Front Matter

CONTENTS OF VOL. 157. I. Discussion of Tide Observations at Bristol. By T. G. BUNT, Bristol. Communicated by the Astronomer Royal ......................................................... page 1 II. A Supplementary Memoir on Caustics. By A. CAYLEY, F.R.S. ............................................................. 7 III. On the Muscular Arrangements of the Bladder and Prostate, and the manner in which the Ureters and Urethra are closed. By JAMES BELL PETTIGREW, M.D. Edin., First Assistant in the Museum of the Royal College of Surgeons of England. Communicated by Dr. SHARPEY, Sec. R.S. .............................................. 17 IV. On the Dynamical Theory of Gases. By J. CLERK MAXWELL, F.R.S. L. & E. ....................................................................................................................................... 49 V. Experimental Researches in Magnetism and Electricity. By H. WILDE, Esq. Communicated by Dr. FARADAY ............................................................ 89 VI. On the Anatomy of the Fovea Centralis of the Human Retina. By J. W. HULKE, F.R.C.S., Assistant Surgeon to the Middlesex and Royal London Ophthalmic Hospitals. Communicated by WILLIAM BOWMAN, F.R.S. ................................................ 109 VII. On the Laws of Connexion between the Conditions of a Chemical Change and its Amount. By A. VERNON HARCOUETT, M.A., Student of Christ Church, and Demonstrator of Chemistry in the University of Oxford, and WILLIAM ESSON, M.A., Fellow of Merton College, Oxford. Communicated by Sir B. C. BRODIE, Bart., F.R.S., Professor of Chemistry in the University of Oxford ........................................... 117 VIII. Account of Experiments on Torsion and Flexure for the Determination of Rigidities. By JOSEPH D. EVERETT, D.C.L., Assistant to the Professor of Mathematics in the University of Glasgow. Communicated by Sir WILLIAM THOMSON, F.R.S. ................................................................................................................................. 139 IX. On the Structure of the Optic Lobes of the Cuttle-fish. By J. LOCKHART CLARKE, F.R.S., &c. ................................................................................................................. 155 X. Abstract of the Results of the Comparisons of the Standards of Length of England, France, Belgium, Prussia, Russia, India, Australia, made at the Ordnance Survey Office, Southampton. By Captain A. R. CLARKE, R.E., F.R.S., &c., under the Direction of Colonel Sir HENRY JAMES, R.E., F.R.S., &c., Director of the Ordnance Survey. With a Preface by Colonel Sir HENRY JAMES, R.E., F.R.S., &c. .................................................................................................................. 161 LIST OF ILLUSTRATIONS. Plates I. & II.—Mr. T. G. Bunt's Discussion of Tide Observations at Bristol. Plates III. to V.—Dr. Pettigrew on the Muscular Arrangements of the Bladder and Prostate. Plate VI.—Mr. H. Wilde's Experimental Researches in Magnetism and Electricity. Plate VII.—Mr. J. W. Hulke on the Anatomy of the Fovea Centralis of the Human Retina. Plate VIII.—Messrs. A. V. Harcourt and W. Esson on the Laws of Connexion between the Conditions of a Chemical Change and its Amount. Plate IX.—Dr. Everett on the Rigidity of Glass. Plate X.—Mr. J. Lockhart Clarke on the Structure of the Optic Lobes of the Cuttlefish. Plates XI. to XIV.—Mr. St. George Mivart on the Skeleton of the Primates. Plates XV. to XVIII.—Dr. W. H. Ransom on the Ovum of Osseous Fishes. Plate XIX.—Dr. G. Neumayer on the Lunar-diurnal Variation of the Magnetic Declination. Plate XX.—Professor Cayley's Eighth Memoir on Quantics. Plates XXI. & XXII.—Professor Roscoe on the Chemical Intensity of Total Daylight at Kew and Pará. Plates XXIII. to XXV.—Dr. Sanderson on the Influence exercised by the Movements of Respiration on the Circulation of the Blood. Plates XXVI. to XXVIII.—Dr. Günther on the Anatomy of Hatteria. Plates XXIX. & XXX.—Mr. W. H. Flower on the Development and Succession of the Teeth in Marsupialia. Plates XXXI. & XXXII.