Perwy Watala are ie hs At oa a on % LA of : 5 i a hah WN taP dn lb ‘ ii Al UNE p Khe wd en ALA A tte WE ae dt ran Teg dal ‘ 4 te om caw Ga Ca ad ‘a. 4 a A jy ae y 4 § q i CaCO REMORSE Rca wa TN fits, ue ; 4 fe Let he Ta TH WA ey AN yi ea yen Oa amey | Ce rea sat hesetaahatad Ae eran at ey Ife, Aaa hed AA i ie BA a Te 8 Wah ne one ei | i bidata CEMA ib a, ve ot ted Sas f) one iva baits Ube tty Bib ay itis i ae Lt A ei sith) eee Sigal Ue ee jae cath y He Ris VE fe ie an Wea % Gaps 41 4a mM gains oie a) 4 ae ai, ' eey asa wis Sa te be 2 Pe Me iste ate sat " ane ie ; i be ae Lick iH enter tiga a ; ik A Yike Se ga by Ry Anh Re ca thet uh vi i ‘bey t > nie eh ‘ tes xa bone iy yi Mitt Bit i yi Pe tt Mie Uy wie iis ay ie ee ty) Fina te Sue Waa eae ~~ ; I oe u ; + i : } F Sef / iu in a 5 = i. yy : ; P 2 y } ‘ ~ ‘ ‘ bomen x an r , i . “ ; -_ « . 1 ~ : A _ iJ wv / 6, : A | \ } ~ ; N° ay ? f PROCEEDINGS AND AN TRANSACTIONS OF THE LIVERPOOL BIOLOGICAL SOCIETY. WOIE, 2OE SESSION 1906-1907. LIVERPOOL: C. Tinting & Co., Lrp., Printers, 53, Vicroria STREET. oO ier CONTENTS. I.—-PRocEEDINGS. Office-bearers and Council, 1906-1907 . Report of the Council . Summary of Proceedings at the Meetings List of Members . ‘Treasgurer’s Balance Sheet . TI.—TRansactions. Presidential Address—‘‘ Some Problems of the Sea.”’ By Prof. W. A. Herpmay, F.R.S. Twentieth Annual Report of the Liverpool Marine Biological Committee and their Biological Station at Port Erin. By Prof. W. A. Herpmay, D.Sc., F.R.S. “Tigia”’ (L.M.B.C. Memoir No. XIV.) By C. Gorpon Hewitt, B.Sc. Report on the Investigations carried on during 1906, in connection with the Lancashire Sea-Fisheries Laboratory, at the University of Liverpool, and the Sea-Fish Hatchery at Piel, near Barrow. By Prof. W. A. Hurpmay, D.Sc., F.R.S8., AnpRew Scott, A.L.8., and James Jonnstone, B.Sc. “ Antedon ” (L.M.B.C. Memoir No. XV.) By Herperr C. CHAapDwIck. 21 65 101 371 PROCEEDINGS OOL BIOLOGICAL SOCIETY. a bi. i =a 7 > aa! ‘ J ’ ri ‘a ‘ a) 2 \ : 4 + u 7 . mM bs 4 7 bd 7 a i 7 “7 ¢ =e y " zr A. ee oe a - a .- 5 — . OFFICH-BEARERS AND COUNCIL. Gx-Presidents : 1886—87 Pror. W. MITCHELL BANKS, M.D., F.R.C.S. 1887—88 J. J. DRYSDALE, M.D. 1888—89 Pror. W. A. HERDMAN, D.Sc., F.R.S.E. 1889—90 Pror. W. A. HERDMAN, D.Sc., F.R.S.E. 1890—91 T. J. MOORE, C.M.Z.S. 1891—92 T. J. MOORE, C.M.Z.S. 1892—93 ALFRED O. WALKER, J.P., F.L.S. 1893—94 JOHN NEWTON, M.R.C.S. 1894—95 Pror. F. GOTCH, M.A., F.R.S. 1895—96 Pror. R. J. HARVEY GIBSON, M.A. 1896—97 HENRY O. FORBES, LL.D., F.Z.S. 1897—98 ISAAC C. THOMPSON, F.L.S., F.R.M.S. 1898—99 Pror. C. S. SHERRINGTON, M.D., F.R.S8. 1899—1900 J. WIGLESWORTH, M.D., F.R.C.P. 1900—1901 Pror. PATERSON, M.D., M.R.C.S. 1901—1902 HENRY C. BEASLEY. 1902—1903 R. CATON, M.D., F.R.C.P. 19083—1904 Rev. T. S. LEA, M.A. 1904—1905 ALFRED LEICESTER. 1905—1906 JOSEPH LOMAS, F.G.S. SESSION XXL, 1906-1907. President : Pror. W. A. HERDMAN, D.Sc., F.B.S. Dice- Presidents : ALFRED LEICESTER. JOSEPH LOMAS, F.G.S. Hon. Creasurer : Hon, Librarian : Vie die deUM i Wise JAMES JOHNSTONE, B.Sc. Hon. Secretary: JOSEPH A. CLUBB, M.Sc. Council : HENRY C. BEASLEY. R. NEWSTEAD, F.L.S. R. CATON, M.D. diz dal, COMCGOININIGIbIL, Ile ORles W. J. HALLS. JOSEPH PEARSON, M.Sc. OULTON HARRISON. ALFRED QUAYLE. ies EbAY DON. Pror. SHERRINGTON, F.R.S. W. §. LAVEROCK, M.A., B.Sc. L. R. THORNELY ‘Miss). Representative of Students’ Section: W. DAKIN, B.Sc. Vill. LIVERPOOL BIOLOGICAL SOCIETY. REPORT of the COUNCIL. The past session has been a memorable one in the annals of the Society. In the first place, during this session the Society celebrated by a most interesting and successful function, its twenty-first year of work, and secondly, for the first time the student members of the Society organised themselves as a distinct section. The “Coming of Age” celebration was held on January 25th, and took the form of a Scientific Con- versazione (see “ Proceedings,” p. xi.) held in the Zoology buildings of the University. In addition to members of the Society and their friends, a number of representative citizens and many scientific men from other centres were invited, and took part in the proceedings. The Society is very much indebted to the distinguished visitors who so kindly brought interesting exhibits and delivered addresses, and at the next succeeding meeting of the Council the following resolution was passed :—-“ That the cordial thanks of the Council of the Society be accorded to Prof. Poulton, Mr. Stanley Gardiner, Prof. Cossar Ewart and Mr. R. C. Punnett for their great kindness in con- tributing so much to the interest of the function which was held in celebration of the coming of age of the Society.” Under the stimulating influence of Mr. Pearson and Mr. Douglas Laurie, an unusually large number of junior and senior students of the Zoology Department of the University joined the Society as student members, and, with the sanction of the Council, these members were organised into a “ Students’ Section,” holding supplemen- tary meetings under officials of their own electing, and REPORT OF THE COUNCIL. 1X. having a representative on the Council of the parent Society. The membership of the Students’ Section is 48, and 11 meetings were held in addition to the ordinary meetings of the Society. The communications made to the Society at the ordinary meetings have been representative of almost all branches of Biology, and the various exhibitions and demonstrations thereon have been of great interest. The Library continues to make satisfactory progress, and additional important changes have been arranged. The Treasurer's statement and balance-sheet are appended. The members at present on the roll are as follows : — Honorary members - - - - - - 8 Ordinary members” - - - - - - 66 Associate members” - - - - - - 38 Student members, including Students’ Section - 60 otal a + 116 y/ xX. LIVERPOOL BIOLOGICAL SOCIETY. SUMMARY of PROCEEDINGS at the MEETINGS. The first meeting of the twenty-first session was held at the University, on Saturday, October 27th, 1906. The President-elect (Prof. Herdman, D.Sc., F.R.S.) took the chair in the Zoology Theatre. 1. The Report of the Council on the Session 1905-1906 (see “ Proceedings,” Vol. XX., p. vill.) was sub- mitted and adopted. 2. The Treasurer’s Balance Sheet for the Session 1905- 1906 (see “ Proceedings,’ Vol. XX., p. xvail.) was submitted and approved. ) 3. The following Office-bearers and Council for the ensuing Session were elected :—Vice-Presidents, Joseph Lomas, F'.G.8., and Alfred Leicester; Hon. Treasurer, T. C. Ryley; Hon. Librarian, James Johnstone, B.Sc.; Hon. Secretary, Joseph A. Clubb, M.Se.; Council, H. C. Beasley, R. Caton, M.D., W. J. Halls, Oulton Harrison, W. T. Haydon, W.S. Laverock, M.A., B.Sc., R. Newstead, F.L.S., J. H. O'Connell, L.R.C.P., Joseph Pearson, M.8c., Alfred Quayle, and Professor Sherrington, F.R.S. 4. Professor Herdman delivered the Presidential Address on “Some Problems of the Sea” (see “ Transac- tions,’ p. 1). A vote of thanks was proposed by Mr. Alfred Leicester, seconded by Dr. O’Connell, and carried with acclamation. SUMMARY OF PROCEEDINGS AT MEETINGS. Sle The second meeting of the twenty-first session was held at the University, on Friday, November 9th, 1906. The President in the chair. 1. Mr. H. C. Chadwick submitted the Annual Report on the work of the Liverpool Marine Biology Com- mittee and the Port Hrin Biological Station (see “Transactions,” p. 21). The third meeting of the twenty-first session was held at the University, on Friday, December 14th, 1906. The President in the chair. 1. Mr. C. Gordon Hewitt, B.Sc., submitted the L.M.B.C. Memoir on the anatomy and physiology of Liga oceamca (see “Transactions,” p. 69). 2. Mr. W. Dakin, B.Sc., gave a note on the swimming of Pecten from observations made at the Biological Station, Port Erin. In celebration of the 21st session of the Society, a highly successful function, in the form of a Scientific Conversazione, was held in the University on January 20th, 1907. On the invitation of the President and Council, a large and distinguished gathering assembled, and was received by the President and Mrs. Herdman in the Museum of the Zoology Department. The guests included many leading citizens, representatives of the sister societies of the City and of Manchester, Chester, Xl. LIVERPOOL BIOLOGICAL SOCIETY. Southport, and other towns, as well as distinguished representatives from the Universities of Oxford, Cam- bridge, Edinburgh, Belfast, Manchester, Sheffield, and London. After the reception, a short meeting was held in the Theatre, where the President welcomed the guests and _ referred to the importance of the occasion. Short addresses of a congratulatory nature were given by Sir Charles Hliot, Vice-Chancellor of Sheffield University, Principal Dale and Professor Poulton, of Oxford. Dr. Caton, as a past-President of the Society, responded. The following lecturettes and demonstrations were afterwards given :—By Mr. R. C. Punnett (Cambridge) on ‘The New Heredity.” By Prof. Poulton, F.R.S. (Oxford), on “The most wonderful example of Mimicry in the world,” illustrated by the electric lantern. By Prof. Cossar Ewart, F.R.S. (Edinburgh), Exhibition and Demonstration of Horses’ Skulls recently dug up from a Roman camp. By Mr. J. Stanley Gardiner (Cambridge), Leader of the recent expedition in the Indian Ocean, on “The Seychelles,” illustrated by the electric lantern. The following Exhibitions were laid out in the various rooms, and were explained at intervals during the evening: —(Mr. J. Johnstone)—Marked fish, otoliths, bacteriology, models, &e. (Miss Allen)—Exhibition of books, and the Society’s publications. Exhibition of original drawings and proof plates. Collections of Tuni- cata and Pearl Oysters. (Mr. Douglas Laurie)—Collection of Ceylon Crabs classified, with demonstration of dimorphic forms. Exhibition of Antarctic photographs by Mr. W. S. Bruce, Leader of the “ Scotia’ Expedition. (Mr. J. E. S. Moore)—Microscopic demonstrations of the maturation of the ovum. (Mr. Newstead)—Exhibit SUMMARY OF PROCEEDINGS AT MEETINGS. X11. illustrating Insects and Disease. (Mr. Pearson)—Exhibi- tion of microscopic objects. (Mr. Dakin)—Incubation of Eggs, collection of Oceanic Oozes, &e. The fifth meeting of the twenty-first session was held at the University, on Friday, February 8th, 1907. The President in the chair. 1. Prof. Herdman gave a short note on “A Further Problem of the Sea,” dealing with the distribution of marine animals on the Maldive Islands and the coast of Ceylon. 2. Mr. J. Johnstone, B.Sc., submitted the Annual Report of the Investigations carried on during 1906 in connection with the Lancashire Sea Fisheries Committee (see “ Transactions,” p. 101). The sixth meeting of the twenty-first session was held at the University, on Friday, March 8th, 1907. The President in the chair. 1. Mr. R. Douglas Laurie, B.A., communicated a paper on “ Biometric Methods in relation to Evolution.” A discussion followed. a. The President submitted the L.M.B.C. memoir on “ Antedon,’ by Mr. H. C. Chadwick (see “ Tran- sactions,”’ p. 371). XLV. LIVERPOOL BIOLOGICAL SOCIETY. The seventh meeting of the twenty-first session was held at the University, on Friday, May 10th, 1907. The President in the chair. 1. In the absence of Dr. O’Connell, the Secretary exhibited, with remarks, some of his teresting hving reptiles. 2. Mr. J. Pearson, M.Sc., communicated a paper on “Hedysis and Regeneration of lost limbs in Crustacea.” An interesting discussion followed the reading of the paper. The eighth meeting of the twenty-first session was the Annual Field Meeting held at Hilbre Island, on Wednesday, May 29th, in conjunction with the Manchester University Biological Socrety. At the short business meeting held after tea, on the motion of Professor Herdman from the chair, seconded by Dr. O'Connell, Mr. W. T. Haydon was unanimously elected President for the ensuing session. LIST of MEMBERS of the LIVERPOOL ELECTED. 1888 1903 1894 1889 1886 1886 1902 1905 1903 1902 1905 1886 1902 1903 1886 1901 BIOLOGICAL SOCIETY. SHSSION 1906-1907. A. Orpinary MEMBERS. (Life Members are marked with an asterisk.) Beasley, Henry C., Prince Alfred Road, Wavertree. Booth, jun., Chas., 30, James Street, Liverpool. Boyce, Prof., University, Liverpool. Brown, Prof. J. Campbell, 8, Abercromby Square. Caton, R., M.D., F.R.C.P., 78, Rodney Street. Clubb, J. A., M.Sc., Hon. Srcretrary, Free Public Museums, Liverpool. Cowley, R. C., 6, Sandon Terrace, Liverpool. Cussans, Miss M., B.Sc., Edge Hill Training College, Liverpool. Dixon-Nuttall, F. R., Ingleholme, Eccleston Park, Prescot. Deacon, H. Wade, 8, Ullet Road, Liverpool. Drabble, Dr. Eric, Hartley Laboratories, Univer- sity. Gapsen, Prot. R.. J. Harvey, M.A. F.LS., University, Liverpool. Glynn, Dr. Ernest, 67, Rodney Street. Guthrie, Thomas, 8, Canning Street, Liverpool. Halls, W. J., Hon. Treasurer, 35, Lord Street. Hanna, W., M.A., M.B., 80, Marmion Road, Liverpool. aval 1896 1886 1893: 1897 1902 1903 1903 1900 1904 1898 1903 1886 19035 1894 1886 1896 1906 1886 1905 1905 1905 1904 1888 1900 LIVERPOOL BIOLOGICAL SOCIETY. Haydon, W. T., 135, Bedford Street S. Herdman, Prof. W. A., D.Se., F.R.S., Presmpent, University, Liverpool. Herdman, Mrs. W. A., Croxteth Lodge, Ullet Road, Liverpool. | Holt, Alfred, Crofton, Aigburth. Holt, A., jun., Crofton, Aigburth. Holt, George, 5, Fulwood Park, Liverpool. Holt, Richard D., 1, India Buildings, Liverpool. Horsley, Dr. Reg., Stonyhurst, Blackburn. Jenkins, J. T., D.Sc, Ph.D., Fisheries Office Preston. Johnstone, James, B.Sc., Hon. Liprartan, University, Liverpool. Jones, Sir Alfred L., African House, Water Street. Jones, Charles W., Allerton Beeches, Liverpool. Jones, Dr. Robert, 11, Nelson Street, Liverpool. Liea, Rev. T. S., M.A., Leek Vicarage iene Lonsdale. Leicester, Alfred, Vice-PREsIDENT, 148, Liscard Road, Liscard. Laverock, W. S., M.A., B.Se., Free Museums, Liverpool. Laurie, R. Douglas, B.A., University, Liverpool. Lomas, J., F.G.S., Vicz-PresipEnt, 18, Moss Grove, Birkenhead. Moore, J. E. S., 25, Croxteth Road, Liverpool. Moore, Prof. B., University, Liverpool. Mountmorres, The Hon. Viscount. Institute of Tropical Research, The Museum, Liverpool. Newstead, R., A.L.S., School of Tropical Medicine, Liverpool. Newton, John, M.R.C.S., 2, Prince’s Gate, W. Nisbet, Dr., 7, Croxteth Road, Liverpool. 1904 1904 1894 1894 1905 1903 1897 1903 1903 19035 1890 1887 1894 1895 1886 1895 19038 1903 1903 1905 1889 1905 1888 LIST OF MEMBERS. XVI. O’Connell, Dr. J. H., .88, Heathfield Road, Liverpool. Pallis, Miss M., Tatoi1, Aigburth Drive, Liverpool Paterson, Prof., M.D., M.R.C.S., University, Liverpool. Paul, Prof. F. T., Rodney Street, Liverpool. Pearson, J., M.Se, Zoological Department, Liverpool. Petrie, Sir Charles, 7, Devonshire Road, Liverpool. Quavle, Alfred, 7, Scarisbrick New Road, Southport. Rankin, J., 67, South John Street, Liverpool. Rathbone, H. R., Oakwood, Aigburth. Rathbone, Herbert R., C.C., 15, Lord Street, Liverpool. *Rathbone, Miss May, Backwood, Neston. Ryley, Thomas C., 10, Waverley Road. Scott, Andrew, Piel, Barrow-in-Furness. ‘Sherrington, Prof., M.D., F.R.S., University, Liverpool. Smith, Andrew T., 5, Hargreaves Road, Sefton Park. Smith, J.. F.L.S8, Hood Lane, Sankey Bridge, Warrington. | Stapledon, W. C., 2, Marine Park, West Kirby. Thomas, Dr. H. Wolferstone, School of Tropical Medicine, Liverpool. Thomas, Dr. Thelwall, 84, Rodney Street, Liverpool. Thompson, Edwin, 1, Croxteth Grove, Liverpool. Thornely, Miss L. R., Nunclose, Grassendale. Timmis, ’. Sutton, Cleveley, Allerton, Liverpool. Toll, J. M., 49, Newsham Drive, Liverpool. XV111. LIVERPOOL BIOLOGICAL SOCIETY. 1903 Walker, Horace, South Lodge, Princes Park. 1891 Wiglesworth, J., M.D., F.R.C.P., County Asylum, Rainhill. 1896 Willmer, Miss J. H., 20, Lorne Road, Oxton, Birkenhead. B AssoctatTE MEMBERS. 1903 Tattersall, W., B.Sce., Marine Lab., Moyard, Letterfrack, Co. Galway. 1905 Harrison, Oulton, Denehurst, Victoria Park, © Wavertree. 1905 Carstairs, Miss, 39, Lilley Road, Fairfield. C Strupent MEMBERS. Adams, A., Zoological Department, University. Arnett Dear, A., Edgeworth, Bebington. Bishop, G. 8S. A., 4, Richmond Terrace, Everton. Bramley-Moore, J., 138, Chatham Street. Clothier, H. M., Zoological Department, University. Greenwood, Miss F. V., Edge Hill Training College, Durning Road. Hannah, J. H. W., 55, Avondale Road, Sefton Park. Hudson, Miss K. B., University Hall, Beech Street. Ponsonby, Miss F., Edge Hill Training College, Durning Road. Scott, Miss D., University Hall, Beech Street. Shipperbottom, Miss L., Edge Hill Training College, Durning Road. Summers, Miss B., Edge Hill Training College, Liverpool. LIST OF MEMBERS. XIX. University StuprEnts’ SEcTION. Chairman: W. Dakin, B.Se. Hon. Secretary: J. Davidson. Members : Misses A. Nicholls, A. Owen, E. Hirst, D. Moss, M. C. Mandale, EK. Stopford, M. Hodgkinson, A. Prescott, EK. Mathewman, A. Kenyon, K. Winston, G. Mitchell, M. Cheetham, E. Bury, M. K. Kaye, M. L. Whitehurst, M. K. Johnston, W. Herdman, and E. Norris. Messrs. J. A. Griffiths, J. D. Webb, R. W. Gemmell, F.G. F. Browne, H. Nield, N. Laing, R. Heald, R. Kennon, A. Williamson, J. Davidson, H. V. Forster, A. L. Oluwole, T. Hayhurst, R. H. Knowles, C. A. Bernard, M. T. Morgan, D. H. Clarke, EH. EH. Billington, C. Kennedy, R. C. Crooke, 8. N. Wright, H. Jones, J. Loudon, W. Parry, H. G. Roberts, F. A. Martin, H. VY. Pedlar, M. Pallis, and A. Holmes. D Honorary MEMBERS. * S.A.S., Albert I., Prince de Monaco, 20, Faubourg St. Honore, Paris. Bornet, Dr. Edouard, Quai de la Tournelle 27, Paris. Claus, Prof. Carl, University, Vienna. Fritsch, Prof. Anton, Museum, Prague, Bohemia. Giard, Prof. Alfred, Sorbonne, Paris. Haeckel, Prof. Dr. E., University, Jena. Hanitsch, R., Ph.D., Raffles Museum, Singapore. Solms-Laubach, Prof.-Dr., Botan. Instit., Strassburg. 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By Proressor W. A. Herpman, F.R.S., PRESIDENT. (Read 26th October, 1906.) I beg to acknowledge, with proper gratitude, the honour you have done me in electing me once more to the Presidential chair of our Society. You are aware that at the end of the present session we attain our majority. Our meeting next January will be the twenty-first since the Society was founded; and, as the senior surviving past-president, it was perhaps appropriate that I should be asked to re-occupy the chair for the occasion. As I desire to ask the Council to allow me later in the session to arrange a suitable celebration of our twenty-first year of work, I shall not occupy your time further now with remarks which may be more appropriate to that occasion. I have already given two Presidential Addresses to this Society, and on thinking of what might be suitable matters to occupy you with on this third occasion I decided that 1t might be well, in place of taking one specific subject, to deal with two or three general questions of wide interest to all biologists, I hope, and possibly to others outside our bounds. That leads me to ask—Why are there not more within our bounds? This Society is too small. When we consider the wide scope and the deep interest of biological investigations, and their practical importance to mankind in connection with food supply and the public health—in addition to many industries, such as that of the oriental pearl, which enriches man by enhancing the beauty of woman —when 2 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. we remember that this Society embraces every branch of Zoology, Botany, Physiology, Paleontology, Geographical Distribution and many Practical Applications of these subjects, it is distinctly disappointing to find that the vast population of Liverpool yields us less than a hundred members. The scientific man likes to think that all things can be explained—sooner or later; and probably the explana- tion of this curious circumstance is simple enough, but involves several reasons. The reason that prevents one man who would be interested in our meetings from joining us is not the reason that deters another. Leisure time for science in the lives of those who have other professions is, with the multifarious pursuits of modern life, more limited than it used to be. We all have many engagements and more or less urgent calls upon our spare time and surplus energy, which become more exacting as we get on in life. Other more special societies—Entomological, Concho- logical, Geological, Microscopical—call off some who would otherwise cast in their lot with us, and who find that time is too short for both series of meetings. Some have the mistaken idea that biology is too deep and uninteresting for any but the specialist, and that our proceedings may be learned but are dull. Buology 1s only as deep as the nature it studies, and that is of all depths, and it is interesting to every naturalist who loves any or all sides of nature; and, as for our methods here, they are in the hands of our members, and those of us who have been longest on the Council will rejoice the most at seeing more of our younger members playing a more active part in the affairs of the Society. But I believe a far more potent reason than those I have given is simply that we are not known. I believe that there are hundreds, possibly thousands, in these parts SOME PROBLEMS OF THE SEA. BS) of Lancashire and Cheshire who would be sufficiently interested in at least some of our meetings—no one need pretend to be equally interested in all—to receive intellectual pleasure and stimulus if they only knew of the existence and work. of our Society. The terms of membership ought to be made as easy as the Council can devise, the proceedings at our meetings ought to be made as instructive and interesting as Science knows how, and then every man and woman who studies, or wishes -to study, or cares about advancing the study of, any branch of Natural Science—including what is called ‘‘ Nature- Study ’—ought to join our ranks and take part in our work. It lies with our present members to enlarge our bounds and to draw others within the fold. I appeal with confidence to you all to bring your friends to the meetings, and, if they are interested, to propose them as members, and to make the Society and its work known in any way that presents itself. Finally, I appeal for more young members. All biologists are young in spirit. The study of nature keeps them young, or, if they have only taken to it late in life, it makes them young again. When I think of the young men I have known of mature age—such as the late Dr. David Robertson, “ the naturalist of Cumbrae,” who came dredging with some of us on the West Coast of Scotland in his 86th year, and was as keen and useful as the youngest and best of us—I am sorry for the prematurely aged persons of few years, but many cares, who have no interests beyond their business and, it may be, a football match or the golf links. A “hobby” is the saving of many both in their physical and their mental health, and no hobby is so conducive to health, sanity and happiness as devotion to some branch of Natural Science. The advantage of biology as a _ science for 4 . TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the amateur is that you can _ sub-divide it as much as you like, and still study your fraction in an intelligent manner. Years ago one of the amateur naturalists of Liverpool devoted his leisure to the special study of the common cockroach, but after some time he found his subject too large and had to restrict his attention with increased interest to one of the markings upon the head of that complex animal. That may be regarded as an extreme case, but, to take other examples, the study of Foraminifera, of Molluscan Shells, of Zoophytes and of Polyzoa, of Copepoda or of some group of Insects, is a subject large enough as a serious “hobby ” for any man or woman. I need hardly say that such an amateur naturalist may do very good work and make valued additions to science. It is one of the glories of British Marine Biology that so much has been discovered and so many of our best monographs written, not by professional men, but by serious amateurs—men who have devoted the leisure of busy lives to the study of some branch of the subject as a hobby. I should lke to see more young men and women come forward as members of this Society and become practical Naturalists. Those of us who are older and have had, so far, more experience of nature and methods will be only too thankful to help them at the beginning, then to work with them, and finally to learn from them. IT have just mentioned ‘“ methods,” and one of the first methods to learn is the method of collecting the organisms you wish to study; and that brings me to the second part of this address, in which I wish to lay before you for consideration some questions in connection with methods of collecting in Marine Biology which I have had occasion to think about of late years. SOME PROBLEMS OF THE SEA. 5 The methods of collecting you adopt will, - of course, depend upon your object in collecting. If you want large numbers of specimens you will adopt one method, and you will collect when, where and how you find you can get the greatest abundance. If, on the other hand, you want as many kinds as possible, you will adopt most varied methods, now one and now another, and you will collect in a very different manner in the different seasons and localities. But, so far, you will only get what may be called quali- tative results, and that is what most naturalists have been content with in the past. Edward Forbes, the pioneer of dredging in this country, Wyville Thomson, the leader and hero of the “Challenger” expedition, Alder and Hancock, Carpenter and Jeffreys, Hincks and the Bradys, the well-known authors of our most authoritative works on marine biology, have all collected in the manner I have indicated above and have recorded qualitative results only. They have told us, in their monographs and reports, about the various kinds of animals found, but have only given vague indications of the relative abundance, of the seasonal variations, of the topographical distribution and of the bionomics of their environment. ‘Is any other kind of result attainable by collecting methods? ‘That is one of the most important and funda- mental questions which the marine biologist of the present day has to consider. When the application of marine biological enquiries to the problems of the fishing industries came to be investigated it was realised that a quantitative knowledge of such organisms as constitute the food, the enemies and the fellow competitors of our marketable fishes was desirable if not essential. Of these matters we then were, and still are, very ignorant. Lord Onslow, our first Minister of Fisheries, in opening, a year 6 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. ago, these Laboratories in which we are now assembled, alluded to the absence of exact knowledge of the subject which he found on taking office as President of the Board of Agriculture and Fisheries. Of course, isolated facts of a quantitative nature had become known and were accumulating, but there was no organised body of quantitative data such as would suffice to guide a policy or lead to definite conclusions on many fishery questions. Asan unimportant example of such an isolated obser- vation we may take the fact that about twenty millions of the minute organism Ceratium tripos may be eaten in one day by the sardine on the French coast. No doubt every fact in science is of some value, and will one day find its place in the completed scheme of knowledge. But as a single observation unrelated to other facts this is of comparatively little value, except in so far as it suggests to us how important it might be to find out when, where and why the Ceratium becomes available as food for the sardine, where it comes from, and why it is sometimes absent. Many attempts have been made of recent years to answer such questions by obtaining quantitative information as to the distribution of organisms in the sea. The most noteworthy example of such work is that done by the German “plankton” naturalists, such as Hensen, Brandt, Lohmann and Apstein, at first under the well-known “ Kiel Commission,’ and latterly in connection with the International exploration of the North Sea, These investigators, and especially Professor Hensen, deserve the greatest credit, not only for the central idea of organising and employing such means as would give exact quantitative results, but also for the ingenuity with which they have devised and worked out the details of the necessary methods and instruments. They have invented deep-water tow-nets, the silk of which SOME PROBLEMS OF THE SEA. 7 is shaped in accordance with mathematical formule to ensure the most efficient proportions. They have calculated filtration co-efficients applicable to each kind of silk employed, in its various conditions. They have elaborated apparatus for filtering, measuring and analysing the results of the catch. They have made series of observations in fresh-water lakes and in some parts of the ocean, and from the samples so obtained they have drawn conclusions as to the population and the cyclical changes of matter in the sea of a very wide- reaching nature. Dr. J. Travis Jenkins, some five years ago, gave an account to this Society of the “ plankton ” work as carried out by the Germans in the North Sea and the Baltic, and on that occasion he said:——‘‘ It is to be hoped that the Irish Sea may be subsequently investigated in like manner. A comparison with the results already obtained from the North and Baltic Seas could not fail to be of interest and to yield important results.” (Trans. L.B.S., Vol. XV., p. 280.) For several years I have been trying to get such work carried out in connection with our local sea-fisheries investigations; but, although everyone concerned is sympathetic and helpful, it is difficult to get any new work, however important, undertaken on board a steamer that cannot, because of administrative duties, be wholly devoted to scientific investigation. A Hensen plankton net has now been obtained for the fisheries steamer, but is not yet being systematically used. It was partly because of this difficulty that I decided to charter a small steamer myself for a couple of’ months this summer and then made the series of trials of plankton nets at Port Hrin which I shall tell you about presently. But let me first give you some idea of the problems in the economics of the sea, which Hensen and his fellow- 8 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. workers undertake to solve by means of their system of plankton observation. From a series of 120 observations in the Eckenférde district of the West Baltic, Hensen concluded that from January to April, over an area of about 16 square miles, there are in all 370 eggs of cod and flat fish per square metre of surface. He also calculates that the fish caught in the same district would, if left in the sea, produce 110°6 eggs per square metre, and the relation between these two totals shows that the fishermen capture in that district about one-fourth of the fish population annually. It is obvious that the correct- ness of this conclusion depends entirely upon how far the 120 original observations were truly representative of the 16 square miles of sea fished. As the result of three series of 49, 50, and 59 catches respectively, made in the North Sea in 1895, Hensen and Apstein computed that the North Sea contained that season, in its surface waters, 157 billions of fish eggs. Here the quantity in the 547,623 million square metres of the North Sea has been estimated from 158 sample- catches, and from our knowledge of the average number of eggs produced annually by each kind of fish, it is stated that we can arrive at the actual number of mature food fishes of the North Sea upon such a small number of samples as 158—only one for each 3,465,968,354 square metres of surface. From certain samples obtained from the West Baltic it has been calculated that every square mile contains 80 to 100 billion Copepoda, and from the relative proportions of eggs, larve and adults it is deduced that for the 16 square miles of the fishery district the annual consumption of Copepoda must be 15,600 billions; and that con- sequently that district supports Copepod food sufficient for 534 million herring of average size, a colossal conclusion to base SOME PROBLEMS OF THE SEA. 9 Nothing in the economics of the sea could be more important than such conclusions if we could feel certain that they are correct, or even that they are reasonable approximations, for, of course, in dealing with such very large numbers it is not possible, and it is not necessary, to have absolute accuracy. These elaborate and highly ingenious methods of Hensen and his school, devised both to capture and to estimate the living contents of the sea, have naturally been subjected to a certain amount of criticism. This has appeared chiefly in Germany and in the United States, and a fair example is seen in Professor Kofoid’s paper “On Some Important Sources of Error in the Plankton Method ” (see “ Science ” for Dec. 3, 1897).* It has been pointed out by Kofoid and others that the net does not, as a matter of fact, filter the whole of a column of water through which it passes; a part of the water is pushed aside. There is for every net—-probably for every net on every occasion when it is used—a co-efficient by which the result must be multipled. It is difficult enough to determine this co-efficient (some number such-as 1°32, which has sometimes been used) when all the factors in the case are known, but even when it has been correctly determined for a special form of net and mesh of silk it must not be assumed that it will remain constant. On the contrary, it will vary with the rate at which the net is hauled and with any current tidal or other in the water; and, furthermore, there are two changes which take place in the mesh of the net that will affect it, viz., shrinkage with use and clogging with * See also his ‘‘ Plankton of the Illinois River’’ in Bull. Llin, State Lab. Nat. Hist., vi., Nov. 1903, where Kofoid explains why he relinquished the Hensen and Apstein nets for the pump-plankton method, 10 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. particles organic and otherwise. Kofoid finds that from shrinkage alone the area of the openings in a square centi- metre may decrease 90 per cent. A difficulty of quite another kind that has been pointed out by various critics is that small as the meshes of the silk are, many of the minuter organisms of the plankton pass through and are lost. Kofoid has determined the percentage of loss from this source for certain organisms, ¢.g., he finds that “of Codonella as many as 21 individuals may escape to one retained.” But these difficulties, serious as they may seem, and as they are regarded by some, may still be to a considerable extent overcome by taking precautions and by applying corrections to the result. They are trouble- some difficulties, but they are not, to my mind, fatal. They only make the work more difficult, more expensive, and more slow. They may still, after all corrections have been applied, allow of a fair approximation to a correct quantitative estimate of the organisms present in the particular sample of water through which the net has been pulled. But can we safely apply the results so obtained to any further purpose? This brings me to my main difficulty—a difficulty I have felt for many years, but which was forcibly brought before me in my observations at Port Erin during the present summer. It is a funda- mental assumption (principle I think it is sometimes called) in the Hensen method, that the organisms are distributed with such uniformity over wide areas of the sea that, after taking some samples per square metre, it is considered justifiable to multiply up by the number of square metres in a fishing district, or even in the wide extent of the Baltic or the North Sea. Here we have evidently a most fundamental point upon which the stability of the entire superstructure depends. If your SOME PROBLEMS OF THE SEA. tie samples are not sufficiently representative, if your observations are lable to be affected by any accidental factor which does not apply to the entire area, then your results may be so erroneous as to be useless or worse than useless, since they may lead to deceptive conclusions. Let us examine this assumed uniformity of the plankton. It is a: common experience of all naturalists who have tow-netted much on the surface of the sea, that many of the commonest organisms occur in swarms, and that neighbouring areas of water may differ very much in density of population and may also change greatly from day to day. Many such cases are recorded in the ltera- ture of biology, in the Reports of the “ Challenger ”’ expedition, and elsewhere, but I may add here a few observations of my own. On the West Coast of Scotland I have seen large Copepoda so abundant for a mile or two that they seemed from the deck of a yacht to be dancing in crowds in the water. On stopping the boat and taking a gathering with the net they were found to be Calanus fimmarchicus. In a few minutes we passed out of the swarm. Consequently, two sample gatherings taken a mile apart would, on this occasion, have given totally different results. On our L.M.B.C. expeditions in the Irish Sea we have on many occasions noticed and recorded the very irregular distribution of Anomalocera patersoni. On one occasion, in the North of Norway, I got in a short haul of the surface tow-net a phenomenal amount of the bright red northern form of Calanus finmarchicus—so much, in fact, that after filling various jars, some of which are still in our Museum, we cooked and ate the remainder. We took tow-nettings in various other places to the north and south, but never got another such haul. And this irregularity in distribution does not apply to 1s TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Copepoda alone. To take an example from the lower marine plants: —In the Red Sea and on various occasions in the Indian Ocean I have seen T'richodesmiwm erythraeum forming a most conspicuous red-brown or tawny vellow-brown scum on the surface of the sea for, it might be, a few hundred yards up to a mile in width, and several or even many miles in length, while the sea at each side of the patch was entirely free from the organism. Under these circumstances, and I believe them to be the most usual circumstances, a sample taken in the Trichodesmium area, or possibly two successive samples taken by a vessel running along the length of the tract, would give enormous numerical results, while if the samples had been taken a mile away the conclusions arrived at as to the prevalence and importance of the organism might have been very different. Noctiluca miliaris, again, is very local in its distribution. Occasionally, during recent years, I have taken it in abundance in late summer off the North Coast of Anglesey, while Mr. Chadwick, tow-netting at the same time at Port Erin, only 50 miles distant, across the same sea, has not been able to find a single specimen. Before turning to my observations at Port Erin this summer, let me direct attention to the results obtained by Dr. Herbert Fowler in his expedition in the North Atlantic in the summer of 1900—a cruise which has thrown much light upon the relations of oceanic plankton. Dr. Fowler’s results are very valuable in demonstrating the varied coniposition of the plankton from day to day in the open sea. His sixteen stations were so close together that the whole area investigated measured only 66 miles by 22, and his results for the Chaetognatha show that even at adjacent stations on successive days the numbers obtained were very different, one catch being SOME PROBLEMS OF THE SEA, 138 many times another, and the greatest about 30 times as much as the least. Now, if a vessel taking observations, say, 20 miles apart, were to have traversed this area and obtained only one of these gatherings, she might have gone off with a so-called sample which was ten or twenty times too great or too small to represent fairly the average, in either case giving an indication that was false and might lead to entirely erroneous conclusions. Similarly in the ease of Doliolum, Dr. Fowler found an enormous dis- proportion between the amounts of the catch on the different days, even at closely adjacent localities. It is obvious that if the number of Doliolum present in the area were calculated from one of his samples (such as No. 8) the result would be entirely different from that based upon other samples (such as Nos. 24 and 25). Cases of this kind could be multiphed, and have no doubt occurred in the experience of most naturalists whe have done much work at sea. And it was the knowledge of such cases that induced me this summer to devote the vacation almost wholly to making successive plankton hauls day after day in a limited area of the open sea off Port Erin, for the purpose of comparing days, nets, and depths with one another. I chartered a small steamer, which proved fairly well suited for the purpose, and cruised mainly between Port Krin and the Calf Island. Nearly 80 gatherings were taken in about 40 days, and I used in all five different nets, all made of fine miller’s silk. These were :— A Hensen closeable net of 200 meshes to the inch; A small Apstein net of 212 meshes to the inch; An open tow-net, weighted, 120 meshes to the inch; An open surface tow-net, 120 meshes to the inch, new; And an open surface tow-net, 120 meshes to the inch, one season old, 14 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. The Hensen closeable net (Petersen’s modifica- tion) and the weighted open net were lowered to about the same depth, but gave, when worked together for the same time, in most cases very different results. The two open surface nets (old and new) were worked side by side, and although they were of exactly the same size, and differed only in the age of the silk of which they were formed, the catch was in most cases very different. These differences were on some occasions obvious to the eye when the net was emptied on board ship; but all the gatherings, carefully preserved by Mr. Chadwick, have since been measured and worked over by Mr. Andrew Scott, who has kindly supplied me with his detailed lists. It is from these that I quote the following examples. | The gatherings varied in quantity from 0°5 to 40 c.cm., although all were as nearly as possible 15 minutes’ hauls. In some cases the plankton seemed to be fairly evenly distributed between surface and deeper waters, while on other days great differences existed, e.g., off the Calf Island, on August 10th, the surface net and the net towed at seven fathoms gave the same amount of material; while at the same spot, on August 13th, the surface net gave 8 c.cm. and the net at ten fathoms 32 c.cm., and the following day, at the same spot again, the surface net had only 3°5 c.cm. and the net at ten fathoms 40 c.cm. — Even in cases where the surface and deeper hauls were not very different in quantity, a marked difference in quality was sometimes visible to the eye at the time, and this has since been corroborated by Mr. Scott’s | examination, ¢.g., on August 31st, off the Stack of Calf, surface, 8 c.cm.; five fathoms, 13 c.cm.; ten fathoms, 14 cem. Mr. Scott remarks:—-‘‘ Larger number of SOME PROBLEMS OF THE SEA. 15 organisms at bottom, but variety not so great; Acartia and Ozthona common all through; Anomalocera and Centropages and Crab Zoea at surface only; Calanus, Paracalanus and Pseudocalanus more plentiful in the deeper water than at surface.’ Again, on August 24th, three miles west of Bradda Head, Mr. Scott remarks :— “Tt is evident from the two (surface) collections that there was a difference in the organisms even in a very small space. A marked difference is discernible between the surface and ten fathoms.” Throughout these gatherings Ozthona seems to be mainly a surface Copepod and T’emora mainly a deeper form; Anomalocera is chiefly on the surface, and Calanus more abundant in the deeper nets. Sagitta is more abundant below than at the top. Although in many cases the deeper gathering was larger than the surface one with the same net, this was not invariably the case as the following examples show :— Aug. 24th.—Surface, 8 c.cm.; 5 faths., 19 c.cm. Aug. 27th.—Surface, 11 c.cm.; 5 faths., 8°5 c.cm.; 10 faths., 5 c.cm. Aug. 28th.—Surface, 13 c.cm.; 10 faths., 9 c.cm. Sept. 6th.—Surface, 6 c.em.; 10 faths., 0°5 c.cm. Sept. 7th.—Surface, 16 c.cm.; 5 faths., 6 c.cm.; 10 faths., 3 c.cm. 62 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Forward ... Holt, Mrs., Sudley, Mossley Hill ... Holt, P. H., Croxteth-gate, Sefton-park ... Holt, R. D., 54, Ullet-road, Liverpool Hoyle, Dr. W. E., Museum, Owens College Isle of Man Natural History Society James, C. H., Holzendorff, Grange View, edna Jarmay, Gane Hartford, Cheshire Jones, Charles W., J.P., Allerton Beeches Lea, Rev. T. Simcox, Leek Ne ee sae Lonsdale Leicester, Alfred, 30, Bienes street, iene Lewis, Dr. W. B., W. Riding Asylum, Wakefield... Manchester Microscopical Society... Meade-King, R. R., 4, Oldhall-street Monks, F. W., Warrington... Muspratt, EH. K., Seaforth Hall O’Connell, Dr. J. H., Dunloe, Heathfield Boni Liverpool Okell ake BAL SEAS. Stil, Deamas L of Man Petrie, Sir Shel Devonshire-road Pilkington, J. A., Bank House, Maghull ... Quayle, Alfred, 7, Scarisbrick New-road, Southport Rae, Edward, Courthill, Birkenhead Rathbone, Mrs. Theo., Backwood, Neston.. Rathbone, Miss me Northumberland eras London : Rathbone, Mrs., ae ae Kneash BS Roberts, Mrs. Isaac, Thomery, 8. et M., nccueee Robinson, Miss M. E., Holmfield, Aigburth, L’ a Simpson, J. Hope, Aigburth-drive. . Smith, A. T., 43, Castle-street bee Sorby, Dr. H.C., F.R.S., Broomfield, Sheflield att Tate, Sir W. H., Woolton, Liverpool La Thompson & Capper, 4, Lord-street, Liverpool ... Forward £82 ude 42 17 6 eee 0 Lo ANG) 2 0-6 1. och Seu gee Pes 0) L ee) ee et 1. O20 mee ers |) 1. a) Ls LOG 1 ae) 0 1086 2 2.70 5 0 0 Ree et) fee WO) 1 te0 0 10-46 1 4d 36 Ae aoe) 1 ae > a NO oe Faroe BPDorRrFOrRF DN # st j=) rnlocooacococeo t CO bo 4 Cr MARINE BIOLOGICAL STATION AT PORT ERIN. 63 ise “de Forward... Ss cmt ALG MENS Thornely, The Misses, Nunclose, Grassendale, Liverpool Timmis, T. Sutton, Gleley, een Toll, J. M., 49, Newsham Drive, Liverpool Walker, Alfred O., Uleombe Place, Maidstone ... Walker, Horace, South Lodge, ae ) Walker, W. H. & Co., Douglas Watson, A. T., Tapton-crescent, Sheffield.. Whitley, H., Clovelly, Sefton Park, liaet pool Weiss, Prof. F. E., Owens College, Manchester ... Wiglesworth, Dr., Rainhill.. Wragg, Sir W., D. 6. Jon, IRores St. Mary, Isle of Man Maret C. H., 9, Agee street, Liverpool ... 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FRCS Pte ATOUOTIEIS pue suyung ‘ a 0 iZ SGee hee “ posdateoed suolyeuogd pue suoiydrazosqng Aq OL 9L Z@ GO6T “ISTE Joquieoecy ‘teanseery, onp souRTeg og, S och ae ‘9061 ees: “906T n a Fe "1D ‘UdUASVaAT, “NOH ‘NOSHWOHL NIMC HLIM LNnOODY NT IVG HH LLINAOO ADOTOIC ANIYUYAW "IOOdUHATT AHL 64 65 L:M.B.Cc. MEMOIRS No. XIV. BY LIGIA. C. GORDON HEWITT, B.Sc. Demonstrator in Zoology, University of Manchester. CONTENTS. PAGE Introduction : , 2.66 Vascular System . Biology - ; : + (ON Nervous System . External Characters . ) (38) Sensory Organs Appendages . 5 5 eee Excretory System fj Body Wall, Muscular System Reproductive Organs . and Body Cavity . Ye Development Digestive System - > BHT Literature PAGE 82 87 88 90 92 93 96 66 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. INTRODUCTION. The Isopod Ligza oceanica (Linn.) has been selected as the type for this Memoir on account of its comparatively large size, being the largest British Isopod, and also because it is one of the most interesting of the group, being mid-way between the aquatic and terrestrial forms. The Isopoda, with the Amphipoda, form the sub-order Arthrostraca, and are characterised by being Malacostraca with seven distinct thoracic segments, each bearing a pair of limbs (except the Gnathiidae) and possessing sessile eyes; on account of the last character, they are usually classed together in the sub-order Edriophthalmia. The Isopoda possess a dorsoventrally depressed body. The thoracic limbs do not bear branchial appendages, as in the Amphipoda, but respiration is carried on by means of the abdominal appendages, which are modified for that purpose, the modification varying in the different tribes. The terrestrial Isopods, the Oniscoidea, are the only members of the group which exhibit such a uniformity in the character of the thoracic appendages as to justify the name. The following classification of the Isopoda is that given by Sars (1896), each tribe being defined by three characters—those of the first pair of legs, the uropoda, and the pleopoda or abdominal appendages : — I. First pair of legs cheliform; Uropoda terminal ; Pleopoda, when distinctly developed, exclu- sively natatory - - - 1. Cheliferae. II. First pair of legs not cheliform. (1) Uropoda lateral. (i) Pleopoda for the most part nata- tory, forming a caudal fan with the terminal segment of the metasome - 2. Flabelliferae. Liew. 67 (11) Pleopoda to a great extent branchial; the Uropoda valve like, inflexed, arching over the Pleopoda - - - - 3. Valviferae. (2) Uropoda terminal. (i) Pleopoda_ exclusively branchial, generally covered by a thin oper- cular plate (the modified Ist pair) - 4. Asellota. (11) Pleopoda for air breathing - 5. Oniscordea. (111) Pleopoda when present, exclusively bran- chial in the adult animal and not covered by an operculum . - - 6. Epicarida. Inga oceanica belongs to the tribe Oniscoidea, which are characterised by being terrestrial. This tribe includes all the so-called “ wood-lice.” Their abdominal append- ages are fitted for air breathing, but in Ligia there is a very near approach to branchial respiration, as moisture is necessary. ‘The body is oval in shape, and the seven pairs of thoracic appendages are similar in character. Ligia oceanca was first described in 1767 by Linnaeus as Oniscus oceanicus. Later, in 1798, the genus Ligia was created by Fabricius to include the Oniseus oceanicus of Linnaeus. BIOLOGY. Ligia oceanica (P1. I.) has a wide distribution, and is recorded from the coasts of the British Isles, Faroe Islands, Norway, Denmark, Germany, Belgium, France, Spain, Morocco and America. At Plymouth* I have found Ligia most numerous, and of the maximum size, on Drake’s Island. At Port Erin they occur in the cliff near the old biological station. * I wish to express my thanks to the Council of the Marine Biological Association of Great Britain for the use of a table at the Plymouth Laboratory, during the Easter vacation, 1906. Other material for this memoir was obtained at the Marine Biological Station, Port Erin, during the Easter vacations, 1903-4, 68 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. They are terrestrial, but require a certain amount of moisture. On the other hand, they are unable to withstand prolonged immersion in sea-water, and still less in fresh water. They are found just above high-water mark in a zone of varying width. The height of their habitat above high-water mark seems to depend on the nature of their surroundings, which is varied. The greatest number are found in deep narrow crevices in the rocks immediately above high water. Here they can be found in large numbers packed closely together. They also abound in crevices on the side of a quay, hence their name, ‘ quay-louse’ or ‘quay-lowders.’ They are also known as ‘ sea-carpenters,’ ‘carpenter’ being a local name of the wood-louse. They can be found between the wooden piles of a pier or under the loose stones and rubbish cast up by the tide, which have accumulated in small dark holes. The highest level is attained by those specimens which live in the loose clay and shale forming the cliffs on many parts of our coast, but the specimens living in these conditions do not attain the size of those living lower down in the rock crevices, and are generally of a darker colour. In St. Kilda, I have found them in the crevices of the boulders on the top of a hill over 450 feet above sea-level. This high altitude may be explained by the fact that the sea spray often reaches that height. It is extremely improbable, however, that the animals go down to sea level to feed. Contrary to the usual rule, the majority of individuals found at this high level were females. I found large numbers of young individuals under rocks between tide marks, and none at the high level, these females probably go down to the sea level to liberate the young from their brood-pouches. The colour varies from a dark greyish green to a LIGIA. 69 light dirty brown. In young specimens two light-coloured patches occur on the median line of the dorsal side. The colouration has generally a mottled appearance, the dark portions being due to presence of closely packed chro- matophores. In injected specimens a close connection is observed between the terminations of the fine capillaries and the chromatophores. In moulting, the cuticle of the posterior half of the body is shed first, and a short time elapses before the anterior half is shed, so that individuals are often found with the posterior half of the body lighter in colour than the anterior half. Their food consists chiefly of decaying animal and vegetable substances, and from a study of the contents of their guts, the latter appear to form a large proportion of their diet. In captivity they prefer the weaker members of their own species, but there is not much evidence that this is a natural habit. They are able to run with great rapidity, coming out from their dark retreats after sunset to feed, at which time they may be caught with the aid of a lantern. The best instrument for capturing them during the day is a fairly long wire, having the last half-inch bent at right angles; by means of this they can be extracted from their narrow crevices. EXTERNAL CHARACTERS. The body is oval in shape, broadest across the fourth thoracic segment, and gradually decreasing in size towards the posterior end. It is almost twice as long as it is broad. The males are larger than the females, the reverse being usually the case in Arthropods. They may attain a length of 32-54 mm., the width of the thorax reaching 18 mm. ‘The females are more regularly oval in shape 70 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. and may reach a size of 26 mm., their extreme width being 11 mm. The dorsal face of the body is moderately convex, and its surface is granulated. The body can be con- veniently divided into four regions—1l, the head segment or cephalon; 2, the mesosome or thorax, consisting of seven segments; 3, the metasome or abdomen, consisting of five distinct abdominal segments, together with a terminal segment, which is, 4, the telson. The cephalon is sunk into a depression formed by the forward growth of the epimeral portions of the first thoracic segment. It is evenly convex in front; the posterior border is depressed, the edge being marked by a ridge. The dorsal surface is slightly curved trans- versely. A pair of large compound sessile eyes are situated laterally, each having a slight reniform appear- ance from a dorsal view. On the anterior face, which is almost vertical, the minute pair of first antennae are situated, one on each side the median line. ‘To the outside of these are the large and robust second antennae. When moving, the animal holds the large antennae in a forward position, and constantly tests the nature of the surface over which it is proceeding with the very sensitive flagella, appearing to trust for guidance more by this means than by means of its sight. When at rest, they are folded back along the sides of the mesosome. On the ventral side of the head the mouth-parts form a prominent projection. The mouth is bounded in front by a large transversely-hinged labrum. ‘The sides are _ composed of the powerful mandibles and two pairs of maxillae. The posterior border is formed by the two maxillipedes, which are imperfectly fused together, forming an apparent lower lp; there is, however, internal to these, a lingua-like bilobed chitinous plate, deeply incised in the middle and having a small median plate; LIGIA. al this forms a true posterior lip. The maxillary excretory organ opens at the base of the second maxilla. The seven segments of the thorax form the greater part of the animal’s body. ‘They are convex on their anterior margins and concave behind. The lateral portions form large epimeral plates, obtusely acuminate, and directed - backwards. The segments slightly overlap, and the uniting membrane, which is not impregnated with calcareous salts, sinks into the hypodermal tissues. On the ventral sides, where the epimera join the body, the walking legs or pereiopods arise. The first three pairs of pereiopods are approximately the same size, the last four pairs gradually increase in size. The ventral wall of the thorax is thin and transparent, and strengthened by slightly curved transverse bars. On the ventral side of the thorax of the female, the brood-pouch full of ova is very conspicuous in the breeding season. It is formed by lamellae which arise inside the origin of the five anterior pairs of thoracic appendages and grow ventrally, overlapping the adjacent lamellae distally and laterally. The paired female genital apertures are situated on the inside of the fifth pair of pereiopods. The male genital products are ejected through a pair of styliform appendages on the posterior border of the last thoracic segment, immediately in front of the branchiae. The metasome or abdomen consists of five segments and the telson, and is about a third of the entire length of the animal. The two anterior segments are narrow, and do not reach the margins, but are lodged in the concave posterior border of the seventh thoracic segment. The three posterior segments have their lateral margins produced into tooth-like backwardly projecting processes. Five pairs of uropoda, which are of the nature of branchiae, are borne on the ventral side of the abdomen. 72 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Each of these consists of an outer ‘opercular’ lobe and an inner lobe. In the male the inner margins of the outer lobes of the first pair may, or may not, be produced into short spinous processes; the inner margins of the second pair are produced into two long slender styles for copulatory purposes. The terminal segment or telson 1s composed of the last two segments of the metasome, which are fused to form a rather broad terminal segment. ‘The posterior edge is evenly rounded; the lateral portions are acuminate and subtend a sinus in which the terminal pair of uropoda arise. Each of the terminal uropoda consists of a fairly stout basal portion, from which the styliform appendages arise. The anus is a longitudinal slit on the ventral side of the terminal segment. The external apertures are—the mouth, the openings of the maxillary excretory organs on the protopodites of the second maxillae, the openings of the oviducts at the base of the fifth pair of pereiopods, or of the vasa deferentia at the posterior border of the ventral side of the seventh thoracic segment, and the anus. APPENDAGES. The first pair of antennae (PI. II., Fig. 1) may be truly called antennules, as they are extremely small, measuring a little over 1 mm. in length. They are situated internal to, and at the base of, the second antennae. They are triarticulate, the terminal jomt being quite rudimentary and bearing two terminal groups of small setae. The second pair of antennae (PI. II., Fig. 2) are long, attaining a length of 25 mm. in the male and 14 mm. in the female; when folded back they extend to the posterior border of the fourth thoracic segment. The protopodite is composed of five joints, the fourth and fifth being the LIGIA. 1(cs) largest; the fifth joint equals in length the proximal five joints of the flagellum. The flagellum may have as many as 13 or 14 joints, which are setose, the setae being of two SIZES. The mandibles (PI. II., figs. 3, 4) are very powerful and consist of a single protopodite. The point of attachment is D shaped, the curve being internal. From the anterior end of the external border, a powerful tooth-bearing process curves inwards, forming a quadrant-shaped anterior face. The curve of the quadrant is external; the lower side is partially attached and the vertical side bears the mandibular processes. Internally, on this vertical side, there are—a stout molar process, the flat extremity of which is covered with minute closely-set teeth ; a small palpiform structure bearing setose bristles, and two stout mandibular teeth separated by a sinus, each being sub-divided into three smaller teeth. The ventral edge of the mandible is produced into a rounded keel, which gradually diminishes in depth towards the posterior edge. The first pair of maxillae (Pl. II., fig. 5). Hach maxilla is composed of two lobes. The outer lobe is calcified and much stronger than the inner, which is more flexible. The inner lobe is terminated by three deflexed setose bristles; the outer lobe has a terminal group of short thick spines. The second pair of maxillae (PI. II., fig. 6) are much modified, being thin and flexible. Hach consists of a long protopodite, terminated by an oblique setose joint having internally at its base two setose bristles. The maxillary excretory organ opens at the base of the protopodite. The maxillipedes (Pl. II., fig. 7) are closely approxi- mated on their inner sides and joined at the base, so that 74 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. they form an outer lower lip. Each consists of an inner rectangular plate spinose at its anterior margin, and an outer five-jointed palp. The joints of the palp are spinose, each of the four distal joints having on its inner side a setose pad. At the base there is a small lamella. The pereiopods (Pl. II., figs. 8, 9) or ambulatory appendages. Hach pereiopod consists of a basal protopodite and an endopodite, which is composed of five spinose joints (ischiopodite, meropodite, carpopodite, propodite and dactylopodite). In the posterior pairs of pereiopods, the carpopodite and propodite are long in comparison with the other joints. The dactylopodite bears two strong re- curved claws. In the female each of the anterior five pairs of pereiopods (Pl. II., fig. 12) subtends a thin foliaceous lamella which curves downwards and inwards, overlapping the opposite and adjacent lamellae, and thus they form a brood pouch in which the eggs are carried. These lamellae are not out-growths of the limbs, but of the sterna. Abdominal appendages. ‘here are five pairs of abdominal appendages or pleopoda, and a terminal pair of uropoda. Hach pleopod (Pl. II., figs. 11, 13) consists of a pear-shaped superior lobe covering a small inferior lamella. In the terrestrial isopods, the outer lobe is termed opercular and the inner branchial. In Jzgza both are branchial, as will be shown later. At the base of the outer edge of the superior lobe, there is a small lamella. The edge of the superior lobe is fringed with a border of setose bristles. The second pair of pleopods are modified in the male by having a two- jointed style arising at the base of the inner margin of the superior lobe (Pl. II., fig. 10). The style is long and grooved, and reaches to the fourth pleopod; its distal extremity is slightly swollen and finely pointed. It is LIGIA. 75 for copulatory purposes. The superior lobe of the first pair of pleopods also may be modified slightly for copula- tory purposes. The third, fourth, and fifth pairs of pleopods are very similar in character, the third pair being the largest. The uropoda (P1.II., fig. 14) are situated at the posterior edge of the sixth abdominal segment or telson, the pleural regions of which are produced posteriorly, thus forming a small sinus in which the uropods can bend laterally. Fach consists of a stout basal joint which is widest in the middle and truncated distally. The middle region is thick, narrowing off sharply to the outer edge, and slightly to the inner edge, which is adjacent to that of its fellow. Distally, two setose styli- form processes arise. These are about twice the length of the basal portion. During life they are carried in a diverged position, being separated vertically by a wide angle. The inner style has a well-developed terminal spine which is trailed over the ground, and is probably of a sensory nature, as it has similar nervous connections to the sensory bristles of the antennae. Bopy Wai, Muscunar System anp Bopy Cavity. The body wall consists of three layers, the outer cuticular layer, the hypodermis and the connective tissue. The cuticular layer is composed of a thin cuticula resting on a thicker layer of chitin, in which two distinct layers can generally be observed (PI. IV., fig. 3). The chitin is impregnated with salts of calcium, which cause it to have a fairly resistant and brittle texture. Between the segments the chitinous layer is thin. In the middle region of the dorsal side the intersegmental membrane does not dip deeply into the tissues, as it does at the sides. The cuticula bears spines and setae in many regions of the 76 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. body. The hypodermal layer is composed of a single layer of cubical cells. Underneath the hypodermis the chromatophores are found. The rest of the body wall is made up of connective tissue, in which groups of large adipose tissue cells occur. These last cells also occur in large numbers on the walls of the alimentary canal, and dorsal to the heart. (PI. II., fig. 16, ad. tvs.) The body cavity (6.c.) is a haemocoel, the alimentary canal and other organs being in contact with the blood. A horizontal septum (sep.) divides the body cavity into a small dorsal pericardial cavity enclosing the heart, and a large sinus enclosing the other organs. The muscular system, excluding the muscles of the wall of the gut, heart, &c., consists of three sets of muscles —1, those in connection with the gastric mill; 2, the muscles moving the segments of the body; 3, the muscles moving the appendages. The muscles are composed of striated muscle fibres. The muscles controlling the gastric mill occupy almost the whole of the cavity of the cephalon and are very conspicuous on opening this. They are attached to the dorsal side of the cephalon, and most of them are inserted into the large lateral cardiac teeth. The muscles moving the segments of the body are also segmented, but the muscle segments alternate with the body segments. On each side of the dorsal Jine there is a series of longitudinal muscles (d.d.m.). The anterior end of each bundle of muscle fibres of this series is inserted immediately behind the anterior end of one segment, and the posterior end is inserted at the anterior border of the succeeding segment. In the lateral regions, where the cuticle dips into the body, a number of oblique muscle bands, which form a series of muscles on each side, have their posterior ends attached to the anterior wall of the cuticular TAnGoWAe (i invagination, and their anterior ends attached to the hypodermis of the middle of the preceding segment. In the lateral, and also the epimeral regions, the body cavity is almost entirely filled up with the muscles moving the appendages; these muscles are attached to the dorsal side of the animal in these regions (Jev.m.). The longitudinal muscles of the ventral side (v./.m.) have their attachments similar to those of the dorsal side. The joints of the thoracic appendages, like the appendages themselves, are provided with extensor and flexor muscles. The mandibles are provided with a powerful set of muscles, attached to the dorsal side. The proximal ends of the remaining mouth appendages have thickened skeletal rods, forming an internal framework, to which the muscles moving them are attached. Tur DIGESTIVE SYSTEM. The digestive system consists of the alimentary canal and its glands—the salivary glands, and the hepato- pancreas or digestive gland. The alimentary canal can be divided into four parts— the oesophagus, the stomach, mid-gut and rectum. The oesophagus (PI. II., fig. 15 oes.) opens by a slit-like aperture surrounded by the mouth appendages. Its course is almost vertical, and it opens into the anterior end of the stomach on the ventral side. The oesophagus receives the secretions of the salivary glands. The stomach forms an efficient mill for triturating the miscellaneous substances upon which the animal feeds. It lies in the cephalic and first thoracic segments. The wall of the stomach, which is composed of columnar cells, is lined with chitin, and is folded in a complicated manner; thus a number of chitinous lamellae are formed, 78 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. which project into the cavity of the stomach. The dorsal wall of the stomach is almost flat, and is continuous posteriorly with the mid-gut. The anterior end of the stomach is slightly oblique, and when seen from the upper surface is semi-circular. The plates and “teeth” which form the gastric mill are arranged in the followimg manner. On each of the lateral margins of the anterior end of the stomach a bilobed ampulliform triturating ‘ tooth’ (Fig. 15, /.c.t.) arises, and meets its fellow of the opposite side above the opening of the oesophagus. These lateral cardiac teeth are the chief masticatory agents of the gastric mill. Between these, on the anterior wall of the stomach, three teeth fill up the space, a small median anterior tooth (m.a.t.) situated between two antero-lateral teeth (a./.t.). Posteriorly, the closure of the entrance to the stomach is effected by a ventral transverse setiferous ridge, the ventral cardiac tooth (v.c.t.). In the preceding description, the word ‘tooth’ has been used to designate a chitinous protuberance of the wall of the stomach, which is covered with short, closely-set, re-curved setae. On the ventral side of the stomach, in the middle region, three tooth- shaped processes arise, their apices directed backwards; they are the median, ventral and ventro-lateral teeth (v.l.t.). On each side of the cardiac region of the stomach, a narrow lamella, the lateral cardiac lamella (/.c.l.) runs in an oblique direction from the antero-dorsal region to the ventral side, and terminates near the ventro-lateral tooth. In the pyloric region of the stomach, a deep invagination of the dorsal surface forms a broad dorsal lamella (d./.), which extends across the dorsal side and half-way down the lateral sides. Between the lateral portions of the dorsal lamella and the wall of the stomach, two large lamellae (v./.p.l.) have their lateral limits; these IG bAG 79 are the ventro-lateral pyloric lamellae. They arise on the ventral side immediately behind the ventro-lateral teeth. Their ventral edges almost meet along their whole length ; their lateral edges extend in an oblique direction from behind the dorsal lamella to the ventral side at the anterior end of the mid-gut, where each ventro-lateral lamella terminates in a fine point. The mid-gut (Pl. IT., fig. 16 md.g.) extends in a straight line from the posterior end of the stomach to the rectum in the posterior region of the abdomen. It is of uniform width throughout, except at the posterior end, where it narrows considerably, and is surrounded by a sphincter muscle. Three regions can be roughly made out, the arrangement of the epithelial cells of the gut being the means of demarcation. The wall is composed of three layers, an outer muscular layer, a median basement membrane, and internally the epithelium, which is covered by a chitinous intima. This intima is perforated and is shed when the animal moults. The muscular layer is composed of two sets of muscles, an outer longitudinal and an inner circular layer, but this only applies strictly to the anterior end of the mid-gut; further back the muscle fibres become separated by the bulging out of the epithelial cells. The epithelial cells of the gut are very large and contain correspondingly large nuclei. They form a syncytium, as they do not possess complete cell walls, but are separated by inter-cellular fibres, extending from the basement membrane to the intima, and probably of cytoplasmic origin. The arrangement of the epithelial cells varies in different regions of the mid-gut. In the anterior region, which is almost half the entire length of the mid-gut, the cells are irregularly arranged. On the lateral sides they extend in longitudinal rows; the two median ventral rows of cells extend from the anterior end 80 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. of the mid-gut to the posterior end. On the dorsal side of the anterior region, in the median line, a typhlosole (t.y.) is formed by the floor of a groove being re-invaginated ; posteriorly, the sides of the groove widen out into an elongate spoon-shaped structure. The function of the typhlosole is probably not, as is usual, to assist in the absorption of food, but to provide a channel along which the secretion of the hepatopancreas is able to flow to the middle region of the intestine. In the middle region of the mid- gut the epithelial cells exhibit a very regular arrangement. They are arranged in double rows, which run out in an oblique direction from the median line. ‘The rows of cells project into the body cavity, so that grooves are formed between the double rows. In these grooves the muscle fibres are lodged, underneath the blood-vessels from the intestinal arteries. The posterior region is marked by the presence of the sphincter muscle, which separates the mid- gut from the rectum. In the sphinctal region the faecal pellets are formed. The rectum is a short uniform tube opening by the longitudinal sht-hke anus. The salivary glands. ‘There are two pairs of salivary glands situated in the cephalon, on each side of, and opening into, the oesophagus. Hach is made up of a large number of rosette-like masses of gland cells, which are very similar to the mucous glands described by Allen (1892) in Palaemonetes. In section, they have the appearance shown in the figure (Pl. II., fig. 17). Each acinus is made up of a number of concentric cells, in which two regions can be recognised—a peripheral cytoplasmic region containing the nucleus, and a central glandular region. Each of the cells has at its internal apex an intracellular duct (2c.d.), which opens into a duct common to the mass of cells (¢.d.). This duct is probably LIGIA. 81 formed by a single cell, the nucleus of which can be seen near the centre of the gland (n.c.d.). The hepatopancreas. ‘This is also known as the liver, and the digestive gland; the last name describes its true function. In Lzgza it consists of three pairs of tubules, which extend from the pyloric region of the stomach to the posterior end of the abdomen, where they gradually taper off, and are generally doubled back for a short distance. The three pairs are situated in relation to the intestine, dorso-lateral, ventro-lateral and ventral (Pl. IL., fig. 16, v. hep., vl. hep.). The muscles of the walls of the distal two-thirds of the tubules are so arranged, that a spiral appearance is produced. The spiral arrangement of the muscles no doubt aids their peristaltic con- tractions. The tubules of each side open into the pyloric region of the stomach by a single aperture, behind and below the ventro-lateral teeth. The two ventrally placed tubules of each side fuse and then open into the stomach. Anterior to the opening the dorso-lateral tubules curve ventralwards, and fuse with the anterior end of the ventro-lateral tubules. A small tube is given off from the front of the common hepatopan- creatic duct, which runs forward for a short distance and ends blindly. The epithelial cells of the hepatopancreas are of two kinds—large secreting cells containing large nuclei, and smaller cells which may be either young secreting cells, or cells of an excretory nature. The physiology of the digestive system of terrestrial Isopods has been studied by Murlin (1902). He finds that the secretion of the hepatopancreas, which may be liberated by the dissolution of the cell, fragmentation of the cell, or evacuation from the cell, contains ferments, which are able to act upon proteids, carbohydrates and fats. F 82 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. VASCULAR SYSTEM. Delage (1881) has described the vascular system of Ligia oceanica in his Memoir on the circulation of the Kdriophthalmia, and, except in a few details, my results confirm his account. The heart (Pl. IIL, fig. 1, At) is a fairly wide tubular structure, extending from the fifth abdominal segment to the anterior end of the fourth thoracic segment. This posterior position of the heart is correlated with a posterior position of the organs of respiration. Its walls are muscular, and are perforated by two ostia (ost.), which are oblique slit-like orifices provided with muscles and two small inwardly projecting flaps. They are situated in the anterior and posterior regions on the right and left sides respectively. The pericardium (PI. I1., fig. 16, p.c.) extends from the anterior end of the heart to beyond the posterior end. Tt receives the efferent vessels from the branchiae, and is continuous with the venous lacunae in the anterior regions of the body. It is separated from the body cavity by a horizontal septum upon which the heart rests. The heart is continued anteriorly as the median aorta. On each side four arterial thoracic trunks arise. The first pair may be termed the lateral arteries; the remaining three pairs are the fifth, sixth and seventh thoracic arteries, and they arise in the anterior half of the heart. The median aorta (Pl. II1., fig. 1, med. ao.) runs forward along the dorsal wall of the gut to the cephalic region. In the anterior region of the second thoracic segment two arteries arise from the dorsal side, and run a_ sinuous course in the hypodermal tissues towards the epimera. In the first. thoracic segment a pair of large arteries arise laterally ee LIGIA. 