure. Panaria was sup- posed by Dolomieu to afford traces of an old crater in its central valley, but this point seems to me, at best, very doubtful. The great mass of highly crystalline rocks of which this island is composed is probably, like the central trachytic bosses of Astroni and Rocca _ Monfina, to which it presents striking resemblances in chemical and petrological characters, the product of an outburst of highly viscid materials which have accumulated immediately around the volcanic vent, instead of flowing as lava streams; this result being due, as in the analogous examples of the domitic puys of Auvergne, to the imperfect liquidity of the rock at the time of its emission. The lavas of the central volcano of the Lipari Islands have long been celebrated for their remarkable petrological characters. Com- posed of one or more species of felspar, with hornblende or mica, and some free quartz, their highly crystalline character led some of the early observers to class them as granites. On the other hand, that they were erupted near the surface, and in many cases under no very great pressure, is shown by the glassy and pumiceous cha- racters which portions of their mass assume. Hence they have been described as exhibiting all the transitions from granite to pumice. In their chemical characters these peculiar rocks offer points of as great interest as in their petrological structure. From true or ordi- nary (“quartzfrei’’) trachytes, with a specific gravity of 2°6, and an average per-centage of silica of about 62, they graduate in one direction up to the rocks designated by Abich as trachy-dolerites, with a specific gravity of 2°75, and a silica per-centage of 57; while in the other, by exhibiting a smaller specific gravity with a higher per-centage of silica and some free quartz, they approach the quartz- trachytes. These extremes of composition are exhibited in the rocks of Lisca nera, Lisca bianca, and Dattilo, on the one hand, and in those of Basiluzzo on the other. They are illustrated by the follow- ing analyses made by Abich :— Lava of Lisca nera, etc. Lava of Basiluzzo, etc. Speciticuoravity © ses eee nne ss meaO2 2-4008 SUR, 9 Ado ong 00d ct co, an AHN 67:09 Alumina 506 400 «na cnn cog—Cé«SN 17°36 Oxides of Iron and Manganese... 6°71 0°81 Lime Scie Ressicaene eel aes Maes mene se 72 1:23 WESC) o55 can 009 aeons 7:02 1:20 Soda coo 000s sds co—s«) HE 4°10 TRAIN 500° coo 000 ooo ~«no~ coos) Tee 8:27 Two specimens of trachyte taken from Panaria were determined by the same geologist to have specific gravities of 2-6754 and 2-7225, and per-centages of silica of 64:37 and 61:39 respectively. A third variety from the same island was found to closely approximate to the rock of Basiluzzo in composition. J. W. Judd—On Volcanos. iii From these analyses it appears that the central volcano of the Liparis, so far as its rocks are open to our observation, consists of various trachytic materials approximating to, but never reaching, the basalts on the one hand, and the quartz-trachytes on the other. The only signs of volcanic activity still exhibited by this vast central volcano, the antiquity of which is sufficiently indicated by its greatly denuded and altogether ruinous condition, consists in an insignificant sub-aerial stufe, in the island of Panaria, and a sub- marine fumarole, situated in the channel between Lisca nera and Lisca bianca. The occurrence of this still active vent of volcanic energy in the midst of the submerged and altogether ruined crater of the Liparis may be paralleled with that which exists in the midst of the similar crater of Santorin, which is, however, in a far more violent stage of action, and has given rise to eruptions that have attracted so much attention during the last few years. The sub- marine fumarole of the Liparis, which is opened in the white pumiceous rocks of the sea-bottom at a depth of 25 feet from the surface, pours forth considerable quantities of carbonic acid and sulphuretted hydrogen gases, the bubbles of which produce a beautiful effect in rising through the clear blue Mediterranean waters and cause the sea to appear in a state of ebullition. As an amus- ing instance of the power of imagination, we may mention that in a recently published and popular book of travels, the authoress describes in very graphic language the sensations of scalding which she experienced on thrusting her hand into this “ boiling water” ! 2.—Second Period of Volcanic Activity in the Lipari Islands. Turning our attention to the second period of igneous activity, which has been characterized in the Lipari Islands, we find that we shall have to refer to it by far the larger portion of the rocks of the group. Constituting the entire masses of the islands of Salina, Filicudi, and Alicudi, they form also the basis of those of Lipari, Vulcano, and Stromboli, in which, however, they are to some extent ‘buried and concealed under the products of the third and latest period of eruption. The materials ejected during the second period consist of lavas and the agglomerates, tuffs, and ashes derived from them—the accumu- lations of fragmentary matters generally greatly preponderating in quantity over the solid rocks; which latter, nevertheless, in conse- quence of their greater power of resisting denuding forces, often constitute all the most prominent and conspicuous parts of the islands. Nearly the whole of the lavas of the second period belong to the trachytic class, but there appears to be a constant tendency in the Jater formed of them to approximate towards the rocks of the basaltic type. This gradual change in the character of the lavas is well exemplified in the series of successive cones and craters so well displayed in the southern part of the island of Vulcano. As an ex- ample of the composition of the lavas of this period, we may instance the rock constituting the central mass, and forming by far the larger 12 J. W. Judd— On Volcanos. part of Stromboli, which Abich found to possess a specific gravity of 2-7307, and a per-centage of silica of 61°78. The lavas of the second period may be divided into three classes, examples of all of which may be found in each of the islands in which the products of this period are developed. A.—The most abundant of these varieties are the ordinary trachytes, usually rendered of a highly porphyritic character, by the dissemination through their mass of scattered crystals of sani- dine, but occasionally compact and granular in texture, and sometimes exhibiting banded and ribboned structures. These old trachytes are often found assuming red and purplish tints on weathering, and then exactly resemble in appearance, as they also do in chemical constitu- tion, many of the “‘porphyrites” of ancient geological periods. . B.—A somewhat less common but very beautiful form assumed by these trachytes is that of a dark grey or almost black granular base, through which crystals of sanidine are diffused ; by the passage of the granular or stony base into a more or less perfect vitreous condition, the rock assumes the well-known characters of a “ pitch- stone-porphyry.” This rock—of which beautiful examples are found in the lava-streams issuing from the old ruined crater of Monte Sant’ Angelo, constituting the highest point of Lipari, above Tivoli in the same island, and also near La Malfi in Salina—forcibly recalls to the mind the precisely similar varieties of rocks, so abundant at Beinn Shiant and the Scur of Higg in the Western Highlands of Scotland. C.—The third variety of the Lipari trachytes finds its exact analogue in the celebrated Arso lava of Ischia, which has been so admirably described by Fuchs. Its base is similar to that of ordinary trachytes ; but scattered through its mass in greater or less abundance oceur crystals of augite, mica, and magnetite, with grains of olivine, - which impart to the rock a more basic composition, and cause it to approximate towards the trachy-dolerites of Abich. Trachytes of this third class are found in Monte Rosa in Lipari, near Rinella in Salina, and in great abundance and variety in the southern part of Vulcano. One of the most interesting features of the Lipari Islands is the series of wonderful changes which their rocks have undergone, in consequence of the passage through them, subsequently to their eruption, of acid gases and vapours. By this means the hard and crystalline trachytic lavas of Lipari have, over very large areas, been reduced to a soft, white, earthy material, to the eye exactly resembling chalk ; in other cases they have assumed the carious and open crystalline texture of the “alaunstein” of German petrologists ; while in others again they are found less altered, and presenting the most beautiful variegated tints. Similar changes may be seen taking place in the lava of Olibano, where it issues from the crater of the Solfatara of Naples, but in Lipari they are far more complete in character, and on a much grander scale. The accumulations of fragmentary materials which constitute the larger portions of the mass of the Lipari Islands exhibit also many J. W. Judd—On Volcanos. — 13 varieties of character. It is interesting to notice that, while we have no proof from included shells or other marine remains of any part of these tuffs having been accumulated under the sea, but, on the contrary, find the clearest evidence, in the leaves and stems of terrestrial plants which they so abundantly yield, that a part at least of them were accumulated under sub-aerial conditions, yet they almost always exhibit some signs of stratification, and not un- frequently, indeed, are very finely laminated. In explanation of this circumstance, however, it is only necessary to point to the materials, certainly of sub-aerial origin, which cover Pompeii, and to the ashes ejected from Vesuvius in 1872 and still enveloping its cone, both of which exhibit an unmistakably stratified or lami- nated character. The remembrance of these facts may serve to prevent us from too hastily inferring the sub-aqueous origin of volcanic tuffs occurring among ancient geological deposits, from their stratified appearance. Of beautiful examples of false-bedding, unconformable stratification, and similar appearances due to the action of local causes, innumerable interesting examples might be adduced from among the deposits of fragmentary volcanic materials in the Liparis. In respect to their structure, these accumulations sometimes present the character of agglomerates made up of angular blocks, including some of vast dimensions, of all the varieties of lava before mentioned, mingled with volcanic bombs, scorie, lapilli, and ashes. At other times they are composed of materials of more uniform character and constitute tuffs; while not rarely they are made up. of fine volcanic sand or dust and form beds of ash. These latter are usually of a chocolate brown colour, and often contain white specks, which are probably decomposed fragments of felspar crystals. Near Bagno Secco, on the western side of the Island of Lipari, beds of rather fine-grained tuff or coarse ash are found, between the lamines of which beautifully preserved leaves and stems of plants occur, in much the same manner as at Somma. To the student of British geology the analogy presented by these modern leaf-bearing tuffs with those of Miocene age at Ballypalidy in Antrim, and at Ardtun in Mull, not only in the characters of their materials and in the state of preservation of the fossils, but in the particular groups of plants represented in them, such as planes, pop- lars, willows, flags, sedges, and horse-tails, is very striking. The best preserved examples of the beautiful fossil plants of Lipari were for- merly obtained at an almost inaccessible point of the cliff near Passo della Scarpa ; but the adventurous Liparote, who used to obtain them, having lost his life in one of his attempts to reach the spot, it is now rather difficult to obtain good specimens. Fragments of stems and leaves, however, abound at several points, and can be procured with- out difficulty by any moderately good climber. The tufts, etc., of the second period of volcanic activity in the Lipari Islands have suffered, equally with the lavas which accompany them, from being traversed by acid gases and vapours. The action of sulphurous acid on the lime of these volcanic rocks has given rise 14 J. W. Judd—On Volcanos. to the formation in them of beautiful veins of selenite, accompanied by Misy and other basic sulphates of iron, which are found inter- secting them in all directions. As an illustration of one among the many difficulties, the like of which we may not unnaturally anticipate experiencing, when seeking to define the exact character of some volcanic products of former geological periods, I may mention that, in some cases the bands of finer-grained ash in Lipari are converted into an intensely hard rock of jaspery aspect, and with a conchoidal fracture, to which—but for its mode of occurrence, its gradation into the ordinary tuffs around, and the plant-remains which it not unfre- quently contains—probably no geologist would dream of attributing its true mode of origin. Of the lavas and tufts of the second period of volcanic action in the Lipari Islands, a number of volcanic cones are built up, the craters of which, though usually clearly traceable, are often in the last stage of ruin and decay. Of these cones and craters we may instance the islands of Alicudi and Filicudi, each of which is a volcanic mountain rising directly out of the sea to the heights of 2,172 and 2,598 feet respectively, with vestiges of craters at their summits ; in Salina we have the two similarly ruined volcanos of Monte Porri (2,850 feet) and Monte Salvatori (3,125 feet), the highest summit in the Lipari Islands; in the island of Lipari the lavas and tuffs we are now describing compose the Monte Sant’ Angelo, the culminating point of the island, with its great axial crater and several smaller lateral ones on its eastern and western flanks; in Vulcano the period is represented by the series of ruined craters, forming all the southern parts of the island, and culminating in Monte Sarraceno (1,601 feet) : and, lastly, the central cone of Stromboli, having an elevation of 3,090 feet, with the doubtful crater at its apex, and the much clearer one on its southern flank, also belongs to the same period. In examining these old and much denuded craters, of which that on Monte Sant’ Angelo (represented in Fig. 3) affords an excellent Fic. 3.—Ruined Crater of Monte Sant’ Angelo in Lipari, as seen from the summit of the Monte della Guardia in the same island. example, the stratified arrangement of the tuffs, with converging dips in their interior parts and diverging ones exteriorly, a feature so characteristic of the structure of all volcanic cones (see Scrope’s ‘Volcanos,’ 2nd ed. p. 60), is often very admirably displayed. ‘The lava-streams can often be traced to their points of issue from the J. W. Judd—On Volcanos. 1 craters, but are sometimes cut up by denudation into isolated masses, capping hills composed of tuffs, like the plateaux of Ischia and the Auvergne. The lavas everywhere exhibit the characteristic slagg or scoriaceous upper and under surfaces, and are often seen to rest on beds which are burnt to a bright red colour. The masses composed of soft tuffs are often furrowed by deep ravines, which render some parts of the islands almost impassable, but which, when accessible, afford the most beautiful illustrations of the structure of the volcanos. But it is in the sea-cliffs of some of the islands, and more espe- cially in those of the southern and older part of Vulcano, that we find the most instructive examples of that interlacing of agglomerates, lava-streams and dykes, which constitutes the characteristic archi- tecture of volcanos. Not even the cliffs of Somma or the pre- cipices of the Val del Bove can compare, in this respect, with the faces presented to the sea on the eastern, southern, and western sides of Vulcano, where the mountain has been deeply eaten into by the encroaching waves (see Fig. 4). For anything approaching in beauty and completeness to the wonderful sections here exhibited, we must go to the ruined and dissected volcanos of the Hebrides. 4.—Section near Quaglia on the south-west coast of Vulcano. Fic. a. Rudely stratified tuffs. 6. Upper scoriaceous surface of lava stream. c. Compact central part ofsame. d. Scoriaceous under-surface of lava stream. e. Bed of burnt tuff of bright red colour. /. Tufts traversed by many dykes. That periods of great duration must have elapsed since the forma- tion of the series of volcanic products which we have been describ- ing, is indicated alike by the great amount of denudation which they have undergone and by the fact that they are covered by a younger series of deposits, some of which have themselves suffered not in- considerably from the same cause. That, on the other hand, they are of no great antiquity, from a geological point of view, is shown by the fact that the vegetable remains imbedded in them all belong to well-known species of the Mediterranean area. That movements of subsidence, similar in kind but less in degree than that which appears to have submerged the great central volcano of the group, must have taken place, in the case of the smaller and encircling cones, is shown by the relations which many of the lava- streams bear to them, as is particularly well seen in the coulées which form the peninsula of Monte Rosa, and which have evidently flowed from Monte Sant’? Angelo. But that the movements which have taken place in them have not been uniformly those of depres- sion, is also demonstrated by the existence around the shores of some of the islands of beautiful raised beaches, some of which are at least 100 feet above the sea-level. Of such raised beaches we have 16 Dr. Walter Flight—History of Meteorites. fine examples at the Rocca Piramida in Lipari and on the coast of Salina between La Malfa and La Capo (see Fig. 5). = — = [8 @0~- = —~— ee — eh — er ee —— 9 =9-9=S— 5 — 5-9 — (= = ee ee er eee ee ee == ——— ee a SS D5 229 5°55 — Ne oO = = = = —O =o py oes PSEC 2 OLD 22.00 "OS: o = : = of fe OS Oa USS A Ss A ESE e098. 28 O09 S08 a0 Fic. 5.—Interesting section at La Capo, the north-east point of Salino, exhibiting tuffs traversed by numerous dykes of lava and overlaid by stratified materials derived from them. (Raised-beach.) We must postpone to a future communication the description of the remarkable linear arrangement of the volcanic vents of the Lipari Islands, when we hope also to give an account of some of the character- istics and products of the last series of igneous outbursts in the district. (To be continued in our next Number) IL—A Cuarrer in THE History or MureroritEs. By Watter Fuicut, D.Sc., Of the Department of Mineralogy, British Museum ; Assistant Examiner in Chemistry, University of London. INTRODUCTION. Y the publication of Die Chemische Natur der Meteoriten, in B 1870, Professor Rammelsberg accomplished the task which he had set himself, that of presenting to students of mineralogy a care- ful digest of the scattered contributions of the time to the literature -of meteorites. Since that date no similar work of reference has been issued. Buchner’s papers, intituled Die Meteoriten in Sammlungen, the first of which was issued at an earlier date than Rammelsberg’s memoir, do not apparently continue to be published, the last one having appeared in Poggendorff’s Annalen in 1869. It is from this period that 1 propose to take up the thread, and to give in the following pages a digest of all that has been published on the subject of meteorites since the beginning of that year. In this time many important contributions to this branch of minera- logical science have been made; highly interesting meteoric falls have taken place, among them it will here suffice to mention that of Hessle, in Sweden; remarkable cosmical masses have been discovered, of which none are more curious than the colossal meteoric irons of Ovifak, in Greenland; and the presence of new meteoric minerals determined, such as the calcium sulphide of the Busti aerolite and the rhothbic form of silicic acid in the Breitenbach Dr. Waiter Flight—History of Meteorites. i siderolite. The bearing of the study of meteorites on our know- ledge of cosmical physics and geology will be readily acknowleged. It is proposed to deal with the subject under the following four divisions :— I. To present seriatim a description of all meteoric bodies that have been known to fall, or that may have been found, since the above date (1st January, 1869), including an account of all import- ant phenomena attending their descent, and a description of their physical and chemical characters, or those of their ingredient minerals as far as they have yet been determined. In the examina- tion of the analyses, it will be shown that the hypothetical silicate shepardite, which at the present time is supposed by many miner- alogists and geologists! to form a constituent of meteorites (although it has never been isolated), not only need not be assumed to be present, but that the analytical results of these observers indicate the presence in the aerolite of such silicates only as have on some occasion or other been observed to occur as distinct species in a meteorite. II. To produce a similar digest of work done from 1869—1874 on meteorites which had fallen, or had been found, at an earlier date, giving such results as correct earlier analyses. III. To prepare an exhaustive notice of papers published from 1869—1874 on meteorites : (1). In their relations to astronomical questions; their probable orbits; the phenomena attending their fall; their distribution on the earth’s surface ; spectroscopic examination, etc. (2). In respect to better methods of analysis; new catalogues of collections ; and the bibliography of this branch of miner- alogy. ‘IV. To examine cases of doubtful falls, pseudo-aerolites, etc., which have been placed on record during the above interval. Part I. 1869, January Ist, 12h. 20m. p.m.—Hessle, near Upsala.” This is the first meteoric fall recorded to have taken place in Sweden. The sky was cloudy, and, though apparently unobserved at Hessle, a luminous meteor was noticed by observers at a distance. The noise accompanying the fall resembled heavy peals of thunder, followed by a rattling noise as of waggons at a gallop, and ending first with a note like an organ tone, and then a hissing sound. The stones were strewn over a line of country lying 30° E. of 8. towards 30° W. of N. Some of them fell within a few yards of a number of 1 Tn his address ‘‘ Ueber die Entwickelung der Geologie in den letzten 50 Jahren,” delivered before the German Naturalists’ Association at Leipzig in 1872, Von Dechen alluded to shepardite (anderthalbfach kieselsaure Magnesia) as a characteristic meteoric mineral. 2 OQ. Fahnehjelm. Meteorfallet i Fittja socken af Upsala lan d. 1 Januari, 1869, Oefversigt Vet. Akad. Ford. 1869, No. 1, 59.—A. E. Nordenskjéld. Kongl. Svenska. Vetensk. Akad. Handi. vii. No. 9; Pogg. Ann. cxxi., 205.—G. Lindstrém. Kemisk Undersokning af Meteorstenarne fran Hessle. Kongl. Svenska WVetensk. Akad. Ford., 1869, No. 8.—K. A. Fredholm. Om Meteorstensfallet vid Hessle. Leipzig: Fritsch.—G. -A. Daubrée. Compt. rend., Ixviii., 363. DECADE 11.—VOL. II,—NO.I, . 2 18 Dr. Walter Flight—History of Meteorites. - peasants who were coming out of church; one struck the ice close to a man who was fishing on the Malar Larsta-Viken, and after digging a hole three or four inches deep, rebounded; when picked up, it was still warm. The stones vary greatly in weight, from 2lbs. to 0-17 gramme (about 24 evains). The smallest have the same structure and thick- ness of crust as the largest, and are in fact little complete meteorites. Such diminutive stones have not hitherto been noticed, and should be sought for at future aerolitic falls. The exterior of the stones is black; the interior bright grey, and sufficiently porous to cling to the tongue. Though the structure of these meteorites is so loose that they break in pieces when thrown with the hand against the floor or frozen ground, it is a remarkable fact that nearly all the specimens which have been collected fell intact, and some of the heavier stones which struck the ice of the Larsta-Viken failed to penetrate it, although the thickness was only a few inches on New Year’s Day. This explains in some degree the statements of eye-witnesses as to their remarkably small downward velocity. In appearance they resemble very closely the meteorites of Aussun -and Clarac, Haute Garonne (9th December, 1858). They have been examined by Nordenskjéld, who so arranges the results of his analyses that he finds them to be composed of: 20 per cent. nickel- iron (chamoisite, Fe,Ni), with some schreibersite and rather less than one per cent. of chromite ; a variable amount of troilite (iron mono- sulphide); a trace of carbon, probably in the form of a hydrocarbon ; 10 per cent. of labradorite; 87 per cent. of olivine; and 28 per cent. of ‘shepardite.’ Two great difficulties, however, are presented by this explanation of the constitution of the Hessle meteorites. It is not only assumed that a basic silicate, like olivine, and a sesquisilicate, or acid silicate, like ‘shepardite,’ exist in intimate association in the same rock-mass, but it necessitates the retention as a mineral species of this very ‘shepardite’ which the researches of Dr. L. Smith on the Bishopville stone have shown to be no other than a pure magnesian enstatite (MgO,S8i0,). In the following table are given: under I. the oxygen ratios of the mean of the total constituents from three analyses, after the nickel- iron had been removed by mercury chloride in one case, and by the magnet in another; under II. the oxygen ratios of acid and bases of silicate broken up by acid; and under III. the difference between I. and II., or the oxygen ratios of acid and bases of silicate un- affected by acid. I. Total. II. Soluble. III. Insoluble. Siliciec acid ... 26:45 ... 10°78 SHG 15°67 Tron protoxide 2:971 ... 1°858 1:113 Magnesia ... 11°82 ... 7°559 4:261 Alumina ceo LEBIL a5 OOS} 1-401 Lime soo WEES cog OPI) VED ong OB) ee Soda ra OLGOS) vee Oral 0-048 Dr. Walter Flight—History of Meteorites. ILS) In the soluble part the oxygen ratios do not widely differ from those of an olivine, while the atomic ratio of iron oxide to magnesia, nearly 1 to 4, is that observed in many meteoric olivines; among others those of the aerolites of Chantonnay, Oesel, and Richmond. As in Nordenskjéld’s analysis the soluble portion was collected atter the powdered mineral had been digested for a long time with warm concentrated acid, it is certain that some portion of any bronzite or enstatite that might be present would undergo decomposition, and this would explain the slight excess over 1 to 1 in the oxygen ratios of acid and total bases in the insoluble part. This insoluble portion, it will be seen, appears to be chiefly bronzite, and here again the ratio of the two metallic oxides, also about 1 to 4, is that of the bronzite of several meteorites, including among them the three mentioned above; and the Hessle meteorite is a fourth example, in both the olivine and bronzite of which the atomic ratio of iron oxide to magnesia is the same (1:4). The alumina has been regarded as a constituent of the bronzite, very few specimens of that mineral, whether terrestrial or meteoric, containing none of this oxide; it could not be present as anorthite, as the chief amount is in the insoluble portion; nor could it be in the form of any other felspar, as the requisite alkali is not present. The most remarkable feature of the Hessle shower is the associa- tion with the stones already described of other cosmical matter, chiefly composed of carbon. It was remarked by the peasants that some of the stones which fell on the ice near Arné soon crumbled to a blackish-brown powder, which formed with the snow-water a mixture resembling coffee-grounds. Similar powder was found on the ice at Hafslaviken in masses as large as the hand, which floated like foam on water, and could not be held between the fingers. A small amount, secured for examination, was observed under the microscope to be composed of small spherical granules. It contained metallic particles extractible with the magnet, and, when ignited, burnt away, leaving a reddish-brown ash; heated in a tube, it gave a small amount of a brown liquid distillate. A specimen dried at 110° had the following composition :— Carbon Hydrogen ... 200 Oxygen (calculated) Silicie acid 555 Iron protoxide Magnesia ... Lime S00 200 500 Soda, with trace of lithia ... Equivalent Ratios. 2 nr e ° e 38 1:96 ee ch © chim INI 100-0 The combustible constituent accompanying the stony matter in the above mixture appears to have the formula nC,H,O, The Hessle stones form a new member of the small class of carbo- naceous meteorites, that is to say, such as contain carbon in the amorphous form, or combined with hydrogen and oxygen, or in both these conditions; it includes at present those which fell at Kaba, Cold Bokkeveldt, Alais, Orgueil, Goalpara, and others. 20 Dr. Walter Flight—History of Meteorites. It was noticed that the stones found in the same district with the carbonaceous mass were, as a rule, quite round, and covered on all sides with a black, dull, and often sponge-like, crust. The iron particles on the surface of the smaller stones were usually quite bright and unoxidized, as would be the case if the stone had been heated in a reducing atmosphere. Nordenskjold believes that the carbon compound frequently, perhaps always, occurs in association with meteorites, and he attributes its preservation at Hessle to the fact of the stones having fallen on snow-covered ground.—The paper is illustrated by a map of the district, indicating the exact points where the larger masses descended. 1869, May 5th, 6.32 p.m.—Krahenberg, near Zweibriicken, Rhenish Bavaria.! A single stone was seen to fall, the sky being clear and bright. The noise of the explosion is described as having been louder than that of a cannon; this was followed by one resembling a roll of musketry, terminating with a sound as of the rushing of steam from a loco- motive ; the tone of the last sound increased in pitch, and abruptly ended with another loud noise. Although no luminous phenomena were observed at Krahenberg, a meteor was seen at Bingen, Speyer, Neuweiler, in Alsace, and in other parts, which observers agree in describing as emitting an intensely white light; one witness, who saw it in the zenith, states that the light was bluish. The inclination of the path of the meteor to the horizon is computed to have been 32°. From observations, made independently by two witnesses, it appears that this meteor came from the point in the heavens, 82° North Polar Distance and 190° Right Ascension. In the Atlas of Meteors (British Association) there is given a radiant point (85° N.P.D. and 189° R.A.) for the epoch of 2nd April to 4th May, and which is indicated as one of those that are ‘ well-defined.” It appears, then, to be highly probable that the Krahenberg meteorite, while traversing its cosmical path, belonged to the meteor shower, the radiant point of which lies near 6 Virginis. Vom Rath states that the stone fell from a small cloud. A little girl was within a few paces of the spot where it struck the earth, on the slope of a hill facing the S.E.; it entered the ground to a depth of from three to four feet, making a perfectly vertical hole. It was soon dug out, and when brought to the village was warm, but not hot. The stone is of the form of a flattened spheroid, and weighed, when entire, about 53lbs. The crust is about 0°5 mm. thick, and though in most parts black, some portions possess the peculiarly yeddish-brown colour noticed on the Pultusk stones. The specific gravity of the stone, free from crust, is 3°497; that of the crust is 1 0. Buchner. Pogg. Ann., cxxxvii, 176.—G. vom Rath. Pogg. Ann., cxxxvii., 328.—C. EH. Weiss. ogg. Ann., exxxvil., 617.—G. Neumayer. Sttzber. Wien. Akad., \x., 229.—P. Reinsch. Lithographic ‘ Suite Mikroscopischer Praeparate”’ of this Meteorite, issued March, 1872; and Zugeblatt 45, Versammlung der Natur- Sorscher in Leipzig, 1872, 132. Dr. Waiter Flight—History of Meteorites. 21 3-449; as in the Pultusk meteorite, the crust is lighter than the body of the stone. A remarkable feature of the surface are the numerous furrow-like depressions, some 8 mm. deep, which often anastomose and radiate from the more even crown of the stone towards its periphery; they are confined to the more rounded side of the stone. A newly broken surface is light grey, and ex- hibits a net-work of fine black lines and veins of nickeliferous iron; in one place a little gangue of metal measured 38 inches in length and 0-3 to 0-5 mm. wide. This meteorite bears a great resemblance, both as regards the crust and internal structure, to those above alluded to, which fell at Pultusk, in Poland, on 30th January, 1868. Spherules are abundant; and other minerals readily distinguishable are: olivine, magnetic pyrites, and chromite ; the whole being inclosed in a “sphaerolithic ” ground-mass of white and grey grains. 3 Nickel-iron, containing 15°3 per cent. of nickel, constitutes 3-5 per cent. of the stone, a less quantity than is found in the Pultusk meteorites ; magnetic pyrites amounting to 5-d2 per cent., a larger proportion than is met with in the Pultusk stones, occurs in grains, some 1 to 2mm. wide. The dark-coloured spherules, the presence of which is a characteristic of chondritic meteorites, are more distinct and numerous than those of the Pultusk stone: some are 2 mm. wide, and are easily removed from the ground-mass. Yellowish- white grains, some 1 mm. wide, are abundant, and here and there are found grains of chromite, bearing octahedral faces. Viewed in the microscope, the mass of the stone is made up of numberless small white crystalline granules, which give colour in polarized light ; they are stated by Vom Rath to be unacted upon by acid, and to consist essentially of a magnesium silicate, richer in silica than olivine. Among other eurious constituents detected by the microscope are: a very small purple-red crystal bearing faces ; a number of bright-yellow granules in distinct crystals ; some light- yellow long prism-like forms; and a few large granules 0-5 mm. across, of a translucent red mineral, exhibiting conchoidal fracture. So small a portion of the stone could be devoted to chemical exami- nation that none of these substances, nor even the large spherules, could be separately analyzed. The analysis of the stone furnished, after the nickel-iron and magnetic pyrites have been deducted, the per-centage numbers of acid and bases, the oxygen ratios of which are 1: 1-448, the ratio in the Pultusk stone being 1:1:507. The analogy in composition, in respect of each constituent, of two bodies from so widely separated regions of planetary space is very striking. Vom Rath expresses his belief that “the siliceous portion of this meteorite, and indeed of the Pultusk stone, is mainly composed of olivine and another, a magnesium, silicate richer in silicic acid; but whether it be enstatite or shepardite (2Mg¢O0,8Si0,), or whether both silicates accompany the olivine, cannot, unfortunately, be determined.” Apart, however, from the doubts that are now entertained respect- ing the existence of the magnesium sesquisilicate of Rose as a mineral species, the analytical determinations of Vom Rath will 22 Dr. Walter Flight—History of Meteorites. not be found, on examination, to support the theory in question. In addition to the composition of the entire stone, which is to be found below (1.), he gives in his paper the amounts of each of the bases dissolved in acid during a sulphur determination (see II.). I. Total Silicates. II, Bases dissolved III. Bases undissolved Oxygen. Oxygen. Silicic acid ... 46°37 WWiteriesi ay iiiecs @2(alo)) eal: ( are OS .. 15°43 6:17 Lime Hees Dele mete 0:56 0°16) 9:55... 1:59 0°45 } 6°92 Iron protoxide... 22°56 ... 21:2 4:71 a. else O45 INUDTOB cog Soon ORG a Opt sant 0 07598 Loss (Soda?)... 1°12 100°00 © Assuming the bases dissolved to be those of an olivine, they would require 17- 90 per cent. of silicic acid to form 51°36 per cent. of an olivine of the form FeO, MgO, SiO, (like that occurring in the me- teorites of Chateau-Renard and Kakova), while. the undissolved bases with 25-95 per cent. of silicic acid form 45°45 per cent. of a nearly pure magnesian enstatite. There now remain only 2°52 per cent. of silica, which, with the alumina, and what may possibly be potash, give oxygen ratios, pointing, with more accuracy than might be expected in so small a residue, to about 4 per cent. of what may be a felspar. This method of regarding the con- stitution of the meteorites of Krihenberg and Pultusk has the advantage of assuming the existence in these stones of such meteoric minerals only as have been isolated and clearly identified.— In an elaborate paper on the lithology of this meteorite, Weiss states that he detected the presence of three silicates, and by a careful study of a fresh surface of the stone, he finds that the grey silicate, which is probably enstatite, occurs in three distinct forms. This is a point of considerable interest, not only as tending to confirm the above calculations, but from the fact that three varieties of a nearly pure magnesian enstatite likewise occur in the Busti aerolite. Reinsch has prepared eighteen microscopic slides of this meteorite, and made very effective pen-and-ink sketches of the more important of them. One shows a remarkable eroded spherule of iron; the evenly serrated surface is inclosed in a metallic shell, or rather net, so regular are the intervals at which this covering is broken through. Another exhibits spherules traversed by little dykes or veins of a mineral, which in one case is of a purple colour. Others show a beautiful blue mineral, which he suggests may be haiiyne. He directs attention to the presence of magnetic pyrites and nickel-iron in the crust of the meteorite, and contends that, as these minerals would undergo change if exposed in air to a temperature at which the silicates forming the crust fuse, the meteorite must have been covered with a crust before it entered our atmosphere, and he ascribes the fusion to electrical agency, as seen in the perforated rocks (fulgurites ?) of the Lesser Ararat, described by Abich. Dr. Walter Flight—History of Meteorites. 23 Bae, May 20th, 11.20 p.m.—Moriches, Long Island, Suffolk Co., - New York.’ hen unusually brilliant meteor was seen at New Haven, New York, Philadelphia, Hartford, and many other places. It appears to have moved, nearly horizontally, at an elevation of fifty miles, along a visible path of about 200 miles, and to have exploded over the Atlantic somewhat N. and E. of Boston. The time of flight is estimated at five seconds, which indicates a velocity of forty miles per second. Three minutes after the passage of the meteor, ‘a terrific sound” was heard at Moriches, which shook the house of the observer to the very foundation. The angular diameter of the meteoric body is estimated to have been 30’, the distance from Moriches at the time of the explosion, thirty-nine or forty miles, the altitude twenty-eight miles, and the actual diameter 1848 feet. It recalls to mind the celebrated meteor of 1783, August 18th, 9°30 p.m., which traversed Europe from N.W. to §.H.? 1869, May 22nd, 10.5 p.m. Paris time (9.45 p.m. Vannes time).— Kernouve, 2 kilometres from Cléguérec, Arrondissement de Napoléonville, Morbihan, France.* A meteor was seen moving in the direction from §. to N. It burst very soon, throwing off a number of greenish-white sparks, which almost immediately lost their brilliancy, and in two and a half or three minutes an explosion was heard. At Vannes, the very intense bluish-white light, which lasted for some seconds, resembled that of burning magnesium. ‘The stone penetrated the soil of a meadow to the depth of one metre, and was quite covered by the loose earth thrown up by the shock; when exhumed it was broken up by the peasants. A young girl, distant only a few metres, was the sole witness of the fall; the leaves and ends of the branches of some trees close at hand bore marks of having been scorched. The stone, when perfect, probably weighed about 80 kilogrammes, and was of a conical form; the crust is of two kinds: an outer black enamel rugose and blistered, and an inner simple coat of glaze; in some places grains of iron projected through both crusts. The interior is a dark grey colour, and is very compact and granular. The iron is disseminated in very brilliant grains; here in veins some centi- metres long, there in masses several millimetres in diameter. The “Inagnetic pyrites (troilite?) occurs but rarely in veins, sometimes in masses 8 centim. long, and 2 millim. broad. Occasionally grains of ‘ an enstatite or felspar are seen. In texture this stone bears a great 1K Loomis. Amer. Jour. Sce., 1869, xlviii. 145. 2 May 20th—22nd, appears at the present time to be a period during which meteoric falls may be looked for. During the last six years the following ‘five falls have occurred : 1868, May 22nd, Slavetic, Croatia. 1869, May 20th, Moriches, New York. 1869, May 22nd, Cléguérec, France. 1871, May 21st, Searsmont, Maine. 1874, May 20th, Virba, Turkey. ~ 3 De Limur. Compt. rend., lxvili, 1888.—F. Pisani. Compt. rend., |xviii. 1489. 24 Dr. Walter Flight—History of Meteorites. resemblance to the aerolites of Pultusk (30th January, 1868). The density of the meteorite is 3°747; it gelatinizes with acid, giving off hydrogen-sulphide. Pisani states that the iron sulphide is not attracted by the magnet; he has, however, given it in the form of magnetic pyrites in the following total composition of the stone : INiekelairontaesepmeccin eesti ccumicriee OnO0, Magnetic pyrites (P) ... ... .. 5°46 Dissolved silicate ... ... ... ... 94°60 Undissolved silicate ... ... .. 40°22 100°77 The nickel-iron is composed of: Tron = 92°44 Nickel = 7:56 = 100-00 and the silicates of: Si0, Al,0, FeO MgO CaO Na,0. A. Soluble ... 29°04 2:98 22°31 42:95 1:36 1°36 = 100-00 B. Insoluble... 56°94 5:37 9:89 21:98 3:53 2°34 = 100-00 1869, September 19th, 9 p.m —Tjabé, near Pandangan, Bodgo-Négoro, in Residence Rembang, Java.’ A meteor, the brilliancy of which is stated to have surpassed that of the moon, was seen about nine in the evening to move in a north- easterly direction over the village of Tjabé. It was observed at Pandangan, the chief place of the district, as well as at Bodgo-Négoro, chief town of the division, lying east of Pandangan. At the same time a meteorite fell at Tjabé, at a distance of about twenty metres from the house of a native named Sokromo. The sound following the appearance of the meteor is described as an explosion, as loud as that of a cannon, followed by a noise resembling that caused by a carriage crossing a bridge; this lasted some time. The villagers sought in vain for the spot where the meteorite fell ; at six o’clock next morning, however, it was found at the place already mentioned, at a depth of two feet in soil which had been hardened with a long drought. According to the report drawn up by the President of Rembang, it was remarked by the villagers that the aerolite, when found, was still so hot that it could not be touched with the hand. This statement, however, must be received with caution. This stone, the only one found, weighed about 20 kilogrammes. It is covered with a dull greyish black crust, 0°56 mm. in thickness ; the fresh fracture is dark grey, and exhibits a number of brilliant points: here and there brilliant plates 1 mm. square are met with, as well as a small number of very dark, almost black, grains of spherical form, with a diameter of about 2mm. The mass of the stone is coarsely granular, and is so very hard that portions are only detached with a hammer with great difficulty. The specific gravity of the metallic portion is 6°8; the magnet removed 14 per cent. constituents, which consist of two alloys of nickel-iron, containing respectively 6:2 and 12:5 per cent. of nickel ; in one portion of the stone was found 6°17 per cent. of troilite. ‘The density of the stone is 3695. 1. H. von Baumhauer. Archives Neéerlandaises, vi. No. 4 (1871).—G. A. Daubrée. Compt. rend., 1871, 16th December. Dr. Walter Flight—History of Meteorites. 25 The analyses of the rocky portion yielded the following results :-— Si0,. Al,0;. FeO. MnO. MgO. CaO. Na,0. K,0. Chromite. A. Soluble ... 84°72 0°70 26:14 0°65 35°70 1:61 0°48 Trace — =100°00 B. Insoluble... 60°83 4°74 12:92 0:60 14:14 8:30 1°53 0°82 1:12=100-00 The soluble siliceous portion, forming 45:94 per cent. of the non- metallic part of the aerolite, consists of an olivine in which the oxygen ratios of FeO and MgO are as 2:5. As in most analyses of meteorites, where the separation of the silicate of the form 2RO,SiO, is attempted to be effected by means of acid, the silica in A, the soluble portion, is insufficient to form an olivine. The silica of B, the insoluble portion, on the other hand, is not only present in ample quantity, to make good what is wanting in A, and to supply the silicates of the form RO,SiO,, but is in sufficient excess to lead Baumhauer to assume the presence of a bisilicate in the insoluble portion. If, however, the requisite amounts of silica be apportioned to the protoxides of iron, manganese, magnesium, and calcium of A and B, to form the respective silicates, there remain in the insoluble portion the following constituents, the oxygen ratios of which, as will be seen below, do not differ widely from those of an albite or orthoclase : Si0,=5°326; Al,0=1:13; K,0=0-:16; Na =0:39. Baumhauer traces a resemblance, in point of composition, between the aerolites of Tjabé and Mezé-Madaraz (4th September, 1852), by - comparing his results with those published by Atkinson,’ who analysed the latter stone in Wohler’s laboratory. About the time of the publication of this paper of Baumhauer’s (1871), Rammelsberg” announced the result (see infra) of his examination of the Mezo- ’ Madaraz stone, which differs very considerably from those arrived at in the earlier analysis; where, in the insoluble portion of the Mezo6-Madaraz stone, Atkinson found no iron protoxide, Rammelsberg finds 13-27 per cent. It will suffice in this place to mention that the later analysis of the Transylvanian aerolite does not indicate the presence of an excess of silica, and yields numbers which point to the presence of an olivine, like that found in the meteorites of Hainholz (1856) and Shergotty (25th August, 1865), and of bronzite oS that occurring in the aerolite of Chantonnay (5th August, 1812). 1869, October 6th, 11.40-45 a.m.—Stewart County, Georgia.® When this stone fell, the sky was somewhat hazy, but there was no cloud. An observer at Bladen’s Creek heard a roaring rushing sound in a north-westerly direction ; in a moment it appeared to be directly westward; then a loud explosion, followed by six other reports, occurred. After these explosions a peculiar whizzing sound was heard, produced apparently by some large irregular body moving rapidly away, while a smaller one passed to the south-west with such a noise as is caused by a flying fragment of a shell. 1K. Atkinson. Jour. Prakt. Chem., 1856, 357. Phil. Mag. xi. 141. 2 ©. Rammelsberg. Zezt. Deutsch. Geol. Geselisch., 1871, 734. 3 J. E. Willet and J. L. Smith. Amer. Jour. Se. 1. 335, and 339. 26 Dr. Walter Flight—History of Meteorites. This piece, it was found, descended about two miles and a half from the point where the explosion occurred; it weighs about 124 ounces. Two men, who were looking in the direction of the explosions at the time they took place, state that they saw a quantity of vapour much like a volume of steam escaping from an engine-pipe, which was violently agitated, and increased in bulk after each report, but dis- appeared soon after the last of them. Some labourers close at hand saw directly after the explosions something like a thin cloud cast its shadow over the field in which they were. The stone, already alluded to, and which was seen to strike the ground by two negroes who happened to be at work about twenty paces distant, appears to have come from the north-west, at an angle of about 30° with the horizon ; it passed to a depth of ten inches into the soil. It has an irregular, seven-sided form, the longest side being about 22 inches long, and is covered with a black crust. The specific gravity is 3:65. The explosion appears to have been heard over a region about 30 miles N.E. and S.W. and 50 or 60 miles N.W. and S.E. The fractured surface has a greyish aspect, and exhibits numerous greenish spherules, with white granular interstitial matter, and occa- sional particles of nickel-iron, troilite, or chromite. The nodules are sometimes more than 3 mm. in diameter, with an imperfect fibrous — crystalline structure, the radiation usually commencing from one side of the spherule ; they are more or less opaque, and of a dull, bottle- green colour, with a hardness of about 6. Analysis of this selected mineral gave the following results :— Oxygen Ratios. Silicic acid ... 48°62 ... 29-9 Alumina... 8:05 ... 3-79 \ ENE Tron protoxide 11:21 ... 2°51 | 14:31 Magnesia ... 30°18 ... 11°80 98-06 The formula of this mineral, with a portion of the silica replaced by alumina, a not unfrequent occurrence in minerals like hornblende, hypersthene, etc., is therefore RO,SiO, and it is probably a bronzite. _ The nickel-iron has the composition : Iron = 86:92; Nickel = 12:01; Cobalt = 0:75 = 100 and that of the rocky portion is as follows: Si0,. Al,0; FeO. MgO. CaO, Na,0. A. Soluble 41:08 032 1845 41:06 — = =100°91 B. Insoluble 56°03 5°89 15:21 21:01 0°10 2:97 =101°21 The author deduces the following for the composition of the . stone: MNickel=inoneeecnercee: owt es 70 Midonetic pynibesnaen tpona tte cuglerepMamech duet katie Okc ses) see ORL Bronzite, olivine, albite, or oligoclase, and chromite... ... 86-9 100-0 1809, November 6th, 7 p.m.—Fawley, near Southampton.’ The correspondent observed two meteors within a few minutes of seven o’clock on the evening of that day, which was a Saturday, and 1A.T. Smith. The Standard, November, 1869. Dr. Walter Fluight—LHistory of Meteorites. 27 on the following Wednesday discovered a ‘ meteorite’ which weighed more than 1 lb. avoirdupois. “It had not penetrated the ground more than half an inch.” From the description of what he found, it appears that he picked up a nodule of marcasite, which had probably been left exposed on the surface after heavy rain had washed away the surrounding soil. 1869, December 25th.—Murzuk, Fezzan [Lat. 26° N.; Long. 12 E. | of Paris ].' The letter of M. Coumbray, communicated to the Geological Society by Mr. R. H. Scott, announced the fall of an aerolite, or bolide, at Murzuk, in the presence of a group of Arabs. The bolide on falling is described as having “exploded with a sound resembling pistol shots and a strong odour.” The intelligence was communicated to the Vienna Academy by Haidinger, and to the Berlin Academy by Dove; and Mr. Greg, in the British Association Report, states that it fell on the 26th December, and that it weighed 6000 lbs. It appears highly probable, however, from a statement laid before the Berlin Academy by G. Rose* at a more recent date, that no meteoric fall took place. According to letters received from the Austrian Consul at Tripoli and Hag Ibraim Ben Alua, Shiek of Murzuk, a corporal, who was on guard at the gate of the town on the night of the 25th, heard a series of explosions, like the discharge of nine muskets. Hearing the alarm, the officer collected five men, and, sallying forth, they met a man, who stated that the noise was not the report of guns, but the explosion of a meteor, which burst in the direction of a little village called Namus. The writers of the letters were of opinion that no meteorite had been found. Meteoric Iron. Found in 1869 or 1870.—Shingle Springs, Eldorado County, California.? This mass, said to be the first discovered in California, was rescued in 1871 from the forge of a smith, who found it ina field near Shingle Springs. It weighed about 85 Ibs., and its largest dimensions were 24 and 29c.m. It is very homogeneous, only two small masses of pyrites (troilite?) being visible on one of the sides. The crust to a depth of from 4 to 5 cm. is remarkably hard. The density 7-875 (that of some pieces removed by the planing tool being 8-024) is above the average density of meteoric iron, and this is most probably due to the presence of an unusually large proportion, more than 17 per cent., of nickel, as the subjoined analysis indicates. MONI cee Facet wel SLA Carbon co boo) OAD A/T PeNickeluipyestaiad cheeapdiehis SiCiUM se 524 wes y aes OL082 Cobalt tices. u 05604 Phosphorus .- 0°308 Aluminium .... ... 0088 Sulphur soo 00 DIL Chromium ... .., 0020 Potassium coo con OULAG Magnesium ... ... 0-010 Calcimm=- % is.) “sean | O:468 99:987 1M. Coumbray, Jour. Geol. Soc., xxvi. 415. Grou. Mac., VII. 236.—R. P. Greg. Rep. Brit. Assoc. 1871.—Bullet. Meteorologico, ix. 4.—G. Rose. Monatsber. Berlin Ak., November, 1870.—G. Tschermak. Sitz. Wien. Ak. June, 1870. . 2 G. Rose. Monutsber. Berlin Ak., 1871, 804. 3B. Silliman. Amer. Jour, Sc, [3] vi. 18, 28 Dr. Walter Flight—History of Meteorites. Another remarkable feature of this iron is the obscure characters of its crystalline structure : when etched, the acid discloses a confused granular surface, exhibiting under a lens a reticulated structure with numerous brilliant points and V-shaped lines. The Eldorado iron resembles that of the Cape of Good Hope, analyzed by Uricoechea, in the absence of Widmannstiittian figures and in the presence of a large per-centage of nickel. The meteoric irons which contain most nickel (and cobalt) are : Nickel. Cobalt. Total. Grenville, Tenn. ... ... 17-10 2°04 19°14 per cent. Tazewell Co., Tenn. ... 1462—15:02 0:43—0:50 — 90 Cape of Good Hope ... 15:09 2°56 17°65, Few analyses have detected more than 10 per cent. of nickel in an iron, and the average amount of this metal in eighty analyses com- pared by Silliman is not above 7:25 per cent. This is not the earliest notice of the Eldorado iron. In June, 1872, Shepard! published a short note on it in the same journal. He determined the specific gravity to be 7-80, and found only 8:88 per cent. of nickel, as well as 3:5 per cent. “insoluble, consisting of a mixture of Fe,O, and FeO, with minute silvery particles of supposed phosphor-metals.” The examination was evidently an imperfect one. Meteoric Irons found in 1869.—Staunton, Augusta Co., Virginia.’ This is the fourth recorded instance of meteorites having been found in the State of Virginia. Three masses of meteoric iron have recently been met with: No. 1, weighing 56 lbs., was turned up by a plough, five miles somewhat H. of N. from Staunton, in lat. 38° 14’ N., and long. 79° 1’ W.; No. 2 weighs 36 lbs., and was met with one mile 8.H. of No. 1; and No. 8, which weighs 34 Ibs., was found half a mile still further 8.H. They were covered with a dark brown crust 4 to din. thick; on exposure to moist air, a liquid, containing iron, nickel, and chlorine, exuded from many parts of the surface. This iron, which exhibits feeble magnetic polarity, and has a specific gravity of 7-83 to 7°89, is compact and highly crystalline, and contains occasional grains of troilite. Traces of Widmannstiittian figures can be detected even without acid; but this reagent developes them in great beauty, and with considerable resemblance to those of the Lenarto and certain Mexican specimens. The irons were cut so as to give different projections of the same crystalline structures; in No. 1 the bands of iron and schreibersite intersect at 120° and 60°, in No. 2 they ap- proach 90°, and in No. 38 are at about 60°. The author states that by prolonged action of acid, white, pliant, and strongly magnetic laminz of schreibersite are brought to view. He does not appear to have analyzed them, and to judge from obser- vations made on other irons, I consider it highly probable that the 1 ©. U. Shepard. Amer. Jour. Sc., [3] iii. 438. 2 J. W. Mallet. -Amer. Jour. Sc., [3] ii. 10 Brit. Assoc. Report (Brighton), 1872, 77; Proc. Royal, Soc. xx. 865; Pogg. Ann. cxlvii. 134. Dr. Waiter Flight—History of Meteorites. 29 plates are not schreibersite, which is very brittle, but an alloy free from phosphorus, and containing about one-third its weight of nickel. The three masses gave on analysis the following results: No. 1. No. 2. No. 3. Tron, |b iccln eey eee esa OO OG 88°365 89-007 INGO ANS | dao icod vdeo coo | ORIG) 10°242 9:964 Goines cog Gan 660 ca cc PE 0:428 0°387 CHO NEP ecg aco: cca cao! don OOOH 0-004 0:003 Tin Ree eee racer auntie orcs Ta OLO.O 2; 6-002 0:003 Manganese ... ... ... ... trace. — trace. Waxbonmiers q ies peas yisse) pisses Ole 0°185 0:122 THOOSVNOAS B55 con coo od | Weebl 0-362 0°375 Sulphur Neth ese see Mee) OS0ND 0:008 0:026 Dili capaeen i accy saci cecohateaci sie 0007 0-061 0:056 Chlorine Aooy apd pect eao | RUE) 0:002 0-004 99°872 99-659 99:947 The chlorine is not of meteoric origin; a solid piece of No. 1, weighing 50 grammes, and quite free from flaws or fissures, con- tained no chlorine whatever. Some portion of the siliceous residue from the action of the acid probably consists of silicide of iron; when magnified 500 diameters, and examined by polarized light, it is found to consist of an amorphous powder, and rounded transparent grains of 0:0025 to 0-0100 mm. diameter, and with well-marked doubly refracting characters. The three masses are, beyond ques- tion, portions of a single fall. Pieces of this iron have been forged. One, which was hammered cold, could be beaten into any desired shape; a second, which had been exposed to a red heat in vacuo, could only be forged in the cold with much difficulty; while a third piece that had been subjected to a white heat could not be forged at all, and crumbled under the hammer when reheated. Mallet is of opinion that the brittleness arose from the melting out of the phosphide, “leaving the iron porous.” As the amount of phosphorus present was but small, and did not exceed one per cent., it may have rendered some portion of the iron, ‘cold short.” The gases occluded by this iron were collected by Mallet and . analyzed. The material consisted of some turnings and a solid piece of the metal. The cutting apparatus employed to reduce them to the requisite size was heated to a red heat, and quenched in water, to remove all traces of oily matter. Graham extracted from the Lenarto iron 2°85 times its volume of gas; Mallet obtained 3:17 volumes from his specimen. The latter was heated during four- teen and a half hours at a red heat, and then to an incipient white heat. During the first two and a half hours 52 per cent. (I.) of the entire gas was removed ; in the next 2 hours 20 minutes, 24 per cent. ; (II.), and in the remaining nine and a half hours, 24 per cent. (IIL). Below are given for comparison the composition of these three 1 The residue left on treating the Tuczon iron with acid appears to have borne a great resemblance to this substance. Compare with the description given in Buchner’s Meteoriten, p. 183. SOR PEP ror. A. Nicholson— On some New Devonian Corals. quantities as well as that of the gas occluded in the Lenarto iron and that of manufactured iron: Virginia Iron. Lenarto Shoeing -—— —_~—_—_—— — Iron. Nails. I. its III. Total. Hydrogen ... ... ...| 22°12 | 10°52 | 819 | 35°83 || 85-68 || 35-0 Carbonic oxide ... ...| 15°99 11°12 11°22 38°33 4°46 50°3 Carbonic acid ... ...} 7°85 1:02 0°88 9°75 — eal INGTTRGEN — Goa G00. aoa OVO | WOES) 8°58 16°09 9°86 7:0 52:02 | 24°11 23°87 |100°00 | 100-00 || 100-0 These results unfortunately do not admit of very exact comparison, as only a portion of the gas extracted from the Lenarto iron was quantitatively examined. Although the relative quantity of hydrogen in the Augusta iron is much less than in the Lenarto iron, it amounts to 1-4 times the volume of the iron, while manufactured iron under ordinary pressure takes up only 0:42 to 0:46 of its volume of this gas. Mallet’s results have shown that Graham’s view, that the pre- dominance of carbonic oxide among the occluded gases is indicative of telluric origin, is no longer tenable. In connexion with these differences in composition of the gases constituents of meteorites, it is interesting to notice that the observations of Secchi and Huggins have shown that carbon plays an important part in certain cosmical regions, although the spectroscopic evidence in the case of this element is as yet less definite than it is in regard to hydrogen. 1869 (and 1871). Trenton, Washington Co., Wisconsin.* An additional fragment of this meteorite, weighing 164 lbs., was found in 1869; and another, weighing 35 lbs., was dug up in 1871. All the six fragments (143 lbs.) now collected were found in the same field. (To be continued in our next Number.) IIl.—Descrirtrions or New Species oF COYsTIPHYLLUM FROM THE Drvontan Rocks oF NortH AMERICA. By H. Atteyne Nicuorson, M.D., D.Sc., F.R.S.E., Professor of Biology in the College of Physical Science, Newcastle-on-Tyne.” (PLATE I.) O less than seven species of Cystiphyllum have already been \ recorded as occurring in the Devonian Rocks of North America ; viz. C. vesiculosum, Goldf., C. Senecaense, Billings, C. grande, Billings, C. sulcatum, Billings, C. Americanum, Edw. and Haime, C. aggregatum, Billings, and C. mundulum, Hall. To these I have now to add the following four species, all of which have been obtained by me from the Devonian Formation of Canada and Ohio. (5) J. rae Mineralogy and Chemistry, 348.—J. A. Lapham. Am. Jour. Se., lil. 6 * Read before the British Association, Section C., Belfast, 1874. Series. Geol. Mag.1870. veo CN NOR rence of Cystiphyllum. ( Devoman ) G.H Ford Species Prof. H. A. Nicholson—On some New Devonian Corals. 31 CystipHyLLuM Ountornsz, Nicholson. - Pl. I. Figs. 2, 2a. — Spec. char.— Corallum small, turbinate, simple, sometimes twisted, but usually straight, or slightly curved. Length of corallum usually about six lines, varying from four to nine lines; the calice varying in diameter from four to six lines. Hpitheca distinct, marked with longitudinal striz, and usually showing well-marked annula- tions and constrictions of growth. No calicular gemmation, nor radiciform prolongations of the epitheca. alice not oblique, very deep, generally occupying from one-third to two-thirds of the entire length of the corallum, not flattened below. The interior of the calice shows more or less distinct septal striz, thirty or more in number. Vesicles of the interior small. The dimensions of an average specimen are: length, eight lines ; diameter of calice, six lines ; depth of calice, four lines and a half. This pretty little species is readily distinguished from all others previously described, although the specimens upon which it is founded are much silicified, and do not exhibit some points of structure as well as could be desired. The species is characterized by its uni- formly small size, its deep, pointed, and not oblique calice, the presence of distinct septal striz, and the absence of radiciform pro- longations of the epitheca. It is most nearly allied to C. mundulum, Hall, from the Devonian of Rockford, Iowa (Twenty-third Annual Report on the State Cabinet, 1874), but is distinguished by its smaller size, the smaller number of its septa, and its much deeper and more pointed calice. Locality and Formation—Common in the Corniferous. Limestone, Columbus, Ohio. CysTIPHYLLUM squaMmosuM, Nicholson. Plate I. Figs. 4, 4a, 46. Spec. char.— Corallum simple, turbinate, but extraordinarily flattened. Dorsal surface greatly expanded, nearly or quite flat; lateral margins straight, and forming an angle with the curved ventral surface, which is much reduced in size. Calice extra- ordinarily oblique, making an angle with the dorsal surface of not more than 10° or 12°, very shallow and widely open, its deepest point being situated at a point about one-third of the length above the base. Vesicles of the interior about one line in diameter. Owing to the fact that all the examples of this coral which have been examined are converted into orbicular silica, the characters of the septal striz and epitheca cannot be determined. Some speci- mens exhibit the same form of calicular gemmation as is seen in C. vesiculosum,—that is to say, the coral continues growing for a certain period, and then sends up a fresh calice from the centre of the old one. In this species, however, the new calice, instead of being continued in the axis of the coral, is directed more or less nearly at ~ right angles to the plane of the old calice. The dimensions of the largest individual observed are as follows : Length, measured along the dorsal surface, twenty-four lines; length, measured along the ventral surface, seven lines; greatest thickness, seven lines; diameter of calice, twenty-one lines; greatest. depth of 32 Prof. H. A. Nicholson—On some New Devonian Corals. calice, six lines. In the smallest individual observed the dimensions are: Length, measured along the dorsal surface, thirteen lines ; length, along the ventral surface, four lines ; greatest thickness, four lines; diameter of calice, ten lines ; greatest depth of calice, two lines. This wonderful species is readily distinguished by its extra- ordinarily flattened and scale-like form, due to the extreme obliquity and shallowness of the calice, the flattening of the dorsal surface, and the almost total disappearance of the lateral surfaces. No other species of the genus known to me even approaches C. squamosum in these characters, and these are, therefore, of themselves sufficient to characterize the species. All the specimens I have seen are covered with remarkably large and fine “ Beekite-markings,” and the more minute characters of the coral are thereby entirely obscured. Locality and Formation.—Corniferous Limestone, Columbus, Ohio. CYsTIPHYLLUM FRUTICosUM, Nicholson. Plate J. Figs. 3, 3a. Spec. char.—Corallum aggregate, composed of numerous cylin- drical, straight or slightly flexuous corallites, growing side by side, but not connected by epithecal processes or expansions, and often forming colonies of several feet in circumference. Corallites about three lines in diameter, or rather less, and placed usually at intervals apart of two lines, less or more. LEpitheca thin but distinct, marked with very numerous fine encircling striz and fainter vertical striz, as well as with irregular annulations and constrictions of growth. Calice moderately excavated, from one and a half to two lines in depth, exhibiting numerous bulle, sometimes with septal strize near the margin. Internal structure wholly vesicular, the vesicles having a diameter of from half a line to nearly one line. With the exception of the present very remarkable form, and the equally singular C. aggregatum of Billings, all the species of Cystiphyllum are simple. Its compound character is, therefore, of itself sufficient to distinguish C. fruticosum from all the hitherto recorded species of Cystiphyllum except C. aggregatum, and from this it is separated by its wholly different form and mode of growth. In its general appearance C. fruticosum presents the closest possible resemblance to Diphyphyllum arundinaceum, Billings, with which it not uncommonly occurs associated; but its internal structure separates it at once, and shows it to be a genuine Cystiphyllum. Locality and Formation.—Not uncommon in the Corniferous Lime- stone of the Townships of Wainfleet and Walpole, Ontario. CysTIPHYLLUM SUPERBUM, Nicholson. Plate I. Fig. 1. Corallum of large size, simple, turbinate, very broadly expanding. Calice extremely large, circular, moderately deep, and very oblique, making an angle of about 50° with the dorsal surface of the corallum, and one of about 150° with the ventral surface. The septa are marked by distinct rows of bullz or vesicles, which radiate from the bottom of the cup, and are not less than one hundred and forty to one hundred and fifty in number. The vesicles are small, not exceeding half a line in diameter in the circumferential portion of the coral. Epitheca well developed, with numerous fine encircling Geol 1875) ee tees AGE BEM oe Pe Sig BP AAD Spe Py gE ake ci > Bre 2 a Ss ~ : g * = ote ” . . es a eee * OA er EDS eS A ee Foe eee Me eee Foseeace sh Rye ea Rae: ‘ = : 5 s ¢ 5 IP an PE o,: < Pe aa ERIN Usgtsesieie sae a ceagee: Boge ay mus ts 2 he ; ; A it gM Oe ee eS LU Ree 2 er ieee ’ : San : Ae Be os ie oA cay Pe %, z Heceuary . é eat OD gran ES as faves ise RR TAD Scams none cca e FENCE SIS Ge Rod fy = ee : ge Pye ; ‘ a Boiled oes ie ea? a g Ses See eS ieee } i I | { t at PP ee 5 ae. Mintern Bros imp Devoman Polyzoa. Prof. H. A. Nicholson—New Paleozoic Polyzoa. 33 strie and annulations of growth. Owing to the obliquity of the calice, the dorsal surface of the corallum is nearly twice as long as the opposite or ventral surface; and the greatest thickness is attained at a point situated about three inches above the base, or at about one-half of the total length. The only individual observed had the following dimensions: Length measured along the dorsal surface, six inches; along the ventral surface; three inches and a half. Greatest thickness, at three inches above the base, about three inches and a half. Diameter of calice, four inches and a half; depth of calice about one inch. This fine species is most nearly allied to C. vesiculosum, Goldfuss ; but it is distinguished from this and all other recorded species of the genus, by its comparatively gigantic dimensions, its very rapid expansion from the base upwards, and the striking obliquity of the calice. When viewed in profile (as in Pl. I. Fig. 1), its outline appears to be somewhat rhomboidal. This, however, is not a natural or essential appearance, but is due to the fact that the dorsal surface, in the individual examined, is abruptly geniculated at about the middle of its length. There is, however, no reason for supposing that this feature would prove to be a normal one in the species. Locality and Formation.—Hamilton Group, Arkona, Township of Bosanquet, Ontario. EXPLANATION OF PLATE I. Fic. 1.—Cystiphyllum superbum, Nich., viewed in profile, of the natural size. The single dark line shows the outline of the calice as seen in a front view. Fie. 2.—Cystiphyllum Ohioense, Nich., of the natural size. 2a. Calice of the same viewed from above, of the natural size. Fie. 3.—Fragment of Cystiphyllum fruticoswm, Nich., of the natural size. 3a. Calice of one of the corallites of the same, slightly enlarged. Fic. 4.—Cystiphyllum squamosum, Nich., viewed from the front, of the natural size. 4a. Profile view of the same. 46. Profile view of another individual of the same, in which a secondary calice has been produced at right angles to the primary ealice. _ All these specimens are silicified, and are covered with “ Beckite- markings.” 1V.—Desceriptions oF New Sprcres anp oF A New GENUS OF PotyzoA FRoM THE Patafozoic Rocks or Norrse AMERICA. By H. Atteynse Nicuoxson, M.D., D.Sc., F.R.S.E., Professor of Biology in the College of Physical Science, Newcastle-on-Tyne. (PLATE II.) Genus HeteRopicryA, Nicholson. Polyzoary (?) forming a simple, flattened, unbranched, two-edged frond, with sub-parallel sides, consisting of two series of cells, the bases of which rest upon opposite sides of a thin longitudinally- striated central membrane or laminar axis, from which they pass obliquely outwards in opposite directions. The cells open in longi- tudinal rows on the two flat or slightly convex surfaces of the frond, and have the form of more or less cylindrical tubes, which are septate or are divided transversely by a series of well-developed tabule. In the only species known the cells of a few. of the median rows of DECADE II.—VOL, I1.—NO. I. 3 o4 Prof. H. A. Nicholson—New Paleozoic Polyzoa. the frond are straight, but those of the lateral rows are oblique. Cell-mouths unknown. In most essential characters, and in general appearance, the genus Heterodictya entirely resembles Ptilodictya. We have, however, the very anomalous and very important feature, that the cells in the present genus are as thoroughly and as regularly tabulate as the coral- lites of Chaetetes or Favosites. ‘This clearly necessitates the removal of Heterodictya from Ptilodictya, and establishes a very interesting transitional link between the Polyzoa and the Tabulate Corals. I am only acquainted with a single, exceedingly large, species which can certainly be referred here. I should however, suspect that Ptilo- dictya (Flustra) lanceolata, Goldfuss, will very probably turn out to be an example of this genus. Heteropictya GIGANTEA, Nicholson. Plate II. Figs. la—le. Polyzoary forming a single, flattened, unbranched, two-edged frond, the dimensions of which are unknown, though certainly very great. The largest specimen observed expands gradually in width in proceeding from the base upwards. Its length is three and a quarter inches; the breadth of the broken base is nine lines, and the breadth of the broken distal extremity is fifteen lines. Both ends of this fragment are broken away, and its total length, when perfect, may be estimated with every probability as having been at least half a foot, with a width of not less than two inches. The edges of the frond are quite sharp, and its width in the centre is two lines or a little more. Its cross-section is thus acutely elliptical, the two poriferous surfaces being gently and regularly convex, without any central angulation. The frond is completely divided into two halves by a central laminar axis, which is marked with’ longitudinal strie, conforming with the rows of cells, but does not exhibit arched transverse strie. The cells are arranged in longitudinal rows, in three series. The first series is central, and consists of a few rows in which the successive cells are themselves longitudinal, and are not obliquely disposed. ‘The remaining two series of rows are lateral, and each consists of a number of rows in which the cells are directed obliquely outwards and upwards as regards the margin of the frond in the direction of the row itself (Pl. IJ. Figs. 1b and le). The general arrangement of the cells is thus penniform. There are about six rows of cells in one line measured transversely, and thus there are about ninety rows altogether at the wider end of the frond. There are four or five cells in the space of one line measured longi- tudinally, and the cells are alternate or sub-alternate in contiguous tows. ‘The cells have the form of cylindrical tubes directed upwards towards the surface at an angle of about 70° with the laminar axis. Each tube is partitioned off transversely by well-developed tabulee, of which there are five or six in the space of one line, some of them not quite extending across the tube, but the most of them complete. The bases of the cells, as seen by decortication of the laminar axis, have mostly the form of narrow ovate slits. The free surfaces of the frond, and consequently the characters of the cell-mouths, are un- known. Prof. H. A. Nicholson—New Paleozoic Polyzoa. 35 This remarkable form resembles Ptilodictya lanceolata, Goldfuss, in its general shape, and in the penniform arrangement of its cells ; and, as before remarked, it seems by no means impossible that the latter species may ultimately be shown to possess tabulate cells, and thus belong to the genus Heterodictya. Under any circumstances, however, P. lanceolata is separated from the present form by its comparatively diminutive dimensions; and I know of no other recorded species of the genus Ptilodictya with which Heterodictya gigantea, apart from its internal structure, could be confounded. Locality and Formation.—Rare in the Carboniferous Limestone of Jarvis, Township of Walpole, Ontario. (The specimens from which the above description is taken were collected by Mr. George Jennings Hinde, F.G.S8.) PrinopicTya cosciniForMis, Nicholson. Plate II. Figs, 2-26. Polyzoary rooted by a strong footstalk, which is partly striated ‘longitudinally, partly covered with the apertures of cells inter- spersed with numerous minute interstitial tubuli. At the summit of the footstalk the frond divides into a number of flattened branches, which ultimately divide and coalesce with one another, so as to form a network with oval meshes. The branches of this network are flattened and sharp-edged, with gently rounded surfaces. Their - cross-section is acutely elliptical, their thickness in the middle being half a line, their width being two lines, and the meshes which sepa- rate them being about two lines in their long diameter. The sharp borders of the branches are marked with longitudinal and oblique strie, interspersed with the apertures of minute tubuli, a complete marginal ring of this nature surrounding each mesh of the terminal network. The cells are not disposed in longitudinal rows separated by elevated lines, but are arranged quincuncially, so as to form two series of intersecting curved diagonals. The cell-mouths are regu- larly oval, each with a distinct rim, not elevated above the general surface, about six or seven of them occupying the space of one line measured diagonally. The interspaces left by the apposition of the oval cell-mouths are entirely filled by very minute interstitial tubuli, the apertures of which are circular or oval. This beautiful species forms in many respects a transition between the typical Ptilodictye and the thin reticulated expansions to which the name of Ciathropora or Coscinium has been applied. It is dis- tinguished by the following more important characters: 1. The mode of growth is peculiar. The polyzoary springs from a strong and thick root or footstalk, from the top of which proceed several branches, which do not lie in the same plane, but are so disposed as to form a tuft or cluster similar to that of such a recent form as Flustra truncata. These branches sub-divide, and their divisions inosculate so as to form a network, the characters of which are quite similar to that of Clathropora. 2. The cells are not arranged in longitudinal rows separated by elevated lines. 3. The cell-mouths are oval, and are quincuncially disposed. 4. All the interstices between adjacent cells are filled up with numerous minute intersti- 36 Prof. H. A. Nicholson—New Palwozoic Polyzoa. tial tubuli, similar tubules being present on the striated margins of the branches, and over considerable portions of the footstalk. The only example of this species that I have seen is growing upon Heliophyllum Halli, to the exterior of which the footstalk is attached by a widely expanded base. Locality and Formation.—Bartlett’s Mills, Arkona, Township of Bosanquet, Ontario. In the Hamilton Formation. FeEnesteELLA Davipsont, Nicholson. Plate II. Figs. 3-30. Frond small, flabelliform, the branches (“interstices”) keeled on both sides with very high, thin, and sharp-edged carinz. Three or four branches in the space of one line, dividing dichotomously, usually with great regularity, at intervals of from two to three lines. Both the branches and the keels are more or less wavy or sinuous, sometimes as regularly so as in some Retepore ; whilst the dissepi- ments are very wide, deeply sunk beneath the level of the celluli- ferous surface of the frond, and presenting the appearance of being formed by anastomosis of the branches. 'The dissepiments are fully one-third of a line in width, and do not carry cells. The fenestrules are oval, about one-third of a line in length, and slightly less than this in width; about two of them in the space of one line measured longitudinally, alternately placed in contiguous rows. The cell- mouths are rounded or transversely oval, about three of them oppo- site to each fenestrule. Non-poriferous side of the branches smooth, with the same thin, sharp, and prominent keel as exists on the celluliferous side. This species, in its mode of growth and division, as well as in the sharpness of the carina between the rows of cells, strongly resembles Fenestella Miileri, Lonsdale; but the latter is stated to possess narrow and slender dissepiments, placed two lines apart, with fenestrules five or six times longer than wide, about twelve pores going to a fenestrule. The corresponding characters in our species are so strikingly different, that, in spite of the superficial resemblance, I feel fully justified in separating it from F. Milleri ; and I have great pleasure in dedicating it to my friend Mr. Thomas Davidson, F.R.S. F. Davidsoni ig distinguished by its regularly dichotomising branches, with prominent sharp-edged keels on both sides; the undulated character of the branches; the deeply sunk position and great width of the dissepiments, which carry no cells, and look as if formed by anastomosis of the branches; and the oval, slightly longer than wide fenestrules. In the general aspect of the celluli- ferous surface and the sinuous course of the branches, the species makes a close approach to some species of the genus Retepora; but the presence of non-poriferous dissepiments and the existence of a keel separating two rows of cells seem to justify its reference to the genus Fenestella, of which, however, it cannot be regarded as a typical member. The keels are so prominent, that specimens, espe- cially when seen from the non-celluliferous side, often exhibit nothing except the carinz projecting above the matrix. ; Locality and Formation.—Hamilton Group; Bartlett's Mills, near Prof. H. A. Nicholson—New Paleozoic Polyzoa. 37 Arkona, Township of Bosanquet ; and cutting on the Grand Trunk Railway near Widder, Township of Bosanquet, Ontario. Crramopora Huronensis, Nicholson. Plate IT. Figs. 5, 5a. Polyzoary forming small patches or crusts, of a rounded or irregular form, from one-quarter to one-third of a line in thickness, growing parasitically upon foreign bodies, and rarely exceeding three or four lines in diameter. Cells radiating from a central or excentric point, about six in the space of one line, partially im- mersed, and elevated towards their mouths, which, when perfect, are of a sub-triangular or crescentic form. This species resembles young examples of Ceramopora Ohioensis, Nich. ; but is distinguished from adult examples of the same by forming small parasitic crusts, composed of a single layer of cells, which radiate from a generally central point. The cells are also to a greater extent immersed, and are not in such close contact. From C. incrustans, Hall, the present species is separated by its smooth, not nodulose or tuberculated surface. (C. Huronensis somewhat resembles the figures of Berenicea (Diastopora?) irregularis, Lonsd. ; but the latter is stated to possess round cell-mouths, and the published description is not sufficiently detailed to allow of a close comparison. Locality and Formation—Hamilton Group, Arkona, Township of Bosanquet, Ontario. Growing on the exterior of Cystiphyllum vesi- culosum, Goldfuss, and Heliophyllum Halli, Edw. and H. RETEPORA TRENTONENSIS, Nicholson. Plate II. Figs. 4-40. Polyzoary forming a fan-shaped expansion, composed of slightly divergent, sub-parallel branches, which have a width of about one- third of a line. The branches are more or less sinuous in their course, and divide dichotomously at short intervals, usually uniting with adjacent stems so as to form an open network, the fenestrules of which have an approximately oval shape, and are from one to two _ lines in length. The cells have the appearance of being oblique to the surface, and there are four, five, or six rows of them in a branch. They are also present upon all the areas formed by the anastomosis and conjunction of contiguous branches. The cell-mouths are poorly preserved, but appear to have a long oval shape. ‘The non- celluliferous side is strongly striated with wavy or straight longi- tudinal striz or ridges. This species is only known to me by several more or less im- perfect specimens, from which some of the essential characters cannot be determined. It appears to be a genuine Retepora, and to be most nearly allied to R. Hisingeri, M‘Coy; but the fenestrules of the latter are much smaller, and more regular in their dimen- sions, whilst the non-poriferous side is minutely granular. In R. Trentonensis, on the other hand, the fenestrules are large and irregular, and the non-poriferous side is strongly striated. In the general shape of the frond, it resembles some of the later Feneséella, such as F. laxa, but it is clearly not referable to this genus. Locality and Formation,—Trenton Limestone, Peterborough, On- tario. Collected by Mr. George Jennings Hinde, F.G.S. 38 J. Clifton Ward—Modern Vuleanicity. EXPLANATION OF PLATE Ii. Fic. la.—Heterodictya gigantea. A broken frond, of the natural size. The specimen is split longitudinally along the line of the central laminar axis, and thus shows the bases of the cells. j Fic. 10.--Portion of the same, near its smaller end, enlarged to show the penniform arrangement of the cells. Fre. 1¢.—Transverse section of the frond, of the natural size. Fic. 1d.—A few of the cells of the same viewed in profile, showing the tabule. Enlarged, Fic. le.—A small portion of the surface greatly enlarged, showing the shape of the bases of the cells. On the left hand side of the figure, a portion of the longitu- - dinally striated laminar axis is preserved. ; Fic. 2.—Ptilodictya cosciniformis, a broken specimen growing on Heliophyllum Halli. Of the natural size. Fic. 2a.—Portion of the same enlarged, showing the meshes of the network, and their striated borders. Fre. 26.—A portion of the same still further enlarged, showing the form and arrange- ment of the cells and the interstitial tubuli. Fic. 3.—Fenestella Davidsoni ; a small portion ef the non-poriferous side. Of the natural size. Fic. 3a.—Portion of the same enlarged. Fie. 34.—Pertion of the poriferous side of another specimen of the same, enlarged. Fie. 3c.—Small portion of a branch of another example of the same, greatly enlarged. Fic. 4.—Fragment of Retepora Trentonensis, of the natural size. Fre. 4a.—Portion of the same enlarged, showing the arrangement of the cells. Fre. 46.—Portion of another example of the same, enlarged; showing the striated non-poriferous surface. Fic. 5.—A small crust of Ceramopora Huronesis, growing on Heliophyllum Hath, enlarged, Fic. 5¢.—Portion of the same, greatly enlarged, showing the form of the cells and cell-mouths. V.—Mopern ‘Voutoaniciry.’! By J. Currron Warp, Assoc. R.S.M., F.G.S., of H.M. Geological Survey. fee theory proposed of late years by Mr. Mallet to account for volcanic and earthquake phenomena, while having a charm about it from its very simplicity, is one which must nevertheless meet with very decided criticism from geologists. Mr. Mallet sees ‘linked together, as parts of one grand play of forces,” the elevation of mountain-chains, the production of volcanos, and the origination of earthquakes. His theory, however, necessitates the following suppositions :— 1. “That the geological doctrine of absolute uniformity cannot be true as to Vuleanicity. . . . Its development was greatest at its earliest stages.” (p. 75.)! 2. That the movements of elevation and depression at the present time are “slow and small,”’ but these, ‘at a much remoter epoch, acted upon a much grander and more effective scale.” (p. 62.)} On page 47' the “stratigraphic geologist” is described as one who discerns “‘a change in the order or character” of the ‘‘fused masses which have come up from beneath. He sees immense outpourings of granitoid or porphyritic rocks that have welled up and overflowed the oldest strata. . . . Later he sees huge tables of basaltic rock 1 Tntroductory Sketch to Palmieri’s Vesuvius. J. Clifton Ward—Modern Vulcanicity. 39 poured forth over all.” Such products, which the author says are “commonly called plutonic,” he distinguishes from those of the volcano by being “not explosive.” Does it not seem that Mr. Mallet is here making a difference between action from below in the early stages of geologic history and that action in modern and recent geologic times which does not exist in fact?! Volcanic products, both sub-marine and sub-aerial, of the most unmistakable character, occur in rocks of all ages down to the base of the Lower Silurian. Basaltic lavas, in which the component minerals seem to have crystallized in the very same order and under the same conditions as in modern flows, have now been traced back to periods of the world’s history before, apparently, vertebrate life came into existence, and when the very ancient order of Graptolites flourished. There is nothing to mark the old sub- aerial volcanic products of Cumbria, and the sub-marine volcanic products of Snowdonia, from those of recent sub-aerial or sub-marine voleanos, except the metamorphism which the older rocks have been inevitably subject to, but which has seldom succeeded in obliterating their original character as a whole. There would seem to be as little doubt that ‘ Vulcanicity’ presented phenomena of an ‘ explosive’ character, characteristic of the volcano, in the English Lake-district during the middle of the Lower Silurian, as that such phenomena now occur on the shores of the Bay of Naples. But, if this be so, since our geologic history is, properly speaking, bounded by the lowermost of known sedimentary formations, it surely is not safe to say that there is any essential difference between modern ‘ Vulcanicity’ and that which prevailed at the earliest stages of the Harth’s history. Let us now examine a little into the truth of Mr. Mallet’s suppo- sition that “the great masses of the mountain-chains were elevated” during the “earliest stages” of Vulcanicity. He evidently regards it as unlikely that great movements of elevation and depression are now taking place, such as result in the formation of mountain chains or in the depression of such beneath the waters of the ocean, although he does not deny that such chains “may be possibly increasing in stature year by year, or at times; but in any case at a rate almost infinitesimally small in its totality over the whole earth to that with which their ridges were originally upreared.” (p. 63 op. cit.) Are there, however, any legitimate reasons for supposing that the movements of elevation and depression were in the earlier course of geologic history more rapid and sudden than at present? Is there any evidence, for instance, that in times so far back as the Silurian, great elevations or depressions of land took place at all rapidly ? Can we with any show of truth assign the origin of the leading chains of mountains to the earliest geologic ages? ‘To answer these questions aright, we must consider denudation as well as upheaval and depression. Prof. Ramsay has shown that in Wales the many thousand feet of strata formed during the Lower Silurian period were upraised, contorted, cleaved, and extensively denuded before the 1 See also Mr. Scrope’s criticism in Geox. Mac. January, 1874, page 31. 40 J. Clifton Ward—Modern Vulcanicity. Upper Silurian beds were deposited upon them.- Can any one con- ceive of such a denudation as is here implied being effected during a more or less speedy movement? A sweep of waters during some rapid action could not have effected the truncation of many thousands of feet of contorted strata, as Mr. Mallet will probably allow. But given such an action as is now going on around our coasts, and given long periods during which denudation could take effect upon land being slowly upraised, and then as slowly depressed, such an amount of work done between the deposition of the Lower and Upper Silu- rian strata can be realized. Or to take another example. In Cumber- land, conglomerates assigned to the Upper Old Red, or perhaps with more truth to the base of the Carboniferous, lie unconformably upon Upper Silurian beds, upon the Cumbrian Volcanic Series, and upon the Skiddaw Slate. At the close of the Upper Silurian period, the Skiddaw Slate of the Lake-district was probably buried beneath at least 12,000 ft. of voleanic rocks and some 14,000 ft. of Upper Silurian strata; yet between the period of deposition of the upper- most of the Kendal Silurians and the formation of the Conglome- rate of Mell Fell, there must have been a removal by denudation of this 26,000 ft. of rock, to say nothing of any thickness of Skiddaw Slate which may have been swept away also. I believe that this denudation took place during the fitst upheaval of the present Lake- district group of mountains, and it is hard to conceive of any pro- cess by which it could have been effected other than the slow but sure gnawing and planing action of the sea upon the slowly rising tract, and the action of atmospheric powers upon those parts fairly above the sea-level. Such a denudation, carried on by such means, gives a forcible idea of the length of the Old Red Sandstone period, and there exists somewhere a thickness or an extent of strata formed during that period, strictly correlative with the amount of denudation produced. If we are to believe that the denudation of a great thick- ness of rock could be effected during a rapid rate of elevation, we must also believe that a great thickness or extent of strata could be as rapidly deposited. But we know from fossil evidence that sedi- mentary deposition has been in most, if not in all cases, exceedingly slow; therefore the denudation must have been proportionately so. With regard to the existing mountain-chains, evidence is not far to seek, showing that in the main their formation dates from recent geological periods. If all such giant chains as the Alps or the Himalayas could be proved to be of early Palaeozoic origin, and such diminutive mountain groups as those of Wales and Cumberland to be of recent origin, then indeed one might be inclined to argue that forces which raised the former had well-nigh spent their power, and were now only equal to producing slow elevations of 2000 or 3000 feet. But when oftentimes the very reverse of this is found to be the case, when the mountain groups of Cambria and of Cumbria are representatives of some of the earliest tracts of land, when the rocks forming the bulk of the Alps and the Himalayas were being formed 1 Thickness of Upper Silurian in the Kendal district, according to Mr. Aveline. R. J. L. Guppy—West Indian Tertiary Fossils. “41 beneath oceanic waters long ages after the mountains of Wales and Cumberland first began to take form, and when therefore the prin- cipal mountain-chains are but infants in age as compared with the Snowdon of Wales and the Scafell of Cumberland, it is surely illogical to assume that the great movements of elevation and de- pression were confined to the earliest stages of Vulcanicity. - There is another statement made by Mr. Mallet which must strike every working geologist. Geology, it is said, must make poor pro- gress, “until all who profess to be geologists shall have learnt that, to make sound progress, they must first become mathematicians, physicists, and chemists.” Now no one will deny that geology derives very material assistance from every other branch of science, the students of science forming together one great mutual help society ; but to affirm that “sound progress” can only be made by the geologist when he becomes mathematician, physicist, and chemist, is to withhold any hope of progression from the many, and confine it wholly to those few comprehensive minds which arise but seldom on the intellectual horizon. One of the great charms of natural science is the way in which it developes the powers of observation, and of reasoning logically on such observation, and it gives a noble in- dependence of thought which trusts to nature, and cares not for human authority merely as such. Surely many, if not most of our leading geologists, who have made our science to progress so rapidly, were neither mathematicians, physicists, nor chemists, much less all three together; but they have been and are careful observers, loving students of nature, ever willing and anxious to receive help from the mathematician, the physicist, and the chemist, but not willing to allow these scientists to pervert ascertained facts in order to accommodate them to their own special modes of thinking. For example, we may suppose the case of a mathematician desirous of advancing the science of geology by some new theory worked out by such abstruse mathe- matical reasoning that the simple field-geologist could not follow the line of argument; and if the latter has reason to suppose that the facts upon which the argument is based be correct, he feels bound to acquiesce in the result. Should, however, the geologist find that the mathematician resolutely refused to believe evidence on some special point founded on the careful observation of nature— such as the production of striz on rock-surfaces by ancient glacial action—the geologist might well hesitate to accept the mathematical conclusions upon some oéher subject at the basis of which accurate observational powers should have been employed. VI.—SupPLEMENT To THE Paper on West InpD1IAN Tertiary Fosstts.* By R. J. Lecumere Guppy, F.L.S., F.G.S., etc. HE descriptions of two of the species enumerated in my paper on the Tertiary Fossils of the West Indies having been acci- dentally omitted, the defect is now supplied. 1 See the Grou, Mac. Decade II. Vol. I. (October Number), 1874, p. 483. 42 Notices of Memoirs— Leda clara. Grou. Mac. 1874, Decade II. Vol. I. Pl. XVII. Fig. 1. Subelliptical, lanceolate, nearly equilateral, somewhat but not extremely rostrated. Disk smooth, shining; valves with a few fine close regular concentric riblets perceptible near the anterior angle, where an indistinct sulcus runs upwards towards the umbo. No distinct escutcheon. Lunule narrow, indistinctly defined. Umbones prominent. Ventral margin slightly angulated at about a third of its length from the posterior point, where an obscure carina runs to the margin from the umbo. Length 12 mill., height 6, thickness about 4mm. Miocene, Jamaica. In shape somewhat like LZ. nasuta. It is rather difficult to describe the smooth plain species of this genus; their differences being most generally noticeable in shape, extent of rostrum, ete. The following species have been already described from West Indian Tertiaries :— Leda Packeri, Forbes, Eocene, Barbados. », ‘%meognita, Guppy, Eocene, Trinidad. » bisulcata, Guppy, Upper Miocene, Jamaica. » illecta, Guppy, Pliocene, Trinidad. » perlepida, Guppy, Pliocene, Trinidad. Three species of Nucula have been recorded from the same formations. Ditrupa dentalinum. Grou. Mac. 1874, Decade II. Vol.I. Pl. XVI. Fig. 11. Tube clavate, curved, slightly irregular in diameter, gradually increasing from the smaller end, which is annulate, becoming smooth towards the middle of the shell; the lower half smooth, shining, rather suddenly thickened near the aperture, to form which it as suddenly contracts to a diameter not greater than that of the smaller third of the tube. There are no very distinct characters by which to separate this annelid case from D. planum of the Huropean Kocene. Ihave thought it as well, nevertheless, to indicate its presence in the Jamaican Tertiaries under a provisional name. Crassinella. Thave proposed this name in substitution for that of Gouldia, pre- occupied for a genus of birds. The typical species are Cr. pacifica and Or. martinicensis; the latter occurs in the Pliocene of Trinidad. INKOEESTOAMS Opgy AMi IMO S7S «Sur ta CorréLatTion DES Formations CAMBRIENNES DE LA Beterque ET pu Pays pe Gauss.” By Prof. G. Drwarauz. (From the Bulletins of the Royal Academy of Belgium, 2nd series, tom. xxxvii. no. 5, May, 1874.) ‘Translated by G. A. Lupour, F.G.S. FTER an excursion to Wales in the autumn of 1872, which I undertook in order to study the petrographical characters o1 the oldest formations of that region, I announced to the Academy G. Dewalque on the Cambrian Rocks. 43 (Bull. 2nd ser. tom. xxxiy. p. 424) that a comparison between them and the analogous formations of our country had enabled me to establish the parallelism of the subdivisions of the Cambrian rocks in both countries. I then hoped to be soon able to draw up a detailed communication on the subject, but my health has until now prevented my doing so. As I have had occasion to lay before my pupils the results of my observations, I think it may be useful now to make known the parallelism which I believe I have determined. I have long ago regarded our “Ardennais” formation as Cambrian, notwithstanding contrary assertions, The Cambrian of North Wales is represented, according to most authors, by the Harlech grits, the Llanberis slates, the Lingula flags, and the Tremadoc slates. The two first names are applied to two series which I consider as con- temporaneous : their characters bear the same relations to each other as those of our two “devilliennes” bands of Monthermé and Furnay, which they exactly resemble, except that our quartzites are there often replaced by conglomerates. The slates of Furnay and those of Llanberis are absolutely identical. | Our “systeme revinien” corresponds quite as exactly to the Lingula flags ; the likeness of the rocks is perfect. With regard to our “systeéme salmien,” it must be noted that its lower limit is not very clear, and that it has usually undergone a peculiar metamorphism, which scarcely allows one to hope to meet with similar rocks in Wales. I think I am justified in placing it on the horizon of the Tremadoce slates, because of the position occupied by both these formations between the ‘‘syst¢me revinien” or Lingula flags and the great dislocation which terminates the Cambrian period. It will be noticed that the Tremadoe system is a local formation, like our “‘systeme salmien.” Some geologists may find these resemblances insufficient to esta- blish the parallelism in question. I think I can promise that the primordial fauna will be found in our “systéme revinien.” I have just recognized, in a specimen which had long been looked upon as indeterminable, a plant which is characteristic of the Fucoidal grits of Scandinavia, Hophyton Linneanum, Tor.; it comes from the “revinien” of Stavelot. This genus is also found in the Lingula flags of England. Some years ago I had discovered a Dictyonema at Spa, at the base of the “‘Salmien.” I have several times taken my pupils to this spot, and last year several specimens were found. Since then I have assured myself that it is the Dictyonema sociale, Salt., of the Upper portion of the Lingula flags (which would tend to alter the inferior limit of the “Salmien”’). I may add that I have met with the same species in the same position at Ruy, during the excursion which I made last spring with my pupils. 44 Reviews—Danas Manual of Geology. | REVIEWS. I.—Manvat or Guotoey: Treating of the Principles of the Science with special reference to American Geological History. By James D. Dana, Silliman Professor of Geology and Mineralogy in Yale College, Foreign Member and Wollaston Gold Medallist of the Geological Society of London. Illustrated by over eleven hundred figures and a chart of the world. Second Hdition, 1874. 8vo. pp. 828. (New York: Ivison, Blakeman, Taylor, and Co. London: Triibner and Co.) HE name of Professor Dana, as a zoologist, a geologist, and a mineralogist, is known and honoured, not only in America, but throughout Europe. He occupies in the United States the same relation to the student of geological science that Lyell has so long maintained in Hngland. He is the most celebrated teacher in America, and his books are adopted wherever geology and minera- logy are taught. Nearly fifteen years have elapsed since the first edition of this manual appeared, during which time geological progress (especially in the United States) has been very considerable. Since November, 1862 (when the first edition of this work was really completed), the Surveys of California, the Territories over the summit and slopes of the Rocky Mountains, those of Minnesota, Iowa, Missouri, Louisiana, Tennessee, Illinois, Indiana, Michigan, Ohio, North Carolina, and New Hampshire, in the United States, and the Provinces of Canada, New Brunswick, Nova Scotia, and Newfoundland, have been carried out and their Reports published. These Surveys have greatly extended our knowledge of American rocks and mineral products, besides affording aid towards a deeper insight into principles and a clearer comprehension of the system that pervades the earth’s structure. Besides all this, large contributions to paleontology have been made by some of the Reports, and most prominently by the new volume of the New York series by James Hall; the volumes of the Illinois Survey by Meek, Worthen, Newberry, and Lesquereux ; of the Ohio Survey by Newberry and Meek; of the California Survey under J. D. Whitney, by Meek and Gabb; of the Survey of the Territories under F. V. Hayden, by Meek, Cope, Leidy, and Les- quereux; and of Canada under Sir William H. Logan, F.R.S., by Billings, Dawson, and Hall. Since the year 1862, through Scudder, we have our first know- ledge of the insect-life of the Devonian period ; through Leidy, Cope, and Marsh we have seen the meagre list of American Creta- ceous reptiles enlarged, until it exceeds that from all the world besides; and through the same geologists, not only has the mam- malian fauna of the American Miocene received additions of many species, but the stranger fauna of the Rocky Mountain Hocene has been first made known. Through Marsh, also, the first American Cretaceous birds have been named, and the announcement has come Reviews—Delesse’s Revue de Geologie. 45 of a bird with teeth in sockets, like some of the higher reptiles. In addition to these we must not omit to record the labours of Newberry among the Fossil Fishes; of Hall, Meek, Billings, among the In- vertebrates ; of Lesquereux and Dawson among the Fossil Plants. Nor have the labours and publications of Huropean geologists and paleontologists been overlooked or ignored by the author. Such are briefly the vast mass of additional geological and pale- ontological materials, the essence of which Professor Dana has laboured to incorporate in the New Edition of his most excellent text-book. The volume was originally so large (798 pp. royal 8vo.), that it could hardly, consistently, have been made more bulky, yet thirty additional pages have been added to the new edition, and the author tells us ‘‘the work has been, for the most part, rewritten.” If we were to take exception to anything in the book before us, it would be the weight (3 lbs.), which is very tiring to the wrists. We are disposed, on this account, to advocate the division into 2 vols. for all books weighing over 1# Ibs. Asasuggestion for a future edition, we would ask that a couple of pages of text should be placed at the end of the volume, immediately next to, and in explanation of, the physiographical (folding) chart of the world. ‘This could very well be done without increasing the bulk of the volume, as three blank leaves (= 6 pages) are inserted at the end of the book. We hardly think the “ Pre-historic Man from the Cave of Mentone,” (See Grou. Mac. 1872, Vol. IX. pp. 272 and 368), which forms the frontispiece to the New Hdition of Prof..Dana’s work, is of sufficient antiquity to merit so much importance. There is always an element of error to be allowed for in correlating the human remains in caverns with those Rhinoceros, Ursus speleus, and other Mammalia now extinct in Hurope. The illustrations throughout the book are most excellent, but they are chiefly selected from American types. We heartily recommend this New Hdition of Dana’s Manual of Geology to the notice of our readers. IJ.—Revve DE Geonociz, PAR MM. Detessz et De Laprparent. (Paris, 1874.) HE Revue de Geologie, which is reprinted from the Annales des Mines (tome iv. 1875), forms the eleventh volume of the Records of Geological Research prepared by MM. Delesse and De Lapparent, and contains notices and abstracts of various papers published in different countries during the years 1871-72. It is compiled with the same care as the previous volumes, and, inde- pendently of the resumé of the memoirs noticed, is a useful addition to geological literature. 'The matter is arranged under five different heads :—general, lithological, historical, geographical, and dynam- ical geology. The lithological section is fully treated, and contains the more recent observations on the composition, structure, and classification of rocks. J. M. 46 Reports and-Proceedings— I= ap OusyalS) ANAND) aS tEY(O\O Ia IDADN (GS SS GroLocicaL Scormty or Lonpon.—November 18, 1874. — John Evans, Esq., F.R.S., President, in the Chair. 1. “On Fossil Evidences of a Sirenian Mammal (Hotherium Afgyp- tiacum, Ow.) from the Nummulitic Eocene of the Mokattam Cliffs, near Cairo.” By Prof. Owen, F.R.S., F.G.S., ete. The specimens described in this paper were obtained by Dr. Grant, of Cairo, in a block of the white limestone of the Cerithian Nummu- litic zone, quarried extensively for building purposes in the Mokattam Cliffs. They consisted of a few fragments of the base of the cranium and a cast of the entire brain with the commencement of the myelon. The author discussed the characters presented by these remains, which he regarded as having belonged to an extinct Sirenian, pro- bably allied to Halitherium, which he proposed to name Hotherium Aigyptiacum. The characters of the brain, as deducible from the cast, were detailed, and shown to be Sirenian. By comparison with the brains of other Sirenia, the author was led to trace a progress in the cerebral characters of the animals of this type, from its first known appearance in the Nummulitic formation of Egypt to the present day. He also inferred, from its presence in the Nummulitic limestone, that this rock had been deposited not far from a shore. Discuss1on.—The President expressed the pleasure with which he had listened to Professor Owen’s exhaustive paper, and said that he thought that the final remarks were of very great interest as indicating that there were probably causes for changes of form. The latest species, although perhaps the most highly organ- ized, did not appear to be the most ‘‘long-headed.” Dr. Murie explained the distinctive characters of the four genera of Sirenian Mammals, Manatus, Rhytina, Halicore, and Halitherium, and stated that he re- garded Halitherium as the highest form, seeing that it was a four-limbed type. He remarked that in the young AZanatus the brain differs in form from that of the adult, which was a fact to be considered with reference to the data on which Prof. Owen’s deductions were founded. Mr. Seeley said that he had no doubt the brain was Sirenian, and indicative of a new genus. The existing genera differed from it, in his opinion, in having the Sirenian characters more strongly marked rather than in showing a higher cerebral type. In general form the brain reminded him rather of a Carnivore than of a Sirenian; and he thought it indicated affinity with a generalized Carnivorous type more than with the living Sirenians. Mr. Bauerman stated that the section from which this fossil was obtained is about 600 feet high, but the quarries referred to by the author were within about 100 feet of the top, in what had been regarded by Dr. Le Neve Foster and himself as a shallow-water deposit. The lower parts of the Cliff are very like the Chalk with flints, except that they contain Nummulites. Mr. Charlesworth remarked that the fossil now before the Society was exceed- ingly interesting, as indicating the extension downwards in time of the Sirenian type. He stated that he did not believe that the English Halztherium Canhame was of Miocene age. Dr. Leith Adams said that the Maltese Halitherium was truly Miocene. Prof. Owen briefly replied, and concluded by hoping that the objections to any of his conclusions, if reported, would be accompanied by their grounds. Geological Society of London. 47 2. “On the Geology of North-west Lincolnshire.” By the Rev. J. H. Cross, M.A., F.G.S. The district treated of is that lying between the three rivers, Humber, Trent, and Ancholme. The Liassic and Oolitic beds were described, from the Keuper (found in the bed of the Trent) to the Cornbrash (the highest Oolitic stratum existing on this line), The existence of the Rheetic beds was held to be doubtful ; the bone-bed and the shell Avicula contorta have not been found. On the other hand, the Lower Lias has a large development; and the recently discovered Ironstones of Frodingham and Scunthorpe were shown to lie in this formation, the zone being that of Amm. semicostatus. Higher up the series the zone of Amm. margaritatus seems to be wholly wanting, and the Marlstone series has dwindled to a bed of 8 feet in thickness, locally termed the Rhynchonella-bed. The Upper Lias is represented by clays not much explored. As regards the Oolites, the “‘ Lincolnshire Oolite” is the prevailing rock; but a lower band, called “‘Santon Oolite,” was distinguished from it, containing a different fauna. Above the Lincolnshire Oolite a greenish clay, capped by Cornbrash, represents the great Oolite formation ; and beyond this the alluvium of the Ancholme valley covers everything, till the Chalk rubble and the Chalk wold rise above it to the eastward. Discussion.—Mr. Etheridge spoke as to the excellence of the paper, which contained a most useful collection of facts. Two of the species of Ammonites exhibited were rare, being new to Britain, and only previously known in France and Germany, showing and confirming the wide distribution in space of certain forms of this group. An important feature in Mr. Cross’s paper consisted in his determining and ‘correlating the zones of life in his area with those of the south and ~ west of England, especially as regards the lowest part of the Lower Lias. The fixing the true position of the Frodingham ironstone and its associated Fauna, fully establishing its place, thickness, and value, and finally settling the point at issue as to its being on the same horizon as the ‘‘ Cleveland seam,” is also of high importance. Mr. Judd remarked on the interest attaching to this communication, not only as describing a district but little known to Geologists, but also as furnishing us with evidence of very fine developments of geological horizons which, elsewhere in this country, are represented only in a very imperfect manner, or not at all. My. J. F. Blake remarked that though the author had found no exposure of beds between the Angz/atus-zone and the Keuper, they probably existed, as they occurred both to the south and to the north in Yorkshire, across the Humber. He agreed with the author that the ironstone of Lincolnshire was on an entirely different level, and was totally unrelated to that of Yorkshire, the true equivalent of which, though here only eight feet, was much thicker, though not valuable, across the Humber. ‘The Pecten-beds mentioned were characteristic of the same zone in Yorkshire as in Lincolnshire ; but in the former county they contained no iron except in the form of pyrites. The thinness of the upper beds, as contrasted with the thickness of the lower, showed a veritable thinning out of them, which was continued into Yorkshire, where some of the fossiliferous bands of the Inferior Oolite described by the author appear to be altogether wanting. Prof. Hughes said that he thought we should be careful not to infer too hastily an interruption in the continuity of deposition from the absence of certain fossils from the horizon at which they occur in other sections. 48 Correspondence. COS = @ANy sa SN Caza. = DEEP-BORING IN PRUSSIA, Ere. Str,—It may interest some of the readers of the GEronoGIcaL Magazine to learn that a boring has lately been carried out by the German Government at Sperenberg, twenty-five miles south of Berlin, which has reached the surprising depth of 4040 feet! and — is the deepest boring in the world (not even excepting America) ! It is almost all through the Saliferous Rocks, Triassic series (Keuper, Muschelkalk, and Bunter), and was finished in 1872. The boring is done with rods, but the details I have not yet learned. The following Extract from a letter, 19th Nov., 1874, from Thos. J. Bewick, Civil and Mining Engineer, to Major Beaumont, M.P., Managing Director, Diamond Rock-Boring Company, Limited, 2, Westminster Chambers, London, may prove of interest, as showing what can be done by means of Diamond Boring. “ BouemiAN Broap-Bore-Hote. « Actual boring was commenced on the 15th July last. On 8th inst. the depth was 1931 Vienna feet, equal 2001 4’ English feet. At commencement bored 35 feet, when stopped by fall of ground. 13’ more, equal to 48’, lined with 5 inch tubes, and then bored up to 96 feet with 4 inch crown. Lost water by a cleft at 73 feet. Bored to 180 feet with 4 inch crown. Again lost water from tubes not being close to the bottom. Withdrew 96 feet of tubes, and widened the whole to 180 feet with 5 inch crown. Lined with 5 inch tubes to that depth, and continued with 8 imch crown to bottom. No more tubes required after 180 feet. Usual recent rate of boring 30 to 40 feet per day of 24 hours (2 shifts of 12 hours each). Boring is in New Red Sandstone formation. Conglomerate occurred from 520 to 580 feet, 680 to 850 feet, and 1200 to 1510 feet, equal to 540 feet in all. The pebbles were firm, with but few loose stones. ~ The Conglomerate consists of porphyry, Silurian shales, granite, and quartz. The rest of the strata are the usual Sandstones, Shales, and Marls in the New Red Sandstone formation.” I can only hope the Sub-Wealden Exploration may succeed in attaining as great a depth as that of Sperenberg, near Berlin.—J. P. _ ENGLAND AND FRANCE IN THE GLACIAL EPOCH. Srr,—In a clever and able article by Mr. Thomas Belt, F.G.S., published in the “Quarterly Journal of Science” for October last, that gentleman advocates the theory of a great river flowing south- wards, towards the close of the Glacial epoch, down what is now the English Channel, and embracing the Rhine, the Thames, the Seine, and other rivers in its course. This is, I believe, contrary to the generally received notion that the Straits of Dover had not then been cut, and that the Thames flowed northwards to join the Rhine. Perhaps Professor Prestwich or some other of your Quaternary Geological readers will relieve my mind by telling me which is the right faith. J. SUSSEX. See Cuan Ss in aE ES en eeTg iy uae ch a ne. Geol. Mas6.i875. NEW SERIES. Decade ll Vol I PV Ti yilace el. WV. West & Co.ump. et Lith, Aporrhai de, Recent (Fig1d.) & Fosstl (Figs 1-14) THE GEOLOGICAL MAGAZINE. NEW SERIES. DECADE II. VOL. Il. No. IL—FEBRUARY, 1875. ORIGINAL ARTICLIES. ——— I.—On tHE GAvULT APORRHAIDZ. By J. Starkre Garpner, F.G.S. (PLATE III.) N this paper I purpose giving a history and description of the Cretaceous group of Aporrhais, as far as they are at present known to me, especially of those forms which are so beautifully preserved in the Gault of Folkestone, and so-called Upper Green- sand of Blackdown. I regret that I cannot include the Aptien and Neocomien species, but the collections at present open to me are too meagre to give anything like a complete account of them. In the whole group there are even now many points which require further research ; the correlation of some of the forms with those on the Continent is still unsatisfactory, from the difficulty experienced in comparing actual specimens. The figures available, even in the most modern works, appear in some cases to have been restored, and not therefore to represent the form of any shell that has been really met with. As a result of my examination, I think it very probable that all or most of the British Cretaceous fossil forms are met with in similar deposits abroad; but this uncertainty in figuring, and the practice of describing new species from single and generally imper- fect specimens, has prevented me from placing similar, and what appear closely allied forms under the same specific names. I believe the list appended from the Gault at Folkestone to be a complete one, so far as the forms are at present known, as it is based on an examination of many hundreds of specimens. As regards the Blackdown list, I find I cannot confirm the statements of the occurrence of many species mentioned by other writers. I have seen and examined the collections of the British Museum, Geological Museum, Geological Society’s Museum, and many private cabinets, with this view, but unsuccessfully. I have also reason to believe that many undescribed species exist from the Upper Green- sand, Chloritic-marl, and Chalk, in cabinets which I have not yet seen, and I shall be obliged to any one who would inform me of them. Forbes and Hanley, in the British Mollusca, vol. ili., in 18538, first included Aporrhais with the Cerithiade. They considered them to constitute a group intermediate between the holostomatous and siphonostomatous Pectinibranchiata, and to be closely allied to Turritellide on one hand, and Scalarid@ on the other ; they also state DECADE II.—YOL. II.—NO. II, 4 50 J. Starkie Gardner—On the Gault Aporrhaide. that the relationship to Scalaria is better seen and traced through Aporrhais in fossil than in living examples of the family: some fossils of the last-named genus, as will be seen, approach very closely to Scalaria. Gwyn Jeffreys, in his British Conchology, 1857, describes the Aporrhaide as follows :— “ Body spiral; mantle large and loose, forming a very short branchial fold at the partially channelled base of the shell, which it lines ; snout cylindrical, contractile, notched in front ; tentacles awl- shaped, separate ; eyes on bulgings or short stalks, at the outer base of the tentacles; foot small, lanceolate; gills arranged in a single narrow plume; odontophore enveloped in a sheath, straight; rachis single; pleuree or uncini three, plain-edged.” “ Shell, when young, spindle-shaped, never umbilicate; spire turreted and tapering ; mouth widely expanding ; operculum small, horny, pear-shaped, increasing by semielliptical layers; nucleus nearly terminal at the base of the mouth.” i The animal differs from those of Rostellaria, Strombus, and Péero- ceras, in the eyes being at the base, and not at the extremity of the tentacles, and in the tentacles not being bifurcate, etc. Models of both may be seen in the British Museum. Its mode of growth is similar to that of the Strombide. When young it developes in the form of a cone or spindle, and increases in the usual manner of spiral shells: but at a certain point it ceases to grow spirally; a rib of enamel appears along the mouth, the borders of which thicken and contract ; the lip dilates, expands, and becomes cut up into spikes or digitations till the outer lip is complete, when the subse- quent growth takes place by adding fresh layers inside. In the young state it extremely resembles Cercthiwm and Scalaria, a fact noticed by Swainson ; when the canal is developed, and before the wing begins to grow, its appearance is that of a Fusus. Monstrosities are not uncommon, both in recent and fossil forms, in the shape and size of the pterygoid process. The term Aporrhais was applied by Aristotle to probably what is now known as A. pes-pelicani of the Mediterranean and British seas, and was derived from the word ‘Azroppéw “to flow out,” and was on his own testimony suggested by the spouted form of the shell; he also noticed the operculum (é7iuxdAvpya or Tapa). Aldrovandus and then Gualterius used the term for Lamarck’s genus Pieroceras. Petiver in 1711 restricted the term to shells of the present family of Aporrhaide. Da Costa in 1778 adopted it as a generic appellation, but included it with Strombus, Pteroceras, ete., in Lamarck’s family of Alata. The term Chenopus was needlessly introduced by Philippi in 1886, who, however, first rightly defined and understood the characters of the genus, and has been frequently used since. I have referred somewhat at length to the history and characters of the recent family, as it is not separated from the Strombide by most conchologists; and undoubted Aporrhaides are still sometimes described as Rostellarias by geologists. J. Starkie Gardner—On the Gault Aporrhaide. ol Morris and Lycett, in the Mollusca of the Great Oolite (Pal. Soc.), instituted a genus Alaria to receive those Jurassic forms which have no posterior canal, with the left lip thin, never thickened ; left lip not, right lip sometimes, extended on penultimate whorl. Many Cretaceous forms, however, have a rudimentary canal, which would make it embarrassing to adopt the character as generic, and would cause nearly identical species to be separated, and thus break up natural groups. M. Piette distinguishes. Alaria by the wing being applied to the last whorl but one, and never adhering to the rest of the spire. This character is not of the slightest generic importance in a shell so subject to variation; in recent species the pterygoid process is sometimes attached to the second whorl, sometimes quite to the apex of the spire. See Pl. III. Fig, 15, A. pes-carbonis, recent. Mr. R.. Tate, in a paper in the Geol. and Nat. Hist. Repertory, 1865, established a sub-genus Perissoptera, with 4. occidentalis as its type, to receive those species which have a nearly entire and broad wing, prolonged into a recurved point, and attached to the last whorl but one. This sub-genus has not been recognized by zoologists in the case of A. occidentalis, and Mr. R. Tate included A. marginata, which certainly is nearer A. pes-pelicani. A simple division into groups will for the present meet all he seeks to establish. Aporrhaide appear first in the Jurassic age, and reached their greatest development in the Cretaceous seas; the number of species in this genus far exceeds that of any other Gasteropod at Folke- stone, and individuals are so numerous that hundreds of casts may he picked up in a few hours by the collector. The family decreased in importance in Tertiary times, and are now, in common with many other Cretaceous families, only represented by a few species. There appear to be only three species known, yet they are types of the largest Cretaceous group. The following may be taken as the characters of Aporrhais of Da Costa. Shell turreted, strong, moderately elongated; canal at base beak-like and shallow, never very long, differing in this respect from most Cretaceous forms; whorls numerous, variously ornamented with nodules or striz; mouth angulated, outer lip expanded and thickened, detached from the spire at upper part (not a constant character), either simple or expanded into claw-like digitations, corresponding to well-marked keels on the last whorl. With regard to the so-called British Cretaceous Pterocerata, I have long felt that they were unnecessarily separated from the family of Aporrhaide, with which they are constantly found associated, and with which I have always considered they have the greatest affinities. The principal difference is in the length of the spire, the general plan and ornamentation of the shell being similar. The attach- ment of the posterior digit to the spire, which has chiefly led to their being classed with Pterocera, is no longer a character by which they can be separated, as the figure (Pl. III. Fig. 15) of a specimen of A. pes-carbonis in the British Museum clearly shows. This figure is very similar in arrangement of the digits, canal, and ornamen- tation, to the fossil shown in Fig. 2. On the other hand, the aspect 52 «J. Starkie Gardner—On the Gault Aporrhaide. of the fossil, which may be taken as a type of our so-called Péerocera, is most unlike that of the recent Pterocerata: the lip is less dilated and thickened, the columella and aperture are not ridged, and the digitations are not so variable ; the whole shell is much smaller and more delicate. The recent Péerocerata appear to be a modern group, and to be in part the representatives of the Aporrhaide of Cretaceous times. Some of the figures given by D’Orbigny of Continental forms approach, however, more nearly to recent types. The British Cretaceous Aporrhaide may be divided, by the forms of the wing and their ornamentation into four groups, as follows: Group 1.—Spire short, ovate, longitudinally striated, carinated, lip furnished with three to four long flexuous recurved digitations ; anterior canal resembling digits in form. Type :—Avorruais RETUSA, J. Sby. Plate III. Figs. 1-6. Rostellaria retusa, J. Sby., i836. bicartnata, Desh., 1842. , D’Orb., 1842. ——— retusa (Forbes), 1845. Sow. sp. | Harpago retusus (Gabb), 1861. Sow. sp. Description.—Shell of a delicate shape, broad and ovate; the spire short, forming an angle of 874°; whorls six, inflated, convex, of which the last is equal in depth to the other five; each with two keels, the anterior being hidden by the suture, so that the last whorl alone is seen to be bicarinate, the other whorls seeming to have a single prominent ridge at or about the middle. The chief keels are elevated, narrow and subacute, the spaces between them are ornamented by spiral striz, which are extremely variable in number. On the last whorl, from two to seven or eight thread-like lines occupy the space between the posterior keel and the suture, one to three or perhaps four between the keels, and from six to twelve between the anterior keel and the canal; these last some- times extend over the canal and the dilatation which unites it with the anterior digit. ‘The spire is seen by aid of lens to be finely ribbed, the riblets being more distinct in crossing the keels: from the third whorl to the apex the keel is often undistinguishable, and the riblets so distinct as to cause a reticulated appearance. The ventral side of the shell is encrusted to the summit with a smooth polished enamel, to which encrustation is due the gibbosity of the last whorl. Each of the two keels is the basis of a very long flexuous digitated _ process, which is acutely triangular above, and deeply canaliculated ventrally; the anterior digit being very thick for half its length, . where there occurs a dilated node, which is flattened and triangular on its under-side; from this point the digitation tapers to, and is finely pointed at its termination. A third, the uppermost process, prolongs and terminates the mouth into a canal posteriorly, and is recurved backward over the spire, extending far beyond it. The anterior canal is very long and slender, being recurved rather abruptly backwards at about two-thirds of its length. ‘The lip in some adult forms (probably very old individuals) is excessively SYNONYMS... 8 Pteroceras J. Starkie Gardner—On the Gault Aporrhaide. 53 dilated, forming a palmate expansion, uniting the digits for part of their length (see Fig. 3). The mouth is narrow, oblique and oblong. The spire measures without canal -016; canal alone :025; digits "080. Distribution.—This is a most widely distributed form, being found abundantly at Folkestone, Lyme Regis, and at Cambridge,’ Black- down and Devizes, Ringmer,? etc. I have seen no specimens except from Folkestone and Lyme Regis. The same, or an allied form, is found in the Aptien beds of Folkestone. Morris gives it from Ather- field, but this is no doubt an error. On the Continent it has been found throughout the Paris basin, Doube, Varennes, Ervy, Saxonnet, Perte-du-Rh6ne, Sainte-Croix, but I have not seen it described from Aachen in German works. History.—First described in 1836 as Rostellaria retusa by J. Sowerby, in Fitton, Geol. Soc. Trans., vol. iv. p. 344, pl. 18, fig. 22. I cannot find the type or any specimen from Blackdown, and there 18 a doubt whether the same species is intended. Sowerby says, ‘It has only one elongated narrow branch to the lip. The surface between the striz is particularly smooth.” Should the Blackdown form prove distinct, Deshayes’ name of bicarinata must be adopted for it. Leymerie, in 1842, in the Mém. Soe. Géol., figured a young spe- cimen as R. bicarinata, and noticed the more delicate ornamentation, “spire delicately ‘quadrillée’ by the intersection of fine transverse ribs and of slightly oblique longitudinal striz.” In the same year D’Orbigny fignred this species in his Pal. Fr. Terr. Crét., vol. 11. p- 807, pl. 208, figs. 3 and 5, from the Albien of Aube and Ardennes, but in an unsatisfactory manner. He observes, ‘“‘ Young or old, it is clearly characterized from all other forms by its singular shape.” In 1845 Forbes mentions it im the Quarterly Journal. In 1849 Pictet and Roux figured and described this shell in the Moll. foss. Grés-verts, p. 263, pl. 25, fig. 11, but did not consider it identical with that in Fitton’s memoir. Geinitz, in his Quader-sandstein- gebirge, also figures this shell as Strombus (Pterocera) bicarinata, t. ix. fig. 4. The three names in D’Orbigny’s Prodrome are probably synonyms for this one species. In 1854 Professor J. Morris, in his catalogue, considers it distinct from P. retusa of Blackdown. The same year Cotteau, and in 1858 Leymerie, mention it from the Yonne.- In 1859 Dr. Chenu figured P. bicarinata in the Man, Conch., p. 260. It occurs in Gabb’s list of 1861, pp. 56, 71, under Klein’s name of Harpago (1753). In 1864 Pictet and Cam- piche and Pictet and Roux described it. The figures in Pictet and Campiche, pl. xci. figs. 5 to 8, differ, however, from our British form, except fig. 5; perhaps owing to their being figured from imperfect specimens. In 1865 Briart and Cornet, Descr. Min. de la Meule de Bracquegnies, p. 17, pl. 2, fig. 3, figure a specimen with dilated lip as P. macrostoma, Sow., a species it in no way resembles, and also figure P. retusa, but with a different form of wing. In the same year Mr. R. Tate described P. retusa, but separated it from 1 Seeley. 2 Fitton, Morris, etc. 54 J. Starkie Gardner—On the Gault Aporrhaida. P. bicarinata, which he says he had never seen, but giving them both from the Gault of Folkestone, where certainly only one species is found. Mr. Tate describes P. bicarinata as follows :—*“ Possesses two keels, each corresponding to a long digitation, an anterior canal, and a posterior expansion towards the spire.” This description applies equally to A. retusa, in fact the two names are synomyms for the same species. In 1869 Jaccard cites it from the Lower Gault of Ste.-Croix. Other species belonging to this group. P. Moreausiana, D’Orb. Lower Greensand. P. Fittom, Forbes. Probably synonymous with above. Lower Greensand. P. globulata, Seeley, 1861, Greensand, Cambridge, appears to differ only in size. A. bicornis, P. and C., from the Upper Gault, very closely resembles . retusa, but seems to have had a rather longer spire. P. macrostoma, Briart and Cornet, is a similar form with diated lip; quite distinct from the R. macrostoma, Sow. fi. ovata, Minster, Green Chalk of Haldem, bears considerable resemblance in form, but the figure in Goldfuss, Petr. Germ., shows a pointed spine in the middle of second whorl, as in Oolitic A. spinigera. Chenopus Coulont, de Loriol, 1861. No keels, except two on body- whorl, spire longer than P. Moreausiana. Neocomien of Mont- Saléve. Two undescribed species from the Grey Chalk of Dover. Group 2.—Shell pupeform, with keels prolonged in two very long narrow flexuous digits, anterior canal long and resembling the digits. Type:—APORRHAIS CINGULATA, Pictet ee Roux. PI. III. Figs. 7-10. Description—Shell elongated and pupeform, composed of about eight convex inflated whorls, the last of which is smaller than is required to form a regular cone, being but one-sixth more in diameter than the preceding whorl. Whorls with four simple longi- tudinal salient but rounded keels, without trace of tubercles. On all but the last, the two median keels are equally prominent ; of the other two, the anterior is very small, and is nearly concealed by the suture; the posterior is more or less subordinate to the two median keels, and is situated midway between them and the suture, its relative prominence being very variable. On the last whorl the posterior median keel is much more pronounced than the other, and is prolonged into an exceedingly long narrow flexuous digit, which is convoluted, taking a half turn near the lip, and then curving gradually upwards, attaining a length exceeding twice thatof the spire. The process is grooved underneath. The anterior keel forms another downward spiked digit not convoluted, and of less length. The anterior canal is about one and a half times the length of the spire, is flexuous, and generally abruptly recurved, or bent backwards at J. Starkie Gardner—On the Gault Aporrhaide. 55 nearly a right angle to the axis of the spire. The aperture is oblique and pyriform. The lower portion of the last whorl may sometimes be longitudinally ribbed ; on the first whorls the posterior median keel predominates more or less to the exclusion of the others. The shell without canal measures ‘033, the canal :045, wing process "045, middle digit :024. Distribution.—This is a very characteristic, and I should think will prove a widely distributed, though rather rare shell. It is found in the Lower Gault at Folkestone, and in Switzerland, at Sainte-Croix, the Perte-du-Rhéne, and also in France, at Dieuville, Colombiéres. It cannot be confounded with any other species. History.—Pictet and Roux first described this species in 1849 in the Moll. foss. Grés-verts, p. 261, pl. 25, fig. 7, from the Gault of the Perte-du-Rhéne. Their specimens were all casts. D’Orbigny in- cluded it in his Prodrome, and Pictet and Renevier found it, 1854, in the Gault of the Perte-du-Rhone. Pictet and Campiche in 1864, pl. 94, figs. 10 and 11, p. 617, figure a specimen from Folkestone, and casts from Sainte-Croix. In 1865 Tate described it in the Geol. Repert. p. 96, fig. 16; and in 1869 Jaccard mentions it from Sainte-Croix. Type:—AporRHAIs GRIFFITHS, Gardner. PI. III. Figs. 11-14. Description.—Shell elongated and pupeform, composed of eight very convex whorls, the last having a less diameter than is required to form a regular cone. The whorls have a central, salient, angular keel, and a second anterior keel conceals the suture ; there is also a third and faintly marked keel anterior to the predominant one and midway between it and the suture. The keels are not visible in the first two or three whorls, but develope as they increase in size, all three keels being visible on the last and penultimate whorl. The whorls, except the last two, are ornamented with fine, transverse, oblique, acute, and angular ribs, wide apart, eight or nine on each whorl, which interrupt the median keel in crossing and form nodose tuber- cles. This ornamentation is most distinctly seen near the apex, where the keels are obsolete, and becomes less so in descending the spire. The last whorl is smoothly striated, having the three keels pronounced. The principal keel is prolonged into a narrow acutely angular process at right angles to the axis, till near its termination, where it curves gradually upwards, terminating in a fine point. A straight downward spike seems to correspond with the second keel. The anterior canal is longer than the spire, and is recurved abruptly to the left, as in A. cingulata. The aperture is narrow and angular, without encrustation. In form this species bears a striking similarity to A. cingulata, with which I have grouped it; but the ornamentation is of a dif- ferent character and the shell is much smaller. Its sculpture strongly resembles that of R. tricostata, D’Orb., Pal. Fr., pl. 207, fig. 5, p. 287, from the Gault of Ervy, where it is rare, and A. triboleti, P. and C., from the Lower Aptien of Sainte-Croix. The keels are, however, in these latter strongly marked near the apex, and the 56 J. W. Judd—On Volcanos. ribs are nearly obsolete. The form of their spires is also not pupeform. The shell measures without canal 017, canal only -022. Distribution.—Gault of Folkestone, where it is rare. I should perhaps have named this A. pupeformis, and have thereby implied the form and character of the shell ; but this name was appropriated by D’Archiac in 1847 for a little-known Oolitic species. I have named it in compliment to John Griffiths, the well- known collector at Folkestone, who has furnished me with the great majority of my specimens. A comparison of specimens in cabinets supplied by him with figures of Folkestone fossils of twenty or thirty years ago, shows the useful, and let us hope not unprofitable, work he has devoted himself to. EXPLANATION OF PLATE III. Fia. 1.—Aporrhais retusa, J. Sby. Natural size, showing ventral side. The posterior digit is slightly lengthened from a specimen lent me by Mr. Price. Fic. 2.—Showing dorsal side. Fig. 3.—Specimen showing dilated lip. Fic. 4.—Part of a shell, to show dilated node. Enlarged. Fic. 5.—A young shell, to show mode of growth. Fie. 6.—A young shell, illustrating the same, from the British Museum. Fic. 7.—Ayporrhais cingulata, Pictet and Roux, showing arrangement and relative position of digits and canal. Fie. 8.—Specimen showing development of wing. Fie. 9.—Another, with dorsal view. Fie. 10.—Specimen showing aperture and middle digit. By tracing and reversing Fig. 7 and Fig. 8 an illustration can be obtained of the relative length and position of the wing and canal, showing general appearance of the shell. Figs. 11 to 14.—Aporrhais Grifithsit, Gardner, from Folkestone. All in the author’s cabinet, save Fig. 6. Fic. 15.— Aporrhais pes-carbonis, Recent. (To be continued.) IJ.—ContRIBUTIONS TO THE Stupy oF VOLCANOS. By J. W. Jupp, F.G.S. (Continued from page 16.) Tue Lipari Isxanps (continued). 3. Third Period of Volcanic Activity in the Lipari Islands. Although, as we have already seen, the older volcanic formations of the Liparis present us with features of no little interest, yet it is on account of the cones and lava-streams, composed of rocks of singular beauty and almost unique character,—which are the product of the latest developments of igneous action in these islands, that the attention of geologists is most frequently directed to them. Lofty cinder-cones, composed of snowy pumice, their vast craters breached by lava-streams of solid glass, seemingly fresh as when the fiery flood leaped from the volcano’s throat, and poured with slow and tortuous current down its flanks; wide-spreading lava- fields, their horrid bristling surfaces coated by a reddish-brown crust, but exposing in grand cliff-sections the most marvellous com- binations of variegated rocks ;—these seen rising amidst the bright blue waters of the Mediterranean, and displayed in that clearness of J. W. Judd—On Volcanos. 57 outline and that vividness of colouring which only the brilliancy of an almost tropical sky can impart, constitute scenery of startling novelty and wondrous beauty—the impressions produced by which it is as hopeless to convey as it is impossible to forget. Nor is the geologist disappointed by a nearer approach to these remarkable scenes ; every blow of his hammer revealing fresh examples of singular rock- structure, novel groupings of crystallized minerals, and lively illus- trations of the multiform products which result from the action on rock-masses of the ever-varying combinations of many forces,—such as heat, chemical affinity, crystallization, pressure, tension, and the disengagement of imprisoned vapour and gas. But before entering on a description of some of these remarkably interesting volcanic cones and lava-streams, composed of pumice and glass respectively, it will be well to pause in order to notice the very striking linear arrangement affected by the volcanic vents belonging to both the second and the third periods of igneous action in these islands. For nowhere, perhaps, is this constant feature of the de- velopment of volcanic forces—so unmistakably suggestive of the existence of subterranean fissures—more admirably and clearly illustrated than in the Lipari Islands. Commencing with the southern part of the Island of Vulcano (see map, p. 7), the observer, standing on the summit of the Monte Saraceno, will have no difficulty in perceiving that there lie before him the remains of at least four different volcanic cones and craters, which have been successively formed through the continued shifting of the eruptive vent to more northerly positions. The great central cone of Vulcano, with its magnificent active crater, is evidently thrown up on a continuation of the same line. But an attentive study of this cone and crater-ring clearly indicates to the geologist that they are not the product of a stationary vent; on the contrary, we find clear evidence that the cone has been more than once partially destroyed by explosion and its crater re-formed. Indeed, portions of at least three successive crater-rings, which must have been clearly excentric with one another, can be easily traced. It is interesting to notice that the last eruption of this volcano (which, as will be described in a future chapter, took place only a year ago) threw up cinder-cones at the bottom of its great crater, not, however, at its centre, but at its extreme northern limit. Again, we have proofs of the opening of a vent, still a little farther to the north, in the actual walls of the great cone, in the beautiful little crater called the Fossa Antico. The Faraglione, situated between Vulcano and Vulcanello, is a mass of volcanic agglomerates, in which mineral deposits of great beauty and value have been developed, in consequence of the permeation of the mass by acid gases and vapours; it is now burrowed over, like a rabbit warren, by the excavations which serve as houses for the workmen employed in the chemical works in the adjoining great crater; this mass of tuffs is clearly the greatly denuded and ruined vestige of a cinder- cone. Thus we find that in the island of Vulcano there exists evidence of the opening, along a single line, of at least nine different 58 J. W. Judd—On Volcanos. vents, which have given rise. to eruptions differing very greatly in violence and duration. . On a continuation of the same line, we find in Vulcanello, now joined to Vulcano by a bank of cinders, three other well-marked craters. The features presented by Vulcanello are illustrated in the accompanying sketch (Fig. 6). Of these craters the newest is 6 Fic. 6.—Vulcanello with its three craters as seen from the south end of the Island of Lipari’ a. Most modern crater. 6. Central, largest, and oldest crater. c. Portion of third crater. d. Section of cone in sea-cliff. e. Lava-stream. clearly that which occupies the most southern position, and which was in all probability due to an eruption during the historical period. The most northern of the three craters of Vulcanello has had one- half of its periphery removed by the encroachments of the sea, and here we actually find a clear section of one of these small volcanic cones, as represented in Fig. 7. The central crater of Vulcanello is the largest, most ruined, and probably the oldest of the three. OV Fie. 7.—Section of cone of Vulcanello in sea-cliff (d in Fig. 6). a. Crater. 6, b. Lava- streams. c. Dykes which have clearly formed the ducts through which lava has risen to the crater. d, d. Stratified volcanic tuffs and agglomerates, exhibiting the characteristic arrange- zee of the interior of voleanic cones. e. Portions of cliff concealed by taluses of fallen frag: ments J. W. Judd—On Volcanos. 59 - The island of Lipari must be looked upon as only accidentally separated from that of Vulcano and Vulcanello; the same line of volcanic cones and craters which we have described in the latter being clearly continued in the former. In the southern part of the island of Lipari we find at Punta Capparo, Formiche, Monte della Guardia, and Fossa del Monte, weathered and unmistakable craters and lava-streams, composed of materials of highly acid or siliceous character, namely, pumice and quartz-trachyte (Liparite), passing into obsidian, perlite, retinite, etc., and evidently belonging to the latest period of volcanic eruption, The central parts of the island of Lipari are entirely composed of the tuffs and lavas of the second period; these are, however, as we have already seen, much altered by the gaseous emanations, still represented by the hot mineral springs of San Calogero and the stufe of Bagno Secco, which must be assigned to the third period. The great central crater of Monte Sant’ Angelo (see Fig. 38, page 14) is thrown up on the same great line of fissure which we have been tracing to the southwards; but on the west and east sides of it respectively we find the smaller lateral craters of Mazza Carus and Monte Perrara or Forgia Vecchia, the latter belonging to the latest period of eruption. The northern part of the island of Lipari, like its southern ex- tremity, exhibits a fine series of pumice cinder-cones and lava- streams of volcanic glass graduating into Liparite, evidently of recent origin, and forming a continuation of the same north and south line of vents. ‘These we shall presently describe in greater detail. Thus we have clear evidence that along a line, directed towards the earliest and great central volcano of the Lipari group, at least twenty distinct vents, giving rise to volcanic cones and craters of varying size, have been formed. It seems probable, as suggested by Hoffmann, that the volcanic products of Capo di Milazzo may be regarded as a continuation of the same line. The twin voleanos of Salina (the Didyma of the ancients) with those of Filicudi and Alicudi are evidently situated on another line, which may perhaps be produced to Ustica. ‘This line also radiates from the same central volcanic mountain. Lastly, in Stromboli, with its linear arrangement of old and recent craters, and in Stromboluzzo, doubtless the last relic of another volcanic pile, we see evidence of a third string of volcanic vents, the direction of which points to the same great centre of igneous activity. That the linear arrangement of volcanos, such as we have described as so well exemplified in the Lipari Islands, points clearly to the ex- istence of great fissures in the earth’s crust, along different parts of which eruptions have successively taken place, has been recognized by all geologists. Indeed, in the fissures produced at Etna during the recent eruption (1874), as described by Professor Silvestri, of Catania, in the earlier eruptions of the same mountain in 1669, 1811, and 1819, and in many analogous cases, we have had ocular demon- stration that such is the case. Fresh proofs of the correctness of 60 J. W. Judd—On Volcanos. this conclusion are afforded by the great fissures filled with volcanic © materials, with which all geologists are familiar, as traversing older rock-masses where exposed by denudation. Nor must we forget that the voleanic band, which has been indi- cated as passing through the great central vent of the Liparis and Stromboli, would, if produced, strike the great earthquake-shaken tract of Calabria, and by a slight deflection pass through the volcanic districts of Southern and Central Italy ; while the southern continua- tion of the same, passing through Lipari, Vulcanello, and Vulcano, points to Etna, the Val di Noto, and the volcanic islands lying south of Sicily. These facts are interesting, as indicating that Von Buch’s classification of volcanos, according to their mode of arrangement, in linear systems and groups, eannot be sustained. All volcanic action appears to be developed along lines of fissure, though these may present very varied relations and connexions with one another, I shall take occasion, hereafter, to show that the principal of these combinations assumed by volcanic lines of fissure may be classified as radial and parallel series. The fissures of the Lipari group afford an interesting example of the radial arrangement, with some illustration of the production of lateral or branching fractures on either side of the principal ones. The whole, however, being probably a subordinate part of a great band of subterranean voleanic action. It is a most interesting circumstance, and one by no means devoid of suggestiveness to the geologist, that the two active volcanic vents of the Lipari Islands are situated at distant, almost indeed extreme, points of the group; and that while one of them, Stromboli, ejects materials of the most highly basic character—dolerite and basalt— the other produces rocks of extremely acid composition, quartz- trachyte (Liparite) and obsidian. The striking differences in the specific gravities of these two classes of rocks has been commented on by many geologists. As every great volcanic area may fairly be supposed to have beneath it a reservoir of materials in either an actually or potentially! liquefied state, we may, without adopting Durocher’s notions of universal acid and basic magmas, suggest a possible explanation of the peculiarities of the existing volcanic phenomena of the Lipari Islands. If we imagine the area to be underlaid by a reservoir of liquefied materials which is of inter- mediate composition, this might have supplied the products of all the earlier eruptions of the district; and it is only necessary to suppose that, by the action of gravity, the materials (magmas) of different densities were in process of time separated from one another, while distinct fissures were opened connecting the upper and lower portions of the mass, respectively, with different parts of the surface,—to see that just such phenomena as now take place would be called into play. ' By a rock in a potentially liquefied state, I of course mean one which, either from its elevated temperature or its condition of internal tension from imprisoned volatile constituents, would assume a liquid form on being relieved from the pressure which maintains it in a solid state. J. W. Judd—On Volcanos. 61 Reserving for a future occasion, when some other volcanic districts have been described, all general remarks upon the classification of the products of volcanic action, we may notice that the modern lavas of the northern fissure (Stromboli and Stromboluzzo) produce rocks of the most typical basic character, namely, basalts and dolerites. Abich’s analyses of these lavas gave the following results—their specific gravity being between 2°86 and 2-96. Lava of Stromboli. Lava of Stromboluzzo. SHINER cos cod 600, Sos too c0b.| coo UZ 53°88 J AVIIIA, osc cog co) ce | co oY) 12°04 Oxide of Iron ... .06 22.22 vee 10°58 9°25 Oxide of Manganese... ... ... ... 0°38 — JURA cos 605 e090) cop 000, 00" coo AISNE 7:96 Magnesia fee coo coo, 8°83 Soda (with some Potash) ooo cod oe 4-76 MOSS tien yh peees. ttass 2°78 The second of these poses wanes to have undergone a certain amount of alteration. These doleritic lavas appear to consist mainly of an aggregation of nearly equal proportions of crystals of Labradorite felspar and augite, to which variable quantities of magnetite and olivine are added in different examples. As is usually the case with igneous rocks of basic composition, a lavas of Stromboli only very rarely assume the vitreous condition. The scoriz which are ejected from the active crater of Stromboli, at intervals of a few minutes only, sometimes fall so near to the observer that he can approach them while still in a soft and plastic condition, and thrust coins or other hard objects into them. These cinders are found on examination to be perfectly stony in character ; but they are completely full of vesicles, formed by the escape of volatile materials from their midst, and they usually inclose nearly perfect and very beautifully formed crystals of augite—sometimes of considerable size. But besides the scoriz, showers of volcanic sand also fall around the observer standing beside the crater of Stromboli. This volcanic sand proves on examination to be, like the similar materials ejected from Mount Klut in Java in 1864, and from the volcano of Georg in the Gulf of Santorin in 1866, both of which were submitted to microscopical examination by Vogelsang, an aggregate of more or less broken and rubbed crystals of augite, felspar, olivine, and magnetite, with comminuted fragments of scorie. Around the sides of the crater of Stromboli crystals of augite can be collected in great abundance ; they are usually macled, and some- times form beautiful stellar groups and: other interesting com- binations. These are doubtless in part ejected directly from the crater, but in other cases result from the breaking up of the light cindery fragments in the midst of which they were inclosed at the time of their ejection. That these crystals were actually formed within the volcanic vent there is not the smallest room for doubt. That Stromboli has in comparatively recent times given forth streams of basaltic lava of very considerable magnitude is clear to any geologist who studies the fresh and undecomposed fields of lava 62 J. W. Judd—On Volcanos. (Sciaras) which surround the island. Sometimes this lava assumes the finely columnar structure so common in rocks of this class. Thus, a very fine series of columns is exhibited at Punta Labronzo, the northern point of Stromboli, and ruder ones at Punta del Uomo, on the south-east of the island. On the extremest verge of this latter lava-stream is situated one of those little shrines, which, in spite of the apparent inaccessibility of its position, has its burn- ing lamp constantly replenished. The voyager in these seas is startled when, on reaching these spots, the wild cries and strange songs of the boatmen are suddenly hushed, all engaging for a few moments in silent devotion to the saint who is supposed to warn, by means of this primitive and not very efficient lighthouse, the mariner who approaches these inhospitable shores. The products of the modern eruptions along the southern line of » fissure—that, namely, which extends beneath the islands of Lipari and Vulcano-—offer, as we have already remarked, the most striking contrast to those of Stromboli. These lavas belong to that highly silicated class so well illustrated in the Ponza Islands, the Huganean Hills, and Hungary. The highly acid lavas, to which the name of quartz-trachyte is usually applied, but which by Roth were called “ Liparite,” and by Richtofen “ Rhyolite,” are in their ultimate composition almost identical with the granites; and when highly crystalline, are seen to be composed of precisely the same constituent minerals—namely, several species of felspar, orthoclase being always predominant, free quartz, and variable quantities of hornblende or mica. By the peculiar arrangement of their materials, however, the highly silicated lavas are well characterized; and in their internal structure they present features which almost always serve to dis- tinguish them from the granites, with which they were by early geologists so frequently confounded. In illustration of the ultimate composition of these highly acid lavas of Lipari, we give the following analyses of Abich, with which others by Berthier and Klaproth closely agree : Obsidian of Lipari. Pumice of Lipari. Silica sea wiceen vince ah eee mince ec tees 74:05 73°70 IAM INAH e ohh, he Mecca les 12:97 12:27 Oxidexotlronysrece alesse oscil Meee 2°73 2°31 ALINE shel ciiecisnprews eeeery lasek putes) ates 0:12 0-65 Miacnesiajzss) “sce: tse assen moses lees 0:28 0:29 BOda st rdce acel veser tesell ices ites 4:15 4:52 Potash eee eces Meek fede 5°11 4-73 AWoater Piss slice gosehten S.oiihcden Ween 0:22 1:22 Chilorinees-cnene--sitesrinieronnies- mise 0°31 0°31 The specific gravity of the obsidian is 2°3702, and of the pumice 2°3771. When in its most completely stony condition, the rock has a specific gravity of 2-53, and consists almost entirely of orthoclase felspar, quartz, and hornblende, in about the following proportions : JN@ISOEN soa 000 G00, 00.008, 00000 77 per cent. Quartz) ope ha Rigen ess yi 18 ” Hornblende or Mica... ... ss. eee 5 - In the less compact or stony and more cavernous varieties of J. W. Judd—On Volcanos. 63 Liparite, the ordinary hornblende and mica crystals do not appear ; but instead of them, we find in the mass grains of magnetite with groups of acicular, filiform, or capillary crystals, which we should at first sight refer to Breislakite, but which, considering their association, may probably be regarded as a variety of hornblende, bearing the same relation to the Amphibole series which Breislakite does to the Pyroxene series. In striking contrast to the basic lavas of Stromboli, the highly acid lavas of the Lipari and Vulcano constantly tend to assume the vitreous condition; some of the lava-streams being, indeed, com- posed of solid volcanic glass. These glasses in turn frequently assume a more or less pumiceous structure, through the inflation of their materials with blisters and bubbles, as a consequence of the dis- engagement of those volatile constituents which the researches of many chemists show that obsidians so abundantly contain. ‘The cones formed of the ejected fragments of these newer volcanos of Lipari and Vulcano consist of fragments of typical pumice. So excellent and abundant is the pumice of Campo Bianco in Lipari, that it is sent to all parts of the world; and its collection, preparation by drying, and exportation, constitute one of the most important sources of wealth to the islanders. — Mingled with the white pumice, which constitutes fragments of every conceivable size, there occur numerous volcanic bombs, in which every stage of the transition from obsidian to pumice can be admirably studied. The exterior surface of these bombs is covered with a crust of solid obsidian, which is usually cracked into a number of polygonal fragments; but, as we pass towards the centre of the bomb, blisters gradually increase in number, till the centre is found to be composed of a mass as light and porous as a sponge. Bombs of this character, sometimes many feet in diameter, and which have been usually broken by their fall, are found scattered around the active cone of Vulcano, and are in all probability the product of its last grand eruption in 1786. The wonderful variety of the acid rocks of the Liparis arises from the fact that every possible gradation between the stony, vitreous, and pumiceous characters, may be observed in them. ‘The liquefied material may, according to the conditions of its consolidation, assume one of three forms, Liparite, Obsidian, or Pumice, or it may form a material in which the diverse characters of these three products are united in the most singular and unexpected combinations. Some of these remarkable and interesting varieties, which may be well studied at Rocche Rosse, Monte Perrara, Monte della Guardia, Fossa del Monte, Punta Capparo and many other points in Lipari, and in the great modern lava stream of Vulcano, it will be necessary briefly to notice. First Series.—The most perfect glass is found passing by insen- sible gradations into rocks of less strikingly vitreous lustre—pitch- stones or retinites—and thence through materials of pearly or porcellanous appearance into the most perfectly stony and crystal- line, almost indeed granitic, masses. This series of changes is effected 64 J. W. Judd—On Volcanos. without the appearance in the mass of any definite arrangements of crystallites.' Second Series.—Much more frequently, however, the passage from the vitreous to the stony series takes place by the appearance in the mass of scattered “‘spherulites,” composed of radiating crystals of felspar, entangling others of quartz, magnetite, and other minerals. Occasionally these spherulites are found scattered in a promiscuous manner through the vitreous matrix; but, far oftener, they assume very striking and definite arrangements; these are clearly seen to be the result of the conditions of pressure, tension, and slow- dragging movements to which the slowly consolidating mass was subjected. Sometimes the alternate laminz of vitreous or colloid and stony or crystallized materials have assumed a parallel arrange- ment, and the rock is almost as perfectly cleaved as a piece of slate ; at others they assume all the beautiful wrinklings and corrugations so characteristic of metamorphic foliated schists. The light which these remarkable products throw upon the mode of formation of many of the older rocks will be illustrated on a future occasion. Third Series.—At times the obsidian base of the rock is porphy- ritic, that is to say, it has crystals, often large and well formed, most commonly of brilliant sanidine, but not unfrequently of quartz, hornblende, or black-mica, floating through its mass. It then as- sumes the characters of an “ obsidian-porphyry ” (porphyritic obsidian). No one can study this rock, as exhibited in Lipari, without being convinced that the crystals which it contains were ejected, ready-formed, with the lava as it issued from the volcanic vent. Not only is there no trace of crystals in various stages of form- ation, as in the case of the sphzerulites, etc., but sometimes pumiceous masses, evidently blown out of a volcanic vent, may be found en- tangling just such perfect crystals. We shall not at present enter on the discussion of those interesting problems which the phenomena of these perfect crystals of minerals of such different degrees of fusi- bility, floating in the same liquefied highly siliceous magma, must suggest to every geologist. We shall only notice, in this place, that the combinations of these ejected crystals with those gradually developed in the mass by the growth of crystallites, the whole modified by the peculiar mechanical conditions to which the masses have been subjected, result in the formation of rocks of wonderful diversity, exquisite beauty, and remarkable suggestiveness to the petrologist. Fourth Series.—Fresh complexities of rock structure are originated and new varieties of lava produced, when, in either of the kinds already noticed, disengagement of volatile materials in the midst of the mass began to take place. The vesicular cavities thus originated were variously modified by the strains and movements to which the plastic mass was subjected. The most stony and highly crystalline, as well as the most vitreous varieties of these lavas, are thus affected 1 The exceedingly beautiful and clear obsidian of Lipari, like that of Mexico, has been employed by the ancient inhabitants of the island for cutting instruments and weapons. J. W. Judd—On Volcanos. 65 by the more or less complete disengagement of their volatile con- stituents ; and while in the former, cavities originate which are occasionally lined with the most beautifully developed crystals of the component minerals of the rock,—in the latter, a laminated struc- ture is produced, the planes of which sometimes coincide with, but not unfrequently cross, those produced by the devitrification of the mass under pressure. But this attempt at a classification is far from exhausting the varieties of the beautiful quartz-trachytes of Lipari. New forms are originated through masses of obsidian being broken up and entangled in a stony matrix, or by glassy streams enveloping stony or perlite fragments, or, as is not unfrequently the case, by their catching up in their flow angular fragments of lavas of different composition, and belonging to earlier periods of eruption. Thus are originated the most singular brecciated structures, and rocks of very peculiar and, at first sight, puzzling character are produced. When, however, these rocks are studied by the aid of the micro- scope, new features of interest continually make their appearance, only a very few of which it will be possible to notice in this place. In the most clear and translucent volcanic glasses which have yet been examined, the beginnings of the process of devitrification can always be detected. Minute acicular crystals of felspar (Belonites) are seen, which, in a later stage of development, assume rectangular forms and ruin-like terminations, and thus gradually approximate to the ordinary characters of sanidine crystals. Other acicular or filiform crystals of hornblende (Trichites) appear and combine into radiating groups or tree-like masses of marvellous beauty. Where these crystals reach the surface of a cavity in the lava, free develop- ment of them often takes place, and we are enabled to study their nature and characters with the greatest facility. Most frequently, however, the crystals unite in radiating masses, giving rise to those globular concretions known as spherulites. In some cases the formation of these spherulites has been determined by the liberation, in the midst of the vitreous mass, of an infinitesimal bubble of volatile matter. By the development of these crystalline globules with such exquisitely beautiful concentric and radiated in- ternal structures, the peculiar forms and distinctive opalescent lustre of “perlite” is originated. Nowhere, perhaps, can better materials be found for illustrating the development of these peculiarly interesting structures in vitreous rocks than in Lipari. Some of the pearlstones of this island, as, for instance, that of the lava-stream above Canneto, contain sphzerulites of the size of peas. To attempt anything like an adequate account of the varieties assumed by the crystalline interiors and semi-vitreous envelopes of these, would require numerous figures and an amount of detailed description which would be out of place in these sketches. It is in the northern part of Lipari that we find the best examples of the volcanic cones, craters, and lava-streams of the latest period of eruption in the Lipari Islands. Supposing a furnace containing many millions of tons of liquefied DECADE 11.—YOL. II1,—NO. Il. 5 66 J. W. Judd—On Volcanos. glass were allowed to pour forth its contents in a stream extending to a length of some miles, and to a thickness of hundreds of feet, what would be the nature of the phenomena, attending its outburst, and of the products which would result from its gradual solidification ? This is no idle problem; for the solution of it may be found by the geologist at Campo Bianco and Rocche Rosse. Campo Bianco or Monte Pelato is a volcanic mountain (see Fig. 8), -composed entirely of the whitest fragmentary pumice, the highest portion of the crater-ring of which rises to the height of more than 1500 feet above the sea-level. This is partially embraced (as is Vesuvius by Somma) by the relics of an older and far larger cone of the same materials, which culminates in Monte Chirien, having an elevation of nearly 2000 feet. The soft white pumice tuffs of the flanks of both these cones have suffered greatly from denuding forces, acting on their light and incoherent materials, and giving rise to those long furrows producing the “umbrella form” which is admirably exemplified in them. The crater of Campo Bianco presents at its bottom a flat plain, covered with comminuted pumice-tuffs, and now forming a most productive vineyard at a level of 892 feet above the sea; its walls rising almost vertically around it to heights of from 400 to 600 feet on the northern, western, and southern sides. On the north-eastern margin of this crater, however, a petrified cascade of vitreous lava rises 100 feet above the crater-floor, and, sweeping away all that side of crater-wall, has poured with a current, half a mile in breadth, down to the sea. This lava-stream, now covered with a reddish-brown coating from the oxidation of its iron, is the Rocche Rosse. Near the point where it issues from the crater, a deep “bocca” exists, once evidently the place of discharge of powerful steam-jets—now an awful pitfall, which the islanders avoid and speak of with terror. The surface of the lava presents a most striking example of those rugged cooled surfaces, like the Cheires of the Auvergne, and pre- sents one of the wildest and most desolate scenes which it is possible to imagine. The traversing of it isin many places a very difficult task. Other similar cones, craters, and lava-streams abound in Lipari. On the western side of Monte Chirien, at an elevation of more than 1700 feet, is a second crater, much ruined, that of the Piano dell’ altra Pecora; and on the south side of Campo Bianco is another, that of Forgia Vecchia, or Monte Perrara, at an elevation of 968 feet, from which another stream of vitreous lava flows to the sea. At the head of this lava-stream no less than three mouths com- municating with abysses of unknown depth, similar to that of the Rocche Rosse, are seen. They doubtless mark the sites of explosive discharges of steam. At Canneto is an older stream of perlite, which probably flowed before the present crater of Campo Bianco was formed. The craters of the southern part of the island of Lipari give rise to lavas similar in composition to those of the north end of the island. In the former, however, the stony characters predominate 67 J. W. Judd—On Volcanos. ~- ~ Monte Chirien ; aE Monte Sant ’Angelo ; + * Monte di Tre Pecore Si ocainn Fic. 8.—View of the breached crater of Campo Bianco, with the lava-stream of Rocche Rosse, seen from the sea. (in the distance). 68 J. W. Judd—On Volcanos. over the glassy, while in the latter the reverse is the case. Old craters can be traced at Fossa del Monte, Monte della Guardia, and other points in the district. Some of these lavas have undergone a certain amount of alteration from the passage through them of acid gases, as is shown by the fol- lowing analysis by Abich of a Liparite from Monte della Guardia : SCA ae iid seek RoRmeCmuNee Es WEE cose Pinte ROS2S0) AMUMIN a 41 his ech mentee eepeetey ileceforaee Wve vaeloEO Oxidetof Tron 2 sae eee eee thee leet begoe eo DAMe tag ik, bee een hen Baer ec eee) | HORS Sea. Sm Sie hi Sas COG DOO ae pected) Potash Aes ren acetyl el eit cnewel” terndiutes aleora Soda... 4-29 Volatile materials, principally Sulphur and Sul- phuric Acid . 4-64 While the action of the acid gases upon the oxdlioncs trachytes of the second period of eruption in Lipari gives rise to the formation of selenite and basic sulphates of iron,—sulphate of alumina and free sulphur are the products of the same action on the later formed quartz-trachytes. To those who regard the fluidity of lava as the result of simple fusion, nothing can be more startling than the behaviour of these obsidian currents of Lipari. While, as is well known, some of the highly crystalline lavas of Vesuvius have flowed with the most astonishing rapidity, these glassy masses have evidently possessed only the most imperfect fluidity. In proof of their viscosity I may point to the manner in which the modern obsidian stream of Vulcano is confined to the steep slope of the cone, at the bottom of which it has piled itself up in great hummocky masses, instead of spreading out in a fan-shaped manner, or continuing to flow in a stream over the smaller slopes. The same fact is more or less strikingly illus- trated by all the glassy lava-streams. But even more decisive evidence of this slow movement of the obsidian lavas, and of the vast amount of tension and pressure to which their masses have been subjected, is afforded by their internal structure. Every conceivable condition of plication, crumpling and puckering, is illustrated by the sections afforded either in sea-cliffs or the ravines cut by mountain torrents in these obsidian lavas. The appearance presented at two different portions of the same lava-streams, as exposed in a steep escarpment at Porto delle Genti, south of the city of Lipari, are shown in Fig. 9: in A the mass has been bent into large but sharp folds ; in B the folding has been accompanied by the most intense crumpling and puckering. As we shall show on a future occasion, these mechanical forces have combined with the forces producing devitrification to produce some most interesting phenomena in the minute internal structure of the rocks. There can be little doubt that the last great effort of volcanic activity in the island of Lipari was that which produced.-the present crater of Campo Bianco, and the lava-stream of Rocche Rosse. In spite of traditions and obscure historical allusions, I find it difficult J. W. Judd—On Volcanos. 69 to believe, so much have the hard masses of lava suffered in places both from marine and subaerial denudation, that any record of this great eruption can have survived. Fic. 9,—Sections of quartz-trachyte (Liparite) lava-streams at Porto delle Genti, illustrating the folding and crumpling of their interior portions, produced by the slow movement of the viscous mass. A. Exhibits a series of broad folds. B.A series of most complicated puckerings, exactly like that seen in many gneissose rocks. To their permeation by gases and vapours, probably during the latest period of eruption, the altered trachytes and tuffs, with their veins of selenite and other minerals, are probably due. Only two vents, constituting the dying efforts of volcanic activity, once so powerful in this island, still remain, being situated on its western side; one of these is at Bagno, or la Fonte di San Calogero, and gives rise to a hot mineral spring; the other is at Bagno Secco, a little to the northward, and only dry stream, charged with hydro- chloric and sulphurous acid gases, is evolved from it. The hot spring of San Calogero has long been celebrated for its curative properties, having been mentioned by Diodorus Siculus; in 1870 a bath-house and hotel were erected here by the municipality of Lipari. In a medical tract by Dr. Guiseppe Hincotta, the use of these waters in various rheumatic and cutaneous affections is stated to be attended with the most beneficial results. The water, which has a temperature of 198° F., that of the sur- rounding atmosphere being 77°, has been analyzed by Dr. Ferdinando Rodriguez, and also by Prof. Guiseppe Arrosto, of the University of Messina. It contains free carbonic acid and sulphuretted hydrogen, with the carbonates of lime and magnesia, and chlorides of calcium and sodium, and a little organic matter. The following is the result of Prof. Arrosto’s analysis : 70 = Dr. Walter Flight—fHistory of Meteorites. PiOXy Ren eee scns tree beeen bese) tices ede:) Mracwee ea OLO0oT INGO PEN ee tetee shel ny visa +) Race otatoa 0:0126 CanboniceAcidg eres yy con tae) eee ieee 0°2758 Sil PHUEICPACIC Wess) | i 7 63° oe ens 63° 26’ paul aGerey 86° Nae aa 82° 53’ cae 85° 40’ 1092 ree ae 104° 2’ PAY 110° 47’ 119° a4 119° 45’ ee 117° 49’ while the angles which the etched lines form with lines parallel to 111 are: Observed. Calculated for : 100 11 23° 2000 eee 30° 58’ ase We ail 45° 000 ee 45° 0’ ee 45° 24’ 58° ae 900 SOP 9 a5 48° 58’ 69° 60 nae 71° 34 nie 70° 30’ These observations place beyond doubt the fact that the deeper lines thus brought out are the usual lines of etching. 1J.G. Neumann. Aus der Naturwiss. Abhandl. (W. Haidinger), iii. Ab. 2, 45. 76 Dr. Walter Fhght—History of Meteorites. The cavities, produced by the action of acid, are very small, about 0-005 mm. across, and have a rounded, sometimes quadratic, outline ; the more perfect having the form of rounded cubes. ‘They are most - abundantly met with on the fillets alluded to above, those in the same piece of beam-iron being similarly orientated, and it is to them and the parallel serration of the fillets that the erystalline damas- kining is due. In the beam-iron are inclosed schreibersite and troilite, but graphite was not observed. The schreibersite is only met with in this form of iron, and occurs there in rounded particles and elongated forms, which proceed from plates of this mineral, many of which lie parallel to an octahedral face. It occurs very frequently round about the remarkable lamelle of troilite (see infra) that lie parallel to the faces of the cube. The fillet-iron (Bandeisen), or tinite, presents itself on the etehed surface in the form of prominent bands or fillets between the stripes of beam-iron, and they are sections of lamelle lying parallel to those of the beam-iron,—in other words, to the octahedral faces. This form of iron, though in such thin plates, is found by the microscope to be a fine tissue of heterogeneous substances. One of these is nickel-iron, which coats the lamella of tanite. A section of this mineral is dull in appearance, but the boundary is brilliant ; while outside it, lie brilliant points of not unfrequently regular form. The framework and the points have the yellowish colour of nickel- iron. The duller field, when strongly magnified, is seen to consist of exceedingly fine plates of nickel-iron, which lie in two different directions, for the lines intersect at 90°. The material lying between these plates, which has been removed in greater abundance, is pure iron. The lamellz of tanite are often penetrated and traversed by fine plates of beam-iron. The interstitial iron (Filleisen), which, as the name implies, occupies the areas between the minerals already mentioned, is abundantly present in masses sometimes extending to the breadth of lcm. It is made up of tanite and beam-iron, and isa representation of the structure of the entire meteorite on a smaller scale, with such modifications as seem to indicate that after the large lamelle of beam-iron and tiinite were already formed, the matter inclosed between them became solid, and, shaping itself in accordance with the same laws in a limited area, produced this variety of meteoric iron. It occurs in two forms that vary but little from each other. In one, fine stripes of beam-iron intersect, while between them is tanite: this is an exact reproduction of the coarser structure of the meteorite. In the other (and this is observed in the larger masses) the square form is provided along its boundary with stripes of beam- iron, the remainder appearing granular through a number of little particles of beam-iron being ranged together with nickel-iron between them. The occurrence of troilite in lamellee has been observed for the first time in this iron. They lie parallel to the cubic faces, and, unlike those of tanite, do not traverse any considerable portion of *® Dr. Walter Flght—History of Meteorites. th the etched surface. The largest are 3:5 cm. long and 1:5 wide, and have a thickness of from 0:1 to 0‘'2 mm. They havea sharp outline, homogeneous structure, and are easily recognized as consisting of the brittle bronze-coloured sulphide which decomposes with acid. These lamellz are covered on either side with a layer of beam-iron, which separates them from the tanite, the interstitial iron, and the lamelle of beam-iron that are parallel to the octahedron; whenever one of the last-mentioned plates happens to be situated near a lamella of troilite, it will be found that the troilite has broken through it. : The troilite seems to have been formed first. After it had become covered with a layer of beam-iron, the octahedral lamellae (the tanite and the beam-iron) appear to have been developed; and last of all the interstitial mass, likewise in accordance with the law which governed the formation of the octahedral lamelle, The troilite of this iron occurs almost entirely as cubic lamella, but rarely in the familiar nodular form. On examining the irons of the Vienna Collection, Tschermak discovered thin plates of troilite, -covered, as above, with beam-iron, in the meteorite of Jewell Hill, Madison Co., North Carolina, found in 1856. The lamelle are just as abundant, have the same orientation as those of the South American iron, and are about one-third the size. These two irons differ but slightly in composition : Atacama. Jewell Hill, Iron... aA 91°53 SS ee 91:12 Nickel ... xe 7:14 566 A 7°82 Cobalt ... 25 0:41 idole 000 0°43 Copper ... we trace. fai “Be trace. Phosphorus... 0°44 ae 200 0-08 99°52 99°45 The paper is illustrated by four beautifully executed plates; two showing the markings on the surface of the mass, the other two the figures developed by etching a section.’ 1 The following meteoric irons and siderolites from this region, several of which probably belong to one fall, have now been recorded; the greater number are preserved in some well-known collection, and have been submitted to examination. (1). 1827. Stderolite (Brit. Mus. Coll.). Atacama, Bolivia.—Reported on by Bollaert (Journ. Royal Geogr. Soc., xxi. 127); and by Reid (Chambers’ Jour., March 8, 1851), who places the locality in lat. 23° 30’ S. and 45 to 50 leagues from the coast. According to R. A. Philippi (Jahr. Min., 1855, 1), masses weighing 120 to 150 lbs. were found one league from Imilac, in the centre of the Atacama Desert. Imilac is 35 leagues from the coast, 40 leagues from Cobija, and 35 from Atacama. Rose places the locality in Chili. (In Stieler’s Atlas, Atacama Mt. is in Bolivia; the Desert of Atacama, partly in Chili, partly in Bolivia; the Province of Atacama, in Chili; and Atacama Alta in Bolivia.) This will be the meteorite analyzed by Frapolli, and described by Bunsen in 1856, the metallic portion of which contains : Fe=88-01; Ni=10:25; Co=0'70; Mg=0-22; Ca=0-13; Na=0-21; K=0:15; P=0-33 =100-00. (2). 1858. ron (Brit. Mus. Coll.). Atacama, Bolivia. (3). 1862. Siderolite (Brit. Mus. Coll.). Sierra de Chaco, Desert of Atacama.— Rose places this in Chili, and the position of Chaco is stated to be lat. 25° 20'S. and long. 69° 20’ W.; he (Ber. Berlin Akad., 1863, 30) could not develope etched figures 78 Dr. Walter Flight—History of Meteorites. Found 1870.—Iquique, Peru.’ This mass of iron was discovered on a mountain slope on the western border of the pampa of Tamarugul, ten leagues east of the harbour of Iquique. It lay at a depth of from two to four feet below the surface, being imbedded partly in a bed of nitre, of the _ hardness of stone, partly in the overlying soil. When found, the metal was so hard that two chisels were broken in an attempt to remove a fragment of it. A piece that had been heated became malleable, and was beaten into very thin plates. The Iquique iron has the form of a plate, 6 cm. in thickness; on one side it is convex, somewhat bent inwards on the other, with a on the nickel-iron, which had the composition: Fe=88:55; Ni=11-:5; the meteorite resembles that found at Hainholz some years earlier. (4). 1863. Siderolite (Brit. Mus. Coll.). Copiapo, Chili.—In the Amer. Jour. Se. (1864) xxxvii. 243, C. A. Joy describes a siderolite from the Janacero Pass, 50 English miles from Copiapo, Province of Atacama, Chili. The spec. gravity of his specimen is 4:35, and it was composed of nickel-iron, troilite, and silicates. J. L. Smith (Amer. Jowr. Sc., xxxvili. 