' vel yet ' ; yon : : ey is , ‘ ‘pty \. 4 s . . , Tinh Wawa hem, stot hte read od * pe Noyes cs Se . . y ‘ : . . . Veil w t . on r, Ly ks : : ; a : i ee 3 : : - apogee eam : ‘ UN SRare eS ; aola ae NY inten fr dniried Ropnge : ‘ yigerd i : ae) i Sc Ee o ‘ TOCA in : ee ‘2 rs ‘ 2 AS Pe my ” - oy nas f a ' eae ELLY ; us fies Re ake i ' j FOR THE PEOPEE FOR EDVCATION FOR SCIENCE LIBRARY OF THE AMERICAN MUSEUM OF NATURAL HISTORY af OMA, Monoarad! ha Ae PALAONTOGRAPHICAL SOCIETY. VOLUME Xx. CONTAINING SUPPLEMENT TO THE FOSSIL CORALS. Part IV.—No.1 (Liassic). By Dr. Duncan. Eleven Plates. THE TRILOBITES OF THE SILURIAN, DEVONIAN, &c., FORMATIONS. Part IV (Sitvrtay), By Mr. J. W. Satrer. Six Plates. THE FOSSIL BRACHIOPODA. Part VII.—No. 2 (Stturntan). By Mr. Davinson. Ten Plates. THE BELEMNITIDA. Part III (Liasstc Betemnites). By Professor Puixures. Thirteen Plates. ISSUED FOR 1866. JUNE, 1867. He. vwigp meet, 14, THE PALA ONTOGRAPHICAL SOCIETY was established in the year 1847, for the purpose of figuring and describing the whole of the British Fossils. Each person subscribing ONE GUINEA ts considered a Member of the Society, and ts entitled to the volume issued for the year to which the subscription relates. Subscriptions are considered to be due on the First of January in each year. The back volumes are in stock, and can be obtained (one or more) on application to the Treasurer or the Honorary Secretary. The volumes are delivered free of carriage to any address within three miles of the General Post-Office, and are booked free of expense to any place beyond the three-mile radius ; but in that case the carriage must be paid by the Member to whom they are sent. Gentlemen desirous of forwarding the objects of the Society can be provided with circulars for distribution on application to the Honorary Secretary, the Rey. Tomas Wintsuire, Rectory, Bread Street Hill, London, E.C. The Volume for 1867 is in preparation, and will be issued before the close of the present year; that for 1868 in the spring or summer of that year. Eehis. f OF Che Council, Secretaries, and Members OF THE PALHONTOGRAPHICAL SOCIETY ; AND A CATALOGUE OF THE WORKS ALREADY PUBLISHED; A CLASSIFIED LIST OF THE MONOGRAPHS COMPLETED AND IN PREPARATION, WITH THE NAMES OF THEIR RESPECTIVE AUTHORS; THE DATES OF ISSUE OF THE ANNUAL VOLUMES; AND A GENERAL SUMMARY SHOWING THE NUMBER OF THEIR PAGES, PLATES, AND FIGURES, AND OF THE SPECIES ILLUSTRATED AND DESCRIBED. Council, Elected 26th March, 1867. President. W. J. HAMILTON, Esgq., F.R.S., G.S. Vite-Presidents. J.S. Bowrrsank, LL.D., F.R.S., G.S. T. Davipson, F.R.S., G.S. | Sir R. I. Murcutson, Bart., F.R.S., G.S. Pror. Owen, M.D., F.R.S., G.S. Council, Pror. AnstepD, M.A., F.R.S., G.S. H. Les, Esa., F.L.S., G.S. J. J. Braspy, M.D., F.G.S. W. H. Leteuton, Esa., F.G.S. P. M. Duncan, M.B., F.G.S. Sir C. Lyewt, Bart., M.A., F.R.S., G.S. R. 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FAULKNER, Esq.,_ F.S.A., HLotul Secretaries. } | Glasgow—W atter Crvum,Esq.,F.R.S., Thornliebank. Guildford—R. A. C. Gopwin-AustEN, Esq., F.R.S., F.G.S., Chilworth. Kendal— Tuomas Goveu, Esq. Leeds—Tuios. NuNNELEY, Esa. Leicester—Jamus PLant, Esa. Liverpool—G. H. Morton, Esq., F.G.S. Norfolk—Rrv. J. Guny, M.A., F.G.S., Instead, Norwich. ‘ Oxford—Pror. J. Puruies, F.R.S., G.S. Paris—M. F. Savy, 24, Rue Hautefeuille. Plymouth—J. H. Fue, Esa. Richmond, Yorkshire—Epwarpv Woon, Esq, F.G.S. Scarborough—Joun Leckensy, Esgq., F.G.S. Stamford—Joun F. Bentiey, Esa. Tonbridge Wells—J. Suanp, Esq., F.G.S. Torquay—Wn. PrencELLy, Esa., F.R.S., G.S. | Wolverhampton—Hy. Brecxert, Esq., F.G.S. LIST OF MEMBERS.* APRIL, 1867. Her Most Gracious Masesty THE QUEEN. Adlard, J. E., Esg., Bartholomew Close, E.C. Allport, S., Esq., Snow Hill, Birmingham. Angelin, Professor, Stockholm, Ansted, Professor D. T., M.A., F.R.S., G.S., &c., Atheneum Club; and 33, Brunswick Square. Arbuthnot, Capt. 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H., Liphook, Hants. Cobbold, Rev. R. H., Rectory, Broseley, Salop. Cocchi, Sig. Q., Professor of Geology, Florence. Colchester, W., Esq., F.G.S., Grundesburgh Hall, Ipswich. Collings, Rev. W. T., M.A., F.L.S., G.S., Lord of Sark, Channel Islands. Collingwood, F. S. W., Esq., Glanton Pyke, Glanton, Northumberland. Colvin, Col. John, C.B., Leimtwardine, near Ludlow. Compton, Rev. John, Minesteed Parsonage, Lyndhurst. Cooke, Lieut.-Col. A. C., R.E., 95, Mount Street, W. Cooper, Charles J., Esq., Bridgnorth, Salop. Cornthwaite, Rev. T. M., M.A., Walthamstow. Corrie, A. J., Esq., Glenalton, Torquay. Cotteau, Mons., Paris. Cotton, R. P., M.D., F.G.S., 46, Clarges Street, Piccadilly, W. Crickitt, E., Esq., 12, Catherine Place, Bath. Cross, Rev. J. E., Appleby Vicarage, Rugg, Lincolnshire. Cross, R. A., Esq., Hill Cliff, Warrington. Crowley, Alfred, Esq., Bramley Oaks, Croydon, S. Crum, Walter, Esq., F.R.S., Local Secretary, Thornliebank, Glasgow. 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Durham, the Dean and Chapter of, Durham (by Samuel Rowlandson, Esq., the College, Durham). Kassie, W., Esq., F.G.S., 11, Park Road, Regent’s Park, N.W. Eccles, James, Esq., Springwell House, Blackburn. Edgell, Rev. E. Wyatt, 2, Lansdowne Terrace, Ladbroke Square, Notting Hill, W. Edinburgh Geological Society, Edinburgh. Edinburgh Museum of Science and Art, Argyle Square, Edinburgh. Edwards, F. E., Esq., F.G.S., 22, Woburn Square, W.C. Egerton, Sir Philip de Malpas Grey, Bart., M.P., Trustee Brit. Museum, F.R.S., G.S., &c., Oulton Park, Cheshire; and 288, Albemarle Street, W. Elliott, John, Esq., Kingsbridge, Devon. Elhot, Walter, Esq., Wolfelee, Hawick, N.B. Enniskillen, William Willoughby, Earl of, D.C.L., F.R.S., G.S., &c., Florence Court, Enniskillen ; and Athenzeum Club, 8.W. Eskrigge, R. A., Esq., 3, Batavia Buildings, Liverpool. Etheridge, R., Esq., F.G.S., &., Museum of Practical Geology, Jermyn Street, S.W. Evans, John, Esq., F.R.S., G.S., Nash Mills, Hemel Hempstead. Evans, Thomas, M.D., Gloucester. Everest, Rev. R., F.G.S., 50, Cleveland Square, W. Eyton, Thomas C., Esq., F.L.S., G.S., &c., Eyton, near Wellington, Salop. Falconer, Thomas, Esq., F.G.S., Usk, Monmouthshire. Falkner, Frederick, Esq., Somersetshire Bank, Bath. Farnham, Lord, Carlton Club, 94, Pall Mall, S.W. Faulkner, Charles, Esq., F.S.A., G.S., R.G.S., Local Secretary, Museum, Deddington, Oxon. Favre, Mons. Alph., Professor of Geology, Academy, Geneva. Ferguson, William, Esq., F.L.S., G.S., R.G.S., &c., Kinmundy, Mintlaw, Aberdeenshire ; and 2, St. Aidan’s Terrace, Birkenhead. Fielding, Edward, Esq., 142, St. Paul’s Road, Camden Square, N.W. Fisher, Rev. Osmond, M.A., F.G.8., Elmstead Vicarage, Colchester. Fletcher, T. W., Esq., M.A., F.R.S., G.S., S.A., Lawneswood House, Stourbridge. Flower, J. W., Esq., F.G.S., Park Hill, Croydon, S. Forbes, John Edward, F.G.S., 3, Faulkner Street, Manchester. Fort, Richard, Esq., 24, Queen’s Gate Gardens, Kensington, W. Fox, Rev. W. Darwin, Delamere Rectory, near Chester. Fraser, John, M.D., Wolverhampton. Friedlander, Messrs., Local Secretaries, Berlin. Froggat, John, Esq., Church Gate, Stockport. Fryer, A., Esq., Chatteris, Cambridgeshire. Fuge, J. H., Esq., F.R.C.S.E., Local Secretary, Plymouth. Galton, Captain Douglas, R.E., F.R.S., G.S., &c., 12, Chester Street, Grosvenor Place, S.W. Gassiot, I. P., Esq., F.R.S., &c., Clapham, S. Gatty, Charles, Esq., F.G.S., Felbridge Park, East Grinstead. Geological and Polytechnic Society of the West Riding of Yorkshire, Leeds. Geological Society of Manchester. Geological Survey of Great Britain, Paleontological Department, Jermyn Street, S.W. Geologists’ Association, King’s College, W.C. Gibson, G. S., Esq., Saffron Walden. Gibson, Thomas F., Esq., F.G.S., &c., 124, Westbourne Terrace, Hyde Park, W. Gilbertson, Henry, Esq., Hertford. Gilchrist, J., M.D., Crichton Royal Institution, Dumfries. Glasgow Geological Society, Andersonian University, Glasgow. Gloucester Literary Society, Gloucester (by Dr. B. Wagbourn). Godlee, Burwood, Esq., Leighside, Lewes. Godlee, Rickman, Esq., Lillies, Upton, Essex. Godwin-Austen, R. A. C., Esq., F.R.S., G.S., &c., Local Secretary, Chilworth Manor, Guildford, Surrey. Gordon, P. L., Esq., Craigmyle. Gongh, Capt. the Hon. George S., F.G.S., L.S., &c., Lough Cutra Castle, Gort, Galway, Treland. Gough, Thomas, Esq., Local Secretary, Kendall. Gould, John, Esq., F.R.S., L.S., Z.S., &c., 26, Charlotte Street, Bedford Square, W.C. Gratton, Joseph, Esq., 32, Gower Street, W.C. Gray, John, Esq., Lyttleton Terrace, Hagley, near Stourbridge. Gregory, J. R., Esq., 15, Russell Street, Covent Garden, W.C. Griffith, Sir Richard, Bart., LL.D., F.R.S.E., G.S., &c., 2, Fitzwilliam Place, Dublin. Grundy, Thomas, Esq., Beatlands, Sidmouth, Devon. Guise, Sir W. V., Bart., F.G.S., &c., Elmore Court, near Gloucester. Gunn, Rev. J., M.A., Local Secretary, Irstead Rectory, Norwich. Guppy, R. Lechmere, Esq., F.G.S., Government House, Trinidad. 10. Hall, Hugh F., Esq., F.G.S., 17, Dale Street, Liverpool. Hall, Townshend M., Esq., F.G.S., Pilton Parsonage, Barnstaple. Hamilton, W. J., Esq., F.R.S., G.S., &c., President, 23, Chesham Place, Belgrave Square, S.W. Hanson, Samuel, Esq., 47, Botolph Lane, E.C.; and 43, Upper Harley Street, W. Harford, Frederick, Esq., Ocean Marine Insurance Company, 2, Old Broad Street, E.C. Harkness, Professor Robert, F.R.S., Queen’s College, Cork. | Harris, W., Esq., F.G.S., Charing, Ashford, Kent. Harrison, William, Esq., F.G.S., S.A., R.G.S., R. 8. Ant., &c., Local Secretary, Galligreaves Hall, Blackburn, Lancaster; and Conservative Club, St. James’s Street, S.W. Hartley Institution, Southampton (by Dr. F. T. Bond). Haughton, Rev. Professor 8., M.D., F.R.S., G.S., Fellow of Trinity College, Dublin. Hawkes, Rev. Henry, B.A., F.L.S., &c., Southsea, Portsmouth. Hawkins, B. Waterhouse, Esq., F..S., G.S., Belvedere Road, Upper Norwood, 8S. 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D., Esq., F.G.S., &c., Maison Cormalde, Nice. Hunter, J. R. S., Esq., Braidwood, Carluke, N.B. Hutton, R., Esq., F.G.S., M.R.LA., &c., Putney Park, S.W. Huxley, Professor T. H., LL.D., Ph.D., F.R.S., L.S., G.S., Museum of Practical Geology, Jermyn Street, S.W. Illingworth, Rev. BE. A., 3, Mecklenburgh Street, W.C. Illingworth, R. S., Esq., 9, Norfolk Crescent, W. Tlott, James William, Esq., Bromley, Kent. Ipswich Museum, Ipswich. J’Anson, E., Esq., 7a, Laurence Pountney Hill, E.C. James, Colonel Sir H., R.E., F.R.S., G.S., &c., Ordnance Survey, Southampton. Jarvis, Richard H., Esq., F.G.S., Beckenham, Kent, S.E. Jeffreys, J. Gwyn, Esq., F.R.S., L.S., G.S., 25, Devonshire Place, Portland Place, W. 11 Johnes, J. Esq., F.G.S., Dolancothy, Llandilo, Wales. Johnson, William, Esq., Eton College. Jones, John, Esq., F.G.S., Local Secretary, Dudley. Jones, Rear-Admiral T., F.L.S., G.S., &c., 18, Harcourt Street, Dublin. Jukes, J. Beete, Esq., M.A., F.R.S., F.G.S., &c., Geological Survey of Ireland, 51, Stephen’s Green, Dublin. Kenyon, Robert, Esq., 6, Lower Berkeley Street, Portman Square, W. Kenyon, the Hon. Mrs. Thomas, Pradoe, near Shrewsbury. King, W. P., Esq., Avonside, Clifton Down, Bristol. Kinnaird, Lord, Rossie Priory, Inchture, N.B. Kingston, G. S., Esq., Grote Street, Adelaide, South Australia. Knight, Captain E., 15, Elvaston Place, South Kensington, W. Krantz, Herr, Bonn. Lawrance, John, Esq., F.G.S., Elton, Oundle. Leckenby, John, Esq., F.G.S., Local Secretary, Scarborough. Lee, Henry, Esq., F.L.S., G.S., The Waldrons, Croydon, S. Lee, John Edward, Esq., F.G.S., The Priory, Caerleon, Monmouthshire. Leeds Library, Leeds, Yorkshire. Leicester Literary and Philosophical Society, Town Museum, Leicester. Leighton, W. H., Esq., 2, Merton Place, Turnham Green, W. Lemon, Sir C., Bart., F.R.S., G.S., &c., 30, Albemarle Street, W. Leonard, Edward J., Esq., Engineer’s Office, West India Docks, E. Lightbody, Robert, Esq., Ludlow. Lindsay, Charles, Esq. (by W. Stuart, Esq., Walbrook Buildings, Walbrook, E.C.) Lingard, John R., Esq., 4, Westminster Chambers, 8.W. Linnean Society, Burlington House, Piccadilly, W. Lister, J. J., Esq., F.R.S., &c., Upton, Essex. Lister, John, Esq., F.G.S., Shibden Hall, near Halifax. Literary and Philosophical Society of Manchester. Literary and Philosophical Society of Newcastle. Literary and Philosophical Society of Sheffield (by J. Holland, Esq., Music Hall, Sheffield). Liveing, Professor G, D., M.A., St. John’s College, Cambridge. Liverpool Free Public Library. Liverpool Natural History Society. Lloyd, John, Esq., 77, Suow Hill, E.C. Lloyd, J. H., Esq., 10, Lancaster Gate, W. London Institution, Finsbury Circus, E.C. Lovén, Professor 8., Stockholm. Lowry, J. W., Esq., F.R.G.S., 45, Robert Street, Hampstead Road, N.W. Lubbock, Sir John W., Bart., M.A., F.R.S., L.S., 15, Lombard Street, E.C. Lucas, Joseph, jun., Esq., Upper Tooting, Surrey. Lucas, John F., Esq., Middleton, Yolgrave, Bakewell, Derbyshire. Ludlow Natural History Society. Lyall, George, Esq., F.G.S., 38, Winchester Street, South Shields. Lyell, Sir C., Bart., M.A., F.R.S., L.8., G.S., &c., 538, Harley Street, Cavendish Square, W. 12 Lyon, Bibliothéque de la Ville de. Mackeson, Henry B., Esq., F.G.S., &c., Hythe, Kent. Mackey, Colonel, Fairhill, near Exeter. Maclean, William C., Esq., 5, Camperdown Terrace, Great Yarmouth. Macmillan, Messrs., Cambridge. McAndrew, R., Esq., F.R.S., Bond Street Chambers, Walbrook, E.C. McMorran, A., Esq., Cheapside, E.C. Maton, Professor B. Macredie, P. B. M., Esq., Perceton House, Irvine, N.B. Madras Government Museum (per Messrs. Williams and Norgate). Magendie, A., Esq., F.R.S., G.S., &c., Hedingham Castle, Castle Hedingham, Essex. Major, Charles, Esq., Red Lion Wharf, Upper Thames Street, E.C. Mann, C. S., Esq., F.G.S., Eltham, Kent, 8.E. Mansel, John, Esq., F.G.S., Longthorns, Blandford, Dorset. Marés, Mons. P., Paris. 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James, M.A., &c., Blandford. Penruddocke, Charles, Esq., Compton Park, near Salisbury. Perceval, Spencer George, Esq., Severn House, Henbury, Bristol. Perkins, Rev. R. B., Wootton-Underedge, Gloucestershire. Phillips, John, M.A., LL.D., F.R.S., G.S., &c., Professor of Geology in the University of Oxford, Local Secretary, Museum, Oxford. Philosophical Society of Glasgow. Phear, Rev. George, F.G.S., Emmanuel College, Cambridge. Phené, John S., Esq., 34, Oakley Street, Chelsea, S.W. Pickering, John, Esq., 29, Loraine Road, Upper Holloway, N. Pictet, Mons. F. J., Professor of Zoology, Academy of Geneva. Pidgeon, Jonathan 8., Esq., Pembridge Villa, Bayswater, W. Plant, James, Esq., Local Secretary, 4, Napier Terrace, Leicester. Pollock, Lady, Clapham Common, 8. Portal, Wyndham §8., Esq., Malshanger House, Basingstoke. Porter, Henry, M.D., F.G.S., Peterborough. Portman, Hon. Miss, 5, Princes Gate, Hyde Park, S.W. Poynton, Rev. Francis, Rectory, Kelston, Bath. 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Young, James, Esq., Burr Street, Tower Hill, E. Zoological Society of London, 11, Hanover Square, W. ww 18 CATALOGUE OF WORKS ALREADY PUBLISHED BY THE PALZONTOGRAPHICAL SOCIETY: Showing the OrvER of publication; the Years during which the Society has been in operation ; and the ContEnts of each yearly Volume. Vol. I. Issued for the Year 1847 The Crag Mollusca, Part I, Univalves, by Mr. S. V. Wood, 21 plates. 10% ” 5 ue 59 Lis af haa fs plates. on { The Reptilia of the London Clay, Part I, Chelonia, &., by Profs. Owen and Bell, 38 The Eocene Mollusca, Part I, Cephalopoda, by Mr. F. E. Edwards, 9 plates. The Entomostraca of the Cretaceous Formations, by Mr. T. R. Jones, 7 plates. The Permian Fossils, by Prof. Wm. King, 29 plates. 1849 3 The Reptilia of the London Clay, Part II, Crocodilia and Ophidia, &c., by Prof. Owen, 18 plates. The Fossil Corals, Part I, London Clay, by Messrs. Milne-Edwards and Jules Haime, t 11 plates. f | The Crag Mollusca, Part II, No. I, by Mr. S. V. Wood, 12 plates. 1880 The Mollusca of the Great Oolite, Part I, Univalves, by Messrs. Morris and Lycett, 15 plates. The Fossil Brachiopoda, Part III, No. I, Oolitic and Liassic, by Mr. Davidson, 13 plates. The Reptilia of the Cretaceous Formations, by Prof. Owen, 39 plates. 1851 ee Fossil Corals, Part II, Oolitic, by Messrs. Milne-Edwards and Jules Haime, 19 plates. The Fossil Lepadide, by Mx. Charles Darwin, 5 plates. r The Fossil Corals, Part III, Permian and Mountain-limestone, by Messrs. Milne- Edwards and Jules Haime, 16 plates. _, | The Fossil Brachiopoda, Part I, Tertiary, by Mr. Davidson, 2 plates. 1852 4 The Fossil Brachiopoda, Part II, No. I, Cretaceous, by Mr. Davidson, 5 plates. The Fossil Brachiopoda, Part III, No. 2, Oolitic and Liassic, by Mr. Davidson, 5 plates. The Eocene Mollusca, Part II, Pulmonata, by Mr. F. E. Edwards, 6 plates. The Radiaria of the Crag, London Clay, &c., by Prof. E. Forbes, 4 plates. 19 CATALOGUE OF WORKS—Continued. f The Fossil Corals, Part IV, Devonian, by Messrs. Milne-Edwards and Jules Haime, 10 » plates. The Fossil Brachiopoda, Introduction to Vol. I, by Mr. Davidson, 9 plates. Vol. VII. Issued for the Year 4 The Mollusca of the Chalk, Part I, Cephalopoda, by Mr. D. Sharpe, 10 plates. 1853 | The Mollusca of the Great Oolite, Part II, Bivalves, by Messrs. Morris and Lycett, 8 plates. L The Mollusca of the Crag, Part II, No. 2, Bivalves, by Mr. 8. V. Wood, 8 plates. The Reptilia of the Wealden Formations, Part I, Chelonia, by Prof. Owen, 9 plates. f The Fossil Brachiopoda, Part II, No. 2, Cretaceous, by Mr. Davidson, 8 plates. The Reptilia of the Wealden Formations, Part II, Dinosauria, by Prof. Owen, 20 plates. The Mollusca of the Great Oolite, Part ITI, Bivalves, by Messrs. Morris and Lycett, 7 plates. : sete --Weive: ; sae 46 , VILL. E #1954 The haat Dain Part V, Silurian, by Messrs. Milne-Edwards and Jules Haime The Fossil Balanide and Verrucide, by Mr. Charles Darwin, 2 plates. The Mollusca of the Chalk, Part II, Cephalopoda, by Mr. D. Sharpe, 6 plates. The Hocene Mollusca, Part III, No. 1, Prosobranchiata, by Mr. F. E. Edwards, 8 L plates. f The Mollusca of the Crag, Part II, No. 3, Bivalves, by Mr. S. V. Wood, 11 plates. The Reptilia of the Wealden Formations, Part ITI, by Prof. Owen, 12 plates. | The Eocene Mollusca, Part III, No. 2, Prosobranchiata continued, by Mr, F. E. Exe a +1855 4 Edwards, 4 plates. | The Mollusca of the Chalk, Part III, Cephalopoda, by Mr. D. Sharpe, 11 plates. | The Tertiary Entomostraca, by Mr. T. R. Jones, 6 plates. L The Fossil Echinodermata, Part I, Oolitic, by Dr. Wright, 10 plates. f The Fossil Echinodermata, Part II, Oolitic, by Dr. Wright, 12 plates. The Fossil Crustacea, Part I, London Clay, by Prof. Bell, 11 plates. x 1856 The Fossil Brachiopoda, Part IV, Permian, by Mr. Davidson, 4 plates. a ae 2 ; The Fossil Brachiopoda, Part V, No. 1, Carboniferous, by Mr. Davidson, 8 plates. | The Reptilia of the Wealden Formations, Part IV, by Prof. Owen, 11 plates. L The Reptilia of the London Clay (Supplement), by Prof. Owen, 2 plates. The Fossil Echinodermata, Part III, Oolitic, by Dr. Wright, 14 plates. XI 1857 < The Fossil Brachiopoda, Part V, No. 2, Carboniferous, by Mr. Davidson, 8 plates. a3, Se ” [ The Reptilia of the Wealden Formations, Part V, by Prof. Owen, 12 plates. The Polyzoa of the Crag, by Prof. Busk, 22 plates. ( The Fossil Echinodermata, Part IV, Oolitic, by Dr. Wright, 7 plates. | The Hocene Mollusca, Part III, No. 3, Prosobranchiata continued, by Mr. F. E. 7 1858 ¢ Edwards, 6 plates. | The Reptilia of the Cretaceous and Purbeck Formations, by Prof. Owen, 8 plates. The Fossil Brachiopoda, Part V, No. 3, Carboniferous, by Mr. Davidson, 10 plates. The Reptilia of the Oolitic Formations, No. 1, by Prof. Owen, 7 plates. The Eocene Mollusca, Part IV, No. 1, Bivalves, by Mr. 8. V. Wood, 13 plates. The Fossil Brachiopoda, Part V, No. 4, Carboniferous, by Mr. Davidson, 20 plates. Pp S008 - 1859 | * This Vol. is marked on the outside 1855. + This Vol. is marked on the outside 1856. Vol. XIV. Issued for the Year fp: ayo. yy CANE , XVIII. 53) LE, 9 ey 20 CATALOGUE OF WORKS—Continued. The Reptilia of the Oolitic Formation, No. 2, by Prof. Owen, 12 plates. The Fossil Estherie, by Prof. Rupert Jones, 5 plates. The Fossil Crustacea, Part II, Gault and Greensand, by Prof. Bell, 11 plates. The Fossil Brachiopoda, Part V, No. 5, Carboniferous, by Mr. Davidson, 8 plates. 1860 | lates. bes Fossil Echinodermata, Vol. II, Part I (Oolitic Asteroidea), by Dr. Wright, 13 1861 Supplement to the Great Oolite Mollusca, by Dr. Lycett, 12 plates. ¢ The Fossil Echinodermata, Cretaceous, Vol. I, Part I, by Dr. Wright, 11 plates. The Trilobites of the Silurian, Devonian, &c., Formations, Part I, by Mr. J. W. Salter, 6 plates. 1862 < The Fossil Brachiopoda, Part VI, No. 1, Devonian, by Mr. Davidson, 9 plates. The Eocene Mollusca, Part IV, No. 2, Bivalves, by Mr. 8. V. Wood, 7 plates. lL The Reptilia of the Cretaceous and Wealden Formations (Supplements), by Prof. Owen, 10 plates. ( The Trilobites of the Silurian, Devonian, &c., Formations, Part II, by Mr. J. W Salter, 8 plates. 1863 < The Fossil Brachiopoda, Part VI, No. 2, Devonian, by Mr. Davidson, 11 plates. | The Belemnitide, Part I, Introduction, by Prof, Phillips. L The Reptilia of the Liassic Formations, Part I, by Prof. Owen, 16 plates. r The Fossil Echinodermata, Vol. II, Part II (Liassic Ophiuroidea), by Dr. Wright, 6 plates. | The Trilobites of the Silurian, Devonian, &c., Formations, Part III, by Mr. J. W. Salter, 11 plates. 1864 J The Belemnitidx, Part II, Liassic Belemnites, by Prof. Phillips, 7 plates. | The Pleistocene Mammalia, Part I, Introduction, Felis spelea, by Messrs. W. Boyd Dawkins and W. A. Sanford, 5 plates. | Title-pages, &c., to the Reptilia of the London Clay, Cretaceous, and Wealden For- L mations. The Crag Foraminifera, Part I, No. 1, by Messrs. T. Rupert Jones, W. K. Parker, and H. B. Brady, 4 plates. 1865 3 Supplement to the Fossil Corals, Part I, Tertiary, by Dr. Duncan, 10 plates. The Fossil Merostomata, Part I, Pterygotus, by Mr. H. Woodward, 9 plates. | The Fossil Brachiopoda, Part VII, No. 1, Silurian, by Mr. Davidson, 12 plates. Supplement to the Fossil Corals, Part IV, No. 1, Liassic, by Dr. Duncan, 11 plates. | The Trilobites of the Silurian, Devonian, &c., Formations, Part IV (Silurian), by Mr. 1866 3 J. W. Salter, 6 plates. | The Fossil Brachiopoda,Part VII, No. 2, Silurian, by Mr. Davidson, 10 plates. \ The Belemnitide, Part III, Liassic Belemnites, by Prof. Phillips, 13 plates. LIST OF MONOGRAPHS Completed, in Preparation, and in course of Publication.* MONOGRAPHS which have been CompLetep :— The Tertiary, Cretaceous, Oolitic, Devonian, and Silurian Corals, by MM. Milne-Edwards and J, Haime. The Tertiary Echinodermata, by Professor Forbes. The Fossil Cirripedes, by Mr. C. Darwin. The Tertiary Entomostraca, by Prof. T. Rupert Jones. The Cretaceous Entomostraca, by Prof. T. Rupert Jones The Fossil Estheriz, by Prof. T. Rupert Jones. The Polyzoa of the Crag, by Mr. G. Busk. The Tertiary, Cretaceous, Oolitic, Liassic, Permian, Carboniferous, and Devonian Brachiopoda, by Mr. T. Davidson. The Mollusca of the Crag, by Mr. 8S. V. Wood. The Great Oolite Mollusca, by Professor Morris and Mr. J. Lycett. The Cretaceous (Upper) Cephalopoda, by Mr. D. Sharpe. The Fossils of the Permian Formation, by Professor King. The Reptilia of the London Clay (and of the Bracklesham and other Tertiary Beds), by Professors Owen and Bell. The Reptilia of the Cretaceous, Wealden, and Purbeck Formations, by Professor Owen. MONOGRAPHS which are in course of Preparation :*— The Flora of the Tertiary Formation, by Mr. W. S. Mitchell. The Flora of the Carboniferous Formation, by Mr. E. W. Binney. The Cretaceous Foraminifera, by Messrs. T. Rupert Jones, W. K. Parker, and H. B. Brady. * Members having specimens which might assist the authors in preparing their respective Monographs are requested to communicate in the first instance with the Honorary Secretary. 22 MONOGRAPHS in course of Preparation—Continued. The Foraminifera of the Lias, by Mr. H. B. Brady. The Graptolites, by Professor Wyville Thomson. The Crinoidea, by Professor Wyville Thomson. The Post-Tertiary Entomostraca, by the Rev. H. W. Crosskey and Messrs. G. S. Brady and D. Robertson. The Wealden, Purbeck, and Jurassic Entomostraca, by Messrs. T. Rupert Jones and G. 8S. Brady. The Bivalve Entomostraca of the Carboniferous Formation, by Messrs. T. Rupert Jones and J. W. Kirkby. The Phyllopoda of the Paleozoic Rocks, by Mr. J. W. Salter. The Polyzoa of the Chalk Formation, by Mr. G. Busk. The Post-Tertiary Mollusca, by Mr. J. Gwyn Jeffreys. The Cretaceous Mollusca (exclusive of the Brachiopoda), by the Rev. T. Wiltshire. The Purbeck Mollusca, by Mr. R. Etheridge. The Inferior Oolite Mollusca, by Mr. R. Etheridge. The Rheetic Mollusca, by Mr. R. Etheridge. The Liassic Gasteropoda, by Mr. Ralph Tate. The Ammonites of the Lias, by Dr. Wright. The Fishes of the Old Red Sandstone, by Messrs. J. Powrie and E. Ray Lankester. The Crag Cetacea, by Professor Owen. MONOGRAPHS in course of PuBLication :— The Crag Foraminifera, by Messrs. T. Rupert Jones, W. K. Parker, and H. B. Brady. Supplement to the Fossil Corals, by Dr. Duncan. The Echinodermata of the Oolitic and Cretaceous Formations, by Dr. Wright. The Fossil Merostomata, by Mr. H. Woodward. The Trilobites of the Mountain-Limestone, Devonian, and Silurian Formations, by Mr. J. W. Salter. The Eocene Mollusca, by Messrs. F. E. Edwards and 8. V. Wood. The Silurian Brachiopoda, by Mr. Davidson. The Belemnites, by Professor Phillips. The Pleistocene Mammalia, by Messrs. Boyd Dawkins and W. A. Sanford. The Reptilia of the Liassic Formations, by Professor Owen. 23 Dates of the Issue of the Yearly Volumes of the Paleontographical Society. The Volume for 1847 was issued to the Members, March, 1848. 1848 a “7 a July, 1849. me 1849 33 y rh August, 1850. ». 1850 3 ay = June, 1851. ad 1851 fe os os June, 1851. 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Uw? wo ‘ajoydmoa “Uunjod MNOOAS ayz2 urs : (ZO8T “ANOL 02 dn) SUTANAT. GANG OL GaaAssr SHdVUNONO]YT FHL JO AUVINNIG > r a seid \ > « ‘ - ~ | ce. - © . 7 i } ee?) ak A ‘eo Le (ee Pp ; oh % on Ne eae by aye ay aD, ; ies ¢ é i; oy 7 ~ * a” ly * - } . ‘ 4 ' . ry, = — 4, . . ‘o ee aia’ | : NON a Same ae! eit i oe ‘= pee oe - =) > SF ion - PALHONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVII. VOLUME FOR 1866. LONDON: MDCCCLXVII. - ars ‘ hee oe s ba hao TAOS ' fs > . ; . “a on a. i a i , ad 4 . 7 Ae ou é mS ae ees es A MONOGRAPH OF THE BRITISH FOSSIL CORALS. SECOND SERIES. BY P. MARTIN DUNCAN, M.B. LOND., F.G.S., SECRETARY TO THE GEOLOGICAL SOCIETY. Being a Supplement to the ‘Monograph of the British Fossil Corals, by MM. Mitnz-Epwarps and Jutes Haine. PART IV, No. 1. CoRALS FROM THE ZONES OF AMMONITES PLANORBIS AND AMMONITES ANGULATUS IN THE Liassic ForRMATION. Pages i, ii; 1—43; Plates I—XI. LONDON: PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY. 1867. ‘ oer << a a —J hs +3 (hr oy, cee 0 ALORU Vie WD OE REPAY fe aati ai f ico a) vith hel ay : 1 } a iJ* ve * : ea A: 4 n - }, 4 ‘ - LO : a i . a . =i ‘oe Aas a ITf. EV: Ne VE VIl. CONTENTS. PREFACE . ep eee : : : : : E INTRODUCTION TO THE STUDY OF THE Liasstc CorRALs ; : DESCRIPTION OF THE SPECIES CONTAINED IN THE ZONE OF AMMONITES PLANORBIS DESCRIPTION OF THE SPECIES CONTAINED IN THE ZONE OF AMMONITES ANGULATUS, IN THE Sutton Stone, AND IN DEPOSITS AT BrocastLE, EWENNY, AND Cow- BRIDGE, IN GLAMORGANSHIRE. List OF THE SPECIES p : é DESCRIPTION OF THE SPECIES FROM THE ZONE OF AMMONITES ANGULATUS AT Marton, NEAR GAINSBOROUGH P ; ; . DESCRIPTION OF THE SPECIES FROM THE ZONE OF AMMONITES ANGULATUS IN THE Norte orf [IRELAND . ; e k Z : : DESCRIPTION OF THE SPECIES FROM LUSSAY, IN THE ISLE OF SKYE LisT OF THE SPECIES DESCRIBED AND NOTICED IN THIS PART b PAGE 42 id a Se mY me die ae A {hm aA OYA att tL i eee at i GieriaahO Faire eA te rhe A A Uy vie ie “co Mali | 2 , Aah it by ae it cai a or somal A MONOGRAPH OF THE BRITISH FOSSIL CORALS. SHCOND SERIES. Part IV. No. 1. PREFACE. Ir was noticed in the Preface to the First Part of this series that some irregularity in the succession of the Monographs would occur. According to the plan adopted by MM. Milne-Edwards and Jules Haime, the Corals of the Cretaceous rocks should have been described in this Part; but it was found advisable to take advantage of Mr. Charles Moore’s splendid collection of Liassic Madreporaria, and to describe the species contained in it at once. MM. Milne-Edwards and Jules Haime only described three species from the whole of the British Lias ; and as one was probably a remanié fossil,’ and another could not be determined generically,’ only one good species, Zrochocyathus Moorei, Ed. and H., remained to characterise this great formation. ; Since those authors wrote, many careful collectors have found large numbers of Corals in the Middle and Lower Lias ; and Dr. Wright,’ the Rev. P. B. Brodie,* and Mr. Ralph Tate,’ have published notices and descriptions of species. Lately Mr. Tawney and the author brought the Corals of the Sutton Stone® before the notice of the Geological Society; and Mr. Charles Moore, who had long before ' «Monograph. Brit. Foss. Cor.,’ p. 145, Paleeontograph. Soe., 1851. 2 Tbid. 3 ‘Quart. Journ. Geol. Soc.,’ 1857, p. 34. * «Reports of the British Association for 1860, Reports of Sections,’ p. 73. ‘ Quart. Journ. Geol. Soc.,’ 1860, vol. xvii, p. 151. “A Sketch of the Lias, &c.,” ‘Transact. Woolhope Nat. Field Club,’ No. 1. > ‘Quart. Journ. Geol. Soc.,’ vol. xx, p. 111. 6 [bid., vol. xxii, p. 91. il PREFACE. collected Sutton Stone Corals, and had discovered the highly fossiliferous deposit at Brocastle, forwarded me his specimens, which are about to be described. The above- mentioned geologists have afforded me all the information at their command; and Messrs. Kershaw, Winwood, Boyd Dawkins, Burton, Chamberlin, and Mrs. Strickland, have placed me under great obligations. Finding that at least fifty new species would have to be added to the list of British Liassic Corals, it was thought advisable to publish the most important at once. This Part of the Second Series will refer to the Corals of that portion of the Lower Lias which intervenes between the Rheetic strata and the beds which contain Ammonites Bucklandi (bisulcatus) and Gryphea incurva (type) mm abundance.’ The next portion of this Monograph (Part IV, No. 2) will contain the description of the Corals of the other beds of the Lower Lias, and of the forms in the Middle and Upper Liassic deposits. It is probable that several Liassic beds whose geological horizon is not yet determined may yield new species of Corals which will have to be associated with those of the zone of Ammonites angulatus, and they will, of necessity, be mcluded in Part IV, No. 2, in which the lists of the species will be given, with a notice of the Corals of the Liassic strata of Continental Europe. Owing to the paucity of specimens, it is thought advisable to defer the consideration of the species from the White Lias of the Rheetic series and from the Zone of Avicula contorta to a future occasion. ! Madreporaria of the Infra-Lias of South Wales. P. Martin Duncan, ‘ Quart. Journ. Geol. Soc.,’ Feb., 1867. + A MONOGRAPH OF THE BRITISH FOSSIL CORALS. (SECOND SERIES.) Parr [V.—No. 1. INTRODUCTION. Tur Corals contained in the Liassic strata of Britain, France, Germany, and Italy have a very decided community of facies; at the same time it is evident that some portions of the Liassic Coral-fauna resemble Triassic types, and that another portion is allied to the Oolitic. This was to be expected, for it is evident that the stunted Zhecosmilia, and the Astrocenie of the Zone of Ammonites angulatus, are the descendants of the equally stunted Thecosmilie@ and of the Astrocenia of the Triassic age. Moreover, the descendants of the Zsastree, and of the larger Montlivaltie of the Lower and Middle Lias, luxuriated in the Oolitic seas. ; The bulk of the Liassic Coral-fauna is, however, characteristic of and special to the formation; and, as is the case in other great series of strata, certain assemblages of species appear to characterise certain definite geological horizons. Yet not unex- ceptionably, for some species range into higher zones in certain areas, whilst others, which are confined to a definite horizon in one area, are found below and above the equivalents of the horizon in a distant locality. Thus a species, which is only found in a particular bed, and is associated with a particular molluscan fauna in one locality, may be found to be associated with a molluscan fauna antecedent or posterior in its recognized succession, in another place. It is this uncertain vertical range of species, this variation in vertical range in different geographical areas, which causes the apparent antagonism of Physical Geology (as applied to Classificatory Geology) and Paleontology. 1 2 BRITISH FOSSIL CORALS. It is this coming in of the same species at various positions in a large formation and their association with different groups of species that renders Paleontology of more or less uncertain value in the exact determination of the age of strata. But it is this varying vertical range of species in different areas and their association with different groups of forms that points to an ever-changing life-scene, to migration of faunee, to changes of physical conditions, to variation in the intensity of competition, to the rise of dominant and the decay of feeble forms, and to all those external agencies which affect the inherent power of variation peculiar to the animated nature of this world, where no two things are exactly alike. The persistence of a species in a succession of strata, and its consecutive association with different groups of competitors and contemporaries, is constantly observed in the Lias, taken as a whole; and it is the strongest fact that can be adduced against the almost exploded notion of a series of cataclysmal destructions and of successive creations of beings occurring at intervals which are denoted by changes in physical geology. It is necessary to assert that those doctrines are not quite exploded, for they have a deep hold on the minds of many who have only a limited area of geological observation. The disposition to limit the possibility of the occurrence of certain specific forms to definite vertical ranges arises from a partial belief in those ideas, and they are apparently strengthened in the force of their application when physical breaks accompany palzonto- logical changes. Here the question concerning the physical causes which permit of and assist in the preservation of dead organisms must be considered in reference to those which have a diametrically opposite effect. If it be admitted that when the terrestrial conditions are in statu quo the preservation of organic remains from destruction is hardly possible ; that during elevation of areas the entombment and fossilization of organisms is equally unlikely, and that a gradual depression of the surface is in the majority of instances necessary for the preservation of deposits, it becomes evident that, whilst the physical break has a diminished value in its relation to the persistence of the life of species, the existence of a species in a considerable series of strata which could not have all been deposited during a continuous and uninter- rupted sinking of their area becomes most suggestive. ‘Taken in combination with the remarks which have preceded, it is suggestive of the evident want of relation between the formation of strata and the origin and decadence of the species of the period ; and it points out that no Stratigraphical Paleeontogeology can be perfect in a classificatory sense, and that zones of species may have little to do with the notion of time. With an ever-progressing animated nature there are and have ever been associated terrestrial and inorganic changes. ‘There is no definite connection between them, and hence our classificatory systems have an increment of error which is constantly rising to the surface when the pure physical geologist and the pure paleontologist argue upon their own bases concerning the age of strata. INTRODUCTION. 3 The notion that the succession of strata all over the world must be upon the same plan as that of the best studied, typical or most familiar district favours thus difficulty ; and it is most true that the Lias has been, from the applicability of the foregoing remarks, a very debateable ground. The relation of the Bone-bed to the Trias; the propriety of forming a Rheetic series ; its relation to the Trias and Lias ; the possibility of arranging the strata of the Lias in Zones of Ammonite life ; the propriety of including the Liassic strata between the Keuper and the Zone of Ammonites Bucklandi, or between the base of the Zone of Ammonites planorbis and the Zone of Ammonites Bucklandi in a sub-group, calling it Infra-Lias ; the possibility of separating the Zone of Ammonites Bucklandi from the Zone of Ammonites angulatus, and the impropriety of distinguishing Zones of Cephalopoda, Insecta, Sauria, or Madreporaria —all these have been points debated over and over again, and they will ever be so as long as artificial distinctions are placed “en rapport” with nature. Nevertheless, carefully collected paleontological data concerning the vertical range of species are gradually deciding many of these questions, and with the effect of isolating the paleontologist more and more in his relations with the received classificatory geology. ‘These remarks are made because it is necessary to give the various groups of species of Madreporaria of the Lias places in some classification or other. It is impossible to associate them with beds determinable on purely stratigraphical or mineralogical data ; and it is equally impossible to include them in Zones of special life, for Cephalopoda and Saurians are rarely in relation with Corals. 'The groups of A/adreporaria have a general relation to certain zones of life and to certain strata; and if they are associated for the sake of a necessary classification with certain Ammonite-Zones, it must be understood that it is only an approximative classification, and that both the Ammonites and the Madre- poraria may range out of their supposed restricted zone, or not even be represented in certain portions of its area. If it be admitted that by a Zone of an Ammonite or of any other Mollusc the general and usual vertical limit of the species is meant, all the difficulties thrown in the way of the philosophical, but still artificial, separation of the Liassic series into Ammonite- Zones vanish. Dr. Wright has elaborated this system in his ‘Monograph of the Oolitic As- teriade,”* and had his Zone of Ammonites angulatus been known to have been as well developed in Glamorganshire and in Lincolnshire as it is in some of its most typical districts in France, his arrangement would have met with slight opposition. But the endeavour to give definite horizons to and to correllate Saurian, Insect, Ostrea, Ammonite, and Zima beds has resulted in the production of confusion instead of the reverse. Whether the principle of the arrangement in’Zones of Ammonites is admitted or not, it is absolutely necessary that the foreign equivalents of our Liassic subdivisions should 1 Pal. Soc. 4 BRITISH FOSSIL CORALS be studied. If this be done the association of the characteristic species of certain British beds with the characteristic species of a lower geological horizon on the Continent becomes evident, and the unphilosophical nomenclature of geologists who restrict themselves to the study of small areas is exposed. In classifying the groups of species about to be described, in the geological scale attention will be directed to the Ammonite-Zone in which they are found and to the Mollusca associated with them. There are a few Triassic species in the Liassic Coral-fauna, and the Branching Corals of the Sutton Stone have, generally speaking, a very Triassic facies. The majority of the Corals of the lowest members of the Lias are peculiarized by the imperfection of their septal arrangement: the distinct development of definite cycles in six systems is rarely observed, and it would appear that this high organization was not attained in the forms which had varied from Paleeozoic into Mesozoic species. The Montlivaltie, Thecosmilia, and Astrocenia of the Lower Lias of Glamorganshire illustrate this remark ; and the first definite septal arrangement is met. with in the Montlivaltia Haimei, Ch. et Dew, in the Zone of Ammonites angulatus at Marton. The septal number is also very uncertain in the species of the above-mentioned genera in the Lower Lias, and multiseptate Montlivaltie are found in the same deposit as those possessing an unusually small number of septal lamin. It may, in fact, be asserted that the so-called rwgose peculiarities had hardly left their hold upon Madreporarian life at the time when the lowest members of the Lias were deposited. The genus Hysastrea, Laube, retains some “rugose” peculiarities, and the transition from the tabule and vesicular endotheca of a Cyathophyllum to the dissepiments and vesicular endotheca of some forms of Montlivaltia polymorpha, Terq. et Piette, is certainly within the bounds of possibility. Nevertheless, no Paleozoic genera of Corals have been found in the Lias except as “remanié” fossils. The genera which are represented in those subdivisions of the Lias called the Zones of Ammonites planorbis and Ammonites angulatus are— I. Montlivaltia. Il. Rhabdophyllia. Ill. Thecosmilia. IV. Oppelosmilia, gen. nov. V. Lsastrea. VI. Astrocenia. VII. Cyathocenia, gen. nov. VIL. Lysastrea. IX. Septastrea. X. Latimeandra. FROM THE ZONE OF AMMONITES PLANORBIS. 5 No Tubulate nor Perforate genera have been discovered; yet as they existed both in palzeozoic times, and in formations more recent than the Lias, they doubtlessly will be found. The multitude of branching TZhecosmilie, stunted Montlivaltig, and small-caliced Astroceni@, give the peculiar facies to the Coral-fauna of these members of the Lower Lias. II. Corats FROM THE ZONE OF AMMONITES PLANORBIS. The yellow shale in the section at Street which contains Ammonites planorbis and Ichthyosaurus intermedius has yielded a large and well-preserved specimen of the genus Septastrea.._ At Binton there are said to be Corals in the “ Guinea’ bed,” but no specimens could be obtained. Section—APOROSA. Famiry—ASTRAID &. Division—F aviacka. Genus—SEPTASTR#A.®. 1. Seprasrr#a Hamer, Wright, sp. Pl. I, figs. 1—5. The corallum is massive, tall, club-shaped, and rather gibbous. The shape is generally sub-cylindrical, the base is small and conical, and the top is large and convex. The calices cover the corallum, are very numerous, and are separated by rather thick and united walls. ‘The calices are irregular in size, shallow, and more or less polygonal ; and they have a tendency to elongate at one end, as well as to divide fissiparously. The septa are irregular im size, shape, and number; they are small, unequal, rather distant, and the only ornamentation is an ill-defined swelling here and there. ‘They are not exsert; the smallest reach but a slight distance from the wall, but the larger occasionally reach the centre of the calice and unite. . Fissiparity is produced by two large septa stretching across the calice and developing others from their sides. The septa vary in number, from thirty to forty, but no cyclical arrangement is distinguishable. The endotheca is rather plentiful. 12 Wright, ‘Monogr. Oolitic Asteriadz, Pal. Soc.,’ p. 5 and p. 10. 3 «Hist. Nat. des Corall.,’ vol. ii. 6 BRITISH FOSSIL CORALS. Height of corallum, 7 inches. Breadth, 4} inches. Diameter of calices, 3ths to ths inch. Locality. Street, Somersetshire. In the Collection of Dr. Wright, F.G.S. The genus Septastrea resembles Jsastrea; but there is fissiparous growth in the calices of the first, and never in the calices of the last-named genus. The peculiar calicinal gemmation of Jsastrea never produces septa which, crossing the calice, divide it off into separate individuals. The walls of Septastrea are not so perfectly united as in Isastrea. 'The genus is found in the Lias and in the Tertiary Coral-fauna. The shape of the corallum and the septal structures and arrangement distinguish the species from Septastrea excavata,' K. de From., and Septastrea Fromenteh, Terquem et Piette. III. Corats From THE ZONE OF AMMONITES ANGULATUS. _ The Sutton Stone’ and the deposits at Brocastle, Ewenny, and Cowbridge,* are highly coralliferous beds in Glamorganshire. They rest on the Mountain-limestone, and are covered by members of the Lias higher in the series than the Zone of Ammonites angulatus. They have the homotaxis* of the Continental strata, which are classified within the Zones of Ammonites angulatus and Ammonites moreanus, such as the Calcaire de Valogne, the Foie de Veau, in the Cote d’Or, and the Gres Calcareux, in the Duchy of Luxembourg. Their British equivalent strata are well shown at Marton, near Gainsborough, and in Treland® near Belfast, besides in the localities mentioned by Dr. Wright.® ' Dr. Wright named this Coral Isastr@a Haimei, and noticed its specific distinction from Isastrea Murchisoni, Wright. Its genus is evidently Septastrea, and although Dr. Wright has not published a specific diagnosis of the form, still it is just that it should retain his name. He is answerable for its discovery in the locality given above. ? Sir Henry de la Beche, ‘Mem. Geol. Survey,’ vol. i, p. 270; Mr. Tawney, and P. Martin Duncan, ‘Quart. Journ. Geol. Soc.,’ vol. xxii, p. 69. ° Mr. Charles Moore discovered the Brocastle and Ewenny deposits some years before Mr. Tawney drew attention to the Sutton Stone. He collected a vast number of fossils from them, and forwarded them to me for examination. His able essay on “‘ Abnormal Conditions of Secondary Deposits,” &c., was read before the Geological Society, March 20th, 1867. See my notice of Mr. Chas. Moore’s labours, ‘ Quart. Journ. Geol. Soc.,’ Feb. 1867, p. 13. See also “On the Lower Lias or Lias-Conglomerate of a Part of Glamorganshire,” by H. W. Bristow, F.R.S.; “On the Zone of Ammonites angulatus in Britain,” by R. Tate, F.G.S. * “On the Madreporaria of the Infra-Lias of South Wales,” by P. Martin Duncan, ‘Quart. Journ. Geol. Soc.,’ 1866, Feb., p. 12. See also Terquem et Piette, ‘Mém. de la Soc. Géol. de la France,’ 2de série, tome 8, 1865. * R. Tate, ‘ Quart. Journ. Geol. Soc.,’ vol. xx, No. 78, p. 103. ® Wright, ‘Monogr. Ool. Aster., Pal. Soc.,’ p. 13; see also Oppel’s ‘ Juraformation.’ FROM THE ZONE OF AMMONITES ANGULATUS. 7 Section—APOROSA. Famity—ASTRAID 2. Division—LitTHOPHYLLACEZ SIMPLICES. Genus—MONTLIVALTIA. There are seven species of the genus J/on/livaltia in the Sutton Stone and the deposits at Brocastle, and six of them are new forms, the seventh having already been described by MM. Terquem et Piette." Three of the species belong to the section of the genus which is characterised by forms having their bases and calices of equal width, and three others have a more or less turbinate shape, whilst one species is pedunculated. The discoid JJontlivaltig appear to be absent, although they are largely represented in the equivalent beds in the east of England and in the north of Ireland. 1. Monriivatt1a Watuiz, Duncan. Pi. VIII, figs. 5, 6, 7. The corallum is cylindro-conical in shape, the base is small, and the calice large, open, and shallow. The calice is surrounded with a well-marked margin, which is double in some places, and the smallest or rudimentary septa, which are barely visible in the true calice, are distinct on the outer rim. The septa are very unequal, but narrow and lamellar, and rather plain, but dentate internally. They are not exsert as regards the calicular margin, but curve upwards and then inwards, terminating by a process marked with at least two teeth. The fourth cycle of septa is incomplete, and the fourth and fifth orders are rudi- mentary when they exist ; so that the septal number is irregular. The rudimentary septa alternate with the larger. There are about thirty well-developed septa of unequal lengths, and between these are the rudimentary septa. Height of the corallum, §ths inch. Breadth of the calice, Zths inch. Locality.. Brocastle. In the Collection of Chas. Moore, Esq., F.G.S., Bath. The wide and shallow calice, the low septal number, and the capacious interseptal spaces characterise this species. * Terquem et Piette, ‘Mem. de la Soc. Géol. de la France,’ 2de série, tom. 8, 1865. 8 . BRITISH FOSSIL CORALS 2. Montuivatt1a Murcuisonra, Duncan. PI. VIII, figs. 10, 11,12. The corallum is short and turbinate: the peduncle is small, and the calice is large, deep, and open. ~ The epitheca is distinct and swollen out in some places, being slightly constricted in others. The calice is circular in outline, very deep, and has a sharp margin. The septa are numerous, very distinct, and very remarkable, both in their arrangement and relation to the costz. The largest septa are bluntly dentate and exsert; the rest are faintly dentate, and pass deeply into the fossa, and there are a few rudimentary septa. The rounded coste are continuous internally with the interseptal spaces, and the septa are continuous with inter- costal spaces (fig. 12). The cyclical arrangement of the septa is confused. There are forty-eight septa, but these do not appear to form four cycles in six systems, but to be arranged in four systems, there being four septa larger than the others. The height of the corallum is 3ths inch. The breadth of the calice is 3ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. The arrangement of the septa and the depth of the calice distinguish this species very readily. It has its mimetic Zhecosmilia in Thecosmilia Brodie, Duncan. 3. MontiivaLtiA PpoLymorpHA, Zerguem et Piette. Pl. VII, figs. 14, 15; Pl. VIII, figs. L—4 and 13—15. The corallum is simple, very variable in form, and has a thick and folded epitheca reaching to the calice, and is marked with fine and regular costes. The corallum is rather narrowly pediculate, or adheres by a portion of its base. In shape the coralhkim may be conical, oblong, or flattened. The calice is more or less deep, is either round or oval, and its margin is thin. The septa are numerous, have strong teeth on the upper margin, and are smooth laterally. There are five complete cycles, and the sixth is incomplete. MM. Terquem et Piette do not give the measurements of the Coral, but in their plate the height varies from 3 inch to 2! inches, and the calicinal diameter from { inch to 1} inch. ' «Le Lias Inférieur de l’Est de la France,’ p. 127, pl. xvi, figs. 17—21. FROM THE ZONE OF AMMONITES ANGULATUS. 9 MM. Terquem et Piette notice that the species is found in great abundance at St. Menge in a bed lower than that containing Gryphea incurva and between the strata containing Ammonites bisulcatus (Bucklandi) and A. angulatus. ‘The specimens from Brocastle show much of the anatomy of the Coral; and the high septal number and dense wall of the corallites when broken off short are well seen in them. The taller specimens are often denuded of their epitheca, and the highly developed and inclined endotheca is then well seen. One specimen had a broad base, but the others taper and become rather pedunculate. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 4, Montiivattia parasitica, Duncan. PI. IV, figs. 13, 14. The corallum is small, very short, has a base as broad as the calice, and is elliptical in outline. The calice is very shallow. The septa are few in number, are very irregular ; and the costz run a short distance down the sides of the corallum. The septa are stout and unequal in length, but not very much so in thickness. ‘The shorter septa bend towards and usually unite themselves to a larger septum. ‘There appear to be twelve large septa, and five of these had either one or two smaller septa joined on to them. ‘There would appear to be two complete cycles of equal septa, and that the tertiary cycle is incomplete. Length of the calice }inch. Height of the corallum 3th inch. Locality. The Sutton Stone. In the Collection of Charles Moore, Esq,., F.G.S., Bath. . The species is founded upon a specimen fixed upon an Astroccenian, and the extreme shortness, the attachment to a very wide base, and the union of the tertiary to the secondary septa, are very distinctive. 5. MonrnivaLtra stmpLex, Duncan. PI. anh, hes. Tory: The corallum is short, has a broad base, and an elliptical calice, which is very slightly broader than the base. The epitheca is strong, does not show any coste, and it reaches to the calicular margin. The calice is shallow, and has rather a wide margin. The septa are very few, very distant, slender, and curved: their arrangement is very 2 10 BRITISH FOSSIL CORALS irregular ; and although there are six septa which reach nearer the calicular centre than the others, still no cyclical development can be asserted to have existed. There are sixteen septa; three are rudimentary, and there are thirteen of a larger size. Height of corallum, 2ths inch. Long diameter of calice, 4ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. The paucity of septa and the shape distinguish this remarkable species. 6. MontuivaLtia BREVIS, Duncan. Pl. VIII, figs. 8, 9. The corallum is short and cylindrical, and has a base as broad as the calice. The calicular margin is sharp, and the calice is rather irregular in shape: the calicular fossa is shallow, and the septa are few in number. The septa are unequal, distant, stout, and have a large tooth at the internal end. This dentation is more distinct in the secondary and tertiary cycles than in the primary. There are three cycles of septa, but the third is incomplete. The primary septa are the longest, and reach to the central space, whilst the smallest septa end in a blunt knob, not so near the central space as the termination of the intermediate septa. Height of the corallum, th inch. Breadth of the calice, ; inch. Locality. Brocastle. In the Collection of Charles Moore, F.G.S., Bath. The septa are very characteristic of this short and widely based Coral. 7. MonTLIVALTIA PEDUNCULATA, Duncan. PI. II, figs. 12, 13; Pl. VIII, fig. 16. The corallum is large above, cylindro-conical midway, and finely pedunculate at the base. The epitheca is thin, rather but finely ridged transversely, and permits the costz which are small to be seen where it is very scanty. The calice is not symmetrical, and the septa are numerous, and apparently constitute five cycles, and part of a sixth. The peduncle is much smaller than the body of the corallum. Height of corallum 3ths inch. Width of the calice ths inch. Locality. In the Sutton Stone, and at Brocastle. In the Collection of Charles Moore, Esq., F.G.S., and in the Museum of Practical Geology, London. The shape and high septal number distinguish this species. FROM THE ZONE OF AMMONITES ANGULATUS. LE Division —LitTHOPHYLLACEZ CASPITOS#. Genus.—THECOSMILIA. The Zhecosmilie of the Sutton Stone are principally capitate forms, that is to say, they spring from a peduncle and divide suddenly. The short and fissiparous species, Zhecos- milia rugosa, is very common amongst the non-capitate forms, and so is the Thecosmilia Michelini, Terq. et Piette. At Brocastle and Cowbridge the larger Zhecosmilie are common, but Thecosmilia _ Michelini forms large masses at Cowbridge, and studs blocks at Laleston. Although the specimens are very numerous, still the individuals rarely attain that bush-like structure which is noticed in the Continental beds. At Cowbridge the specimens are mostly found as casts. 1. Tuxcosmit1a Surronrnsis, Duncan. PI. IV, figs. 7—9. ‘The corallum has a slender and nearly straight peduncle, which gives off corallites from an enlarged summit. The peduncle is moderately marked with transverse ridges and constrictions, and does not taper symmetrically from above downwards. ‘The epitheca is thin, and permits very numerous and fine costz to be seen through it. The corallites springing from the parent (the peduncle) originate by intercalicinal gemmation ; they are separate as regards their walls, and differ in size, being marked with transverse epithecal folds and constrictions. The calices are not quite circular, and their septal arrangement is irregular. The septa are unequal, and one half of them extend nearly to the centre, whilst the smaller pass inwards but for a short distance. The number of septa increases with the growth of the calices. In large calices there are more than four cycles, and in the smaller less than three cycles, or three cycles. The endotheca is highly developed. Height of corallum 1}inch. Diameter of large calice ~ths inch. Diameter of small calice 3ths inch. Locality. The Sutton Stone. In the Collection of Charles Moore, Hsq., F.GS., Bath. This species has some resemblance to Zhecosmilia serialis in its short peduncle and capitate swelling ; but the retention of the circular outline by the calices is distinctive. It has some resemblance in its calice to the simple calice of Thecosmilia rugosa, Laube, but there is no fissiparity observed. The origin of the corallites by intercalicinal gemma- tion is very distinctive, as are also the thin epitheca and the columnar shape of the 12 BRITISH FOSSIL CORALS peduncle. The habit of the species resembles that of the majority of the stunted Thecosmilieé of the period. 