83 and run outwards at right angles. Hach gives off a large branch which supplies the walls of the stomach, a branch running to the hepatic tubules, a few small arteries to the soft parts, and, after giving off another branch which runs into the epimeron (ep. art.), it unites with an artery (1) which is the anterior prolongation of the lateral artery. Immediately on entering the cephalic segment, a small median unpaired artery arises on the dorsal side, and bifureating, runs in the hypodermis. In front of this the aorta gives off a pair of ophthalmic arteries (op. a.) which run outwards to the eyes, giving off many small branches to the soft parts. The aorta now bends down in front of the stomach, where it dilates somewhat, the dilation lying in a cavity on the anterior face of the stomach. This dilation serves as a kind of cephalic ‘heart,’ as it has on each side muscles connected with a pair of chitinous rods from the anterior face of the stomach. These muscles will aid in the contraction and dilation of the cephalic ‘heart,’ and so help to pump the blood into the rest of the vessels of the median dorsal aorta; the blood, on account of the posterior position of the heart, would not be driven into these vessels so effectively, if it were not assisted by the action of the cephalic heart.* At the point where the aorta bends, it gives off dorsally a small median artery, and lower down two median unpaired arteries, each of which bifurcates, the superior one supplying the posterior side of the cerebral ganglion (cer. g.), and the inferior artery the anterior side of the ganglion. The aorta then bifurcates. Hach branch, besides giving off numerous small arteries, which can be better understood by reference to the figure (Pl. III., fig. 2), gives off a large antennary artery (ant.art.), and is then continued as the facial * Contractile vascular sacs occur in the heads of certain insects. Pawlowa (1895) has described them in the heads of certain Orthoptera, and, according to Selvatico, they occur in certain Lepidoptera. 84. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. artery (fac. art.), which supplies the mandibles and the lateral regions of the face. Neither the injections nor the serial sections showed any oesophageal ring of the nature described by Delage. Several small arteries are given off from the posterior border of the antenno-facial arteries which supply the oesophagus (oes. art.) and neighbouring soft parts, as will be seen from the figure. The fact that in many cases these small arteries dilate to an exaggerated extent when injected, may account for the mistake. The lateral arteries (Pl. III., fig. 1, dat. art.) run forward and outward from the anterior end of the heart, and in the first thoracic segment each anasto- moses with the transverse artery from the dorsal aorta. On the external side of each lateral artery, four thoracic arteries arise (i., 11., i11., 1IV.), supplying the first, second, third and fourth thoracic segments. On the internal side of the thoracic artery a number of branches are given off which ramify on the walls of the gut (ent. art.) and hepatic tubules (hep. art.). Close to the origin of the fourth thoracic artery a large branch (gen. art.) is given off, which supplies the terminal portion of the vas deferens. A number of arteries arise from the dorsal side of each lateral artery, and ramify in the hypodermal tissues. The thoracic arteries (i., il., ill., 1V., V., Vi., Vil.).—The course of each of the thoracic arteries, with the exception of the sixth and seventh, is somewhat the same. Each runs directly outwards, and, when dorsal to the hepatic tubules, gives off a ventral branch which supplies these. — Following the curvature of the dorsal surface the artery curves ventrally; a small artery arises which runs into the dorsal longitudinal muscles. When it reaches the insertion of the limb it bifurcates, the inner branch runs inwards and supphes the ventral surface, the outer branch EGA) 85 soon bifurcates again, the dorsal branch supplying the epimeral (ep. art.) region, and the ventral branch is the crural artery supplying the leg (er.art.).. The inner branches of the first thoracic artery supplying the ventral surface of the first thoracic segment unite in the mid-ventral line at the base of the maxilli- pedes, forming a median artery (Pl. III., fig. 2) which runs forwards and gives off paired arteries to the maxillipedes (map.), second (mz") and first maxillae (ma’), and terminates in the lingua-like lower lip. The sixth thoracic artery soon after its origin gives off a branch which runs ventrally, and unites with its fellow of the opposite side in the mid-ventral line of the intestine; from the point of junction a median artery runs forwards and backwards, forming a sub-intestinal artery. From the sides of the sub-intestinal artery paired transverse branches arise in a very regular manner, and run on the walls of the intestine in the oblique grooves which have been described above. The seventh thoracic artery, after running obliquely backwards for a short distance, gives off an artery which bifurcates and supplies the lateral regions of the intestine. It soon gives off from its posterior side a large artery, the abdominal artery which runs posteriorly; the rest of its course is similar to that of the other thoracic arteries. The abdominal artery (PI. III., fig. 1, ab. art.) of each side runs in an undulating manner, midway between the lateral margins and the median line ; from it arise small arteries supplying the intestine, muscles and other tissues. In the third abdominal segment it gives off a ventral branch which supplies the three anterior branchiae and the body-wall. The fourth and fifth pairs of abdominal appendages are supplied by an artery which arises from the abdominal 86 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. artery in the fourth abdominal segment. In the last segment an artery is given off internally to the intestine, on the ventral side of which it anastomoses with its fellow and the sub-intestinal artery. The abdominal artery finally terminates in the uropoda. The venous system is lacunar. A large thoracic sinus runs into the abdominal sternal sinus, from which five afferent branchial vessels arise; each of these bifurcates at the base of the branchial appendages, supplying the superior and inferior lobes of the branchiae. The vascular system of the branchiae. The branchiae are supphed by venous vessels from the abdominal sinus. The efferent branchial vessels open into the pericardium by way of the branchio-pericardial canals (Pl. IL., fig. 16, br.p.c.). The circulation in the superior and inferior lobes of the abdominal appendages, both of which are respira- tory, is different. The interior of the imferior lobe of the branchiae (2nf.lam.) is fenestrated by an irregular system of lacunae, those of the outer side containing venous blood and those of the inner side arterial. On the other hand, the vascular system of the superior lobe (sup. lam.) is very definite and uniform throughout the five pairs. It consists of a venous portion (PI. II., fig. 13, a.6.v.), which is ventral (looking at the gill from the anterior face) to the arterial system of vessels (e.b.v.). The individual arteries and veins interdigitate in a very complete manner, and the vascular supply is very rich, as will be seen by reference to the figure (PI. III., fig. 3). On this account, the superior gills cannot be looked upon as being merely opercular in function in this animal, but are certainly respiratory appendages of a very perfect nature. The blood is colourless and contains nucleated corpuscles which vary in size. As in most anthropods, it is very coagulable. LIGIA. 87 NERVOUS SYSTEM. The nervous system (PI. III., fig. 4) is composed of a series of paired ganglia, the ganglia of each pair being closely apposed; the ganglia are connected by distinct commissures. The supra-oesophageal or cerebral ganglion (cer. g.) extends across the space between the eyes, anterior and dorsal to the gut. The ganglion cells have large deeply- staining nuclei, and the fibres arising from them decussate and connect the ganglia. In the supra-oesophageal ganglia several lobes can be distinguished. On the dorsal side there is a large pair of lobes, from the sides of which the optic stalks arise. Hach of these optic stalks consists of a proximal lobe, connected by closely apposed parallel fibres with a distal lobe, from’ which the optic fibres arise and run direct to the retinulae. On the ventral sides of the superior lobes a small pair of median lobes is situated; these are anterior to, and connected with, a larger pair of ventral lobes, the olfactory lobes, from which the large antennal nerves (ant.n.) arise. The supra- oesophageal ganglion is connected with the sub- oesophageal ganglion by a pair of peri-oesophageal com- missures. The sub-oesophageal ganglionic mass is perforated near the anterior end by a vertical muscle band. The mouth-parts are innervated by two pairs of nerves (m.p.n.), the first of which arises lateral to the perforation, and the second pair posterior to this, and latero-ventral. A pair of nerves (g.n.) arise posterior to these and run ventrally to the stomach. ‘The sub-oesophageal ganglion is connected with the ganglia of the first thoracic segment by a pair of cords, from the middle of each of which a bifurcating nerve arises supplying the muscles of the body. 88 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. There are seven pairs of thoracic ganglia (th. g.), the ganglia of each pair being closely connected., The pairs of ganglia are connected by commissures, those between the sixth and seventh pairs of gangla being very short. Hach pair of thoracic ganglia gives off a pair of stout nerves, which split into several parts, and supply the appendages. From the middle of the length of the commissures connecting the ganglia, nerves arise which innervate the muscles of the body. In Lrgia the abdominal ganglia are all fused into a single ganglionic mass (ab.g.) situated in the anterior region of the abdomen. In the Isopoda all stages are found, from the original separate condition of the abdominal ganglia to the fused condition occurring in Ligia. From the abdominal ganglion nerves arise, which supply the appendages and muscles of the abdomen; a large pair of nerves run from the posterior end of the ganglion to supply the uropoda. A small median nerve runs between the commissures connecting the thoracic ganglia from the sub-oesophageal ganglion to the seventh pair of thoracic ganglia. It has been termed the ‘sympathetic’ nerve, but there is no evidence that it is of such a nature. SENSORY ORGANS. The eyes.—As the eyes of the Lzgia oceanica are different from the eyes of other Isopods, which have been described by Parker, Beddard and others, their structure will be given in detail. They are compound and sessile, occupying almost the whole of the lateral region of the head. In the mature animal each eye consists of upwards of 500 ommatidia. The corneal cuticula is facetted. The corneal facets of the LIGHA:. 89 central ommatidia are plano-convex, with the flat side internal; those in the peripheral regions have the inner side slightly convex also. In a single ommatidium (PI. IV.; fig. 1) the following parts can be recognised. The internal face of the corneal cuticular facet (corn. cut.) is covered with two thin cells, the subcorneal hypodermal cells (s.c. hyp.) The nuclei of these cells can be seen in the figure. Internal to these are the nuclei of the two cone cells. (nue. con.). Hach of the cone cells secretes a hemispherical transparent mass (con.), the two segments with their flat surfaces apposed form the cone. The cone cells surround the cone segments, and on the proximal side form two sub-cylindrical, transparent accessory cones (acc. con.), which is the most interesting and exceptional feature of this eye. The cone cells are surrounded by two pigment cells (pg.c.) which completely invest the upper half of each ommatidium. The retinula consists of six retinulae cells, and not seven, as stated by Beddard (1888). In this it agrees with Idotea ovata, which also has six retinulae cells (Parker, 1891). The retinulae cells (ret.) have fibrillar axes which are continuous with those of the nerve fibres. The six nuclei of the retinulae cells are situated at their proximal ends (nuc. ret.). The rhabdom consists of six individual rhabdomeres, each rhabdomere (rh.) remaining attached to the retinula cell which forms it, and separate throughout its length from the other rhabdomeres. There is a dense mass of pigment (pg.) between each of the rhabdomeres and its retinula cell. This may have been formed by the retinula cell, which also contains a large amount of pigment, or it may have resulted from an intrusion of a process from one of the pigment cells. The latter view is probably the correct one. The nerve fibrils of the retinulae pierce the basement membrane (b.m.); those 90 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. of a single ommatidium fusing on the proximal side to form a single nerve fibre (ap. n. f.), which runs direct to the distal portion of the optic lobe. Sensory bristles.—On the flagellae of the large antennae there are a number of sensory bristles on each segment. These have been figured before by Nemec (1895). Each bristle (Pl. IV., fig. 5, s.6.) is enclosed by a sheath (sh), which is continuous with the rest of the cuticula (ctla.). The thick inner layer of chitin is pierced by a canal, the lumen of which is continuous with that of the bristle. From the bristle, by way of the canal, a number of delicate fibres (n. f.) run and communicate with a number of nerve fibres lying beneath the hypodermis (hyp.). These sensory bristles are probably the most important organs of sense which the animal possesses, as the antennae are con- tinually in use. Besides their undoubted tactile function, they may take the place of auditory organs. The inner of the two styles of the uropods, as described previously, are probably of a sensory nature. EXcRETORY SYSTEM. The excretory system may be studied in two ways—by feeding animals on food mixed with ammonium carminate or indigo-carmine, and by injecting aqueous solutions of these substances into the body cavity. The latter method is the most satisfactory, but should be supplemented by the first. The injections are made with a hypodermic syringe (or a pipette drawn out to a fine point). The animal is injected on the ventral side, at the base of one of the appendages, and may be killed from 3 to 48 hours after the injection and fixed in absolute alcohol or Flemming’s solution. The excretory organs of Isopods have been studied LIGIA. 91 by Bruntz (1904), with whose results my observations on Ligia oceanica are in agreement. ‘There are four kinds of excretory organs, two of which are nephrocytes, either grouped or scattered; the third is a definite nephridium, or ‘ kidney,’ and the fourth, certain cells in the hepatopancreas. The maxillary kidneys, or nephridia, occur in the basal portion of the second pair of maxillae. They consist of two parts—the saccule and labyrinth. The saccule is a slightly convoluted tube, which Vejdowsky considers is a remnant of the obliterated coelom. It is blind at one end, and opens at the other into the labyrinth. The cells forming the wall of the saccule are large and of excretory nature. The labyrinth communicates with the exterior by an aperture at the base of the second maxilla. The cephalic nephrocytes are situated at the bases of the first antennae. They occur along the ventral and lateral sides of the levator muscles of these appendages. These cells are fairly large; the protoplasm is homo-_ geneous and contains a number of granules. The branchial nephrocytes occur in the abdominal region, dorsal to the attachment of the branchiae. There are five pairs of groups of branchial nephrocytes. They are situated in two lateral lines, each line running above the points of attachment of the abdominal appendages, and their outer edges reach the bases of the epimeral plates. Hach group borders on two segments, the first group bordering on the last thoracic and first abdominal segment. The nephrocytes he on the sides of the branchio- pericardial canal (Pl. II., fig. 16, br. neph.). They are large cells, and the cytoplasm, which is vacuolated, contains many granules. Némec considers the branchial nephrocytes to be a syncytium, but the cell boundaries are very distinct, as Bruntz also noticed. | 92 _ TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Bruntz found that certain small cells of the epithelium of the hepatopancreas, called ‘ Fermentzellen ’ by Weber, pass coloured solutions such as acid fuchsin from the body cavity into the lumen of the duct and are excretory in nature. REPRODUCTIVE ORGANS. The reproductive organs of Ligia oceanica are simple in structure. In the male (PIL IV., fig. 4) there are three pairs of elongate fusiform testes (¢.), each being prolonged into a fine filament. They are situated dorsal to the intestine in the second and third thoracic segments. The three testes of each side are placed in series, and open into a vas deferens (v.d.) of uniform width throughout the greater part of its length. The vasa deferentia are usually white and extended. They are situated on the dorso- lateral sides of the intestine, and extend in a horizontal direction to the seventh thoracic segment. In this segment they narrow abruptly to form two narrow ducts, which curve ventrally round the hepatic tubules; each opens at the base of a styliform appendage (st. ap.) situated on the ventral side of the seventh thoracic segment, on one side the median line. The testes are divided by slight constrictions which indicate different regions of spermatogenesis in the interior. In the process of spermatogenesis the spermatids unite in varying numbers to form colonies, their cell walls disappearing. The nuclei elongate considerably, and very fine fibres are formed which may be attached to the nuclei, but on account of their extreme tenuity the writer is unable to be certain on this point. Miss Nichols found the same difficulty in the spermatogenesis of Oniscus asellus. The whole sperm colony, as it may be termed, together with the cytoplasmic fibres, is surrounded by a protoplasmic LIGIA. 93 sheath. The anterior end of this is flagellate, and by contractions of the slightly muscular walls of the testis it is forced into the vas deferens. Here the sperm colonies are found bound together in masses (PI. IV., fig. 5). The substance which causes this cohesion is probably secreted by a number of large cells which are situated in the anterior end of the vas deferens near the openings of the testes. In the female the ovaries are very conspicuous in the breeding season, entirely filling up the dorsal part of the body cavity. They he at each side of, and beneath, the heart, and extend from the first thoracic segment to about the fourth abdominal segment. They are usually filled with eggs of approximately the same size. A_ short distance behind the middle of the ovary a thin walled oviduct is given off. This opens to the exterior by a small longitudinal slit at the base of the fifth pair of pereiopods, immediately at the base of the brood pouch lamellae, these being the last pair of brood pouch lamellae. The ova are large, oval in shape, and contain a large amount of yolk. In copulating, the male walks on to the back of the female and grasps the anterior thoracic segments with the first three pairs of pereiopods; copulation may last one or more days. After the eggs are extruded, they are carried about by the female in the brood pouch, where they develop; the young remain for a short time im the brood pouch. DEVELOPMENT. The development of Ligia oceanica has been studied by Nusbaum. According to Nusbaum, the early cleavage is discoidal, although MecMurrich has found superficial or centrolecithal segmentation in the Isopods which he has investigated. The first cleavage cell becomes separated 94 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. from the rest of the yolk and lies on the periphery, where it continues to divide, and so forms a cap of blastoderm cells, no cleavage cells remaining in the food yolk. The starting point corresponds to the point where invagination takes place later, that being at the posterior end of the ventral side of the embryo. After the formation of the blastoderm a thickening is formed, corresponding to the future ventral side. This thickening is the germ disc. Shortly afterwards, three divisions of the germ disc make their appearance. Two anterior paired portions (PI. IV., fig. 6, a.m.) represent the formative region of the mesoderm; a median thickening (end.) situated posterior to, and between these, represents the fundament of the endoderm. The germ band is next formed by a probable forward growth of the mesoblast rudiments below the ectoderm, the ectoderm increasing in thickness. Three pairs of buds arise; these are the rudiments of the limbs, and this stage (Pl. IV., fig. 7) corresponds to the Nauplius stage. Behind these rudi- ments, and in front of the anal aperture, is a mesoblastic area, termed the formative area (f.z.), from which the remaining segments of the body will develop. The arrangement of the mesoderm cells in the formative area is extremely regular. At the beginning of the formation of the mid-gut a number of cells (vitellophags) leave the endoderm and wander inwards; they do not take any part in the forma- tion of the mid-gut, but assist in the disintegration of the yolk. The mid-gut is formed from two layers of cells which arise from the endoderm rudiment; these lie below the germ band, and gradually grow round the yolk, each being concave on its inner surface. By means of a ventral median piece they unite in the anterior region, and finally enclose the yolk by growing round to the dorsal side, so LIGIA. 95 that the yolk becomes surrounded by mid-gut epithelium. Two flask-shaped vesicles are constricted off on each side of the anterior end of the mid-gut. These are the rudiments of the hepatic tubules, which are formed by their backward growth, and a longitudinal constriction and division of each rudiment into three parts. The rudiments of the thoracic limbs are biramous (Pl. IV., fig. 8), a fact which is used in support of the theory that the Crustacea have descended from a schizo- podous ancestor. In Zzgia the inner limb (endopodite) alone develops, the exopodite being suppressed. The nervous system arises as a continuous whole from the ventral thickening of the ectoderm between the limb rudiments. The thoracic ganglionic rudiments are paired, but those of the abdominal segments are unpaired. Three pairs of ganglia form the supra-oesophageal ganglion, namely the optic, first and second antennal. The sub- oesophageal ganglion is formed by the fusion of four pairs of ganglha—the mandibular, first and second maxillar and the maxillipedal. There are rudiments of seven ganglia in the abdomen; rudiments also of seven pairs of abdominal appendages are originally formed. The heart is formed by the fusion of two dorso- lateral layers of cells, crescentic in section, and lying dorsal to the eut. The limbs develop successively from before back- wards. In the earlier stages of development the embryo has a dorsal curvature, but later it becomes ventral. On hatching, the young isopod possesses six pairs only of thoracic appendages, which are imperfectly segmented, and not setose; the cephalic region of the young animal is large in proportion to the rest of the animal. It leaves the brood pouch of the female, and after several moults attains the adult form. 96 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. LITERATURE. ALLEN, E. J., 1892. On the Minute Structure of the Gills of Palaemonetes varians. Quart. Journ. Micrs. Sci., Vol. XXXIV, pp. 75-84; 1 pl. BEDDARD, F. E., 1888. On the Minute Structure of the Eyes in certain Cymothoidae. Proc. Roy. Soc. Hdin., Vol. XXXIII, pp. 443- 452; 1 pl. Bruntz, L., 1904. Contribution 4 l’étude de l’Excretion chez es Arthropodes. Arch. Biol., Vol. XX, pp. 217-422; 3 pls. DeELAGE, Y., 1881. Contribution a l’étude de l’appareil circula- toire des Crustacés Edriophthalmes marins, 175 pp. ; 12 pls. FapRicius, J. C.,1798. Entomologia systematica, Suppl., p. 301. LinnEvs, C., 1767. Systema naturae. 12th ed., ii, p. 1061. McMourazicu, J. P., 1895. The Development of Isopods. Jowrn. Morph., Vol. XI, pp. 63-155; 5 pls. Muruin, J. R., 1902. Absorption and Secretion in the Digestive System of the Land Isopods. Proc. Acad. Nat. Sci. Philad., Vol. LIV, pp. 284-360; 23 figs., 1 pl. Nemec, B., 1895. Studie o Isopodech. Vestnik Krdlovské Ceské Spolecnosti Nank. (Prag.), pp. 1-46; 4 pls. Nicuots, M. L., 1902. The Spermatogenesis of Oniscus asellus, with especial reference to the history of the Chromatin. Proc. Amer. Phil. Soc., Vol. XLI, pp. 77-112; 8 pls. Nussaum, J., 1891. Beitrage zur Embryologie der Isopoden. Biol. Cenirlb., Vol. XI, pp. 42-49; 6 figs. 1893. Materyaly do Embryogeniii Histogenii Rownonogéw (Isopoda). Abh. der Krakauer Akad. der Wissenschaften math. nat., Vol. XXV, 99 pp.; 6 pls. Abstract in Biol. Cenirlb., Vol. XIII, pp. 429-435. PaRKER, G. H., 1891. The Compound Eyes of Crustaceans. Bull. Mus. Comp. Zool. Harvard., Vol. XXI, pp. 45-142 ; 10 pls. Pawtowa, Mary, 1895. Ueber ampullenartige Blutcirculations- organe im Kopfe verschiedener Orthopteren. Zool. Anzeiger., Vol. XVIII, pp. 7-18; 1 fig. Sars, G. O., 1896. An Account of the Crustacea of Norway. Isopoda. Vol. II, 270 pp.; 100 pls. LIGIA. 97 EXPLANATION OF PLATES. Puate I. Ingva oceanica (Linn.), dorsal view, x 4. Fig. 1. Big...2. Pig. 3. Fig. 4. Fig. 06. Fig. 6. Bis 7. Fig. 8. Fig.) 9. Fig. 10. Fig. 11. Fig. 12. Fig. 13. Fig. 14 PuateE II. First antenna seen from the side: much enlarged. Second antenna of left side seen from above. Left mandible seen from below. Teeth and molar process of mandible from the posterior side. First maxilla of left side. Second maxilla of left side. Left maxillipede. First pereiopod of male. Seventh pereiopod of male. Second abdominal appendage (or pleopod) of left side of male, showing copulatory style; anterior view. Fourth abdominal appendage (pleopod) of male, posterior view, showing the inner lamella. Third pereiopod of female, attached to the epimeral plate, showing one of the brood pouch lamellae arising from the sternum internal to the appendage. Fourth abdominal appendage of female, anterior view. The inner lamella can be seen by transparency; also the afferent (a.b.v.) and efferent (e.b.v.) branchial vessels. Uropod, showing sensory process at the tip of the inner “tyle. 98 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Fig. 15. Riese: Fig. 17. Interior of the right side of the stomach. The stomach has been opened by a vertical section, a little to the right of the median line so that the median ventral tooth has been removed. The greater part of the cardiac region of the stomach is surrounded by a layer of connective tissue. (a./.t.) antero-lateral tooth; (d.J.) dorsal lamella; (hep.) hepatopancreatic tubule; (/.¢./.) lateral cardiac lamella; (/.c.t.) lateral cardiac tooth; (m.a.t.) median anterior tooth; (oes.) oesophagus; (v./.t.) ventro-lateral tooth; (v.l.p.l.) ventro-lateral pyloric lamella; (v.c..) ventral cardiac tooth. Transverse section through the abdominal region. The abdominal appendage of the left side is omitted. (ad. tzss.) adipose tissue cells; (b.c.) body cavity (haemocoel); (br. neph.) branchial nephrocytes; (br. p.¢.) branchio- pericardial canal; (d.d.m.) dorsal longitudinal muscles; (epim.) epimeron; (At.) heart; (af. lam.) inferior lamella of gill; (dev. m) levator muscle of appendage; (mid. gq.) mid-gut; (p.c¢.) pericardium; (sep.) septum forming floor of pericardium; (swp.lam.) superior lamella of gill; (ty.) typhlosole; (vl. hep.) ventro-lateral hepatopancreatic tubule; (v. hep.) ventral hepatopancreatic tubule; (v.d.m.) ventral longitudinal muscles. Transverse section of two of the rosette-like salivary glands. The left section shows the common duct (¢.d.) of the glandular cells, formed by the uniting of the imtracellular ducts (ic. d.); n.c.d. is the nucleus of the cell which probably forms the common duct. LIGIA. 99 Puate III. Fig. 1. Dissection of the arterial system from the dorsal side. The main arterial trunks are drawn somewhat larger than they are naturally. For the sake of clearness, details of the anatomy have been omitted. (ab.art.) abdominal artery; (cer.g.) cerebral ganglion; (er. art.) crural artery; (ep.art.) epimeral arteries; (gen. art.) genital artery; (hep. art.) hepatic arteries; (At.) heart; (cnt.art.) intestinal artery; (lat.art.) lateral artery; (med. ao.) median aorta; (op.a.) ophthalmic artery; (ost.) ostium; (vent. art.) ventral artery; (i-v11) thoracic arteries. Fig. 2. Artertes of the left side of ventral surface of head and first thoracic segments. (ant. art.) antennal artery; (fac.art.) facial artery; (mand. art.) mandibular artery; (ma’.) artery of first maxilla; (ma".) artery of second maxilla; (mw#p:) artery of maxillipede; (oes. art.) oesophageal artery. Other references as in the preceding figure. Fig. 3. Afferent vessels of the superior lamella of one of the abdominal appendages injected with indigo-carmine from the sternal sinus. Fig. 4. The nervous system, seen from above after the removal of the muscles and viscera. (ab. g.) abdominal ganglion; (ant.n.) antennary nerve; (g.n.) nerve to stomach; (med.n.) median nerve; (m.p.n.) nerves of mouth appendages; (op./.) optic lobes; (swb-oes. g.) sub-oesophageal ganglion; (TZh'.g.) _ first thoracic ganglion. 100 Fig. Fig. Fig. Fig. Fig. Fig. Fig. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. ile Puate LY. Longitudinal section of a single ommatidium. (Drawn with the camera lucida.) (acc. con.) accessory cone; (b.m.) basement membrane; (con.) cone; (corn. cut.) corneal cuticula; (nue. con.) nucleus of cone cell; (nue. ret.) nucleus of the retinular cell; (op. n. f.) optic nerve fibre; (pg.) pigment; (pg.c.) pigment cell; (ret.) retinular cell; (rh.) rhabdomere; (s-c. hyp.) sub-corneal hypodermal cell. Transverse section of ommatidium showing the six retinulae cells and their rhabdomeres. Longitudinal section through the cuticle of a segment of the flagella of the second pair of antennae to show a sensory bristle and its nerve supply. (cA.) thick layer of chitin; (ctla.) cuticula; (hyp.) hypodermal layer; (n.f.) nerve fibrils; (s.b.) sensory bristle; (sh.) sheath of sensory bristle. Generative organs of the male. (t.) testes; opening into (v.d.) the vas deferens, which opens externally by the styliform appendages (Siaps\ee A collection of ‘sperm-colonies’ as they are found in the vas deferens, in the cohesive substance secreted by the latter. Harly stage in the development of the egg, showing the cleavage of the germ disc into the two antero-lateral mesoderm fundaments (a.m.) and the median posterior endoderm fundament (end.). The ‘nauplius’ stage of the development of Ingia, showing the three naupliar appendages. (1.a.) and (2.a.) the first and second pairs of antennae, and the mandibles (mand.); (end.) endoderm fundament; (f.z.) formative zone; (op.) optic lobe. A later stage in the development, showing the elongation of the formative and the formation of appendages, also the rudiments of the ganglia. (an.) anus; (1. and 2. mz.) first and second pairs of maxillae; (map.) maxillipedes. The last three figures are after Nusbaum. eB. C. Memoir XIV. Page I. i t a ee C.G. H. ael. M'Farlene & frskine, Lith. Edin’ UE Gani er te eM B.C Memoir XIV. PLATE IL A aia! if aitiily WiiMi) (nfs PS unf.lam. M¢Farlane & Frekine, Lith. Edin" al ¢ Po 2 CG. Memoir XIV. | PiAge ik OSE c=) <.-- ab. are. ee, ~ _ M‘Farlane & Erskine, Lith. Edin” fc, HH. del. lea IP Aes I, é° i mts * 4 . --/,a c hae P----- 2,@. > BD 6% pee > Bad - ee bee > 133298) @ vat t ‘ ‘ 2 S 3 M‘Farlane & Erskine. Lith. Edin” eG tos, 101 Report on the INVESTIGATIONS carried on during 1906 in connection with the LancasHirE SEA-FISHERIES Lasoratory at the University of Liverpool, and the Sra-FisH HatcHery at Piel, near Barrow. Drawn up by Professor W. A. Herpman, F.R.S., Honorary a Director of the Scientific Work; assisted by Mr. ANDREW Scott, A.L:S., Resident Fisheries Assistant at Piel; and Mr. James Jounstone, B.Sc., Fisheries Assistant at the Liverpool Laboratory. (With plates, charts and figures in the text.) CONTENTS. PAGE 1. Introduction (W. A. H.) - - : = = e 101 2. Sea Fishery Research (W. A. i. )- : E 2 = 109 3. Sea Fish Hatching at Piel (A. 8.) - - - - - 129 4, Classes, Visitors, &c., at Piel (A. S.) = = : = 134 5. Report on the Tow-Nettings (A.S.).— - - . 137 6. Faunistic Notes (A.§8.) - - - s = 3 191 7. Notes on Food of Young Fishes - - = = = 199 8. Fish Hatching in Norway (G. Dannevig) - ~ 204 9. Fish Hatching in Norway (K. Dahl) - - 2 209 10. Marked Fish Experiments (J. J.) me 226 11. Parasites of Fishes (J. J.) - - : . 270 12. Parasites of Fishes (H. M. codcoel) - - = 2 304 18. Ichthyological Notes (J. J.) = = : 309 14. Notes on Food of Fishes (J. J. ) - - : - - 316 15. Bacteriological Investigations (J. J.) - : - 328 INTRODUCTION AND GENERAL ACCOUNT OF THE WORK. | During 1906 the system of quarterly reports which was referred to in the Introduction of the last Annual Report has been continued with the view of bringing the more important matters dealt with in the laboratory before the notice of the Scientific Sub-Committee with as little delay as may be, and has also served to keep the Committee generally better informed as to the progress of the scientific work. The Board of Agriculture and Fisheries have sent various specimens to the Liverpool laboratory to be examined. Their Inspectors have visited the laboratory H 102 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. more than once during the year, and a report on the work carried out has been furnished, at their request, to the Board. A considerable part of the work is of a routine nature and does not differ much from that reported on last year. Mr. Scott has been chiefly occupied at Piel with flat-fish hatching, with the fisheries classes, and with making as complete an estimate as possible of the minute floating life in the sea all over the district. Mr. Johnstone’s chief ~ work has been, as usual, the conducting of the fishermen’s classes at Piel, the bacteriological examination of samples of shellfish, as required, and the investigation of the parasites and diseases of fish in the Liverpool laboratory. The marked fish experiments, the Hensen net experiments and the collection of the hydrographic samples have also occupied part of the time of both Mr. Johnstone and Mr. Scott. Some of these lines of inquiry will be commented upon now, and others will be found discussed more fully in the sections of the report that follow. Fruat-Fiso HatcHina. Mr. Scott’s report shows that nearly 14 millions of plaice and flounder fry were distributed last season. As I have already pointed out on previous occasions, our numbers in this output do not, and cannot, increase. ‘The really quite inadequate provision of tanks at Piel is strained to the uttermost, as many plaice and as many flounders are accommodated as can possibly be kept healthy. I am satisfied that Mr. Scott is doing all that can be done in the matter, and that until a spawning pond and a better equipment of hatching tanks is provided there is no hope of increasing the output. I may remind the Committee that in the Port Erin Hatchery we have a second establishment adding annually SEA-FISHERIES LABORATORY. 