386) considers it to be identical with the Sierra di Chaco meteorite described by Rose (see No. 3). Captain Gilliss, of the United States Observatory at Washington, believes ‘ Janacera’ may be a misprint for ‘ Jarquera,’ the name of a river which rises in one of the Atacama passes. (5). (No date). Siderolite (Brit. Mus. Coll.). Atacama, Bolivia. (6). 1866. ron (Brit. Mus. Coll.). Cordilleras of Atacama, Chili.—M. Daubrée (Compt. rend., Ixxvi. 569) describes a large iron, weighing 104 kilog., acquired in 1867 for the Paris Collection. It was found in November, 1866, on the west slope of the high cordillera of the Andes, between the Rio Juncal and the Salt-works of Pedernal, 50 leagues N.E. of Paypote. (The difficulty of transporting heavy masses across such an arid region is very great; according to Dr. Philippi (Zhe Times, August 31st, 1874), it only rains about once in from 20 to 50 years.) This mass bears on the surface the systems of lines which Tschermak observed on the Ilimaé iron, and Damour finds them agree in composition. They are probably all members of the same aerolitic fall. (7). (No date). ron (Brit. Mus. Coll.). Sierra di Deesa, Chilii—Under this name M. Daubrée has given (Compt. rend., \xxvi. 571) a description of a brecciated iron from the cordillera of Deesa, near Santiago, acquired in 1867. It closely re- sembles the iron found in 1840 at Hemalga, in the Desert of Talcahuayo, in Chili. It contains 2°4 per cent. of silicate, which has been chemically examined by Meunier. (Sitz. Wien Ak., \x1.). 8). 1866. Tron (Brit. Mus. Coll.). Juncal, Cordilleras of Atacama, Chili. ts . 1864. Siderolite (Berlin Coll.). Atacama, 50 miles from Copiapo.—It appears probable from the rough description of the locality that this may be the same meteorite as the one mentioned under No. 4, although the dates do not corre- spond. In that case J. L. Smith’s view of the identity in character of the meteorites will have to be extended to Nos. 3, 4, and 9. (10). 1870. ron (Vienna Coll.). Ilimaé, Desert of Atacama, Chili. . (11). (No date). Siderolite. Taltal, Desert of Atacama.—J. Domeyko (Compt. vend., viii. 551) describes some masses of considerable size on the high plateau of the Desert near the copper mine of Taltal, south of Imilac. The spec. gravity of a fragment was 5°64. (12). 1863. Siderolite (Vienna Coll.). Copiapo, Chili. —Described by Haidinger (Sitz. Wien Akad., xlix. 499), as a coarsely granular brecciated meteorite. The nickel-iron, according to Von Hauer, consists of: Fe=93; Ni=6-4. (13). 1859. ron? Toconado, Desert of Atacama.—J. J. von Tschudi, writing under the above date to Haidinger (Sitz. Wien Akad. , xlix. 494), mentions a meteoric mass, weighing 80 arobas (20 cwt.), which lies 20 leagues N.E. of Toconado. He states that it agrees in structure and appearance with the Atacama iron lying 50 leagues southward. 1G. Rose. Abdruck aus der Festschrift der Gesell. Naturforsch. Freunde zu Berlin, 33, Berlin: Diimmler, 1873. : ie Dr. Walter Flight—History of Meteorites. 79 deep cavity on one part of the surface. The former is covered with ridges, running obliquely across its side, and in most cases parallel to each other. The weight of this block of metal is 21 lbs., and the specific gravity 7-925. When cut, it takes a fine polish, and exhibits strong metallic lustre and a steel-grey colour. Four analyses have been made, three by A. Raimondi, of Lima, and one by Rammelsberg, that last quoted, with the following results: I II. Til. IV. Trento (ei AS 4s eons GLE Seu ST OOM 8IE6G RTH caso SOE RORY OT Nee SIDER? ek TERS) Cabal see a 8 80-19 Insoluble portion ... 500 coe see 2706 99-93 99-98 99:97 100-00 The insoluble constituents were: iron 2°17; nickel 0°37; phos- phorus 0-05; and a residue, that withstood the action of hydro- chloric acid, 0:07. ; The attention of the reader will be taken by the unusually large per-centage of nickel present in this meteorite, it being as high as, or higher than, that of the aerolite of Shingle Springs (see page 28). We saw that the American iron, and the one from the Cape of Good Hope, found at the end of last century, resembled each other not only in the ‘quantity of nickel in the alloy, but im the fact that neither of them developed figures when etched. The Peruvian iron forms a third example of this class, for it also shows no Widmannstiattian figures : by treatment with acid it takes a pale grey colour, and is dull. In lieu, however, eight fine straight parallel stripes, singularly unlike any markings usually observed, are seen to traverse the etched sur- face, nearly directly across the greatest length of the block. Four of these crossing near the middle of the surface appear to be equidistant from each other, like lines on ruled paper; the remaining four lie in pairs, one on the right, the other to the left of the group of four, the whole number, as stated, being in parallel position. The spaces between the members of the first pair and of the other pair respectively exhibit for some distance the same lighter surface that gives prominence to the stripes themselves. These stripes do not appear to be in any way connected with the ridges on the outer surface, and though evidently brighter than the face generally when seen in certain directions. are duller than it when viewed in others. Very similar stripes were noticed on the Cape iron’ already men- tioned; in fact, till Rose made his observations, it was the only iron which was known to exhibit such phenomena. As to their cause, the author did not advance any explanation beyond attributing them to the position of the small particles composing the stripe. They present some of the characteristics of the plates of beam-iron observed in the Atacama and many other irons. This iron apparently contains no sulphur, and the sections of little inclosed crystals, such as those met with in the Cape iron, which 1G. Rose. Aus Abhandl. Berl. Akad. Wiss., 1863-70.—E. H. von Baumhauer. Archiv. Neerland. des Sciences Exactes et Natur., i. 377. 80 J. A. Birds—On the Isle of Man. Baumhauer believed to be of pyrites (FeS,), but which Rose main- tained were of magnetic pyrites, were in vain sought for. Two plates, copied from photographs of the aerolite, are appended to the paper. It rarely happens that Widmannstiittian figures are developed in irons containing more than nine per cent of nickel. With a know- ledge of the difficulties attending the complete separation of nickel and cobalt from iron and of the different action of the re-agents, employed to bring these metals into solution, on the phosphides, rich in nickel, which frequently accompany them, it would not be advisable to lay too great stress on the results of earlier analyses of meteoric irons as pointing to any general conclusion when the details of the processes made use of cannot likewise be studied. It is worthy of note, however, that the irons mentioned below, with the per-centage of nickel found in them, give lines occasionally, but no ' figures : Octibbeha Co.=59-69 ;-Caille=17-37; Babb’s Mill=17-1, 14-7, and 12:4: Howard Co. (1862) = 12°29; Atacama (1862) =11-5; Krasnojarsk = 10:78; Tucuman=10-0; Zacatecas=9°89 ; and Szlanicza=8°91. While the following irons exhibit them in great perfection : Elbogen=8:5; Lion River=6:7; Lenarto=655; Modoc=6°35; Sevier Co.=6°5 and 5:8; Schwetz=5:77; Tabarz=5:69; Cambria=5:7 and 5:0; Braunau=5'5; Asheville=5:0; and Ruff’s Mountain=3'12. (To be continued in our next Number.) TV.—On tHE Post-PLiocENE FoRMATIONS OF THE IsLE oF Man, By J. A. Birps, B.A. T is nota little remarkable that, while almost every part of England and Scotland, and particularly the district of “the Lakes” and North Wales, has been abundantly studied and written about,— . and while Ireland also has been almost completely surveyed,—the Isle of Man should not only have been left untouched by the Geological Survey, but, latterly at least, should have well-nigh escaped the attention of geologists altogether. With the exception of three or four papers by the Rev. J. G. Cumming, published in the Quarterly Journal of the Geological Society, and their embodi- ment in a more popular form in his History of the Isle of Man, and Guide Book,’ scarcely anything appears to have been written 1 The following is as complete a list as I have been able to glean of all works or papers relating to the geology of the Isle of Man :— “ An Account of the Isle of Man.” By Geo. Wood. 1811. “A Mineralogical Account of the Isle of Man’’ By Dr. Berger. Trans- actions of the Geological Society, 1st series, vol. 11. 1814. “A Supplementary Notice of the same.” By Prof. Henslow. Trans. of the Geol. Soc. Ist series, vol. v. A Notice of the Island in Macculloch’s ‘“ Western Isles of Scotland,” vol. ii. . 516. 1819. rane Memoir on the Discovery of the Megacaros Hibernicus in the Isle of Man.” By Dr. Hibbert. Edinburgh Journal of Science, No. 5. 1826. 6. ‘On the Stratification of Alluvial Deposits in the Isle of Man.”’ A Pamphlet by H. R. Oswald, Esq. Douglas, 1823. 7. ‘On Concretions in the Pleistocene Deposits of the North of the Island.” By Hugh Strickland, Esq., F.G.S8. Proc. Geol. Soc. vol. iv. 1843. 2 Fo» Np J. A. Birds—On the Isle of Man. 81 upon the geology of the island, besides some Memoirs published in’ the infancy of the science, or a few brief notices of special points since. . Mr. Cumming, who for many years was Vice-Principal of King William’s College, Castletown, appears to have studied the geology of the little country very thoroughly, and has left an excelient account of it, illustrated with several maps and sections. Pro- bably the Geological Surveyors, when they come to explore the island, will find little to correct or add to in the portion of Mr. Cumming’s works which relates to the older rocks—unless it be to determine positively the age of the Silurian schists. With regard, however, to the later, or Post-pliocene accumula- tions, the progress made in this portion of geology since the publi- cation of Mr. Cumming’s “History” in 1848, will, I think, necessitate very considerable changes. Mr. Cumming divided these formations into two classes: 1. Boulder-clay ; 2. Drift-sand and gravel; and he seems to have regarded the Boulder-clay as all of the same age. This I believe to be a fundamental error, which throws into confusion the whole account of the order of these deposits. It is hardly necessary to remind readers of the GroLoGicAL Magazine of the three or four great periods in the hypothetical history of the last geological age of the British Isles, and of the whole of Northern Europe and America, as it is summed up by Sir C. Lyell in the last editions of his ‘ Principles’ and ‘Elements,’ and in the ‘ Antiquity of Man,’ viz. :— 1st. A continental period, when the land was much higher than at present, and all, except perhaps the summits of the highest moun- tains, was covered with a thick sheet of ice. 2ndly. A period of gradual submergence, in the later part of which icefloes and icebergs drifted to and among these islands, and their highest portions formed an archipelago in the North Sea. 3rdly. A period of emergence ending in a second continental con- dition, when, however, the land was probably not so high as in the first period, though glaciers occupied the higher valleys. 8. “On the Geology of the Isle of Man.” By the Rev. J. G. Cumming. Part I. Paleozoic Rocks. Part II. Tertiary Formations, with Plates Xiv.-Xvli. Quart. Journ. Geol. Soc. vol. ii. 1846. 9. “On the Geology of the Calf of Man,” by the same. Quart. Journ. Geol. Soc. vol. iti. 1847. 10. “The Isle of Man: its History,” ete., by the same. London, Van Voorst, 1848. 11. “On the Superior Limits of the Glacial Deposits in the Isle of Man,” by the same. Quart. Journ. Geol. Soc. vol. x. 1854. 12. “A Guide to the Isle of Man,” by the same. London, Stanford, 1861. 13. “On certain Tracks in the Manx Slates.” By Thos. Grindley, Esq. Gxou. Mag. Vol. II. p. 542. 1865. 14, “On the Geology of the Lake District and the Lower Silurian Rocks of the Isle of Man.” By Professors Harkness and Nicholson. Quart. Journ. Geol. Soc. vol. xxii. 1866. 15. “Practical Guide to the Isle of Man.” By H. J. Jenkinson. London, E. Stanford, 1874. Contains Chapters on the Mineralogy and Geology of the Island. DECADE II.—VOL, II.—-NO. II. 6 82 J. A. Birds—On the Isle of Man. 4thly. A second submergence, attended probably with many oscil- lations, until St. George’s and the English Channels were formed, and the British Isles at length assumed their present shape. I am not aware whether this hypothetical history—which, until some more satisfactory theory is suggested, must be assumed as the basis of all reasoning upon the Post-pliocene Formations—originally led to their threefold division into an Upper Boulder-clay, a Middle Drift of sand and gravel, and a Lower Boulder-clay, corresponding to, and by some supposed to be the product of the first three periods; but it seems not improbable. However this may be, the division now appears to be fully supported by facts, and it only requires some modification in the reference of the several members to their respective periods of for- ’ mation to render it, apparently, satisfactory. Thus, instead of assuming that the Lower Boulder-clay corresponds to and was entirely formed by land-ice during the first continental period, we believe that the materials of it were then ground up by land-ice and subsequently deposited in the sea, from the time when the land began to sink until perhaps the middle of the period of sub- mergence. Again, the Upper Boulder-clay was not formed altogether during the second continental period, but probably it was deposited during the middle or towards the latter end of the emergence, and continued to be deposited for some time during the second submergence; the interval between the middle of the first submergence and that of emergence being one in which a temperate climate prevailed and no glacial deposits were formed. The simple diagrams given on page | 83 will illustrate my meaning at a glance. Now to apply the above explanation to the glacial deposits of the Isle of Man. The whole northern portion, about a third of the island, north of the road from Ramsey to Kirk-Michael, is occupied by the Lower Boulder-clay and Middle Drift sands and gravel. It is best seen in the cliffs from Sea-view to Port Cranstal, at the eastern end of the Bride Hills, and again at the western end of the little chain at Blue Point. The sections are very similar, and con- sist of stratified yellow sand and gravel at the top, averaging 10 to 15 feet, succeeded by a great depth of brown clay, interspersed with patches of sand, and here and there a bed of gravel, and the whole attaining a maximum thickness, at Point Cranstal, of from 100 to 150 feet. The clay contains but few stones. The gravel-beds consist chiefly of local schist and quartz, with a very large admixture of stones foreign to the island—Permian rocks, chalk flints, granites, syenites, traps, porphyries, etc. The largest accumulation of pebbles from these beds is round the Point of Ayre, where the beach at low water, for a distance of nearly two miles, is composed of several terraces of shingle, apparently of considerable depth, and having a total width of 80 to 100 feet. Searching along this shore I found, besides the flints above mentioned, which must have come from the north-east of Ireland, a very great variety of granites, syenites, etc., probably part from Ireland, and part from the south of Scotland, J. A. Birds—On the Isle of Man. 83 First ContTInENTAL. PERIOD.. EMERGENCE... rah The same. a SEA B SEA. Upper Boulder- A clay formed by nN coast-ice and 0c- casional foreign icebergs. SEA. | Maximum Height of Land.. SEA. First SUBMERGENCE. 1 The Lower Boulder-clay would be form- Szconp ConTINENTAL PEnrop. ing, at first beyond the 100 fathoms. line (see Map in.“ Account of the Isle of Man,”’ p- 279), and afterwards among the British Isles till the land sank down to about the same elevation as at present, represented by— A ae sade SEA. Maximum Height of Land. SEA. Whilst the land was sinking to SECOND SUBMERGENCE. B SEA. SEA. Upper Boulder-clay, continuing to Middle Drift Sand and Gravel would be be formed by coast-ice and occasional formed chiefly by icefloes and icebergs icebergs. - drifted from foreign coasts. A C > Varn A temperate climate and no glacial formation. : BEN SEA. Present Elevation. 84 J. A. Birds—On the Isle of Man. _ together with a profusion of traps and porphyries, some I believe from the Cheviots, and several specimens of Prehnite (or one of the same family of minerals) which (according to Hall’s Mineralogist’s Directory) is not to be found in siti nearer than Beith in Ayrshire, _ or, in abundance, than Renfrewshire, or the Kilpatrick Hills in the neighbourhood of Glasgow. The whole northern plain of the island—as may be seen by sections at Riversdale, on the banks of the Sulby river near Ramsey, on the roads to Kirk-Andreas and Kirk-Bride, and between the latter village and Blue Point, in the neighbourhood of Ballaugh, at Turby, and thence south to Kirk-Michael—is composed of similar deposits, all | ‘belonging, I believe, to the Lower Boulder-elay and Middle Drift. _ The same formations, or at least the sands and gravel, are to be seen at Peel in the west, and may be traced for some miles up the central valley of the island. They may be seen again along the railway from Ballasalla to Port St. Mary. A considerable thickness of the sands appears in a cutting of the same railway near Port Soderick, and they must be or have been present in considerable strength at Douglas, as the sandy shore and beach of the bay has no deubt been formed from their remains; though it is difficult, now that the land has been built over, to find any good sections. If now we quit the shores, and ascend towards the higher ground and the mountains, we come to a totally different kind of deposit. It consists generally of a yellowish-brown, though occasionally bluish, or reddish, loam, containing angular fragments of almost exclusively local rocks, viz. Silurian schist with ‘ green-ash,’ green- stone, and quartz, together with a few fragments of Old Red Sand- stone, and a very few, if any not-derived, foreign rocks. This I believe to be the true Upper Boulder-clay. It may be traced from the southern extremity of the island, near Craigneesh (probably it is ~ a patch of the same which is marked by Mr. Cumming on the Calf Islet), to the northern corner of Port Hrin Bay, and thence along the southern base of the hills by Colby and Arbory, to Ballasalla. It is well seen in the cuttings of the railway thence to Douglas, and at the station there. It covers the cliffs at Douglas Head ; it may be seen at several points along the road from Quarter Bridge to Onchan, and capping the cliffs on the northern side of Douglas Bay; it is trace- able along the road above the valley of the Glass river from Douglas to Abbey Lands; it crowns the quarry at the side of the road from the Lunatic Asylum to Union Mills, is present in strong force there, | and may be seen in every cutting of the railway thence almost to St. John’s. In the north of the Island, too, one comes upon it directly on leaving the plain, as at the mouth of the Ballure Glen, at Ramsey, © and on the left or mountain side of the road thence to Kirk-Michael. It is present also in the banks of the Foxdale river. From the fact that this clay is found almost always at a higher level than the Middle Drift sands, and from its containing scarcely any but local rocks, and those always angular or in a very slightly rolled condition, I conclude that it is the wash of the mountains to- wards the later part of their rise and in the beginning of their second J. A, Birds—On the Isle of Man. 85 submergence in the sea, and due, partly to the action of the sea itself by tides and waves, partly to rainfall and an accumulation of snow and ice upon the land, combined with the most effective cause of all, the grinding of coast-ice swept along by violent currents. If, referring to the diagrams at p. 83, it be asked why the same kind of deposit was not formed .in the later periods, when the land was at the same height, as in the first submergence,—that is, why the Upper Boulder-clay is not precisely like the Lower Boulder- clay,—I can only suppose that there were other conditions besides the degree of elevation above the sea which would account for the difference, and, among these, perhaps the chief would be the enormous extent and mass of ice in the first period, forming a thick continental sheet, like that of Greenland now; while in the second period the ice was much more partial, and subject to disturbance which broke it up, and gave rise to ‘‘packing” and drifting. We must also remember that a portion of the sands and gravel of the previous deposits would be mixed with the later Boulder-clay— whence came its loamy character, and a proportion of, or perhaps all, the foreign rocks now found in it. At the end of his ‘History of the Isle of Man,” Mr. Cumming has given several sections, showing the Boulder-clay and Drift- gravel, in all of which he represents the former as extending under- neath the latter.1 My belief is that in this representation the Upper Boulder-clay, near the base of the mountains, has been confounded with the Lower Boulder-clay exposed in the coast cliffs, as at Point Cranstal, Blue Point, Turby Head, and Kirk-Michael in the north of the island, and perhaps also at Hango Hill in the south. Instead, therefore, of Mr. Cumming’s division into a Boulder-clay and Drift- gravel, I would propose another into— A. Newer Glacial Formations. Upper Boulder-clay, containing almost exclusively local rocks, angular, or very slightly rolled, with oceasional beds of sand and gravel. B. Older Glacial Formations. 1. Stratified sands and gravel, containing an abundance of foreign (English, Scotch, and Irish) rocks well rolled. 2. Lower Boulder-clay, with patches of sand and gravel, containing a small proportion of foreign rocks, In a word, I believe, from my own observation, that the con- clusions as to the order of the glacial deposits adopted by the Geological Survey for the north-west of England and for Scotland, and announced by Prof. Hull? as holding good for the east of Ireland, are true also for the Isle of Man. 1 See “ History of the Isle of Man,’’ by Rev. J. G. Cumming, plate viii. 2 See an article “Qn the General Relations of the Drift Deposits of Ireland to those of Great Britain,’ by Edward Hull, F.R.S., etc., Director of the Geo- logical Survey of Ireland, Grou. Mac. 1871, Vol. VIII. p. 294. 86 G. H. Kinahan—Asar, Esker, or Kaims. V.—Asar, Esker, oR Karms. By G. H. Kryauan, M.RB.1.A., ete. ie Ihave paid some attention te the Eskers of Ireland, perhaps I may be allowed to make a few notes on the papers of Mr. F. J. Jamieson recently read before the Geological Society of London, and the letter of M. Jespersen that appeared in the Grou. Maca. for December, 1874. These observers put forward the theory (if I understand them rightly) that these peculiar ridges of shingle, gravel, and sand may be in part glacial, they having been accumu- lated as marginal fringes to the different stages of the ice-cap that at one time covered the northern portion of the Continent of Europe, as it intermittingly retreated. This suggestion seems worthy of consideration, as possibly, if the ice-cap had an intermittent retro- gression, there would be fringes or ridges of shingle, gravel, and sand marking each rest, formed of the detritus from each successive portion of the ice that disappeared ; but such accumulations should be at different altitudes, and being carried by water off the ice, and deposited successively at its edge, should be stratified outwards,— or if the margin was retreating, they would be jumbled together. Gravel ridges answering these requirements may occur in places ; but if we examine into the facts connected with the great systems of eskers in Ireland, such a theory will not answer the requirements. The data connected with this phenomenon I have explained on former occasions,' and from those notes the following generaliza- tions may be extracted. First. The Esker ridges are usually stratified more or less in con- formity with the slopes of both their sides; the stratification evidently being due to currents coming in different directions. Second. The well- marked eskers usually occur on ground between the 100 and 350 contour-lines. Third. When the eskers run on to ground above the 300 contour-line, they break into shoals or irregular mounds or accu- mulations, while the shingle, gravel, and sand graduates into the drift of the country; let the underlying drift be normal Boulder-clay- drift, Moraine drift, or the, Glacialoid stratified drift. Fourth. The eskers or ridges occur in such places as it might be expected that tidal or other currents met ; either in open seas, in straits, in bays, cr estuaries. Fifth. The eskers or ridges may be divided into three kinds, namely: Fringe-eskers, margining high ground; Bar-eskers, stretching from one high ground to another ; and Shoal-eskers, com- posed of short ridges and hillocks mixed irregularly together. While Siath. From the charts we learn that nearly similar fringes, bars, and shoals are now being formed in the shallow seas, the straits, bays, and estuaries, by tidal and other currents. If the great system of eskers in Ireland was due to detritus 1 On the Eskers of the Central Plain of Ireland, Dublin Quart. Journ. Science, vol. iv. p. 109, and Dublin Geol. Soc. Journ., vol. x. Notes on some of the Drift in Ireland, Dublin Quart. Journ. Science, vol. vi. p. 249, and Journ, Royal Geol. Soc. Ireland, vol. i. pt. iii. G. H. Kinahan—Asar, Esker, or Kaims. 87 margining the ice-sheet at its different periods of retreat, they scarcely could be so regular in character or on such similar levels over the whole island; besides, the stratification of the materials com- posing them ought always to dip in one direction, or be irregularly jumbled together. In some fringe-eskers, as pointed out in one of the papers previously referred to, the dip may in places be only to one side, but the reasons for this peculiarity are explained. If the sea, however, on account of the advance of the ice-sheet, had . risen, all bars, fringes, and shoals due to it would be formed on the same or nearly similar levels, which, during the great ‘“‘ Hsker-sea period,” would be at heights lower than 350 feet; while to a sea of a lesser area and at a relative lower level would be due the esker ridges in the low level valleys, such as the esker across the valley of Lough Corrib, Co. Galway. Although it seems to me that the great systems of eskers in Ireland are due to the meeting of currents in a tidal sea, [such a theory having been promulgated about ten years ago, and since confirmed by the observations of myself and colleagues], yet I am far from imagin- ing that all eskers are due to marine currents, as some eskers are eolian, that is, principally formed by the wind; eskers of this class from half a mile to seven or eight miles in length being not un- common in places.on the east and south-east coast of Ireland, while inland in a few places are ridges of fine sand that probably had a similar origin. Furthermore, there are eskers evidently formed by the combined action of the waters of rivers and lakes assisted by wind, while in some of the Irish hills, and even on ridges, are eskers far higher than the limits of the “‘ Esker sea,” evidently due to some kind of waterwork, and not to wind action. Such eskers, indeed, might possibly be the remains of the sea work when its level was much higher than at present; this, however, appears very questionable, as the traces of such a sea-level ought to be more prevalent than they are, while as a rule in Ireland above the 350 feet contour-line the prevailing drifts are glacial or glacialoid. It seems, therefore, more natural to suppose, that while the great system of the Irish eskers was formed by marine action, small local systems or single eskers may be due to glaciers or some other cause. But I should not be surprised, if hereafter, when the Kaims of Scotland and the Asar of Scandinavia are worked out in their entirety, that the main systems are found to be of marine origin. Before concluding I should mention that from the true Hskers or Asar drift should be excluded the esker-like mounds or drumlins of Boulder-clay and Moraine drifts, that have by many eminent writers been confounded with the true Hsker-drift, as has been pointed out by the Rev. M. H. Close in his paper on the General Glaciation of Ireland. 1 General Glaciation of Ireland, Journ. Roy. Geol. Soc. Ireland, vol. 1. part iii. NOTICES OF MEMOTRS. On tHE ConpiTIons wHIcH DrtTerRMINE THE PRESENCE oR ABSENCE or AnimaL Lire on tHE Derp-Sea Botrom. By Dr. W. B. Carpenter, F.R.S.! HE foundation of Geological Science must be based upon a study of the changes at present going on upon the surface of the earth, including the depths of the sea. This is the distinctive feature of modern Geology. Until recently nothing was really known of the depths of the ocean; but, owing to improved methods of sound- ing, the bottom of the sea has been reached in so many places, that we may feel tolerably sure that its depth seldom exceeds four miles. Recent statements regarding an extraordinary depth off the coast of Japan are, most probably, due to an error similar to that which formerly represented the Straits of Gibraltar as unfathomable—an error caused by the carrying-out of the sounding-line in a strong surface-current. The general depth of the Atlantic does not exceed three miles, though, as an exception, the “Challenger” has recently attained 3800 fathoms in a hole 100 miles north of St. Thomas. As an additional proof that this was a true sounding, both the pro- tected thermometers came up crushed. The temperature of deep water has only lately been ascertained with accuracy, the earlier attempts having been vitiated by the error arising from pressure. Of the older attempts to ascertain the tem- perature of the deep strata, that devised by Lenz in the second voyage of Kotzebue, though fearfully laborious, gave results that corre- spond most closely with the “Challenger’s”; a fact in scientific annals which has been lately dug out by Prof. Prestwich, and by him brought to the notice of the lecturer, who found his own conclusions —made in entire ignorance of those of Lenz—thus singularly con- firmed. ‘The conclusions to be drawn from a study of these tem- peratures point towards a deep flow of polar water towards the Hquator, unrestricted, as regards the Atlantic, towards the south, but limited in the direction of the North Polar area, where there are two principal channels: the one between Greenland and Iceland, the other between the Faroe Islands and the 100-fathom line of North-west Hurope, on which platform the British Islands repose. This latter is the ‘‘ Lightning” channel, the scene of the lecturer’s first explorations, the study of which led to his view of the exist- ence of two opposite flows in the great oceanic area, quite irrespective of any one current. In this channel it was found that there was a superficial warm stream and a deep cold stream ; and that within a vertical space of 50 fathoms a most marked difference of temperature is suddenly encountered; whilst, as regards horizontal distance, tem- peratures of 294° F. and 48° F. have been obtained at the same depth in places not 20 miles apart. These facts mean that there are two distinct movements of water, just as a striking difference in the temperature of the atmosphere indicates a change of wind. Hence, speaking with reference to the “ Lightning” channel, it is clear that 1 Being the substance of a Lecture delivered before the Geologists’ Association, on Deeember 4th, 1874. Henry Woodward, Esq., F.R.S. , President, in the Chair. Dr. Carpenter's Lecture. 89 water much colder than the mean winter temperature of the latitude must have a northerly, whilst water that is warmer must have a southerly, source. In accordance with this we find that most of the animals of the cold area, such as the beautiful Comatula Eschrichtit, belong to the boreal fauna; whilst British species, such as the common Solaster papposa, which is dwarfed from the size of a plate to that of a crown-piece, are much stunted. Yet the fauna is abundant, as no temperature seems to prevent life, so long as sea-water is liquid. Pressure, though enormous, will not affect vital functions; since an animal, whose cavities contain air in aqueous solution only, can con- tract and expand just as well with a pressure of three tons to the square inch as it can on the surface. Not but what change of pres- sure, brought on by sudden removal, might produce some derange- ment. Neither temperature nor pressure, then, being directly of supreme importance, it is the supply of oxygen which has most influence on Animal Life in the deep seas. This is regulated by the general flow of water near the sea-bottom,—a flow not confined to any particular passage or area, but maintained by difference of specific gravity, produced by difference of temperature. As sea- water, in this respect differing from fresh-water, continues to increase in density down to its freezing-point, which is 27° F. if agitated, and 25° F. if still, the Polar column will outweigh the Equatorial column, and there will be a lateral outflow at the bottom towards the equa- torial area. This will cause a lowering of water in the polar area, and produce a surface-flow of water from the Equator towards the Poles. The two bottom-flows from either pole will thus meet near the Equator, and rising, will bring cold water nearer to the surface there than anywhere else, except where the surface itself is subjected to cold. In this way tke bottom-temperature of the South Atlantic would be lower than that of the North Atlantic, by reason of the less restricted body of the polar flow in the former. The tables given in the “Challenger’s” report confirm the conclusions thus arrived at. From these we find that the general temperature of the North Atlantic bottom is about 354° or 86° F., decreasing to 34° F. near St. Thomas, and under the Equator itself to 32°4° F., the lowest temperature of all. This section proves that the South Atlantic under-flow extends north of the Equator, as had been previously surmised by the lecturer. Only one section was made in the South Atlantic, and no temperatures lower than 334° F. were there obtained, the expedition not happening to hit upon the channel which brought in the water at 32°4° F. found under the Equator. Most remarkable of all is the line of 35° F. which can be traced across the South Atlantic and then gradually slopes down in the North Atlantic till it is lost. The temperature of the North Atlantic depths is pro- bably about 38° F. higher than in the South Atlantic. Off the coast of Lisbon, in lat. 38° N., the line of 40° F. is found at 700 to 800 fathoms; in lat. 22° N. at 700 fathoms; and on the Equator at 800 fathoms only, descending from a surface temperature of 75° F. The reason for this has been already shown to be the continual rise of the Polar under-flow towards the surface in the Hquatorial belt. 90 Notices of Memoirs— A further confirmation of these views is obtained from a comparison of specific gravities. The density (due to salinity) of surface-water increases from the poles to the tropics, while that of bottom-water in the tropics is nearly the same as in the polar area. Why then does the bottom-water of the tropics, being of lower salinity, under- lie the more saline strata? Because the density it lacks from its lower salinity is more than compensated by the lowness of its tem- perature. Passing, however, from either tropic towards the Equator, the salinity of surface-water is found to diminish, until its specific gravity is reduced from 1027°3 to 1026-4 or 1026-3, which is that of the polar under-flow. Lenz adduced the low salinity of the surface- water under the Equator as evidence of the rise of poiar water from the bottom, and showed that there is a band of water at the Equator colder than any to the north or south of it. The Oceanic Circulation thus produced brings every drop of water in turn to the surface, enabling it to part with carbonic acid and to absorb oxygen; this, then, is its importance to Animal Life. From the analysis of gases dissolved in the water of the oceanic area, it was found that, for 45 per cent. of carbonic acid, there was usually from 16 to 20 per cent. of oxygen—this being the result of a series of observations taken off Ireland and Scotland at various depths down to 2000 fathoms. This amount of oxygen is sufficient to support a large quantity of Animal Life, in spite of the, to air-breathers, fatal proportion of carbonic acid—if indeed the carbonic acid be not. in a liquefied, and thus perhaps more innocuous form. In the Mediterranean totally different conditions prevail. It was expected that a Tertiary fauna would be found at great depths, analogous to the Cretaceous-like fauna of the ocean outside. Instead of that, only a viscid mud, almost devoid of life, was brought up. The western basin has a depth of 1600 fathoms, the eastern basin one of 2000 fathoms ; the bottom temperature is nearly uniform at about 55°F., a great difference in thermal condition from the Atlantic. The reason is that the Mediterranean is cut off entirely from the polar under-flow, which, off Lisbon, produces a temperature of 40° F. at a depth of 700 fathoms, and 363° at 1500 fathoms. In the Mediterranean, on the other hand, we have a surface temperature from 60° to 70° F., which, in the first 100 fathoms, falls to 54° or 55° F., below which to the bottom, no matter at what depth, there is no change at all, but a slight variation according to latitude, due in part to the mean winter temperature of the locality. The whole of the lower portion, therefore, below the influence of the Gibraltar current, is a mere stagnant pool; and this is the explanation of the absence of Animal Life except in the shallows. The impalpable mud, which is slowly settling to the bottom, may also not be without its effect. This is the result of the attrition of soft Tertiary shores, and of the clay brought down by the Rhone into the western basin, and by the Nile into the eastern, the finer particles pervading the entire sea. Corals and Bivalves suffer from it especially, The per-centage of carbonic acid was found to be as high as 60, whilst that of oxygen was only 5; this is believed to be due to the organic matter, brought Dr. Carpenter’s Lecture. 91 down by the rivers, using up the oxygen. These unfavourable con- ditions are primarily due to deprivation of the general oceanic circulation, which maintains life at such great depths. There seems, however, to be a limit, in respect of depth, to the preservation of animal remains; due possibly, as conjectured by Prof. Thomson, to the solvent power of sea-water at pressures below 2200 fathoms. This may serve to explain the passage of true Globigerina ooze, first into grey ooze, poorer in calcareous matter, and finally at great depths into red ooze devoid of lime. Moreover, this dissolving of calcareous skeletons at great depths may serve to explain the pro- duction of Greensands, such as is now going on along the line of the Agulhas current. These consist largely of the internal casts of foraminifera, the sarcode of which has been replaced by glauco- nite). The importance of such facts to geologists is immense. It was the examination of a series of casts of similar bodies in a- green silicate, that, years ago, formed the foundation for the lecturer’s interpretation of the structure of Eozodn, where there is a replace- ment of its sarcodic body by a green silicate, viz. serpentine. If the sea-water, under this tremendous pressure, has dissolved away the shells of Foraminifera, after their sarcode has undergone the sub- stitution alluded to, a beautiful application of this kind of research to geological phenomena has been brought forward. Referring to Ed. Forbes’s limitation of marine life to 300 fathoms, the lecturer observed that the statement was true of the Aigean, as of the whole of the Mediterranean, where there is abundant life in the littoral zone, diminishing rapidly towards 250 fathoms, below which Animal Life is almost at zero. Finally it is not a limit of pressure, of heat, or even of food, but the limit of oxygenation, as determined by the presence or absence of a thermal circulation, which affects the life of animals. So that deposits forming in inland seas, excepting in the shallower portions, we must expect to be destitute of fossils. This is well illustrated by the Miocene strata of Malta, where certain coarsish beds, representing shallow water conditions, are full of fossils in a fine state of preservation ; whilst the very fine building stone, corresponding closely with the finest calcareous deposit of the Mediterranean, contains hardly any re- mains but such as would fall in from above, e.g. the teeth of sharks. This may explain the paucity of fossils in many strata, especially in the Red Sandstones of inland seas. Much depends upon the depth of the communication, supposing there to be one, with the oceanic circulation; and the level of this may be often inferred from a knowledge of the line of permanent temperature of such inland sea. To the general paucity of animal life under such conditions the Red Sea appears to be an exception, notwithstanding the shallow- ness of the Straits of Babelmandel. This is probably due to the absence of the sediment and oxidating matter of large rivers, and to the rocky nature of its shores, conditions which insure a clear water; whilst a certain circulation, producing oxygenation, is kept up to supply the enormous evaporation, which, if the Straits were closed, would desiccate the basin in three or four hundred years, 92 Reports and Proceedings—~ as 2a et VV Se Lronnarp unp Getnirz’s “Neuss JAHRBUCH FUR MINERALOGIE, GEOLOGIE UND PankontoLoeiz.” Jahrgang 1873. Hefte 1-9. HE many memoirs, and the numerous letters to the editors from active and well-known geologists and mineralogists, make this as rich as any former volume in original matter; whilst the bibliographical register of published memoirs, and the multitudinous abstracts of books and papers, treating of mineralogy, crystallography, mineral-chemistry, geology, and paleontology, render the Neues Jahr- buch indispensable to working geologists of every turn of mind, who wish to keep up with the current literature of their science. As original memoirs they will find, in Paleontology :—H. von Hichwald on the limbs of the Trilobite (with plate i.); H. B. Geinitz on the Cretaceous Inocerami; Zelger, Terebratula vulgaris in the Gypsi- ferous Keuper of France; H. Geinitz, Fossils (Insects and Plants) of the Bituminous Shale of the Lower Dyas (Permian) of Saxony (plate iii.) ; C. W. Giimbel on Coccoliths, Limestone, and Oolite ; Fr. Schmidt on Péeraspis Kneri; etc. In Geology :—Ferd. Romer’s tour in the Sierra Morena; H. Loretz on the Alpine Trias, etc., in South-Tyrol ; F. Sandberger on the Miocene formations in the Swiss and Swabian Jura; C. Naumann on the younger Gneiss near Frankenberg in Saxony (woodcuts) ; H. Laspeyres on the marine origin of the Rothliegende of Saxony; E. Cohen, Geological Notes on Griqualand, Transvaal, and the Diamond Diggings and Gold-fields of South Africa; R. Drasche, Geological Notes on Christiania and Spitzbergen; A. Jentzsch on the causes of the Glacial Period ; H. Hofer, the Ice-age in Mid-Carinthia; A. Streng, the Circulation of Matter in Nature; G. vom Rath, the Belluno Earthquake; Al. Stelzner’s tour in the Argentine Provinces San Juan and Mendoza; ete. In Petrology and Mineralogy :—G. vom Rath on the crystallo- graphic system of Leucite (plate ii.), and on the Sulphur-mines of Girgenti; A. von Lasaulx on Ardennite; A. Streng on some Por- phyrites; Th. Petersen, the Basalt and Hydrotachylyte near Darm- stadt; Burkart, some Tellurium Minerals from North America; C. Délten, the Tuff-rocks of South-Tyrol; Th. Scheerer, the Genesis - of Granulite; H. Mohl’s microscopic examination of some basalts of Baden (plate iv.); H. Bahren’s Spectrum of Opal (plate v.); A. Knop, Petroleum in the Odenwald ; and mineralogical papers by A. Frenzel, F. Wibel, H. Schroder, Kenngott, Ad. Pichler, Laspeyres, A. Knop, and others. ZT. RB. J, Ist OssvetsS)) VNINMD) S51 Ol\Or mappa. S- GrotogicaL Soctrty or Lonpon.— December 2, 1874.—John Evans, Hsq., F.R.S., President, in the Chair.—The following com- poe were read :— “On the Femur of Cryptosaurus humerus (Seeley), a Dinosaur ae the Oxford Clay of Great Gransden.” By Harry Govier Geological Society of London. 93 Seeley, Esq., F.L.S., F.G.S., Professor of Physical Geography in the Bedford College, London. The author described this femur as showing a slight forward bend in the lower third of the shaft, and as having the terminal portions wider in proportion to the length of the bone than in any described Dinosaurian genus. He pointed out its differences from the cor- responding bone in Megalosaurus, Iguanodon, and other genera. The length of the femur was stated to be about one foot. 2. “On the Succession of the Ancient Rocks in the vicinity of St. David’s, Pembrokeshire, with special. reference to those of the Arenig and Llandeilo groups and their fossil contents.” By Henry Hicks, F.G.S. In the first part of this paper the author described the general succession in the rocks in the neighbourhood of St. David’s from the base of the Cambrian to the top of the Tremadoc group, and showed that they there form an unbroken series. The only break or un- conformity recognized is at the base of the Cambrian series, where rocks of that age rest on the edges of beds belonging to a pre- Cambrian ridge. . In the second part the author gave a minute description of the rocks, comparing the Arenig and Llandeilo groups, as seen in Pem- brokeshire, with each other, and also with those known in other Welsh areas. Each group he divided into three subgroups, chiefly by the fossil zones found-in them. 1. The Lower Arenig was stated to consist of a series of black slates about 1000 feet thick, and to be characterized chiefly by a great abundance of dendroid graptolites. 2. Middle Arenig. A series of flags and slates, about 1500 feet thick, and with the following fossils :—Ogygia scutatrix, O. pel- tata, Ampyx Saltert, etc. 3. Upper Arenig. A series of slates, about 1500 feet in thick- ness, only recently worked out, and found to contain a large number of new and very interesting fossils belonging to the following genera: viz. Illenus, Illenopsis, Placoparia, Bar- randia, etc. i 4. Lower Llandeilo. A series of slates and interbedded ash, equivalent to the lowest beds in the Llandeilo and Builth dis- tricts, and containing species of Atglina, Ogygia, Trinucleus, and the well-known graptolites Didymograptus Murchisoni and Diplograptus foliaceus, ete. 5. Middle Llandeilo. Calcareous slates and flags, with the fossils Asaphus tyrannus, Trinucleus Lloydit, Calymene cambrensis, etc. 6. Upper Llandeilo. Black slates and flags, with the fossils Ogygia Buchii, Trinucleus fimbriatus, ete. The Arenig series was first recognized in North Wales by Prof. Sedgwick about the year 1843, and was then discussed by him in papers presented to the Society. The Llandeilo series was discovered by Sir R. Murchison previously in the Llandeilo district, but its posi- tion in the succession was not made out until about 1844. The Geo- 94 Reports and Proceedings. logical Survey have invariably included the Arenig in the Llandeilo group; but it was now shown that this occurred entirely from a mistaken idea as to the relative position of the two series, which were now shown to be entirely distinct groups, the equivalents of both groups being present in Carnarvonshire, Shropshire, and Pem- brokeshire, but the Llandeilo group only of the two being developed in Carmarthenshire. The lines of division in the series were said to be strongest at the top of the Menevian group and at the top of the Tremadoc group, these lines being paleontological breaks only, and not the result of unconformities in the strata. Discuss1on.—Professor Ramsay complimented the author on having brought forward a paper so well worked out. He gave an account of his own early geological work in Wales, and stated that he had mapped the rocks referred to by Mr. Hicks in 1841. He differed from the author in believing his supposed Laurentian rocks to be igneous. They were metamorphosed Cambrian deposits, which had lost all traces of their aqueous origin. In 1841, no fossils had been found below the Llandeilo Flags in any part of the series described by Mr. Hicks, and thus there was no ground for establishing those palzeontological divisions in the series which were indicated in the present paper. He stated that he traced the line between the blue flags and the Cambrian slates, and believed that it would show an unconformity between the Tremadoc slates and the Lower Llandeilo. Prof. Hughes observed that the fossils by which the rocks under discussion were subdivided did not occur all through the several groups, but only in widely separated zones ; and that between those zones sometimes one line and sometimes another had been taken as the arbitrary boundary, often to be shifted in conse- quence of the discovery of other fossiliferous bands. The line referred to by Prof. Ramsay, as that which he was tracing in North Wales for the base of his Llandeilo, was a most useful line to draw, as helping to trace horizons, but was not shown to be coincident with any great break in succession. The Silurian system had not and, after several changes, has not for its upper boundary a line representing any break in the continuity of deposition. Nor had it at first nor has it now, after much modification, any well-defined natural boundary for its base-line. The only break in it is that which occurs at the base of the May Hill Sandstone, and that was unrecognized till pointed out by Prof. Sedgwick, many years after the publication of the “‘ Silurian System,” the author of which, seeing that his system had no base on which to rest, took in group after group of the underlying series, and to justify himself had to prove at each step that, as yet, no break had been found in the series ; till at length he got down to the lowest Cambrian, part of which he included in his Primordial Silurian. It was now well known, and that chiefly through the labours of Mr. Hicks, that no strong line could be drawn there, and we must therefore take it down to the bottom of the Cambrian conglomerate, or up to the base of the May Hill Sandstone. Between these horizons lie the Cambrian rocks of Prof. Sedgwick, a well-defined natural group and an ancient name, which, following the true principles of classification and justice in our nomenclature, we must adopt. Mr. Etheridge remarked that several species pass up from the Tremadoc into the Llandeilo, and that the line between the Tremadoc and the Llandeilo of Sedgwick was not settled. In all cases of this kind stratigraphical or paleeonto- logical evidence alone was not sufficient, the two required to be concordant. He entered at some length into the paleontological statistics of the deposits under discussion, and dwelt especially on the fact that of 70 species of fossils found in the Tremadoc, only four pass up into the Arenig. The break at the top of the Tremadoc was thus palzeontologically of great importance, although not apparent stratigraphically. Hardly any of the Lower Llandeilo (or Arenig) species agree with those of the Llandeilo Flags. The species at the top of the Stiper have a peculiar facies of their own, and would not be recognized as Arenig. Prof. Seeley said that the subdivisions of the Cambrian series of Sedgwick were based solely on paleontological evidence, and that to the physical geologist the Correspondence. 95 deposits formed a single series, which could be subdivided upon stratigraphical grounds. But although there was no evidence of unconformity between the strata, he thought that the fact of different groups of fossils succeeding each other in the same area showed that those groups existed in neighbouring seas, and had been driven by upheaval of the sea-bottom on which they lived, into the region in which they are found. Hence he maintained that a change in the forms of life is evidence of unconformity in an adjoining area. Mr. Maw remarked that under the Cambrian rocks at Llanberis there are un- conformable beds, which may be the equivalents of the so-called Greenstones of St. David’s. Mr. Hicks admitted that the subdivisions at present in use may need to be modified. He thought that the greatest break is between the Menevian and the Lingula Flags, few species passing from one to the other. He regarded the upper and lower portions of the Tremadoc as really distinct. CORRESPONDENCE. ee VOLCANIC ROCKS OF THE LAKE-COUNTRY. Srr,—As much interest attaches to the question of the relation of the volcanic rocks of the Lake-country (the Green Slate and Porphyry series) to the older Skiddaw Slates, and as one of us formerly expressed an opinion on the subject contrary to what the subsequent researches of the Geological Survey have made out, it may interest some of your readers to learn that we have lately discovered in Swindale, near Shap, beds of volcanic ash of the Green Slate and Porphyry series clearly interbedded with the Skiddaw Slates, similar to the case discovered by Mr. Aveline near Black Comb. J. R. Daxyns, Kendal, J. Cuirton Warp, Keswick. DEEP BORING IN PRUSSIA. Str,—I send you some particulars, with which I have lately been favoured by Professor A. von Koenen, of Marburg, respecting the deep boring made by the Prussian Government Engineers at Speren- berg, about 25 miles south of Berlin, and noticed by your cor- respondent J. P. at page 48 of the Grontocican Macazine for January. The boring for the first 956 feet (12974 English feet) vi was made by manual labour, at a cost of about £1600. Several accidents having happened, the borehole was then lined for a depth of 85 feet (1154 English feet) with tubes of 15 inches diameter; beyond that, to the depth of 100 feet (135 English feet), with 14-inch tubes; and then to 3634 feet (4934 English feet) with tubes of 125 inches diameter. The length of time occupied in the above-mentioned work was fifteen months—comprised between May, 1867, and July, 1868. From the depth of 956 feet (12974 English feet), for the remain- ing distance, the boring was carried on by means of a steam-engine. The length of time consumed in sinking this additional 3095 feet (4255 feet English), comprised between January, 1869, and the 15th September, 1871, was about 314 months, or 2 years and 7 months; during which interval several accidents occurred. 96 Correspondence and Miscellaneous.” The total expenditure upon the whole boring, 4051 feet (5570 English feet), both by manual labour and by steam power, was about £8717 14s.—making the average cost for every Prussian foot in depth about 2 guineas, or £1 11s. 4d. per English foot. The whole time spent on the work was 514 months, or 4 years and 34 months; but as there was an interval of 5 months, between July, 1868, and January 1871, during which period the boring Operations were suspended, the actual number of working months becomes reduced to 464. ~ The process of boring throughout was by percussion borers worked by rods ; and the rocks bored through belonged to the Triassic series. The progress of the work would have been much greater but for the accidents which took place, and for the delays which were caused by the observations that were made as to the increase of the tempera- ture of the earth in depth, etc. The measurements were taken in Prussian feet; these have been reduced to English feet—the Prussian foot being 12:357 English inches. A memoir (“Die Tiefbohrung zu Sperenberg”’) on the subject of this interesting undertaking will be found in the “ Zeitschrift fiir das Berg- Hiitten- und Salinen-Wesen in dem Preussischen Staate,”’ Band xx. 1872. H. W. Bristow. 28, JERMYN STREET, January, 1875. THE GREAT RHATIC BONE-BED NEAR FROME. Sir,—To those of your readers who make a special study of the Rheetic beds, it may be of interest-to know that the great Bone-bed, situate in the Black Shales of the above series, and replete with its usual remains, has been met with at the depth of 310 feet, in a pit, at present being sunk by James Oxley, Hsq., of Frome, to the Lower Series of Coals of the Somersetshire basin, about two miles N.W. of Frome, and on the §.H. flank of the Mendip Hills. AuFrep ©, CRUTWELL. West Hit, Frome, 15 Jan. 1875. MISCHUOUAN HOUS. ArtestAn WeELL aT Torquay.—The Diamond Boring Company are sinking an artesian well on the premises of the Torquay Brewing Company, in Fleet-street, Torquay. About 90 feet of solid limestone (Devonian) has been penetrated. It is anticipated that an abundant supply of water will be reached at a depth of about 200 feet; but although this may be regarded as very problematical, there is no doubt that if the work proceeds a very interesting geological section will be obtained. THE GEOLOGICAL MAGAZINE. NEW, SERIES] DEGADE II. VOL, (II. No. III—MARCH, 1875. ORDG- EIN AT AR wPECGam Ss: ————— I.—“‘ Unirormity” AND “ VULCANICITY.” By the Rev. O. Fisuer, M.A., F.G.S. OME geologists there are who are prevented from carrying out S on an extended scale observations in the field. They may well envy those who have the strength, leisure, freedom from local duties, and means to travel. Such accurate descriptions as they receive from a pen like Mr. Judd’s, enable them to see with other eyes, and to test the theories which they spin out of their brains by wider information. They must accept their position, and either speculate, or do nothing, in their favourite science. Happily Mr. Judd admits that speculation has its value, and Mr. Clifton Ward is of the same opinion. But we are warned not to “abandon those safer methods of inquiry based on the doctrine of Uniformity,” nor “to revert to the earlier methods—in effect, to substitute cosmogony for geology.’’! What is meant by the doctrine of Uniformity? If it be simply that like forces have produced like results in all former times to what they produce at present,—in other words, that the laws of nature have never changed,—then no doctrine can be more certain. But if it teaches that “all things continue as they were from the beginning of the creation,”—in other words, that the forces of nature act upon matter which has always been in the same condition as at present,—then I submit that the doctrine of Uniformity itself ought to be “abandoned.” To apply the principle to Vulcanology : “It would be very wonderful, but not an incredible result, that volcanic action has never been more violent on the whole than during the last two or three centuries ; but it is as certain that there is now less volcanic energy in the whole earth, than there was a thousand years ago, as it is that there is less gunpowder in a “ Monitor,” after she has been seen to discharge shot and shell, whether at a nearly equable rate or not, for five hours without receiving fresh supplies, than there was at the beginning of the action.” ? : If the doctrine of Uniformity in this sense be untenable in its application to the condition of the earth in all past time, then we are necessarily led backwards to cosmogony; and I cannot see why our science should not be permitted to connect itself with cosmogony at the one extremity, as it has lately become firmly united to archeology at the other. “The earlier methods” led often to 1 Mr. Judd, On Volcanos, Grou. Mac. Dee. IT. Vol. II. p. 3. * Thomson, On the Secular Cooling of the Harth, Nat. Phil. p. 714. ° DECADE Il.—YOL. I.—NO. Il, il 98 ev. O. Fisher—“ Uniformity” and “ Vulcanicity.” fallacious results, because the facts of Geology were then little known. Speculation preceded observation. But we have now immense stores of observations, by which speculation may be guided ; and if speculators are not so perfectly acquainted with these as observers are, the latter can check them, and they are, as Mr. Ward has proved himself, fully equal to the task. To follow speculation to its legitimate conclusions, some know- ledge of mathematics, physics, and chemistry are needed, as Mr. Mallet truly tells us. The philosophical method appears to be, in Geology as in other kindred sciences, to start with a probable hypothesis, and, following it to its necessary consequences, to in- quire whether these harmonize with observed facts. It is here that mathematics finds its proper field. That science is a mode of reasoning, unerring in its methods, but wholly dependent for the truth of its results upon the premisses, assumptions, and limitations, according to which the inquiry is conducted. If the result turns out to be erroneous, it is not the method which ought to bear the blame, but the original hypotheses. Mr. Mallet has lately cast down his gage with so loud a ring that he has arrested general attention, and his theory of Vulcanicity is so ingenious and so bold, that it appears to have thrown many minds into one of two states, which are, either of them, unfavourable to calm inquiry. Those whose views are called in question reply in a spirit as eager as that in which they have been challenged ; while others, charmed with the novelty and seeming simplicity of the theory, embrace it as of course. For my own part I cannot say that my mind is at all made up upon the subject; and it needs more study than I have been able to give, before I can persuade myself that I even understand his argument. But I am free to allow that I consider Mr. Mallet’s paper in the Philosophical Transactions an important work. The mere experiments upon the resistance which different rocks offer to crushing, the elaborate tables founded upon them, the investigations on the fusion of slags, and their contraction in cooling, with the tabulated results—all these, apart from any conclusions drawn from them, are of very great value. Whether the theory of Vulcanicity, which the author builds upon these experi- ments, is their legitimate outcome, is the point really in question. Yet as far as I have seen, it has been barely touched by his critics. The question when simply stated appears to be this. Is the super- heated interior of the earth so deeply buried at the present time as to render it highly improbable that volcanos should be channels of communication between it and the surface? Mr. Mallet believes that it is too deeply buried, and suggests a secondary cause, due ultimately, nevertheless, to the presence of a heated interior, and so accounts for volcanic action. Mr. Scrope, on the other hand, in- quires, why, admitting a heated interior, should it be sought to bring in a secondary cause in order to account for the superficial manifestations of its presence. This query is clearly pertinent. Yet, for all that, it may have to be answered that such a secondary cause is necessary. So the question might be asked and answered, DECADE II. Vot. II. Pu. VII. NEw SERIES. GEOL. MAG. 1875. Mie 1 Va i ) ith ‘ f i Ht hg i a fat a | : ih Mega ane Hi iu i n ed the Fossa Anticcha. with two of its craters h. Vulcanello, d. Small crater, call Great crater. C. with the “‘ Fabbrica”’ near it. { -streams proceeding from Vulcanello. 7. Porto di Levante. 7. Porto di Ponente. The Faraglioni, 6. Highest point of the central cone. g. to the crater. rings and the central cone. #. Lava 775. Jf. Road leading in CRATER-RINGS IN THE DISTANCE, AS SEEN FROM ABOVE PUNTA DELLA CREPAZZA, IN LIPARI, z. The Atrio between the outer crater- gs culminating in Monte Saraceno. e. Obsidian lava-stream of 1 SKETCH OF THE GREAT CENTRAL CONE OF VULCANO, WITH VULCANELLO IN THE FOREGROUND, AND THE OLDER ENCIRCLING seen. aa. Outer crater-rin J. W. Judd—On Volcanos, 99 Why look to a secondary cause to account for the fire which flies from the wheel of a railway carriage, when the brake is applied, knowing that a hot furnace is burning in the engine. The two cases are more nearly parallel than they appear. Before the matter in dispute can be settled, Mr. Mallet’s theory needs to be criticized closely from his own point of view, to inquire whether he is justified in claiming for it a capability for producing the actual phenomena of vulcanicity, both present and past. And even if it should turn out to be capable of that, Mr. Scrope’s view may still be concurrently true, unless it can be shown that no direct communication can exist between the surface of the globe and its heated interior. That part of Mr. Mallet’s conclusions which Mr. Ward refutes does not appear to be of the essence of the question. Indeed a convert to his main theory might hold quite different, opinions from his with respect to the sequence and formation of some of the great features of the globe. Ti.—Conrtrisutions To THE STuDY OF VOLCANOS. By J. W. Jupp, F.G.S. (Continued from page 70.) Tae Lipari IsLanps.— VULCANO. (PLATE VIL.) During the earliest periods concerning which we have historical records in Southern Europe, Vesuvius was certainly inactive, its true character, indeed, long remaining wholly unsuspected ; nor do the eruptions of Htna at this epoch appear to have been of such a character as to have powerfully arrested the attention and excited the imaginations of the oldest inhabitants of the district. Far otherwise was it, however, with the volcanos of the Lipari Islands ; in these the manifestations of igneous activity had been so constant and striking, that priests, poets, and philosophers had successively associated the locality with their most marvellous stories. Identified in the older mythologies with the forge of Vulcan and, the workshop of the Cyclops, it is not surprising to find the super- stitious mariners applying to the southern and more violently active of the Lipari volcanos the name of Hiera—or the Sacred Isle. And its vast crater, presenting by day bellowing fumaroles, and by night glowing fires, is not inappropriately selected by Virgil as the scene of the forging of the armour of Aineas. In later times, when fear and fancy had begun to give place to curiosity, the historians, geographers, and philosophers of Rome gave more sober and accurate accounts of the phenomena of this island; and its later name of “ Vulcano”’ or “Volcano” has gradually come to be applied to all mountains where igneous forces are similarly displayed. Nor, as we shall attempt to show in this chapter. is this voleano unworthy of the distinction which it thus accidentally acquired—that of serving as the prototype of all the members of its class. Observations, carried on during longer periods, and over far larger portions of the earth’s surface, have made us acquainted 100 J. W. Judd—On Volcanos. with many grander volcanic piles and with more striking manifes- tations of igneous action; yet it may, perhaps, be doubted whether in any of these the nature, products, and causes of the phenomena displayed can be so advantageously studied as in Vulcano. In seeking to sketch the early history of this volcano it would be a hopeless task to attempt the separation of truth from its embellish- ments in the legendary stories of the oldest classical writers; yet we may at least accept the traditions associated with Vulcano as proving that, during the earliest periods of the occupation of the district, its outbursts had been both frequent in their occurrence and striking in their characters. As we come to later times, however, more trustworthy statements concerning its general condition and its paroxysmal displays of violence are found, in the writings both of geographers and historians. Thucydides, in the fifth century before Christ, speaks of Vulcano as throwing out a considerable smoke by day and flame by night. The appearance of flames was doubtless due, as in all volcanic eruptions, to the reflexion of glowing surfaces of lava in the crater from the clouds of ejected matter rising above it, or to fragments of incandescent solid or liquid matter mingled with the latter. In the next century, Aristotle records a grand eruption of Vulcano, during which a new hill was formed; the quantity of ashes thrown out being so great as to entirely cover the city of Lipari (six miles distant from the volcano), and to extend to several of the towns of - Italy. This eruption had not entirely ceased at the time when Aristotle wrote. Callias, writing in the third century before Christ, describes Vulcano as possessing two craters; one of which was nearly 2000 feet in circumference, and threw out burning stones of prodigious size, with a noise that could be heard at a distance of more than fifty miles. ‘ In the next century a very remarkable and important eruption took place, during which a new island gradually rose above the sea- level, great numbers of fish being killed. This account is usually interpreted as applying to the formation of Vulcanello. Posidonius, Pliny, and other writers who record this interesting event, are not, however, agreed as to the exact year in which it took place. From an account of Vulcano, written in this same century by Polybius, and preserved by Strabo, the mountain appears to have had three craters, two tolerably well preserved, and one in part fallen in. The larger crater was round, and about 1000 yards in circuit; its interior was funnel-shaped, the bottom of it being only about 50 feet in diameter, and 600 feet above the sea-level. It is clear that these observations must have been made during a period of inactivity in the volcano. Diodorus, who was a native of Sicily, speaks of Vulcano in his time, namely the century before the Christian era, as throwing out burning stones, like Stromboli and Etna. Strabo, who wrote just before the time of Christ, tells us that the three openings or craters of Vulcano ejected ignited matters, that filled up a part of the sea to Je W. Judd—On Volcanos. 101 a considerable extent. We may also infer from the account of Strabo that Vulcano ejected lava in his time. Lucilius Junior, Pliny, and Mela Pomponius, all of them writing in the first century of the Christian era, speak of Vulcano as being in a state of activity. As soon, however, as we lose the guidance of the classical authors, the history of Vulcano becomes involved in the greatest obscurity. The inhabitants of the Lipari Islands suffered greatly from the invasions of pirates and slave-hunters, a circumstance of which the name of “ Monte della Guardia,” applied to the highest summits in almost all of the islands, furnishes a melancholy testimony. It is not therefore surprising to find that the Liparotes gradually acquired a ferocity of disposition, which caused their inhospitable shores to be shunned by mariners during the lawless medizval times. So late, indeed, as the last century, the evil reputation of the islanders was such as to prevent travellers from venturing among them ; and it was not until the Mediterranean was cleared of the Barbary pirates, at the commencement of the present century, that these islands could _be visited with perfect safety. The long period of obscurity, to. which we have alluded, is only broken by a brief reference of Husebius, and another by Orosius, in the fifth century ; and by the following, perhaps legendary, account : In a biography of St. Willebald, who is said to have lived between the years 701 and 786, there occurs the following passage :—“ From Reggio St. Willebald sailed to see Vulcano, one of the Lipari Islands, then in a state of eruption. The saint wished to obtain a view of the boiling crater, called the ‘infernum of Theodoric,’ but they could not climb the mountain from the depth of the ashes and scorie. So they contented themselves with a view of the flames, as they rose with a roaring like thunder, and the vast column of smoke ascending from the pit.” It would seem from this passage that, if Vulcano had lost the ‘reputation of being the forge of Vulcan, its state of activity and the terrors which it inspired during the Dark Ages were such as to cause it to be identified with a still more dreadful place. -Brydone, visiting Htna in 1770, found the Sicilian peasants holding the belief that its crater was the place of confinement for poor Anne Boleyn, who had exercised so unfortunate an influence on the “ Defender of the Faith.” Vulcano appears, in still earlier times, to have been fixed upon as the place of torture for an Arian emperor. The modern history of Vulcano commences with the accounts given by Fazello, who was a native of Sicily, and lived between the years 1490 and 1570. He states that on the 5th of February, 1444, a great eruption occurred, which shook all Sicily, and alarmed the coast of Italy as far as Naples; the sea is declared to have boiled all around the island, and rocks of vast size to have heen discharged from the crater. A number of submarine eruptions are said to have taken place all round the island, fire and smoke rising above the waves; and as the result of these the navigation around the island was totally changed, rocks appearing where there was before deep 102 J. W. Judd—On Volcanos. water, and many of the straits and shallows being completely filled up. At a later period, Fazello appears to have himself visited the island, and relates that the mountain was in a state of continual conflagration. He states that from its gulf (crater), which lay in the middle of the island, a cloud of thick smoke continually issued, while through the fissures of the stones and narrow apertures a pale flame arose in the midst of a dark cloud. It would thus appear that, after the grand outburst in the fifteenth century, the volcano relapsed into a condition similar to that which it now presents. Another interesting fact recorded by Fazello is, that in his time Vulcanello was still a distinct island, separated from Vulcano by a narrow channel, in which ships could lie in safety; but that this channel was subsequently filled up by new eruptions. Fresh outbursts of Vulcano appear to have occurred early in the seventeenth century, for Cluverius states that, standing on the opposite shores of Sicily, he could perceive fire and dark smoke arising from the mountain. Father Bartoli, who visited the island in 1646, relates that “it contained a deep gulf, entirely in a state of conflagration within,. and, in a small degree, to be compared to Etna; and from its mouth a copious smoke continually exhaled.” This appears to have been a time of comparative rest in the volcano. In 1727, however, when M. d’Orville visited the island, the voleano was certainly in a much more active state. It had then two distinct craters, each of which was situated at the summit of an eminence. From the most southern of these,. which was about a mile and a half in circuit, there was ejected, besides “flame” and smoke, ignited stones; and its roaring was not less than the loudest thunder. From the bottom of the gulf rose a small hill about 200 feet lower than the top of the crater, and from this hill, which was entirely covered with “sulphur” and dirty corroded stones, fiery vapours exhaled in every part. M. d’Orville had, however, scarcely reached the edge of this “ burning furnace,” when he was obliged to retire precipitately. The second crater lay towards the northward of the other. Its “conflagrations’’ were more frequent and ardent; and its ejections of stones, mixed with ashes and an extremely black smoke, almost continual. M. d’Orville further relates that the noise of this vol- canic island was heard for many miles; and was so loud at Lipari (six miles away) that he could not sleep the whole night that he remained there. This very clear and explicit account of the state of Vulcano is of great interest to us, exhibiting as it does a distinct image of the two cones and craters upon the great line of subterranean fissure and the rise of an internal cone from the bottom of one of them. More than sixty years after, Spallanzani found that some of the oldest of the inhabitants of Lipari still retained an imperfect recollection of the existence of the two craters. At what period these were obliterated and the single cone formed, we have not the means of exactly determining. It is clear that J. W. Judd—On Volcanos. 1038 between the years 1730 and 1740 the volcano was in a state of almost continual eruption; the Abbe Don Ignazio Rossi, a native of the island of Lipari, kept a diary of observations made during these years, which was published in 1761 by Signor Don Salvadore Papacuri of Messina. Rossi speaks of an almost continual discharge of ashes and smoke taking place, sometimes rising in clouds of great density, and at other times accompanied by explosions of great vio- lence, earthquake shocks and loud roarings. He believed from his observations that the changes in the condition of the volcano were related, in some way or other, to the variations in the state of the atmosphere and the directions from which the wind blew. This question we shall have occasion to refer to more particularly here- after. Deville speaks of violent eruptions having taken place in 1731 and 1789. That a series of almost continual ejections during more than ten years should have greatly affected the form of the cone and crater of Vulcano is no more than might have been expected. Fortunately, we have in the “Travels” of M. W. de Luc an account of the state of the volcano in 1757. He appears to have been the first writer on the island who ventured to enter the crater. On the 30th of March, in the year mentioned, he managed to reach the bottom of the crater by a narrow passage (probably a great fissure rent in the side of the cone, like that produced in Vesuvius in 1872), which afforded him admission to the interior, but at great risk of being suffocated by the dense sulphurous fumes that enveloped him. His guide, a native of Lipari, refused to accompany him. He describes the bottom as being very rugged and uneven, with a number of apertures, from some of which issued a “ strong wind,” and from others sulphurous vapours, while an abyss, 60 paces in circuit, near one of the sides, gave off a column of smoke 15 or 18 feet in dia- meter, with a roaring sound “like that of the vapour of boiling ‘water, when it escapes from a vessel not closely covered.” ‘The floor of the crater is described as oval in form, with a longer diameter of 800 to 900 paces, and a shorter of 500 to 600; but the sides of the ’ erater, which are spoken of as perpendicular, are estimated to have been only from 150 to 200 feet high. We may probably infer, therefore, that the crater had become, in 1757, almost filled up by the fragmentary ejections of the long period of constant activity. M. de Luc also informs us that the sea around the island had a yellow colour in places, and in others emitted fumes, the heat at the latter places being intolerable, and the fish of the sea killed. A little above the sea-level he found springs of warm water issuing from the beach and flowing into the sea; and around these spots the surface of the latter was covered with dead fish. It seems clear, _therefore, that the fumaroles on the outside and on the submerged portions of the volcano, though similar in character, were more numerous and violent in their action than at the present day. ‘This is, of course, no more than might be expected so shortly after a prolonged series of violent eruptions. In 1768, Sir William Hamilton passed by Vulcano, but did not 104 * J. W. Judd—On Volcanos. land on it; the voleano appears at this time to have lapsed into a state of quietness, for he compares it to the Solfatara of Naples, and his artist, Signor Fabris, gives a drawing, in which clouds of vapour are represented as steadily rising from it, in much the same manner as at the present day. Brydone assures us that in 1770, when he watched the island for a whole night, neither Vulcano nor Vulcanello emitted any glow of light, but only threw out volumes of white “smoke.” In 1771, according to Deville, and again in 1775, as recorded by Dolomieu, great eruptions of Vulcano took place. During the latter the great stream of obsidian on the north side of the cone is said to have been produced. Spallanzani, it is true, has thrown doubt on this statement of Dolomieu, on the ground that he could obtain no confirmation of the fact from the inhabitants of Lipari; it must be remembered, however, that Dolomieu visited Vulcano only six years after the eruption took place, while Spallanzani was not there till seven years later. It seems to me extremely probable that the filling up of the crater, which had made so much progress at the time of M. de Luc’s visit in 1757, had probably continued till 1775, when the liquid lava was able to overflow the crater-rim. Dolomieu’s observations on the state of the crater in 1781 seem to be quite in accord with this view. The sides were then so steep that he was unable to enter the crater, but by means of a telescope he could distinguish two small pools, into which large stones slowly sank when rolled from the edge of the crater. That these were full of incandescent lava is proved by a fact that Dolomieu records, namely, that the vapours of Vulcano were by night resplendent with placid flames (evidently the reflected glow of a surface of lava like that of Stromboli) that rose above the mountain and diffused their light to some distance. The great Calabrian earthquake of 1783, which was violently felt in all the Lipari islands, does not appear to have been attended by any change in the condition of Vulcano. But in March, 1786, according to the unanimous testimony of all the islanders, as care- fully collected by Spallanzani only two years afterwards, a most violent eruption took place. -At first a series of subterranean thunderings and roarings were heard over the whole of the islands, but accompanied in Vulcano by frequent concussions and violent shocks. Then the crater threw out a prodigious quantity of sand mixed with immense volumes of smoke and “fire” (incandescent matter). This eruption continued for fifteen days, and so great was the quantity of sand ejected, that the circumjacent places were entirely covered with it to a considerable depth. This eruption in its characters and effects may be justly compared with the Vesuvian outburst of 1822, which was witnessed by Mr. Scrope and so graphically described by him. Two years after this great outburst of Vulcano, Spallanzani, to whose intelligent observations on this and other volcanos geologists are so greatly indebted, visited the island. Such was the terror inspired by the recent eruption, that he could not induce any J. W. Judd—On Volcanos. — 105 Liparote to accompany him into the crater. A resolute Calabrian, banished for his crimes to Lipari, was at last prevailed upon, by the offer of a large reward, to make the venture. Spallanzani describes the bottom of the crater as being oval in form, perhaps one-third of a mile in circumference, and covered with sand like the sides. The walls were almost perpendicular, and so high that Spallanzani judged them to exceed a quarter ofa mile. It was only on the south-east side of the crater, where some of the materials had slipped from the sides, and formed a sloping talus, that access was possible. In the centre of the bottom rose a small hill, about 45 feet in diameter, from every part of which a dense white smoke arose, its surface being encrusted with salts. On the west side of the crater- floor a mouth 30 feet in circumference gave off a column of dense white smoke with a loud roaring noise, and the explosions from this aperture had evidently blown away part of the adjacent crater-wall. Such was the heat and sulphurous stench proceeding from this ‘‘bocca” _ that it was impossible to approach it closely ; its sides, however, could be seen to be coated with stalactites composed of sulphur and various salts. A spring of water, also depositing stalactites, was seen issuing ata height of about eight feet from the floor of the crater. All over the interior of the crater, and at many points around it, innumerable fumaroles poured forth jets of vapour, and in many places it was only necessary to stamp with the foot in order to pro- duce fresh ones. The gas issuing from these apertures, the sides of which were intensely hot, sometimes extinguished a candle brought near them; but at other times the gas itself became ignited, and burned for several minutes with a bluish-red flame. At night several bluish flames could be seen rising from the bottom to the height of half a foot or sometimes higher; and these were most numerous and conspicuous in the central eminence. Spallanzani describes the heat at the bottom as being so great as to burn his feet, causing him to seek refuge on the large blocks of lava scattered about. The odour of sulphuretted hydrogen was so strong as greatly to affect his respiration; it was in consequence very difficult to walk round the crater, and quite impossible to cross it near the middle. The action of the acid vapours on the fragments of glassy rock was very marked; and in one case Spallanzani was able to observe the commencement of change produced in a piece of black lava, which he jammed into the mouth of a fumarole and re- examined after the lapse of. 32 days. These clear descriptions of the great Italian philosopher enable us to refer without doubt to the grand eruption of 1786 the pro- duction of the existing vast crater of Vulcano; and this crater, it is probable, did not undergo any material changes, except in the number, position, products, and violence of discharge in its fumaroles, till the eruptions of 1873-4. That the signs of activity should have been much more marked two years after the great eruption than they afterwards became is no more than might have been expected. The amount of igneous action going on in 1788 was sufficient to cause an obscure red glow oyer the crater by night. ? 106 J. W. Judd—On Volcanos. The southern and extinct portions of the island of Vulcano were inhabited and cultivated at a very early period. But during many of the more violent eruptions, which shook the whole island and covered it with thick deposits of ashes, the inhabitants would doubt- less be driven away. This was certainly the case during the violent outbursts of the 18th century, when the island appears to have been wholly uninhabitable. At what period the people of Lipari found that the neighbouring volcano constituted, in its abundant chemical deposits, a great source of wealth, is not known. It is said, however, that at one time the collecting of these valuable products was abandoned, on account of the alleged injury done to the vines of Lipari by the sulphurous vapours. On the work being resumed by permission of the King of Sicily, furnaces for the purification of the sulphur are said to have been established in the Fossa Anticcha. The great accession of activity beneath the mountain, which heralded the series of outbursts of last century, made itself felt by an increase of heat in the soil, and abundant disengagements of suffocating gases, and this once more caused the cessation of the industry. As the terrors produced by the grand eruption of 1786 died away, and the crater began to gradually cool down, the inhabitants regained boldness sufficient to enable them again to visit the crater habitually, and at last to form habitations for themselves near the tempting but dangerous source of wealth, by excavating miserable homes in the old tuff cone of the Faraglione. After the work of extracting the various chemical products had been carried on in a desultory manner for a considerable time, the crater was purchased a few years ago by a Glasgow firm for the sum of £8000, and regular chemical works established in the island. The collecting and preparation of the materials for exportation now em- ploys about a hundred workmen, the whole of whom are Italians; but the necessary capital and machinery for carrying on the operations are supplied from this country. Since the last grand eruption, and the lapse of the volcano into comparative tranquillity, its crater has been visited and examined by many geologists. Dr. Daubeny, who visited the island in 1824, observes : ‘The operations of this voleano appear to be going on with much greater vigour than those of the Solfatara, and exhibit, perhaps, the nearest approximation to a state of activity during which a descent into the crater would have been practicable. “Nor can I imagine a spectacle of more solemn grandeur than that presented by its interior, or conceive a spot better calculated to excite in a superstitious age that religious awe which caused the island to be considered sacred to Vulcan, and the various caverns below as the peculiar residence of the god. “To me, I confess, the united effect of the silence and solitude of the spot, the depth of the internal cavity, its precipitous and over- hanging sides, and the dense sulphurous smoke, which, issuing from all the crevices, throws a gloom over every object, proved more im- pressive than the view of the reiterated explosions of Stromboli, contemplated from a distance, and in open day.” J. W. Judd—On Volcanos. 107 At the present time the well-made road, leading by a series of zig- zags to the summit of the mountain, and the exceilent viaduct over which this road is conducted into the interior—the trains of laden asses and mules passing along the same—and the groups of busy workmen scattered over the floor of this strange workshop, per- haps detract somewhat from the feeling. of awe which the place would naturally inspire. What has been lost by the lover of the picturesque and wonderful, however, has been gained by the student. Daubeny and Abich both availed themselves of the especially valuable opportunities afforded by Vulcano for making observations on the gases evolved by volcanic vents. M. Charles Ste.-Claire Deville and M. F. Leblanc, however, made a series of much more systematic experimental inquiries here in 1855-6. And still later, in 1865, M. Fouqué has continued these studies, and carried them much farther. To the results obtained by these eminent French chemists we shall have occasion to refer again in the sequel. It is clear from the foregoing sketch of the history of Vulcano, fragmentary and imperfect though it necessarily is, that all the usual phenomena of a volcano in the paroxysmal phase are exhibited by it. As far as our accounts enable us to judge, it would appear that scarcely a century elapses without one or more violent outbursts ; that sometimes the eruptions are continued with moderate violence during many weeks, months, or years, while at others the accumu- lated force is dissipated in a furious outbreak of comparatively short duration; and that, after these periods of intense activity, the mountain sinks into a state of comparative repose. All the usual phenomena of volcanic action are admirably illustrated in Vuleano— the shifting of the igneous vent along the line of subterranean fissure,—the formation, from time to time, of new craters,—the gradual filling up of these by the growth of small cones within them, leading as it would appear to grand paroxysmal outbursts, by which the crater is again relieved of its contents,—the decline of the volcano into the so/fatara stage,—and the opening of parasitical vents, and sometimes of cones and craters, upon its flanks. Since the last grand eruption in 1786, Vulcano has been in a state of almost complete repose, and even its gaseous emanations, appeared to be gradually declining in abundance and violence. Some writers had in consequence been somewhat rashly led to speak of it as a spent voleano. As if to make a protest against any such assumption, the voleano a little more than a year ago resumed its activity: and we may now perhaps infer that, having recovered from the exhaustion produced by its last terrific effort, during which the present vast crater was formed, it is now recommencing that series of moderate eruptions by which the crater will be once more filled and the vent so clogged that it can only be cleared by another great paroxysm. Fortunately for geologists, Signor Ambrogio Pinconi, the very intelligent manager of the chemical works in Vulcano, kept a diary of his observations on the crater during the late outbursts, and several times, indeed, at considerable personal risk, ventured into it while the 108 TW Ttdd==On Valeanos. eruption was actually in progress. During the continuance of the eruptions, the operations of the labourers in the crater were of course suspended; but the first explosions were so sudden that, before the workmen could make their escape, three of them sustained serious injuries. From the entries in Signor Pinconi’s journal, a copy of which now lies before me, and the notes which I’made on the spot only two months after the eruption had ceased, I have drawn up the following account of it. On the 7th September, 1873, signs of renewed activity began to be displayed in the crater of Vulcano, and a series of small eruptions took place within the crater. These continued with varying inten- sity and many interruptions until the 24th of October. On the 22nd January, 1874, the activity of the crater was renewed, and continued till the Sth of February. During these eruptions rumbling sounds were heard, which were compared to a fusillade alternating with discharges of cannon. These noises were audible at Lipari, which is situated at a distance of 6 miles from the crater. Several fissures were opened on the northern side of the bottom of the crater, and from these clouds of vapour were discharged and considerable numbers of stones thrown out. Some of these were of very considerable size; but the majority of them were, by repeated ejections, reduced to small fragments. Most of the stones fell back within the limits of the crater; but a few of them fell outside of it, and are seen scattered all over the sides of the cone. Some of these stones are 8 to 10 Ibs. in weight; they are composed of highly siliceous rock (quartz-trachyte), and can-be distinguished from the products of earlier eruptions by their pale-green colour and unweathered appearance. The fragmentary materials accumulated in great quantities around the orifices of ejection, and would doubt- less have given rise to the formation of small cones on the bottom of the great crater, had not the large quantities of materials shaken down from the adjoining crater-wall caused the whole to assume the form of a great bank or talus, leaning against the northern side of the circular cavity. On ascending to the top of this pile, which rises to the height of more than 100 feet above the bottom of the crater, I was able to see that from four still open mouths, ashes, lapilli and larger fragments of rock had been discharged, giving rise to the formation of a line of cones, the regularity of the building up of which had been greatly interfered with from the cause alluded to. From these open mouths considerable quantities of vapour were still (April 11, 1874) issuing. Among the blocks of obsidian and quartz-trachyte, usually with highly contorted internal structure, which strewed the floor of the crater and had been ejected during the recent Sep, were many which weighed several hundred-weights. Considerable quantities of white ‘ashes were ejected during these eruptions, and fell both in the islands of Lipari and Salina. While these eruptions were taking place within the crater of J. W. Judd—On Volcanos. 109 Vulcano, no change was detected in the state of the small fumarole which exists in the most recent of the craters of Vulcanello. During the whole period of these eruptions, however, Stromboli was in a state of extraordinary activity, and it is said that outbursts of the two mountains occurred almost simultaneously. On the other hand, I was assured that no correspondence could be discovered between the state of activity of Vulcano and the nature of the weather at the time. Having sketched the history of Vulcano, so far as we have materials available for the purpose, it will now be interesting to consider its present state, and to discuss the origin of its various features. As pointed out by Spallanzani, an admirable view of Vulcano and Vulcanello may be obtained from any of the high grounds in the southern part of Lipari. In order that the description of the island may be more readily followed, I have given, in Plate VII., a sketch taken from the mountain above Punta della Crepazza in Lipari, showing the great central cone of Vulcano, with its series of en- circling older crater-rings in the distance, and Vulcanello and the Faraglione in the foreground. The southern half of the island is made up of a series of semi- circular ridges, each of which exactly resembles, on a small scale, the well-known Somma. These old crater-rings, for such they evidently are, consist of alternations of lava-streams and beds of agglomerate, the whole interpenetrated and bound together by in- numerable dykes. On their outer sides these ridges slope gradually down to the sea; but towards the interior of the island they present bold precipitous cliffs. In these, as in the cliffs of Somma, the characteristic features of volcanic architecture can be admirably studied ; and equal facilities are afforded to the geologist, where the sea has eaten into these old cones, as is especially the case on the south-west of the island. (See Fig. 4, page 15.) These crater-rings, which culminate in Monte Saraceno (1581 feet in height), la Sommata, Monte Aria, and many other peaks con- siderably more than 1000 feet above the sea-level, are four in number, and are separated from one another by semicircular, flat- bottomed valleys, which are called Pianos. The whole of this southern part of the island is thickly covered with volcanic sand, produced in part by the decomposition of its rocks, but to which the ejections of the central cone are making constant additions. Con- sequently the island is almost a desert, a few fishermen only living on its southern shores, while some vine-growers maintain a hard struggle with the elements in sheltered nooks in the deep Pianos. No roads or even foot-tracks can be kept open, where every storm raises and redistributes the covering of volcanic sand ; and in this the traveller sinks to the knees at every stride, while the few cultivated patches have to be protected from the dust-clouds by fences of reeds. It is clear that the southern part of Vulcano has been the site of the formation of at least four volcanic cones, the central axes of 110 J. W. Judd—On Volcanos. which have been situated on aline directed N.W. and §.H.; and that the eruptions to which each new cone has owed its origin have, at the same time, destroyed the northern portion of the pre-existing one. The oldest crater-ring is composed of ordinary trachytic lavas, exhibiting all the character- istics and variations found among the products of the second period of eruption in the Lipari Islands; but the newer ones are found to present materials becoming continually more basic in composition, till at last they approximate to basalts and dolerites resembling those of Stromboli. The struc- ture of this part of the island will be made clearer by a reference to the accom- panying plan of the island, Fig. 10. Encircled by the four older crater-rings just de- scribed, and separated from them by a_ semicircular valley (‘‘Atrio”) deeply covered by volcanic sand, rises the active cone of Vul- cano. This is not, as a 5 glance at the sketch will show, a simple cone with a Fic. 10.—Plan of the Island of Vulcano, based on the summit crater like that of map published by the Italian Government.—a. The : four outer crater rings, culminating in Monte Sara- Vesuvius, but a truncated ceno. 6. The Atrio surrounding the modern cone. : ne ° c. The great crater. d@. The smaller crater of the conical mountain, in which Fossa Anticcha. e. The obsidian lava-stream (of the present crater occupies 279) fy, jne Eameling della Rabbiice, fara, an excentric position. No its three craters. one examining the upper part of the mountain can fail to perceive there the vestiges of a number of craters which have been successively formed and destroyed; and that the position of the central axis of eruption must have been subject to constant variation. ‘These con- clusions are confirmed, as we have seen, by those accounts of the state of the mountain in earlier times which have come down to us. The highest point of the active volcano is situated on the north- east of the crater, and is 1266 feet above the sea-level. The lowest point of the crater rim, that over which the road is carried by which access is gained to the interior, is 882 feet high, while the floor of the crater is 532 feet above the sea-level.! 1 There exists a remarkable discrepancy between some of the estimates of the height of the floor of the crater of Vulcano above the sea-level. Deville states it to be 837 feet, while Mr. Mallet gives it as only ‘‘a few feet,’ stating the depth of the crater to be from ‘‘ 1100 to 1200 feet.” My own measurements with the aneroid were repeated on three different occasions, and varied only between 497 and 535 feet. The J, W. Judd—On Volcanos. a! The floor of the crater of Vulcano is about 200 yards in diameter ; but its level area is much encroached upon by the talus that leans against its sides, and especially by the series of irregular cones which were thrown up on its northern edge during the late eruptions. The walls of the crater, which rise to heights of from 400 to 600 feet above its floor, are in their lower part vertical, but higher up slope outwards at an angle of about 45°. The diameter of the crater- rim is about 600 yards. The sides of the crater of Vulcano exhibit a series of admirable sections of the masses of agglomerate composed of materials of all sizes, often well stratified, and sometimes exhibit- ing the series of anticlinals all round the crater, which has been described by Mr. Scrope as so characteristic of the structure of volcanic cones. Some portions of lava-streams and dykes of vitreous lava can also be detected in the sides of the grand crater; but it is evident that the mountain has been mainly built up by fragmentary ejections. The floor of the great crater of Vulcano, and also of the little crater of the Fossa Anticcha, to be hereafter noticed, is covered by a hard, compacted mass of pumiceous materials, which, when stamped upon or struck with any heavy body, gives forth a dull sound ; this, as in the case of the well-known Solfatara of Naples, is vulgarly supposed to indicate the existence of vast cavernous hollows below the mountain. A much simpler explanation of the phenomenon has been suggested by Mr. Scrope (see Trans. Geol. Soc., 2nd series, vol. v.) ; and that there is no foundation for the popular notion is shown by the fact that many masses of compact tufaceous materials give forth, when struck, precisely the same rimbombo sound, even when situated at a distance from any crater. All over the sides and bottom of the crater of Vulcano fumaroles are seen discharging acid vapours and gases. Many of these are of insig- nificant proportions ; but very large ones exist on the north-western rim of the crater and at a number of points at its bottom. The sides of the fissures from which the vapours issue are sometimes red-hot ; Fouqué found that zinc was melted by the jets of issuing gas, and Mallet that the temperature of the lips of the principal fissure was in 1864 “sufficient to melt brass wire, but not sufficient to fuse a similar wire of bronze.” It is not surprising therefore to find that, with this elevated temperature, the more inflammable products of the fumaroles are ignited directly they reach the atmosphere. This would seem to be the origin of the feebly-luminous flames, usually of a blue colour, which are seen at night playing over some of the fumaroles; the existence of these will not of course be thought to give any support to the popular notion of masses of red flame rushing out of a volcanic crater during eruption, which has been clearly demonstrated to be an optical illusion. Around all the larger fumaroles are crusts of salts, usually of a white or pale estimate given in the text is that of M. Salino, and appears to be derived from the official survey. Possibly some irregularity in the action of Mr. Mallet’s barometer may account for the very inaccurate results which he was so unfortunate as to obtain, not only on this occasion, but in other observations about the same time at Stromboli, 112 J. W. Judd—On Volcanos. yellow colour, but sometimes exhibiting a bright red tint, com- municated to them by the sulphide of arsenic (Realgar). The distinguished chemists, who at the instance of the French Academy have studied the gases discharged from volcanic vents, have accumulated a large body of valuable information on this interesting subject. Vulcano affording such remarkable facilties for their investigation, has received much attention from MM. Charles Sainte-Claire Deville, Leblanc and Fouqué. Their con- clusions it would be impossible to detail, much less to discuss the bearings of upon geological questions, in the present sketch. Some of the more important facts obtained may, however, be briefly noticed. The elements which have been detected among the gaseous ema- nations of Vulcano are as follows:—oxygen, hydrogen, nitrogen, chlorine, iodine, sulphur, selenium! (first detected by Stromeyer in 1825), phosphorus, arsenic, and boron; and the presence of bromine is suspected though not proved. ‘The most remarkable circumstance is the abundance of boron in these emanations; this element not being an ordinary product of volcanic action, though found so abundantly in the hot springs of Tuscany. It has been clearly shown that the nature of the gases evolved varies with the temperature of the fumaroles. This fact is illus- trated by the following table, in which I have placed side by side a number of the analyses made by M. Fouqué : Sulphurous and Hydrochloric acids. Carbomickacidheaseser. <- Sulphuretted Hydrogen) traces} 10:0| 12:0) 0:0 10-7-| traces (OSS EAEID, caaesHidaAcoodarn unl? : : d : INPMAAOERE OG o6 sndeadcodosg aon|| h AZe) SE || Allen || OPS) yf Tbe els) a. was from a strongly acid fumarole, with a temperature of 360° C., which deposits sulphide of arsenic, chloride of iron, and chloride of ammonium towards its centre, and boracic-acid and sulphur at greater distances. b. was from a similar fumarole, but with a temperature of only 250° C. c. was similar to a and b. d. deposited similar salts to the former, but its temperature was only 150° C. e. was from a slightly acid fumarole, with a deposit of chloride of ammonium, sulphur, and boracic, acid, and a temperature of only 100° C. f. was similar to e. Sulphur appears to be deposited round volcanic fumaroles through 1 The mixture of sulphur and selenium deposited here received from Haidinger the name of ‘“ Volcanite.”’ J. W. Judd—On Volcanos. fas, the action of sulphurous acid and sulphuretted hydrogen on one another. The production of the large quantities of chloride of ammonium can scarcely be explained, however, unless we admit with Daubeny that nitrogen, under conditions of high temperatures and pressures, exhibits a chemical activity, very different indeed from its inert character under ordinary circumstances. The quantity of volatile matter issuing from the fumaroles of Vulcano varies from day to day, and new fissures are being con- tinually opened, while old ones become closed. Signor Pinconi assured me that, after the recent eruption, the fumaroles discharged with enormously augmented violence, and that they produced, at the time of my visit, at Teast four times the quantity of salts deposited before the eruption. Two condensing chambers had just been erected over the largest fumarole for the artificial condensation of the vapours, but sufficient time had not elapsed to test the success of this method of collection. At present, the crusts composed of boracic- acid, sulphur, and sal-ammoniac are dug up round the fumaroles and conveyed to the outside of the crater by an excellent road carried over a viaduct. The sulphate of alumina. which is also largely collected, is produced by the action of the acid vapours on the pumiceous tuffs and agglomerates composing the mass of the mountain. At the “fabbrica,” near the Faraglione, the products are roughly separated by simple machinery, sent from England for the purpose ; but the salts are forwarded to this country for purification. The cone of Vulcano is made up of agglomerates, often well stratified; the materials beg much altered through the permeation of the mass by acid gases and vapours, and often exhibit brilliantly variegated tints. Half way down the slope of the mountain, on its - northern side, is the little crater called Fossa Anticcha or Forgia Vecchia, the floor of which has a diameter of about 60 yards, while acid vapours are discharged by several fumaroles at its sides. In the sides of this crater, and in a great fissure near it, the characteristic quaquaversal dip of the materials in volcanic cones is well exhibited. The ejected materials are often seen forming beds dipping at angles of from 25° to 80°. (See Fig. 11.) The date of the formation of the crater called the Fossa Anticcha is quite unknown. It is clear that it existed at the time of Spallanzani’s visit to the island, and he imforms us that at some earlier period the collection and purification of the products of the mountain had been carried on in it. The lava-stream on the north-west side of the cone of Vulcano is composed of obsidian passing into Liparite, and exactly resembles those of the last period of eruption in the adjacent island of Lipari, which were described in the last chapter. Two points in connexion with this lava-stream are, however, worthy of especial notice. Firstly, although of great thickness, it has evidently consolidated on a slope of 35°, thus affording a striking illustration of the baseless- ness of the opinions maintained by Elie de Beaumont and M. Dufrenoy on this subject, by means of which they sought to support the exploded theory of “ Elevation-craters.” Secondly, i in its wonderfully contorted internal structure, its rent and rugged surface, and espe- DECADE I1.—VOL. II,—NO. III. 8 114 J. W. Judd—On Volcanos. cially in the manner in which, on reaching a somewhat less steep slope, its materials have been piled up into a high ridge, this current affords a most striking illustration of the extremely imperfect state of fluidity in which the vitreous lavas of Lipari were poured forth. (See Fig. 11.) Fia. 11.—Profile-sketch of the obsidian lava-stream (of 1775) on the north-west side of the cone of Vulcano, with the stratified tuffs seen in the side of the Fossa Anticcha below. The present fresh appearance of this lava-stream, uncovered as it remains by fragmentary ejections, is strongly confirmatory of the very recent date, that of 1775, which Dolomieu assigns to it. On the south side of the cone of Vulcano is another lava-stream, evi- dently of far older date, and almost completely buried under ejected materials. All the solid ejections of the existing cone of Vuicano appear to have consisted of the most highly acid rocks—Liparite, obsidian, and pumice—like the materials of the later eruptions in Lipari. Between Vulcano and Vulcanello rises the mass of volcanic tuffs, evidently the denuded fragment of a cinder cone, which is known as the Faraglione. Ina grotto in this mass, the sides of which continually drop with water abounding in acids and various salts, the most beautiful stalactites of sulphate of alumina, and various compounds of lime, iron, and occasionally of copper are formed. In this grotto I collected the brillant crystals belonging to the cubic system, of the hydrated compound of ferric and ferrous sulphates, called “ Voltaite,” a mineral first. discovered by Scacchi in the Solfatara of Naples. Around the Faraglione, fumaroles discharging vapour with sulphuretted hydrogen and carbonic acid gases at an elevated temperature occur, while others are found giving off the latter gas only at the ordinary temperature of the atmosphere; these latter have been justly compared by Deville to the Grotto del Cane, at the Lago Agnano, near Naples. The isthmus joining Vulcano and Vulcanello, and composed of fragmentary matters ejected by the volcanos, appears to have been ° formed in the sixteenth century. It is doubtful if Vulcanello be Dr. Walter Flight— History of Meteorites. 115 really the island which was thrown up in the second century before Christ. Its three craters have evidently been formed at very different periods (see Fig. 6, p. 58), and the newest of them still contains one or two active fumaroles; in the time of Spal- lanzani it was clearly in a much more active state. Some of the older lavas of Vulcanello were of basic composition. Such is the structure of Vulecano, which exhibits, as we have seen in its various features clear evidences of a vast series of paroxysmal eruptions, repeated, at not very distant intervals, during the whole of the historical epoch. In our next chapter we shall describe Stromboli, a volcano offering in its features, its modes of action, and its products, some remarkable and very suggestive points of contrast with Vulcano. (To be continued in our next Number.) TII.—A Craptrer in THE History or METEORITES. By Water Fuicut, D.Sc., F.G.S., Of the Department of Mineralogy, British Museum ; Assistant Examiner in Chemistry, University of London. (Continued from page 80.) Meteoric Irons found August, 1870.—Ovifak (or UVigfak) near Godhavn, Kekertarssuak or Island of Disko, Greenland [Lat. 69° 19’ 30’ N.; Long. 54° 1’ 22” W.]} The interesting story of the discovery of these enormous masses by Prof. Nordenskjold is already known to the readers of this Magazine through a translation of his original memoir. While ex- ploring in Danish Greenland in 1870, his attention was directed to the possibility that meteorites might be met with in Disko Island, by the accidental discovery of a block of meteoric iron in some ballast which had been taken in at the old whaling-station at Fortuna Bay, near Godhavn, and he urged the Greenlanders to search the district for masses of that metal. He proceeded to explore Omenak 1 A. E. Nordenskjéld. Redogorelse for en Expedition till Gronland ar 1870. K. Vet.-Akad. Forh., 1870, 873. (See translation in Grou. Mac., IX. 289, et seq.) —D. Forbes, Adstract Geol. Soc., No. 238, November 8th, 1871. Chem. News, November 17th, 1871.—A. E. Nordenskjold. Remarks on Greenland Meteorites. Abstract Geol. Soc., December 20th, 1871.—T. Nordstrom. Ofv. Vet. Akad. Forh., 1871, 4538. See also Grou. Mac., VIII. 570, and 1X. 88.—A. K. Nordenskjold. Les Météorites. Revue Scientifique, 1872, ii. [2], 128—G. A. Daubrée. Compt. rend., \xili. 1268. Compt. rend., \xxiv. 1542. Compt. rend., xxv. 240. E. Ludwig. Min. Mitt., 1871, 1. 109.—K. Hébert. Séance Soc. Geol. de France, February 5th, 1872. Revue Scientifique, i. [2], 858.—H’. de Chancourtois and M. Jennatez. Séance Soe. Geol. de France, February 19th, 1872. Revwe Scientifique, i. [2], 905.—G. A. - Daubrée.—Séance Soc. Geol. de France, May, 20th, 1872. Revue Scientifique, i. [2], 1169. Amer. Jour. Se., ii. 71 and 388.—F. Wohler. Nachricht. K. Gesell. Wiss. zu Gottingen, 1872, No. 11,197. Pogg. Ann., exlvi. 297. Ann. der Chem., clxiii. 247. Nachricht. K. Gesell. Wiss. zu Gottingen, 1872, No. 26. Ann. der Chem., clxv. 313.—G. Rose. Zeit. Deutsch. Geol. Gesell., xxiv. 174.—G. von Helmerssen. Zeit. Deutsch. Geol. Gesell., xxv. 347.—C. Rammelsberg. Ueber die Meteoriten (Samm. —wiss. Vortrdge), pages 14 and 18.—C. W. Blomstrand. Ber. Deutsch. Chem. Gesell., iv. 987.—G. Nauckhoff. Svenska Vet. Akad. Handl., 1872, i. No. 6. Ber. Deutsch. Chem. Gesell., vi. 1463. Mineralogische Mittheilungen, 1874, 109.—G. Tschermak. Mineralogische Mittheilungen, 1874, 165. Der Naturforscher, 1874, Nos. 49-52.— For a map of Disko see Geographical Mag., February, 1875.—J. Lawrence Smith, Compt. rend., 1xx. 301. : 116 Dr. Walter Fiight—History of Meteorites. and other islands north of Disko, and, on his return to Godhavn at the end of August in the same year, not only learned from ‘the Greenlanders that masses such as he sought for had been found, but he was shown a specimen of meteoric iron in confirmation of their statement. They were discovered, not at Fortuna Bay, but further eastward along the shore, at Ovifak, between Laxe-bugt! and Disko fjord, a spot than which there is none more difficult to reach along the whole of the coast of Danish Greenland, as it lies open to the south wind, and is inaccessible in even a very moderately rough sea. Nordenskjéld at once chartered two whale-boats, manned by Green- landers, and set sail for Ovifak, where, the sea being calm, they were able to land, and the stone at which they lay to proved afterwards to be the largest block of meteoric iron that they were to discover. _ As the readers of this Macaztne are already familiar with the description which Nordenskjéld gives of the condition under which these masses are found, we may break off here to consider the more recently published report of Nauckhoff, the geologist of the expedition of 1871, of the peculiar geological characters of the rocks at Ovifak (Blafjell, or Blue Cliffs) with which they are associated. The surface of the south-western and western portion of the island of Disko is composed of basalt, which extends as far as Smith’s Sound, and was probably erupted in Miocene times. In only afew points of the island, Godhavn, the islets of Fortuna Bay and Nangiset, the primitive rock is observed. It consists for the most part of slaty gneiss, passing over in some places into mica-schist and often traversed by veins of pegmatite. Granite was nowhere seen. Immediately overlying the gneiss is a basalt breccia of dark blackish-green colour, some two hundred feet in thickness. In places the large angular fragments are cemented together with calcite ; as a rule, however, they are so small that the rock at some distance appears homogeneous. Few cavities are observed, and they are usually filled with calcite, rarely with zeolites, Above the breccia lies a bed of basalt-wacké of rust-brown colour, and with amygda- loidal structure, the cavities containing apophyllite, chabasite, levyite, stilbite, desmine, mesotype, analcime, and other zeolites. Over this again rises a bed of basalt of vast thickness, sometimes attaining one thousand feet, and of a dark greyish green hue; it occurs not unfrequently in vertical regular six-sided columns. The texture is generally crypto-crystalline, though exhibiting in places the char- acters of anamesite and dolerite; the few cavities are filled with chalcedony, rarely with zeolites. At Ovifak the cliffs rise to a height of 2,000 feet above the sea-level. The upper portion consists of compact dark-coloured basalt. Proceeding downwards on the nearly vertical face, we see thick beds of red-wacké and basalt-clay, until already at mid height the face is hidden by vast screes of large and small fragments of basalt. Where the cascades of surface- water have removed the finer portions of the talus, and the face can be inspected to greater depths between the larger blocks of basalt, the basalt-wacké is seen which overlies the breccia. 1 See Gor. Mac., 1872, Vol. IX. Pl. VII. In this map two bays called Laxebugt are given; the one mentioned above is situated to the north of Disko fjord. Dr. Walter Flight—History of Meteorites. 117 On the shore below these screes between high and low-water, and within an area of about fifty square metres, twelve large and many small iron masses were found. The six largest weigh respectively 21,000 kilog., 8,000 kilog., 7,000 kilog., 142 kilog., 96 kilog., and 87 kilog. Thanks to the kindness of Prof. Nordenskjold, I am enabled to give a representation (Plate IV.') of the largest mass (about 19 English tons in weight), which is now preserved in the hall of the Royal Academy at Stockholm. The second block, weighing about nine tons, has, as a compliment to Denmark, on whose territory the meteorites were found, been presented to the Museum of Copenhagen. Another of the masses, weighing 195 lbs. 8 oz., is preserved in the British Museum. For the earlier account of the discovery of these masses the reader is referred to Nordenskjéld’s memoir,’ and Nordstrém’s paper. The expedition of that year, 1870, having no means of bringing such vast masses to Hurope, a new expedition was equipped by the Swedish Government in the following spring, consisting of the gunboat “Tngegerd,” Capt. F. W. von Otter, and the brig “ Gladan,” under the command of M. von Krusenstern, who brought the meteorites to Denmark in September, 1871. Nauckhoff in his paper draws attention to one remarkable block, about 200lbs. in weight, which lay three feet below high-water. On the under-side it was covered with basalt grains, cemented to- gether with hydrated oxide of iron, and consisted of coarsely crystal- line iron, containing much carbon, and which readily weathered. Sixty-five feet N.E. of the spot where the largest block lay, a ridge of dark brown basalt-like rock comes to the surface. Through its superior hardness it has withstood the denudation better than the loose basalt-wacké on either side of it. It is soon lost to sight, but reappears to take a direction towards the spot where the large iron lay. The rock forming this ridge resembles ordinary compact basalt. It is of finely granular texture. Near the margin it be- comes erypto-crystalline, and is seen under the microscope to consist of labradorite, greenish-brown augite and black grains of magnetite. It will be found, when we come to speak of the analysis of the rocks accompanying this iron, to accord in composition with the basalt itself. It differs from it, however, in the presence of two accessory constituents which are disseminated through the parts forming the edge of the ridge, and are: a greenish hydrated ferrous silicate resembling hisingerite, and a yellowish brown iron sulphide. The analyses of the former mineral, it will be seen in the sequel, show that it is not identical with the chloropheite so often occurring in basalt; the sulphide completely accords in composition with the troilite of meteorites. The columnar structure, so often found in basalt, was not noticed, the cracks occurring near the sides appearing to be all parallel to the margin. The surface of a freshly broken fragment displays peculiar smoothness and lustre. On the 1 This Plate will appear in the April Number with Part IV. of Dr. Flight’s paper. —KEpir. Grou. Mace. 2 Gzou. Maa. 1872, Vol. IX. pp. 461, 462, and Plate VIII. 118 Dr. Walter Flight—History of Meteorites. east side of this ridge, and in the solid rock, a piece of much-weathered iron was found inclosed by Nauckhoff; while another member of the expedition, Mr. J. Steenstrup, detected metallic iron on the west side of the ridge. The analysis of this iron, apparently that which was analysed by Lindstrém, will be referred to later on. While blasting this basalt, a rock was hit upon which was at once seen to differ con- siderably from the matrix. It consists of a greenish ground mass, inclosing spangles and grains of iron, and occurs in rounded masses that are separated from the basalt by a coarsely crystalline greenish shell, about 20 mm. thick as well as by an outer rusted brown crust. The boundaries of these masses were well defined; in no instance were they detected passing over into the basalt. The masses of iron lying in the basalt ridge usually had an ellip- soid form and a rusted crust, that allowed of their being easily detached from the basalt. Nauckhoff succeeded in removing six lumps, the aggregate weight whereof was 150 Ibs. This iron is hard and crystalline, exhibits Wiedmannstittian figures, and is in every respect like that of the large loose blocks. Moreover, like them, it unfortunately possesses the property of exuding a yellow liquid (ferrous chloride), and of weathering away. It was noticed that these inclosed masses had their major axes parallel to the direc- tion of the ridge, and that they were in a way connected with each other by little veins of weathered iron. Nordenskjéld states that the large free blocks of metal had a tombac to rusty-brown colour, and, when found, exhibited metallic lustre on parts of their surface. Here and there, fragments of basalt, similar to that of the ridge, were found adhering to them. The inner parts contained none of the rock, and his analyses detected the presence of little silicic acid. They were strongly polar, the upper surface attract- ing the north, the lower side the south pole of the magnetic needle. The iron of the large masses is crystalline and brittle, so that pieces can readily be removed with a hammer; the metal of the ridge is tougher, and has a rougher fracture. The presence of troilite was rarely detected in the detritus; a few black magnetic grains were met with which, by their octahedral faces, were recog- nized. to be magnetite. The characters of the polished sections of the different masses differ greatly : in some the surface shows rounded areas of varying brightness and shades of colour, with parts of a brassy yellow (troilite) ; others are more homogeneous, or appear to be made up of fine prisms of “carburetted nickel-iron.” Some, not all, exhibit figures when etched. Though containing little sulphur, the Greenland irons, since they - have been brought to Europe, have shown a marked tendency to crumble to pieces. On the shore at Ovifak, sometimes exposed to the wash of the waves, sometimes left high and dry, but preserved at the constant temperature of the sea, which varies little throughout the year, the masses apparently underwent little change. Already during the passage, however, many fragments crumbled away, and when unpacked at Stockholm two months later, and placed in @ room of ordinary temperature, others broke up into a reddish Dr. Walter Flight—History of Meteorites. 119 brown powder. A freshly fractured lustrous surface of one of the masses commenced in one corner to rust, expand and crumble away ; while the remainder experienced no change, till at length the oxida- tion extended into the interior and the whole fell to pieces. Ina hermetically sealed glass tube the iron is preserved unchanged ; but in another tube with a fine crack oxidation continued. In alcohol no change takes place; in air, dried by sulphuric acid, the change is greatly impeded. Attempts to preserve them by coating them with varnish were of slight avail. The cracking is caused by dilatation, and takes place with such force that masses of metal, on which chisel and saw were without effect, are broken and bent out of shape during oxidation. Nordenskjéld found that a fragment of the largest iron, when heated to redness, gave off more than 100 times its volume of a gas which had a bituminous smell. It was evidently gas not simply occluded by the metal, but was produced by the decomposi- tion of “the organic matter in the meteorite,” through the reducing action of those compounds on the oxide of iron associated with them. When such iron is treated with mercury chloride but little gas is evolved; in aqua regia it dissolves, leaving in some cases a carbonaceous residue, in others very little residue of any ‘kind ; by the action of hydrochloric acid a gas is given off which has a penetrating odour resembling that of some hydrocarbon. By treat- ment with acid a humus-like compound appears to be generated, which is soluble in ammonia, insoluble in acid, and can be oxidized only with difficulty by long boiling with very strong acids. In Nordenskj6ld’s paper are given the earliest analyses of these irons: I. Fragment of one of the large iron masses: this specimen evolved more gas than II. and III. Specific gravity =5-86—6-36. Analysed by Nordenskjéld. II. Fragment of iron, more compact and less crystalline than I., probably from the basalt ridge. Small grains were observed to be malleable. The specimen from which this was taken subsequently crumbled away. Specific gravity =7:05—7-06. Analysed by T. Nordstrom. III. Fragment of iron from the basalt ridge, which exhibited well-marked Wiedmanstittian figures. In external appearance this iron exactly resembled II. Specific gravity=6°24. Analysed by G. Lindstrom. Ie : II III Tron iecveetenceecieass o2od000 84:49 se 86°34 ae 93°24 INT CKE] Ei eeneccereecaccssssees Doe Sie eee LGA 2" tees 1-24 Cobaltite eect scecGecns scence. AD Seale aanag ORS Oh inirecn cee 0°56 (ChOjDDGIE >! S50 codaapee Homeboeos Os2ieree faeees. OMOM Oona 0-19 eNOS PHOLUSHe=t -aetlesesvcee OPA) GSc00c CROC Fiss65s0 0:03 PSH FO) SREEE cones USGS Geatecas 0-16 ZAAIDBTITINE) -oacocoosocopecpan6eD WHEXES)——- co90< ORD ee ees == ABIES: BL acon eee trace 3 (pees) = G0006 — WEES) Lobosco sob aseNens 0:04 .). Sesiies Op295 vkees trace Potasheonccceecte tenet ass (ENG) sc0-55 0-07 0-08 Soda ..... TEACEW Neco OETA Gecercs 0-12 PSHULTIOO EKENG, coonsoooneoccanee LEEKS ine hoen OPGGr) ee soces 0-59 Insoluble portion........... 0205) e iacae: OER weecheacd Carbon, Organic Matter j Carbon... 2°30 Oxygen, and Water... AUD 80 etl Hydrogen 0-07 100-00 99:93 99:79 Nordstrém analysed the carbonaceous residue of the compact iron 120 Dr. Walter Flight—History of Meteorites. II., after digestion with double chloride of copper and sodium, and iron chloride, and found, when a quantity of ash is deducted, that it is composed of : (CATE DOS + dcatiecobocondedseseo00 OED) coaose 63°64 Helv dno Sen! Weereceecseceecnese 3°26 pena 3°55 Oxygen (by difference) BUD © © gece 32°81 100-00 100-00 These numbers yield no satisfactory atomic ratios, and it is not improbable that the carbon is present in two allotropic modifications, as well as a constituent of a complex organic compound. In 1872 two interesting papers were published by Wohler on the results of his examination of this iron, especially that from the ridge. The specimen he chose for examination came from a vein of metal several inches wide and some feet in length, which was inclosed in a rock “that presents a marked difference in composition from the basalt breccia whence it protrudes.” He describes this iron as bearing a close resemblance to grey cast iron; it has a bright lustre, is very hard, is quite unalterable in air, and has a specific gravity= 5°82. Nordenskjéld, as we have seen, extracted gas from the metal of the larger masses by heating it. Wohler finds that the iron of the vein evolves more than one hundred times its volume of a gas that burns with a pale blue flame, and is carbonic oxide, mixed with a little carbonic acid. The “iron,” in fact, contains a considerable amount of carbon, as well as a compound of oxygen ; and, according to Wohler, can at no time have been exposed to a hich temperature. After it has been heated, the iron becomes brighter, and, though more soluble in acid, it still leaves a carbonaceous residue. A fragment heated in dry hydrogen, with a view to determine the amount of oxygen present, formed a quantity of water, and lost 11-09 per cent. of its weight. ‘It contained, in other words, 11:09 per cent. of oxygen.” ‘It is not stated whether the water corresponded in weight to that amount of oxygen. Hydrochloric acid acts but slowly and imperfectly on this metal, evolving first sulphuretted hydrogen, and then hydrogen possessing the odour of a hydrocarbon, and leaves a black granular magnetic powder, which, though insoluble in cold acid, generates on the application of heat a gas with a strong odour of a hydrocarbon, leaving a residue of amorphous sooty carbon and slightly lustrous graphitic particles. In iron chloride the “iron” dissolves without evolution of gas, about 30 per cent. of a black residue remaining, which, after having been dried at 200° C., lost by ignition in hydrogen 19 per cent. of its weight, water being pro- duced. It is now very readily attacked by acid, evolves sulphuretted hydrogen, and gives a residue of nearly pure carbon in powder or in graphitic scales. Iron chloride and acid appear, therefore, in the main, to remove the free metal only, and to be without action on the compounds with sulphur and oxygen. The ultimate composi- tion of the specimen he analysed is as follows: Tron epic nencenes ses sonic 80°64 Sul phurweeseepeesmeeeeee 2°82 INI Chel iesaeee reps secessen 1:19 Carbon. icclsesaecesestmess 3°69 Phosphorus cerececeseeave O715. Dr. Waiter Fliight—History of Meteorites. 121 Wohler was disposed to regard the oxygen, constituting so consider- able a portion of an apparently metallic mass, as present in the form of a diferrous oxide, Fe,O, were it not that, according to this view, there would be no iron provided for combination with the sulphur and carbon. As, however, Nordenskjéld found magnetite in or near other Ovifak irons, Wéhler regards that constituting the veins as an intimate mixture of magnetite, of which there would be 40-20 per cent., with metallic iron, of which there would then be 46°60 per cent., the sulphide, carbide, and phosphide, as well as the alloys with nickel and cobalt, and some carbon in isolated particles. The latter probably undergo no change when the magnetite and carbide, by the action of heat, generate carbonic oxide. A specimen of the iron from the basalt has also been investigated by Daubrée; he describes it as having a metallic lustre and being nearly black. He found its composition to be: Il, Tron in the free state........ssecseses Uae seele een 40-940 Tron in combination ..... Sauiees Aeataras Le tol atleteled : 80°150 Canbonvinythebinecistatens.sssesescerenscceccene 1-640 Carbonkinicombinatiommcsesesscecerssseosedceseee 3°000 INSEE secooooned vaasesee Seeedidsmsetoece’ SSiedeas 2-650 Cobaltirstessstossesecbesesteees SHPO RAE DCOCCSS 3 0-910 JANOS} AOI RiggocconcasqacHoodoecoooaca000¢ oons0n0000 0-210 ARSON CHa snecnoseeoasesamereesae eo asmsebes ehacenes 3 0-410 Sul piu eneeseeeaceusceenescoceeececersees 0 2-700 SUGIUME eo eva saaPeccusecceeeteees RUE Fe haa he 0-075 INTRO EREL Geqooccaboscccachonoconeanobeeoooocanctncs 0-004 Oxygen ....... vesunitoncenbescevete gogpn0sdo0600 000 12-100 NWiaterm (hie rOnlettlC)Passsesacnsensssctaaricncaces . 0-910 WiatersimucombinatlOnmrsssststesseeeienescncnece 1:950 ‘ Chromium, Copper, etc............ GonbHOoECOOS 2006 1-010 Calcium sulphate, chloride, ete. ........ oqge000 1°354 100:0138 In his second paper he gives analyses of two more specimens : II. Light grey iron, possessing metallic lustre. It is not homongeneous, as it might be assumed to be from its lustre and colour. When crushed in a mortar, it is divided into two parts: the one crumbles to fine powder, the other is flattened into plates, requiring much trituration to break them up. III. Metallic grains mechanically separated from the rocky portion in which they were distributed. These spherules exhibit figures, when etched, and contain silicate distributed in very fine pieces throughout their mass ; in one rounded fragment the silicic acid of this silicate amounted to 11-9 per cent. of the total constituents. II. III. Tron in the free state . sae vee 80°800 ... 61-990 Iron in combination ... ... ... 1°600 ... 8110 Carbon in the freestate ... ... 0°300 ... 1:100 Carbon in combination ... ... 2°600 ... 3°600 Silchonieere ieee eee eeci een OVD) css = Water... ... sey igse) ean wy OF 700: occ — Calcium chloride... eee aay faa Ove oor aeeseoan Onl 46 Tron\ chloride! ey eee ee ee 0089) 0-114 Calcium ys cop coe aca, DADE) aoqe 9 OHUEEr/ Coppers. elects: trace. ... trace. It will be seen that specimen im is not less rich in carbon than I., and that specimen II. also contains a considerable quantity. 122 Dr. Walter Flight—History of Meteorites. Specimen I. is distinguished from II. by a large proportion of com- bined iron. By treatment with alcohol, calcium chloride was extracted and determined in I.; with cold distilled water, the soluble salts were removed from IJ. and III. 1. contains more lime sulphate and less chloride than II. and III. These meteoric masses are distinguished by the amount of carbon, free and combined, which they contain ; by the presence in them of a large proportion of iron in combination with oxygen, but in what state of oxidation is not clearly ascertained ; and by the occurrence of soluble chlorides and sulphates, especially calcium sulphate, throughout their structure. No salt of potassium has been detected in them, nor, which is very remarkable, has sodium chloride been found, although carefully sought for. The intimate distribution of these salts through the Ovifak iron is certainly an indication that they must be numbered among the original constituents of these meteorites. Daubrée noticed that specimen IJ. showed a marked tendency to absorb water and to rust away; a few days sufficed to make this apparent. The local nature of the oxidation he attributes to the irregular distribution of the deliquescent salts. Among these com- pounds, instead of iron chloride, to the action of which the decay of meteoric iron has usually been ascribed, calcium chloride appears to play the most prominent part. In support of this view it may be remarked that No. II. iron, the one most liable to change, is that containing the greatest proportion of this salt, the amount being six times that met with in No. L iron. Calcium and magnesium sulphates were noticed by Daubrée to form constituents of the Orgueil Stone, and the latter salt is also present in the aerolites of Kaba and Alais. All these are carbon- aceous meteorites. May the calcium sulphate of these irons, as well as that of the above-mentioned aerolite, be a product of the oxidation of a calcium (magnesium) sulphide such as occurs in the meteorite of Busti, which stone also contains, among other constituents, augite and metallic iron ? The greater stability which these masses exhibited so long as they were in polar latitudes is no doubt due to the reduced tension: of aqueous vapour; had they fallen in regions further south and been exposed to a milder climate, they would without doubt have long since fallen to powder. In his second paper Wohler points out the probability of the No. II. iron which Daubrée examined being of the same kind as that which he himself analysed. He remarks that, although Daubrée found this variety of the metal to show a tendency to oxidize even in a few days, his specimen had remained bright and unchanged after it had been a year in his collection. Nauckhoff, whose exhaustive examination of the rocks associated with the Ovifak irons we shall immediately turn to consider, analysed the spangles and spherules which can be removed by a magnet from the rock that occurs in rounded masses in the basalt ridge, and of which the composition is given in the table of his analyses under III. Some of these spangles could be pulverized only with difficulty, and Dr. Waiter Flight—History of Meteorites. 123 were readily flattened out; the spherules, though so hard that a sharp steel file would scarcely touch them, were easily crushed. They had the following composition : JGROM 8 oo6 00. G00 coo. | HEHZB) Phosphoric acid ... ... trace. INGCKelY cs, 46.) hates 2G ANNI, e65, con) con CHESS Cobalt 5 eens a ore O00 Nickel and Cobalt oxides 0°44 Copper :.se smears ges IIE YETOGSIE) Gog) S50 cn OP Jekyaloe@nios Hon ed Macs US Dimicme sessed hse) O00 Canbontcamarsc-yi ce tec el sO4: ROCK) 560, cog 2 ood.) coo UO SU phase eene ee eee OG Potash ss) scl ieee) econ) ULACES Chlorine isso) issue Onke INGHGIE 5 S65 coo con) OPW Mapnetite ... ... ... 30°42 ; Silicicyacigusessecieresa nl O226 102°64 In the basalt of the ridge, of which an analysis is given under II. in the same table, a compact, very brittle, yellow, or slightly brown mineral occurs in thin flakes, sometimes in nodules of the size of a pea; it is invariably penetrated and usually surrounded by a mineral resembling hisingerite, to which attention will presently be directed. The mineral has a hardness of 5 to 5°5, and easily fuses before the blowpipe with evolution of sulphurous acid to a magnetic regulus. It has the composition : Equivalent Ratios. TSM o5 Goo ono | eS en POI cco. ROSS 9-958 Nickel iteccner-s nts 0 Glue OO OMmener felon | Copper ... ... trace. ... trace. ... = Sulphur... ... 38341 ... 36°56 ... 2°285 Silicate: Sn o> 1 88b9! ck I ee : 100-00 100-00 ; These numbers give the formula (Fe, Ni) §, or that of theiron (nickel) monosulphide or troilite, which has hitherto only been met with in meteorites. Intimately associated with the troilite, and evidently a product of its oxidation and further alteration is the mineral already men- tioned, the fresh fracture of which is of a light olive-green colour, that by exposure to the air soon becomes brown, and after some days turns quite black. Its specific gravity is 2-919, and composition : Oxygen. SHUEY EVOL” cos G0. cod cco BL tes. ceo HG INO SESOUOSCS 5G oon cco ON) os es | ong protomidensel ess Mices Met OVO Wiese Wieeel mOECO VabeE Me teresa Fieei) socq ieee OLOOMm nerenmayen he. 0o 100-56 These numbers indicate the formula: Fe0,Si0,+3(2Fe,03,38i0,)+14H,0 as that of the mineral. Nauckhoff, however, draws attention to the rapidity with which the oxidation of the pulverized mineral takes place: five days after the analysis was made the per-centage of iron protoxide in another portion had fallen to 3-47, and after three weeks to 1:55. The original unchanged mineral was probably a hydrated ferrous silicate. (Zo be continued in our next Number.) 124 J. Starkie Gardner—On the Gault Aporrhaide. IV.—On THE GavuLt APoRRHAIDZ, By J. Srarxre Garpner, F.G.S. (PLATE V.) (Continued from page 56.) Addenda and Notes to Group 1. Since the appearance of the first part of this paper, I have had, through the kindness of M. Deshayes and Prof. Gaudry, an opportunity of examining the original specimens in D’Orbigny’s cabinet in the Jardin des Plantes, and am enabled to add the fol- lowing to the list of species included in Group 1. They are all in the Prodrome :— A. Aonis, D’Orb., from the Chalk. A. Mailleana, D’Orb., id. A shell of larger size than 4. refusa or A. Fitton, with very angulated whorls, one strongly developed keel visible to the apex of the spire, a second keel visible on the last whorl only :—-wing unknown. The figure in the Pal. Fr. does not resemble in its characters the specimen in the cabinet numbered 6238, which is identical with one of the two Grey Chalk species mentioned last month as undescribed. If the figure is correctly drawn, there are two species under this name :— A. (Pt.) marginata, D’Ovb. Some of the specimens are probably A. retusa, but others are more globular, and are regularly and deeply striated, resembling the second undescribed form mentioned from the Grey Chalk. Any definite opinion as to their identity must be reserved until better specimens are procured. The figure in D’Orb. Pal. Fr., pl. 217, fig. 2, is much larger than any in the cabinet, which do not exceed the dimensions of the test of A. retusa. A. Moutoniana, D’Orb., and A. provincialis, D’Orb., from the Neocomien of HEscragnolles and Var, are probably the A. Fittoni of the Lower Greensand. A, (Pt.) Rochatiana, D’Orb., has the form of A. Fitton, but with unkeeled, inflated upper whorls, and tuberculated keels on the lower whorls. Neocomien. A. angulosa, D’Orb., from Sta.-Fé de Bogota, is a small distinct species, with angular and pronounced keels. Neocomien. A. Americana, D’Orb., id., Colombia, St. Martin (Var), and Chateau-neuf (Hautes Alpes), has a slightly longer spire, angular whorls, keels as in A. Mailleana, and short expanded wing, linking the present group with Groups 3 and 4. Fusus Cottaldinus, D’Orb., Ste.-Croix, is the young of A. retusa. There is also a very distinct form in the splendid museum of the Ecole des Mines in Paris, which has a globular shape, with depressed spire ; all but the last whorls strongly striated and reticulated. The Strombus pyriformis, Kner, figured by Geinitz in the Quader- sandsteingebirge, is probably intended to represent this species, as it is from the same locality—Lemberg. Geol. Mag. 1875. NEW SERIES. Deeadell. VoLILPL. V (Po De Wilde delet litle. Fossil Aporrhaide. J. Starkie Gardner—On the Gault Aporrhaide. 125 The specimen labelled 4. retusa, from Devizes, in the Jermyn Street Museum, has an expanded wing, and is more elongated an- teriorly than A. retusa from Folkestone. Addendum to Group 2. There are two specimens from the Upper Greensand of Evershot of a large Aporrhais, allied to A. cingulata, in the collection of the Geological Museum, Jermyn Street. I shall take a future opportunity of describing them. Meanwhile, as they are perfectly distinct from any other Continental or British form, I propose to name them Aporrhais Etheridgii, in compliment to Mr. Etheridge, F.R.S., Palezontologist to the Geological Survey of Great Britain. Erratum in last Number: p. 58, line 18, read, except from Aachen, Group 3.—Spire long, whorls angulated, carinated or bicarinated, spirally striated, generally with nodes or ribs transverse to the whorls; wing narrow and long, simple or bifurcated. No posterior canal. Type :—Aporruais cARtNATA, Mantell (1822). Plate V. Fig. 1. Description. — Spire elongated, composed of about 12 convex angulated whorls, forming an angle of 21°; finely striated spirally, ornamented transversely on the convexity of the whorls by 10 or 11 salient, slightly oblique and generally elongated tubercles. The sutures are very visible and slightly keeled. Fainter and less regular striz cross the spiral lines, and coincide in direction with the ribs ; they are especially visible on the sutural keels. The tubercles en- tirely disappear on the last whorl, and are replaced by two very salient angular striated keels, the posterior of which is most prominent and is prolonged to the extremity of the wing, in the form of a very strong, narrow, rounded ridge; this ridge or wing process runs at first at right angles to the axis, and then abruptly curves upward and continues more or less parallel to the spire, which it equals or even exceeds in length; it terminates in a sharp point or canali- culated spine. A second anterior keel rises in most specimens, if not all, near the margin of the lip, runs parallel to the first for a short distance, and at the point of curvature, diverges in an opposite and slightly outward direction in the form of a comparatively short and sharp, solid spur; the space between the two keels forms a narrow triangular wing, truncated at its extremity. The wing is applied to the last, and sometimes very slightly to the penultimate whorl ; although slender looking and elegant, it is remarkably thick and strong. The spire measures ‘046, canal :036; breadth, including wing, ‘036; the length of posterior digit from the point of curvature is ‘054, and of the anterior digit 012. The outer lip between the wing and anterior canal is slightly sinuous; the anterior canal equals the length of the spire, is slender, and is either straight or curved to the right. Mouth narrow, columellar lip encrusted immediately: round the aperture. A slight modification of this species occurs in the Upper Gault, in which the posterior digit of the wing is shorter, straighter, and diverges outwards; the anterior spur is longer in 126 J. Starkie Gardner—On the Gault Aporrhaide. proportion to the wing, and the tubercles seem less elongated. ‘They occur usually in a crushed condition. Distribution.—This and _A. marginata, Sow., are the most abundant Gasteropods at Folkestone, ranging through all the beds of the Gault, and being frequently found in masses together. Mantell, Fitton, and others mention it from Ringmer, Ridge, Bletchingley, Laughton, Norlington, Warminster (?), Cambridge, ete. On the Continent its distribution seems restricted to the Paris basin, but many of the casts figured under other names may, on examination, be found to belong to this species, and its known localities would be thus extended. The spire without the last whorl or wing process may easily be confounded with A. marginata, and in the form of casts they are still more difficult to separate. It is eminently characteristic of the Gault. . History.—This shell was first figured and described by Mantell as Rostellaria carinata, in the Geology of Sussex, in 1822, p. 86, tab. xix., figs. 12 to 14; again by Sowerby in Fitton, 1886; and by D’Orbigny in 1842, who first published a tolerably perfect repre- sentation of the species. It was next noticed in D’Orbigny’s Pro- drome. Pictet and Campiche did not figure this form, but it is mentioned on page 624 in their list. In 1859 Dr. Chenu figured it, page 259 in the Manuel de Conch., as Pteroceras carinata. Mr. R. Tate in 1865 described it in the Geol. Repertory, p. 97, fig. 17, as an Alaria. It is the Gladius carinatus of Gabb, 1861. Considering its abundance, it is surprising that it should have been noticed by so few authors, but it probably is owing to the re- semblance of its spire and ornamentation to that of _4. marginata. The following may be identical with 4. carinata or are closely allied :—R. Pictetiana, de Loriol, 1861, Neocomien ; BR. elegans, id. ; R. Neckeriana, Pict. and Roux, Perte-du-Rhone, figured from casts. Pt. tuberosa, Briart and Cornet, though greatly resembling A. carinata, is probably distinct. ApoRRHAIS ELONGATA, J. Sowerby. Plate V. Figs. 2, 2a, 3. Description.—Shell very elongated, spire forming an angle of 20°, and consisting of nine or ten convex whorls, which are one and a half times wider than high, finely striated spirally, and with ten or eleven salient, rounded ribs, which extend across the entire breadth of the whorls. Three or four of the striae are much more defined near the ~ apical suture, and form a narrow, distinct, flat region between the con- vex parts of the whorls, thus giving a decided character to the shell; the ribs nearly disappear on the last whorl, which has a single in- distinct keel. The wing is a long straight projection at right angles to the axis; longer and narrower than that of A. carinata, which its termination should resemble. I have seen no specimen more perfect than the one I have figured, Plate V. Fig. 2; but John Griffiths, of Folkestone, remembers finding one with a wing terminating “ like a pickaxe.” his specimen, he thinks, found its way into Mr. Wiltshire’s cabinet. The outer lip is angular; the columellar lip encrusted with the aperture, resembling 4. carinata. The anterior J. Starkie Gardner—On the Gault Aporrhaide. 27 canal is long, and curved slightly to the right. The length of the spire is ‘054 and the canal -038. Distribution — Gault of Folkestone, where it is rare; Cambridge (?). History.—In 1836 Sowerby figured an undoubted fragment of this shell in Fitton’s Memoir, Trans. Geol. Soc., pl. xi. fig. 16, p. 336, with the following note :—‘‘ Presumed to be a Rostellaria from its resemblance to R. marginata; from which it differs in its great length and smaller ribs.” It has, however, a stronger resemblance still to A. carinata, to which it is most closely allied. D’Orbigny in the Prodrome, Pictet and Campiche, and Gabb mention it from Folke- stone only, on Sowerby’s authority. This shell should continue to rank as a species, for although each differing character is not in itself of great importance, yet combined, they give a very distinct aspect to the shell. Avorruais maxima, Price (A. marginata, Pict. and Camp.). Plate V. Fig. 4. Description.—Spire elongated, composed of eight or more convex whorls, forming a regular angle of about 80°, finely striated spirally, and ornamented transversely by about twelve regular ribs to each whorl, which extend from suture to suture. These ribs disappear on the last whorl, and are replaced by a single prominent and angular keel. The wing and anterior canal resemble those of 4. carinata. Distribution. Gault of Folkestone, upper and lower beds. Gault of the Perte-du-Rhone and Ste.-Croix. History.—An impression of a shell of this species was found at Folkestone by Mr. F. G. H. Price, who named it Rostellaria maxima, and described it in the Gronogican MacGazine for March, 1873, Owing to the crushed condition of the only specimen then known, and which I at the time carefully examined, it was not till a second specimen was found that I observed it to be identical with 4. marginata, Pict. and Campiche, whose figure 2, pl. xciv., almost exactly resembles the fragment I have here figured. Pictet and Roux’s figures present the same characters, but are of much smaller size. It is very desirable to obtain more perfect specimens. AporrHais Cartnetta, D’Orb. Plate V. Figs. 5, 6, 6a. Description.—Shell elongated, the spire forming an angle of 21°, composed, when perfect, of twelve angulated whorls with a strongly developed, acutely angular keel, situated a little anterior to the middle of each whorl; a second anterior keel is nearly concealed by the suture, but appears on the last whorl. The whorls are finely striated, especially the region anterior to the keel. The ridges, which are very salient, are finely tuberculated at their apices, except on the last two whorls. On the last or body-whorl, the keel is still more prominent and acute, and is prolonged into a straight, angular, ridged or carinated process, at nearly right angles to the axis of the shell for a distance almost equalling the length of the spire, where it bifurcates; the anterior digit being a very short spur, and the posterior, a long, gradually recurved point. The aperture is narrow, 1 Sowerby having employed the name marginata for a different species,—that now known as Orbignyana,—Mr. Price’s name may stand. 128 J. Starkie Gardner—On the Gault Aporrhaide. and the outer lip sinuous: the anterior canal very long, slender and tapering; the columellar lip is incrusted. The length of the spire is ‘023, and the canal -017; the breadth, including wing, -024. Distribution.—It is rare at Folkestone, and is not recorded else- where in England. It is found in France and Switzerland—in the Paris basin, at Hrvy, Dienville (specimens in the Sorbonne Museum), Girandot, Ste.-Croix, etc. History.—This species was described by Sowerby in 1832 as a Fusus, and named by him carinella, in the Trans. Geol. Soc. 2nd series, vol. iii. p. 418, pl. 39, f. 24, and quoted by Michelin, Mém. Soc. Géol. vol. iii. p. 100, 1838, without description, as a Rostellaria. In 1842 D’Orbigny, in the Pal. Franc. Terr. Crét., vol. ii. p. 287, pl. 207, figs. 7 and 8, gave an excellent figure of this form. It seems to have had a wide range, being mentioned in the Prodrome, and by ° Cornuel in 1851 from the Haute-Marne, by Cotteau, 1854, and Raulin and Leymerie, 1858, from the Yonne. In 1864 it was figured by Pictet and Campiche, pl. 94, figs. 4—7, p. 616; the only difference between their figures and the present arises from the im- perfection of the specimens they had to describe, as the striz and tuberculated carinz are only seen on very well perserved examples. In 1865, Mr. R. Tate mentioned it as a British species, and in 1869 it is found in Jaccard’s list from the Middle Gault of Ste.-Croix. APORRHAIS CALCARATA, J. Sowerby. Plate V. Figs. 7-14a. Description.—Shell moderately elongated, conical; spire forming an angle averaging about 82°, diminishing rapidly towards the apex, which forms an obtuse termination ; it is composed of six convex whorls. The whorls are finely but very distinctly striated spirally, ornamented transversely by many oblique, flexuous and equal ribs. Commencing from the apex, the first three whorls have a prominent angular, median keel, the transverse ribs not becoming visible till the third whorl; on the fourth and fifth the keel is hidden by the succeeding whorls, to reappear on the last. On these (the fourth and fifth whorls) the ribs are also very pronounced, and are still quite visible on the posterior region of the last. 'The last whorl has therefore a salient, angular keel at about its centre, and a less salient keel anterior to it; the region posterior to the dominant keel is ornamented by transverse ribs, similar to those on the other whorls, and, as stated above, the keel is continued up the spire, but is hidden by the suture; the remainder of the whorl is finely but distinctly and regularly striated. The dominant keel is prolonged in a strong, striated, and acute narrow and simple digitation, at first at right angles to the axis, and then curving gradually upwards, it exceeds the spire in length, and terminates in a sharp point. In many specimens, however, it is shorter, and perhaps a little broader. The aperture is narrow, and is encrusted on the columellar side; the anterior canal is long and straight ; the outer lip is toothed ; and the wing applied to the last whorl only. The average length of the shell is about -006; they are found at Blackdown as long as -020. In a specimen from an upper bed of the Gault at Folkestone, Fig. 10, there are more whorls, the keels near the apex are less visible, J. Starkie Gardner—On the Gault Aporrhaide. 129 and there are no ribs on the last two whorls; the canal is very long, considerably exceeding the length of the spire. The Blackdown specimens present a somewhat different aspect, and the description of this species, to apply to them, has to be modified in the following manner :—there are seven to eight or nine whorls, the spire varies from an angle of about 22° to 33°, and is sometimes pupeform, but with the apex drawn out and tapering very gradually. The last two or three whorls form an obtuse termination in exactly the same manner as the Folkestone shell, but this termination is far less conspicuous, and only to be seen in well preserved specimens, or by the aid of a lens, as the spire tapers to a finer point, and the apical whorls are therefore smaller. The mode of growth is the same as that of the Folkestone forms, but nothing could be more variable than the number and distinctness of the ribs. These are sometimes entirely obliterated, leaving only faint traces in crossing the keels (Fig. 8),’ sometimes they are very pro- nounced and regular (Fig. 1). On the last whorl in particular, the ribs are sometimes wholly absent, in other cases they extend to the anterior keel, being bent in their passage over the median keel, giving them an angularly flexuous appearance (Fig. 15). There are strongly marked varices on some of the shells. ‘The wing is shorter, broader and stronger, but when perfect is always produced in an acute, upward point: at the point of curvature it is broad, with even, though very rarely, a tendency to become bifurcated (see Fig. 16). The aperture is the same as in the Folkestone shells, but the anterior canal is never long. These differences would be by many, as they have been by Prof. Morris and others, considered sufficient to constitute the Blackdown fossils into a separate species ; but frequent examination of a large series of specimens has convinced me that they cannot he so sepa- rated, as I am utterly unable to find any fixed specific character by which to distinguish them; the more ordinary forms of this shell from both localities being all but identical with each other. I shall allude farther on again to these differences, and hope to offer some explanations which may help to account for them. Distribution.—It is exceedingly abundant both at Folkestone and Blackdown, and not uncommon at Shanklin. On the Continent it is found at Ervy, Courtaout, Dienville, Cosne, etc., and specimens may be seen in most museums. History.—Parkinson first figured this species as a Rostellarite in the Organic Remains, vol. iii. p. 63, pl. v. fig. 2. Sowerby in the Min. Conch. vol. iv. p- 69, pl. 349, fizured and described it very carefully, naming it R. calcarata; and D’Orbigny in 1842 gave an enlarged figure of this shell from the Gault of Ervy, Pal. Fr. Terr. Crét. pl. 207, fig. 3. I am not quite certain whether the figures and descriptions of A, Muleti, composita, ete., of other authors are identical with our Species, as their shells are considerably larger, specimens in the ' Mr. Ralph Tate, Geol. and Nat. Hist. Repertory, Sept. 1865, named this variety “neglecta.” DECADE II.—yYVOL. II.—NO. II. 9 130 Reviews—Page’s Economic Geology. Vienna and Dresden Museums being an inch long. Those from Blackdown seem occasionally to have attained a greater size, but never approaching the size of the EKuropean forms just mentioned. It is the smallest Aporrhais of the group. The following allied forms are figured in various works, but their identity with A. calcarata of Sowerby is uncertain, and they seem to be intermediate between this form and A. carinata. R. stenoptera, Goldf. Greensand, Aachen. R. Buchii, Minst., Geinitz. ? R. calearata (Sby.), Geinitz, Reuss. Zekeli. R. composita, Leymerie. A, Muleti, D’Orb., Pictet and Campiche. J. Miiller, in the Monogr. der Petrefacten des Aachen Kreidefor- mation, figures a remarkable assemblage of Aporrhaides that are near to A. calcarata, but some with monstrous forms of wing, see especially Str. arachnoides, figured by Geinitz in his Quadersand- steingebirge, tab. ix. f. 5. They are:—R. minutia, R. arachnoides, fi. granulosa, R. furca, BR. Nilssont. EXPLANATION OF PLATE Y. Fie. 1.—Aporrhais carinata, Folkestone. Fullgrown. From the author’s cabinet. N.B.—The spiral angle is apparently increased, owing to the specimen being slightly flattened. Fic. 2.—A. elongata, Folkestone. Fic. 2a.—Portion magnified. Both from the author’s cabinet. Fic. 3.—Spire of A. elongata. From Mr. Price’s collection. Fic. 4.—A. maxima, Folkestone. From a fragment in Mr. Price’s collection. Fie. 5.—A. carinella, Folkestone. Ventral side of a full-grown specimen. Fic. 6.—A. carinella. Dorsal view of another specimen. Fic. 6a.—A portion magnified. Both from the author’s cabinet. Fie. 7.—A. calearata, specimen from Blackdown, showing varices. In the Brit. Mus. Fic. 7a.—Portion enlarged. Fic. 8.—Specimen with faintly marked ribs. In the British Museum. Fic. 8¢.—Same, enlarged. Fic. 9.—A pupeform specimen. In the British Museum. Fie. 10.—Specimen from Folkestone, from an Upper Bed of the Gault. In the author’s cabinet. Fics. 11, 12, 13.—Specimens from the usual Lower Bed, Folkestone. From the same. Fic. 13a.—Same, enlarged. Fre. 14.—A specimen from the same, enlarged twice. In the British Museum. Fic. 15.—Specimen from Blackdown strongly ribbed. In the British Museum. Fic. 15¢.—Same, enlarged. Fic. 16.—Specimen with bifurcated wing from Blackdown. In the Brit. Museum. (To be continued in our next Number.) dy day We JE Jah WW Se I.—EKconomic GEroLocy; or, GEOLOGY IN ITS RELATIONS To THE ARTS anp Manuractures. By Davin Pacr, LL.D. 8vo. pp. 886. (Edinburgh and London: Blackwood and Sons, 1874.) T has been said that the ultimate aim of geological inquiry is to restore in imagination the physical geography of by-gone periods ; to restore, however dimly, the former extent in different times of land Reviews—Kinahan’s Valleys, ete. 131 and water; and to picture the forms of animal and vegetable life that have from time to time existed. But there is another, and perhaps to the majority of mankind, a higher aim in Geology, one that also leads to noble thoughts and lofty aspiratioas—sometimes also to the realiza- tion of large fortunes—the study of Economic Geology. The application of Geology to the Arts and Manufactures has been brought prominently before us by Professor Ansted in several published works. They have been illustrated in the Museum of Practical Geo- logy, and special branches of the subject have been treated of in works by Prestwich, Hull, Smyth, and many others, as well as in the Reports of some of our Royal Commissions. The connexion between Geology and other sciences is as much displayed in its economic bearings as in its purely natural history relations. Dr. Page has produced a very comprehensive work. The relations between Geology, Agriculture, and Land Valuation are discussed, likewise those in connexion with Architecture, Civil and Mine Engineering. One chapter is devoted to Heat and Light producing materials; and another to Geology and the Fictile Arts, treating of the Clays we fabricate, the Sands we vitrify, and Glazes, Enamels, and Colours. Chapters are devoted to Grinding, Whetting, and Polishing Materials; to Refractory or Fire-resisting substances; to Pigments, Dyes, and Detergents; to Salts and Saline Earths; to Mineral and Thermal Springs; to Mineral Medicines; to Gems and Precious Stones; and, lastly, to the Metals and Metallic Ores. At the end of each chapter Dr. Page has enumerated some of the most important works that may be consulted when details on particular subjects are required. na work of so comprehensive a kind as this, it is impossible not to find some subjects which appear to be rather scantily treated. We might have expected some particular notice of Trish peat, or a reference to the localities in England where it has been dug. The ages and modes of occurrence of the clays we fabricate are hardly noticed at all. But we must not forget the cosmopolitan nature of the work, and that the addition of much more material would have rendered it too bulky for a Text-book. We may congratulate Dr. Page in having produced this book, which cannot fail to be very largely and widely appreciated. IJ.—Vatirys AND THEIR ReLatTion To Fissures, FRACTURES, AND Fauuts. By G. H. Kinanan. 8vo. pp. 240. (London: Triibner & Co., 1875.) Glee who have been spectators of the course of Geological Theory during the past ten or fifteen years must have been struck by the many, seemingly one-sided, explanations that have been given to account for the origin of the present land configuration. The early teachings of Hutton, and of Scrope, have perhaps been more fully appreciated in late years than they were fifty years ago. The effects of rain and river action have been more fully explained, and the great influence of glacial action in comparatively recent times has been also taken into account. Nor has the agency of the sea been neglected, although it has been clearly proved that meteoric agencies combined, by reason of the greater surface they have to act upon, far 182 Reports and Proceedings— exceed in destructive power the influence of oceanic waves and currents. It may be fairly questioned, however, whether some observers have given due credit to all denuding agencies, in their explanations of the origin of scenery; or whether they have adequately appreciated the effects of forces apart from those of denudation. If we cannot follow the Duke of Argyll in all his interpretations of geological phenomena, we can yet be thankful for the words of caution he has given in his eloquent writings. There is no doubt that ice, rain, rivers, and sea have performed the denudation. The question is, how far have other agencies directed their action ? In the work before us Mr. Kinahan has endeavoured to demonstrate that, in general, valleys are connected with faults or breaks, and that a valley or hollow could seldom have been carved out unless there were cracks, minor joints, or other shrinkage fissures, in which one or other of the different denudants could work, He very fairly acknowledges that meteoric abrasion (or sub-aerial denudation) seems to be the most universal performer in the great work of denudation, but that without the aid of faults and joints, few valleys could have acquired their present form. The fact that internal forces of disturbance may have ceased to act long before present surfaces were formed, does not affect the question of their influence. The author points out the relations existing between breaks, faults, and lake-basins, particularly in Ive- land; nevertheless, ice-action and meteoric abrasion have been the denudants, while the situation and shape have been influenced by the earlier forces. Although objections may be taken to some of Mr. Kinahan’s con- clusions, yet on the whole his book is a valuable addition to the litera- ture of Physical Geology. The majority of the facts stated are from the observations of himself and his colleague the late Mr. Warren on the Geological Survey in Ireland, and it is such experience gained by detailed investigations that must always form the basis of our theories, especially when taken in conjunction with the sats observed in different parts of the world. IS PMI ys) CNIS—D) JE ssSY(Oe Aa BAS sLIN (ES ————— GeroLogicaL Socrety or Lonpon.—I.—December 16, 1874.—John Hvans, Esq., F.R.S., President, in the Chair.—The following com- Bes were read :— “Descriptions of the Graptolites of the Arenig and Llandeilo en of St. David’s.” By John Elojpistaoin Esq., F.G.8., and Charles Lapworth, Esq., F.G.S. Commencing with -a brief historical account of the discovery of Graptolites in the neighbourheod of St. David’s, from their first ~ discovery in the Llandeilo series in 1841 by Sir Henry de la Beche and Professor Ramsay, the authors proceeded to explain their views on the classification of the Graptolites (Graproniruina, Bronn), which they place under the order Hydroida, dividing them into two groups, RuasppopHora (Allman), comprising the “true siculate or virgulate Graptolites, which they consider to have been free or- ganisms, and CxapopHora (Hopkinson), comprising the dendroid Geological Society of London. 133 Graptolites and their allies, which were almost certainly fixed, and are most nearly allied to the recent T’hecaphora. The distribution of the genera and species in the Arenig and Llandeilo rocks of St. David’s was then treated of, and the different assemblages of species in each of their subdivisions were compared with those of other areas. The Arenig rocks are seen to contain a number of species which ally them more closely to the Quebee group of Canada than to any other series of rocks, all their subdivisions containing Quebee species, while the Skiddaw Slates, which before the discovery of Graptolites in the Lower Arenig rocks of Ramsey Island in 1872 were considered to be our oldest Graptolite-bearing rocks, can only be correlated with the Middle and Upper Arenigs of St. David’s. The Graptolites of the Arenig rocks of Shropshire and of more dis- tant localities were also compared with those of St. David’s. In the Llandeilo series of this district the Cladophora have now for the first time been found, a few species, with several species of Rhabdophora, occurring at Abereiddy Bay in the Lower Llandeilo, which alone has been carefully worked, there being much more to be done in the Middle and Upper Llandeiio, from which very few species of Graptolites have as yet been obtained. Some of the recently introduced terms, and altered or more definite terminology, employed in the descriptions of the species were then explained ; and the paper concluded with descriptions of all the species of Graptolites collected in the Arenig and Llandeilo rocks of St. David’s within the last few years of which sufficiently perfect specimens have been obtained, doubtful species being referred to in an appendix. Forty-two species were described belonging to the following genera :—Didymograptus, Tetragraptus, Clemagraptus (gen. nov.), Dicellograptus, Climacograptus, Diplograptus, Phyllograptus, Glosso- graptus, and Trigonograptus (Rhabdophora) ; Péilograptus, Dendro- graptus, Callograptus, and Dictyograptus (Cladophora). Discusston.—Mr. Carruthers said that this paper greatly added to our know- ledge of the Graptolites. He had doubts as to the true position of the Cladophora. Of the Rhabdophora the later forms seemed to be simpler in their structure than the earlier ones. Mr. Hicks stated that the branching forms occur in the lowest part of Ramsey island, together with the dendroid forms. Prof. T. Rupert Jones inquired whether, if it were true that the later forms of Graptolites were simpler than the older ones, we may regard this as due to a de- generation leading towards an extinction of the type. Mr. Hopkinson, in reply, stated that the dendroid forms are only known to occur in abundance in Britain in the Arenig rocks of St. David’s; and that there are here intermediate forms connecting the British and American species which occur in rocks of more ancient age. He remarked that he did not consider the dendroid forms valuable for determining zones, species very nearly allied to those of the Arenig rocks being met with even in the Lower Ludlow rocks of Shrop- shire ; but the Rhabdophora occur only in small zones, and wherever they are found, they seem to hold an equivalent position. They are consequently valuable for stratigraphical purposes. Mr. Hopkinson stated that in recent deep sea dredgings Hydroids had been found approaching the Graptolites in structure, and that Graptolites have also lately been discovered which have many points in ‘common with the recent sertularian Zoophytes. 134 Reports and Proceedings— 2. “On the Age and Correlations of the Plant-bearing series of India, and the former existence of an Indo-Oceanic Continent.” By H. F. Blanford, Esq., F.G.S. In this paper the author showed that the plant-bearing series of India ranges from early Permian to the latest Jurassic times, indi- cating that, with few and local exceptions, land and freshwater con- ditions had prevailed uninterruptedly over its area during this long lapse of time, and perhaps even from an earlier period. In the early Permian there is evidence in the shape of boulder-beds and breccias underlying the lowest beds of the Talchir group of a pre- valence of cold climate down to low latitudes in India, and, as the observations of geologists in South Africa and Australia would seem to show, in both hemispheres. simultaneously. With the decrease of - cold the author believed the Flora and Reptilian Fauna of Permian times were diffused to Africa, India, and perhaps Australia; or the Flora may have existed somewhat earlier in Australia, and have been diffused thence. The evidence he thought showed that during the Permian epoch India, South Africa, and Australia, were con- nected by an Indo-oceanic continent, and that the first two re- mained so connected, with at the utmost some short intervals, up to the end of the Miocene period. During the latter part of the time this continent was also connected with Malayana. The position of the connecting land was said tobe indicated by the range of coral reefs and banks that now exist between the Arabian Sea and West Africa. Up to the end of the Nummulitic epoch, except perhaps for short periods, no direct connexion existed between India and Western Asia. DIscussIon.—Prof. Ramsay said that he thought the age of the different beds re- ferred to had been correctly determined by the author. He doubted whether there was any great difference between the Permian and the Triassic deposits. ‘He referred to the time when the possibility of the occurrence of glaciation in Permian times was doubted, but erratic boulder-beds of undoubtedly Permian age had since been described as occurring in South Africa, and he thought there was a general tendency to admit the possibility of Permian glaciation. He remarked that, according to Mr. Croll, glacial periods occur at intervals, alternating on the northern and ‘southern hemispheres every 25,000 years. The south is now under more glacial conditions than the north, and during the formation of our Boulder-clay the southern hemisphere had a more temperate climate. Prof. Ramsay agreed with the author in the belief of the junction of Africa with India and Australia in geological times. Prof. T. Rupert Jones said that he wished to express his high appreciation of the masterly summary of the facts and theories relating to the wide extension of the early Mesozoic fauna and flora given by Mr. Blanford in this paper, and supple- mented by the results of his own personal observations on the Geology of India. He referred to the still stronger evidence which the Karoo beds would probably afford when their reptiles shall have been all worked out. Their Palzoniscan fishes would form no exception to their Mesozoic character, as Palgonzscus occurs in the English Trias. The conglomerate bed at the base of the Karoo, though described as glacial in Natal, presents peculiarly volcanic characters in other parts of South Africa. Referring to the occurrence of a Labyrinthodont in Australia, Prof. Jones dated the rise of the inquiry into the extent of Mesozoic land in the Southern hemisphere from Prof. Huxley’s notice of this and other Amphibians and his own observations on the range of Zstherig. He thought that the Mesozoic plant-bearing and reptiliferous beds of Carolina and Virginia had very similar relations to those mentioned in the paper. In conclusion he referred to the more Geological Society of London. 135 recent glaciation of South Africa described by Mr. Stow, and also to Mr. Belt’s popular exposition of the hypothesis of bipolar glaciation, and suggested that the earth’s passing through cold stellar spaces might perhaps be the real cause of glacial epochs. Mr. Drew wished to know what were Mr. Blanford’s views as to the land from which the river came that deposited the strata with which the plant-remains were associated. With such great thicknesses as I1,000 and 15,000 feet of fluviatile beds, the occurrence of which implied a corresponding amount of sinking, there must, he thought, at one time have been very high land, which was thus drained and denuded. He inquired what portion, if any, of this land now remains. Mr, Carruthers said he thought that in South Africa there are four distinct plant- beds, and that the. base-bed is higher than the Permian, belonging to the Jurassic series, and probably to the Oolite. Mr. Woodward was pleased to find that the author had added further evidence, derived from the fossil flora of the Mesozoic series of India, in corroboration of the views of Huxley, Sclater, and others as to the former existence of an old sub- merged continent (‘‘ Lemuria”), which Darwin’s researches on coral reefs had long since foreshadowed. Mr. Blanford’s observations on the former existence of glaciers at much lower levels than the present snow-line of India added another valuable piece of evidence to those collected by Mr. T. Belt in Nicaragua and elsewhere. But any theory pretending to account satisfactorily for the glacial epoch must not only explain the lower level of former glaciers in the tropics, but the former existence of a warm, temperate, and even subtropical fauna and flora in high northern latitudes, as shown by Heer, McClintock, and others, not to be provided for by Croll’s theory or that of Balfour Stewart, but by periodic variation in the inclination ‘of the earth’s axis, as suggested by Belt, and long since by the Rey. Prof. Haughton in the Society’s Journal. Mr. Bauerman considered that the author’s conclusions were, in the main, borne out by the evidence afforded by those portions of the Indian coal-fields with which he was acquainted. He thought, however, that there was a difficulty in the precise correlation of the Coal-bearing series of Western India with those of Bengal, owing to the absence of the best physical horizon in the Ironstone series in the western district. From what he had seen of the Talchir section in the Nerbudda valley, he was not inclined to agree with the author as to their glacial origin ; but he was not acquainted with the other section referred to in the Godavery valley. He con- sidered that the author’s conclusion as to the age of the volcanic series of the Deccan was confirmed by the evidence of rocks of similar character occurring in Eastern Africa on the south side of the Gulf of Aden. Dr. Murie thought the evidence derived from the living forms of animals was in favour of their migration to or from Africa through Arabia, but not by way of the Maldive group. The author, in reply, remarked that the ancient continent would not furnish glaciers unless it was of very great height. He suggested that the boulders referred to might have been due to the action of winter ice. IJ.—January 13, 1875.—John Evans, Esq., F.R.S., President, in the Chair. The following communications were read :— 1. ‘‘On the Kimmeridge Clay of England.” By the Rev. J. F. Blake, M.A., F.G.S. The author described in considerable detail the development of the Kimmeridge Clay in various parts of England, dwelling especially upon the paleontological phenomena presented by it in the different locali- ties. He arrived at the conclusion that the Kimmeridge Clay in Eng- land is divisible only into two sections, Upper and Lower; but when it is preceded by the Coral Rag, it possesses a basal series of no great thickness, which may be designated the Kimmeridge Passage-beds. He compared his Upper Kimmeridge with the lower part of the ‘ Vir- gulien”’ with foreign authors. It consists of paper shales, paper slabs, bituminous shales, and cement stones, with interstratified clays, and may attain a thickness of at least 650 feet. Its fauna is characterized 136 Reports and Proceedings— by paucity of species and great abundance of individuals. It is thickest in Dorsetshire and Lincolnshire, but thin or absent in the inland counties. The author stated that no Fauna comparable with that of the Middle Kimmeridge or ‘‘ Ptérocerien”’ has been discovered in Eng- land, though some of its less characteristic fossils occur. associated with Lower-Kimmeridge forms. The Lower Kimmeridge is a mass of blue or sandy clay, with numerous calcareous ‘‘ doggers,” largely developed in Lincolnshire, the whole representing the ‘‘ Astartien”’ of foreign geologists. Its thickness is estimated at from 300 to 500 feet in Ring- stead Bay, and. about 400 feet in Lincolnshire. The fossils of the Coral Rag extend up into the Kimmeridge passage-beds, which are typically developed at Weymouth, where they are about 20 feet thick. Discuss1on.—Prof. Seeley complimented the author on the elaborate paleeonto- logical details which he had correlated in his paper. He noticed that the Kim- meridge Clay is thinnest in the neighbourhood of Ely, and thickens to the north, in Lincolnshire, and also southward, and that this southward thickening is con- comitant with a development of sandy beds at the base and less markedly also at the top. As the formation is traced into France by way of Boulogne, the sandy characters become more strongly marked, and eventually the deposit can no longer be recognized as a Clay, though westward, at Havre, it is as much a clay as at Weymouth. He then called attention to the fact that in France there is a large curve of igneous rocks, roughly parallel to the present out- crop of the English Secondary strata, partly broken through by a mass of Palzeozoic rocks, extending northward from Strasburg through Belgium, and by way of Harwich towards the Cambridgeshire area. He thought that the denuda- tion of these deposits probably furnished the materials of the southern portion of the beds under consideration ; and if so, the stratigraphical sequence becomes in- telligible in this way,—the Kimmeridge Grit, being sandy, resulted from an eleva- tion of this igneous curve, and the mass of the Kimmeridge indicated that the curve was depressed so that the sand did not reach the British area, while the covering sand shows that it was again upheaved. The bottom sand is in physical con- tinuity with the upper Calcareous Grit, and the upper sand is similarly continuous with the Portland Sand, so that he doubted whether any portion of the series is really wanting in England. 2. “Note on VPelobatochelys Blaket and other Vetebrate Fossils obtained by the Rev. J. F. Blake from the Kimmeridge Clay.” By Harry Govier Seeley, Esq., F.L.S., F.G.S., Professor of Physical Geography in the Bedford College, London. The author stated the fossils referred to in his paper gave evidence of three species of Jchthyosaurus (one larger than any previously known to occur in the formation), a Pliosaurus, a Stenecosaurus, a small Ornithosaurian, and a species of Chelonian, which he described under the name of Pelobatochelys Blaket. The remains of this animal indicated a carapace sixteen inches long by fourteen inches broad, and angularly arched posteriorly. The pygal scute was divided as in Emys, and the hinder margins of the vertebral scutes were elevated as in some species of Batagur. The vertical scutes were nearly twice as broad as long, and interlaced with each other by sawlike margins. The costal plates were imperfectly ossified. 3. ‘On the Cambridge Gault and Greensand.” By A. J. Jukes- Browne, Esq., F.G.S. This paper has for its object to determine the true position of the Cambridge nodule-bed in the Cretaceous series, and to investigate the nature and origin of its peculiar fauna. Geological Society of London. 