2. THECOSMILIA MIRABILIS, Duncan. PI. II, figs. 10, 11. The corallum is short, very finely pedicellate, increasing rapidly in breadth, and terminating by a large upper surface on which are several circular and distinct calices. The trunk of the corallum is smooth, and is slightly marked with rounded transverse swellings, and corresponding constrictions. No coste can be seen. The corallites are unequal in size, separate immediately, do not increase by fissiparity, and are characterised by circular calices having a very sharp margin. ‘The calices are shallow. The septa are numerous, crowded, and very regular; they are alternately long and short, and all are marked with small lateral swellings and faint linear depressions on the upper edge. The largest calices have four cycles of septa, and nearly a complete fifth cycle, the septa numbering from seventy-six to eighty-four. Height of the corallum Zths inch. Breadth of the upper surface ths inch. Dia- meter of the largest calice ths inch. Locality. The Sutton Stone. In the Collection of Rev. H. Winwood, F.G:S., Bath. 3. THECOSMILIA SERIALIS, Duncan. PI. IV, figs. 1O—12. The corallum has a narrow, curved, and rather long peduncle, which gives off several corallites from its summit. The peduncle is strongly marked with lateral ridges and constrictions, and so are the corallites. — The epitheca is stout, and, where worn, permits the cost to be seen. The young corallites arising by fissiparity from the parent, which constitutes the peduncle, separate into some which remain circular in transverse outline, and into others which form short serial calices. The circular calices present four cycles of septa, and the serial have their septa less crowded and larger. ‘The serial calices do not present any evidences of fissiparity. Height of corallum 1;; inch. Diameter of circular calice }th inch. Length of serial calice 2ths inch. Breadth of serial calice th inch. Locality. 'The Sutton Stone, In the Collection of Charles Moore, Esq., F.G.S., Bath. This species belongs to the stunted Zhecosmili@ so characteristic of the ‘Triassic and Liassic coralliferous strata ; it is readily distinguished by the number of corallites spring- ing from the peduncle, and by its long and serial calices being mixed with rounded ones. FROM THE ZONE OF AMMONITES ANGULATUS. 13 The mineralization of the specimen gives the appearance of a columella in the elongated calice, but there is really no such a structure. 4. Turcosmiii1a ruGosa, Laude.’ Pl. I, figs. 1—6. The corallum springs from a small base, divides soon, and the branches are covered with an exceedingly strong epitheca marked with thick folds. The calices, one or more in number, are either nearly round, or are irregularly distorted. They are deep, and the septa are stout, straight, and not very unequal. They number from thirty-four to thirty-six. The diameter of a tolerably regular calice is 4ths inch, and the length of a distorted calice 4ths inch. The height of the corallum is about an inch. Locality. The Sutton Stone. In the Collection of Charles Moore, Esq., F.G.S., Bath. M. Laube’s description of the species from the St. Cassian beds is simple and accurate. His small Zhecosmilia has a strong epitheca, with constrictions and swellings, and its calices are now and then fissiparous. His plate gives the idea of there being more septa ; and this is the only distinction which can be made between the St. Cassian and the British species. 5. Tuxcosmitia Bropini, Duncan. PI. X, figs. 1, 2, 3, 4. The corallum is rather short; the corallites are cylindrical and large in relation to their height, and they appear to divide near together, so that regular calices are rare. The epitheca is stout and complete, being marked with slight constrictions. The calicular margin is sharp, and the calices are deep. The septa are numerous, and the large primary and secondary septa are equal and very dentate. The tertiary septa are very much smaller than the secondary, are not dentate, but are long; and the septa of the fourth and fifth orders are very small. Diameter of the calices 4ths inch. Locality. Brocastle. In the Collection of Charles Moore, Hsq., F.G.S., Bath. The extraordinary development of the dentate first and second cycles of septa characterise the species. ! Laube, ‘ Die Fauna der Schichten von St. Cassian,’ 1 Abtheil. 14 BRITISH FOSSIL CORALS 6. Tuecosmitia Martini; &. de From.’ Pl. X, figs. 6—9. The corallum is bush-shaped, and is formed by dichotomous cylindrical corallites, which are covered with a strong folded and complete epitheca. The corallites separate rapidly, and remain free for some distance before fissiparous growth occurs again. The dissepiments are very developed, and are inclined. The calices are circular, or slightly oval. The septa are very thin and distant. There are thirty-two large septa, one half of which reach the centre, and there are forty-eight small, or rudimentary septa. The calices are about 2ths inch in diameter. Localities. Brocastle, Ewenny, Cowbridge. In the Collection of Charles Moore, Esq., F.G.S., Bath. This species is distinguished by its size, high septal number, and highly developed endotheca. In the British specimens the septa are stouter, and the calices are often larger than in the French ; moreover the larger septa are often raised to the number of forty-eight. The rudimentary septa are not shown in M. Martin’s plate. ‘The localities whence the species has been derived have been the middle and upper beds of the Zone of Ammonites Moreanus, at Semur, and Vic de Chassenay Cote d’Or. It is found in the limestone of Charleville, with Ammonites bisulcatus, in the sand- stone containing Ammonites bisulcatus, at Saul, and in the Hettangian sandstone con- taining Ammonites angulatus. 'The species had thus a considerable range both in space and time ; and it followed the usual habit of widely wanderimg species, in varying from the true specific type. 7. Tuecosmiuia Micueuini, Zerg. e¢ Piette.” Pl. VII, figs. 10—13; and Pl. X, figs. 10—14. The corallum is bush-shaped, and is formed by numerous, close, dichotomous, sub- cylindrical, long and slender corallites, which are surrounded with a thick, folded, smooth, complete, and persistent epitheca. The calices are nearly on the same level, are rounded or oval, and the fossa is not very deep. The septa are forty in number, and are alternately large and small. The endothecal dissepiments are very close. ' Martin, ‘ Pal. Strat. de l'Infra-Lias,’ 1860, pl. viii, figs. 8, 9. * ‘Le Lias Inférieur de l’est de la France,’ p. 127, pl. xvii, figs. 7, 8. FROM THE ZONE OF AMMONITES ANGULATUS. 15 The height of the corallum may reach 6 inches. Diameter of a corallite ird inch. Localities. Brocastle, Cowbridge, Laleston, the Sutton Stone, and Ewenny. In the Collection of Charles Moore, Esq., F.G.S., Bath. MM. Terquem et Piette (‘Le Lias Inférieur de l’est de la France,’ p. 127, PI. xvii, figs. 7, 8) have described this well-marked species in their usually concise manner. The smaller size of the corallites, the septal number, and the small amount of endotheca, dis- tinguish the species, which is very common in the Glamorganshire beds. The bush shape of the corallum may be imagined from the grouping of the casts of the species in the limestone at Cowbridge; and the dichotomous and slender form of the corallum is common at Laleston and in the Sutton Stone. The rounded swellings and intermediate constrictions of the plain epitheca are very characteristic. The French specimens are derived from the beds at Aiglemont, in the zone of Ammonites angulatus. 8. THECOSMILIA IRREGULARIS, Duncan. PI. III, figs. 1—6 ; and Pl. X, fig. 5. The corallum is small, short, and has a broad base. It consists of a short and rather cylindrical peduncle with a broad base, a very strongly marked and ridged epitheca, and of an upper part whence the calices spring by fissiparity. The calicular surface is considerably broader than the peduncle, and overhangs. The calices are small, shallow, irregular in shape, and have a distinct margin. The septa are few in number, large, unequal, and very irregular in their arrangement. They have large rounded teeth upon their upper margins, and the larger septa occa- sionally unite by their inner margins, which are toothed. There are about twenty septa, and several others which are rudimentary. There are no coste. Height of corallum 3ths inch. Diameter of calices 2ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. THECOSMILIA IRREGULARIS, Duncan. (A variety.) PI. III, figs. 14, 15. The calices are deeper, the septa longer and more slender, and the dentations sharper and more distinct than in the type. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 16 BRITISH FOSSIL CORALS 9. Tuecosmitia TEravEemI, Duncan. PI. II, figs. 7—12. The corallum has a fine pedicle, which increases in breadth very rapidly, and produces a large upper surface, upon which are the calices, or one corallite may spring from the edge of the upper surface, and give rise to others in the same manner. (Plate X, fig. 4.) The epitheca is strong, folded, and constricted ; where worn, the costz and exothecal dissepiments appear. The calices are irregular in shape, size, and distance. The septa are unequal in size and are bluntly dentate, their arrangement is irregular, and a quaternary disposition of the lamine is very evident, and they may number sixteen, twenty, or thirty-two. ‘The larger septa do not indicate an hexameral arrangement. All are thick, distant, and pointed internally. Height of the corallum ths inch. Diameter of the calices 3ths —3ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 10. Tuecosmitia arrinis, Duncan. PI. III, figs. 18—20. The corallum is short, and the corallites separate soon after leaving a short, conical peduncle. The calices are deep and open. The septa are irregular, unequal, distant, often curved, dentate at their inner margin, and about sixteen in number. The epitheca is moderately strong. The height of the corallum is {ths inch. The diameter of the calices is 4ths inch. 10 Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 11. Tuecosminia DENTATA, Duncan. PI. III, figs. 21—28. The corallum has a broad base, and the corallites separate soon, and diverge; they are subcylindrical, and their epitheca is smooth. The calices have a very distinct margin; they are slightly deformed, not very deep, and contain numerous septa. The septa are unequal ; alternately large and small, irregular, and present distinct and numerous blunt dentations. The smallest septa are simple dentations, and the different sizes of the septa and dentations are very remarkable. There is no exact arrangement of the septa in cycles, and their number varies from thirty to thirty-two and thirty-six. FROM THE ZONE OF AMMONITES ANGULATUS. 17 Height of corallum ths inch; breadth of calice {ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 12. Tuucosmitia PLANA, Duncan. Plate ITI, figs. 24, 25. The corallum is short, the calices separate rapidly, and soon attain a considerable size. The epitheca is strong, and constricted here and there. The calices are large, shallow, oval, and are deeper at the centre than elsewhere . their margin is indistinct, and the septa are rounded, faintly dentate, distant, and*very irregular. There are about thirty septa. Height of corallum ths inch ; breadth of calice ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. These species of the genus Thecosmilia may be arranged for the purposes of diagnosis as— Th. Martini. Th. Michelini. EB Suttonensis. Long and more or less bush-shaped Th. mirabilis. Th. Terquemi. Th. serialis. Pedunculate and capitate ( Th. irregularis. Th. rugosa. Short and stunted ; ’ : : ov Ree Lg i | Th. dentata. | Th. affinis. Taken as a series, the species are very characteristic of the Coral-fauna of the period. Genus—RUHABDOPHYLLIA. 1. Ruaspopnyiiia ReconpiTa, Laude.’ Plate II, figs. 7—9. The corallum is pedunculated, has very fine costal markings, which are flat, and a delicate epitheca. The corallites separate rapidly at the extremity of the peduncle. The calice (section of) is almost circular, and is crowded with rather stout septa. The septa are unequal, longer at the calicular margin than elsewhere, and either reach the columella or enlarge at their free extremity at different distances from it. 1 Laube, ‘Die Fauna der Schichten von St. Cassian,’ 1 Abtheil. 18 BRITISH FOSSIL CORALS There are four cycles of septa in six systems. ‘The primary reach the columella. The tertiary, which are longer than those of the higher orders, join the secondary septa. The columella is well defined, and is circular in its transverse outline. The diameter of the corallite is about +} inch. The specimens are usually covered with parasitic corals or sponges. Locality. The Sutton Stone. The St. Cassian beds. In the Museum of Practical Geology, London. Laube’s' description of this species is very faithful, and it is readily recognised by the curious septal arrangement. The specimens are rare in the Sutton Stone, and the sections showing the septa require very careful examination before they can be understood. . Famity—ASTRASACEA. Genus—ASTROCENIA. 1. Astrocenia GIBBosa, Duncan. Pl. V, figs. 2, 3, 4, 12; Pl. IV, fig. 3; Pl. VI, figs. 1, 2, 3, 4. The corallum is large, and covered with rounded eminences of various sizes. ‘The calices are large, polygonal, close, irregularly placed, irregular in size, and shallow. The septa are usually twenty in number, are jomed to small narrow club-shaped straight cost, are very unequal in size, and usually one half of them reach to the columella. ‘The smaller and shorter septa unite in many instances to the larger septum between them, but not very close to the columella. ‘The septa are finely dentate laterally, and there is a trace in some of the longest of a swelling close to the columella. Their development is very irregular. The columella is moderately prominent and large. The ccenenchyma is not strongly developed, but in sections the presence of orna- mentation in the form of round processes is observable. The endotheca is occasionally noticed in the calicular fossa, and extends from septum to septum. ‘ Three large calices, with their coonenchyma, occupy the length of nearly ;ths inch. Locality. The Sutton Stone, and Brocastle. In the Museum of Practical Geology, London ; and in the Collections of Charles Moore, Esq., F.G.S., and Rev. W. Winwood, F.G.S., Bath. 1 Laube, op. cit. FROM THE ZONE OF AMMONITES ANGULATUS. 19 2. ASTROCENIA PLANA, Duncan. PI. V, fig. 1. The corallum is large, flat, and short. The calices are small, very regular in their linear arrangement, polygonal, and nearly equal: they are rather deep and rather distant. The septa appear to be from eight to ten in number, and reach the columella. The costz are very indistinct. The columella is large. The ccenenchyma is well developed, and becomes divided into rounded eminences between the calices ; and where four of these are together, the intervening ccenenchyma is decidedly peaked. Three of the largest calices, with the intervening ccenenchyma, cover a length of “ths inch. Locality. The Sutton Stone. In the Museum of Practical Geology, London. 3. ASTROC@NIA INSIGNIS, Duncan. Plate IX, figs. 1 and 2. The corallum is large ; it is flat on the upper surface, and is short. The calices are somewhat regular in their linear arrangement; they are unequal, and are irregular as regards their outline and distance. They are shallow, and are large in comparison with those of most of the species of the genus. The septa are large, and nearly equal in size at the calicular margin, but all do not reach the columella. Generally five primary septa extend to the columella, and there are three which only reach a little way into the calicular fosse between the longer pri- mary. ‘The central of these smaller septa is often longer than those on each side of it. The septal number is irregular, but twenty is the usual number. In some calices the shorter septa are decidedly smaller than the others. The costz are large, broad, straight, nearly equal, club-shaped, close, and are oblique in some, but flat in other calices. They extend over the ccenenchyma when it exists, do not coalesce with those of other calices, and are often separated by a ridge. Neither septa nor costz appear to be spined or dentate, but a very slight unevenness of the margin may be noticed in well-preserved specimens. The columella is small, sharp, and prominent. The size of the calices varies, and in large specimens, where there is some coenenchyma, three calices and their ccenenchyma occupy rather more than {ths inch. ‘The smailest calices, with a small quantity of coenenchyma, do not occupy one half of that space. Locality —Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 20 BRITISH FOSSIL CORALS .. ASTROCHNIA REPTANS, Duncan. Plate IV, figs. 4, 5, 6, 15. ‘The corallum is short, convex, and very irregular; it is moderately large for an Astroccenian, and is covered with numerous and closely packed calices. The calices are polygonal and shallow, and are separated by very distinct, plain, coenenchyma, which is obtusely ridged, and prominent here and there. The septa are twenty in number; ten reaching the columella, and ten joining five of the longer, in pairs. ‘The septal arrangement is very marked. The columella is small and the coste are rudimentary. ‘The length of three calices, with the coenenchyma, is about 3ths inch. — Locality. The Sutton Stone, Brocastle, and at Ewenny. In the Collection of Charles Moore, Esq., F.G.S., Bath. 5. Astroc@nia parasitica, Duncan. Plate V, figs. 5, 6. ‘he corallum encrusts other Madreporaria, such as dendroid Astraeacez or ‘“‘ remanié ” Lithostrotions ; it is small and short, and possesses much ccenenchyma. The calices are very small, distant, and shallow. The septa appear to be ten in number. The columella is well marked. The ccenenchyma is plain. The diameter of the calices is about ith inch. Locality. The Sutton Stone. In the Museum of Practical Geology, London. . 6. AsTRoc@NIA PEDUNCULATA, Duncan. Plate V, figs. 7, 8, 9. The corallum is small, pedunculate, and fungiform; it has an epitheca and much coenenchyma. . The peduncle is short, small, and rounded, and joins the expanded discoid epithecate hase of the true corallum near its centre. ‘The discoid base has an epitheca, and its edges are slightly rounded. The convex upper part of the corallum is covered with unequal, shallow, and distant calices. The calices are irregular in size, and are small. The septa are small, alternately long and short, and are granulated laterally. There are twenty of them, and the smallest are rudimentary. FROM THE ZONE OF AMMONITES ANGULATUS. 21 The ccenenchyma is abundant, and is elevated between some calices and flat between others. Height of the corallum ths inch. Locality.—Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 7. AsTRocenta costaTa, Duncan. PI. IX, figs. 15, 16, 17. The corallum is small, irregular in shape, and rounded above. The calices are numerous, and rather deep; they are either very close together, or they are separated by more or less coenenchyma, whose upper surface is marked by wavy costze. The septa are usually twenty in number, and their costal ends are nearly equal. The cost are either very small, small and curved, or large and more or less curved as they approach the cost of neighbouring corallites. The columella is small. The space occupied by three large calices, separated by much ccenenchyma, is ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 8. AsTRoc@NIA FAVOIDEA, Duncan. PI. IX, figs. 12, 18, 14. ASTREHA FAVOIDES? Quenstedt, Der Jura, 1858. The corallum is more or less globose, and the calices are very small, very deep, and are separated by sharp ridges. The coenenchyma is rudimentary. The septa are twenty in number, the smaller being very rudimentary. The costze are rudimentary. The columella is small, and is situated at the base of the very deep calice. Localities. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. Also in the Arieten-Kalk of Germany. , 9, Asrroca@mnia supERBA, Duncan. PI. IX, figs. 3, 4, 5. The corallum is small, and irregular in shape. The calices are shallow, wide apart, and usually circular in outline. The septa are usually {twenty in number, are small near the columella, and thicker at the costal end. About one half of them reach the columella. They are dentate. 22 BRITISH FOSSIL CORALS The costz are highly developed, and cover the ccenenchyma, which is also spiny between the costal ends. Nearly all the costz are equal ; they are straight in some. places and wavy in others, but all are strongly dentate and well marked. The columella is small. Three calices occupy about } inch in length. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 10. AstTROC@NIA DENDROIDEA, Duncan. PI. IX, figs. 9, 10. The corallum is in small branches, with blunt extremities. The coenenchyma is highly developed and plain. The calices are wide apart in some places, but close in others ; they are shallow, small, and more or less circular. The septa are very irregular in their number, and their costal ends are club-shaped and rounded. The columella is small. The branches rarely exceed } inch in length. Locality. Brocastle, and at Ewenny. In the Collection of Charles Moore, Esq., F.G.S., Bath. Ul. Astroca@nia minuta, Duncan. PI. IX, figs. 16, 19, 20. The corallum is large, flat, and thin. It is more or less encrusting in its habit. The calices are very small, rather deep and close: they are more or less circular in outline, and are separated by a small quantity of coenenchyma. The septa are usually twenty in number, and many of them have a paliform tooth close to the columella. The costz are small. The columella is small. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 12. Astroca@nia Stnemuriensis, D’Oré., sp.’ The corallum is in the shape of a rounded mass, which is formed of superimposed layers. The calices are small, and tolerably regularly polygonal. The columella is stout, and projects. The septa are rather thick, unequal, and slightly close. There are twenty ' Martin, op. cit., pl. vii, figs. 26, 27. FROM THE ZONE OF AMMONITES ANGULATUS. 23 in each calice, ten large and ten small. The internal ends of the large septa are rounded and swollen out. Diameter of the calices 1! inch. M. D’Orbigny considered the swollen ends of the principal septa to be pali, and placed the species in the genus Stephanocenia, but M. de Fromentel determined the correct position of the form to be amongst the ‘“ decemeral’ Astrocceniz.’ | The species does not appear to have been formed from very perfect specimens, and in M. J. Martin’s admirable plate the septa are all equal in length and thickness, and the calices are close together. It is impossible to determine from either the description or the plate whether the calices are deep, whether there is any ornamentation, or whether the coenenchyma is marked in anyway. There are many species of Astroccenia which are massive, and their formation from superimposed layers is the result more of a process of mineralization than of growth. The form is readily recognisable in its strata, because it is rare and as yet the only species discovered ; but placed in comparison with others from distant localities it is hardly to be distinguished, on account of its defective specific distinctive peculiarities. The Astrocceniz of the Sutton Stone, and from Brocastle, show the smaller septa joining the larger more or less, but this does not appear to be the case in 4. Sinemuriensis. The enlarged state of the septal ends is common to several Astroceeniz. It is very probable that with more complete specimens, the occasional union of the septa will be observed in 4. Sinemuriensis, for in some specimens of most of the species this non-union is seen in certain calices. Specimens of some Astrocceniz in the Sutton Stone and Brocastle beds put on all the appearances of this species when worn. It is therefore introduced here; but not figured.’ The genus Astrocenia was formerly included in the Lusmiline aggregate, but Reuss* pointed out the fact that the upper margins of the septa of the species falling under his observation were dentate and not smooth. M. de Fromentel* discovered in the Neocomian formation some species which had dentate septa; and after acknowledging Reuss’s discovery, he placed the genus amongst the XX Vth family of his classification, the “ Astréens.” This family corresponds in part to the Astreacee of Milne-Edwards and J. Haime, and the genus may be considered to form a part of the Astreacee. In the Introduction to the British Fossil Corals,’ Astrocenia, being placed amongst the Husmiline, follows the genus Stylocenia, and was evidently considered to be closely allied toit. The following i is the generic diagnosis by MM. Milne-Edwards and J. Haime: 1 Pal. Strat. de Infra-lias, p. 94. J. Martin, 1860. 2 See “Remarks on Astrocenia Sinemuriensis and Astrocenia Oppeli,” Laube, in my essay on the “« Madreporaria of the Infra-Lias of South Wales,” ‘ Quart. Journ. Geol. Soc.,’ Feb. 1867, ». 25 (note). 3 Reuss. ‘ Beitrage, zur Charakteristik der Kriedeschichten.’ 4 E. de Fromentel, ‘ Introd. a l'Etude des Polyp. Foss.’ 5 «Introd. to Brit. Foss. Corals: Paleeontogr. Soc.’ 24 BRITISH FOSSIL CORALS 7 ‘“Corallum very dense, and not bearing columnar processes, as in the preceding genus. Calices polygonal, columella styliform, not projecting much. No pali. Septa thick, apparently eight or ten systems, two or four of the secondary septa being as much developed as the six primary ones. Walls thick and united as in Stylocenia.” M. de Fromentel separated the genera Astrocenia and Stylocenia, and retained the latter amongst the Husmiline aggregate. There was no reference made, therefore, in his generic diagnosis of Astrocenia to the genus Stylocenia. M. de Fromentel’s descrip- tion of the generic peculiarities of Astrocenia are as follows: ‘“ Corallum massive, com- posed of corallites united by their walls, which are prismatic in shape ; the calices are polygonal ; the columella is styliform, and more or less projecting ; the septa are tolerably thick, are few in number, and are dentate, especially near the columella ; there are no pali.” Whilst investigating the Madreporaria of the Maltese rocks in.1865, I found that the septa of the common species Stylocenia lobato-rotundata, Mich. sp., were dentate.’ The species occurs also in the Chert of Antigua, and presents there the usual plain septa considered to mark the family of the genus. If fossilization can remove the dentations of the septa of one Stylocenian, it can do so in others, and it may be safely asserted that all the Stylocenians had dentate septa. This dentate condition of the septa brings the genera Astrocenia and Stylocenia together again, although it removes them from the Zusmiline into the Astreacee. MM. Milne-Edwards and J. Haime’s generic description can thus stand, and its concluding sentence respecting the thick walls of the genus which was omitted by M. de Fromentel is very important. In some species, as in 4. pulchella, Ed. & H., the calices are so wide apart in some © specimens, and in certain spots in all the specimens, that there is evidently here and there a ceenenchyma between the walls of the corallites. The surface of the ceenenchyma, which appears to arise from an hypertrophied condition of the adjacent corallite walls, is - usually ornamented either with prolongations of the coste, or with small papillose granules. This is observed in other species, and it is noticed that the amount of ccoenenchyma varies according to the shape of the corallum, and the rapidity of the multiplication of the corallites. ‘The presence of scattered granules, or of small papillae on the ccenenchymal surface, and between the external terminations of the costa, is observed in some speci- mens of a species, and not in others; but the coste, although they may extend far over the inter-calicular spaces (or, in other words, over the surface of the ccenenchyma), never unite, and run into those of adjoining corallites. There are modifications in the length and straightness of the costae, and where there is no ccenenchyma, and the walls of the corallites are thin, they may be so reduced in size as to appear to be simple terminations of septa. In many species the ccenenchyma, when non-costulated, and not ornamented with granules, becomes slightly ridged, and foreshadows the condition which peculiarises the genus Stylocenia. ' «Ann, Mag. Nat. Hist., April, 1865. ~*~ FROM THE ZONE OF AMMONITES ANGULATUS. 25 ‘ne reproduction by gemmation cannot occur from the walls of the corallites, except at the edge of the corallum. The close contact of the walls, and the existence of dense ccenenchyma, prevent any budding from the wall; but where the outside corallites are partly free, there gemmation may occur outside and below the calicular margin. Fissiparity does not occur, but the young buds arise either from the top of the calicular edge or margin, or just within the calice. When there is some distance between the calices on account of the thickened walls or ccenenchyma, buds may arise on the ccenen- chymal or inter-calicular surface. Many of the species have an epitheca, some are pedunculated, and others are massive, encrusting, or dendroid. The septa vary greatly in their numbers and cyclical arrangement, and very often they have a large paliform tooth close to the columella. There are no pali. A styloid columella projecting more or less, is an essential generic requisite. The endotheca is scanty, but it always exists. The calices are small, and vary in depth; but, as a rule, they are arranged with great symmetry, and are polygonal in outline. ‘Transverse sections show the complete consoli- dation of the walls, and the space between the costal ends, in these sections, is often marked with granules. The species without any coenenchyma, and whose walls are thin, are distant in their alliance to Stylocenia, and had they no columella, they would be considered to belong to the genus Jsastrea. The genus Cyathocenia (Duncan) comprehends Astrocenie without columellee. The fossil condition of the specimens must be considered during the specific deter- mination of Astrocenie. Usually, the columella is represented by a flat, central, and more or less circular mass with the ends of thick septa adherent to it. In these in- stances a calcareous deposition has occurred around the columella and between the septal ends, the columella having been broken off. It happens, however, that the columella may be broken off without the deposition having taken place, and either the structure retains its normal size at the point of fracture, or is absent altogether. On examining doubtful specimens which have lost their columella, much attention should be paid to longitudinal sections produced by weathering, fracture, or by artificial means. A small projection at the base of the calice is more readily determined to exist in longitudinal views than in those which simply show the open calice. There are eleven species of the genus Astrocenia special to the Welsh Lias, and one species found with these has been described by D’Orbigny as Stephanocenia Sinemuriensis. M. D’Orbigny obtained his specimens from the Lower Liassic deposits of France. M. de Fromentel and MM. Terquem and Piette have found the species in several localities, and the first-named palontologist has determined it to belong to the genus Astrocenia. The Liassic Astroceni@ occur as large and massive, small and dendroid, or as irregu- 4 26 BRITISH FOSSIL CORALS lar and sometimes as encrusting forms. All are very irregular in their septal arrange- ment, and none of them present definite and clear cyclical sequences. Some of the species have the ccenenchyma between the calices regularly ridged, so as to present the first traces of that ccenenchymal development which characterises the eenus Stylocenia. The columella is very distinct in all the species, and the junction of the largest septa to it is marked in some forms by a paliform swelling, but there are no pali. In many species the smaller septa unite more or less to the larger, and in others the dentate condition of the septal edge is very marked. The costae are either rudi- mentary or well developed in different species; they may be straight, spimed, and wavy. ‘The size of the corallum, its shape and its habit, with the size of the calices, and the character of the costee and of the ccenenchyma, appear to separate certain forms from others and enable eleven new species to be classified with the Astrocenia. The following scheme of the structural peculiarities of the new Astrocenie will show how readily their specific distinctions may be recognized : ASTROCCENIA. gibbous and tall. F . Astrocenia gibbosa. (large ee and short . ; : : { rn ania — insignis. | short, and irregular in outline . — reptans. Corallum , } encrusting . . : . — = parasitica. | pedunculate, with an epitheca . — pedunculata. | dendroid - : F F — dendroidea. small flat and narrow. ‘ 4 — superba. globose . : ‘ ‘ ; — favoidea. irregular : , ¢ f — costata. flat and semi-encrusting . : — minuta. Astrocenia favoidea. sin i : i — minuta. — parasitica. | | —_ dendroidea. Corallum having the coeneuchyma ./ abundant . 4 ° — superba, — pedunculata. ( — insignis. — reptans. ‘moderately developed ; | orci ty La | — gibbosa. — plana. FROM THE ZONE OF AMMONITES ANGULATUS. 27 and straight . -Astroceenia insignis. spined : — superba. coste well ornamented . developed wavy ; ae costata. — = gibbosa. — — gibbosa. The surface of the — plana. ccenenchyma ridged . . : : 5 ; : — minuta. = reptans. — dendroidea. ; — parasitica. plain | P — pedunculata. rudimentary. é : : : : : — favoidea. Genus nov.—CYATHOCENIA. This genus has been determined for species which, had they columella, would belong to the genus Astrocenia. _ The walls of the corallites of the species are joined, and there is more or less ccenen- chyma. ‘The costz are not confluent, and the septa are finely dentate. There are no pali, nor is there acolumella. There is no fissiparity, and the gemmation is either from the intercalicular surface, or from the calicular margins. There is always some ccenenchyma present, and this distinguishes the new genus from Isastrea, the only genus with which it can be confounded. The following is the generic formula : Cyathocenia.—The corallum is compound. The corallites are united by their wails and by more or less coenenchyma; they are more or less polygonal, but are often cylin- /drical. The calices are small, the costa are not confluent, and the septa are finely dentate. There is no columella. There are no structures on the coenenchyma between the calices except granules and coste. ‘The gemmation is superior and marginal. 1. CYATHOCENIA DENDROIDEA, Duncan. Plate IX, figs. 6, 7, 8, 9. The corallum is large and tall, forming fasciculate masses. ‘The corallites are more or less crowded on the surface of stems, which branch rarely, and which are close and more or less parallel. The transverse outline of the stems is irregular, from variability in their thickness, and also from the presence of superficial calices. The stems consist of calices separated by coenenchyma whose amount varies. The calices are distant when there is much coenenchyma, but occasionally they are close, and their margin then becomes round; they are small, are irregularly placed, and are rather deep. 28 BRITISH FOSSIL CORALS The septa are dentate, distinct, distant, unequal, stout, not exsert, and pass obliquely downwards and inwards,-so that they do not encroach much upon the calicular fossa. There are eighteen in some and twenty-four in the largest calices. Three cycles appear to be the normal number. ‘There is no columella. The coste either reach on to the surface of the ccenenchyma or end abruptly at the calicular margins, and they never become continuous with those of other calices. The stems are several inches in height, and are from 3ths to ths of an inch in diameter. The calices rarely exceed 3th of an inch in diameter. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S. The peculiar mineralization of the specimen prevents the structure of the central parts of the stems being distinguished. There is a dendroid Astroccenian in the Brocastle beds which has some resemblance to this species, but the well-developed columella of the first distinguishes it at once. MM. Terquem and Piette have described a species MMicrosolena Fromenteli, whose bush-like form and_ parallel constricted and irregular stems resemble Cyathocenia dendroidea, but the calices have a columella, and the costae are continuous ; nevertheless, the “habit” of both species is very similar. 2. CyaTHoca@nia INcRuSTANS, Duncan. PI. IV, figs. 1, 2. The corallum is very thin and encrusts portions of the shells of Bivalve Mollusca. The calices are unequal, circular or subpolygonal, rather close and very shallow. The septa are few in number, are very small, and are marked with distinct and almost monili- form processes. ‘They are thickest at the margin of the calices. The larger septa usually alternate with smaller, but, as a rule, the largest are the most numerous. The septa cannot be recognized as following a cyclical arrangement, and they vary in number from fifteen to twenty. There is no columella. The ccenenchyma is scanty and is marked with large granules, which are the representatives of coste. The gemmation occurs between the calices. Diameter of calices 4th to 3th of an inch. Locality. The Sutton Stone, encrusting an Osérea. In the Collection of Charles Moore, Esq., F.G.S. The papillate septa and encrusting habit distinguish the species from C. dendroidea, and C. costata. 1 Op. cit., pl. xvii, figs. 11, 12. FROM THE ZONE OF AMMONITES ANGULATUS. 29 3. CyatHocenta costata, Duncan. PI. V, figs. 10, 11. The corallum is flat, and presents slightly rounded eminences ; it is short, and has an irregular base where it is attached to foreign bodies. The calices are numerous, nearly equal, and distant. The margins of the calices are flat, and are continuous externally with the coenenchyma, whose upper surface is covered by the coste. The calicular fossz are deep. The septa are small, unequal as regards length, but rather equal in their thickness ; they vary in number from twenty to twenty-four. There is no columella. The costz are large, slightly rounded, not continuous, and occasionally slightly wavy. Three calices occupy a length of ;ths inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. Genus—ELYSASTREA.! 1. Exysastr#A Fiscueri, Laube2 Pi. VI, figs. 5—9. The corailum is massive; the corallites are close and united above and near the calices, but separate and more or less covered with epitheca below. The corallites are unequal in size, tall, and more or less cylindrical below and polygonal above. The calices are very variable in shape and size, and the margin is broad and distinct. The septa are numerous, often wavy, unequal in length, and near to the centre of the calice a new set appears to come in, in some calices. There are no pall. The number of septa depends upon the size of the calice, and it may vary from forty to sixty. The septal lamine are thin, and faint traces of costa may be seen where the walls are not fused together. The gemmation is extra-calicular, but the bud probably springs from the centre of a corallite, and works its way outwards. The columella is rudimentary. Diameter of calices, ths to jths inch. Locality. The Sutton Stone. The St. Cassian beds. In the Museum of Practical Geology, London. 1 Laube, op. cit., and ‘Intro. Brit. Foss. Corals,’ 2nd series, part i. 2 Laube, op. cit. 30 BRITISH FOSSIL CORALS 2. Enysastr£4 Moores, Duncan. Pi. VI, figs. 1O—15. The corallum is massive, and the upper surface is very irregular. The corallites are joined by their walls in many places, but are free in others, both superiorly and lower down in the corallum. The corallites vary greatly in size, and the smallest are usually jomed by their walls, and are more or less angular in outline. The largest corallites are circular in outline. The calices are irregular in their depth, and are either circular or polygonal. They are close, even when not adherent. The septa are alternately large and small, are faintly dentate, and are very variable.in number. ‘There are forty-eight septa in the largest calices. ‘The costae are continuous with the septa in the separate corallites, but do not exist when the walls are united. The columella is deficient. The endotheca is very abundant. The diameter of the calices is from iths—ths inch. Locality. The Sutton Stone, and at Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. The genus H/ysastrea is very remarkable ; it has affinities with Jsastrea and with the very close bush-shaped Thecosmilie. The bush-shaped Thecosmilie are noticed to become united by their walls in some specimens, and the walls of Sepfastree and Prioastr@e ave occasionally not united inferiorly. The species Hlysastrea Moorei has its corallites more distinctly separate than the St. Cassian form, which is, however, clearly represented in the Sutton Stone. The appearance of septa near the centre of the calice is very characteristic of the genus. Genus—ISASTRAA. |. Isastrma Stnemuriensts, Z. de Fromentel.' Pl. VII, figs. 1—9. The calices are polygonal, and tolerably deep. The septa are very numerous, spined, close, and unite occasionally by their inner ! Martin, ‘ Pal. Strat. de l’Infra-Lias du dep. de la Céte d’Or,’ 1860, pl. vii, figs. 16, 17. FROM THE ZONE OF AMMONITES ANGULATUS. 31 border. ‘There are seventy-eight septa in the largest calices, and they are unequal. The calices are from 3ths—ths inch in diameter. To this specific determination of M. de Fromentel the following may be added, as better specimens have been derived from the Brocastle bed than elsewhere. The corallum is massive, and irregular in shape, but often assumes a subglobular form. When this is the case there is an epitheca, which is strongly folded, but which is lost as the calices are developed. The size of the calices is very irregular, and marginal gemmation is very common. The septa are crowded and distinct, and in the largest calices there are many of the fifth cycle, but there is great irregularity in the septal number. ‘The septa are often not quite straight, and present swellings at several points. Locality. Brocastle. Menetreux, near Samur. In the Collection of Charles Moore, Esq., F.G.S., Bath. 2. IsastR#A GLOBOSA, Duncan. PI. VIII, figs. 17, 18. The corallum is nearly spherical in shape; it has a cylindrical but short peduncle, covered with epitheca, and a rounded upper surface marked with very numerous and closely placed small calices. The calices are shallow, faintly polygonal, and crowded with septa. The septa are unequal, not very thin, and have now and then an enlargement at the inner end. ‘The smaller septa frequently unite to the larger. All are very distinct. A cyclical urangement of the septa cannot be distinguished, and the septal number varies from twenty, twenty-four, to thirty-six. There is no columella. , The diameter of the calices is about {th inch. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. The largest specimens of this fossil are usually much worn, and some care must be taken in examining the perfect calices, for their mineralization often suggests a columella. 32 BRITISH FOSSIL CORALS Genus—LATIMZANDRA. LATIMEANDRA DENTICULATA, Duncan. One or two calices of a Latimeandra occur in several of the hand-specimens in the Collection of Charles Moore, Esq., F.G.S. The calices are long and are straight ; they are separated by sharp walls, and the larger septa have a high paliform tooth close to their inner end. ‘This structure of the septa distinguishes the species; but as no very satisfactory views can be obtained of a series of calices in the specimens, it has not been thought worth while to have the incomplete structures drawn. Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. Division—FAviacEa. Genus—SEPTASTREA. SEPTASTRHA EXCAVATA, &. de Fromeniel.’ Pl. I, figs. 6, 7. The corallum is rather tall and rounded. The corallites are intimately united by their walls, which, although very thin, have a slight line of separation between them. The calices are polygonal, irregular, and deep. The septa are thin, distant, and strongly dentate, especially near the centre. Fissiparity occurs, and the longest calices may have three calicinal centres. In simple calices there are from thirty-six to forty-two septa, which are unequal. The hexameral type is very distinct. The diameter of simple calices is from ths to 3ths inch. In the specimens from Brocastle the abrupt rise of the septa near the calicular margin is very well seen. The calices are very irregular, and the longitudinal sections show constrictions and irregular swellings, which are very characteristic. Most of the calices have forty-eight septa or more, especially those about to divide. Locality. Brocastle; and Pont d’Aisy, Cote d’Or. In the Collection of Charles Moore, Esq., F.G.S., Bath. 1 Martin, op. cit., pl. viii, figs. 1—5. FROM THE ZONE OF AMMONITES ANGULATUS. 33 The remarkable Zhecosmilia rugosa, Rhabdophyllia recondita, and Elysastrea Fischeri, from the lower part of the Sutton Stone, have been described and drawn by Laube from the St. Cassian beds of the Trias. The fauna with which they are associated in the ‘Trias has not been described; but the presence of the species in the Angulatus-Zone of the Lower Lias or the Infra-Lias is very interesting. Thé species described by Terquem and Piette, E. de Fromentel, and D’Orbigny, viz.— Isastrea Sinemuriensis, KH. de From., Septastrea excavata, Ki. de From., Montlivaltia polymorpha, Terquem et Piette, Astrocenia Sinemuriensis, D’Orb., sp., Thecosmilia Martini, EK. de From., A, Michelini, Terquem et Piette, are associated in the Continental Liassic strata with many of the species of Mollusca which are noticed in the Sutton Stone and in the deposits at Brocastle in Glamorganshire. In the Zwmachello of the upper series of the Infra-Lias of Normandy! (the Calcaire de Valogne) Septastrea excavata is found to be associated with the following species, found also with it in the Glamorganshire Lias, which rests on Carboniferous Limestone: Cerithium acuticostatum, Terquem. Turritella Dunkeri, Terquem. Pe Zenkeni, Dunker, sp. Phasianella Morencyana, Piette. Ostrea anomala, Terquem. Cardinia regularis, 'Terquem. At Vic de Chassenay * Zhecosmilia Martini, EH. de From., and Astrocenia Sinemuriensis, D’Orb., sp., are associated with— Ammonites Moreanus, D’Orb. Littorina clathrata, Desh. Cerithium Semele, D’Orb. os gratum, Terquem. 3 acuticostatum, Terquem. The middle bed of the Grés calcareux described by Terquem (‘ Pal. de Hettange,’ 1 Deslongchamps, ‘Mem. Soc. Linnéenne de Normandie,’ vol. xiv, 1864. ? Martin, ‘Pal. Strat. de l’Infra-Lias,’ &c., 1860. Or 34 BRITISH FOSSIL CORALS 1855), contains Zsastrea Sinemuriensis and the following species, in addition to the Mollusca just mentioned from the Céte d’Or and the Calcaire de Valogne : Neritopsis exigua, Terquem. Gervillia acuminata, Terquem. Lima tuberculata, Terquem. Plicatula intusstriata, Emm. Ostrea irregularis, Minst. These species, common in the French beds which are included in the Zone of Ammonites angulatus, and which form part of the Lower Lias of some and of the Infra-Lias of other geologists, are those that are associated with the great Coral-fauna of the Sutton Stone and of the equivalent deposits at Brocastle, in Glamorganshire. The following Table shows the community of some well-known species in the coralliferous Liassic beds of Glamorganshire, and those of France and the Duchy of Luxembourg. — 2 és, ‘S 44 , 8 3 & CNMI AN) Sie Waray eecmnreer es n BI = Ss .2 i) Sas Ss es = z g Sas pois s§ gs 25 3 = = = s a> aS = Bn = 3 ° aS ro) N5§ NS 3° a R ra 3 q s S Septastrea excavata, EB. de From. ...... ve ‘* 4 i Montlivaltia polymorpha, Terq. ......-.- * = e — pedunculata, Dune.......... * "9 cre Tsastrea Sinemuriensis, E.de From....... * ss * Thecosmilia Martini, E. de From. «...... ad * be: <3 — Michelini, Terg. ............ * * . Ammonites angulatus, Schl. ............... see * oo ‘ fe Cerithium acuticostatum, Terq. ......... % 2 : x — gratum, "Terg: 2.2 1s...0: ere * - os 4 ==. § i Semele; D Orb. 2258. * oe * * any Turritella Dunkeri, Terg...............066+ x es * 43 — Zenkeni, Dunk., sp............. ves 8 % P “~ 2 Littorina clathrata, Desh. ............... 3 * * x ‘a Phasianella Morencyana, Piette ......... * * ie Neritopsis exigua, Terg. ..........0.seree * * ” Gervillia acuminata, Terg. ............+5 * ; . Ostrea irregularis, Minster (O. liassica, Derick had)" {.i:\:3:..05c setae * % * * Ff ° — multicostata, Miimst. ............ * * * ses — GROMAIG, TELQ,....... 5.002.000 cot * : * * 3 sn Lima tuberculata, Terg. .............06... * ® * 4 4 x Cucullea Hettangiensis, Terq............. * . Cardita Hebertt, Terg............0500009050 * vee ¥ Tamacenaltata, TVerg. isis. .cinvsciassh sovtes * ie aa * * GONE ONO ses us 25h 0s sbnsansetagne * * ve id Cardinia regularis, Terg. .............2.2+ * ve * * 4 *% Plicatula intusstriata, Emm. ............ * * * * x 1 Terquem et Piette, op. cit. 2 Cote d'Or. FROM THE ZONE OF AMMONITES ANGULATUS. 35 The range in space and in time of some of these species is very remarkable. Several of them range from the Italian to the Welsh Lias, and from the Zone of Avicula contorta to that of Ammonites Buckland; but the general grouping of the Gasteropoda, Lamelli- branchiata, and Madreporaria indicates a Zoological Province which flourished anterior to the characteristic fauna of the time of Gryphea incurva and Ammonites Bucklandi. The richness of the Glamorganshire beds beneath the arenaceous deposits containing Gryphea incurva in species and specimens is very evident. The Madreporaria are rare in the equivalent strata on the Continent. > IV. DescrierTIon OF THE SPECIES FROM THE ZONE OF AMMONITES ANGULATUS AT Marton, NEAR GAINSBOROUGH. At Marton,’ on the line of railway from Gainsborough, in Lincolnshire, to Lincoln, there are dull blue earthy and shelly limestones, which are very fossiliferous. These beds have been carefully searched for fossils, and a very rich and interesting fauna has been collected.° They occupy a position above the White Lias and below the blue compact limestones of the Ammonites Bucklandi series. The fauna is very characteristic, but the Madreporaria are allied rather to those of the equivalent beds of the Lower Lias in the North of Ireland and of the East of France than to the species at Brocastle and in the Sutton Stone. 1. Montitvatti1a Harmer, Chapuis et Dewalque. PI. X, figs. 24—32. “The corallum is simple, discoidal, and depressed ; the base is very slightly pedicillate ; the epitheca is very thin, ridged, and extends to the calicular margin. «The calice is circular in outline, slightly or not at all convex, and the central fossa is small and circular. “The septa are numerous, and form six cycles in six systems. ‘The primary and secondary septa nearly reach the centre of the calice, and barely differ from those of the third cycle. The septa of the sixth cycle are very small. All the septa are thin, and their margin is strongly crenulate ; those of the first and second cycles become thicker near the centre of the calice, and thinner at the periphery, where all the septa are about the same thickness.” (‘ Descript. des Foss. des Terr. Second. du Luxembourg,’ Chapuis et Dewalque, p. 268.) The resemblance of the species toa Cyclolite is noticed by MM. Chapuis and 1 P, Martin Duncan, ‘ Quart. Jour. Geol. Soc.,’ Feb., 1867. 2 ¥. M. Burton, Esq.,F.G.S., and the Rev. B. Chamberlin, F.G.S., have given me information on this section. 3 Ralph Tate, Esq., F.G.S., ‘‘ On the Fossiliferous Development of the Zone of 4. angulatus, &c.,” an unpublished paper from which I have obtained much information, and all my knowledge of the Molluscan fauna of Marton. 36 BRITISH FOSSIL CORALS Dewalque; and they remark that the base is ordinarily slightly convex, but sometimes perfectly horizontal ; moreover, they observe that the calice is more convex when the base is horizontal. . MM. de Fromentel and de Ferry have divided the species Montlivaltia Haimei into three : 1. Montlivaltia Haimei, Ch. et Dew. 2. “e tenuisepta, From. et Ferry. 3. 5 granigera, From. et Ferry. He doubts the propriety of admitting so great a variation in septal number and in septal ornamentation as must be tolerated if the species were left entire. A very considerable series of specimens of the species has been examined, and the distinctness of such forms as those considered worthy of the specific names ¢enwisepta and grangera has not been satisfactorily determined. Like the recent simple corals, Wondlivaltia Haimet may have had a great variability. It was a very common species, and therefore all the more likely to vary in its shape, septal number, and ornamentation. It is evident that there are forms of the species which are either concave or horizontal at the base; and others which are barely convex at the base, and which may become conical, sensibly taller than usual, and even cylindro-conical in shape. The convexity of the calice, or rather the exsertness of the septa, is often, but not always, correlative to this development of the base, and concave calices are not uncommon in the tallest corallites. The septal number varies in the development of part of the seventh cycle, and the dentate or crenulate condition of the septal edge is very variable. The diameter of the calices and the height of the corallum depend upon the age of the individual. It would appear that no British specimen exactly resembles the type from Jamoigne, but a variety from the Irish Lias at the Island Magee is nearer to it than any of the British forms. Localities. Marton, near Gainsborough; Newark, Notts; east shore of Island Magee, North of Ireland. In the Collections of Rev. P. B. Brodie, Mr. Burton, Rey. Mr. Chamberlin, the Geological Society, and the British Museum. 2. MONTLIVALTIA PAPILLATA (sp. nov.). Pl. X, figs. 15—18. The corallum is Cyclolitoid in shape, the base is slightly concave, and the calice is convex, there being a circular depression at the centre. The epitheca of the base reaches to the calicular margin; it is very thin, is marked with concentrical shallow depressions and elevations, and the costa are seen through it faintly. The calice is nearly circular. FROM THE ZONE OF AMMONITES ANGULATUS. 37 The septa are exsert, and the larger have very large dentations or papilla on them. The papillae are small at the margin and at the columellary space, but midway there are six or more of them which are very prominent. There are twenty-four septa, which reach the margin of the columellary space, and they are strongly papillated. Between two of the longest septa there are three others, one, the central, is longer than the others, which are almost rudimentary ; all are papillate. There are thus five complete cycles of septa, in six systems. The columellary space presents several small papilla, but they are septal. There is no columella. Diameter of calice, 3ths inch. Height of corallum, 2ths inch. Locality. Marton, near Gainsborough ; east shore of Island Magee, in the North of Ireland. In the Collections of F. M. Burton, Esq., F.G.S., Gainsborough, and R. Tate, Esq., F.GS. 3. MonTLIVALTIA PAPILLATA (sp. nov.). A variety. PI. X, figs. 19—21. The corallum is smaller than the type, and the papillee are smaller and sharper. Locality. Marton, near Gainsborough, In the Collection of Rev. B. Chamberlin, F.G:S. 4. Seprastr#Za FRomEnTeELI, Zerquem et Piette. Pl. XI, fig. 5. The corallum is massive, and resembles a flattened cone in shape. The corallite walls are very thin, and are fused together. The calices are polygonal, irregular in shape, and deep. The septa are thin, finely dentate, and rather wavy; they number from twenty-four to twenty-six in small calices, and from fifty-two to sixty-two in the larger. The fissiparous division of the calices is very constant, and occurs both in the midst of the calices and at their angles. It is very rare to observe calices which do not present _evidences of fissiparity, so that the calices are almost always double. _~ Diameter of the calices, about !rd to 2rds inch. Locality. Marton, near Gainsborough; Harbury, Warwick; east shore of Island Magee, North of Ireland. In the Collections of F. M. Burton, Esq., F.G.S., and Ralph Tate, Esq., F.G.S. The shape of the corallum is subject to variation, and the Marton specimens are massive and flat, whilst that from Harbury, belonging to Rev. P. B. Brodie, is very gibbous and irregular in shape. The specimens from the North of Ireland are also irregular in shape. The species has a considerable range, and it has been found by MM. 