103 to the stock of young flat-fish in the Irish Sea. Last spring over five million plaice fry were hatched from six million eggs and were successfully set free in the open sea to the south and west of the Isle of Man. As before, a certain number of the larve have been left throughout the summer in the open-air spawning pond at Port Erin and reared through their metamorphosis into young plaice. It is very interesting to note that of these young fishes, all of the same age, while those left in the larger pond, under more natural conditions, had attained by September (say five months’ growth) a size of up to nearly five inches in length (the average of 12 being 34 inches), a few that had been placed on exhibition in the Aquarium in a white enamelled basin, although regularly fed, in the same time grew to only one inch. A few thousand put in the smaller western part of the pond were sampled on October 3rd, 162 days after hatching. Twelve taken at random varied in length from 14 inch to 22 inches, the average length being 12 inch. The classes for fishermen at Piel laboratory have been held as usual, and with the usual success. The details are given in Mr. Scott’s Report below. SEA4-FisH Hatcuing in Norway. I print two interesting statements sent to me by Captain Dannevig and Mr. K. Dahl, dealing with the supposed results of adding artificially hatched cod larve to certain Norwegian fjords. These investigators not only write from very different points of view, but unfortunately they do not deal with exactly the same series of observa- tions, so that it becomes difficult to compare their results, and, in fact, on a superficial examination it might be supposed that no correspondence could be traced between 104 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the two series of statements. If, however, we remove the additional observations dealt with by Mr. Dahl, and which were apparently not a part of the joint enquiry agreed upon, some facts remain in common, although-they may be interpreted in different ways. For example, Dannevig shows that in 1903, before his Flodevigen larve were liberated, the Sondeled Fjord yielded 426 cod larve (to over 100 hauls of the seine =4 per haul), while the two following years (after the planting of the fry), averaged, gave 1,328, or about 13 per haul. Removing the July- August observations, which do not appear in Danneyig’s experiments, these numbers agree with what is shown in Dahl’s table, and indicate an increase to about three times the amount. In the case of the Hellefjord, where smaller numbers were dealt with, the correspondence of results is not so clear, and some further explanation is perhaps necessary; but, averaging both localities, Dannevig shows the increase after planting to about double the quantity, which is represented graphically in his diagram. Captain Dannevig, of course, attributes the increase to the liberation of the artificially hatched larve, while Dahl from his additional observations with tow-nets, &., comes to the conclusion that the cod eggs and larve naturally present are so affected in their abundance and distribution by currents in the water which vary from year to year, that the fry added can have no appreciable effect, and that such increases or decreases as may be noted from year to year are due to natural reproduction and hydrographic influences. The impres- sion produced by reading these two papers is, I think, that the observations are still too few to lead to any sure conclusions; but it may be useful to point out that, even if Dahl’s interpretation is correct, it does not follow that Dannevig’s operations are useless. If the addition of 50 SEA-FISHERIES LABORATORY. 105 or 60 millions of young cod adds to the stock in that fjord, the benefit may be great even if from other causes the average per haul in the following year shows a decrease. An addition has been made to the natural stock of fry— whatever that is—and that may well have a beneficial effect upon the future population whatever, as the results of various factors, that may come to be. PLANKTON INVESTIGATIONS. During the past year a larger number of plankton gatherings have been obtained by tow-nets than ever before, and these have been very carefully examined by Mr. Andrew Scott. Four hundred gatherings in one year from a limited area like the Irish Sea ought to give useful information, and the value of the series is increased by the fact that in so many cases we have gatherings taken from different parts of the area on the same day, amounting to practically simultaneous observations. The advantage of having several centres of work in the district —the steamer, the bailiffs, Piel and Port Erin--from which observations can be taken is obvious in an enquiry like this; and Mr. Scott’s lists and tables given below will be seen to be an interesting contribution to a subject that is still imperfectly known. Before any far-reaching con- clusions can be drawn from plankton gatherings it is clear that we must be sure what it is that our nets are catching, and how far the samples caught on different days or at different localities or with different nets are comparable, and can be said to be representative of any time or place. With a view of testing such points I chartered a small steamer for two months last summer and took almost daily gatherings, with several different kinds of tow-nets, during August and September. In all, about 80 samples were collected in 40 days, and the main result is to show a 106 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. puzzling diversity, which indicates that further work is necessary.* I hope to continue this work myself from a small steam-yacht during the coming spring and summer. In addition to the equipment previously used I have — recently obtained a Nansen closing deep-water tow-net with which observations will also be taken. Dr. Travis Jenkins has recently arranged to permit of the steamer taking periodic trips along a fixed line for the purpose of obtaining gatherings with the large Hensen quantitative net. These trips will take place monthly, the line of stations is from Piel Gas buoy to the Great Orme Head, and Mr. Scott will carry on the work. The series was started in January, 1907, and the second trip is now taking place. HyYDROGRAPHICAL OBSERVATIONS. The scheme of hydrographic observations which was proposed in the Introduction to the last Annual Report was duly sanctioned by the Committee, the necessary apparatus was obtained, and the practical work was started in summer. ‘The observations are carried out by Mr. Johnstone on the steamer, and the samples of sea- water obtained are analysed in the laboratory by Dr. Basset, to whom we are very much indebted for the time and trouble he is kindly giving to the work. It is too soon yet to come to any conclusions, so I merely place on record the following list of observations made : — Three cruises were made during 1906 :— (1) 4-5 July, 1906. (2) 18-19 Sept., 1906. (3) 13-14 Nov., 1906. * A fuller account of these observations was given in an address delivered to the Biological Society, and published in the Annual Report of the Liverpool Marine Biology Committee in December. I do not repeat the information here because I am convinced that further work is required and that I shall be able to give a better account of the whole subject by waiting till next year. SEA-FISHERIES LABORATORY. 107 On each cruise two lines of stations were worked :—— (1) Piel Gas Buoy, Walney Ch. to Maughold Head. (2) Calf of Man to Holyhead. Four “ stations’ were worked on each line : — (1) 6 miles N.W. from Piel Gas Buoy. (2) 1 5 o (3) 2s ee o . (4) 32 9 29 9 29 and (5) 7 miles S. by W. from Calf of Man. (GG) oar 6 a i Ginzo ,, e 32 a (3) 3 x ' It was decided that observations should also be made in Carnarvon and Cardigan Bays during the third cruise, but bad weather prevented these from being carried out. BACTERIOLOGICAL Work. A good deal of Mr. Johnstone’s time has been occupied with questions of sewage contamination of shell- fish beds on the Lancashire and North Wales Coasts. The investigation of such cases, both on the ground, where adequate samples have to be taken, and also subsequently, as a matter of bacteriology in the laboratory, is of very ereat importance and some difficulty. The responsibility attaching to such work is very great, because of the possible danger to public health on the one hand, and the possibility of injuring a prosperous industry on the other. The Scientific Sub-Committee have had several carefully considered reports from our laboratory during the year, and the results of Mr. Johnstone’s examination of the Morecambe and the Conway mussel beds are given below. 108 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. OTHER WorRK. The experiments with marked fish are fully discussed in Mr. Johnstone’s article below, and the other sections of this report dealing with the Parasites and the Food of fishes, the Ichthyological notes and the Faunistic notes | explain themselves and require no further comment. As the present winter is a critical time in the history of sea-fisheries research in this country—on account of the approaching termination of the five-year period of the International North Sea Investigations, and the hope that on the conclusion of that work Government may be willing to subsidise similar work on other parts of the coast—I have thought it desirable to draw up, for the information of the Committee, a statement of the present situation, as it now appears to me. I print this article on ‘“‘Sea-Fisheries Research in England” with the view, not of criticising any particular plan or piece of work, but of pointing out that the present juncture seems to give an opportunity of uniting all interests round the three coasts of England in a comprehensive national scheme. W. A. HERDMAN. FIsHERIES LABORATORY, UNIVERSITY OF LIVERPOOL, February 5th, 1907. SEA-FISHERIES LABORATORY. 109 SEA-FISHERIES RESEARCH IN ENGLAND (A statement bearing on the present situation). By W. A. Herpmay, F.R.S. The position of this country in connection with Sea- Fisheries investigations at the present juncture is most interesting; and the decision which H.M. Government will be called upon to make, early in 1907, as to the measure of official recognition, control and support to be given to such investigations on different parts of the coast will be of unusual importance, since it cannot but have a profound effect upon future work and _ knowledge bearing on fishery questions. In the recent history of the subject the only period approaching the present in interest and importance is the winter and spring of 1901-2. It may be useful to recall that at that time, five years ago, two quite unusual events had taken place. One of these was the announcement, on January 3lst, that the then Government had given its adhesion for a period of several years to the International Scheme of North Sea Investigation; and the second was the presentation to Parliament, and subsequent publication, of the Report of a Committee of Government Officials, Fisheries Experts, and Zoologists, to whom had been referred the whole question of scientific investigations in connection with British Sea-F isheries. This latter body, the “Ichthyological Research Committee,” was appointed by the President of the Board of Trade (the Government Department which at that time included Fisheries) in August, 1901, and meetings for the examination of witnesses and discussion of results were held during the twelve months to I 110 ‘TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. September, 1902. The Report of the Committee, which was issued as a Parliamentary paper about the end of the year, recommended a comprehensive National Scheme of imvestigation centring, as regards England, in the Government Department, co-relating and uniting the energies of the various administrative and investigating bodies, and giving the necessary support to a marine jaboratory on each of the three coasts. Legislative action upon these various recommen- dations was, however, postponed, because the Govern- ment had meanwhile become engaged to participate for a period of years in the International scheme of investigations; but the Report of the Ichthyological Committee was received with marked approval by most, if not all, of the Sea-Fisheries Authorities of England and Wales; and in answer to representations made at successive annual statutory meetings, the President of the Board (formerly of Trade, latterly of Agriculture and Fisheries), in the chair, has stated on the various occasions that at the conclusion of the limited period for which the International work had been guaranteed, the question of a National Scheme would be considered, and the claims of the Local Sea-Fisheries Districts would then receive attention from the Government. For example, larl Carrington, the present President of the Board of Agriculture and Fisheries, at the meeting in the House of Lords on 14th June, 1906, after expressing his sympathy, stated that he “would leave no stone unturned” in trying to get from the Treasury some money for such a National Scheme as was desired, and he ended by appealing to the Local Authorities present to give him all the support in their power when the time came [see Bluebook, Cd. 3063, p. 10]. Within the next few weeks is clearly the SEA-FISHERIES LABORATORY. 111 proper time for compliance with Lord Carrington’s request, since the five-year period of the International work expires in July, 1907, and if any part of the money then set free is to be secured for Local Sea-Fisheries investigation it ought to be included in the estimates which will shortly be prepared for Parliament. Under these circumstances, it seems desirable that a somewhat detailed statement should be made, avoiding as far as possible critical and controversial matters, but setting forth plainly the present position and the alternatives that are now placed before the country. Tut INTERNATIONAL SCHEME. Some years ago a group of distinguished foreign meteorologists and biologists put forward a scheme for international co-operation in the hydrographic and biological investigation of certain North-Huropean seas (North Sea, Baltic, Norwegian Sea, &c.), in the hope that the data thus acquired might throw light upon weather prognostication in the interests of navigation and commerce (a matter of some importance to the more northern nations) as well as upon the conditions and prospects of the fishing industries in those seas. ‘The matter was taken up by the Swedish Government, and on their invitation Great Britain, Germany, Russia, and other countries bordering upon the North Sea and the Baltic, agreed to participate in the investigation and to contribute towards the expenses of a central organisation. Great Britain, however, only consented in the first instance to take part in the work and contribute to the expenses for a period of three years; but later on the time was extended so as to complete the five 112 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. years for which other nations were pledged, but at the same time it was made clear to the International Council that our Government did not contemplate any further continuance of the work. (“‘ The delegates are requested to impress upon their foreign colleagues that it is not the intention of His Majesty’s Government to participate in the investigations on the present footing after 22nd July, 1907.”—Blue-book Cd. 3165, p. 9). The cost has been great—the British share of the total expense amounted to about £70,000, or £14,000 per annum, of which £5,500 was allotted to work done off the Scottish Coasts and £5,500 to that on the East and South Coasts of England—the remainder being required for expenses of administration and the central organisa- tion. No part of the money was expended on Ireland, nor on the Western Coasts of England and Wales. The Scottish portion of the work, it was arranged, should be carried out by the officials of the Fishery Board for Scotland under the Scottish Office; and the Knghsh portion by the Marine Biological Association, a well-known scientific body controlled by a council of between 30 and 40 members, under the presidency of Professor Ray Lankester, and having a large laboratory and headquarters at Plymouth, with a smaller branch establishment at Lowestoft for the special purposes of the International work. The Local Sea-Fisheries Committees around the coasts of England had no part in the work, nor had the Govern- ment Department chiefly concerned in the subject (hg Board of Agriculture and Fisheries). The International investigations have been controlled by a Council (“Conseil Permanent International pour Exploration de la Mer’’), the Executive of which is a “ Bureau,” having its seat at Copenhagen and its Central SEA-FISHERIES LABORATORY. 118 Laboratory at Christiania. The Bureau consists of an mner circle of three ordinary members, viz.: — Dr. W. Herwig (Germany) as President, Dr. O. Pettersson (Sweden) as Vice-President, Dr. P. P. ©. Hoek (Holland) as Secretary ; and an outer circle of four extra-ordinary members, Capt. Drechsel (Denmark) as Hon. Treasurer, Dr. F. Nansen (Norway), Director of the Laboratory, Prof. O. von Grimm (Russia), and Prof. D’Arcy W. Thompson (Scotland). Thus Great Britain is not represented on the inner circle, and England has no representation even on the outer body, although HEngland’s interests in the North Sea Fisheries are admitted to be paramount. The International investigations have been carried on with energy and enthusiasm for the last four and a half years, and the reports that have already appeared— including “ Rapports et Proces-verbaux,” “‘ Bulletins des Résultats,” “* Publications de Circonstance ” issued by the “Conseil Permanent International,” and the Blue-bocks and other publications of our own and other Governments —form an enormous body of literature, containing much that is of the greatest interest to scientific men, and some of which will, no doubt, one day find its place in a scheme of knowledge that is useful in connection with practical fisheries questions. It is scarcely necessary to point out that a clear distinction can be drawn between a scheme of investi- gation (1) as a piece of pure scientific research, and (2) as a practical enquiry which will solve within a giver time and by given means questions of importance tc particular industries. Of the interest and importance, to science, of the International work as a piece of pure research there ought to be, and probably there is, ua 114 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. doubt. We must all be in sympathy with the work from that point of view. It is oceanographic research of the most desirable and fascinating kind, which is bound to yield qualitative results of great interest to biologists— and probably also to hydrographers. But there is the greatest difference between (1) such qualitative results which add eertain new facts to science, and in regard to the economic importance of which all that can be said is that each and every scientific fact will some day find its application ant may then become of commercial importance to mankind, and (2) immediate quantitative results given as the outcome of investigations directed to particular practical problems. Viewed as the former, the International results are valued contributions to science; the facts are useful whether few or many, whether they establish any definite principles or not, and the conclusions put forward are welcome if regarded only as scientific speculations which stimulate and suggest and may lead eventually to definite proof. It is when put forward as quantitative results directly applicable to practical questions that grave doubts arise as to the adequacy of the methods to solve the problems and as to the sufficiency of the observations to justify the economic conclusions. I have no desire to assume a critical aspect, or to try to find defects in the International or any other useful work. AI] such investigations must have defects, and I much prefer to appreciate the valuable contributions to scientific knowledge made by the International Council: they have added greatly to the sum of our data in the Hydrography and Biology of the North Sea. If those who prosecute and those who support this investigation will declare that they regard it as scientific research undertaken jointly with foreign savants with the object SHA-FISHERIES LABORATORY. 115 of acquiring certain scientific data—which may, or may not, have a bearing upon fishery questions—then I, for one, will cordially approve of the enlightened action of our Government in endowing scientific research to that extent. But the British Delegates at the International meetings have made it quite clear that our country took part in the scheme with the expectation of obtaining practical results in the fixed period of years.* How unlikely it is that any such results will be obtained by the methods, in the time, can only be realised by those who have had considerable experience of the irregularity of distribution of fish and other living things in the sea, and the difficulty of obtaining samples that are truly repre- sentative of an extensive area. It is obvious that if we are to have the benefit that was promised from international co-operation, any conclusions arrived at should be put forward with the full authority of the International Council, and as the deliberate opinion of the united wisdom of the experts; but it is evident from the published results that a con- siderable amount of difference of opinion already exists. In both the hydrographical and the biological sections we find the conclusions of some of the investigators rejected by their fellow-workers | see Blue-book, Cd. 3165, p- 6, and paragraph 9 on p. 7; also Cd. 2966, p. 47]. Asa matter of pure science this is of no great importance, it may be helpful rather than harmful, since it tends to promote research and discovery; but when it 1s a question of conclusions that may be applicable to the industries * In the Report of the Christiania Conference, in 1901, we are told, under the heading ‘‘ Guarantees of Practical Results,’”’ that it was agreed ‘‘that the work of summarizing the practical results of the scientific explorations should not be left to the end of the five years’ period, but should be undertaken from year to year. Consequently, by now we ought to have the ‘‘practical results’’ of the first four years in our hands. 116 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the case is very different. If any of these conclusions are lable to be made a basis for action by the Government or by any Fisheries Authority, they ought obviously to be subjected to the same open discussion and free criticism as would take place in the case of an ordinary scientific theory. This will, no doubt, be the case eventually with the International results, but in the meantime it 1s most undesirable that conclusions or opinions expressed authoritatively should be put forward unsupported by the detailed observations on which they are based. THe IcatrHyvotocicaL RESEARCH COMMITTEE. At the same time that Great Britain undertook to participate for a limited number of years in the Inter- national investigations, the Committee above referred to was sitting at the Board of Trade charged to report “as to the best means by which the -State or local authorities can assist scientific research as applied to problems affecting the fisheries of Great Britain and Ireland.” This Committee, which reported in 1902, consisted of four representatives of Government departments (the late Mr. 8. EH. Spring-Rice, of the Treasury; Mr. Pelham, of the Board of Trade; Sir. C. Scott-Moncrieff and Sheriff Crawford, of the Scottish Office); and four zoologists or fisheries experts (Mr. Walter E. Archer, of the English Fisheries Depart- ment; the Rev. W. Spotswood Green, of the Irish Fisheries Department; Professor J. Arthur Thomson, of Aberdeen; and Professor W. A. Herdman, of Liverpool). After the detailed examination of many witnesses representing science, the fishing industries, and all otber interests concerned, and some discussion of results, the four experts were requested by their colleagues to SEA-FISHERINS LABORATORY. 117 draw up a Memorandzem as to the relations of the Inter- national scheme to the most pressing fishery problems and the methods to be adopted in the solution of such problems. This Memorandum was adopted by the Committee and is printed on p. xxu. of the Report (Blue book Cd. 1312). If the argument in this Memorandum of the Ichthyological Committee is correct, grave doubt is cast upon the validity of any results which might be obtained solely by methods proposed in the “ Christiania Programme ’’—the revised or second official programme of the International work. It is evident from an examination of the official publications of the Inter- national Council that some such doubts must at a later date have occurred to those engaged in the work. For example, in August, 1902, at the first meeting held after the memorandum above referred to had been presented, the Council resolved that it was not possible to undertake the biological portion of the “ Christiania Programme ” in its totality, and decided to restrict the investigation to certain problems [Cd. 1313, p. 102]. Again, in 1904, it was recognised that the methods hitherto adopted were inadequate for the solution of these problems, and the instructions to the British delegates [Cd. 2966, p. 382] caused still further alteration in the International programme. ‘Then, in 1905, the quarterly “ seasonal cruises” (in February, May, August and November), which were a very fundamental point in the original scheme, and which had been criticised in the Report of the Ichthyological Committee, were apparently recognised as being inadequate and were supplemented by more frequent observations [Cd. 2966, pp. 54, 172, 174, 175 App. B, also Cd. 3165, p. 14]. Thus the progress of events during the last four 118 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. years has, on the whole, tended to show that the criticisms put forward in the Report of the Ichthyological Research Committee were well founded, and served to indicate the direction in which the International Scheme of work has required to be modified. Under these circumstances, we turn now with the more confidence to the constructive portion of that Committee’s Report in order to enquire how far the recommendations then made will meet the needs of the situation at the present juncture. The Committee recommended a National Scheme of fisheries research and organisation, into the constituent elements of which they entered in considerable detail. This scheme provides what has long been felt and often expressed as a great need in England, viz., a Central Fisheries Board, having at its command laboratories, vessels and scientific men on all the coasts, and it also endeavours to ensure the sympathy and utilise the energies of the District Committees, by giving them adequate representation on the Central Body and by delegating the work on the several coasts to the local investigators. The points dealt with in the Report are (1) Statistics, (2) Expert Staff, (38) Laboratories, (4) Vessels, (5) Central Authority, and (6) Co-operation with Scotland and Ireland; and the recommendations under these heads may be briefly summarised, with comments, as follows :— (1) Statistics —The Committee insist upon the necessity for much fuller and more accurate statistics as to the results of the commercial fisheries than are now supplied. Returns must be obtained from the masters of fishing vessels, and it is very desirable that full returns of all fish caught, giving the localities and other particulars, should be made compulsory. The official system of collection of fisheries statistics has been improved at many ports since 1902, but further SEA-FISHERIES LABORATORY. 119 development around the coast generally is much to be desired. (2) Expert Starr.—In the first place a staff of trained assistants is required at the principal fishing ports to deal with the returns obtained from the boats, to inspect the catches landed and to select samples for further examination. Certain observations can be made and certain particulars noted by such assistants carrying on statistical work at the ports, but it is not suggested that they need be laboratory biologists. Then, secondly, the samples selected, along with the statistical and any other information, should be sent for more detailed examination to the recognised marine laboratory of that coast, there to be dealt with by the Director and his scientific assistants. (3) Lasoratories.—The Ichthyological Committee point out that “the fishery interests of the Hast Coast, the South Coast and the West Coast of England, respectively, are, to some extent, distinct,” and they propose that these three coasts should be treated independently, each having it own marine laboratory, staff of workers, surveying vessel, and representatives on the Central Authority. It is recommended that, if possible, arrangements be made so that (1) the Marine Biological Association Laboratory at Plymouth be officially recognised as the headquarters for scientific fisheries work on the South Coast, say from the Hstuary of the Thames to the Bristol Channel; (2) that the Liverpool Marine Biological and Fishery Laboratories be similarly the centre for work on the West Coast ; and (3) that a laboratory be established to perform similar functions on the Kast Coast. If the new Marine Biological Station which is now being erected at Cullercoats, in the Northumberland Committee’s District, had then been in existence, there can be no doubt that the 120 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Ichthyological Committee would have recommended that that laboratory should be recognised as the centre for work on the East Coast. It is possible, also, that, under ; ae Os: 9 \ / : Aberaten Lu? Het? oO HE ¥ a >] i Eee _ FOR CFISHERY COUNCIL cu SAE FOR Ei iG ak AINeD (x peyhes coast .. sou! Hic. 1. Sketch Map of the British Islands, for the purpose of indicating the position of the chief marine laboratories and sea-fish hatcheries, and the proposed division of the coast of Hngland into three great fisheries districts—The Hast coast, the South and the West. the conditions now existing, the recommendation might have been added that the Lowestoft Laboratory should be SEA-FISHERIES LABORATORY. 121 taken over, if that is possible, from the Marine Biologicat Association, and should be the home laboratory of the Fisheries Department of the Board of Agriculture and Fisheries, in order to furnish the Government Depart- ment with the laboratories, experimental tanks and scientific assistants, without which the officials cannot be expected to carry on original investigations. On the other hand, if the view be held that the Government Department should not itself undertake any actual marine investigations, but should delegate such work to the different laboratories round the coast, a natural division of the area would be for the Marine Biological Association, with its laboratories at Plymouth and Lowestoft, to conduct the explorations from Cornwall to the Wash, while the District Committees North of that point, with the laboratory at Cullercoats, would undertake the remainder of the East Coast. The exact details of such divisions are not of prime importance, the essential point being that the Ichthyological Committee in making their recommendations in regard to laboratories for the three coasts made use to the fullest extent of existing institutions. (4) VussEts.—Hach of the three coasts, it is proposed, should have a research or surveying steamer of the type of a modern steam trawler, especially fitted up for scientific investigations and carrying on its work in connection with the laboratory of that coast. (5) Centra Autruority.—The Ichthyological Com- mittee recommend the formation of a “ Fishery Council +) for England,” consisting of representatives of (a) the Board of Agriculture and Fisheries, (6) the local Sea- Fisheries Authorities of the three coasts, and (c) the scientific men in charge of the three marine laboratories. This Fishery Council would be, to some extent, analogous 122 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. to the Fishery Board for Scotland, but more suitable in other respects to England, where strictly local fisheries are more common than in Scotland, and where local needs have to be more closely studied. The Council would, it is hoped, be so representative as to unite the various fisheries’ interests and ensure the co-operation of the different organisations, local and central, now working at fishery problems. It is suggested that the Fishery Council should meet monthly, or more often as occasion may require, under the Board of Agriculture and Fisheries, to formulate and control schemes of investi- gation, to receive reports on work done on the three coasts and co-relate observations, to recommend the allocation of grants to the laboratories, and, generally, to report to Government, through the Board of Agriculture and Fisheries, on the needs and results of the work carried on by the steamers and the laboratories. INTERNATIONAL Co-oPpERATION.—In order to secure uniformity of action between the Fisheries organisations in Jngland, Scotland and _ Ireland, to prevent overlapping of areas and of investi- gations, and to arrange as to any sub-division of work between the three countries, or with foreign nations, the Ichthyological Committee recommend that quarterly conferences should be held between representatives of the Fishery Council for England, the Fishery Board for Scotland and the Irish Fishery Department. “The meetings of this conference would give an opportunity to the members of the three Central Authorities to compare notes, to obtain information as to what is being done in the three countries, and to make suggestions to the three Central Authorities as to what particular work should be undertaken by each” (Report, p. xv.). It is only to this extent—Quarterly Conferences—that the Ichthyological SEA-FISHERIES LABORATORY. 128 Committee have considered it practicable to constitute one Central Fisheries Department for the United Kingdom. We may quote finally paragraph 39 from the “Concluding Observations” of the Report:— “The Committee believe that by carrying out these recommendations the State would recognise, co-relate and control the work of the existing independent organisations in the United Kingdom, and would build up a scheme of Fishery Research of a thoroughly practical character, centring, as regards Hngland, in the Board [of Agri- culture and Fisheries |, and, at the same time, in intimate contact with the fishing trade, the District Committees and the scientific laboratories round the coast.” Tur PRESENT SITUATION. The adoption of these recommendations made in 1902 by the Ichthyological Committee’s Report would, it is believed, satisfy the wishes and claims of the District Committees on the East and West Coasts, but it seems improbable that that course would satisfy the Marine Biological Association, and it is quite incompatible with a continuance of the International work as at present carried on. It seems doubtful, however, whether the officials of the Marine Biological Association desire that the International work should be continued under its present organisation. The Council of the Marine Biological Association have recently issued various circulars and reports, and have organised a deputation to the Chancellor of the Exchequer, asking H.M. Government to give them control, not merely of the whole amount they have been administering annually in the North Sea investigations, but also of an additional £2,000 a year for the Plymouth Laboratory, making a total annual grant of £8,000, with no limit of time specified, Jt is very 124 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. difficult, from these reports and the speeches of prominent members of the Council, to understand exactly what are the intentions or wishes of the Marine Biological Association in regard to the International Council and Bureau. They ask quite definitely to be allowed to continue the International investigations; but a passage in the speech by the Chairman of the MBA. Council suggests that they are contemplating the severance of their present connection with the International Council. If that is the case, it is surely of primary importance to all concerned in the discussion of these questions to know under what organisation they propose to work. If they do not desire to continue under the direction of the “‘ Conseil Permanent International,” are they prepared to adopt the recommendations of the Ichthyological Research Committee to such an extent as will satisfy the claims of the Sea fisheries District Committees of the East and West Coasts, or is it their intention to claim all the money that has recently been expended by England on the International work, and such additional grant as the Government may give, to spend after July on their own work under their own organisation, in independence alike of the International Council and of the constituted Sea-Fisheries Authorities around the coast? Surely their position in this matter should be made quite clear before their claim to the administration of the whole of the English portion of the International fund can be discussed. In one of the circulars that has appeared during the winter, it was suggested that the M.B.A. Council might be increased by allowing the Board of Agriculture and Fisheries, the National Sea Fisheries Protection Associa- tion, and the different Sea-Fisheries Committees, who have established marine laboratories for scientific SEA-FISHERIES LABORATORY. 125 research, and, if necessary, other bodies concerned, the right to nominate one or more members of Council. Tt must be pointed out that although this may seem to be offering an opportunity to Sea-Fishery Committees of participating in the regulation and administration of Sea-Fisheries research under their scheme, it is not doing so im any real sense or on an adequate scale. The Council of the M.B.A. consists of about 388 members (including the President and Vice- Presidents, who have presumably a right to sit on Council), so that unless a considerable number of represen- tatives of, say, the Government department on the one hand and the Local Sea-Fisheries Authorities on the other, were added, so that oll elements were fairly balanced, no real power would be given. But such a greatly enlarged Council would be unwieldy and impracticable; in fact, the Council of the M.B.A., as it stands, is too large a body, besides being unsuitable in other respects, for such specialised work as is contemplated. The Marine Biological Association is a distinguished Scientific Institution, one of the primary purposes of which is the promotion of research in pure science and the higher education of young Zoologists from the Universities. Academically it helds a high position and its educational value in pure science might be of national importance. It is on those lines that, in the opinion of some of its own members and loyal supporters, it ought to develop rather than in connection with the fishing industries. As a scientific and educa- tional institution 1t is worthy of all possible encourage- ment and support, and it is to be hoped that H.M. Government will give a liberal subsidy to the Plymouth laboratory and other similar institutions for purposes of research in pure science, 126 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. But with the view of collecting, examiming and co-ordinating such scientific researches at different centres and of applying them to specific fishery problems, and of making use of the money set free by the termination of the international work and such other funds as H.M. Government can devote to this important national object, it is essential to have a small working body of experts such as was recommended in the Report of the Ichthyological Committee—men who have been, and are, actively and sympathetically in touch both with the various fishing industries and the various methods of scientific research that can be applied to them. As examples of such experts may be taken Prof. McIntosh and Dr. Fulton, in Scotland; Mr. W. S. Green and Mr. E. W. L. Holt, in Ireland; and Mr. Walter E. Archer, in London. The academic Zoologists on the Council of the M.B.A. are all eminent men in their own special lines of research, but would, most of them, I hope, be unwilling to lay claim to expert knowledge on fishery problems. | It is, surely, unfortunate in the interests of science that the Council of the Marine Biological Association should have recently appealed to scientific men in general at the Universities to sign a petition addressed to the Lords Commissioners of H.M. Treasury in support of the work carried on by the International Council and its continuance in the hands of the Marine Biological Association. It is probable that some, at least, of the more or less distinguished Zoologists, Botanists, Geologists, Physiologists, Pathologists, Astronomers, Chemists, Mathematicians and Anthropologists who have lent their names for this purpose have done so with very imperfect knowledge, if any, of the methods and results of the international work, and very possibly in complete SEA-FISHERIES LABORATORY. 