—Dr. P. M. Duncan on the Genera Heterophyllia, Battersbyia, Palaeocyclos, and Asterosmilia. The Committee appointed by the Royal Society to direct the publication of the Philosophical Transactions, take this opportunity to acquaint the Public, that it fully appears, as well from the Council-books and Journals of the Society, as from repeated declarations which have been made in several former Transactions, that the printing of them was always, from time to time, the single act of the respective Secretaries till the Forty-seventh Volume; the Society, as a Body, never interesting themselves any further in their publication, than by occasionally recommending the revival of them to some of their Secretaries, when, from the particular circumstances of their affairs, the Transactions had happened for any length of time to be intermitted. And this seems principally to have been done with a view to satisfy the Public, that their usual meetings were then continued, for the improvement of knowledge, and benefit of mankind, the great ends of their first institution by the Royal Charters, and which they have ever since steadily pursued. But the Society being of late years greatly enlarged, and their communications more numerous, it was thought advisable that a Committee of their members should be appointed, to reconsider the papers read before them, and select out of them such as they should judge most proper for publication in the future Transactions; which was accordingly done upon the 26th of March 1752. And the grounds of their choice are, and will continue to be, the importance and singularity of the subjects, or the advantageous manner of treating them; without pretending to answer for the certainty of the facts, or propriety of the reasonings, contained in the several papers so published, which must still rest on the credit or judgement of their respective authors. It is likewise necessary on this occasion to remark, that it is an established rule of the Society, to which they will always adhere, never to give their opinion, as a Body, upon any subject, either of Nature or Art, that comes before them. And therefore the thanks, which are frequently proposed from the Chair, to be given to the authors of such papers as are read at their accustomed meetings, or to the persons through whose hands they received them, are to be considered in no other light than as a matter of civility, in return for the respect shown to the Society by those communications. The like also is to be said with regard to the several projects, inventions, and curiosities of various kinds, which are often exhibited to the Society; the authors whereof, or those who exhibit them, frequently take the liberty to report and even to certify in the public newspapers, that they have met with the highest applause and approbation. And therefore it is hoped that no regard will hereafter be paid to such reports and public notices; which in some instances have been too lightly credited, to the dishonour of the Society. The Meteorological Journal hitherto kept by the Assistant Secretary at the Apartments of the Royal Society, by order of the President and Council, and published in the Philosophical Transactions, has been discontinued. The Government, on the recommendation of the President and Council, has established at the Royal Observatory at Greenwich, under the superintendence of the Astronomer Royal, a Magnetical and Meteorological Observatory, where observations are made on an extended scale, which are regularly published. These, which correspond with the grand scheme of observations now carrying out in different parts of the globe, supersede the necessity of a continuance of the observations made at the Apartments of the Royal Society, which could not be rendered so perfect as was desirable, on account of the imperfections of the locality and the multiplied duties of the observer. A List of Public Institutions and Individuals, entitled to receive a Copy of the Philosophical Transactions of each year, on making application for the same directly or through their respective agents, within five years of the date of publication. ### Observatories - Armagh - Cape of Good Hope - Dublin - Edinburgh - Greenwich - Kew - Liverpool - Madras - Oxford (Radcliffe) ### Institutions - Barbadoes Library and Museum - Calcutta Asiatic Society - Geological Museum - Cambridge Philosophical Society - Cape Town South African Library - Dublin Royal Dublin Society - Royal Irish Academy - Edinburgh Royal Society - London Admiralty Library - Chemical Society - Entomological Society - Geological Society - Geological Survey of Great Britain - Institution of Civil Engineers - Linnean Society - London Institution - Royal Asiatic Society - Royal Astronomical Society - Royal College of Surgeons - Royal College of Physicians - Royal Geographical Society - Royal Horticultural Society - Royal Institute of British Architects - Royal Institution of Great Britain - Royal Medical and Chirurgical Society - Royal Society of Literature - Society of Antiquaries - Society of Arts - The Queen's Library - The Treasury Library - The War Office - United Service Museum - Zoological Society - Malta Public Library - Manchester Literary and Philosophical Society - Melbourne University Library - Montreal McGill College - Oxford Ashmolean Society - Radcliffe Library - Swansea Royal Institution - Sydney University Library - Woolwich Royal Artillery Library ### Argentine Republic - Buenos Ayres Museo Publico ### Belgium - Brussels Académie Royale de Médecine - Académie Royale des Sciences ### Denmark - Copenhagen Kongelige Danske Videnskabernes Selskab ### France - Montpellier Académie des Sciences et Lettres - Faculté de Médecine - Paris Académie des Sciences de l'Institut - Dépôt de la Marine - Ecole des Mines - Ecole Normale Supérieure - Jardin des Plantes - Société Entomologique - Société de Géographie - Société Géologique - Société d'Encouragement pour l'Industrie Nationale - Toulouse Académie Impériale des Sciences ### Germany - Altona Die Sternwarte - Berlin Königliche Akademie der Wissenschaften - Physikalische Gesellschaft - Brünn Naturforschender Verein - Danzig Naturforschende Gesellschaft - Dresden Kaiserliche Leopoldino-Carolinische deutsche Akademie der Naturforscher - Frankfort Senckenbergische naturforschende Gesellschaft - Giessen Grossherzogliche Universität - Göttingen Königliche Gesellschaft der Wissenschaften - Gratz Naturwissenschaftliche Verein für Steiermark - Hamburg Naturwissenschaftlicher Verein - Königsberg Königliche physikalisch-ökonomische Gesellschaft A List of Public Institutions and Individuals, entitled to receive a Copy of the Philosophical Transactions of each year, on making application for the same directly or through their respective agents, within five years of the date of publication (continued). Leipzig .......... Königliche Sächsische Gesellschaft der Wissenschaften. Mannheim ....... Grossherzogliche Sternwarte. Munich .......... Königliche Bayerische Akademie der Wissenschaften. Prague .......... Königliche böhmische Gesellschaft der Wissenschaften. Vienna .......... Kaiserliche Akademie der Wissenschaften. Geologische Reichsanstalt. Würzburg ....... Physikalisch-medicinische Gesellschaft. Hungary. Pesth .......... Á Magyar Tudós Társaság—Die Ungarische Akademie der Wissenschaften. Italy. Bologna ......... Accademia delle Scienze dell’ Istituto. Catanea ......... Accademia Gioenia di Scienze Naturali. Florence ......... Reale Museo di Fisica. Milan .......... Reale Istituto Lombardo di Scienze, Lettere ed Arti. Modena .......... Società Italiana delle Scienze. Naples .......... Società Reale, Accademia delle Scienze. Palermo ......... Accademia di Scienze e Lettere. Rome .......... Accademia Pontificia de’ Nuovi Lincei. Osservatorio del Collegio Romano. Turin .......... Reale Accademia delle Scienze. Venice .......... I. R. Istituto Veneto di Scienze, Lettere ed Arti. Java. Batavia .......... Bataviaasch Genootschap van Kunsten en Wetenschappen. Netherlands. Amsterdam ...... Koninklijke Akademie van Wetenschappen. Haarlem ........ Hollandsche Maatschappij der Wetenschappen. Rotterdam ...... Bataafsch Genootschap der Proefondervindelijke Wijsbegeerte. Portugal. Lisbon .......... Academia Real das Sciencias. Russia. Kazan .......... Imperatorsky Kazansky Universitet. Moscow ......... Société Impériale des Naturalistes. Le Musée Publique. Pulkowa ......... Nikolai-Haupsternwarte. St. Petersburg .... Académie Impériale des Sciences. Spain. Cadiz .......... Observatorio de S. Fernando. Madrid .......... Real Academia de Ciencias. Sweden and Norway. Christiania ....... Kongelige Norske Frederiks Universitet. Trondhjem ....... Kongelige Norske Videnskabers Selskab. Gottenburg ...... Kongl. Vetenskaps och Vitterhets Samhälle. Stockholm ....... Kongliga Svenska Vetenskaps-Akademie. Switzerland. Bern ............ Allg. Schweizerische Gesellschaft. Geneva .......... Société de Physique et d’Histoire Naturelle. Institut National Genevois. Transylvania. Klausenburg ...... Az Erdélyi Muzeum—Das siebenbürgisches Museum. United States. Albany .......... New York State Library. Boston .......... American Academy of Sciences. Newhaven (Conn.) The Editors of the American Journal. Cambridge ...... Harvard University. Philadelphia ..... Academy of Natural Sciences. American Philosophical Society. Washington ...... Smithsonian Institution. U. S. Naval Observatory. The fifty Foreign Members of the Royal Society. A List of Public Institutions and Individuals, entitled to receive a Copy of the Astronomical Observations (including Magnetism and Meteorology) made at the Royal Observatory at Greenwich, on making application for the same directly or through their respective agents, within two years of the date of publication. | Observatories | Institutions | |------------------------|--------------------------------------------------| | Altona | Aberdeen University | | Armagh | Berlin Academy of Sciences | | Berlin | Boston American Academy of Sciences | | Breslau | Brunswick U.S. Bowdoin College | | Brussels | Cambridge Trinity College Library | | Cadiz | Cambridge U.S. Harvard University | | Cambridge | Dublin University | | Cape of Good Hope | Edinburgh University | | Coimbra | Royal Society | | Copenhagen | Glasgow University | | Dorpat | Göttingen University | | Dublin | Leyden University | | Edinburgh | London Board of Ordnance | | Helsingfors | Royal Institution | | Königsberg | Royal Society | | Madras | The Queen's Library | | Mannheim | Oxford Savilian Library | | Marseille | Paris Academy of Sciences | | Milan | Board of Longitude | | Munich | Dépôt de la Marine | | Oxford | Pesth Hungarian Academy of Sciences | | Palermo | Philadelphia American Philosophical Society | | Paris | St. Andrews University | | Seeberg | St. Petersburg Imperial Academy | | Tübingen | Stockholm Royal Academy of Sciences | | Turin | Upsal Royal Society | | Vienna | Waterville, Maine (U.S.) College | | Wilna | | | Individuals | | |------------------------|--------------------------------------------------| | Lowndes' Professor of Astronomy | Cambridge | | Plumian Professor of Astronomy | Cambridge | | President of the Royal Society | London | | South, Sir James | Kensington | | The Earl of Rosse | Parsonstown | A List of Observatories, Institutions and Individuals, entitled to receive a Copy of the Magnetical and Meteorological Observations made at the Royal Observatory, Greenwich. ### Observatories - **Bombay** .................................. C. Chambers. - **Cambridge, United States** ........ Prof. J. Lovering. - **Christiania** ............................. C. Hansteen. - **Gotha** .................................... P. A. Hansen. - **Heidelberg** .............................. M. Tiedemann. - **Kew** ....................................... B. Stewart. - **Kremsmünster** ......................... P. A. Reslhuber. - **Leipzig** ................................... Dr. C. Bruhns. - **Lisbon** .................................... Senhor da Silveira. - **Marburg** .................................. Prof. C. L. Gerling. - **Prague** .................................... K. Jelinek. - **Stockholm** ............................... Professor H. Selander. - **St. Petersburg** ......................... (Twelve copies for distribution to the Russian Mag. and Met. Obs.) - **The Compass Observatory,** Capt. Belavenetz. - **Toronto** .................................. Professor Kingston. - **Upsal** ...................................... Professor Svanberg. - **Washington** .............................. Admiral C. H. Davis. ### Institutions - **Bombay** .................................. Geographical Society. - **Bonn** ...................................... University. - **Boston, U.S.** ............................. The Public Library (late Bowditch). - **Cambridge** ............................... Philosophical Society. - **Cherkow** .................................. University. - **Falmouth** ................................. Royal Cornwall Polytechnic Society. - **London** .................................... House of Lords, Library. - **House of Commons, Library.