'Terquem et Piette’ in the “Calcaire a A. planorbis de Volfsmuhl, prés de Mondorf et de Beaufort.” But in 1 Terquem et Piette, op. cit., p. 129. 35 BRITISH FOSSIL CORALS England and Ireland it occupies a higher zone, and is accompanied by Montlivaltia Haimet and its varieties. The following Cephalopoda, Gasteropoda, and Lamellibranchiata accompany the Madreporaria just described in the section at Marton :? Ammonites Johnstoni, Sow. ‘ angulatus, Schl. Nautilus striatus, Sow. Cerithium Semele, D’Orb. Phasianella Morencyana, Piette. Turbo subelegans, Miinst. Turritella Dunkeri, Terquem. Cucullea Hettangiensis, Terquem. Anomia pellucida, Terquem. Cardinia Listeri, Sow. J ovalis, Stutch. Cardita Heberti, Terquem. Lima tuberculata, Terquem. », punctata, Sow. Pecten punctatissimus, Quenst. The following is a list of the Madreporaria from the zone of Ammonites angulatus at Marton : Montlivaltia Haimei, Ch. et Dew. a A 2 varieties. - papillata, Duncan. a ” a variety. Septastrea Fromenteli, ''erquem et Piette. V. DescrIprion OF THE SPECIES FROM THE ZONE OF AMMONITES ANGULATUS IN THE Norra oF IRELAND. In the subdivision of the Lias at Waterloo, Larne, where the Cephalopoda and Mollusca about to be mentioned are found, there is a very remarkable coral which cannot be classified with any of the genera of the Astreide. I have founded the new genus Oppelismilia to receive this species and another which belongs to the Lias at Harbury, and which will be described in the next part of this Monograph. In the Ammonites angulatus Zone on the east shore of Island Magee there are several species of Madreporaria. ' List furnished by Ralph Tate, Esq., F.G.S., as was also that at p. 40. FROM THE ZONE OF AMMONITES ANGULATUS. 39 Montlwaltia Haimei, Ch. et Dew., is found there, and the form has a greater resem- “blance to the Belgian type than to the specimens from Marton. The multiseptate and granular varieties of the species are also found. Monthvaltia papillata, Duncan, is noticed amongst the Irish coral-fauna, and Septastrea Fromenteli, Terquem et Piette, also. The Coral-fauna of the Zone of Ammonites angulatus of Lincolnshire is clearly strongly represented in the North of Ireland, and the Mollusca which accompany the Corals of the first locality are noticed to be associated with those of the last. There is a Montlivaltia of the MMJontlivaltia papillata type which is special to the Trish Lias. Oppelismilia gemmans is not found in any other locality than Waterloo, Larne. Genus—OPPELISMILIA. The corallum is simple, attached, and conical. ‘The epitheca is well marked, and reaches to the calicular margin. The calice is shallow, and the septa are numerous and close. There are no coste, and there is no columella. Gemmation occurs within the calice, and the bud, which has an epitheca, grows with the parent. ‘The genus thus includes Montlivaltize with calicular gemmation. OPPELISMILIA GEMMANS (sp. nov.). PI. X, figs. 33, 34. The corallum is short; it has a broad and flat calice, an oval space at the base where it was once adherent ; a strong epitheca, with circular markings, and there are no coste. The calice is flat and shallow, and its margin is sharp. The septa are very numerous and unequal. The bud on the calice has an epitheca, and its septa are faintly dentate. Height of the corallum, ths inch. Width of the calice, $ths inch. Locality. Waterloo, Larne, North of Ireland. In the Collection of Ralph ‘ate, Esq., F.G.S. ; The following new Montlivaltia is also from the Lias of Ireland : Montirvatt1a Hrpernica (sp. nov.). Pl. X, figs. 22, 23. The corallum is discoidal, the base is flat, and the calice is convex. The epitheca of the base is strongly marked concentrically. The septa are numerous, close, unequal, and are marked by small papille, which are very close together, and by flat eminences, which are also very close together. There appear to be nearly five cycles of septa, and the largest septa are papillose. 40 BRITISH FOSSIL CORALS. The diameter of the calice is ths inch, and the height of the corallum 2th inch. Locality. The eastern shore of Island Magee, in the North of Ireland. In the Col- lection of Ralph Tate, Esq., F.G.S. List or Species oF MADREPORARIA FROM THE ZONE OF AMMONITES ANGULATUS IN THE Norv or [RELAND. 1. Oppelismilia gemmans, Duncan. Montlivaltia Haimei, Ch. et Dew. Be u varieties. > papillata, Duncan. ce Eibernica, Duncan. Septastrea Fromenteli, Terquem et Piette. ‘The following Cephalopoda, Gasteropoda, and Lamellibranchiata were found asso- ciated with the Madreporaria in the zone of Ammonites angulatus of the North of Treland : Ammonites Johnstoni, Sow. 3 angulatus, Sch. Nautilus striatus, Sow. Acteonina fragilis, Dunk. Cerithium Semele, D’ Orb. » gratum, Terquem. Phasianella Morencyana, 'Yerquem. Pleurotomaria capa, 'Terquem. Turbo subelegans, Mist. Turritella tenuicosta, Portl. Pecten calvus, Goldf. Plicatula Hettangiensis, Terquem. * intusstriata, Emm. Terebratula perforata, Piette. Avicula Sinemuriensis, D’ Orb. Cardinia Listeri, Sow. “ ovalis, Stutch. Cardium Philippianum, Dunk. Lima acuticosta, Mist. ,», tuberculata, 'Terquem. Ostrea irregularis, Minst. FROM THE ZONE OF AMMONITES ANGULATUS. Al VI. Description OF THE SPECIES FROM LUSSAY IN THE ISLE OF SKYE. Dr. T. Wright has described the Coral-bed of the Lower Lias of Skye, and the species of Jsastrea which, grouped in masses, appears to be the only Coral found there. It is most probable, from the position of this coral-bed,' and the association of Ostrea arietis and Cardinia concinna with it (in the bed beneath), that Jsastrea Murchisoni belongs to the same geological horizon as the Liassic deposit at Brocastle and the Sutton Stone. IsastR@A Murcuisoni, Wright. Pl. XI, figs. 1—4. Dr. Wright’s description of this species gives the following characters : Corallum large, massive, convex. Calices unequal, deep, polygonal; sides unequal. Margin thin. Septa, 30 to 36, and even 40 or more in the large calices ; unequal in length, thin, waved, granulated superiorly. Columella absent; point of convergence of septa excentral. Diameter of calices, ;{ths to ths inch. Depth of fossa, 3ths inch. Locality. Lussay, Skye. The surface of the type specimen is very uneven; the calices are very irregular in size, shape, and depth, and the margins are not even. Thus one calice may be on a higher level than those to which it is attached, and often so much so that there is a faint trace of a subsequent growth of wall. The septa are very irregular in their number, and the longest have one or more teeth at their immer end. There is often a ridge between the margin of the calice and the centre, mdicating calicinal gemmation, but the gemmation of the corallum usually takes place at the margin, and there is no fissiparity. No cyclical arrangement of the septa can be distinguished. The large and shallow calices, thin septa, the peculiar relation of contiguous calices, and the sharp elevated margins, distinguish this species, which is allied rather to a new genus from the Middle Lias of Pabba, Zepidophyllia (Duncan), than to any of the Liassic Isastreeze. ' See Mr. Geikie’s memoir “On the Geology of Strath, Skye ;” with “Descriptions of Fossils,” by Dr. T. Wright, 1857, ‘Quart. Journ. Geol. Soc.,’ vol. xiv, pp. 1 ef seg. There is a most interesting description of the Coral-bed in the Isle of Skye by Hugh Miller, in his “ Essay on the Corals of the Oolitic System of Scotland,” read before the Royal Physical Society of Edinburgh, and published in ‘The Old Red Sandstone,’ 7th edition, 1859. 2 «Quart. Journ. Geol. Soc.,’ vol. xiv, p. 34. 42 BRITISH FOSSIL CORALS VII. List oF THE SPECIES DESCRIBED IN THIS PART FROM THE ZONES AMMONITES PLANORBIS AND AMMONITES ANGULATUS. Oppelismilia gemmans, Duncan. Montlivaltia Wallie, 32 Murchisoniea, ,, polymorpha, Terquem et Piette. parasitica, Duncan. simplex, . brevis, 2? pedunculata, ,, Haimei, Chapuis et Dewalque. papillata, Duncan. EMibernica, ,, Suttonensis, ,, mirabilis, eS serialis, A rugosa, Laube. Brodei, Duncan. Martini, ¥. de Fromentel. Michelini, Terquem et Piette. erregularis, Duncan. Terquemi, ,; afinis, ¥ dentata, HM plana, Rhabdophyllia recondita, Laube. Astrocenia gibbosa, Duncan. plana, x INSUGNIS, a reptans, ” parasitica, ,, pedunculata, ,, costata, ee JSavoidea, x superba, + dendroidea, ,, OF FROM THE ZONES OF AMMONITES ANGULATUS AND PLANORBIS. 43 35. nik (hay Hitt * i F OT rab ha niente sg Aas one “ att F Se . - i La me - | ate ae w PLATE I. LIASSIC CORALS FROM STREET AND BROCASTLE. . Septastrea Haimei, Wright, sp. (P. 5.) . The base of the corallum. . Calices, magnified. . Fissiparous calice, magnified. Septa, magnified. . Septastrea excavata, K. de From. (P. 32.) A calice, magnified. . The usual appearance of longitudinal sections in the Brocastle beds, magnified. Pia. itd VRE a om) Coy See SOS iol ~~ Ll. . 16. | PLATE II. LIASSIC CORALS FROM THE SUTTON STONE. Thecosmilia rugosa, Laube. (P. 13.) Its calice, magnified. A fissiparons calice, magnified. A corallite, magnified. Part of the wall, some septa, and some dissepiments, magnified. A deformed corallite. Rhabdophyllia recondita, Laube. (P. 17.) Part of its transverse section, highly magnified, to show the septal arrangement. The cost, magnified. The corallite has Astrocceenia parasitica upon it. Thecosmilia mirabilis, Duncan. (P. 12.) A calice, hghly magnified. Montlivaltia pedunculata, Duncan. (P. 10.) Its costee and epitheca, magnified. Peduncles of Thecosmilie. ‘ ‘ , ‘ Ji ~- * ‘ ’ J ~ ' 7 a » . - ’ « ’ “4 ° \ is ~ of, a = ' > a P »- , ° ‘ . “) . » ‘ PLATE III. LIASSIC CORALS FROM BROCASTLE. Fic. 1. Thecosmilia irregularis, Duncan. (P. 15.) 2. Its upper surface, magnified. 3. Its epitheca, calices, and base, magnified. 4. A circular calice, magnified. 5. Septa (upper margin), magnified. 6. Side view of a septum, with terminal tooth. 7. Thecosmilia Terquemi, Duncan. (P. 16.) 8. Its base, magnified; the epitheca has been worn, and the costa are seen with dissepiments. 9. Its upper surface, magnified. % } Its calices, magnified. 12. A side view of a septum, magnified. 13. A variety of Zhecosmilia irregularis, Duncan. (P. 15.) 14. Its calice, magnified. 15. A side view of a septum, magnified. b> 2 CY wre > rw %w Ww rag Ot + Montlivaltia simpler, Duncan. (P. 9.) Its calice, magnified. Thecosmilia afinis, Duncan. (P. 16.) A calice, magnified. A side view of a septum, magnified. Thecosmilia dentata, Duncan. (P. 16.) Its calice, magnified. A septum, magnified. Thecosmilia plana, Duncan. (P. 17.) Part of its calice, magnified. = a ov One 0 32 jan PLATE IV. LIASSIC CORALS FROM THE SUTTON STONE. Cyathocenia incrustans, Duncan. (P. 28.) Some calices, magnified. Casts of Astrocenia gibbosa, Duncan. (P. 18.) Astrocenia reptans, Duncan. (P. 20.) ‘} Its calices, magnified. Calices altered by fossilization, magnified. Thecosmilia Suttonensis, Duncan. (P. 11.) Side view of the corallum. | A calice, magnified. Thecosmilia serialis, Duncan. (P. 12.) Upper surface of the corallum. A serial calice, magnified. Montlivaltia parasitica, Duncan. (P. 9.) Its calice, magnified. |} De Wilde hth ¢ a 0 PLATE V. LIASSIC CORALS FROM THE SUTTON STONE AND BROCASTLE. . Astrocenia plana, Duncan. (P. 19). The corallum, natural size. . Astrocenia gibbosa, Duncan. (P. 18.) A corallum, with much coenenchyma. . A corallum somewhat worn. . The usual appearance of the Coral in the Sutton Stone ; all the calices have been worn away, and it requires some trouble to distinguish the fossil. 2. A section at right angles to the corallites, highly magnified. The columella, the ee BS SG ey Gt — faint lateral dentations of the septa, and the round ornamentation between the costal ends are shown. . Astrocema parasitica, Duncan. (P. 20.) . 'The same, magnified. ‘The Coral is parasitic on Rhabdophyllia recondita. . Astrocenia pedunculata, Duncan. (P. 20.) The corallum, magnified. . The corallum, natural size. . A view of the peduncle and base, magnified. . Cyathocenia costata, Duncan. (P. 29.) The corallum, natural size. . Some calices, magnified. ¥ bene 2 fe Rite Od i t eR uacts =a PLATE VI. LIASSIC CORALS FROM THE SUTTON STONE AND BROCASTLE. Fic. 1. Astrocenia gibbosa, Duncan. (P. 18.) Some calices, magnified, showing a very usual state of preservation. 2. .A worn calice, magnified. 3. A side view of worn calices, showing the dense intermediate tissue, and faint traces of endotheca, magnified. 4. A side view of a calice, magnified. 5. Llysastrea Fischeri, Laube. (P. 29.) A transverse section of part of the coral- lum, slightly magnified. 6. A transverse section showing some corallites not united by their walls. 7. The septa of neighbouring calices, the walls being united, magnified. 8. Corallites which are separate, and covered with epitheca, magnified. 9. ‘This is a diagram, and shows the plan of the genus. 10. Hlysastrea Moorei, Duncan. (P. 30.) Upper surface of corallum. ll. A calice, magnified. 12. oe 3 2 13. United calices, magnified. 15. A corallite, showing costa, the epitheca having been worn off. « * . t . . ‘ : } ve e } ' ? ® me a" ro 7 ‘ * Fic. ifs 2. 3. PLATE VII. LIASSIC CORALS FROM BROCASTLE. Isastrea Sinemuriensis, 0. de From. (P. 30.) The upper part of its corallum. The calices slightly magnified to show the marginal gemmation. 4. Another view. 6. a 8. 9. 10. Tike 12. 13. 14. 15. } Calices, magnified. Septa, magnified. A corallum with larger calices than is usual. Calices, magnified. Thecosmilia Michelini, Terquem et Piette. (P. 14.) A large variety. Its calice. A corallum bifurcating. Its calice, magnified. Montlivaltia polymorpha, Terquem et Piette. (P.8.) A fractured corallum. A transverse section, magnified. CORALS reared lal ix ’ va e . A ' ¢ j yet ‘ 4 ; a) vie fy Wis ae Ps p j uy; ya ay V r a ; ye ‘ ‘ i ! ie i . : ‘ ‘ : o W oe: AE | an > , by ae > ‘ ; ; ‘a , OC ah tae Pd > te FA ya , 7 PS Diino abt 4 Te 6. _ ' y pa hes ’ grt Lee Pt d a 4 ato ean PLATE VIII. LIASSIC CORALS FROM THE SUTTON STONE AND FROM BROCASTLE. . Montlivaltia polymorpha, Terquem et Piette. (P. 8.) A long and large specimen. . A part of its transverse section, magnified. . Exothecal and endothecal dissepiments, cost, and septa, magnified. . A smaller corallum. . Two corallites springing from a common base. . Septa of a young corallite, magnified. . Costee and exotheca of a young corallite, magnified. (See also Pl. VII, figs. 14 and 15.) . Montlivaltia Walia, Duncan. (P. 7.) A corallum in the rock. . Acalice, slightly magnified. . A side view of a septum, magnified. . Montlivaltia brevis, Duncan. (P. 10.) A corallum on the rock. . A calice, magnified. . Montlivaltia Murchisonia. (P. 8.) A corallum. . A part of the calice, magnified. . The peculiar costal arrangement and septa, magnified. . Montlivaltia pedunculata, Duncan. (P.10.) A corallum. . Isastrea globosa, Duncan. (P. 31.) A corallum, the calices are worn. . Calices, magnified. Fie. . Astrocenia insignis, Duncan. (P. 19.) . Calices, magnified. =e WwW woe oe on o oH 10. Id; i: 13. 14. 15. 16. ve 18. 19. 20. PLATE IX. LIASSIC CORALS FROM BROCAS'TLE. . Astrocenia superba, Duncan. (P. 21.) . A calice, magnified. . A side view of a calice, magnified. . Cyathocenia dendroidea, Duncan. (P. 27.) A corallum. . A calice, magnified. . A calice, magnified ; a side view. . A transverse section of a stem, showing the concavities produced by the calices and the intermediate coenenchyma. Astrocenia dendroidea, Duncan. (P. 22 A calice, magnified. Astrocenia favoidea, Duncan. (P. 21.) Calices, magnified. A side view of a calice, magnified. Astrocenia costata, Duncan. (P. 21.) Calices, magnified. A corallum. Astrocenia minuta, Duncan. (P. 22.) A calice, magnified. A side view of a calice, magnified. A corallum. Part of a corallum. .) A part of a corallum. A corallum. A corallum. A corallum. “” ‘ } F ' j x 7 i a t : é ‘ f . : ? = > . L : ; , 5 ‘ PLATE X. CORALS FROM BROCASTLE ; MARTON, NEAR GAINSBOROUGH ; NEWARK, IN NOTTINGHAMSHIRE ; and 8. 23. 24, Doe 26. 27 and 28. 29. 30. 31 and 32. oor 34. AND FROM THE NORTH OF IRELAND. Thecosmilia Brodiei, Duncan. (P. 13.) The upper part of a corallite, natural size. The calice, magnified. A side view of a septum, magnified. A septum seen from above, magnified. Some corallites of Thecosmilia irregularis, Duncan. (P. 15.) Showing the gemmation from the calicular edge, and the rough and ridged epitheca. A corallite of Thecosmilia Martini, K. de From. (P. 14.) Views of its transverse section and calice, magnified. Corallites, with strong epitheca. A section of a cast of Thecosmilia Michelini, Terquem. (P. 14.) From Cowbridge, magnified. The calicular end of a corallite. The calice, magnified. A corallite, showing the rounded ridges of the epitheca. A calice. The upper surface of Montlivaltia papillata, Duncan. (P. 36.) A side view of the calice. Septal dentations, magnified. The base of the corallum. Montlivaltia papillata, Dunean, variety. (P. 37.) Its calice. The side of the calice. The septa seen from above, magnified. Montlivaltia Hibernica, Duncan. (P. 39.) Its calice. The septa seen from above, magnified. Montlivaltia Haimei, Chapuis et Dewalque. (P.35.) The Irish form. View of the calice. The septa seen from above, magnified. A variety of Montlivaltia Haimei. The calice. Views of the corallum. A variety of Montlivaltia Haimei. The calice. The side view of the corallum. cs Unusual shapes of the corallum. Oppelismilia gemmans, Duncan. (P. 39.) The calicular surface, showing calicular gem- mation. The side view of the corallum. ." 2s Milde, lith r 1 M &N. Hamhart imy et Nhe. a CS ‘ ‘ 8 PLATE XI. LIASSIC CORALS FROM LUSSAY, IN SKYE, AND MARTON, NEAR GAINSBOROUGH. Fie. 1. Lsastrea Murchisom, Wright. (P. 41.) 2. Calices, magnified. 3. A calice, magnified. . 4. Aseptum, magnified. Oe Septastrea Fromenteh, 'Terquem et Piette. (P. 37.) Some fissiparous calices, slightly magnified. cI Pl ie q Ei ree Zz « Zz as =] } | CS) & t) == ud om) <—{ — 3 he ice a = = PALAONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVIL. VOLUME FOR 1866. LONDON: MDCCCLXVII, 1a RPG ia sl i po ae se A MONOGRAPH OF BRITISH TRILOBITES. BY ave oA LER, A.L.S.,.. F.GiS., LATE OF THE GEOLOGICAL SURVEY OF GREAT BRITAIN. PARE LY; CONTAINING Paces 177 to 216; Prarzrs XXV* to XXX. LONDON: PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY. 1867. NOTICE TO CORRESPONDENTS. In our next part it would be in some respects advisable to go on with the highest and most compact group of the smooth-eyed Trilobites (see p. 2), viz. the Proetide, which comprise the Carboniferous species; but though materials are abundant, they are not complete, and the specimens are much scattered; I shall therefore, in Part V, after the Bronteid@ are finished, proceed with the lower groups, viz.— AAGLINIDZ—given at p. 124 as a subgroup of the Asaphide, but possibly distinct, and certainly much lower than the others. TRINUCLEID#—for which materials are in plenty. AGNoOSTID£—now of many species. With these we shall close the First Volume. In Vol. II it is proposed to follow the left-hand column (p. 2), through the “ pri- mordial’’ genera of the Olenide and Conocephalide, which are already numerous, and will be still better known by that time ; then to take up the more aberrant groups—Lichade, Acidaspide, Harpedide, &c. ‘This will lead us to the Cyphaspide, before describing the Proetide : and there is an intimate relation between the two last-named groups, in spite of the numerous free body-rings which characterize the one, but which are soldered into a large post-abdomen or tail-piece in the highest and terminal forms of the Proetide,— viz.: the Carboniferous species of Phi//ipsia, &c. I beg to thank our numerous friends for their ready help. Many additional species of the groups already passed in review have, of course, turned up; but these will best appear in the Appendix to Vol. II, should health and leisure be granted me to complete the work. If not, I shall have indicated, I hope, the right path for my successor. Our friends, therefore, will please to communicate all their best specimens (with strict localities) of the three groups above mentioned. They may be left at the Geological Society ; or forwarded to me at 45, Great Russell Street, or to— 8, Bolton Road, St. John's Wood, London. April 29th, 1867. J. W. Saver. OGYGIA. 177 ASAPHID Ai—continued: Ocyeta, &c. As must sometimes happen, in writing a continuous monograph, new materials, connected with plates and descriptions already completed, turn up just as the work has passed through the press; and if such material refer to plates long since issued, it would be of course desirable to leave the new matter to the end of the work ; but if not too far removed, it is as well to insert it as nearly as possible in its place. Before proceeding, therefore, to the description of ///enus, to which group the present part of the Monograph is restricted, we give a plate (numbered Pl. XXV*) of Ogygia peltata, containing the new and more perfect specimens to which reference has been made in the “Corrigenda” of the volume for 1864. A new species has also occurred in the same locality, and from the same formation (the Arenig or Skiddaw Rock, a set of beds but little known). I had better describe the two forms of Ogygia together; I take also the opportunity of inserting a new Barrandia at the same time. Oeyeia peLtata, Salter (Pl. XVII, figs. 8—10). Pl. XXV*, figs. 1—4. In page 133, line 1, it was stated that on Pl. XVII, figs. 9 and 10 are wrongly marked as O. peltata; and in page 134, our fig. 10 was described as O. scutatrix, a species which is only yet known from the Tremadoc Rocks. The mistake arose, as stated in the Corrigenda, from laying too much stress on the broad form and broad axis of the female form (‘forme large’ of Barrande), which in Ogygia peltata resemble those of O. scutatrix: and, following the same idea, the head of the broad form, with its wide labrum, was also described as O. sevtatriz (p. 133, line 22, &c.). These mistakes are now rectified by the accompanying plate (Pl. XXV*), which exhibits fine specimens of the broad form (figs. 2, 4) ; the shape of the head, with its oblong parallel-sided glabella, in fig. 1; and the labrum, of full size (fig. 3). The eyes, it will be observed, approach the glabella closely, as in Pl. XVII, fig. 10, and are not placed wide apart, as in fig. 8 of that plate, which, copied from the best reconstruction I could formerly give of the species, gives an incorrect idea of all but the general proportions. The fulcrum-points of the axis, &c., are also imperfect, so we had better erase the figure entirely. It is not very pleasant to admit so many errors, but it is a shorter plan than trying to defend or excuse them. The description in page 135 is more correct; but the glabella is not so wide as the cheeks, nor the axis of the thorax as the pleure ; and these latter have the fulcrum placed at less than one half out instead of two-thirds. The pleural: groove is nearly straight, only a little sigmoid; and the tips are truncate, not 23 178 SILURIAN TRILOBITES. falcate. The groove ends abruptly a little way within the tip. In the tail eight furrows cross the axis, the last three not quite complete. The interlining furrows are certainly not so long nor so distinct as in our former description and figure. The followimg is the new form which occurs with O. peltata at St. David’s : Ocycia BULLINA, n. sp. Pl. XXV%, fig. 5 O. plana, modica, biuncialis, capite semicirculato, fronte latiorr, angulia—? Glabella pyriformis, ad basin angustata, lobisque basalibus inflatis; gene absunt. Oculi prope glabellam, in medio capite positi. Thorax axe angustissimo, pleuris rectis, fulcro ultra medium posito. Cauda? Labrum ? A neat species, which was sent by my asses ae Henry Hicks, Esq., of St. David’s, from the beds at Whitesand Bay. The form is broad-oval. We have but the head, without free cheeks, and eight or nine of the body-rings, but there is enough to show that the fossil is quite new. The head is broader than a semicircle, and has a wide, coarsely striated front (the squamate striz are not visible in our figure) ; a pyriform glabella, inflated in front; strong basal obliquely oval lobes, projecting beyond the neck of the glabella, and separated from it by rather strong lmes. Neck-furrow of the glabella tolerably strong, and much broader than that beneath the cheeks. ye-lines above and below the eye widely diverging; the eye short, and placed about halfway up the head, but even closer to the glabella than in O. peltata, which species accompanies it. Beneath the eye the suture curves so largely out that it must nearly reach the angle of the head. We have not the free cheeks, and of course do not know anything of the spines; I suppose these must have been short. Thorax with a very narrow and somewhat prominent axis, which is about half as wide — only as the flat pleura, and these are nearly direct ; the slight fulcrum, placed beyond the half of the pleura, being scarcely an angular bend at all. The facet, however, is very distinct and sharp-edged. Fine curved transverse strize cover closely the glabella, and are traceable on the axis of the thorax. The much coarser striz on the fascia beneath the pleure range up to the fulcrum, but not within it. Locality—AreEnie Rocks. North-east angle of Whitesand Bay, St. David’s (Wood- wardian Museum, Cambridge). The species should be sought for in the same beds on Ramsey Island. My lamented friend Mr. H. Wyatt-Edgell found a new Barrandia in the black shales of Abereiddy Bay. (For this genus, see p. 137, &.) We are only able to give a woodcut ; and it is a melancholy pleasure to introduce a description in this work from his pen. a a ? bGrwipajatoe ea BARRANDIA. 179 “ BaRRANDIA (HoMALOPTEON) LoneiFRons, Ldgell. Woodcut, fig. 42. “ B. (Homalop.) magna, 4 uncias feré longa; cui glabella producta claviformis, oculi propingur (sulcus cervicalis abest?). In thorace awis latitudo dimidium latitudinis pleurarum, quarum sulci pene aciem attingunt, efficit. Cauda semiovata axem conicum gerit, dimidium longitudinis ilius eficientem ; latus quodque sulco unico furcato distinctum. “A very large species, with a projecting club-shaped glabella; the axis of the thorax about half the width of the pleure; and the tail semicircular or rather semi-oval, each side bearmg one strongly branched furrow only. The long clavate glabella, with undulated sides cor- responding to the glabella-furrows, projects about one third of its whole length beyond the anterior margin of the cheeks, which are at their base one third wider than the base of the glabella. The rather large eyes are placed considerably forward and close in to the glabella. The fixed cheek is very broad, and the facial suture curves widely out beneath the eye, so that the free cheek is much narrowed, its outline arched almost in a semicircle; it has a narrow but very distinct margin ; it shows, so far as our only'specimen can be trusted, no neck-furrow (the front thorax-ring has been pushed under the head and appeared to us at first sight as a branched neck-furrow), the cheek ends _pos- teriorly in a small needle-shaped head-spine. “There are, apparently, seven thorax-rings, as in some other species of this genus. The pleural furrow —Barrandia (Homalopteon) longifrons, Edgell. 5 : : Llandeilo Slates, Pembrokeshire. Mr. H. is well defined, and reaches almost to the tip of each Wyatt-Edgell’s Cabinet. of the recurved flat pleure. “The tail, fig. 43 (natural size and enlarged), found in the same locality, is supposed to belong to this species, as only one other Barrandia Higude: (B. Cordai, M‘Coy, a small species) is known to occur there. The length of this caudal portion is almost equal to its breadth; the axis is conical, the base being about half the length. The side has two furrows, or perhaps a strongly branched one (the yyy of 2, (Eiasast) pinafroiee > Randelia branch arising as usual from the very base, and Slates, Pembrokeshire. From the same indicating the suture of the first tail-segment): these res % Natural sizes 2 enlarged. nearly reach the outer margin; but no corresponding furrows occur on the smooth conical axis, which is half the length of the whole tail, and ends apparently in a sharp tip, from 180 SILURIAN TRILOBITES. whence a raised line runs to the margin, a common circumstance where the axis is abbreviated. “Length of head and thorax taken together three inches ; length of the supposed tail (of a younger individual) five lines. “ Zocality—LuanvDEILo Siates of Abereiddy Bay, Pembrokeshire ; in my collection.” —H. Wyatt-Hdgell. We may now proceed with the most abnormal of all the Asaphide—the group of Iilenus, so very characteristic of Lower Silurian—the “ Faune Seconde” of Barrande. It is true that in one of its subgenera it rises into the Upper Silurian; but the mass of the species, and especially the abundance of individuals of this genus, mark Llandeilo and Caradoc rocks (Lower and Middle Bala of Sedgwick) most effectually. (Lower, Middle, and Upper Bala rocks of Sedgwick are equivalent to Llandeilo, Caradoc, and Llandovery. | InLznvus, Dalman, 1826. Of all the higher Trilobites, this is the most abnormal in shape ;—the segments of the large head, and of the equally bulky tail, being so condensed and obliterated as to leave those portions like the rudimentary extremities of an Agnostus; while the structure of the pleurz, the form of.the head, eyes, labrum, and rostral shield—the thick sculptured crust, and the perfect mobility of the thorax-rings, all mark the genus as one of high rank among the Asaphide, and as nearly allied to the Proetida, the highest of the smooth-eyed groups. All the species of the genus have a common facies :—the similar head and tail, un- marked by lobes or annulations ; the glabella, cheeks, and margin being usually confounded in one hemispheric mass; and the axis, in most instances, scarcely indicated outside the caudal shield. The creature could roll itself up into a perfect ball, and, no doubt, chiefly suggested to Dr. M‘Leay the analogy with Bopyrus and other Isopoda ; the resemblance to the Armadillo Woodlice is not less striking. Yet the Zsopoda have crustaceous feet well articulated, and we have yet to learn that Trilobites had any crustaceous feet at all.? ‘ I find that every one in our own country has overlooked a very important notice, by Dr. Volborth of St. Petersburg (‘ Verhandl. Min. Gesellsch. Petersburg,’ 1857-8, p. 168), of the discovery, by Dr. Pander, of some appendages, which may be membranous feet, attached to definite parts of the outer portion of the pleuree beneath. I do not know that Dr. Pander has published this in any definite form, but Dr. Volborth has fully described and figured these points of supposed attachment for swimming feet (‘ Mém. Acad. Imp. Petersb.,’ 1863, tom. vi, No. 2). Barrande observed them in 1855, in Ogygia, and described them in 1898. Mr. E. Billings, Palzeontologist to the Canadian Survey, has also found in dAsaphus gigas a trace or two of curious processes below the crust, but close to the axis. All these data have great value; and those who have abundance of specimens of Asaphus expansus, from the fine Lower Silurian mudstone of St. Petersburg, will do well to cut and polish specimens, observing all traces of fragments of the general lower membrane, as well as of distinct processes (for details see ‘Mém. Acad. Imp. Petersb.,’ 1863). ILLAINUS. 181 Illenus is as compact a genus as any in the whole Trilobite Order. It comprehends almost as many distinct, if less varied groups, as Phacops itself; and all of these have the common facies of an inflated head and caudal shield, without external lobes or rings, and that peculiar hemispheric contour to each, which is so marked a character of the whole genus. Sometimes, the angles of the head are shortly spinous (Dysp/anus), but usually they are rounded off and unarmed (J//enus, Bumastus) ; sometimes the eye is subcentral (17. centrotus), but more commonly it is placed behind the middle of the head, and near the posterior margin (Z/. crassicauda, Il. Bowmanni, &c.). A few have the axal furrows reaching quite up the head (J7. distinctus, Barr.), but in the great majority they reach less than two-thirds this distance—and are often less than half-way. In a very few the eyes are large (J/. ocularis), but usually they are small. The labrum varies in shape in the different subgenera (see figs. 44 a, 4). Lastly, the number of body-rings varies." Two sections, perhaps distinct genera, Panderia and Octillenus, have but 8 rings. Dysplanus, including species with both spimous and rounded head-angles, has only 9 rings. J//enus proper has 10 body-rings, and this includes many well-known species ; while Bumastus, Murchison, which, like [/enus, has 10 rings, has the axis very wide, and so little distinguished from the pleure as to give a. Labrum of Jilenus centrotus (after Volborth.) 6. Labrum of Jllenus crassicauda (ib.). a unique aspect to the fossil. I agree with Barrande,' that it is wiser, in the present state of our knowledge, to include all these subgenera under one common name; dividing them into groups, which may, by and bye, if the characters prove constant, be called genera. All of them appear to agree in the following characters : Head hemispherical, or rather quarter-spherical, with Fra. 45. rounded contour, no marginal furrows, and a very slight indication of neck-furrow. Glabella lobeless externally ; within it has often 4 pairs of lobes, and is separated by in- complete axal furrows from the tumid cheeks. Eyes lateral, remote. Epistome striate, with a well-defined transverse rostral shield, and bearing a somewhat triangular tumid labrum, which has a strong border and expanded base (see fig. 44 and Pl. XXVII, fig. 7). Body-segments 8—10; usually 10, without grooves to the pleure. Tail large, hemispheric, with a short incom- 3 " ae -. General type of [//enus. lete axis, showing numerous rings, but only within the crust. 7. centrotus, Dalm. North Russia. Pp S gs, The genus, world-wide in its distribution, is neatly dis- Ce Semon tinguished from all others by habit, as well as a combination of characters. These are 1 Barrande has enumerated 11 genera in which the number of rings is variable. 182 SILURIAN TRILOBITES. maintained, though under considerable variations, throughout the North and Central European types and those of Canada and North America. The greatest variation is found among the oldest forms, viz., those from the Arenig and Llandeilo rocks, where the genus first appeared. If we look to our plates, we shall find that the ordinary species of Z//enus have the furrows which mark out the glabella very short externally, and the eye placed at a moderate distance or somewhat remotely from the glabella, and behind the middle of the cheek. But in the oldest: group of Silurian rocks known to contain J//enus, the eyes are placed so far forward and outward, that in one form, Ectillenus (Pl. XXVI, fig. 8), they seem at first to be absent altogether; and in Hydrolenus, a Canadian subgenus (L//enus conifrons, Billings), the glabella-furrows are so long as to reach the front, the glabella so gibbous as to overhang it, and the eyes are extremely forward. These two subgenera lead directly to Tl/enopsis (Pl. XX, fig. 1), which is from the Arenig rocks (it has been quoted from May Hill Sandstone !). If we divide Illenus into the undermentioned sections, following the lead of previous authors, it is not because we think the divisions quite natural, but because they are convenient. Some of the subgenera will be hereafter elevated to generic rank when we know more of the lobes of the head, not often visible even in internal casts. § 1.—Trilobed: labrum elongate. 1. Octillenus, Salter, 1866. Hight rings; a well-defined glabella, and the upper pair of pleurze produced. Lower Silurian, Central Europe. Ilienus Hisingeri, Barr. 2. Panderia, Volborth, 1863. Hight body-rmgs; short glabella-furrows, and ordi- nary ungrooved pleure. Lower Silurian, North Europe. Il. triquetra, Volb. Il. Lewisii, Salter. 3. Dysplanus, Burmeister, 1843. Nine rings ; ordinary pleuree. Lower and Middle Silurian. Il. centrotus, Dalm. Il. Bowmanni, Salter. 4. Illenus proper, Dalman, 1826. Ten body-rings ; ordinary pleure ; eyes subcentral. [The greater number of species belong to this subgenus.] Lower Silurian, universal. Il. crassicauda, Wahl. Il. Murchisoni, Salter. Il, Davisii, Salter. Il. Rosenbergii, Eichw. 5. Letillenus, Salter, 1866. Ten body-rings; ordinary pleure ; eyes remote and very forward; glabella-furrows short. Lower Silurian, only British as yet. Il. perovalis, Murch. 6. Hydrolenus, Salter, 1866. . Eyes remote, forward; glabella-furrows reaching the front ; head most gibbous. Lower Silurian, Canadian. Il. conifrons, Billings. ILLANUS. 183 7. Illenopsis, Salter, 1865. Eyes remote, forward ; glabella-furrows reaching the front ; head not gibbous, only convex; pleure grooved. [Probably a distinct genus. | Lowest Silurian, British. Il. (Illenopsis) Thomsoni, Salter. [Not Illenus Thomsoni. ] § 2.—Body scarcely trilobed: labrum short. 8. Bumastus, Murchison, 1837. Eyes large, remote, backward; ten body-rings. Lower and Middle Silurian, but chiefly Upper; universal. Il. Barriensis, Murch. Il. insignis, Hall. Tl. carinatus, Salter. Il. Trentonensis, Hall. Subgenus 1.—Of Ocrittanus we have no British types. It is a Lower Silurian Bohemian form. We give a woodcut (fig. 46), as it is so peculiar a form of the group, from Barrande’s figure. The enlargement of the first pair of pleure is a very unusual character in the Asaphoid or smooth Trilobites. Il. (Octil.) Hisingeri, Barr. Lower Silurian, Bohemia. Subgenus 2.—Panpertia, Volborth, 1863. ILLznvus (PanpertA) Lewis, n.sp. Pl. XXVI, figs. 2, 2a, 4 (nat. size and magnified. Ul. (Pand.) minimus (forsan junior ?), 3, uncie longus, vie % latus, ovatus, capite (glabellé precipue) gibbo, thoracem longé superante, et caudd planaté bis feré longiort. Caput subtrigonum, fronte paullo producta, angulis obtusis marginatis. Glabella post verticem gibba, 5 latitudinis capitis efficiens, oculos attingens. Sulci axales brevissimi, ad basin glabelle solum conspicut. Oculi magni, glabellam appressi, dimidium diametri suorum a margine distantes. Thorax axe modico, anticé latiori, pleuras subplanas superante. Cauda brevis semiovata planata, axe longo, per totam longitudinem conspicuo. _Had not Dr. Volborth figured two species of this very distinct subgenus, one of which is given on the next page, I should have taken this for the young of some undescribed species. The large size of the head and eyes relatively to that of the tail, and the more complete marking out of the axis in the caudal shield, are characters belonging usually to young specimens. But there can be little doubt we have here nearly, if not quite, the adult form of a subgenus not heretofore described from Britain, and apparently rare even in Northern Europe. We owe our single specimen to the care of Mr. Lightbody, who obtained it for this work from the cabinet of the Rev. D. P. Lewis, of Guilsfield, near Welchpool. It is a valuable addition to British fossils. The width of our single rolled-up specimen at the base of the head is 5 lines, and, the length of the large head being fully 4 lines, we may reckon the whole specimen as 7 or 8 lines long. The form, unrolled, would be ovate, the gibbous head being 184 SILURIAN TRILOBITES. somewhat trigonal, with the front a little produced, the sides flattened, and the hinder angles much rounded. The head is very gibbous, a section of it across the eyes, as shown in fig. 2, being a broad parabola.. The principal gibbosity les in this line, about the base of the great eyes. These are closely appressed to the glabella, so as to abut at their lower end on the short axal furrow, which is conspicuous here, but is not carried further up. And the eyes are placed about half their length distant from the posterior margin of the head. The course of the facial suture, below the eyes, is abruptly outward; above them it runs direct to the front margin, in a line continuous with that of the short axal furrows before noticed. 'The cheeks are much flattened, and decline rapidly, and our figure 2a rather too strongly expresses a marginal furrow within the angle—a character common enough in other genera, but extremely rare in ///enus. The thorax, of only 8 rings, has a broad axis, which tapers backwards, and is gently convex. The pleure are not so wide as the axis; they are flat as far as the fulcrum, which is placed at one half in the hinder rings, and is pretty close to the axis in the front ring ; thence they bend a very little downward and backward to the oblique tips. The tail is less than a semioval, and has the front edge straight. The axis is equal in breadth to the sides, and reaches down three fourths the length of the tail; it is rounded at the tip, flattened above, and with a distinct furrow all round it. The tip is very little prominent, but clearly defined by the prominence, as the sides of the axis also are by the axal furrows. The limb is flat, as, indeed, the whole tail is ; and only the edge turns gently downward. The relatives of this little species are clearly to be found in the Panderia’ triquetra and P. minima described by Dr. Volborth in his paper in the Fie. 47. ‘Transactions of the Imperial Academy of St. Petersburg,’ vol. vi, No. 2, 1863, pl. iu, figs. 13—19. One of these is given in our woodcut, fig. 47. Though I think Panderia only a subgenus, it is a very good and distinct one; and the eight body-rings, with their tapering axis, the flattened caudal shield with its long distinct axal lobe, and the large relative size of the head and eyes, mark it as an embryonic form (not using this word in a strict sense) of a comprehensive genus. The figure of P. minima is especially like ours in the gibbosity of the vertex, direct facial Il. pga clare Volb- suture in front, and approximated eyes; and it is about the same "size. Still, it differs in nearly all its proportions from P. Lewisii. Locality—Carapoc or Bata limestone of Moelydd, Oswestry,—near Llanymynech quarry (where “Fossils” is printed on the Ordnance Map). Cabinet of the Rev. D. P. Lewis). ‘ Named in honour of the veteran naturalist Dr. Pander, so well known for his works on the fossils of Russia. See foot-note, p, 180, for a reference to his discovery of the membranous feet of Trilobites. ILLANUS. 185 Subgenus 3.—Dyspuanus, Burmeister, 1843. Tuuanus (Dyspianus) Bowmanni, Salter. Pl. XXVIII, figs. 6B—13; Pl. XXX, fig. 6. ILLZNUs cENtTROTUS, Portlock. Geol. Rep., pl. x, figs. 3—6 (not fig. 9), 1843. In. Bowmannt, Salter. Mem. Geol. Surv., vol. ii, pt. 1, pl. vi, figs. 1—3, 1848; Decade 2, art. 2, p. 3, 1849; in Morris’s Catalogue, 2nd ed., p. 110; Appendix a to the Woodwardian Synopsis p. 4, 1852. Siluria, 2nd ed., passim, 1859; also Mem. Geol. Surv., vol. iii, p. 317, pl. xviii, fig. 8, 1866; and Catalogue Mus. Pract. Geol., pp. 5, 19, 1865. It. centrotus, M‘Coy. Synopsis Sil. Foss. Ireland, p. 54, 1846 ; Dysplanus, Synopsis Woodw. Fossils, pl. i 8, fig. 19, 1852. ; IL. LATUs, id. Ibid., fig. 17. Il. (D.) 3-4 uncias longus, convexus, levis nisi cauda lineis nonnullis \-formibus ornata ; capite valde convero caudam obtusam longitudine superante, thorace brevi. Caput semi- ovatum, convexissimum, sulcis axalibus brevibus, superne recurvis sepé claviformibus, per tertias longitudinis capitis extensis. Gene parve declives. Oculi minimi, distantes, basi capitis provimt. Anguli obtusi, nec spicula gerentes. Thoracis longitudo dimidium capitis totius eficit, annulis 9; axis ejus convexus, et pleuris anté latior est; at postice, in pullis precipue, angustior. Pleure fulcro tenus plane, dein recurve paulloque decurve. Fulcra anticé in tertias, postice in dimidium latitudinis pleurarum posita. Cauda lente convexra, semiovata, obtusa: cujus longitudo % latitudinis sue efficit; ave magno superné tantum inter foveas latas conspicuo, sulcis obscuris. Latera convexa, sulco superno lato, et interdum (in pullo) sulcis binis obscuris. A large species, frequently four inches long; oblong, with blunt and very convex extremities : the head not much larger than the tail, the thorax scarcely more than half the length of the head, and but little more compared with the tail; the eyes small and remote; the axis of the thorax wider than the pleure. Head regularly convex, semi-oval ; glabella wider than the sides, its furrows slightly converging as they reach one third up the head. Cheeks gently declining to the remote eyes, which are distant from the axal furrows about half the width of the glabella; and thence bend steeply down to the incurved margin. The eye is very short and small, and placed so far backwards as to be only its own length distant from the straight posterior margin. Free cheeks very small and narrow, with blunt rounded angles (not acute and produced as in Il. centrotus), The facial suture is nearly direct, 2. e. vertical above and below the eye. ‘The neck-furrow is distinct in casts, but beneath the cheek only ; a deep punctum at the base of the axal furrows defines its position under the glabella. The section of the head across the eyes is an arc of a circle about one third of the whole circumference, and from 24 186 SILURIAN TRILOBITES, front to back the curvature is similar, but more abrupt in front, where the forehead overhangs. Thorax about half the length of the head, and about three-fourths the length of the tail; of 9 rings. The axis gently convex, broader than the lateral lobes, and tapering but little backwards ; marked out by strong but not deep axal furrows from the pleure. These are flat as far as the fulcrum, which is at one third anteriorly, and at one half posteriorly. From this point the pleuree are bent gently down and a little backwards ; the front ones more so than the hinder ones, which !ast are nearly direct. Tail regularly and gently convex, half a broad oval; the length bemg two thirds the breadth. The upper angles are strongly truncated; the axis, which is more than one third the breadth, being only marked out by broad indentations in the upper part, and having no true axal furrows. The tail-margin is neither obtuse nor recurved, but regularly and evenly declines to the smooth edge. Caudal fascia concave, rather narrow, especially towards the upper angles, broader below, and not indented by the axis internally. Variations—In young specimens the glabella is narrower in proportion (Pl. XXVIII, fig. 8; and see also Portlock, Pl. 10). The thorax too is longer in proportion and more quickly tapering behind ; the tail is flatter, and so short as to be less than a semicircle (see also fig. 9). Such variations in the young state are common among the species of this genus. Rarely, as in Pl. XXVIII, fig. 11, the glabella-furrows are longer and more connivent, and more recurved above; fig..6, again, same plate, represents a May Hill Sandstone specimen, in which these furrows are shorter than usual. Some specimens have them straighter than others, and they vary a little in depth. Iilenus latus, of M‘Coy, is, I think, only a compressed specimen. We have several such forms from Pembrokeshire and elsewhere. It is figured in p. 215, woodcut 54. Our fossil has been referred both by Gen. Portlock and Prof. M‘Coy to the Swedish form, J/. centrotus. I cannot: clearly make out why; for the distinction of rounded (instead of spinose) angles was clearly pointed out by myself, m the Appendix to the Woodwardian Synopsis ; and I communicated freely with Prof. M‘Coy. I have re-examined the foreign specimens, and am convinced the species are only allied, not identical. The position of the eye at once separates our fossil from J/. Davisi ; these two hardly ever occur together, J/7. Davisiz requiring, to all appearance, a purer element than the more common 17. Bowmanni, which could live on mud, sand, gravel, or any kind of sea-bottom. It, however, seems to have preferred a calcareous sea-bed when it could get it. Localities. —Luanpuito Fiae, or Lower Bala, rare. Knockdolian, Ayrshire (Woodw. Mus.)? Everywhere in Caravoc or Bata Rocks, N. and 8. Wales, Westmoreland; S. Scotland; North, East, West, and South Ireland. A few localities may be given: Bala, abundant, especially east of the lake (7. Davisiz, west and north); Dinas Mowddwy ; Llanfyllin; Llanfairynghornwy, Anglesea; N. W. of Llandeilo; Shoal’s Hook, &c., in ! That is, reflected closely for its anterior half upon the upper crust ; most of the species have it convex, i. e., concave upon the cast. Probably the difference is due to greater flexibility in the membranous fold. ILLANUS. 187 Pembrokeshire. In Ireland:—Tyrone; Portrane, Dublin; Chair of Kildare; Wexford ; &c. Lianpovery Rocks, Girvan, Ayrshire, abundant; Builth; Llandovery ; Haver- fordwest (with Ji. Thomsoni), and other localities in 8. Wales. Kilbride, Co. Galway (Sir R. Griffith). May Hira Sanpsrons, Shropshire, rarely, viz.—Norbury, Pl. XXVIII, f. 6; Chirbury. Also in the Purple (‘'Tarannon’) shales of the Onny River, Shropshire (Cabinet of the late H. Wyatt-Edgell, Esq.). Our figures are chiefly from the Museum Pract. Geology. The species never occurs in Wenlock rocks, and but rarely so high as May Hill Sandstone. Mr. Wyatt-Edgell’s cabinet contains a caudal shield, clearly intermediate in form between Jl. Bowmanni and our next species, which must be regarded therefore as a subspecies only. We shall term it /7. emulus :-— Subspecies I. InLanvus (DysPLANUS) ZMULUS, n. sp. Pl. XXVIII, fig. 5. Il. (D.) modicus, forsan triuncis, depressus, superficie imbricatd, caudé (cetera non adhue inventa sunt) lata. Long. caude \6 lin., lat. 2 une. Cauda semicirculata, anté subrecta (angulis trupcatis exceptis), posticé aquabiliter rotundata. Axis dimidium caude via efficiens, brevis ; sulcis axalibus latis convergentibus, ad marginem superiorem profundis latisque. Annuli in axe antico 5-6, inconspicui, arcuati. Latera sulcis 3-4 brevibus et radiantibus distincta, quorum supernum latus profundius. Fulcra ab axe dimidium latitudinis ejus distantia. Anguli truncati, facie externa curv. Margo valde deflecus. Fascia lata. A single caudal shield or two only of this remarkably fine fossil have yet occurred. They are from that as yet little known formation, the May Hill Sandstone, and are in the collection of Silurian fossils in Jermyn Street. Collectors should search for the head and body-rings, which probably would indicate a short obtuse species, depressed above, but con- vex on the borders. It can only at present be regarded as a subspecies of the preceding. Tail 2 inches wide, and 1 inch 4 lines long ; semicircular, convex on the steep sides and depressed above. ‘The anterior border is rather straight. The axis is broad above, defined there by wide axal depressions, and not quite equal in width to half that of the front margin; from thence greatly converging shallow axal furrows reach one third down the tail. The axis is, however, really extended further, and is faintly indicated as far as nearly half-down the tail; it forms nearly an equilateral triangle—our figure does not show this quite correctly. Faint arched rings, five or six in number, ornament the upper part, and seem to run almost continuously into the strong squamate ,-shaped plicee which ornament the surface. These are stronger, sharper, and more remote than im any species with which [ am familiar. The sides show a remote fulcrum, placed at about half the width of the axis away from it, and thence a suddenly recurved facet, which is convex outwards, while 188 SILURIAN TRILOBITES. in most species it is nearly flat. The angles are thus truncated considerably ; and this gives this rare species much the look of the ordinary J/. Bowmannc, figured in the same Plate, fig. 7. The sides are moreover radiated by 4 short furrows ; of which, as usual, the uppermost, subtending the fulcrum, is broad and strong ; the second fainter, and the rest obscure. ‘These furrows do not reach above half across the sides, which are gently convex only above, and then slightly decurved. Our figured specimen is a perfect internal cast in arenaceous limestone, and therefore, not being broken, conceals the fascia entirely. But a Presteign specimen, in the ‘ Mus. P. Geology,’ shows a broadish fascca with remote striae. The ornament of the surface is very remarkable, as above noticed. Strong, arched, or rather bent striz, which run up obliquely from the sides towards the axis, mcsculating as they go in rather an unusual manner. They keep clear of the deflexed margin, and do not cover the upper half of the sides, but reach the lower half of the short axis, and seem to be continuous with its obscure arched furrows, indicating the many axal rings. Where they meet from either side they take a j-shaped form, something like the ornament on Lucina divaricata and many species of Pecten. Localities —May Hitt Sanpstone of Upper Snead, near Chirbury, Shropshire. Also Presteign, Radnorshire. (Coll. by Mr. J. E. Davis: both specimens are in the Mus. Pract. Geol.) Inzznus (DyspLanus) Tuomson1, Salfer. Pl. XXVIII, figs. 2—4; Pl. XXX, figs. 8—10. InLanus (DyspL.) THomsont, Salter. Quart. Geol. Journ., vol. vil, p. 171, pl. ix, fiz. 3, 1851. = oe — Id. Siluria, 3rd ed., Appendix, 1867. = — — Id. Mem. Geol. Surv., vol. iii, p. 360, as I/lenopsis, in p. 231, 1866. ~ Il. (D.) maximus, 6 uncias longus, 3; latus, levis ; capite lenté convexo, caudam semi- ellipticam vix superante, thoracem valde trilobum hac superante. Oculi modici, haud distantes, longitudinem eorum a margine postico distantes. Anguli rotundati? Gene parve. Thoracis longitudo = capitis efficit, annulis 9 ;\ axis ejus valdé convecus pleuris latior est. Pleure fulcro tenus (hdc postice ad dimidium posito) plane, dein abrupte declives et reflexe. Cauda lenté conveva, axe magno tantum inter foveas conspicuo, sulcis omnino obsoletis. Latera abrupte lateque truncata. Fascia latissima concava, striis raris conspicuis. There is a close general resemblance in this bulky Llandovery species to the more common J/. Bowmanni. I have therefore contrasted the diagnoses minutely, and beg the 1 I think I am not mistaken in this number. We have two perfect specimens, but in both the rings have somewhat slipped over each other. The relation of the species to I/. Bowmanni is so close in many respects, that it can hardly be other than a Dysplanus. ILLANUS. 189 patience of classical readers for their unwieldy length. 7. Bowmanai has the greater range, for our fossil is confined to the Llandovery and May Hill rocks; but in the former the two species frequently occur together, and their differences then become manifest enough. ‘The larger form has much less remote and less backward eyes, a stronger trilobation, and a more tapering shape in the axis of the thorax ; the pleure are more abruptly bent backward; and the tail longer in proportion to the width. It needs close examination to detect these proportional differences in the J//eui ; but the habit and aspect would be alone sufficient, for Z7. Thomsoni is very much less convex, the thorax much longer, &c. ‘These differences will appear more fully in the course of description. A large oblong species, not less than six inches by three inches and a quarter! Rounded, but not obtuse, at either end; regularly convex, not at all gibbous; and with the thorax strongly trilobed, the semioval head faintly so, and the tail scarcely at all trilobate. The head appears to be scarcely at all longer than the tail, but both are longer by one third than the thorax. The fine specimen in Pl. XXX, figured from Prof. Wyville Thomson’s Cabinet, shows these proportions. Head only gently convex, and divided pretty equally into glabella and cheeks by long straight axal furrows, faint on the outside, but strong in the cast, with a pair of ovate- lanceolate glands.’ The cheeks outside the facial suture are narrow and abruptly depressed, but are level from the glabella to the eyes, the latter bemg large and promi- nent, and placed at about two thirds the glabella’s width away from it; they are fully their own length from the hinder margin, and being larger than in J7. Bowmanazi, of course appear further forwards than in that species. ‘The sculpture of the head, so far as seen, consists only of short broken arched lines and a few puncta, except over the front, where larger and more remote lines occur at rare intervals. We do not know the actual front margin. Thorax of nine broad rings, greatly arched forwards on the axis, which even poste- riorly is wider than the pleure, and greatly so in front; it is divided from these by strong axal furrows. ‘The pleure rise a little as they leave the axis, and are gently convex rather than flat’ towards the fulcrum, placed at less than half out in the hinder rings, and at one third in front. Thence they bend strongly downward and backward, and are a good deal thickened, as shown in the cast (Pl. XXVIII, fig. 2). The tips are blunt- pointed, not at all truncate as in fig. 7 (Z/. Bowmanni). Tail long, semioval, except for the strong re-entering curves and angles of the 1 I can only suppose these oval spaces, frequently punctate-granulate, to represent one pair of the curious gland-like markings which occur on so many segments of the head, body, and caudal axis in various genera (p. 50, &c.). Prof. W. Thomson does not believe them glands; what are they? 2 [llenus has apparently ungrooved pleurz in all the species. These specimens show the meaning of this; for the true position of the groove, which, distinct or not, exists in all Trilobites, is here quite at the hinder edge of the pleura, and is visible internally in the two front rings. 190 SILURIAN TRILOBITES. front edge. It is as broad as long, shghtly and very evenly convex all over, the broad axal lobe being marked out in front by shallow depressions only, but no trace of axal furrows, however short. The sides, too, show scarce a trace of the usual strong upper groove—so conspicuous in most species. The greatest convexity is about the middle of the caudal shield, and the edge is neither obtuse nor recurved. ‘The front margin of the tail is unusually sinuous. The front edge of the axis is greatly arched forwards; the fulcral point rectangular, and the outer angles widely truncate, so that from the fulerum the edge is almost vertically cut off. The fascza, narrow and convex at the outer angles, becomes very wide and quite concave (2. e. conver im the cast) round the posterior border, and is coarsely striate. Localities —Luanpovery Rocxs. Abundant in the hght-coloured sandstones of Mullock, Girvan Water, Ayrshire (Mus. Pract. Geology and of Prof. Wyville Thomson). Also the species is common at Haverfordwest, Pembrokeshire (Museum of the late H. Wyatt-Edgell, and of Mr. Lightbody). May Hi11 Sanpstoyz, Presteign: Builth : and Pen-y-lan, Llandovery; S. Wales. Tarannon Suate: Onny River, Shropshire © (Mus. Pract. Geol.). Subspecies LI. ILLa&NuS NEXILIS. Pl. XXX, figs. 4, 5. This fossil appears to be intermediate between the ordinary J/. Bowmanni and our next species J/. Thomsoni, which is evidently distinct. I cannot be so sure about the. present one, which, while intermediate in form, possesses some characters not common to either species. It has the aspect of Z/. Zhomsoni, the even contour of tail, and arched convex axis of the thorax, but not the abruptly reflexed pleurze or long truncate angles to the tail of that species. The position of the eye and the convexity of the head are like those of J/. Bowmanni ; but it differs from that species—by having no trace of the narrow neck-furrow so conspicuous in the Caradoc fossil; and by having a thickened line of apophyses below the axal furrows of the longer thorax, which thickened ridge produces a broad and very definite axal furrow in the cast ; this is absent in J//. Bowmanni. Again, the tail is longer; the front margin of its axal portion arched, not truncate ; the upper lateral furrows all but obsolete ; the fulcrum closer in; and the facet much more oblique, thus truncating the angle very slightly. And the fascia, which first drew my attention to this marked subspecies, differs entirely from that of Z/. Bowmanni, and is not quite like J/. Thomsoni. 1 have only seen three specimens, all from the same locality, one of which is a caudal shield, showing the considerable size of the species. Elliptical, 4 inches long, of which the large semioval tail forms nearly one half, while the very convex (not gibbous) head is about one third longer than the strongly trilobed thorax of nine rings. ILLANUS. 191 _ The head forms a regular quarter of a sphere, and is very equally and highly convex ; it is marked for one third up by axal furrows, which first converge a little, and then turn outward above the oval gland. Lye distant from the glabella about half the width of the latter, of moderate size, and placed at less than its own length apart from the neck margin. Cheeks broad, with rounded angles—the facial line divergent above the eye. No neck-furrow, even in the cast. Thorax with its axis nearly parallel-sided, a good deal wider than the pleure, and very convex, separated (in the cast, at least) by a broad, flat-bottomed furrow; the pleure convex thence as far as the fulcrum, which is placed at one third out in all the rings; the pleuree bent down and a good deal backwards from the fulcral poimt; the ends pointed, and curved backward (they are straight in J/7. Bowmanni). The tail a long half-oval, broader than long, and not obtuse at the tip; the front margin uneven, divided into a broad axal lobe much arched forward, which is distinctly marked out by axal pits, but no axal furrows. ‘Thence to the fulcrum the margin is straight, and beyond it a wide oblique truncation, with the edge of the facet vertical. No axal furrows or depressions interrupt the smooth contour, except at the extreme front margin. Our figured specimen shows (the cast being broken) a very broad and remarkably bent fascia beneath, extending near half-way up the tail, and divided into two very distinct portions. The outer part is narrower and only slightly concave round the hinder margin Fie. 48. (Fig. 48 a) ; but at the upper angles (in Fig. 48 6) this part becomes first flat, and then strongly con- Z Py cave; and thence bends upwards, with a sharp angle (making a deep furrow on the cast) between it and the inner half of the fascia. This zaner b portion is then reflected closely beneath the upper hs : ~ surface, and follows it. The squamous lines which cover the mner half are wide apart ; those Section of the tail, with its incurved fascia: a, = c longitudinal section; 4, transverse section on the marginal portion closer together. Round across Higfaceta (4%): the extreme edge the fascia forms a convex fillet, so that the section of the whole fascia, very perfect in this specimen, would be somewhat like our figure 48. The variations of the caudal fascia deserve close study; but the ‘details of its shape are better understood by a figure than description ; a circumstance not at all uncommon in natural-history illustration. Locality —Luanpovery schists of Mullock, Girvan, Ayrshire (Prof. Thomson’s and Mr. Wyatt-Edgell’s cabinets). 192 SILURIAN TRILOBITES. Subgenus 4—\..2Nvs proper. Innznvs (It.) Batty, n. sp. Pl. XXVIII, fig. 14. Compare with ILLanvs crassicauDa, Wahlenberg. Nova Acta Reg. Soc. Sci. Upsal., vol. viii, p. 27, tab. ii, figs. 5, 6, 1821—not of Portlock nor M‘Coy. a also with InLanus Datmant, Volborth. Mém. Acad. Imp. Sc. Petersb., vol. vi, No. 2, p. 13, tab. ii, figs. 7—13. Il. erassicauda, Dalm. et Auctorum, fide Volborth, 1863. Ill. (I1.) magnus, 4 uncias longus, 23 latus, ellipticus, obtusissimus, profunde trilobus ; caput gibbum multim caudd planiore majus, oculis distantibus retrorsis ; angulisque rotundatis; thorar cauddé brevior. Caput transversum valdé converum, vir gibbum, glabellé angustd, sulcis azxalibus brevibus tertias capitis efficientibus. Gene abrupte declives. Oculi modici eminentes, longé a glabella positi, et dimidium longitudinis eorum a margine postico distantes. Axis corporis converus, parallelus, pleuris viz latior : his fulcro tenus (ad dimidium posito) planis, dein valdé deflexis, paullé (posticis precipue) recurvis. Cauda semicirculata (angulis obliqué truncatis), subplana seu lente convexa, axe Jato, inter foveas latas tantuim conspicuo, sulcis azxalibus nullis: margo acutus, nec re- curvus. I have purposely confined the diagnosis and description to our single British speci- men. It may, indeed, possibly prove identical with the common Scandinavian form above quoted. But it is much larger than J/. crassicauda, at least if the specimens which reach England are fair samples of that species. (I have here figured J/. crassicauda and its ally Z/. Dalmani, for comparison.) And while in the position and size of the Fie. 49. Fie. 50. Internal cast of I/lenus crassicauda, Wahl. Ilenus Dalmani, Volb. (After Volborth), Lower Silurian, North Russia. *. showing alimentary canal (full of a. The caudal fascia, seen when the surface of the cast is broken away. ingested matter ?), from Volborth.! é. Interior of cast, showing lobes (attachments of muscles ?). 2 Volborth ‘On the Smooth-tailed Russian Trilobites,’ ‘Mém. Imp. Acad. Sc. Petersburg,’ 7th ser., tom. vi, No. 2, 1863. From this important and philosophical memoir our woodcuts illustrative of the structure are all taken. Dr. Volborth discusses all the accessible points of the anatomy of Illenus. He regards the internal tube (fig. 49) as the dorsal heart, comparing it with that of Apus cancriformis. I trust 1 am not presumptuous in supposing that the viscus represented by Dr. Volborth as a heart or ILLAINUS. 193 eye, the convexity of the head between the eyes, and the proportionally longer tail-piece, our fossil differs from the ordinary J/. crassicauda. A nearer approach is made in these respects to Dr. Volborth’s new variety or species J/. (erass.) Dalmani, Volb. ; but I will not unite it with that form, which has larger eyes, nearer the glabella—a longer head, and squarer head-angles. The species is so near to these two Russian forms, that I give a woodcut of both, more especially for the purpose of showing the structural points gained for us by the acumen of Dr. Volborth, in the work cited in the foot-note. We have but one specimen, rolled up, of this fine species, for the use of which I am in- debted to the Irish Geol. Survey. At first sight it was naturally taken for 7/7. Bowmanni, the common Lower Silurian form ; and it occurs in beds of the same age. To that species, too, it bears much resemblance in the shape of the head, position of the eyes, and the general aspect. But it is a true /enus, with 10 rmgs—not a Dysplanus ; and its alliance is with the Swedish forms of J/. crassicauda, Wahl., and 7/7. Dalmani of Volborth. J7. crassicauda has been often quoted from Britain, but always erroneously ; whether this may be an extreme variety of that northern species, uniting the above-mentioned forms, I am not quite sure; but I shall try to point out its proportional differences, which are nearly all the characters we have to rely on; at least, in the great majority of the species of this very uniform genus. | Our coiled-up specimen, with the crust preserved, measures rather more than three inches in breadth, and when uncoiled must have been four inches long. Of this length the large semicircular head, more than a quarter of a sphere in convexity, is two and three quarter inches long, obtuse in form, but regularly convex, and three inches broad. The glabella occupies less than a third of this breadth, and is defined only by short axal furrows, strongest behind, which do not reach one third up the head. The prominent eye is placed as far from the glabella as the width of the latter, and very close to the hinder margin—not its own length from it. The facial suture beneath it turns sharply outward. In front of the eye its course is not known. ‘The cheeks slope gradually down, not abruptly, and are greatly rounded off at the angles—more so than in kindred species. The chief convexity of the head is more than midway up—not near the vertex as in I7. crassicauda, which, seen from above, has a shorter head and less rounded angles (Volborth, 1. c., pl. 1). The thorax is much shorter than the head, and rather shorter than the tail, the pro- portions of the three being nearly as 4: 2}: 8. This may probably vary in some indi- viduals, and is sure to be different in younger specimens, which would have the tail shorter. dorsal vessel (see woodcut 49) must be the cast of an annulated or saccate intestine. It seems to me all but impossible that the contents of the heart should be preserved in a solid state ; but the ixgesta may easily be so, if I am right in supposing the food to be silty matter. 1 A precise English term conveying this idea—parallel to the terms spherical, hemispherical— is wanted. Will any Greek scholar supply it? Tetartospherical is a long word to use, and I hate verba sesquipedalia ; still, we require a term for a shape very common in the carapaces of Crustacea. 25 194 SILURIAN TRILOBITES. The axis of the thorax is regularly convex ; it is divided from the pleura, which are narrower by one fourth than the axis, by straight and parallel furrows, sharp but not deep, and continued a very little way into the tail. ‘The fulcral points are placed rather more than one third out, and at nearly equal distance in all the rmgs; and the pleure are thence curved, rather than bent downward, and turn but little backward except in the front rings. The tips seem to be squarish or obtuse, and are not recurved. Tail semicircular, not much sinuated on the front border, the broad axis being scarcely arched forward; and the facet beyond the fulcrum, following the line of the pleurze, forms a very obtuse angle with the straight portion (not abruptly cutting off the angle, as in many species,—J//. Ziomsont, for instance). The general convexity is slight and very regular, the border not being abruptly decurved ; and the axis is obscure, except for the broad obtuse depressions on the front border ; it does not form any axal lobe. Comparing this form with the typical J7. crassicauda, as given by Volborth, we find the head less gibbous, and more generally convex ; the eyes smaller, and placed further ont ; the fulcra of the pleure at nearly equal distance from the axis in all the rings; and the tail proportionately longer, with the axis indistinct, except quite in front. Some of these differences become resemblances when we compare this form with Il. Dalmani, which Volborth has critically distinguished. But the head of that species is less convex than ours, and longer too—semi-elliptical rather than semicircular. The transverse section of a rolled specimen of that species is more obtuse than in ours, and less pointed at the ends. The cheeks bend more steeply down. The tail is longer than in the British specimens, and has the axis well marked out, &c. I cannot think, therefore, I shall be wrong in distinguishing our fossil by the name of W. H. Baily, Esq., whose useful work as Palzontologist to the Insh Survey deserves full recognition. Mr. Baily has sent me several undescribed forms, which will be referred to under their proper genera. Locality—Caravoc or Bata. Dunabrattin Head, Waterford. (Maus. Irish Geol. Survey, Dublin.) Intanvs (Iuu.) Davisu, Salter. Pl. XXIX, figs. 10O—16. ILLAHNUS CRASSICAUDA, Sharpe. Quart. Geol. Journ., vol. iv, p. 149, 1848. — Davis, Salter. Decades Geol. Survey, No. 2, pl. ii, 1849. — — M‘Coy. Synopsis Woodw. Fossils, p. 171, pl. iG, fig. 36, 1852. _ — Salter. Ibid., Appendix, p. iv, 1852. — — Id. — Morris’s Catal., 2nd edit., p. 110, 1854. ~~ — Id. Siluria, Ist edit., woodeut 29, fig. 2, 1854; 2nd edit., p. 223, Foss, 44, fig. 2, 1859. —_ — Td. Catalogue Mus. Geol. Survey, pp. 5, 19, 1865. — = Id. Memoirs Geol. Surv., vol. iii, pl. xviii, fig. 9, p. 317, 1865. ILLANUS. 195 Il. (I1.) minor, 23 uncias longus, ellipticus, obtusus, convexus, bené trilobus ; capite et pygidio ejusdem magnitudinis feré, oculis parvis approximatis. Caput semiovatum, converum nec gibbum, glabellé angustd sulcis aralibus brevibus convergentibus. Gene declives, angulis quadratis. Oculi parvi, elongati, glabelle propinqui, d basi capitis diametrum eorum distantes. Thorax mints convexus, fusiformis, sulcis axalibus minimé profundis. Pleure fulcro axi propinque, recta, anguste. Cauda semicirculata feré, margine antico vie sinuato, anguls vie truncatis ; axe lato, inter sulcos latos (in pullo conspicuos) paul- lulum elevato ; margine deflexo. Fascia lata, striis crebris. One of the many peculiar fossils which abound in the more argillaceous parts of the Bala Limestone, but which give place to others directly the matrix becomes sandy. A list of such species is given in the third volume of the Memoirs of the Survey, quoted above.’ This difference led Prof. Sedgwick and myself, in 1844, to believe there were two bands of limestone; but the researches of the Geological Survey have shown that there is but one principal band. Indeed, the calcareous bed called the Bala Limestone is continuous, or at least intermittent, over something hike 4000 square miles. From Kildare, in Ireland, to the Grug limestone’ at Llandeilo, in South Wales, in one direction ; thence to Bala, in North Wales; at Horderly, in Shropshire; as the Coniston band in Westmoreland; in Ayr, Peebles, and probably through all the Western High- lands, this remarkable band of limestone ranges, and keeps the same fossils throughout, with mere local variations, such as I have just noticed: and, perhaps, there is no species of Trilobite so characteristic of this band (it is not the most abundant) as J//enus Davisii. Il. Bowmanni nearly everywhere accompanies it, but that species has a wider range, and seems to have been necessarily less confined to one kind of sea-bottom. ‘The reader will pardon this digression for the sake of the facts ; the Bala Limestone being the key to the geology of the Lower Silurian (Middle Bala group, Sedgwick). Tl. Davisti is a small species, seldom more than two or two and a half inches long, convex, but not gibbous, well trilobed, but not with deep axal furrows, and with the margin rather suddenly bent down. The eyes are forward and approximate, as com- ' I may, perhaps, not have so good an opportunity of showing this change which takes place in one and the same bed of limestone, at a distance of certainly not two miles. Where the Bala Limestone has a muddy matrix the Trilobites are as in the first column: where it is sandy, the other group is conspicuous. Argillaceous Bala Limestone. Arenaceous Bala Limestone. Trinucleus seticornis. Trinucleus concentricus. Illenus Davisii. Illenus Bowmanni. Cheirurus bimucronatus. Phacops apiculatus. Asaphus radiatus. Asaphus Powisii. Agnostus trinodus. Calymene senaria Ampyx tumidus. (Beyrichia complicata). The shells follow the same rule, but less strictly. —J. W.S., 1853; ‘Mem. Geol. Surv.,’ vol. iii, p. 273. 2 This Grug limestone is often confounded with the Llandeilo limestone: it is brought close to it by faults, but has quite different fossils. 196 SILURIAN TRILOBITES. pared with Z/. Bowmanni and its allies; but this is a true genus, and does not need comparison with that species. I give the description, revised, from ‘ Decade 2.’ General form oval ; length to width, as 17: 10; the semioval head and semicircular tail nearly equal in length ; the thorax about two thirds the length of either, and strongly, but not deeply, trilobate. The axal furrows are carried less than half way up the head, and but a little way down the tail (except in young specimens, fig. 16). Head more depressed than a quarter of a sphere, and regularly convex, not gibbous behind (our fig. 13 is too much depressed, being crushed a little). It is divided into three nearly equal parts by the short and slightly converging axal furrows, which turn out again, and then cease at about the level of the top of the eye. The latter is of moderate size, gently lunate and narrow, bounded beneath by a slight furrow, and placed fully its own length from the posterior margin, which shows no trace of a neck-furrow, within or without the crust. The facial suture is divergent above the eye, and slightly so below it, so as to cut the margin beneath the most prominent curve of that organ. The rostral shield (fig. 14) is shuttle-shaped, more than twice as wide as long, and produced into an angle below, where the labrum, which we do not yet know, would fit to it. Thorax of ten narrow segments, the axis well marked, gently convex, and subfusi- form; wider than the pleure in the forward segments, in the last only equal to them. The fulcrum is very near the axis in the first segment, and in the last placed scarcely more than a third along the pleure, which have a distinct facet and oblique ends. The front pleure bend down and a little back; the hinder ones are straight, only bent downward. Tail semicircular and moderately convex, chiefly so toward the margin, which descends abruptly, but rather flattened along the anterior two thirds. The axis is indistinctly marked out by two deep impressions, which sometimes form short, rapidly converging furrows ; the upper corners are bent sharply down beyond the fulcrum, in order to pass freely under the thorax-rings in rolling, but are not truncated as in many species; so that the outline of the tail is tolerably semicircular, and straighter in front than in many forms of the genus. The fascia is of even width all round, and not very broad ; it is rather finely striate. The tail, too, has oblique ornamental lines round the margin. In the tail of young specimens the axis is marked out nearly all round (fig. 16), and extends three-fifths down the tail, which is also flatter. Var. B, Involutus.—‘ Decade 2, Geol. Survey,’ pl. ii, fig. 8. The axis in some specimens is so much narrower, and the tail-margin so much more incurved, that the specimens possessing these characters might well pass for examples of a new species. The axis is truly very narrow, and the fulerum more remote, as usual in all such cases. I find the same form in Dr. Wyville Thomson’s Cabinet, from the Ayrshire district, and note it under a varietal name, not much doubting that, when we know the perfect form, we shall find this variety a true species, or, at least, one of those constant forms which botanists call swd-species,—a very useful term. seis! ILLANUS. 197 Comparing other species of the same sub-genus with ours, we find that ZZ. crassicauda is not only a much more convex form, but has the head rather gibbous behind ; the eyes more remote and further back; the tail scarcely longer than the thorax, the latter having the fulcrum more remote in the front rings, and placed halfway out in the hinder ones ; the incurved under portion or fascia (for example see fig. 50) far broader and less concave (2. e. less reflected), and the surface sculptured by strong sharp lines; these lines are certainly not conspicuous in J/. Davisi?, though the latter is not quite smooth. From J/. Portlockii its much greater convexity and the approximate eyes readily distinguish it. ‘The semicircular, not long tail, and oblique pleural tips distinguish it from the species we have named J/. Rosenbergii. Il. Murchisoni does not need com- parison ; and the position of the eyes will at once separate our neat regularly convex fossil from the Z/. Baily. I hardly know any species that has better characters of habit ; and it is rather strange it should ever have been confounded with the Swedish forms. Localities —Caravoc or Bata limestone and slate, west and north of Bala Lake, at Rhiwlas chiefly ; also Pont-y-Glyn, Diffwys, Corwen, and other intermediate places ; Llanwddyn, Montgomeryshire. (Mus. P. Geol. and Woodwardian Mus.) In Scotland,—the Wrae limestone ; and at Biggar, Peeblesshire. (Mus. P. Geol.) ILLANUS Porrtockn, Salter. Pl. XXVI, figs. 3, 4. ILLENUS crassicauDa, Portlock. Geol. Rep. Tyrone, &., pl. x, figs. 7, 8, 1843. — PortLockit, Salter. Decades Geol. Surv., 2, pl. ii, p. 3, 1849. — -— Id. Siluria, 2nd edit., Appendix, p. 539, 1859. — — Td. Morris’s Catal., 2nd ed., p. 110, 1854. a — Id. ‘Catal. Mus. Pract. Geol., p. 5, 1865. Ll. (Ill.) modicus, 24 uncias longus, laté ovatus, depressus, thorace cauddque ejusdem longitudinis fere. Caput conveaum (in juniore) glabelld angusté, sulcis axalibus brevibus ; oculis distantibus posticis. Thoracis axis pleuris longé latior est, his fulcro tenus planis, dein subito valdeque reflexis, deflexis fulcro distante. Cauda planata, transversa, oblonga, subquadrata, angulis externis longé truncatis; axe magno trientem caude efficiente et ultra, sulcis awalibus subparallelis. Fascia lata concava. A species well figured in Gen. Portlock’s very unfortunate plates ; but he referred it, apparently without much consideration, to the Z//enus crassicauda of Dalman, from which it differs in every particular except the number of body-rings, a sub-generic character. It is of a flattened shape, with short wide triangular tail, and with pleura more abruptly bent down than in any other species. /. Pordlockii is, perhaps, one of the most distinct of the British Jeni. It is only yet known in one locality, the famous Caradoc schists of Desertcreat parish, Co. Tyrone; a spot rendered classic by Portlock’s excellent work. 198 SILURIAN TRILOBITES. The species must have been fully two and a half inches long, by nineteen lines wide ; broad ovate, depressed. The thorax is nearly as long as the tail, which is wide and very short, and has the angles broadly and strongly truncate. Our smaller specimen has only a very imperfect head, which is very convex, probably even gibbous about the base of the distinct glabella; the axal furrows are broad, short, and rather deep: the eyes remote, placed near the posterior margin, apparently close to it, and so far apart as to be more than half the width of the glabella remote from it. Head-angles (probably) obtuse. . Thorax of ten rings, depressed; the axis considerably wider than the pleure, and strongly, not deeply, divided from them, scarcely tapering backwards, but more so in the young than the adult. Pleuree flat as far as the fulcrum, which is placed far outwards, at about halfway out in all the rings ; in the first rings nearly as far outwards as in the hinder ones, a character by no means common. Beyond the fulcrum the pleure are abruptly bent downwards, and very much backwards, almost at a right angle to the line of the pleure ; indeed, more so than in any British species, except, perhaps, Z/. Thomsont. Tail quadrate transverse, the posterior margin elliptical, the front edge slightly sinuated by the arch of the axis,—and with the angles so abruptly truncated beyond the fulcrum as to give an oblong instead of a semicircular shape to the tail. The axis is broader than one third of the width of the tail, marked out by short and rather strong sub-parallel furrows, which reach one third down the tail and are then lost,—at least upon the upper surface. Beneath the crust the anal extremity of the axis is prominent, and forms a narrow sulcus in the cast (fig. 3). This reaches nearly to the margin, and probably indents the broad concave fascia; but our specimen is not quite complete enough to show this. The fascia, however, is slightly convex near the margin, as indicated im- perfectly in our figure by a shallow furrow ; and extends halfway, or nearly so, up the tail, parallel with the upper surface ; above it ends just outside the fulcral point. Locality—Caranvoc schists of Desertcreat, Co. Tyrone. (Both specimens in Mus. P. Geology ; they are Portlock’s originals.) InLanvus (Inu. ?) ocutaris, Salter. Pl. XXIX, figs. 7, 8 (9 ?). ILLaNUs ocuLarts, Salter. Decade 2, pl. ii, p. 4, 1849. — — Id. —_ Morris’s Catal., 2nd edit., p. 110, 1854. — —_ Id. Catal. Mus. Pract. Geol., p. 5, 1865. Il. (Il. ?) minor, viv unciam latus, lente conveaus ; capite (soliim adhiie cognoto) semt- circulato, oculis longis. Caput modice conveaum, insuper depressum, margine frontali gibbo. Glabella genis angustior, sulcis avalibus incurvatis, his dimidium feré capitis efficientibus. ILLANUS. 199 Oculi longi, glabelle vicini, a cervice vir dimidium diametri eorum distantes. Gene triangulate, angulis productis nec acutis, haud spinosis. Thoracis axis pleuris viv latior, pleuris anticis defleais. Reliqua absunt. This pretty species may or may not belong to Z//enus proper. It is more depressed than other Lower Silurian forms, and the front margin is suddenly incurved. The eyes are long, not broad, and gently curved, and with the lentiferous area convex. They are placed so near to the posterior margin as to be about half their length away from it; but being of considerable size for the genus, they reach about halfway up the head. The eye-lobe is depressed, and there is no furrow under the eye itself. The glabella is less than a third the width of the head; the axal furrows, sigmoid in shape, rise up to the level of the front of the eye, and do not converge so much as our figure makes them. Our enlarged figure 8 @ is still a little further defective, as representing the eye too forward. Fine, concentric, wavy, continuous lines ornament the whole head, but are most conspicuous and coarse around the inflected front margin. Only parts of three front body-rings are present. Their axis is a little wider than the recurved pleurze, which are bent down and backwards from the approximate fulcrum, and appear to have rather an attenuated form and oblique apices. They are longi- tudinally striate. It is with some doubt that I add fig. 9 to this species; it has a proportionately still larger eye, and a squarer cheek-angle, not so much produced as in the small form. But these may be characters due to age, and there is no other species to compare either with ; so I leave it. It is worth figuring, at all events. Locality—Caravoc or Bara Limestone, Chair of Kildare, Kildare; quoted as Llandeilo in the ‘Decade,’ as the Bala Limestone was formerly not known to be the exact equivalent of the Caradoc, but supposed to be the Llandeilo Limestone, until the fossils disproved it. (Mus. P. Gzotoey. Only these two specimens are known to me.) ItL2nus Rosenserci, Hichwald. Pl. XXIX, figs. 2—6. Intanus Rosensercu, Fichwald, Geogn. Zool. per Ingriam, Tril. Obs., &e., t. iii, fig. 3 (7), 1833. = — Salter. Mem. Geol. Surv., vol. ii, part 1, p. 338 (not plate), 1849. = _ M‘Coy. Synopsis Woodw. Mus., p. 172, 1852. — Morcuisons, Salter. Id., Appendix, pl.i G, figs. 33—35 (not of Decade 2, Geol. Surv., which is the true I/. Murchisoni) : see p. 201, 1852. Ul. (I.) 4—5 uncias longus, gibbus, intis granuloso-striatus, capite valde convexo longitudine caudam rotundatam superante, thorace longo. Caput semiovatum, CONVELISS1- mum, fronte gibba impendente, sulcis modicis subrectis, tertias longitudinis capitis eficienti- bus. Gene majores verticales. Oculi minores, haud distantes, dé glabellé dimidio lati- 200 SILURIAN TRILOBITES. a4 tudinis ejus via sejuncti; ad margine postico distantiores. Anguli —%2 Thorax capite longior, € annulis 10 latis confectus, quorum axis modicus, sulci axales profundi. Fulcra prozima ; pleure recta, longitudinaliter striato-costate, apicibus truncatis. Cauda oblongo- ovata, ad mediam partem gibba, angulis truncatis, axe brevi, angusto, superné conspicuo, intis 3—4-annulato. Margo caude nequdem recurvus; fascia lata concava, striis imbricatis paucis imbricata. It is sad patchwork reconstructing this species, though we have plenty of frag- ments—heads without cheeks, a distorted but complete thorax, and several tail- pieces, all of which show a strong evanular character of the imner crust, which is exhibited by short broken lines and puncta in the cast. Even fragments show this character. The species is pretty common in the Coniston limestone; and all who know that rock know what a vast amount of cleavage and distortion the fossils have undergone. Nor are we quite certain about the name. Lichwald’s figure truly represents a Scandinavian form distinct from the common J/. crassicauda, and very much like ours, with broad thorax-rings, and the eye placed near the furrows, and rather forward, com- pared with such species as L/. Bowmani, which occurs with it, and has no granular surface. But in the ‘Memoirs Geol. Survey,’ vol. ii, pt. 1, when describing this species which I had already distinguished and figured for Prof. Sedgwick’s book (the figures quoted are drawn by me), I unfortunately included with it and figured for it the J. Murchisoni described at p. 201. I gave it the same name in the Appendix to the ‘ Woodwardian Synopsis’ above quoted, and thereby vitiated both descriptions. I must, therefore, go over the ground again, as we usually have to do when in a hurry; the Coniston limestone species is the one intended, and should it prove distinct, as I think it will, from Eichwald’s fossil (which seems not to have occurred to Prof. Angelin in his Swedish collections), I propose to name this conspicuous Westmoreland fossil 7/7. Warshalli, after the gentleman who has done so much to help forward the study of the Westmoreland fossils. It is larger than 7/7. Bowmani, and nearer five than four inches long; of a lengthened shape, both the head and tail semioval, with blunt extremities ; gibbous, especially in front ; deeply trilobate, and marked all over the cast with short wavy impressed lines and puncta. The glabella-furrows are more direct, longer, and converge more than in Il. Bowmani (we need not compare it with ZZ. Murchisoni, with which I formerly con- founded it). The shape of the head is not very clear, but it is nearly as long as wide, very gibbous forwards, and overhanging like that of Z/. crassicauda, which species it resembles. The glabella-furrows are sigmoid, but only slightly converging, and bent out above ; they extend forwards twice as far from the posterior margin as the place of the eyes, more than one third, but not half-way up the head (our figure has them rather too much curved). ‘The small eyes are placed about as far out from the glabella as half its width (in //. Bowmani they are two-thirds its width away), and they are placed once and a ILLANUS. 201 half their own length from the hinder margin, while in the kindred species they are only their own length in front thereof. Thorax deeply trilobate; the arched rings broad, and flat from front to back; the pleuree are equal to the axis in width, and are arched forwards instead of at all back- wards ; their fulcrum is extremely close to the axal line, seemingly about one fourth out, and from thence the pleure are covered by longitudinal lines, not very close-set ; their ends are truncate. The tail (in the figured specimen from the Woodwardian Museum) is compressed ; but it was evidently convex ; with a narrow axis, defined by broad and rather deep axal furrows, which extend, however, but a short distance, and do not much converge. The axis shows four annulations within the crust (our figure has too many). The sides slope evenly down to the thickened margin, which is not at all flattened or recurved; and the internal fascia is concave, broad, and coarsely and remotely striated with imbricate sculptured lines. I have described the original specimen, but believe the caudal shield fig. 5, which does not show the axis ribbed, to be the same, and to show the true form of the tail. Locality —Coniston ; Sunny Brow; and Horton in Ribblesdale, Westmoreland. In Carapoc or Bata Limestone (figs. 2, 4, Woodw. Mus.) ; fig. 5, Mr. Wyatt-Edgell’s Cabinet. Tuianvs (Inu.) Murcutsont, Salter. Pl. XXVI, fig. 1, and Pl. XXX, fig. 7. Intanus RosEnBERGII, Salter. Mem. Geol. Surv., vol. ii, pt. 1, pl. v, figs. 6—8, 1848. Not of Eichwald. — Mourcuison1t, Jd. Sedgwick’s Synop. Woodw. Mus., Fasc. 1, Appendix, p- iv, 1852; description only. (Only exclude figures of Westmoreland specimens, pl. iG, figs. 33—35, which are Il. Rosenbergit.) See p. 199. — — Id. Decades Geol. Survey, No. 2, Art. ii, p. 4, 1849. Il. (Iilenus) magnus, 6-7 uncias longus, ellipsoideus, obtusus, convexissimus, capite et thorace ejusdem longitudinis, caudé vie minori. Caput pars quarta sphere est, suleis axalibus brevibus, rectis, haud ultra oculos tractis. Oculi majores, vicini, a margine postico diametrum suum distantes. Anguli capitis quadrati. Thorax longus, axe latissimo pleuris subrectis longé latiori, ad fulcrum proximo. Cauda conveaxa semicircu- lata, angulis haud truncatis, margine obtuso ; axe obscuro lato, fascia angusté. More desirous to identify the closely related forms of this genus than to multiply species, I too hastily (im 1852) united the fossil from Llandeilo that is figured in the ‘Survey Memoirs’ with one which is common in beds of the same age in Westmoreland. The latter will be found in p. 199, and I believe it to be the true J/. Rosenbergii of Eichwald. The Llandeilo species, however, is clearly distinct, as pomted out by myself in the Appendix to Prof. M‘Coy’s ‘Woodwardian Catalogue :’ and, as there are two 26 202 SILURIAN TRILOBITES. species, I must restrict the name to the fossil first figured. That was a crushed speci- men; but the finest possible examples have since been obtained from the same locality ; and my friend Mr. J. E. Lee, of Caerleon, possesses the best,—our figured specimen. Except the Barr Trilobite, which it much resembles, we have no species of equal bulk in _ Britain. It is a Bala Limestone fossil ; the Grug and Birds Hill quarries being in that rock. A large and extremely convex species, generally about six or seven inches long. ‘The form a long ellipse, the length being to the breadth as 11:5. Head about equal to the thorax, or slightly longer, and the tail a little shorter than either. The head is truly a quarter of a sphere, with square head-angles, and very slightly trilobed by shallow axal furrows, which converge but little, are sigmoid, and reach to the top of the eyes.’ The glabella thus marked out is not wider than the cheeks. The eyes are large for [Menus proper; narrow, with no furrow beneath them, and near to the axis—scarcely a third of the glabella’s width away from it. The cheeks steeply decline towards the eyes, and are thence nearly vertical to the blunt margin. The angles, though called square in the diagnosis, are more acute than a right angle, and the corner is rounded off; still the aspect is unusually square for the genus. ‘The shape of the free cheek, from the very outward curve of the facial suture above the eye, is a trapezoid; the side nearest the eye being about one half that opposite to it—viz., the margin. The convexity of the head is such that a line taken transverse to the eyes would be a semicircle, and that from vertex to front a quarter of a circle. On the underside, the coarsely striate” rostral shield (epistome) is as wide as the glabella, and is itself about twice as wide as long. It is narrowed on either side, more so than in 11. Bowmanni, and abruptly broader in the middle. And in this form it differs again from the more oval shield of J/. (Bumastus) Barriensis, between which and this species there are many points of resemblance that strike the eye at first glance. Indeed, Z/. Murchisoni leads from the true J//eni to that subgenus, as may be seen by what follows. The trilobation of the thorax is not very distinct, the axis being almost as broad as that of Bumastus, but much more pronounced than in that subgenus. The thorax of ten rings is about five sixths the length of the head. The greatest breadth of the axis is in the seventh and eighth body-rings, where it is double that of the pleure ; in the first ring, as the axis is spindle-shaped, the breadth to that of the corresponding pleura is 4: 8; in the last ring itis 3: 2. The fulcrum is placed at one third in the first ring, and at one half in the eighth, ninth, and tenth. The pleura, flat as far as the approximate fulcrum,’ thence slightly bent down, and inclining backwards. 1 Within the crust, on the cast, they show strongly the glandular? depressions opposite the eye, as in Bumastus Barriensis, but not so large. These impressions are as yet very problematical. Can they be muscular attachments P I think not. * The striee are coarsely imbricato-striate, as in JJ. Barriensis. They are parallel in front with the anterior edge, and behind with the posterior edge; in the middle, nearly direct across. ’ When the axis is broad, the fulerum must be always approximate (for mechanical reasons connected with the rolling up), except in very flat Trilobites. ILLANUS. 203 The tail is convex, but not uniformly so, the anterior part and the line of the axis generally being rather flattened. Thence, towards the margin, it is bent down abruptly. The breadth of the tail exceeds the length by about one half the latter ; the posterior margin is a semicircle, and the anterior a slightly wavy line (Pl. XXX, fig. 7), on which the broad axis is marked out by shallow indentations, and the angle at which the facet starts a very obtuse one, so that the angles of the tail are scarcely more truncated than in the “Barr Trilobite.” There are but slight indications of very shallow axal furrows, but the anterior lateral furrow of the tail beneath the fulcrum is quite distinct. The fascia is slightly convex, and has coarse strie; it is very narrow. The inner surface of the tail rough, with small points or tubercles. Locality.—Caravoc or Bara Limestone, at Grug and Birds Hill, close to Llandeilo. (Mus. P. Geol. and Mr. Lee.) Chair of Kildare (Mr. Wyatt-Edgell’s Cabinet). Bumastus follows next in order of affinity; for though technically Zctillenus and Illenopsis ave in the trilobed group, they are so different structurally, on account of the position of the eyé, that we may well believe they will form distinct genera by-and-bye. I shall not follow, therefore, the order of the numbers, but place the above-named two sub-genera last. And we now come to the highest, if not the most typical’ Jd/enz, viz. the Upper Silurian forms of Bumastus, distinguished by the great solidity and fine sculpture of the shell or crust, the convexity of the body, the full number of body- rings, largely developed eyes, &c. In this group the trilobation of the tail, all but lost in some of those above described, is altogether absent, and that of the thorax nearly so, Subgenus 5.—Bumastus, Murch., 1837. Iu.aNts (Bumastus) Barriensts, Murchison. Pl. XXVII, figs. 1—5. **A new species of Trilobite,” F. Jukes. Ann. Mag. Nat. Hist., vol. ii, p. 42, figs. 8, 9, 10, 1829. ‘Probably Isotelus,” J. De C. Sowerby, ib. p. 45. Szlliman, Amer. Journ. of Science, vol. xxiii, i, p. 203, 1833. Bumastus Barriensis, Murchison. Sil. Syst. (description, but not figures), p. 656, pl. vi bis, 1839. — — Emmerich. Dissert., p. 33, 1839. Niteus? (Bumastus) Barriensis, Burmeister. Org. Tril., p. 120, 1843. Ib., Ray edition, p. 104, 1846. 1 The highest and lowest forms of a group are not typical: there is in most natural groups a central form combining all the chief characters. At least that is my idea of type. -dsaphus is typical of the Asaphide ; it is not the highest form. * . * . ey Bay tant Bitte? xe +t . ,! - « - i mPa ta ! & i} A } 2 é 4 . - ‘ y ra ij ( : ce aie 2 4 e i ) : . su if y . he ‘hy OS ee J ae Oe x . at i t é a* feted ole ‘ . ’ ¥ ye ans a Pa a ‘ v rel 4 = ‘ yrs arth) ai 4 / « fay, wer ? bs 7 ) Basu Spiegel Be PLATE XXVII. WOOLHOPE AND WENLOCK ROCKS (UPPER SILURIAN). Figs. 1—. Illenus (Bumastus) Barriensis, Murcutison. | ee ie Ms ES Direct and side views of the fine head (Pp. 203—207.) figured in Decade 2, pl. iv, ‘Mem. Geol. Survey.’ Woolhope. (Mus. P. Geol.) It shows well the great glands (or muscle-spots ?) over the eyes, and the strong sculpture, even on the cast. r , Large head, wanting the free cheeks. Woolhope shales of Malvern Tunnel. (Dr. Grindrod’s Collection.) 2, lower figure _,, My be? Miss Jukes’ original specimen. From Barr, Staffordshire. An unequalled example, of which casts are in all museums. Woolhope limestone. ah i 4 Pe Young specimen, front view, to show flatness of head. (Dr. Grindrod’s Collection.) Malvern Tunnel. 2 2, upper figure __,, A. tr c Ks Younger still. Woolhope. (Mus. P. Geol.) 5. e " 3 Side view of young head. (Dr. Grind- rod.) Malvern Tunnel. Figs. 6, 7. Lilenus (Bumast.) insignis, Haru (Il. pomatia on plate). ; 6. a “ i Fig. 6 is Dr. Grindrod’s exquisite speci- (Pi. 207;) men from Ledbury, Herefordshire. ; WENLOCK LIMESTONE. 1 - ay : Labrum, from Dudley. (Gray’s Col- lection, British Museum.) Figs. 8, 9. Lllaenus ( Bumast.) carinatus, SauveR. From the Wenlock limestone (P. 209.) of Winnings Quarry, Malvern. (Pre- sented to the Mus. P. Geol. by the late Rev. F. Dyson.) »» » = Free cheek, eye, and broken spinous head-angle. »3 ‘9 r Upper view of head, showing carinated form of same, and the axal puncta. Rei)” “I anti) a rrr i i sido! Pa sAty Peet “7. CA i Tae ok! Ci tia 4» ADDIS CS OU art ae (ap Saal} RmGiprtvs § L9H ie 1. i aanrnd) (oi! (i? a Py ae eae i) 5p} BNA). ; As Ld oni) ) ——— Figs. 7—13. PLATE XXVIII. MIDDLE SILURIAN (LLANDOVERY AND MAY HILL ROCKS). Ilenus (Bumastus) Maccallumt, SautER. Mullock, Girvan, Ayrshire. (Mus. PeGeol) —P. 210, Tllenus (Dysplanus) Thomsoni, Sauter. P.188. Internal cast, the same figured by Murchi- son, ‘Quart. Geol. Journ.’ From Mullock, Girvan. (Mus. P. Geol., presented by Sir Roderick I. Murchison. ) Tail of ditto. Same Locality and Museum. Obscure young specimen. Purple shales (Tarannon shale) of Onny River, Shrop- shire. (Mus. P. Geol.) Illenus (Dysplanus) emulus, Sauter. May Hill sandstone of Norbury. (Mus. P. Geol.) P. 187. Tllenus (Dysplanus) Bowmanni, Sauter. Same Locality and Museum as the last. P. 185. 33 +) 3 33 33 9? LOWER SILURIAN (CARADOC). Tllaenus (Dysplanus) Bowmanni, Sauter. P.185. Half-grown. Desertcreat, Tyrone. (Mus. P. Geol.) Portlock’s original. Young. Same Locality and Museum. Young tail, very short. Shoals Hook, near Haverfordwest. (Mus. P. Geol.) Half-grown fine specimen from the Bala slates of Llanwddyn, Montgomeryshire. (Woodwardian Museum ; M‘Coy’s figured specimen of ‘ J7. centrotus.’) Variety, with longer and more connivent head-furrows. (Mus. P. Geol.) : 4 2 Outline of large head. Shoals Hook, Pembrokeshire. (Mus. P. Geol.) gs es f Young head. (Old Red ? conglomerates, derived from the) Coniston or Bala lime- stone, T'routbeck.. The species shows the attachment of the lower(mandibular?) muscles. (Mus. Wyatt-Edgell.) IMlanus (Ill.) Baily, Sautrr. Dunabrattin Head, Waterford. In lime- stone. (Mus. Irish Survey.) P. 192. adoec a « O SLLU RIAN BRR OW L \ i H Py, datas) oat Reha cnn en ee SONNET By: 1 tno tig fe a iP ‘bp aM ce ‘ eo Bacar nei ait hy pet at: hte ih RY if , es q ¥ 4 ‘ ie / ar 2 vf al ‘ . J : Pi "he ‘as 7 1 a. va a. . 7 * * Fig. 1. Figs. 2—6. Figs: /—9. 9. Figs. 10—16. 10. be 12, 13. 14. 15. 16. PLATE XXIX. LOWER SILURIAN (CARADOC). Stygina ? Musheni, Sautzr. Boulder (probably of Caradoc), from the (P. 174.) Drift, Buildwas, Shropshire. (Brit. Mus.) Menus (Ill.) Rosenbergu, Hicowaup? From the Coniston or Bala lime- (P. 199.) stone of Coniston and Troutbeck. (Except fig. 5, which is Mr. Wyatt-Edgell’s specimen, all are in the Woodwardian Museum.) Figs. 2, 3, 4, are figured in Prof. Sedgwick’s ‘Synopsis,’ and show the sculpture well. Ili. (uenus ?) ocularis, Sauter. 7, Side view of head; 8, head, nat. (P. 198.) size ; 8 a, magnified ; 8 4, sculpture enlarged. Carapoc or Bata limestone, Chair of Kildare. (Mus. P. Geol.) ce - ? A larger fragment of the side of the head, probably the same species. Same Locality and Museum. Ll. (Ilenus) Davisii, Sauter. Carapoc or Bata limestone. (P. 194.) 3 3 The finest known. Figured in the Wood- wardian ‘Synopsis’ by M‘Coy and Salter. (Woodw. Mus., Cambridge.) is ms Ordinary form at Rhiwlas, Bala. (Mus. P. Geol.) % "4 Restored figure, from Decade 2, Geol. Survey. 23 3 Epistome or rostral shield. (Mus. P. Geol.) » 4 Side view. Same locality and cabinet. > rs Young tail, from Mr. Wyatt-Edgell’s cabinet, showing a nearly complete axis. PR aS n ? f nO, Bs ah, Psat rae Le . , | aah UT jk eae s AeTiy y Vi ; PSs - c Aaa? hi Beg 3 ie | “a ; ys > SAG hianyn Tae fe: ve ipvite fie i Hin | ¥y ot a : | | ? wn planets a + SE aaa ub ie RUaT So. ty bees 5 oF priagnshiV 4! By. nest aa a) 3 nie ey a8 1 ack’ | | Lye mn Xie u's) WN) e ; | | | lest ie" 4 4 Ke ‘ Betas set Md ‘Le as a> % seal Pres el ‘ ‘ Pa PLATE XXX. LLANDOVERY ROCKS (MIDDLE SILURIAN). — Fig. 1. Tllenus (Bumastus) Barriensis, Murcuison. A solitary specimen from the Purple (Tarannon) shales of the Onny River, Shropshire. (Mr. Wyatt- Edgell’s Cabinet.) P. 203. Figs. 2, 3. Ill. (Bumastus) Maccallumi, Sauver. From the Llandovery (not the May Hill) rocks of Girvan, Ayrshire. (See also Pl. XXVIII, fig. 1.) Fig. 2, tail, full-grown ; 3, young specimen, dis-. membered., The free cheeks are yet wanting; possibly they are spinose. (Mus. Prof. Wyville Thomson.) P. 210. Figs. 4, 5. Til. (Dysplanus) newilis, Saurur. Llandovery rocks of Drummuck, near Girvan, Ayrshire. (Prof. Wyville Thom- son’s cabinet.) Figs. 4 and 5 show the broad epistome, unlike that of Il. Bowmanm. (Mr. Wyatt-Edgell’s Cabinet.) Fig. 4 shows the fascia, which is much bent in this species. P. 190. Fig. 6. Ill. (Dysplanus) Bowmanni, Sauter. Llandovery mudstone of Mullock, Girvan, Ayr. (Cabinet of Prof. Wyville Thomson.) P. 185. Figs. 8, 10. JU. (Dysplanus) Thomsoni, Sautur. Llandovery rock. P. 188. 8. : me Large intaglio in yellow sandstone, from Mullock, near Girvan, Ayrshire. (Prof. Wyville Thomson’s cabinet.) 9. _ . Side of head, showing eye and free cheek (very rarely found). The Gas Works, Haverfordwest. (Mr. Wyatt-Edgell’s Cabinet.) 10. e ms ‘Tail, from Mullock, Girvan, Ayrshire ; showing truncate angles. (Woodw. Mus.) LOWER SILURIAN. Fig. 7. LU. (Manus) Murchisoni, Sauver. Caranoc limestone of Chair of Kildare, Ireland. (Cabinet of Mr. Wyatt- Edgell.) ‘This should have been in , Pl XXVii> EOL : ~~ ~ L st 1G 1 CAME TTTEILSUS RD Joa PALMONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVII. VOLUME FOR 1866. LONDON: MDCCCLXVII, a A MONOGRAPH OF THE BRITISH FOSSIL BRACHIOPODA. PAW) VIE NO. IL CONTAINING Paces 89—168; Puares XIJI—XXII. * THE SILURIAN BRACHIOPODA. BY THOMAS DAVIDSON, F.R.S., F.G.S., VICE-PRESIDENT OF THE PALEZONTOGRAPHICAL SOCIETY ; MEMBER OF THE GEOLOGICAL SOCIETIES OF FRANCE, EDINBURGH, AND GLASGOW; MEMBRE ETRANGER DE L’ INSTITUT DES PROVINCES, FRANCE, AND LINNEAN SOCIETY OF NORMANDY ; IMPERIAL MINERALOGICAL SOCIETY OF ST. PETERSBURG ; ROYAL ACADEMIES OF BELGIUM AND OF BAVARIA ; SOCIETE ROYALE HOLLANDAISE DES SCIENCES, HARLEM; ROYAL SOCIETY OF LIEGE ; ACADEMY OF ST. LOUIS ; AMERICAN PHILOSOPHICAL SOCIETY, PHILADELPHIA ; ZOOLOGICAL SOCIETY OF VIENNA; PALZONTOGRAPHICAL SOCIETY OF BELGIUM ; HON. MEMBER OF THE DUDLEY AND MIDLAND GEOLOGICAL AND SCIENTIFIC SOCIETY, ETC. LONDON: PRINTED FOR THE PALZONTOGRAPHICAL SOCIETY. 1867. PRINTED BY J. E, ADLARD, BARTHOLOMEW CLOSE. = SPIRIFERID 2. 89 SPIRIFERA PLICATELLA, var. GLoBosA, Salter. PI. IX, figs. 7, 8. SPIRIFER PLICATELLUS, var. GLOBosUs, Salter. Mem. Geol. Surv., vol. ii, part i, ; p- 382. 1848. SPIRIFERA PLICATELLA, var. GLOBOSA, Lindstrim. Proceed. Roy. Acad. Sc. Stockholm, 1860, p. 158. The shell of this variety is, according to Mr. Salter, “about as wide, or a little wider than long; hinge-line very short ; beaks approximate; furrows none; very gibbous;” it is the variety easily connected with Spirifer radiatus, Sow. Indeed, there appears to be little by which it can be distinguished from the true Spirifera radiata, except the greater convexity or gibbosity of its valves and its finer striation. Two specimens measured— Length 20, breadth 26, depth 15 lines. See eae, ‘35 Lo, Spirifera Marklini, de Vern., is easily distinguishable from Sp. globosa by its less transverse shape, and by its great depth and square-like appearance. This variety is not rare in the Wenlock Limestone at Dudley; and it occurs also in the Island of Gothland.? Sprrirera BiyuGosa, M‘Coy. PI. X, figs. 1—3. SPrriIFER BiguGosus, M‘Coy. Synopsis Sil. Foss. Ireland, p. 36, pl. iii, fig. 23, 1846. — — Salter. Explanation of Sheets 160, 161, 171, and 172, Geol Surv. Ireland, p, 13, 1863. Spec. Char. Rotundato-quadrate, wider than long, valves more or less gibbous; hinge-line as long as the width of the shell. Dorsal valve rather less deep than the opposite one; mesial fold moderately wide; smooth, and divided along the middle by a deep hollow groove ; the remaining portions of the valve being covered with from twenty to twenty-four obtusely angular, simple ribs, the whole crossed by numerous concentric lines of growth. In the ventral valve the sinus is wide and concave, and extends from the extremity of the beak to the front ; while the lateral portions of the valves are covered with ribs, as in the opposite valve; beak incurved, area about a couple of lines wide, fissure triangular, and partly arched over by a pseudo-deltidium. A large specimen measured— Length 12, width 14 lines. 1 Herr Lindstr6m informs me that he has seen Spirifera plicatella from the Upper Silurian rocks in the neighbourhood of Christiania in Norway, accompanied by the following species—Spzrifera elevata, Meristella tumida, Atrypa reticularis, At. imbricata, Pentamerus oblongus, P. linguiferus, Rhynchonella euneata, Rh. diodonta, Rh. nucula, Rh. spherica, Rh. Wilsoni, Orthis canaliculata, O. hybrida, O. biforata, Strophomena rhomboidalis, St. pecten, Leptena transversalis, and Chonetes striatella :—a series which must, says Mr. Salter, ‘represent our May Hill Sandstone.”’ 12 90 BRITISH SILURIAN BRACHIOPODA. Obs. Prof. M‘Coy informs us that “this species is remarkable for having its mesial ridge (fold) divided in two by a mesial sulcus, in which it agrees with Spirifer bifidus, Roemer, but from which it differs in the lateral ribs being less numerous and not branched, as in that species. The mesial hollow (sinus of ventral valve) is somewhat simple, and sometimes has a slender mesial ridge. In finely preserved examples the striz of growth are regular and prominent.” I may likewise observe, that Spzrifera bijugosa bears some resemblance in shape and size to Spirifer bijugatus, Von Buch; but this last seems to possess a smaller number of ribs ; and its sinus and fold appear also to differ somewhat in shape from that of the shell under description. Prof. M‘Coy figures the dorsal valve only; and, although I have seen several specimens of both valves, no example I have met with was completely perfect. The species is not recorded in ‘Siluria, nor in Morris’s ‘ Catalogue of British Fossils.’ Position and Locality—Prof. M‘Coy states that Sp. dyugosa is very abundant in the shales of Doonquin, Dingle, County Kerry, and very common in the slates of Ferriter’s Cove, Dingle. According to the Geological Surveyors, the rocks at Dunquin,’ to a little north of Clogher Head, are equivalents of the Ludlow beds. The strata at Ferriter’s Cove, joining it to the north, and on the coast between Dunquin and Clogher Head, are coloured as ‘ Wenlock.’ The Wenlock rocks of this district (Dingle) are described on the label of the fossil cases of the Museum of the Geological Survey in Dublin as “a slaty and very fossiliferous series, with much interstratified trap.” Sp. dijugosa occurs on the north shore of Ferriter’s Cove in Wenlock rocks, with (according to Mr. Salter) “ Athyris tumida, Atrypa reticularis, Chonetes lata, Leptena transversalis, Orthis calligramma, QO. elegantula, Rhynchonella borealis, Rh. rotunda, Strophomena compressa, St. euglypha, St. funiculata, St. imbrex, and St. pecten,’ as well as with many species of Corals, Conchifera, Gasteropoda, Annelida, and Crustacea, peculiar to beds of the Wenlock age. It is further stated by Mr. Salter, who surveyed the ground (p. 13 of the same ‘ Explanation’), that Sp. dcjugosa occurs also in the Croaghmarhin or Aymestry beds in the same district, which contain abundance of Pentamerus Knightu, P. galeatus, Rhyn- chonella Wilsoni, and other fossils, such as are found in the Aymestry rocks of Siluria 1 This locality is spelt Dunquin on the one-inch map of the Ordnance Survey, also in the ‘ Explanation of Sheets 160, 161, 171, and 172, of the Geological Survey of Ireland, 1863,’ where will be found an excellent description of the beds and fossils by Messrs. G. V. Dunoyer and J. W. Salter. Mr. Baily informs me that Dunquin is a parish of some extent on the coast, joining Dunurlin, which includes Ferriter’s Cove; there is also a village of Dunquin, south of Clogher Head. He tells me that Wenlock rocks, with interstratified igneous rocks, much faulted, occur on the coast north and south of Ferriter’s Cove, between that and Clogher Head, as may be seen on the one-inch map, Sheet 171; also, that Ludlow rocks occur in the district; but that after having carefully searched the registers of fossils of the Irish Geological Survey, he could not find Sp. dijugosa in any locality of the Ludlow Rocks, but always in those coloured as Wenlock, and abundant at Ferriter’s Cove, that is, in the parish of Dunurlin, and also in what are considered to be the same rocks on the coast south of Clogher Head, in the parish of Dunquin. SPIRIFERID &. 