~ ae oe en ea ee a een oe +o ’ fy ; yu 5 ; ne ig) sate ae oy oe > yD meee f Pin eat he wy wot ee ies Mes aeorepen tes Rak vhedoe y seit, awl Sere ae Cae Be We ee (228 WSS Oe Me ee 1) BS) de hom 1 SOE PT OSL) RY 2 BA? TS ee ee | i ey . B Ny a A . . | 4 y ee oi og ae é ak he wi “yiiaes€ =: THE QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY OF LONDON. EDITED BY THE ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY. - : Quod si cui mortalium cordi et cure sit non tantum inventis hzrere, atque iis uti, sed ad ulteriora penetrare; atque non disputando adversarium, sed opere naturam vincere - denique non ee probabiliter opinari, sed certo et ostensive scire; tales, tanquam veri scientiarum filii, nobis (si videbitur) se adjungant. —Novum Organum, Prefaiio. VOLUME THE FORTY-THIRD. 1887. LONDON: LONGMANS, GREEN, AND CO. PARIS: FRIED. KLINCKSIECK, 11 RUE DE LILLE; F. SAVY, 24 RUE HAUTEFEJUILE. LEIPZIG: T. 0. WEIGEL. SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. MDCCCLXXXVI1. List OF THE OFFICERS OF THE GEOLOGICAL SOCIETY OF LONDON. AAAALBE ALIN Elected February 18, 1887. DrestVent, Frof. J. W. Judd, F.R.S. Wice-Prestdents. H. Bauerman, Esq. A. Geikie, LL.D., F.R.S. Prof. T. G. Bonney, D.Sc., F.R.S. Henry Woodward, LL.D., F.R.S. Secretartes. W. T. Blanford, LL.D., F.R.S. | W. H. Hudleston, Esq., M.A., F.R.S. Foreign Secretarp. Sir Warington W. Smyth, M.A., F.R.S. Creasurer, Prof. T. Wiltshire, M.A., F.L.S. COUNGIL., H. Bauerman, Esq. Prof. J. W. Judd, F.R.S. Wa: Blanford, LL.D., F.R.S. R. Lydekker, Esq., B.A. Prof. T. G. Bonney, D. Se, LL.D., F.R.S. J. E. Marr, Esq., M.A. Thomas Davies, Esq. EK. Tulley Newton, Esq. Prof. P. M. Draven, M.B., F.R.S. Prof. H. G. Seeley, F.R.S. A. Geikie, LL.D., F.R.S. Sir Warington W. Smyth, M.A., F.R.S. Henry Hicks, MD., FE.R.S. J.J. H. Teall, Esq., M.A. Rev. Edwin Hill, M.A. Rev. G. F. Whidborne, M.A. W. H. Hudleston, Esq. M.A., F.R.S. Prof. T. Wiltshire, M.A., F.L.S. Prof. T. McKenny Hughes, M.A. Rev. H. H. Winwood, M.A. J. W. Hulke, Esq. poke R. S. Henry Woodward, LL.D., F.R.S. Prof. T. Rupert Jones, F.R.S. Assistant-Secretary, Clerk, Librarian, anv Curator. W. S. Dallas, Esq., F.L.S. Assistants in Office, Library, and Museum. Mr. W. Rupert Jones. Mrz. Francis E. Brown. An OT sd 8 TABLE OF CONTENTS. Page Bonney, Prof. T. G. Notes on the Structures and Relations of some of the Older Rocks of Brittany. (Plate XVII) ........ 301 Brovtiz, Rev. P. B. Notes on the Upper Keuper Section at Shrewley where Fish were found, and on the Trias generally in MUON See Potato oi cd thetats 5 «See de's) < asceie's\alaste » atcy eikde « 540 Catitaway, C., Esq. On the Alleged Conversion of Crystalline Schists into Igneous Rocks in County Galway .............. 517 . A Preliminary Inquiry into the Genesis of the Crystalline Sree iio Malvern ls. t,o 5. wise wite ws o'er ot eoebe yeas 526 Davin, T. W. Epewortn, Esq. Evidence of Glacial Action in the Carboniferous and Hawkesbury Series, New South Wales .... 190 Davis, James W., Esq. On Chondrosteus acipenseroides, Agassiz. OL LSU) Oe ee ee ea 605 Derpy, OrviLtE A., Esq. On Nepheline-Rocks in Brazil, with Special Reference to the Association of Phonolite and Foyaite . 457 Donatp, Miss JANE. Notes upon some Carboniferous Species of Murchisonia in our Public Museums. (Plate XXIV.) ...... 617 Duncan, Prof. P. Martin. On a new Genus of Madreporaria (Gly- phastrea), with Remarks on the Morphology of Glyphastrea Forbesi, Ed. & H., from the Tertiaries of Maryland, U.S. GEIS SLL)" oo 8 Oe ee 24 On the Echinoidea of the Cretaceous Strata of the Meme Mas toca TOT Ny Ao has 2 Sik yas vation, vis's) + nis'a" Saale eRe sisie s 150 IV TABLE OF CONTENTS. Page Duncan, Prof. P. Martin. A Revision of the Echinoidea from the Australian Mertiaries 2, M.'s. 5.6 sees ie ce eee 411 Espen, J. Vincent, Esq. On the Superficial Geology of the Southern Portion of the Wealden Area... 2.55.2. ose sae 637 GarpNer, J. StarKin, Esy. On the Leaf-beds and Gravels of Ardtun, Carsaig, &c., in Mull. (Plates XIII-XVI.) ........ 270 Grestey, W.S., Esq. Notes on the Formation of Coal-seams, as suggested by evidence collected chiefly in the Leicestershire gud) Seuth, Derbyshire Coal-teldcp nc. 4 sca etn reer ro 671 Groom, T. T., Esq. On some new Features in Pelanechinus coral- dinuss. (Plate: XX VTL.) ele ose senate nic tetera eee eee 703 Hitt, Rev. E. The Rocks of Sark, Herm, and Jethou .......... 322 Hit, W., Esq., and A. J. Juxes-Browneg, Esq. On the Lower Part of the Upper Cretaceous Series in West Suffolk and Norfolk .. 544 Hupirsron, W. H., Esq. Supplementary Note on the Walton- (Comment Section Hj.) s. 1. aloe elects eke alates hl eee eye) ataeee 445 Hueuss, Prof. T. M¢Krnny. On the Drifts of the Vale of Clwyd and their Relation to the Caves and Cave-deposits. (Plate IX.) 73 On the Ancient Beach and Boulders near Braunton and Croyde in Northy Devom iy, sie soy oasis lene ee ee 657 Hurtxr, J. W., Esq. Note on some Dinosaurian Remains in the Collection of A. Leeds, Esq., of Eyebury, Northamptonshire .. 695 Hutton, Capt. F. W. The Eruption of Mount Tarawera........ 178 Huxtry, Prof. T. H. Further Observations upon Hyperodapedon Gordont. (Plates XOX VE, XOOVAM yy 9. eee ere tee item etet a 675 Irvine, Rev. A. The Physical History of the Bagshot Beds of the Taondon, Basin «sic. ras + «ach phe oe ciphetel elicitin eee 374 Jones, Prof. T. RuprertT. Note on Nummutlites elegans, Sowerby, and other English Nummulites. (Plate XI.)................ 182 Jukes-Browng, A. J., Esq., and W. Hixt, Esq. On the Lower Part of the Upper Cretaceous Series in West Suffolk and Norfolk .. 544 Kor, Prof. Bunps1ro. On some Occurrences of Piedmontite-Schist TM SAPAM, are. os sages a asec iete a oo ayeancienelinie Doman ls chee ieee 474 LYDEKKER, R., Esq. The Cetacea of the Suffolk Crag. (Plate II.) TABLE OF CONTENTS. Vv Page LyYDEKEKER, R., Esq. Description of a Jaw of Hyotherium from SBMS ECM E! Ob PMU: arte iend a aia «cared SOT Ih ale ates Wieie sperma aM 19 . On certain Dinosaurian Vertebre from the Cretaceous of Eads and ther isle OFAWIENE 2. ccsicicds vale aula ee we te oie ore 156 On a Molar of a Pliocene Type of Equus from Nubia .... 161 Lyons, H. G., Esq. On the London Clay and Bagshot Beds of PE PE Nach Sapte Fisica at aerletn i eem eee ee es 5 a 451 Martin, Josian, Hsq. The Terraces of Rotomahana ............ 165 Newton, E. T., Esq. On the Remains of Fishes from the Keuper of Warwick and Nottingham; with Notes on the Mode of Occurrence by the Rey. P. B. Broprs, M.A., F.G.S., and Epw. iiercone rsd. F.G.S.. (Plate X XE) othe cece ie dawns 537 Owen, Sir Ricuarp. On the Skull and Dentition of a Triassic Saurian (Galesaurus planiceps, Ow.). (Plate I.) ............ PrestwicH, Prof. JosepH. Considerations on the Date, Duration, and Conditions of the Glacial Period, with reference to the we EEG) ec oe 393 RADCLIFFE, JAMES, Esq. On Grooves and Quartzite Boulders in “oe Lape lete Gey aL i acs) Cs Re 599 Raitsty, Miss CATHERINE A. Notes on the Metamorphic Rocks of Sar TIED a fete fect ais o's che Ais} cuschale eee 337 WHiTAKER, WILLIAM, Esq. Further Notes on the Results of some Deep, Borings in. Kents i s).ceriee an» «dei raipier ete eee ee te 197 Witson, Epw., Esq. Notes on the Triassic Beds at Colwick Wood, near Notting hams/2750.2/.,cajie +5 eels selisiee ste ca eet aici (omelet 542 Woopwarp, A. Smiru, Esq. On the Dentition and Affinities of the Selachian Genus Ptychodus, Agassiz. (Plate X.) ........ 121 PROCEEDINGS. Anniral Reports... sos. e 8s laaerele ee atatere leuegels ote eee ool ene 8 luist-of Foreign Members. +... .5 Jae casio keene 17 List. of Foreign Correspondents i. (ey. real aii ieee ee eee 18 Ikist of Wollaston, Medallists...) ae ee ae ee eee 19 ist of Murchison Medallists: \. 1... seer etn een eee tte eae dist of Iuyell Medallists i015 0.) se eee eee eee oe 22 list of Bigsby, Medallists: {Ansa o sae ere ehersiches e entho= ie Ie Applications of the Barlow-Jameson Fund ...........++- Snonogen mead Pimaneralvive port si ..g041.: eee ee eee Gee OO dGo cog omuam, 2c TABLE OF CONTENTS. ETUDES a ee een en Anniversary Address 2 0s) So Se Se. ee ee 6 eee) 6s Be eee 6 2 ae © 8s « ee 8 Bes Donations to the Library (with Bibliography) ............... one BaRKLy, Sir Artucr. Letter on the Slip of a Peat-Bog in the Falkland Islands Ce een Pee ee Oe oe ee eee Se BS © las Be be ’e 60 e se oe a ea 8 6 Uxricu, Prof. Notice of his discovery of a peculiar alloy of Iron and Nickel in New-Zealand Rocks .........0.00.e0eecenves STANLEY, W.F., Esq. On the probable amount of former Glacia- tion of Norway, as demonstrated by the present condition of Rocks upon and near the Western Coast ..............000 “ Société Ouralienne d’Amateurs des Sciences Naturelles,” notice by the President of an exhibition to be held by the, at Ekaterine- bourg iat ne a Ce we ge o Penne Be ab SS Bae Be eee eae Oe CK Ree eseqgacee 92 83 LIST OF THE FOSSILS FIGURED AND DESCRIBED IN THIS VOLUME. [In this list, those fossils the names of which are printed in Roman type have been previously described. ] Name of Species. Formation. PLANTA. oe Si SO ae a \ Lib) 4b Sat a See 4 Behmeria antiqua. Pl. xv. f.1 Corylites Macquarrii. Pl. xv. f. 3. Glyptostrobus europzus. PI, xiii. Joa: o> i ee ! Myrtacee, aapeosed leaves of. PI. | XVi. i: Zs a, 0 : = ee ie ecces 6 Leaf-beds eee es UE ue eee eee Podocarpus borealis. Pl. xiii. f.3. | Quercites groenlandicus. Pl. xiv. Laas ae ere Sequoia Langsdorfii. PI. xiii. f. 1. Undetermined leaves. Pl. xiv. f.3; 2 eS Bee oe PROTOZOA. (Foraminifera. ) ER IOMS aa cc cocobendiece sence Nummulites elegans. PI. xi. f. 1-9. —— variolarius. Pl. xi. f. 10-14. Locality. eo Oo — Page. 290 290 291 290 289 291 289 289 291 289 291 142 147 145 FOSSILS FIGURED AND DESCRIBED. Name of Species. C@LENTERATA. ( Actinozoa.) | Formation. Locality. een raun Blackwoodi. PI. iv. {3 COCe ores et osoeeseseeresetessesesesees iv. fa AB eet Shisha Kon dine Merusheas concinnum:. Pl ive i. Wo 222. » var. furcatum. ) Pl. iv. —— cylindricum. PI. iv. f.5...... PEACH CHE cyt)! Oe eseeecee latiseptatum: “Ply. f. Gio... —— ——, var. giganteum. Pl. v. POLS carpio id nisin saleston ashe epee —— ——, var. interruptum. Pl.v. BD es adoecch est aaa oanedes eee \ | f Carboniferous Tertiary ---(SCOUARE 2 coset <: feet eeees)| ECHINODERMATA. Catopygus elegans .........ssssceseeeee Cidaris (Leiocidaris), sp. ............ Clypeaster foliumy \-.-.20.ceseere- were PipPPSlaMdveUs| | &ie...0.5:-.s6s.2essees Ao Sse Due from Stanford on account of Geological Map LOG 65 11 11 £3106 5 10 We have compared this statement with the Books and Accounts presented to us, and find them to agree. (Signed) L. FLETCHER, : JOHN HOPKINSON. } Aus 4 February, 1887. FINANCIAL REPORT. 27 Year ending 31 December, 1886. EXPENDITURE. House Expenditure: fs a. 2B Set 2 ES Re eee one ere ee 29 5 0 Ripe MEISE ANCG 25 46 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. the prize-farm district around Oxford in 1870, of the geology of Belgium, and of Sweden and Norway. In his report upon Denmark he pointed out how each of the geological formations in that country is characterized by a distinctive system of agriculture.” Mr. Jenkins was elected a Fellow of this Society in 1863, and, in spite of ever multiplying and distracting occupations, he always Look the warmest interest in our affairs. To the trying disease against which he had struggled so manfully, he at last fell a victim, passing away last Christmas eve at the early age of 45. Few men have accomplished so much work in so short a time and under such adverse conditions. At his open grave the prince who presided over the great Society which he served so faithfully, and the farmers and peasants whose interests he had spent so large a share of his life in promoting, were alike represented; but among those who mourned ° his loss there were none who felt it more keenly than his early friends and fellow-workers of the Geological Society. Dr. Harvey Bucwanan Hott was born at Worcester on the 28th of September, 1820, and received his early education in that town and at Birmingham. When only 17 years of age he met Sir Henry De la Beche, whom he accompanied for six months while engaged in his important studies of the geology of Cornwall and Devon. De la Beche seems to have formed such a high opinion of the abilities of the young geologist that he recommended him to the notice of Professor Rogers, and the result was that young Holl found employ- ment for three years on the Geological Survey of Pennsylvania, afterwards travelling for a year in the United States on his own account. From the pupil of such masters as De la Beche and Rogers good services to geological science might be looked for; nor was the expectation disappointed. After returning to England and taking his medical degree, Dr. Holl accompanied the British Army to the Crimea, remaining there till the end of the campaign. For some time after his return he practised his profession in London ; but in 1862 he retired to Malvern, and in the same year became a Fellow of this Society. It was then that he found time for the carrying out of his valuable studies on the geology of the Malvern Hills. In opposition to Murchison’s views, he maintained the non- intrusive character and the Archean age of these rocks, constituting himself a pioneer in the study of those isolated portions of the pre- Cambrian floor of Britain which have been uncovered by denudation, and which, during recent years, have attracted so large a share of the attention of geologists. ANNIVERSARY ADDRESS OF THE PRESIDENT. 47 Other important papers on stratigraphical geology which he contri- buted to our Journal were those on the correlation of the several sub- divisions of the Inferior Oolite in the Middle and South of England, and on the older rocks of South Devon and Cornwall. He also published a number of papers on fossil sponges and Entomostraca, the latter with the cooperation of Professor T. Rupert Jones. When ill-health prevented him from continuing his work among he Field-Clubs of the west of England, of which he had so long been a most active member, he retired to his native town, still with microscope and pencil carrying on his labours among the minute fossils which he had studied with such loving care. Dr. Holl succumbed to the effects of heart-disease on September 11th, 1886, and in him we have to mourn the loss of one who has greatly contributed to the advance of geological knowledge in a number of widely different fields. In Mr. Caters Evans we have lost another of those hard-working amateurs to whose exertions the advance of geological science has been so largely due. He was born in July 1831, and educated at University College School. He lost his father while still young, and after being educated as a solicitor, received in the year 1852 an appointment in the Chancery Pay Office, which he retained till 1882, when compelled to retire through ill-health. Mr. Evans was a remarkable example of what can be accomplished by an ardent student of Nature, even when his lot in life happens to be cast in {he heart of this human wilderness of London. Having taken up the study of geology in 1855, he found among the excavations for the new sewers in this city, and in unfinished cuttings of railways leading from it, abundant opportunities for the collection and study of fossils, supplementing this work by researches carried on at the seaside during his vacations. In this way he accumulated a large and valuable collection, some important type specimens from which were bequeathed by him to this Society. He took a very active part in the work of that very useful body the Geologists’ Association, of which he was one of the earliest members, and to its Proceedings nearly all his papers were communicated. His most notable con- tribution to geological literature was the well-known paper “On some sections of Chalk between Croydon and Oxtead, with Obser- vations on the Classification of the Chalk,” in which there was made the first attempt in this country to base a classification of the beds of the Chalk upon palontological data. This memoir, which 48 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. essayed to do for England what Prof. Hébert did for France, has formed the basis of much excellent work since accomplished by M. Barrois, Mr. Jukes-Browne, and other geologists. With this important question of the classification of the Chalk strata Mr. Evans’s name will ever be honourably associated, giving him as it does an undisputed claim to a niche in our Geological Temple of Fame. Happy to the end in the study of Nature, to which he devoted his last years of physical weakness and decline, he passed away in his home at Hampstead on the 16th September, 1886. From a remote Devonshire rectory we have received two papers, short but full of promise, from the pen of the Rev. Wrrttam Downes. These papers showed that the Society had secured, by his election in 1872, the aid of an able student of the very interesting Cretaceous rocks of the West of England, and one who had exceptional oppor- tunities for their detailed investigation. We have, alas! to record his death on the 12th October, 1886, at the age of 48. Professor FrepErick GuTuRiz, F.R.S., the eminent physicist, who died on the 21st October, 1886, had been for some years a Fellow of this Society. Some of his researches upon physical questions, especially those bearing upon the continuity between the states of solution and fusion, have an important bearing on geological problems, and these their author clearly saw and forcibly pointed out. Born in London in 1833, Dr. Guthrie was educated at Uni- versity College School and University College, receiving a further chemical training in the Universities of Marburg and Heidelberg. Acting first as demonstrator to Dr. Frankland at Manchester, and then to Sir Lyon Playfair at Edinburgh, he became Professor of Physics at Mauritius ; afterwards, succeeding Dr. Tyndall, he obtained the appointment which he so worthily filled at the time of his death, that of Professor of Physics in the Normal School of Science and Royal School of Mines. His death at the early age of 52, which resulted from a morbid growth in the throat, has deprived science of an enthusiastic and ingenious student, and his colleagues of a much- loved friend and coadjutor. One of these, who knew him well, has aptly compared his whimsical admixture of simplicity and wisdom, of kindliness with pungent but never caustic humour, to the immortal character of Uncle Toby. | In Mr. Artur Grote we have lost one of those valuable members who, after long service in our Indian Empire, return with wide knowledge and ripe experience, ready to be placed at the service of ANNIVERSARY ADDRESS OF THE PRESIDENT. 49 the scientific societies of their native land. Mr. Grote, who was a younger brother of the historian, was born on the 29th November, 1814, at Beckenham in Kent ; from 1833 to 1868 he was a member of the Indian Civil Service, at the end of his career occupying one of the highest administrative posts in the Bengal Presidency. He joined this Society in 1846, and after his retirement from official life found satisfaction for his scientific tastes and sympathies in attending the meetings and assisting in the administration of the affairs of the Royal Asiatic, the Zoological, and the Linnean Societies, as well as of our own. A man of charming manner and most amiable character, his presence will be missed by a large circle of scientific friends. From our Foreign list we have been compelled to erase the honoured names of Abich, Guiscardi, and Cornet. Dr. Hermann AxicH was born in Berlin, 11th December, 1806. He first became known to the scientific world by his careful chemical analyses of the spinels and other minerals; but he afterwards devoted his attention to the study of volcanic phenomena, and in this connexion his investigations on the chemical composition of the gases of fumaroles and of the deposits which are found on the sides of voleanic vents are of especial value. He was a warm advocate of Von Buch’s theory of “ Erhebungscratere,” and though few geologists at the present time will be found ready to accept his arguments on this subject, every one must admire the careful observations on the structure of volcanoes which he brought together in several well-known works. In 1837 appeared his ‘ Vues Iilustratives de Phénoménes Géologiques observés sur le Vésuve et VEtna pendant les Années 1833 et 1834,’ and in 1841 his ‘ Geolo- gische Beobachtungen iiber die Natur und den Zusammenhang der vulkanischen Bildungen.’ Having been appointed Professor of Mineralogy at Dorpat, Abich’s attention was directed to the study of the geology and mineralogy of different parts of the vast Russian Empire. He subsequently removed to Tiflis, and from that time his studies were chiefly devoted to the elucidation of the geological structure of the Caucasus and surrounding districts. So long ago as 1857 he was elected a Foreign Member of this Society. The last few years of his life were spent at Vienna, where he was engaged in embodying the results of his numerous researches in a great monograph entitled ‘ Geologische Forschungen in den kaukasischen Landern,’ of which one part only has as yet appeared. He passed away on July Ist, 1886, in his 80th year. VoL. XLII. é 50 PROCEEDINGS OF THE GHOLOGICAL SOCIETY. GueLIELMo GuIscaRpI, who was born in Naples in March 1821, was educated for the profession of an architect. When he was 24 years of age, however, the meeting of a Scientific Congress at Naples, which he attended in order to learn something about building-materials, seems to have directed his attention to the interest attaching to geological studies. Entering the class of the veteran mineralogist Professor Scacchi in the University of Naples, Guiscardi soon became the most distinguished of his pupils. The revolution of 1848 found the young geologist in the ranks of the army which endeavoured to overthrow the Bourbon dynasty in Naples ; but on the failure of that attempt, he retired to a private life of intense study for the next twelve years. The victory of the national cause, to which he was so greatly attached, came at last, however, and he was then in 1860 appointed Professor of Geology in the University of Naples, a post which he retained till the time of his death. Professor Guiscardi was a man of very wide culture and extensive knowledge, as was shown by his paleontological papers on the genera Nerita and Atwria, on the family of the Rudistes, and those on the fossils found in blocks ejected from Vesuvius, by his petrographical papers on the rocks of Vesuvius and the Phlegrean fields, and by his chemical researches on the gases: escaping from volcanic vents. He was elected a Foreign Corre- spondent of this Society in 1879. Many of our members can bear testimony to the cordiality with which foreign students of his science were always welcomed at Naples by our esteemed Correspondent, who ever showed himself ready to assist them in their researches ; I can myself never forget the kindness which I received from one with whom I contracted a warm friendship. For some years past an affection of the eyes had caused him much suffering and anxiety, and he died at. Naples on the 11th December, 1885, at the age of 64. Francois Leopotp Cornet was born at Givry in Belgium on the 21st February, 1834. At the age of 16 he entered as a student the “‘ Ecole des Mines ” of Hainault, and, obtaining his diploma in 1853, became a mining engineer. For some years he was engaged in the direction of the operations of several coal-mines, and in this capacity he introduced two notable improvements into the working of the Belgian collieries, namely the employment of compressed air as a motive power, and the use of the endless chain for transport purposes. Forming the acquaintance of another mining engineer, M. A. Briart, now an esteemed Foreign Correspondent of this Society, Ee Pa ANNIVERSARY ADDRESS OF THE PRESIDENT. 51 M. Cornet entered with him into a scientific partnership, and from this time forth all the valuable geological researches which they carried on were published under their joint names. In 1865 they announced the discovery of an older series of Eocene strata than had hitherto been recognized, and in subsequent papers the strati- graphy and paleontology of these most ancient members of the Tertiary series and of the underlying Cretaceous rocks were carefully elaborated. These papers were, however, interspersed with others bearing upon anthropological questions and on the Carboniferous strata of Belgium. During the later years of his life M. Cornet was engaged in developing the remarkable industry which had arisen in Mons through the working of the phosphate beds of the Chalk. In 1883 he was elected one of our Foreign Correspondents, and only last year he contributed to our Journal a very valuable paper describing the Cretaceous strata of Mons which contain the remark- able deposits of phosphate of lime. Little did we think at the time that this was the last communication which would come from his hands, but in January last we received the sad news of his death at the age of 53. The Report of the Council indicates a very flourishing condition of our affairs—both in respect to the number of our Fellows and the state of our finances; but I need scarcely remind you that, gratifying as these circumstances are, the true index of the well- being of our Society is to be found in the amount and importance of the original work done by its members, as shown by the contents of our annual volume. During the past year the number of papers submitted to the Society has been at least as large as in any previous year, and I am persuaded that when tried by the test of time there will be found to be no falling off in their scientific value. In a year when so much attention has been directed to our Colonial and Indian possessions, and when we have had the pleasure of greeting in this room some of our most active members, who are citizens of the Greater Britain beyond the seas, it is not surprising that communications bearing on the geology of these British ‘“ outliers” have been as numerous and valuable as they were welcome. The Societies which occupy common ground with ourselves—our valued auxiliaries the Palzontographical Society, the Mineralogical Society, and the Geologists’ Association—have well kept pace in the ever-forward movements of the past year; the numerous provincial Geological Societies and Field-clubs have all aided in e2 52 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. swelling the strength of the advance; while the ‘ Geological Magazine,’ appearing at shorter intervals than our own Journal, has satisfied all the requirements of the light skirmishers of our army. The two great state-supported institutions to which Geologists always look for aid in their work have not been wanting in effort since our last Anniversary. The Geological Survey has already completed the one-inch map of England, that of Ireland will be finished during the next year, while their last great remaining task—the important one of mapping the Scottish Highlands—is being vigorously attacked both from the north and the south. Valuable work of revision in the country already surveyed is also being pressed forward, the most notable achievement in this way during the past year being the complete confirmation by Mr. Clement Reid of Professor Prestwich’s important discovery, which was made in 1857, of the existence of Pliocene outers on the North Downs. Nor has the Natural History department of the British Museum been behind its sister institution in the work it has accomplished. The rearrangement of the paleontological and mineral collections, under more favourable conditions of space and light, has gone on steadily ; valuable monographs like those of Dr. Hinde on the fossil sponges, and of Mr. R. Etheridge, jun.,and Mr. P. H. Carpenter on the Blastoidea have been issued; and catalogues like those of Professor Rupert Jones on the Foraminifera, of Mr. Lydekker on the Fossil Mammalia, and of Mr. Kidston on the Paleozoic plants have been published. Among the good work done by some of our members who direct the affairs of the Museum, we must not overlook the admirable and successful efforts which are being made to increase the value of the collections for educational purposes. ‘The specially arranged collections for the guidance of students and beginners, and the cheap and accurate guide-books now issued, afford sufficient evidence that the Director and Keepers of the Museum are alive to a very urgent national want. From among those whose interest has been excited and whose earliest cravings for information have been supplied by such means as these, our own and other societies must look for future recruits. It may not therefore be uninteresting to mention that of the cheap illustrated guide to the Paleontological Galleries, prepared by Dr. Woodward in 1880, four editions have already appeared and over 12000 copies have been sold; while of Mr. Fletcher’s Guide to the Mineralogical Gallery, with its charming introduction to the study of Mineralogy, no less than 4000 copies have been disposed of within a very short period. ; ANNIVERSARY ADDRESS OF THE PRESIDENT, 53 At the last meeting of the British Association, held at Birmingham, geological questions occupied a full share of the attention of its members. In addition to the comprehensive address of the Presi- dent, Sir William Dawson, which dealt with very complex geological problems, and the lucid discourse of my predecessor in this Chair, who supplemented the reviews which he has given in this room of the results of the application of microscopic methods to the study of igneous and metamorphic rocks respectively by an equally striking and suggestive treatment of the aqueous rocks from the same point of view, Geologists have to thank the distinguished mathematician, Professor G. H. Darwin, for the comfort afforded to them in his very modest and thoughtful address. Should certain more recent utterances from the mathematical fold have produced a moment’s disquiet in any faint-hearted Fellow of this Society, I can confidently recommend to him the perusal of Professor Darwin’s cautious and reassuring essay. The commencement of several important undertakings have marked the present year in the annals of geological science. Those who desire to perpetuate the memory of the late John Morris could not possibly have chosen a better method for doing so than that of promoting the publication of a new edition of his in- valuable ‘Catalogue of British Fossils.’ In the third of a century which has elapsed since the second edition appeared, the progress of paleontological research has been so rapid that no single individual —even if gifted with the encyclopzedic mind of Morris himself—could possibly expect to cope with it. A number of able workers have, however, rendered themselves responsible for the cataloguing of the several groups which they have especially studied, while Dr. Henry Woodward has undertaken to act as Editor. Professor Morris’s nearest surviving relative having engaged to supply the necessary funds, and the Syndics of the Cambridge University Press having arranged to print it, we may hope at no distant date.to see this important work issued. ° Mr. Teall, in his ‘ British Petrography,’ has entered upon a task, the accomplishment of which was much needed, and which is well worthy of the sympathy and support of all geologists. He proposes to prepare descriptions, to be illustrated by carefully executed coloured plates, of the chief types of our British rocks. How com- petent Mr. Teall is for the execution of such an undertaking, he has given ample proof in several papers laid before this Society. In these days of rapidly increasing petrographical literature, every one must 54 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. feel indebted to the author for the careful manner in which he follows up the comparison of our British types with those described by foreign petrographers. Mr. Mellard Reade, who is so well known to geologists by his thoughtiul and suggestive addresses to the Geological Society of Liverpool, has found an admirable subject, which he has treated with great skill and no little originality, in his ‘ Origin of Mountain Ranges.’ To the manner in which the advancement of geological science is being promoted by the various societies in other countries, and the surveys undertaken by foreign States, I can do no more than barely allude. Everywhere we have to note the same steady and sustained efforts, before which the clouds that have enveloped the story of former times are being gradually rolled back, and the light of knowledge is illuminating the obscurest problems connected with the past history of our globe. In the advance of an army through an unknown and difficult country there must always be some risk of the communications between its several divisions breaking down, and of their power for effective cooperation becoming impaired; more especially does this danger arise when the army is large in its numbers, complicated in its organization, or swift and sudden in its movements. Now that vast host of geological investigators which is ever pressing forward to conquer new realms of knowledge is distin- guished among all the armies of science by the rapidity of its evolu- tions; the history of Geology is the chronicle of a brilliant succession of forced marches. It may therefore be prudent if, from time to time, we pause to look around us and to inquire if there be any chance of the centre of our army, while engaged in steadily grappling with the vast physical problems which confront it, losing touch with either of its wings—that which is composed of the cultivators of the mineralogical sciences on the one hand, or that which is formed by the students of the biological sciences on the other. From that position of elevation and of observation in which I find myself placed by your indulgent suffrages, it has occurred to me that I may possibly render a service by reporting to you the main features of the field of conflict, so far as it is given to me to discern them. ANNIVERSARY ADDRESS OF THE PRESIDENT. 55 In attempting such a survey, I of course do not forget that a just idea of so vast a field can scarcely be obtained from any single standpoint ; but I am satisfied that no better vantage-ground could possibly be found for the purpose than that afforded by this Chair. Without for one moment forgetting the workers belonging to other countries or connected with kindred associations, I may claim for this Society that it has ever taken a foremost place in promoting the progress of geological science ; that the initiative in many of its most remarkable advances has been due to our Fellows; and that all the leading episodes of its short but brilliant history will be found faithfully reflected in our publications. It is my purpose to-day to invite your attention to the past and present relations between Geology and the Mineralogical Sciences. The geologists of this Society stand in no need of the reminder that ‘“‘ their father was a mineralogist.” That little band of enthu- siasts who, just eighty years ago, constituted themselves the nucleus of the Geological Society of London were before all things mineralogists; and the initial object of the formation of the Society was a purely mineralogical one, that of securing the publication of Count Bournon’s laborious treatise on the varied forms assumed by the crystals of calespar. Little could its original members have anticipated many of the directions in which the work of the Society was destined to develop itself. An examination of the first series of our ‘ Transactions,’ published between the years 1811 and 1821, will show that all the really valuable and enduring work of the Society, during this first epoch of its history, was either mineralogical or petrographical. Looking back on that work, we may indeed feel proud of the achievements of these founders of our Society. We find Wollaston engaged in devising his beautiful contrivance for measuring the angles of crystals, and William Phillips illustrating the value of the reflecting goni- ometer by accumulating a great mass of accurate determinations ; we see Whewell, and afterwards Miller, labouring to place on a secure basis the mathematical methods best adapted for the discus- sion of these measurements; while Brewster and Herschel are steadily feeling their way towards the pregnant generalization that the geometrical forms of crystals are but the outward and visible’ signs of an inward molecular structure, which becomes clearly mani- fested by its action upon polarized light; at the same time Macculloch, bringing to bear on his studies in the field a vast amount of accurate chemical and mineralogical knowledge, is found ~ 56 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. engaged in laying the foundation in this country of the study of rocks. If now we turn to the second series of our ‘ Transactions’ and the earlier volumes of our ‘Journal,’ published between the years 1824 and 1858, we shall perceive a startling falling-off in the con- tributions to mineralogical science, too sure a sign of that neglect and almost contempt with which Mineralogy had come to be regarded by the geologists of that period. This unfortunate result was doubtless to some extent due to the powerful counter-attraction exercised by Stratigraphical Geology, which had received such a remarkable impetus from the labours of William Smith, and of Paleontology, which was daily being enriched by the discoveries of Cuvier, Conybeare, Buckland, Mantell, and Owen. But it must, at the same time, be confessed that many mineralogists had at that period permitted themselves to be betrayed into a position of more or less pronounced antagonism to all the later developments of Geology, and their science in turn had come to be regarded by geologists with feelings of suspicion and distrust. Perhaps I cannot better illustrate the relations which had grown up between the geologists and mineralogists of that day than by referring to an incident which was related to me by Charles Darwin, shortly before his death, as haying exercised an important influence on his own career as a geologist. While Darwin was a student at Edinburgh, it was the custom of Jameson, who was justly regarded at that time as the apostle of exact mineralogical knowledge in this country, to take his class to Salisbury Crags and there to inveigh in no measured terms against the infatuation of geologists in main- taining the igneous origin of those masses of basalt. Under such circumstances as these it is not surprising to find that geologists, judging the tree by its fruits, were led to conclude that from Mineralogy there was little to be hoped for in the way of assistance to their own science, and nothing at all to be feared in the way of criticism. Although this state of estrangement between Geology and Mine- ralogy has now happily passed away, since the causes which brought it about have disappeared, it may still be doubted whether all the cultivators of these two sciences fully realize their mutual depend- ence, or clearly recognize their capabilities for mutual assistance. It may not be unprofitable, therefore, to inquire how perfect cooperation between mineralogists and geologists may best be promoted, and to reconnoitre those promising fields of research through which their joint advance must be made. ANNIVERSARY ADDRESS OF THE PRESIDENT. 57 The realm of Nature has been recognized from time immemorial as consisting of three kingdoms: dealing with the affairs of these three kingdoms, respectively, there have grown up side by side three departments of natural knowledge—Zoology, Botany, and Mine- talogy. But in recent years new and, I cannot help thinking, regrettable relations have sprung up between these sister sciences. Zoology and Botany, having developed a method, a classification, and a nomenclature, based on common principles, have been drawn together by bonds so close and firm that many regard them as in- dissolubly one—the science of Biology. Mineralogy, thus isolated, has been driven to seek new and unnatural alliances,—with Chemistry, with Physics, or with the Mathematical Sciences. For my own part I confess that I regard this threatened “‘ Repeal of the Union ” of the natural sciences as alike a misfortune and a mistake. Tt is sometimes assumed that the objects dealt with by Zoology and Botany are so different in their essential characters from those treated of by Mineralogy, that the science of “‘ Organic” nature must always follow a different path from that pursued by the science of ‘, pl. xlii. figs. 1, 2. A left periotic, from the Red Crag, in the British Museum (No. 39020), from the narrow and elongated form of the portion containing the semicircular canals, evidently belongs to the present genus (as distinct from Balenoptera and Cetotherium) ; and as it 1s apparently adult, and much smaller than the corresponding bone of MW. affinis figured by Van Beneden in the Ann. Mus. R. Hist. Nat. Belg. vol. vii. pt. 3, pl. xl. fig. 4, and is apparently too large for MW. (Burtinopsis) minuta, Van Beneden, the probability is that it belongs to the somewhat larger M. (Burtinopsis) similis, Van Beneden. The small W. minuta is represented by a nearly perfect left tympanic (Pl. II. figs. 5, 5a) from the Coralline Crag, which is preserved in the Ipswich Museum, and agrees exactly with the tympanic figured by Van Beneden, op. cit. pl. xevil. figs. 9-11, under the name of Burtinopsis. Uixcept by its smaller size, the English specimen can scarcely be distinguished from the tympanic of the existing MW. boops. To the genus Balenoptera belongs the so-called Balena definita, Owen, of which there is a fairly perfect tympanic in the Ipswich Museum (PI. II. figs. 3,3.a). This specimen agrees exactly with the imperfect type tympanic (of which a cast is preserved in the Museum of the College of Surgeons +); and as it differs from the corresponding bone of B. Goropi, Van Beneden, by its larger size, its * In many instances it does not appear to me by any means certain that the _ vertebrze belong to the same speciesas the tympanics, and it is therefore advisable to regard the latter as the types of such species. Tt Ann. Mus. R. Hist. Nat. Belg. vol. vii. pt. 3, pls. Ixxxix. & xevii. The recent tympanic figured in pl. Ixxxix. figs. 15, 16, under the name of Balenoptera antarctica, certainly belongs to Megaptera boops, and might have been drawn _ from a specimen in the British Museum (No. 2.76.16.18). t Nos. 2805 and 2832 in the same collection belong to this species. 12 MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. greater inflection, greater height of the inner wall, smaller depth of the Eustachian notch, sharper posterior angle, and more gibbous in- volucrum, there is little doubt of its specific distinctness, and every probability of its being identical with the so-called B. Sibbaldina, Van Beneden, of which the tympanic has been hitherto unknown. This is confirmed by a very fine late cervical vertebra from the Red Crag in the Ipswich Museum, which corresponds exactly with the type specimens of the latter form in the Brussels Museum. The rather smaller B. Goropi, Van Beneden*, is represented by an imperfect tympanic from the Red Crag, in the British Museum (No. 39016), and probably by some vertebree in the same collection. Of the still smaller B. borealina, Van Beneden, there is an imperfect tympanic (of which the British Museum has a cast) in the Ipswich Museum, from the Red Crag, as well as two similar specimens in the British Museum (Nos. 3907-8). The next form is that named by Owen Balena emarginata (with which B. gibbosa, Owen, appears to be identical/), which is represented by several tympanics in the Museum of the College of Surgeons =, and by one in the British Museum (No. 39016 a); these specimens are absolutely undistinguishable from the tympanics found in the Antwerp Crag, which Van Beneden has named Balenoptera rostratella, a name which must give place to the earlier one applied by Owen, so that the species must be known as Balenoptera emarginata. With regard to the genus Plesiocetus of Van Beneden, I think it advisable to adopt Brandt’s view of including it in his genus Cetotherium, with which Hetero- cetus§, Van Beneden, may also apparently be grouped. The tympanic is readily distinguished from that of Balenoptera by its anteriorly pointed form, the triangular shape of the roughened inferior surface, and the less flattenedinvolucrum. To C. Brialmonti (Van Beneden) I refer an imperfect .axis-vertebra from the Red Crag, in the British Museum (No. 46734); while the smaller C. dubvum (Van Beneden) is represented by two imperfect tympanics in the Museum of the College of Surgeons (Nos. 2852, A and B)||, and probably by some periotics in the British Museum (e. g. No. 30261). Some vertebree in the latter collection probably belong either to this species or to C. Burtina (Van Beneden) ; while others which belong either to the latter or to C. Hupschi (Van Beneden) I have provisionally referred to the last-named species. ‘The still smaller C. brevifrons (Van Beneden 4) is represented by an axis-vertebra in the British, and another in the Ipswich Museum, while it is not * Syn. B. musculoides, Van Beneden; the reasons for adopting the former name will be given in the Cat. Foss. Mamm. Brit. Mus. pt. v. t The form of the involucrum on which Owen distinguished this second species alters with age. t Nos. 2822-2825. Some of the other specimens included under the same head are distinct. § This is really not more than a MS. name. || These numbers do not appear in the published ‘Catalogue,’ but have been entered in MS. by Dr. Garson in the Museum copy. | Syn. Heterocetus brevifrons. 'The type specimens are not figured, and I have identified the English examples by comparison with those in the Brussels Museum. MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. 13 improbable that a small tympanic in the latter collection may also belong to this species. A tympanic from the Red Crag, in the Museum of Practical Geology (represented by a cast in the British Museum), indicates the occurrence of Herpetocetus scaldiensis, Van Beneden, in this country, and No. 2816 * in the Museum of the College of Sur- geonsis asecondexample. The tympanicof this genus (whichexhibits some affinity in the structure of the mandible with the Physeteride) is readily recognized by its egg-like shape, the small and sharply defined involucrum, and the filling-up of the anterior portion of the cavity by osseous matter. Physeteride.—tIn the Physeteride the periotic tf (which, as in the other families of the Odontoceti, is not anchylosed to the tympanic) articulates anteriorly by a smooth facet (a, Pl. I. fig. 6) with the tympanic, and posteriorly is broad and has a distinct median longi- tudinal ridge (6) on the same face for articulation with the free border of the latter bone. The genus Hucetus, Du Bus, which appears to be allied in dental characters to Physeter, is represented Fig. 2.—Kucetus amblyodon, Du Bus. The left periotic ; from the Red Crag. Two thirds nat. size. British Museum (No. 27854). Letters as in Plate IT. I in nearly all Crag collections by many teeth, which belong to the type species EL. amblyodon; the cement is of great thickness, the dentine-core fusiform, and the osteodentine nodular. I provisionally refer to this species = a large left periotic in the British Museum (woodcut, fig. 2), which in the partial production of its posterior extremity more nearly resembles the periotic of Hyperoodon than * Entered in the Catalogue under the head of Balena definita. t+ While the tympanic is the most characteristic bone in the Balenide, the periotic (which is more commonly preserved in the fossil condition) is the one affording the best generic characters in the Physeteride and Delphinide. ¢ On account of its large size and the circumstance that teeth of Hucetus are much commoner than those of Balenodon. — - NE PO I Oe — 14 MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. that of Physeter, and thus, if rightly referred, confirms the generic - distinctness of the present form from the latter. The small Homo- cetus Villerst, Du Bus, is, I believe, represented by a tooth from the Red Crag, in the British Museum (No. 49966), and not improbably by other teeth in the Ipswich Museum. I now come to the genus Balenodon, Owen, which was founded upon an imperfect tooth, whose affinities have given rise to much discussion *. In descateine the type specimen, Owen regarded it as a segment of a complete tooth, and described the central axis as dentine, and the outer coat as cement ; but a comparison with teeth in the Brussels Museum, to which Du Bus applied the name of Scaldicetus Carreti, has shown that the cement has entirely dis- appeared, and that. the axis is really the ossified pulp- cavity, and the outer coat the dentine. The English specimen is specifically identical with the Belgian ones, as the name Balawnodon must therefore supersede Scaldicetus. The complete teeth of the genus have their crowns tipped with enamel. Of the allied but smaller genus Physodon Tt, Gervais, there are teeth in the British Museum from the Red Crag corresponding to those of P. grandis (Du Bus), ~ while one imperfect tooth (No. 44109) may not improbapbly belong to P. fusifornis (Du Bus). ‘The genus Hoplocetus comprehends — _ other Physeteroids with enamel-tipped teeth, which aré characterized _ by the excessive thickness of their cement and the tia of a constriction at the base of the crown. Certain worn (and nio- bably derived) teeth from the Red Crag in the British Museum and other collections appear to indicate the occurrence of the Miocene H. crassidens, Gervais, while others may be referred to the Diestian © H. borgehoutensis, Gervais, and others, again (more doubtfully), to H. curvidens of the same epoch. In the Ziphiine subfamily Hyperoodon is represented by a very perfect right periotic from the Red Crag in the Ipswich Museum (P1. 11. fig. 6). This specimen, which has the accessory ossicle (c) still attached, cannot be distinguished from the corresponding bone of the existing H. rostratus, and evidently indicates the existence either of that or of a closely allied form in the Pliocene ; the occurrence of cervical vertebree of a member of this genus in the Antwerp Crag has been recorded by Prof. Van Benedent. The genus Choneziphius, which appears to be in some respects intermediate between Hyper- oodon and Mesoplodon, and differs from the latter by the non- ossification of the supravomerine cartilage, is represented by the typical C. planirostris (Cuy.). The so-called Aphius planus, Owen, also belongs to the same genus, but the type specimen of that species is not sufficiently perfect to determine whether Choneziphius Packard, Lankester (which is of rather later date), is. really entitled to specific distinction. I refer to this genus a left periotic (PI. I. fig. 7) from the Red Crag, preserved in the Museum of Practical Geology, which * Gervais identified Balenodon with Hoplocetus, while Van Beneden and Lankester thougnt it might be a Squalodon. t Syn. Palgodelphis, Du Bus. ¢ Bull. Ac. R. Belg. sér. 2, vol. x. p. 407 (1860). MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. LS is intermediate between the corresponding bone of Hyperoodon and that of Mesoplodon, and accords well in relative size with the present genus. This bone (in which the accessory ossicle (c) is absent) is nearer to that of Mesoplodon than to Hyperoodon, but approaches the latter in the shortness of the posterior extremity, the large size of the cavity for the accessory ossicle, and the great development of the longitudinal ridge (6) on the tympanic aspect of this portion ; the anterior articular facet («) for the tympanic is also less concave than in Mesoplodon. The latter genus may be taken to include both Belemnoziphius of Huxley and those Crag species placed by Owen in Aiphius which do not belong to Choneziphius. With regard to species, the identity of Owen’s Z. medilineatus with Dioplodon Becant, Gervais, of the Antwerp Crag, has been shown by the latter writer ; and as my own observations in the Brussels Museum fully confirm the view expressed by Du Bus as to the identity of the latter with Ziphius longirostris, Cuvier (the locality of the type specimens of which is unknown), I think we can have no hesitation in adopting the name of Mesoplodon longirostris for this species, which agrees in size with the existing MW. australis. A left periotic (PL. II. fig. 8) belonging either to this or one of the equal-sized species, is preserved in the Jermyn-Street Museum, and is almost undistinguishable from the corresponding bone of M. australis; the accessory ossicle on the posterior portion of the tympanic aspect is absent in the fossil. The characteristic features of the periotic of Mesoplodon are the production and pointed extremity of the posterior portion, the com- paratively small vertical height of the longitudinal articular ridge on the tympanic aspect of the same, the sma!l size and oval shape of the accessory ossicle, and the deep transverse concavity of the anterior articular facet for the tympanic. The other described Crag species are M. tenwrostris (Owen), MW. qibbus (Owen), WM. angustus (Owen), M. angulatus (Owen), and MW. compressus * (Huxley); and to these may perhaps be added a form of which there is a rostrum in the Ipswich Museum to which the MS. name of WM. Floweri has been applied by Mr. Canham 7. Squalodontide.—The Crag Squalodon, of which there are saeepal molar teeth in the Ipswich Museum, may in all probability, as Prof, Lankester suggests, be identified with ‘the large S. UE ROE Van Beneden. Delphinide.— The periotic of this family (PI. IT. fig. 11) is distin- guished by the grooving of the anterior facet (a) for articulation with the tympanic, and the narrowness of the posterior tympanic surface, on which the ridge for articulation with the free border of the tympanic is ill-defined and situated close to one edge. The occurrence in the Red Crag of an Orca considerably smaller than the existing O. gladiator is indicated by a right periotic (Pl. II. fig. 9) in the Museum-of Practical Geology, and by an unworn and very perfect tooth (Pl. II. fig. 10) collected by Dr.J. K. Taylor and preserved * Belemnoziphius compressus, Huxley, appears identical with Ziphius come pressus, Owen. t See Flower, Cat. Vert. Mus. R. Coll. Surg. pt. 2, p. 562, No. 2915 (1884). 16 MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. in the Ipswich Museum. The periotic agrees very closely in structure with a specimen of the corresponding bone of O. gladiator in the Museum of the College of Surgeons, and accords in relative size with the tooth. As Iam unable to distinguish the latter from the teeth of the small Orca citoniensis, Capellini*, from the Pliocene of Italy, I am disposed to refer the English form to that species. The next form for consideration is that to which Prof. Lankester + applied the name Del- phinus uncidens (the generic term being used in the Linnean sense), with which D. orcoides of the same author may be united, since the larger teeth to which the latter name was applied are merely the hinder ones of the same species. Some confusion occurs in the description of the larger teeth, since they are stated to agree in size with those of Pseudorca and Orca ~, whereas they really corre- spond in this and other respects with those of Globicephalus, to which genus they may be referred. The evidence for this reference does not, however, depend solely upon the teeth, since there is in the British Museum a very beautiful associated left periotic and tym- pauic from the Coralline Crag (the former bone being represented in Pl. I. fig. 11), which agree precisely in size with the corresponding bones of G. melas, and only present slight structural differences of specific value. Rolled periotics and tympanics of this type are of extremely common occurrence in the Red Crag, an example of the former being represented in pl. viil. figs. 2, 3 of Prof. Lankester’s memoir. To render the foregoing evidence absolutely conclusive, the British Museum possesses a lumbar yertebra (No. 28271) from the Red Crag which is undistinguishable from the corresponding bone of G. melas. There are several less perfect vertebrae of the same type in the latter collection, while some unnamed vertebre in the Brussels Museum apparently indicate the occurrence of the same species in the Antwerp Crag. ‘The last form I have to notice is one indicated by numerous periotics and tympanics in the British Museum and other collections, which indicate a Dolphin agreeing in size with the existing Lagenorhynchus acutus ; I have not, however, been able to determine the genus of this type, which may include more than one species, and may be identical with one or both of two Belgian species to which Prof. Van Beneden has applied the name of Del- phinus Wasu and D. Delannoyi (the generic term being used in a wide sense). The specimens in the Brussels Museum do not, however, include any examples of the periotic, so that I could not institute any comparison between the Belgian and the English specimens. I may conclude this paper with a list of the well-authenticated $ species of Cetacea occurring in the Red and Coralline Crag, those species of which the identification is doubtful being indicated by a query. * Mem. Ac. Sci. Ist. Bologna, ser. 4, vol. iv. p. 670 (1883). t+ Ann. & Mag. Nat. Hist. ser. 3, vol. xiv. p. 856 (1864). ¢ Mentioned as species of Delphinus in Prof. Lankester’s memoir. § I omit a few forms which have been erroneously recorded from the Crag or of which the description is too vague to admit of identification. MR. R. LYDEKKER ON THE CETACEKA OF THE SUFFOLK CRAG. ey: G: 8. BaLANIDZA. Balena affinis, Owen. primigema, Van Beneden. msignis (Van Beneden). balenopsis (Van Beneden). Megaptera affims, Van Beneden. ? sumilis (Van Beneden). nunuta (Van Beneden). Balenoptera definita (Owen). Goropi, Van Beneden. borealina, Van Beneden. emarginata (Owen). Cetothertum Brialmonti (Van Beneden). dubwwm (Van Beneden). —— ? Hupschi (Van Beneden). brevifrons (Van Beneden). Herpetocetus scaldiensis, Van Beneden. PHYSETERIDA. Eucetus amblyodon, Du Bus, Homocetus Villersit, Du Bus. Balenodon physaloides, Owen. Physodon grandis (Du Bus). ? fustfornus (Du Bus). Hoplocetus crassidens, Gervais. borgehoutensis, Gervais. ? curvidens, Gervais. Hyperoodon, sp. Choneziphius planirostris (Cuvier). —-- planus (Owen). Packardi, Lankester. Mesoplodon longirostris (Cuvier). -—— tenuirostris (Owen). grbbus (Owen). angustus (Owen). angulatus (Owen). compressus (Huxley). — Flower, Canham, MS. SQUALODONTID A. Squalodon antwerprensis, Van Beneden. DELPHINIDZ. Orca citonrensis, Capellini. Globicephalus uncidens (Lankester). Delphinoid, gen. non det. No. 169. Cc LLC 18 MR. R. LYDEKKER ON THE CETACEA OF THE SUFFOLK CRAG. EXPLANATION OF PLATE II. Figs. 1, la. Balena primigenia, Van Beneden,. var. B. The imperfect right tympanic; from the Red Crag. Museum of Practical Geology. 2, 2a. Balena primigenia, Van Beneden, var. D. The imperfect right tympanic; from the Red Crag. British Museum (No. 43399). 3, 3a. Balenoptera definita (Owen). The imperfect left tympanic; from the Red Crag. Ipswich Museum. 4, 4a, Megaptera affinis (Van Beneden). The imperfect immature right tympanic; from the Coralline Crag. Museum of Practical Geology. 5, 5a. Megaptera minuta (Van Beneden). The imperfect left tympanic ; from the Coralline Crag. Ipswich Museum. 6. Hyperoodon, sp. The right periotic; from the Red Crag. Ipswich Museum. . Choneziphius planirostris (Cuv.). The left periotic ; from the Red Crag. Museum of Practical Geology. 8. Mesoplodon (? longirostris [Cuv.]). The left periotic; from the Red Crag. Museum of Practical Geology. 9. Orca citoniensis, Capellini. The right periotic; from the Red Crag. Museum of Practical Geology. 10. Ditto. A tooth; from the Red Crag. Ipswich Museum. ll. Globicephalus uncidens (Lank.). The left periotic ; from the Coralline Crag. British Museum (No. 36657). Figs. 1, 2, 3, one half, figs. 4, 5, two thirds, figs. 6, 7, 8,9, 10, 11, nat. size. All the tympanics are viewed from the inner and inferior, and the periotics from the tympanic aspect. a, anterior articular facet for tympanic; 4, posterior articular ridge for tympanic; ¢, accessory ossicle, or hollow for the same; d, e, f mark the homology of the ridges and hollows in the different bones; ag, the capsule containing the semicircular canals. wh Discussion. Mr. Newton regretted the absence of Prof. Flower. He had tried to determine some of the specimens himself, and recognized how very difficult a task it was. He complimented Mr. Lydekker on his work. With regard to the fossil Physeteroid teeth, he was under the impression that there was more cement in them than in recent teeth. Mr. Lyprxxer, in reply, said his remark as to the absence of cement only referred to the type specimen of Balenodon. ¥ del. et lith. Quart. Journ. Geol. Soc. Vol. XLII. Pl. vu Mantern Bros. MR. R. LYDEKKER ON A JAW OF HYOTHERIUM. 19 3. Description of a Jaw of Hyoturrium, from the Puiocenn of Inpia. By R. Lyppxxer, Esq., B.A., F.G.S., &c. (Read No- vember 3, 1886.) I am again indebted to Col. J. W. Watson, the Political Resident in Kattiawar, for an interesting addition to our knowledge of the Siwalik fauna of Perim Island, on the western coast of India. The specimen in question (which Col. Watson has presented to the British Museum) is a portion of the left maxilla, with the three true molars, of a species of Hyotherawm, which is apparently distinct from any named form. The fragment, of which an oral view is given in the accompanying woodcut, has been slightly water-worn, but not to such an extent as to damage it materially; the first molar has the dentine of the summits of the columns exposed by attrition, while the third molar is scarcely affected by such action. The teeth carry Hyotherium perimense. Part of the left maxilla : from the Siwaliks of Perum Island. (Nat. size.) (British Museum. No. M. 3501.) the usual four main columns, with accessory columns on the inner side of the median longitudinal cleft, and have a well-marked and crenulated cingulum on the inner and fore-and-aft surfaces. The erowns of the first and second molars are squared and rather broader than long, while that of the third tooth has its postero-internal angle produced and its outer border sloping towards the median line. The specimen may without doubt be referred to the genus Hyotherium, in the sense in which (following the lead of the late Prof. Peters) I have employed that term in the ‘Catalogue of the Fossil Mammalia in the British Museum ’*, and we may accordingly proceed to compare it with the named "European + and Asiatic * Part 11. pp. 253-258 (1885). t+ A partial synonymy of the more important Huropean species is given in the work cited. It has been subsequently stated by Dr. Max Schlosser that Cheropotamus steinheimensis, Fraas, is the same as H. Semmeringi. c2 20 MR. RB. LYDEKKER ON A JAW OF HYOTHERIUM. species of that genus, since its distinctness from the American forms may be taken for granted. Before, however, making this comparison, it is necessary to observe that I have already described and figured* a fragment of the mandible of a Hyothervum from Perim Island + containing the second true molar, which, from the great relative width of the tooth, I considered might probably indicate a new species. Since the tooth of that specimen agrees precisely in relative size with the corresponding molar of the jaw under consideration, it may be safely regarded as belonging to the same species. With regard to the Kuropean species the present form is distin- guished from H. typwm ¢ (ranging from the Quercy phosphorites to the Middle Miocene of Georgensmind) not only by its superior size but by the production of the postero-internal angle of the third upper true molar. Confining these comparisons to the larger species like H. Waterhouse: and H. Semmeringt, it will be found that the present form agrees with the first-named species§$ in size, but is distinguished by the relatively wider teeth, the presence of four distinct columns on m. 3, the greater development of the accessory columns, and the absence of an inner cingulum to the upper true molars. With regard to H. Semmering? || the upper molars of our specimen are rather smaller than the teeth of that species See by Peters in the‘ Denkschr. k. Ak. Wiss. Wien,’ vol. xxix. pl.1. fig. 1, but are otherwise very similar, m.3 of the Perin Jaw agreeing very closely with the specimen represented in fig. 3 of the same plate. The upper teeth appear, however, rather Wider than those of H. Semmeringr, and the lower molar is decidedly wider. This difference, coupled with the improbability of a species which died out in Europe after the Middle Miocene being identical with an Indian Pliocene form, renders it probable that the present form is distinct from A. Semmeringi, although it is certainly allied. The only species from India to which a distinct name has been assigned is H. sindzense 4], which occurs in the Lower Siwaliks of Sind. ‘The typical specimens of that species indicate an animal equal in size to the largest race of H. Semmeringi, and apparently so closely allied that it is very difficult to find any distinctive characters from the cheek-teeth on which the species is founded. With these typical specimens are found other teeth in regard to which it is uncertain whether they belong to small individuals of the same or to a distinct species ; the associated lower teeth (which may belong to both the larger and smaller forms) are of a much narrower type than the lower molar from Perim. The type * «Palwontologia Indica’ (Mem. Geol. Surv. Ind.), ser. 10, vol. iii. p. 97, pl. xii. fig. 5. + The specimen was reported to be from Perim Island, and its mineral con- dition indicates that this is certainly correct. { Syn. H, Meissneri. § See Filhol. ‘Ann. Sci. Géol.’ vol. xi. art. 1, pl. vi. (1880). | Syn. Palgocherus major, Pomel. €| ‘ Palzontologia Indica,’ op. cit. pp. 95-97, pl. xii. MR. R. LYDEKKER ON A JAW OF HYOTHERIUM, 21 maxilla of the Sind species (‘ Pal. Ind.’ op. cit. pl. xii. fig. 6), which contains the Jast two molars in a much worn condition, belongs to a considerably larger animal than the Perim maxilla, the length of the two teeth of the former being 1°45 against 1:29 in the latter ; the talon of m.8 in the former is also broader and the external cingulum less developed. The smaller Sind upper teeth agree in size with those of the Perim jaw. If, then, we agree to confine the name H. sindiense to the larger Sind form, it would appear that the difference in size would be a specific character in the case of the Perim form; while if, on the other hand, we extend the name H. sindiense to all the Sind speci- mens, the breadth of the lower teeth would likewise point to the specific distinctness of the former. Provisionally, therefore, regarding the Perim specimens as distinct from H. sindiense, the form to which they belong may be named H. perimense. This species may be defined as equal in size to H. Waterhousei, but distinguished by its wider molars, in which respect it approaches H. Semmeringt and H. sindiense, although differing from the former by the greater width of the lower molars, and from the latter either by its inferior size, or by its wider lower molars, or by both these two characters. Apart, however, from the minor question of specific distinctness, the occurrence of Hyothertum in the Siwaliks of Perim Island in association with highly specialized ruminants like Bramatherwm, Gtraffa, and Antelopes of modern African types is of very considerable interest, and is one more instance of that remarkable survival in the Kast of generic forms long after they had passed away from Kurope— a circumstance which was, I believe, first brought to notice by Dr. Blanford. In Europe the genus first appeared in the Quercy phosphorites, was exceedingly abundant in the freshwater beds of St. Gérand-le-Puy, and apparently disappeared after the Middle Miocene of Sansan and Steinheim. In India it was apparently abundant in the Lower Siwaliks of Sind, which are certainly not older than the topmost Miocene, and persisted into the Pliocene of Perim, where, however, it appears to have been very rare. The Siwaliks of Perim appear to be probably intermediate in age between the Lower Siwaliks of Sind and the typical Upper Siwaliks of the Eastern Himalaya, since while they contain several older forms like Dinotherium and Mastodon pandt- oms common to the former, they also contain newer types not found in those beds. In the Perim beds Hyotherium and Sus are found associated, although the latter is very common and the former very rare, this association being parallelled by the occurrence of Hipparion and Equus in the Eastern Siwaliks. I will conclude this paper with a few remarks on the affinities of Fyotherium. In the first place, the strongly-marked brachyodontism of the genus, the simple structure of the molars, and the circumstance that the last true molar comes into use at a period when the first tooth of the same series is but slightly worn, at once shows the extremely generalized nature of the genus. In structure the true 22 MR. R. LYDEKKER ON A JAW OF HYOTHERIUM. molars are:intermediate between those of Cheropotamus and Sus — those species in which the molars are widest and there is no talon to m. 3 (7, typum) being nearest to the former, while those in which the width of the molars is less and the talon of m.3 well developed (H. Watzrhouser) come closer to the latter. In certain _ examples referred by Dr. Filhol (op. cit.) to H. typwm there is only one external column to pm. 4, which thus shows a retention of a characteristic of Charopotamus. The latter writer has thought that Hyotherium should not be regarded as the direct ancestor either of Sus or Dicotyles ; ; but from the character of its dentition, its wide dis- tribution, its geological horizon, and the absence of any ‘other known form which com occupy such a position, I have long had great doubt as to the correctness of this conclusion, and have expressed myself to the effect that the genus must have been at least closely allied to such ancestral form; and I am now pleased to observe that Dr. Max Schlosser *, of Munich, is of opinion that Hyotherium really occupies a middle position between the modern Sus and Dicotyles and the Upper Eocene (Oligocene) Cheeropotamide, in the sense in which the latter term is employed hy Prof. Flower and myself. Starting from that family, a line of evolution may be traced in one direction from the type genus to Anthracotherium, Hyopotamus, and the tetracuspid Selenodonts, while another line may be traced through Cebocherus to Hyotherium, Hippohyus, Dicotyles, Sus, and Phaco- cherus. Dicotyles has attained an excessive specialization in respect of the upper premolars (which are as complex as the true molars), while in Sus the specialization has been more confined to the true molars; and it is noteworthy that in the specialization of the cheek- dentition of the higher species of the latter genus, while the premolars and first and second true molars only gain a moderate increase in height and complexity, the last true molar becomes enormously developed posteriorly, and does not come into use until the first true molar is almost worn away. ‘This line of specialization culminates in Phacocherus, where all the anterior cheek-teeth may disappear in the adult, and to a certain extent is analogous to the peculiar dental development characteristic of the Proboscidea. Those species of Sus which present the greatest specialization in this respect occur in the later Tertiaries of India and North Africa, the common living species (S. cristatus) of the former country being probably a descendant of the group which has lost the extreme dental develop- ment characteristic of the Pliocene species (S. Falconeri) +. As examples of species retaining a primitive type of dentition, may be mentioned Sus andamanensis of the Andamans, Sus barbatus of Borneo, and the River-hogs (Potamochwrus) of Africa. At least in the case of the first-mentioned species the retention of a generalized character may be attributed to the absence of competition, * Morphol. Jahrbuch, vol. xii. pp. 89-92 (1886). t Dr. Max Schlosser prefers to place Cebocherus in the Suide, and to merge Cheropotamus in the Anthracotheride. t For the relations of these species see ‘ Palzontologica Indica,’ ser. 10, vol. iv. pt. 2 (1886). MR. R. LYDEKKER ON A JAW OF HYOTHERIUM. 23 Discussion. Dr. Branrorp described the Island of Perim and the mode of occurrence of the fossils, and showed that the age of the beds was but roughly indicated by their relations to those on the mainland, and was better determined, as had been done by Mr. Lydekker, by the affinities of the fossils with those in the Sind beds, the age of which was accurately demonstrated by marine fossils. 24 PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. 4, On a new Genus of MADREPORARIA (GLYPHASTR@A ), with REMARKS on the MorpHotoey of GrypHAstRmA Forsxsi, Hd. & H., from the Trrrrartes of Maryzanp, U.S. By Prof. P. Mart Duncan, M.B., F.R.S., F.G.S., &e. (Read December 1, 1886.) ~[Puare IIT.] Many years since, the late Dr. 8. P. Woodward drew my attention to some very fine specimens of Septastrea Forbesi, Kd. & H., in the British Museum, and lately a well-preserved specimen has been sent to me from the Philosophical Institution at Scarborough. There has always been a doubt in my mind regarding the classifi- catory position of this large branching Tertiary species, and the examination of the specimen lately sent confirms the impression that the species differs so much from the Mesozoic Septastree that it cannot remain in the same genus, although it must still be placed in the Goniastrxoid alliance. The species mentioned in the ‘Histoire Naturelle des Coral- liaires’ by Milne-Kdwards and Jules Haime, described by M. de Fromentel in his ‘ Introduction a Vétude des Polypiers,’ and pub- lished by myself in the “ Monograph of the British Fossil Corals ” (Pal. Soc. Lond.), with one exception, have the axial space nearly or quite open, and the columella is either absent or very rudimentary. But the species named after the late H. Forbes*, I find, has the axial space completely closed, either by united septal ends with some additional tissue, or by a columella, which, by uniting with a number of septal ends and being increased in bulk by a remarkable dissepimental tissue, forms a very projecting central mass in perfect and full-grown calices. | The genus Septastrea originated with dOrbigny in 1849, and the diagnosis he gave was partly reproduced by Milne-Edwards and Jules Haime in 18577. The species described in the first instance were from the Hocene and Miocene of France and the supposed Miocene of Maryland. A columella is not noticed in the descriptions of any of these types, and it is said, in the generic diagnosis, to be so definitely absent that the want clearly distin- guishes Septastrea from Gonastrea, Kd. & H. The following was the diagnosis published by Milne-Edwards and Jules Haime from d’Orbigny :—-“ The corallum is either in the shape of a convex mass or is subdendroid. The calices are poly- gonal, and their margins are united to those of the neighbouring calices and ordinarily show an extremely delicate line of separation. The septa are large and appear to be formed of perfect laminae, and the endothecal dissepiments are well developed. © Columella and pali wanting. Multiplication by fissiparity.” * M.-Ed. & J. H. Ann. des Sci. Nat. 3° sér. t. xii. p. 164 (1850), and Hist. Nat. des Corall. vol. ii. p.450. The fossils described were said to be in the collec- tion of the Geological Survey of England and in the Bonn Museum. t Hist. Nat. des Corall. vol. ii. p. 449. PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. 25 The genus was placed by M.-Edwards and J. Haime in the family Astrzide, and in a group in which growth took place by means of fissiparity. The Mesozoic species described by M. de Fromentel and by myself enter the genus thus diagnosed, and the only important modification which I made in revising the genus was to introduce the necessary statement that increase took place by gemmation as well as by fissiparous division of the corallites*. But the genus was included by me in an alliance, the Goniastreoid, of several genera, which is characterized by the forms having the corallites united by their walls more or less completely, and without ccenenchyma serial growth not occurring. A very perfect siliceous specimen of the Maryland species gave the following characters :— The specimen is generally perfect in its details and once formed a portion of a very large branching colony and was undoubtedly a reef- builder. The fracture across the stem resembles those which occur in large specimens of the genus Madrepora at the present day during violent storms. The outside of the coral is covered with calices in a very perfect condition, and the delicate granular orna- mentation of the septa and of the top of a dome of endotheca which fills up the axis and calicular fossa is still to be seen. An excellent natural section of the corallites in the axis of the stem has been the result of fracture. The section shows that the axial or parent corallites haye undergone some diminution in the bulk of their walls and septa, and probably this happened during life, for corresponding absorption is seen in many recent forms. On comparing the super- ficiai calices with the sections of their parent axial corallites, very considerable differences will be noticed, and it is evident, after careful examination of this specimen, that had the section alone been present, the description of the details presented by it would not haye enabled any paleontologist to give an accurate diagnosis of the species. On the other hand, were the structures seen on examining the superficial calices to be entirely relied on, mistakes regarding the nature of the endothecal structures and of the dimensions of the columella might have been recorded. The lower endothecal dissepiments are rather stout and horizontal, and are well seen in the axial corallites: and the upper, which are numerous and close near the calices, form perfect oblique or domed floors between the septa, so. as to shut out the interseptal loculi beneath them from the surface. These uppermost dissepiments come up to about the same level at the bottom of the calice, and reach up to within a fractional part of a millimetre from the free edges of the septa and columella (Pl. III. fig. 7). Hence the septa seem to rest upon the upper combined dissepiments and to resemble fine linear growths; two long ones are often, but not invariably, con- tinuous with the columella and reach across the calice, apparently, but not truly, as one long septum. ‘The study of the section of a * « Revision of the Families and Genera of Madreporaria,” Journ. Linn. Soc., Zool. vol. xviii. 1884, p. 103. 26 PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA, stem explains these appearances, and it is seen that the septa are really high near the axis, and narrow, and that although some unite with others at the axial space of a corallite, there are generally traces, and usually very definite proofs, of the presence of a trabecular and non-essential columella, it often being reduced to a mere lamina which is in the path of two opposed large primaries. The structures at the bottom of the calices resemble a solid mass, and might be taken to be very large columelle not very unlike those seen in some rugose corals such as Clisiophyllum and Lonsdalia ; but the true conception of the structures may be obtained by studying the section of the stem and some of the newer calices at the tops of the ramuscules of the upper part of the colony. The theca or wall of one corallite is in contact with those of its neighbours ; but fusion only occurred here and there, and, indeed, in one place there are traces of very slightly projecting costz to be seen running down the outer part of the walls. The union is so decided that the corallites are, and always were, inseparable, and the position of junction is traced by broken lines in the natural transverse section of the axial corallites and by the geometrical grooves at the surface of the colony. Gemmation is seen on the united walls of corallites, and the buds have six septa; it is also observed, in the natural transverse section produced by the fracture of the stem (fig. 2,d), on the surface of the colony amongst the largest calices and also amongst the more rapidly grown calices at the extremity of the stunted branches. Fissiparity is exceptional, but occurs. The crossing of the calices, so generally but not universally, by what appears to be a long thin septum, which consists of two opposite primaries united at the axis, with or without a columella, is very striking in appearance, and it is difficult to understand how it or the filling-up of the axial spaces could have escaped the notice of Milne-Edwards and Jules Haime; for the structures are perfectly evident in their type, which is now in the British Museum. The granulation of the edges of the septa and columella and even of the top of the dissepiments is most distinct and is as characteristic as the linear grooves which separate, in such a geometrical manner, adjacent calices. The colonies of this species attained a considerable size, and their shape was very variable. The type of Milne-Edwards and Jules Haime, now in the national collection in the British Museum, is as large as a man’s hand and wrist, has a more or less cylindrical lower stem, which enlarges upwards, and is, as it were, compressed, the surface being irregularly swollen in places and smooth else- where. There are terminal, subramose, blunt-ended branchlets, and gibbosities resembling nascent branches. In another colony the shape is nearly cylindrical, and there are ill-defined gibbous swellings _on it; the size is less than that of the other. A third specimen in the British Museum is a part of a very large colony which has lost its branchlets and much of its main mass. The shape is hke that of a thick slice of bread, tall, narrow, and wide. Two of the surfaces are large and broad and nearly flat, and a third or edge-surface PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. Dol is long and narrow, and marked by the roots of several branchlets which have been fractured from the main mass, their axial corallites being seen in transverse section. The height is 140 millim.; the breadth is rather greater than the height ; and the thickness is from 34 to 52 millim. In Milne-Edwards and Jules Haime’s rendering of d’Orbigny’s generic definition of Septastrea the words “‘ multiplication by fissi- parity?” occur. The note of interrogation is not repeated in their own description of the genus in the ‘ Histoire Naturelle des Coralliaires.’ Fissiparity occurs evidently enough in the Mesozoic species without a columella and with an open axial space. It is a fact, however, that there is not a single instance of progressing fission in any calice of the type described by the French authors, which is in the British Museum. ‘There are no calices with a figure- of-eight shape, and in none are there small and new septa starting from the sides of the long septum-lke structure which crosses the perfect and full-grown calices. It is quite a mistake to state that this striking feature has to do with fissiparity. In the specimen belonging to the Scarborough Philosophical Society’s Museum there is some crowding of the calices at the base of one of the branchlets, and the intercorallite walls there are thin; there is no superficial groove, and the appearance of the septa resembles that of some recent types which are undergoing fissiparity and in which the division is accompanied by very rapid growth (Pl. III. fig. 3). But it is nevertheless true that these appearances may be the result of irregular corallite-growth under the influence of pressure from crowding. The instances of fissiparity are exceptional; but the process existed, for there is a fair example in the fractured surface of the stem of the specimen first examined (fig. 2), but not in Milne- Edwards’s type ; and there is a very remarkable and suggestive in- stance in the smallest of the specimens in the British Museum (figs. 4 and 4'). A section was cut at aslight depth, parallel with the surface, so that sections of corallites were made at a little distance from the calices above. It was evident, on counting the calices and the sectioned corallites, that the former were more numerous than the others, and the reason was because one of the sectioned corallites was divided by fission (fig. 4). The commencement of the process can be traced, and a nipping-in is to be seen with considerable con- fusion of the septa. The long lamina crosses the corallite at right angles to the commencing fission, and that is not what would have been seen had it been a factor in the process. On examining the free surface of the colony corresponding to the sectioned corallite, two calices are noted which have an incomplete wall between them ; moreover a septum will be observed passing from one calice to the other (fig. 4’). These calices are separated from their neighbours by well-developed walls. It appears that the growth of the dividing corallite was rapid. The number of the calices with the long lamina (that is to say, perfect calices) varies in different parts of the colony; and if square patches are separated and the number of calices of all kinds on them 28 PROF, P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. be counted, it will be found that in some with 55 calices 35 have the long lamina and 10 have an indistinct septal arrangement, while the rest have no long structure crossing the calicular fossa. In a patch with 75 calices of many shapes and sizes there are 55 with the elongate structure. The orientation of the lamina differs even in neighbouring calices. The septa are bilamellar, and the evidence of a very irregular and narrow interlamellar space is apparent, sometimes superficially, and invariably in microscopic sections of corallites near the calices. A perfect, full-grown calice has the two opposite primary septa united at the axis by means of a narrow discontinuous columella, which is ornamented in the same manner as the septa, but which, in some instances, has a raised edge (figs. 3, 6, 9, and 10), or they may unite by their inner ends and close partly the axial space with or without the assistance of thickening or of any extra growth (figs. 12, 13, and 14}. In buds the columella.may be distinct, and there are the usual six primaries (fig. 2,d). In large immature calices the six primary septa may converge and unite with a small columella or, what appears to be the more common ease, they do not unite. The ends elongate or twist (fig. 16) and, with the dissepimental tissue, close the axial space. It is this closure, either by a columella which sections prove to be occasionally discontinuous and always non-essential in its method of growth, or by united septal ends, or by twisting and elongation of the septal ends, assisted by the tabula-like upper dissepimental structures, that forms the main distinction between the new genus and Septastr cl. The endotheca is variable in amount, and whilst it is close and thin in some corallites, or parts of corallites, it is distant and stout in others. In some cases the horizontal stout platforms are fairly regular; but, as a rule, although the dissepiments completely close the interseptal loculi and act as tabule, they lack the regularity of those endothecal structures. Thin dissepiments often close the whole of the interseptai loculi at indefinitely placed imtervals in the height of the corallites, and as completely as any tabule (fig. 6). The uppermost dissepiments are those which close in the calicular fossa and reach up close to the free edge of the septa. There are no deep interseptal spaces in the form, and the dissepiments moreover come close to the top of the axis, and, by joining with the septal ends and the intermediate structure (when it exists), help to close the axial space and to form a columella, The upper surface of the dissepi- ments at the bottom of the calices is ornamented with sparsely placed granules, and this very exceptional crnamentation is not seen on the lower dissepiments, having been absorbed during growth. The dissepiments are often very close near to the calices, and the visible one at the bottom of the fossa is close above several others, which seem to have followed the same lines of curvature. It¢ is this festooning of the dissepiments which, when seen in a vertical section of the colony, adds to the old-fashioned appearance of the more or less tumid mass at the base of the calicular fossa (figs. 7 and 8). Probably it was the very tabulate appearance of the endotheca of PROF, P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. 