137 The first part of the paper deals with the stratigraphical relations of the beds; and the author calls attention to the fact that in the numerous artificial sections near Cambridge only two formations are really visible, viz. the Chalk Marl with a pebble-bed of phosphatic nodules at the base, and the stiff dark clay of the Gault, upon which these rest. ; The so-called Greensand or nodule-bed passes up into the Chalk Marl, but rests unconformably on the Gault below, which presents in fact a surface of erosion; and there is therefore a break of indefinite length between the Cambridge Gault and Greensand. The nodule-bed continues to present much the same characters and fossils through Bedfordshire as far as Sharpenhoe, a village about three miles east of Harlington, on the Midland Railway. Here is situated the most westerly coprolite pit or working in the Cambridge bed; and beyond this the Gault passes into Chalk Marl without any such seam intervening. ; It is not until we enter Buckinghamshire and reach Buckland near Tring, that anything like true Upper Greensand appears, and separates the Chalk Marl from the Gault. From this point westward the formation increases in thickness and importance, but its characters and fossils are quite different from those of the Cambridge Greensand. Although in Bucks no coprolites are found between the Gault and Greensand, yet they occur in the Gault itself; and one bed may be traced towards the N.E., and is found to commence where the Cam- bridge nodule-bed ends, thereby raising the presumption that it becomes confluent with that bed, and has furnished many of the well- known fossils and nodules it contains. A consideration of these facts warrants the following general con- clusions :-— 1. That the Cambridge Greensand or nodule-bed has no connexion with the Upper Greensand, its actual position being at the base of the true Chalk Marl. II. That the same bed rests unconformably on the clay below, and that its coprolites and fossils have been derived from the Gault. III. That in consequence of this erosion a great gap now exists in Cambridgeshire between the Lower Gault and the Chalk Marl, the whole of the Upper Gault and Upper Greensand being absent. _ The paleontological evidence leads to exactly the same conclusions. The fauna is divisible into two groups, and the fossils belonging to the one are preserved in dark phosphate, and being generally water- worn are clearly derived forms, while the others are of lighter colour, and belong to the deposit. The former group is chiefly composed of Gault species, seventy per cent. of which belong to the upper stage of that formation; while the fossils proper to the deposit are also found in the Chalk Marl above. The author therefore feels justified in concluding that strati- graphically the bed is Chalk Marl, while paleontologically considered its fauna is mainly derived from the Upper Gault. Discussion. —Mr. Charlesworth considered that the vexed question of the true re- lations of the so-called Upper Greensand of Cambridge had been now determined, and that it must beregarded as Gault. The presence of Exdogenites erosa and other Wealden forms in the deposit at Potton in Bedfordshire, would seem to show that 138 Reports and Proceedings. it belonged to the Wealden ; while the presence of Kimmeridge species might be taken to prove that it was Kimmeridge. With regard to the so-called coprolites, he remarked that it was difficult to assign those of the Red Crag, as well as those of Cambridge, to their true position. He inquired how did the phosphatic nodules originate? Some observers maintain that they are rolled, but in the Crag the . sharks’ teeth have nodules attached to their base, and these could not have been acted upon by erosion. He thought the phosphates were derived either from decomposed marine vegetation or from excrements. Mr. Price remarked that he had examined 75 or 80 species of fossils from the Cambridge deposit in the Woodwardian Museum, and found that 33 per cent. of them pertained to the Upper Gault. Prof. Seeley remarked that when he commenced the study of the question dis- cussed in Mr. Jukes-Browne’s paper, the fossils of the so-called Cambridge Upper Greensand were very imperfectly known, and the prevalent belief among palzon- tologists was that the stratum represented the Gault. As the collections at Cambridge were accumulated, and his acquaintance with English sections of similar deposits was enlarged, he had enjoyed opportunities of discussing the question with foreign palzeontologists, and now believed that the deposit essen- tially represented the English Upper Greensand. He had noticed that the surface of the Gault on which the Greensand rests is eroded, the phosphatic nodules being spread uniformly, though the Vertebrate fossils were often contained in hollows of the surface of the Gault. Occasionally the phosphatic bed was covered by a dis- continuous dark-coloured clayey bed, divided from the Chalk Marl by a sharp line of bedding. He thought that this band might result from denudation of Gault, and the fact that it did not interfere with the continuity of the bed of phosphatic nodules seemed to show that the denudation was local and of small extent. The fact that sand was superimposed upon clay, necessarily implied an upheaval of the sea-bottom, and therefore the newest-formed beds of the Gault were sure to be denuded to some extent in consequence. But while this circum- stance would explain the occurrence of a small per-centage of Gault species, it rendered it rather improbable that so varied a fauna should have been derived from a denuded portion of one stratum. Mr. Seeley’s own investigations had not led him to detect in the bed any preponderance of Gault forms. He further found that the remains of Vertebrates in the Cambridge Upper Greensand were associated series of bones, which would not be the case were they derived fossils, and that no species of reptile had yet been identified as common to the Cambridge Greensand and the Gault. He thought that the thinness of the Cambridge Greensand, as well as the complex nature of its fauna, was only to be understood by considering the circumstances of physical geography under which the deposit originated ; and upon this some light was thrown by the thinness of the Kimmeridge Clay in the same area, and by the occurrerce of phosphatic nodules in that area in the so- called Neocomian beds. These beds, like the Cambridge Greensand, contain fossils derived from the Carboniferous Limestone and fragments of Paleozoic rocks, so that the phosphates might have been furnished to the sea in which the deposit was formed by denudation of eruptive dykes of apatite, such as Mr. D. Forbes had informed him were to be met with traversing Paleeozoic rocks in Spain, Norway, and other countries. Taking all these facts into consideration, he was inclined to hesitate for the present in accepting Mr. Jukes-Browne’s hypothesis. Mr. Forbes, with reference to Mr. Seeley’s observations, stated that he had found true eruptive lodes or dykes of phosphate of lime (phosphorite or apatite) traversing the Silurian and Devonian strata and granites of Estremadura in Spain and Portugal, and often extending for miles ; and also others breaking through the metamorphic schists of the south of Norway. Some years back he had explained the phosphorite in the deposits of Nassau as resulting from submarine eruptions, which brought it up and left it on the sea-bottom in the form of breccia and tuff, precisely as a volcanic rock would do under similar circumstances. So far as he had examined the phosphatic nodules of the Cambridge Greensand, however, he had not found that their mineral structure indicated any such eruptive origin. The Rev. T. G. Bonney remarked that Mr. Seeley’s observations bore upon a large question, affecting our whole system of geological nomenclature rather than the immediate subject. The nomenclature being as it was, he thought Mr. Correspondence—E. B. Toavney. 139 Browne was fully justified in his conclusions. In the Cambridge deposit we have two distinct faunas ; one, as shown by per-centages, related to the Chalk Marl, the other to the Upper Gault; two conditions of mineralization; evidence of erosion in the irregular junction of the two beds, in the waterworn condition of many of the nodules, in the fact that they had PZcazzle, Polyzoa, etc. attached ; the nodules also could be detected in the Gault, not only in the particular seam which had been described, but at intervals throughout the mass ; also erratics of some size occurred in the phosphate bed. These facts, he thought, proved the existence of a break. He. thought that associated bones were rarer than Mr. Seeley described them to be. It appeared to him that some of the speakers had forgotten that the question of the origin of the nodules had already been brought before the Society by Mr. Sollas and Mr. Fisher, who have shown very many of them to be phosphatized sponges. ; Mr. Whitaker, from his experience in mapping the Geology of the Cambridge district, came to the conclusion that the bed is really the base of the Chalk Marl, there being a regular passage up inte the latter. He questioned whether the Upper Greensand is a separate formation. p Mr. Hawkins Johnson said that the microscopical structure of the phosphatic nodules is identical with that of septaria from the London Clay, with that of the Clay-ironstone nodules of Yorkshire, and with that of some septaria from the Kimmeridge Clay. Moderately thin sections subjected to the action of dilute acid (even acetic acid), and examined while moist, show a structure like that of sponge. The President remarked that the difference between Mr. Jukes-Browne and Mr. Seeley appeared to be ona question of fact. He remarked upon the dif- ficulty of distinguishing between the Chalk and the Upper Greensand. : The Author, in reply, said that he was only concerned with the question of where the coprolites had come from, and not that of how they originated ; he had not therefore touched upon the formation of phosphatic nodules. He thought Mr. Seeley had admitted some of the most important points of his paper, viz. the eroded surface of the Gault, the confluence of the Cambridge nodule-bed with that of the Gault, and the consequent derivation of many of its fossils. He must, however, maintain that there was a complete passage between the Greensand and the Marl above, and no trace of a second line of erosion, as Mr. Seeley appeared to think. With regard to the vertebrate remains, those preserved in dark phos- phate were always worn and rolled, while the associated bones Mr. Seeley spoke of were light in colour, and undoubtedly belonged to the formation itself, z.e. to the base of the Chalk Marl. Lastly, the lists and per-centages contained in the paper would show whether or not there was a preponderance of Gault forms in the deposit, and the author was quite prepared to abide by observed facts and palzontological results. ; CORRESPONDENCE. — ON THE CRETACEOUS APORRHAID ZA. Sir,—In the February Number, your contributor, Mr. J. Starkie Gardner, writing on Aporrhais retusa, Sow., says, “‘ 1 cannot find the type or any specimen from Blackdown, and there is a doubt whether the same species is intended.” ‘It is curious that he should appar- ently not have read page 239 of Fittou’s memoir, where it is stated that his types belonged to the Bristol Institution, and are “now in the Museum of that establishment.” (See also Proc. Bristol Naturalists’ Soc., vil. pt. 2, p. 41.) In the Catalogue of Blackdown Fossils, pp. 289-242, Fitton is very careful to indicate against each species the collection in which the specimens may be found. Your contributor also writes, “Should the Blackdown form prove distinct, Deshayes’s name of bicarinata must be adopted for it.” We should 140 Correspondence—H. W. Bristow. . claim priority for the Blackdown type ; and in case of non-identity, it is the Gault form rather to which the French author’s name may be apportioned. However, I have little doubt but that they are one and the same species. The single specimen, imperfect as to the digits, from which J. Sowerby drew up his description, seems to me to agree precisely with the Folkestone forms, except that the keels are a little less pronounced; but this is evidently due to the somewhat toned-down state of the specimen; there are seven to eight threads above the keel, and four between the keels, of which the two central are a little stronger than the remaining two. The surface, instead of being “particularly smooth,” as Sowerby says, I should describe as showing traces of oblique cross lines, which have become very obscure through abrasion. I regret that I am unable to com- pare it with the foreign descriptions, but the Museum is quite without the necessary books. Bristot Musrvm, H. B. Tawney. February 18th, 1875. DEEP BORING IN PRUSSIA. Srr,—The experimental boring at Sperenberg having revealed the existence of a deposit of rock-salt, greatly exceeding that of any previously known, I send you some further details, for which I am again indebted to Professor A. von Koenen, of Marburg. The boring was begun in gypsum, probably belonging to the Mus- chelkalk. As the boring proceeded, the gypsum was found to become gradually mixed with Anhydrite, and then te pass into pure Anhydrite. Still lower, a little rock-salt was met with; and afterwards at 88:8 metres (2914 KHnelish feet) pure rock-salt, in which the boring continued down to 1271°63 metres (4171 English feet); no other rocks besides gypsum and salt having been met with. - Two other borings, at some distance from the first, have reached the rock-salt at 120°6 and 115°8 metres respectively, or at 3954 and 880 English feet. Prof. von Koenen recommends English geologists, who take an interest in the subject of the increase of the Harth’s temperature in proportion to depth, to consult the papers of Obergrath Dunker in that volume of the “‘ Zeitschrift fiir das Berg- Hiitten- und Salinen-Wisen in dem Preussischen Staate,” which contains an account of the boring, viz. vol. xx. (1872). The reduction of Prussian into English feet being incorrect in my former letter, I avail myself of this opportunity of rectifying the mistake: 85, 100, 8633, 956, 8095, and 4051°6 Prussian feet are equal to 873, 108, 374, 9832, 31842, and 41724 English feet respectively. The average cost of sinking, therefore, amounted to about £2. 1s. 9d. per foot English. 28, JERMYN STREET, H. W. Bristow. February, 1879. Correspondence—G. H. Kinahan. 141 MR. CROLL ON THE OSCILLATIONS OF THE SEA-LEVEL DUE TO THE ADVANCE AND RETREAT OF THE ICE CAP. Srr,—In my recently published book on “ Valleys and their Rela- tions to Fissures, Fractures, and Faults,” in a foot-note on page 182, I refer to Mr. Croll’s paper “On the Glacial Epoch” [Guon. Mae. July and August, 1874], and point out that the oscillations in the sea-level “will account for the very uniform altitude of the ancient sea-beaches.” As this note was added at the last moment, just previous to the book issuing from the press, it necessarily is not so explicit as it might be, and I find it has been taken exception to. Will you therefore allow me, through the medium of the Guot. Mae., to supplement the note ? Although I believe Mr. Croll’s theory to be correct, and that the sea in general rose and fell while the land for the most part re- mained comparatively stationary, yet I do not for a moment imagine that there were no oscillations of the land. On the contrary, such movements are proved in Ireland, as I have shown in different papers on its geology. Take, for instance, the margin and gravels of the “‘Hsker Sea,” which in some districts are at higher altitudes than in others. There are also the post-Drift faults, some being more recent than our newest Drift, which could not possibly have been formed without greater or less changes in the level of the land. Such changes in the level of the land do not seem to be denied by Mr. Croll, neither to me do they appear to affect his theory; as they, with a few exceptions, are mere bagatelles compared with the universal oscillations in the sea-level. G. H. Krnanan. IMEI S\ Gabe Aap sHOn eS —_—_—_@—___ Puiniips’s GEoLocy or YorKsHrre.—Subscribers to the new edition of the late Professor Phillips’s ‘‘ Geology of Yorkshire,” Part 1, “The Yorkshire Coast,” will be glad to hear that it has been placed in the hands of Mr. Robert Etheridge, F.R.S., F.G.S., and is now nearly com- pleted; the last proof-sheets having been revised and the new map and plates nearly all coloured. It is hoped that by April the Professor’s earliest and latest work will be issued. Tue Bustr Merzorrre.—Apropos of the ‘‘ Chapter in the History of Meteorites” now appearing in this Macazrnz, Dr. Flight desires us to state that, since the publication of the January Number, he has ascer- tained that a preliminary note on the Calcium Sulphide of the Busti aerolite, mentioned on page 16, was published in the Brit. Assoc. Reports, 1862, ‘ Notes and Abstracts,’ Appendix ii., page 190.— Enprr. Got. Mae. Votcanic Eruption 1n Java.—‘ Toe Hacour, Fzs. 3, 1875.—The Government has received a despatch from Batavia, of to-day’s date, announcing an eruption of the volcano Kloet, in the island of Java, whereby great destruction has been caused at Blitar.” 142 Obituary—Sir Charles Lyell. QspSa PIP OIINASS SS — SIR GEARS LYELL BART. M.A., D.C.L., LL.D., F.R.S., F.L.S., V-P. GEOL. SOC. LOND. On Monday, 22nd February, at his residence in Harley Street, and in his seventy-eighth year, Sir Charles Lyell passed peacefully from amongst us, after a long life of scientific labour, _ to his honoured rest. To the outside world it may seem strange that the death of aman who was neither statesman, soldier, nor public orator, should arouse our sympathies so strongly, or that he should be so highly esteemed all over the world ;. but geologists know well what Lyell has done for them since he published the first volume of “The Principles of Geology ” in 1880. It is in the character of historian and philosophical expo- nent of geological thought that Lyell has achieved so much for our science; nor can we fail to remember that those clear and advanced views, for which he became so justly celebrated, were advocated by him forty-five years ago, at a time when scientific thought was still greatly trammelled by a strong religious bias, and men did not dare to openly avow their belief in geological discoveries nor accept the only deductions which could be drawn from them. It was no small service which Lyell rendered to us when he publicly maintained that, in reasoning on geological data, it was impossible to restrict geologists to the limits of the Mosaic cosmogony, or to adopt for the past ages of geological time the chronology of Archdeacon Ussher. Born at Kinnordy, his father’s seat near Kerriemuir, in Forfarshire, on the 14th of November, 1797, Lyell received his early education at a private school at Midhurst, and com- pleted it at Hxeter College, Oxford, where he took his Bachelor’s degree in 1819, obtaining a second-class in Classical honours in the Easter Term. On leaving the University, he studied for the Bar, but never practised that profession, his tastes having been led by Dr. Buckland’s lectures to the study of Geology as a science. In 1824 he was elected an Honorary Secretary of the Geological Society of London, of which he was one of the earliest Fellows. On the opening of King’s College, London, a few years later, he was appointed its first Professor of Geology. He had already contributed some im- portant papers to the “ Transactions” of the Geological Society, including one “Ona Recent Formation of Freshwater Limestone in Forfarshire, and on some Recent Deposits of Freshwater Marl, with a comparison of recent with ancient Freshwater Formations, and an Appendix on Gyrogonites, or Seed Vessel of Chara;’”’ also one “On the Strata of the Plastic Clay For- mation exhibited in the Cliffs between Christchurch Head, — ss Obituary—Sir Charles Lyell. Hampshire, and Studland Bay, Dorsetshire ;” another ‘“ On the Freshwater Strata of Hordwell Cliff, Beacon Cliff, and Barton Cliff, Hampshire ;” and an elaborate paper on the “ Belgian Tertiaries.’ In 1827 he contributed to the Quarterly a review of Mr. Poulett Scrope’s “ Geology of Central France” (the perusal of which is said first to have stimulated him to prepare and publish “The Principles of Geology” on which his reputation as a philosophical writer mainly rests). These lesser works all showed a power of observation and of general- ization which prepared the learned world for some greater and more important treatise from his pen, which should deal, not with local details, but with the general principles of the science. Nor were they disappointed when his magnum opus, “The Principles of Geology,” appeared in three successive instalments, published respectively in 1850, 1832, and 1833. The work, subsequently enlarged into two volumes, has passed through numerous editions, and is still in as much demand as ever among students of the science. The work was subse- quently divided into two parts, which have been published as distinct books —viz. ‘“‘The Principles of Geology, or the Modern Changes of the Earth and its Inhabitants, as illus- trative of Geology,” and secondly, ‘‘The Elements of Geology, or the Ancient Changes of the Harth and its Inhabitants, as illustrated by its Geological Monuments.” The substance of the last-named work has also been published under the title of ‘‘The Manual of Elementary Geology,” a Frenchstranslation of which was issued under the auspices of the famous Arago. Already, some time previous to the publication of this work, Mr. Lyell had been chosen a Vice-President of the Geological Society ; and in 1828 he had undertaken a journey into the volcanic regions of Central France, visiting Auvergne, Cantal, and Velay, and continuing his journey to Italy and Sicily. He published the results of this expedition in the “ Edinburgh Philosophical Transactions,” and also in the “Annales des Sciences Naturelles.” It was, however, the publication of his “‘ Principles of Geology”’ that gave him that established reputation which he ever since continued to enjoy. “Which of us,” asked Prof. Huxley, in his Anniversary Address to the Geological Society in 1869, ‘“‘ has not thumbed every page of the ‘ Principles of Geology’ ?”” And he adds, “I think that he who writes fairly the history of his own progress in geological thought will not easily be able to separate his debt to Hutton from his obligations to Lyell.’ This cordial testimony of a fellow-labourer in the cause of scientific enlightenment exactly indicates Sir Charles Lyell’s place in the history of that task. He was a man of smgularly open mind, one of those who stand above their contemporaries and hail the dawn of new truths upon the world. His own works mark the progress of his own as well as of the public opinion on the great problems raised by scientific discovery, and he remained to the end of his life always ready for the reception of new facts, and for the corresponding modifications of opinion. Sir Charles Lyell married, in 1832, Mary Elizabeth, eldest daughter of the late Mr. Leonard Horner, but was left a widower in 1873. Sir Charles Lyell had travelled and seen much. Thus in early manhood he 143 144 Obituary—Sir Charles Lyell. explored many parts of Norway, Sweden, Belgium, Switzerland, Germany, and Spain, including the volcanic regions of Catalonia. In 1836 he visited the Danish Islands of Seeland and Monen, to examine their Cretaceous and Tertiary strata. In 1841 he was induced to cross the Atlantic, partly in order to deliver a course of lectures on his favourite science at Boston, and partly in order to make observations on the structure and formation of the Transatlantic Continent. He remained in the United States for a year, travelling over the Northern and Central States, and extending his journey as far southward as Carolina, and northward to Canada and Nova Scotia, his exploration ranging from the basin of the St. Lawrence to the mouths of the Mississippi. On returning from this journey, he published his “ Travels in North America,’ a work of considerable interest to other persons besides geologists, and showing that he could extend his observations to the strati- fication of society around him as well as that of the earth beneath his feet. He paid a second visit to America in 1845, when he closely examined the geological formation of the Southern States and the coasts that border on the Atlantic and the Gulf of Mexico, and more especially the great sunken area of New Madrid, which had been devastated by an earthquake 30 or 40 years previously. Upon reaching England, he published his ‘‘ Second Visit to the United States,” a companion to his former work. For his other scientific papers we must refer our readers to the ‘“ Proceedings” of the Geological Society, 1846-49, and its ‘‘ Transactions.’’ Late in life, about 10 or 12 years ago, Sir Charles Lyell published another very important work on ‘‘The Antiquity of Man,” summarizing and dis- cussing all the important facts accumulated up to that time in favour of the high antiquity of the human race, viewed from the standpoimts of the archeologist, the geologist, and the philologist. Numerous honours were conferred on Lyell m recognition of his services to Science. As far back as 1836 he was elected to the Presidential Chair of the Geological Society, to which he was re-elected in 1850. He received from Her Majesty the honour of knighthood in 1848, and in 1855 the honorary degree of D.C.L. of the University of Oxford was conferred upon him. He had been for many years a Fellow of the Royal Society, and in 1833 re- ceived one of the Royal Society’s Gold Medals for his ‘‘ Principles of Geology.” In 1858 the Royal Society conferred upon him the highest honour at their disposal—the Copley Medal; and in 1864-6 he filled the Presidential Chair of the British Association for the Advancement of Science. He received the Wollaston Gold Medal from the Geological Society of London in 1865 (his continued official connexion with which had precluded his receiving it earlier). He was raised in 1864, on the recommendation of the then Prime Minister, Lord Palmerston, to a Baronetcy, which now becomes extinct by his decease. He was a Deputy-Lieutenant for his native county of Forfarshire. Sir Charles Lyell has been so long and so honourably known among the scientific teachers of the time, that though he had arrived at his seventy- eighth year, and the period of his chief intellectual and physical activity had long passed away, probably even the younger men of the present generation will feel that science is poorer by his loss. At the meeting of the Geological Society of London, held in the Society’s room, Burlington House, Piccadilly, on Wednesday last (February 24th), the President, John Evans, Esq., F.R.S., before commencing the business of the meeting, alluded to the great loss which all present had sustained. He little expected, when speaking on the last occasion, at the Anniversary Meeting, of the services which Sir Charles Lyell had rendered to science for the previous fifty years, that he should have on the present occasion to announce and lament his irreparable loss. Sir Charles Lyell had been a true philosopher and a sincere friend. He had lived to see the extension of science which he had so eagerly desired realized. In future times, wherever the name of Lyell would be known, it would be as that of the greatest, the most philosophical, the most enlightened geologist of Great Britain or Europe. : In accordance with the wish of the Council of the Royal Society, Sir Charles Lyell will rest beside his old friend and fellow-labourer in science, | Sir John Herschel, in Westminster Abbey. al tien . XXX 2. Da g 4 o =" (MIAXXX 2727 q “2DASIZYq UPD S wopgUMveT Uo) “JSPR YJNOS IY/g wolf uI7S SD ‘ROLL Ut WYOQULOLZS fo (W2aLf TTA Id “IT 2A TT wong ee ee eee es ‘SHINAS MAN THE GEOLOGICAL MAGAZINE. NEW SERIES. DECADE II. VOL. II. No. IV.—APRIL, 1875. ORIGINAL ARTICLES. Osa es J.—ConTRIBUTIONS TO THE Stupy or VoOLcANOs.! By J. W. Jupp, F.G.S8. Tue Liparrt IsLtanps.—STROMBOLI. (PLATE VIII.) Presenting as it does the only example of a volcano in the phase of permanent moderate activity to be found in Hurope, Stromboli must always have the strongest claims on the attention of geologists. Here may at all times be witnessed, in perfect security, those explo- sions produced by the disengagement of vapour in the midst of masses of liquefied rock, which, following one another at longer or shorter intervals, and taking place with greater or less violence, constitute a most striking feature in nearly all volcanic eruptions ; and the causes, sequence and attendant phenomena of these outbursts can in the case of this volcano be most conveniently studied. As might be anticipated from the less striking character of its action, Stromboli is less frequently mentioned by ancient writers than Vulcano; yet, as early as the fourth century before Christ, it is spoken of as being in a state of eruption, and references to it occur in the writings of Aristotle, Callias, Diodorus Siculus, Strabo and Cornelius Severus. Most interesting to the geologist, however, is the notice of the mountain by Pliny, who in the first century of our era describes it in terms which are still applicable to it at the present day. But if the ancient accounts of this volcano are somewhat meagre, we are nevertheless fortunate in possessing the means of tracing very completely its history in modern times; during the last one hundred years numerous sagacious and trustworthy observers have visited the volcano, and given clear and accurate accounts of its condition. 'heir descriptions enable us to define the true character of the operations going on within its crater, to determine how far these operations are constant in their action, and to ascertain the limits of variation in the intensity, succession and results of its outbursts. The general characters of the phenomena presented by Stromboli —“the lighthouse of the Mediterranean ’”—are well known to be as follows. The mountain, which is of conical form, rises directly from the deep waters of the Mediterranean to the height of more than 3000 feet above its surface ; as the sea between the Liparis affords 1 Continued from page 115. DECADE II.—YVOL. Il.—NO. Ly. 10 146 J. W. Judd—On Volcanos. soundings of from 300 to 700 fathoms, we must remember that the several islands are only the upper portions of great volcanic cones ; at least one-half of the height of these, and by far the greater part of their bulk being concealed beneath the waves. Stromboli is completely made up of volcanic materials, and presents, not only some obscure traces of a greatly ruined crater at its summit, but numerous indications, in craters and lava-streams, of lateral outbursts on its flanks. But the most striking and interesting feature about the mountain is that on its north-western side there exists a crater in a state of constant activity, which, besides giving off vapours and gases,—either in explosive puffs, in continuous blasts, or in quietly issuing wreaths,—discharges at more or less regular intervals showers of scoriz and volcanic ashes. Occasionally, also, small streams of lava flow from the crater itself or at some lower point on the moun- tain; and that a reservoir of incandescent material exists within the crater, is proved by the fact that, at night, the clouds of vapour and dust above the mountain reflect a fiery glow, either at the moment of the explosion and for a short interval afterwards, or, during times of more intense activity, almost continuously. With regard to the position and relations of the several parts of the mountain, we have numerous measurements of accurate observers to guide us; and the recently published map of the Italian Government enables us to verify their various barome- trical and other determinations. The active crater of Stromboli (Cratére la Fossa) is situated rather more than 600 feet below the summit of the mountain, that is, at a height of considerably more than 2000 feet above the level of the Mediterranean. The diameter of the crater is about 400 feet, and its bottom, which is several hundred feet below the rim on its southern or landward side, ap- pears to be bounded by a crater-wall of but little elevation towards the sea. From this depressed portion of the crater-rim a long slope, called the Sciarra del Fuoco, leads down to the sea, with so steep an incline (85°) that all materials ejected from the crater are unable to rest upon it, but roll down into the sea. The Sciarra of Stromboli constitutes one of the most striking features of the mountain ; its length from the crater to the sea-level is more than 1200 yards, and the breadth of its seaward edge is about 1000 yards. The walls bounding the inclined plane of the Sciarra, and which gradually converge towards the crater, are steep cliffs, seen to be composed of lava-streams, agglomerates, and dykes, presenting their usual relations with one another ; indeed, the whole may be regarded as a miniature representative of the grand Val del Bove of Htna. Its general appearance is well seen in the view (copied from Abich) given as an illustration to Mr. Scrope’s paper in the Volume of this Magazine for 1874, page 532. On the slope of the Sciarra may be observed several well-marked ridges of lava, which are either lava-streams that have flowed down it, or great dykes, formed by lava rising through fissures which have been produced in it during paroxysmal eruptions. We may remark that the Italian word “ Sciarra”’ seems to be derived from the same root as our northern term ‘“Scaur,” and to have nearly the same significance. Having J. W. Judd—On Volcanos. 147 thus briefly noticed the salient features presented by Stromboli, the reader will have less difficulty in following the descriptions of the state of the volcano at different periods as borne witness to by various observers. About the year 1744, according to an account received by Spallan- zani, the volcano threw out such an enormous quantity of scoriz as to cause a “ dry place in the sea,” which remained for some months as a hill rising above the waters, and then gradually disappeared. The probable interpretation of this is that, during a more than usually violent paroxysm of the volcano, a lateral cone was formed on the submerged flanks of the mountain, and, rising above the sea- level, was gradually destroyed by the action of the waves, in the same manner as in the well-known case of Graham’s Isle. In 1768, that able observer of volcanic phenomena, Sir William Hamilton, returning from a visit to Etna, was becalmed for three days among the Lipari Islands. Hamilton, at this time, not only saw the usual explosions of red-hot stones, but noticed that “some small streams of lava issued from its side, and flowed into the sea.” A drawing by Signor Fabris, who accompanied Sir William Hamil- ton on this occasion, shows that, not only was the crater at this time in a state of rather violent activity, but that two lateral outbursts were taking place low down on the south-western flank of the mountain, not far from the hamlet of Ginostra. trop peu familiére pour me permettre de m’en servir, afin de vous exprimer toute ma reconnaissance pour le grand honneur que vous venez de me faire, en me décernant la Médaille 186 Reports and Proceedings— de Wollaston, j’espére que vous voudrez bien me permettre dans la circonstance solennelle dans laquelle je me trouve, de faire usage de Vidiome dont on se sert habituellement dans mon pays. Laissez moi vous dire d’abord, Messieurs, qu’il m’a semblé que ma présence au milieu de vous, était le plus sur moyen de vous donner la “preuve de mes sentiments de gratitude et du prix que j’attache a la distinction dont je vous suis redevable. Cette distinction sera pour moi un nouvel encouragement et un stimulant pour continuer et pour achever, si possible, mes travaux concernant la faune carbonifére de mon pays. L’étude de cette faune, qui doit comprendre plus de 1200 espéces, m’a conduit 4 des résultats trés remarquables. J’espére que je pourrai bientot vous en fournir la preuve et vous démontrer qu’elle se compose de trois grands groupes parfaitement distincts entre eux, quoique possédant un certain nombre d’espéces identiques et dont le premier est presque exclusivement formé des espéces recueillies dans le calcaire de Tournai, le deuxiéme des’ espéces des environs de Dinant, et le troisiéme de celles du calcaire de Visé et de quelques lambeaux de ce méme calcaire des environs de Namur. — Ces faunes sont principalement représentées chez vous, la premiére in Irlande, 4 Hook Point et ses environs, la deuxiéme aux environs de Dublin, et la troisiéme en Ecosse et au centre de Yorkshire, ou elle a été lobject des remarquables recherches de notre savant et regretté confrere le Professeur J. Phillips. C’est par ces travaux, Messieurs, que je compte terminer ma carriére scientifique, si les forces. nécessaires et la santé ne me font pas défaut, et continuer ainsi 4 mériter votre haute et impartiale approbation. The President then presented the Balance of the proceeds of the Wollaston Donation Fund to Mr. L. C. Miall, of Leeds, and addressed him in the following terms :— Mr. Miall,—I have much pleasure in presenting you with the Balance of the proceeds of the Wollaston Fund, which has been awarded you by the Council of this Society to assist you in your researches on Fossil Reptilia. Those who had the good fortune to be present at the meeting of the British Association at Bradford in 1873, and to hear the masterly Report of the Committee on the Labyrinthodonts of the Coal-measures, drawn up by yourself, and those also who have studied the Papers which you have communicated to this Society on the Remains of Labyrinthodonta from the Keuper Sandstone of Warwick, must be well aware of the thorough and careful nature of your researches, carried on, I believe, in a somewhat isolated position, and remote from those aids which are so readily accessible in the metropolis and some of our larger towns. I trust that the proceeds of this fund which I have now placed in your hands will be regarded as a testimony of the interest which this Society takes in your labours, and may also prove of some assistance to you in still further prosecuting them. Mr. Miall, in reply, said that he felt that his sincere thanks were due to the Geological Society for awarding him the Balance of the proceeds of the Wollaston Donation Fund asa token of appreciation of the little work that he had been able to do, and also to the President Geological Society of London. 187 for the terms in which he had been kind enough to speak of him. He should regard this donation, not only as an honour received by him, but also as a trust to be expended to the best of his power in accord- ance with the intentions with which it had been conferred upon him by the Society. The President next handed the Murchison Medal to Mr. David Forbes for transmission to Mr. W. J. Henwood, F.R.S., F.G.S., and spoke as follows :— Mr. David Forbes,—In placing the Murchison Medal and the accompanying cheque in your hands, to be conveyed to our distin- guished Fellow, Mr. William Jory Henwood, I must request you to express to him our great regret that he is unable to attend personally to receive it. His researches on the metalliferous deposits, not only of Cornwall and Devonshire, but of Ireland, Wales, North-western India, North America, Chili, and Brazil, extending as they do to questions of subterranean temperature, electric currents, and the quantities of water present in mines, are recorded in memoirs which form text-books for mining students. They have for the most part been contributed to the Royal Geological Society of Cornwall, which has taken a pride in publishing them; but I trust that it will be a source of satisfaction to Mr. Henwood, after fifty years of laborious research, and amidst the physical suffering caused by a protracted illness, to receive this token of appreciation at the hands of another Society which takes no less interest in the subjects of his investigations. Mr. David Forbes said that in receiving the Murchison Medal, on behalf of Mr. W. J. Henwood, he was commissioned by that gentleman to express his great regret that the bad state of his health and his advanced age prevented his appearing in person to thank the Council for the high honour they had conferred upon him, and the extreme gratification he felt in finding that the results of his labours in the investigation of the phenomena of mineral veins, which had extended over more than fifty years, had thus been recognized by the Geological Society of London. The President then presented to Prof. H. G. Seeley, F.G.S., the Balance of the Murchison Geological Fund, and said :— Mr. Seeley,—Your researches in Geology and on Fossil Osteology have now already extended over a period of upwards of sixteen years, and the numerous and valuable essays which you have contributed to the Annals and Magazine of Natural History, as well as to the Quarterly Journal of this Society, are only a portion of their fruits. Your separate works on the fossil remains of Aves, Ornithosauria, and Reptilia, in the Woodwardian Museum of Cambridge, and on the bones of Pterodactyles, are well known to every student of fossil osteology, and have been thought worthy of the by no means empty compliment of being printed at the expense of the Syndics of the University Press of Cambridge. The esteem in which your researches are held by the Council of this Society, and their hope that you may still be enabled to prosecute them, are best evinced by their presenting you with the Balance of the proceeds of the Murchison Fund, which I now have the pleasure of placing in your hands, 188 Reports and Proceedings. Prof. Seeley replied as follows :— . Mr. President,—I have ever been taught that the Geological Society is the fountain of geological honour. It has always been a great honour to be associated with the Fellows of this Society, who are constructing the sciences we cultivate. Out of this association have grown bonds of comradeship, encouraging some of us to follow on in the labour of those whose work is ended; and when, Sir, I receive at your hands this award of the Balance of the Murchison Fund, I am grateful for such a distinguished mark of sympathy with my special studies, and shall be encouraged by it to prosecute researches which I hope may be better worthy of the Society’s acceptance. The President then proceeded to read his Anniversary Address, in which, after congratulating the Fellows upon their having at length got possession of their new premises, he called attention to the advant- age which acerued both to the Fellows of the Society and to the officers of the School of Mines, Geological Survey, and Museum of Practical Geology, by the close proximity of the two establishments, and ex- pressed a hope that there might be no severance of this union whether by the removal of the School of Mines to South Kensington or other- wise. He also contrasted the position of the Society as regards Funds, number of Fellows, etc., in 1829 and in 1875, the former being the first year in which the Anniversary Meeting of the Society was held in the Society’s rooms at Somerset House. He then took up the main subject of his Address, namely, the question of the antiquity of the human race, and the geological evidence bearing upon it. The Address was prefaced by some obituary notices of Fellows and Foreign Members deceased during the past year, including Prof. Phillips, Dr. F. Stoliczka, the Rev. €. Kingsley, Mr. J. W. Pike, Dr. Arnott, Prof. W. Macdonald, M. Elie de Beaumont, and M. J. J. d’Omalius d’Halloy. The Ballot for the Council and Officers was taken, and the following were duly elected for the ensuing year :—President: John Evans, Esq., F.R.S. Vice-Presidents: Prof. P. Martin Duncan, M.B., F.R.S.; Robert Etheridge, Esq., F.R.S.; Sir Charles Lyell, Bart., D.C.L., F.R.S.; Prof. A. C. Ramsay, LL.D., F.R.S. Secretaries: David Forbes, Esq., F.R.S.; Rev. T. Wiltshire, M.A. Foreign Secretary: Warington W. Smyth, Esq., M.A., F.R.S. Treasurer: J. Gwyn Jeffreys, LL.D., F.R.S. Council: HE. Bauerman, Esq.; Frederic Drew, Esq.; Prof. P. Martin Duncan, F.R.S.; Sir P. de M. G. Eger- ton, Bart., M.P., F.R.S.; R. Etheridge, Esq., F.R.S.; John Evans, Esq., F.R.S., F.S.A.; David Forbes, Esq., F.R.S.; R. A. C. Godwin- Austen, Esq., F.R.S.; Henry Hicks, Esq.; Prof. T. McKenny Hughes, M.A.; J. W. Hulke, Esq., F.R.S.; J. Gwyn Jeffreys, LL.D., F.R.S. ; Sir Charles Lyell, Bart., D.C.L., F.R.S.; C. J. A. Meyer, Esq.; J. Carrick Moore, Esq., M.A., F.R.S.; Prof. A. C. Ramsay, LL.D., F.R.S.; Samuel Sharp, Esq., F.S.A.; Warington W. Smyth, Esq., M.A., F.R.S.; H. C. Sorby, Esq., F.R.S.; Prof. J. Tennant, F.C.S. ; W. Whitaker, Esq., B.A.; Rev. T. Wiltshire, M.A., F.L.S.; Henry Woodward, Esq., F.R.S. ; Correspondence— G. H. Kinahan. 189 CORRESPONDENCE. MR. BIRDS ON THE IRISH GLACIAL DRIFTS. Str,—In a paper in the Gzorocican Macazine for Feburary, ‘On the Post-Pliocene Formations of the Isle of Man,” the author, Mr. J. A. Birds, intimates that an Upper Glacial Drift with underlying “‘ Middle Gravels” has been proved to exist in the east of Ireland. If, however, this observer had read all the evidence on the subject, he would know that if such divisions exist, they have never yet been found! If such drifts exist, they ought to be found in some of the cuttings for the numerous lines of railway that traverse Ireland; but as yet no section showing them has been exposed. In the east of the Island they might be expected to be found, in the cuttings for the railways between Dublin, Belfast and Larne, or Belfast and Neweastle, or Dublin and Wexford; yet they have not been exposed; and if they did exist, they could scarcely have been passed over in the cuttings between Drogheda and Belfast. In the Dublin and Wexford railway, north of Killiney hill, and both N. and 8. of Bray Head, there are indeed Boulder- clays, that a casual observer might suspect to be normal Glacial Drift; but avery slight examination ought to satisfy him that these sus- pected Upper Glacial Drifts were members of the Gravel Drifts ; having been either talus, due to the weathering of a Glacial Drift cliff, or slips from the latter, that had covered sands and gravels, which had accumulated at the base of the cliff. In the east of Ireland the only place where there seems to be drifts at all likely to be Upper Glacial Drift and Middle Gravels, is at the Mourne mountains, on the west coast of Dundrum Bay, and in the Mourne Demesne ; but in both places a very brief examination will show that the upper member of the sections cannot be normal Glacial Drift. The writer of the paper to which I allude has evidently fallen into the mistake made by so many writers of the present day on Drift,—that is, of in- cluding in Glacial Drift all Boulder-clays, if glacialoid, and also the associated gravels and the like; while it is evident that.all stratified Boulder-clays cannot be normal Glacial Drift ; for since the materials were imbedded in ice, they must have been re-arranged by water ; while many unstratified Boulder-clays cannot be normal Glacial Drift, as their present position is due to the slipping or weathering of cliffs. All gravels, sands and the like, cannot possibly be called Glacial Drift, as they have been not only re-arranged, but also sorted, sifted, and transported, since they came out of the ice. If the age of the Glacial Drift is allowed to be proved by such loose evidence as that which is now so commonly in vogue, proofs might be adduced that it isin course of formation, even up to the present mo- ment. In numerous places cliffs of Glacial Drift exist, at the base of which sands, gravels, alluvium, and peat are accumulating, or human works are being constructed. These cliffs in time must form slopes, either by weathering or slipping : and thereby cover up what 1 See Middle Gravels (?), Ireland, Grou. Mac., 1872, Vol. IX. p. 265, and Glacialoid or Re-arranged Glacial Drift, Grou, Mac., March and April, 1874. 190 Correspondence—B. Smith Lyman. - is at their base. This will prove, if the line of argument at present in use be allowed, that all their recent accumulations, and even the railways, are pre-glacial. I have seen from ten to twenty feet of as good Glacial Drift as that from which the existence of the Middle Gravels have been proved (?), covering a recent railway, or some other modern structure ; and I have heard such covering pronounced “good typical Glacial Drift”? by an eminent geologist before he was pointed out what was beneath it. : G. Henry Kryanan, WEXFORD, Feb. 6, 1875. Trish Branch, H.M. Geol. Survey. GEOLOGICAL SURVEY OF YESSO. -Srr,—While thanking you for the kindly notice (in the last re- ceived number of your Macazrinz, October, 1874) of my little report of a year ago on the first season’s field-work of the Geological Survey of Yesso, 1 beg to make a correction in the criticism on the topo- graphical-geological method of Prof. Lesley (chief of the new Penn- sylvania Geological Survey). He should not be blamed for the ‘confusion and unsightliness”’ of the lines on a map that shows the contours of the principal beds of rock as well as of the surface; for his maps are models of clearness and taste, and even on a large scale commonly show for the rocks only the outcrop and the lowest natural drainage level of the beds of chief mining importance, and the topo- graphy is often reinforced by shading, besides the contour-lines. The. addition of contour-lines for such beds above water-level, and to a cer- tain depth below, is my own idea, and what I fondly imagined to be an improvement, especially in mapping limited tracts of land where the owners wish to see at a glance as by a sort of cross-hatching on the map what portion of the ground is underlain by workable beds. In many regions, perhaps most, it is possible to draw such underground contour-lines with a degree of accuracy very useful for practical mining purposes (one coal-bed, for example, was shown by a map to be at 180 feet below the surface of the ground at a point three- quarters of a mile from the nearest exposures of the bed, and on sinking a pit proved to be at 182 feet). The rocks are not in every country tied up in double bow-knots, as they sometimes seem to be in the Himalayas. Of course it is difficult to trace out such contor- tions, or to represent them ona map in any way ; for even every small irregularity in the surface-contours cannot be given on maps of small scale. It must be admitted that to draw two sets of contour-lines on the same map, especially if both are black for photographing, necessarily takes away somewhat from the good appearance of either alone ; but is there not some compensation in the additional information con- veyed, and in the display of the relation of the surface-contours to the underground contours at every point? It must also be acknow- ledged that “observations made at the surface can only be taken for what they are worth,” and the underground contours of a bed of rock must always be somewhat less certain than those of the surface. Still, is it not worth while for the observer to give precisely what, Correspondence—D. Mackintosh. 191 from his study, seems to be the true position of the beds, without, however, exaggerating the certainty of such results? At any rate, no matter how the final map may be drawn, it is hard to conceive of any. way but Lesley’s (more or less perfectly followed) for making out a continuous section of rocks that are exposed only at intervals either on one stream or on different sides of a hill, if the fossils or the resemblance of beds are not (as commonly happens) a complete uide. : You seem rather inclined to regard the hope that my Japanese assistants should become accomplished geologists “‘in a few years” as an “‘ Oriental exaggeration.” But I still see no reason to attach a special geological sense to the expression ; though it is not to be supposed that they could advance far more rapidly than we self- satisfied Anglo-Saxons. Most of them can already make topogra- phical maps with a facility that is unfortunately rare not only among geologists, but even among railroad engineers. In speaking of the report it would perhaps not be amiss to com- mend the Japanese for making public even so small a contribution to geology, not only in their own language, but in one more readily understood by a foreign scholar; the first case of the kind under any native Asiatic government. It is still doubtful whether they will be willing to publish in like manner more voluminous local details with maps and sections. Bens. Smith Lyman. Karraxusui, Supa, YEDO, 9th January, 1875. QUESTIONS CONCERNING THE GEOLOGICAL ACTION OF ICE. ADDRESSED TO THE OFFICERS OF THE ARCTIC EXPEDITION. I nave been led by a long series of observations on the drifts and boulders of the north of England and Wales to conclude that we cannot arrive at a consistent and satisfactory explanation of glacial phenomena until more light has been thrown on many questions, including the following: Is the interior of the Greenland ice-sheet or ice-sheets free from rocky débris, or is it more or less charged with it? Is the base of the Greenland ice capable of pushing forward large stones to great distances? Is it capable of holding stones of considerable size firmly fixed in its grasp, or of polishing and uni- formly striating any stones not fixed in the subjacent ground ? What is the state of the base of icebergs as regards being charged with clay, sand, small stones, or large boulders ? Can a grounding iceberg give a rounded as well as a flat shape to the surface of submarine rocks, or, while endeavouring to regain its normal level, striate a rock-surface down-hill? Can a revolving iceberg scoop out a hollow in the rocky bottom of the sea? To what extent can coast-ice transport earth, stones, and large boulders? Are there any instances, in the Arctic regions, of floating coast-ice radiating from islands so as to distribute rocky débris over an area of 90 degrees? Are there any conditions under which floating coast-ice, ‘charged throughout with detrital matter,” may deposit dome-shaped masses of concentrically-shaped 192 Miscellaneous. lamine, or masses of alternately fine and coarse detritus in an irre- gular and complicated order of succession? To what extent does moving or floating coast-ice smooth and striate rock-surfaces, or give rise to roches moutonnées? To what extent may moving or floating coast-ice, while grounding, be capable of flattening and smoothing the pebbles fixed in its base? Can it produce a series of clearly-cut and parallel grooves on the flattened surface? In the marine Boulder-clay of Cheshire there are many pebbles which have been flattened and uniformly striated on two opposite sides. Are there any conditions under which the mode of action of moving or floating coast-ice may be supposed capable of giving rise to such a pheno- menon? How far, in the Arctic Seas, is the course of surface-currents carrying sea-ice crossed by that of under-currents carrying icebergs ? Do these currents ever flow in diametrically opposite directions ? 2, AspEy Court, CHESTER. D. Macxinrosu, F.G.S. MIiSCHLIOANHOUS.-. ——$————— Tuer Carr oF Naturat History in the University of St. Andrews has been offered to and accepted by Professor Alleyne Nicholson, of the College of Physical Science, Neweastle-on-Tyne. Dr. Nicholson was in no way a candidate, directly or indirectly, for this appoint- ment; but in thus offering it to him unsolicited, the Marquess of Ailsa has the cordial approbation of the University authorities, and may be congratulated in securing for the chair, of which he is patron, so distinguished a naturalist and professor, whose experience extends over two continents.— Scotsman, February 22, 1875. Sus-AERIAL Denupation.—In the Registrar-General’s annual ‘return for 1872, which was printed March 10th, attention is drawn to the excessive rain-fall. The total fall of rain was enormous, and each of the last three months of the year showed an excess. During the quarter rain had fallen at Greenwich on sixty-seven days, a greater number than had been previously experienced as far back as the year 1815. The total fall in the sixty-seven days amounted to 11°32 inches. It has been shown that an inch deep of rain weighs nearly 101 tons per acre, so that upwards of 1,100 tons of water fell in the last three months of the year on each of the 87,000,000 acres of England and Wales !—Dai/y News, 11th March, 1875. Tue Lyett Mepat anp Funp.—Sir Charles Lyell has bequeathed to the Geological Society of London the sum of £2000, together with the die of a medal, to be called “the Lyell Medal.” Not less than one-third of the annual proceeds of the Fund is to be awarded with the Medal. The Balance to be given in any proportions that the Council may see fit. The recipients may be of either sex, and of any country ; and the award may be made for work done, or to assist in present researches, or for memoirs on Geology and the allied sciences. The bequest and the terms in which it is made are alike worthy of so great a name as that of Lyell. THE GEOLOGICAL MAGAZINE. NEW SERIES. DECADE II. VOL. II. No. V.—MAY, 1875. ORIGINAL ARTICIES. Sa T.—Tue Searcu ror Coan uNDER THE “Rep Rocks” oF THE Souta STAFFORDSHIRE COAL-FIELD. By Cuartes Ketiey, Esq. T is now fifteen years since the appearance of the second edition of the late Professor Jukes’s memoir on the Geology of the South Staffordshire Coal-field. The author observed in his preface that a revision of his work had been rendered necessary by the opening of many new mines and cuttings of various kinds which had afforded fresh information on points that had previously been obscure. He mentioned, for instance, certain red clays and sandstones occur- ring at Walsall Wood, and at other places which were at first sup- - posed to belong to the New Red Sandstone, afterwards believed to be Permian, but were ultimately decided to be Coal-measures. Similar terms would now help to show the necessity for a third edition. New sinkings have afforded new information, and certain other red beds believed to be Permian have proved to be Coal- measures. Whoever undertakes the revision and the supplementary work for a new edition will find abundant material, and among the sinkings claiming his attention will be that, recently completed, through the red rocks of West Bromwich, at Sandwell Park, on the estate of the Karl of Dartmouth. In connexion with these red rocks a passing notice may be made of the first search for Coal, thirty-six years ago, by the late Harl of Dartmouth, who, in the face of the prevailing belief that no Coal existed under the red rocks, sunk his famous Heath Pits. These were commenced at the suggestion of his principal agent, Mr. Daw- son, a gentleman who, without being versed in mining affairs, simply applied, in this case, the knowledge he had derived from geological writings, especially those of Sir Roderick Murchison. That cele- brated geologist, from observations made in the old Coal-field, had inferred the existence of Coal under the “ Lower New Red Sandstone,” as the red rocks on the margin of the Coal-field were then named. DECADE II,—vVOL. I1.—NO. Y. 13 194 Charles Ketley—The “ Ked Rocks” near Birmingham. Lord Dartmouth’s experiment, much ridiculed by practical miners, was ultimately successful, and was the beginning of the opening up of a new tract of Coal-measures three-quarters of a mile in width, extending from the “ Hastern Boundary Fault” to the Heath Pits. This addition to the productive area of the Coal-field has since been extensively worked by numerous sinkings, some of which are noticed below. But while the Heath sinking had established the existence of Coal under the Lower New Red Sandstone, and beyond what was formerly considered the eastern barrier of the Coal-field, it seemed to prove also the existence of another “barrier.” ‘There was no “thick” Coal in the shaft of the Heath Pit; thin coals only were found, and it came to be concluded that these occupied the place of the thick Coal, or represented its thinning out. In search of the thick Coal, a “ head- ing” from the shaft was driven eastward, and at the extremity of this a boring was made upwards, striking “red rock,” and another boring was made downwards, reaching a hard rock, which afterwards was believed to be of Silurian age. After these unsuccessful at- tempts, one of the thin coals in the shaft was followed to the west, in the direction of the old Coal-field, and that led into the thick Coal. Sir Roderick Murchison concluded that the shaft proved to be sunk upon a line of dislocation, the prolongation of the upcast of the Silu- rian rocks of Walsall and Tame Bridge. Professor Jukes considered there was a sudden rise of Silurian rocks through the Coal-measures forming a bank, the existence of which had been favourable to the formation of sandstone and the accumulation of clay, but unfavourable to the formation of Coal. From Silurian shale having been found in a coal-pit at Langley Mill, Oldbury, he supposed the bank to be continuous for that distance, about three miles, and he indicated the probable course of it by a dotted line drawn on the map of the Geological Survey. Professor Hull looked upon this Silurian bank as part of the original margin of the Coal-field, and supposed it might be traced southwards to the Lickey district. He held that east of this margin there could be no Coal. There were different opinions as to what lay east of this Silurian bank, but none were favourable to the existence of workable Coal- measures. The sections of the following sinkings, in the tract above referred to, were supposed to show varying thicknesses of red rocks, held to be Permian, overlying varying thicknesses of recognized Coal-measures supposed to have been denuded. Reasoning from these and other appearances, it was concluded that further eastward a still greater thickness of Permian beds rested upon Coal-measures still more denuded :— Permian over Coal-measures Coal-measures. over thick Coal. me wishammeeitsees lace asten Gestiiessaseneto On COLE Ee rmmESeEmO2.Oteed Jigar (Clobigay Gog oe" 0g po) con BE gg tt ton, SW) 5 Heath Pits Pies liiaidle'| Suse cides cede See eC OO lye tamer rRNA OL 53 Bullock’s Farm Pits... COO ao ces aD Unitt’s Boring at the “ Ruck of Stones” 664 97 cd0. 000 Abandoned. Charles Ketley—The “ Red Rocks” near Birmingham, 199 The position of the boring at the “Ruck of Stones” was more than a mile east of Bullock’s.Farm Pit, and the general rise of the strata to the west being at an angle of about 10 degrees, it followed that a good part, if not the whole of the 700 feet of Permian at Bullock’s Farm, must be below the 660 feet passed through at the “Ruck of Stones,” from which Jukes concluded “there must be in the neighbourhood of West Bromwich a total thickness of 1500 feet at the very least, composed of rocks of the Permian formation.” (South Staffordshire Coal-field, page 12.) After pointing out that in the southern part of the Coal-field we have nearly or quite a thousand feet of Coal-measures over the thick Coal, without including any Permian, Jukes remarks upon the lesser thicknesses of Coal-measures shown in the above sections : ‘“‘We have in these facts a clear case of unconformability between the Permian beds and the Coal-measures. We see that after the Coal-measures had been deposited they had suffered largely and very irregularly from denudation, several thousand feet of strata having been removed from one place, which were left untouched at another, before the Permian beds had begun to be deposited upon them.” . . . “It is perhaps rash to generalize from the very scanty data we possess as to the precise relations between the Permian and Coal-measures. On so important a point, however, it is, I believe, a duty to state every opinion that may be fairly arrived at. I will therefore state, as my belief, that not only near West Bromwich, but generally in South Staffordshire and the adjoining counties, the Coal-measures suffered very generally from denudation before the deposition of the Permian, and that the Red Sandstones of that formation were largely deposited in hollows and excavations worn in the Coal-measures by this denudation; and, moreover, that this excavation and denudation had in places proceeded to the length of being continued right through the Coal-measures down to the rocks below.” (South Staffordshire Coal-field, page 136.) And he says further, “It is probable that a little further east of the Heath Pits, the Coal-measures are entirely wanting, and the ‘red rocks’ of the Permian formation rest directly on the shale or ‘bavin’ of the Silurian formation. This, then, would be one of those cases where the denudation of the Coal- measures had proceeded the length of totally removing that entire series of rocks previously to the deposition of the Permian beds.” (South Staffordshire Coal-field, p. 139.) The conclusions then of some of the highest geological authorities were that a Silurian bank, running north and south from West Bromwich, cut off the Coal, and that east of that bank a great thickness of Permian rocks would be found to overlie denuded Coal- measures, or else to rest upon older rocks. This view of the case is well shown in the following horizontal section taken from the Geo- logical Survey, Sheet 25, No. 7 H. and W., “through Kingswinford, Dudley, and West Bromwich.” (See page 196.) Or, supposing there had been no denudation, and the rocks to lie in their natural thicknesses, then any one sinking for Coal was warned that he must calculate upon the possibility of having to go through 1500 feet of Permian and 1000 feet of Upper Coal-measures, before 196 Charles Ketley—The “ Red Rocks” near Birmingham. reaching the place of the thick Coal. So long a time having elapsed after the publication of these opinions without further trial being made to find Coal under the red rocks proves how generally the warning had been taken. At last the Sandwell Park Colliery Company, under the euidance of Mr. Henry Johnson, ventured to try this doubtful ground; and their enterprise has been rewarded by the finding of the thick Coal, as well as other Coals and Ironstones common to the old Coal-field. Besides yielding to the explorers the object of their search, the Sandwell sinking has afforded evidence en- abling us to perceive that the red rocks of Bullock’s Farm and the other West Bromwich sinkings hitherto classed as Permian are in fact Coal-measures. In the Sandwell shaft, at the depth of 110 yards, in red measures, were found nume- rous fossil plants, that on being submitted to proper authorities for examination were pronounced to be Per- mian. At 200 yards a seam of Coal seven inches in thick- ness was found; overlying the Coal was a black shale full of fossil plants, and under- neath the Coal was a bed of fire-clay containing Stigma- ria. Several of the plants in the roof-shale at 200 yards proved to be specifically identical with others among those found in the red beds above mentioned, showing that at the depth of 110 East. SANDWELL PARK. West BromwicH Lord Dattmouth’s Heath Pits West. Canal Birmingham and Garden of f= lets) i] oo z 2m ARATE D 0 Wolverhampton Rd. a p=) it fo) o fe! a = is} aq G4 6) oO =| ° 8 un oO & = | oO imal E a a 3 g A ¢ so} (5) is] Gt 4 12) fo} 2 Sg oO = = a a * 6) 1. Upper Sulphur Coal.—2. Two-foot Coal—8. Broach and Herring Coal.—4. Thick Coal. 1 Mile. 0 Scale, 2 inches to 1 Mile. Charles Ketley —The “ Red Rocks” near Birmingham. 197 yards, if not earlier, the sinkers entered the Coal-measures. A second seam of Coal six inches thick was met with at 230 yards, and a third seam of the same thickness at the depth of 244 yards. From this third Coal to the thick Coal the depth was 174 yards. As to the 110 yards overlying the first observed fossils, it seems that, if any Permian beds form a part of that thickness, they are wanting in those charaeters by which we have been accustomed to distinguish the Lower Permian rocks from the Coal-measures. Sandwell Pit, being one mile east of Bullock’s Farm Pits, and all the beds rising to the west, it follows that the red beds of Bul- lock’s Farm and the other West Bromwich sinkings, rise from beneath the Upper Coal-measures of Sandwell. So that there is not, as there was supposed to be, a great thickness of Permian beds deposited upon denuded Coal-measures, or occupying the place of Coal-measures entirely swept away, or resting upon older rocks. On the contrary, we have Coal-measures throughout the greater part of the sinkings. Thus, with respect to the red rocks of West Bromwich, the Sand- well sinking teaches that the position in the geological scale of, at least, the greater part of them had been misunderstood for want of better evidence, and that they are not Permian, but Coal-measures. It must be evident there is more in this fact than a mere change in classification, and that it is of great interest and importance as bearing upon the question regarding the depth of the Carboniferous rocks, “‘not only near West Bromwich, but,” perhaps, ‘“ generally in South Staffordshire and the adjoining counties.” The opinion of Professor Jukes as to the thickness of the Permians and of the Coal-measures, quoted above, was based principally upon the evidence afforded by Bullock’s Farm and the other West Brom- wich sinkings. In his chapter on the Permian rocks of the South Staffordshire Coal-field, he says :—‘“‘ There are two parts of the dis- trict, from the examination of which it is possible to arrive at a tolerably complete notion of the structure and sequence of the Per- mian rocks, namely, the country about the Lickey and the Clent Hills, and the neighbourhood of West Bromwich.” (South Stafford- shire Coal-field, page 9.) In estimating the depth at which profit- able Coal-measures’ might lie, the thickness of red rocks, which was known approximately, was added to an almost equal thickness for Upper Coal-measures supposed to underlie the red rocks; but now that the red rocks themselves prove to be Upper Coal-measures, we see that the thickness of the Upper Coal-measures has been reckoned twice over. Had Jukes possessed such evidence as Sandwell now gives, not only would he have seen the probability of Coal under- lying extensive untried tracts, but his estimate of the depth at which the Coal might be won would have been reduced by leaving out a great part of the 1500 feet reckoned for the thickness of the Permian. The Sandwell section exhibits a greater thickness of Coal-measures over the thick Coal than had been opened up previously. Its highest beds appear to be new. The three little Coals were not before known as a series, but it is probable the 9-inch Coal met with in Bullock’s Farm Shaft at 70 yards from the surface is one of the same 198 J. Starkie Gardner—On the Gault Aporrhaide. series. Probably, in other sections in various parts of the Coal-field, some of these higher Coal-measures may be traced, suggesting that a much greater thickness of Upper Coal-measures than we at present know of spread over the whole extent of the Coal-field previous to its elevation and denudation. Stimulated by the Sandwell success, other companies are forming to search for Coal under the red rocks of large estates situate still further away from the “eastern boundary” of the old Coal-field than Sandwell. Is it not probable that still higher Coal-measures may be recognized? Is it not possible that the Spirorbis Limestone may yet be found over all, to prove the relation between the South Staffordshire and the Warwickshire Coal-fields on the one hand, and the Wyre Forest Coal-field on the other ? I].—On THE GAULT APoRRHAIDZ. By J. Starniz Garpner, F.G.S. (PLATE YI). (Continued from page 1380.) GROUP 4. —Spire moderately long, generally without carine, always ribbed transversely. Wing expanded and quadrate, pro- longed posteriorly into a sharp point. Type :—A.-Parkinsoni. AporRrHais MARGINATA, Sowerby. PI. VI. Figs. 1, 2, 3. Synonym: A. Orbignyana, Pictet, and Roux. Description.—Shell elongated, the spire forming an angle of 33° and measuring ‘046: composed of eight convex angulated whorls, which are closely covered with spiral striz, each alternate one being nearly twice as prominent as the intervening one. The whorls are ornamented by short elongated ribs, which are nodose and tuber- cular on the lower, but thin and linear on the upper whorls, and more numerous and very fine towards the apex. These ribs have an occasional tendency to form varices. On the body- whorl there are two more or less distinct rows of tubercular nodes ; the uppermost row, being the more important, is continued in the form of a tuberculated ridge on the wing process. The wing is large, broad and quadrate, and thickened in the same manner as in the recent A. pes-pelicani, which our shell much resembles. It is sinuous at its margin, and terminates anteriorly in a blunt process; posteriorly ending in a long and rather recurved sabre-shaped spike, deeply erooved ventrally. Between this and the margin of the remainder of the wing is a sinus. The mouth is narrow, and shaped, as in A. pes-pelicani, like a lance-head point downwards. The anterior canal is moderately long, :021, delicate and straight. The inner lip and underside of the pterygoid process are enamelled ; length of the wing to the end of spike is ‘082. Fig. 3 represents a variety from an upper bed in which the ribs continue thin and linear to the last whorl, instead of being nodose or tubercular. Distribution —Found most abundantly at Folkestone, where it ° Vol. IL., PILVI. Decade IT. New SERIES. Geol. Mag. 1875. CONN WI ti i‘ : Wy Ait REN MN \\ KK Anny FOSSIL APORRHAID#. J. Starkie Gardner—On the Gault Aporrhaide. 199 occurs in all the beds of the Gault; also at Lyme Regis and Cambridge; on the Continent it is found in the Paris and Mediterranean basins, Switzerland, and at most places where the Gault occurs. Specimens with exaggerated varices are met with at St. Florentin. History.—It was named R. marginata by Sowerby in 1836, who figured a fragment of the spire in the Geol. Trans. vol. iv. pl. 11, fig. 18, pp. 114 and 365, from the Gault of Kent. His description is, however, not clear, and applies equally to A. carinata. The figure is drawn from a specimen which has the shell partly preserved in the spire, but only the cast of the body-whorl remains; in conse- quence of this, and of the want of clearness in the engraving, the second anterior keel scarcely shows. As a result, and from no mention being made in the description of the two keels, all Continental and most English writers, supposing Sowerby’s form to have but one keel, re-named the species A. Orbignyana, which - really is invariably bicarinated. In the same year, 1836, Michelin, in the Mém. Soc. Géol. t. iii. p. 100, quoted Sowerby’s description, but named the shell R. costata. In 1838 D’Archiac included Rh. marginata in his lists from Novion and St.-Pot; and in 1842 Leymerie notices it from Ervy. Again, in 1842, D’Orbigny figured it as R. Parkinsoni (not of Mantell) in the Terr. Cret., adding a variety of localities to those previously known. In 1850 he entered it in the Prodrome, both as R. costata and as Ff. submarginata. In 1849 we find this shell named R. carinella (not D’Orb.) by Pictet and Roux, who figured it from the Gault of Saxonnet, etc.; but in 1853 they re-named it R. Orbignyana, a name by which it has since been generally known. It has been cited under various names, generally as R. costata, by many authors. In 1857 by D’Archaic from the Pas-de-Calais; in 1853 by Studer from Ste.-Croix; in 1854 by Renevier from the Perte-du-Rhone; in 1854 by Cotteau, and in 1857 by Raulin and Leymerie, from the Yonne; and in 1857 by Ebray from Cosne. In Morris’s Catalogue, 1854, it is called mar- ginata. From 1859 it has been known exclusively to European authors under its specific name of Orbignyana; see Desor and Gressly, Pictet and Campiche, Gabb, Jaccard, ete. In 1864 Pictet and Campiche described a variety as A. obtusa, but it is possible that their specimens may have been casts of A. marginata ; whilst perhaps some of the more elongated casts, they thought to be of Orbignyana, are A. carinata, a species otherwise absent in Switzerland. In 1865 Mr. R. Tate described this and marginata as separate species, failing to see that they were identical." Pictet and Campiche adopted Sowerby’s name marginata, and ap- plied it to a species with a single keel on the body-whorl, a form which their fig. 2, pl. xciv., shows to be identical with A. maxima of Price. Their statement, that they “possess specimens from Folke- stone which prove the identity of this type with ours,” is difficult to reconcile with their figures and descriptions ; it is, however, abso- lutely certain that Sowerby’s marginata is identical with Orbignyana of Pictet and Roux. 1 Geol. and Nat, Hist. Repertory, 1865. 200 J. Starkie_Gardner—On the Gault Aporrhaide. The form of the shell recalls 4. Parkinsoni, Mant., with which T have grouped it, but the tuberculated nodes, thickness, and differ- ence in form of wing, and the nodosely keeled appearance of the last whorl, are characters which should have rendered confusion im- possible. The following are closely allied species, and are from the Gault :— A. Drunensis, D’Orb.; A. fusiformis, P. and R.; A. pseudosubulata, d’Orb.; A. obtusa, P. and C.; A. Varusensis, d’Orb. Aporruais Parxinsont, Mantell. Pl. VI. Figs. 4, 5, 6, 7. Description.—Shell elongated ; the spire forming an angle of about 30°, is composed of 9 or 10 convex whorls, which are finely striated spi- rally, the strize being sometimes wider apart in front of the suture. Hach whorl is rather irregularly ornamented by 16 to 20 or more, slightly flexuous, slender ribs, which have, though rarely, a tendency to pro- duce varices. The body-whorl is wholly destitute of carinze, and is _ prolonged in a broad rounded expansion obliquely truncated at the extremity and sinuous at its anterior margin, where it unites with the canal; there is at the posterior margin a deep sinus equal to half the length of the wing, and above this sinus is a long recurved canaliculated point, in some species nearly equal to the length of the spire and accompanying it, but at a considerable angle. On the wings the continuation of the striz is interrupted and disconnected by rather strongly marked lines of growth crossing them, giving it a somewhat reticulated appearance. The wing is much thinner than in A. marginata. The aperture is narrow, and the anterior canal moderately long. The Blackdown specimens are usually of rather smaller size, the ribs slightly more prominent, and with a greater tendency to produce varices. The sinus in the wing isnot so deep, and the anterior canal is shorter. 4 This species is easily distinguished from all others of the Gault by the rounded appearance of the last whorl, its elongated ribs, and by the form of the wing. The superior prominence of the striz in front of the sutures is not an important character, although considered to be such by Pictet. A number of similar forms are described by Continental authors, none of which appear to be identical with this or the next species. This form of shell seems more especially to characterize the Chalk, representatives being found in all parts of Europe. It is very like A. occidentalis of recent times. Distribution.—It is found abundantly at Folkestone, Cambridge, and Blackdown; also at Sidmouth, and in the ferruginous nodules of Shanklin and other Lower Greensand (Neocomian) localities. Fitton and Mantell give it an extended range in the Chalk, but this range belongs more probably to the next species. On the Continent it is common to the Gault of the Paris and Mediterranean Basins, and to Switzerland. Specimens from St. Florentin have extravagant sutures, and approach A. Mantelli by the prominence of their ribbing. History.—TVhis species was first figured by Parkinson in his Organic Remains, 1811, vol. iii. p. 63, pl. 5, f. 11, from a Blackdown specimen. In 1822 Mantell, in the Geology of Sussex, p. 72, de- J. Starkie Gardner—On the Gault Aporrhaide, 201 scribed a Blackdown specimen, and also, p. 108, one from the Grey Chalk. He says: ‘‘ This species occurs in the Greensand of Devon- shire, and is figured in the third volume of Organic Remains. As it has not received a specific appellation, I have named it from my excellent friend James Parkinson, Esq., M.G.S.” It is therefore evident that, although he confounded the Greensand with the Chalk species, the Blackdown specimen figured by Parkinson he intended to bear the name Parkinsoni. The figures in pl. xviii. are unfortu- nately of not much value. This error of Mantell has led to much misunderstanding and confusion. In 1827 Sowerby, in the Mineral Conchology, pl. 558, figs. 5 and 6, re-figured Parkinson’s original examples from Blackdown, but unfor- tunately included under the same name a quite distinct London-clay species, now known as A. Sowerbii. He again figured the Black- down fossil for Fitton in the Geol. Trans. 2nd series, vol. iv. pl. xxviii. In 1839 Geinitz, in his work on the Saxon and Bohemian Cretaceous Series, figures some imperfect and doubtful specimens as R. Parkinsoni, but considers that Mantell had figured a different species from Sowerby. The figure that most resembles Parkinsoni, and which he calls Parkinsoni of Sowerby, he re-named Reussii, distinguishing it as having ‘“‘ wider and shorter whorls, with the ribs multiplied on the last whorl, and continued to the outer edge of the wing.” Geinitz, however, subsequently, in 1850, declared that Par- kinsont is not found in Germany, all the various forms there being distinct. Goldfuss figures a very similar form as R. papilionacea, Reuss, two others as R. Reussii and R. megaloptera (Verst. der Bohm. Kriede, tab. ix). The following notices probably all refer to true Parkinsoni. Brongniart, 1829; Leymerie, 1842, Gault, not Lower Chalk; D’Archiac and Lesueur, 1846, figuring at the same time what appears to be a young specimen of this shell as Littorina plicatilis, Mém. Soc. Geol., vol. v. pl. 17. f. 8; Graves, Gault of Oise, 1874; D’Archiac, Gault of Escracnolles, Cornuel, Haute-Marne, 1851; Gras, from Isére, 1852; Renevier, Perte-du-Rhéne, 1854; Cotteau, from the Yonne, © 1854; Ebray, Lower Gault of Cosne, 1857; Raulin and Leymerie, Yonne, 1858; and Semann from the Glauconie de la Sarthe. In addition to these, this shell is figured by Pictet and Roux in the Moll. Foss. des Grés Verts, pl. 24, f. 25; and by Briart and Cornet, Meule.de-Bracquegnies p. 18, pl. ii. f. 4,5, 6; fig. 4 has a wing differing from ours, but it has probably been restored; Dr. Chenu in the Man. Conch. p. 560, 1859. D’Orbigny figured A. marginata in the Terr. Crét. as 4. Parkinsoni, and mentions it in the Prodrome, in which he separates the Blackdown species under the name of f. MMegera. In England, Professor Edw. Forbes was, I think, the first to separate the Chalk species of Mantell from that of the Gault, in the Quart. Journ. G. §. for 1845, p. 850; Prof. Morris gives it in his Catalogue of British Fossils from Folkestone and Blackdown; and Mr. Tate described it under a sub-generic name as Perissoptera Reussii in 202 J. Starkie Gardner— On the Gault Aporrhaide. the Geol. and Nat. Hist. Repert. p. 99, £18. 4. Robinaldina and A. glabra, from the Lower Greensand, have both been confounded with this species. For the remaining references to A. Parkinsoni, see A. Mantelli. Aporruais Manrenu, mihi. Pl. VI. Figs. 8, 9. Synonym: A. Parkinsoni, Mant. Description.—Shell elongated, spire composed of convex whorls, ornamented with 12 or more regular, rather oblique, transverse ribs, extending the whole breadth of the whorls. Last whorl destitute of keel. The wing is broad, angular, and quadrate, prolonged poste- riorly into a point, beneath which is a deep sinus, succeeded by a broad, quadrate expansion, which expansion is also frequently pro- longed into a point, parallel to the first, truncated at its outer margin. The mouth is narrow, porcellanous; the anterior canal moderately long and straight. A. Mantelli differs from the Gault form A. Parkinsoni in the fewer number of ribs and their much greater relative prominence. The broad, quadrate expansion is much more truncated, angular, and pointed, both anteriorly and posteriorly. Distribution.—It is found in the Grey Chalk of Dover, and, on the authority of Mantell and others, at Hamsey, Leacon Hill, South Downs, etc.; but the only perfect specimens I have seen have come from a bed of the Grey Chalk known as the cast-bed, between Dover and Folkestone. The condition in which the fossils of this bed are found is peculiar; for although casts, they are not internal moulds of the shells, but the test seems very gradually to have perished without obliterating the external markings, which remain distinct in the form of a thin deposit of sulphate (?) of iron on the mould. Many of the fossils obtained from this deposit are peculiar. History.—It will be seen, on referring to the history of A. Parkin- soni, that Mantell first named the Blackdown species Rostellaria Par- kinsoni, but that he also included the present Grey Chalk species, which bears a strong resemblance to it, under the.same specific name. ‘This shell, however, differs in several specific characters, and requires separating from the Gault form, and does not appear identical with any of the Chalk forms described by Continental authors. Ihave therefore named it after Mantell, who first described it. Among British authors, Dixon, in his Geology of Sussex, p. 358, tab. xxvii. f. 31, 36, describes this shell as A. stenoptera, and Mr. Tate, in 1865, as A. Parkinsoni. AporrHais ManTELLI, var. SUB-TUBERCULATA, mihi. Pl. VI. Fig 10. A form exactly resembling A. Manielli in the shape of the wing and spire, excepting in the last whorl, on which the ribs are divided into two distinct rows of tubercles. The ribs on the re- mainder of the shell are finer, and do not quite reach to the sutures. It is a smaller shell than those from the Grey Chalk of Dover. Com- pare Fig. 10 and Figs. 8, 9. Two specimens are in that part of Mr. Cunnington’s collection recently purchased by the British Museum. They were found in the Chalk Marl, near Devizes. Ralph Tate—New Liassic Fossils. 208 In the present imperfect state of my knowledge of the numerous similar European forms, I have thought it only advisable to give a list of the species known and described, and _to state that the pterygoid processes or wings of those mentioned below are more expanded, and are attached toa greater portion of the spire, than those just described, and are none identical with the English forms. List of species from the Chalk figured by continental authors allied to A. Mantelli :— R. acutirostris, Pusch, 1837; Geinitz, 1839. R. gigantea, Geinitz, 1839. LR. megaloptera, Reuss. R. papilionacea, Goldfuss, Geinitz, Reuss, ete. R. emarginulata, Geinitz, 1850. A. stenoptera, Goldfuss, 1843. A. Reussi, Geinitz, 1842. Buceinum turritum, Roemer, 1841. Several species from Gosau may be included in this group. R. costata and granulata, Sow.; R. digitata and crebricosta, Leheli; R. Partschi, Leh.; R. passer, and-several undescribed species in the Museums at Dresden, Vienna, Munich, etc. A. glabra, and —__ L—Nore on THE TRANSITION FROM CARBONIFEROUS TO PERMIAN. Communicated by Count A. G. von Marscuatt, F.C.G.S., ete. N Spitzbergen the late German Expedition obtained the following fossils from Horn Sound, on the south-west coast :— 1. Spiriferina Hoeferiana, sp. n. 2. Spirifer Wilezeki, Toula. 3. striatus, Martin P 4 lineatus, Martin, sp. 5. ” , var. elliptica, Sow. ? 6. Camearophoria crumena, Martin, sp. 7 8 9 2? 9? . Productus Weyprechti, Toula. 3 3 sp. (comp. P. Prattenianus, Norwood). Pe undatus, Defr. ? 10. 99 Wilczekt, sp. n. 11. 5 longispinus, Sow. 112" 39 Spitabergianus, sp. 0. 13. (Strophalosia) Canerint, M. Vern. and K. 14. Strophalosia Leplayi, Gen. 15. Chonetes Verneuiliana, Norw. and Pratten; var. nov. 16. oy granulifera, Sow. ‘ 90 sp. ind. 18. Pecten (Aviculopecten) Wilczekt, sp. n. With the exception of one species, the individuals are all of small size. Some are genuine Carboniferous species, and some genuine Permain; and they appear to be transitional from the Carboniferous limestones to the Zechstein; all occurring in a well-determined group of strata; but some, characteristic elsewhere of one or other of the above-mentioned formations, being found occasionally in the same hand-specimen, as Productus longspinus and Strophalosia Canerint. This circumstance may be regarded as corroborative of the gradual passage from the Carboniferous to the Permian, as held by Prof. Geinitz for Nebraska, and by Dr. G. Stache for the southern Alps. IJl.—Tue Groiocy or THE BurnuEy CoAL-FIELD. HIS work, which is one of the recently published Memoirs of the Geological Survey of England and Wales, includes a description of the country around Clitheroe, Blackburn, Preston, Chorley, Haslingden, and Todmorden, and explains Quarter-sheets 88 N.W., 89 N.E., and 92 §.W. of the One-inch Geological Map. It is by 1 From the Proceed. Imp. Acad. Sci. Vienna, June, 1874, vol. lxx. p. 133. Reports and Proceedings. 273 Eroioancs Hull and Messrs. Dakyns, Tiddeman, Ward, Gunn, and De ance. The work contains a description of the physical features of the district, a detailed account of the Carboniferous rocks along the Ribble Valley, special accounts of the Burnley and Chorley Coal- fields, with notices of the Permian and Triassic rocks, of the Glacial and Post-Glacial Drifts, Igneous rocks, minerals, etc. There is also an extensive catalogue of the fossils from the Carboniferous rocks, prepared by Mr. Etheridge, and a list of works and papers relating to the geology of Lancashire and some parts of the adjacent country, by Messrs. Whitaker and Tiddeman. REPORTS AND PROCHEDINGS. Gronocicat Socrery or Lonpon.—I.—April 14th, 1875.—John Evans, Esq., F.R.S., V.P.R.S., President, in the Chair.—The follow- ing communications were read :— 1. “Descriptions of New Corals from the Carboniferous Lime- stone of Scotland.” By James Thomson, Esq., F.G.S. In this paper the author described some forms of corals from the Carboniferous Limestone of Scotland, which he regards as new species, and as belonging to three new genera allied to Clisiophyllum. In the group which he names Rhodophyllum the calice is circular and shallow; the epitheca thin and smooth; the septa thin and numer- ous; and the columellar boss dome-shaped, slightly raised above the inner margin of the primary septa, and clapsed by subconvolute ridges. The species referred to this genus are Rhodophyllum Craig- ianum, FR. Slimonianum, R. Phillipsianum, R. Argylianum, R. retieu- latum, and R, ellipticum. Aspidiophyllum has the calice generally circular, shallow ; the septa forming thin lamin for about half their length from within, when they become flexuous, and the columellar boss promient and helmet-shaped. The species are named A. Koninckianum, A. Hualeyanum, A. cruciforme, A. elegans, A. Hennedii, A. Danai, A. dendrophyllum,. A. ellipticum, A. Paget, A. scoticum, and A. lacum. The third genus, Kurnatiophyllum, is most nearly allied . to Rhodophyliwm, but has the columellar space slightly raised above the inner margin of the primary septa, and crowned by bending or wavy lamellee, some of which pass over the central space in sinuous folds. The species are described under the names of R. concentricum, clavatum, Tyleranum, intermedium, ellipticum, Ramsayanum, Youngianum, Harknessianum, lamellifolium, bipartitum, octolamellosum, Haimianum, Edwardsianum, and Davidsonianum. In aspecimen of Aspidiophylium Hualeyanum the author noticed in the open interseptal space a small tube, 4 lines long, around the inner margin of which there was a group of oval bodies, which, from their close proximity to the inner margin of the primary septa and their form, he is inclined to think may be ova. 2. “On the Probable Existence of a Considerable Fault in the Lias near Rugby, and of a New Outlier of the Oolite.” By J. M. Wilson, Esq., M.A., F.G.S. DECADE II.—YOL. Il.—NO. VI. 18 274. Reports and Proceedings— The author called attention to what appeared to him to be a great fault in the Lower Lias at the village of Low Morton, near Rugby, where a sandpit is worked against the face of a steep hill to a depth of nearly 50 feet. The sand in the valley, as proved by wells and borings, is of great depth. Above the sandpit is a claypit, and the author stated that the clay is bounded towards the sand by a highly inclined face of clay, against which the sand is thrown. This face of clay can be clearly traced for a distance of more than half a mile, running inaS.H. and N.W. direction. If continued to the §.E., it would pass close by Kilsby Tunnel, the difficulties met with in the construction of which may have been due in part to a continuation of the fault; whilst if continued to the N.W., it would coincide generally with the valley of the Clifton Brook, the bed of which is also occupied by a great depth of sand. The line of fault thus passes between Rugby and Brownsover, and the author suggests that it is the cause of the presence on the summit of the Brownsover plateau of an extensive oolitic mass of Stonesfield-slate character. The line of fault continued further would connect with the Atherstone and Nuneaton fault, and agree with this in having its downthrow on the N.E. side. 3. “On a Labyrinthodont from the Coal-measures.” By J. M. Wilson, Esq., M.A., F.G.S. The fossil referred to in this paper was from the Leinster Coal- measures, and was regarded as probably belonging to the genus Keraterpeton of Prof. Huxley, although the outer posterior angles of the skull do not appear to have been prolonged into cornua. 4. “On Cruziana semiplicata.” By J. L. Tupper, Esq. Com- municated by J. M. Wilson, Esq., M.A., F.G.S. In this paper the author gave a detailed description of a slab of unknown origin, but said to have been obtained from a workman at Bangor, containing several specimens of the fossil described by Salter under the name of Cruziana semiplicata. The author discussed the characters presented by the fossil, the mode of crossing of those specimens which crossed each other in the slab, and especially the structure shown where a transverse section of the fossil was to be seen, in which, when perfect, it was clearly of an elongate elliptical form, with a cortical or external layer inclosing a medullary portion of lighter colour. From his examination of the specimen the author seemed inclined to ascribe to Cruziana an animal origin, and to re- gard it rather as fossilized animal structure than asa cast of the track left by the feet of some animal passing over the surface of the sand. The following letter was read from A. Irving, Esq., F.G.S., dated High School, Nottingham, April 8th, 1875 :— “There is at the present time a very interesting section of Rheetic beds and Boulder-clay exposed in the cutting of a new railway which is in process of construction from Melton Mowbray to Nottingham. The distance of it from the latter place is between five and six miles. In some places extensive erosion has taken place of the Paper Shales of the Rheetic series; in others they are much contorted; in others, again, the material of these shales appears to have been broken up, Geological Society of London. 275 almost pulverized, and redeposited among the drifted materials. The boulders vary in size from that of a man’s fist to two or three times that of a man’s head, and are nearly all composed of rounded and subangular masses of Lias limestone; many of them are distinctly striated with the ice-markings so familiar to geologists. Large and small quartzose pebbles are extremely common, derived, in all prob- ability, from the denudation of the Bunter, further north by a very few miles. There isalso much rotten Marlstone from the Middle Lias, and a great quantity of re-deposited red Keuper marl. A few large boulders of Carboniferous limestone are contained in the medley mass; and a fragment of Coal-measure Sandstone has also been found containing the most distinct impression of a specimen of Stigmaria, with rootlets attached: this is now in the possession of Mr. Parry, the engineer of the line. For some portion of the slope of the hill the Boulder-clay forms the surface of the ground, and it caps the whole of the hill which lies between Plumtre and Stanton- on-the- Wolds, though it is here covered by several feet of drift-marl, free from pebbles and boulders, and evidently derived from the Keuper formation, whose outcrop occupies a large area of the ground in the neighbourhood. At the shaft the Boulder-clay is 70 feet thick. In some places the Paper Shales have been eroded quite through, so that the Boulder-clay rests immediately upon the lower grey marls of the Rhetic, which are very regular, and have the same thickness (10 to 15 feet) here which they have in other sections in this country. “JT have thought it right to send the Society this brief communi- cation, though several months must elapse before the railway will be lowered to its proper level. When this is done, we shall get a section, I hope, second only to that at Westbury-on-Severn.” II.—April 28, 1875—John Evans, Esq., V.P.R.S., President, in the Chair.—The following communications were read :— 1. “On Stagonolepis Robertsoni, and on the Evolution of the Crocodilia.” By Prof. T. H. Huxley, Sec. R.S., F.G.S. After referring to his paper read before the Society in 1858, the author stated that he had since obtained, through the Rev. Dr. Gordon of Birnie, and Mr. Grant of Lossiemouth, further materials, which served at once to confirm the opinion then expressed by him, and to complete our knowledge of Stagonolepis. The remains hitherto procured consist of the dermal scutes, vertebra of the cervical, thoracic, lumbar, sacral and caudal regions, ribs, part of the skull and the teeth, the scapula, coracoid and intercavicle, the humerus, and probably the radius, the ilium, ischium and pubis, the femur, and probably the tibia, and two metacarpal or metatarsal bones. The remains procured confirm the determinations given by the author in his former paper, except that the mandible with long curved teeth therein supposititiously referred to Stagonolepis proves not to belong to that animal. From the extant evidence it appears that in outward form Stago- nolepis resembled one of the existing Caimans of intertropical America, except that it possessed a long narrow skull, like that of a Gavial. The dermal scutes formed a dorsal and ventral armour, 276 Reports and Proceedings— but the dorsal shield did not contain more than two, nor the ventral shield more than eight longitudinal series of scutes. The posterior nares were situated far forward, as in Lizards, neither the palatine nor the pterygoid bones uniting to prolong the nasal passage back- wards, and give rise to secondary posterior nares, as in existing Crocodiles. The teeth referred to Stagonolepis have short, swollen, obtusely pointed crowns, like the back teeth of some existing Croco- diles; they sometimes present signs of wear. The scapula resembles that of recent Crocodiles; the coracoid is short and rounded like that of the Ornithoscelida and of some Lizards, such as Hatteria. The humerus is more Lacertian than in existing Crocodiles. The ace- tabular end of the ischium resembles that of a Lizard, and the rest of the bone is shorter dorso-ventrally and longer antero-posteriorly than in living Crocodiles, thus resembling that of Belodon. The latter Reptile, from the Upper Keuper of Wiirttemberg, is the nearest ally of Stagonolepis; both are members of the same natural group, and this must be referred to the order Crocodilia, which was described as differing from other Reptilia as follows:—The trans- verse processes of most cervical and thoracic vertebra are divided into more or less distinct capitular and tubercular portions, and the proximal ends of the corresponding ribs are correspondingly divided ; the dorsal ends of the subvertebral caudal bones are not united; the quadrate bone is fixed to the side of the skull; the pterygoids send forward median processes which separate the palatines and reach the vomer; there is an interclavicle, but no clavicles; the ventral edge of the acetabular portion of the ilium is entire or but slightly ex- cavated; the ischia are not much prolonged backwards, and the pubes are directed forwards and inwards; the femur has no inner trochanter, and the astragalus is not a depressed concavo-convex bone with an ascending process. There are at least two longitudinal rows of dorsal dermal scutes. The Crocodilia are divided by the author into three sub-orders :— I. Parasucuta, with no bony plates of the pterygoid or palatine bones to prolong the nasal passages; the Hustachian passages en- closed by bone ; the centra of the vertebree amphiccelian ; the cora- coid short and rounded; the ala of the ilium high, and its acetabular margin entire ; and the ischium short dorso-ventrally and elongated longitudinally, with its acetabular portion resembling that of a Lizard.—Genera: Stagonolepis, Belodon. II. Mrsosucuia, with bony plates of the palatine bones prolong- ing the nasal passages, and giving rise to secondary posterior nares ; a middle Hustachian canal included between the basioccipital and basisphenoid, and the lateral canals represented only by grooves ; vertebral centra amphiccelian ; coracoid elongated ; ala of the ilium lower than in the preceding, higher than in the next sub-order, its acetabular margin nearly straight; ischium more elongated dorso- ventrally than in the preceding group, with its acetabular margin deeply notched._-Genera: Steneosaurus, Pelagosaurus, Teleosaurus, Teleidosaurus, Metriorhynchus (Goniopholis?, Pholidosaurus ?). Jil. Husucuia, with both pterygoid and palatine bones giving off Geological Society of London. 277 plates which prolong the nasal passages; vertebral centra mostly proccelous ; coracoid elongated ; ala of the ilium very low in front, its acetabular margin deeply notched; ischium elongated dorso- ventrally, with its articular margin deeply excavated.—Genera : Thoracosaurus, Holops, and recent forms. The Mesosuchia are intermediate in character between the other two groups; the Parasuchia, where they differ from the Mesosuchia, approach the Ornithoscelida and Lacertilia, especially such as Haé- teria and Hyperodapedon, with amphiccelous vertebral centra. The Eusuchia, on the other hand, are the Crocodilia which depart most widely from the Ornithoscelida and Lacertilia, and are the most Crocodilian of Crocodiles. After indicating at some length the succession of modifications in the above three groups, the author remarked that if there is any solid ground for the doctrine of evolution, the Husuchia ought to be developed from the Mesosuchia, and these from the Parasuchia, and showed that geological evidence proved that the three groups made their appearance in order of time, in accordance with this view. Thus in the Trias there are the genera Belodon and Stagonolepis of the sub-order Parasuchia. In the Upper Lias we have Steneosaurus, (Mystriosaurus) and Pelagosaurus, the first represented also in all Mesozoic formations up to the Kimmeridge Clay; in the Fuller’s Earth Teleosaurus and Teleidosaurus occur ; in the Kelloway Rock Metriorhynchus, also met with in the Oxford Clay and Kimmeridge Clay; in the Wealden, Goniopholis, Macrorhynchus, Pholhdosaurus, and unnamed Teleosaurians; and in the Upper Chalk Hyposaurus ; all belonging to the Mesosuchia. In the Upper Chalk again the Kusuchia make their appearance, represented by the genera Thora- cosaurus, Holops, and Gavialis (?). How far back the Parasuchia extend in time is not known, but they are not found in any forma- tion subsequent to the Upper Trias. The author described a frag- ment of a skull of a Wealden Crocodile, in which the posterior nares are smaller and situated further back, than in WMetriorhynchus or Steneosaurus. Of the nearest allies of the Crocodilia, the Lacertilia and Orni- thoscelida, the former may be traced back from the present day to the Permian epoch, and the latter from the later Cretaceous to the Triassic epoch. The author discussed the question whether these types exhibit any evidence of a similar form of evolution to that of the Crocodilia. The cranial structure of the Permian Lacertilia is almost unknown, and the only important deviation from the type of the existing Lacertilia in the skeleton is that their vertebre are amphiccelous, not proccelous. With this exception there is no evi- dence that the Lacertilian type of structure has undergone any important change from the later Paleozoic times to the present day ; and this change seems to have occurred earlier in the Lacertilia than in the Crocodiles, as a sacral vertebra of a Lizard from the Purbecks has the centrum concave in front and convex behind. _ With regard to the Ornithoscelida, the author noticed that the researches of American Paleontologists proved the existence of 278 Reports and Proceedings— those Reptiles in abundance in quite the latter part of the Cretaceous epoch. He had himself indicated the existence of various forms of Dinosauria in the Trias. He confirmed his former opinion that Zanclodon from the Upper Keuper of Wiirttemberg is a Dinosaur, and probably identical with Teratosawrus (von Meyer), in which case its affinity to Megalosaurus is exceedingly close. He corrected a statement in a former paper with regard to the ilium of the The- codontosaurians, which he had turned the wrong way, and stated that when regarded in its proper position this ilium is much more Lacertilian than that of IMegalosaurus. From this and other evi- dence of detail he inferred that the Triassic Thecodontosauria were devoid of some of the most marked peculiarities of the later Orni- thoscelida, while the most ornithic of the latter belong to the second. half of the Mesozoic period. The oldest Crocodiles differ less than the recent ones from the Lacertilia, and the oldest Ornithoscelida also approached a less differentiated Lacertian form, the two groups seeming to converge towards the common form of a Lizard with Crocodilian vertebre. Cetiosaurus is also a reptile with a vertebral system like that of the Thecodontosauria and Crocodilia, but with more Lacertilian limbs, and Stenopelyx may be in the same case. It may therefore be convenient hereafter to separate the Thecodonto- sauria, Cetiosaurus and perhaps Stenopelyx as a group, “Sucho- spondylia,” distinct from both the Ornithoscelida and the Crocodilia (or “‘Sauroscelida ”’). Prof. Huxley, in reply to remarks on his paper by Professors Duncan and Seeley, stated that the Indian Crocodile, Parasuchus, was very like Belodon in the jaw and teeth, the scapula and coracoid, the vertebre, the ilium, and the tibia. The tibia had the proximal end like that of a Lizard, the distal like that of a Crocodile. The remains from India furnish a new point of resemblance between the Indian deposits and those of Elgin. With regard to the difference in the position of the nostrils, he did not know that any reason could be given for this, unless the modification might facilitate respiration when the animal was engaged, after the manner of Crocodiles, in drowning its prey; but this would not hold good in the case of the Gavial, which feeds on fish. The food of Stagonolepis was doubtful: the teeth were often more or less ground down; but whatever the food was, it might be an advantage to the animal to be able to breathe when its mouth was full. In reply to Prof. Seeley, he stated that his comparisons were not founded on the skull alone, but on the other principal characters. Purely morphological considerations would not be sufficient alone, but they must enter into the question. As to the older Lacertilia, he had paid some attention to them, and considered that in all their characters they resembled the existing forms; the modern Sphenodon (or Hatteria) of New Zealand was exactly like the Triassic species. The skull in Belodon most closely resembles that of Hylerpeton ? 2. “On the remains of a Fossil Forest in the Coal-measures at Wadsley, near Sheffield.” By H. C. Sorby, Hsq., F.R.S., F.G.S., Pres.R.M.S. Geological Society of London. 279 In this paper the author described the occurrence of a number of stumps of Sigillarie in position and with Stigmarian roots attached to them in the Coal-measure Sandstone in the grounds of the South Yorkshire Lunatic Asylum, and mentioned that the authorities of the Asylum, in order to preserve these remains, had erected two wooden buildings over them. The trees seem to have grown in what is now a bed of earthy clay-like shale; there to have dried and rotted down to the level of the surrounding mud, leaving hollow stumps, to be afterwards filled up with the sand now forming the super- jacent bed of sandstone. The stumps exposed were about ten in number, spread over forty or fifty yards of ground. The smaller trunks have four, and the larger ones eight roots; and the author specially called attention to the fact that, from the position of these” roots, by analogy with existing trees, we may infer the direction of the prevalent wind at the time the trees were growing, and that it appears to have been from the west. 3. “On Favistella stellata and Favistella calicina, with Notes on the affinities of Mavistella and allied genera.” By H. Alleyne Nicholson, M.D., D.Sc., F.R.S.E., F.G.S. The author noticed that Oolumnaria alevolata, Goldf., has been described by Hall under the name of Fuavistella stellata, as pointed out by Milne-Edwards and Haime, and discussed the course to be pursued, another Coral from the Trenton Limestone having been described and figured by Hall and other American paleontologists as Columnaria alveolata, Goldf. The distinction between the two forms consists chiefly in the degree. of development of the septa, these being marginal and rudimentary in the latter species, and reaching nearly or quite to the centre in the true C. alveolata, Goldf. He proposed to refer both to the genus Columnaria, accepting Favi- stella as a sub-genus, and retaining Hall’s specific name for its type. In case of the identity of Favistella stellata, Hall, and Columnaria alveolata, Goldf., being definitively established, he suggested the name of C. Halli for the species described by Hall as C. alveolata. He also described a new species of the genus under the name of Columnaria (Kavistella) calicina. Mr. A. Tylor brought an apparatus for determining the heat evolved by the friction of ice upon ice, with a view to explain an important element in glacier motion. The apparatus, consisting of plates of ice 8 inches square, placed in two wooden chucks 3 inches deep, was enclosed in a double sheet-iron case containing ice and salt, and kept at 32°F. One block of ice was rotated,’ and the other pressed against it. Four pounds of ice were reduced to water at the rate of 14 1b. in an hour, in consequence of the motion, that is by the heat evolved by friction of ice upon ice, the pressure being 2 lbs. on the square inch. Ice evaporates at 32°, and the same quantity of ice was reduced, when still, at about the rate of + lb. in an hour at 32° F. Air at ahigher temperature found its way into the case, and promoted melting. When this experiment was tried in a room at 54° F. with the same apparatus without any 1 One chuck revolved 500 times in a minute. 280 Reports and Proceedings— outer case, the friction of the ice in motion, at the above pres- sure, increased the production of water 31 times above the rate observed when the ice was still and exposed to a tem- perature of 54° F. The amount of heat evolved was nearly as much as with oak moving upon oak well Inbricated, and the coefficient of friction was between 0-1 and 0-2. Glacier motion is impossible without a continual supply of water to lubricate the bottom. No doubt the action of denudation by glaciers produces heat to a small extent. The water obtained by melting the surface of the glacier by the sun’s heat in the glacial period could not be sufficient alone. The position of deep lakes in all parts of the © world in immediate connexion. with mountains and their absence in places away from mountains shows that deep lakes are integral parts of mountains; and, in fact, lakes are deepest exactly where the ; glaciers, once covering the mountains, were in the best position to act as lake excavators. There can be no doubt that all deep lakes in the world, including those in Central Africa, below the Equator, are purely of glacial origin, and that the cold in the Glacial Period was nearly equally intense in the southern and northern hemi- spheres, and the Atlantic was not only lower, but great part of it was frozen. Glacial surface-ice would move much faster than the bottom-ice, and the side-ice than the surface-ice, and therefore fractures would be continually occurring through all parts. The water produced by this great friction of ice upon ice would fall through the fissures to the bottom. He had pointed out that a glacier moved twice as fast when it was eight times as thick,’ and the influence of weight on motion must be considered a most im- portant element. The present temperature of a thin glacier was found by Agassiz, from observation, to be one-third of a degree below freezing; but Mr. Tylor assumed that in such a lake-glacier as he had drawn, and supposed to exist in the glacial period, the tempe- rature might be assumed to be very much below freezing, the greater cold arising from immense evaporation and other causes. He there- fore concluded that the water produced by friction of ice upon ice falling to the bottom of the lake-glacier through fissures would rapidly freeze, and then expanding one-tenth, would impel the glacier (shod or armed with blocks of stone and sand at the bottom) up a gradient of 1 in 20, excavating the Swiss and other lakes 30 or 40 miles long, and 1200 feet deep in this manner. Mr. Tylor calculated that with half an inch per annum of mean excavation over the whole lake- bottom, the lake of Zurich could be excavated in 15,000 years. Prof. Ramsay had pointed out, from geological evidence, that such lakes have been excavated by ice, but he did not indicate how this was mechanically possible (see Quarterly Journal, 1862). Mr. Tylor referred again to his experiment when the pressure was only 2 lbs. on the inch. In a large glacier such as described by Dr. Hooker in the Himalayan range, where the mean gradient of the surface was 40° to 50° and the actual fall was 14,000 feet in five or six miles, Dr. Hooker found great lakes attendant upon the 1 Following the same law as flowing water.—See Phil. Mag. Sept. 1874. Watford Natural History Society. 281 mountains. Supposing the ice was a mile thick, the pressure would be half a ton on the inch, in the Himalaya at least, and the produc- tion of water by friction of ice upon ice enormous. Friction is dependent upon pressure, distance moved, and mass, and independent of velocity of motion. All deep lakes must be referred for origin _ to the Glacial, and not to the Preglacial period. They are the direct consequences of the elevation of mountains in the Preglacial or preceding period. Wartrorp Naturat History Sooty anD HERTFORDSHIRE FIELD Crius.—March 11, 1875. —John Evans, Esq., F.R.S., President, in the Chair. “Qn the Cretaceous Rocks of England.” By J. Logan Lobley. Esq., F.G.S.1 This lecture, an introduction to the Geology of Hertfordshire, commenced with a reference to the great teachings of the work of William Smith and his successors; after which the stratigraphical position of the Cretaceous system, and the vast area of the Earth’s surface within the limits of which Cretaceous deposits may be found, were pointed out. The fan-like extension of the Cretaceous rocks in England, com- mencing at the Dorsetshire coast, is marked out by the Chalk, which, speaking broadly, indicates the eeographical position of the English Cretaceous rocks generally. Commencing with the Wealden, each of the great divisions of the system were described. The Chalk, as the rock of Hertfordshire, was specially dwelt upon. The calcareous Foraminiferal and the siliceous Polycistinal deposits on the bed of the Atlantic canal were explained by the aid of diagrams. The recent researches of the “ Challenger” expedition had revealed the previously unsuspected occurrence of a red argillaceous mud at the bottom of a submarine valley of great depth, and as this was probably the residuum of Foraminiferal tests, the calcareous matter of which had been prevented by some solvent process from reaching these lowest depths, the hypothesis of the organic origin of clays, recently enunciated by Prof. Huxley, had been suggested. The local geology and the geological features of the Thames Valley having been described, the dependence of the plants of a district on its geology, as shown by the presence of the fine beeches for which the neighbourhood of Watford is famed, exemplifies the connexion subsisting between the various natural sciences, the study of which this Society is intended to promote. To Geology, however, and to the study of the Cretaceous rocks of their own county, the members were specially urged to give their attention, since wider views and greatly extended knowledge would surely follow. The lecture was illustrated by diagrams, maps, and fossils, and under the microscope recent, as well as fossil (Chalk) Foraminifera, etc., were exhibited. 1 The first communication to the Society. 282 Correspondence —Colonel Greenwood. CORRESPONDENCE. DENUDATION OF THE WEALD. Sir,—Mr. Kinahan in his book “ Valleys, and their Relation to Fissures, Fractures, and Faults.” robs me of the doctrines of Rain and Rivers, and gives them to Messrs. Foster and Topley. I write to beg space to protest against this. Page 195, he says, ‘‘ We will specially refer to Messrs. Foster and Topley’s paper on it (the denudation of the Weald), as these observers have carefully examined. the geology of the country,” and he quotes the title of their admirable paper ‘“‘On the Superficial Deposits of the Valley of the Medway with Remarks on the Denudation of the Weald (Quarterly Journal of the Geological Society of London, November, 1865, p. 448).” Page 460 of Messrs. Foster and Topley’s paper commences thus: “Part II. On the Denudation of the Weald. Having now described the chief phenomena connected with the superficial beds of the Medway valley, we will pass on to consider the light which they throw upon the much-disputed question of the ‘ Denudation of the Weald.’ We think it will be conclusively shown that ‘rain and rivers’ have been the main agents in producing the present form of the ground.” In the ten remaining pages of Part II., my name on “rain and rivers” is mentioned ten times. And the paper ends as it began. ‘Conclusion. In conclusion we will revert to the main points discussed in the paper. After describing the gravel of the Medway valley, we have endeavoured to prove that an old river gravel of the Medway occurs 300 feet above its present valley. We have then shown that if this fact be admitted, it follows that so large a denudation has been effected by ‘rain and rivers,’ that there can be but little difficulty in supposing the present form of the ground in the Weald to have been produced entirely by these agents.” I shall be satisfied, Sir, if you will allow me space for this protest. But I send the following in case it may be thought suitable to your pages :— Page 200, Mr. Kinahan says, “‘ If the Weald valley was solely due to subzerial (so spelt) denudation, there ought to be deposits of chalk flints over the whole area, and not only on the newer beds.” The flints are gone where they ought to have gone, and where by the laws of nature they must go—into the rivers. And they have been carried by the rivers to the sea-shore, or towards the sea-shore. At page 47, “Rain and Rivers,” I have traced them northward, southward, eastward, and westward. But since then, Mr. Mylne has published his beautiful geological map of ‘London and its Environs.” Mr. Kinahan may see there terraces of flint from 10 to 100 feet above the present level of the Thames. Besides Kensington - and Hyde Park, the entire of ancient London, St. Paul’s, the Mansion House, and the Bank, stand on these vast accumulations of river flint. But the bed and the sides of the valley at London should be London-clay. The flints have been brought by the river. And from whence? Part from the Weald Hill, through the gorges Correspondence—ev. O. Fisher. 283 of the Wey and Mole; part from the gorge through the Chiltern Hills which flood Oxford and the soft Oolitic valleys. But for the sea-shore, let Mr. Kinahan examine Romney Marsh, the Delta of the Rother, formed by the wash down of the very highest part of the Weald Hill, Crowborough Beacon, 800 feet high. At Hythe, Dungeness, and Pevensey, he will find the flints with which he would require “the whole area” of the Weald to be covered. But from the top of Crowborough Beacon, the centre of the Weald, how many hundred feet of Hastings sand, Weald clay, Greensands, Gault, Chalk marl and flintless Lower Chalk have been washed away by rain and rivers since the last speck of upper flint-bearing chalk vanished? The flints which remain “on the newer beds” of the Weald (except those from the more recent denudation of the face of the chalk slope) have been caught on the low flat soft valleys of the Weald clay behind the hard gorges of the Greensand, and in the soft valleys of the Gault behind the hard gorges of the Chalk. When the beds of these gorges were lowered, the sides of the alluviums, no longer overflowed, were denuded, and the alluviums cut back into terraces. But their flat tops remain till the terraces are entirely cleared away. The formation of these terraces has been always going on at heights decreasing directly as the lowering of the beds of the gorges and valleys. That it is going on now may be seen from the deposit of new alluviums with drift gravel at the levels of the present overflows of the rivers. The same thing may be seen on the opposite side of the Greensand hard gorge below Farnham, where the Wey runs into instead of out of the Weald, and deposits vast quantities of drift gravel and alluvium in the soft valley of the Gault. This, also, is going on now. Rivers are the roads which gravels travel to the sea, though they may be arrested for thousands, nay millions, of years in passing alluviums. Witness the terraces of the Fraser River, etc., which are only gigantic effects of what caused the Medway terraces. That is, throughout the wide wide world, atmospheric disintegration and the erosion of rain form a flat valley in the soft strata behind each harder stratum. Hvery flood is then checked at the gorge of the hard stratum, and overflows and deposits on the soft flat. When the bed of the hard gorge is lowered, the bed in the soft valley behind is also lowered, and the flooded river, instead of overflowing, cuts back its alluvium, which remains as two terraces. Messrs. Foster and Topley mistake in supposing (pp. 470, 471) that a rise of the land is necessary for the deepening of the river-bed. It would only be necessary for those parts of rivers whose beds are at the level of the sea. GroRGE GREENWOOD, Colonel. Brookwoop Park, ALRESFORD. SUBMERGED FORESTS. Srr,—Submerged forests and the facts connected with them are important, as offering indications of the latest geological changes. Colonel Greenwood’s theory, to which he recalls attention in your last Number, is an attempt to account for them without any sinking 284 Correspondence—fev. O. Fisher. of the land or rising of the sea. He thinks that the formation of a bar of shingle across the mouth of an estuary would admit of the surface behind it being dry, although it should be below high-water mark; and that a forest might grow there. One sees marsh land in such positions, but unless there are instances of trees of the same kind as those found in submerged forests now growing below high- water mark, it seems doubtful if they grew there formerly. But the important question is, what have been the relative movements of land and sea since these forests were green? Can we correlate changes of level indicated by other phenomena with such as must have raised or depressed these forest lands. Mr. Godwin-Austen, in his paper “On the Superficial Accumulations of the Coasts of the English Channel, and the Changes they indicate,”? arrives at the conclusion, from marks impressed upon the hard rocky margins of the Devon and Cornish coast, that there has been “a change of level, which, so far as elevation is concerned, is necessarily the most recent which has taken place on this section (Dartmouth), and which we may estimate at eight to ten feet.” A depression of that amount, he remarks, ‘“‘ would convert the valley of the Exe into a salt-water estuary, and account for the beds of Mactra, Tellina” (que Scrobicularia) and Cardium found at Alphington.” And he states that this movement has been a uniform one throughout, and extends over the area of the German Ocean. Now the remarkable thing is that we have, in every case that I have seen, evidence of such a depression wherever a submerged forest exists. The stumps of the trees are always enveloped in, or covered by, a mud, full of dead shells of Scrobicularia piperata, Cardium, and other estuarine shells; generally of large size. This deposit is laid bare by the erosion of the waves at the present day, pari passu with the uncovering of the forest itself, as the beach is thrust forward over the marshes. This clay, under the name of “ Buttery clay,” with its usual shells, extends over a great part of the fen land of this neighbourhood, where they spread it over the peaty soil to give it consistency. Beneath it are the remains of forest trees of large size, which sometimes, as the soil sinks through the effect of drainage, protrude above the surface, so that they require to be dragged out by horse power; otherwise they obstruct the plough. There is a detailed account of a submerged forest at Porlock Bay, by Mr. Godwin-Austen, in which the points usually connected with these deposits are excellently brought out.2?__ Colonel Greenwood’s theory will not explain the, I believe universal, presence of the Serobicularia clay covering the old fossils ; while this answers exactly to the depression since balanced by the 8-10 foot elevation established on other grounds by Mr. Godwin- Austen. That elevation has brought the forests with their estuarine envelopes to the level of present half-tide. But they have been eight or ten feet lower than they are now, and consequently fully “submerged.” It seems to me, then, that they are justly entitled to their old appellation, and that it isa mistake to suppose that they 1 Journ. Geol. Soc. vol. vii. p. 118. 2 Journ. Geol. Soc. vol. xxii. p. 1. Correspondence—J. OC. Ward. B86 occur without any sinking of the land or rising of the sea. And I, for one, agree with Mr. Kinahan, that they are “ submerged”’ at the present day, in so far that they are below the level suitable to the growth of trees, of the kinds of which they consisted. A singular fact about these old forests that requires explanation is their almost universal occurrence at a certain uniform level of flat land. It might otherwise have been expected, under these circumstances, that they would have grown upon a surface of silt, deposited by water action. But, as far as my observation goes, they usually grew upon the clay, which forms the bed rock of the locality. At Selsey it is distinctly weathered. How came these tracts of uniform level to exist at so many localities ? At some places, however, there is a gravelly bed beneath the forest, and, in such, at Barnstaple occur flint knives. There is a submarine forest at a much lower level indicated in Mr. Godwin-Austen’s paper first referred to (section no. 1, pl. vi.), which must, I think, belong to a period antecedent to that of the forests of which I have been speaking. I would take the liberty of referring upon the above and kindred topics to my paper on “The Warp,” in the Journal of the Geo- logical Society, vol. xxii. p. 553. _ O. FIsHER. Haruron Rectory, CAMBRIDGE. A VOICE FROM THE PAST. Sir,—I suppose there has been no more thorough and accurate observer of geological phenomena than the late Prof. Sedgwick. On going through his papers of nigh half a century ago, on the English Lake District, 1 am constantly struck with his minuteness of investigation, and his careful and logical deductions. Had he been blessed. with a good ordnance map, there would have been comparatively little general work left for the Geological Survey to accomplish. The following extract from one of the late Professor’s letters, dated May 24th, 1842, is interesting in the present day, when land-ice is supposed by some to have been equal to any task :—‘‘No one will, I trust, be so bold as to affirm that an uninterrupted glacier could ever have extended from Shap Fells to the coast of Holderness, and borne along the blocks of granite through the whole distance, without any help from the floating power of water. The supposition involves difficulties tenfold greater than are implied in the phenomenon it pretends to account for. The glaciers descending through the valleys of the higher Alps have an enormous transporting power: but there is no such power in a great sheet of ice expanded over a country without mountains, and at a nearly dead level.” The various Arctic voyages made of late years have shown that the drifting of pack-ice is more often due to winds of constant direction acting upon the many slight irregularities of the ice, than to currents affecting great thicknesses of the watery strata below, 1 See the writer’s paper on Bracklesham Bed, Journ. Geol. Soc. vol. xvii. p. 74, note. 286 Correspondence— R. Mallet, R. Tate. Perhaps this has scarcely been taken into sufficient account by those who have considered the transportation of boulders by floating-ice. If there really was a considerable mid-glacial submergence—of which I cannot but think there is ample evidence both in Cumbria and in Wales—is it not quite possible that westerly winds prevailed at certain seasons, which might drift large quantities of boulder- bearing ice from the Shap district without the aid of permanent ocean-currents ? The difficulties involved in the theories of Messrs. Croll, Belt, Goodchild, and others of the same extreme school, certainly press upon me—and I think I may say also upon others of my colleagues—increasingly, as the country becomes more and more familiar in its features. It is indeed a most startling thought, as one stands upon the eastern borders of the Lake-mountains, to fancy the ice from the Scotch hills stalking boldly across the Solway, marching steadily up the Eden Valley, and persuading some of the ice from Shap to join it on an excursion over Stainmoor, and bring its boulders with it. The outlying northern parts of the Lake-district, and the flat country beyond, have indeed been ravaged in many a raid by our Scotch neighbours, but it is a question whether, in glacial times, the Cumbrian mountains and Pennine chain had not strength in their protruding icy arms to keep at a distance the ice proceeding from the district of the southern uplands, the mountains of which are not superior in elevation. Let us hope that the careful geological observations which will doubtless be made in the forthcoming scientific Arctic Expedition will throw much new light on our past glacial period. J. Currton Warp. Keswick, April 26th, 1875. THE MECHANISM OF STROMBOLI.! Sir,—It is quite immaterial to the validity of the mechanism of Stromboli which I have suggested (Proc. Roy. Soc. 1874) whether the bottom of the crater be 300 to 400 feet, or be 2,000 feet above the sea-level, as no physicist reading the above paper can fail to see. Westminster, 19 May, 1875. Rost. Mazer. SPHENONCHUS HAMATUS, A RH ATIC FOSSIL. Str,—I beg to record my discovery a few days since of a large Sphenonchus, in the bone-bed of Aust Cliff, a genus hitherto unknown in the Rhestic formation. I have compared it with a specimen of S. hamatus in the Bristol Museum, obtained from the Blue Lias at Keynsham, (an unrecorded find, by-the-bye), and fail to find any points of difference, except that of size; the Rhetic specimen being about half as large again as the other, which agrees well with the Lyme Regis type figured by Agassiz. Rape Tare. 92, Crry Roan, Bristot, May 19th, 1875. 1 See Mr. Poulett Scrope’s critical examination of Mr. Mallet’s paper in the Grou. Maca. for 1874, New Series, Decade II. Vol. I. pp. 529-542. See also Mr. J. W. Judd’s article on Stromboli, Grou. Mac. 1875, Dec. II. Vol. II. No. V. for May, p. 210. Correspondence—G. H. Kinahan, Prof. Hull. 287 RED ROCKS OF TYRONE AND DERRY COUNTIES. Str,—From Mr. Ketley’s paper on the coals under the “Red Rocks” of South Staffordshire, we learn that the Coal-measures under certain circumstances may be made up of red strata, and that it is erroneous to class all such red rocks as Permian or New Red Sandstones. In the Counties Tyrone and Derry there are some of these doubtful aged rocks. The highest of them under the Chalk, called “Redfre,” seem to lie unconformably on the others, and probably to belong to the New Red Sandstone. The older ones were in part classified by the late General Portlock as Old Red Sandstone, and in part as Carboniferous, but now the general belief seems to be that they belong to the Permian. During a brief examination of the country made some time since, J found in places among the Coal-measure rocks (which I supposed to be the equivalent of the lower Scotch Coal-measures, such as occur in the neighbourhood of Edinburgh) considerable tracts of these red strata, which led me to suspect that most, if not all, these red rocks of the Counties Tyrone and Derry are portions of the associated Carboniferous rocks. Time, however, did not allow me to investigate the country minutely. In favour of their being Permian, there are fossils said to belong to the Permian type, that have been found in at least one locality ; but are not these so-called Permian fossils very like stunted and ill-favoured forms of the Carboniferous fossils, and like what we might expect to meet in those portions of the Carboniferous sea, where the water was im- pregnated with iron or some other substance adverse to the growth and proper development of animal life ? G.. H. Kinawan. THE VOLCANIC DUST OF BARBADOES, 1812. Sir,—When reading the interesting paper by Dr. Flight on the “History of Meteorites”! in the April Number of the GronoeicaL Magazine (p. 159), I found a reference to the composition of the Volcanic Dust which fell on the Island of Barbadoes during the great eruption of the volcano of Le Souffrier, in St. Vincent, in 1812, described by Humboldt, and more recently by Lyell,’ Daubeny,’ and Scrope.t Having just received some of this dust, placed in my hands for microscopical examination,—which had been collected by a relative of mine® at that time resident in Barbadoes,—I have thought it may be worth while. to note the results. It may be as well to premise, that this eruption was preceded by the great earthquake of Caraccas in Venezuela,® which commenced on the 26th March of the same year, and was felt all along the valley of the Mississippi and the West Indian Islands. The eruption of Le Souffrier took place about a month afterwards, namely, on 27th April, opening by a grand discharge of ashes, which commenced to 1 Dr. Flight’s articles on Meteorites commenced in Grou. Mace., Jan., 1875. 2 « Principles of Geology,” vol. i. 3 Daubeny, Volcanos, 2nd edit. p. 469. * Scrope on Volcanos, p. 432. 5 The late Mrs. C. T. Cooke, of Cheltenham. 6 See Grou. Mac. 1871, Vol. VIII. p. 348. 288 ; Miscellaneous. fall on the night preceding the 1st May on Barbadoes, rendering the sky dark at noonday, and finally, after three days continuance, covering all the surface of the country with a hideous pall of dark brown ashes, which it took many a day to remove. I well remember hearing my deceased relative describe the horror and consternation which pervaded the household and district on that fatal May Day, which realized to the mind one of the plagues of Egypt. The dust appears to the naked eye as an exceedingly fine impalpable powder, of a rich brown colour; with an ordinary pocket-lens the grains are distinctly visible. The distance from the volcano to Barbadoes is exactly 100 English miles, and, as Daubeny observes, it is remarkable that the ashes were carried to Barbadoes notwithstanding the east wind which was blowing at the time, proving the existence of an upper and counter atmospheric current. As the volcanic mountain rises 4,740 ft. above the sea, the dust may have been blown to a height of 8,000 to 10,000 ft., and thus come within the influence of an upper current of air. With an objective power of fifty-five diameters, the dust is seen to consist of angular, or subangular grains of a translucent reticulated mineral amongst which are dispersed black particles, sometimes angular, and a very few others of a rounded form and bronze colour. On examining the translucent grains with the polariscope, and under several different magnifying powers, it became evident they consist of felspar. The structure is reticulated and in a very few cases banded ; but owing to the irregularity of the forms of the grains, I was unable to determine to which class of the felspars they are referable. My impression is that they are the dust of sanidine, and of a small proportion of plagioclase; such, in fact, as would result from the pounding up of trachyte. The black grains are those of magnetite, and on placing a small magnet near the dust, a movement is im- mediately observed amongst the grains, which increases in intensity as the magnet approaches contact. It would be interesting. to determine chemically whether or not titanic acid is present, but I fear the grains are too minute for such © a determination. The bronze-coloured grains are probably pyrites ; they are opaque, but slightly translucent around the margin. I did - not observe any other mineral substance. Epwarp Hutt. GEOLOGICAL SuRVEY oF IRELAND, DUBLIN. MiscEeLLanzous.—Royat Socrrery or HEpinsurea.—On the dth April, the ninth ordinary meeting of the present session of the Royal Society was held in the Royal Institution— Professor Kelland, Vice-President, in the Chair. Professor Geikie addressed the Society, explaining at length the grounds on which the Council had awarded the Neill prize for the triennial period 1871-74, to Mr. Charles William Peach for his contributions to Scottish Zoology and Geology, and for his recent contributions to fossil Botany. Mr. Peach, the Professor said, had materially increased our acquaintance with the marine fauna of the British seas; he had made known the nest-building habits of fishes and mollusca, and had made important contributions to fossil botany and paleontology. Professor Kelland, in presenting the medal, said that Mr, Peach had cultivated science disinterestedly and in the face of nature, and not from books at second-hand. THE GEOLOGICAL MAGAZINE. NEW (SERIES) DECADE Ti (VOE: It, No. VII.—JULY, 1875. ORIGINAL ARTICLIES. ——— I.—Norrs oN THE VoLcANIc ERuptTions IN ICELAND. By G. Poutzrr Scrorz, F.R.S., F.G.S., etc., ete. CELAND—that land of Frost and Fire, an island which, though as large as Ireland, is, apparently, but a crust of hardened lava over a seething cauldron of the same substance, bearing on its frozen sur- face eternal snows and glaciers—has been this year in extraordinary commotion, socially and politically, as well as physically. It has celebrated the millenary of its colonization, and for the first time in this long period received a visit from its sovereign; while it has been so devastated of late by frequent fiery eruptions, the ashes from which destroy its pasturage—the only resource of the islanders—as to have driven them, it is said, to the desperate resolve to emigrate en masse, and leave their native land for a safer, at least, if not a more genial residence, in the far North-West of the American Continent. Within the last month intelligence has arrived of eruptions of a more than ordinary violence having occurred in the high snowy dis- trict to the north of Vatnajokull. The following extract from the Scotsman, under date of May 21st, is “from an occasional correspondent” of that paper: “The volcanic disturbances in the north of Iceland (mentioned in the Scotsman in April) still continued when the last mail from that part of the island reached Reykjavik. There seems to be a line of volcanic activity all the way from Vatna- jokull to Skjalfandafloi, a distance of about 100 miles. Volcanic outbursts on this line have been frequent during the last four years. They have, however, been con- fined to the south end of the line in Vatnajékull till the present year. During the first three months of this year the volcanic outbursts have continually been moving northwards, but always continuing in the same line. They are just now traversing the sandy deserts lying between the inhabited district Mijvatns sveit on the west and the river Jékulsa on the east. On the 12th of March, the spot where one of these outbursts occurred was visited by some of the inhabitants of Mijvatns sveit. This spot is close to the outburst mentioned in the Scotsman, just about a mile further to the north. There were fifteen different craters close to each other, and during forty-eight hours they had thrown up a wall, or ridge, of lava about sixty feet high, and further covered the ground round about them with heaps of lava, thus forming a lava tract about five miles long, and half a mile broad. Another visit was made to the volcanic line on the 4th of April. The locality visited on this occasion was south-east of a hill called Burfell, and a short distance west of the river Jokulsé. Here three large craters were found, and on the west side of them a large. rift had been formed and the ground sunk about 18 feet. The craters were here, as at the other place, in a straight line from north to south, the northernmost being the largest. ‘This crater had an oblong form. Its mouth, or the opening from which the fire issued, reached the enormous length of 600 yards. DECADE II,— VOL. II.—NO. VII. 19 290 G. Poulett Scrope— Volcanic Eruptions in Iceland. From different parts of this wide opening columns of liquid fire were continually rising to the height of 300 feet. Sometimes as many as thirty such columns rose together - ata short distance from each other. The outbursts were intermittent. At one time many columns suddenly rose at the same time, then subsided, and after a few minutes rose again. Inside the enormous cauldron there seems to be a lake of liquid fire, which the steam throws up to the height mentioned. The columns seem quite solid until they have reached their greatest height, then the tops spread out and scatter a rain of molten lava all round. The volcano seemed to act on the same principle as the hot springs, with this difference, that the volcano sent forth columns of liquid Jire, or molten lava, instead of hot water, and the columns rose to a far greater height than that of the hot springs. That it was steam which sent the liquid fire into the air is further proved by the fact that the outbursts were accompanied by a tremendous roar, as if hundreds of steam-boilers were acting together, and con- tinual reports were heard in the crater when the steam bubbles were bursting. This eruption was accompanied by no smoke, or discharge of ashes, but a semi-transparent steam-cloud rested over the whole. As this eruption has to this time been confined to the uninhabited parts, and has not discharged any ashes, it has not done any damage; but should the outbursts follow up the same line much further to the north, both the Mijvatns sveit and the districts further north will be in the greatest danger. On the 29th of March an outburst took place somewhere in the interior, most probably near the sources of the Jékulsa, and a large quantity of ashes, to the depth of three inches, fell in the east of Iceland, in the districts on both sides of the river, or rather lake, called Lagarflj6t, and in the middle of the day the whole neighbour- hood was enveloped in total darkness. The ashes from this outbreak were carried as far as Norway. This eruption, although further away from the inhabited parts, has caused much more damage than the other ones, because the pastures have been destroyed in the districts where the ashes fell, and the sheep have to be driven away to other districts. According to the last accounts fromthe north, all the volcanic vents which have been opened this year seemed to be in full activity. The glare of the fire was seen in districts more than a hundred miles distant from the actual seat of the volcanos, and even in the south some slight shocks of earthquake are felt. The weather still continues uncommonly mild and fine, and by some this is attributed to the volcanic fires.” This statement does not appear to emanate from any scientific authority ; and in some respects it is not quite clear. The main fea- tures of the phenomena described, and the most remarkable, are: 1. The arrangement of the points of eruption in lines stretching from south to north, on one of which no less than fifteen different craters (cones) were thrown up close to each other. 2. On a continuation of the same line the further production of three large crater-cones, one of them having an oblong form, mark- ing a trench or rent no less than 600 yards in length, filled with liquid fiery lava which was thrown up in columns of liquid fire, from successive points, to the height of 300 feet; as many as thirty such columns rising together at a short distance from each other at the same time. Such an eruption must have given rise, not so much to separate regular cones of scorize, as to a continuous ridge-shaped hill, of which examples not unfrequently occur in volcanic districts. 3. This eruption, which is said to have been in activity on the 4th April, discharged xo ashes; while on the 29th March another out- burst, more to the east, produced clouds of ash which not only covered the east of the island, but were carried as far as Norway and Sweden. This latter fact is confirmed by Prof. Kjerulf, of Christiania, who examined the dust, and found it to consist of finely ea ie ileus Geol.Maég 1875. NEW SERIES Decade II. Vol. IL Pl. VIL. J.S.Gardner del et fh W. West & C° imp. Fossil Aporrhaide. J. Starkie Gardner—On the Gault Aporrhaide. 291 comminuted pumice, proving the lava, from the trituration of which _ it proceeded, to have been a highly siliceous trachyte. ‘The apparent absence of ash-clouds from the first-named eruptions may perhaps be attributed to the winds prevailing at the time having driven them in the direction contrary to the observer’s line of sight, since it is difficult to suppose that continuous explosions of fragmentary lava, at first Jiquid, but soon of course consolidated in that cold climate, should not, by the repeated hurtling together and trituration of their substances in the air, as they rose and fell successively, have produced considerable clouds of ash, that is, of comminuted lava or pumice. We shall look with some interest to the further and more detailed accounts of these Icelandic eruptions, which may be expected to_ arrive before long ; especially as several English explorers, and par- ticularly Mr. Watts, who last year penetrated the Vatnajokull, which no one, it is supposed, not even a native Icelander, had ever trodden, are at present re-exploring the same interesting district. Il.—On THE GAULT AporRHAIDS. By J. Srarxiz Garpner, F.G.S. (PLATE VILI.). (Continued from page 203.) Group 4 (continued)—APorRHAis PaRrKINSONI, var. Cunningtoni, Gardner. Pl. VII. Fig. 1. Shell elongated, spire composed of many convex whorls, which are very finely striated, 2 or 3 of the striz being very distinct and wide apart in front of the sutures. The last 2 whorls have 10 or 11 and the other whorls have 14 or 16 well-marked ribs, with occasional var- ices. On the last whorl there is a slight angularity in place of keel. The wing exactly resembles that of A. Parkinsont, and in this may be distinguished from that of A. Mantelli. The anterior canal is moderately long. The form here described is intermediate in character between A. Parkinsoni and A. Mantelli, differing in the number and development of the ribs from the former and in the shape of the wing from the latter. The specimen was obtained by Mr. Cunnington from the Upper Greensand at Devizes, and is now in the British Museum. The next species described cannot be placed satisfactorily with any of the groups just indicated. From the species being founded on an unique shell, it is just possible that it may be an abnormal variety. AporrHais MAcCRostToMA, Sowerby. Pl. VII. Fig. 2. Description.—Shell elongated, spire composed probably of ‘7 or 8 convex whorls. Each whorl has two principal keels, which are pro- longed on the last into ridge-like supports to the wing. The first whorl remaining on the specimen now described (probably the 5rd or 4th from the apex) is strongly ribbed transversely, and the two carine are very salient ; the next whorl has only traces of the ribbing left in the form of widely separated tuberculations on the carina. On 292 J. Starkie Gardner—On the Gault Aporrhaide. this and the penultimate whorl a subordinate keel appears between the two principal ones; the body-whorl is ornamented in addition by spiral striz arranged 1 above, 3 between, and 6 below the carinz —a sutural keel also becomes visible. The wing, which is exceedingly expanded, is supported by 3 strong ridges or spines, 2 of the spines being prolongations of the carinz mentioned above, and the third taking the place of the anterior canal. There were also two intermediate spines rising from the margin of the wing and dying away before reaching the body of the shell, only one of these remains on the figured specimen. The wing had thus five points. The middle spine is unfortunately broken away, but there is no doubt that it was present on the shell. The anterior spine or canal is curved backward, and there is a curious and un- usual triangulariform expansion to the left of the canal. After careful examination under the microscope, the slightest trace only (and I am most doubtful whether it really is a trace) of at- tachment of the wing to the spire is apparent, and I am now inclined to think that the wing expansion did not extend up the spire, but that its upper termination shown in the figure is the actual posterior margin of the pterygoid process. History.—Sowerby figured this shell in the Geol. Trans., 2nd series, vol. iv. pl. xviii. fig 28. No second specimen I believe has been found. ‘The fossil figured by Briart and Cornet as this species in no way resembles it. Locality.— Blackdown. Iam indebted to the courtesy of Mr. H. B. Tawney for the op- portunity of examining this unique shell, as well as the original specimen of A. retusa, figured by Sowerby on the same plate. I may here state that this latter is identical with the Folkestone and Lyme Regis shells. Since writing these notes on Aporrhaide, I have had an oppor- tunity of examining the Neocomian forms, descriptions of which, together with those of a few species formerly unknown to me, will be found in the following supplement. SUPPLEMENT. Group 1 (see p. 52). Pl. VII. Fig. 3. AporrHais Morgausiana, D’Orb. Description.—Shell thinner and more elongated than that of A. Fitton, and less delicate than A. retusa, the spire being composed of 5 or 6 whorls, ribbed spirally and forming a slightly convex angle. As in most species of this group, the last whorl only is seen to be bicarinated, the anterior keel being hidden by the suture in the re- mainder. The whorls composing the spire are very angular, much more so than in 4. Fittont. On the last whorl there are at least 2, generally 3 spiral strize between the keels, 3 striz above the posterior keel, and 4 or 5 below the anterior keel. The two keels are not very prominent, and are somewhat rounded, the posterior one pre- dominates, and is slightly tuberculated. ‘The keels are continued J. Starkie Gardner—On the Gault Aporrhaide. 293 into long curved digitations, the digitations being accompanied for a short distance by expansions of the shell, and being less angular and acute than those of A. retusa. There is a short posterior canal ac- companying and attached to the spire, but I am not fully acquainted with the length and development it attains. The anterior canal is bifurcated near its commencement, and is then abruptly recurved to the left. There is a well-marked sinus between this canal and the anterior digit—another deep round notch between the two digits of the wing. The wing has altogether an angular appearance. This shell is readily distinguished from 4. Fitton, with which it 1s some- times found associated, by the more elongated and angulated spire, and the number of ribs on the last whorl. _History.—There is very little doubt that this is the Pt. Moreau- siana of D’Orbigny, Terr. Crét. vol. ii. p. 3801, pl. 211. It is the Pt. retusa of Fitton, Quart. Journ. Geol. Soc. vol. ii. from the “Cracker rocks,” and it is probably identical with the shell described by Pictet and Campiche in the Terr. Crét. de Ste.-Croix, p. 579, as Pt. bicarinata, Sowerby. These learned authors noticed the tendency of the posterior carina to predominate, and their figure 7, pl. xci., shows the bifurcation of the anterior canal. The figure of Pé. ma- crostoma, pl. ii. fig. 8, of Briart and Cornet’s Meule-de-Bracquegnies may also have been drawn from a fossil of this species. It is the Pt. retusa from Atherfield, of Mantell, Forbes, Morris and other British authors. Distribution.—Atherfield (Brit. Museum and Geol. Soc. Museum), and Peasemarsh, near Guildford (in Mr. Meyer’s collection). It is not possible for me at present to define its continental range. Avorruais Firront, Forbes. Pl. VII. Fig. 4. Description.—Shell rather thick, shaped very like the preceding, the spire being composed of five spirally striated whorls. The penultimate whorl has three keels and several striz visible, which disappear on the upper part of the spire, or, more correctly speaking, are reduced to the same prominence only as the striz ; the upper whorls are inflated and ornamented with five or six equal spiral lines, which are decussated by lines of growth. On the body-whorl the carinz and strie are much coarser, more prominent, and more rounded than in the last described species. Above the posterior keel there are two faint strie ; between the keels is a single pronounced riblet; below the anterior keel, are three strongly-marked striz, and beneath these are one or two more faintly marked lines. The two carinz are more or less, but sometimes very strongly tuberculated, and are continued into strong linear curved digits; there is also a long and elegant posterior canal attached to and extending far be- yond the spire; it is recurved gracefully to the left. There is an expansion of the shell on the upper side of the posterior digit ac- companying it for a short distance, and terminating abruptly in an angle—a similar expansion occurs on each side of the anterior digit. The anterior canal is long and recurved, and has not been observed ever to become bifurcated. The sinus is well marked. 294 =. Starkie Gardner—On the Gault Aporrhaide. History.—Described by Forbes as a Pteroceras in 1845 in the Quart. Journ. of the Geol. Soc. vol. i. p. 351, pl. iv. fig. 6; referred to by Fitton in vol. iii. as occurring in bed 5a of the “ Cracker nodules ; ” and figured by Mantell in the Geology of the Isle of Wight, 1847, as Pt. retusa. The references to Pt. retusa from Atherfield, in other works, should be read as A. Moreausiana. The original speci- men figured by Forbes is in the Museum of the Geological Society, it is remarkable for the great prominence of the tubercles on the Carine. Distribution.—Atherfield ; not hitherto noticed on the Continent. Apporuais nisTocuina,! Gardner. Pl. VII. Figs. 5 and 6. Description.—Shell apparently thinner than that of the last species, but having the same general form. It is bicarinated and finely stri- ated, the front part of the shell is larger than that of A. Moreausiana, and has more and seemingly better defined striex. The spire is depressed, with rounded whorls. The stria are arranged three or -four on the region above the posterior keel, four between the keels, eight or nine anterior to them. The keels are prolonged into digita- tions, which sustain or strengthen a broad expanded wing, continued to the apex of the spire; of these digits the more anterior is very straight and projected downward, the second is curved upward. Some of the striz above the posterior keel of the body-whorl are continued on the wing, and follow the curves of the adjacent digit. There is, probably, a posterior canal of the same size, and recurved in the same manner as in A. Moreausiana. The anterior canal is not very distinct on the specimen figured, but it seems accompanied by a continuation of the expanded wing to near its end. There is the characteristic sinus between the anterior canal and the front digit, the margin of the wing being otherwise entire. This shell is very like A. Moreausiana, but the shape of the wing with its entire margin, the rounded instead of angular whorls of the spire, and the downward and straight anterior digit, combine to give it a distinct aspect. The body-whorl is larger in proportion than it is in the two species just described, and this character might seem to identify the numerous casts that are found in the Upper Greensand and Gault. It will be, at all events, safe to. consider casts resembling this shell, and found on the same horizon, to belong to this species, instead of to A. Fittont or A. Moreausiana, which characterize the Lower Greensand. It is distinguished, in common with the two last, from A. retusa by its elongated form, the less relative prominence of the anterior keel, and the number of strie. The casts from Cambridge agree with this in form and in the number of strize below the keels. History.—This species has been variously labelled in different museums—retusa, Fittoni, ete. A good specimen in the Geological Society’s Museum is labelled Pé. Rochatiana, D’Orb., by H. de la Béche, but a reference to D’Orbigny’s Prodrome suffices to show that this is an error. Disiribution.—Found in the Upper Greensand of Devizes, Lyme 1 From iorbs webbed, and xezAos a lip. me . J. Starkie Gardner— On the Gault Aporrhaide. 295 © Regis, and Cambridge, and in the Gault of Folkestone; it would therefore appear to have a wide range. AporRRHAIS GLOBULATA, Seeley. This shell is described at length by Professor H. G. Seeley in the Annals and Magazine of Natural History for April, 1861. It occurs in the Upper Greensand of Cambridge and Ashwell, and resembles those previously described in most particulars, but is of smaller size. ApporHAis OLIGOCHILA,' Gardner. PI. VII. Fig. 7. Description.—Shell broad and ovate ; spire short and obtuse, with five very angulated whorls, the last being equal in depth to the other five. All the whorls possess two strongly-developed keels; though the anterior keel is hidden by the suture on all but the last whorl, on which both keels are particularly distinct. 'The whorls are finely striated spirally; on the body-whorl there are six strie above the keels, three between them, whilst anteriorly it is strongly striated to the canal. The carinz are extended into digits, which support an expanded lip, continued and attached to the spire up to the apex. The canal and digits of the specimens examined are short, and the outline of the lip is angular. It is a much larger shell than any of those described as belonging to this group. History.—As stated in the March Number of this Macazinz, page 124, there is a specimen of this shell named R. Mailleana in the D’Orbigny collection at the Jardin des Plantes. This must, how- ever, be an error, as neither the description nor figure in the Terrains Crétacés resemble it. Locality— Grey Chalk of Lyddenspout, between Folkestone and Dover. 9 Apporruais pacuysoma,” Gardner. Pl. VII. Fig. 8. A small ovate shell, composed of three or four inflated whorls and an expanded wing. The body-whorl is very large in proportion to the whole shell, is rounded, and without carine. ‘The spire is depressed, and the whorls inflated and keel-less. The body-whorl has about fifteen striz, which seem to be finely tuberculated. The columellar lip appears to have been very much incrusted. The aper- ture is crescentic, and the outer lip is developed into two short canaliculated spines, and is terminated anteriorly and posteriorly by rather short and slightly recurved canals, the posterior one being attached only to the body-whorl. In the young state the shell would resemble a globose form of Acteon. It differs from all other Aporrhaide. - Locality.—Grey Chalk of Lyddenspout, where it is rare. Group 4.—AporrHais RoBrnaLpin, D’Orb. VP. VII. Figs. 11 and 12. Description.Shell elongated, conical, spire composed of about eight rather inflated whorls, terminating apically in an obtuse point. The apex under an inch-power microscope is seen to be flattened, the flat region being composed of three inflated, turbinated whorls. * From éavyos little, xetAos a lip. 2 From maxos thick, c@ua. - 296 J. Starkie Gardner—On the Gault Aporrhaide. The fourth, which is the first descending the spire, is seen to be slightly ribbed ; as the whorls increase in size, the ribs, which are narrow and slightly flexuous, become more pronounced, reaching their maximum prominence on the penultimate whorl, where they are 17 or 18 in number; this number is, however, variable, and the ribs are often irregularly distributed; on the last whorl they be- come shortened and tubercular as they approach the outer lip, and form a ridge on the wing ; this whorl is slightly angular or carinated, and generally carries an indication of a second anterior keel. All the whorls are faintly striated spirally, except near the suture, where two or three strie are strongly marked. The outer lip, in adults, is produced into an expanded wing, prolonged posteriorly into an oblique point; the outer margin is nearly straight, and anteriorly there is a slight sinus. The wing is attached to the penultimate whorl. The aperture is narrow and the canal elongated. History.— This shell is generally known as R. Robinaldina of D’Orbigny, described (1843) in the Pal. Fr. Terr. Crét. vol. ii. p. 282, pl. 206, f. 4 and 5. Pictet and Campiche separate the British species from that of D’Orbigny, which has, according to their views, a shorter and thicker spire, whose length does not equal half that of the whole shell, a less number of ribs, and these shorter on the last whorl. They appear in doubt, however, as they add, “ce groupe est difficile et renferme encore plusieurs espéces inédites ou mal connues.” Not having hitherto had an opportunity of comparing actual speci- mens, I am not in a position to decide the question, and reserve comment for a future occasion ; but it is not unlikely, if the forms are really distinct, that they both occur in England, some casts in the Geol. Soc. Museum, from Shanklin and Pulborough, possessing all the characters indicated by Pictet arid Campiche. 4. acuta, P. and C., and R. Alpina, are closely allied forms. A. simplex, D’ Orb., belongs to the Chalk Marl and Gault. Among English authors, J. Sowerby first described it as 4. Parkinsoni; Forbes, in 1845, vol. i. Quart. Journ., recognized its similarity with R. Robinaldina, D’Orb.; Fitton in the Quart. Journ. vol. iii. gives it an extended range, Lower Perna Beds to top of Cracker Group, bed No. 9; and Mantell, in the Geology of the Isle of Wight, 1847, figured this shell under the last adopted name. It has frequently been included in lists of fossils since, and Mr. R. Tate described it in the paper several times previously referred to. Disiribution.— Abundant in the Lower Greensand of Atherfield, Peasemarsh, etc. Pictet and Campiche name it as occurring in the Lower Aptien of Ste.-Croix, Perte-du- Aare and Vassy. They have named it A. Forbesi. Avorruais GLABRA, Forbes. The following description is partly taken from Forbes’s paper in the Quart. Journ. of the Geol. Soc. for 1845, p. 350, pl. iv. f. 5. Whorls of spire convex and finely striated spirally, the striz near the suture being so deep as to give them a marginated aspect, and crossed by oblong slender ribs, which are not very numerous. The J. Starkie Gardner—On the Gault Aporrhaide. 297 body-whorl is gently rounded and nearly smooth, or with a few spiral strie only, near the suture. The penultimate whorl is also free from transverse ribs. The lip is very large and expanded, pro- duced above into a long linear spur. In front the lip has two other diverging spurs of a lanceolate form. The canal is long, and very slender. Length 24, breadth 14 inches. The specimen described by Edward Forbes is from the Atherfield Clay, and the spire has quite perished, but the form of the wing is still perfectly distinct. Other specimens, in the Geol. Soc. Museum, from the Cracker rocks, are very distinct, and show very delicate strie all over the upper whorls. Fitton in the Quart. Journ. vol. ii. gives it an extended range at Atherfield in the Cracker group, viz. beds 5 and da, 6 and 9. Aporruais Durinrana, D’Orb. Pl. VII. Fig. 13. Description —Shell elongated, composed of angulated whorls ; the angles or keels of each are situated considerably posterior to the middle of the whorl, and are ornamented by a row of large and strongly marked tubercles on the convexity. On the last whorl there is a salient keel, together with two others less pronounced, anterior to it; these three keels appear to preserve faint traces of the tubercles. The pterygoid expansion of the outer lip is not preserved in the only specimen I have examined, but Pictet and Campiche describe it thus,—“The wing is large; the principal carina is pro- longed in a recurved point: there is a sort of webbing or ‘ palmure’ between this point and the spire, the wing forming an expansion attached to the first whorls. In front of the keels the two other ribs form digitations but little marked, and which we only imperfectly know. The mouth is narrow and very incrusted, its lip being thickened. All the shell is covered with longitudinal striz, of which one is alternately larger than the other.” The shell seems strongly to have resembled A. pes-pelicani, especially in the attachment and . thickening of the lip. History.—Named Rk. Dupiniana by D’Orbigny in the Pal. Fr. Terr. Crét. vol. ii. p. 281, pl. 206, f. 1-3, and Chenopus Dupiniana in the Prodrome. After being mentioned by various authors, it was re- described and figured by Pictet and Campiche in the Terr. Crét. de Ste.-Croix, p. 589, pl. xcii. f. 1-3. Distribution—Found in the Lower Greensand of Sandown, and in both the Aptien and Neocomian beds of France and Switzerland. EXPLANATION OF PLATE VII. Fie. 1.—Aporrhais Parkinsoni, var. Cunningtoni, Gardner. From a specimen lately purchased from Mr. Cunnington, by the British Museum, Devizes. Fic. 2.—A. Macrostoma, Sowerby. From the original specimen, now in the Bristol Museum, Blackdown. Fig. 3.—A. Moreausiana, D’Orb. Atherfield. Fic. 4.—A. Fittoni, Forbes. This and the preceding are in the Brit. Museum. Fic. 5.—A. histochila, Gardner. Drawn from a specimen in the Geol. Museum, Jermyn Street. From Devizes. Fie. 6.—A. histochila, Gardner. From a cast, Cambridge. Fig. 7.—A. oligochila, Gardner. From a specimen in author’s cabinet. Grey Chalk. 298 J. W. Judd—On Volcanos. Fie. 8.—A. pachysoma, Gardner. From a specimen in author’s cabinet. Grey Chalk. Fie. 9.— F ene Reed } or description see next Number. Fie. 11.—A. Robinaldina (?), D’Orb. From a specimen in the author’s cabinet. Atherfield. Fie. 12.—A. Robinaldina (?), D’Orb. From an unusually developed specimen in the Geol. Museum, Jermyn Street. Fie. 18.—d4. Dupiniana, D’Orb. From a specimen in the Geol. Museum, Jermyn Street. Sandown. (To be concluded in our next Number.) IiI.—Conrrisutions 10 THE StupY oF VoucAnos.! By J. W. Jupp, F.G.S. Tur Ponza ISLANDS. F the line passing through those three grand centres of volcanic _ action—Vultur, Vesuvius, and Epomeo—be produced to the west- ward, it will strike the very interesting igneous masses of the Ponza Islands. These insignificant islands, which, from the early Roman times down to the present day, have figured in history only as places of banishment for criminals, possess for the geologist the very highest interest. This is due not only to the wonderful characters of the rock-masses which compose them, but also to the admirable manner in which these are exposed to our study by the extreme denudation to which they have been subjected. In 1785 Sir William Hamilton visited these islands, and, being greatly struck by the remarkable features which they present, not only gave a short account of them in the “ Philosophical Trans- actions,” but wrote to Dolomieu, calling his attention to the im- portance of making a fuller examination of them. The illustrious French philosopher spent some time in them during the following year, and as the result of his studies his “Mémoire sur les Iles Ponces”’ was published in 1788. In the year 1822 Mr. Poulett Scrope made that careful survey of the whole of the islands, which enabled him to lay before the Geological Society in 1827 his well- known memoir upon them,” in which so many points of the highest interest in connexion with the characters of the igneous rocks are for the first time discussed. Lastly, in those very valuable investi- gations concerning the microscopic structure of rocks and minerals, which laid the foundation ofa new and important branch of geological science, Mr. Sorby in 1858 largely employed the very remarkable rocks of Ponza, which the researches of Dolomieu and Scrope had. shown to present such interesting characters. After the detailed description of the Ponza Islands, accompanied by elaborate maps and sections, contained in Mr. Scrope’s paper, the accuracy of which I have had the opportunity of verifying, anything like a general memoir upon them would at the present time be quite unnecessary. There are, however, certain features presented by the rock-masses of Ponza which appear to throw important light upon some of the at present “ open questions” of geology. ‘These it may be desirable to call attention to in the present sketch. 1 Continued from page 257. * Geol. Trans, ser. il. vol. i. J. W. Judd—On Volcanos. 999 “The Ponza Islands, which lie off the entrance to the Gulf of Gaeta, form two small groups of islets and rocks, which are evi- dently the highest points of submerged tracts of considerable size— for round the islands the depth of water increases very gradually, and the 200-fathom line is only reached at distances of about three miles from the shores; yet the part of the Mediterranean immediately around them affords soundings up to 700 fathoms or more, as in the case of the Lipari Islands. About thirty miles west ef Ischia rise the islands of Ventotiene and San Stefano. These are evidently two fragments, which have escaped denudation, of a great volcano composed of materials precisely similar in character to those forming the island of Ischia—namely, ordinary trachytes with the agglomerates and tuffs derived from them. The foundations of both the islands consist of masses of rock of great hardness and solidity, evidently, as shown by their highly scoriaceous upper surfaces, portions of vast lava-streams; and these are covered by thick masses of more or less stratified tuffs and agglomerates. Ventotiene is one mile and a half long, by half a mile broad, and it rises to a height of 470 feet above the sea-level. The form assumed by this island, on account of the inclined position of its masses of lava and tuffs, is familiar to all geologists from the sketch given in Mr. Scrope’s “ Volcanos,” page 209. San Stefano is similar in character, but of smaller size, being less than half a mile in diameter, and rising to a height of only 272 feet above the sea; its form is illustrated in the accompanying sketch, Fig. 17. By an elevation of 200 fathoms the sea-bottom around these two islands would be con- verted into an island of conical form, having a diameter of six miles, and a height of nearly 1700 feet. ; Fic. 17.—TuHeE IstAND OF SAN STEPHANO AS SEEN FROM THE SOUTH. a. Trachytic lava-stream, with scoriaceous surface. 4, Stratified.tuffs. c, Prison and Barracks. The same remark applies to the Botte Rock, between Ventotiene and Ponza, a projecting point of another, but much smaller, sub- merged mountain mass. It is composed of ordinary trachyte; and if elevation to the extent of 200 fathoms were to take place, a conical mountain of about two miles in diameter, and having the Botte Rock as its apex, would be exposed to view. 300 J. W. Judd—On Volcanos. Twenty miles W.N.W. of the first of these old submerged volcanic cones is situated the other and principal group of the Ponza Islands, con- sisting of Ponza, Palmarola,and Zannone, with many smaller islets and rocks. The highest part of this group of islands, which are evidently the more prominent points of another submerged tract, is the mountain mass forming the southern part of the island of Ponza, and known as the Monte della Guardia, which rises to the height of 951 feet. This consists of a bulky bed of ordinary trachytic lava, resting upon strati- fied tuffs, both precisely similar in character to those of Ventotiene and Ischia. The form assumed by this mass of lavas and tuffs clearly indicates that it is the sole remaining fragment of another volcano, composed of the same materials as those to the eastward. (See Fig. 18.) Fic. 18.—TuHe HEADLAND MONTE DELLA GUARDIA IN PONZA. a, Columnar trachyte. 4, Stratified tuffs. c, Pumiceous agglomerates. d, Intrusive masses of Quartz-trachyte. In the case of the island of Ponza, however, this relic of an old volcano is seen to rest unconformably upon a still older series of rocks, which constitutes by far the larger portion of the entire group of the Ponzas. These rocks, although evidently of igneous origin, like those which rest upon them, nevertheless offer, alike in their chemical and mineralogical. constitution and in_ their geological relations, a most remarkable contrast to the latter. While the overlying, and evidently newer, rocks are composed of ordinary sanidine-trachytes, with interbedded stratified tuffs, clearly the re- sult of volcanic action at the surface, the latter are made up of highly siliceous pumiceous agglomerates, through the midst of which dyke- like masses of a rock of the same composition as granite, and approaching that rock in many of its characters, has been forced. (See Fig. 19.) ; The remarkable features assumed by these older rocks of Ponza, as the result of the mechanical strains to which they have been sub- jected during their consolidation and crystallization, powerfully arrested, as we have seen, the attention of those pioneers in the study of Vuleanology, Hamilton, Dolomieu, and Scrope; and these rocks are still worthy of the most diligent and attentive study, both as regards their physical relations and their minute structure, by all J. W. Judd—On Volcanos. 301 who desire to investigate the nature, mode of action, and products of SOR S\N — SAELDN - ~ = =-\ / ES <\ (Ge LESS AAA EES Fic. 19.—WESTERN SpPuR OF MONTE DELLA GUARDIA, AS SEEN FROM THE NORTH SIDE or Luna Bay. a, Trachytic lava. 4, Stratified tuffs. c, Intrusive masses of quartz-trachyte with their edges passing into obsidian porphyry. @, Pumiceous agglomerates. The great masses of pumiceous agglomerates, traversed by dykes and sheets of the peculiar quartz-trachyte which together constitute the greater part of Ponza, and the whole of Palmarola, are in Zan- none seen in contact with sedimentary rocks of Cretaceous age (Hippurite limestones) resembling those of the nearest point of the mainland, Monte Circello. To the student of the older volcanic rocks those features of local metamorphism presented by the lime- stones of Zannone, which were first pointed out by Mr. Scrope in - 1827, cannot fail to be of the highest interest. On the north-east side of the island the Cretaceous limestones exhibit precisely the same characters as at Monte Circello; butas we approach the igneous masses extruded through them, they are found becoming highly crystalline and by degrees passing into a dolomite. A specimen of this altered rock, which my friend Professor Guiscardi, of the Naples University, examined for me, was found to exhibit little or no effer- vescence upon the application of acid to it; but when powdered and heated with the acid, carbonic acid gas was at once disengaged. But not only has the limestone undergone considerable changes near its junction with the igneous rocks, but these latter have also themselves been greatly affected, passing into a compact highly siliceous material, with a strikingly conchoidal fracture. It is inte- resting to notice that the intrusive rocks of similar composition in the Hebrides have undergone precisely similar changes near their contact with stratified masses. We have thus evidence that in the Ponza Islands great eruptions of igneous rocks of the most highly acid class have taken place subsequently to the deposition of the Cretaceous rocks, and that after these earlier volcanic masses had suffered greatly from denudation, which appears to have removed all the cones and lava-streams, leaving only masses of agglomerates traversed by dykes and sheets intruded among them, a second series of volcanic outbursts took 302 J. W. Judd—On Volcanos. place. As the result of these latter, at least three volcanic cones, composed of similar materials to those of Epomeo and the older por- tion of Vesuvius and Somma, were formed—namely, those of which we see the relics in Ventotiene and San Stefano, in the Botte Rock, and in the Monte della Guardia of Ponza, respectively. The volcanic tuffs (whether of the older or younger volcanic series in the Ponza Islands) have as yet yielded no organic remains ; so that some doubt still remains, both as to the conditions under which they were formed, and their exact geological age. The newer trachytic lavas and stratified tuffs are not improbably of the same age as the rocks of identical composition constituting Hpomeo and the nucleus of Vesuvius; the older series of rocks of highly acid composition belong to some period between the Cretaceous and the Pliocene. It is on account of the peculiar and very interesting characters presented by these highly acid or siliceous rocks that the Ponza Islands have attracted so much attention from geologists. The ultimate chemical composition of these rocks is exhibited in the three subjoined analyses, for which we are indebted to Abich. They illustrate three of the most important modifications of character assumed by the rock. iL Il. Il. SHUN, Googscosoeoceacca6a50 73°46 eeeees T4534 eaeee 75:09 AlUMING..........0000e0es TBO ——— g6d500 NSPH— Gaane0 13°26 Oxide of Iron ......... 1:49 see te (Ae ols eosiees 1°10 Oxide of Manganese... trace. ...... OBO eee. = NTH) 535 aobsaasoonadeds00 0°45 nd5000 0°34 gee 0-18 TNIEVRINESSIEY Gooscnoode0000 053.9 Siete 3 O24) 2 eesiees 0-16 JROWERIY — sSooc5anq0000ca500 dP) Bodod0 3°68 qcaes6 8°31 DOAN esencscceseeawcecses PAS Gooado 4°86 o0ddon 1:67 IL@S Goaadodooacqn02000000 = 5000000 VP20) goo008 = St Geando ORT. cocto ° PU tf Specific Gravity ........ 2°5398 = PPPS) ac acc 26115 J. is a porphyritic rock with crystals of mica and glassy felspar from Ponza; it represents the more granitic forms of the rock. II. is the interesting, curiously laminated, rock of Palmarola, “the banded and ribboned trachyte” of Mr. Scrope; it contains only traces of mica and hornblende. Abich regards these two rocks as made up of about 50 per cent. of orthoclase, 25 per cent. of free quartz, and 25 per cent. of albite. The small proportion of lime and the large per-centage of soda make it extremely probable that albite is a very important constituent of this rock. III. is a more porous rock from Zannone inclining to the vitreous structure, in which nearly the whole of the felspar appears to be orthoclase, while the free quartz amounts to 28-4 per cent. The microscopic study of these rocks of Ponza brings to light many features of the highest interest. A series of specimens may easily be collected, exhibiting every variation from a vitreous rock to one of the most highly crystalline character ; some of the examples of the latter, indeed, approach so closely in character to granite that J. W. Judd—On Volcanos. 303 it is questionable whether they ought not really to be assigned to that class of rocks. Every attempt, like that of Gustav Rose, to give granite a purely mineralogical definition, has failed, in consequence of the variation, even in different parts of the same mass, in its constituent minerals. The several felspars may replace one another in an almost infinite number of ways, and different micas and hornblendes may be simi- larly substituted for one another, while accessory minerals may so increase in abundance as to become important constituents of the rock, without its in any way forfeiting the title to be considered a true granite. The textwre of the rock, however, appears to afford surer ground on which we may base a definition, than the exact species of minerals which compose it. Normal granites consist of an ageregate, in which distinct crystals of orthoclase, and often of some plagioclastic felspar, with those of one or more species of mica or hornblende, have separated, leaving a base composed of quartz, ex- hibiting a greater or less tendency to form distinct crystals, and a crystalline mass of felsitic matter enveloping the perfect and im- perfect crystals, and representing the “ mother liquor” out of which these latter have been formed, portions of which are also entangled in their cavities. There are, however, granites in which the quartz appears to have more readily crystallized, and to have been among the first minerals separated from the mass. Now the remarkable rock of the Ponza Islands has an ultimate chemical composition identical with that of many granites ; its con- stituent minerals—orthoclase albite or oligoclase, quartz and mica or hornblende —are precisely those of ordinary granite; and hence it must be by its texture, if at all, that we must hope to be able to separate it from that class of rocks. The study of this Ponza rock clearly proves that the minerals of which it is composed have had four different modes of origin. I. They may have crystallized out from a liquefied magma, prob- ably under great pressure, and long before it reached the surface. This is, I believe, the origin of the large crystals of mica, hornblende, felspar, and the smaller and less perfect ones of quartz, which are found scattered, often in great abundance, alike through the most vitreous and the most stony varieties of the rock. In proof of this fact of the formation of large crystals in the magma before its eruption I may cite the following facts. 1. In the masses of volcanic sand blown from the throats of vol- canos, crystals (usually of course broken and damaged, but of pre- cisely similar character to those embedded in the lava) abundantly . occur. The perfect augite crystals ejected by Stromboli afford an interesting illustration of this fact. 2. Where the lava contains these large porphyritically embedded crystals, the scoriz or pumice formed from it will be found to contain the same crystals in a perfect condition, entangled in the meshes of the distended rock ; clearly proving that these crystals were floating in the liquefied mass before its ejection. This fact is exemplified in many of the pumices and scoriee of Ischia. 304 J. W. Judd—On Volcanos. 3. These crystals, when embedded in the rock, are often seen to be rounded on their edges and to have suffered other injuries. Some- times the same crystal is seen broken into several fragments, which are more or less separated from one another. The mica crystals, owing to their perfect cleavage, have often especially suffered; their edges are “‘frayed-out,” their laminze separated by portions of the matrix which has been forced between them, and occasionally the plates of which they are built up are found to be twisted and crumpled in the most extraordinary manner. 4. Such crystals are all seen to be arranged with their longer axes in the direction of the flow, and around them the smaller crystals, formed by the devitrification of the enveloping mass, exhibit the fluidal. structure and a peculiar packing or condensation around and behind them. Many of the sections indeed present an appearance which may be justly compared to the surface of a flowing stream, on which at the same time quantities of chaff and a number of pieces of wood are floating; the former representing the microliths, and the latter the porphyritically embedded crystals. That those conditions of high temperature, great pressure, and the presence of large quantities of imprisoned water and gases, which exist deep down in a volcano, are eminently favourable for the formation of large crystals of various minerals, we have the clearest proof in the beautiful contents of those blocks which are torn from the deep underlying rocks of Vesuvius and ejected from its throat. That the same conditions should induce a similar separation of the materials of the liquefied mass itself, is no more than might be expected. On a future occasion I shall discuss the nature and origin of the condition of fluidity in igneous rocks, upon which so much light is thrown by the fact that crystals of minerals of very different degrees of fusibility are able, not only to separate, but to continue floating about in them. II. When, as was shown by Mr. Sorby, a granite, like that of Mount Sorrel, is fused, it passes on cooling into a glass. But if the cooling be conducted slowly, spherulites composed of acicular crystals in radial groups are formed in the mass. Now in some cases the matrix surrounding the crystals of the Ponza rock before described has assumed a vitreous condition, and it there becomes a porphyritic obsidian. In this obsidian every variation from the first ap- pearance of crystalline structure to the formation of the most distinct spherulites may often be observed. Kil. If glass be heated to a point far short of that required for its - fusion and slowly cooled, crystals of various minerals begin to make their appearance in the mass, which gradually passes into stone, or in other words becomes devitrified. The possibility of this passage from the glassy to the stony condition without fusion is a condition which must always be borne in mind by the geologist. The slow- ness with which large masses of such imperfectly conducting ma- terials, as most lavas are, cool down, is familiar to all who have studied volcanos. It can hardly fail to happen, then, that many lavas which have solidified as glasses have, in the long intervals, J. W. Judd—On Volcanos. 