91 (Shropshire, &c.); and the section of this west coast of Ireland is perfectly clear. Spirifera bijugosa occurs chiefly in the condition of external and internal casts, and has not been hitherto found in England, Wales, or Scotland. SPirIFERA suLcaTA, /Zisinger. PI. X, figs. 4—6. ANoMIA crRispa, Linné. Syst. Nat., 12th edit. p. 1152, 1767 ; and Mus. Tessin., p. 90, tab. v, fig. 7, 1753. DELTHYRIs suLcaTA, Hisinger. Anteckn. Physik. och Geognosi, p. 119, tab. iii, fig. 2, 1831. = — Ibid. Lethe Suecica, p. 73, tab. xxi, fig. 6, a, 6, c, 1837. SPIRIFER sULCATUS, Davidson. Bull. Soc. Géol. France, 2nd series, vol. v, pl. iii, fig. 41, 1848. = _— De Verneuil. Ibid., p. 347, 1838. SPIRIFERA suLCATA, Lindstrim. Proceed. Roy. Acad. Sc. Stockholm, p. 359, 1860. Spec. Char. 'Transversely subrhomboidal; hinge-line much longer than the width of the shell; cardinal angles pointed and extended; while, not uncommonly, one wing exceeds the other in length. Dorsal valve much less convex than the opposite one, bearing three or four principal ribs, of which the central one is both the largest and most elevated, the remaining lateral space being either smooth, or provided with one or two smaller or rudimentary ribs ; the three or five principal coste thus occupying either half or two-thirds of the surface of the valve. Ventral valve much deeper than the dorsal, with two or three ribs on each side of the sinus, which last is as broad as the width of the mesial rib or fold in the opposite valve ; surface of both valves crossed by numerous concentric projecting laminz, which overlap each other to a greater or lesser extent. Besides these, the surface is covered with a delicate network of small minute longi- tudinal and transverse strie, visible only by the assistance of a magnifying glass. Beak slightly incurved ; area rather wide, triangular, and divided in the middle by a fissure ; deltidium composed of two triangular plates, which rise abruptly from the lateral margins of the fissure with their broadest extremities near the umbone of the dorsal valve, thus leaving only a narrow oval aperture in the middle; with age, this opening becomes more and more diminished in extent. Two specimens measured— Length 6, width 10, depth 4 lines, ot a but the shell is usually much smaller. It is a smaller species than Sp. crispa. Oés. It is sometimes difficult to distinguish certain varieties of Spzrifera sulcata, Sp. crispa, and Sp. elevata, the last two of which especially pass one into the other to a perplexing extent ; nevertheless, when well shaped and full grown, they present recognisable distinctions; and paleontologists generally have considered it desirable that 92 BRITISH SILURIAN BRACHIOPODA. they should be described under separate heads. Such also is the opinion of my dis- tinguished friend Herr Lindstrom, who has devoted very great care and attention to the study of these species. Nevertheless, the question still demands further consideration. Much difficulty has also been experienced by palzontologists, with reference to the correct determination of these shells ; and great confusion has arisen from the uncertainty they have felt as to which form was intended by Linné as the type of his Azomia erispa. It must, however, be remembered, that at p. 1152 of the 12th edition of the ‘Systema Nature’ (1767), Linné has referred to the description and figure published in p. 90, tab. v, fig. 7, of the ‘Museum Tessinianum’ (1753),* for the source whence his Anomia crispa was derived, and a reference to that figure, which we have reproduced in our 1 8. ANOMIA angulis lateralibus dilatatis dentibus alternis, tab. v, fig. 7. Testa angulis utrinque dilatatis et dentibus alternis. Valvula superior in medio longitudinaliter suleis quatuor elevatis: ad latera vero sulco uno alterove. Valvula inferior medio elongata et adscendens apice, qui etiam, uti latera, sulcis duobus elevatis notatur. The original specimens described in the ‘Museum Tessinianum ” are, I am told, preserved in the Museum of the University of Copenhagen. In vol. i, part 2, of the ‘Systema Naturee,’ edit. 12, is written: * Anomia crispa, 232. A. testa dilatato-triangulari plicata sulcis rugosis: media latiore. “Mus. Tessin., tab. v, fig. 7. “ List. Angl., t. 9, fig. 56. “Habitat . . . fossilis. “Testa fere lunata, sed natum superior prominens sulci 5—6, rugis arcuatis transversis, Latera teste submucronata.”” It would not be fair to expect that at a period when the science of palzeontology was just about to spring into existence, the early observers, such as Linné, Lister, Plott, Fabius Columna, Bourguet, Bruguiere, Davila, Hupsch, Walch, Klein, Knorr, Rumphius, Volkmann, Ritter, Baumer, Andrez, Morton, and many others whose names we might mention, and who wrote previous _to the present century, should have been very accurate in their investigations, comparisons, indentifications, or illustrations ; for experi- ence and exactness, the fruit of immense labour acquired step by step, must necessarily have been exceedingly limited at those early periods; still it is sometimes necessary, when doubt is felt as to the type intended by any of these authors, to look carefully at their descriptions, however quaint they may be, and to the references to figures they may append. Now, in the case of Anomia crispa, Linné refers us also to Lister for a figure of his shell (t. ix, fig. 56), but a glance at Lister’s description (which we here append for the sake of illustration) will at once convince the merest tyro in our science that the shell represented in the ‘Museum Tessinianum,’ and that in the ‘ Historia Animalium Angliz,’ cannot belong to the same species. In fact, the first represents a small Silurian Spirifer; while the second illustrates a much larger and differently shaped Carboniferous species which Lister informs us he found in Lime- rocks, at Stock, in Craven, as his Latin description explains : “Lister. ‘ Historie Animalium Angliz,’ &c., 1678. “ Pectunculites anomius, cui insignis quedam lacuna per medium dorsum recta procedit, p. 247, t. 9. f. 56. [13. Tab. iii, 6. Tab. iv, p, Plott.] SPIRIFERID A. 93 Pl. X, fig. 12, a, B, may, perhaps, oblige us to conclude that Linné had in view a shell simliar to the one subsequently named De/thyris sulcata by Hisinger ; and this is admitted by the last-named author himself, who at p. 119 of his ‘ Anteckningar’ (vol. v, 1831), informs us that the description given by Linné of his Anomia crispa quite agrees with the one given by himself of Delthyris sulcata ; but that, as Dalman (it was, indeed, Hisinger himself, who did so before) had adopted a different shell under the name of erispa, which had not the larger median rib (?),’ he has been obliged to give to the Linnean species the new name of sw/cata. If we examine the Linnean figure of Anomia crispa, though badly drawn, we find that it represents a Sperifera with extended pointed cardinal angles, and three principal ribs in the dorsal valve, as we so commonly find to be the case with Swedish and British specimens of the shell under description ; while the form subsequently referred to, 4. crispa (Linn.), by Hisinger, Dalman, and subse- quent authors, has its hinge-lme shorter than the width of the shell, and its cardinal angles obtusely rounded. At page 128 of Hanley’s ‘Ipsa Linnei Conchylia’ (1855), Mr. Sharpe states that he could not ‘find a specimen in the Linnean Cabinet to which the whole of the Linnean description would apply; but that, simce the Swedes (Wahlenberg, Nilsson, Hisinger) have handed down so many of the fossil species of our (Plott gives no figure of this Spirifer; Lister refers to plates of Plott containing similar figures.) “ Descriptio. Hic lapis modice magnitudinis est; 4 latere ad latus feré sesquidigitum explet; a yertice ad imum ambitum uncialis est. In dorsum modicé elatus. “‘Medium dorsum profundior quedam lacuna recté dividit ; item ad imam illam lacunam ipse margo labri cujusdam instar paulo productior est. Reliquee etiam strize, ample, et torosz. “‘ Ipse vertex ex altera parte paulo angustior et aliquantulum rostratus est; adeoque inter anomios ponendus est. “ Juxta cervices quasi humeri acuti eminent, ut in Pectinitis, si aures lis demptz essent. “Tnsignem crassitudinem horum lapidum, qua parte testas referunt, satis mirari nequeo; certé multtm supra modum omnium viventium Concharum. At his eadem feré materia, que reliquis plerisque figuratis corporibus, in iisdem rupibus inventis ut Trochitis, de quibus alibi (‘ Philosoph. Transact. Dict. d. Oldenburgh,’ No. 100, p. 6181), fuse tractavi, sc. @ cujusdam fluoris natura. ** Locus. Ex his innumeros in saxo calcario sublivido plumbiferoque, quodam oppidulo regionis Craven, Stock dicto, inveni. Ubi omnes, quantum vidi, singulares fuerunt. “ At ex agro Staffordiensi bifores cinereos habemus; et ex ipsis submarinis rupibus juxta Scarborough bifores solidos, pellucidos, et quasi siliceos ipse exemi. “Tmo unum apud me servo ex silice proprié sic dicto albo et non pellucido, quod experimentum de chalybe captum abunde testatur. “N.B. Reliquis omnibus, exceptis iis, qui juxta Stock inventi sunt, isti humeri angulosi deesse videntur, imd aliquibus et labrum et lacuna haud ita conspicua sunt; easdem varietates plurimas in erystallis quibuscunque observare licet.”’ 1 T am at a loss to understand what Hisinger means, by stating that his Delthyris erispa has not the larger median rib ; for it exists in all the Swedish specimens I have seen. 94 BRITISH SILURIAN BRACHIOPODA. author in an unbroken line of tradition, confirmed in so many cases by the types in Linné’s collection, the Spirifer recognised by them as the Anomia crispa may be accepted with confidence.” I must also hasten to admit that when in 1847 Messrs. Salter and Sharpe, with myself, examined the Linnzan cabinet, we all acquiesced in the same opinion ; but we had all forgotten that the type of Anomia crispa formed part of the Tessinanian Collection, and we were ignorant at the time of the statement made by Hisinger, in vol. v of the ‘Anteckningar’ (1831). As, however, during so many years the terms sulcata, crispa, and elevata have been generally recognised, and made use of for the species published by Hisinger, Dalman, and others, it will be preferable, I think, not to disturb the present state of things, while pointing out what appears’ to be the probable type of Linné’s Anomia crispa. Bronn, at p. 1175 of his ‘Index Palzontologicus,’ considers Anomia crispa, Linné, Delthyris sulcata, His., and Spirifer octoplicatus, Sow. (pars ; ‘Min. Conch.,’ tab. 562, fig. 4), as referable to a single species; but this last reference, or identification, is erroneous, for Sowerby’s specimen, fig. 4, was obtained from the same rock and locality as figs. 2 and 3, namely, the Carboniferous Limestone of Derbyshire. D’Orbigny, in his ‘ Prodrome,’ retains also the Delthyris crispa of Hisinger (which he refers to Linné), as well as the Delthyris sulcata of the same author. In his enumeration of the Brachiopoda found by himself in the Island of Gothland, M. de Verneuil considers Spirifer sulcatus, Sp. crispus, and Sp. elevatus, as distinct species. I am, moreover, very uncertam whether M. Barrande is correct in referring fig. 2 of pl. xvun of his ‘Silurische Brachiopoden aus Bohmen,’ to Delthyris sulcata, His.; M. Barrande’s shell being much larger, and differmmg much in detail from the specimens found in England and in Sweden. As already stated, Spzrifera sulcata has often one wing less extended than the other ; and in some exceptional examples, one wing was much elongated and pointed, while the other was obtusely rounded; but this feature is common in those species of the genus which possess extended cardinal angles, as for instance, the. Devonian Spirifera Verneuilit, &c. It must also be noted, that in the larger number of English and Swedish specimens of Sp. sulcata, the number of large or principal ribs is limited to three or five; the others, when they exist, being much smaller and even rudimentary. For this reason, I feel certain that the shells figured by Prof. Hall in the second volume of his ‘ Paleontology of New York’ (p. 261, pl. 54, fig. 2, 1852), under the designation of Spirifer sulcatus, His., and De/thyris decemplicata, nm the ‘ Report Geol. Third District New York ’ (p. 105, fig. 4, 1843), do not really belong to Hisinger’s species, for they show a regular succession of from thirteen to seventeen ribs on each valve,—a condition never hitherto seen on any of the many Swedish and British examples of Sp. sudcata that have fallen under my obser- vation. I do not, therefore, quote his figures. It is not improbable, however, that the true Sp. sulcata may be found in the Niagara Group of Lockport, or of other places in the United States. SPIRIFERID 4. 95 Position and Locality. Spirifera sulcata occurs in the Wenlock Limestone at Dudley, Benthal Edge, Wenlock Edge, Lincoln Hill, and Hay Head, near Walsall; also in the Wenlock Shale, and the Wenlock Limestone of May Hill, Malvern, and Woolhope (Salter). It is not rare in rocks of a similar age in the Island of Gothland.? SPIRIFERA ELEVATA, Dalman. PI. X, figs. 7— 11. DrLTHYRIS ELEVATA, Dalman. Vet. Acad. Handlingar, f. 1827, p. 120, tab. iii, fig. 3, 1828. — — Hisinger. Lethzea Suecica, p. 73, tab. xxi, figs. 3, a, 6, 1837. SPIRIFER OCTOPLIcATUS, Sow. Silurian System, pl. xii, fig. 7, 1839 (not Sp. octo- plicatus, Sow., Min. Conch., tab. 562, 1827).” — prycHopDEs, Sow. (not of Dalman). Sil. Syst., tab. iii, fig. 13, 1839. ? — _— spurius (Barrande), Davidson and De Verneuil. Bull. Soc. Géol. France, 2nd ser., vol v, pp. 324 and 347, pl. iii, fig. 40, 1848. SPIRIFERA PTYCHODES, Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 293, 1848 (not of Hisinger). SPIRIFER suBsPuRIUS, D’Orbigny. Prodrome, vol. i, p. 42, 1849. — ELEVATUS, Idem. Ibid. — -- Morris. Catal. Brit. Foss., p. 151, 1854. — — Salter. Siluria, 2nd ed., pl. xxi, figs. 5, 6, 1859. SPIRIFERA suBsPURIA, M‘Ooy. Brit. Pal. Foss., p. 195, 1852. Spec. Char. Transversely rhomboidal; hinge-line nearly or quite as long as the width of the shell; cardinal angles either angular or slightly rounded. Dorsal valve less convex than the opposite one, with from eight to twelve simple ribs, which are divided by a mesial fold, equalling in width the adjoining two ribs, moderately elevated, and grooved along the middle. Ventral valve much arched and gibbous ; beak incurved ; mesial sinus as wide as is the fold in the opposite valve, and margined by a strong rounded rib or ridge on each side; from four to six ribs on either side of sinus. Surface of both valves regularly crossed by numerous slightly projecting lines, as well as by delicate longitudinal and transverse striz. Area triangular, moderately broad, fissure partly closed by a deltidium in two pieces. Specimens vary much in size; two measured— Length 9, width 12, depth 8 lines. Se eS a Obs. ‘This shell is one of the most common in our Upper Silurian rocks. It varies 1 I may here mention that, having received from my friend Lindstrém, of Wisby, a complete series of all the species of Silurian Brachiopoda hitherto discovered in Gothland, I have been able to carefully compare our British shells with those found in Sweden; and the student will be glad to know that Herr Lindstroém has sent a similar collection to the British Museum, which of course may be readily consulted there. 96 BRITISH SILURIAN BRACHIOPODA. considerably in shape and number of ribs; and I am informed by Lindstrom, that m Gothland it is not uncommon to meet examples showing every passage from forms with large acuminated ventral valves and almost flat areas, to others wherein the area is so narrow that the beaks are almost contiguous. In Dalman’s and Hisinger’s figure, the area is unusually large and triangular. Sometimes our British specimens are as long as wide ; and, when in fine preservation, the delicate longitudinal and concentric lines give to the shell under the lens a finely imbricated appearance. This is especially the case in casts. Prof. M‘Coy states, that in casts the two dental plates in the ventral valve are thick and short; and that a faint trace of the mesial septum exists on the ridge of the dorsal valve. This form more nearly resembles some specimens of Sowerby’s Spirifer octoplicatus, than it does either Spzrifera suleata or Sp. crispa ; and I am therefore not astonished that it should sometimes have been referred to the Carboniferous species. Indeed, some Devonian specimens seem undistinguishable from the Silurian shell. In 1848 M. de Verneuil and myself thought we could identify Speri/er spurius, Barrande, with the shell under description; but I am not quite certain as to the correctness of this view. Sp. plicatus,' Sharpe (‘ Quart. Journ. Geol. Soc.,’ vol. iv), has also been considered a synonym of Spirifera elevata; and. the specimens described and figured in the ‘ Paleeont. New York,’ vol. ii, p. 261, pl. liv, figs. 2a, 6, under the designation of Spirifer sulcatus, appear to me much more like Spirifera elevata than the shell to which they have been referred by Prof. James Hall. I am likewise quite at a loss to understand what can have induced Mr. Sowerby to identify the broken cast of Spirifera m ‘Sil. Syst.,’ tab. i, fig. 13, with Delthyris ptychodes, Hisinger (‘ Leth. Suec.,’ pl. xxi, fig. 8), and Dalman, ‘Acad. Handl.,’ tab. in, fig. 5), to which it bears no resemblance. Sowerby’s example above referred to belongs to Spirifera elevata; and his mistake has also been reproduced in Morris’s ‘ Catalogue of British Fossils ; and by Phillips and Salter in the ‘Mem. Geol. Survey,’ vol. ui, p. 293, 1848. Salter corrected it in ‘ Siluria.’ Position and Locality. Spirifera elevata ranges from the Upper Llandovery to the Ludlow Rocks. It occurs in the Upper Llandovery beds at Damory Bridge, Tortworth ; in the Wenlock Limestone of Dudley ; Benthal Edge ; Wenlock Edge ; May Hill; Wool- hope; Slate Mill, Hasguard, very large and fine (Salter); the Bell, Walsall; Hereford Beacon ; north of Canwood ; Dormington Wood and Lindel’s Green, in the Woolhope district. It occurs not uncommonly in the Llandovery beds at May Hill and Huntley Hill, &c. Also in the Wenlock Shale of Marloes, and of Dingle, Co. Kerry; in the Lower Wenlock (or Denbigh) grit-beds of Modwl Hithin, of Plas Madoc, and east of Merchlyn and Llanrwst, North Wales; and at Marloes, Milford, Freshwater, Llandeilo, Llangadoc, and Llandovery, in Wenlock beds (Salter’s MS. Catalogues). In the Lower Ludlow beds, at Hole Farm, in the Abberley district ; Dowlas, Coed-y- ! Orthis plicata, Vanuxem, Report, p. 112, fig. 1, a. : SPIRIFERID A. 97 Pan, Cefn Ila, 'T'y Newydd, Cilorgyr, etc., in the Usk district; at Crew’s Hill, Alfrick ; at Cwm Craig ddu, &c.; also in Ludlow beds at Kendal in Westmoreland, and Dingle, Co. Kerry. In the Aymestry Limestone of Sedgley, near Dudley, north-east of Pilliard’s Barn, Bodenham, in the Woolhope district ; Ankerdine Hill (Abberley district); Beech Hill, Llancayo, west of Darran, and Russell’s Farm, in the Usk district. In the Upper Ludlow beds at Dafaddfa Uchaf, in the Llandeilo district, South Wales, and Ludlow Lane; also at Frith, in the Malvern district. Prof. M‘Coy says it is abundant in the siliceous Upper Ludlow rock of Lambrigg Fell, Benson Knott, and north end of Potter’s Fell; all near Kendal, Westmoreland. It is found also in the Downton Sandstone in the Woolhope and Ludlow districts. On the Continent it occurs in rocks of the Wenlock age, in Gothland, as well as near Christiania in Norway. Prof. Schmidt has also found it in the Isle of Oesel. Sprrirera crispa, Hisinger. Pl. X, figs. 13—15. TEREBRATULA CRISPA, Hisinger (not of Linneus). Vet. Akad. Handlingar, tab. vii, fig. 4, 1826. Dettuyris crispa, Dalman. Vet. Acad. Handl., p. 222, tab. iii, fig. 6, 1828. — — Hisinger. Anteckningar, vol. iv, pp. 220 and 238, tab. vii, fig. 4, 1828. — — Td. Ibid. vol. v, p. 119, 1831. — _ Id. Lethe Suecica, p. 73, pl. xxi, fig. 5, a, 6, 1837. SPIRIFER crisPus, Von Buch (pars). Ueber Delthyris, &., p. 40, 1837. == — Sow. Sil. Syst., pl. 12, fig. 8, 1839. = — MCoy. Synops. Irish Sil. Foss., p. 37, 1846. _ — Davidson. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 325, pl. iu, fig. 42, 1848. oi — Hall. Pal. New York, p. 262, pl. liv, fig. 3, 1852 (perhaps, Sp. elevata, Dalman). — — Schmidt. Silur. Format. Ehstland, &c., p. 211, 1858. = — Salter. Siluria, 2nd edit., pl. xxi, fig. 4, 1859. SpirrFera crispa, M‘Coy. Brit. Pal. Foss, p. 193, 1852. = — Lindstrém. Proc. Roy. Acad. Sc. Stockholm, p. 360, 1860. Spec. Char. Shell small, transversely oval; valves moderately convex ; hinge-line a little shorter than the width of the shell; cardinal angles rounded. Dorsal valve rather less deep than the ventral, with three, five, or seven ribs, of which the central one is the largest, although in elevation exceeding but little those that are next to it on either side. Ventral valve rather more convex than the opposite one, plications two or three on either side of sinus. The whole surface of both valves covered by numerous, sharp, regular, concentric, slightly projecting lines of growth: beak moderately imcurved; area 13 _ 98 BRITISH SILURIAN BRACHIOPODA. triangular, of small dimensions ; fissure partly margined by a deltidium. ‘I'wo specimens measured— Length 5, width 6, depth 4 lines. Meme ee me "er Oés. As already stated in our observations on Sp. salcata, this shell, in 1826, 1827, and 1828, was considered by Hisinger and Dalman to be identical with the Anomia crispa of Linneeus, and it was only in 1831 that the first-named author found out his mistake. Since then, the same error, which originated in 1826, has been reproduced by all subsequent paleontologists, with the exception of Lindstrom. We will, however, retain the name of crzspa, Hisinger (not of Linné), for the shell under description, as the term has been so generally made use of in this country as well as upon the Continent by every geologist and palzontologist who has had occasion to refer to it. My friend Lindstrém writes me, that he feels uncertain whether the species occurs in our British Silurian rocks; but, after having compared several Gothland specimens of Sp. erispa with others found in England, I can see no difference; and it may be here remarked, that Hisinger’s figure is taken from avery young shell, and does not well Tepe the exact characters of fully developed specimens of his species.’ : Position and Locality. Sp. crispa occurs in May Hill Sandstone or Upper Llandovery at Ankerdine Hill: Woolhope Limestone, west of Worcester Beacon ; Wenlock Limestone and Shale, Clungunford, Shropshire; Craig-y-Garcyd, Usk River; Dudley; Callow Farm, &c., Abberley; Rock Farm and Checkley Common, May Hill; Canwood and Dormington, Woolhope district ; in Lower Ludlow at Hastnor Castle, Ledbury; Hole Farm, Abberley; Aymestry Limestone, at Ridge Hill Farm, Abberley (Phillips and Salter). It is a very common fossil in the Upper Silurian. It occurs also in Wenlock Rocks near Llandeilo (M‘Coy); Marloes Bay, Pembroke- shire ; near Llangollen; Dunquin and Ferriter’s Cove, Co. Kerry (M‘Coy). In Scotland it has been found by Mr. Henderson, in the Upper Silurian (Ludlow) Shales, at Deerhope Burn, in the Pentland Hills; and it occurs in the Wenlock Lime- stone at Kirkby Moor. It occurs in Gothland; also in Oesel, according to Professor Schmidt; and in the Niagara rocks of New York, according to Prof. Hall. I do not feel certain, however, whether the American fossil really belongs to Hisinger’s species. 1 Hisinger describes his Delthyris crispa as follows: ‘Testa transversali, convexo-gibba, longitudi- naliter 5—6-plicata et subtiliter transversim striati; foramine magno deltoideo, natibus remotis.’’ Dalman’s description is exactly similar, and he has copied Hisinger’s figure. SPIRIFERID A. 99 _Spreirera (Cyrrta) uxporrecta, Wallenberg. Pl. IX, figs. 13—24. ANOMITES EXPORRECTUS, Wahlenberg. Nova Acta Regize Soc. Scient., vol. vili, p. 64, No. 3, 1821. CyRTIA TRAPEZOIDALIS, Hisinger. Bidrag. Sver. Geogn. Anteckn., vol. iv, p. 220, tab. iv, fig. 1, a, b,c, 1828. — exporrecta, Dalman. Kongl. Vet. Acad. Handl., p. 118, tab. iii, fig. 1, 1828. —- TRAPEZOIDALIS, Id. Ibid., p. 119, pl. iii, fig. 2, 1828. — — Hisinger. Lethzea Suecica, p. 73, tab. xxi, fig. 1, a, 6, 1837. —= EXPORRECTA, Id. Ibid., pl. xxi, fig. 2, a, 6, ce, 1837. SPIRIFER TRAPEZOIDALIS, Von Buch. Ueber Delthyris, &c., p. 41, 1837. — — Sow. Sil. Syst., pl. v, fig. 14, 1839. _— — Bronn. Lethza Geogn., tab. iii, fig. 3; Index Pal., p. 1183, 1848. — — Davidson. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 324, pl. iui, fig. 43, 1848. — — Barrande. Naturwiss. Abhandl., vol. ii, pl. xvi, fig. 1, 1848. — PLICATELLUS, var. EXPORRECTUS, Salter. Mem. Geol. Surv., vol. ii, pt. i, p. 382, 1848. — — var. TRAPEZOIDALIS, Id. Ibid., p. 382. 1848. Sprrirera (CyRTIA) TRAPEZOIDALIs, M‘Coy. Brit. Pal. Foss., p. 196, 1852. SPIRIFER TRAPEZOIDALIS, Salter. Siluria, 2nd edit., pl.-xxi, fig. 3, 1859. SPIRIFERA EXPORRECTA, Lindstrém. Ofv. Vet. Akad. Forhandl., p. 358, 1860. Spec. Char. ‘Trigonal; valves convex; hinge-line nearly or quite as wide as the width of the shell; cardinal angles rectangular, or obtusely rounded. Ventral valve pyramidal, much more convex than the dorsal, with an angular median sinus, extending from the extremity of the beak to the front. Beak straight or incurved, at times more or less inclined backwards: area variable in its dimensions, usually large, triangular, some- times almost equiangular; fissure narrow, entirely arched over by a convex deltidium, which presents an elongated depression along its posterior portion, and terminated anteriorly by a small oval foramen, which became cicatrised with age. Dorsal valve semicircular; sides gently convex or rounded, forming a deep subquadrate lobe at the margin : the fold of moderate width and elevation, flattened along the middle. Surface of both valves covered with numerous, fine, longitudinal, raised, thread-like striz, which increase in number as they proceed towards the margin by bifurcation as well as by the interpolation of additional striz. In the interior of the ventral valve the hinge-teeth are supported by short shelly plates, which diverge and extend from the extremity of the beak, forming the fissure-walls, and occupying about one third of the length of the bottom of the valve: between these there exists a slightly raised longitudinal ridge (but not septum), which divides the muscular impressions. In the interior of the dorsal valve the 100 BRITISH SILURIAN BRACHIOPODA. arms are supported by spiral coils, directed outwards. Shell impunctate. Two specimens measured— Length 13, width 12, depth 9 lines. 3» /ALBse33 AA oe ee Obs. Paleontologists seem generally agreed to consider Spirifera (Cyrtia) exporrecta, and Sp. (C.) trapezoidalis, as simple variations in shape of a single species; and, since the designation exporrecta (Wahlenberg) appears to be the earliest name, it is here adopted in preference to that of ¢rapezoidalis.' Although Wahlenberg refers to Walch? for a figure of his species, this must be a mistake, for the illustration in question does not (I believe) really refer to the species under description, or to the one to which the Swedish author had given the designation of eaporrectus. Walch informs us, moreover, that his shell had been found at Mecklenburg, and therefore could not be the same as the Silurian specimen from Gothland ; nor do Walch’s figures agree with what Wahlenberg had in view when he described his Anomites eaporrectus, for Walch’s figure represents the exterior of the ventral valve of a Spirifera with strong angular ribs, while none such occur in the Silurian species, whose valves are, on the contrary, finely striated. In Walch’s fig. A 4, also, the fissure, or deltidium, has not the character of the Swedish or British specimens of 1 Wahlenberg: gives the following description of his species in the ‘Nova Acta Reg. Soc. Se. Upsaliensis,’ vol. viii, p. 64, 1821: Anomites exporrectus, striatulus, nate alterius valvulee exporrecta in conum dimidiatum dorso canalicula- tum. Patella, Walch, in ‘ Naturforsch.,’ 7, p. 216, tab. iv, fig. Aa, et A 6 (Valvula longior). Reperitur rarius in Gothlandia, unde integrum exemplar nactus est Cel. J. Afzelius. Conus valvule longioris in hoc specimine superne paullo curvatus est, sed in aliis speciminibus imperfectis omnino rectus. De cetero valvulee omnino jugate sunt ut in precedente. Quin tota structura aliquantum accedat ad famosam Hiipschii Pantoffelmuschel, non est infitiandum. 2 In the ‘ Naturforscher,’ vol. vii, 1775, we find Walch’s description and figures, which we copy here for the sake of reference : TV. Von einem seltnen Patelliten aus dem Mecklenburgischen. Taf. iv, n. 1, a, . “Durch diese erhalten die Patelliten des Steinreichs die Hr. Diaconus Schroter im fiinften Stiick des Naturforschers so sorgfaltig und so griindlich beschrieben, eine Bereicherung. Dieser Patellit gehort zu denen mit iiber- gebogenem Wirbel, und unter solchen zu den sogenannten Dragoner- miitzen. Auch diese Theilen sich in verschiedene Gattungen, unter welchen eine vom Hrn. Diac. Schréter, die auf der einen Seite gestreifte, auf der andern glatte Patelle von Wrietzen genennt, und von ihm in besagtem Theil. Taf. iii, num. 6, in einer Zeichnung geliefert wird. “Von dieser Gattung ist diejenige Mecklenburgische, so ich hier mit- theile eine Gattungsart. Sie unterscheidet sich von der Wrietzner durch die starke Furche oder vertiefte runde Falte auf der vordern gestreiften Flache, welche Falten auf der hintern glatten Flache, wie bey verschiedenen Pectun- culiten erhaben ist. Dem ersten Ausehn nach sollte man diesen Patelliten fiir einen Pectunculiten halten. Allein er ist es nicht. Die vordere gestreifte Fliche und die hintere glatte Fliiche machen zusammen ein ganzes Schaalenstiick aus, die Grundflache ist offen, und unbedeckt, so wie bey allen Patellen.” SPIRIFERID &. 101 Sp. exporrecta ; but this is of little consequence, since both Dalman and Hisinger have correctly described and figured Wahlenberg’s Silurian Anomites exporrectus, which we must retain, omitting the reference to Walch. Sptrifera (or Cyrtia) eaporrecta varies considerably in shape, or rather in the dimen- sions and position of its area, as may be seen bya glance at the figures in our Plate; thus the triangular area, with an average breadth of eleven lines (at the hinge-line), and a Jength of from three to seven lines from the point of the beak to the hinge-line, would constitute Wahlenberg’s, Hisinger’s, and Dalman’s Azomites exporrectus; while Hisinger, and after him Dalman, gave the name of ¢rapezoidalis to those variations with a narrower area, as seen in fig. 17 of our Plate. This is not, however, the only difference observable in the area of this remarkable species ; for in some examples it is completely flat, almost equilateral and equiangular (fig. 16), and it recedes at a right angle, or even at more than a right angle, from the plane of the dorsal valve, while in other specimens it is more or less concave and incurved at the beak. Another character of great importance in this species resides in the shape of its deltidium, which varies, it is true, slightly in different specimens, but is always narrow and lanceolate; and, whatever may be its length, it does not appear to much exceed one line and a half in width at its base. It also entirely covers over the fissure; and in the Swedish and British examples it presents an elongated depression, which, commencing at the extremity of the angular beak, extends to a lesser or greater distance along its surface, and even sometimes to within a small distance of its basal extremity. At the inward extremity of this flat or slightly concave depression may be seen in many specimens, but not in all, a small oval aperture, which however is often cicatrised, leaving only a slight mark to indicate its former presence. The animal was no doubt attached during a part of its existence to marine objects by means of a pedicle, but with this moorage it afterwards dispensed. These arrangements have been carefully represented in the enlarged figures 19, 20, and 21 of our Plate. This character of the 1 Barrande’s figures of the Bohemian specimens of this species show no indication of the depression _ above described, nor of the foramen ; the deltidium being equally convex throughout. Ilence, the depres- sion in question may, perhaps, not always have been present. 2 For the reception of these shells, Dalman, in 1827, proposed the genus Cyrtia, with the following diagnosis : “Testa inzequivalvis eequilatera, valvee majoris dorso in semiconum vel pyramidem dimidiatum elevato, latere cardinali perpendiculariter plano,—foramine nullo. Cardo rectilineus.’”’ But, as I have already stated, at p. 83 of my “General Introduction,” Dalman’s diagnosis is unsatisfactory, and equally applicable to several species of Spirifera ; and the only character of any value that I can perceive, by which it might be distinguished from Spirifera, consists in its having the fissure entirely arched over by a deltidium which was at some period of the animal’s existence perforated by a circular foramen. Even this last character, however, is not present in all the specimens referable to this so-termed genus. In one remarkable form, Cyrtia Murchisoniana, the circular foramen, which sometimes presents a small, marginal tubular prolongation, is situated at, or close to the extremity of the beak, or of a long narrow deltidium, as may be seen in some Chinese specimens of the species which I described and figured in the ‘ Quarterly Journal of the Geol. Soc.’ (vol. ix, p. 353, pl. xv, figs. 6—9Y, 1853). If, therefore, the term Cyrtia is to 102 BRITISH SILURIAN BRACHIOPODA. deltidium is likewise so different from that observable in Spirifera plicatella, that it is quite sufficient to prevent the possibility of the last-named shell being considered as a variety, due to a difference in shape, of Spirifera (Cyrtia) exporrecta: and the same would apply to Sp. (C.) trapezoidalis, which is, as we have already shown, a synonym of Sp. exporrecta. It was long before I could expose portions of the spiral coils, and only after having broken open a large number of specimens. These coils are disposed as in Spirifera ; and the muscular arrangements are also the same. In the internal casts, as observed by Prof. M‘Coy, the slits left by the. dental plates are very strongly marked in the ventral valve, and our British examples agree entirely with those found in Gothland; but the deltidium is not correctly represented in either Hisinger’s or Dalman’s figures. Position and Locality. In England Spirifera eaporrecta ranges from .the Lower Llandovery to Ludlow Rocks (Salter), and is common in the Wenlock Limestone and Ludlow Shale through Shropshire ; also of Dudley and Abberley ; the Wenlock Shale of Rushall Canal, near Walsall; of Craig-y-Garcyd, Usk; of Nelson’s Tower Wood, Llandeilo. In fact, all through Carmarthenshire. It occurs too, but more rarely, in the Upper Llandovery or May Hill Sandstone of Tortworth, at Damory Bridge; in the Wen- lock or Woolhope (Denbigh) grit of Plas Madoc, Llanrwst, and other places in Denbigh- shire; in the Woolhope Limestone, Storridge, and under Worcester Beacon, Malvern ; and in the Lower Ludlow of Dog Hill, Ledbury. In Scotland it has been discovered by Messrs. Haswell and Brown, chiefly in the condition of internal casts, in the Upper Silurian (Wenlock) shales of the Deerhope Burn, near the North Esk Reservoir, Pentland Hills.* be retained, it cannot, I think, be considered in any other light than that of a subgenus or section of the great genus Spirifera. 1 A specimen from this locality is figured in pl. iii of Mr. Haswell’s little book on the ‘ Silurian Formation in the Pentland Hills’ (1865); but at that period, owing to the imperfect condition of the cast, neither its species nor genus could be accurately determined. Since then, the discovery of more perfect specimens has enabled me to refer without doubt these casts to Spirifera (Cyrtia) exporrecta of Wahlenberg. Since so many species of Brachiopoda have been discovered in the Upper Silurian rocks of the Pentland Hills, it may be interesting to append a short note upon the subject, kindly forwarded to me by Mr. A. Geikie, of the Geological Survey of Scotland. ‘ Under the massive unconformable conglomerate of the Pentland Hills, lies a series of highly inclined and even vertical strata, which for many years were classed with the ‘Greywacke’ of the ‘transition’ rocks of the south of Scotland. Two Orthoceratites had been found in these strata previous to the year 1839, by the late Mr. Charles Maclaren, but the specimens went amissing, and the species was not determined at the time of the publication of his ‘Geology of Fife and the Lothians.’ One of the specimens eventually found its way into the Collection of Hugh — Miller, who showed it to me. It was lent by him some time before his death to Sir R. Murchison, with the view of being named and described in the next edition of ‘ Siluria.’ Before that edition appeared, however, in 1858, the Geological Survey had began to map the area of the Lothians, and I had sueceeded in detecting in the so-called ‘Greywacke’ of the Pentland Hills several other fossils. The Orthoceras was named d. Maclareni; and it most resembled a Wenlock species. The Silurian rocks of the SPIRIFERID &. © 103 It occurs in the Island of Gothland ; and was found by M. Barrande in the Silurian rocks of the neighbourhood of Prague, in Bohemia, where the shell attained larger dimen- sions than it appears to have ever had in England or Sweden. Palzontologists have, in various works, described as Spirifers several other shells that I find do not belong to the genus, and which will be found under other names in Pentland Hills are regarded by Sir Roderick as Upper Silurian, and some of them are probably of Wenlock age. Further examination of the tracts on the North Esk and Lyne Water showed that at places these Silurian rocks are richly fossiliferous. I made a considerable collection, which was after- wards largely increased by the labours of Mr. Salter and Mr. R. Gibbs. The result of these researches went to show that, at least, the upper portion of the Silurian series of the Pentland Hills is of the age of the Ludlow rock; while certain red sandstones and conglomerates overlying the olive-coloured fossili- . ferous beds were held to mark the base of the Old Red Sandstone. “The following is the section, in descending order, as far as the disturbed character of the strata will allow it to be made out. Red conglomerates, sandstones, and shales = Base of the Lower Old Red Sandstone (?). «3. Olive and brown sandy shales, sandstones, and mudstones, some of the beds full of Ludlow fossils. ‘ ; i «2. Hard sandstone and beds of quartzose grit, containing among other obscure shells, Orthonota amygdalina, Mytilus, Avicula, a shell like Platychisma simulans, Orthoceras, and numerous fragments like Fish plates or scales. “1. A thick series of green, grey, and reddish shales, with bands of hard grit and sandstone, contain- ing in some places abundant remains of Dictyocaris. “The basis of this series is concealed under the conglomerates of the Middle (?) Old Red Sandstone series ; but the whole visible thickness of the Upper Silurian rocks was estimated by me to range between 3000 and 4000 feet. In this mass of strata, while the upper portion is undoubtedly of Ludlow age, there is room also for the representation of the Wenlock Rocks.”’ Subsequently to Mr. Geikie’s researches, several members of the Geological Society of Edinburgh, among whom we may more particularly name Messrs. G. C. Haswell, D. J. Brown, and J. Henderson, have devoted much time to the study of these beds and to collecting their fossils; and I had the pleasure of visiting the locality during the spring of 1866. Mr. Haswell has also, in an interesting little brochure, ‘On the Silurian Formation in the Pentland Hills’ (1865), given us a description of the locality, and of many of its fossils. He is of opinion that it is in the “Mudstone H” of his map, in Deer-Hope Burn, and belonging to the Wenlock period, that the greatest number of Brachiopoda occur ; while, in the upper beds (at “I” of his map, and on the same stream), referable to the Ludlow, the only Brachiopods hitherto found are Rhynchonella Pentlandica, Spirifera crispa, and Lingula lata. The following is a list of the species of Brachiopoda I have been able to determine from these beds. They have been collected by the gentlemen above named; and in an interesting paper read by Messrs. Brown and Henderson to the Geological Society of Edinburgh, will be found some new and important matter in connection with the distribution of these fossils. Lingula lata, Sow.; Discina rugata (?), Sow.; Crania implicata, Sow. ; Spirifera crispa, His. ; Sp. (Cyrtia) exporrecta, Wahl.; Meristella tumida, Dal.; M. (?) Maclareni, Haswell ; Athyris compressa, Sow. ; Nucleospira pisum, Sow.; Atrypa reticularis, Lin. ; Rhynchonella Pentlundica, Haswell; Rh. Wilsoni, Sow.; Rh. nucula, Sow. ; Rh. crispata (2), Sow.; Orthis elegantula, Dal.; O. biloba, Lin. ; O. Lewisii, Dav.; O. calligramma, Sow. (?); O.? minuta, Haswell; Strophomena applanata, Salter ; St. pecten, Linn.; St. antiquata, Sow.; St. rhomboidalis, Wahl. ; S¢. Walmstedti, Lindstrom; Leptena transversalis, Dal.; and Chonetes striatella, Dal- 104. BRITISH SILURIAN BRACHIOPODA. this Monograph. ‘Those described in the preceding pages are the only British Silurian species of the genus with which I am at present acquainted. In a paper on the Pebble-bed of Budleigh-Salterton, published in the ‘ Quart. Journ. Geol. Soc., London,’ vol. xx, p. 295, pl. xvi, figs. 10 and 13, Mr. Salter describes two species of Spirifera, Sp. antiqussima, Salter, and Sp. Davidsi, Rouault (?), as of perhaps Lower Silurian age ; but that distinguished and experienced paleontologist does not omit to add, “These are the oldest known species of the genus; if indeed it be not the case that there are, as above suggested, pebbles from some Devonian rock, mixed with others.” Since the above lines were published, I have received from Messrs. Vicary and Valpy the loan of a considerable number of specimens of the above-named species, and I am of opinion that they are of Devonian age, and referable to a single species, that species being Spirifera Verneuilii, Murchison, a well-known and far-spread Devonian shell. I may likewise add, that, after a careful study of several hundred specimens of Brachiopoda from the Budleigh-Salterton Pebble-bed, collected by Messrs. Valpy, Vicary, and Winwood, I was able to make out some thirty distinct species of Brachiopoda, of which more than half are, in my opinion, of Devonian age, while some few only appear to be Silurian. Genus—Nvucueospira, Hall. Hat, Paleontology of New York, vol. iii, p. 219 (printed in 1857, published in 1859); and Twelfth Report on the State Cabinet, New York, p. 24, 1859. Types—NvcLEosPira VENTRICOSA, N. concrinnA, and N. Pisum. Never having had the opportunity of studying the interior character of this genus, otherwise than through the medium of Prof. Hall’s description and figures, I cannot do better than reproduce the author’s diagnosis. “Shell spheroidal or transversely elliptical, more or less gibbous or ventricose, furnished with internal spires as in Spirifer : hinge-line shorter than the width of the shell ; cardinal extremities rounded: valves subequal, articulating by teeth and sockets. Ventral valve having the beak extended beyond the opposite valve; and beneath it a triangular depression or area, which sometimes terminates in a shallow spoon-shaped pit, on each side of which, at the base, is a strong tooth. A. narrow ridge or septum extends along the centre of the inner side of the valve, from beak to base. Dorsal valve furnished with a strong spatulate cardinal process, which, rising vertically from the cardinal margin, is closely grasped at its base by the cardinal teeth of the other valve ; and thence bending abruptly upwards, and expanding, is projected into the cavity of the opposite beak, lying close upon the underside of the false area. ‘This process is grooved or depressed in the centre of the upper side, so as to leave between it and the arch of the ventral beak a SPIRIFERIDA. — 105 narrow space for the passage of a pedicle, for the protrusion of which a minute foramen is sometimes observed in the beak. From the sides of this process, above the junction of the teeth of the opposite valve, and at the point where it bends upwards, originate the crural processes which support the spires. A deep cavity beneath the cardinal process extends to the dorsal beak, from which originates a thin elevated septum, running to the base of the shell. Muscular imprints confined to a narrow oval space. Surface apparently smooth ; under a lens, punctate ; shell-structure dotted, and, when perfect, covered with minute hair-like spines. “ Observations. In Murchison’s‘ Silurian System,’ Mr. Sowerby has described, under the name Spirifer ? pisum, a species differing essentially in general external characters from the typical forms of that genus. This species has been adopted as a true Spirifer in Morris’s ‘Catalogue of British Fossils,’ and in the ‘Nomenclator Paleontologicus’ of Broun, as well as elsewhere. Subsequently I discovered in the Niagara Shales a form so similar to the British species that I regarded it as identical; but from the condition and character of the specimens, I considered them as more nearly allied to Orthis than to Spirifer, and, accordingly, in the Second Volume of the ‘ Paleontology of New York,’ I designated the Niagara fossil ‘ Orthis pisum.’ “ Since that period my collections from the Helderberg have revealed a species similar to the one from the Niagara group; but among the numerous individuals from the latter rocks, I found several which were clearly furnished with internal spires like the true Spirifer, thus separating it from Orthis by unequivocal characters. Finding no genus for the reception of these forms, I described the latter as Spurifer ventricosus ; and it has been so published in my Descriptions of New Palzeozoic Fossils in the ‘ Report of the Regents of the University upon the State Collections of Natural History.’ ** Further examination has satisfied me of the impropriety of placing this fossil under either of the genera named, for several reasons. ‘The central depression, line, or narrow sinus, which might be regarded as the mesial sinus of Spzrifer, is almost equally a , character of both valves. The apparent area is not a true area; and the apparent fora- men, being merely a depression in the false area, does not correspond to the foramen either of Spirifer or of Orthis, not opening into the cavity of the shell. The hinge-line is not extended in the manner of these shells, particularly of the former; while the presence of a spire sufficiently distinguishes it from the latter. «« The lower Helderberg group furnishes one, and perhaps two other species ; and | find that the fossil described by me as Aérypa concinna in the ‘ Report of the Fourth Geological District’ (1843) is another species belonging to the same group of fossils, in which both the external characters and internal structure differ so essentially from any of the described genera of Brachiopoda as to constitute a distinct genus, and which, from the general nucleolar character of the known species, I propose to designate NucLEosPIRa.” 14 106 BRITISH SILURIAN BRACHIOPODA. NvcLeosPira PisuM, Sow. (sp.). Pl. X, figs. 16—20. Spirirer ? pisuM, Sow. Silurian System, p. 630, pl. xiii, fig. 9, 1839; and ‘Siluria,’ 2nd edit., pl. xxi, fig. 7, 1859. SprrirFeERA — Phillips and Salter. Mem. Geol. Surv., vol. ii, p. 293, 1848. SPIRIFER — Dav. Bull. Soc. Géol. France, 2nd ser,, vol. v, p. 325, 1848. — — Bronn. Index Pal., p. 1180, 1848. ATRYPA — wD Orb. Prodrome, vol. i, p. 37, 1849. Hemytuyris?— M‘Coy. Brit. Pal. Foss., p. 205, 1852. OrtTHIS — Hall. Pal. New York, vol. ii, p. 250, pl. lii, fig. 1, 1852. Nuc.eospira — Id. Ib., vol. iii, p. 218, 1859. Spinicera? — Lindstrim. Ofv. K. Vet. Akad. Forhandl., p- 361, 1860. Spec. Char. Shell small, suborbicular, very convex ; valves almost equally convex, and gibbous near the beaks ; beaks very small, incurved, that of the ventral valve being a little more elevated or projecting than that of the opposite valve; hinge-line straight, much shorter than the width of the shell; cardinal angles rounded; sides and front circular, or slightly narrowed and indented in front. Ventral valve a little deeper than the dorsal valve, with a slight depression down its centre. Dorsal valve most convex close to the umbone, with a faint line along its centre; but after reaching to about the centre of the valve, this line is gradually converted into a slight depression or sulcus. False area small, triangular, with a depression in the middle. Surface of both valves closely covered with long, slender, hair-like spines; but when these are destroyed by fos- silization, the shell appears smooth and minutely punctate. Interiorly, each of the spiral coils is composed of six or seven convolutions, and are fixed to the hinge-plate of the dorsal valve. ‘Two specimens measured— Length 4, width 5, depth 3 lines. » 53, » 5, 4, 938 4, - QOés. As will be seen from the list of references, this small shell has been placed in no less than six different genera, namely, Spirifera, Atrypa, Hemithyris, Orthis, Spirigera, and, lastly, in Nucleospira, where I trust it may find a permanent home. Dr. Lindstrém informs me that Prof. Angelin named this species Zerebratula pachygaster in his ‘ Museum Palzontologicum Suecicum,’ 1838. At p. 205 of his ‘ Brit. Pal. Fossils,’ while treating of this shell, Prof. M‘Coy states—“TI have ascertained, by carefully breaking a specimen, that there are no internal spiral appendages, and therefore the species does not belong to Spirifer ; and I have observed a large triangular opening beneath the beak, so that it does not belong to Atrypa, where M. d’Orbigny has placed it.”” That Prof. M‘Coy should not have discovered the spirals after breaking a specimen is not surprising, and he might have broken twenty more without discovering a trace of their existence, for they appear to have been very often destroyed in the process of fossilization. I have ea SPIRIFERID Ai. 107 myself broken and sliced many specimens of different species which possess spiral appendages before obtaining them. It is therefore not always safe to assert that a species may not have possessed certain appendages because they are not exposed on breaking a specimen. Now, in WVucleospira pisum they may often be seen without fractur- ing the shell, through its transparent walls, as in the specimen fig. 18 of our Plate. The internal details of this species have been already given in full by Prof. Hall, in the generic description, and consequently need not be again repeated ; but we must mention the long hair-like spines which so closely cover the perfect shell; and my attention was first turned to this circumstance by Dr. Holl, who sent me a specimen so invested, which he had discovered in the Wenlock Limestone of Colwall Copse; and there are others preserved in the Natural History Museum at Worcester. Position and Locality. Nucleospira pisum occurs in the Wenlock Limestone and Shale of Hay Head, near Walsall; Wren’s Nest, Dudley; and Benthall Edge, in the Wenlock district; Colwall Copse, Malvern; Dormington and Lindels, in the Woolhope district. Under Worcester Beacon, in Woolhope Limestone. In Scotland internal casts have been recently discovered in the Wenlock shale of the Pentland Hills, by Messrs. D. J. Brown and J. Henderson, of Edinburgh. These I will figure in the Supplement. ‘This species has also been found in Gothland. Prof. Hall obtained it from Walcott, New York State, in shales of the Niagara Group. Genus or Sub-genus Muristewia, Hall, 1860. Hall. Thirteenth Report on the State Cabinet of New York, p. 73, 1860.—Fifteenth Report, &c., p. 179, 1862.—Sixteenth Report, &c., p. 50, 1863. I need not here repeat the reasons which induced Prof. Hall to propose the generic or subgeneric designation of Meristel/a for shells typified by Atrypa tumida of Dalman ; these details are given in a foot-note in pp. 13, 14, and 15 of my ‘ Monograph of Devonian Brachiopoda,’ 1864. At p. 50 of the ‘Sixteenth Report’ Prof. Hall adds the following observations to those he had published in 1860 :—‘‘The genus Murisretia includes Zerebratuloid or Athyroid forms which are ovoid, more or less elongate, sometimes elliptical in outline, and not unfrequently transverse or sub-circular; valves unequally convex, with or without a median fold and sinus; and this feature, when present, usually confined to the lower half of the shell. Ventral beak more or less closely incurved (when closely incurved, apparently imperforate), terminated by an aperture, the lower side of which may be formed 108 BRITISH SILURIAN BRACHIOPODA. | by the umbo of the dorsal valve, or by a deltidium; area none; valves articulated by teeth and sockets. Surface smooth, or marked by fine concentric lines of growth (not lamellose), and indistinct or obsolescent radiating striz, which are usually more con- spicuous in the cast or exfoliated surfaces than on the exterior. Shell fibrous. The ventral valve is much thickened on each side towards the beak, and the rostral cavity margined by flattened dental lamella, which extend downwards to the commencement of the muscular impressions, and terminate at the edge of the shell in blunt, tooth-like pro- cesses. The muscular impression forms a somewhat broadly triangular depression in the valve, just below the rostral cavity. In the cast of this valve we have the reverse of these features. In the dorsal valve there is a strong hinge-plate or process, the prominent part of which is broadly triangular, somewhat depressed or spoon-shaped in the centre, and supported below by a median septum, which reaches from one third to one half the length of the valve, and on each side marked by deep dental fossets, while the anterior angles are produced into the crura which support the internal spires. Spires arranged as in Athyris and Merista, being a double cone with the apices directed outwards. From the lower lateral margins of the cardinal process or hinge-plate there is a callosity extending beneath the anterior to the dental fossets, and joining with the thickened margin of the valve, as in the other allied genera. “Tn the cast of the dorsal valve we have the mark of the median septum, with an elongated lanceolate muscular impression, reaching nearly to the middle of the valve. The imprint of the triangular process, and the cavities made by the crura, are often pre- Setvedenin se The difference between Athyris (== Spirigera) and Mervstella are everywhere clear and unmistakable, in the external lamellose surface of the one and the almost smooth character of the other. The muscular impressions of the ventral valve of Athyris are at once distinguishable from those of dJeriste/ia. In the dorsal valve, the muscular impressions differ from MJeristella, the hinge-plate is of somewhat different character, and the median septum is scarcely developed.”* I must, however, hasten to observe that, from want of sufficient material, it has not been possible for me, in some cases, to determine with absolute certainty whether some of the species should be placed in the genus Atrypa or Meristella. ' At pages 282—303 of the fourth volume of his ‘Paleontology of New York’ (1857), Prof. Hall describes, at great length, the characters which distinguish Meristel/a from Athyris ; and he illustrates a series of very remarkable preparations made by Mr. R. P. Whitfield, showing the very complicated manner in which the two spiral coils are attached to each other in the middle, as well as to the hinge-plate, in various species of the above-named genera, This, though different in detail, bears a certain resemblance to what I described and figured in Athyris pectinifera, at p. 21 of my ‘Monograph of British Permian Brachiopoda.’ SPIRIFERID &. 109 MERISTELLA TUMIDA, Dalman (sp.). Pl. XI, figs. 1—13. TEREBRATULA OBTUSA, Sow. Trans. Linn. Soc., vol. xii, p. 516, pl. xxvii, figs. 3, 4, 1815. Atrypa TumIDA, Dal. Vet. Akad. Handl., p. 134, pl.v, fig. 3, 1828. TEREBRATULA TUMIDA, Von Buch. Ueber Terebrateln, &., p. 103, 1834. ATRYPA TUMIDA, Hisinger. Lethzea Suecica, p. 77, pl. xxii, fig. 5, 1837. — TENUISTRIATA, Sow. Sil. Syst., pl. xii, fig. 3, 1839. TEREBRATULA TUMIDA, Barrande. Sil. Brach. aus BOhmen; Naturw. Abhandl., vol. i, ' pl. xv, fig. 11, 1847. — — Dav.et de Vern. Bull. Soc. Géol. France, 2nd ser., vol. v, pp. 226 and 246, pl. iii, fig. 26, 1848. — — SBronn. Index Pal., p. 1254, 1848. Arrypa TUMIDA, Phillips and Salter. Mem. Geol. Surv., vol. ii, p. 279, 1848. Merista — Schmidt. Silur. Format. Ehstland, &c.; Archiv Nat. Liv- Ehst- und Kurlands, vol. ii, p. 209, 1858. Sprricera— D’Oré. Prodrome, vol. i, p. 43, 1849. AtHyrgis — M*‘Coy. Brit. Pal. Foss., p. 196, 1852. — — Morris. Cat. Brit. Foss., p. 131, 1854. — — Salter. Siluria, 2nd edit., pl. xxii, fig. 20, 1859. MERISTELLA TUMIDA, J. Hall. Thirteenth Annual Report of the Regents on the State Cabinet of New York, p. 73, 1860. MERIstTa — Lindstrim. Ofy. K. Vet. Akad. Forhandl., p. 161, 1860. Spec. Char. Shell variable in form, subcircular or rotundo-quadrate, usually a little wider than long; sometimes the width not exceeding the length. Valves almost equally deep and tumid. Dorsal valve uniformly convex to about the middle; the fold, which is confined to the anterior half, gradually rising from the lateral portions of the shell into a squarish elevation, divided along the middle by an angular depression or groove, which is continued to the umbone. The fold is also usually curved upwards, so that when viewed in profile the valve is convex from the umbone to about half its length, forming afterwards a concave curve to the extremity of the fold. Ventral valve convex, with a wide square or obtuse sinus, commencing at about the middle of the valve, and extending to the front. It is also divided by a narrow groove, which, originating at the extremity of the beak, extends to the front. The lateral margins are rounded; front margin straight when the shell is young, but gradually rising, so as to form a rotundato-quadrate lobe towards the dorsal valve: beak small, and so much incurved as to almost touch the umbone of the opposite valve; no area or foramen visible. Surface of valves smooth, or marked only by fine concentric lines of growth, which are here and there stronger. The interior of the ventral valve is thickened at the beak, and especially for some short distance between the two strong dental plates, which extend along the bottom of the valve by a concayo-convex curve to 110 BRITISH SILURIAN BRACHIOPODA. about the middle of the valve, leaving between them a pear-shaped depression filled by the scars of the occlusor and adjustor muscles. The interior of the dorsal valve has, under the incurved beak, a small hinge-plate, divided in the middle; each half broadly triangular and depressed along the centre; these hinge-plates are supported below by a median septum, which extends to a little more than one third of the length of the valve. On the outer side of the hinge-plate are excavated the dental sockets, and to the hinge-plate is attached a complicated system of lamelle, which form the spiral coils, with their extremities directed outwards or towards the lateral margins of the shell; each spiral being composed of about fifteen convolutions. The adductor or occlusor muscular impressions are oval scars close to and on either side of the lower portion of the septum. Ovarian pits are also in some specimens observable on the visceral portion of the interior. T'wo specimens measured— Length 23, width 23, depth 17 lines. 50 LG, Y 5; Ae lec Ods. I have devoted an entire Plate to the variations in shape assumed by this remarkable species. Fig. 9 is viewed from the beaks, in order to show the two diverging lines, which are in some specimens visible through the transparent shell, and which, commencing at the extremity of the beak in the ventral valve, extend to about one third of its length. ‘These, and the single central line in the dorsal valve, indicate the position of the hinge-plates and septum in the interior. The external surface in all the many specimens I have examined was smooth; but when the specimen is slightly decorticated, the fine radiating strize described by Mr. J. de C. Sowerby are observable. The species appears to have been described for the first time about 1815, by J. Sowerby, under the designa- tion of Zerebratula obtusa; and he also at the same time gave a figure of the exterior, and another in which portions of the spiral coils were exposed, so that in reality, were the rules of priority to be strictly adhered to, the shell under description ought to retain the designation of Meristella obtusa, Sow., sp.’ In 1827 the same shell received from Dalman the designation of Atrypa tumida ; and, 1 In vol. xii, p. 515, of the ‘ Linnean Transactions,’ Sowerby describes his shell in the following words :— ‘Since I presented a sketch of an Anomia or Terebratula with internal cartilage (it was Spirifera striata), I have received a species of Terebratula of a very different construction, with a spiral cartilage; and I con- ceive that a figure of this species would be a convenient addition to my former communication, as showing that the spiral cartilage is less confined to shells of a certain external form than might have been expected. Such as I had seen before had straight elongated hinges, and the deeper shell had a triangular foramen, or distant curved beaks indicating it; the present sketch, figs. 3, 4, represents a shell curved laterally from the hinge, which must be very short; the beaks are very small, and without any space for a triangular foramen externally ; although within there appears a nearly triangular appendage to the cartilage, which, if not possessed of the outer shell, might indicate a triangular foramen. I presume to lay this sketch before the Society, hoping the subject will meet with attention and investigation when opportunity offers. The construction of the shells in my former communication would, without the present specimen, have given an idea of the straight hinge being peculiar to those Zerebratule with a spiral cartilage, as agreeing with SPIRIFERID &. Iit as this specific name has been generally adopted, it would not, I think, be desirable to alter it now, especially as no one has made use of Sowerby’s name. It is, however, strange that Mr. J. de C. Sowerby, who was fully cognisant of his father’s prior claims, since he quotes them in his description, should, in 1839, have described the same shell under the appellation of Atrypa tenuistriata, a name which has not, however, been sub- sequently adopted. Mr. Salter first referred the English shell to Dalman’s Afrypa tumida ; and the shell has since been shifted from genus to genus, as will be seen by a glance at our list of Synonyms, until it has finally been taken as the type of Prof. Hall’s genus Meristella. Position and Locality. Meristella tumida is a common shell in the Wenlock limestone of Dudley, Woolhope, Benthall Edge, the Rushall Canal near Walsall, May Hill, &c. Prof. Phillips and Mr. Salter mention Storridge, Ledbury, Hereford Beacon, and Eastnor Park ip. the Malvern District, and the Wenlock limestone and Lower Ludlow of Hill End, at Abberley and Callow Farm in the Abberley district. North of Canwood, Dormington Wood, Hast of Canwood and Lindels, in the Woolhope district. West of Rock Farm, Rock Farm, North of Taynton, in the May Hill district. In the Aymestry limestone of Llanbadoe and Russell’s Farm, in the Wenlock limestone and shale of Cilfigan, 'ly-newydd, Trostrey, Bryn Craig, Craig-y-garcyd in the Usk district, and at ‘T'y-newydd, Keeper’s Lodge, &c., in the Llandeilo district. In Scotland it has been found by Mr. J. Hen- derson, in the Wenlock shales of the Pentland Hills. It occurs in Gothland; also in the neighbourhood of Christiania in Norway. Prof. Schmidt mentions having found it in Russia; and M. Barrande obtained it near Prague in Bohemia. MERISTELLA ANGUSTIFRONS, A/‘Coy (sp.). Pl. X, figs. 21—27. HEMITHYRIS ANGUSTIFRONS, J/‘Coy. Ann. Mag. Nat. Hist., 2nd ser., vol. viii, p. 391, 1851; Brit. Pal. Foss., p. 199, pl. 1 H, figs. 6 to 8, 1852. TEREBRATULA _ Salter. Quart. Journ. Geol. Soc., vol. vii, pl. ix, fig. 10, 1851. RHYNCHONELLA = — Morris. Cat. Brit. Foss., p. 146, 1854. — — Salter. ‘ Siluria,’ 2nd edition, p. 230, Foss. 48, fig. 2, 1859. Parkinson and Martyn, and might therefore have been misleading. The spiral remains in the present species seem rare, as most of the shells are filled with a hard marly earth. It was found with some other species in Sladacre’s Quarry, on the right hand side of the road leading from Wych to Colwell Green, a part of the Malvern Hills.” I have experienced some difficulty in ascertaining exactly the date at which Sowerby’s description of 7. obtusa was really published. The date at the commencement of vol. xi of the Linnean Society’s Transactions is 1818; but the part containing Sowerby’s description of 7. obtusa has the date wanting. The paper, however, appears to have been read partly on the 6th of December, 1814, and partly on February 17th, 1815. IZ BRITISH SILURIAN BRACHIOPODA. Spec. Char. Ovate, longer than wide; valves almost equally and regularly convex ; no regular fold or sinus, but a slight elevation is perceptible near the front in the dorsal valve ; sides rounded, and narrowed towards the front, which is also either straight or gently rounded. Beak more or less incurved, with a small triangular opening visible under its angular extremity; but this is often concealed by the incurvation of the beak. Surface smooth, marked only with a few concentric lines of growth. Shell-structure impunctate. ‘Two specimens measured— Length 9, width 6, depth 43 lines. > 8s, ee ore Obs. Prof. M‘Coy was the first to describe this species; but he was in error when placing it in d’Orbigny’s genus Hemithyris, which is itself no more than a synonym of Rhynchonella ; for, as may be seen in a specimen discovered by Mr. J. Thomson (fig. 25), the shell was provided with spiral processes, and is a Meristella. Nor could it, for the same reason, be classed with Zereératula. In certain localities it abounds in the condi- tion of internal casts, which, in Prof. M‘Coy’s words, “show in the entering [dorsal] valve, two sub-parallel, approximate, longitudinal sulci, marking the inner [outer] edges of the muscular impressions, and with a fainter sulcus between them, left by the slight mesial septum; two pits near the beak, left by the apophyses, strong. Receiving [ventral] valve with two strong dental lamellz, one each side of the beak, and a slight indication of a mesial septum: a few straight, once- or twice-branched impressions of the pallial vessels on each side.” The shell is usually of an elongated oval form; but some examples are almost circular, and even occasionally, though rarely, a little wider than jong. I cannot consider Prof. Schmidt correct in placing JZ. angustifrons, M‘Coy, among the synonyms of Afrypa cassidea, Dalman (Silurische Formation von Ehstland, Nord- Livland und Oesel; Archiv, &., 1858, p. 209). Position and Locality. At p. 230 of ‘ Siluria’ (1859) this fossil is quoted by Salter as one of the characteristic fossils of the Lower Llandovery rocks. In Scotland it occurs by millions in a greenish and rusty-coloured sandstone at Mullock Hill, Dalquharran, Craighead ; as well as in other localities of the Girvan Valley, Ayrshire. Mr. Salter traced this species in the Llandovery formation in South Wales, along the borders of South Wales, at Rhayader, Cilgwyn, and Pen-y-lan, near Llandovery ; also near Builth. MerRIsTELLA DIDYMA, Dalman (sp.). Pl. XII, figs. 1—10. TEREBRATULA ? DIDYMA, Dalman. K. Vet. Akad. Handl., p. 146, pl. vi, fig. 7, 1828. ATRYPA — Hisinger. Lethea Suecica, p. 77, pl. xxii, figs. 7 a, 4, ¢, 1837. TEREBRATULA SACCULUS, Von Buch. Ueber Terebrat. ; Akad. Berlin, 1834, p. 90 (not T. sacculus, Martin). SPIRIFERID A. 113 ATRYPA DipyMA, Sow. ‘Silurian System,’ pl. vi, fig. 4, 1839. TEREBRATULA CANALIS, Id. Ib., pl. v, fig. 18, 1839. ATRYPA DIDYMA (including 7’. canalis), Phillips and Salter. Mem. Geol. Surv., vol. ii, p- 277, 1848. TEREBRATULA, — Dav. Bull. Soc. Géol. Fr., 2nd ser., vol. v, p. 326, pl. vi, fig. 7, 1848. SPIRIFER DIDyMuUs, Bronn. Index Pal., p. 1176, 1848. Hemitayris Dipyma, D’Orb. Prodrome, vol. i, p. 37, 1849. ATRYPA CANALIS, Td. Ib., p. 40, 1849. HeEMITHYRIs DIDYMA, U‘Coy. Brit. Pal. Foss., p. 201, 1852. — UPSILON, IZd. Id., p. 207, 1852. WaLDHEIMIA ? CANALIS, Gray and Woodward. Cat. Mollusca Brit. Mus., part iv, p- 77, 1853. SPIRIGERINA DIDYMA, Schmidt. Archiv Naturk. Liv- Ehst- und Kurlands, vol. ii, p. 210, 1858. RHYNCHONELLA — Salter. ‘Siluria,’ 2nd edit., pl. xxii, fig. 15, 1859. SPIRIGERA — Lindstrim. Ofv. K. Vet. Akad. Férhandl., p. 361, 1860. Spec. Char. More or less pentagonal, usually longer than wide; posterior margins converging into a small tapering imcurved beak; front narrowed, and emarginate or notched. Valves either regularly and moderately globose, or with a narrow mesial sulcus, commencing in each valve at a short distance from the extremity of the beaks, and extending to the front. No foramen visible. Interiorly, the spiral processes are directed outwards, and attached to the hinge-plate of the dorsal valve. Surface smooth, marked here and there by more or less strongly indented concentric lmes of growth. Shell-structure impunctate. ‘Two specimens measured— Length 11, width 10, depth 7 lines. ‘mage (0S 2 e,, Obs. This small species has, since 1827, been referred to no less than nine different genera! Being possessed of spiral processes, it could not be classed with Zerebratula, Riynchonella, or Hemithyris ; and it appears to me that its affinities are more with Meristella or Athyris than with any of the other genera to which it has been allotted. Paleontologists are also now generally of opinion that Zerebratula canalis, Sow., must be placed amongst the synonyms of the shell under description; and Mr. Salter and myself ascertained the matter beyond doubt by comparison of the original fragmentary valve upon which the so-termed 7. canalis had been founded, the specimen being preserved in the Museum of the Geological Society. Von Buch was in error in placing it amongst the synonyms of Zerebratula sacculus, these shells belonging to different genera; and therefore Bronn was right in stating that Zerebratula didyma, Von Buch, was a different shell from 7. didyma of Dalman. Not being acquainted with the Zerebratula corculum of d’Eichwald, I cannot say whether Prof. Bronn was correct in referring it also to Dalman’s species. I am not quite certain that the shell figured by Barrande as Zerebratula canalis, Sow. (Silur. Brachiop. Bohmen, Pl. XVI, fig. 13), really belongs to Sowerby’s 15 114 BRITISH SILURIAN BRACHIOPODA. T. canalis or to Dalman’s 7. (?) didyma ; and I think the valve attributed to 7. canalis by M. de Verneuil in the great work on Russia (Pl. IV, fig. 11) must belong to another species. Hemithyris upsilon of M‘Coy, from Pwllheli, appears to be MJeristella didyma. [ Salter. ] | Meristella didyma varies in shape, as may be seen in the series of specimens figured in our Plate; but is always easily distinguishable from J. tumida, M. angustifrons, and M. Circe, on account of the furrow which in most specimens divides the valves into two distinct lobes. It has neither fold nor sinus. Position and Locality. Meristella didyma occurs in the Llandovery, Wenlock, and Ludlow Rocks. In the Upper Llandovery at Glansevin, Llandeilo. In the Wenlock Limestone of Dudley. At Hay Head, Rushall Canal near Walsall, Benthall Edge, and Ledbury. Wenlock Shale of Falfield, Tortworth. In the Upper Llandovery of Eastnor Park, Malvern, and May Hill; and also at Pwllheli (as Hemithyris upsilon), according to Mr. Salter. At Usk, Abberley, and Sedgley, in the Aymestry Limestone. Ledbury, Herefordshire, in Wenlock Limestone. Messrs. Phillips and Salter found this shell at Ridge Hill, Abberley district, in Aymestry Limestone : South-west of Hazle and Wootton Farm (Woolhope district); at Llangibby; and North of Camp Wood in Aymestry Limestone; and at Dowlas in Lower Ludlow (Usk district). Cwm-craig-ddu, Upper Ludlow (Builth district). North of Trichrug. Storm Hill Lodge. Pont-ar-y Llechau, and Golden Grove, Dafaddfa-Uchaf, in the Llandeilo district. On the Continent it occurs at Ostergan, Gothland, at Solva (Ural), and im several localities in Oesel and Ehstland. MeristeLLa niTIDA, Hall (sp.). Pl. X, figs. 28—382. TEREBRATULA L&VIUSCULA, Sow. Sil. Syst., p. 631, pl. xiii, fig. 14, 1839. AtrYPA NITIDA, Hall. Report Fourth Geol. District New York, pl. xii, fig. 5, 1843; and Palzont. New York, vol. ii, p. 268, pl. lv, figs. 1 a—o, 1852. TEREBRATULA LHVIUSCULA, Bronn. Index Paleont., p. 1240, 1848. — niTipa, Dav. Bull. Soc. Géol. Fr., 2nd ser., vol. v, p. 327, pl. iii, fig. 37, 1848. _ — De Verneuil. Ibid., p. 346. ATRYPA — D Orb. Prodrome, vol. i, p. 40, 1849. TEREBRATULA ? L&vrIuscuLA, Salter. Siluria, 2nd edit., pl. xxii, fig. 14, 1859. RHYNCHONELLA NITIDA, Id. Ibid., p. 545, 1859. SprricEra? — Lindstrim. Ofv. K. Vet. Akad. Forhandl., p. 361, 1860. Spec. Char. Shell small, ovate, longer than wide; valves almost equally convex ; beak small, incurved over umbone of dorsal valve ; no foramen observable; greatest width of shell about the middle, broadest anteriorly, tapering to the extremity of the beak. Valves almost equally and moderately convex; lateral and frontal marginal line SPIRIFERID@. 115 nearly straight. There is no regular fold or sinus, but a small depression sometimes exists at and near the front in the ventral valve. Surface smooth, marked by concentric lines of growth, more or less strong at intervals. Shell-structure impunctate. Two specimens measured— Length 7, width 5, depth 33 lines. Se ee Oés. Having carefully examined and compared the original example of Zerebratula leviuscula, Sow. (in the Museum of the Geological Society), with the American Aérypa nitida, Hall, 1 soon became convinced that Sowerby’s specimen was a small and obscure shell, with no definite characters, and therefore should not hold priority over Prof. Hall’s well-determined species. Sowerby’s specimen possesses the fibrous impunctate shell- structure of Athyris or of Meristella; and in one of these genera it will, no doubt, require to be classed. I am also somewhat uncertain whether the Bohemian 7. Circe of Barrande be more than a variety of the shell under description; but, as there may exist still some uncertainty about the matter, and as I have not had the advantage of being able to examine many specimens of these shells, I will describe this last under a separate head, while repeating that our British examples attributed to Barrande’s species seem to pass by so many gradations into J. nitida, that it is possible they are all variations of a single species. The only difference I can observe in the two is, that in MZ Circe there appears to exist a small but deepish sinus towards the front in the dorsal valve of many specimens, which gives to the frontal line an elevated convex curve ; but this is also visible, to a lesser degree, in many examples of undoubted J. nitida; and in his description of Atrypa nitida, Prof. Hall does not fail to observe that “the dorsal valve (our ventral) is sometimes marked, near the base, by a longitudinal depression.” I had noticed the presence of spirals in 1847, and recorded the observation in the ‘Bulletin Soc. Géol. France; and Lindstrém has also detected them in a Gothland specimen. In his description of 4. zztida, Prof. Hall observes :—‘ It is usually remarkable for its smooth surface, interrupted only by a few lines of growth on the middle or towards the base, the finer concentric strie being obsolete or invisible to the naked eye. In some individuals the shell becomes thickened near the base [front], and marked by very strong lines of growth.” Position and Locality. Meristella nitida occurs in the Wenlock Limestone and Shale at the Rushall Canal near Walsall, at Dudley, Benthall Edge, at Tynewydd, Llan- dovery (the original locality), in Wenlock Shale. In Ireland it has been found by the Geological Survey in the Upper Silurian at Cahirconree, on the west side of County Kerry. It occurs also in Gothland. In America, according to Prof. Hall, it is found in every part of the Niagara group of New York State, being most abundant at Lockport ; also at Wolcott, in Wayne County, &c. 116 BRITISH SILURIAN BRACHIOPODA. MeristTeLLa Circe, Barrande (sp.). Pl. X, figs. 33—35. TEREBRATULA Circk, Barrande. Sil. Brach. Bohm.; Nat. Abhandl., vol. i, p. 37, pl. xvi, fig. 6, 1847. == — Dav. Bull. Soc. Géol. Fr., 2nd ser., vol. v, p. 326, pl. iii, fig. 27, 1848. SPIRIGERA — D Ord. Prodrome, vol.i, p. 43, 1849. ATHYRIS — Salter. Siluria, 2nd edit., p. 542, 1859. ?SprrtceRA — Lindstrém. Ofv. K. Vet. Akad. Forhandl., p, 361, 1860. Characters. Shell small, rhomboidal, longer than wide, greatest width about the middle, from whence it gradually tapers to the extremity of a small incurved beak, and anteriorly towards the front, which is much narrowed, and sometimes slightly indented. Valves almost equally and moderately convex, not often gibbous; margin-line nearly straight laterally, convex or curved in front. There is no real fold, but a-small rounded elevation occurs near and at the front of the dorsal valve, with sometimes a small groove along the middle, and there is a corresponding depression or sinus in the ventral valve. Surface smooth, marked only by concentric lines of growth. Shell-structure fibrous, impunctate. Spiral processes attached to the hinge-plate of the dorsal valve. Two specimens measured— Length 7, width 5, depth 4 lines. 53. 50 es ee ee ee Obs. The spiral processes in this species (or variety) have been figured by Barrande and by myself, in 1847 and 1848. : Position and Locality. Meristella Circe occurs in the Wenlock Limestone of Dudley; at Hay Head, and the Rushall Canal near Walsall ; in the Woolhope Limestone at Hastnor Park, Malvern, &c. _ In Bohemia it was found by Barrande near Prague; and Lindstrém thinks he has obtained it at Gothland. MeristeLua? Macuarent, Haswell. Pl. XII, fig. 20, a, 6. Merista Macrarent, Haswell. Silurian Formation of the Pentland Hills, p. 30, pl. ii, fig. 16, 1865. Spec. Char. Shell small, pentagonal, narrowed anteriorly, and slightly indented in front. Ventral valve much deeper and more convex than the opposite one, and with an angular sinus or sulcus extending along the middle. Beak pointed, much incurved over the umbone of dorsal valve, with sharply defined beak-ridges. No foramen visible. Dorsal 7 SPIRIFERID/. by valve slightly convex, with a depression along the middle. Surface smooth, marked only by concentric lines of growth. Interior unknown. Length 5, width 4, depth 23 lines. Obs. Only one imperfect specimen having been found (by Mr. Haswell, in the Wenlock Shale of Deerhope Burn, Pentland Hills), 1 am much puzzled in which of two or three genera it should be located, and I have provisionally left it with Meristella ; for, although several species of MJerzsta, with the arched or shoe-lifter process occur in the Silurian rocks of Bohemia, I am not acquainted with any species of the genus in our British Silurian rocks, unless the small shell, Pl. XXI, figs. 28 and 29, may be referred to it. MERISTELLA? orassa, J. de C. Sow. (sp.). Pl. XIII, figs. 1, 2, 3. ATrypa crassa, Sow. Sil. System, pl. xxi, fig. 1, 1839. SPIRIFERA PERCRASSA, M‘Coy. Brit. Pal. Foss., p. 194, 1852. ? PoRAMBONITES CRASSA, Morris. , Cat. Br. Foss., p. 143, 1854. ATRYPA? — Salter. Siluria, 2nd edit., pl. ix, figs. 6, 8, 1859; Mem. Geol. Surv. Great Brit., p. 363, 1866; Spirifera percrassa, ibid., p. 276. Spec. Char. Longitudinally or transversely oval, somewhat sub-rhomboidal, widest about the middle; anteriorly the sides present a gentle inward curve, while the front is narrowed and slightly rounded; posteriorly the sides form broad convex curves, and the beak is small and incurved. Valves nearly equally convex (?) and smooth; a very slightly rounded lobe exists near the front in the dorsal valve, to which corresponds a small depression in the ventral valve. The interior of the latter is considerably thickened ; while from under the extremity of the beak the dental plates diverge widely for a short distance on either side of the beak, and end anteriorly with a hinge-tooth, thus leaving between them a rather deep fissure, of which the sides slope inwards to unite along the bottom of the beak. On leaving the dental projections, these plates converge for some distance to diverge again, until they reach about two thirds or more of the length of the valve, so that towards the middle of the shell they partly surround the muscular area. These dental plates have not a great elevation, but are wide at their base. The lateral portion of the valve, between the dental plate and the margin, is exceedingly thick, and is marked by several obliquely indented grooves, which exist also, but with less depth, on the surface of the interior of this valve that is not occupied by the dental plates and muscular areas. In the interior of the dorsal valve a small hinge-plate is divided by a narrow groove; under this a slightly elevated median septum extends to about half the length of the shell, dividing the muscular scars, which form a pair on either side of the 118 - BRITISH SILURIAN BRACHIOPODA. septum, and are separated one from the other by smaller oblique ridges. Two specimens measured— Length 12, width 11 lines. Se On tss. aaa Ods. ‘This shell does not appear to have been well understood by those who have described it, nor can the genus to which it belongs be yet with certainty determined. It is not a Spirifer,as Prof. M‘Coy and one or two others have supposed it to be; for, besides the interior arrangements not being those of that genus, it possesses no area; the lateral portions of the beak being regularly rounded off from the margin of the fissure. The fissure itself is also in a great measure filled up by the incurved beak or umbone of the dorsal valve. ‘Then there appears no sufficient or valid grounds that I can perceive for placing it with Porambonites, nor with Atrypa; and consequently the genus to which it bears most affinity would appear to be Meristel/a or Athyris. At p. 230 of < Siluria’ (2nd edit.) Mr. Salter states that Atrypa crassa is probably of the same genus as the so-called Rhynchonella angustifrons, and that Terebratula furcata, Sow. (Min. Conch., Pl. 21, fig. 16), one of the same group, is an Upper Llandovery species. Now, I have already shown that the so-called Hemithyris or Rhynchonella angustifrons of M‘Coy and Salter is either a Meristella or an Athyris, and is possessed of spiral lamellae for the support of the oral arms, as in those genera; and consequently it is highly probable that Meristella crassa was similarly provided. My description of the interior is taken from gutta-percha moulds, made from internal casts ; but, as casts alone have been hitherto found, I will here reproduce the description Prof. M‘Coy has given of them—* Casts of the receiving (ventral) valve show two very strong slits of the dental lamella, converging so as to meet in the rostral part, enclosing the large triangular foramen, and again diverging in their anterior part, reaching to within one fourth the length of the anterior margin: each side with about six thick radiating ridges (ovarian ?), and two or four on the middle lobe, all obscurely forking at the margin. Cas/s of entering (dorsal) valve show two thick diverging dental pits at the beak, a wide shallow mesial depression, with an obscure crucial arrangement of four angular ridges defining the muscular impressions.” I have not myself seen a perfect bivalve specimen of this common species, and the figures given in the ‘Silurian System’ are very imperfect. Although I have not been able, from want of sufficient material, to offer complete figures of the exterior, I believe those I have given of the interior may be considered an improvement on those hitherto published, and will assist the student in any further researches he may make with reference to the species. , Position and Locality. Meristella crassa is common in the Lower Llandovery, and rare in the Upper Llandovery or May Hill rocks. Mr. J. de C. Sowerby describes it from Cefn Rhyddan, Llandovery. Mr. Salter mentions it from the Upper Llandovery rock of Bogmine, near Shelve; and from the Lower Llandovery of Cyrn-y-brain, and of SPIRIFERID A. 119 Mathyrafal, near Meifod, North Wales, from which last place Prof. M‘Coy also quotes it. He also states that it has been also found in the green conglomerates (Lower Wenlock) of Moel Seisiog, Llanrwst, Denbighshire (but Mr. Salter refuses to Rca it asa Wenlock species). MerisTELua ? FuRCATA, Sow. (sp.). Pl. XIII, figs. 7, 8, 9. TEREBRATULA FuURCATA, J. de C. Sow. Sil. Syst., pl. xxi, fig. 16, 1839. RayncHonetLa — Morris. Cat. Brit. Foss., p. 146, 1854. oe — Salter. Siluria, 2nd edit., p. 545, pl. ix, fig. 12, 1859. Spec. Char. Shell small, elongate-oval ; ventral valve convex, smooth, beak incurved ; interior much thickened, while from under the extremity of the beak the dental plates diverge widely for a short distance, and terminate anteriorly with a hinge-tooth; from thence they again converge for a short distance, leaving between them a deep concave space or fissure. At the anterior base of this hollow two deep grooves commence, and gradually diverge; while a raised central ridge divides them for some distance, to become itself afterwards divided into two branches, with a depression between them towards the front. There exist also in the thickened lateral portions of the valve two or three oblique furrows, all of which are in relief in the casts— Length 43, width 4 lines. Obs. Of this species I am unfortunately acquainted with some internal casts of the ventral valve only; and all my efforts to obtain a specimen showing the exterior of both valves, as well as the interior of the dorsal valve, have proved unavailing. Therefore our knowledge of this species, and of its true generic position, must for the present be necessarily very incomplete and unsatisfactory. I have left it provisionally with Meristella, as suggested by Mr. Salter, who has seen many specimens in working over the collections of the Geological Survey; but it may require to be removed hereafter, when the other parts of the shell shall have been discovered. In the mean time I have given carefully enlarged drawings of the interior of the ventral valve. Mr. J. de C. Sowerby describes his shell as “Orbicular, very convex, smooth; beak of one valve much curved; interior marked with several furrows, and a forked channel in the middle.” This is the aspect of the cast; the forked channel being the cast of the divided central ridge. (See above.) Position and Locality. This species has been obtained from the Upper Llandovery sandstone, one and a half mile south of Bogmine, Shelve, Shropshire. In the Survey Museum are some specimens found by Mr. Salter at Morrell’s Wood, near the Wrekin. Sir R. Murchison’s original specimens may be seen in the Museum of the Geological Society. It is, says Mr. Salter, a common species. 120 BRITISH SILURIAN BRACHIOPODA. MERISTELLA? SUBUNDATA, M Coy (sp.). PL XT tgs 4g, oc HeEMITHYRIs suBUNDATA, M‘Coy. Brit. Pal. Foss., p. 207, pl. iu, 1852; and Annals Nat. Hist., 2nd series, vol. viii, p. 394, 1851. RHYNCHONELLA — Salter. Siluria, 2nd edit., p. 545, 1859. HEMITHYRIS — Schmidt. Archiv Naturk. Livlands, &c., vol. ii, p. 214, 1858. Spec. Char. ‘Transversely broad-oval; valves almost equally convex; beak very small, apicial angle 140° near the apex; lateral margins straight; front raised into a rounded wave, from which in the large valve a wide shallow mesial depression extends half-way to the beak, with a corresponding elevation in the small valve in some specimens extending to the beak.’ Length 11, width 15 lines. Ods. I have reproduced Prof. M‘Coy’s diagnosis and figures, as he had greater opportunity of studying the shell than I have had; but I have ventured to remove it from Henithyris, as its affinities appear to me to tend more towards those of the Athyride than to the Rhynchonellide, of which the term Hemithyris is no more than a synonym. In this alteration I am supported by Mr. Salter, who has devoted so much attention to the British Paleeozoic genera and species. ‘The shell is smooth, and remarkable for the smallness of its beak. It is not much unlike some compressed examples of Meristella tumida. Position and Locality. It is stated to be very common in the schists and limestones of Mathyrafal, South of Meifod, Montgomeryshire ; also in the slate of Alt-ffair-ffynnon, Llanfyllin ; and at p. 545 of ‘Siluria’ it is quoted from the Llandovery rocks. At p. 275 of vol. ui of the ‘Memoirs of the Geological Survey,’ its locality is more exactly given by Mr. Salter as Pen-y-craig, Llangynyw, near Mathyrafae, Meifod, North Wales (in the Lower Llandovery). Prof. F. Schmidt mentions having found this species in the Lower Silurian of Baltischport. Genus Atuyris, M‘Coy (= Spiricera, D’ Orbigny). For the characters of this genus readers are referred to my ‘Monograph of British Permian Brachiopoda,’ p. 20, &c., and to the ‘ Devonian Monograph,’ p. 113, &c. Although the genus Merista proper, with its shoe-lifter-shaped plate, is represented abundantly in the Upper Silurian rocks of Bohemia, I am not (as before said) at present acquainted with any British Silurian species that I could refer to that genus. SPIRIFERIDA. 12] Atuyris opovata, Sow. (sp.). Pl. XII, fig. 19; and Pl. XIII, figs. 5, 5 a. ATRYPA OBOVATA, Sow. Sil. Syst., pl. viii, fig. 9, 1849. TEREBRATULA — Sow.? Barrande. Silur. Brach. Bohmen, p. 28, pl. xv, fig. .8, 1847. —_— — Dav. Bull. Soc. Géol. France, 2nd ser., vol. v, p- 327, 1848. ATRYPA — Phillips and Salter. Mem. Geol. Surv., vol. ii, pt. 1, p. 278, 1848. Atuyris ? — Salter. Siluria, 2nd edit., p. 542, pl. xxii, fig. 16, 1859. Spec. Char. Almost circular, a little wider than long; valves nearly equally convex, with or without a small rounded elevation or fold near the front in the dorsal valve, to which corresponds a small depression in the ventral valve; beak small, incurved over the umbone of dorsal valve ; surface smooth, or rather marked by concentric and slightly raised lines of growth. Length 5, width 53, depth 33 lines. Obs. All my efforts to obtain a sight into the interior of the dorsal valve of this species have proved unsuccessful; but I feel almost certain that it was provided with spiral lamelle. I have received from Dr. Holl the interior of the ventral valve, of which a figure will be found in Pl. XIII. British examples of this shell are small, and do not attain the dimensions of the specimen figured from Bohemia by Barrande. I am also not certain whether the species under description and Atrypa compressa, Sow., should not be considered as a single species. It is true that Sowerby informs us that in his 4. obovata there exists a small marginal elevation at the front in the dorsal valve, forming a rounded sinus in the ventral; but, although this may be the case in some specimens, it was not so in many examples that have fallen under my notice, so that I am very much inclined to regard them as one species, or as varieties only ;’ but as this does not appear to be the view taken by the generality of paleontologists, I shall provisionally leave them under separate heads. They present the same dimensions; but 4. compressa is stated to be equivalve, and 4. obovata to be inequivalve. 1 In the ‘Annual Report of the Trustees of the Museum of Comparative Zoology,’ Boston, 1863, Mr. Louis Agassiz states that “The differences noticed among animals of the same species do not con- stitute varieties, but are individual differences, similar to those which may be noticed among the different individuals of the same family among ourselves. Any attempt to group them under a few heads, as varieties, fails as soon as large numbers of specimens are considered. What have been generally described as varieties by naturalists are extreme individual differences, occurring more frequently in certain species than in others; but, like all others, presenting the same indefinite peculiarities, which forbid one consider- ing them as in any way typical. This shows that individuality constitutes the most prominent feature of the organic kingdom, and is by no means confined to the human family.” 16 122 BRITISH SILURIAN BRACHIOPODA. Position and Locality. It occurs plentifully in the Lower Ludlow rock at Mathon Lodge, west flank of Malverns ; also at Dog Hill, Ledbury. The type specimen of this species, as well as that of 4. compressa, Sow., may be seen in the Museum of the Geo- logical Society of London. M. Barrande found this species near Prague, in Bohemia. Atuyris compressa, Sow. (sp.). Pl. XII, figs. 16—18. ATRYPA COMPRESSA, Sow. Sil. Syst., pl. xiui, fig. 5, 1839. _— — M‘Coy. Syn. Sil. Foss. Ireland, p. 39, 1846. ? TEREBRATULA, — Barrande. Silur. Brach. Bohmen, p. 47, pl. xiv, fig. 3, 1847. —_ _ Dav. Bull. Soc. Geol. France, 2nd ser., vol. v, p. 327, 1848. RHYNCHONELLA = Salter. Siluria, 2nd edit., p. 544, pl. xxii, fig. 22, 1859. ? SPIRIGERA — Lindstrim. Ofvers. K. Vet.-Akad. Férhandl., p. 361, 1860. Spec. Char. Shell small, orbicular, somewhat transversely oval or circular; valves moderately and nearly equally and evenly convex, rather compressed, without fold or sinus ; front line slightly rounded on the margin; beak in ventral valve very small, and much incurved over the umbone of the opposite valve, so that the minute aperture is but rarely exposed. Surface smooth, marked more or less deeply with concentric, slightly projecting lines of growth; shell-structure fibrous, not punctured. , Length 53, width 6, depth 3 lines. Obs. I have stated my reasons above (p. 121) for thinking that this and A. obovata may probably belong to a single species. In one or two examples a shallow or slight median depression was observable near the front, as may be noticed in a specimen from Dudley, in Gray’s collection, British Museum (fig. 17). Although I have not been able to examine the interior of any of our British examples, it is very probable, if not certain, that the animal was provided with spiral lamella for the support of its oral arms; and if the specimen figured by M. Barrande from Bohemia be really referable to the shell under description, we possess positive evidence of their occurrence. Mr. Salter, at p. 544 of ‘Siluria,’ 2nd edit., places 4. compressa in the genus Rhynchonella; and at p. 542 A. obovata, doubtfully, in Athyris. I think, however, that they both belong to the same genus, if not to the same species. Position and Locality. A. compressa occurs in the Wenlock limestone near Dudley, and the Woolhope limestone at Woodside and Nash, Presteign; also in the Upper Silurian (Wenlock) shales of Hare Hill, in the Pentland Hills. In Ireland M‘Coy thought he obtained it from the Lower Silurian schists of Tirnaskea, Pomeroy, Co. SPIRIFERID A. «128 Tyrone, but Mr. Salter assumes that this is a mistake, and that 4. compressa is strictly Upper Silurian. On the Continent M. Barrande found the species in Upper Silurian ‘rocks near Prague. Dr. G. Lindstrém is not quite certain if it really occurs at Gothland. AtuHyris ? DEPRESSA, Sow. (sp.). Pl. XII, figs. 11—15; and Pl. XIII, fig. 6. ATRYPA DEPRESSA, J. de C. Sow. Sil. Syst., pl. xiii, fig. 6, 1839. TEREBRATULA DEPRESSA, Dav. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 327, 1848. ATRYPA —_ Phillips and Salter. Mem. Geol. Surv., vol. ii, part 1, p. 277, 1848. RHYNCHONELLA — Salter. Siluria, p. 544, pl. xxii, fig. 17, 1859. HeMItTuyris — M‘Coy. Brit. Pal. Foss., p. 201, 1852. SPIRIGERINA CORDATA, Lindstrim. Ofvers. K. Vet.-Akad. Férhandl., p. 363, pl. xii, fig. 3, 1860. Spec. Char. Transversely obovate, widest anteriorly ; front nearly straight; dorsal valve varying in degree of convexity, but deeper than the opposite valve; mesial fold of moderate width, very slightly raised above the general convexity of the valve, and divided by a central longitudinal sulcus; the lateral portions of the valve sloping rapidly to the margin, which in front is slightly incurved. On each of the lateral portions of the valve there exist two or three obscurely marked ribs or undulations. Ventral valve moderately convex, with a wide shallow sinus, extending from the extremity of the beak to the front, along the middle of which runs a small longitudinal rib, two or three rounded ribs being also present on the lateral portions of this valve. Beak pointed, small, and incurved, with a narrow triangular opening under its extremity, but rarely visible, owing to the incurvation of the beak. Lateral portions of the valve depressed towards the margin, which is sharp and slightly sigmoid. Surface of valves marked with concentric lines of growth. Shell-structure fibrous, not punctured. Length 5, width 63, depth 3 lines. Obs. This little species differs much in appearance under the varied conditions in which it is found. Usually it occurs either in the state of imperfectly preserved internal casts, or with only the inner layers of its shell still adhering to the internal mould. In this condition it was described and represented by Mr. J. de C. Sowerby in the ‘Silurian System ;’ and thus it appears, too, in Pl. XII, fig. 13, of this Monograph. In this state the slightly raised ribs of the perfect shell are rarely observable, the casts being obscurely marked with radiating lines, or by two or three furrows along the middle, as described by Sowerby; while the perfect shell (of which I have seen but two or three examples) is as described in our diagnosis: carefully enlarged illustrations of it will be found in Pl. XIII, fig. 6. The internal cast of the dorsal valve (Pl. XIU, fig. 15 a) shows well the four adductor or occlusor muscular scars, with a deep depression be- tween the posterior pair; and these are somewhat similar in their arrangement to those 124 BRITISH SILURIAN BRACHIOPODA. we have figured in an internal cast of the same valve of Athyris ambigua (‘ Monogr. Carbonif. Brach.,’ Pl. XVII, fig. 14). It is, however, with considerable hesitation that I group this shell with CLT NS, 285; Obds. In the preceding description are given details in connection with this species 136 BRITISH SILURIAN BRACHIOPODA. which need not be here repeated. Dr. Lindstrém informs us that to a variety of this species Prof. Lovén has given the MS. name of /amellosa. Position and Locality. Atrypa imbricata ranges from the Caradoc beds up to the Wenlock Limestone. It is common in the Wenlock Limestone at the Wren’s Nest, Dudley, at Benthall Edge, Wenlock Edge, Hay Head, near Walsall, Woolhope, &c. At Haverfordwest in Lower Llandovery beds; at Guilsfield, north-west of Welshpool, in the Upper Caradoc ; in the Bala beds of Keisley, near Dufton, in Westmoreland. In Scotland it occurs in the Caradoc (?) of Penhill. In Ireland at Killey, Pomeroy, and the Chair of Kildare, in Caradoc or Bala Limestone. Many more localities might be given; but as some confusion has taken place from the mixing of the two species, those localities only where the shell is positively known to occur are here recorded. ; It occurs in Gothland; and Prof. Schmidt states in his memoir already mentioned that 4. zmbricata occurs in the Lower and Upper Silurian rocks of the Baltic Provinces. It was also found in Bohemia by M. Barrande, in Btage E. ATRYPA ? HEMISPHERICA, J. de C. Sow. PI. XIII, figs. 23—380. ATRYPA HEMISPHHRICA, Sow. Sil. Syst., p. 637, pl. xx, fig. 7, 1839. — — M‘Coy. Syn. Sil. Foss. Ireland, p. 39. 1846. TEREBRATULA — De Verneuil. Bull. Soc. Géol. France, 2nd series, vol. iv, p. 654, 1847. ATRYPA — Phillips and Salter. Mem. Geol. Surv. Great Britain, vol. ii, part 1, p. 277, 1848. — _ Salter. Quart. Journ. Geol. Soc., vol. vii, p. 172, 1852. — — Hail. Paleeont. New York, vol. ii, p. 74, pl. xxiii, fig. 11 a, g, 1852. HEMITHYRIS — M‘Coy. Brit. Pal. Foss., p. 201 (also var. Scotica, p. 202), 1852. ATRYPA _ Salter. Siluria, 2nd edit., p. 100, fig. 4, and pl. ix, fig. 3, 1859. LEPTOC@LIA. — Hail. Report of the Regents of the University of the State Cabinet of New York, p. 33, 1857, and Pal. New York, vol. iii, p. 448, 1859. ATRYPA — Salter. Mem. Geol. Surv., vol. iii, p. 36, 1866. LEerTocelIa — Billings. Catalogue of the Silurian Fossils of the Island of ry Anticosti; Geol. Surv. of Canada, p. 48, 1866. Spec. Char. Shell small, sub-orbicular, usually wider than long ; ventral valve sub- hemispherical, evenly convex ; beak small, pointed, incurved, with a foramen beneath it. Dorsal valve very nearly flat and orbicular, slightly depressed along the middle; sides rounded ; frontal margin a little deflected. Hinge-line very obtuse, nearly as long as the breadth of the shell; with rounded cardinal angles. Surface of each valve ornamented with from twelve to eighteen simple rounded or sub-angular ribs, with concave interspaces SPIRIFERID &. 137 of about equal width; the valves are crossed at intervals by sharp concentric slightly raised undulating lines. Length 5, width 6, depth 23 lines. Obs. Sowerby describes this pretty little species as a beautiful fan-like shell, easily recognisable by its convex ventral, and almost flat dorsal valve. In Great Britain it occurs chiefly in the condition of external impressions and internal casts. The cast of the flattened dorsal valve shows an elongated slit, for a tooth, on each side of the beak between which a small triangular cardinal boss extends to a short distance, with deeper pits on either side. At the base of this prominence commences a_well-pronounced distinct median sulcus, which extends to about half the length of the valve (indicating in the shell the presence of a small median ridge); and on either side of the sulcus may be seen two impressions referable to the adductor or occlusor muscle. In the convex cast of the ventral valve on either side of the beak there exists a short diverging slit (produced by the dental lamina), and a little further on the pits left by the teeth. The muscular impressions are obscurely indicated. At p. 202 of his ‘ Brit. Paleeoz. Foss.’ Prof. M‘Coy states, “‘ As some modern writers have referred this shell to the genus Orthis, I have taken great pains to ascertain the characters of the hinge, as the obvious absence of the puncturing in the tissue of the shell rendered the reference to Orthis very doubtful in my mind; and I have convinced myself that there is no cardinal area whatever, but that the beak of the entering (dorsal) valve is simply pointed, hollow, and so much incurved only as to leave a wide triangular foramen beneath it; the hinge-characters, therefore, warrant the placing this singular shell in Hemithyris, with which also its tissue is identical.” Prof. Hall and Mr. Billings place Atrypa? hemispherica of Sowerby in the first- named author’s genus Leptocelia; and although it is very probable that the shell is neither an Atrypa, Terebratula, nor Rhynchonella (Hemithyris), and that we have not yet obtained a B permanent home for it, still, as the interior of the species is imperfectly known, and we have no positive certainty that it was similar to that of Leptocelia fiabellites—the type of Hall’s genus—it will, I think, be more prudent to follow Messrs. J. de C. Sowerby, —feptocwtia fabellites, after J. Hall’s figures. Salter and others, in leaving it for the present with - Interior of the dorsal valve, showing the cardinal process, crura, and crural plate, re- Atrypa. Having made moulds in gutta-percha from stored from cavities seen in a cast. a number of internal casts of the dorsal valve of 3: Interior of the ventral valve. specimens from the May Hil Sandstone of Anker- dine, obligingly collected for me by Dr. Holl, and where the species occurs by millions under the condition of external impressions and internal casts, I am able to detect several differences from what we observe in the cast of the same valves of Leptocelia flabellites, and which I will endeavour to describe. In the inside 18 138 BRITISH SILURIAN BRACHIOPODA. of the dorsal valve of Z. flabellites there exists a large prominent cardinal process, and on either side the inner socket ridges occupy a lower level. In the same valve of Atrypa ? hemispherica, on the contrary, instead of a large cardinal process there exists a small pit or depression, the inner socket-ridges projecting on either side, while the sockets themselves are likewise much smaller, and there is no evidence of the existence of crura or a loop as described to be present in Leptocelia flabellites. In A. ? hemispherica a blunt median ridge commences under the pit already described, and extends to about half the length of the valve; while on either side may be sometimes seen the scars left by the adductor or occlusor muscle. I have also observed differences in the interior of the ventral valve of the shell under description and that of ZL. flabellites. It will, therefore, I think, be desirable to ascertain whether 4. hemispherica was possessed of crural processes and a loop before placing it in the new genus Leptocelia; and in order to assist the reader in the researches he may feel disposed to make on the subject, I will in a foot-note transcribe the description Prof. Hall has given of his genus.’ His figures are copied at page 137. ‘ Genus—LeEptoca ia, Hall. Regents’ Report on the State Cabinet, p. 67, 1857, and Pal. New York, vol. ili, p. 447, 1859. Type—L. flabellites, Conrad, sp., Terebratula and Rhynchonella, in part, of authors. Atrypa, Conrad, Hall, &e. “Shell inequivalved, variable in form, usually semioval or subcircular, transverse or elongate, plano- convex, or concavo-convex ; hinge-line sometimes equal to the greatest width of the shell. Ventral valve convex or subangular in the middle, with beak more or less extended, moderately incurved: foramen terminal, the lower side formed by two deltidial pieces ; dorsal valve flat or concave, or depresso-conyex. A mesial fold and sinus usually existing, but not often prominent. Structure of shell lamellose or fibrous, not punctate. a> “ Valves articulating by means of two strong teeth in the ventral, inserted into sockets in the dorsal valve, which are mainly excavated in the base of a strong cardinal process ; teeth converging, denticulate with corresponding denticulations in the sockets. Muscular impressions marking a large oval or flabelli- from area, with a thin median septum; adductor imprints small. “The dorsal valve is marked by a strong cardinal process, at the base of which, on either side, are the deep oblique dental fossets; and from the inner margins of these proceed the crural processes, supported below by thickened plates which extend obliquely for a short distance towards the middle of the shell bordering the muscular impressions. The muscular impression forms a suboval space divided througly the middle by a low median septum. The crura, in their extension, are united in a flattened disk, which, terminates at its remote extremity in an acute point; and on the centre of the cardinal side of the disc there is a slender process extending downwards, while near the junction of the crura with the disc there is, on each side, a slender descending process continued into the cavity of the ventral valve. The cardinal process, in its central portion, is thickened at first and divided in the middle, but, in old shells, gradually filling the passage to the foramen, and sometimes by a prominent point in the centre entirely dividing the passage. The hinge-line is often much extended, and in the dorsal valve nearly straight to the cardinal angles. There is sometimes the appearance of a false area on the ventral valve, somewhat similar to Atrypa, the margin being thickened and grooved; but this does not appear to be a characteristic or constant feature. The specimens of the interior, which have fallen under my observation, usually preserve only the short crural processes ; and it is in one specimen alone, which is partially filled with crystalline matter, that distinct cavities can be seen corresponding with what I have described (see figure p. 137). The ie SPIRIFERID Ai. 139 I am by no means convinced that Prof. Hall is correct in considering the Zerebra- tula ? lepida of Goldfuss to bea type of his genus, and we know that another exceedingly compressed shell, Atrypa ( Orthis) lens, Phillips (Z. dividua, Schnurr), was possessed of spiral appendages (see Schnurr’s work on the Devonian Brachiopoda of the Eifel, pl. xxiv, fig. 2); and, indeed, as stated by Prof. Hall himself, the internal characters of his genus ~ have been determined mainly from the interior of Z. fiabellites ; and, consequently, until a further investigation into the interior dispositions of the other mentioned types has been effected, I would not venture to adopt as conclusive the generic identification proposed for our Silurian shell. Position and Locality. This shell appears to be characteristic of the Upper, and to be more rarely found in the Lower Llandovery beds: it is exceedingly abundant in certain localities. In the “Silurian System” it is mentioned from Ankerdine Hill, Abberley district ; Worcester Beacon, Malvern. I have seen it from May Hill and Huntley Hill, in the May Hill district. It covers large surfaces at Charfield Green, and Damory Hill, Michaelswood-Chace, Gloucestershire ; Tortworth; Merrick Wood, near Much Wenlock ; and Wooltack Bay in the Marloes district. In addition to these localities, in the 3rd vol. of the ‘Memoirs of the Geological Survey,’ Prof. Ramsay and Mr. Salter mention Llandeilo, Llangadock, Builth, Presteign, Longmynd, Church Stretton, Norbury, Chirbury, and Malvern, in the Upper Llandovery rocks. In Scotland it is exceedingly plentiful in rocks of the Llandovery age, at Saugh Hill; Lower Thrave, and Braes, in sandstone ; at Ardmillan in a blue limestone, &c., all in the Girvan district, Ayrshire. ’ For Ireland Prof. M‘Coy mentions the following localities :—In calcareous shales at Ardaun, Cong, Co. Galway. Very common in the sandstone of -Blackwater Bridge, Leenane; Boocaun, Cong; Cappacorcogue, Cong; Glencraff; Kilbride, &c., all in the County of Galway, and in Upper or Lower Llandovery rocks. In America Prof. Hall states it to be very abundant in the upper green shale crystalline matter was first deposited upon these internal organs, which have subsequently almost entirely decomposed, leaving in the cavities fragments of the substance showing the original form of the crura and appendages. “The shells of this form have been described as Teredratula, and more recently have been included with Rhynchonella, from which they differ conspicuously in the great inequality of the valves and the extension of the hinge-line, as well as in their internal structure. I have, therefore, referred to this genus the Leptocelia (Atrypa) disparilis of the Niagara group, the Terebratula lepida of Goldfuss. The T. sub- lepida and T. Duboisii of Murchison, de Vern., and de Keyserling (Geol. of Russia and the Ural Mountains). The L. concava and L. imbricata, in the Lower Helderberg group, are analogous forms which have been referred to this species. “The Atrypa hemispherica of Murchison is apparently a characteristic form of this genus, as well as A. planoconvexa, both from the Clinton group. The internal structure, however, has been determined from the species of the Oriskany Sandstone and Lower Helderberg specimens, but mainly from the former.” 140 BRITISH SILURIAN BRACHIOPODA. (Clinton group) at Rochester; near the Ridge Road in Ontario; at Central’s Mill, and Sodus and Wolcott in Wayne County. In some beds it forms thin calcareous layers in which the shells preserve a beautiful silvery lustre, as it does in the Tortworth district. M. de Verneuil refers to the vast abundance of this shell both in Europe and in America. Mr. Billings states it to occur in the Middle Silurian at South-west Point, the Jumpers, and East Point in the Island of Anticosti. Atrypa? Scotica, M‘Coy (sp.). Pl. XIII, fig. 31. ATRYPA HEMISPHERICA, Sow., var. Scotica, M‘Coy. Salter, Quart. Journ. Geol. Soc., vol. vii, p. 178, pl. ix, fig. 12, 1851. HEMITHYRIS — var. Scotica, M‘Coy. Brit. Pal. Foss., p. 202, pl. i, H, fig. 10, 1852. Spec. Char. Shell small, transversely sub-orbicular, wider than long, or elongated oval. Ventral valve moderately and evenly convex; beak small, pointed, and incurved. Dorsal valve very slightly convex, with a small longitudinal depression along the middle. Sides and front rounded. Surface of each valve ornamented with from about twenty to twenty-five small narrow ribs, usually bifurcated, the valves traversed by concentric lines of growth. ‘Two specimens measured— Length 5, width 6, depth 2 lines. 