29 the fossil which Lonsdale examined that induced him to name it Columnaria, and the intercalicular groove doubtless intensified the importance of the internal arrangement in his mind. Septastrea has no such dissepimental structures. The necessity of introducing a new genus 1s obvious, for the presence of the structures closing the axial space, and the characters of the dissepiments near and at the bottom of the calice, are of great phy- siological importance. In Septastrea proper the mesenteries would have had abundance of support on the sides of the septa, and the visceral cavity would have been prolonged into the axial space ; but in the form under consideration there is barely any room for inter- septal structures, and the nodule in the axial space would limit the downward extension of the visceral cavity. It is very interesting to notice a columellar structure in this Tertiary reef-builder which is somewhat similar to the axial arrangement in Lonsdalia and Clisio- phyllum. But the laminate columelle of those Paleozoic forms are essential and largely developed, and those of the new form are comparatively insignificant; but there is the same crowding of dissepiments close to the axial space and the same apparent extension of a long primary septum. The following is the diagnosis of the new genus :--- Section MADREPORARIA APOROSA. Family Astrmip@; alliance Gonastrwoida. Genus GLYPHASTRHA, gen. nov. Colony large, subramose; corallites prismatic, more or less perfectly united by their walls and having a discontinuous line of separation between them; calices polygonal and shallow, having polygonal linear grooves between them, and the axial space closed ; septa unequal, minutely serrate or granulate at the free edge, some narrow within and long; columella small, parietal, lamellar, or ribbon-shaped, uniting opposite primaries, or several septa sometimes absent, and then primary septa unite at the axial space ; endotheca well developed, often simulating tabule; dissepiments near the ealice extending upwards close to the free edges of the septa and columella, closing the interseptal loculi and forming with the septa and columella a dome-shaped mass which projects and fills up the bottom of the calicular fossa; pali absent; increased by gemmation from the walls between the calices, and rarely by fissiparity. GiypHastrR#A Forsusi, Kd. & H., sp.; amended. Colony large, with a stout stem terminating in gibbous prominences, resembling aborted branchlets; calices numerous, crowded, irregular in size and shape, hexagonal, pentagonal, and even square in outline, shallow, with broad flattish margins separated by straight linear shallow grooves, which form polygonal shapes around each calice ; septa broad at the margin, reaching the linear groove, subequal at the wall and granular there. There are three perfect cycles of septa 30 PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. and, rarely, some members of a fourth. In the first instance the primaries and secondaries reach the.axis, and the tertiaries do not project much from the wall. Commonly, in full-grown calices, two long slender opposite primaries unite with the columella so as to cross the calice, having the appearance of one very long septum; in other calices the columella unites several septal ends, and the appearance just noticed does not occur; or opposite primaries may unite without a columella. The inner parts of the septa are slender, often wavy, and their granular free part is very low, on account of the occurrence of dissepiments ; upper dissepiments free and gra- nular, uniting with the septa and columella to form a convex mass at the bottom of the calice. Fissiparity rare, and when gemmation occurs the buds have six primaries; height many inches; breadth of the stem 28 to 32 or more millim.; breadth of calices from 1:5 to 6 millim.; depth 1:5 to 3 millim. | Locality. Maryland Tertiary deposits. The only notice which I can find in any American publication of Septastrea Forbesi, Ed. & H., now Glyphastreea Forbesi, Kd. & H., sp., 1s in the “ Check-list of the Invertebrate Fossils of North America,” by Meek, Smithsonian Miscellaneous Coll. vol. vit. 1884, “Tert. Syst. Miocene Epoch.” But there is nothing more than the name and the locality of Maryland mentioned. ‘The form does not appear to have been figured anywhere. Lyell was the first geologist who introduced the corals of Virginia and Maryland to the notice of science, and Lonsdale studied the forms. lLyell’s communication is in the fourth volume of the Pro- ceedings of this Society, p. 547 (1845), and Quart. Journ. Geol. Soc. vol. i. 1845, p. 413. Amongst other corals Lyell collected from Virginia a compound, ramose, cylindrical, lobed or massive and expanded species, which Lonsdale, in a paper in the same volume (p. 497), described as Columnaria (?) sewradiata. He figured the form and gave a magnified view of a calice. I do not think that Edwards and Haime had the opportunity of studying Lonsdale’s type, otherwise they would not have placed it in such a remote genus as Astrangia. It appears, after studying Lonsdale’s careful description, that Meek is correct in placing the so- called Columnaria in the genus Septastrea, as understood by Milne- Edwards and his school, although Lonsdale stated that he could not find proofs of fissiparity on the surface of the corallum. ‘The mag- nified view of the calice given by Lonsdale shows a small columella and the stout parts of the primary and secondary septa near the margin ; moreover he figures and mentions a groove which bounds the calices; but there is union shown between some of the tertiary septa and the secondaries which does not occur in the calices of the other species. Moreover the open condition of the interseptal spaces of the immature calices of Lonsdale’s species is not seen in G. Forbesi; nevertheless the alliance of the species is very close. It appears to me that Lonsdale’s species must stand as Glyphastrea sexradiata, Lonsd., sp. The type of Lonsdale’s species is not in the BOS WE OO AS BA | A OR Oe A PD Quart.Journ. Geol. Soc. Vol. XLII. Pl. I. Mintern Bros. imp. _ GLYPHASTREA FORBES. - —__ > > PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA, 31 collection of the Geological Society. There is, however, a much weathered specimen of Septastrea Forbesi, Ed. & H.,= Glyphastrea Forbesi, with the name of Dr. Koch upon the tablet as that of the collector. The specimen is a very instructive one, and it shows how weathering may destroy all those structures which characterize a species. There is only one calice in the rather large colony which indicates that there was once a small columella, and the intercalicular groove is almost destroyed in every part of the coral. The edges of the neighbouring corallites are often sharp from removal of the inside of the calices. The study of this specimen proves how thoroughly paleontologists may be deceived by describing indifferent specimens. EXPLANATION OF PLATE III. Fig. 1. The colony of Glyphastrea Forbesi, in outline ; nat. size. 2. Part of the fractured stem, magnified. a, corallite undergoing fissi- parity; a@’,a part dividing from a; 34, corallite undergoing fission ; ce, corallite with a confused septal arrangement; d, a bud with six primaries, a secondary septum, and a columella; e, corallite showing a columella; f, corallite commencing fission (compare the part nearest the axis of the stem with a’, in which the process has been completed ). 3. Three weathered corallites, magnified, taken close below the position of the calices; fission in progress in two, and the columella visible in the third. 4, Sections of corallites, one undergoing fission, magnified. Specimen in the British Museum. 4’. Two calices corresponding to the fissiparous corallite of fig. 4, magnified. 5. Some calices, magnified. 6. Section of a corallite showing complete endotheca and a ring-shaped columella, magnified. Specimen in the British Museum. 7. Longitudinal section of a corallite showing close successive endothecal dissepiments below that which closes the calice inferiorly, magnified. British Museum specimen. 8. A similar section showing successive layers of endotheca in relation to a columella, magnified. British Museum specimen. ; 9. Part of a longitudinal section of a corallite showing a discontinuous - columella, magnified. British Museum. a bad \10. The central superficial nodule of a columella, magnified. British Museum. NY. The position of the ribbon-shaped part of the columella, placed between the inner ends of two oppusite primary septa, magnified ; more or | less diagrammatic. 112. Primary septa joining at their inner ends, magnified ; diagram. 13, 14. Junction of septa accompanied by more or less columellar struc- ture In 14; a section magnified. Specimen in British Museum. (457.15. View of septa and columella from above, magnified. British Museum. 19+) -) 16. Twisted septal ends forming a false columella, magnified. Discussion. Dr. Hinpr remarked on the interest attaching to the specimens. He inquired if one of the specimens on the table belonging to the Society was-not the type of M.-Edwards and Haime. He thought the prolongation of the septa across the calice indicated merely a tendency to fiss:parity, and was not a generic character. He was not sure if there was a columella distinct from this prolongation, 32 PROF. P. M. DUNCAN ON A NEW GENUS OF MADREPORARIA. which was only well seen in a few calices. He asked if a section of the coral had been made, as this would show whether there is really a columella or not. Mr. Erxerivcs said there paar several specimens of Sept- astrea Forbest at the British Museum, and they were identical with those on the table. The septa are waved, and they anastomose more than was shown by Dr. Duncan’s figures. The speaker then proceeded to point out some of the other minute characters of the genus Septastrea, and especially showed that the junction of the septa at the commencement of fissiparity was very difficult to recog- nize, but, if seen, was unmistakable. Dr. Duncan, in reply, said the type of M.-Edwards and Haime had been in the Museum of the Geological Survey, and had been sent to the British Museum, consequently he could not lay it on the table. He showed that there was a distinction to be made between the columella and any prolongation of the septa at the commence- ment of fissiparity, and that this could be recognized in the fractured part of the specimen. MR. J. THOMSON ON THE GENUS DIPHYPHYLLUM. 33 5. On the OccuRRENCE of Species of the Genus DipHYPHYLLUM, Lonsdale, in the Lowrr CaRsoniFERous Strata of ScorLann, with a Description of some NEW Spectres and Notices of Varieties. By James Tuomson, Esq., F.G.8., &. (Read March 24, 1886.) [Puates IV. & V.] (Abridged.) Tue object of this communication is to offer evidence in favour of the recognition of the genus Diphyphyllum, which was defined many years since by Lonsdale, and which has not been definitely accepted by any paleontologist, with the exception of M‘Coy. It is proposed to give a slight history of the genus and species, and then to notify the occurrence of all the species with varieties in somewhat remark- able deposits in the Lower Carboniferous series of Scotland, and to describe two new species and a variety of one of them. The facts now brought forward clearly prove the truth of Lonsdale’s diagnosis of the genus, which enters the family Cyatho- phyllide of the Rugosa, and also necessitate the introduction into the generic diagnosis of the words “increase by gemmation and by fissiparity.” The genus Diphyphyllum was defined by Lonsdale in Murchison, Keyserling, and De Verneuil’s ‘Geology of Russia and the Urals’ (appendix, p. 622), and the type of the species D. concinnum, Lonsd., is in the collection of the Geological Society of London. The defi- nition was as follows :—“ A stony lamelliferous polypidom; lamelle exceeding 12, biplated; branched, branches dichotomous; internal structure, triareal—1l, central area intersected by flat, convex, or irregular diaphragms, no persistent axis; 2, intermediate area tra- versed vertically by lamellee, interspaces crossed obliquely or down- wards by extensions of the diaphragms and subordinate plates; 3, outer area traversed by lateral extensions of lamelle, interspaces crossed by arched or vesicular lamin inclined upwards and outwards ; stems not uniformly thickened by external secretions, but occasionally united when in juxtaposition.” In explanation Lonsdale. notices that acicular points arise from the upper surface of the diaphragms (tabule), and sometimes are continuous through the diaphragms above for a short distance, but there is no persistence of this struc- ture so as toforma columella. The corallites are in ramified masses. Diphyphyllum concinnum, Lonsd., is defined as follows in the above-mentioned work, p. 624, pl. A. fig. 4:—“ Stems cylindrical, nearly smooth; crossed externally by close, fine, waved lines, and stronger, unequal, distant bands; lamelle numerous, variable; inner surface of plates furrowed strongly upwards and outwards; central area, diaphragms flat, convex or irregular; intermediate area, prin- cipal lamellz exceeding 30, more or less waved; intermediate very unequal ; interstitial prolongations of diaphragms inclined sharply downwards, accessory plates nearly horizontal ; outer area, lamelle Q. 3. G.8. No-169. D 34 MR. J. THOMSON ON THE OCCURRENCE OF DIPHYPHYLLUM variable in strength and range, interstitial plates largely vesicular : terminal cup deep, lined by edges of the lamelle, no central boss.” Relative proportions of areas not constant. Diameter of corallites 4 to 4°5 lines. Localitics. Carboniferous limestone, Kamensk, Siberian side of the Oural, and Bristol, England. M‘Coy found species of the genus and recognized the increase by fission or fissiparity ; he published his definitions in Ann. & Mag. Nat. Hist. ser. 2, vol. 111., and subsequently in his ‘ Palaeozoic Fossils of Great Britain,’ p. 88 (1855). Diphyphyllum latiseptatum and D. gracile were there added to the English coral-fauna. M‘Coy notices how rare dichotomous branching is amongst the Cyathophyllidz, and that this form of increase distinguishes Diphy- phyllum from Cyathophyllum. He states that there is no axis, and that the corallites are biareal, the large central area being occupied by a strong simple transverse diaphragm, deflected at the cir- cumference, surrounded by a narrow, outer vesicular area. Outer wall thick, radiating lamelle numerous, not reaching the centre. In D. latiseptatum there are 28 primary septa and 28 smaller ones ; D. gracile, which is a small form, has not one half the septal number of the other species. There is no doubt that M‘Coy thoroughly understood Lonsdale’s definition, and that his own specific diagnoses are correct. From the time when M‘Coy wrote, down to the present day, nothing but doubt and denial have been associated with the genus so well distinguished by Lonsdale. Milne-Edwards and Jules Haime (Hist. Nat. des Corall. vol. 11. p. 434, 1860), considered Lonsdale’s species to be the same as M‘Coy’s D. latiseptatwm, and that the genus was founded upon specimens of Lithostrotion in which the axis had been lost. They do not mention the fissiparous increase of the coral- lites at all. Prof. Hall (Pal. New York, vol. 11. p. 113) describes Diplophyllum and separates it from Diphyphyllum, recognizing the affinities of the genera. Billings (Canadian Journ., March 1859) debated the fissiparous method of increase in Lonsdale’s genus, and yet separated it from Lithostrotion on account of the defective axial structures. He, moreover, considered Hall’s genus to be synonymous with Lonsdale’s, which it is not. De Koninck gives an excellent history of the genus in his Rech. sur les Anim. foss. du Terr. Carb. dela Belg. pt. 1, p. 38 (1874). He shows how Lonsdale separated the genus from Lithostrotion on account of the absence of a columella, and criticizes Milne-Edwards and Jules Haime. He does not, however, admit that fissiparity occurs, and maintains that the appearance is due to the rapid coalescence of young individuals which have been really produced by gemmation. He agrees in this respect with M. Ludwig (Zur Pal. des Ourals, p. 14, pl. ii. figs. 4, 5, 7). De Koninck, however, considers that Milne-Kdwards and Jules Haime have admitted the fissiparity, as did, of course, M‘Coy. He reflects upon the mistakes of D’Orbigny and De Fromentel in using the generic name given by Lonsdale for very 9 IN THE LOWER CARBONIFEROUS OF SCOTLAND. 35 different corals from those to which he intended to apply it, namely the fasciculate Lithostrontionts. Nevertheless, M. de Koninck’s reading of Lonsdale’s definition of Diphyphyllum (op. cit. p- 33) does not satisfy those who believe in the fissiparity of the individuals of its species. ‘This is to be regretted, because it is now shown by the Scottish specimens that Lonsdale was correct; and, moreover, in order to complicate matters, there are also forms in the Scottish Carboniferous which agree with De Koninck’s insufficient generic diagnosis, and which may be termed Lonsdale’s Diphyphylla, increasing by gemmation only, and with more or less united coral- lites (see the concluding sentence of this communication). The specimen of Diphyphyllum concinnum, Lonsd., figured by De Koninck does not show fissiparity; but similar slabs are to be obtained in the Scottish Lower Carboniferous, and fissiparity is seen now and then in them, the greater part of the increase being due to gemmation. De Koninck also considers M‘Coy’s D. latiseptatum to be synonymous with D. concinnum, the difference being due to vigorous growth of the first-named coral. Lindstrom, in his useful index to the generic names of the corals of Paleozoic formations (Bihang till k. Svenska Vet.-Akad. Handl. Bd. 8, no. 9, 1883), states that Diphyphyllum, Lonsdale, 1845, has Eridophyllum, Ed. & H.,asasynonym. ‘This is an error, for Hrido- phyllum differs very decidedly ; it does not increase by fissiparity and has rootlets. The presence of several forms which must come within the genus Diphyphytlum, Lonsd., in the Lower Carboniferous strata of Scotland is placed beyond a doubt, and the difficulty is to distinguish species from varieties. Certainly there are four groups of species and some varieties which have been collected, and they may be divided as follows :— 1. The D. concinnum group, with numerous primary and smaller septa, not less than from 45 to 60 in number; endotheca moderate. 2. Large forms with long and shorter septa, about 40 in number ; endotheca in two distinct circles. A new species, D. cylindricum, comes in here, with a second, D. Blackwoodi. 3. Large forms with numerous septa and much endotheca, filling largely the interseptal loculi. Here come in D. latiseptatum, M‘Coy, and two varieties, var. giganteum and var. interruptum. 4, Small forms with small corallites with few septa: D. gracile, M‘Coy. The following old and new species and varieties of the genus Diphyphyllum, Lonsd., occur in the Lower Carboniferous of Scot- land :— DipHyPHYLLUM conctnnum, Lonsd. (Pl. IV. fig. 1.) A variety with smaller corallites than the type, and about 44 septa ; diameter 6 millim. by 8 millim., in the instance of the largest coral- lites. ‘The distribution of the endotheca, tabule. and acicular points is as in the type, and everything ison asmaller scale. The corallites are tall and wide apart. Gemmation appears to be more freyuent D2 36 MR. J. THOMSON ON THE OCCURRENCE OF DIPHYPHYLLUM than fissiparity, and this may occur so that the parent corallite becomes trilobed in transverse outline, and the fission is double instead of single. That this is not a junction of buds can be proved by studying the growth of the septa from the dividing lamine. Locality. Lower Carboniferous, Scotland. Kirtle Bridge and Black- ridge, Dumfries. Var. FurcaTuM (PI. IV. fig. 2). This variety has slightly smaller septa and wider central space than the type. It dees not occur in dense masses. Locality. Near Fenwick, Ayrshire and Corrieburn, Dumbarton. DipnypHyitium Buackwoont, sp.nov. (Pl. IV. fig. 3.) The corallum is in dense fasciculate masses, with corallites of differ- ent sizes, cylindrical, tortuous, close or not, rarely in lateral contact. Epitheca delicate. Diameter 4 to 6 millim. Fossula with a small primary, often indistinct. Septa 15 to 20, according to the size of the corallite, with a similar number of smaller ones (30 to 40 in all), the larger extending inwards considerably, but leaving a wide central space ; they are very thin and delicate near the equally thin wall, and are stouter and decidedly bilaminate at their junction with the innermost endothecal ring; they may extend beyond that. The smaller septa are short, thin near the wall and thicker near the outer endothecal ring. Acicular points rarely exist—ain one corallite out of 14. Endotheca stout between the septa and vesicular; the inner circle of it is often festooned. A vesicular structure is often seen near the wall in the interseptal loculi.. Tabulee large, horizontal in the central area and inclined at the edges towards the underlying tabula; sometimes bent upwards and then having a relation to the fissiparity, which is both single and-double. Localities. Auchenmead, Beith, near Fenwick, Ayrshire ; Boghead, Lesmahagow, Lanarkshire. Var. approximatum. (PI. IV. fig. 4.) This has the ‘‘ rods” very frequently developed. Locality. Boghead, Lesmahagow, Lanarkshire. In a coral with closer corallites than the last, and which might almost be considered to be a variety of it, the septa of the principal series extend so far inwards, and the endotheca is so much legs like internal walls, that I consider it to form a new species :— DipHYPHYLLUM CYLINDRICUM, sp. nov. (PI. IV. figs. 5, 54.) Corallum in dense fasciculate masses, corallites tall and cylindrical, epitheca thin, with narrow growth-rings. Septa few, 18 to 20 large and as many small, the large passing far in and reducing the dimensions of the central area and tabule. The small septa extend about one fourth of the distance of the others. The vesicular endotheca is delicate, in two fairly distinct circles in the interloculi, and some delicate inclined stereoplasm occurs. FF issiparity is frequent and is of both kinds: gemmation also occurs. IN THE LOWER CARBONIFEROUS OF SCOTLAND. 37 Locality. Boghead, Lesmahago; Roughwood and Thirdpart, Beith, Ayrshire. DiPHYPHYLLUM LatisEpTatuM, M‘Coy. (PI. V. fig. 6.) This form must now be separated from D. concinnum, for the specimens show a large corallite with 52 septa in all, longer primary septa than in D. concinnum, and a very considerable vesicular endotheca filling the interseptal loculi, and much more of it than in the species determined by Lonsdale. Both kinds of fissiparity are present. Localities. Corrieburn, Dumbarton, and Fenwick, Ayrshire. There are two varieties of this species, var. gigantewm (Pl. V. figs. 7 and 8) and var. interruptum (PI. V. fig. 9). DrpHYPHYLLUM GRACILE, M‘Coy. (PI. Y. fig. 10.) This is the smallest species of the genus, and the Scottish specimens are fairly undistinguishable from the type. The septal number is small, and there is fissiparity as well as gemmation to be observed in the method of increase of the individuals. The corallites are in tortuous, ascending, and irregular bifurcating masses. Localities. Coteastle near Strathaven ; Braidwood and Brockley, Lesmahagow : Roughwood and Cunningham, Bedland Dalry, Ayr- shire. List of Scottish Lower Carboniferous Species and Varveties of Diphyphyllum, Lonsd. 1. Diphyphyllum concinnum, Lonsd., variety. var. furcatum: 33 2. -- Blackwoodi, sp. nov., and var. approximatum. 3. +: cylindricum, sp. Noy. 4. , latiseptatum, M‘Coy, and vars. gigantewm and interruptum. 5. 9 gracile, M‘Coy. Some of these forms are found in large masses and environed and covered by volcanic ash. It is not too much to believe that some of the variability of the species may have been produced by the rather frequent slight changes of external conditions which must have accompanied the vulcanicity of the Lower Carboniferous age. Indeed, the volcanic ejectamenta appear to have finally destroyed the life of the individuals over the area, for the species are not found in a higher geological horizon. The examination of the numerous species and varieties of the genus established by Lonsdale enables the truth of his description and diagnosis to be appreciated. His only mistake was an omission; for when he stated that the species increased fissiparously, he did not also state, what. has been shown here, that gemmation also occurs. The description given of the tabule by Lonsdale is correct, and so is that of the acicular points sometimes becoming rods which do not extend for any great height in the centre of the corallum. These 38 MR. J. THOMSON ON THE OCCURRENCE OF DIPHYPHYLLUM points rise from the surface of a tabula, and when there are rods they transfix, as it were, several tabule. The rods are rarely seen, but, by searching, some will be found in a somewhat definite per- centage of corallites. The triareal nature of the corallites is to be recognized, but it is a term which has become disused, especially as the endotheca only gives characters of second-rate importance as a rule, The fissiparity is much better shown in the specimens herein de- scribed than it was in those seen by Lonsdale, and there are three kinds of the process. In some corallites bending in and figure of 8 occurs, as in the Mesozoic and Recent Corals, and division took place at the nar- rowing. But usually a ridge grows across the corallite, and septa are formed on either side, and then the ridge, which, for a time, has been partly the wall, separates into two portions. The third method is singular, for two ridges grow towards the centre of a corallite, and one reaches the other at right angles near the axis, and thus the appearance of a trilobed budding is presented ; but it is evident that septa only grow from the ridges, and that would not be the case in buds. After separating, the new corallites grew upwards away from one another. The ridges, which have so much to do with the two commonest kinds of fissiparity, are the extension inwards of oppositely placed large septa; the inner ends unite and shut off the two parts of the corallite, and septa grow from the faces looking towards the new central areas. In another form it appears as if a tabula turned up or grew up at its outer edge and stretched across the corallite at the calice ; it came up to the bottom of the visceral cavity, and then septa grew from both sides of it and fission occurred. Fissiparous growth is a very rare phenomenon amongst the Rugose Corals, and, so far as is known, Diphyphyllum is the only genus in which it occurs. The alliances of the genus need hardly be noticed here, as they have been discussed by Milne-Edwards and Jules Haime, and especially by De Koninck in the work already quoted. The presence in Scotland of a species of a genus which would come _ within that which should receive De Koninck’s D. conconnum (non Lonsdale) has been discovered of late, and it necessitates the re- definition and renaming of the Belgian type, so as to separate it from the fissiparous form. This new genus will form the subject of a future communication. EXPLANATION OF PLATES IV. & V. Prats LV. Fig. 1. Diphyphyllum concinnum, Lonsd., transverse section showing fissiparity. ———, var. furcatum. 3. —— Blackwoodi, Thoms., transverse section. 4, —— ——., var. approximatum, transverse section. 5 cylindricum, Thoms., transverse section; 5 A, longitudinal section of corallites, . Glassoar & CF Tath, ISDS ALP SI f) E (eS lsleis| 3 a | a lAeeala| < 1. Cellaria malvinensis, B................, 45 | 4Z |...1% las ee 2. Membranipora monostachys, B. ...| 45 | %Z |% 3. — lineata, D........ sonpocd| |) Ly SAA cl ael eee I 4, —— Lacroixii, var. grandis, Wb. 45 ceo XIX So ——— ainsi 92 07 A Ol becl 4) ceo nee] bad bosoconne Crag. 6. —— nobilis, Rss. ..... a AG i eedecsace H%|...\%|...|---| 2 |Miocene. 7. ——solidula, Ald. 4 Hincks.. 46 | KAZ]...|3¢|...]... * o—— annulus, MONZo.eveeeccsiecvee| 47 | K [KK K...|---| 2 [Napier Harbour. 9, —— cervicornis, Busk ... senseutros! AY Ie AL NSE) — |. lee Peralwee ce 10. —— spinosa, Q. & G. serssereeee| 48 | HAZ |X i -—— Flemingi, 3... seabdease tO) || Sen Iie lee-|oor|senle--| =O 12. trifolium, S. Wood . sccsod| 24s) || S991 ce! [end joo ood poosercooc Crag. 13. —— occultata, sp. NOV............00002.| 48 | SZ |% 14. Monoporella capensis, B. cecceseeeees] 49] KH [XM..... IK id. —— ——, var. dentata, nov. ......... AQT beeen: 165 CEassatina, We. 2 oo vcciencsec-ns eens 49 | XZ |K\%)...|...|...|2, 5, 6) Whakati. We disjuncta, Manz. ......0..c0c.e000 50 |XEZ(P)|KI.-.|--.|---feee|eeveeeree Pliocene (Italy). 18. —— waipukurensis, sp. noy. .........| 50 |......... KK... 19. Steganoporella neozelanica, B....... 50 | ¥Z |x/Ki*K 20. Micropora lepida, Hincks. ............ 51| *Z |X 21. —— variperforata, sp. noy. ......... D1 | KZ [Kl]. | HEleo |e e ewes Whakati. * A or Z indicates Bae the form is known living in Australia or New Zealand. 1=Curdies Creek. =Mt. Gambier. 38=Bairnsdale. 4=Muddy Creek. 5=Aldinga. pate Cliffs. 44 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS Inst of Species (continued). | | il 3 | | |.ie] 72 Z| \8lz2| € Fe le | Si eee Allies and Localities. ~ lel] slo) S| a (5/2/S\a/5) § o a ay Ray S |"ep|-44 = a] © |siSiote(s| 3 a) ao wllaieial = 22. Membraniporella nitida,Johnst.var.| 52 | %Z |-|% 23. Cribrilina monoceros, Bo teens 52 | HA |XI...14€]...).... 3 |Petane marls. 24, —— figularis, Johnst. 53 | % |...1X]...]--6. 6 |Crag. 25. —— radiata, Moll, var. ‘Endlicheri, ESSIBRG unt saioseses iessesteee seers 15 13)9 boooaedco| boa lope aoe sodllonallactaooude Napier Harbour. 26. Microporella ciliata, Moll.............| 53 | MAZ |X%)ok}.../5€|.... 2 |Whakati. 27. —— Malusii, Aud. 20... cceeeeceeee 54 | KAZ IM]... lec ewes Bird Rock (Victoria). 28. —— macropora, Stol. .......0..c..0+- 54 | XA |.../3€])...]... Toa Chiesa Miocene. 29. —— decorata,Rss., var. palaces iM ean 4a | Seal selae sale 30. —— magnirostris, “MacG. Saseejscenaen | COOL pow Po el ee eee 2,6 31. Mucronella mucronata, Sm. ......... 55 | KA /&I...]... Loos 4,6 32. ——nitida, Verrill ....cccccccceeenes| OF | MA [HK]... 3, 6 |Tommy Gully, Petane. 33. —— preestans, Hincks ..........c0000--- 56 | XZ |.../3€...|.. |...] 1,2 |Petane marls. 34. —— Peachil, Johnst. .......2..-..0000 56] SM |% 35. —— ——, var. octodentata, H. ...... 56 | MZ IKK... 36. —— alvareziana, @’OPD. .......e0.e.0+ BY (ame in Heinen Whakati. 37 CLICUSPISWAUNCKS seeccenee teense: 57 | KAZ I...]...1% 38. —— ——,, var. waipukurensis ...... 551 (3 Raoauneie| Kae * 39. —— porosa, var. Minima.............+. BY CW beadonee tae Sool \41 000| Ison) loooa2000 Petane marls. 40, —— Liversidgei, Woods..............+. G15)|\donaneecdl bee “|,..|...]...] 2 |Mount Gambier. 41. TPADEIIE, (30> TNO ohopcooccncbodusae Gyo) Neane snare XI 42. Smittia reticulata, WHGHACE gogsetenbbos SBM SAW feeleeeleet ...|2, 8, 6|Whakati. 43. —— Landsborovii, Johnst.............) 58 | XA |..)...)36]...)...] 6 44, —— biincisa, W., var. bicuspis, H.| 58 | %Z |.../% 45. —— Napierii, Waters ................+ 59 | KA IKK... eee eee Waurn Ponds (Australia). 46. Porina grandipora, sp. nov. ........| 59 |......... x 7 . : ¥ 47. Lepealie IPOISSONnI, Aad ee en. eeaes oes 59 | KAZ E/E... Whee arbour, 48. —— rectilineata, Hincks.............+ 60 | XZ |34)/3€)...]... “% z Dee 49, Hen Pe llag ees ee ere come teed COs ececec: MISES)... |. .|eccce ees Tommy Gully (Petane). 50. —— pertusa, Hsper,.......s.c0scesere-es 61) % |¥%...)...]... ..| 4 |Waurn Ponds. 51. —— rostrigera, SM. .......0.0-.eeeeeee 61} % |%l...]...)... salen 6 52. —— longipora, MacG.............0.. « 61 | A |.../3€]...146 53. —— semiluna, fss., var. purples Balt GPF lb eaeeeoee | - 54, —— foraminigera, Hincks.. wee] 62) YZ I... 55. —— bistata, sp. nov. .. Pau eae nen | ROL alee seer ie % . 56. Porella marsupium, MagGs it. 62 | 342A |...|34)...}... BAA ae hoe Waurn Ponds. Sly = ———= Ven Outen, Tél a omctnac|| (3) |e a SiS 58. —— concinna, B. . Poesia leery fe cay Wil Rall sal heal do ..| 2 |Tommy Gully (Petane). 59. Hippothoa flagellum, Manz. «0.0... 63 | 4Z |% 60. Schizoporella circinata, MacG.......) 64 | %AZ |.../4¢ 61. —— auriculata, Hass. ......8..........| 64| 3A |sl...[.[..- ...| 2,3 |Tommy Gully (Petane). : 62. —— Ridleyi, MacG....................| 64 | SA |...) 5 63. —— marsupifera, B...............0++.| 65 | HAZ I.../% 64. —— biaperta, Wich..........csc00+0-| 65 | KZA |... 65..-—— cribriliteray FH tnchks:.. seeees-ea2\ 00, || Zio lds tee: eae teen deel eeneeeee Petane marls. 66. ——clavula, Manz. .ic.c..csccsecensens-| OD |...esc0ee fool el Setsltbel Mostae nace Italian Miocene. 67. —— conservata, Waters...............| 65 | YA |%)...|...).-. pon 4 68. —— obliqua,? MacG. .................| 66 | A |...1% r 69. —— cinctipora, #., var. per sonata. 67 | XZ |... % , 70. —— tuberosa, Rss., var. angustata..| 67 |......... welt Giles =——nyaliiman) aera ses iresecece mea ctiam aes 68 | KAZI...) [Hef reeves Tommy Gully (Petane). 72. Cellepora albirostris, Sm. ............ 68 | %A |skl...]...]... %| 6 73. —— tridenticulata, B...............0.0 68 | A |.../€|...]... ...| 5,6 |Yorke’s Peninsula (Aust,). 74. —— coronopus, S. Wood...............| 68 | 3 |S€}...)...).-. Beal 25h) 75. —— costata, MacG. .......ecsereseee-| 68 | SEA JHEl...|...].2-]---[oeceeenes Miocene (Europe). 76. —— decepta, Sp. NOV. ...........6 eee GORI Geese “| | 77. Rhynchopora longirostris, H. ...... 70 | %A |% ‘ 78. Lunulites petaloides, @’ Orb. vise. MOB enmesees Mel eal eeclecs ¥| 2,4 |Bird Rock. BRYOZOA FROM NEW ZEALAND. 45 1. CELLARIA MALVINENSIS, Busk. Cellaria malvinensis, Waters, Quart. Journ. Geol. Soc. vol. xh. p. 285. Loc. Living: various localities in the Southern Hemisphere. Fossil: Australia; Nelson (#.), Waipukurau and Shakespeare Cliff (New Zealand). 2, Mempranipora monostacuys, Busk. (Pl. VI. figs.38 & 6.) =——— Not Membranipora monostachys, Busk, Brit. Mus. Cat. p. 61, pl. xx. For synonyms see Hincks, Brit. Mar. Polyzoa, p. 131. A specimen from Napier has a large spine below the aperture and numerous smaller ones round the opesia. The ovicell, which has not been previously seen in M. monostachys, is subglobose, with a strong rib on the front enclosing a subtriangular or suboval space, which is divided into two equal parts by a median rib. The ovicell, _ In structure, somewhat resembles that of M. aurita, Hincks, and the raised rib on the ovicell occurs in many Membranipore, such as M. lineata, M. galeata, M. wnicorms, M. sophie, M. circumclathrata, M. dentata, &c. This differs from MW. lineata in having a large spine below the opesia, but there is no doubt that this, J. pelosa, and M. pyrula, Hincks, are closely allied. The ovicell is like that of M. valdemumia, Hincks. Miss Jelly has a recent specimen from Napier with similar ovicells. Loc. Fossil: Napier. 3. MEMBRANIPORA LINEATA, L. In a fossil from Shakespeare Cliff the zocecium has a thick border and was surrounded withspines. ‘The ovicell is short, and between the zocecia there are interspersed small cells, with a small, round, or elongate opening ; these I have sometimes called blind cells. | The form of the ovicell seems to indicate that this is J/. lineata ; _ but as there are several species closely allied, it is difficult to speak with certainty in such a case. 4, Mempranrpora Lacrorxir, Aud., var. eranpis. (Pl. VI. fig. 1.) There are several specimens of Membranipora from Napier which I cannot identify with certainty, but which will be recognizable when again found. The opesia, 0-4 millim. long, is oval, occupying nearly a third of the zocecia, and has a distinct border upon which I do not find any spines. The space between the zocecia sometimes bears an avicularium, but more often is divided into two or three spaces, sometimes with punctures. The ovicell, which is unknown in the typical JZ. Lacroivit, is large, raised, globose. This is allied to my WM. tripunctata, but the narrow longitudinal band between the zocecia is wanting. 5. Mempranipora Dumeriti, Aud. (Pl. VI. fig. 4.) Flustra Dumerilu, Aud., Savigny, Descr. de |’ Egypte, pl. x. fig.1 2%, For synonyms see Brit. Mae, Polyzoa, p. 156. 46 MR, A. W. WATERS ON TERTIARY CHILOSTOMATOUS Although the ovicell is wider than usual, I think this must be regarded as M. Dumerilit, and probably the number of synonyms should be largely increased, as there are many fossil Membrantpore described with a small avicularium at the base of each zocecium. In a recent British I. Dumerilit in my collection there is also a Vicarious avicularium with the lower part wide and circular and the mandibular end narrow. A curious mistake has been made in uniting Cribrilina Pouillau to this. This latter is pl. ix. fig. 12 of Audouin; but Alder made a slip between pls. ix. & x., and Busk followed him, evidently without verification. Loc. Living: European seas. Fossil: Crag; Waipukurau. 6. Mewerantpora nosis, Rss. (Pl. VI. figs. 7 & 10.) Membranipora nobilis, Reuss, Foss. Polyp. des Wien. Tertiar- beckens, p. 98, pl. xi. fig. 26. Zoarium adnate. Zocecia oval, surrounded by a border: in one or two cases a vicarious avicularium with semicircular mandible. Ovicell small, smooth, with a border round the central portion. This much resembles M. flustroides, Hincks, in shape and character: but im the fossil the avicularium is larger, the spines are wanting, and the ovicell is somewhat deeper. A round avicularium only occurs in a few Membranipore, such as M. crassimnarginata, H., M. lineata, Manzoni (Bry. of Castrocaro, p. 11, pl. 1 fig. 6), M. flustroides, H. A specimen from Napier has the cells, in part of the colony, very elongate, showing that WV. ovalis, dOrb., is only a modification of this species. Loc. Miocene: Austerlitz. Napier and Petane (N. Z.); Mt. Gambier. . Memsranrpora sotipuna, Alder & Hincks. ID i octal Membranipora solidula, Hincks, Proc. Dublin Univ, Zool. & Bot. Assoc. 11. pt. i. (1860) p. 75; and Brit. Mar. Polyzoa, p. 158, pl. xx. Nile, o Membranipora papulifera, MacGillivray, Trans. Roy. Soe. Vict. vol. xvii. p. 116. Biflustra papulifera, MacGillivray, Zool. of Victoria, decade xi. p- 27, pl. 106. fig. 9. A fossil from Shakespeare Cliff, growing on Entalophora, has the - zocecia plain, suboval, with a thick crenulated border, and a globose ovicell, which is shallow and smooth, with a strong thickened ridge across the upper part. Im size and structure of the ovicell this is just the same as specimens from Hastings and Capri, but I do not ~ find any nodules. This, however, in several other species is not a constant character. A specimen from Waipukurau Gorge, which was sent to me queried as \/. papulijera, is of the same size as the one from Shakespeare Cliff. Loc. Living: Antrim, Guernsey, Hastings (#.), Capri (A. W.), BRYOZOA FROM NEW ZEALAND. AGT Port Phillip Heads (MacG.), New Zealand (Miss Jelly). Fossil : Shakespeare Cliff (Wanganui), Waipukurau Gorge. 8. Mempranrpora annutus, Manz. (Pl. VI. figs. 2,5, & 9.) Membranipora annulus, Manzoni, Bry. foss. Ital. 4a cont. p. 7, pl. i. fig. 6(?); and Bri. di Castrocaro, p. 12, pl. 1. fig. 9. Membranipora dentata, Waters, Quart. Journ. Geol. Soc. vol. XXxXVili. p. 263, pl. vil. fig. 14. Membranipora galeata, Busk, Brit. Mus. Cat. p. 62, pl. lxv. fig. 5; “‘ Zool. of Kerguelen Island,” Phil. Trans. clxviii. p. 195. There are a number of closely allied forms which, through varia- tions in the shape of the opesial opening, often differ considerably in appearance, but agree in having a central avicularium, supported by two strong spines on each side, sometimes cervicorn, and an ovicell widely open with a raised line arching across the front, a short distance above the opening, enclosing a narrow depressed area. These allies are MW. patula, Hincks, M. cervicornis, B., Flustrellaria dentata, d’Orb. The present form, which I at first thought should be called UW. dentata, dOrb., has usually an oval opening; MW. patula has the lower edge straight ; MW. cervicoriis, B., which is no doubt the same as M. perversa, Waters, fossil from Mt. Gambier, has the opesia - usually nearly straight above and rounded below; but in a large colony of any of these species opesia will be found with very different shapes. In the New-Zealand fussils the large avicularium on the ovicell is directed downwards to the distal wall. One specimen from Napier and one from Waipukurau are bila- -minate, but the others are adnate. We have also seen MW. cervi- corns (perversa, W.) in the Vincularia-form. Some specimens have an avicularium below the opesia. An examination of the British-Museum specimens of Membrani- pora galeata, B., made since my plates were prepared, shows that this is identical with the fossil. The depressed area on the ovicell, which Mr. Busk seems to have overlooked, is very marked ; occasionally there are two avicularia, and the cells without ovicells, with the avicularian chamber projecting forwards, exactly resemble my fig. 5. As Mr. Busk’s description was quite insufficient, it will be best to retain Manzoni’s name. Loc. Living: Swains Bay, E. Falkland, in 4-10 fath. (Darwin, fide Busk). Fossil: Pliocene of Castell-Arquato, Parlascio, Orciano, Castrocaro (M/.); Mt. Gambier (Australia); Napier, Waipukurau and Petane (New Zealand). 9. MemBRANIPORA CERVICORNIS, Busk (non Haswell). Membranipora cervicornis, Busk, Cat. Mar. Polyzoa, p. 60, pl. e. fig. 3; MacGillivray, Zool. of Victoria, decade ui. p. 32, pl. xxv. fig. 8; Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. vu. p. 153. 48 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS Membranipora perversa, Waters, Quart. Journ. Geol. Soc. vol. xxxvii. p. 264, pl. ix. fig. 32. Amphiblestrum cervicorne, Busk, Rep. ‘ Challenger,’ Polyzoa, p. 66. Loc. Living: Williamstown (Victoria), Curtis Island (Z.). Station 162, 38 fath. (B.), Bondi Bay (N.S. Wales), Adelaide and Port Phillip iieade (A. W. W. coll.). Fossil: Mt. Gambier and Napier. 10. Mremprantpora spinosa, Quoy & Gaimard. (PI. VIII. fig. 32.) Flustra spinosa, Q. & G. Voy. de l’Astrolabe. 3 Membranipora ciliata, MacGillivray, Trans. R. Soc. Vict. 1868, p. 7; ibid. vol. xvii. p. 3, fig. 11; Zoology of Victoria, decade iii. p. 30, pl. xxv. fig. 3. Membranipora spinosa, Busk, Trans. Roy. Soe. vol. clxviii. p. 195, pl. x. fig. 3; and ‘Challenger’ Report on the Polyzoa, p. 64; Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. vii. p. 150. C Chaperi wa austr alas, Jullien, “ Bry. Cheil.” Bull. Soc. Zool. 1881, vol. vi. p. 1 (sep.). In the fossil from Napier and in a recent specimen from New Zealand there is an elongate lateral chamber on each side below the operculum, and a similar structure occurs also in MM. annulus, but rather lower down. ‘The length of the opesial opening is in both about 0°25 millim. Loc. Living: Victoria, Kerguelen Island, 8. Patagonia, N. S. Wales, New Zealand. Fossil: Napier, N. Zealand. 11. Mempranipora Frieminert, Busk. Membranipora Flemingu, Busk, Cat. B. M. ui. p. 58, a Ixxxiv. figs. 3-5 only; Hincks, Brit. Mar. Poly zoa, p. 162, pl. xxi. figs. 1-3 ; Waters, Quart. Journ. Geol. Soc. vol. xli. p. 288. : Loc. Living: European Seas. Fossil: Aldinga eae) Napier. 12. Mempranrpora TRIFOLIUM, S. Wood. LA LA, For synonyms see Hincks, Brit. Mar. Polyzoa, p. 167. The fossil from Napier has zocecia about half as large again as specimens in my collection from the English Crag. The opesia of the Crag specimens are 0°15 millim. wide; these are 0°25 mm., and MM. appendiculata, which is related (see Q.J.G.S. vol. xxii. p. 504), has the opesia about 0:4 millim. wide. Iam much inclined to think that it would be best to follow Smitt and call this M. Flemingw, var. trifolium. In the New-Zealand fossil the ovicell is flatter on the front than I have before seen. Loc. Living: Northern Seas. Fossil: Crag, and Napier. 18. MEMBRANIPORA OCCULTATA, Sp. Nov. oF VI. figs. 12, 13, and Pl. VIII. fig. 40.) Zoarium adnate. Zocecia quadrate, siege inwards towards the opesia, with three spines on the upper border. Opesia nearly straight below, rounded above, with the sides nearly straight, and a broad serrated edge or denticle on the proximal border. In the BRYOZOA FROM NEW ZEALAND. 49 older parts there is a thick calcareous deposit between the cells, so that the mouth is buried at the bottom of a deep cavernous opening, and in the raised calcareous part there are numerous triangular avicularia. A number of the chief characters remind us of Rhynchopora pro- funda, MacGillivray (New or Little-known Polyzoa, pt. iii. p. 2, fig. 8), and possibly some of the characters are hidden by the calcareous growth in MacGillivray’s specimen. I should not have been able to make out all the characters from the fossils, but, having seen them in recent specimens, the fossils became quite clear. Loc. Living: New Zealand. Fossil: Napier (N. Z.). 14. Monoporenia capensis, Busk. Amphiblestrum capense, Busk, ‘Challenger’ Report on the Poly- z0a, p. 6/, pl. xxii, fig. 3. Such a form as the present shows at what a great disadvantage the paleontologist is placed in consequence of being unable to find out the form of the Bryozoal covers, for there are many species of Membranipora resembling the present species in the shape of the opening; but these, such as WM. dentata, M. angulosa, &c., have a small opercular aperture in the membrane covering the opesia. In this species, on the other hand, the opening is entirely closed by a subcircular or elliptical operculum. In a recent specimen in my collection, from Algoa Bay, South Africa, the zoarium is erect, cylindrical, or subcompressed, just as figured by Busk, and some cells have the two spines as described ; but the majority are without spines, and in none of the fossils do 1 find any traces of them. The Napier and Waipukurau fossils are both adnate, whereas the one from Shakespeare Cliff is a flat bilaminate fragment. Opesia of all 0°3 mm. wide. Both /lustrellaria tubu- losa, d’Orb. (Pal. Fr. pl..727. fig. 10), and Biflustra Prazdki, Novak (Bohm. Kreide, p. 18, pl. ui. figs. 20-25), are closely allied to this. Loe. Living: Simon’s Bay, Cape of Good Hope (B.); Algoa Bay (W.). Fossil: Waipukurau, Wanganui, and Napier. 15. Monoporetia capensis, B., var. pentTaTA, nov. (Pl. VIII. fig. 39.) There is a specimen from Napier which, on account of a curious structure, it may be best to regard as a variety. In the upper © part of the zoccium there appear to be two denticles extending some little distance below the aperture, but these are only a pro- longation of a tube from one zocecium to another ; in the middle of _ this tube is the rosette-plate. The distal rosette-plate is, in many cases (as, for example, Lepralia foliacea), in the middle of what we may call a rosette-tube ; but I know of no other instance in which _ it is prolonged in this way. 16. Mownoporrtta crassatina, Waters. (Pl. VIL. fig. 15.) Monoporella crassatina, Waters, Quart. Journ. Geol. Soc. vol. | xxxvii. p. 270, pl. vii. fig. 8; bid. vol. xxxix. p. 485, and vol. xl. p. 291. ; Having seen a recent specimen from New Zealand, and having Q. J. G.S. No. 169. E ie aed 50 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS a fossil with a very large, much raised oviceil, both broader and longer than the length or width of a zocecium, I now think that I made a mistake in uniting Leprala japonica of Busk with this species, although they are no doubt closely allied. The operculum of the recent specimen from New Zealand is thick, membranous, not chitinous, except at the borders, and has two lateral projections directed towards the basal wall of the zocecium, showing similarity, in this respect, to Membranipora and Cellaria. It is about 0:35 mm. wide. . Loc. Tiving: New Zealand (A. W. W. coll.). Fossil: Mount Gambier, Waurn Ponds, Aldinga and River-Murray Cliffs (Aus- tralia), Napier, Waipukurau and “‘ Whakati” (New Zealand). 17. MonoporEtia pissuncTa, Manz. (PI. VI. fig. 8.) Lepraha disjuncta, Manzoni, Bry. Plioc. Ital. cont. la, Denkschr. Ak. Wissensch. Wien, vol. lix. 1869, p. 5, pl.i. fig. 8, and Bri. del Plioc. di Castrocaro, p. 26, pl. i. fig. 35. ? Lepraha urceolata, Hutton, Manual of New Zealand Moll. 1880, p- 192. ? Lepraha Auingert, Rss. Foss. Bry. CHst. Ung. p. 166, pl. viii. fig. 2. Zoarium adnate. Zocscia subovate, distinct, not very much raised, surface covered with very minute granulations. Jour spines above the oral aperture, which is. large, rounded above, straight below (0:25 mm. wide). This I at first called Monoporella crassatina, W., var. micrograna, but it seems to bo identical with the disjuncta of Manzoni, and this and the Jast species no doubt are related to MW. polita, Norm. Loc. Living: New Zealand? Fossil: Pliocene, Castell-Arquato, Castrocaro (Italy); Napier (New Zealand). , 18. MonopoRELLA WAIPUKURENSIS, sp. nov. (Pl. VI. fig. 11.) Zoarium aduate. Zocecia oblong, distinct, arranged in parallel series. Oral aperture (0°15 mm.) about half or a third of the width of the zowecium, straight below, rounded above, with an umbo below the aperture. Ovicell small, globular, raised; surface of zocecium and ovicell punctured. The figure of Lepralia rubens, Stimpson, looks like this species, and the fossil is no doubt closely allied to Cychcopora prealonga, Hincks ; but from comparison of specimens in my collection they do not seem to be identical. Loc. Napier, Waipukurau cutting, and Trig’s Station. 19. STEGANOPORELLA NEOZELANICA, Busk. Vincularia neozelanica, Busk, Quart. Journ. Micr. Sci. n. s. vol. i. p. 155, pl. xxxiv. fig. 5. Steganoporella neozelanica, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. ix. p. 82, pl. v. fig. 9. It is exceedingly difficult to distinguish S. magnilabris and S. neozelanica without the opercula, and the determination of fossils BRYOZOA FROM NEW ZEALAND. Hi therefore requires gre>+ care. In S. magnilabris the shelf at the a part of the opercular opening is much wider than in S. neo- zelanica, in which it is usually juite rudimentary ; ; the lip is also wider and much raised, forming a support for the base of the oper- culum. The tubular passage is also more distinct in S. magnilabris. None of these characters are very satisfactory, as they are all sub- ject to more or less variation. The fossils from Curdies Creek, Mount Gambier, Bairnsdale, Batesford, and Murray Cliffs (Aus- . tralia) all show the magnilabris characters; but a further exami- nation of the Waipukarau and Petane fossils shows that they are S. neozelanica in the Lepralia-stage. Loc. Living: eral! Zeal Fossil: Waipukurau, Petane, and Napier Cane Ze a P ae ki i, pide, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. viii. n Rapier. New Zealand, corresponds in size with a from ri Zealand. The oral aperture in both is = ae Nap pier. "Living : Curtis Island (H.); New Zealand 4 ey PERFORATA, sp.nov. (PI. VIII. fig. 27.) caused me great difficulty, as there are appar- alian and New-Zealand species, or varieties, most none of the characters alone could the separa- ne first of these two is slightly the larger, but operculum (0-12 mm.), relatively longer from the listal edge, with lateral hinges asin Membranipora, surface is similar in texture; there are two lateral spines. The oyicell is large and not much raised, and the oral aperture, of the ovicelligerous zocecia is larger than that of the non- fertile or On each side a little below the orifice there is a large circular jperforation, and in some specimens many zocecia have a few ete oa pores, usually smaller, round the edge of the cell; the aaller than in the following form, and the mandible opening. uipora stenostoma, Busk (Cat. Mar. Polyzoa, p. 60, the insufficient description has made it impossible s meant, and therefore the name must be dropped en more fully described as M. perforata, MacG. = ovicelligerous zocecium is figured by Busk larger zocecia; but no difference in size is mentioned ; drawn from a specimen covered with an in- large openings on each side have been over- ley are very distinct in the Museum slide. , which I now separate with some doubt and upper half the thickest and the lower composed of > E 2 : n the other hand, has an operculum 0-14 mm. 52 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS two layers; the avicularium is smaller, but the opening on the mandible is larger ; the ovicell is smaller and more concealed. In this also there is 2 similar perforation, and also, in some cases, others round the edge of the cell; but this seems to be rare. The fossils from Napier, -Waipukuran, “ Whakati,” and Trig’s Station agree with this last; and while some specimens may have an avicularium to almost every cell, in others they are seldom found, and in one case they seem to be altogether absent. In many rocecia there is a projecting boss, which seems to be imperforate, replacing the avicularium. These two forms are evidently closely allied to M. coriacea, but differ in not having a knob. - The “ knob” of M. coriacea forms a chamber which communicates with the interior by means of a rosette- plate. (I have already, in a Report to the British Association on the Naples Zoological Station, 1880, pomted out that rosette-plates occur at the base of the spines of Memb. cervicornis.) It is also allied to Micropora lepida, Hincks, to which it 1s very similar i in appearance when there is a row of pores round the edge. ‘he mandible of M. coriacea has a central ridge from ti d 1 same structure is seen in the other two species, _ 22. MEMBRANIPORELLA NITIDA, Johnst., var. There are two fossil specimens from Waipukv ke 1 Ww recent ones from “‘ New Zealand” only in haying iour spines, and this is probably not a very important character. ‘The lower lip is thickened, and this is the case in a recent specimen froma Capri; the ovicell has often more or less of a keel, and has a ridge which cuts off the lower part, and in this respect resembles M. distans, Mac- Gillivray (Descrip. of New or Little-known Polyzoa, pt. 2, pl. i. fig. 5). In the fossils there are no avicularia, whereas in a recent specimen of this variety from New Zealand thera is a large patulate vicarious avicularium, like that figured by Busk for Oribrilina philo- mela, var. adnata. The costs vary from five to eight on a side. We seem now to have various links, recent and fossil, between C. figularis, O. philomela, and Membraniporella nitida, and there i is no hard and fast line between Cribrilina and Membranipor td, Loc. Living: New Zealand. Fossil: Napier, Walp es © 23. CRIBRILINA MONOcEROS, Busk (non Reuss). : Ait Lepralia monoceros, Busk, Brit. Mus. Cat. p. 72, pli x¢ and 6; MacGillivray, Zool. of Victoria, decade iv. p. € figs. 1 and 2; Ridley, Zool. Coll. ‘ Alert, Proc. Zool. p. dl. ies ‘ Cribrilina monoceros, Hincks, Ann. & Mag. N. H. ser. 5, v p. 57, pl. iii. fig. 6, and vol. xiv. p. 279, pl. viii. fig. 5; 0. J. Geol. Soc. vol. xxxviii. p. 507; Busk, ie of ‘Chal Polyzoa, p. 133, pl. xix. fig. 8. é ; In Hie Napier fossil the size of the aperture ns , ea ee eg ee ee ee a a ne BRYOZOA FROM NEW ZEALAND. se specimen from Port. Western there are lateral denticles and a con- traction some distance down the aperture, which may represent the teeth, which are so marked in the Bairnsdale fossil, but have not been found elsewhere. I believe that LZ. monoceros and L. larvalis MacGillivray are entirely different. Loe. Living: Straits of Magellan, 10-20 fath., Tierra del Fuego, 19 fath., Falkland Islands, 4-10 fath.,Cape Horn, 40 fath.(B.); Eliza- beth Island, 6 fath., Sandy Point, 7-10 fath., Tom Bay, 0-30 fath, Cie.) ; Bass’s Straits (Zi); Warrnamboul (MacG.) ; “Challenger : station 163; Port Jackson, 35 fath.; st. 303, 1325 fath.; st. 235, N. Pacific, 3125 fath.; st. 315, 12 fath. Fossil: Bairnsdale (Victoria) in Eschara-form, Napier (N. — adeabe, Petane. 24. CRIBRILINA FIGULARIS, Johnst. Cribrilina figularis, Waters, Quart. Journ. Geol. Soe. vol. xli. p. 293. Specimens from Waipukurau are very distinctly carinate down the centre, and there is a considerable margin of smooth cell; the ovicells are those characteristic of figularis, but I do not find any avicularia. Perhaps this is Lepralia Haueri, Rss. Loe. Living : European Seas, Marion Islands, and Heard Islands. Fossil: Crag; River-Murray Cliffs, Waipukurau. 25. CrirpRinina RADI.TA, Moll, var. EnpLicHeErt, Rss. Lepralia Endlicheri, Reuss, Foss. Polyp. Wien, p. 82, pl. ix. fig. 27, and Foss. Bry. Gist. Ung. Mioc., Denkschr, Ak. Wissensch. Wien, vol. xxxii. p. 171, pl. i. fig. 9. A fossil from Napier Harbour has short, broad, oval zocecia with very solid shell. The ribs are irregular, usually 6 or 7 on a side. The oral aperture is larger (0°15 mm.) than that of typical C. radiata, and below it there is a distinct raised tubular pore surrounded by a border, so that it appears marsupiate. The ovicell is about the width of a zocecium, and, as far as can be judged, this has a radiate structure. The L. Hndlicheri of Reuss has been found in several Miocene localities of Austria and Hungary. 26. Microporerna criiata, Pall. Eschara ciliata, Pall. Elench, p. 38, and for synonyms see Hincks, Brit. Mar. Polyzoa, p. 206. Lepralia calabra, Seguenza, ‘“‘ Formazioni Terziarie,” Accad. Lincei, cclxxvii. p. 201, pl. xv. fig. 6. The fossil from Trig’s Station has a large round suboral pore on a prominent mucro, and the ayicularian opening is nearly round; surface punctured. Oral aperture 0-1 mm. wide, with six spines. This form is the Lepralia pleuropora, Rss. Foss. Bry. Gist. Ung. Mioc. p. 153, pl. iv. fig. 11. The specimens from “ Whakati” and Napier have a smaller round or lunate suboral pore with larger avicularian (vibracular) opening, and the avicularian chamber forms a tube or tunnel with the opening 54 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS directed towards the centre of the zocecium. . This form is the M. calabra of Seguenza. The specimen from Waipukurau has rather smaller zocecia than the others, but the oral aperture of all is about 0-1 mm. wide. Loe. Living: Cosmopolitan. Fossil: Miocene, Austria and Hun- gary; Pliocene, Italy and Sicily, English Crag, Mount Gambier (Australia), Napier, Waipukurau, and Trig’ s Station (New Zealand). 27. MicrororettA Matusn, Aud. Microporela Malusu, Aud., Waters, Q. J. Geol. Soc. vol. xxxix. p. 437. Loc. Living: European seas, 8. America, N. Zealand, Australia. Fossil: English Crag, and Pliocene of Italy, Bird Rock (Victoria), Napier, Petane (N. Zealand), 28. MicroporELia (?) MACROPORA, Stol. Lepralia macropora, Stoliczka, Olig. Bry. von Latdorf, p. 84, plan: fig. 3; Sitz. Ak. Wien, Math.-nat. Cl. Bd. xlv. Abth. i. 1862. Escharipora stellata, Smitt, Floridan Bryozoa, p. 26, pl. vi. figs. 1380-133. Microporella macropora, Waters, Quart. Journ. Geol. Soc. vol. xxxvili. p. 267, pl. vi. fig. 18. Microporella stellata, MacGillivray, “New or Little-known Polyz.” pt. 2, Tr. Roy. Soc. Vict. vol. xix. p. 131, pl. 1. fig. 4. The fossil from Waipukurau has an avicularium at each side of the aperture, and should, as I have before pointed out, perhaps be called var. biarmata on that account; and I have again to repeat that although no suboral pore is known, the general characters are those of Microporella, the genus in which Professor MacGillivray has also placed it. ji Loc. Living: Port Phillip Heads (MacG@.); Port Phillip (W.); Florida (Sm.). Fossil: Miocene, Latdorf (with one avicularium) ; Waipukurau. 99, MicropoRELLA DECORATA, Rss., var. ANGUSTIPORA, Hincks. Microporella diadema, MacG., form angustipord, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 249, pl. viii. fig. 3. MacGillivray and Hincks have made several varieties of M. dia- dema; but it seems to me that they should be called varieties of M. decorata, Rss. In the typical M. decorata the avicularium is directed directly distally, and in the recent forms there is consider- able variation, as, for example, between var. lata and var. lunipuncta, MacG. In a fossil specimen of the typical I. decorata, fom Vigna di Mare, near Reggio, Calabria, the shape of the pectic the same as in var. A pelaia and lunipuncta, and,so far as the state of preservation allows of comparison, the other characters are the same. It seems to me that we should divide this group into I. decorata, Rss., typica ; var. diadema, MacG. ; var. angustipora, Hincks ; var. BRYOZOA FROM NEW ZEALAND. DD lunipuncta, MacG. ; var. longispina, MacG. ; var. lata, MacG.; var. canaliculata, MacG. Loc. Living : New Zealand. Fossil: Waipukurau, Napier, Petane, and Trig’s Station (New Zealand). 30. MicRopoRELLA MAGNrIRosTRIs, MacG. Lepralia magnirostris, MacGillivray, Trans. Roy. Soc. Vict. vol. xix. p. 134, fig. 6. Microporella magnirostris, Waters, Quart. Journ. Geol. Soc. vol. xli. p. 296. Microporella introversa, Waters, Quart. Journ. Geol. Soc. vol. XXxvil. p. 268, pl. ix. figs. 33, 34. Porina magnirostris, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xiv. p. 279. Both specimens from Waipukurau are in the Eschara-stage, and in the one from “ W. cutting” it forms a contorted undulating anastomosing mass. Loe. living: Port Phillip Heads. Fossil: Mt. Gambier, River- Murray Cliffs, Waipukurau and “ Waipukurau cutting.” 31. MucroNELLA MUCRONATA, Smitt. Mucronella mucronata, Waters, Quart. Journ. Geol. Soe. vol. xl. p. 293. Loe. Living: Florida. Fossil: Curdies Creek, Mt. Gambier, Bairnsdale, Muddy Creek, and Murray Cliffs (Australia), Napier (New Zealand). 32. MucroneELia nitmpa, Verrill. For synonyms, see Waters, Quart. Journ. Geol. Soc. vol. xli. p- 293, to which add Smitiia reticulata, var. spathulata, MacGillivray, Trans. Roy. Soc. Victoria, vol. xix. p. 135, pl. iil. fig. 14. Smitira reticulata, MacG., var., Hincks, Ann. & Mag. Nat. Hist. ser. 5, Vol. vill. p. 64. Although MacGillivray describes his variety as with spathulate avicularia, the avicularium figured can scarcely be called spathulate, and in the shape there seems to be great variability. I have speci- mens from Rapallo (N. Italy), and Victoria (Australia), in which the large avicularia are broadly ligulate, while the small avicularia are oval and have rounded ends. In all cases, the avicularium on one side is large, on the other small, and the name inequalis, which I gave to the Neapolitan specimen, calls to mind the most important character. Loc. Living: Vineyard Sound and Long Island Sound (V.); Africa (H.); Victoria Bank, S.E. Brazil, 32 fath. (7tidley); Victoria, Bass’s Straits (Hincks); Naples and Rapallo ,( Waters). Fossil: English Crag (W.); Bairnsdale (Gippsland), River-Murray Cliff (South Australia) ; Waipukurau, Napier, and Tommy Gully (New Zealand). 56 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS 33. MucroneLLa PRastAns, Hincks. Mucronella prostans, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. x. p. 99, pl. vii. fig. I. Mucronella duplicata, Waters, Quart. Journ. Geol. Soc. vol. xxxvii. p- 328, pl. xvi. fig. 54, and vol. xxxviii. p. 266. The fossils from Waipukurau are surrounded with large pores, as in the Curdies-Creek specimen, and some cells have similar avicu- laria, but they do not occur in all. My WM. duplicata was described from a fragment of only a few cells, and although I also referred to a recent specimen sent over by Mr. Hutton as Lepralia variolosa, and gave particulars, it may, perhaps, be best to break the rule concerning priority and adopt Mr. Hincks’s name. This is allied to MW. coccinea, but differs 1 in the larger ovicell, which is not recumbent. Loc. Living: New Zealand. Fossil: Canine Creek (S.W.. Victoria); Mt. Gambier in Vincularia-stage ; Waipukurau, Petane marls. 34. Mucronetta Pracutt, Johnst. This occurs fossil from Napier and probably the other localities ; but in the fossils it is very difficult to always distinguish between this and the following variety, which is common. 35. MucronEeLia Pracutt, var. ocropentTAaTA, Hincks. Mucronella Peachii, var. 8. octodentata, Hincks, Brit. Mar. Polyzoa, | Pusolapls li pies. Mucronella ter es, Hincks, Ann. & Mag. N at. Hist. ser. 5, vol. viii. p. 65, pl. 11. fig. 5. Mucronella spinosissima, Hincks, loc. cit. pl. ii. fig. 2. ? Mucronella ventricosa, var. multispinata, Busk, ‘ Challenger ’ Report on the Polyzoa, p. 160, pl. xxii. fig. 11. ? Mucronella le VIS, MacGillivray, Trans. Roy. Soc. Victoria, vol. xixep. 136, pl. mi: fig. 16. Lepralia arrecta, Rss. Bry. Gist. Ung. Mioe. p. 24, pl. i. fig. 11. This is acommon fossil from Waipukurau. The zoarium is adnate, with distinct, raised, ovate, smooth zocecia; peristome raised all round, with about eight spines on the upper part, and a broad flat denticle in the oral aperture directed downwards (towards the neural wall); this denticle closes about one third of the aperture. Usually a row of pores round the border of the zocecium. Ovicell small, globular, smooth, recumbent. Perhaps this should be called M. Grotriana, Stol. (see Reuss, Fauna Sept. p. 57, pl. vu. fig. 1; Denkschr. Ak. Wissensch. vol. xxv. p. 173, pl. vu. fig. 1), which only differs in the absence of spines. L. Hornesi, Reuss, is also closely allied. Loc. Living: Shetland (A. M. N.); Capri (A. W. W.); Curtis Island (#.); Station 148, and Prince Edward’s Island, 80-120 fath. (B.); New Zealand species sent by Miss Jelly. Fossil: Wai- pukurau, Trig’s Station (Tanner’s Run), and Napier (N. Zealand). i ae BRYOZOA FROM NEW ZEALAND. 57 36. Mucronetta? atvarezrana, d’Orb. (PI. VII. figs. 24, 25.) Escharina alvareziana, @Orb. Voyage dans l Amérique, t. v. p. 14, pl. vi. figs. 1, 4. Lepralia alata, Busk, Cat. Mar. Polyzoa, p. 71, pl. lxxix. fig. 3. Mucronella alvarezi, Jullien, “‘ Bry. Cheil.” Bull, Soc. Zool. 1881, p. o. Two specimens from Waipukurau have subhexagonal zocecia, with radiating grooves on the front and a very prominent umbo in the centre, a small ayicularium or vibraculum on each side about the middle; a row of large pores round the edge of the zocecium situated between the grooves. Above the oral aperture 4-6 spines. Oral aperture about 0-1 mm. wide, rounded on the distal edge, nearly straight below, forming a semicircle; the lower edge is minutely serrated, with three small teeth in the centre; on each side of the aperture a denticle directed inwards. This differs from L. alata, as described by Busk, in the number of spines, and his description leaves us in doubt as to the aperture ; and merely from the fossil it is impossible to be quite sure as to the genus. As Lepralia alata has never been returned to the British Museum, I have been unable to make a direct comparison. Loc. Cape Horn, 40 fath. (B.); Peru (d’0.); Valparaiso (/.). Fossil: Waipukurau, Trig’s Station, and ‘“‘ Whakati.” 37. MucroNELLa TRricuspis, Hincks. Mueronella tricuspis, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. vili. p. 66, pl. ii. fig. 1. Mucronella munita, MacGillivray, Trans. Roy. Soc. Victoria, wol. xix, p. 136, pl. ii. fig. 10. A specimen from Petane has a row of pores round the edge, and the peristome rises less suddenly out of the zocecium than in my recent specimen. There are lateral. acute avicularia, the ovicell is recum- bent, and the fossil most nearly corresponds with MacGillivray’s figure. Loc. Living: Curtis Island (H.); Port Phillip Heads and New Zealand (MacG). Fossil: Petane. 38. MucroneLta tRicuspis, Hincks, var. WAIPUKURENSIS, Nov. CE VELL fic. 30.) There is a worn fossil from Waipukurau, which, upon comparison with M. tricuspis, Hincks, turns out to be of the same size, and cor- responds with it in the screen-like elevation, in both cases enclosing two tubes, as mentioned on page 59. In the, fossil, however, the slender lateral mandibles are wanting; but there have been small and apparently nearly round avicularia near the base of the zocecla. 39. Mucronet~s porosa, Hincks, var. minrma, nov. (Pl. VIII. fig. 31.) A fossil from Petane has the upper part of the zocecium thickened 58 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS and raised, and below this large pores on the surface of the zocecia. There is a raised suboral avicularium directed laterally, and some- times also a small round avicularium at the side of the aperture. Ovicell almost concealed in the zocecium above. ‘The oral aperture is about 0°16 mm., whereas in recent specimens of M. porosa from Port Phillip it is 0°33 mm. 40. Mucronetta (?) Liversiperr, T.-Woods. Eschara Liversidget, 1.-Woods, Some Tert. Australian Polyzoa, Roy. Soc. of N.S: Wo 1376, p. 3, figs. xi), ne. xi A fossil from Waipukurau has the proximal edge of the aperture nearly straight, the distal rounded, and a little distance down the aperture there 1s a semicircular ridge which almost divides it into two parts. This, I believe, is the lower edge of the concealed ovicell, as we sometimes see it in Cellaria. Just below the oral aperture there is a much raised protuberance, and on each side of this a large semicircular pore ; below the pro- tuberance there is a large round pore, below which, again, there is usually a small one, which may be elongate. Loc. Fossil: Mount Gambier ( Woods), Waipukurau. 41. MucronEeLia FIRMATA, sp. nov. (Pl. VII. fig. 20.) Zoarium adnate. Zocecia broadly ovate, distinct, raised, coarsely punctured over the entire surface. Orifice almost semicircular, with a square tooth on the lower margin; peristome forming a broad thickened border round the upper part of the orifice, and thickened at each side near the base. This differs from Phylactella labrosa, B., in having no raised peristome below the mouth. Loc. Fossil: Napier and Waipukurau. 42, SmiIrTra RETICULATA, M acG. A badly-preserved Smittia from Whakati seems to be S. reticulata. 43. Smirtra LAnpsBorovit, Johnst. Lepraha Landsborovii, Johnst. Brit. Zooph. ed. 2, p. 310, pl. liv. nies, Wp Loc. Living: Arctic and British seas, Mediterranean, Australia. Fossil: River Murray Cliffs (Australia); Petane (New Zealand). 44, Smirrra BIINcISA, Waters, var. Bicuspis, Hincks. Mucronella bicuspis, Hincks, Ann. & Mag. Nat. Hist. ser. 5, Vole ae ose P MOG svaiey tie: The fossil from Mount Gambier (Quart. Journ. Geol. Soc. xxxviil. p- 272, pl. vii. fig. 1) has the avicularia more raised and has more large pores; but I have a recent specimen from New Zealand with more pores than Mr. Hincks figured, and with the avicularia more raised. The denticle ranges from being deeply cleft to being expanded and nearly flat at the tip. In the important characters the two are unmistakably allied, BRYOZOA FROM NEW ZEALAND. 59 and it is with some hesitation that I make a variety of the New- Zealand fossil and recent specimens. Loc. Living: New Zealand. Fossil: Waipukurau. 45. Suirrra Naprert, Waters. Smittiia Napreri, Waters, Quart. Journ. Geol. Soc. vol. XXx1x p-. 438, pl. xii. fig. 14. x It has been thought that this was the Mucronella tricuspis of Hincks (Ann. & Mae. N. Hist. ser. 5, vol. viii. p. 66, pl. 111. fig. 1), and at one time I concurred in this ‘view, which was based upon the examination of a specimen which Mr. Hincks himself had named M. tricuspis; but having since found a recent tricuspis from Port Philip, Victoria, I see that they are not identical. The recent S. Napierii has a solid shell, with large pores round the border; the avicularian mucro is directed mostly forwards, that is towards the distal end, and below this there is a narrow bifid denticle. The ovicell is sometimes nearly concealed, and its presence is only revealed by a mucronate elevation, in other cases it is con- siderably raised and globose. The MM. trecuspis, which has also been described as M. munita, MacGillivray (Dese. of New or Little-known Polyzoa, pt. 2, p. 136, pl. i1. fig. 10), has a very curious peristome which rises abruptly from the front of the zocecium and is thick in consequence of being hollow, or rather having a tube on each side of the mucro. This has not been mentioned by Mr. Hincks. Inside the peristome there is no denticle, but the proximal edge of the aperture is a straight plate. My specimen is hyaline. Loc. Living: Port Phillip (Australia). Fossil: Waurn Ponds (Australia); Napier, Waipukurau; Trig’s Station, Tanner’s Run, N.Z. 46. Porina GRanpipora, sp. nov. (Pl. VII. fig. 23.) Although the state of preservation of this fossil from Napier is so unsatisfactory that a full description of it is impossible, yet, if again found, it may, I think, be recognized. The peristome is much raised, hiding the mouth, and there seems to have been a large avicularium on the summit at each side. In the centre of the zoccium there is a large round pore, and from this it would seem to belong to Giganiopora of Ridley. 47. Lepratia Porssonir, Aud. (PI. VIII. fig. BT) B a, Flustra Poisson, Aud., Savigny, Descr. de ’Egypte, pl.'x. fig. 5. Lepralia Poissonii, Hincks, Ann. & Mag. Nat. Hist. ser. 5 vol. vili. p. 63, and vol. xv. p. 256. Lepralia setigera, MacGillivray (non Smitt), Trans. Roy. Soc. Wietomal, vol. xix. p, 133; pl. i.:figs. 2, 3. Lepralia odontostoma, Rss. Bry. Gist. Ung. Mioc. p. 16, pl. iv. fig. 8. Lepralia Kirchenpaueri, var. teres, Hincks, Ann. & Mag. Nat. Piet. cer. J, VOl. Vi. p. 7 /, pl. ix. figs. 7, 7a. This is a very common fossil from Waipukurau and corresponds in ? 60 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS size with recent specimens from New Zealand, in which the front surface is smooth, and the small smooth ovicell has a mucronate ridge down the centre. In recent specimens the spines do not occur in all zocecia nor in all specimens. The most spinous specinten that I have seen is one from Tahiti, in Miss Jelly’s collection. This is nearly related to Lepralia adpressa, and I still adhere to my opinion that LZ. Kirchen- pavert, Heller, is only L. adpressa, in which, as I pointed out and figured in my paper on the Bryozoa from Naples (Ann. & Mag. N. H. ser. 5, vol. i. p. 42, pl. xv. fig. 13), there are sometimes ‘lateral bosses.” The best figure of L. Kirchenpaueri is given by Manzoni (Supp. alla Fauna dei Bry. Medit. p. 8, tav. iii. fig. 3). The characters of the opercula of L. Poisson and L. appressa (figs. 37, 38) enable these to be readily distinguished, although also showing a near relationship. In the fossil some cells have the central mucro very prominent and in others it is entirely absent. Loc. Living: Bass’s Straits, Tahiti and New Zealand (H.); Port Phillip Heads (MacG.). Fossil: Napier and N. Harbour; Waipu- kurau, “ Whakati,” and Petane; Shakespeare Cliff (New Zealand) ; Miocene ; Rauchstallbrunngraben, near Baden. 48, LepraLia RECTILINEATA, Hincks. (PI. VII. fig. 16; Pl. VIII. figs. 34, 35, 36.) Lepraha rectilineata, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xi. p. 110, pl. vii. fig. 5. In a specimen from Waipukurau there is often a small ridge or boss at each side of the aperture, just below which there are two small avicularia, usually near together. Where the aperture is con- tracted there is a curved denticle. directed inwards, and there is a similar one in LZ. Dorhnii, Kirchenpauer (MS.), from Naples. A specimen from Wanganui has large, elongate avicularia above the aperture, whereas there are none in the one from Waipukurau. The ovicell, which is not known in the recent form, is raised, glo- bular, about half as wide as a zocecium. Oral aperture 0:18 millim. at widest part. Loc. Living: New Zealand. Fossil: Waipukurau, Wanganui, Napier. 49, LEPRALIA IMBELLIS, Busk. Hemeschara imbellis, Busk, Crag Polyzoa, p. 78, pl. iv. fig. 6, pl: x. fig. 7. Eschara pertusa, M.-Edwards, “ Obs. sur les Foss. du genre Kschare,” Ann. des Sc. Nat. ser. 2, vol. vi. p. 9, pl. x. fig. 3; 8. Wood, Ann. Nat. Hist. vol. xiii, p. 16; Busk, Crag Polyzoa, p. 65, pl. x. fig. 2. As Lepralia pertusa, Esper, was described before Milne-Kdwards published the present species, the specific name must be changed ; and seeing that Busk found it in the Crag, in both the Eschara- and ~ the Hemeschara-stage, we can take his sécond name. The fossil from near Napier is adnate, and has elongate cells with large punctures over the surface, There are no ovicells on these fossils. Without BRYOZOA FROM NEW ZEALAND. 61 the avicularium this would be Lepralia delicatula, Manzoni (Bry. foss. Ital. 3a cont. p. 11, pl. ii. fig. 17). There are also fossils from Napier, Petane, and Tommy Gully, with shorter cells and large pores arranged in a more or less radiating manner, and in appearance and size much the same as Lepraha striatula, Hincks, which I think cannot be regarded as more than a variety of the present. In a specimen of recent L. striatula sent me by Miss Jelly there are only two or three zocecia with avicularia at the side of the orifice. In none of the fossils do I find any, but it is possible that some cells that are partly broken-down may have had such avicularia. A fossil from Waipu- kurau Gorge has rather short cells with but few pores irregularly arranged. Close allies are Lepraha regularis, Rss., L. corcumornata, Rss., and LZ. megalota, Rss., from the Austrian Miocene, and the living L. Paliasiana and L. pertusa, Esp. Loc. Fossil: Crag, Sudbourne (J/.-Hd.); C. Crag (B.); Zanclean of Calabria (Seguenza). Pliocene: Rametto (Sicily); Gerace, and Tenda del Prado (Calabria) (A. W. W.); Napier (N. Z.), and the short variety from Napier, Petane, Tommy Gully, and Waipukurau. 50, LepRALrIa PERTUSA, Hsper. Cellepora pertusa, Esper, Pflanz. Cellep. p. 149, pl. x. fig. 2. Lepralia pertusa, Busk, B. M. Cat. p. 80, pl. Ixxviil. figs. 1 & 3 (non 2), pl. lxxix. figs. 1, 2; Smitt, Floridan Bry. p. 55; Huincks, Brit. Mar, Polyzoa, p. 305, pl. xlur., figs. 4, 5. Lepraha pertusa, var. rotundata, Waters, Ann. & Mag. Nat. Hist. ser. 5, vol. ii. p. 31. Loc. Living: European seas, Florida, Australia(?); New Zealand (?). Fossil: Muddy Creek ; Waurn Ponds (Austr.) ; Napier (N.Z.). 51. Lepratia RostriezRA, Sm. (Pl. VII. fig. 17.) Escharella rostrigera, Smitt, Floridan Bryozoa, p. 57, pl. x. figs. 203-208. Lepralia rostrigera, Waters, Quart. Journ. Geol. Soc. vol. xh. p. 298. The specimen from Napier is larger than the recent Floridan ex- amples, or the fossil from the River-Murray Cliffs. It is adnate, and the zocecia are divided by raised lines; the surface is punc- tured and granulated; the oral aperture is 0°22 millim., with an avicularium at each side of the aperture. There is a raised border round the aperture. This is allied to Lepralia ingens, Manzoni (Castrocaro, p. 25). Loc. Living: Florida. Fossil: R.-Murray Cliffs (Australia) ; Napier (N. Zeal.). 52, LEPRALIA Lonerpora, MacGillivray. Lepraha longipora, MacGillivray, “ Descript. of New or Little- known Polyzoa,” pt. ii., Trans. Roy. Soc. Vict. vol. xix. p. 185, pl. i. fig. 18. 62 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS Cyclhicopora prelonga, Hincks, Ann. & Mag. Nat. Hist. ser. 5, Vol, xav. Pio, planer 7. The fossil from Waipukurau has the upper part of the zocecium - raised, giving a tubular appearance to the peristome. ‘The surface is granular and has more punctures than are figured by MacGillivray. The ovicell is narrower than a zoecium. In Mucronella canalvfera, Busk, the peristome is much produced and the ovicell is smaller. Loc. Living: Port Phillip Heads (Victoria). Fossil: Waipukurau and Trig’s Station. 53. LerraLia sEMILUNA, Rss., var. simplex, nov. (PI. VII. fig. 19.) Eschara semiluna, Rss. “ Die Foram. Anth. und Bry. des deutschen Septar.” p. 182 (66), pl. vi. fig. 6, Denkschr. k.-k. Akad. Wissensch. Wien, vol. xxv. A fossil from Napier is aduate. The zocecium is suboval, only slightly convex, with rather large pores. Oral aperture elongate, straight below and with the sides straight, curved above. Walls at the side of the aperture thickened, forming a kind of peristome. Above the aperture a nearly concealed ovicell with an oval cribri- form depression in the middle. I am unable to find any suboral avicularia, as described by Reuss, and therefore call it var. semplea. The species is described from Sollingen. 54. LEPRALIA FORAMINIGERA, Hincks. Lepralia foraminigera, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xi. p. 109, pl. vii. fig. 1. The fossil, though there are only the two upper openings, corre- sponds with recent specimens ; the oral aperture, in each case, is about 0°15 millim. in diameter, and the operculum has a character- istic hinge-projection on each side, which Mr. Hincks seems te have overlooked. Loc. Fossil: Waipukurau. Living: New Zealand (#.); Napier (sp. sent by Miss Jelly). 55. LepraLia BisTatTa, sp. nov. (Woodcut, fig. 1.) Zoarium incrusting. Zocecia distinct, convex, surface perforated and mamillated. Oral aperture coarctate, with a small denticle at each side where the contraction takes place. Ovicell small, subim- mersed, about half the width of a zowcium, and the ovicelligerous cells have a very much wider oral aperture than the other zocecia and an extraordinarily thick lower lip. The zocecia and aperture are about the same size as those of LZ. Pallasiana. Loc. Waipukurau Gorge. 56. PoRELLA MaRsuPiIum, MacG. Porella marsupium, Waters, Quart. Journ. Geol. Soc. vol. xxxix. p. 437. 5 Loc. Living: Victoria (MacG.); Bass’s Straits (H.). Fossil: Waurn Ponds (Victoria); Waipukurau (New Zealand). BRYOZOA FROM NEW ZEALAND. 63 57. PoRELLA MARSUPIUM, var. PORIFERA, Hincks. Porella marsupium, MacG., form porifera, Hincks, Ann. & Mag. « Nat. Hist. ser. 5, vol. xiii. p. 24, pl. iv. fig. 4. Loc. Living: Queen Charlotte Island, off British Columbia (#.). Fossil: Waipukurau and Napier (New Zealand). o8. Poretia concinna, Busk. Porella concinna, Waters, Quart. Journ. Geol. Soc. vol. xxxvili. pei Xk: An incrusting fossil from Tommy Gully, Petane, has the avicu- larium much raised on a suboral prominence, and in this respect differs from the European types. The zocecia are divided by raised lines, and the surface has large pores. Loc. Living: European seas; Bass’s Straits. Fossil: Mount Gambier; Tommy Gully (Petane). Fig. 1.—Lepralia bistata, Waters, from Waipukurau, New Zealand. 59. Hippormoa FLAGELLUM, Manz. Hippothoa flagellum, Manz. Bry. Foss. Ital. 4a cont. p. 6, pl. i. fig. 5; Suppl. alla Fauna dei Bry. Medit. la cont. p.3; Bri. del Plioc. antic. di Castrocaro, p. 5, pl. 1. fig. 14; Hincks, Ann. & Mag. Nat. Hist. 1877, vol. xx. p. 218; Brit. Mar. Polyzoa, p. 293, pl. xliv. figs. 5-7; Busk, Chall. Rep. Polyzoa, p. 4, pl. xxxiii. fig. 7. Probably also Terebripora ramosa et wrregularis, d’Orb. Voy. dans PAmer, Merid. Loc. British seas and Medit.; Singapore (H.); Heard Island, 75 fath.; New Zealand. Fossil; Pliocene of Italy and Sicily; Napier. 64 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS 60. ScurzoporeLia crrcinata, MacG. (Pl. VIII. fig. 41.) Lepralia circinata, MacG., Nat. Hist. Victoria, dec. iv. p. 21, [Ok Serie takes JT Schizoporella circinata, Busk, ‘ Challenger’ Rep. of Polyzoa, p. 166, fig. 46; Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 253, Ol, Wat Wore Ie This is a common fossil from Waipukurau, and in size is just the same as recent specimens from Napier. The long spatulate avicu- larium, directed downwards, is usually present; the oral aperture (0:07 millim.) is about half the size of that of S. Cecilu, Aud. Mr. Busk describes in both of these a movable appendage jointed to the operculum; but neither of them is figured correctly by him, as in S. Cecilii the appendage is a broad plate below the operculum, and does not become narrower, as may be seen in the figure given in my paper ‘“‘On the Use of the Opercula” &c. (Proc. Manch. Lit. & Phil. Soc. xvii. 1878, fig. 1), and in S. circinata it becomes broader below; and this appendage separates very readily from the rest of the operculum, so that it is difficult to prepare them out together. In both there is a small notch in the proximal edge of the larger piece of the operculum, into which the appendage fits ; in S. cireinata it is very minute, but in S. Cecili is much more pro- nounced. It does not seem that this appendage is movable, but that an integument is attached both to it and to the proximal edge of the operculum. In neither have I been able to find the minute fasci- culus of muscular fibres at the lower part of the appendage to which Mr. Busk refers, and such a structure would be very inexplicable. Loc. Living: Victoria (MacG.) ; off Inaccessible Island, Tristan, d’Acunha (Chall. Exp.); Napier (Miss J.). Fossil: Waipukurau. 61. ScHIZOPORELLA AURICULATA, Hass. Loc. Living: European and Australian seas. Fossil, Pliocene : Bruccoli (Sicily); Reggio (Calabria); Mount Gambier and Bairns- dale (Australia) ; ee and Tommy Gully Soh mo 62. ScHIZOPORELLA Pane MacG. Schrzopor ella mar EUS, Ridley, Zool. Coll. made a H.LM.S. ‘Alert,’ Proc. Zool. Soc. 1881,'p. 48, pl. vi. fig. 6. Schizoporella Ridleyr, MacGillivray, Trans. Roy. Soc. of Victoria, voleexaxcns wlOl aplepicedtee Le, This is a very small species, with the aperture only 0°6 millim. wide. In the fossil the prominent suboral avicularia cover a large part of the zocecium. This seems to be closely allied to S. awriculata, but is smaller. Mr. Hincks(Ann. & Mag. N. Hist. ser. 5, vol. xiii. p. 25) thinks that this is identical with S.(ELscharina) simplex, d’Orb. ; but Mr. Quelch, who has since examined original specimens of S. 2dleyi, combats this (Ann. & Mag. N. Hist. ser. 5, vol. xiii. p. 215). Iam not quite convinced that this should not be united with S. simplew, dOrb.; but as there is a doubt, it will be best to retain the other name. % - BRYOZOA FROM NEW ZEALAND. 65 Loc. Living: Elizabeth Island, 6 fath. (R.); Victoria (MacG.). Fossil: Waipukurau ; Napier (?). ‘63. ScHIZOPORELLA MARSUPIFERA, Busk. Schizoporella marsupifera, Busk, ‘Challenger’ Report on the Polyzoa, pt. xxx. p. 165, pl. xxii. fig. 14. Schizoporella lineolifera, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xvii. p. 267, pl. ix. fig 10. Loc. Living: Marion Island, 50-75 fath.; Station 167, off New Zealand, 150 fath. (B.); Adriatic (H.); Port Jackson, Sydney (A. W.). Fossil: Waipukurau. 64. ScHIZOPORELLA BIAPERTA, Mich. Eschara biaperta, Mich. Icon. Zooph. p. 330, pl. Ixxix. fig. 3 (see Hincks, Brit. Mar. Poly. p. 255, pl. xl. figs. 7-9); Waters, Ann. & Mag. Nat. Hist. ser. 5, vol. ii. p. 37, pl. x1. figs. L & 2. Loe. Living: European seas, Florida, Madeira, Tartary, Columbia, New Zealand (4. W. W. coll.), Bass’s Straits. Fossil: Doué (Mio- cene); Crag; Pliocene of Italy and Sicily ; Waipukurau. 65. ScHIZOPORELLA CRIBRILIFERA, Hincks. Schizoporella cribrilifera, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 250, pl. viii. fig. 5. — The fossil from the Petane marls is adnate, with the cells irre- gular, as in Cellepora, and the aperture deep down, of the same size and shape as in the recent species, but apparently without avicularia. Loc. Living: New Zealand. Fossil: Petane marls. 66. ScHIZOPORELLA CLAVULA, Manz. Lepralia clavula, Manzoni, Bry. Foss. Ital. cont. 3a, p. 8, pl. i. hes 9, In the fossil from Waipukurau there are six spines above the aperture, and the ovicell is small, erect, somewhat elongate. At one or both sides of the aperture there is a narrow avicularium directed distally, following the border of the aperture, and usually curved. The surface has probably been papillated, but that cannot be made out with certainty. Loc. Fossil: Turin (Miocene); Waipukurau. 