** - **King's College.** - **Royal Society.** - **University College, Library.** - **Meteorol. Office, Board of Trade.** - **Paris** ...................................... Meteorological Society. - **St. Bernard** ............................... Convent. - **Washington** .............................. Smithsonian Institution. - **Woolwich** ................................. Office of Mag. and Met. Publication. ### Individuals - **Buys Ballot, Dr.** ...................... Utrecht. - **Dove, Prof. H. W.** ...................... Berlin. - **Erman, Dr. Adolph** .................... Berlin. - **Fox, R. W., Esq.** ....................... Falmouth. - **Hoskins, Dr. S. E.** ..................... Guernsey. - **Kaemtz, Prof. L. F.** ................... Dorpat. - **Lloyd, Rev. Dr.** ......................... Dublin. - **Loomis, Prof. E.** ....................... Yale College, Newhaven (Conn.). - **Phillips, Prof. John** ................... Oxford. - **Quetelet, A.** ............................. Brussels. - **Sabine, Lieut.-General, R.A.** .... London. - **Souza, Senhor da** ...................... Coimbra. - **Wartmann, Prof. Elie** ............... Geneva. - **Younghusband, Col., R.A.** .......... Woolwich. CONTENTS. I. Discussion of Tide Observations at Bristol. By T. G. Bunt, Bristol. Communicated by the Astronomer Royal . . . . . . . . . . . . . . . . . page 1 II. A Supplementary Memoir on Caustics. By A. Cayley, F.R.S. . . . . . . . . 7 III. On the Muscular Arrangements of the Bladder and Prostate, and the manner in which the Ureters and Urethra are closed. By James Bell Pettigrew, M.D. Edin., First Assistant in the Museum of the Royal College of Surgeons of England. Communicated by Dr. Sharpey, Sec. R.S. . . . . . . . . . . . . . . 17 IV. On the Dynamical Theory of Gases. By J. Clerk Maxwell, F.R.S. L. & E. . 49 V. Experimental Researches in Magnetism and Electricity. By H. Wilde, Esq. Communicated by Dr. Faraday . . . . . . . . . . . . . . . . . . 89 VI. On the Anatomy of the Fovea Centralis of the Human Retina. By J. W. Hulke, F.R.C.S., Assistant Surgeon to the Middlesex and Royal London Ophthalmic Hospitals. Communicated by William Bowman, F.R.S. . . . . . . . . . . 109 VII. On the Laws of Connexion between the Conditions of a Chemical Change and its Amount. By A. Vernon Harcourt, M.A., Student of Christ Church, and Demonstrator of Chemistry in the University of Oxford, and William Esson, M.A., Fellow of Merton College, Oxford. Communicated by Sir B. C. Brodie, Bart., F.R.S., Professor of Chemistry in the University of Oxford . . . . . . . . . . . . 117 VIII. Account of Experiments on Torsion and Flexure for the Determination of Rigidities. By Joseph D. Everett, D.C.L., Assistant to the Professor of Mathematics in the University of Glasgow. Communicated by Sir William Thomson, F.R.S. . . . . . . . . . . . . 139 IX. On the Structure of the Optic Lobes of the Cuttle-fish. By J. Lockhart Clarke, F.R.S., &c. . . . . . . . . . . . . . . . . . . . . . . 155 X. Abstract of the Results of the Comparisons of the Standards of Length of England, France, Belgium, Prussia, Russia, India, Australia, made at the Ordnance Survey Office, Southampton. By Captain A. R. Clarke, R.E., F.R.S., &c., under the Direction of Colonel Sir Henry James, R.E., F.R.S., &c., Director of the Ordnance Survey. With a Preface by Colonel Sir Henry James, R.E., F.R.S., &c. . . 161 XI. The Bakerian Lecture.—Researches on Gun-cotton.—Second Memoir. On the Stability of Gun-cotton. By F. A. Abel, F.R.S., V.P.C.S. . . . . . . . . . . . . 181 XII. On the Orders and Genera of Ternary Quadratic Forms. By Henry J. Stephen Smith, M.A., F.R.S., Savilian Professor of Geometry in the University of Oxford . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 MDCCLXVII. LIST OF ILLUSTRATIONS. Plates I. & II.—Mr. T. G. Bunt's Discussion of Tide Observations at Bristol. Plates III. to V.—Dr. Pettigrew on the Muscular Arrangements of the Bladder and Prostate. Plate VI.—Mr. H. Wilde's Experimental Researches in Magnetism and Electricity. Plate VII.—Mr. J. W. Hulke on the Anatomy of the Fovea Centralis of the Human Retina. Plate VIII.