127 ignorance of the other side of the case as represented by the Local Sea-Fisheries Committees. District CoMMITTEES. The administration of the Sea-Fisheries around our coasts 1s now entrusted to District Committees, who, under the Baard of Agriculture and Fisheries, have large powers in regard to the supervision, regulation and promotion of the mdustries. Most of these Committees have under- taken some investigations, and a few of them have done much. They have secured the advice and assistance of scientific men, have helped in the establishment of marine laboratories, and have expended considerable sums upon investigations, both by special steamers and otherwise. It would, in my opinion, be a fatal mistake to do anything that would tend to discourage such excellent local effort or to divorce administration from scientific investigation. All sound regulation of the Fisheries must be based upon accurate and detailed investigation. As the administration has to be applied locally, the investi- gation must be conducted locally. Every part of the coast, every shellfish bed, has its own problems. It is impossible to apply general principles or results obtained elsewhere without an intimate knowledge of the local conditions. The Sea Fisheries Committees which have been conducting such local investigations have a strong claim, not, perhaps, to be relieved entirely of the expense of this necessary work, but to receive a _ substantial contribution from the national purse. The local effort has in some cases been very considerable, funds have been raised, services have been given gratuitously and the work has been carried on energetically and_ successfully. There is no reason to suppose that the local subsidies will 128 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. fail, but they ought to be largely supplemented. The District Committees have been urging their claims for a erant from the Treasury for at least five years, and have received many assurances of sympathy and of ultimate substantial help. The present juncture seems thus to afford an opportunity, such as has not previously occurred, of formulating a comprehensive scheme which will deal with all parts of the coast and unite all.interests. Anything approaching to a monopoly in science is most objection- able. There cannot be a monopoly in work, so there ought to be none in State recognition and support. The North Sea investigations are welcome additions to science, the work of the Marine Biological Association is worthy of all the support that can be given both by scientific men and by the Government, but neither of these organisations covers the whole ground, and any scheme which does not embrace the three seas of England and utilise to the full the various laboratories and Fisheries Authorities around the coast, more or less on the lines of the Ichthyological Committee’s Report, will fail to solve the present problem of Fisheries research in Great Britain. SEA-FISHERIES LABORATORY. 129 SEA-FISH HATCHING AT PIEL. By ANDREW ScorTtT. The results of the hatching work in the spring of 1906 are very similar to those obtained in previous years. The present accommodation for adult fishes is always strained to the limit of safety. Any marked increase in the output could, therefore, only be secured by consider- able additions to the existing tanks. The first eggs were observed on February 17th, but no fertilised ones were obtained till March 14th. The spawning lasted for practically two months. During that time fourteen millions of flounders’ eggs were collected and one and a half millions of plaice eggs. The incubation of the eggs was carried on in the usual manner in the Dannevig apparatus, and yielded nearly fourteen millions of fry. The fry were liberated at intervals, well out in Morecambe Bay. It has been customary to set free the parent fish in the Barrow Channel at the end of each hatching season, but the fate of these fish has always been unknown. At the end of the hatching season in 1908 Mr. Johnstone marked some of the large plaice from the tanks and set them free between Lancashire and the Isle of Man. None of these have been recovered. Another attempt to find out the movements of the fish was made by marking some of the flounders in 1906. These were set free outside the Barrow Channel. A few of the marked flounders were recaptured by fishermen and returned to us, and are dealt with by Mr. Johnstone in his report on fish marking. During the autumn of 1906 the local K 130 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. fishermen reported that several very large plaice had been captured in the Barrow Channel. The sizes of these fish far exceeded those of any flat-fish they had previously taken. The men suggest as a very probable explanation that they were some of our liberated plaice. Capt. Wright also secured one or two of these large fish while trawling for flounders for the tanks. It is quite possible, then, that the large plaice set free at the end of each season remain in the vicinity. When selecting adult plaice for the tanks we depend largely on their size, and hitherto all under fourteen inches in length have been rejected. This size is probably a good average one, but it 1s evidently not always the minimum even for females. This was clearly demonstrated in the spring of 1906. In March, when out with the “ John Fell” collecting material for the classes, two mature female plaice were captured in the same haul. One of these fish was nineteen and a half inches long, and the other was only ten and a half inches. Later on in the month two more mature plaice were captured in the same area as the previous ones. The latter were both eleven and a half inches long. These fish were brought alive to Piel. They all produced eggs which fertilised and developed quite wlormally. The fish were captured between Walney and Isle of Man in the area known as the “Top end of the Hole,’ on March 13th and 20th. According to McIntosh and Masterman™ plaice appear to have very definite spawning grounds, always well offshore and at a depth of about twenty fathoms. Under artificial conditions we find it is possible to get them to spawn in much shallower water. At Port Erin the fish spawn freely in a pond with a maximum depth of ten feet. At the Bay of Nigg Hatchery, belonging to the Fishery *< British Marine Food Fishes, p. 364, SEA-FISHERIES LABORATORY. 131 Board for Scotland, spawning takes place under similar conditions. Our small fish tanks at Piel are only about four feet deep, and we find the fish mature quite normally. During the spring of 1906 we found that some of the adult plaice, collected in Luce Bay in the autumn of 1905, matured when kept in water fourteen inches deep. The fish actually spawned in that depth of water, but the eggs were not fertilised. Very ripe female dabs collected in March, and brought alive to Piel, discharged their eggs in shallow tanks only ten inches deep. In the latter case the eggs were probably too far advanced to be retained by the fish when subjected to the greatly altered conditions of pressure. In the other case, so far as reproduction is concerned, the only apparent difference due to confinement is a slight retarding of tlre maturation of the eggs. We find from the tow-nettings taken in the open sea that plaice eggs were taken in Cardigan Bay on January 23rd, 1906, and off the Liverpool North-west Lightship on the 31st. The occurrence of one plaice egg in Cardigan Bay on December 15th, 1905, and the capture of a spent female plaice in the same bay on January 26th, 1906, has already been recorded by us. Fertilised eggs under artificial conditions were secured at the Bay of Nigg Hatchery on January 20th,t and at Port Erin Hatchery on February 20th, 1906.¢ The following tables give the number of eggs collected and of the fry hatched at Piel, and set free on the dates specified : — + Twenty-fourth Annual Report Fishery Board for Scotland, part iii, p. 112. t Twentieth Annual Report of the Liverpool Marine Biology Committee, p. 17. ©. 132 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Puatce (Pleuronectes platessa, Linn.). March 14 oh ao May 3 Eggs Collected. 30,000 40,000 50,000 60,000 60,000 70,000 90,000 85,000 90,000 95,000 90,000 90,000 90,000 90,000 90,000 85,000 80,000 75,000 50,000 40,000 30,000 20,000 Total Eggs 1,500,000 Fry Set Free. 26,000 ... March 39,000"... 7) Ajouil 44,000 ... be Hil OOO ee. Pe OOOO maa J 62;000: 22 = 19000 m (000) ae ns USO 955. he 84,500... ? CUO . TSE DUOD ox - op SOO murre Fs LQSOUY 26 <5 (270007)... May TVORUUOF sae 2 OOOO ® x. * 66,500... hi 44,000 ... it 34,500... i OOO ue i IO) ee. 3 1,320,000 Total Fry SEA-FISHERIES LABORATORY. FLounpER (Pleuronectes flesus, Linn.). March 14 9) Eggs Collected. 200,000 250,000 300,000 300,000 300,000 450,000 500,000 650,000 750,000 790,000 850,000 950,000 ha 000,000 950,000 900,000 900,000 800,000 750,000 600,000 600,000 500,000 300,000 200,000 200,000 Total Eggs 14,000,000 Total Number of Eggs Total Number of Fry 177,000 223,000 266,000 266,000 310,000 400,000 445,000 580,000 667,000 669,000 757,000 846,000 887,000 847,000 800,000 500,000 712,000 669,000 530,000 032,000 445,000 266,000 178,000 178,000 Fry Set Free. ... March 30 9 .. April 12,450,000 Total Fry. 15,500,000 13,770,000 133 134 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. CLASSES, VISITORS, &c.. AT PIEL. By ANDREW Scorv. Four classes for fishermen were held in the spring of 1906. The Education Committee of the Lancashire County Council voted a sum of money for forty-five studentships open to fishermen in the administrative County of lancaster, The Blackpool Education Committee sent three men, Southport Education Committee two men, Liverpool Education Committee two men, and the Cheshire Education Committee four ‘men. The studentship holders were divided into four classes, three of fifteen each and one of eleven men, as shown by the following lists : — Ist class, held March 12th to 23rd.—J. G. Constable, Askam; R. Parker, Flookburgh; Percy Baxter, Morecambe; G. Parkinson, Morecambe; T. Woodhouse, Morecambe; W. Wilson, Morecambe; R. Abram, Fleetwood; W. Ball, Fleetwood; T. Rawlinson, Fleetwood; Wm. Wright, Fleetwood; J. Abram, Banks ; J. Johnstone (Bunger), Banks; J. Barrow, Blackpool; F, Parr, Blackpool; E. Salthouse, Blackpool. 2nd class, held March 26th to April 6th.—S. Mott, Bardsea; W. Benson, Flookburgh; MR. Gardner, Morecambe; ‘TT. Gerrard, Morecambe; R. Ellwood, Morecambe; J. Wilson, Bolton-le-Sands; JT. Smith, Overton; J. T. Bagot, Knott End; R. Ball, Fleetwood ; J. Leadbetter, Fleetwood; W. Sharpe, Fleetwood; R. Gillett, Lytham; W. G. Parkinson, Lytham; P. Brookfield, Banks; J. Aughton, Banks. 3rd_ class, held April 23rd to May 4th—T. Edmondson, Roosebeck; J. Gardner, Ulverston; J. Procter, Ulverston ; J. Wilkinson, Baicliff; T. Westworth, SEA-FISHERIES LABORATORY. 1385 Flookburgh; W. Bird, Fleetwood; R. Wright, Fleetwood; R. Wilson, Fleetwood; J. R. Croft, Preesall; R. Swarbrick, Hambleton; W. MHadwen, Morecambe; T. Shaw, Morecambe; T. Mayor, More- cambe; R. Abram; Banks; J. Peet, Banks. Ath class, held May 7th to 18th.—J. Bird, Ulverston ; R. Stephenson, Heysham; W. Baxter, Banks; J. Lloyd, Marshside; W. Ball, Southport; W. 4H.» Hosier, Liverpool; W. Whelan, Liverpool; T. Bushell, Parkgate ; T. Matthews, Parkgate; J. Murray, Liscard; W. Bedson, New Brighton. The usual votes of thanks to the Sea Fisheries Committee and to the Education Committee were proposed and carried by the fishermen. The classes for fishermen are now registered. by the Board of Education as evening classes, and each of the above classes was inspected by Mr. M. A. Fenton, one of the Government Inspectors. Mr. Fenton’s report was as follows :— “Demonstrations from the blackboard and abun- “dant individual instruction constitute the teaching ‘“veferred to. The men manipulate admirably, and “seem to apply themselves so as to receive as much “attention as is to be obtained in their fortnight.” A class in Nature Study for school teachers was held on two week nights and the Saturday afternoons during the period covered by the third and fourth classes for fishermen. This class was organised by the Barrow Education Committee, and was attended by eighteen teachers belonging to their schools. The teachers’ class is also recognised by the Board of Education, and registered as an evening school. ‘The following is a copy of the report on the class which was sent to the Barrow Education Committee : — 186 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. “ Board of Education, South Kensington. “ Barrow-in-Furness, Piel, Marine Laboratory, Teachers’ “ Classes, School No. 32,519. “ Report of H.M. Inspector for the year 1905-06, wits “remarks, if any, added by the Board of Education : — ““«This is a very useful class. The teaching is ‘“efficient and thorough, and much interest is ‘“evinced by the students in the study of the ‘* marine forms of the syllabus. ““The work is conducted in a well-equipped ‘“* Laboratory. The members of the Scientific and General Purposes Committees of the Fisheries Committee and members of various Education Committees in the County visited the laboratory, under the leadership of Mr. James Fletcher, while the fishermen’s classes were being conducted. The lbrary has received a number of valuable additions during the year, the most important being :— A set of fifty-eight volumes, published by the Ray Society, containing amongst others the Mono- graphs by Alder & Hancock, Allman, McIntosh, Bowerbank, Brady, Darwin, &c. United States Bulletins of the Fish Commission, 1884-1904. 12 vols. British Fresh-water Fishes, Houghton. 2 vols. Catalogue of Madreporia, vols. 1-5; presented by the British Museum. Monograph on the Isopods of North America. A number of books and pamphlets belonging to the late R. L. Ascroft; presented by Mrs. Ascroft. A number of reprints of papers from the Reports on the Sea and Inland Fisheries of Ireland, 1904- 1905; presented by Mr. E. W. L. Holt, Scientific Adviser. D919 SEA-FISHERIES LABORATORY. Ler Gai ? REPORT ON THE TOW-NETTINGS. By ANDREW Scortr. The collections of pelagic organisms taken by tow-net in various parts of the Irish Sea in 1906 number four hundred. The results from the examination of the material are given in the monthly tables (see below). Although the tables represent the organisms that were present from month to month in particular areas, it does not necessarily follow that they were always in evidence every time a collection was made. Again, the number of records for any station depends largely on the frequency of the fishing. A comparison of the tables given in last years Report shows that Cardigan Bay had a greater variety of free swimming animals than any other area. The number of tow-nettings taken there represented more than one every week, and practically amounted to five each month. The area is a large one, and collections were made in the vicinity of New Quay and Pwllheli by the fishery officers stationed at these places. Then at intervals the fisheries steamer took tow-nettings in various parts of the territorial waters of the bay. This area, therefore, was fairly well investigated in 1906, and the results were naturally high. Another thing to be remembered is that distribution is rarely uniform. Some organisms may be extremely abundant at one spot, and yet at another, perhaps only a few miles away, are conspicuous by their absence. During the year 1906, we derived a good deal of fresh information from the tow-nettings relating to the occur- rence of various important organisms. Owing to various 188 | TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. circumstances, it is almost impossible to get a complete series of collections for a whole year. A continuous daily, or even weekly, sample from one particular region is apt to be interrupted through conditions of weather and other unforeseen agencies, over which there is no control. Again, a gathering taken once a day, once a week, or once a month, may yield some interesting organisms, but one would like to know what had happened in the interval, whether the organism was only a solitary example or part of a rich, widely-diffused shoal. The only area that is represented at least once every month, in 1906, is Cardigan Bay. This division was dealt with in the last Report, and further consideration of its monthly plankton is, therefore, deferred in the meantime. If the tables giving the occurrence of organisms in the areas investigated be compared, it will be noticed that during July, August and September Port Erin had a greater number of organisms than the other stations during that period. This is entirely due to the way the area was investigated and the large number of samples collected. Professor Herdman chartered the small steam yacht “ Madge,” and spent his summer vacation making plankton hauls in the open sea, in the vicinity of Port Erin. The region investigated lay mainly between Bradda Head and the Calf Island. The amount of work that was done can be readily understood when it is stated that on the twenty-nine working days when the “Madge” was at work seventy-three tow- nettings in all were taken. Iven after the observations made from the yacht ended, other tow-nettings were taken both inside and outside Port Erin Bay by Professor Herdman and Mr. Chadwick. The result is that during the period, July 22nd to September 30th, seventy-nine collections were made. More than half that number were taken in the latter month. With such a large amount of material SEA-FISHERIES LABORATORY. 139 to investigate, one would expect that there would be more variety in the plankton than if only one or two samples had been taken in the period. This is the case. In September no less than fifty-eight different kinds of organisms fall to be recorded. Professor Herdman, in his work on the ‘‘ Madge,” used five different kinds of nets, all made of fine silk bolting cloth, as follows :— A Hensen-Petersen closing net, with 200 meshes to the inch. | A small Apstein net, with 212 meshes to the inch. An ordinary tow-net, weighted to work below the surface, 120 meshes to the inch. _ An ordinary surface net, 120 meshes to the inch, used for the first time. An ordinary surface net, 120 meshes to the inch, that had been in use for a year. The five nets were not often used simultaneously, as a rule only the surface and deep-water nets were worked at the same time. Qn measuring and examining the material collected, it was found that, although the gatherings were taken in equal periods of time in a very limited sea area, there was no strict uniformity, either in quantity or kind of organisms captured. Sometimes the surface net contained more material than the deep one, at other times there was more in the deep net than in the surface one. The old surface net appeared to fish better than the new one. ‘The Apstein net invariably had a smaller catch than the ordinary net. When we find such differences in a small section of the Irish Sea,, what must be the conditions when the whole area is fully investigated ? It is proposed, in this Report, to deal with the distribution of organisms, and to show that differences in the nature of the plankton are more frequently than 140 TRANSACTIONS LIVERPOOL. BIOLOGICAL SOCIETY. otherwise co-extensive with the area over which the operations are conducted. It is a well-known fact that land animals and plants have a distribution which depends largely on the physical conditions of their surroundings. One is apt to forget, however, that the same holds good regarding marine life. The sea may appear limitless in extent, but, after all, there are many animals and plants in it that are just as nicely adjusted to their habitat as their relations on land, and any change that takes place in their surroundings has some effect, one way or another, on the inhabitants of the sea. We know far more regarding the inhabitants of the land solely because of the comparative ease in reaching them, compared with the difficulties that le before the marine investigator. The worker amongst land animals and plants can now afford time to deal with variation in structure, &c., but the marine student has not, by any means, exhausted the vast storehouse of the deep of all its novelties. It is only within comparatively recent years that a wide-spread study of marine life has been undertaken. The co-operation of the Governments of various countries and Sea-Fisheries Authorities, along with the efforts put forth by independent naturalists, has done much to stimulate marine research. The result is, we know a great deal more regarding the distribution of certain classes of pelagic and semi-pelagic organisms now than we did a few years ago. Every scientific expedition throws fresh light on the subject. There are still quite a number of organisms whose present distribution is very limited, but whether they will prove on further investigation to be so local is doubtful. Many new forms of Copepoda were brought to light by the investigations conducted on the “Challenger”? over thirty years ago. Some of them were found in tropical seas, and might have been looked SEA-FISHERIES LABORATORY. 141 upon still as true warm-water species, but quite lately one or two of these species have been detected off the Coast of Norway and in the deep cold area of the Faroe Channel. Pelagic forms of Copepoda are probably more widely distributed than might be expected. When one, however, finds such a typical littoral form as Phyllo- thalestris mysis (first described by Claus, from the Mediterranean) having its distribution afterwards extended to Norway and Ceylon, or a more inert species hke Laophontodes bicorms (described from specimens found off the Isle of Man) extending to Cape Verde Islands, there can be little surprise at the occurrence of pelagic forms in unexpected places. In the ordinary course of events, true littoral Copepods are rarely taken in tow-nets, unless these are worked near the bottom. Other means have to be employed for their capture, such as dredging and washing debris from larger invertebrata. It is obvious that it cannot be accurate to state that littoral forms of any kind are absent if the proper methods for collecting them are omitted. A handful of weed washed in weak spirit often brings to light a surprising number of organisms, such as Foraminifera, Ostracoda and littoral Copepoda, that would not be obtained any other way. ‘wo instances of that kind have come under my own notice. One was the washings from a handful of algz, hurriedly gathered on the shore of the Island of Sokotra, which contained a number of interesting Amphipoda and Isopoda. ‘The other was a small quantity of calcareous and other alge collected on the dead coral reef flats and madrepora reefs in the Conflict atoll, off the Coast of British New Guinea. When carefully washed and examined, these debris yielded a large number of littoral Copepoda and Ostracoda. Some of the littoral Copepoda from this distant island appear to be 142 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. identical with forms we occasionally find in the Irish Sea. Quite a number of samples of surface plankton have been taken in limited areas of the Irish Sea on the same day by the steamer, the Fishery officers, Professor Herdman, and Mr. Chadwick in the course of this year. The results are given on the following pages. xcept where otherwise mentioned, the collections were secured with an ordinary open tow-net worked close to the surface. On January 3rd, a collection was taken off Blackpool and another near the Liverpool Bar Lightship. These places are about forty miles apart. The following are the organisms found* in each :— Blackpool. Liverpool Bar. Rhizosolenia semispina ............66. G. ois r. Rhizosolenia shrubsolei ............... : re a es Certo tI POs]. casacemcssuesecenenees ir; ie = CeratlunnMuIsuss. «ect sender oteeecr: cones iT: af. is ING Lea, Ac Ss oGiner cba cee oeae ee een et fr. he — Da GLGGAS wus siewonpseeeiechanaae eee kimaate ab. fat e. COpepodar «5... 4. is .seistaae tose heen ametseiaee ee ab. m2 i AL CMOLD: vscaits aceon oon eee eee c — A Cartia :ClAUISU. co. ca cat ane satin tiene c re Paracalanius so cee ee c r Oithona;: similis! <2 5.9. caceane-beeee c — Oithona nana: sehen eee i — Centropages hamatus ............... i ae — PsevGocalanuste<: sieseceeseecteteemaese ae are The The difference here is very marked, thirteen organisms occurring at Blackpool and only seven at Liverpool Bar. Three out of the seven species of Copepods are absent at the latter place. Samples taken more in the open sea on the following day near the Liverpool North-west Lightship and in Red Wharf Bay—places about forty-five miles apart—gave the following result :— * ab. abundant ; c. common; fr. frequent; r. rare; v.ab. very abundant. SEA-FISHERIES LABORATORY. 148 N.W. Light Ship. Red Wharf Bay. Coscinodiscus concinnus ............... Ie nee — Biddulphia mobiliensis ............... Bi or — SrA MMA ETIPOS, sincne cscs cccsesscceees r — BRNO HONEA aids cise sos oceseCeslveaisencs r 1a PAG WEOORACIMG colic cane covecesuctesscee 1 — BPE OINTEUISE Ga verre teocinacceecscsetcveceaeses 1 ir, SECUNIS: 2:83 OSCR Osa ROE aA eee eee r ab. ME SIMOAECTIS TE wile ciecsSe vac cxs sccwccls sesso et — vel 18 12¢/6 or eae Sais Se alaeiesen sci crcicnincete r i ADEA OANA code centiencocrccscececcces 2 500 — Parathemisto oblivia ...........ce00005 2 — OOM AS Basic nicit vcioeiciac'e seo acisiteveee sees ab. c CRIZIIITS _. SoS UR GORE oC CREE ee eae 15 r BE OHM ee cla civis/scices seis onh ttieaes aces fr. si fr. Centropages hamatus ............... 18 ate — IPARACAIAINUS! 2. .c0csccoossccecesese sees — aes 185 PRC ANEVARCIAUSE. Mo scncinst vo cspdedsseetca. v. ab. fr AAO SIMI .5.. 0000 ace ceeds cocceee fr — RRM IEC cpl ccisasieisa svete vet siv'ss taeae r — The differences between these two collections are quite as marked as in the previous examples. There was, evidently, a more abundant supply of life out in the open sea than near the land, and it will be noticed that diatoms were absent from territorial waters. There was a great difference in the amount of Copepoda in the two areas. Acartia cdausi was present im immense numbers offshore, while in Red Wharf Bay the number of this particular species was considerably reduced. On January 22nd one tow-netting was taken in Port Erin Bay, on the following day two were taken in Cardigan Bay by the steamer, and one by Capt. Jones in Carnarvon Bay. The tow-netting from Port Erin is not strictly comparable with the others, but is given to show the difference between the plankton from the Central area on one day, and that from close inshore in the Southern area on the next day. 144 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Near Port Patches Off Carnarvon Erin. Buoy. Llanon. Bay. Bidduilphia, ccc siadaseeane DOE ees. te 2 = yt ClehOCeros j ccaccsessecnceneee ab. 2. te Coscimnodiscus “tee.ce..ce eee ab — — — Fuhizosolenia, Se ayeccse eects r a —- _- Acanthometra: .....caese-eeee r — — — Ceratiamutripos a) eseeeeee fr ... if. ... ==) Sees Cera tim fustisiee-ee eae eee ff .. —= .. | =e Sagibta. cc avscncceeeceme comes fr. >... Gf 9 2..% ==. Tomopterissseecmeeeeeeee ese fr. ... ff. 2: qe Autoly Gus) tesasesecaeeee ae es . fr fr — ab iParacalamis: eas.caascee ens fr fr — ec PL GMMNOMA: Gavendoaeesdeeeeene — fr — e AMOMALOCELS) oxcc-ccneesss — — _ -- Centropages hamatus ... — ... Fr. oc | = = ee INCOM Ul ae thes ececee eae aaee c seh a Ce «== Oithona: 7} fasta. nsec acest ff. el = an Sa 1D (TU 6 O00 eenane ceee ca etensc cc i we = we SS ae Oikopleuras -osccscaecssesces fr 2. = «2. — ee IBIAICE COS Fe vecencemseccite — ..—4 Ac 2 a Post-larval Herring ......... ==) i abs se The plankton of Port Erin was very rich in Diatoms, and most of the other organisms mentioned were well represented. The inshore waters of the Southern area possessed quite a different plankton on the following day. Diatoms, with the exception of a few Biddulphia taken near the Patches Buoy, were absent, both in Cardigan and Carnarvon Bays. The Copepoda at the Patches Buoy were about as numerous as at Port Erin, but there was a slight difference in the species at the two places. Carnarvon Bay, again, was distinct from any of the other three, and had a very rich supply of Copepoda, but little else. The collection taken off Llanon was _ rather remarkable, as it only contained four plaice eggs. SEA-FISHERIES LABORATORY. 145 Tow-nettings taken in any area at intervals frequently show great changes in the pelagic organisms. This is illustrated in the two tables now given, which show the result from a gathering near the Liverpool N.W. Lightship and one in Red Wharf Bay, on January 31st. N.W. Light Ship. Red Wharf Bay. MGCP). .......0cecsasoosersensee ovens = = fr. ISOEODLACIIA ...5..0nceccccsevssocssces r — Bere MPR ciecic.c0is ot bee's ciecieciees sine es c ab. PMMA WAU tetas. 15s «ce Sseastenessocedeecesces 1 Se — DERE ELUM ass oieic/. Sloe « snis. o0.2 oa sivo.o ss seaisis rE — PE) DOSE co benesn eee eee eee r = DOMME a eoce. ccctstescveeteeseserses c v. ab. CALZICUOS, oso HOS ORC o eae O RCE ee oeeeee fr. c. IFSEMCOCAIANUS ...s..cceesceeercesccens fr. G, IPAEACALATNIS | 2 oo co-csc cele e's ses os a ceeenas es C. SUTIN ON Ee ee les Sa vise bass od bawd ba’emaree fr Cc: SCATGIa CLAUS 2.22 $12 vssso0s ovsase ets soa c C: Oithwona similis. ..........6cescsesecen es — Cc. IPIEKG® GEES, Geqsosiec ee tare cee renee Ereee 1 When these results are compared with those given for January 4th, it will be seen that Diatoms and Copepods were then fairly abundant in the open sea off the Lightship, but in Red Wharf Bay the former were absent altogether and Copepoda much scarcer. In the above examples a complete reversal is shown to have taken place in the course of twenty-seven days. Diatoms are absent from the open sea collection, and Copepoda much reduced in quantity. On the other hand, Diatoms have come into Red Wharf Bay, and Copepoda become very abundant. Such marked changes are often found, not only after intervals of time, but frequently in a very limited area, on the same day. On February Ist, four tow-nettings were taken along the coast of North Wales, between Red Wharf Bay and Rhyl, which show that L 146 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. although organisms may be widely distributed the relative abundance may change. The distance between Red Wharf Bay and Rhy! is about fifteen miles, and the following tables show the distribution :— Red Wharf Off Puffin Conway Bay. Island. Bay. Off Rhyl. Biddulphia > sssesssseesseeees 1 ee r Cosemodiseus “Recess. sees soe r. sen oe fr r Ceratium tripos ............ i es Sak ee ee Plenrolorachiaays-cesceceeeeee =e AE: eee r Nal bbe -ouscoste aa centecteetec r. sos) VW. BD 5.5! We eee Autolytus: Soeiesaescccecesce Tr: 2 = ee eee i “sMirtraiia, 22 sens tonantec cee re a =| aS eee Copepoda Vcccaedenss se. staeees ce wa AG ah Sle sone mes Calanus eich caoes _ — ¥: —_ Pseudocalanus ............ fr fr. fr. ir. iParacaltantise;..cccsossseses fr fr. fr. ir: DPOMOLAY es cossceeceece sec oawe fr fr. ir fr. AcarblaiClausiasesseecesseee fr sie ie. fr: Oithona similis ............ r te ie aT: MUbeD pina sees. ceccsceee ose ie r te ts Plaicereg os" eenssceareescadee — «see (0 so =| ae The collections taken in Red Wharf Bay and off Rhyl show that the plankton was practically the same at the two places. The intermediate stations, however, show important differences. At the extreme ends of this area Diatoms were rare, and only two genera were represented; Sagitta was also scarce. The plankton in the vicinity of Puffin Island and in Conway Bay contained one of the two genera of Diatoms only, but the increase in the number of specimens was quite conspicuous. Sagitta, on the other hand, constituted the bulk of the inter- mediate gatherings, and it is probable that a shoal had been passed through during these observations. This shoal appeared to be quite limited in width and depth, as SEA-FISHERIES LABORATORY. 147 only a few specimens were captured by the bottom tow- nets. It will be noticed, too, that only one plaice egg was taken along this fifteen mile line. The conditions prevailing in the open sea, off the North-East end of the Isle of Man, about the middle of February, are shown by the following three collections, taken in the vicinity of Bahama Bank on February 20th : — | (1) ys (3) OM UME ctr ecletaniniccis «nic anie.cie ova elens's GO. ay Ge de ab. PG LOPHETIS Foose cases caeces an eeeee —- — r. PAUHELONVAUDIS ates < aiclecis en's ssiniees smooe's's — 1 hah WOVE PON A cece ciccccenccevorsdseceeres C: e ) EMME eases sions stese's coince es fr. fr. ft. IESEHOGEALATIUS: . <6. a0 cv ener ens. ab ab. ab. IPARAEANAINUS) ce nicscccaseseresss ies fr. fr. WENGLOPAZES) 105 i0i. bs occiesieceisiones et r ts Pelle ELTON een niseycicje o's « oa lye' cies Es see 1s 15 AE ZOCAN tr eicta cele scinlsaie cnicce wave ese e — fas —_ © MEVEICE 1... 50.0050 ese vale e/a — side — 1 LELUGINIG) .nénoc Sat CO SEO ORE e eee eee — AAP — 1 IV ESSIS ERA Re celde baie vcctideddalenes — 12 — l TE EUPWAMES 2 o0i0c5 scene's scisineie one — ae — ] EC CMC OOS a acesca sven onesie rece ian’ Bibs" a hess ab. fr. HUOUNOGCICL OS! (ove c.sscssoecdeeeens Te ms Ts iD The differences in these are very slight, and show that the distribution was fairly uniform. The presence of the higher crustacea in the third haul, the reduction in quantity of Sagitta in the second haul, and the decrease in plaice eggs in the third haul are the only important features. ! On February 21st one tow-netting was taken in Red Wharf Bay and one in the open sea about twelve miles North-East from the bay. Considerable change in the collections is shown in the following list of organisms : — 148 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Red Wharf Bay. 12 Miles N.E. Biddulplita:? (Sec 7.4 ee eee ee eee c. wae ab. Coscimodiscus ese: -eee eee ie te ab. Ceraitiuim i USi Seen ee eee — r. Sagittae cect. sane eek ee —~ wake 6 IAMCOLY CUS) a.snturceccconer:oterace oe aecese -- a 2 Copepoda. cA crash ean esteem r r Calamus kite neqdaceeeeen teak aan et nace: ac r. Baracalanus ce acscnsietaocsccsoncces if I. INC AT UIA werecitannrscenacee seme Eee aoe its sae I. Oithonmay wAonicsc ee erect if eis rs IPIaICe EROS | eis sereaate eas cance coe -—— RS Fs Codueggs’ “Styosseticune cesta ca eee ie 600 — Haddockies usr. mses sercee ene r. ae — BiUDNe SS ico. seeaesacen asGscne eaten asee _ : r Rocldingiecosiesane- asec see it sce — The open sea contained more Diatoms than the territorial waters. A few Sagitta and Autolytus were present in the open sea, but entirely absent inshore. The eggs of plaice and bib were taken in the open sea only, and those of cod, haddock and rockling inshore. Two collections taken six miles apart in the area, sixteen miles W.N.W. of Piel, gave practically equal results on March 13th, but the constituents of the plankton were very different from what prevailed in the open sea off Red Wharf Bay two weeks before. (1) (2) Sagitta. -_t.celsce veeecue cnages ttocteeeieae « i i utoly tus) yo ee astee eer ee eee — Ts Copepodiay 727. joc csnsscceusmrmansececee et r if ACALUID . ii ccuccnrwmci ent octen deren Te i _. (Paracalanus' 2i4ia ieee ie dy: Te Plaiceieggs! \....cverwsmecttssiseteteee ab. ite ab. Blounder COGS. hor .cjcincdewe cenecneneeseeee ab. 2 ab. Da DCS O68, o's. cscs scissor xo sectavan tae leeeereee ab ab SEA-FISHERIES LABORATORY. 149 On March 20th tow-nettings were taken in territorial waters off New Quay Head, in Carnarvon Bay, near Duddon Buoy, and in the open sea fifteen miles West from the entrance to the Duddon. These throw light on the conditions in the territorial waters at the extreme limits of the district, and also enable a comparison to be made between the open sea and inshore waters at the North end of the area. Off New Carnarvon Duddon 15 Miles Quay. Bay. Buoy. W. from Duddon. WOSCMMOGISCUS —..c..cecseces ese r — a PAGING Bese s cess nee cnene — r — ee SE OMU AMEE esc iar science ce eenes SS ee Ee Ce wails eters gale PTD OUTER: crcictoire ioe osic ss vesnce ss 16 r — = DEMEZOCAM eens sasece es vnsc vee Gh 5 la ee Be aI Nauplii of barnacles......... CH Me (VAUD iy 2 te Ostracod stage of barnacles... — ... r. ee) a ee DOVE MOOM care ccccocne ss. sic cess 185 ee ens 18 r CHIGINS <6c)seaat one eee eas ee iP r IBAEACAIATIUS” 5.02.00. 00 0000000. — — 1b r ANC TIN OU oo cists Faisisais sv ede one's — r iP r PMC AUR aia ieee evade scess i aie le F. r EATICEMC DOS Gyelsecnsacceess.ceeseo Ee, Se ri r LOUMGET COS” ....- csc. se osees — ee if r IOC SOR ee eviny cca deenoccence cc — ee 1 r \NVLLIE ado abi ahsret oa Te r TED c0Gqc OREO EDOEEE ECE Cee ee ee ee abisae ¢ Te is RNIN OR acces casioviccealer eesti ab if if r Diatoms and barnacle larve were present in Carnarvon Bay only. Copepoda were very scarce at all the stations, but a noticeable difference in variety of species is obvious at the northern area. ‘The eggs of whiting and rockling occurred in all the four collections, but were more numerous off New Quay than in the others. Plaice and bib were present at the North and South extremities, cod and flounder at the North end only. The open sea plankton was the same as that found inshore. 