67. ScHIZOPORELLA ConseRvaTA, Waters. (Pl. VII. fig. 21.) Schizoporella conservata, Waters, Quart. Journ. Geol. Soc. vol.xxxvil. | p. 340, pl. xvii. fig. 81, and Q. J. G. S. vol. xxxviii. p. 278, pl. vii. fig.’7; Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. x. p. 96, pl. vu. )} fig. 2, and vol. xiv. p. 281. Schizoporella msignis, MacGillivray (non Hincks), Trans. Roy. Soc. Vict. vol. xix. p. 132, pl. ii. fig. 11. I could not for some time decide whether the fossils from Curdies _ Creek and Mount Gambier, the recent forms from near Melbourne, and the fossil from Napier should be united under the same species, Q.J.G.8. No. 169. F — 66 MR. A, W. WATERS ON TERTIARY CHILOSTOMATOUS seeing that while certain important characters show that they are closely allied, in other points there are differences which may be varietal. The oral aperture of the New-Zealand fossil has a narrow sinus and is 0:2 millim. wide, which is larger than in the Australian fossils, but not so large as in the recent examples, in which it is 0°32 millim. wide and has a much larger and rounder sinus. In both the recent specimens and the New-Zealand fossil the ovicell is more concealed than in the fossil first described, and in both there is a row of pores round the flat central part inside the ridge. In fact, in one specimen from Napier the ovicell is quite on a level with the zocecium, and only the ridge and row of pores is visible. These pores are not mentioned by Mr. Hincks in his description, but occur in a recent specimen from Port Western. In the Napier fossil the avicularia are smaller and more raised than in the others, and there is usually only one avicuiarium to a zocecium ; the centre of the zocecium is plain with large pores round it, whereas in the recent examples there is no plain portion, but there is in one a ridge up the centre as first described. The ovicell of the New- Zealand fossilis so much concealed that I am not sure whether there have been radiating lines on its walls. The affinities and differences of these three varieties, separated as they are in time and locality, are very interesting. Loc. Living: Port Philip, Port Phillip Heads, and Port Western (Adelaide). Fossil: Curdies Creek (S.W. Australia), Mount Gambier (S. Australia), and Napier (New Zealand). 68. ScHIZOPORELLA oBLIQUA, (?) MacG. (Woodcut, fig. 2.) Eschara obliqua, MacGillivray, Austr. Polyz., Trans. Roy. Soe. Vict. vol. ix. p. 137 (1868); Zool. Vict. decade v. p. 39, pl. xlviii. fig. 1. An adnate specimen, from Waipukurau Gorge, has zocecia sur- Fig. 2.—Schizoporella obliqua (?), MagG., from Waipukurau, New Zealand. rounded by raised smooth lines, and also frequently a raised line across, or partly across, the zocecium below the aperture, and there BRYOZOA FROM NEW ZEALAND. 67 is sometimes at the side of the sinus a small suboral avicularium, so that the fossil differs in these two particulars from the typical S. obliqua. ‘The sinus is very distinct, and the aperture almost meets above it. 69. ScHIzoPoRELLA crinctTipora, Hincks, var. PERsoNATA, nov. (PI. VIII. fig. 28.) Zoarium adnate. Zocecia ovate, not much raised, divided by slightly raised lines; surface reticulate, with large pores. Oral aperture rounded above, longer than broad, with a distinct sinus on the proximal edge; on each side, below the aperture, on the border of the zocecia, an elongate protuberance; between these, below the aperture, a small rounded avicularium. This differs from the recent forms in having the two lateral bosses. Since describing and figuring the first specimens, I have had another from Waipukurau Gorge, with ovicells, submitted to me. The two lateral bosses, in fully developed ovicelligerous cells, meet in front and form a bridge, as in Smittia jacobensis, S. Landsborovit, var. personata, Microporella polystomella, and Schizoporella polymorpha, B. In the Waipukurau fossils there are no avicularia. Miss Jelly has a specimen of this variety, recent, from New Zealand, growing in a cylindrical shape. Loc. Living: New Zealand. Fossil: Petane marls and Waipu- kurau. 70, ScHIzopoRELLA TUBEROSA, Rss., var. ANGUsTATA, noy. (Pl. VIII. fig. 26.) _ Type: LEschara tuberosa, Rss. Die Foram. Anth. und Bry. des d. Septarienthones, Denkschr. Ak. Wissensch. Wien, vol. xxy. p. 188, Mepe wie, 10) pl. vii. fig. 1. Schizoporella biturrita, Hincks, Aun. & Mag. Nat. Hist. ser. 5, vol. xiv. p. 280,-pl. ix. fig. 8. This occurs fossil from Waipukurau, with a tubular zoarium, in the Hemeschara-stage. Zocecia indistinct, with few large pores. Oral aperture clithridiate, with a large broad triangular avicularium above the aperture on each side directed towards the aperture. - Oral aperture 0°17 millim. wide, 0:21 millim. long. In mode of growth and general characters this resembles a recent Schizoporella tuberosa from the Semaphore, Adelaide, with a large triangular avicularium, which is often much raised, above the aper- | ture on each side, and with a large broad raised ovicell; but in this _ the aperture is much larger and the sinus is broadly emarginate | (see fig. 29). pow ‘the fossil we are reminded of Lunulites incisa, H. (conica, _ MacG.), and Schizoporella biaperta, The typical L. tuberosa also occurs recent in Botany Bay, N.S.W., in the Lepralia-stage. Mr. _ Hincks describes it from Port Phillip Heads in a bilaminate stage. I have not seen any from Australia or New Zealand with the vavicularia imarching, 7.¢. in the personata-stage, as in Busk’s | Gephyrophora polymorpha. | EZ 68 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS 71. Scurzoporenta nyatina, L. (PI. VILLI. figs. 42, 43.) For synonyms, see Hincks, Brit. Mar. Polyzoa, p. 271, and add :— Eschara annularis, Moll, Seerinde, p. 39, fig. 4. I cannot agree with Mr. Busk in uniting this with Chorizopora, which has the proximal edge of the operculum straight, whereas in the ordinary zocecia of S. hyalina there is a wide sinus, and it is only in the fertile cells that the proximal edge is nearly straight (see figs. 42, 43). Mr. Busk identified what we now know as Chorizopora Brongniartui, Aud., with Savigny’s figure of Flustra Brongmartu ; and as this has been generally accepted it would not be advisable now to change the name, though I quite agree with Mr. Busk in doubting whether Savigny’s figure was meant to represent the species. Loc. Living: Cosmopolitan. Fossil: English Crag; Waipukurau and Tommy Gully, Trig’s Station (New Zealand). 72, CELLEPORA ALBIROSTRIS, Sm. Cellepora albirostris, Waters, Quart. Journ. Geol. Soc. vol. xli. p. 304 A specimen from Shakespeare Cliff has a free globular form, about 6 millim. in diameter ; two specimens from Napier are adnate on shell, while another is a large solid branching form. In none is the preservation very satisfactory, and no spines are seen, so that perhaps they should be called var. hastigera, B. ‘The proximal edge of the oral aperture is more curved than in my recent specimens, and in this respect more resembles var. hastigera. Loc. Living: Florida, 25-35 fath.; Sydney (Sm.); Shark Island, 8 fath. (A. W.); Heard Island, 75 fath. (B.); Adelaide (A. W.). Fossil: River Murray (Australia), Napier and Wanganui (New Zealand). 73. CELLEPORA TRIDENTICULATA, Busk. Cellepora tridenticulata, Busk, Journ. Linn. Soe. vol. xv. p. 347; ‘Challenger’ Rep. on Polyzoa, p. 198, pl. xxix. fig. 3, pl. xxxv. fig.17; Waters, Quart. Journ. Geol. Soc. vol. xl. p. 306. The fossil from Waipukurau is adnate, aud shows the attachment — of the two spines very clearly. Loc. Living: Cape York; Adelaide. Fossil: Aldinga; River- Murray Cliffs ; Yorke’s Peninsula (Australia); Waipukurau (New Zealand). . 74. CELLEPORA coRoNoPUs, S. Wood. For synonyms, see Waters, Quart. Journ. Geol. Soe. vol. xli. p. 302. A specimen from Napier occurs in a thick solid branching form. — The minute characters are made out with difficulty. 75. CELLEpora costaTa, MacG. Cellepora costata, MacGillivray, Trans. R. Soc. Vict. vol. ix. 1869, p. 136; Waters, Quart. Journ. Geol. Soc. vol. xli. p. 303. : Cellepora globularis, Bronn, Leth. Geogn. 11. p. 877, pl. xxxv. BRYOZOA FROM NEW ZEALAND. 69 fig. 15, a,6; Reuss, Foss. Polyp. des W. Tertiirbeckens, p. 76 pl. ix. figs. 11-15; Reuss, Foss. Fauna St. von Wieliczka, p. 94; Manzoni, Bri. foss. del Mioc. d’Aust. ed Ungh. p. 51, pl. i. fig. 2. Cellepora retusa, Manzoni, Bri. del plioc. ant. di Castrocaro, p. 35, pl. v. fig. 59. Cellepora retusa, Manz., var. caminata, oe Ann. & Mag. Nat. Hist. ser. 5, vol. iii. p. 194, plans es ds. Cellepora rota, MacGillivray, New or Little-known Polyzoa, pt. viii. p- 11, pl. iu. fig. 6 There are two adnate convex zoaria, fossil, from Napier, about 12 millim. in diameter. In most zocecia the aperture is unarmed, though in a good many there is an avicularium at one side, and these cells exactly correspond with Manzoni’s figure of Cellepora globularis (1 Bri. Mioc. Aust. Ung. p. 51, pl. 1. fig. 2); there are, however, a few zocecia with an oral avicularium at each side. In some specimens of what I may call the typical Cellepora globu- laris, which I collected from the Miocene of Nussdorf, near Vienna, there are nearly always two lateral oral avicularia, but a few zocecia have only one, thus again corresponding with Manzoni’s figure. When these Nussdorf specimens have the two avicularia, the appearance is just the same as in some cells of C. retusa, var. caminata, W., which, however, more frequently has three avicularia. We are thus able to trace the unbroken connexion between the New Zealand fossils, in which the aperture is nearly always unarmed, and the recent Naples form, in which there are usually three very prominent oral avicularia. In all cases the oral aperture is deep down in the peristome. I have a recent specimen from Port Phillip Heads with long branches, seldom with oral avicularia, but when -they occur the mandibles are semicircular. I had not at all recognized the simi- _ larity until I prepared out the opercula, which are characteristic and correspond with the Naples specimens. The apertures are larger than those of the fossils, which measure about 0-08 millim. In this Port-Phillip-Heads species there are large spatulate avicularia. The connexion was thus independently traced up in the fossils by means of the oral avicularia, and in the recent forms by the epercais and other chitinous organs. I have been in doubt as to whether this should be called C. costata or globularis ; but as it is by means of direct comparison of typical specimens rather than by the deseriptions that I have worked up the synonymy, the name costata is retained. ' foc. Living: Wilson Promontory and Queenscliff, Victoria (MacG.); Port Phillip Heads (MacG. ¢ A. W. W.); Glenelg, S. Australia (A. W. W.); Naples(W.). Fossil: Nussdorf C4. W. W.) and numerous other Miocene localities of Austria and Hungary (Reuss Manz.) ; Pliocene of Italy (Manz. d W.); Adelaide, Aus- tralia; Napier, New Zealand. 76. CELLEPORA DECEPTA, sp. nov. (PI. VIII. fig. 33.) There are two unsatisfactorily preserved specimens from Napier. 70 MR. A. W. WATERS ON TERTIARY CHILOSTOMATOUS The lower edge of the aperture is straight, the upper rounded (0:1 millim. wide). ‘There is an avicularium below the oral aperture, and the ayicularian chamber is much raised, so that the appearance of these is sometimes almost like ovicells. The ovicells are usually much concealed. Vicarious avicularia elongate, spatulate, scattered all over the colony. This is related to C. pertusa and C. fossa. CELLEPORA. There is a cylindrical Cellepora from Napier with zocecia irregu- larly placed; the oral aperture subrotundate with a wide sinus. There are numerous avicularia scattered about, some are very large, being the length of three or four zocecia; the mandibular space is acute. It is distinguished from C. yarraensis, Waters, by the shape of the aperture. 77. RHYNCHOPORA LONGIROSTRIS, Hincks. (EI. V Tite. 22>) Rhynchopora longirostris, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. vii. p. 66, pl. iv. figs. 7, 8. Fossil, from Napier, adnate. Zocecia elongate, rising towards the mouth with avery long raised avicularian rostrum. On some zocecia there is a very narrow avicularium attached to the rostrum, with the mandible directed towards the proximal part of the zocecium. The oral aperture is suborbicular, with a wide round sinus. Lthynchopora bispinosa is a most variable species, and when it has been properly worked up will probably have the longest list of synonyms of any Bryozoon, and my first impression was that the fossil belonged to that species. Being unable, however, to find any denticles, and all the cells being equal in size without the peristome rising on either side, I referred the fossil to Schizoporella; but recelving a recent specimen from Port Phillip, Australia, in which the long rostrum was well developed, with a lanceolate avicularium to almost every cell, and a slight elevation of the peristome on each side, the species was again brought back to Ahynchopora. In the recent form I am able to see in one or two zocecia a small denticle, but cannot find one in most. This seems to be allied to Cellepora longirostris, MacG., and Schizoporella cryptostoma, MacG. Loc. Living: Curtis Island (#.); Port Phillip (W.). Fossil: Napier. 78. LUNULITES PETALOIDEs, d’Orb. Lunulites petaloides, d’Orb., Waters, Quart. Journ. Geol. Soc. vol. xxxix. p. 442, pl. xi. fig. 11 a, 6, ¢. There are several specimens from Shakespeare Cliff, Wanganui, and in these the number of vibracula is very variable; they are often placed regularly for two or three rows, and in the rest of the colony scattered irregularly. The aperture is 0-4 millim. wide. I do not see any reason for changing the generic name which has now been used for so long and is so generally recognized, nor is any advantage apparent in the alteration to Lwnaria proposed by BRYOZOA FROM NEW ZEALAND. 71 Mr. Busk, and no one, however eminent, has authority to alter a well-established name. The genus, however, can only be looked upon as provisional, since it is almost entirely based on the mode of growth. This I have already shown to be unsatisfactory, and within the last few weeks have received from New South Wales a recent specimen of Flabellopora elegans, dOrb., which is either Lunulites cancellatus, Busk, or very closely allied to it. This grows in an irregular sub- crescentic form with two layers of zocecia separated by a cellular structure formed of avicularian cells. Loc. Fossil: European Cretaceous, Miocene and Pliocene; Mt. Gambier, Muddy Creek, Bird Rock (Australia); Napier and Wanganui (New Zealand). Besides the species discussed, there are some specimens of etepora from near Napier, and a Oaberea from Waipukurau which may be the C. crassimarginata of Busk. EXPLANATION OF PLATES VI.-VIII. Prats VI. Fig. 1. Membranipora Lacroixii, Aud., var. grandis. From Napier. 2 annulus, Manz. monostachys. From Napier. — Dumerilii, Aud. From Waipukurau. annulus, Manz. From the same specimen as fig. 2. monostachys, From the same specimen asfig. 3. From Napier. nobilis, Rss. From Petane. . Monoporelia disjuncta, Manz. From Napier. . Membranipora annulus, Manz. nobilis, Rss., with cells like ovalis. From Napier. 11. Monoporella waipukurensis, sp. nov. From Waipukurau. 12. Membranipora occultata, sp. nov., fossil. From Napier. 13. —— -—, recent. [14. Cancelled. ] th £2 G0 NID STB G9 Pruate VII. Fig. 15. Monoporella crassatina, Waters. Whakati. 16. Lepralia rectilineata, Hincks. From Waipukurau. rostrigera, Sm. From Napier. 18. Membraniporella nitida, J, From Waipukurau. 19. Lepralia semiluna, yar. simpler, nov. Krom Napier. 20. Mucronella firmata, sp.nov. From Waipukurau. 21. Schizoporella conservata, Waters. Napier. 22. Rhynchopora longirostris, Hincks. From Napier. 23. Porina grandipura, sp.nov. From Napier. 24. Mucronella alvareziana, B., X 25. From Waipukurau. Oo Wibbos Puate VIII. Hig. 26. Schizoporella tuberosa, Rss., var. angustata. From Napier. 27. Micropora variperforata, sp. nov. 28. Schizoporella cinctipora, H., var. personata. From Petane. tuberosa, Rss., recent. From Napier. 30. Mucronella tricuspis, Hincks, var. waipukurensis; front of cells broken down. : 31. Mucronella porosa, H., var. minima. From Petane. 32. Membranipora spinosa, Q. & G. From Napier, 33. Cellepora decepta, sp. nov. From Napier. 72 ON TERTIARY CHILOSTOMATOUS BRYOZOA FROM NEW ZEALAND. . Operculum of Lepralia rectilineata, x 85. . Mandible of Lepralia rectilineata, x 250. —-, x 8D). . Operculum of Lepralia Poissonit, Aud., x 170. adpressa, B., x 170. . Monoporella capensis, var. dentata. From Napier. . Operculum of Membranipora oceultata, sp. nov., X 250. . Operculum of Schizoporella circinata, MacG., x 170. 42 & 43. Opercula of Schizoporella hyalina, L., x 170. = laa A : i. iis iT E E (i=l o> A 6 3 D O WO fa) . i a : : O & = Sp) Z O g | = ae SS) z 2 by WN = fr] a 1 A Waters del. AT. Holl Mintern Bros. imp. | AW. Waters del. A.V Holhck lth . CHILOSTOMAT ZEALAND AW t N NE Pa ey el Mintern Bros. imp is : = @ EA 9) oO 4 a oO 4 : i] mM be fr] A el & SRavesivnetes sa = SES ees VARESE _W. Waters del . AT. Hollick lith. ON THE DRIFTS OF THE VALE OF CLWYD. 73 7. On the Driets of the Vain of Cuwyp and their Rexation to the Caves and Cave-preposits. By T. M°*Kuyny Hvueuns, M.A., F.G.8., Woodwardian Professor of Geology, Cambridge. (Read November 17, 1886.) {Puars IX.] Part I. Introduction. THe questions here involved are many and various, and their consider- ation carries us from one place to another over a very wide area. We cannot safely draw inferences as to the age and origin of any drifts on the borders of a mountain-land without, on the one hand, tracing it up to the source from which it was transported, to see whether we can explain the distribution of the various kinds of material of which it is composed, and, on the other hand, following it as far as possible down over the lowlands, to see whether any succession of deposits or organic remains or evidence as to its former extent can be made to throw light on the conditions of the age in which it was distributed. And, seeing that most caves have been formed and filled during the age of accumulation of the various superficial deposits which we include under the name “drift,” we cannot safely speculate upon the age or origin of the one set of phenomena without con- sidering all the evidence to be derived from the other also. Only in the hilly districts can we find caves at all, and, generally, the more important occur along the outskirts of the high lands, where drifts of various character are apt to be found. The rela- tion of the local drifts to the caves may be of great interest if the exact place and age of those drifts have first been clearly made out. We must first therefore inquire whether it is possible to estab- lish a local succession in the drifts; whether the classification so suggested fits in with the conclusions arrived at in adjoining districts ; whether we can arrive at any connected history of the sequence of events connected with the caves consistent with all the information so gathered. _ . Such are the questions I invite the Society to discuss with reference to a part of North Wales, and I propose to bring forward the evidence I have collected on the subject in the following manner :— A. The Drifts of the Vale of Cloyd. 1. The Arenig Drift. 2. The St. Asaph Drift. 3. The Surface-drift. B. The Caves of the Vale of Clwyd. 1. The Caves. 2. The Cave-deposits. 74 PROF. T. MSKENNY HUGHES ON THE Part II. The Arenig Drift. Any one standing on Arenig or Llyfnant and looking round over the wide expanse of unenclosed moorland, would see at a glance that there, to the west, was a basin in which, under somewhat different conditions, snow might collect to any depth and, compacted into ice, crush its way out towards Bala between the two Arenigs and over the col between Llyfnant and Arenig Mawr, towards the head of Bala lake. There, to the north, was an area on which névées would be formed of the snow that was blown from the crags of Snowdon or Moel Siabod, or many another glorious peak. ‘There is the western sea stretching away beyond the mountains of Harlech, and feeding with moisture the prevalent south-west wind, which keeps the hill-sides for ever damp, and at Blaenau Ffestiniog, as I was informed by Mr. J. H. Williams, throws down yearly 133 inches of rain. The dark southern end of the valley west of Arenig still holds the winter’s snow in its deep shadow far through the summer, and has in consequence the name of Twll-yr-eira, “the hole of the snow.” The long esgair-like ridges running down from it are probably due to the torrents diverted by the snow. Push the mountains up till the moisture that fell should all fall as snow, and the summer’s sun should quite fail to undo the winter’s frost, then the névé must form there, and glacier-ice must flow from the Arenigs and Siabod, from Snowdon and the Carneddau. But we are not left to mere speculation on this point. Over the col and along the east slopes of Llyfnant the glacial striz are still seen running south. They score the rock in long east and west furrows on the rounded shoulders of Arenig Mawr above Milltirgerig. Here and there, in some deep hollow, the remains of the old drift is still seen, and a few scratched stones are found in the fine putty- like felspathic mud worn as the flour of rock in and under the ice from the volcanic ashes that there abound. An example of this drift is seen in the hollow scooped out in the soft Graptolite-bearing shale east of Maengrugog. Also we see whence the boulders came that lie scattered over all the region to the east. Under every precipice of ash and various porphyritic rock there is a talus formed of enormous blocks fallen from the cliffs above. These are mostly well-marked rocks which do not occur again in place among the formations further east. So we can trace this drift by its boulders and fine felspathic mud and small variety of rock up to the valleys of the Dee and Clwyd and far beyond. As we travel east the fragments from the rocks of Arenig and its surrounding district become, of course, less conspicuous compared with the material that the ice has gathered on its way; but all the material has been transported from the west—all from the rocks of Wales—and the striations on the solid rock agree with this. We have already noticed how the grooves ran round the DRIETS OF THE VALE OF CLWYD. i) shoulders of Arenig and pointed to the east. Down into the valley of the Dee between Corwen and Bala; up the steep slope of the Berwyns, as shown by the east and west strize south of Nant- caweddau ; hill after hill bears traces of the passage of the ice in that direction. There must have been some barrier on the north, perhaps the foot of a great ice-sheet from Scotland and the Lakes, so that the Welsh ice crushed its way eastward over hill and dale, ignoring all the highest ranges in its course, down into the Vale of Clwyd, scoring the limestone rocks at Cefn, as seen in‘ the road- cutting behind the stable-yard; then up over the high hills form- ing the northern end of the Clwydian Range, as seen on the top of the hill S.E. of Cwm; across the Hope Mountain and Minera; all the striations running roughly east. No icebergs coming from the west can have grounded behind Cefn. All the evidence points to land-ice as the agent to which we must refer these strie on the solid rock. Along the Clwydian Range huge blocks of the volcanic rocks of Arenig are common. A group is seen by the cottages above the Grove near Bodfari. One enormous boulder lies at the junction of the highest mountain-fences N.W. of Moel Fammau. The more nerthern portion of the drift, derived from the Snowdon rather than the Arenig area, might perhaps be distinguished. There seems to be a difference between the older drift near the north coast and that a little further south; but all comes from the west. The western drift, I think, is seen in the deep sections which the Elwy has cut into the hill-sides above Dolben, and especially at the bend in the river near Dol, where landslips have, however, some- what complicated the section, bringing down some newer drifts which lay upon it higher up the slope. One section gave the following succession :— Fig. 1.—Diagram-Section seen at bend of River Elwy, near Dol. a. Black peaty clay. 6. Sand. ¢. Reddish houlder-clay, resting, with a very irregular line of junction, on d, (Northern or St. Asaph drift.) d. Blue-grey boulder-clay. (Western Drift.) } Masses slipped from above. The newer drifts rest with a very irregular line of junction on an 76 PROF. T. MSKENNY HUGHES ON THE old blue-grey clay with boulders, all from the Welsh rocks to the west. In the Vale of Clwyd the denudation which cut down through the soft or easily undermined strata of the St. Asaph (or Northern) Drift seems to have been often arrested when it reached the stiff tough older clay which we have called the Arenig (or Western) Drift. At the bottom of the cliff beyond Brynelwy, near St. Asaph, where the river had removed the débris from the landslips, a dark blue clay, with boulders of Welsh rocks only, used sometimes to be exposed ; and below the Mount, nearer St. Asaph, the section by the river often shows a similar dark blue boulder-clay overlain irregu- larly by the Marine Sandy Drift (see Section, fig. 3, p. 81). The top of this blue boulder-clay is remanié¢, as in the Colwyn Sections, only that in the Elwy the remanié surface of the old drift is a boulder-clay, while at Colwyn, in the section next to be described, it is a sandy clay. Along the coast in Colwyn Bay a similar dark blue clay full of scratched stones, all of which are from Welsh rocks, is exposed here and there. For instance, at the base of the cliff about 200 yards N.W. of the Bath House at Aberrhyd, where the following section (fig. 2) may be seen :— Fig. 2.—Section seen in Sea-cliff, about 200 yards N.W. of Bath House, Aberrhyd, Colwyn Bay. — (Seale 80 feet to 1 inch). a. Chocolate-red clay, with boulders; some scratches. 6. Sand. c. Yellow laminated sandy clay. d. Blue clay, with many scratched stones. d represents the older clay left by the ice from the great snowy region to the west, which crept downwards from the central gathering-ground, and probably at one time levelled up much of the low-ridged country on the borders of the mountain land. In this no trace of organism has ever been found, except, of course, the fossils in the fragments transported from the older rocks. Changing somewhat locally according to the source from which it is derived, it still has much in common wherever it occurs; but its chief character is this, that in the district under examination it contains only material from Welsh mountains in the west. . This, then, is the oldest drift I know of in the Vale of Clwyd. Call it for local purposes the Arenig Drift, the Western Drift, the Snowdon Drift, the Great Ice Drift, the Older Drift. I deprecate the use of the name “ Boulder-clay” as a technical term for any subdivision of the series. As a descriptive term for any a DRIFTS OF THE VALE OF CLWYD. viv clay with boulders in it, it is required for current language. So the word drift is required for common use in the sense of transported superficial deposits not being volcanic ejectamenta, or rock decom- posed in place, or otherwise included by more strict definition. What seems certain is that, starting in the Arenig district, we find an ancient boulder-clay which contains no fragments from any other district, and no trace of marine action, but follows the tracks of the land-ice away to the east. Whether we are right in referring to the same age and origin certain isolated patches of boulder-clay which occur at the base of all the marine drifts of the north-east of Wales and its borders, is another question ; butit seems to me that there is a strong @ priorz reason for expecting that,such patches should be left here and there, and much evidence that they have been detected in some cases. Besides the sections described above, in which there seems reason to suspect its existence, I may appeal to the publications of many other observers for the occurrence of an older, probably land-ice drift, underlying the marine drifts of the same or adjoining districts. See :— Eyton. Geol. Mag. vol. v. p. 349. Hatt. Geol. Mag. vol. vii. p. 509. MacxintosH. Geol. Mag. vol.ix. p. 15; Quart. Journ. Geol. Soc. vol. xxix. (1873) p. 355, footnote ; vol. xxiii. (1877) p. 738. Metrarp Reape. Quart. Journ. Geol. Soc. vol. xxx. p, 27; vol. xxxix. p. 83; vol. xli. p. 102. De Rance. Proc. Geol. Assoc. vol. iv. p. 221. Srranan. Mem. Geol. Survey, “Geology of the coasts adjoining Rhyl, Abergele, and Colwyn;” Quart. Journ. Geol. Soc. vol. xlii. (1886), pp. 36, 37. This drift cannot be traced continuously to the east or north into the drifts of which the succession, local or general, has been made out. We follow it to the margin of the Cheshire plains ; but where it ended is not so clear. It is everywhere covered by newer deposits over the low ground around the mountain-group from which it came. Mr. Mackintosh has traced what he considers to be the “junction of the Arenig felstone and Eskdale granite dis- persions” along the hills north of Llangollen (Quart. Journ. Geol. Soc. vol. xxxv. 1879, p. 425; vol. xxxvil. 1881, p. 361); and Mr. Searles Wood, chiefly from the evidence collected by Mr. Mackin- tosh, believed that the Arenig ice terminated somewhere along that line (abid. footnote). But whether left by the Arenig ice at an earlier stage of further eastward extension, or derived from its terminal boulder-clays during the period of submergence, there is no doubt that the Arenig rocks occur in the drifts far over central England. Ib is difficult to correlate land-ice drift with marine. Moreover the oldest drifts of Hast Anglia show such a preponderance of northern material that we must suppose that, although we may find there drift of approximately the same age, it belongs to a different ice- stream. How the various parts of such a sheet turn round the hills, cross, overlap, and, in the greater strength of one or other mass, 78 PROF. T. M‘KENNY HUGHES ON THE predominate, may be seen in the beautifully clear view of the Greenland ice given in the Report of the Danish Commission (Meddelelser om Gronland, Heft 1: Copenhagen, 1879). What is a well-established generalization from the examination of the drifts of Kastern England, and bears upon the question now before us, is that there are along the eastern coasts two quite distinct stages—an earlier stage, in which there is more evidence of the direct action of ice, though the deposits are marine like those of later date, and these older drifts contain an Arctic fauna; and a later stage, also marine, resembling the boulder-clay from which it is chiefly derived, but containing few northern forms of life and no evidence of glacial conditions prevailing near. See also :— | | SeaRLES Woop. Quart. Journ. Geol. Soc. vol. xxxvi. 1880, p.516 ; Wl soenbtig Isic), joa UA Gritz, J. ‘The Great Ice Age,’ 1877, pp. 366-3881 ; ‘ Prehistoric Kurope,’ 1881, p. 264. SearLEs Woop. Geol. Mag. dec. 2, vol. v. p. 15. A type of the older drift with Arctic shells, perhaps the marine equivalent of the Arenig drift, may, I think, be seen at Dimlington and Bridlington (see references below, pp. 91, 92). Other examples might be quoted, for instance the Arctic shells found by Brown in the drift at Elie, in Fife, and Errol, in Perth, which, according to Otto Torell, were the same as those now living in front of the Great Glacier at Spitzbergen. (Brown, Rev. Thos., Trans. R. Soc. Edinb. vol. xxiv. p. 627.) In such investigations we are continually met by the great diffi- culty of determining whether a drift 1s not re-made in some way or another, and whether scratched stones and shells may not have been derived from older deposits. (See also, Kinahan, Geol. Mag. dec. 2, vol. 1. ‘“‘Glacialoid or Re-arranged Drift; ” Mellard Reade, Proc. Liverpool Geol. Soc. 1873-74, p. 50, ‘* Tidal Action as a Geological Cause.” we have suggested that the shell-bearing drifts of North Wales represent portions of the sea-bottom thrust forward by the ice-foot and pushed up the flanks of the mountains till, on the melting of the ice, they settled down where they now lie. There seems to be no doubt that such transport of frozen masses uphill and the coming to the surface of matter in glacier-ice does occur. It is analogous to the travelling of boulders across valleys and uphill in glacier-ice, as suggested years ago by Mr. Goodchild in explanation of some of the phenomena of the Lake-district (Geol. Mag. dec. 2, vol. 1. 1874 ; Quart. Journ. Geol. Soc. vol. xxxi. 1875, p. 55), and more generally by Prof. James Geikie (Trans. Geol. Soe. Glasgow, vol. iv. 1874, p. 235, in the ‘Scottish Naturalist,’ and in his paper “ On the Tater crossing of Erratics”). Professor Carvill Lewis refers the shell- bearing deposits of North Wales to the terminal moraine of a mass of land-ice, which carried granite from Scotland and shells and flint from the bed of the Irish Sea (Brit. Assoc. 1886; Geol. Mag. dec. 3, vol. iv. 1887, p. 29). Ithink, perhaps, he would make an exception DRIFTS OF THE VALE OF CLWYD 79 in the case of the lower-level sands such as those of the Vale of Clwyd; but this distinction would be difficult to maintain, and the manner of occurrence of the North-Wales Marine drift along well-defined terraces and with current-bedding and horizontal stratification bearing a definite relation to the physical geography of each district renders this explanation improbable in that case. Besides, the character of the shells is not consistent with the idea of such extreme glacial conditions. The Moel Tryfan deposit, as pointed out by Gwyn Jeffreys (Quart. Journ. Geol. Soc. vol. xxxvi. 1880, p. 355), is not strictly glacial; the fauna has a Norwegian rather than an Arctic facies. So, again, in the case of the marine drifts of the plains of Cheshire and Lancashire, Shone draws attention to the mixture of forms (Quart. Journ. Geol. Soc. vol. xxxiv. 1878), and suggests in expla- nation that the Scandinavian shells in the sands and gravels were derived from an older Boulder-clay (p. 389). Even in the case of the clay-drift, which he thinks was dropped in quiet deep water, he shows that many of the shells must have been carried into it from a sandy shore, and explains this (p. 388) by reference to existing conditions in the estuary of the Dee, where shells with sand in them now get carried out by thin shore-ice into deeper water. In this case it is clear that scratched boulders of granite &c. from the northern land-ice drift must get dropped into the same clayey deposit without having their strie obliterated by being rolled along a shingly shore. Bearing all this in mind, we may now pass on to consider the second division of the drifts of the Vale of Clwyd, a stage in which the deposits were derived in part from the old western drifts above described, and also in part from the boulder-clays which were formed at the end of the ice from the Lake-district, and from the shingle which travelled along the shore from the flint-bearing drifts of other areas. Part III. The St. Asaph Drift. In a paper read before the Chester Society of Natural Science in 1880* I spoke of this as the Clwydian Drift; but as further sub- divisions seem to be already possible, I now use the name St. Asaph Drift as more precise for the stratified beds on which the Cathedral of St. Asaph stands. It might be called the Sea-drift, being the only drift in the vale which we know to have been of marine origin ; or we might speak of it as the Newer Drift, to distinguish it from that older deposit on which it rests irregularly wherever the two are found together, and which, on other evidence, seems to belong to a previous state of things. It might be referred to as the Northern Drift, seeing that in it we find for the first time in the history of the vale fragments of northern origin. * Proc. Chester Soc. Nat. Sci. no. 3 (1884) sty 80 PROF. T M‘KENNY HUGHES ON THE This drift belongs to a period of submergence of which there is other evidence all round the coast of Wales. Hence it is clear that we must divide it into two stages, the deposits of the submergence and those of the emergence. ‘There must have been the waste along the shore of the encroaching sea as the land subsided, and the further down the valleys sunk the safer from further denudation was the débris swept into the deeper parts. ‘There must have been shingly shores and cliffs of boulder-clay of the Arenig Drift, along which landslips took place, and the clay, not always broken up, and the included stones, not always rolled, settled down into the fjords. Round the shore there would be a shingly beach. Then there was the period of emergence, when the land rose to where we have itnow. This was, of course, a time of greater waste and destruction, when the soft, newly-formed beds were lifted up to the level of the wind-waves, or, if they survived the lash of the waves, were raised out of the sea to be acted upon by the summer sun and winter’s frost—by the torrents of rain and the mountain- streams. So we must expect to find along the margin of the valley more sand and gravel, and towards the centre more clay. Now, to examine the sections in the drifts of these stages, I will take them in an order convenient for my purpose of corre- lation, first giving the most typical and clearly made out, and then following them, as suggested by the particular points of variation which I am endeavouring to explain. The river Elwy, when it has once turned north after breaking out of the gorge under the Cefn rocks, generally clings rather to the eastern side of the valley till it joins the Clwyd at Rhydyddaudwr, above Rhuddlan. Down as far as Pontyralltgoch it cuts into stained Carboniferous rocks capped by drift; but soon the solid rock drops out of sight, and the river washes the base of a slippery slope of clay and sand, as seen where it cuts into the steep bank south of Brynelwy. The greater part of the drift seen in this section must be referred to the St. Asaph Drift. The dark-blue boulder-clay sometimes ex- posed at the base near the north end may be, as we have said above (p. 76), the old Arenig Drift. A mass of gravel and sand at the top, which may be the gravel of the shore during emergence, is brought against the red clay by an ancient settlement, the exact amount and direction of which is obscured by subsequent slippings of the face of the cliff; but they both belong to the same set of | deposits, and contain the same remains, In the wood, less than 100 yards to the south, more clay is seen, but the lower part of the section there is obscured by talus and overgrown. The upper sand and gravel is generally grey; the clay is red. Lower down the valley, about 7 mile south of the Palace of St. Asaph, a similar dark-red clay with boulders rests upon sharp red sand, as if derived largely from New Red Sandstone. North of the city, just below the Mount, another section through the St. Asaph drift is | | — DRIFTS OF THE VALE OF CLWYD. 81 generally well exposed, being kept clear of talus by the river, which sweeps the foot of the cliff. (See section, fig. 3.) Here bands of reddish clay occur within the mass, and a red boulder-clay comes on above on the east and south. It is excavated for brickmaking near the railway, a little north ot the station of St. Asaph, and again close to the line where the rail- way crosses the road to Llanerch farm-buildings. This clay seems to thicken tothe south. In the well at Llanerch it was proved to 37 feet 6 inches; while at Maeselwy, in the well, it was found to be d+ feet 10 inches in thickness. The boulders were chiefly at the base. Fig. 3.—Section scen in East Bank of the Elwy below the Mount, St. Asaph. (Scale 80 feet to 1 inch.) a. Surface wash. 6. Alternations of sand, with brown or red clay and loam; varies much from year to year, as the river cuts back the cliff. The middle part is, in general, distinctly banded with even-bedded sand and loam; contains flint, granite, and sea-shells; scratched stones not common. ¢. Blue clay, with many scratched stones; all from Welsh hills (except some stones from 0, which haye got into the top puddled and re-sorted part). On the eastern side of the tongue of drift that parts the Clwyd and the Elwy at St. Asaph, opposite Bronwylfa, on the south, there is a pit showing a similar section in the St. Asaph Drift. Here it is chiefly sand, for which the pit was dug. I have found a few fragmentary sea-shells in it. On the west side also of the valley a similar driftis seen. In the road-cutting opposite Y Roe there is a red clay with shells and boulders. Up the road towards Wigfair Uchaf red sand and clay is excavated here and there. last of Ffynonfair Chapel, just below the bend of the road where it leaves the cliff, and about 3 mile south of Glanllyn, there is a section, the upper part, at least, of which must be referred to the St.Asaph Drift. On top in the read-cutting there is a kind of rain-wash brick-earth ft. 8 in. 2h) CE Loestsei OW Ayal MCS ae eee ea 0 melow tis is areddish boulder-clay ...:...........ccec--ccceccessaccacers 25 0 Ser POM red SAM 2)... coos sinecenevsnerenectenuenee sass 25 O and that on greyish boulder-clay, some stained red ............00+- .?35 0 Q.J.G.S. No. 169. G 82 PROF. T. M‘KENNY HUGHES ON THE It is about 50 feet from this to the bottom of the valley, but the whole section, though changing from year to year, is generally much obscured by slips and talus, especially towards the base, so that I could not make out whether there was rock at the bottom of the section here. It does occur at this level on the other side of the valley. These sections show that we have a variable deposit of gravel and sand and boulder-clay ; and we must now examine in greater detail the constituents and general characters of the beds before we carry our identification further. There seems to be occasionally a surface-gravel, coarse and grey, the result of the winnowing of the St. Asaph Drift during the emergence; but the highest beds, espe- cially along the central part of the valley, generally consist of red boulder-clay, the middle of sands and gravel, with subordinate clay and loam, the bottom of re-sorted boulder-clay or sand resting on the old blue boulder-clay, some of which, at any rate, seems to belong to the more ancient western land-ice drift. Again we notice two distinct groups of included fragments—one consisting entirely of those with which we have become familiar in the Arenig or ice-drift. These are stones from the far-off mountains of Wales, and others which the ice carried from much nearer to where they now lic. Where they have been dropped into clay the scratched stones retain their striz ; where they occur in gravel the scratched stones are rare, and only “the ghosts of scratches” can be seen. : But there is another group of rocks, none of which are scratched. Among these there are many which do not, occur in place in Wales at all. They are in form and surface like the stones found on any beach. . The characteristic rocks are Scotch and Lake-district granite and other igneous rocks and flints. This is true chalk-flint, not chert from Carboniferous rocks, of which there is also some, though rare ; for the principal chert-bearing strata had by this time been removed from the country west of the Vale of Clwyd. These all occur both in the gravels and the upper clays. | In the south part of the section, near Brynelwy, I have found an angular fragment of one of the scratched boulders buried in the clay. This boulder had probably been exposed in some preexisting cliff of boulder-clay, had been shattered by frost or sun or fall, and one bit had dropped unrolled into the depth below, where it was buried in — the mud and preserved from further injury. ‘Thus it retained the | sharp fractured edges,and also one face, which had formed part of the surface of the ice-scratched block. This, I take it, was a stone out of a cliff of the old Arenig ice-drift, which was washed by the sea in the submergence during which the St. Asaph Drift was formed. I have found also in the sand and gravel of the same section clay-balls, containing inside only fragments of Welsh rocks, but with pebbles of the gravel stuck all over the outside, just as I have seen balls of alluvial clay or older boulder-clays rolled on the shore near Prestatyn, or Pensarn, or Colwyn, or near Penrhos in Anglesey, DRIFTS OF THE VALE OF CLWYD. 83 all similarly studded over with pebbles, which have stuck to the moistened, softened outside of the clay-balls as they rolled along. At the time of the formation of the St. Asaph Drift the nearest cliffs of boulder-clay were the masses of western land-ice drift, in which the material was all from the west. All the scratched stones were out of that, and therefore from the west. There were other cliffs of boulder-clay to the north and east, from which northern boulders fell into the sea and drifted along the shore; but the pebbles from them had a long journey by all sorts of conveyances before they reached the Vale of Clwyd and their glacial polish and grooving was all worn away. Of course, the distinction founded upon the occurrence of north- country granites and flint is only local. The north-country land-ice drift contains the granites and other rocks of that country striated, and the older boulder-clays of the east of England are full of flints and other chalk débris. Butin the Vale of Clwyd these occur in the newer marine drifts only. We are not, however, dependent on such evidence alone to prove that these deposits are the result of the action of thesea. Shells are not uncommon. They are generally fragmentary, it is true, just like the shells thrown up in the sand and grayel of the North Welsh coast to-day: but they are, many of them at least, determinable, and I have made a small collection in the river-banks described above, close to St. Asaph. They were originally determined for me by the late Searles Wood, and have been since seen by many good authorities. The list [ have given in column I. in the table, p. 93. So the evidence goes to show that here we have a marine deposit much like that which is being formed in many places on the North Welsh coast at the present time, where banks of drift and clay of various age are being wasted by the waves. There seems to be no necessity for supposing that glacial conditions still prevailed. The forms of life are not Arctic. None of the stones peculiar to the deposit are glaciated ; only those derived from the Welsh hills are striated, and they were probably washed out of the old Arenig ice-drift. If itis asked, how, then, did the boulders from the north get trans- ported to the Vale of Clwyd? I would reply that many may have travelled south on ice when the northern ice abutted against the ice- bound shore of North Wales, but they were not then carried into the Vale of Clwyd. They came there and along the coast with the shore- shingle, as did the flints, which cannot have come from the same country as the granites. We may expect to find, somewhere further north, patches of the old north-country boulder-clay with the granite blocks in it scored by ice. But when they and the flints were tra- velling along the shore as shingle all the original stria were removed. In following the Arenig Drift to the margin of the Cheshire plains we are, of course, tracing it to what may have been always, and must have been for a long time, its extreme limit. Therefore it is not strange to find that there is a larger proportion of northern forms among the shells found in the drifts of Cheshire and Lancashire. 62 84 PROF. T. M‘KENNY HUGHES ON THE Mr. Shone, in his excellent paper (Quart. Journ. Geol. Soc. vol. xxxiv. 1878, p. 384) “On the Glacial Deposits of West Cheshire, together with lists of the Fauna found in the Drift of Cheshire and adjoining Counties,” discusses the difficulty of explaining the mixture of northern and southern forms in the drift. He says (p. 389) that it is “more than probable that the Scandinavian shells of the Middle Sands and Gravels have been derived from the Lower Boulder- clay;” and again, after pointing out that the Upper Boulder-clay rests upon an irregular surface of the Middle Sands and Gravels, he says, ‘what, therefore, more likely than that the southern forms, which are very rare in the Upper Boulder-clay, should have been derived from the Middle Sands?” I would only go alittle further in the same direction, and ask whether the Upper Boulder-clay may not have been derived, together with its Scandinavian shells, from an earlier Boulder-clay, to which they properly belonged. It is shown by Dr. Ricketts that flints occur in the Boulder-clay near Birkenhead (Quart. Journ. Geol. Soc. vol. xli. 1885, p. 597). Mr. Mackintosh, in his paper “ On the Limits of Dispersion of the Krratics of the West of England and Kast of Wales”*, notices the occurrence of flint in the marine deposits of sand and gravel along the eastern borders of Wales; and other writers, many of whom are referred to in the course of this paper, notice the occurrence of flint on Moel Tryfan and in the drift of Lancashire and Cheshire. Aitken records that flint has been found on Holcombe Hill, near Manchester, at an elevation of nearly 1000 feet above the sea (Trans. Geol. Soc. Manchester, vol. vii.). If shore-ice is needed to explain a few exceptional groups of boulders in the drift or on the. hills, that does not involve glacial conditions. I have seen shore-ice in the estuary of the Dee that would float any boulder in the Vale of Clwyd. I have seen at Connahs Quay vessels frozen up in pack-ice 12 feet thick, which broke away in icebergs 50 yards across; and Mr. Alfred Walker has seen the boulders shifted by shore-ice along the same coast. The St. Asaph Drift falls to lower levels as we trace it down the vale to the north. This is probably due chiefly to the original nor- therly slope of the valley in which it was thrown down, but also may have been increased by an unequal movement of elevation, and probably more by the greater denudation near the mouth of the estuary. It occurs in bosses and ridges of red sandy drift near Rhuddlan, the last place where I have seen anything that could be referred to — it being a sand and gravel, with bits of red shale and clay, in a ditch-section 3 mile N.W. of the village, and the upper beds passed through in the Aberkinsy borings. It was probably represented in the Foryd boring also 7. * Quart. Journ. Geol. Soc. vol. xxxv. 1879, p. 446; Trimmer, Proc. Geol. Soe. vol. i. 1831, p. 331 ; Journ. Geol. Soc. Dublin, vol. i. 1838; Mackintosh, Quart. Journ. Geol. Soc. vol. xxxiii. 1877, p. 786; Buckland, Proc. Geol. Soc. vol. iii. 1841, p. 584; ‘ Athenzum,’ 1842; Darwin, Lond., Edinb., & Dubl. Phil. Mag. vol. xxi. 1842. . t “Notes on the Geology of the Vale of Clwyd,” Proc. Chester Soc, Nat. Sci. 1884, p. 36 nee ee nl DRIFTS OF THE VALE OF CLWYD. 85 It is of great importance for our present purpose to inquire what is the character of this drift where it abuts against the rock along the flanks of the hills that bound the vale. The clearest section is that seen in the large limestone-quarry by the road north-west of the old British camp of Parcymeirch, near the village of St. George ; here a well-washed sand and gravel abuts against a steep slope of weathered limestone, as shown in the section, fig. 4. Fig. 4.—Section in Quarry near the Village of St. George. (Scale 30 feet to 1 inch.) HMI PEr Sy HH ND) (tun ofl. A. Mountain Limestone, dip 20° N.N B. Sand and gravel. a C. Reddish boulder-clay, with fragments of sea-shells and scratched stones. D. Talus. In this section it is quite clear that a boulder-clay has filled up an embayed corner in the limestone, and that a sand and gravel swept down the ravine, perhaps into the sea, has caught against the projecting mass, covering the crags and the clay-filled hollows. The process of quarrying has left a thin wall of limestone in front of the gravel and underlying clay-drift, the removal of which in one place gives the appearance of a drift-filled fissure. The red colour of parts of this clay may have been derived from the decom- position of the limestone in which it occurred, and not from the New Red. Further west still, at Colwyn Bay, variable deposits of sand, gravel, and clay occur at various levels up the flanks of the hills. From some of these, at a height of about 120-150 feet above the sea, Mr. Alfred Walker has collected the shells given in column II. of the Table, p. 93. All, except Astarte borealis, are now found upon our coasts (see Jeffreys’s Brit. Conch. vol. ii. p. 320). 86 PROF. T. M“KENNY HUGHES ON THE On the other or eastern side of the Vale of Clwyd, the Talargoch beds abut against the rock at the northern end. Here mining operations have been carried on along the rock-surface, seeking for the lumps of ore that occur in the base of the gravels like the ‘‘ stream tin” in Cornwall. I have found shells, Vellina balthica, in some more clayey beds along the edge of the rock, and, in the deep gravel at the bottom of the workings, bones &c. are said to have been found (Proc. Chester Soc. Nat. Sci. 1884, p. 31) in old times, and in more recent times similar discoveries have been re- orted. : If we are ever able to distinguish between the deposits of the sub- mergence and those of the emergence, the Talargoch gravels will, I suspect, be referred to a late time in the age when the land was coming up again. Now we must bear in mind, First, that the colouring-matter of the New Red Sandstone occurs as a thin pellicle of oxide round the grains, so that when they have been much knocked about, the sand is colourless, and the oxide is carried in the water to stain new beds of finer texture where it can settle down. Secondly, that the New Red does not attain any considerable elevation in the Vale, so that in the submergence 1t was soon below the reach of ordinary denudation. ‘Thus we may expect that many of the drifts derived from it will not be red, because the colour has been washed out, and many drifts of the same, or only slightly dif- ferent age, will be the one red, the other grey, according as any source of the red colour was still in the line of drifting or not. Great masses of grey gravel, near Brynypin, at an elevation of about 500 feet, clearly belong to some part of this age; and when the sea was there it must have left gravel and sand above the more ancient drifts along the Klwy above Pontyrddol. At Brynypin there must have been a tidal swill. All down the east slope of the same hill, on the south side of Bodelwyddan Park, the red-clay drift is seen in the road-cuttings, where boulders of north-country granite are not uncommon, at any rate up to a height of 300 feet. On the eastern flanks of the Clwydian range there are grey gravels high up the hill on the south side of Cwm Nannerch, for instance, which might well belong to this same age; but in the absence of fossils and opportunities for a more careful examination of the constituents, we must suspend our judgment here; for they might be also the gravels at the foot of the great ice, when it had receded just so far. The esgair drift below also, near Bryn Nannerch, requires more evidence before we can feel sure about its age. Three miles and a half to the E.S.E. from here, on the hill-top near where the “‘g” of Caerhug is engraved on the 1-inch map, 34 miles W.S.W. of Northop, some 650 feet above the sea, I have collected sea-shells in the drift. This is an interesting place to find them, for it lies halfway between the shell-bearing beds of Moe Tryfan and the similar deposits near Macclesfield ; while if we trave DRIFTS OF THE VALE OF CLWYD. 87 on in the same line, as far again, we find the Hessle beds con- taining the same fauna. Tn all these beds there are flints somewhat rolled, subangular, as they call them, but never worn to pebbles. Round the south coast to Pembrokeshire we find the same, and the low-lying plateau at St. David’s is covered by a gravel containing flints ; but I have not as yet found traces of shells in it there. This is part of a wide submergence, and of course, when the higher hills were submerged to the extent that I have shown above, the lower regions and the hollow places were all below the sea, the lowest going down first; so, as the climate was growing milder at the close of the age of glaciers, the more southern and temperate forms of life kept following on the receding ice, but the earlier deposits would still contain many of the Arctic types. This may be the reason why, in Mr. Shone’s lists of shells from the drifts in Cheshire and South Lancashire, there are so many more northern species than appear among the shells in the Vale of Clwyd, or Colwyn Bay, or the higher levels of Moel Tryfan, Caerhug, or Macclesfield. Or it may be that the Scandinavian shells are derived from an older boulder-clay. But we must not attach too great importance to this point; for the persistence of a few northern forms does not justify our referring even these beds to the glacial age. Nearer the mountains we have abundant evidence that the deposits we have called the St. Asaph Drift are Postglacial. The striated stones are all such as might be derived from the preexisting Arenig Drift; none of the stones peculiar to the St. Asaph Drift are glaciated. Broken glaciated boulders, balls of Arenig boulder-clay, and, with very few exceptions, shells not of Arctic type occur in this St. Asaph Drift. Deposits of a submergence which succeeded the age of great glaciation have been recognized round the north and east of Wales (Mackintosh, Quart. Journ. Geol. Soc. vol. xxxvii. 1882, p. 184). Along the “Severn Straits” and beyond into the Midland counties, relics of the material washed from the older drift are recognized * (Rev. W. Lister, Q. J. G. S. vol. xviii. 1862; Davies, Proc. Geol. Assoc. vol. iv. 1876, p. 423; Crosskey, Proc. Birmingham Phil. Soc. vol. 11. 1882, p. 209). Marine deposits of this age occur over the plains of Cheshire and Lancashire, as may be seen from the references I give below with the lists of shells (see also:—De Rance, Quart. Journ. Geol. Soc. vol. xxvi. 1871, p. 641, Mem. Geol. Survey, “Superficial Geology of S.W. Lancashire” ; Mackintosh, Chester Soc. Nat. Sci. Feb. 1876, Quart. Journ. Geol. Soc. vol. xxv. 1869, p. 407, vol. xxxili. 1877, p. 732; Ricketts, Proc. Liverpool Geol. Soc. 1876-7, p. 245; Morton and Shrubsole, Proc. Liverpool Geol. Soc. 1875-6 ; Morton, G. H. ib. 1876-7, p. 294, &c., Rep. Brit. Assoc. 1876, p. 110, Geol. * In a paper just published, Mr. Deeley says of the Pleistocene succession in the Trent Basin, ‘‘all the deposits I have described as belonging to the two previous epochs [Older and Middle Pleistocene] were formed during one con™ tinuous period of submergence ” (Q. J. G. S. vol. xlii. 1886, p. 467). 88 PROF. T. MSKENNY HUGHES ON THE Mag. dec. 2, vol. iii. 1876, p. 526; Strahan, Mem. Geol. Survey, 4 Geology ae Chester”; Mellard Reade, Quart. Journ. Geol. Soc. vol. xxxix. 1883, p. 92; Wood, S. V., Geol. Mag. dec. 2, vol. i. 1876, p. 396, footnote). But along the east coast, both north and south of the Wash, marine conditions prevailed long before the ice had receded into the high mountains, and in the shells of the older drift we find the record of this. I have not entered into the discussion of the exact subdivisions or correlation of these beds. JI have referred to some authorities for just the point above stated of an older Glacial and a newer Post- glacial drift. For local purposes a more minute. subdivision is possible and useful, but at present I think we must, for wider cor- relation, adhere to a simpler system, and speak of one great gla- clation ‘succeeded by one great submergence in the west; and in the east, an older marine, probably synchronous with the first or land-ice, and a newer marine, the chronological equivalent of the second or age of submergence in the west. For some suggestive remarks on this subject see Jamieson, ‘“‘ On the Cause of the Depres- sion and Re-elevation of the Land during the Glacial Period,” Geol. Mag. dec. 2, vol. ix. 1882. (See also Dakyns, “ Glacial Deposits north of Bridlington,’ Yorksh. Geol. Polytech. Soc. vol. vii.) In the subjoined table (p. 93) I have given a list of the shells in the St. Asaph Drift and from beds in adjoining districts, which it appears to me belong to about the same age. I have added in the last column for comparison a list of the shells from what is probably a marine deposit of the age of the Arenig land-ice. By reference to the authors quoted it will be seen that in many cases there are subdivisions of importance in the beds which I have included under one head, and that some of the forms which I have recorded may haye been derived from older deposits. It is clear also, from the great difference of elevation, lithological character, and proximity to the mountains, that a somewhat different facies may be expected from deposits which have been laid down at different times in one long age of changing geographical conditions and climate. But nevertheless this point seems to be clearly estab- lished, that the shells enumerated in columns I. to VII. all belong to a somewhat northern temperate group (7. ¢. are Post-Glacial), that under the deposits in which they occur on the west are the land-ice drifts of the Welsh and Lake-country mountains, and that below their equivalents in the east are Old Boulder-clays con- taining, either seattered through the mass or in included masses of contemporaneous sand and clay, a severely Arctic group of shells. These shells are recorded in column VIII. I have omitted all notice of the Echinoidea or Foraminifera, as not being of sufficiently common occurrence to be useful for our present purpose of correlation. The references to the formation, locality, dae age, and the sources of information are as follows :— In column I. are indicated the shells found in the marine sands DRIFTS OF THE VALE OF CLWYD. 89 and gravels of St. Asaph. These were originally determined for me by Searles Wood. The collection is now in the Woodwardian Museum at Cambridge. See also:— Hueurs. “On the Evidence of the Later Movements of Elevation and Depression in the British Isles,” Vict. Inst. or Phil. Soe. Great Brit., March 15, 1880, p. 6. Huenrs. “ Notes on the Geology of the Vale of Clwyd,” Proc. Chester Soc. Nat. Sci. pt. 3, 1884, p. 29. In column II. I have given an unpublished list, kindly placed at my disposal by Mr. A. O. Walker, of shells collected and determined by him from beds about 120-150 feet above the level of the sea in Colwyn Bay. These specimens are in the Grosvenor Museum, Chester. _ In column ITT. I have recorded the shells from Moel Tryfan noticed by :-— Trmmer. Proc. Geol Soc. vol. i. 1831, p. 332; Journ. Geol. Soc. Dublin, vol. i. 1838, pp. 286, 335; Rept. Brit. Assoc. 1838, Trans. Sect. p. 86. Forses. Mem. Geol. Survey, vol. i. 1846, p. 336. DarpisHire. Geol. Mag. vol. 11. 1865, Table, p. 298. Merrarp Reapé. Quart. Journ. Geol. Soc. vol. xxx. 1874, p. 30. Ramsay and Hruerimper. ‘ Physical Geography and Geology of Great Britain,’ 1876. Lyrett. ‘ Antiquity of Man,’ 3rd edition, p. 525. SHone. Quart. Journ. Geol. Soc. vol. xxxiv. p. 383. Gwyn JEFFREYS. Quart. Journ. Geol. Soc. vol. xxxvi. 1880, p.351. Gwyn Jeffreys says that the Moel Tryfan deposit was not strictly a glacial one. The fauna has a Norwegian rather than an Arctic facies. In column IV. I have placed the few shells which have been re- corded from the sands and gravels which occur at intervals along the high ground that rises from the Cheshire plain on the west, from the Vale of Llangollen to the estuary of the Dee, thus forming the eastern boundary of the Vale of Clwyd. I have verified the occurrence of these by finding some myself, but I have not added to Le species recorded by Mr. Mackintosh *. In column V. I have placed together all the recorded Mets from the drifts of the lower levels of Lancashire and Cheshire. Jor the subdivisions of these beds the paper by Mr. Shone (Quart. Journ. Geol. Soc. vol. xxxiv. 1878, p. 383) may be referred to. Mr. Shone thinks that the lower beds of his sections are of considerably greater antiquity, and indicate much more boreal conditions than the over- lying sands and gravels and their covering clay. He suggests that some of the northern shells found in the upper deposits may have been washed out of older beds, and therefore not be a fair index of the climatal conditions of the deposit in which they are found. Mellard Reade considers that the various beds from which he has obtained shells in Lancashire and Cheshire are only local developments of one series. Provisionally he groups them all together under the title of * Quart. Journ. Geol. Soc. vol. xxx. (1874), p. 712, vol. xxxvii. (1881), p. 360. 90 PROF, [. M‘KENNY HUGHES ON THE Low-level Boulder-clays and Sands (Quart. Journ. Geol. Soc. vol. xxx. 1874, p. 36). It does not appear that any one has detected in that area any patches of the drift directly due to the northern land-ice from which so much of the material of all later drifts has been derived. The numerous records of glacial strize on the solid rock lead one to think that there cannot have been much erosion since the ice, whether land-ice or iceberg, passed over it (see Mellard Reade, Proc. Liverpool Geol. Soc. 1872-73, p. 42; Morton, ib. 1876-77, p. 284). But as none of the marine deposits referred to under this head can have been laid down until after the recession of the northern ice, they must belong to an age of less severe climatal conditions, On the other hand, as the ice must have lingered on the high ground of North Lancashire and Wales long after the sea had covered the Cheshire and Lancashire plains, some of these Lancashire and Che- shire drifts may well be nearer the glacial age than the drifts the shells of which are recorded in columns I., II., III., and IV. See also :— Eerrton. Proc. Geol. Soc. vol. ii. 1836, pp. 189, 415. Brynry. Mem. Lit. Phil. Soc. Manchester, vols. vi., x. (1852). Morton. Proc. Geol. Soc. Liverpool, 1870-71, p. 91. Paterson. Proc. Warrington Lit. Phil. Soc. Macxintosa. Quart. Journ. Geol. Soc. vol. xxvii. 1872, p. 388, with Note by Gwyn Jeffreys, p. 391, and note by Searles Wood, p. 392. Mexttarp Reape. Quart. Journ. Geol. Soc. vol. xxx. 1874, pp. 27, 281, vol. xxxix. 1883, p. 83; Proc. Geol. Soc. Liver- pool, 1874-75, p. 35 | Frarineton, quoted by Darpisutre. Quart. Journ. Geol. Soc. vol. xxx. 1874, p. 38. In column VI. will be found a list of the Macclesfield drift-shells. I have not distinguished the older and newer beds of Mr. Darbishire. (Manchester Lit. Phil. Soc. vol. iii. 1865, p. 56; Geol. Mag. vol. ii. 1865, pp. 41, 298.) The shells recorded as having been found by Prestwich in 1862 were from the same drift in an adjoining pit. See also :— SatnterR. ‘ Rambles round Macclesfield.’ MacxintosH. Quart. Journ. Geol. Soc. vol. xxxvil. p. 363. Prant. Geol. Soc. Manchester, Feb. 1865; Geol. Mag. vol. i. — 1865, p. 179. | Metiarp Reape. Mem. Lit. Phil. Soc. Manchester, 1864-65. ; In column VII. I have marked the shells of the Hessle Beds, that — is, practically, the shells collected by Professor Prestwich in the | gravels of Kelsea Hill. The list was revised by Gwyn Jeffreys, and | published in Prestwich’s paper on the Kelsea Hill Beds (Quart. | Journ. Geol. Soc. vol. xvii. 1861, p. 448). See also Clement Reid, © Mem. Geol. Survey, “ Geology of Holderness” (see below, p. 93). These beds, according to Searles Wood, are postglacial, and are f identified with beds which rest on Boulder-clay, and with others which are overlain by still more recent Lacustrine deposits with | Anodonta, Cyclas, Paludina, &c. DRIFTS OF THE VALE OF CLWYD. 91 It is interesting to note the occurrence of Cyrena (Corbicula) fluminalis in these beds, which (though, as pointed out to me by Mr. Clement Reid, it ranges down to the Cromer Forest-bed) is such a common and characteristic fossil in the March Beds and the post- glacial river-terraces of the south-east of England—the valley of the Cam, for instance (cf. Searles Wood, Geol. Mag. vol. ix. 1872). See also :— Puitiies, Quart. Journ. Geol. Soc. vol. xxiv. 1868, p. 250. Woop and Rome. Quart. Journ. Geol.. Soc. vol. xxiv. 1868, p. 146. Hatz. Liverpool Geol. Soc. Dec. 11, 1866. SEaRLES Woop. Geol. Mag. vol. viii. Sept. 1871, p. 406. Lawptuen. Yorkshire Geol. Polytech. Soc. 1879, pp. 8, 9. JuKES-BRownE. Quart. Journ. Geol. Soc. vol. xxxy. 1879, Brod. All the beds from which the fossils were obtained which are recorded in columns I. to VII. must be considered to belong to an age when severely arctic conditions had ceased to prevail, and which therefore may be called Postglacial. In column VIII. I have indicated the shells which have been obtained from the Bridlington Drift. When examining the Dim- lington Section some years ago, in company with Mr. Leonard Lyell, I noticed in the lower part of the cliffs a short lenticular mass of ereenish sand full of shells. It was so small that we worked it out completely. In it we found Vucula Cobboldie perfect and Astarte compressa with valves adherent, and seven other species (see Hughes, * “On the Evidence of the later Movements of Elevation and Depres- sion in the British Isles,” Vict. Inst. or Phil. Soc. Great Britain, March 15, 1880, p. 8). Mr. Lamplugh has since procured shells from similar beds in the same neighbourhood, and has well worked out the equivalent Bridlington Drifts (Brit. Assoc. 1881; Geol. Mag. dec. 2, vol. v. p. 509, vol. vi. p. 393, vol. viii. 1881, p. 535, vol. ix. p. 383; Quart. Journ. Geol. Soc. vol. xl. 1884, p. 312, in which are notes by Gwyn Jeffreys, E. T. Newton, and Dr. Crosskey ; Proc. Geol. Polytech. Soc. Yorkshire, pt. i. 1881, p. 383, pt. 11. 1882, p. 27, pt. iil. p. 240, 1883). See also :— Bran, Wu. “A short account of an interesting deposit of Fossil Shells at Bridlington Quay,’ Loudon’s Mag. Nat. Hist. vol. vil. 1835, p. 355. Youne and Brrp. Geol. Survey Yorksh. Coast, 1822, p. 22. SEDewick. Ann. Phil. 1826, ser. 2, vol. ix. p. 339. Punts. Brit. Assoc. 1835, Trans. Sect. p. 62; Geology of Yorkshire, 1835, p. 40 (in the 3rd edit. p. 274, there is a note by Gwyn Jeffreys). Iyent. Ann. & Mag. Nat. Hist. vol. xii. 1839, p. 324; ‘ Antiquity of Man,’ 1873, p. 266. Forzrs. Mem. Geol. Surv. vol. i. 1846, p. 392. SEARLES Woop. Crag Mollusca, 1847-55. The Bridlington drift was then believed to be about the horizon of the * as 92 PROF. T. MSKENNY HUGHES ON THE Mammaliferous Crag. Quart. Journ. Geol. Soc. vol. xxvi. p. 92, vol. xxxvi. p. 515, vol. xxxviil. p. 681; Geol. Mag. dec. 2, vol. i. p. 246, vol. v. p. 13. SorRBY. Proc. Geol. Polytech. Soc. West Riding, Yorkshire, vol. 111. 1858, p. 559, with the Foraminifera named by Rupert Jones, Gunny. Essay on Geol. Norfolk, White’s Gazetteer, 1863. Tynpatn, KE. Geol. Mag. vol, i. p. 142; Proc. Geol. Soc. Yorksh. vO A735 isis jos We Woopwarp, 8. P. Geol. Mag. vol. i. 1864, pp. 49, 142, 216. CrosskEy. Proc. Birm. Phil. Soc. vol. ii. p. 373. Stupson. Geol. Nat. Hist. Repertory, vol. i. p. 57. Brepwett. Geol. Mag. dec. 2, vol. vy. p. 517. ° Lecxensy. Brit. Assoc. 1864. Gwyn Jurrreys. Brit. Assoc. 1874, p. 83. Daxyns. Geol. Mag. dec. 2, vol. vi. p. 238, vol. x. p. 93; Proc. Geol. Soc. Yorksh. n. s. vol. vii. p. 125. And the collections by Bean and others in the British Museum, and the Leckenby collection in the Woodwardian Museum at Cambridge. In a note at the end of the list drawn up by Gwyn Jeffreys, and published in Phillips’s ‘ Geology of Yorkshire,’ 3rd ed. p. 277, he says, “ All the above species are now living and inhabit the Arctic-and northern seas, Nucula Cobboldie is hitherto known from Japan only.” He further on makes the following important observations on the admixture of littoral and deeper-water shells :—‘* I should be inclined to reject from the list of Bridlington shells the following species, viz. Mytilus edulis, Cardium edule, Littorina littorea, L. rudis, and Purpura lapillus, because they are littoral, and therefore not likely to be-associated with species which belong. to the coralline zone, such as Lhynchonella psittacea, Venus fluctuosa, Dentalium striolatum, Admete viridula, and Columbella Holboll” (=C. rosacea). “ These littoral shells may have come from an overlying or adjacent bed, and become accidentally mixed with the shells from the deposit under consideration.” It is not uncommon to find on any shore among the littoral shells others that have been torn away by currents and tossed up by storms from far below low-water mark. But in that case Gwyn Jeffreys evidently must have thought, from the character of the deposit and other circumstances, that that explana- tion was not sufficient. Mr. Lamplugh has worked this question out, and arrived at the conclusion that some of the shell-bearing beds are transported by the agency of ice from sea-bottoms of various depths further north and mixed up with littoral and even freshwater deposits *. Whether any of them have travelled far or not matters little for our present purpose, as the condition must have been somewhat boreal on a shore thus invaded by ice from arctic regions. I have therefore given the list of the shells as a sample of what we should expect in a true glacial deposit, without noticing the character of bed from which it was derived. For such details I refer to Mr. Lamplugh’s excellent * Geol. Mag. dec. 2, vol. vi. 1879, p. 393. DRIFIS OF THE VALE OF CLWYD. 93 papers, and especially to the recently published Mem. Geol. Survey, “Geology of Holderness,” by Mr. Clement Reid, to whom I am in- debted for the revision of my list and for much kind assistance. The percentages have been changed by Mr. Reid’s work, and the state- ments of Gwyn Jeffreys and others will have to be modified; but the main conclusions to which I would draw attention remain un- altered, viz. that “ with the Bridlington Crag, notwithstanding the close proximity of the deposits, the marine gravels show little con- nexion” (Clement Reid, p. 69). Iam inclined to refer the glacial character of some of the newer marine beds of Kastern Yorkshire to the wasting of old boulder-clay cliffs and the using up of old material, rather than to the recurrence of arctic conditions, and so compare the Arenig land-ice drift of the west with the Bridlington Drift of the east, and the St. Asaph Drift with the shell-bearing sands and gravels of Kelsea and Hessle. There is more doubt respecting the fauna of the glacial beds south of the Humber, Searles Wood’s Mid-glacial, for instance, in conse- quence of the difficulty of discriminating between the contemporaneous shells and those derived from the Crag, which occurs close by. (See a useful review of the literature of this part of the subject by H. B. Woodward, Proc. Geol. Assoc. vol.ix. See also Jukes-Browne.) Table of Distribution of Fossils in Drifts*. I. Rhynchonella psittacea, Chemn....... Anomia ephippium, Linn. ............ tise Weimemedwlis, 002.... .....c+..0ces00+s- % Pecten islandicus, Mill. ............... OmeucmMlarisy7070. -. 0... 5.5.2.0 SemmmeC UMUC OI. 6 Ae aaeediavees- eee Miviulis eodulis, Linn \............0565 * (Modiola) modiolus, Linn....... Crenella decussata, Montagu ......... bb Nucula Cobboldize, Leathes ............ : Sa MNMICIOUS, J7Z7010. .0...+ccccccccccceees| +- Seem CUMS MONTAGU. \.....0..0ccnecees —— ——,, var. inflata, Hane.......... » S[D..c: Donenaeides chin Gos aaa nae ee Leda intermedia, M. Sars ............| === TCT IU (a rr Rem SOY eos cee eecc le teeen| oe == Ie 0) We PVA MOUCCALA 5. ..2c.k. DUGG) Bee a * 2 | EE gS x GL, 2/05 ne ee Say pes Eee * Wyn rernaria, JA. .....-....0-se0c000s- Cam cee Be ee A x SC | 7) oe eke ck be x , var. uddevallensis ......... Eat | * x Saxicava norvegica, Spengl..........--. x % dl (gre rugosa, Linn. (=S. arctica) x | ce eee es x Pholas candida, Linn. .............0008. =e ip oe PRUNE B ly PAT. 0520-0 ccnscanoness- | OO: I We eV Teredo norvegica, Spengl. ............ eer * Dentalium entalis, Linn. ............... a6 | x | x |x x striolatum, Stimpson (=D. abys- LLIUEL) cocci a ie * * ome te SA he * ——tarentinum, Lamk. ..............- waa zp * | Patella yuleata, Finn. ......02....00.00- * x | * Tectura virginea, Mill. ............... | Mepermered, Mill. ............02.06-04: Pha eal ee * Puncturella noachina, Linn. ......... seater ls cercare Fissurella greca, Linn. (=F. reticu- US, tect: 28a re aa x | * | Trochus cinerarius, Jinn................ * | sah pei: * cinereus, Couthouy ............+.- ey Nee * greenlandicus, Chemm............. epeeBoat AN ier * === LL rr ee “of * —— umbilicatus, Mont. .............. | eo | varicosus, Mighels & Adams ... * — ziziphinus, Linn, .............0246. een Lacuna crassior, Mont. ............... Nabe “2 epee ate = divaricata, Fabr. (=L. vincta) | ... | x Cte EAM one Sl pee. 3 Littorina littorea, Linn. ............... * | x Sag Mele Sy ake ey) a obtusata, Linn. (=L. littoralis) * * | * —— globosa, Jeff. ...........cccceceee dea | acd Wik Sal halon BE = CR fx | eee Pa —— squalida, Brod. & Sow. ......... 0] mec by | redi)| 25 Menestho albula, Fadr..................- oe) tae cM ecw a) foxes * Rissoa labiosa, Mont. ................8- ee * —- uly, Pen. (=R. subumbilicata) * a== (La UG Oe * subperforata, Jeff. ..........0.4.. “ * —— Wyville-Thomsoni, Jeffr. ...... me * Homalogyra atomus, Phil. ..... seeaae: * Turritella erosa, Couth. ............... wah eA Sok ig aml bale * ‘terebra, Linn. (=T.communis)} * * x} «x | x * Sealaria communis, Lamk. ............ * * greenlandica, Chemn. ............ * Odostomia conspicua, Alder............ ee * -—imterstincta, Mont. ............... bce * cece De 2 e “ee Pe * Natica affinis, Gmel. (=N. clausa) ... * * ae SS Mamaia: WO0- OCCIUSA ............... Ia Nine eh Naa igenag Folate al | ae: —— Alderi, Forbes (=N. nitida) ... sce | oF da eee wae Wi Se 5: eatena, Da C. (=N. monilifera, | lo eee en a > ieee Pena aie Naeem aE ee = | * — grenlandica, Beck(=N.pusilla)} ... | ... | ... | aegis | x | x er ee 96 PROF, T. MSKENNY HUGHES ON THE TABLE (continued). — ee a a Se ree RE OE ESTO —_—_ 2 oP LA ALEL EV) Vea va yl ete Lee eR Natica islandica, Gmel. (=N. heli- CONG LEY ihe A hp a ee seit teed |e |S 2 pa 3 Montacuti,, Forbes "s238 sticecece.| s24- | eee, fener eo eee ee ee * SOFC ei 77 Blea une ete 8 [ESE PS Pc ie a Amaura sulcosa, Ye) Se a Pe me rem ees (ee fee), An eet * Admete sean, e/a) ampere ee AN rus cae | Tse Pca dere See en ee | ee * Trichotropis borealis, Brod. & Sou..|).. (Oe) ee ee * Aporrhais pes-pelecani, Linn. ......... [perenne hee el let e | =: Purpura lapillus, (2nns Be cisesscesea|/ors [ses | Oe) | meee ee * iBuctmum’ groenlandicum, Chem, 33.) 2.5 | "eo | eee | aoa eee ee | eee ee UNG aint L770 Mn see oe sea hreeen ee (ere lc ae I el lace 2 oes * * Murex erinaceus, Linn. .......2.....0. [eee Orne ee Baril ce). lee Trophon barvicensis, Johnst. .........| eae Neal Wace | clathratus, Linn. (a scalari- foridig) > 52. 2th se Ree ee em Cros Mea eres? 23 ale? * svar, Gunner’ .!.2:220: ses irae horses belie i Wife fe 3 * Ba —— NEVE, ERUNICATA TEL. co. see seks. * te Cran fan cee (iS = * Babrien, Beck (="1. eraticala-) 3.5 {72> | 2244) coe ee eee eee latericeus, Mill. .........+2- Lens) Pras em (RM EOP sce ae ese Ae Fusus antiquus, Lint. ...........0..+ cl tae | | ee Pep lee al eek , var. contrarius (= F’. sinis-| WEOESUS) {Need esa ceoansnaioeces sre ae- (orem Bere percoml aiccein |. = o°| calles * CUES MIC Tree. soe ease pJeiauseneee err Weer pacer (aro Pace | eal asa far —. ,,Var. 6XPansus ....... sacar s orice ene) Dome Rise! 3. el area ae —— despectus, Linn, ........c0c-seccee say Neder Soe Ut See ee ae * * STACWIS WG Ce meas ae aeme tana sane cael eats | eg | paca Se ee eek islandicus, Chemm. ....0..0.00.20+| wen dwcen | Meo Yi oneal eae . —— Kroyeri, WIGIE Ee ae (tae hacia) coke taal Inert fk Se || do ins tata —— Leckenbyi, Sov onde ee perro Varia beret (2-00 ||. sg A etn ote propinguus, Alder ©..........-0: A ees Perreae hatte eras | See || 8. % SAMSISC/ITR cities om eet oe acum wot | aaece | ocean x spitzbergensis, Reeve ............ eee) Ieee [0 Sa. feed fl eee ee * Nassa reticulata, 1in2. ....50.<2...2200- ime PRE Wee Salle ee oh % imerassaba, MU. .a2.ssc5-) ones oe occa. | CTE 562 Ales ee Columbella rosacea, Gould ............ ede WSSSE MCE eee * Pleurotoma bicarinata, Couth......-... % -_——— pEVALD WiOlacea! Saaes.ss tee. 0 ie er * Miecussatas Couths .23205.05-652 205 beatae || Meee eee * elebans SOLU ae sacwenshe ov e-eeeen| es | * exarata iol Mote. oi = tetas ree tee ear eo clo (haha aE oe harpularia, Couth..........0.0s000- saw. Ht Son | Fa 0B | eeoee Reem ee ae et meee —— nebula, Mont. 2.02.c...i5lecccseede | focal S235 ht Set NS deca meee ot tere —— multistriata, Jeffr. ....... Sinerks Ropslenm | hee nN —— pyramidalis, Strom................ ieee * * * | Puta Wont? ieee ee een # % OQ ia?) o =b im en B fa?) rs ag 5 ‘SOAVI) UOJVOTT SVT PUL UZOH JO VOTZVULLO es ‘SOAUD UZOD JO SUITTFUT 5 ‘SOAVD OUNOG UOUUAT TP JO WOTYVLULLOYT a ‘SOAR OUNOG uoUUAT YT FO Sur[FUyT = ‘QAR MOJWOTT SV[G JO Sul[[yuy g OQ nee 8 8 =e ear) iS o 8 4 gg a) = & ‘ase Juang “phan fo aA ‘S][OYS OU * SLOPTMog pozVi.tys ‘d0T JO ony ~ WO POALLop stopTNoq ydooxo ‘poze -14j8 ouou ‘syooa Aajzunod-Yycou pue quIp jo syuourseay ‘ Ss]pos-vos ‘ydusy 4q Jo poauryg pur ‘pug ‘Aero, ‘sTToys-wos { dap ‘00.1004 4Q ‘poosrypey, JO opsurys yuolouy ‘oy ‘suq[op-JUOALOT, ysiquog om} {Ampa pure pmo ayy JO seovttoy, aoddq oy} JO [oar “AMT puv pAMIO OY} JO SooBlAOT, LOMOTT OF JO JOARLID ‘on _,{s]JSolO yy podtounyng ,, Squg ouLtengsyy £ sAelo-vrcnpno1gouay ‘oPSUTYG puv sounp-purg ayn fo sprig ayp fo worgmaafrssn7) ‘480M WOU [TV [Vldoyeur : Avpo-doppnog, ‘ltd Stuety +H qq ydesy 49 VW ‘Spog, YoosavyRy, cs) NIP] DI ‘joan MTA 1ePTO ‘a ) ‘TOABRL) AMTOP TOAVO NT oO IUYZYJOA NT ‘Spogy ULV[Ppnyyy BjALOP ea) ‘spog [AY “V “IVLOWL “UDULNY-INq “ENIUVIL “IVIAQTIV “1ua0aaT — DRIFTS OF THE VALE OF CLWYD. it5 There have been many previous attempts to prove the occurrence of remains of Man in Miocene, Pliocene, and Glacial beds; and before this it has been contended that certain cave-deposits were of preglacial age, because a mass of clay with boulders blocked the mouth—for instance, in the Victoria Cave near Settle, where a large group of animals, such as occur elsewhere along with Man, were found in beds overlapped by boulder-clay which had sealed up the mouth of the cave. It was at one time supposed, from wrong determination of a very obscure fragment, that a fibula of Man himself had been found among them; and well there might have been, for they were paleolithic animals. I organized the committee for the exploration of this cave, and watched the excavation at intervals from its commencement, so I had every opportunity of forming an opinion as to the age and mode of formation of the deposits ; and ‘“ I hold that as the cliff fell back by wet or frost, and limestone fragments fell over the cave-mouth, with them also came masses of clay, which since the glacial times had laid in hollows in the rock above. We dug and found such there, and, more, I observed that the clay lay across the mouth, as though it had thus fallen, and not as if it came direct from glacial ice that pushed its way athwart the crag in which the cave occurs. It seemed to have fallen obliquely from the side where the fissured rock more readily yielded to atmospheric waste, so that it somewhat overlay the part immediately above the cave. On the inside the muddy water which collected after flood, held back by all this clay, filled every crevice and the intervals between the fallen limestone rock, while still outside was the open talus of angular fragments known as screes””*. Mutatis mutandis, we have the same story over again at Ffynnon Beuno. Man followed hard on the receding glaciers; but before the ice filled our valleys there is as yet no evidence that Man had visited the north-western part of Europe or our island, if it was an island then. I do not for a moment deny the possibility or even probability of our some day finding a cave which was formed before the great St.-Asaph-drift submergence, or even before the Great Snowdonian ice rode over the Vale of Clwyd on to the Cheshire plains ; but such caves will be few, and their age hard to prove, for many will have been altogether destroyed by denudation, or will have got swilled out by marine and subaerial currents, and no trace of their first inhabitants will have been left. The question is one of such great interest that we are justified in asking for very clear evidence in each case in which it is stated that human remains of great antiquity have been found in caves. o) Victoria Inst., March 1879. 116 PROF, T. MSKENNY HUGHES ON THE EXPLANATION OF PLATE IX. On Plate IX. are figured, natural size, the principal types of implements found in Pontnewydd Cave. Nos. 1 to 6 are made of a greenish-grey felstone, pro- bably a fine compact ash; no. 7 is of a black cherty material; no. 8 is of flint, weathered a yellowish white. Figs. 1, 1a. A roughly pointed, wedge-shaped, felstone implement on which, at the broader end, a large piece of the original surface of the stone remains, showing that it was manufactured from a drift specimen and not from rock in place. 2,2a. An oval, dcuble wedge-shaped felstone implement, resembling a form I have obtained from the cave of Le Moustier, but more common in the river-drifts. 3, 3a. Another of the same type as No. 1. 4. A subquadrate, flat, felstone instrument, approaching the common Le Moustier form. One end of this specimen is covered with travertine. 5. A quadrate, flat, felstone implement, of a common Le Moustier type. The corners appear to have been used rather than the edges. One part of this specimen shows the original surface of a drift stone. 6. A rough felstone scraper; the side not shown in the figure is nearl flat. 7,7 a. A flake of black cherty rock, might be a Carboniferous chert. 8, 8a. A curved scraper-flake of flint, showing the bulb of percussion and weathered to a yellowish-white colour. Discussion. Dr. Hicks said he was entirely unbiassed when he commenced his explorations in the caverns referred to, and would gladly have agreed with Prof. Hughes’s views concerning the caverns in the Vale of Clwyd if that had been possible. He had, however, found that all the facts were entirely opposed to the views advocated by Prof. Hughes, and consequently he was unwillingly compelled to dis- agree with the conclusions arrived at by him. The facts were per- fectly clear and had been accepted by every one who had visited the caverns, except by Prof. Hughes. The latter did not see the section at the Cae Gwyn cave until it was almost entirely closed up ; and he had also confounded the mixed material placed against the fence by the men in the earlier explorations, as was evident from the dia- grams exhibited, with the undisturbed drift, and had based some of his arguments on this mistake and on an ice-scratched boulder on which there was the clearest evidence of its having been recently struck by a workman’s pick. ‘The fence-argument was valueless in any case, as it could only affect the surface-deposits and not those shown by the speaker to block up the entrance at a depth of 20 feet. | The Arenig Drift is not necessarily the oldest, in places it may even be the newest, and it 1s known from well-sinkings to be underlain by sands and gravels like those at Talargoch, in which bones of animals similar to those found in the caverns were discovered. The speaker cited evidence from numerous areas to prove that the oldest drift contained northern erratics, and said that no hard-and-fast lines bese Ra ee Quart.Jdourn. Geol. Soc. Vol. XLIE Pl. . JNTNEWYDD CAVE DRIFTS OF THE VALE OF CLWYD. aeZ. could be made out in the drift of thisarea. Prof. Hughes’s Clwydian or St. Asaph Drift must certainly be considered the newest, as it is mainly remanié. It is situated at a low level between the im- portant rivers Elwy and Clwyd. The high-level drift at Cae Gwyn is a true undisturbed glacial deposit full of ice-scratched boulders, and may be correlated with the deposits mentioned by Mr. Strahan, in his Geological Survey Memoir, as occurring at so many points at a high level in this area. The paleontological evidence shows that the caverns contained a large proportion of the animals found in the Norfolk Forest-bed, which Prof. Hughes admits to be pre- glacial. The absence of other forms would only show that they had probably not migrated into this area, hence this cannot be relied upon as evidence of difference in age. Dr. Hicks was perfectly convinced by the evidence found during the explorations that the caverns of Ffynnon Beuno and Cae Gwyn (the other caverns referred to by Prof. Hughes are nearer the great rivers and at a much lower level, therefore the evidence ob- tained from them is of much less value) must have been occupied by man and the animals before the climax of the ice age. Also that the thick stalagmite was formed during the ice age, that this was broken up by marine action during the submergence, and that the caverns were afterwards completely covered over by materials deposited from floating ice. The mammalian remains and the im- plements, he therefore maintained, must be considered as of pre- glacial age. | Dr. J. Evans spoke on the difficulty of reconciling the views of the two geologists who had spoken ; perhaps both were right in part. He pointed out that a valley must have been cut when the upper end of the Cae Gwyn cavern was opened. In a case in Norfolk of sup- posed preglacial implements, the Boulder-clay beneath which they were found proved to be a remanié deposit. If the cave were preglacial, either the glacial age in Wales was distinct from that in the east of England, or Man went away and returned again. The implement from Cae Gwyn resembles those of the upper deposits of Kent’s Cavern. Now some of the imple- ments in the east of England are made of stones brought into the district by ice of the glacial period. We have also evidence that Plas Newydd cave is postglacial. It is improbable that similar implements are preglacial in Wales and postglacial in the south of England. Prof. Borp Dawxrys said that he had examined much of the drifts of Wales and Lancashire, and doubted if those of the Vale of Clwyd could be distinguished from each other as clearly as Prof. Hughes contended. The interest attaching to the cave depends on the light which it throws on the relation of Palxolithic man to the Glacial period.” After examining the fresh section he felt obliged to accept Dr. Hicks’s evidence. The drift above the place where the implement was found was, in his opinion, not remanié, but in situ. The fact that Paleolithic implements occurred in Postglacial 118 PROF. T. MSKENNY HUGHES ON THE deposits in other caves in the neighbourhood did not prove that they are of Postglacial age in this cavern, because there is evidence at Crayford, in Kent, that the river-drift man was Preglacial in the valley of the Thames. Paleolithic implements are found over a wide area in the Old World—in the south of Europe and north of Africa, in Egypt, Palestine, and in India; and their distribution can only be accounted for by the river-drift man having lived for a long series of ages on the earth, long enough, indeed, to be pre- as well as postglacial. With regard to the Mammalia found in the caves of the Vale of Clwyd, nearly all were living in the eastern counties in the pre- glacial age. There is clear proof (1) that the Pleistocene Mammalia invaded Europe in the preglacial age; (2) that they were driven away from the British area by the results of the lowering of the temperature and of the depression of the land; and (3) that they returned and occupied the British area after the retreat of the ice and the re-elevation of the land. They therefore afford no evidence as to the relation of the deposit in which they are found to the Glacial erlod. ; Mr. Drew asked Dr. Hicks at what depth (behind the fence) did the solid rock occur beneath the place where there was now material tipped by the workmen. Dr. Hicxs, in reply to Mr. Drew, said that the shaft exposing the drift-section was at the furthest end of the cavern from the old fence. 