2» Oso» On oe Ss Obs. Prof. M‘Coy himself suggests that “this may ultimately prove a distinct species, in which case the varietal name may become specific.” He points out that it is distinguished from the type species (4. hemispherica) by the ribs being more numerous (usually about twenty to twenty-four), considerably narrower, less prominent, and less regular in size and distinctness, and often irregularly forked ; a character seldom or never seen except at the inner edge of the flat valve in the typical specimens. ‘The receiving (ventral) valve is also slightly more carinate, and the entering (dorsal) valve not so perfectly flattened, and with a faint trace of a wide undefined, mesial hollow.” Having examined a very great number of specimens of true 4. hemispherica, as well as of A. Scotica, 1 have preferred to retain them as distinct: in the first the ribs are fewer in number and simple, while in all the specimens of the second that have come under my notice they were, as the Professor says, much more numerous, narrower, and bifurcated. The question with reference to the genus may, however, still remain undetermined. Position and Locality. t occurs in vast numbers in the greenish Lower Llandovery sandstone of Mullock Quarry, above Dalquharran, near Girvan, Ayrshire. SPIRIFERID A. 14] Arrypa? Grayu, Davidson. Pl. XIII, figs. 14—22. TEREBRATULA GRayil, Davidson. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 331, pl. iii, fig. 33, 1848. RHYNCHONELLA — Salter. Siluria, p. 250, Foss. 57, fig. 3, 1859. SprriceRIna?’ — Lindstrém. Gottland’s Brachiop., p. 364, 1860. Spec. Char. Shell small, transversely oval, irregular, and abruptly twisted, from one half of the shell being more elevated than the other. Valves almost equally convex without fold or sinus, but with a median depressed line only; beak of ventral valve small, moderately incurved, and truncated by a minute circular foramen, which is separated from the hinge-line by a small narrow deltidium in one piece; beak-ridges sharply defined, leaving between them and the hinge-line a narrow triangular area. Surface ornamented by concentric ridges, from which rise narrow (frill-shaped) projecting laminz, longitudinally plaited. Interior not known ; excepting the cardinal process in the dorsal valve. Length 5, width 7, depth 3 lines. Obs. This strangely shaped shell, of which I have seen about forty specimens, does not appear to have exceeded the dimensions above given, and is generally much smaller. It constantly assumes the same character, that is to say, having always its right or left half twisted higher or lower than the other; and consequently both valves are longitudinally divided along the middle by a sharply curved line. When well preserved, the surface exhibits a variable number of rows of projecting concentric lamine, as in Atrypa reticularis, but much narrower ; the surface is smooth in worn specimens only. It is well known that some species of Ahynchonella, and of other genera, at times or even normally assume a similarly twisted appearance. My endeavours to procure specimens showing internal characters have proved fruitless; and I cannot therefore determine exactly the genus. It is evidently not a Zerebratula, for its shell is fibrous and impunctate ; its surface-ornament is not that of a Rhynchonella. Lindstrém has placed it (with a mark of interrogation) in Aérypa (Spirigerina), where we may provisionally leave it. The hinge and cardinal process are peculiar; the last projecting considerably, as seen in fig. 21. Whether or not it possessed spiral lamellz is uncertain.! Position and Locality. Atrypa ? Gray has been hitherto found in the Wenlock Limestone only. It occurs at Hay Head, near Walsall ; some rare specimens have also been procured near Dudley. Dr. Lindstrém finds it at Wisby, in the Island of Gothland, and there it appears to be rare. 1 Prof. Hall, to whom I sent specimens of this species, thinks that spires will be ultimately found ; but that it is neither a Rhynchonella, an Atrypa, nor an Athyris, though it may be allied to the latter ; it is so different from any American forms. 142 BRITISH SILURIAN BRACHIOPODA. Famity—RHYNCHONELLID A. Genus—PENTAMERUS, Sowerby, August, 1813. For the description of this genus, see the “General Introduction,’ ‘Monograph of British Fossil Brachiopoda,’ vol. i. PentamMERUS Kwnicutu, Sow. Pl. XVI, figs. 1—3; Pl. XVII, figs. 1—10; Pl. XIX, fig. 3. PentaMeRus Knicuti, Sow. Min. Conch., vol. i, p. 73, pl. xxviii, August Ist, 1813. — AYLESFORDII, Sow. Ibid., pl. xxix, 1813. — Kyniewtu, Jd. Sil. Syst., p. 615, pl. vi, fig. 8, a, 6, ¢, 1839. _ — F. A. Roemer. Verstein. Harzgebirges, pl. v, fig. 16, 1843. “= — ? Barrande. Naturwiss. Abhand., vol. i, p. 107, pl. xxi, fig. 3, 1847. — — Dav. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 333, 1848. == — Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 292, 1848. = — Bronn. Index Pal., p. 944, 1848. — —_ D Orb. Prodrome, vol. i, p. 41, 1849. — _— F. A. Remer. Beitr. Geol. Kenntniss d. nord-westl. Harzge- birges, p. 59, 1850. 7 _ M‘Coy. Brit. Pal. Foss., p. 209, 1852. -— — Gruenewalt. Verst. Silurisch. Kalkstein von Bogosslowsk ; Mém. Sav. Etrang., vol. vii, p. 26, pl. iv, fig. 15, 1854. — — S. P. Woodward. Manual of the Mollusca, p. 228, fig. 143 ; pl. xv, fig. 22, 1854. _ ~— Morris. Cat. of Brit. Foss., p. 142, 1854. — — De Verneuil. Geol. of Russia, vol. ii, pl. vii, fig. 1, 1845. — — C. Giebel. Silur. Fauna d. Unter-harzes, p. 46, 1858. oa — Salter. Siluria, 2nd edit., pl. xxi, fig. 10; and var. Aylesfordii, fig. 11, 1859. — — Billings. Canad. Journ., p. 59, fig. 90, 1861. — — Salter. Explanat. Sheets, 160, &c., Geol. Surv. Ireland, p. 13, 1863. Spec. Char. Shell impunctate; ovate, or longitudinally oval, sometimes obscurely pentagonal, and as wide as long; more rarely transversely oval and wider than long; the young form at times trigonal. Ventral valve ventricose or more convex than the opposite one, evenly rounded or flattened along the middle; beak large and very much RHYNCHONELLID @. 143 incurved, fissure triangular, commencing under the extremity of the beak, and extending to the hinge-line; no area or deltidium. The lateral portions of the beak merge gradually into the edge of the fissure; beak-ridges slightly defined, leaving between them and the fissure a rather wide, smooth, convex space. Dorsal valve oval, and more or less gibbose, with a slight longitudinal depression along the middle; marginal line slightly flexuous, almost straight or gently convex in front. Surface of valves ornamented by numerous simple angular ribs, rarely exceeding two lines in width at their greatest breadth; one or two sometimes bifurcating. The dental plates of the ventral valve, converging in a trough-like shape for half the depth of the valve, then coalesce into a strong median plate, which extends two-thirds or more down the valve. In the dorsal valve two much smaller, separate, longitudinal septa, with a narrow space between them, extend to about half the length of the valve, and to which the socket-plates converge and joi, as in the corresponding plates of the ventral valve. Three specimens measured— Length 4 inches 9 lines, width 3 inches 2 lines, depth 2 inches 10 lines. Le ae: aa (SOM) a Bie Fe ie Uleetenila eo 3s BS SHIRL, VAi6s}} bated Metros) BBs ins a) Se Ge eee Oés. In his charmingly written book, ‘A Summer’s Ramble amongst the Hebrides,’ that distinguished paleontologist, Hugh Miller, remarks how preferable it is to hazard the risk of being even tediously minute in descriptions, to incurring the danger of being inade- quately brief in them. But, “alas! for purposes of exact science, rarely are verbal descriptions other than inadequate.” The truth of this is by myself constantly felt; and as it is impossible to draw up a description fully answering to the shape of every speci- men, the general characters must be more particularly aimed at in the written definition ; and, as much as possible to make amends for my own shortcomings, I have endeavoured to speak to the eye by the means of numerous illustrations. While stating how variable are the forms assumed by this species, | may remind the student that in Pl. XVI and XVII he will find the principal modifications assumed by P. Knightii, and I leave to his imagination the task of connecting them by every gradation of shape. P. Knightii was well figured by James Sowerby in 1813; and his description,’ although somewhat 1 Thus Sowerby states, ‘‘The septa in the flat valve extend to its edge” (this is not correct, for they extend only half way) ; ‘“‘they are near each other and parallel. The septum in the other valve divides the beak ; the divisions extending to the edge of the shell form a kind of double beak, much resembling the horny part of the toes of a pig’s foot, and leave an angular hollow within the curve: the stone that fills this hollow commonly separates easily, and may at first sight be taken for a third valve of a triangular carinated form. The edge of the deep valve appears to extend over that of the flatter one; the length of the curve, from the apex to the edge, is often six inches. About half a mile up the River Teme, near Downton Castle, the dell is bounded by two steep rocks, approaching to each other; and the parts of the land above are level and alluvial, as if a lake had been there before the present chasm in the rock. On the southern rock (a dark-grey limestone) these extraordinary split shells are found, and are situate’ about twenty feet above the level of the river. I am greatly obliged to T. A. Knight, Esq., of Downton, 144 BRITISH SILURIAN BRACHIOPODA. quaint and defective, shows that the author was acquainted with the internal characters of the shell, and regarded these of sufficient importance for the creation of the excel- lent genus Pentamerus. His Pentamerus Aylesfordii, however, is certainly no more than a transverse variety of the species under description. The ribs on the surface of P. Knighti ave at times regular in width. The facility with which the shell separates along the middle is due to the two continuous longitudinal septa in the ventral valve, which are well exhibited in Pl. XVI, fig. 2. It is probable that the space left free between the V-shaped plates, or central chamber, was occupied by the digestive organs, while the large lateral spaces were filled up by the ovaries and the spiral arms. Of Pentamerus Knightii the largest example I have seen (found by Dr. Lloyd at Mocktree, near Ludlow, and now in the Ludlow Museum) is represented in Pl. XVI. P.. Knightii is exceedingly common in certain localities, and all our museums possess many excellent examples. In the Swedish island of Faré, in the Baltic, the species does not appear to exist, but is replaced by an allied and equally large form, named P. tenui- striatus, by Walmstedt.* Position and Loeality. P. Knightii occurs rarely in the Wenlock and Upper Ludlow formations ; but it is exceedingly common in the Aymestry limestone at Mocktree, near Ludlow, where I have picked it up on several occasions ; at Aymestry, in Herefordshire, and at Leintwardine, Shropshire. It occurs near Sedgley, near Wolverhampton; and Prof. Phillips obtained it at Ridge Hill Farm, in the Abberley district, and at Bodenham, in the Woolhope district: all in Aymestry limestone. In the Museum of the Geological Survey in London there are some specimens from the Wenlock limestone of Walsall and Wenlock Edge. In Ireland it occurs east of Ferriter’s Cove, Dingle, Co. Kerry; but no specimen has yet been discovered in the Upper Silurian rocks of Scotland. On the Continent, it has been found in Russia, Bohemia, &c. for the first specimen of this shel] in 1809. I have since received specimens from A. Carlisle, Esq., which have much assisted in illustrating its curious structure, collected by him when on a visit to the gentleman mentioned. A. Aikin, Esq., had observed this formation, and the discovery of the under shells, and mentioned them to me at the meeting of the Geological Society in February, 1812.” 1 Pentamerus Volgicus, De Verneuil, is another large species, very nearly allied to P. Knightii, found in various localities in the Ural Mountains. At p. 115 of the great work on the ‘Geology of Russia and the Ural Mountains,’ De Verneuil details the differences observable between his species and our own P. Knightii ; but 1 have not yet been able to detect them, as clearly as my friend De Verneuil, in a specimen of the species sent me by Prof. F. Schmidt. The ribs in the Russian specimens of P. Knightii figured by M. V. Gruenewalt are much finer than on any of our British examples. RHYNCHONELLID. 145 PENTAMERUS GALEATUS, Dalman (sp.). Pl. XV, figs. 183 —23. ATRYPA GALEATA, Dalman. Kongl. Vetens. Acad. Handlingar., p. 130, 1827. TEREBRATULA GALEATA, Von Buch. Ueber Terebrat., 1834. TRIGONOTRETA CASSIDEA, Bronn. Lethea Geog., vol. i, p. 78, pl. ii, fig. 9, z, 1835 (non 7. cassidea, Dal.). ATRYPA GALEATA, Hising. Lethzea Suecica, p. 76, pl. xii, fig. 1, 1837. —_ — Jd.deC. Sow. Sil. Syst., pl. xii, fig. 4, 1839. PENTAMERUS GALEATUS, Conrad. Geol. Rep. New York, 1840. TEREBRATULA GALEATA, De Castelnau. Terrain Sil. de l’Amérique du Nord, p. 39, pl. xiv, fig. 4, 1843. PENTAMERUS GALEATUS, Murch., Vern., and Keys. Geol. Russia, vol. ii, p. 120, pl. viii, fig. 3, 1845. — — De Keyserling. Wiss. Beobacht. Reise in das Petschora-land, p. 236, 1843. é TEREBRATULA GALEATA, Roemer. Verst. Harzgeb., p. 19, pl. xii, fig. 25, 1843. — 2? Tumipa, Eichwald. Leth., 202; Bull. Moscou, vol. xix, p. 110, 1846. PENTAMERUS GALEATUS, De Verneuil. Bull. Soc. Géol. France, 2nd ser., vol. iv, p. 690, 1847. — — Barrande. Naturw. Abhandl., vol. i, p. 465, pl. xvi, fig. 5, 1847. _ — Bronn. Index Pal., p. 944, 1848. — — Dav. Bull. Soc. Géol. de France, 2nd ser., vol. v, p. 333, 1848. — — Phillips and Salter. Mem. Geol. Survey, vol. ii, part i, p. 291, 1848. f = — D’Orb. Prodrome, vol. i, p. 41, 1848. — — _ Quenstedt. Uandb. Petrefactenk., pl. xxxvi, fig. 39, 1851. _ — M‘Coy. Brit. Pal. Foss., p. 208, 1852. — _ Schnur. Eifel Brachiopod., in W. Dunker und H. v. Meyer’s / Paleontographica, vol. iii, p, 196, pl. xxix, figs. 2, a—é, 1853. — . —_ C. Giebel. Silur. Fauna Unterharzes, 1853. — — Morris. Catal. Brit. Foss., p. 142, 1854. — — Gruenewalt. Mém. Sav. Etrang., vol. vii, p. 28, pl. v, fig. 18, a—c, 1854. — — Bigsby. Quart. Journ. Geol. Soc., vol. xiv, p. 410, 1858. — — Salter. Siluria, 2nd edit., pl. xxi, figs. 8, 9, 1859. —_— _— Helmersen. Geol. Bemerk. Reise in Schweden und Nor- wegen; Mém. Acad. Se. St.-Petersbourg, 2nd ser., p. 309, 1858. _ — D’Eichwald. Uethzea Rossica, Période Ancienne, vol. i, pl. xxxv, figs. 19, 20, 1859. a _ Hall. Pal. New. York, vol. iii, p. 257, pl. xlvi, fig. 1 a—z ; pl. xlvii, fig. 1 a—m, 1859. = — Lindstrém. Proc. Royal Acad. Stockholm, p. 365, 1860. = = Salter. Explan. Sheets 168, &c., Geol. Surv. Ireland, p. 13, 1863. 19 146 BRITISH SILURIAN BRACHIOPODA. Spec. Char. Shell varying much in shape, longitudinally (obscurely) ovate or sub- pentagonal, not uncommonly about as wide as long, or transversely elliptical ; sometimes almost circular, very convex, almost globose. Ventral valve gibbose, greatly arched, much deeper than the opposite valve, with a broad, slightly elevated mesial fold, commencing - at about the middle of the shell, and extending to the front, but sometimes entirely absent, the valve being then uniformly convex; beak large, ventricose, and usually so much incurved as to overlie, and even come into contact with, the umbone of the dorsal valve, so that the triangular fissure beneath the beak is but rarely exposed; the lateral portions of the beak slope gradually, by a convex curve, to the edge of the fissure. Dorsal valve often almost circular; posteriorly, evenly convex and gibbous until it reaches about the middle of the valve, when a broad and more or less deepened sinus commences, which extends to the front; lateral margins flexuous, front depressed into a concave wave. Surface of quite young shells sometimes smooth, and marked only by concentric lines of growth; but generally one, two, three, or more obtusely angular ribs commence at about the middle of the valves, and extend along the fold and sinus, the lateral portions remaining smooth. In other specimens, on each of the lateral portions of the valve two or more ribs exist in the vicinity of the margin, and are often of unequal size and width ; while as many as from nine to fifteen are sometimes present on each valve, some of these being occasionally partly divided along the middle or bifurcated. Shell impunctate. In the interior of the ventral valve the dental plates converge, and form a curved, trough- like process, or long, spoon-shaped chamber, while the vertical median septum extends to about one third of the length of the valve, and in its upper part becomes united to the conjoined dental lamellz. In the interior of the dorsal valve two much longer longi- tudinal septa, with a small free space between them, extend about two thirds the length of the valve; and to these the lengthened socket-walls or plates converge, and, when joined, form two more or less developed plates, inclined outwards, corresponding with the trough-like plates of the ventral valve. Three specimens measured— Length 19, breadth 18, depth 16 lines. mee (Papeete dl &: Aerie Sets 39-2 Lay 1 oye) ASS ee ames Oés. This very variable and exceedingly far-spread species has been much more fortunate than many of its congeners; for, although it has been once or twice placed in the genera Zerebratula, Trigonotreta, and Atrypa, almost every author has retained for it the designation galeatus, given to it by Dalman in 1827; for I believe that M. Gruene- walt can scarcely be correct while identifying the Pentamerus Wurmii of F. A. Romer with the Atrypa galeata of Dalman; and although identified as the Atrypa cassidea of Dalman by Bronn in 1835, the mistake was subsequently corrected by Bronn himself at p. 1288 of his ‘ Lethaa Geognostica.’ Pentamerus galeatus is easily distinguished from P. Knightii both by its external shape, and especially by internal differences, the median septum being shorter and conjoined, supporting but half the V-shaped chamber; and NN aye S ps RHYNCHONELLID@. 147 a glance at their respective figures will easily explain this. It appears to be more variable in shape than P. Knightii. The specimen upon which Dalman founded his species had twelve to fifteen ribs on each valve, and the fold and sinus developed. In some specimens the valves are almost equally and uniformly convex, without fold or sinus ; and while other examples are either smooth or have ribs obscurely marked, some specimens are strongly ribbed. All these variations have been drawn in our plate, and have been selected from several hundred examples. Position and Locality. 'The vertical range and geographical distribution of Pentamerus galeatus is very considerable; for it is common to the Wenlock, Middle Ludlow, and Devonian formations. It abounds in the Wenlock limestone and Upper Wenlock shales near Walsall and Dudley.’ Messrs. Phillips and Salter enumerate the following localities :—In Wenlock limestone and shale at Storrige, Ledbury, Eastnor Park and Castle, Dunbridge Wood, east of Ledbury, Brock Hill section, in the Malvern district; at Hill End, and Callow Farm, Abberley district ; east of Canwood, Checkley Common, Dormington Wood, Lindels, &c., in the Woolhope district; the Rock, May Hill district; Swansea Road and Golden Grove, Llandeilo district. In the Lower Ludlow, at Brock Hill section, Malvern district, and Hill End, Abberley district; in the Aymestry limestone, west of Rilbury, Malvern district ; Llanbadoc, Beech Hill, Ty-Newydd, Usk district. In Ireland, it occurs, with P. Knightit, in the Croaghmarhin (Aymestry) beds, Ferriter’s Cove, Co. Kerry (Salter), and at Cahirconzee, west side (Mus. Geol. Survey, Treland). It has not been hitherto positively detected in Scotland; but some casts found in the Llandovery rocks, in the Girvan district, Ayrshire, bear much resemblance to those of the species under description. Abroad, it has been found in many countries and localities. In the Island of Goth- land, it occurs in the “ Middle Gothland” of Lindstrém, and thence Dalman’s type was 1 Mr, Allport has expressed a just regret that it is not a more common practice for collectors to be particularly careful in affixing the exact localities to their specimens; as, by making use of the term “Dudley,” very much confusion has already arisen as to the Silurian fossils obtained from that district. He remarks that, with regard to deductions made by comparing the fossils from the Dudley shale, sup- posed to represent the Lower Ludlow formation, he does not attach much weight to such comparison, as the rocks near Ludlow are of an arenaceous character, indicating that they were deposited under very different circumstances from the mud beds found near Dudley. Mr. C. Ketley, in an interesting paper in vol. ii, p. 105 (Dec., 1865) of the ‘Transactions of the Dudley and Midland Geological and Scientific Society,’ seems to consider that, on the whole, the fauna of the upper shale, over- lying the Dudley limestone at East Wren’s Nest, Parke’s Hall, &c., and which is so well known for the variety and beauty of its fossils, has a closer relationship to the limestone below it than to that of the rocks above. He adds, “Of Brachiopoda the upper shale has twenty-nine species, twenty-four of which are also found in the limestone below. The Lower Ludlow of Ludlow has ten species, of which six are common io the limestone and upper shale also, and two of them to the upper shale.” As it must be confusing to some who have not access to the locality, but seek information as to its rocks and fossils, to find this shale named “Lower Ludlow” by one authority and “ Wenlock Shale ” by another, Mr. 148 BRITISH SILURIAN BRACHIOPODA. obtained. M. de Verneuil describes it from black Devonian (?) limestone at Ustkataf, between Jurjusensk and Simsk, in the south of the Ural Mountains, and from Bogoslofsk, in the South Urals. M. Barrande found it in the Upper Silurian rocks of Bohemia ; and Prof. Hall states, at p. 259 of vol. im of his ‘ Paleontology of New York,’ that “this Ketley has drawn up the following Table as a guide, which, although not quite complete, is here reproduced, as it illustrates a subject upon which further careful observations should befmade: Wenlock Limestone, Upper Shale, Lower Ludlow of BRACE ORD Dudley. Dudley, the Ludlow District. Athyris tumida) :s:e5 Shih Eee ee Bee: 55 descent Bees ee — — DG WISI foc ben sheaecneten ea eee reed oe 55, tack st eee — == , MMGUIE bcs tyccc, aces ter eee shu Ritdeiasticehce nena np Pa Duis Se GSE — — Wilsons: Anke er eeereeteee Pig bMS 5 Hit Ae) | chadeot cat eee — Lepteena ‘transversalis’ 5,170, .0 (ute. 5 semene RSE, oes aa NAb chy 5 ceee eee —_— Orthis biloba’.20. 5353.0. ee eee SG BAAD compen asr 55 Wh len See ee — ——. elegantiala ‘¢., .4.2 dca csebe Oa epe eee Be Sate Se oe oak We ge i ae ene ike Fes a3 — — var. obicularis ............ SP nc tae cohen ee aan 55) «, gale Sek eRe Se _ —= “hybrid. 3,-2.8 oaks canteen tat eae the See ee ener) Peo sasctosd seca _- Strophomena, depressa :.....-......ene0---50-- 4) 2h ee ee Pree i PL Le ©. <4 — eugly plas. f22. 8. 2d Snes ee ba’ GT tsk eeteeeeee _— —— fil ose e121 eels Ae eee PAM re erie oo iy. 5 dRAL SSR —_ — AUT CUA EAE Lees eee eneene one as Peters o ees PE ee ots, a0 Chonetes leovigata wey. oie eee oe mmol) Ss Tee RN a MEE ee % — minimar. ..oe See ee FS ant Yee ts ame yy h hcae ticle da Sera ae — Discina Forbésit* 224i. Ste eee S50) WOO ay Secs Se ae = striata Vit AeA eases re erred Shy AO ae 0 TSetL. eee — —= PUR ACRE, Te on enieoeee: seeeereaete 3511, eae ohetoteiata ciate eraieteteters opt) seule siege ee Mentuiels = Lingula Symondsit ai ichoeeece es i AAR S ER PRINS 5 ies the RNS » af date 8) occ. es aca SER Rees Oe me a eee ey oo SA ae fh —, " Wewisit.g:2: 2.4... 22s oe eee ==> dos... Whee Be) AS, CEP SL etais Meee — Obolus*Davidsoni”. 94. 2.4-06e, eee eee. 5, ONSET, Renee PUD EPS, cameras — —— *EFAnsvOrsas” ©... h 0. acnde aetna ones a Asad dee eee PME er biker: Werke = At p. 430 of vol. iii of the ‘Geological Magazine’ (Sept., 1866), Dr. Holl observes that the above- mentioned Upper Wenlock Shales, notwithstanding the Wenlock aspect of their fauna, are considered, on good authority, to belong to the base of the Ludlow series. Mr. Salter refers the student to Sir R. Murchison’s often repeated statement, that the Lower Ludlow seems but to be an Upper Wenlock Shale ; where the former is represented by mud-stone the fossils are like those of the Wenlock. The Brachiopods have a greater range than the other shells. RHYNCHONELLID. 149 species is characteristic of the Lower Pentamerus-limestone (Lower Ludlow rock) of the Lower Helderberg group; and large masses of the rock are often made up of the broken and separated valves of this fossil. The more perfect specimens are obtained from the shaly limestone above the Pentamerus-limestone, Helderberg Mountains, Schoharie, Carlisle, Cherryvally; Herkimer Co., Catshill, Hudson, and numerous other places in New York State; Cumberland, in Maryland, Decatur Co., in Tennessee, and at numerous other points.” Prof. Schnur describes and figures Devonian specimens from the Eifel, which exactly resemble those from our Silurian deposits. PENTAMERUS LINGUIFER, J. de C. Sow. (sp.). Pl. XVII, figs. 11—14. ATRYPA LINGUIFERA, J. de C. Sow. Sil. Syst., pl. xiii, fig. 8, 1839. PENTAMERUS LINGUIFER, Davidson and De Verneuil. Bull. Soc. Géol. France, 2nd ser., vol. vy, pp. 332 and 346, 1848. — — Phillips and Salter. Mem. Geol. Surv., vol. ii, part 1, p- 277, 1848. — Buso, Barrande. Sil. Brach. Bohmen. Naturw. Abhandl., vol. ii, p. 116, 1847. — LINGUIFER, D’Orb. Prodrome, vol. i, p. 41, 1849. — — Morris. Cat. Brit. Foss., p. 142, 1854. — a F. Schmidt. Sil. Form. Ehstland, &c.; Archiv Naturk., &c., vol. ii, p. 212, 1858. oc -- Salter. Siluria, 2nd edit., pl. xxii, fig. 21, 1859. — ROTUNDUS, Lindstrém. Proc. Royal Acad. Stockholm, p. 365, pl. xii, fig. 6, 1860. Spec. Char. Sub-globose or orbicular, slightly wider than long, very rarely longer than wide; ventral valve gibbous, becoming very ventricose in old specimens, and espe- cially near the beak, and divided longitudinally along the middle by a narrow groove, as well as by a broad shallow sinus; beak moderately large and somewhat compressed along the middle, greatly incurved, so as almost to come into contact with the umbone of the dorsal valve, the small triangular fissure beneath being rarely exposed. Dorsal valve somewhat transversely oval, and divided into three portions by a moderately elevated mesial fold; front raised into rounded waves; surface smooth, marked only by a few concentric les of growth. In the interior of the ventral valve, the dental lamelle are developed into a small V-shaped cavity or chamber, extending freely into the cavity of the shell, and supported by a small vertical septum only at its posterior extremity. Inside the dorsal valve two very narrow septa, with a small intervening space, support two small plates, curving outward, and corresponding with those of the opposite valve. Two specimens measured— Length 9, width 10 depth 7} lines. Perr 9, bs Te 5, " U 150 BRITISH SILURIAN BRACHIOPODA. Obs. Pentamerus linguifer is a much smaller and more stumpy-looking species than P. galeatus, and is at once distinguished from it by having its mesial fold on the dorsal valve, whilst in Dalman’s species it occurs on the ventral valve; and the same applies to the sinus. It is also smooth, and the fold is often somewhat bent upwards towards its exterior, as seen in fig. 15 4 of our plate; but this is not always the case, as fig. 11 @ exemplifies. Its interior is also well distinguished from that of P. galeatus by the still smaller development of the conjoined dental lamellz, or the V-shaped chamber in the ventral valve, as well as in the smallness of the vertical septum which supports it. Dr. Lindstrém allows me to state that he considers his P. rotundus to be a variety or a small individual of the shell under description. Penxtamerus (Spirifera ?) Bubo, Barrande, though a somewhat larger shell, did appear to M. de Verneuil and myself, in 1847, to be the same as our P. linguifer. When quite young, the fold and sinus are scarcely apparent. Position and Locality. Pentamerus linguifer appears not to be restricted to the Woolhope and Wenlock limestones and the Wenlock shales ; Mr. Salter says it is plenti- ful in the Upper Llandovery conglomerates west of the Malvern Hills. Dr. Holl found it in the Woolhope limestone, and in the shale immediately above it, at Malvern, at the Pound and Crews Hill, both near Alfric, and four miles to the north of Malvern. I have picked it up at the Rushall Canal near Walsall, at Dudley, and along the Benthall Edge near Wenlock. ‘The Geological Surveyors have obtained it from Presteign and May Hill, as well as from other localities. Sir Roderick Murchison found it at Stumps Wood, Valley of Woolhope, and Delves Green, in Wenlock shale. It has not, to my knowledge, been found either in Scotland or Ireland, and Mr. Salter agrees with me. Abroad, it was discovered, for the first time, in the Upper Silurian beds of Gothland by Lindstrém, and in Russia by Schmidt. PENTAMERUS RoTUNDUS, J. de C. Sow. (sp.). Pl. XV, figs. 9—12. ATRYPA ROTUNDA, J. de C. Sow. Sil. Syst., pl. xiii, fig. 7, 1839. = — Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 279, 1848. HEMITHYRIS ROTUNDA, M‘Coy. Brit. Pal. Foss., p. 205, 1852. RHYNCHONELLA — Morris. Cat. Brit. Foss., p. 147, 1854. — — Salter. Silur., 2nd edit., pl. xxii, fig. 18, 1859. Spec. Char. Orbicular, or a little wider than long; sides and front rounded ; ventral valve smooth and moderately convex to within two thirds of the length of the valve, where a broad sinus commences and extends to the front; two or three rounded ribs occupy the sinus, while the lateral portions of the valve are either smooth, or orna- mented by two or three ribs on each side, but these do not extend further than to a very short distance from the margin; beaks small, and but little produced beyond the RHYNCHONELLID A. 151 umbone of the opposite valve. Dorsal valve rather more convex than the ventral, with a broad fold, which, commencing at the front margin, extends to a short distance only, and dies out. In some specimens three or four rounded ribs occupy the fold, the lateral portions of the valve remaining smooth; while, again, in other examples, two or three ribs exist also close to the margin, as seen in the ventral valve. Inside the ventral valve, a short septum supports a small V-shaped chamber, formed by the converging dental plates. Two specimens measured— Length 7, width 73, depth 5 lines. eer Oe Pe. Oe, Oés. It is with considerable hesitation that I place this species in the genus Penfa- merus, aS | am imperfectly acquainted with its internal characters; but Mr. Salter tells me it has a good septum and V-shaped chamber. The lines observable on the surface of some specimens, and-an internal cast in the collection of Sir-R. Griffith, described in the ‘Synopsis of Irish Sil. Fossils? by M‘Coy as Atrypa rotundata (fig. 12 of my plate), Jead me to believe it is a true Pentamerus. his fossil appears to vary to some extent in the presence or absence of ribs on the lateral portions of the valves. The beaks are also very approximate. Position and Locality. Murchison’s original example, which can be seen in the Museum of the Geological Society, was found in the Wenlock limestone of Wenlock Edge. It occurs also in the Woolhope limestone of the Malvern district less rarely. Prof. M‘Coy mentions it from sandstone at Alt Goch, Llanfyllin, Montgomeryshire (but no such specimen is in the Cambridge Museum; and it is probably a mistake). The Irish specimen described by M‘Coy is from Kilbride, Cong, Co. Galway, in May Hill sand- stone, or Upper Llandovery rock. PENTAMERUS OBLONGUS, J. de C. Sow. Pl. XVIII, figs. 1—12; Pl. XIX, figs. 1, 2. PENTAMERUS LEVIS, Sow. Min. Con., vol. i, p. 76, pl. xxviii, June or August, 1813. — oBLoneus, J. de C. Sow. Sil. Syst., pl. xix, fig. 10 (not fig. 12), 1839. — L&VIS, Sow. Sil. Syst., pl. xix, fig. 9, 1839. — oBLonevs, Hall. Geol. Report New York, p. 7, figs. 1—5, 1843. — — MCoy. Synop. Sil. Foss. Ireland, p. 38, 1846. — De Vern. Bull. Soc. Géol. France, 2nd ser., vol. iv, p. 690, 1847. _— L&vVIS, Phillips and Salter. Mem. Geol. Surv., vol. ii, part 1, p. 292, 1848. —_ OBLONGUS, Bronn. Index Pal., p. 945, 1848. —' — et Lavis, D’Orb. Prodrome, vol. i, p. 20, 1849. — — Salter. Journ. Geol. Soc., vol. vii, pp. 171, 172, 1851. — — Hall. Pal. New York, vol. ii, p. 79, pl. xxv, fig. 1, and pl. xxvi, fig. 1, 1852. 152 BRITISH SILURIAN BRACHIOPODA. PeNnTAMERUs OBLONGUS, M/‘Ooy. Brit. Pal. Foss., p. 211, 1852. = LEVIS, Id. Ibid., p. 209, 1852. — — (P. opionevs, Sow.), Morris. Catal. Brit. Foss., p. 142, 1854. — oBLONGUS, Bigsby. Quart. Journ. Geol. Soc., vol. xiv, p. 410, 1858. — — Salter. Siluria, pp. 100 and 230, fig. 2, and pl. viii, figs. 1, 2, 3, 1859. — — Eichwald. lethza Rossica, vol. i, p. 788, 1859. — ESTHONUS, Lindstrém. Proc. Roy. Akad. Stockholm, p. 365, 1860. — L&VIS (young of P. opLoneus), Salter. Mem. Geol. Survey, vol. iii, pp- 276 and 360, 1866. Spec. Char. Longitudinally oval or ovate, sub-trigonal ;. valves moderately and almost ~ equally convex, in some cases depressed; young shells evenly convex and smooth, older shells usually much trilobed. Mesial fold in dorsal valve tolerably broad, of small elevation, slightly depressed along the middle, while that on the ventral valve is rounded; beak moderately produced, and so much incurved as to touch the umbone of the dorsal valve ; fissure under the beak triangular, not much exposed; beak-ridges sharply defined, and leaving between them and the hinge-line a concave space (not a true area). Surface of valves smooth, with sometimes a few irregular furrows and concentric lines of growth. Inside the ventral valve a long vertical median septum, extending to two thirds or more of the length of the valve, supports the conjoined trough-shaped dental plates. In the dorsal valve two similar long, vertical septa, with a small free space between them, support two outwardly sloping plates, which correspond with the trough-shaped plates or V-shaped cavity of the opposite valve. Shell-structure impunctate. ‘Two specimens measured— Length 2 inches 7 lines, width 2 inches 3 lines, depth 1 inch 5 lines. 4: 8 Jf 8 ,, (BP. levis, Sow.) Obs. Prof. J. Hall, at p. 79, vol. ii, of his ‘Paleontology of New York,’ says, “Tt is impossible to give a description which shall be applicable to every form of a shell so variable as this species. In the smaller and medium-sized forms, in the Pentamerus-limestone of the Clinton group at Rochester and elsewhere, the shell has a general oval or ovate form, sometimes slightly trilobate at base; it is so much depressed that the thickness or depth of both valves is only about half the width. This proportion sometimes continues even in very old shells, the trilobate character of the base being often very conspicuous. In the majority of specimens, however, the valves become gradually more gibbous as the shells increase in size, and the trilobate character may be either preserved or entirely lost. In young shells usually the surface is marked only by con- centric striae, though in some instances distinct lines of growth give a more uneven surface, and this character becomes more prominent with increasing age. Although the general and prevailing form is oval or ovate, yet we not infrequently meet with forms that are rounded, and the ventral valve wider than long.” What Prof. Hall has observed with reference to the variations assumed by this shell in America will be found equally applicable to those that occur in Great Britain and in Europe; but none of the specimens RHYNCHONELLID &. 153 appear to be as large as some of those from Sweden and the Baltic provinces, if we are to consider Hichwald’s Pentamerus Esthonus (‘ Bull. Soc. Imp. Nat. Moscou,’ part i, p. 91, 1854, and ‘ Lethza Rossica, Période Ancienne,’ vol. i, pl. xxiv, fig. 23, 1859) as a synonym of the shell under description. I have myself seen specimens of the shell so named, sent to me by Prof. F. Schmidt, of St. Petersburg, and others given to me by Dr. Lindstrém from the Middle Gothland series of Carlsé, Klinteberg, and Bogeklint, without having been able to detect any difference, except the larger dimensions. Both Schmidt (p. 213 of ‘ Untersuch.’) and Lindstrém consider it questionable whether this shell is different from P. oblongus. At p. 789 of his ‘ Lethzea Rossica,’ d’Eichwald enters into long details in the endeavour to establish his view, that P. od/ongus and P. Esthonus are distinct species ; but the subject will require further examination. The British, Swedish, and Russian specimens of P. ob/ongus, as well as the generality of the American examples, have their valves moderately convex; but some very fine casts from Springfield and Dayton, Ohio, figured by Prof. Hall in pl. xxvi of vol. 11 of his ‘Pal. New York,’ are exceed- ingly gibbous, measuring 45 inches in length, 3 inches 3 lines in width, by about the same in depth; and the dimensions would be somewhat larger were the shell preserved. P. Esthonus also attained those dimensions both im length and width, but with a much lesser depth. ~ It is admitted now by most paleontologists that P. /evis, Sow., is the young of P. oblongus ; and if it were necessary to strictly adhere to the rules of priority, James Sowerby’s name, published in August, 1818, would perhaps require to be adopted in preference to that of od/ongus, given to the adult shell by Mr. J. de C. Sowerby in 1839; but when we read over Mr. James Sowerby’s unsatisfactory description,’ and look at his small, very incomplete figure, we think it preferable to preserve for the shell the now generally adopted and well-known designation of od/ongus. In 1839 Mr. J. de C. Sowerby described, it is true, in the ‘Silurian System,’ P. /evis and P. oblongus as distinct species ; but, judging from the single figured fragment of a ventral valve of P. levis, 1 « Pentamerus levis, J. Sowerby, ‘Min. Conch.,’ vol. i, p. 76*, tab. xxviii, fig. 2 (right-hand figure). August, 1813. [In our Pl. XIX, fig. 2, this illustration is reproduced. | “Spec. Char. Smooth, triangular, front rounding, beaks incurved. Much less gibbous than either of the last (P. Knightii and P. Aylesfordii), free from furrows, but having slight depressions over the septa; length generally less than an inch. Not having found this in a perfect state, although I have had stones including hundreds of specimens, I have been doubtful whether I ought to admit it. The Rev. D. Abbot, of Bedford, in May, 1812, was so kind as to bring me pieces of rolled limestone with three small dividing shells, from near Hopton Court, where he thought they appeared to be left by the sweil of the River Teme, and formed a bank three feet or more high. Sometimes, I think, there are two species in the stone, a smooth and a furrowed one [doubtless P. /iratus], but better chance than I have had must determine this; at the same time, one formation is distinctly characterised. The same stones contain the remains of Madrepores. The specimen figured is from Buildwas, Shropshire, collected by A. Aikin, Esq. In some specimens I perceive the remains of small Entrochi.”” Near Buildwas, Shropshire, the Wenlock limestone, and also the Pentamerus or May Hill sandstone, are well developed. (J. W. S.) 20 154 BRITISH SILURIAN BRACHIOPODA. he could not have had an opportunity of comparing a perfect example of it with the complete specimens of ?. od/ongus figured by him in the same plate. Position and Locality. Pentamerus vblongus would appear to be restricted to the Lower and Upper Llandovery rocks, and to be very much more abundant in the last- named formation. At page 229 of ‘Siluria,’ (2nd ed., 1859), it is stated that, “In the, Lower Llandovery rocks of South Wales P. wadatus and P. lens are everywhere found, P. globosus and P. oblongus being rare. In the upper series, whether in South Wales, Shropshire, or in the South of Scotland (as at Saugh Hill, near Girvan), P. odlongus is the prevailing fossil, occurring often in great banks, to the exclusion of all other fossils, but generally accompanied by the species just named. At May Hill and the Malverns P. /ens is by far the more common species; P. /ératus accompanies both these in the higher beds, and is the only one of the five species which ranges into the base of the Wenlock formation.” Among the English and Welsh Zower Llandovery localities may be named Cyrn-y-brain, Wrexham, Denbighshire; Cefn, three miles north-east of Welshpool, near Buttington ; also near Builth, and at Noedd-Grug and Llandovery, rare (J. W.S.). In the Upper Llandovery, Nash Scar (Presteign) ; Norbury, Bishops Castle, Stone Acton, Church Stretton, Chirbury, Hope Bowlder, and the Hollies, in Shropshire ;+ Pen Cerrig, Builth; Llangadoc; Wooltack Park, Pembrokeshire; Rose Market, near Haverfordwest, and Johnston ; Pen-y-lan ; Old Storridge, near Malvern. Prof. M‘Coy mentions Pwllheli, Carnarvonshire, and some other localities, giving the ‘ Upper Bala sandstone” and “Caradoc sandstone and limestone,’”’ such as that of Soudley and Horderley, Shropshire: in all these the May Hill sandstone is meant (J. W.S.). At p. 292 of the 2nd vol., part 1, of the ‘Memoirs of the Geol. Survey of Great Britain,’ Messrs. Phillips and Salter mention Fair Oaks, Gunwick Mill, and Howler’s Heath, Malvern district ; Ankerdine Hill, 4berley district ; May Hill, and Huntley, May Hill district ; Mandinam, Llandeilo district. In Scotland, it abounds in the Yellow Llandovery Sandstone of Saugh Hill and Penwhapple Glen, the conglomerates of Cuddystone Glen, and the blue limestone of Ardmillan and Penkill, near Girvan, Ayrshire. These are Upper Llandovery (Salter). In Ireland, it is stated by Prof. M‘Coy, in his ‘Synopsis of Silurian Fossils,’ to occur in the (Llandovery) sandstone of Boocaun, Cong, Co. Galway (very abundant in one bed), and in the sandstone of Cappacorcogue, Cong. A fine valve from this place will be found figured in our plate. Mr. Salter found it on the precipices west of Dingle ; and it occurs in the Lower Old Red conglomerates of that wild district, washed out in Devonian times from the May Hill rocks (J. W. 8.). Abroad, P. oblongus is equally abundant. In Russia Prof. P. Schmidt mentions 1 The masses of blue limestone full of the broad-arrow-like sections of the shell are the ‘ Jacobstones’’ of Shropshire. The line of the formation may be traced by the door-sills and well-steps of the cottagers. ; RHYNCHONELLID &. 155 Ruhde, Keskfer, Kattentach, Nudi, Jerwakant, Kerro, Fennern, Oberphahlen, Rostla, &c. In Sweden Dr. Lindstrém found it at Strora, Lilla Carlsé, Klienteberg, Bogeklint. It occurs also in the Upper Llandovery (?) in the neighbourhood of Christiania in Norway. In North America in the Clinton group at Rochester and elsewhere ; at Springfield and Drayton, Ohio; on the west side of the Mississippi River, &c. M. de Verneuil © observes that in North America, as well as in England, P. od/ongus occurs near the point of junction of the Upper and Lower Silurian groups, but in those beds which appear .to belong more properly to the Upper Silurian ; also that he found it at Richmond, Indiana, Galena (Illinois), at Seulchoix, Green Bay; also at Limekiln Island, and other islands of Lake Huron. Sir W. Logan has obtained it near the River Ottawa, and at Gaspé, in Canada. Dr. Bigsby obtained it further west and north; but it is not yet known, nor the band containing it, in the Arctic basin. PrnTamMeErus unpatvus, J. de C. Sow. (sp.). Pl. XIX, figs. 4—9. ATRYPA UNDATA, J. de C. Sowerby. Sil. Syst., pl. xxi, fig. 2, 1839. — — Phillips and Salter. Mem. Geol. Surv., vol. ii, part 1, p. 279, 1848. PENTAMERUS UNDaTUS, M‘Coy. Brit. Pal. Foss., p. 211, 1852. — _— Morris. Cat. Brit. Foss., p. 143, 1854. a — Salter. Siluria, 2nd edit., pp. 100 and 230, fig. 6 ; pl. viii, figs. 5, 6, 7, 1859. -— _— Id. Mem. Geol. Survey, vol. ui, pp. 276 and 360, 1866. Spec. Char. ‘l'ransversely oval; much wider than long; valves convex ; ventral valve most so, even gibbous, with a wide, sharply defined sinus commencing at the extremity of the beak and extending to the front, sometimes longitudinally divided along the middle by a slight elevation ; beak much incurved. Dorsal valve with a wide rounded fold of small elevation ; sides rounded, and slightly indented in front. Surface smooth, marked only by concentric lines of growth. In the inside of the ventral valve the V-shaped chamber formed by the union of the converging dental plates is small, as well as the vertical septum which partly supports it. Two specimens measured— Length 7, width 10, depth 6 lines. Pe bh LG lined. Obs. Of this fossil I have seen many internal casts and impressions, and never the shell itself. In one of these (fig. 8°) the vascular markings are beautifully defined, while in another (partly fractured) the outer surface of the converging dental plates, as well as a small area, are exposed (fig. 8). Again, in the casts of one or two examples may be seen a short longitudinal slit due to the vertical septum. Prof. M‘Coy informs us that “the internal plates are excessively small, but formed on the usual plan of 156 BRITISH SILURIAN BRACHIOPODA. Pentamerus. 1 observe,” he adds, “that in those species in which the plates are very small the outwardly curved marginal portion of the two diverging plates in the beak of the entering valve is unusually strong, giving to the casts the appearance of four slits in the beak, or of two slits and two oblique teeth.” Mr. Salter thinks that this species, as well as P. globosus, may possibly belong to Stricklandinia. Position and Locality. Casts of this species occur abundantly in the Lower and Upper Llandovery, but especially in the former. In the Lower Llandovery at Quakers’ Burial Ground, and Guilsfield, Welshpool; Pen-y-Craig; Mathyrafal, south of Meifod; Llangynyw, Montgomeryshire; Noeth Grug, Cefn Rhyddan, Cefn-y-Garreg, Llandovery ; Builth, Rhyader, &c.; Robeston Wathen and Haverfordwest, Pembrokeshire. In the Upper Llandovery at Llwyn-y-Wormwood, Mandinam, and Penlan, Llandovery; Builth, Llangadoc; Rosemarket, &c.; Malverns, Church Stretton. Woolhope beds, Buildwas (in ‘ Catalogue of Fossils, Museum of Pract. Geol.,’ p. 52 (probably P. dinguifer). In Ireland it occurs at Ballycar, Co. Clare (Mus. Geol. Survey, Ireland). I have not yet positively ascertained the existence of this species in Scotland, but a search for it should be made in some of the Llandovery localities in the Girvan district, Ayrshire. PenTAMERUS GLOBosuUS, J. de C. Sow. (sp.). Pl. XIX, figs. 10—12. ATRYPA GLOBOSA, J. de C. Sowerby. Sil. Syst., pl. xxii, fig. 26, 1839. — — Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 277, 1848. PENTAMERUS GLOBosuS, Vorris. Cat. Brit. Foss., p. 142, 1854. _ = Salter. Siluria, 2nd edit., pl. viii, fig. 8, 1859. _ — Id. Mem. Geol. Survey, vol. iii, pp. 276 and 360, 1866. Spec. Char. Circular, or slightly transverse-oval; globose, or, when old, sub- cuboidal, from the deflection of the front ; a very shallow undefined depression in the large or ventral valve forming a shallow wave in the margin towards the opposite valve, which is evenly convex, without a corresponding ridge; lateral and frontal margins rounded. In the cast of the ventral valve a long slit, extending to nearly half the length of the valve, indicates the position of the vertical septum supporting the trough-shaped chamber or converging dental plates. The surface of the cast is also irregularly marked by obscure ridges, Length 6, width 7 lines. Ods. I have never been able to procure the sight of more than a few internal casts of the ventral valve of this species; consequently, I can offer only a meager and incom- plete description. ‘The form of the shell is, however, so different from that of all the other species of Pentamerus occurring in Great Britain, that, judging from these incom- plete casts alone, it may be considered distinct. RHYNCHONELLIDS. 157 Position and Locality. P. glodosus is a rare fossil in either Upper or Lower Llandovery beds. In the Lower Llandovery it is found at Pen-y-Craig, near Meifod, North Wales, and Gorllwyn Fach, Llandovery. In the Upper Llandovery at Landeilo. Messrs. Phillips and Salter mention also localities in the Malvern district and the Llandeilo district; and Wooltack Bay, in Pembrokeshire. In addition to these, Prof. M‘Coy gives Beaver’s Grove, Bettws-y-Coed, North Wales ; but Prof. M‘Coy’s fossil is an Orthis, and from Caradoc rocks (J. W. S.). In Ireland, at Ballycar, Co. Clare, and Kilbride (Mus. Geol. Survey, Ireland). Since the publication of my description of the genus Pentamerus, at p. 95 of the “General Introduction,” ‘ Monogr. Brit. Brachiop.,’ vol. i, Mr. Billmgs has proposed to detach from it certain species, such as Pentamerus Viratus and P. lens, which he considers to present differences of sufficient importance for the establishment of a separate genus or sub-genus, for which he has proposed the designation SrrickLanpin1a. ‘The excellent genus Pentamerus, which was established by J. Sowerby as far back as 1813, was typified _ by the well-known P. Knightii, characterised as “an equal-sided, inequivalved bivalve, with one valve divided by a longitudinal internal septum into two parts, the other by two septa into three parts or valves; beaks incurved, imperforate.” We will now reproduce Mr. Billings’ description of his genus, as well as the reasons why he considers it distinct from Pentamerus. Genus—StRIcKLANDINIA, Billings. Stricklandia, ‘ Canadian Naturalist and Geologist,’ vol. iv, p. 182, April, 1859 ;? altered to Stricklandinia, ‘Can. Nat. Geol.,’ vol. vin, p. 370. “Gen. Char. Shell usually large, elongate-oval, transversely oval, or circular, some- times compressed; valves nearly equal; a short mesial septum in the interior of the ventral valve, supporting a small triangular chamber beneath the beak, as in Pentamerus ; ~ in the dorsal valve no longitudinal septa, spires, nor loop, yet observed ; the whole of the internal solid organs (so far as is yet known) consisting of two very short or rudimentary socket-plates, which support prolonged calcified processes for the support of the cirrated arms. In all the species known the ventral valve has an area more or less developed. The valves articulate by teeth and sockets. “This group of shells (Stricklandia), although closely related to, Pentamerus, differs from that genus in the following particulars :—1st. In Pentamerus the form is globular, _' Mr. Billings states, in the “Appendix” to vol. i of ‘The Paleozoic Fossils of Canada,’ that, as the generic name Stricklandia is preoccupied, he has changed it to Stricklandinia, He also informs me that the only species of Rensseleria (Hall) claimed by him as a Stricklandinia is Vanuxem’s Pentamerus elongatus. 158 BRITISH SILURIAN BRACHIOPODA. and the ventral valve much the largest. In Stricklandia the valves are nearly equal in size, and the form oval or heart-shaped, never globose. 2nd. In Pentamerus the dorsal valve has two, and sometimes three, well-developed longitudinal septa, which in most of the species sustain a small triangular chamber, as in the ventral valve. In Stricklandia these septa are not developed, and the triangular chamber is entirely absent. It might be thought that the difference between the short or rudimentary socket-plates of Stricklandia and the elongated mesial septa of Pentamerus should not be regarded as of sufficient importance to constitute a generic distinction, because it is only a difference in the extent to which identical parts are developed, the socket-plates of the former genus being a rudimentary state of the latter. When, however, we examine any group of closely allied genera, we find that all the grounds for separation consist in the various modifications of the same set of organs. ‘The difference in the degree of the development of an organ is not always a good character ; but when it is carried to such an extent that the whole form of the animal is affected in a particular manner, manifested in a number of species, then it becomes of generic value. If we take the several species of Stricklandia, and compare them with the ordinary forms of Pentamerus—such, for instance, as P. Knight, P. ga- leatus, P. Sieberi, P. acutolobatus, P. caducus, &c.—the difference in the external form of. the two groups is so remarkable that we should almost be warranted in separating them into two genera upon this ground alone; but when to the dissimilarity in the general form we add the difference in the internal structure, then there can be little doubt as to the correctness of the separation.” In the first volume of ‘ Paleozoic Fossils,’ published by the Geological Survey of Canada, p. 84 (1865), Mr. Billings further remarks—‘“ This genus was proposed by me to include such shells as those known in England under the names of Pentamerus Jens, P. liratus, and P. levis. They differ from Pentamerus in having the valves usually sub- equal, and no longitudinal septa or triangular chamber in the interior of the dorsal valve. Both valves have an area, but in the dorsal it is usually hnear, or only slightly exceeding the thickness of the substance of the shell in height. The ventral valve has usually a concave mesial sinus more or less developed, and the dorsal valve a mesial fold corre- sponding thereto. ‘The hinge-line in some of the species, such as in S. /evis and S. micro- camerus, have the hinge-line straight and much extended.’””