305 during which they have been gradually parting with their remaining heat, become devitrified. The glassy condition of rocks is clearly an exceptional and unstable condition for them to assume. The probable reason why no vitreous | rocks of ancient date exist is not because similar conditions of volcanic action did not prevail in earlier periods of the world’s his- tory, but because the vitreous rocks have lost their peculiar charac- ters by devitrification. In proof of this conclusion I may recal the fact, already described by me, of Old Red Sandstone lavas in Scot- land exhibiting traces of spheerulitic structure, which appears to be in all cases connected with the existence of volcanic glass. Hven a moderate degree of heat, if sufficiently prolonged, permits of the passage of a matter from the unstable colloid to the stable crystalline condition ; and it is not improbable that pressure and other forces long sustained may be attended with the same result. The Ponza rock often exhibits clear evidence that after solidifying in the form of a glass it has been subjected to devitrification. TV. The passage through the rock of water, especially when this contains such acids as abound in volcanic regions, may completely alter the composition and internal characters of the rock. Certain minerals among its constituents may be attacked and removed in solution, while others assume a totally different crystalline condition and arrangement. Of such changes the rock of Ponza often exhibits the clearest evidence, its more basic materials being attacked and destroyed, and its quartz re-crystallized. As shown by Mr. Scrope, veins of quartz and true metallic lodes with cupriferous pyrites occur in this rock ; and the quartz of these, as pointed out by Mr. Sorby, is quite different in character from that in the unaltered igneous rock. It contains ‘‘many fluid-cavities with water holding in solution the chlorides of potassium and sodium, the sulphates of potash, soda and lime, and free hydrochloric acid.” Let us now proceed to inquire what are the relations of this interesting rock of Ponza to granite, on the one hand, and to the ordinary highly siliceous lavas (quartz-trachytes or Liparites), on the other. The geological relations of this rock have been so fully illustrated by Mr. Scrope that it is not necessary to dwell at any length upon the subject. Through vast masses of pumiceous agglomerates, evi- dently formed by explosive action, the solid rock of which we are speaking has been forced in dykes and sheets, which sometimes have a width of a few inches only, at others of many yards. The crushed and re-consolidated character of portions of the matter at the sides of these dykes, the remarkable banded and ribboned internal structure of the rock itself in many places, and the phenomena witnessed at the planes of contact of the dykes with the masses which they tra- verse. bear witness to the violent force and vast irregular pressures which accompanied their intrusion. In no case does this more ancient rock of Ponza appear to have been extruded as lava, and to have consolidated under ordinary at- mospheric pressure. Hither the pressure-of the superincumbent DECADE II.—YOL., II.—-NO. VII. 20 306 J. W. Judd—On Volcanos. ocean, or possibly that of mountain masses of volcanic materials poured out at the surface and piled above them, has evidently influ- enced their mode of consolidation, and greatly modified their cha- racters. This conclusion is quite in accordance with the microscopical characters presented by the minerals which compose these rocks. The felspar crystals abound with cavities filled with stony matter; while the crystals of quartz, as pointed out by Mr. Sorby, contain fluid-cavities with air-bubbles, and present a most perfect resem- blance to those of the true granitic rocks. The result of Mr. Sorby’s most ingenious researches, however, was to show that while the quartz crystals of the Ponza rock must have been formed under a very considerable pressure (one of possibly not less than 4000 feet of rock), yet that the ordinary granites were produced under a pressure which must have been far greater. Great, indeed, as are the points of resemblance between the rock of Ponza and many granites, both in chemical and mineralogical constitution, and in certain features of their microscopic structure, the real and important points of difference between these two classes of rock must not be lost sight of. These differences consist in the tendency which the basis of the rock constantly shows to assume the vitreous condition, and in the mode of arrangement and injured con- dition of its embedded crystals. In these respects the rock of Ponza approaches and even graduates into the ordinary highly siliceous lavas (Quartz-trachytes, Liparites or Rhyolites), such as those which we have described in the Lipari Islands. Thus we are led to the conclusion that rocks like those of Ponza, and certain others in the Euganean Hills, Hungary, etc., which pre- cisely agree with them in character, form a perfect bond of connexion between the granites on the one hand and the highly siliceous lavas (Liparites) on the other. For rocks of this character Richthofen has suggested the name of “ granitic-rhyolite,” or ‘‘ Nevadite,” and his definition of this rock, which constitutes great mountain masses in the western parts of North America, appears to be entirely applic- able to the rock of Ponza. Whether geologists agree to accept this term or not, the fact remains of the existence of a series of rocks through which we can trace the passage, by the most insensible gradations, from granite to the variety of lava known as Liparite. It has been shown by Delesse, Durocher, and other observers, that a rock of highly crystalline or granitic structure has a much higher specific gravity than the glass formed by its artificial fusion. As both mathematical reasoning and experiment have led Sir William Thomson and his brother to the conclusion that for those bodies which contract in consolidation pressure raises the point of fusion, while for those that expand it lowers it, we might by analogy be justified in inferring that, under great pressure, rocks would be unable to undergo that expansion necessary for their assuming the colloid or vitreous condition. I need not point out how this con- clusion coincides with the observations of the geologist. We have the strongest grounds for inferring that in granite consolidation took J. W. Judd—On Volcanos. 307 place under enormous pressure; and we never find it assuming the vitreous structure. In the rock of Ponza the pressure was evidently far less, and the rock occasionally passes into a more or less glassy form; while in the lavas known as Liparites, where all superin- cumbent pressure is got rid of by their extrusion at the surface, the tendency to pass into the vitreous condition is, as we have seen, extreme. By the study of different portions of igneous masses we are able, therefore, to trace every stage in the transition from the most typical granite to the most perfect glass and pumice. The relation of the glassy portions of the rock of Ponza to the ordinary crystalline varieties are, as pointed out by Mr. Scrope, worthy of the most careful study. In almost every case the dykes or intrusive sheets of crystalline rock are at their planes of junction converted for a greater or less thickness into a glassy material. Three different causes suggest themselves as possibly tending towards this result. (1). The more rapid cooling of the liquefied masses on their outer surfaces. (2). The enormous friction, of which we have the clearest evi- dence, between the intruded matter and the agglomerates through which they were forced. This might operate in two ways: by crushing up the solidifying particles, and rendering them easy of re- fusion ; and by the actual development of additional heat from the friction. The probability of this kind of action having gone on is shown by the fact that not only are the dykes of solid rock con-" verted into glass at their sides, but the masses of agglomerate them- selves, near the lines of junction, also pass into obsidian. (3). The smaller amount of resistance offered by the agglomerates to the expansion, which, as we have seen, takes place in the passage from the crystalline to the colloid state, would favour the production of obsidian on the outer surfaces of the intrusive masses. It may well be conceived how, with the presence of such con- ditions as we have indicated, the most remarkable transitions of rock structure from the glassy to the crystalline may be produced; accompanied by the development of the most singular examples of brecciated, ribboned, and contorted appearances. There are a number of other interesting features which have been already described as being exhibited by the Ponza rocks, to which want of space will prevent us from doing more than making the barest allusion in this sketch. Such are the interesting prismatic forms assumed by them on the smallest as well as on the largest scale ; the remarkable globiform concretions in some of their vitreous masses; the changes undergone by them in consequence of the passage of water and acid gases through them; and the formation of crusts of carbonate of lime on their surfaces, and of calcareous sandstones in their hollows, through the agency of land-shells. For details on these subjects I must again refer to Mr. Scrope’s memoir. The causes of the production of the banded structure in these rocks I shall have occasion to discuss on a future occasion. In concluding this imperfect sketch of a district, which, among 308 Professors Rupert Jones and W. K. Par ker— those which have been carefully examined by geologists, is almost without a parallel in respect of the features of interest which it affords, I may refer to two points of some novelty which came under my notice. Occasionally, in consequence of the extreme pressure, the obsidian on the sides of the dykes has assumed a most remarkably fibrous structure, such as has not, so far as I am aware, been observed in this rock at any other locality. A second curious fact was one which I was struck with in breaking up some of the great masses of obsidian, namely, that the bright glassy surfaces of fracture only endured for a few seconds after their exposure ; a delicate white film, doubtless due to the exudation of some crystalline matter on their surfaces, being formed upon them actually under the eye of the observer. (To be concluded in cur next Number.) TV.—Ltsts or some Eneuisn Jurassic FoRAMINIFERA. By Professors T. Rupert Jonss, F.R.S., F.G.S., and W. K. Parxer, F.R.S., F.Z.8. HE late Professor John Phillips requested us to draw up, for an Appendix to his new edition of ‘“‘The Geology of Yorkshire,” a generic list of the Foraminifera of the English Oolites. He had him- self, indeed, supplied us with some good material from the clays near Oxford. We have noted the following Foraminiferafrom the Lower Oolite, Oxford and Kimmeridge Clays, and the Portland Limestone, in our collection. The Foraminiferal Fauna here indicated is comparable with that of Switzerland, reviewed at p. 213, Vol. X. Guon, Mac. (May, 1873), though not so rich in Jliole, and wanting some other genera. M. O. Terqueim’s still more richly illustrated memoirs on Oolitic Fora- minifera (Metz, 1867-70), place before the eyes an enormous collec- tion of similar Microzoa;! and the Rev. J. F. Blake’s memoir on the Kimmeridge Clay, lately read before the Geological Society of Lon- don, enumerates numerous forms of the same group.’ 1. Upper Portland Limestone, Ridgeway, Dorset. Lagena globosa. ; Cristellaria rotwlata. Trochammina (combining the characters of 77. gordialis and Tr. incerta ; low- conical, having irregular chambers within annular chambers, sub-translucent). 2. Kimmeridge Clay, Aylesbury. Foraminifera, Cristellaria. Glandulina. Planularia. Nodosaria. Lituola (nautiloid). Dentalina. Vaginulina (V. harpa). Polyzoon :—Lepralia. Marginulina. 3. Kimmeridge Clay, Kimmeridge, Dorset. Lagena (L. globosa, var., simple, oval, Crzstellaria. without neck). Pulvinulina (P. caracolla). Lingulina. Textularia (Plecanium; small, long, Dentalina. rough). Vaginulina (V. harpa). Lituola (straight). Marginulina. Trochammina incerta. 1 See also Annals Nat. Hist. series 4, vol. viii. pp. 868-365. 2 Quart Journ. Geol. Soc. vol. xxxi. p. 222. English Jurassic Foraminifera. 309 4. Ostrea-deltoidea bed, lower part of the Kimmeridge Clay, at the base of Shotover Hill, near Oxford. Dentatina. Hlabellina. Vaginulina(V. harpa and V.levigata). Frondicularia. Marginulina. Lituola (Placopsilina ; attached, creep- Cristellaria. ing, nearly straight). Planularia. Lituola globigeriniformis. 5. Upper Oxford Clay, Oxford. zi Orthocerina(Rhabdogonium; triangular) Créstellaria. Lingulina (some with terminal Nodo- Planiulania. sarian chambers). Filabellina. Dentulina (very delicate and long). Frondicularia. Vaginulina (V. harpa). Lituola (straight, lituate, and nautiloid). Marginulina. 6. Oxford Clay, Ridgeway, Dorset. Marsginulina. Pulvinulina caracolla. Cristellaria. Lituola (nautiloid and lituate). 7. Shelly Clay, Lower Oolite, on the Deeping Road, 14 mile N. of Peterborough. Nodosaria. Verneuzlina. Dentalina. _ Lituola (straight, lituate, and nautiloid). Vaginulina (V.harpaand V. strigilata). Trochammina (Webbina ; creeping, at- Marginulina. tached to a shell). Planularia. Tr. incerta (both sandy and sub-trans- Cristellaria. lucent). Flabellina. Nubecularia (attached, long, monili- Frondicularia. ; form, on shell). Textularia (Plecanium). The specimens in No. 7 were obtained by one of us from shelly tenacious clay between the thin limestones dug for road-metal at a spot called “Style’s Close,” at the north corner of the junction of Dogsthorpe Lane with the Deeping Road, 14 mile north of Peter- borough, just where the figures “83” occur on the Ordnance Map. On the other or west side of the Deeping Road, opposite to Style’s Close, and, like it, within the “ Walton Fields,” is the railway settle- ment called “‘New England.” From a well here, at the depth of 150 feet, a piece of Upper Lias yielded as follows: 8. Upper Lias Clay, from a depth of 150 feet, at New England, near Peterborough. Cristellaria. Pulvinulina (between P. elegans and P. caracolla) ; small and abundant. Lituola scorpiurus (dentaline and neat). Trochammina incerta (Tr. eliptica ; oblong-oval). To illustrate the relative position of the Foraminifera-bearing beds near Peterborough, mentioned above, the subjoined list of the Oolite beds in the neighbourhood of Peterborough, from notes by Mr. J. W. Judd, F.G.8S., will be of service to the collector,’ for doubtless very much more is to be done with the Jurassic Foraminifera. 1. Lower part of the Oxford Clay; very dark blue shales, with shells. Stan- ground, Fletton, and Woodstone brickyards. 1 “The Geology of Peterborough and its Vicinity,” by the late Dr. Henry Porter (8vo., Peterborough, 1861), may be consulted for some useful details as known at. that date. 310 . Kellaways Rock; sandy clay and sandrock ; very shelly in places. Dogs- thorpe brickyard. 3. Cornbrash, 15 feet ; limestone. 4. Great Oolite Clays, 20 feet ; dark-blue and greenish clays, with shelly bands. 5 6 English Jurassic Foraminifera. NS New England brickyard, Orton railway-cutting, and in many wells. - Great Oolite Limestone, 25 feet ; with marly or clayey bands and partings, very shelly. Railway-cuttings at Orton, and in wells. - Upper Estuarine Series, 15 feet ; blue and green clays, with many very shelly bands. In wells. 7. Sands and Clays of the Lower Estuarine Series, and the Northampton Sand or Inferior Oolite, 20 feet ; in deep wells. . 8. Upper Lias Clay, of the usual character ; in the deepest borings. In many parts of the neighbouring Fens may be found the “buttery clay,’ of Pliocene or Sub-recent date, from which one of us long ago obtained and determined many interesting Foraminifera; see Mr. H. B. Brady’s memoir on Estuarine Foraminifera in the Annals Nat. Hist. 4, vi. pp. 305-6. We may add that we have also seen from the Kimmeridge Clay :— LPolymorphina lactea, Trans. Lin. Soc. xxvii. p. 215. —— gibba, Trans. Lin. Soc. xxvii. p. 218. conipressa, Trans. Lin. Soc. xxvii. p. 229. | Bolivina punctata, Phil. Trans. clv. p. 376, Pulvinulina elegans, var., Phil. Trans. clv. p. 390. ee AL SICH, VAT. rans ..clys p39i75 From the Oxford Clay :— Polymorphina compressa, Trans. Lin. Soc. xxvii. p. 229. Lolivina punctata, Phil. Trans. clv. p. 376. Pulvinulina Karsteni, var., Phil. Trans. clv. p. 397- From some clays of the Oolites :— Virgulina Schreibersit, varieties, Phil. Trans. clv. p. 375. — paradoxa, Ann. N. H. 4, xix. p. 299. ; Textularia ( Spiroplecta) annectens, Ann. N. H. 3, xi. 92, 96. From “Speeton Clay” (= ? Kimmeridge Clay) :— Pulvinulina caracolla (large) in both Dr. Bowerbank’s collection (formerly), and ° in the Museum Pract. Geology (Tablet X14). As a general list for the Oolitic Foraminifera of Europe we offer the following :— Lagena. Orbulina. Nodosaria. Globigerina ? Glandulina. Carpenteria ? Dentalina. Spirillina. Lingulina ? Planorbulina. Orthocerina, Pulvinulina, Vaginulina. LVontonina ? Marginulina. Nummulina. Cristelloria. ‘ VpiereD. Trochammina. Flabellina ? Webbina. Frondicularia. fi TE. Polymorphina. SEAT BTICL Pin Saccammina. Bolivina. Lituola. 2 Vireulina. Placopsilina. Textularia. Cornusp we ? Verneuilina. Nube cularia. Sptroplecta. MMO These are nearly all Liassic also; and in the Lias moreover Decade HVAA PLM. Neu- Sevres. Geol. Mag. 1875. Meteoric IRON, FROM Totuca, Mexico. Polished Surface etched with Bromine. | Actual Sixe.| Dr. Walter Flight—History of Meteorites. 311 Orbitolites has been found by Giimbel (see the Grotocrca Macazinz, Vol. X. p. 82). The Foraminiferal faunz of the Rhetic and the Trias, as far as known, are very similar to the Jurassic. See the GnoLocicaL Magaziny, Vol. VII. p. 180. V.—A Cuaprter In THE History or METEORITES. By Watrer Fuieut, D.8c., F.G.S. Of the Department of Mineralogy, British Museum ; Assistant Examiner in Chemistry, University of London. (PLATE IX.) (Continued from page 267.) 1776.—Krasnojarsk, Siberia. (The Pallas Iron.) ' This celebrated siderolite has recently been sawn into two nearly equal parts, and the occasion presented a fitting opportunity for an exhaustive examination of its constituent minerals, more especially of the olivine forming the chief ingredient. It was accordingly undertaken by von Kekscharow, at the desire of the Imperial Academy of Sciences, and his memoir is mainly devoted to a de- scription of the crystallographic characters of the silicate enclosed in the nickel-iron. He finds that the interior presents no new leading features. The olivine, which has a greater number of crystal-faces than Pallas ob- served on it, occurs not only in spherular or drop-like masses bearing numerous faces, but in tolerably well-developed crystals, which, though rounded here and there, exhibit sharp edges, and a consider- able number of forms, some of which have not been observed on terrestrial olivine. The individual crystal has generally a rounded surface, on which the planes lie; and although these are separated from each other by curved areas, their mutual inclination enables the observer to identify them. They are in most instances smooth and lustrous, and allow of the most accurate goniometrical measure- ment being performed. The hest developed faces are: c =o P; d=P mw; ando—4P. Biot? showed half a century since that these rounded masses of olivine exhibit crystalline structure, and possess two optic axes. The first minute investigation of them was conducted by G. Rose.® Rose observed eleven crystal-forms on the Pallas olivine; von Kokscharow has added eight more, making nineteen altogether, which are as follow : 1 N. von Kokscharow. Bull. ? Acad. Imp. Sc. St.-Pétersbourg, 1870, xx., No. 3. Mémoires V Acad. Imp. Sc. St.-Pétersbourg, xv., No.6 Jahrb. Mineralogie, 1870, 778.—E. H. von Baumhauer. Archives Neerlandaises, 1871, vii—G. yon Helmer- sen. Zeitsch. Deutsch. Geol. Gesell. xxv., 347. 2 J. B. Biot. Bull. de la Soc. Philomatique, 1820, 89. 3G. Rose. Pogg. Ann., 1826, iv., 186. 312 Dr. Waiter Flight—History of Meteorites. Rhombie Pyramids. Macrodomes. : ¢ 1p Weiss. Naumann. Box (es 3 Oe) c P ~ v (a: ob: 2c) 1 Po 4 1 = q (2s Ge be) 38 aya een (a: ob: Le) Boo AMIENS) i (Ce aie 29 pe d fe, (ax tobi) ce )a eee co e (a Ds @) P iE Brachydomes. a (a:2@b:1lc) n v 7 y OD ose (ER AlDe CIO) co GIP eo Sf (G8 Sl 8G) 2 P2 v 04 hb, a0 (@3 1D) 8 eae: )) Po Boi (ES Bi ee lo) GG )) 3 v k (a: $ b: wc) 2P 2 Rhombic Prisms. Gi Wee! (8 se lie ca@) G55 ¢ Pw B woo (E98 18 @)) coo cole Pinacoids. 5 eo (ae Ms Oy) ha oo @ .. (0a: b: 0c) ... oP ieee (Oia ae De)o co 3 Oo (sed We CIO) ay O12 The forms e, f, l, n, s, r, d, k, 7, c, and a, are those described by Rose ; the remainder were not only previously unknown on Pallas olivine, but, with the exception of h and w, have not been met with on chrysolite from any locality. The brachydome w has recently been noticed by vom Rath! on the olivine of the Laachersee sanidine. Although the crystal-faces of the Pallas olivine are somewhat nu- merous, P2, noticed by Descloizeaux,? and oP4, as well as the macropinacoid 6 =o Poo of other observers, have not been noticed. In two of the plates accompanying the memoir the author gives eight projections of the more important combinations of the above forms, while in a third plate they are all graphically represented according to Neumann and Quenstedt’s method. On comparing his measurements of the faces of the Pallas olivine with the numbers obtained by Mohs, von Haidinger, Scacchi,? and himself, when examining crystals of olivine from other sources, the author finds almost complete accordance between them, and deduces the following numbers for the axes of the olivine crystal : a = 1:25928 b = 2:14706 c = 1:00000 He then proceeds to establish their correctness by comparing in detail the calculated values with those obtained by measuring the meteoric olivine, and that from Hgypt and Vesuvius, as well as speci- mens of the mineral from other localities, investigated by Mohs and von Haidinger. Rose * was the first to observe under the microscope the remarkable structure of this olivine. On examining a section, 24 mm. in thick- ness, he noticed, even with very low powers, that it was traversed by a number of straight black lines lying parallel to each other; so 1G. vom Rath. Pogg. Ann., 1868, cxxxyv., 580. 2 A. Descloizeaux. Manuel de Minéralogie, i., 30. 3 A. Scacchi. Pogg. Ann., Ergdnzungsband iii., 184. 4G. Rose. Beschreibung und Eintheilung der Meicoriten, Berlin, 1864, 75. Dr. Walter Flight—HMstory of Meteorites. 313 sharp and regular were they, that they resembled lines described on paper with a drawing pen. When magnified 200 to 300 diameters, they appeared to be tubes, sometimes empty, sometimes filled more or less with a black or light grey substance, or both substances. In one crystal with two small faces 4, and between them the face a, it was noticed that the faces a and the tubes reflect light at the same instant, and that they lie at right angles to the axis of the zone ka. Von Kokscharow found these canals in every granule of the Pallas olivine which he examined ; one crystal, 6 mm. in diameter, through which a section was cut, exhibited 17 of them under a pocket lens, and many more in the microscope; they were all parallel to the edge s7, that is to say, parallel to the vertical crystallographic axis. A mean of nine measurements of the angle which these canals form with the edge ea (which were made with a very good goniometer, designed by von Auerbach and constructed by Hartnack) was found to be 38° 28’, the calculated angle being 38° 27° 12”. The plane of the optic axes lies at right angles to the canals, and therefore to the crystallographic vertical axis ; in short, this plane in Pallas olivine, as in the terrestrial specimens, is parallel to the basal pinacoid ¢ = oP. The canals were studied in seven sections of crystals, and drawings of them are given ina plate. By altering the focus of the micro- scope, canals lying at various depths are brought into view; when a certain thickness of the olivine has been traversed, the doubly- refractive power of the intervening layer of the mineral causes the canals to appear double. Another effect of this property of the erystal is that the magnifying power of the microscope is also apparently somewhat increased. The partial overlapping of the two images of a canal gives it the appearance of a tube filled throughout the entire length with black material ; others, again, viewed through greater thicknesses of the mineral, appear as two distinct tubes. Examination with a Nicol or a tourmaline plate at once convinces the observer that these effects are due to double refraction. The enclosed black and grey matter is found sometimes at one end only of a tube, sometimes in the middle, or again at different points in its length, in which case it presents the appearance of a ther- mometer, the mercurial column of which has been broken. Other sections are described which were prepared so that the tubes were cut obliquely, or at right angles. The results of an examination of these sections in polarized light supports the assumption that these appearances are caused by hollows traversing the olivine, and not by transparent crystals enclosed in it.1 This olivine has been investigated chemically by Howard, Klap- roth, Stromeyer, Walmstedt, and Berzelius. It has recently been 1 Tt should be mentioned that Rose (Beschr. und Einth. Met., 76) found these canals in great perfection and abundance in the olivine of the meteorite found at Brahin, Minsk, Russia (1810), a siderolite bearing the closest resemblance to the Pallas iron. The mineral occurring in the siderolites of Rittersgriin and Steinbach, which Rose termed olivine, and some of the angles of which he found to accord with nee of the olivine of the Pallas and Brahin siderolites, is probably not olivine, but ronzite. 314 Dr. Walter Flight—Mistory of Meteorites. examined by H.I.H. the Grand-Duke Nikolai Maximilianovitsch von Leuchtenberg; the mean numbers resulting from his analyses are given under JI. Von Baumhauer, to whose paper we shall im- mediately turn our consideration, also publishes a new analysis of this silicate (II.), and gives in juxtaposition the theoretical numbers (IIJ.) corresponding to an olivine of the formula: 2 FeO, SiOz + 7 (2 MgO, Si02). I Tale III. SHINOO ABICL \ oroodoonaccounsoc69 AQ DA ee) so AOESGe scat vcce 40700 IWIN, ooso0snaoqde0c0s00000 AJAY jiese lives 46°98) cee cee ATT Tron protoxide ...........+s0. AS OM icourewe aris Mec anctaenleapilis INiekceliprotoxid Mie. -peeseseae ccs eiocenin-srimUTaCe aU ese Manganese protoxide ...... 0:29 .. ... trace JNIBTIAIDDD cey357777200000000000000 0:06 0 AGtA OS20) sa sagssecooad9050000 0 08 99-88 99-91 100 00 Rumler found arsenic in this silicate, and Howard half a per cent. of oxide of nickel. The Duke of Leuchtenberg discovered none of this oxide in the specimens which he examined. It is not improbable that Howard may have fallen into error through the presence of organic matter in the ammonia, employed in his analysis, having rendered the precipitation of the iron oxide incomplete. Von Kokscharow finds the specific gravity of some very pure crystals of the olivine to be 3°3372 ; of some brown fractured granules, 33415 ; the mean being 3°5398. Many terrestrial olivines contain nickel protoxide. Rammelsberg found 2°35 per cent. in the variety of this mineral occurring in the basalt of Petschau, in Bohemia; Genth determined its presence in that from Thjorsalava, of Hekla; and Sartorius von Waltershausen in the olivine of the Fiumara di Mascali, near Etna. It has also been detected in the olivine of Langeac, Haute-Loire; it forms a constituent of that mineral as met with in the lherzolite of the Pyrenees, in the lava of the Isle of Bourbon, in the basalt of Sneefels-Jockul, Iceland, in the melaphyre of Oberstein, and in the dunite of Mt. Dun, New Zealand. A knowledge of these facts in- duced von Baumhauer to examine with great care the Pallas olivine for nickel. That portion of a meteorite which, after the nickel-iron has been removed with a magnet, dissolves in acid, is usually regarded as olivine, 2 RO, SiO,. Small quantities of alumina, lime, manga- nese, and nickel protoxide, and occasionally of alkalies, are, it is true, also found in the solution ; but with the exception of the nickel oxide, the occurrence of which is ascribed to the incomplete removal of the nickel-iron by the magnet, the presence of these ingredients is attri- buted to the incipient decomposition, even in the cold, of the other silicates of the meteorite.!_ Mercury chloride, a reagent the use of which was proposed by Rammelsberg, enables us to separate by solution the nickel-iron from all the silicates. The sublimate, however, does not 1 It has been found that the enstatite of the Busti meteorite (which see) is slowly decomposed by hydrochloric acid, Dr. Walter Flight—History of Meteorites. 315 dissolve any portion of the nickel-iron which by oxidation may have been converted into hydrated oxide of iron and oxide of nickel. To remove them von Baumhauer heats the powder, which has pre- viously been treated with the chloride, in a current of hydrogen, and, after reducing the oxides to the state of metal, subjects the powder once or twice more to the action of the sublimate in an atmosphere of hydrogen. By careful selection and treatment in the above manner, he proceeded to operate on some apparently pure olivine from the Pallas meteorite; it was of a clear yellow colour, and, when heated for half an hour in hydrogen, lost no weight. It was then broken up with acid, and analysed by the usual method ; the iron oxide retaining any nickel oxide that may be present was twice dissolved in acid and thrown down with ammonia. The three filtrates, containing all the magnesia, were treated with ammonium sulphide, which produced a black precipitate, so small in quantity that it could not be weighed. Before the blowpipe it displayed the characteristics of a compound of nickel. Von Baumhauer expresses a doubt whether the nickel may not have been a constituent of a trace of the metallic alloy which, in spite of all precautions, may have adhered to the silicate. It is, moreover, a question whether the repeated precipitation of the iron oxide with ammonia, even in the presence of a large excess of ammonium chloride, would effect the removal of a very small proportion of nickel oxide in so complete a manner as Field’s method with lead oxide.t In May, 1873, von Helmersen addressed a letter to G. Rose, stating that several members of the Academy of Sciences of St. Petersburg, Schmidt, Schrenck, von Kokscharow, himself and others, had advised the Academy to institute an inquiry into the nature of the ground of the locality where the Pallas siderolite was found, they being of the opinion that such an investigation might throw light on its history, just as an examination of the rocks of Disko had proved of great value in facilitating the study of the Ovifak meteorites. Lopatin, a mining engineer stationed in Hastern Siberia, was directed to proceed to Krasnojarsk for that purpose; the result of his explorations has apparently not yet been published. According to Mettich’s report, a very rich iron ore is found on the hill and close to the spot where the Pallas siderolite was discovered. The Mexican Meteorites.? In continuation of his earlier papers on the meteorites of the Mexican Republic, which appeared in 1856, 1857, and 1858, the late Dr. Burkart has brought the history of these remarkable masses down to the date 1874. He first directs attention to the masses 1 F. Field. Chem. News, i. 4. 2 C. Rammelsberg. Zeitsch. Deutsch. Geol. Gesell., 1869, xxi., 83.—J. L. Smith. Amer. Jour. Sc., 1869, xlvii., 383; Amer. Jour. Sc., 1871, i. 335.—S. Meunier. Thése presentée 4 la Faculté des Sciences de Paris, 1869. Recherches sur la com- position et la structure des Météorites, 42 et seq—H. J. Burkart. Jahrb. Mineralogie, 1870, 673; 1871, 851; and 1874, 22. 316 Dr. Walter Flight—fistory of Meteorites. found near Santa Rosa, a small town in the N. part of the State of Cohahuila, in lat. 27° 55’ N. and long. 2° 16’ W. of Mexico, and near the boundary of the Bolson of Mapimi. According to the report of Major EH. W. Hamilton, published by Shepard, the spot where he discovered a number of masses of meteoric iron is calied Bonanza, 30 to 40 miles north, and much further west of Sta. Rosa. Here Hamilton found scattered over an area, one to two miles in diameter, thirteen blocks of iron, twelve of which had never been shifted; the other, weighing 75 lbs., was about to be sent to Sta. Rosa. The largest, a more or less rounded block, is three feet wide and two to two and a half feet high; others were estimated to weigh from two to three thousand pounds. Meteoric masses found in the neighbourhood of Sta. Rosa are mentioned by J. L. Smith, and a fragment of one of them was exhibited at the meeting of the American Association for the Advance- — ment of Science held at Chicago in 1868. It appears that Dr. Butcher obtained from the son of Dr. Long, who had resided many years in Sta. Rosa, an interesting account of a very brilliant meteor which in the fall of the year 1837 passed over the town in a N.W. direction; shortly after its disappearance over the mountains a rumbling sound was heard, followed by a tremendous explosion. The next day Mr. Long endeavoured to find traces of the meteorite, but after two days’ severe and rough riding the search was abandoned. Shortly after- wards an Indian brought into Sta. Rosa a piece of what he believed to be silver, weighing ten to twelve pounds, stating that it had been found ninety miles N.W. of the town; this proved to be meteoric iron. Dr. Butcher, after this long lapse of time, determined to renew the search, and, hiring eight Mexicans and two Indians as guides, suc- ceeded in finding the irons about ninety miles from Sta. Rosa. They consist of six masses, weighing 290, 430, 438, 550, 580, and 654 lbs., which have been sent to the museums of the United States, and two other blocks, weighing 353 and 450 lbs., which have since been hit upon. This interesting group of meteoric irons consists of compact %netal containing no silicate; it is not difficult to cut with the saw, has the specific gravity 7-692, and the composition : Tron = 92:95; Nickel = 6°62; Cobalt = 0°48; Phosphorus = 0-02; Copper = trace. Total = 100-07. Although these irons differ as regards the amount of tinea they contain from the meteoric iron of Santa Rosa described in 1856," J. L. Smith believes that the disparity arises from an error in the earlier analysis, and that it will be found that the Santa Rosa iron belongs to the above group. The question which next arises is,—Are the two finds, described by Hamilton and Butcher, one and the same? Burkart, after care- fully weighing the evidence of both accounts, allowed that there is much to favour the assumption, and suggested that Shepard and J. L. Smith would do good service to science by referring the subject to the consideration of the two observers. 1 QO. Buchner. Die Meteoriten. Leipzig, 1863. Page 192. Dr, Walter Flight—Listory of Meteorites. 317 J. Guillemin Tarayre’ in his Notes archéologiques et éthno- graphiques, while describing the Casas grandes de Chihuahua or Malintzin, mentions the discovery by Miller, the Director of the Mint at Chihuahua, of a meteorite in the great temple north of Galeana (lat. 30° 22’ N.; long. 110° W. of Paris). While ex- cavating these labyrinthine ruins a lenticular piece of iron, 50 cm. in diameter, was discovered carefully enveloped in cloth similar to that in which the dead of the surrounding graves were wrapped. Among new meteoric stones found in Mexico must be mentioned the chondritic meteorite described by Wohler; it is stated that it fell in 1855 or 1856 at the Hacienda Avilez, not far from the mining town of Cuencamé, twenty leagues N.E. of Durango in lat. 24°47’ N. and long. 4° 8’ W. of Mexico. The large meteoric iron, computed to weigh 19,000 kilog., which lay in the neighbourhood of Durango in Humboldt’s time, and of which he brought fragments to Europe that were analyzed by Vauquelin and Klaproth, appears since then to have been lost. Burkart, however, considered some statements made by Guillemin Tarayre in the Archives de la Commission scientifique du Mexique to indicate that within the last few years it had again been found near the Cerro Mercado. According to more recent accounts, the locality of this colossal mass is known, but is kept secret, as the owner intends to endeavour to transport it to Mexico. Burkart briefly notices: the meteoric iron from San Francisco del Mezquital, in the State of Durango, weighing seven kilog., which was described by Daubrée ; a piece of meteoric iron” ‘‘from Mexico,” the locality not being more definitely given, which J. L. Smith found to exhibit very distinct figures when etched, and to be composed thus : Tron = 91:103; Nickel = 7-557; Cobalt = 0°763; Phosphorus = 0:020; with traces of Copper and Sulphur. Total = 99-443. a meteoric iron at Los Zapotes, four leagues from Cuquio, which is reported to have been brought from Zacatecas; and the meteoric iron of Yanhuitlan (lat. 17° 35’ N.; long. 1° 45’ W. of Mexico), which was in the possession of the Emperor Maximilian, and possibly comes from the same locality as the Misteca Alta iron preserved in some collections. ‘The last two masses contain : Yanhuitlan. Misteca Alta. ie : INielelicie celta OP len corer 43 Ob eigen 2 Q-Oi19 Cob altigeveniecs = ccc Or2lnreeera cok OnltSime secre kOs OD Insoluble residue ... trace ... ... 0:20 The first two analyses are by Rammelsberg, the last by Bergemann.? 1 Archives de la Commission scientifique du Mexique. Paris, 1869. iii. 348. 2 This was probably a fragment of the Charcas meteoric iron which General Bazaine sent to Paris. > Burkart gives the following list of localities of meteorites found in the Mexican Republic :—WMeteorie Stones. 1). Hacienda de Bocas, N. of San Louis Potosi, fell 1804, November 24th. 2). Cerro Cosina, near Dolores Hidalgo, District of San Miguel in the State Guanajuato, fell 1844, January —, 11 a.m. 38). Hacienda Avilez, near Cuencamé in the State Durango, fell 1855 or 1856.—WMeteoric Trons (each locality lies to the north of those following it in the list). 1). The Casas grandes de Malintzin, between Galeana and Corralites, District Bravos, State of 318 = Dr. Walter Flight—History of Meteorites. The last paper written by the late Dr. Burkart gives the history of the meteoric iron from Descubridora, Poblazon, near Catorze, State San Louis Potosi, to which we have already alluded (see page 218). It was found between 1780 and 1783; in 1856 it was conveyed to the Amalgamation Works near Catorze to be used in the morteros or stamping mills; and in 1871 was removed to Mexico, where it came into the possession of the Geographical and Statistical Society. In 1872 this learned body came to a determination that the meteorite, which weighs 575 kilog., should be broken up for examination, which drew from the Mexican Natural History Society an indignant protest. ‘Those who take an interest in the correspondence which passed between the two Societies will find below references to the journals in which it appeared.!’ A portion of this iron is one of the most recent additions to the University Collection at Gottingen. The iron, of which the author gives three drawings, is in the form of a prism with rounded ends, and has a length of 90cm. It has a steel-grey colour, takes a high polish, andis remarkably malleable : nails, knife-blades, wire, and a watch spring have been made of it. When etched it developes good figures, of which a sketch is given in Burkart’s paper; they resemble those of the iron of Xiquipilco; the angle 109° corresponding to an octahedron is frequently noticed. Rounded masses of troilite oceur here and there; the hardness is = 8; the specific gravity = 7:38. It has been analyzed by Patricio Mur phy with the following aie Tron = 89°61; Nickel.= 8:05; Cobalt = 1° 94; Sulphur = 0°45; Chromium and Phosphorus — Traces. Total = 99:95. A very careful investigation has been made of the physical pro- perties of the wire forged from this iron; it possesses an unusually high elasticity, the modulus being = 7436-17 kilog. ; the resistance of the iron to rupture by compression = 38 kilog., to rupture by exten- sion = 40 kilog. In each case the sectional area of the metal operated on was 1mm. square. The coefficient of the linear expansion of the iron when heated between 0° and 100° C. = 0:00002386783. Meunier has investigated two of the Mexican irons, those from Charcas and the Toluca Valley. A perfectly clear surface of the Charcas iron appears to be naturally passive. A drop of copper sul- phate, if allowed to evaporate at ordinary temperatures on its surface, Chihuahua. 2). Bonanza, State of Cohahuila. 38). Sierra Blanca, near Huaju- quillo (or Jimenez), State of Chihuahua. 4). San Gregorio, State of Chihuahua. 5). Hacienda Concepcion, on the Rio Florido, State of Chihuahua. 6). Hacienda Venagas, probably in the State of Chihuahua. 7). Plain near el Mercado mountain, N. of Durango, State of Durango. 8). Durango (block used as an anvil; this mass has recently been removed to Mexico). 9). San Francisco del Mezquital, State of Durango. 10). Descubridora, at Poblazon, near Catorze, State of San Louis Potosi. 11). Chareas, State of San Louis Potosi. 12). Zacatecas. 13). A Hacienda south (?) of Zacatecas. 14). Xiquipilco, Hocotitlan, Istlahuaca, etc., in the Toluca or Lerma Valley, State of Mexico. 15). Chalco, Valley of Mexico. 16). Misteca Alta, State of Oaxaca. 17). Yanhuitlan, State of Oaxaca. 18). (?) Rincon de Caparosa, near Chilpancingo, on the road to Acapulco. 1 Boletin de la Sociedad de Geografia y Estadistica de la Republica mexicana. Seg. Ep. Mexico, 1872. Tomo IV. Pages 5 and 317.—La Naturaleza Periodico cientifico de la Sociedad mexicana de Historia natural. Mexico, 1878. Tome II. Pages 277 and 286. Dr. Waiter Flight—History of Meteorites. 319 yields unchanged blue crystals of the salt. The alloy is of the kind to which von Reichenbach gave the name of kamacite, consisting of : Iron = 92:0; Nickel = 7:5; Total = 99:5. which corresponds with the formula Fe,, Ni. The compounds of iron with sulphur which occur in meteorites appear to be sometimes magnetic pyrites, sometimes troilite (iron monosulphide). Meunier finds the sulphides of these two irons to have the composition given below. Side by side with the numbers resulting from his analyses are placed the theoretical percentages of the two sulphides alluded to :— Toluca. Charcas. Troilite (FeS). Pyrrhotite (Fe,S,). IGE --cnoce . o901 ese 56°29 000 63°64 a 60-5 Nickel ...... 0-14 o0c 3°10 S00 500 Copper...... trace wee le 000 obo 6a0 wes Solplmreeeee 10:0 30, meet 9: it ies BOS css, BR 99°18 98-60 100-00 100-00 Sp. ore.eees AN) bla CO oo 47841... 45832 From these results Meunier concludes that the meteoric sulphide has the formula of pyrrhotite—in short that it is not a monosulphide. Tt will be seen, however, in the foregoing table, that though the analy- tical numbers point to this conclusion, the specific gravity of the sulphides accords more closely with that of troilite. Analyses of the sulphide in the meteoric irons of Knoxville, Seeliisge, Sevier Co., and Ovifak (see page 123), show that sulphide in each case to have the composition FeS. The author states that both sulphides are feebly attracted by the magnet. Though magnetic pyrites in fine powder is attracted, troilite (FeS), neither in coarse fragments nor in powder, shows, according to my experience, the least tendency to adhere to the magnet. The crust of the Toluca iron has the following composition :— Tron sesquioxide = 68°93 ; Iron protoxide = 28°12; Nickel protoxide = 2:00; Cobalt protoxide = trace. Total = 99:05. which numbers correspond to the formula Fe, O,, (Fe Ni) O. By treating the Charcas iron with mercury chloride a very small quantity of silicate (?) was obtained, which was not further exam- ined. The particles resembled those obtained from the Caille iron in their action on polarized light. It will be remembered that in the Toluca iron G. Rose found a few grains of what he held to be quartz. Meunier gives the results of an analysis of the meteoric iron found at Xiquipilco in 1784 :— INiekeleiron ays Meee Sea sead - Rend NN Tyee Ete 96-80] Droulitenine ne epee sede dacs Mace, ria! Scliretbersit en tra qees wero wn ecre yt. san 123 Graphite 1:176—100-191 The development of figures on polished surfaces of meteoric iron by exposing them to heat and the action of acids, fused alkalies, or saline solutions, has been studied by Meunier. When the Charcas iron is heated, there are simultaneously developed on different parts of the surface the varied colours exhibited successively on a plate of * Mean of three determinations of the specific gravity of the meteoric sulphide. * Mean of five determinations of the specific gravity of pyrrhotine. 3820 Prof. A. H. Church—Specifie Gravity of Precious Stones. steel by raising it to different temperatures. On examining the altered iron, the author was enabled to detect the -presence of a small amount of the alloy termed plessite. The figures are in their general characters identical with those developed by acid. When a polished plate of the Charcas iron is plunged into a hot solution of copper sulphate, the figures are developed with greater distinctness than when acid is used, the lamelle of tinite appearing red on a white ground. By employing mercury chloride and varying the degree of concentration and temperature of the solution, a metallic surface may be made to present as many as three different phases of crystalline development. With a hot concentrated solution of this salt the Charcas iron exhibits the most beautiful figures. Gold and platinum chloride have also been used by the author, and the former salt is recommended in cases where it is desired to arrive at an im- mediate knowledge of the crystalline structure of an iron. To etch a fine section of Toluca iron, recently acquired by the British Museum, water saturated with bromine was used. The edge of the slab was surrounded with modelling wax; the bro- mine water was then poured on, and in a few seconds removed with blotting paper. The surface was next flooded with distilled water, which was removed as before. Absolute alcohol was then poured over the etched surface, and this again was quickly taken away with bibulous paper. The iron was then preserved face downwards for some days in a dry box filled with burnt lime. Plate IX. gives a representation of a part of the surface of this beautiful slab of metal. The figures will be considered when we come to describe those of the Braunau iron and the crystals of meteoric iron which occur in the Cranbourne meteorite." (To be continued in our next Number.) VI.—Noves on THE Spectric Gravity or Precious STonzs. By Prof. A. H. Cuurcu, M.A. . ROM time to time I have accumulated a large number of results obtained in identifying precious stones by means of their specific gravity. From these results I have selected about 70, which will be found arranged below. The observations have been made with care, and, where no temperature is given, at 16° 5 C.; an asterisk denotes those determinations in which a very accurate assay balance by Oertling was used, and in which the specimens were immersed in alcohol, not in water. In these latter determinations any error would be confined to the third place of decimals. No. Name. Remarks. Spec. Grav. 1. *ApuLARIA ... Moonstone, flawless, Ceylon Wit tl Sn oe ee LO OO 2. Berry ... Brownish yellow, flawless ... ... ... ... ... 2°69 3. ss ... Deep sky-blue, flawless (probably been heated)... 2°701 4 & ... Yellow, became blue after ignition but unchanged inkspec. ora. leit Ui Sei Mi ce ceo) Bee ieteeRmme nO ON 5. 5 ae Fine aquamarine, weighing 5°73 grams ... ... 2°702 1 Kick (Pol. Wotizbl. xxix. 105; Pol.|Jour. cexii. 40) employs for the etching of artificial iron and steel a mixture of one part of hydrochloric acid and one part of water, to which a little antimony chloride has been added. Surfaces etched with this liquid are less hable to rust. Kick states that some irons and steels are quite passive, but that this property may be destroyed by raising them to a rea heat. Prof. A. H. Church—Specifie Gravity of Precious Stones. 821 It will be seen from these determinations that the density of this species (beryl) is remarkably constant. I found very nearly 2°7 for a crystal of emerald of good colour, but the number would doubtless have been rather higher had there been no flaws in the specimen. No. Name. Remarks. Spec. Grav. 6. CHRYSOBERYL. Golden yellow, flawless... acd ad ote eg EE . 5 Brownish yellow, flawless ... ... 206 ese eee 3°734 8. * is Yellowish brown, flawless ... 1. so. so «. Of oes gs Emerald green, slightly flawed ... ... ... ... 3°86 The above numbers serve to show that chrysoberyl may be dis- tinguished from chrysolite by its specific gravity, although the greater hardness of the former species is sufficiently decisive on this point. Jewellers constantly make a confusion between the two stones, especially in small specimens of a yellow hue ; but the follow- ing determination of the specific gravity of a good chrysolite shows this stone to be less dense than the former : 10. Curysonire. Peridot of rich green colour, flawless... ... ... 3°389 11. 4 The same stone as No. 10, afterignition ... ... 3°378 12. *GARNET «+ . Mssonite, nearly flawless - :.¢ (22. .-. soo, «0. oO Odl 13. op sea, SHssOnites flawed we csp (ses ccau eee evel 8 cas, Less) 2 O1004 14. SS Po eLssonite sont Hawsieemescom cece | ere) eso) ieee OiO00 16. 6 ... Hssonite, a fine specimen ... woes eee O04 16. OF ... Dark red, flawed and opaque in parts... Sis aves 14008 if - ... The same stone after heating ... ... ww. .. 4:044 18. * sooelued, tLansparcuul sey ess) earth uses eescmmeeena 41059 19. om 500 The same stone after fusion.. 000; ond -o00 cag, SHINE 20. 5 ..- Clear red ws Saat cadanl Meson eter Tate GOROO BAILS Fei Teas ... Very pale brownish red... wes God oc coo SOLS DD a ... Rather darker than No. 21... ... ..© «se ... 93°696 Nos. 12 to 15 were specimens of the stone usually called by jewel- lers the jacinth. The above determinations are corroborated by a series of specific gravities of this stone communicated to me by Mr. Rudler. The deep red or precious garnet often has a specific gravity close to that of the ruby. Specimens of a fine variety of red garnet have been lately sold for the true ruby ; indeed, one of these garnets, well cut and mounted with diamonds, requires a practised eye for the recognition of its real character. 23. * Quartz. ... Milky, banded, flawless ease tee) cee eee! (L926 49 24. Ee Amber yellow, flawless ae Reo eset eoce CBOE 25. Pale brown, with whitish streaks 560-008 cog | ZOTII 26. bs SMOkyp pale DLO MU evsesc a escu iesel ese; | een ;66 27. i Pure rock crystal... ... es coo coo coe OH 28. o Pale yellowish brown, flawless .. ... cco coo PASS! 29. 3 ANGUS, WAT GEE — Gop esc “G00 Gad. coo eon PLB 30. 3 Amethyst, dark... -. 27608 31. " Amethyst, not so dark as Nos. 29 and 30... ... 2-659 The above numbers seem to show that dene-colonred amethyst is really denser than pure crystal; while the latter, again, is denser than milky quartz. 32. SappuHirE. ... A white crystal, banded with blue ... ... ... 3°979 33. _ Golden yellow, flawless soos GS co cop? coe SEO 34. Pe Yellowish grey, subtranslucent ... ... ... ... 3°94 DECADE II.—vYOL. II.—NO. VII. 21 322 Prof. A. H. Church—Specific Gravity of Precious Stones. I believe the specific gravity of white, yellow, and blue sapphire is rather over 4 when the specimens examined are perfectly free from flaws. No. Name. Remarks. Spec. Grav. 35. SPINEL. ... Indigo coloured, flawless ... ... «. «+. 16° 3°675 36. 34 A similar specimen Boo toe! sooo cde. doo, SU 37. a Puce coloured, flawless... ... ... ... «« «s. 03 Gol 38. * Bp Rose coloured, flawless... S06 cou wooo soa 2 coo SEL Red, pink, and pale spinels are, I have found, rather less dense than the deep blue and greenish blue stones. The specific gravity of this species is very close to that of the hyacinthine garnet. 89. Topaz... .. White, flawless, from Brazil Soe eeSoieeeen | vecn MORO OU 40. a White, flawless Soo Gh Hoo eco tds don, og. eg Ih 41. 5 White, flawless... po ono oo SS) 42. a White, slightly flawed, “from Brazil... 1... 3°564 43. a White, flawless— weight 4:369 Bane eetesem MORON 44, a White, flawless... oo ae con) UES) 46, 55 iWihitesstlawilessia aspire.) b coeuuucnen set lesen ssa ORO, 46. a Wine- ~yellow, flawless ... .. 3 539 47. a The same crystal after ignition “and sites ‘of colour to pink .. 3533 48. op Deep pink, flawless. Had been heated ; weight PASS) EMIMSo55 G59 G00. 0G ww. 3004 49. 55 Pale sky blue, flawless throne ia) eta ayal The very brilliant white topazes Bont Brazil have (so far as my experiments have gone) a slightly higher specific gravity than the stones of less lustre from Flinders Island and other localities. Coloured topazes also, from all localities, appear to be less dense than those without colour. Heating, which changes the yellow colour of a topaz to a rose pink, effects no alteration in its density. 50. * TourMALINE. Green, flawless, from Brazil... ... ... .. 17° 38°154 dl. 6 Grass-oneenyyl aweduy mace snc glass ilessieber TMi euEoEOO 52. op Black, from Bovey Tracy ... ... 0. «. «. 3 124 53. 99 Black, Bovey Tracy 5 con coo ono cog | LF 54, 9 Dull greyish ereen, flawless g00 600 co con, IIS 50. oh Green, very slightly flawed ... ... ... s « 3109 Black tourmalines are occasionally fissalled garnets. 56. ZIRCON. ... Brownish yellow, transparent, flawless ... 4-679 57. 99 Jacinth from Expailly, flawless cies we ig- nition) . 30908 --- 4863 58. % Greenish, from Ceylon, flawless... «- 4579 59. . The same stone (58) after prolonged ignition vee 45625 60. 50 Yellow, flawless ... 200 60° ocd coo | EB 61. * 4 Brownish yellow, flawless iNs dase ieee eeke Voss PASO, 62. ‘ Brown, flawless... .- 4°696 63. 9 Dull dark green, slightly opalescent, flawless... 4-02 64. Ps Hair brown, transparent but flawed, Fredriks- varn ... -. 4489 65. AA The same crystal, after ‘prolonged ignition... we 4633 66. 09 Pale brown, opaque, Green River, Henderson ae North Carolina 900 we 4°64 67. a The same crystal, after prolonged ignition... --. 4667 68. Fy Deep red, flawless, from Mudgee, New South Walesa. pacer 3100) 69. “4 The same stone, after prolonged ignition poo goo | HP 7/ 70. FA Pale green, flawless, from Ceylon wee see wee | 4091 J. G. Goodchild—Glacial Erosion. ole The above numbers call for two remarks. Firstly, it will be seen that though the density of zirecons from some localities is increased by ignition, this is not the case with the Expailly or Mudgee speci- mens, which remain unaltered by heat. Secondly, some zircons are of very low density (No. 63 above). This density remained the same after heating. The stone was a true zircon however, giving on analysis the per-centages of that species. VIJ.—Guacrat Erosion.1 By J. G. Goopeuitp, F.G:S. ; Of H. M. Geological Survey of England and Wales. HE Lower Carboniferous rocks of the Yorkshire Dale District— Wensleydale, Swaledale, Dentdale, Garsdale, and the adjoining parts—consist of a series of alternations of limestones, sandstones, and shales, not usually much inclined from horizontality. The harder beds of these commonly form terraced outcrops, which are often several hundred yards in width from the scar or the steep escarpment at their outer edge to their inner margin where the next bed above comes on. Owing to the nearly horizontal position of the rocks throughout the greater part of the district, many of these ter- races and scars can be followed for miles almost without interruption. Hence they form perhaps the most prominent characteristics of the Dale District scenery, and they offer a striking contrast with the generally regular outline of the dome-shaped hills, and the short and irregular scars that characterize the adjoining area of Silurian rocks. The principal object of the present communication is to endeavour to show how these Carboniferous terraces and scars were formed. Whilst engaged with Professor Hughes upon the Geological Survey of the Dale District I often noticed that the swallow-holes marking the presence of the limestones there occur along only the inner margin of each terraced outcrop, while nearly all the rest of the rock exposed is entirely free from such indications of Subaerial Denudation. Then again, the inner and the outer margin of each rocky shelf are rudely parallel to each other and to the outlines of the terraces both above and below; and where the valley is not very wide, the outline of each scar, whether convex, nearly straight, or concave, is matched by the corresponding form in the scar formed by the same bed on the opposite side of the dale. Not less striking is the frequent absence of any debris from the higher beds on the same hill-side, even from those close above the limestone of the terrace. Hitherto it appears to have been assumed that the long-continued action of subaerial agencies is sufficient to produce the phenomena here referred to; but, however plausible at first sight this theory may seem, when it is applied to explain some of the facts that an attentive examination brings to light, it fails completely. 1 The substance of the following communication was laid before the Geological Society 24th June, 1874, by permission of the Director-General of the Geological: Surveys. It is reproduced in its present form in order that the accompanying theories may evoke some criticism, which they could not receive when the original article, together with 26 others, was read in brief abstract at the last meeting of the Session. 324 J. G. Goodchild—Glacial Erosion. _ Whatever theory is proposed to account for the present form of the rock surface in the Yorkshire Dale District must be based upon not only the various classes of facts that are now almost on all hands admitted to be the work of subaerial agencies, but also upon the following points that do not so easily admit of an explanation :—1. The outerop ef each limestone is. weathered nearly equally all over; and as a rule swallow-holes are found only along its inner margin, although there is occasionally a width of several hundred yards be- tween the inner margin where the swailow-holes are found and the scar that forms the outer edge of the terrace. 2. Between the tribu- tary valleys the scars either extend in nearly straight lines or else sweep in broad convex or concave curves, whose general regularity is only occasionally interrupted by the channel of a small stream from the higher greund. 3. The scars are as often found perfect at elevations of several hundred feet above the bottom of the valley where they occur as are those lower down. In the case of the highest thick limestones of the Yoredale Rocks, known respectively as the Main and Undersett Limestones, the thinness of the intervening beds causes the outcropping sears of the limestones to run in pairs, which often keep the same horizontal distance apart for miles, and thereby render their regularity of form more than usually striking. 4. Where the rocks are much disturbed, the characteristic terraces usually keep to the same bed through all its variations of position and inclination ; so that instances are not wanting in which the same bed forms a terrace rising two hundred, or even four hundred feet within half a mile. 5. Little disintegrated rock from the beds above is commonly found upon the limestone terraces, even where the absence of such debris cannot be accounted for by stream action. 6. And lastly, the terraces and scars developed along the outerep of each limestone are usually even more perfect than those of the less-easily-weathered sandstones that they are associated with. Bearing these points in mind, let us see how far the commonly received theories will apply in the present case. As the terraces here referred to are seldom horizontal for any great distance, and sometimes have a slope of even several degrees, it is obvious that their marine origin is quite out of the question. This theory therefore will be passed without further mention. The other great class of agents at work developing the surface characteristics of each rock is usually designated Subaerial Denuda- tion. Under this term most writers include also the abrading work of ice; but in the present communication Subaerial Denudation will be taken to mean only that kind of alteration of the form of the ground that is effected by the separate or the combined action of the weather and running water; while the term Glacial Erosion will be used for the abrading work of moving ice. For the present we have to deal only with the effects of Subaerial Denudation upon the particular kinds of rock that make up the hills of the Dale District. Of these by far the most important rock is limestone, which is found interstratified with the other rocks in bands whose thicknesses range from a few inches to a hundred feet or more. In character most of J. G. Goodchild— Glacial Erosion. 325 it is of the ordinary Mountain Limestone type—a more or less com- pact, grey rock, occurring in “posts” from a few inches to several feet in thickness. Each bed of limestone is almost invariably over- lain by more or less shale, and nearly as often it lies directly upon sandstone ; so that the order of the beds from the top of the series to the lowest beds seen is, soft shale upon limestone, which, in its turn, lies upon a still harder bed of sandstone. Under the action of the weather each kind of rock behaves differ- ently. Where the outcrop is of shale, and formsa steep bank along- side a stream, the numerous divisional planes help to make the rock go to pieces in a very short time; so that, in such a case, whatever the overlyimg beds may be like, the bank is not long in being cut back. But where the outcrop forms a gentle slope that is out of the way of constantly running water, shale that is not more than usually sandy decomposes into-a tough elay, much of which remains at the surface, and thereby greatly helps to lessen the waste of the beds beneath. Some good examples of the different rate of weathering of the same bed of shale where exposed to the action of running water, and where affected only by weathering. are found about the waterfalls or “fosses” in the Dale District. Under the waterfall the shales are kept in the condition most favourable fer their rapid de- composition, so they are quickly eut back beneath the harder beds that form the edge of the fall. But at the outer end of the ravine that has been caused by the gradual recession of the waterfall, so little has subaerial denudation accomplished, notwithstanding that a rapidly flowing stream is at hand, that the difference between the rate of recession of the fall and that of the sides of the ravine is occasionally as 40 to 8. In other words, while the waterfall is cut- ting back forty feet each cliff it has left recedes: only eighteen inches. The particular instance here referred to is doubtless an extreme case where the beds overlying the shale are more than usually durable ; but it serves to prove that even where there is a rapid stream flowing the denudation of shale does not go on very rapidly unless the stream actually flows close to the outcrop. Where limestone is the rock that overlies the shale, this is usually cut back much faster, because the surface water finds an easy passage through the joints of the harder bed. It will be interesting to compare the figures given above with those obtained in similar instances elsewhere. In all such cases the difference between the width of the outer end of the ravine and the width close to the fall, compared with the distance between the two points thus measured, will give very nearly the ratio between the rate of denudation, on any given rock, by stream action, and that of ordinary weathering. If then, so little denudation of a rock as easily worn as shale has been accomplished in Post-Glacial times by the rapid streams of the Dale District, where these streams are absent we ought to find the rate of denudation so slow as to produce results that are hardly per- ceptible. Accordingly, it is not uncommon to find glacial strie within a few feet below the outcrop of a bed of shale; in which case the horizontal distance between the ice-markings and the base-line of 326 J. G. Goodchild— Glacial Erosion. the shale marks the greatest distance that this can have been cut back in Post-Glacial times. The thinner kinds of sandstone, especially where they are much split up by beds of shale, seem to go to pieces very readily; but upon the more compact, blocky, and little jointed kinds ordinary weathering seems able to produce very little effect. A very good example of this is to be found at Mosedale Foss in Wensleydale— a waterfall caused by the superposition of a hard and blocky sand- stone on a bed of soft and thinly laminated shale. The length of the ravine that the fall is found in is nearly eight hundred feet from its outer end to the fall itself; while the difference in the width of the ravine at the two points measured is only sixty feet. “Yet in this instance a rapid stream flows within a few yards of the foot of the scars, which have thus receded only thirty feet on each side since the ravine was formed. There is good reason for thinking that this was in Post-Glacial times. The remarks made above relative to the nearness of glacial strize to the outerop of higher beds of shale apply equally to the accompanying sandstones in similar positions ; thus we get direct evidence that some of the sandstone scars have not been much altered in form since the close of the Glacial Period. For our present object the rock of most importance as regards its behaviour before subaerial agents is limestone. Not much more need be added to what has been already stated about the cutting back of a waterfall in this rock: where, however, it is found in thick beds, and is not very much split up by structural planes, limestone seems, under like conditions, to recede not quite as fast as sandstone. But under the influence of the weather, limestone, as is well known, often disappears with great rapidity. Jukes’s comparison of it to a glacier melting before the summer’s sun conveys an excellent idea of the way this rock is dissolved and carried away in solution by the waters from the surface. The numereus structural planes that every bed of limestone is more or less divided by are developed and rapidly widened to a considerable depth from the surface by the action of the acidulated waters, which thus easily find their way to a lower level. There seems reason for believing that the absolute rate of dissolution of limestone is far from slow, even when measured by years. In Kirkby Stephen Churchyard there was in 1871 an erect gravestone of ordinary mountain limestone that was put up about fifty years ago. As the stone was carved, at least the greater part of it must once have been smooth and unweathered; when I saw it in 1871 there were encrinite stems and bits of other fossils left in relief to the extent of a tenth of an inch or more, because the softer matrix had been removed by the rain that has fallen on the stone since its erection. One cannot be quite sure even that the highest parts of the fossils accurately represent the original dressed surface; but, assuming that they do so, we have in this instance proof that a smooth and quite unweathered piece of limestone, standing in a position the least favourable for erosion by subaerial agencies, is being dissolved away at the rate of one inch in five hundred years. Where the form of the surface is such that water can remain some time upon the rock, J. G. Goodchild—Glacial Erosion. 3827 all the structural planes near the surface are rapidly widened, by which the removal of the rock is greatly facilitated. It will then readily be admitted by most geologists that under purely atmospheric conditions the rock that tends to disappear the fastest is limestone; next to this shale; and the slowest of all to weather away is sandstone. When subjected to mechanical erosion, as when these rocks are being worn in a river channel, the rates of abrasion are nearly as the relative hardnesses of the three kinds of rock. Shale goes fastest, next to this come the thinner-bedded sandstones, and longest of all in being worn away are the blocky sandstones and the purer kinds of limestone. The last-named rock especially seems able to withstand much of the ordinary wear and tear of even a large stream. In the case of some of the waterfalls, the limestone forming the floor of the ravine is rarely worn down many feet lower at the outer end than it is found beneath the fall. The same remark applies also to many of the harder beds of sandstone. Thus far then it seems clear that the rocks that best withstand mechanical erosion are at the same time those that are least able to withstand Subaerial Denudation. Therefore, if Subaerial Denu- dation has really had so much to do with the development of the existing surface characteristics, we ought to find the more prominent features exclusively of sandstone; while the accompanying limestone, everywhere but near the streams, should be dissolved clean out of sight. But, although there are in the Dale rocks frequent alter- nations of limestones with sandstones and shales, in the majority of cases the more prominent terraces and scars consist solely of limestone. If rivers have been concerned in the formation of the features in question, it is difficult to understand how these have retained their regular form in such perfection while the stream that produced them has cut down several hundred feet into the rocks beneath. It is not easy to believe that a river ever extended right across the dale from the highest scar on one side to the corresponding scar on the other ; yet the advocates of the subaerial theory virtually assume that when the scars were formed the rainfall was so much greater than at present that the river filled the dale from side to side. There can be no better proof of the fallacy of this argument than is afforded by the existence of inclined scars that rise towards the lower end of the valley. A good instance is found near Carperby, in Wensleydale, where a limestone scar and terrace, after a rapid descent of nearly four hundred feet in just half a mile, rises again to the same level within twice that distance, in the direction of the mouth of the valley. Yet in this instance the scar and its accompanying terrace are as perfect at the highest point as at the lowest; and where the bed that forms the scar is faulted, scars of nearly the same character occur at different levels within a few yards of each other on the opposite sides of the dislocation. All such denudation by rivers is limited to the zone between the highest flood-line and the bed of the river—rocks also from points above this are it is true often 328 G. H. Kinahan— Erroneous Names of Drift. undermined and brought down; but a terrace can be formed only within the vertical limits just named. Hence it is clearly im- possible for a river to shape rock into a terrace that is inclined several degrees from the horizontal. Thus far then the objection against the fluvial origin of these rock ledges are: Ist, Many of them are situated a thousand feet above where any stream that could give rise to them could possibly flow. 2nd, The scars on both sides of the valleys often maintain a rude parallelism for long distances ; a convex outline on the one side being opposed to one correspondingly concave on the other, even where the distance across the valley between the two scars exceeds a mile. . Lastly, each bed gives rise to a form of terrace that has some more or less marked peculiarity which appears at whatever inclination that particular bed may be lying at, and at whatever elevation it may occur above the bottom of the valley. (Lo be concluded in our next Number.) VIIJ.—TuHr Erroneous NoMENCLATURE OF THE DRIFT. By G. H. Kinanan, M.R.I.A. IP\HE necessity for areform in the present nomenclature of the Drift is apparent from the different papers on the subject, but more especially from the note appended to Mr. Bird’s supplementary paper on the ‘“ Post-Pliocene Formations of the Isle of Man” (Grou. Mac. May, 1875, p. 228). The author of this paper states that this glacial drift is “generally marine.” May I ask how a drift deposited in the sea can be called glacial? Undoubtedly, originally, it was ice-formed, but so also are all the drifts or the major portion of them, that at the present day are accumulating in the seas round our islands, in our lakes, and in our river valleys ; let them be shingle, gravel, sand, silt, or a boulder drift. A normal glacial drift must be deposited direct from ice. If, however, subsequently it is sorted and re-arranged by water or any other agent, it ceases to be glacial. If any other definition of glacial drift is allowed, in glacial drift may be included shingle, gravel, sand, silt, besides the different boulder-clays, at the caprice of the _ explorer or writer, if he can only prove that subsequent to their being in their present condition, they had been normal glacial drift. At the present day, if the sea, the waters of a lake, a river, or even rain, is denuding glacial drift, a boulder-clay may be forming, identical in aspect, with these so-called “stratified glacial drifts ” ; they evidently are not glacial drifts, yet they are formed by similar secondary arrangements to those drifts that some observers would rank as glacial. In ali hilly ground (such as the Isle of Man), after the ice had retired and the sea occupied its place, the margin of the latter, rivers, etc., formed cliffs in the glacial drift, at the base of which, sands and such-like deposits accumulated ; the latter, in many cases, were subsequently covered up by the weathering from the cliffs, the newer depositions being stratified boulder-clays, but of meteoric origin, and probably formed long after all the ice had left the John Horne—Newer Deposits of the Isle of Man. 329 country. Or the high-lands may have been enveloped in ice, and from the margins thereof, rock detritus may have been dropped into the sea, forming drift accumulations, not, however, normal glacial drift, as the detritus would have been more or less washed and re-arranged by marine action. As to the Irish drift. Over twenty years ago, it was supposed that there were two glacial drifts separated by oravels and sands; but during the subsequent examination of the island under the late J. Beate Jukes, F.R.S., it was proved, that although there are two glacial drifts (boulder-clay drift and boulder or moraine drift), yet between them there are no sands and gravels, the sands and gravels being newer than both, and found indiscriminately on either. Within the last few years, however, on very partial and immature observations, this old theory of the ‘‘ middle gravels” was again started ; but in subsequent papers the unsoundness of the arguments and statements in its favour was demonstrated. If the author of the paper on the “ Post-Pliocene Formation of the Isle of Man” will turn to my letter in the April Number of the Magazrnz, he will find that inadvertently he misquotes it. A glacial drift above the “middle gravels” is what has not been found in Ireland, but an upper glacial drift is well known. IX.—Tue Posr-Puiocens Formations oF THE Is~E or Mav. By Joun Horng, F.G:S. ; Of the Geological Survey of Scotland. N the postscript to his paper on the Post-Pliocene Formations of the Isle of Man, Mr. J. A. Birds takes exception to my classification of the Manx drifts.! He states that, ‘‘a priori, is it not against Mr. Horne’s view of his Lower Boulder-clay being really such that there should be intermediate formations of sand and gravel when the cold was at its extreme, and the ice, according to his showing, from 2000 to 3000 feet thick?” To those who are well acquainted with the appearances presented by interglacial deposits, this objection cannot have any weight. The Lower Boulder-clay or Till of North America, of Sweden, and of Scotland, contains well- marked accumulations of fossiliferous sedimentary matter ; and non- fossiliferous sand and gravel are of common occurrence in the Till of these and other countries. From these and other considerations, it is most probable that the Till or Lower Boulder-clay and its inter- calated beds betoken a succession of cold and warm periods. The appearance of layers of sand and gravel in the Manx Boulder-clay is quite in keeping with the facts referred to. Mr. Birds further notes, “that if all the deposits are assigned to the first glacial period and the great submergence, what memorials are left, beyond some possible moraines, of the second glacial period, or the times next preceding and following it? Surely there ought to be such if the land has not been submerged since.” The author seems to forget that the glaciers of the post-submergence period were confined mainly to the upland valleys. They did not deploy 1 See Grou. Mag. May, 1876, p. 226. 330 John Horne—Newer Deposits of the Isle of Man. far into the low grounds, and therefore no other memorials could have been left, except ‘some possible moraines.” One or two remarks may now be made on the succession advanced by Mr. Birds. He considers the true Lower Boulder-clay to be ~ represented by the shelly clays which occur in the cliff sections in the north part of the island, stretching from Ramsey to the Point of Ayre, and thence to Kirkmichael. Forbes long ago examined these beds, and pointed out that they lie usually at the base of the cliffs, being capped by a great thickness of stratified sands and gravels, on which rest large boulders. Now the difference between these shelly clays and true Lower Boulder-clay is so distinct and obvious that I cannot see how any one who has had experience in mapping drifts can possibly confound them. The clays, which attain a great thick- ness between Sea-view and Port Cranstal, contain few stones. These are no doubt smoothed, and often scratched ; but their occurrence is quite exceptional. Moreover, the clays are often finely laminated, and the position of the stones in some places is such as to lead one to believe that they had been dropped during the accumulation of the thin layers of mud. In short, these marls, so far as I saw, strongly resemble in general appearance the glacial clays of the Forth and Clyde basins, and similar deposits at Dumfries in the Nith basin. It is hardly necessary to point out that ‘such is not the character of true Lower Boulder-clay or Till. This latter deposit is always highly charged with stones, most of which are scratched on every side, the matrix being extremely tough and quite devoid of stratification. But further, these marls, north of Ramsey, contain shells in abundance, which have been named by Forbes; while the true Lower Boulder-clay is unfossiliferous. It is quite true that shells have been obtained from Boulder-clays in different parts of Scotland, Lancashire, and elsewhere; but these are more recent than the Till, though belonging to the pre-subergence period. If further proof were needed to convince Mr. Birds that there is a difference between these shelly clays and true Boulder-clay, reference might be made to a section near Port St. Mary, on the south side of the island. After turning the point south of the lime-kilns, a deposit of stiff stony clay, packed with angular, subangular, and smoothed stones, most of them scratched, is found resting on striated beds of Carboniferous Limestone. This bed, which resembles an Upper Boulder-clay, is overlaid by finely laminated Brick-clay with shells, but containing few stones, from 8ft. to 10ft. thick; while the shelly clay is capped in turn by stratified Sands and Gravels. There can be little doubt that this shelly clay is of the same age as the marls north of Ramsey, and, if so, then there is here direct evidence that the shelly clays are more recent than the Upper Boulder-clay. Again, Mr. Birds ranks all the Boulder-clays, other than the shelly clays, as belonging to his upper series. ‘This Upper Boulder-clay,” says the author, “was not formed altogether during the second continental period, but probably it was deposited during the middle or towards the latter end of the emergence, and continued to be deposited for some time during the second submergence.’’? 1 See Grou. Maa. Feb. 1875, p. 82, e¢ seq. Notices of Memoirs—Prof. A. H. Church. ool His diagrams, which are intended to illustrate this statement, show that he believes his Upper Boulder-clay to be PosrErior to the “Middle Drift” or Kame series. What are the reasons assigned by the author for slumping these Boulder-clays as part and parcel of his upper series? Because “this clay is found almost always at a higher level than the Middle Drift Sands, and from its containing scarcely any but local rocks, and those always angular or in a very slightly rolled condition, I conclude that it is the wash of the mountains towards the later part of their rise and in the beginning of their second submergence in the sea, and due partly to the action of the sea itself by tides and waves, partly to rainfall and an accu- mulation of snow and ice upon the land, combined with the most effective cause of all—the grinding of coast-ice swept along by violent currents.” In the absence of any direct evidence of super- position, I fear that these arguments can have but little weight. In Scotland, for instance, true Lowrr Boulder-clay occurs very fre- quently at higher levels than the Kame series; and in the Till there always is a preponderance of local over foreign rocks, the number of the latter diminishing in proportion to the distance from the parent source. As to the last of these reasons, my observations enable me to state that such is nor the case with reference to all the Boulder- clays included in his upper series.1_ In the case of those Boulder- clays described in my paper as representing true Till, the stones are neither angular nor slightly rolled; on the contrary, they have the smoothed character of ordinary Till stones with well-marked scratches. Mr. Birds indicates localities unvisited by me, and, of course, I have nothing to say with reference to these sections. The author further says: ‘“‘As to which is the true order of the formations, the question must be determined, of course, by reference to sections, such as that of which Mr. Horne has given a lithograph, near the mouth of the Ballure Glen, and by all sections thence along the northern base of the hills to Kirkmichael.” Glancing for a moment at this section exposed on the coast cliff, we have here two Boulder-clays, regarded by Mr. Birds as belonging to his upper series, which are separated by sands and gravels and capped by stratified sands and gravels, which appear to stretch northwards to Ramsay, where the “Middle Drift” series begins. This section seems to indicate that these Boulder-clays pass UNDERNEATH the stratified sands and gravels of the ‘Middle Drift” series. Other sec- tions might be adduced which seem to point to the same conclusion. NOE hear SS Oia Ver VEO aE S- Rep CHatrK AND Rep Cray. By Proressor A. H. Cuurcu. From the “Chemical News,” May 7, 1875. OME years ago I published an analysis* of the Red Chalk of Hunstanton, Norfolk. The specimens which I examined more minutely were those in which the red colour, so characteristic of this variety of chalk, was exceptionally developed. In these speci- 1 See Trans. Geol. Soc. Edin. vol. ii. part iii. 2 1863. Journ. Chem. Soe. (2), vol. i. p. 99. 332 Notices of Memoirs—Prof. A. H. Church— mens I found a high per-centage of ferric oxide, with very little silica and alumina. Mr. R. C. Clapham had shown,! however, that some samples, at all events, of red chalk contained as much as 9°28 per cent. of silica, with 9-6 per cent. of ferric oxide and 1-42 per cent. of alumina, and that these three ingredients were also present in white chalk, though in much smaller proportions. In view of the recent discoveries as to the materials constituting the floor of the deep sea, and acting upon a suggestion made by Professor J. Morris as to the probability of some near connexion between red chalk and the ‘red clay” of certain deep tracts of the ocean bottom, I have again studied the chemical nature of the former material; but this time I employed a different method of analysis, and I operated upon the paler and more ordinary variety of red chalk. The samples used were numerous, but the results of the treatment to which they were submitted were nearly uniform. The following is a brief outline of the plan which was pursued in order to see if it were possible to separate from red chalk a red clay, slime, or ooze, similar to that which is reported by the officers of the Challenyer Expedition to cover the Atlantic bed at average depths of some 2700 fathoms. Treatment with very dilute hydro- chloric acid in the cold seemed the best way of removing the calcium. carbonate present. This acid was allowed to act upon small crushed pieces of selected red chalk until fresh acid failed to remove any further traces of calcium. By appropriate washing in an apparatus similar to that figured in my “Laboratory Guide,’’? the finer portion of the undissolved residue from the chalk was readily separated from the siliceous fragments which accompanied it. This finer portion remains suspended for some time when stirred up in pure water, and was found to be almost, if not quite, homogeneous; it contained no ime. It amounted, on the average, when air-dried, to 9:3 per cent. of the weight of the chalk taken, but some dark samples furnished higher per-centages. Its physical characters corre- spond, so far as I can learn, to those of the red residue obtained by Mr. Buchanan from the Globigerina ooze, and to those of the smooth red clay before referred to as brought up from the deeper parts of the sea-bottom. The following analysis abundantly proves how eloseiy the chemical composition of the red argillaceous residue from red chalk resembles the red clay in question : Analysis of Red Clay from Red Chalk. In 100 Parts. A a ae Sek Gees al} hte Dried. Dried at 100° C. Ignited. Wiater wwe. fae ee ee a) AS 7°54 — Silica . 5 a, OPPS 57°33 62:01 Ferric oxide (Fe, 0.) o 9 URS 13°89 15-02 Alumina . eee alos65 16:97 18°36 Magnesia (Mgo) A role ade ener Os) 2°87 3°11 Potash (K20) . . . . 1°88 1:45 1:56 100-04 100-05 100-06 1 1862. Chemical News, vol. vi. p. 318. 2 “ Laboratory Guide,” 3rd edition, 1874, p. 163. Analysis of Red Chalk and Red Clay. 333 Although the above numbers clearly indicate a substance which may be fairly designated “a silicate of red oxide of iron and alumina,” like the “red clay” of Professor Wyville Thomson,! it would be idle now to speculate as to the probable correspondence, in the minuter details of their composition, of the red chalk residue with the red clay of the deep Atlantic and Southern Sea. Still it may be profitable to allude to two or three points which are likely to throw light upon the relationship of the white, grey, and red chalk with the globigerina, the grey and the red ooze, respectively. First, analysis seems to show that the removal, in different degrees, of caleareous matter, however effected, has been the main cause of the differences of such formations. Secondly, it would appear that, although manganese dioxide is present in granules and nodules in the red oceanic clay and in the coarser particles of the red chalk, it is absent alike from the finely-divided substance of the former and the similar red residual slime of the latter. And, thirdly, the suggested relation beetween both these red matters and the mineral known as glauconite receives an unexpected light through the detection of sensible quantities of magnesia and potash in the red chalk residue ; for the latter base is an invariable constituent, and the former an usual one of this species. The complex and rather variable silicate which, from its grey- green hue, has received the name of glauconite, is known both in ancient and recent formations of greensand. The casts of animal forms which constitute the glauconitic grains of Cretaceous Greensand strata are paralleled by similar remains in the recent greensands of the Australian seas, and of those of the Agulhas current inyestigated by the scientific staff of H.M.S. Challenger. But the problem of the formation of recent greensand, or rather of glauconitic matter, at moderate depths, and of the related red clay at very great depths, is not yet solved. It is by no means necessary to suppose that glauconite was always first formed, and that it yielded the red clay in question by oxidation and partial solution, just in the same way that kaolin or white clay has been produced from felspar. This has probably happened in some instances; but it may be assumed, on the other hand, that the same constituents have yielded one or other of these two products, in accordance with differences in the dissolved gases and salts of the ocean and in the nature of its prevalent animal and vegetable forms. One step towards the discovery of an answer to the problem now under discussion might be furnished by a careful study of the action, under pressure, of water holding oxygen and carbon dioxide in solution, upon powdered glauconite. But we really stand in need of more information as to this species itself, for the composition of the numerous minerals included under this name is somewhat ill- defined. Still we may conclude that it contains, as essential con- stituents, silica to the extent of 50 per cent.; a variable amount of alumina; much iron in the ferrous, as well as in the ferric condition; several per cents of potash; a little magnesia: and, finally, about 1 Proc. Roy. Soc., vol. xxiii. pp. 39 and 45. O04 Reports and Proceedings— 7 or 8 per cent. of water. It would not require a very profound alteration of such a mineral to give it the composition indicated by the analysis of our red chalk residue when dried at 100° C. Such alteration would involve peroxidation of the iron, removal of most of the potash, and relative increase of the alumina, results commonly seen in many altered mineral residues. Great interest attaches to all questions concerning the red oceanic clay. Its minute analysis will, doubtless, solve some of the problems referred to in the present imperfect note. In the mean time, I am anxious that it should not be supposed that I ignore the differences which must subsist between recent oceanic deposits and the rocks which we may consider to have originated in former ages from similar materials. It is not that the mere process of consolidation must have altered them, but that the influences to which they have been subsequently exposed may have caused unsuspected, though not inconsiderable, changes in their chemical constitution. Materials for the discussion of this question are still deficient, and we must await complete quantitative analyses of recent glauconite, and of the ‘red oceanic clay, before a decision can be reached. On account of this insufficiency of data, I have refrained from suggesting any formula for the red chalk residue, though it may have, like kaolinite, a claim to be regarded as a mineral species. sEviEn TE @ ie we SS PASI) | Ee @ Carson sl sING Se eR Ras GxoLocicaL Sociery or Lonpon.—May 12th, 1875.—John Evans, Hsq., V.P.R.S., President, in the Chair.—The following communica- tions were read :— 1. “ Notes on the Occurrence of Lozoon canadense at Cote St. Pierre.” By Principal Dawson, LL.D., F.R.S., F.G.S. The author commenced by describing the arrangement and nature of the deposits containing Hozoon at the original locality of Cote St. Pierre on the Ottawa River. The Eozoal limestone is a thick band between the two great belts of gneiss which here form the upper beds of the Lower Laurentian. Hozoon is abundant only in one bed about 4 feet thick; but occasional specimens and fragments occur throughout the band. The limestone contains bands and concretions of serpentine, and is traversed by veins of chrysotile; the former an original part of the deposit, the latter evidently of subsequent formation. A thin section, 54 inches in depth, showed :—1. Lime- stone with crystals of dolomite and fragments of Hozoon; 2. Fine- grained limestone, with granules of serpentine, casts of chamberlets of Hozoon and of small Foraminifera; 3. Limestone with dolomite, and containing a thin layer of serpentine; 4. Limestone and dolo- mite with grains of serpentine and fragments of supplemental skeleton of Hozeon; 5. Crystallized dolomite, with a few fragments of Hozoon in the state of calcite; 6. Limestone containing serpentine, as No. 2. The author criticized some of the figures and statements put forward by Messrs. King and Rowney, and noticed two forms of Hozoon, which he proposed to regard as varieties, under the names of minor Geological Society of London. 335 and acervulina. He stated that fragments of Hozoon, included in dolomitic limestones, have their canals filled with transparent dolo- mite, and sometimes in part with calcite. In one specimen a por- tion was entirely replaced by serpentine. The author called parti- cular attention to the occurrence of serpentinous casts of chamberlets, single or arranged in groups, which resemble in form those of the Globigerine Foraminifera. These may belong either to separate organisms, or to the Acervuline layer of the Hozoon ; the author proposes to call them Archeospherine, and describes them as having the form and mode of aggregation of Globigerina, with the proper wall of Hozoon. The author discussed the extant theories as to the nature of Hozoon, and maintained that only that of the infiltration of the cavities of Foraminiferal structure with serpentine is admis- sible. He particularly referred to the resemblance of weathered masses of Hozoon to Stromatoporoid Corals. 2. “ Remarks upon Mr. Mallet’s Theory of Volcanic Energy.” By the Rey. O. Fisher, M.A., F.G.S. Mr. Mallet’s paper, read before the Royal Society in 1872, was discussed by the author seriatim as far as it seemed open to criti- cism. With respect to the condition of the earth’s interior, whether it be rigid or not, Sir W. Thomson’s arguments for rigidity were referred to, and geological difficulties in accepting his conclusions suggested. Mr. Mallet’s views regarding the formation of oceanic and continental areas, that they have on the whole occupied nearly the same positions on the globe at all periods from the very first, were excepted to on the ground that all continental areas with which we are acquainted are formed of water-deposited rocks, and that therefore those areas must at some time have been sea- bottoms ; and if these wide features have not occupied the same positions which they now do from the very first, Mr. Mallet’s ex- planation fails, that they were caused by unequal contraction when the crust was first permanently formed and thin. It was also shown that the theory of unequal radial contraction cannot account for the difference of elevation between continental and oceanic areas upon reasonable assumptions. or if we consider the crust to have been 400 miles thick (which cannot be considered thin), and to have cooled from 4000° F. to zero (a most extravagant supposition), then, if the crust had contracted one-tenth more beneath the oceanic area than it had done beneath the continental, we should only get a depression of one mile for the oceanic area, using Mr. Mallet’s mean coefficient of contraction. The main feature of Mr. Mallet’s theory was then discussed, viz. that “the heat, from which terrestrial volcanic energy is at presi nt derived, is produced locally within the solid shell of our globe, by transformation of the mechanical work of compression or crushing of portions of that shell, which compressions and crushings are themselves produced by the more rapid contraction by cooling of the hotter material of the nucleus beneath that shell, and the con- sequent more or less free descent of the shell by gravitation, the vertical work of which is resolved into tangential pressures and 336 Correspondence.— Mr. G. H. Kinahan. motion within the shell.” Mr. Mallet’s mode of estimating the amount of heat derivable from crushing a cubic foot of rock was explained, and it was accepted as a postulate, that the heat de- veloped by crushing one cubic foot of rock would be sufficient to fuse 0-108 of a cubic foot of rock; or, in other words, that it would require nearly the heat developable by crushing ten volumes to fuse one. Mr. Mallet considers that the heat so developed may be localized. But Mr. Fisher inquires why, since the work is distri- buted equally with the crushing, the heat should not be so also; and since no cause can be assigned why one portion of the crushed portion of rock should be heated more than the rest, assumes that all which is crushed must be heated equally. In short, he is of opinion that if Mr. Mallet’s theory were true, the cubes expe- rimented upon ought to have been themselves fused. After paying a just tribute of admiration to Mr. Mallet’s elaborate and highly important experiments upon the fusion and subsequent contraction of slags, the author remarked upon Mr. Mallet’s estimate of the probable contraction from cooling of the earth’s dimensions, showing that it had been based on untenable assumptions. (The author of the paper, however, holds that the contraction of the dimensions of the globe has been greater than mere cooling will account for.) Upon the concluding portions of Mr. Mallet’s paper, in which he estimates that the amount of energy afforded by the crushing of the solid crust would: be sufficient to account for ter- restrial vulcanicity, some strictures were made; but it was held that, if the main proposition had not been proved, these calculations were not of essential importance. The Meeting was made special for the election of a Member of Council and of a Vice-President in the room of the late Sir Charles Lyell, Bart. W. Carruthers, Esq., F.R.S., F.G.S., was elected a Member of Council, and Sir P. de M. Grey-Egerton, Bart., M.P., F.R.S., F.G.S., a Vice-President of the Society. COS Sine aN zeae PEEL SREY DENUDATION OF THE WEALD. Sir,—I regret much that the gallant author of ‘“‘ Rain and Rivers” should think I had robbed him of one of his numerous honours; but at the same time I cannot feel that I am guilty. Messrs. Foster and Topley are not referred to as the authors of the Subaerial Theory of the Denudation of the Weald Valley, but as the authors of a memoir containing the information I required. Moreover, it would ap- pear superfluous to mention Col. Greenwood’s name, as the few read- ers I may have, must be fully acquainted with “Rain and Rivers.” I appear to have been unfortunate in my selection, as the Denudation of the Weald seems to be an apple of discord, the gallant Colonel being the third claimant who has called me to task for having mentioned Messrs. Foster’s and Topley’s names. THe AurHor oF “ VALLEYS AND THEIR RELATIONS TO Favtts,” ETC.! WEXFORD, June 4th, 1875. 1 London, 1875, Trubner and Co., 8vo. pp. 240. NEW SERIES. Decade Il. Vol. {1 PLX. see ts rent 6 x 50 ETN = de el et Auto-hith TAS MANITE iS o 1B) Ww 1 R= 1B WD) GO AIL, THE GEOLOGICAL MAGAZINE. NEW: “SERIES? * DECADE (We -VOk.e Il, No. VIII—AUGUST, 1875. OH EGAENAST a ASE a @ ean. —__—_ I.—On “ TASMANITE” AND AUSTRALIAN “ WHITE COAL.” By E. T. Newron, F.G.S., Assistant Naturalist, H.M. Geological Survey. (PLATE X.) HE two substances known as “Tasmanite” and Australian. “White Coal,” which are the subject of the present communi- cation, have a special interest for the geologist on account of the light which they throw upon the microscopic structure and com- position of many Coals. My attention was first directed to them when collecting materials for Professor Huxley’s examination into the microscopic structure of Coal. My esteemed colleague, Mr. Etheridge, at that time gave me a specimen of brown laminated substance, labelled ‘‘ Lignite, the so-called White Coal, Australia,’’ and drew my attention to the fact that it was very largely composed of small seed-like bodies, very similar to, although smaller than, the macrospores' of Flemingites, which are to be seen in many kinds of British Coal. A specimen of this same kind of White Coal is in the Museum of Practical Geology, and is labelled, “ Bituminous Shale (locally called White Coal), New South Wales, Australia.” I have likewise been able to examine the specimen of Tasmanite also in this Museum, which is labelled ‘“Tasmanite ; combustible matter from the river Mersey on the north side of Tasmania; stratum of unknown thickness, but known to extend for some miles. Presented by Sir Wm. Denison.” These specimens are very similar in appearance and structure, but the White Coal is softer than the Tasmanite. Chemical analyses of Tasmanite have been published, but I am not aware of any satisfactory account of its microscopic structure. The only mention of Australian White Coal with which I am acquainted is that in Prof. Huxley’s lecture on “On the Formation of Coal” (“Contemporary Review,” Nov. 1870). And there is a figure, of a section and some separated spores, given by Sir C Lyell in the 2nd edition of his Student’s Hlements of Geology, 1874. The general appearance of the combustible schist, which is now generally known as Tasmanite, is thus described by Mr. J. Milligan, 1 The bodies existing in Coals which have usually been termed Sporangia and Spores have been shown by Prof. Williamson. to be Maerospores and Microspores. 1 believe both Professor Huxley and Mr. Carruthers are prepared to accept this determination. DECADE II.—VOL. II.—NO. VIII. 22 338 EF. T. Newton—On “ Tasmanite” and “White Coal.’ in the earliest account of this substance which I have yet seen (Report of the Royal Society of Van Dieman’s Land, 1852, p. 96): “There is on the right bank of the river [Mersey, ] a series of beds of a brown schist,’ of a nature highly combustible ; its surface is usually finely punctated—it is semi-soft, sectile, fissile, flexible, and slightly elastic, and when held to a candle ibn iin a strong yellowish-white flame.” When the substance thus described is examined with a pocket lens it is seen to be very largely composed of minute discs of a brownish colour, giving to the schist a granular aspect; this is probably the appearance alluded to in the above extract as “finely punctated.” The chemical analyses of Tasmanite made by Prof. Penny (Pro- ceedings of the Royal Society of Van Dieman’s Land, vol. ii. 1855, p- 10&) and by Prof. Church (Philosophical Magazine, vol. xviii. 1864, p. 465) show that the discs are composed of a kind of resinous material, and that they are imbedded in a matrix of siliceous sand and clay. It is perhaps worthy of remark that Prof. Penny puts the resinous matter at 26:24 per cent., and pyrites at 2°16 per cent. ; while Prof. Church says the resinous matter forms 30 to 40 per cent. of the schist, and makes no mention of pyrites ; he states however that the resinous matter contains a very large proportion of sulphur in chemical combination. It appears from the observations of these two authors that the so-called resinous portion of Tasmanite is not really resinous, for it is insoluble in alcohol, ether, bisulphide of carbon, benzole, tur- pentine, and paraffin oil. Now the so-called bituminous portions of coal differ from resins in very much the same particulars; and when we find also that Tasmanite “affords a notable quantity of gas, which is similar in quality and powers to that obtained from cannel coal,” although less in quantity, we must, 1 think, consider Tasmanite and Coal to be allied substances. The large proportion of sulphur, which Prof. Church has shown to be in chemical combination in Tasmanite, is paralleled in the case of certain coals mentioned by Dr. Percy (Fuel, 1875), as being remark- able for the same peculiarity. By the kindness of Mr. W. J. Ward, I am enabled to give the follow- ing particulars regarding the composition of Australian ‘‘ White Coal” : Combustible Materials .. 29°58 Aish (eo Sin Soa eee pasa OO 47) Wrateres5 2 pre SE aaa eee er Oe) 100:00 After treating this White Coal, in a finely divided condition, with hydrochloric and hydrofluoric acids, and separating a small propor- tion of whitish sand by decanting, there was about 43°61 per cent. of residue, chicfly composed of the discs, but evidently still containing a small proportion of sand or clay, which had not been dissolved ‘by the acids. 1 Allied to Dysodile. E. T. Newton—On “ Tasmanite” and “ White Coal.” 339 A portion of the discs carefully separated by sifting and again treated with hydrofluoric acid gave Combustible material... ... 96°63 Ash (brightred) ... ... 3°37 100:00. In order to ascertain the true nature of the discs, in either Tasman- ite or White Coal, it is necessary to prepare thin slices of the schist for microscopic examination, and also, for the same purpose, to separate the discs by treatment with hydrochloric or nitric acid. When the separated discs are viewed by reflected light, they appear as more or less circular bodies, somewhat thickened towards the circumference, many of them having their surfaces raised into irregular folds. If mounted in Canada Balsam, and viewed by transmitted light, many have the appearance represented in Pl. X. Figs. 2, 3, 8, while others exhibit the folds to which allusion has just been made. The more perfect discs are seen to be surrounded by a double contour-line—the optical expression of the fact that these dises are really thick-walled sacs. The saccular character, however, is best seen in transverse sections (Figs. 1, 4, 5), or when the sac is broken (Fig. 8). A closer examination enables one to see that the walls of these sacs are not homogeneous. A view suchas Fig. 8 shows numerous dots scattered over the surface, which become some- what elongated towards the edges of the disc. When examined with a power of about 250 diameters, the dots can be resolved into minute circles about ,,!,, of an inch in diameter with a still smaller dot in the centre, as shown in Fig. 9. These structures are best seen in the discs of White Coal. It may be thought that these dots are com- parable to the granules to be seen upon the surface of some of the macrospores of Flemingites; but the study of transverse sections shows at once that these dots are not mere surface-markings, for they can be distinctly traced as minute lines (tubes ?) passing from the outer to the inner surface. These lines are shown in Fig. 5, but owing to the section not being quite in the same plane as the lines, they do not appear to extend quite through. In addition to the fine lines, the walls of the sacs exhibit obscure longitudinal markings, which give them a laminated appearance (Fig. 5). _ Neither Mr. Carruthers (Gron. Mac. 1865, p- 4382), nor Mr. MacNaughton (Trans. Roy. Soc. Van Dieman’s Land, vol. ii. 1855, p. 116), mentions any structure in the walls of these sacs. The discs vary in diameter, as stated by both these authors, from about ;!, to 4, of an inch. Mr. MacNaughton speaks of a thin outer coat to these discs, which may be seen when they are ruptured. I have examined all my preparations, both sections and separated discs, in order to distinguish this outer coat, but have been unable to do 80. One easily recognizes in transverse sections, such as Fig. 1, that the walls of the sacs vary much as regards thickness; and among the separated sacs which are mounted in Balsam some may be seen much more transparent than the rest; but I have failed to see any real difference between the thicker and the thinner sacs, or to find them in anything like the relation of an inner and outer coat. 340 #. T. Newton—On “ Tasmanite”’ and “White Coal.” Nearly all the sacs are so compressed that their walls are brought into contact ; but occasionally one may be found similar to Fig. 6, containing a quantity of black material differing in appearance from the surrounding matrix, and which appears to consist of minute rounded particles, about 1. of an inch in diameter. With regard to the affinities of the discs, or rather sacs, it must be acknowledged that their true nature has yet to be determined. Their general structure seems to indicate that they are the spores or sporangia of some Lycopodiaceous plant; but their true affinities must remain obscure until they are found in their natural relation to the parent plant, or some recent form is discovered with which they: can be compared. By the kindly help of Mr. Carruthers, I have been enabled to examine the fructification of several recent forms, but have failed to find anything comparable in structure to these sacs. Prof. Balfour, I believe, considers the Tasmanite discs to be closely allied to Flemingites; they differ from them, however, as Mr. Carruthers has pointed out (Guo. Mace. 1865), both in structure and size. All the Flemingites macrospores which I have seen have homogeneous walls, and in many of them is seen the triradiate marking, which is so generally present in cryptogamic spores (Prof. Williamson, Macmillan’s Mag. March, 1874, p. 409). In none of the Tasmanite sacs have I been able to see this triradiate marking, although their structures are so clearly shown that these markings could not fail to be seen if they were present; and the walls, as we have already seen, have a definite structure. The sporangia of Lepidostrobus figured by Dr. Hooker (Mem. Geol. Survey, 1848, vol. li. part it pl. 6, figs. 4, 10, and pl. 7, fig. 7) have somewhat the same appearance as the transverse sections of Tasmanite sacs, that is to say, they show a series of lines perpendicular to the surface. A closer examination, however, of the figure, or, still better, of the original specimens, shows that the two structures are not the same. In the Lepidostrobus sporangia the lines are really the walls of the cells of which the sporangia are composed. In the Tasmanite sacs the lines have quite a different appearance, and a surface view shows that they are not merely the lines of junction between cells. The minute black bodies mentioned above as filling the cavities of some of the discs are very much smaller than any of the microspores mentioned by Prof. Williamson (Macmillan’s Mag. March, 1874, p. 408), and they do not show any cell wall. In the abstract of a paper by Mr. Thos. 8. Ralph (Trans. Roy. Soc. Victoria, vol. vi. 1865, p. 7), the discs of Tasmanite are referred to Algz. This, I venture to think, is improbable. There can be no question as to the Tasmanite sacs being vegetable organs, although at present we do not know the plant to which they belong. Their size and form seem to indicate that they are more nearly allied to Lycopodiaceous macrospores than to anything else. The inconvenience of having an object without a distinctive name induces me to propose one for the spores (?) found in Tasmanite and Australian White Coal (the two being, as I believe, identical in struc- ture) ; and in order to retain existing titles as far as possible, 1 would E. T. Newton—On “ Tasmanite” and “ White Coal.” 9841 suggest that Prof. Church’s name Zasmanite, which is so generally used in reference to the schist as a whole, be retained for this substance, and that the spores (or rather the plant to which they belong) should be called Tasmanites, with the specific title of punctatus, in allusion to their surface-markings. The piece of Tasmanite drawn in Figure 1 was chosen on account of its exhibiting portions in which the spores are unusually far apart, and others where they are more numerous and compressed. It is this compressed portion which so closely resembles the structures seen in many coals, and which Prof. Huxley believes to be masses of spores and sporangia (Contemporary Review, Nov. 1870). Improb- able as it may seem to some persons that the combustible portions of a bed of coal several feet in thickness should be for the most part composed of spores, yet such is undoubtedly the fact in the case of Tasmanite and Australian White Coal. In both these substances the combustible portion consists entirely of sacs (spores ?), no other vegetable matter whatsoever being traceable. If a section of Better Bed Coal, such as that mentioned by Prof. Huxley, be compared with one of Tasmanite or Australian White Coal (see Figures I and 10), the similarity of their structures will be at once apparent. The chief difference between them being, that while in the two last there are only large spores and the spaces between these are filled with sandy matters, in the former the interspaces between the larger spores are filled in with multitudes of minute spores mixed with mineral charcoal. With regard to the mode of occurrence of Tasmanite, Mr. Milligan, in addition to the extract given above (page 338), says: “The same brown combustible schist [Tasmanite] presents itself a mile higher up the river, and on the same side, but at an elevation of more than 100 feet above the water, and then it appeared to dip slightly into a high and rather steep hill, ete. “The brown combustible schist exhibits at the elevation last mentioned a thickness of six to seven feet in one distinct seam, passing upwards into laminated clay rock of a yellowish colour, interstratified with thin layers of the schist. “ Below the six-feet seam there is, for a space, the same alternations as above, but uninterrupted beds of compact yellowish and bluish white clays succeed, etc. . “The occurrence of thick beds of fine clay and clay schists without organic remains above the fossiliferous masses [rocks previously mentioned as occurring below the brown schists and clays], denote a tranquil condition of superstant waters, compatible only with the character of a capacious and sheltered bay, or deep and extensive lake; to which supposition the subsequent deposit of repeated layers ofa highly combustible schist of undoubted vegetable origin lends great probability. “An extended and close examination of these beds, and the formations with which they are associated, and a careful comparison of their fossil contents, will be required thoroughly to establish 342 #. T. Newton—On “ Tasmanite? and ‘White Coal.” their ages in relation to each other, and to geological changes and epochs generally.” The changes in the physical condition of the land necessary for deposition of several alternations of beds of clays and schists, some of which are of considerable thickness, and the subsequent elevation of the whole to 100 feet above the level of the river, show that these Tasmanite schists cannot be of very recent origin, although the distinct and unaltered appearance of the spores might have led one to suppose that they were. The alternations of layers of the schist with beds of laminated clay rock, and the presence of masses of fossiliferous rocks below this series, are extremely suggestive, on account of their resemblance to the succession of strata in the Carboniferous Epoch ; indeed, it seems highly probable, from Mr. Milligan’s observations, that these beds of Tasmanite were deposited under conditions very similar to those under which Coal is now generally considered to have been deposited. I have at present been unable to ascertain under what conditions the Australian White Coal occurs; its great resemblance to Tasmanite renders it highly probable that it occurs under very similar conditions. The foregoing consideration regarding the composition, microscopic structure, and mode of occurrence of ‘T'asmanite, must, I think, lead to the conclusion, that this deposit is a bed of coal in process of formation ; very inferior coal no doubt, on account of the large admixture of sand and clay, but nevertheless of such a character that it would be considered a true coal. The study of Tasmanite will, I think, enable us better to understand the appearances presented by certain coals : and certainly not the least important fact to be noticed is, that the combustible portion of this deposit, which is closely allied to coal, several feet in thickness and miles in extent, is formed entirely of spores. EXPLANATION OF PLATE X. Fre. 1.—Section of Tasmanite, cut perpendicular to the plane of bedding, x 50 diameters. In the upper two-thirds of the figure the spores are further apart than is usually the case ; in the lower third they are very numerous and more compressed. Fic. 2.—A large spore of Zasmanites punctatus which has been ruptured, x 60 diameters: showing the double contour and dotted surface. Fie. 3.—A similar but smaller spore, with air in the interior; x 50 diameters. Fic. 4.—Transverse section of a spore, the walls of which have been pressed to- gether from the same section as Fig. 1; x 50 diameters. Fic. 5.—Portion of Fig. 4, x 250 diameters, to show the perpendicular lines and laminated structure. Fie. 6.—Spore filled with black material x °50 diameters. Fic. 7.—Portion of similar spore x 250 diameters, shows three of the minute rounded bodies separated from the mass. Fre. 8.—Spore of 7. punctatus, from the Australian White Coal, x 50 diameters. Fie. 9.—Portion of Fig. 8, x 250 diameters, to show the dots and extremely fine granulation of the intermediate portions of the surface. Fic. 10.—Section of Better Bed Coal, cutperpendicular tothe bedding, x 25 diameters. The large sac-like bodies are macrospores (Flemingites) ; the intermediate granular-looking portion is composed of microspores and a black material, probably mineral charcoal. : Fic. 11.—Section of same coal cut in the plane of the bedding, x 150 diameters. Small portion of intermediate part, with microspores. Prof. H. A. Nicholson—On the ‘ Guelph’ Limestones. 343 II.—On toe Guerra Limestones or Norta AMERICA AND THEIR Orcanic Rematns.! By H. Auteyne Nicuouson, M.D., D.Sc., F.R.S E., Professor of Natural History in the University of St. Andrews. pMergncce the parallelisms which may be drawn between the Silurian series of Britain and that of North America, none so far has been so certainly established as the equivalency of the “Niagara Formation” to the Wenlock Group. In its most typical development, as in the State of New York, the Niagara formation consists of an inferior series of argillaceous sediments, the “ Niagara Shales,” and of a superior series of calcareous accumulations, the “Niagara Limestone.” At the Falls of Niagara itself, and at the Falls of the Genesee at Rochester, the shales and limestones are about eighty feet in thickness each. In Pennsylvania, the Niagara formation is wholly shaly, and has a thickness of over fifteen hun- dred feet. In the States west of New York, again, the formation is almost wholly calcareous, many of its members being true dolomites, and its total thickness rarely reaches three hundred feet, and is usually much less. In Western Canada, finally, the Niagara shales can rarely be detected as a distinct group, and the formation consists mainly of limestones, often magnesian, with subordinate courses of shale, the whole usually varying from one hundred to two hundred feet in thickness. Whilst the above are the general characters of the Niagara forma- tion as developed in North America, I purpose in the present com- munication to discuss in greater detail a group of beds, which forms the uppermost member of the series in its most complete develop- ment, and which exhibits various points of special interest. The beds in question have the lithological character of magnesian lime- stone or dolomite; and, though not universally present, they are so constant in their position, and so sharply marked out by their organic remains, that they have been raised by the Canadian geologists to the rank of a distinct group, under the name of the “Guelph Formation,” from the town of Guelph, where they are found in full force. This name has not been universally adopted ; but it is convenient to use it, provided it be recollected that the deposits in question are in reality only a portion of the great Niagara Formation, of which they form the uppermost member. There are, however, strong grounds for believing, with Sir William Logan and Prof. Hall, that the Guelph Limestones, though found at points very widely remote from one another, do not form a continuous series, but that they are more or less of the nature of separate lenticular masses of unequal extent and thickness, which have been deposited on an uneven ocean bed towards the close of the Niagara period. The typical development of the Guelph Limestones is found in Western Ontario, where they were first noticed and described (Murray, Geol. Survey of Canada, Report of Progress, 1848 and 1849; Hall, Pal. N. Y. vol. ii. p. 8340; Logan, Geology of Canada, 1 Read before the Royal Physical Society, Edinburgh, Feb. 17th, 1875. 344 Prof. H. A. Nicholson—On the ‘ Guelph’ Limestones. 1863). Here they occupy a band of country which may be roughly described as extending from near the western extremity of Lake Ontario to Lake Huron, and they attain their maximum thickness in the townships of Dumfries, Waterloo, Puslinch, Guelph, Pilkington, and Nichol. They are estimated to possess a total thickness of about one hundred and sixty feet, and they consist entirely of magnesian limestones, which are usually of a buff, white, or yellow colour. The subjacent strata, which constitute the mass of the Niagara Formation, though often consisting in part of beds of magnesian limestone, have a prevailing black, blue, or grey colour, and the Guelph dolomites are readily recognized by this alone. The texture of the rock is often highly crystalline, but it is commonly very porous or almost vesicular, owing partly to the existence of drusy cavities and partly to the numerous vacant spaces left by the weathering out of organic remains. The exposures of the Guelph Limestones which are best known are those found at Guelph, Galt, Hespeler, Elora, and Fergus, and in all these localities the rocks are charged with an abundance of fossils. Good specimens, however, are very difficult to procure, and the great majority of examples are simply in the condition of casts. Some beds of the formation yield a massive and valuable building stone; and others are burnt for lime, though in this latter respect there appears to be a prevailing preference for the cherty and siliceous limestones of the Corniferous series. In the State of Ohio all the Limestones of the Niagara formation, with the exception of the celebrated “ Dayton Stone,” are magnesian, and the Guelph Limestones are consequently not distinctly marked off from the lower beds by any lithological peculiarity. The summit of the Niagara series in Ohio is, however, formed by a group of dolo- mites, which can be unhesitatingly identified with the Guelph forma- tion of Canada, not only by the precise similarity in mineral charac- ters, but also by the identity of organic remains. The Ohio geologists usually term these dolomites the “Cedarville Limestones,” or the “‘Pentamerus Limestone.” The latter name is derived from the great abundance in these beds of Pentamerus oblongus, Sow., a Brachiopod which is characteristic in Canada of the base instead of the summit, of the Niagara series. The former name is de- rived from the great development of the series at the town of Cedarville, in South-western Ohio, where it is largely quarried, and where I had the opportunity of examining it last spring under the guidance of my friend Prof. Edward Orton, of the Ohio Geological Survey. As seen at Cedarville, and a few miles to the north at the village of Clifton, the Guelph formation consists wholly of beds of massive magnesian limestone, usually destitute of distinct lines of stratification in its lower portion. In appearance the rock presents the most striking similarity to the magnesian limestone of the same _age in Canada, being of a yellowish or greyish-white colour, crystal- line, rough to the touch, and rendered more or less vesicular by the presence of numerous cavities. Fossils are abundant, but are almost wholly in the condition of casts; whilst it is a matter of the greatest Prof. H, A. Nicholson—On the * Guelph’ Limestones. 345 difficulty to obtain specimens that can be carried with comfort or convenience. Chemically the Cedarville Limestone is an almost typical dolomite, containing about 43 per cent. of carbonate of mag- nesia. In spite of this fact, it is reputed the best limestone in the whole State of Ohio for lime-burning, its lime not being “ fiery,” and taking much longer to “set,” than is the case with lime made from ordinary limestone. The thickness of the Guelph Limestones in different parts of Ohio is estimated as varying between 20 and 90 feet. (Geological Survey of Ohio, Report of Progress in 1870, . 278.) : Another development of the Guelph Limestones is known at the Leclaire Rapids on the Mississippi River, in the State of Iowa, where they were first recognized by Prof. Hall, and paralleled with the Canadian series. (Geology of Iowa, vol. i. p. 73.) The beds consist here of grey or whitish-grey magnesian limestones, of a semi-crys- talline texture, and usually vesicular from the solution of fossils. No lines of true bedding are visible, and consequently the thickness of the series in this locality is unknown. Fossils are abundant, but wholly in the condition of casts. A yellowish-grey concretionary and false-bedded limestone identical with the above has been recog- nized at Port Byron, in the State of Illinois, where it has a thickness of about 50 feet. Limestones of the same age are likewise found in the vicinity of Chicago, also in Illinois, where it has the same general characters, except that it is highly charged with petroleum. (Geolo- gical Survey of Illinois, vol. 1. p. 180 et seq.) Finally, limestones in all respects identical with the preceding, and holding many of the same fossils, have been recognized and described by Prof. Hall as ‘occurring at Racine, in the State of Wisconsin. (Geology of Wis- consin, 1861.) Orcanic REMAINS. The organic remains of the Guelph Limestones are very numerous, comparatively speaking, and are many of them peculiar; but they are badly preserved, and only certain groups have been as yet worked out with any approach to fullness. The most highly characteristic fossils of the formation belong to the groups of the Brachiopoda, Lamellibranchiata, and Gasteropoda; but it will be as well to review briefly the more important forms which are known to occur in these deposits, without attempting to give anything like an exhaustive list. The only recorded species of Protozoa from the Guelph Formation are two species of Stromatopora. One of these is the rare and interesting S. ostiolata, Nich.; the other is probably S. concentrica, Goldfuss ; but its state of preservation is such as to forbid a positive specific determination. It is, however, an exceedingly common and characteristic fossil in the Guelph Limestones of Canada, whole beds appearing to be composed of very little else. In Ohio, I have not noticed its occurrence at ali. The only other fossil which could be referred to the Protozoa, is a minute spherical body, of a calcareous nature, which occurs in myriads in some portions of the Guelph 346 Prof. H. A. Nicholson—On the ‘ Guelph’? Limestones. Dolomites both in Canada and Ohio. Most usually the actual fossil itself has disappeared, and there is nothing left but the little cavity where it was situated; but in other cases the substance of the fossil has been preserved. Pending a microscopic examination of these problematical little bodies, nothing can be said of them beyond that they are very probably of the nature of calcareous sponges, and possibly belong to Astylospongia. The corals of the Guelph Formation are neither very abundant nor very widely distributed. In Canada, the most characteristic corals are Favosites polymorpha, Goldf., Favosites (Astrocerium) venusta, Hall, and F. hemispherica, Yandell and Shumard, along with a species of Amplexus (apparently A. Yandelli, Edw. and Haime), and a fasciculate form which seems to be intermediate in its characters between Amplexus and Diphyphyllum. At Cedarville, in Ohio, I detected Favosites Gothlandica, Lam., an undetermined species of Syringopora, a large Chonophyllum allied to C. perfoliatum, Goldf., and numerous specimens of an ill-preserved species of Cladopora, resembling C. reticulata, Hall. Halysites catenularia, Linn., is also not of uncommon occurrence, and there are other forms which have not been satisfactorily determined. The remains of Crinoidea are rare or unknown in the Guelph Formation of Canada; but very numerous and singular forms belonging to this group and to the nearly allied group of the Cystoidea have been found in the corresponding deposits in Ohio, Wisconsin, Illinois, and Iowa. Amongst the Crinoids, the more important forms belong to the genera Eucalyptocrinus, Cyathocrinus, Actinocrinus, Melocrinus, Ichthyocrinus, Rhodocrinus, and Glyptaster. Amongst the Cystideans, we have not only such well-known species as Caryocrinus ornatus, Hall, but we find forms belonging to the remarkable genera Gomphocystites, Holocystites, Echinocystites, and Crinocystites, together with species of Apiocystites and Hemicosmites. The Polyzoa of the Guelph Formation have not as yet been worked out, so far as I am aware. In Canada, I have never succeeded in detecting any examples of this class in the Guelph dolomites; I found them, however, to be very abundant, though badly preserved, at Cedarville and Clifton in Ohio. The most abundant are Fenestelle, belonging to at least three species. Very abundant, also, is a species apparently referable to Hall’s genus Tichenalia (= Cyclopora, Prout?). A very similar form is found in the underlying Clinton Formation at Yellowsprings, a few miles to the north of Cedarville, and it constitutes one of the commonest and most characteristic fossils of the formation. The species is clearly distinct from JZichenalia concentrica, Hall, which occurs in the Niagara group proper, and seems more closely to resemble the Cyclopora polymorpha, Prout, of the Sub-Carboniferous series; but further examination will probably show it to be new. Lastly, there occurs a species of Ptilodictya, also apparently new. The Brachiopoda of the Guelph Formation are individually very numerous, and are highly characteristic. Foremost amongst them come the Trimerellids, which the researches of Billings, Dall, Lind- Prof. H. A. Nicholson—On the ‘ Guelph’ Limestones. 347 strom, Hall, Davidson, and King have made paleontologists so thoroughly acquainted with. The most abundant members of this family are Trimerella grandis, Billings, 7. acuminata, Billings, MJono- merella prisca, Billings, and Dinobolus Galtensis, Billmgs. In Ohio, the most abundant species is Tvrimerella Ohioensis, Meek, which, though very local in its distribution, is in places common enough. After the Trimerellids, the most characteristic and abundant form is the great Pentamerus occidentalis, Hall, which is found both in Canada and the United States. In Ohio, however, the formation is so richly charged with Pentamerus oblongus, Sow., that it is often termed on this account the “‘ Pentamerus Limestone ;” whereas this well-known shell is in Canada, curiously enough, almost confined to a thin bed at the base of the Niagara Limestone. So strictly is this the case, that the bed in question, under the name of “the Penta- merus band,” has usually been employed by the Canadian geologists to separate the Niagara Formation from the underlying Clinton Formation. Another not uncommon form is Pentamerus (Penta- merella) ventricosus, Hall; whilst other forms have been recorded belonging to Spirifera, Charionella, Strophomena, ete. The Lamellibranchiata of the Guelph formation, so far as Canada is concerned, appear to be wholly referable to the remarkable genus Megalomus. Casts of the interior of the large and massive Megalomus Canadensis, Hall, are found in almost all the localities where the Guelph Limestones have been detected, though nowhere so abun- dantly as in Western Ontario. In some places, as in the cliffs of the Grand River below Elora, whole beds appear to be made up of this bivalve; but it is difficult to obtain specimens in which the actual shell is preserved. Another smaller species of the genus was described by Mr. George J. Hinde and myself from the Guelph for- mation of Hespeler, under the name of J/egalomus compressus (Cana- dian Journal, vol. xiv. p. 148, fig. 6). In the Guelph Limestones of Wisconsin, in addition to Megalomus Canadensis, Prof. Hall has described species of Lamellibranchiata belonging to the genera Am- bonychia, Pterinea, Avicula, Cypricardinia, Modiolopsis, Amphiceelia, Cypricardites, and Paleocardia. Perhaps the most abundant and characteristic fossils in the Guelph formation—at any rate in Canada—are, however, the Gasteropoda. The three genera which are most largely represented are Murchisoma, Pleurotomaria, and Holopea, and of the first-named of these the variety of species is something quite extraordinary. Speaking generally, the following may be cited as being the most abundant and characteristic forms of the Gasteropoda in the Guelph formation : —WMurchisonia macrospira, Hall; MW. Logani, Hall; M. turritiformis, Hall; I. Vitellia, Billings; MZ. bivittata, Hall; M. longispira, Hall; UM. Estella, Billings; I Hercyna, Billings; M. Laphami, Hall; Cyclonema (?) elevata, Hall; C. sulcata, Hall; Pleurotomaria solari- oides, Hall; P. Elora, Billings; P. Galtensis, Billings ; Holopea Harmonia, Billings; H. Gracia, Billings; H. Guelphensis, Billings ; Trochonema fatua, Hall; Subulites ventricosa, Hall; Bucania angus- tata, Hall; Strapacollus Daphne, Billings; and S. Mopsus, Hall. 348 J. W. Judd—On Volcanos. Prof. Hall has likewise described from the Guelph formation of Wisconsin such well-known Niagara Gasteropods as Platyceras Nia- garensis, Hall, and Platyostoma Niagarensis, Hall. At Cedarville, so far as my observation went, the Guelph Limestones are destitute of Gasteropods; but they occur elsewhere in the State of Ohio in this deposit in considerable numbers. As regards the Cephalopoda, the Guelph Formation has proved in Canada to be very barren; but in the United States the same forma- tion has yielded species belonging to the genera Nautilus, Lituites, Orthoceras, Cyrtoceras, Gomphoceras, Phragmoceras, and Trochoceras. Finally, the Guelph Formation of Canada is almost destitute of the remains of Crustaceans. In Wisconsin, on the other hand, Crustaceans are not at all uncommon. Amongst these are such familiar forms as Calymene Blumenbachii, var. Niagarensis ; Illenus Barriensis, Murch.; Ceraurus insignis, Beyrich; and Spherexochus mirus, Beyrich. Besides these, there occur new and peculiar forms belonging to the genera Flenus, Bronteus, Dalmannia, Acidaspis, Leperditia, etc. From the above brief review it will be seen that the fauna of the Guelph Formation is to a large extent a peculiar one, many of the known species being restricted to this particular horizon. The most characteristic features in the Guelph Fauna are afforded by the pre- dominance of Trimerellide and Pentameri amongst the Brachiopoda, the great abundance and variety of the Gasteropoda, and the preva- lence of the remarkable Lamellibranchiate genus Megalomus. These features are so general, that, taken along with the peculiar litho- logical characters of the rock, they justify us in regarding the Guelph dolomites as constituting a distinct series of deposits. At the same time, it is to be recollected that these deposits are clearly only a subordinate stage in the great Niagara Formation, of which they form an integral portion. IlJ.—Conrtrisutions to tHE Stupy or Vorcanos.! By J. W. Jupp, F.G.S. THe GREAT ORATER-LAKES OF CENTRAL ITALY. N no part of Europe, probably, can we find such striking examples of the effects which may be produced by single paroxysmal out- bursts of volcanic force, as in the band of igneous rocks which stretches through nearly the whole length of the Italian peninsula, on the western side of, and parallel to the chain of the Apennines. Hitna and many of the extinct volcanos of this continent constitute, it is true, mountains of vaster bulk than any in the district to which we have referred ; but while the former were evidently built up by the accumulation of the products of igneous forces operating during long periods from the same centres, and with comparatively moderate violence, the enormous craters of the latter bear witness to.the occur- rence of single outbursts of these forces of far greater intensity. The materials which have been ejected from the various centres of 1 Concluded from page 308. J. W. Judd—On Volcanos. 349 activity along this great volcanic band present many features in common ; especially in the abundance of leucite and the group of minerals allied to it; there are also not a few points of peculiar interest in connexion with these rocks which have been very admirably treated by Professor vom Rath in his ‘‘ Geognostiche-mineralogische Fragmente aus Italien.” Without, however, staying to dwell upon these subjects, we shall proceed to notice the proofs which exist of the occurrence of those volcanic outbursts of extraordinary violence or duration to which we have referred, and which have resulted in the production of some of the most marked and striking of the physical features of the district. The frequency of the occurrence of lakes in volcanic districts is a . circumstance that is familiar to all geologists. Sometimes, as in the case of the Lac de Chambon in the Mont Dore, the throwing up of a series of volcanic cones in the midst of a valley has arrested the drainage, and given rise to the formation of a lake; in other cases, precisely similar effects have resulted from the influx of a great current of lava across a line of drainage. There are not wanting proofs, also, that those local subterranean movements to which volcanic districts are especially subject have frequently so altered the levels along a line of river-valley as to lead to the damming up of the stream, and to the consequent production of lakes. In all these cases the lakes have been formed by the joint action of aqueous and igneous forces. But there are also many examples of lakes the basins of which clearly owe their origin to the action of igneous causes alone. Such are the well-known Maare of the Hifel, and those numerous depressions common in almost all volcanic districts, which are evidently old craters that have become filled with water. But lying to the northward of Rome we find two lakes of such vast proportions—the Lago di Bracciano being 63 miles in diameter, and the Lago di Bolsena 10 miles—that we may at the first sight of them be fairly led to hesitate in referring their formation to the ordinary explosive action of voleanos. Dr. Daubeny, indeed, appears to have been so staggered by their enormous size, that he found it impossible to accept their volcanic origin. In the present chapter we purpose to notice those features presented by them which appear to place their mode of formation beyond question. In seeking to illustrate the characters and to account for the pro- duction of these vast craters, it will be well to refer, in the first instance, to examples of a precisely similar kind, though on a somewhat smaller scale, the mode of origin of which it is not possible to doubt. Vesuvius presents us with a great encircling crater, that of Somma, which has a diameter of two miles and a half, and which was produced during the grand paroxysmal outburst of A.D. 79. There seems to be now no room for doubt that at the period of this grand eruption, concerning which we possess such interesting historical details, the original cone of Somma was completely gutted, and that vast cavity formed in the midst of which the existing cone of Vesuvius was subsequently built up. Here, then, we have an illustration of the effects which may be produced by a single eruption 300 J. W. Judd—On Volcanos. of a volcano, and may fairly employ it for comparison with others, concerning the formation of which we have neither historical records nor traditions to aid us, and which may possibly indeed have origin- ated prior to the appearance of the human race upon the earth. Such an example we have in the great volcano of Rocca Monfina, which presents so many points of analogy with Vesuvius that the geologist will have no difficulty in recognizing the mode of origin of the principal features of the former, though it has long been extinct, and its rocks have suffered greatly from the action of denuding forces. The mountain group of Rocca Monfina exhibits a crater-ring of about three miles in internal diameter, that is to say, it is somewhat greater than the similar crater-ring of Somma, which surrounds the modern cone of Vesuvius. The materials which compose these older encircling craters of Somma and Rocea Monfina are almost identical, namely, leucitic basalts and the tuffs derived from them; but it is clear that while in the former the lavas form a very large proportion of the mass, in the latter they are quite subordinate to the tuffs, of which the volcano is mainly built up. In the centre of each of these old craters rises a more modern volcanic cone, but of very different characters in the two cases. While Vesuvius is composed of lavas and tuffs quite similar in character to those of Somma, the Montagna di Santa-Croce, which has risen in the midst of the old crater of Rocca Monfina, consists of vast hummocky masses of a peculiar rock—a “trachy-dolerite,” with much mica. That the crater-ring of Corti- nella (which embraces the mountain produced by later eruptions, in the same manner that Somma does Vesuvius) was formed by similar explosive action to that which we know gave origin to the latter, no one can doubt who observes the exact correspondence in all the characters of the two mountains. The only difference be- tween them is this—that while Somma, after the great paroxysm which destroyed all the higher and central portions of its mass, con- tinued to pour forth those similar leucitic lavas and tuffs by which the modern cone of Vesuvius was gradually built up, Rocca Monfina, by a change not uncommonly witnessed at centres of volcanic out- bursts, began to originate materials of a different composition and mode of behaviour, namely, the more acid lavas of much less perfect liquidity which formed those great bosses in the centre of its crater constituting the mountain-masses of Santa-Croce. Proceeding still to the northwards, we find, a little to the south of Rome, a third volcanic group, that of Monte d’Albano, composed. of similar leucitic basalts and tuffs to those of Vesuvius and Rocca Monfina. In the centre rises Monte Cavo, which we may justly compare to Vesuvius; it is a volcanic cone, with a well-marked crater at its summit, upon the floor of which rise the remains of several smaller cones, now weathered down and grass-grown. Monte Cavo, like Vesuvius, is embraced by a great crater-ring, broken away on its western side by the later parasitical eruptions which have origin- ated the craters of Vallariccia, Lago d’Albano, Lago di Nemi, and the craters about Frascati. But while the outer crater-ring of Somma has an internal diameter of only two miles and a half, and that of J. W. Judd—On Volcanos. 301 Rocca Monfina of three miles, the similar crater-ring of Monte Al- bano is not less than six miles in internal diameter; and it is, more- over, almost wholly composed of volcanic tuffs. In spite, however, of the difference of size, no geological observer can for a moment doubt that the exact identity of relation between Vesuvius and Monte Cavo, and their respective encircling crater-rings, points to a simi- larity in their mode of origin; and of what that was in the case of the former we have actually historical evidence. North of Rome rises another volcanic group—that of the Lago di Bracciano. In this case we find a great circular hollow of almost precisely the same dimensions as that of Monte Albano, and composed of identical materials, namely, leucitic tuffs, with a few currents of lava. The circular mountain group that incloses the Lago di Bracciano only differs from that at Albano in the circumstance that no central mountain rises in its midst. The great hollow occupied by the Lago di Bracciano is nearly circular in form, and about 64 miles in diameter. The surface of the lake is 540 feet above the level of the sea; while the highest point of its surrounding wall, the hill known as the Rocca Romana, rises to a further height of 1,486 feet. On its western side the inclosing ring of hills has been cut through by the River Arrone, which affords an outlet for the waters of the lake. It appears clear that the excavation of this river valley has effected a gradual lowering of the level of the Lago di Bracciano, in a manner similar to what was suddenly effected, by artificial means, in the case of the lakes of Albano and Nemi by the ancient Romans. A few scattered outbursts of the volcanic forces have evidently taken place in the immediate neighbourhood since the grand catastrophe by which the vast crater was formed; and numerous hot and mineral springs all around bear witness to the fact that the igneous forces are not even yet wholly extinct beneath it. The Lago di Bolsena is less perfectly circular in form than the Lago di Bracciano ; its length from north to south is 10} miles, and its breadth from east to west nine miles. The lake lies in the midst of a group of hills, wholly composed of volcanic rocks, which rise gradually from the plains to heights of from 1,200 to 1,500 feet above the sea. The surface of the waters of the lake is 962 feet above the level of the Mediterranean, and the ring of hills around it constitute heights for the most part from 300 to 500 feet above it. Some few points in this crater-ring are, however, of considerably greater elevation, as San Lorenzo on the north, Valentano on the south, and Montefiascone on the south-east, which are respectively at heights of 684, 780, and 985 feet above the level of the waters of the lake. The last-mentioned point, however, owes its great elevation to a later eruption, the town being built on the summit of a cinder- cone which has been thrown up on the very edge of the crater-ring, evidently at a period subsequent to its formation. Like that of Bracciano, the crater-ring of Bolsena is cut through by a river- valley. that of the Marta, which affords a means of escape for its waters on its south-western side; and it is clear that by the exca- vation of this channel the surface of the lake has been gradually lowered. 352 J. W. Judd—On Volcanos. The lake of Bolsena differs from that of Bracciano in having two islands, known as Bisentina and Martana, rising in its midst. These are composed of volcanic tuffs, and present the peculiar quaquaversal dips so characteristic of cinder-cones. These are evidently the re- mains of two small cones, which have been thrown up on the floor of the great crater, by eruptions subsequent to the great paroxysm which produced its main features. The series of craters which we have now described possess so many features in common that it is very instructive to notice such points of difference as exist between them, since these may serve to illustrate the various changes, both in the nature and products of their action, which volcanic centres may undergo. In Somma we find a crater with a diameter of two miles and a half, the actual formation of which is described by historians ; while the materials ejected in the course of its production still lie thickly over the ruins of buried cities. Within this crater a cone— that of Vesuvius—-has grown up, and has been in great part destroyed and re-formed several times during the last eighteen centuries. In Rocca Monfina a crater-ring of almost identical character, but of somewhat larger dimensions and older date, has had extruded within its area bosses of bulky crystalline rock, apparently of so viscid a character at the time of their emission as not to be capable of being scattered in scoriz, or of flowing in lava-streams. To pass from these craters to those of Monte Albano and the Lago di Bracciano (of which the diameter is almost twice as great) may at first sight, perhaps, present some difficulty ; but if the exact correspondence of all the features, except those of size, between Somma and Vesuvius on the one hand, and the outer ring and central cone and crater of Monte Albano on the other hand, be considered, no one can possibly doubt the similarity of their modes of origin. The contrast is sufficiently obvious between what must have occurred in the case of the latter volcanic group, where a central cone of vast dimensions has been built up by eruptions subsequent to the grand paroxysmal outburst that gave origin to the outer crater-ring and in that of the vent of Bracciano, which became quite extinct after its final grand effort. In the Lago di Bolsena a paroxysm, of such violence as to produce even a still larger crater, was followed by feebler out- bursts, that only sufficed to form two small cinder-cones within its vast circuit. It is not surprising that the vast size of these great lakes of Bracciano and Bolsena should have led some to entertain doubts as to the possibility of their having been formed in the same way as ordinary craters—that is, by explosion. But if a sufficiently large series of these objects be studied, it will, we think, be found im- possible to draw any clear line of distinction between those of the most moderate dimensions and those which attain such vast pro- portions, or to ascribe to the latter any different mode of origin to that which has so clearly produced the former. Without passing beyond the district with which we are now im- mediately concerned, the truth of this statement may be made clearly J. W. Judd—On Volcanos. 358 apparent. In the Campi Phlegrzi we have several beautiful examples of crater-lakes, such as Agnanoand Avernus. Both of these are less than one mile in diameter, and there is no more room for doubting their mode of origin than there is for questioning that of Astroni, which is a crater with a very small lake in its midst, or indeed of that of Monte Nuovo, the formation of which was actually witnessed only three centuries andahalfago. But in the immediate proximity of these are the precisely similar crater-rings of Pianura and the Piano di Quarto, which, although having diameters of three and four miles respectively, are nevertheless so precisely similar in character that it is quite impossible to assign to them a different mode of origin. Again, the formation of the crater-ring of Somma is an event of which we have authentic records, and it is impossible to doubt that an eruption on even a still grander scale must have originated the precisely similar crater surrounding Monte Albano; while, if this be admitted, the analogous crater-rings of Bracciano and Bolsena cannot but be assigned to the operation of similar causes. Indeed of the recent formation of a crater of even as vast dimensions as those which we have described as existing in Italy, we have an example in the grand eruption of Papaudayang, in Java, in 1772, by which a gulph no less than fifteen miles long by six broad was originated ! Accepting then the conclusion that even the vast circular lakes of the Italian peninsula have been formed by explosive outbursts, similar in character to, but of greater intensity or duration than some of those which have been recorded during the short periods to which history or tradition goes back, we may proceed to ask, what are the causes which have led to the production in different cases of very dissimilar structures by the same explosive action ?—namely, of cones like Monte | Nuovo and Hina, on the one hand, having comparatively small craters at their summits, and of vast craters like the Piano di Quarto and the Lago di Bolsena, in which the surrounding wall is of comparatively insignificant bulk and elevation. In making this distinction, how- ever, it must be borne in mind that no strong line of demarcation exists between the two classes of objects. Between almost perfect volcanic cones, exhibiting at their summits quite insignificant craters and pit-craters with scarcely a vestige of a crater-wall, examples illustrating every conceivable stage of gradation may be cited. It is clear that, as a general rule, the formation of volcanic cones must be assigned to the operations of comparatively moderate ex- plosive force, either long continued or oft repeated; while that of pit-craters must be due to comparatively short, sudden, and violent outbursts. That the cause which produces both classes of volcanic vents is no other than the expansive force of bodies of steam, which are disen- gaged from masses of incandescent lava rising through fissures towards the surface, is a fact now universally recognized. And to the geologist familiar with the appearances presented by such fissures, as filled with the now consolidated materials to which they gave passage, and exposed beneath what were once eruptive vents, DECADE II,—VOL. II.—NO. VIII. 23 304 J. W. Judd—On Volcanos. through the removal by denudation of the overlying volcanic structures, a cause for the varying modes of action at different points of the same volcanic district may readily suggest itself. The great fissures filled with consolidated materials, which pene- trate older rocks in volcanic areas that have suffered great denudation, affect two very distinct modes of arrangement. They are either cracks which traverse the strata vertically, or fissures which have been formed through the yielding of the planes of least resistance among the strata themselves. The former, filled with consolidated lava, become dykes ; the latter, intrusive sheets. That the fissures of both classes sometimes reached the surface, and that, in such cases, they gave origin to volcanic outbursts, we have very unmistakeable evidence. But it is also clear that the action which would take place at the surface in the case of the two kinds of fissures would necessarily be very different. In the case of a vertical fissure, the smallest communication with the surface would lead to alocal disengagement of vapour, and this relieving the pressure on the mass below, continually fresh supplies of steam would be liberated, carry- ing up fragments of the liquefied rock in which it was imprisoned as scoriz or pumice, or forcing it out in streams as lava. Thus would naturally be built up, according to circumstances, a cone of cinders, a composite cone of cinders and lava, or a solid cone (‘‘ mamelon”’), wholly formed by the welling out of the latter material. But in the cease of a horizontal fissure, the result would probably be very differ- ent. Here the mass of lava, which, as we know, may be forced for many miles away from the volcanic centre, would have its im- prisoned water retained by the superincumbent rocks till it reached a point at which, either from a decrease in the thickness or a diminution in the capacity for withstanding expansive force of the superincumbent rock, it began to be disengaged. Then an accumulation of vapour of the highest tension would begin to take place, and by its accumulated force, the repressive power of the overlying rocks being at last com- pletely overcome, the latter, throughout a wide area, would be shattered to fragments and dissipated in one short, sudden, and violent outburst. But the mass of lava to which this outburst was due, having beneath it no further reservoir from which steam could be disengaged and rise to the surface, the first violent outburst would not be succeeded, as in the case of vertical fissures, by a series of similar explosions. By the liberation of vapour in vertical and horizontal fissures re- spectively, then, it seems possible to account for the formation in the same district, as in the Campi Phlegraxi, of the two very distinct kinds of volcanic vents, or for the appearance of either class almost alone, as in the Hifel and the Auvergne. But though this explanation may suffice to account for the production of those smaller vents which occur in such areas as we have referred to, yet it is evident that the formation of enormous craters like those of Bracciano and Bolsena is a problem of a different and perhaps far more difficult character. If, for example, we were to conceive of an eruption of so violent a J. W. Judd—On Volcanos. 355 character as to blow into the air all the central portion of Etna, so as to leave a crater of many miles in diameter, the result would be not very different from the vast lake surrounded by a rim of comparatively small elevation, which we witness in Bracciano and Bolsena. But here we are met by the fact that, in Italy, at least within the historic period, no such mountain as Etna has ever been so destroyed by a volcanic outburst as to leave only a basal wreck consisting of a wide and low crater-ring. Etna is an admirable type of a well-built volcano. As shown in the splendid section of the Val del Bove, lava-streams, dykes, and agglomerates are combined together into a framework of the most solid character. As the structure has risen in height, the weakest portions of its flanks have successively yielded to the vast expansive forces below, and fissures being produced, these weakest parts have been successively repaired and strengthened, first by the injection and consolidation of lava in the fissures, and secondly by the piling up of materials above them. Thus the grand cone has grown, by the alternate strengthening of its flanks through lateral outbursts, and the renewal of ejections from its axial crater, as the vast chimney became sufficiently strong to sustain the pressure necessary to raise the materials to the lofty summit of the mountain. That this has really been the process of growth in Etna, no one who studies its enormous bulk, its numerous parasitical cones, and its clear sections, can for one moment doubt. But as we have already pointed out, the wide and little elevated erater-rings of Albano, Bracciano and Bolsena present a totally dif- ferent kind of architecture to the solid structure of Htna. They are in fact almost wholly built up of loose tuffs; masses of solid lava, whether in currents or dykes, being few, and forming but a very small proportion of their bulk. The action of expansive forces within cones almost wholly com- posed of such loose materials would necessarily be very different from that which we have seen takes place in Etna. Lateral eruptions would become almost impossible, for as soon as any part of the flanks of the mountain began to yield to the rending force, the loose materials at the sides of the fissure would close in and fill the crack as rapidly as it was formed. That this is no hypothetical explanation of what takes place in such tuff cones is shown by the numerous beautiful pseudo-dykes, filled with fragmentary materials, which occur in the tuff-cones of the Campi Phlegreei, and the almost total absence in these cones of dykes of solid lava. The expansive force of the vapour, gradually separated from the incandescent masses of lava below the mountain, being thus unable to open any safety-valve by producing a lateral eruption, would at last attain such tension as to enable it to dissipate the whole structure of the cone itself, composed as it is of loose and uncompacted materials. These by repeated ejection would be reduced to fine fragments, which would be deposited as tuff and ash over enormous areas all around the vents. The craters of Albano, Bracciano, and Bolsena are in fact pemeided by such deposits, which extend over a wide district around them. 356 J. G. Goodchild—On Glacial Erosion. Vast, then, as are the dimensions of the great crater-lakes of Cen- tral Italy, it is impossible to doubt that they have been formed by the same causes which have originated the numerous others of smaller size, but of similar character, within the same district,—namely, the explosive action of steam disengaged from masses of lava below them. Nor does it, in the case of these vast craters, seem possible to admit of their areas having been enlarged subsequently to their formation by any kind of erosive action. Not only is there no evidence whatever that these craters have been submerged beneath the ocean; but, on the contrary, the narrow rivers and valleys by means of which the waters of both Bolsena and Bracciano are carried off, as well as the loose cinder cones in the midst of the former, point to an exactly op- posite conclusion. Neither does the action which Mr. Brigham points out as taking place within that vast lake of liquefied rock, Kilauea, namely, the encroachments of the mass of incandescent liquid upon its walls, by which these are slowly eaten back, appear to throw any light upon the formation of the great Italian craters; so very different in composition and behaviour are the lavas of Italy and Hawaii respect- ively. All theories of an engulphment of the central masses of the volcano completely fail to explain the regular circular form of these depressions, and their striking similarity to those of smaller size, which have evidently been produced by explosive action. Nor, when we reflect on the small portion of the earth’s surface, and the very short periods concerning which we have any records of the nature and results of the physical changes that have taken place upon it, need we hesitate to admit that paroxysms may have occurred which, though similar in kind, yet exceeded in their degree of intensity any which man may have had an opportunity of witnessing or re-. cording. IV.—Guaciat Hroston. By J. G. Goopeuitp, F.G:S. ; Of H. M. Geological Survey of England and Wales. (Concluded from page 328.) Any one who compares the terraces that are shaped by rivers and the sea with the terraces that are found in the Yorkshire Dales must see that in the one case the denuding agent has acted alike upon beds of all degrees of hardness, and has shorn off the edges of the rocks to one level, whether the strata were horizontal or inclined ; in the other case the denuding agent has acted unequally upon the rocks according to their varying powers of resistance, so that the harder beds were left in relief; and, so far from being all shorn off to one level, it would perhaps be difficult to find any one of the Dale District terraces that is not more or less inclined. The bases of the cliffs formed by the one denuding agent are quite level: those left by the other are often inclined many degrees. It will perhaps be remarked that the peculiarities of the Dale terraces are just what one ought to expect if they are the result of J. G. Goodchild—On Glacial Erosion. Soe Subaerial Denudation. Even where there is no stream to remove the weathered material as fast as it falls, some geologists would probably consider the combined action of springs and the weather quite sufficient to give rise to the features in question. But in the par- ticular district here referred to there seems to be evidence to prove that this view is incorrect. It will perhaps be sufficient to refer to the following points in confirmation of this. Wherever springs are found in such a series of alternations of beds of different lithological character as forms the hills of the Dale District, they usually occur at irregular and often at distant intervals along the bases of the more permeable beds. In most cases, especially in the lower beds, the springs issue at the line of junction of a limestone with the more or less impervious bed that it lies upon. Most of the spring water thus thrown out has usually flowed only a short distance under ground ; in the generality of cases the water that flows over the surface of the usually impervious bed above sinks as soon as it reaches the open joints of the limestone and collects over the next impervious bed beneath, by which it is again thrown out to the day. Thus it follows that, where little water finds its way on to the limestone, as little is thrown out as springs; but where the limestone is near the edge of a considerable flat, especially if there is also a peat moss near, springs of considerable size make their appearance. The steep slopes of the fell-sides in the dales usually prevent the wide spreading of any great quantity of water, which for the most part finds its way to a lower level without forming many springs in its course; but high up on the fell-sides, near where the flatter surface begins to be covered with peat mosses, the greater part of the water that comes down the fell-sides issues from the springs. that are found along the base of the highest thick bed of limestone. In other words, at low levels there are found but few springs, and those only small: while in the higher parts the springs are both numerous and of compara- tively large volume. When we compare the forms of the scars in the two places, it is at once apparent that where there are but few springs, that is to say, in the low ground, the characteristic sweeping outline and general uniformity of character of the scars, is retained; while where there are many springs, as in the higher parts, the wide and irregular notches that break the regularity of the scar’s outline, and the accumulation of fallen blocks that have been undermined, plainly indicate that the springs are slowly destroying the present regularity and replacing it by a form of surface altogether different. To put this in another form:—where there are no springs we get the most perfect outline and a surface without much fallen rock: where there are many springs the rock features present a broken and irregular outline, and the slopes beneath are encumbered with the rock thus degraded. Again, the springs do not come out at regular or at close intervals, but are confined to certain positions that are usually determined by either the lie of the rocks or the general direction of the streams whence most of the water is derived. To produce anything like the regularity of form that one sees in the scars, the springs must have acted at regular and close intervals all 308 J. G. Goodchild—On Glacial Erosion. along the line ; and each must also have accomplished only a certain definite amount of cutting back before its position again changed. Even granting that it is possible for springs to cut back an escarp- ment with a certain total amount of regularity, it is clear that, unless there are at hand larger streams to remove the undermined rock, the springs would soon become so much choked up that their action would no longer be effectual. In other words, if the rate of removal do not keep pace with the rate of disintegration, the accumulating talus would soon protect that part of the scar from much further alteration. Another objection to the spring theory is that nearly all the denudation effected by the springs would be confined to beds above the impervious bed that throws them out; hence, if the lime- stone scars are really the result of spring action, we ought to find the limestone scar in all cases at a considerable distance nearer the centre of the hill than the outcropping edge of the sandstone that . forms its base. Instead of this, we find, in nearly every case but that where the limestone directly overlies a soft bed, that the lime- stone scar forms part of one continuous slope with the outcrop of the sandstone beneath. Hence the conclusion seems inevitable that both scars were formed at the same time and by the same agencies. Lastly, some of the terraces whose origin is here discussed have a width of two hundred or three hundred yards, or even more than that ; yet the outer part of the terrace, that is to say, the part nearest the marginal scar, usually exhibits no greater amount of weathering than does the innermost part close to where the next bed above comes on. If then the terraces have really been produced by Sub- aerial Hrosion acting unequally upon beds of different degrees of destructibility, it follows either that the overlying shales have been cut back from the limestone at a greater rate than we have evidence for ; or else, if the time occupied in cutting them back has been long, the weather has no appreciable effect upon the limestone after this has undergone a certain amount of subaerial erosion. Yet there is clear proof that, under circumstances the most favourable, so soft a rock as shale has rarely been cut back far in Post-Glacial times; therefore it is clearly impossible that a much larger quantity can have been removed in the same time in situations where no stream could possibly flow under anything like the present physical con- ditions. The alternative that after a time the limestone ceases to undergo any further erosion needs no other argument to disprove it than that afforded by the position and shape of the swallow-holes. Under subaerial conditions the streams that gave rise to the swallow- holes must be continually cutting back the soft beds overlying the limestone from the point where the stream first reached the limestone towards the watershed. Consequently, the swallow-holes that were first formed would either remain in their original shape and position to mark where the stream first began to sink, or else would tend to lengthen in the direction of the source of the stream, as the point where this first reached the limestone slowly receded towards the watershed.. Hence the swallow-holes, instead of retaining a rudely circular form, would change first into the form J. G. Goodchild—On Glacial Erosion. 359 of an ellipse, and then gradually become longer, until they extended from the point where they were initiated right across the terrace to the very inner margin. If the rate of recession of the scar at the edge of the terrace were equal to that of the overlying bank of shale, the first formed swallow-holes would soon be cut back too, and we should then find a series of ravines extending across the whole width of the terrace. It need hardly be repeated that nothing of the kind is to be found in the part of the Dale District here referred to: perhaps it would be difficult to find a single instance of such a series of ravine-like swallow-holes in the entire Dale District. Now it is clear, as was pointed out above, that the existence of these terraces has been determined, not by the capacity of the rocks that form them to resist subaerial erosion, but by their relative powers of resistance to erosion by mechanical means. Bearing these facts in mind, and reflecting upon the regular forms of the scars; their parallelism with others above and below; their frequent correspondence in form with others on the same horizon across valleys a mile or more in width; the existence of perfect scars and terraces many hundreds of feet above where, under existing physical conditions, it would be possible for any stream to produce them; the uniformly weathered surface of the limestone and the restriction of the principal swallow-holes to the inner margin of each terrace; the general absence of much debris from the higher beds ; and, finally, the existence of glacial markings close to the inner margins of some of the widest terraces — we may well hesitate to accept any theory whereby the origin of these characteristic rock features is referred to Subaerial Erosion. At least as early as the summer of 1868 Prof. Hughes, when we were together surveying part of the district referred to, expressed a doubt whether any one of the Subaerial Denudation theories was adequate to account for all the facts connected with the rock features of that district; at the same time he stated his belief that no small share in the development of the surface characteristics of the Dale Rocks must be attributed to the action of land-ice. Since then an increasing acquaintance with the physiography of a large area of the Upper Paleozoic rocks adjoining the Dale District has increased my conviction that the theory put forward by Prof. Hughes is the only one that really sorts with the facts. In the communication referred to at the head of this paper I have stated my reasons for believing the former existence in the Dale District of an ice-sheet of such a thickness that it overtopped the highest fells; therefore its surface could not have been much less than 2300 feet above the level of the sea. Nearly everywhere at high levels the ice seems to have flowed away from certain pretty well defined lines and centres without being much influenced by the form of the underlying low ground; while in proportion to its nearness to the bottoms of the valleys it seems in general to have been more and more guided by the configuration of the adjoin- ing surface, in the manner so often spoken of by Prof. Ramsay. 360 ‘el . G. Goodchild—On Glacial Erosion. The flow of the higher strata of the ice seems to have been mainly guided by the position of the adjoining higher fell tops, while the lower strata seem to have been guided in their course by the sides of the old preglacial valleys and to have flowed steadily outwards nearly like a modern glacier. Whatever difference of opinion there may be. amongst geologists with regard to the theory that I have elsewhere put forward, that the great ice-sheet was charged with detritus throughout, there can hardly be any with regard to the existence of stones between the ice and the rock surface that it covered. It must be borne in mind that when the Glacial Period set in the ice must have had to work at a surface that had been exposed for ages to the attacks of subaerial forces, and that, in consequence, all the rocks were weathered to a great depth. What that depth was has never yet been determined ; but, if we may judge by the rapid rate which many rocks weather in a single lifetime, we should be prepared to find that the amount of weathering effected between the close of the next older Glacial Period and the commencement of the latest was far in excess of anything of the kind that we can now point to in these islands. I have long held the opinion that it was this preglacially-weathered rock that formed the bulk of the materials of the drift. When, therefore, the early glaciers began to invade the lower parts of the valleys, the removal of the surface rock, loosened as it was by long-continued weathering, must have been a comparatively easy matter. At the outset, on account of the deeply-weathered joints in the harder kinds of rock, their rates of erosion would be nearly equal. But as soon as the weathered outer portions of the limestones and sandstones were removed, the unweathered rock beneath would be better able to withstand the grinding of the ice than would the associated softer flags and shales. As a consequence, the softer beds were eroded much faster than the interbedded harder rocks, which would thus be left in relief as terraces. The remarkable capability of the ice to adapt itself to every form of the surface, which the glaciated surfaces of the North of England plainly show the ice must have possessed, must have helped greatly to produce such a result. Wherever the ice passed over a soft bed that had one much harder immediately beneath it, the overlying bed was removed with com- parative ease; while the newly bared upper surface of the harder rock beneath offered much greater resistance to the grinding of the ice and consequently suffered much less erosion. In the case of some of the more compact and thickly-bedded rocks, it seems that the highest strata of the hard bed even yet form the upper surface of the terrace a hundred yards or more from the outcrop of the overlying soft bed. In connexion with this part of the subject there is one point that seems to have been overlooked by many of those who have written about the vertical limit of the ice-sheet. It has been assumed, seemingly upon insufficient grounds, that the rough and craggy form of the higher parts of districts that are well glaciated in their valieys is good proof that these higher parts were never overridden by the J. G. Goodchild—On Glacial Erosion. 361 ice. But if the view here advanced be correct—that the ice removed from the low ground all the weathered parts of the rock—it follows that, because the stay of the ice at the higher points was brief as com- pared with its stay lower down, much less of the high lying weathered rock was removed; and consequently, when the whole surface became again exposed to the action of subaerial agencies, the sound rock of the low grounds would be long in being affected, even where it was not covered by drift, while at the higher points subaerial denudation would soon remove the slightly glaciated surface and replace it by another that would appear to have been always out of the reach of the ice. Thus it is that in the Dale District the higher lying rock surfaces show more decided traces of the action of the weather than are to be found nearer the bottoms of the valleys. The thorough glaciation of the low ground caused all the preglacially weathered rock—swallow-holes, widened joints, and all—to be re- moved; whilst at higher levels even a considerable portion of the preglacially weathered rock was left. In the one case the weather has had to begin its work anew; in the other it resumed work almost where it ceased. The same remarks will of course apply equally to those parts of Mid and Southern England where the presence of glacial drift marks the former extension of the ice-sheet. When compared with its duration in the Northern parts of England, the stay of the ice-sheet in the South was probably brief. Hence there would be less modification of the rock surface than was effected where the ice had a longer stay. Consequently, the slight amount of erosion that the rocks underwent would favour the rapid replacement of an ice-worn surface by one that to all appearance had been produced solely by atmospheric causes. With regard to the quantity of rock removed from parts that had long been exposed to glacial action, there does not seem anywhere to be any satisfactory evidence. But when we reflect upon the immense numbers of the boulders of almost every rock of marked lithological character that have been dispersed far and wide from outcrops of small extent, it is at once apparent that other rocks that, as boulders, are not so easily followed, have, under a like amount of glaciation, suffered denudation to as great an extent. The well- known granite of Shap is a familiar instance. From a superficial area of about a square mile and a half, lying just to the north of the Lake District Watershed, and in such a position as to be long out of reach of the ice, immense numbers of blocks have been dispersed in an easterly direction from the Fell itself, over Stainmore, and far and wide over the country to the Hast at least as far as the North Sea; while, owing to the southern overflow of this part of the Eden Valley ice consequent upon the inflow from Scotland, great numbers of the same boulders have been carried backward in the higher parts of the ice, over the watershedding line, and away South by Lancaster, Preston, and Chester, at least as far as the Vale of Gloucester. What is true of any one rock therefore, must, under lke circum- stances, be equally true of those that it is associated with ; from this it seems a fair inference that the quantity of rock removed from the 362 Dr. Walter Flight—History of Meteorites. surface of the lower lying Dale rocks must be at least equal, area for area, to what was removed from Wastdale Crag. Hence we are led to the conclusion that the ice-sheet effected some very important modifications of form in the old preglacial valleys. Where the ice remained for long periods, there can hardly be any doubt that many of the valleys were both deepened and widened, in some instances to a considerable extent; and also that the peculiar mode of action of the ice tended everywhere to modify the pre-existing form of the surface and even to replace part of this by sculpturing that is very different from anything that, under existing physical conditions, could possibly be produced by any kind of Subaerial Erosion. The origin of these terraces and scars of limestone has, perhaps, been dwelt upon here at greater length than its importance might at first seem to require, because the existence of such features in a rock so easily affected by atmospheric agencies as limestone is affords us a clear proof that whatever left them in so high relief beyond the associated less-easily weathered beds was an agent that acted with greatest effect upon those rocks that could least withstand mechanical erosion and disregarded their varying power of resistance to erosion by Subaerial means. We know that the valleys where these features occur were at one time filled to the highest points with ice; we also know by the position of certain marks of glacial origin that but little atmospheric erosion has been effected at those points in Post-glacial times; hence the conclusion seems inevitable that all the rock features whose origin cannot be referred to any form of Subaerial erosion, but which are clearly due to erosion by some mechanical means, have been the work of the ice. Not only the terraces of limestone, but the asso- ciated terraces and scars of sandstone and grit, must have originated in the same way. Hence one is led to regard nearly all the more prominent rock features of these well-glaciated parts as in one way or another the result of Glacial Erosion. _ V.—A CHAPTER IN THE History or METEORITES. By Water Fuicut, D.Sc., F.G.S., Of the Department of Mineralogy, British Museum. (Continued from page 320.) 1790, July 24th.—Barbotan and Roquefort, Landes, France.! A correspondent communicated to Nature a reference to a descrip- tion of this celebrated fall of meteorites, which is to be found in Gruithuisen’s Naturgeschichte des gestirnten Himmels 407. As it does not appear to have been known to Buchner, it may be placed on record here. 1803, April 26th_L’Aigle, Orne, France.’ While at the end of the last century reports from time to time obtained circulation, to the effect that stones had been seen to fall from the sky, and while these reports were generally discredited as 1 Nature. February 1st, 1872. 2 KE. H. von Baumhauer, Archives Néerlandaises, 1872, vii. 154. Dr. Walter Flight—History of Meteorites. 363 fabulous, a desire had arisen among the curious to collect and preserve them, and even to submit to careful study these strange mineral masses, to which an atmospheric origin was attributed. It was at this time that Howard and De Bournon made a careful examination of the stones reputed to have fallen from the sky, which were con- tained in the mineral collection of Greville; and, after observing them to possess certain characters in common, as well as others which distinguished them from terrestrial matter, they were led, in the Philo- sophical Transactions of 1802, to give their support to the views, then regarded as purely fantastic, which Chladni had propounded in 1794 in his remarkable memoir Ueber den Ursprung der von Pailas und anderer ihr dhnlicher Hisenmassen. The new view had in fact found little favour among scientific men, especially in France, and De Bour- non and the French savant Patrin were engaged in a controversy on the subject at the beginning of 1803, when the celebrated fall at L’Aigle, of from two to three thousand stones, took place. The first news which reached Paris was received with a smile of incredulity ; the illustrious Biot, however, was deputed by the Ministre de ('In- térieur to proceed to L’Aigle and institute a full inquiry, which lasted many days ; and his exhaustive report, which appeared in the Memoires de la classe des Sciences math. et phys. de Institut national de France, finally set the question at rest, and established the fact that the stones were of cosmical origin, and the truth of Chladni’s theory. These meteorites were analysed by Thénard, who found in them silica, iron oxide, magnesia, nickel, and sulphur, amounting in all to 108 per cent. ; and afterwards by Fourcroy and Vauquelin, who de- tected the presence of the same ingredients and lime in addition, the total amounting to 104 per cent. The excess of course was due to the fact of the metal present as such in the meteorite being accounted oxide in their calculation. In consideration of the past historical importance of this fall, it occurred to von Baumhauer to submit the L’Aigle meteorite to analy- sis by the new and elegant methods which he has devised and em- ployed with so much success on other meteorites. His results are given below. The specific gravity of the stone is 38-607, and the total composition is as follows :— Nickel iron Aer est ete nse coeat ans Picnctcesanuenncesleasonece ooadcdodeaqG0 Non gg. GHD) Iron sulphide ........ psn ssannndcodsch eadasononadaaqaqcHsNRboDeRE.aeD cocneODId 200006 1:8 GT OMMU aeaee a seausetn See oceee oe facmaee eochate wens cauauge=suewesncritceescee sce 0:6 Olnvan er -22s. J uaccunckcesesasccess na -ooonognosbeNocoNNICEs0N0 a0 padoccace9e0d000000 45:3 NilieateramactedyupOUpyaacid Weee-ccrecssctecnecsn-snreenacsescececrqrnee ox 44-3 Lime sulphate...........00000 Bea ctaseceneniecnchedue drnstesieccssackintesereccess trace 100:00 After the removal of the nickel-iron, the treatment with acid and sodium carbonate brought about a separation of the varieties of sili- cates, which had the following composition :— Sid, FeO MnO Al,0,; Ca0 MgO K,O Na,O A. Soluble ...... 35°16 30°39 trace 0°18 6:16 26:51 0°85 0:75 B. Insoluble ... 57:16 12°56 trace 519 4:08 17-91 2:02 1:07 100-00 99:99 364 Dr. Walter Flight—Mistory of Meteorites. The oxygen ratios of acid and bases in the soluble part 18°63 : 19:58 show the silicate which gelatinised with acid to be an olivine, re- markable, it should be observed, for the amount of lime it contains. ‘a 1 a Ca 1 SiO, as an expression of its composition. In the insoluble part the oxygen ratio of acid and bases is 80°28 : 14°15, and here the presence of more than five per cent. of alumina points to the probable occurrence of a felspar in this portion of the stone. If we assume that the iron oxide, magnesia, and lime,’ are present as a bronzite, the oxygen ratios of the alumina, alkalies, and residual silica, differ very little from 3:1:9, or those of oligoclase, soda-lime felspar, in some varieties of which a con- siderable proportion of the soda is found replaced by potash. 1808.