7 Prof. Carvirt Lewis regretted not having seen the cave itself, though he had examined the glacial deposits of the neighbourhood and of North Wales generally. He was glad to hear that the views of the speakers this evening were in favour of a simplification of glacial phenomena. From a study of glacial deposits in many parts of Great Britain and Ireland, he had been led to believe that there had been only one advance of the ice and one retreat, one slight elevation and one slight submergence, and that the submer- gence in the non-glaciated area was contemporaneous with the maximum extension of the ice in the glaciated area. There were three main areas of local glacial dispersion in Wales, the glaciers from each of these being defined by terminal moraines. But there was also satisfactory evidence that an ice-lobe coming from Scotland and filling the Irish Sea had impinged upon the extreme northern border of Wales, and passing over Anglesey and along the west side of the Snowdonian mountains on the one side, and into Cheshire and along the east of the mountains on the other side, had pushed its — terminal moraine against the highlands and in the teeth of the | opposing local glaciers. The latter were both earlier and later than | the northern ice-lobe, and the two drifts were therefore often com- | mingled. The line dividing the northern ice-lobe from the Snow- | donian glaciers was close to the cave under discussion, and the | massive deposits near St. Asaph were probably washed out of the common terminal moraine. The undoubted marine deposits, full of DRIFTS OF THE VALE OF CLWYD. 119 shells, which cover the lowlands of Lancashire up to 150 feet above the sea, also extended up the Vale of Clwyd to the same level; but much of the stratified material in this valley was remanic. Tor- rential freshwater action operating during the melting of the ice is an important factor not to be omitted in studying valley-gravel. Many terrace-deposits supposed to be marine are of freshwater origin and of late glacial age. The PREsiDENT insisted on the importance of carefully weighing the evidence adduced by the Author, seeing to what an enormous extent it was proposed to carry back the date of Man’s appearance on the earth. All those who had visited the open section seem to have regarded Dr. Hicks’s views as, at all events, tenable. Prof. Hueurs explained that the old hedge to which he referred was that shown in the sketch and photographs which he exhibited (it was about 16 feet from the opening in the drift above the upper entrance), and that no material from the cave had been thrown by the workmen over the part opposite the upper entrance. The scratched boulder produced, with the marks of agricultural imple- ments, was one of many out of the drift dug from before the mouth of the cave, and was the one given him by Mr. Luxmoore as a typical specimen of the boulders in the drift. Pontnewydd and Plas Heaton caves could hardly be said by any one acquainted with the district to be at a low level near the great rivers. He would refer to his paper for the evidence in favour of his classification of the drifts, merely pointing out the difficulty of accepting Dr. Hicks’s correction that the Arenig Drift is not necessarily the oldest, though he allows that the St. Asaph Drift must certainly be the newest. He did not understand Prof. Dawkins’s suggestion that Man could have lived through many glacial phases, if he was speaking of the district under consideration. When the Arenig ice covered every- thing, Man cannot have been there. He was not discussing the question whether Man may have been in existence anywhere on the earth while glacial conditions prevailed in Wales, but only whether there was evidence that the cave-deposits of the Vale of Clwyd were preglacial or a little later or much later. He had shown that, according to the best authorities, there was an earlier and a later Pleistocene group of mammals, and had pointed out that the animals in the Ffynnon Beuno caves belonged to the newer. In reply to the President’s remark, he regretted that Dr. Hicks should, after his attention had been more than once called to the imaccuracy of the statement, have again endeavoured to throw dis- credit upon his evidence on the ground that he had not had oppor- tunities of examining the sections. Dr. Hicks had no means of knowing how often he had visited the locality, but had had the means of knowing from a printed report that he (Professor Hughes) had examined the caves, and proposed to explore them about a year before Dr. Hicks is supposed to have discovered them. Professor Hughes’s home was close by ; he had frequently visited the caves, and had on several occasions examined the drift that abutted against 120 ON THE DRIFTS OF THE VALE OF CLWYD: the rock in the section referred to by Dr. Hicks from the bared limestone at the base to the surface. He could assure the President that he had not brought the matter before the Society without taking pains to make himself thoroughly acquainted with the facts of the case. He was glad to have the concurrence of Prof. Carvill Lewis in the views he had put forward with regard to the sequence of events in Glacial times in Wales. ON THE DENTITION AND AFFINITIES OF PTYCHODUS. TOF 8. On the Dentition and Arrinities of the SetacHian GENUS Prycuonus, Agassiz. By A. Smita Woopwarp, Ksq., F.G.S., of the British Museum (Natural History). (Read December 15, 1886. [Prats X.] Notwitustanpine the abundance of the well-known teeth of Piy- chodus in the Chalk of many localities, and the long list of specific forms that have already been recognized, very little information has hitherto been published in regard to the precise affinities of the fish to which they originally appertained. So rarely, indeed, are any of the teeth found associated in natural sequence, that it has been necessary to await the results of many years’ patient collecting before being able to pronounce a decided opinion; but materials are now forthcoming for at least one further step in the determination of their relationships, and I therefore venture to offer to the Geolo- gical Society some account of the accumulated evidence. Since these interesting fossils first became the subject of scientific study, it has been almost the universal custom, as is well known, to refer the genus to the somewhat comprehensive “ family ” of Ces- traciontide. An early determination of Mantell*, it is true, resulted in the suggestion that they formed the dental armature of fishes allied to the Teleostean Diodons; but the elaborate researches of Agassiz’, supported by Owen’s simultaneous investigation of their microscopical structure t, have always been cited as ample proof of the affinity of their original possessor with the Cestraciont Sharks ; and the deeply rooted tendency among paleontologists to refer every isolated crushing-tooth to the same extraordinary group has also contributed to the adoption of this arrangement without serious question. But the original observations from which the inferences as to the systematic position of Ptychodus were deduced are obviously of a very uncertain and inconclusive character. In the absence of any but scattered remains Agassiz was compelled to make use of sug- gestive appearances and probabilities rather than well-ascertained facts; and in framing his conclusions he particularly emphasized at least two of these leading points. In the first place, certain groups of teeth seemed to be so arranged that the smaller and more prehensile examples occupied an anterior position, while the more truly grinding-teeth were scattered posteriorly, thus indicating a disposition analogous to that of the living Cestracion; while, secondly, there were good reasons for suspecting that a number of * G. A. Mantell, ‘ Fossils of the South Downs,’ 1822, p. 231. + L. Agassiz, ‘Recherches sur les Poissons Fossiles,’ vol. iii. pp. 56-59, 150-158, 162. t R. Owen, “On the Structure of Teeth,” Brit. Assoc. Rep. 1838, Trans. Sect. p. 140 ; and ‘ Odontography,’ pp. 57-59, pls. xviii., xix. Q.J.G.8. No. 170. | K £22 MR. A. S. WOODWARD ON THE DENTITION curious “ Ichthyoderulites ” also armed the dorsal fins of the same fish. Owen’s iurther evidence in a similar direction consisted in the remarkable resemblance between the medullary tubes traversing the dentine of the teeth and those to be observed in the teeth of Ces- tracion and Acrodus ; aud in this particular it became obvious that there was a marked divergence from the dentinal structure of Rhynchobatus (Rhina)*, with which the peculiarities of mere external form suggested comparison. The latter superficial resemblance has frequently been noted by subsequent writers +, and Dixon has even remarked+ upon the possibility of the genus Rhynchobatus affording some clue to the arrangement of the fossil teeth in the jaws. But until eleven years ago the three fundamental arguments of Agassiz and Owen remained unshaken, and it is only within this later period that comparatively satisfactory materials for study have been forthcoming. Professor EK. D. Cope was the first, in 1875 §, to show that the supposed dorsal spines of Ptychodus were really the paired fins of Teleostean fishes, having discovered much more complete specimens in the Cretaceous beds of the Western Territory of Kansas. And last year, in the pages of ‘Science Gossip’ |!, | was able to demonstrate briefly that the fossils upon which Agassiz based his conclusions as to the arrangement of the dental armature were likewise misleading, and that there was not the slightest agreement with the Cestraciont plan. As regards microscopical structure, it seems possible to draw con- clusions from Owen’s observed facts somewhat different from the original inferences still generally accepted. And it is with a dis- cussion of the two latter questions, especially the first named, that the present communication is particularly concerned. In the prosecution of such an inquiry the fossils in the National Collection afford several important fragments of evidence, and of these it is proposed to offer some detailed descriptions. But the most beautiful and instructive specimen that I have the honour of bringing before the notice of the Society forms one of the fine series of Cretaceous fossils in the Brighton Museum, collected by Henry Willett, Esq., F.G.S. To the latter gentleman I owe my best thanks for the opportunity of studying it in London and of utilizing it in the present investigation; and I have also to acknowledge much kind help from Edward Crane, Esq., F.G.S., Chairman of the Brighton Museum Committee, who first pointed ‘out to me the fossil last spring. * R. Owen, ‘ Odontography, pp. 44-46, pl. xxiv. | + ¢.g. Pictet (‘ Paléontologie,’ 2nd edit. 1854, vol. ii. p. 265) and Quenstedt (‘ Handb. der Petrefaktenkunde,’ Ist edit. 1852, ‘P- 181). { F. Dixon, ‘ Geology and Fossils of Sussex, 1850, p. 861; 2nd edit., 1878, D. 390. : § E. D. Cope, “ Vertebrata of the Cretaceous Formations of the West” (U. S. Geol. Surv. Terr., 1875), pp. 244 a-r. || Smith Woodward, “Chapters on Fossil Sharks and Rays.—IV.,” ‘Science Gossip,’ vol. xxi. 1885, p. 109. AND AFFINITIES OF PTYCHODUS, 23 _ Descriptions of Specimens. The detached teeth of Ptychodus are so familiar and have been so frequently figured, that nothing remains to be added to the pub- lished descriptions of their general form. But it will be convenient to anticipate slightly by referring to their original relations in the jaw. ach tooth was so placed that the large characteristic ridges and furrows had a transverse direction, while the borders parallel to these were completely anterior and posterior. Judging from the analogy of several recent Selachians to which the genus is most nearly allied, the somewhat excavated and abrupt boundary of the crown was posterior, while the more gently sloping and overhanging border formed the front; this is the interpretation adopted here, and in all our figures the anterior border is directed downwards. On examining the associated groups of teeth, it at once becomes evident that they were arranged in the mouth on two distinct, but yet closely similar plans. The first type, of which I have already published a sufficiently accurate diagrammatic sketch (loc. cit.), is © admirably elucidated by the fossils in the British Museum; and the second is equally well shown in Mr. Willett’s specimen, which, moreover, demonstrates that the two arrangements were opposed to each other in the dentition of the same individual. I. An interesting forerunner of the fossils revealing the first of these plans is a small example of P. decurrens, figured many years ago in Dixon’s ‘ Geology of Sussex ’ (plate xxxii. fig. 5); but this is scarcely complete enough to give any satisfactory clue to the entire armature of which it formed a part. Only nine teeth are shown, though these indicate portions of no less than four parallel rows, one represented by three components, and the remainder exhibiting buttwo. There is evidence of one series composed of relatively large teeth, and the rows immediately adjoining this on either side are so completely alike in character and dimensions as to appear quite symmetrically disposed in regard to it; while a still more diminutive series alone remains to the left. II. But the specimen of greatest interest in this respect still re- mains undescribed, and is shown of the natural size in Pl, X. fig. 1, lis precise locality is unknown, and there is some difficulty in its specific determination; but itis evidently a close ally of P. decurrens, even if not a variety of that form. Thirty-four teeth have been disengaged from the surrounding chalky matrix, and of these no less than twenty-three are shown in their natural order. There are remains of six parallel series, and the general appearance of the specimen is at once suggestive of symmetry about the row of largest teeth, which would thus be median when the dentition was com- plete. This series (0) is represented by five of its components, and it is noteworthy that there is scarcely any variation in size as they are followed from behind forwards; all, indeed, have approxi- mately the breadth of 0:021 m., and the length of 0:016m.* The series (1) immediately to the left of the median row is likewise * All the measurements are given in decimal fractions of a metre. K2 124 MR. A. S. WOODWARD ON THE DENTITION represented by five teeth, but of its homologue to the right only four remain. These teeth also vary but little in size, and their average measurements are 0°013 in a transverse direction, and 0:01 antero-posteriorly. They are not adjusted to the edges of the inter- posed large teeth with any marked regularity, having no definite relation to the interspaces; but each example appears to be slightly adapted in shape to fit whatever position it occupies. A second lateral row (2), similarly adapted to the outer border of the first, is indicated by six of its components to the left and by two to the right ; these are still smaller in size than the others, measuring only 0:01 by 0-009 on the left, though the two corresponding teeth situated more posteriorly on the right are a millimetre longer, and thus square. A still smaller and somewhat oblique series (3), forming a third lateral row, is represented to the right by a single tooth, the dimensions of which are only 0-008 by 0-008. This specimen affords an excellent opportunity of observing the character of the surface-ornamentation of the teeth in different parts of the mouth, and entirely confirms the conclusions of Agassiz based upon scattered groups. There is no variation of muportarice, and such as would lead to the establishment of more than one species if the teeth were found detached; and, except in size, the lateral teeth only differ from the median in being slightly flatter, and, in a few cases, somewhat oblique. III. Another fossil in the British Museum that may perhaps be referred to the same jaw as the preceding, though quite as probably belonging to the opposing dentition, is also of considerable import- ance, and is shown of the natural size in Pl. X. fig. 2. This is an un- doubted example of P. decurrens, obtained from the Chalk of Dorking, and forms part of the late Dr. Bowerbank’s collection (B. M., no. 39134). Twenty-one teeth are preserved in their natural relations, and these are the representatives of six parallel rows. The largest series, to the extreme right, is only indicated by a single one of its components; but of the second row there are three; of: the third, six ; of the fourth, six and the impression of a seventh; of the fifth, three; of the sixth, two; and on the back of the fossil there are several scattered examples of a seventh row (fig. 2,7). In each of these rows there is exceedingly small variation in size, and the maximum transverse and longitudinal measurements are as follow :— Series. Transverse Measure. Antero-posterior Measure. Hh. erase aa is) 0:023 0-017 DS Saas EME Ey, 0°015 ‘0-012 Deity ENE, 0-011 0-009 PL MRC Rp Ne Scat Se 0-009 0-007; Digi ere BN ane ba 0-008 0-006 Ga ee Maia ape ee 0-006 0°:005 Yi ee NO 0:005 0-004 The teeth are slightly more displaced than in specimen No. II.; but the irregular manner in which the components of one series are AND AFFINITIES OF PTYCHODUS. 125 adapted to the next is again very evident, and there is the same slight accommodative variability inshape. The superficial ornamen- tation is also equally constant; but there is a greater tendency to obliquity in all the teeth, this becoming observable even in series no. 2, and especially marked in the rows beyond. IV. A small example (fig. 3) of the same species from the Lower Chalk of Halling, Kent, affords the first definite indication of the second plan of arrangement already referred to. Only nine teeth are shown in their natural! relative positions, forming parts of three parallel rows; but in the absence of further evidence, the remarkable want of symmetry is a most perplexing characteristic. The middle series, represented by four of its components, is considerably the largest ; but in the two adjacent rows the teeth of the one side are notably smaller than those of the other, as shown by the following average dimensions :— Series. Transverse Measure. Antero-posterior Measure. Ue a ata ae 0-006 0-005 | inacetybiepene acacia 0-014 0-010 cad a ae are 0-010 0-007 It is also noteworthy that in the smallest teeth the peculiarities of the grinding-surface are somewhat abnormal, the peripheral eranulated area encroaching to such an extent upon the transversely furrowed portion that the latter becomes quite inconspicuous. VY. But a complete explanation of this specimen is afforded by Mr. Willett’s magnificent fossil from the Chalk of Brighton (Pl. X. figs. 4-10). Like most of the other comparatively undisturbed re- mains, it is referable to the common P. decurrens, and no less than thirty-four teeth are firmly cemented together in their natural rela- tions by slightly crystalline pyrites; while seventy others were originally associated with this mass, though now detached in small groups and isolated specimens. Of the jaw already described, only seven teeth are cemented in the main mass, and these belong to the median and the first left lateral row; but of the opposing jaw, hitherto entirely unknown, there are satisfactory remains of six longitudinal series, and certain detached fragments afford evidence of still more. Here, again, there is com- plete symmetry around a median azygous row ; and in describing the arrangement it will obviously be necessary to use the terms right and left in the opposite sense to that already employed in reference to fig. 1. The median series is scarcely visible on the grinding-surface, only a portion of one tooth projecting through the hard pyrites; but evi- dence of its presence is afforded by the distinct abrasion of the sum- mits of the opposing teeth, and one of its components is exposed on the back of the fossil, while two others are shown in a detached fragment. These teeth (fig. 5) are comparatively small, elongated antero-posteriorly, and, like those of the most diminutive row in Specimen No. IV., are somewhat abnormal from the circumstance that the granulated ornament considerably encroaches upon the 126 MR, A. 8S. WOODWARD ON THE DENTITION median area usually occupied by transverse ridges and furrows. Each tooth is narrowed in front, the blunt anterior end fitting into the slightly forked and broadened posterior end of its (SURES, and the root is ea deep. In the series (fig. 4,1) immediately adjoining this median row on either side are arranged the largest teeth of the jaw, measuring as much as 0-025 in a transverse direction, by 0-019 antero-posteriorly. These (fig. 6) are quite of the normal type, rectangular, not much elevated, and approximately equal in size, so far as is indicated by the ten examples preserved. The second lateral row (fig. 4, 2) is represented on the left by seven of its components, and on the right by four. These teeth only attain the average dimensions of 0-016 transversely, by 0-013 longitudinally, and there is little trace of obliquity; but a third and much smaller series, of which four teeth remain on the left (3), begin to exhibit a slightly rhomboidal form, and in their fossilized state are directed somewhat backwards. The latter have an average measurement of 0-012 by 0-01, and, like all the others of this jaw, do not exhibit any distinct traces of wearing. The main mass does not afford evidence of further lateral rows, though some are evidently broken away from each side. But a detached fragment of the fossil (fig. 7) shows three examples of the right row no. 3, flanked outside with three members of a fourth series, which are again smaller and measure only 0:01 by 0-007. These teeth are very oblique, and seem to have been followed by at least one, and probably more outer rows, though no certain proof is forthcoming. Of the opposing Jaw, as alr eady stated, only seven teeth are pre- served in their original positions, five of these representing the median series, and the remaining two belonging to the first lateral row on the left. A detached median tooth (fig. 8) also seems to fit in a hollow in the main mass, and this, being divested of all adherent pyrites, may be described as a very typical example. It is rather larger than the largest in the other jaw (fig. 6), and more trans- versely elongated ; and the crown of the tooth has a remarkably conical form, in consequence of the depth of the groove into which it is adapted to fit when biting. It measures 0°032 transversely, by 0-02 longitudinally, and the other corresponding teeth with worn summits are of approximately the same dimensions ; but two asso- ciated examples, evidently just developed and never functional, are of somewhat greater size, having a breadth of 0° 036 and a length of 0:023. The grinding-surfaces of the two lateral teeth im situ are obscured — by contact with the cementing pyritous matrix; but there are several loose specimens, and one is shown from two points of view in fig. 9. The dimensions are considerably reduced, averaging only 0-026 by 0-015; but there is the same transverse elongation, and the crown is likewise much elevated. It is also noteworthy that the examples showing most evident traces of wearing have a transverse measure- ment as much as four millimetres less than that of the newly AND AFFINITIES OF PTYCHODUS. 127 developed teeth of the same series, and there is a corresponding diminution in length. Remains of a second lateral row are preserved in contact with a detached series of the left row no. 1 (fig. 10), and these are, again, smaller (measuring 0°016 by 0-012) ; but it is not possible to distin- euish with certainty any of the teeth originally placed beyond. Exactly as in the previous specimens—and as is to be observed in all associated groups of Ptychodont teeth—there is no remarkable variation in the ornament of the grinding-surface in different parts of the jaw (except in the small median row), and it is interesting to be able to determine that there is no difference in this respect between the upper teeth and the lower. Mr. Willett’s specimen also supports the conclusion, based upon the National fossils, that there is no regularity in the plan by which one row of teeth is adjusted to the next, and offers many good examples of the slight adaptive variability in shape. But there is one interesting fact in regard to this adaptation which is not so clearly demonstrated in the majority of specimens, and whichis worthy of a passing note, since it affords a method of readily distinguishing ‘““lefts” from “rights.” The outer edge of every lateral tooth is more or less regular, being almost straight, andterminating anteriorly and posteriorly in a gentle rounded angle, while nearly all the modifications requisite to ensure the continuity of the dental arma- ture are provided by the variable inner edge, In-very many cases the posterior inner angle is produced considerably backwards (e. 9. fig. 9); but neither this nor the other adaptations appear to affect the extent of the transversely ridged median area. A further point of interest in the Brighton fossil consists in the well-marked character of the pressure-scars, produced—like those in the teeth of Proboscidian Mammals—by the forward progress of the dentition during growth. They occur as small polished patches, exposing in section the minute medullary canals with which the dentine beneath the surface is everywhere traversed ; and, as might naturally be expected, they are most prominently shown in the older anterior teeth. Typical examples are shown in figs. 8, 9. . Other teeth in the British Museum exhibit the same feature, though I am not aware of its having hitherto been noted, and scarcely any specimens show it so prominently as the example just described. V1., VIL. In the light of the foregoing facts, it will be interesting now to attempt a revision of the various specific types of the genus Piychodus, and to endeavour to interpret the numerous associated groups of teeth that are already within the reach of scientific Inquiry; but such will be a work of considerable extent, and it is beyond the scope of the present communication to enter this untouched field. It may be worth while, however, to append sketches of the median teeth of two of the species, for comparison with those of P. decurrens ; and the originals of figs. 11 and 12 are such teeth, belonging to P. polygyrus and P. paucisulcatus respectively. In tine former (fig. 11) the ordinary median area is reduced to a small conical 128 MR, A. S. WOODWARD ON THE DENTITION eminence with radiating furrows; while in the latter (fig. 12) the same part of the grinding-surface is represented by about three very short, comparatively broad ridges, and the anterior granulated portion is marked by delicate branching grooves. VIII. A concluding note may also be added upon a large median tooth of P. decurrens (fig. 13), which shows the extent to which abra- sion sometimes proceeded before the final shedding. The scar caused by the opposing row of diminutive median teeth has assumed extra- ordinary proportions, and there are also three well-defined lateral marks of wearing. Two of the latter are observed on the left, and a larger one, connected with the median, is situated somewhat posteriorly to the right. Conclusions. On taking a general glance at the fossils just described, and considering their peculiarities as mutually illustrative, it seems possible at last to determine the precise character of the dentition of Piychodus, at least so far as one species is concerned. The specimens numbered II. and V. (figs. 1 and 4) show distinctly the plan of ar- rangement of the two jaws, and the other small fossil No. IIT. (fig. 2) will obviously determine the number of parallel rows constituting the complete armature. Unfortunately, however, it issomewhat difficult te decide whether the latter specimen is truly referable to the jaw to which I supposed it to belong when my previously published diagram was sketched, or whether it rather appertains to the new type of dental arrangement revealed by Mr. Willett’s fossil. It is un- doubtedly an example of P. decurrens, and the rows marked 1 and 2 exhibit precisely the same relative proportions as those similarly denoted in specimen No. IV. (fig. 3); while there is no transverse elongation such as is evident in the most fragmentary jaw of No. V. (fig. 4). The larger tooth, on the other hand, does not agree very well either with the original of fig. 6 or that of fig. 8; but, on the whole, it seems most likely that the former is its homologue. Such being the case, there would be originally seven lateral rows on either side of the small median series, and the opposing jaw would almost certainly comprise an equalnumber. If, however, the large tooth in fig. 2 is one of a median row, there will only have been six lateral series in each. Having determined so much, it requires but little study to demon- strate that the dentition is that of a true Ray, and does not bear the slightest resemblance to that of the Cestraciont Sharks. Though, at first sight, the specimen No. IL. (fig. 1) might suggest its apper- taining to a single ramus of the jaw—vwith the largest series in the middle, much as in the living Cestracion—yet the absence of all obliquity in the rows, and their completely symmetricalcharacter, are features that at once forbid this interpretation ; and Mr. Willett’s specimen (No. V.) furnishes decided proof that such an idea is quite inadmissible. The two mandibular rami were thus placed almost in the same straight line, as is the case in so many of the living’ Rays, AND AFFINITIES OF PTYCHODUS. 129 and the symphysis (as usual in these fishes) produced no line of demarcation in the enveloping dental armature. This approximate determination of the affinities of Pt ychodus, indeed, seems to furnish a means of deciding upon the relative positions of the two jaws already described. For on examining recent Rays it will be observed that the contours of the dentition are nearly always slightly wavy, with a prominence at the symphysis of the lower jaw, and a corresponding groove in the upper; and this relation appears to be quite constant throughout the group. There can be little doubt, therefore, that the lower jaw of the extinct genus under consideration was armed by the teeth so well displayed in the original of fig. 1, while the upper was provided with- the series most satisfactorily shown in fig. 4. But with regard to the family with which the Ptychodonts ought properly to be associated, the dentition alone is insufficient to afford a definite clue. For among recent Rays the characters of the teeth are never of more than generic value*; and there is so much variation among the members of the same group that it is impossible to proceed beyond a hazardous speculation. Even so peculiar a dental arrangement as that of Myliobatis, for example, does not prevail throughout the entire family to which it belongs, since one genus (Dicerobatis) appears totally different and is armed with ordinary diminutive teeth, while another (Ceratoptera) possesses no dentition whatever in the upper jaw, and has nothing of importance in the lower}. Owen and others, as already remarked, have fre- quently noted the superficial resemblance of Ptychodus to the living Ehynchobatus, and it is quite possible that there may be some natural affinity; but in this form the teeth are diamond-shaped, with the transverse ridges extending from corner to corner; and their quincuncial arrangement and microscopical structure are serious obstacles to a belief in the suggested relation just mentioned. The arrangement of the teeth in parallel rows, crossing the rami at right angles, and their gradual diminution in size from the median series outwerds, are features perhaps indicating some affinity with the huge Myliobatide ; and it is in proximity to these that I would venture to assign the genus a place. Unfortunately, however, the broken fragments of cartilage that constitute the only part of the skeleton hitherto discovered are not sufficiently perfect to yield any more definite information ; and it is quite possible that we are here concerned with a representative of an extinct family as yet unknown to biological science. And, in arriving at sucha result, it is impossible to omit a passing allusion to Prof. Sir Richard Owen’s supposed decisive argument in a different direction, derived from a study of microscopical structure. The distinguished author of the ‘ Odontography ’ himself has doubtless long ago abandoned the ‘idea of being able to recognize fossil (rehaciont faa from an examination of ine pecu- * A. Giinther, ‘Catalogue of Fishes in the British Museum,’ vol. viii. pp. 434-498, | t A, Giinther, op. cit. pp. 496-498, 130 MR. A. 8S. WOODWARD ON THE DENTITION liarities of the vascular dentine; and as such investigations failed to separate the Dipnoan Ctenodus and Ceratodus—and, still more, the Psammodonts and Petalodonts—from the Cestraciontide, it is not surprising that they were likewise unsuccessful in correctly determining Ptychodus. Microscopical structure, in fact, seems rather to depend upon function, and not so much on genetic relationship. In conclusion, the question arises as to whence Ptychodus came, and whither its descendants, if any, departed. For, so far as is at present known, not a trace of this generic type occurs in any deposits beyond those of Cretaceous age; and no one has yet succeeded in discovering a Selachian tooth that is obviously a modi- fication of the form so common in the Chalk. Mantell’s Ptychodus Mortoni, it is true, is su ggestive of an approximation to a more ordinary type of tooth, and it is not improbably one of the missing links required ; and a Bohemian example, described by Reuss * as P. triangularis, is also worthy of special note for exactly the same reason. But the progress of paleontological knowledge is necessarily slow and uncertain, and we are compelled to remain satisfied with the present slight advance, while deferring the solution of these wider problems to a future occasion when still more materials may be available. EXPLANATION OF PLATE X. . Portion of lower dentition of Ptychodus, sp. (B. M., no. 40056.) . Portion of upper (?) dentition of P. decurrens. (B. M., no. 39134.) . Portion of upper dentition of P. decurrens. (B. M., no. 38564.) . Portion of upper and lower dentition of P. decurrens. (Collection of Henry Willett, Esq., F.G.S., Brighton Museum.) . Tooth of upper median series, found associated with the preceding specimen. . Tooth of upper series 1, associated with original of fig. 4. . Teeth of right upper series 3, 4, associated with original of 6. 4. . Tooth of lower median series, associated with original of fig. 4 . Tooth of left lower series 1, associated with original of fig. 4. 10. Teeth of left lower series i 2, associated with original of fig. 4. 11. Tooth of upper median series of P. polygyrus. (B. M., no. P 319.) 12. Tooth of upper median series of P. paucisulcatus. (B. M, no. 4358.) 13. Much-worn tooth of lower median series of P. decurrens. (B. M. no. 33247.) B. M. = British Museum. All the specimensare from the Chalk of Kent and Sussex, and are drawn of the natural size, with the anterior border in each case directed downwards. Fig. CO CO 1 OD On H GO bo Discussion. The Prestpent congratulated the British Museum on obtaining the assistance of so promising a young paleontologist as the author of the present paper. Prof, SrrLry expressed a high opinion of the paper. The subject was one of much difficulty, as was shown by its having baffled a * A. E. Reuss, ‘ Die Versteinerungen der béhmischen Kreideformation,’ pt. 1. (1845) p. 2, pl. i. figs. 14-19. This species was subsequently referred to Acrodus by A. Fritsch, ‘ Reptilien und Fische der bohmischen Kreideformation,’ 1878, p. 16 fig. 38. \ | | | ) | | | } a | | ii sigan’ esannnsr™ i th I ony i | \ sia sais EO Pa aes “Licata o eite RSet 25 TaN Sion PAC 4 RPh =: : Kees Seis ; i pai bh ny Se enone a es mi | ichael del etlith. | | mt ap | Quart.Journ. Geol. Soc. Vol. XLII. Pl. Ll j 1 Ws AYA We ‘ (ie te | ; ie Aly. Mintern Bros) — AND AFFINITIES OF PTYCHODUS. 131 naturalist of so much knowledge as Agassiz. There was a fine series of specimens of Ptychodus in the Woodwardian Museum at Cambridge; but although these showed the linear and parallel arrangement of the teeth and apposition of the jaws, and although the method of wearing resembled that of the Rays, the subject had not been dealt with by any one so clearly as the examples in the Brighton and British Museums had been worked out by Mr. Woodward. At the same time Prof. Seeley thought there was still some question if Ptychodus was really a Skate. It was certainly the type of a peculiar plagiostomous family. Mr. Newron pointed out that if the arrangement suggested by Mr. Smith Woodward was correct, the large teeth of the lower jaw ought to be worn on both sides, and those of the upper jaw on the inner side. ; Mr. Lypexxer said he had described a dental plate of a Myliobatis from the Eocene of {ndia which appeared to show an approxima- tion in its contour to Ptychodus. Dr. H. Woopwarp had not seen the Cambridge specimens, but noticed the very fine example from Brighton; the specimen now exhibited showed portions of the teeth of both jaws well preserved. He pointed out the absence of the Cestraciont prehensile teeth, and their replacement by crushing-teeth in Ptychodus. This was a most important observation of Mr. Smith Woodward’s. He thought the present discussion would throw some light on the peculiar erushing-teeth of Carboniferous Sharks. The AvrHor, in reply,said that in the paper he had treated the ques- tion of attrition. The lower median teeth were worn not only on each side, but also on the summit. The evidence at present seemed to him to leave it doubtful whether Ptychodus was the type of a new family or not. He agreed with Dr. Woodward that forms like Psammodus would have some light thrown on them by investigations into the dental arrangement of Ptychodus. 132 PROF. T. R. JONES ON NUMMULITES ELEGANS 9. Nore on Nummurites ELucans, Sowerby, and other Enerisa Noummuuites. By Prof. T. Ruovrrerr Jones, F.R.S., F.G.S. (Read December 15, 1886.) [Puate XI.] THERE being much confusion in the supposed relationship and published synonymy of Nummulites elegans (Nummularia*, Sowerby), I propose to offer some remarks on the history of this species, more especially as less trouble would have been caused if I had taken more care years ago, and examined all, instead of only some, of Mr. Sowerby’s specimens which have been associated with that name. Having just now seen (October 1886), for the first time, the “Sowerby Collection” at the British Museum (Natural History, Cromwell Road), I find that Sowerby’s labelled specimens of “ Nummularia elegans” are really the same as my variety Prest- wichianat of Nummulites planulatus, which the late Dr. Philippe De la Harpe regarded as a variety of NV. wemmelensist. Other specimens, however, which belong to true JV. planulatus, were confused by Sowerby with his JV. elegans. Specimens labelled “ Nuwmmularia elegans” on the original card, No. 44007 (1) in the ** Sowerby Collection,” are exactly such as come from the well-known bed “no. 29” (at the base of the Barton Clay) of Prof. Prestwich’s section of the strata at Alum Bay, Isle of Wight, in the Quart. Journ. Geol. Soc. vol. 11. (1846), p. 257, pl. 9. fig. 1. One horizontal section among them matches one of Sowerby’s drawings in the ‘ Mineral Conchology,’ pl. 538, namely the 10th figure on the plate (counted in the order of the figs. 1, 2, 3), included in “ fig. 2,” and probably magnified two diameters. The other drawings in ‘fig. 2” do not match the specimens from the bed “no, 29,” but those referred to in the text (p. 76, vol. vi.) as | having come from “ Emsworth,” and which are still in the Collection, and are so marked. ‘These so-called ‘‘ Emsworth” specimens | evidently belong to VV. planulatus, such as is found on the Continent, | as indicated by me in the Quart. Journ. Geol. Soc. vol. vill. (1852) | p- 850, note. In 1852, Mr. James De Carle Sowerby, at my request, showed me the “ Emsworth” (NV. planulatus) specimens at his own house; but, not comparing the figures and text of the ‘ Min. Conch.’ at the same time, and not seeing the others (that is, the real *‘ VV. elegans” of the Collection), we did not discriminate the two sets of specimens ; and my note (Q.J.G.8. 1862, p. 92), written on the occasion, refers only * The generic term Nuwmmularia used by Sowerby is an unnecessary synonym of Nwmmulites, Lamarck; and the reasons for preferring Nwmmulites to Nummulina ave given in full in my ‘ Catalogue of the Fossil Foraminifera in the British Museum,’ 1882, pp. 90, 91. T Quart. Journ. Geol, Soe. vol. xviii. (1862), p. 93. t Catal. Foss. Foram. Brit. Mus. 1882, pp. 22 & 92. i : Tt See Ann. & Mag. Nat. Hist. ser. 3, vol. viii. pp. 233, 234. AND OTHER ENGLISH NUMMULITES. i les to the NV. planulatus (allocated to Emsworth) alluded to in the text of the ‘ Mineral Conchology ’ at page 76, vol. vi. No locality is given for Sowerby’s real NV. elegans (pl. 538, part of fig. 2), though its identity with specimens from Bed “no. 29” cannot be doubted; and the mention of ‘‘ Emsworth” is made incidentally for the other Nummulite, about the relationship of which Sowerby may well have been uncertain. In the British Museum (“ Sowerby Collection”) we find No. 44007 (1) labelled ‘‘ Vummularia elegans, W.D.8.” There are several specimens mounted ona card. One is illustrated by the 10th figure (part of “ fig. 2”) on pl. 538, Min. Conch. vol. vi. (September, 1826*), and described at p. 76, under Nummularia elegans. No. 44007 (2) is the same, together with fragmentary shells, in a clay with glauconite and coarse quartz grains, much rounded. This is evidently the glauconitic clay-bed of the Barton series, part of “no. 29” of Prestwich’s Section at Alum Bay, Isle of Wight, Q.J.G.S. vol. ii. (1846) p. 257, pl. 9. fig. 1. As Sowerby’s “ elegans” is definitely the same as Nummuulites Prestwichianus (var. of planulatus), Jones, of the bed “no. 29,” and as Dr. Ph. de la Harpe determined some of these Barton (“ no. 29”) Nummulites sent to him to be a variety of NV. wemmelensis, we have three names for this little fossil. If it be a species of itself, the name elegans would have priority of any other, unless the commingling of the two forms in the ‘ Mineral Conchology ’ loc. cit. interferes with the value of the evidence of the original card with mounted speci- mens, iabelled “ WV. elegans” by Sowerby. It is unfortunate that Mr. Sowerby at the same time referred some specimens of another species (previously described by Lamarck as *‘Lenticulites planulata ”) to his JV. elegans, figuring them with it, and alluding to some of their features in his account of JV. elegans. Nevertheless it is easily distinguished both among his figures and among his specimens pre- served in the British Museum. Accepting “ elegans ” as subordinate to Vanden Broeck and De la Harpe’s N. wemmelensis, we must replace the varietal name of Prestwichiana by that of elegans, Doubtless, in a zoological point of view, wemmelensis is itself a variety of planulatus ; and this latter, as De la Harpe puts it, is a subor- dinate member of the V. Murchisoni group, or, as Prof. W. K. Parker and myself have regarded it, a variety of VV. perforatus lower than complanaius and its allies. Therefore elegans (Prestwichianus) is a variety of planulatus in our sense ; but it is not advisable to ignore the specific value of wemmelensis, on which Dr. De la Harpe has bestowed much careful research ; and N. wemmelensis, De la Harpe, yar. elegans, Sow., is a correct denomination for the Nummulite under notice. To proceed :—_ In the “Sowerby Collection” :—No. 44007 (8) contains the individuals shown by the 9th and 11th figures (part of “ fig. 2”) on pl. 538. No. 44007 (4) has the 6th figure (part of “fig. 2”) on * For the exact dates of the parts and volumes of this work, see Professor E. Renevier’s note in the ‘ Bullet. Soc. Vaudoise Sci. Nat.’ 2 Mai, 1855. 134 PROF. T. R. JONES ON NUMMULITES ELEGANS pl. 538. No. 44007 (5) has the 7th and 8th figures (part of “fie, 2”) on pl. 538. These are said to be from Emsworth, near Chichester, and consist of a siliceous shell-rock not otherwise known in England. These specimens, Nos. 44007 (3, 4, 5), were those which I saw with Mr. Sowerby in 1852, and understood to be NV. elegans. Recognizing them as N. planulatus, and probably foreign, and, not seeing the others, I did not adopt the name elegans, but designated the Barton specimens of bed ‘“‘ no. 29,” in which I was then interested, by a new name. t will be well to mention that in plate 538 of the ‘ Min. Conch.’ the Nummulites levigatus is illustrated by “fig. 1” at the top; N. variolarius by “fig. 3,” in the middle; and WN, elegans [and NV. planulatus| by “ fig. 2,” at the bottom. Counting the figures individually, for convenience of detailed reference (as De la Harpe does), “ fig. 1” comprises nos. 1-5, “ fig. 2” nos. 6-11, and “ fig. 3” nos. 12-17, counting in the order of figs. 1, 2, and 3; if in the order of actual position on the plate, the sequence would be different. Of “fig. 2,” at the bottom, no. 10 is the real ‘“ elegans” *, the others being VV. planulatus at different stages of growth7T, and from 3 to 10 millim. in diameter. Elucidative Scheme of Plate 538 ‘ Mineral Conchology.’ Fig. 1. ‘b ) | N. levigatus 2. 3. 4. ( (nat. size), 5. J Fig. 3 12. 13. 14. 15. 16. | . variolarius (nat. size and iDes magnified), Fig. 2. 6. ve 8. 9. 1): zB i “H+ Adult. Young. Vertical Horizontal Adult. section. section. ————e ~- — — N. planulatus NV. elegans N.planulatus (nat. size). (enlarged). (nat. size). * This horizontal section, differing from any such on the “ Emsworth”’ stone (on which, indeed, there are only one or two exposed), is like those of the specimens — from bed “No. 29;” and if magnified twice, as is probable, would be about 24 mm. in diameter. a “+ Such, for instance, as may be observed among a set of specimens of this Sy species from Foréts, near Brussels, and elsewhere. yr see Se ee ee AND OTHER ENGLISH NUMMULITES. 135 It may also be remarked that the labelled card, No. 44008 (1), with Nummuiites variolarius (Lamarck), contains the specimens figs. 12th, 14th, and 17th (part of “ fig. 3”) of pl. 538. No. 44008 (2) is WV. variolarius. No. 44008 (3), NV. variolarius, contains the 13th, 15th, and 16th figures (part of “ fig. 3”) of pl. 538. No.44008 (4), WV. variolarvus, without a locality, is a calcareous lump of these little fossils, certainly from France, like the coarser of the two specimens from Betz, Dep. Oise, “« P. 969,” in the British Museum ; ‘Catal. Foss. Foram. B. M.’ 1882, p. 38. 1826. The description of NV. elegans by James De Carle Sowerby, in the ‘ Mineral Conchology,’ vol. vi. p. 76, is as follows :— “ NUMMULARIA ELEGANS, Tab. pxxxviii. fig. 2. “Spec. Char. Compressed, smooth; whorls about six; septa gently curved from the axis, numerous [alar prolongations of the chambers|; aperture rather prominent. “This differs from the last [1V. levigatus] in being smaller, in having fewer whorls, which increase more rapidly, and in the regular curvature of the septa. When young, it is very smooth and regularly lenticular. ‘The large figure [V. planulatus | shows several series of diminishing chambers, as mentioned in the observations upon the genus [pp. 73-74]. ‘A siliceous stone occurs at Emsworth, near Chichester, that contains among other shells an abundance of these Nummulites [WV. planulatus| filled also with silex, the other shells are too imperfect to ascertain in our specimens. “Tt is an intermediate species between Lenticulina and Nummu- lites of Lamarck.” In this description some features of VV. planulatus are confused with those of elegans itself. The Emsworth stone referred to consists of siliceous internal casts of Mollusks (Bivalves and Gasteropods) and Nummulites, with siliceous cement. ‘This last was sandy, and contains some glauco- nitic grains. Inquiring of Prof. Prestwich in 1882, about this ‘“ Emsworth ” stone, I was favoured with a letter in which he informs me that he has “ searched in vain for the section with Nummulites at Emsworth, and that it may have been in a small temporary pit ina lane. The place itself is on the [lower] London Clay.” (‘Catal. Foss. Foram. Brit. Mus.’ 1882, p. 24.) “The village stands in greater part on Chalk and Gravel; but on the outskirts southward it passes on to the Lower Tertiaries, and possibly to the Bognor Beds” (Prof. Prestwich, November 10, 1886). A well, therefore, may reach some Lower Tertiary beds; but no siliceous fossils are known in them. Prof. Prestwich, however, has suggested to the author that, as very little is known of the “‘ Bognor Rock,” and nothing of its lower portion, it is just possible it may possess some peculiar stratum holding VV. planulatus; and that this would be such as on the Continent occupies the horizon equivalent to that of the London | Clay, including the Bognor Rock. 136 PROF. T. R. JONES ON NUMMULITES ELEGANS In the ‘ Proceed. Geol. Assoc.’ vol. u. (1872) p. 158, Mr. Caleb Evans referred to this Nummulite, described by Sowerby and found at ‘“‘ Emsworth Common,” as possibly indicating the presence of the ‘“‘ Bracklesham Series” at that place, about 3 miles to the east of Portsdown Hill. Mr. Clement Reid, F.G.S., who is also well acquainted with the country near Chichester and Havant, writes me (Oct. 23, 1886), in reply to inquiries :—‘ I have referred to all the maps, but cannot make out how any Nummulite rock can occur in situ at Emsworth. It may, however, be possible that Sowerby is right; for having worked within two miles of Emsworth, I find that as the Chichester synclinal is a good deal sharper than on our old Geological Survey map, Bracklesham beds may occur near.Emsworth. There is another possible explanation, namely, that Sowerby’s specimen was from an erratic block. There are several blocks of Bognor Rock scattered over the country.” Mr. Keeping, in a letter dated November 25, 1886, says—‘‘ The strata at Emsworth are London Clay and Woolwich beds; so we may be certain that the occurrence of the Nummulite is a mistake.” In the British Museum, the late Mr. F. E. Edwards’s collection contains several loose specimens of both NV. Prestwichianus and NV. variolarius, labelled as haying come from ‘‘ Emsworth ;” but this is exceedingly doubtful, for they and the small Mollusks and other fossils with some of them have every appearance of specimens from Barton and Higheliff. 1837. H. Galeotti, in his ‘Mémoire sur la constitution géognostique de la Province de Brabant” (Mém. couron. Acad. R. Belg. vol. xii. 1837, p. 141), quotes ‘ Nummnulina elegans, nobis et Sowerby, Min. Conch. pl. 538. fig. 2,” as occurring at Foréts, Jette, and Laeken, in Belgium, and at Barton! 1846. In Prof. Prestwich’s memoir “ On the Tertiary Formations of the Isle of Wight,” in the Quart. Journ. Geol. Soc. vol. 11. at page 254, bed no. 16 at Whitecliff Bay is said to contain “ Nwmmulites elegans” (the Rev. G. Fisher regards this as probably being WV. vario- larius, Q. J. G. 8. vol. xvii. p. 70; and it is near the position of Mr. Keeping’s Prestwichianus-bed, see p. 145); beds nos. 14-12 to contain IV. levigatus; and bed no. 11 to contain WV. elegans and scaber (referable to NV. variolarius and NV. levigatus). At page 257 the bed “no. 29” at Alum Bay is said to have NV. levigatus and NV. elegans. Here the latter agrees with Sowerby’s determination (see above) ; whilst the former species may occur lower down in the Bracklesham portion of the bed “no. 29,” but it is doubtful *. Mr. Keeping states that NV. variolarws (or a thick Prestwichianus) is met with in Mr. Prestwich’s “ no. 29,” in the upper portion of the brown part, and the flattened form midway between this and the base of that clay (Letter, November 25 & 29, 1886). 1848. In Bronn’s ‘ Lethea geognost., Index paleontolog.’ vol. i. * T did not note this species in Mr. Prestwich’s collection from Alum Bay in 1852 (see page 147). AND OTHER ENGLISH NUMMULITES. Loe p. 628, Sowerby’s N. elegans is referred to “ Lenticulites planulata,” Lamarck, with doubt. | 1850. Dixon’s ‘ Geology of Sussex,’ &c. 1st edition. P. 85. Nummularia variolaria, Sow. Min. Conch. t. 538. f. 3, Stubbington ; common. P. 85. WN. elegans, Sow. M. C. t. 538. fig. 2, Alum Bay, Isle of Wight; rare. P. 85. NV. radiata (Montfort), Bracklesham; rare: pl. ix. fig. 7; this is VV. variolaria with some of its septal lines raised externally. Mr. Sowerby himself drew up this list, and applied the name *‘ elegans” to the specimens from Alum Bay then under notice, haying already given that name to the same species from the same place in 1826, though unfortunately mingled with others (NV. plan- ulatus) in the description and figures. 1850. In his ‘ Histoire des Progrés de la Géologie,’ vol. iii. (1850), p. 236, M. d’Archiac states that, in Sowerby’s pl. 538. fig. 2, “les figures de droite, de gauche et la coupe du milieu,” named ‘‘ elegans,” may be“ WV. planulata” ; and at p. 240, thatin fig. 2 “les trois plus petites seulement” are “NV. planulata.” These three smallest figures, however, really comprise two of planulatus and one of elegans. 1852. In the Quart. Journ. Geol. Soc. vol. viii., at p. 350, Sir Charles Lyell added this note to his Memoir on the Belgian Tertiary Formations :— “Mr. T. Rupert Jones informs me that the Nummulite figured as JV. elegans in the ‘Mineral Conchology’ from specimens marked «Emsworth, near Chichester,’ and which Mr. J. de C. Sowerby has kindly permitted him to examine, is (as suggested by M. d’Archiac, Hist. Progr. Géol. vol. ii.) undoubtedly the WV. planulatus of conti- nental geologists. It is probable, therefore, that in that part of England where the Bracklesham beds with NV. levigatus are so largely developed, strata characterized by NV. planulatus also exist ; and it is highly desirable that their relative position should be care- fully studied.” The succession (downwards) of the Nummulites in Belgium is stated in Sir C. Lyell’s paper, op. cit. pp. 279 and 349, to be :— Sables moyens, | = Upper part of ou Grés de the Calcaire | V.variolarius. Laekenian. Barton Clay. Beauchamp. grossier. GANT: . ¢ Calcaire grossier. 1H Me \ Bruxellian. 1 eens Sables infé-) rieurs, Sables | pone [Not in Eng- =) SSS ee N. planulatus.{ Y a - eat mB partie supé- | Daan ay ape rieure. aon 1854. D’Archiac and J. Haime, in their ‘Monogr Nummulites,’ &e. (1853-54), p. 143, refer to Sowerby’s WV. elegans, ‘ Min. Conch.’ vol. vi. (1829), p. 76, pl. 538. fig. 2, as NV. planulata, var. a, pl. ix. * Had the Alum-Bay specimens, also labelled “ NW. elegans,” been examined at the same time, this name would have been retained for them. ___ * Unless in an unknown stratum of the “ Bognor Rock ” (see p. 135) | Q.5.G.8. No. 170. L 138 PROF. T. R. JONES ON NUMMULITES ELEGANS figs. 10,10a-c. At p. 146 they properly refer to Sowerby’s fig. 3 as LV. variolaria, and figure it in pl. ix. fig. 13. 1854. In Morris’s Catal. Brit. Foss. 2nd edit. p. 38, WV. elegans, Sow., is placed under Nummulites planulatus, Lam. 1862. The Rey. O. Fisher, in his Memoir “‘On the Bracklesham Beds,” Quart. Journ. Geol. Soc. vol. xviii., allocates Nummulites variolarius, levigatus, and Prestwichianus to their several beds of the Bracklesham and Barton formations, at pages 67, 70-84, and says (p. 84) :—‘** At Alum Bay the greater part of the fossiliferous beds in- cluded in No. 29 of Mr. Prestwich’s Section (Quart. Journ. Geol. Soc. vol. 1. pl. 9) may be correlated satisfactorily with those usually known as the Barton and Highcliff series. There is a well-known and marked seam of dark green sandy clay, containing abundance of Nummulina Prestwichiana. It contains Barton forms; and therefore we may safely carry the Barton series down so far, though it is lower in series than any bed from which fossils have hitherto been collected at Highcliff. The same Nummulite-bed occurs there also” (see ROT: 1862. At Whitecliff Bay part of the ‘No. 17’ of Prof. Prestwich’s section, Quart. Journ. Geol. Soc. vol. 11. p. 254, and of the xix. of Mr. O. Fisher’s section, Q. J. G. 8. vol. xviii. pp. 69 & 70, is regarded by Mr. Fisher as the equivalent of the green bands which form the base of the Barton beds at Highcliff and Alum Bay, and these contain the Nummulina planulatus [wemmelensis |, var. Prest- wichiana, . 1862. Quart. Journ. Geol. Soc. vol. xvii. pp. 93, 94. Appendix B to the Rey. O. Fisher’s memoir “‘ On the Bracklesham Beds.” “ Note on NummvLina pLanvuLatTa, Lamarck, sp., var. Prest- WIcHIANA, Jones. By T. Rupert Jones, F.G.S. “This little Nummulite is discoidal, smooth, and flat, rarely in any degree biconvex, even in the young state, unless the outer whorl has been flattened by pressure; about +{,;th inch in diameter, and 7th in thickness. The gently sigmoid and semitranslucent edges of the septa appear at the surface, and but seldom rise above it (except when the specimens are mechanically compressed, which is a common condition). The whorls (three [four] in large specimens) are all visible in empty shells made transparent by water or Canada- balsam; they are proportionally wide for Nummulina (the outer whorl making half[ 2th or 2th] the width of the disk). The chambers are about half as long as wide, neatly curved, but subject to irregu- larity of growth. The lateral portions of the chambers, though very - shallow, are continued over the surface towards the centre on each face, and are rather straighter in old specimens than in the young [?]. “This neat and delicate variety of Nummulina planulata, Lamarck, sp., has long been known in a clay containing much green sand, at Alum Bay, Isle of Wight (lower part of the bed ‘No. 29’ of Mr. Prestwich’s Section, Quart. Journ. Geol. Soc. vol. u. p. 257, pl. 9. fig. 1); but it has not hitherto been described *. It is near to MM. * The writer did not then know that Mr. J. De C. Sowerby had included this Nummulite under the description of WV. elegans in the Min. Conch. vol. vi. p. 76. AND OTHER ENGLISH NUMMULITES. 139 d@’Archiac and Haime’s Nummulites planulata, var. a, from Jette Belgium; but the latter has a biconvex centre (opake when mounted in balsam), has narrower whorls (in the proportion of | to 4, instead of 14 to 4), and grows to a somewhat larger size. To distinguish our variety (which characterizes a well-marked geological zone), 1 propose to give it the name of Prestwichiana; and, as the small biconvex variety of VV. planulata passes binomially as N. variolaria, so this small depressed variety of the same species may be allowed to stand on a similar footing, and be known as NV. Prestwichiana. “In the sandy clay-bed at Alum Bay the shells of this little Nummulite are very numerous, and often well preserved, but not unfrequently much crushed by pressure. In many specimens, especially large ones, the chambers are occupied by iron-pyrites ; and neat casts may be obtained by carefully dissolving the shell in weak dilute acid. In the clay at High Cliff the shells are not so numerous, are very much compressed, and so highly pyritized that they are readily destroyed by the atmosphere.” It may be added that even in the smaller specimens the alar chambers though “ radiate” are not straight, but curved; and in the largest individuals they become “‘sinuate”; therefore this form is one of the “ sinuo-radiates ” *, 1863. In a letter dated November 9, 1863, the Rey. O. Fisher wrote :— “This WV. Prestwichiana seems to range over what I have taken as the junction of the Bracklesham and Bartons. At Alum Bay the forms with which it occurs are Barton forms, while at Hunting Bridge it lies at the bottom of a thick bed of Bracklesham fossils.” He also refers to NV. variolaria, a species of the Barton series, as occurring at King’s-Garden Gutter, New Forest (“ Brook,” F. Hdwards), “‘ rare, but persistent.” 1876. Ann. & Mag. Nat. Hist. ser. 4, vol. xvii. p. 286. Among some fossil Nummulites dredged up in the English Channel, J. Prestwichiana was met with, and it is noted that this last form was described in the Quart. Journ. Geol. Soc. vol. xviii. pp. 93, 94, as NV. planulata, var. Prestwichiana, and possibly may be essentially the same as VV. planulata, var. a. minor, dA. & H., which occurs at Jette, in Belgium.” 1878. Dixon’s ‘Geology of Sussex,’ &c., 2nd edition by T. R. Jones. Page 172. Nummulina variolaria (Lamarck). Strongly ribbed ; plex. (10), fig. 7. | Page 172, note by T. R. J. :— *“Nummulina elegans, Sow. ‘Min. Conch.’ t. 538, referred to at p. 85 in the First Edition, was [in part] originally described from a specimen said to have come from a well f at Emsworth, near Ports- mouth. It is not known anywhere else in England. The figured specimen [11th figure in fig. 2 of the plate] closely resembles speci- * Ann. & Mag. N. H. ser. 3, vol. v. p. 109, vol. viii. p. 115. + I do not know where I learnt this fact; perhaps Mr. Sowerby gave me the information. L2 140 PROF. T. R. JONES ON NUMMULITES ELEGANS mens from Belgium. WN. Prestwichiana (Quart. Journ. Geol. Soc. vol. xviil. p. 93), from the junction-beds of the Bracklesham and Barton series at Alum Bay, may have been mistaken for [on the contrary, was correctly given by Mr. Sowerby as] JV. elegans in the catalogue at p. 85 of the First Edition.” 1879. Writing (October 1, 1879) about some English Nummulites which I had sent to him, Dr. Philippe De la Harpe explained his views about Nummulites wemmelensis, and the variety Prestwichiana, which latter I now refer to Sowerby’s elegans; and he stated that of NV. wemmelensis (which, though rare, occurs at Brussels, Jette, Wem- mel, Laeken, Ghent, and Briendereck in Belgium) he recognized the following varieties :— 1. Type: size 2-3 millim.; shape imvgouldete lenticular, with knob in the centre; surface smooth. Wemmel and Jette. 2. Var. plicata: size iL 4-2 millim.; shape lenticular, with de- pression in the conte: surface plicated. Ghent. 3. Var. granulata: size 11-2 millim.; shape flat, surface granu- lated. Brussels, Park St. Gilles. 4, Var. minor: size 1 millim.; lenticular, smooth, regular. &. Var. Prestwichiana [elegans]: size 1-2 millim. ; flat, smooth, regular. The spire is very nearly the same in all the varieties; the last is always much larger than the foregoing whorl. By its variations this species has affinities with WV. variolarius, with Assilina, and with Operculina *. In the ‘Catal. Foss. Foram.. Brit. Mus.’ 1882, pp. 91-93, I stated that ‘“‘ the proposed specific name ‘ V. wemmellensis’ for the type to which my ‘WN. planulata, var. Prestwichiana’ evidently belongs, had such strong justification, that I acceded to the accep- tation of my friend Ernest Vanden Broeck’s suggestion. Still, for convenience, the term ‘ Prestwichiana’ has been frequently entered in the Catalogue, as a synonym.” It seems now that elegans has priority, if not over wemmelensis, yet over Prestwichiana as one of its varieties. | This Prestwichiana or elegans is one of the Nummulites which have a large primordial or central chamber, VV. wemmelensis also having the character typically. In Belgium the late De la Harpe found eight species, consisting of four pairs of Nummulites, one of each pair having a very small, and the other a large central chamber, thus :— Small central chamber. Large central chamber. NV. elegans, De la H. (nos. 9 and 11 1. NV. planulatus, Lamarck .........+0+++- of Sowerby’s fig. 2. pl. 538). WN. planulatus, D’Archiac. 2. N. levigatus, Lam. (Type and va-\ yp amarchki. d’Arch rieties scaber, rotula, alone). ; ; 5 3. NV. Heberti, d’Arch. ENA ese ois ae Oe N. variolarius, Lam. ; -, { NV. wemmelensis, Vanden Broeck (= 4, N. Orbignyt ( Operculina, Galeotti). { N. planulatus, var. a, vel min tL * See De la Harpe’s letter in the ‘Catal. Foss. Foram. Brit. Mus.’ p, 92. EE ——————— AND OTHER ENGLISH NUMMULITES. 141 Among Nummulites in general, the same pairing of species holds good, thus :— Central chamber A____. aoe e—- oy tee Poe Small. Large. N. perforatus. N. Lucasanus. N. Brongniarti. N. Molli. N. complanatus. N. Tchihatcheffi. N. gizensis. N. curvispira. N. contortus. N. striatus. N. biaritzensis. N. Guettardi. Assilina exponens. Assilina mamillata, A. spira. A. subspira. See Catal. Foss. Foram. Brit. Mus. pp. 92, 93. The constant association, in the same strata, of large individuals with a small, and small individuals with a large central chamber, is more fully treated in Dr. Ph. De la Harpe’s ‘‘ Memoir on the Nummulites of Switzerland” (Mem. Soc. Pal. Suisse, vol. vii. 1881), at p. 63, &e., thus carrying out to a practical result the obser- vations made by Prof. Parker and myself in the ‘ Annals Nat. Hist.’ ser. 3, vol. vu. 1861, p. 233. Dr. De la Harpe, however, appears not to have seen this paper, nor our “ Notes on Nummulites,” op. cit. vol. v. 1860, pp. 109, 294, &c.; nor Carpenter, Parker, and Jones’s observations in the ‘ Introd. Study. Foram.’ Ray Soc. 1862, pp. 262-276; at least he does not refer to them in detail. 1881. ‘Etude des Nummulites de la Suisse,” &c., premiére partie, Mém. Soc. Paléontol. Suisse, vol. vii. At page 29, referring to some forms which he thought that D’Archiac had confused under the name of planulata, Dr. De la Harpe stated that the little form, with large central chamber, figured by Sowerby as JW. elegans, ‘ Min. Conch.’ pl. 538. figs. 6-11 [Sowerby’s “fig. 2”], and taken by D’Archiacfor young WV. planulatus, should retain the name given by Sowerby. I consider the nos. 6-9 and 11 (in “fig. 2”) to be really NV. planulatus of different stages of growth ; but, coming under that genus instituted by Lamarck, they did not require anew name; whilst “no. 10” is one of the specimens on Sowerby’s card labelled “ Nummularia elegans,” and forming the chief subject of his para- graph on JN, elegans, op. cit. p. 76. Dr. De la Harpe having found some small lenticular planulati with a large central chamber, regards them as one of his twin species. Nos. 7 and 8 in Sowerby’s “fig. 2” are like these exter- nally, and may or may not have the large central chamber. At all events they either are or have been mixed up, in the siliceous rock of “ Emsworth,” with planulatus (nos. 6-9, and 11). Even if they be the same as De la Harpe’s twin species referred to (Numm. Suisse, pl. 7. figs. 12-23), they cannot be called elegans, as that name is on Sowerby’s label of the Prestwichiana variety from Alum Bay. 142 PROF. T, R. JONES ON NUMMULITES ELEGANS 1883. In the posthumous portion of our deceased friend Dr. Phil. De la Harpe’s ‘‘ Etude des Nummulites de la Suisse et Révision des Espéces Hocénes des Genres Nummulites et Assilines,” partie troisicme (Mém. Soc. Paléontol. Suisse, vol. x.), 1883, p. 169, we have the synonymy of the little Nummulite under notice thus given :— Noummourires WeMMeEtensis, De la Harpe and Vanden Broeck, pl. xi. figs. 52-70. (Var. Prestwichit, figs. 65-70.) 1822. Nummulites lenticula (pars), Defrance, Dict. Sc. Nat. vol. Xxxv. p. 226. 1837 (?). Id. (pars), Galeotti, Mém. constit. géogn. Brabant ; Mém. Acad. Belg. vol. xu. 183 (eve began (pars), Galeotti, op. cit. 1853. N. planulata, d’Orb. var. a. minor, D’Arch. et Haime, Monogr. Numm. p. 1438, pl. 9. f. 10, a, b, ¢. 1861. Zd. Lam. sp., var. Prestwichiana, R. Jones, Quart. Journ. Geol. Soc. vol. xvii. p. 93. At p. 171, De la Harpe, under “ Nummulites planulata, Lamarck sp.” (pl. vu. figs. 1-11), places :— “©1829. Nummularia elegans (pars), Sowerby, Mineral Conchology, vol. vi. p. 76, pl. 548. figs. 6, 7, 8 (non figs. 9, 10, 11).” Excepting no. 10, these (Sowerby’s “ fig. 2”) are in my opinion definitely VV. planulatus (Lam.). At p. 175, under “ Nummulites elegans, Sowerby ” (pl. vu. 12-23), De la Harpe places :— “1829. Nummularia elegans (pars), Sow. Min. Conch. vol. vi. p. 76, pl. 538. figs. 9, 10, 11 (on 6, 7,-8).” | Phese also, exe cepting no. 10, are VV. planulatus; De la Harpe’s figures 12-20 are like young planulatus with large central chamber, and externally like some (nos. 7 and 8 of Sowerby’s “ fig. 2”) which accompany other planulati of larger growth. His figs. 21-23 represent a very thin form (“ depressa”’). The English Nummulites. I. NummczLires pLucans, Sowerby. Pl. XI. figs. 1-9. The following synonymy of JN. elegans, Sowerby, is here offered — as being in accordance with what we have noted above :— 1826. Nummularia elegans (part.), Sowerby, Min. Conch. vol. vi. p. 76, pl. 538. fig. 2 (part, namely, no. 10). 1837. Nummalina elegans (part.), nobis et Sowerby, Galeotti, Mém. constit. Géogn. Brabant, p. 141. 1846. Nwmmulina eleg gans, Prestwich *, Quart. Journ. Geol. Soe. WOME ps Zoe 1848. Lenticulites planulata (?), Bronn, Index Palzont. vol. i. p. 628. * At p. 254 N. variolarius appears to have been misnamed elegans. AND OTHER ENGLISH NUMMULITES, 148 1850. Nummularia elegans, Sowerby in Dixon’s Geol. Sussex, p. 89. 1850. Nummulites planulata (part.), D’Archiac, Hist. Progrés Géol. vol. ii. pp. 236 and 240. 1853. Nummulites planulatus (part.), Jones, Quart. Journ. Geol. Soc. vol. viii. p. 350, note. 1854. Nummulina planulata, var. a, vel minor (part.), D’Arch. & Haime, Monogr. Num. p. 1438. 1854. Nummulites planulatus (part.), Morris, Cat. Brit. Foss. 2nd edit. p. 38. — 1862. Nummulina planulata, var. Prestwichiana, Jones, Quart. Journ. Geol. Soc. vol. xviii. p. 93. 1878. Nummulina planulata, var. Prestwichiana, Jones in Dixon’s Geol. Sussex, 2nd edit. p. 172, note. 1881. Nummuiiies elegans (part.), De la Harpe, Numm. Suisse, part i. p. 29. 1882. Nummulites Wemmellensis, var. Prestwichi, De la Harpe, Catal. Foss. Foram. Brit. Mus. pp. 92, 93. 1883. Vummulites Wemmellensis, var. Prestwichiana, De la Harpe, Numm. Suisse, part iii. p. 169. 1886. Max yon Hantken in the Foldtani Kozlony, xvi. Kotet, 1886, in a paper on some American Nummulites (p. 188), pl. 1. fig. 4, gives “ NV. elegans” after De la Harpe, Etude Numm. Suisse, p, 175, pl. 7. f. 12-23, with 5 whorls, not rapidly increasing. In addition to the general description of LV. elegans (Prestwichiana) given above at page 138, the following notes on its size and proportions will be useful in its identification. (Mr. C. D. Sherborn has kindly given me his help in measuring the small English Nummulites.) Sowerby’s figure* no. 10 in “fig. 2,” magnified probably two diameters, represents a specimen about 21 millim. across, with 4 whorls, there being the following number of chambers in the whorls :— Ist. 2nd. ord. Ath, tf 14 oe 30? Sowerby’s specimens (from the bed “no. 29,” Alum Bay), flattened by pressure, are of various sizes, as usual ; and one, broken open (not artificially bisected *) and not well preserved, gives :— * Sowerby’s mounted specimens of “ N. elegans” from Alum Bay do not offer any good horizontal sections. Those that havetheir median chambers exposed have been broken open, in breaking the matrix, with such an uneven fracture that they do not show sections of an even plane like that seen in specimens carefully ground down, and hence they have the central chambers obscure. 144 PROF. T. R. JONES ON NUMMULITES ELEGANS Measurements in Number of chambers millimetres. Newbee in the whorls. of whorls. Diameter. | Thickness. Ist. |2nd. | 3rd.| 4th. One of Sowerby’s Be 12 2? 4 9°1 131 1431 203 PIONS PA saeMde se ese see see lee it 1 | 13 ri 4 14 Specimens from Alum Be 4 Bay (bed “no. 29”) { a 1 flattened by pressure. oR 3 \| ordinary ae 4 From Whitecliff Bay (Keeping’s Prestwichi- ene 3 4? anus- -bed). Nearly all 3 4? the specimens are flat- | ne $ 4? tened by pressure...... ] < 1 From Highceliff (“‘ D,” el S 4 Keeping), not flattened 3° +I by pressure .........+6. Qn 3 ae: } | 12 roa 4 From Hunting Bridge, 1a e : New Forest 4 5 3 4° Bie the | 9 9 4° 2 Zi ideas : 4 2 In Bed “no. 29” the specimens are thin and compressed, with the alar prolongations (“ ale,” or lateral extensions) of the chambers nearly all reaching the centre, somewhat curved; more sinuous and less regular in old individuals (Pl. XI. fig. 1). From the Hunting-Bridge beds specimens given to me by the Rey. O. Fisher, F.G.S., are only slightly. flattened; their ale reach the centre. Mr. Keeping’s specimens “ B,” from Hunting Bridge, are not flattened ; their ale generally, but not in every case, reach the centre. Those from Highcliff (Keeping, “D”’) are not flattened ; their ale reach the centre. Some individuals of elegans have partially radiate or plicate surfaces, due to the lessening of the septal ribs and a local convexity of the alar parts of the chambers, probably the var. plicata, De la Harpe (see above, p. 140). For the localities of Sowerby’ sy. elegans (or Pr estwichiana) we find in the ‘ Cat. Foss. Foram. Brit. Mus.’ 1882, pp. 22-25 (besides the Bed ‘‘no. 29” at Alum Bay) Bracklesham, F. Edwards ; biconvex variety, Bracklesham, F. Edwards; Barton, F. Edwards; Barton, with JV. variolarius, F. Edwards; Emsworth, with WV. variolarius, * In the Museum of Practical Geology, Jermyn Street. See Pl. XI. fig. 1. t These were ground down without their thickness having been measured. They probably ranged about 4 millim. ihiscaaeeitinan manna ET To . en Se eaapees AND OTHER ENGLISH NUMMULITES. 145 F. Edwards; and Emsworth, with Turbinolia, F. Edwards. Of these some, if not all, may have been wrongly localized (see above, page 136). Further, from Bramshaw, Brook, and Highcliff ; the last is thickish and associated with JV. variolarius ; all from the late Mr. Fred. Edwards’s Collection. Some rare, dredged off Guernsey, as noted in the Ann. & Mag. N. H. April 1876, p. 283. We have received from the Rev. O. Fisher and Mr. Keeping some from Hunting Bridge and from Highcliff, also some in a glauconitic clay from Whitechff Bay, found by Mr. Keeping in a zone just below “no. 17” of Mr. Prestwich’s Section *, and 13 inches thick. This is regarded as equal to a part of “no. 29,” Alum Bay. The specimens are both large and small, compressed, and not pyritous. I may mention that not only did Prof. Prestwich give me characteristic specimens of the Prestwichianus and variolarius from their several beds in or about 1852, but I took a note of the occurrence of these and other Nummulites as then preserved in his Collection. IJ. Nomuoutires vartotartius (Lamarck). Pl. XI. figs. 10-14. 1804. Lenticulites variolaria, Lamarck, Annales du Muséum, vol. ¥. p. 187, no. 2. 1826. Nummularia variolaria, Sowerby, Min. Conch. vol. vi. p. 76, pl. 538. figs. 3 (nos. 12-17). 1854. Nummulites variolaria, D’Archiac et Haime, Monogr. Numm. p. 146, pl. 9. fig. 13. Nummulina et Nummulites variolaria, auctorum f. Small, smooth, lenticular, with a rather sharp edge; the alar extensions are numerous (18—20 visible), distinct, long-triangular, nearly all reaching the umbo on the convex faces of the shell; the median chambers are usually about as high as long; central chamber rather large; the whor!s four, regular, increasing slowly. Occasionally the septal lines become thickened and raised, chiefly by a lessening of the shell-matter along the alar intervals; and a radiately-ribbed appearance is thus given to the shell. A swollen condition of the alar extensions also, in some cases, gives a similar appearance. See ‘Min. Conch.’ pl. 538. fig. 3: (no. 16); and Dixon’s ‘ Geol. Sussex,’ pl. 9. fig. 7. : The alar parts of the chambers, in passing to the umbo, often vary from their usual straight line to a gently curved, and even faleate form, thus passing from the “radiate’’ to the “ sinuo- radiate” type of Nummulite. They rarely interfere one with another. The umbo is always conspicuous, and sometimes flattened. The alar - septa are often strong, but not so thick as in the young NV. planulatus. The latter, moreover, soon loses its convexity between the umbo and margin; in its young state it is ‘radiate,’’ and in the adult condition fully “‘ sinuo-radiate.” See Ann. & Mag. N. H. ser. 3, vol. vill. pp. 233, 234. P Bere above, page 138. “No. 16” contains WV. variolarius as a characteristic OSSI11. t Some remarks by Dr. Ph. De la Harpe on this species are given in the ‘Bull. Soc. Géol. France, sér. 3, vol. v. pp. 826, 827 (1879). 146 PROF. T. R. JONES ON NUMMULITES ELEGANS The dimensions of NV. variolarius are :— Measurementsin | Number of chambers in millimetres. | N the whorls. | umber of whorls. Diameter. | Thickness. Ist. |2nd. | 3rd.| 4th. | 5th. —— en | =) | oe een ee eS —— = =— | or. figure (no. 14, ‘| 9 JM pets OK ieee ancients a { 3 2 + roe Ii leg Wr ff 72223 Sinbpington * scigena le ; if! 3 + 2? | 14 | 18 | 26? 1z Whitecliff Bay, bed no. | 2 16 of Prestwich’s sec- 13 a 4? TandO af he OM gy 55. ern pee eeee 12 Whitecliff Bay, bed no. li 11 of Prestwich’s sec- 13 5 4 P1438 | 1577202 IOUT. sotact ewes sce se sees 13 Kine’s-Garden Gutter f, - + | NewForest (O.Fisher). l 3 4 | Three individuals of a 13 | | large variety from the | 2 d 5 6 |11 | 16| 17 | 20m Barton Sheil-bed ...... | 2 | | | \] The three last have a large central chamber; one has straight, another oblique, and another ‘curved alar divisions. In the ‘ Catal. Foss. Foram. B. Mus.’ 1882, this species is entered as occurring (p. 22) at Alum Bay, in the bed “‘no. 29” (on the autho- rity of Mr. F. Hilary: At page 23-25 are the following :— Bracklesham, Barton, and Stubbington, including large, ordinary, and small forms; Emsworth (F. Edwards), probably a wrong locality ; Bramshaw, ordinary and large (F. Edwards) ; Highcliff, ordinary and large (Ff. Edwards). At p. 26, “a delicate variety like WV. venosa,” from Headon Hill (F. Edwards), is mentioned. Also Hunting Bridge and Shepherd’s Gutter (Bramshaw), New Forest, O. Fisher, Quart. Journ. Geol. Soc. vol. xviii. pp. 79 and 81. In the Quart. Journ. Geol. Soc. vol. xvii. 1862, the Rev. OQ, Fisher specially notes the occurrence of JN. variolarius in the Bracklesham series at Whitecliff Bay, in his division xvii. (p. 70), part of Prestwich’s “no. 16,’ Quart. Journ. Geol. Soc. vol. ii. p. 254; in xiv. (p. 71), part of Prestwich’s “no. 14 ;” in ix. (p. 72), Prestwich’s “no. 13.” At Bracklesham Bay (p. 74) in the beds numbered 22 and 21 and 20. Also (pp. 77-83) at Stubbington, Hunting Bridge, Shepherd’s Gutter, and King’s-Garden Gutter. According to Dr. De la Harpe the NV. variolarius of the Barton beds of Stubbington and White-Cliff Bay is the same as that of * Quart. Journ. Geol. Soc. vol. xviii. p. 78. Tt Mr. Keeping also has contributed some from this zone of NV. variolarius, which he finds to be 19 feet thick. t This is the “ Brook” locality of F. Edwards. AND OTHER ENGLISH NUMMULITES. 147 Belgium, and typical. He did not find WV. Heberti (having a small central chamber) with it, though accompanying it in Belgium and France. III. Nummvurires tavieatus (Bruguiere). This species has been so well described by D’Archiac and other authors * that its structure need not be treated of here. It is well figured in the ‘ Min. Conch.’ vol. vi. pl. 538. fig. 1. The range of Nummulites levigatus in England is limited. The Rev. O. Fisher has carefully defined its zones and _ localities, Quart. Journ. Geol. Soc. vol. xviii. In the Bracklesham series at Whitechff Bay (p. 72) in the bed VII. (part of Prestwich’s smowel2): in VI. (Prestwich’s “no. 11”); in LV. (Prestwich’s “no.9”). At Bracklesham Bay (p. 75) in the beds 6 and 4; and at Bury Cross, near Gosport (Pilbrow). At Alum Bay its zone was indicated by Prof. Prestwich many years ago as a lower part of that thick bed, no. 29, which also comprises the glauconitic clay with NV. elegans, Quart. Journ. Geol. Soc. vol. il. p. 257; but this is very doubtiul. WV. levigatus has also been found in the Wells at Wel- lington College and Woking Asylum. According to Dr. Ph. De la Harpe the Bracklesham Nummulites comprise both WV. levigatus and N. Lamarcki, the latter having a large central chamber ; and he thought that they indicate a horizon “at the top of the ‘Paniselian’ or at the bottom of the ‘ Brux- ellian’ Stage.” Catal. Foss. Foram. Brit. Mus. p. 91. A table of the range of Nummulites in England is given on the next page. * Dr. Ph. De la Harpe (‘ Num. Suisse,’ 1881, p. 29) has noticed that in his synonymy of this species in the ‘Prodrome,’ vol. ii. 1850, 25¢ étage, 1302, D’Orbigny has by mistake given the name of elegans instead of levigatus to fig. 1. pl. 588, ‘Min. Conch.’ 148 PROF. T. RB. JONES ON NUMMULITES ELEGANS Table of the Range of Nummulites in England. Numm. | Numm. : Numm. Numm. | , | variolarius. ease levigatus. planulatust a Alun Bay ........- In bed “no. 29” ?|/In part of Prest-| In part of Prest- i F, Edwards. wich’s “no. 29”| wich’s bed “no. bed. O. Fisher's!) 29”? bed 10 (p. 84). Whitecliff Bay ...,| In Prestwich’s beds} In bed just below) InPrestwich’sbeds 16, 14, 18, 11:] Prestwich’s 17 bed} - 12, 11, 9. In xvii., xiv., ix. of| (Keeping) Tt. O. Fisher’s beds O. Fisher’s beds. Vii., Vi., iv. Bracklesham Bay.| In O, Fisher’s beds | ?(F. Edwards). | InO.Fisher’s beds | 22, 20. 6, 4. Barton Cliff ...... | * ? (F. Edwards). Highcliff.....2...... | * x Fisher and Keeping. | Stubbington ...... | * Hunting Bridge, * * Fisher and New Forest. Keeping. Shepherd’s Gutter, or Bramshaw. King’s-Garden | * Gutter, or Brook. Emsworth ......... (80 Hidwards). 0") prsas es SRI (pass ones » Sowerby EXPLANATION OF PLATE XI. Fig. 1. Nummulites elegans, Sowerby. The largest individual known, | x 10 diam. From Whitecliff Bay: collected by Mr. Keeping f (Geol. Mag. 1887, pp. 70-72). Museum of Practical Geology. 2. The same. Ordinary example. x 10 diam. | 3. The same. Vertical section. X 10 diam. Be ee 4. The same. Horizontal section; from a transparent Bay. individual in Canada balsam. xX 20diam. * J t In Prof. Prestwich’s collection several years ago I noted among his specimens from Whitecliff Bay, in bed 16, variolarius; in bed 13 or 12, levigatus and var. scabra; and in bed 11, seabra and variolarius. From Alum Bay only } N. elegans, from ‘no. 29.” ; t A small derived or remanié specimen of NV. planulatus (near N. Boucherz, De la H.) has been found in the Crag of Suffolk; see ‘Foraminifera of the Crag,’ part i. Pal. Soc. 1866, p. 74 &c., pl. 2. figs. 51, 52. PL XI Quart.dourn. Geol. Soc. Vol XLII = ee : eS Se Geo West & Sons lith et Rony. Ss. SOME ENGLISH NUMMULITE ek, hers Ls AND OTHER ENGLISH NUMMULITES. 149 Fig. 5. The same. Ordinary example. x 10 diam. 6. The same. Vertical section of es individual. | Bene Haat x 10 diam. a 7. Thesame. Edge view. X 10 diam. ms Bees, 8. The same. Horizontal tes X 20 diam. | New Forest. 9. The same. Part of horizontal section. xX 55 diam. 10. Nummulites variolarivs (Lam.). Large individual. \ < 10 diam. The dotted line around the figure in- | From the Bar- dicates the size of a larger individual. ‘ ton Shell- 11. The same. Large individual. Edge view. | bed. x 10 diam. 12. The same. Ordinary variety. Horizontal section. x 20 diam. From Bed “ No. 16” at Whitecliff Bay. 13. The same. Ordinary example. x 10 view, om Bed “No. 11” 14, The same. 9 ” Edge view. at Whitecliff Bay. x 10 diam. Discussion. The PREsmDENT Said that the rectification of the name of an old species was of equal importance with the institution of a new form, and congratulated Prof. Rupert Jones on having cleared up an obscure question. Dr. Woopwarp was glad that Prof. Rupert Jones had found some materials previously unrecorded in the Museum collections, The number of specimens exhibited at the new Museum was fortunately much larger than formerly in Bloomsbury. Prof. Szrztzy spoke of the importance of determining the forms of Nummulites, and gave a sketch of their distribution in the British Eocene rocks. He also called attention to the variation of the different forms. The AvrHor said that the subject of the passage between different so-called species of Nummulites alluded to by Prof. Seeley was very interesting. His own view was that all the forms of Nummulites passed into each other, the whole genus being in fact one very variable species. 