—Messrs. A. V. Harcourt and W. Esson on the Laws of Connexion between the Conditions of a Chemical Change and its Amount. Plate IX.—Dr. Everett on the Rigidity of Glass. Plate X.—Mr. J. Lockhart Clarke on the Structure of the Optic Lobes of the Cuttlefish. ADJUDICATION of the Medals of the Royal Society for the year 1867 by the President and Council. The Copley Medal to Karl Ernst von Baer, of St. Petersburg, For. Mem. R.S., for his discoveries in Embryology and Comparative Anatomy, and for his Contributions to the Philosophy of Zoology. A Royal Medal to Messrs. John Bennet Lawes, F.R.S., and Dr. Joseph Henry Gilbert, F.R.S., for their Researches in Agricultural Chemistry. A Royal Medal to Sir William Edmond Logan, F.R.S., for his Geological Researches in Canada, and the Construction of a Geological Map of that Colony. The Bakerian Lecture was delivered by Frederick Augustus Abel, F.R.S.; it was entitled "Researches on Gun-cotton.—Second Memoir. On the Stability of Gun-cotton." The Croonian Lecture was delivered by Dr. J. Burdon Sanderson; it was entitled "On the Influence exercised by the Movements of Respiration on the Circulation of the Blood." LIST OF ILLUSTRATIONS. Plates XI. to XIV.—Mr. St. GEORGE MIVART on the Skeleton of the Primates. Plates XV. to XVIII.—Dr. W. H. RANSOM on the Ovum of Osseous Fishes. Plate XIX.—Dr. G. NEUMAYER on the Lunar-diurnal Variation of the Magnetic Declination. Plate XX.—Professor CAYLEY’s Eighth Memoir on Quantics. Plates XXI. & XXII.—Professor ROSCOE on the Chemical Intensity of Total Daylight at Kew and Pará. Plates XXIII. to XXV.—Dr. SANDERSON on the Influence exercised by the Movements of Respiration on the Circulation of the Blood. Plates XXVI. to XXVIII.—Dr. GÜNTHER on the Anatomy of *Hatteria*. Plates XXIX. & XXX.—Mr. W. H. FLOWER on the Development and Succession of the Teeth in Marsupialia. Plates XXXI. & XXXII.—Dr. P. M. DUNCAN on the Genera *Heterophyllia*, *Battersbyia*, *Palaeocyclus*, and *Asterosmilia*. CONTENTS. XIII. On the Appendicular Skeleton of the Primates. By St. George Mivart, F.L.S., Lecturer on Comparative Anatomy at St. Mary’s Hospital. Communicated by Professor Huxley, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 299 XIV. Observations on the Ovum of Osseous Fishes. By W. H. Ransom, M.D. Communicated by Dr. Sharpey, Sec. R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 XV. On the Lunar-diurnal Variation of the Magnetic Declination, with special regard to the Moon’s Declination. By G. Neumayer. Communicated by the President . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 XVI. An Eighth Memoir on Quantics. By A. Cayley, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 XVII. On the Chemical Intensity of Total Daylight at Kew and Pará, 1865, 1866, and 1867. By Henry E. Roscoe, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555 XVIII. The Croonian Lecture.—On the Influence exercised by the Movements of Respiration on the Circulation of the Blood. By J. Burdon Sanderson, M.D., F.R.C.P. Communicated by Dr. Sharpey, Sec. R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571 XIX. Contribution to the Anatomy of Hatteria (Rhynchocephalus, Owen). By Albert Günther, M.A., Ph.D., M.D. Communicated by Professor Owen, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595 XX. On the Development and Succession of the Teeth in the Marsupialia. By William Henry Flower, F.R.S., F.R.C.S., &c., Conservator of the Museum of the Royal College of Surgeons of England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631 XXI. On the Genera Heterophyllia, Battersbyia, Palaeocyclos, and Asterosmilia; the Anatomy of their Species, and their Position in the classification of the Sclerodermic Zoantharia. By P. Martin Duncan, F.G.S., Secretary to the Geological Society. Communicated by Professor Huxley, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643 XXII. Researches into the Chemical Constitution of Narcotine, and of its Products of Decomposition.—Part II. By A. Matthiessen, F.R.S., Lecturer on Chemistry in St. Mary’s Hospital Medical School, and G. C. Foster, B.A., Professor of Physics in University College, London . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669 APPENDIX. Presents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [ 1 ]