150 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Two collections were taken near Duddon Buoy on March 31st, within three miles of each other, and although they gave similar results so far as variety of the constituents go, showed great difference in relative abundance of Diatoms and Sagitta. Duddon 3 Miles N.W. Buoy. from the Buoy. Bid@ullphia’ isch ssacsaeaseneaceceeiectoee Vi ab.- sete G: Chee toceros' is...cdtonscucaeeseieectneesenes r. ie WOSCINOdISCUS Moc ssck. coomeetenae deere v. ab. C. Rht7ZOSoOlenia, .cisesnccemsaaces seceeeea ee rE ea Ceratium Str pOS-recee.- er sseeeseaocaaer fr. F CeratiumlPUSUS —2c.eimcacsaeesioneciewcce emer fr. r. AMO (OvMNLIN CS se soqcpsngnooecoN00N 185 E Satta cesacdocseseeeteeoraese- Ge eeenne r. v. ab. Mur ydice ., cas semnesedtereenocee socom: i i, Copepoda: ccasscacteanenemacecsasceenee ace c c. PseudocalamuSa.<.ssaccssnene-seeh one fr ir: Paracalanus .g.ds-ceecnoseeneek eae es fr fr. WPOMIOLA: c's nate cide e none eoisemsccsiences r r: ACartia | pccstutacecs aeateacen eee fr fr. TAB IIGS) GIs 54 8ocdcancacongndandgscadndaoses r — Bibi Ges wits. ccs aces suioneeeteaneacceeene if rr It will be seen that there was a greater abundance of Diatoms, chiefly Biddulphia and Coscinodiscus, near the buoy than further off, and also that Sagztta were more _ plentiful three miles away from the buoy than close to it. A comparison of these two collections with the one taken close to Duddon Buoy on March 20th, shows a very marked change. Eleven days before these later ones were secured no Diatoms at all were present, and yet, in the course of a short period, they have made their appearance in large numbers. On April 24th three tow-nettings were taken near the Morecambe Bay Lightship, within an area of about six miles. The results are almost identical, and it is evident SHEA-FISHERIES LABORATORY. 151 that the constituents were fairly uniformly diffused at this place at the time the samples were taken. (1) (2) (3) 157C 1G nl) Ce yee ee eee Deb Pas. ab. ab. PGSCINGDISCUS. Lo -nijscedeesescs sees Bis ia piece ab. ab. EVENZOSOLCWIA 5 2,sarcec esc ecsesseee os Opie ees ab. ab. CWerabinMa TEIPOS! 2. :...0... 000.08 C C: c. Cera THSUS: ...35.2...c50s0000e C ce c. PMG VOWIUNE CLES 2. .....ccescsccees ig r. pel DN EPR oe erstao tds cine d Gain oy 00k a se ee — — Te PMMA WL TES Ree coin a6 diisiasaeicisieie ee sia bose r Ee TE: WOTANRZOCAIE cco dose sce ede dancevdea dees r. ie ps RRO Mae os xa cisis oe slots oeeie.oisss us Te ©; PRIN Me fo ise fn Secs o's Sse Guinea ve r if ©: PALACHIAMUS cioasee cise oe mseree es r Te Tr. Pete HALTER eres crac siecle acla'ss's vo dee’ r 1 c PNSCIONATNC SOS! | cass eceue Sen ceces C G. G MOP CUA Sescscscsaccocsesedecans i aie iy su 1 ERC OOS ed eee oe cic es dean sieaiee's Wen Se taece | “VEdIDGh sce + Vea: PUTO OEIS COIS... ees oneesececse ns VEO) Se Na Ved Due osc ava: VOLT Ce a ee WEDD Eg ioe el WeaDES) cen Vea RRC OD SET cet c cols css ei ce's swede ne's WDOevcee MVEA Since | Weal. Collections taken at the North end of Cardigan Bay, on April 27th, show considerable variation in the constituents of the plankton, as will be seen from the following tables :— Tremadoc Off Off Kilan Bay Lianbedrog. Head. PO ANATA S| 250 ces coca sccseeseds — — 135 OMEPEOCCEOS, secesestseuvescerccceess i ae — WOSCMOGISCUS, -..ccesecsscscccesenee ab. — i AUZGSOLCTIA scion cannes ce seeee ip. _ — PMIGVOUMIUI CEOS. ....0csereedecees ie, — — SEOUL EE Bar tales oi oiesin's 225 vciio- seid naien Te Te 1 AEP CD veces secs es nae voissacinvine _ ae it Nauplii of barnacles............. — ce G Ostracod stage of barnacles...... eG Cc C. OMCOO an cccsoccsccocsessscitaseens Ge. G re IPSCUGOCAIANUS ......02ssc.cccees — nis — BEEN rads 8s Se 50s piepisisinidlo'.s set's fr. fr. — BEWELOPAGES <6... c.cccscneseneeeee fr. it — RE TRENL I.0/slddvicindcaisjedeoncedess oe fr. fr. tr. BROS a cccsics's ov'eiceiclens ssiio'aejoo es up C. —— LULL G2 ee ee — a ip EEAGMOCISNCOES 0... s.cseerscccese ss — = r. MPEERE RCL OS rca cscce acs scecssetes + = r. gs SHPEDICO OST ce tcscsccneesesecct anes r i r. RUOU MMO CR ESM oes. cecescsesereces — r. Be Spotted Dragonet eggs............ — is --: 152 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Diatoms, especially Coscinodiscus, were plentiful in Tremadoc Bay, absent altogether off Llanbedrog, and very scarce off Kilan Head. Copepoda, though common in Tremadoc Bay and off Llanbedrog, were nearly absent at Kilan Head. At the latter place only one species, Acartia, was detected. Fish eggs were very unevenly distributed, and out of a total of six different kinds present in the northern portion of Cardigan Bay only one was represented in Tremadoc Bay. On May 7th, three collections were again taken near Morecambe Bay Lightship. The first were taken close to the ship, the second five miles West, and the third eight miles West from it. The plankton was identical in these samples. biddulphian Se-.cse ee ccoadee eee ies oe Te weg r. Coscinodiscus. | +354.. eis cc ccd We ereceosenaceatentess r I re Ostracod stage of barnacles...... e c c: Copepoda awe ecscceedecosseenaeos seme oF C C. Pseudocalanus = 5--ee esses fr. das i fr. PMOL. 4. co. ceceesneensckieceee cena aT r MPOYMOLA:” sideccsceicecies sits ce eeeee seers 1 c Centropages .. cc ..-cc.seseessme-ese sass — c Anonialocera.. 2. o asie.aa.s ie r BABI REO SY reel stclasidlaasiiaiesin's @ anlt.caiad oseieo-o it, oe r ROR ANTI CO CS) ners sae ncewncite oceaee ve ity Bree _ Hommon Dragonet ..........0:0.0.0c06 tr mes r Diatoms and Copepoda had a uniform distribution in these areas at this time, but the other organisms mentioned were evidently limited to Port Erin Bay. A few days later considerable variation was found in the plankton in Port Erin Bay and its immediate neighbourhood. On April 9th one sample was collected 164 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. in Port Erin Bay, and another just outside the seaward hmit of this bay. Port Erin Outside Port Bay. Erin Bay. Bicglpla: ~ cee. cea cvesssscae- cere ab. eed E; CHetOCELOS Abicost4avcedaenteveesoenaeter & se — WOSCIMNOGISCUS — «c.cecessssapchlnaeree ae v.ab. ue fee UGIZOSOLEMIA:. | /..<< siccevescceisemack seme aes r -- CeratiumMiatEtpOS= —.scsceeeeeo eens r = Ceratiuma LUSUS' ssi. sc sceeceremeaeeene 13 a --- SSA OUG bac ccs eves ten ccisne sotoomaemoene setae r ¢ Naupli of barnacles. “sr--.-caesasas: ff - Oopepodars. drndesunnetesasosnceeseree c ab. @alaNUS, cassiic/ccceslac aes scouas egemeres — fr. Pseudocalamus cov.ccsmecccccneseensees fr eC MOMOPE “az neid'seetess see cioseeetassoestac fr ses ce Centropages che aanaretedeeeacessee Te at. iin: INCE LL Dss Sint wctcleactaie toate case enan eee binge ot ©, Ott MON a wcpaccevcewnk ondaceoedeaneeeeeee fr. si fr. hens: Rough Wabecesie snc. ce.vadses- = a is Solemettereg es, \icins saesee-camcenctrace: fr. si — WV UMGITTONC OOS, pt cocosscien Me ere nece mentee — iF EMAC RO OSE A Rablewsde ane canna cteaee dere aes — one ig SLAG COS vee sc scot coeuitoeiaasicsonsser — af. i LOGIN OSES OS, Foe acncbcesn senten see ica a r On this occasion Diatoms were confined practically to Port Erin Bay. Their relative abundance was the same as three days previously, and it will be noticed that a few Rhizosolenta were now found. Outside the limits of the bay we find an almost entire absence of Diatoms. One or two Biddulphia and Coscinodiscus were all that represented this important class of plankton. The Copepoda in the bay appeared to be fairly stationary, but out in the open sea they seemed to be increasing in quantity when compared with the sample taken off the Calf Island a few days before. Sagztta had also become tolerably common in the open, but still remained very scarce inside, SEA-FISHERIES LABORATORY. 165 On August 24th collections of the open sea and inshore plankton were again taken. The open sea sample was collected three miles West of Bradda Head, and the shore one off Fleshwick. The latter place is about five miles due East from the former. 3 Miles West of Bradda Head. Off Fleshwick. Ole LOCEROSIR Ne is edienncieennsueene vended tees r. 1 CSCAEMUMMETIPOS: . css csscseccoesssvuesee iN. ap c. NS fovee cM Odes obi inac vice? visdie seeae dies ceo’ —_ ie IDIOM PPE er Sainhacc oo: ci te cadaca.coeosees — I LP OGIO. coscd Ma enon CHCA aoe oe Ear ane — I PEAOMAOC AM Mee ocicsacenn.gsereedvosss G40 es i r Crab megalopa ............ are aWe ye r. aoe -- OOOSOOGIA So aee NARA e earner ener ae ah. te ab. ISCUGCOCAIATIUIS, Sasccseccescccceeeessee = a fr, HAC A ATANS: 4.0. /c css di evigies aed oeevaus'ecc’ @ c Bh TINO MMe eee ee eas sicisrcmeie a scnee be — Ie PMITOMUALOCELA: sassy sev vais se siceis vibe so seesis r = Bara WOMbellay <4 shies sa csaess nce soo sae’s r _- LUST. o doce Ban USAR SC OSE EERE eae fr ie EXOD)” RENO BOERS CEOS eee EEE fr fi MGMOM Bea ce wee hccoenls aanits venevnes (o; oe @- CLEC [DIK TE eerie eta oer ir a ie DE CMETICOOS a Set ch odaies onainie cls cae viet ov.0t iL ios ~- Quantity of Material ............ 3) Cis Nee 5) GAO The most noteworthy difference between these two samples is in the quantity taken. The plankton inshore was evidently more abundant than in the open sea. There was also a slight change in the variety of organisms captured at the two places. Copepoda were just as numerous at the one station as at the other. Anomalocera and Parapontella were noted in the open sea but not inshore, while Pseudocalanus and Temora were found inshore only. 166 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Inshore collections were taken on August 28th off Niarbyl and between Peel and Jurby, at a distance of about seven miles apart, and gave the following results : — Between Off Niarbyl. Peel and Jurby. Chetoceros feet ete ee ae fr. © Ceratiumitripos)y pesscesaeeeetee see eee iil G Autoly Gus. cc .cscqne erect css es a Ty Crab 20a. ccc aeesaeneencus teeters ie Crabsmevalopaseamssseeee seeeee teeter -—- ‘s POGOD:. « acteeruac-an ee ete ececon cee r — Hivadness.cccces sees ree aesare eee eee 8 — Copepodas 22 a. ticncen cnet reece c c Calamus: <5 jus. c0Ot sens. cearecenaneee r Cs Pseudocalamus 2:2. q.c -¢ ssaceononseee fe — Paracalanus: «3.7, stemepwesmcmoesens ts r i Memora ccincaes osSeortousen ven teences see r — Centropages r i WSIASS cevepclscandespens dathtucmeneeee erocee rc — ACETHA) nv decoscasteee semedeemueers ibe aii fr. Outhonma yy cu.bee.c.acume ener re cemee ae c. a G, Oikopleura: ts... Sixx cc Meponectre ty mesete i, sted Ds Mackerel esgs': \. sn: gccnsosesccecmeeen se i abe — Rockling egos) ssa aee ae eae e ah 1 Quantity of Material ............ 3 €.C. 36 13 c.c. These collections again show considerable variation in quantity of plankton at different places on the same day. Diatoms were more numerous off Peel than at Niarbyl, the other organisms also showed corresponding changes in distribution at the two stations. On September Ist a sample of the plankton in the open sea four miles West of Bradda Head was taken, and also an inshore one off Niarbyl. The latter is about eight ~ miles Hast-North-Hast from the former station. SEA-FISHERIES LABORATORY. 167 4 Miles West of Bradda Head. Off Niarby]l. ‘CIDTEHOGRIEOS: Mateos she Be enon Rasa aeeeE anon ibe. r CeratAMMMGELPOS! “c..500..20.00-ceerea cece. ire 6 SAYS 2 ge R ba coseebode GEOD Dae Cone eaee ame — r PM GM AA Me ier asc) spies Seine cine once _ r Se MBAG CAE EG: cau iio oone- ==) hee a eee ee | caee|osisiee eller ee call eee Eee eee oe nee sje'eiaie oll «:n:eioiera|{ ave (sieve | efateieieveilove sio16 o/lejajele/alel|=iniete lel etetaisiet) | eheteteatel| etait aaa RP oc =F ar =l=Wleseleioie «|| o1o10je1010)| e(eiolerajol|jo.e/eie{e/e]| e/etotelsfol|otelslateret| eleletsiets|| cketstetetet | Miettinen ae ate ap lbkoosec SF |laccona|loo000e|bo000¢ ta wcisin [a oss oie oi/ut osteo ar |boovoe Es =e a2) |Sonovsloandenlbocedc Bp Dordne|basncc = Gideon ofertas + | + | 4 | Hf [nceeclecnecc[ecsees!

| Soeaae| ene ste Bla setae [Reyer | tee. ciel h etetee| Pt, ttre Secceinss (yaixslen Burerpina acutifrons ......|......|...0..[essee Se Sear td GeBSse HaoAgEl Spader secre secune Mecae aiAaeen TUT rec cuecccc.|se.ece|seceee|seceee ef (eects Pa [peectotar lee ciliate estes PR, Wee aletat a's Len ata PIO TNOAIIACIOS 5.22/00 ccs. |pcccsa|-scacs|escereloceess = foun lptaseatal |e eeeererell ese (atic asczel Mareieeinijo sen 'e HE Shoe ieee eo a ake a ea aes al eee ae SS Elion eee ah cot Ad ed set Da sarais aid Pacemeltumectl|-cenealtetesn sass «liv sac RENT Free |bie nia) once. |asadenleceeet leaves sloenese|saseesleoveccleceess[eosees|eccers MEE ATCIUOEAMICHS:, 5.50). ....] cc0c.| cececlsececcleccasslsceees|recdcelecoeee 2 ae | oe an ae eect RIM ar ends Nei siatec|vcc-celcoess| voces SRN ae lair onan bisccce = cial Serra tain eine te ric. lbnoe | 6 svec lesen se|scenns[peceec|eeccer|soeene[ceaereleecess STERN [Sonsc aye Port Erin. eeveseleon eorvecevelee eoceoslen eeceesion eoceosloe eoscesloe eoseceelee eoceeslee eoseerlen ewww enlen seeeeelee seeeeelee cr) were eeline seeeerlion 178 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY March. Eeeeise | 2 ab D2 a=|) Cea Sy rs) : 1a 8 8 S o @ ® ® i : ¢ (S28) 22/52) bel Selas| Pe eo) Ss] 2a oe @ \fa|2e|ee|Sa|Sal\ea|ou|oz|62/a8| a| & | a PNGUELONE a lO Ae VT: ‘eydcere| = 8 com alle erence ls ee cee lee etells Mees lee veltellee eee oe eee “| eee len sarseilee nnstel ean ae Bellerochoe malleus ......... “T Jemesee|scsenis|aeeree lessees |siverieelosisiaesilerscte «le p:eee|- epee eee aaa aan Bid lulphia mobiliensis...... ae | Seeaelsenee: a} te «I eeeraaroeafornree oilers ote “+ Seow]: ete ++ locale Biddulphia aurita ......... Tradl emacs lena ++ |. ccceefeceeweleseeeele oneisies ecien leieeleleeteeee keine ChetOcerOs COMTOFEUM (io. .|....060]. sce oc|enseso|eoneee|snses0|n cme siler oe aeile ce aeileeeecle eee an aan Ce Chieetoceros CeCIPIENS 6.2.00). soe ec|eocees|eecore|eoeees|ee seine led os 0leseec]ee een) steel ae ie a a CoOseiNnodISCUS CONCINNUS .<|...00-|-s0re|, 6 cies 5 fF fevscee[roceeeles ence [pe cee eleietiee] eeldelste|etetteietel en== i MedusotdyconGplOnes te sacn|-resen|-s 7. ncl+sscre|eesetleenelseemee|) weeen\smeeae “| vowees les cerelemeee + |...oa Mer OMMUMM COTS ae ee ee Se See ee Bee VIN Gerla: © Sox ccamemens tener ICeBeicte||- tsa +. cues selec Sn (ce ie Cees Pee Pesce ei soceac|.sccee!s. 3. -- See OA ZOCAN a coer meee teed Phiieis.o.e'| cteeme | arose clerewrescilclerow ot I eee: ia + |. .eseclooene aaa +). Mysis stage of Crangon ...| + |......|...... Spe Necaoe + |.weseeleceeweleresce|occe ee /ecces oasis inn Bury dice spuUlelban ieacctwe |. 00000 |-ni08 2s |emenar ETE ceteteatl | feleohe eliedyadal| ersorem “+ |e ceeee |e cneie)fne ee ee) ele Bath yPOreia PelaGicar .. 2.2... eelsseceo|eccses be leseceeleccsee lowes celeeees |e cse oe lein'ee.sinle ciee)siel tele in PSHIMPCLISEASPUMIPES, 5:5. oe.« of -(elsoiallsincieiel rien sb. ]occeeclaeenos[oecwie [ensce|ee ve celeienne cle sletela ie ats FEOMELUSA DISPIMOSA, ....:!..a<\|sievseal-ioev se learece F- |osesncleccece|ewenee[eeeses|oeeeoe|s e000 |m cian na) iaieeta tei Perioculodes longimanus ...|......]......|....4. st |aecees lessees |e nvces|eoeses[oeeeeele sowne lucene] atime aii Phoxocephalus TUlEOML . 2...) se ce.cl-meees|-eeeey “fH lasers as SSveatein| fore es | are sree lesepeciets (eee ee Wc IROGOMIMberMIE CCUM « ..46+<<<|.o¥ xe|-teviee|-loccver|ls metcieleeincer “fe I cine sll ereree'e|fateine oo [oie cesete Aenea |. oe -eeee a Calamus Welle olam deus vee a2... |. tere sollte «cs sterre bral oe oe ora seers | eee | telesters [eres 5 RM Peoee one le heen + lean Pseudocalanus elongatus | + |......|...... Fle), lNsseetecs ste il Asetere | eeecrae =| | wareleeeeee | ate + lease PAEACAAMUS PALWUS. octcoleiis oi\ oleiceioail decal eects af Yel Beta | otoa deseee + |. cee saa eee + |. comm eniora lONSICOMNIS:.2. «60. sn\.eecesleeces|eeoene ste 7) peaks Rete trol etctter + | esos o/epapiee eae + |e Wemiro pages WaneabUs’ of acl tases ellcteicntool eestor ate Nseeae fo BS Fa Sil dorasiein + |e es iecel ecole ee + laeseal PNCAT UIA CLAUS act osco de see decease cael sees +/+ ] + [...... +.” |... cole see eee + | weet Dyrettora paints) 2.00 -0.- easel bece-|hesee| eau: Aol roku teelenc ale cot: |.teee oe Beek: + UGIMOM AMAA sche cisic aw o's ve [le weiepslf oberon ote) cheow vate life ante [ctster tell Herat aesell Meters | cheralsta [atebtoteh | te eter aa lide: + |. . ecm ST IGGIS Vel A MEN Ne cere eslons estes | areeaia|| elena feleatae stool Actoaies ate 1| forestall eiaek = lems eee |, oy alt seen . DWGpe pod MAPA Poncgedecews| Ost || deste enllelvnen| deasrte afar Sato al Arenas | teeeje = =F |e occ calle Raper. 4- |ooeum Nand of barmacles 2.6.20 ste | ae cwleie| ae valsi|ate corse Sa ee See PRP PRORRAPRSO | occcoo + |. Ostracod stage of barnacles| + |......|......|....6. = [ob |eewees [eves ce|scceeslenacee leanne -+ ]. aaa MUIGO DISUTD insterawe vei cow eae oss el Saleeieid| Qoicterwell AoieNe stra lerccer el ieee + |.ovsse]s shale + |. c0am FABRIC AMINED OS 9 veissereview sedieinsrarcl|Ot- | | datsietec'| are eters ats Sea seen Nae sles + |. eees|enesee «ism ien ena an YOUNG GasverOpOds °. 0.40 coll soci eeicetl|ciotels orl gem eae |More Tt liesceelessees|eccesoleceonelels da sls isis aii IBNSIMG ROG aa. ovens qsixss'etmeore| wrtsu ldeetele| estate Sheil ie ata] ical ee ne ++ |. ..0ssleemee ae +. lasso IBIS EIAVE Wer cea iain « a0 oivie.s-odsieate cl ste gucci newer aeie ees lal gneeies tll eaivearell Sacer “+ |...000|eeusv tonal ] emia — | 25 | 11 | 22 | — 23 | — — | — | 27 | — SEA-FISHERIES LABORATORY, Blackpool. Asterionella bleakleyi Biddulphia mobiliensis Chzetoceros contortum Cheetoceros criophilum Cheetoceros decipiens Cheetoceros teres Coscinodiscus concinnus Rhizosolenia semispina Rhizosolenia setigera ......|...... Rhizosolenia shrubsolei Thalassiothrix curvata Ceratium furca Ceratium fusus Ceratium tripos EMGAMPMOMVELED SP....-....0.00\eerees Aleyonium eggs Sagitta bipunctata Autolytus prolifer Larval Polychaeta * Mitraria ” MIMBO te erate cclosuis|oases. BEPC SALODA 2.0. .nccceeees|ecsees Mysis stage of Crangon Pasiphea sivado Wmeyaice pulchra ............|...... Eudorella truncatula eeoeeel| cess wool sccsee ecolrcesee eoelecesce eeoeee|eooree fees coresesce|ssrssece eeolececce eceleeceae eoolrcccce eeolsocrce ee ereecesoevercelsecorse fe oeees ser eoeeolsecosces eter ees oveselesoose eeceesse oot ealseoeece e@eervoeeeelssosee eeeseecerdvel|essece Seer eseselecesce Seer sere aeeoreeseoi|soosen eerleeseve ee ese er cee sels oveve eeeseelesovece Calanus helgolandicus Pseudocalanus elongatus Paracalanus parvus j@emiora longicornis .........|...... Centropages hamatus Acartia clausi Peer eosresleceves Oithona nana Copepod nauplii Nauplii of barnacles Ostracod stage of barnacles Oikopleura Ascidian eggs Fish eggs Fish larvee | | MiroOma: SIMIIS .........2..00-|.c... ee ee ee e April. Gop OF ag ae alee e o# Pe Su E 1a @| Os tm 3 23/25)/R8] ee 2e\|on| ao) #e 2g (Se) ee) oa i Leal aca meas ae Mereeeel lobe vec ltectoce HL Rae Reed te ieee aL, 6 Pe Oe oe ee tet eA sale Se Bee ate Sh nee iPr tieg ta inane ig > Be Pee nee He en a ee eae a S| eee a ae ad | aE aa) | | | Sore alae 5 2 |@ [2 |# é abe ee eet le le io esl | ee EEL o re | | OT | AN | | ae g Hel|Se\H#olH#olud|/aal] 8 OM l|eAM | O44 \o4|/o4 | Aa) 4 Stout Werpeeioersi| cvelerorsileceunresens slat hl casvertersileseisisls:s te fldetesias hee lle rcratete fee il eee steveiliederets See eed aisisvellteainarets = leMalfebeteroratt lose trim ioveveteronallistetei ene.’ pebveatllniatccrer: a= lbccoosll ap. llossosdloosoos Mereeieiloengeties Ftrtni wrcrestaraalie octal lateatavellecienss ce Srolaverece ler chetens’e =H. vere ay aveilisvayaie rel liter saver llereie wrote Bites sell ches nes tea (erste ever Mencia erate evs si| erexejere 6 eee nernlleteicers eal |sveteyavarel|), cate alletetererstel ersteeteve sioterctse [bretsiee feet lisatevarere | sete cll sietare: aisllfesevcraya' Stee lllevalesiecs Heol erarecaotei ics sratetrstelliscs aveell ereteiovers tata tele ee eae Se | Seles te Pon ctaye ol aaeal Wey Mil or c'sPers lupe aarers ls craze aielllsvers cooterl eae ake boots marae fete | Beate crarel| a yeu | ecterecavel ltrs ateers Paes ocilcrereeeee =f Il etecerarevall Grctetave:clleveieveteael larecaiecere ats ones. svaianerscs Trae H eteuatoveter IMGensiazevelllovetershenel etecoracses Seraierel eerennne = {oer staavevel ltceierefotelll ‘eie/ state |sreveorere slay | neetare||eeyateretel lta ott all ctelsioiseolleisicleis -ilvsiew 7s yates atelllerareictewe [cara llotateroreteillsversievevel| erevaerensil siewerete'e eave aber [esateresers celal etevs te avall chev sloiavslllsrareiezsrel|/sverecsiers eae: seus lisveyrcvanel eeetatetstal |etetsloiess =e’. lecorsieie'ei|e valeceus ae eee ma eal ea sscreteil Rint icietss|epatsiave' fecorsse = « is a siei| eae ass Se vibbmecel mo lease itaenod ae alte tenes toil Bercrercee S[evuletetetaretel| ayeleiesere ah illerat avarevall rakaeserel lakecaaeevelleteralserslllererermsetellaveve-arss fe eva avert om llonosao losin siatetell sie.cie.e- 6 Ee a ee frankie ae eckooae eatin le seyeretarel late. sien ove SST Alls eat alisitichcss| Grins aA EDnG eaaoae Saeace Ele | eed ate cars| Mererateasl |Seeroieselle erst vell sresaiere | eleiec eve AGREES SBE Ce SP |oagoacl] ae |booons|baacoo meieavenil as atorete Ae locooaol| “ae Ianodealloocnée ST RR tote at NER siete StS [Etas cracalerine © 9 14 | — | 24; — | 18 | — | — 179 Port Erin. Luce Bay. eoveecelsesoee eeceeve eesece eecece eecceesl|eccece eeecos eocecece eeoese eovsee eovceesl|eeeere ecceerleorsere eosceeleoocere eooeerleceeee weoeeeleoseee eevee eereee eeeeee eoeere eeeeee eeeeee eeeeee Ce ee eeeeerlereere 180 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. May. es ee: g(a |4 : De n PR D = rc : (eels arate © © 2 ¥ 5 Ba Bl ofleelecl(& | |2 |8.18 |8.|8.] 4] @ |e A| a ® = i os) aa 5p =alosa| sa ae is ica} s |25/s5|25| 62/3) 28|aclaclec|as| 21 B | 8 mH |2e|Sa|m2|Sa|Salam|oz|oa|oz\aal A] a |a Asterionella bleakleyi .-.... fe |oecesuleeseselaeccee|scconslaccsceleccone lee susie loatwienlldaeaall tase eta Biddulphia mobiliensis .... + | + | + | + | + |......]...... Bw etre pecdac|ooccs- |a seer [| eae CheetoCeros CONtOrtUM ..... [2.5.00 |e.2e0|scnede lees ss]escnes lecetiee| scene |: ean) cette Seeeee eee iene ec - Chestoceros criophilum ....|..2..c]<00..|peeeee|secoed|sesecs|eeneosleanses|eceee|- +e al) eee ee ar sae ecrs-- CHetOCerOs: dECIPIEMS ose colo seee| ee ooice|se see |cceee s|nemwee|seoe ol ocimee|e cone s/s ceoe Oeee ea “+ | ene | ChetOCerOs LELES “secc.cc connate ee Cerapium fUSUS: <.c.-..0.25-6 Ap St ee Ee, cletllaalge eal sawed 5 ee ee Se Boece “+ lence cele eee CeratiuE tPOS) ..5-6---n-- 7 a Ae ee al emt | ee =P [Seemed SSN Poe Bese “Flee soe Noctiluca miliaris ............ oo Gace seo Takes alktegstsierl oasis erel moments |. eeees|eesees [ere cstecl|ee cats] s seat a aan Pleurobrachia pileus_...... + se Mae lscees + | + | + [ee sec clae ceo) eee Se SESIa UUMOUNOSA ces eeye te asteges|| se oealede neice nolo nes aalacmene + |b |e eceeleceee]eccne cleats estes te Medusoid gonophores ......|...... ef. sl aamalloc abou eateredl seeeiie =f" \sealletomeiee 4b Coenea lean + |i -saee Aleyonium eggs ............ Se Ps al WR i eos egacioc SE |bcccee a Bie Pee Socoue) boc sco docs -- + sen Sagitta bipunctata ......... op) rears lear. lesccs: HE amo iieam [besos oF |. seats flee See ote - ENUbOhyibUSaPEOULEL: Monies ems oe] ows oral vara eee Spe oe, cate Oe Areas Stee Se eee ASE = ee bene Lene ayol hie ae ee # Shespeae eco] heseos bosons brenes ae ore sill tolasieal oka |-seeee|sesetetaesnen/nat sets alee tia BMG ATT Geet ler ciciesiss'ers seis eincie|| «6 ee:610 Pe al enetecta BE eres a Ne awdwrellerencerdleeuees + |. .secnlfe ssn etaeee WEA DV ZOCA ceacaccmicise-ods one oe'leceoas oe ee a a (ea a eel cian Se Reeene: + |. « -teilacel| woteleore| teeters sb. |e eeceleseeceleeeees [oe cn |= snlelaeeate eaen— n PNCALELA CLAUSIsce2..- 5 rene «lowes ool na re “+ fos ea OIC UMA irene cleies 06 uenes ct |) pater MMe oe eee ce ee oe Ole eer ol SAG ol Ree | oe eee + |... NSCIGIATIICS IS, vane snciewe ooaee SE | Ty RHE oaereearal leteitatera!| otal ettn cll terete: eae | fatale + |...6+-|-0 ses |ss ee Young Gasteropods ......... |: cates» datesel| secon feraetgere hateer eee lnetecsleciceen|>cceeec|- | SEA-FISHERIES LABORATORY. June. fo) e ° 8 ek | Be o |/25/2%58 ham |] Gaz 8 (4h |=h Eraduipnia mobiliensis, ...|......|......|.c..+ SOO AWETGA ~~ 2.22... |. .c0e[eseeee|-ceees DEGOPCLOSIGECIPICNS 2: ....]......|.5.00|eeese. BieamipiayZOOCIAcUS ......|......|......|.....: BME TPOIOLECEN 90... ..c05e- lec ec en lececeeleceees inizosolenia Semispina ...)......|......|e..06 Bivnizosolenia Setigera ......|......|sc.ecs[ecsees eNO MISTS a ccs ccc coes|eceneslesenee|e scene Be ANEEOS eee. cs cs.e-|eocees{esscen|soaees MPM AMUIATIS 2.5. ...2 2.06). . 0.00 |esevee lessees Pleurobrachia pileus ......|...... aon ae ote meausoid eonophores .:....|......|..<...|...0- 778s, 1 CCSD SAE SA eee Oe i etmmoceray LarVvee..... 6.2... |......lesereslecsees Sagitta bipunctata .........|...... a tetalecenes BM UUSUDPONTCT —.......0.|. 2000. [ocenec[eaeees —LLIE Te) ee afr i|as eee 08 7 8G8 2 a aot lakes SrA MePAlOPA ..........:..2-|s.000- + |eeeeee Mysis stage of Crangon ...|...... = Sl eee ae Bee OmmMtermiedium ........:|......|....0.[se0e0. Evadne nordmanni .........|...... aes llne' tie Calanus helgolandicus ......|......|......|...... Pseudocalanus elongatus |......)......]...... -Paracalanus parvus .........|...... si lee yeite Temora longicornis .........|...... elon londicte Centropages hamatus ......|......)......[..006. Cemmropaces typicus.........|......|......|...... Anomalocera pattersoni ...|...... = Sa eee Labidocera wollastoni ....../...... stem bushes MPTRUIN CIANIS..ceccc. seen. scecs|...0. tis! [alsiga'e Peariia Giscaudata .........|......|......|-..00 MPM SUMTIUIES goes. cee eesc...|.+1..-.|os000s|ecees Sopepod nauplii ............|...... ar Petree Nauplii of barnacles ....../...... =e ee Ostracod stage of barnacles|...... aa eae 0 ai Ane MINI Poteet esc. .|,.s..'.|.0.02-|..000s moung Gasteropods .........|......|:.....|....+. Young Lamellibranchs......|......|......]...... a EE cee ee fee lealebs BU ss sect cacssccvcsses|evecee tes tows Rhyl to Read Wharf Bay. Carnarvon ceeceelecceee eeccecleocece ee eeeelseeeee se cceelecceee seccceleesees ce ceceleceees seeece seeeee seeeee seeeee seeees cece eeleereee sereeeleecees se ceeeleevoee Jeeceeeloeveee| seccee eeeeee jee eeeeleeccee teeeee Jeeveeeleeveee sereeeleoeves cece ee leecene se eeee seer ee lee cece er se eeee seeeeelreseee le eceee seer ee leeeeee |e eeeee se neee steers le eeeee se eeeeleoesee se ee ee leesees te ereelseseee te eeee terse leeeeee se eeeeleseeee terse eleerees seeeee sere eela eee ee gq ie & a SSeS aa | 2a OM | A =a: Tile erevets =e vitareveree ae hee ste I spoke fe) Reais + aicreers -- ae ante, + | + =: | + fe tae 4¢ | = = el AG = a PAE zh bea 4 | 4p | 4 4p | ae 42 | +e 4 | ae 4b ae tee Ne eles eis ere met lee ares aus ==" il ssetejeters + | + =o). later etole abe le yavelarete Rao qe ae ae | ar Off Shore Stn. No. 1. eecece eoseee eeceee eeceee eeceee eeceee eeceee sfersicrons lodooon goood acdagon Sieveleyeus o0d000 ls00d08 S000 aa le ahs lGacoce sie Saves sia coteere ee) Siero araverevers ae siewehs Lievetetere 500600 seetatelors ee enee je eens se ceee ee eee eeceees eeeeee sewn eeseee se eeee je eeeee eeeeee eeeeee Off Shore Stn. Off Shore Stn. No. 3. Bahama Bank. eeceeslseoveeelseceee eevcceelceoreeclescees eereeelcoseeeloeeeee eoseee| “[| levceee eeseeelsccevcleovece eovccee| “{ |evveve eeceere leo sees lecsene eeceeelceseeelerrons eevcee| “f |eereae eeeecelcerer se leosees sere ee ls ese ee lserece seco ee! ee cee se ee ee lsecceslecsoee seco ee cece slersene wm ee ee lee ress lececes eee ee were ee leeseee DOONGO)) Gp jococod we ce ee lec ceerlecvene 600000) Sr Ilocos eee ee lee esos lee veee eet ee were ee leeeeee cere es leo reeeloecene sec e ee eevee elececes Dcn0000) ap ihooooo eee ee corer elec esee ee rees eee eslesccee see ee ee re re leeceee sere lee ceesleccens wee ee secre elon sses ocoodo) (Sam joonoGa ee cceeleosceslecsees Peewee weer er lereees se ce ee lee eeeeleseees seeeee | seeeee | “T leevees Lune Deep. ececoe eccoee eeceee eoeeees eeceee eeceees ee eeee eceees eoeeee eeeeee eeeeee se eeee serene 181 Port Erin. Luce Bay. evccee eereece eoseee eeccee eereee eecoee eerece eevee rleencoee eeceerl|sesece eccees ercece eorcee eevee serene eevee clecrere eercetlewrecs ceeees eeccerleosaee eeeeerleeseees sere releoseee weceerlerroee eocecsleerone were orlessece seen eereee sere rlensene were er lensone eeeeee tere eelewsene tenes tenons eeeeee eereerlanenee 182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. July. | Se || 2 ‘ Belg Pr ener |e ay , : | sl si@ele |e |8 | 12 | 8) aoe | B@loklskl2als 18 18 |8.|8 18 (2) au $ |S5|23/68| deleel|as| @u| 22) 22 eo) & |u| @al|se| ee|aae|42a|/H9/H S| HS| aa = o | 3 A 4H SR] SF] OM 01m |04;041|04/MA| Ay 4 Bellerocheamm@awleus wc. J. scale eels. adeeleestedlooaes PF tae cwss bevel] ae soni obese |e ee eee eee ar + Lise Biddulphia miobiliemsis -..). 1.06. |scece.|seccee|eacsecte fecee| eens +s |e cneeelecwecely aeee eee ee ee aa ee Cheetaceros AeCipPIeMs: ~ j....|.4secie|s savne|sadeeeledesse|saeees|eaecec|scines |e .ccele' [ose eee een a + tae WEAM PIA ZOOGIACUS. — 4.0. <|idcees|eceres|onerselcassa|ecueas|s dasisele des on|- des o0)feceeee eee ae a + heeee Melosira Worrert. .citSic.decsclicesce|saaveolewessc|adeas ofaceees|eapeceladenee|odes a5] s4s: se eee + fact Rhizosolenia semispina ...|...... “te Ne cicaraibe siew,sw|oceiis.c|s ateeie.e||s:cioneiella dees .« |oideerae | Eee eee + |.aae EVhIZOSOleMIASCUGCTA« cacieelecensinlocseceleneod els coesel| ocene el scoaael> dosjeale ces eel queec eee a a ++. eae WorrtiUM TULCA,. crchc scemesiens|s doce eS |, gaciesells ope |cicbeetere]| Selelneeal| steers eee “+ |. wseee/esinn saleemeine ieee aaa CeLraON TUSUS, ccc sienccnceescledcnes Be | ASEM, See ca Scesusott see oll Dace eee “+ |eens sicile «teal eleoeee err Cera GLIPOS ec... ce S| al Es I > oo (a ot ae Id ear ie e +. |. c.@edlooeaee een Sey Oe Noctiluca miliaris ............ sy Set Sey SE TOBE UI oe ae oe auaee + |. necs|o0 cee fecal Eee Pleurobrachia pileus_......}...... Sl ame St Be ie even eaecerll see + |i. coins (ctoine'» oleic aime ee Wounie Aurelia. ....... 5.0 deoss|esiccslonense|tenee|esioaes]e vesidel esses os poesia sacle = teste eee. a a + aaa Medtisord sonophores 542. -c\ sce dlewecceloseese “bl evasise|eweeine [picicee oe ciiews]/sintep a] renee eee ea “+e Evhimodern Jarvee ...........-|- c= fle waveclecsoeclseceee|s secee|eeseee)essoee«le/spsinisie] soles pl Sete anna ean Sagitta bipunctata .........)...... Bt NN. Recetas dbersialls Seitoye FF lacow ele wee selene os ace eee er + |e PMUTOLY CUS POLTET os. 0200]. .jneelroleesnloeseralesensis|>aocee|slea'e|=eleeml[e aoeis el ictea call anaes ea aan + |e OMOPteris ONISCILOLFMIIS) ....)...2. |. ae. se lesieeselecpeee|eveceleeedee|e qed ole demesl|- dees eee aan + |. « charlene «l|cteome |e tere se |. wcees lees ee|s lee «|e » 9] Ree + | eam Pecudocatamusvelongatus <9 ssoelerase|ocee> =| cemenle specs = el ets | Oe ASE ++ |e ocis | pene eee + |accegy IRRa Cal AAU Se PAEVUS: 2.0: ae/s,c| sce ae|s ee eleakernel| seen allouines oe ee Pee MO ee + \eendi Temora longicornis ......... ee Se icfakalcclme.a {bats coll sneer “+ Lice Centropages hamatus ...... Spe f * Ste SE he a SL Coane eeecea le cee =+ |. ...=:o0| eee ee + na WentrOpankes UY PICUS, ..s...<|=-e5-c|ss sews bowel: ceeenlecest “be | cee leceecclow see les ene leieia'eatiiitel aa men Anomalocera pattersoni ...J + | + |......|...... eM atta eceeeers lerkvere ce + |, ccoerels eee ean + hkeaae Labidocera wollastoni ......]...... a at Pas Oe Ae | cos a ee Me I StS ECLA VAIS: Fae sicnicis sivas onecilae doce a [anne we|aicseeiale «mest epee af Jeane cic lee weee}ss pe o0|s oer aeetete ae + |. .seum PRGA UU CLA MSI ee. ee Sosicck « Soaales dente eral ae at at etal alo renal eae + |... soe eee ee + |.c.odae NG Ube GUSEDUGCAUA |. vse0 vccclecscrcefes enolase ealpre See oteee He |ocvccaleesecslacneoels ace onls ete ells mins GPO SIMU. 50sec boicc|> 0 ance |eadeivic lan geeic|eoeaicle em pearelemacte |e < l deen heen GING PIOUIA) iio ssieces eoede ae oe ee ae as at Racial pale atecialnic tie ss + |....00lareeenl ae + eae PSCIATAM COTS) oi. cleaconatecelt sane Ae | ccscalecccoelecbseuleceneslocnses)oscocsleebees|o0se«e/amem iii satin a Young Lamellibranchs......}...... ae Seceleobaiteles petelfew bite ses tnwals kale okietn| oe es/ee| te nn + |.. sah Woung GasterOpods .....6...)..ceselesseeelaesenefesieniee|eeseie|soveen|sesee=|scieces|s ees a|s c+] meant aeaamm + nena : PGIVC POSE eicc tenses dercevesace Seo) Ae eee = ae adios | Se s- |, Scovel eee ee + | eeu HESWPIAIVGR sees tcccnedenceeesees 4 | + | eke. oe ee Oe MMM on 10 | 23 | 6| 15 | 12 | 24} —|—}14/— | —}] — | 33 | — SEA-FISHERIES LABORATORY. 183 August. | Pee'| leg |2 |g Dp Q N wp) Q 3 : 6 fc S 8 qd g o 2 2 a S g a eee eevee |e 12.) 4\ sie Saisie s eae lS ol eam lal acs | a © | 2 eG # (26 /58|56|8e\5e|eelaslaclaolas| 2] 3 | 3 M |4eleo|e2\|om\|oalem|o4|o“z|ozimm| Al] ala Bacillaria paradoxa .........[......[eseee a2 a |s60o an! sca6cn| :0n06] 9 06 bal 6 460d OHOE S6 PORHOM HARHAA MARRS lo crc 5 0 Paduipiia mobiliensis ...|......)......|-..+.. GR ilpooacdl bpeeodl acwosclaopacl bane clhepodh| asses be ceee Mas: Petcomipiia amrtta | <...-....|......[...0+|-deeee Bim [bopoaclaeenoglbseee bladoho a SC sronl bade hal Aeron Aten BRRESSE by... ee re OMT CM 8 e525 onc alo |e tens’e|e reese |vcieeea|eaeneelodeses|eidvans[oc-noeletanc|eaceeslacenes a a B30 WEIN SEPIA oe. ..oces sc [ences |eccousleecees le On Gel Gd eel abba Sel Cone Ge enal Coes] Meee ay aan REAR BRhizosolenia semispina ...|......|......|....-- Sta lefetstaate | eines lela sets) Sa octet [es as ell Seieisesel| ens a's | vine + [ore ea ereteitemniNet....).....000..-|-00.00|esne meee Mercier e etcetera net leer lesiccste It semnaltete ac tecre ate pe Sie eel oes eMCARAMIM PUSUS <<... ...c0ccceeleesees stern teal lieeate™ Wictacesesll Me ae ida elle dome tiles ceseltciga es loasiae qe | | ae BeeiaMMiTipOs ............|...... See evs) eal aeane Slee Ne astecees loca deere ted Scars [Siete emiailereiisiec Seal am boco Migetinea Miliaris ............|...... +} + ] + |... Perea sc allbascepr sce tel Neale oc +] + |... Piemrobrachia pileus ......|......|......[ess00 HZ ba ddedl HoBoUel oe Badal Gemrodl SSa cet Oke Meeeom Saints + hee Medusoid gonophores ......|......|.....- Sl boStics bo nodal ke ede] poeees Haeecel bcmeen| anecite| ete! Saeneae ae lRodoce Sagitta bipunctata .........|...... ap se Se Thedsec Sol boeeade Remade Ceeeee ndeacal aseeee + | 4 eeeeee NN MEU eel oso les colonise dc lodacwe|s caswaledevec|seseoelooees cles sees locsees looses + liao MMMM ETON Sol. alae a «2 ccoeeo liaisons lasieveslonases|sr cone |oceeneleccscs|oecsesleceeneleare se “- lseeiae EME ADEE eo a|einicc.s |v snes|seaeeslececculacsess|oseemelncevuclasacelesceeslonane «loess Se cc. ENP oo oly oc ea clones esl ceeseloreeesloaeesslaccarsloeesse|slocses|revevs|oeee ce Se. lowes onc eee os ) LTE: 5 beaded +} +] + |... Pelee ches IRR cola laa toes ects | estes See es cic. DEA MISTAIOPA .........0ccc0e|oe ees se beaecter Sanne 8 Sth eS seen |Svaecteve [nye ateiil se cokes le he aie [cos ato lavaeee Wyeisisuage of Crangon ...|......|......|....6. ae dheeeee fae le steeeo leomacbeta | eiatans lerateesas [aeeeie le en ase “eae RUM TRE eo. «|. oc... lence ecle voces laces s (es cees sete |eenrea te aiseoys rile clare lacs cites | oeecteta « tevercacarc inserted (eae TINUE ee. cs csc cals ccc valeosccs|occevclesnyes|navees re eshte tll Mitsprs| ene SOR Stel Ae ae MEMMME PRR ER! 0 Eeratiemisto Oblivia ......|......|/.....|.... = ae arcane ayers aiscieee |e sctesel et cae [otcroaie:« [ose sae adarneed oo cae RE rd olsoica cal cioace (den ce|seoacelodsecaloeceoe|oose+-leneseelecceasleces - + loa BPAEMICE SPINISEK A... 02... |o..0..|eceeccleceees Flas leeheister)|eheveohe sila greta lea eciers (oaths nee [are nicleis||oie'e site [araeete « [are otc ee . (Tie (CTC el nn clea eter (traiectoes (et ceccale ea en ine cael ste nctroan [ce scnsll creas ea Pemminpermedium _......|......|......|...... =P leer Se ST lee aicterell eet atioe Mee oke learns lex astacle nates +. leo IME IGUOUMIAIIT 12... ....|......|.00.0-|occoce|eceees|eocees seer. | Seerere ee aarie leer ae lire sess gee was ledetec -| Soe Calanus helgolandicus ......|......|......|...... Bie Ware Hl aalboes dew cenaslboes del kote sa Hoe ee Meee + |eenaee LS 0 | + laces eee SMI AT VTIS.-.......|...-..|s000--|coe0e|eceess lev coe AEN mace ars Bea [tree siesera letete tice lite occ + | -+- 1oeee Temora longicornis .........|..:... Te ore al | Wea ie cea FCan ISS obtellachbe ol bomeae Siacee Heres Meee + ose Centropages hamatus ......]...... see tes, |i rata. SHES Ewe Me, ol MI che Ne oc cs, + | + ae Bema Mee IT MICUS) ......|......1.-.0-.|..cesslececeslecses Sid Meso 5 seers alaceaae GOROG a MACE AER SEE foe. MR ool eee clecececloosescleceeselecececlecersaleccect leceewcloeeoeeles ces. + lees. ES a | | PEs lets ein eevee leew e eRe la cca cule seca’ + ae Anomalocera pattersoni ...|...... alll ae aria acne = tT BEA Heise sr ieese ROaeie nee Meme +. caer Mmtedeora WOUASTONY ......|......|......|..0.0.|recessleececs Fete lsc mavees leaiacalteieen losses oloese6 lait aan OIA COVE os. - 20 :...|. 0.02. |.0...alseeecclecsees locos: = ered erate ctage | se oiors | etckctrotel lores eiove taste. aro'|9.0:7h 0:5 (eye RPO!) |.0.0-|oececs|oceesn|oaceos|receccloccseslecsecsloccoselocceccleecees + eee 0 CC atk we ral ke te wall Cee Sc SS Pe sel sr eee te Bean] ae |e + | - [ei PURE ONBORMOAUA, 52... ..22|..0.0.|eo0ceeloecccslevescs|eccess SHEE ec arses ets ae late tere lnietlo.c Mie soe ail ecensie’s «(so Grmmona SINS ...............|......|...... =| al Ke armel bra Hose ie baricl (ae Brier as BChial Moe! Gene eee + eee tee (|)... | 2.00. leceese|vcrees(necsccloceneslucceesloocecsloeevse[Ocsecs|eodoes bem | Le Re SE ss Biol, bs EEN Uae Da |e Ostracod stage of barnacles|......|...... en Ca a es ate hed aes Ie ers ccve'le tron live siacee lie wa.cte (5 cart a Ee a = Cid ate bal Be aes Stata [cts eed atncteialle cio a reall isintie.» [o-0/00:5,8 + |occees REEDS Noe |.ciccc's|crar'cclaseres|sosese|acceeslesewslrecseclegcces|ceeacs|eoveee “++ nee RE RIA MEDEATIGH 25.61. 