150 PROF. P. M. DUNCAN ON THE ECHINOIDEA OF THE 10. On the Ecuinorea of the Cretaceous Strata of the Lower Narpapda Recion. By Prof. P. Marrim Douwean, F.R.S., F.G.S. (Read January 12, 1887.) Owine to the kindness of H. B. Medlicott, Esq., F.R.S., Director of the Geological Survey of India, I have lately received a consider- able number of specimens of Echinoidea, which have been obtained from recorded localities, from the Cretaceous formation, in the Lower Narbada valley. A small collection of Echinoidea, Mollusca, and Brachiopoda, and a coral are in the Museum of this Society, and they came from the neighbourhood of Bag on the Narbada, in the same district whence the forms lately received were found. This small collection was described by me in a communication to this Society in 1865, another collection from 8.E. Arabia being associated with it, and an Upper Greensand horizon was given to the strata containing the species (Quart. Journ. Geol. Soc. vol. xxi. p. 349). The persistence of many well-known European species into the far east was noticed. In 1866 *, Messrs. Blanford and Wynne surveyed the Bag district, and decided that the succession of the Cretaceous rocks was, from below upwards, as follows :—Sandstone and conglomerate, 20 feet ; nodular limestone, nearly unfossiliferous, 20 feet ; argillaceous lime- stone, fossiliferous, 10 feet ; and coralline limestone (Bryozoan) 10 to 20 feet. The relation of these conformable beds to the overlying Lameta beds and the Deccan and Malwa Trap was noticed. The surveyors accepted my decision regarding the age of the beds which had yielded the fossils, namely the argillaceous beds near Deola and Chirékhan. In 1868 a similar horizon was stated to be present in the Sinai area ; it was already known in Algeria; and later on, Fraas and Cotteau discovered it in the Lebanon. The little collection from Bag became very interesting when Stoliczka’s great work on the Echinodermata of the Cretaceous rocks of S. India was published ; for none of the more northern forms were discovered by him. Yet the presence of the same geological horizon in 8. India was placed beyond a doubt. (Pal. Ind. 1873, Cret. Fauna, vol. iv. 3, ser. 8, 3.) In 1880 the trigonometrical survey having been completed, and a first-class map of the Lower Narbada valley having been published, the Geological Survey of the district was seriously entered upon, the work of Blanford and Wynne being the basis. Mr. Bose was ordered to pay especial attention to the fossiliferous strata and the igneous rocks. The results of this survey were published in the Memoirs of the Geological Survey of India, vol. xxi. pt. i., * Mem. Geol. Surv. India, vi., ; see also Blanford, Geol. Bombay, Records Geol. Survey India, vol. v. pt. 3, 1872, p. 82. + Quart. Journ. Geol. Soc. vol. xxiii. p. 38, and vol. xxv. p. 44 (1869). CRETACEOUS STRATA OF THE LOWER NARBADA REGION, 151 1884, by P. N. Bose, B.Sc. (Lond.), F.G.S. Mr. Bose collected fossils in abundance, from the Nodular limestone, the Argillaceous limestone or marl, and also from the Coralline limestone. He found an Ostrea-bed on the top of the sandstone mentioned by Blan- ford, and his paleontological researches and stratigraphical results led him to adopt the following views :— The age of the Sandstone is not settled, but the Ostrea on the top he believes to be O. Leymerii, d’Orb.; it is Neocomian in Europe. The Nodular limestone rests conformably upon the Ostrea-bed and the Sandstone, and some of the same Ostrew are found in diminishing numbersinit. The Nodular strata Mr. Bose assigns to the Gault in one part of his work, and to the Albian and part of the Cenomanian in another. The Argillaceous limestone rests conformably upon the Nodular series, and contains the species formerly described in Quart. Journ. Geol. Soc. 1865, which were collected by Captain Keatinge. To this horizon Mr. Bose gives the correct names of Cenomanian with part Turonian. The Coralline limestone rests upon the Argil- laceous limestone conformably, and after an examination of its fauna, Mr. Bose decides that it is Senonian in age. Mr. Bose, I regret to state, writes about the determinations of the species having been made by him “ roughly ;” and it became evident, after studying his memoir, that there were not sufficient grounds for believing that the whole Cretaceous formation was represented in about 80 feet of conformable strata, the whole of the series from the Gault or Albian, to the Senonian inclusive, following conformably upon a Neocomian. As Mr. Bose recognized some of the Echinoidea I had noticed, and as there was a good collection made from all the horizons, ex- cept the so-called Neocomian, I applied to Mr. Medlicott for the loan of the Echinoidea, with a view of describing them in the Records of the Geological Survey of India. Mr. Medlicott sent me the collection, as also one made by Mr. Blanford many years before, and that of Captain Keatinge, which had been placed in the Museum at Calcutta. The fossils in the Museum at Calcutta which had been collected many years ago by Captain Keatinge, came from the Argillaceous limestone or marl, and therefore were from the same strata as those which had been studied by mein 1865. Unfortunately this little group of well-preserved specimens was not studied by the last surveyor of the Cretaceous rocks, nor does it appear that he made himself acquainted with the forms which had been collected by Mr. Blanford. But Mr. Bose found some species in the collection which he made, and which I had not seenin the marl. Jn order to arrive at the truth with regard to the Echinoidea, I re-examined the collection in the Museum of this Society, and found that only one species required further consideration. It appeared to me that although the general shape of the EHchinobrissus warranted the specific name I had given it, the details of the ambulacra were insufficiently seen. These details are well shown on a specimen which Mr. Bose obtained from the same horizon, and there is no difficulty in recognizing the petaloid condition of the postero-lateral aS y4 PROF. P. M. DUNCAN ON THE ECHINOIDEA OF THE ambulacra which characterizes Cotteau’s Echinobrissus Goybeti from the Cenomanian of the Lebanon. I do not propose to alter the determinations of any of the other species of Echinoidea and Mollusca. The late Mr. Davidson was good enough to determine the Brachiopod to be Rhynchonella depressa, Sow., and this common Upper-Greensand species was found accum- panied by a coral, Thamnastrea decipiens, Mich., from the same horizon. The commonest species in the collection in our Museum is Henuaster cenomanensis, Cott., and the only apparent distinction between the type from the French Cenomanian and the forms from the Bag beds is that the posterior ambulacra in the specimens from India are not quite so broad as the others. All the specific characters are present. Henuaster similis, d’Orb.,.is not uncommon, and two specimens are in our smali collection. The identity of the French and Indian species struck’me very forcibly, and the species is really a very distinguishable one. Hence the former determinations hold good except in one instance, and the necessary alteration strengthens the view of the Upper-Greensand horizon of the beds which yielded the fossils, or rather, as I put it, of the existence at Bag of a horizon from the top of the Gault to the base of the Chalk with flints. The collection from the Museum at Calcutta was then investigated. The first fossil examined was an exquisite Salenza, belonging to the group with very narrow ambulacra, and which has the two vertical rows of ambulacral primary tubercles so closely placed that there is no room for more than an occasional granule between them, in fact to the “‘ petalifera” or “ scutigera” group. The apical disk of the Indian form is ornamented with ridges and furrows in the usual radiating manner. But the species is not a new one, for it was recognized and described by the industrious and exact M. Cotteau in the collection obtained by Fraas in the Lebanon. Cotteau called it Salenia Fraasi, and it was found, in the first instance, in the Cenomanian deposits of the Lebanon. (‘ Ech. nouy. ou peu connus,’ 2° sér. fasc. 4, 1885, p. 59, pl. 8. figs. 1-5.) There are numerous specimens of a Cyphosoma in the collection, and they are readily to be identified with the well-characterized Cyphosoma cenomanensis, Cotteau, from the French Cenomanian, The other specimens are Hemiaster cenomanensis and similis. Mr. Blanford’s collection was from the marl near Dussai, 15 miles west of Mandoo, and many specimens came from the Coralline limestone at Chirakhan. The specimens which could be named belonged to Hemuaster cenomanensis and H. similis. Hence Mr. Blanford has given us the evidence that there is a community of species between the marl and the overlying and conformable Coralline limestone. Mr. Bose’s collection from the marl was next examined. The two Hemiasters were found and also the Cyphosoma already men- tioned. The Echinobrissus is named, according to Mr. Bose, on my authority, but I did not see it until a few weeks ago. Mr. Bose, however, gave me the opportunity, when I examined his specimen, CRETACEOUS STRATA OF THE LOWER NARBADA REGION. 153 of correcting my former determination ; and the species is Echino- brissus Gor ybeti, Cott., from the Cenomanian of the Lebanon. Several fairly well-preserved parts of a Cidaris were collected by Mr. Bose, and one or two belonging to the same species had been collected by Captain Keatinge and placed in the Calcutta Museum. These Mr. Bose considers to belong to Cidaris cenomanensis, Cotteau ; but there are well-marked specific distinctions present, although the narrow ambulacra have four rows of interporiferous granules and the median suture is sunken in the interradia. The excessive size and irregularity of the warty granules beyond the scrobicular circles, and the proximity and large secondaries of these last- mentioned structures, are sufficient to separate the species, and, moreover, the Indian form is a large one. Mr. Bose was quite right in placing the form near to C. cenomanensis. It has been necessary to establish a new species for the form Cidaris nama- dicus, nob.* An Orthopsis was found and recognized by Mr. Bose, and he appears to consider that it is O. similis, Stol., described from the Arrialur strata of S. India. But there are specific differences; the Bag form has two of the radial plates not entering the periproctal ring, and the numerous rows of primaries do not extend so far up above the ambitus as in Stoliczka’s species. ‘The other supposed specimens of Orthopsis collected by Mr. Bose belong to the genus Cyphosoma. It will have been observed that the Argillaceous limestone has a very interesting fauna, and it appears that Nucleolites similis also occurs as a variety, and this species of d’Orbigny brings the beds into relation with the Chloritic Marl of Europe. The Hchinoidea of the underlying Nodular limestone were next examined, and only two species could be identified from Mr. Bose’s Saivction, and they are common. They are the two Hemiasters, H. cenomanensis and H. similis, the commonest forms in the con- formable marl above. There are no Gault or Albian species present, and there are no stratigraphical data which will permit of the division of the few feet of beds into a Gault or Albian and a Cenomanian. The Coralline limestone, which is above and conformable to the Argillaceous limestone, contains the following species :—Cidaris namadicus, nob., which also occurs in the Argillaceous beds below ; Cyphosoma cenomanense, which has a similar vertical distribution ; Nucleolites similis, var., Weenie rer cenomanensis, and H. similis: all these are met with in the limestone below, and the two Hemiasters are also found in the Nodular limestone. Messrs. Blanford and Wynne, and also Messrs. Medlicott and Blantord, in the ‘ Geology of India,’ considered that the Nodular limestones, the marl, and the Coralline limestones belonged to a con- formable group, with a fauna indicating one Cretaceous horizon, and the examination of the collections of Echinoidea proves that these views are correct. The age of the Ostrea-bed at the base of the Nodular limestone * About to be described in the Records of the Geol. Survey of India. Q.J.G.8. No. 170. M 154 PROF. P. M. DUNCAN ON THE ECHINOTDEA OF THE is not considered in this communication ; for the specimens have not been examined in Kurope. The following is a list of the species of Echinoidea found in the Cretaceous series of the Lower Narbadd Valley :— | | Nodular ieee | Name. | Lime- | Marl. ie : Foreign. | stone Li ee LE (ebb ors a ie Sd Cidaris namadicus, sp. nov....... ee aL ase Nalenta) HraastColt-aceskeeeee-- UL eae Lebanon, Cenomanian. Cyphosoma cenomanense, Coit. we % | % France, [santrs Cenomanian. Orthopsis indicus, sp. nov....... Se ae) on nee ye eee Echinobrissus Goybeti, Coz. ... Me Se valli Lebanon, | Cenomanian. Nucleolites similis, d’ Orb., var. | * | % Europe, Ch. | Marl. Hemiaster cenomanensis, Co77. * 3 alee France, | Cenomanian. Hemiaster similis, d’Orb.......... ¥ aise France, | | Cenomanian. Discusston. Prof. Acassiz complimented Dr. Duncan on the work he had done on Echinoderms for the Geological Survey of India. Mr. StapEen considered it was undesirable that paleontological . work should be criticized by any one who had not studied the actual materials upon which it was based. From his personal acquaint- ance with Dr. Duncan’s extensive knowledge of the Echinoidea, he had full confidence in accepting the important deductions which the Author had laid before the Society. Dr. BianForD explained the circumstances under which the hurried survey made by Mr. Wynne and himself was carried on around Bag in the month of May, the hottest season of the year; it was consequently not surprising that some of the conclusions had to be modified. On the other hand, he had already suspected that the paleontological evidence adduced by Mr. Bose in favour of referring the three limestone beds and the underlying sandstone to four dis- tinct stages of the Cretaceous system was insufficient, and he was not surprised to learn that Prof. Duncan had AOE. Mr. Bose’s views to be untenable. The most interesting point was the additional evidence of the great difference between the fauna of Bag on the one hand, and that of Trichinopoly of the same age on the other, the former being Euro- pean, the latter containing a small percentage only of European forms. This supported the view already urged by the speaker that in Cre- taceous times a land-barrier extended from India to South Africa. Mr. WairakeEr said that in west Norfolk the whole of the beds from CRETACEOUS STRATA OF THE LOWER NARBADA REGION. 155 Lower Greensand and Middle to Upper Chalk were to be found within 80 feet of vertical distance. Dr. Duncan, in reply, said that the statement in the Memoir of the Geological Survey of India was, that the series from the Lower Green- sand to the Upper Chalk inclusive was comprehended in 80 feet. In the English example there is a great difference between the fossils of the various strata; this is not the case in the Bag beds. mM 2 156 MR. R. LYDEKKER ON DINOSAURIAN VERTEBRZ 11. On certain DrnosavRIAN VERTEBRZ from the Cretaceous of Inp1a and the Istm or Wicut. By R. Lyprxxenr, Esq., B.A., F.G.8., &e. (Read January 12, 1887.) tw the year 1877 I published * a preliminary description of certain Dinosaurian remains obtained from the Lameta group of the Jabalpur district of India, to which I applied the name of Titano- saurus indicus. The Lameta beds, it may be observed, have been usually referred to the Middle Cretaceous (Upper Greensand), but later observations indicate that they may be of somewhat newer age. The remains on which the genus was founded are preserved in the Indian Museum, Calcutta, and comprise an imperfect femur, and a considerable number of late caudal vertebrae, together with one imperfect vertebral centrum from an earlier part of the series. In a later memoir t I gave figures of some of the more important of these specimens, and came to the conclusion that the vertebre in- dicated two species, for the second of which I proposed the name of T. Blanfordi, adding the proviso that this form might eventually turn out to be generically distinct from 7’. indicus. Both these types of late caudal vertebre are characterized by their strongly proccelous centra, to the anterior half of which the anchylosed neural arch is confined ; and in the one perfect specimen of 7’. indicus the arch carries two well-marked processes, one of which is directed anteriorly and the other posteriorly. The pre- axial process is bifureated anteriorly, and bears a pair of prezy- gapophysial facets; while the hinder one, which (judging from the caudal vertebree of the Sperm-Whale and of certain other Dinosaurs) I think includes the representative of the neural spine #, is single, and carries the postzygapophyses. In 7. indicus the hemal aspect of the bone presents two pairs of V-shaped ridges, on the extremities of each of which are a pair of well-defined facets for the attach- ment of chevron-bones, which look directly downwards ; while the centrum is relatively short, with its hemal surface placed nearly at right angles to the lateral surfaces and characterized by its extreme lateral compression. In the form to which the name 7. Blanfordi has been applied the centrum is larger and subcylindrical, and the hemal and lateral surfaces are not distinctly differentiated from one another, the ridges on the former surface are not present, and the facets for chevron-bones are either very indistinct or totally wanting. These two types of vertebree appeared to me to come nearest to those of Cetiosaurus and the so-called Pelorosaurus of the English * Rec. Geol. Surv. Ind. vol. x. p. 38 (1877). One of the specimens had been previously described and figured (without name) in Falconer’s ‘Paleontological Memoirs,’ vol, i. p. 418, pl. xxxiv. figs. 3-5. tT ‘Paleontologia Indica’ (Mem. Geol. Surv. Ind.), ser. 4, vol. i. pt. 8, p. 20, pls. iv. & v. (1879). { Many writers adopt a different view in describing analogous specimens. FROM INDIA AND THE ISLE OF WIGHT. 157 Wealden, in which the centra are amphicclous; and also to those of the much smaller Macrurosaurus * from the Cambridge Greensand, in which there is a slight proccelous. character in some parts of the series, and distinct facets for chevron-bones are wanting. ‘Their extreme proccelous character seemed, however, so peculiar that at a later date + I thought myself justified in assigning Tvéanosaurus to a new family of the Sauropoda. Thus the matter stood till some few months ago, when Mr. W. Davies, of the British Museum, directed my attention to two vertebral centra in the Collection under his charge, which had been obtained by the late Mr. Fox from the Wealden clay of Brook in the Isle of Wight. These centra, as Mr. Davies pointed out to me, agree in general characters with those of Tvtanosaurus, and almost certainly belonged to a closely allied form. ‘The least imper- fect of the two specimens, which is figured (with the neural arch restored) in the ascompanying woodcut, comprises the whole of the Caudal vertebra of a Dinosaur, with the neural arch restored ; from the Wealden of Brook, Isle of Wight. 4% nat. size. British Museum (No. R. 151). centrum and the base of the anchylosed neural arch. The two extremities are somewhat rolled and water-worn, and have thereby lost somewhat of their original roundness ; but in general contour, as well as in size, in the form of the articular surfaces, in the position of the base of the neural arch, and the apparent absence of distinct facets for chevron-bones, this specimen agrees very closely with the centrum of Titanosaurus Blanfordi represented in pl. v. fig. 3 of the memoir in the ‘ Palaontologica Indica’ which has been already * Seeley, Quart. Journ. Geol. Soc. vol. xxxii. p. 440 (1876). ae Indica, ser. 4, vol. i, Introductory Observations, p. v 158 MR. R. LYDEKKER ON DINOSAURIAN VERTEDRE quoted. The centrum is, however, more compressed in the English specimen, while the hemal and lateral surfaces are distinctly _ differentiated from one another, and the former surface carries a pair of V-shaped ridges resembling those of 7. indicus. The specimen is in fact very nearly intermediate in character between the figured vertebre of 7. Blanfordi and T. wmdicus. The abrasion of the rim of the articular cup shows that the internal structure of the bone is coarsely cancellous. ‘The second specimen (No. R. 146 a) comprises the anterior half of the centrum of a slightly smaller vertebra, and has been but little rolled. This specimen shows on the ventral aspect the well-marked V-shaped ridges so well displayed in the type specimen of 7. indicus*, but lacks the distinct chevron-facets of that form. We may then, I think, consider it most probable that the English specimens indicate the occurrence in the Wealden of a Dinosaur closely allied to Tvtanosaurus; and it now remains to consider whether, in the first place, they can be referred to any genus already described from those beds, and, in the second place, whether or not they should be regarded as generically identical with one or both of the Indian forms provisionally included in the above- mentioned genus. With regard to the first question, among the large Dinosaurs of the Wealden the caudal vertebrae of Jgwanodon and its allies are of a totally different type from the present specimens; while equally different are those of Cetcosaurus (with which may be grouped the so-called Pelorosaurus), as well as those of Megalosawrus, in both of which genera the centra have either flattened or slightly hollowed articular surfaces. Turning, however, to the gigantic Ornithopsis, we find that the caudal vertebra have not been hitherto known 7, and there is accordingly a strong prima facie presumption that the specimens under consideration may belong to that genus. The nearest allies to Ornithopsis are certain North-American Dinosaurs included in Marsh’s Sauropoda t, such as Brontosaurus, Morosaurus, Camarasaurus, Amphicoclas, &c.; in these, while’ the precaudal vertebra have cavities in the centrum like those of Orm- thopsis, those of the caudal region are solid. Apparently in all the American forms the centra of the caudal vertebre are amphiccelous, while those of the cervical region are opisthoccelous; since, how- ever, in some genera, such as Camarasaurus §, the dorsal vertebre are opisthoccelous, like those of Ornithopsis, while in others, like Amphicchas ||, they are amphicclous, there is apparently no reason why similar variations should not also occurin the caudal region of other members of the group. In Brontosaurus, where * Palseontologia Indica, ser. 4, vol. i. pt. 3, pl. iv. fig. 1. Tt See Hulke, Quart. Journ. Geol. Soc. vol. xxxvi. p. 36. There apparently is no reason why the amphiccelian vertebra there mentioned should not belong to Cetiosaurus, since they agree closely with the specimens from the Great | Oolite figured in Phillips’s ‘ Geology of Oxford.’ t See Marsh, ‘Amer. Journ.’ vol. xxiii. p. 83 (1882), and vol. xxvii. p. 167 1884). § Proc. Amer, Phil. Soc., Dec. 21, 1877, p. 237. || Ibid. p. 243. FROM INDIA AND THE ISLE OF WIGHT. 159 the dorsal vertebre are amphiccelous, Professor Marsh’s * figure and description show that the hinder caudals have neural arches of the precise type of those of Titanosaurus, while the form of the middle part of their centra is apparently very similar to that of the specimens under consideration. In Camarasaurus, again, the centra are laterally compressed as in Z%tanosaurus imdicus, although the facets tor the chevrons are less strongly marked. Camarasaurus and Amphicelias, it may be observed, are of Cretaceous, while Brontosaurus is of Jurassic age. The suborder Sauropoda is taken to include Cetosawrus, which, although none of the vertebral centra are hollowed, is evidently allied to Orni- thopsis; while it is probable, judging from the structure of the caudal vertebre, that Macrurosaurus should also be placed in the same division. There appears therefore to be at least a consider- able degree of probability that the Wealden vertebre may belong to Ornithopsis; and if they do not it is pretty certain that they do not belong to any other previously known English genus. With regard to the second question—+. e. whether these vertebre, which may be provisionally reterred to Ornithopsis, are generically identical with one or both of the two forms described under the name of Titanosaurus—there is far less possibility of arriving at present at any very satisfactory conclusion. It will, however, be safe to say that if the characters which distinguish the vertebra of Trtanosaurus imdicus from those of 7. Blanfordi eventually prove to be of not more then specific value, then the English vertebre might well be also generically identical, in which case Titanosaurus should be merged in Ornithopsis. If, however, on the other hand, the vertebree described under the name of 7’. Blanfordi should turn out (as it is highly likely that they will) to be generically distinct from 7’. indicus, then there would also be very considerable probability that the Wealden specimens are likewise generically distinct from both the Indian forms, although their relationship appears nearest to the form called 7’. Blanfordi. Under these difficult circumstances the only prudent course is to consider that we have evidence in India and Kurope of three appa- rently closely allied Dinosaurs clearly marked off from all other described forms by their strongly proccelous later caudal vertebra, and for the present to retain the generic name T%tanosaurus for the type Indian species, to refer the Wealden form provisionally to Ornithopsis, and to leave it open whether the form to which the name Titanosaurus Blanfordi has been applied is generically iden- - tical with one or other or even both of these forms, or whether it should form the type of a third genus 7. In conclusion, it may be observed that the occurrence in the * Amer. Journ. vol. xxvi. pl. i. (1883), and vol. xxi. p. 420 (1881). t In my description of Titanosawrus T mentioned a larger vertebral centrum which I regarded as precaudal and proccelous. Since, however, similar vertebrae, which are opisthoccelous, occur at Brook, the two types may respectively belong to the early caudal region of the Indian and European Dinosaurs, as the Crocodilia and Macrurosaurus show that the form of the articular surfaces of the centra may vary in different parts of the caudal region. 160 MB. R. LYDEKKER ON DINOSAURIAN VERTEBRA. higher Cretaceous of India of two species of Dinosaurs apparently closely allied to one from the lowest Cretaceous of Hurope seems to be another instance of the survival in India of allied or identical generic types to a date after they had disappeared from Hurope. A somewhat similar instance is afforded by the occurrence of Mega- losaurus in the Arridlur group (white chalk) of Trichincpoly in Southern India *—that genus being mainly characteristic of the Wealden and Stonesfield Slate, although lingering on to the Maestricht beds y—and also by the oft-quoted Siwalik fauna. I may also observe that if the Wealden vertebre really belong to Ornithopsis, then we shall have good evidence of the distinctness of that genus from the North-American Camarasaurus, with which it has been identified by some writers—a distinction which might, I think, justify the reference of the English genus, together with Titanosaurus, to a separate family, the Ornithopside. Finally, I may express a hope that the Officers of the Geological Survey of India will direct their attention to the acquisition, from the Lametas of Pisdura, of other remains of Dinosaurs which may include vertebree of the precaudal region, and thus indicate the true relationship of Titanosaurus to Ornithopsis. Discussion. Prof. Skerry regretted the absence of the Author. The vertebra on which Titanosaurus was founded had long been known in Eng- land, but was considered insufficient to enable the relations of the animal to be determined. The femur had not been figured. The characters of the vertebre were insufficient to show that there was any affinity to Cetiosaurus, and Pelorosawrus was only a species of Cetiosaurus. The speaker considered that the vertebra from the Isle of Wight were also insufficient for identification. ‘The facets supposed to be those for the attachment of chevron-bones looked for- ward and outward, so that it was very questionable whether they were facets at all. The affiliation to Ornithopsis rested on insufficient evidence. There was more similarity with Macrurosaurus, but the centrum in that genus is cylindrical. Although a large portion of the caudal region of the vertebral column of Macrurosaurus was known, its affinities were very doubtiul. Mr. Hutxe concurred with the Author in thinking that the close similarity of the Indian and the Isle-of-Wight vertebrae: warranted the assumption of a generic, if not specific identity. He had never (nor, he believed, had Mr. Fox) found these vertebra in the beds hitherto yielding the remains of Ornithopsis, and he was in- clined to regard their reference to this Dinosaur only as provisional, the view taken, he understood, by the Author. * Palzontologia Indica, ser. 4, vol. 1. pt. 2, p. 26. t Vide Seeley, Quart, Journ, Geol. Soc. vol, xxxix. p. 246 (1883). MR. R. LYDEKKER ON A MOLAR OF A PLIOCENE EQUUS. 161 12. On a Motar of a Puiocenz Typr of Equus from Nusra. By R. Lyprexxer, Esq., B.A., F.G.8., &. (Read December 15, 1886.) A smAti collection of mammalian remains, obtained during the late Soudan expedition by Brigade-Surgeon Archer at Wadi Halfa and other places in Nubia, has been submitted to my notice by Dr. Woodward. Many of the specimens are evidently of comparatively recent origin; but those from Wadi Halfa are in much the same mineral condition as the bones from the Upper Pliocene of the Val d’Arno in Tuscany, or the Lower Pleistocene of the Narbada valley in India. Among these remains are several specimens belonging to a large species of Bos or allied genus, which do not admit of any attempt at specific determination ; but they also com- prise an upper molar of an Hquus, which is of very considerable interest. It may be well to recall that so long ago as 1865 the late Dr. Falconer described, in the Society’s Journal*, part of the left maxilla of a Hippopotamus obtained from fluviatile beds at Kalabshi (Kalabshee or Kaldbsheh), a village situated on the Nile a short distance above the first cataract at Assouan, and about 150 miles north of Wadi Halfa, which is at the second, or great cataract. Dr. Falconer referred his specimen, which he observed was in the same state of mineralization as the Val d’Arno fossils, to the existing H. amphibius, although remarking that it agreed in size with the teeth of the Pliocene Val d’Arno form, which at that time was regarded as specifically distinct. The specimen forming the subject of the present communication (figured from the crown-surface in the accompanying woodcut) BEES yp é os 5 « . ANN S . ¥ e@)))) VA IS YY \\ Wii, HEN } \Y HR Wy ~} oN \ BY ti Sy A , f } \\ UMM, (7 A nf iN A \ \\ i Ns iW | PY gi) WA WN RF ff WW Bh \ NAS) b= KB \ \ DQ k \ y Equus, sp. A right upper cheek-tooth (? m.1), from the Upper Tertiary of the Nile valley at Wadi Halfa. 4. e¢ anterior, and / posterior inner pillar. consists of a right upper cheek-tooth, which, from its comparatively small size, is probably the first or second of the true molar series, * Quart. Journ. Geol. Soc. vol. xii. p. 873. See also the writer's ‘Catalogue Gigssy Fossil Mammalia in the British Museum,’ part ii. p. 279, No. 40855 5). 162 MR. R. LYDEKKER ON A MOLAR OF A PLIOCENE EQUUS. and is in a comparatively early stage of wear. The small antero- posterior diameter of the anterior inner pillar (¢), and especially the slight production of the part of this pillar placed posteriorly to the “ neck,” or point of junction with the main body of the crown, indi- cates that the specimen does not belong to any of the later Pleistocene or resent species of the genus, but to that more generalized group comprising Lf. sivalensis of the Pliocene of India, and LH. Stenonis of the Upper Pliocene of the Val d Arno and Algeria and of the Norfolk Forest-bed*. With regard to the upper cheek-teeth of those two forms, which Dr. Forsyth-Majory regards as identical, 1t appears that in the former the crown-surface of the antero-internal pillar is on the average decidedly more elongated than in the latter t, and that it has a greater tendency to the production of its anterior extremity in advance of the “neck,” in which respects it makes an approach to E. quaggoides, F.-Major §, and is thereby connected with the recent species of the genus. Now in the form and connexions of the pillar in question the Nubian tooth agrees so exactly with the Indian species (being, indeed, absolutely undistingnishable from the first true molar of the maxilla of the opposite side represented in pl. xiv. fig. 2 of the ‘ Paleontologia Indica,’ ser. 10, vol. ii.) that, if found in India, it would be unhesitatingly referred to that species. When, however, we call to mind the apparent impossibility of distinguishing many of the existing species of the genus by their teeth alone, it would be rash to say that the Nubian fossil belonged to #. swalensis; and it will accordingly be advisable to regard it as apparently indicating the occurrence in that region of a species belonging to the same group, and also as affording pretty conclusive evidence that the ossiferous beds of Wadi Halfa, and probably, therefore, those of Kalabshi, are either of Lowest Pleistocene or of Upper Pliocene age, since this group of horses, both in Kurope and Algeria, and in India is unknown after the period of the Norfolk Forest-bed, which is either lowest Pleistocene or highest Pliocene. The specimen is, however, of interest from another point of view. I have previously expressed an opinion || that the modern African genera, found in the Pliocene of India, may have reached Africa by way of the Gulf of Aden; and it is therefore of especial interest to find in the Tertiary of Nubia a member of the primitive,group of the genus Hquus, which is apparently more nearly allied to the Siwalik than to the Huropean species. ‘The occurrence of Hippo- potamus amphibius in the same deposits indicates, however, that the early fauna of this part of Africa was also connected with that of Pliocene and Pleistocene Europe, although this connexion was, perhaps, not so close as in Algeria, where we find in the Pliocene * See ‘ Cat. Foss. Mamm. Brit. Mus.’ pt. iii. p. 71 (1886). T Quart. Journ. Geol. Soe. vol. xJi. p. 2 (1885). ¢t Compare the figures given by the writer in the ‘ Paleontologia Indica,’ ser. 10, vol. ii. pl. xiv., with those given by Forsyth-Major in his ‘‘ Geschichte der fossilen Pferde, etc.” (Abh. schwz. pal. Ges.), pls. i., i1. § Op. cit. pl. ui. fig. 1. || Quart. Journ. Geol. Soc. vol. xlii. p. 175 (1886). 4 MR. R. LYDEKKER ON A MOLAR OF A PLIOCENE EQUUS. 163 teeth which are undoubtedly referable to Hqwus Stenonis accompanied by others which not improbably belong to Elephas meridionalis*. Tf further collections of mammalian remains should eventually reach us from the valley of the Upper Nile, I think we may con- fidently expect that they will afford important information with regard to the relations of the Pliocene faunas of India and Europe with the existing fauna of Africa. [P.S.—The observations of Drs. Woodward and Blanford men- tioned below, in regard to the remains of Deer from the Wadi Halia beds, lend support to the view taken above as to the comparative antiquity of those deposits. | Discussion. The Prestpent remarked that all the materials for the evening’s work had been supplied from the British Museum (Natural History). Dr. Woopwarp spoke of remains of Deer and Bos which appeared to be in the same mineralized condition as those of Equus; they were well-fossilized bones from high above the present Nile level, and were probably of Tertiary age. Dr. Bianrorp spoke of the occurrence of fossil Deer in Nubia as ex- traordinary, since the true Deer now only occur in North Africa, none east of the Sahara, where the Deer are replaced by Antelopes. The link shown with Indian Tertiaries wasimportant. ‘The fact recently ascertained by Mr. Lydekker that true Baboons existed in Pliocene Siwalik beds and even later, showed a resemblance between the Indian and African faunas. All this pointed to a different distri- bution of land during the late Tertiary period in the Persian Gulf and Straits of Bab-el-mandeb. Signs of depression may even now be seen in the former. Dr. Hicxs pointed to the three stages of development shown in the drawings of teeth exhibited, and asked, why do we find a higher form in association with a lower ? Mr. K. T. Newzon remarked on the little that was known of fossils from that part of Africa, and thought the Deer-antler alluded to by Dr. Woodward even more interesting than the Horse’s tooth. The teeth of the Recent and Pleistocene Horses were extremely difficult tosdistinguish, and he thought the tooth exhibited might haye belonged to one of the existing African species. Was there any other evidence as to the probable age of the beds? ‘The Deer would seem to indicate earlier beds than could be inferred from the presence of the Horse. Dr. Woopwarp observed that the remains came from different deposits, but the piece of Deer’s antler was certainly associated with the tooth of Horse. The Prusrpent said that amongst some remains brought from the Soudan was a tooth decided to have been that of a very large Antelope. * See ‘ Cat. Foss. Mamm. Brit. Mus,’ pt. iv. p. 108 (1886). 164. MR. R. LYDEKKER ON A MOLAR OF A PLIOCENE EQUUS. The Avrnor, in reply, remarked that Hquus Stenonis, in Algeria, is associated with the remains of Deer. ££. Stenonis is intermediate between Hipparion and H. caballus ; but it is impossible at present to say where the evolution connecting these forms took place. He concluded that the evidence was in favour of the species being one of those which disappeared towards the close of the Pliocene period. ee —— ——— ———— aan MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. 165 & 13. The Terracszs of Roromanana, N.Z. By Jostan Martin, Esq., F.G.S., Auckland, N.Z. (Read February 9, 1887.) Tue destruction, by explosion connected with the eruption of Tarawera, 10th June, 1886, of the world-renowned Terraces of Rotomahana invests with a melancholy interest the subject of this paper. A calamity so complete and overwhelming that not a vestige of these magnificent monuments of Nature’s architecture remains to mark their site, has called forth expressions of sincere regret, not merely from the inhabitants of New Zealand, but also from every student of Nature’s phenomena, every lover of the picturesque and beautiful, as well as from every casual visitor to this wonderful district. As the chief centre of attraction to tourists through the Hot-Lake district, the Terraces of Rotomahana have been frequently described. Poets, men of science, and historians have endeavoured to express in varied language the impressions which these unique structures have produced upon them, while painting and photography have made known to some extent their delicacy of colour and variety of form. Most of the writers have, however, admitted their inability to give, from a rapid survey of the whole, more than a brief and incomplete description. In fact nothing beyond a generalized or vague idea could be acquired, except by a prolonged residence on the spot, a close familiarity with the place in all its varying aspects, a continuous study of the marvellous range of phenomena, and an intimate acquaintance with and patient observation of their periodicity and more salient characteristics. The largest and most important structure, but lately so well known as the White Terrace, was of very recent geological formation. lts origin, the Terata Geyser, was situated in a crater-like hollow near the centre of a conical hill of steaming and partially decom- posed felspathic tuff on the south-east side of the warm lake Roto- mahana. Outspreading fan-like from its cauldron, 100 feet above the lake, and descending by terraced steps of white sinter in a sector of 60° to a broad fiat of indurated mud, it encroached upon the lake with a wide sweeping curve measuring 800 feet (see fig. p. 167). The distance from the apex to the frontage was equal to a radius - of 800 feet, and the measurement gives an area of about 320,000 square feet or about 72 acres. The Terrace was divided by marked differences of structure and elevation into :—- 1. The Upper Terrace, with its long horizontal lines of cups steaming and overflowing with hot water. 2. The Middle Terrace, with its massive steps and shaggy fringes without basins or receptacles for the overtiow. 3. The Lower Plateau, a series of shallow basins and wide level 7 platforms. 166 MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. Measurements along a line of radius from the lake to the summit gave the following results :— | | Radial cae Hlevation. Average. eee ee ft. Bes (AE Miake-fatwe ecameunnss cose 80 1 or 1 in 80} 60° to 80° | | Bowe” 42, Lower plateau ........ 66 | 4— 3°5'or 1 in 16] 80° to 90° eau. | , \ 3. Cold-water Basins...... 150: {10= 3°5' or 1 in 15) 60° to 90° Middle {4. Tabular masses and Terrace. slopes) 540.0 t waeeneet 240 |50=11°5’orlin 5) 80° to 112° Weeer 5. Hot-water Basins ...... 250) \35=" 7° wor tans isto 1608 Men |g Upper platform ...... 30 Level 160° to 170° The Great Cauldron, or Basin, when empty, appeared to be an extensive excavation lined, decorated and richly ornamented with the characteristic deposit of snow-white sinter. Its form was elliptical, with a longer diameter of 200 feet and a shorter of 165 feet. ‘ The sides of the Cauldron formed a nearly vertical wall 10 feet high, which extended about halfway round on the east side, the other portion sloping inward at an average angle of 50° to a depth of about 20 feet, except under the “ Lion Rock,” where a magnificent cornice overhung a perpendicular wall 14 feet in height. ’ he basin-floor was broken into large irregular masses, the whole surface being roughly corrugated into wavy lines (probably caused by convection-currents) and presenting the appearance of wind- drifted snow. The Cauldron was enclosed by a smoothed and perfectly level rim of silica, about 6 feet in average width. This enclosing rim formed a pathway round the Cauldron, except on the south side, where its continuity was broken for a distance of | 40 feet, being perforated by a number of small steam-holes. The crater-walls, excavated from the hill by hydrothermal action, rose abrupt and dark from the outer circumference of the rim. i From 50 feet in height behind the Cauldron this wall sloped, |~ as it embraced the hollow, to the sharp ridges which formed the side | of the entrance, and, with the ‘ Lion Rock,” probably, at an earlier | period, completed the circuit at a height of from 12 tc 15 feet above | the level of its recent overflow. The opening to the upper platform in front of the Cauldron | MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. 167 extended 123 feet, and near the middle stood the “ Lion Rock,” a mass of harder material (which had resisted disintegration), 35 feet in length at its base and 10 feet in height. This encroached con- siderably within the elliptical area of the Cauldron, rendering its surface reniform in contour. Sketch Plan and Section of the White Terrace, Rotomahana, in November 1885. NeLLsoa9 $$$ rare en RY SEN = - te Lake Rotomahana. The opening to the Tunnel was situated about 30 feet to the south-west of the centre of the basin, at a depth of 30 feet below the rim; it measured 15 feet across, narrowing at a further depth of 8 feet into a tube apparently 6 feet in diameter. ‘The activity of the Geyser varied greatly. From furious ebullition with a rushing overflow fully 10 inches in depth across the whole opening, it would subside into its normal discharge, welling up and 168 MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA, over in ripples of about one inch in depth: frequently the overflow would cease, fluctuations continuing within the basin; and occasionally the water retired altogether within the tube, leaving the basin dry. During rapid alternations of activity and rest the whole contents of the Cauldron have been observed to retire within the tube in six hours, and the most rapid refilling noticed has taken four hours to complete. The process of refilling sometimes commenced slowly and was continued steadily, while at other times the action would be spas- modic, and violent eruptions of water wouid be thrown to an enormous height, sometimes failing beyond the area of the basin. From the measurements taken of the interior of the Cauldron, its capacity would be about 24 million gallons. From numerous and independent observations the activity for 100 days may be stated as :— days. 1, Excessive.—Violent disturbances, basin filling in 4 hours with overflow of 600,000 gallons per hour ............ 2 2. Extraordinary.—Basin filling in from 6 to 12 hours, overflow from 200,000 to 400,000 gallons per hour ............ re) 3. Normal.—Constant ebullition in basin, dense steam-clouds, frequent geyser-fountains from 20 to 30 feet above surface, water welling over in rippling waves at 100,000 gallons per hour ys -..0 Ae eed HON sae Le ae ee a 75 4, Feeble——Reduced geyser-action, water rising and falling with the basin, Jitle or mo overtlow....2 -) seme] 4: 10 5. Quiet.—Water low, showing floor of basin .............. 3 6. Dry.—Water all retired within the tube..... A ao Vea ige 2 100 Heavy N.E. weather, with falling barometer, was usually associated with excessive action; the water frequently retired, leaving the basin dry, when the wind was from the south, with a. clear sky and rising barometer. Closely comparing the movement of the aneroid with the period- icity of action gave, however, very unsatisfactory results. For three days the activity of the Geyser exactly corresponded with the movement of the barometer—overflow ceasing and the water retiring into the tube when the barometer was rising and wind changing from W. to §8., and activity being resumed directly the barometer indicated a downward tendency and the wind shifted toward N.E. On three following days similar changes of activity took place under exactly opposite conditions as to wind and barometric pressure. During six days succeeding the overflow continued normal, although similar atmospheric changes were experienced. — —————=~ en ee —————— z ue ———— —— MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA, 169 An approximate analysis of the water gave about 150 grains of solid matter per gallon, viz. :— ers. Siliea, free and combined with soda uu... . ee ees cccecesccesevecees 50 Sodium and potassium chlorides...............ccccesesceeseeeteeees 60 PeMamIC CCRT Hy SOAS 65. doo cae ci. o Sede so nctenedunseic vaaseatianasedex 30 Sadie sulphate, and other salts, :-.........c.:sceceeecsesecctecees 10 150 The amount of rock material thus withdrawn in solution by this geyser at its normal rate of discharge would amount to about ten tons per day. Several observations lead to the conclusion that at least ten per cent. of the silica would be deposited upon the surface covered by the overflow. This would be equivalent to about 120 tons per year, and give an average deposit over the entire surface of one inch in fifteen years. Upon the upper portions of the structure the deposit had formed as rapidly as one inch in five years upon various objects placed for experiment in the course of the overflow. The Upper Platform extended east and west in front of the basin for 130 feet. Its width at the west end was 15 feet, and at the east 10 feet. In front toward the centre it opened out into two large shallow basins. The larger (No. 2 on plan) circular in outline with a diameter of 60 feet, the other (No. 3) semicircular, with a curious double outer rim, had a radius of 20 feet, and between them was a slightly depressed channel 4 feet wide. The outer (eastern) portion of the platform was very curiously broken into miniature lakes and islands, with peninsular points and crescented bays. The surfaces of the elevations were smooth, and of uniform level with the rest of the platform and rim of Cauldron (No. 1). These small depressicns, as well as the hollows of the two basins (Nos. 2 & 3), had the nearly uniform depth of twelve inches. The sides of the elevations and the floor of the depressions were covered with delicate coral-like deposits of exquisite beauty. When the platform was covered by the overflow, these numerous and beautiful depressions escaped notice, the whole surface appearing as a level sheet of water, the visitor being cautiously conducted along the narrow path in front of the rock over which the water would be rippling from the Cauldron. The double outer rim of No. 3 basin enclosed a deep and beauti- fully ornamented crescent, a yard in width at the widest part. The sides and depths were covered with projecting and interlacing points of coral-like sinter, similar in character and disposition to the fleecy masses which were scattered over the basin floor and whieh promised in time to fill up the entire cavity. This seemed to afford strong evidence that the crescent as well as the other depressions could not have been excavated by the same ~ agency as that by which they were slowly but certainly filling. The breach or outer wall of this (No. 3) basin formed a wavy semicircle ten yards in extent and about six feet in height, thickly set with rough projecting bosses and mammillary points. Q.J.G.S. No. 170. N 170 MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. The outwork of No. 2 basin formed a massive wall ten feet in height, with similar decorations, and presented a conspicuous appearance when the terrace was viewed from the lower levels. The wondrous horizontal lines of “cups” were situated immediately below, on the west and east points of the Upper Platform, meeting the circular walls of the basins ; joining at their base, these continued the regular parallels right across the front of the Terrace. The tiers or rows of “cups” might be classed in four sections, each with its own specialized structure and form ;— 1. East lines, slope 1 in 8. 2. West lines, slope 1 in 5. 3. Steep basins (central), slope 1 in 3. — 4. Lower series, slope 1 in 10. (1) Upon the upper eastern portion their crisp and sparkling lips projected like open bivalve shells, overhanging half the cup beneath ; seen from below they formed long lines of varying height but perfect in their horizontality ; and in section they would appear as a series of crescents, set with points projecting upwards. (2) On the other portions of the upper slope the projecting rims were reduced and rounded, and formed perpendicular walls with protuberant lips. (3) Under the walls of basins Nos. 2 & 3 these receptacles were steeper and bolder, and formed a series of Decorated Basins, which being a little distance from the beaten track were rarely seen by visitors. Their elevations were curiously embossed and adorned with rosette-like appendages, which, when the Terrace was partially dry, stood out white in bold relief upon a grey ground, and presented: to the spectator a more perfect ideal of rich ornamentation than could be seen elsewhere on any part of this wonderful structure. (4) The lower series of enclosures opened out into wide shallow areas, bounded by low narrow sinuous ridges, almost unnoticed when dry, but strongly defining the differences of elevation when covered by the overflow. When seen full and overflowing from above, these receptacles appeared as segments of azure, outlined with arcs of creamy white, infinite in variety of size, from a semicircle a few inches in diameter, to long and wavy outlines of from 50 or 60 feet, enclosing pools from one to six feet in width, with a few larger areas showing a deeper blue outlined in firmer lines. In this series of ‘“‘cups” the silica was deposited by rapid evapo- ration in a granular form, and when dry had the dazzling bril- liancy of frost-work; yet so firm and adherent were the particles that they were with difficulty crushed or scraped away, the outer rim or edge being more compact than the interior. The upper and lower portions of the. Terrace were distinctly separated by the great wall, popularly known as the Giant Buttress, which extended its level summit in a wavy outline for more than 30 feet, supporting the shallow pools of the Upper Terrace. Its front was draped with overlapping wool-like fringes and stalactitic pen- : | | MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA, db dants, from which the overflow trickled in a glistening shower. This was the most conspicuous portion of the whole structure, the gradual descent of the formation on either side leaving the centre overhanging more than twelve feet above a basin which beautifully reflected its curious architecture. This natural division was also marked by a level path varying in width from 2 to 20 feet, which extended right across the face of the Terrace from east to west, broken only by a few steps near the centre. Upon this belt, and almost exactly in the centre of the Terrace, was the rough protruding rock known from its peculiar shape as the Boar’s Head. A little further towards the east was the Broken Basin, a circular pool 12 feet in diameter, about 26 inches deep, of similar height upon its outer front, the only warm-water basin on the White Terrace deep enough to be used as a bath; its temperature varied, according to the overflow, from 120° to 90°, its interior surface was rough like concrete, and a sedimentary deposit was disturbed when bathing. Some time ago an opening must have been roughly hewn out of the rim, forming a depressed lip about 12 inches across and 4 inches deep, through which the overflow poured into another shallow basin below. The deposition of sinter here must have been very slow, as scratches and markings made in the hollow of the broken lip two years since were barely covered by a thin glaze. The Middle Terrace. The central portion of this part of the structure was distinguished by a series of massive, rugged, and rippled perpendicular elevations, many of which exceeded six feet in height; some were decorated with pendent wool-like fringes, some with deeply engraved parallel lines, and others with small upturned scales. The central ones were approached on either side by lower ridges, which together formed an ascent of about two hundred steps. At increasing distances from the centre, these elevations were again and again reduced until, near the margin, they merged into wide incrusted slopes marked by lines of interlacing ripples which formed protecting ridges less than half an inch in height. These elevations, although presenting the characteristic lines of leyel surface, formed compact platforms, tables, or steps—only one depression occurring in the whole series, and that but a small muddy pool. Although the normal overflow covered the whole of the Terrace, any diminution in quantity left many of these central masses dry. The deposition of silica appeared to be scarcely sufficient to preserve the compact character of the surface, and those parts most exposed to the action of the atmosphere were disintegrating and becoming loose and fragmentary. It seems but reasonable to suppose that these central elevations N 2 172 MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. had been formed before the lateral slopes were cleared of vegetation, as such masses could scarcely have been deposited by aqueous agency if such a free outlet as the sloping sides had been open to the escaping flood. The Hastern Wing of the Terrace, divided from the Middle Terrace by a clump of stout manuka trees, formed a steep slope of sinter deposit rippled into small wavy lines. Under the trees some very nteresting features of new formation were observed, the prostrate branches forming the foundation of ridges, and drifting twigs and leaves collecting in the hollows became incrusted and cemented, forming receptacles similar in character to those upon the Great Terrace. . The Western Wing was separated by a deep cleft and some smaller clumps of bush. Its deposit was similar in character to that of the east wing. Its lower portion was more extensive and formed wide shallow areas, bounded by ridges of from one to three inches in height; these frequently contained beautiful tree-like aceretions, which rising on a stem, spread their branches on the surface, the largest specimens extending over four inches. The Cold-water Basins formed the front extension of the lower central portion of the Terrace. Viewed from above, they exhibited an extraordinary combination of circular and crescented areas, extending from five to twenty feet across, of pale, opalescent blue, outlined by broad rims of grey and brown, with encroaching margins of siliceous mud. From below they formed an ascending series of from one to four feet in height, with rough perpendicular walls, in some instances with a slightly projecting cornice, streaked with vertical lines of white, grey, and brown, mingled with various stains. Their depth appeared to correspond to their height. The surface- water was cloudy from suspended silica, and the basins full of a fine siliceous ooze, gelatinous and cold. The contents of these receptacles showed every stage of consolidation, and many had already become compact tabular blocks. The conversion of the alkaline silicates into carbonates by exposure to the atmosphere would precipitate the silica in the forms observed in these basins. The outward trend of every curve in this wonderful series, and the gradual descent from the apex or summit, seems to indicate their origin from the great cauldron above. ‘The theory of the formation of the structure from siliceous deposition only fails to account for the erection of such regular basins at such a distance from the source, the cooled overflow leaving here so little surface-deposit; and further the excavation of the basin-hollows could scarcely have been effected by the same agency as that by which they were now con- solidating. The Lower Plateau skirting the Terrace on the lake-border marked by its regular gradations the gradual lowering of the lake-level through a distance of about four feet. Along the edge of the Terrace it formed a sinter pavement, loose and fragmentary, readily detached in surface-layers of about an inch in thickness. In many | | | Se as As =— — anne MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA, 173 places it was broken through by clumps of trees or small shrubs, and many rush-covered patches appeared on the softer parts. Towards the lake the margin became uncertain and treacherous, and the boundary between terrace-deposit and lake-mud was unde- fined. Changes in Appearance. The want of a series of systematic observations of the rate and form of deposit can never be supplied. Comparing photographs and notes taken in 1883 with experiences two years later, it was found that marked changes were taking place upon the upper part of the Terrace. The surface previously covered by an acicular deposit had now a more granular character, and instead of crunching under foot like hoar-frost, it had the yielding nature of a layer of snow. The overflow had also worn a slightly depressed channel, leading from the cauldron across the platform, between the two shallow upper basins already described. The flood rising to the lip of the cauldron flowed through this channel and poured down the centre of the Terrace. The erosion of this stream was evidently deepening its own channel and smoothing the surface of those masses over which it poured, while it threatened in time to alter the whole appearance of the Upper Terrace. As the water rose more rapidly than it could escape by this new channel, it next filled the circular outer basin (No. 2), and then the other large area (No. 3); a further rise spread over the western end of the platform and down the trees on that side, the receptacles on the east side being supplied by a cooler stream overflowing from the basin (No. 3). This change of direction from that of the previously charac- teristic uniform overflow was also apparent in the orange coloration which was extending over the eastern tiers, probably due to con- ferve. The temperature of the water in these depressions was only 100°, while in those at the same level on the western sideit was 30° warmer. Before attempting an explanation of the peculiar architecture of the Terrace, it will be necessary to take into account the enor- mous amount of material removed from the hill in excavating the crater and cauldron; from careful measurements this cannot be estimated at less than 23 million cubic feet, an amount equal to a deposit of eight feet in thickness over the entire area of the Terrace. This detritus must either have been carried away with the overflow into the lake or deposited upon the hill-slopes. Observing that the erosive action of the overflow was cutting a channel through the hard siliceous pavement of the upper platform, the torrent would certainly have opened a gorge through the soft rock, if in its initial form the Terata Geyser had exhibited similar characteristics to those with which we have been familiar. Or had its earlier activity been more feeble and intermittent, the 174 MR, J. MARTIN ON THE TERRACES OF ROTOMAHANA, overflow would have spread its surface-deposits over the face of the hill, as exhibited in the sinter formations of other hot springs in the district. It also appears quite evident that the siliceous lining of the great cauldron could not have been deposited until the process of excava- tion was nearly complete, and that the solid precipitous walls, the comparatively level floor, and the perfectly level encircling rim must have acquired stability of form before the deposition of silica upon their surface. The extension of the platform in front of the cauldron and the massive walls and basins which characterize the structure suggest to the careful observer the probability that their formation was due to the deposit, in a plastic condition, of the material thus removed from the crater. The phenomena of mud volcanoes exhibited at the plateau of Rotokanapanapa afford to the geologist valuable indications of the probable appearance of the Terata cauldron in the earlier stages of its activity. This circular area, of similar size to the crater of the White Terrace, was situated in a hollow of the same hill, a few chains further towards the west, where the continued or intermit- tent action of steam escaping through felspathic tuff had gradually converted the rock into a perfectly level Jake of mud and clay. The surface was covered with a semi-liquid layer from which rose a large number of miniature cones and craters varying in diameter from 2 to 20 feet, the former emitting steam, with occasional spats of mud, the latter bubbling and seething like boiling paste or porridge. Around the edge or outer rim of the area the mud was sufficiently compact to form a firm and safe footpath, while towards the centre it became very soft and hot. Extending through a narrow outlet over the slope towards Rotomahana, the mud overflow preserved the same uniformity of level until it fell abruptly over a rounded breastwork which was encroaching upon the vegetation on the hill-side ; the surplus water, thick and creamy at first, deposited its solid matter in hollows and upon obstructions, and finally escaped clear.through the scrub to — the lake. If this condition had been succeeded by a gradual increase of thermal activity, it seems but reasonable to suppose that the softer clays around the centres of action would be slowly removed, to accumulate as masses of deposit upon the slopes below. Inter- mittent discharges of siliceous water would carry forward streams of plastic clay, which on meeting level ground would spread out and form sweeping curves of low elevation; this deposit would rapidly harden, as it dried upon the outer surface, into a cement like concrete; other following deposits resting upon those already laid would form a series of terraced steps. Succeeding streams otf water penetrating through surface-cracks would excavate the still soft and plastic interior and redeposit the solid material thus re- moved, in the form of overhanging lips with pendent or stalac- titic fringes, or as smaller intermediate steps, instances of which MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. 175 can be observed at the white mud craters of Wairakei, near Taupo. The comparative study of local phenomena thus appears to favour the theory that the initial activity of Terata was very similar to that of Rotokanapanapa, and that the successive periods which mark the history of the formation of the White Terrace correspond with the increasing activity of its source. The hill surrounding Terata being pierced by numerous steam- jets, 1t is exceedingly probable that a large number around a common centre originally combined to form a crater-lake of seething mud. As activity increased, the outer wall of the crater would be occa- sionally broken down, and escaping mud-streams would be as frequently liberated. These periodical overflows would form by superimposition upon the hill-slopes the foundation of this curious and complex terraced series. The earlier streams moving slowly through the vegetation on the hill-side, spread out upon the level ground at the base, forming that beautiful series of curves previously described as the Cold-water Basins. The excavation of these basins would be easily effected, if, after the induration of their outer walls, running water penetrated through surface-cracks before the consolidation of their central mass. The central steeps, which rise immediately above these basins, appear to have been built up by the masses of plastic clay, which issued at successive periods as the wall of the crater yielded to the increasing activity. The upper platform, with its massive circular outworks, would have been formed as the enlargement of the crater-gap increased to its historic dimensions, and the level surface, including that of the encircling rim, indicates a period when this entire area was in a soft and plastic condition. As the eruptive force augmented, and as intermittent geyser- fountains succeeded, the smaller vents within the area would tend _ to unite in one enlarged vertical tube. The argillaceous contents, _ reduced to an exceedingly fine state of subdivision, would by pro- _ longed boiling be removed and replaced by a siliceous cement, the _ more compact encircling rim being left entire around the cauldron. _ he numerous tiers of shallow receptacles known as the Upper | Series, hot-water basins, or ‘cups’ appear to owe their regular out- _ lines to the successive waves of siliceous material which overflowed | periodically during the excavation of the cauldron. Evaporation | would cause this material to harden rapidly from its outer surface, _ and thus the lines of elevation would be maintained when the softer | interior was removed by succeeding currents. Percolation of water _ through the pores would increase the deposit of silica within the interstices of the mass and further harden the basin-walls. Thus | deposition and removal combined to produce that exquisite variety | of form which characterized these horizontal lines of deposition. __ The curious depressions upon the Upper Platform are also readily explained upon the hypothesis that the crust of the upper strata of 176 ° MR. J, MARTIN ON THE TERRACES OF ROTOMAHANA, argillaceous deposit was broken through, and the softer parts of the interior removed. Thermal activity within the cauldron having at length removed the softened rock, the deposition of siliceous incrustation in all its varied forms of elaborate crystalline ornamentation would decorate the foundations previously laid with that enchanting beauty which was the glory of the White Terrace. _ Otukapuaranga, or the Pink Terrace, situated on the opposite side of Rotomahana, about a quarter of a mile further towards the west, had a frontage of 140 feet, and at a distance of 495 feet rose to the - height of 85 feet. Of similar but older formation, and resembling the White Terrace in its essential features, it differed in many important details. The colour from which its name was derived was characteristic only of the older deposits, which a new smooth white enamel was slowly obliterating. There were also numerous indications of diminution in the activity of its source, and of a probable change in the constituents of its overflow. The structure may be considered in four divisions, corresponding to differences in the angle of inclination, viz. :— 1. The Front Plateau. 2, The Middle Terrace. 3. The Upper Platforms. 4, The Basin or Cauldron. (1). The Front Plateau extended as a gentle slope 30 feet wide along the frontage, where it rose abruptly about 2 feet above the lake. The overflow being confined to a central space 45 feet wide, the other portions were partially overgrown with moss and scrub, except at a narrow channel formed on the eastern margin. (2). The Middle Terrace, or Terrace proper, consisted of sixteen well-defined tabular elevations averaging 4 feet in height, ap- proached by numerous subordinate or intermediate steps, reduced on the margins to rippled and irregular cascades, which formed an easy ascent. ; (3). The upper levels, a series of wide, smooth platforms, rising by slight elevations, extended completely across the Upper Terrace, a distance of 224 feet. Here were situated the “ Baths,” a series of eight hot-water basins, which were the only depressions on the Terrace. The Baths were smooth shallow cavities, crescentic in outline, averaging 9 feet by 3 feet, with a depth of from 2 to 3 feet, ranging in temperature, according to distance from the Cauldron, from 90° to 130°. The four principal bathing-pools were situated near the centre on rising grades, with an elevation of one foot, the massive fronts of the upper baths projecting considerably over the basin-area below. _ (4). The Cauldron measured about 159x160 feet, and was MR. J. MARTIN ON THE TERRACES OF ROTOMAHANA. V7 surrounded by a level rim, in width from 5 to 30 feet. The great basin appeared to be always full of deep-blue boiling water, edged with sulphur and enshrouded by a veil of steam. Usually overflowing without agitation, it was occasionally disturbed by wave-lke upheavals. Its margin could only be approached at one part of its circumference, where soundings gave a depth of fifteen feet, and the wall just below the surface was seen set with spiny ridges. Near the centre of the boiling lake was a dome or mass of spongy sinter, which could be seen only when the steam drifted away and the surface was unrufiled. _ By the terrible catastrophe of June 10, 1886, the waters of lakes Rotomakiriri and Rotomahana were drawn into the newly opened fissure, which had originated at the base of Ruawahia or Tarawera, and by the extraordinary explosions which succeeded, the terraces of Rotomahana were blown away, and wide steaming areas of desolation are all that remain to mark the site of these once world- renowned structures, (for the Discussion on this paper, see p. 188.) 178 CAPT. F. W. HUTTON ON THE 14. The Exvrtion of Mount Tarawera. By Captain F. W. Horton, F.G.S. (Read February 9, 1887.) Tae eruption of Mt. Tarawera, in the North Island of New Zealand, took place on the 10th of June, 1886. Iwas not able to leave Christchurch at once, but arrived at Rotorua on the 26th of June. During my stay in the district, which lasted till 14th of July, I exam- ined Rotomahana and Okaro, and went across the Kaingaroa plains to Galatea. Subsequently, with Prof. F. D. Brown and Prof. A. P. Thomas, I visited Lakes Rotoiti and Rotoehu. Description of the District. About 25 miles south-west of Lake Taupo is Ruapehu (fig. 1), a trun- cated cone 9195 feet high, covered with perpetual snow. Until lately it was thought to be extinct, and is so described by Dr. von Hochstetter ; but for several months past steam has occasionally been noticed issuing from the summit, and on the 16th of April last, Mr. L. Cutten, Surveyor, ascended the mountain and found the crater on the top to be 300 feet deep, with hot, eddying, and steaming water Fig. 1.—Sketch Map of the North Island of New Zealand, showing area affected by the Hruption of 10th June, 1886. (Scale 200 miles to 1 inch.) WOODVILLE Ea Be NS ee Tarawera ash. Rotomahana ash. at the bottom, which had melted the snow all round for 40 feet, although about 1U0 feet above the water there was a fringe of ice. ERUPTION OF MOUNT TARAWERA. 179 The next day a large column of steam, 100 feet high, ascended from the crater. No earthquakes are recorded in the neighbourhood during the whole of this time. Between Ruapehu and Taupo lies Tongariro, the principal cone of which, Ngauruhoé, as well as two other smaller cones to the north, constantly emit steam. Ngauruhoe was in active eruption on July 6, 1870. About 130 miles N.N.K. of Tongariro is White Island, or Waikari, in the Bay of Plenty (fig. 1). It isasolfatara, 860 feet high, and sur- rounded by water 1200 feet deep halfa mile fromitsshore. Between them is a zone, 20 or 30 miles broad, abounding in solfataras, mud volcanoes, fumaroles, geysers, and hot springs, which has been ealled the Taupo zone by Dr. von Hochstetter. The scene of the recent eruption is in the centre of this zone, about halfway between Tongariro and White Island. Mt. Tarawera stands on the eastern side of the lake of the same name. It is a flat-topped ridge about three miles long and nearly half a mile broad, surrounded by rocky precipices, rising abruptly from a plateau and sending out a long spur to the north-east, as well as a shorter one to the south. The highest point of the ridge is 3609 feet above the sea and is called Ruawahia; immediately to the north is a col, about 500 feet deep, which separates from the main part of the ridge a smaller and rather lower portion called Wahanga. The southern peak of the ridge, that which looks over Rotomahana, is called Tarawera by the Maories, but it is only one end of the ridge of which Ruawahia is the other, and Europeans generally apply the name Tarawera to the whole mountain, including Wahanga. It presented no appearance of being a recent volcano ; there was no crater on the top, which seems to have undergone extensive denudation; and the Maories have no tradition of its ever having shown signs of activity. Rotomahana was some two or three miles south of Tarawera (fig. 2). It was a shallow lake, about a mile long and a quarter of a mile broad, surrounded by numerous fumaroles and hot springs among which were the famous White and Pink Terraces. It drained into Lake Tarawera by the Kaiwaka stream. Its height above the sea is given by Hochstetter as 1088 feet. A little to the north-east of Rotomahana, under the spur from Mt. Tarawera, was a small lake called Rotomakiriri, on the shores of which were curious, circular crater-rings *, About two and a half miles south-west of Rotoma- hana is another small lake called Okaro ; it lies immediately under Kakaramea, a pointed hill formed of fumarole clays (decomposed rhyolite) from the sides of which steam constantly escapes; but there were no hot springs in Okaro. The rocks found in the district are all volcanic, chiefly rhyolite, which is generally the stony variety called liparite, but occasionally itis vitreous. South of Rotomahana, however, and probably on the southern slopes of Mt. Tarawera, a dark-coloured augite-andesite occurs. Near the hot springs the rocks are all decomposed into soft fumarole clays, white, red, yellow, and grey in colour. * Hochstetter’s ‘ New Zealand,’ p. 419, and figure. 180 CAPT. F. W. HUTTON ON THE Fig. 2.—Map of the country around Tarawera Volcano after the Eruption of 10th June, 1886. (Scale 5 miles to 1 inch.) yi AS: ——— —— SS SO ————— : oO ns oO > Ta S o S ai ms i ! OLaJ p len) 1 B oe E Ss ! an ° 3 Soy af e 1 “ay = 1 oO. rs} = GA S BS H a x See : | 232 S eee esat x 191910 S S 10 4 CD). 2 S ce A 5 lst S Brickyard.-=-—---—— = Bais = ° rs fe) ~ i . o- = a) cs cre} 55 5=| m ) -») re wm o D Abbie tse (s) a | rele : Ss Sp Oa cs, co 28 I oa = aa + a ep we fase oe or ™ Sens sf Fy eieo maeols 68 Wha SS Sy & o) Se ea) SS = ase) moe F loro) o =| oO He soSes m © s S26 oes a aHO* g S ssHe S S & N bs) si8 SS SH m8 S ‘g SS escarpment of Czesar’s Camp at an altitude agreeing with that of the beds at Aldershot; and in Quart. Journ. Geol. Soc. xli. p. 501 he describes the same section, presumably as green sands in the rifle- butts, at the height of 350 feet. This must be an error, as the AND BAGSHOT BEDS OF ALDERSHOT, 439 butts are at 450 feet; and this gives 100 feet above the hill by the Aldershot brickyard, shown in the section (fig. 3), which is capped on the line of the section by some 10 or 20 feet of Lower-Bagshot beds. This 100 feet would bring us into the lower beds of the Middle Bagshot in their natural position, and this disposes of anything unusual in their occurrence at Cesar’s Camp. Coming now to the London Clay in this section, I have already shown how the base of the clay, as proved in the South-Camp and Aldershot-Waterworks borings, agrees with both the proved and measured dip of the Bagshot Beds ; IT will now show that the thickness of the London Clay at the latter place is about the same as that at the South-Camp boring, and at Ash, as I have given it above. This I shall do, since Mr. Irving (Quart. Journ. Geol. Soc. vol. xli. p. 507), in his ‘* General Gondlusions,” No. 6d, points to this as a section proving great erosion of the London Clay before the deposition of the Bagshots. Two borings at the Aldershot Waterworks penetrated the London Clay 132 and 134 feet respec- tively. I will take a mean of 133 feet. The mouth of the well is at 250 feet O.D., and the outcrop of the London Clay is at an altitude of about 340 feet, and is 730 yds. N. Now 730 yds. and a dip of 27° N. gives a rise of 110 feet; so we have a total thicknesss of (133+ 90+110)=333 feet, which agrees with the deep boring at South Camp (332 feet), and with the thickness at the South- Western Railway Station at Ash (330 feet). There are two more well-sections which should be mentioned in connexion with this area, namely those given in Geol. Sury. Mem. pp. 445 and 446, as at Aldershot Place. (This I think must be meant for Aldershot Park, as it is called on the 6-inch Survey maps, Aldershot Place being called there ‘“‘ Manor House.” ‘The descrip- tions of the positions and altitudes of the wells agree well with spots in Aldershot Park, but cannot be reconciled with any part of the Manor-House grounds. ) When the depths of London Clay found in these borings, namely 151 fect in one and 66 feet in the other, are plotted in connexion with the thickness of London Clay found at the D Lines, South-Camp well, they are found to give a dip of between 22° and 3° to the N., and a thickness of 330 feet. Thus we get a thickness of London Clay equal to that at Alder- shot Waterworks, South Camp, and Ash, and a dip of the strata intermediate in amount between Aldershot and Ash, between which two places Aldershot Park occupies a nearly central position. The Reading Beds with 76 feet are also of about the usual thickness. Coming now to Cxsar’s Camp and the Long Valley, there is but little of importance besides the occurrence of the green sands at altitudes of from 500 to 550 feet and even higher. The Middle- Bagshot beds can be traced all across the valley, rennin occasionally by Upper-Bagshot sands, with their uppermost limit marked here and there by the pebble-bed. So far, each section has been discussed to see to what extent it bears out the hypothesis of a constant northerly dip of the beds. I will now shortly describe a section taken from North to South, across the 440 MR, H. G. LYONS ON THE LONDON CLAY Long Valley by the Farnborough and Farnham Road. In this section we get the high ground at the south instead of the north end of the section, which is more convenient for our present purpose. On the tops of the ridges north of the Red Church, near the Permanent Barracks, the pebble-bed occurs at the top of the Middle Bagshot; and a scarped face of one of these ridges nearest to the Red Church shows a section of the base of the green clayey sands and the top of the clay-beds which form the base of the Middle series. Here, when freshly cut, a dip of about 23° north was shown. Going south, Lower-Bagshot sands were shown ina small excavation by the Queen’s Pavilion, and again in a sand-pit behind the Lock Hospital, where there are about 20 feet of brown and buff false- bedded sands, and seams of pipe-clay are seen, having a dip of 24° north. Further on, at Windy Gap, on Hungry Hill, the same sands are seen, while the London Clay is dug in a small brickyard at the foot of the hill to the east. Hungry Hill itself is capped by a considerable thickness of gravel, and below it small springs are thrown out in wet weather, I think by part of the clay-beds which form the base of the Middle Bagshot. Quite lately, a well 62 feet deep has been sunk at the Inn on the Farnham Road by Hungry Hill, and reached clay having all the characters of the top of the London Clay, having passed through buff and brown loamy and sandy beds. ‘There are 4 feet of water in it. In extending the drains above the Reservoirs in Bourley Bottom, a bed of green clayey sand was cut into, overlain by a brown loamy clay. This green bed is the one which furnishes all the springs which fill the Reservoirs, and is, I think, the middle bed of the Middle Bagshots, which supplies nearly all the wells in and about Aldershot. The point where it was exposed was between 560 and 570 feet above O.D., under Cesar’s Camp and Bricksbury Hill. The sand is dark green when first dug out, but becomes light on exposure to the atmosphere. From these considerations I think that the London Clay and Bagshot beds at Aldershot have a constant northerly dip, and that the Bagshot beds lie conformably on the older beds, which have at this point an average thickness of 335 feet. In conclusion I will briefly recapitulate the points I have drawn attention to in this paper, and their bearing on the stratigraphy of the district. Commencing with the London Clay, I have howe that wherever we can fix the top or base of this formation, we get a dip to the north of from 27° to 3°; and that this dip, if we restore the portions which have been removed by subaerial erosion, gives us a fairly constant thickness of from 330 to 340 feet. In the table below are given the thicknesses of the London Clay at several places in and near Aldershot; and wherever I have restored what has been eroded away, I have shown it in this table. The authorities for each section are also given. AND BAGSHOT BEDS OF ALDERSHOT. 441 London Clay. | Bagshot Thickness in feet. Locality of Well. Bade Authority. fa oe Restored. Total. foeamersaeld Park el | vor {| Geol. Surv. Mem. vol. (Near Odiham) ... } =< SHRED | been | CBD ga errs D Limes, South ae : a fere Camp, Aldershot ... } te oa a 332 | This paper. Aldershot Water- ANe. vie works, INO. 1 :..... | ao l [oes MS. letter of Mr. 200 | Whitaker, Dee. 1884. Dito, NOW2 ... 20.0. S60 132 J 332 ~ | Aldershot Park, ae > Geol. Surv. Mem. vol. sid 11 oa } aot LOB RD 1) Bail { iv. p. 445. Ditto, No:.2 ...-..... se 72 260 332 | Ibid. p. 446. Ash-Green Station,| } { Geol. Surv. Mem. vol. Bev Reka... ee 2A ED aes er Ash Grange (Gen. { 300 20 320 : : Hammersley’s).... } sai (about) (about) This paper. { Rev. A. Irving, Geol. Brookwood ......... 1703 371 ve 371 Mag. dee. iii. vol. ii. p. 303. Thus we get a fairly constant thickness of the London Clay from Odiham on the west, to Ash on the east, when it thickens to the east at Brookwood. Moreover, besides the passage from the London Clay up into the Bagshot beds, at the Wellington-College well (Rev. A. Irving, Quart. Journ. Geol. Soc. xli. p. 506), similar passages are shown in the Brookwood well and in the one at D Lines, South Camp, Alder- shot; so at these points there can have been no great erosion or ereat unconformability. The overlying Bagshot Beds too, as I have endeavoured to show, lie conformably on the London Clay and on one another so far as Aldershot is concerned; and the exposure of the Lower London Tertiaries to denuding agencies in Bagshot times cannot have been so near the Bagshot area as Aldershot. DIscuUssION. The Prustpent congratulated the Society on the acquisition of a recruit whose carefully plotted sections did credit to his training as an officer of the Royal Engineers. Mr. Irvine observed that the Author had the advantage of being stationed at Aldershot, and expressed a hope that this was merely an earnest of future work on the part of one in whom he could not 442 THE LONDON CLAY AND BAGSHOT BEDS OF ALDERSHOT. fail to take an interest. In consequence of the overwhelming evi- dence obtained by Lieut. Lyons he accepted his conclusions and gave up his own hypothesis with respect to the section on Redan Hill &e. He had verified Mr. Lyons’s reading of that section, and observed that the clays of the Middle Bagshots constituted the most persistent hori- zon. Where there is a full normal development of London Clay we have a passage into the Lower Bagshots. He was not quite prepared to accept the calculation of 330 feet from the thickness of the London Clay at the Aldershot waterworks. He regretted that we seem no further advanced as to the age of the Kingsclere axis. Mr. Wuiraxer complimented Mr. Irving on having frankly ac- knowledged his error when it was shown that he had been mistaken. It would, however, be a gratification to him that the correction had come from a former pupil. It was scarcely to be expected that pebble-beds should be persistent over any area; but it was often a matter of surprise how certain thin beds occurred for long dis- tances. He always felt under obligations to those who would correct errors of detail, and hoped that this hint might not be lost upon other officers. Mr. Monckton expressed his obligations to Mr. Lyons, whose paper, in the main, confirmed the work of Mr. Herries and himself. One of their endeavours had been to ascertain if there existed reliable physical differences between the Upper and Lower Bagshots. In this he considered that they had been successful. The Lower Bagshots are characterized by the presence of beds or layers of pipeciay, by abundance of false-bedding, and an absence of shells ; in the Upper Bagshots there is no false-bedding, an absence of pipe- clay, and usually casts of shells. Applying these tests to the Thorn-Hill—Redan-Hill section, the results were the same as those arrived at from a surveyor’s point of view. ‘This work had been admirably done. The clay at the top of Redan Hill had not before been noticed. Mr. Hupirston remarked that, since there was no opposition to Mr. Lyons’s reading of the district, 1t was unnecessary to say any- thing more in corroboration of a most excellent and original paper. Mr. Hnurrtss justified the account of the Thorn-Hiull section given by himself and Mr. Monckton, and observed that the clay on Redan Hill was not exposed at the time their paper was written. He had found Upper-Bagshot fossils in Beacon Hill, and also in abun- dance on the steeple-chase course in the large outlier to the north, thus confirming the Survey mapping. Mr. Lyons, in reply, cordially acknowledged the advantages he had derived from Mr. Irving’s training. Referring to the thick- ness of the London Clay at the Aldershot waterworks, he showed in detail how the thickness of 330 feet was obtained, and argued for the correctness of his estimate. The extent of the Pebble-bed was most remarkable, and the Geological Survey mapping was good, although the boundaries might require to be altered alittle. As regards the passage-beds in the well-section, he did not speak with certainty. ON THE WALTON-COMMON SECTION. 443 32. SUPPLEMENTARY Nore on the Watton-Common Section. By W. H. Houptzston, Esq., M.A., F.R.S., Sec.G.8. (Read April 27, 1887.) . Recapitulation of some points in the previous paper. Continuation section. . Composition of No. 4 Bagshots. Remainder of the cutting. . The Brick-earth of Hatch. . Its probable Geological Position. .- Conclusion. STD OB CO DD THERE seems to be so much uncertainty as to the character of the basal beds of the Lower Bagshots in the London Basin that any opportunity which affords us unmistakable evidence of their real nature should be seized without delay. We have had so much theorizing, based upon the evidence of well-sections and of limited exposures, that we turn with pleasure to a good continuous section like the one which has lately been disclosed between Walton and Weybridge on the London and South-Western Railway. The main features of the Lower Bagshot series in this section, at its actual junction with the London Clay, were very fully described by me in a communication made to the Society last year. Whether we regard the junction there shown as evidence of an unconformity or otherwise, the fact of a complete lithological change is patent to all. 1. RECAPITULATION OF SOME POINTS IN THE PREVIOUS PAPER. Resting immediately upon the grey-coloured and sticky London Clay, distinguished by its fine and perfectly regular bedding, is a sharp yellow sand full of current-bedding. This yellow sand I dubbed ‘No. 1 Bagshots.” Then follows the first clay series, which I called No. 2, or the “ Blue Bagshots.” It is surmounted by a second sandy series, referred to in my previous paper as “ No. 3 Bagshots.” As far as the new cutting for the widening of the line had then progressed, there was no reason to suppose that No. 3 was succeeded by a second clay series, beyond the fact that the line is rather wet thereabouts. For some reason the contracter left this piece unexcavated, and even now (end of March 1887) this portion has not been fully excavated, so that there are one or two points which cannot be ascertained by actual observation. The previous sections (Q. J. G. 8. May 1886, pp. 148, 157) refer entirely to Walton Common. The one on p. 148 is merely a gene- ralized section of the portion of the cutting then under description, whilst the details of the Lower Bagshot beds given on p. 157 are not continued to the end. Hence the section now offered (fig. 1, p. 445) must be fitted on to the west end of the generalized section, which gives no details of the Lower Bagshot Beds, but merely represents their position with reference to the London Clay and Plateau-gravel. 