—Red River, Texas.” As Graham’ has shown that the Lenarto meteoric iron contains 2°85 times its volume of occluded hydrogen, carbonic oxide, and nitrogen, and Mallet (see page 28) has found 3°17 times its volume of hydrogen, carbonic oxide, carbonic acid, and nitrogen occluded in the meteoric iron of Augusta Co., Virginia, it occurred to the author that it might be possible to detect in the gas of these irons the unknown gaseous elements assumed to be present in the solar corona and chromosphere. The investigation was undertaken with the hope that the spectroscope would reveal them, if present, although their small amount or peculiar characters might render their detection by ordinary chemical methods difficult or impossible. A vacuum tube of the form ordinarily employed in spectroscopic work was attached to a branch of the exhaust tube of a Sprengel pump, and a preliminary examination was made of the lines exhibited by this tube after simple withdrawal of the air. As Pliicker and Hittorf* have already shown, lines of hydrogen and bands due to carbon make their appearance as soon as the limit of exhaustion has been attained; the author noticed the red hydrogen line when the tension fell to 4 or 5 mm., and other hydrogen lines when a higher degree of rarefaction was attained. Mercury lines, varying in bright- ness with the temperature of the room, are also to be seen. His in- vestigations were directed to an examination of the gases of the great Texas meteorite, preserved in the Mineral Collection of Yale Col- lege, and the meteoric irons of Tazewell Co. and Arva, Hungary (which see). The iron was in very small particles—chips produced by the borer, and the exhaustion was proceeded with without the application of heat. He noticed that the iron gave off a portion of its gas at ordinary temperatures ; and when the tension was reduced to 4 mm., Ha and Hg were bright and distinct, and Hy visible, while the carbon bands were also distinctly seen. Whena gentle heat was applied, the tube, which had hitherto presented the appearance of an Von Baumhauer gives the formula ( M 1 The bronzite of Harzburg, analysed by Streng, contains lime. 2 A.W. Wright. Amer. Jour. Sc. 1875, ix. 294. 3 T. Graham. Proc. Royal Soc., xv. 502. 4 J. Plicker and W. Hittorf. Phil. Transactions, clv. 1. Dr. Walter Flight—History of Meteorites. 365 ordinary hydrogen tube, underwent a change; the light in the broad portion became a straight, hazy stream, of a dull greenish-white colour, similar to that observed in a tube containing either of the oxides of carbon. When the tube containing the metal was raised to low redness, only a small quantity of gas was given off. Wright did not measure the amount of gas removed by the pump, but has calculated this quantity from an observation of the degree to which 1 ce. of the gas lowered the guage of the instrument. He finds in this way the mixed gases extracted to have occupied 4°75 times the volume of the metal. While this exceeds the quantity which Graham and Mallet noticed in their investigations, the author believes that the whole amount was by no means exhausted, and ascribes the excess to the fact of the metal which he used having been in a fine state of division. 1810.—Brahin, Minsk, Russia. Two large meteoric masses were found at Brahin in the early part of this century; the dates of their discovery are variously given as 1810 and 1820, and they were first described in 1822. They bear the closest analogy to “the Pallas iron” in structure, and with it belong to the small class of siderolites. The Brahin iron was very imperfectly examined by Laugier in 1828, who confined his analysis to that of the iron. Since that time it has not been investigated except in one respect by Rose, who a few years ago noticed that the olivine was traversed by canals, as the Krasnojarsk olivine is (see page 3138, note). Rammelsberg, who has recently examined this siderolite, finds the metallic portion to consist of : Tron = 88:96; Nickel and Cobalt = 11:04. Total = 100. During the half century which has elapsed since Laugier’s time, new and refined methods of analysis have been devised, and Ram- melsberg now finds a per-centage of nickel and cobalt more than four times as great as that given by the original observer. The per-centage is close to that found by Berzelius in the metallic portion of the Krasnojarsk siderolite (11:19 per cent.) ; so that they have a compo- sition closely according with the formula Ni Fe,. The olivine, now analysed for the first time, has the composition : Silicic acid ... coo noo) cco (ENS Tron (manganese) Drotoxide see eee one ©1885 MASNESIA pi iteal. se oeh fesse cos. Yessy Pes tessi Aove2 99-75 These numbers, contrary to expectation, do not agree with those resulting from the analysis of the Pallas olivine ; above we have Fe and Mg in the ratio 1:4; in the Pallas olivine about 1:8. It is nota little remarkable, however, that the Brahin olivine has the same com- position as that of the Atacama siderolite analysed by Schmid, the iron whereof has been shown by Bunsen to contain Nickel=10-25, and Cobalt = 0:70 (see page 77, note). 1 C. Rammelsberg. Monatsber. Ak. Wiss. Berlin, 1870, xx. 440. 366 Dr. Walter Fught—History of Meteorites. 1812, August 5th—Chantonnay, Dép. de la Vendée, France.’ In the winter of 1874 Tschermak published a paper on the structure of the meteorites of Orvinio (see page 222) and Chantonnay, which appear to have many characters in common. Sections of the latter stone, three drawings of which are given in his paper, show it to be made up of chondritic fragments, covered with a dark-coloured crust, and cemented together with a black and in places semi-vitreous material. The fragments are not very abundantly provided with spherules, although large ones are here and there met with. It differs from the chrondrite of the Orvinio meteorite in containing less iron ; a section shows olivine, bronzite, a finely fibrous translucent mineral, as well as nickel-iron and magnetic pyrites; the presence of chromite was not recognized. Fine black veins of a mineral traverse the fragments here and there, and are connected with the cementing material. Similar veins are noticed in the meteorites of Lissa, Kakowa, Chateau Renard, Alessandria, and Pultusk ; and in the Lissa and Kakowa stones they present the appearance as if the meteorite had originally come in contact with a molten material which had been injected into the clefts of its surface. Reichenbach was of opinion that the black veins were directly and intimately con- nected with the fused surface; his view, however, is open to question, from the fact that the interior of a meteorite has usually a low temperature when it reaches the earth’s surface. Moreover, in the case of the Chantonnay stone, clefts are to be met with into which the black matter of the crust has penetrated to a depth of 6 mm. only, although the cleft remains partly open. The black semi- vitreous magma consists of an entirely opaque mass, enclosing flakes of the silicate, which forms the fragments, as well as occasional spherules. Although Rammelsberg, who analysed this stone, does not describe the physical characters of the material he operated on, and did not separately examine the fragments and the cementing material, as Tschermak has done in his examination of the Orvinio meteorite, to find that the two constituents have much the same composition, Tschermak points out that the two meteorites have a very similar constitution, differmg mainly in the proportion of iron. The characters observed in these two meteorites point to the conclusion that they did not originally possess their present constitution, but that to the disintegration of a solid rock-mass and its subsequent cementation with a semi-vitreous magma their present appearance is due. Although they resemble somewhat the eruptive breccias, they differ from them in that the meteoric cementing material is less homogeneous, and encloses fine flakes of the rock itself. The Chan- tonnay stone exhibits the fine texture observed in some metamorphosed breccias. The two stones convey to us evidence of changes which must have occurred on the solid surface of some planet that was subsequently reduced to fragments. 1G. Tschermak. Sitzber. Ak. Wiss. Wien, xx. November Heft, 1874. Dr. Walter Flight—History of Meteorites. 367 1813, September 10th.—Adare, etc., Co. Limerick, Ireland. This meteorite, originally investigated by J. Apjohn,? has been ex- amined by R. Apjohn, who finds that it contains a trace of vana- dium. The date which he assigns to the fall of this stone, 1810, appears to be that of another Irish meteorite, which fell at Moores- fort, Tipperary. The nickel-iron has the composition : Tron =85°120 ; Nickel=14-275 ; Cobalt=0°602; Phosphorus=Trace; =99-997 and the result of the treatment with acid: SiO, Al,03; FeO MnO CaO MgO Na.0 K20 P.O; A. Soluble...... 42°91 2°35 16:93 6°26 5-34 24-32 0:29 0:02 —— = 98°42 B. Insoluble ... 59°48 3-24 7-94 8°84 4°62 13°17 1-86 0°30 trace = 99°45 The mineralogical composition of the stone is stated to be: INMGRGIEMRDA oho) /G50 G50" oto Sho oso aso LOD Chromite eee ce eee e seal wicsap tress eee lado. Magnetic pyrites ... 11. ss. os wee wee «= 64 Soluble silicate. ... 1... 0. seo cee vee 8044 Insoluble silicate ... 10. 0 soe see ee 31:00 99-87 ‘The chromium oxide present as chromite is not mentioned at all in the above analysis. The iron sulphide is probably present as troilite (iron monosulphide), as according to the older analysis the greater part of the sulphur is in the part which is not attracted by the magnet. There the ratio is given as Fe = 3:92, 8 = 2:04; the per-centages for troilite, using the sulphur as the basis for the calculation, would be Fe = 3°57, S = 2:04; and for magnetic pyrites Fe = 3:12, 5S = 2:04. In an obliging letter received from the author he informs me that the amount of vanadium present was too small to allow of a quanti- tative estimation being made. He believes that in amount it is about one-half that met with in the trap-rocks of Ireland and Italy, which have recently been examined by him. He is inclined to the belief that the vanadium is present as an oxide associated with the chromite, “for we know vanadium occurs in terrestrial chrome iron in compara- tively large quantities.” 1814.—Lenarto, near Bartfeld, Saros, Hungary.’ Boussingault, who some time since found nitrogen in this iron, has recently examined it with the view of determining whether it con- tains carbon in a state of combination with the metal. His analysis, given below, did not detect the presence of that element in any form. Tron =91°50 ; Nickel=8-58; Insol. Residue=0°30; Copper=trace. Total=100°38. It was in this meteoric iron, it will be remembered, that Graham made the interesting discovery of the presence of hydrogen condensed 1R. Apjohn. Jowr. Chem. Soc. [2], xii. 104. 2 J. Apjohn. Trans. Irish Acad., xviii. 17. 3 J. Boussingault. Compt. rend. \xxiv. 1287. Ann. Chim. et Phys. xxviii. 124. Chemical News, No. 688, 59.—M. Salet, Revue Scientifique, 1872, March 9th. The Academy, ii. 118. 368 Dr. Walter Flight—History of Meteorites. (occluded) in the substance of the metal. The gas obtained from this iron has been examined spectroscopically by Salet, who communi- cated his results to the Société chimique de Paris on the 1st March, 1872. His researches on the polar aurorae had led him to seek for the yellowish-green ray (\—=557), but he found only those due to the presence of hydrogen and an oxide of carbon. It must be as- sumed then that the carbon present in the iron, and which must be very small in quantity, exists there not as carbide of iron, but as oc- cluded carbonic oxide. 1828.—La Caille, near Grasse, Alpes-Maritimes (formerly Dép. du Var), France.’ Meunier has submitted the Caille iron to an exhaustive examination. He finds, when etched, that it presents much the same appearances as he noticed in the Charcas iron (see page.320) ; it consists of kama- cite (chamasite; H. §. Dana’s “Second Appendix to Dana’s System of Mineralogy,” 11) and tinite in much the same proportions. The tiinite has a specific gravity of 7-380 (von Reichenbach in another meteoric iron found the number 7-428) and the composition :— Tron = 85:0; Nickel (cobalt) = 14:0. Total = 99-0. Tron = 85:0; Nickel (cobalt) = 16:0. Total = 100-0. numbers which indicate the formula Fe,Ni. The kamacite has the specific gravity 7:652, and consists of : Iron = 91:9; Nickel = 7-0. Total = 98:9. which is an alloy of the formula Fe,,Ni. The entire iron appears to contain about 80 per cent. of the latter alloy, and Meunier’s numbers correspond very closely with those obtained by Rivot, who analysed the metal in the bulk. The graphite of this iron, found in the residue after treating the metal with hydrochloric acid, has a density of 1-715, and the compo- sition : Carbon = 97°3; Tron = 2:4; Nickel = trace. Total = 99:7. The troilite of the Caille iron, after treatment with acid, left a small amount of siliceous residue, which was precisely similar in its physical characters to that found in the Charcas meteorite (see page 319). By the action of heat and oxidizing agents figures were developed which likewise bore the closest resemblance to those developed on the Charcas iron. The accompanying woodcut gives a representation of a block of this iron (actual size) which is in the Paris Collection. It shows the Widmannstattian figures, developed by etching with hydrochloric acid, and the reniform hollows which have been filled with troilite. 1S. Meunier. Thése presentée a la Faculté des Sciences de Paris, 1869. Recherches sur la composition et la structure des Meétéorites, 29, et seg. La Nature, i. 292.— J. Boussingault. Compt. rend. lxxiy. 1287. Ann. Chim. et Phys. xxvii. 124. Dr. Walter Flight—History of Meteorites. 369 Jn an examination of this iron, undertaken with the view of deter- mining the presence of combined carbon, Boussingault found it to be composed of :— I, ale TRO J 5ds0 soauedgceds cdocHdéooKGNGges0 600 89°53 89°73 INITIO) | 55 SooneseaqdaoooosdocansoSdecododan 9°76 9:90 Carbon combined \crecscs-ceeeeeooses O12 0:12 Insoluble portion .........sessesseoes 0°59 0°25 Sul phrieeecctaceeneccececser coocaseabec trace trace 100-00 100-00 1828, June 4th.—Richmond, Chesterfield Co., Virginia.’ This meteorite, the chemical characters of which were studied by Shepard, the physical by G. Rose, has recently been found by Rammelsberg to have the following composition : INTE LaTHRON...6 concqaqoabeon09900Nb0Q00N0 400000000000000 8:22 Mong Sul pid @heeseenacesance ss acecscseneachensceacces 4:37 ONT AIRS, 7 35 case concen seaodacoacdohoodeososeondconsemnnaca 45°73 Undecomposed Silicate ............ <..sceescsorcoces 41-68 100-00 . The silicates having been separated by treatment with acid and sodium carbonate were found on analysis to have the composition given below: SiO, AhLO; FeO MeO CaO A. Soluble. 39-40 at 18-21 41-69 0:80 = 100-00 B. Insoluble. 53°74 5°32 13°17 22:23 5°54 = 100-00 In the soluble portion the ratio of Fe to Mg is 1: 4, which shows it to be an olivine identical in composition with that variety of this mineral which has been met with in the siderolites of Brahin and Atacama. The insoluble portion, according to Rammelsberg, is either a bronzite containing lime, or a mixture of that mineral with diopside. Shepard had found this meteorite to be composed of 6 per cent. of nickel-iron, with some magnetic pyrites, and 90 per cent. of olivine, the residue being howardite and lime phosphate. 1835, July 31st, or August Ist. Charlotte, Dickson Co., Tennessee.” The iron, which is found disseminated in small particles through- out the mass of many meteoric stones, represents in miniature the 1C. Rammelsberg. Monatsber. Ak. Wiss. Berlin, 1870, lxx. 440. 2 J. L. Smith. Compt. rend., 1875, Ixxxi. 84. DECADE {1.—VOL. II,—N0O. VIII. 24 370 Dr. Walter Flight—History of Meteorites. huge blocks of meteoric iron that from time to time have been met with on many parts of the earth’s surface, the record of the fall of which is unknown, their descent having probably taken place at an epoch long anterior to that of their discovery. While the stones enclosing iron have not unfrequently been seen to fall, the descent of purely metallic masses has been rarely witnessed. At present we know of only the following few authentic cases: Agram (1751) ; Braunau (1847); Victoria West, S. Africa (1862); and Nidigullam, Madras (1870). To these few instances is to be added the one head- ing this notice, of which a brief account was published by Troost, of Nashville, in 1845.1. The Tennessee iron fell from a cloudless sky, near several persons who were working in the fields. A horse which was harnessed to a plough close by took fright, and ran round the field, dragging the plough with it. The iron has remained in the Troost Collection up to the present time, when it passed into the hands of Dr. Lawrence Smith. It isa reniform mass, and has a bright surface like that of soft cast- iron. When etched it exhibits Widmannstattian figures in great perfection, and the author states that in this respect he is acquainted with only three or four irons which rival it. An illustration ac- companying his paper, closely resembling the one given by Troost, is a representation of the outer surface, magnified ; this is elaborately reticulated, edges of thin lamine of metal, inclined at angles of 60°, traversing the surface, the edges being separated from each other by an apparently semi-fused slag-like material. ‘The specific gravity of the iron is 7-717, and its composition : Tron=91'15 ; Nickel=8-01; Cobalt=0°72; Copper=0-06. Total =99-94. Sulphur is not present, and of phosphorus only a trace was recognized ; and the author states that he has never before met with so small a proportion of this element in a meteoric iron. The gas, extracted from this iron by A. W. Wright, who has recently examined the occluded gases of the irons of Texas, Arva, and Tazewell Co., as well as that of the meteorite of West Liberty, lowa (which see), has nearly twice the volume of the metal operated upon, although this is probably a portion only of that actually present. It is com- posed of: Hydrogen=71-04; Carbonic oxide=15-03 ; Carbonic acid=13-03. Total=100-00. A question of no slight interest in regard to the changes which meteoric irons undergo during their passage through the atmosphere is whether their surface becomes fused. From his study of the Tennessee meteorite, Dr. Smith has decided it in the negative. The fact of the delicate reticulated surface having been preserved is a proof that the heat, instead of having been raised to a high tempera- ture on the surface, has quickly been conducted away into the mass of the metal. Had fusion of the superficial layer taken place, the meteorite would have been coated with molten oxide. The author finds in this fact a confirmation of his theory that the Ovifak masses are not of meteoric origin. 1G, Troost. Amer. Jour. Sc., xlix. 336. Dr. Walter Flight—History of Meteorites. 371 1838, July 22nd.—Montlivault,. Dép. Loir-et-Cher, France." Daubrée gives a brief description of this meteorite, which has recently been acquired for the Paris Collection. It has been pre- served almost entire, and is roughly shaped like a three-sided pyramid. It is finely granular, has a white colour, and weighs 510 grammes. The ground-mass of the stone, consisting apparently of an intimate mixture of olivine with an augitic mineral, encloses small grains of nickel-iron and magnetic pyrites. The meteorite belongs to the group, now a large one, of meteorites to which the name luceite has been given. 1840.—Szlanicza, Arva, Hungary.” For his investigation by means of the spectroscope of the gases occluded by meteoric iron, Wright examined those from the Red River, Texas, and Tazewell Co., Tennessee (which see). The amount of carbon present in the former iron was found on chemical examination to be very small; in the latter none was detected. A series of experiments were therefore made with the above iron, which according to Lowe®* contains a larger amount of carbon. While it was an easy task to remove fragments of the above- mentioned irons, great difficulties were experienced in the present case, the metal having nearly the hardness of steel. When the tube contain- ing fragments of this iron was exhausted, and before heat was applied to it, the spectroscope indicated the presence in the “ vacuum-tube ” of both hydrogen and carbon gases; the lines of the former element were very brilliant, and the first, second, and third bands of the latter, counting from the red end, were visible. The application of a heat hardly sufficient to pain the hand caused an entire change in the ap- pearance of the vacuum-tube; the broad part took a greenish hue, while in the spectroscope the carbon bands shone quite brightly. When the heat was raised to a temperature considerably short of redness, the only change noticed in the spectrum was a greater intensity of the carbon bands; the gas collected at this stage of the operation was found on analysis to consist of hydrogen, carbonic oxide, and carbonic acid, the latter amounting to three or four per cent. In some experiments on artificial soft iron the author obtained a spectrum in every way similar to that of the meteoric metals; the hydrogen lines, however, did not appear so early, nor were they so bright as in the latter instances. The iron of this meteorite, which by its great hardness was separated in the state of fine powder, yielded, when heated at dif- ferent temperatures up to low redness, 44 times its volume of gas. While it seems not improbable that some portion of what has been regarded as occluded gas may have been air, the yield isso unusually large that it suggests the question, May not the more perfect removal 1G. A. Daubrée. Compt. rend. 1873, 10th Feb. Der Naturforscher, 1873, 26th April. 2A. W. Wright. Amer. Jour. Se. 1875, ix. 294. 3 A. Lowe. Amer. Jour. Se. [2], viii. 439. 372 Walter Keeping—Neocomian Sands at Brickhill, Beds. of the gas from the iron be due to the fine state of division of the metal operated upon? In the case of the Texas and Tazewell irons, where the yield of gas exceeded that obtained from the Lenarto and Augusta Co. irons, the metal was in very small pieces, which would favour a more rapid and complete evolution of the gas; in the last- mentioned instances they were en bloc. That iron may under certain conditions, as when deposited by electrolysis, take up nearly two hundred and fifty times its volume, has been shown by the recent re- searches of Cailletet.1 An observation recently made has a bearing on this question. While analysing a specimen of silver amalgam, I endeavoured to remove the mercury from a weighed fragment of the mineral by heating the specimen in a hard glass tube, during more than five minutes in the flame of the table blowpipe. The silver imme- diately fused and remained during that time in a molten state. When cold, the globule of metal was flattened into a plate, and having cut it into strips, and subjected it to a second heating, I succeeded in re- moving a considerable part of a per cent. of mercury from it. Wright’s researches on the gases of meteoric irons have shown a varying character in the oxygen and nitrogen lines when in the presence of hydrogen, and the near coincidence of two of them with prominent lines in the corona, with the possible coincidence of a third line, which appears to indicate that the characteristic lines in the coronal spectrum are due, not so much to the presence of otherwise unknown elements, as to hydrogen, and the atmospheric gases oxygen and nitrogen. The observations were made with a spectroscope of six prisms with a repeating prism, giving the dispersion of twelve in all. (Zo be continued in our next Number.) VI.—On THE OccuRRENCE oF Neocom1an SAnpDs witH PHOSPHATIC Nopuues at BrickutLL, BEDFORDSHIRE. By Water KEEPING, (Of the Woodwardian Museum), Christ’s College, Cambridge. N a traverse through part of Buckinghamshire and Bedfordshire | last vacation, with the object of tracing the extent of the Cam- bridge Greensand, I was informed of some recently opened Coprolite works at Brickhill, near Bletchley. On further inquiry, they proved to be the “red coprolites,” a term applied by the workmen to the phosphatic nodules of the Neocomian like those of Potton and Upware (the Cambridge Greensand and Gault nodules being known as the “black coprolites ”’). The workings are seen on a hill near Great Brickhill, which is about three miles from Bletchley Junction, and the section exposed is about thirty feet deep. The deposit is a rather coarse sand throughout, composed of grains of quartz, lydian stone, and comminuted shells, 1. Cailletet. Z’ Institut, Nouv. Sér. iii. 44. Walter Keeping—Neocomian Sands at Brickhill; Beds. Sv as) sometimes hardened by iron oxide or calcium carbonate; the former along lines of oblique lamination, the latter usually in irregular masses, which are rejected as useless. As I saw it, the lower ten feet was of a dull greenish or grey colour, passing in an irregular manner into the redder portions above; but there is no definite divisional line separating the two, the difference in colour being probably due to the oxidation of the iron in the more superficial part. As at Potton, these sands repose upon the Oxford-clay, the Gryphea dilatata being abundant in the clay beneath. Unlike any other coprolite working known to me, there is no ‘‘seam” here, but the phosphatic nodules are scattered through the entire thickness of the section,’ and they are separated by sifting the whole of the thirty feet of sands, except where they are too much hardened by cementing substances. Thus separated, the coprolites are washed in revolving perforated cylinders, and any pebbles of quartz, chert, lydian stone, etc., are picked out when the material is ready for grinding. The whole process is the sameas that carried on at Potton in Bedfordshire and Upware near Cambridge. From Paleontological evidence, we have long believed the Upware deposit (which has already been described in the pages of this Maca- ZINE?) to be the representative of, if not continuous with, the Farringdon Sponge-bed. Now Brickhill is nearly equally distant from Upware and Farringdon; here then is the spot to settle the question of their relation. The phosphatic nodules of Upware occur in the Neocomian Sands in three seams, which are irregular and sometimes run together,’ and in the Rushmoor Brickyard,* a few miles from Brickhill, the “ coprolites” may be seen similarly collected into a bed from four to seven feet thick, resting on the Oxford-clay. At Farringdon copro- lites are found scattered through the sands, especially towards the base. But few fossils are to be seen among the prepared coprolites, and these are mostly phosphatised casts in a much worn condition, so that a glance at the heap would lead one to observe with the Rev. P. B. Brodie,°> when speaking of the Potton bed, that ‘‘every organism in this phosphatic bed is evidently extraneous.” Ammonites biplex is always the conspicuous fossil in this condition, together with Cardium striatulum, Arca, and Myacites, all of which I found at Brickhill. But on breaking open the hard masses cemented by the carbonate of lime, and also in a small patch of the section where calcareous matter remained, the natives of the bed were themselves found, still with their shells well preserved. and in general appearance closely resembling those of Upware. The following is a list of them.® 1 Tn the lower part they are more numerous and blacker. 2 J. F. Walker, Grou. Mac, 1867, Vol. IV. p. 309. 3 Walker, op, cit. p. 310. 4 I was informed that about four years ago they bored for coal in this yard ! 5 Grou. Mac. 1866, Vol. III. p. 153. 6 Mr. J. F. Walker has kindly examined and confirmed my identifications of those species described by him in the Grou. Mac. Vol. IV. p. 454; Vol. V. p. 399. o7v4 Walter Rec Ne Sands at Brickhill, Beds. Those marked U, are known to occur at Upware, near Cambridge ; ¥, at Farringdon. Terebratula prelonga (Sow.), U, F. =f depressa (Liam.), U, F. a Moutoniana (dV Orb.), U, F, small and striated variety. an microtrema (Walker), U. Hi sella, var. Tornasensis (d’ Arch.), U, F. +3 extensa (Meyer), U. Seeleyi (Walker), U. Waldheimia Wanklyni (Walker), var. eldiptica, U. 5 pseudojurensis ' (Leym.), U, F. Terebratella oblonga (Sow.), F Terebratulina striata (Wahl.), var. elongata (Dav.).? Rhynchonella Cantabridgiensis (Dav.), U a Upwarensis (Day.), U Sj -antedichotoma Cel Wi, 18 hs depressa (Sow.), U latissima (Sow.), F Ostrea ‘macroptera (Sow, No Wy Lt Lima Farringdonensis (Sharpe), F, », Dupiniana (d’ Orb.), (?). Cidaris Farringdonensis (Wright), ? F. This list is extremely interesting, as being intermediate between the two remarkable and isolated faunas of Upware and Farringdon ;? for of the twenty species enumerated, no less than fourteen are common to Upware, twelve occur at Farringdon, and seven are found in all three localities. Terebratula microtrema, T. Seeleyi, Waldheimia Wanklyni, Rhynchonella Cuntabridgiensis, and R. Upwar ensis were hitherto unknown out of the Upware deposit. It may be found necessary to separate the specimens which I have named T. Jfoutoniana as a variety of that species, differing as it does from the type in being smaller and distinctly striated. We may call it Terebratula Moutoniana, var. Brickhillensis. It is conspicuous that the sponges so remarkably developed at Upware and Farringdon are absent from this list; this is, I think, accounted for by the want of calcium carbonate, such as might have been supplied by the Coral-rag of Farringdon and the Coral-reef of Upware. In the sands of both these localities fragments of the Coral Limestone are abundant; and I observed, when the fine series from Upware was being collected for the Woodwardian Museum, that nearly all the sponges were found close to the Coral-reef. Lately, since the workings have been removed only 200 or 300 yards further off, where the bed rests on the Kimmeridge-clay, sponges occur but rarely.° The coprolites at Brickhill are of the same type as those of 1 Mr. Walker informs me that this species has lately been also met with at Folkestone. 2 T am indebted to Mr. Davidson for this identification. Heinforms me that ‘ the same variety occurs in the Bargate stone (Upper Neocomian) of Guildford and Godalming im Sussex.” 3 I hope to be able to add to this list as the workings go on, the result of which may prove worthy of another communication to this Macazine. 4 Faint strie have been observed on some of the Upware specimens. See Mr. J. F. Walker’s article in Gzout. Mac. 1868, Vol. V. p. 403, Plates XVIII. and XIX. ne ° Hl father has since obtained for the Troadienitioan Museum a few sponges from rickhill, Reviews—Prof. Prestwich on the Past and Future. 378 Upware and Potton, viz. the light yellow varying to dark brown, almost to the black type, much worn before they reach the mill,’ and perforated by lithophagous mollusca and annelids. They contain (at Potton) about 48-51 per cent. of phosphate of lime.’ In conclusion, I may remark on the wide distribution of these Neocomian “coprolites.” They occur at Farringdon, Brickhill, Rushmoor, Potton, Upware, and I have lately found them in the Upper Neocomian Sands of Lincolnshire. In all these places they are of the same type, much worn and drilled, and abounding with Ammonites biplex and other Kimmeridge-clay forms. This fact of the Kimmeridge-clay origin of so many of these “coprolites” is of importance in considering the origin of the phosphatic matter ; for since we do not find the fossils in this phosphatised condition abundantly in the Kimmeridge-clay, while they are invariably so over a wide extent of country as derivative fossils in the Neocomian, we may infer that the phosphate was obtained in the latter period ; in other words, as suggested by Mr. Walker,’ that the coprolites are nodules derived from the Kimmeridge-clay, which have been ‘soaked ” with phosphates obtained by the decomposition of animal and vegetable matter in a shallow sea,* with, perhaps, some replace- ment of the phosphate of lime for carbonate of lime. I may observe also that at Potton fossils in this eroded condition occur of the Portland and Wealden ages—notably the Endogenites erosus of the Weald—indicating, as I believe, the former extension of these deposits near, if not quite up, to this locality.° Further north, at Upware, Endogenites erosa has not, to my knowledge, been found, and the Dinosaurian remains are much less frequent; so that the northern limit of the Wealden may reasonably be fixed at some place not far from Potton.® Ase ash WF Ih eH WAS Jo I.—Tue Past anp Future or Grotocy. An Inaugural Lecture given by JosspaH Prestwicu, M.A., F.R.S., F.G.S., etc., Professor of Geology in the University of Oxford, January 29, 1875. pp. 48, with four illustrations. (London: Macmillans.) R. PRESTWICH, after paying a just compliment to Oxford by noting how much the infancy of modern Geological Science was indebted to the labours and discoveries of Kidd and Buckland, 1 The eroded appearance of the Cambridge coprolites has frequently, and to a great extent incorrectly, been referred to the trituration produced by washing in the mills. * Vide analysis by. Dr. Voelcker, Grou. Mac. 1866, Vol. III. p. 154. 3 Ann. Nat. Hist. Nov. 1866. * This theory has no reference to the nodules of the Gault and Cambridge Green- sand, which are far too pure for such an origin. 5 Professor Morris has already (Grou. Mae. Vol. IV. p. 459) from similar evidence stated his conviction that the Wealden beds were present over the neighbourhood of Aylesbury. 6 M. J. Harris Hall, of St. John’s College, informs me that he found coprolites scattered over this hill at Brickhill about two years ago. The result of his inquiry into the Potton and Upware deposits (Sedgwick Prize Essay) will be published very soon. 376 Reviews—Prof. Prestwich on the Past and Future. enters on the consideration of the various cosmical hypotheses as to the origin of our earth, and probably of the other planets, in the condensation of nebular matter. In this he brings forward the yet unpublished and perhaps uncompleted views of Mr. Norman Lockyer, communicated by the latter to Mr. Prestwich, suggesting, from the analogy of the apparent solar constitution, that our globe in its nebular condition had its materials arranged in zones of different densities, the densest of course being innermost—a notion which Mr. Lockyer and Mr. Prestwich both think to be supported by the existing order of the materials constituting the earth, the metalloids forming the outer zones, succeeded by the denser substances, such as the metals, in the interior; granite and other acidic rocks being con- sidered the chief substance of the earliest outer crust, underlaid by the more basic rocks, basalts, magnesites and ferruginous rocks in the first instance, and further towards the centre by the metallic bases. This is a bold speculation, which we will not further remark upon, but leave it as a nut to be cracked by other cosmical geologists. Mr. Prestwich then proceeds from these highly speculative views to the more direct questions of geology proper, namely, Stratigraphy and Paleontology. He gives several ingenious diagram-illustrations of the proportionate occurrence of different species of organisms in the successive known strata. 'These must, however, be seen and carefully studied, as it would be impossible to explain them fully, unless we could introduce illustrations of them here. Mr. Prestwich then comes to what he calls the more especial ground of the geologist (p. 30), namely, ‘‘the various chemical and physical questions connected with inorganic matter,” in other words, “the great mechanical phenomena exhibited on the surface of the globe,’—the first question being whether these phenomena are most expressive of “energy” or of “ time;” in other words, the old dispute between the Cataclysmic and Uniformitarian theories. Upon this point Mr. Prestwich ranges himself rather with the former than the latter. Admitting the enormous and scarcely con- ceivable periods of time with which geology has to deal, Mr. Prestwich deduces from this not that the minor pkenomena which come within the range of our limited experience may, by their mul- tiplication in the course of these countless ages, be made to account for all the larger past changes of which we have evidence, but, on the contrary, that in the vast extent of previous time there is ample room for the possible occurrence of paroxysmal events infinitely exceeding in energy any with which our petty experience has made us acquainted ; and here he suggests the rather ingenious argument that, as the recognition of a glacial period has led to the admission of an early greater intensity of cold, so the evidence of a greater in- tensity of heat should by analogy be equally admissible (p. 36, note). From this Mr. Prestwich naturally proceeds to consider the hypo- thesis of central heat, and of the presumed contraction of the earth on cooling, “accompanied by a shrinking (? crumpling) of the crust, to which the trough of oceans, the elevation of continents, the pro- trusion of mountain chains, and the faulting of strata, are to be Reviews—Sharp's Rudiments of Geology. avd attributed.” He finds in these phenomena an argument for their explanation rather by sudden and excessively violent shocks at very distant intervals than by minor and more frequent oscillatory move- ments. We cannot in this brief notice enter on a criticism of this argument, or we might, we think, show that it contains a fallacy. We join, however, heartily in the concluding passage of this portion of the address : ‘“‘ Of these forces it is as difficult for us to realize the intensity as it is to fathom the immensity of space. These are among the questions of the future.” (p. 40.) Presuming, however, the earth to have arrived at present at a state of comparative “quiescence,” Mr. Prestwich suggests that the glacial period through which the earth has recently passed, owing to whatever cause, anticipated in some degree the ultimate refrigera- tion of the globe through the radiation of heat into space; and by retarding this process has tended to produce that “period of stable equilibrium ” which now obtains, and “which now renders it so fit and suitable for the habitation of civilized man;” and thus ‘impresses the author with the belief of great purpose and all-wise design.” (p. 48.) IJ.—Rvpiments or Grotocy. By Samurt Saarp, F.S.A., F.G.S. (Stanford, London, 1875.) HE object of this book is to give, in a condensed and useful form, an abstract of the most noticeable points in geological research. It is, in fact, rather a series of brief notes of lectures, than a treatise on Geology, and its very size, for it runs into little more than a hun- dred pages, precludes the possibility of the author’s doing more than indicating the salient facts and theories of the science. This has been satisfactorily attempted; and the arrangement is well adapted to the wants of students who seek for much information in a small space. The First Part deals essentially with Definitions, a separate para- graph being devoted to each; these are both word-derivations, and, in many instances, explanatory notes of the matter in hand; and are of considerable value. For example, paragraph 15, which relates to “ the processes by which sedimentary strata have been formed at the bottom of rivers, lakes, estuaries, and seas,” does not confine itself to a brief statement that Denudation (marine, sub-aerial, or glacial) was the chief cause, but proceeds to describe the process, and to give numerous examples of the action of these several agents. There is, however, a tendency in some instances to popularize in- formation and simplify terms in a hasty and inaccurate manner. This may often lead to false impressions. Thus granite is spoken of as ‘‘ the original foundation and source of all rocks,” which is certainly open to question. Again, some of the derivations of tech- nical wordsare careless ; for stratum is not a “covering” body, onta are not necessarily “ existing” beings, meta is not ‘“‘ change,” and, if the 378 Reviews—Sharp’s Rudiments of Geology. Alpine streams carry down an ‘‘incalculable” quantity of material, geologists may as well give up the attempt to be exact in their calcu- lations. The same want of care is evidenced in other pages; thus we may remark, in the enumeration of the characteristic fossils of the Stonesfield Slate, Mr. Sharp notices the occurrence of “ the wing-cases of Beetles, a beautiful wing of a Butterfly, and many insects,” which sentence requires the addition of “other” before the final noun to be correct. So also at page 48, “ Mollusca are less plentiful than Cephal- opoda”! Still these slight inaccuracies are of little importance, and do not greatly militate against the undoubted value of the work. Part II., which deals with the Stratigraphical and Paleontological data, is prefaced by a well-arranged table, giving, in addition to the customary list of formations, the maximum thickness of each set of beds. Then follows an account of the various divisions and sub- divisions of these formations, useful references being made in each case to the lithological and paleontological characteristics of each, sufficient to give a good general idea of the nature of the groups of strata; and, though space admits neither of illustration nor details, the brief account of the most remarkable fossils is clear, though the natural-history knowledge exhibited is by no means perfect. The more important groups of the animal and vegetable life of the several epochs are alone referred to; and the most important litho- logical features and fossils, which would lead to the general identifi- cation of the groups, are enumerated and defined, so as to admit of ready appreciation by an inexperienced student. Great care is shown in the description of the Oolites, and, brief as it necessarily is, it is full of value; the range, for instance, of the more or less marine beds of the ‘“ Stonesfield Slate” through North- amptonshire and Lincolnshire, possibly to Scarborough, where it “is probably ultimately represented by the Upper Plant Shale,” being clearly explained by the successive alterations in the Paleontological peculiarities of the series of beds. In fact, the author seems to be essentially an Oolitic Geologist, treating the older beds, from the Lias downwards, and the upper beds from the Purbeck upwards, chiefly in the light of Lyell’s “‘ Student’s Manual ” and other elemen- tary works and compilations. The book closes with a short description of the first-known appearance of Man upon the earth; flint implements being found as- sociated with bones of the Elephant, Cave-Bear, etc., but not with human bones; and the history of this most interesting branch of modern geological research is shortly told. Mr. Sharp’s “ Rudiments of Geology” will be a useful book for geological students of all classes. To the more advanced reader it furnishes a handy précis of the chief points in the branch of science he pursues ; for the beginner it provides the scaffolding wherewith he may arrange his future studies and build up his knowledge. C. Coorer Kina. Reviews—Geology and Races of India. 319 TII.—“«Tur Grotogy anp Races or Inpra.” (EpinpurcH Review, April 1875.) N article in the April number of “The Edinburgh” treats at some length of the Geology of India, and its connexion with the races of that country. With the latter part of the subject it is not necessary to deal here, though the affinity between Race and Geology may be thought somewhat loosely and discursively treated as an attribute of scenic and agrarian influences; the reader being referred to Buckle’s “‘ History of Civilization” for the laws which regulate the influence of soil and climate upon the creation of wealth, civilization and luxury: while it is difficult to gather from the article itself the slender links between intellectual development of national character and the “stupendous convulsion of the Himalaya,” the derivation of Régur, the existence of concealed coalbeds, or the presence of “great trappean effusions.” The writer’s descriptions of the Geology of India are however too startling to pass altogether unnoticed when advanced in the pages of such a journal as the Edinburgh Review; nor would it be fair to authors upon Indian geology to allow him to claim for strangely mingled misrepresentations that they are given ‘“‘as detailed by skilful observers.” These descriptions being taken professedly from “ amateur authors ”—but largely, one might imagine, from Dr. Carter’s Sum- mary and Mr. H. Blanford’s recently published excellent little work on the Physical Geography of India—it is to be regretted that the writer of the article seems to have assumed the equally ‘‘admirable accuracy ” of all, and, relying upon this, to have failed in discrimina- tion, while committing himself to statements at variance with facts, familiar to those whose acquaintance with the subject is not altogether circumscribed, or whose desire to increase this knowledge might be stimulated by a paper in an ably-conducted journal. It is also matter for much regret that, without wading through the whole of the amateur literature of the subject noticed by the writer, besides all the Government publications, no means exist whereby a more ample knowledge of the general features of Indian Geology can be acquired than may be gathered from the chapters by Mr. Henry Blanford—once an officer of the Indian Survey, and now Chief of the Indian Meteorological Department. It has been suggested that the Indian Geological Survey has now sufficiently progressed to enable it to furnish some approximately accurate map and sum- mary of the geology of the whole country. Nothing comprehensive in this form has appeared as yet, but it is evident from the article in question that such a publication is needed; and this could hardly be more competently edited than by the veteran Chief of the Survey, with his long experience, if leisure could be found among his other pressing labours. As it is, the science itself is progressive, and ample time has passed since some of the amateur papers were written to have placed them behind the age. This however will not excuse the writer of the article referred to for want of acquaintance with some of his own sources of infor- 380 Reviews— Geology and Races of India. mation, when we find it asserted that the oldest rocks of the Hima- layas are not of greater antiquity than the Hocene period (p. 382), though this is directly contradicted in a quotation at p. 334, and the late Dr. Stoliczka, Major Godwin-Austen, etc., have recorded their discoveries of Silurian, Carboniferous, Triassic, and other fossils in the Himalayan ranges. Again, he speaks freely of the Paleozoic rocks of Central India, large tracts of which contain no known fossils older than a presumably Jurassic or Cretaceous period, while other enormous spaces are occupied either by crystalline rocks or by layers of bedded trap forming whole ranges of mountains or plateaux like the Deccan, containing, but rarely, in intercalated strata, fossils of Tertiary age (!). Nor is he altogether happy in his conception of a skeleton series of Palzozoic ranges filled in between by deposits of various following ages, resuléiny from enormous volcanic action (!); the upheaval, contortion, and twisting of the plutonic rocks being attributed to “eruptive powers”—while the Cambrian and Silurian series of Central India (!) are mentioned, but we are not told where they may be found, or on what evidence their assumed age is based. After this an imaginary and imposing volcanic upheaval of the Deccan is spoken of as pre-Miocene, while above certain coarse marine formations of that age there is a newer great Trappean “effusion ” referred 10, the real existence of which would be even more difficult to prove than the production therefrom (p. 833) of recent Régur and Kunkur or Travertine, or the eruption of felspathic traps of Oolitic age through the Régur of the Carnatic (!) (p. 336). However far a careless writer might be excused for conveying rather mixed ideas of a subject he was unacquainted with, derived from many sources of differing degrees of accuracy, or perhaps in some cases of inaccuracy, there can be no apology for the inconsecu- tive and contrary assertions,—in one place that the rocks of the pen- insula are intensely disturbed, and in another that the beds south of the Ganges Valley are not in any way contorted or crushed (!). It will be new to any one slightly acquainted with Indian geology to learn “that the geology of the Punjab is wholly Tertiary and Alluvial,” and that ‘all indications of Primary or Paleozoic rocks are entirely absent ”—it having been recorded long ago in the publications of the Geological Society of London (not to mention Indian authorities) that the great Salt Range of that district contains highly fossiliferous Carboniferous limestones and other pre-Tertiary formations. The old error of the province of Kutch being “remarkable for its craters and other evidences of recent volcanic action,” is repeated, and a partial upheaval from the sea is stated for the “ Runn,” although tolerably recent information upon these points is available in a published form. The economic subjects of Indian coal and iron are noticed, the first in some detail; but nothing is said of the great salt deposits of the north. Discrepancies as gross as these throughout the geological portion of the article leave the impression that the writer was either feebly acquainted with geological subjects, or has most imperfectly collected the materials of which his paper is made up, Geological Society of London. 381 and we would recommend a reader interested in the matter to turn instead for information to Mr. H. Blanford’s little book and to the geological chapters published, or in course of publication, in the Government of India’s Gazetteers for each of the Presidencies, wherein condensed accounts of the local geological features will be found. REPORTS AND PROCHEHEDINGS. ————_— Groroercan Society or Lonpoy.—May 26th, 1875.—John Evans, Hsq., V.P.R.S., President, in the Chair.—The following communi- cations were read :— 1. “On some Peculiarities in the Microscopic Structure of Fel- spars.” By Frank Rutley, Esq., F.G.S. The observations recorded in this paper related mainly to some exceptional features in the striation of felspars from various localities, involving a consideration of the extent to which dependence may be placed on the discrimination of monoclinic and triclinic felspars by the methods usually recognized in ordinary microscopic research. Some other peculiar structural features were likewise noticed, and the effects which might’ be produced on polarized light by the over- lap of twin lamelle in thin sections of felspars, when cut obliquely to the planes of twinning, were also considered, The paper terminated with a list of conclusions deduced from the observations recorded. These conclusions mostly related to matters of detail; but the general inference drawn by the author was that the present method of discriminating between monoclinic and tri- clinic felspars by ordinary microscopic examination answers sufficiently well for general purposes, although it is often inadequate for the determination of doubtful examples, and that such examples are of more frequent occurrence than one would at first be led to suspect. 2. “On the Lias about Radstock.” By Ralph Tate, Esq., A.L.S., In this paper the author described several sections in the Lias of the neighbourhood of Radstock in Somersetshire, with special reference to their paleontological contents, and to the question of the division of the Lias into zones in accordance with the species of Ammonites occurring in different parts of the series. He maintained that although the Lower Lias in this district only attains a thickness of 24 feet, this is due to poverty of sediment; and that whilst by this means the zones are compressed, and the species of Am- monites brought almost into juxtaposition, the succession of Am- monite-life is as regular in the Radstock Lias as in the most typical districts. Much of the opposition to the doctrine of zoological zones he ascribed to erroneous discrimination of species. The paper included tables of sections and lists of fossils, with the arguments founded upon them, in support of the above opinion. A few new species were described under the names of Trochus solitarius, Cryptena afinis, Cardita consimilis, and Cardinia rugulosa. 382 Obituary—Sir William Edmond Logan. 3. “On the Axis of a Dinosaur from the Wealden of Brook, in the Isle of Wight; probably referable to Jguanodon.” By Prof. H. G. Seeley, F.L.S., F.G.S. This perfect specimen, preserved in the Woodwardian Museum of the University of Cambridge, is 384 inches long and 31 inches high. The odontoid process is anchylosed to the axis, and projects forward as in the axis of birds, so as to articulate with the occipital condyle of the skull. The pre- and postzygapophyses are situated much as in birds; as are the two ovate pedicles, on the anterior part of the side of the vertebra to which the cervical rib was articulated. But. posteriorly the articular surface for the third cervical -vertebra is transversely ovate and slightly concave. The neural spine is com- pressed from side to side, more so in front than behind. Among mammals, the nearest resemblance to this kind of axis is seen simi- larly in the whale; and among reptiles the crocodile has a two- headed rib; but the other characters are more like those of Hatéeria, which the author regarded as a near ally of the Crocodilia and Chelonia, and as wrongly united with the Lacertilia. 4, “On an Ornithosaurian from the Purbeck Limestone of Lang- ton, near Swanage (Doratorhynchus validus).” By Prof. H. G. Seeley, E.L.S., F.G.S. The author obtained these specimens (a lower jaw and a vertebra) in 1868, and described them in the “ Index to the Secondary Rep- tilia, etc. in the Woodwardian Museum,” in 1869, as Pterodactylus macrurus. He now believed that the Ornithosaurian vertebre from the Cambridge Greensand, which have been regarded as eaudal, are really cervical, and therefore that the analogy on which this vertebra was determined to be caudal cannot be sustained; he proposed to adopt for his species Prof. Owen’s specific name validus, given in 1870 to a phalange of the wing finger from the same deposit. The vertebra is 5 inches long, relatively less expanded at the ends than similar vertebree from the Cambridge Greensand, has strong zygapophysial processes, and a minute pneumatic foramen. The lower jaw, as preserved, is 124 inches long. The symphysis extends for 5 inches, and is about 4 of an inch deep, and divided into two parts by a deep median groove. The teeth extended for 8 inches along the jaw, and about 7 or 8 occurred in the space of an inch. They were directed outward in front, and became vertical behind. Where the rami are fractured behind, they measure 24 inches from side to side. (OS EAL OP/AASINS— SIR WILLIAM EDMOND LOGAN. LL.D., F.R.S., F.GS., V.P. Nat. Hist. Soc. Montreal. Yet another leading man has passed away—one whose name has become familiar to geologists during fifty years of the most vigorous growth of our science, and one whose labours and researches have . contributed in no small degree towards that development and progress of ideas by which geology at the present day is characterized. Obituary—Sir William Edmond Logan. 383 William Edmond Logan (who was of Scottish parentage) was born in Montreal in 1798. His education, commenced in Canada, was con- tinued at the High School and in the University of Edinburgh. He soon displayed a love for geological pursuits, and commenced in South Wales carefully to study the structure of the Coal-field of that region, and to map the outcrop of its numerous Coal-seams, depicting their faults and most minute details on the One-inch Sheet of the Ordnance Survey. This admirable work he generously handed over to Sir Henry de la Beche when he began the Survey of that district, and on the early Sheets of the Government Geological Maps for South Wales the name of W. E. Logan appears with those of De la Beche, Ramsay, Phillips, and Aveline. During this time Logan worked on the staff of the Survey as a volunteer, and among other valuable services rendered he introduced the practice of drawing horizontal sections on a true scale of six inches to a mile, which afterwards served as models for the large sections of the Survey. At this early part of his career Logan made a most important obser- vation on the origin of coal, then but little understood. He pointed out that each coal-seam rests on an “ underclay” or “ fireclay,” which rootlets of Stigmaria branch freely in all directions. This association of coal and Stigmaria-clay he found to be so constant that he was led to the conclusion that the clay represented the ancient soil or mud in which the St:gmaria grew, and that the coal was the result of the accumulated growth and decay of the matted vegetation which had once lived upon that soil. Looking back, after a lapse of forty years, we are astonished at the brilliance of Logan’s early deduction, which served to throw so clear a light upon the nature and origin of coal, and entitles its author to our highest esteem as a most careful and accurate observer. In 1841 Mr. Logan went to America, and examined the coal-fields of Pennsylvania and Nova-Scotia, where he also made some original observations. In the winter of 1841-42 he devoted himself to watching the behaviour of ice as a geological agent on the great Canadian rivers. The result of his studies was communicated by Logan in person to the Geological Society of London in the spring of 1842. About this time (1842) there arose in Canada a strong desire to know something more about the mineral resources of the Colony, and the Legislature having voted £1,500 for a Geological Survey, the Canadian Government consulted the Home Office as to a suitable person to under- take the task, mentioning the name of Mr. Logan, and inquiring in what estimation he was held in England by scientific men. Murchison was at that time President of the Geological Society, and, being appealed to, he warmly recommended Logan, as did also his old friend De la Beche. From his appointment in 1848 Logan’s whole energies were given to the task assigned to him, and to his devotion and untiring energy must be attributed the fact that he never allowed the difficulties of his task to overpower him, although beset on all sides with obstacles sufficient to have disheartened men of less determination and ability. The country over which his Survey extended was frequently obscured by dense vegetation. There was no Ordnance Map to use. ‘The 384 Obituary—Sir William Edmond Logan. Government, moreover, only acted on impulse, and soon were ready to abandon a Survey which had only been sanctioned by them in a fit of patriotic fervour. Through all these obstacles Logan’s tact and per- severance enabled him to steer his bark, and finally to gain the haven of popularity, while success crowned his efforts in the field. Year by year his annual reports were presented to the Canadian Parliament, accompanied by admirable Geological Maps, and it is in these official reports that the chief work of his life is embodied. He was fortunate in securing excellent assistants in his field work ; men whose names are well known to geologists: Alexander Murray (now Director of the Survey of Newfoundland), James Richardson, and in later years Robert Bell, and others. For mineralogical and chemical examination of rocks he secured.the services of Dr. T. Sterry Hunt ; while for the paleontological determination of the fossils he obtained the aid of Mr. E. Billings. Perhaps the best proof of the benefits con- ferred by the Survey upon Canada is furnished by the firm footing and liberal support which it now obtains from the Provincial Legislature. The Survey has its Museum and a Laboratory, where the minerals, rocks and fossils of the country are examined and illustrated with especial reference to the industrial resources of the country. By such methods alone can scientific men hope to succeed in securing the hearty co- operation of Colonial Governments. All young States require to be shown some commercial advantage to be derived from geological and other investigations; and in proportion to the success with which this aspect of the subject is put before them, so will be the support given to such scientific undertakings. After the Paris Exhibition of 1855, at which the mineral productions of Canada had been so successfully exhibited by him, the honour of knighthood was conferred upon Sir William Logan in recognition of his long and unwearied exertions in carrying out this important task. He devoted himself with equal energy to the interests of the Colony at the International Exhibition of 1862. The generalized sum- mary of the labours of the Survey of Canada, during the first twenty years of its existence, published in 1863, contains the gist of his work as well as a luminous account of all that was then known of the geology and mineral wealth of the Province. Finding his duties too heavy for his advancing years and failing health, Sir William resigned his appointment in 1869, and was suc- ceeded by Mr, A. R. C. Selwyn, formerly of the Geological Survey of Great Britain, and afterwards Director of the Survey of Victoria. Sir William Logan gave 20,000 dollars towards the endowment of a Chair of Geology in M’Gill’s College, Montreal, and up to the last his interest in his favourite science was unabated. Well has Prof. Geikie observed: ‘‘ He has done a great work in his time, and has left a name and an example to be cherished among the honoured possessions of Geology.”’ ! 1 Nature, July 1st, 1875, to which we are indebted for the main facts and most of the statements contained in this notice. THE GEOLOGICAL MAGAZINE. NEW= SERIES“ DEGADE hl VOL? Al. No. IX.—SEPTEMBER, 1875. Oe Gab AN Asry /2Asey res: Galea s ——>—— I.—Snort SKetTou oF THE GEOLOGY or THE NortH or Norway. By Karu PErrerseEn. EOPOLD VON BUCH, who in the beginning of this century travelled through Norway as far as the North Cape, was the first who wrote about the geology of the northern part of the country (Reise durch Norwegen und Lapland, Berlin, 1810). Some years later the natural conditions of the country were examined by Vargas Bedemar. On this voyage he went as far as Varanger, and has recorded the result of his inquiries in his work “Reise nach dem hohen Norden, Frankfurth-a.-Main, 1819.” Furthermore R. Everest, who travelled through Norway to the North Cape in the years between 1825 and 1830, has collected various notices on the moun- tain structure of the countries in his work entitled “Journey through Norway.” If we consider the vast tract which these men of science had to go over, and the short time they had at their disposal for this pur- pose, it will be evident that we cannot expect to find in their works complete surveys, but only more or less scattered remarks on the geological structure of the country. In the years 1827 and 1828 Keilhau had occasion to make more comprehensive investigations in the northern parts of the country, and he succeeded also in giving the first hints for a separation of the principal groups which form the mountainous ground of these regions. - Of course Keilhau never intended to give anything more than preliminary hints. If one takes into consideration that the area of Finmark is fee geographical square miles= 43,480 square kilom. en Tromsé “‘Amt” 412 55 3 = 22,710 3 5 Nordlands “‘ Amt” 687 9 5 = 37,820 Fe together 1889 = » = 104,010 e it will be clear that a man, in the course of the summer months of a couple of years, will only be able to go over so vast an extent of country superficially. Moreover, the land is thinly populated; the actual inland area is for the greater part barren; and the “ Amts” of Tromsoé and Nordland especially form an extremely wild mountain land, frequently intersected by deep fjords, valleys and gorges. Scientific journeys are therefore in these parts always connected with great difficulties. —- - DECADE II.—VOL. II.—NO. IX. 25 386 Kari Pettersen—Geology of N. Norway. Keilhau has given the result of his inquiries in his well-known work : “ Goea norvegica, 2 volumes, Christiania, 1844.” More connected geological examinations of these countries were commenced in 1865, and have been continued, but are still far from being concluded. During this time Mr. Tellef Dahll has gone over Hast Finmark and the inland of West Finmark, and the author of these pages over the coast-land of West Finmark, the whole of Tromso Amt, and the greater part of Lofoten and Vesteraalen in Nordlands Amt. A more detailed description of the course and results of the investigations will be found in the following treatises: Tellef Dahli. On the Geology of Finmarken. Christiania Scientific Society, 1867, pp. 213—222. Kari Pettersen. Geological Profile from the Boundary of the State over Lyngen to Kvalo. Chr. 8. 8. 1867, pp. 155—158. 5 Profile through the Bed of the Reisen-ely over Ul6 and Kaagen. Chr. 8. 8. 1868, pp. 316—321. 0 Geological Investigations in the Tromsé District. The Royal Norwegian Scientific Society’s Writings, vol. v. pp. 118—240. Trondhjem, 1868. %0 Geological Investigations in Tromso Amt IJ. R. N.S. S.’s Writings, vol. vi. pp. 41—165. Trondhjem, 1870. On the Elevation of Tromsé Amt over the Level of the Sea in the Glacial and Postglacial Age. R. N.S. 8.’s Writings, vol. vi. pp. 166—189. Trondhjem, 1870. Geological Investigations in Tromsé Amt III. On the Formations of Quaternary Age. R. N. 8. 8.’s Writings, vol. vil. pp. 103—176. Trondhjem, 1872. » Tromsé6 Amts Orology. R. N. 8. 8.’s Writings, vol. vil. pp. 181—240. Trondhjem, 1872. 0 Geological Investigations in Tromsé Amt IV. R. N. S. S8.’s Writings, vol. vil. pp. 260—444. Trondhjem, 1874. ss On the Kind of Rock to be found within the Amts of Tromsé and Finmarken. The Geological Society's Discussions in Stockholm, 1874, vol. i. pp. 274—281. 3 Anorthite-Gabbro in Seiland, West Finmarken. G. 8S. D. in Stock- holm, vol. i. no. 4. 1874. ‘3 Arctis—a Contribution to throw Light on the Distribution of Sea Land and in the European Glacial Age. G. 8. D. in Stockholm, vol. il. no. 5, pp. 2—16. 1874. a On the Occurrence of Eleolite in West Finmarken. G. 8. D. in Stockholm, 1874, vol. ii. pp. 220—222. 5 Natural Formations of Tunnels and Caves in the Coast-line of West Finmarken. G. 8. D. in Stockholm, 1875, vol. ii. 36 The Gneissoid Granite Formations along the Coast-line of the North of Norway. G. 8. D. in Stockholm, 1875, vol. ii. no. 11, pp. 450-468. Tn the following pages we shall try to give a concise view of the re- sults gained through the researches instituted up to the present time. In the districts (Amts) of Finmark and Tromso, and in the shrieval districts (Fogderier) of Lofoten and Vesteraalen in the district (Amt) of Nordland, there occur from below upward the following stratified groups: I. The primitive rock.—This appears as narrow or wider stripes in the coast-tract Island-group from Mageré towards the north, to the termination of Lofoten in the south. It forms moreover the northern part of the peninsula which projects between Alten and Karl Pettersen— Geology of N. Norway. 387 Porsanger and the greater part of the high and wild peninsula which extends from Langfjord and Alteidet westward in the direction of Loppen. In the inland area of the district (Amt) of Tromso the primitive rock appears in several places, but always in narrower stripes. The masses of the strata are formed of grey and red gneiss, horn- blende gneiss and hornblende slate, hard micaceous schist, mild shining mica-slate and quartzitic slate. Also layers of chloritic slate may be found alternating with the same. The strike goes usually in the direction of north and south, with deviations sometimes on the one side and sometimes on the other. The dip is often con- siderable, sometimes even vertical, but in other places it is more nearly horizontal. The dip is to the east or to. the west, or sinuous. In some places where the dip is great, such strong sinuosities may repeatedly occur in a longitudinal extent of some few hundred métres. From the regular north and. south direction of the strike there may occur in some places strong local deviations, even. changing to an east and westerly direction, in large connected tracts. With this widely extended gneiss section there are connected large masses of granite, gneissoid granite and granitoid gneiss _ forming the chief part of the great Island-group of the coast-tract. The connexion between the purer gneiss and the granitic rock is such that, in spite of the strong petrographic divergence between the extreme links, there appears to be every probability that gneiss and granite with reference to their- common origin and age belong to one and the same main group. Gneiss is on the whole poor in accessory minerals; but in micaceous gneiss, red garnets are often found in great abundance. Also blue disthene is found in one place in the gneiss. Graphite often appears in it in the shape of leaves or lumps. In the grey gneiss we find Fahibands with a sprinkling of. Pyrites. For a more particular estimate of the thickness of the primitive rock occurring here, the necessary data are wanting. That the thickness is however considerable, appears from what may be ob- served in the occurrence of this rock in the region of Ribbeneso in the parish of Karls6. The so-called primitive rock here treated of is probably that which may be most likened to the Laurentian formation observed in Canada. This formation is here supposed to be divisible into an older and a younger section. IJ.—-The Tromso mica-slate group occurs in the coast-tract Island- group in several places over a greater or less area. For instance, in Sdrdé, Loppen, Vanna, Rinevatsd, Kvalé, Senjend, Hindo, while in the islands of Lofoten and Vesteraalen it is almost entirely sup- pressed. But it forms especially a very prominent link of structure in the mainland tract proper of the Tromsé Amt. The mica-slate group is formed of mica-slate, quartzitic slate, and sometimes also hornblende-slate; but the strata of greyish-white coarse granular limestone are most frequently occurring and charac- teristic of the group. 388 Karl Pettersen— Geology of N. Norway. Intercalated beds of a greenish actinolite slate are observed in various places. In Tromso there are layers of an eclogitic rock alter- nating with the mica-slate; and along the Gullesfjord at Hindo of garnet rock alternating with coarse granular limestone. Alum- slate is frequently found in the mica-slate section. The direction of the strike in this section agrees approximately with that observed in the gneiss section. The dip may be partly east and partly west. Through a profile line in an easterly direction from the coast to the boundary of the realm, there occur as many as four deviations in the direction of the dip. As accessory elements there may be remarked : 1) In the proper mica-slate:—red garnets, with which the rock is often abun- dantly sprinkled; blue disthene, staurolite, pistazite, titanite and magnetite, which last mineral may in some places appear in the slate in such abundance as to form an esential element in place of the mica. 2) In the coarse granular limestone:—mica, quartz, pyrites, graphite, the last mineral often abundantly mixed with the stone in small leaves and stripes; also tremolite, often in fine broad bar-like aggregations ; felspar and scapolite. 8) In the green amphibolitic actinolite slate :—yellow epidote. 4) Inthe amphibolitic partly eclogitic rock :—black hornblende, inlaid like por- phyry, magnetite, quartz, titanite, tourmaline, pistazite, garnet, calcareous spar, scapolite, apatite and oligoclase (with twin striation). In a quartz vein which traverses the mica-slate there has been found reddish fluor-spar. ayers of the Fahlband character are found in some places sprinkled with copper pyrites. The thickness of the group reaches up to 1900 metres. Petrifactions have not hitherto been observed. The age is consequently undecided. Probably it is old Cambrian (perhaps analogous to the Huronian formation). TIJ.—The slate-field of Balsfjord occurs in large connected tracts in the interior of the Amt of Tromso, and further in some of the islands of the coast tract, viz. Ringvatso and Hindo. The group is formed of a series of layers of argillaceous slate, argillaceous mica- slate, shining slate, and hard slate. Among these there are found thick inlayings of a limestone, which is partly coarse-grained and greyish, partly bluish-black and carboniferous, and often rather fine grained. Alum-slate also occurs frequently between the layers of the slate group. The limestone often contains much magnesia (magnesian lime- ‘stone). The latter often contains magnetic iron, which also appears in more connected vein-like masses. In the quartz-layers connected with the group there are found in some places, in drusy cavities, very beautiful rock crystals. Argentiferous galena occurring in lumps in layers of quartz and limestone is found in one place, namely, the mountain district of Rubben at Bardo. With the Group II., as also with the Group III., there are con- nected frequent layers of soap-stone, in which may be found both Bitterspar and pyrites. The direction of the strike in this group is predominantly 60° to 70°, the dip northerly, usually slight and seldom over 30°. Petri- factions have not been observed in this group. The age is, conse- quently, undecided—probably younger Cambrian (may possibly be Karl Pettersen—Geology of N. Norway. 389 designated as Taconic). The thickness of the group is considerable, but cannot at present be ascertained. TV.—The Alten and Kvcenangen group (the Raipas system, Tellef Dahll) appears most developed at the bottom of the Altenfjord in > West Finmark, always in wider and narrower stripes towards the bottoms of several of the fjords of Hast Finmark. In the Amt of Tromsé it appears along the interior of Kvcenangen well developed, on the island Vanna, in the parish of Karlsé, and again in several places on the mainland; but here it is generally quite subordinate. The series of strata of the group is formed of black, green, red, and violet argillaceous slate, quartzite and reddish sandstone. ‘The most significant link is, however, a yellowish-white magnesian lime- stone (Dolomite), which occurs in layers, and in some places may attain a thickness of up to 30 métres. The slate tracts of the group are often traversed by veins of red hematite (Iron mica). There is, moreover, a deposit of copper ore (copper pyrites and variegated copper ore, erubescite) connected with this group, but specially only in the characteristic greenstone formations, which frequently traverse the strata. The mining fields of Kaafjord and Kvcenangen are thus traversed by veins of quartz and lime traversing the greenstone. The position of the layers in the group is most frequently charac- terized by strong sinuosities and contortions. The thickness of the series of layers cannot therefore be determined with any great degree of accuracy. Neither have any petrifactions been found in this group. The age is probably Silurian (or Devonian). V.—The Golda group (the Gaisa system, Tellef Dahll) appears as the final link completing the rock foundation in large connected tracts in East and West Finmark, and can moreover be traced down through the interior of the “Amt” of Tromsé, along the frontier of the realm towards the south to Ovre Rostavand. The series of strata is formed of clay and argillaceous mica-slate, mica-slate, quartz-slate, and sandstone quartzite, and moreover of yellow and red sandstone, which completes the series. Inlayings of limestone are, so far as has hitherto been ascertained, entirely wanting. The mica-slate may in some places be richly sprinkled with small red garnets. No other accessory component parts have been observed. At Bescades —a mountain tract along the Alten river—there appear afew thick layers of tolerably pure graphite (Tellef Dahll). On account of the absence of petrifactions, the age of the group cannot at present be accurately determined. It is perhaps Devonian. The groups of the Secondary period are here quite unrepre- sented,—a locally occurring section of the Jura formation at Ando in Vesteraalen only excepted. Neither is there here any represen- tative of the Tertiary formation. On the other hand, there are in several places formations from the Quaternary period along the beds of rivers and channels, consisting of layers of clay and sand, which contain numerous remains of the shells of species of Molluscs which are all now living on our coasts and in our fjords. These formations are observed up to an elevation of about 60 métres above the present level of the sea. The formations of the Quaternary period are com- 390 Karl Pettersen—Geology of N. Norway. pleted by the banks of shells, that is, by a layer of about two métres thick entirely composed of remains ‘of shells of species of Molluscs now living. These banks of shells, of which the formation is still progressing, are observed up to an elevation of about 10 to 12 metres above the present sea-level. Moreover, it may be remarked in this respect that on many points along the coast there is found pumice- stone washed up—in some places even in great quantities ; which is still at this day continually washed up by the sea-currents, to an elevation of about 26 métres above the present sea-level. Throughout the Quaternary period the land has been subjected to an upheaving of about 120 métres, and this elevation has been con- tinued down to the historic time. As to whether the land is still rising there is no positive evidence existing. ‘In any case, it is cer- tain that the elevation during the last 1000 years has been quite insignificant. When it is stated in so many quarters as a geological fact, that the northern part of Norway rises about one-third of a metre in a century, this rate is evidently much too great. With respect to the question whether the elevation noticed during the Quaternary period has taken place by sudden impulses, or evenly and slowly, it is in any case certain that the land as regards the last ten métres has risen slowly and regularly. The unstratified rocks which break forth through the tracts of country here noticed are— 1. The gneissoid granite of the coast-tract, which forms rela- tively the greatest part of the groups of islands of the coast-tract. It appears, sometimes, as a striped granite; sometimes as a granite gneiss and as gneiss granite ; but often also as pure granite, through all possible transitional forms from gneiss to pure granite. The felspar is usually formed of reddish orthoclase, but oligoclase occurs also. The mica is most frequently brown magnesian mica. In some places hornblende takes the place of the mica; and the rock then goes over to hornblende-granite. Red garnets are found in some places in the gneissoid-granite. Magnetite and pyrites are frequent accessory minerals. The gneissoid granite is often traversed by layers of quartz, which are sometimes thick. In one place the granite is found traversed by veins of carbonate of lime. ‘The gneissoid granite forms most fre- quently wild mountain tracts, whence there shoot up series of peaks and pinnacles, the shapes of which are often very wonderful. Some of these may reach to a height of about 1300 métres. Open ways or tunnels traverse many of the mountains that are formed of gneissoid granite. Some of these tunnels are situated at an elevation of about 500 métres above the sea-level. 2. Inland Granite—Various larger and smaller granitic masses crop up in the interior as well in the Amt of Finmark, as in that of Tromsé. The Inland granite in the Amt of Tromso may often be regarded as an oligoclase granite; oligoclase being here often found tolerably predominant by the side of orthoclase. 3. Gabbro or Hypersthenite crops out in thick masses in the northern part of the Amt of Troms, as also in West Finmark. The Karl Pettersen—Geology of N. Norway. 391 thickest of these masses forms the Gabbro field of Lyngen, extending from the bottom of Balsfjord in a south and north direction, between Ulfsfjord and Lyngenfjord, to a length of about nine geographical miles, and with an average breadth of about one mile. The islands of Kaagen, Arné, Seiland, and Sdré are likewise traversed by con- siderable courses of Gabbro. Moreover, Gabbro-like masses of a more subordinate character break forth in the gneissoid granite of the coast-tract. The land tracts formed of Gabbro are in the highest degree wild and rugged. In this respect the Gabbro course of Lyngen is par- ticularly remarkable, shooting up in an infinity of peaks and inac- cessible pinnacles, of which some attain a height of about 2000 metres. The Felspar of the Gabbro is formed of plagioclase (Labradorite and anorthite)—a form which G. Rose termed eucritic—some- times of Saussurite (Saussurite Gabbro). The augitic element is partly diallage, partly also hypersthene. Sometimes the rock may also go over to a hornblende-gabbro. Olivine is a tolerably frequent mixture. Magnetite, Titanic iron, and Pyrites are frequently found in the rock; sometimes also copper pyrites and apatite. A smaller mass of Gabbro breaking forth in the west side of the great Senjen island is traversed by a thick vein of magnetic pyrites mixed with copper pyrites. The magnetic pyrites contains here 2 to 3 per cent. of nickel. The important nickel works of Berg are situated on this lode. Masses and courses of serpentine are often connected with the Gabbro. The serpentine is here probably only a transformation product of the Gabbro. 4. Greenstone—sometimes more coarse-grained, sometimes fine- grained—is frequently found connected with the Raipas group in Alten and Kvycenangen, and on the island of Vanna, in the parish of Karlsdé. The chief elements of the rock are hornblende and plagioclase. The stone is often traversed by stripes of yellow epidote, sometimes associated with calc-spar and scapolite. Mica, apatite, magnetic iron, pyrites and copper pyrites are not seldom found as accessory minerals. The greenstone does not form, like the Gabbro and Hypersthenite, deep mountain courses, but appears usually in a more subordinate form, either in small hills, or breaking forth between the layers of the Raipas group, and often covering the same in more or less plate- like masses. : d. Olivine rock—an independent rock—appears in two places in the Amt of Troms0, namely, on the high plateau immediately to the north of Tromsdalstind, and also at Skutvik lake, on the peninsula between Malangen and Balsfjord. In these two places it forms large isolated hillocks of more than 30 métres in height. The olivine stone is a beautiful rock of olive-green colour, inlaid with enstatite. It exhibits everywhere a transition to serpentine. Also, greenish tale may be found in the rock as a transformation product. 6. Serpentine appears in various points in the tract here noticed —partly as independent masses in isolated hillocks, and partly in connexion with the Gabbro as a transformation product. Chromate of iron is never observed in the serpentine here. 392 J. Starkie Gardner—On Cretaceous Aporrhaide. Of the masses here named there is some probability that the gneissoid granite, with the connected masses of purer granite, is a metamorphosed rock connected with the undoubtedly original sedi- mentary gneiss of the coast-tract, and thus formed at the same time as the stratified masses of the latter, and in the main under similar circumstances. On the other hand, the inland granite is presumably of irruptive origin. So considered, it is younger than the mica-slate group, the stratified masses of which it has pierced, but older than the slate- field of the Balsfjord, the stratified masses of which lie over the granite, often with a slight angle of inclination, without any sub- sequent intrusion being anywhere observable. The Gabbro and the hypersthenite break through the mica-slate group, and partly also the Balsfjord slate group, and are therefore younger than these, but older than the Raipas group. The green- stone which traverses the Raipas group is younger than it, but older than the Gaisa group. We have, therefore, here to distinguish between the older Gabbro and the younger greenstone (younger Gabbro). The age of the olivine rock cannot be accurately determined. It is probably older than the Tromsé mica-slate group. The following synoptical table will assist in elucidating this subject :— A.—STRATIFIED GROUPS, I. Primitive rock (probably Laurentian). II. Tromsé mica-slate group (probably Huronian). III. Balsfjord slate-field (younger Cambrian, probably Taconian). IV. The Alten and Kycenangen group (Raipas group), Silurian. V. Golda group (Gaisa system), perhaps Devonian. VI. Jura formation, a quite locally-appearing section at Andé, with coal layers (Ammonites, Belemnites, Pecten, etc.). VII. Quaternary formation :— a) Glacial period. 5 Post-glacial period. 1) Older section. tS} Younger section (the Gulf-stream period). B.—UNSTRATIFIED. I. Gneissoid granite (Laurentian). II. Inland granite (post-Huronian). III. Gabbro, hypersthenite (post-Taconian). IV. Greenstone (post-Silurian). V. Serpentine. VI. Olivine stone. I]—On tur CrEetTacnous APorRHAIDzZ. By J. Srarxige Garpner, F.G.S8. (PLATE XII.) (Continued from page 298.) When I commenced these notes at the beginning of this year, I expressed a regret that “I cannot include the Aptien and Neocomian species, but the collections at present open to me are too meagre to give anything like a complete account of them. . . . I have also reason to believe that many undescribed species exist from the Upper Geol. Mag.1875 NEW SERIES Decadell Vo 1 SRP Te L #2. S be ee S.S Cardinrez let 2 se. < 1 2 r Bh Five! ian a J. Starkie Gardner—On Cretaceous Aporrhaide. 393 Greensand, Chloritic-marl, and Chalk, in cabinets which I have not yet seen, and I should be obliged to any one who would inform me of them.” I have made an endeavour to supply this want of information, and in reply to the hope I expressed, that my attention might be directed to collections I had not seen, I had kindly sent to me specimens by Mr. C. J. Meyer, Mr. Jukes Brown, and Mr. E. B. Tawney. I have also been able to see the Cunnington collection, which a month or two ago was purchased by the Government, and lodged in the British and Jermyn Street Museums. Instead of confining myself, as I at first intended, to the Gault of Folkestone, I can also now include the Neocomian and the Grey Chalk, from which IJ have recently collected specimens myself. The result of the additional information I have thus gained is that I am now in the position to offer a different grouping from that which I have already suggested. My proposed grouping now is given on page 394. On DiIMoRPHOSOMA. When I first described the series of specimens of Aporrhais calcarata, Sby., I, in common with others, was led to consider them local varieties, which were the result of local. conditions of sea. This is a natural inference at first sight ; for while there is so great a similarity in the apical whorls, the invariably bicarinated body- whorl, the simple wing, and the more or less ribbed spire, which are common to all the specimens, it is not so apparent that the minor characters are constant. A suggestion of Mr. Meyer’s has led me to carefully inspect a large number of specimens, many of which he has kindly lent me himself. My information has also been extended by my recently finding three distinct species in the Chalk near Dover. Besides the easily recognizable constant characters mentioned above, the characters which I regarded as varietal I now find to be also constant through- out all the large number I have seen, and I therefore now consider them to have specific value. These characters are given seriatim further on. Still more important is the suggestion I am about to make that this group ought to be recognized as constituting a separate genus, possibly indeed it may have to be regarded as a separate family. I suggest this on the ground of what I suppose to be their mode of growth. Mode of Growth.—All specimens of the fry are seen to be keeled and without transverse ribs: with the third or fourth whorl a wing process is developed, and in most cases these whorls become ribbed. This early development of the wing and its persistence throughout the whole growth of the shell is a very unusual character. In the families of Strombide and Aporrhaide the wing is produced only after the shell has attained its adult stage, at which time the growth of the shell is confined to forming and thickening the wing in suc- cessive layers, instead of increasing the number of whorls. 394 J. Starkie Gardner—On Cretaceous Aporrhaide. ‘STIOUM 9} O} [oT[ered aav BIS pus s[I0x7 “yWeyO ‘ueru10909 \j— eased 4xou oes woMdiiosep Jog “Aqg ‘vpouw9j09 “= “PUOUTWOL) IY} UO UvIMOD0aNT OT} UI pa -quaseadea yng ‘puesueer zoddg pus yneg—qqo04'T pue sioyy jo mip = ATO UVIMLOI0a NT “H.lagdossrtag. Jo oUlvU dlIouAsqns sty dnois sty} 107 posodoad ayey, “I “qyUaoer ‘se709 -uapioo0 Fy kq poyuosardoy, “dnois ores 017} 0} sstojaq OTTO 9} Fo sewsofad “nd “yy yg ‘yAaUTyWOL) ETT} UO pue e1ay [NV oY} UI poasesqo ATuo ‘mou “qourstg CEU OT MSOF URIUL0N09 N—w pny Lod pue 2qwmoug weeded SIOJOVIVYO UL OFVIPOULLoJUT 9SUBY PUL SYIVUY ‘SLIOYM 9} 0} aswaasuv.4 SSUTYIVUL 94} IOJ asn [ squs W193} ONL s “SU0T *STIOTAL Ajeyeropout ZG Sey 04 qsrea4s ‘uo [TOTAL SBT 04 “SOT Ayuo syIoTA. Ajoyerepout G SV] OF “peamoor Ayuo pus ‘snonxep |,toya-Apoq 09 ‘Suoy At0A poamoor eatds ‘snonxep‘suoy| jo xedv 09 : SULA Jo rear) quoUyoRyy Vy (73 73 ce ce AyWo 4181p ou FO poulqtoy ‘SUOT OPCOAN FL, ‘SUT ‘ MOIIeU qutod dieys 8 ojut AT1O1.104 -sod pasuoy -oad ‘oyeapenb popuvdxe syIStp snonxey suo] Ara % SqLSTp poamooat snonxop. “SUT AN IO 9U0 Io MoIsuvdxe YIM JoyyIO ‘peonporg a2 a7nC “paqeLays ‘papeayy *S740y_ 4 ‘SULIodey puw poyoLmMy, andy ‘ZU0] F 10 ¢ ce (T} 20U0 UDY} 8Sa) te army wapun Le ‘TAO M O}VULT}[NUSA 9Y} JO YIPIM JY} JO Jel} 292M?2 waco SI YASUE, OsOYM oIIds & UvaUT J ‘Fuo) Aq 1 “[L0yM [LOYAL 4SBT Ho qsey, pus xedv | 4dooxo ‘armyns wo 4da0xe = weppry quasoid. skvaye T Ayyeraue3 =, -Areyuourpnt Ajwo soso 9ULOS UI ‘sapou 6 YIM sounry -oulos ‘4ULa8 -oid shee eicobel ty ee joret skoaye Ayyer9ues SOULIJOULOS @ 10 Z guou zg skemye 2 SQ KEP I ‘jeuvo IOLIeyUY We YIM ‘MOLTEN “SUIM Poye[IP YIM UWLOFISNT asnyqo xode 008 “UIT pout 08 suo] 008 wNTpeuL aTqe -msvout | uoyednd 40ul oOP-ot Lé qos aaa yortdg eu jo edeyg 3 13 guoys ** unrpau ** ‘VINOSOHd 8—9 “YOWIA GI—OL | “II Wor9§ PLT "T worag SIVHY OTS3 |) =woay 8 SO’ TAL “OVCIUL ‘Sod 9? |-OHLINYO “SHOU M | “SO NH9O ‘pouoyoryy ATpetoues pue ‘peystjog dy) vauuy -aunj4adpy —— poyeTno.ieqny pues peqqrit AT[e1oues ‘go8t ‘key “YCIVHULOdY *UuKVA *SUOT}LILSIP 9.0L ‘1204S — ATINY,| 10 SUMLOVUVH() TVUAENAY) J. Starkie Gardner— On Cretaceous Aporrhaide. 395 Gault. Neocomian Aptien Blackdown beds Upper Greensand. | Chalk Marl. ORNITHOPUS Fittoni, Forbes ......... globulata, Seeley ...... x histochila, Gard.... ..... x x SRE Moreausiana, Ord. ... x oligochila, Gard. ...... x pachysoma, Gard. ...... x TELUSA, SDY-.....eseeeeeee x x SDomieiisccecceesceceare te a ” 1 e100 e2eces vetoes TRIDACTYLUS cingulata, P.&R. ... x Griffithsii, Gard. ss... = Aporruais, Group I. glabra, Forbes ......... x Marginata, SDY. scorers x Mantelli, Gard. .......0. x subtuberculata, Gard.... x Parkinsont, Mant. ...... x xe Ks Cunningtoni, Gard. ... x BJD. acoooundonchbabecdo0d APoRRHAIS, Group Ty. carinella, P. & C. ...... carinata, Mant. ........- (Anarta) elongata, Sby. ....s0.0 maxima, PYICE .....0006 SYDo—— aooapoqo0no0n0 6000 ancylochila, Gard. ...... x calcarata, SbY. ......... x doratochila, Gard. ...... x xP kinelispira, Gard. ...... x neglecta, Tate ..........0 | x opeatochila, Gard. ... «. x pleurospira, Gard. ...... wey spathochila, Gard... x toxochila, Gard. ........ x vectiana, Gard. ........ x RJD coodsaocsuesoeso4ooes x le so DIMORPHOSOMA Their mode of growth seems to me to have been as follows, which is entirely different from that of any known recent shell. The animal had the power of absorbing the upper or dorsal layers of the wing at the same time that the ventral layers were deposited, in the same manner that the cowry removes the internal layers of its shell wall, and deposits new layers externally with its overlapping mantle. In support of the idea that the wing follows the aperture of the shell, and is continuously absorbed behind by the left edge of the mantle, I have seen in many of the specimens in Mr. Meyer’s collec- tion, that when small, oysters have grown on the back of the shell, so as to interfere with the possibility of the absorption; the old wing has been simply left behind, and an entirely new one developed. The figures which illustrate this are Pl. XII. Figs. 12, 12a, 126. The ribs were deposited after the formation of the whorl, by the inner margin of 396 J. Starkie Gardner—On Cretaceous Aporrhaide. the mantle, and possibly they were formed of the material absorbed from the wing. There is a case recorded by Mr. J. Gwyn Jeffreys which is of interest as throwing a side light on this subject. Speak- ing of Pleurotoma, he writes: ‘‘A specimen in my cabinet, from the body-whorl of which a large piece had been taken away at one time, exhibits a peculiar sort of repair; the renewed portion has no trace of longitudinal ribs, although the spiral sculpture is replaced.” ? If the growth was as I suggest, it follows that the ribs are not homologous with the varical ribs of Scalaria. Mr. Reeve and others have long since drawn attention to the solvent properties of the juices of Cypreea, Conus, etc.; whilst Murex and other varicose Gasteropoda have the power of removing portions of the varices or spines of the last formed whorl], which would obstruct the growth of the over- lapping succeeding whorl. Many Cerithia, which in their younger stages have dilated lips or recurved canals, surely must possess this power, and this remark also applies to Persona, Cassis, Typhis, Ricinula, ete. A different opinion is, however, held by Mr. Gwyn Jeffreys, who, for no reason, as far as I can find, that he has given, objects to this view.” In the present case we must suppose the mantle to have been spread as in Sycotypus (Pyrula) ficus, but still conforming to the shape of the shell, which enabled it to absorb from the dorsal side. It seems doubtful whether the form of any of the recent winged families would enable them to produce their shells in this manner. Genus Dimorrnosoma,? Gardner. Shell fusiform, with dilated wing, spire elongated; always pos- sessing two, rarely three keels, which are generally obscured, except on the apex and last whorls, by transverse ribbing; whorls numerous, usually finely striated, sometimes smooth, either keeled or ribbed transversely ; apex more or less obtuse; aperture narrow; with a long or short canal in front ; outer lip expanded into a simple grooved digitation. The wing attached to the last two whorls only. DimoRPHOsOMA KINCLISPIRA,‘ Gardner. Neocomian. Pl. XII. Figs. 1, la. Shell elongated ; apex obtuse; whorls 7 or 8, inflated and rounded, ~ ornamented by numerous longitudinal oblique, flexuous ribs, extend- ing to the sutures. The ribs vary in number and prominence, there being about twenty and fourteen respectively on the penultimate whorls of the two known specimens; they are crossed by numerous distinct, irregular raised spiral strie, which are seen with an inch power to be angulated. The upper side of the last whorl is destitute of ribs, but has a very salient median keel, and a second subordinate keel in front; one of the spiral lines between the keels is more dis- tinct than the rest. The canal appears to have been long; the margin of the outer lip in front of the wing is angulated; the wing is simple, strong and ridge-like, projected slightly downwards. 1 J. G. Jeffreys, vol. iv. p. 397. 2 Ibid. pp. 306, 4038. 3 Two-shaped body. 4 KvykAls, a lattice. J. Starkie Gardner—On Cretaceous Aporrhaide. 397 Found in the Cracker rocks at Atherfield.. Described from two specimens in the Jermyn Street Museum. DIMoORPHOSOMA ANCYLOCHILA,! Gardner. Neocomian. Pl. XII. Figs. 2, 2a. Shell elongated; whorls 6 or 7, very angulated, their median keel tuberculated, sutural keel plain, intervals smooth, without spiral strie. The last whorl possesses two angular keels; the posterior considerably predominating, and the anterior being the sutural keel of the spire ; the greater keel is continued into the wing. The wing is narrow, simple, thick and angular like a roof-ridge ; for some dis- tance it is at right angles to the axis of the spire, and then curves gradually upwards, slightly expanding at the point of curvature. Found in the Cracker rocks at Atherfield. Described from a single specimen in the Jermyn Street Museum. DimoRPHOSOMA PLEUROSPIRA,? Gardner. Neocomian. Pl. XII. Figs. 38, 3a, 4. Shell elongated; whorls 7 or 8, last two rounded, upper whorls angulated, possessing three keels. On the upper whorls the first keel is strong, salient, and tuberculated, with 9 or 10 tubercles on each whorl; the second keel is indistinct; the third is well marked and sutural; on the penultimate whorl the two keels assume about equal prominence, the upper one being still faintly tuberculated; the last whorl has all three keels well developed, the median one being least prominent. The wing appears to be strong, and projected slightly downward. ‘The shell is unusually destitute of spiral striee. Under the microscope faint transverse structural lines are visible. This species is found in the Lower Greensand at Peasemarsh. Mr. C. J. A. Me¥er has several specimens in his collection, the most perfect of which are selected for illustration. DimorpHosoMA VECTIANA, Gardner. Aptien. Pl. XII. Figs. 5, 6, 7. (Insula Vectis, Isle of Wight.) Shell elongated; whorls 6 or 7, angulated; upper keel replaced by rather produced, elongated tubercles, except on the last whorl; sutural keel smooth and distinct ; last whorl with two salient keels, rather close together, the posterior being the more prominent ; spiral striz none, except on the dorsal side of the anterior canal; the wing is simple and curved upward, elongate, and narrow; anterior canal moderately long. Found at Shanklin, in the Folkestone beds of the Lower Green- sand. Mr. Meyer has kindly shown me about a dozen specimens in his collection, three of which are selected for figuring. Fig. 7 is from a cast only, the shell having broken away; the canal and wing process are, however, well preserved. DimorpHosoma sp.? Aptien. Pl. XII. Fig. 8. A cast of an Aptien species with expanded wing is represented at Fig. 8. It is probably distinct from that described above, and is from the same locality. 1 @ykvals, a hook. 2 amAevpa, a rib. 398 J. Starkie Gardner—On Cretaceous Aporrhaide. DimorpHosoma cCALCARATA, Sby. Blackdown beds. Pl. V. Figs. 7, Ta, 15, lda; Pl. XII. Figs. 9, 9a, 10, 11, 12, 120, 120. Shell elongated, slightly pupzform ; whorls 7 or 8, rounded but slightly flattened; keels totally obscured by ribbing, except on the dorsal side of the last whorl and on the apex; ribs oblique, flexuous, thick and regular, with a tendency to form varices, 17 or 18 on the penultimate whorl; apex minute, obtuse with rounded, smooth whorls, carinated at their base. Body-whorl distinctly striated, with a strong rounded posterior keel and subordinate anterior keel, one of the strize below the anterior keel being more prominent than the rest; no ribs on the dorsal, but ribbed on the ventral side. The principal keel is continued on to the wing in the form of a ridge ending in a sharp point. The wing is simple and more expanded than in the other associated Blackdown species, projected at first at right angles to the axis of the spire, and then curving rather abruptly upward, terminates in a point three-fourths of the height of the spire; margin entire, region above the rib narrow and thickened. Outer lip ex- panded into the wing, thickened internally into a second. triangular spoon-shaped lip, smooth; inner lip thick; aperture narrow; canal short. This species is that originally described by Sowerby. Its history is given at page 129 of this Magazine. It is found at Blackdown. Mr. Meyer, who has kindly given me the opportunity of examining the many hundreds of specimens in his collection, informs me that this shell is about five times more numerous than that next described, with which it is found associated. It is just possible that this may be the male, and D. neglecta the female, as in Fusus, an allied family. Mr. Gwyn Jeffreys remarks: ‘Of many hundreds of specimens which I have examined, the males were more numerous than the females.” } DimorPHosoMa NEGLECTA, Tate. Blackdown. PI. V. Figs. 8, 8a, 9, 16; Pl. XII. Figs. 18, 13a, 14, 15. Shell resembling in form that of the species last described ; whorls 7 or 8, ventricose, slightly angulate, keels visible on all except those near the apex ; region above the keel nearly smooth or with spiral lines; that below marked by fine straight oblique ribs, which do not quite reach to the suture, but impress the median keel; they are crossed by 38 or 4 strong striz, and there are 2 or 3 more striz nearer the suture. The number of these spiral striz and the prominence of the ribbing are most variable, the ribs being sometimes scarcely present, but generally most strongly developed on the penultimate whorl; they may usually be seen on the dorsal side of the last whorl in the form of small oblique tuberculations crossing the keel. The wing is at first constricted, notched, with a single tooth in the notch, and then expanded and curved upward—never having the triangulate inner thickening; in one specimen figured, Pl. V. Fig. 16, it is bifurcate. 1 J. G. Jeffreys, vol. iv. p. 337. J. Starkie Gardner—On Cretaceous Aporrhaide. 399 Tt is found at Blackdown, where it is less common than D. calcarata. An examination of a very large series of specimens fails to show any decided intermediate form between the two species. Mr. R. Tate, in the Geol. and Nat. Hist. Repertory, Sept. 1865, separated it as a variety of Aporrhais calcarata, under the name of A. neglecta. DimorpHosomaA ToxocHina,' Gardner. Gault. Pl. V. Figs. 10, 12. Shell elongated ; whorls 7 or 8, rounded, inflated; keels obliterated, except on apical and body-whorls, other whorls ribbed; ribs pro- nounced, more or less oblique and flexuous, about a dozen on each revolution ; sutures keeled ; apex rather obtuse, composed of three smooth angulated whorls, with a strong keel rather anterior to their centre. The last whorl is striated, and has two keels, the posterior being the more prominent; on the ventral side the region above the posterior keel is ribbed. The inner lip is incrusted round the aperture, the margin of the incrustation being sharply defined ; the outer lip is prolonged into a very long, curved, narrow, and simple wing, grooved ventrally, carinated above. The wing is straight for a quarter of an inch, and is then curved rather suddenly upward, exceeding the spire in length. Anterior canal long and nearly straight ; aperture narrow. ‘This shell is more elongated than the Lower Gault species. It is found in the beds immediately above and below the mottled bed in the Folkestone Gault, where it is rare. The beds are numbered 5 and 7 by Mr. F. G. H. Price. It is more elongate and slender than the Lower Gault species. DiIMoRPHOSOMA DORATOCHILA,? Gardner. Gault. Shell moderately elongated ; whorls 6, sometimes 7, convex, finely and distinctly striated ; keels obliterated except on apical and body- whorls ; the third whorl is both keeled and ribbed, the other whorls are ornamented by numerous oblique and flexuous ribs; sutures raised, sometimes hidden; apex formed of three broad and very obtuse angulated whorls, which are smooth, with a strong median keel. The body-whorl has two keels, the posterior being the more prominent; the posterior region is slightly ribbed ventrally; the whorl is strongly striated, especially that part anterior to the keels. The wing is long, narrow, simple, forming an acute ridge above; it is curved gradually upward, and terminates in a sharp point. The aperture is narrow, and is incrusted immediately round the colu- mellar lip ; the outer lip is toothed ; the wing is applied to the last whorl only; the anterior canal is long and straight. The history of this species is given at page 129, it is confined to about a single foot of the Gault of Folkestone (bed 2 in Mr. Price’s paper), and has not been met with elsewhere. DIMoRPHOSOMA OPEATOCHILA,? Gardner. Grey Chalk. Pl. VII. Fig. 9. Shell very elongated; whorls rounded, probably nine; striated ; keels entirely obliterated, except on the body-whorl; ribs ten or eleven on each whorl, reaching to the sutures. Last whorl having 1 rdéov, a bow. 2 Sdpu, a spear. 3 Omeds, an awl. 400 VJ. Starkie Gardner—On Cretaceous Aporrhaide. two keels of nearly equal prominence, striated between. Wing simple, long, narrow, awl-shaped; aperture narrow; anterior canal short, outer lip sinuous. This shell differs from the figures of R. calcarata, composita, and stenoptera of German authors in the length of the wing and want of ribs crossing the keels on the last whorls. It was found in the cast bed of the Grey Chalk, at Lyddenspout, between Folkestone and Dover, and is described from a single specimen. DimorPHosoMa SPaTHocHILA,' Gardner. Grey Chalk, Pl. VII. Fig. 10. Shell elongated, turreted, whorls with few very prominent oblique ribs, body-whorl with two keels; wing simple, at first constricted, then widening into a bladebone-shaped expansion; the channel in the wing is nearly straight, and forms an angle of 70° with the axis of the spire ; the wing was probably twice the length of the speci- men figured, and was pointed as usual in this group. Aperture narrow, anterior canal short, and connected with the wing by an expanded outer lip, with sinuous margin. The form of the canal and the connecting lip is similar to that in D. opeatochila, and is an unusual one in the group. Found with the species last described, and described from a single specimen. EXPLANATION OF PLATE XII. Fie. 1.—Dimorphosoma kinclispira, Gardner. Natural size. Neocomian, Atherfield. From the Jermyn Street Museum. Fic. la.—D. kinelispira. Enlarged twice. ; Fie. 2.—D. ancylochila, Gardner. From the Jermyn Street Museum, Atherfield. Fie. 2a.—D. ancylochila. Enlarged twice. Fic. 3.—D. pleurospira, Gardner. Neocomian, Peasemarsh. Mr. Meyer. Fic. 3a.—D. pleurospira. Enlarged twice. Fic. 4.—Another specimen. Fic. 5.—D. vectiana, Gardner. a... . 45° 52! 100,101 = 49° 4’ ee 48° 49’ 110,110 = About 88° dave’ 88° 16’ 110,101 = Se 30al peter “68° 24’ The specific gravity of the mineral is 3-198, the hardness 5-6, and the chemical composition : Oxygen. Silicic acid... BED: * — scoccbe 29-706 Magnesia... PRETO) soo00e 9-119 Tron protoxide...... 20:04 9 ences 4564 > 14:059 ime we eee ROUGE eo Gets 0:376 100-358 These numbers agree very closely with those required by the formula (2 Mg 4 Fe) SiO,, and show the mineral to be richer in iron than the bronzite of the Breitenbach siderolite. A portion of the meteorite was analysed in its entirety with the following results : Oxygen. Siliciaciay eae e TCWG aR, acer 28-602 Magnesia —_....... PEEBYAD 9 coocee 9-328 Iron protoxide...... QO AUB elon 4°550 ) 14°305 BIMOR Sade. a W495 cede 0°427 Chromite ...... 1-029 99-949 These per-centages differ to so small an extent from those yielded by the analysis of the picked crystals, that we arrive at the con- clusion that both ingredients have the same composition, and find in the Manegaum stone an instance of a meteoric rock consisting of a single silicate. The Ibbenbiihren meteorite (1870, June 17th) has since been shown by Vom Rath (see page 71) to be similarly con- stituted. A very minute amount of meteoric iron, far too small for isolation and analysis, occurs in the Manegaum stone. Found 1846.—Tula, Netschaevo, Russia. This remarkable mass of iron, which encloses a number of angular fragments of rocky material and resembles a true breccia, was stated by Auerbach to contain but little nickel. Rammelsberg now finds as the result of two analyses, conducted according to different methods, that the per-centage of this metal (and cobalt) is 10-24 and 9-84, or about four times the amount detected by the earlier observer. 1 C. Rammelsberg. Monatsber. Ak, Wiss. Berlin, 1870, Ixx. 444. 404 Dr, Walter Flight—Mistory of Meteorites. 1847, February 25th.—Hartford, Linn Co., Iowa.’ This meteorite was originally examined by Shepard (Report on American Meteorites, 1848, page 37), who states that it consists of 83 per cent. of a silicate to which he gives the name of ‘ howardite’ (an iron-magnesium silicate with the oxygen ratio of RO: Si0,=1: 3°3), about 10 per cent. of nickel-iron and 5 per cent. of magnetic pyrites. Shepard moreover asserts in his paper that this extremely acid silicate fuses easily before the blowpipe, and gelatinises with warm dilute acid. Not a little astonished that a silicate of this form should possess such properties, Rammelsberg undertook an examin- ation of this meteorite, which he finds to possess the following composition : Nickel-iron gee tee 10°54 Troilite ... Bae as 6°37 Soluble silicate ... oie 41°85 Insoluble silicate ee 41°24 100-00 The nickel-iron alloy consists of Iron= 89:75; nickel=10:25; Total=100-00. and the composition of the two portions of silicate separated by the action of acid and sodium carbonate was as follows: Si0, AhO; FeO Mg0 (CaO NaO K,O A. Soluble ...388°80 — 21°31 39°89 — — — = 100-00 B. Insoluble ..65°08 4°86 13°58 22°70 2°85 0:93 trace = 100-00 The oxygen per-centages of A clearly indicate the presence of an olivine in which the ratio of Mg: Fe is 3:1, or the same as that of the variety of this silicate which occurs in the Hainholz siderolite. The insoluble portion, about equal in amount to the above, appears to consist of a bronzite (or bronzite mixed with a little augite), in which Mg: Fe: Ca is as 12:4:1; the ratio of iron to magnesium in the two minerals forming the chief ingredients of this meteorite is therefore the same. Rammelsberg’s results differ altogether from those given by Shepard, and indicate the presence in this stone of those minerals only which are frequently met with in meteorites. ‘Howardite’ has not been identified as a mineral species in any rock, terrestrial or meteoric. 1847, July 14th— Braunau (Hauptmannsdorf and Ziegelshlag), Bohemia.’ In a memoir on the crystalline characters of iron, and especially of meteoric iron, T’schermak describes the structure of the specimens of Braunau iron preserved in the Vienna Collection. One piece exhibits the cleavage planes of the cube, as well as other smaller faces on the edges and corners of the cube; the angles which these faces form with those of the cube are 70° and 48, corresponding evidently with those enclosed between the faces of the triakis- 1 C. Rammelsberg. Monatsber. Ak. Wiss. Berlin, 1870, lxx. 457. 2G. Tschermak. Sitzber. Ak. Wiss. Wren, 1874, Nov.-Heit, lxx. Dr. Walter Flight—History of Meteorites. 405 octahedron (221) and the cubic faces, viz. 70° 31’ and 48° 11’. Faces were noticed in the following positions : 921, #12, 122, 221, 212, 297 the other six directions, although present, could not be traced on the specimen which the author examined. Occasionally solid angles or corners are protruded from the cleavage planes with faces at right angles to each other and corresponding, as regards their position to the cube, with the directions (221). Little step-like markings, such as are seen on artificial iron, and fine lines, evidently sections of thin plates, are likewise observed in positions that correspond with one or other face of the triakis-octahedron (221). ‘T'schermak shows that the development of these faces is due to twinning, not by con- tact, but by interpenetration, the normal on 111 being the axis of twinning. Such twinning is met with on crystals of fluor-spar. By etching the Braunau iron two varieties of figures are developed: with a moderate use of the corroding reagent an orientated sheen is developed, the fine texture exhibiting what von Haidinger termed crystalline damaskining (see page 75). As the author showed in the case of the Ilimaé iron this appearance is due to slight depressions of the surface; they are, in fact, little cubical hollows, the sides of which are parallel to the cleavage faces. A second curious feature brought to notice by etching are little furrows which make their appearance on those parts of the cleavage-face where the fine lines were previously seen, lines which owe their origin to the plates parallel to (221). The twin-lamelle therefore are more readily acted upon than the mass of the metal. On dissolving this iron in dilute nitric acid a residue remains which consists of fine yellow metallic needles and excessively thin yellow plates; occasionally particles are met with exhibiting every stage of transition from one to the other of these forms. The plates are not unfrequently broken through, or imperfectly developed, in the manner with which we are familiar in crystals of some varieties of specular iron from volcanic localities. The needles, as Rose has already shown, lie parallel to the edges of the cleavage-cube. . Tschermak believes both plates and needles to have the same com- position, to be in fact schreibersite. He was not able to determine the crystalline form of this meteoric mineral with the material pro- vided by this meteorite, but he is of opinion that it will be found to be either tetragonal or rhombic. 1850, November 30th.—Shalka, Bancoorah, Bengal. The mineral characters of this meteorite were first described by von Haidinger and G. Rose, and the chemical investigation under- taken by C. von Hauer, who found the silicates, when analysed in the mass, to give numbers the oxygen ratios of which were: RO to SiO, as 1: 2-485. While von Haidinger regarded the chief constituent of the meteorite to be a silicate to which he gave the name of 1 C. Rammelsberg. Monatsber. Ak. Wiss. Berlin, 1870, lxx. 314.—N. Story- Maskelyne. Philosophical Transactions, 1871, clxi. 359. 406 Dr. Walter Flight—History of Meteorites. ‘piddingtonite,’ G. Rose considered it to be composed of olivine _and another mineral ‘shepardite,’ which has now been found to be as hypothetical a species as ‘ piddingtonite.’ Rammelsberg during a recent examination of the meteorite determined it to consist of: IBEOZ1G) Me teeeey sei Wesel ose seatnis<= COULO Olivine sf ies eds kee DEG Reardecd: 1092 Chromite Wocsr) ieee dheeee, ace bom esen iO, 99-46 the separation with acid and sodium carbonate yielding the following numbers : Sid, FeO MgO CaO Na,O Chromite. A. Soluble... 35°17 35°30 29:03 — — — = 100-00 B. Insoluble ... 55°55 1653 27°73 0:09 0°92 038 = 101715 Rammelsberg therefore finds this meteorite to have a much more simple composition than the earlier investigations, and to consist mainly of a bronzite and a few per cent. of olivine, in each of which the Fe is to Mg as 1: 3. According to the results given in Maskelyne’s paper, the constitution of this meteorite, or of the portion of it examined in the British Museum Laboratory, appears to be yet more simple. A small amount of the débris of the stone was found to possess the following com- position : . Oxygen. SHUTS EXBTELA = Goo acs coo ato AOU ang nag CHI Y/ Tiron pO LOI ep eeuntasate Mees Wace) O40 0 Meee mane 4-236 WHYS, Goa son bacco no) IID) cca co 6:254 JAIN G50 Goa Goo coo non ooo PME aha 00 0°632 (CURDS G55 ono ood oon, on NOL to, coe = Bi A mottled grey-coloured mineral, forming the chief constituent of the meteorite, was twice submitted to analysis with the following results : I. Oxygen. II. Oxygen. Silicic acid ...... PPO” Sac00c PHPIG) banssoaoc S2e20) ween 28-120 Tron protoxide... 21°8638 ...... 4°859 ......... POO soncce 5:109 Magnesia......... DAL266) Peiecn OO” tsenneein 24:°085 ...... 9-630 MLIMC Ri caseedeee 0°502 ...... VEL SoM S a aed Did lad Cecio — Chromiteyo...0-- 0-643 aie Ten) ub yaeeaiecce _ — 100-105 99-802 These numbers correspond with the formula (4 Mg 4 Fe) SiO, which is identical with the bronzite of the Manegaum meteorite (which see). These results, it will be seen, do not indicate the presence of an olivine. To check them, two weighed portions of the mineral were subjected to the action of hydrochloric acid and sulphuric acid respectively, with subsequent treatment with sodium carbonate in each case, whereby the following constituents were removed : he Oxygen. II. Oxygen. Silicic acid ...... 1507) cect. O:804i Preece: SOLO! Canna 2°080 Iron protoxide... 0974 ...... ONG ~ Goooaoece IS(OD ecaaes 0-399 Magnesia......... WOH. coooce 0°4238 ee WS lilo Gasien's 0°760 Dr. Walter Flight—Mstory of Meteorites. 407 The slight excess of iron oxide found in each case is doubtless due to the presence of a little unseparated nickel-iron. These results confirm the above analysis and fail to indicate the presence of olivine in this meteorite. Found 1850.—Ruff’s Mountain, Lexington Co., S. Carolina.’ In an examination of this large block of meteoric iron Shepard detected the presence of only 3:12 per cent. of nickel. By employing two more refined methods of analysis, Rammelsberg now finds: If, II. Mean. INickeliricercs senses McGOieeedac BAGS ssecec 8°62 which is still within the limit that I find to obtain in those instances where an iron exhibits Widmannstittian figures. (Compare with the list on page 80.) . 1852, September 4th_—_Mezo-Madaraz, Transylvania.’ Allusion has already been made to Rammelsberg’s recent investi- gation of this meteorite (see page 25). His previous researches on the constitution of the meteorites of Kleinwenden, Pultusk, Rich- mond, and Linn Co., Iowa, had proved them to consist of a mixture of olivine and bronzite, and in his review of the additions made during the last few years to our knowledge of these cosmical masses,* he had demonstrated that of the fifty chondritic meteorites which had up to that time been submitted to analysis, the greater part yielded a like result. Certain among the meteorites, however, did not appear to come under this rule; among them is the one mentioned above which had been analysed by Atkinson,? who found no iron protoxide in the insoluble portion, and determined the part broken up by the acid to be a trisilicate. The author was led to analyse this stone afresh, and he has arrived at the following results : . Nickel-iron ... alte oan 9°79 Troilite ie Bee tee 6:24 Chromite his aa ate 0-80 Soluble silicate his ede 42°83 Insoluble silicate ee eee 40°34 100-00 The nickel-iron, which has the composition indicated by the formula Fe,Ni, yielded the following numbers: Tron = 83°25; Nickel (cobalt) = 16°75. Total 100-00 and the silicates those given below : 810, AlO; FeO MnO NiO MgO CaO NaO0 A. Soluble 36:61 2:19 22°82 0-42 0:14 35°49 0:60 1:02 = 99:29 B. Insoluble 52°02 6:08 18°27 — — 21°85 3°74 C. Total 44:24 4:10 18:25 0-22 0:07 28:98 2:02 1 C. Rammelsberg. Monatsber. Ak. Wiss. Berlin, 1870, xx. 444. 2 ©. Rammelsberg. Zeitschrift Deutsch. Geol. Gesell. Berlin, 1871, xxiii. 734. 3 C. Rammelsberg. Monatsher. Ak. Wiss. Berlin, 1870, lxx. 440. 4 C. Rammelsberg. Die Chemische Natur der Meteoriten. Abhandl. Ak. Wiss. Berlin, 1870, 78. 5 KE. Atkinson. Jour. Prakt. Chem., 1856, 357; Phil. Mag., xi. 141. bo 09 408 Dr. Walter Flight—History of Meteorites. The soluble part is an olivine of the same composition, 3 Mg, SiO + Fe, SiO,, as that met with in the meteorites of Hainholz, Borkut, St. Mesmin, Muddoor, Shergotty, etc.; the insoluble portion appears to be a bronzite, in which the bases Ca: Fe: Mg=1:3:9, accord with those of the variety of this mineral which occurs in the Chantonnay stone. The Mezé-Madaraz meteorite therefore belongs to the large class of chondritic masses above mentioned. 1852, December 2nd.— Busti, between Goruckptr and Fyzabad, India. [lLat. 26° 45’ N.; Long. 82° 42’ E. |’ With a view to obtain some more satisfactory means of dealing with the aggregates of mixed and minute minerals, which constitute meteoric rock, the author sought the aid of the microscope, having in the first place sections of small fragments cut from the meteorites so as to be transparent. By studying and comparing such sections one learns that a meteorite has passed through changes, and that it has had a history of which some of the facts are written in legible characters on the meteorite itself; and one finds that it is not difficult roughly to classify meteorites according to the varieties of their | structure. One also recognizes constantly recurring minerals; but the method affords no means of determining what these are. Hven the employment of polarized light, so invaluable where a crystal of which the crystallographic orientation is at all known is examined with it, fails, except in rare cases, to indicate with certainty even the system to which such minute crystals belong. It was found that the only satisfactory way of dealing with the problem was by employing the microscope, chiefly as a means of selecting and assorting out of the bruised débris of a part-of a meteorite the various minerals that compose it, and then investigating each separately by means of the goniometer and by analysis—finally recurring to the microscopic sections to identify and recognize the minerals so investigated. In the memoir mentioned below the author publishes the results of the former part of this inquiry. It is obvious that the amount of each mineral which can be so obtained is necessarily small, as only very small amounts of the meteorite could be spared for the purpose. On this account one has to operate with the greatest caution in perform- ing the analysis of such minerals, and the desirableness of determining the silica with more precision than usually is the case in operations on such minute quantities of a silicate suggested a process which, after several experiments had been conducted with a view to perfect- ing it, assumed a definite form. The method, which essentially consists in the separation of the silicic acid from the bases by dis- tillation with hydrofluoric acid, whereby the operator is enabled to proceed to the estimation of the whole of the constituents of any silicate in one and the same portion, will be described in detail later on with other new methods of analysis. 1 N. Story-Maskelyne. Proc. Royal Society, xviii. 146. Philosophical Trans- actions, clx. 189. (See also Abstract in Nature, i. 382.)—A preliminary notice of this meteorite appeared in the Brit. Assoc. Report, 1862, “ Notices and Abstracts.” Appendix ii. 190. Dr. Walter Flight—History of Meteorites. 409 The first meteorite investigated on the principles here laid down was the remarkable stone single fell at Busti, in India, at the above date. The fall, which took place from a cloudless sky at 10°10 a.m., was attended with an explosion, louder than a clap of thunder and last- ing three to four minutes, and must have occurred about the time the stone passed the longitude of Goruckptr. The meteorite, which weighs about 38 lbs., consists for the most part of the mineral enstatite ; at one end, nomen are embedded a number of chestnut-brown spherules, in which again were detected minute octahedra having the lustre and colour of gold. These two minerals seem scarcely to have been affected by the heat that fused the silicates surrounding and encrusting them. The brown spherules are calcium (magnesium) monosulphide, and have been named by the author ‘Oldhamite’; their outer surface is generally coated with calcium sulphate. This mineral cleaves with equal facility in three directions which give normal angles averaging 89° 57’, and are no doubt 90°. Its system, therefore, is cubic; in polarized light it is seen to be devoid of double refraction. The specific gravity is 2°58 and the hardness 3:5—4:0. With boiling water it yields calcium polysulphides, and in acid it readily dissolves with solution of hydrogen sulphide. The composition of these spherules was found to be: if, II. -, { Calcium monosulphide O00 cot 89-369 90°244 wieleaiiiae Magnesium monosulphide ... ase 3°246 3°264 Gypsum. ve noo 200 BE 200 3961 4°189 Calcium carbonate... 200 900 500 ae 3434 — Troilite ... 000 not coc cee _ 2°303 100-000 100-000 The presence of such a sulphide in a meteorite shows that the con- ditions under which the ingredients of the rock took their present form are unlike those met with in our globe; water and oxygen must have alike been absent. The existence of iron in a state of minute division, as often found in meteorites, leads to a similar con- clusion. But if the conditions necessary for the formation of pure calcium sulphide be borne in mind, the evidence imported into this inquiry by the Busti aerolite seems further to point to the presence of a reducing agent during the formation of its constituent minerals ; whilst the crystalline structure of the oldhamite and of the mineral ‘next described must certainly have been the result of fusion at an enormously high temperature. The detection of hydrogen in meteoric iron by Graham, and more recently by other observers, tends to confirm the probability of the presence of such a reducing agent. “‘Osbornite”’ is the name given by the author to golden-yellow microscopic octahedra embedded in the oldhamite. These minute — crystals gave the following angles: Regular e octahedron. 111,111 = 70° 27’ and 70° 37’ 70° 31’ Wii, WIE = 109° 31’ 109° 28’ 111, 111 69° 58’ 410 Dr. Walter Flight—History of Meteorites. This mineral withstands the action of strong acids, is unchanged when fused with potassium carbonate, and possibly when heated with the chlorate ; heated in dry chlorine it glowed for a few seconds, lost its metallic lustre, and left a residue which soon began to deliquesce. The amount, about 0-002 gramme, was too small for anything but a qualitative examination, which showed it to consist of calcium, sulphur, and an element which gives the reactions of titanium or zirconium, probably the former, in some singularly stable state of combination. By heating zirconium to an intense heat with lime and aluminium, Mallet? obtained a golden-yellow incrustation, cubic in form, unattacked by the strongest acids, and possibly analogous in its nature to. osbornite. The next mineral described is an augite of a pale violet-grey colour, intimately mixed with another silicate presently to be de- scribed ; it belongs to the oblique system, the measurements yield- ing the following approximate values: Diopside. 001,100 = About 75° 30’ "ie Ey 061,110 = Sa SIe 79° 29° 110,100 = 45° 54’ to 47° 26’ 46° 27’ 110,110 = &° 8’ to 86° 20’ 87° 5 100, 111? = 58° 25’ to 54° 15’ 53° 50° 001,110 = 100° 81’ 100° 57’ The plane containing the optic axes is perpendicular to the edge [100,001], and the optical character in the centre of the field is negative. When looked through in any direction parallel to the zone circle [001,010], the crystals show aremarkable dichroism; the plane 100 presents a somewhat facile cleavage, and is also conspicuous for a remarkable metallic lustre, recalling that seen on some kinds of diallage, but of a fine golden hue. The author is of opinion that osbornite may permeate the augite in minute interlaminated layers of sufficient thinness to be transparent. Two analyses of this mineral gave the following numbers: Ik II. (2 Mg 2 Ca) Si0, Silicic acid ... ... 55°389 900 55°894 eaeees 56°604 Magnesia ... ... 23°621 ooo 23-0360 05 vases 23°585 Inne) 5 cog” boo, AUD 200 19°942 cenoae 19°811 Iron oxide ... ... 0°780 noc OOO) sho0s ° = SHG Gag" Gao | don) 1 ORES on [0°554] — seeee = Hitihiaseen evel) soe uteace S00 [iixe'cell eeieseese _ 100°364 99:435 100-000 The iron oxide contains some of the titanoid metal met with in osbornite. In terrestrial varieties of augite the calcium is usually in excess of the magnesium. ‘The mineral was somewhat soluble in acid, the action, however, was found to be simply that of a solvent. While the augite is present in greatest quantity in the area containing the calcium sulphide, it is met with in other parts of the stone; and associated with it everywhere, and forming the mass of 1 See researches on the presence of titanium vapour in the solar prominences and chromosphere, by C. A. Young. Amer. Jour. Sc., 1871, ii. 335. 2 J. W. Mallet. Amer. Jour. Sc., 1856, xxvill. 346. Dr. Walter Flight—History of Meteorites. 411 the stone, is another silicate, which proved to be an enstatite like that of the meteorite of Bishopville (1843, March 25th). It presents the appearance of a number of more or less fissured erystals, with different degrees of transparency, and with a more or less symmetrical polygonal outline, embedded in a magma of fine-grained silicate. Three varieties of this mineral are described: I). a dark- grey glistening crystalline substance, tabular in form, very opaque, and presenting cleavages indistinctly marking the faces of a prism for which the mean of several measurements gave an angle of {ests II). a colourless transparent variety, which is rare; and III). a grey semi-transparent splintery mineral in very composite fragments. The following additional measurements were made of this mineral : Bee eee aoeree 100, 110 = About 46° ou) dae 110, 110 = 87° 10’ to 88° 0’ ANB Mincne wermpemitsts dk oy. 100, 101 = 41° 34’ pak ar Ale ee 010, O11? = About 40° Bas) MRCS uve 4 ORM The planes 100 and 110 are cleavages. 'The chemical examination of these three varieties yielded the following per-centage numbers: I. II. III. Mg0,S8i02 (sume ean =) Silicie acid ... 57°597 58°437 57:037 57°961 57°754 60-000 Magnesia «. 40°640 38°942 40°574 39°026 388°397 40:000 Lime SoC ORO — 1:677 2°294 1°524 2°376 —_— Tron oxide spo LE 1:177 0°867 0:154 0-423 — ovashemessmieer 0°394 0:332 — 0°569 0:569 _— Nodaresuecetie te wiOG0G 0°357 _ 0-680 0-657 IRIE, 665 6 = — — 0-016 100-975 100:922 100-772 99-914 1007192 100-000 By acid each variety was acted upon to some extent; the action, however, was found to be simply that of a solvent. The meteorite also contains a little nickel-iron and schreibersite, having the composition : 2 . Tron Roe ACO DAC 94-949 or | INickele. Bester cen eee, 3-849 Tron as ase uah 0°884 Schreibersite Nickel ... ies eae 0°234 Phosphorus coc Doc 0-084 100-000 a very small quantity of troilite, and a small but appreciable amount of chromite, a crystal of which gave the solid angle of a regular octahedron. . The memoir is illustrated with two plates, the one showing very carefully drawn microscopic sections of the augite and enstatite, the other views of the stone and a section of the nodule containing the oldhamite spherules. Plate XI. is an endeavour to reproduce, by the chromolithographic process, a very elaborate water-colour sketch of this interesting stone prepared by my friend Mr. Edward Fielding. On the upper portion of the section towards the right hand is seen the area where the spherules of the calcium sulphide and some large ~ crystals of the augite are situated; below is a pepita of nickel-iron, the occasional white patches indicating large crystals of enstatite. 412 G. Poulett Scrope—Note on Mr. R. Mallet. Found 1853.—Tazewell, Claiborne Co., Tennessee." This meteorite was one of those selected by the author for. his investigation with the spectroscope of the gases occluded by meteoric iron (see also the meteorites of Red River, Texas, and Arva, Hungary). It is noted for the large amount of nickel, 14°62 per cent., which it contains; it had been examined by J. L. Smith,? who found no carbon in it. As in the case of the Texas meteorite, this iron appears to evolve gas at ordinary temperatures ; the red and green hydrogen lines were brilliant, while the bands of carbon were not noticed. When heat was applied, the spectrum showed the hydrogen lines very brilliantly, and the four chief carbon bands were strongly marked. As the tension of the gas decreased, the hydrogen lines became relatively brighter and the carbon bands grew narrower ; and at 1 mm. these bands were still prominent, while some narrow bands apparently belonging to nitrogen were observed. They differed however somewhat, as to the order of their relative intensities, from those observed with nitrogen alone. One of the lines appeared to coincide with the chief coronal line 1474K, although it was not so sharp as it appears in the solar spectrum. An oxygen line, likewise observed, has the position 1462 K very nearly, and closely agrees in point of refrangibility with a bright coronal line noticed by Denza and Lorenzoni during the eclipse of the 22nd Dec., 1870. A second oxygen line, less bright but sharp and distinct, has the position 18359-++-1K. The author directs attention to the complete change which the spectrum of an air-tube undergoes by the intro- duction of hydrogen. According to the method by which Wright calculates the amount of gas present in an iron (see the meteorite ‘of the Red River, Texas, page 564), this metal occludes 4:69 times its volume of mixed gases. Although the greater part of the gas had been removed, the author is of opinion that the whole amount was by no means exhausted. The fact of the volume of gas in this instance being in excess of that obtained by Graham and Mallet probably arises from the Tazewell iron having been in a finely divided state, and his latest researches on the iron enclosed in the meteorite of Iowa (1875, February 12th) support this assumption. (To be continued in our next Number.) IV.—Nore on Mr. R. Matter on THE PrRIsmMATICO STRUCTURE oF BASALT. By G. Povzrrr-Scrorz, F.R.S., F.G.S., ete. \ R. R. MALLET’S paper on this subject, of which an abstract ap- pears in the Proceedings of the Royal Society, as read January 21, 1875, lays claim to a certain amount of originality in the views propounded by him, to which, as well as to the correctness of some portion of them, exception must be taken; though it may be that the conciseness of an abstract will to some extent account for what appears imperfect in its reasoning. For this reason no attempt will be made here to review in detail the general theory announced by Mr. Mallet 1 A.W. Wright. Amer. Jour. Sc., 1875, ix. 294. 2 J. L. Smith. Amer. Jour. Se., [2], xix. 153, G. Poulett Scrope—Note on Mr. R. Mallet. 413 on the cause of the occasional singularly perfect columnar configur- ation of basalt and other volcanic rocks. It may suffice to say that, so far as the present writer can understand it, as given in an abridged form, it differs in no particular from that which was furnished by himself fifty years back, in the first edition of his work on Volcanos (ed. 1825, p. 185), and subsequently repeated in the second edition of 1862 (p. 96). On one minor portion of this paper I am however desirous of offering a comment at present, because it involves a mis-statement of fact of some little importance towards the formation of just ideas on the problem in question,—a mis-statement which is quite astound- ing when it would have been easy for Mr. Mallet to ascertain the truth, and so avoid the error into which he has fallen. It has refer- ence to a portion of Mr. Mallet’s theory on which he appears most specially to pride himself as wholly original, viz. that of the formation of those curious cup-shaped or ball-and-socket cross joints, sometimes, but very rarely, found in basaltic columns.! “This solution,” he says, ‘‘is believed to be the first ever presented, which completely accounts for the production of the very remarkable cup-shaped joints.” (p. 182, line 22.) Mr. Mallet’s “ original” solution of the problem is not very clear ; but this is of the less consequence, inasmuch as it is founded on an assumption, or rather assertion, which is untrue, viz. that the con-_ vexities of the joints always point in the same direction, away from the surface at which the cooling commenced. In this he is wholly mistaken. It is the fact that the protuberances are found to occur indifferently in both directions side by side in the same mass of columns; and of this fact Mr. Mallet might have convinced himself any day by simply examining the group of basaltic columns from the Giant’s Causeway, which, as a member of the Geological Society, he must have frequently passed in their rooms. This group consists of three columns, figured in Mr. Woodward’s paper, page 346, Vol. VIII. of the GrotocicaL Magazine. Now it is perfectly evident that in all of these three columns the direction away from the cooling sur- face at which the splitting commenced must have been the same, and yet in the very upper layer of this specimen the top surfaces of the three columns are alternately convex and concave. Still further, upon removing the first articulation of the left-hand column, it is found to be biconcave, in the fashion of a double-concave lens,—the corre- sponding convexities pointing of course both ways. So much for 1 [tis remarkable how rare these cup-and-ball-shaped joints in basaltic columns are. They occur, as is well known, in the Giant’s Causeway,.and at Staffa; though it is by no means common in Scotland or Ireland. It is found in some of the basaltic currents of Central France; see the descriptions and engravings in Abbé Le Coq’s admirable work on that district, vol. v. But im Germany, notwithstanding the number and perfect regularity of many ranges of columnar basalt to be seen there, such joints appear to be wholly absent; since I am informed by my friend, Mr. J. W. Judd, at present on a geological tour in that country, that a single joint of the kind from the Giant’s Causeway in the Museum at Dresden is the only example known among the German geologists he has met with, and is looked upon as an extraordinary phenomenon. 414 Notices of Memoirs—Francesco Castracane Mr. Mallet’s positive assertion that the “convex surface of a fracture (i.e. joint) always points in the same direction as that in which the cooling proceeded.” That this mis-statement of the fact is not a casual error is shown by further passages, in which (page 183) it is asserted that if the cooling commences from the top surface of the bed, the “convex surfaces of the cross joints all point downwards ;”’ whereas if the mass cooled from the bottom, the “convex surfaces of the joints of the lower prisms point upwards.’ Mr. Mallet’s theory, therefore, rests, unfortunately for him, upon a false assumption, which he might easily have ascertained for himself without stirring from London. Mr. Mallet, however, may perhaps reply that his theory is correct, whether the assumption on which it rests be true or not, since I observe from an article in the latest number of the Proceedings of the Royal Society (162, vol. xxiii. page 444), that he still adheres to his preposterous notion of a Geyser underlying the volcanic vent of Stromboli,—even though it has been demonstrated to him that the steam and water tube required on this supposition must be at least 2000 feet in depth! He takes no notice, moreover, of the many arguments employed by me in the paper to which he refers,! against his theory, besides the height of the crater-floor ? above the sea-level —any one of which is alone sufficiently conclusive as to its unten- ability. NOTICES OF MEMOTRS. pcere Aa Sea DIATOMACEH IN THE CARBONIFEROUS PrERIOD.? By Signor, Count, Abbot, Francesco CasTRACANE. (Translated by Miss L. H. Lirrtepaz, Dublin.) O great is the importance of Coal, which constitutes the chief wealth of some favoured countries, and is the principal lever of England’s power, that no one will wonder that its nature, its mineralogical properties, and the history of its formation, have claimed the attention of scientific men. This valuable substance, in which Nature has preserved to the feverish activity of our century the principal aliment of the metallurgic industry, of arts and com- merce, has been the subject of the learned researches of many highly distinguished naturalists and geologists. They have examined the impressions of the many vegetable and animal remains which 1 Grou. Mac. Dec. 1874. 2 Bye-the-bye, why will Mr. Mallet persist in calling the bottom of the crater its “ fundus’ ? fondo is, no doubt, the word in use for it among Italian writers. But our own language possesses more than one synonym for the thing intended, any one of which would better express the idea to English ears. So, too, in the article on columnar basalt, the French word “ couche’’ is always used by Mr. Mallet in lieu of our native synonyms of ‘layer,’ “‘ zone,’’ or “ film,”’ all equally expressive of his idea. Other writers, likewise, on volcanic subjects, still continue following the bad example set by Dr. Daubeny, in speaking of a ‘“‘ coulée”’ of lava, when they mean a ‘stream ’”’ or ‘‘ current,’ words equally expressive of a once fluid or flowing mass. _ 3 “Te Diatomace nella Eta del Carbone.” Extracted from the Atti dell’ Accademia Pontificia de’ Nuoyi Lincei,” Rome, 27th year, 3rd session, February 22, 1874. On Carboniferous Diatomacee. 415 it contains, and have determined their genera and species; while, by cutting very thin slices of the coal itself, they have been enabled to study, with the aid of the microscope, its texture and minutest ingredients. These researches did not, however, reveal the presence of some tiny little Diatoms which chanced to be there; thus it has been affirmed that Diatoms were not contemporaneous with coal; a distinguished German naturalist and micrographer having absolutely denied it to the author last summer, placing rather the first appearance of Diatoms at an infinitely more recent period. The only mention which came under my notice of the existence of Diatoms in coal was a quotation from Acadian Geology by the distinguished American naturalist, Dr. Dawson, referred to by Professor Huxley in a lecture given by him On the Formation of Coal. To prove the assertion that coal is not a subaqueous, but simply a sub-aerial formation, Dawson, amongst other arguments, says that ‘with the exception perhaps of some Pinnularie and Asterophyllites, there is a remark- able absence from the Coal-measures of any form of properly | so-called aquatic vegetation.” On reading that quotation my curiosity was aroused in the highest degree; because, whilst ardently pursuing the study of Diatomacez, a strong conviction of their remote antiquity had fixed itself in my mind. My wishes upon this subject were not influenced by any vain sentiment, but I felt the importance of such an argument in es- tablishing a principle set forth by me on several occasions. Having discovered that in salt, fresh, and brackish waters the Diatomacess (together with sea-weeds and vegetables of a higher order) de- compose the carbonic acid under the action of the sun’s rays, and, assimilating the carbon, set free the oxygen which is the chief and indispensable element in animal respiration; and having experi- mentally found out that Diatoms, far from sustaining injury from the presence of animal substances in a state of decomposition, rather derive benefit from them—restoring, in short, the water itself to its original state of purity; I deduced from this the inference that in nature the first appearance of Diatomaceze must have coincided with, if not preceded, the first moments of the existence of the primitive animal inhabitants of the water. The last time I expressed this opinion I added that sooner or later some rocks of Paleozoic age would, without fail, be met with to furnish indubitable proof of the presence of Diatomaceze contemporaneous with the first animals that lived in the waters. But I was very far from thinking that only a few days after I had uttered this prognostic it would be actually verified. In a small residue collected from the incineration of a fragment of coal (given me as coming from Liverpool), carefully handled and placed for microscopic inspection, my satisfaction may easily be imagined when several Diatoms, perfectly distinguish- able, presented themselves in the field of the microscope. In this way I was enabled to prove with all certainty what I had premised, viz. that Diatoms vegetated in the Carboniferous period, that is to say, with the earlier forms of animal life in the Paleozoic ages. 416 Notices of Memoirs—Francesco Castracane In spite, however, of this successful result, obtained by the most scru- pulous attention and caution, to avoid the smallest possibility of mistake, I confess that (from perhaps excessive timidity) I hesitated to submit it to public opinion. I therefore resolved to await the result ofa contra-proof which I should be able to have by trying again a small remaining piece of the same coal, not omitting to employ on each occasion a perfectly clean test-tube that had never been used before. Ineed not say what was my gratification at seeing some Diatoms again in the field of the microscope; thus confirming the correctness of my previous experiment. And as a final argument I will add that the forms I recognized and ascertained in the second experiment were either more or less identical with those of the first, so that there could not remain the least doubt of the presence of the Diatoms in that coal. Hence it stood proved upon evidence that they must have existed contemporaneously with the plants, the remains of which serve as fuel in furnaces, and give life and motion to the countless steam-engines which make distances vanish and promote commerce. The Diatoms that I met with in this coal chiefly belong to fresh- water genera and species, if we except perhaps a Grammatophora, a little Ooscinodiscus, and perhaps an Amphipleura, which appeared to me to be the 4. Danica. Amongst fresh-water Diatoms I have distinguished the following :— Fragilaria Harrisonii, Sm. =Dontidium Harrisonit. Ephithemia gibba, Ehrbg., Prz. Sphenella glacialis, Prz. Gomphonema capitatum, Ehrbg. Nitzschia curvula, Prz. Cymbella scortica, Sm. Synedra vitrea, Prz. Diatoma vulgare, Bory. The influence of the sea, which is shown in the different shapes of salt-water Diatoms (although only single specimens presented them- selves among the many fresh-water ones in the residue of the Liverpool coal), offers us an indubitable proof that the waters of the sea must have penetrated amidst the remains of that ancient vegetation. To account for the presence of those few little marine forms among fresh-water Diatoms, I do not think we can admit the hypothesis that they were merely adventitious, as if carried thither by the wind. Although there can be no reluctance to acknowledge that such a transportation could take place, yet I do not find it possible to persuade myself that some valves of marine Diatoms which have been now and then detected in the atmospheric dust, may be precisely en- countered amongst a small number of fresh-water Diatoms. It is to be added, moreover, that I do not remember ever having met with a notice of marine Diatoms being found in the atmospheric dust, whereas fresh-water forms are often spoken of. : It is truly an easy thing to understand how at the drying up of a ond the wind may sweep away from the surface the minute siliceous skeletons of Diatoms which have been growing there for generations ; but one could not so readily understand how the same could happen to those of the sea. However, the fact that at the very remote period On Carboniferous Diatomacee. 417 of the coal formation Diatoms lived and formed a part of its flora, offers us, it appears to me, a most valuable opportunity of making an observation of much greater import. However little any one may be accustomed to the contemplation of nature, it is easy to recognize how the various organic types can to a certain extent be modified by the influence of climate and other circumstances under which they are living. Nevertheless, the effect of such influences is so much less perceptible, and the consequent modification so much slighter in proportion as the type occupies a more elevated position in the organic scale. Now, although, when disserting last year upon the structure of the Diatoms, and the various parts and substances which compose them, as well as the marvellous ornamentation to be admired in their valves, I allowed myself to be carried away by enthusiasm for these wondrous organisms, so far as to say’ that “the Diatoms, far from being such humble little plants as to deserve banishment among the lowest organizations of the Vegetable Kingdom, have a far better right to be looked upon as forms as noble in their structure and perfect arrangement as they are marvellous for their minuteness,” it is nevertheless true that, organically considered, they must be acknowledged simpler than and therefore inferior to the humblest mosses and vascular plants. Nevertheless, who could have expected (on the supposition that Diatoms have been growing from the time of the first dawn of life upon the earth, in such enormously long evolutions of centuries, and in the succession of ever new states of temperature and climate) that they would not at least have been greatly changed? All the forms I have been able to observe amongst the few ashes of the before- mentioned coal present such an appearance that the most practised and sharpest eye could not detect the slightest difference between them and actually living Diatoms. In outline, structure, shape and number of the flutings,—in short, in all the peculiarities which characterize the species that we meet with in a state of actual vegetation,—the Diatoms of the Carboniferous and Paleozoic periods agree exactly. In such immeasurable succession of centuries, organic life under this most simple and primitive form since its appearance upon the globe (notwithstanding the tremendous catastrophes which have altered the condition of its surface) has not experienced the slightest change, and remains unaltered up to our day: so true is it that upon each organic type Nature has im- posed an immutable law which restrains it within its own limits. But the successful result I obtained from the examination of the Liverpool coal, and the discovery of Diatoms contemporary with its formation (thus conclusively proving the existence of Diatoms in the Paleozoic epoch), revived my desire to institute a similar research through coal from other sources. Otherwise it might be questioned by some whether the Diatoms found in the chip of Liverpool coal had not simply adhered to it by accident, without being contem- porary with its formation: as it might happen that Diatoms should 1 See my note ‘On the Structure of Diatoms,’’ Atti dell’ Accad. Pont. dei Lincei, Anno 26, 19 Gennaro, 1873. DECADE II.—YOL. II,—N0O. IX. 27 418 Notices of Memoirs—Castracane on Diatomacee accidentally be discovered upon the surface of granite, or any other older rock, without any one assuming that they grew in the period of the granite’s formation. Such objections did actually occur to my mind ; they lost all force, however, by the reflection that the scrap of coal upon which my examination had been made came out of the solid mass of that mineral, and not from off the surface; besides, the piece from which it was detached is preserved in the Mineralogical Cabinet of the “‘Sapienza’”’ in Rome, and thus the discovery made by me may be controverted by other people at any time. These examinations are rendered easy to me from the special arrangement of my microscope, which is such that it enables me to be sure of having examined in turn each point of the entire substance, giving me, besides, leisure to mark the position of the smallest form whatsoever, in order to be able to find it again at any moment. After having fully determined the fact of the presence of Diatoms in the Liverpool coal, I resolved to ascertain whether the same could be detected in coal from other sources. With this intention I have up to the present time made analogous investigations upon three other samples obtained from the before-mentioned Mineralogical Cabinet. One is from the mines of St.-Etienne, another came from Newcastle, and the third was a fragment of the so-called ‘“cannel- coal” of Scotland. Notasingle one of these different substances failed to reveal Diatoms in greater or less numbers. Of these I did not remark any that were not fresh-water; nevertheless the Species varied in each. The forms I found did not give me occasion to note any novelty whatsoever, while there was not one among them of which I would have hesitated in declaring that it was a living form. Thus the presence of Diatoms (which seemed to me such a great fact to have been able to prove in the Liverpool coal) showed ‘itself persistently in the three other different kinds, so that I begin to suspect that perhaps Diatoms accompany every stratum of coal. From the presence of Diatoms in coals not only does the principle established by me of the necessity of Diatoms in water to maintain animal life stand confirmed, but we have a new subject of study in © recognizing the highly important part which Diatoms and. mnioroseople life have ever played upon the earth. From all this arises the necessity of the geologist directing the greatest attention to whatever traces remain to us of these minute beings which had so much share in the history of the globe. I am encouraged to hope that these observations of mine, or at least the fact proved by me of the presence of Diatoms in coal, will not be regarded as undeserving attention by some geologist or micrographer. It will be most gratifying to me if my remarks and experiments, under the direction of some more competent person, prove any advantage to science. In that case, in order to facilitate the task still more to any one less expert who may wish to under- take such an examination, I shall add a hint as to the process followed by me in conducting these researches. The course to pursue is decided by the flinty nature of the Diatom-valves, and in order Reviews—Prof. Duncan's Indian Geology. 419 to separate them from the mixture of calcareous or organic matter with which they are found united, it is usual to put the whole into a glass test-tube with hydrochloric acid, adding caustic potash from time to time, keeping all slowly dissolving by heat, in order to isolate the silex, destroying the remainder. But in unburnt coal it is too difficult to dislodge the carbon, and the acids have little effect upon it. I must, however, refer to the calcination I effected by grinding up the substance, and then, collecting it in a china vessel, placed upon a stove in a glass tube, subjecting the whole to the action of the heat, while, at the same time, a slight current of oxygen crossing the tube combined with the carbon in creating carbonic acid. Experience has taught me, however, the necessity of conducting this operation at a lower temperature, in order to prevent the alkaline or earthy bases and metallic oxides, which may be amongst the ashes, from forming vitreous silicates by melting and mixing with the valves of the Diatomacez. It is also well to leave the glass tube, in which the fusing is going on, uncovered, in order to watch its progress. The small residue obtained through this process is to be put into a clean test-tube, adding nitric acid and hydrochloric acid, and caustic potash, assisted by the heat of a lamp to eliminate any alkaline or earthy base, and every trace of metallic oxides. The last operation over it only remains to wash repeatedly with distilled water the very light dust which is left behind, letting it stand for some hours each time to settle, in order to be sure of not losing the smallest particle of it in pouring off the water. Those who follow this method exactly cannot fail to succeed. The object may then be mounted with Canada Balsam, or in any other suitable medium: and steadily and closely watching it under the microscope, they will not be long before they see some valves of Diatoms, entire or broken. If any investigator wish for fuller information, I shall have great pleasure in gratifying him, and will consider myself honoured by his applying to me. Ho) OST OV IE ET WG TS) Rb DPE I.—An Axsrract oF THE GroLocy or InpIa. By Pror. P. M Dunoan, F.R.S. (London, 1875.) HIS Abstract is a useful addition to geological literature. With- out any pretension to a general treatise on the subject, and consisting merely of geological facts, with no sections or illustrations, it is intended as a text-book for the students of the Indian Civil En- gineering College, where Geology is fortunately recognized as a necessary part of their education, and as an advantage to their future career. The late Mr. Greenough had collected a vast amount of ma- terial, which he used in preparing his large geological map of India in 1854, a reduced copy of which, with notes, appeared in ‘ Petermann’s Geogr. Mittheilungen’ for 1855. But this knowledge has been considerably increased by the subsequent labours of Carter, Drew, 420 Reviews—Prof. Duncan's Indian Geology. Strachey, Falconer and Cautley, D’Archiac and Haime, as well as by the valuable Memoirs and Reports of the Geological Survey under the direction of Dr. Oldham, the result of the arduous and exhausting labours of himself and colleagues in the field-work of the Indian Survey. In this Abstract the geology of India is considered under two heads,—the Himalayan and Peninsular types; the former com- prising the Himalaya, the Salt-range, the hills on the west of the Indus to the sea, and the great alluvial districts through which the Indus and Ganges with their tributaries flow; the references to this district are nearly restricted to the details of the Himalayan and Indo-Gangetic area. The Peninsular province is bounded on the north-west and north-east by the alluvial plains, and elsewhere by the sea. The successive geological formations, when they occur, are treated of in descending order in the above two provinces, and thus their differences and resemblances may be compared ; but the same formations are not invariably present in both geological provinces, and it appears that the remains of former land surfaces are much more common in the Peninsula than in the Himalayas, where the marine deposits preponderate. There are many interesting and peculiar points of Indian geology concisely described, as to their occurrence and origin, such as the “ Rigar, or cotton soil,” the Kunkur and Laterite. The Sub-Hima- layan rocks are noticed, and also their rich mammalian fauna, so ably described by the late Dr. Falconer and Major Cautley, who obtained the bones from the Sivalik strata occupying many thousand feet in thickness, and also from the Nahum series, both of Miocene age, and which include remains of Primates, Carnivora, Proboscidea, Rumin- antia. ‘The Monkeys are all old-world types, and in all probability there is no satisfactory specific distinction between the forms and the recent species of Asia. The Loxodons are allied to the African elephant. Hippopotamus, no longer Indian, is an African form, and the Cameleopards are African in their present distribution. The Sivalik fauna had therefore Asiatic and African members; and whilst the majority of its species are extinct, many exist at the present day in India. In the Peninsular province the Malwa and Deccan traps occur; they are post-Cretaceous, of great thickness, and form a very important feature in the geology of India, for they extend over 200,000 square miles of Western and Central India, and formerly covered a much larger surface, as they have suffered from denudation. In this province also is the Damuda Coal-bearing series, which, with the sub-divisions and plants, are fully noticed at pp. 44-48; and a detailed account is given of the five zones of rocks of which the Himalayas appear to be formed, as derived from the sections given by Medlicott and Stoliczka. Most of the chief European strata appear to be more or less fully represented by equivalent formations, with the exception of the Cambrian, Devonian, Carboniferous Coal Lower Oolite, and Neoco- mian. The oldest agile ears rock is referred to, the Bhabeh series or Lower Silurian, which may be newer than an important formation called the Vindhyan, of unknown age, and which occupies a very & Reviews—Contejean’s Elements of Geology, etc. 421 large area in the North-west and Central provinces, and probably occurs in the neighbourhood of Madras. From this series the finest building and ornamental stones of India are obtained, chiefly in the upper or Bundair group; but the lower or Kymore sandstones are also extensively worked, especially at Chunar. __ Although intended merely as notes of reference for the student of Indian geology, the general geological reader will find it of some interest as comprising our present knowledge of Indian geology, and in comparing it with that of the European area, for which purpose a table of the presumed equivalent formations is given, which, although showing a general similar succession of formations, may not represent the synchronism with European strata, “‘for it must be understood that the term equivalent does not infer synchronism or contempo- raneity. It appears that some forms of life existed earlier in India than in the European area, and this, taken with the fact of the occur- rence of the same species in the distant strata, requires the inference that time elapsed during a migration or a natural distribution.” This Abstract is alike creditable to Prof. Duncan and to the author- ities under whose auspices it has been published. J. M. I].—ELimuents Dr GEOLOGIE ET DE PaLfontotocis. By Cu. ContTE- JEAN. Paris, 1874. 8vo. pp. 745 (467 Woodcuts). T is by means of the higher class of text-books to which this work belongs that we are kept posted up in the progress in ~ other countries of Geology as a whole. It is seldom, however, that a manual presents so many points of contrast with its forerunners, nor, it may be added, so many signs of advance, as Prof. Contejean’s Eléments. French Geologists, though frequently of the deepest red in politics, have always been extreme Conservatives in their special science. They have in many cases shown a degree of deference to mere authority in scientific matters which we can scarcely match in the annals of British Geology. In no instance has this deference been more marked than in the all but universal acceptance of the late M. Elie de Beaumont’s ‘“‘ Pentagonal System.” ‘To this theory we owe the collection of so large an accumulation of valuable stratigraphical facts, that it seems almost ungrateful to say that it is refreshing to see in Prof. Contejean’s book not only a very fair résumé of the famous system, but also a very full and complete refutation of it, comprised altogether in some twenty pages of close print. We, in England, who have never been caught in the great Pentagonal net-work, are hardly able to appreciate the importance of so clear and able a statement of the insuperable objections to it, coming, as this does, from a man holding an acknowledged position in the professorial hierarchy of France. Truth will out, as we all know, but due honour should be given to those who help the most vigorously to draw her out of her well. This Prof. Contejean is distinctly doing by means of his new manual.! 1 It may be well to mention that Prof. Contejean’s book was published just before M. Elie de Beaumont’s lamented death. & 422 Reports and Proceedings— Five-sevenths of his book deal with Physical Geology, the historical portion being very briefly, and it may be somewhat inadequately, treated, although it is illustrated by some 350 capital cuts. It is only fair to the author to say that he looks upon Paleontology, on principle, as an auxiliary seience only, and not, as too many writers of text-books would appear to do, as the main end and object of Geology. In the account of the various great geological stages, the author scarcely does justice to his advanced views when he retains, even apologetically, so misleading a term as ‘ Epoque de transition.’ In including the Coal-measures in the Terrain Carbonifére, on the other hand, good service is done, since the custom of limiting the application of this term to the Carboniferous Limestone Division is one much on the increase among French geologists, and one fruitful of misunder- standing. Restorations of fossil vertebrates are confessedly to a certain extent hypothetical, but even with this reservation it is difficult to believe that the Megalonyx was really quite such an extraordinary beast in the flesh as he is represented in fig. 464, or that the body of the Pterodactyl was clad in particoloured scales like a serpent! ! fig. 347 —almost the only two illustrations in the book to which exception can be taken, the rest being, when new (as many of them are), of a high order of excellence, and when otherwise, chosen from the best among old friends. : That the physical division of his work is up to the present state of knowledge wiil be seen when it is said that Dr. Carpenter’s latest dredgings, that Mr. Croll’s “ Excentricity ” results, and that the current theories of both are utilized by M. Contejean. Indeed, the list of authors quoted which precedes the copious Index is a sufficient proof that the oft-repeated, and not altogether undeserved, accusation that French men of science are apt to ignore foreign work, does not apply in any degree to the author of this manual of Geology. (Cis Ale JD eae @ ea SS AUN) 2 @ Gian SNe Se ——_o—_—_ - GrotocicaL Society or Lonpon.—June 9th, 1875.—John Evans, Hsq., V.P.R.S., President, in the Chair.—The following communica- tions were read :— 1. “On Prorastomus sirenotdes, Owen. (Part II.).” By Prof. Owen, C.B., F.R.S., F.G.S. The author has submitted the skull of a Sirenian from Jamaica, described by him in 1855 under the name of Prorastomus sirenoides, to a careful re-examination ; and in this paper notices the characters revealed by further removal of the matrix, and discusses the bearings of the facts thus ascertained upon the relations of the animal and of the Sirenia generally. The parts which have been brought to light are the base and roof of the cranium, the zygomatic arches, the hind half of the mandible, with the articular part of the condyle, and the greater part of the atlas. The characters presented by these parts Geological Society of London. 423 are described in detail, and the characters of the genus are compared with those presented by other genera of Sirenians, both living and fossil, especially Manatus and Felsinotherium. The dental formula of Prorastomus is given as :— » 35 1—1 = =8 i. = Gs O01. jeqyaps = m. ee = 48; thus, as in Manatus, showing an excess in the molar series over the type of the terrestrial herbivorous mammalia, whilst the incisors and canines retain the common type as to number and kind, and have not been subjected to so great a degree of suppression or of indivi- dual excess of development as in existing Sirenians. The presence of these small subequal incisors in both jaws of Prorastomus is the most marked feature in which Prorastomus adheres to the normal mammalian type, while showing the essential characters of the marine Herbivores ; but a similar tendency is shown in other parts of the skull. The author regards the Sirenia as essentially monophyodont. Halicore and Felsinotherium depart further from the type than Halitherium and Manatus, and these than Prorastomus. Rhytina, with a better developed brain, and with the jaws edentulous when adult, is an extreme modification of the Sirenian type. The rudi- mentary femur in Halitherium is to be regarded as the result of degeneration through lack of. use, from better-limbed prototypal mammals. With respect to the genealogy of the Sirenia, the author remarks that Hickel derives the Sirenia, Zeuglodontes, and Cetacea, toge- ther with the Artiodactyla, from the branch Ungulata, and the Perissodactyla from the branch Pycnoderma of the Mammalian trunk ; but that while Halitherium and Felsinotherium show the molar pattern of Hippopotamus, Prorastomus exhibits that of Lophiodon and Tapirus, to which Wanatus also adheres, rather than to any Artiodactyle type. The author suggests that both Ungu- lates and Sirenians diverged at some remote period from a more generalized (Cretaceous?) mammalian gyrencephalous type; and that the marine Herbivora in the course of long Eocene and Miocene eons were subjected to conditions producing modifica- tions of their molars, leading on one side to an Artiodactyle and on the other to a Perissodactyle character. As Prorastomus by its more generalized dentition and shape of brain represents a step nearer the speculative starting-point than any other Sirenian, it acquires a great interest, and the determination of the precise age of the (supposed Hocene) bed from which its remains were derived is very much to be desired. 2. “On the Structure of the Skull of Rhizodus.” By L. C. Miall, Esq., F.G.S. In this paper the author described a large skull of Rhizodus from the coal-shale of Gilmerton, near Edinburgh. The characters de- scribed show that Rhizodus is a Ganoid fish, and that its position in the order is not far from Holoptychius and Megalichthys. The author referred it to the cycloidal division of the family Glyptodipterini. 424 Reports and Proceedings. 3. “ Appendix to a ‘Note on a Modified Form of Dinosaurian Ilium, hitherto reputed Scapula.’” By J. W. Hulke, Esq., F.R.S., F.G.S. This paper contained a notice of the pubis of Iguanodon, which proves to be identical with the smaller of the two specimens figured by the author in a former paper (Quart. Journ. Geol. Soc. vol. xxx. pl. xxxii. fig. 1). When inverted, its long slender process is easily identified with that of the pubis of the nearly allied Hypsilophodon, and this slanted downwards and backwards parallel to the ischium, the little process of its posterior surface meeting a corresponding process of the ischium, and converting the upper end of a long narrow obturator space into a foramen. The pubis of Iguanodon contributed largely to the formation of the acetabulum, thus re- sembling that of existing Lacertilia, as also in its possession of a broad ventral extension, probably united with that of the opposite side by a median symphysis. The specimens described in this paper were collected in the Isle of Wight by the Rev. W. Fox. 4. “Notes on the Paleozoic Hchini.” By Walter Keeping, Esq., of the Woodwardian Museum, Cambridge. Communicated by Prof. T. M‘Kenny Hughes, F.G.S. The author alluded to the interest excited by the discovery of Kchinoderms with flexible tests; and having pointed out the differ- ence between the more modern and the Paleozoic forms (their plates imbricating in opposite directions), gave a description of the follow- ing forms :—I. Perischodomus. Il. Rhechinus, g. n., sp. R. irregularis (Keeping). III. Palechinus (?) intermedius (Keeping). IV. Pale- chinus gigas (M‘Coy). V. Palechinus sphericus (M‘Coy). VI. Ar- cheocidaris Urii (Fleming). In conclusion, the author proposed a new method of classification for the Hchinoidea. He also noticed the existence in the Museum of the Royal School of Mines of a British fossil which appears to belong to the group of Hchinoidea with numerous ranges of ambulacral plates, represented in America by the genera Welonites, Oligoporus, and Lepidesthes. 5. “On some Fossil Alcyonaria from the Australian Tertiary Deposits.” By Prof. P. Martin Duncan, F.R.S., V.P.G.S. In a former communication in 1870 the author described some fossil corals from the Tertiary strata near Cape Otway, in the pro- vince of Victoria. In one, which he called the ‘“ Upper Coralline bed,” the equivalent of the Polyzoan limestone of Woods, he found specimens which he did not then describe, as they were not true corals. Belonging to the Isidinez, and not being of great interest, he retained them until the receipt of some similar specimens from New Zealand, described in the following paper. The Australian forms described by the author were shown to be nearly allied to the recent Isis hippuris and the fossil I. corallina. 6. “On some Fossil Alcyonaria from the Tertiary Deposits of New Zealand.” By Prof. P. Martin Duncan, F.R.S., V.P.G.S. The New Zealand fossils referred to in the preceding paper were sent to the author by Capt. F. W. Hutton, F.G.S.; they were de- rived from the Awawoa Railway cutting, and were from the upper Correspondence—Mr. G. H. Kinahan. 425 part of the Oawaru formation. They consisted of fragments of species of the genus Is’s and of Corallium. These were compared with those from the Australian Tertiaries, and the author inferred that both deposits were formed under similar conditions, and that they were.at least homotaxial, whatever their precise geological age might be. 7. “On some Fossil Corals from the Tasmanian Tertiary De- posits.” By Prof. P. Martin Duncan, F.R.S., V.P.G.S. The author described a new species of Dendrophyllia possessing very unusual characters, the epitheca replacing the true wall, and giving the specimen a marked Paleozoic appearance. The fossil was obtained from a Tertiary deposit, and was associated with Placo- trochus deltoideus, a well-marked coral, characteristic of a definite geological horizon in Victoria, namely the lower beds of the Cape Otway section, belonging to the Lower Cainozoic period. For this coral he proposed the name of Dendrophyllia epithecata. A much worn reef-coral was found associated with the above. CORRESPONDENCE. ON THE NOMENCLATURE OF ROCKS. Str,—In “ A Handy-book of Rock Names” it was suggested that some of the rocks therein included as granitoid varieties of Liparite “ought probably to be classed among the granitic rocks.”! This opinion seems also to be shared by Mr. J. W. Judd, F.G.S., as in his lately published description of the Ponza Islands,’ he particularly mentions the granitoid rocks of that island and certain others in the Huganean Hills, Hungary, etc., which he considers to be of the same class as the North American rocks, for which Richthofen’ has suggested the name Nevadite, or granitic-rhyolite. If we accept this name, we add to our granites : Nevapite (Richthofen), a granitic rock, having a more or less crystalline felsitic matrix, inclosing crystals of quartz, one or two felspars (orthoclase and albite or oligoclase), mica or amphibole. This granitic rock represents the passage rock between trachyte and normal granite ; similarly, as a siliceous elvanite, among the older rocks, is the passage rock between felstone and normal granite. There has, however, still to be discovered and described, the passage rocks between augite and granite ; and such rocks I suspect to exist in the neighbourhood of Carlingford Lough, Ireland (parts of Cos. Armagh, Down, and Louth). Jn this area my colleague, W. A. Traill, has found either four or five distinct intrusive granites: first, Newry granite of pre-Carboniferous age; second, Mourne granite of post- Carboniferous age; third, elvanite, probably of the same age as the Mourne granite; and fourth and fifth, granitic rocks, possibly of Ter- tiary age. The latter rocks seem principally to occur in the Carling- ford district on the south of the Lough, and are variable in character ; some being similar in aspect to some of the typical elvanites ; while 1 A Handy-book of Rock Names, p. 71. London, Robert Hardwicke, 1873. 2 Grou, Maa. July, 1875, p. 298, et seq. 426 Correspondence—kev. T. G. Bonney. others are more or less coarsely crystalline rocks, in which pyroxenic minerals usually predominate. These rocks are protruded in larger or smaller masses, and allied to them are dykes of a maculated basic rock, ove of the hybrid rocks of Durocher. ‘These dyke rocks are very undecided in composition, and in places may be classed as dolerite, while in others they must be called either Felstone or Trachyte. These maculated rocks seem to graduate into Dolerite and Augite, similar to and probably of the same age as the Tertiary dolerites of the Co. Antrim. A typical elvanoid rock belonging to one of these groups (fourth or fifth) occurs at Goragh Wood (where it is extensively worked), coming up as a mass through the older Newry granite. This rock would answer the description for Nevadite, and possibly may be one of the granitic rocks belonging to the trachytes of Antrim. The rocks in the country about Carlingford Lough at present are only partially known ; this, however, ought not to be for long, as they have been carefully examined by Mr. Traill. In conclusion, I may mention that in the Mourne district to the north of the Lough, Mr. Traill found some of the dykes similar to and probably of the same age as the maculated dykes of the Carlingford district, that at their margins suddenly changed into a vitrioid rock, locally called Bottleite, that when examined by our colleague, F. Rutley, F.G.S., was pronounced to be Trachalite. This trachalite in places assumes a fibrous structure, apparently somewhat similar to that described in the obsidian of Ponza by Judd, and from fibrous it seems in places to pass into a minute columnar structure, the rock at the same time changing into anamesite or basalt. Judd seems to be of opinion that this fibrous structure is due to extreme pressure ; with this I cannot agree, as it may occur in places where the dykes evidently occur filling shrinkage fissures. Many, indeed most, fibrous varieties of minerals and rocks, seem to be due to crystalline structure, the substance being deposited from solution ; this, however, is not always the case, as in some instances the process seems to have been somewhat similar to drawing out heated glass into hairs. Such, however, could scarcely be due to pressure, and in many places where observed it looks as if the foundations of the dyke had given way, and that films between the consolidated portion of the dykes, or one of its walls, had been drawn out while the dyke was sinking. WEXFORD. G. H. Kiyanan. GLACIAL EROSION. Sir,—There are some points in Mr. Goodchild’s interesting com- munications on Glacial Erosion (Grou. Mac. pp. 3238, 856), concerning which I should like to make a few remarks. As I have not the advantage of much knowledge of the principal district which he describes, I cannot attempt to discuss them in detail, but as most points in his description appear to me to be common to all similar districts that I have seen, I venture to offer two or three general criticisms. He objects (p. 828) to the theory which attributes the formation of rock ledges mainly to fluviatile action, because of (1) their height Correspondence—Rev. T. G. Bonney. 427 above the present level of the existing streams; (2) the general paral- lelism of the scars on opposite sides of the valleys; (8) the persist- ence of the peculiarities in form due to the nature of the bed. But with regard to these objections, I may remark that, so far as my memory serves me, they would hold-in every hilly district that I have seen, where bedded rocks of a similar character exist, whether the district has been exposed to glacial action or not; also that it is no uncommon thing to see a river valley, with nearly flat bed, far wider than the existing stream. In some cases these may be explained by the volume of the stream being formerly greater, as it no doubt was occasionally in past history ; in others the slow motion of the river from one side of the valley to the other would suffice. Further, that if a configuration were once given to the banks of the valley, and these were afterwards cut back in tolerably homogeneous reck by aerial denudation only, the original form would still be gen- erally preserved, because the recession would be approximately uniform throughout. These phenomena are to be seen in the valleys of the Alps and the Jura, and if he is prepared to attribute these mainly to glacial erosion, he must get over some objections to which I will presently refer. Is it necessary that swallow-holes should be formed by streams ? Of course streams may form them—witness Gaping Gill; but I have seen districts riddled by swallow-holes, as the “ Stony Seas ”’ of the Eastern Alps, which were evidently formed by the rain drainage of a very small area. Some of those also in the Chalk have, I think, been simply dissolved out by the subterranean drainage of a very limited basin.: The formation of a swallow-hole, I think, mainly depends on the nature of the rock. I have, however, seen in the Alps swallow-holes which have been modified by the erosive action of the streamlet. F The large amount of debris supposed to have existed on the surface before the Glacial Period seems to me an assumption. Many parts of the great insular mass of crystalline rock in Central France had almost certainly not been under water from a very remote epoch, a large portion of it certainly not since Miocene times; yet there is no great amount of surface debris here, and I suppose we may dispense with an ice-sheet for Auvergne? Surely also, as soon as a layer of a few feet of debris had formed on the surface, it would greatly pro- tect the rock beneath from all agencies but those of percolating water ? Again, with regard to Mr. Goodchild’s explanation of the absence of ice-marks from the higher parts of mountains (p. 360). If a glacier is an erosive agent of such power, as he supposes it to be, a very limited duration of contact with the upper rocks ought to suffice for imprinting its “handwriting on the wall.” Thus, making every allowance for greater exposure to weather, we ought now and then to find the blurred remnants of these inscriptions. I have climbed more than most men in the regions of glaciers, but never saw them. To my eyes the transition from weather-worn to ice-worn rocks appears usually rather abrupt, and at a regular height. Finally is there evidence at all that glaciers possess this immense 428 Correspondence—Mr. J. A. Birds. erosive power? I have shown (Quart. Journ. Geol. Soc. xxvii. 312; xxix. 882; xxx. 479) that in several districts of the Alps there is evidence that the glaciers have descended important valleys, filling them almost down to the level of the present torrents, yet have been incompetent to modify their principal features, which are most characteristically those of fluviatile erosion. This argument, I venture to assert, has never been met. Hvery year that I travel gives me fresh instances, and during the present summer I have met with one or two other curious facts bearing on the subject of glacier erosion, which I hope to be permitted to lay before the readers of this MaGaziIneE in a month or two. | I have thus ventured to indicate some of the reasons why Mr. Goodchild’s arguments fail to convince me. If they seem rather curtly stated, I must ask him to believe it is because I am trying to discuss in a letter a subject which requires a lengthy article. T. G. Bonney. St. JoHn’s Cottecr, CAMBRIDGE, Aug. 9th, 1875. THE POST-PLIOCENE FORMATIONS OF THE ISLE OF MAN. S1r,— Will you kindly allow me space for a brief rejoinder to the articles by Mr. Horne and Mr. Kinahan in the July Number of the GerotocicaL MaGazine ? 1. Allowing, as Mr. Horne says, that intercalated beds of sand, gravel, etc., are of common occurrence in the Lower Boulder-clay, still I cannot see that this entirely destroys the force of the argument a priori, that they would probably be of more frequent occurrence in a deposit like the Upper Boulder-clay, which was formed when the cold was less severe, and warm seasons oftener to be expected ; and therefore that the highest beds in the Isle of Man, which Mr. Horne considers Lower, are, so far, more likely to be Upper Boulder- clay. 2. Although it may be true that the glaciers of the post-sub- mergence period were confined mainly to the upland valleys, and therefore that moraines might be all the memorials to be expected of them, still the sea, both before and after the second continental period, must have contained ice in sufficient quantity to produce a thick de- posit of clay, such as in Lancashire, for example, is found extending from an elevation-of above 1000 feet to the cliffs on the sea-coast (see Geol. Survey Map 91) ; and it was principally to marine coast- ice, and not to glaciers, that I attributed the Upper Boulder-clay in the Isle of Man. 3. No doubt Mr. Horne is right as to the general characteristics of Lower Boulder-clay in South Scotland, viz. that it is a tough clay with an abundance of ice-marked stones, without stratification, and without shells. But even this true Lower Boulder-clay, or Till, varies according to the nature of the rocks from which it is derived, and it was with the Lower Boulder-clay as it appears in the cliffs at Blackpool, and not in Scotland, that I compared the deposits which T have taken to be such around the point of Ayre. If, however, they should prove not to be Lower Boulder-clay properly so called, nor Correspondence—Mr. J. A. Birds. 429 one of the intercalated beds with sand and gravel, they might at least easily be a portion, probably a lower portion, of the Middle sands and gravels, and so still the lowest Post-Pliocene formations in the island. It seems, from what I have learnt from Mr. Horne’s and Mr. Kinahan’s papers, as if there was a different division of the glacial series recognized by some geologists in Scotland and Ireland, from that adopted by the Geological Suey for the north-west of England ; the former consisting of 1. Lower Boulder-clay. 2. Upper or Moraine Boulder-drift. 3. Kame or Esker Drift.! the latter of 1. Lower Boulder-clay. 2. Middle Sands and Gravels. 