* 1 Mr. Billings is in error in including Pentamerus levis in Stricklandinia, that shell being the young of Pentamerus oblongus. RHYNCHONELLID “i. 159 STRICKLANDINIA LIRATA, J. de C. Sow. (sp.). Pl. XX, figs. 1—13. Spreirer Lrratus, J. de C. Sowerby. Sil. Syst., pl. xxii, fig. 6, 1839. CaRDIUM MULTISULCATUM, Hisinger. Lethza Suecica, Supplementi secundi continuatio, p. 4, pl. xli, fig. 3, a, 6, 1842. Spreirer ovatus, M‘Coy. Sil. Foss. Ireland, p. 37, pl. iii, fig. 24, 1846. — muttisuLcatus, De Verneuil. Bull. Soc. Géol. France, 2nd ser., vol. v, p. 347, 1848. OrtHIs Lrrata, Phillips and Salter. Mem. Geol. Surv., vol. ii, part 1, p. 291, 1848. PENTAMERUS LIRATUS (SPIRIFER ovatus, I‘Coy), Salter, in Morris’s Cat. Brit. Foss., p. 142, 1854. — — Salter. Siluria, 2nd edit., pp. 100 and 230, fig. 3, 1859. — os Id. Mem. Geol. Surv., vol. iu, p. 360, 1860. Cyrtina? muttisutcata, Lindstrém. Pro. Roy. Acad. Stockholm, p. 360, 1860. STRICKLANDIA LiRaTA, Billings. Canad. Nat. and Geol., vol. iv, p. 434, April, 1859; Canad. Paleozoic Foss., vol. i, p. 84; Stricklandinia, Ap- pendix, p. 419, 1865. STRICKLANDINIA — Td. Catal. Sil. Foss. Anticosti; Report Geol. Surv. Canada, p. 45, 1866. Spec. Char. Generally transversely oval, sometimes longer than wide and ovate, or as wide as long; hinge-line nearly straight and shorter than the width of the shell; cardinal extremities angular; sides and front rounded. Valves almost equally and moderately convex, never gibbous. Dorsal valve more or less semicircular and trilobed, from the presence of a rather wide mesial fold of small elevation, which, commencing at the extremity of the umbonal beak, gradually widens as it approaches the front. Ventral valve with a wide shallow mesial sinus, originating at the extremity of the beak, and widening as it approaches the rounded front; beak small, incurved ; area narrow, with a triangular fissure in the middle. Surface of valves ornamented with numerous angular, regular, often bifurcating ribs, and concentric lines of growth. Inside the ventral valve an exceedingly short vertical septum supports a small wide triangular chamber, formed by the quickly converging dental plates. Inside the dorsal valve there is a narrow hinge- area, with a triangular depression in the middle, formed by two small rapidly converging (but not united) socket-plates, the inner extremities of which are prolonged into free, narrow, crura, sometimes three and four lines in length. Under these, near the umbo of the shell, are two elongated pear-shaped impressions, due.to the adductor or occlusor muscles, divided in the middle by a central ridge. Numerous pits (rough tubercules on the cast), probably ovarian markings, surround these scars. Three specimens measured— Length 2 inches 4 lines, width 2 inches 5 lines, depth 1 inch 1 line. me tees Ob. ENGIN SCRE Se LA ha ae ee 160 BRITISH SILURIAN BRACHIOPODA. Obs. The history of this variable and interesting species may prove valuable as exemplifying the difficulties at times experienced by naturalists in arriving at the correct identification of some of our most characteristic species. In 1839 J. de C. Sowerby first noticed the shell as a distorted cast of a large Sprifer or Orthis, nearly three inches in length, to which he applied the name of Spirifer liratus, giving as its locality the “Caradoc sandstone” and “ Llandeilo flags” of Marloes Bay, Pembrokeshire. Mr. Sowerby’s specimen was very imperfect, merely a portion of the cast of a distorted valve ; and the position was subsequently corrected by Mr. Salter in ‘Siluria.” In 1846 Prof. M‘Coy gave a short but correct description and reduced figure of a valve of the same species (see Pl. XX, fig. 8) under the designation of Spzrifer ovatus, remarking that it is the largest Silurian Spirzfer with which he is acquainted. Prior, however, to this date, I should have observed that the same species had (in 1842) been described and figured by Hisinger, under the designation of Cardium multisulcatum. In 1848 M. de Verneuil mentions it as a Spirifer, retainmg Hisinger’s specific name; and in the same year Messrs. Phillips and Salter refer to this shell under the designation of Orthis liratus. In 1852, while I was preparing the “General Introduction” to the present work, Mr. Salter called my attention to this shell, as well as to Pent. Jens, suggesting that they should be grouped as a section of Pentamerus, presenting well-marked internal characters: at once distinguishing them from true Pentameri, such as P. Knightu, P. galeatus, P. linguifer, &. A description of these internal characters will be found in p. 54, pl. vii, fig. 118, of the above-mentioned “Introduction,” as well as in p. 227 of my late friend Dr. S. P. Woodward’s excellent ‘Manual of the Mollusca,’ published in 1854. At p. 229 of the second edition of ‘ Siluria,’ (1859) Mr. Salter, to whom Sir Roderick Murchison had confided the revision and notes of the fossil data in his work, observes, while speaking of the Brachiopoda of the Llandovery rocks, that ‘‘The Pentameri are, however, the characteristic fossils, which impart to this ‘zone its peculiar and distinct facies. No less than five species, whether smooth or only slightly mbbed, occur, and of these P. oblongus is the best known and the most widely spread. This typical shell is easily distinguished from the other species, P /ens and P. liratus, by the great length of the mesial septum, which in these latter is quite a short appendage to the V-shaped chamber. The two longitudinal plates, also, which divide the upper valve, are peculiar to this species; whilst in P. dens they are very short, and in P. liratus ave reduced to a pair of processes which pass inwards, but do not show upon the surface of the cast.” In 1860 Dr. Lindstrém describes the same shell as Cyrtina? multisulcata ; but soon afterwards, recognising his mistake, he identified his Gothland shell with Penxtamerus liratus. Lastly, Mr. Billings, availing himself of the differential characters pointed out by Salter, proposed for such shells as P. diratus, P. lens, and some other Canadian and American species, the generic designation of Stricklandia, and which he subsequently altered to Stricklandinia. This I will retain as a section of the large genus RHYNCHONELLID. 161 Pentamerus, and in which, I trust, the species under description will find a permanent home. As already stated, Stricklandinia lirata varies greatly in its external shape, and this will be best understood by a glance at P]. XX, wherein are represented some of the best examples of this species I have been able to assemble from our British collections. The size and regularity of the ribs are especially variable in different specimens, as well as the length of the hinge-line. In Sweden the shell has been found in a perfect condition; but in our British rocks we rarely find any portion of the shell itself preserved. Very good casts, however, especially of the interior, are common, and in those belonging to the dorsal valve (as may be seen in Pl. XX, fig. 11) there exist two elongated pits (the casts of the crural processes), whose length can be easily ascertained by the introduction of a pin or needle. Position and Locality. Stricklandinia lirata appears to range from the Lower Llandovery to the lowest portion of the Wenlock series. It occurs in the May Hill Sandstone of Howler’s Heath, south end of the Malverns; also near (north-east of) Chirbury; at Nash Scar, Presteign; Huntley Hill; Llangadock, South Wales, &c. Sir R. I. Murchison found it in the Woolhope beds of Woolhope; and Mr. Salter found it in the lowest Wenlock beds of Marloes Bay and Marloes Mill (Survey Catalogues). In Ireland it occurs in Lower Llandovery grey slate at Cappacorcogue, Cong, Galway ; and in higher beds at Uggool, Ballaghaderreen, Mayo. Abroad, Dr. Lindstrém found finely preserved examples in the “ Wisby group” of Gothland. In North America the Geological Survey of Canada obtained S¢. “rata at East Point, South-West Point, Heath Point, and the Jumpers, in the Island of Anticosti. STRICKLANDINIA LENS, J. de C. Sow. (sp.). Pl. XIX, figs. 13—23. ATRYPA LENS, J. de C, Sowerby. Sil. Syst., pl. xxi, fig. 3, 1839. SPIRIFER ? L&VIS, Id. Ib., pl. xxi, fig. 21. (Not Pentamerus levis, J. Sow., Min. Con., pl. xxviii, fig. 2; nor Pent. levis, J. de C. Sow., Sil. Syst., xix, fig. 9; P. /evis being the young of Pent. oblongus.) PENTAMERUS LENS, M‘Coy. Brit. Pal. Foss., p. 209, 1852. —_ MicrocameErvus, M‘Coy. Annals and Mag. of Nat. Hist., 2nd ser., vol. viii, p. 290; and Brit. Pal. Foss., p. 210, 1859. _ LENS, Morris. Cat. of Brit. Foss., p. 142, 1854. _— — Salter. Siluria, 2nd ed., p. 100,Foss. 14, fig. 1, and pl. viii, figs. 9, 10, 1859. Srricktanpia — Id. Billings, Canadian Journal, p. 51, fig. 88, 1861. SrricKLaNDINIA — Billings. Cat. Sil. Anticosti, Geol. Survey of Canada, p. 45, 1866. Pentamerus. — Salter. Mem. Geol. Survey, vol. iii, pp. 276 and 360, 1866. _ Spee. Char. Longitudinally oval, sides and front rounded, greatest width nearer the beak. Valves moderately and almost equally convex or deep. Hinge-line nearly straight, and less than the width of the shell. In the dorsal valve there is a rounded mesial fold, of moderate elevation, which in front forms a convex lobe. In this valve 21 162 BRITISH SILURIAN BRACHIOPODA. the beak is incurved; the area narrow, triangular, and divided in the middle by an open fissure. Surface smooth, marked only with concentric lines of growth and obscurely radiating fine longitudinal striz. Inside the ventral valve the two converging dental plates are exceedingly small, supported by an equally small vertical septum. In the dorsal valve there are in the middle of the narrow hinge-area two small converging, but not united plates; and close to the hinge are two small elongated scars, due to the adductor or occlusor muscles. ‘Two specimens measured— Length 2 inches 7 lines, width 2 inches 1 line, depth 10 lines. 3» OF dntagpisdD mag jis domgjoo Fis, goroigt lig Ods. In outline this species much resembles Pentamerus oblongus ; but it is much flatter and its beak not so much incurved; and its area and straight hinge-line also distinguish it. Again, the external resemblance is in strong contrast with the interior ; for St. lens possesses the small plates of Stricklandinia, and not the large ones of Pentamerus ; 1 am therefore surprised that Prof. M‘Coy should say, at p. 210 of his ‘British Pal. Fossils,’ that S%. Jens has exactly the same internal structure as P. odlongus ; and this remark inclines me to surmise that, while describing his so-termed P. Jens, he had before him a specimen or cast of P. oblongus. ~ Exteriorly, St. Jens is at once distinguished from S¢. divata, both by its external and internal characters; thus, there are no cavities in the cast wherein a needle’s point can be introduced, as in S¢. Lirata ; and, although at first sight there may not appear to be much difference in the respective internal casts, this character will at once serve to distinguish them. Prof. M‘Coy’s Pentamerus microcamerus is nothing more than a'synonym of Stricklandinia lens, and, as that author observes, is quite different from P. /evis, Sow., to which he supposed Mr. J. de C. Sowerby had erroneously referred the fragment drawn in pl. xxi, fig. 12, of the ‘Silurian System.’ In a foot-note to p. 229 of the second edition of Murchison’s ‘Siluria,’ Mr. Salter observes that “the P. microcamerus (of M‘Coy) appears not to be distinct from P. /ens;’ and on a recent examination of the Silurian fossils in the Woodwardian Museum at Cambridge, Mr. Salter and myself found an undoubted specimen of Strick- landinia lens from the Lower Llandovery of Mandinam, labelled by M‘Coy Pentamerus microcamerus, and in another drawer, a specimen of St. vata from May Hill, also labelled by M‘Coy P. microcamerus. This name, therefore, may be eliminated from our lists." Position aud Locality. Stricklandinia lens occurs in the Lower and Upper Llandovery rocks, and is equally abundant in both. In the Lower Llandovery Mr. Salter has | identified it from Mandinam, Goleugoed, and Gorllwyn-fawr, in the Llandovery district ; Priory Mill, Haverfordwest ; Cefn, near Buttington; Mathyrafal, near Meifod; Rhyader ; and Pumpsant, Carmarthenshire. In the Upper Llandovery at Norbury, Bishops * I may here mention that, at Prof. Sedgwick’s request, Mr. Salter has recently carefully re-examined those Silurian fossils described by Prof. M‘Coy which are in the Woodwardian Museum, Cambridge; and all the original labels have been preserved in those cases where the localities or names of the species have undergone revision. The nomenclature of the beds is, of course, that of Prof. Sedgwick. RHYNCHONELLID A. 163 Castle; Bromsgrove, Lickey; Worcester Beacon, Malvern; May Hill; Huntley Hill; Chirbury ; Gunwick Mill, Gullet Wood, Howler’s Heath, &c., west of the Malverns ; Avery Green, and Woodford Green, near Tortworth ; at Mandinam, Pen-lan, and Castel- craig-gwyddon, Llandovery ; ‘Trecoed, Builth, &c. Mr. Salter mentions that at May Hill and in the Malverns S¢. Zens is more abundant than Pent. oblongus ; St. Hirata being found also in the same beds. In the Shropshire and western districts it is less so. In the Geological Survey Reports of Canada Mr. Billings quotes S¢. Jens from South- west Point, and the Jumpers, both in the Island of Anticosti. Genus—RHYNCHONELLA, Fischer, 1809. : Ref.—* Introduction,” p. 93. This excellent genus has been so often described in the present work, that it will not be necessary to again refer to the subject, further than to mention that since the pub- lication of my “ General Introduction” the anatomy of one of its most characteristic living types has been admirably described and illustrated by Mr. Albany Hancock,—in the ‘ Philosophical Transactions’ for the year 1858. Much still remains to be done before the multitude of species at present referred to the genus by different authors can be properly weeded, and classed according to the modifications presented by their interiors. Indeed, Prof. Hall has already detached from it certain forms upon which his genus Hafonia is founded; and it is very probable that, when the interiors of more of the species shall have been discovered and properly studied, it may be necessary to divide the numerous species into several minor sections, or even genera. In all the published lists of Silurian Rhynchonelle a number of species which do not belong to the genus have been provisionally admitted by several paleontologists, and necessarily so until the interiors are known; and although I believe I have successfully detached some of these species, and placed them in their proper genera, there still remain a few of whose correct position I feel very uncertain, and they must, I suppose, be temporarily allowed to encumber the genus." In the second volume of the ‘Memoirs of the Geological Survey’ Prof. Phillips proposed the generic designation of MHypothyris for the plaited Terebratule; and in his ‘British Paleozoic Fossils’ Prof. M‘Coy adopts that of Hemithyris for our British Silurian species of Rhynchonella ; these designations, however, have been found to be synonyms of the genus distinguished by Fischer de Waldheim in 1809. 1 It is a useful canon in paleontology, that when, from imperfect materials, the exact genus of a new form cannot be ascertained, the describer shall place it in some leading and well-known group, such as Rhynchonella, Spirifera, Terebratula, &c., instead of under a new but doubtful name. By this rule frequent changes are avoided, the leading genus being understood to be a temporary storehouse for indistinct but allied forms.—J. W. S. 164 BRITISH SILURIAN BRACHIOPODA. RnYNCHONELLA CUNEATA, Dalman and Hisinger (sp.). Pl. XXI, figs. 7—11. TEREBRATULA CUNEATA, Dalman. K. Vet. Akad. Handl., p. 141, pl. vi, fig. 3, 1827. — _— Hisinger. Bidrag till Sveriges Geognosi, part iv, p. 239, pl. vi, fig. 3, 1828. — — Id. Lethzea Suecica, p. 81, pl. xxiii, fig. 5 a, 6, 1837. —_ —_ Angelin. Mus. Pal. Suec., 1838. ' ie — J. de C. Sow. Sil. Syst., p. 625, pl. xii, fig. 13, 1839. ATRYPA _— M‘Coy. Synopsis of Sil. Foss. of Ireland, p. 39, 1846. TEREBRATULA — De Verneuil. Note sur le parallelisme des Dépéts Paléo- zoiques, Bul. Soc. Géol. Fr., 2nd ser., vol. iv, p, 698, 1847. — — Barrande. Silurische Brach. aus Bbhmen; Natur. Abhandl., vol. i, p. 80, pl. xvii, fig. 11, 1847. _ _— Davidson and De Verneuil. Bull. Soc. Géol. Fr., 2nd ser., vol. v, pp. 331 and 346, 1848. — — Bronn. Index Pal., p. 1233, 1848. SPIRIFERINA — D’Orb. Prodrome, vol. i, p. 42, 1849. HypotHyris —_ Phillips and Salter. “Mem. Geol. Survey, vol. ii, part l, p. 280, 1848. TEREBRATULA — Salter. Quart. Journal Geol. Soc., vol. vii, p. 172, 1851. ATRYPA — J. Hall. Palzont. New York, vol. ii, p. 276, pl. lvii, fig. 4 a—r, 1852; and Rhynchonella cuneata, 12th Annual Report of the Regents, &c., p. 77, 1859. — _ Morris. Catalogue of British Fossils, p. 132, 1854. RETZIA — Salter. Siluria, 2nd ed., pl. xxii, fig. 8, 1859. RHYNCHONELLA — D’ Eichwald. Uethza Rossica, vol. i, p. 765, 1859. _ — Lindstrim. Ofv. K. Vet. Akad. Férhandl., p. 365, 1860. Spec. Char. ‘Triangular or cuneiform, longer than wide, broadest anteriorly, or near the front, posteriorly tapering into an almost angular beak. Valves usually depressed or moderately convex ; beak of ventral valve more or less elongated or produced ; foramen circular, placed under the extremity of the slightly incurved beak, margined, and separated to a greater or lesser extent from the hinge-line by a deltidium in two pieces ; lateral portions of the beak much depressed, forming broad, flattened, and slightly concave spaces, which extend to fully half the length of the shell or more; sinus wide and shallow, commencing at a short distance from the beak, and extending to the front. Dorsal valve somewhat deeper or more convex than the opposite one, flattened at the umbone, but soon after forming a slightly raised broad mesial fold, which extends to the front. Surface of each valve ornamented with from ten to fourteen angular ribs, of which four or five compose the fold, while three or four occupy the sinus, the surface being also regularly crossed by numerous fine, nearly equidistant, slightly raised, concentric lines or ridges. ‘'T'wo specimens measured— Length 11, width 9, depth 6 lines. yp ae Ai ot RHYNCHONELLID A. 165 Obs. Although some uncertainty seems to have prevailed amongst paleontologists as to the genus to which Dalman’s species should be referred, all the evidence in my possession would tend to confirm its position in the genus Fhynchonella. The form of the shell is very like that of several well-known species of the genus, such as Rh. angulata, Linn., &c. When quite young (fig. 11) there is no apparent mesial fold, the dorsal valve being depressed along the middle, with interspaces of equal width between the ribs. The foramen also is then contiguous to the umbone of the opposite valve, while the narrow deltidial plates which margin its lateral portions are disunited in the middle; but as the shell acquires age the mesial fold becomes developed, and the beak more or less elongated, so that the foramen is in many specimens at a considerable distance from the hinge-line, as seen in figs. 7,9, 10. At page 276 of vol. ii of the ‘ Pal. of New York,’ Prof. Hall remarks that this species presents considerable variety of form and proportions. It appears difficult to make out whether it was Dalman or Hisinger who first gave the name of cuneata to this species. Dr. Lindstrém thinks it was the latter, as in the ‘ Bidrag til Sveriges Geognosi,’ part iv, p. 239, he mentions Zerebratula cuneata, D., and gives a drawing of it in his pl. vi, fig. 3. The D. evidently means Dalman; but if the memoir of Dalman had been then published Hisinger would have cited the plate and figure of the last-named author. It is probable that Hisinger had seen Dalman’s manuscript, which was ready in 1827, but not published until 1828. However, it is also strange to find in Dalman’s memoir, ‘ K. Vet. Akad. Handl.,’ p. 141, the species referred to as Hisinger’s, while in the ‘ Lethaa Suecica’ Hisinger again restores it to Dalman. The only way I can see to settle the authorship will be to assign it to both. I do not know what to make of M‘Coy’s Atrypa sexcostata (‘Synopsis Sil. Foss. of Ireland,’ p. 41, pl. iii, fig. 30, and fig. 13 of our Plate), which is stated to be ‘“ Trian- gular, depressed; front subtruncate, sides straight, margin very obtuse; surface with six angular radiating ribs. Zoc.—Lettershanbally, Leenane, County Galway, and in the sandstone of Shanballymore, Oughterard, County Galway, Ireland.” I have seen the original specimen, kindly lent to me by Sir R. Griffith; it is an obscure fragmentary fossil, and may, perhaps, be an imperfect specimen of RA. cuneata. Position and Locality. Rh. cuneata occurs in the Llandovery rocks, but principally in the Wenlock limestone. In the Woolhope limestone of Hay Head, near Walsall ; Wenlock limestone and shale of Dudley, Benthall Edge, Lincoln Hill, &c.; Canwood and Dormington Wood, Woolhope; Hill End and Callow Farm, Abberley ; Rock Farm, May Hill. In Scotland it is found in the shape of imperfect casts in the Llandovery rocks of Ardmillan, Thrave, and Mullock Hill, in Ayrshire; but I am not certain that the identifi- cation is correct. In Ireland M‘Coy mentions Shanballymore, Oughterard (Sir R. Griffith’s Collection). It is common in the Island of Gothland. It was also found by Barrande in the Silurian rocks of Bohemia. D’Eichwald quotes it from the banks of the River 166 BRITISH SILURIAN BRACHIOPODA. Smotrytsch, near the village of Laskovsky, in Podolia; also from the Island of Oesel. In America it is stated by J. Hall to occur in the shale at Lockport in the Niagara Group, also on the Niagara River above Lewiston. RHYNCHONELLA Srrickianpil, J. de C. Sow. (sp.). Pl. XXI, figs. 1—6, and 28. TEREBRATULA STRICKLANDII, J. de C. Sow. Sil. Syst., pl. xiii, fig. 19, 1839. — CRISPATA, Id. Ib., pl. xii, fig. 11, 1839. — SrrickLanDu, Dav. Bull. Soc. Geol. France, 2nd ser., vol. v, p. 329, 1848. HyporuyRris _— Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 282, 1848. Hemiruyris _— D’ Orbigny. Prodrome, vol. i, p.37, 1849. — _ M‘Coy. Brit. Pal. Foss., p. 206, 1852. RHYNCHONELLA — Morris. Catalogue of British Fossils, p. 146, 1854. — — Salter. Siluria, 2nd ed., pp. 250 and 544, pl. xxii, fig. 11, 1859. = — Lindstrém. Ofv. K. Vet. Akad. Forhandl., p. 366, 1860. Spec. Char. Transversely ovato-subtrigonal, very convex, somewhat wider than long, sides and front rounded. Dorsal valve gibbous or ventricose, slightly flattened at the umbone, pinched in or concave laterally; mesial fold wide, not commencing until at some distance from the umbone, and becoming more prominent as it approaches the front. Ventral valve not quite as deep or convex as the dorsal; sinus wide and rather deep ; beak very small, depressed, and incurved over, and appressed to the umbone of the dorsal valve; lateral spaces wide, concave, and indenting by a convex curve the corresponding margin of the opposite valve. Surface of each valve ornamented with from twenty-eight to thirty-four narrow, simple, angular mbs, which radiate from the beaks to the margins, and of which six or eight occupy the fold and sinus. ‘Two specimens measured— Length 15, width 16, depth 13 lines. ath. ole esavalsit Pad? BA Obs. This well-marked species varies a good deal according to age and circumstances. When quite young it is much depressed, the fold and sinus being hardly apparent, but with age the shell becomes globose, the ventral valve often ventricose, especially posteriorly, while the fold acquires its greatest elevation near the front. ‘The smallness of the flattened” appressed beak, and the concave or pinched-in lateral portions of the beak and umbone, give to this species a well-marked and easily recognizable character. Some internal casts show beautifully the muscular and vascular impressions (fig. 6). At p. 1231 of his ‘Index Palontologicus,’ Bronn places Rd. Stricklandii among the synonyms of ZA. borealis; but this is quite a mistake, as a glance at their respective figures will at once show; and it is probable that the distinguished German palzonto- RHYNCHONELLIDA. 167 logist was not acquainted with our British species, nor does it appear to be a common fossil, except in a few localities in England and abroad. The original specimen of Sowerby’s ‘‘ Zerebratula crispata”’ is in the Museum of the Geological Society. It is a moderately convex example of Z. Stricklandii, and was so identified by Mr. Salter some years ago while rearranging Sir R. Murchison’s Silurian collection, presented to that Society. Position and Locality. . Stricklandii appears to be rare in the Woolhope beds ; common in the Wenlock limestone and shale; and rare again in the Aymestry limestone. It occurs at Nash Scar, Presteign, im Woolhope beds. In Wenlock shale at Gaer-coed, Tucking Mill, Craig-y-coed, and Bryn Craig, in the Usk district; in Wenlock limestone at Hobbs, Longhope, and the Rock, May Hill district; Croft, and east of Ledbury, Malvern district; Rushall Canal, near Walsall; Dudley; Sedgley; Canwood, and Dormington, near Woolhope. At Llanbadoc, in Aymestry limestone, Usk district (Phillips and Salter). I am not acquainted with any Scottish or Irish example. Abroad it was met with by Dr. Lindstrém in the Island of Gothland, but there it appears to be exceedingly rare. RuyncHoneLta Witsont, J. Sowerby (sp.). Pl. XXIII, figs. 1—9. ? ANom1a subglobosa posticé dupliciter striata, Zinné. Mus. Tessinianum, p. 88, pl. v, fig. 6, 1753. ? — sacunosa, Linné. Syst. Nat., xii ed., vol. i, part 2, p. 1153, 1767. TEREBRATULA WILSONI, J. Sowerby. Min. Con., vol. ii, p. 38, pl. exviii, fig. 3, &c., 1816. ANomITES LAcUNOSUS, Wahlenberg. Nova Acta R. Soc. Upsaliensis, p. 67, 1821. TEREBRATULA LACUNOSA, Dal. Vet. Akad. Handl., p. 139, pl. iv, fig. 1, 1828. — * Whitson, Yon Buch. Ueber Terebrateln, p. 47, 1834. —_ LAcUNOSA, Hisinger. Lethza Suecica, p. 80, pl. xxiii, fig. 3, 1837. -- Wiusont, J. de C. Sow. Sil. Syst., p. 615, pl. vi, fig. 7, 1839. — crEeBRIcosTa, Id. Ib., pl. xiii, fig. 18, 1839. — Witsont, Angelin. Mus. Pal. Suec., 1838. — PENTAGONA, J. de C. Sow. Sil. Syst., pl. v, fig. 21, 1839. — Witsoni, De Vern. Geol. of Russia and Ural, p. 87, pl. x, fig. 8, 1845. ATRYPA — M‘Coy. Synopsis Sil. Foss. of Ireland, p. 42, 1846. TEREBRATULA — De Verneuil. Bull. Soc. Geol. Fr., 2nd ser., vol. iv, p. 699, 1847. — — Barrande. Sil. Brach. Bohmen; Naturw. Abhand., p. 82, pl. xviii, fig. 4, 1847. — — Bronn (parte). Index Palzeont., p: 1255. 1848. -- — Dav. and De Vern. Bull. Soc. Géol. Fr., 2nd ser., vol. vy, pp. 328 and 346, 1848. Hyporuyris _ Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 282, 1848. HeEMITHYRIS — D’ Orbigny. Prodrome, vol. i, p. 37, 1849. 168 BRITISH SILURIAN BRACHIOPODA. RHYNCHONELLA WiLsonI, Dav. Annals and Mag. of Nat. Hist., 2nd ser., vol. ix, pl. xii, 1852. -HreMitHyris — MCoy. Brit. Pal. Foss., p. 207, 1852. RHYNCHONELLA — Morris. Catal. of British Fossils, p. 148, 1854. ANOMIA LacuNOoSsA, Hanley. Ipsa Linnei Conchylia, p. 128, 1855. RHYNCHONELLA W1LsoNI, Schmidt. Archiv Nat. Liv.- Ehst.- und Kurlands, vol. ii, p. 210, 1858. — : D’Eichwald. Lethea Rossica, vol. i, p. 762, 1859. — — Salter. Siluria, 2nd ed., p. 545, pl. xxii, fig. 13, 1859. —_— PENTAGONA, Id. Ib., p. 545, pl. xxii, fig. 3, 1859. — cREBRICOsTA, Id. Ib., p. 544, pl. xxii, fig. 3, 1859. — Witsonl, Lindstrém. Gottland Brach., p. 366, 1860. — — Salter. Explan. Sheets 160, &c., Geol. Survey Ireland, p. 13, 1863. Spec. Char. Subpentagonal, but generally cubical, and often sub-spherical, about as wide as long; sides and front rounded; valves almost equally gibbous, and often so much so that the shell is twice as deep as either long or wide, and presents, when viewed in front or in profile, an elongated oval shape. Dorsal valve somewhat flattened, or gently convex at the umbone, with a slight longitudinal depression or groove along its middle; in front abruptly deflected, and almost perpendicular before meeting the margin of the opposite valve; fold wide, nearly flat, and in the ordinary varieties not raised above the general convexity of the valve. Ventral valve flattened or slightly convex posteriorly, but in front abruptly deflected, and becoming almost perpendicular as it meets the acutely dentated margin of the dorsal valve ; sinus wide, oblong, square, and nearly flat, very shallow, and scarcely defined on the surface; beak small, much incurved, and usually so much appressed to the umbone of the dorsal valve that no foramen is visible ; beak- ridges strongly marked, leaving a concave space between them and the hinge-line. Surface of both valves ornamented with from thirty to forty small, usually simple ribs, of which from six to nine occupy the fold and sinus; the ribs are likewise usually divided or indented along the middle in their proximity to the serrated margin. On the inner surface of the dorsal valve, under the divided hinge-plate, is a mesial ridge of small elevation, which extends less than half the length of the valve, and divides the slightly marked muscular impressions. In the ventral valve a depressed median scar, longi- tudinal and oval, is surrounded by a large saucer-shaped muscular impression. ‘T'wo large specimens measured— Length 13, width 13, depth 11: lines. 9 ‘Apes 7,10 ,, but the shell is usually smaller. Ots. As this important Upper Silurian species has by some authors been referred to Linné’s Anomia lacunosa, it will be desirable to search its history. In the twelfth edition of the ‘Systema Nature,’ p. 1153, 1767, Linné describes his Azomia lacunosa as follows :— A. testa subrotunda multisulcata ; valvulis apice plicatis ; altera Fic. 1—3 a. 4—4de. 5—5 a 6—6 b. PLATE XIII. SILURIAN SPECIES. Meristella ? crassa, Sow. sp. 1. Exterior of dorsal valve. Lower Llandovery ; Cefn-Rhyddan. 2. Internal casts of ventral valve. 2a. Mould in gutta-percha from the same. Same Locality as fig. 1. (Murchison’s original specimen.) Mus. Geol. Society. 3. Internal cast of dorsal valve. 3a. An enlarged fig. from a mould in gutta-percha of the same cast. Mus. Geol. Soc. . subundata (Hemithyris, M‘Coy). After the original figures in ‘ Brit. Pal. Foss.,’ pl. i 4, figs. 9, &e. Fig. 4, enlarged; 44, 6, c, nat. size. (This shell is not very unlike in shape to some flattened specimens of IZ. tumida.) Wood- wardian Museum, Cambridge. Athyris obovata, Sow. 5. Nat. size. 5a. A considerably enlarged interior of the ventral valve, to show the muscular and vascular impressions. Lower Ludlow. Collection of Dr. Holl. ,», ’ depressa, Sow. 6. Nat. size. 6a, 6. Enlarged figures from a young but perfect example. Woolhope limestone. Road between Alfric and Crew Hill, Malvern. 7—9. Meristella ? furcata (Terebratula, Sow.). 7. Internal cast of ventral valve, nat. size. 7a. The 10—13 e. 14—22. 23—30 a. 31—31 6. same enlarged. 70. A gutta-percha mould from cast, also enlarged. South of Bogmine, near Corndon Hill. This is the original specimen figured in ‘Sil. System’ (pl. xxi, fig. 16). 8, 9. Other casts (after the original figures). : Retzia? Barrandi, Dav. A series of specimens, showing modifications in shape; from the Wenlock limestone of Dudley, Hay Head near Walsall, and Buildwas near Wenlock. 12a, and 13a, 6, ¢, d, are enlarged illustrations. Atrypa’ Grayii, Dav. A series of modifications of this singular shell, from the Wenlock lime- stone of Dudley, and Hay Head, near Walsall. Fig. 14 is the largest example hitherto found. Figs. 14a, 15a, 16a, b,c, 176, 18a, 6, 19, 20, 21, and 22, are enlarged figures. a hemispherica (Atrypa, Sow.). A variety of specimens. 23. Copy of the original illustration in ‘Sil. Syst.,’ pl. xx, fig. 7. Upper Llandovery, May Hill. 24, Nat. size, and 24 a, 6 c, enlarged, from the Upper Landovery, Charfield Green. Mus. Geol. Survey. 25. From the Upper Llandovery, Ardmillan, Ayrshire. 26. Mullock Hill, Ayrshire. 27. Penkill, Ayrshire. 28. From Ankerdine, in May Hill sandstone. 29. Internal cast of ventral valve, nat. size, and 29a, enlarged, from Penwhapple Glen, Ayrshire. 30 and 30a. Internal cast of dorsal valve. Mus. Geol. Survey. - Scotica, M‘Coy. After the figures in Brit. Pal. Foss., pl. in, fig. 10. Mullock ; Dalquoran; Woodwardian Museum, Cambridge. SILURIAN &N Hanhart, imp M Thot Davidson. del, & lith PLATE XIV. SILURIAN SPECIES. Fie. 1. Aérypa reticularis, Linn. Wenlock limestone, Rushall Canal. Specimen with one of its fringes almost entire. . ; 2. 3 - Impression of a specimen with marginal fringe almost complete. Wenlock limestone, Marloes Bay. Mus. Geol. Survey, London. 3) a bs Small specimen with fringe. Wenlock shale, Pentland Hills. ASAG. ¥s > From the Wenlock limestone, Dudley. 4a, enlarged. 5. . > A specimen with fringe viewed in profile. Rushall Canal, Walsall. 6 to 11. * A series of specimens of different ages and forms, from Wenlock limestone, Dudley. 12. a s A variety, with small numerous ribs. Dudley. 13: Ps 55 Ventral valve greatly enlarged, froma specimen in which the ribs are unusually angular, and often bifureating. Wenlock shale; Mus. Geol. Survey, London. 14. i a (var. orbicularis, Sow.). Penkill Hill, Girvan, Ayrshire. 15. 4 of Interior of dorsal valve (minus the spiral lamellz), to show the hinge-plate and muscular impressions. Wenlock limestone, Dudley. [A full account of the internal appendages, by Mr. R. P. Whitefield, is given in the 19th Report on the New York State Cabinet, Dec., 1866.1] 16. . me Interior of ventral valve. Dudley. ile ;, A A fine internal cast of dorsal valve. Wenlock limestone, Usk. Museum of the Geological Society, London. : 18, 19. ‘ 18. Interior of ventral valve, from the Upper Llandovery, Huntley Hill. Mus. Geol. Survey, London. 19. Internal cast; same locality. 20. “s ; Silicified cast, the spaces occupied by the spiral coils being left empty. Wenlock limestone, Malvern; Mus. Geol. Survey. D2 ss. ie Young shells with few ribs, approaching in character to 4. aspera. Wenlock limestone, Dudley. ‘ «The internal appendages of the genus dérypa have been known to consist of a pair of spiral cones, placed side by side, with their apices directed towards the cavity of the dorsal valve. ............ By carefully cutting and preparing favorable specimens, I have found that in place of the short crural processes so often figured, there is an entire and continuous loop connecting the spiral cones, ............ having its connection with the spiral ribbons at a point relatively much nearer to their origin on the hinge-plate : still more distant, however, than the points figured by Mr. Davidson and others. This loop, so far as yet observed, is confined to the rostral or posterior part of the shell, and never passes over or in front of the spires, as in Prof. Hall’s genus Zygospira. From its origin on the posterior portion of the first volutions of the spires, the loop curves gently forward and upward ; the central or elevated portion lying between and behind the cones, and forming a more or less abrupt curve, or prolonged into a point directed towards the dorsal valve,’ &c. Poe > f ‘ c a) A a ‘ - ¥ i afi pa i? a iso yey me nba Brent dco. Vy oe * a7 wes yl Airaid on Bite ii son! ~ iene vant a & a) | z Kolo. 6 ie hal ne vd faiih Baty. 2 : gat roa oh ie - ry ] i} A) apt baile, pt Pia) UTI LOU lied "i eet, be pit Un A. evil i w tice! hy tay yh oni A; ¥ J ic ‘4 7 Vie Geta te - oy Dae a hay é . * ‘ ‘ I iri ' ; f TY: awed fh 2 Ls : : , onli A ‘ - « ) y » -_ ; , ‘ = oan |. eee ret ree ; ‘ ’ shel Teh A a +e v ae eal se ; ‘ ¥yitae wiviey dad Lr ucbvadert : ; a jt - = 2 i , ” : ‘| | : . , ' ' y | = . : ’ o ‘ | | « a8, j PLATE XVII. SILURIAN SPECIES. Fig. 1,la,16. Pentamerus Knightii, Sow. Aymestry limestone, Aymestry. 2. : $F A very elongated example. Aymestry limestone, Mocktree, near Ludlow. 3. : s In this specimen a portion of the dorsal valve has been removed, to show the V-shaped chamber of the ventral valve. Aymestry limestone, N.E. of Leintwardime. Mus. Geol. Survey. A. sy ‘ A very transverse specimen, from the Aymestry hmestone, Aymestry. 5, 5a, 6. . i T'wo small specimens. Aymestry limestone, Mock- Tree: Ted * 5s A young shell, found by Dr. Holl in the Wenlock limestone of Benthal Edge. 8. 5 es A specimen seen from the beaks. (‘Sil. Syst.,’ pl. vi, fig. 8.) 9. ne bos Profile view of the interior of both valves. S, septum of ventral valve; V, dental plates; z, V-shaped chamber; m and x, septa in dorsal valve; O, hinge-plate. 10. a . Transverse section. The same letters refer to the same parts. ll—14 a. 3 linguifer, Sow. Different ages and modifications in shape. Wenlock limestone, Dudley, and Rushall Canal, Walsall. 14 3b. > ~ Interior of both valves seen in profile. II Pl OILURIAN . RITE heed RRL ES ts OPE A PERERA 88h) crt NS Ot ORETRS PS STS eR RR Els 5 joo ~ ——! M.kNHanhart pnp . — The* Davidson del, & ith aga Latthyy: ai iyIoVvObia 1 / a, vi, oiah}? mye ia he P z , sLitMatita | 1) i od) Ma Rodh fil nv dei a onl ehid Vyint an Boa? sien vf TY Ry bhal.l ee ene crn PPaY Amiliior te ; oie; 1 1) Ligawla anwe) wo? Beat | woitaghlo! x ssiQive a rh YOO" lard ll oh dio Ae @ itob Biigioy uh PD ners ads iT we ¥ 2 in “" { Mot yovobsjal. ea stoiisetio®) a‘nw: i) 0 » Ap -¥ ee ye ban nod pili sherk wish ; d ‘5 : : Set) =; viovebiaild y mer, ay ; ae WotR atiplyys PLATE XVIII. SILURIAN SPECIES. 1—3. Pentamerus oblongus, Sow. After Sowerby’s original figures (‘ Sil. Syst.,’ pl. xix, fig. 10). Upper Llandovery; Shropshire and Llan- dovery. | 4, Aa. i = Upper Llandovery ; Hope Quarry, N.E. of Chirbury. Mus. Geol. Survey of London. : et Internal cast of ventral valve, showing the median septum. Upper Llandovery, Norbury. Mus. Geol. Surv. Or 6—6 4. < is Internal cast. Upper Llandovery ; Nash Scar, Presteign. Mus. Geol. Surv. ie Ps ‘ Internal cast of ventral valve. Upper Llandovery; the Hollies, Wrekin. Mus. Geol. Surv. 8. x . Ventral valve. Boocaun, Cong, County Galway, Ire- land. Sir R. Griffith’s. Collection. This is the specimen referred to by Prof. M‘Coy in his ‘ Synopsis Sil. Foss., Ireland,’ p. 38. 9. * > Internal cast, seen from the beaks, and showing the position of the septa and converging dental plates in both valves. Upper Llandovery ; Craig-yr-Wyddon. Mus. Geol. Surv., London. 10. . ‘ Small specimen. Llandovery rock ; Ardmillan, Ayrshire. Mr. D. J. Brown’s Collection. 11. $5 > Longitudinal section, showing the septa and dental plates. Cappacorcogue, Cong, County Galway. Sir R. Griffith’s Collection. i ‘5 (P. levis, Sow.). A fragment (‘ Sil. Syst.,’ pl. xix, fig. 9). Upper Llandovery ; Shropshire. SILURIAN 6 q a fe 2 & A | vay ey ‘ ‘ail Keuieide erring: au ‘oahaly Dt, a ue i ‘hs “A Par. @ Jend) woh UiCiV Bega kf pids ¢ i apts “WS loAallnd mew svlav Ly tee eo" 74 7 Ae 3 rus that eay To j oP om D elquadWas'l | doen Aampiehio YA mig) ©: as PD Venn gh) «vase Te dens dee ial) wie cx : me aa} ebine hk) eth ay wits 5} Sapna 24d ney) a ball ww rot Ais) : BY ERIM yy wok RC brn sis Se Jane. Bor wen hywsis «flats pi iaier! , lav Iover Yo vai © ath , WO paid @ geisp lif’ wety $n ize ey Sebago yaa Ja ipbe galy- * "6 _ a ei? Wyerte 6) %& oe dap tia " had st Fw ow, bh pyl-biew owlay | — saibeeged ni Sa(@eans .¢v cv tas iv Ps F ae We’ His Hip faiye 7 vat ; “Years ur NC) vada) i parse ‘ oe graluld mi 2/4 tet _aom neat ai tld sale etd, WR UR gist sD ¥ 4 rs Cs nal pai Be a. val die oil we 14 5 i . padi :% Traex' “ ‘e of ladijyo in Se Chai! - “ti vied M ferdaes dn sen Wuteke: CL ti a toed wil yw en ‘ ¢" -yldea') ° a 'qoteR, peaiad 4) wr Galena 4 Yratah ae tt que) pe ttee eutiateamacneT | 12 os rer DYOAA duane AME (gal ve «Qoton! eerny iy) 37 fice Ty ’ Ati dain ys Rei? yy te Ole wy py . dhaies? bahay we rw ps wet ie ade cath edt Lin ay sift Vivato pebietn PLATE XIX. rSILURIAN SPECIES. Fic. 1. Pentamerus oblongus, Sow. Cast of ventral valve. Llandovery rock ; Penwhapple Glen, Ayrshire. Mr. D. J. Brown’s Collection. 2. 5 < After original figure of P. levis, Sow. (young of P. oblongus). ‘ Min. Con.,’ pl. xxviii, fig. 2. a be Knighti, Sow. Portion of a dorsal valve from Ballyaglish, east of Ferriter’s Cove, Dingle, County Kerry. Sir R. Griffith’s Collection. 4—9. _,, undatus, Sow. 4. Internal cast of ventral valve from Cefn-y-Garreg. Mus. Geol. Soc. 5. Internal cast of ventral valve. Lower Llandovery; Llandovery. Mus- Geol. Survey. 6. A bivalve specimen, viewed from the front. Lower Llandovery ; Cefn Rhyddan. 7. Cast of ventral valve. Figs. 4 and 6, after the original examples figured in pl. xxi of the ‘Silurian System.’ Mus. Geol. Soc. 8. Cast, fractured so as to show the small converging dental plates of ventral valve. Noedd-Grug. Mus. Geol. Survey. 84, 88. In- ternal cast of a ventral valve, showing the vascular impressions. Lower Llandovery ; Mathyrafal, Montgomeryshire: Mus. Geol. Survey. 9. In- ternal cast of ventral valve from Guilsfield, N. W. of Welshpool. Mus. Geol. Survey. 10—12. ,, globosus, Sow. Fig. 10. After the original figure in ‘Sil. Syst.,’ pl. xxii, fig. 2a. Lower Llandovery ; Gorthoyn Fach, Llandovery. Mus. Geol. Soc. Fig. 11. Another specimen, nat. size. 11a. Enlarged; from Lower Llandovery ; Castell-Craig-Gwyddon. Mus. Geol. Soc. 12. Internal cast; from Golden ; Grove, near Llandeilo. ; 13—21. Stricklandinia lens, Sow., sp. Figs. 13, 14. After the original figures in ‘Sil. Syst.,’ pl. xxi, fig. 13; fromthe Upper Llandovery ; Norbury. Mus. Geol. Soc. 15. Slightly restored figure, from a specimen obtained from the Lower Llandovery ; | North of Gorllwynfawr. Mus. Geol. Survey. 16. Internal cast, viewed . from the beaks. Upper Llandovery ; Craig-yr-Wyddon. Mus. Geol. Survey. | 17. Portion of the internal cast of ventral valve. Llandovery ; Woodford Green, near Tortworth. Mus. Geol. Survey. 8. Ventral valve. Upper Llandovery; Norbury, Bishop’s Castle. Mus. Geol. Survey. 19, 20. In- ternal cast. Upper Llandovery; Avening Green, near Tortworth. Mus. Geol. Survey. 21. Transverse section, quite close to the hinge. » 23. 5, 5, (Pentamerus microcamerus, M‘Coy.). 22. A fragment, after the drawing in ‘ Silurian System,’ pl. xxi, fig. 12. Llandovery; Lickey, Staffordshire. 23. After the woodcut at p. 210 of M‘Coy’s ‘British Pal. Fossils,’ stated to be the internal cast of rostral part of ventral valve, showing the cardinal area and small rostral chamber formed by the converging of the dental lamellee. »& lith. 1 A ae’ Tho’ Davidson . a ae saad sh WaPitds y) m eye POH ape lb kee W) ] A 4 ; A ae , om f 4 wvigd¥ Pee $79 ais iy A Prine on sae Reh) WEY) vas ad I 4 ae PS icy (POA oS ane ee ie Te ie j ONS ae ee? eee we] 5 “ie vt Perl bis a. ea, Ai i _ a 2 J ’ adi \ nd an cyt i oti uy 9 Blichiagone » 4} Thsidts f . . 4 n q ? ig | > my - ea aT ee Nd ee ee ——— Fic. 1—2. PLATE XX. SILURIAN SPECIES. Stricklandinia lirata, Sow. sp. Upper Llandovery ; Howler’s Heath, Malvern bP) Hills. 1 a, internal cast of dorsal valve. 18 and 2, internal casts of ventral valve. Dr. Holl’s Collection. 3a. Internal cast of dorsal valve; 3, of ventral valve. Howler’s Heath. Mus. Geol. Soe. Internal casts. Upper Llandovery; May Hill. A dorsal valve of very transverse shape. Woolhope limestone ; Woolhope. Mus. Geol. Surv. | (Spirifer ovatus, M‘Coy.) Drawn from the specimen of which Prof. M‘Coy gives a reduced figure in his ‘ Synop. Sil. Foss. of Ireland,’ pl. i, fig. 24. From Edgool, Ballaghadorreen, County Mayo. Sir R. Griffith’s Col- lection. Interior of ventral valve; and Interior of dorsal valve. These figures have been drawn from gutta-percha moulds, made from internal casts found at Howler’s Heath. Portion of a beautifully preserved internal cast of dorsal valve from Howler’s Heath. Mus. Geol. Surv. Horizontal section, close to the hinge. An internal cast of a small, exceptionally shaped or mal- formed specimen. From Upper Llandovery; Nash Scar. Mus. Geol. Surv. M&N .Hanharl imp Tho* Davidson det & 1th ro o PLB oni i wae Laie ' ‘beat ul 00 ¢ ' * ‘a i be’ ED : oles rs i ae sail d Soetge WM garth ects! orn : ise oh - LAR uate , yf av Lei fiey "Y ‘ or eljy ait raving grath 1 ; oe \ Nad esis Hh al 1 , 4 _— ie OB, wht, ae iy villi ret } ~*~) Hane . Sats? a a 4 Debt Mee dl sledl iy O30 | , pins cs 4 - WyGioart 4 hry j ; ; ‘ lob Leg cranny 1 Woks a ‘ an oh iad) fc tos gftabee s 4 , ly s ead egQuyes: «it yn 4 ee ee ee ee ee 7 pure af bre vhund! aot wluve & 4 P Y x ae ‘ eta mi- , . 2 bls nhs! ied pv vw ’ a. i igi 4 eo CHAE A 405 Er¥ w?, ule A) oy ? j P ‘ , if if "Dette Apa “J ’ ig ‘ xpi fede gf 7 “4 aan if AG ae je cA dA bidtagues wi i ved sit bs Pe a? 5 ” . . meer! walt, ee. igelboG seeajeom i er til ad aootaaW nlp. wil aeons om J i Pa - we" y tive ay), ies APA) wie ois te a id si}? py Abe rh Th 0 OD , Z F Ravi Wrod! y iwi | syaMia Gl ja." Ao oi oO i Lua Ohi og) oo {Mob wimg. ghrtertye ~ - PLATE XXI. SILURIAN SPECIES. Fig. 1—6. Rhynchonella Stricklandi, Sow. 1, 1a. After the original figure, ‘Sil. Syst.,’ pl. xiii, fig. 19. Wenlock limestone; Longhope. Mus. Geol. Soc. 2-24. A large specimen from Wenlock shale; Gaer-y-coed, Usk. Mus. Geol. Survey. 3,4,5. Three specimens from Wenlock limestone, Malvern. 6. A very fine internal cast of ventral valve, enlarged; showing the muscular and vascular impressions. (The ribs have not been marked, in order to show the vascular markings the better.) Wenlock limestone ; Tucking Mill, Usk. Mus. Geol. Survey. 7—lle,and 12? Rhynchonella cuneata, Dalman. 7, 8, 9. Different specimens from the Wenlock limestone of Dudley. 10a. Beak enlarged, to show foramen and deltidium. 11. A young example; a, 4, c, enlarged. 11 c. Beak very much magnified, to show the foramen and deltidium. 12. A cast which has been referred to Rh. cuneata, from Mulloch Hill, Ayrshire ; but this identification is uncertain. 13. Rhynchonella sexcostata, M‘Coy. After the original figure in the ‘Synops. Sil. Foss. Ireland,’ pl. ii, fig. 30. Lettershambally, Leenane, County Galway. Sir R. Griffith’s Museum. The value of this species is uncertain, no complete example having been found; and it is here given simply ~ for sake of reference. 14—20. a borealis, Schloth. Figs. 14, 15, and 18. Three large typical specimens from the Wenlock limestone ; Longhope. Mus. Geol. Survey. 16,17. Two varieties from Dudley. 19, 20. A variety with a large number of smaller ribs, termed Terebratula lacunosa in ‘Silurian System,’ pl. xii, fig. 10. Wenlock Edge. 21—23. i », var. diodonta, Dal. Fig. 21, copied from Sowerby’s figures of Terebratula bidentata, ‘Sil. Syst.,’ pl. xii, fig. 13@; and ‘Siluria,’ 2nd ed., pl. xxii, fig. 5, where it is designated Rhynchoneila borealis, var. diodonta. Wenlock limestone; Dudley. 22. Also from Dudley. 23. A small specimen from the Wenlock limestone of Falfield, showing the scaly concentric ridges described by d’Eichwald. 24—27. - » Variety. Fig. 24, from Wenlock Edge. Mus. Geol. Survey. 25—27. From Dudley ; showing how variable is the number of the ribs on the fold and in the sinus. x Stricklandi (Terebratula crispata, Sow.). After the original figure, ‘Sil. Syst.,’ pl. xii, fig. 11. Mus. Geol. Soc. SILURIAN Tho* Davidson del & lith M & N.Hanhart imp a 7 fe H * = ne f bing! ress eF uh) fsaentos ab LE w) Us ; asi iflonig head atin A i Lai } asad : ‘¢ Bee “ lane (. prea! 23) ‘ae mele ie ‘ Radhas ig oyotts ‘f oaaltya? , Sk Poor walavi)’ ; j eh eT wt hte ah Sb ey Ses; ¢etstoe nde lanvetad & Bh m4 ae ih FVinadt 2) (ray Garis A vi :t ine Abas bis Wil? 0 1 wl i. f Fa ae oe i han ny 1 a a 5 oa (mee IM DL aye 44 ! he, see baivtojal~. 1h . Semi il Hse ty teh? RTGS. sara b Bae: a » aie i enctesssil degtas® roca slatiey Waev auaty, MOP ERIN: Ag ie eink } ‘ a = * ’ ‘ 0 *- } ‘ha i " ‘ Le taal | - WERE PTs “Salivatio fret u Sperry . iS bi yat - oer ! fi i. 7 mie ry nS ‘ hei Sali tia fet tals ini Norte 238 on few : vee 7 es are &, tat ry tengtiat ttiroh aley3 AD Bt ri ttktt: Sn eis Deeny 1] Ps! Alpi: ° “= F “apie Atl) Barty bay! 5 P »7 ; A SORTS Se a Na ONS he eg eld itn isi pd Sarr type! We a ih co Trivia mite = weiss) tS “7 sa ¥ 4 ’ i ain anc hill sy Wf a5 a arent ‘> Pe a ie Mie, * “i ™ F 4 ae Pa i. i : rN) A < a i hae ’ ‘ i 1 “a? hy + ' i 7 ies : as ns ‘anaes J a iit mabe 3h Bat HiT a Wy’ ini Si cies iy i> Fic. 23. Betumnites tavis. (Whitby Museum.) EXPLANATION OF PLATE X. Belemnites trivialis —sketch from a specimen in the Whitby Museum. Lateral view. Belemnites levis—sketch from a specimen in the Whitby Museum. Lateral view. Ventral aspect, near the apex. Dorsal aspect, near the apex. Striz, near the apex, magnified. . Striz broken into short plaits. 24. BELEMNITES DORSALIS, n. s. (Collection of Prof. Phillips.) '” ae d. o / S. uv She /. v. Gis 8. Lateral aspect, the specimen slightly angular. Another specimen, seen laterally. A specimen seen dorsally, to show the short interrupted groove. Striated apex ; not a common occurrence. ‘Transverse section near the alveolus. Transverse section towards the apex. 5. ByLEMNITES sTRIOLATUS, n. s. (Whitby.) Specimen seen laterally, with fine strize towards the entire apex. Specimen seen ventrally, with similar strie. The striz, magnified. Transverse section. 26. Benemnites Lavis. (Whitby.) ot. Specimen seen laterally, showing striation near the apex. The same, seen ventrally. Longitudinal section, showing arched alveolar cavity. Section of phragmocone and spherule. Transverse section. BELEMNITES SUBTENUIS. Side view, showing one of the long faint dorso-lateral grooves. Ventral aspect, showing the faint ventral groove. Dorsal aspect, showing the two dorso-lateral grooves. Section across the alveolus. Section across the guard, in the middle. . Section across the guard, near the apex. Stria, near the apex. The specimens were collected by Prof. Phillips at Saltwick, near Whitby, in Upper Lias. 5 RC ee Si Gt Att Te a =— . = Be i ar ae sean sar = awa i as paneer Sas - SI nN NI ce Sr oceans S ae Fig. yee tt a OO ta fansite ane sical eB at SAT NESS Se hans i t, Parts. Lup Becque & Eeiekertaiar Tith. ~y 7 4 ¥ a 5 iP i I . ia ¢ » iP j 7 an ‘ a , , a) en 7, ° ) £5 Was HQh 1: . : . ; ~: u. fs : OT Bir Wilrretyy ws oye ny ij A ew, ; = ' oi | “9 i ' dba a mh ti Rey s iar? d 6 ee Stee eM Soome totes \ hob Ty) ill i ay Pid Bw Saves } Ab ¥ aw, 7 Pillans aategr! s10m Beg aR No'taage Linvint SO v a a ! ] 10h Hit A al le vette rayiit A : * $ " 2 shes ny “sete a! in pet Ane _ .- ? , a i) i gist DAN Fo fel Saige P - hengd . _ Ye fae) vero | : . 4 F ¢ . 7 ‘ > be ~ srue 7 , ’ r ; iy ' er rue Sige as Re cali F aha * 4 ib F di fi eit { : = a . fi ' > - P ‘ * 4 7 ° find Sa a ; “ : re 2 ; ee hd ) ; 1* ’ - rel ye oe WOM a4 al " ’ . x A EXPLANATION OF PLATE XI. Fic. 28. BELEMNITES TRIPARTITUS. (Whitby.) v. Ventral aspect. d. Dorsal aspect, showing frequent striz. /. Lateral aspect. At v, d, is the apex of the alveolus. s. Shows cross section at the alveolar apex. The section near the apex. s. he interrupted striation. Specimen in Prof. Phillips’s Collection. 29. BELEMNITES SUBADUNCATUS, in various stages of growth. (Whitby.) Ss. Ventral aspect of a young specimen. Lateral aspect of the same. d. Dorsal aspect of a very young individual. 2”. Lateral aspect of a more advanced and more hastate variety. i”. The same aspect of one still older. | d.” Dorsal aspect of the same specimen. /*. The same aspect of one fully grown. s’, s’, s, s*. Transverse sections: s’ being across the alveolar cavity; s”, at the alveolar apex; s”, towards the apex, unusually excentric; s*, near the apex. Sa! sorcery At Ce ai COMO a SNP Cana Imp Becguet a Paris. P Lackerbauer Kith. wipers. A ¢ Aoagen Ma ; : pan ; ype ' Oh gee - : Pr yuil 2 i g PP pet 13 ‘ Tg SER (uid sae | di } ‘ . Rta) ew) 1090 1 . eer e,. 3 ay meiotic: tit rsh, sonnet a ala oi | A 2 ean adbioig Ait stingyo tei) o> 5 ‘ i . & ; . 2 Hades ihe aprii gist irpey Yo e Ss aa Wyo ‘ ira 0 oe " 7 , To 4! he eo | SS ee vad Gp, oi9 ae : A i ¥ gi aa 4 tel ‘ ah : Pe 7 ¥, pian id Adin offets ye LW ap 1 | uM 4 i rae 1a. ’ f ; ‘ 4s { 7 “ae i ; ‘ | Ly | ; « , a ‘ ie ei : | “7 * - , x. ea ie A i! t lige ai 4 be ve q i oF at ‘ * ° a 5 Ve - a +, P G é oe = +) 1 \ ‘ , = > a 7 4 i ; neh ood Mig : ; 4 , iM ae a ”') : 7 . A Al 4. 1 : } 4] ¥e 6 LU ‘ Fig. EXPLANATION OF PLATE XII. 30. BELEMNITES ILMINSTRENSIS, 0. s. d. a Lateral view of a fine specimen, with colour-bands, in the Collection of Mr. C. Moore. Ventral aspect of another example. Lateral aspect of a larger individual. Ventral aspect near the apex, showing a few striz. Dorsal aspect of the same. Dorsal aspect (apex rather decomposed). o v™. Series of ventral aspects in young examples. Transverse aspect of a septum. a section at the alveolar apex. 2 , toward the apex. " ,, Still nearer the apex. i »» Very near to the apex. Ventral aspect of the phragmocone, from which the conotheca is removed. Another example, showing the dorsal aspect, with peculiar marking ; this is magnified at 9”. Worn specimen of phragmocone, showing the shape of the siphuncle. Phragmocone iz situ, lateral aspect. Small, twin, or grouped egg-shaped prominences on the surface of the phragmocone, within the conotheca. PL . XII. Imp Becgoat a Paris. P. Lackerbauer lith. . 7 i. ’ tea ie y f : as 4 e. Ve DD | 4 i bel : x ‘ : I EXPLANATION OF PLATE XIII. Fie. 31. BELEMNITES MICROSTYLUS, nN. s. ce. Specimen belonging to the Geological Survey, and preserved in the Museum (No. 349”), Jermyn Street. Lyme Regis. ce’. Magnified view of the phragmocone and the enveloping sheath. o. Specimen in the Oxford Museum (part of Mr. Murley’s Collection) ; from the Upper Lias of Dumbleton. The apex is broken off, 32. BELEMNITES LonGIsstmus. (Lyme Regis.) . Seen laterally. o. ‘The striation at the apex. s. Transverse section. 33. BELEMNITES JUNCEUS, n.s. (Lyme Regis.) The transverse sections (s, s’) show concentric sheaths, with undulations corre- sponding to the grooves ; radiating fibres obscure. 3 34a. BELEMNITES NITIDUS, n.s. (Lyme Regis.) Lateral views (/). The transverse section (s’) shows the lateral undulations and almost central axis, 34.6. A shorter variety, which has some affinity to B. apicicurvatus. Lyme Regis. 35. BELEMNITES QUADRICANALICULATUS. (Upper Lias [Sands], Chidcock.) Specimens in the Museum of the Geological Survey, Jermyn Street. Mr. Moore’s Collection contains examples from the Upper Lias of Ilminster. v, v, Ventral; d, d’, dorsal; 7, 7’, lateral. PEL eI pans he pserquenastocaana natant seit tse Fig. dl. tmp Becguet 4 Paris. P Lackerbauer hth. ae atl : v ‘ - in i i y ¢ ae ' s ” - ‘ ' f ce \ 'e i i s Maint ; : 9 A 15 ¢ : : i 1 o . j : \ - \ . ni n - ‘ i sit ee al Go Nee kh Pr. iy 3 r . ’ i” Wi; yet eye ape fire oe eee ; oasis, Vie ra f 1 « : a 4 ) : 4 . 1) * \ 5 5 , ‘ > , * ‘ 4 4 - ‘ . U ’ ‘ 2? ca a « ® e « EXPLANATION OF PLATE XVI. Fic. 40. BeLemnites vuLearis. (From the Upper Lias of Whitby.) /. Lateral and (v) ventral aspects of an ordinary middle-aged specimen. s. Section across the alveolar cavity ; in this case the ventral wall is thickest. s’. Section at the alveolar apex. I’. Lateral view of a young example. s. Longitudinal section. ¢. Phragmocone, zz sitv, of a large specimen, with short axis of guard. 41. Lateral view of a somewhat longer individual. 42. BeLEMNites RuDIS, n. s. (From Staithes, near Whitby.) /. Lateral view of an ordinary specimen ; the upper outline is supposed to be the terminal edge. v and d mark the ventral and dorsal aspect at the alveolar apex. v. Ventral aspect of the same specimen, showing the obtuse and irregular groove. / and d’. Lateral and dorsal views of a young example, more lengthened than in the seniors. s. Section across the alveolar chamber. s’. Section at the alveolar apex, showing great excentricity. s”. Section nearer the apex of guard, showing less excentricity of axis. Os Et cae es Inp Becquet a Paris. ee ee EXPLANATION OF PLATE XVII. Fic. 43. Burumnires Vourzu, n.s. (Upper Lias, Whitby.) 7, Lateral view of a symmetrical specimen. d. Dorsal aspect of the same. v. Ventral aspect of the same. i”. Lateral view of a larger specimen. ¢. Phragmocone, seen laterally. ¢ . The same, seen dorsally. s. Transverse section at the alveolar apex. S * » hear the apex of the guard. 44, BELEMNITES VENTRALIS, n. s. (Upper Lias, Robin Hood’s Bay.) 1. Lateral view ; the apex worn. d. Dorsal view of the same. v. Ventral aspect of the same. The striation is seen on each. s. ‘Transverse section at the alveolar apex. »» , further along the guard. i », hear the apex of the guard. 45. Younger examples, with unworn apices. The points are striated. (Upper Lias, Whitby.) 1. Lateral view. v. Ventral view, to show the rather long groove. v’. Another specimen, in which only the faintest trace of such a groove appears. These three figures are not very easily distinguished from the young of Belemnites vulgaris. esieeeLeebon™ : Imp Becquet a Paris. - S wuer Lith. a Peseah > EXPLANATION OF PLATE XVIII. Fic. 46. BELEMNITES INoRNATUS, n. 8s. [ Without ventral groove.| Blue Wick, Robin Hood’s Bay. /’. Lateral view, showing the insertion of the phragmocone. Between d and v is the alveolar apex. /’. Lateral view of a specimen in which the grooves and striz are very obscure (worn). s. Longitudinal section, showing the slightly arched phragmocone, covered by the conotheca, zx setu. ‘I'ransverse section across the alveolar cavity. - ,, at the alveolar apex. Portion of the conotheca, seen dorsally. ”. Portion of the same, seen laterally. OO PL. XVIII. Pla RAS Lith. fnp Beequet a Paris. EXPLANATION OF PLATE XIX. Fie. 47. BELEMNITES LoNGISULCATUS. (Copied from Voltz’s figure, ‘ Obser. sur les Bélemn.,’ pl. vi, fig. 1.) 7. Lateral view. d. Dorsal view. v. Ventral view. 48. BELEMNITES INZQUISTRIATUS. (From the Upper Lias of Whitby.) Lateral view of a specimen in the Whitby Museum, “ No. 454.” Dorsal aspect of the same. Ventral aspect of the same. Enlarged view of the tripartite end. Shows the oval contour of the alveolar region, the ventral area being broadest. So Shs eRe 49. BELEMNITES SULCI-sTYLUs, n. s. (From Nailsworth [Sands].) PL. XIX: Se an RI Re OS ah ASANTE OR Fig. 47. Imp Becquet Z Pais. J feos a 8 - a7 uv 8 «s I 2 & | Q F N AY EXPLANATION OF PLATE XX. Fig. 50. BELEMNITES ELEGANS. /, Lateral view of a specimen in the Whitby Museum, “No. 967, Robin Hood’s Bay, north side.” /’. Lateral view of a specimen in Collection of Prof. Phillips. Hunteliff. d, v. Dorsal and ventral aspect of the same specimen. /’. Lateral view of a specimen in the Whitby Museum, “ No. 458, Robin Hood’s Bay.” s. ‘Transverse section. s. Longitudinal section of a specimen in Prof. Phillips’s Collection. Robin Hood’s Bay. 51. BELEMNITES SCABROSUS, N. S. /. Lateral view of a specimen in the Whitby Museum, “ No. 976.” From north side of Robin Hood’s Bay. d,v. Dorsal and ventral aspects. 52. P./. BeLEMNiTEs cyLinpRicus. Lateral view of a specimen from Rosedale (near Staithes), in beds below the Jet-rock. P.v, P. d. Ventral and dorsal view of the same. 52, M./. BELEMNITES PAXILLOSUS. M./. Ventral aspect of a specimen from the marlstone of Ilminster, in the Collection of Mr. Moore. (The figure should have been marked M. v. ; the slight seeming ventral groove near the apex is an accidental effect of the shading.) PL. XX eee Sf a npn semerd ahd soheael. A. ~~. — 79 ~shepge> ered sa pen oe sdgartetesies vated cca a Paris Lap Becquet P Lackerbauer lth. ae PARK, aay | \s, NEW cn sity RAL WIS Peres, '