444 MR. W. H. HUDLESTON ON THE The generalized section serves to show how deeply the Bagshots are cut into, there being no less than three places where No. 3 is cut through to the level of the line. The spot where the old section actually terminates is a few yards to the westward of the third gap, where the plateau-gravel is of very great thickness. 2. ContInvATiIon Section (fig. 1). It is now proposed to carry the original section 300 yards further to the westward. The east end of the new section (fig. 1) coincides with the boundary between Walton Common and Oatlands Park. For the space of 45 yards or thereabouts the pale buff sands of No. 3 Bagshots may be traced beneath the immense thickness of plateau-gravel. When last seen (about the point indicated by the arrow in fig. 1) this sandy series is strongly current-bedded, with a false dip of 7° towards the west. Then occurs a kind of hiatus where nothing is seen but portions of plateau-gravel. Yet a little further on and the clays of No. 4 are well seen on the bank-side, and very soon at least 12 ft. of these beds can be measured on the slope. The actual junction with the presumably underlying No. 3 series 1s nowhere visible by reason of the extensive denudation which the clay series has undergone towards its outcrop. But evidence of the former extension of the clay series in this direction may be seen in the clayey nature of portions of the material com- posing the so-called plateau-gravel at this point (m in fig. 1). Altogether the evidence is very much in favour of the clay series resting upon the sandy series, and not passing into it by a process of lateral change, as is stated to be sometimes the case. And there is an additional proof of the truth of this view, that for some distance beyond gap No. 4 the line remains quite dry, as though the argillaceous series, so visible on the slope, did not extend quite down to the level of the permanent way. Presently the effects of the clay begin to be felt upon the line, and throughout the remainder of the section the unballasted portion is a perfect quagmire. The influence of this clay is felt upon the line considerably further than the section extends, owing to the impermeable surface throwing out all the water which percolates the overlying loose sandy series (No. 5). There is an appearance in the upper part of the clay which seems to indicate erosion previous to the deposition of the overlying sandy series (No. 5); but this is doubtful, and in the present state of the section it is impossible to clear up that doubt. 3. Composition oF No. 4 Bagsuors. Towards the east end thin seams of a pale-coloured loam, resembling the so-called pipe-clay, form the upper part ofthe series, alternating with brownish sands, which are rather coarser in the grain than those of No. 3. Lower down these seams are observed to be thicker and the clays less bleached. As we proceed westwards the blue beds (4") occupy the slope, and the greater part may be described asa ; ji | WALTON-COMMON SECTION, 2 RI Ine w heex : WWaWtil@s eons Wey WN ® gi fe2a9 Hallie tose. Sale oO fact z. on Be oO Heel ee poos “bel oF i 95 1} 4 \\ A] 7O WH He Ni eeeie ee => Fs Bilin peter Oo oO . : reg Fo.2 a Ha Ww Ny ea "0,0 Eee bd INVeeo'filtse st leo. mem ro aa s | a (a) =) Ws T1NPV oan JP 2665 oo WIL, 4, Jose mn oo & @w Pe ‘bfg aoe 2S tp B= whey" £5 O.0 B BR o | Bo lillrs 5070 OQ, 09 a 200 ie) 3 | Po oll 07 Sl es NN ene a PS a? eS ellie ~ F5 > g [as or wbeoo [= ae x = Ao ® velit a Coe oD or) ofa" nye) 7) n = Moo ao Bb a oO Rrra alotescs fo) v ° ge —_" ™m ar) IN Dy Wor Oo : i 50-0 lon ct g go 8 or En = Big ao 40,0 for) o & . once fo) jee] MAD i ee \p oo son? rh rs) Qe V2 a\\° spooe TM Z [s) D Ivy ® ay, rast 8 j=) Q \ a er Shoei eat =a Resear S as nS Seoegeal a SO ct, ry 4 Si = S Nea et ed iS oO \2 [e) = pe pos } Sic, =) 2 ce habed Or: 3) pS) — gd Dr. = = ce fo) °fO8 (on) 7 oe B ee S vo of o oe MI Oe we Sh dey e cA 2 ER os) 9 5 oe [keke = = tH 4 i Be OF 2070 ° | S Ose eei = ; a . s enna Gap No. 4. | 5IGSO e £62050 Se NBSS3501059 i Ss @\ a PA NACe - | Pe o230 | tor alt MIQOO"A | = ® Ree | = af Cooomae ® ep do5090/o -_—_ VIC OmZOWB9 | S) Pqore 300% : iso) a\odzee, 2s ( 5 phnasosuco 4 m = Sei oP q > c%O 2; ; CN 2 i £6883 { = BIYDVEO 9 6G 7) > & pron ° { ~~ P08 eaeoe = j BEL Oo : yO whe roe t bo Q.J.G.S. No. 171. YIMY pup uopuory ‘woyoag Uouuog-uoyy A, 942 fO WORDNnUyWOQ—'T “SLT ‘Avmyway Wta9sa {4 446 MR. W. H. HUDLESTON ON THE mass of brown laminated loams with blue centres. This constitutes the main exposure, where sandy intercalations are less frequent. The clay is greasy to the touch and behaves like putty when first handled, yet when dried and pulverized it is found to consist very largely of sand, chiefly quartzose, but with a fair proportion of glauconitic granules. Although tenacious and impermeable to a very high degree, it is doubtful whether these beds would constitute a good brick-earth. On the other hand these loams are much sought for by gardeners, as they are evidently possessed of valuable fertilizing properties. The glauconitic granules are much smaller than those of the Middle Bagshots of St. Anne’s Hill, which I use as a standard of comparison, and the periphery of the individual grains is less smooth. On the other hand there are fewer fractured granules than were noticed in the lower beds. Thus, whilstin a sample from St. Anne’s Hill the grains average 3 millimetre in longer diameter, these grains are certainly less than one fifth. The bluer portions of the beds contain numerous nodular aggregates of sandy pyrites, from 20-50 millim. in length, usually in association with fragments of lignite. 4, REMAINDER OF THE CUTTING. The portion above described was the last excavated, but the widening of the line has been continued as far as Weybridge Station, and the works are now completed between Walton and Weybridge Stations. As far as Haine’s Bridge (mentioned in the previous paper), the series No. 5 maintains its character as fine buff sand with clay laminations, and is not to be distinguished lithologically from No. 3 series. In fact these two series are certainly typical of the Lower Bagshots of this district, and both of them must be of considerable thickness. The base of the clay series No. 4 may be about 40 ft. above the London-Clay surface, but this depends very much upon the behaviour of No. 1, the very false-bedded series. Above No. 5 I have not succeeded in distinguishing any series at present, because, west of Haine’s Bridge, the exposures during the widening were not of a clear nature, owing to the methods of working adopted. Bright yellow fine-grained sands, similar to those so well known between Weybridge Station and the river Wey, are seen for the most part; still it is certain that even in this portion of the cutting there occurs a certain proportion of argillaceous beds. The precise mode of development of these Lower-Bagshot clays could not be ascertained, but I was led to suspect that they form small basins of argillaceous matter in the midst of the sands. The exposures between Haine’s Bridge and Weybridge Station would lie in the very heart of the Lower Bagshots, here estimated by Prestwich at 130 ft. in thickness. 5. Tur Brick-rartH or Hato. Thus far we have felt our way carefully, and the sequence of the Lower Bagshots in the railway-cutting may be regarded as WALTON-COMMON SECTION. 447 settled up to a certain point. Henceforth, if we would further endeavour to study the development of the Lower Bagshots of this part of West Surrey, it will be necessary to take a leap more or less in the dark. We leave the positive for the inferential, and, what is more, we find ourselves in collision with the Geological Survey as represented in their mapping of the ridge known as Woburn Hill between Addlestone and Chertsey (sheet 8 of the solid geology and surface geology of London and environs). This Woburn Hill, or Woburn Park, as it is sometimes called, constitutes a promontory of Bagshot Beds, about 90 ft. above O.D., projecting into the great mass of alluvium and valley-drift at the junction of the Thames and Wey, which takes place about 30 ft.above O.D. The ridge is about two thirds of a mile in length from E.N.E. to W.S.W., and the upper portion is composed of avery stiff clay, which has been worked for a considerable period towards its western extremity at Hatch Farm. This forms a portion of the “clays most extensively deve- loped round Addlestone and Chertsey, where they attain a thickness of 10 to 20 feet,” referred to by Prof. Prestwich * as constituting part of his Middle Bagshot beds. It is not to be denied therefore that the mapping of the Survey in respect to Woburn Hill has the sanction of the great pioneer of Tertiary geology in the London basin. Before proceeding to express my doubts on this point, and also before proceeding in the attempt to define what should be regarded as Middle Bagshots in this part of West Surrey, I propose to give a description of the Hatch-farm Clay-pit (fig. 2,p.448).—The pit is practically a trans- verse section of the west end of the top of Woburn Hill. We perceive at once that the brick-eartl does not occur as an ordinary seam of clay parallel to the underlying sand, but that it occupies a basin-shaped hollow in that sand. There is, in fact, every reason to suppose, from the upward curve of the underlying series, that we simply see the transverse section of a lenticular mass of clay, which on the north is truncated by the escarpment, but towards the south has the appear- ance of going out altogether. Another feature in the brick-earth is the remarkable amount of current-bedding with a prevailing southerly dip, towards the centre of the hollow, in fact ; whilst further soutb, where the hollow in the sand is less pronounced, the laminations are almost horizontal, The clay of this pit is pretty strong, being used for making red bricks and stock bricks, whilst the presumably Middle-Bagshot clays of Ongar Hill, worked by the same proprietor, are also largely used for pipes and tiles. The blue portions of the clay are full of flattened pyzitous lumps of a different shape from those previously noticed in No. 4 of the Oatlands-Park cutting, and there is an abundance of microscopic crystalline aggregates of pyrites and some very fine quartz-grains.- Carbonaceous matter is plentiful throughout, but glauconitic granules are scarce in all examples examined by me. The hill itself forms one of the stiffest clay soils known in this part of the country. *Q. J.G. 8. vol. iii. p. 383. 2H 2 MR, W. H. HUDLESTON ON THE 448 87 feet. above O.D 7 U01}9OS JO OUI] UI YOU {JOM Jo T[JNOUL Jo poAory ‘soytdd yqim Avpo ontq estiep or} wioay skvpoO FNg poyvuruey] oY} SuTpLATp our, ATLog ‘SUIPpeq-os|[V] YIM UOTxeuT0d ur okey] snosdsvUoqavo puv AUOIT ‘JYUSIL OY} UO pULS TIA poppeq -10JUL CLOW PUL [IUOZTIOY oAOUr “|JoT oY UO poppeq-es[ey ATouIETyxe ‘YSTUMOAG “YRIVO-yoIMG oy} JO suotstod poyeurwvy oo ‘(wuNOT) YITLO-YoLtq onyq esueqy *oOT-oL JO YJtou oy] 07 VONLUIPOUT UL svy ¢ yuIod oy] ye Yorya ‘ued stqq uo ATUTeUT st jd OY} Jo 100] ou, ‘ssl YAVe-yorrg oy} yorum uo ‘dog ye urd v ojur summopaey suorjyeuruey Apuvs ul sortoes-AvTQ oY} Jo osvq Suryeppug ‘]]oM OY} Ur poaoad sv owes oy ‘yo {suorjeuluey ALTO [BUOISvODO YITM PULS OFT AA 7007 UL DIDIS 2PIIZLOA Greatest depth of pit 21 feet. CC'O Saoge oof OQ JHoqev oury-wnyeq ‘spied QOT WoTID0g Jo YySue'T) IH wngoy ‘nd-hnjy ming-yowyT wr woyosog—'s “Sq p of the Brick-earth. S Outcro Zi WALTON-COMMON SECTION. 449 6. PRoBABLE GEoLocicaL Position oF THE HatcH BRIcK-EARTH. In attempting to fix the position of this remarkable loam, or brick- earth, we must first arrive at an understanding of what is meant by Middle Bagshots. A casuist might argue, because Prof. Prestwich speaks of the clays between Addlestone and Chertsey as forming the base of the Middle Bagshots, that in point of fact these must belong to the Middle Bagshots, whatever the position of other beds assigned to that seriesmay be. As amere logical crux, there may be something to be said for this view of the case; but geologists will have no difficulty in admitting, if the basal beds of the Middle Bagshots can be shown to occur on a higher horizon in this district, and if such beds have been recognized, both by Prof. Prestwich and the Officers of the Geological Survey, as forming the base of the Middle Bagshots, that in that case we must take the beds usually accepted as the base of the Middle Bagshots for our standpoint, and then see if the Hatch brick-earth or loam can be brought into alignment with them. Along the line of the London and South-Western Railway it is clear, according to the meaning both of Prestwich and the Survey, that the brick-earth (loam) worked on St. George’s Hill forms part of the basal beds of the Middle Bagshots—there 170 ft. above O.D. But the type section must be sought in the cutting on Goldsworthy Hill, where Prof. Prestwich describes the basal beds of the Middle Bagshots as foliated clays, more or less sandy, having a thickness of 14 feet and resting on 130 feet of “* Lower Bagshot Sands.” We are not now discussing the question as to what are the best divisions for the Bagshot series of the London basin taken as a whole. The real issue to be decided at present is whether the Hatch brick- field is in alignment with the basal beds of the Middle Bagshots as defined by Prestwich in the Goldsworthy cutting ; if itis below that horizon it should be mapped as part of the Lower Bagshots notwith- standing its argillaceous character*. J am disposed to think that it does lie below the basal beds thus defined, and moreover that it differs somewhat in character from the basal beds of the Middle Bagshots as seen in the clay-pit on St. George’s Hill. The considerations for determining the point at issue are partly stratigraphical and partly lithological. We must not, I admit, place too much reliance on the latter, considering the variable and uncertain nature of such accumulations. I would merely indicate that the general character of the standard basal clays of the Middle Bagshots is much more regular, there is less of such very accentuated false- bedding, and the material is more frequently of the nature of a pipe- clay. At the same time there are certain well-known features common to all Bagshot clays, such as their loamy and laminated character, abundance of carbonaceous matter, and other conditions, all pointing to considerable similarity in origin. Hence we must * It may perhaps be a legitimate question how far physical peculiarities should determine the mapping of a series. If by Lower Bagshots it is intended to represent sandy beds, and by Middle Bagshots loamy or clayey beds, then Woburn Hill is correctly mapped. But although this arrangement is suitable to the economy of the case it cannot be satisfactory to geologists. 450 MR. W. H. HUDLESTON ON THE not expect the lithological contrasts to be strong or reliable in all cases. The standard basal clays of the Middle Bagshots are nothing more than a repetition on a higher horizon, and over a more extended area, of argillaceous conditions which have obtained from time to time throughout the so-called Lower Bagshots. The stratigraphical aspect of the question, as to the geological position of the Hatch brick-earth, presents more material for our consideration, though I am willing to admit that the evidence presently to be adduced is not absolutely conclusive. Before venturing on a diagrammatic section across country, let me recall one or two facts in connexion with the Clay-pit. The lenticular character of the deposit is obvious. The base may be taken at 60 ft. above O.D. where the mass is thickest, and this is about 25 ft. above the general level of the Thames at Chertsey. There is a well commencing in the underlying sand, the mouth of which is about 75 ft. above O.D. This well is said to be 35 ft. deep, all in sand, and had 9 ft. of water in January 1887. This makes the water-line in that part of Woburn Hill 14 ft. higher than the general level of the Thames at Chertsey. Such indications point to the probability of clay at no great depth from the bottom of the well, since the well can hardly be deep enough to reach the valley- water. At the same time I lay no very great stress upon this conclusion ; first, because the various levels have not been ascer- tained with absolute accuracy, and, secondly, because, in a Bagshot country, the water is often held up so curiously and so capriciously as to make us shy of drawing conclusions therefrom. Leaving the question of water-lines, let us consider how far the general question of levels helps us to fix the position of the Hatch brick-earth. With this object I now venture on a diagrammatic section (fig. 3, p.453). From St. Anne’s Hill to the northern brow of St. George’s Hill is a distance of 5 miles, N.W.-S.H. St. Anne’s Hill is 230 ft. above O.D., and the north brow of St. George’s Hill is 245 ft. above O.D. Woburn Hill is just midway, with an elevation of 92 ft. asamaximum. The position of the recognized basal beds of the Middle Bagshots is very well known on St. George’s Hill, and may be placed at about 170 feet above O.D. ‘The actual position of these same beds at St. Anne’s Hill is not quite so clear; but from general considerations I am disposed to regard this hill*, in its normal and unruined condition, as having the following composition :— * Tt is evident that opinions as regards this hill have varied at different times. It owes its existence to an unusually thick deposit of Bagshot pebble-gravel, which oceurs quite at the top of the hill and presumably at the junction of the Middle and Upper Bagshots. These pebbles are sometimes welded together as a very hard conglomerate, and both this and the loose pebbles have been tumbled about in every possible direction. St. George’s Hill, on the other hand, is quite different in shape, and owes its origin to a strong deposit of the older plateau- ravel. a It is admitted that the fixing of the line of the London Clay on St. Anne’s Hill is somewhat arbitrary, and seems rather opposed to the results of the sinking for water at the Holloway sanatorium (Whitaker, op. cit. p. 66). But as we read of passage-beds (?) into the London Clay, there is evidently an elemen of uncertainty in the Report. | WALTON-COMMON SECTION. 451 : feet Reputed Middle Bagshots.......... ete eran OU) Wongerebasshots )..)).. Akt smile wee eidet aleetiars Sel, 120 Mond omiO lay .5.5 iat UN a ee elect ie 510) otalvabovet Ort aur igo: aap ese ells 230 This calculation brings the base of the Middle Bagshots in St. Anne’s Hill to 170 ft. above O.D.—a level almost identical with that on St. George’s Hill. Making due allowance for errors and mis- calculations, we may safely say that the levels are within 15 ft. of each other. A glance at the diagrammatic section (fig. 3) at once makes us inquire why, if the basal beds of the Middle Bagshots lie so high up on St. George’s Hill and on St. Anne’s Hill, they should have descended so low in Woburn Hill, which lies between the two. In other words, is the mapping of Woburn Hill as Middle Bagshot justified ? The chief point for our consideration is whether there exists any evidence of a trough between St. George’s Hill and St. Anne’s Hill, produced either by an ordinary syncline or by erosion of a pre-Bag- shot surface. If there is no evidence of such a trough, then, on stratigraphical grounds, the Hatch brick-earth must be a member of the Lower Bagshots. JI am quite prepared to admit the existence of some peculiarity hereabouts, because the Thames suddenly changes its mean direction just opposite Woburn Hill, recovers its former course for a few hundred yards, and then suffers final deflec- tion to the E.N.E. The confluence of the Wey and the Thames marks the most southerly point attained by the principal river ; and no doubt the causes which induced and afterwards arrested the southerly course of the Thames are to be sought in the nature and disposition of the beds in this immediate neighbourhood. The Thames was probably drawn southwards by the fall in the London- Clay surface, since it was much easier to eat away the loose sands of the Lower Bagshots than the strong blue clay on which they rest. Hence the most southerly point of the Thames valley probably coincided with the maximum depression of the London-Clay surface on the flanks of the main valley. But the cap of clay on what is now Woburn Hill helped to keep together the incoherent sands beneath ; so that we perceive St. Anne’s Hill, Woburn Hill, and St. George’s Hill are primarily caused by a capping of tenacious material which is of an entirely different nature in each case. We are quite prepared for a synclinal, then, if it can be proved to exist ; but at present [ have not been able to obtain evidence that such is the case, at least not to the extent necessary to bring the Woburn-Hill beds into alignment with the basal beds of the Middle Bagshots. At the same time, there can be no doubt that the fall of the Bagshot base between Walton Common and the River Wey is considerable. Thus at the eastern extremity of the formation in this district, 658 yards west of Walton Station, the Bagshot base is 85 ft. above O.D., whilst near the railway-bridge over the Wey it 452 MR. W. H. HUDLESTON ON THE cannot well exceed 30 ft. above O.D., and may be less. We have, then, a fall of say 55 ft. in 27 miles in a direction from E.N.E. to W.S.W., which serves to show that the London-Clay surface falls at the rate of 1 in 216 throughout the portion traversed by the London and South-Western Railway, between the above-named points. There is also additional evidence that the London-Clay surface continues to fall very slightly still further down the line, since the Bagshot base at Brookwood is 214 ft. below O.D.*. But the above considerations will only slightly affect a line drawn from St. George’s plateau to St. Anne’s Hill (fig. 3), which is nearly at right angles to the direction of the main L. & 8.W. Railway. Hence, we are not entitled to assume the existence of a marked synclinal in the position occupied by Woburn Hill on the evidence above stated ; whilst, on the other hand, if there be no synclinal, the ascertained position of the recognized basal beds of the Middle Bagshots in the district is very much against the notion that the Woburn-Hill Clay (Hatch brick-earth) should be on their horizon. At the same time I am ready to admit that the base of the Ongar- Hili brick-earth, about two miles on the other side of Addlestone, which apparently must be correlated with the recognized basal beds of the Middle Bagshots, cannot be much more than 100 ft. above O.D.; but even this is fully 40 ft. higher than the base of the Hatch brick-earth, and more in the direction where the Bagshot base is undoubtedly falling +. Altogether, it must be considered that if the Hatch brick-earth belongs to the Middle Bagshots, as indicated on the Survey Maps, there must be an exceptional condi- tion of the local stratigraphy. In point of fact we are faced by the following difficulty :—Seeing that the base of this brick-earth is about 60 feet above O.D., and assuming that the Lower Bagshots retain their average thickness of 120 ft., we should have the London- Clay surface 60 ft. below O.D. at this pomt. Itis for those who maintain that this brick-earth belongs to the Middle Bagshots to bring proof of this. Even in the actual valley of the Thames there is no instance that I know of, on the Surrey side, where the London-Clay surface sinks below O.D. At Chertsey, in the heart of the Thames-valley ‘“‘ shingle,” the London-Clay surface does not fall below Ordnance Datum, though it approaches very near it. At the brewery, where the well-mouth is probably 44 ft. above O.D., this happens to be the exact thickness of the superficial beds, thus :— ft. Surface-mould land) loamy clave eis peer 5 Gravel andisamdgessy hye aie s ss oleh @ Avene een 30 Dark said sso reef ac) a vst ok aha eee eee 4 Total of beds above London Clay ........ 44 zt * W. Whitaker, ‘On some Surrey Wells and their Teachings,’ p. 47. t The clay beds at Ongar Hill and the adjacent Row Hill afford a remark- able instance of the development of argillaceous beds in the Bagshot system, which seems to point to considerable variation in their volume and importance even on a well-recognized horizon. { Whitaker, op. civ. p. 49. 453 WALTON-COMMON SECTION. 5. Weybridge Cutting Fig. 3.—Diagrammatic Section from St. George’s Hill to St. Anne’s Hill. (Length of Section 5 miles. Base-line coincides with O.D.) River Wey. Woburn Hill, 92 feet. Chertsey Town, 50 feet. by {j;| ------=——=~———-- eens we eae aso ft © 3000 2000 2v00 +000 5000 AG Vertical Seale, Horizontal Seale. a. Middle Bagshots. b. Lower Bagshots. ec. London Clay. x, Plateau-gravel of St. George’s Hill. y. Pebble-gravel of Bagshot age on St. Anne’s Hill. s. Alluvium and shingle of the Thames Valley and its inlets. Anne’s Hill, 230 feet. St 454 MR. W. H. HUDLESTON ON THE Hence at Chertsey the London-Clay surface almost coincides with the Ordnance Datum. At the junction of the Wey and Thames I have no record, but the well-sinker at Oatlands (Mr. Gray) considers that the ‘* blue clay ” will not be quite so low there as at Chertsey. At West Molesey the London-Clay surface is 7 ft., and at Thames Ditton, 14 ft. above O.D. If these places in the valley of the Thames itself fail to afford a London-Clay surface below O.D., how much less likely is it that the flanks of that valley should do so? Unless there are exceptional circumstances, of which we have no proof, I should be disposed to run the line of junction between the London Clay and the Bagshot beds in Woburn Hill at from 20 to 30 ft. aboveO.D. The effect of this would be to bring the Hatch brick- earth comparatively low down in the Lower Bagshots, and pretty nearly on the horizon of the clays distinguished as No, 4 of the Walton-Oatlands cutting. Not that these two deposits are by any means to be regarded as continuous, since ail the evidence goes to show that clays occur in an irregular and sporadic fashion through- out the sandy beds of the Lower Bagshots. 7. ConcLusion. It may be asked why so much importance should be assigned to the position of these Bagshot clays, or, to put it more plainly, why a particular brick-earth should be relegated to the Lower rather than to the Middle Bagshots. There are two principal answers to this question. rst, that we should not neglect any opportunity of studying the Lower Bagshots of the London Basin, with a view to ascertaining their composition and development throughout the district. The term “‘ Lower Bag- shot Sands,” appled by some people, is thoroughly misleading, as lithological terms usually are in such cases. But altogether apart from the question of nomenclature, there arises a desire to possess a more complete knowledge of these curious beds. ‘The more they are studied under favourable opportunities and without prejudice, the less we shall hear of a passage between a uniform deposit with marine organisms, like the London Clay, and the irregular, current- bedded sands, loams, and clays which constitute the beds usually known as the Lower Bagshots. At present we really know very little of the junctions between the London Clay and the Bagshot Beds; since those of well-sections are not very satisfactory, owing to the different appearance which the same beds are apt to present under a different state of oxidation, and also, in some cases, to the unfitness of those who have to prepare the sectional reports. The second answer to the inquiry, as to the utility of these investigations, is mainly derived from the following consideration, viz.: that, until observers fairly realize the existence of important masses of clay and loam in the division usually known as the Lower Bagshots, we shall be continually finding beds referred to the Middle Bagshots which stratigraphically do not belong to them. WALTON-COMMON SECTION. 455 In this way a species of speculative stratigraphy is encouraged; which has no real foundation except in similar misconceptions. Thus, true progress towards a correct understanding of the history and constitution of the London Basin is retarded. With reference to the subject of mapping, if it is proposed that all argillaceous outcrops shall be coloured as Middle Bagshots, that is a question which must be settled elsewhere. But if this is the view taken by the authorities in charge of these matters, it obviously implies a reclassification of the entire Bagshot system. DiIscussIon,. The Prestpent congratulated the Author on the light he had thrown on the relations of the Eocene beds near Weybridge. He thought that the lenticular character of the beds of this age in both the Hampshire and London basins had been clearly shown. Mr. Wuitaker said Mr. Hudleston’s section of the Hatch-Farm Clay-pit suggested a synclinal, though probably the hollow was one of erosion. The junction of the London Clay and the Bagshot Beds in the Walton-Common section was singularly abrupt; as a rule those formations passed into each other. ‘The term Bagshot Beds was preferable to Bagshot Sands, for the character varied. ‘There was more clay to the west, in the Hampshire Basin, and especially in Dorsetshire. Mr. Irvine gave some details of a section at Highclere to show the transition between London Clay and Bagshot. The section through Woburn Hill, if drawn to true scale, would show the synclinal to be very shallow. The Hatch section appeared to be a mere case of “contemporaneous erosion and filling up.” Mr. Herrres said he had seen no clays in the Bagshot Beds like those of Woburn Hill; but they resembled the basement bed of the Middle Bagshot more than any others. He was, however, in- clined to think Mr. Hudleston’s conclusions were right, but thought judgment should be suspended till the nature of the upper part of the hill was known. It had been said that the chalk surface and the beds above it were irregular ; if so, there might be a local syn- ¢linal here, quite distinct from the general basin-shape of the dis- trict. Again, clay conditions might have set in earlier here, so as to cause a great development of Middle-Bagshot clays at the expense of the sands of the Lower Bagshot. He agreed with Mr. Hudleston’s view of the Walton-Common section. Mr. Hupieston said the suggestion of a great development of Middle Bagshot was difficult to prove or disprove. The curve made by the Thames at this point might, however, be due to a depres- sion of the Bagshots. ‘The presence of passage-beds in a different district, as described by Mr. Irving, did not necessarily throw any light on the conditions prevailing near Weybridge. In some cases the clays of the Lower Bagshots might have been mistaken for London Clay. 456 ON THE WALTON-COMMON SECTION. If the London Clay passed into the Bagshots there was an end to the unconformity for which Mr. Irving contended. Mr. Irvine said, in explanation, that he had only argued that there was unconformity on the margins of the area. The case he had mentioned confirmed the well-sections he had previously quoted. ‘There is no such passage in the surface-sections on the north side. Mr. Hvpieston was glad Mr. Whitaker thought that the Hatch brick-earth on Woburn Hill might be Lower Bagshot, and heartily agreed with his objections to the term Bagshot Sands. ON NEPHELINE-ROCKS IN BRAZIL. 457 33. On NepHELINE-Rocks in Brazin, with SpEcIAL REFERENCE fo the Association of PHonozite and Foyaite. By Orvitre A. Dersy, Esq., F.G.S. (Read June 22, 1887.) THE nepheline-rocks heretofore recognized in Brazilian territory are the phonolites and associated basalts of Fernando Noronha, a deep-sea island off the north-eastern shoulder of the continent, in lat. 3° 5' §., long. 32° 24' 19" W., the volcanic nature of which appears to have been first recognized by Darwin in the ‘ Voyage of the Beagle’*. Recently a single small pebble from the little- known island of Trinidade, in lat. 20° 31'S., long. 29° 19’ W., has come into my hands, showing that phonolite of somewhat different character from that of Fernando Noronha occurs at that place also. Recent investigations have shown that nepheline-rocks of a somewhat different character are also abundantly developed on the mainland, and in such favourable conditions as to throw light on the relations of the granitic type of foyaite or eleolite-syenite to the other members of the group. The localities in which they have thus far been recognized are situated in the Provinces ef Rio de Janeiro, Sao Paulo, and Minas Geraes, and their relative position and relation to the main orographic lines of the region in which they occur are shown in the accompanying sketch map (fig. 1). Three of these localities, Campo Grande, Cabo Frio, and the peak of Tingua, are in the immediate vicinity of Rio de Janeiro, the latter being in the Serra do Mar range, the two former among its foot-hills. Further south another set of localities occurs in the same range in the valley of the river Iguapé. In the Mantiqueira range the peak of Itatiaia (8000 metres high, and the highest mountain of eastern South America) and one or more other high peaks in the neighbourhood are composed of these rocks, which occur also in the Serra do Bocaina, a spur of the Serra do Mar range on the opposite side of the Parahiba valley. The other two localities are the Pocos de Caldas (hot springs), on the southern margin of the great westward expansion of the mountainous area which connects the coast range through the Serra do Canastra with the central range of Goyag, and Itambé in the Serra do Espinhaco range, a northward extending branch of the Mantiqueira. As little more than a year has elapsed since attention was first directed to these rocks, and as the first knowledge of their existence in these different localities was obtained almost casually, it may reasonably be supposed that ———————— , 43 | * A few of the Fernando-Noronha rocks are described by Renard (Bull. de V Acad. de Belgique, iii. 1882). A very complete collection made by Mr. J. C. Branner for the Geological Commission of Brazil has been placed in the hands of Prof. G. H. Williams for study. 458 MR. 0. A. DERBY ON future investigation wili give them a very considerable extension beyond the limits above indicated *. At the Cabo-Frio locality, a rocky island about three miles long and 400 metres high is composed almost exclusively of foyaite of two distinct types, the least abundant of which is referred by Prof. Rosenbusch, who has kindly undertaken a microscopic examination of these rocks, to nepheline-bearing augite-syenite. A single point Fig. 1.—Sketch Map of parts of the Provinces of Rio de Janeiro, Sado Paulo, and Minas Geraes. / THe Picg eT g ve ‘ Bes 720 Gunde == ™ RIO DE JANEIRO LES 200 miles of the island is occupied by a considerable mass of felspathic tuff. The adjoining mainland is composed of gneiss cut by numerous dykes of phonolite, basalt, amphibolite, diabase, and other rocks. A detailed description of this important locality is deferred for a future paper. At the Campo-Grande locality a network of dykes of diabase, phonolite, trachytes, and various kinds of basalt, one of which is limburgite, occur in gneiss in the railway-cuttings. Judging * Since the above was written, I find the occurrence of nepheline basalt reported by Pohlman from Paraguay (‘Neues Jahrbuch,’ 1886, vol. i. p. 244), which makes it probable that the group of rocks here considered will be found alzo in the Brazilian highlands bordering the Paraguay basin. a FRIC NEPHELINE-ROCKS IN BRAZIL. 459 from analogy with other places examined, there should be some- where in the neighbourhood some central mass from which these dykes of phonolite, trachyte, and basalt radiate ; and an examination of the hills in the vicinity will probably reveal such a centre. It is possible, however, that they should be referred to the eruptive mass of the peak of Tingua, which is about 20 miles distant. Here only the lower portion of a single spur has as yet been examined; this is composed of foyaite similar to that of the principal mass of Cabo Frio, resting upon gneiss. That it has not the character of a dyke in the place examined, is proved conclusively by a tunnel some 400 metres long, which has been cut through the spur from side to side. Gneiss, cut by small dykes of basic rocks, occurs throughout the tunnel and for a few metres above its mouth at both ends, but the surface of the spur above the line of the tunnel is occupied exclusively by foyaite. Small dykes of basalt similar to those of Campo Grande and of a trachytic rock occur ; but thus far they have only been seen in the gneiss. The only phonolite seen is in a large boulder or projecting point in the midst of a foyaite area; it presents the appearance of a dyke about two metres wide, with a sharp line of demarcation between it and the foyaite, which adheres to both sides. The phonolite is thickly spotted with inclusions or segregations of foyaite similar to that of the sides, of all sizes up to an inch or more in diameter. The cross sections of these inclusions show a tendency to geometrical forms, appearing like sections of crystals *. The appearance is that of a dyke which had caught up fragments of the enclosing rock ; but the regularity of the distribution of the inclusions and their similarity of form is against this view, while. on the other hand, the phenomena to be described below from the Caldas locality make it seem plausible to suppose that the phonolite is a portion of the original magma that has escaped complete crystallization, and that the inclusions are crystallized segregations in the midst of it. A petrographical study will doubtless determine which view is correct. The great mountain mass of Itatiaia, rising about 2500 metres above its base, is made up for the most part of a variety of foyaite which has more of the granitic aspect than the prevailing rock at Tingua and Cabo Frio, and which has only been met with in a subordinate mass at the latter place, referred, as already stated, to nepheline-bearing augite-syenite by Prof. Rosenbuschy. Foyaite of the ordinary type is also known to occur there, as likewise an aphanitic rock, which may be considered a phonolite or a fine- grained foyaite. As the excursion to this peak was made before my attention was drawn to the group of rocks here considered, many other types doubtless passed unnoticed. The neighbouring * A similar inclusion of foyaite in the phonolite of Fernando Noronha was found in a specimen from that place, when no large masses of foyaite were met with in acareful examination of theisland. Prof. Rosenbusch, to whom a chip was submitted, regards it as an included fragment of an older rock. + A specimen of this rock given to Mr. Henry Bauer, of Iguapé, was sent by him to the late Prof. Lasaulx, who described it in a recent number of the ‘ Sitzungsbericht der niederrheinischen Gesellschaft,’ Bonn. This is the first. published notice of the occurrence of these rocks in Brazil. fy 60 MR. 0. A. DERBY ON peak of Pict is known, from specimens collected in the bed of a stream flowing from it, to contain a variety of types of foyaite and other nepheline-bearing rocks ; and another prominent peak, called Itajubd, in the same vicinity and in the same range is, judging from its topographical features, of similar structure. The Bocaina locality is only known to me by a specimen of foyaite brought from there ‘some years ago by the director of the National Museum when on a botanical excursion. The Iguapé region is only known to me through specimens kindly furnished at various times by a German engineer, Mr. Henry Bauer, who has given considerable attention to the collection and study of the rocks of his district. They include several peculiar types not yet known from other localities; and ‘suspecting that they were associates of foyaite, I requested Mr. Bauer * to search for that rock, which he has recently found at a place called Jacupiranga. Nepheline-bearing rocks also occur in the vicinity of Xiririca further up the valley, and there are reasons for supposing that a number of other localities will be found in that region. The Itambé locality is only known by a specimen in the National Museum of Rio de Janeiro, sent many years ago by the German geologist Eschwege, under the name of diorite, and which is pronounced by Prof. Rosen- busch to be a fine example of nephelinite. A cursory examination of some of the localities above mentioned having shown an apparent and hitherto unsuspected relation between foyaite, phonolite, trachyte, tuff, and certain types of basalt, I determined to visit the Caldas region, from which a specimen intermediate in character between foyaite and phonolite had come into my hands, and where a railway under construction gave unusual facilities for examining this series, while the proximity of a sedimentary formation of paleozoic age gave hopes of ob- taining some idea of its geological age. A splendid development of foyaite, phonolite, and tuff was found associated with several types that have not yet been met with in the other localities. The tephritic basalts which characterize the other places are repre- sented by leucite-basalt and by a peculiar rock having the external aspect of a diabase, in which plagioclase is the predominant element, and which I suspect will prove to be teschenite. Trachytes, if represented, only appear in dykes too much decomposed for accurate determination. The Mogyana railway, starting from Campinas in the province of Sao Paulo, runs near the margin of the mountainous plateau of southern Minas Geraes and the sedimentary plateau of Sao Paulo., The former, composed of gneiss and metamorphic schists, has a mean elevation of from 1000 to 1200 metres; the latter composed of horizontal strata of shale, sandstone, and limestone, cut by numerous and large dykes of diabase, varies in elevation between 600 and 1000 * Among the rocks sent me by Mr. Bauer is olivine-basalt (limburgite). In the other two localities in which it is known (Campo Grande and Tingua) it occurs also in connexion with the group of nepheline rocks here considered, and it may be suspected that the relation is not purely accidental. ——————— ee eS a an NEPHELINE-ROCKS IN BRAZIL. 461 metres, the highest of the denudation-ridges in the part here con- sidered rising to a little over 700 metres. The geological age of this plateau has only in part been determined. The lower beds are soft shales and sandstone with flaggy siliceous limestones, which last are remarkably persistent, having been found across nearly the whole width of the Provinces of Sao Paulo and Parana, a distance of about 300 miles. The limestone has afforded fossil reptiles, wood, and a few unsatisfactory shells, all of which indicate Upper Paleozoic (Carboniferous or Permian) age. The most satisfactory fossils are the silicified woods, which include Lepidodendroids, conifers of the Dadoxylon-type (conifers with a single row of pores also occur), and ferns of the type of Psaronius. Above the limestone come heavy beds of sandstone with intercalations of a melaphyre-like rock, often porphyritic and amygdaloidal, which has not afforded fossils, but is presumably Permian or Triassic. The railway for some distance out from Campinas is at times on the sedimentary series, at times among gneiss hills of the mountainous zone; but after crossing the river Mogyguassu the latter disappear and the main line to Casa Branca follows a flat-topped sedimentary ridge between that river and the Rio Pardo, leaving the Caldas group of mountains, which lies between the head-waters of these two rivers, to the eastward. The Caldas branch runs over the sedimentary series to within about 10 miles of the foot of the mountain, where it disappears, giving way to the gneiss foot-hills. Sedimentary rocks, however, appear in a narrow belt along the foot of the mountain, and it is probable that the interruption above noted is due to the fact that the railway follows the bottom of a valley, and that on the heights on either side the sedimentary strata extend continuously to the mountain. At all events there are no reasons for supposing that the beds at the foot of the mountain belong to a different series from those further away, whose geological age is fixed by the occurrence near Casa Branea of limestones with characteristic fossils. The railway ascends the mountain on one side of the valley of the Corrego (brook) do Quartel, rising in a distance of 18 kilometres from 820 metres at the Prata station to 1270 metres at the summit. The eruptive series begins to appear about 2 kilometres from the foot of the serra in a cutting near the Prata bridge, where a greenish spotted phonolite appears associated with gneiss. Then follow a few low cuttings of sandstone of no special interest. ‘The ascent proper commences with the passage of a narrow gap between magnificent cliffs of sandstone rising about 50 metres above the road-bed. This gap is cut through a narrow ridge set like a wall across the end of the rather broad valley of the Quartel. The sandstone is a very hard fine-grained white rock, broken by joints into small angular fragments, and is very similar in appearance to some of the beds of quartzite (itacolumite) of the metamorphic series, and quite unlike the ordinary sandstones of the sedimentary group above described. That its relations are with this group rather than with the older one is, however, proved by thin beds of soft clay- shales intercalated in it near the base along with a thin layer of od.G.8.. No. 171. Dat 462 MR. O. A. DERBY ON chert, this last being a very characteristic feature of the Carboniferous: series of Sao Paulo. No fossils could be found, and its complete identity with the Carboniferous series could not be satisfactonly established, since it is possible, though not very probable, that two distinct formations in this region may be characterized by cherty layers. If it is distinct I am very strongly of opimion that it will prove to be older rather than newer. The beds are inclined at an angle of 15° to the eastward (away from the mountain), strike N. 20° W. So high an inclination is unusual in the series to which this rock is referred, which, whenever it has been examined, is essen- ially horizontal or with only slight localinclination. As, however, the eruptive activity of this region continued after the sandstone was deposited, the disturbance may be regarded as local. Passing the gap the road bends round and follows the base of the mdge, cuttings in sandstone appearing for a distance of two or three hlo— metres. In some of these the rock is seen to pass into a tuffaceous conglomerate containing pebbles of quarizite, and pebbles and boulders of eruptive rocks. A peculiar feature of this conglomerate is the presence of abundant and oiten large masses of brown mica, which, from its occurrence in masses of considerable thickness and of almost perfect crystallme form, not in detached flakes, must have beer formed in place aiter the coarser material of the rock was deposited. In the cuttings both the sandstone and the conglomerate are con- siderably decomposed, and the contact is not perfectly clear. In one, sandstone is seen above, conglomerate below, with no apparent line of demarcation between them, although the passage from coarse con- glomerate to fine-grained and homogeneous sandstone is an abrupt one. That an actual passage occurs seems to be confirmed by the fact that im the coarser parts of the conglomerate, and near the supposed contact, the cement is extremely quartzose, whereas further away and in the finer portions the eruptive elements predominate — in the cement, and the same rock with its characteristic crystals of mica presents the aspect of an ordinary tuff. The predominant types among the boulders of the conglomerate are two rocks which were not found satisfactorily exposed in situ. One has the external © aspect of a moderately coarse-grained diabase, which, under the — microscope, shows remarkably fresh plagioclase as a predominant element, the other elements being altered beyond recognition by me, and in a manner which I have never seen in any diabase. From — its behaviour with acids it appears to contain nepheline, in which — case it is probably a teschenite. The other rock common in the — boulders seems to me to be a somewhat altered phonolite, but, if so, it is much richer im iron than any undoubted phonolite that I have” examimed. Undoubted specimens of phonolite also appear in the conglomerate. In one of the cuttings in sandstone a dyke of phonolite occurs, — also a dyke of a rock too much decomposed for positive recognition, but which appears to be identical with the diabase-like rock of the boulders. In another cutting in conglomerate there is an inclined NEPHELINE-ROCKS IN BRAZIL. 463 dyke, about 9 metres wide, which is of extreme interest (fig.2). Owing to decomposition, only detached fragments, still 2n situ, of perfectly sound rock could be obtained, those near the margins being typical phonolite, those near the centre foyaite equally typical. Another case of the peripheral development of phonolite as a phase of foyaite will be mentioned hereafter. Fig. 2.—Section of Decomposed Dyke in cutting, Corrego do Quartel. a. Decomposition-nodules of phonolite in decomposed dyke. b. Decomposition-nodules of foyaite in decomposed dyke. ¢. Decomposed micaceous conglomerate. Leaving the sandstone and conglomerate area at an elevation of about 900 metres, whichis presumably about its highest level, the road, while following in general a nearly straight line for about 10 kilometres to the Cascata station, near the summit winds about for a considerable space marked off by lateral valleys, in which the road makes long and sharp bends to the eastward. The extreme points of these bends are marked by the Pinhalzinho culvert, the tunnel and viaduct, the intervening distances being 343 and 2 kilometres. In the U-shaped bends of Pinhalzinho and of the tunnel and viaduct, where the road crossing the lateral valleys enters most into the material of the mountain, nepheline-rocks alone are found, while along the projecting portion of the lower space a dark-coloured basic rock with prominent crystals of pyroxene is exposed in several considerable cuttings. This is in general totally decomposed, showing only rarely, in spots, stony nuclei of a mottled bluish and brownish colour and heavily charged with white zeolites; but in all cases the outlines of the pyroxene-crystals are sufficiently well preserved to serve for its ready identification. In one cutting only, between the tunnel and Pinhalzinho, is the rock perfectly preserved. Two types are here presented: one is a jet-black basalt, which, according to a note kindly furnished me by Prof. Rosenbusch, is a leucitite ; the other is a bluish-black tuffaceous rock containing pebbles up to the size of the first of the leucitite, but as it also contains prominent crystals of pyroxene, the two rocks cannot be distinguished in the decomposed masses. ‘The relations of these basic rocks to the nepheline-series is shown in two cuttings between the tunnel and the viaduct, represented in the annexed sketches (fig. 3). Both rocks are much decomposed, but in spots are sufficiently preserved to make their identification perfectly certain, while owing to the marked difference in colour of the decomposition-products the line of contact is remarkably sharp. I could not make out satisfactorily whether the leucite-rock was originally a basalt or a tuff. The appearance 212 AG64 MR. 0. A. DERBY ON is suggestive of denuded hills of leucite rock buried beneath a flow of phonolite. The former rock occurs in the little valley between the two cuttings, the relative position of which is very much as repre- sented in the figure, so that it is probable that the two masses are connected underneath a capping of phonolite. The peculiar-shaped detached mass in the left-hand figure can hardly be a dyke, and is Fig. 3.—Sections on Railway near Pinhalzinho. a. Decomposed leucite rock. b. Decomposed phonolite. perhaps a fallen boulder enveloped in the phonolite. It is 4 miles wide in the widest part and hes about 20 metres away from the main mass. In the cuttings in leucite rock below Pinhalzinho several dykes, from 2 to 4 metres wide, occur, some of which are evidently of decomposed phonolite, while one, which is better pre- served, although altered to some extent, is either a trachytic rock or a more felspathic phonolite than any elsewhere observed. In the bends of the tunnel and of Pinhalzinho there are considerable cuttings in dark blue phonolite and in a peculiar red rock intimately associated with it. The latter is best preserved at the tunnel; but even there, although the rock is apparently perfectly sound, its brisk effervescence with acid shows that a part of its original con- stituents have been transformed into carbonates. Under the micro- scope, | could make nothing out of it beyond the occurrence of minute dark microlites in a very finely granular ground-mass. In places, dark red glassy crystals of hexagonal outline and irregular whitish spots occur sparingly; both appear to be of secondary origin. Generally the rock appears very homogeneous, but in places thin undulating streaks of lighter and darker red, giving an appearance of fluxion-structure, are seen. In other places there are patches and streaks of bluish and greenish phonolite, which appear to shade off into the red rock without well-defined outlines, such as would be expected if they were foreign inclusions. Patches of included pebbles and boulders with well-defined rounded out- lines are also seen; and two or three large cuttings near Pinhal- zinho are exclusively through a coarse boulder-conglomerate, which is, however, so much decomposed that only on the closest scrutiny can it be distinguished from the ordinary red rock. This con- glomerate is well exposed in a ridge just above the tunnel, inter- calated between two closely adjacent ridges of the red rock, and passed by a cutting about 80 metres long and 15 metres high, in which hundreds of broken boulders with perfectly fresh fracture are seen. They are all well rounded and of all sizes up to a cubic NEPHELINE-ROCKS IN BRAZIL. 465 metre, mingled together in the greatest confusion, and loosely cemented by a paste of pebbles and minute rounded grains of the same nature as the boulders. With the exception of a few masses which are fragments of a preexisting and more firmly com- pacted conglomerate of the same aspect as that of which they now form a part, all the boulders and pebbles seen are of the same character and, to my eye at least, undistinguishable either macro- scopically or microscopically (except by a slight difference in colour, a light shade of red or a leaden colour being predominant) from the red rock of the adjacent cuttings. At one point a small mass of the red rock, decomposed, but evidently i situ, rests upon the con- glomerate, which is also cut by a small dyke which, in its decom- posed state, also resembles the red rock. A relation is thus estab- lished between this large and almost detached mass of conglomerate and the smaller patches, which are clearly included in the red rock, and the latter is thus seen to pass on the one hand into a fragmental rock, and on the other into a compact phonolite *. On the same spur, between the tunnel and Pinhalzinho, occurs the largest exposure yet known in the region of foyaite, which evidently forms a considerable portion of the mass of the spur, and appears in connexion with the red rock throughout a distance of about 2 kilometres. The rock is in general of rather coarse grain, but of even texture, and weathers into large rounded boulders, which, if the massive rock was not seen in the cuttings, might be taken for erratics. In one place, at the side of a small ravine, the texture is porphyritic, with large and small polygonal patches of coarse-grained whitish rock and large and perfect felspar-crystals seattered through a bluish finely granular ground-mass, in which, however, the granitic texture is still apparent. At the tunnel the relations of the foyaite to the red rock are very well exposed. High up on the side of the peak above the tunnel a considerable mass of foyaite is seen close alongside of a considerable exposure of the red rock. The tunnel is excavated in a large irregular dyke- like mass of foyaite that cuts the red rock, and is most probably continuous with that of the top of the peak some 500 metres above it. This mass of foyaite is separated by an intervening mass of red rock from another about 100 metres further up the ravine, in which a quarry hasbeen opened. The annexed sketches (fig. 4) of the two openings of the tunnel and of parts of its sides near the upper end show the relations of the two rocks. At the upper end, the lower _ part of the arch is of the red rock, rising highest on the left or upper hill-side; the upper part is of foyaite. A road cut on the right side, on a level with the floor of the tunnel, shows the foyaite entting out the small patch of red rock of the right-hand side of the mouth, but giving way to it again a little further round the hill. This appearance can only be explained by regarding the foyaite as an irregular dyke-like mass, some 10 metres or more thick, cutting _ * Judging from the reference in Rosenbusch’s ‘ Mikroskopische Physio- graphie,’ vol. il. p. 299, a comparison might be made between this rock and that from Teneriffe denominated eutaxite by Fritsch and Reiss. 466 MR. 0. A. DERBY ON the red rock at a low angle. The tunnel, which describes a strong curve, soon enters wholly into the foyaite, which appears in the floor, roof, and sides: but a few metres beyond, the red rock appears again irregularly, still msing highest on the left side when the exposure is continuous (3), while in front it is divided into three distinct masses, the foyaite sinking between to below the floor of the tunnel (4). The road-bed again rises above the level of the lower Fig. +.—WSections across and on the sides of the tunnel near Pinhalzinho. <2 xX =xpixx She ee FN ~ cal e ~ eee a. Foyaiie. 7 1. Upper mouth of tunnel. a 2. Lower mouth of tunnel. fas 3. Left side of tunnel near upper end. Tw 4. Right side of tunnel near upper end. w 4 contact oi the foyaite and the red rock, and contifues in the former ~ Bx to the lower opening, where the latter again appears im very small — ap patches on each side, which only rise very slightly above the floors. The foyaite forms quite a regular arch over the lower mouth of the tunnel (2); this comes out at the upper surface of the mass, which is covered completely by the red rock. The latter is here so broken into small iragments as to resemble an immense heap of chestnuts, and a land-slide of this incoherent material had, at the time of my visit, revealed a considerable surface of the foyaite on the slope over the mouth of the tunnel. This contact-surface was irregularly undu- lated, and inclined at an angle oi 15°—-20°. The rock-openings and — a part of the interior contacts have been concealed by masonry, but — a portion of the latter are still exposed. | - Both rocks near the contact are generally decomposed, and the red rock is everywhere too much so to reveal any modifications that it may have suffered. In places, however, the foyaite shows an in-— teresting contact-phenomenon. At about a metre away the rock becomes finer-grained, and passes rapidly into foyaite porphyry and finally into true phonolite, the phonolitic facies extending for 10-15 — "ed NEPHELINE-ROCKS IN BRAZIL. AGT centimetres from the immediate contact. Unfortunately I was unable to ascertain whether or not the same phenomenon is presented along the upper contact, as the places where it had been exposed were either decomposed or covered up by slides of the overlying red rock. Above the tunnel, for a distance of 5 or 6 kilometres, the cuttings (with the exception of those in the red rock and leucite-rock already mentioned, and situated close to the tunnel) are mainly in phonolite, generally much decomposed, and of no special interest. Im one a dyke of phonolite is seen, cutting a mass of decomposed foyaite, showing that if a part of the phonolite (as in the case of that enclosed i in the red rock and the conglomerate near the foot of the mountain) is older, or (as in the case of the peripheral portions of the mass at the tunnel, of the dyke in conglomerate above mentioned and of the rock described below) contemporaneous with the foyaite, a part also is newer. A cutting about 2 kilometres below the Cascata station shows inclusions of foyaite in bluish phonolite, some of which are of considerable size. These present sharply defined outlines, and are either circular or show a tendency to mimic poly- gonal crystalline forms. The next cutting above, which is through a broad low ridge of foyaite, exhibits exactly the reverse inclusions, that is to say, of phonolite in foyaite. This rock, which is apparently identical with that of two quarries off from the line of railway near the Cascata station, and almost in a straight line with the cutting, the furthest being at least a mile away, presents several inter esting characteristics. The rock in the main resembles quite closely that of the tunnel, but contains a glassy honey-yellow ingredient, which has not been noticed else Where. It is also marked by indistinct circular spots slightly darker in colour than the generality of the rock, as if drops of oil had been sprinkled over it. In places also the nepheline, which is generally bluish, takes on a rather brilliant red colour, and appears to present more distinctly marked crystallme forms. Small points -and thin irregular lines and, in one case, a pear-shaped inclusion two inches long, of an amethystine colour also appear. ‘The most interesting of its peculiarities, however, are the inclusions. Some \ of these are irregular masses more coarsely crystalline than the enclosing rock, which, owing to the predominance of large crystals of Ttelspar, have something of the aspect of pegmatite. Others are pebble_tike masses of fanecrned and darker foyaite, while others again, and these are the most common, are of phonolite. These are ~ of ali sizes up to that of a man’s head, with sharply defined and _ generally angular outlines, though without the mimicry of crystal- _ line form presented by the reverse inclusions of foyaite in phonolite. The smaller inclusions, often no larger than the end of the thumb, p are perfectly homogeneous in appearance; but in some of the larger ones there is a more or less distinct mixture of granitic and felsitic material. Two of the largest inclusions seen are here _ xepresented (figs. 5 and 6). 468 MR. 0. A. DERBY ON Fig. 5.—Phonolite-inclusion m Fig. 6.— Crystalline inclusion in Foyuite, one siath natural Foyaite, reduced about one Size. half. $y NA “ff fl Wale ae 7 aN | OTe i) f Gil 1 “ 7 mo LU ‘} v 7 iP Dig Once u T ff ff 7 ~My ‘ 4 i 2 LU Al, Hh rs Wisi, ZZ WN f Ai y W, lf UA HS Tt HN \ ie oN ey y T D A\\ ; f48 ily, The larger one (fig. 5), which is 9 inches long and 4 inches wide,. is a blue phonolite, with tolerably abundant crystalline inclusions in the left-hand portion, which become rarer towards the right. On the left side there is also a long, curved, ribbon-like inclusion of foyaite, which shades off at the lower end into the including rock through a group of scattered crystals, such as are common in phono- lite. The other one (fig. 6), which is about 4 inches long, is repre- sented above as it appears on an irregularly fractured surface. The dark-shaded portion is felsitic, and may, I think, be considered as phonolite, notwithstanding its abundant crystalline inclusions. It forms a distinct sheath, sharply defined against the enclosing foyaite, about the whole inclusion, and also about the three principal crystalline masses imbedded in it in the lower part of the mass. It appears, however, to shade into these, and into the smaller and less-defined inclusions of the upper part. These masses differ con- siderably in aspect from the enclosing foyaite, and are flecked with small dark patches apparently related to the felsitic mass. As the specimen has been placed in the hands of Prof. Rosenbusch, no further description of it will be attempted here, as, for my present purpose, it is sufficient to signalize the double nature of the inclusion, that is to say, of a rock of granitic texture in one of felsitic character, which is itself enclosed in a rock of granitictype. The appearance of this and other inclusions, coupled with the facts already stated, as to the occurrence of phonolite as a peripheral facies of foyaite, lead me to regard the inclusions, whether in the one or the other of the rocks, as parts of the same original magma. A petrographical exam- ination will doubtless determine whether this view is correct or not. From the cutting in foyaite, above mentioned, to the Cascata station the road winds for about a kilometre around a prominent spur, some 400 metres wide, of bluish-black and greenish tuff, which NEPHELINE-ROCKS IN BRAZIL. 469 in general appears quite homogeneous, but in many places shows layers and patches of pebbles up to the size of a hen’s egg. The pebbles could not be certainly recognized, but the most abundant appear to be similar to the diabase-like rock of the conglomerate at the foot of the mountain, only finer-grained and somewhat altered, so that only lath-shaped felspars could be made out with certainty. This tuff further resembles that associated with the conglomerate by the presence of rare and small flakes of brown mica. It is cut by small dykes of phonolite, and by dykes about 20 centimetres wide, too much decomposed for recognition, but which appear to be of a basic rock. One mass which I had noted in a field as a dyke, one metre wide, of a basic rock, proves on exami- nation to be composed mainly of granular quartz and magnetite, and is probably not a dyke, though it -certainly presents the appearance of one. The tuff is also traversed by horizontal vein-like masses, from one to two inches thick, of a highly felspathic rock of granitic or coarse porphyritic texture, and by vertical dykes, from 3 inches to 2 feet wide, of a rock that appears to be a more crystalline variety of that of the horizontal dykes or sheets. In the largest of these dykes, which is much decomposed, the felspar crystals attain the diameter of aninch. In aspect this rock resembles the felspathic veins of granite and gneiss much more than it does the foyaitic rocks of the region in which it occurs. Under the microscope it differs markedly from any rock known to me; but I suspect that it will prove to be an augite-syenite, or perhaps a liparite. Whatever it may be, it, with the phonolite dykes, serves to connect the tuff with the crystalline rocks of the region. Close by the Cascata station there is a small cutting in decomposed quartzite intercalated between two cuttings in tuif. The rock is so decomposed and broken by joints that its position could not be satis- factorily determined, but it appears to dip to the eastward at an angle of about 20°. It is cut by small dykes of phonolite and by very thin irregular veins of pegmatite, showing large quartz-grains and kaolin in the form of felspar, which I take to be ditterent from the felspathic dykes and layers in the adjacent mass of tuff. In appearance the rock is not very unlike the sandstone at the foot of the mountain ; but its occurrence at a much higher level, the presence of granitic masses apparently distinct from the eruptive group that characterizes the region, and, above all, the occurrence in similar conditions at another point, to be described below, of undoubted itacolumite, lead me to refer this exposure to a series much older than that represented at the foot of the mountain. At Cascata the road leaves the wooded slope of the valley of the Quartel and enters the Campo region of the mountainous plateau of Caldas. This plateau extends northwards some 15 or 20 miles to the Rio Pardo, which, where I crossed it, flows at an elevation of 875 metres. The mean elevation of the plateau is about 1200 metres, the undulating surface presenting differences of level of from 100 to 200 metres. It is bounded on the west and north by an approxi- mately semicircular arc of ridges rising abruptly from 200 to 400 A70 MR. 0. A. DERBY ON metres above the general level. Similar but shorter detached ridges (the Serra do Caracol and Serra de Caldas) to the southward and eastward appear to complete an approximately circular or elliptical enclosure (fig. 7). This circular arrangement of the higher ndges is peculiar, and, taken in connexion with the character of the pre- dominant rocks of the plateau and of the bounding ridges, as far as examined, is probably not without significance. Fig. 7.—Sketch Map of the Caldas region. x“ yy, y, Ue ZB B Wy, Wi \WLonnel (1051 m.) Ne Vamee — is “, SS \*3] si SS R Re Se S <— = My | if i} Z YG Se, ij oe RN wll Si allt rani /7s anita NN \NS TT RW) =\\int suai Sane ROS AAR WAS itRSS Serra de Caracol In the 18 kilometres of railway from Cascata to the village of Pocos the cuttings are mainly in decomposed rock, which is, however, sufficiently preserved in patches to show its original character, either in loose masses or in the traces of structure still visible in the clay resulting from decomposition. The predominant rock is phonolite. Foyaite appears rarely in a few cuttings, always totally decomposed. No evidence of the existence of other rocks was met with, and the absence of dykes is noticeable. About 4 kilometres from Pocos two cuttings in decomposed phonolite show an abundance of decomposed analcime, some of the crystals measuring 3 inches in diameter. Near Cascata two quarries, already referred to, have been opened to the right of the road in hills of foyaite with abundant inclu- sions. Close to one of these there is a hill of coarsely porphyritic phonolite unlike any variety seen on the railway. The crystalline inclusions are of all sizes up to an inch in diameter, with ill-defined limits and generally stained red, the red colour extending at times to the ground-mass, which is normally bluish, the inclusions being white. This reddening of the rock without visible signs of decay has extended to nearly the whole quarry, so that masses free from NEPHELINE-ROCKS IN BRAZIL. ATL it are somewhat difficult to find. It is seen, however, to be most pronounced near the surface and in the neighbourhood of fissures, and is undoubtedly due to weathering or to infiltrating waters. This phonolite differs further from all other varieties seen in the region, except that of the Prata bridge, in being fit for a building- stone on account of its freedom from the fine joints and splintery fractures that generally characterize the Caldas phonolites. About the village of Pocos the phonolite is generally distinctly granular, and might perhaps be regarded as a fine-grained foyaite. The hot sulphur springs (temp. 45° C.) that give name and importance to the place issue from the midst of the phonolite. The hill close to the village (1600 metres high, the highest of the semicircular ridge) was examined for a distance of over a mile, and found to con- sist exclusively of phonolite. This rock also characterizes the road from Pocos to the Rio-Pardo margin of the plateau, occurring also with foyaite along the descent, but, apparently, not extending beyond the river. The Rio das Antas, the principal stream of the plateau, just before it breaks through the ridge to descend to the Rio Pardo, traverses for several hundred metres a considerable patch of quartzite. In places this shows the flaggy structure and other cha- racteristics that identify it with the itacolumites so abundant in the province of Minas. The geological age of the series to which it belongs has not been determined for Brazil, but it is certainly very old. Rocks similar to it and to its associates are called Huronian by many North-American geologists. The strike is N. 20° W. *; dip 20° $.W. C>B; while in common epidote it may be expressed in the following scheme*,C>B>A. Therefore the clinopinacoidal sections of this mineral show the most intense colours, while those parallel to the ortho-axis display a lighter tint. When a slide is prepared in the direction of the planes of schistosity in the rock, we usually see sections approximately parallel to the b-axis; but we also perceive a marked difference in the colours of various sections suggestive of entirely different minerals; the one is a deep violet, the other a brownish yellow. As there are great differences in the axial colours already stated, it may be naturally expected that a section parallel to the basal pinacoid M is of a brownish yellow ; for we see the combination of the axial colours of C and B; that which is taken nearly parallel to the orthopinacoid T is of a deep violet (a combination of A and B). The clinopina- coidal section shows the deepest shade of colour, the face-colour being a combination of C and A. * Rosenbusch, ‘Mikroskopische Physiographie,’ i. p. 497, 2te Auflage. den PIEDMONTITE-SCHIST IN JAPAN, 47% The extinction-direction is, of course, parallel and at right angles +o the longer sides of sections in the zone of M and T, and the in- tensity of the colours also depends upon the section in this zone. The polarization-colours are magnificent, ranging from an intense violet to an indigo-blue tinge, and this becomes more pronounced if we insert a quartz-plate in the tube of the microscope. The piedmontite is generally pure; neither liquid-enclosures, gas-enclosures, nor microlithic interpositions being found in large quantities. Minute crystals represent the ideal purity of the mineral. This mineral has been isolated from other constituents of the schist from Otakisan, Awa province, by means of Thoulet’s solution. The result of the chemical analysis, kindly undertaken by Mr. J. ‘Takayama, of the Geological Survey of Japan, is as follows :— OL) Bec mates SIM Set omega 36°16 Al,0, SP Sea Citeeete tM hp > 22°52 ION a ake tat as Sel ae 9°33 ae Se Aeon Saha ee ¥ ae 5 Orne hansen 22° EM, 52 nl sgBtiy seater ate tes, «5 0-40 RO) ais Cem res te» trace ITN Oey 6 seek see eehc Weems be 0-44 1BL QMS pstnteip le See tr eg aae 3°20 100°53 ele Cail, = 2:2 Cas Re er eae 92 (b) Comparison with other Occurrences.—On comparing the result stated above with analyses of Swedish and Alpine epidotes * our mineral shows in some particulars a marked difference in the per- eentage-composition from both of them; there is nevertheless a general resemblance in all, and the Japanese epidote supplies a hitherto missing link between that of Jacobsberg, in Sweden, and that of St. Marcel, in Piedmont. Mr. Takayama states that he is as yet unable to decide whether the manganese in the Japanese epidote exists as sesquioxide or as monoxide, or as both. Igelstrom suggests that the Swedish mineral contains manganese as the monoxide, while others are of opinion that in the Alpine epidote the manganese exists only in the condition of sesquioxide. Some mineralogists therefore hesitate whether they should be regarded as the same mineral varietyy. The writer before expressing himself decisively on this point awaits the results of a more complete examination. Being of a very beautiful rose-red colour, highly pleochroic and acicular in habit, piedmontite is frequently confounded with tour- maline, and as such it was at first regarded by us. Dr. KE. Naumannt * Rammelsberg, ‘ Mineralchemie,’ 2te Auflage, p. 595. » + Naumann; Zirkel, ‘Hlemente der Mineralogie,’ 12te Auflage, p. 577. t ‘Ueber den Bau und die Entstehung der japanischen Inseln,’ Berlin 1885, p. 10. Q.J.G.8. No. 171. 2k A78 PROF. B. KOTO ON OCCURRENCES OF notes that there are two interesting rocks in the erystalline-schist system of Japan, one of which is “ ein echter durch charakteristische rothe Farbung kenntlicher Turmalinschiefer, der unter dem Mikro- skop schongefairbte starke dichroitische langgestreckte Krystalle zeigt.” The original specimens from which E. Naumann penned the above-quoted statement were kindly placed at my disposal by the Geological Survey of Japan. On examining the various slides the writer was firmly convinced that here we have to do with true pzed- montite, and not a tourmaline; and the analysis given above confirms the writer’s view. (c) Geographical Distribution of Piedmontite——The mineral pied- montite is not of common occurrence. In treatises on mineralogy we find only two typical localities up to the present: the one is St. Marcel, near Aosta, in Piedmont, Italy, where it occurs, as a rare mineral, together with other manganese ores ; the other is Jacobs- berg, in Wermland, Sweden, where it is found localized within a limestone. In both cases, as it seems to me, piedmontite occurs as a rare mineral, and it is by no means abundant enough to form an independent rock. Its extensive occurrence in Japan is somewhat remarkable, and is probably unequalled in other parts of the world ; the manganepidote and quartz constitute the piedmontite-schists, and it is also an acces- sory component in glaucophane-schist *. Geologically speaking, its occurrence is confined to the same horizon as the glaucophane, ?. e. the lower part of the chlorite-schist series of the Archzean complex. This unique piedmontite-bearing rock is of unexpectedly wide dis- tribution, and constitutes, indeed, an essential member inthe Archean system of Japan. The subjoined are some out of many of the typical Japanese localities of manganepidote :— Sikoku Island. 1. Otakisan, near the city of Tokusima, Awa province. 2. Bessi Copper-mine, in Uma Gori, Sanuki province. 3. Chihara Copper-mine in Sitfu district, Kitanada in Kami- Ukima district, Uchinoko and Kaya in Kita district, Lyo province. Main Island. 4, Minano, Simo-Tano and Yori, Chichibu district; Ogawa, in Hiki district, Musasi province. 5. Umenokidaira and Sambagawa, Kanra district, Kozuke pro- vince. 6. Misaka, in Iwamae district, Iwaki province, &e. (d) A peculiar Hpidote—There is still another variety which may be conveniently described on the present occasion. In speaking of the glauecophane-schist in his other paper‘, the writer has already given a brief notice of the presence of a remarkable piedmontite. * Journal of Science College, Imperial University, Toky6, vol. i. part 1. B. Kot6, ‘A Note on Glaucophane,’ pp. 85 é7¢ seq. t Loc. cit. p. 85. PIEDMONTITE-SCHIST IN JAPAN. A479 In this schist we find a peculiar epidote in the form of long irregular plates (}+1 centim.), having a slight yellowish-green colour, and being irregularly traversed by transverse cracks and longitudinal strie. The morphological habitus differs from that of an ordinary epidote in its more flattened tabular condition. It possesses sometimes a faint rosy tint, its pleochroism is weak, but distinct, being more in- tense when the short diagonal of the lower nicol is at right angles to the longer sides of the epidote. In other instances the red pig- ment is localized in the centre (fig. 4), so as to form a distinct zone ; but the reversed case, ¢. e.a red margin with the yellow centre, has, within the writer’s knowledge, never yet been observed. The rosy pigment which characterizes this epidote is certainly due to the presence of a manganese oxide, and the mineral forms an intermediate link between common epidote and piedmontite. One point in connexion with this epidote should not pass unnoticed, namely the abundant enclosures of aggregates of opaque iron-glance, and blood-red hexagonal scales of the same mineral, since the typical piedmontite is entirely free from enclosures of such a kind. This indicates the fact that the latter (piedmontite) has crystallized out before the yellowish-green epidote. (e) Garnet.—In the glaucophane-schist from Otakisan, in the Island of Sikoku, we find a large number of rhombic dodecahedra (size of a pea) of a greenish-yellow garnet. A slide cut from one of these garnets shows, under the microscope, that it is made up of different minerals as indicated in figure 5. This crystal is, indeed, a small mineral cabinet of all the constituents of the rock in which it occurs, except glaucophane. The violet piedmontite needles, clumps of dark iron-glance, hexagonal scales of iron-glance, the knee-shaped twins of rutile-needles which contain in their substance also a large number of already twinned crystals upon Po, and, lastly, highly 2K 2 480 ON OCCURRENCES OF PIEDMONTITE-SCHIST IN JAPAN. vitreous grains of quartz, are all thrown together within the garnet crystal, these enclosures assuming a more or less curved course. The colour of the garnet itself is deep yellow, and the crystals show anomalous optical: properties, being anisotropic. This is Fig. 5. caused probably by the strain from the interposition of other minerals contained in it. Prof. Bonney* has also found garnet in cer- tain glaucophane-bearing rocks near Berrioz, Val d’Aoste, in the Alps. Here the garnet sometimes contains glaucophane and dark dust (?), which he suggests may be possibly due in certain cases to subsequent infiltrations. The garnet here described is entirely free from enclosures of glaucophane, although the rock itself is a glauco- phane-schist; and the above-mentioned interpositions, 2. ¢. pied- montite, &c., seem to have been developed prior to, or contem- poraneously with, the formation of the garnet. Discussion. The Prestpent remarked that, in the slides, where the glauco- phane was best developed, there the piedmontite was most rare, and that where the piedmontite was abundant but little glaucophane was to be seen. He alluded to the striking pleochroism of the piedmontite, end to the interesting fact of its having been now recognized for the first time as a rock-constituent. Mr. Miers, whilst claiming but lttle special knowledge of the minerals described, expressed his satisfaction with the paper. Mr. Huptzston said that the President’s remark precisely con- firmed Mr. Koto’s statement to the effect that the piedmontite exists only as an accessory mineral in the glaucophane-rock, whilst it is one of the principal constituents in the piedmontite-schist, which contains hardly any glaucophane. * «On a Glaucophane-eclogite from the Val d’Aoste,” Min. Mag. vol. vii. no. 32, p. 2 (1886). ON THE ROCKS OF THE MALVERN HILLS. 481 30. On the Rocxs of the Matvern Hitis. By Franx Rovrrey, Ksq., F.G.S., Lecturer on Mineralogy in the Royal School of Mines. (Read December 1, 1886, and April 6, 1887.) [Prates XITX.-XXT_] Part I. Tue rocks of the Malvern Hills have already been the subject of much discussion, and some of our most eminent geologists have devoted a large amount of time and trouble to the unravelling of their history. One of the most important papers, however, upon this subject was written by Dr. Harvey B. Holl *, over twenty years ago; and with this paper and a few maps I have spent several weeks in examining the range. The general result of this examination may be of interest, inas- much as it enables me to confirm to a great extent the statements made by Dr. Holl, whose careful observations and sound inferences cannot fail to impress those who endeavour to follow up his work. One of the main points which Dr. Holl wished to demonstrate was, “that the rocks which had hitherto been treated of as syenite, and supposed to form the axis of the hills, were in reality of meta- morphic origin, and belonged to the Pre-Cambrian, Azoic, or Lau- rentian Age.” I think that, at the present day, many geologists will be found who are ready to accept this conclusion, in spite of the protest of the late Sir Roderick Murchison 7. Dr. Holl, in his paper, discusses first the structure and origin of the crystalline rocks of the Malvern Hills, he next treats of the adjacent Paleeozoic strata, and finally endeavours to show the chrono- logical relationship of the several events in their geological history. Without attempting to follow out such an extensive programme, I have restricted my work to the old ridge of gneissic syenite, granite, &c. which constitutes the central or axial, and, indeed, the main portion of the range; and although I have failed to see many things, I have nevertheless verified much that Dr. Holl, the late Professor Phillips f, the Rev. W. 8. Symonds §, and other observers have recorded. At the outset, Dr. Holl describes the small hill known as Keys End or Chase End as consisting, at its southern extremity, of thinly bedded gneissic rocks dipping east, the gneiss being some- times micaceous, at others hornblendic. This hill is the extreme * “On the Geological Structure of the Malvern Hills and Adjacent Districts,” Quart. Journ. Geol. Soc, vol. xxi. pp. 72-102. T ‘Siluria,’ 4th edition, 1867, p. 14. t ‘ Memoirs of the Geological Survey,’ vol. ii. part 1. _ § ‘Old Stones, a series of Geological Notes on the Rocks in the Neighbour- hood of Malvern,’ new edition, 1884. 482 MR. F. RUTLEY ON THE ROCKS southern member of the Malvern range, and after a more detailed description of it Dr. Holl carries the reader gradually northward. Without following his description further at present, L will at once venture to expound the view to which my own examination of the range, coupled with a careful perusal of Dr. Holl’s paper, has led me—a view which begins at the other end of the chain, and which, if true, may result in a better understanding of its structure. In the first place, the beds of crystalline rocks, mostly of a gneissic character, which form the axis of the Malvern range have, I believe, been disposed in a synclinal flexure, which stretched from the north of the range as far as the middle of the ridge which forms Swin- yard’s Hill, where there is, I think, evidence to show that they experience a sharp anticlinal flexure and are then faulted down- wards, to reappear no more in this country. The synclinal fold just mentioned, which is over five miles and a half in length, is probably more or less irregular through subordinate crumpling of the beds, and, in common with the rest of the range, is traversed obliquely by a number of approximately N.W. and 8.H. or N.E. and 8.W. faults, as already indicated by Dr. Holl. Inferences regarding the upthrow or downthrow of the masses lying between these faults may, perhaps, be most safely arrived at from the corresponding displacements of the Silurian strata which occur on the western flank of the range, and although from a little north of Malvern Wells to the extreme north of the chain there appear to be successive downthrows to the north, yet south of Malvern Wells the throws vary. From lithological evidence generally, it seems that the rocks forming the northern portion of Swinyard’s Hill are a repetition of those which constitute the Worcestershire Beacon, and the assumed relationship of the beds is indicated in the diagrammatic section appended to this paper (facing p. 488) *. We may infer that probably, but not necessarily, the oldest and once most deeply-seated beds of gneiss would be those which would have undergone the greatest alteration, that traces of bedding in them would be rare or very obscure and irregular, and that in crystalline structure they would approximate more closely to plutonic rocks than the higher beds of the series. In other words, we should expect to find the older beds occurring in the condition of coarsely erystalline gneiss, or even of crystalline rocks devoid of foliation, and the younger of finer texture and approximating to schists. In the Malvern range we find the most coarsely crystalline rocks in the northern, and the fine-grained rocks and schists mostly in the southern hills. Hence it may, I think, be inferred that the rocks * On referring to Phillips’s Memoir, the following statement concerning what he termed “mottled syenite ” will be found :—‘“‘ As already observed, it is in the northern parts of the Malvern range, and especially north of the Worcestershire Beacon, that this beautiful rock appears most abundantly. It is, however, not entirely absent from any of the hills, at least in small masses. On the crest of Swinyard’s Hill it may be found amidst the great variety of compounds which that narrow and interesting ridge presents.” (Mem. Geol. Surv. vol. ii. pt. L, p. 41.) . OF THE MALYERN HILLS. 