0..5.|.-.00-|voecealecieensleccbes|ncieessloececeleccens|oenescleccecelecceeslecenes ++ ldenaete 0 EE a re a al SC SES ESE SA Picea 2S Ome Fi Piety ee | a + |eceees Meee eee Nees olycvocslooseceleoceoe|necces etaas il peeters lereictettta [ctaties |arelbrtell wc.ace’s [0's ablo.e leids Oate | Sem eV lion Ove lel aan eae ee ee |) LO: Soe 184 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. September. = Be a a D n > fey} ¥ g elnbletle (6 |2 [2.12 12) 4) 2 4 (2s)/ee)/2e| 4 |2 | & .|a4| algal o fone 8 |s2| 2 Be Eel Ea ss 16 | ag Gaerne 5 x g a |eelsa|ee|oaloalma|oz|oz/o“z| Alalala Asterionella bleakleyi ...... Ho] Hb | FB [ecsccleseetelocecelesseie|esiecec [erie cies setel/ete ets eee aa ian Bacillaria paradoxa ......... LE | | 4 fev cc eel ceee eects [occ ne|ooSeelee telat telseets| Sea’ i Bacteriastrum delicatulum | + | + | + |...c..|.scesclsccess|occses [essere |ecwseollaeedse lanes as] Gaeeee Sees aaa Bellerochoe malleus ......... + | -b [asecclecassslaacevcloctoec|eviwees|s ewe es[oclc ar lim cc sameee === =a Biddulphia mobiliensis ....|......|.....-|..s--. Ae |scieseleelne cefocincetels «ine etfs aja] feltees eee aoa = ema @hestoceros ComtOrtum~ -....|..\ses<|.nc-seleneeeclecnnes losis oalesceieels dedeels deaselocdes onl teeeee eee anne +r pioame Cheetoceros decipiens ......|...... | sb] AR |B |eseecele sles elves cllecleoere| oaineltel senate + ileseee CHEOCELOS TELES .4....cececeleeeess| ic cevelesisasslochecclesgeee|seie sles oe owls senceles eect eee ee aan Sa PS Coscinodiscus concinnus ...) = | = | =F |e.sscclsuseclecccc|oeoeec|eems ocleekees|-eeeetl aee=e aaa | “+ Aleem Coscinodiscus grani ......... = alee its oa (iit ee Cee Peer heats Pesenel eens Ppccos|Geccccics-¢e0)2 oo. |oi— ssn ee Nitzschia seriata ............ to] AB | HB |eveecclesceis [eeeiie|e'ieecs [ow eees|teere oe/fectereele eee eee =a is Rhizosolenia semispina ...|...... + | Ab | Fb |nseccclesusscleasecslee etc letieie leteieee =e iam Se eo Rhizosolenia setigera ......|...... bo |occcccleccccelersooelecsece|eeee s|essien [sis wesc lelelectet eee === ia Rhizosolenia shrubsolei Fa (iis pale lk ied (te eee Cone Pere eeaeee eecran Ba cana lscamoclacesec/ko---- “+. i cece Ceratium furca ............... Sn ics Ta i a a el Seen eerie pean Parse) PROS R6| Eocoaa in cc llonc “b deseeae Wenatiumlfusus 25.22... 66.2... to] bf a] Ae [a caeed [ieee etlee ects |steees lest scllaaeeee ana a Se Be CeratiimM TIpPOS y........-- oR LAE | Bente calcite eal eccess|oclsenl isles stl sae kil oaeee dintinnopsis campanula ...) + | + | =F |asiecu|eccecclesnce-|esee@e|o0cee-lecee+s|>- ee] eeeee aa a a Sree: Noctiluca miliaris ............ Ste Ok caer lec eee beecee + |sssesclescscaleceeecleenes [oes sll seneea aaa Pleurobrachia pileus ...... ee i ee es ee oe es a ee en MERE ce! - BPe (eo a. MarvaleAtmelian ssc. sj.cccsoc.s. +f |.cceve|seeccleccscelcoesseleceseclesesee|aeiseieele ie onl[eecsls inl See aaa. ts Medusoid gonophores ......|...... +} + + licks valiseees leases cl/asceet =e aan = See WaevalMCRINOGELMS — .c.<5|5. sce |cseeas|aceere|meces)osnss[eenea|- |29ee an Se oe Sagitta bipunctata ......... +} +} +] 4 fe Mots aoa leet oiallerctettorel lament ae Ree =F cae PAONBOMY EUS OROMLE ocak se eieteca u| oketeccallnsiad ot leo tne a eielderesallerotetaerel acetate ERR tases eel Se Rael eee Se ec “+ > loan Womtlopteris OMiSctiOrmiIs 2. 3\..62..|.emssalssee-- Sb aise aleve ccleeusies|sa ese laete ed =e aan + Jeseeee Wave Oly Cheeta... ccc... s<|nceees|sooaedlenbets ab | .esataldeeeacles sade wean cclae ll deecst “+b fwacnae VAN TNC Ca Vol Ch RMN Tent Die fics osuiliosee oils Gas olaeeene = BPC ooe + || cs ssleseooslecees + [0000 cde a a Se Mar Gal WODSGOL 5 icc0's0s05 0007l|ssee se |eadnes|s aco nleatsarilectea cel aaiseisclleeteee glee enon ee ee coet ae ee sae oc IST AONZIOCE, gone Walssieetias «vee eans ate Abita Se = a Sn ee ae Cen Perens sree Gere icons “> | -miseaee Crab megalopa ............... Se tee eee | Ses a sate Ba Bl mses chats coll setae aces ob ASaeee + oleae Mysis stage of Crangon + | + |.....- ty i) SE ll sattomsal se mare sd wate soll qette v5l| Serene Eee ee Oe MMV SIS feciche sss weeiccrescecucewas Se SE |screoe Te. losamsioleoecdlss eee cles vs vals beecloe'd seen inn + |ccanae AE VA CUMTACEA = i eoccecaees al. see +lecnaed| acon cel oetoaeloctsaal sane cdineutedlocme celvicgs oct. caeee ann ee Oe IGN CC 1S PALO OVE «5... oc 5's | victie wns ee so |w okie’ leman ol remer Ete Alacer aa] Soe acllciaee cal amaee |seese+leasene|ee ea eelsaemm BEV GUCCMMONTIIS: 5s cceee ss |oeanes| oes e ofc tave a) elias see ool WeReERl «tiie sete eelvictne loa tnet nn se NGVOMEA MM ATUN A tsePeietcsisccesei|. one se|coneacl dons eelfeemeleeneae SL lle seee|sieciese|seee0|ss00c0/eee aa ee oe eMac ietch ail bar tems cnn s'eiceisiew nines nese e||rro ie tase Selves “fe lensa|senncsleccess[oeeces[eerese|secne+|- eons tenn a PardubemistovOblivia ....|..c...|-ccseslosrece “EL lncceselecvoecle’scoes|ssonee|seso0e|s 000s »| se eee =a tain PMPOERUSA DISPINOSH ..ccineeclesoreelisereclesuseic|asgionc|sceegdleeeead|e panos ans cmes «le ceca sia ee Oe IGNATIUS ISPHIOSA, © oases ove alos sees veces slow ne ec|sotion ol ao meld motte senecs|scte on |e otes«[eoaces nn se MUM AT US cleis cite vie'gud vas scisinees|cseeeslondestlus ao tieloe devotee ce eelcomuenlieaskacsts ocls+cee+|aaue ts nn se ESE AUVIMSESWATMECEGAINT |... ec.|se ice «|-'enteienllee the «| seme disomic alee meee cette cai|os ee.nlleieebee |..+ 2d ata + fenseee EELIOC MON CMON OUMAMUS, . ... [4 vies eller wea] ncteine| cotacce lee eal lnanctod| tte enitalt ea|-' ao cel ene al PPro sco ee Oe PU UO IS MATES os Sieicaseis'a's|s oewoe|s ons s| ca dlveloateet Gemeee tome leeeenal oe tes a ten. ocfensrat |. o.sapr| ee ee Pinlomedes aniterpuncts, ...)..0.+.|:.0se-l.caec|uctheclocteelsetss elec gemele verse loves eslescace) teen + Joesme : Podon intermedium ......... ae oe By ||P Br aly Bee lee orl Bre’ Be Sel Senate + |eceseo| 47) iammmm SEA-FISHERIES LABORATORY. _ 185 September.-—Contenued. 1 | =| = =) : 3B a ea | ea mb | sy . 3 of seal 8 la ie 18 18 |e) salea mec | 2 \)oP (Eel Sale (e fe Peele |e.) see je | =a 8 | 08 H Gs =) i) aloa oO ® ro) o mM |@e|Se/ee|doaloajea|oz|oz/oz|/ 8) 4] a|4 Tee PINE TIPE [2222s ale cca ieee cc co |ec teen |Seecieie|cetesloweresleectes|asiesewlecsees|ecseaellestae» 5 i poco Calanus helgolandicus ...... BIEae Reeaicre stan sea losarciicte |anete’s [secocnalasasellnaoat boosealbodcee stem |sickeotei ag [pose UTM OM OS [oo ee ex |oweccnleoreee|oceses|oceees[eoesccloccees|eceate(eeesselooeens ar lbocase SP lboono- | arse tlamis parVvus .-.......|......|..0+-+ |e. AEs Ibeaode slate |Naleseeslerostels sues. sce ate Aleraexces =f losing | Temora longicornis ......... 36 || ee ee eel one FE bcoodalboascalloocosslbosces SF |bcooon aie |penaco | RE NE eis 2 cc |eaneeelocsee«|oaseealsessies|ebecne lees slecsians[acoers lew ovens leeseectc'es sc =e Weert TET Tae ra rics se cns «Sa enie |acasse leaden [sass lseesesloevaesloenoesteneene aes Seat “fase Centropages hamatus ...... te aR ecie rae cecte ll Sa Whe cosplbSsocalbsasenlasocee a lecsons Gime bocone MME UN SPUCTSM | c5... |. -ceculoeeveslorecealesesiseleecnacleoeees|oeeens|inesesleocess Sells oie oe siete orl Meany EMOMAIOCerA PALLETSONI ...|......|......[ececeeleeeees raul bisoae DOsRRS|oceoad bannee emcee = Dl daate oS | aeeer Labidocera wollastoni ......|...... sta este Prope trctal thar. cco | Saiecta.o fae gaiallorasereiot tt sleiareloseieies 3 | Anton nal selcicac El jateae MEI TEMG OEMS 22 f ce -| veel eco s|ovnee|ete once |eeeeeeloveveclecsece|ooswar{ensdeclerdacelersees “fe: liens EM Moen sae [ova s [once ee [ew cncn[eerces|ocense|ievecelonessclaccede|eeoees noo + . hisetee Preatiia Clausi.................. Sm eeteeclMeetee UE cle, gp cles 1M gates I tae leone [Seiauye cleiaeae s ste) iN cewiciee “fh? loatene MMOs SIMMS ...............|.0005- Sleeps Uevevanireesoaetece |ctetic ava I aherenis,|Ceaserestal gare all atersais' str Peake coh + ewes Euterpina acutifrons ......|...... x faa overstate paetebeve tt sxotoraei tote etal |ttetatete 4s lees/evarll se aialsall Moisieinailecascints ley dations leeettan Monstrilla anglica........,|...... Beryl letokeatere | tegamere Ye tates | hatatelorci(abaletardrol|Uisterciarollstersicrt ellAieraetes Lalsarseleeowcalef =: | aeeeee NIVEA ed Se | See os Mopepod nauplii ............|...... Fem et ortetene lS aaasere | tatatepe ersten lteter etaateisral efaeters levaloe acento ein lteter + ob | sevadian @erracod stage of bammacles| + | + | + |......[......lececeele Me cteis lected ctacie a oreereccicl acces aise Gl seseclele eee 0 ee Sree Mate cl cates Pata atarapa lopsdatser ol fetersire'| hcteta sl ctetdedvails esos ee Sere Sal Peco | 5... [a sasce|scvees|ssaraa|s ecu Saal beoncaleecese Sadpealteccca aneccd pects = veptes MEIN ASUCHODOGS) 22......|...2.-|.0000-|eccoce|ocoecc|eceees fil eveieere-cilatcectsraleterarer aa leretth tiallp arclass ile wise a os 80 CIIS 6a] Rte Oe A oe | | | ee A A lvaeden see bop acteses Ie Ooo Eteh il epeltete | eiaseyove| Sedsictoce eiviselstr| ta‘ arejejl|sjavecerein| Sevea/s sc ssaels.s + |ekemee ea Oe OSes eee etree falter eter teecell Haru ecpelcteteseete | armestac) erecta Soil, sielid.ailets sass! Menta 27 | 32 | 26 | 27} 9/ 14); — | —}| — | — {| 19 | — | 58 | — 186 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. October. l ; ; ‘ an eas |e ae & | Sots : | | am] . ees a) N wa = for : 4128/88/22 2 .)2.|8.|a4| aoi| des = | 28 e & (| 2e| Sal Sse) gal ea|2a|HoO| #6) Hola see A |4al(SH| BF) om\|om|sa|o“|o4\0A4) a) aie Bellerochoe malleus ......... ale A Asiew nsec + | sstscclecsees|eedecclhooaee lowenoe|s seca Seem entiae eee =———————— Biddulphia, mobiliensis. .5))....6|s-0--classe+- A | seseslescces|oeeseclssceecleeeren =e a ina + |.. cca Brddulphiaeurita. ..decccn|sechee|nenceelen-mes + Jesaccclevsecs[oasoee|occcceleossicslowene |alen sl ets—== =e Chestoceros ContortuM — ...|.....ch. ceca [ececsleccoes|eeseselesctenlercces|seseeelseetoe tl ———— aor ae Cheetoceros decipiens ...... a ae | Seen ol sacar Sb |aiseccslewsee's [ooeee's|ss care loc cote tenene = aaa + | + Cheetoceros Gres lasses ceva les cde slessiabl teas win| scan o| siete se | vio este.e [ev s'e 'c)| tacos |b ceil eee ee rr Se eee Coscinodiscus concinnus ...| + |......|...... Sed eS Ree eee ee ne Pe See y= - Coseinodiscus grani ......... Fe Sil slasialicaiac ae Hf |ecaevelecencelececcelescnss|oennve loess oa) aaemee |==— ia Rhizosolenia semispina a ae ee abe a. seats |stevaiere’bil ote aie.e% love aloes [everclear + | wee Rhizosolenia setigera ...... Sed | Seceinaleseate Po |ocencsfeecaes[aeee'ee|be sans |ocee= etme alien il epee a a Rhizosolenia shrubsolei SIR RA st fl oe Aa ab hiviaceleweeseleeew ov |oieiecleldee see teen eee aan Se SR CeratiumMehUsus! ys. sete ones Pf [feet tacts Sf locas ee [onesie e|eeesies [os sine|ee ones Eeee ae eee rr +] + CALA GMMIEUECA, «.65saccscosane Sh ll A ed te | ccaecaleceeesle ves cilae em oelleees clea see aeteete ia—e ae aan + Ceratiumi teipos ........00- Sad: lle tasorors |ctotetas Hb fciiewe|ecereeee| ze'ecroe [scammer See ae + {+ Trochiscia brachiolata ...... bt faecoccleceaee hs wnaaileetcioe|eeneles [ae care|sneciee [accel Nee Set =e ea Lintinnopsis campanulla. ... |... <0.|sacece|eocess|eoweeie|seasee|eeesele + seinelle «ese leceece ieee Meee a + | se Noctiluca miliaris ............ ats tle astetal aeras SEMA Ses “+ |. sce velecssie |e cee neiseiaicl| sei ee) Sees aa an ENeurolorac iia OMe ms: | secersils acteisiel|e ctes/o.|rermeree “+ levees eleotonslewseeeleeecine|sie soe lemimeyini ostaeee) seta Medusoid gonophores ...... tat lh tactoharal seta cere -euestate ete eye sb leven sielee sete [ee nes «| nicldetetel eae aaa + lea chimod erin lar Veen. sccrwiw'| ueceuie| sterel Seeeae “PJ aeeisisre leieeeie fee ee ee leis esses ore.aiee ele tee eee ee =} Loa Sagitta bipunctata ......... Stahl Se aeitra leaden ap als eecer sf |... caches cnee eee scion eel seen ae + |aaeene FUGOLYEUS PPO er. ..ciccc00i|snene|scneeol cori lomsiewo| vreeae|s ees [ore steels wajee teem see “oon Momo pLeris OMISCLLOEMIIS =...alteeceal:emecal meee. A |seweee|e eens [ease eeleie salsa chsidnin dl lsese eeraee ae + lew saa Larval Polycheta............|.. Ta aieiai rn's oieis| srbiniere:0}| = owererdh[e ecw ermrmeieial[ Shoe :0i0l| oe oem stereo err Se ppp Nites 7 kore tera nim do ctarictor aw ll. eenrral eee gael oe + |. ecceefeesews|seceeele ne sieni/e cess] ae a Wicai by ZOC aE ser tracttonidu «cnt ccsean se see| seeeecl eone of sterestors See Ce eee Coren eons Pec + Gra MEPAOPAr wasjvsescseeesteleeeieel| mesa seiavtelals warecls anne |e needs |e eine |e wceen|se nollalltelelse teeena aa + Miysis stage of Crangonm ....):....2|-2000-|-00:0. “f |acieineisace nian [oineinis [s e-sa:0 ai lecgisie'e felanioicle feed ee + VIG S1S 9 ie'e woseiciewitrwinais vs vide ere eies]e be/screlvpinorsls| top oe/otalb & selec] aceretra etanaiotel le eestor terest | ere |e errr + Ei C ELS UAT O OLA «xis. cersia\loicwwns)(eterseteral secrete ee erecia eee fb |accsee|eeceee lence oe eos fe s'eniete neta Sanaa HOG OM IMEEM MUM, ~ «2h he.-<)|seaeic<| seer teeeirle menial seek = [sa eeecleesse’s [scien |e ettielel eae e ee ame + |..cda ELGG Ml ORGUOUATATN. 5S .-cseiavatell oerciasciel Greece vorsile steered a oreeien eee oan A MP PO Calanus helgolamdicus . . ..ci.0)ss-sia|saeemnseectes =f. |e eistainel| « sieinsio alee eves! «lp 6 dL a | 3 guts: es Malaita ert 7 | . | = pee ee AN | oe ate oral a ‘gouoseiq | Pe | = pegjods | : cae A “‘qouoseIC, = UuOULUTOL) | : Ar Sar sare BA es a = Zo ‘preumn4s | og a a ae o (ae : : jae emer | et tet] [+t attt+t = pean Ge a We = s ash Trop | + Batata S ! See = Fe ad | air g | eee CA | + Ae ssa aa © || sae Po | = 2] woppert | + ee: iS) a =, ( (aaa RAR on Ns alt = < “pop | ate Z fs Py BOG | ; : = g : Wha PTe9S | = ‘aJOS : i fe pogesolie A | sole cS ale oe fe 2 | : : : a | ee aq JOUlI]OS | as is ee: a S E ‘qeq ysnoy | sire DS suo | || in rs 4 || - oe mn 2 e108 TOUS] | te <— [oe | = = = ae = << Bese jouy doy, | .- . ; = = e AMON | : ee aig aoe fe. ap ee ; ov & “FOS ee a sr = es | Lee, Re Shee (EL | are ctey = at 4 a re er ea eae -e Seer el | Ss | Be | a | : 2s SEG) es ote oe am. | Feat Ee old | 1 an ae — So . % oo Te . . . ries aie cies es eee: ce oS Ee i: : & ene ea re Sic ge ote ye ; re See ae ” =| fasy . ph PH ia OO % ; rs fas] S a o o . dP tee zo La f ° . DM (ab) ie) ~ PS) = as RS yg fab) ~ Oo = "© i 2 5 SREP E hs [eRe eae & Ow My oe ao ae) 2) HAAS SRAM Seeadana 190 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. *(PLOYOVTAL | aoqouy | i | 2 OSS is See ards Ee ee Pitt Pte gaa ial case HOACO MAW bie ge alk oe ‘qgauoseiq | pogjodg | ‘youosviq = | uourutoy | he sale aa 5 Shea prumy | foi i if: . oe ae Buyyooy | i if iit: Ss guy) ee eee Pippi bay “USA 1ro9 | heen: gua, |g sete SUE | es ra spoppen | i +++ 7m) 5 ae = “Ust PIeog | Gea eats t/a eed ae ge 8 ge poyesolse | | ah Se +|+ +)... “84JOUB[OS | ‘qeq ysnoy suo'T In Vicinity oF Port Erin. eieomoeed |i ee tne ee POU s Al = aaa ceteareee © ou Sesh falta A@MION . - . . . . BERS. . Ss ocur e aeeae e Sa ANSE A see Ws, eee ee eo eis IE capunop | as On Orr-sHORE Grounps, N.W. oF Piet To Liverpoot N.W. Licut Sure. Mes, 3 Ay + |... | was a Ae Se Months. August....... January... February..... Marche e2:. pril ay) Hebruary..... Mien Gliese 7X1 a ec ae May dimmer. cosa July September ... SEA-FISHERIES LABORATORY. 191 FAUNISTIC NOTES. By ANDREW SCcoTT. Young Fishes, Leptocephalus morrisu—Plate V. A perfect specimen of the tape worm form of the Leptocephalus stage of the conger eel was found by a local fisherman on April 30th, 1906. The fish was dis- covered in a small pool of water, left by the receding tide, on the shore, on the east side of Foulney Island. The Leptocephalus was living when captured, but as the fisherman had no means of keeping it alive it soon died. The man handed the specimen over to me soon after he got it. It was then fresh and perfectly transparent, quite soft and flexible. It was so transparent that ordinary print could be easily read through it when placed on a piece of newspaper. In extreme length it measured 118mm. The weight of the fish after removing the superfluous water was 1°2 grammes, and its volume 1°5 cubic centimetres. The greatest dorso-ventral height of the body was 9 mm., and it was broadest about 65 mm. from the tip of the snout. The myotomes were fairly - distinct, and 151 were counted. ‘The fish was colourless, with the exception of a row of black specks along each side of the ventral margin of the anterior half. There was also a similar row of specks along the lateral line, beginning near the greatest height and extending to. the tail. The black specks appeared to be placed at the junction of the myotomes, and were very crowded towards the tail. The presence of this rare form so far inshore is apparently unusual. The specimen captured was probably only a wandering individual, as no more have been seen. The figure is from a photograph, and represents the natural size of the fish. 192 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Amongst the other young fishes found in the tow- nettings we have to record the occurrence of post-larval herrings. - On January 23rd, 1906, a large number were found in a surface tow-netting taken off the Patches Buoy, Cardigan Bay, and also on the same day, off Llanon. A surface tow-netting taken in the vicinity of the Bahama Light Ship, on February 20th, contained one specimen, another tow-netting from Conway Bay, on March oth, contained three. The majority of these young fish measured 15 mm. in length, one or two 25 mm., and one 30) mm. ‘The other young fishes have already been dealt with. Fish Eggs.—aA table showing the distribution from month to month is given above. The first occurrence of plaice eggs during 1906 was in tow-nettings from the Patches Buoy, off Llanon, in Cardigan Bay, on January 2ord. They were again obtained from near the Liverpool North-west Light Ship, on January 3lst. From the latter date onwards to the end of March, plaice eggs were tolerably common in many of the tow-nettings taken in the open sea, and in territorial waters. The eggs of the Anchovy were found in tow-nettings taken off Aberdovey, on June 14th, and July 23rd. This is only the second time we have met with Anchovy eggs during a period of ten years. Their occurrence in British seas was first noticed by the late R. L. Ascroft in 1896. The eges were taken in a surface tow-netting from off Lytham Pier, and identified by Professor McIntosh. The | following fish eggs taken in 1906 have not previously been observed in the plankton of the Irish sea. Long Rough Dab: One specimen of the characteristic eggs of this fish was taken at Port Erin, on April 9th. The egg of the Long Rough Dab is about the same size as the plaice egg, but is easily recognised by the large size of the SEA-FISHERIES LABORATORY. 193 space between the egg capsule and the yolk. Variegated Sole: A few specimens were found in a tow-netting from the vicinity of Nelson Buoy, at the entrance to the Ribble, on May 3lst, and in another from Lune Deep, about five miles south of Piel Gas Buoy, on May 14th. Ling: The eggs of this fish were taken off Port Erin on April 9th, and off New Quay Head on May Ist. Mackerel: Large numbers of eggs belonging to this fish were found in the plankton samples from various parts of Cardigan Bay in June and July, off the entrance to the Ribble in the latter half of June, along the North Wales coast about the same time, and in the vicinity of Port Erin on August 27th. A very extensive incursion of adult mackerel took place during 1906. ‘The fish were caught in various parts of the Irish Sea, between New Quay and the Duddon, from the beginning of June right on to the end of September. Two species of ecto-parasites of fishes were taken for the first time in the Irish Sea in 1906. Caligus zei, Norman and T. Scott. Plate I. Several specimens of this species were found attached to the skin of a “John Dory” captured in the trawl of the “John Fell,” while fishing off New Quay Head, on June 16th. The only other known specimens of this species are in Dr. Norman’s collection, and were taken on a “John Dory” captured off the coast of Cornwall forty years ago. The female represented by the drawing on the plate measured 6 mm. in length. Lernzenicus encrasicoli (Turton). Plate II, figs. 6-9. A large catch of sprats were taken off Blackpool on February 19th, by the fisheries steamer, and a few hundred of these fish were landed at Piel. + Mandible) j , , S ‘ $ ae : y - =F . : > 1 i . * ’ i =e ‘ . ’ f ; 1 ; ¥ a . q q ‘ i= 25 Uy - * ‘ & si 1 A ' ' x + Ss , Say 1 & = s ? § 4 te it PLATE | ue PuatTe VY. ‘OZIS HEIN ‘TOW 1esuoyH jo osvys snjeydeooydery SEA-FISHERIES LABORATORY. 199 NOTES ON THE FOOD OF YOUNG FISHES. By ANDREW Scott. The tow-nettings taken during the summer months frequently contain the post-larval, and later stages of various kinds of fishes. In some cases identification is tolerably easy. In others, the work of assigning the post larval fishes to any particular species, is sometimes an impossibility. These tender objects are very easily mutilated in capture. In all cases, even when the young fishes cannot be identified with certainty, the stomach and intestines are now being examined to find out what the fish has been feeding on. The internal organs owing to the size of the fish, are naturally small, and cannot be examined in the ordinary way. The methods adopted in this work which give fairly satisfactory results are, (1) removing the entire alimentary system with the aid of a low power dissecting microscope, then carefully dissecting the stomach under a Zeiss A, or Leitz No. 3 objective, a cover glass is next put on, and the whole contents care- fully gone over; (2) dehydrating, clearing, and mounting the stomach, or even the whole fish, in the ordinary way for a permanent preparation in Canada balsam. ‘The former method has the advantage that little time is taken up in the work. ‘The latter one may take a few hours, and the results do not always repay the labour involved. As a rule, the shorter method is now employed. All the young fishes examined were caught by an ordinary open tow-net, worked just under the surface of the sea. The following are the fishes that have been examined, with the locality of capture, size in millimetres, and food found. 200 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Post-LARVAL CoTtTus. Milli- Locality. 1 Near Duddon Bar. 20.3.06. 1 off Llanbedrog, Cardigan Bay, 27.4.06. PostT-LARVAL GURNARD. 1 Red Wharf Bay, 15.6.06. PostT-LARVAL WEEVER. metres. 9 8 8 Food. 3 Temora longicornis. 1 Oithona similis. 2 Acartia claust. No food in alimentary canal. Remarks. Temora rare and Oithona absent in plankton. Acartia tolerably common in tow-net. 1 off Kilan Head, 5 1 Paracalanus Paracalanus not Cardigan, parvus. present in the 1 -< gS) : plankton, 12.7.06. 1 Red Wharf Bay, 12 1 Temora longicorms. Paracalanus only 7.9.06. 12 Paracalanus present in the PostT-LARVAL GADOIDS. parvus. 14 Isias clavipes. plankton. 1 Twenty-one miles 4 2 Ovthona similis. Absent from the N.W. of Piel, plankton. 20.3.06. 1 Five miles W. of 14 8 Temora longicornis. Temora only present Morecambe Bay 1 Anomalocera in the plankton. Light-Ship, pattersont. 7.5.06. 1 off New Quay 20 3 Centropages Centropages only Head, Cardigan, 25.5.06. Post-LARVAL ROCKLING. hamatus. 1 Oithona similis present in the plankton. 6 off Dinas Head, 14. No food. --- 15.6.06. 2 off New Quay 14 No food. — Head, 10.7.06. 7 off Morecambe Bay 16 No food. — Light-Ship, 21.7.06. 1 off New Quay 18 10 Acartia claust. Acartia tolerably Head, 16.7.06. 2 Temora longicornis. common in the plankton, Temora absent. Locality. SEA-FISHERIES LABORATORY. 201 Milli- metres. Food. Remarks. 295 8 Larval barnacles No larval barnacles 1 off Entrance to Ribble, 18.7.06. 1 off New Quay Head, 19.7.06. 1 off Kilan Head, 22.7.06. 1 Carnarvon Bay, 20.7.06 1 Red Wharf Bay, 7.8.06. 1 off New Quay Head, 10.7.06. 1 off Niarbyl, 30.7.06 22 Post-LARVAL SAND EELS. (Cypris stage). 2 Anomalocera pattersonm 95 1 Larval barnacle (Cypris stage). 1 Anomalocera pattersont. 4 Crab megalopa. 7 Crab megalopa. 33 1 Crab megalopa. PosT-LARVAL BELONE. 20 1 Acartia clausi. 2 Hetinosoma norman. 1 Acartia claus. 55 from various parts 10-17 No food. of the territorial area 1 Tremadoc Bay, 19.2.06. 9 Aberporth Bay, . 16.5.06. 9 Fishguard Bay, 24.5.06. 1 off New Quay Head, 15.6.06. 1 off Puffin Island 28.6.06. Post-LARVAL PLAICE. iL ING tOOds Post-LARVAL DABS 11 No food. ii NG food, PostT-LARVAL SOLES. 6 No food. 75 1 Longipedia minor. 1 Hetinosoma sarsi. 6 iy norman. in the plankton, Anomalocera scarce. No larval barnacles in the plankton, Anomalocera scarce. Crab megalopa very plentiful in the plankton. Megalopa scarce in the plankton. Megalopa scarce in the plankton. Acartia tolerably common in the plankton. Acartia scarce in the plankton. Littoral Copepoda. 202 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. PostT-LARVAL SPRATS. Milli- Locality. metres. Food. Remarks, 1 off New Quay 15 2 Pseudocalanus Pseudocalanus not Head, 10.7.06. elongatus. present in the plankton. 1 off Blackpool, 15 1 Pseudocalanus Pseudocalanus not 18.7.06. elongatus. present in the plankton. 1 off Port Erin, 16 No food. — 20.7.06. Youne Piper Fisu. 1 Red Wharf Bay, 66 2 Pseudocalanus No Pseudocalanus 1-9:06 elongatus. in the plankton, 2 Paracalanus Paracalanus and parvus. Acartia tolerably 6 Acartia claust. common. The food, in all the cases where it could be recog- nised, consisted of crustacea, chiefly copepoda. The group was represented mainly by the pelagic forms. The few littoral representatives found indicate that the fishes containing them had been feeding near the bottom of the sea previous to capture. It evidently does not follow that if a particular copepod is any way numerous, the fish feeds entirely upon it. In the above results it will be noted that there are several instances where the fish stomachs contained copepoda not represented in the sur- rounding plankton taken in the tow-net along with the young fish. The fish, no doubt, in its movements through the water encounters various kinds of copepods. It 1s not known, however, whether it feeds indiscriminately on every one, or selects particularly coloured forms. The majority of the copepoda are more or less coloured, and so may be quite conspicuous apart from their size. It is probable that the difference between the copepods in the plankton and those in the fish stomach is due to the unequal distribution. The fish may meet with a small shoal of Anomalocera, young barnacles, or crab larvae, capture a few of them, and pass on. It may then reach Pratt VI. Contents of the stomach and intestine of a Flounder. Nat. size. ¥ y . r + &. ' = bs : ae : Pools '”; > ; A < pi ; E « . ' ~ ‘ . 2 - . : x c m . bf i : “ ; : ra ‘ \ {Vv as igh + z y i a t- 7 +5) ; ¥ - ’ + - ‘ - aw y a © ‘ t A ~ ad x} ' o + NM : , iy * mn My * 7 s * F, > ‘ ry ae r fF > ; - 7 rT - Re \y ¥ . y > i M4 * + 1 = z A . > ; ; = : an t Z Wy ay : ; = 4 ~ uli = - . hey 4 oh 73 a aS °f Pre eA i ‘ t r a : . Pe _ : en : af - ra) > ae 7 , F > : ° - - F . a pet) wt Poe mn SO ee es Pye : = pod a A Ieee lie: Sly. a hee Wet Cre EL Ree Gant hin 8 = Gah Foe « ees Cf eee ee a Leh cna Rey Soe te ee ele etn tm LS Hari eS ier ae the lem = erent a : ms R4 i "s ‘ile s ae Pratt VII. Contents of the stomach and intestine of a Plaice. Nat. size. 2 re lee eee Te est ‘ee cn sore apa aly eee as me PennDOT am SOLE IE I ES eT - — . = ae ~ i 2 , x CN Gord oy” lo ° fo A i Fig. 3. General map of four fiords examined. The fiords in question are deep fiords and the littoral fry mainly lve on the relatively small shelves along the shore, in the zostera region, where the hauls with the seine were made. In 1904 about 33°5 millions of cod larvae were brought from the Flédevigen hatchery to the interior of Séndeledfiord. In 1905 33 millions of cod larvae were brought from the hatchery to the Sdéndeled- fiord, and 10 millions to the Hellefiord. The results of the hauls made by Mr. Dannevig and me are as follows :— SEA-FISHERIES LABORATORY. P11 SONDELED FIORD. HELLE FIORD. Larvae erat 2 Sie | Larvae P : Cod fr Pages eces : Cod fr cree, | pemhenl | oeeine | vertu Sept.-Oct., 1903 None | 4:8 None 1:9 July-Aug., 1904 33°7 10-9 33°5 None millions Sept.-Oct., 1904 | al atcat 6°5 July-Aug., 1905 11:4 Le) 33 4 10 millions millions Sept.-Oct., 1905 It is obvious that the number of cod fry obtained per haul varies both in the different years, and also in different seasons, independently of hatching operations, to such an extent, that no safe conclusions can be drawn from the above facts alone. Previous experience in this country had shown similar facts, and from the beginning of the work, the Fishery Board had pointed out the necessity of investi- gations concerning the natural spawning of the cod, the occurrence of natural larvae, the hydrography of the fiords in question, and finally the occurrence of littoral fry in the neighbouring fiords where no fry had been liberated. By order of the Board I undertook, in the years 1904 and 1905, such investigations apart from my participation in Mr. Dannevig’s experiments. The occurrence of littoral cod fry was examined in the neigh- bouring fiords: Sandnesfiord and Stdéletiord (see Chart, fig. 3). The seine employed was 38 metres long. Depth in the middle 4-5 m., in the points 1:75 m. Mesh, 16 meshes per foot (Norw.). A piece of net 5 mm. between the knots, 10°5 m. long, was inserted in the middle of the 912 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. seine. The smallest littoral cod fry could always be retained by this seine. With this seine the Sandnes and the Stole fiords were examined in July (respectively 10 and 7 hauls), and September-October (respectively 21 and 20 hauls). The hauls were first made in 1904 and repeated in 1905. In the Kristianiafiord 28 hauls were made in August, 1904 and 1905. All the hauls were made as far as possible in the same places and in the same manner in both years. The occurrence of spawning cod was studied by collecting statistics from the fishermen. The occurrence of pelagic cod eggs and larvae in the fiords and the Skagerrak was studied by making fortnightly tow- nettings in the following manner. A small motor boat dragged a circular net (1 m. diam.) of silk gauze for five minutes. The net was buoyed up so as to fish within a certain distance of the surface. In this way the net was towed 0, 2, 5, 10, 20 metres distance of the surface. The distance covered by the boat at each tow-netting was, by means of repeated experiments, proved to be about 2950 metres. The occurrence of post-larval cod was studied by means of larger nets dragged for hours, and also by hand-nets. The hydrographical changes in the Sandnesfiord the Séndeledfiord and the Skagerrak were investigated by means of taking fortnightly traverses of the waters im question. Also direct current measurements were occasionally done with the Ekman current meter, and also with other apparatus. These investigations have given a series of facts, which in my opinion justify the conclusion that the adding of artificially hatched cod larvae is incapable of influencing the natural stock of fry, even in very small and limited waters, to a perceptible degree. SEA-FISHERIES LABORATORY. 218 At the beginning of these investigations I considered it important to study the question, whether the natural production of fry was great or insignificant in the localities in question. To this end I have from Risér gathered statistical reports on the quantity of cod caught in the Séndeledfiord. By comparison of this material with the result of marking experiments (proportion of recaptures to number of marked fish) the conclusion may safely be drawn, that even in a small fiord like the Séndeledfiord tens of thousands of cod spawn every year, while the Flodevigen hatchery yearly manipulates the roe of about 500 cod (males and females) and distributes the hatched larvae over the whole of the Skagerrak coast. The number of spawning cod on this coast is indeed to be counted in millions. By making uniform hauls with a tow-net (see above) I have endeavoured to study the quantitative occurrence of eggs and larvae of the cod. By these tow-nettings it was found that the eggs of the cod may occur in such numbers in the upper layers of the Sodndeledfiord that up to 4,000 cod eggs may be obtained in five minutes’ tow-netting. A calculation based upon the supposition that the number of eggs gathered by a series of tow- nettings in the spring, 1904, down to 10 metres in four different stations, represent approximately true values for the whole of the inner fiord, gives very large figures. Indeed, we get figures so great, that we may safely draw the conclusion, that even the interior of the Sdndeledfiord, an area not exceeding five square kilometres, may in one single day contain more eggs than the Flédevigen hatchery produces in the whole season. And _ these quantities of eggs, the number of which may be calcu- lated at a certain time in a fiord, are, of course, not the 214 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. whole production. Quantities are hatched previously, masses are hatched daily, and new eggs are daily spawned. Also they are distributed by the current over areas where no spawning takes place. The natural spawning and hatching of cod eggs in the fiord is also of much longer duration than in the hatchery. Even before the fry of the hatchery are ready for planting out I have found multitudes of cod larvae in the fiords and the Skagerrak, and I have proved that cod eggs and recently-hatched cod larvae occur in the waters in limited numbers, even months after the opera- tions at the Flédevigen hatchery have ceased. The natural spawning and hatching of cod eggs is, therefore, in the small area, which I have investigated round Risor, of far greater dimensions than the produc- tion of larvae at F'lodevigen a production which is hmited to a shorter space of the season, and which is to be dis- tributed over a large stretch of the coast. In 1905 a series of hauls was made in order to test whether the adding of hatched cod larvae to the Sondeled- fiord was capable of influencing the number of occurring larvae. a s Liberated pees Kk peat 3 a Serultim “Med. Wittig Mie. v) Ax io mareh april oipril HI Ory Yoo re aoe (2- - 29. -------- My -- 10 - eee | 9. ie ge: 3l----- Itt----7+- iZ2- --O-- a=) fO--=-- 5-- 8----4--+ 33 - - --0- ---3-- 4. --.- 2-- Ca go24.-0-- —— Average vumber of cool fry pr baul 0-20 wa w=—-— Satiwity Yee St+.0 eon. ese eecee Depth of Lsopyky (o2zt Under surface. Fia 9. number of cod larvae, as mentioned above, and also in the number of other fish larvae. The above diagram shows the relation between the rise and fall of salinity, the isopykn of 1,021 and the average number of cod larvae per haul in the Sondeledfiord on the four occasions mentioned on page 215. (See Fig. 5.) | 220 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. In this diagram the four vertical lines denote the four dates of the investigation. The unbroken curve denotes the average number of cod larvae per 5-min. tow-nettings at 1 m. depth and 250 metres length, caleu- lated by integration of the figures gained by the 20 tow- nettings, which were made on each occasion at the four stations in the fiord. The broken curve shows the alterations in salinity at 20 m. depth in the middle station. The dotted curve denotes the distance under the surface, where, on the same station, the specific gravity of the water n stu* was 1,021, a value the importance of which has previously been mentioned. If we study this diagram we shall observe that the decrease in the number of larvae closely follows the upheaval of the salt water and the rise of the isopykn of — 1,021 towards the surface, expelling the “fry water” of lower salinity. When the salinity again was lowered and the isopykn of 1,021 again subsided the number of larvae rose. Similar phenomena were observed also in the Sandnesfiord, and the circulation in this fiord being quicker, the alterations in the numbers of fry T were here still greater. Also a study of the occurrence of the Pleuronectid larvae shows exactly the same _ great decrease in their number parallel to the expulsion of the upper water-layer in which they lived. These facts seem to me to indicate an intimate con- nection between the movements of the water and the movements of the eggs, larvae and fry. There is evidently a more or less constant circulation of pelagic fry con- nected with the circulation of the waters. The pelagic fry evidently drift in and out according to the changing * The weight of the water in grams per c.cm. + Also the number of eggs decreased more rapidly in this fiord. SEA-FISHERIES LABORATORY. DOr movements of the water-masses. The pelagic cod fry may, therefore, not be considered as belonging to a certain small fiord or locality. It forms a moving and changing part of the stock of fry belonging to a far greater area of water. As the movements of the water masses differ in different years, they would be expected to produce annual variations in the occurrence of the fry. This has, indeed, proved to be the case. In May, 1904, there was a very weak Baltic current and plenty of western water in the Skagerrak.