3. Upper Boulder-clay. and it would. certainly be a point of some interest to determine to which order, or if to either, the Post-Pliocene deposits of the Isle of Man conform. But I think this must be decided by stronger evidence than that of the section at the southern end of the island to which Mr. Horne refers, and with regard to which his words admit of a double doubt—first, whether the underlying formation is really an Upper Boulder-clay, and not a Lower; and secondly, whether the clay with shells there is certainly identical with the shelly clay in the north. It must be decided, if not by direct evidence of superposition, at least by further probable evidence of such superposition, and also, as far as possible, by that of Molluscan contents. Do the shells of the Isle of Man deposits resemble more those of the Blackpool Middle sands and gravels, or those of the Clyde and Forth basins (of a more Arctic? character), with which Mr. Horne identifies these beds ? With regard to Mr. Horne’s lithographed section, it seemed to me, though on slight evidence, when on the spot, rather as if the red clay of the north of the island, in the bed of the Ballure stream, passed under the clays and gravels which the lithograph represents as Lower Glacial. In answer to Mr. Kinahan, I need only say that I have used the term ‘“ Glacial Drift ” in the sense in which I find it used (or at least language which implies such a use of it), by the highest authorities from Forbes till now, that is, of Drift formed whether by ice alone, or by ice and sea together (i.e. Marine Glacial Drift), during the * Glacial Epoch. No doubt much glacial drift in all ages, including that of its first formation, has been reconstructed in the manner explained by Mr. Kinahan, but, with deference to him, it is difficult to believe that extensive deposits like the Middle sands and gravels, and the Upper Boulder-clay (in Lancashire and Cheshire), have alto- gether or chiefly, been formed in this way. These would still seem 1 Mr. Kinahan and Mr. Horne identify these with the Middle or ‘“ Marine” (Irish) gravels, though I had been led to believe that the difference between them was sufliciently marked by the presence of shells and chalk-flints in the latter, and their almost entire absence in the former. (See. Gzou. Mae. Dec. 1869, p. 544.) 2 See Gzou. Maa. Dec. 1869, p. 548. 430 Obituary—Prof. Deshayes. to be attributable rather to icefloes and icebergs and to coast-ice and glaciers depositing their moraines in the sea; and therefore would | properly come under the description of Marine Glacial Drift. Drift, however, which has been reconstructed since the Glacial Epoch could not of course be considered glacial, but would perhaps be appropriately distinguished as “ glacialoid.” The question, however, of the nomenclature of Glacial Drift is quite beside that of the order of the deposits at present understood by that term. I regret that I should seem to have misquoted Mr. Kinahan’s © letter ; but I think, for I have not the Numbers of the Guo. Mae. at hand, he must have misunderstood me, as I was quite aware that he admitted an Upper Boulder-clay in Ireland, but not one above the Middle gravels, which was the only one to which I referred. J. A. Brrps. Trensy, dug. 3rd, 1876. (GsSn LIM UNAS Sea PROFESSOR G. P. DESHAYES, For. Mems. Grou. Soc. Lonp. GERARD Pavt Dusnaves was born at Nancy, 13th May, 1797, his father being at the time Professor in the Central School of that city. He was educated at Strasbourg, and came to reside in Paris in 1819, where he commenced the study of fossil shells, for which in after years he became so justly celebrated. Among other foreign explorations, he visited Algeria, and sub- sequently published the results of his expedition in a work remarkable alike for the beauty of its illustrations, as well as for its high scientific value. A careful study of his extensive collections of Tertiary shells (greatly facilitated by his intimate acquaintance with recent species) had suggested to Deshayes the propriety of dividing them chrono- logically into three great groups, according to their relative ages. These groups were found to agree, in the main, with the divisions arrived at by Lyell, and to which he subsequently gave the names _ of Hocene, Miocene, and Pliocene. To give weight to this classifi- cation, Lyell induced Deshayes to prepare a series of tables, which appeared in the third volume of the first edition of the “ Principles,” in 1830. Deshayes’ collections served as the basis of his great work, “ On the Fossil Shells of the Environs of Paris” (published from 1824-387, and the subsequent supplement extending from 1856 up to 1867), forming eight great quarto volumes. He published an Elementary Treatise on Conchology; and he revised, with Professor H. Milne- Edwards, Lamarck’s Histoire des Animaux sans Vertebres, and Ferussac’s Histoire des Mollusques Terrestres et Fluviatile. He pre- pared the Catalogue of the Veneride for the British Museum. He also published numerous Memoirs, both separately and in various scientific journals. Obituary—W. Jory Henwood. 431 M. Deshayes was one of the original founders of the Geological Society of France, of which he was several times President. The decoration of the Legion of Honour was conferred upon M. Deshayes in 1837. His fine collection of Tertiary fossil shells was purchased by the French Government for £4000, and is now preserved in the Museum of the Ecole des Mines, Paris. M. Deshayes was appointed in 1869 to Lamarck’s Chair of Natural History in the Muséum d’Histoire Naturelle. So long ago as 1841, Prof. Deshayes was elected a Foreign Member of the Geological Society of London. On three occasions (1836, 1856, and 1864) the Geological Society awarded M. Deshayes the proceeds of the Wollaston Donation Fund, to assist him in his long- continued researches ; and shortly after their completion, in February, 1870, they awarded him the Wollaston Gold Medal, “as an expression on the part of the Society of the high estimation in which his services to Paleontology and Geology, especially in regard to the classification of the Tertiary formation, are held by the the geologists of this country.” ? Perhaps the highest commendation of Prof. Deshayes (from one who was intimately acquainted with him for many years) is that he “found him always desirous to communicate all the information in his power to those who asked it from him.” ? M. Deshayes died on the 9th June, 1875, in his 79th year. WILLIAM JORY HENWOOD, F.R.S., F.G.S. ANOTHER veteran in the great army of Science has been lost to its ranks ; one whose contributions to mineralogy and whose acquaint- ance both with the theory and practice of mining and the mode of occurrence of mineral veins has made his name known and respected by both scientific men and miners all over the world. William Jory Henwood, born at Perron Wharf on the 16th July, 1805, was the son of Mr. John Henwood, sprung from an ancient Cornish family at Levalsea in St. Ewe. His father, like many others, had lost largely by his connexion with the first Cornish Silver mine, the “ Huel Mexico,” which raised. about £2000 worth of ore at a far larger expenditure. Young Henwood began life in 1822 as a clerk in the office of Messrs. Fox and Co., of Perron Wharf, where he continued five years. Happily the nature of his employment enabled him to commence those investigations into the metalliferous deposits of Cornwall and Devon which occupied his undivided attention for nearly 50 years. The first mine he visited underground was the Wheal Herland in Gwinear in 1825, and his first scientific paper was read before the Royal Geological Society of Cornwall in 1826. 1 Extract from speech by Prof. Huxley, LL.D., F.R.S., President Geol. Soc. 1870. See Quart. Journ. Geol. Soc. 1870, vol. xxvil. p. xxvi. 2 Extract of a letter from Thomas Davidson, Esq., F.R.S., F.G.S., to whose kindness the Editor is-indebted for most of the facts regarding M. Deshayes’ life. 432 Miscellaneous. For the next 20 years communications from his pen, in every case the result of wide-spread observation and much patient thought, appeared in rapid succession in the pages of this and other scientific societies. The titles of no fewer than 55 separate papers by Mr. Henwood are given in the Catalogue of Scientific Papers published by the Royal Society, and a still longer list appears in the Bibliotheca Cornubiensis. The whole of the fifth volume of the Transactions of the Geological Society of Cornwall was in 1843 devoted to Mr. Henwood’s observations “ On the Metalli- ferous Deposits of Cornwall and Devon” (512 pp. and 125 plates and tables). In 1871 the same Society devoted their eighth volume to the publication of Mr. Hen- wood’s Observations on Foreign and Metalliferous Deposits, a volume even bulkier than its predecessor. ; In 1832 Mr. Henwood was selected as Assay Master and Supervisor of Tin in the Duchy of Cornwall, an- office which he held until the coinage duties were abolished in 1838, when he retired on a pension. In 1837 the Institution of Civil Engineers awarded him the Telford Medal for his paper on Pumping-engines in Cornish Mines. In 1840 he was elected a Fellow of the Royal Society. In 1843 he went to Brazil to take charge of the Gongo Soco Mines. From Brazil he repaired to India in 1855, to report on the metalliferous deposits of Kumaon and Gurhwal in North- Western India. He finally retired from active life in 1858, spending his latter years in Penzance. In 1869 he was elected President of the Royal Institution of Cornwall, to which he communicated numerous papers and addresses. So lately as the present year he was presented with the Murchison Medal by the Council of the Geological Society of London. He died on the 5th August in his seventy-first year, highly esteemed by all who knew him. Cornishmen may well be proud to claim him as one of their own countrymen.! MISCHUIGLANHOUS. Mr. Witiam Davies, British Musrum.—It will be a source of unfeigned satisfaction to all geologists to learn that Mr. William Davies, who has devoted more than thirty years of his life to the service of the Trustees in the Geological Department of the British Museum, has at length been appointed an Assistant, and will hence- forward occupy a recognized position in this scientific Department. It will not be forgotten that Mr. Davies was awarded the first Mur- chison Medal by the Council of the Geological Society, in 1873, in recognition of his valuable services to Paleeontological Science. Those who are acquainted with Fossil Fishes will be able to testify to his great knowledge of this group, which has rendered this part of the National collection especially perfect. His labours in reconstruct- ing the Fossil Mammalia of the Pleistocene Brick-earths of the Thames Valley, and his Catalogue of the fine series of specimens from these beds, collected by Sir Antonio Brady, F.G.S., and recently acquired for the British Museum, attest his extensive practical acquaintance with comparative anatomy. We trust his life may be prolonged and his services continued for many years to come, to his own honour and for the good of science. 1 Drawn up and abstracted from an elaborate memoir kindly sent by W. Prideaux Courtney, Esq., to the Editor. Supplement to the Geological Magazine, SEPTEMBER, 1875. ACTION OF DENUDING AGENCIES. ABSA CIVAND (CONTENES OF LECIURE, Gc: 10. Il. March 22, 1875. By A. Tytor, F.G.S. PAGES . Atmospheric conditions at the time of arrival of man upon the earth very different to present conditions, in fact a pluvial period... AS 7 . Method of formation of rock basins or deep lakes in mountainous districts by excavation out of solid rocks by lake glaciers ... 438, 446 . New explanation of mode of excavation by glaciers, dependent or consequent upon the expansion of water at the bottom of the lake during the act of freezing ; this water not being produced by the sun’s heat, but by the friction of ice upon ice during the motion of the glacier. Fig. I . 439 . Glacier motion described and compared to that produced by building upon a marsh a tower or railway embankment = 440 . Deep lakes are never found except close to mountains, as represented IBIS, Boos Pe 439, 440 . Machine for proving the amount of friction of ice upon ice, or what is termed the co-efficient of friction. Fig. 3... 441 . Experiment on velocity of sliding bodies, proving ‘that velocity is is nearly twice as great when the weight on one of two similar sized pieces of ice is increased eight times. Fig. 4 442 . Regelation only occurs when there is a thin ae of water between two pieces of ice, that is, when the quantity of water is so small that part can be evaporated or conveyed by endosmosis into the pores of the adjacent ice as if it were a colloid, peace heat from the remaining water : 439, 441 . Rivers. Absence of a special work on rivers remarkable, when there are. so many books on glaciers. It is important to know the quantity of siliceous matter rivers push annually out to sea, as this is probably twice as large as the material they carry off the land in suspension. I estimated in 1853 that the whole land of the globe was lowered one foot in nine thousand years by river action ; but by conputing the siliceous matter pushed out to sea, I correct the calculation, and esti- mate the average denudation at one foot in two thousand years ...443, 469 Explanation of uniform mean motion. Proof by observation that the mean velocity of every navigable river is nearly constant throughout its course, on any day, or that increase of quantity flowing has an equal effect in increasing velocity that decrease of slope has in decreasing velocity: Fig. 9. The equation to uniform motion is given page 447, 466 Longitudinal section of Rhine, showing that hard strata raise the flood level above the theoretical curve, and that soft strata allow the flood DECADE II,.—VOL. II.—NO. Ix. 28 434 Abstract of Lecture. PAGES level to fall below the theoretical curve, a parabola with horizontal axis, Figs. 5 and 5A. ‘Transverse section of Hirwain Valley, Fig. 58, also in parabolic curve, from my own survey wae ae A444, 12. Drawing from observation of a stream at a small Japa, Fig: 6. Ditto, Fig. 7, of a stream with the same quantity flowing at a steeper slope, showing the difference of stability or stand up of a running stream repr esented by the difference of depth of water under the same circum- stances of slope. Hitherto, slope has often been alone taken into account as the cause of velocity, without calculating the quantity flowing. Explanation of symbols ae : ced 4A, 13. Different velocities of streams of different sizes 3 hare, that with about twelve times the quantity flowing at the same slope, the velocity was increased about two and a half times, or as the cube root of the in- creased quantity. Fig. 8.. 14. Plan of Mississippi, showing the width at twenty- two different towns, the curvilinear river course being represented by straight lines. All navigable rivers decrease in width and increase in depth until they approach the sea. A bar is formed by the opposing current of sand or mud moved along the bottom of the river up a steep gradient (10 feet ina mile in the Mississippi), meeting the sand continually brought up by wind waves from the sea. The opposite forces encounter at the bar ; a great quantity of mud and sand overcomes the opposition, and is carried along shore. Colonel Tremenheere found by experiment that the material projected into the ocean by the Indus travelled hundreds of miles along shore, and was found in the harbour of Kurrachee. The long-shore current was often one mile per hour, and continued in the same direction. Figs. 11, 12, and 13 : 15. Plan of Amazon, a river 2,000 miles long, with the acute angle junctions of tributaries at the extremities near watersheds, and the other junctions nearly rectangular. The junctions are rectangular particularly when the main stream is very large, and the ee ee in alluvium. Fig. 14.. 16, Representation of the junction of the Red and other tributar y rivers at acute angles with the Mississippi. The great river is deflected from its course by the impact of the Red River, and flows in a line, the resultant of the two forces. A main river is merely the junctions between tribu- taries. It has no water of its own, and its position in space is the resultant of alernate and Sere forces of side streams throughout its course. Fig. 13 ... 17. Representation of the same » streams with rectangular junctions, to show how absurd such an arrangement appears. Fig. 14 ... 18. Law of alternate headlands and coombs (coombs are steep dry, or wet valleys). These are found along every valley in the world, formed with more or less regularity. ‘The coombs and slopes are often originally excavated by the water issuing from springs along the tops of the un- stable and impermeable strata cropping out along the sides of the valleys. The spring water dislodges the face of the stable or per- meable strata, and leaves the bared edges of the rock ata steep angle, which edges in the impermeable strata or clays are sloped. Fig. 15 represents a valley in chalk, where the strata are of uniform permea- bility ae 19. Delia of Danube, showing n main stream, dividing first near the rocks of Toultcha, where there are no longer any side streams or hard rocks to keep the river from branching. Fi ig. 17 : 20. Main river deflected after receiving a branch. Fi ig. 16 21. Velocity in a main stream of two metres per second, shown in diagram 445 446 . 447 448 . 448 449 - 449 450 » 451 451 Abstract of Lecture. 435 PAGES from observation, reduced in a branch one-half of the size, to 1°6 metres per second, and again to 1°27 metres per second, ina branch one- quarter the size of the main stream ; all the streams at the same slope. This gives an idea of the effect of weight in increasing velocity at the same slope. If the Nile was divided higher than at present, the rise would occur earlier and be higher, as the stream would be slow. The reverse would be the case in the Rhine. If that river was prevented from dividing at its delta it would flow in a swifter course to the sea, and keep a deep mouth open in the sea so as to admit large ships ... 452 22. Mount Tabor, Fig. 19, from a photograph. The outline is compared with a dotted line representing a binomial curve, obtained from the co-efficients of (2 + 4)'°. Every symmetrical hill has a convex top and a concave bottom, and is steepest in the middle. This form, so constant in nature, is caused by the watershed being flat, so that little water flows upon the high lands, above ground. Springs escape at the middle heights of the valleys and widen valleys. The action of sub-aerial fluvial and pluvial denudation is not so much to lower watersheds as to widen valleys. ‘Thus, ina great denudation of this kind the maximum height of the mountains and watersheds and the depth of the valleys may be constant.* The valleys could be enor- mously widened, and the mountain masses thereby emasculated, with- out the average height of the land been materially lowered. This, of course, supposes that as much material is removed by denudation from any level above the mean as from another below the mean, or rather, that the relative removals balance each other, leaving the mean and maximum heights of the land untouched. For this reason the land can never be all removed below the sea level ie pep aie A representation of the binomial curve or curve of denudation, showing how it is set out. Fig. 20. A symmetrical hill curve 588 ae 23. Representation of form of hills in different position, to show that all the surface curves can be represented by binomial curves. The Fishback Hill, Fig. 21, is a very common form, as naturally the watershed is not often exactly intermediate between two lines of drainage. Figs. 21 A, 21 B and 21 C, are sections in different posi- tions of the Fishback Hills ate ae eg Be Ass 453, 454 24. Hills of Lower Greensand, Fig.21p, and hills of glacial drift in Sweden, can also be represented by binomial curves. Fig. 21E F Ae 25. Figs. 23 and 24 represent the case of water passing through fissures in hard rock and washing away the clay below, and causing the formation of Ecclesbourn, which is the type of all valleys. The hard rocks falling into the brooks of any district pave them, and prevent the sands being washed away. This is the cause of Crowborough Beacon standing 900 feet above the sea: without the iron-sand rock, this hill would have been washed away by its brooks. The position of rock and clay at Ecclesbourn, on a very small scale, is that of Niagara on a very large one. The slopes of surface or contour of the land is terraced or shaped into alternate walls and slopes, in consequence of the water escaping over the clays, levelling the wet surfaces of clay, but leaving the rock or sand standing up at a steeper angle than the clay, because less water passes over it and its stability is greater. This is the form of the buttress in architecture; that is, the wall and slope used is the form best adapted to resist atmospheric action—it is the form of 452 454 * Mr. Croll has stated without apparently considering the geological evidence, that all land can be reduced to the level of the sea, and he calculates the time by, what I consider, an unsafe method. He has copied my method of 1853, of computing denudation in other respects, without adding any improvement. ae 2 436 Abstract of Lecture. PAGES stability. Directly vegetation covers the slope the surface becomes per- manent. The great floods in France have been promoted by the woods being cut down. The roots would have retained the soil and the rainfall. The channels being choked by soil washed in, the cross sections are reduced, and enormous floods are the consequence. The process of denudation by water passing through the permeable bed (A, Fig. 23, page 26, and a, Fig. 24) eventually causes the destruction of the strata and the cutting back the valley By the stream. Also see Fig. 28, Black-Gang Chine... aS + 455,456 26. Denudation of ths Weald and Fommneitionn of its river gorges. The process of gorge formation is illustrated by Fig. 25, the current being directed in a particular direction by unequal elevation of the strata. Arthur Severn, the well-known artist, has embodied the theoretical view of Fig. 25, in two excellent views, Fig. 27 and 28, representing the course of the denudation of the Weald gorges 27. The consequence of unequal rainfall at different times of ihe year is illustrated in Fig. 31 from observation, causing a constant change of bed of rivers and horse-shoe bends, deposit occurring on the shallow side of a stream, and excavation on the deep side 28. Representation of a gorge cut out in soft strata at Black Cane Chine by a stream—a type of the denudation produced in hard strata during the pluvial period. Fig. 29. All contours of gious are really suc- cessions of walls and slopes side : oy 460, 29, A gorge cut in limestone, probably ional ee bp an underground river at Dovedale, Derbyshire, forming successive walls and slopes .. 30. The section across a series of parallel valleys cut down to an ‘ane meable bed is illustrated by Fig. 35, page 32. It is evident that now rainfall, or pluvial or fluvial denudation, will not much affect the level of the watershed or of the rivers. All the denudation will occur at the level! where springs escape, and all the valleys will be widened but not be deepened, and the main level of the land above the sea will not be affected to any great extent even by a great denudation. The drawing represents a section through the Wealden Valleys ; the position of the Weald or galt clay at unequal heights above the sea, east and west, determines the course of the rivers, combined with the north and Roath slope of the strata. The effect of a transverse, or east and west flexure of 20 feet in a mile, modifies the effect of a north and south flexure of the gradient of 1,000 feet in a mile, as at Guildford . 31. The fact of the exceed notion of the weight of the. sun, for cinta there is no careful calculation hitherto, is mentioned, Be ee on page 33. Pluvial period due to sun’s influence BC : 32. The difference between an ellipse, Fig. 36, and an orbital curve, Fig. 37, is explained on pages ... an 467, 468, 33. Important element in calculating the denudation of any particular area by the amount of material carried away by rivers, has been hitherto omitted. The sand moved out into the sea beyond the mouth of the river, and carried along the coasts, appears to be twice as much, at a moderate calculation as the material removed in suspension. My estimate of present mean denudation all over the world is one foot in 2,000 years,, 34. New view of the action of the barometer as indicative of the variation of the motion of the atmosphere, and not mere weight of the atmo- spheric columns. The effect of rain on the barometer is only the record of motion in the atmosphere, Motion always affects eae e 35- List of scientific papers, by A. Tylor... a ‘ Son + 457 + 459 465 . 461 . 462 .-- 463 469 . 469 . 470 Lake formation by Glaciers. 437 ATLIBRBID TAILOR, IES, ON THE ACTION AND FORMATION OF RIVERS, LAKES, AND STREAMS, WITH REMARKS ON DENUDATION AND THE CAUSES OF THE GREAT CHANGES OF CLIMATE WHICH OCCURRED JUST PRIOR TO THE HISTORICAL PERIOD.* (March 22nd, 1875.) Y lecture will relate to the consequence of the flow of water and ice, that is, to the motion of rivers and streams and of glaciers, and their effect in producing erosion or denudation, as it is called, of the surface of the earth. I hope to prove, by diagrams, the effect of the excessive rainfall and snow- fall in former times, when the earth received its sculpture or superficial configu- ration. The extent of the ancient rivers and glaciers is shown by the dimensions and shape of the present hills, lakes, and valleys. I believe, and I hope to convince you, that the present forms and shapes of the surfaces of the earth are due to events which happened at or about the time of the arrival of man, when atmospheric conditions were extremely different to those at present. These views I have held for twenty years, and they are, of course, entirely contrary to the views of the late Sir C. Lyell, who never admitted a pluvial period.+ Then I do not think, inthe present theory of regelation of ice of Faraday (in 1850) and Tyndall (in 1857), that these writers have taken into account all the circumstances of the case. (2) The formation of great and deep lakes is a great difficulty ; it has been asserted by Professor Ramsay and others that some of the Swiss lakes were formed by glaciers, but the present accepted theory of the motion of ice does not, I think, give a possible explanation of the formation of large lakes, thirty or forty miles long and 1,200 feet deep. Such a work involves the carrying out of a vast quantity of material from the lake bed, against the action of gravity. (See Fig. 1.) I hope to show, by taking account of what I think has been omitted or neg- lected—referring to Fig, 1, which I will now describe—that an upward and forward movement would occur in the lake-glacier, due to the greater weight at the upper end. Then I think one consideration has been omitted, viz. the effect of the friction of ice, during motion, in producing heat, by which a large quantity of water is produced. Fig. 1 is a glacier one mile thick, occupying and filling a lake 1,200 ft. deep, and excavating it at the rate of half-an-inch over the whole surface in one year in the glacial period. I think De Charpentier (in his ‘‘ Essai sur les Glaciers,” 1841) was right in supposing that water, freezing in the glacier itself, and expanding, gave motion to glaciers, although that is disputed. He worked with the great Agassiz, who discovered the glacial period in 1837. Playfair first discovered the geological importance of glaciers in 1802. The movement of a lake-glacier, I believe, is assisted by three different forces impelling it ferward,/and retarded by two resisting forces, as shown in my diagram. The impelling forces are, 1. Gravity, measured by the slope of top surface. 2. Pressure from behind, due to the heavy weight of glacier behind acting on the ice which is treading in water, and causing the front end of the glacier to rise, just as the weight of the Victoria Tower in Westminster caused the bed of the Thames to rise ; or as a weight applied in the formation of a railway * [This Lecture was illustrated by some new experiments on ice, and by reference to new ex- periments made by the Lecturer to prove the amount of ice thawed by friction of icé upon ice, which is an important and new element in explaining glacial motion. ] +A. Tylor, Quart. Journ. Geol. Soc.,vol. xxv., pages 9 and 63, 1869; vol. xxiv., page 105, 1868, 438 Action of Lake-glaciers. embankment on a morass, caused upward motion of the peat and bog often as far as the marsh extends. ay eee 3. The effect of the congelation of the water produced by the friction of ice upon ice expanding the lower part of the glacier, and producing the forward motion. ‘This third cause was De Charpentier’s principal source of motion. The two resisting forces are the friction against the bottom and the resistance of the mass, and the having to lift the bottom of the glacier against gravity. The chemical explanation has yet to be given, I think that meets the case entirely. ; (3) The effect of evaporating ice and water even at low temperature in produ- cing increased cold has not been alluded to, nor the absorption of water by the FIG 4 Lake Glacier supposed to be excavating atake at the rate of ome tm a Yeap . NX SAC? Present level \“ of Lake, A.TYLOR. BEL pores of ice. This is also an action, I believe, eqtivalent to evaporation, and causes great abstraction of heat from the surrounding ice, and great cold at the surfaces, where absorption occurs. And this cold converts a certain quantity of water into ice, joining surfaces of ice together at 32 degrees. That the now well-known theory of regelation is a correct one I do not doubt. That heat is produced by the friction of ice upon ice was proved by Sir H. Davy. Thawing has been said to proceed at lower temperatures under pressure by Professor J. Thomson, but little observation was adduced in proof of this in the Papers published in 1857 and 1858 in the Proc. Roy. Soc. Edin. It is quite possible that ice may not freeze at a temperature below 32 degrees under pressure ; as we know water can be cooled much below 32 degress, if perfectly still. When motion ensued, the production of heat by the friction of the particles would warm the water, and raise the temperature at the moment to 32 degrees. The Lake-glaciers enibosomed in Mountains. 439 mean temperature at the surface, where the old ice is in contact with the new ice forming, may be 32 degrees. In the ordinary regelation experiment the wet surfaces of ice are put close together, and a portion of the water is evaporated into the pores of the ice, and heat is abstracted, so that the remaining quantity of water is frozen uniting the pieces of ice together. Regelation does not occur when there is a thick film or sheet of water between the two surfaces of ice, unless the ice is much below 32 degrees, or there is pressure producing currents and evaporation. Ice, although not exactly a colloid, may have cells which admit of exosmosis and endosmosis in the gaps between the internal crys- talline surfaces.* There may be one-tenth of the whole bulk of the ice occupied by such cavities. This could be proved by freezing an hydraulic press of excessive strength containing a small film of water and an observing tube When a mass of water was frozen in a mortar, a shot of 3 lb. weight was ejected 415 feet.¢? No pressure gauge was introduced in this Canadian experiment. Mr. Ruskin, on the 11th of this month, explained his views of glacier action, and interested you very much. ‘The subject to-night is almost a parallel one, but I cannot treat it, unfortunately, with the power that Mr. Ruskin applied ee Te toit. Mr. Ruskin’s views on the subject of the viscosity of glaciers agree with those of Prof. James Forbes, and are different to those I shall state to-night. (4) Glaciers are but frozen rivers, and they obey the same great laws of motion that rivers follow, although the advance forward of a large river is as much in a second as that of a large glacier ina week. No one has constructed a large glacier artificially to experiment upon ; while Darcy and Bazin experimented on the flow of water in many kinds of channel. See their ‘*‘ Recherches Hydrau- liques,” Paris, 1866. * On page 4o, Note 1, the action of ice almost resembling a colloid body during the act of regelation is described. + Ganot’s Physics, page 261. 440 Laws of Glacier Motion and Regelatzon. Ice experiments could be well tried on a large scale in Switzerland, Norway, Russia, or in Canada, where the temperature of the air is low. By your permission I would attempt a new explanation, to show a possible mode in which lakes high above the sea level are formed by the action of ice; that is, by glacial action. The motion is due to ws a ¢ergo, like the slope movement of marshy ground when loaded by an embankment. (5) The outlets of all such lakes in mountainous districts are high above the lowest part of the bottom of the lakes themselves. Deep lakes as Fig. 2 are always embosomed zz the mountains by whose glaciers they were formed. Deep lakes are purely the mechanical consequence of high and steep mountains from the poles to the equator. Given the position and depth of the lakes, it is often possible to predict the position of the mountains. I have shown, in Fig. 1, a lake which you may suppose to be that of Zurich or Lucerne. The outlet, or outfall, of this lake is in hard rock, and it is evident that the whole of the material which formerly occupied the lake must have been, at some time or other, excavated, or dug out, as it is not possible to suppose any other hypothesis. I hope to show how glaciers—thatis, ice holding boulders or rocky blocks firmly in its grasp, dragging along the bottom —can perform this difficult operation. As glaciers have a considerable motion, although a slow one, these rocks shown in the diagram are like tools or shears, which plough up the surface of the earth and push the loosened material up a slope into the outfall. It is possible to explain by this drawing how a glacier, having hard boulders firmly embedded in the bottom, can drag these along the bottom and cut out the rock and push it up the lake-bottom against gravity, over thé outfall, from which it would be removed in the usual way, if the glacier can move forward from top to bottom. In the glacial period the mean temperature of the ice must be assumed at ten or twenty degrees below freezing, although now near the freezing point in modern glaciers. There is one condition necessary to be admitted, and that accords with observation—viz. that the bottem of the glaciers must be wet, and at 32° Fahr., or about that temperature. If colder, the ice would freeze to the bot- tom and no motion would ensue, and if warmer the ice holding the boulders would be thawed and there would be no erosion taking place. All observations show that all modern glaciers move in constrained, and not in free motion, and more in summer than in winter, and that there is a thin wet or watery surface between the glacier bottom and the ground of the valley it moves in. There are greater deviations in glaciers from their mean motion than in rivers from their mean motion, but still glaciers move forward in a mass, and the front ice is not overtaken by the back ice. Now the fact of the greater motion in the day than in the night, and in sum- mer than in winter, is an indication that the greater the quantity of water present in the glacier the greater is the motion. The action of a quantity of water at the bottom of the lake, and in the fissures of the glacier, would tend to float the lake glacier to some small extent, or at least to place it in the unstable condition of marshy ground. We know that when a railway embankment or a large building is erected on a marsh, elevation of the surface of the marsh takes placg at a long distance from the point where the weight is applied. Tn order to render the motion of the lake glacier possible, such as that repre- sented Fig. I, we want a certain quantity of water constantly produced, and that part should soon freeze, so as not to increase the stock of water. I think the congelation-dilatation theory of De Charpentier, with some modifications, helps to explain lake glaciers. Although Sir H. Davy pointed out that ice rubbed against ice produced heat, yet this has not been taken into account in any of the theories of glacier motion, and I mention it now for the first time in a public lecture, that there is a possible source of heat to produce the water Experiment in Friction of Ice upon Ice. 441 found in all glaciers, arising from the friction of the ice in the glacier itself ; and that the act of regelation or freezing, accompanies exosmosis from the water into the cells of the ice, the evaporation of part of the water abstracts heat and causes the rest of the water to freeze. (6) I do not understand why this action has not been previously suggested, for by pressing four pounds of ice against, or by revolving two blocks of ice such as these, 8 inches in diameter, for an hour, 13 pounds of water can be produced, at a ternperature, much above freezing (Fig. 3). The ice was revolved in a metallic chamber, commencing at 32° Fahr., but the temperature soon arrived at 40°, on account of the heat transmitted from the ice to the air touching warm air entering the case, and from the water being warmed by friction between the two surfaces it lubricates. I found the friction of ice upon ice to be near that of oak upon oak, well lubricated. This experiment does not appear to have been previously tried, and should be repeated under varying conditions to arrive at the actual co-efficient of friction, and should be tried in the manner adopted by General Morin and others, and in a cold climate. Velocity of movement does not increase friction. Friction is dependent upon mass, dis- tance moved, and nature of surface. The co-efficient of ice is between o°1 and 0:2. i Sw? ; irr ll (i! Z WE ELTA TAA GT Hii! = \ i ci i The source of water at the bottom of a glacier is, I think, due to the heat generated by friction of ice upon ice, by the movement of the glacier to a great extent. The source of the subsequent congelation, I thiuk, is the evaporation of this water, and its reception by frozen ice. Hitherto the accepted source of the glacial water is only supposed to be that which may be obtained from the snow or ice on the surface of the glacier, melted by the sun’s rays, and falling through fissures to the bottom. Ice will evaporate at any temperature, forming vapour, which would pass into the fissures or fractures made by the ice breaking contact. I can only conveniently show that ice rubbed against ice rapidly, produces water freely, in such a case as my experiment. This experiment is somewhat different from the actual case of a glacier. Then regelation only occurs at 32° to the water adherent by molecular attraction to the surfaces of theice. When a lump of ice is surrounded by a mass of water at 32°, it thaws. It must, however, be remembered that, there is a certain amount of elasticity in ice when a great many yards of ice are set in motion by varying pressures of ice in the rear, and by gravity, when the tension or torsion arrives at a certain limit, fracture ensues ; the divided surfaces rub with great force against each other, and the motion of disruption, although not instantaneous, may be excessively rapid. _ Heat is produced by the friction of any solid against any other solid, and ice is no exception. This heat converts ice into water. No doubt part is imme- 442 Experiment in Velocity of Heavy and Light Bodies. diately taken up for regelation, but sufficient falls to the bottom through the fissures to lubricate the glacier, and when frozen to move the ice forward. Heat is also produced by the action of the ice moving boulders on the earth.* If the mean depth of the lake of Zurich (Fig. 1) could be increased half an inch in a year, that lake might have been comfortably excavated in 15,000 years, which is certainly less than the glacial period. (7) I propose to attempt first to prove to youa new law ascertained by experi- ment on motion of bodies down inclines in constrained motion, and thus to show you how much weight affects and increases motion. This law is most important to my argument. Then I propose to contrast the new experiment on constrained motion with the old experiment of free motion, where bodies fall at one velocity irrespective of their weights, that is zz vacwo, without touching any substance of any kind in their fall. This is shown by reversing a glass vessel exhausted of air, and holding a light and a heavy body. Bodies of the same.size and of different weights also roll at nearly the same velocity down an incline, as we see when the surfaces in contact are so small (as in spheres) that the motion approaches a fall in air, or free motion. [These experiments were then successfully performed in the lecture-room, by my son, J. J. Tylor, on a slab (Fig. 4.) Two pieces of ice of the same size and weight, slid at the same velocity. But when one was loaded to eight times the weight, it travelled twice as fast. ] FIG 4. I have before me an inclined plane of slate twelve feet long, two feet wide, down which pieces of ice of different weight will slide at different velocities, while spheres of the same size but of different weights have much the same speed. PThis new law—of weight increasing the velocity of bodies in constrained ‘motion in a definite proportion or ratio—has an important application upon the subject of my lecture, because it bears on the infinitely greater action of rivers and springs in former times, for the following reason : I find, by calcula- tion, that with twenty times as much rain, rivers may have swollen for a short time to 400 times their present volume, and then have eight times their present velocity, for the increase of velocity is as the cube root of the increase of weight of water flowing. The large currents arising from a very small slope in the surface of the ocean, are due to this law. Ocean water would move with one thousandth part of the slope of a small stream, if the ocean stream is one thousand million times the volume of the small stream. Ancient glaciers travelled many times faster than the present ones down the same slopes, and reached much lower levels in consequence. Modern glaciers are only one-third of a degree below freezing, but older glaciers were probably very cold. Certain theoretical consideration as to the effect of pressure in modifying the point of freezing have been accepted without sufficient experiments having been made ; and the present accepted glacial theory has been thus constructed, partly upon observation, and partly upon theory not confirmed by experiment, Laws of River Action. 443 which is unfortunate. There is no @ gviord reasoning possible in physical science. No theory has ever yet been established, except based on careful experiment, in any branch of science. I therefore submit even my imperfect experiments as much better than mere theoretical views. The results of observation haye, no doubt, corrected many erroneous views about the flow of water ; and when similar labours are expended upon ice, we shall obtain more accurate knowledge than at present. (8) There are many separate works on the theory of the action of glaciers, which are physical agencies of far less importance than rivers. The modern glacier theory turns on the experiment of regelation, that is of pieces of ice at 32 degrees joining together or freezing. This action I do not think has been sufficiently limited or investigated. Snow evaporates at very low temperatures, and this must be a source by which heat is consumed, and the surrounding snow cooled. Regelation only occurs when the quantity of water to be frozen is so small that the part that evaporates into the pores of the ice, cools down the rest of the water below freezing point by the heat abstracted in evaporating the first portion of the water. Regelation does not occur when two dry surfaces of ice are rubbed together, because heat is then produced by friction. The bubbles or cavities in ice, if they still contain air, all appear to contain air at a low pressure, or in an attenuated form. ‘The instant two dry surfaces of ice are rubbed together, part passes into water by the friction producing heat. RIVERS. (9) There is no special and exhaustive book written on rivers, but there are many reports of engineers on different rivers, such as Humphreys and Abbott on the Mississippi, Sir C. Hartley on the Mouths of the Danube, Revy on the La Plata, and chapters about rivers are to be found, in books of physical geography and general mechanics. Sir Proby Cauttley has published a most valuable work on the Ganges Canal. The absence of a special book on rivers describing the physical geography of their basins is surprising, considering the importance of the subject, scienti- fically and commercially, and also in an agricultural and sanitary point of view. In the Rhine, the hard rocks near Bingen have raised the flood level ra ft. I shall now try to prove to you that rivers cut out their beds and valleys to such a slope as is shown in Fig. 5, so as to attain such a curve and cross section as would give uniform velocity to the stream. Also that water generally travels down stream, in a navigable river, every day at one rate, not overtaking the water before it, and that glaciers have, from the same cause, the same ten- dency to uniform mean motion. Floods and avalanches are both exceptional occurrences. In Figs. 6 and 7 I give a diagram explaining uniform mean motion. I believe that a river is a machine for inducing uniform motion in the water flowing init. This is its real function, but it has escaped notice. So little was known by the public about the proper use and function of rivers, that it was supposed they were only intended for navigation, and for use as drains, and not worthy of a book to themselves. Their strncture is, however, I think, one of the most beautiful adaptations of simple mechanical means to perform a most complicated office in nature. It was not until Mr. Smee, one of the Managers of this Institution, stopped the Croydon Board of Health from turning a sewer into the River Wandle that it was ascertained that the common law of England was sufficient to pre- vent persons throwing what substances they pleased into rivers. The mechanism of rivers has not, I think, yet been understood, for everyone has appeared to have the full expectation that any river would dispose of any- thing that was thrown into it without further care. I am not going to attempt to-night anything more than to establish some general propositions about the action and the motion of water in rivers, and of ice in glaciers, and the causes it depends upon ; and to show how the surface 444 Parabolic Law of Rivers. of the earth is eroded, and how enormously increase of quantity of water or ice increased denudation or erosion of the land. I can prove that motion is in proportion to slope of channel and the quantity of water flowing, jointly, by the result of experiment. My diagrams, also, are correct representations of the forms and contours of cliffs and valleys actually caused by the action of rain and spring-water, rendering beds of sand and rock unstable on a surface bed of clay. The actual slip that has occurred is the measure of the instability, and is dependent upon the angle, the weight, and the lubrication by water of the surfaces sliding on each other. (11) For large rivers I take the Rhine (Fig. 5) ; but as the most remarkable rivers are in Asia, Africa, and America, I ought to allude to those countries, y FIG:5. RHINE. Height above the Level of the Sea at B 27527 x i} Do ad do, at § O, =x ipl AXE, Oo Length BM 28F-6mides 4m=01283. flood water levels from =——-————~— 3 a et eS 1 I | ! | Ty | | t | eos 3 | I H { I | | Jon Noh ling. eas aan Hectiecny I I MGM ate ae ah he i | s Rae = aes) wo! Wel! SI &! a SS S$! ai 9! Y! S| & ® S hy Sis See Ok 1 RY SS ee 1 5 i = & Se 88 SSRN 85: Sw SS! SS SO SS | 95 Vi H Sine hee ole Maa ! ine! | ( pee SiS! is ac.wn='622399 | 'e.xnt959355' | he xy = 1852470! | ei i 7 Hi TESS eal Tee T 7 7 = i . y 4 hoo qo i | nee sy | yl NS! : S} Sajal sl ter Si ao} N| tm! »! SI ol LENS (me SQ sersees § Ss S Ss ys 8 sak | at! Sa SPQsi oy i SO Ni Sis it IS ana &| VaR 5! 8) BD 3) S| y § & RY t S| s \! 1 |e ct Dt el (ens { pei penaer | if | il Meee GY ee ot ca tn pr ete wl | | *@en— oe bo oes ! } | Si | iam cil of fd Well Gye H | ey Sigil ae eum hy =k SH fot Net eager doe YY S [oR edict Sil} | PoSST St pi) | RIP Gee Nv N SH RAR TSE ee | &§| he rf | S81! ST ISS | S| se} 1%) 3S SnOaY 04 Sy u m.e om los) n=! 1D Dies ma SA meas ese oo Sa FO Aw. orn EY ea agen? tee ine Ss Boca Boe Sead ee . 0 Life} rs Wyo Ra ESO PUe OFM me @ ae des ml = = oSS5R SAS pty OOO FEET. ] 446 Lixperiments on Velocity of Water. slope. The Scotch Lochs have been attributed in 1862 to erosion, or excava- tion by glacial action, by Mr. J. F. Jamieson, the eminent Scotch geologist, who observed that boulders had been pushed by ice uphill 7oo feet (Quart. Jour. Geol. Soc., vol. xviii. page 178). Professor Kamsay, page 203 of. cit., takes the same view of the glacial origin of the Scotch Lochs. A An approach to uniform motion occurs in all rivers except when there are oods. : Fig. 5 represents the slope of the surface of a large river, corresponding closely with the theoretical curve, a parabola of the form drawn. Fig. 5A gives the deviation from the true curve, in feet, at 22 towns. The bed of the river acquires such a cross section that water may flow in uniform motion from one end of the river without the back water overtaking the front water in the river. Fig. 5B represents a transverse section of a valley. (12) Diagrams Figs. 6 and 7 represent a stream of water in an artificial channel, = 4 = <2 Ss Wee Tm SS : ‘ ay 2 3 BY E VARIABLE MOTION UNIFORM MOTION T=o'00165 at one point in variable motion, and at the other in uniform motion. TI is the slope per metre. In the experiments, the water ran about forty yards before it obtained uni- form motion. The depth of the stream represents what may be termed the stand up, or stability of the stream for that particular quantity flowing, and the particular slope and material of channel. A and a represent cross sections; V and v, velocities; O and q discharges; I and i slopes of the different channels compared. ‘The velocity increases as the cube root of the increase of quantity at the same slope, ane the velocity increases as the cube of the increased slope when the quantity flowing is the same. (13) Fig. 8 shows the different effect of depth and velocity for a certain small quantity flowing at the same slope asa larger quantity. The velocity in D channel when twelve times the quantity is flowing of that in B, is 2°3 times that in B. That is, the change is from 0°502 to 1'278, and 2°3 is the cube root of 12°167. Experiments in uniform Velocity of Rivers. 447 Fig. 9. The velocity from A to E is nearly the same ; that is, notwithstanding the difference of slope, the velocity is nearly uniform, owing to increase of quantity balancing decrease of slope. Q represents discharge per second in cubic metres. Fig. 6 to 9 and 18. A—Cross sections in square metres, V—Mean velocity in linear metres. | We Sc A=AREAse CROSS, SECTIONorCHANNEL : R=EMEAN, RADIUS. A SLOPE T=0'G0I5~ PER’*METRE (10) The equation to uniform motion, that is when velocity is equal andv = 7 is (4) Zi = : ( = + a ) See explanation at end of this pamphlet (page 36), Z and Phil. Mag., 1874, page 205. Fig. 9 is constructed by taking a number of channels, where observers had found by experiments the exact depth and cross section of the stream, in uniform motion when the velocity and depth were known. In fact if such channels were a +> : 170 ~ . wee PROPORTIONe-AREAS SLOFEI = 000490 WS oF y (erecta. = (CROSS SECTION) * a 2 ee ‘SLOPEI -0'00208 Venscecssesensa c= constructed at different slopes, and the quantity of water flowing at each chan- nel was regulated according to each case as described in the diagram, the water would arrive at nearly the same uniform motion in each case.* This is what happens on a real navigable river. As each tributary comesin * See note to page 39 referring to Fig. 9, uniform motion of navigable rivers. 14. 15 __------- Ghio.____ 2030 Beet, 2 Fe River Amazon, re Sy \ vAG es SS FIG (44 1: 3la 00 68.------- PPO YL May: <--=-=- === FO LV YTAlY SO HLOIM ONIMTHS WVHIVIC “Ol NWiId “IdISSISSIN Fart of Island 76-2. E Gaines:Landting Greenville.__> .-- 4700. a guafip sypbsuy fo apas “payna spuay pus sana) Ni S = & N S. S => w& S x ISS hyp SS S Sle & g! S Sy pie ss 7 | g nat Se 1 i Sauve, Crevasse +2202: Ss. 8 § AL a EE Ee —--}-i . S = S 1 L t finite. a REAL We BS Vort S* Phill |_| 24004 A : He len wen car teat Delta Se Head of Passes Uffremscue & AS He WN Z ‘ AB 2000miles ’ ii & BRB See page 39. Angles of Junctions of Rivers. 449 the slope of the main stream diminishes as the water increases (see page 467).* it will be seen that a near approach to uniform motion is obtained. There is an exception when very hard rock is met with, and backwaters. A tributary containing one-hundredth part of the water, but flowing at ene hundred times the slope, would enter the main river at the exact speed of the main river. I found, except when the shallows impeded the ships by reflecting waves back from the bottom of the river, in the Rhine, the quantity of coal used, and the speed attained by steamers, was uniform from near the mouth of the Rhine to Mainz. (Fig. 5.} Fig. 10 shows the great width of a large river 1,000 miles from the sea, and’ decrease in width as it approaches the sea. This is the general case with large navigable rivers. Directly the bar is passed a ship can sail hundreds of miles in deep water. Fig, II is a cross sectien, a thousand miles from the sea; = § 16 FIG 13. §17, FIG:I4. i= ae tunoseproT Maro River iy : Sanrio \. (ee i ; iS) -— L_____ ZB = w Dississippi — TRiver Actual junctions of Red River The sume river as tn Fig 13 joined S927, and other tributaries with alright angles to shew the Mississippi at acute angles. impossibility of the arrangement, Fig. 12 is a cross section near the Delta, proving the above law. Fig. 13 shows the natural junction of the tributaries of the Mississippi coming in at an acute angle. i Fig. 14 shows the imaginary junctions, supposing that in this river, the branches could unite at rectangular junctions, How absurd this appears. These drawings, made in 1871, are applicable to refute the theory advanced by Professor Ramsay, of the Rhine having reversed its course. The angles of tributary valleys are all such as would be produced by a river flowing in the present direction in the Rhine valley. * See Note 4, page 472. 450 Law of alternate Coombes and Headlands. Fig. 14A represents the Aniazon. The junctions in the mountains are at acute angles, but neat the mouth almost at right angles, as in all rivers. (18) Fig. 1§ is a drawing of :the alternate headlands and coombes observed on the sides of every valley in the world. Ss’ H’ s” HR” ———— —— ~ HORIZONTAL LINE Fig. 17 gives a plan of the Delta of the Danube, from the works of Sir C. Hartley. I give it merely to show that the cause of a river forming a delta is, that there is no longer in its course any tributary streams to keep the river in one channel by equal and opposite actions, from the brooks and rivers falling into the valley from alternate sides. Thisisthecase in all large rivers having deltas. Fig. 16. The line F C is the exact resultant of the unequal forces coming from F F and C A. Fig. 16 shows the effect of a tributary in changing the line of the main stream, which is the exact resultant of the forces if between the two streams joining, allowing for the respective differences of slope and quantity flowing in each tributary. If the tributary joined at 45° and was ~, the volume of the main river, it would deflect the main. stream one degree. Thus valleys are deflected from their direction, at the junction of tributary valleys. If the area drained by a great river is of symmetrical form, the river . will occupy the medial line, and be the resultant of the alternate and opposite forces of tributaries coming in on the opposite sides of the valley the main stream occupies. Fig. 18 is a case giving the effect on velocity in relation to different quantities flowing, by diverting a large channel into three channels, one twice as large as the other two. If the Nile was artificially divided higher up than at present, the current in the three streams would be much slower than at present, and the rise of river earlier and higher. Ifthe Rhine was prevented from dividing, it would flow out to sea in a good stream, so as to keep a passage open for large ships. From what has been seen in Fig. 8 and in other diagrams, although all these streams are at the same slopes, the mean velocity of the single stream before it divides will be greater than either of the others; and the mean velocity of the larger stream of the three will be greater than the two small ones, although Causes of Formation of Deltas. Adi (19) DIAGRAM SHOWING ‘THAT THE RIVER DIVIDES AFTER PASSING LAST HIGH LAND ‘ON ONE SIDE OF THE VALLEY, DANUBE. 20 KILIB. MOVLH. FIGIIT. i . es ere TSLAND OF. “TCHATAL ~“ a pe Ras ay a ee Ue ee ne a ox a FF ot he Rddemail WT 0 Rw, SOULINA 7 mouTH THE LEST Roexs on by TCHAIALDE S™ GEORGES Zep, FROM S/R.G.HARTL EY’S-DANUBE © (20) FIC 16. Pe Juuclion of a side stream wil @ main river. cen Causes of Shape of Symmetrical Fills. | all are at the same slope: this is owing to the effect that quantity flowing has uport velocity. Thus the velocity in F is 2°047; in H, 1°628; and in G and K, 1:274. (21) The channels in Fig. 18 are taken from four observed cases of water in uniform motion ; and if a channel was divided, as shown in Fig. 18, the above would be the real velocity. These new laws, already spoken of, might be applied in practice to such a river as the Nile to produce longer irrigation, Fig. 18. The mean velocity would be much reduced by dividing the river much higher than the present Delta. If three or more artificial channels were made, the streams would be much deeper and slower, although at the same slope as — = == === —s- FIG.19 SSS A ANS N MOUNT TABOR EON at present s and they would, and might, give an irrigation to the desert of Egypt, which would be of immense agricultural value, by causing an earlier and larger overflow of the Nile. The opposite is also true, that rivers joined at the same slope traverse with greater velocity. If the rivers of the Rhine Delta were joined so as to have one mouth, the Rhine would havea deep navigable mouth, and the stream, by its velocity, would always keep 22 feet of water at the bar. Fig. 20 is a diagram, the outline of which isa true binomial curve, This curve is shown in dotted line on Fig. 19, Mount Tabor, a type of a certain class of hills.* Another common form is also shown in Fig. 21 ; the hills assume the fish< back outline, the water-shed dividing the hill into unequal parts, y orgs iy Us Roe | Sere FiG.20 y ; 5 1 Bae | u t BUNOMIAL EuRvelDRAWN FROM THE ‘COEFFICIENTS OF @20/0\ AS ORDINATE ' P| 10 45 120, 210 252 210 120 45 19 1 The letters W W indicate the water-sheds. Fig. 214 and 21B are the binomial curves sect out in a proper manner from the coefficients of («+ 6) The water- shed being out of the centre in Fig. 21 produces a different form to Fig. 19. Fig. 29, p. 460, Black Gang Chine, represents the effect of erosion and denu- * The best general definition of a hillis that it is the convex portion of ground (B A £) lying above the concave part, or valley (6 V 7). ‘The springs burst out most at B and ZB, and make that part of the curve the steepest (sce Fig. 20). Although the surface of Fig. 19 appears smooth, it is no doubt a succession of small walls and slopes. Causes of Shape of Unsymmetrical Hills. 453 dation on a soft series of sand and clay-beds. Water enters by fissures and cracks along the upper surface of the alternate beds of clay and sand, when it reaches the air, where there is little or no weight of rock to keep the sand and clay from sliding, motion ensues, and the outer surface of rock or sand is dislodged. With eight times the quantity of water flowing along these unstable surfaces the de- structive effect might be as the cubes, or nearly 500 times as much as-at present. (22) I have shown what I believe to be the typical form ofahill, drawn froma photograph of Mount Tabor, Fig. 19. This hill has, I believe, a base of seven miles, and the surface has been eroded into the binomial curve, which is, I consider, the form of greatest stability. It is the form which gives the nearest possible approach to uniform motion of water on its surface. oe May Hill, seen from Gloucester, is a good example of this form, which is common to the hardest and seftest rocks, and even to clay and sand. FIG:2I. Watershed. FISH BACK HILL. Binomial Curve- See fig 15. A.TYLOR. BEL. Hills of drift have been drawn by Jamieson and others not quite so regular or uniform as those in Sweden. The drift hills, 40 feet high, on Hirwain Common, 200 feet above the river and two miles from Aberdare on the Neath-road, contain blocks of mill- stone grit many tons’ weight, and rolled pieces of old red sandstone transported on ice. The hills are in form like Figs. 19 and 21, but not quite so regular. Watershed. A L onyitadimal Section thra AB. FISH BACK HILL. FIG. 21” Binomitl curve. see lig 15* A.7YLOR . DEL. G Me \ Brook __—_ is my - : 1 10. 45 La elO 252 210 120 45 to 1 (23) Ifhills of glacial drift on Hirwain Common and in Sweden, Green Sand hills near Leighton Buzzard, and Sandown in the Isle of Wight, and in fact in all formations and countries, assume this form, it is because the formation of sloping surfaces in all hills and valleys is really the same natural process to be observed in an exaggerated form in most waterfalls. See Fig. 23, p. 456. The law for waterfalls is, twenty-seven times the water would produce as much destruction in a day as now occurs ina year. Water filling the brook at Ecclesbourn, pass- ng through the fissures and carrying away the soft clay or shale (which in most waterfalls underlies massive jointed rocks) produces instability ; and as soon as the surface of the clay is washed away, the rock is undermined and falls down. PoESCL ERE Sern 454 Uniform Contours (with variable materials) of Hills. Now these pieces of rock remain in the stream, and protect the underlying , beds. With torrents flowing, protecting rocks would be carried down, and valleys excavated with the greatest rapidity. Our hills were shaped by the same process. Fig. 21E represents a hill of glacial drift drawn by Erdmann. It is evident that the disposition of the internal strata does not materially affect the contour. From page 57 Formations de la Suede. 24. a@. Coarse Gravel. 6. Sand. e. Fine sand. : FIG: eleé d. do. do.with clay. @. Glacial clay. a OOM CEE Fig. 21D. Sketch of outline of sandhills, near Leighton Buzzard, Beds. Crowborough Beacon, in Sussex, only remains as a high hill in consequence of the ironstone in the sands of which the hill is composed, paving the brooks and keeping the water from touching the sand below. Ecclesbourn Glen (Fig. 24) is a good and accessible instance. ‘The pieces of fallen rock pave the channel so as to resist the denuding action of the stream. Watershed. SECTION. FIG: 28 through ALD. f Binonuil curve. / | Hop sil tid FIG: 218 Hie ca th Itt gee at EIN SECTION through EF ATLORDE/ ff GI Ha Ne Binomial curve . Brook. ' ' Brook ena AL vo 4 | 3 | i H : L Brook ! | ! ~~ Brook 1 1 45 120 WO 252 20 Ro 45 jo Ll 45 1 FiC21.D TRE BEATA A B aN 7 SOLS 4 Sand Hilt. + /( Lower Greensand.) we Sa ee — ee Kimmeridge Clay == fag A.TYLOR. DEL. Fig. 23, p. 456, isa section through the waterfall Fig. 24 showing the bed of clay underneath the hard rock: water oozing through the joints of the stone passes between the stone Aand the clay B. As the edge of clay at C is washed down, the stone at A falls there. This is the same case as Niagara, where a thick rock breaks vertically through the water from the lake above, passing below the Niagara rock and removing the base of shale. (25) Fig. 244 gives a view of the Chalk hills near Folkestone, where small lateral valleys have been cut out by rivers flowing out of springs in the pluvial period. They are almost dry now, but were once of immense volume. Law of Waterfalls. ‘ 455 Fig. 24 represents the valley of Ecclesbourn, near Hastings, if the pluvial period. The model of Brading Gorge, in the Isle of Wight, shows that the rainfall, thrown off the lofty Chalk and Upper Greensand hills near Shanklin has, in comparatively recent times, cut a passage through the lower range of Chalk and Upper Greensand hills near Brading. The higher elevation of the bed A (Fig. 25), caused by subterranean movement, is the cause of the direction of this rainfall collected into brooks from Ventnor to Brading. The same bed of Lower Greensand, at Shanklin, is 250 ft. above the sea; while near the Gorge of Brading it is at the level of the sea, giving a fall of 40 ft. inthe mile. The level of the chalk is 500 ft. at St. Boniface’s Down, near Bonchurch, and 300 ft. 456 Coombes excavated by Springs. on the chalk down above West Knighton. It is the coincidence of highest slope directing the water, and a low point in the escarpment or range of unstable beds that can be bored or undermined, owing to favourable transverse flexures bringing up the beds at a convenient level, that determines the position of a gorge.® (See page 457, Fig. 25.) Lolkestone ‘in Pluvial period alkered from a Drawing by FIG: 24A. F. RUTLEY. YS Zk a I Ue
  • WEAR BRALINE ——— Hgts de So eR 8 = Aneent i ahe= WW ao e < NN > Sy i is SS WZ ; a = SUNS EG Te very beautiful drawing painted on the spot, by Arthur Severn, at Constantine, in Algeria. I have found a case in which both underground and overground channels remain, in Ystrad Vellte, in South Wales, near Hirwain. The rock is hard limestone, at the mouth of the cave 55 ft. high. On one occasion in the last two hundred years, there was such a flood that the water rose forty-five FIG:2 7. Garge through DE. Chilihilh Dey farmed. FORECROUND WEALDEN BEDS H AND K A.SEVERN DEL s feet up to the top. I have measured drawings of this interesting spot. The cave is one-third of a mile long. In a wet period, like the gravel or pluvial, the upper and lower channels would be used simultaneously. T consider the steepness of the Cheddar Cliffs, and of the limestone gorge, at * See Fig. 35, page 473, where the double set of flexures on the escarpment of the Surrey Hills are described. . 458 Drawing by Arthur Severn, Clifton, through which the Avon passes, is due to the ground having been perforated.® I believe the steepness of the cliff at Box Hill, 75° at the south-east ~ corner, is due to the ancient cave, through which the waves passed, originally being at that point ; and that the under-cutting below enabled the chalk cliff to be nearly as steep as at the sea shores, where the water has undercut, as at Culver Cliffs. This is the case of the nearly vertical cliffs at Cheddar ; for when there was a tunnel, the roof falling in, left a vertical cliff above. There must have been very high ground at Bristol. i Ina period with twenty to fifty times as much rain as at present, these underground passages for rivers would be formed with great facility, there being the assistance of 80 or 100 ft. head of water. We have the evidence from the pipes in the chalk, that this water was heavily charged with carbonic acid gas, although we do not know the source. Under such circumstances the Gorge of Brading would be easily made. At West Knighton, two miles W. from Brading, an opening was being formed when the wet period ceased. You can see on the model the deep grooves being cut out by water. Every coombe is due to springs, and long escarpments, such as the Surrey Hills, or the escarpment of the Lias and Oolite, called the Cotteswold Hills, were being prepared for boring in this manner. Figs. 27 and 28 represent what has happened at Brading. Fig. 29A represents a limestone valley, Dove Dale, where the sides are very steep, owing to the greater stability of the carboniferous limestone than the sands (Fig. 29). The undercutting, by the river, nearly occupying the position ofan old underground channel, is clearlyshown. If Mr. Jukes had considered the method I have shown of the formation of gorges, when describing the Irish rivers Shannon and Blackwater, &c., I think he could have explained the causes of FIG:28 Gorge ‘through Chalk hills DE, formed. = FOREGROUND WEALDEN BEDS H ANG KF A, SEVERN. DEL, their present direction more satisfactorily. His paper on rivers laid the founda- tion for the subsequent papers on the same subject by Prof. Ramsay. The forms of valleys, lakes, and waterfalls affect and are affected by this special degree of motion of the water or ice, which modifies their forms, or causes what in mechanics is called instability. Indeed, valleys and escarpments with their springs, are integral parts of every complete river system. The earthand the water flowing over it must be considered at the same time, so intimately are they connected. They are related almost like the veins to the blood, and the sap vessels to the sap in a tree. 5 See note, page 472. Cause of Horse-shoe Bends in Rivers ts unequal Rainfall. 459 I hope to show that rivers and lakes now occupy valleys and hollows formed. when the physical and atmospheric conditions of our island were very different from those it now presents. Ancient rivers may have had many hundred times as much destructive effect on the surface of the earth, for erosive force increases in the fourth power of the velocity, and may have eroded the surface of the earth as much in former times. in one year as they now do in 1,000, in cases where rocks were made to slide on clay by excessive supply of percolated water. I must ask you to assume what I have demonstrated many years since in another place, that all valleys, without exception, are enormously large, com- pared with the present rivers and brooks occupying them, and that the present. size is the proof of the former rainfall or snowfall. This fact is visible to every- one in their walks or journeys, and the only inference from it is, that in the: period just before man appeared, when the valleys were enlarged to their present. size, the rainfall or snowfall was at least fifteen times as much as at present. Figure 31 shows that rivers enlarge their channel on one side, the concave, and silt up on the convex side. The consequence of unequal rainfall is this movement of river channels in horse-shoe bends. : Some of these valleys were excavated in a very cold or glacial period by the action of enormous quantities of ice. Other valleys were excavated or en- larged by the action of ancient enormous rivers and springs of great power, in what I have termed the pluvial period. Fig. 31 shows a case of a river changing its course in a flood 150 feet. (27) FIG:3]: RUTMOO RIVER- B02 Movenent of river chamnd in one flood Width, AA, 1450 feet : From SieP. Cautley paye 22 1850 = =~ yn na He nd REA, Ue " 3 TLL Ly. Wir L Uy Te Figure 25 is a specimen of the action of springs, and represents the hills near Folkestone : at the present time most of these springs are very small. These ancient streams were fed all over the globe by such rains as fall only in few places at the present time. In the Nile there are no tributaries at pre- sent falling into it for 1,000 miles from the delta, but there are dry valleys opening into the great Nile valley of enormous size, so that 300 inches of rain falling in the now dry climate of Egypt, would be carried away by the river, not without inconvenience, but without much difficulty. The Cyrena fluvialts, now living in the Nile, was alse found 120 feet above the present water level, at Silsilis, by A. Harris, showing that in floods in the pluvial period (which I consider that of man) the whole valley of the Nile, wide as it is, must have been charged with water up to 120 feet above the present flood level. I think 300 inches of rain is the smallest quantity that could have fallen in a. year, when the great masses of the Thames Valley gravels were deposited on round where the present streams cannot move the old deposits. That the present rainfall has not sufficient force to excavate new brooks and rivers in the London or any ordinary flat or alluvial district, I think will be ad- mitted by all. There is no case of this kind known since the historical period, in the Thames Valley. If I can prove the truth of the new law,* that with twenty-seven times the * T first reduced this law to an equation from observation, and illustrated it by a diagram, in 1871. ae === AL EACH A ar eg=CHINE= LY) \ Uy OR HE: iy } Lg oo The permeable strata B, D, and Z, are stable beds formin g pe give the profile of a 1 . The alternations of wall and slo ked as in hard rock in a less exposed situation. pes of less permeable strata. th more water than at present. fl BU WN Y, i ly ap Hf NWA Neal fh Nile ue 3 | = oO oF nunuw oo an Sy 8 a ae SE.8 aa 8 2SQa SOD aoe AAG} ie wuts O an ane <2 8 23? to Se 23.8 wid ogg o,9o Ceney igo OR u sag Oe on S we sas Son Oo A aig ~ Sade SO.8 POS ns oo -> Ons Gres nosies) ears Rous fetes) ado 20 Fic. 29A. View of Dove Dale, Derbyshire. Showing undercutting in limestone rock at @, ¢, and wz, by atmo: spheric action, and at e, by indirect action of water. ‘The undercutting shows in hard rock the varying stability 0 the limestone, or the action of springs at those points. The same form or profile of alternating vertical wall and slop« at a lower angle is well marked in Fig. 294. This is the same profile asa Gothic buttress, adapted for stability under atmospheric which is a shape wel influences, 462 Wealden Gorges due lo two Opposite Series of IMexures. rain, the brooks would travel with thrice the velocity they have at present, and if glaciers twenty-seven times higher would slide with a threefold velocity, then we have a cause which can sufficiently explain the erosions or lowerings ‘by denudation during the glacial and pluvial periods, The rounded London Clay hills in many places are curved like Fig. 19. The deposits of the large brick earth and gravel beds are conspicuous in the valleys of the rivers of the London basin, and the tracks of ancient rivers (as at Crayford) in the eroded surface of the chalk, now filled up with gravel and brick earth, may be seen in the excavations for brick earth. There are no beds of this kind now forming, and this shows that the present is not a guide to the past in the science of geology in many cases. _ It is from these superficial accumulations of the pluvial period that the ‘brick earth is derived, from which the building materials of this city are almost entirely derived, and the quantity of brick earth is a kind of measure of the intensity of the ancient rains. Philosophers and writers of books on philosophical geology are always spe- ‘culating about what are called remarkable phenomena, and very much neglect what occurs every day, and can be seen every hour. We ought to look at the low ground, as well as at the mountains. Being, as Mr. Pattison observed in a paper read at the Victoria Institute, March 1, 1875, more of an observer than a theorist, I would rather speak to you if I can, to-night, about what is the action of rivers and springs in places you know well. The Fig. 25, page 457, is a type of the north and south flexures of the Weald. ‘The gradient being so rapid north and south, the series of beds, Weald clay, Lower Greensand, galt, Upper Greensand, chalk, marl and chalk, crop out within two or three miles or less in the case of Guildford. In walking north and south you walk at right angles to the strike of the principal flexures. On the other hand, the east and west flexures are slight and always along the principal strike, so that you may walk along the out-crops of the same bed hundreds of miles. That is, you may walk along ¢he strike of the north and south great Wealden flexures, which is of course E. and W., or in the direc- tion of tke dip in the small E. and W. flexures. The Wealden physical features are so difficult to describe because there are these opposite sets of binomial flexures, and what is strike to one set of flexures is dip to the other. There were evidently forces acting at right angles to each other when the Wealden was lifted up, each foot of surface having a simultaneous opposite flexure impressed on it, causing a double curve, affecting the whole depth of strata, Fig. 35 represents the east and west flexures in the galt and Weald clay beds in the north escarpment of the Weald, which facilitated the original formation of the gorges through which the rivers run. This is explained in a note page 473. Avriver directed north against G would be repulsed by the clay, and have to flow east or west to B2 or B3 to make a gorge. Clay is very stable here. There are aseries of flexures east and west along the north escarpment of these Surrey hills, about 20 ft. per mile from Hildenborough to Maidstone, and Io ft. per mile from Hildenborough to Dorking. The strata are only gently lifted and depressed in E. and W. direction 20 ft. to 10 ft. in a mile, while the great north and south flexures are near the gorges at gradients from 250 ft. to 1,000 ft. ina mile. It is this system of double flexures, one set in the medial series at nearly right angles Pluvial Period due to Sun’s Influence. 463 to the other two sets, ot marginal series of bends, that determines the denudations of the Wealden. I showed in 1862 (Quarterly Journal Geological Society) that the medial beds of Hastings sand thinned out N.E. and S.W. in a horizontal line passing from several hundred feet in thickness at Castle-hill, Hastings to 3 or 4 ft. 7 miles to the N.E. and S.W., and having a series of flexures in that direction. It is only where a river carrying a large body of water attacked the point weakened and prepared by springs and underground river channels, that such an opening as the Gorge of Bradin& could be made. The ground at Sandown was formerly the highest on the island ; now it is the lowest, owing to the instability of the upper beds of Lower Greensand reposing on the weald of clay at the level of the sea. This is the cause of the gorges of the Weald at Guildford. The Weald clay at Pease Marsh comes up there about 100 ft. above the level of the sea ; and this has been the determining cause of the perforation at Guild- ford by the Wey, theWeald clay being 600 feet under Guildford. At Bury Hill the Weald clay is 250 feet high, and thus directed the Mole against Box Hill, where the Weald clay is 700 ft. under Box Hill. Then at Hildenboro, at the mouth of the Sevenoaks tunnel, the Weald clay was a solid mass 400 feet high, and protected Sevenoaks from the attack of the Medway. The gradient or slope of the Medway was too small for the river to bore at Hildenborough, and the river, therefore, changed its course at nearly a right angle towards Maidstone, and there resumed its original direction. Otherwise the Medway would have joined the Darenth if it could have succeeded in perforating a gorge at Sevenoaks. At Merstham there was an attempt by tributaries of the Mole to get through the chalk and join the Wandle, which was not successful. Thus one river had to pass to Maidstone, 20 miles distant, where the Weald clay was 400 feet less high in the direction of the escarpment of the Surrey Hills, Other rivers fell from 250 to 1,000 feet per mile, between Pease Marsh and Guildford, between Bury Hill and Box Hill, between Maidstone and Burham, and between Sandown and Brading, when these four gorges were formed. The high dome or elevated land at Crow- borough determined one set of rivers, and another dome or elevated mass, called Hind Head Hill, near Haslemere, was the source of another set of three rivers going also in different directions, which have opened out gorges through the escarpment of the chalk similar to that at Brading. It was the fact of these two points being elevated higher than any other that started the Wealden rivers from them, just as the highly elevated ground in the Alps started the Rhine and other great rivers; and other and less elevated ground, like that near Donauessingen, started the Danube, and sent off smaller rivers to oppose the Rhine and keep it off Donauessingen. No doubt the Rhine now follows a course worked out forit by an underground river passing through the Devonian rocks between Bingen and Bonn. I find from Mr. F. Tuckett that the real springs of the Rhine are twice as high as those of the Danube. If a straight line was drawn to the Delta from the source of the Rhine, it ‘would nearly touch the level of the springs of the Danube. The sketch of the Gorge at Brading may realise what has happened there, and serve as a type of the valley excavations of greater rivers (Figs. 25, 27, 28). PLUVIAL PERIOD DUE TO SUN’S INFLUENCE. I have shown you the effect that great weight of ice sliding or water flowing has upon the velocity of ice and water currents, and that the enormous erosion of the surface of the earth visible in valleys and lake hollows could only have taken place when there were twenty times as much ice and snow as at present. These different atmospheric conditions point to some as yet unknown causes. Such snow and ice could only be formed by great heat in summer and great cold in winter. Some disturbing effect in the atmosphere of the sun could, I think, alone account for the phenomena we obserye, and that must have been of a 464 Lluvial Period due to Sun's Influence. FIG. 32. Sun. A.TYLOR’S ESTIMATE BY NEWTONIAN LAW. N. Wuclis. IN, Diameter 4900'S THES Spp:Ga 5-7, anes EIA D ann — Sk~E. Envelope were nn nee- \ Suns dametr;-- E50, 000 miles. : Suns Specie gravity O-C0L, Pando saat HCO... 0-OOC4 hatio of finvelope to Nueleu 8. BY WEIGHT. BY VOLUME, £10 39 O24, LECO 515 60 periodical character. That is to say, the Earth must have received much less sunshine in winter and much more in summer. I calculate that the specific gravity of the sun is not more than 0:004, instead of 0°2543 as usually stated. If the nucleus of the density of the earth is 5°7, and if this nucleus is one-tenth of the whole diameter, then the density of the gaseous envelope of the sun would be only o-oo001, or about that of hydrogen gas. The weight ofthe sun seems to be enormously exaggerated. I do not find any careful calculation by any writer; and I only work it out as one-sixtieth of the weight that has been attributed to it. Chemical changes in the sun’s envelope might produce great alteration in the sun’s temperature. There is no reason to suppose the heat of the sun should be constant for any long geological period. Also the series of rocks commencing with the Silurian, show evidence in every successive period of difference of conditions of life, and this evidence points to constant change in the quantity of heat and light emitted by the sun, and great alteration ofatmospheric conditions. Particular instances are the abundance of carbonic acid gas in the air during the carboniferous period, and again in the quaternary period. This is shown by Mr. Prestwich’s paper, * investigating the cause of the eroded surface of the chalk, and is in one case proved by the rapid formation of coal, and in the other by the occurrence of deep pipes in the chalk, which appear to have been excavated by water containing a large quantity of carbonic acid gas. The models and diagrams, however carefully executed, convey a very poor idea of real geological phenomena. Lectures are of very little use, except supplemented by observation in the field. The model of the form of the surface in the chalk at Brading gives an idea of the excavation of the gorge in the chalk * Prestwich’s Quart. Jour., p. 64, 1855. German Ocean lately Dry Land. 468 between Dover and Calais, much as the drawing of the rivulet in Ecclesbourn Glen gives an idea of Niagara Falls. From close examination of small valleys we may learn a great deal about larger valleys. The abstraction of water to make ice for collection on the land in the glacial period must have dried the channels and coasts of England to what is now the hundred fathom line. I have many years since surveyed from Shakspeare’s Cliff, the Channel—which I believe was once a watershed, bored and pierced by many rivers and brooks in a cold and after- wards very wet period: I can speak particularly of the effect of the landscape from Dover and from Cape Blancnez upon my own mind, and of the stillness of those treeless chalk downs— not plains of chalk, but a series of headlands and large coombes rising to 600 or 700 feet above the sea. In this watershed, now drowned, were once the sources of two large rivers or glaciers; one passing round the east coast of England and receiving the Thames, Somme,* Rhine, Maes, Scheldt, Humber, Forth, &c. as tributaries, and passing to the Hebrides ; the other river or glacier at one time passing along the south coast of England, and receiving the Seine and all the small streams on the French north and English south coasts, having great waterfalls at the places where are now the races of Portland and the Channel Islands. This stream of water or ice met the perhaps frozen Atlantic near the Scilly Islands. It requires very little imagination when on these wonderful chalk cliffs to realise the extensive changes that must have occurred in the glacial period, when the German Ocean was obliterated, and when there was dry land to enable the Spanish plants to pass over to Ireland, the plants of Brittany and the Channel Islands to the south-west of England, the plants and land mollusca of Nor- mandy to the south-east of England. The longer connection by land of Guernsey and Belgium with the east of England enabled the flora and fauna of those countries to extend nearly all over England and Wales; while two-thirds of the Belgian reptiles got located in England, and three or four species crossed over to Ireland on dry ground, over what is now the Irish Sea. Then the Scandinavian plants crossed to Scotland and Wales, and a few to Devonshire, remaining now in groups on the high land of Wales and Scotland. Anyone familiar with the existing glaciers of Switzerland and Norway, and with the lakes eroded by ice action, or with the remains of ancient glaciers in Snowdonia, and with the glacier-excavated lakes there, can realise in some measure the effect of the great glacial and pluvial periods, and can understand that it is hopeless toattempt to explain them in a lecture-room. I cannot admit the correctness of the authoritative statements in the ‘‘ Principles of Geology,” that we must not conceive greater forces than are at present in operation, although made by the eminent writer who has lately terminated a long life devoted to the study of geology. The geologists present in this room to-day, however much they might differ on all scientific questions, would all agree that very little is to be learnt in geology or physical geography without personal observation. And my advice to students is, not to rely upon books and lectures, but to use their own eyes in studying the sections and drawings. I have now alluded to some of the points of the theory of uniform motion of rivers and glaciers. I attribute to the effects of gravity in inducing friction of ice upon ice, in lake and other great glaciers, enormous excavations in the ice period. This closed at a date not far from the historical period in some parts of Europe, while in other parts there was at the same time a pluvial period. + * Godwin-Austin, Quart. Jour., 1850-51. + Mr. Croll is quite in error in stating that geologists considered the glacial period occurred amillion years ago: only one geologist and his followers held that opinion. Jukes, for instance, in 1862 considered the glacial period quite recent. Prestwich thought that the quaternary gravels were post-glacial, but he gave no estimate of such a time as Croll indicates, nor did 466 Denudation 1s Instabihty. The quantity of water flowing is an important element in computing the change of surface, whether in a cliff or a waterfall. ‘The stream at Black Gang Chine (page 460) is very small at the present time, but if eight times the quantity of rain fell, and the velocity was doubled, the power of the surface stream would be much increased. This is, however, only one element. The water from each flat watershed descends under ground and escapes in springs, and springs in a wet period have been the great denuding agent. ‘The action of denudation by underground watercourses has never been sufficiently estimated or properly calculated. The contour of surface depends upon the resistance of the strata to the rain- fall. The terrestrial surface of the earth is always a succession of terraces and flats, or rather walls and slopes. This is what we call ‘‘contour.” In some districts, where the walls are very conspicuous, we call the ground terraced. Where the walls are low they often escape observation. Water produces, equally, lofty and nearly vertical walls in some permeable beds, and low surface slopes in other impermeable beds, or it produces a succession of infinitely small walls and slopes, which to the eye appear like a plane or curved surface. These are questions of mechanical stability or instability. (Denudation is Instability. See page 487, Geological Magazine, 1872.) The load, the quantity of water, and the direction of the strata, are elements which affect the coefficient of instability. Spring water is the most destructive agent, as the water flows out of the ground, at times under pressure, underholeing, or undermining the most solid rocks, and letting immense masses of rock and sand fall down from the sides of the valley into the bottom, to be carried away by rivers. Anyone who has seen the slips all along the top out-crops of the impermeable fire-clays in a Welsh valley in the coal measure series, when there is ten inches of rain in a month, will be able to estimate the enormous denudation in the pluvial period (see page 487, Geol. Mag., 1872), when there was 300 inches of rain in England in the low districts, and probably two or three times as much on the mountains. I shall continue these observations at a meeting of the Geologists’ Associa- tion, June 4th next.* any other independent geologist but Lyell hold these opinions. Sir R. Murchison in his address to the Royal Geographical Society in 1863, said almost all geologists were agreed as to man having made his appearance in a very recent and in a glacial period. * Quarterly Journal, 1868, p. 394. Geological Magazine, 1872. figuation to Uniform Motion of Water, 467 APPENDIX. From the equation Q= AV (using Q and g for discharges per second, and A and a for cross sections, and I and z for slopes), and from observation, I have ey g 7 (2), and 2 = jf aes vaa/e ay -(3) Vv Ql Vv Ae i OW AT from which I obtain a new equation to the flow of water in uniform con- strained motion—that is, only when V=v, This is true for any slope with the same material of channel, i OT) RO I Then from (2), when am thena/ L=a/ or ae z Then from (3), when wei ve = io* coe Then by compounding i in the very general case ae water is in Gr(on motion we have the formula It applies to water in oo in Core motion, as in Figs. 6 and 7, page 446. Coefficients have to be used for each different material of channel, which are here omitted. They are found by observation, The effect of motion in diminishing pressure is an important physical cause ; this appears to have been overlooked. I quote some remarks on this subject in relation to the barometer, because they have a general bearing on all physical questions where pressure is modified by motion. From the QUARTERLY JOURNAL OF THE METEOROLOGICAL SOCIETY, for Fanuary, 1875. Mr. A. TyLor said he should like to offer some evidence to prove that the barometer cannot be considered a correct instrument for registering the abso- lute weight of the atmosphere, although it often indicates the relative weight correctly. The absolute pressure on the cistern of the barometer varies much more for horizontal motion of the air than it can for mere change of weight of the atmosphere.* By analogical reasoning from his experiments on the Injector, described page 215, Phil. Mag. September, 1874, he stated that the column of mercury in the barometer shortens for motion instead of lengthening for weight. There isa constant fall in the barometer during the formation of clouds and condensation of vapour into rain in temperate climates, where the rain-making process occurs in the lower strata of the atmosphere. The mixture of dry air and vapour at 40° would cause a change only of 8 parts in a thousand in volume, and yet would cause a considerable lateral and vertical displacement and movement in the atmosphere. The change in absolute weight of the atmo- sphere under these circumstances would be comparatively slight, and would not account for a fall in the barometer of 0°3 in. or 0-4 in., or 3 per cent. (or 30 parts in a thousand), which is frequent in England during the process of rain- * Professor R. Tennant, of Glasgow, informs me he has read a paper recently at the Royal Society of Edinburgh (which will appear in their Transactions), ‘‘ On Meteorology,” containing a view of barometric action. From the abstract sent this appears to be similar to my own. 468 Motion affects Pressure tn Barometer. making. Then, directly the rain has fallen and the air becomes quiescent, the barometer rises again; the influence of motion having ceased equilibrium is nearly restored. In tropical countries, where rain is formed at a high elevation above the ground, the horizontal movements in the upper strata are masked completely by the actual rainfall near the surface, tropical rain making in its fall vertical currents in the direction of the ground, thus causing the barometer to rise because it actually puts an extra line of pressure on the cistern. In the Doldrums, it is well known that the winds meeting near the sea-level con- stantly mix and cause an upward current, accompanied by condensation of vapour. The barometer is therefore always a little under 30 inches, not because the atmosphere is lighter there than elsewhere, but because there is horizontal motion across the column caused by the generation of rain, and motion upwards caused by the expansion of the air vertically. The two different causes produce the same effect in diminishing the actual pressure on the cistern of the barometer. It is possible with a velocity of ten miles an hour, in an artificial current of air or blast in a fan to depress the barometer 0"! inch, independently of any rarefaction or condensation of the air itself. This would cause a fall of 0°5 in. for a current of fifty miles an hour if the barometer fell in like proportion. This rate would accord with that observed in atmospheric eos WATER ENTRANCES _3-STEAM & WATER EX!T storms when the force of the wind is fifty miles per hour. He thought no change of mere weight of atmosphere could cause the barometer to fall 1°693 in. as happened in Guadaloupe in September, 1853; or at Bromley 1’o in. on November 29th, 1874; or 1I‘21 in. at Guildford at the same time. This result or fall, showing great diminution of pressure, was perhaps equally due to sudden condensation of vapour causing local currents, and to the strong winds derived from distant regions causing horizontal motion across the column of air, and reducing pressure on the cistern of the barometer and causing the column to shorten. Then, on the contrary, in London, on December Ist to 14th, 1873, the barometer averaged 30°5 inches, the atmosphere being excessively still, and fog continuous. Directly rain occurred, on the 15th, the barometer fell for motion in the air, In his experiments on the Injector, described page 215, Phil. Mag. 1874, he found that in the body of the Injector there was 121 lbs. of pressure by the gauge, accompanied by rapid motion of the steam, yet, in an adjoining tube, connected with the water tank opening at a right angle into the Injector, there were two inches of vacuum according to a water gauge. The experiment shows that within an inch of distance of a current of steam at 101 lbs. pressure by the gauge, there was actually an open water pipe with a Orbits of Moon ana Earth not Eliipses. | 469 partial vacuum and a slow motion. This shows how much fluid motion in one direction can influence pressure and motion in another. In Fig. 35, the Injector, the friction of the steam against the metal raised the temperature 0°17, and the pressure I Ib. above the pressure in the boiler, and yet made a partial vacuum in an adjoining stratum of fluid, that is, in the water-pipe. This ex- periment is a proof that the barometer cannot give a true indication of weight when there is motion in the atmosphere. The Injector is a case strictly in oint; the currents of steam and water not being separated by any valves, are true types of the contrary currents occupying adjoining strata in the atmosphere. The drawing, Fig. 35, page 468, represents an ordinary injector. About 60 experiments were kindly made for me by James Cudworth, C.E., at Ashford, to determine the state of the relative pressures in the boiler, injector, and water-pipe as soon as the water began to enter the boiler. The currents at different levels and different direction in the atmosphere may affect the barometer much as different currents of steam when the boiler pressure change very rapidly affects the reading of the*barometer. The results of the experi- ments were that in passages connected with each other there was a difference of 100 lbs. in pressure. ‘The direction of motion of the fluid in one part of the apparatus entirely modified pressure in another part. FIG 33 Pid Carve at DD. approxmuaely @ straight Vine Ellipse having its | gretest curvatures as at A.|B. a Linge ¥ bale , SS » aN | XS | ee i we 2 na A.TYLOR, DEL. SUN’S ATTRACTION. The question of the effect of the sun’s heat on different parts of the earth no doubt depends upon the angle at which the ray or heat-vibration from the sun strikes each part of the earth ; but the question of the time and motion of each square foot of the earth’s surface is exposed to the sun’s rays should also be taken intoaccount. We knowthat the effect of the chemicalraysdepends very much upon 470 Observed Orbital Curve. the object being still, and on the duration of the attacking series of chemical rays or vibrations on the exposed surface in the photographic progress. The sensible sun’s heat rays may be in proportion to the time each heat ray or vibra- tion reaches the earth or is in action, as well as to the distance. This may help to explain why the sun’s heat is least when the earth is nearest to the sun, for the velocity of the earth is then greater : the angle of incidence of rays also varying. Fig. 36 represents an ellipse or orbit with the large attractive body at the point F, one of the foci of this ellipse. M’ M” are smaller bodies supposed to be deflected. from the straight line along which they were projected, by the force of the great bodyat F. It will be seen by reference to Fig. 37, that the orbit cannot be a true ellipse which any body M’ or M” will follow. The reason is that the curve in the ellipse is really greatest at A, while it approaches a straight line at D. Attraction from a single force, F to M, could not produce such a result, which would only occur if there were another attracting body of equal size at the other focus F ; that is, an ellipse is a two-centred curve and has none of the properties of the single-centred orbital curve Fig. 37. Orbiad curve not an Elise. fl c, 37. Pp’ 5 p® MtoM tracks of Moor entering Orbit. A.TYLOA. DEL. Fig. 37 is an orbital curve in which the earth moves round the sun supposed to be stationary, or in which the moon moves round the earth when that body is supposed to be stationary for the purpose. The deflection of the small body M, M, M, &c. (from a straight line), projected into the orbit, is in proportion to the weight and nearness of the small attracted body M, M, &c., to the great attracting body at E. The orbital curve at A is greatest because the force E is nearest to that part of the curve, and therefore E deflects M (extending its orbit and continuing it in the track) most from a straight line. In Fig. 37 the attractive force from E is at its mean at C and D, and therefore the curve at those points is at its mean at Cand D. The gradient or slope of the orbital curve is at its minimum at B, because E can deflect the small body M?* least at B from a straight line. The gradient or curve is greatest at A, because the attractive force at E can deflect the small body M the most from the straight line ‘in which a body like the moon or earth was originally projected through space. Movement in Orbit simple Resultant of forces. 471 It would continue moving in a straight line except when deflected by attraction, and therefore the curve of deflection, or orbital curve, may be considered as the resultant of the two forces. The orbital curve is really to be treated as a case under Law 3, Cor. 1and 2, B. i. Principia, where the law of the parallelogram of forces is stated. As the orbital curve is not an ellipse, Prop. xvii. prob. ix. B. i. Principia does not apply. That proposition only applies to conic sections. The shape of Fig. 37 proves the orbit of the earth or moon cannot be a conic section. Why the orbit of the earth was ever treated as a conic section is difficult to. understand. By calculating the gradients of the orbit—that is, the curve at different points-—I find the curve is much more egg-shaped than elliptical. In all the drawings of the orbit of the moon, where the earth is considered stationary, from the times of Kepler to Procter, I find the orbit drawn as an ellipse, with the curve at B Apogee and A Perigee—the same gradient, if I may use that term. I find, however, that at A Perigee on the 22nd November, 1874, the gradient of the curve was 0°01185 of a foot in a mile, while at B Apogee on the oth, the gradient was only 0:01047 of a foot in a mile. On the 15th, when the moon was near the mean distance for the month, D the gradient was intermediate, or 001082 feet in a mile. In an ellipse at mean distance C or D the curve would be almost imperceptible, and also would be of equal gradient at B Apogee and A Perigee. The same genera] remarks apply to the orbit of the earth round the sun. J have shown the point P on the 27th of November, 1874, nearer the earth, Fig. 37, than on the Ist by a considerable distance. After the whole lunation on the 27th November, when the moon is in the same position as to angle as that which is occupied on the 1st November, as regards the earth, the moon is less distant. This is indicated in Fig. 37 reduced from large drawing in which I calculated the distance of the moon for each day. Fig. 37 is a complicated curve, not a conic section; I haye called this the orbitak curve, the velocity and gradient decreasing from A to B through C and increasing from D to A through C in a simple ratio. NOTES. 1 Note to page 439.—Ice acts as a colloid in promoting the passage of vapour or of water into the interstices of cells, and thus produces the cold necessary for regelation, by evaporation of water. Directly the spaces are filled the contrary action ensues, and that is the reason why there is no regelation when there is no superfluous water to melt the ice in contact with it, or too much water. With ice (if possible) frozen of the. specific gravity of water in an hydraulic press, regelation would not occur, as there would be no air cells orcolloidal ice. As wet ice regelates and freezes to flannel, the explanation of regelation cannot be that it depends on cohesion or attraction of surfaces, except so far as these affect evaporation and condensation of vapour. 3 Note to page 442.— Fact mentioned by James Giekie, Ice Age, 1875, Note to Fig. 9, page 447.— B Channel......... A BC CD DE Mean velocity nearly Discharge ...... 0203 0°307 0618 1°236 equal in the four chan- Welocityarse-na- 1'278* E259 1°325 1348 nels, notwithstanding Slopemernsessr 0°00824. 0°049 000208 00015 difference of slope. The observations were made by Darcy and Bazin, 1868, without any view to this theory. Recherches Hydrauliques, Paris. Note to Fig. 10, page 448.—E calculated in 1853 (Phil. Mag. p. 264) that the solid matter in suspension in Mississippi water indicated a denudation of the whole surface of 1,240,000 square miles (the area drained by that river), of 1 foot in 9,000 years. By taking into consideration the siliceous matter carried beyond 472 Denudation of Earth Measured by Improved Method. the Delta, which I omitted, and estimating the proportion of quartz rock to clay slate as 2 to 1, in the district under denudation, I now calculate the average rate of denudation in the Mississippi area (which is supposed to be the average of the world) at t foot in 2,000 years, of which 8 inches is siliceous matter, and the other silex and clay in the proportion they are found in clay slate. The usual proportion of silica and alumina in the solid matter suspended in river water is that in clay slate, according to Bischoff: that is, silica 651 and alumina 16°38 per cent. in clay slate. In the Rhine water Bischoff found the sediment, or matter in suspension, composed of 63°77 silica and 15°54 alumina. On the contrary, in the Permian beds he found silica 97 and alumina 2 per cent. The proportion in the rocks of the globe of silica and alumina gives a means of calculating the rate at which the whole surface of the earth is lowered. The wetted perimeter at Fort St. Philip, Mississippi, is 2,576 feet. If the sand on the river bettem and channel moves out to sea 1 foot deep at ro feet per minute, twice as much material will be-con- weyed beyond the mouth of the river along the bottom as is carried away in suspension. Colonel Tremenheere, in 1866, made a series of observations on the movement of water coast-ways on the coast of India. He found a con- stant current in one direction at a mile an hour, taking floats from the Indus’ mouth right into the harbour of Kurrachee. Mr. Croll has entirely omitted from his calculations the enormcus mass of sand pushed out or carried out to sea by rivers, in his late estimate of denudation in climate and time. He has also mistaken the figures, I printed first, of the coast line of continents, for the coast line of the whole world. In Phil. Mag. 1853, I gave Fig. 3, page 263, the proportion of the coast line of the whole world, and made an estimate of the denudation by the sea, taking the coast line of islands as twice as much as continents. Mr. Croll has varied my figures, and arrived at a conclusion that no one could admit as to denudation. I consider that after a long denudation the coast line would be very much lengthened, and the surface of the land would be as much raised by blown sand and coral banks as it was lowered by other actions. * Note to pages 442 and 449.—Dubuat has been misunderstood on this subject by Mr. Croil. Dubuat limited his remarks on the relation of motion to slope to the case of alittle canal, and never intended his remarks to apply to the relative motion and slope of the ocean. Mr. Croll’s argument on this point with Dr. Carpenter is unfortunately based upon an incorrect reading of Dubuat, and cannot be maintained. 5 Note to page 456.—The Niagara limestone is 80 feet thick, lying on the Niagara shale, also 80 feet thick, according to Dana, where the Niagara waterfall is 60 feet high. The covering of the shale by falling blocks of limestone, is not noticed by him, although it must be, I should think, an important feature. 6 Note to page 457.—The gradient from the surface of the Weald clay once upon Crowborough Beacon (then 1, 700 feet high), in the direction of Sevenoaks Weald, near Hildenborough (400 feet high), close to the south end of the Sevenoaks tunnel, was a comparatively flat surface, about 80 feet per mile ; that is, the fall, from 1,700 feet to 400, or 1,300 feet in 17 miles, 1s 80 feet per mile ; while in the gorge at Dorking the Weald clay falls 800 feet in a mile. In one case there was a watershed and a small denudation, in the others a river and great removals, owing to the difference in dip favouring denudation. 7 Note to Fig. 35, page 462.—This wood-cut, Fig 35, and accompanying expla- nation, was set up in type by Mr. Anstin, of Hertford, in 1872 forthe Geological Magazine. My paper on denudation, with allusion to the Weald, was being published, but the end of that paper was cut off for want of space, including the illustration. I reprint this on page 473 from the proof of 1872 without alteration. Formation of Wealden Gorges. 473 Fig. 34 is asection of ariver perforating an escarpment from north to south. The dip may either be north or south, without altering the form of the escarp- ment streams S! to SY! flowing from E. to W. or W. to E. The Wealden rivers flow with the dip ; the Avon, at Clifton, flows against. The strike, here represented east to west, appears to be important, as, whatever the dip may be, the river enters the escarpment at a right angle. It can make most pro- gress in denudation when it strikes the strata directly, and not obliquely. bins FIG. 34. The Streams S! to Sy; are shown entering the side river, or banks, Vi to VY! at an acute angle, and these enter the mainstream, near R! also at an acute angle. Ina paper sent to the Institute of Civil Engineers, February 1872, the author has discussed the question of river junctions. The stratum shown south of the streams V! to V"Y is intended for chalk, and is shaded so as to show the bigher elevation of the source of the streams, S' to SY! , in consequence of the greater stability of the chalk, than those flowing from G, the Gault clay con- taining those streams. It will be observed that the stream S* flows nearly north, then west, and then south. The streams flowing off the Wealden Escarpments take such a course that they, after a few miles, flow in an opposite direction to that they first followed. Fig. 35 represents this general fact. The height of the main stream at V1 depends upon the distance and relative levels of the Watersheds, and of the point it discharges at into the sea or great river. The longitudinal flexures of the pervious and impervious beds, and the general. direction of the side streams also, upon the quantity of water flowing, deter- mine the exact position of the Weald and other rivers. The course of the side streams is determined often by flexures of the strata and Watersheds, so that it is a complicated problem, but not an impossible one, to find the theoretical course of a river under certain known conditions. Wes7 This diagram shows the effect of transverse flexures on the Weald clay, or Wealden valley, combined with similar flexures in the Lower Greensand, in determining the particular points of the Wealden escarpments to be perforated by the Wealden rivers. The rivers Wey, Mole, and Medway R!, R!4 RI, flow at the bottom of the traverse binomial curves B!, B!, BUI, The great flexure near Holdenborough, for instance, raises the Weald clay to a much greater elevation there than at a point at Dorking. 474 List of Scientific Papers. Io. II. 12. 13. EUS Ola SGIUBININGONG J2AUABIES LEC ale I WILOUR, JESGaSe And Short Reference to their Contents. . On the Occurrence of productive Iron Ore in the Eocene Formations of Hampshire. Quarterly Journal Geological Society, vol. vi. page 133, 1850. . Full Abstract “On Changes of the Sea Level, and on Denudation.” Contains method of computing present rate of denudation of the land from present fluvial and marine action, by estimate of material now carried out to sea by rivers and removed from cliffs by the sea. That there were larger rivers and more rainfall and denudation in former periods. Philosophical Magazine, pages 258—274, April, 1853. Taylor & Francis, London. . Short Abstract of above. Vol. ix. page 47, in Quarterly Journal Geological Society, 1853. . Full Abstract ditto. Silliman’s Journal, vol. xviii., pages 21 and 210. New Haven, U.S., 1854. . Ditto, ditto. Canadian Geological Journal, 1854. . Report on General Metal Work in Paris Universal Exhibition, 1857. Jurors’ Reports. Part I., 101 pages. Eyre and Spottiswoode. . Part II., ditto, ditto, 48 pages. Supplemental Report, General Metal Work. . Part III., ditto, ditto, 17 pages. ‘‘The Education of Workmen and the Improvement of their Social Position.” This work contains a statistical account of the number of manufacturers in business at a specified time, distinguishing those who have commenced life as workmen from those who have commenced with small or large capital. The accounts show that the proportion of existing manufacturers is in the same proportion as the same classes in the whole population. . Articles on Metal Work, Ure’s Dictionary, R. Hunt, F.R.S., Editor’s Edition 1860. Founding, &c., &c., Longman. . On the Footprints of an Iguanodon, lately found at Hastings, and its Position in the Wealden. Contained new view of the horizontal thinning out of the Hastings sand series, on each side of Hastings, and of the relative position of the Weald clay between Pevensey and Eastbourne. Quarterly Journal, Geological Society, page 247, 1862. Rolling and Casting of Metals, 8 pages, 4to. Contains comparative view of regelation of ice and of welding metals, both processes being as dependent upon the colloidal structure of the material. Practical Mechanic’s Journal. Record of the Great Exhibition of 1862. Edited by R. Mallet, F.R.S. Report on Class XX XI., Metal Work. Part I., 13 pages, 1862 International Exhibition Report. Bell and Daldy, 1862. Part II. ditto, 37 pages, ditto, ditto. Part II. Education and Manufactures, 2nd edition. Reprint from Jury Report. Scientific and Art Education in relation to Progress in Manu- factures. Education in England. Longman, 1863. This was one of those works on education selected for examination and used by the Lord 14. 16. 17. 18. ISA. 19. 20. 21. 22. 22 List of Scientific Papers. 475 Advocate during the preparation of the Scotch Education Act, which passed Parliament in 1872-3. The Lord Advocate used the argument in page 36, 2nd edition, 1863, in replying to the objection that illiterate men were not fit to choose school boards. On page 36 it is shown that electors, (among whom are many uneducated) choose members of Parliament—that is, the less educated classes select the more educated men. Also, that parents are more fit to choose proper persons to manage schools than the rich educationists, who subscribe to schools to get their own particular views on certain subjects thrust on to the mass of the people. Jury Report translated into Swedish, by Dr. Andreas Grill, President of Board of Ironmasters, Sweden, 1863. . ‘Industrie und Schule.” Mittheilungen aus England, von Alfred Tylor, auf Veranlassung der Ké6nigl. Wurtemburgsche Centralstelle von Gewerbe und Handel. President, Dr. von Steinbeis, deutsch bearbitet von Dr. Bernhard v. Gugler. Stuttgart, 1865. On the Discovery of supposed Human Remains in the Tool-bearing Drift of Moulin, Quignon. Anthropological Review, 1863, pages 166—169. The authenticity of this specimen was doubted, and the suggestion made, page 168, turned out to be correct, that the human jaw had been removed from an old Frankish cemetery and buried in the ground by the workmen. On the Interval of Time which has passed between the formation of the Upper and Lower Valley-Gravels of England and France. Vol. xxii. pages 463—468, Abstract Quarterly Journal Geological Society, 1866. This paper contains the view that what were termed High and Low Valley- Gravels were of one age, and close to the historical period. : On the Amiens Gravel (Abstract, page 1) and Paper, pages 103—125, vol. xxiv. Quarterly Journal Geological Society, 1868. Ditto, Geological Magazine, December, 1867. This paper contains the first suggestion of Pluvial period, page 105. Das Amiens, Geroll aus Alfred Tylor, Gelesen den 8th November, 1867. Neues Jahrbuch, vol. xviii. pages 129—137, 1868. Leonhart & Geinitz, Stuttgart. On Amiens Gravel, The American Journal of Science and Art, vol. xlvi. pages 302—327, New Haven, U.S., 1868. Dana, Editor. On the Quaternary Gravels of England (Abstract). Vol. xxiy. page 455, Quarterly Journal Geological Society, 1868. On the Quaternary Gravels of England. Vol. xxv. pages 57—100, Quarterly Journal Geological Society, 1869. This paper contains, page 63, calculation of volume of flood in Gravel period one hundred and twenty- five times that at present in thesame valley, and the calculation that rivers were twenty times (or more) larger than at present, page 59. Discovery of a Pleistocene Fresh-water Deposit, with Shells, at Highbury New Park, near Stoke Newington. Geological Magazine, 1868, vol. i. page 391. The flint implement engraved by Mr. Evans, Ancient Im- plements, page 525, was found by me among loose materials in this pit, probably brought with chalk and sand from another part of the Thames Valley. I showed this specimen to Mr. S. Skertchley, and other persons at different times, believing it to be a remarkable fractured flint. Mr. Evans visited the pit afterwards, found the flint where I had been working for shells, and at once identified it as a real flint implement. Very few instances are known of the occurrence of flint implements in the Thames Valley, where it is expected they would be most abundant. 476 List of Scientijc Papers. 24. On the Formation of Deltas, and on the Evidence and Cause of Great Changes of Sea-Level during the Glacial Period (Abstract). Vol. xxv. pages 7—12, Quarterly Journal Geological Society (read November 11, 1868), 1869. This abstract contains, page 9, suggested rainfall 300 inches in Gravel period ; the law of parabolic river curves ; the proof of ocean level being lowered 600 feet in Glacial period, by removal of water to form ice on the land; binomial curve of denudation ; sections in the Modern Delta of Venice, &c. 2s. On the Formation of Deltas and on the Evidence and Cause of Great Changes in the Sea Level during the Glacial Period, with Appendix. Vol. ix. pages 392 to 399, and 485 to 500, Geological Magazine, 1872. This is the paper printed as read at the Geological Society’s meeting, Novem- ber 11, 1868, with an Appendix bringing up the subject to 1872. 25a. Drawings for Improved Ventilation of Mines, Measuring Apparatus, and Laws regulating Flow of Air and Water, 1870 and 1871. 26. On Tides and Waves (Deflective Theory). Pages 204—219, Philosophical Magazine. ‘Taylor and Francis, London, 1874. 27. Remarks on the Effect of Motion in diminishing Pressure, illustrated by the fall in the barometer for motion in the atmosphere, whether caused by motion of air in storms, or by condensation of vapour causing motion in atmosphere during rain-making. Pages 279, 280, Quarterly Journal Meteorological Society, January, 1875. Williams and Strahan, London, 1875. 28. Lecture at London Institution, March 11, 1875. Lecture Supplement to Journal of London Institution, No. 26, pages 27—48, 1875. 29. Ditto, ditto, Reprinted with Additions, September 1. Supplement, Geological Magazine. Triibner. 30. Lecture on Hill and Valley Formation and Laws of Denudation and Rivers, at Geological Association University College, London, June 4th, 1875. ERRATA. Page 436, line 7, for page 26 read page 456. >», 436, 4, 27, for page 32 read pages 462 and 473. 3, 439, foot-note, for page 40 read page 471. » 443, >, 27, for Cauttley vead Cautley. »» 445, for Section at ‘‘ Horwain” read ‘* Hirwain.” », 447, foot-note, fox to page 39 read on page 471. >> 447, line 7, for page 26 vead page 467. A a 5p, CM on Gy JOF = Ted. », 448, at foot, for see page 39 read see page 471. NoTE.—Owing to the alteration of the pagination in reprinting, to correspond with that of the GEOLOGICAL MAGAZINE, some references to the foot-notes have not been altered. All the foot-notes are, however, given at end of Lecture.—A. T. UNWIN BROTHERS, PRINTERS, LONDON AND CHILWORTH. THE GEOLOGICAL MAGAZINE. NEW SERIES. DECADE II. VOL. II. No. X—OCTOBER, 1875. ORIGINAL ARTICLIES. ‘ Se ee I.—On THE Grotocy or CenTRAL SumaTra.? By R. D, M. Verperx, Superintendent of the Geological Survey of Sumatra. HE fossils, which will be described hereafter by Dr. Ginther, F.R.S., Prof. T. Rupert Jones, F.R.S., H. Woodward, F.R.S., and H. B. Brady, F.R.S., were found in the years 1878 and 1874, partly in rocks of the “ Padangsche Bovenlanden” (Highlands of Padang), Government of the West Coast of Sumatra, and partly in marls and limestones of the Island of Nias. In order to show the position of the fossiliferous rocks to each other, and to the plutonic and volcanic rocks which accompany them, I offer the following brief sketch of the geology of some parts of Su- matra, as far as it is known from the investigations of our Survey. I.—Highlands of Padang (Government of the West Coast of Su- matra). See Map, Fig. 1, and Section, Fig. 2. Fic. I. Mar or a Portion oF CENTRAL SUMATRA. 0° ses” Lar N | Tm Seale 1: 1,400,000. Degrees of the Equator. 1 This Memoir on the Geology of a part of Sumatra, including notes on Borneo and Java, by Herr R. D. M. Verserx, Superintendent of the Geological Survey of Sumatra, is introductory to a series of paleontological papers, descriptive of Fossils from the West Coast of Sumatra, to be published with Illustrations, in the Gzo- LocicaL Macazinez, by the authority and with the assistance of the Dutch-Indian Goyernment.— Editor. DECADE I1.—YOL, II.—NO. X. 3l 478 R. D. Verbeek—Geology of Sumatra. 1. The oldest rocks of this part of Sumatra are granites, granite- syenites, and syenites, in several modifications. There are granites which contain only felspar, quartz, and mica; but a great part of them contain also amphibole. The syenites contain, beside orthoclase and amphibole, almost always quartz and some mica; but the granites have more quartz than the syenites. A great part of the rocks of this group may be best called “syenite-granite,” or ‘‘granite- syenite,” as they stand in composition between granite and syenite. There seems to be no difference in the age of these rocks, as there are syenites which regularly pass into granites. The felspar of the gran- ites and syenites is partly orthoclase, partly plagioclase, which shows its triclinic nature by the fine varicolored laminated structure, when examined under the microscope with polarized light. The quartz contains always a great number of “ fluid-cavities.” 2. Next in order follow sedimentary rocks, which are probably of either Carboniferous or Permian age, as they contain Fusuline, which are only met with in rocks belonging to the Carboniferous and Per- mian periods. Both Professor T. Rupert Jones and Professor H. B. Geinitz, to whom I submitted some of these fossils, determined them as Fusuline; but the Encrinital stems which occur in our Fusulina- limestone have, as Professor Geinitz informed me, a younger appear- ance, reminding him of the Triassic Encrinus Cassianus, Laube. _ This oldest sedimentary formation of Sumatra can be divided into two parts. The lower portion consists of clay-slates, with auriferous quartz-veins, mar]-slates, and siliceous schists; the upper part consists only of limestone, with some small beds of schists. This limestone contains the Fusuline ; but these fossils also occur in some limestone beds which are found between the schists of the lower part. The schists and the limestones are conformable one with another. They are widely spread all over Sumatra, and form great mountain-ranges in the Highlands; and are often accompanied by greenstones, which will be described hereafter. 3. Quartz-porphyries are probably younger than the schist- and limestone-formation ; some quartz-porphyries, at least, inclose frag- ments of schists; but it is not yet proved that all the quartz-por- phyvries of the Highlands are of the same age. _ These rocks always show, when examined with the microscope, an amorphous and so-called “ felsitic”” matrix, which is not resolved by the highest magnifying powers into crystalline grains. In this paste are imbedded crystals and grains of quartz (with many “‘ fluid-cavi- ties”), crystals of felspar (orthoclase and some oligoclase), and some fragmentary, green, dichroitic crystals, which belong to amphibole. 4, Greenstones. These rocks, as stated above, are often associated with the older schists and limestones, which are dislocated and heaved up by them, in such a manner that portions of those rocks lie some- times as islands upon the greenstones. The age of these rocks is not exactly known, but it is sufficiently proved that their eruption took place before the Tertiary Period, and that they consequently are not to be confounded with the greenstone-trachytes of Hungary. The Sumatran greenstones are pyroxenic rocks, partly diabases, partly Rk. D. Verbeek— Geology of Sumatra. 479 pyroxene-porphyries. They have a dark-coloured matrix, in which are imbedded crystals of faint-white plagioclase, green pyroxene, and magnetite. The magnetic iron-ore shows partly octahedral forms and large crystals; and it occurs copiously in excessively small grains throughout the matrix, which is coloured dark by it; and it is also found inclosed in the crystals of pyroxene. The crystals and grains of magnetite, even in the thinnest microscopical slices, are always opaque. 5. The Tertiary deposits, which follow next, are to be sub-divided into four groups. a. Breccias, conglomerates, arkoses (sandstones, derived from decomposed syenite, granite, and quartz-porphyry), and mar/-slates ; the last contain remains of Fishes and Plants. This lower part of the Tertiary formation is called the ete ag or Breccia-group. ‘The thickness. differs greatly at various lo- calities. b. Sandstones, with clays and coals. Some Fishes and Plants. The thickness of this portion, called the Sandstone-group, varies from 300 to 500 métres. c. Mari-sandstones. Shells, etc.. The thickness of this group is at least 500 métres, and at some places probably much more, d. Limestone, with Corals, Shells, etc., and abounding with Orditoides. The thick- ness is 120 métres. 5a. The breccias and conglomerates contain fragments of the several older rocks,—syenite, granite, quartz-porphyry, Fusulina- limestone, schists, etc. The arkose is asandstone whose substances have been derived from syenite, and partly also: from quartz-porphyry ; the beds of coarsest grain contain balls of hard syenite ; the beds of finer grain alternate with beds of the most remarkable rock of this group, namely, the marl-slate. These marl-slates have proved to be fossiliferous at several locali- ties on the Rivers Stpang,! Malakoetan, Sangkaréwang, Loera Ge- dang, and in the neighbourhood of the village of Telaweh; they contain Fishes and Plants. Between the marl-slates occur very thin beds of hard shale; and it is remarkable that the Fishes are always imbedded at the bottom of the marl-slates. It is thus probable that the Fishes lived in the water which deposited the shales, but that the great quantity of lime contained in the water which deposited the marl-slates was unfavourable to their existence. The marl-slate was deposited in the neighbourhood of the old coasts as a littoral deposit, and received the land Plants from the coast. 5 6. The sandstones of this group are composed of quartz-grains cemented by an argillaceous paste. The colour is yellowish or brown. This is the Sumatran Coal-formation. The beds of coal vary in num- ber and thickness at different localities; and they are generally near the base of the series. The Oembilien Coal-field contains about 200 millions of tons (1 ton=1000 kilograms). In the northern part of this coal-field, seven or eight coal-seams are known ; in the southern portion, the so-called Soengei-Doerian Coal-field, there are only three 1 The pronunciation of the Dutch vowels is the same as in German, except the ve, which is the German %; thus the Dutch a is pronounced as the English a in are, the e as the ¢ in latter, the ¢ as a in male, the 7 as ¢ in he, and the ve as oo in good. 480 R. D. Verbeek— Geology of Sumatra. seams, but these are of considerable thickness. The section of this series in the neighbourhood of the village of Soengei-Doerian, from bottom to top, is:— Thickness in Métres. Sandstones and clays ... ... 0+ fog 60 Gon Nose!) son HO) GaloRs) OP Ike). First (lowest) coal-seam 600. 000. G00" 'Gd0", dod) O00 SINGRTONES Gril GIES Goo cog Con a0" 000500 G0 poo PA) Second (middle) coal-seam ... .. ona 500 ogo Carbonaceous shale, with fossil remains Bere yeni a ee avlyons > Sandstones and clays 005 000. :000 496 p00. 200 Bon goo LH Third (upper) coal-seam 000 000 000 «00, «ca 0 =“ Sandstones and conglomerates ... ... ... se ee «ee 200 (more or less). Total thickness of the series 350 (more or less). _ Total of coal 10 The coal from the Oembilien coal-field is the best in the Netherland Colonies; and indeed, although of Tertiary age, is among the very best coals known. ‘The composition, according to the analysis by Dr. Vlaanderen, at Batavia, is: — ~T owotang “IH & ~I0 © SsouonDaoed 100-00 The theoretical evaporating power, according to this composition, A=T7500. It is a black, shining, lustrous, and compact coal. As the Soengei- Doerian seams are very regular, they are under very favourable circumstances for working. The clays are found immediately beneath the coal-seams. The second (middle) coal-seam is covered by a carbonaceous shale, half a métre thick, which is remarkable for its fossil remains,—spines and teeth of Fishes. ‘The sandstones contain no fossils; the coal and the clays only a very small number of fossil Plants. 5 c. In the marl-sandstone series, although of considerable thick- ness, there are only found some small Operculine and little Fish-teeth, in the neighbourhood of the village of Moara-Bodi, and some frag- ments of Shells, belonging to Ostrea, Pecten, etc., which prove that the marl-sandstone is a salt-water deposit. 5 d. The upper part of the Tertiary deposits, which are known in the Sumatran Highlands, is a limestone offering a great variety of fos- sils,—Corals, Echinids, Gasteropods, and Conchifers, mostly as casts, and a great many specimens of an Orbitordes. These four groups of strata generally succeed one another conform- ably, but in some localities there is a fault between 5b and 5c. The lower series, 5a and 5b, rest unconformably on the Limestone with Fusuline. The preliminary determination of some fossils from these beds, for which I am very much indebted to Prof. T. Rupert Jones, York- town, Surrey; Prof. H. B. Geinitz, Dresden; and Prof. O. Heer, R. D. Verbeek — Geology of Sumatra. 481 Ziirich ; showed that the four series or groups 5a, 5b, 5c, and 5d, belong to the Tertiary, and probably all to the Eocene period. Among the Fishes from 5a Prof. Geinitz determined Fistularia Kenigi, Agass., which occurs in the Hocene schists of Glarus (Swit- zerland) ; some other Fishes strongly resemble Osmeroides (subgen. Sardinoides, v. d. Marek) microcephalus, Miinst., and Osm. (Sard.) Monasterii, from the “ Plattenkalke” of Sendenhorst, Westphalia, which are of Senonian age (described and figured by v. d. Marck in “ Paleeontographica,” vol. xi. pl. 6, and Agassiz, “ Poissons fossiles,” vol. v. pl. 60d). The fossil Plants from 5a have a more Miocene than Hocene cha- racter. Some have already been described and figured by Prof. O. Heer in the “‘ Abhandlungen der schweizerischen paliontologischen Gesellschaft,” vol. 1. 1874. According to Prof. Geinitz, there are some Hchinids from 5d nearly related to Prenaster Alpinus, Desor (Desor, ‘‘ Synopsis des HEchinides fossiles,” 1858, p. 401, and W. A. Ooster, “ Petrifications remarquables des Alpes Suisses ; les Echino- dermes,” p. 112), and to Periaster subglebosus, Desor (op. cit. p. 385) and W. A. Ooster (op: cit. p. 109), both from Eocene or Nummu- litic rocks of Switzerland. It is therefore highly probable that 5d belongs to the Eocene period. As 5d is the upper part of all these sedi- mentary deposits, the formations dc, 5b, 5a, must be of Hocene age too. It is not at all probable that 5a belongs to the Upper Cretaceous (Senonian) formation, firstly, because the Senonian character of some Fishes from.5a is easily explained, the Marl-slates being the oldest of all our Hocene deposits, and the fossils from the Senonian ‘‘ Plattenkalke”’ of Sendenhorst, although older, having a strong resemblance to those from Hocene rocks of other parts of Europe; secondly, beeause rocks of Cretaceous age are wanting in the Highlands of Sumatra; thirdly, because the Marl-slates at the top of the series become sandy, and pass into the coal-bearing sandstones of 56, which are most probably of Tertiary age; fourthly, because the fossil Plants from 5a have a Tertiary, and even: more of a Miocene than Eocene, character. The Eocene formation of Sumatra is thus represented in four groups, or étages. That of Borneo, according to my investigations, is only re- presented in three groups. ‘The lowest of these latter contains the coals ; the middle part consists of marls, with some few Nummulites (Nummulina Pengaronensis, Verb.) and many specimens of Orbitoides discus, Riitim.); the upper part is a nummulitic limestone with millions of Nummulites and some Orbitoides. Perhaps the coal-bearing sandstones of Borneo are the equivalent of the Sumatran coal-bearmng formation 5b; the Borneo: marls, the equivalent of the marl-sandstones 5c; and the nummulitic limestone of Borneo may be the equivalent of the limestone with Orbitoides 5d; in which case the equivalent of the marl-slates with Fishes would be wanting in Borneo. But as there is a very great difference between the Eocene fossils from Borneo and those from Sumatra, this can only be proved by a careful comparison of the fossils. Those which I gathered at Borneo will soon be described by Dr. O. Bottger, Frank- fort-on-the-Maine ; Dr. von Fritzsch, Halle; and Dr. Geyler, Frank- 482 fi. D. Verbeek— Geology of Sumatra. fort-on-the-Maine ; and the memoirs will appear in the “ Palzonto- graphica.” (See two memoirs of mine, on the geology of the South- eastern part of Borneo, in the “Jaarboek voor het Mynwezen in Nederlandsch Oost-Indié,” Amsterdam, 1874 and 1875. I have formerly described the Nummulites of the Borneo limestone in the “Neues Jahrbuch fiir Mineralogie, etc., 1871, pages 1-14, pl. i. ii. iii.) The coal-bearing sandstones of the south coast of Bantam, in Java (not those in the interior of Bantam, which are younger), according to Mr. F. Junghuhn’s description (Junghuhn’s “ Java,” ete, Ger- man translation, Leipzig, 1852, part ili. pages 163-179), are covered first by marl-stones and clays, and next by limestone, which contains Nunimulites more to the east, on the River Kaso (Junghuhn, “Java,” part ili. pages 64, 87, and 203); and Prof. von Hochstetter confirms the occurrence of these fossils in the limestone to which the cavern of Linggo-Manik belongs (“ Novara-Reise; Geologie,” ii. page 146). It seems to me highly probable that these three series of rocks of Java are the equivalent of the rocks of Borneo described above ; and that thus the coals of Java and Borneo, and perhaps those of Sumatra too, belong to the same part of the Hocene period. In order to avoid errors, I must state here that in several parts of the Archipelago coal-beds are also found m rocks which are younger than Hocene; but these coals belong to the brown coal, and are always much inferior in quality to the black Eocene coals. These brown coals are found, 1. in the interior of Bantam (Java), in the neighbourhood of the village of Bodjong-Manik ; 2. in the neighbourhood of Doesson- Caroe, in Lais and Kataoen (Benkoelen, Sumatra), and Palembang (Sumatra) ; and 3. in the marls of the Island of Nias. 6. The Trachytic rocks of Sumatra are all younger than the Hocene period; they are of middle and late Tertiary age (Miocene and Plio- cene); and it seems that this is the case in Borneo and Java also. There are two different groups of trachytic rocks ; the one, probably the older of the two, composes mountains and mountain-ranges, with- out craters, and having no connexion with volcanos; the other com- prises the trachytic rocks belonging to the volcanos, those giants of Sumatra and Java, which are often more than 10,000 feet high. The trachytes of the first class, found in Sumatra in the immediate neighbourhood of Padang and Sibogha, and at several other local- ities, are oligoclase-trachytes, the so-called andesites (Zirkel) ; they contain no sanidine, but exclusively a triclinic felspar, either with amphibole (and now and then some quartz and mica), or with pyroxene. _ These andesites are widely distributed in the south-east part of Borneo, where they have dislocated the coal-bearing rocks; they are known too in Java. The rocks composing the volcanos of Sumatra are of various kinds ; there are andesites, trachytes with sanidine and oligoclase, trachyte- pitchstones (Trachytpechsteine, with sanidine and without oligoclase), obsidians, and pumice-stones. The volcanos of the Highlands of Padang are named :—the Talang, the Singalang, the Merapi, the Sago, and the Ophir. The Singalang and the Merapi are about *4u000IT “pues vos “fp *‘SyUL [V.10Q *¢ ‘({ Me.0T[T) VUTTUMUINY TTVUIg TTA ‘souojsomrT OUTTIV.LOD *% ‘(ade auoo01y;, Jo Atqeqo.id) souojspuvs-ArIQ pue SOUOJSPUYS-[LIRI ‘SBI “TL NG “Oy = ey a, Seay Ss ‘SVIN #0 GNVIST FHL «0 Tuva NUGISE A FHL LO NOLOTG OILVNNVUOVIG, “TIT “OLY “WOEANTTY °8 “49907, UST [Teus ou0s] pus eulfnordO YIM souojspuvs-Av[Q pur ‘souojspuvs-peyl ‘drow auojspuvs~junpy ‘ac | ‘aucoogr *UOTJVULIOF ‘SUONVULIO] f ‘“BUI[NSN|A WITM oUo}sOUMITT °9% “4999.0, USM WIAA oTBYS snosovuogirvo pue (») spo IIA souoyspuvg ‘dn0wy awojspuny “g¢ ( Arejuouttpas 1a8un0z Axeyuauttpag zaplO ¢ ‘s}SIOg snosor[Ig ‘soqzv[s-AvlQ +z “S}UBTY PUL SOTSTA UTA ‘soyv[s-[rVT ‘Ssouojspurg ‘sviovetg ‘dnouy vw0aug “DG yes) + +453 ' is Niet Riri) G 4 i S44 +7 F Sf ' i AY FF 1 ae i 1 1 H H \ i ! H ‘suepyy uel100q ‘oyedury suolfpury, SS N / \Welnaniees NN Wad N \ We em Ny RY 5% 96 Hy a DG \\ \\ \ ‘(‘uor}oeg eT) Ur payuosordoar you ‘untantiq *2) ‘soyATOVLy par sajisapuy °9 *SOPIOIGIO YIM auozsaweT auryyv.009g °pg “Arkydiod-ouax01kg puvoseqviqy “F *(uor}008 94} Ul poyuesatdaa you) Atkydiod-zy1enh *¢ ‘oqo ‘ojtuadg ‘oyluRIgQ *T oN a ange da Tg 3 4qa4t 4 TII4 H Mpa ye) VIA TAG i / LA45 BD iy DR) Ife i ye 2 H * d i) eats SS ya 9¢ i H “ee | Co | 1 ' “yore “suvped “ONVOHL) NVIUHOT OL YNVGVG WOUL VALVWOY AO NOILOMG OILVNWVUNVI(] “[][ “Sly 484 Li. D. Verbeek—Geology of Sumatra. 10,000 feet high; the others are lower, but all the volcanos of Sumatra surpass 6000 feet. The volcanos of Java are described by Mr. Junghuhn in his above-mentioned work. Borneo contains no voleanos. The mountain Kina-Baloe, in the northern part of Borneo, which was formerly supposed to be a volcano, is composed of a granitic rock. There are two lakes in the Highlands of Padang which owe their origin to infallings of volcanic ground on a very large scale. The greatest length of the Lake Singkorah is 21,000 métres, the greatest breadth 7700, the smallest breadth 3350, and the circumfer- ence 503,000; the surface is 2:04 square geographical miles. The only channel which carries off the water of this lake is the Oembilien River, which is afterwards called Kwanten, and finally Indragiri, and has its mouth on the east coast of Sumatra. The Lake Manindjoe is 16,600 métres in length, the greatest breadth is 8000, the least breadth 3650 métres ; the circumference is 48,900 métres, and the sur- face 1:81 square geographical miles (1 geogr. mile=1/,,° of the Equa- tor). The water of this lake is carried off by the Antokkan River, which has its mouth not far from Tikoe on the west coast. The surface of these two lakes is, in comparison with other lakes in volcanic districts, as for example the ‘‘ Maare ” of the Hifel, very con- siderable. The surface of the Lake Singkorah is 33 times, and that of the Lake Manindjoe 29 times greater than that of the Lake of Laach (Laacher See) in the Hifel. 7. The Diluvium of the Highlands of Padang is a river-deposit ; and is chiefly composed of tufaceous conglomerates and sandstones. The beds are always horizontal, and contain many fragments of trachytes. These are two characters by which the Diluvial conglom- erates are easily separated from the conglomerates of Hocene age. The Diluvial beds form river-terraces, which attain a height of twenty to thirty métres above the alluvial deposits. 8. The Alluvial river-deposits are for the greater part trans- formed into rice-fields (sawahs). In the Section Fig. 2, the western part of Sumatra is represented from Padang, on the west coast, to the village of Doerian-Gedang, near the frontier of the independent districts. The eastern part of Sumatra, from Doerian-Gedang to the east coast, is not given in the Section, as that part is composed only of recent deposits of the Rivers Djambi, Indragiri, and Kampar. With the exception of the quartz- porphyry (8) and the diluvium (7), all the above-described rocks are represented in the Section. The four groups of Hocene deposits are generally conformable with each other, but unconformable to the old Fusulina-limestone ; but, as was stated above, in some localities there is a fault between 5b and dc. IIl.—The Island of Nias (Government of the West Coast of Sumatra). See Fig. 3. This island is situated westward of Sumatra; its surface is about 70 square geographical miles. It is chiefly composed of marls, clay- Li. D. Verbeek—Geology of Sumatra. 485 marls, clays, and very fine-grained sandstones, partly of tufaceous nature. It is most probable that the materials of the greater part of these rocks were derived from volcanic rocks, but on the Island of Nias itself no such rocks occur. The beds of marls, clays, etc., are very much dislocated, and vary much in direction and in dip ; they are seldom horizontal. They have a bluish-grey colour; and are probably of Miocene age, according to Dr. O. Bottger, to whom I submitted some of the fossil Conchifers and Gasteropods from these marls. In the neighbourhood of Goenoeng-Sitolie, the chief place of the island, and also at some other localities, the marls are covered by an unconformable limestone. It is remarkable that this limestone, probably (from its discordant position) of late Tertiary age (Pliocene ?), contains, besides indistinct fragments of Corals, some small Nummuline. It is a new proof that this genus not only occurs in rocks of Eocene age, but in younger rocks too. The diameter of the Nummuline from the Nias limestone is three millimétres, the thickness 1 to 14 millim.; they have eight whorls, about 150 chambers, the central chamber is small; their in- ternal structure resembles very much that of the Hocene, N. Pen- garonensis, Verb., from Borneo, and perhaps they are a small variety of that Nummulite. . The position of the different rocks in the neighbourhood of Goeneng- Sitolie is shown in the Section Fig. 3. For those who feel interest in the Geology of Sumatra, I add a list of the principal geological papers on parts of that Island. . F. Valentin. Oud en Nieuw Oost-Indién, 1724. Sumatra, in vol. v. . William Marsden. History of Sumatra, 3rd edition. London, 1811. . Malayan Miscellanies ; published at the Sumatran Mission Press, at Bencoolen: vol. ii. (1822) contains accounts of several journeys. 4. Dr. Jack. On the Geology of Sumatra. Transactions of the Geol. Society, new series, vol. i. page 397. 5. Memoir of the Life and Public Services of Sir Thomas Stamford Raffles. By his Widow. London, 1830. Particularly in the Government of Java, 1811-1816, and of Bencoolen and its dependencies, 1817-1824. 6. L. Horner. De Batoe-eilanden. Tijdschrift voor Nederlandsch Indié. Jaar- gang iii. vol.i. p. 318-871. 7. L. Horner, Reizen over Sumatra, Tijdschrift van het Bataviaansch Genootschap, vol. x. pp. 822-378. 8. S. Miller. Gezigten van bergen, kraters, kusten en eilanden van Java, Sumatra en straat Sunda. Verhandelingen over de natuurlijke geschiedenis der neder- landsche overzeesche bezittingen, door de leden der Natuurkundige Com- missie. Leyden, 1839-1844, pp. 447-469 (with plates). 9. F. Junghuhn. Die Battalander auf Sumatra. Berlin, 1847, 2 vols. 10. F. Junghuhn. Java (German translation, Leipzig, 1852), vol. i. pp. 51, 70-72, 75-78, 99-106, with seven sections (topography of Sumatra) ; vol. ii. pp. 808— 816 (volcanos of Sumatra). 11. Mieuwenhuizen en v. Rosenberg. Verslag omtrent het eiland Nias. Verhandelin- gen van het Bataviaansch Genootschap, vol. xxx. 1863, pp. 1-153. 12. W. H. de Greve. Het Oembilienkolenveld in de Padangsche Bovenlanden. ’s Gravenhage, 1871. 13. &. D. M. Verbeek. In the “Jaarboek voor het Mijnwezen in Nederlandsch Oost-Indié,” vol. iii. and iv. 1874 and 1875, the following momoirs : a, Preliminary report on the Island of Nias. wre 486 J. G. Goodchild—On the Origin of Couwms. b. On the age of the Oembilien Coal-field. c. Geological description of the Oembilien Coal-field. d. On the Geology of the Island of Nias, with several maps and sections. Fort van der Capellan, West Coast of Sumatra, March 10th, 1875. IJ.—On tHe Oricrn or Covums. By J. G. Gooncuitp, F.G.8., of H.M. Geological Survey. N my paper on Glacial Erosion lately laid before the readers of the Grou. Mac. (pp. 823 and 356), I have endeavoured to prove that the origin of nearly all the more prominent surface character- istics of the rock scenery in the Yorkshire Dale District admits of a simple and complete explanation by the theory of the modification of pre-existing subaerially eroded surfaces by Glacial Erosion. At the same time it was shown that the character of many of the phe- nomena is entirely opposed to any theory of their origin by means of Subaerial Denudation alone. In the present communication it is proposed to inquire how far this Glacial Erosion theory may be applied to explain the origin of the deep, semicircular recesses that are commonly found in all well-glaciated mountainous districts, and are variously known by the names of Coums, Corries, or Cirques. The more prominent terraces and scars whose origin was discussed in the paper just referred to seem to occur only where the ice moved in the direction of the valley’s length: where the ice flowed toa greater or less degree across the valley, or, in other words, where the ice moved across, instead of along, the outcrops of the beds, these characteristic scars and terraces are either slightly developed, or else are wanting altogether. But whatever the minor inequalities of the slopes of the valleys may be like, it is commonly found that there is a striking resemblance in form between the contours of the surface at any given elevation and the contours for a considerable distance both above and below. Where the side of the valley is convex in contour, the gradations in form are complete between the curves of largest radius near the bottom of the valley, and the more decidedly rounded contours of lesser radius that are found in greatest perfection at the higher parts of the feature. So, too, with the slopes that present concave contours. In these the least regular curves are nearly always found near the base, and the contours gradually become more decidedly concave and of larger radius as the upper limits of the feature are approached; and, as a rule, it is also at the upper limit that the most regular curves occur. Some of the rock surfaces whose form I have before endeavoured to show must be due to the unequal resistance to mechanical erosion offered by beds of various degrees of hardness graduate, by insensible degrees of form, from surfaces with contours that are nearly straight, through others that are more or less concave, into semicircular recesses that remind one rather of gigantic pot-holes than of anything else. A very beautiful example of this kind occurs at the head of Snaizholme Beck, about a mile to the south of Hawes, in Wensleydale. Others of similar but less perfect form may be found in the neighbourhood. J. G. Goodchild—On the Origin of Coums. 487 In all such instances that have hitherto come under my notice, both in the Dale District and elsewhere, there are certain points of resem- blance common to all. In their lower parts, many, perhaps nearly all, hardly differ in any noticeable respect from the steeply sloping head of an ordinary valley, except that they are, perhaps, of some- what greater width. The bottom of the hollow is almost invariably occupied by a stream, of which a part is often so much enlarged as to form a tarn, and in a few cases the tarn can be shown to lie in a true rock basin. Looking upwards at the higher parts of the coum from the position of the tarn, one cannot fail to be struck with the sweeping outline of the walls of the amphitheatre as these are seen against the sky. In many instances the curve is so regular, and so little interrupted by stream courses, that it seems rather as if the shape had been produced by artificial means than by purely natural causes. Viewed from the sides, at a higher elevation, the regularity of the curvature is quite as obvious. From such a point, too, one can see how markedly the valley-like form of the amphitheatre’s lower part contrasts with the sweeping curves of the parts nearer the top, and how gradually the contours change in form from one ex- treme to the other. Above the line where the greatest regularity of form is observable the coum frequently terminates somewhat abruptly among rock features that do not present any striking or unusual peculiarities. In nearly all cases it is abundantly manifest about all such amphitheatric recesses that they are slowly, but surely, losing their regularity of form and smoothness of outline. Wherever a spring bursts forth, the continuity of the curves is more or less in- terrupted, and the slopes below are encumbered with the rock that has been thus undermined; and the gully formed by any stream that flows downwards from the edge of the coum is quite unlike any part of the smooth, concave surface of the other parts. That very little denudation has taken place in Post-Glacial times in these cauldron- like hollows is evidenced by the presence, high up on the sides of the hollows, of glacial drift that in a few cases can be shown to date from the last ice-sheet period; moreover, glacial striz are found in a few instances in such a position and with such directions that it is plainly impossible that the form of the surface can have undergone any important modification since it was left by the great ice-sheet— a view that is further borne out by the general freedom of the drift surface from fallen rock fragments from above. Indeed, in a few instances it would seem as if so much of the old weathered part of the rock was removed by the ice-sheet that subaerial forces have only just begun to produce any noticeable effect upon the sweeping outlines of the surface. It may be true that in the case of many coums these remarks do not apply ; but if they can be shown to be true of one only, it proves that in that particular instance the pecu- liarities of surface configuration have been produced by other agencies than those now at work upon the surface. Several theories have, at different times, been advanced to account for the origin of these singular crater-shaped hollows; but hitherto no thoroughly satisfactory explanation has been given. Where 488 J. G. Goodchild— On the Origin of Coums. they occur in rocks of tolerably uniform lithological character throughout great thicknesses of strata, there does not seem to be much difficulty in accepting the theory that attributes their origin to the combined action of springs and meteoric agencies. But where, as in the Lower Carboniferous rocks of the north-west of England, we find them just as perfect in form in a series of rapid alternations of horizontal strata that have very different rates of destructibility under any kind of disintegrating influence, many difficulties arise which plainly show that this theory is untenable. In the paper referred to at the head of this communication it has been shown that, under purely subaerial influences, the form of the surface that would be developed out of any such series of rocks as those in the Dale District would be in many respects different from what we actually find. Just to take one objection—ali the springs in the Dale District tend more or less to break out along certain definite lines, most frequently between a limestone and the less pervious grit or sand- stone that it lies upon. Hence, the tendency of springs, as they act rather by undermining than by actual erosion, would be in nearly all cases to cut back the beds above that whereby the spring is thrown out. As a result, the lower bed would soon be left as a shelf projecting beyond the outcrop of the next bed above; unless there happen to be springs below which undermine the impervious bed at the same rate as that maintained by the higher springs. Hven in that case the result would soon take the form of a gully or ravine, in no way different from an ordinary bed of a stream; and it is obvious that unless springs were acting simultaneously over the whole surface—or, what amounts to the same thing, unless the springs are continually changing their point of outburst so that the whole rock surface is uniformly acted upon—the result must inevitably present a jagged and irregular contour at all elevations ; which is a form of surface totally unlike almost any unmodified part of a single coum that f have ever seen. Again, the objections brought forward against the subaerial origin of the straight lines of scar in the Dale District apply equally well in these cases; because it frequently happens that the more prominent rock features in the coums consist of the kinds of rock that, under subaerial influences, tend to disappear with the greatest rapidity, while, at the same time, they are the rocks that are best capable of withstanding erosion by mechanical means. Besides these objections there are others that are set forth m the paper on Glacial Erosion. But even if these objections did not suffice to show the untenability of the Spring Theory, the existence of such one-sided pot-hole-like hollows in rocks of very different litho- logical character and lying at every imaginable angle seems to shake one’s faith in any of the theories that have yet been proposed to account for their origin. In the case alluded to, which is along the Cross Fell Escarpment between Melmerby and Ousby, in Cumberland, the rocks forming the coum consist of highly inclined and contorted Lower Silurian ; thick masses of vertical and highly J. G. Goodchild—On the Origin of Coums. , 489 inclined Carboniferous conglomerates belonging to the Calciferous Sandstone Series; and variously inclined beds of Lower Carboni- ferous rocks of the ordinary Dale District type. Yet the general regularity of form and the uniformity of curvature of the crater-like recess that all the rocks have been ground into is particularly striking when one is aware of the nature and the lie of the rocks that form the walls of the amphitheatre. This instance is one of many others in the neighbourhood, all of which are remarkable for their sweeping outlines and general regularity of form. In regard to the position of these coums no very general rule can be laid down. ‘They seem, however, to occur with greatest frequency in the neighbourhood of the highest ground, especially where there is much diversity in the directions taken by the larger valleys. Nota few coums occur at the heads of valleys, of which the Snaizholme Coum may be taken as a very good type. They are, however, by no means confined to such situations, but occur almost as commonly on the sides of valleys, far removed from the source of the stream. In a few instances such recesses are found in considerable perfection on the sides of a main valley opposite the point where this is joined by a tributary of considerable size. Good examples of such are to be found in the Coum wherein Bolton Castle in Wensleydale stands, just opposite where the Yore valley is joined by the large branch dales of Waldendale and Bishopsdale; at Bampton near Shap, where the valley of the Lowther is joined by the Hawes Water valley; and again at Lowther Park, where Heltondale and the Lowther valley join. Many similar cases to these might easily be pointed out if there were further need to do so. In some of these instances the most regularly curved outlines are found only within a small vertical extent of the hollow where they occur; in other instances the curvature is so slight that, on the ground, it seems almost imper- ceptible; but a reference to the beautiful one-inch maps of the Ordnance Survey shows that these seemingly unimportant curves are in reality but parts of curved surfaces of much greater extent, whose real nature can only be seen by looking at them from a considerable distance, from which point the curve is often seen to inclose an are of sixty, eighty, or even a greater number of degrees. The three coums referred to above are shaped out of a series of alternations of hard beds with others comparatively soft in regard to their capacity to resist mechanical erosion, and the rocks they occur in are more or less inclined from the horizontal ; yet the resulting terraces in each case are equally well developed at one point as at another. In the case of the Lowther recesses the rocks and their terraced outcrops incline inwards towards the high ground; yet, although there is in this instance a combination of circumstances most favourable for the retention of rock debris detached by subaerial agencies, hardly a fragment of any of the harder rocks is to be found loose at the surface, which seems as if it had been swept clean from one end to the other; except where a thin coating of drift has been left by the melting of the ice-sheet. 490 J. G. Goodchild—On the Origin of Coums. Similar remarks apply also in part to many other such recesses in like positions. Now, as an ordinary glacier scoops, necessarily, only in a downward and outward direction, we ought to find, if the theory of the origin of coums by means of glaciers were the true theory, that all traces of horizontal prominences have been ground off by the ice; and, in place of terraces extending at right angles to the path the ice must * have taken, we ought to find whatever furrows the ice left, in, or nearly in, the line of motion of each part of the bottom of the glacier. Yet, it is a well-known fact that where the rocks that form the coum consist of a nearly horizontal set of alternations of beds of different degrees of hardness, each separate hard bed forms an amphitheatric shelf or terrace, which is separated from those above and below it by a horizontal interval, often of considerable extent ; so that the general effect resembles, on a gigantic scale, the tiers of seats in a great amphitheatre. This is especially noticeable in the case of many of the cirques in the Jura, some instances of which have been mentioned by the Rev. T. G. Bonney in his paper on the origin of Cirques. It is clearly impossible that any such ledges of rock can be due to the erosive power of ice acting vertically ; and therefore, as very perfect coums exist to which the theory of glacier erosion will clearly not apply, we are forced to conclude with Mr. Bonney that simple glaciers have had little, if they have had anything, to do with the formation of the greater number of the coums, either here, or on the Continent. — There are some other and perhaps not less weighty objections against the glacier origin of coums. It has been before re- marked that the greatest regularity of form is often to be found only near the higher parts of the recess; while, in their lower parts, many of the coums do not differ very much from the higher parts of ordinary valleys, except that in a few cases they are flatter, or rather wider than one usually finds the head of a similar valley where no coum exists; and that rock basins on a small scale often occur at the foot of the steeper slopes. It seems quite clear that if the coums are due to the scooping out of a valley head by the long-continued action of a small glacier, the greatest amount of erosive force must have been exerted in those parts of the coum that had the greatest over- burden of ice—in the higher parts, where the neve was hardly sufficiently consolidated to deserve the name of ice at all, the amount of erosive force exerted must be very small indeed. Yet the lower parts are those that, in many instances, do not differ very much from ordinary valley heads ; while at the higher parts, where the glacier ice can have exerted little or no erosive power, the configuration of the surface plainly shows that the erosive agents have acted with the greatest effect. Again, where tiers of rock ledges occur one behind another, as they do in some of the English coums, and more strikingly in those of Switzerland, it is also obvious that the coums cannot be due to the undermining of the higher rocks by a glacier that was grinding away the soft beds at the lower part of the recess. Such action, where the rock is of a uniform lithological character, might J. G. Goodchild—On the Origin of Coums. 491 give rise to a rudely semicircular hollow with steep craggy walls ; but it is quite impossible that this, or any other vertically acting force could ever give rise to tiers of rock shelves with the unbroken sweeping curves that actually occur. Lastly, many, perhaps the greater number of coums occur in such situations that, if they had ever been tenanted by a glacier, this, in consequence of the nearness of the hollow to the snow-shedding line, must rarely have exerted much pressure upon its bed; even supposing that, in such a situation, the neve was sufficiently consolidated to take on the properties of ice in any form. If, then, perfect coums exist where, under glacier con- ditions, there could hardly have been sufficient pressure to consolidate the neve in the bottom of the coum into ice, much less near its upper margin, it seems clearly impossible that an ordinary glacier, or, indeed, ice in any form moving in the way that a glacier does, could give rise to the crater-like recesses whose origin is here discussed. The widely different elevations that adjoining coums are found at, and the entire absence of any marks of erosion in their neighbour- hood that can clearly be shown to be the work of the sea, are objec- tions of sufficient weight to convince most field geologists that very few indeed of these pot-hole-like hollows have received their present form by marine action. All who have followed Professor Ramsay in collecting facts relat- ing to Glacial Hrosion have remarked upon the association of well- glaciated rock surfaces with coums and rock basins; and, probably, they have all felt more or less convinced that this association is something more than accidental. The close resemblance of many of the coums to gigantic pot-holes, such as, on a small scale, a mountain torrent drills in its bed, seems to point to some analogy in their modes of formation; and this view is considerably strengthened when it is found that the position of not a few of the coums bears the same relation to the direction, position, and relative sizes of the adjoining valleys that the position of their smaller analogues do with regard to the direction, position, and relative sizes of the rock channels that cause the eddies in a river. In the paper on Glacial Erosion an attempt has been made to prove that all the minor features of the scenery in the north-western part of the Dale District are due to mechanical erosion by land ice, which in all probability rose to a level of at least 2400 feet above the sea, and may have had a greater thickness even than that. It was pointed out that the erosive powers had acted unequally upon the beds in proportion to their relative powers of resistance to mechanical erosion; and also that in some cases it is almost certain that a considerable thickness of rock must have been removed by the ice in this way. The eroding agent followed the pre-glacial configuration of the surface, removing much of the weathered part of the rock, and replacing the notched and irregular weathered sur- face, and the talus-covered slopes, by unbroken and sweeping lines of scar, terraces of unweathered rock, and slopes coated with little other superficial accumulations than the drift matter that had once been dispersed throughout the entire thickness of the ice-sheet over that particular spot. 492 J. G. Goodchild—On the Origin of Coums. Those who have read the paper thoughtfully will at least admit that if the ice-sheet really accomplished as much denudation as is therein claimed as its work, the very nature of the agent would lead us to expect results different in many important respects from those accomplished by purely subaerial means. Unlike a river, which can transport the rocky material it has removed only along some part or other of its bed, much of the debris detached from the old pre-glacially weathered and shattered rock surface by the ice that was slowly moving over it gradually worked its way into the body of the ice; where, being practically unaffected by the force of gravity, it quietly floated away in the higher and swifter flowing strata of the ice, towards the outer margin of the ice-sheet, leaving compara- tively little detritus between the sole of the ice-sheet and the rock surface. A little consideration will convince any one that an agent acting in this manner would erode as freely at an elevation lower than the rock surface a little further down the valley—in other words, in a rock basin—as at any other part of its bed; because, as fast as the detritus was removed from the rock, it tended more or less to work upwards into the body of the ice, where the more quickly flowing strata would soon remove it seawards. In the case of a river the force of gravity comes more strongly into play, so that, except in a pot-hole, when once a large stone gets much below the general level of the bed of the river, there it must lie, until some accident brings it again to the level of the river’s bed. Mr. Croll’s theory of the “Physical Cause of the Motion of Glaciers,” published in the Phil. Mag. for March, 1869, enables us to understand how ice, whilst possessing many of the properties of a fluid, may yet at the same time behave in many respects as a semi- solid. A proper appreciation of Mr. Croll’s theory ; of the theory put forward in the first instance by J. D. Forbes, and since extended by Mr. James Geikie, on the up-travelling of boulders ;1 and of the actual thickness that it can easily be shown that the ice really had; is, I think, all that is necessary to convince the most sceptical that the theory of the origin of rock basins by glacial erosion is the only theory that really accords with the facts. In all probability the greatly diminished rate of flow of the lower strata of the ice as compared with the flow of the strata near the surface, is quite com- pensated, so far as the erosive power of the ice is concerned, by the enormously increased pressure. Hence it is far from unlikely that the actual amount of erosion accomplished by the bottom ice may not be far short of, if it does not equal, or even exceed, the amount of erosion effected by the comparatively swift-flowing ice of the higher parts of a glacier’s sides. In order to rightly understand the theory that I have elsewhere given* to account for the origin of coums, it will be well to sum- marize a little of the evidence relating to the behaviour of a thick mass of land ice in motion that can be gathered from the sources at 1 On the Occurrence of Erratics at Higher Levels than the Rock Masses from which they have been derived, Trans. Geol. Soc. Glasgow, vol. iv. pt. 3, p. 239. * Quart. Journ. Geol. Soc. for Feb. 1875 (read 24th June, 1874). J. G. Goodchild—On the Origin of Coums. 493 present open to us. As, in the present state of science, we have no means of discovering what is actually taking place in and beneath the ice of a great continental mass like that of the ice-sheet of Greenland, we are compelled to rely upon the data supplied by the glaciated rock surfaces left by the ice of the European Ice-sheet Period, and to supplement these by the data, less satisfactory in some respects, that are afforded by the puny descendants of the Ice- sheet of Mid and Northern Europe. JHven in the Arctic regions we should hardly expect to meet with ice in a state precisely similar to what obtained during the Ice-sheet Period in England. Wherever perennial ice has lingered from the Glacial Period to the present day, the erosion of the old weathered surface by the ice must be greater in proportion to the length of time that has elapsed since the last traces of the Ice-sheet left these parts. When the Ice-sheet left the North of England, it is highly probable that there was much weathered rock left to furnish the materials for more drift; but in the glacier regions of the present day the ice has accomplished much more, and there is probably little else than perfectly sound rock left for the ice to erode. When we examine any large extent of nearly flat glaciated surface lying near the bottom of a deep valley, we usually find that most of the striz run for considerable distances without any great deviation and without interruption, and that the larger grooves, even those of an inch or more in width, are ploughed out in lines paralled to those of the finer scratches around. As a rule, these larger grooves bear no necessary relation to any structural planes in the rock, and they bear every appearance of having been produced at one operation by the steady grinding of the rock by the slow onward movement of the sole of the Ice-sheet armed with bigger stones than those that produced the adjacent finer scratches. As scratches of this character occur along the whole length of the bottoms of valleys, right up to the source, we need no other evidence to convince us that the very lowest strata of the old glaciers were impelled forward as well as the higher strata were ; and that, even at a considerable depth from the surface, grooves of large size could be made at one operation, although the absolute rate of flow of the sole of the Ice-sheet may have been so slow as to be almost imper- ceptible if it could have been tried by any of our most carefully constructed modern instruments. When it is remembered that a sheet of ice “1000 feet in thickness has a pressure on its rocky bed equal to about 25 tons on the square foot,”! and that the actual thickness of the ice in the Yorkshire Dale District equalled, and in places exceeded 1500 feet, the amount of erosion accomplished during the whole of the Glacial Period may have been something con- siderable. It is a very noteworthy point that where a large branch valley joins the main valley, the main valley striz are more or less deflected from their general parallelism with the larger contours of the part where they occur; and, what is of still greater impor- 1 J. Croll, On Geological Time and the Probable Date of the Glacial and the Upper Miocene Period, Phil. Mag. Noy. 1868. DECADE II.—VOL. I1.—NO X. 32 494 J. G. Goodchild—On the Origin of Coums. tance, Mr. Ward has lately pointed out before the Geological Society that in some of the Cumberland Lake Basins the lines of greatest depth are deflected in the same manner off the mouth of a great _ branch valley to such an extent that they run well in towards the shore of the lake opposite the mouth of the tributary. Turning to the facts obtained from a study of the behaviour of the Swiss glaciers, we find that where two glaciers unite at a considerable angle, the surface moraines of the more powerfully flowing glacier are impelled right across the path of the smaller glacier, in a few instances nearly to the opposite bank. Besides this, where the valley that a glacier flows in has many bends, the line of swiftest motion crosses the centre line of the glacier at each point of con- trary flexure, exactly as the line of swiftest flow of a river does under similar circumstances. Taking these facts into consideration, it will be seen that, inde- pendently of any theory whatever, we can feel a tolerable amount. of certainty that force can be transmitted horizontally for consider- able distances through ice; and the facts obtained from the glaciated surfaces seem to prove that force can be transmitted a considerable distance through ice, not only in a horizontal direction, but also to some extent in a direction approaching the vertical. It seems otherwise impossible to explain the occurrence of the phenomena referred to above except on a supposition of this kind. Those who accept Mr. Croll’s theory of glacier motion will at once perceive that these results are precisely such as might have been expected. In regard to the quantity of rock removed in this way by the ice from the bottoms of the valleys, we have as yet no trustworthy evidence ; but there is every reason for believing that the quantity of rock ground away from the lower parts of the valley’s sides was something considerable, hence it may be safely inferred that the valleys were also deepened in the same proportion. To repeat what was stated above—the ice certainly removed all traces of the pre- glacially weathered part of the rock from the lower ground, and in doing so, while in the main it followed the configuration of the surface left by subaerial agencies in pre-glacial times, it carved the rock surface into forms different in many respects from those re- sulting from subaerial action alone, and bearing characteristics such as can be impressed by the agency only of land ice in motion. If, then, there is no alternative but to refer the origin of the straight lines of scar in the Yorkshire Dale District to glacial erosion, it seems to follow that all the accompanying forms of the surface that they are associated with, and that they pass into by insensible gradations of form, must have originated in the same manner. If the slightly concave surfaces of the valley sides are due to the slow grinding of the stone-shod ice-sheet moving horizontally ina slightly curvilinear direction through long periods of time, the more deeply concave recesses that they graduated into, and that occur with them, have assuredly originated in the same way. The only difference in the two extreme cases would be, that in the case of the shallower coum local circumstances did not tend to deflect the ice much out of J. G. Goodchild—On the Origin of Coums. 495 its normal direction; in the other, local circumstances, which in many cases may have remained constant throughout the whole period of the Ice-sheet, caused the ice to move in a direction more decidedly curvilinear, so that in the end the rock surface was ground into its present form. If it be conceded that force can be transmitted considerable distances in any direction through ice, the analogy of a glacier with a river is complete in nearly every respect. We may, therefore, venture to specu- late upon the existence in the great ice-sheet of phenomena parallel to any that are known to occur in rivers. If we examine a shallow river about the point where it is joined by a tributary of considerable size, we usually find that the shingle on the bank of the larger stream opposite the point where it is joined by its affluent is swept away by the conjoined currents, so as to leave a kind of bay with a regularly curved outline, which varies in form and position with the relative directions and intensities of the two currents to whose joint action the deflection of the stream is due. Compare this with what occurs on a larger scale in rock masses: where the larger ice-filled valleys were joined by powerful tributaries, the bank opposite the point of junction is ground into a bay of exactly the same form as that swept out of the shingle by rivers of the same relative volumes under like circumstances. The stone-shod ice of the main stream was impelled by that of the tributary against the bank opposite the point of confluence, and the combined effeet of the two currents caused the ice to move in a more or less curvilinear direction, until it gradually mérged into the direction of the main valley, a long way farther down the stream. The Bolton Castle Coum is an excellent instance of this kind. The ice of the main valley, throughout perhaps the greater part of the ice-sheet period, was kept pressed against its north bank by the two powerful tributaries that came down Waldendale and Bishopsdale, whereby the conjoined streams were compelled to move slowly in a curve until they flowed again into the normal direction farther down Wensleydale. As the conditions that gave rise to the curvilinear motion remained constant throughout the whole of the glacial period, while the ice maintained not less than a certain thickness, it is quite possible that the result may be due, in this case, as in many others, to the long-continued action of com- paratively feebly acting causes bringing about results that seem at first sight to require more energetic action than that which it is here supposed gave them their present form. If we take the case of a powerful stream that is joined by a much smaller affluent—so small that its current produces no appreciable effect upon that of the main stream—it will be noticed that it very often happens at the point of junction that a kind of tangential action is set up by the two forces, so that part of the smaller stream is ponded back into its own channel and is compelled to move in a complete circle—backwards towards the head of the tributary, then round against the upper bank at the point of junction, and finally round into the direction of the main stream—before it can escape from its own channel. As a consequence, the shingle is often swept away 496 J. G. Goodchild—On the Origin of Coums. so as to leave a bay similar in form to that of the eddy above. Many coums occur in North-Western England whose origin is capable of explanation in the most complete and satisfactory manner by supposing that the greater ice-streams behaved to their tributaries in the same way that a strongly-flowing river does to the weaker _ tributaries that it is joined by. For instance, the ice of some of the small valleys coming down from the Cross Fell Escarpment into the Hden Valley, must, on meeting with the powerful stream that swept up the valley from the south-west of Scotland over Stainmoor to the North Sea, have been affected by a kind of tangential action, so that much of the tributary ice at high levels was compelled to move backwards in a rudely circular direction until it merged into the direction of the main stream. As a consequence, we find that on nearly every one of these tributaries some of the higher lying scars, where the currents were freest to move, are ground into crater-like recesses that, when viewed from a distance, remind one of nothing so much as of gigantic pot-holes that have had one side cut away. Where a stream flows over a rock that is much fissured, so that a great diversity of directions is imparted to the lower currents of the stream, we find that the whirling motion thus produced has caused the rock to be drilled into numerous pot-holes, which vary in shape, position, and size, with the rapidity of the stream, the nature of the rock, and the direction of the larger fissures. The resemblance be- tween the valleys and coums of a mountainous district, as they are seen on a good hill-shaded map, to the wider joint fissures and pot- holes seen in a river’s bed, strongly inclines one to the opinion that the analogy between them is complete in nearly every respect but that of size. In the one ease, the pot-holes in the river’s bed are due to the eddies caused by the variously directed minor currents result- ing from the inequalities of the river’s bed; in the other, the coums seem to be due to the much larger eddies caused by the variously directed valley streams in the great river, or rather sea, of ice that once overspread perhaps the tops of our highest mountains in the northern parts of our islands. In the one case, the pot-holes have been due to rapid and comparatively intense action in a brief space of time ; in the other, their larger analogues, the coums, have received their form through slowly, and perhaps feebly, acting causes con- tinuing throughout a period of time so long that we can form no conception of its immensity. It will therefore be seen that it is here considered that, as the orgin of coums—the so-called Giant’s Cauldrons of Sweden—the “round and deep holes with polished sides” that occur on the sides of the Swiss valleys in situations “where the form of the surface will not permit us to suppose that any cascade could ever have existed,”’—and the existence of similar pits in the rocky bed of lake basins—all admit of the most complete and _ satisfactory explanation on the assumption that the analogy between the behaviour of a glacier and that of a river, which is known to be almost complete in the puny representatives of the old ice-sheet, 1 Lyell, Elements, 5th edition, p. 149. Dr. Walter Flight—fistory of Meteorites, 497 was, under the extreme conditions that obtained during the ice-sheet period, complete in every respect, the hypothesis that many of these cauldron-like hollows are due to the eddying of the ice must be accepted until it can be shown that this hypothesis is clearly disproved by any of the facts. IJ].—A Cuarrer 1n THE History oF METEORITES. By Water Fuieut, D.Sc., F.G.S8., ° Of the Department of Mineralogy, British Museum. (Continued from page £12.) 1853, February 10th.—Girgenti, Sicily.’ It is probable that the history of this fall has unfortunately been lost to science. Vom Rath has recently endeavoured, but without avail, to gather information from Gemmellaro, of Palermo, respecting what now appears to have been a shower of stones rather than the fall of a single meteorite, as hitherto supposed. Gemmellaro was unable in 1869 to discover any persons who witnessed the fall; as, however, it appears that two years after the occurrence Greg” was informed that an account had been printed in a Sicilian scientific journal, more particulars of the fall may yet be obtained. The two fragments examined by vom Rath were partly covered with a black crust forming an undulating surface, with occasional little prominences that revealed the presence of nickel-iron. The structure of the rock is chondritic, of a light greyish white, is finely — granular, appearing to the eye almost uniform in texture. A frac- tured surface exhibits a great number of exceedingly fine black lines which seem to have their origin in the crust, although, from their diminutive size (they are generally only to be recognized with a lens), it is, says the author, difficult to believe that they are filled with fused matter. (Compare with Meunier’s observations on the black lines in the Aumiéres meteorite, page 401.) They form a tangled mesh-work enclosing the spherules and rounded crystalline grains of olivine; and they are most abundant round the granules of magnetic pyrites, which they occasionally traverse. The nickel-iron is less abundant than in the Pultusk meteorites, and besides forming rounded or hackly grains, occurs, as in the Krihenberg aerolite, in fine veins. The magnetic pyrites (troilite?), which is more abun- dant than the preceding mineral, takes different hues, and both it and the granules of chromite are grouped together in small circles, which give the rock a more distinctly chondritic character. Spherules of sufficient size to project from a fractured surface and capable of being detached are rare; some, however, have a fibrous structure and a pale green colour. Under the microscope the mass of the rock is found to be an aggregate of white crystalline grains; in it one 1G. vom Rath. Pogg. Ann., 1869, cxxxviii. 541.—S. Meunier. Compt. rend., 1878, Ixxvi. 109. 2 R. P. Greg. Phil. Mag. xxiv. 534. * 498 Dr. Walter Flight—History of Meteorites. small yellowish-green crystalline plate having the appearance of mica was noticed. The specific gravity of the stone is 8°549, a number intermediate between those yielded by the Pultusk and Krihenberg meteorites. The Girgenti stone contains 8°83 per cent. of nickel-iron having the composition : Tron = 8738; Nickel = 12°7; Total = 100-0. Here again the proportion of this constituent is intermediate be- tween that found in the meteorites just mentioned ; and in composition nearly the same as the nickel-iron of Krihenberg. The non-magnetic portion, amounting to 91:7 per cent., which, by reason of the small amount of material available for analysis, was not subjected to the separating treatment of acid, was found to consist of $10, Al,0; FeO MnO MgO CaO NaO? Fe § Chromite 43-41 1:57 17:96 trace 26°84 1:85 1:50 3:43 2°24 1:20 = 100-00 If the chromite and the iron sulphide, which as it occurs in the portion of the stone unacted upon by the magnet is probably troilite, be deducted, the silicates have the following composition : Oxygen SUDKORD EXEL Conqoacsavaqo00E aioe EO GE. Seclene 24-19 FAUGTAIN» oct cata snowed escie 15-6 Slates 0°78 Tron sprotoxilerece-eecssseceece UH) onan 4°33 IMaeiesiaeeecderescscsnsedeeeces 5 PIED cooese 11°55 MAM OEE ante walacorescecece sesetne, Waa OU meee ce 0:57 SOUR (G9) ococetesdosocbocnqancno3 LE aacdco 0°66 The oxygen ratio of the total bases to that of the silicic acid is 1: 1-352. As this is obviously a mixture of silicates, it seems not improbable, both from the structure of the stone and the analytical determinations, that it consists, as in the Krahenberg rock (see page 22), of an olivine of the form FeO, MgO, SiO, (like that also occur- ring in the meteorites of Chateau-Renard and Kakova), and a nearly pure magnesian enstatite, as the following scheme indicates : FeO, MgO, Si0,. MgO (CaO), SiO. Oxygen. Oxygen. Silicic acid..........0+.+« ‘8°66 15:53 Tron Oxide .....0.c0sceces 4°33 RYae (000 ae Midonesia 2. .ccecscenence 4°33 cee ac 7-79 TIC) Meta se seas aerate hesteon —— wee LORS For the reason already mentioned the presence of cobalt and of the alkalies could not be directly determmed. Found 1854.—Tuceson, Pima Co., Arizona. This remarkable mass of iron, of which an account is given. in Bartlett’s ‘‘ Personal Narrative,”? has been chosen by von Haidinger 1 W. von Haidinger. Siteber. Akad. Wiss. Wien, \xi. April heft. 2 J. R. Bartlett. Personal Narrative of Explorations and Incidents in Texas, New Mexico, California, Sonora, and Chihuahua. 1854. New York: Appleton & Co. Page 297. ° Dr. Walter Flight—History of Meteorites. 