483 constituting the northern parts of the chain are older than those which occur in the southern end. The rocks of the North Hill and the Worcestershire Beacon are, as a rule, coarsely crystalline, and, I believe, older than those of the Raggedstone and its vicinity, which are for the most part of a schistose character. Owing to frequent faulting and subsequent denudation, the regular chrono- logical sequence along the range is more or less disturbed, and in this manner we meet with very coarsely crystalline rocks in the northern part of Swinyard’s Hill, only two or three miles from the southern extremity of the chain, which appear closely to resemble some of the very old rocks in the northern parts of the range. The flanking beds of Paleozoic strata, which abut against the western side of the chsin throughout its entire length, occur only on the eastern sides of the southern hills; and it does not seem un- reasonable to suppose that their partial preservation on this side is due to the downthrow towards the south of the southern portions of the old ridge, although it must be admitted that there are some objections to this view. _ Most of the faults which cross the axis, generally in N.W. and S.E., and N.E. and S.W. directions, have been indicated by Dr. Holl, who has traced them by means of breccias, or inferred their ex- istence from marked discrepancies in the strike of the beds. An examination of the ground shows how carefully he has done this; but I have ventured here and there to extend some of these lines of fault from the Silurian area across the gneissic rocks, on the strength of somewhat meagre evidence not recorded in his paper. As already mentioned, one of the most striking lithological features of this range consists in the generally coarsely crystalline character of the rocks forming the North Hill, the Sugarloaf, the Worcestershire Beacon, the Herefordshire Beacon, and the northern part of Swinyard’s Hill. These constitute two well-marked masses when regarded lithologically—the first extending from the northern end of the chain to the Wych, while the second reaches from the northern foot of the Herefordshire Beacon to the fault which crosses Swinyard’s Hill. These two masses consist, for the most part, of coarsely crystal- line gneissic rocks, sometimes hornblendic, at others micaceous ; while non-foliated rocks of similar mineral constitution also occur, which may be regarded as syenite and granite. Beds of much finer texture are also met with within these areas, but the general character of the two masses is a coarsely crystalline one. The contrast between these rocks and those which constitute the other portions of the range, which consist mostly of schists and thinly bedded gneissic rocks of finer texture, has been specially noticed both by the late Professor John Phillips * and by Dr. Holl. * Schistose rocks more or less approaching the character of gneiss are more abundant in the Malvern Hills than might be expected. They occur prin- cipally in the West Raggedstone Hill, about its summit; in the northern parts of the Midsummer Hill, and in the hills south of the Wych; but there are various other more limited exhibitions of such compounds.” (Mem. Geol. Surv. woOl. i. pt. 1, p. 43.) A84. MR. F. RUTLEY ON THE ROCKS The first, or northern, coarsely crystalline mass is cut off on the south by a fault near the Wych Pass; while the other coarsely crystalline mass is bounded by a fault on the north of the Here- fordshire Beacon, and by another which cuts across Swinyard’s Hill, near the highest part of the ridge. It is to these three faults that I would specially direct attention, as they appear, from adjacent lithological evidence, to be the principal dislocations of the chain. We will deal first with the northern mass. Dr. Holl states * that there is, nearly opposite the ravine (the Dingle) which separates the Worcestershire Beacon from Summer Hill, a fault which ‘‘ has carried the Woolhcpe Limestone, on its southern side,. 30 yards further to the west.” Meeting with breccia on the eastern slope of the range in the vicinity of St. Ann’s Well, it occurred to me that it might indicate a fault and that the line of fault just alluded to, and which is Shown on the map accompanying Dr. Holl’s paper, would, if produced, touch the spot at which this breccia occurs. Drawing such a line across the Ordnance six-inch scale map, I endeavoured to trace the breccia, and found a small exposure of it just where the line crossed the ridge of the hill, above and a little to the south of the head of the Dingle.. Several hours of search for further evidence resulted in the discovery of breccia at various points, near the line, but sufficiently far from it to show that, if the breccia indicated a fault, it was either very sinuous or, more probably, was itself faulted by transverse disloca- tions. JI think, however, it may be assumed that a fault does actually cross the range at this point; for, apart from the occurrence of breccia, the strike of the rocks composing the Worcestershire Beacon does not agree with the general strike of those on the other side of a line drawn along the Dingle and over the ridge to St. Ann’s Well, Roughly classifying the chief rocks of the Malvern axis, we may separate them into three groups, viz. :— Upper group =Schists and fine-grained gneiss. Middle group = Fine- and medium-grained gneiss. Lower group = Medium- and coarse-grained gneiss, with diorite and granite. Between these groups there exist no definite lines of demarca- tion, all three groups being composed of alternating beds of variable texture. The Upper group ‘is, however, specially characterized by the prevalence of schists, while the Lower group consists mainly of beds of very coarsely crystalline gneiss alternating with granite, syenite,. and diorite. The range from the extreme north to the Wych consists mainly of the Lower, with perhaps the base of the Middle group. From the Wych to the Herefordshire Beacon the rocks belong chiefly to the Middle group. But it seems probable that some of. * Op. cit. p. 95s OF THE MALVERN HILLS. 485 the highest beds a little south of Malvern Wells should be referred to the base of the Upper group. The Herefordshire Beacon is probably composed chiefly of the top of the Lower and bottom of the Middle groups, but exposures of rock are not very numerous; while the northern part of Swinyard’s Hill belongs, I believe, to the Lower group. South of the fault which crosses Swinyard’s Hill down to the south end of the range the rocks belong to the Upper group, except perhaps the southern portion of Midsummer Hill, which may represent the top of the Middle Group. In support of such evidence as appears to me to denote repetition of the gneissic beds, I cannot do too than quote the sequence of rocks recorded by Dr. Holl.in various parts of his paper, since, although he disclaims any belief in the repetition of these beds, his observations are in most instances of a much more detailed character than my own. Thus on pp. 76 and 77 of his paper he gives a list of the beds traversed in passing from the southern to the northern end of Swinyard’s Hill, stating the approximate thicknesses as: shown along the crest of the hill. Beginning at the south end he records :— tte Micaceous schist and fine-grained gneissic rocks, with a few subordinate bands of horn- IS MiG SONS Gey: aGaiwanckt 15 { 680 MUS cern Net tc Rac A cadeccelulsisticiuaese tenes 85 Here we have, assuming his granulite to form the axis of a fold, 665 feet of rock on one side, corresponding more or less precisely in lithological characters with 595 feet of rock on the other side, es a margin of 85 feet of unseen rock to supply a deficiency of O feet. These beds belong to what I have here termed the Upper Group. They are succeeded on the north, according to Dr. Holl, by trap- rock, micaceous and hornblendic schists, and fine-grained gneissic rocks with subordinate bands of hornblende-schist. Then follows what I conceive to be another, but a minor, fold, viz. :— ft. Diorite, rich in hornblende, with small quartzo- HE US FEN MICE MCI ote and accel aic oa aisle Gwen siemeaises sede snes ISICINISIE igh Nba RMR BEI eS bocicccG/ RGEC AS Sele ena EPPA nar 3 Diorite, rich in hornblende, with many quartzo- RCSL MLC VEL yc eecye Ee Merne cctint ete sai nccdcuneveessuesteanwese Here, then, judging by the approximate thicknesses, we have in all probability a repetition by flexure. If the coarsely crystalline rocks forming the northern part of 486 MR. F. RUTLEY ON THE ROCKS Swinyard’s Hill be a re-emergence of the beds forming the Wor- cestershire Beacon, it then becomes. interesting to compare the immediately superincumbent rocks in the Herefordshire Beacon and those in the tract lying between the Wych and the Worcestershire Beacon; and we may, for this purpose take Dr. Holl’s statements as a close approximation to the truth. In the Herefordshire Beacon he records the presence of gneissic rocks, both hornblendic and micaceous, mica-schists, hornblendic rock, and large granite veins. From the Wych to halfway up the southern slope of the Worcestershire Beacon he also notes the occurrence of mica-schists, hornblende-schists, gneissic rocks, diorites, granitoid rocks, and granite veins. In this series, out of a roughly paced distance of 677 yards, about 400 yards consists of rocks described as schistose and gneissic, and it therefore seems quite possible that they are the northern representatives of the rocks forming the Herefordshire Beacon, which, as already mentioned, may probably be referred to the upper part of the Lower and the lower portion of the Middle groups. In these questions of correlation I speak with great diffi- dence and must disclaim any wish to dogmatize. I would rather suggest, leaving future observers to draw their own conclusions. The probability of the repetition of beds here indicated has gradually forced itself upon me, both from field-work and in the endeavour to construct an intelligible section* through the range; and, on reference to the latter, it will be seen that the elevations and sub- sidences of the larger rock-masses have, I think, often occurred somewhat unevenly, while, in addition to this, I believe that some of them have sunk more or less to the east or west during the movements which have shattered and faulted the ancient ridge. Throughout this paper I have spoken of the bands of gneiss, schist, and other rocks which constitute the chief mass of the Malvern Hills, as beds. This has been done partly for the sake of convenience and partly because the foliation of these rocks seems, as a rule, to be parallel to the divisional planes which appear, on the sround, to represent stratification. Aware of the difficulties which environ questions connected with foliation, I would, indeed, prefer to employ the expression divisional planes in heu of stratification, bedding, or any more precise term. Darwin, whose observations on this subject are, in the main, opposed to the assumption that direc- tions of oven agree with Piers of bedding, has remarked that the strike o the foliation in most countries lies parallel to axes of elevation +; but if the ridge of the Malvern hills be an axis of elevation, the general law which he here enunciates is apparently violated throughout a considerable part of the range. That such repeated change in the strike of the divisional planes * The views of the late Professor Phillips, although given in considerable detail in the Memoirs of the Geological Survey, are simply expressed on the published sections by a wash of vermilion. + ‘Geological Observations on South America, 1846, p. 166. See also Scrope’s ‘ Volcanos,’ 2nd ed. 1862, p. 299. OF THE MALVERN HILLS. 487 may have been brought about by the faulting of rocks in which there may have been once a persistently uniform strike, is, however, a possibility not unworthy of consideration*. On the other hand, the arguments in favour of the divisional planes being old planes of bedding appear to rest on the parallelism of the foliation to the divisional planes, on the seeming interstratification of rocks which exhibit no foliation, on the marked diiterences in texture shown by adjacent bands or beds, and also on the differences which occur in their respective mineral constitution. If we assume these rocks to be metamorphosed sediments, it follows that they were originally bedded, but it does not necessarily follow that they were all sub- sequently affected by cleavage; and we do not therefore seem justified in the inference that the foliation in this case is parallel to structural planes which may have existed, to the exclusion of the possibility that it may be parallel to others which, if the rocks be metamorphosed sediments, we feel assured did exist f. The reference of cases of more or less advanced metamorphism, and the accompanying phenomenon of foliation, to the shearing or creeping movement of one rock-mass over another, may induce many to search in the Malvern range for evidences of disturbance other than those already mapped as faults. Pending the result of such inquiries, it seems better to leave one’s mind in a receptive state than to crowd it with opinions of questionable value. In the meanwhile strikes and dips indicate the directions and inclinations of structural planes ; but whether those planes denote an original stratification is an open question and one upon which it seems unsafe to express any decided opinion. The upheavals and plications which the older rocks have undergone render it more than likely that in many mstances the steeply inclined planes of foliation do actually agree with steeply and similarly inclined planes of original stratification in rocks in which cleavage has not been induced, at least to some extent and along parallel portions of folds. On the other hand, the facts recorded by good and competent observers show that in a great number of cases unanswerable proof exists that often, over wide areas, the planes of foliation agree with planes of cleavage, and do not in any way correspond with planes of original stratification. Interbedded lavas and other eruptive rocks are also frequently present in most of the older formations, and it is therefore needful to remember this in accounting for some of the more strongly marked lithological differences in contiguous bands. * The foliation was developed in the range before the faults were formed, since the faults cause marked changes in the direction of foliation. In de- scribing the old ridge of the Malvern Hills as an axis of elevation, we are probably expressing merely a partial truth, since the ridge is, most likely, only an upeast portion of an axis of elevation, disrupted by north and south fissures. + The late David Forbes considered that the direction of foliation agreed in all cases with the planes of least resistance, whether planes of stratification or cleavage, or, in eruptive rocks, with “ striz of fusion.” (‘The Structure of Rock Masses,” Popular Science Review, vol. x. p. 236.) 488 MR. F. RUTLEY ON THE ROCKS Again, we must remember that cleavage- and other superinduced structural planes do not bound any marked differences in texture or, more especially, in mineral constitution, unless they agree with planes of stratification ; and this appears to be a matter worth some consideration, for, if foliation invariably agree with planes which are not planes of stratification or lamination, we have to account for the very marked differences in texture and often in mineral constitution which are frequently met with in metamorphic rocks, and which certainly simulate, even if they do not actually represent, bedding. In a district such as the Malverns it is most easy to be led astray by appearances, and amid the many tempting possibilities which present themselves a wrong one may be chosen. It may be that I have done so in treating these gneissic and schistose bands as stratified beds of rock; but, if so, the error begins and ends with the treatment; for although I am inclined to believe that the divisional planes, with which the foliation appears to be parallel, may be planes of original stratification, and, although I have based the accompanying section upon such a possibility, I regard these planes for the present merely as structural planes of some sort, between which the rocks exhibit divers lithological characters *. Note to accompany the Plans and Section. For the sake of clearness two plans are given in juxtaposition, on one of which, fig. 2, only the faults are shown. Those given on Dr. Holl’s map are represented by continuous thick lines, while my own extensions of them are indicated by dotted lines. The outcrops of the Upper Llandovery beds and the Woolhope limestone on the western flank of the range serve to show the direction of the dis- placements produced by some of these faults. On the other plan, fig. 1, strikes and dips as well as faults are represented, those strikes recorded by Dr. Holl being shown by continuous strokes, while those which I have added from observa- tions made on the ground are denoted by dotted lines. The accompanying section (fig. 3) must be regarded as more or less dia- grammatic, its purpose being to illustrate the views put forward in this paper concerning the general structure of the range. To render the section less confused, the trap-dykes and the numerous granite or pegmatite veins which have been described are omitted, since although there is abundant evidence that some of them are intrusive, it seems by no means certain that many of those which follow the general strike of the beds do not actually belong to the gneissic series in which they occur. * During the completion of the first part of this paper, in which the work of Dr. Harvey B. Holl is so frequently cited, came the sad intelligence that that skilled geologist had been taken from our ranks. He leaves to us in his writings a lasting memorial of conscientious research. Q. J. G.S. vol. xliti.} k [To face p. 488. Fig. 1.—General Plan, showing Dips, Strikes, and Faults. HEREFORD BEACON MIDSUMMER HILL ee Limestone | Dlandove”'y tHe wonsESTER «> NORTH 7 WYCH EACONGETAY| HILL \\winos i POINT // | iz, oH \ \ Fig. 2.—General Plan of the Malvern Range, indicating Localities and Faults. (Seale 1 inch to a mile.) Fig. 3.—Diagrammatic Section from South to North, through the Malvern Hills. Ss. = % N. | 5 F £ z 5 E = z Pe Fs a 8 Z = a2 & 5 =e Ee =H = ER Fal SI ee) 5 z 2 é E 2 a F 4 i , i \ i i t ! | Lh la : i i 1 7 H Hs ge i a : ” H m7 Ge | eS i a LP ndage b H — y © we ETS é SS f Shas \\\ eae - —S IWS Sy BSS SSS F Fad F gr =Upper Gneissic Series, including mica-schisis, quartzites, and fine-grained gneiss. db=Diabase, BSSAS tg=Wornblende Gabbro. gn’ =Middle Gneissic Series. Foliated rocks of medium and fine texture. d=Niorite. ieee gn =Lower Gneissic Series, Yoliated rocks, mostly of coarse texture. md=Mica-diorite, |*#t#+34/G Granite, including Hornblendic Granite and : 2 =Miea- ec. eat es 8 tees ACT $ eee 7 — Granulite. [Quartz-syenite. “F P=Faults, > Neath ae aS pe ey eR aim PE ‘ ie OF THE MALVERN HILLS. A89 The greatest vertical displacement indicated in the section is connected with the fault which crosses Swinyard’s Hill, and, as drawn, it would appear to be about 3000 feet; but it is very probable that this amount of throw may be divided between this and two other possible faults, one of which may occur in Phillips’s “ Silurian pass” on the north of Swinyard’s Hill, while the other may be situated in “The Gullet” between Swinyard’s Hill and Midsummer Hill. This view derives some support from a statement made by Dr. Holl to the effect that “the several passes which divide the chain of the hills at intervals are probably, some of them at least, determined by lines of fault, as the direction of the strike of the rocks on opposite sides of these passes is, In some cases, abruptly altered ” *. No sharp demarcations occur between the Upper, Middle, and Lower Archean groups which I have here ventured=to propose. The very existence of any one of these groups depends upon the predominance or paucity of schistose beds, upon characters dependent upon coarseness of crystalline structure, thickness of bedding, and, in fact, upon the general nature of the rocks which constitute each group. Parr II. On the Rocks of the Malvern Hills. In the first part of this paper the general structure of the Malvern Range was considered; but, at the time it was written, I had not microscopically examined the recks which were collected during my stay in that district. - The details of this microscopic examination mainly constitute the second part of this paper; and I may here state that the micro- scopic evidence does not appear to me to disagree in any important respect with the views advanced in the earlier communication, except that truly eruptive rocks are more plentiful in the range than I had at first imagined. The following details relate to specimens which were selected as typical :— No.1. North Mill. Largest quarry on North face of hill.—Coarsely erystalline rock, consisting of pinkish-brown or flesh-coloured felspar, black hornblende, small scales of dark mica, and some quartz. This rock shows very coarse and strongly marked folia- tion, the hornblende and mica forming irregular and somewhat lenticular streaks, which are often an inch or more in breadth and are rudely parallel; but the bands do not appear to be con- tinuous, as a rule, for any great distance, and a band frequently thins out altogether. his is the coarsest example of foliation I have met with in the Malvern range. Under the microscope some of the larger felspar-crystals are seen to be microcline, the twin- lamellae crossing approximately at right angles and undergoing maximum extinction when rotated 15°. Orthoclase twinned on the * Op. cit. p. 95. 490 MR. F. RUTLEY ON THE ROCKS Carlsbad type is also present, and, judging from the angles of extinction, there is more or less andesine. Apatite crystals are numerous, and magnetite is also plentiful, occasionally in octahedra, but mostly in irregularly shaped patches. Quartz is plentiful, and it contains great numbers of fluid lacune which frequently lie in more or less well-defined bands, an arrangement which is probably due to pressure, aS pointed out by Prof. Judd in the quartz-grains of certain crushed quartzite-pebbles; but in this rock the stresses have been exerted in so many different directions, owing to the coarsely crystalline and mixed mineral constitution of the rock, that the bands of Jacunze seldom exhibit any approximate parallelism, except in one and the same crystal. The bubbles contained in the liquid of many of these lacunee exhibit spontaneous movement. A bubble in one of the largest lacune shows this spontaneous motion very perfecthy, and the drawing (Pl. XX1I. fig. 8) roughly indicates the course which it followed while watched for about a minute. Occasionally well-formed tabular crystals of specular iron occur in the quartz. The apatite crystals lie within crystals of hornblende and quartz and also within patches of magnetite, and evidently represent the first-formed constituents of the rock. Pl. XIX. fig. 1 shows the coarsely crystalline character of this rock. On the right, a portion of a large crystal of hornblende is represented, with a few included crystals of apatite ; the remainder of the figure shows portions of felspar-crystals and some interstitial quartz. The rock is a foliated quartz-syenite or hornblendic granite. The paucity of mica, however, hardly entitles it to the latter name. Gneissic quartz-syenite is, perhaps, the most appropriate term to apply to it. No. 2. North Mill. Largest quarry. North face of the hill—A rather finely crystalline dark greenish-grey rock, with pale greenish- grey streaks varying from a millimetre to a centimetre in breadth. This banding is sometimes very even and parallel, the rock splitting more or less readily along the pale greenish bands. In places the bands are less regular and have a tendency to branch. Under the microscope the pale greenish streaks are seen to con- sist In great part of epidote, which has probably resulted from the alteration of hornblende. Some green magnesian mica is also present. The section contains one crystal in which the change of the hornblende has only been partially effected, portions still showing the characteristic cleavage and strong pleochroism. Much of the felspar appears, from the extinction-angles, to be labradorite. Quartz is present in irregular patches, and contains numerous fluid lacune, generally ranged in lines, which, however, do not correspond in direction in the different crystals. The section also shows some good crystals of apatite. There are some portions of the preparation, consisting possibly of cordierite, which have been altered into a mass of minute fibrous crystals, irregularly felted, and showing, although colourless, strong absorption of light. Their extinction indicates that they are rhombic, and it is probable that they are sillimanite or natrolite. Magnetite is present, but only in small quantity. OF THE MALVERN HILLS. AQ] An especially noteworthy point is the great difference in texture between this rock and the rocks with which it is associated. The latter are very coarsely crystalline and extremely rich in horn- blende. This rock, on the contrary, is of much finer texture, and one of its chief constituents is epidote, a mineral of secondary origin. The fibrous alteration-product already mentioned (sillimanite or natrolite) chiefly characterizes those particular bands in the section which give the foliated appearance to the specimen. There is no elongation of the quartz- and other constituent crys- tals to indicate that the banding of the rock is due to stresses and earth-movements, which in some cases are known to induce foliation and schistose structure in eruptive rocks, and it seems by no means improbable that this rock, in its earlier condition, possessed such banded structure as now exists in it (Pl. XIX. fig. 2), and that this banding resulted from the accumulation of hornblende &e. in certain planes *. These, I believe, were planes of stratification; and I am disposed to regard the rock provisionally as a highly altered sedi- mentary deposit or an altered and bedded volcanic tuff. Indeed, it seems very probable that in the earlier periods of the earth’s history, when sedimentary rocks must necessarily have formed a far smaller proportion of the earth’s crust than they do now, the products of denudation were chiefiy derived from rocks of an erup- tive type, and deposits formed of such materials would approximate more or less closely in mineral constitution to beds composed of truly volcanic ejectamenta. The sedimentary rocks of later date consist, in great part, of partially decomposed and triturated mate- rials derived from the repeated partial decomposition and trituration of rock, and there is, consequently, less probability now of the sedimentary deposits resembling volcanic tuffs than there was in Archeean times. The minute structure of the rock is not gneissic or schistose, and its fissile character is dependent upon the layers of epidote, which give itits banded appearance. No. 3. North Hill. Easternmost quarry on North side —This is a coarsely crystalline rock apparently consisting of black hornblende and flesh-coloured felspar, and in which traces of foliation are only perceptible in large specimens. Under the microscope the rock is seen to consist of hornblende, triclinic felspars, magnetite, and apatite. The felspars are mostly, if not exclusively, triclinic, and are, as a- rule, more or less altered by the development either of felsitic microcrystalline matter, or by minute scales, with here and there elongated negative crystals sometimes filled with decomposition-products. In one of these cavities a bubble is perceptible. All these results of alteration follow, as arule, the direction of twin-lamelle, aithough at times * Tn accordance with what is stated in the concluding pages of this paper, I may add that it is possible that such a rock might result from the crushing and chemical alteration of a diorite; and the proximity of diorite would lend support to this view. The microscopic evidence does not, however, appear to fayour such an hypothesis.—June 28, 1887. AQ? MR. F. RUTLEY ON THE ROCKS they pass in parallel lines across such lamelle without any accom- panying twin-lamellation ; and in such cases they sometimes appear as dark opaque rods, probably the edges of thin tabular crystals of minute dimensions. These alterations are evidently similar to those described by Prof. Judd under the term “Schillerization”*; and it would have been superfluous to figure them, since like examples are admi- rably delineated in pl. x., vol. xli. of this Journal. By reflected light some of these alteration-bands appear of a pale greyish-white colour ; they are more opaque than the unaltered parts of the felspar, and it seems highly probable that the minute SUES, which in great measure made up these bands, are kaolin. In one or two cases the felspar crystals appear o undergo parallel extinction ; and bearing in mind the low extinction-angles of some of the triclinic felspars, notably in basal sections of oligoclase and andesine, I have felt some doubt in referring such crystals to ortho- clase or to a micro-perthitic growth of that mineral with another felspar. There appears to be no perceptible change of tint when a Klein’s plate is employed, and it seems possible that the very regular parallel bands of decomposition-products may, in this case, be fol- lowing a direction of cleavage in a monoclinic crystal. Due pre- caution was of course taken to insure the accurate crossing of the nicols. I am, however, still doubtful whether these crystals can be regarded as orthoclase. Some of the felspars, indeed a large proportion of them, appear, from their extinction-angles, to be labra- dorite. Twinning on both the albite and pericline types may sometimes be met with in the same crystal. Little or no quartz is present, and the rock may be regarded mineralogically as diorite, petrologically as a gneissic diorite or hornblendic gneiss. The foliation of the rock is scarcely evident in the microscopic section, except in one or two places where the smaller hornblende crystals show a tendency to form short and irregular bands (Pl. XIX. fig. 3). The dioritic character of the rocks of the North Hill was duly recognized more than twenty years ago by Dr. Harvey B. Holl +. No. 4. North Hill. Kasternmost quarry, North end.—A very coarsely crystalline rock consisting of blackish-green crystals of horn- blende, ranging from a quarter of an inch in diameter to smaller dimensions, and flesh-red felspar. This is one of the most coarsely erystalline and profusely hornblendic rocks in the whole range. Under the microscope the larger proportion of the rock is seen to consist of hornblende in large crystals, which by transmitted light appear of a green colour. The pleochroism is strong and the cleavages are well defined. Their boundaries are, however, irre- eular, as are those of the felspar crystals. The latter have under- gone much alteration, so that it is difficult to ascertain their optical characters. Some of them, however, are plagioclastic and tolerably * “On the Tertiary and Older Peridotites of Scotland,” Quart. Journ. Geol. Soe. vol. xli. p. 376. t “On the Geological Structure of the Malvern Hills” &c., Quart. Journ. Geol. Soc. vol. xxi. p. 83. OF THE MALVERN HILLS. 493 fresh, while the majority show indications of twin-lamellation. Some crystals of apatite are present, and there is a little quartz containing fiuid-enclosures ; but the latter mineral forms only a very small proportion of the rock, just enough to entitle it to the name of quartz-diorite. Taking the coarsely crystalline structure of the rock into account, it should, perhaps, rather be termed a hornblende- gabbro. It does not appear to be foliated, and is probably an intrusive rock. Pl. XIX. fig. 4 shows portions of the large horn- blende and felspar crystals as seen by ordinary transmitted light and magnified 55 diameters. No. 5. North Hill, near the top, South side—A rather coarsely erystalline dark iron-grey rock, consisting apparently of hornblende and felspar crystals, the former being, as a rule, the larger. The specimen exerts a moderately strong attraction when brought near the magnetic needle. Under the microscope it is seen to consist of hornblende, triclinic felspars, magnetite, and apatite. The felspar, judging from its extinction-angles, is in most cases labradorite. It is considerably altered, as a rule, especially on the borders of the crystals where they abut against the hornblende, into a microcrystalline-granular material, probably felsitic. The magnetite occurs in octahedra and in irregularly-shaped patches, the apatite in well-defined crystals. There is no sign of foliation, either in the specimen or in the microscopic preparation. Quartz appears to be absent; and the rock may be regarded as a good example of a diorite. No. 6. North Hill (top).—A rather fine-grained, pinkish, granitic- looking rock, showing slight foliation. Under the microscope the section shows felspar, quartz, horn- blende, magnetite, apatite, and kaolin. The felspars appear to be, in part at least, triclinic, but as a rule they are much decomposed. A very little mica may be present. The rock is essentially a quartz-syenite or hornblendic granite (Pl. XX. fig. 1). There is no evidence to show that it is a meta- morphic rock. From its rather fine texture it may be regarded as an intrusive sheet or dyke of no great extent. No. 7. North Hill, just south of Ivy Scar Rock (bench-mark).—A very fine-grained dark-grey rock, resembling the whin of the North of England in general appearance. Under the microscope the felspars -show the twin-lamellation eharacteristic of triclinic felspars, and the greater number of the Sections give extinctions of between 5° and 6° and between 15° and 16°. Jt would appear therefore that the dominant, if not the only, felspar is labradorite. The other constituents are hornblende, mag- netite, and apatite. The apatite occurs in well-formed hexagonal prisms *, the hornblende in crystals which exhibit no regular boun- | daries, while the magnetite, which is plentiful, occurs in octahedra or in irregular patches. Some opaque white matter is also present; * ae group of seven individuals occurring in this rock is shown in Pl. XXI. wg. d. ee G.s. No. 171 25 A9QA. MR. F. RUTLEY ON THE ROCKS it results from the decomposition of the felspar, and is probably kaolin. The rock is a diorite (Pl. XIX. fig. 5). No. 8. Quarry just above West Malvern Church.—A greenish- grey gneissic-looking rock, with very minute micaceous scales. The rock varies in texture, pinkish felspar occurring in some of the bands in rather coarse crystals. Under the microscope the chief constituents are seen to be tri- clinic felspars, biotite, epidote, apatite, a little quartz, and several decomposition-products. The biotite appears, by transmitted light, to be mostly of a sea-green colour. The felspars often contain great numbers of crystals, frequently mere microliths, which undergo parallel extinction and are probably mesotype. The rock is a mica- ceous gneiss. No.9. Quarry just above West Malvern Church.—A foliated rock, consisting of flesh-coloured and narrow dark-greenish bands. The former appear to be chiefly felspar, sometimes showing crystals a quarter of an inch in length. Under the microscope the rock is seen to be composed of micro- cline in large crystals without any regular boundaries, and showing the characteristic crossed twin-lamellation very distinctly, with the usual extinction-angles ; quartz, biotite forming thin irregular bands which mark the foliation of the rock, a little epidote and irregularly shaped and sparsely distributed grains of magnetite or titaniferous iron, probably the latter, as the grains are sometimes surrounded by an opaque, yellowish-white substance, which may be leucoxene. In general terms the rock may be designated biotite-gneiss. The foliation is shown in Pl. XIX. fig. 6. No. 10. Large quarry (Leighion’s) at the mouth of the Dingle, between the Worcestershire Beacon and North Hill.—A fine-grained, bluish-grey, crystalline rock, resembling whin, and showing a few minute specks of pyrites. The specimen selected is an average sample of the stone now being quarried for road-metal. The rock strongly attracts the magnetic needle. Under the microscope it appears to consist of pale-green horn- blende considerably altered (but crystals occasionally give an extinction-angle of 19° from the vertical axis), biotite, lath-shaped crystals of felspar much decomposed, but some tolerably fresh, showing micro-pegmatitic structure, and others twin-lamelle in which the extinctions indicate labradorite. Magnetite is plentiful, and there is a little pyrites. The biotite is of a green colour; and it is a matter of some difficulty to distinguish between it and the — hornblende, as they are often intimately associated. The rock is apparently an altered mica-diorite (Pl. XIX. fig. 7). . No.11. Worcestershire Beacon. North side near the summit.—A very fine-grained pale pinkish-grey crystalline rock resembling elvan or granulite. Seen under a pocket-lens it appears to consist of pinkish felspar, quartz, and minute deep-red grains which are seemingly garnets. Under the microscope the constituents are seen to be those already enumerated. The grains composing the rock are all of them OF THE MALVERN HILLS. 495 irregular in form and appear to be bound together by a crypto- erystalline cementing material. The felspar appears to be orthoclase : the garnets are only to be recognized by their isotropy, while the quartz contains numerous fluid lacune, some of them with bubbles which exhibit spontaneous movement when examined under a power of about 800 linear. The rock is a granulite and, in common with rocks of this class, is remarkably tough under the hammer. Portion of a thin section as it appears between crossed nicols and magnified 55 linear is shown in Pl. XIX. fig. 8. No. 12. Worcestershire Beacon. North side near summit.—A granitic-looking rock, coarsely crystalline and apparently composed of quartz, pink felspar, and mica. Under the microscope the constituents are seen to be microcline, quartz, biotite, and apatite. Here and there a little lhmonite and specular iron occurs; one or two small crystals of hornblende may be seen, in which the angle c:c¢is exceptionally large, being over 30°. The pleochroism is somewhat distinct. The biotite, when examined under a tolerably high power, is found to be spotted with stains and patches of ferric oxide, and in some places scales of specular iron are developed. In other cases spicular bodies which, when magnified about 800 diameters, are seen to consist of strings of globulites massed in small fasciculi appear dark and opaque except towards their ends, where their component globulitic strings are irayed out and the globulites are seen to betranslucent. These globulitic crystals, for as such they may be regarded, probably represent an early stage in the development of some such mineral as hornblende. Furthermore, they intersect at angles of 60° in basal sections of the*bictite, and evidently lie in the directions of the three lines which form the percussion-figure of this mica. In sections normal or oblique to the cleavage of the biotite they appear merely as dark lines which follow the cleavage-planes. There is a certain resemblance in this arrangement which recalls the well- known crystals of specular iron in the Pennsbury mica, but the latter have sharply defined boundaries. Crystals and scales of specular iron also occur in the biotite of this Malvern rock, asso- ciated and sometimes in contact with the globulitic crystallites just described; but here, too, the specular iron exhibits sharply defined boundaries, and there is no doubt that whatever the globulitic bodies may be, they represent the incipient development of some mineral which retains any iron it may contain in the protoxide state, since the globulites are either colourless or pale green: but, since the surrounding biotite is of a green colour, it is difficult to say what their colour would be by transmitted light, if isolated. By reflected light the opaque portions of these crystallites, where the globulites have become densely packed, appear of a pale green or greenish white. A drawing of some of them, as seen by substage illumination and magnified 850 linear, is given in Pl. XXI. fig. 6. The rock is granite. Portion of the section magnified 18 linear _ is shown in Pl. XX. fig. 2. Zin 496 MR. F. RUTLEY ON THE ROCKS No.13. Worcestershire Beacon. North side of sumnut.—A greenish- grey crystalline rock, apparently composed toa large extent of horn- blende crystals varying from about 2 millim. to smaller dimensions. Under the microscope it is seen to consist of hornblende, decomposed felspars, apatite, and magnetite. The hornblende is very fresh. The cleavages are well defined and the pleochroism strong ; a= brownish- yellow, 6=dark brownish-green, c=bluish-green. ‘The felspars are in too advanced a stage of decomposition to admit of any determi- nation, but a few of them show faint indications of twin-lamellation. The magnetite occurs in irregular grains (Pl. XX. fig. 3). The rock is possibly a syenite, probably a diorite. The altered condition of the felspar precludes a decided opinion. No. 14. Worcestershire Beacon. Sumnut.—A crystalline rock apparently composed of dark green crystals of hornblende and pinkish-grey felspar. Under the microscope the constituents are found to be hornblende, triclinic felspars which show the extinction-angles of labradorite, apatite and magnetite. A little quartz is also present, but it certainly cannot be regarded as an essential constituent of the rock, which is a diorite. The section shows no traces of foliation. It is an erup- tive rock, and its general appearance en situ is that of a vertical dyke about 18 inches to 2 feet broad. Portion of a section magnified 18 LENCO | is shown im Pl. XX. fig. 4, as seen between crossed nicols. No. 15. Worcestershire Beacon. Nov side of summit.—A very fine-grained, pale bluish-grey crystalline rock. Epidote in small grains, triclinic felspar, quartz, and sparsely disseminated grains of Snaenetits appear, under the microscope, to be the chief constituents of this rock (Pl. XX. fig.5). Here and there a faintly defined linear arrangement of the epidote may be seen, as shown in the drawing, but it can hardly be regarded as foliation. The rock is probably an altered quartz-diorite, but it may, in its present condition, be looked upon almost as epidosite. No. 16. Herefordshire Beacon. North side, near top of ancient British Camp.—A fine-grained crystalline greenish-grey rock with small blackish-green porphyritic crystals. Under the microscope the latter are seen to be hornblende, and ragged fibrous-looking crystals of this mineral appear to constitute a large proportion of the rock and, from their arrangement, to give rise to a wavy and faintly foliated structure (Pl. XX. fig. 6). Minute granular crystals of epidote are plentiful, while patches of magnetite, often accom- panied by a little hematite, are common. The remainder of the section appears to consist of felspar, for the most part decomposed. Judging from the general appearance of the rock under the microscope, it seems highly probable that it is an altered diabase or andesite tuff; but it is also possible that the foliation in this, as in some other cases, may be due to shearing. No. 17. Herefordshire Beacon. North side, near top of British Camp.-—Dark bluish-grey to reddish-brown crystalline rock, show- OF THE MALVERN HILLS. 497 ing, on a cut surface, small reddish-brown and greyish-white blotches on a dark bluish-grey ground. Hornblende, triclinic felspars, quartz, epidote, apatite, and a little pyrites and chlorite appear, under the microscope, to be the principal constituents of this rock. Some of the felspars, judging from their extinction-angles, are labradorite, while others occasionally give an extinction-angle of 39°, and must consequently be referred to anorthite. The horn- blende appears of a pale green colour by transmitted light; it occurs in irregularly bounded crystals which show the characteristic cleavage. The epidote occurs in moderate-sized crystals and in small grains. The quartz has segregated so as to form distinct bands, which alternate with the very irregular bands of hornblende, epidote, &c., through which more or less quartz is also disseminated. It is difficult to assign any precise origin to this rock ; it might quite weil have resulted from the degradation of syenitic rocks or hornblendic gneiss. It may even be regarded as a fine-grained hornblendic gneiss, and it is to the latter rock that I am inclined pro- visionally to refer it. Its general appearance by ordinary transmitted light under an amplification of 18 linearis shown in Pl. XX. fig. 7. No. 18. Herefordshire Beacon. Close to and on the west of the Cave.—Rather coarsely crystalline dark greenish-grey rock resem- bling basalt. Under the microscope the constituents are seen to be augite, triclinic felspars, apatite, pyrites, and serpentine (Pl. XX. fig. 8). The crystals of augite are occasionally over 5}, inch in length. The characteristic, almost rectangularly-intersecting cleavages ay be seen in the basal sections. ‘The crystals are intersected by strong and very irregular fissures, frequently accompanied by peroxide of iron, which communicates a rusty stain to the augite for a slight distance bordering the cracks. Here and there erie scales of specular iron may also be seen lying within the substance of the augite. In sections parallel to 010 the measurements of the extinction ¢:¢ vary but little from 38°. These augite-crystals ) barely exhibit a trace of pleochroism. ‘The felspars show by their extinction-angles that some of them are labradorite, while others, and those perhaps the more numerous, are anorthite. The latter show, as a rule, less twin-lamellation than the labradorite, and the extinction-angle measured in four or five sections is 37° and some- times 38°. Pale green patches of serpentine are common in the rock and probably result from the alteration of olivine. No distinct forms which can be referred to crystals of olivine, however, are to be met with in the preparation. The pyrites occur in very irregularly-shaped patches often traversed by a labyrinth of channels and generally yery much cut up by branching cracks, which, when seen by reflected light, appear to be filled with hematite, while the pyrites is very ey seen to be intimately associated with magnetite, the latter mineral always enveloping the pyrites. From its mineral | constitution the rock appears to be related to eucrite. “An analysis of a rock from the same locality, no doubt the same 498 MR. F. RUTLEY ON THE ROCKS rock, has been given by the Rev. J. H. Timins (anal ysis xxxvii.* This analysis is subjoined, together with one of eucrite lava from Thjorsd in Iceland + :— eere : Tron . : Loss on Alkalies | Silica. econ Ora. Lime.| Magnesia. Ignition.| and Loss. —_——_—_| MPM sei | SOORVLL eee | 49°37 | 15°80 | 10°82 | 11°90 6°40 4:00 2°59— 99:98 -Eucrite ...... 49-60 | 16°89 | 11:92 | 13:07 7:56 . | 1°44 10048 | | In the first analysis traces of oxides of manganese and copper are recorded, and in the latter analysis traces of manganese, cobalt, and nickel. In the latter analysis, also, the iron is all in the protoxide condition, and the alkalies are given as Na,O=1°24 and i O—020 Mr. Timins = stated that the subject of his analysis contained a few grains of olivine and a little quartz in cavities. He also adds, ‘“* Parts of this rock resemble the matrix of the lava of the Capo di Bove near Rome. In its chemical composition it nearly corresponds with that which Bunsen gives for the ‘Normal Augite’§ of Iceland. Notwithstanding its occurrence in regular beds, its mine- ralogical character and its chemical composition make it probable that it has flowed over the surface.” | It is gratifying to find the mineral constitution of this rock, as revealed by the microscope, so well in accord with the results of Mr. Timins’s analysis made twenty years ago. The rock is eucrite- or anorthite-basalt. The eucrite lava of Thjorsa, the analysis of which I have here employed for comparison, is cited by Von Lasaulx || as an example of a true eucrite, and there seems, therefore, good reason to accept the analysis given by Kalkowsky as typical. The latter authority does not consider the term eucrite well chosen, and deprecates its use. No. 19. Herefordshire Beacon. East side, at the back of the Cave.— Very fine-grained bluish-grey aphaniticrock. Under the microscope it is seen to consist of felspars, chiefly labradorite, augite, titani- ferous iron, leucoxene, and pyrites in exceedingly minute specks. The section is traversed by a small vein of epidote enveloping fragments of the adjacent rock and also a little quartz. The augite appears in irregular grains, few distinctly formed crystals being visible. The felspars occur in lath-shaped crystals, generally corroded and frequently bent (Pl. XXI. figs. 4 & 5). There is much opaque * “On the Chemical Geology of the Malvern Hills,” Q. J. G. 8. vol. xxiii. . 008. : + Kalkowsky, ‘Elemente der Lithologie,’ Heidelberg, 1886, p. 150. t Op. cit. p. 359. § The name Augite was used synonymously with Basalt by some of the earlier writers, and is given, in this sense, by Kinahan, ‘ Handy-Book of Ro Names,’ London, 1873, p. 73. | ’ Elemente der Petrographie,’ Bonn, 1875, p. 316. OF THE MALVERN HILLS. 499 avhite matter in the section, which, as seen by substage illumination, is indicated by the darker parts in Pl. XX. fig. 9. This is probably leucoxene, and it is generally associated with an opaque black mineral, which may, consequently, be regarded rather as ilmenite than as magnetite. The rock is a basalt. No. 20. At the back of the Cave. Herefordshire Beacon, overlooking Castle Morton Common.—A compact pinkish-brown to pale liver- brown rock of felsitic appearance and not unlike some porcellanites, with splintery to small wavy, almost conchoidal fracture, harder than steel, harder, at all events in part, than quartz, since the brilliant pyramidal face of a quartz-crystal was distinctly scratched by sharp corners of the specimen. Under the microscope the rock is seen to be filled with minute, sometimes irregularly-shaped, but generally nearly spherical granules with apparently a somewhat high refractive index. The aspect of the section between crossed nicols is that of a felsite, and it appears that the feeble light transmitted under these conditions emanates from portions of the otherwise seemingly structureless parts of the ground-mass, since, as a rule, the minute granules are appa- rently isotropic. It is, however, difficult to speak positively as to their absolute isotropy. Here and there crystals ranging from -4, inch to smaller dimensions may be seen either isolated or in groups. They are colourless and prismatic in habit. They are traversed transversely to the axis of the prism by lines which may represent a rather irregular cleavage. Between crossed nicols they undergo parallel or straight extinction, and may belong to the rhombic system. I would very doubtfully refer them to topaz. a supposition which is strengthened by the analysis (xlii.) of the Rev. J. H. Timins* of a rock from the same locality, in contact with felstone, in which he detected one per cent. of hydrofluoric acid. An interesting point connected with this rock is an obscure perlitic structure. In the first section examined it was not sufficiently well marked to enable me to form a definite conclusion; but since, in another section off the same specimen, a similar but better-marked structure (Pl. XXI. fig. 7) has been observed, I no longer hesitate to describe the rock as a devitrified obsidian with perlitic structure. It may be _ the rock analyzed by Mr. Timins, No. xlii., described by him as felstone ‘‘ of a pink colour,” or No. xlv. “ Porcellanite, north-east of the cave” 7. It is probably the latter, but both analyses are here transcribed :— mg - _ | Oxide of | +. __. | Loss on | Alkalies | Silica. | Alumina. oe Lime. | Magnesia. ‘Ignition. land Loss. it. ......,4050 | 123 1:33 5°39 0-91 1:45 29 Pal i..03- 50 78°92 8:18 4°08 5:05 0°48 Pils) 2:10 * “On the Chemical Geology of the Malvern Hills,” Q. J. G. 8. vol. xxiii. p. 360. + Op. cit. p. 360. 500 MR. F. RUTLEY ON THE ROCKS The percentage of alkalies is, however, considerably lower than is- usual in rocks of this class. The perlitic structure is chiefly rendered evident by the massing together of the minute granules already alluded to along curved lines. This is indicated in the drawing which was made from a spot in the section which shows the structure best, as it frequently becomes very obscure, owing to the multitude of the granules, so that oftentimes no arrangement denoting perlitic structure can be traced. Even under favourable circumstances it is frequently needful to examine the section attentively before the fact that this structure is present and pervades the entire section becomes evident to the observer. The specimen was collécted and labelled as likely to show perlitic structure. It does show it, but it is the most feeble demonstration of the structure that I have ever seen. It is interesting, however, as being the first indication of a vitreous rock in the Malvern Range hitherto recorded, and it may possibly belong to the same geological horizon as the perlitic rocks of the Wrekin, first described by Mr. 8. Allport *. The specimen is a mere surface-chip, and further search in the neighbourhood from which it was derived would certainly yield better material for investigation and probably more satisfactory results. The apparent banding shown in P]. XXI. fig. 7 is merely due to alteration, produced by the filtering of water along cracks resulting in a slight rusting ; but these cracks, as shown in the drawing, have been faulted by other minute fissures. No. 21. Hollybush Pass. Large Quarry on North side of road.— Average sample of the stone now quarried. Very fine-grained bluish-grey crystalline rock, strongly attracts the magnetic needle. Under a pocket-lens it shows here and there a few scales of silvery mica. Its general appearance resembles that of very fine-grained whin. Under the microscope the rock appears to consist of altered triclinic felspars, biotite, magnetite, and various products of de- composition. The felspars, when their extinction-angles can be made out, are apparently labradorite. Numerous but very small apatite crystals are visible; epidote and chlorite are present. ‘The magnetite frequently occurs in octahedra, which now and then, by their reentering angles, are seen to have a parallel grouping. The general impression derived from an examination of this rock under the microscope is that it is a much-altered diabase. No. 22. Swinyard’s Hill. Commencement of North end of the ridge. —A yery coarsely crystalline rock consisting of red felspar in large crystals, a greenish mica in small scales, and quartz in crystalline pellets, occasionally nearly half an inch in diameter. Under the microscope the felspars are seen to be microcline and orthoclase, the former showing, in polarized light, the characteristi¢ twin-iamelle intersecting approximately at right angles, the angle of maximum extinction in basal sections being about 15° from the Quart. Journ. Geol. Soc. vol. xxxiii. p. 449. en eat a. a ee ee ee re ee Me te a ee OF THE MALVERN HILLS. 501 directions of the lamelle. The orthoclase also occurs in large erystals. One of those present in the section is twinned on the Carlsbad type. The mica is of a green colour by transmitted light and the crystals are much smaller than those of the felspars. The quartz encloses great numbers of fiuid-lacune containing bubbles. These cavities are mostly ranged in lines or streams which appear to follow two general directions crossing at a high angle, which, however, varies, as the lines are rather wavy and sometimes converge. By carefully traversing the preparation under the microscope it is seen that the directions of these streams of cavities are tolerably persistent in patches of quartz more or less widely separated, and it is possible that they may be approximately normal to two different directions of stress. The large patches of quartz are seen in polarized light to be made up of smaller patches, each being an individual quartz-crystal; yet the same stream of cavities will pass unbroken through many of these crystals, until, joming with other streams of cavities, it can no longer be traced, or until it reaches the opposite side of the composite area of quartz. None of the component minerals exhibit any definite crystalline forms. No apatite is present, but afew granules, apparently of epidote, are visible. The rock is a coarse-grained granite or pegmatite. No. 23. Swinyard’s Hill. Highest point of the ridge.—A coarsely erystalline rock composed apparently of dark-green hornblende and pinkish-grey to greyish-white felspar, with a few minute scales of a silvery mica. The chief constituent of the rock, however, appears to be hornblende in large crystals. Under the microscope the constituents are seen to be hornblende, triclinic felspar, a colourless mica, epidote, natrolite, and magnetite. Of these, hornblende is by far the most important, constituting probably more than three fourths of the rock. The felspars approxi- mate in their extinction-angles, in some cases to andesine, in others to labradorite; but the lamelle are often bent. They are by no means numerous, and exhibit no well-defined crystalline form. The mica is colourless or of a very pale greenish tint when viewed in thin section by transmitted light. Both epidote and magnetite occur in small irregularly-shaped grains. The natrolite is chiefly met with in the triclinic felspars, in small prisms which polarize in brilhant colours, and, between crossed nicols, undergo straight extinction. Here and there minute scales of specular iron of a bright orange-red colour may be seen in basal sections of the mica. In these sections only a portion of an hyperbola can be seen in convergent polarized light. The rock is a diorite, and was described as such by the late Dr. Holl*. The Rev. J. H. Timins has also described it in his paper T as “containing hornblende, white felspar and silvery mica. The more micaceous and felspathic portion of the rock was analyzed.” ‘The analysis is subjoined. * Op. cit. p. 77. Where he refers the felspar to oligoclase or andesine. tT Op. cit. pp. 363-364. Analysis lx. 502 MR. F. RUTLEY ON THE ROCKS Silica=44°76. Alumina=16:60. Oxide of Iron=8°43. Oxide of Manganese = 0°20. Lime = 9°92. Magnesia = 8°56. Loss on Jgnition=2°68. Alkalies and Loss=8°85. No. 24. Swinyard’s Hill. North side of highest point of ridge.—A remarkably coarsely-crystalline rock composed of flesh-red felspar, dark green hornblende, and quartz. This and No. 22 are perhaps the most coarsely crystalline rocks in the whole of the Malvern Range. Under the microscope by ordinary transmitted light the horn- blende appears of a greenish-brown colour, and some minute opaque brown flecks, seemingly of limonite, may here and there be seen in it. The felspar-crystals are mostly very large and exhibit no definite crystalline form, their boundaries being extremely irregular. Some of them are tolerably fresh, others considerably altered. One measurement gave an extinction-angle of about 5°, another, but not a trustworthy one, about 12°. They are probably microcline. The quartz contains fluid-lacune with bubbles. The rock is coarse hornblendic granite or quartz-syenite. No. 25. Swimyard’s Hill, North side of highest point.—A rather fine-grained, crystalline, dioritic-looking rock, apparently composed of dark green hornblende and a pale grey or pinkish-grey felspar. Under the microscope the hornblende appears to be the principal constituent (Pl. XX. fig. 10). It is of a brownish-green colour when viewed by transmitted light. Its pleochroism is strong, a=pale brownish yellow, b—coffee- brown, c=greenish brown. Where moderately fresh, the extinction-angles of the felspars indicate that they may be in some cases amdlesinie) in others labra- dorite; but for the most part the felspars are greatly decomposed, and no safe deductions can be formed concerning them, except that they are triclinic. They appear, in most cases, to be replaced by natrolite. Quartz, containing minute fluid-lacune, is of common occurrence in the section ; but the grains are small, and it forms a comparatively insignificant proportion of the rock, which must be regarded as a diorite. ‘No. 26. Swinyard’s Hill, just South of the swmmit.—A very dis- tinctly foliated crystalline rock, the bands being alternately flesh-red (or a finely crystalline admixture of fiesh-red and greyish-white minerals) and dark green, the constituent of the dark green bands being probably hornblende. Under a pocket-lens a few minute scales of silvery-looking mica are visible. The foliation reminds one somewhat of that of the Schorlschicfer of Auersherg in Saxony ; but in the latter rock the dark bands are intensely black instead of dusky green. Under the microscope, quartz, magnesian mica, and, apparently, some muscovite and triclinic felspars, especially microcline, are seen to be the principal constituents of the rock. The cleavage- planes in the mica have a general tendency to follow the foliation, which in reality is due to this mineral. The quartz shows streams of fluid-lacunee, which in nearly all cases run in a direction more OF THE MALVERN HILLS. 503 or less at right angles to the foliation. There is something more than accident in this circumstance. By reflected light, a rusty brown colour is seen to pervade the darker bands of the rock, and the darkness of these bands appears to be due partly to the presence of biotite, and partly to that of lmonite. The rock is essentially a biotite-gneiss. No. 27. Swinyard’s Hill, largest Quarry, South end.—Dark grey, finely foliated micaceous rock. On a cut surface, blotches and streaks of a fiesh-red felspar are visible. The rock has an imper- fectly fissile structure, and on the schistose planes the micaceous character is, of course, most perceptible. The description of the microscopic characters of the preceding specimen applies equally well to this, except that there is more muscovite present, and itis still noteworthy that the streams of fluid- enclosures in the quartz again run in a direction roughly normal to that of the foliation. The rock is a biotite-muscovite-gneiss. The foliated structure of this rock is shown in Pl. XX. fig. 11. No. 28. Ragyedstone Hill, Hastern Spur at top of hill near the middle, and at the northern end.—A fine-grained, greenish-grey, micaceous, schistose rock. Under the microscope, quartz, a little felspar, muscovite, and kaolin appear to be the principal constituents. The quartz occurs in grains and aggregates of grains, which have a lenticular form, and the mica scales lie in wavy films, which separate these lenticular bodies and impart a wavily streaked appearance to a section taken transversely to the schistose structure of the rock. These micaceous streaks are rendered more distinctly visible by an opaque yellowish- white substance which accompanies them, and is probably kaolin. Small scales of mica are also seen traversing individual grains of quartz. The quartz contains numerous fluid-lacune, and these, again, frequently he in streams which in most cases follow directions more or less steeply inclined to the general direction of the micaceous bands. The rock is a mica-schist. Its foliated character is shown in Pl. XX. fig. 12, where the darker markings represent the micaceous bands. No. 29. Swinyard’s Hill, large Quarry, South end, at foot of hill_— An essentially micaceous rock, in colour reddish brown to grey transverse to the direction of fission, but greenish grey, from the pre- dominance of mica, along the planes of fission. The fissile structure is very irregular. The microscope shows the presence of quartz, felspar, biotite, here and there a grain of magnetite, natrolite, and a very little limonite. Some of the felspar shows twin-lamellation, but it 1s nearly all in an advanced stage of alteration. It appears to be microcline, as a rule. The biotite is of a greenish colour, and runs in irregular bands. The quartz is in irregularly-bounded crystalline grains, through which run streams of fluid-enclosures at right angles or obliquely to 504 MR. F. RUTLEY ON THE ROCKS the direction of the micaceous bands, as already pointed out in the descriptions of specimens Nos. 22 and 26. ‘That the direction of _ these streams of enclosures is dependent upon causes operating sub- sequently to the formation of the quartz is evident from the fact that when the section is examined in polarized light the same stream of enclosures will be found to traverse without deflection several crystals which differ from one another in optical orienta- tion. The rock is a biotite gneiss. No. 30. Raggedstone Hill, Hastern Spur, North end, top.—A very fine-grained, pale, bluish-grey rock, resembling an exceedingly fine- grained quartzite. ‘The rock is very hard, a knife-point making littie or no impression on it. Under the microscope, between crossed nicols, the section presents a general appearance similar to that of the ground-mass of a quartz- porphyry, or of a rather coarse microcrystalline felsite, in which occur numerous porphyritic crystals of felspar and delicate strings and specks of more or less opaque granular matter, which, under reflected light, appears of a yellow-white or pale reddish-brown colour. Under a higher power, however, it is seen that the opacity of these strings and spots is only partial, and that in great part they consist of small translucent greenish or nearly colourless granules of epidote, with much fine dusty matter of a deep green colour, which appears to be allied to chlorite. The porphyritic felspar seems to be of a mixed character, the angles of extinction in some crystals being apparently very low, in other cases approxi- mating to those of labradorite. Microcline is also present. Some of the felspar may be andesine. The rock in some respects resembles granulite, but garnets are absent, and the felspar is all, or nearly all, plagioclastic. On the other hand, it is not unlike some felsites, especially some of the more coarsely micro-crystalline parts of certain devitrified rocks. I am, however, inclined to regard it as an altered sandstone derived from the disintegration of the older Archean rocks, and bearing the same relation to them that arkose or millstone-grit bears to granite. A drawing made from a section of this rock, magnified 25 diame- ters, is given on Pl. XXI. fig. 1. No. 31. Raggedstone Hill, Eastern Spur, North end, top.—A pale brownish-grey to bluish-grey rock, resembling quartzite strongly impregnated with very minute silvery-looking micaceous scales, and with a schistose structure. Under the microscope, in polarized light, this rock is seen to be essentially a quartzite, in which a schistose structure is induced by extremely thin micaceous or sericitic films. These are, in some instances, crossed by rather irregular and tolerably broad bands, consisting of quartzite of a much finer texture than that constituting the mass of the rock, and suggesting that another stress has been experienced in a direction approximately at right angles to that OF THE MALVERN HILLS. 505 which produced the schistosity of the rock. The quartz-grains, which are quite irregular in form, contain fluid-lacune, often ranged in lines, and these streams of enclosures le sometimes in the direc- tion of the fine-grained quartzitic bands, at others in the direction of the micaceous bands. The rock may not inaptly be termed a micaceous quartzite-schist. Part of a section of this rock is shown in Pl. XX. fig. 2, as seen by ordinary transmitted light. No. 32. Raggedstone Hill, Eastern Spur, East side, North end, near the middle.—A very compact, bluish-grey rock, translucent on the edges, resembling quartzite, with a faint laminated structure, and showing under a pocket-lens numerous minute, glistening, crystalline facets or cleavages. Under the microscope this is seen to be a quartzite containing numerous but very minute scales of mica, which, in places, show a tendency to segregate in irregular lines. They are not, however, sufficiently numerous in proportion to their size to impart a fissile character to the rock. No. 33. Vein, about a foot in thickness, in first quarry on South side of The Wych, Western side of the Malvern Range.—A very coarsely erystalline rock of a deep flesh-red colour, with spots of greyish or bluish-white quartz. Under the microscope the felspar appears to be microcline, the extinction-angle generally ranging from about 12° to 15°. The cross-hatched twinning on the pericline and albite types, so common in this mineral, is not to be detected in the section here described, the crystals showing but one set of twin-lamellz, and in some cases none. The crystals are sometimes cracked and faulted, as shown in Pl. XXI. fig. 3. Some opaque white matter, probably kaolin, is present in small flecks and streaks. ‘The quartz contains fluid-lacune, often showing a faint linear arrangement. ‘This is a good example of the pegmatite-veins so common in the Malvern Hills. Of their intru- sive character there can be no doubt. An admirable example of a branching vein may be seen traversing schists in an abandoned quarry on the east side of the Raggedstone and towards the southern end of the hill. J am not, however, inclined to think that the coarse pegmatite forming the northern part of the ridge of Swin- yard’s Hill is to be regarded as a vein-rock or dyke, or as a series of veins; it is more likely to be part of a deep-seated rock belonging to the lower, and probably to the lowest exposed portion of the Archeean series in this district. In reviewing the results of the microscopic examination of the Malvern rocks, we must in the first place separate those rocks which exhibit foliation or lamination, or of which the origin has been sedimentary, from those which show no such structure, and which must, without doubt, be regarded as eruptive. This is the more needful since much diversity of opinion exists concerning the inter- pretation which should be put upon the phenomena of foliation. ‘We shall by this means classify the rocks of the Malvern Range into 506 MR. F. RUTLEY ON THE ROCKS a banded and an unbanded series, and under the former will come the different varieties of gneiss. For my own part, I am inclined to regard the gneissic rocks of this district as probably being more or less altered volcanic tuffs, or as sedimentary rocks mainly composed of eruptive material derived from the disintegration of rocks of a dioritic or syenitic character. Reasons for and against the assump- tion of a sedimentary origin for these gneissic rocks have already been given in the first part of this paper, and a section through the Malvern Hills was appended, based upon the hypothesis that folia- tion in this district corresponded with structural planes which fre- quently mark lithological differences, and that these structural planes were possibly planes of stratification. We shall find, on comparing the results of the foregoing microscopic examination, that, except in that part of the range which lies south of the fault crossing Swinyard’s Hill, the rocks are of a mixed character, being partly foliated and partly devoid of foliation. In the following Table the rocks are placed in three columns, so as to diwide the eruptive, the foliated, and the probably and unquestionably stratified rocks :— | Eruptive. Foliated. Stratified. Nortiriaath 23... seats | Hornblende-Gabbro, | Gneissic Syenite,| Altered Tuff? | _ Diorite. | Gneissic Diorite. North Rh ese. see nee | Quartz-Syenite. | ‘North Hill (above West Malvern) ...............| Mica-Diorite. Biotite-Gneiss. North Hill (The Dingle) Mica-Diorite. Worcestershire Beacon Granulite?, Granite, Diorite, Epidosite ?) Herefordshire Beacon . * Eucrite, * Basalt,) Hornblendic Gneiss.|Diabase-Tuff ? . | * Devitrified Obsi-| | dian. Swinyard’s Hill ......... | Pegmatite, Horn-! Biotite-Gneiss, Bio- blende - Pegmatite,| tite, | Muscovite- t Diorite. | Gmeiss. Hollybush Pass ......... | Diabase. | Raggedstone Hill ...... Re PTRM eae sestere |Mica-Schist, Mica-| Altered Sand- | | ceous Quartzite-| stone, Quart- aii | | Schist. zite. t Rocks between a little south of the summit of the Worcestershire Beacon on to Winds Point were not collected. t Rocks of Midsummer Hill were not collected. tt Rocks of Keys End were not collected. * These occur in the eastern buttress of the Herefordshire Beacon, and are of Cambrian (?) age, ‘‘ Altered primordial rocks ” of Dr. Holl. — It is evident therefore that the above list gives only a very in- complete idea of the rocks constituting the whole length of the range. By reference to Dr. Holl’s paper, these gaps may, to some extent, be filled up, as already indicated in the first part of this communi- cation. rom the tabular classification just given, it appears that the North Hill consists partly of rocks which show no foliation, and which we must regard as truly eruptive, and partly of foliated rocks, OF THE MALVERN HILLS. d07 which in many cases are, I think, either altered tuffs or are com— posed of the débris of eruptive rocks rich in hornblende. The rocks of the Worcestershire Beacon appear to be mainly eruptive. Those of the Herefordshire Beacon are, I believe, chiefly gneissic ; but the exposures are not sufficiently numerous or good to enable me to say much on this point, and the time for more careful examination was wanting. The eucrite, basalt, &c., which I have classed with the general mass of this beacon, occur in a buttress of the hill, which, according to Dr. Holl, consists of ‘ Primordial rocks.” The northern part of Swinyard’s Hill is composed of pegmatitic or granitic rocks of varying coarseness. The altered diabase in the Hollybush quarry forms part of the southern end of Midsummer Hill. A vein of pegmatite, consisting in great part of a red felspar, is, at the present time, exposed in the lower part of the quarry. South of Midsummer Hiil we meet with fine-grained gneissic rocks, quartzite-schist, quartzite, and altered sandstones, which form, I believe, the highest and least altered part of this Archean series. The views advanced in the first part of this paper appear there- fore to be, as a rule, borne out by the microscopic examination of the rocks, except that those of a truly eruptive character are much more plentiful than I had at first imagined. The Malvern Range may, | think, now be regarded as part of an old land where denudation had laid bare certain plutonic rocks, and where volcanic activity was very great; for whether we look upon these gneissic rocks as beds of volcanic ejectamenta, or regard them as of sedimentary origin, there seems to be little doubt that they are composed of the minerals which constitute eruptive rocks, and there appears to be no reason to assume that the alteration of any ordinary sedimentary rocks, such as slates and sandstones, could have resulted in the development of such a vast amount of hornblende. It may be argued that there is no appreciable difference in much of the hornblende occurring in the foliated rocks from that in the adjacent and non-foliated syenites and diorites, and that it is there- fore probable that the foliation has been induced in truly eruptive rocks by earth-movements* ; yet, granting this, how comes it that all of the rocks are not foliated? The pressure or movement which would affect one bed would naturally affect those in its proximity ; yet we meet with great variety in these beds both in texture and in structural characters. The facts do not seem to me to bear out the conclusion that earth-movements, at all events in the Malvern Range, have begotten foliation, except, perhaps, on a very small scale. We know too little as yet of the rocks which are formed from the waste of districts composed mainly of eruptive materials. Whence come our hornblende-slates and schists, chlorite-schists, mica-schists, schorl-schists, &c., the constituents of which are either those of eruptive rocks or their alteration-products, such as epidote, * Such apparently bedded structure, accompanied by differences in texture, is described by Prof. Bonney, in his Presidential Address to this Society (1886), by the name pseudostromatism, which he regards as the result of ‘a crushing in situ of zones of the original coarse-grained rock.” 508 MR. F. RUTLEY ON THE ROCKS chlorite, limonite, kaolin, serpentine, &c.? Some would say that they result from the pressure-metamorphism of eruptive rocks. It is true that, in certain cases, slates of the ordinary kind may be found to graduate into mica-slates as they near an eruptive mass; yet is this the only way in which mica-slates and schists have been formed? Admit that it is, and we may at once grant that the eneisses and schists of the Malverns are but metamorphosed sedi- ments. It may be so: we have yet to settle the limits of meta- morphism. On the other hand, it seems well also to suggest the possibility that the materials resulting from the denudation of eruptive rocks go somewhere and form something, and that the resulting rock is consequently likely to resemble those from which its materials were derived, rather than a slate or sandstone. I there- fore venture the suggestion that the ynewssie rocks of the Malvern Hills may be composed of the detritus of eruptive rocks. It is even possible that in an early stage of the earth’s history there was little save rocks of an eruptive nature for the denuding agents to work upon, and, if such an assumption were true, these Archzan rocks would claim a far greater antiquity than if they resulted from the metamorphism of stratified deposits. Again, it is very difficult to say how far the movements which these rock-masses have experienced may bave influenced their litho- logical structure, and whether such movements have resulted in any of the effects attributed to shearing. That such action is implicated to a certain extent in the production of their foliation is highly probable; but how we are to distinguish between the crushing and rearrangement of crushed materials by lateral thrust and the ar- rangement of detritus by a sorting process (which may take place either in air, in the case of volcanic dust falling on land and rocks disintegrated and recemented in situ, or in water, in the case of volcanic dust and rock-detritus deposited in seas or lakes) it is very difficult to say. In either case we have triturated rock-matter, in which a banded arrangement of the constituents prevails. It must be admitted, however, that in the rocks of the Malvern Hills the foliation bears but little resemblance to the structure induced by shearing, the crystals and crystalline grains seldom showing any marked lenticular form, while there is but little resemblance, as a rule, to that pseudo-fluxion structure, described by Lehmann * and other observers, which is so characteristic of rocks which have been modified by a creeping movement along structural planes. My conclusion 1s, that the rocks of the Malvern Hills represent part of an old district consisting of plutonic and, possibly, volcanic rocks, associated with tuffs, sedimentary rocks composed mainly or wholly of eruptive materials, and grits and sandstones. That the structural planes in these rocks, sometimes certainly, at others possibly, indi- cate planes of stratification, and that the foliation in many cases, if not in all, denotes lamination, due to deposition either in water or on land surfaces, probably more or less accentuated or altered by * «Entstehung der altkryst. Schiefer.’ Bonn, 1884. OF THE MALVERN HILLS. ~ 509 the movements which produced the upheavais, subsidences, and flexures prevalent in the range. If the progressive development of organisms be admitted, we can scarcely consider that the Trilobites found in the Cambrian rocks represent the earliest forms of life, and, consequently, we may infer that earlier sedimentary deposits have existed in which still lower types would be found. Yet, putting Hozoon out of the question, if such fossiliferous deposits exist, where are they, unless so com- pletely metamorphosed that their life-history can no longer be de- ciphered? ‘This seems an additional reason for supposing that, in the Archean rocks we have metamorphosed sediments associated with the products of vulcanicity and with plutonic rocks. The observations embodied in this paper are necessarily very im- perfect. To unravel the structure of the Malvern Hills would be the work rather of a lifetime than of a few months. It should also be remembered that the whole Malvern chain is only about eight miles in length and barely three quarters of a mile in breadth in its broadest parts; that it is grass-covered throughout, save where outcrops occur or where quarries have been opened; and that these outcrops and quarries are not sufficiently numerous to enable an observer to work out the relation of the rocks to one another with any precision, except in a few places. It is therefore manifest that it would be unsafe to draw any general conclusions from such scanty data and in so limited an area, except provisionally and with great caution. APPENDIX To Part LI. The conclusions arrived at in this paper have necessitated some alteration in the interpretation of the structure of the Malvern Range, as illustrated diagrammatically in the section which was appended to Part I. (facing p. 488). The prevalence of quartz-syenite or hornblendic granite and the existence of true diorites and hornblendic gabbro indicate that, at all events in a considerable portion of the North Hull, the rocks are certainly eruptive. There seems also reason to believe that much of the mass lying between the Dingle and the summit of the Worces- tershire Beacon is also of a syenitic or granitic character, while it is highly probable that the granulite occurring close to the summit represents a marginal condition of the granite. Of the relation of the diorite to the granite and syenite I am uncertain; but it seems probable that the diorite flanks these rocks as at Cock’s Tor, Brazen Tor, and other localities in Devonshire, where gabbros and sometimes amphibolites rest on the flanks of the Dartmoor granite*. It is probable also that, in some cases, the diorite penetrates the granitic and syenitic rocks. Upon these considerations I venture to alter that part of the diagrammatic section appended to Part I. which lies between the northern end of the range and the Wych, as in the annexed figure (fig. 4); but it must be remembered that this altered * “The Hruptive Rocks of Brent Tor,” Mem. Geol. Survey, p. 15. OG. s. No. 171. 2 510 MR, F. RUTLEY ON THE ROCKS version is still hypothetical, and is not the outcome of any detailed fieldwork. Fig. 4.—Hypothetical Section through the North Hill and the Worcestershire Beacon. ae $F i; YY YY ; YY GS fey) < UM Worcestershire Beacon. North Hill. g=Granite. d=Diorite. md=Mica-diorite. =Granulite. = Hornblende- gabbro. s=Gneissic rocks. EF K=Faults. The dotted lines indicate the relative positions of the rocks prior to faulting. The rock marked Granite, g, is really a very hornblendic Granite or Quartz- syenite. It may also be desirable to alter that part of the section which lies between the Herefordshire Beacon and the Raggedstone, treating the northern part of Swinyard’s Hill as part of a possibly once deep- seated mass of granite or pegmatite faulted in among newer rocks. The late Dr. Holl was of opinion that this part of Swinyard’s Hill was chiefly composed of granitic veins *, and it is quite possible that he may haye been right, since he mentioned gneissoid rocks, horn- blendic gneiss and schists as occurring with the granite. His observations in this locality were much more detailed than my own, yet I must admit that this portion of the ridge did not appear to me to consist of veins, and he himself seems to have felt consider- able doubt upon this point, as evidenced by the expressions “ Granite, probably a vein,” ‘ Granite vein ? ” The rocks north of this fault crossing Swinyard’s Hill and forming the highest part of the ridge appear to be coarse hornblendic granite or quartz-syenite, diorite, and gneiss. The diorites occur on either side of the coarse-grained quartz-syenite, as roughly indicated on the section (fig. 3, facing p. 488), and the contact of similar rocks in the Worcestershire Beacon and North Hill is worthy of note. The southern part of Midsummer Hill also shows an intrusive or else an interbedded diabase, probably the former. *: Op. cit. Pp: Ue OF THE MALVERN HILLS. 511 With these exceptions, [ am disposed to let the remainder of the section (appended to Part I.) stand as it is for the present, since it is merely intended to represent diagrammatically what may be, and is based upon a very limited foundation of observed facts. The foliated finely-crystalline gneiss, micaceous schists, and quart- zites in the south of the range appear to represent a series of altered and probably once-stratified rocks, such as sandstones, and micaceous and felspathic grits, and these graduate, as we pass northwards, into gneissic rocks, which probably represent coarse tuffs and detrital deposits, composed almost wholly of materials derived from the waste of plutonic rocks. These are associated with plutonic rocks of similar mineral constitution, probably in some cases of a later date, but-still of immense antiquity. It may also be a point of some significance that in what is here regarded as the Lower gneissic series we have hornblende in great quantity; in the Middle series the rocks become partly micaceous and partly hornblendic ; while in the Upper gneissic series, horn- blende is almost or totally absent, and the rocks in the lower part of this Upper series are very micaceous. The mica, however, becomes less and less plentiful as we pass southwards, until, in the upper part of this Upper series, it is present either in very small quantity or disappears altogether, as in the quartzites. There is, in fact, as we pass from the north to the south of the Malvern Range, a diminution in the percentage of those minerals which have the greatest density. Although in this paper it is assumed that the rocks of the Malvern Hills are partly eruptive and partly detrital, the latter showing under the microscope no distinct pseudo-fluxion structure such as would be expected in cases of well-marked pressure-metamorphism, yet it is quite possible that the foliation in some of these rocks may be due to the latter cause. One of the strongest arguments in favour of such an hypothesis is that foliated or gneissic diorite is here and there found in contact with non-foliated diorite, while gneissic quartz-syenite also occursin contact with quartz-syenite in which no foliation is discernible. That the mass which constitutes the main ridge of the Malvern Hills has experienced repeated movements and dislocations coupled with great stresses there can be no doubt. Hence there is strong probability that pressure-metamorphism has had some share in de- veloping the minute structural characters of these rocks. Distinct evidence upon this point seems, however, as yet, to be wanting ; and therefore, although willing to make all due concession to the advo- cates of pressure-metamorphism, on the production of sufficient proots, I am for the present disposed to hold by the opinions which I have already stated, modifying them only to the extent here indicated. There are probably many exposures of rock, south of the Worces- tershire Beacon, which the limited time at my disposal prevented me from visiting, nor am I sure that, among the specimens which [I collected, there may not be many which would present fresh points of interest if examined microscopically. In those which have been Zu 2 es Ie MR. F. RUTLEY ON THE ROCKS so examined there may also be some minerals which I have failed to recognize. Mr. Teall informs me that he has detected sphene in some of the rocks of the North Hill, and I am by no means certain that, in one or two of the sections prepared from specimens collected at the southern end of the range, rutile is not present. The opinions frequently expressed concerning the species of the felspars must also be accepted, in some cases, with a certain amount of reserve, since the measurement of the extinction-angles was often made from imperfectly developed crystals in which the directions of the planes of section were extremely doubtful. Under any circumstances the paper does but very imperfect justice to the various points discussed in it, and there still remains in these Archean rocks a vast and comparatively unexplored field for the exercise of the hammer and the microscope. EXPLANATION OF THE PLATES. Puate XIX. . Gneissic quartz-syenite. North Hill. x 18. (Specimen no. 1.) 