499 to illustrate some remarks on the rotation of meteorites. It measures 4 ft. 1 in. by 3 ft. 3 in., weighs about 1400 lbs., and is in the form of aring. When first found, it was set up as an anvil. Von Haidinger points out that the greatest extension of the iron is in the plane of the ring, and that the rotation must have taken place in this plane. The question arises: What would be the effect the resistance of the air will exercise on a plate of iron of unequal thickness? In the centre of the compression, and therefore of the expansion, the air, he finds, would be compressed together in a con- dition resembling that of a solid body. What then will be the effect on a large mass of rock, the uneven surface of which is subjected to the unequal action of a temperature of fusion? The stone will be bored into, as the Gross-Divina stone has been to a considerable depth ; a similar phenomenon has been remarked in other meteorites. While this will be the effect on brittle stony material, in the present case the resistance of the air, operating on a plate three to four feet in diameter of viscous metal, will be more rapid and energetic. The plate will in process of time be penetrated at one point, and by the gradual expansion of the orifice it will eventually develope into a ring, and arrive in this form on the earth’s surface. The meteoric iron which was seen to fall at Agram, Croatia (1751, May 26th), has the form of a plate, and bears evidence of having been subjected to the same eroding influence, though in a less degree. Had it been continued to the depth of another inch this iron would have been perforated, as in the case of the Tucson ring. The above is a representation, one-twentieth the actual size, of this curious mass, which is preserved in the Smithsonian Institu- tion, at Washington. The figure is reproduced from von Haidinger’s memoir. 500 Dr. Walter Flight—HMistory of Meteorites. 1855, June 7th._St. Denis-Westrem, near Ghent, Flandre orientale, Belgium.' The earlier descriptions of this meteorite are by Duprez? and Haidinger.* Meunier states that the rocky portion of this meteorite accords in all its characters with that of the stones which fell at Lucé, Sarthe, France (1768, September 18th), Mauerkirchen and others, as well as with that of the meteorite of Sauguis St. Etienne, Basses-Pyrénées (1868, September 7th). The latter rock, to which he has given the name of “lucéite,” is described as white and finely granular, rough to the touch and eminently crystalline, and having the specific gravity of 343. He reproduces from another of his memoirs the results of his examination of the last-mentioned stone, and to this we shall presently direct attention. No analysis of the Belgian meteorite appears to have been performed. The paper is chiefly devoted to theoretical considerations respecting the stratigraphical arrangement of the star-masses whence the meteorites are supposed to be derived. Meteorites, he maintains, are the pro- duct of the breaking-up of larger celestial bodies at the completion of their development, and the moon, he considers, is now approaching this stage of her existence. Found 1856.—Hainholz, near Paderborn, Minden, Westphalia.‘ This member of the small class of siderolites, originally described by Wohler, von Reichenbach, and von Haidinger, has recently been submitted to a careful chemical examination by Rammelsberg. It was remarked by von Reichenbach that the olivine of this meteorite formed unusually large crystalline masses, the faces of which, how- ever, were destroyed by weathering; one crystal was 1? in. long and 14 in. in breadth. Two specimens of this meteorite were found by Rammelsberg to have the composition : INMOR@IAIROMN 656. ono 00 coo AIMS) ote cn, PO) Chromuitemeeecuaecsn neteneiec een Ol Ome mmaeee men Ona ObwabS 9565 Gon Goo 080 = oon | ORY Sho San BROS IBLONZIULC! She s.ne sessile sese evel) 2 OSL OM test mee iene 00 100-00 100:00 The metallic portion consists of : Iron = 93°84; Nickel = 6:16 Total = 100-00 and the two silicates have the following composition : Si02 Al20, FeO MgO CaO A. Soluble Es OOG IE. caves le ——v dee pone edule ine — nt — 00200 13, JESUIT 5g OPO cg SUD cg GB cn PED) PE SOOO 1§. Meunier. Bull. Acad. Sc. Belgique, 1870 [2], xxix. 210. (See also F. Duprez, Bull. Acad. Sc. Belgique, 1870 [2], xxix. 161.)—Acad. royale de Belgique. Centiéme Anniversaire de Fondation (1772-1872). Tome II. Rapport séculaire (Sciences minérales), par G. Dewalque, 23. 2 F. Duprez. Bull. Acad. Sc. Belgique, 1855 [2], x. 12. 3 W. von Haidinger. Sitzber. Ak. Wiss. Wien, 1860, xlii. 9. 4 C. Rammelsberg. Monatsber. Akad. Wiss. Berlin, \xx. 314.—C. Rammelsberg. Die chemische Natur der Meteoriten. Abhandl. Akad. Wiss. Berlin, 1870, 94. See also Ber. Deutsch. Chem. Gesell. Berlin, 1870, ii. 528. Dr. Walter Flight— History of Meteorites. | 501 The soluble part, which constitutes more than one-half of the stone, is an olivine in which the ratio Fe to Mg is 1: 8, the same proportion as that met with in the Linn Co., Shergotty and other meteorites. In the insoluble portion we have a bronzite in which the ratio of these two metals is the same as that of the olivine accompanying it, and as that in the enstatite of the Shalka aerolite. In the latter meteorite the bronzite is not associated with nickel-iron. ‘The con- stitution of these two ingredients of the Hainholz siderolite may be represented by the formule : Fe Si0, 3 Mg2 $104 l, 3 Found 1856 (?).—Jewell Hill, Madison Co., N. Carolina." This iron has been found by Tschermak to enclose thin plates of troilite like those he recently noticed in the meteoric iron of Ilimaé, Desert of Atacama, Chili. (See page 73.) The lamelle are just as abundant and have the same orientation as those of the Chilian iron, and are about one-third the size. According to the analyses of Tschermak and Dr. Lawrence Smith, these metallic masses have nearly the same composition. In a volume of his papers collected and published in 1878, the latter author? states that the Jewell Hill iron reached his hands in 1854. 1857, February 28th.—Parnallee, Madura District, Madras, India. [Lat. $° 14 N.; Long. 78° 21’ E.]* Several notices of this remarkable fall, the larger aerolite of which is preserved in the National Collection, have appeared: three by von Haidinger, and three by 1). Cassels, by 2). Pfeiffer, who sub- mitted the rock to analysis, and 3). by Maskelyne, who studied its minute structure under the microscope. Meunier publishes the results of a lithological study of this stone, which he finds to have a very complex structure, and to present in its leading features great similarity with the meteorites of Cabarras Co. (1849, October 31st), Mezo-Madaraz (1852, September 4th), and Bremervérde (1855, May 18th). Its structure has been described as pisolitic: Meunier, on the contrary, likens it to a coarsely granular grit. The grains composing it are often angular, sometimes more or less rounded, and in each instance have the characters of fragments which have been detached from larger masses: the rock, in short, is a breccia. By a careful examination of the four specimens preserved in the Paris Collection, the author has noted the presence of twelve distinct species of grains: 1). troilite, sometimes in fragments of large size; 2). nickel-iron, in rounded or markedly angular fragments ; 3). greyish green translucent peridot, presenting the appearance of having been rolled; 4). chromite, enclosed in a whitish rocky matrix; 5). a grey 1G. Tschermak. Denkschrift Wien. Akad, Math. Naturw. Classe, xxxi. 187. 2 J. L. Smith. Mineralogy and Chemistry, 317. 3 §. Meunier. Compt. rend., 1871, lxxiii. 346. 502 Dr, Walter Flight— History of Meteorites. laminated mineral, with pearly lustre, which is probably hypersthene or amphibole. The remaining seven species, which may more appropriately be designated rocks proper, are divided by the author into two groups, according as he has, or has not, been able up to the present to identify them as individual lithological types constituting distinct meteorites. In the latter group he enumerates 6). a grey scoriaceous rock, free from metallic particles; 7). a dark grey rock, enclosing them ; and 8). a bright grey slightly ochreous rock, prob- ably the altered product of another species. Meunier is of opinion that any one of these three species may at some future period be found to constitute an individual meteorite. The remain- ing four species are: 9). a white granular rock, enclosing nickel-iron and troilite; this variety, which occurs in about thirty of the meteorites in the Paris Collection, he has termed lucéite; 10). a rock of the whiteness of plaster and enclosing small black grains ; this is the ‘chladnite’ of the Bishopville meteorite, now shown to be magnesian enstatite, MgO, SiO,; 11). a rock, perfectly black and very tough, containing grains of nickel-iron and troilite, such a mate- rial, met with in the stone of Tadjéra (1867, June 9th) and the meteoric irons of Deesa and Hemalga, has received the name of tadjérite ; and 12). the last species, is a greenish grey friable granular highly crystalline rock, containing no metal but small grains of chromite ; from its resemblance to the meteoric rock of Chassigny (1815, October 3rd), and in fact by reason of its highly olivinous character, it has received the name of chassignite. The presence, says the author, in the ‘polygenic conglomerate’ of Parnallee of fragments belonging to seven types at least of distinct meteoric rocks, demonstrates the co-existence of these types in the star-mass whence this Indian meteorite came. 1858, December 24th.—Murcia, Spain.' This meteorite, which was shown at the International Exhibition of Paris in 1867, is in the form of a right parallelepiped with square base, the dimensions whereof are 39 centim., 40 centim., and 27 centim. It weighs 114 kilog., considerably surpassing in size the average of rock masses of meteoric origin. This meteorite is remarkable for its hardness. The crust, which is nearly perfect, has evidently turned since the fall of the stone from black to brown. On the fractured surface grains of nickel-iron are seen, few of which retain their lustre, as well as an iron sulphide of a bronze hue which is abundantly disseminated through the mass. Besides these are remarked, what form a distinguishing feature of this rock, very small extremely brilliant crystalline particles, some- times in minute veins, which appear to be metal, but really have vitreous lustre. They fuse before the blowpipe to a grey enamel, and give the reactions of silica and alumina. They are probably a 1 §. Meunier. Thése présentée a la Faculté des Sciences de Paris, 1869. Recherches sur la composition et la Structure des Météorites, 9, et seg. (See also G. A. Daubrée and §. Meunier. Compt. rend., 1868, Ixvi. 689.) ye Dr. Walter Flight—History of Meteorites. 503 felspar or an analogous mineral species. Though by their brilliancy and transparency they resemble quartz, the feeble action which they exert on polarized light suffices to distinguish them. In a microscopic section the presence of a large amount of a black opaque ingredient ~ was recognized; grains of a sulphide with a sub-metallic lustre, duller along the margin, are very abundant ; while others much smaller and very black were identified with chromite. The stony matter enclosing these substances is made up of two ingredients of different aspect: the one, of a reddish-yellow colour and very transparent, presents the flawed characters usually observed in the siliceous portion of meteoric rocks; the other is of a darker hue and less homogeneous. The material chosen for analysis, taken from the blackest, and consequently less altered portion of the meteorite, had the following _ composition : INiekel=ironeequecnycsciinsssuniccny eset ress enOou Troilite Bo eat ee ah oragat aseee eal he eee 2 ORO LO Chromite. eke, teks ecsln ices ele nese, 10ng2 Solubleysilteatemeawessc eis semen OOROCO Insoluble silicate ... se. ss» «soe ooo 24°640 99:°758 The nickel-iron consists of: Tron = 90:93; Nickel = 9:07; “Total = 100-00 The troilite, constituting one-fifth of the stone, is present in larger quantity than in any meteorite previously investigated. The siliceous portions are composed as follow : SiO, AlO; FeO MgO CaO Na,O K,O Chromite A. Soluble 38°725 — 12932 47-206 0-233 0-904 — -— =100-000 B. Insoluble 55°719 1:996 9:880 37:806 — — trace 3599 =100-000 The soluble portion consists chiefly of an olivine having the same composition as that occurring in the meteorites of Tadjéra and Pul- tusk, while the insoluble part appears to be for the most part a pure magnesian enstatite, with perhaps a small amount of the aluminous mineral already alluded to. 1858.—Trenton, Washington Co., Wisconsin. [Lat. 43° 22’ N.; Long. 88° 8’ W.]* In the autumn of 1858 a farmer while working on his farm in Section 33, Washington Co., struck his plough against some hard object about 10 inches below the surface; it proved to be a mass of meteoric iron weighing 621bs. It appears that four pieces, two of which weighed 16lbs. and 73 Ibs., were found, in the years im- mediately following, within a circuit of two or three rods of the spot where the largest was discovered. Dr. L. Smith gives the weights of the masses: 62 ]bs., 16lbs., 10]bs., and 8lbs., and the composition of the metal as written below (I.), side by side, with the 1 J. L. Smith. Amer. Jour. Se., 1869, xlvii. 271. Mineralogy and Chemistry, 349.—F. Brenndecke. Annual Rep. Smithsonian Inst. for 1869, 1871, 417.—J. A. Lapham. Amer. Jour. Sc., 1872, iii.69. (See also Part I. Grou. Mae., page 380.) 504 Dr. Walter Fhght—Mistory of Meteorites. results of an analysis by Bode (II.), which is incorporated in Brenndecke’s report on these meteorites presented by him to the Society of Natural History of Wisconsin : iL. TI. TRON Se paiva ayips ta veese A Sp sea tp IO COS) & Aas wewceae OO ToD: INielcel yy vem isc soscaape ces aise O) a. ceaeeenall Oz) Cobaltycs Meow can fcce worse eT ORG Onn come eer ace Phosphorus... .. coo WIE tag cag Ss OD) Copper Boor cots tad trace! f. se. = Insolublesesicue aes mec onet ean Os OME enn 99°35 100-70 SUNG aR, = Boo! ‘aso coo UO sep coo °C Bode states that the Widmannstittian figures are developed with great distinctness. Dr. Smith arrived at the same result, and finds that the spaces between these figures, which have convex ends and sides, are darker in hue than they are, and exhibit striations, the lines being at right angles to the bounding surfaces; these forms he terms ‘Laphamite markings.’ When the space where they occur is nearly square the lines extend from each of the four sides; in other cases they are parallel to the longer sides. He considers that these figures indicate “the axes of minute columnar crystals, which tend to assume a position at right angles to the surface of cooling.” The author does not describe what phases these figures assume when the iron is cut in various directions. 1859, May —.—Beuste, Basses-Pyrénées.! This meteorite has recently been acquired for the Paris Collection. Two fragments, weighing respectively 1:40 and 0-42 kilog., were found about 700 metres apart, the former having penetrated the soil to a depth of about 50 centim. The black crust has a thickness of 0-4 to 0-5 mm., and the specific gravity of the stone is 353. It belongs to the class of which the Chantonnay meteorite (1812, August oth) is a representative, and consists, it may be presumed, as it has not yet been analyzed, chiefly of olivine, bronzite, and labradorite. The stone has a grey colour and a compact structure. The frac- tured surface is traversed in all directions by black veins which anastomose. 1860, May lst—New Concord, near Zanesville, Guernsey Co. and Muskingum Co., Ohio.’ A note on the fall of these meteorites, copied from the Zanesville Courier, apparently contains no new information beyond what has already been recorded in Buchner’s Die Meteoriten, 104. Found 1861.—Rittersgriin, near Schwarzenberg, Saxony. For a short description of the probable composition of this sidero- lite see the Breitenbach Meteorite. (Lo be continued in our next Number.) 1G. A. Daubrée. Compt. rend. 1873, lxxvi. 314. 2 Amer, Jour. Sc., 1871, 1. 309. Dr, Thomas Wright—Cotylederma in the M. Lias. 505 IV.—On THE OcourRENCE OF THE GENUS COTYLEDERMA IN THE Mippiter Liss or DorsEtsHIReE. By Tuomas Wricut, M.D., F.R.S.E., F.G.S. ROFESSOR QUENSTEDT, in his Handbuch der Petrefakten- kunde (1852), first described and figured, under the name Cotylederma, a remarkable fossil which he found adherent to the sur- face of Ammonites striatus in the upper region of the Lias ¢. It formed a flat, sessile, cylindrical little bowl, composed of five plates, with five blunt angles, and was referred by him to the class Hchino- dermata and the order Crinoidea. The learned author, in his “der Jura” (1858), says that he has found it attached to Ammonites lineatus and A. striatus in the upper region of Lias y, at Aselfingen, and that it was comparable to the calyx of a crinoid. Professor EK. Deslongchamps, in his valuable memoir: “Sur la Couche a Leptena” (Mémoires de la Societé Linnéenne de Nor- mandie), described and figured several forms of this genus, which he had found in a very richly fossiliferous stratum of Middle Lias at May and Fontaine Etoupefour (Calvados). The Cotylederma are very singular Crinoids, of which we only know the Calyx or Pelvis. They have the form of little cups or tubes, and adhere directly by their base to submarine bodies without any trace of astem. ‘These ‘remarkable fossils are very abundant at May, and from this locality Professor Deslongchamps obtained many specimens, among which are several new species, as Cotylederma miliaris, Desl., Cot. fistulosa, Desl., Cot. docens, Desl., Cot. vasculum, Desl., Cot. Quenstedti, Desl. M. Terquem collected a species of Cotylederma sessile on an ammonite in the Middle Lias (Department of the Moselle), in a bed with Ammonites Davei, Sow., and which was identified as the Cotyle- derma Quenstedti, Desl. MM. Terquem and Hd. Piette (Lias Inférieur de l’est de la France, p- 128) have subsequently detected this genus in the Lower Lias Limestone with Ammonites bisulcatus, Brug., at Fleigneux and at Jamoigne in the Hast of France, where they found six individuals of different ages; five were attached to Gryphea arcuata, Lam., and the sixth and largest specimen to Pleurotomaria anglica, Sow. These they have described and figured as C. Oppeli. ‘‘'The base is firmly adherent, lobed into five or six divisions ; the superior border thin, round ; interior conical smooth. Dimensions: Diameter of the base, 6 millim. ; diameter of the opening, 2 to 3 millim.: depth, 2 millim. The specimens are very rare.” My friend F. Longe, Esq., F.G.S., whilst examining the Lias Coast Section last August between Lyme Regis and Charmouth, found a nodule at the base of Down Cliffs which he thinks belongs to bed d, “ Blocks of indurated Sandstone,” of Mr. Day’s memoir on the Middle and Upper Lias of the Dorsetshire Coast. (Quart. Journ. Geol. Soc., 1863, vol. xix. p. 285, fig. 4.) This nodule contained a specimen of Cotylederma, having a portion of shell adhering to its base. The fossil is conical, obliquely inclined to one side; the base is expanded, and was apparently adherent; and the summit is 506 Notices of Memoirs—Prof. Gaudry— rounded and open. The body consists of five unequal-sized calcareous plates closely soldered together, and having their surface covered with small granulations. The plates are each slightly convex, and the lines of the sutures well defined. The species appeared to me to be identical with one of the forms figured by M. Deslongchamps in the memoir referred to from the Middle Lias of May. Without committing myself to any opinion as to the true position of Cotylederma in the zoological series until I have an opportunity of examining the structure more in detail, I desire now only to record the fact of the discovery of this genus in the Middle Lias of Dorset, as it is the first English specimen of this curious form of the Liassic Sea which I have yet seen in any collection from our Lias beds. IN Or nk@atS §}@ 22) jaVisken/E@asey Ss PoE ets J.—On tHE Discovery or BarracHIA In THE Upper Panmozorc Rocsns or France. Sur Ja découverte de Batraciens duns le terraine primaire, par M. Albert Gaudry. 2,Bulletin de la Société Géologique de France, 8¢ série, t. iii. p. 599, pl. vii. et viii. N the spring of the present year M. Albert Gaudry communicated an interesting paper to the Geological Society of France, on some newly discovered remains of true Batrachia found in the older rocks of that country, and which paper has just been published, with two plates, in their Proceedings. This discovery is paleeontolo- gically important; as the author observes that up to the present time no remains of actual typical Batrachia have been found in any rocks of earlier date than the Tertiary Period. It has also been a subject of surprise, that Vertebrates of so low an organization should have appeared so late upon the earth, and this supposed fact has been used as an objection to the theory of progressive develop- ment. However, this discovery, he thinks, shows structural cha- racters, such as an evolutionist would expect to find in an ancient rock. The tail very short, the bones of the trunk and limbs resembling those of the Salamanders, whilst on the contrary the bones of the head have the characters of those of the Frog; thus lessening the distance which appears to separate the Urodela from the Anoura. He further remarks, that the incomplete ossification of the centra of the vertebre, the want of ossification of the epyphyses of the limb bones, and probably, also, the cartilaginous state of the carpals and tarsals, reveal a type of which the evolution is not yet completed. Like the earlier Mammalia, these Batrachia are very small, thus giving them the appearance of animals not fully de- veloped. But he thinks it probable that most of the individuals he examined were adults, for they varied but little in their proportions. The specimens were found at Muse (Saone et Loire), and at Millery, in the schists from which petroleum is extracted. At this place a slab was obtained showing remains of seven individuals more or less perfect. These schists are considered by some geo- logists to belong to the upper beds of the Coal-measures, but are Batrachia in Upper Paleozoic Rocks. 507 more generally referred to the Permian Formation; but this diver- sity of opinion is of little importance in regard to these remains, as it is certain that these bituminous schists belong to the upper series of the Paleozoic rocks of France. Remains of seventeen individuals have been obtained, one only being from Muse; the two largest are respectively 45 and 385 millemetres long from snout to end of tail, whilst the Muse specimen is but 80 millemetres in length. Although the skeleton appears smaller, M. Gaudry does not think it constitutes a specific difference. The osteological characters, and the points of agreement with, or divergence from, the corre- sponding bones in the Frogs and Salamanders, and also in some of the extinct genera of the Amphibia, are fully stated; but these comparisons, although interesting, are too long for quotation. The osteological evidence for considering these remains to be those of true Batrachia are, the large size of the head of Protriton, the great eye orbits, the absence of the suprasquamosals, and also of the entosternum and episternum, together with the very small ribs, —these characters have a marked resemblance to the Batrachia, and more especially to the Salamanders. There are, however, some important differences; notably the head is relatively very much larger than that of the aquatic Salamanders, and is also propor- tionally larger than in the terrestrial Salamanders; the vertebre are not so completely ossified; the neck has three vertebre, the Salamander but one; the dorsal and lumbar vertebre are shorter and more numerous; the ribs are less arched ; the lumbar vertebrae carry no ribs, and the tail is only a fifth of the total length of the body, whilst in most of the Salamanders it is equal to the half of the entire length. The anterior and posterior limbs are directed backwards, thus more resembling the Ganocephala than the Batrachia. It is probable, when more perfect examples of Protriton are found, in which the bones of the scapular and pelvic arches are shown, that more numerous differences than those at present observed may separate Protriton from the Urodela. M. Gaudry thinks that Apateon pedestris, v. Meyer, from the bituminous schists of Appel Minster, is closely allied to Protriton, and that Prof. Wyman is of opinion that Raniceps (Pelion) Lyelli, from the Coal-measures of Ohio, is also a true Batrachian. There is therefore evidence of the early existence in Geological time of members of this family in France, Germany and North America. He proposes the name Protriton petrolei, as indicating that these remains are the predecessors of the Salamanders, and that they were first found in rocks producing petroleum.—W. Davizs. IJ.—On vee Formation or Meraniic SULPHIDES AND OTHER MINERALS IN THE THERMAL SPRING OF BouRBONNE-LES-BAINS (HaurE-Marnr). By M. Daubrée. Comptes Rendus, vol. ixcxexeei onions N carrying out some works connected with the thermal spring of Bourbonne-les-Bains, some interesting facts have been brought to light. At the bottom of an ancient well, a bed of blackish mud 508 Notices of Memoirs— was found, containing in its upper part many vegetable remains, and in the lower, numerous medals of bronze, silver and gold, as well as other works of art of Roman age. Below this was a bed consisting principally of fragments of sandstone, which were more or less cemented together by metalliferous minerals definitely crystallized. M. Daubrée’s attention was directed to this interesting circumstance by the Minister of Public Works, who had received specimens from the chief engineer of mines, M. Trautman. Notwithstanding the resemblance of these minerals to those of older geological date, they have evidently been produced after the embedding of the Roman medals with which they were associated, for, in many instances, the medals were encrusted and enveloped by them. The following species were recognized :— Copper Glance, in crystals similar to those found near Redruth, in Cornwall, and associated with Covelline. Copper Pyrites crystallized and mammillated. Erubescite in regular octahedrons, and cubes with faces slightly curved. Tetrahedrite in crystals with its usual lustre and other characters, and from the analysis representing a type nearly free from arsenic. Of these minerals, the most novel is the formation of the double sulphide of copper and antimony constituting Tetrahedrite, for the other species have been previously observed under somewhat similar conditions in other localities. Besides these, occur numerous rounded grains of quartz, cemented with sulphides, as well as some doubly-terminated crystals of the same mineral, resembling the Compostella Hyacinth. Whilst some of these are derived from the grés des Vosges, others appear to have been the result of a contemporaneous crystallization with that of the Tetrahedrite, etc. The formation of these sulphides is evidently connected with the thermal spring, the water of which contains in solution chlorides and sulphates of the alkalies, lime and magnesia, as well as bromides, and carbonates of iron and lime, an alkaline silicate, and traces of arsenic and manganese. The solid contents are about 7 to 8 grammes per litre, and the temperature is about 60°. In explaining the formation of these metallic sulphides in the midst of the mud and under the influence of the mineral water which has constantly penetrated it, M. Daubrée considers that the sulphates have been partially reduced to sulphides by the action of the vege- table matter present, a well-known reaction in nature. The presence of antimony, an essential element in tetrahedrite, is particularly interesting, for, though its presence has been determined in mineral springs in other localities, it has not been recognized at present in that of Bourbonne-les-Bains. It has been, therefore, probably derived from the minerals used in the mannfacture of the bronzes, traces of this metal having been found in ancient bronze by M. Fellenberg. The medals present a curious modification. Most of them, whilst retaining their general form, have lost their sharpness of outline, so M. Daubrée—Formation of Metallic Sulphides. 509 that, while the interior still shows the lustre and colour of bronze, the exterior consists of a white earthy crust, consisting chiefly of oxide of tin, slightly coloured by traces of copper salts. Thus, by reason of the different chemical affinities of the metals composing the medals, the copper has entered into sulphur combinations, whilst the tin has passed into the state of oxide. This accounts for the mode of occurrence of tin, which is generally found in the state of oxide, even when sulphides, as mispickel, are found associated with it in the same vein. The antimony, notwithstanding its analogies with tin, differs from it in these modern products, as in metalliferous veins, by being invariably in combination with sulphur. The silver medals are not altered. Geologically short as is the time during which these reactions described by M. Daubrée have taken place, yet they supply import- ant results, and afford new evidence of the influence of mineral springs in the formation of metallic sulphides, such as may partly assist in explaining the filling of mineral veins with similar sub- stances. Further research has brought to light other facts, as the occurrence of galena, anglesite, mammillated limonite, and iron pyrites. The cavities in the bricks used in the conduit for the thermal waters are sometimes found lined with small rhombohedral crystals of chabasite, also some small colourless crystals having the form of rectangular prisms similar to those which occur under analogous circumstances at Plombieres, and which are referred to phillipsite or lime-harmotome.* It thus appears that the zeolitic minerals of the two localities cited, as well as at Luxenil previously described by M. Daubrée,’ are the result of similar reaction, producing silicates which did not originally exist in the concrete, but which have resulted from the long-continued action of the contents of the thermal waters upon the materials used in the construction of the conduit. It is to be remarked that the water of Bourbonne-les-Bains differs considerably from that of Plombieres, which contains a far less amount of soluble salts, about 3 gramme per litre; this difference has, however, not affected the formation of zeolites in both. M. Daubrée concludes by pointing out that thermal springs, flow- ing at limited depths and at slight pressure, produce mineral sub- stances which have not yet been formed in our laboratories. How important, then, must be their effects at greater depths and greater pressure, reacting upon the different rocks which they traverse, and thus produce changes at present veiled to our view, but which should not be overlooked in the consideration of formations which come within the ken of the mineralogist and geologist. J. Morris and Tuomas Davizs. 1 Comptes Rendus, t. xlvi. p. 1806. (1858.) 2 Bulletin de la Société Géologique, 2nd ser. t. xviii. p. 108. (1860.) DECADE II.—VOL. Il.—NO. X. 33 510 Reports and Proceedings— IS SOun~ns) JNANpiIb) 2>ssJOOumap DDI CrS)- I.—June 28rd, 1875.—John Evans, Hsq., V.P.R.S., President, in the Chair. 1. “Some Observations on the Rev. O. Fisher’s Remarks on Mr. Mallet’s Theory of Volcanic Energy, read May 12th, 1875.” By Robert Mallet, Hsq., F.R.S., F.G.S. The subject of the Rev. O. Fisher’s paper has been anticipated by one from Prof. Hilgard (Geol. Univ. of Michigan) published in the ‘ American Journal of Science’ (vol. vii. June, 1874). The pith of the Rev. O. Fisher’s communication is to a great extent comprised in the two following sentences :— 1st. That “if crushing the rocks can induce fusion, then the cubes experimented upon ought to have been fused in the crushing ? ” 2nd. “If the work (of crushing) is equally distributed through- out, why should not the heat be so also? or if not, what determines the localization ?” In his reply Mr. Mallet controverts the views of the Rev. O. Fisher by bringing them into contact with acknowledged physical laws. He shows that “ crushing alone of rocky masses beneath our earth’s crust may be sufficient to produce fusion. He also shows that the heat developed by crushing alone cannot be equally diffused throughout the mass crushed, but must be localized, and that the circumstances of this localization must result in producing a local temperature far greater than that due to crushing. Lastly, he shows that after the highest temperatures have been thus reached, a still further and great exaltation of temperature must arise from detrusive friction and the movements of forcible deformation of the already crushed and heated material.” He therefore expresses his conviction that “there is no physical difficulty in the conception involved in his original memoir,’ but not there enlarged upon in detail, that the temperatures consequent upon crushing the materials of our earth’s crust are sufficient locally to bring these into fusion.” Discussion.—Prof Duncan remarked that this reply to Mr. Fisher’s paper, which is not yet in print, was one which required careful thought and consideration. He thought that Mr. Mallet had not considered sufficiently the effects of tangential thrust. The curving of strata takes place along great planes, producing main synclinal curves; but there was another series of actions giving rise to thrusts over smallerareas. In any case the action of the thrust would be slow, and thus it can furnish no parallel to experiments by crushing rocks, in which the effect is rapidly produced. He further pointed out that volcanos do not follow mountain- chains, and that the crust of the earth has no doubt become more rigid than formerly, and that therefore tangential thrusts would now be less effective. Volcanic cones are found in older rocks than the Eocene. Prof. Ramsay said that he agreed with Prof. Duncan in general, but thought that the meaning of quick and slow was difficult to define in connexion with great thick- nesses of strata. If the pressure was sufficient to maintain motion, this might be quick in one sense and slow in another. Alterations may be gradually going on over great areas, by which means metamorphism may be evidenced in different degrees in different parts. 1 Phil. Trans. 1873. Geological Society of London. 511 The President remarked that at a depth of 5 miles the pressure upon a rock would be 120,000 lbs. to the square inch, an element which, he thought, ought to be taken into consideration. 2. “On the Physical Conditions under which the Cambrian and Lower Silurian Rocks were probably deposited over the European Area.” By Henry Hicks, Esq., F.G.S The author indicates that the base line of the Cambrian rocks is seen everywhere in Hurope to rest unconformably upon rocks sup- posed to be of the age of the Laurentian of Canada, and that the existence of these Pre-Cambrian rocks indicates that large continental areas existed previous to the deposition of the Cambrian rocks. The central line of the Pre-Cambrian Huropean continent would be shown by a line drawn from 8.W. to N.H. along the south coast of the English Channel, and continued through Holland and Denmark to the Baltic. Its boundaries were mountainous; they are indicated in the north by the Pre-Cambrian ridges in Pembrokeshire, in the Hebrides and Western Highlands, and by the gneissic rocks of Norway, Sweden, and Lapland. The southern line commenced to the south of Spain, passed along Southern Europe, and terminated probably in some elevated plains in Russia. Between these chains the land formed an undulating plain, sloping gradually to the 8.W., its boundary in this direction being probably a line drawn from Spain to a point beyond the British Isles, now marked by the 100-fathom line. ‘The land here facing the Atlantic Ocean would be lowest, and would be first submerged, when the slow and regular depression of the Pre-Cambrian land took place. The author points out that the evidence furnished by the Cam- brian and Lower Silurian deposits of Europe is in accordance with this hypothesis. In England they attain a thickness of 25,000— 30,000 feet; in Sweden not more than 1000 feet; and in Russia they are still thinner, and the earlier deposits seem to be wanting. In Bohemia they occupy an intermediate position as to thickness and order of deposition. 'The author discusses the phenomena presented _by the Welsh deposits of Cambrian and Lower Silurian age, and shows that we have first conglomerates composed of pebbles of the Pre-Cambrian rocks, indicating beach conditions, then ripple-marked sandstones and shallow-water accumulations, and then, after the rather sudden occurrence of a greater depression, finer deposits containing the earliest organisms of this region, which he believes to have immigrated from the deep water of the ocean lying to the S.W. After this the depression was very gradual for a long period, and the deposits were generally formed in shallow water ; then came a greater depression, marked by finer beds containing the second fauna; then a period of gradual subsidence, followed by a more decided depression of probably 1000 feet, the deposits formed in this containing the third or “‘ Menevian”’ fauna. This depression enabled the water to spread over the area between the south of Prussia and Bohemia and Norway and Sweden, there being no evidence of the presence of the first and second faunas over this area. The filling up of this depression led to the deposition of the shallow- 512 Reports and Proceedings. water deposits of the Lingula Flag group, followed by another sudden depression at the commencement of the Tremadoc epoch, which allowed the water to spread freely over the whole Huropean area. The author next discusses the faunas:of the successive epochs, and indicates that these are also in favour of his views. He indicates the probability that the animals, which are all of marine forms, migrated into the Huropean area from some point to the south-west, probably near the equator, where he supposes the earliest types were developed. Both the lower and higher types -of invertebrates ap- pear first in the western areas; and the groups in each case as they first appear are those which biologists now recognize as being most nearly allied, and which may have developed from one common type. The lower invertebrates appear at a very much earlier period than the higher in all the areas. In the Welsh area the higher forms (the Gasteropods, Lamellibranchs, and Cephalopods) come in for the first time in Lower Tremadoc rocks ; and with the exception of the pre- sence of a Gasteropod in rather lower beds in Spain, this is the earliest evidence of these higher forms having reached the Huropean area. At this time, however, no less than five distinct faunas of lower invertebrates had already appeared ; and an enormous period, indicated by the deposition of nearly 15,000 feet of deposits, had elapsed since the first fauna had reached this area. ‘The author points out also that a simliar encroachment of the sea and migration of animals in a north-westerly direction occurred in the North American area at about the same time, the lines indicating the European and American depressions meeting in Mid-Atlantic. 3. “On a Bone-Cave in Creswell Crags.” By the Rev. J. Magens _ Mello, M.A., F.G.S8. In this paper the author describes some fissures.containing numerous bones, situated in Creswell Crags, a ravine bounded by cliffs of Lower Permian limestone, on the north-eastern borders of Derby- shire. These cliffs contain numerous fissures. The principal one described by the author penetrates about 50 yards into the rock and has a wide opening, but is very narrow throughout the greater part of its length. It runs nearly north and south, and inclines slightly - from west to east, from the top downwards. Near the entrance there is a layer of surface soil six or seven inches deep, diminishing to about two inches a few yards in; this contains fragments of modern pottery, etc. A fine flint flake was found in this layer at about four inches from the surface. It is succeeded by a bed of red sand, containing rounded pebbles and rough blocks of Magnesian Limestone, which was cut into to a depth of four to five feet ; it was full of bones, especially at a depth of two and a half or three feet downwards. Most of the long bones lay with their long axis parallel to the sides of the fissure and with their heavier ends foremost. An adjoining cave contained close to the surface some fragments of Roman pottery, together with bones of the common sheep; just below these, from three to four inches deep, were some molars of Ehinoceros tichorhinus, of the reindeer, and numerous chips of flint, Geological Society of London. 513 and also some implements formed from pebbles. The organic re- mains found in the first fissure belong to fourteen mammals at least, besides a bird and a fish. The mammalia are—Man, Lepus timidus, Gulo luscus, Hyena spelea, Ursus, sp., Canis lupus, Canis vulpes, Canis lagopus, Elephas primigenius, Equus caballus, Rhinoceros tichorhinus, Bos urus, Cervus megaceres, Cervus tarandus, Ovis, sp., Arvicola, sp. 4,“ Notes on Haytor Iron Mine.” By Clement Le Neve Foster, Ksq., B.A., D.Sc., F.G.S. The Haytor mine is situated on the eastern borders of Dartmoor, about three-quarters of a mile from the pile of granite rocks from which its name is derived. The iron-ore occurs in the form of magnetite interstratified with altered shales and sandstones of Carboniferous age, which strike about E. 25° S., and dip northwards at an angle of about 30°. Near the iron-ore the rock becomes highly charged with horn- blende, and is sometimes apparently entirely made up of actinolite. Garnets occur in great abundance. The following section is shown in the adit level, viz. :— Carboniferous rock. Tron-ore with partings of rock.... .... .0. co ee» «oe 10 ft. Carhonikerous}re see cc alee Gl ides nese seme cass about 6 ft. Tron-ore with partings of rock ... ... . ... a. .. 14 ft. Carbonierouspeniee cee owt, ths clea meeeaae about 3 ft. Granifesvelnascine toy teat eine sey awn Gee eecap (tech tinea jaes conte Oy kT s Tron-ore... . sag aa Obs A fourth bed, about 3 ft. thick, is seen cropping out about 500 yards N.E. from the others. The granite-vein is intruded, not interbedded. The outcrop of these beds of magnetite may be traced eastwards for a distance of about three-quarters of a mile. The author considers the iron-ore to be simply an altered stratified deposit, and not an igneous trap. 5. “On the Formation of the Polar Ice-cap.”. By J. J. Murphy, Esq., F.G.S. The present paper is intended by the author to supplement a previous one, read before the Society in 1869 (Q. J. G.S. vol. xxv. p. 350), in which he gave reasons for differing from Mr. Croll in thinking that the glacial climate was one of intense cold, and held, on the contrary, that it was one of snowy winters and cold summers, with a small range of temperature.. Mr. Campbell, in a paper read before the Society in 1874, gave the following as the southernmost limits of the Polar ice-cap, viz. :— In Eastern Hurope lat. 56° N.; in Germany 55°; in Britain nearly 50°; in America 389°. This the author considers as strong, but not new evidence against the theory of an ice-cap extending to low latitudes ; the extent of the ice-cap would, of course, not be so wide as that of the limits of glaciation, owing to the floating ice approach- ing nearer the equator. After commenting on Mr. Belt’s remarks made during the discussion of Mr. Campbell’s paper, the author states that he attributes the presence of the boulders found in the valley of the Amazon to icebergs which had drifted further than 514 Reports and Proceedings— usual. The glaciation of the tropics would imply the glaciation of the whole world, which appears no more possible than that the whole world was submerged at one time. The author concludes with some remarks on a recent paper by Mr. A. Tylor. 6. “Notes on the Gasteropoda of the Guelph Formation of Canada.” By Professor H. Alleyne Nicholson, M.D., D.Sc., F.R.S.E., I.G.S. The author notices the occurrence of the Guelph formation as a subdivision of the Niagara series in Canada and the United States, and describes it as consisting everywhere of a cellular, yellowish or cream-coloured dolomitic limestone, of rough texture and crystalline aspect, containing innumerable cavities from which fossils of various kinds have been dissolved out. Most of the fossils still existing in the formation are in the condition of casts. 'The most characteristic forms which have been recognized in it are Pentamerus occidentalis (Hall), various species of Trimerellidee, Megalomus eanadensis (Hall), species of Favosites and Ampleaus, and numerous Gasteropods he- longing chiefly to the genera Murchisonia, Pleurotomaria, Subulites and Holopea. Crinoids and Cystidians and Polyzoa occur abundantly in some localities. In this paper the author describes all the known Gasteropoda of the Guelph formation in Canada, including the following previously described species :—Murchisonia. Loganii (Hall), M. turritiformis (Hall), I. macrospira (Hall), M. bivitiata (Hall), IL longispira (Hall), Jf vitellia (Billings), IZ Hercyna (Billings), Cyclonema ? elevata (Hall), Holopea guelphensis (Billings), H.gracia (Billings), Su- bulites ventricosus (Hall), and Pleurotomaria solarioides (Hall). As new species he describes Wurchisonia Boylei, distinguished from M. turritiformis (Hall) and M. estella (Billings) by its more rapid rate of expansion, its apparently canaliculated suture, and the existence of an angular band a little above the suture; and Holopea ? occi- dentalis, distinguished by its short but elevated spire, its large body- ~ whorl, which becomes almost disjunct at the aperture, its circular aperture and large umbilicus. The upper whorls are convex, but the body-whorl is obtusely angulated at about its upper fourth. Un- certain species of Murchisonia and Pleurotomaria are also indicated. 7. “Description of a New Genus of Tabulate Coral.” By G. J. Hinde, Esq., F.G.S. The coral described by the author as constituting a new genus of Favositide, for which he proposes the name of Spherolites, has a massive, free corallum, consisting of minute, polygonal, closely united corallites, growing in all directions from a central point, forming a spheroidal body, the entire surface of which is occupied by the calices of the corallites. The walls of the corallites are very delicate, with numerous pores; the tabule are incomplete, formed by delicate arched lamella; and there are no septa. From Cheetetes this genus is distinguished by the perforated walls and incomplete arched tabule ; from Favosites it differs in its mode of growth and its in- complete tabule ; and from Michelinia it is separated by the minute- ness of its corallites, and the absence of epitheca and of septal strie. Geological Society of London. 515 The single species, which is named S. Nicholsoni, is from calcareous shale of Lower Helderberg (Ludlow) age, near Dalhous in New Br ae 8. “On the Superficial Geology of the Central Region a North America.” By G. M. Dawson, Hsq., Assoc. R.S.M., Geologist to H.M. North American Boundary Commission. Communicated by Dr. Bigsby, F.R.S., F.G.S. Physical geography of the region.—The region under consideration is that portion of the great tract of prairie of the middle of North America from Mexico to the Arctic Sea, which lies between the 49th and 55th parallels, and extends from the base of the Rocky Mountains to a ridge of Laurentian rocks that runs N.W. from Lake Superior towards the Arctic Seas, and is called by the author the “ Laurentian axis.” This plateau is crossed by two watersheds ; one, starting from the base of the Rocky Mountains at about the 49th parallel, runs due east to the 105th meridian, when it turns to the §8.H., dividing the Red River from the Missouri; the other crosses from the Rocky Mountains to the Laurentian axis near the 55th parallel. The whole region between these two transverse watersheds slopes gra- dually eastward, but is divisible into three prairie steppes or plateaus of different elevations. The lowest includes Lake Winnipeg and the valley of the Red River; its average altitude is 800 ft. The second, or the ‘‘Great Plains,’ properly so called, has an average ele- vation of 1600 ft. The third or highest is from 2500 to 4200 ft. above the sea, and is not so level as the other two. Glacial phenomena of the Laurentian axis.—The neighbourhood of the Lake of the Woods is taken by the author as furnishing an example of the glaciation visible in many parts of the Laurentian axis. This lake is 70 miles long, and has a coast line of 300 or 400 miles. The details of its outline closely follow the character of the rock, spreading out over the schistose and thinly cleavable varieties, and becoming narrow and tortuous where compact dioritic rocks, greenstone, conglomerate, and gneiss prevail. The rocks both on the shores and the islands in the lake are rounded, grooved, and striated. The general direction of the striz is from N.E. to 8.W. Drift Plateau of Northern Minnesota and Eastern Manitoba.—This plateau consists of a great thickness of drift deposits, resting on the gently sloping foot of the Laurentian, and is composed to a depth of 60 feet or more of fine sands and arenaceous clays, with occasional beds of gravel and small boulders, probably reposing throughout on boulder- “clay. The only fossil found was a piece of wood apparently of the common cedar (Thwa occidentalis). The surface of the plateau is strewn with large erratics, derived chiefly from the Laurentian and Huronian to the north; but there are also many of white limestone. The fossils in some of the latter being of Upper Silurian age, the author is inclined to believe, with Dr. Bigsby, that an outcrop of Upper Silurian is concealed by the drift deposits in the Lake of the Woods region. Lowest Prairie Level and Valley of the Red River.—This prairie 516 Reports anid Proceedings— | presents an appearance of perfect horizontality. The soil consists of fine silty deposits, arranged in thin horizontal beds, resting on till or boulder-clay. Stones were exceedingly rare. The western escarpment was terraced and covered with boulders. It is therefore probable that this prairie is the bed of a preglacial lake. The Second Prairie Plateau is thickly covered with drift deposits, which consist in great part of local débris, derived from the under- lying soft formations, mixed with a considerable quantity of trans- ported material, especially in the upper layers. Large erratics are in places abundant; they consist mainly of Laurentian rocks, but Silurian limestone also abounds. The following is the per-centage of the boulders from the different formations present in the drift :— Laurentian 2849, Huronian 9-71, Limestone 54:01, Quartzite Drift 114. The last is derived from the Rocky Mountains, the other three from the Laurentian axis. There are also on the surface of this plateau some remarkable elevated regions, apparently entirely composed of accumulated drift materials. Edge of the Third Prairie Plateau, or the Missouri Coteau, is a mass of glacial débris and. travelled blocks averaging from 30 to 40 miles in breadth, and extending diagonally across the country for a distance of about 800 miles. Third or Highest Plateau.—There is a marked change in. the drift on this plateau, the quarizite drift of the Rocky Mountains pre- ponderating, seldom showing much glaciation. Its general cha- racter may be seen from the following per-centage of its composition :— Laurentian 27-05, Huronian ? Limestone 15°84, Quartzite drift 52-10. Some of the lower parts of this steppe show thick deposits of true till with well-glaciated stones, both from the mountains and the east, and débris from underlying Tertiary beds, all in a hard yellowish sandy matrix. On the higher prairie sloping up to the Rocky Mountains the drift is entirely composed of material derived from them. The Rocky Mountains themselves show abundant traces of glacia- tion. Nearly all the valleys hold remnants of moraines, some of them still very perfect. The harder rocks show the usual rounded forms, but striation was only observed in a single locality, and there coincided with the main direction of the valley. The longer valleys generally terminate in cirques, with almost perpendicular rock-walls, and containing small but deep lakes. State of the interior region of the continent previous to the Glacial Period.—The author considers that previous to the glacial epoch the country was at about its present elevation, and that its main physical features and river-drainage were already outlined. Subaérial de- nudation had been in operation for a vast period of time, and an enormous mass of Tertiary and Cretaceous strata removed. Mode of Glaciation and Formation of the Drift Deposits—The author did not find any evidence rendering the supposition of a great northern ice-cap necessary; but suggests that local glaciers on the Laurentian axis furnished icebergs laden with boulders, which were floated across the then submerged prairies towards the Rocky Mountains. Geological Society of London. 517 9. “On some important Facts connected with the Boulders and Drifts of the Eden Valley, and their bearing on the Theory of a Melting Ice-sheet charged throughout with Rock-fragments.” By D. Mackintosh, Esq., F.G.S. In this paper the main object of the author is to defend generally received opinions, especially as regards the great glacial submergence, in opposition to the theory announced in the Quart. Journ. Geol. Soc. for last February (vol. xxxi. p. 55). He brings forward a number of facts and considerations, founded on repeated observations, to show that the dispersion of Criffell granite-boulders is so inter- woven with that of boulders of porphyry and syenite from the Lake- district as to be incompatible with the theory of transportation by currents of land-ice; and that the limitation of Criffell boulders along the §.H. border of the plain of Cumberland to about 400 feet above the sea-level is inconsistent with the idea of a boulder-charged ice-current 2400 feet in thickness. He likewise calls attention to the interweaving of Criffell with Shapfell granite in the lower part of the Eden Valley at too acute an angle to be satisfactorily explained by upper and under currents of land-ice. He remarks that Mr. Goodchild has not taken into account the dispersion of numerous Shap-granite boulders over ground at least 1300 feet above the sea- level as far south as Milnethorpe. He defends the idea of a special dispersion of surface-blocks of Shap granite, and believes that the limited altitude they have reached on Stainmoor is opposed to the theory of a boulder-charged ice-current 2300 feet in thickness, while an ice-current only 1500 feet in thickness on Stainmoor could not have persisted in carrying the boulders over opposing eminences as far as Bridlington on the Yorkshire coast. The author still further believes that the sudden disappearance of the ice-sheet can be better explained by the encroachment of the sea than by the subaérial melting of the ice. But his main argument against the theory of land-ice “charged throughout with rock-fragments of all sizes” is derived from the purity of the interiors of existing ice-sheets ; and he quotes Professor Wyville Thomson in support of his statements. 10. “Observations on the unequal distribution of Drift on oppo- site sides of the Pennine chain, in the country about the source of the river Calder, with suggestions as to the causes which led to that result, together with some notices on the High-level Drift in the upper part of the Valley of the river Irwell.” By John Aitken, Ksq., F.G.S. The author, in calling attention to the unequal distribution of the drift on the opposite side of the Pennine chain in this district, points out that on the western side of that range an extensive series of drift-deposits is found, spreading over the great plains of Lan- eashire and Cheshire down to the Ivish Sea. It also occurs on the west flanks of the chain at elevations of from 1100 to 1200 feet, thus rising several hundred feet above the watersheds of some of the valleys penetrating that elevated region. On the eastern side, however, there is, with one or two slight exceptions, an entire absence of such accumulations, even in the most sheltered and 518 Reports and Proceedings— favourable situations, for a distance of 12 or 15 miles from the water-parting of the country. This absence of drift on the eastern side might, the author con- siders, be satisfactorily accounted for by supposing that the trans- verse valleys of the chain were, during the glacial epoch, completely blocked up with congealed snow or ice, by which means all com- munications between the opposite sides of the range would be entirely cut off. The southward flow of the ice, which was probably not so thick as to cover the higher portions of the chain, would, on encountering such an obstacle to its progress, be deflected west- wards, and finally debouch into the plains of South Lancashire, and would there deposit on its retreat the débris it contained. 11. “On the Granitoid and Associated Metamorphic Rocks of the Lake-district.”” By J. Clifton Ward, Hsq., M.A., F.G.S. Part I. On the Liquid Cavities in the Quartz-bearing Rocks of the Lake-district. The object of this paper was to examine into the evidence afforded by the liquid cavities of the granitoid rocks of the Lake-district, with reference to the pressure under which these rocks may have consoli- dated. In the first division of the subject the geological relations of the three granitic centres of the district were considered, and it was shown that these several granitic masses probably solidified at depths varying from 14,000 feet to 30,000 feet. The most probable maximum depth for the Skiddaw granite was stated as 30,000 feet ; the maximum for the Eskdale granite 22,000 feet; and for the Shap granite 14,000 feet. These maximum depths were arrived at by estimating the greatest thickness of strata that were ever, at one time, accumulated above the horizon of the top of the Skiddaw slates. The mode of microscopic examination, together with a description of the precautions taken in measuring the relative sizes of the cavities and their contained vacuities, formed the second division of the paper. It was stated that all the measurements used in the calculations were made from cases in which the vacuity mixed freely in the liquid of the cavity, and an approximately perfect case for measurement was defined to be one in which the outline of the liquid cavity was sharply defined all round in one focus, and in which the vacuity moved freely to every part of the cavity wethout going out of focus. Then followed the general results of the examination. Restricting the measurements to such cases as those above mentioned, the results were found to be generally consistent with one another, and with those previously obtained by Mr. Sorby in his examination of other granitic districts. From the fact that the calculated pressure in feet of rock was in all cases greatly in excess of the pressure which could have resulted from the thickness of overlying rocks, it was inferred as probable that these granitic masses were not directly connected with volcanic action, by which the pressure might have been relieved, but that the surplus pressure was spent in the work of elevation and con- tortion of the overlying rocks. Microscopic, combined with field evidence, was thought to indicate that the Shap granite, though mainly formed at a depth similar to Geological Society of London. 519 that at which the Eskdale granite consolidated, was yet itself finally consolidated at a much less depth, the mass having eaten its way upwards at a certain point, and perhaps representing an unsuccessful effort towards the formation of a volcanic centre. The examination showed that the mean of the pressures under which the Lake-district granites probably consolidated was nearly the same as the mean which Mr. Sorby arrived at for those of Cornwall. In conclusion the author stated -that he wished these results to be con- sidered as preliminary only, since the complete investigation would necessarily occupy far more time than was at his disposal; at the same time he ventured to hope that general accuracy was insured, while pointing to the many little-known causes which might affect the conclusions. Part II. On the Eskdale and Shap Granites, with their associated Metamorphic Rocks. The author brought forward evidence in this Paper to prove the possibility of the formation of granite by the extreme metamorphism of volcanic rocks. The passage is shown in the field, and may be observed in a complete series of hand specimens. Frequently, indeed, the actual junction is well marked, but in other cases the transition is gradual; and there occur at some little distance from the main mass, inlying patches of what may. be called Bastard granite. The micro- scopic examination proves the passage from a distinctly fragmentary (ash) to a distinctly crystalline rock, and to granite itself. Also the chemical composition of the altered rocks agrees very closely with that of the granite. Both Eskdale and Shap granite were believed to have been formed mainly from the rocks of the voleanic series by metamorphism at con- siderable depths; but the granite of Shap was thought to be in great measure intrusive amongst those particular beds which are now seen around it. A decided increase in the proportion of phosphoric acid was noted in the volcanic rocks on approaching the granite, and a decrease in carbonic acid. 12. “On the Correlation of the Deposits in Cefn and Pontnewydd Caves, with the Drifts of the neighbourhood.’”’ By D. Mackintosh, Esq., F.G.8. Believing that the time has arrived for making some attempt to correlate cavern-deposits with glacial and interglacial drifts, the author ventures to bring forward the results of a personal examination of the remnants of the deposits in Cefn and Pontnewydd caves, compared with old accounts given by Mr. Joshua Trimmer and others.. He has been led to regard the following as the sequence of deposits before the caves were nearly cleared out (order ascending):—1. Loam with bones and smoothly rounded pebbles, nearly all local (cemented into conglom- erate in Pontnewydd cave). As a few foreign pebbles of felstone have been found in this bed, it could not have been deposited by the adjacent river Elwy before the great glacial submergence; and the author gives reasons for believing that it was not introduced by a freshwater stream from the boulder-clay above in Postglacial times, but that it may possibly represent the middle drift of the plains, and may have been 520 Reports and Proceedings— washed in by the sea during the rise of the land. After emergence, and during a comparatively mild interglacial period, bones of animals may have been introduced by rain through fissures in the roof of the cave, and these may have become partly mixed up with the underlying pebbly deposit. 2. Stalagmite, from less than an inch to two feet in thickness, accumulated during a continuance of favourable conditions (apparently absent in Pontnewydd cave). Bones of animals were again brought in by rain or by hyenas, and were afterwards worked up into the following deposit:—38. Clay, with bones, angular and | subangular fragments of limestone, pebbles of Denbighshire sandstone, felstone, etc. (palecolithic flint-implements and a human tooth in Pontnewydd cave according to Professor T. M‘Kenny Hughes). This clay once filled the Cefn cave nearly to the roof. There are reasons for believing that it was principally introduced through the mouth of the cave, that it is of the same age with the neighbouring upper boulder-clay, and that it is not a freshwater redeposit of that clay. It was probably washed in during a second limited submergence. 4. Loam and coarse sand charged with minute fragments of sea-shells. Portions of this deposit may still be found in the Cefn cave; and it may have been introduced through fissures in the roof by the sea as the land was finally emerging. 13. ‘‘ Geological Notes from. the State of New York.” By T. G. B. Lloyd, Esq., C.H., F.G.S. The substance of this paper comprises notes, accompanied by drawings and sketches of various matters of geological interest which fell under the author’s observation whilst residing some years ago in the State of New York. The different subjects are divided under the following heads :— (1) Groovings and channelings in limestone running across the bed of Black River at Watertown, Jefferson Co. (2) Descriptions of the superficial beds of boulder-clay, sand, and grayel which were exposed to view in the district around the village of Theresa during the construction of the Black River and Morristown railroad. (3) A description, with a general and detailed drawing to scale, of a remarkable ‘‘ Giant’s Kettle’? near Oxbow, in Jefferson Co. It has been excavated out of a mass of Laurentian gneiss, which now forms a precipitous cliff, about 100 feet above the river Oswegatchie. The kettle is 28 feet in depth, with an average width of about 8 or 9 feet. - It presents a striking resemblance in form to some of those occurring near Christiania. (4) An account of some peculiar flower-pot-shaped blocks of sand- stone discovered in a quarry of Potsdam sandstone at the village of Theresa. The quarry is situated upon the summit of a narrow gorge, through which the Indian river passes. The bed-rock is a hard, whitish-coloured sandstone, streaked with oxide of iron, and passes in places into quartzite. The blocks of stone, as extracted by the quarry- men, were shaped like cheeses. One of them measured 2 feet in diameter at the top, and 1 foot 6 inches across the bottom. Their depths varied with the thickness of the beds of rock from which they were extracted. They were coated with a thin crust of oxide of iron. Stee List of Papers Read at the British Association, Bristol. 521 There were no signs of any markings upon them. Prof. James Hall, of Albany, has informed the author that the true nature of the blocks remains doubtful. The author in conclusion refers to a statement in a paper on Niagara by Mr. Belt, F.G.S., published in the Quart. Journal of Science for April, 1875, in which it is stated that the sections described as occur- ring near the Falls are typical of the superficial beds that mantle the whole of the northern part of the State of New York and Ohio and much of Canada. He is unable to find any description of a deposit which bears a near resemblance to the boulder-clay occurring in’ the district around the village of Theresa, in the descriptions of various authors of the superficial deposits of the northern part of the State of New York and Canada. He therefore ventures to remark that no section can be considered as typical-of the whole of the north part of the State of New York which does not recognize the existence of the deposit in question. 14. **On a Vertebrate Fossil from the Gault of Folkestone, which also occurs in the Cambridge Greensand.’ By Prof. H. G. Seeley, F.L.S., F.G.8. The author describes a bone having the general form of an incisor tooth obtained from the Gault of Folkestone by Mr. J. S. Gardner, F.G.S8. The flattened .cylindrical end of a specimen from the Cam- bridge Greensand has been figured as a caudal vertebra of Pterodactylus semus. A microscopic section of the expanded end of a specimen from the Cambridge Greensand exhibits ordinary osseous tissue, showing that the fossil is probably a dermal spine from the tail of a Dinosaur. The Gault specimen is smaller than the examples from Cambridge. IJ.—British AssocIaTION FOR THE ADVANCEMENT OF SCIENCE, Bristot, August 26TH to Septemper Ist, 1875. List oF PapEeRS READ BEFORE SxEcTIoN OC. (GEOLOGY.) President —Dr. Tuomas Wricut, F.R.S.E., F.G.8. The President’s Address. Handel Cossham, F.G.S., Edward Wethered, F.G.S., and Walter Saise, F.G.S., Assoc. R. Sch. Mines.—The Northern End of the Bristol Coal-field. J. MacMuririe, F.G.S.—On certain isolated areas of Mountain Lime- stone at Luckington and Vobster. C. Moore, F.G.S.—On the age of the Durdham Down deposits yielding Thecodontosaurus, &e. W. Pengelly, F.R.S.—Eleventh Report on the Exploration of Kent’s Cavern, Torquay. R. H. Tiddeman, M.A., F.G.S.—Report on the Exploration of the Victoria Cave, Settle. Rev. H. W. Crosskey y, F.G.S.—Third Report on Committee on Erratic Blocks in England and Wales. E. B. Tawney, F.G.S.—On the age of the Cannington Park Lime- stone, and its relation to Coal-measures south of the Mendips. W. W. Stoddart, F.G.S.—On Auriferous Limestone at Walton, near Clevedon. 522 _ Reports and Proceedings— Professor H. A. Nicholson, D.Sc., F.G.8., and C. Lapworth, F.G.S.— On some sections of the Silurian Rocks. Professor T. McK. Hughes, M.A., F.G.S.—Notes on the classifica- tion of the Sedimentary Rocks. Part I.—The Lower Group, up to the top of the Old Red Sandstone. Part I].—The Upper Group, from the top of the Old Red Sandstone to Recent. Henry Hicks, F.G.S.—On some areas where the Cambrian and Silurian Rocks occur as conformable series. J. Rk. Mortimer—On the Distribution of Flint in the Chalk of Yorkshire. H, Willett, F.G.S., and W. Topley, F.G.S.—Third Report on the Sub- Wealden Exploration. Professor E. Hébert—Ondulations de la Craie dans le Nord de la France, et leur existence probable sous le Detroit de Douvres. [Undulations of the Chalk in the North of France, and their probable existence under the Straits of Dover.—Translated to the Section by G. A. Lebour. | D. Mackintosh, F.G.S.—On the Geological meaning of the term “ River-basin,” and the desirability of substituting ‘“‘ Drainage area.” D. Mackintosh, F.G.S.— On the origin of Two Polished and Sharpened Stones from Cefn Cave, North Wales. Professor H. Hull, F.R.S.—Observations on the discovery by Count Abbot Castracane of Diatomacez in the Coal of Lancashire and other places. (See Guor. Mac. 1875, p. 414.) W. Sanders, F.R.S.—On certain large bones in Rheetic beds at Aust- Cliff, near Bristol. Rev. P. B. Brodie, F.G.S.—On the further extension of the Rhetic or Penarth beds in Warwickshire, Leicestershire, Lincolnshire, Nottinghamshire, Yorkshire, and Cumberland, and on the oc- currence of some supposed remains of Labyrinthodon and a new Radiate therein. W. J. Harrison—-On the occurrence of Rheetic beds near Leicester. Dr. Th. Wright, F.R.S.E.—Note on the Reptilian remains from the Dolomitic Conglomerate on Durdham Down. H. Woodward, F.R.S.—Tenth Report on British Fossil Crustacea. H. Woodward, F.R.S.—On the discovery of a Scorpion in British Coal-measures. H. Woodward, F.R.S.—On a new Orthopterous Insect from the English Coal-measures. Dr. W. B. Carpenter, F.R.S.—On the origin of the Red Clay found by the Challenger at great depths in the Ocean. W. H. Baily, F.G.S. — On a new species of Labyrinthodont Amphibia from Jarrow Colliery, Co. Kilkenny. J. Hopkinson, F.G.S.—On the distribution of the Graptolites in the Lower Ludlow Rocks, near Ludlow. Professor H. A. Nicholson, D.Sc.—On Azygograpsus—a new genus of Graptolites from the Skiddaw Slates. J. E. Taylor, F.G.S.—On the Discovery of a Submerged Forest in the Estuary of the Orwell. List of Papers Read at the British Association, Bristol. 523 J. G. Grenfell, WA., #.G.S.—Notes on Carboniferous Encrinites from Clifton and from Lancashire. Rev. J. Brodie—On the Action of Ice in what is usually termed the Glacial Period. Rev. W. S. Symonds, F.G.S.—On Changes of Climate during the Glacial Epoch. D. Mackintosh, F.G.S.—Queries and Remarks relative to existing Ice-action in Greenland and the Alps, compared with former Ice-action in N.W. of England and Wales. Rev. J. Gunn, F.G.8.—On the Influx and Stranding of Icebergs during the so-called Glacial Epoch; and a suggestion of the possible cause of the Oscillation of the Level of Land and Water to which that influx may be due. Dr. OC. Ricketts, F.G.S—The Cause of the Glacial Period with reference to the British Isles. E. Fry—On Moraines as the retaining walls of Lakes. G. H. Kinahan, F.G.S.—The drifting power of Tidal Currents and that of Wind-waves. Rev. J. Brodie—On the action of Ice moved by the Tide. W. A. Traill, U.R.I.A——On a mass of Travertine or Calcareous Tuff called “The Glen Rock,” near Ballycastle, Co. Mayo. Dr. W. B. Carpenter, .R.S.—On the condition of the Sea Bottom of the North Pacific, as shown by the Soundings recently taken by U.S. Steamship Tuscarora. J. Thompson, F.G'.S.—On anew genus of Rugose Corals from the Mountain Limestone of Scotland. EH. Charlesworth, F.G.S.—On the discovery of a Molar of Halitherium and Molar of Hippopotamus associated with other remarkable Fossils in the Red Crag of Suffolk. C. E. De Rance, F.G.S.—Report on the underground Waters in the New Red Sandstone and Permian formations of England. Professor A. S. Herschel and G. A. Lebour, /.G.S.—Report on the conductivity for heat of certain Rocks. Dr. Bryce, F.G.S.—Report on Earthquakes in Scotland. Dr. J. Hector, F.R.S.—On the Geology of New Zealand. Professor A. H. Green, W.A., F.G.S.—Notes on the method of deposition of the Millstone-grit of North Derbyshire and South Yorkshire. G. A. Lebour, F.G.S.—On the limits of the Yoredale series in the North of England. Dr. C. Le Neve Foster, B.A., F.G.S.—Notes on the Deposit of Tin at Park of Mines, St. Columb, Cornwall. W. Topley, F.G.S.—On the Phosphorite Lodes of Estramadura ; and on a deposit of Apatite at Jumilla, Murcia. W. Topley, F.G.S.—Notes on some Wealden Conglomerates, contain- ing large pebbles and rolled Ammonites. Je4p ofessor J. Tennant, F.G.S.—Notes on the South African Diamonds. 024 Correspondence—Prof. Hull, etc. BOULDER-CLAY IN IRELAND. Srtr,—I can assure Mr. Birds that he is perfectly correct in sup- posing that there is an Upper Boulder-clay in Ireland, resting on “Middle Sands and Gravels;” and these again on the Lower Boulder- clay or Till. The general series is precisely similar to that of the North-west of England, to which he refers in his letter in the Grou. Mae. for September last (p. 429). If former sections which I had examined had left any doubt on this question on my mind, it would have been removed on seeing the section of the Post-Pliocene beds laid open at the marble quarries of Kilkenny, shown to me this summer by Mr. Hardman, of the Geological Survey. This and other sections in the district tend to prove that the Upper Boulder- clay occupies a considerable extent of surface in that part of Ireland. As this fine section will probably be described in detail by Mr. Hardman himself, I shall not further allude to it, than to say that it puts out of court any future attempts to call in question the succession of the Drift series as given above. The “ Esker Drift”’ so-called, I consider to be later than the Upper Boulder-clay, and is only a remodelled form of the true Drift-beds. 5, Racuan Roap, Dusuin, 10 Sept. 1875. Epwarp Hutt. MR. BONNEY ON GLACIAL EROSION. Str,—On this subject, in this month’s Number, Mr. Bonney is as full of sound sense as usual. But as regards the widening of upland valleys I wish that I could persuade him that there is no necessity for ‘‘the volume of the stream being formerly greater,” or for “the slow motion of the river from one side of the valley to the other,” and to substitute “atmospheric and rain erosion” for “ fluviatile erosion.” I never heard of what Mr. Goodchild calls ‘the spring theory” for forming cliffs and widening valleys. He indeed con- troverts the theory, in which I most cordially agree with him. But does any one hold it? If so, who? Springs cut channels, but what widens these channels into valleys is atmospheric disintegration and the erosion of rain. For this reason the same valley is always narrow directly as the hardness of the strata and wide directly as its softness. So in rocky strata cliffs and rock ledges will be formed ; in soft strata smooth sloping sides; but if the widening of valleys resulted, as Mr. Goodchild says, from “ mechanical means,” the soft strata should form cliffs and ledges as well as the hard ones. Brookwoop Park, ALRESFORD, GORGE GREENWOOD, Colonel. 15th September, 1875. GEOLOGICAL Survey oF Inpra.—We are glad to be able to an- nounce the promotion of Mr. King to the first grade of this depart- ment, and of Messrs. Hughes and Willson (the latter formerly of the Geological Survey of Ireland) to the second grade. We are also glad to see that Dr. W. Waagen has succeeded to the separate appointment of Palzontologist left vacant by the lamented death of Dr. Stoliczka. With Dr. Waagen and the recent additions to the ~ staff of Mr. R. Lydekker and Dr. O. Feistmantel, the Indian Survey may be congratulated upon its great paleontological strength. Os area THE GEOLOGICAL MAGAZINE. NEW SE RIESSe"DECADE MI VOEL I: No. XI—NOVEMBER, 1875. ORIGIN ADL ARTICLES. ae ee I.—On tHe Former Crimatr or tHe Ponuar Recions.! By Prof. A. E. Norprnsxi61p, Hor. Corr. Geol. Soc. Lond., etc., etc. NUY a few years ago it was looked upon as an article of faith among geologists, that the whole globe was once in a melted incan- descent state, and that the conditions of temperature now prevailing on the surface of the earth have been in process of time produced by the slow gradual cooling of the once fused and glowing mass. It then appeared so natural that, in consequence of the earth’s in- ternal heat, a tropical climate should extend from pole to pole, that no special weight was attached to the evidences of this fact which geology was at that time able to produce. The Dane Giesecke’s and the English Scoresby’s specimens of fossil plants from the east and west cvasts of Greenland, evidencing a warm climate there, attracted so little attention, that neither they, nor the fossil re- mains of Saurians found by the famous Arctic traveller Sir Edward Belcher in the American Polar Archipelago, could be found in the museums to which they had been confided. It was not till geologists had become fully convinced that the gradual transition from the time whena warm climate was supposed to have prevailed over the whole earth and the present time has at least once been interrupted by a period during which the greater part of the Huropean and American continents were covered by mighty glaciers, that the geological theory of climates was taken up with real interest. People began gradually to perceive that, even supposing the earth really to have once been in a state of glowing fusion, the cooling must already at the Cambrian and Silurian epochs have proceeded so far that the quantity of heat which the earth lost by radiation was fully compensated by that which it re- ceived from the other heavenly bodies. It has also been supposed that the cause of the Glacial period—when vast ice mountains scat- tered boulders from Scandinavia over the plains of Northern Germany, and when the Swiss Alps formed the centre of an icy desert similar to the present Greenland—is to be sought for in some trifling changes in the form of the earth’s orbit and the inclination of the Equator, which have taken place,-and continue to take place, periodically after the lapse of thousands or hundreds of thousands of years. The same causes which have once produced the Glacial 1 A Lecture delivered at the Anniversary Meeting of the Royal Swedish Academy of Science, March 31, 1876. DECADE I1.—YOL, II.—NO. XI. o4 526 Prof. Nordenskibld—Fformer Climate of Polar Regions. period have thus happened, not only during this last period nearer to our own time, but also many times before; and there is reason to suppose that they were also then followed by somewhat similar results,—that is to say, that the cold and the warm eras have many times alternated on the surface of the earth. In consequence of this, it has become a matter of the utmost importance to science to obtain by real observation accurate information as to the state of temperature on the earth’s surface during as many of the different geological periods as possible. When in our days a scientific ques- tion is seriously propounded, it is seldom long before it is answered ; and even in the instance before us we have of late years received numerous contributions to geological climatology from lands the geographical situation of which in the neighbourhood of the Pole renders them best fitted to yield information of this kind. The geology of the polar tracts can in two different ways supply us with information concerning the former climate, partly by a com- parison of the fossil animals and plants there found with existing forms that live under certain determinate climatic conditions, partly by an accurate examination of the various strata of different geolo- gical ages, with a view to ascertain whether these present any of the indications which usually distinguish Glacial formations. We now possess fossil remains from the polar regions belonging to almost all the periods into which the geologist has divided the history of the earth. The Silurian fossils which McClintock brought home from the American Polar Archipelago, and the German naturalists from Novaja Semlja, as also some probably Devonian remains of fish found by the Swedish Expeditions on the coasts of Spitzbergen, are, however, too few in number, and belong to forms too far removed from those now living, to furnish any sure information relative to the climate in which they have lived. Immediately after the termination of the Devonian age, an ex- tensive continent seems to have been formed in the polar basin north of Europe, and we still find in Beeren Island and Spitzbergen vast strata of slate, sandstone, and coal, belonging to that period, in which are imbedded abundant remains of a luxuriant vegetation, which, as well as several of the fossil plant-remains brought from the polar regions by the Swedish Expeditions, have been examined and described by Prof Heer of Ztirich. We here certainly meet with forms, vast Sigillaria, Calamites, and species of Lepidodendra, etc., which have no exactly corresponding representatives in the now existing plants. Colossal and luxuriant forms of vegetation, how- ever, indicate a climate highly favourable to vegetable develop- ment. A careful examination of the petrifactions taken from these strata shows also so accurate an agreement with the fossil plants of the same period found in many parts of the Continent of Central Kurope, that we are obliged to conclude that at that time no ap- preciable difference of climate existed on the face of the earth, but that a uniform climate extremely favourable for vegetation—but not on that account necessarily tropical—prevailed from the Equator to the Poles. Prof. Nordenskiéld—Former Climate of Polar Legions. 527 The sand and slate beds here mentioned do not contain any marine petrifactions, whence we may conclude that they have been formed in lakes or other hollows in an extensive polar continent. In Beeren Island and Spitzbergen they are, however, covered by beds of lime- stone and siliceous rock, which form the chief material in Beeren Island, and of several considerable mountains on the southern side of Hinloopen Strait, and the innermost bays of Ice-fjord in Spitzbergen. The manner in which these mountains rise several thousand feet above the surrounding snow desert, their regular form, crowned with vast masses of dark volcanic rock divided into vertical columns, the siliceous strata forming perpendicularly-scarped terraces, and the tendency of the calcareous beds to fall away and form natural arches, give to these mountains the appearance of ruins of colossal ancient fortifications and temples, unequalled in sublime and deso- late magnificence. Here, indeed, we meet with the monumental gravestone of a long-past age. The rock is in fact formed almost entirely of shells of marine mollusca, fragments of Corals and Bryozoa of the age of the Mountain-limestone. We have then here not only a proof that the ancient polar continent sank down again and gave place to a deep polar ocean, but also, in the correspondence of the corals, shells, and other associated organic remains, with those met with in more southerly tracts, an indication that the warm polar climate remained unchanged. The Mountain-limestone period was followed by an era during which the richest coal-beds of England, Belgium, and America were formed, and which has accordingly received the name of the Coal period. A new distribution of land and water had now taken place, continents had again arisen in the polar tracts, in the sandstones and argillaceous strata of which we again find, at Bell-sound, on the western coast of Spitzbergen, fossil plants that bear witness to a rich polar vegetation developed under a warm climate. Among these, however, we miss the species of large-leaved fern so abundant in the coal-beds of more southerly lands, a circumstance which may possibly indicate a certain difference of climate as existing at that epoch, unless, as is more probable, the circumstance is merely the result of the insuffi- ciency of the materials brought from but one single arctic locality. The only relics from the polar regions belonging to the succeeding era, the Triassic, are those of marine animals, amongst which a considerable portion consists of large shell-clad Cephalopoda re- lated to Ammonites, Nautilus, etc., which, judging from the habits of the forms still existing in our time, could assuredly only live in a warm ocean. More certain information relative to the nature of the polar climate at that time is afforded by portions of skeletons of colossal Sauria—one form, Ichthyosaurus polaris, seems to have reached a length of 20 or 380 feet—which, together with vast coprolite beds, are found in great abundance inclosed in the Triassic strata of Ice-fjord, and which among the now existing fauna have their nearest representatives in the crocodiles on the sunny banks of the Nile, or perhaps rather in the marine lizard Amblyrhynchus met with in the Galapagos Isles. That multitudes of these cold- 528 Prof. Nordenskiobld—Lormer Climate of Polar Regions. blooded animals lived at that time in the vicinity of the 80th degree of latitude attests beyond all doubt climatal conditions very different from that of the present day. At the entrance of Ice-fjord and at Mount Agardh, in Stor-fjord, the Triassic strata are covered with marine formations belonging to the immediately subsequent geological era, the Jura period, and, as far as we can judge from the few fossil remains hitherto discovered in these strata, no diminution had as yet taken place in the warmth of the polar chmate. But great changes now came to pass in the portion of the polar basin north of Europe, the ocean being again trans- formed into a continent, which, though shattered and reduced, still exists up to the present time. The upper portion, therefore, of the Jura formation of Spitzbergen does not contain any marine organ- isms, but in the place of them beds of sandstone and slate, with coal-seams and impressions of plants. From the strata belonging to that age met with at Cape Boheman in Ice-fjord, situated between the 78th and 79th degrees of latitude, the Swedish Ex- peditions have brought home numerous impressions of palm-like Cycadez and Conifere, the representative species of which now flourish in the neighbourhood of the tropics. This already leads to the sup- position of a warm climate, which supposition is further confirmed by a comparison with the European fossil flora of the same date, which indicates that the climate of Spitzbergen did not then mate- rially differ from that of Central Europe. — . The Swedish Expeditions have also succeeded in obtaining, partly from Greenland and partly from Spitzbergen, from two separate epochs of the Cretaceous era, extensive collections of fossil plants, lately described by Prof. Heer in the Transactions of the R. Swedish Academy. By this we have been enabled not only to determine the epoch when differences of climate first begin to show themselves on the surface of the earth, but also pretty closely to follow an extremely remarkable change in the appearance of the vegetable world which took place during the course of that period. Within the polar basin we meet with the lowest division of the Cretaceous age on the north side of the Noursoak Peninsula, in North-Western Greenland. The crown of the hills is here com- posed of black, ancient lava-streams and immense beds of volcanic tuff, hardened in process of time into solid rock. Over these volcanic formations now rests a covering of perpetual ice, and beneath them on the sea-shore vast strata of sand are dis- covered, containing inconsiderable Coal-beds, interstratified with clay-beds and a fine-grained argillaceous shale singularly fitted for preserving the impressions of fossils that have been imbedded in it. These plants belong to the lowest portion of the Cretaceous age, and among the collections brought from this spot Heer has succeeded in distinguishing 75 different species, among which are 30 Ferns, 9 Cycadez, and 17 Coniferz. The third part of the Ferns belongs to one genus, Gleichenia, which still flourishes in the neighbourhood of the tropics and warmer parts t=) of the temperate zone, and the same remark holds good of the Prof. Nordenskiold—former Climate of Polar Regions. 529 Cycadex, most of which are referable to the genus Zamia, species of which we meet with within the tropics, as also of the Coniferee, some of which are nearly related to fornis still existing in Florida, Japan, and California. From this Heer draws the conclusion, that in the early part of the Cretaceous period the climate of the now ice-covered (Greenland was somewhat like that which now prevails in Egypt and the Canary Isles. Among the Ferns, Cycadee, and Conifers of Noursoak peninsula were found a few impressions of a species of Poplar, Populus primeva, which formed the only, and at the same time the oldest known representative of the forest vegetation now prevailing in the tem- perate zone. Nevertheless the vegetation of the arctic tracts was already during the Cretaceous period undergoing a complete trans- formation. Evidence of this has been obtained from the same locality, Atanekerdluk, on the south side of the Noursoak peninsula, from which such magnificent remains of arctic vegetation of the Tertiary period had previously been obtained, from strata at a somewhat higher level. Here, out of the talus that has fallen from the lofty fells, some black and tolerably easily crumbling strata of shale pro- trude, among which, on careful inspection, impressions of plants may be discovered belonging to the Cretaceous formation, not to the lower, but the upper portion of it. The vegetation is here quite different. The Ferns and Cycadee have disappeared, and in their place we find deciduous trees and other dicotyledons in astonishing variety, and forms, among which a species of fig may be mentioned, of which not only the leaves, but also the fruit have been obtained in a fossil state; two species of Magnolia, etc. ‘The climate that then prevailed over the whole globe was therefore still warm and luxuriant, even if, at least in the Arctic regions, considerably modified from what it formerly had been, inasmuch as that the flowerless vegetation (which was now beginning to die out), as far as we can judge from its present representatives, the ferns, required a warm humid climate, whereas the new forms, with their luxuriant flowers, which now began to characterize the vegetable world, required, in order to develope all the grandeur of their colours, a clear and sunny sky. The disappearance of sundry tropical and sub-tropical forms, that are met with in the older Cretaceous strata, has led Heer to the conclusion that difference of climate at different latitudes was now beginning to show itself, and he calls attention to the circumstance that this takes place synchronously with the development of the dicotyledonous plants in greater variety. Unhappily, in the Arctic regions no fossil remains belonging to the Eocene age, which immediately succeeded the Cretaceous period, have hitherto been met with, and we are therefore destitute of the actual data necessary for ascertaining its climatic character. But the next following, or Miocene age, places at our disposal abundant materials in the magnificent remains of plants obtained, we may say, from all parts of the polar basin and its vicinity ; from West Green- land by Inglefield, McClintock, Rink, Torell, Whymper, and the Swedish Expeditions; from Hast Greenland by Payer; from Alaska - 5380 Prof. Nordenskiéld—Former Climate of Polar Regions. by Mr. Furnhjelm; from Sagalin by Admiral Furnhjelm ; and from different localities of Spitzbergen by the Swedish Expeditions.’ The spots where remains of this period are found are frequently dis- tinguished by their astonishing abundance of fossil plant-remains. For example, at a place in Spitzbergen which we have called Cape Lyell, after the lately-deceased great English geologist, the rocks on the shore for a distance of several hundred feet form a continuous herbarium, where every stroke of the hammer brings to light an image of the vegetation of a long-past age—when the forest vegetation of these tracts consisted of the swamp-cypress of Texas (Taxodium distichum), of gigantic Sequoias, relations or ancestors of California’s mammoth-tree, of large-leafed birches, limes, oaks, beeches, planes, and even magnolias. The place is situated in about. 77° 385 N. lat., on the south side of the entrance to Bell-sound, on the western coast of Spitzbergen. At the foot of the cliff, on one or two barren heaps of gravel, one may discover shoots of an inch long of the polar willow, sole representative of the present vegetation of the locality. Just off the shore the ocean currents drive icebergs, . which have fallen from the neighbouring glaciers, backwards and forwards, and the crown of the rock itself forms the limit of a mighty glacier, which threatens within a few. years to bury under an icy covering of several hundred feet thickness not only the little vegetation that exists here, and which in the summer weeks is some- times adorned with charming colours, but also the memorials of the ancient glorious age now preserved within its rocks. By a careful examination of the rich materials here accessible, and by a comparison of the petrifactions with those of the same period found in more southerly localities, Heer has shown that already in the Miocene era considerable variety of climate existed on the face of the earth, though even the Pole at that time enjoyed a climate fully comparable with that of Central Europe now. ‘The then Flora of Europe had almost entirely an American character, and there are many reasons for supposing that the continents of Europe and America were at that time united, and bounded on the south by an ocean extending from the Atlantic over the present deserts of Sahara and Central Asia to the Pacific. Between the Miocene and the present eras are two important periods, the Pliocene and the Glacial, which to us are particularly deserving of attention, inasmuch as that during them man, the lord of creation, seems first to have made his appearance. That during the latter of these periods vast masses of ice covered at least all the northern part of Europe is a well-known fact; but concerning the nature of the transition from the glorious climate of the Miocene age to the Glacial period, we possess no knowledge whatever founded on actual observation. Probably at some future time con- tributions towards the solution of this important question may be 1 We may also mention the evidence of an Arctic Miocene Flora obtained by Sir John Richardson from fine indurated clay-beds, associated with Coal-seams, on the Mackenzie River, near Great Bear Lake, from which 17 species of fossil plants haye- been identified by Heer.—KHprr. Grou. Mac. Prof. Nordenshiéld—Former Climate of Polar Regions. 531 found amongst the mountain masses that occupy the peninsula be- tween Ice-fjord and Bell-sound in Spitzbergen, or in some parts of the basalt region of north-western Greenland. In the interior of Ice-fjord and at several other places on the coast of Spitzbergen, one meets with indications either that the polar tracts were less completely covered with ice during the Glacial era than is usually supposed, or that, in conformity with what has been observed in Switzerland, inter-glacial periods have also occurred in the polar regions. In some sand-beds not very much raised above the level of the sea one may in fact find the large shells of a mussel (Mytilus edulis) still living in the waters encircling the Scandinavian coast. It is now no longer found in the sea around Spitzbergen, having been probably rooted out by the ice-masses constantly driven by the ocean currents along the coasts. From what has been already stated, it appears that the animal and vegetable relics found in the polar regions imbedded in strata deposited in widely separated geological eras uniformly testify that a warm climate has in former times prevailed over the whole globe. From Paleontological science no support can be obtained for the assump- tion of a periodical alternation of warm and cold climates on the sur- Jace of the earth. A careful investigation of the structure of the different sedimentary strata leads to the same result. We are now very well acquainted with the origin and nature of the various strata, the substance of which has been supplied by the destructive operation of glaciers on the surrounding and subjacent mountain masses, and we can point out certain marks by which these strata may be distinguished from other non-glacial deposits. In these last, one very rarely meets with any large stone boulders, which have fallen from some neigh- bouring cliff, and been imbedded in sand or clay, either directly, and, if so, close to the place where originally found, or else after having in the spring been moved a greater or less distance by river ice. In glacial formations, on the contrary, as one may gather from the study of the strata in Scandinavia that belong to the glacial period, erratic blocks transported on icebergs to far- distant regions play an important part. Ifa climate similar to that which now prevails in the arctic regions has several times during various geological eras existed in the neighbourhood of the Pole, one has reason to expect that sandstones inclosing large boulders should often be met with in these tracts. But this is by no means the case, though such formations, if they exist on a large scale, could hardly escape observation. The character of the coasts in the Arctic regions is especially favourable to geological investigations. While the valleys are for the most part filled with ice, the sides of the mountains in summer, even in the 80th degree of latitude, and to a height of 1000 or 1500 ft. above the level of the sea, are almost wholly free from snow. Nor are the rocks covered with any amount of vegetation worth mentioning, and, moreover, the sides of the mountains on the shore itself frequently present perpendicular sections, which everywhere 532 H, B. Brady —Fossil Foraminifera of Sumatra. expose their bare surfaces to the investigator. The knowledge of a mountain’s geognostic character, at which one in more southerly countries can only arrive after long and laborious researches, re- moval of soil and the like, is here gained almost at the first glance ; and as we have never scen in Spitzbergen nor in Greenland, in these sections often many miles in jength, and including, one may say, all formations from the Silurian to the Tertiary, any boulders even as large as achild’s head, there is not the smallest probability that strata of any considerable extent, containing boulders, are to be found in the Polar tracts previously to the middle of the Tertiary period. Since, then, both an examination of the geognostic condition, and an investigation of the fossil flora and fauna of the polar lands, show no signs of a Glacial era having existed in those parts be- fore the termination of the Miocene period, we are fully justified in rejecting, on the evidence of actual observation, the hypotheses founded on purely theoretical speculations, which assume the many times repeated alternation of warm and glacial climates between the present time and the earliest geological ages. I].—On some Fosstz ForaAMINIFERA FROM THE West-Coast District, SUMATRA. By Henry B. Brapy, F.R.S8., F.L.8., ete. (PLATES XIII. anp XIV.) OTE.—The Fossils about to be described were sent to Hngland in 1873 and 1874 by Heer R. D. M. Verbeek, Director of the Geological Survey of Sumatra, and are here published by thé authority and with the aid of the Dutch-Indian Government. A general account of the geology of the West-Coast District of Sumatra, by Heer Verbeek, is given in the Gronocican Macazinr for October, 1875, New Series, Vol. II. pp. 477-486. T. Rurert Jonus. The series of fossil Foraminifera, collected by Heer Verbeck in Sumatra, to which the following paper refers, were placed in my hands by my friend Prof. T. Rupert Jones, F.R.S., F.G.S., for ex- amination and description. Doubtful points in connexion with them—for many of the specimens are more or. less obscure—have been determined after joint deliberation, and the views stated throughout have been corroborated by my friend and collaborateur. 1. OprRcvuLtna GRanutosa, Leymerie. PJ. AIII. Figs. 1, a, b, ¢. Operculina granulosa, Leymerie, 1846, Mém. Soc. géol. France, 2 sér. vol. i. Mém., No. 8, p. 359, pl. 18, figs. 12 a, 6, c [Assilina undata, D’'Orbigny, 1826, Ann. Sci. Nat. vii. p. 296, No. 3. Assilina undata, 1850, Prodrome de Paléont. vol. ii. p. 336, No. 684; fide D’Archiac, “‘Descr. Anim. foss. Groupe numm. de V’Inde,” p. 157. ] Amongst Heer Verbeek’s fossil Foraminifera from Sumatra, the Decade II Vol. II Pl. XII. NEW SERIES. Geol.Mag.1875. WWest&Co.anp. Tolivck del et lite ALF Sumatra > de atror Foramuinifer ossil J NEW SERIES Decadell Vol. II. Pl XIV. Geol.Mag.1875. WWest & Co mmr AT. Hollick del et lith. Fossil Foraminifera from Sumatra. H. B. Brady—Lossil Foraminifera of Sumatra. 033 most fully represented excepting Orbitoides, as far as number of specimens goes, is the genus Operculina. ‘The Operculine are in two sets, the more numerous series, containing also the finer examples, from the Coralline Limestone of Nias Island; the smaller one from the West Coast of Sumatra. Of the larger examples, Figs. 1, a, b, ¢, Plate XIII. are fairly representative. They may be assigned without hesitation to Operculina granulosa, Leymerie, a variety differing from the typical O. complanata, Defrance, not only in its more or less granulate or beaded surface, but in the slower and more gradual in- crease in breadth of the spiral band of chambers. The specimens of the less numerous set are smaller in size, and their characters are much less strongly marked. They bear some resemblance to the modification ficured by Leymerie (loc. cit. fig. 11, a, b) under the name O. ammounea ; but there can be little doubt that the differences in minor particulars are dependent on mere external circumstances either of life, or in the process of fossilization ; at any rate there seems no substantial basis for their specific separation. The finer specimens of O. granulosa from Nias Island have a diameter of + inch (4-5 mm.), and consist of about five moderately broad convolutions, the individual chambers being very narrow and numerous. The primordial chamber is minute, as is commonly the case in the Operculine type; but there is considerable thickening of the shell-wall, especially near the centre, shown externally by a more or less prominent umbo. Operculina granulosa is a well-known species occurring in the earlier Tertiary beds of Europe in company with fossil Nummuline. Localities—The precise habitats of these Hastern specimens of Operculina are the Tertiary Limestone of Nias Island, where they are found in company with Corals and Nummulites, and the Marl- sandstone, of an earlier Tertiary age, in the Padang Highlands on the West Coast of Sumatra. 2. NumMULINA VARIOLARIA (Sowerby). PI. XIII. Figs. 2, a, 8, ¢, By. Os Ws Ge Nunmularia variolaria, Sowerby, 1829, Mineral Conchology, vol. vi. p. 76, pl. 838, fig. 3. Nummulites variolaria, D’Archiac et Haime,:18538, Descr. Anim. foss. Groupe numm. de |’Inde, p. 146, pl. 9, figs. 13, a—gq. A set of minute Nummulites (labelled “ small”), of which Figs. 2, a, b, c, are examples, and another series (marked “ middle-sized ’’) represented by Figs. 3, a, b, c, may both be assigned to the same species—N. vartolaria. The smaller ones are about =, inch (1° mm.) in diameter, and consist of about three convolutions, of which the third possesses, on the average, sixteen chambers. The primordial chamber is 54, inch (0°1 mm.) in diameter. The larger specimens average about =; inch (2:0 mm.) in diameter, and have four or more convolutions, the outermost composed of about nineteen segments ; the primordial chamber is of the same size as in the smaller ones. The proportionate thickness is much the same in the two cases, save 4 534 HI. B. Brady—Ffossil Foraminifera of Sumatra. that the larger specimens are often rather umbonate. It will be seen, therefore, that there is no distinction, of even varietal force, to be drawn between the two; and they correspond sufficiently closely with the description and figures of N. variolaria given by MM. D’Archiac and Haime. Itis needless to enter into detailed examina- tion of any species which has been treated by the authors referred to in their exhaustive way, or indeed to do more than observe, in general terms, that the form under consideration is one of the “radiate”? group,! comprising the small and relatively thick modifi- cations of Nummulina planulata, common in the early Tertiaries of Western Hurope. Locality—Coralline Limestone of Nias Island. 0. Nummurina Ramonpt, Defrance. Pl. XIII. Figs. 4, a, 6. Nummulites Ramondi, Defrance, 1825, Dict. des Sci. nat. vol. xxv. p. 224. Nummulites Ramondi, D’Archiac et Haime, 18538, Descript. Anim. foss. Groupe numm. de l’Inde, p. 128, pl. 7, figs. 13-17. To this species may safely be assigned a small number of some- what obscure radiato-striate Nummulites from Nias Island, one of which is represented in Pl. XIII. Figs. 4, a,b. The largest specimen has a diameter of 4inch (3:0 mm.), and is about =, inch (1:2 mm.) in thickness. It has been difficult to arrive at any exact information as to the interior structure of the specimens, as in all of those of which microscopical sections have been attempted, not only the minute anatomy of the shell, but even the septation, was greatly obscured by subcrystalline infiltration. None of those examined had more than about six convolutions, the outermost formed of about fifty chambers—being therefore somewhat smaller than the dimen- sions of N. Ramondi as set down by Messrs. D’Archiac and Haime, that is, so far as the examples sent to us are representative—but in all important characters they correspond fairly with the description and figures of the French monograph. Externally they are radiato- striate; in the horizontal section the spiral wall is much thicker than the septal lines; the number of chambers corresponds suffi- ciently closely, though the number of convolutions is not so great, and the primordial chamber is, as far as can be made out, relatively small. The specimen figured shows considerable want of symmetry in its peripheral aspect, the two sides being of unequal convexity, a rather unusual feature in Nummulina. This form is not far re- moved zoologically from the Bornean specimens which Heer Verbeek has described under the name Num. Pengaronensis,? and which are rightly supposed by him to be near allies of NW. Ramondi; but we find nothing in the material at our command to suggest the necessity of separating the Sumatran examples from the latter species. Few of the Nummulites have a wider distribution than this; from the south-west of France, eastwards through Central Europe, 1 See Ann. Nat. Hist. ser. 3, vol. v. p. 110, and viii. p. 231. 2 Neues Jahrbuch fiir Min., ete., Jahrgang 1871, p. 3, pl. 1, figs. 1, a-x. H.. B. Brady—Vossil Foraminifera of Sumatra. 535 North Africa and Asia; indeed almost wherever the early Tertiary Nummulitic strata appear, N. Ramondi seems to be present. Locality—The Nias Limestone, of late Tertiary age, with Num- mulites and Corals. 4. Nummurtna Ramonpi, var. VERBEEKIANA, nov. Pl. XIII. Figs. 5, a, b, ¢. In the collection of Nummulites are a few examples somewhat smaller than the foregoing, also from the Tertiary limestone of the Island of Nias. In general external characters they are very similar to N. Ramondi, but they differ considerably in interior structure. The best specimen is that figured in Pl. XIII. Fig. 5, a; but the drawing, though accurate up to the magnifying power employed, is a little ambiguous. By the abrasion of the outer lamine in places, an appearance like that of the lobulate segments of Amphistegina is produced; the fact being that the septal lines of some of the inner conyolutions are laid bare near the periphery, and these happen to be set more obliquely than those of the outermost whorl, so that the latter appear in the drawing to be suddenly reflexed at a short distance from the margin. The radiating septal lines, however, are in reality not continuous, as they appear in the figure; and with a higher magnifying power and carefully adjusted light the portions near the periphery—that is, the oblique . or reflexed ends of the radii—-are seen to belong to the penultimate or even an earlier convolution. ‘The horizontal section, Fig. 5 b, is clearly the section of a Nummulite, not of an Amphistegina. The distinctions between this variety and what may be regarded as the typical N. Ramondi consist, firstly, in the smaller number of segments in each convolution, and, secondly, in their greater obliquity and curvature. The largest specimen has a diameter of about ='; inch (2°5 mm.), and is somewhat thick and umbonate. Average examples appear to have from five to six convolutions; the sixth with about twenty-six segments. It has been found impossible to ascertain accurately anything about the primordial chamber, all the central portions of the tests being obscured by the obliterating nature of the mineral infiltration. Under the circumstances we can perhaps scarcely do better than distinguish the Nummulite under notice as a variety, naming it Verbeekiana, after Heer Verbeek. Locality —Coralline Limestone of Nias Island. 5. OrprrorpEs papyracna (Boubée). Pl. XIV. Figs. 1, a, 6, ¢, d. Nummulites papyracea, Boubée, 1882, Bull. Soc. géol. France, vol. i. p. 445. Orbitolites Pratti, Michelin, 1840-1847, Icon. zooph. p. 278, pl. 63, ee Jee Orbitolites Fortisii, D’Archiac, 1850, Hist. Progr. Géol. vol. ii. p- 230.—Mém. Soc. géol. France, 2 sér. vol. v. p. 404, pl. 8, figs. 10-12. 536 EE, B, Brady—Lfossil Foraminifera of Sumatra. Orbitoides papyracea, Giimbel, 1868, Abh. d. II. Cl. Akad. Wissensch. | Miinchen, vol. x. pt. 2, p. 690, pl. 8, fig. 1. The nomenclature of this species, better known to English paleon- tologists as Orbitoides Pratti and O. Fortisii, has been worked out with great minuteness by Dr. Giimbel, and to his paper on the North- Alpine Eocene Foraminifera (op. cit,), from which the above refer- ences are taken, the reader may be directed for its full synonymy. The Sumatran specimens call for but little comment. Their general external appearance is shown in Pl. XIY. Figs. 1, a, b; the nearly median horizontal section is given in Fig. 1 c, and the transverse section in Fig. d. The largest of Heer Verbeek’s examples has a diameter of 75 of an inch (15 mm.), and a thickness, at the centre, of about tinch (3-5 mm.); but most of them are propor- tionately thinner than the above fractions indicate, and as very few of them attain even these dimensions, they may be regarded as somewhat small examples of the species. Figs. a and 6 represent fair average specimens, magnified five diameters; the drawings of internal structure, ¢ and d, are on a higher scale, namely 2C diameters. Locality—Coral-limestone, Padang Highlands, West-Coast District, Sumatra. 6. ORBITOIDES DIsPANSA (Sowerby). Pl. XIV. Figs. 2, a, b, c. Lycophris. dispansus, J. de C. Sowerby, 1886, Trans. Geol. Soc., 2 ser. vol. v. p. 327, pl. 24, figs. 15, 16. Lycophris (Orbitoides) dispansus, Carter, 1853, Journ. Bombay Asiat. Soc., vol. v. p. 126, pl. 2, figs. 238-29. Orbitoides dispansa, D’Arch. et Haime, 1854, Descr. An. foss. Groupe numm. de l’Inde, p. 549. Orbitoides dispansa, Giimbel, 1868, Abh. d. IT. Cl. Akad. Wissensch. Miinchen, vol. x. pt. 2, p. 701, pl. 3, figs. 40-47. A few specimens of a small, thick, lenticular Orbitoides, with tuberculate surface (Pl. XIV. Figs. 2, a, b, c), may with confidence be assigned to O. dispansa, a species best known as one of the impor- tant fossil constituents of the Tertiary rocks of Scinde, and more recently found in the Eocene beds of southern Germany and of Italy. Heer Verbeek’s specimens are small; somewhat less than 4 inch (6 am.) in diameter, and J, inch (2 mm.) in thickness. Many of them have both surfaces not merely granulate, which is a common condition, but studded with large prominent tubercles, as shown in _ the figure. Beyond this they seem to offer no points of peculiarity ; but the specimens altogether present much greater variety of external contour than those of O. papyracea. Localities—Orbitoidal Limestone, Bockit Poangang, Sumatra, and the Marl-rock of Nias Island. 7. ORBITOIDES SuMATRENSIS, sp. nov. Pl. XIV. Figs. 3, a, b, ¢. There are still some two or three little fossils pertaining to the genus Orbitoides, very different in shape and proportionate dimen- sions from either of the foregoing. One of these is represented in Pl. XIV. Figs. 3, a, b. They are sub-globular or only slightly com- H. B, Brady—Ffossil Foraminifera of Sumatra. 537 pressed, one-eighth of an inch (3° mm.) in diameter, and about one- tenth of an inch (2°5 mm.) in thickness. The exterior is rough and granular. Laid horizontally, there is an irregular, partial extension of the periphery, which seems to suggest an abortive disc. It is within the bounds of possibility that these specimens may be the central thick portions of some form like the more umbonate varieties of O. dispansa, but the interior structure does not lend itself to this supposition. The general arrangement of the chamber- lets is shown in Fig. 3 c, which is drawn from a horizontai section near, but not at, the median plane. A transverse section shows the median dise, which does not appear to be quite uniformly central in its position, exceedingly thin in the middle, thickening rapidly towards the circumference, rounded at the margin, and having somewhat the contour, in section, of an hour-glass drawn out a little at the ends. The primordial chamber, as far as can be made out, is very small. Such structural and morphological peculiarities as these do not seem to be in accord with the characters of any published species; and, notwithstanding a certain amount of doubt, in the absence of sufficient material for complete in- vestigation, as to the degree of relationship that may exist between these sub-globular specimens and O. dispansa, we have but little hesitation in concluding that they represent an undescribed form, and have named them accordingly. Locality—Marl-rock of Nias Island, West Coast of Sumatra. 8.. Fusunina princers (Ehrenberg). Pl. XIII. Figs. 6, a-c. Borelis princeps, Whrenb., 1854, Mikrogeologie, pl. xxxvii. figs. x. c, 1-4. See also Monatsberichte d. k. Akad. Berlin, fir 1842, p. 273, and 1848, p. 106. Fusulina princeps, Parker and Jones, 1872, Annals N. Hist. ser. 4, « vol. x. pp. 257 and 260. The genus Fusulina is of extreme interest to both the Geologist and the Zoologist,—to the former on account of its restricted stratigraphical range and from the important part it has played as a rock-builder; to the latter from its isomorphism with two other remarkable genera of Foraminifera, namely Alveolina in the “‘porcellanous,” and Loftusia in the ‘‘arenaceous” series. The specimens sent by Heer Verbeek are of considerable scientific value, giving us the morphological parallel to some of the Alveoline of the Tertiary limestones of Central Europe and Western Asia. The fossils figured by Prof. Ehrenberg under the name Borelis princeps are from the ‘“‘ Hornstone of the Mountain-limestone of the Pinega (Dwina), Archangel.” They are much inferior in point of size to those collected by Heer Verbeek, but otherwise the resem- blance in morphological characters is sufficiently close, and the specific name “ princeps”’ acquires a fresh significance as applied to the Sumatran fossils. The dimensions given in the “ Mikrogeologie ” are 4 of an inch (40 mm.), by about 4 inch (3-0 mm.). Heer Verbeek’s specimens vary considerably in size, the largest being 3, of an inch (11 mm.) long, by 4, in. (10 mm.) broad; the 538 FH, B. Brady—Fossil Foraminifera of Sumatra. smallest 4 in. (6 mm.) long, by 4 in. (4 mm.) broad; but many of the smaller ones are manifestly incomplete, being in reality the central portions of larger specimens, of which the outer whorls have been broken away, the fracture following the course of the spiral lamina. The largest number of convolutions traced in any one transverse section is eleven. In their lateral aspect all the larger examples are broadly elliptical, the conjugate diameter being about one-tenth longer than the transverse. The depressions marking the longitudinal septa are pretty evenly distanced, but the individual boundary-lines are somewhat irregular in their course. The colour of some of the specimens is nearly white, of others dark-grey. Perhaps the most nearly allied variety of Fusulina to that under notice is the F. spherica of Dr. Herrman Abich,' found in the Mountain-limestone of Armenia and Azerbeidjan. JI am indebted to Dr. Abich for examples of this interesting form, which is correctly represented in his published drawing as an oblate or somewhat drum- shaped organism, not prolate or elliptical like the Sumatran specimens. On the other hand, we have a near connexion of F. princeps in Fusulina robusta, described by Dr. Meek? from Californian speci- mens; but the pointed ends of the latter seem to indicate a much closer relationship to the type I cylindrica, with which it is also associated in distribution. Ix speaking of Fusulina as an essentially Carboniferous genus, the stratigraphical term must be taken to include those Upper Carboni- ferous beds termed ‘‘ Permian” by American geologists ; indeed, the very largest recorded examples of the type are those described by Shumard*’ under the name Ff. elongata, some of which are stated to be two inches (5 centim.) in length. They were found in the Permian Limestones of New Mexico and Texas. Locality — Carboniferous Limestone, Padang Highlands, West Coast of Sumatra. EXPLANATION OF THE PLATES. Puate XIII. Fie. 1.—Operculina granulosa, Leymerie. All the figures magnified 8 diameters. a. Lateral aspect. 6. Periphero-lateral aspect. c. Interior, as shown by a split specimen. Fies. 2 and 3.—Nummulina variolaria (Sowerby). All the figs. mag. 10 diam. a. a. Lateral aspect. 0. 6. Periphero-lateral aspect. c.¢. Interior, as shown by split specimens. Fie. 4.—Nummulina Ramondi, Defrance. Both figures magnified 10 diameters. a. Lateral aspect. 6. Periphero-lateral aspect. Pie. 6.—Nwnmulina Ramondi, var. Verbcekiana, nov. a. Lateral aspect. Magnified 10 diameters. b. Horizontal median section, showing septation. Magnified 28 diam. ¢c. Horizontal section near the exterior, showing the somewhat sinuate out- line of the alar extension of the chambers. Magnified 28 diam. Fig. 6.—Lusulina princeps (Ehrenberg). All the figures magnified 3 diam. a. Lateral aspect. 6. End aspect. c. Transverse section, showing septation. . 1 Mém. de l’Acad. Imp. Sci. St.-Pétersbourg, 1859, ser. 6, vol. vii. p. 528, pl. 3, los. 13, a, 3, c. "2 Meek and Gabb, Geol. Survey of California; Paleontology, vol. i. 1864, p- 3, pl. 2, figs. 3, a, b, ¢. 3 Trans. Acad. Sci. St.-Louis, 1858, vol. 1. p. 297. G. A. Lebour—Limits of the Yoredale Rocks. 539 Puate XIV. Fic. 1.—Orbitoides papyracea (Boubée). a. Lateral aspect. Magnified 5 diameters. 6. Periphero-lateral aspect. Ditto. ce. Horizontal median section. Magnified 20 diameters. d. Central transverse section. Ditto. Fic. 2.—Orbitoides dispansa (Sowerby). a. Lateral aspect. Magnified 6 diameters. 6. Periphero-lateral aspect. Ditto. i ce. Central transverse section. Magnified 20 diameters. Fic. 3.—Orbitoides Sumatrensis, sp. nov. a. Lateral aspect. Magnified 6 diameters. 6. Periphero-lateral aspect. Ditto. e. Horizontal section, near the median plane. Magnified 35 diameters. > I1I.—Own tue Limits or tom YoreDALE Serius in THE NortH OF EEnGianp.! By G. A. Lezour, F.G.S. London and Belgium, F.R.G.S., ete. Lecturer on Geological Surveying at the University of Durham College of Physical Science, Newcastle-on-Tyne. HEN a group of beds has well-defined boundaries above and below, and when moreover its paleontological characteristics coincide with its stratigraphical limits, it becomes a boon alike to the field-geologist and to the fossil collector. When, on the other hand, both limits and fossils fail to enable one to follow a group beyond a certain point, the sooner the series as-such is relegated to the limbo of purely-local, convenient, but untrue divisions, the better. I pro- pose to show in this paper that the important group of beds com- monly known as the Yoredale Series in the North-Western parts of Yorkshire is a group of the latter kind, convenient indeed in that district, but quite incapable of being traced much further North either stratigraphically or paleontologically. I cannot find a more concise definition of what is usually meant by the term “Yoredale Series” than that given by my friend Prof. Nicholson.? He says: ‘The Yoredale Series of Phillips, the Upper Limestone or Limestone-shale series of some authors, con- sists of numerous alternating beds of limestone, sandstone, grit, and shale, with a few thin and worthless seams of coal, the whole attaining a thickness of 500 feet, according to Mr. Forster. The two most constant members of the Yoredale Series are the ‘Tyne- bottom Limestone,’ and the ‘Main,’ ‘Great,’ or ‘Twelve-fathom’ Limestone, respectively the lowest and the highest limestones of the group. As regards Cumberland and Westmorland, the Yoredale Series is best studied in Alston Moor, in Teesdale, and along the summit of the Pennine Escarpment; but for its fullest development we must look to the valleys and hills of Yorkshire, where it was originally described by Prof. Phillips, and where it sometimes -attains a thickness of 1000 feet.” Now this set of beds is bounded above by the Millstone-grit, and below by the Scar Limestone 1 Read at the Bristol Meeting of the British Association, Ist September, 1875. 2 Hssay on the Geology of Cumberland and Westmorland, by H. A. Nicholson, D.Sc., F.G.S., etc., London and Manchester, 1868, p. 79. 540 G. A. Lebour—Limits of the Yoredale Locks. Series, from which, however, it is separated by a sheet of basaltic trap well known in the North of England as the Great Whin Sill. It is to this lower limit that I wish to call particular attention. | Granting that no stratigraphical boundary could be more con- venient than one marked by a non-intrusive, continuous, evenly- interbedded mass of trap, especially when we remember that, even in its typical localities, the Scar Limestone Series is (setting fossil evidence aside) only distinguished from the upper group by the thickness of its beds of limestone—granting this, it must yet be obvious that each one of these conditions is essential to the arrange- ment. If the basalt be shown to be intrusive, that is, injected among, and not merely over, hardened beds, if it be discontinuous in any portion of its course, if it shift its horizon to higher or lower portions of the Carboniferous mass, then this trap utterly fails as a natural divisional line. Now in a paper read at the Bradford Meeting of the British Association in 1873! by my friend Mr. W. Topley, F.G.8., and myself, which has yet only been printed in abstract, we showed, I believe quite conclusively even to the late Prof. Phillips, who had formerly upheld the opposite view, that in its career across Nor- thumberland to the North Sea the Great Whin Sill was distinctly and undoubtedly intrusive, that it was occasionally discontinuous, and that it was subject to changes of level so important as in some cases to carry it to a position above that very “ Main” or “Great” Limestone which, as is stated in the quotation above, is one of the highest beds in the Yoredale Series. It is needless to repeat the detailed descriptions by which we established these facts, as the paper will probably before long be published in full; but if any scepticism remain on the subject, I would call attention to a section? which, in the words of one very competent to form an opinion, “satisfactorily clears up even to the most fastidious person the intrusive character of the rock.” ° It is true that the Whin Sill in Durham and along the great Pennine Hscarpment is wonderfully regular, and can, for those portions of its extent, be looked upon as, for all practical purposes, the equivalent of a truly interbedded or contemporaneous trap, although even there the signs of its intrusive nature were sufficient to con- vince so experienced an eye as that of the late Prof. Sedgwick. But surely the mere fact that north of Alston Moor its horizon cannot be depended on for any distance along its outcrop, is sufficient to throw the gravest doubt on the Basaltic sheet’s continued geo- logical horizon to the dip or eastern side. There is no reason to believe that an intrusive sheet of trap in which great and frequent shifts of level in one part of its area have been proved, would lie 1 On the Whin Sill of Northumberland, by W. Topley, F.G.S., and G. A. Lebour, F.G.S. (Abstract in Report of the British Association for 1873, London, 1874, part 2, p. 92). 2 On the ‘Great’ and ‘ Four-Fathom’ Limestones and their associated beds in South Northumberland, by G. A. Lebour, F.G.S., etc., Trans, N. Engl. Inst. of Min. Eng., 1875, vol. xxiv. p. 140, and fig. i. pl. xxxii. 3 Mr. R. Howse, in discussion on above paper, 7id. p. 147. G. A. Lebour—Limits of the Yoredale Rocks. 541 persistently between the same beds in any other part of it, even if the examination of its outcrop in the latter region have revealed no change of horizon. Slight variations of level, however, seem to be admitted by some of the upholders of the interbedded character of the Whin Sill, even south of Northumberland.! | In arguing this point in conversation, I have sometimes been met with the objection that the Great Whin Sill was not really taken as the boundary between the Yoredale Series and the Scar Limestone Series, but that the bed of limestone lying upon it in the Alston District and along the Pennine Escarpment was taken as the bottom Yoredale bed—this limestone being well known in the lead-mining districts as the “‘ Tyne-bottom Limestone ”—without reference to the trap, whose absence or presence had but an accidental connexion with the line of division. I believe that this ingenious way of shuffling out of the difficulty is of quite recent invention—dating, in fact, from the time when the true nature of the Whin Sill was con- clusively shown. That it is so will be made apparent by a glance at the most authoritative geological maps of England which have appeared of late years. In them the Yoredales and the Scar, or Carboniferous Limestone proper, divisions will be found very clearly defined by a continuous red divisional line of Basalt—the Great Whin Sill—without a hint of any other demarcation being sought.’ Again, passages such as the following, which testify similarly to the general acceptance of the trap-sheet as a base-line, might be multi- plied with ease, viz. “‘ Yorrpate Rocxs.—In this series we include all the strata from the Fell-top Limestone inclusive to the Great Whin Sill.”’? My position then, with regard to the Great Whin Sill, is this: that being undoubtedly intrusive and subject to change of level, it is totally unfit to serve as the boundary line between two great divi- sions of the Carboniferous rocks. Setting aside the great trap-sheet therefore, and seeking for a less fickle base for the Yoredale rocks in the North, we have offered us merely a bed of Limestone—the Tyne-bottom Limestone of the Alston miners. This ‘‘T'yne-bottom Limestone” is the tenth calcareous bed men- tioned by Westgarth Forster (in descending order) in his section of the strata of the Alston Moor District. It has no lithological cha- racter to distinguish it from the other limestones, either higher in the Yoredales above it, or in the Scar Series below; its thickness (about 22 feet) is not constant, even over a limited district; its fossils are useless for purposes of identification. Indeed, no bed perhaps in the entire Carboniferous Limestone Series in the North of England is more difficult of identification—certainly none has had 1 Nicholson, op. jam. cit., p. 78. 2 The geological map which accompanies the Coal Commission Report is an exception, although in that map the assumed doubtful lme of boundary between Yoredale and Scar is more out than usual, owing, doubtless, to the general character of the map. 3 A Synopsis of the Geology of Durham and Part of Northumberland, by Richard Howse and J. W. Kirkby, Newcastle-on-Tyne, 1863, p. 22. DECADE II.—YOL. II.—NO XI. 35 042 G. A. Lebour—Limits of the Yoredale Rocks. so many other beds taken for it. The reason of this is simply that, with the rooted belief that the Great Whin Sill wasa regularly inter- bedded trap-flow, whatever caleareous band chanced to be found next above it was instantly supposed to be the Tyne-bottom Lime- stone. ‘This identification was sometimes right and sometimes wrong (more often the latter), and it necessarily led to great confusion re- specting the horizons of the beds above.! In the faulted district which lies to the North of Alston it would be a difficult thing to trace with any certainty a line of boundary depending on an ill- characterized bed such as this ; but in this case the difficulty becomes almost an impossibility if we bring the following considerations to bear upon the subject. It is no part of the object of this paper to describe in detail the beds which form the so-called Yoredale Series in Northumberland ; but it is necessary, for a proper understanding of my argument, that I should refer to a paper in which I have shown that the several beds of limestone which make up the calcareous element of the series in the Alston District increase in number in its northern extension, that not only limestones of average thickness, but also grits, shales, and coals appear, and sometimes disappear, as intercalated beds of greater or less continuity.” The Yoredales, which in the Alston District are about 500 feet thick, in about twenty miles of northerly trend increase to some 2000 feet, only a few of the more marked beds being traceable throughout. Among these the Tyne-bottom Limestone has no place. No one but a Wernerian miner, relying on the golden rule of thumb, could at the end of the twenty miles point out with any degree of certainty the bed which is indeed the “‘Tyne-bottom.” It may be there, or it may have thinned out, as many others have been proved to do.. At any rate, here is no fit base for a great stratigraphical division. In the Pennine Escarpment, however unphilosophical and unnatural the line might be shown to be, it is aconvenient one. Here in mid- Northumberland it has not even that recommendation. No doubt a nearly correct approximate horizon could easily be found marking the level of the Tyne-bottom bed. But what would such an approxi- mate line divide ? Above it, from 1000 to 2000 feet of grits, shales and limestones, and thin coals; below it, a much greater mass of grits, shales, limestones, and thin coals, similar in every respect to the series above. Similar lithologically, similar in the individual thicknesses of its beds (for the thick limestones of the Scar Series have disappeared by this time), and similar in fossils. Of what use can such a divi- sion be? i Nearly all the organisms which it was supposed characterized the Yoredales in Northumberland have now been found in the lower 1 The Scar beds are not supposed to be worth much for lead-mining purposes, and are therefore, with a few striking exceptions, seldom worked into. ? On the “ Little Limestone” and its Accompanying Coal in South Northumber- land, by G. A. Lebour, Trans. N, Engl. Inst. Min. Eng. 1875, vol. xxiv. p. 1, e¢ seg. G. A. Lebour—Limits of the Yoredale Rocks. 543 beds of the Carboniferous Series,’ and the massive calcareous forma- tion which sufficiently distinguishes the Scar Series to the south has" given place in the west of this county to a mere extension below of the Yoredale Series above. Ina sense it would be correct to say that in Northumberland the Yoredale Series is the only part of the Carboniferous Series below the Millstone-grit present, with the ex- ception of the Calciferous Sandstone, or Tuedian, group. But only in a very limited sense would this be true. When Prof. de Koninck, in receiving the Wollaston Gold Medal of the Geological Society in February last, took occasion to state, or rather to imply perhaps, that the faunas of the Carboniferous Limestone Series of the North of England and of Scotland were identical with that of the Calcaire de Visé (the uppermost of his three Belgian divisions),’ he no doubt said so in this limited sense. Paleontologically there is no break in the northernmost part of England between the Sear and the Yoredale Series, but this only means that the circum- stances of life and of deposition were in this region free from the changes which in the south determined those groupings of Carboni- ferous organisms which mark off into clear stages the Carboniferous Limestone as a whole. These northern beds are not the Yoredales alone, increased to an enormous thickness. They are the Yoredales plus the Scar Limestone, rendered indistinguishable by the geographical features of their time. They as truly represent the Tournai and the Dinant as they do the Vise division, although they may be homo- taxeous with the last alone. The life conditions of Visé lasted in Northumberland from the close of the Calciferous or Tuedian age to the time of the Millstone-grit, or possibly to the beginning of the Coal-measure Period. Thus it is that in that part of England the Yoredales, the Scar Series, etc., are mere names without significance. “Tn fact,” as Prof. Ramsay has so well said, “‘ viewed as a whole, the Carboniferous Series consists only of one great formation, pos- sessing different lithological characters in different areas, these having been ruled by circumstances dependent on whether the strata were formed in deep, clear, open seas, or near land, or actually, as in the case of the vegetable matter that forms the coals, on the land itself.’ Since then no Yoredales proper and no Scar Limestones proper can be shown to exist, as such, in the great Carboniferous Limestone Series of Northumberland, and since no comprehensive name has been given to the blending of these two divisions which forms the link between the Yorkshire and the Scottish types of the series, and which is developed to its fullest extent in Northumberland, some special name denoting this series must sooner or later be coined. May I venture to suggest “‘ Bernician Series” as a suitable term 1 Up to the present time, the well-marked foraninifer Saccammina Carter’, Brady, is apparently limited to a bed in the Upper or Yoredale part of the series, viz. the Four-fathom Limestone. 2 Abstract of Proc. of the Geol. Soc. of London, No. 296, p. 2 3 Physical Geology and Geography of Great Britain, by A. C. Ramsay, LL.D., F.R.S., 2nd edition, 1872, p. 76. 544. W. M. Gabb—Notes on West Indian Fossils. for these—the beds which in Northumberland lie between the Tuedian (or better Valentian, Geikie, MS.) Rocks and the Millstone-grit ? The term explains itself, and gives no handle to theoretical mis- application. IV.—Nores on West Inp1an Fosstts. By W. M. Gass, Of the Academy of Natural Sciences, Philadelphia, U.S.A. N my return to civilization, after an absence of nearly three years, I observe in the Gronocican Magazine for 1874, New Series, Decade II. Vol. I., pp. 404 and 433, a paper by Mr. R. J. L. Guppy, of Trinidad, describing new species of fossils from the West Indian Tertiaries, to which is appended a list of the fossils known to him up to that date. Unfortunately Mr. Guppy has overlooked my Memoir on the ‘Geology of Santo Domingo, published in the Transactions of the American Philosophical Society more than a year before the date of his paper. In that paper I nearly doubled the list of known fossils in the West Indian Miocene, basing my de- terminations on a collection of unprecedented magnitude, made during the prosecution of the Geological Survey of the Dominican Republic. Although ignorant of the existence of this paper, Mr. Guppy has been fortunate in not redescribing any of the species contained in it, so far as I can make out, save with the following exceptions : Phos erectus, Guppy, Grou. Mac. Pl. XVI. Fig. 1, is the species described by me under the name of P. Guppyi, in recognition of that gentleman’s extensive labours in the region. I had previously pointed out that the shell described by Sowerby as Conus solidus, and re-named by Mr. Guppy as C. recognitus, is identical with Reeve’s pyriformis. Turritella planigyrata, G.,is common in Santo Domingo, and Mr. Guppy’s description must be amplified so as to cover individuals quite heavily, but always evenly ribbed. I cannot indorse the suggestion of a new generic name for Gouldia, even granting the pre-occupation of the old name among birds. Numerous precedents exist for retaining the old, well-known name ; and a following out of the same idea would create much more con- fusion in nomenclature than it would obviate. I append a list of the fossil corals belonging to the Geological Survey Collection, and recently determined by Count Pourtales. List of Fossil Corals collected by W. M. Gabb, Esq., in Santo Domingo. By L. F. Pourrauss. The following list comprises all the fossil corals collected by Mr. Gabb in Santo Domingo. The greater number are stated to be from the Miocene, a few from the Post-Pliocene, and fewer yet from the Cretaceous. The latter are very much altered by fossilization, while among the former, many are in an excellent state of preservation. The determination is of course based on the valuable papers on West Indian fossil corals, published by Prof. P. M. Duncan, F.R.S., in the Quarterly Journal of the Geological Society. A few forms ap- Prof. Tennant—South African Diamonds. 545 pear to be new, but are not described as new species, partly because the specimens are imperfect, and partly because the living species, with which they could be compared or identified, are still in great confusion, as, for instance, in Dichocenia, a genus in which the species appear to have been needlessly multiplied. Since the publication of Prof. Duncan’s paper two genera, supposed extinct, have been found to be still living in deep water in the West Indies. They are Trocho- cyathus and Antillia. Deep sea-dredging will probably reveal still more: CRETACEOUS: Phylloceenia ? | Flabellum ? Miocene. Placocyathus Barretti, Dunc. Antillia bilobata, Dune. P. costatus, Dune: Astrocenia decaphylla, E. & H. Platytrochus, or Sinilotrochus, spi Meandrina labyrinthiformis, Oken.. Astrohelia vasconiensis, KH. & H. IM. sp. Madrasis decastis, Verrill. Diploria cerebriformis, E..& H. Stylophora afinis, Dunc. Maricina areolata, Khrbg. Assterosmitia exarata, Dune. Orbicella cavernosa, Dana. A. anomala, Dune. O. endothecata, Dune: sp. A. coronata,, Dune. Cyphastrea, sp. Trochosmilia multisinuosa, BK. & H. Plesiastrea ramea, Dune. Dichocenia Stokesi? K. & H. Siderastrea galaxea, E..& H. D. tuberosa, Dune. S. siderea, Blair. Lekiophyllia grandis, Dune. Agaricia agaricites, Lmk.. LES Porites furcata, Lmk. Euph yllit,. Sp.- Poeillopora crassoramosa, Dunc. Post-PLIocENE. Dichocenia,. sp: Colpophyllia gyrosa, KE. & H. Stephanocenia interrupta, E. & H. Orbicella cavernosa, Dana. Meandrina strigosa, Dune. Plesiastrea ramea, Dune. Eusmillia fastigiata, K. & H. O. endothecata, Dune. sp. Manieina areolata, Ehrbg. Porites astreoides, Lmk. V.—Notes on Dramonps FROM THE Care oF Goop Hops.! By Professor Tennant, F.G.S. HE first South African diamond was found in March, 1867, and on examining its physical characters, it was pronounced by Dr. Atherstone to be genuine. When this stone was received in London, it created considerable interest, and also some degree of suspicion, some persons having. asserted that it was brought forward for mer- cenary purposes; letters even appeared in the public papers implying that it was impossible it could have been found near Hope Town. As Dr. W. G. Atherstone, F.G.S., of Graham’s Town (who in March, 1867, examined and pronounced the stone to be a diamond), is now in Bristol, I beg to offer a few general remarks on the Cape diamonds, and also to express in public my thanks to him. The late Mr. Mawe, who wrote on diamonds, and described their mode of occurrence in his Travels in Brazil (London, 1812), often expressed to me his opinion of the probability of their existence in 1 Read before the Geological Section of the British Association at Bristol, Sep- tember Ist, 1875. 546 Prof. Tennant—South African Diamonds. South Africa, and said that if people only knew them in the natural state he felt confident they would be found.! He died in 1829, and I took every opportunity to make the subject known by means of short papers, accompanied by figures showing the ordinary crystal- line form of the diamond. The number and quality of diamonds from the Cape are equal to those from the Brazils, which have chiefly supplied Europe during the last eighty years. About ten per cent. of the Cape diamonds may be classified as of the first quality, fifteen per cent. of the second, twenty per cent. of the third; the remainder, under the name of bort, are employed for cutting diamonds, and for the various economic purposes to which this valuable substance is applied by the glazier, the engineer for ‘drilling rocks, the lapidary, and others. Many diamonds contain specs and cavities ; these are placed in the hands of skilled workmen who are acquainted with the cleavage, and by careful manipulation they are frequently able to remove these blemishes, and so to obtain portions of the gems of the first quality for making small “bril- liants,” ‘‘ roses,” and ‘‘ tables.” The cutting and polishing of diamonds was carried on in London with great success 200 years ago; subsequently it was carried on chiefly in Holland ; but several attempts have been made to re-estab- lish the trade in this country. In 1874 the Turners’ Company offered prizes, in the form of medals and the freedom of the City of London, for the best specimens of diamond-cutting. The Baroness Burdett-Coutts has supplemented this by the addition of money prizes, and has offered to contribute the further sum of £50 for prizes in the year 1876. It is estimated that the value of the diamonds found at the Cape from March, 1867, to the present time, exceeds twelve millions of pounds sterling. I am enabled to exhibit not only a large collection of these diamonds, but also samples of the natural materials found associated with them.? In November, 1873, one of my former students brought me the specimen from South Africa represented in Fig. 1, which in its original state weighed 112 carats; it has since been cut by a London firm of diamond-cutters into the beantiful brilliant repre- sented by Figs 2, 8, and 4, weighing 66 carats. The stone has a delicate yellow tinge, and exceeds in size and brilliancy any diamond in the British Crown. It may be remarked, with regard to this class of gem-cutting, that 200 years since the English diamond-cutters were the most celebrated in the world. The diamond-cutting trade is now coming back to England, and the stone figured above affords a fair sample of what excellent work can now be done here. JI may mention that the stone in its present form is worth £10,000, 1 Prof. Tennant explained that the diamond in its natural state bore considerable resemblance to a piece of gum. 2 Prof. Tennant exhibited a South African diamond in the matrix (consisting chiefly of broken fragments of ehloritie and clay-slates), likewise some interesting photographs of the Diamond-workings in South Africa. G. H. Kinhahan—Nomenclature of the Drift. 047 whilst the value of the models of it, which have been cut by the best lapidaries, is a mere trifle, that in glass costing but 10s., and that in crystal but £2. The rule given by Jeffries and the best autho- rities upon diamonds for ascertaining the value of cut diamonds, is to multiply the square of the weight in carats by eight, and call it pounds, so that this diamond would, according to this computation, be worth 66 x 66 x 8 = £34,848. Fic. 2, Front View. Fig. 3, Side View. Fic. 4, Back View. Fie. 1.—Natural Crystal of a Diamond recently found in South Africa. Fies, 2-4.—Three views of the same stone after having been cut as a brilliant by a London diamond-cutter. VI.—NoMENCLATURE OF THE DRIFT. By G. H. Kryanan, M.R.I.A. ie the short notice on the Drift (Guor. Mac. July, 1875, p. 328) I did not mean specially to condemn Mr. Birds; the paper being intended as a general protest against the loose nomenclature used by former writers and adopted by those of the present day. As to the Irish gravels, they have never been systematically examined or classed. We have different gravels—Ist, under the 25-feet contour-line; 2nd, under the 110-feet contour-line; and 8rd, under the 850-feet contour-line—all more or less containing marine shells. Although these gravels are of distinct ages, yet the fossils collected from them have been lumped together. Then older than the Esker gravels (under the 350-feet contour-line), there are gravels at about the following respective heights—550 feet, 750 feet, and 1200 feet, some of which contain fossils, and although these gravels must be much older than the three groups first named, yet their fossils have been all classed together. I remember hearing my brother, the late Dr. Kinahan, remark that the group of fossils from the gravels at Bohernabreena (about 200 feet) were distinct from the group found in the gravels at Howth and the coast to the north- ward (under 100 feet). Inno place in Ireland have I seen gravels belonging to the first three groups (the third being the so-called 548 Dr. Walter Flight—History of Meteorites. “middle gravels”) under normal glacial drift, although I have found gravels belonging to all the others so situated. In Ireland the resurrectionists have employed very loose evidence to reinstate their “middle gravel,” and from what I have seen in some places in England, very similar evidence has been used there also. After the ice and waters of the different seas disappeared from the face of the country, the latter must have been more or less destitute of a protecting envelope of vegetation ; therefore meteoric abrasion had a maximum denuding power, that formed extensive sheets of a re-arranged drift. These accumulations in low places were thick, but gradually thinned as they ascended heights. This process may be seen going on at the present day in the neighbour- hood. of Swansea, where the sulphurous fumes from the furnaces have destroyed vegetation, while Agassiz mentions the formation of a similar drift in Brazil. This re-arranged drift in places in Ireland has been made to do duty as ‘‘ Upper Boulder-clay,” and I was shown a similar drift in Lancashire as “Upper Boulder-clay.” I am very much afraid that the statement made by the President of Section C. at the late Meeting of the British Association in Bristol is too true; and that there is no one living capable of writing about the Glacial Period, as our knowledge of it and what probably took place during it is very crude. In the County Dublin there are low and high level gravels and drifts containing marine shells; and the various writers on the subject, myself among the number, have put forward more or less vague speculations and theories to account for the difference in their levels; while none of us ever thought of col- lecting the fossils from the different zones, and seeing if they formed similar groups. If the latter was done, I would not be surprised to hear, the groups had more or less different characters, showing the gravels to be of different ages. VII.—A Cuapter In THE History or MurnorirtEs. By Waurer Fuieut, D.Sc., F.G.S., Of the Department of Mineralogy, British Museum. (Continued from page 504.) Found 1861.—Breitenbach, Bohemia.! This remarkable siderolite was found in Bohemia, at a spot not very far distant from the Saxon frontier or indeed from Rittersgriin, in Saxony, where a mass closely resembling it was almost contem- poraneously found. So far back as 1751 at Steinbach, a village about midway between Breitenbach and Rittersgriin, a meteorite in all respects similar was discovered; the three masses are so similar to one another and so dissimilar to any others preserved in collections that there can be little doubt that they belong to the same fall. In 1825 Stromeyer examined a siderolite in which he found 61:8 per cent. of silica; this also appears to have been a member of this 1 N. Story-Maskelyne. Proc. Royal Soc. 1869, xix. 266.—V. von Lang. Sitzber. Ak. Wiss. Wien, 1869, lix. 848. Pogg. Ann. cxxxix. 315.—N. Story-Maskelyne. Phil. Trans. 1871, clxi. 359.—G. vom Rath. Zeit. Deut. Geol. Gesell. Berlin, 1878, xxv. 106. Pogg. Ann, Erganz.-Bd. vi. 337. Jahrb. Mineralogie, 1874, i. 79. Dr. Walter Fhight—History of Meteorites. 549 shower of meteorites, believed by Breithaupt to have been the “Hisenregen”’ which occurred at Whitsuntide, 1164, in Saxony, when a mass of iron fell near the town of Meissen. A polished surface of either of these masses exhibits irregularly formed patches of nickel-iron, the interspaces being partly filled with small patches of iron sulphide, the greater portion of the surface being occupied by a greenish and greyish-brown crystalline magma. After the removal of the two first-mentioned ingredients with mercury chloride, the magma is found to consist of (1) highly crystalline, bright green or greenish-yellow grains; (2) rusty-brown, sometimes nearly black, sometimes also nearly colourless grains of a mineral presenting crystalline features, but on which definite planes are rare; and (38) crystalline grains of chromite. The first of these ingredients is bronzite, the crystallographic characters of which are described in the paper of von Lang, who gives the results of measurements made on nine crystals; these results are mineralogically important as affording for the first time complete data for the crystallography of a rhombic mineral having the formula of enstatite. The elements of the crystal are: a:b:c = 0°87568 : 0°84960 : 1 which give the following among the important angles by calculation: 110,010 = 44 8’ 101,100 = 41° 11’ 011,010 = 40° 16’ Von Lang observed the following faces : 100, 010, 001, 011, 054, 302, 101, 102, 103, 104, 410, 520, 210, 580, 110, 120, 250, 130, 111, 121, 112, 122, 212, 133, 232, 124, 144, 324, 344, 524.1 The most important zonal relations of these faces are shown in the spherical projection appended to his paper. The hardness of this mineral is 6 and the specific gravity 3'200, a number differing but slightly from those determined by Stromeyer and estimated by Rumler in the case of the silicates of the Stembach siderolite. The composition of the bronzite, as determined by analyses made by the new method of distillation already alluded to (page 408) and by fusion with alkaline carbonates, was found to be: I. Il. Mean. Oxygen. Siliciciacid) se, era eo DOOM. 005002): cg 9 0G; 00 ae 20,00 IMaomesiam iin. mee ese: OUr2 IONE rs rolC4 (Omi rscuaro0s04 (Meme rmemlearad. ron protoxidersq seem ou allocO Soin ters pulid;200mete | 13°4:09 Bens mue all 99-899 100-776 100-337 These numbers correspond very closely with the formula (Mg: Fez) SiO,. This bronzite, which occurs in association with nickel-iron, contains only half the amount of iron met with in the bronzite of the Manegaum meteorite (page 403), which stone contains next to no nickel-iron. Rammelsberg? has recently pointed out the fact 1 About the time that von Lang published these results vom Rath measured some crystals of terrestrial bronzite, found in a sanidine bomb from the Laachersee, and arrived: at results which accord very exactly with those of von Lang. (Pogg. Ann., CXXXVili. 529.) 2 ©. Rammelsberg. Pogg. Ann., cxl. 311. Rammelsberg draws attention to the remarkable accordance between the angles of bronzite and olivine, which would explain the fact of G. Rose having regarded the silicate in the siderolites of Ritters- grin and Steinbach as olivine, (See note to page 313.) 550 Dr. Waiter Flight—Mistory of Meteorites. that in Stromeyer’s paper, already alluded to, the specific gravity of the silicate is given = 3:27; and he shows that, although the mineral analysed by Stromeyer contained undecomposed silicate, or more probably asmanite, the ratio of Fe to Mg is the same as in the above analyses. By treating with hydrochloric acid the dark-coloured grains con- stituting the second ingredient of the meteorite and forming about one-third of the mass of the mixed silicates the iron staining them is removed, and they are left in a state of colourless purity. This mineral, to which Maskelyne has given the name asmanite,’ is silicic acid, possessing the specific gravity of quartz after fusion, and crystallising in forms belonging to the orthorhombic system. The grains of asmanite are very minute and much rounded, and, although entirely crystalline, they very rarely present faces offering any chance for a result with the goniometer; from several thousand little grains comprised in some two grammes of material Maskelyne obtained a very few crystals with sufficiently distinct crystallographic features to be available for measurement. He found the parametral ratios of asmanite to be: : B2V3 C0 = Woes gil gr arslHD The angles, as calculated from these data and as found on seven different crystals, are as follow : A. B. C. D. K. F. G. (l00403—=. 219884 1. ss Rie OU 101= 27 46. 27°40’ 27°48 27 46 27°49" 27° 25° 27° 65! 27° 44’ 102= 46 29 46 18 eee 46 31 p00 46 2 103= 57 40 200 ete 57 34 5c10 eee 57 25 57 36 00Ol= 909 0 90 0 owe 90 90 1 QU MOSES 8H) NY) BC a Be 203= 51 42 61 32 102= 43 31 48 34 lL 101= 62 14 62 17 aes 62 14 100,010= 90 0 110= 60 10 ae 60 18. 60 10 oA ae 60 10 110=119 50 110,110=120 20 e203 vA an§ Peal 20V sO 001,011= 73 12 { 010= 90 O Ae Rae 90 0 101,110= 63 53 de ae: 63 54 { TOS sos ee Gy 001,116= 32 28 ea ac 32 56 112= 62 21 ae hc 62 21 223= 68 33 a aps 68 36 110= 90 0 “iy nee 90 0 548,001= 63 52 ss ae 64 0 100= 58 28 did nee 58 30 101= 52 18 oe Me 51 48 The cleavage-plane 001 has a vitreous lustre, that on the planes of the forms 100 and 101, as also of the rounded surface in the zone with them, is usually resinous, recalling the lustre of opal. The 1 Asman is the Sanscrit term, corresponding to the Greek &xpwy, for the thunder- polt of Indra. Dr. Walter Flight—History of Meteorites. 551 faces of the octaid forms are almost invariably rounded. The optical characters confirm the measurements in showing asmanite to be rhombic, the optic axes being very distinct and widely separated ; their apparent angle, as measured in air, is 107° to 107° 30’. The hardness of this mineral is 5:5, and the specific gravity 2°24 ; according to vom Rath 2:247. Of the following analyses, I. and II. are the original analyses given in Maskelyne’s paper, III. are the results of a recent analytical examination by vom Rath : I. il. III. Silverciacidipy ay eeu etn Ace meee O-2LOleeaan 9653 Tron oxide ... ... ... 1°124 a0 | ets vhs ines ses) oon eco BIB F con ) ORDO gag RAGS Magnesia |. ... .. 1°509 ...J eatin 100°641 100°000 99:00 It is not a little curious to find that in his Catalogue of the Vienna Collection Partsch! describes a specimen of the Steinbach meteorite as ‘‘native iron, jagged and hackly, with quartz in grains, and a yellow fluorspar.” ‘The detection by G. Rese of quartz in the oxi- dised crust of the Toluca iron is the only earlier instance recorded of the occurrence of free silica in a meteorite. The solvent action of an aqueous solution of sodium carbonate on asmanite and quartz in powder appears to be uniform. As regards the relation in which the three forms of crystallised silicic acid stand to each other in respect to the mode of their for- mation, vom Rath remarks that while crystals of quartz have in most cases unquestionably separated from aqueous solution, and tridymite, as a characteristic mineral of the druses of volcanic rocks, appears to require the co-operation of vapour for its formation, we have probably in asmanite silicic acid crystallised from a molten mass which has become solid. Crystallised silica has not yet been produced by fusion ; when it is, it will probably have the characters of asmanite. The nickel-iron of this siderolite exhibits figures when etched, and consists of : I. II. Mean. Equivalent Ratios. Ironeesn ce) toe) COs ON ee) LO ORG One nnnOUc4:2 Ol tors) smoea29 INGO, Gon oad SOB acc SRY anc 9-284 ... 0-314 Cobalt iiie-ciucaneen Ugo. lemme 0-195... 0-290 ... 0:°010 COMO? 466 cco WERE) pec trace 100-000 100-000 100-000 The above ratios differ but slightly from Fe: (Ni, Co) = 10: 1. Rube’s examination of the Rittersgriin iron yielded very similar per-centage numbers. The chromite of this siderolite gives angles corresponding to a regular octahedron. 1 P, Partsch. Die Meteoriten im k. k. Hof-Mineralien-Kabinette zu Wien. 1843, Page 99. 552 Dr. Walter Flight—History of Meteorites. Found 1861.—Cranbourne, near Melbourne, Australia. [Lat. 38° 11 §.; Long. 145° 20’ E. ]? This enormous block of meteoric iron, which is a familiar object to those frequenting the British Museum, is, with the exception of the recently found Ovifak irons, preserved at Stockholm and Copen- hagen, the largest meteorite contained in any collection. The minerals composing it have for some time past formed the subject of an investigation, and the results which I have obtained will shortly be published. It will suffice here to state that the Australian, like the Greenland irons, oxidises on exposure to moist air and scales off. These masses differ in that the Ovifak iron yields a rusty-brown coarse powder, apparently without structure; in the débris of the Australian iron, on the other hand, distinct crystals of nickel-iron are to be met with. Though partially converted into oxide and readily broken when handled, they attain after treatment with an excess of hydrogen at a red heat their pristine stability. A num- ber of crystals, apparently tetrahedra, of nickel-iron, large and very perfect, as well as plates of what may possibly be beam-iron and which le, though not immediately, upon them, were reduced by this method: I had the honour of showing a small suite of them at the Soirée of the Royal Society on the 26th May last. Be- tween these two forms lie excessively thin plates of an alloy of iron, much richer in nickel, and to the diminished action of an etching fluid on this more stable alloy I ascribe the development of such thin lines as are seen in the section of the Toluca iron (see Plate IX. p. 311). The descriptions and analyses of these and other minerals will appear in the memoir which I have in preparation. I have now to refer the reader to von Haidinger’s early notices? of the discovery of this block, based for the most part on a report supplied by Neumayer, at that time Director of the Flagstaff Observatory at Melbourne. Two masses of meteoric iron were discovered, and near the larger meteorite Neumayer found a brown ochrey mineral which he regarded as a portion of its oxidised crust. It had but feeble action on the magnet and did not fuse before the blowpipe, but turned black and became magnetic. ‘The hardness is rather less than that of felspar, and the specific gravity = 3°744; the composition, according to a recently published analysis by Haushofer, is: Tnsoluble silicate ... 4] Silicice acid 2°3 Alumina ... 1-5: Tron oxide 71:1 Nickel oxide 31 Lime abe 066 1:8 Phosphoric acid. ... 1-4 Water’ sas Bez 99:0 1 K. Haushofer. Jour. Prakt. Chem., 1869, cvii. 330.—M. Berthelot. Ann. chim. et phys. 18738, xxx. 419. ; 2 W.von Haidinger. Sitzber. Ak. Wiss. Wien, 1861, xliii. 583; xliv. 378 and 465; and 1862, xly. 63. Dr. Walter Flight—History of Meteorites. — 553 The author suggests that more or less rounded masses of nickel- iferous gothite or limonite having a similar origin may probably be met with in the older sedimentary rocks. In continuation of his valuable researches on the native and artificial varieties of carbon,! Berthelot examined a specimen of the graphite-like carbon, which I found among the fragments of metal detached from this iron. His object was to ascertain which variety of carbon it resembled, whether it should be classed with the graphite of pig-iron, native plumbago, the amorphous carbon obtained by treating carbides of iron or manganese with acid, the so-called artificial graphite of the gas-retorts which he had previously shown to be no true graphite, anthracite, or, lastly, the carbonaceous sub- stance found in the remarkable meteorite which fell at Orgueil- (1864, May 14th). The carbon of the Cranbourne meteorite was warmed with nitric acid to remove the iron sulphide, and then digested with fuming nitric acid and chlorate of potash. After two treatments with these powerful oxidising agents, Berthelot obtained a greenish graphitic oxide, identical in every respect with the oxide obtained from the graphite of cast iron, and differing as entirely from the oxidised product which plumbago yields under like conditions. As this meteoric carbon resembles in all respects the variety of this element which has been dissolved in molten iron and separated from the solidified mass after very rapid cooling, Berthelot suggests that its formation and association with the meteoric form of iron sulphide® may be ascribed to the action of sulphide of carbon on incandescent iron, since the carbon of the last-mentioned sulphide by decom- position is also liberated in the graphitic form. The carbon of this meteoric iron owes its present form to exposure to a very high temperature ; it cannot have been produced by the action of iron on carbonic oxide or from carbon once combined with the metal and liberated at ordinary temperatures by the solution of the iron in some reagent; and is still further removed from the other variety of meteoric carbon occurring in the stone of Orgueil. The carbon of the Ovifak iron (see page 120) has likewise been examined by Berthelot. He finds it to differ so completely in its behaviour with oxidising reagents from the carbon of the Australian iron that he does not hesitate to pronounce the conditions under which these two forms of the element were produced to have been essentially distinct. 1M. Berthelot. Ann. de Chim. et de Physique, xix. 405. 2 Wohler and Cloez have found that certain of the carbonaceous meteorites con- tain compounds of carbon, hydrogen, and oxygen, resembling the last residues of organic substances of terrestrial origin. By applying his method of hydrogenation to the carbonaceous matter of the Orgueil meteorite, he succeeded in forming a notable quantity of a hydrocarbon of the series (Con Hon 4 2) comparable with the oils of petroleum. This new analogy between the carbonaceous matter of meteorites and substances of organic origin occurring in the crust of our planet is of great interest. (Compt. rend., xvii. 849.) 3 Troilite in large nodules is abundantly present in this meteoric iron. 554 Dr. Walter Flight—History of Meteorites. Fell 1862.—Victoria West, Cape Colony, S. Africa.! This mass is of interest as belonging to the very small class of meteoric irons the fall of which was witnessed. It is stated to be shaped like a pear, the one end being smooth and rounded, the other and smaller end being jagged in.a manner which indicates the probability of its having been detached from a larger meteorite. In 1870 the mass, which weighed 64 lbs., was sawn in two by order of the authorities of the South African Museum at Cape Town, and the one half further divided for distribution. Tschermak has already shown that the meteorites of Ilimaé (see page 77) and Jewell Hill (see pages 77 and 501) enclose lamellee of troilite, which are situated parallel to the faces of the cube; he now finds this iron furnishes a third example of this structure. The section of the iron is not only traversed by fissures, which were evidently once filled with troilite and in many cases still enclose traces of that mineral, but perfect plates of the sulphide are like- wise observed. As in the former instances, the troilite lamelle lie parallel to the faces of the cube, and are enclosed in a shell of beam- iron (kamacite). The etched figures are very distinct, and nodules of granular troilite are also met with. Dr. L. Smith also directs attention to these fissures, and finds the figures developed by etching to be of that class where the lines are delicate and straight, inclined at a considerable angle to each other, a form common in irons rich in schreibersite. The latter mineral is difused through the iron in masses with straight boundaries, 2 in. to 3 in. long, and 4 in. in breadth, also in much narrower and longer forms, as well as in others which are triangular and arrow-shaped. In a drawing accompanying his paper we have an interesting illustration of the specimen which he examined. In the centre of the section a cavity is seen, 1} in. in the longest and 1 in. in the shortest diameter, the interior of which is also coated with a layer of schreibersite th in. thick; the rest of this cavity is stated to be filled with pyrites. Tn his later paper, however, the nodule is said to consist of the monosulphide, troilite. In the absence of the know- ledge of any test, whether with chemical reagents or with the magnet, having been applied, it appears not improbable that some of the elongated enclosed masses described above as schreibersite may be the lamelle of sulphide which T'schermak observed. The specific gravity of this iron is 7-692, and the composition : Iron = 88°83; Nickel = 10:14; Cobalt = 0°53; Phosphorus = 0:28; Copper = trace. Total = 99°78. Found 1862.—Howard Co., Indiana.’ This mass of meteoric iron, which weighs 4 kilog. and has an irregular elongated oval form, was found in a bed of stiff clay about two et below the surface. It is one of the class of irons which is 1G. Tschermak. Mineralogische Mitthetlungen, 1871, 109.—J. L. Smith. Amer. Jour. Se., 1878, v. 107, and 1874, vu. 394.—See also G.R. aka GEOL. Maa. 1868, v. 531. 2 J, L. Smith. Amer. Jour. Sc., 1874, vii. 391. Dr. Walter Flight—History of Meteorites. 555 only slightly affected by atmospheric agency, freshly cut surfaces retaining their brightness perfectly. The specific gravity of the iron is 7-821 and the composition : Tron =87:02; Nickel = 12-29; Cobalt = 0:65; Phosphorus = 0:02; Copper =trace. Total =99-98. An etched surface does not give the slightest indication of Wid- manstittian figures; their occurrence in short appears to be an excep- tion rather than the rule in the case of irons containing more than 9 or 10 per cent. of iron (see page 80). Dr. L. Smith, while seeking for a satisfactory explanation of the formation of these figures, expresses his belief that we shall not arrive at a satisfactory explanation until our knowledge of the effect of the presence of a minute quantity of foreign substances in iron is better understood. He alludes to the power iron, containing one per cent. or even a less amount of phosphorus, acquires of withstanding the action of acid, as evidenced in vessels used for parting gold and silver. During the crystallization of iron, as of other substances, “there is a tendency to eliminate foreign constituents to the exterior portion of the crystals”: after a blast-furnace, for example, has been chilled and the metal has slowly passed from a plastic to a solid condition, the iron will be found in large crystals containing a very much smaller amount of carbon than is usually the case. If meteoric iron then be rapidly brought to the solid state, we can conceive of such a diffusion of the phosphorus as would give no marked indica- tions in any part of the mass; by slow cooling, however, we might expect a more or less complete elimination of the phosphorus in certain parts representing the spaces between the crystals of the mass. ‘The portions of the iron forming the limits of the crystals become more richly charged with phosphorus,” the homogeneous character of the “iron” is destroyed, and this would render its dif- ferent parts variously susceptible to the action of an etching fluid. The irons of Victoria West, South Africa (see above), and Taze- well Co., which enclose nodules of troilite and schreibersite, con- tain, the former only a trace of sulphur and 0:28 per cent. of phos- phorus, the latter 0-016 per cent. of phosphorus; and in the mass of the Arva iron, which is filled with layers of schreibersite, there remains only 0-019 per cent. of phosphorus. The geologist and mineralogist have noticed such a segregation in a vast number of instances. 1863, March 16th.—Pulsora, N.E. of Rutlam, Indore, in Central India.’ In his descriptive catalogue of the meteorites in the Vienna Collec- tion, which is dated 1st October, 1872, Tschermak describes this stone as chondritic, and as consisting of olivine and bronzite with nickel-iron. It occupies a place between those marked C w (white rock without spherules) and C g (grey rock with light-coloured spherules). The letters Ci 6, affixed to it in the catalogue, denote that it has a brecciated structure like the meteorites of Dacca and St. Mesmin. 1G. Tschermak. Mineralogische Mittheilungen, 1872, 165. 556 Dr. Walter Flight—History of Meteorites. [ 1863. |—South-Eastern Missouri. Shepard describes a small mass of meteoric iron originally weigh- ing about 12 oz. which was found by Prof. Shumard in 1863 in the collection of the old Western Academy of Sciences of St. Louis; the only locality given on the label is “S. EH. Missouri.” Shepard finds it to resemble most closely the irons of Arva and Cocke Co. The specific gravity is 7:015—7:112. The metal encloses so large a quantity of schreibersite that after prolonged treatment with acid that mineral projects in thick laminze from the surface, as mica does from coarse-grained weathered granite. The intermediate areas are not traversed with the delicate lines of the same substance (?) as in the case of other irons. The meteorite has the following com- position : Tron = 92:096; Nickel = 2-604; Schreibersite = 5:000. Total = 99-700. with traces of cobalt, chromium, phosphorus, magnesium, carbon and silicium. Found 1864.—Wairarapa Valley, Province of Wellington, New Zealand. I have to thank Dr. Hector, F.R.S., Director of the Geological Survey of New Zealand, for a short account of the only meteorite which has yet been found in that colony, and which is preserved in the Colonial Museum at Wellington. It isin the form of an irregular six-sided pyramid, 7 inches high and 6 inches across the base; the edges are rounded, and the sides slightly convex and indented with shallow pits. The capacity of the stone is 49 cubic inches, the weight 480 oz., and the specific gravity 3°254; the hardness 5-6. It is strongly magnetic, but exhibits no decided polarity. The surface is of a light rusty brown colour, and is stained with exudations of iron chloride and sulphate. A freshly fractured surface is dark grey, mottled with bright metal-like particles of what may be iron monosulphide. By treatment with copper sulphate, the presence of iron in the form of metal was determined; with hydrochloric acid sulphuretted hydrogen was evolved, sulphur set free, and a large quantity of gelatinous silicic acid separated. The insoluble portion consisting of silica and insoluble silicates constituted 56-0 per cent. of the stone. In the soluble portion the predominating ingredients were iron, amounting to 24-01 per cent. and magnesia along with nickel, manganese and soda; alumina and chromium are not present. These reactions so far indicate in the New Zealand meteorite the presence of olivine and an insoluble silicate, in addition to nickel- iron and what may be troilite or magnetic pyrites. A short notice of this stone is to be found in the Appendix A to the Jurors’ Report of the New Zealand Exhibition of 1865, p. 410. Von Haidinger alludes to the circumstances attending the fall of a meteorite of this date (Sitzber. Ak. Wiss. Wien, lii. 151). 1C. U. Shepard. Amer. Jour. Sc., 1869, xlvii. 283. In the catalogue of the Vienna Collection this iron bears the date 1864. Dr. Walter Flight—History of Meteorites. 557 1865, May 23rd.—Gopalpur, Bagerhaut, Jessore, India.’ In his paper communicated to the Vienna Academy Tschermak gives the history of the fall of this stone,” from which it appears that its descent was unattended by the detonation which usually accompanies the descent of a meteorite. The stone, of which three views are given in Tschermak’s paper, has a greyish brown colour ; when laid on the largest flat surface it has approximately a tra- pezoidal boundary, the upper side being curved and exhibiting pits and striped markings. The front surface (die Brustsezte) is covered with a thin feebly lustrous crust which is finely striped and chan- nelled; thec hannels have a radiate arrangement and converge toa point near which is a smal! deep pit, while not far removed from it is another deeper-lying hollow; all the pit-like depressions are elongated, the extension being more marked the shallower they become and the further they lie from the point of radiation. It will be evident from this that during the transit of the meteorite through the atmosphere this point was in front. (See the Tucson iron, page 499.) The heat generated by the compression of the air melts the surface of the stone, and the attrition of particles of air with the more porous portion of the front surface forms the depressions radiating from the foremost point; the fused drops as fast as formed are driven off by the opposing air and give rise to the fine radiated texture of the crust. The hinder surface has very different characters: it consists of two almost flat faces meeting nearly at right angles and forming sharp edges with the front surface. Along this edge the very distinctive crust of the front surface slightly overlaps the hinder portion, terminating in a well-defined and sometimes fringed border. Here the crust is verrucose, most of the granules consist- ing of fused matter, many enclosing unaltered grains of the meteorite; few follow the radiated arrangement observed in the former case. As regards the structure of the stone of Gopalpur it closely re- _ sembles, in the diminutive size of its chondra, the meteorites of Peeu and Utrecht. They are of three kinds: 1). The most striking have a brownish-grey hue and fibrous fracture, their optical principal sections being parallel and perpendicular to the direction of the fibres ; these appear to be bronzite; 2). The next have a radiate structure, and are built up of larger bar-like transparent crystals, which in one spherule were observed to radiate from two centres ; these are not improbably a felspar; and 3). The last kind of chondra consist of a granular fissured mineral which appears to be olivine. The spherules have the same composition as their matrix, bronzite, olivine, nickel-iron and magnetic pyrites forming the predominating constituents in each case. While the chondra, met with in terrestrial rocks, in perlite, obsidian, pitchstone, in many diorites, are radiate- fibrous, those occurring in meteorites are but rarely so, and in these cases the arrangement of the fibres within the spherule is excentric. Moreover, while the meteoric chondra, as already stated, consist of 1G. Tschermak. Sitzber. Akad. Wiss, Wien, 1872, Ixy. 185. Mineralogische Mittheilungen, 1872, 95.—A. Exner. Mineralogische Mittheilungen, 1872, 41. 2 Proc. Asiat. Soc. Bengal, 1865, 94. DECADE II.—YVOL. II.—NO. XI. 36 508 Dr. Walter Flight—History of Meteorites. the same ingredients as the matrix, and often differ from it only in being more coarsely granular, the chondra of terrestrial rocks are shown by the microscope to be differently constituted from the matrix. Tschermak is of opinion that in the case of the meteorites solid masses have been reduced to powder by mutual attrition, the tougher particles withstanding the action becoming rounded, and that dust and spherules have undergone subsequent segregation. The stone of Gopalpur consists, according to Hxner’s analysis, of : Nickel-iron sac fee 00 500 20°35 Magnetic pyrites ... 200 520 200 4:44 Olivine mean. co = C60 a eee 28 86 Bronzite ... ea one nas obo 35°60 Felspar_... 660 500 ace ses 10°75 Chromite ... j sae Be trace 100-00 The nickel-iron has the following composition : Tron = 90°37; Nickel = 9:11; Cobalt = 0°52. Total 100-00. and the portions separated by acid : S8i0, Al,0, FeO MnO CaO MgO K,O Na,O A. Soluble...... 88°31 0°54 25°72 — 072 3471 — — = 100-00 B. Insoluble... 57°95 519 10°03 0°57 3:04 21°42 9°45 1:35 = 100-00 This, it will be seen, is one of the few meteorites containing a variety of felspar, which in this instance amounts to more than 10 per cent. Tschermak was unable to determine by an examination of microscopic sections whether it was oligoclase. 1865, August 25th.—Sherghotty, near Gya, Berar, India.’ According to Lumpe’s analysis, given below, this meteorite con- sists almost exclusively of silicates, only a trace of metallic iron and a very small amount of sulphur having been met with. It contains : Dilicicsacid Weruitaselie=-) estas Orel ANITA 465. doa. con ona co, , SH) monk provoxide mies yeeecti tess mice ale WIRES, G0 G06 G00 oncom) ILM ee NEAY Bod toads and reco LH Sodas Pe Ue CE eee ae anlage ee tm) S Potash ses Ways Seka ee eal 2Oy7) 100-22 These results show that the Sherghotty stone belongs to the class including the meteorites of Stannern, Juvinas, and Jonzac. The stone examined by Crook in Wohler’s laboratory contained more than nine per cent. of nickel-iron and very little lime, from which it is apparent that what Crook held to be the meteorite of Sherghotty is a specimen of another fall. 1H. Lumpe. WMineralogische Mittheilungen, 1871, 55.—G. Tschermak, Mineral- ogische Mittheilungen, 1871, 56; and 1872, 87; Sitzber. Ak. Wiss. Wien, 1872, lxv. 122; Jahrbuch fiir Mineralogie, 1872, 733.—See also F. Crook. On the Chemical Constitution of the Ensishetm, Mauerkirchen, Sherghotty, and Muddoor Stones. Inaug.-Dissert.) 1868. Gottingen: E. A. Huth. Dr, Walter Flight—fMistory of Meteorites. 559 More recently this meteorite has been submitted to a very complete investigation by Tschermak. He finds a fractured surface to be distinctly granular; the grains are of nearly equal magnitude, and among them the eye readily distinguishes two minerals: one of a light brown colour and with very distinct cleavage, the other trans- parent and with a strong vitreous lustre. Further microscopic and chemical examination revealed the presence of three more ingre- dients : a yellow silicate rarely met with and forming grains, 0-1 mm. across, which exhibit doubly refractive power and appear to crystal- lise in the rhombic system ; they are probably bronzite. Magnetite and magnetic pyrites were likewise present. An augitic mineral, the-one above alluded to, forms the chief mass of the stone; it has a greyish-brown colour, and exhibits double refraction with slight pleochroism. The cleavage and optical cha- racters suggest its classification with diopside. The analytical re- sults given below, however, show that it cannot be regarded as a member of the augite group: SEDO BOG! 65 ond Noda) coo oo | BZA ANOTHEIBS gag G30.) G00. 000 oso. RHE Tron protoxide ... 2. ... ... 29°19 IWTEETVESE. 5G9 baa oss don ono Le) THMN® oo oon cco tn cos) 100-56: These numbers accord with the formula : CaO, 2 MgO, 2 FeO,.5 Si0z.. A mixture of hypersthene and hedenbergite, the former greatly preponderating, possesses such a composition. 'T'schermak finds, however, that the silicate cannot be thus constituted, and he con- siders this augitic constituent of the Sherghotty meteorite to be a chemical compound which has not yet been discovered in our terres- trial rocks. ; The second constituent of this stone occurs more sparsely in transparent colourless granules with vitreous lustre and conchoidal fracture ; they proved to be distorted octahedra. ‘‘ Maskelynite,” as Tschermak has named this mineral, does not doubly refract light, and agrees in point of composition with no known cubic mineral, approaching nearest to a labradorite from Labrador examined some time since by Tschermak. The composition of this mineral is: SHINGG HOG! 455 400 con aco. ooo GPS MNbominar see Meet eve teaels tesautdests COD Lime ae AEs) Fie ess, 2 LRG Soda rel LBNIAT SON tecer ) edeLehaves WOT Rotashtn cae ccsan sce ip eccmeoc ca toed eles 100-0 In comparing maskelynite with labradorite, or suggesting a pos- sible dimorphism of labradorite, the one form triclinic, the other cubic, the fact must not be lost sight of that labradorite already re- presents a mixture of two silicates, anorthite and albite, which sub- stances, it will have to be assumed, are dimorphous and occur as a 560 Notices of Memoirs—J. Hopkinson on Graptolites. mixture in the cubic form. ‘The action of acid on maskelynite pointed to its composite nature, to the possibility of its consisting of an aluminous silicate containing soda which is less readily acted upon than another aluminous silicate containing lime. T'schermak represents the Sherhgotty meteorite as made up of: Total Total Pyroxene. Maskelynite. Magnetite. Composition Composition (Calculated). (Observed), Silicic acid .. 38:21 12°68 — 80°89 50°21 ANiwormines 55/505 OPIS 5°79 — 597 5°90 Tron protoxide 16.93 — — 16°93 17°59 Magnesia... ... 10°43 — — 10°43 10-00 Lime Se dase endgO0 2-60 —. 10:25 10°41 Soda Rske fice 1:14 — 1-14 1:28 Rotash Wis. 9-6) =—— 0:29 — 0:29 0°57 Magnetite” .... —— — 4-50 4:50 4:57 73°40 22°50 4°50 100°40 100°53 Specific gravity... 3°466 2°65 5:0 3°285 3°277 While the Sherghotty stone by its peculiar constitution defies in a way proper classification, it finds a place among the small group of eukritic meteorites, and resembles most closely that of Petersburg (1855, August 5th). Found 1866.—Frankfort, Franklin Co., Kentucky. [Lat. 38° 14 N.; Long. 80° 40’ W. |' This block of meteoric iron, which was found on a hill 8 miles S.W. of Frankfort, was conveyed to a blacksmith’s forge in that town, in order to test its quality as iron. It weighs 24 lbs., has a somewhat globular form and a highly crystalline structure. The specific gravity of this iron is 7-692 and the composition : Tron = 90°58; Nickel = 8°53; Cobalt = 0°36; Phosphorus = 0:05; .Copper, trace. Total = 99-62. (To be concluded in our next Number.) INTO ECstOrnayS) ~~ GaEN | AYALIZHIMEO)ILIay Si, — Paper Read before the British Association at Bristol, August, 1875, Section C. Geology. J.—On tHE DISTRIBUTION OF THE GRAPTOLITES IN THE LOWER Luptow Rocks, near Luptow. By Jonn Hopxinson, F.L.S., YHE author first drew attention to the special interest attaching to the Ludlow Rocks, in connexion with investigations on the vertical distribution of the Graptolites, as being the formation in which they apparently die out. The RuappopHora or true graptolites, which with the CLapopHora or dendroid forms, are found in infinite variety when they first ap- pear in the Arenig rocks, genera the most complex coming in simul- taneously with simpler forms, were stated to be represented in the Lower Ludlow rocks by but a single genus, J/onograptus; and the Cladophora also by one genus only, Ptilograptus. 1 J. L. Smith. Amer. Jour. Se., 1870, xlix. 331. Notices of Memoirs—Daubrée on Native Platinum. 561 A list of the graptolites of the Ludlow rocks given in a former communication to the British Association (1873) was then referred to, and the main conclusions as to the distribution in. these rocks near Ludlow of the species enumerated, arrived at in the course of a few days spent in this neighbourhood before phe opening of the present meeting, were given. It was shown that several species of J/onograptus abound in the lowest beds of the Lower Ludlow; that some of these pass up and afew others come in a little higher in the series, all in soft cal- careous sandy shales; and that when a decided change in the strata takes place, indicating in some places, by more siliceous and gritty beds, comparatively shallow water deposits, and in others, by ex- cessively hard fine-grained limestones, a deeper sea, a decided change in the graptolite fauna occurs, the gritty beds containing in myriads a single new form, Monograptus Leintwardensis, and the indurated limestone alone yielding the few species of Ptilograptus which have yet been detected. onograptus colonus, Barrande, a form first seen in the Llandovery rocks, appeared to be the only species which sur- vived these physical changes, it having alone been seen in the softer beds high in the Lower Ludlow, and passing up: from these into the harder calcareous shales which in some-places immediately underlie the Aymestry Limestone, and again passing up: into this limestone bed, in which it seems finally to disappear. The author concluded by showing the dependence of the fossil fauna and flora of these rocks on the physical conditions of the Lower Ludlow seas, the fossils frequently being only locally dis- tributed, and varying slightly in their horizons according to the _ nature of the sediment deposited, the graptolites especially being influenced by these changes, to which their final extinction, or at least their dispersion from the area under consideration, was con- sidered to have been most probably due. To the list previously given, a single species: only, Monograptus Toemeri, Barrande, occurring in the lowest beds of the Lower Lud- low, is added by these recent researches. 