2. Epidote-plagioclase rock. Probably an altered diorite-tuff. North Hill, x 18. (Specimen 2.) . Coarsely crystalline and slightly foliated diorite or hornblendic gneiss. North Hill. x 18. (Specimen 3.) . Coarsely crystalline quartz-diorite or hornblende-gabbro. x 55. The drawing shows portions of crystals of hornblende and orthoclase. (Specimen 4.) . Diorite. Ivy Sear Rock, North Hill. x 25. (Specimen 7.) : aE Sa Quarry aboye church, West Maivern. x 55. (Speci- men 9.) . Altered mica-diorite. Large quarry (Leighton’s) at mouth of the Dingle. X18. (Specimen 10.) . Granulite. Worcestershire Beacon, near top, north side. x 55, pola- rized light, nicols +. (Specimen 11.) el 0g be He 9 CO I Do PuatE XX. Fig. 1. Quartz-syenite or hornblendic granite (feebly foliated ?). Top of North Hill. x 25. (Specimen Gar 2. Granite. Worcestershire Beacon, near top, notte side. X18, nicols +. (Specimen 12.) 3. Diorite ? (syenite?) (felspars much decomposed). Worcestershire Bea- con, top. xX 18, nicols +. (Specimen 13.) 4, Diorite. Worcestershire Beacon, top (? dyke). X 18,nicols +. (Spe- cimen 14.) 5. Epidosite (altered quartz-diorite). Worcestershire Beacon, top, north side. X 18. (Specimen 15.) 6. Diabase-tuff (? foliation due to pressure-metamorphism). Herefordshire Beacon, north side, near top of ancient British camp. X 25. (Speci- men 16.) 7. Hornblendic gneiss. Herefordshire Beacon, north side, near top of ancient British camp. X 18. (Specimen 17. ) 8. Eucrite or anorthite-basalt. Herefordshire Beacon, close to and on : west of the cave. x 18. (Specimen 18.) . Basalt. Herefordshire Beacon, east Bide, at back of the cave. x 5, (Specimen 19.) OF THE MALVERN HILLS. 513 Fig. 10. Diorit2. Swinyard’s Hill, north side of highest point of ridge. x 18. (Specimen 25.) 11. Biotite-muscovite-gneiss. Swinyard’s Hill, largest quarry, south end. x 18. (Specimen 27.) 12. Mica-schist. Raggedstone Hill, east spur, top of northend. x 18. (Specimen 28.) Puate XXII. Fig. 1. Altered felspathic sandstone. Raggedstone Hill, top, east spur. x 25. nicols +. (Specimen 30.) 2. Quartzite-schist (micaceous). Raggedstone Hill, top, eastspur. X 25. (Specimen 31.) 3. Microcline-crystal (crushed and faulted) in granitic vein. Quarry close 2 and on south-west of the Wych. xX 30, nicols +. (Specimen 3.) 4 & 5. Corroded and bent erystals of triclinic felspar in basalt. Here- fordshire Beacon, east side, at back of the cave (see also fig. 9, Pl. XX.). x 55, nicols +. (Specimen 19.) 6. Globulitic crystallites in biotite of granite. Worcestershire Beacon, north side, near summit. X 850. (Specimen 12.) 7. Devitrified obsidian, showing perlitic structure and faulted band. Herefordshire Beacon, back of the cave, overlooking Castle Morton Common. X 55. (Specimen 20.) 8. Diagram showing track of spontaneously moving bubble in fluid-lacuna in quartz of gneissic quartz-syenite. North Hill. (Specimen 1.) 9. Group of apatite crystals in diorite. North Hill, just south of Ivy Scar Rock. Xx 350. (Specimen 7.) Note. —When not otherwise specified, the figures are represented as viewed by ordinary transmitted light. Discusston (December 1, 1886). The Present said that it was satisfactory that the Author had been able so completely to confirm Dr. Holl’s work. The three issues raised in the paper would probably meet with a varying amount of acquiescence on the part of the members :—(1) that these rocks are metamorphic, and not igneous, few would contest ; (2) there might be a difference of opinion as to the significance of the apparent succession ; (3) he anticipated a debate on the relation of foliation to sedimentation. Prof, Bonney would abstain at so late an hour from discussing the general question of foliation. Some years ago he had made a collection of these rocks, as also had Mr. Allport, who, he trusted, would yet publish the results of his investigation. He would now only ask :-— (1) Had the Author detected any indications of schistosity along planes of mineral banding ? (2) Is there any strong proof of mechanical disturbance productive of cleavage-foliation ? (3) Lastly, in studying the structure of the more coarsely crys- talline rocks, had he come upon those curious structures which occur in the oldest known gneisses, or upon those distinctly characteristic 514 MR. F. RUTLEY ON THE ROCKS of igneous rocks, and were they in any way modified by meta- morphism ? If these Malvernian rocks are gneisses of true Laurentian types, he would find them exhibit certain modifications in passing upwards. Mr. Tratt said that the Author had described a number of facts which any theory of the district would have to account for. What is the significance of the principal structural planes? This was the question which must be solved before any advance in the theoretical interpretation of the district could be made. ‘The Author appeared inclined to think that these planes were originally planes of strati- fication ; otherwise no conclusions as to age could be drawn. The coarsely crystalline rocks were igneous rather than sedimentary in aspect. He thought they might be igneous and of plutonic origin. The Presrpent observed that both the great longitudinal fault and also the cross faults were of later date than the foliation. The Avtuor, in reply, said that the President had indicated with great clearness the lines which the discussion should take. He agreed with him concerning the age of the faults; the amount of their throw is difficult to determine. Had he known of the in- tention of Prof. Bonney and Mr. Allport to take up this subject he would have abstained from the task. , Not having fully examined his slides, he was unable to answer questions relating to the micro- scopic characters of the rocks. He had found no particular evidence of mineral reconstruction along divisional planes. Difficult to say whether these rocks were or were not igneous; they are very like some igneous rocks and yet with a rude foliation. He then spoke of the different meanings attached to the word metamorphism. Judging from hand specimens, the Malvern rocks seemed to resemble those from the Hebrides and Canada. He had little doubt that the fine-grained schists were sedimentary, as they even contained beds of quartzite. He admitted that, according to the meaning given to the section, the great planes must be taken as bedding- planes. If the rocks were igneous, then the divisions into upper, middle, and lower groups had but little meaning. There may have been interbedded lava-flows. He had never met with divisional planes of such an even and persistent character in undoubted plutonic rocks. The divisional planes, rudely parallel to the sur- faces of granitic masses, such as those described by Boase and De la Beche, were far less regular. Discussion (April 6, 1887 *). The Presmpent observed that the Society did not often enjoy the advantage which they had that evening, of hearing papers on the same locality by two authors who looked at the subject from dif- ferent points of view. * This Discussion relates also to Dr. Callaway’s papers on the Rocks of Galway and the Malvern Hills, pp. 517 and 525. OF THE MALVERN HILLS. 515 Mr. Tratt said that Mr. Rutley had described a number of im- portant facts, but was very guarded in his interpretation of them. Dr. Callaway offered solutions of many of the problems. The pas- sage from felsite into a variety of mica-schist was of great interest. He agreed with Dr. Callaway, that crystalline schists and massive igneous rocks of similar chemical composition are frequently found in association with each other. He also agreed with Dr. Callaway as to the origin of certain banded gneisses. Granitic and dioritic rocks might be seen in one part of the Lizard to vein each other in the most intricate manner. It was possible to trace the veined series Into a banded gneissic series without a break. He regarded the banded gneissic series as the result of the deformation of a complex mass of plutonic igneous rock, and this was the view he understood Dr. Callaway to maintain with reference to some of the Malvern gneisses. Dr. Hicks said that the two views were nearer than would appear. Kach admitted that there was a granitoid rock in the centre, with dioritic rocks on the flanks, both igneous. To a certain extent these conditions are similar to what is found in some parts of Scotland, where, associated with granitoid rocks, there is a series of schists and eneiss. He was disposed to incline towards Mr. Rutley’s view, that there is a series of some kind, probably as in the Pebidian—a vol- canic series—where pressure had produced schistosity in parts even of the intrusive rocks, but not in the great masses. Dr. Callaway speaks of a felsitic rock converted into mica-schist ; from this view he was inclined to differ, as some of the specimens exhi- bited as converted into mica-schists should be classed rather as schistose felsites, as the felsitic structure is not destroyed, and the mica occurs as a secondary product along the cleavage-planes, mainly as the result of infiltration. The Archzean rocks may be, in the main, of igneous origin, but they contain also detrital and chemical deposits. Col. McMavon asked Dr. Callaway whether the foliation ,of a certain mass shown on one of the diagrams had been produc d by intrusion, by pressure previous to consolidation, or by pressure sub- sequent to consolidation, and, if subsequent, how he accounted for the granite showing no foliation at all. Dr. Cattaway expressed himself unable to explain Mr. Rutley’s diagrams, and Mr. Ruttry stated that the section through the North Hill was hypothetical. The PrestpENT commented on the different inferences drawn from the same set of facts. In the North Hill there are rocks not foliated and others greatly foliated. To Mr. Rutley this afforded the strongest proof of difference of origin, whilst Dr. Callaway saw gradual transitions from one to the other. The attempt to explain the formation of schists from volcanic rocks of an acid character had not been made before in this country. Mr. Rurtzy, in reply, was at a loss to recognize the position of Dr. Callaway’s section, He remarked that the foliation in these 516 ON THE ROCKS OF THE MALVERN HILLS. rocks appears to be restricted to bands. He referred to a diagram in a recent publication by Mr. Mellard Reade, which proves that flexure cannot take place without great trituration of the inter- vening mass, and he considered that such a cause had produced a certain amount of foliation. He commented on the opposite views expressed by Drs. Hicks and Callaway with reference to the alleged conversion of felsitic rocks into mica-schists. A case parallel to one of the instances of foliation mentioned by Dr. Callaway may be met with on the west of Dartmoor. Dr. Cattaway, in reply, congratulated himself on having had the support of Mr. Teall. Replying to Dr. Hicks’s remarks, he held that there was a true passage between felsite and mica-schist ; but this was a matter of field-observation, and could not be decided in that room. He did not see how a succession could be made out of hypogene igneous rocks. How the localization of pressure was effected he could not tell. There is a foliation, whether local or general. The section queried by Mr. Rutley is half a mile north of the Wych. 25 ite nas Vay SAAR ¥ ae hie as SINS, ERA fa. — kh ama) a fx] 25 i | } in U TLE AF: id ROCKS FROM Quart.dourn.ueol. 0oc. Vol: ALIN. FL. AA. © ? ] =. x 18. ye pa : + See PRE et 10. x18. c j ~ Mintern Bros Meroe ROCKS OF THE MALVERN RANGE. La % Ea Wie ae r . u j i J * * t Quart. Journ. G Lay i te ROCKS OF THE MALVERN RANGE. CONVERSION OF CRYSTALLINE SCHISTS INTO IGNEOUS ROCKS. 57, 36. On the AttEGED CoNvERSION of CrystaLtIneE Scuists into Ienzous Rocks in County Gatway. By C. Catzaway, Ksq., D.Se., F.G.8. (Read April 6, 1887.) INTRODUCTION. . General Distribution of the Igneous Rocks. . The Relations of the Igneous “Rocks to each other and to the Schists. Knockseefin, Ground south-east of Glendalough, Lettershinna, Ground south of Glendalough. be 3. The Foliation of the Igneous Rocks. _ The Granite. The Diorite. Veins of an Acidic Rock. 4, Age of the Igneous Rocks. 5. The Galway Gneiss. 6. Summary. INTRODUCTION. Tue theory of the metamorphism of aqueous deposits into granite and other igneous rocks has been maintained by most Irish geologists, and is set forth with much detail in the elaborate memoirs of the Trish Geological Survey * on the district between Galway and Westport. It therefore seemed to me, after some preliminary work in Donegal, that the Connemara region would probably afford rich material for the determination of the question. In this hope I was not disappointed; but while working at the relations between the igneous and the metamorphic rocks, another problem, the origin of the schists themselves, began to emerge. The result of my inquiries was a singular reversal of the theory I was exam- ining. I found, not that the igneous rocks had been formed out of schists, but that some, at least, of the schists had been formed out of igneous rocks. ‘The Galway region has, indeed, been most fruitful in suggestion, and has supplied me with a clue to the origin of some of the less complex oneisses. I have to acknowledge my obligations to Prof. Bonney, F.R.S., who has been kind enough to look through my microscopic slides, and to give me his opinion on critical points. In discussing the origin of the igneous rocks, it will be desirable to state briefly the evidence upon which the theory of the Irish Survey has been based. I will give the chief points, as far as possible, in the words of the Survey Memoirs ¢. Of the granite there are three types—Intrusive, Porphyritic, and Foliated. The porphyritic passes into the porphyritic-foliated, and the latter sometimes gradually loses its porphyritic character, and seems to pass into gneiss and schists. Itis inferred as probable that the foliation of the granite points to its original stratification and that even the porphyritic granite was originally part of a sedimentary series ; but being nearest to the “ seat of metamorphic action,”’ “ all * To accompany sheets 93, 94, 95, 104, 105, 1138, 114. + Quart. Journ, Geol. Soe. vol. xli. p- 221, ¢ Memoirs 105 and 114, pp. 7-16 e¢ alidz. 518 DR. C. CALLAWAY ON THE ALLEGED CONVERSION OF or nearly all traces of foliation which succeeded the stratification ”’ had been obliterated. In the “ metamorphic sedimentary rocks” are “ conglomeritic beds,” “containing large and small blocks, sometimes sparingly scattered through the mass, but often thickly together.” When the blocks are scattered they are considered to be due to a nodular structure in the original rock; but when numerous, the rock is regarded as ‘metamorphosed conglomerate.” Of the numerous varieties of igneous rocks described in the Survey Memoirs, [ shall usually be able to confine myself to two, granite and diorite. The granite is either uniform in grain or porphyritic, and either kind may be foliated. The diorite is generally a dark- green coarsely crystalline rock without varietal differences of importance. For the purposes of this paper, it will be unnecessary to notice minute distinctions. 1. GeneRAL DistRIBUTION OF THE IGNEOUS Rocks. The granite forms an extensive area reaching from the town of Galway all along the northern side of Galway Bay to the open Atlantic, and broadening out towards the west to a width of nearly 20 miles. It also appears in irregular intrusions amongst the schistose rocks to the north of the main mass. The most prominent exposures of the diorite are dotted at intervals round the northerly margin of the chief granite mass, either at a little distance from it or in actual contact with it. 2. Tue RELATIONS OF THE IenEovs Rocks TO EACH OTHER AND TO THE SCHISTS. Knockseefin. This hill lies nearly 4 miles to the south of Oughterard, and close to the margin of the chief granite-mass of the region. This is stated * to be the typical locality for witnessing the passage of eranite into schist. The ground is covered between the granite and the eneiss of which the hill is chiefly composed. The latter rock is a mica-gneiss of coarse grain, but clearly banded, weathering on strike-surfaces in fine parallel raised lines. The foliation-planes strike to the N.W. Towards the summit, nodules of diorite, lenticular in horizontal section, made their appearance in the gneiss, their longer axes running with the strike. These are apparently the extremities of veins which have been flattened by pressure. The diorite-nodules (veins) increase in number towards the top of the peak, and at the very summit the rock is nearly all diorite. Granite here comes in, irregularly penetrating the diorite. ‘The latter displays a sort of nodular jointing, the joint-blocks running in a roughly linear manner to the N.W., while the granite in * Kinahan’s ‘ Geology of Ireland, p. 190. CRYSTALLINE SCHISTS INTO IGNEOUS ROCKS IN CO. GALWAY. 519 places finds its way along the joints, forming a cementing matrix. The mixed rocks thus present a superficial resemblance to a con- glomerate. It appears from this section that the diorite is intrusive in the gneiss, and the granite in the diorite. It would also seem as if the diorite had consolidated and acquired a jointed structure previous to the introduction of the granite. How this ground affords evidence of a passage from granite into schist, I am unable to understand. Ground south-east of Glendalough. The singular phenomena [ am about to describe occur at the eastern end of a long band of ‘‘ hornblende-rock,” which runs in an east and west direction for a mile anda half. We here see all the steps of the process by which igneous rocks have been converted into a pseudo-conglomerate. The prevailing rock is diorite, with a very distinct jointing. On the weathered surfaces the material along the joints has yielded to degrading influences, so that the blocks between stand out in relief. These joint-blocks have a diameter varying between a few inches and perhaps two feet. In shape they are sometimes roughly oval or ovate, but frequently they are partially angular or subangular. Some of them are represented in figs. 1-3. There are in this locality several outcropping masses, some of which consist of unbroken diorite. In others, the following appear- ance is observed. For some yards, we pass the jointed diorite ; then we see a gradual coming in of the granite. ‘Thin veins find their way along the joints, in one place coming to an end against a joint-block (fig. 1), and in another, where the joints narrow, termi- Fig. 1.—Section of Granite in Jointed Diorite. nating between adjacent blocks. Not far off we see veins creeping along each side of a block, but failing to force their way entirely round (fig. 2); while close at hand the granite has succeeded in entirely isolating the blocks from the main mass, so that diorite is immersed in granite. It is therefore clear that these pseudo-con- glomerates are merely agglomerations of joint-blocks imbedded in a 520 DR. C. CALLAWAY ON THE ALLEGED CONVERSION OF ground-mass of granite. For these mixtures of hypogene rocks, the term “ diglomerate ” * may be suggested. Fig. 2.—Section of Granite in jointed Diorite. KIRN Lettershinna. Some interesting facts in confirmation and expansion of the pre- ceding observations occur in this hill, which lies two and a half miles south-west of the last locality, and therefore much nearer the granite massif. Lettershinna is a ridge running east and west in accordance with the strike of the region. It is mainly composed of granite; but near and at the summit are some masses and blocks of included diorite. On the north-western slope, I observed an oblong block of diorite immersed in the granite. The fragment was about a yard long and eighteen inches broad (fig. 3). The microscope shows the Fig. 3.—Section of Diorite in foliated Gramite. hornblende of this diorite to be clear and well crystallized; but the felspar is cloudy, and has apparently undergone partial decom- position. At the distance of about a foot was a smaller block of a roughly ovoid shape. That these are true inclusions, and not cross sections of veins, may be seen a little higher up the hill. Here a block of diorite is exposed in the face of a cliff, the foliation of the granite curving round the block both above and below it. Near the summit of the hill the diorite occurs in larger masses. Some of these are fringed by one or more outlying bands arranged roughly parallel to the margin. In one place there were three of * « di-.” because the blocks are forced asunder. CRYSTALLINE SCHISTS INTO IGNEOUS ROCKS IN CO. GALWAY. Bt these (fig. 4); in another, only one. Sometimes they are mere flakes. They are isolated from the main masses and from each other by granite. It would appear as if they were separated from the parent blocks by exfoliation. As the granite rose up between the blocks, Fig. 4.—Section of Diorite (? exfoliated) in Granite. they would become strongly heated, and the outer zones, being hottest, would by their greater expansion split away concentrically. That the exfoliated fragments retain their parallelism to the adjacent margin of the main masses is a.remarkable fact, to which I shall return. Ground south of Glendalough. Leaving the hotel in a southerly direction, we pass over crystalline limestone, quartzite, and a considerable thickness of hornblende- schist. A little further south lies a large mass of rock, chiefly hornblendic, which is said to “‘ graduate into the associated gneiss and schist” *. Near where “=” is marked on the map, there is a singular entanglement of schist with granite and diorite. The rocks are heavily glaciated, so that it was impossible to obtain large specimens; but even the small fragments collected clearly show that there is no passage between the schists and the igneous rocks. The schists are intensely contorted and much shattered, and the granite or the diorite sometimes finds its way even between adjacent folia, and is mixed up with the schists in inextricable confusion. Several contact-specimens have been microscopically examined, and Prof. Bonney, at my request, has devoted special attention to them. He thinks there is no doubt that they are a case of intrusion of granite into a fibrolite-schist ; but the structure of the granite is irregular and peculiar, owing probably to its contact with the schist. Tt is a striking fact that, in this locality, detached folia, or bundles of folia, frequently preserve an approximate parallelism to the foliation of the adjacent schists. This might appear to be a strong piece of evidence in favour of the metamorphic hypothesis. It is not easy to believe that an igneous rock could have been intruded amongst masses and fragments of schist without destroying the parallelism of strike. I would, however, venture to urge that the * Survey Memoir, 93, 94, p. 139. 522 DR. C. CALLAWAY ON THE ALLEGED CONVERSION OF facts furnished by the Lettershinna sections greatly attenuate the difficulty. If I am right in my reading of those sections, it is clear that the granite has intruded between the strips of diorite and pushed them apart, without materially disturbing their parallelism. But if we reflect upon the probable conditions under which the granite was intruded, even the original difficulty will not appear so great. The displacing power of an intruding current of molten matter will be in proportion to the rapidity of its motion. Dykes of greenstone intruded into faults often contain numerous pieces of fractured rock lying pellmell. But an igneous rock forced along lines of least resistance by tangential pressure may be expected to move with extreme slowness, so that the currents might act rather in the manner of slowly moving wedges than with the irregularity of an ordinary flow. Another consideration appears to me of still greater weight. The region under discussion has been subjected to great pressure. If, then, a number of flattened pieces of schist were scattered pellmell through the plastic mass of granite, the compressing force would move the fragments into planes lying at right angles to its own direction. We are familiar with a similar result in the formation of slates, and we may safely infer that the process would be facilitated by the plasticity of the granite, 3. Tue FoLtarion oF THE IgnEous Rocks. The Foliation of the Granite. The foliated structure is well seen in the district south of Glen- dalough. In one spot, the granite runs into the diorite in long tongues striking east and west, that is, 1n coimcidence with the strike of the schists in this area, and here the foliation of the granite is also east and west, and is strongly marked. But where the veins were oblique to the strike of the region, the foliation was oblique and obscure. In another place, where the veins ran north and south, they were intensely contorted. These facts point clearly to the influence of an earth-thrust acting along a north and south line. Foliation in the Diorite. I noticed this on Knockseefin, in veins intrusive in schist. The foliated structure is parallel to the longer axes of the transverse sections of the veins and to the strike of the schists. It is obviously due to pressure. Prof. Bonney has examined slides of this squeezed diorite, and he finds no difference between it and hornblende-schist. Foliation in Veins of an Acidic Rock. Near the summit of Shannarea appear several veins, lenticular in plan, which are not easy to explain. They consist of quartz, with a little mica, probably biotite, and a fair number of garnets. The foliation is very distinct, and coincides with the foliation of the CRYSTALLINE SCHISTS INTO IGNEOUS ROCKS IN CO. GALWAY. 523: enclosing schists. Most of the micais in long, narrow, ragged flakes, almost like bits of frayed string, and suggests great compression. The rock is now a sort of quartz-schist. What it was originally, it is hard to say; but I see no reason why it may not have been a hornblendic granite, like the granite of the district. 4, AcE oF THE Ienxous Rocks. The Silurian conglomerates of Killary Harbour are mainly com- posed of large rounded fragments of igneous and metamorphic rocks. Amongst these is a coarse-grained granite, with a great deal of plagioclase and a little altered biotite. The constituents of this rock are the same as those of the typical Galway granite, but the felspars are smaller. Pebbles of quartz-felsite are also abundant. The ground-mass of this felsite is devitrified, the quartz-crystals are large and clear, and there is a small proportion of biotite. This description will also apply generally to the ordinary quartz-felsite near Galway. The conglomerates clearly prove that in early Silurian times the adjoining land largely consisted of igneous rocks, closely resembling those still found in the region, and we may there- fore fairly conclude that the granite and felsite, with the still older diorite, are of Pre-Silurian age. The metamorphic schists enclos- ing the intrusive masses and veins are, of course, of still greater antiquity. 5. Tue Gatway GneIss. This rock forms a triangular area about two miles each way, with the town of Galway situated in the centre. It is bounded on the west by granite and felsite, on the north-east by the Carboniferous limestone, and on the south by Galway Bay. It is usually coarsely erystalline. The common minerals are quartz, felspar, and horn- blende, with epidote as accessory. The quartz and felspar form the ground-mass. Immersed in it are numerous dark, speckled blocks, suggesting the diorite fragments in the granite further west. These block-like masses are often arranged in a roughly linear manner, but frequently they are irregularly distributed. Hornblende also occurs in bands or masses, displaying a foliated structure. In the latter case, the rock is like true gneiss. Rarely could I find con- tinuous seams of the hornblende. A flaky appearance sometimes occurs on rather a large scale, long slender tongues running out irregularly from patches of foliated hornblende into the grey grani- toid ground-mass. There is no true bedding in the Galway gneiss, so far as I saw; but the seams and masses of hornblendic rock usually lay with their longer axes dipping at a high angle to the N.N.W. Comparing this gneiss with the diglomerates already described, a similarity of origin is at once suggested, the apparent dip being accounted for by tangential pressure. As this was the first district I visited in Con- naught, the significance of the phenomena did not then appear, and my work proceeded on other lines ; but the hints afforded by the 524 CONVERSION OF CRYSTALLINE SCHISTS INTO IGNEOUS ROCKS. behaviour of the igneous rocks of the region further west have since been worked out in the Malvern Hills, as will appear in a separate communication. 6. SuMMARY. 1. There is no satisfactory evidence for the contention that the igneous rocks of Western Connaught have resulted from the meta- morphism of schists, since in every locality examined, including the type section, the igneous rocks were seen to be sharply separable from the schists and clearly intrusive in them. 2. The “‘ metamorphosed conglomerates ” adduced in proof of the original sedimentary character of the Galway schists are mixtures of schist, diorite, and granite, or of two of them, the ground-mass being usually granite. 3. There is no proof that the foliation of the igneous rocks follows an original structure. In the granite it 1s chiefly due to regional pressure. Fragments of diorite in granite are not foliated, but veins of diorite in schist sometimes display a foliation caused by pressure. 4, The ancient gneissic rocks of Galway town display evidence of haying been formed in part from mixtures of diorite and granite, similar to the more modern diglomerates. (For the Discussion on this paper, see p. 514.) iW) oy ON THE CRYSTALLINE SCHISTS OF THE MALVERN HILLS. 5 37. A Pretorary Ineurry into the Gunusis of the CRYSTALLINE Scuists of the Matvern Hints. By Cu. Carraway, Esq., D.Sc., F.G.S. (Read April 6, 1887.) Introduction. 1. The Materials from which the Schists were produced. Diorites, Several Varieties; Granite; Felsite. 2. Evidence of Pressure. Contortion of Granite-veins. 3. The Products of the Metamorphism. A. Simple Schists. Hornblende-gneiss, Mica-gneiss, Mica-schists. B. Injection-Schists. Duplex Diorite-gneiss, Granite-diorite-gneiss. 4, General Remarks. 5. Summary. INTRODUCTION. Tue igneous origin of some foliated rocks was first suggested to me by the granite of Northern Donegal*. The Rev. E. Hill, F.G.S., had previously noticed f a gneissic structure in the granite of Guernsey. Mr. J. J. Harris Teall, F.G.S., has described foliation in basic rocks in the North-western Highlands? and at the Lizard§. Schistosity in granitoid rocks has also been observed in the Alps by Professor Bonney||, F.R.S. Besides English workers, several foreign writers, both American and Continental, have declared in favour of an igneous origin for certain schists, so that the produc- tion of a parallel structure in igneous rocks may fairly be regarded as an established fact. The work which I have described in another paper (p. 517) led me to hope that we might be able to advance a step further. The intru- sion of veins of granite in diorite, under pressure, suggested that at great depths, where pressures were at a maximum and chemical processes might be presumed to be most active, gneissic rocks of a more varied character might be produced. At the town of Galway I had seen gneisses which might have been produced in this way ; but the crystalline schists of the Malvern Hills have furnished clear evidence of the genesis of some of the more complex gneisses, be- sides throwing additional light upon the production of the simpler schists. J am able to show that many of the schistose rocks of Malvern have an igneous origin, and I hope that the clues I have obtained will enable me in a future communication to extend my explanations to certain varieties whose genesis is at present less clearly ascertained. * Quart. Journ. Geol. Soc. vol. xli. p. 221. t Jbid. vol. xl. p. 404. + Lbid. vol. xli. p. 133. § Geol. Mag., Nov. 1886, p. 481. || Quart. Journ, Geol. Soc. Pres, Address, 1886. @.3.G.8. No. 171. 2N 526 DR. C, CALLAWAY ON THE GENESIS OF THE 1. Tor MareriaLs FROM WHICH THE SCHISTS WERE PRODUCED. Diorites. I have been able to recognize at least four varieties of diorite in the schists thus formed. Medium-black (No. 1).—This rock contains about equal pro- portions of hornblende and felspar, and in the mass appears nearly black. The felspar, under the microscope, often presents a cloudy appearance, and contains numerous clear microliths, both conditions indicating alteration. When the alteration is only shght, the twinning of plagioclase is visible, but this occurs only in a minority of the erystals. Coarse-black (No. 2).—The hornblende is often in a greater pro- portion than in No. 1. ‘The crystals of both minerals are larger. The felspars display similar alteration. Coarse-grey (No. 3).—The hornblende is usually about one fourth of the mass. Most of the felspar is less changed, and shows the striping of plagioclase. Medium-grey (No. 4).—The hornblende is abundant, but pale in colour. The felspars display no twinning, are cloudy, with large patches of opacite in the centre, and frequently contain microliths. This variety will be but slightly referred to in the present paper. Tam not prepared to say that none of these varieties ever graduate into each other, but I have seen no evidence of a passage In any case. No. 4 is the newest, for veins of it occur in No. 3; and No. 31s probably newer than Nos. 1 and. 2, since at North Malvern it con- tains rounded and angular fragments of both. The occurrence of these fragments would seem to indicate a consolidation previous to the intrusion of the younger variety, and this is confirmed by sections in the quarries at North Malvern. A mass of No. 2 was seen to be penetrated by a variety of a lighter colour. The vein passed between irregularly shaped joint-blocks, and contained de- tached pieces of the darker kind. Im another mass, a fine- grained diorite was lntrusive in a coarser variety, and in like manner enclosed large blocks of the older rock. In this respect the mode of intrusion is similar to that of the granite in diorite, as described in my paper on the rocks of Galway. I have noticed, however, that in Malvern, as well as the town of Galway, there was a more thorough welding together of the two kinds of rock at their junctions than was observable in the Pre- PIE granite and diorite of Connemara. Granite. I have no positive evidence of the existence of more than one variety of original granite in the Malvern Hills. This is the well- knewn binary compound of quartz and red orthoclase. This granite is younger than all the above-named diorites. By its association with them it gives rise to some of the most interest- ing phenomena of the region. CRYSTALLINE SCHISTS OF THE MALVERN HILLS. 527 Felsite. Near the Wind’s Point, there is a well-marked band of felsite hading in accordance with the banding of the enclosing gneiss. It is compact, homogeneous, and of a pale-reddish colour. A similar rock occurs in the Raggedstone Hill, and by its modifica- tion gives rise to schists. 2. EvipENcE oF PRESSURE. Zones of crushing, indicated by bands of breccia, are very common in the district ; but some of these are posterior to the metamorphism and do not concern us. Some direct evidence of mechanical force, resulting in schistosity, will come out in describing the intimate structure of certain rocks; but it is obviously difficult to obtain very abundant indications amongst igneous masses, where there are no beds to be contorted and faulted. There is reason to believe that the pressure is partly transformed into molecular energy, and thus changes are brought about which often mask mechanical effects. There is, however, some field-evidence for the action of enormous pressures. A good example is seen in a quarry of gneiss at the southern termination of Keys End Hill. The foliation-dip 1s at a moderate angle to the south-east. The rock is traversed by contorted veins of granite, running in several directions. One of these is shown in fig. 1, and gives a rough measure of the pressure. Fig. 1.—Contorted Granite-vein in Geiss. Assuming the vein originally to have been straight, its length has. been reduced in the proportion of about five to two. The regional pressure has acted with intensity only at intervals along the range. In the North Hill and the northern part of the Worcestershire Beacon there are large masses of diorite which have undergone little mechanical change; but between the summit of eBeacon and the Wych there are numerous alternations of diorite and granite displaying foliation. The long ridge between the Wych and the Wind’s Point contains a great deal of black diorite 2Nn 2 028 DR. C. CALLAWAY ON THE GENESIS OF THE with granite-veins; but at intervals, and especially at the southern end, a banded structure has been produced. ‘The northern part of Swinyard’s Hill is composed of massive granite, while at the southern end is a flaggy gneiss, which has been produced from the granite by pressure. Other examples of the localization of pressure occur in the hills further south. 3. Tur Propucts of THE MrtTAMOoRPHISM. A. Simple Schists, or those formed from one kind of rock. Hornblende-gneiss, formed from Diorite-—In this case the pres- sure has rearranged the constituent minerals, so that the horn- blende and felspar lie in irregular folia. There are many grada- tions between the ordinary diorite and a gneiss in which there has been some reconstitution of the minerals, the formation of quartz being the most conspicuous result. The coarse-black diorite, at North Malvern, is one variety which has been modified into gneiss. For about two thirds of the breadth, the intrusion of the vein was clearly seen; then, for a few inches, the two kinds of diorite were confusedly mingled. The remainder of the breadth, consisting only of the coarser diorite, was rudely foliated. Mica-qneiss, formed from Granite.—Near the southern end of Swinyard’s Hill, on the crest of the ridge, is a very interesting case of the formation of gneiss by crushing. A narrow band, striking across the axis, has the appearance of the ordinary binary granite; but a laminated structure 1s very apparent even in the field. In immediate contact, forming part of the same mass, the rock is flaggy, and seams of mica appear. Then comes a break, but flagey schists of the same general type appear in force a few hundred yards to the north. A description of microscopic slides will bring out the transition indicated. No, 281. This was taken as a typical specimen of the granite which is seen in mass at the northern part of the hill. It is the ordinary compound of orthoclase and quartz, with a little mica. Most of the felspar is suffused with a brownish tinge, probably iron- oxide, and presents a cloudy appearance. Many of the crystals also contain patches or microliths of clear mica, polarizing in brilliant colours. The felspar has therefore undergone partial decomposition. That this granite contains iron would appear from the analysis of the Rev. J. H. Timins*. He states that the ‘“‘ quartzo-felspathic” veins, which are almost certainly the granite I am discussing, furnished in three analyses iron-oxide varying between °92 and 1:52 per cent. Both quartz and felspar are some- what cracked, and iron-oxide is deposited in the cracks. Nos. 282-284.—From the locality at the southern end of the hill. | No. 282. From a part of the laminated granite which appears more granitoid than the rest. The rock is excessively cracked and | crushed, the cracks, which run in all directions, but predominantly | * Quart. Journ. Geol, Soc. vol. xxiii. p. 362. CRYSTALLINE SCHISTS OF THE MALVERN HILLS. 529 with the parallel structure, being filled with either iron-oxide or mica. The quartz lies in wedges rather than folia. They are approximately parallel, roughly lenticular in section, and rarely continuous across the slide. Sometimes lines of quartz-grains curve round the felspars. In one part of the field an angular bit of quartz is immersed in a confused mass of quartz and felspar in granules. ‘The parallelism of the quartz seems at some points to be determined by cracks, which are occupied by infiltrated products. The felspar has the brown cloudiness of the uncrushed granite. It is very much cracked, and where crystals are defined they are rather flattened, and often tail out to a point on each side, so as to resemble a human eye inshape. Some of the felspar, forming bands of small crystalline grains between the quartz folia, is very dirty. Mica is very small in quantity. It occurs in some of the narrow eracks in quartz, and in some of the felspar, and rarely it forms a sort of sheath to the attenuated ends of the eye-shaped crystals. No. 283. From the same piece as the last, within a few inches of it, but showing such clear lamination that it caught my eye at a distance. Under the microscope it is much more like a gneiss. The field is clearer, and there is much less cracking of the minerals. The folia of quartz are longer, thinner, and more uniform in thickness. In a few parts the quartz is traversed by longitudinal cracks, but their mode of origin is less evident. Most of the felspar is in regular folia of small crystalline grains, but there still remain a few of the larger felspars with rounded and irregular outlines. Some distinct folia of mica now make their appearance amongst the felspar, but the quantity is still small. There has evidently been much reconstruction of the minerals in this slide. No. 284. Part of the same block, but with the flaggy structure, and showing in the field dark seams of mica. The quartz-folia are still longer than in No. 283 and more regular in thickness. In some spots a thin folium bends out of its course round a crystal of felspar. The felspar is similar to the last. Seams of small granules of this mineral also are seen to curve out of the straight line round large crystals. The notable difference between this and all the preceding slides is in the much greater proportion of mica. It often occurs in regular folia between the quartz. Sometimes it forms a complete sheath to an eye-shaped felspar-crystal. In one place a felspar has been cracked obliquely across, and the crack is filled in with mica. Thus each half of the crystal forms an almond-shaped “eye,” with its fringe of mica. There can be no question that this mica, which is the same in all the set of slides, has been formed out of the felspar. No. 285. From the flaggy schists to the north of the last. The structure of the rock strongly suggests a similar origin. There is more quartz, which here and there looks as if the lines separating its folia had originally been cracks. Several cracks also cut across the foliation, and these are filled in with mineral matter, which in one spot is seen to be optically continuous with a regular folium. At another point an elongated granule of quartz, forming part of 530 DR. C. CALLAWAY ON THE GENESIS OF THE a fohum, passes across a transverse crack which therefore must be older than the folium, and presumably older than the general foliation in its completed state. Where a transverse crack passes through quartz, it sometimes vanishes for a little distance, reappearing further on, so that it is clear that the sides of the crack have come together and become welded. The occurrence of these transverse cracks, and their evident connexion with the process of metamorphism, is a piece of evidence which tends strongly to confirm the suggestions made by the structure of the folia. Mica-schist, formed from Felsite—A very interesting section (fig. 2), about 30 feet in length, is seen in the slope at the end of the Fig. 2.—Passage of Felsite into Schist. 1. Crushed Felsite. 2. Sehistose Felsite. 3. Schists. south-eastern spur of the Raggedstone Hill. Taken in descending order, the following are the rocks observed :— 1. Pale-reddish felsite, so jointed and crushed that it was difficult to obtain a piece large enough for a microscopic slide, and the specimen selected broke into fragments in grinding. This rock forms a band, striking across the ridge in concordance with the foliation of the underlying schists. Under the microscope the rock is seen to be entirely devitrified, and the microcrystalline structure of a typical felsite is very apparent. Even minute fragments, which have remained entire in grinding, are brecciated. The cracks are usually marked by iron-oxide, and, occasionally, when wider than usual, are filled by quartz or by mica. ‘here is a rough parallelism in the structure, and this incipient foliation is some- times accentuated by a little mica. 2. A few feet below the last, and separated from it by soil. The rock is still felsite, much sounder under the hammer than No. 1. Microscopically examined, the field is seen to be clearer, the parallel structure is more distinct, and there is a larger pro- portion of mica. This rock has evidently been porphyritic, for there are several deformed masses of quartz on the slide. One of these is eye-shaped, and tails out at each end in a stream of minute granules. CRYSTALLINE SCHISTS OF THE MALVERN HILLS. od 3. About 15 feet of schistose rock, forming a band below No. 2, but continuous with it. Some of it is hardly distinguishable from the rock above, but the laminated structure is more evident. In other seams the foliated appearance is more marked, and a complete gradation can be traced between the modified felsite and a true schist. The change is seen even on the ground in the increasing distinctness of the lamination proceeding part passu with the growing thickness of the films of mica on the planes of fissility. These indications are entirely confirmed by the microscope. The following gradation is seen in three specimens taken from the same band, within a yard or so from each other. No. 294. Felsitic appearance in hand specimens, but slightly laminated. Under the microscope the parallel structure is seen to be due to intermittent folia of a green mica, in irregular bundles of fibres and sometimes dirty. This part of the rock also must have been a porphyry, for the slide shows several eye-shaped masses of crushed quartz which have caused the folia of mica to curve out of their course, forming, as it were, eyebrows to the quartz, both above and below, just as in the crushed granite described above (p. 529). Some parts of the slide display the felsitic structure, as above ; but where the mica is most abundant the granules of the ground-mass are often of larger size and polarize in bright colours. Mineral differentiation would thus appear to have proceeded a stage further. No. 295. The change in the felsite is more advanced. The rock chiefly consists of elongated granules of quartz arranged in a linear manner, with mica lying between them in microliths, so as some- times to form a partial sheath. Some of this mica is transparent, polarizing in bright colours. Patches of the same mica and some felspar are also present. Distinct seams of mica and felspar, parallel to the longer axes of the quartz-grains, accentuate the foliation. No. 296 is generally similar to the last. In about the middle of the slide is a very quartzose seam, in which the grains are much larger than in the previous specimens. It is not a vein, but a true folium, parallel to the rest. It passes by the gradual introduction of mica into a broad, very micaceous band, which graduates in- sensibly into a zone displaying a structure strongly suggestive of the micro-felsite, but a few microliths of clear mica are present. Some parts of the hand-specimen also have a very felsitic look under the lens. No. 299 is from one of the several narrow micaceous bands inter- laminated with the more quartzose schist. It is an indubitable mica-schist. The mica is the white variety. It forms about half the mass, a great part of it being in distinct folia, which sometimes undulate. Some of the quartz has the same appearance as in Nos. 295, 296,-the granules being more or less sheathed with mica. A few lenticular “‘ eyes” of quartz are rather suggestive of the crushing of a porphyry ; but on this I do not speak decisively. I am quite satisfied, from a very careful study on the ground, that these micaceous seams cannot be regarded as foreign fragments of schist entangled in the crushed felsite. ae, DR. C. CALLAWAY ON THE GENESIS OF THE These modified felsites, now schists, form a low vertical cliff, 30 or 40 yards long, in which the rock is continuously exposed. I worked along the strike to the western end and found similar schists, some of them highly quartzose, passing occasionally into a material like a quartzite, and into felsitic rock like the first named. The different varieties were not always interbanded, but often passed into each other with some irregularity. That they all belong to the same mass I have no doubt. The rapid variations in the metamor- phism agree with the sudden changes noticed in the crushed granite. A specimen of one of the quartzose varieties, almost like a quartzite, was examined microscopically. In structure it is intermediate between a quartzite and a quartz-schist. _ There is very little orien- tation in the quartz, which is frequently in large granules. Mica is. in small proportion. Much of it is in clear microliths, which occasionally form a partial sheath to the quartz-granules, as in the other schists of the locality, but more frequently they have a rough orientation in one direction; occasionally they accumulate into imperfect folia. Parallel with this foliation are several cracks, which are more or less filled in with mica and iron-oxide. Some, if not most, of the mica in the cracks is the same white variety which prevails throughout the slide. This parallel cracking, coincident: with the foliation, is another interesting analogy between this schist and the crushed granite, and is of course suggestive of similarity of causation. B. LInjection-Schists, or those in which the Banded Structure is due to the Parallelism of Intrusive Veins. Two varieties of this rock are here described. Duplex Diorite-qneiss, formed from veins of Diorite mm Drorite.— This fine-banded rock is common in one of the quarries at North Malvern. Parallel seams of grey granitoid diorite (No. 3) are enclosed in a black variety (probably No. 1). The differences between the ordinary diorites and their gneissic representatives cer- tainly do not militate against my theory of the origin of the latter. The following points may be noted :— In the massive black diorite there is some epidote and chlorite and a little green biotite, but in the gneiss there is a much larger pro- portion of biotite, and most of it has a definite orientation parallel to the direction of the adjacent vein. Some hematite also, which is in lath-shaped forms, is similarly orientated. The felspar of the ordinary diorite is cloudy, rarely showing plagioclase-twinning, and contains numerous clear microliths. In the gneiss the felspar of this diorite is rather clearer and sometimes displays striping. Comparing the unfoliated grey diorite with the grey variety in the gneiss, there is no material difference observable. The crystalli- zation of the latter is larger, but in both cases the felspar is pre- dominantly plagioclastic, and the proportions of hornblende, biotite,. epidote, and quartz are about the same. Owing to the want of continuous sections, I was unable to trace CRYSTALLINE SCHISTS OF THE MALVERN HILLS. 533 an actual passage between the massive and the foliated diorites; but if the former were diorites, so were the latter, and I submit that there is nothing in the parallelism of the veining inconsistent with the theory of an igneous origin. But the description of the next variety of gneiss will throw additional light upon this question. Gramte-diorite-gneiss, formed from veins of Granite in Diorite.— This is the most conspicuous gneiss in the Malvern Hills. The gneiss itself and the rocks out of which it is constructed constitute about one half of the entire mass of the range. The diorite is black and of medium grain(No.1). The production of the banded struc- ture is well seen in the long ridge extending between the Wych and the Wind’s Point. At the western quarry on the south side of the Wych there is a mass of the diorite with granite veins. It appears to pass into the gneiss of which the section chiefly consists, but junctions are obscured by débris. Similar rocks, in which there is the like association of massive and foliated mixtures of the diorite and the granite, are seen at intervals along the crest of the ridge to the south. At the top of the third summit the relations of the rocks are well seen. At one spot the granite is intrusive in the ordinary irregular veins, but it passes rather abruptly on the north into a rock in which the veins strike in a definite direction to the north-west, producing the banded structure of a gneiss. This rock is also well exposed about the Wind’s Point. The granite-seams in the gneiss vary considerably in thickness Sometimes they are continuous for yards, but frequently they are lenticular in section. They often behave like veins in their rapid attenuation and in their branching habit. Their parallelism is by no means uriform, as they sometimes pass obliquely across the inter- banded diorite. Comparing microscopic specimens of this gneiss with slides from the unfoliated vein-structures in the Wych quarry, I do not hesitate to say that it would be impossible to determine which was gneiss and which was vein-structure. In both cases there is some epidote and chlorite produced in the diorite at the junction of the granite, and for a little distance from it, while the granite is slightly cracked. This banded gneiss is, then, a binary mixture of ieneous rocks, in which regional pressure has produced a parallelism of the granite- veins. 4, GENERAL REMARKS. As this paper is strictly introductory, the evidence offered is in- complete; but it will perhaps suffice to prove that some of the Malvern schists are produced out of igneous rocks, and to create a presumption in favour of a similar origin for other varicties. In the formation of some of the schists, the chemical and mineral changes have been very great; but into this division of my subject I have barely entered in the present communication. Association of the Gneissic Rocks with the 1 Igneous masses. —It is generally true that particular varieties of gneiss and schist occur in the vicinity of the igneous masses to which they are respectively 5384 DR. C. CALLAWAY ON THE GENESIS OF THE most nearly related in mineral composition. A few examples are here given. In the North Hill we have large masses of several kinds of diorite penetrating each other in veins, and it is in this locality that we find the diorite-gneisses, simple and duplex. North of the Wych the above-named diorites are intermixed with granite, and here we have a variety of gneissic rocks of more com- plex structure. Between the Wych and Swinyard’s Hill there is little besides black diorite and granite, and here we chiefly find the banded granite- diorite-gneiss. Swinyard’s Hill consists largely of granite, and it is in this ridge that the flaggy quartzo-felspathic schists occur. In Midsummer Hill there are masses of coarse diorite, and the gneissic rocks in association with them are certainly more allied in mineral composition with this diorite than with any other igneous rock of the region. Raggedstone Hill contains schists widely differing from any of the above, and here the associated igneous rocks are felsite. These associations cannot be due to accident, and even if no direct proof of actual conversion could be offered, they would be of weight in the argument. Absence of Stratification Except* perhaps in the Raggedstone Hill, I could detect no true bedding in the crystallines of the Malvern Hills. The zones of igneous and foliated rock, though they have a predominantly north-west strike, behave more like veins than strata. Where a sufficiently large surface is exposed in plan, we find the bands, whether massive or schistose, rapidly thin out. For example, on the crest of the ridge about half a mile north of the Wych the attenuation is usually from east to west. Fig. 3 shows a part of one of the exposures in this locality. Age of the Rock.—I see no reason to doubt the received views as to the age of the greater part of these rocks. At the south-western extremity of the Raggedstone Hill, the Hollybush Sandstone rests at a low angle upon the edges of nearly vertical schists. The old rocks of the Salopian district afford confirmatory evidence. The Uriconian conglomerate of Charlton Hill contains several varieties of plutonic rocks, most of which can be matched in the Malverns, and these Uriconians are themselves older than the Longmynd series 7. It is possible that the felsites and the schists formed from them are of a younger epoch. , . Period of Metamorphism.__The most effective pressures may have . acted at more than one period ; but there is no doubt that the meta- morphism was substantially complete before Cambrian times, since it is incredible that a force producing a strike transverse to the ridge could have acted without dislocating the strike of the flanking Cambrian and Silurian strata. * After further research I think it no longer necessary to make even this slight reservation —C. C., July 20th. tT Quart. Journ. Geol. Soe. vol. xlii. p. 481. CRYSTALLINE SCHISTS OF THE MALVERN HILLS. 535 Schistosity, whether produced before or after Consolidation.—The evidence I have submitted points towards the latter alternative. In some of the diorites of the North Hill we have seen that the in- trusive veins passed along planes of jointing and contained fragments of the enclosing rock, as in Galway. ‘Then, too, the schists formed from the granite and the felsite are the effect of crushing. I prefer, however, to postpone the more adequate discussion of this question. Fig. 3.—Plan of Vein-structure i Schistose Rocks. PROS \ ~ WE ip ae ER - Way ~—- v0 ONS 47 - S= y A. Coarse granitoid rock with biotite. B. Bands composed of granite-veins, with seams of dark mica and of coarse rock (A) foliated. C. A yein macroscopically like a fine-grained diorite. Under the microscope it is ‘seen to consist of hornblende, two micas, epidote, and quartz, and has a rude foliation in a specimen taken at the margin. D. Black schist, chiefly mica, penetrated by small granite-veins. 5. SuMMARY. 1. Many of the gneissic and schistose rocks of the Malvern Hills were formed out of igneous masses and veins. Amongst the materials which underwent the metamorphism were several varieties of diorite, a granite, and a felsite. 2. The parallel structure has been caused by regional pressure. This conclusion is proved by the intense contortion of granite-veins, and by the mechanical effects recognized in the rocks under the microscope. 3. The products of the metamorphism are divided into (1) Simple and (2) Injection-schists, the former elaborated out of one kind of rock, the latter out of at least two kinds, one being intrusive in the 536 ON THE CRYSTALLINE SCHISTS OF THE MALVERN HILLS. other. The Simple Schists described are hornblende-gneiss, formed © from diorite, mica-gneiss from granite, and mica-schist from felsite. The Injection-schists noticed were duplex diorite-gneiss, composed of veins of diorite in diorite, and granite-diorite-gneiss, of veins of granite in diorite. In conclusion it was observed that :— (1) Particular varieties of gneiss and schist generally occurred in the vicinity of the igneous masses to which they were most nearly related in mineral composition. (2) No true stratification was detected, the bands of igneous and of foliated rocks thinning out rapidly, in the manner of veins. (3) The received view of the age of the greater part of the rocks was not affected by the conclusions of the Author. (4) The chief metamorphism was completed before the Cambrian epoch. (5) Some, at least, of the schistosity had been caused subsequent to consolidation. (For the Discussion on this paper, see p. 514.) ON FISH-REMAINS FROM THE KEUPER OF WARWICK, ETC. 537 38. On the Rematys of Fisues from the Kevrer of Warwick and Nortinenam. By E.T. Newron, Esq., F.G.S. With Norzs on their Movr of Occurrencr, by the Rev. P. B. Bropiz, M.A., F.G.8., and Epw. Witson, Esq., F.G.S. (Read May 25, 1887.) [Prats XXII.] Ar the meeting of the British Association which took place last September, at Birmingham, the Rev. P. B. Brodie called attention to some specimens of fishes which he had obtained from the Upper Keuper of Shrewley. The specimens, which he has kindly sent to me for examination, are, unfortunately, very fragmentary, but still many of their characters can be deciphered; and seeing that Ganoid fish-remains from these deposits are of such rare occurrence, it is very desirable to place on record any fresh evidence which may be brought to light. Portions of seven specimens have been found, the best preserved (Pl. XXII. fig. 1) showing the left side of the body, minus the head and nearly the whole of the tail, but witi parts of the dorsal, pectoral, ventral, and anal fins preserved in situ, with one or two rays of the tail-fin. In its present condition the specimen measures one inch and a half in length. The second specimen (fig. 2) seems to include the whole of a fish; but it is so curved round, twisted, and crushed, that its form is well-nigh obliterated. When perfect, it probably measured two inches and a half in length. The large fulcra of the tail-fin are well seen from above; but with the exception of one or two plates, probably belonging to the head, little of the structure can be made out. The third specimen (fig. 3) appears to be a head with the right pectoral fin and a portion of the body; but none of the bones of the head are preserved, and there is merely an outline in the form of a head in front of the pectoral arch. Two other fins are pre- served on this block of stone, but they seem to be parts of another fish. The fourth specimen is a portion of a body with the ventral fin (fig. 4) preserved. The fifth and sixth specimens (figs. 5, 6) are portions of tails. The seventh specimen, now in the British Museum, is a body with perhaps a fragment of the head, but without any tail or fins. The scales, in the middle of the side, have their hinder margins denticu- lated (fig. 7). So far as preserved, these specimens are much alike, and there is nothing to lead to the supposition that they belong to more than one species. Judging from the best specimen (fig. 1) the body is comparatively deep, its entire length, when perfect, being only about two and a half times the depth. At the front part of this specimen there is a curved fragment, which seems to be part of the pectoral arch, and a little behind this there are traces of the pectoral fin. The form of this fin, however, is better shown in another specimen (fig. 3). If the lower margin of this specimen (fig. 1) be divided into three equal parts, then at the junction of 538 MR. E. T. NEWTON ON FISH-REMAINS FROM THE the first and second thirds will be the attachment of the’ ventral fin ; and at the point between the middle and hinder thirds the beginning of the analfin. The form of the ventral fin is best shown by speci- men number four (Pl. XXII. fig. 4). The pectoral, ventral, and anal fins are of moderate size ; but the single dorsal fin is large, with strong and seemingly articulated rays, while its anterior border is provided with well-developed fulcral scales. This fin begins nearly opposite the ventral fin, and seems to have extended backwards almost to the anal fin; but the hinder part being broken away, its exact extent cannot now be seen. Several ridges and grooves extending downwards from the dorsal fin indicate the presence of strong interspinous bones. The tail-fin is not preserved in number one (fig. 1); but the fragments of tails (figs. 5, 6) show that the upper lobe was larger and stronger than the lower, and had its upper margin furnished with particnlarly large fulcra (see also fig. 2), and its sides covered with elongated spindle-shaped scales. The sides of the body are covered with comparatively strong, shining, rhomboidal scales, which in the middle region are large and from two to three times as long from above downwards as they are from back to front. Towards the tail, as well as above and below, the scales become smaller and nearly equal-sided. The surface of the scales is smooth and shining; but on some of them, especially towards the tail, two or three indistinct oblique ridges run from front to back. In the first specimen (fig. 1) the hinder border of the scales is imperfect, and it is not clear whether this was smooth or denticulate; but specimen number seven has some at least of the body-scales finely denticulate (fig. 7). One of the tails (fig. 6) also shows that in some. of the scales the indistinct ridges end in points on the hinder margin. Unfortunately none of the specimens give any clear information as to the form of the head, or of any of its bones or plates. The restored outline of figure 1 is hypothetical, and is merely added to give a better idea of the position of the parts preserved. In the position where the bones of the head might be expected (figs. 2 and 3) there are only indistinct traces, which may be bones partially dissolved, and these appear granular on account of the sandy matrix beneath. Specimen number 2 shows what seems to be a comparatively large conical tooth near the end of the snout (fig. 2,a). In the opercular region there is a broad plate (6) with two tooth-like prominences at its hinder border, which may be one of the opercular bones; and a strongly striated plate (c) seen a little further back will probably bear a like interpretation. . The seventh specimen also shows a similar striated plate. The only ganoid fishes which have been described from British Triassic strata are the unique specimen of Dipteronotus cyphus, from the Bunter of Bromsgrove, described by the late Sir Philip Egerton *, and the Paleoniscus superstes, also described by the same author fT, from a specimen found by Mr. Brodie at Rowington, in > * Quart. Journ. Geol. Soc. vol. x. p. 367 (1854). T Ibid. vol. xiv. p. 164 (1857). KEUPER OF WARWICK AND NOTTINGHAM. 539" beds of the same Upper Keuper age as those which have now yielded the specimens above described. ‘To neither of these Triassic fishes can the Shrewley specimens be referred. In the form and position of the fins the Shrewley specimens agree with Semionotus ; but with such imperfect material, more especially the absence of information as to the nature of the head, the generic affinities of this fish must be uncertain, and I am unable to find any described species with which it will agree. Amongst the forms described by Agassiz, Semionotus striatus, from the Lias of Seefeld *, is perhaps the nearest to our fossil; but besides being much larger, this has all the scales of a more uniform size. In this latter particular S. Mils- soni is more like, but in other respects it is even further removed from, our specimens. Sir Philip Egerton described three species of Semionotus from beds, said to be of Liassic age, at Castella- maret; but the descriptions of these are sufficient to show that they are not the same as the Shrewley Triassic fishes. If it should be thought desirable to have a name for such rare British fossils, it is suggested that the species be called after its discoverer, Semionotus Brodie. Mr. KE. Wilson, at the British Association Meeting at York §, called attention to the discovery of fossil fishes in Keuper beds at Nottingham. In the abstract of this paper it is said that “‘ The specimens he obtained have been examined by several competent authorities; but, unfortunately, their state of preservation is so bad that nothing certain can be made out as to their precise zoological affinities. Dr. Traquair, however, believes that they probably belong to some species, new or old, of the genus Semionotus.” No further account seems to have been published ; but Mr. Wilson has been good enough to let me see these specimens. A few of his best examples were presented to the Nottingham University College Museum; and through the courtesy of the museum authorities and of the Curator, Mr. J. W. Carr, I have had the opportunity of examining these also. The number of fishes in this deposit must have been very great, as will be gathered from the notes by Mr. Wilson (p. 542). Many of these have the scales well preserved ; but unfortunately none give any satisfactory clue to the form of the body. One of the most perfect is on a small slab belenging to the Nottingham Museum, and is marked No. 1. In size, as in other respects, this agrees fairly well with the Shrewley fishes; it is lying partly on its back, so as to show both the ventral fins and above them the dorsal fin; the tail is twisted round, so that its upper border is now turned downwards. ‘The position of the head is indicated by some irregular bony plates; butits form is uncertain, The moderately heterocercal tail and the position of the dorsal and ventral fins agree with Semionotus, and possibly the fish may belong to the same species as those discovered by the Rey. P. B. Brodie. The dorsal fin-rays which are preserved are entire and not articu- lated, as in the Shrewley specimen; it may be, however, that these * ¢ Poissons Fossiles,’ vol. ii. p. 231. if Loe! cits p. 229: + Proc. Geol. Soc. vol. iv. p. 183 (1848). § Rep. 1881, p. 637. 540 REV. P. B. BRODIE ON AN UPPER are anterior rays, while those preserved in the Shrewley fish are not the front ones. Another specimen, also belonging to the Nottingham Museum, and, apparently, part of a similar fish, has these entire dorsal fin-rays very well shown (Pl. XXII. fig. 8). On the same slab with No. 1 specimen there are fragments of what appears to be a Paleeoniscoid fish. This is a portion of an extremely heterocercal tail (marked No. 2), the upper lobe being covered by numerous slender elongated scales. Some of the more anterior and ventral scales of this fragment have longitudinal stria- tions; and other fragments on the same slab, with strongly striated scales (marked 3 and 4), probably belong to the same fish. The markings on these scales are not easy to decipher, but there seem to be five or six oblique ridges traversing the exposed part of the scale. Figure 9 fairly represents one of these scales, which are much like those of Elonichthys given by Dr. Traquair *. On another slab there are fragments of a larger fish, as indicated by some masses of scales; but these are too fragmentary to call for more than a passing notice. Notes on the Upper Keuper Section at Shrewley where the Fish were found, and on the Trias generally in Warwickshire. By the Rev. P. B. Bropre, M.A., F.G.S. As a rule, the Trias in Great Britain, considering its extent and thickness, is noted for the paucity and rarity of fossils, perhaps it is the most unfossiliferous of all rocks containing organic remains in this country, especially when compared with the abundant fauna and flora of the New Red Sandstone in Europe and other parts of the world. Any addition therefore to our knowledge in a field so comparatively barren is of considerable interest to the Paleontolo- gist. It is now many years ago since I discovered Palwoniscus superstes, apparently the last of the genus, in the Upper Keuper at Rowington. Last summer, in company with my son, Mr. Douglas Brodie, I visited the sandstone-quarry at Shrewley, and he drew my attention to some obscure remains on a slab of sandstone which, when cleared, turned out to be portions of fish, unfortunately fragmentary and ill preserved, belonging to the genus Semionotus fT, which, though frequent in the German Keuper at Coburg, Stuttgardt, and elsewhere, has not been previously recognized here. On a second visit I found a few more in a somewhat better condition, all of which I placed in Mr. Newton’s hands. On the slab on which * Pal. Soc. 1877, pl. v. + Another and larger fish was found at Shrewley some years ago, but the owner will not part with it nor allow it to be figured or described. I showed a photograph I have of it to Sir P. Egerton, at the meeting of the British Association at Exeter in 1869, and he thought it might be a species of Semionotus. It measures from head to tail about 5 inches in length and half an inch broad in the centre of the body; it stands out in relief, lying on its back on a block of sandstone, and resembles in its mode of preservation some of the fine fish from the Ilminster Lias, discovered by my friend the late C. Moore. In the New Red Sandstone of North America several fossil fish have been met with and will shortly be figured and described by Dr. Newberry, of the School of KEUPER SECTION AT SHREWLEY. 541 the first specimens were found were two impressions of footsteps of a large Labyrinthodon, and I fancy that the whole number, seven, may have been lying on the surface of one large slab afterwards broken on removal. The following section of the quarry will show the probable position of most of the fossils which occur there :— ft. An 1. Soft, brown-coloured sandstone, current-marked ................ceeeee0: Od PG EeCHaMmiratls, LIMORe/OF LSs SANG Y.. 5.1: «-js/c4s-aoeee sees ded ecdseienccss oa mawoar 4 7 3. Friable sandstones, in beds divided by green marl, softer at the top, getting harder at the bottom, with green marly surface............... a. 2 4, Seven or eight beds of sandstone of variable hardness, with Hstheria, divided by marls, the bottom rock the hardest ..............-.e+cecees 5 0 De tard tea-sreen marls with Hstheria .......ccesces-cacosecuerceetoewneseos Tia Mota ee. csiexste «aes 2a 8 This section faces the south; at the east end of the quarry there are about 20 feet of red marls, above the green marls and thin-bedded brown sandstone, Nos. 1 & 2. The strata are nearly horizontal. The ‘bottom rock’ is exposed on the canal at Rowington, where it has a slight dip, owing te a local disturbance, and it appears again on the road between that village and Shrewley, and elsewhere. The lowest bed in No. 3, probably containing the fish, is a rather soft, gritty sandstone, made up of small grains of white quartz and other variously coloured rolled material, very small, loosely connected together, and readily broken. Here and there this sandstone is traversed by bands of green marl. The most abundant organisms in this bed, which have been known for a long time, are the remains of Cestracionts, consisting of teeth, palatal and cutting {the latter very rare), of several species of sharks, with the dorsal spines and, occasionally, portions of the shagreen. I have in my collection a series of small palates, united together, which is a unique example from the Trias here. A similar stratum, with similar fossils, occurs at several localities in Worcestershire. Footprints of Labyrinthodon, generally of small size, are occasionally found on the surface of the sandstones; and at Rowington remains of plants in a very imperfect condition, among which is Volézia in fructification, and some small fruits resembling the Jurassic Carpoli- thus, so called. The ‘bottom rock’ is an excellent and durable building-stone, and was formerly largely quarried at Rowington and other places. In most works on geology the New Red Sand- stone is simply classed as a series of stratia of variously coloured Mines, New York. He informs me that he has enumerated about twenty Species from the American Trias, viz. :— Caropicnus Rediield acs .ch)sesenocir essences 6 species. Ischypterus, Egerton= Pal@oniscus............ I2Zi- 5; BZCUCHO) Cpts We NOASS «rit ige «Balas sere sina winstices be hs 5s WB UEU SSN WDOIIGY fe sete sco isis as <0. = s.r: ileeerie Dr. Newberry states that the American genus Ischypterus is so near to the genus Semionotus, that if found in Europe, Agassiz would have referred it unquestionably to that genus. @rJ.G. 8: No. 171. 20 542 MR. E. WILSON ON TRIASSIC BEDS AT marls and sandstones, including the waterstones at the base. Now there are in Worcestershire several marls and sandstones, including the Waterstones, having at the bottom the hard rock above men- tioned, overlying green marls with Hstheria, succeeded by a thick stratum of red marls, which evidently come between these and the lower Waterstones at Warwick, Leamington, Cubbington, and else- where, so that the New Red in this district might be fairly divided into Upper and Lower Keuper, with two important beds of sandstone, one above and another below, separated by red marls, which would form hereabouts the dividing line. The same thing applies to the neighbourhood of Rugby, and is, I see, adopted by the local geologists there. The same subdivision is also adopted by the Rev. J. Mello for the Cheshire Trias; and I think it might be generally and advantageously adopted where these two sandstones, which differ lithologically, are closely separated by a thick inter- vening mass of red marl. The Waterstones are famous for the number (comprising nine genera) of Salamandroid Batrachians, a large number and variety of which have been found at Warwick, Leamington, and Coventry; and a unique collection is preserved in the Warwick Museum. I may add that although the red rocks of Kenilworth and Coventry have hitherto been assigned to the Permian, there seems every probability that a large peipanion of the former will now have to be classed with the Trias. Notes on the Triassic Beds at Colwick Wood, near Nottingham. By Epw. Witson, Esq., F.G.S. The small fishes described were found by me in the summer of the year 1879, in the roof of a tunnel which was being driven through the side of the hill at Colwick Wood, near Nottingham, for the Leen Valley Outfall Sewer. They come from the Lower Sandstone or ‘Waterstones’ of the Upper Keuper, which at this point rest upon the ‘Basement-beds’ of the Lower Keuper. The fishes were apparently limited to the lowest stratum of the ‘ Waterstones,’ a bed of greenish-yellow sandstone 10 inches thick, with intercalated streaks of red and green marl, and a seam of pebbles at its base, and to the bottom inch or two of that stratum. This bed may be seen cropping out in an adjoining field on the hillside which here forms the escarpment of the Trent Valley, but it is not fossiliferous at that point; and although there have been many opportunities of examining the strata at the same horizon on the east side of Not- tingham, and at other places in the vicinity, no traces of any similar organisms have, so far, been discovered elsewhere in the district. In addition to the exceptional interest that is always to be derived from the presence of organic remains in Triassic rocks, as a rule so barren of life, there were two points specially noticeable in con- nexion with the occurrence of these fossils in the Keuper at Nottingham; namely, first, the great number of the fishes, there being quite a shoal of them for a distance of thirty feet or there- about, in the line of section, the individual fishes even lying over ee ee SE ee hog! eee Quart.dourn. Geol. Soe Vol. XLII. Pl XXII. Se: e0 F 2 ha A G P| a8 ics 7S a8 a8 Dies py O8 2 2 45 gat © FASS ~ g § 3 & fsa} es Se COLWICK WOOD, NEAR NOTTINGHAM. 543 one another in the middle portion of that distance, but gradually becoming more widely separated in either direction until they finally came to an end; and, secondly, their occurrence at the junction of two subformations of the Trias, namely, of the Water- stones of the Upper Keuper and the Basement-beds (Lower Keuper). This may be, and probably is, merely an accidental coincidence. At the same time, it may be worth while to record the fact. The two series of deposits, at the junction of which this fossil shoal of fishes was found, are of very diverse characters, and were formed under very different physical conditions. The Keuper Basement- beds are a series of gritty, false-bedded sandstones with frac- tured quartzite pebbles and strange wedge-shaped intercalations of fine red marl and marly débris, irregularly bedded and showing clear signs of the existence of powerful currents as well as of considerable contemporaneous erosion. These deposits I believe to have probably had a fluviatile origin. The Waterstones, on the other hand (at the base of which the fishes occurred, and to which series they belong), are regularly bedded fine-grained sandstones and marls, showing ripple-marks and sun-cracks*, and were evidently formed in waters which were tranquil but extremely shallow, and liable to entire and perhaps rapid desiccation. These waters were in all probability those of saline lakes or lagoons. Possibly the fishes found at Colwick may have become entrapped in the shallows of such a lake, and killed in numbers by the drying-up or the increasing salinity of the water. EXPLANATION OF PLATE XXII. Fig. 1. Semionotus, found by the Rev. P. B. Brodie in the Upper Keuper of Shrewley, twice natural size. d, dorsal fin; p, pectoral fin; v, ventral fin; an, anal fin. The head and greater part of the tail are wanting, but their probable form is indicated by a hypothetical outline. Fig. 2. A much crushed specimen, natural size, showing the large fulcral scales of the tail. Fig. 3. Another example, twice natural size, showing part of head, pectoral fin, and possibly part of ventral fin. Fig. 4. A fragment, showing ventral fin, twice natural size. Fig. 5. A tail, twice natural size, showing its moderately heterocercal cha- racter. Fig. 6. A similar specimen, also twice the natural size, showing the large fuleral scales. Fig.6a. A few of the scales, further enlarged. Fig. 7. Scales, enlarged, from a specimen presented to the British Museum by the Rey. P. B. Brodie, showing their denticulate margins. Fig. 8. One of the numerous specimens of Semonotus found by Mr. EH. Wilson in the Trias of Colwick Wood, near Nottingham; natural size. Other examples show that the ventral fins (and probably the anal fin) were situated as in figure | above. Fig. 9. A scale, enlarged 20 diameters, of one of the Palzoniscoid fishes, also found by Mr. B. Wilson in the Trias of Colwick Wood. * In these lowest beds of the Waterstones at Colwick I found the stem of a land plant having the appearance of Hguisetites columnaris, and probably allied thereto. Unfortunately it was only a sandstone cast, and too friable to remove. rors 544 MESSRS. JUKES-BROWNE AND W. HILL ON THE LOWER PART 39. On the LowER Part of the UpPper Cretacrous SERIES 7m Wrst SurFotk and Norrotk. By A. J. Juxes-Browne, Esq., B.A., F.G.S., and W. Hirt, Esq., F.G.S. (Read June 8, 1887.) INTRODUCTION. Tur zonal subdivisions of the Cambridgeshire Chalk were first described in 1880 *, and more fully in the Memoirs of the Geological Survey, in 1881, the outcrops of the Totternhoe Stone and the Melbourn Rock having then been traced as far as Burwell and Newmarket respectively ; but the survey of the Suffolk Chalk having been previously completed, the lines were not continued on the Survey map. The section exposed in the cliffs near Hunstanton has often been described, but the beds there seen are very different from those which occupy a similar stratigraphical position near Newmarket; it was evident, therefore, that between these two places the beds forming the lower part of the Chalk underwent a considerable amount of lateral change, and that, until more was known of the manner in which one facies of the Lower Chalk passed into the other, no correlation of the Norfolk and Cambridge sections could be more than suggestive. Moreover, in the absence of this information, one of us has found much difficulty in correlating the subdivisions of the Lincolnshire Chalk with that of the Midland counties, and he felt that when once the constitution of the Norfolk Chalk was properly understood, that of Lincolnshire, which bears great resemblance to it, would no longer offer any difficulty. It being clear, therefore, that important issues depended upon an investigation of the changes that take place in the Cretaceous rocks as they pass from Suffolk into Norfolk, it was with the object of exploring this terra incognita that we started from Newmarket in June 1886, and worked rapidly northward as far as Shouldham and Marham in Norfolk. By this traverse we succeeded in obtain- ing some important information, which was communicated to the Director of the Geological Survey, the result being that Mr. Whitaker was sent into the district, and one of us accompanied him in continuing the work through Norfolk to Hunstanton. During this traverse the lines for the Melbourn Rock and Totternhoe Stone were drawn, and that for the Melbourn rock will be engraved on sheets 65 and 69 of the Geological Survey map. A third visit was made in September, and two others in the spring of this year, for the purpose of gaining further information on certain points, and superintending the execution of three borings which were made for the purpose of testing the accuracy of our conclusions at localities where little natural evidence was obtainable. * Geol. Mag. dec. ii. vol. vii. p. 248. t ‘Geology of the Neighbourhood of Cambridge,’ by W. H. Penning and A. J. Jukes-Browne, pp. 20 ez seq. OF THE UPPER CRETACEOUS IN WEST SUFFOLK AND NORFOLK. 545 The present communication therefore is based upon our joint investigations in the field, checked and confirmed by the results of the borings, by the examination of the fossils collected from the various exposures, and by the study of more than 150 rock-slices under the microscope. The mass of evidence thus obtained will naturally be treated under the three heads of (1) stratigraphical evidence, (2) paleontological evidence, (3) microscopical evidence; and these are supplemented by the chemical analyses which the kindness of Dr. Johnstone enable us to adduce. We desire also to thank Mr. Whitaker for his assis- tance and cooperation in the field, and for his readiness to impart such information as he possessed. § 1. SrrarrerapHicaL EvipEnce. For the purposes of description, it will be most convenient to divide our matter into three portions under the following heads: (a) the Gault and the Cambridge Greensand, (6) the Totternhoe Stone and Chalk-marl, (¢) the Grey Chalk, Melbourn Rock and associated beds, tracing each division from south to north, and de- scribing the exposures which we observed along the tract occupied by it. A. The Gault and Cambridge Greensand. On the eastern borders of Cambridgeshire, near Reach, Burwell, and Soham, well-sections prove the thickness of the Gault to be about 100 feet, the information obtained showing a variation between 90 and 110 feet at different places. The greater part of the Gault lies below the surface of the Fen, so that little can be seen of it; but some fourteen or fifteen years ago many Coprolite-pits were open between Reach and Soham, and we quote the following observations from the ‘Survey Memoir on the Neighbourhood of Cambridge’ (p. 34) as indicating that the clay which here underlies the Coprolite-bed belongs to a different and probably higher part of the Gault than that on which it rests near Cambridge. The memoir says:—‘The phosphate nodules extracted from these pits exhibited different characters from those obtained nearer Cambridge ; there was a much greater proportion of hghter-coloured phosphates, and the fossils which occurred among these had not apparently been subjected to much rolling, but retained their shells in a more perfect state than usual—Terebratule, Rhyn- chonelle, and Haogyre being especially common and well pre- served. . . . Amongst the darker nodules there are some which have a greenish exterior, and the whole assemblage has a different aspect from those [of the pits] to the south, as if resulting from the erosion of differently constituted beds in the Gault.” It is also mentioned that at one pit near Reach “a second Coprolite-bed was worked in the mass of the Gault, about 8 feet below that forming the base of the Chalk-marl,’” the fossils from both beds being mixed in the washed heap. 546 MESSRS. JUKES-BROWNE AND W. HILL ON THE LOWER PART Fig. 1.—Map of the Outerop of Cretaceous Rocks in West Suffolk and Norfolk. (Scale 8 miles to 1 inch.) = SS == (