1J].—Own tar Assoctation or THE Native Puatinum OF THE URALS. \ DAUBREH, in an interesting paper read before the Academy of - ¢ Sciences, has shown that Native Platinum, although obtained abundantly in the alluvial deposits of certain regions of the Ural, has been found in a Peridote (Olivine) rock, which is-more or less altered into serpentine, and accompanied with diallage (a ferruginous sahlite, according to M. Des Cloizeaux), and also with chromite, which occurs abundantly, not only in separate grains, but also encrusting the grains of platinum. The platinum, which is here associated with chromate of iron, appears to be distinguished from the platinum of other deposits by the large proportion of metallic iron with which it is alloyed. It appears that platinum very rich in iron, and endowed with magnetic polarity, has not been found—at least, at present— save in company with chromate of iron.—‘‘ Comptes Rendus,” t. 1xxx. —March, 1874.—J. M. 1 See Grou, Mag. Vol. X. p. 520, 562 Reviews— Geological Survey of Victoria. Apel VG E del WAS I.—GeroLocicaL SuRvEY oF Victoria, No. 2. 1. Report of Progress. By R. B. Smyth. Melbourne (no date). 2. Prodromus of the Paleontology of Victoria. By Fred. McCoy. Decades I. and II.. Melbourne, 1874-75. 3. Observations on New Vegetable Fossils of the Auriferous Drifts. By Baron F. von Mueller. Melbourne, 1874. E have already noticed the first report of the Geological Survey of Victoria (Guox. Mac. 1874, Decade II, Vol. I. p. 416), and the works above cited sufficiently indicate the satisfactory progress that is being made by the Survey under the direction of Mr. R. Brough Smyth and his able colleagues; while the determination of the animal and vegetable fossil remains could not be placed in better hands than those of Prof. McCoy and Baron Mueller, whose contri- butions are not only of importance to the Colony, but of equal in- terest to Huropean geologists. Mr. Smyth’s Report is both suggestive and useful, as it embodies the general results of the explorations of the officers of the Survey during the past year, and whose detailed reports are given in the memoir. From this it appears that the surveying and mapping of the several areas referred to in the last Report are proceeding satis- factorily. The map of the Ballarat gold-field, embracing an area of 160 square miles, with illustrative sections and copious notes, is printed and published. The geological sketch-map of Cape Otway district, comprising an area of about 690 square miles, is ready for issue; and a similar map of South-Western Gippsland will shortly be completed by Mr. Murray, including an area of 8500 miles—a work of time and labour, the country in many parts being so densely wooded as to render the passage difficult. Satisfactory progress has been made in the survey of the area including the gold-fields of Stawell by Mr. Taylor, and also of the . Ararat gold-fields by Mr. Krausé, who gives some interesting geolo- gical notes as to the conditions under which the various gold-drifts and associated volcanic rocks were accumulated. The geological map and sections of part of the Mitchell River division of the mining district of Gippsland have been prepared by Mr. A. Howitt, whose notes-on the geology of this and the Ovens district (pp. 59-82) are important. The report of Messrs. Htheridge, Junr., and Murray on the country intersected by the Durham lead is of much interest. In this district the Lower Silurian is the bed rock, covered in some places (the south-westerly portion) by Miocene strata, which are non-auriferous ; in others, the Older Pliocene sands and gravels repose on the upturned surface of the Silurian, and are succeeded by deposits containing gold due to fluviatile denudation, and referred to the Lower Newer Pliocene ; this river deposit forming the “‘ deep lead” became partially covered by a lava-stream. Denudation again set in, forming another lead, and covered by a second flow of lava classed as the Middle Newer Pliocene. A series of volcanic eruptions Reviews— Geological Survey of Victoria. 563 followed more or less contemporaneous, covering up nearly the whole surface of the country. Again denudation set in, scooping out the river-channels of the present period, and leaving along their courses, deposits of gravel and clay referred to the Upper Newer Pliocene. These Reports, with their respective fine geological maps and sec- tions, a map of the distribution of the forest trees, and the geological sketch-map of Victoria, are highly creditable to the Mining Depart- ment, and must materially assist and advance the mining industry of the colony. For as the Report states, “In our quartz-veins we have inexhaustible sources of wealth; and enterprise, skill and economy will assuredly, if mining industry be not checked, place Victoria, as regards vein mining, far in advance of all other countries. The area of auriferous ground, but not in all parts con- taining gold in such quantities as to remunerate the miner, is not less than forty thousand square miles. The ores of iron—micaceous iron ore and brown hematite—are widely distributed, and at no - distant period the colony should be enabled to supply its own wants, and there is a reasonable prospect of a large return from at least those districts in which tin, copper, antimony, iron, and lignite are found, the latter occurring in beds of considerable thickness and excellent quality at Lallal and other localities.” The Decades prepared by Prof. McCoy are intended in the first place to give figures and descriptions of the more characteristic fossils of each formation of which good specimens exist in the National Collection, and in future to illustrate the fossil collections made in the course of the Geological Survey of the Colony. The present numbers include detailed descriptions of many interesting fossils,—of Plants, Mammals, Fishes, Mollusca, Starfish, and Grap- tolites, the species of Graptolites from the Victorian Gold-field slates being similar to those occurring in the Lower Silurian or Cambrian rocks of Bohemia, Britain, Sweden, and America, showing a world- wide distribution of these species in the old geological time. Baron von Mueller’s observations on the new vegetable fossils are singularly " interesting, as indicating the vegetation of the period when the older auriferous drifts were deposited; they were noticed in a com- munication to the Geological Society (Grou. Mac. Vol. VIL. p. 390, 1870), but are now fully illustrated in ten lithograms, with detailed descriptions and comparisons of their affinities. They were chiefly obtained from the deep drifts of the older Pliocene formation of Haddon, etc., Victoria, but have recently been found elsewhere, and thus, as Baron Mueller remarks, “the discovery of these remains in a far distant tract of country in New South Wales is not without con- siderable interest, inasmuch as thereby now is shown, that the pristine forests which have left us those vestiges were of wide geographical _ extent.” As far as the Tertiary flora has been examined, there appear to be three periods in which the plants of the lowlands of Victoria were certainly in all respects different. First, the present period, characterized by an abundance of myrtaceous plants; secondly, the period of the deep leads, when the plants were of a tropical and 564 Reviews—The Culm Flora of Moravian Silesia. sub-tropical character; and thirdly, the period of the Lower Upper Pliocene Tertiaries, when lauraceous plants, etce., were existing. (Report, p. 28.) In conclusion, we agree with Mr. Brough Smyth that “it is impossible to conduct a geological survey without the aid of the paleontologist: and such aid, to be of the highest use and value, necessarily requires that all the fossils should be figured and correctly described.” J. M. IJ.—Tne Cutm-Fiora or tHE Morayian-SILestan Roo¥rinc-SLAtTEs. Die Culm-Flora des Mihrisch-Schlesischen Dachschiefers. By D. Srur, pp. 106, with 17 plates. Being No. 1. of vol. viii. of the Abhandlungen der K. K. Geologischen Reichsanstalt. Vienna, 1875. Meee. important memoir throws much light upon a point in the geology of Central Europe which until recently was almost a blank as far as accurate knowledge was concerned. As late as 1859 Ferd. Roemer described the great rock-series whence the fossil plants so splendidly illustrated in the plates before us were derived, as “a shapeless inarticulate mass,” in which no organism had up to that time been detected: That this series consisted of slate and sandstone, and that it lay conformably upon a far-stretching “ grauwacke” forma- tion, which in its turn rested immediately upon the old crystalline rocks of the Sudetic Mountains and upon the flanks of the “ Briinn- Blansko” Syenite range, thus covering a considerable portion of . Moravia and Silesia (Austrian), was about all that was known re- specting it. In 1860 Roemer himself wrung the first secret from these beds by discovering in them a locality for Posidonomya Becheri. From that date progress was made through the labours of Roemer, H. Wolf, Halfar, von Ettingshausen, von Hochstetter, and especially of Herr Max Machanek, the manager of slate quarries in the district, to whose zeal in collecting a large proportion of the species de- scribed by Prof. Stur is due. It was found that here were Carbon- iferous rocks lying upon Devonian beds, from which they were quite . undistinguishable except palzeontologically, and that further these Carboniferous roofing-slates and grits could be referred to the Posi- - donomya-schiefer or Culm-formation of Nassau and Western Westpha- lia. The divisions now recognized in the Culm of Moravia and Silesia are three in number, and are characterized as follows: 1. The westernmost and lowest zone, which lies directly upon the Devonian series, and comprises the two older varieties of roofing- slate. It is from 8000 to 4000 fathoms (Klafter) thick, and consists of sandstones, slates (Klotzschiefer), and yellowish fine-grained con- glomerates yielding good building stone. 2. The middle zone, 4000 to 5000 fathoms thick, is composed of similar rocks to the last, but the enclosed slates are of the thin-split- ting kind known as Blattelschiefer. 3. The upper zone, also about 5000 fathoms thick, is the least studied of the series, and is distinguished by a fine deep blackish- blue Blattelschiefer. Oorrespondence—Mr. J. G. Goodchild. 565 The fossils hitherto found in these divisions are thus distributed : Zones. Zones 123 ’ bi Fauna. i (ee al Friora—continued. =| Phillipsia latispinosa, Sandb. x Sph. Hauert, Star. secon 2 EETUMS Dea scten creer rere x Sph. Kiowitzensis, Stur. .......... INCREAS So cos cecctceeeesceerteteth E002 x Rhodea filifera, Stur. ...... 8 Goniatites prior, StUL........0 x Rh. Machaneki, Ett. sp. . = G. Machaneki, Star. esse x Rh. Hochstettert, Stuy... x G@. sphericus, de Haan. .......... x Rh. giganted, Star. sees 2 G. ef: discus, A. Roem. .......... x Rh. patentissima, tt. sp. ..... 8 G. mixolobus, PALL. «0... ccc x Rh. Moravica, Ett. sp.ecec x Oyrtoceras Machaneki, Stuv..... x Rh. Goepperti, Htt. spi... x C. rugosumd, BVCM. oc... x Ca: diopteris frondosa, Goepp. Gonyoiceras — SRW UJORLE, | |) |) ||) cxecoerccccecnnteo eniccereptanaceceectocncpont 24 SS FLUID a Aten Le sakes x ¢. arias Kitt. sp. ..... x Orthoceras cf. scalare, Goldf. x Neuropteris antecedens, Stur..... % O. striolatum, H. v. M. ......... Ke Archeopteris Tschermaki, O. costellatum, A. Roem........... XK UU ene enemies xe Euomphalus Sp. crrsesseeseereereeren x A. Dawsoni, Stur. ....... xs Posidonomya Bechert, Br. ..... x | x A. dissecta, Goepp. sp... aS aS TGLOCENAINUS SP) e.neeseeseccsesssesesssese x Zale, UTA (SNAUSES cctenccomtbcees:taccocecocee 2 Pecten subspinulosus, Sandb..... x A. pachyrhachis, Goepp. sp. % Js JEOAING Py WSN errrerrenctoreerereeren x ee tenuifolius, Goepp. IDS pin aah ete eee ae Raia SLT 'Spieseten te Ure ES Guemens B Lophocrinus speciosus, H.v. M. x Hi, antiquus, Ett. sp. x Nemertites Sudeticus, Roem...... Xe Bx A. Machaneki, Star. ccc us Crossopodia Moravica, Stuv...... x | Cycadopteris antiqua, Stu. ..... BS Tenens ieee pee (Goepp. MS.) Drepanophycus Machaneki, Rhacopteris paniculifera, Stur. = SS UU ee ee te reeset no x Rh. Machaneki, Star. wc me Equisetites cf. mirabilis, Stur. | x Rh. flabellifera, Star... = Archeocalamites radiatus, Rh. transitionis, (Ett.) Stuv..... xs SGU eee eee eek a X/X|x| Stigmaria inequalis, Goepp..... | *|* Thyrsopteris schistorum, Stur. x Lepidodendron Veltheimianum, Sphenopteris foliolata, Stuv..... x StermbsseeiMemeleub eens 2s Sph. distans, Sternd. 1... | 5x Halonia tetrastycha, Goepp..... x Sph. divaricata, Goepp. «| |X| X Walchia antecedens, Stur........... *s Sph. Falkenhaini, Stur. .......... x| Pinites antecedens, Stur. .......... x Sph. striatula, Str ......cccccssee x Rhabdocarpus concheformis, Sph. Ettingshauseni, Stur. ..... rs Goepps ey sec anaence te, 25 28 Although it has not hitherto been found in Moravia nor in Austrian Silesia, yet Productus giganteus is well known in the.Culm deposits of Rothwaltersdorf in Lower or Prussian Silesia, between which and Zone 2 of the Sudetic Culm there is much in common. The plants which are enumerated above, and which form the special object of Prof. Stur’s memoir, are fully described and most beautifully figured in the numerous plates of this handsome work. G. A. LEpour. CORRESPONDENCE. Sire Nee “WULFENITE” AT “CALDBECK FELL.” Str,—As Wulfenite has hitherto been recorded from only one locality in the British Isles, viz. Lackentyre in Kirkudbrightshire, it may interest some of the readers of the GzoLocicaL Magazine to 566 Correspondence—Mr. R. Mallet. learn that it has lately been found at one of the Caldbeck Fell mines, in Cumberland, associated with Pyromorphite, Anglesite, and various other ores of Lead. As Molybdenite is rather common in some of the adjoining mines, the occurrence of Melybdate of Lead might, perhaps, have been expected, as a result of the decomposition of Molybdenite and Galena. Another mineral new to the British list has just been detected in the Hematite mines of the Cleator district. This is Hausmannite, which occurs, well crystallized, in small pockets and veins associated with Pyrolusite, mostly between the hematite and the limestone in which it is found. - Further notices of these minerals will appear in the Memoirs of the Geological Survey. J. G. GoopcxuiLp. PENRITH, 9¢h October, 1875. PRISMATIC STRUCTURE OF BASALT. Sir, —Assuming the description of the three basaltic prisms in the collection of the Geological Society as given by Mr. Scrope to be exact (see Gront Mac. 1875, Decade II. Vol. II. p. 412), the facts do not in any way conflict with the explanation that I have given of the mode of production of the lenticular cross-joints in basaltic prisms. The prisms referred to must have come from that part of the original mass in which occurred the dividing surface between that part cooled from the top and that cooled from the bottom of the mass, as is proved with respect to one of the prisms by the existence in it of a joint having surfaces concave in both direc- tions, such plane in fact passing horizontally through this articula- tion; other adjacent prisms may have their joints, within certain limits above or below this plane, either convex upwards or down- wards, for the slightest differences in the conductivity or conditions and rates of cooling will suffice either to depress or elevate, by a greater or less distance, the plane already spoken of. It is also not difficult to see that several alternations in the directions of the con- cave or convex surfaces may occur in the neighbourhood of the meeting plane of cooling in opposite directions, where, as in the case of other divergent or opposite heat waves, more or less confusion in normal structure must occur. 18th October, 1875. Rost. Mauer. THE INVERTED STRATA OF THE MENDIPS. Sir,—Referring to Mr. A. M‘Murtrie’s interesting paper “upon certain isolated areas of Mountain Limestone at Luckington and Vobster’’ (read in Section C. of the late Meeting of the British Association at Bristol), wherein he showed these isolated patches to have been passed beneath and found separated from any underlying portion of the same limestone, it occurred to me at the time that the structural peculiarities of certain places I had examined would tend to explain those described in the paper, the whole of which I had not the good fortune to hear read, and therefore refrained from offering the following remarks in the Section. Correspondence—Strata of Mendip Mills. 567 It appeared that along the Luckington and Vobster side of the Mendip Hills, the abnormal inverted or apparently discordant junc- tion of the disturbed Coal-measures at their foot, with the limestones of the range, is traceable for about five miles, two of the three out- lying, and, as I could gather, inverted patches of limestone being situated at distances from the junction of somewhat more than a mile and a little less than three-quarters of a mile respectively. The hypothesis that these outliers were portions of underlying lime- stones brought to the surface by faulting, having been set aside by the fact of the outliers’ non-continuance in depth, the author favoured the idea of inversion instead. That such an amount of mversion as Mr. M‘Murtrie suggested is by no means an impossibility I can well conceive, having seen, in the case of a narrow and much compressed anticlinal ridge, on the confines of Afghanistan, a strong band of hard limestone with a great thickness of overlying sandstones and clays, so completely in- verted that this limestone band could be traced curving upwards and outwards from its place on the flank of the anticlinal, until found to rest for nearly half a mile with completely inverted horizontality upon the likewise inverted sandstones and clays, the whole of the rocks being well exposed, and the inverted limestone capping spurs from the anticlinal range, thus :— ee A. Limestones. B. Sandstones and Clays. ¢. d. Inversions of varying width up to above + mile or nearer half a mile English. In the country where this occurs nearly all the boundaries of numerous parallel anticlinal ridges are lines of abnormal vertical or inverted junction of the two groups represented above, these ridges having lengths sometimes exceeding fifty miles, and the only places where the rocks are found in their, so to speak, natural or normal order being where the beds fold over the terminations of the anti- clinal axes. Such lines of abnormal junction or inversion are also known to exist for greatly longer continuous distances on the flanks of the Himalayas and the Alps. But admitting inversion in the case of the Luckington and Vobster 1 See paper on the Alps and Himalayas, by H. B. Medlicott, Hsq., Quart. Journ. Geol. Soc. 1868, vol. xxiv. p. 34, and a paper On Some Points in the Stratigraphical Structure of the Panjab, op. cit. 1874, vol. xxx. p. 61. 568 Correspondence—Mr. G'. H. Kinahan. outliers, the steps by which the isolation and removal of these patches to a distance was accomplished remain to be traced; and here, perhaps, without undue exercise of imagination where evidence is wanting, it may be suggested that after inversion the adjacent face of the Mendips might have assumed the form of a high escarpment made up of the softer Coal-measures capped by the overthrown limestones, when land slippage, during the wasting backwards of the escarpment, might have taken place, allowing large masses of the harder rocks above to subside; or a succession of landslips might each be accompanied by an outward as well as a downward movement. In support of this suggestion, ] may mention an escarpment some 1500 to 2000 feet in height, with which I am acquainted, composed of various soft and more consistent beds. below, capped by unusually hard and massive ones above. Along this scarp land-slippage has taken place to such a degree that great detached masses of the upper sections have settled down on the sloping outcrop of the softer beds, until they have, in several instances, arrived by combined processes of slipping and weathering back at distances from their main outcrop quite comparable with those of the outliers in question from the suggested escarpment of inverted beds. Some of these detached masses exceed the dimensions of the Upper Vobster outlier ; and, so far as can be judged without having seen the locality, there appears to be no insuperable difficulty in accounting for the position of these outliers in this. way. It should be noticed in connexion with the subject of such great inversions, that disruption or faulting may have accompanied the distortion of the anticlinal arches, permitting the inverted strata to fall away, or else the whole set of beds, including both the limestones and those above them, must be supposed to have turned back upon themselves again, as shown in the figure at E. No instance, upon a large scale, in which this is proved to have occurred, has fallen within my experience, though some sections have suggested it, and in the absence of such recurvature, displacement amounting to faulting may, after all, have been a necessity in some part of the process. by which these features were produced. a a B On tHe Nomenciature or Rocks. Please correct the following in the Gronogicat Magazine for September :-— Page 426, line 22, in two places, trachylyte for trachalite. G. H. Kinawan. BOULDER-CLAY IN IRELAND. Sir,—I can assure Mr. Birds that it is perfectly incorrect to suppose that an Upper Boulder-clay in Ireland resting on “ middle sands and gravels” has been proved in any place. Normal Boulder-clay has been found in many places resting on sands and gravels, but the latter cases are of an age prior to the accumulation of the Glacial Drift Correspondence—Mr. Collins, Mr. D. Mackintosh. 569 of that country. Some of these old sands and gravels have been made to do duty for the “ middle sands and gravels,” while in other places the so-called “‘ Upper Boulder-clay ” is a glacialoid drift, a meteoric drift, or an aqueous drift, in which a few blocks or frag- ments of stone can be found, still retaining some ice-scratches. . Wexrorp, October 5, 1875. G. Henry Krnanan. FORMATION OF A MINERALOGICAL SOCIETY. Str, —An effort is being made for the establishment of a Mineralo- gical Society of Great Britain and Ireland. Will you permit me to call the attention of your readers to this fact, and to say that I shall be happy to give information on the subject to any persons who may desire to become members, The objects of the Society are— To simplify Mineralogical Nomenclature. To determine and define doubtful mineral species. To study the Paragenesis of minerals. To record instances and modes of pseudomorphism with their accompanying phenomena. To measure, determine, and illustrate forms of crystallization, especially the irregularities and peculiarities of particular planes, or of crystals from particular localities. To discuss systems.of classifieation, and to establish a natural system. To collect, record, and digest facts and statistics relating te economic mineralogy. To promote the exchange of specimens; and, generally, To advance the Science of mineralogy. The rules and regulations to be ultimately adopted will be decided upon by the votes of probably the first 100 members. 57, Lemon Srreet, Truro, J. H. Cottins, September 17th, 1875. ORIGIN OF ESCARPMENTS AND CWMS. S1r,—Several years ago you kindly published a number of articles by me on Denudation, and likewise the answers they elicited from several well-known geologists. 'The substance of these articles was afterwards incorporated with my work entitled ‘« Scenery of England and Wales, its Character and Origin,’ in which, among other sub- jects, I entered into a detailed consideration of the origin of escarp- ments and cwms, especially the very typical cwms of North Wales. Since then Mr. Kinahan has written a work on the Surface-geology of Ireland, which to a great extent is a repetition in different words of the kind of arguments I adopted in reference to England and Wales ; and Mr. Goodchild in several recent articles in the Gron. Mae. has (evidently without being aware of what I had written) not only used many of my arguments against Subaérialism in substance, but, in several cases, coincidentally expressed them in nearly the same words. This will be seen from a comparison of some portions of Mr. Goodchild’s articles with the following quotations from my work on Hngland and Wales :—‘“ Carrying away the blocks and fragments, the removal of which must, in a general way, have kept pace with the recession of the cliffs..... the power of a moving crust of land-ice several thousand feet thick to excavate cwm-shaped 570 Correspondence—Miss M. B. Alder. hollows..... could only have done so on meeting with an obstruc- tion such as a steep slope which would deflect the current of ice, and make it acquire a gyratory motion which would enable it to scoop out semicircularly backwards, and possibly at the same time downwards..... To be a cwm a hollow must be approximately curvilinear. Rain is doing all it ean to destroy this curvilinearity. Rain-streamlets in cwms are gullying their brims and channelling their sides. A continuation of the process would render a cwm a mere confluence of ravines. The chipping action of frost, aided by rain, is tending to reduce the steepness of the encircling cliffs by bevelling off their upper parts, and hiding their bases under screes. Rain in a state of dispersion is possessed of so little power that it cannot keep up a uniform abrasion of the sides of cwms so as to preserve their curvilinearity..... If a single stream cannot produce a cwm, several streams cannot combme so as to give rise to a cwm. . Springs would be incapable of undermining laterally so as to lear a hollow at all approaching to the breadth of an average Cwm, while a spring undermining backwards would leave a ravine, not a cwm..... Springs and streams are the effects instead of the cause of cwms..... What is the stream now doing in the upper part of its course, for instance under Glaslyn [Snowdon]? Merely rutting a continuous face of rock.” The above are only a few quotations selected from many passages to the same effect. I have likewise, in articles in the Guot. Mae., etc., frequently referred to the evidences furnished by glaciated rock-surfaces in peculiar positions, and by the undisturbed curvilinearity of eskers, of the very small influence exerted by rain and freshwater streams since the Glacial period. While, however, agreeing with much that Mr. Goodchild has written, I cannot help differing from him on many points—such, for instance, -as the forms he assigns to the traces of sea-action; but I fear I have already trespassed too much on your increasingly valuable space. D. Macxintosa. “ BOTTLEITE.” } Sir,—It gives me great pleasure to find that Mr. G. H. Kinahan admits that the curious black mineral ealled ‘“ Bottleite,” attached to the base of some layers of granite, ‘‘seems due to crystalline struc- ture, the substance being deposited from solution.” (See his letter Grou. Maca. for September last, p. 426.) As I have long held that Flint is stalactitic, so I feel certain is Bottleite, a siliceous “ stalactite” which has dripped, so to speak, out of the granite. Whatever Bottleite and Flint are, Obsidian and Isopyre must be classed with them.? More information is anxiously looked for by Yours, ete. M. B. Auprr. Fern Bank, Hotywoop, Co. Down. Sept. 22nd, 1875. 1 Mr. Allport, F.G.S., remarks: ‘‘ ‘ bottleite’ and ‘trachalite’ are synonymous, ‘ bottleite’ beimg the local name for a vitrioid rock pronounced to be ‘trachalite.’ ’’?— Epir. Guou. Mac. 2 We venture to suggest that Miss Alder has opened a wide field of inquiry for Mr. Collins’s proposed New Mineralogical Society. (See ante p. 669.)—Kprr. Grou. Mae. Obituary—Mr. F. E. Edwards. 571 iS ser AL Ee nya FREDERICK ERASMUS EDWARDS, F.G.S., BORN OCTOBER 1, 1799, DIED ocTOBER 15, 1875. Some five-and-thirty years ago, a little society was founded by a few London geologists, namely, Dr. J. 8. Bowerbank, F.R.S., F.L.S., F.G.8S., Searles V. Wood, F.G.S., John Morris, F.G.S., Alfred White, F.L.S.,. Nathaniel T. Wetherell, F.G.S., James de Carle Sowerby, F.L.S., F.Z.S., and Frederick E. Edwards, F.G.S., for the purpose of illustrating the Hocrnz Mo.zusca, and entitled “The Lonpon Cray Cuvs.” Who would have supposed that this society, so small and unpre- tentious in its outset, should have given birth to one of the most useful and valued scientific societies in London? the Pataonro- GRAPHICAL SocreTy, which has now existed for twenty-nine years, and numbers more than 350 members! A society which has pro- duced 28 huge annual quarto volumes, containing 7840 pages of letterpress, and illustrated by 21,778 figures of 4273 species: not confined, like the original enterprise, to the illustration of the London Clay Mollusca, but aiming eventually to accomplish the task of illustrating all the fossil remains found in the British rocks ! . Of the seven geologists who founded the old “ London Clay Club,” five still survive, namely : Dr. J. S. Bowerbank, F.R.S., F.L.S., F.G.8., Pres. Pal. Soc.; Searles V. Wood, F.G.S., Treas. Pal. Soc.; Prof. Morris, F.G.S. ; Alfred White, F.L.S. ; Nathaniel T. Wetherell, F.G.S. James de Carle Sowerby died in 1871,' and we have now the sad task to record the loss of another of these early workers in paleon- tology, that of FrepERick EH. Epwarps, the historian of the Hocene Tertiary Mollusca. . Brought up to the profession of the law, and filling the responsible post for more than forty years of chief clerk to Masters Wingfield and Blunt, and to Vice-Chancellors Kindersley and Malins, he de- voted his entire leisure time to the collection and study of the Mol- lusca of the Hocene Tertiaries of England. 1. His earliest contribution appeared in the “London Geological Magazine,” for September, 1846, edited by H. Charlesworth, F.G.S., “On the Hocene Telling,” and at a later date, at intervals, in the monographs of the PaALmoNnTOLOGICAL SocrETy appeared : 2. In 1848, “‘ The Eocene Mollusca,” Part I. CepHatopopa (with nine plates). 3. In 1854, 3 3 Bi Part II. Putmonara (with six plates). 4. In 1854, 5 - o Part III. No. 1, ProsoprancHiATa (with eight plates). 5. In 1855, 5 aH 50) Part III. No. 2, ProsoprancuraTa continued (with four plates). 6. In 1858, Aaa oF - Part III. No. 3, ProsoprancHiaTa continued (with six plates). 1 See Obituary Notice of Mr. Sowerby, Grou. Mac. 1871, Vol. VIII. p. 478. oe Miscellaneous. 7. ‘Notice of the Fossil Remains of a New Freshwater Mollusc from the Lower London Tertiaries,” in the “‘ Geologist,” 1860, vol. i. p. 208, pl. v. 8. “ Descriptions of Some New Kocene Species of Cyprea and Marginella,’ in the Grou. Maa. 1865, Vol. II. p. 536, Pl. XIV. It is an unfeigned source of regret to all workers in Hocene geology that after this date, owing to his failing health, Mr. Edwards ceased to publish the results of his long and careful examination of his great collection, the formation of which occupied the greater part of his lifetime. . His friend Searles V. Wood, ¥.G.S. (Treasurer of the Paleeonto- graphical Society), well known for his valuable monographs on the Mollusca of the Crag, took up the ‘‘Hocene Bivalves” in 1859, in 1862, and again in 1870, publishing three parts, illustrated by 25 plates; but much yet remains to be done in order to complete the entire series. Fortunately for science, Mr. Frederick Edwards’s magnificent col- lection, contained in five large cabinets, has been acquired by the Trustees of the British Museum, and now forms a part of the National Collection ; as also does a part of the fine series of Hocene Mollusca obtained by N. T. Wetherell, Esq., F.G.S., from the neigh- bourhood of Highgate. In future, students of Eocene Fossil shells may avail themselves of the advantages which these valuable collections afford them for purposes of scientific work. Though often harassed by family cares and anxieties, and op- pressed with the responsibilities of his official work as a solicitor, daily occupied in hearing and adjudicating upon difficult cases in Chancery, in private life Mr. Edwards was nevertheless greatly beloved by those who knew him intimately, and, when his health permitted, he delighted to gather his geological brethren around his table, and revive in his later years those pleasant social and quasi- scientific reunions which formed the bond of cohesion among the members of the old “‘ London Clay Club.” J. M. anp H. W. NEES Cia ASN @ Wis. Oou1tic Bracuioropa.—Mr. J. F. Walker, M.A., F.G.S., exhibited at the last meeting of the Yorkshire Naturalists’ Club, the following species of Brachiopoda which occur on the Continent, but are scarcely known as British species, viz. Terebratula bisuffarcinata, Schlot., and Rhyn. Thurmanni, Voltz., from the Lower Calcareous Grit of Filey, Yorkshire Coast; Waldheimia umbonella, Lamarck, from the Kelloway Rock of Scarborough; Terebratula Eudesii, Oppel, and Terebratula ventricosa, Yieten, from the Inferior Oolite of Cheltenham; and Terebratula Ferryi, Des., from the Inferior Oolite of Dorsetshire. Inpran Gerotogicat Survsey.—We regret to learn that Dr. Wm. Waagen, of the Geological Survey of India, has been obliged by ill health to resign the appointment of Paleontologist, his promotion to which we lately noticed. THE GEOLOGICAL MAGAZINE. NEW “SERIES.” DECADE ils “VOL Ir No. XII.—DECEMBER, 1875. (@ err Gen Ade eASEe hv @ ae Ss —————_—_——_ J.—Tue Cause oF THE GLACIAL PERIOD, WITH REFERENCE TO THE BritisH Isuss.! By Cuaruxrs Ricketts, M.D., F.G.S. ie is a fact universally accepted that, within a period comparatively recent, extensive districts in North America and in Hurope, now fruitful and luxuriant, were covered with a thick mantle of snow and ice; and their valleys were filled with glaciers, which extended into the sea, and, breaking off at their extremities, floated away as icebergs. The causes which produced a temperature of such severity, as the evidences upon which this opinion has been founded indicate, have excited much speculation. The theory which of late has found most advocates is that proposed by Mr. Croll:—That the winters during this, the Glacial Period, happened in aphelion, when, as a result of a greatly increased eccentricity of its orbit and the precession of the Equinoxes, the Harth was eight and a half millions of miles further distant from the. Sun during winter than it is at present; that therefore the winters would have been longer and the cold more intense; that the North Polar regions were entirely covered with a thick capping of ice, so great that the accumulation caused a displacement of the Harth’s centre of gravity; and to this cause he attributes the submergence of the land which is constantly found where evidences of glaciation have been observed. He also justly concludes that the so invariable occurrence of submergence along with glaciation points to some physical connexion between the two. But the submergence of Greenland, beneath its present rapid accu- mulation of snow, cannot be referred to such a cause as a change in the Harth’s centre of gravity, for at the same time and in about the same latitudes—in Norway and Spitzbergen—the land is rapidly rising. It seems not improbable that the recent recession of the glaciers in Norway may account for the rise of land there, in con- sequence of the removal of pressure, and, to a similar cause, its occurrence, subsequent to the Glacial Period, may be attributed. Ihave elsewhere (Grou. Mac. Vol. IX. page 119) attributed this subsidence during the Glacial Period to the effects of the pressure which this increased mass of snow would have in forcing downwards the crust of the earth into its fluid substratum ; basing my opinion, — upon the constant occurrence during all geological time of evidences 1 Read before the British Association (Section C.) at Bristol, August, 1875. DECADE II.—VOL. I1.—NO XII. 37 574 Dr. Ricketts—On the Cause of the Glacial Period. of subsidence and accumulation co-existing in the different forma- tions,—on the existence of bays and of deltas at the mouths of all great rivers, being the submerged and filled-up continuation of their valleys; in the latter the result of artesian borings has proved the occurrence at various depths of evidences of what have been succes- sive land surfaces,—on the depression which took place during the Glacial Period, and the partial re-emergence of the land when it was relieved of its weight of ice and snow,—and on the subsidence recently occurring in Greenland simultaneously with a rapid increase of accumulation of snow. The occurrence of subsidence of land being due to the pressure of accumulations, though it has been advocated by Sir John Herschel, by Prof. Hall of New York, and by Dr. Dawson of Montreal, appears in a singular manner to have escaped the consideration of geologists ; though by this circumstance only can a satisfactory explanation be given of many geological phenomena. Nevertheless, the fact of their simultaneous occurrence is constantly recognized." The relative positions under which the two Poles are placed are so different, that great care must be taken in arguing from the state of one-to that of the other. It must not be inferred that because it may be possible that the land, situated at the South Pole and sur- rounded by water, is covered with an ‘“‘ice-cap,” that therefore the ocean, situated at the North Pole and surrounded by land, would be covered in the same way. It appears to be more than doubtful whether, with the existence of an Arctic Ocean having communica- tions open with the Atlantic and Pacific, an “ ice-cap” comparable with that covering the land about the Antarctic Pole could by any possibility exist; for before a resting place could be found sufficient to bear such an accumulation of snow, as has been supposed to have at one time existed, the whole sea must have been frozen even to its lowest depths; and that could not take place whilst salt water continues to get denser as it becomes colder, and there is also a free communication between the Polar Sea and the Atlantic. Nor could there have been, during the Glacial Period, any great thickness of snow on the land surrounding the Arctic Sea; for per- 1 Tn the President’s Address to the Geologists’ Association, Nov. 7th, 1873, Mr. H. Woodward, F.R.S., has objected to the theory of subsidence being the result of accumulation, on the grounds that if in the Bay of Bengal (where, by the artesian borings made in the Delta of the Ganges, the land has been proved to have sunk to the depth of 481 feet and upwards) the sediment deposited has power by gravitation to thus depress the ocean-bed, much more ought the solid mass of the Himalayan range, with its innumerable and lofty peaks, to sink into the yielding crust beneath (Grou. Mac. 1873). But the areas out of which the Himalayas have been sculptured have, from the commencement of their present denudation, been sustained above the sea-level, and the weight to be supported has diminished, as particle after particle has been removed, the peaks and valleys registering a portion, but by no means the greater amount, of the denudation the mass has undergone ; so that the Himalayas, im consequence of the great amount of denudation to which they have been subjected, will not press with so great a weight upon the fluid substratum. But if the sediment brought down by the Ganges and Brahmapootra has caused, by its weight that subsidence which has taken place in the Bay of Bengal, it necessarily follows that the area, forming and supporting these mountains, must rise in accordance with “the amount of material removed. Dr. Ricketts—On the Cause of the Glacial Period. 575 petual snow existed as far south as the latitude of New York, and the greater part of Hurope was covered with it; the wind passing over a land surface of such extent and having a glacial temperature, would have had almost the whole of its water condensed out of it long before reaching the Arctic Circle. “The wet would be squeezed out by the cold, as water is wrung from a sponge.” ? Even when the winds have to pass over land, the mean temperature of which is considerably above the freezing-point, the air parts with so much of its moisture that at no time, since the Mammoth and woolly- haired Rhinoceros roamed over the plains of Siberia, has there been in Northern Asia so great an accumulation of snow as to form glaciers ; otherwise the remains of these animals, found in the banks of the Lena, would have been swept by them into the Arctic Sea ; yet during all that time the soil, in which they have been imbedded, has continued so persistently frozen that their remains have been preserved with the soft parts undecomposed. It does not at all follow that, with diminution of temperature in the Arctic regions, there should also have been at the same time reduction of the winter temperature of the British Isles. The present temperate and equable climate of Britain is dependent on the warmth of the waters which, derived partly from those of the Gulf Stream and at a lower temperature from those of the Temperate Zone, are carried as a set or current towards the Polar regions ; and, being many degrees higher than would otherwise be the mean annual temperature of the British seas, modify also the temperature of the air passing over them. Dr. Carpenter has, as I believe, demonstrated that what I will call the North Polar Current (termed in Johnston’s Physical Atlas, “ North-Hast Branch of the Gulf Stream”) is dependent on the effects which diminution of temperature in the Polar regions has in causing the displacement by sinking of the ‘surface water of the Arctic Sea, the density of which has been increased by the tempera- ture being diminished, and the necessary influx of lighter water, that is, the comparatively warm water derived from the Gulf Stream and the Temperate Zone, to replace the colder which has subsided. The North Polar Current thus produced, and consisting of water very much warmer than the surface temperature of the North Atlantic would be, if this current did not exist, supplies heat and moisture to the atmospheric currents passing over it; so that partly on this account, and partly from the inability of heat to radiate so readily from the surface of the land in consequence of the frequent cloudiness of the sky, the winter temperature of Britain is con- siderably milder than it would be under different conditions ; whilst in summer it is often modified by the difficulty with which the sun’s rays can penetrate when, from the same cause, there is an excess of cloud or vapour in the atmosphere. If the peninsula of Florida did not exist, the winter temperature of Britain would be still milder, as, in consequence of it; the Gulf Stream has to traverse a distance of several hundred miles more than would be the case otherwise. 1 J. Campbell, F.G.S. “ Frost and Fire.” 5/6 =Dr. Ricketts—On the Cause of the Glacial Period. Changes of climate are now taking place for which I can imagine no adequate cause, excepting the reckless destruction of the great American forests. The temperature of Iceland and of Greenland is much more rigorous than when they were first discovered ;' whilst, upon the other hand, the glaciers of Norway are receding, and the Christmas of tradition visits us at very distant intervals. Even temporary changes as indicated in North America appear to influence our winters; thus of late years the most severe winters there, such as those of 1872-73 and 1873-74, were with us re- markable for their mildness. The opposite conditions have also been noticed ; such as occurred during the Russian War in 1854-55, when the frost on the Hastern shores of the Atlantic was intense, whilst the winter was mild in Northern America. It has been stated . that ‘‘it is a saying amongst the Danes that there is mild weather in Iceland when it is cold in Europe, and vice versd.”’* Previous to the Glacial Period there existed a very different contour of the North American continent from the present. The Gulf of Mexico extended over what is now the valley of the Mississippi, even to St. Louis, upwards of 600 miles north of New Orleans; the peninsula of Florida was submerged ; and along the east coast a very considerable belt of land, extending to the Alleghany Mountains, was sunk below the level of a sea whose waters were of a tropical temperature, Such a variation in the coast-line must have had a great effect upon the climate. With a Gulf of Mexico extending 9° farther north than it does at present, the air, heated and charged with moisture derived from its tropical waters, would have been directed up. the valley of the Ohio by the western flanks of the Appalachian chain, and have modified the climate even of extreme northern districts. Florida presenting no obstruction, the Gulf Stream must have been impelled many degrees further northwards by the wis a tergo—the N.H. and 8.EH. trade-winds—carrying a larger quantity of Equatorial water than it now conveys, namely, that which is deflected round the western extremity of Cuba and what escapes over the Bahama banks and channels. ‘Therefore the amount of heat derived from the tropics which was conveyed to high northern latitudes must have been immensely increased. I am not aware whether it is possible to co-ordinate those beds abound- ing in plant-remains, which have been discovered in Greenland, in Iceland, and in Spitzbergen, with those indicating these changes in the coast-line of America; but such alterations must have induced a condition of temperature at all events nearly approaching, if not similar to, that which these plant-remains indicate. As the present state of the winter temperature of Britain depends on the volume and warmth of the North Polar Current, the waters of which are, to a considerable extent, derived from those of the Gulf Stream, it follows that any serious diversion of this stream would affect our climate in an opposite direction. There are two areas in the isthmus which separates the Atlantic 1 A Visit to Iceland. By Madame Ida Pfeiffer. Page 64. ; 2 Iceland: its Scenes and Sagas. By S. Baring-Gould. Page xxx. Dr. Ricketts—On the Cause of the Glacial Period. 577 from the Pacific where a comparatively slight depression would cause the two oceans to mingle. The Panama Railway cuts through a ridge which is 299 feet above the sea-level; and, near Lake Nicar- agua, the lowest pass is 133} feet above the sea,? whilst the isthmus nowhere attains the height of 1000 feet.* Should depression take place so as to submerge these areas, there would be no impediment to the Atlantic Equatorial waters passing into the Pacific Ocean, for the mean height of the former is somewhat greater than that of the latter—that is, it is somewhat banked up by the action of the trade-winds. In considering the West Indian Islands as the remains of a sub- merged part of the continent of South and Central America, Mrs. Somerville has given the true explanation of the formation of the Gulf of Mexico; but the depression by which they have been formed has extended to a greater depth than the present. In Jamaica the Tertiary strata are more than 5000 feet thick,* and Santiago in San Domingo, situated 2000 feet above the sea, rests on Tertiary strata.5 The whole valley of the Mississippi to beyond its junction with the Ohio once formed a portion of the Gulf of Mexico, the land having sunk considerably below its present level. Former depression has also taken place along the western coast. Professor Newberry observed a sea-beach, containing shells similar to those now existing in the ocean below, at 80 or 90 feet above high- water mark, and also ata still greater elevation ;* and the Gulf of California is but a submerged extension of the valley of the Colorado River. It is not probable that subsidence could have occurred to so great an extent on both its sides without the same process also affecting the isthmus. The present fauna on the different sides of the isthmus affords in- dications of a former intercommunication of the two oceans; by the identity of species in some instances, by the similarity in others. Mr. Philip P. Carpenter (British Association Report, 1856) regards 35 species of shells as identical in the two oceans; 34 species are so nearly allied that they may prove to be identical; and 41 species really separated but by very slight differences only. Professor Wyville Thomson, in “ Depths of the Sea,” arranges side by side 18 Hchino- derms from each sea, “which resemble one another so closely in habit and appearance as to be at first sight hardly distinguishable.” There have been few, if any, investigations made for the purpose of determining the question, but these evidences are almost conclu- sive that submergence of the isthmus has taken place so as to permit 1 Admiralty Chart. 2 The Naturalist in Nicaragua. By Thos. Belt, F.G.S. Page 35. 3 Tertiary Beds in St. Domingo. By T. 8S. Heneken Quart. Journ. Geol. Soc., vol. vi. p. 44. ie 4 Notice of the Geology of Jamaica. By P. M. Duncan, M.B., Sec. G. S., and G. P. Wall, F.G.S. Quart. Journ. Geol. Soc., vol. xxi. pp. 5 and 6. 5 On Tertiary Beds in San Domingo. From Notes by T. 8S. Heneken, Quart. Journ. Geol. Soc., vol. vi. page 39. ® Colorado Exploring Expedition.—Geology. By Dr. J. 8. Newberry. Page 12. 578 Dr. Ricketts—On the Cause of the Glacial Period. the waters of the two oceans to mingle. If it has occurred to any considerable extent, it must necessarily have progressed in an increas- ing ratio, unless there were any counteracting forces brought into action ; for the causes which induced it would still have been in operation; sediments brought down by the Amazon and Orinoco would still have been carried into the Caribbean Sea, and in much greater quantities, for the Equatorial Current, meeting with no obstruc- tion at the isthmus, would have been propelled. with greater celerity by the trade-winds; whilst such portions of the sediments from the Mississippi, as are now carried towards Florida, would have been de- posited in the Gulf, and, if the winter climate in the north increased in severity, the amount of these deposits would be augmented, as the frost would disintegrate the rocks more rapidly, and in a greatly increased ratio, if the land was covered with glaciers. If the temperature of our island can be influenced in any appre- ciable degree by changes of temperature affecting the Arctic Ocean, the winter temperature would be lowered to an immensely greater. extent should any considerable volume of Equatorial water be diverted across the supposed submerged isthmus, for the hottest of the water would pass into the Pacific Ocean; whilst according to the size and depth of this diverted current, the Gulf Stream in the Atlantic would become less and less, in consequence of the diversion of that force by which it was impelled forward. With an indentation of Central America similar to the present, ‘there could, under no circumstances, have been the same amount of warmth conveyed to such high southern latitudes by the Brazilian Current as now passes to the north by the Gulf Stream, for, not only the whole of the northern division of the Equatorial Current must have been propelled into the Caribbean Sea, but a considerable amount of the southern division also, from which, on account of the obstruction caused by the south-east trade-winds, there would be no method ef escape southwards, and therefore it must have been borne towards the north, as it is now by the Gulf Stream. But should there have been depression of the isthmus, not only would © there have been, as we have seen, reduction of temperature in the North Atlantic, but in the South Atlantic also; for if it were not for the obstruction caused by the isthmus, the power and extent of the Brazilian Current would be much decreased, in consequence of the greater portion, and that the hottest, of the southern division of the Equatorial Current continuing onwards past Cape St. Roque, so much of it not being deflected along the east coast of South America as there is now. If this submergence of the isthmus has taken place, and it is the necessary result of those changes which were in progress during the Tertiary Period, the extension of the Gulf of Mexico northward would still have continued, as it did then, far into the interior of the continent; but with the deflected Equatorial Current it would no longer be supplied with water of a tropical temperature, but would have had the normal temperature of the latitude, and even this would have been greatly diminished by the glacial coldness of the waters brought down by the Mississippi and the Ohio. Dr. Ricketts—On the Cause of the Glacial Period. 579 With the removal of the Gulf Stream the North Polar Current could have had no higher temperature than that which it derived from the Temperate Zone, thus greatly intensifying the cold, so that the moisture which the atmosphere contained would have been condensed out of it in the form of snow in much lower latitudes than at present, probably forming a great ice-barrier across the northern extremity of the North Atlantic. With such an extensive field of ice between the Atlantic and Arctic Oceans it is improbable that sufficient water could remain in the atmosphere to admit, within the area of the latter, sufficient precipitation to form ice- floes as extensive, or as thick, as occur there now. With the British Isles covered with a great thickness of snow, and with glaciers coming down to the sea, it may be presumed that the southern limits of the ice-drift might have ranged from some- what south of 50° N. to about 60° N. near the longitude of Iceland ; but an extensive frozen area, such as it would have formed, would condense the water contained in the atmosphere, so that, upon the supposition that there exists an open Polar Sea where our Arctic explorers expect to find it, the ice-floe caused by its precipitation could then have hardly extended much farther northward than the latitude of North Cape, the most northern point of Norway, and beyond it there would probably have been an open Polar Ocean. Prof. Geikie and Mr. James Geikie have shown that in Scotland there are evidences which demonstrate the occurrence of a succession of Glacial Periods, having intervening times characterized by a mild and even genial climate. These intercalated temperate periods have been considered to be indirectly due to the precession of the Equinoxes, which during a period of extreme eccentricity would gradually have caused the supposed ice-cap to shift from one pole to the other. The occurrence of a succession of depressions and upheavals of Central America, causing communications and separa- tions of the two oceans, would certainly cause the same phenomena to take place, and might not only account for these interposed Glacial Periods, but also for the occurrence of shells having a boreal character during intervals in the Tertiary Period. It is a circum- stance not unlikely to have happened, but of which we have no absolute proof; nor has any evidence of it been sought for. ‘Tempo- rary upheavals and subsequent depression have been not unfrequent both during the deposit of Paleeozoic as well as more recent forma- tions. Mr. P. P. Carpenter has suggested that the intercommunication between the two oceans may have been correlative with the glacial conditions in Huropean seas; whilst others, and none more clearly than Messrs. Croll and Geikie, have demonstrated how immensely the temperature of the North Atlantic would be diminished by the removal of the Gulf Stream, causing “Scotland to experience a climate as severe as that of Labrador, while the greater part of Norway would be uninhabitable.” ? It has now, I think, been proved that, with the present contour of the 1 Mr. James Geikie, ‘‘ Great Ice Age.” 580 Capt. F. W. Hutton—A Glacial Epoch in 8S. Hemisphere ? shores of the North Atlantic, the occurrence of extreme cold, dependent on the winters occurring when the earth is at its greatest distance from the Sun, and during great eccentricity of its orbit, is inadequate to cause glacial conditions in the British Isles and Hastern Europe. The same reasoning which has been used to demonstrate it will also apply to their occurrence as a consequence of a supposed increase of the obliquity of the Ecliptic.! The diversion of the Gulf Stream is upon all hands considered sufficient to produce all those effects which occurred in Britain during the Glacial Period; and there are many evidences which tend to prove that subsidence of the isthmus has taken place, so as to allow of this change in the direction of the Equatorial Current, but, to obtain absolute proof, it is requisite that investigations, with this object in view, be made in Nicaragua and other parts of Central America. Il.—Din tHe Coup or THE GuAcIAL EProcH EXTEND OVER THE _ SouTHERN HEMISPHERE ? By Capt. F. W. Hurron, F.G.S. O many geologists appear to take it for granted that the cold of the Glacial Epoch extended over the whole earth that a few words of caution from the Southern Hemisphere may not perhaps be out of place. The existence in the Pleistocene Period of a Glacial Epoch in Europe and North America having been firmly established, the former greater extension of glaciers in many other parts of the world is considered to be explained by the Glacial Epoch, and at the same time is taken as a proof of the universal extent of the cold, and therefore of its cosmical origin. But we must remember that out of a number of mountain chains which reach above the level of perpetual snow, those only would not show traces of a former greater extension of their glaciers which now happen to stand at a higher elevation than in past ages; and of the chains that do not now attain to the limit of perpetual snow, but had passed that limit at some previous period in their history, would also show traces of former glaciation. So that a former greater extension of glaciers in a district by no means proves a general reduction of temperature; and I need hardly point out that we have but two means of proving a former reduction of temperature at the sea-level, viz. (1) the migration of a fauna towards the Equator, caused by the gradually increasing cold; and (2) the former extension of glaciers into the sea in places where at present they terminate at a certain height above it; and in the latter case the difference of level must be so great that it could not be accounted for by a former greater snow-fall in the district. Now I believe that no good evidence of either one or other of these has been adduced in any country in the Southern Hemisphere, and until this is done 1 Climate of the Glacial Period. By Thomas Belt, F.G.S. Quart. Journ. of Science, 1874, page 461. Variations in the Obliquity of the Kcliptic. By Colonel A. W. Drayson, F.R.A.S. Quart. Journ. of Science, 1875, page 279. Capt. F. W. Hutton—A Glacial Epoch in S. Hemisphere? 581 we must look with suspicion on all cosmical theories which attempt to explain the cold of the Glacial Epoch. Mr. Croll’s theory has found great favour because it was supposed to rest on astronomical evidence, while in reality the astronomical evidence is, if anything, slightly against it; and the theory is founded on speculations in Meteorology, a science not even so well understood as Geology. The theory of the change in the obliquity of the ecliptic, advocated by Lieut.-Colonel Drayson, Mr. Belt, and others, is simply a supposition which is altogether opposed by astro- nomy.! For if the position of the ecliptic has ever changed as much as has been supposed, it is evident that astronomers must be wrong in attributing the present change in the obliquity to the joint attraction of the planets; and in my opinion it is premature to call in cosmical theories, founded on conjecture, to explain the cold of the Glacial Epoch, until we are compelled to do so by the absolute proof of its universality.” : But at present there is no proof of a Glacial Epoch in the Southern Hemisphere, and all the evidence that can be adduced on the subject appears to me to negative such a supposition. ‘There are only three countries where we can expect to obtain proof or disproof of the former existence of a Glacial Epoch in the Southern Hemisphere, viz. South America, New Zealand, Tasmania and Australia; and I have placed the names in the order of their relative import- ance with regard to this question. I will begin with New Zealand, which is the only one of the three on which I can offer any original observations. New Zealand extends over 13 degrees of latitude from 34° 8. to 47° 8. and the difference between the mean annual temperatures of the two extremities is rather more than 10° Fahr. Having resided at Auckland in the north, at Wellington in the centre, and at Dunedin in the south, I can, from my own observations, state that a considerable difference exists in the molluscan faunas of all these three localities. It would, perhaps, be more correct to-say that the northern and southern extremities of New Zealand have each their own fauna (which commingle in Cook Straits), with, however, a pre- ponderance of northern forms. This difference in the faunas is greater than would appear by mere lists, for many species which are abundant in the north are extremely rare in the south, and some species that are abundant in the south are very rare in the north. I do not intend here to go into details on this subject ; I only wish to point out that New Zealand extends over a sufficient number of degrees of latitude, and has a sufficiently different fauna at its 1 The theory referred to by Capt. Hutton is indeed opposed to the views of some astronomers, but not necessarily therefore to Astronomy.—Epit. Grou. Maa. 2 A more serious difficulty for Geologists has arisen than that of explaining the cold of the Glacial epoch; namely, to explain the warm-temperate and even sub- tropical heat of the Earlier Tertiary periods in high northern latitudes. Such changes are not “founded on conjecture.” See Prof. Nordenskidld’s article in the November Number of the Grou. Mac. p. 525. See also Address to the Geologists’ Association, by H. Woodward, F.R.8., Noy. 6th, 1874, Proc. Geol. Assoc. 1875, vol. iv.—Enpit. Gzon. Mae. 582 Capt. F. W. Hutton—A Glacial Epoch in S. Hemisphere ? northern and southern extremities to exhibit migration by change of climate; and of course it is at the centre, or Cook Straits, where we could best trace these migrations. Now it so happens that at Wanganui, in Cook Straits, we have the most extensive Pleistocene shell-bearing bed in New Zealand, and as the fossils are well preserved and easily extracted, it has been pretty thoroughly worked. From this bed 91 species of shells are known, of which 81 are still living in the seas of New Zealand. Of these Murex octogonus, Quoy. Trophon Pavic, Crosse. Fusus Zealandicus, Quoy. Neptunea triton, Lesson. nodosus, Quoy. Cassis pyrum, Lain. Turritella vittata, Hutt. Crypta contorta, Quoy. are not now known to live on the coasts of Otago, although all are, I believe, still found in Cook Straits. On the other hand, Pecten radiatus, Hutt., which at present has only been found living in Foveaux Straits, occurs fossil in the Wanganui Pleistocene bed. There is therefore here no evidence of reduction of temperature in the early part of the Pleistocene period. Below this Pleistocene bed at Wanganui a blue clay is found, from which 98 species of shells have been obtained. Of these, 77 species still inhabit the seas of New Zealand, and consequently I consider this clay to belong to the newer Pliocene Period. Among the recent shells found in it are Murex Zealandicus, Quoy. octogonus, Quoy. Trophon Pavice, Crosse. Fusus pensum, Hutt. caudatus, Quoy. Monilea egena, Gould. Pholadidea tridens, Gray. Zenatia acinaces, Quoy. Venus Zealandicus, Gray. Chione Yatet, Gray. Callista disrupta, Desh. Mysia Zealandica, Gray. Cassis pyrum, Lam. Turritella vittata, Hutt. Crypta costata, Desh. profunda, Hutt. Buceinulus Kirki, Hutt. Zealandicus, Quoy. —— mandarinus, Duclos. dilatatus, Quoy. Euthria littorinoides, Reeve. alba, Hutt. Pholadidea tridens, Gray. Zenatia acinaces, Quoy. Venus Zealandica, Gray. Neptunea triton, Less. nodosus, Quoy. Drillia Nove-Zealandie, Reeve. Buchanant, Hutt. —all of which live north of Cook Straits, but none of them are known from Otago. However, in the same bed Drillia levis, Hutt.,1 and Pecten radiatus, Hutt., also occur, which at present are only known to live in Foveaux Straits. I have also travelled over, and mapped, the whole of the Province of Otago, and have met with no stratified till, nor any marine beds intercalated between glacial or glacier deposits ; although since the Pleistocene Period the land has been undergoing elevation. On the whole, therefore, the evidence is decidedly against the idea that a colder climate formerly obtained in New Zealand. = Callista disrupta, Desh. Dosinia lambata, Gould. Mysia Zealandica, Gray. i A minute shell dredged in Foveaux Straits, which may have been overlooked in the north. ® Dr. Hector, F.R.S., Director of the Geological Survey of New Zealand, was the ye S. Allport—Nomenclature of Rocks. 583 Professor M‘Coy has also come to the conclusion that there was no Glacial Epoch in Victoria. He says: “All our evidence, in fact, goes to show that there was no Glacial Period in Victoria succeeded by a warmer modern one, but that there has been a regular and gradual falling of the temperature to the present day.” ? In his “ Geological Observations on South America,” Mr. Darwin, when mentioning any recent shells found fossil in the Pleistocene beds of Patagonia and Chili, always states that the living forms are found within a few miles of the fossil ones; and never in any in- stance does he mention them as belonging to species now living further to the south. ; I have not seen the late Prof. Agassiz’s account of his visit to Patagonia, further than the short notice published in ‘“‘ Nature,” but I do not think that he procured any evidence of a northerly migra- tion of the fauna in Pleistocene or Pliocene times, followed by a southerly remigration ; nor even of glaciers having formerly entered the sea in more northern latitudes than they do now. However, the evidence, as far as South America is concerned, can be better studied in England than in New Zealand, and the object of this paper is to ‘point out that there is no evidence whatever of a Glacial Epoch having oceurred in New Zealand, although, if it had occurred, there is every reason to expect that it would have left sufficiently clear traces behind it. I will also add that as New Zealand is nearly antipodal to Great Britain, any change of climate in one place, caused by a change in the position of the earth’s axis of rotation, would also necessitate a similar change in the other place. TIJ.—On tHe CrasstFication AND NoMENCLATURE OF ROCKS. By S. Atzrort, F.G.S. N the September Number of the Grou. Maa. pp. 425, 426, there are some remarks by Mr. G. H. Kinahan on the nomenclature of certain igneous rocks, on which I should like to offer a few observa- tions. The rocks referred to belong to the acidic group, and are mentioned under the various names of granite, nevadite, granitic rhyolite, liparite, trachyte, elvanite, siliceous elvanite, felstone, bottleite, trachalite; the two last being synonymous, for it appears that bottleite is the local name for a vitrioid rock pronounced to be trachalite ; but several of the other names are also synonymous or useless, for we are told that nevadite—a proposed new addition to our granitic rocks—is characterized by a more or less crystalline felsitic matrix inclosing crystals of quartz, one or two felspars with mica or amphibole. Now, such a rock may be either a ‘ granitoid first, in 1863, to oppose the notion of a Glacial epoch in New Zealand as quite irrecon- cilable with observed facts; and he showed that the former extension of the glaciers is sufficiently accounted for by the gradual reduction of the surface-area exposed above the perpetual snow-line ; firstly by its erosion into valleys, ridges, and peaks ; and secondly by its gradual subsidence. [See his paper Journ. Roy. Geograph. Soc. 1864, p. 103; and Grou. Maa. 1870, Vol. VII. p. 95.]—Epir. Grou. Mae. 1 Ann. Nat. Hist. 3rd series, xx. p. 194. 584 S. Allport—Nomenclature of Rocks. variety of liparite,’ a ‘granitic rhyolite, an elvanite, or a siliceous elvanite, for the definition given would be quite as applicable to any one as to the others. Nevadite is then said to represent “the passage rock between trachyte and normal granite; similarly, as a siliceous elvanite among the older rocks, is the passage rock between felstone and normal granite.” The author then informs us that he suspects the existence of passage rocks between augite and granite ; and these are subsequently mentioned as ‘“‘maculated basic rocks which seem to graduate into dolerite and augite.” It has, of course, been long known that the extremes of the acidic and basic series overlap, and that some of these intermediate forms exhibit a complete transition from the trachytes to the dolerites; they are, in fact, the trachy-dolerites of Abich, and there are rocks of quite similar com- position belonging to the older geological periods ; but a rock inter- mediate between augite and granite must be something new, and petrologists will, no doubt, be glad to learn something more about it. If to the ten names above mentioned be added andesite, dacite, and domite among the more recent rocks, and felsite, petrosilex, felspar porphyry, quartz porphyry, hornstone porphyry, eurite, pegmatite, granitite, etc., among the older series, the reader will have some faint idea of the amount of confusion introduced into the nomenclature of one group of rocks by the mis-directed ingenuity of those who, like species-makers in other branches of natural. science, are never so well pleased as when inventing new names for mere local varieties. Now it appears to me, that if we wish to introduce something like order and simplicity into our rock-nomenclature, we may as well commence by discarding the old notion of an essential original dif- ference between volcanic rocks of different geological periods; and I imagine there will be found a general disposition among geologists, not only to deprecate the introduction of new names for mere varieties, but also to insist on the necessity of reducing the number of those now in common use. The existence of the two great groups of acidic and basic rocks has long been recognized, not only among the products of recent volcanos, but also in association with strata belonging to the older formations. JI have shown elsewhere, that basic rocks of widely separated geological periods are identical in composition and structure, and every additional investigation clearly indicates that the same generalization may be applied to the members of the acidic group. In the older series, for example, there are the felsites or felstones, and the porphyritic felsites or “ felspar porphyries,” which with the addition of free crystallized quartz, become “quartz porphyries,” ‘elvanites,” etc.; and among the Tertiary or recent rocks there is the strictly corresponding series of trachytes, porphyritic trachytes, quartz trachytes or liparites. The mode of occurrence of all these rocks is precisely the same, and the members of the two groups cannot be distinguished from each other, either by mineralogical composition or structure. It will probably not now be disputed, that there are true granites of all ages, and sooner or later it will be recognized, that the old S. Allport—Nomenclature of Rocks. 585 felstones and porphyries were originally identical with the more recent trachytes ; corresponding varieties occur in both series, and microscopic examination clearly shows that the difference observable in some of the older rocks is the result of chemical or other meta- morphic action to which they have been exposed. There is, however, an occasional difference in texture which should not be overlooked. There can be but little doubt that in the intru- sive sheets of various old rocks we have before us some of the pro- ducts of volcanic action which have been formed far below the surface, or, at any rate, beneath great piles of ejected and loosely- aggregated materials, which have been subsequently removed by denudation. Rocks thus formed under pressure might be expected to differ considerably in structure, if not in composition, from those poured out on the surface; and this is frequently, though by no means invariably, the case: for the central parts of many lava flows are as compact, and exhibit precisely the same texture, as the sheets which have been intruded among the surrounding strata. Generally, however, the upper and lower surfaces of true lava-flows are dis- tinctly vesicular or scoriaceous, a character not exhibited by intru- sive sheets, but one quite as common in Silurian or Carboniferous lavas as in those of recent formation. Intimately connected with this subject is the old distinction be- tween the so-called plutonic and volcanic rocks, a distinction which I have long held to be entirely erroneous in the sense in which it is frequently employed, but which is still maintained by authors of the highest repute, more especially among our German friends. As an example, I may adduce the last edition of Naumann’s “ Lehrbuch der Geognosie” (vol. ii. p. 63), in which it is made the basis of his classification, the plutonic formations being characterized as eruptive rocks not formed by true volcanos. , 3.10 <6. see eee) 455 100:00 Domeyko found the nickel-iron and schreibersite to consist of : Tron = 90°88; Nickel 9-12 100-00 Tron = 65:00; Nickel = 26°30; Phosphorus = 8°70 = 100-00 The density of the iron = 7:51; it does not show Widmannstattian figures when etched, although small plates enclosed in the alloy de- velope a pattern. The numbers yielded by the analysis of the phos- phide correspond with the formula Fe, Ni, P. Meunier adopted a novel means for analysing the nickel-iron: he reduced it to fine particles with a hard file, and fused them with caustic potash in a silver crucible; in this way the sulphur and phosphorus of the troilite and schreibersite are rendered soluble and removed with water. To ensure a perfectly pure condition of the metal it is treated with fuming nitric acid, and is then dried and heated cautiously in a current of air ; when the requisite temperature is reached the particles change colour, those acquiring a blue tint are kamacite, Fe,, Ni, and those a yellow are tiinite, Fe, Ni. In the case of the Deesa iron nearly all the particles turned blue, a yellow grain being observed here and there. Meunier finds the composition of the nickel-iron, iron sulphide and schreibersite to be : JE, Uno == Oilahs IMiekel = 7-8 = SENG, IL. Iron and Nickel = 58; Sulphur (calculated) = 49 = 100. III. Iron = 60-00; Nickel = 26- 75; Phosphorus = 10:29 = 97:04. Vl || Wiss. Wien, 1870, |xi. 26. La Nature, 1878, i. 405.—W. von Haidinger. Sitzdber. Ak. Wiss. Wien, 1870, lxi. 29.—See also G. ‘A. Daubrée. Compt. rend., 1868, lxyi. 671. Dr. Walter Flight—History of Meteorites. 593 I. agrees with Domeyko’s analysis as regards the iron; II., a very imperfect analysis, accords rather with the formula of pyrrhotite _ than troilite; and III. differs considerably from the numbers corre- sponding with the accepted formula of schreibersite. The composition of the portions separated with acid is: SiO, Al,03; Fe,03 FeOQ MgO CaO NaO A. Soluble ... 44:13 trace — 18°52 42°35 — _ trace = 10000 B. Insoluble ... 49:98 546 098 16°79 28°31 3:48 trace = 100-00 In the soluble part the oxygen ratios are approximately those of olivine, in the insoluble part those of pyroxene. While the pre- sence of olivine could not be detected in the mass by any crystalline features, in the insoluble part three minerals were recognised. The most apparent has a blackish-brown colour, lamellated structure and a specific gravity = 3°35. The composition was found to be: Siliciciacidiacsslece. ae .ei ee ROL On ANINI®, ssa cog bag coo ES tron protoxide ... ... ... 24°54 METS, Tacg ocd! ccd Soc LGOH INTE, Goo 8g) cod shoe cos | | BAC 103-24 The second is white and granular, and possesses the following constitution : Silicic acid | free venice) EAC WANES G00 G00 con con. ELS JUTE) gag) cca Sco ade cap) MY 101-50 and closely accords in composition with one of the three (III.) varieties of enstatite met with in the Busti meteorite (see page 411). A third mimeral, to which Meunier has given the name of victorite, resembles hypersthene, occurs in colourless and transparent erystals in a geode of 5 mm. diameter ; they form six-sided prisms terminated with four-sided pyramids. Through some fragments very small opaque black grains are disseminated, with here and there the cavi- ties and rounded enclosures first observed by Sorby. The prisms are grouped in a remarkable way. This mineral, which is present in so small a quantity that none of it could be sacrificed for analysis, has been declared by Des Cloiseaux from the following measure- ments to be enstatite : g'm = 134° 3’ to 134° 20’. gihl = 90° 40’. g'imonh! = 46°. m ht! = 137° 20. mm’ on h! = 93° 0’ to 93° 40’. h'm (left) = 136° 25’; and 135° 40’ (?). gi m’ = 134° 0’; and 134° 40°. mm’ ong! = 88° 40’. Meunier finds this meteorite to be identical, as regards composition, with that which fell at Tadjera, near Sétif, Algiers (1867, June 9th), in which also he recognised the presence of this variety of enstatite. (See page 595.) 594 Dr. Walter Fight—History of Meteorites. 1867, January 19th.—Saonlod, 3 Miles N. of Khettree, Sheka- wattie, Rajputana, India. [ Lat. 28° 9’ 45” N.; Long. 75° 51’ 20’ E. | ' A shower of stones, numbering about forty, fell near the village ~ of Saonlod on the above day, at 9 a.m. The morning was bright and clear, and no clouds were to be seen, when a loud report, resem- bling that of a cannon, was heard over an area many miles in length and iredehe and was picecoded by two still louder, and followed in turn by “a regular roll, resembling musketry heard at a short dis- tance.” The terrified inhabitants of the village where the stones fell, seeing in them the instruments of vengeance of an offended deity, set about gathering all they could find, and, having pounded them to powder, scattered them to the winds. A gentleman connected with the Topographical Survey, who happened at the time to be a few miles distant from Saonlod, states that he sent all the sowars attached to his camp to scour the country, with the intention of procuring as many of the stones as possible. He adds: “I was very nearly too late, as, between them all, they only managed to get the piece I sent, . and that under promise of a large reward.” According to the description, given by the more respectable class of natives, some of the meteorites were of the size of a 24-pounder shot, and had a blackish appearance on the outside; they fell with such velocity that they sank two or three feet into the ground in a sandy soil. The stone has a nearly black crust, cellular on the surface and corrugated somewhat longitudinally, and is about one-third of a millimetre in thickness. The interior has a light bluish-grey colour in some parts, and a much darker grey in others; the two portions lie side by side like two strata in some places, while in others a nodule of the one is seen to be enclosed in the other. The freshly fractured surface is studded with metallic particles of nickel-iron, and exhibits translucent granules of a greenish yellow, which are probably olivine. Siliceous spherules, as well as cavities once occu- pied by them, are also observed, and when the mineral is finely powdered and examined under water with a lens, the lighter portion of the stone exhibits a considerable quantity of nearly white crys- talline particles, mixed with small angular fragments of black, brownish, greenish yellow, and opaque minerals, as well as rounded particles of nickel-iron; the dark-grey portion has very. much the same appearance. The meteorite is not very hard ; the specific gravity of some small pieces of the light-coloured por tion was 3° 743, of the dark-coloured variety 3°612, while analysis showed it to consist of : Nickel-iron ... .. cee Maser. nove (LSS Troilite and schreibersite Beat seas tthetedy One Solublevsilicate™ 2.59 ce. 0 e.c eee ees TOOul8 Insoluble silicate... ... se. 0 eo 42°36 i 101°31 The metallic portion contains : Tron = 91:54; Nickel = 6:79; Cobalt = 1:15; Chromium = 0°52. Total = 100-00. ' D. Waldie. Jour, Asiat. Soc. Bengal, 1869, xxxviil. 252.—Records Geol. Survey India, 1870, ii. 101; 1870, iii. 10. - Dr. Walter Flight—History of Meteorites. 595 The sulphide and phosphide are assumed by the author to con- sist of : : Tron = 61°54; Sulphur = 33°71; and Iron = 12:46; Phosphorus = 2°29, Total = 100-00. He regards the iron sulphide “as Fe,S,, troilite,” a view which is hardly tenable in face of the fact that Dr. L. Smith and Rammels- berg, who have analysed the nodules of the mineral, which occur in the meteorites of Knoxville, Seelasgen and Sevier Co., Tennessee, have shown it to be a monosulphide. Again, no schreibersite has yet been met with which does not contain a very considerable per- centage of nickel, the whole of which metal the author takes to be present in the metallic ingredient. The siliceous portions separated by treatment with acid and sodium carbonate have the following composition : SiO. Al,0,Cr,0; FeO MeO CaO Na,O X} A. Soluble... 30°50 1:17 — 21°35 39:11 1:93 0:26 5:68 = 100-00 B. Insoluble ... 57:67 3°22 0:95 862 28:70 400 1:842 — = 100-00 While the soluble portion appears to be chiefly olivine, that which resisted the action of acid may be taken to be bronzite, together with a few per cent. of a felspathic ingredient, possibly labradorite. The Khettree meteorite, in point of composition, resembles that which fell at Klein-Wenden, near Nordhausen, Prussia (1848, Sep- tember 16th). 1867, June 9th.—Tadjera, near Sétif, Province of Constatine, Algiers.’ A meteor was seen to traverse the sky over this district, and two stones, weighing 5:76 and 1:70 kilog., fell near Sétif. The siliceous portion of the stone has a black colour which distinguishes it from most meteorites, and it is further remarkable for the absence of the usual fused crust. It has a specific gravity of 3:°595 and the follow- ing composition : INickel=inomWessh ieecan seseeeeniete metOnO2 Troilites.c4 views fysseuw ced 4 see vast 8°04 Chromiteyyercc ces eee eae ORL) Soluble silicate ... ... ... «. 54°64 Insoluble silicate... ... ... .«. 28°80 100-00 The nickel-iron consists of: Tron = 91:6; Nickel = 8:4. Total = 100-0. and the siliceous portions separated with acid and sodium carbonate : SiO, Al,0; Cr0; FeO MgO CaO Na,O A. Soluble... 40°24 0°81 — 11:17 42°78 — trace 100-00 B. Insoluble ... 50°21 4:15 0°41 27°99 8-03 9:21 trace = 100-00 In the soluble portion the silicic acid is in excess of that required to 1 Constituents removed with sodium carbonate, but undetermined. 2 With trace of potash. 3 §. Meunier. Thése présentée 4 la Faculté des Sciences de Paris, 1869. Re- cherches sur la Composition et la Structure des Meétéorites, 13. Compt. rend., 1871, xxii. 339. Cosmos, March 28th, 1866, 7.—See also G. A. Daubrée. Compt. rend., 1868, Ixvi. 513. Cosmos, March 21st, 1868, 25. 596 Dr. Walter Fliight—Mistory of Meteorites. - form olivine, in the insoluble part of that required to form bronzite; in the latter case a portion of the acid is probably present as a con- stituent of a felspar. 1868, February 29th.—Villanova di Casale Monferrato, Province of Alessandria, and Motta dei Conti, Province of Novara, Italy.! The village of Villanova lies on the left bank of the Po, 5 kilo- metres N.E. of Casale Monferrato and 2 kilometres from the village Motta dei Conti. Between 10:30 and 10:45 a.m. (local mean time) on the 29th February, the sky being calm but cloudy with cirri, cirro-cumuli and cumuli, a loud detonation was heard which was noticed in many villages and towns of this part of Piedmont. In Casale the noise resembled the discharge of artillery or the explosion of a mine; while an observer stationed near the confluence of the Sesia and the Po states that he heard a crackling noise like the dis- charge of musketry afar off. Near Casteggio, in the district of Voghera, Alessandria, a mass was observed to traverse the heavens with great rapidity, leaving a black track resembling smoke ; and two explosions were heard followed by a prolonged noise. A medical man who was near Santo Stefano d’Aveto, in the district of Chiavari, Genoa, saw a globe of fire of considerable size cross the sky from N.W. to S.H. at the same time. One meteorite fell about 600 metres S.E. of Villanova; it crashed through the branches of a tree and entered the ground a few paces distant from a terrified peasant, who, believing it to be a bomb, fell on his face. The villagers were filled with alarm at the occurrence, and some oxen yoked to a plough near Roggia Marcora stood still with fear. The stone penetrated the clayey soil to a depth of 0-4 metre, and on the following day was exhumed by a boy, while the courageous owner of the field sheltered himself securely hard by and watched the operation.? The Villanova meteorite has somewhat the form of a cube and measures 0-08 metre along the side; it weighs 1-92 kilog. and has a specific gravity = 3°29. It is covered with a thin hard brown crust ; the interior has a mottled grey colour and a fractured appearance, and is very friable. The matrix is stated to enclose grains of an ochrey-yellow hue, others much larger and of a brown colour (chromite), as. well as lustrous metallic particles, the remainder. con- sisting of various stony ingredients, some consisting of microscopic crystals. 1 A. Goiran, A Bertolio, A. Zannetti, and L. Musso. Sopra gli Aeroliti caduti il giorno 29 febbraio 1868 nel territorio di Villanova e Motta dei Conti, Piemonte, circondario di Casale. Con Introduzione del padre Denza. 1868, Torino. See also Bull. meteor. dell’ Osserv. del R. Ooll. Carlo Alberti in Montcalieri, March to June, 1868.—F. Denza. Compt. rend., 1868, lxvii. 322.—G. Jervis. I Tesori Sotterranei dell’ Italia. Parte Prima. 1873, Torino: Loescher. Page 153. 2 The trajectory of this stone could be approximately determined since three points in a vertical plane were determined: 1) the point where it grazed the top of a tree, 2) the broken end of the bough of a walnut tree severed by the meteorite, and 3) the point where it entered the ground. Other peasants, who were employed lopping trees near the high road which leads from Casale to Vercelli, at a point about 1200 metres from Villanova, observed a rain of black grains; one man was struck on the hat with a piece of considerable size. Dr. Walter Flight—History of Meteorites. 597 According to Bertolio this arahearte consists of : iron! Ws. EEL aAeMM wane seats ecall icone seme 2Ou00 Nickdhoxiden ica 4 ert. weckurt eee mee) Osoul Manganese and copper sae ots aig) E50") con | IIS Sulphur... ete mcr emery. “CUOUs Phosphoric Beta oF ge MACOS ONS Sd, 3089507 Chlorine eeep-ee eames isso e-e eeene Onto SiliciCacidieeam ssi -emine see nes eeonntewen OCLC! Alumina... Sack Bere STs pie sat Beso: Ly O41. Chromium sesquioxide Beh ene ayig ath moe i Os 000 ERO TORONOSTGIS Gos ca, 606 con 0 cod oc WB Maoniestasarran ket eee eee messitesce piece eh aql dO Lime ... ner aba piesas hesoy) coo, Beem Potash and ‘soda = 1g Se esueo aideie nee ete Roseup ee ay to! 99:°427 A second stone, weighing 6°311 kilog., fell in a cornfield near the farm Roletta at a spot 2350 metres distant from the first. In form it somewhat resembles a truncated pyramid, and measures 0-223 metre in its greatest length and 0:14 metre in its greatest breadth ; it also is covered with a thin crust, evidently the result of fusion. It is preserved in the Natural History Museum of the University of Turin. The authors of the paper above alluded to consider the two Villanova stones to be distinct meteorites, and not fragments. resulting from the explosion of a single mass during its passage through our atmosphere ; their opinion is shared by Denza. At the same time a meteorite fell at Motta dei Conti, the village already referred to. It struck.the pavement in front of a tavern with great violence, driving the slab 0-5 cm. into the ground, and the shattered fragments rebounded over the roof of a small dwelling 7 metres high ; their united weight is estimated to have been from 300 to 500 grammes. According to the list of the specimens, quoted by Jervis as preserved in collections, their total weight does not exceed 30 grammes. Bertolio, who submitted a small portion of the Motta dei Conti stone to examination, declares it to differ both in ~ physical characters and chemical composition from the Villanova meteorites; the disparity, however, is not difficult to account for. He finds this stone to be more magnetic and dense (specific gravity = 3-76) than the others, and to contain no lime and scarcely a trace of alumina. A fragment of a meteorite, containing nearly one quarter of its weight of nickel-iron would, during the rough treat- ment to which this stone was subjected, lose much of the interstitial rocky matter and acquire a greater density in consequence, while the proportion of the two oxides in the Villanova is in any case so small that the indications they may give in a qualitative examination of so small a quantity of material could hardly warrant our drawing a conclusion as to whether or no it had a common origin with, or similar constitution to, the Villanova stones. All the remaining ingredients of the latter are likewise found in the Motta dei Conti meteorite. It is stated that a fourth stone fell further north in the water of the Roggia Marcova, in the parish of Caresana. Daubrée points out that the above meteorites do not essentially 598 Dr. Walter Fiight— History of Meteorites. differ from others which have fallen in Piedmont during the first half of the present century at Cereseto (1840, July 17th), and at Guiliana Vecchio (1860, February 2nd); and finds them very similar in characters to the meteorites which fell at Oviédo, Spain (1856, August 5th), and in the Commune des Ormes, Yonne, France (1857, October Ist). 1868, March 20th.—Daniel’s Kuil, N.N.E. of Griqua Town, Griqua Territory, South Africa.! This meteorite fell near a Griqua at Daniel’s Kuil, who picked it up while warm; he gave it to Captain Nicolas Waterboer, the Griqua Chief, from whom Gregory obtained it. It was broken into two parts when it reached his hands, and has since unfortunately been divided into several more ; it weighed 2lb. 50z. The crust _has a dull black colour; immediately below it for a thickness of about {th of an inch the stone has a browner colour than the in- terior, the result of oxidation. The rock has a dark grey colour and a fine granular texture, and encloses a very considerable amount of nickel-iron in a finely divided condition, as well as particles of troilite and schreibersite. The rounded grains so commonly pre- sent in meteoric rock are not seen. This meteorite has been examined by Church, who finds it to possess the specific ene 3°657 to 3°678, and the following com- position : Nickel-iron Moe DART Ae LEER BON a ets Bese NOD, Oi, Troilite ISAS PE AREAS a SEE EER Bs 6°02 Schreibersitesy Gt Moslvel cost Seal oseeases 1:59 Silica and Silicates ... soo BLOGS Carbon, Oxygen, other constituents, ‘and loss 114 100:00 The nickel-iron contains : Tron = 94:72; Nickel = 5-18. Total = 100-00. The per-centage of troilite is based on a sulphur determination made in a separate portion; the schreibersite “was approximately esti- mated by calculating its amount as being ten times that of the un- oxidised phosphorus in the stone’”—a novel method which can hardly be considered a satisfactory one. The rocky portion of the stone, constituting nearly two-thirds of the mass, does not appear to have been submitted to detailed analysis, although we are told that the silicates consist chiefly of olivine and labradorite, ‘‘ the former species constituting by far the larger portion of the powder unaffected by dilute acids.” Olivine, as is well known, is the meteoric silicate par excellence which is broken up by such reagents, being easily acted upon even by dilute hydrochloric acid. Church does not state whether he succeeded in detecting the presence of alumina in this meteorite, although he numbers labradorite among its constituent minerals; while the occurrence of silica, as such, in a meteorite is so very rare, having as yet been isolated and submitted to analysis in one instance 1 A.H. Church. Jour. Chem. Soc., 1869 [2], vii. 22. Jou. Prakt. Chem., 1869, cvi. 379.—See also J. R. Gregory, Gzox, Maa. Vol. V. p- 531. Dr. Walter Flight—History of Meteorites. 599 only (see p. 551), that an investigation of this question is desirable. The author further states that in a second portion of the same sample he found the silicates to amount to 61:10 per cent., in another fragment to 48-99 per cent.; while in yet another portion the nickel-iron, judging from the per-centage of nickel it contained, constituted 39-20 per cent. of the stone. Found April, 1868.—Losttown (24 miles §.W. of), Cherokee Co., Georgia." According to Shepard’s first notice, this block of iron has the form of a human foot and weighs 6lbs. 100z. ‘‘ Widmannstiittian figures are visible directly in one portion of the surface ;” those presented by treatment with acid are stated to be very beautiful and to most nearly resemble the figures of the Seneca Lake iron. The nickel, which in the first notice is stated to be abundantly present, although the development of the figures would not lead one to expect the per- centage to be large, proved on analysis to be considerably below the average, as the following composition shows : Tron =95°759 ; Nickel =3-660; Insoluble portion=0°580. Total=99-999. The insoluble part is stated to consist of schreibersite and rhabdite ; traces of cobalt, chromium magnesium, and tin (?) were detected. The specific gravity of the iron is 7°52. 1868, July 11th.—Ornans, Doubs, France.’ This meteorite is described as differing in appearance from any of the stones which have fallen in Europe during recent times. It has a dull grey colour, and is so friable that it can be crumbled between the fingers. It is very porous; a fragment immersed in water ab- sorbed about 5th of its weight of water in two hours. Particles of iron can only be detected here and there with a lens, and the stone is feebly magnetic. 'The specific gravity of the rock is 3-599, and it consists of : Nickel-iron ... ... ... ... 1°85 Magnetic pyrites ... -... ... 6°81 Chromitem estes ieee 0:40 Olivine ees eee ane eee Oko) Insoluble silicate .... ... ... 15°26 99°42 The portions of silicate separated by the treatment with acid were : $10. Al,03; FeO NiO MgO CaO K,O and Na,O A. Soluble...... 33°37 3:93 30°76 3°83 26°37 1-74 — = 100-00 B. Insoluble ...40°43 8-98 10°55 — 3015 6:29 3°60 = 100-00 Pisani, it will be seen, is of opinion that a portion of the nickel is present in the form of oxide in the silicate which gelatinises with acid. He determined the amount of iron present as metal by measuring the volume of hydrogen which it evolved 1€.U. Shepard. Amer. Jour. Sc., 1869, xlvii. 284.—See also Amer. Jour. Se., 1868, xlvi. 257. 2 F. Pisani. Compt. rend., 1868, lxvii. 663.—G. Tschermak. Sitzber. Ak. Wiss. Wien, 1870, lxii. 855. 600 Dr. Walter Flight—History of Meteorites. during its solution in acid. In calculating the results of his analysis he considers the sulphur to be combined with a portion of this iron in the form of magnetic pyrites, and the remainder of that metal to be alloyed with some of the nickel, the excess of the nickel above that required to form the normal alloy being present as oxide. As, however, it has not been shown to be a com- ponent of the silicate, and recent researches (see page 315) have failed to prove that it forms a constituent of meteoric olivine, it may be present as alloy. If we exclude the oxygen of this nickel oxide, the ratio of the oxygen of the silicic acid to that of the total bases of that portion is 13°35 : 13-43, from which it appears that the chief constituent of the Ornans meteorite is an olivine having the formula 2 (3 Mg 2 Fe) SiO,. Tschermak finds that the dull grey eoloue: of this stone is due, at least in part, to the presence of carbonaceous matter. (Compare with Goalpara meteorite, page 605:) Bede, September 7th.—Sauguis-St.-Etienne, Canton de Tardets, Arrondissement Maulcon, Basses-Pyrénées.' ne 2°30 a.m. a meteor emitting a pale green light traversed the sky over Mauléon, and broke up leaving a faint whitish.cloud which lasted for some time. Its disappearance was succeeded by a noise as of thunder, followed by three or four loud detonations, which were heard over an area 80 kilometres wide. The inhabitants of Sauguis- St.-Ktienne heard, in addition to these noises, a sound like that j pro- duced by quenching hot iron in water, and a dull thud caused by the meteorite striking the ground. It fell about 30 metres from the church in the bed of a small stream, and was so completely shattered that the largest fragments did not measure more than 5 cm. in length; their total weight is about 2 kilog. The fall was witnessed by two men, who, returning home late, had continued in conversation at the door of one of their dwellings. Frightened by the hissing noise, they fell on the ground, and saw the stone strike the earth about 20 metres from them. The Sauguis meteorite consists chiefly of rocky matter, the metallic grains being small and sparsely distributed; troilite is noticed in nodules, some of which are 10 mm. across. The crust is dull black and possesses the unusual thickness of 1 mm.; the fine black veins observed to traverse certain meteoric rocks are abundantly present in this stone. A microscopic section was found to act strongly on polarised light, and to have the appearance of a breccia of very small transparent and colourless particles. Daubrée finds the rock composing this meteorite to be identical in all respects with that forming the stones which fell at aoa di Casale in Piedmont (1868, February 29th) [see page 596] ; practised eye examining specimens of these two falls would fail i distinguish one from the other. 1G. A. Daubrée. Compt. rend. 1868, lxvii. 873.—S. Meunier. Thése presentée a la Faculté des Sciences de Paris, 1869. Recherches sur la Composition et la Strue- ture des Metéorites, 16. : ; Dr. Walter Flight—History of Meteorites. 601 According to Meunier this stone has a specific gravity = 3°369,' and consists of : INickel=ironeqeeeeee ee omeee tees eine ase e000 Troilite Se al caged once ut anaes eae Goce. & CORO LE Solublersilicatele sae aee eee eae eee OZ O9, Insoluble silicate ARE Ae Re te ace Coane (al 100:574 The nickel-iron contains : Tron = 93°88; Nickel 6°12. Total = 100-00. and the portions of the silicate separated by treatment with acid and sodium carbonate: SiO, Al,0, & Fe2.0, Cr,0,; FeO MgO CaO K,0 Na,0 USE SLCC L, A. Soluble...... 45°66 = — 3:05 50°68 — 0°61 trace= 100-00 B. Insoluble... 61:96 2°56 0:05 8:49 24:62 2:12 0:20 — = 100-00 In both portions the silicic acid is considerably in excess of that required to form a silicate of the form of olivine in A, and of a bronzite in B. The amount of iron protoxide in the portion which gelatinised with acid is unusually small. Meunier refers to this meteorite in his description of the stone which fell at St. Denis-Westrem, near Ghent (1855, June 7th). (See p. 500.) 1868, October 17th.—Lodran, Mooltan, India.? This meteorite fell at 2 p.m. on the above day, the descent being accompanied with a loud explosion, which appeared to come from the east. The chondritic structure noticed in many meteorites was not observed in this stone, but enclosed within its black crust was found a magma of siliceous particles of so coarse-grained a cha- racter that the individual granules occasionally measured 2 mm. in diameter. The constituent minerals were carefully isolated before analysis, which showed the stone to consist of : INickelinoni ieee tacel Mase iGestie kita cca eclenato 210. Magnetic pyrites coo on cow, cc Olivine ee : coo ashe) Bronzite, with some chromite and anorthite. 31-2 100-0 The alloy, an important ingredient, which developes figures re- sembling those of the Senegal iron, forms a mesh-work enclosing the silicates, the crystals of olivine not unfrequently leaving a com- plete impression of their faces in it; it has the following. com- position : Tron=85°44; Nickel=12-79; Magnesia=0°25; Residue=0°81. Total=99-29. Associated with the substance just mentioned and occasionally en- tangled in the silicates were fragments of magnetic pyrites: they possess no crystalline structure and dissolve in acid with deposition of sulphur. The olivine is of a bluish grey to Prussian blue colour, 1 In his paper on the Belgian meteorite, a specific gravity = 3-48 is given. 2G. Tschermak. Sitzber. Ak. Wiss. Wien, 1870, \xi. 465. Pogg. Ann., cxl. 321. —Records of the Geological Survey of India, yol. 1. part 1, page 20. 602 Dr. Walter Flght—History of Meteorites. and occurs in unusually well-developed crystals, which have been found by von Lang to agree in all respects with the olivine from basalt ; the following measurements were made : on Calculated. 100s 1107) = 65302 tn 5 ee 65° 2" MO = 49 49 yd 49 57 100,210 = About 46 30 ..... ° 47 2 100,310 = SOM OO Ta ll tal ietirascrrte 35 36 100,210. = AP OTONA Uli tiey e ree 40 27 The fissures of many of the crystals are filled with a black mineral of a dendritic form; this is assumed to be chromite and is believed to be a secondary formation. This silicate has the specific gravity 3°307 and the following composition : Silicichacidiey-e sa eee 40-14 Chromium oxide ... ... ss. ... 0°60 TONE PrOLOXIde Meroe ecctaca Mee mTOD WIEST, 9 3065) 450 God Goo, con HEROINE 100-30 These numbers differ only to a slight extent from those of an olivine in which the two compounds Mg, SiO, and Fe, SiO, are in the ratio of 82: 18. The bronzite occurs in grains and imperfect crystals, on any of which faces of more than one zone are rarely recognisable. On one crystal von Lang determined the following angles: Calculated. 100, 320 = About 34° 50’ ...... 34° 30’ 100,110 = Ady Gu wan trea ee 45 52 100,230 = 57 15 sadee 57 6 : 100,130 = About 71 56 ....... 12 & while a second gave the following numbers: ’ Calculated. TORO) = ANG! Ba Lime eee 44° 8’ OLOF ALO =—F About 4400 2a 44 8 The calculated angles are based on observations made on the bronzite of the Breitenbach siderolite (see page 549). The plane of the optic axes is parallel to the zone [110, 010] and the mean line perpendicular to 010 has a negative optical character. The specific gravity of this mineral is 3°313 and the composition : Siliciclactdiaress MerstilessUilcciii--ane Dons ANITIIINES G60 00. cod, ods ae UD ron¥protoxidemeyee. Mees ecs ital ule WikyernVeey 5o4" G66 db Goo) con WE) Aime Fics. 2 foun = Hovey taecsmeece = teeent OTS 101°51 which corresponds, in point of constitution, with a bronzite in which the isomorphous compounds Mg SiO, and Fe SiO, are present in the ratio 78 : 22. When a microscopic section of this mineral is examined it is found to enclose three substances: 1) colourless chondra of a doubly re- fracting mineral, which the crossed Nicols show to be twinned, and which is probably a felspar; 2) small round black particles, usually lying in groups, and believed to be chromite; and 3) fine hair-like Dr. Walter Flight—History of Meteorites. 603 bodies, disposed parallel to the cleavage-planes ; their nature could not be determined. The plate accompanying Tschermak’s paper furnishes drawings of all these substances. In addition to the octahedral faces (111) von Lang observed on the chromite crystals faces of the rhombic dodecahedron (110) and the leucitoid (311), and made the following measurements : Caleulated. 111, 111 = 70° 381’ cod 00 000 70° 32’ O11, 131 — 3l 25 a Vanes eal ol 29 131,113 = 650 25 MRO oa: he OSr 329 1868, November 27th.—Danville, Alabama. [Lat. 34° 30’ N.; Long. 87° 0’ W. |’ During the (American) war, writes Dr. Laurence Smith, artillery had often been heard in the valley of the Tennessee, and various specu- lations were indulged in as to the meaning of a loud report, like that of a cannon, which occurred at about 5 p.m. on the day above mentioned, and appeared to come from a direction northward of Danville. On the following day a man brought to that town a piece of rock which, he said, fell near him and some labourers who were picking cotton at a place 3 miles W. of Danville. It entered the soil to a depth of 14 to 2 feet, and when exhumed was found to weigh about 44 lbs. Several stones fell in the neighbourhood; one near some negroes at work in a cotton-field, two others whizzed right and left past two men who were ploughing a field about 12 miles N.W. of Danville. The meteorite which reached Dr. Smith’s hands, the first of those mentioned, has the usual black crust, which is rough and dull, and appears in some parts to have been whipped round, as it were, and rolled over the border on to the unfused surface as the stone tra- versed the atmosphere. A fresh surface has a dark grey colour, and is less chondritic than is the case with many meteorites, and there are veins or patches of a slate-coloured mineral running across it. Iron sulphide and nickel- iron are diffused through the rock, the latter more especially in the slate-coloured areas; and there are occasional white patches of what is probably enstatite. The meteorite has a specific gravity of 3°398, and contains 3:092 per cent. of nickel-iron consisting of: Tron =89°513; Nickel = 9-050; Cobalt=0-521 ; Phosphorus=0-019; Sulphur= 0-105; Copper, trace. Total=99-208. and the iron sulphide contains : Tron=61-11; Sulphur=39°56. Total=100-67. If the excess over 100 be deducted from the iron, the chief con- stituent, these numbers correspond very closely with the per-cent- ages of magnetic pyrites (pyrrhotite), not with iron protosulphide, as stated in this paper ; troilite, the presence or absence of which 1 J. L. Smith. Amer. Jour. Sc., 1870, xlix. 90, - 604 Dr. Walter Fhght—fMistory of Meteorites. was not established, is of course the monosulphide. The rocky por- tion of the Danville meteorite consists of : Solublevsilicatemunsaeeceaeeennt ee rea OURSO n'solubletsilica tes meee eee eon ae mle 100-00 and has the following composition : Si02 Al,0, Cr.0; FeO MnO MgO CaO KO Na.O 8S P A. Soluble.. 45°90 1°73 trace 28°64 trace 2652 2°31 0°64 0°51 1:01 trace =102-26 B. Insoluble 50°08 4:11 — 19°85 — 20:14 390 — -— — — = 98-08 In the soluble portion the excess over 100 is due to some of the iron regarded as oxide being present in combination with sulphur ; this portion is chiefly olivine, that insoluble in acid is bronzite with a little augite or felspar. The author finds this meteorite to be similar in every respect to the stone which fell in Harrison Co., Indiana (1859, March 28th), which in many catalogues is incorrectly referred to Harrison Co., Kentucky (1859, March 26th). 1868, December 5th.—Frankfort, Franklin Co., Alabama.! The fall of this meteorite, which occurred at 3 p.m. on the above day, was attended by three loud reports, immediately succeeded by a series of sounds like that of a great fire blazing and crackling. The descent took place four miles S. of Frankfort, and was witnessed by Mr. J. W. Hooper, who saw the stone strike some willow saplings about 70 or 80 yards from him; on going to the spot, he found it nearly buried in the ground and still warm. The noise of the explosion was heard 20 or 25 miles E. and W. and 15 or 20 N. of Frankfort. Mr. Hooper made notes of the occurrence, and sent the stone for analytical examination. “He refused with scorn money offers, which must have been tempting to a person of limited income, pre- ferring the advancement of science to dollars and cents.” The meteorite, which is almost entirely covered with a very lus- trous black crust, so thin in some parts that fragments of olivine can be distinguished through it, weighs 615 grammes, and has a specific gravity of 8:31. A fractured surface presents a pseudo-porphyritic structure, having a grey ground on which black, green, white and dark grey spots are seen : the black fragments are very lustrous and slightly magnetic (chromite); and the yellowish-green mineral, passing into yellow and shading into dark grey, appears to be olivine; while the greyer variety cannot, according to Brush, be distinguished from the “ piddingtonite”’ of the Shalka stone, now shown to be no true mineral species (see page 405). Some brilliant points possessing metallic lustre were found to be troilite; and one or two delicate black veins were also observed. The nickel-iron constitutes only a few hundredths of one per cent., the chromite 0-62 per cent., and the troilite 0-63 per cent. of the 1G, J. Brush, Amer. Jour. Sc., 1869, xlvii. 240. Dr. Walter Flight—Mistory of Meteorites. 605 mass; and of the latter about 26 per cent. is soluble in acid. An analysis of a portion of the stone gave the following results: Oxygen. Dilicichacidweaecsniss )aschuecsm Oless am 26°37 PAULINA se sc) este uess) BOIOO nee 3°78 Chromiumioxide... ... ... ... O42 Imoniprotoxide 75. ... ... =» 3270 nec 3:04) NIQSMESE) cos Goo poe) 6op ce) FE 7:04 | GMC Peers gin scs Soe ahasey e cccke GOO eee 2:06 }+12°28 Potash Seiedvi ide] s\ vase of Abbeville, and Dr. Rigolott,° at Amiens, carried on their own separate lines of research, which, however, did not result in attracting public attention until after 1858, when the exploration of the Brixham cave stimulated scientific men to take 1 « Account of an Assemblage of Animals discovered in a Cave at Kirkdale, York- shire,’ 1821, Phil. Trans. vol. exii. p. 171; and “‘ Rekiguie Diluviane,’ 1826, 4to. Lond. 2 Edinb. Phil. Journ. vol. xiv. p. 205. 3 McEnery’s MS., written in 1824, was not published until 1859, by Mr. Vivian, and more fully by Mr. Pengelly, “‘ Literature of Kent’s Cavern,” Devonshire Asso- ciation, 1868-9. 4 Recherches sur les Ossemens Foss. dans les Cavernes de la Proy. de Liége, 4to. Atlas and folio, 1833-34. 5 “ Antiquités Celtiques,’ 1847, vol. i. ® Comptes Rendus, 1847, p. 649; 1864, p. 230. "NUSQOVHAAVHOS NOLNV)) ‘NUDNIVH], YVAN ‘AAV HOOTUUISSayY AHL WOUd NALLNY UAdaNlay NO ONIAVYONY GaSIONT "AX “Td ‘II ‘TOA “JI Favoaq ‘SHIMAS MAN C/o “DVN “10a Reviews—Reliquie Aguitanice. 611 up and carefully work out this latest of geological periods which stretches to the border-line of Archeology. When once these researches became known to the world by the writings of Lyell, Prestwich, Falconer, Lubbock, Pengelly, Evans, Lartet and Christy, Boyd-Dawkins and Sanford, Dupont, and many others, it seemed as if the scientific men of every nation had only been waiting some signal to announce their varied discoveries in this field of Prehistoric Archeology. Thus we simultaneously heard of the discovery of ancient settle- ments built upon piles in the Swiss Lakes; of Crannoges in the Trish Bogs; of Peat-mosses with abundant relics in Bronze and Stone in Denmark; of shell-mounds and refuse-heaps; of River- valley gravels with flint implements ; of ossiferous caverns and rock- shelters in many countries, but notably in England, France and Belgium. Upon none of these investigations has a larger share of careful and laborious research been bestowed than that which the authors of the Reliquie Aquitanice’ have devoted to the task of exploring the Caves of the Vézére; but of its two authors, Henry Christy did not live to see the issue of the first part,? whilst M. Edouard Lartet® died 28th January, 1871, after the completion of the tenth Part. The task of carrying out the intentions of Mr. Henry Christy as regards the publication of the results of his explorations, and those of his colleague M. Edouard Lartet, has been ably and generously fulfilled by Mr. Christy’s brothers; the direction of the work having been entrusted to the care of M. Penguilly l’Haridon, Mr. John Evans, F.R.S., Pres. Geol. Soc. Lond., Mr. A. W. Franks, F.R.S., Dir. §.A., Mr. W. Tipping, F.S.A., and Professor T. Rupert Jones, F.R.S., F.G.S., the last-named gentleman having throughout fulfilled the duties of Editor. How well that task has been fulfilled, and how carefully and diligently, and lovingly too, each contributor has added of his store, and how all this has been built in and cemented together by the able Editor, Prof. Rupert Jones, let the 580 pages of text (with their accompanying 87 plates and 135 engravings and woodcuts) which complete the work, testify. Monuments have been erected in all times, of wood, of clay, of stone, of ivory, iron, silver, and gold, but we doubt whether any monument was ever before reared in paper to two fellow-workers 1 Reliquie Aquitanice ; being Contributions to the Archeology and Paleontology of Périgord and the Adjoining Provinces of Southern France, by Edouard Lartet and Henry Christy. Edited by Thomas Rupert Jones, F.R.S., F.GS., etc., Professor of Geology, Royal Military and Staff Colleges, Sandhurst. Complete in Seventeen Parts, comprising pp. 530, 4to. Illustrated by 87 plates, 3 maps, and 132 woodcuts. London: 1865-75. H. Bailliére, Publisher. The “‘ Reliquie Aquitanice”’ has been already noticed in the Grotocican MaGa- ZINE for 1866, pp. 76 and 462; 1867, p. 321; 1868, p. 282; 1869, pp. 24, 277, 4638; 1870, p. 174; 1873, p. 96. 2 See Obituary Notice in Grou. Mac. 1865, Vol. II. p. 286. Mr. Henry Christy died 4th May, 1865. 3 See Obituary Notice by Pres. Geol. Soc. in Quart. Journ. Geol. Soc., 1872, vol. xxviii. Ann, Address, p. xlv. 612 Reviews—Reliquie Aquitanice. in science ; yet this volume will probably outlast many of the more ponderous and barbaric structures of the past, and prove a source of knowledge to all who consult its pages. The Caves and Rock-shelters containing the Aquitanian relics treated of in this work are excavated in cliffs of Cretaceous Lime- stone along the lower portion of the valley of the Vézére; indeed for nearly thirty miles they form both on the Vézére and its many tributaries those nearly precipitous escarpments which have been in all ages excavated by natural agencies and the hand of man into galleries, recesses, and caverns. ‘These ossiferous caves (whether or not enlarged artificially) have been hollowed out originally by atmospheric agency, the softer bands of limestone having been more readily acted upon by frost and other agencies than the harder beds. The uppermost of these limestones is characterized by the presence of Rudistes (Spherulites, Radiolites, Hippurites). The second zone is a Polyzoan Limestone with shells, Echinoderms, and the claws of a Crustacean (Callianassa) like that of the Maestricht beds. The flint occurs as a chert band often containing Polyzoa, Orbitoides, and even fish-teeth (Otodus). The Caves described are those of Les Eyzies, La Madelaine, Gorge d’Enfer, Cro-Magnon, Le Moustier, besides numerous rock-shelters at Laugerie Haute, and Laugerie Basse, ete. Although coming within the age of simply-worked stone, without the accompaniment of domestic animals, these caves are by no means on a uniform level as regards the products of human industry. In only three stations (namely, Les Hyzies, Laugerie Basse, and La Madelaine) have figures of animals engraved or sculptured on stone, on bone, or on reindeer-horn, been met with. At Laugerie Haute lance-heads of flint were found in abundance, whilst arrow- heads or harpoon-heads of reindeer-horn were almost entirely absent, although plentiful at Laugerie Basse and at La Madelaine. ‘The Cave of Moustier has yielded even more rude and primitive flint-weapons than any, but not a single worked bone or engraved or sculptured figure of any animal. Nevertheless the fauna of the several stations appears to be almost the same. If we eliminate from the following list the names of certain animals (which in these caves are represented by single fragments of bone or a tooth) such as the Mammoth, the Cave-lion, the Hyzna, and the great Cave-bear, we have seven stations, of perhaps various ages, but all in the Reindeer and Wild-horse Period. These animals, as in the Cave of Bruniquel, on the Aveyron, were evidently the principal objects of the chase, and their remains make up by far the larger bulk of the osseous fragments left in the cave-dwellings. It is reasonable to assume that the Reindeer went North in sum- mer, and at that season probably herds of Wild-horses took their place, retiring further South than the Reindeer in winter. The Musk-ox (Ovibos moschatus) was probably also a winter visit- ant; at any rate two portraits have been found of it, carved on bone harpoons (one from Bruniquel, and one from Kesslerloch, near Thiiingen, Canton Schaffhausen, in Switzerland); and its bones have also been found in two caves of the Vézére. Te ee ed een itigapeaabasall a a —— Reviews—Reliquie Aquitanice. 613 ~The following is a list of the various animals whose remains have been met with in the seven stations explored by Messrs. Lartet and Christy :— 3 o ; Siu lee serie kere leees ; w ‘S| 3 3 += =| £ ‘s A 5 | a Ss =~ is & a 5) mn Oo o o 4S &D a =] ro I oo o 3 BS iS) SI a ra) © | ‘Sl = = bo S bo 1 =) i=] Hw fo} m o 3 3 s i=} = o 4 | 4 4 o) s) | Mus maiscrvls, OWeU. ccessrsssssscrsssssescsnnesesees x Arvicola, sp. be Spermophilus, sp. x erythrogenoides, Fale... x Lepus timidris, Linn. vcceccsssccsssescessseesssnneesss x x x x x x CUTCOPALILDG, MUO 5 coconcnoncerorenconnncecketee xe 2 Elephas primigentus, BOM. .sccsseseeen x x aK x x¢ x LEGO CHOTA, TAIN ceeesccocececoncn crcepo erertoeeo x K x x x x SOS GEO Coy LUACA De cccecocencconcncr ecco: eeen ERE x x Bison priscus, BOJADUS, .......sccsvseeeecseeneee x x x {BOS SSP it wie Bernat ccseac cee ee SU x x x xs x Ovibos moschatus, Pallas, .rcecccsecsssscseree x x Capnaxbcr Minne see x x x x x x PAIL UOPE I UIDUCOION Dyn neecrasteces sestracteee te x x xx GH Gis RAMAN ccrreenes reteertaceretoccatnecean x x Cervus elaphus, LADD. veces x x x x x x tarandus, Linn. ...... x xe x x xe x x megaceros, OWED, ws x JEg IS Sota (CeO Bl cconosceneedeccensceomncoreonccteenecen x x x Ely enaspel@an GOldiae ee eee x Canis lupus, LAND. veces x x x x x >< WU LO CSB TSS renee As cet et reales a eee x x x ox x x Gulo luscus, Linn. (An engraving on | SYOYAN) etna eae he eae Aa Onsusispeleus. lume ee eee ee x x x Number of Human remains discovered 1 | 4 5 No labour or expense has been spared in bringing together in aid of the elucidation of the Prehistoric Archeology of Aquitania, not only all points relating to the manners, customs and implements of modern savages, but also all objects from other caves likely to aid these researches. Mr. Lloyd’s notes on the Reindeer of Newfoundland, contained in the last part of the “ Reliquiw,” are most valuable as throwing great light on the habits of this ancient and widely-distributed Northern type. We reproduce from page 279 of the “ Reliquie Aquitanice” (by permission) in our Plate the incised figure of a Reindeer, cut on a piece of Reindeer antler, from the Kesslerloch, a Cave, or Rock- shelter near Thaingen, Canton of Schaffhausen, Switzerland. This is probably one of the best examples of incised outline figures on bone metwith in any cave, and well deserves careful study. (See Plate XV.) The one-holed Baton, Pogamagan, or Arrow-straightener (broken), which bears this remarkable engraving, is figured in the “ Mittheil. Antiq. Gesellsch. Zurich,” vol. xix. Heft 1, 1875, pl. 8, fig. 68, among the many interesting illustrations of Herr Konrad Merk’s 614 Reviews—The Arctic Manual. memoir, “The Cave-find in the Kesslerloch,” ete. We are glad to be able to announce that Mr. John EH. Lee, F.S.A., F.G.S., is about to re-publish this Swiss work as an English book with all the plates. EXPLANATION OF PLATE XY. Incised outline of a Reindeer on a piece of the round shaft of a Reindeer antler from the Kesslerloch Cave or Rock-shelter near Thaingen, Canton of Schaff- hausen (natural size). The surface of the cylindrical and engraved piece of antler is here shown as if extended open :— A, A, the side with the figure of the Reindeer ; B, B, the other side bearing incised marks, probably representing herbage and water. a, a, mark a line between the two sides of the engraved antler. IJ.—Manvat or Narurat History, GroLogy, AND PHystcs; AND Instructions For THE Arctic Exprpition, 1875. 8vo. pp. 86 and 783. (London: Eyre & Spottiswoode.) First Norrce. EW fields of geographical discovery, indeed few branches of scientific research, have either excited such abiding interest or had such an ancient and continuous history as that of Arctic Ex- peditions. The difficulties that lie in the way of explorers in the more northern seas, and the ignorance which necessarily exists as to the geographical and meteorological phenomena of the unknown area surrounding the North Pole, have been incentives to other nations besides our own to solve the mysteries of the Arctic Regions. The voyage of the Polaris, under Captain Hall, and that of the Germania in 1869-70, under Koldewey, were both evidences that the spirit of arctic discovery was by no means dead; but since the expedition of Sir Leopold McClintock in the Fox, in search of the missing crews of Franklin’s ships in 1857-9, no important effort has been made under the auspices of the English Government to make one more attempt to penetrate the unknown lands, and set at rest, if possible, the eager spirit of scientific inquiry which lies at the foundation of such researches. The discoveries of the Polaris and Germania, however, seem to have aroused anew the desire of the English nation not to be behind- hand in the great work. At the close of 1874 the Government decided to take the matter in hand, and by its powerful assistance enable an expedition to be despatched, which should, from its careful and complete preparation, depart on its mission under better auspices and with greater chance of success than had fallen to the lot of any previous squadron. The Alert and Discovery were therefore purchased and prepared, strengthened and fitted with every modern appliance which could either lessen the difficulties or lead to the success of the object in view, not merely the planting of the British flag on the northern axis of the earth, but to increase the knowledge of the Physical Geo- graphy of the Arctic regions, and add, therefore, to the scientific knowledge of the world. Recent voyages had led to the conjecture that the path offering the Reviews—The Arctie Manual. 615 greatest chances of success in the effort to reach the Pole was by the long, narrow, area of water which bounds the Western Coast of Greenland, known as Smith’s Sound. The President and Council of the Royal Society were informed by a letter from the Secretary of the Admiralty, dated 4th Dec. 1874, that it was their Lordships’ intention to despatch an expedi- tion, in the spring of 1875, to endeavour to reach the North Pole, and to explore the coast of Greenland and adjacent lands, and were invited to offer any suggestions which “might appear to them desirable in regard to carrying out the scientific conduct of the voyage.” The result of this appeal is the volume of some 800 pages to which we purpose calling attention. It is divided into two separate and distinct sections: (1) Instruc- tions for future Observations, compiled under the direction of a Committee of the Royal Society; and (2) A Manual of Scientific Results already obtained in previous Arctic Expeditions, edited by Professor T. Rupert Jones, F.R.S. (who himself prepared the part relating to Zoology, Botany, Geology, and Mineralogy), and assisted by Professor W. G. Adams, F.R.S., who compiled the part relating to Physics. Both sections are prepared with exceeding care; and the second part, or ‘‘ Manual,” contains the most complete and perfect collection of the most important information extant on the scientific researches in the Arctic Seas. The first section, which is further subdivided into two parts, deals first with Astronomy, Terrestrial Magnetism, Meteorology, Atmo- spheric Electricity, Optics, etc., and secondly with Zoology, Botany, Geology, and Mineralogy; but it must be understood that this section of the book is designed solely to point out what information is required, and also the best means of obtaining it. ‘Thus the early sections refer chiefly to the methods of obtaining local mean time and so on from eclipses, the necessity for repeated and accurate tidal observations, as well as the detection of the cosmical dust found frequently in the snow of northern regions, and which, being composed of iron and nickel, points to a meteoric or non-terrestrial origin. The declination, inclination, and intensity of the earth’s terrestrial magnetism, whereby the “knowledge of the distribution of the magnetic force over the earth’s surface” may be determined, may lead to valuable results, contributing towards the perfection of our knowledge of terrestrial magnetism. The instruments requisite for these determinations, as well as the order in which observations should be made, are hence referred to, and the importance of this subject, as dealing with compass variations and the consequent security of iron shipping, needs no comment. In fact, the whole of the first section deals rather with suggestions than with known facts, and details the manipulation of instruments for Meteorological and Atmospheric, Electrical as well as Optical and Spectroscopic observations, providing also technical maps bear- ing on some of the subjects. 616 Reviews—The Arctic Manual. Under the head of Miscellaneous Observations are some valuable remarks and suggestions by Dr. Rae and Professor Tyndall. The former deals with the salinity of ice, and the kinds which are most useful as a source of water-supply for drinking purposes, and points out that it is possible to procure “almost always” good drinking water from “wasted old ice,” which must not be con- founded with “rotten ice,’ as the latter is spongy, comparatively thin, saline, and unsafe to travel on, while the former breaks into detached floes when quite thick and solid. This rotten ice is worn away whilst in situ by sea-currents acting on its under surface; while the upper, owing to the low temperature of the air, is not affected ; but it was suggested by Dr. R. Brown that this alteration may further be due to the accumulation of Diatomaceze below the surface, which would tend to increase the local heat and be there- fore perhaps another cause of the phenomenon to which Dr. Rae refers. Be the cause what it may, the fact itself is of considerable importance whew the water-supply in an ice-bound region fails, and the determination of that kind of ice whence good water could be obtained is not merely interesting, but might be of considerable utility to those vessels which frequent the Northern seas. Professor Tyndall’s remarks, suggested by his own laborious re- searches, call especial attention to the formation of snow crystals and the rapidity of the conduction of heat through ice, and the action of the great Arctic glaciers. It is still a disputed point whether the icebergs are formed by the uplifting action of the water when the ice mass projects into the sea, in which case the surface being in a state of longitudinal compression, and therefore devoid of crevasses, or by the gravity of the overhanging end, when such fissures must naturally be formed. Some suggestive remarks on the method of determining the range of sound conclude the paper, to which Prof. Tyndall has appended copies of his valuable papers on the “ Physical Properties of Ice,” the “Atmosphere as a Vehicle of Sound,” and “Forms of Water,” which will doubtless furnish many important hints to those who accompany the Expedition. Part II. of the first section of the book is devoted to Biology (Zoology and Botany), and Geology and Mineralogy. The first portion is purely for guidance in collecting the Mammalia, Birds, Fishes, Crustacea, Mollusca, Polyzoa, Hydroids, etc.; and for the determination of the more important varieties careful lucid descriptions are given; while the various points of interest about which our knowledge is still imperfect are fully noted. The com- pleteness of this section, as a guide to, perhaps in some instances, inexperienced collectors, is very noticeable; and its value is en- hanced by a brief but pertinent paper by Professor Huxley, calling particular attention to Microscopic collections of various kinds, but particularly those which could lead to a comparison between the microscopic Fauna and Flora of the surface-waters of the sea and those of the sea-bottom, to be obtained by dredging from the same localities. The botanical section, by Dr. J. Dalton Hooker, consists of but Reviews—The Arctic Manual. 617 one paper, but contains all the necessary information for procuring and preserving the flowering plants, mosses, lichens, and fungi, as well as the fresh and salt-water algze of the Arctic regions ; and con- cludes with a reference to the excellent opportunities afforded to the naturalists of the Expedition for ‘‘ making observations on the power of seeds to resist cold whilst retaining their vitality.” Seeds of various sorts, such as mustard, cress, radish, turnip, pea, bean, etc., have been provided for such experiments. The ‘ Instructions” close with some twenty pages of excellent matter referring to practical work in geology, mineralogy, etc. The names of Ramsay, Evans, Story-Maskelyne, and Judd are sufficient evidence of the value and importance of this sub-division of the introductory matter. The instructions and suggestions would be useful to any one, and comprise not merely a list of the tools and stock required for collecting and preserving, but good sketches of inclined, contorted, and other strata, conformable and unconformable stratification, and the like. It is unnecessary to call attention to these suggestions in detail, as they are numerous and terse, and to make an abstract of them would be impossible. Special attention is, however, called to the want of information on the Oolitic fauna, similar to that of Cook’s Inlet discovered by McClintock in lat. 60°, and the Liassic fauna found both by Sir Edward Belcher and the Swedish Expedition in 78° 30’, and also whether a true Carbon- iferous flora occurs in any continental land or island, resembling that found in Bear Island. The examination geologically of the northern realms has hitherto been so very partial and incomplete, that a connected geological history is at present impossible. All that is really known is that a Miocene flora has been collected at Atanekerdluk and other places on the Waigat, at Disco, and Spitz- bergen, and that many great sheets of basaltic lava overlie the rocks containing the Miocene plants in many places. As the Miocene igneous rocks of the Faroes and Inner Hebrides occur in much the same way, and the true determination of the position of similar de- posits would not only throw “much light on the change of climate, but also on- the subject of a great continental extension of land during the Miocene Epoch into far northern regions, as suggested by Dr. Robert Brown.” There is an interesting subject for research, too, in the character of the Greenland glaciers, namely, that the underlying rocks are not grooved or striated (as far as we at present know), like the rocks which have been acted upon by old or modern glaciers in the Alps and elsewhere. This apparently arises from the fact that the whole of Greenland has been entirely covered by the glacier-ice, so that no moraine matter from exposed cliffs or peaks could get be- tween the ice-sheet and the underlying rocks, and act as agents for scoring or scratching the surface over which they were moved under _ great pressure. It is asserted, therefore, that the rocks are “ice- polished or ‘moutonnée,’ but not grooved or scratched ;” and it would be instructive to have accurate data on this point, so as to increase our knowledge of the action of glacier-ice under the exceptional conditions that obtain in Greenland. 618 Reviews—Dr. Barstow on Sulphurets. _ The opening chapter or chapters of the Arctic Instructions and Manual may therefore be summed up as a code of excellent rules for the guidance of the scientific observers of the Aleré and Discovery. They would certainly be most useful to those who, while fully con- versant with one particular branch of science, may not have pre- viously had the desire or opportunity of paying more than a passing attention to other branches. They would bring definitely before such an observer what to look for, and what to do when he had found the object of his search. As such they are useful and interesting to others besides the able observers of the Arctic Expedition. CuCa Ke II].—SuLPHURETS : WHAT THEY ARE, HOW CONCENTRATED, HOW ASSAYED, AND HOW WORKED. By W. Barstow, M.D. (San Francisco, A. Roman & Co.; London, Triibner & Co.) HIS little book is chiefly intended for the Californian miner, and its object is to present to the reader, in a simple and concise form, the nature and treatment of the Sulphides of the metals, so as to save him, to some extent, the trouble of wading through a series of expensive works in which the subject-matter is more fully treated. The metallic sulphides, or sulphurets, are an important group of mineral compounds; those which occur most abundantly in nature are the sulphides of antimony, mercury, silver, zinc, lead, copper, and iron. ‘Those of the latter are of most frequent occur- rence, and are the source of some of the gold. Most gold-bearing rocks are coloured by the oxyd of iron, and that oxyd is often plainly derived from decomposed pyrites, which is found very generally associated with gold, although not chemically combined with it. However, gold is often found in rock which not only contains no pyrites, but is also perfectly free from discolouration. The characters of the chief sulphides are very briefly described, too brief indeed to give their distinguishing characters. The second part gives a very concise account of assaying the sulphides, and also gold and silver, by the dry and wet methods. The third part describes the various processes and machines for separating the richer portions of the pulverised ore and other matters not desirable to work, and termed concentration; and the fourth part contains the different methods for the reduction of the sulphides, by which the metals they contain are extracted. The last part is devoted to a brief account of the different ores when assayed by means of the blowpipe, and their reactions with the various reagents to which they are submitted. It seems to have been the author’s wish to make this an introductory guide to the more extensive and elaborate works on the same subject. J. M. ' Reviews—Dollfus’s Geology. 619 IV.—GuipE to THE GroLocy or Lonpon anp THE NEIGHBOURHOOD. By Wixi1am Wuiraker, B.A., F.G.8. 8vo. pp. 72. (Geological Survey of England and Wales, London, 1875.) HIS little work is intended as an explanation of the Geological Survey Map of London and its environs, which was noticed in the Grotocican Macazrne for May last, page 231; and also of the Geological Model of London constructed under Mr. Whitaker’s superintendence (noticed in the Magazine for 1873, Vol. X. page 513), and now exhibited in the Survey Museum. The work is confined to a general account of the geology, as details have either been already published in Mr. Whitaker’s large memoir on the Geology of the London Basin, or will be given, so he states, in a future memoir on the drifts of that area. The lithological features of the various formations are described ; the leading fossils are mentioned; while the range, features, and scenery, are also briefly noticed; and lists of sections are given. The work is written very concisely and systematically, and from the number of interesting facts contained in it, it forms the best and most useful summary of London geology that has been published. It is probably the cheapest geological survey memoir for its size— the price being one shilling !—H. B. W. Y.—Prinoives pe Gfotocis TRANSFORMISTE, APPLICATION DE LA THforrE DEL’ Evoturion A LA Gronogiz. Par Gustave Douurus. 8vo. pp. 178. (Paris: Librairie F. Savy.) S may be seen from the title of this work, the endeavour of the author is, to extend the theory of evolution, hitherto confined to organic life alone, and to apply it to stratigraphical geology. This is not the first time that an attempt has been made to draw a parallel between the organic and inorganic world, nor is it in any way more successful than other such previous efforts. M. Dollfus commences by stating the opinions of, and quoting from the most eminent geologists, past and present, with respect to the fixity or non-fixity of species. In the second part, he briefly reviews each geological period, giving and commenting on the various opinions held concerning debated points; and especially remarking upon the modifications which the several faunas undergo in their passage upwards. With each formation is also given a table wherein the various beds of which it is composed in the different countries of Western Europe are, as far as possible, correlated. In the third part, under the heading “L’Espéce en Stratigraphie,” the author expresses his idea more clearly. This seems to be, that every bed, like an organized being, passes, so to speak, through certain phases of existence. Its deposition is its birth, it then undergoes a series of meta- morphoses until it reaches a stage in which it attains its full growth and ceases to alter. Thus Lignite passes into Coal and then Graphite; Limestone into semi-crystalline Limestone and then into saccharoid 620 Reports and Proceedings— Limestone. Finally it dies a natural death, being carried off by atmospheric or other agencies. Further on M. Dollfus gives the laws of Heckel, applying them as far as possible to his theory as well, which, owing to their nature, is easy ; and with the exception of the third he succeeds in making out a kind of analogy. He concludes with some broad reflections on the progress and future of Geology. We cannot, however, agree with the author either in his main point, or in several minor questions, which occur in the course of his ui Oi TS) -AINED) 2 2OC HD aN GS —— SSS GroLocican Society or Lonpon. Oprrninc Meretine, Session 1875-76.—November 38rd, 1875.— John Evans, Esq., V.P.R.S., President, in the Chair.—The following communications were read before the Society :— 1. “On some new Macrurous Crustacea from the Kimmeridge Clay of the Sub-Wealden Boring, Sussex, and from Boulogne-sur- Mer.” By Henry Woodward, Esq., F.R.S., F.G.S. The first species described by the author belonged to the fossorial family Thalassinide, six species of which belonging to four genera are now found on the British coasts. The known fossil species are from the Chalk of Maestricht, the Greensand of Bohemia and Silesia, the Chalk of Bohemia, the Greensand of Colin Glen, near Belfast, and the Upper Marine Series of Hempstead, Isle of Wight. All these are referred to the genus Callianassa, which also includes the species from the Kimmeridge Clay described in this paper. The fossil is seen in profile on several sections of the core, and has the enlarged hands of the fore-limbs more nearly equal in size than in the living species of Callianassa; the carapace and segments of the abdomen are smooth, and the latter are somewhat quadrate in profile, contracted at each extremity, and not pointed, and the caudal plates are oval. For this Crustacean the author proposes the name of Callianassa isochela. The second species described belongs to the genus Mecochirus, distinguished by the great length of the fore-limbs, which is equal to that of the whole body; the oldest known species of which (M. olifex, Quenst.) is from the Lower Lias of Wurttemberg. It was obtained, together with Lingula ovalis, from the Kimmeridge Clay of Boulogne, by Mr. J. E. H. Peyton, after whom the author pro- poses to name it M. Peyton. In this species the fore-legs are very finely punctate, and measure 75 millims. in length. The rostrum is somewhat produced, and the carapace, which is finely granulated, measures 30 millims. in length. ‘The antennz are long and slender. The abdomen measures 45 millims., and the epimeral borders of the segments are falcate. The species is intermediate in size between M. socialis, Mey., and M. Pearcei, McCoy, which the author regards as distinct. He also refers to M. Peytoni a pair of fore-limbs ob- tained from the Sub- Wealden boring. Geological Society of London. 621 2. “On a new Fossil Crab from the Tertiary of New Zealand.” By Henry Woodward, Esq., F.R.S., F.G.S. In this paper the author described a crab obtained by Dr. Hector, F.R.S., Director of the Geological Survey of New Zealand, from the ‘‘Passage-beds” of the Ototara series in Woodpecker Bay, Brighton, on the west coast of the south-island of New Zealand. The new species belongs to the genus Harpactocarcinus, A. Milne- Edw., which includes six species from the Eocene of southern Europe. Its nearest ally is H. quadrilobatus, Desmar., but its carapace is much more tumid, especially on the branchial and gastric regions; the surface of the anterior half of. the carapace is nearly smooth, and that of the posterior half finely granulated. The rostrum is short and very obtusely tricuspidate; the orbits shallow and rounded; the hepatic margin rounded and entire, with only a slight spine on the epibranchial angles; the divisions of the regions of the carapace are only faintly indicated; and there is a slightly roughened line on the sides of the gastric intumescence. The characters of the jawfeet and of the chele agree with those of the Cancride; of the latter the right is considerably larger than the left hand. The specimen was a female. For this species the author proposed the name of Harpactocarcinus tumidus. Dr. Hector explained the sequence of formations in the locality from which the above Crab was derived, and stated that the Ototara series is to be regarded as Cretaceo-Tertiary, containing some fossils of decidedly Cretaceous type, such as Saurian bones and fragmentary Inocerami, and other forms that are associated with decidedly Mesozoic fossils in the underlying strata. On the other hand, the occurrence of Tertiary forms such as Nautilus zic-zac (or a nearly allied form), the gigantic Penguin (Palgeudyptes antarcticus, Huxl.), and a Turtle, indicate a fauna not unlike that at present existing in the vicinity. 3. “Ona remarkable Fossil Orthopterous Insect from the Coal- measures of Britain.” By Henry Woodward, Hsq., F.R.S., F.G.S. The author commenced by indicating the importance of the ex- amination of the Clay-ironstone nodules of the Coal-measures, in which so many valuable fossils have been discovered, including the remarkable insect described in the present paper. The specimen displays the characters of the four wings, only two of which, how- ever, are nearly perfect, and these measure 2 inches in length and 1 inch and 1+ inch in breadth, the hind wing being the broadest. The author described in detail the characters presented by the vena- tion of the wings, which includes three straight veins running parallel to the fore margin, the third bifurcating near the apex, a fourth much curved vein giving origin to six branches, and having at its base a triangular space, from which arise the other veins of the wing. The body appears to have been about 5 lines broad be- tween the bases of the wings. In front of the wings is the protho- rax in the form of two large, rounded, dilated, and veined lobes; it measures 14 lines across and 6 lines in length. In front of these lobes is the head (with its eyes) produced in front into a slender pro- cess three lines long. This insect is considered by the author to be DECADE II.—YVOL II.—NO. XII. 40 622 Reports and Proceedings— most nearly related to the Mantide, the characters of the head and thorax especially being to some extent paralleled in the existing genus Blepharis. The author proposed to name the species Lithomantis carbonarius, and suggested that Gryllacris (Corydalis) Brongniarta probably belongs to the same genus. 4, “On the Discovery of a Fossil Scorpion in the English Coal- measures.” By Henry Woodward, Hsq., F.R.S., F.G.S. The author commenced by noticing the various Huropean and American localities in which fossil Arachnida have been found in the Coal-measures. Hitherto no true Scorpions have been recorded from the English Coal-measures; but in 1874 the author received from Dr. D. R. Rankin a specimen from the Coal-measures near Carluke, which he regarded as the fossil abdominal segment of a Scorpion; in April last he obtained (through Mr. Hy. Johnson, C.H., Dudley) a fossil Scorpion from the Sandwell Park Colliery ; and in August Mr. E. Wilson forwarded to him two specimens of similar nature in Clay-ironstone nodules from Skegby New Colliery, near Mansfield. The specimens are all very imperfect; but the author states that they most closely resemble an Indian form which is probably Scorpio afer. He refers the English species provisionally to the genus Hoscorpius, Meek and Worthen, and proposes to name it H. anglicus. Discusston.—Mr. Charlesworth inquired whether the few Cretaceous fossils found in the deposit which had furnished the New Zealand Crab described might not be the result of the degradation of pre-existing rocks. Dr. Hector replied that on stratigraphical grounds this could not be the case. Mr. Charlesworth stated that he had been unable to ascertain the precise locality of the fossil Orthopterous insect described, but that he was informed by the gentle- man from whom he received it that the nodule containing the specimen was picked up by a lady near Airdrie, Scotland. Prof. Morris remarked that the New Zealand Crab was of especial interest. All the previously described species of Harpactocarcinus had been obtained from Num- mulitic deposits in the south of Europe, and the same concurrence was observed in New Zealand. Similar phenomena occurred in Australia, where many species resem- bling European forms had been discovered by M‘Coy. Mr. Etheridge said that one of Mr. Woodward’s papers demonstrated the value of the Sub-Wealden boring. He had examined the cores, and had come to the con- clusion that the Oxford Clay was reached at 500 feet; but in this he was mistaken, owing to his having wrongly identified the Ammonite discovered at that depth with Ammonites Jason. The occurrence of the same species of Crustacean at Boulogne and in Sussex was of great interest, as marking the identity of the deposit in the two localities. Lingula ovalis occurred with other fossils throughout the Kimme- ridge Clay of the boring. ; Mr. Woodward thanked Mr. Charlesworth for his endeavours to ascertain the ~ locality from which his Lithomantis was obtained. There could, however, be no doubt as to its geological horizon. 5. “The Drift of Devon and Cornwall, its Origin, Correlation with that of the South-east of England, and Place in the Glacial Series.” By Thomas Belt, Hsq., F.G.S. The author described the general characters of the drift in the district under consideration, and stated that on the uplands the drift consists of undisturbed gravels and travelled boulders, which occur only in isolated remnants on the lower ranges, and that in the low- lands and valleys within 100 feet of the present level of the sea the Geological Society of London. : 623 gravels are widely spread, and show signs of sudden and tumultuous action. Between the upland and lowland gravels he considered that great denudation had taken place. He maintained that the boulders and the materials of the gravels had been distributed by floating ice, and that their presence on the summit of Dartmoor indicated that the water on which the ice floated must have extended up to 1200 feet above the present sea-level; but he argued that this water was not that of the sea, because no old sea-beaches or remains of marine organisms are to be found in the region, although fresh-water shells are preserved. He ascribed these phenomena to the presence of a great freshwater lake, produced by the drainage of Hurope being dammed back by a great glacier flowing from the north-west (Green- land) down the present bed of the Atlantic, and over the northern parts of the continent. The author discussed the characters of the superficial deposits in the southern and south-eastern counties, and indicated the points in which these seemed to bear out his hypothesis. The sequence of phenomena assumed by the author is as follows: —Accepting Mr. Tylor’s notion that the actual sea-level must have been lowered during the Glacial period in consequence of the great accumulation of water in the form of ice at the poles, he seeks a point of departure for the Glacial period in the first evidence of such a lowering of the sea-level. The Weybourne sands and the marine beds of Portland Bill were deposited when the sea was at about its’ present level, and the Bridlington Crag probably belongs to the same period. The fossils found in these deposits show that the waters were cold. The first stage of the Glacial period is that of the older Forest-beds, and the immigration of a number of great Mammalia and of Palzeolithic man indicates that the sea had retired from the British Channel and the German Ocean, leaving these islands con- nected with the continent. A great river probably ran southwards through the region now submerged. The second stage is marked by the continued advance of the ice from the north, the retreat of the southern fauna and Paleolithic man, and the arrival of Arctic Mammals. The third stage saw the culmination of the Glacial period and the greatest extent of the Atlantic glacier, which reached to the coast of Kurope, blocked up the English Channel, and caused the formation of an immense lake of freshwater by damming back the drainage of the whole of north-western Hurope, as already indi- cated. In the fourth stage the Atlantic glacier began to retreat, and the sudden breaking away of the barrier of ice that blocked up the mouth of the Channel caused the tumultuous discharge of the waters of the great lake, by which the spreading of the lowland gravels was effected. To this cause the author attributes the for- mation of the Middle Glacial sands and gravels of Norfolk and Suffolk. During the fifth stage the ice of the German Ocean con- tinued to retreat; but there was a temporary advance of the Atlantic glacier, which again blocked up the Channel, and produced a second great lake, which, however, did not attain so great a height as the first, and its waters were not discharged in the same tumultuous fashion. At this period the Upper Boulder-clay of Norfolk and 624 Reports and Proceedings— Suffolk was formed; but the author is not convinced that this formation is represented south of the Thames except by the “Trail” of the Rev. O. Fisher. In the sixth and last stage the Atlantic ice retreated as far as the north of Scotland, but the sea had not re- turned to its former level. The British Isles were connected with the continent and with each other. To this the author assigns the last great forest period, and the arrival of Neolithic man and the associated fauna from the continent. Discusstion.—Mr. Hicks stated that he had noticed that the glaciation at St. David’s is from the north-west. He had already stated before the Society his opinion that there had been depressions proceeding from a point in the Atlantic, probably not far from the coast of South America, to the north-west and north-east; and this might perhaps have something to do with causing a flow of ice from Green- land to the south-west in North America and to the south-east in Kurope. Rey. O. Fisher wished to know what would be the area of the great freshwater lake supposed to be produced by the damming action of the great Atlantic glacier. The Author stated that the area blocked up by the ice would be about 40,000 square miles (2000 x 200), and would include all the region drained by the present northern rivers. Prof. Hughes wished to know why the waters could not drain off by way of the Black Sea, and why the advancing Atlantic glacier should be supposed to stop just at the western point of Cornwall. He could discover no evidence of there ever having been a lake such as the author described. The drift gravels were the result of all the agencies of denudation which had ever been at work, and the boulders at the bottom of the low-ground drifts were probably due to the fall of débris from the summits. The boulders of the drift, if the author’s theory were true, ought to eonsist of Greenland rocks, whereas they were really of local origin. With regard to the direction of glaciation in Britain and Northern Europe being from the north- west, he could not agree with the author. In many places glaciation might be observed running in every direction; and it was not fair to note only certain strie, and neglect those which were not in favour of a foregone conclusion. He thought that Mr. Campbell had shown clearly that the glaciation of Ireland took place from the north-east. Mr. Mogeridge remarked that a very flat country extended across the continent of Europe from England to the Black Sea, and thought that in that direction there was no land sufficiently high to form the boundary of such a lake as that required by the author’s theory. ~ Rev. T. G. Bonney said that, in addition to the difficulties which Prof. Hughes had mentioned, four others at least occurred to him :—That the barrier to Mr. Belt’s lake was defective between the highlands of Brittany and the Auvergne; that the ice in its course from Greenland would have to cross a part of the Atlantic where the. depth approached 2000 fathoms, which seemed to demand an inconceivable accumulation in that country; and that under such circumstances Wales, Scotland, and Scandinavia must have had their own ice-systems ; and that to reach Scandinavia . (which certainly had its own ice-system), this great sheet must have crossed the Lofoten Islands, yet all the higher hills in these were remarkably sharp and broken. Further, in regard to what Mr. Belt had said about the lowering of the general level of the sea, it must be remembered that such an ice-cap would raise the level in the hemisphere where it occurred. The Author, in reply, said that he did not want the ice to stop at Cornwall, but that his statement as to its limits was founded on observed marks of glaciation. He thought the absence of marine remains throughout the drifts of the northern plains of Europe was a highly important and suggestive fact. With regard to the glacia- tion of Ireland, he remarked that the ice flowing south-east from Greenland would strike against the high lands of Scotland and England, and be turned back over Treland. The lowering of the sea was not absolutely required by the necessities of the paper; but if the accumulation of ice took place simultaneously at both poles, the sea must necessarily be greatly lowered. Correspondence—Ur. G. Poulett-Scrope. 625 CORRESPONDENCE. CUP-SHAPED JOINTS OF BASALTIC COLUMNS. Sir,—It is clear (from Mr. Mallet’s letter to you, see Guou. Mac. Nov. 1875, p. 566, and also from his communication to ‘“ Nature” of this date) that no facts which may be adduced can be regarded as of any value, if they discountenance a ‘cut-and-dried’ theory on which a ‘physicist’ has made up his mind. He contents himself with simply reasserting his theory, and resolutely refuses to examine the appearances presented by the fine group of columns in the Hall of the Geological Society, to which I have referred him, as being totally inconsistent with it. Mr. Mallet’s theory presupposed, in his own words, that “the convex surface of the joint” should “always point in the same direction as that from which the cooling and consequent splitting proceeded” (p. 182 of Proceedings of Royal Society, No. 158). I ventured to submit this supposition, which did not agree with my experience, to the test of “facts.” In the triple group of columns from the Giant’s Causeway in the possession of the Society, in which there is every reason to suppose the cooling and splitting had pro- ceeded throughout in one and the same direction, do the convex sur- faces of their joints all point in the same direction? I found them, on the contrary, pointing in different directions. Nay, even in one column an articulation of little thickness showed: two cup-shaped coneavities pointing different ways, back to back, like those of a bi-concave lens. Now how does Mr. Mallet attempt to get over this difficulty? Why, by supposing, or rather asserting as a fact proved by his theory, that the cooling process in this column pro- ceeded in opposite directions, from the top as well as the bottom, - and met in the interval between the two opposite concave joints— that interval being an articulation only a few inches thick, and showing no sign of seam or separation across it! But, in addition to the obvious improbability of this supposition, Mr. Mallet has himself disposed of it in the following passage (page 183, Proc. Royal Soc. No. 158): “If the mass cools both from the top and the bottom, the prisms, vertical and straight, will meet in an irregular interme- diate stratum of angular fragments.” I have already said that there is no appearance of any such inter- mediate fragmentary stratum within the very thin articulation in which Mr. Mallet, in order to save his theory, now chooses to place the separating plane between the portions cooled from above and from below. In addition to the evidence furnished by the column in the Society’s Museum, which, however, is quite conclusive on the question, I have the authority of my friend Mr. Judd, whose competency as an ob- server will not be disputed, for the fact that, in the platform of the Giant’s Causeway, as well as at Staffa, there are to be seen at least as many concavities as convexities. And even Mr. Mallet will scarcely deny that in all these columns the cooling must have pro- ceeded in the same direction; namely, from below upwards. Indeed 626 _ Correspondence—Ur. C. Moore. the very regular columnar ranges, to which Mr. Mallet’s theory relates, have, one and all, evidently cooled from the bottom; the upper portions of the basaltic beds being nearly amorphous, or, if prismatic at all, composed of very imperfect groups of prisms. Apart, indeed, from Mr. Mallet’s ideal columns, I will state, as the result of my own observations, that in every natural section of a basaltic columnar range, the plane separating the portion in which cooling probably began below from that in which cooling began at the upper surface, is, as a general rule, horizontal; the two portions being as distinct as is the architrave in a Greek temple from the supporting columns (as may be seen in any good drawing of Staffa, or of the basaltic columnar ranges of the Vivarais, Auvergne, etc.). The upper portion is, indeed, generally amorphous, or nearly so, and so decidedly separated from the lower regular columnar range, as to have been usually mistaken for a separate lava-flow of later forma- tion. If Mr. Mallet’s notion could be realized anywhere, it would be in the horizontal columns of a vertical dyke, formed by contem- poraneous cooling from both of its sides. I will, however, venture to say that no instance can be produced of a single continuous column passing unbroken, from side to side, of any dyke. Can Mr. Mallet produce any example of such a fact from his own observations ? The columns, on the contrary, always terminate towards the centre — of the dyke, either in a seam of amorphous lava, or an interval filled with rubble (and this Mr. Mallet himself admits, as in the former instance, p. 183), or sometimes they are separated by a still more recent vein of lava. Finally, I leave it to all geologists interested in the question, to examine the columns in the possession of their Society, and form their own opinion upon the point in dispute be- tween Mr. Mallet and myself. It is of the more importance from its having an"indirect bearing on the main question as to the influence of concretion, no less than of simple contraction, upon the production of the columns themselves : a question upon which, likewise, I have the misfortune to differ with Mr. R. Mallet, who will not admit of any concretionary action at all —even, for example, in the case of the nearly globular articulations of the prisms of the Cheese-Cellar at Bortrich. But upon this point, I will not here enlarge. Cosuam, November 3rd, 1875. G. Pounztrr Scrope. ON THE PRESENCE OF THE GENERA PZICATOCRINUS, COTYLE- DERMA AND SOLANOCRINUS IN BRITISH STRATA. Sir,—At the British Association Meeting a few weeks since, F. Longe, Esq., F.G.S., of Cheltenham, handed to me a very perfect example of the interesting but little known Crinoid Plicatocrinus which had been found by him on the coast near Bridport. He informed me he had shown it to Dr. Wright, who had referred it to the family Cirripedia, to which at first sight it bears some resemblance. I explained to Mr. Longe that this was incorrect, as it belonged to the Crinoidea, at which group Dr. Wright had so long been work- ing, and that I was already possessed of several of the above genera Obituary—W. Sanders, F.B.S. 627 and species from the same geological horizon as those previously found on the Continent. A notice of these appears in my paper on “Abnormal Conditions,” etc., p. 480 of the Journal of the Geol. Society for 1867. Mr. Longe with much liberality presented me with the specimen. After this I showed it to Dr. Wright, and pointed out to him the zoological position that had been assigned to it by continental geolo- gists, and in reply to his inquiries informed him that the best figures and description would be found in a paper by Dr. Deslongchamps of Caen. Dr. Wright lost no time in referring to Dr. Deslongchamps’ de- scription, for in a note to me on another subject, he remarks: “ As I am always on the look out for any new facts to chronicle in relation to my own subject; I sent a short notice of Mr. Longe’s discovery to the GrotoetcaL Macazrne, and herewith inclose you a separate text.” In this he quotes the history of Cotylederma as given by Dr. Deslongchamps, but makes no reference to the conversation I had with him respecting it. At this time I had no opportunity of seeing Dr. Deslongchamps’ memoir, or comparing the specimen with those in my museum. On my return home I found it belonged to the genus Plicatocrinus, and not to Cotylederma as I had first supposed. Had I been aware Dr. Wright intended sending a notice of the specimen for publication, I could at once have corrected the error. From his remark in the last paragraph that “it is the first English specimen of this curious form of the Liassic sea which I have yet seen from our Lias beds,” he does not appear to be aware of its pre- vious discovery by myself, though on one occasion, if I mistake not, I called his attention to examples in my museum, where they have been publicly exhibited. T took with me to the Bristol Meeting a beautiful specimen of the genus Solanocrinus I have lately found in Oolitic strata, and now first recorded as a British genus, but withheld a notice of it in order to have drawings prepared of Mr. Longe’s Plicatocrinus. Batu, Oct. 25, 1875. Cuartes Moore. OS ea UeAS Een —_@—_ WILLIAM SANDERS, F.R.S. Death has removed another of the small band of distinguished geologists that commenced their career when the science they cultivated and elucidated was yet in its infancy. The late Mr. William Sanders, F.R.S., was a native of Bristol, and for upwards of forty years of his life was intimately associated with the most distinguished names that have enriched geological science. He devoted his life to the study of the physical structure of the Bristol area, and early in his scientific career was the friend and companion of Prof. Phillips in his Geological Survey of North Devon and Cornwall, which occupied some years. His chief labour, 628 Obituary— W. Sanders, F\R.S. however, and that by which his name will ever be remembered, was the preparation and construction of an elaborate geological map of the area comprised within the Gloucestershire and Somersetshire Coal-field. The scale of this map is four inches to the mile (four times the scale of the Ordnance Map), and the detailed geological structure of the entire area was conscientiously and-carefully worked out. The labour devoted to this map by Mr. Sanders extended over fifteen years, and the work occupies nineteen folio sheets geo- logically coloured, and the physical details added. Sir Henry de la Beche and Professor Phillips in days long gone by urged upon Mr. Sanders the importance of constructing a map upon such a scale that the complicated structure of the Bristol Coal- Field should be so clearly expressed that its mineral wealth should be better understood and appreciated. It may be truly said that no man single-handed ever constructed such an exact geological map for any area. Associated with this map should be mentioned another original and lasting labour by Mr. Sanders, viz. the measured sec- tions of the extensive cuttings (delineated to scale) of the Bristol and Exeter Railway from Pyle Mill, Bristol, to Uphill on the Mendips, and the line from Bristol to Bath, in both of which the smallest details are laid down, whether of Physical or Paleontological value. Their value remains undiminished, although done thirty-five years ago. ; Few there are who can appreciate the patient labour, ability, and mental culture required to carry out and complete so extended a survey over so complicated a region. These labours, however, added to his other acquirements, made his scientific reputation and enriched his native city. Mr. Sanders rendered great service to Bristol in connection with the water-supply through his intimate knowledge of the water-bearing strata and resources in the Mendip area, and also during the survey of the city with reference to its sanitary condition : facts little known to those outside the world of science, and who have not, like Mr. Sanders, patiently pursued a line of study and research much in advance of their fellow-citizens. He was an ardent student in mineralogy, and few were more accomplished in crystallography. He mastered its mathematical details in the elaborate treatises of Brooke and Miller, Dana, and Naumann. Mr. Sanders was elected a Fellow of the Royal Society in 1864. For upwards of thirty years he held the office of honorary secretary to the Museum of Natural History attached to the Philosophical Society and Institution of Bristol. He spared neither time, trouble, nor expense to carry out its legitimate objects. Mr. Sanders’ labours and researches have contributed in no small degree to the develop- ment of geological science, and the sheets of his large map formed the basis upon which the materials accumulated by the Royal Coal Commission relative to the Gloucestershire and Somersetshire Coal- fields were represented. His name will ever be associated with the labours of the great and good in science, and those who knew him best will most deeply mourn his loss. R. EH. EN DEX. ABS BSENCE of Life in Deep. Sea, 88. Abstract of Geology of India, by Prof. Duncan, 419. Action of Denuding Agencies, 433. Aitken, J., Observations on Distribution of Drift, 517. Alcyonaria, Fossil, from Tertiary of New Zealand, 424; from Australia, 424, Alder, M. B., Bottleite, 570.. Allport, 8., Classification and Nomen- clature of Rocks, 583. Ancient Rocks near St. Davids, Pem- brokeshire, 93. Animal Life in Deep Sea, Presence, Ab- sence of, 88. Arctic Expedition, 1875, Instructions for, 614. Artesian Well at Torquay, 96. Arthur’s Seat, Edmburgh, Structure and Age of, 182. Asar, Esker, or Kaims, G. H. Kinahan, 86. Axis of a Dinosaur from Wealden of Brook, by Prof. H. G. Seeley, 382. ose eae W., Sulphurets: What they are, 618. Basaltic Columns, Cup-shaped joints of, 566, 625. Batrachia, Discovery of, Paleozoic, France, 506. Bell, A., New Land-shell from Gault of Folkestone, 240. Belt, T., Drift of Devon and Cornwall, 622. in Upper Bentham, Prof., On Fossil Mimose, 230. Birds, J. A., Post-Pliocene Formations, Isle of Man, 80, 428; Postscript to, 226. Blake, Rev. J. F., Kimmeridge Clay of England, 135. Blanford, H. F., Age and Correlation of Plant-bearing Series of India, 134. Bone-Bed near Frome, Rheetic, 96. DECADE II1.— VOL. 11.—NO XII. CON. Bone-Caves near Castleton, Derbyshire, 184; Cave in Creswell Crags, 512. Bonney, T. G., Glacial Erosion, 426 ; 524. Boring Mollusca in Oolitic Rocks, 267. Bottleite, 570. Boulders and Drifts of the Eden Valley, 547. Boulder-Clay in Ireland, 524, 568. Brady, H. B., Fossil Foraminifera from Sumatra, 532. Bristow, H. W., Deep-Boring in Prussia, 95. British Association at Bristol, List of Papers read before Section C, 521. Burnley Coal-field, Geology of, 272. Busti Meteorite, 141. (ALLIANA SSA isochela, H.W oodw. from.the Sub- Wealden Boring, 620. Cambridge Gault and Greensand, 136. Cape of Good Hope, Diamonds from the, 646, Carboniferous Fossils, On some Unde- scribed, 241. Carpenter, Dr., Animal Life in Deep Sea, 88. Castracane, Count A. F., Diatomacee in Carboniferous Period, 414. Cave-Dwellers of Aquitania, Relics of, 610. Central Sumatra, Geology of, 417. Chetetes, On some Massive Forms of, 175. Chesil-Bank, Origin of, 228. Church, Prof. A. H., Specific Gravity of Precious Stones, 320; Red Chalk, Hunstanton, 331. Classification and Nomenclature of Rocks, 583. Coal, Search for, under Red Rocks of Staffordshire, 193. Collins, J. H., Formation of a Mineral-~ ogical Society, 569. Considerable Fault in Lias near Rugby, 273. 4] 630 CON Contéjean’s Hléments de Géologie et Paléontologie, 421. Corals, Fossil, from Tasmanian Tertiary, , New, from Carboniferous Lime- stone, 273. , Devonian, of N. America, 30. Corrélation des Formations Cambriennes de Belgique et Pays de Galles, 42. Correlation of Deposits in Cefn and Pontnewydd, 519. Cotylederma, Discovery of, in Middle Lias, Dorsetshire, 505. Coums, Corries or Cirques, Origin of, 486. Crab, New Fossil, from Tertiary, New Zealand, 621. Cretaceous Aporrhaide, 139, 392. Cretaceous Rocks of England, 281. Cross, Rev. J. E., Geology of North- West Lincolnshire, 47. Crutwell, A. E., Great Rhetic Bone Bed near Frome, 96. Cruziana semiplicata, 274. Culm-Flora of Moravian Silesian Slates, 564, Cystiphyllum, New Species from De- vonian Rocks, North America, 30. Deine S, J. R., Sediment Theory of Drift, 168. , and Ward, J. C., Voleanic Rocks of Lake Country, 95. Dana’s Manual of Geology, Review of, 44. Daubrée, M., Formation of Metallic Sulphides in a Thermal Spring, 507; On Native Platinum of the Urals, 561. Davies, W., British Museum, 432. , D. C., Phosphorite Deposits of North Wales, 183. Dawkins, Prof. W. Boyd, Mammalia found at Windy Knoll, 184. Dawson, Principal, Occurrence of Fozoon Canadense at Cote St. Pierre, 334; Superficial Geology of Central North America, 515. Denudation of the Weald, 282, 336. Denuding Agents, 433. Deep-Boring in Prussia, 48, 95, 140. Delesse and de Lapparent’s Revue de Géologie, 45. Deshayes, Prof. G. P., Obituary Notice of, 430. Dewalque, Prof. G., Corrélation des For- mations Cambriennes de Belgique et Pays de Galles, 42. Diamonds from Cape of Good Hope, Notes on, 545. Diatomacee in Carboniferous Period, 414." Dinosaur, Axis of a, 382. Discovery of Fossil Scorpion in English Coal-measures, 622. Index. GEO Dollfuss, G., Principes de Géologie Transformiste, 619. Drift, The- Sediment Theory of, 168; —- Erroneous Nomenclature of, 328,547. —— Observations on Unequal Distribu- tion of, 517. — Of Devon and Cornwall, 622. Duncan, Prof., Abstract of Geology of India, 419; Fossil Aleyonaria from Tertiary of Australia, 424; Fossil Alcyonaria from Tertiary of New Zealand, 424; Fossil Corals from Tasmanian Tertiary, 425. CONOMIC Geology, Dr. Page on,130. Edwards, F. E., Obituary Notice of, 570. Eléments de Géologie et Paléontologie, 421. England and France in Glacial Epoch, 48, English Jurassic Foraminifera, Lists of. 308. Eoscorpius anglicus, from the Coal Measures, 622. Hozoon Canadense at Cote St. Pierre, 334. Etheridge, R., New Species of Genus Hemipatagus, 289; Undescribed Car- Doniferous Fossils, 241. AVISTELLA stellataand Favistella calicina, 279. Femur of Cryptosaurus humerus, 92. Fisher, Rev. O., Uniformity and Vulcan- icity, 97; Submerged Forests, 283 ; Remarks on Mallet’s Theory of Vol- canic Energy, 335. Flight, Dr. W., A Chapter in the History of Meteorites, 16, 70, 115, 152, 214, 257, 311, 362, 401, 497, 548, 589. Foraminifera, Fossil, from Sumatra, 532. Fossil Forest in Coal-measures at Wadsley, 278. Foster, C. Le N., Notes on Haytor Iron Mine, 513. Frome, Bone-bed near, 96. ABB, W. M., Notes on West Indian Fossils, 544. Gardner, J. S., Gault Aporrhaide, 49, 124,198,291; Cretaceous Apyorrhaide, 392. Gasteropoda of Guelph Formation of Canada, 514. Gaudry, Prof. A., Discovery of Batrachia in Upper Paleozoic Rocks, France, 506. Gault Aporrhaide, 49, 124, 198, 291. and Greensand, Cambridge, 136. Geological Notes from New York, 520. Geological Society of London, 46, 92, 132, 182, 233, 273, 334, 381, 429, 510, 620. Geological Action of Ice, Questions con- cerning, 191. y Index. GEO Geological Survey of India, 524, 572. Victoria, 562. Geology, Dana’s Manual, Review of, 44. Geology and Races of India, 379. Glacial Epoch, England and France, 48; in Southern Hemisphere, 580. Erosion, 328, 356, 426, 524. Period, Cause of, with Reference to British Isles, 578. Goodchild, J. G., Glacial Erosion, 323, 306; Origin of Coums, Corries or Cirques, 486 ; ‘“Wultenite”’ at ‘“ Uald- beck Fell,” 565. Granitoid and Metamorphie Rocks of Lake-District, 518. Graptolites of Arenig and Llandeilo Rocks, 182; Distribution of, in Lower Ludlow Rocks, 560. Greensand and Gault, Cambridge, 136. Greenwood, Col. G., Submerged Forests, 239; Denudation of theWeald, 282; on Glacial Erosion, 524. 5: Guelph Limestones of North America, 343. Guide to Geology of London and Neigh- bourhood, 619. ~ Guppy, J. L., Supplement to Paper on West-Indian Tertiary Fossils, 41. ARDMAN,E.T.,Goodchild’s Theory ef Sub-Glacial Formation of Gravels, 172. Harpactocarcinus tumidus, H. Woodw., from New Zealand, 621. Haytor Iron Mine, Notes on, 513. Hemipatagus, Desor, Deseription of New Species, 239. Henwood, W.J., Obituary Notice of,431. Hicks, H., Succession of Ancient Rocks near St. Davids, 93; Occurrence of Phosphates in Cambrian Rocks, 237; ' Physical Conditions of Deposit of Cambrian Rocks, 510. Hinde, G. J., Description of new Tabu- late Coral, 514. Hopkinson, J., Graptolites of Arenig and Llandeilo Rocks, 1382; Distribution of Graptolites in Lower Ludlow Rocks, | 060. Horne, J., Post-Pliocene Formations of Isle of Man, 329. Hulke, J. W., Modified Form’ of Dino- saurian Ilium, 424. Hull, Prof. E., Boulder-clay in Ireland, 524, Oe Volcanic Dust of Barbadoes, 287. Hutton, Capt., Glacial Epoch in South- ern Hemisphere, 580. Huxley, Prof., Stagonolepis Robertsoni and Evolution of Crocodilia, 275. 631 LEO CE Action, 121. — Cap, 613. Indian Geological Survey, 572. India, Geology of, 419. ——, Plant-bearing beds of, 134. Inverted Strata of the Mendips, 566. Trish Glacial Drifts, Birds on, 189. Isle of Man, Post-Pliocene Formations of, 80, 329, 428; Postscript to, 226. OHNSON, M. H., Structure of Phos- phatic Nodules from Bala Limestone, 238. Jones, Prof. T. R., Newly-exposed Sec- tions of Woolwich and Reading Beds, 234; Notes on some Sarsden Stones, 588. — Sumatran Fossils, Note on, 532. and Prof. W. Parker, Lists of English Jurassic Foraminifera, 308. Judd, J. W., Contributions to Study of Volcanos, 1, 56, 145, 206, 245, 298, 348, 388; Structure and Age of Arthur’s Seat, 182. Jukes-Brown, A. J., On Cambridge Gault and Greensand, 136. EEPING, W., Neocomian Sands with Phosphatie Nodules at Brickhill, 372; Notes on Paleozoic Kchini, 424. Ketley, C., Search for Coal under Red Rocks of Staffordshire, 1938. Kinahan, G. H., Asar, Esker or Kaims, 86; OnValleys in Relation to Fissures, 131; Deep-Boring_in Prussia, 140; on Oscillations of Sea-level, 141; on Trish Glacial Drifts, 189; Red Rocks of Tyrone and Derry, 287; Erroneous Nomenclature of Drift, 328, 547; Nomenclature of Rocks, 425; Boulder- clay in Ireland, 568. Kimmeridge Clay of England, 136. ABYRINTHODONT from the Coal- measures, 274. Land-shell from Gault of Folkestone,240. Lebour, G. A., Limits of Yoredale Series, 539; Culm-Flora of Moravian Silesian Slates, 564. - Lias about Radstock, 381. Liassic Fossils, On some New, 203. Lincolnshire, Geology of North-west, 47. List of Papers in Section C, British As- sociation, 521. Lithomantis carbonarius, from the Coal Measures, 621. Lloyd, T. G. B., Geological Notes from New York, 520. Leonhard und Geinitz, Neues Jahrbuch, 92. 632 LON London and Neighbourhood, Geological Map of, 231. Lyell, Sir Charles, Obituary Notice of, 142. Lyell Medal and Fund, 192. Lyman, B. S., Geological Survey -of Yesso, Japan, 190. ACKINTOSH, D., Questions on Geological Action of Ice, 191; Boulders and Drifts of Eden Valley, 517; Correlation of Deposits in Cefn and Pontnewydd, 519; Origin of — Escarpments and Cwms, 569. Macrurous Crustacea, New, from Kim- meridge Clay, 620. Mallet, R., Mechanism of Stromboli, 286; Theory of Volcanic Energy, Remarks on, 335; Observations on Fisher’s remarks on, 510; Prismatic Structure of Basalt, 566. Man Isle of, Post-Pliocene Beds of, 80, 428, 226, 329. Mammalia found at Windy Knoll, 184. Manual of Natural History ; Instructions for Arctic Expedition, 1875, 614. Marschall, Count, On Transition from Carboniferous to Permian, 272. Marsh, Prof. O. C., on Tertiary Lake- Basins of North America, 232. Maxillary Bene of a new Dinosaur, 239. Mecocheirus Peytoni, H. Woodw., from the Kimmeridge Clay, 620. Mello, Rey. J. M., Bone-Cave in Creswell Crags, 512. Mendips, Inverted Strata of the, 566. Metallic Sulphides, Formation of, in Thermal Spring, 507. Meteorites, Chapter in the History of, 16, 70, 115, 141, 152, 214, 257, 311, 362, 401, 499, 548, 589. Miall, L. €., Structure of Skull of Ehizodus, 423. Microscopic Structure of Felspars, Pecu- harities in, 381. Mimose, On the Fossil, 230. Mineralogical Society, Formation of a, 569, Moore, C., Plicatocrinus and Cotylederma in British Strata, 626. Modern Vulcanicity, J. C. Ward on, 38. Modified Form of Dinosaurian Jlium,424. Morris, Prof. J., Boring. Mollusea in Oolitic Rocks, 267. Murchisonite, Beds of, in Estuary of Exe, 238. Murchison Medal, Presentation of, to Mr. Henwood, 187. Murphy, J. J., Formation of Polar Ice- Cap, 518. Index. PHY ATIVE Platinum of the Urals, As- sociation of, 561. Neocomian Sands _ with’ Nodules at Brickhill, 372. Newton, E. T., “‘ Tasmanite’”’ and Aus- tralian White Coal, 337. Nicholson, Prof. H. A., Oystiphyllum from Devonian Rocks, North America, 30; New Species of Paleozoic Polyzoa, 33; On some Massive Forms of Cheete- tes, 175; Appointment to St. Andrew’s, 192; Favistella stellata and Favistella calicina, 279; Guelph Limestones of North America, 343; Gasteropoda of Guelph Formation of Canada, 514. Nomenclature of Rocks, 425. Nordenskiéld, Prof. A. E., Former Climate of the Polar Regions, 525. Northern Norway, Sketch of Geology of, 385. (O eeriae ae Notices of Sir C. Lyell, 142; Sir W. E. Logan, 382; Prof. G. P. Deshayes, 430; W.J. Henwood, 431; F. E. Edwards,571; W.Sanders, 627. Oolitic Brachiopoda, 572. Origin of Escarpments and Cwms, 569. Ormerod, G. W., Murchisonite Beds of Kstuary of Exe, 233. Ornithosaurian from Purbeck Limestone, Langton, 382. Orthopterous Insect from Coal-measures of Britain, 621. Oscillations of Sea-level, Croll on, 141. Owen, Prof., Fossil Evidences of Sirenian Mammal, 46; On Prorastomus siren- cides, 422. Phosphatic AGE’S Economic Geology, Review of, 130. Paleozoic Botany from Dana’s Manual, Kchini, Notes on, 424. —— Polyzoa, New Species, 33. Past and Future of Geology, 375. Pelobatochelys Blakec and other Verte- brate Fossils, 136. Pennington, R., Bone-Caves near Castle- ton, 184. Pettersen, C., Sketch of Geology of Northern Norway, 386. Phillips’s Geology of Yorkshire, 141. ——— J. A., Rocks of Mining Dis- tricts of Cornwall, 235. Phosphatic Nodules from Bala Lime- stone, 238. Phosphates in Cambrian Rocks, 237. Phosphorite Deposits of North Wales, 183 | Physical Conditions of Deposit of Cam- brian Rocks, 511. Index. PLA Plant-bearing Series of India, Age and Correlation, 134. Plicatocrinus and Ootylederma in British Strata, 626. Polar Regions, Former Climate of the, 526. Polar Ice-cap, Formation of, 513. Post-Pliocene Formations of Isle of Man, 80, 226, 329, 428. Principes de Géologie Transformiste,619. Prismatic Construction of Basalt, 412; 566. Prestwich, Prof., Origin of Chesil-Bank, 228; On Past and Future of Geology, 375. Prussia, Deep-boring in, 48. Prorastomus sirenoides, 422. AIN-FALL in 1872, 192. Reade, T. M., Wind Denudation— Eolites, 587. Red Chalk, Hunstanton, 331. Red Rocks of Tyrone and Derry, 287. Relies of Cave Dwellers of Aquitania, (‘‘ Reliquie Aquitanice”’) 610. Review of Dana’s Notes on Paleozoic Botany, 177. Geological Map of London,231. Revue de Géologie, Delesse and Lap- parent, 45. Rheetic bone-bed near Frome, 96. Ricketts, Dr. C., Cause of Glacial Period, 573. Rocks of Mining Districts of Cornwall, 230. Royal Society of Edinburgh, Award to Mr. C. W. Peach, 288. Rudiments of Geology, by S. Sharp, 377. Rutley, F., Peculiarities in Microscopic Structure of Felspars, 381. er aa W., Obituary Notice of, 627. Sarsden Stones, Notes on some, 588. Scrope, G. Poulett, Volcanic Eruptions in Iceland, 289; Mallet’s Prismatic Con- struction of Basalt, 412; Cup-shaped Joints of Basaltic Columns, 625. Sea Life in the Deep, 88. Seeley, Prof. H. G., On Femur of Cryptosaurus humerus, 92; Pelobato- chelys -Blakei and other Vertebrate Fossils, 186; On Maxillary Bone of new Dinosaur, 239; Axis of Dinosaur from Wealden of Brook, 382; Or- nithosaurian from Purbeck Limestone, 382; Vertebrate Fossil from Gault, Folkestone, 521. Sharp, S., on Rudiments of Geology, 377. Sirenian Mammal, Fossil Evidences of, 46. 633 vol Skull of Rhizodus, Structure of, 423. Sorby, H. C., Fossil Forest in Coal- measures at Wadsley, 278. Specific Gravity of Precious Stones, 320. Sphenonchus hamatus, R. Tate on, 286. Stagonolepis Robertsoni and Evolution of Crocodilia, 275. Stromboli, Mechanism of, 286. Submerged Forests, 239, 283. Sub-glacial Formation of Gravels, 172. Sulphurets: What they are, 618. Superficial Geology of Central Region of North America, 516. (ee Coral, Description of new Genus of, 514. “ Tasmanite”? and Australian White Coal, 337. Tate, R., On some new Liassic Fossils, 203; Sphenonchus hamatus, 286; On Lias about Radstock, 381. Tawney, E. B., Cretaceous Aporrhaide, 139. Tennant, Prof., Notes on Diamonds from Cape of Good Hope, 545. Tertiary Lake-basins of North America, 232. Thomson, New Corals from Carbonifer- ous Limestone, 273. Torquay, Artesian Well at, 96. Traill, W. A., Travertine or Calcareous Tuff near Ballycastle, 608. Transition from Carboniferous to Per- mian, 272. Travertine or Calcareous Tuff near Bally- castle, 608. Triassic Rocks, Somerset and Devon, 163. Tylor, A., Action of Denuding Agencies, 438. Tupper, J. L., On Cruziana semiplicata, 274. NIFORMITY and Yulcanicity, 97. Ussher, W. A., Subdivisions of Triassic Rocks, 163. ALLEYS and their Relation to Fis- sures, Fractures and Faults, 131. Verbeek, R. D. M., Geology of Central Sumatra, 477. Vertebrate Fossil from Gault of Folke- stone, 521. Victoria, Geological Survey of, 562. Voice from the Past, 285. Volcanic Dust of Barbadoes, 287. Eruptions in Iceland, 289. ——— in Java, 141. Rocks of Lake-Country, 95. Volcanos, Contributions to the Study of, 1, 56, 99, 145, 206, 245, 298, 348. 634 WAR Wits: J. C., Modern Vulcanicity, 38; A Voice from the Past, 285; Granitoid and Associated Metamorphic Rocks, 518. ——, and Dakyns, J. R., Volcanic Rocks of the Lake Country, 95. Watford Natural History Society, 281. Weald, Denudation of the, 282, 336. West Indian Tertiary Fossils, 41. Fossils, Notes on, 544. Wilson, J. M., Probable Existence of Fault in Lias near Rugby, 273; Labyrinthodont from Coal-measures, 274. Whitaker, W., Guide to Geology of London, 619. Wind Denudation—FKolites, 587. Wollaston Gold Medal, Presentation of, to Prof. de Koninck, 186. Index. YOR Woodward, Henry, New Macrurous Crustacea from Kimmeridge Clay, 620; New Fossil Crab from Tertiary of New Zealand, 621; New Or- thopterous Insect from Coal-measures, 621; Discovery of Fossil Scorpion in English Coal-measures, 622. Woolwich and Reading Beds, newly ex- posed section, 234. Wright, Dr. T., Discovery of Cotylederma in Middle Lias, Dorsetshire, 505. “Wulfenite” at “Caldbeck Fell” 565. Vie Geological Survey of, 190. Yoredale Senasi in North of England, Limits of, 539. STEPHEN AUSTIN AND SONS, PRINTERS, HERTFORD. SERIAL Date Due oie AAARARAR AIO NAAN A: AANAAL at AAAAAL Baan RA return this item directly Ww to avoid fines. proper care and timely le at the Circulation Desk. ped belo wn a of wv my + = = 2 ABOT Cr SEP 10 20; | aA a S = : Z| | fo} s) = al = iS) Z, = iS) DN — & < O return of Library materials. Please to Cabot by the date stam Borrowers are responsible for the policy statement is availab AAA A AAAARA TAY VAIA ain . AAA Y Poll I Ww od OOO veew Jun. Uy MO Ai. nav , Rey tt YUM © WAY VOY "e \ “ite or ey AF a : Mee Fi = ss Ret yb Rey we )\4 4: NAA WAY \ vA of \ J U ANZ! | (asd yuuvuesces MN Nuuutge oe aes 7 yy WwW iat ae hey iain ge ; \ Th \ aren { VJ G yet. 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