* All the summer there were large masses of drifting fry to be seen in the sea and especially in the beginning of June they were very numerous. I could nearly everywhere note their presence, by direct observa- tion, under the drifting jellyfish, and easily catch them with a small hand net. I could anchor my boat in the open Skagerrak off Risdr, and observe the pelagic young of cod, haddock, and whiting in great masses drift past under the jelly-fish with a speed of 3-4 knots. The sea was quite full of jelly-fish and under nearly every one of them swam one or several young fish, which easily were eaught for examination. By towing my small tow-net (1 m. diam.) for five minutes, I could catch up to 39 cod, haddock, and whiting of 2 to 3 em. length. The “ Michael Sars’ found these young fish distributed in the upper layers over the whole of the deeper Skagerrak, and there ean be no doubt as to these young having drifted out from shallow water, because no cod spawn in the deep Skagerrak. In 1905 things were entirely different. This year there was a strong Baltic current.t During the early *See Bulletin of International Council for the Study of the Sea. + See Bulletin of the International Council for the Study of the Sea, 222 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. summer no young fish were, with a few exceptions, observed by me under the jelly-fish. Hauls of very great duration had to be made to prove their presence even in scanty numbers. In late summer their number seemed to increase under the jelly-fish, and in autumn the young of the whiting were for the first time to be seen in great numbers under the jelly-fish. The investigations with seines, undertaken by Mr. Dannevig and me in common, as well as by me alone, also shewed a marked difference in the number of littoral fry obtainable in the two years. In 1904 I ascertained that the young cod 3-4 cm. long, as early as in the last days of May, occurred in the Zostera along the shores of the Sodndeledfiord, the coast outside and in the Sandnes- fiord. Their numbers constantly imecreased and they were to be found everywhere along the coast, even in the Christianiafiord, in great numbers. In 1905 things were quite different. The facts are clearly shown by the following diagram (fig. 6), giving the average number of cod fry obtained per haul in the different fiords examined in July-August in the two years. It is easily seen that the summer 1904 everywhere is characterised by a relative abundance of fry. The greatest abundance occurred in the open fiords Sandnes- fiord and Stélefiord, which both have a lively circulation of water. Even in the Kristianiafiord, which by previous investigations (1898-99) was found to have a very poor stock of fry during summer was now relatively rich. The summer of 1905 was characterised by great poverty.* In the Kristianiafiord the poverty was, for example, just as prominent as Hjort found by his investi- gations in 1898 and 1899. The Hellefiord, where 10 * The temperatures and salinities were in both years practically the same in the fiords investigated. SEA-FISHERIES LABORATORY. 223 millions of larvae were liberated in spring, was very poor. The Séndeledfiord where 383 millions were liberated was a little richer. But the inner part of the fiord, where the majority of the fry was berated was exceedingly poor. The greater part of the fry caught in this fiord belongs to the section of the fiord nearest to the coast and the ‘‘ Skiaergaard.”’ This part was examined a couple of weeks later than the inner part (God fry hank |p PF hoes spp 3s ap sb 5 Send aa OM WU se = Hellefjord ! Aug 1904-1905 VY MU Fry /cberated | /9O05 Sanctke or july ee MLM ALLL ry wever Jiberated fee i505 LLL Fry reve: /iberated KvisHiania fjord A ug. /904-/905 Fry liberated both yecis + ~ Q | 3. es 2b as se 3F Yo as slo sso 7e_] 1904 1905 Fic. 6. Diagram showing the average number of cod fry obtained per haul with fine-meshed seines in the fiords examined, July-August. of the fiord and about three weeks later than the Sandnes and Stole fiords. It can be proved that the number of fry increased during this time, because also the Sandnes- fiord early in September was much richer in fry than it was in July. A similar diagram (fig. 7) showing the results for September-October will show this still more clearly. A comparison with fig. 6 will immediately show DIA TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. that the number of fry had largely increased in the Sandnesfiord as well as the Stélefiord.* These diagrams indicate the conclusion that when there is a scarcity of fry, this scarcity is common to a large stretch of coast, and when there is an abundance of fry, this abundance may be observed everywhere within a certain large Sdndek fora Wey ieee ae a plies “07 OF ig Stolefford Ock /Fo4-05 Fry ever liberated. Fig. 7. Diagram showing average number of cod fry obtained per haul with fine-meshed seines in fiords examined, Sept.-Oct. avea. The addition of artificially hatched cod larvae to a locality seems nowhere to influence the relative abundance of littoral fry in a recognisable degree. These facts, of which I have here briefly drawn the main outlines, seem to me to leave little hope as to the possibility of carrying out a fish culture, or locally *The investigations in Sept.-Oct. in the Séndeledfiord and in the Hellefiord were made with a more coarse-meshed seine than mine. This seine (Mr. Dannevig’s seine, see page 111) must have let nearly all the very small fry (under 6-7 cm.) pass through the meshes, the cloth in the middle being then removed. In July-August the seines fish about alike. The results from autumn may thus in these two fiords not directly be compared to the autumn results in the Sandnes and Stéle fiords. Both of these were examined with my seine, which could catch all sizes. SEA-FISHERIES LABORATORY. 225 influencing the number of littoral fry by means of liberating artificially hatched cod larvae. An exact proof is, of course, impossible to give, as it is impossible to follow and recognise the different individuals during development. A circumstantial proof or a calculation of possibilities is all we are able to attain. And our opinion of the matter must be formed on such judgment. As I have mentioned before, my investigations have proved that the fiords themselves produce such quantities of cod eggs and larvae that the numbers which we can produce from the hatchery at a reasonable price are small in proportion to the natural production. The liberated larvae are distributed by the current and mixed with the stock of fry belonging to far greater areas. In this way its importance to the naturally existing fry is still further lowered. Our investigations of the occurrence of the littoral fry give a clear impression of this. As far as I ean see the present proofs all point to the conclusion, that the natural laws and causes which determine the growth and distribution of the cod fry along the coast seem to be so powerful that the influence of the small and limited numbers of larvae which we possess the power of liberating, cannot be traced. Evidently these larvae disappear as an insignificant and unrecognisable part of the great mass of fry belonging to a larger area. 226 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. REPORT ON EXPERIMENTS WITH MARKED FISH DURING THE YEAR 1906. By Jas. J OHNSTONE. The experiments with marked fishes begun in 1904 were continued during 1906. It was our intention to mark 1,000 fishes during this year, but for various reasons little more than half that number were dealt with. At the beginning of the year it was suggested to me that the plaice caught in the course of the ordinary trawling experiments carried on by the “John Fell” should be marked and lberated—that is, that special cruises for the purpose of catching fish for marking experiments should not be made, but the routine trawling experiments should be utilised for this purpose. This policy was adopted, and with one or two exceptions the fish marked and liberated were caught on the ordinary trawling stations visited as a matter of routine by the “John Fell.” From several points of view this method is to be recommended, but the general result has been that smaller lots of fish were liberated than was desirable. In future it would probably be better to concentrate these experiments, and spend more time on each, catching and liberating larger numbers of fish at fewer stations. Experience of the distribution and migration of plaice has convinced me that quarterly marking experiments (roughly speaking) would probably give the best results. The fish should be liberated about the end of October or beginning of November, then in February or March, then in June or July, and possibly also in September. In this way we should make the experiments correspond with the times when the fish are changing their habits. SEA-FISHERIES LABORATORY. DPA Pressure of other work interfered at times with the experiments of 1906. It was not always an easy matter to obtain sufficient quantities of fish of suitable sizes. Then during November and December very rough weather was experienced, and some projected experiments had to be abandoned. As in former years, I am greatly indebted for assistance in these experiments. Both Dr. Jenkins and Capt. Wignall have given every facility and displayed great forbearance during the prosecution of experiments which have, no doubt, tended to disturb the usual routine of the patrol work of the “John Fell.” As in former years, the chief Fishery officers have given indispensable assistance in receiving and forwarding marked fishes handed them by fishermen. Several members of the Sea Fisheries Committee (Messrs. Harley, Dean, Houldsworth, Saycell and Garnett) have also given invaluable assistance, and several gentlemen (Mr. Robert Knox, Douglas; Mr. A. J. Rust, of the Milford Haven Committee; Mr. F. B. Rees, Milford Haven; and the Customs’ officers of that port—Mr. T. Parker, Glenluce; Professor D’Arcy Thompson, Dundee; and Mr. E. W. L. Holt, of the Irish Department of Agriculture and Technical Instruction), quite unconnected with the Lancashire and Western Sea Fisheries Committee, have given every assistance. During 1906, 683 plaice and other fishes were marked and liberated. Of this total number 88 were flounders, 38 were dabs and 13 were small brills. One large cod was also marked and liberated, but was not heard of again. No soles were dealt with, as our former experience (and that of other investigators) of marking this fish has been unfavourable. Flounders give very favourable results, and so also do brill. Dabs, on the other hand, do not 228 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. withstand the marking operations with much success. Both dabs and soles have strongly ctenoid scales. These are probably used to some extent for purposes of locomotion, and the fishes no doubt drag themselves along the sea bottom by means of their rough skin, and in so doing cause the attached label and button to chafe the flesh and cause a bad wound. Soles, and probably dabs, are also more susceptible to slight skin abrasions than plaice or flounders. 3 As before, it is no doubt the case that marked fishes have been caught and were not reported. I have heard of several such cases. Capt. Wright, Chief Fishery Officer at Fleetwood, reported the finding of several marked fishes, and information as to one reached me from a friend in Cairo. In most of these cases identification of the number of the label was impossible, so they are not included in the lists given in this report. The summary table on pages 230 and 231 shews the stations of 1906, the numbers of fishes liberated and returned and the percentages of recapture. It also includes the numbers of marked fish liberated in 1904-5 which have been returned during the past year. Before discussing the experiments of 1906, the latter may be considered. It will be most convenient for the reader if I present the results of the experiments in the form adopted by the German investigators, working under the International _ Fishery Investigations Scheme. “The analyses of size of fish” give the numbers of fishes marked and liberated. Sizes were always measured to the nearest quarter of an inch. For convenience, the headings of the columns in the tables giving particulars of the fishes returned are numbered as follows : — SEA-FISHERIES LABORATORY. 229 1 2 3 A 5 6 7 8 Srg ww 2 5 2 ie) o So o = a8 0) s Bee ce ° oS eer Onc lneieno une Se are | ree SS BSS oS, Bs oV2 RES | gas os, Se semis | a S OS | EOS) eae | © ae | =e N 2 = —= 9 =a) ot 0S N Om oon o 2 ot om A, 2 3 e~ oO a= Ev am wm = a =u The symbols (8) denoting method of fishing by which the marked fishes were recaptured are:—ST’, steam trawler; 1T, Ist class sailing trawler; 2T, 2nd class trawler (shrimper or fish trawler); TN, trammel net; SN, stake net; GN, gill net; B, baulk; T, “ tees.” Sizes are given to the nearest 4th inch. “Time in the sea” is given in months (4-weekly periods). FurTHER RESULTS OF THE EXPERIMENTS IN 1904-5. Thirty-four fishes liberated in the course of the experiments of 1904 and 1905 have been recaptured during the present year. With the exception of experiments 21 and 22, 1905 (October, Luce Bay and Formby Channel), these further results obtained do not materially modify the percentages of recaptures given in the Summary Table published in the last Annual Report.* Interesting results with reference to the migrations and rate of growth of plaice are yielded by these recaptures, but these will be referred to later in this Report. In the meantime I give the particulars with regard to the recovery of the fishes in question : — Experiment 4, 12th November, 1904. Station: 14 miles N.W. from Great Ormes Head. L104 81 | N. by W. from Ballycottin, | 12/11/06 26 lsa Te island, S. coast of Ireland. Z| tae This fish has, therefore, been exactly two years 1n the sea before it was recaught. * Report for 1905 Lancashire Sea Fisheries Laboratory, 1906, pp. 103-150. SOCIETY. 230 TRANSACTIONS LIVERPOOL BIOLOGICAL ‘pournyoy 9ov}UI0IEd s oO oman NX Oetonnaa SOmODtON eS = “pourmnjoy “ON CHNGOLHA GNV GHLVaYHEIT SHASTA WO eal ey sored OF repunoTy T sored [7 soreld OF SIopuno], EF EER SIOpUunoTy 6 aareyd gz EqED sored 67 srepunoy Z tee lk sored ¢% MEG srepunoy ZI sored QT Ree sIeapunoy G soreld g sIopunoy OT eoreid OT aoreyd Gg ete Je eoreld FF /POFeLOGIGT ON 90/9/F1 skaielefalaisueveata terereleleiecershetberelcio aleererete ainiecaielelelelevsnauvel are 50 pAqskyaueyy uO 90/9/81 Cee meee medrese rer ee ere eee rere sesseesesseeeeeees coos TOUT Ag IGON, 90/9/81 Cote e reece cesesee g sero cree eee ce res cseseceesee Aong WOSTON IRON 90/¢/6 Coe meee eer eee re cere en eee see essereevesseceece siege 2 (2115 § IVON 90/¢/TE SvasevayarefoLohsloneacioyetolets ielomev els etere; aicinecerniereesaeehs pueysy Aouye AA opising 90/¢/0& Cee e eee ee eer eer ere ers stoe ese tessees punory peso[g joodyorlq 90/¢/9 keg udAMjoo 90/¢/G Ce Pee cee eec eee res eee cereus se sce ese eee ccc ceserere joodyor[q IVON 90/Z/1Z Pome emer reese sce ese cres eres eseeresseevessess purysyT ung ICON 90/2/0Z Pere ere secre ere eroerescecessreeses cesses sessece yueg eueyeg 90/2/61 Coane vc vce ena ssc cen es nec ase cnscce cavice sic seceee poomyae]y IeeNy 90/2/T DO OUD DUN ON OOND FOU OOOO GOO OODOU0U50E prey] seullg yrorg Ive “o4yed *poxerleqiT YStq ee M UOTYRyIG © — AGVAWNOS IVAHNAD SdHaNWNON AGUNV SNOLLVLS IT OL 231 SEA-FISHERIES LABORATORY. GOT ONnNK ‘GOBL SULINP pouInyoer SOYSY g sopntouy 4 *sejou sAo0qe veg f "GOST SULINP peurnyer YSY T sopnpoug , goreyd OG sored [PF eoretd og soretd OG hee IL sored OT sored OZ eeceeeseeccecee ""QO6T UL pouInjer soysy [eqo7, C6 ww ew ee eeecc ccc ccc ccc c cen cccs eae GO6L A quewliodxy C6 = woo eo ceercescececce eceecrcevecece eee GO6L “16 queued xiy "90181 g ""G-TO6] ‘OZ VT ‘OT ‘FT ‘OL ay ‘ squoultied xq —!G-f06} Jo syuswiaedxg” [®I9O.L oo ees ee p09 rte aa ech Eh nee, Pace sqeq Tet i On Rts Ae eae ene A _siopunopy] : ae aca e ool’ d —? 906T “90d Jo pus 07 sTeIOT, : 906] JO SyusUTIAEedxY 90/01/ ake)elalolintelalelevelnjeueletukelelslelsielersinferetarare aieleyavere eevelereteseluisielalalajelurnie Aeg oon] QT 90/6/6I ara)aie le! sie) els ele tele efeleleleeyelclalelslelpisieiursis)steiaiaiarereie COLO OOOO keg jIVUM pey LI 90/21/Z1 axe veimintvin qvalala\w atate/a) siete is) ealeisislainiaialersialslninycjecalcleleletaieiaiciereietete uepLyueg HO OI 90/2/6 pee Sia Ye Se Uo ee eee WOSTON, IVON GT 90/9/9T CRC MCP i FOr CRC ECH BLEOY BMC RCEOT ECE GICHICRO IOI CCA oc yor sAU yO al 90/9/9T isl eleva) Cinpecejaceisiulwusih’s 6bie bie"e:ee's eiuveimateaelele e Gene nee eels w prey seul TO el 232 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Experiment 7, 18th November, #o024 Station: Luce Bay. Four fishes are to be added to the former list.* 1 2 3 4 5 | 6) vaaes | | | L242 8 | Off Chapelrossen, Luce 7/2/06, — | 123] 44 | GN Bay, 5 fathoms. L252 84 4 miles W.N.W. from | 28/2/06; — | 10 | 14 | IT Whitehaven Pier. 4 L287 82 Off Largs, Firth of Clyde | 12/11/06) — | 15 | 6} | 2T L288 82 Off Stairhaven Harbour, 4/9/06; — | 154) 64 | GN Luce Bay. Experiment 10, 17th March, sa0ce Station: 5 miles W. from Morecambe Bay Lightship 1 2 3 4 5 6| 7) 8 L490 82 10-12 miles S.E. from | 14/7/06) — | — ; — | ST Maughold Head, 12 fathoms. | Experiment 14, 6th) July; Po@ee Station: 2 miles W.S.W. from Liverpool Bar Lightship. 1 2 3 4 5] Gil alee L528 10 Caldy Island bearing | 10/7/06 | — | 14| 4] 1T N.W., 15 miles distant. L541 82 10 miles W.S.W. from | 17/9/06 | — | 144) 52 | ST Smalls Light, 57 faths. Hxperiment 16, 22tho July, 19a Station: Near Bahama Lightship. 1 2 3 4 5 | G6 lee cies L587 9 8 miles S.W. from More- | 7/7/06 | — | 102) 12 | 1T cambe Bay Light Ship. | SEA-FISHERIES LABORATORY. IASI) Papecmment 17, Ldth July, 1905, Station: Blackpool Closed Ground. 1 | 2 3 4. Sele Orly |. 8 L821 7 Morecambe, opposite old | 30/12/05) — | — | — | 2T Pier 3 fathoms. Pexeperiment 20, 22nd July, 1905. Station: 5 miles N.W. by W. from Aberystwyth. 1 aH. 8 aie i 5) 6 WT, '8 L848 8? Horse Channel, Fairway, | 26/9/06 | — | 123; 33 | 2T 10 fathoms. | iagerement 21, 13th October, 1905. Station: Luce Bay. Fish caught in Luce Bay. ANALYSIS OF S1zEsS oF FisH LIBERATED. Sizes (inches) 8 | 94 | 10 | 104) 103) 102) 11 | 114) 12 | 124) 123) 13 No. of plaice eee Wile oe I NA eZ 1 Pee al ANALYSIS OF S1zES OF F1sH RETURNED. 1 2 3 4 oy Gn 7) 8 L860 11} 5 miles W. from Stair- haven Harbour, Luce ; Bay, 7 fathoms. 31/7/06 | 10 | 14 | 2? | GN L868 8 Off Sand Head, Luce Bay | 24/8/05 | 1 |— | —{ GN L864 102 5 miles W.S.W. from | 25/6/06 | 10 | 13 | 24 | GN Stairhaven Harbour, Luce Bay, 6 fathoms. L875 124 2 miles W. from Stair- | 23/4/06 | 7 |) 123) 41] GN haven Harbour, Luce | Bay. L865 102 Probably near Maughold | 1/2/06 | 4 | 10?)/ — | ST Head, I.0.M. L870; 104 17 miles N.W. from Piel | 17/2/06 | 4 | 103} 4 | 1T | Gas buoy. L876} 12} 8 miles W. by S. from | 17/3/06 | 5 | 134; 4) ST Selker Light Ship. L871 103 6 miles E. from Bal- | 25/7/06 | 10 | 123) 2 | — briggan, Co. Meath, Treland. 9234 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Experiment 21 of 1905 was made while trawling in Luce Bay for mature plaice for Piel Hatchery. Twenty fishes were liberated, and during the next twelve months eight of these were returned. Four of these were recaptured in Luce Bay itself, not far from the place of original capture. An interesting result from this experi- ment is that for the first time we have observed a migration from Luce Bay into the Irish Sea. Previously the fishes marked in Luce Bay were recaught in their original habitat, in the Firth of Clyde, or in the Solway, but three (Nos. L865, L870, L876) of the lot here considered were recaught in the Northern part of the Irish Sea and one (L871) on the East Coast of Ireland, which it probably reached after traversing the waters Kast of the Isle of Man. Experiment 22, 26th October, Sigua Station: Entrance to Formby Channel. Fish caught in Rock Channel. ANALYSIS OF SIZES OF FisH LIBERATED. 103| 123 Sizes (inches) (2 eSa\aase 9{ 93; 93 93 104 No. of plaice AN te) 1 L904 104 2 miles N.N.W. from | 26/9/06) 12 | 134) 34 | 2T : Liverpool Bar Light Ship, 13 fathoms. L910 84 Rock Channel e.-cece7-c-2 31/10/05} 1 | — | — |} 2T L917 8} N.N.W. from Liverpool | 12/8/06) 10 | 10 | 13 |} 1T Bar Light Ship, 17 faths. L918 84 Off Newcome Knoll ...... 21/11/05} 1 | —|— | 2T L920 9} Horse Channel 222..50-<<: 17/11/05, 1 | — | — | 2T L925 Sz 2 miles N. from Formby 2/5/06} 7; 9| £1 2T Channel Fairway Buoy. L936 84 Rock Chennel, 5 faths....| 19/3/06) 51! 8jl $1 1T PARTICULARS OF Fish RETURNED—continued. SEA-FISHERIES LABORATORY. 235 1 2 3 4 oi Olle | 8 L941 8 Formby Channel, near 9/8/06} 10 | 94) 14 | 2T N.W. Buoy. L942 8} 12 miles N. from Liver- 5/8/06, 10 | 10 | 12 | 1T pool Bar Light Ship, 15 fathoms. L903 8 Boghole, Ribble ............ 17/4/06} 6| 8 | — | 2T L913 8} S. side of Ribble, opposite} 26/4/06) 6 | 83) 4 |SN Ansdell Buoy. L934 8 Bog Hole, near Birkdale 1/5/06} 7 | 83 3 | 2T Gas Buoy. L935 8t Jumbo Buoy, Southport 4/3/06} 5 | 84) — | 2T L938 72 Off Jumbo Buoy .......... 27/9/06} 2 | 104) 24 | 2T L901 84 Lune, near Glasson Dock| 18/12/05; 2 | 84) — | 2T Light. L939 84 Roosebeck Scar, More- | 3/12/05) 2) 83) — | SN cambe Bay. L912 84 Mostyn Deep, Dee ......... 14/12/05) 2) 84 — | 2T L908 8 4 miles 8.W. from More- | 11/8/06) 10 | 94) 141 | 1T cambe Bay Light Ship. L906 82 25 miles N. from Smalls 2/9/06) 11 | 114) 24 | ST Light. Experiment 22 of 1905 (Chart I.) gives results which are fairly consistent with those of other experiments. If consideration be paid to the length of time that has elapsed between liberation and recapture, I think the movements of the plaice indicate winter alongshore and Thus all the plaice (7) recaptured within the two months after liberation were summer offshore migrations. found in the shallow waters in the channels and on the edges of the banks. Four have travelled towards the Cheshire shallow waters, and three towards Ribble and Morecambe Bay. Then we have a group of five fishes recovered about the fifth and sixth month after liberation in the Southport and Mersey Channels. These have probably remained there after the initial Finally, there is a group of six fishes which inshore migration. have migrated, or are migrating out from the territorial zone, and were found after seven to twelve months in relatively deep water. 986 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Kxperiment 1, Ist Febrwary, 190m Station: Between Great Ormes Head and Conway Bar Buoy. Fish caught in five hauls between Red Wharf Bay and N. Constable Buoy. ANALYSIS OF Sizes oF Fisu LIBERATED. Siva ((NGINES) coaoassoenncecooscees 7d 74| 73) (8°) “Sh Sk) S38 vouiaiae INOMO£ plaice ccs seds eee 2 By QL Os) 2a a ee INOSob-Galsie..nemncsn sn eeee — 1}; — ees es | 1 t Sizey Gches) Saaceeeeee eee eee eee 94; 93) 10 | 103) 103; 11 | 113) 123) 13 INO or plaice mamnnesteen-ceeeeee Gol Lg Qa. Sipe: |) 2a eee ee INGO wo8 absibe. oe Pes medumoaee c —|} l|— 1} — = 1 2 3 |. 4 5. | 63) simeee L712 9% - | 4 miles N.W. from Great | 5/8/06) 6 | 102} 8 IT Ormes Head, 14 faths. | L716 10} Conway Bay, 5 fathoms... 13/11/06} 10 | 134) 3) 1T L721 84 N.W. from Great Orme, | 30/9/06) 8 | 114; 23) 1T 15 fathoms. L733 8 Off Great Ormes Head...| 13/8/06) 7] 8% 3) 1T L747 9 2 miles W. from Great 3/5/06} 4} 92) 4 IT Dab Orme. 5 fathoms. L734 82 N.N.W. from Liverpool | 12/8/06) 7 | 103; 12| 1T Bar Light Ship, 17 fathoms. L713 93 1 mile S.W. from Nelson | 21/9/06) 8 | 114; 2 | 2T Buoy. L728 84 Near Bar Buoy, Ribble...| 20/3/06) 2 | 84) — | 2T L702 104 7 miles S.W. from More- | 14/7/06} 6 | 123) 12) 1T | __cambe Bay Light Ship. L709 93 Holyhead Harbour, 5 19/4/06) 3 | 103; 2/‘Set fathoms. net? 726 | 10 | Off Lianon, Cardigan Bay| 10/7/06; 6 | 103) 4, — No decided conclusion can be drawn from the results of this experiment. It will be seen from the results, which are represented on Chart II., that four of the fishes returned have travelled to the North. Six were found in SEA-FISHERIES LABORATORY. 237 the Red Wharf Bay area, while two have gone to the Western District, one being found in Holyhead Outer Harbour, and one off Llanon in Cardigan Bay. Pepecrment 2, Station : Fleetwood. Fish caught in Rivers Lune and Wyre. eee el evosm uma 10) 0)G,. Near No. 1 Buoy, Entrance to Wyre, ANALYSIS OF SIZES OF FisuH LIBERATED. Size (inches) 8 | 82} 84] 82] 9 93} 93) 10 | 103] 103] 11 | 112 No. of plaice Sm Onl ere A Doe Wet le 4 We Belen Soles 2 PaRTICULARS OF FisH RECAUGHT. 1 2 3 4. 5; 6| 7] 8 L758 104 Pilhimgs Sands) |e ecsntescne- 28/2/06} 1 | 104) — |Tees L763 on ealliniet Sands! +520 ...2.8 20/4/06} 2 | 94) 4|/SN L772 82 S. side of Lune, near No.5 | 11/4/06} 2} 9 +} SN Buoy. L774 84 Below Morecambe, W. | 23/3/06) 1] 9}, 3) 2T end Pier. L775 81 Lune, near No. 4 Buoy...| 7/4/06) 2 | 84) 4) 2T L785 8 Pillimo Sands.) se. acess 26/5/06} 3 | — | —|SN L755 11 1 mile N.W. from St. 7/3/06} 1 | 11 | — | 2T Anne’s Pier. L756 114 16 miles N.N.W. from 1/7/06} 5 | 133) 23) 1T Liverpool Bar Light Ship. L777 84 12 miles N. from Liver- 5/8/06) 6 | 10%; 23) 1T pool Bar Light Ship, 15 fathoms. L781 84 10 miles N.N.W. from 1/9/06} 7 | 103; 2) 1T Liverpool Bar Light Ship, 13 fathoms. L783 8 Near Formby beach mark| 28/3/06) 1] 8 21 L761 94 4 miles S. from Bahama | 7/12/06) 10 | 123} 33) 1T Light Ship. L766 9 4 miles S. from More- 1/7/06} 5 | 10% 13) 1T cambe Bay Light Ship, 18 fathoms. L754 UA Between Barrels and | 18/4/06} 2 | 11|—|ST Saltees Light Ships. L762 8? North Bay, Co. Wexford, | 28/11/06) 10 | 118} 34) — Treland, 34 fathoms. L730 8} — 4/12/06) 10 | 10%; 28| ST L782 8 —- 4/12/06} 10 | 11 238 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Experiment 2 shows again the decided contrast between the winter alongshore and the summer offshore migrations. The results are shewn on Chart II. by black circles. Remembering that the lines connect the station of liberation with the points of recapture of the fishes, we see that the fishes recaught fall into two well- marked groups—(1) a group of eight fishes recaught within the first three months after liberation, that is before the end of May, and (2) a group of five fishes recaptured from five to ten months afterwards. The former fishes were all recaught in the shallow waters in Morecambe Bay and in the Ribble and Mersey Estuaries by stake-nets, “tees”? and second class trawlers; while the latter fishes were recaptured in relatively deep and distinctively offshore waters by first class vessels. It must be pointed out that the straight lines and arrow- heads do not in this latter case represent the actual paths followed by these fishes. Probably al/ those liberated immediately moved into inshore waters, where some were caught, and then after a sojourn there of two or three months the remnant migrated offshore, where a further proportion were recaptured. Two recaptures are not shewn in the chart. One of the fishes was found off the coast of Wexford, in Ireland, and the other on the South Coast of Ireland. This latter fish had in two months made a migration of, at the very least, 170 nautical miles. Two other fishes were caught offshore (by steam trawlers) after ten months, but the exact locality cannot be traced. Experiment 3, 20th Hebruary, 2oGae Station: Bahama Bank. Fish caught on “shoals” and in “ Hole.”’ SEA-FISHERIES LABORATORY. 239 ANALYSIS OF SizES oF Fisu LIBERATED. | t Sizes (inches) ........e...ee000- oy 93] 10 | 102] 103| 103) 11 | 113) 113 TAYE Sa hy ey esl ese ena a Le) a Oa ail) el Sa es No. of plaice BE Teiielneisassc0e0 — IMO OF HOMINGETSS. ..0cc.cssceseces 1 PARTICULARS OF FisH RETURNED. 1 2 3 4. 5| 6| 7] 8 L894 104 Silverdale Sands ............ 20/5/06 | 3 | — | —|SN Flounder L896 11 Foxfield, River Duddon...| 19/7/06 | 5 | 113) 3] B Flounder L880 10 10 to 12 miles 8.E. from | 26/7/06 | 5 | 124) 21) ST aa; Maughold Head, 12 fathoms. L882 10 Fish Market, Blackburn...| 3/4/06 | 2 | 10 | — | — L883 81 Fish Market, Blackburn...) 5/6/06| 4 | 108; 23) — L888 112 8 miles S.W. by W. from | 19/3/06| 1 | 12 1| ST Selker Light Ship. L891 10 5 miles §.E. from Bahama | 24/2/06| 1 | 10 | — | ST Flounder Light Ship. Experiment 3 gives no useful results. It will be noticed (see Chart II., circles with a horizontal line) that two of the flounders originally caught in Manx offshore waters were recaptured in the Duddon and in Morecambe Bay. The plaice recaptured were all found in offshore waters. Two of these latter fishes could not be traced with certainty. Papemement 4, 2ist February, 1906. Station: + mile N.W. from Puffin Island. Fish caught on Bahama Bank. ANALYSIS OF S1zES oF FisuH LIBERATED. Size (inches) ...| 9 | 104) 103) 103| 114; 113) 113) 12 | 122) 133) 15 | 26 Moronpiice...| 1 | 1) 1 1{/;—] 1 1 Ih al == | = Mon ornounders; |; — | — | — | — oe | es 1 1 ie Wo: ‘of cod ...... — | — | — | — | — | S— | — — | rs 1 9240 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. PARTICULARS OF Fis RETURNED. 1 2 3 4 5.) 6.) 0 ae L794 113 8 miles §.W. by W. from | 19/3/06} 4 |12]| 4ST Selker Light Ship. L792 114 4 miles N.E. from Cardy | 27/4/06) 2 | — | — | — Rocks, Balbriggan, Ire- land. L788 114 Off Connah’s Quay, Dee...| 12/7/06} 5 | 114; 4 |TN Flounder The fishes liberated in this experiment were a few which had been kept on board the ‘“ John Fell” while making a passage from Isle of Man to Red Wharf Bay. They were caught on Bahama Bank and liberated off Puffin Island. The number of recaptures is too small to enable any conclusion to be made. Hxperiment 0, Sth. Match, slo Station: 7 miles W.N.W. from Blackpool North Pier. Fish caught in Rivers Lune and Wyre. ANALYSIS OF Si1zEs oF FisH LIBERATED. Sizes (inches) ...] 8 | 83} 83) 9 | 93] 94] 93] 10 | 103} 103] 11 | 13 | 134 No. of plaice ...).3 | 2])5])/2)1]1] 2;/—] 2}/—]—]—]— No. of flounders | 1 | —|—/] 2 |—/3 | — | — 1 1 1 2 1 No.of brill”... — a | Se 2 1 3 1};—/]—|]— —— SEA-FISHERIES LABORATORY. 241 PARTICULARS OF FisH RETURNED. 16/4/06, 2] 83} — |B 15/6/06] 3 | 10%} 14/B 26/5/06] 3 | — | — | SN 12/6/06) 4 | 103; 1 | — 16/5/06, 3 | — | — | SN 18/4/06] 2 | 103] — | 2T 11/7/06] 5 | 12] 13] 1T 9/8/06] 6 | 133) 23| 1T 24/3/06} 6|12| 3 | 1T 1 9/,06| Gt eet eae 30/8/06} 6 | 128] 22) 1T 7/8/06} 6 | ST 1 2 3 L956 8# Near W. end Pier, More- cambe. L966 1 mile below Humphrey Flounder Head. L975 8 Palhmes Sands ssc. sa. a6 ves Flounder L979 94 Lune, Cockerham Bank Flounder L981 10 Sunderland Bank ......... Brill L962 104 Pinfold Channel, Ribble... Brill L944 104 8 miles N. from Liverpool Bar Light Ship. L958 102 Liverpool Bay, 16 faths.... Brill L968 9 10 miles N.N.W. from Liverpool Bar Light Ship, 10 fathoms. L945 82 Probably near Morecambe Bay Light Ship. L946 104 S.W. from Morecambe Bay Light Ship, 25 fathoms. L960 104 12 to 14 miles S.E. from Brill Maughold Head, 12 ~ fathoms. L964 82 15 miles W. from Black- pool, 21 fathoms. Experiment 7, 30th March, 25/7/06] 5 | 112| 23] 1T LOG: Station: Blackpool Closed Ground. Fish mostly caught in Luce Bay and kept in Piel tanks during winter. ANALYSIS OF S1zES oF FisH LIBERATED. BAC MINC ORNs cars occs ese. cescsececs 7i| 74 No. of plaice ....... oe ues oie - Eye occ csc ccesesececceccees —)— ES Ne GS) i 10} MUNG OM PNANC O55 e.. coca cccc ccc oncce cess —| 3 No. OU OLLIE Seether ie 1 2 | R | 103] 113] 124 143] 143] 15 | 153 1 1 i 1 1 1 249, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. PARTICULARS OF FisH RETURNED. 1 2 3 4. 5 |. 6) Hones LL47 103 Birkdale:shore *5... -cr-cse- 11/6/06 | 2 | — | — | SN LL67 143 14 miles 8.E. from Douglas} 18/4/06; 1 | 15} 4/ST Experiments 5 and 7 may be considered together. Experiment 5 was made with fish which were caught in Morecambe Bay, in the Lune and Wyre Hstuaries. They were liberated off Blackpool Closed Ground, a closely adjacent area. Experiment 7 was made with a number of plaice and dabs which had been kept at Piel Hatchery during the previous winter. It is the custom to turn these fish out in Barrow Channel at the end of the spawning season, and we thought it might be useful to mark and liberate some of these fish. Only two out of twenty-eight fishes hberated have been returned (see Chart III., circles with superposed crosses). Probably the cause of this poor result is that the fish were possessed of little vitality, and the operation of marking was fatal to most of them. Experiment 5, however, gives the usual result. Two groups of fishes may be distinguished (Chart III, circles)—(1) six fishes which travelled into Morecambe Bay and the Ribble Estuary, these were all recaptured within four months after liberation; and (2) six fishes recaptured from offshore waters five to six months after liberation. Of the fishes making the inshore migration, three were flounders and two brills. Of those making the offshore migration, probably at a later date, two were large brills and the rest were plaice. Experiment 8, SEA-FISHERIES LABORATORY. dlst March, 243 LOO Station: 4 miles W. by S. from Barrow Iron Works. Fish caught on same ground. ANALYSIS OF SIZES OF FisH LIBERATED. DIEM GING) Meet cise aresieiweiciee see sine see TH 74) 2) 8 | 8h) 83) 9} Of LT, Ci! [CENCE paces eaae eae eee a ae Oi See esa lad 1 BOMOLSMOUMGETS 6. cece cy ceeeeeeesenees —;|; l|—;—) 1 1 1 | — MAMMOENG US ecb aeciciceescccgecss ais secs. —}|— 1 }— 1 1 1|— “10% (I@CINGS)) Song Raa eee ates eee 94; 93) 10 | 103} 114) 113) 133 MPO COMI 50.0.0 0cccsecceecnreresescens PTL eee ee TO MOMMMGUITACELS! . 22.0... ...ceeces cence eesecees Uy a es a et a HOSMOMTE EOS eri co2 soa ons oe gsi seesesecese-ccecs 1;—j;—|]—j|—] — |] — ParticuLars OF Fish RETURNED 1 2 3 4 a 6) 7) 8 LL76 92 Bardsea Sands, More- | 19/4/06; 1 | 93?) — | SN cambe Bay. LL78 94 Baycliff Sands. More- 2/6/06} 2 | 103) 14) SN cambe Bay. LL86 114 Near Baycliff, More- | 25/5/06) 2 | 114) i)/SN Flounder cambe Bay. LL87 103 In Leven, Morecambe | 13/6/06; 3 | 11 4) SN* Flounder Bay. LL102 72 Off Haverigg Sea Wall...) 8/9/06} 6 | — | — | Lt LL106 74 West Hollow, Mbore- | 23/4/06) 1) 73; i}SN cambe Bay. LL112 14 Bardsea Sands, More- | 30/5/06} 2] 8 4) SN Flounder cambe Bay. LL113 4 1 mile above Humphrey | 13/6/06; 3] 94; 1)|B Flounder Head, Morecambe Bay. LL98 8+ Off Nelson Buoy ......... 13/7/06 | 4] 93) 13) 1T LL73 113 4 miles N.E. by E. from | 27/8/06) 6 | 13 | 14/11 Morecambe Bay Light Ship. LL1OO 13 9 miles S.W. from More- | 23/7/06, 4 | 10 | 24) 1T cambe Bay Light Ship. LL104 84 15 miles S.E. from Maug- | 23/11/06, 9 | 102} 24) ST hold Head, 12 to 15 fathoms. * Salmon Net. + Line. 944 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Experiment 9,/)9th” May .0oe Station: 3 miles S. from Piel Gas Buoy. Fish taken from Piel tanks, originally caught in Barrow Channel. ANALYSIS OF S1zEs oF Fisu LIBERATED. Size (inches) ...| 83| 84| 83) 9 | 93| 94] 93] 10 | 104] 103} 11 | 114) 122 No. of flounders| 3 | 2 | 7| 4 | 2 8 6 by 5 3 2 1 1 PARTICULARS OF FisH RETURNED—ALL FLOUNDERS. 1 2 3 4 5: | +: 6c PaaS LL117 9 Barrow Channel ......... 8/06} 3} 9 | —|SN LL118 9 14 miles below Hum-| 26/5/06} 1] 93 4|SN phrey Head. LL123 gi Kirby Pool, Duddon...... 11/6/06; 1} 93; 2£)SN LL131 9: Bayclifi Sands .-.........- 14/5/06} 1] 93) £/5SN LL135 121 Near Millom Pier, | 18/6/06) 1 | 124) —|B Duddon. LL142 94 Bayeluti (Sands). nn.cee-eee- 11/5/06) 1 | 93| — | SN LL152 84 Foxfield, Duddon ......... 21/5/06} 1] 93} #4)B LL154 101 Roxtields WDuddon ts... 4/6/06) 1 | 103) 2 |SN LL157 104 Bolton-le-Sands_......... — — | 104; — | SN Experiments 8 and 9 may be considered together. Experiment 8 was made with plaice, flounders and dabs caught off Duddon Bar and liberated in a closely adjacent place. Experiment 9 was made with part of the stock of spawning flounders kept at Piel Hatchery and liberated annually. These fish were mostly caught in Barrow Channel. They were marked in the Hatchery and liberated near the entrance to Barrow Channel. | The results of Experiment 8 (Chart III.) indicate the usual two groups of recaptures. Four plaice and four flounders travelled inshore towards Morecambe Bay and the Duddon, and six were recaptured within the first three SEA-FISHERIES LABORATORY. 245 months after liberation. On the other hand, five (four: plaice and one flounder) were found in offshore waters from four to nine months afterwards. Kixperiment 9 (Chart III.) indicates an inshore migration of flounders in the early summer. Not only did all the recaptures of flounders taken out from Piel take place in Morecambe Bay and in the Duddon, but four flounders caught outside Walney and liberated there made the same migration. The small numbers of flounders dealt with do not justify any attempt to construct the migration paths of this fish, but evidence of an inshore movement in the late spring or early summer appears to be forthcoming. All the flounders recaptured from the last experiment were fish in very fine condition. Without exception, all were feeding greedily on Lamellibranch molluses (Z'ellina serobicularia, Mactra) when recaptured. Experiment 6, 6th March, 1906. Station: Colwyn Bay. Fish caught in Colwyn Bay and in Conway Bay, two hauls. ANALYSIS OF SIZES OF Fisu LIBERATED. LES. MOGI) ea Te) 72) 8 | si) 8s) 8s 9 | OF 0 4 Eni) a Ve la ea ea: lt Un PR ell 1 TICE OEMOUMILOCES, ...0cccccescccsececsecs — | — | = a eA ee EOE MOGS iy oe cocssccscecceneicssesenes a a 2 2 4. 2 2 co (ines) oe 91| 93] 10 | 103] 103] 103] 11 | 114 POPUCREEPUEC EN Seige eco ccsescecnucesacesees — L1};—|— el os TUCRCGIGMIIGCLOUS, ..0..00.0scccccesceceees es em, Se oe Sy el TOES eines ci sce vcvdessceececdeas ele 1 Ih eee 1 1 1 246 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. PARTICULARS OF FisuH RETURNED. LL20 72 LL29 74 LL22 72 LL5 9 Dab LLI1 82 Dab LL37 74 LL44 104 Flounder LL19 84 LL32 Si 7 miles N.W. from Great Orme. Off Great Ormes Head.. Near Cordy Buoy, Dee... Horse Channel, 10 faths. Rock Channel, 3 faths.... Wallasey shore ............ Opposite Lytham, S. side Ribble. Off old Pier, Morecambe South Bay, Wexferd, Treland. 5/11/06} 9 | 83} 1] 17 9/12/06] 10 | 83] 1] 17 29/3/06, 1 |) eae 13/8/06] 6 | 9 | == \tR 11/8/06 6| 9| 4] 2T 26/4/06] 2] 78| 3/SN 19/4/06] 2 | 101] — |B 26/11/06} 9| 93} 3] OT 16/5/06, 2] 83] 4] 2T This experiment did not yield very notable results. None of the dabs or flounders liberated have been recovered so far, and the movements of the plaice which were recaught do not show any uniformity. Hxperiment 10; Station: Off Nelson Buoy. Fish caught off Nelson Buoy. Il2th Jane. 1.3 OGe ANALYSIS OF SIzEs oF E'IsH LIBERATED. 93} 10 | 103| 114] 113 Sia] ENE ee ] 1 LL166 LL173 LL176 LL181 LL195 LL199 LL202 LL203 CO co © Bcobo|=tole No) Birkdale shore ".....2...... 1 mile N.W. from Nelson Buoy, 9 fathoms. 1 mile 8.W. from Nelson Buoy. 2 miles 8.W. from Nelson Buoy. Roosebeck, Morecambe Bay. 12 miles N. from Liver- pool Bar Light Ship, 14 fathoms. Liverpool Bay, 14 faths. Liverpool Bay, 17 faths. 2 miles N.W. from Liver- pool Bar Light Ship, 15 fathoms. 6 miles N.N.W. from Liverpool Bar Light Ship, 3 fathoms. ““Meols Bay,” 14 faths. 12 miles N. from Liver- pool Bar Light Ship, 14 fathoms. 20 miles N.W. from Liverpool Bar Light Ship, 19 fathoms. 10 miles N.N.E. from Morecambe Bay Light Ship. 6 miles 8.S.W. from Morecambe Bay Light Ship. 10 miles S.W. from Morecambe Bay Light Ship. 7 miles S.W. from Morecambe Bay Light Ship. 6 miles N.E. from Morecambe Bay Light Ship. 7 miles S.W. from Morecambe Bay Light Ship. “Morecambe Bay,” 20 fathoms. 12 miles §.S.E. from Maughold Head, 12 fathoms. SEA-FISHERIES LABORATORY. 12/6/06 3/9/06 20/9/06 12/9/06 23/10/06 15/7/06 20/7/06 26/7/06 2/8/06 8/11/06 13/7/06 16/7/06 30/7/06 11/8/06 30/6/06 26/10/06 2/8/06 11/8/06 14/7/06 25/7/06 29/11/06 PARTICULARS OF FisH RETURNED. bo be 14 _— 247 1T Ae ae ae Wat Woe LT st 248 Kxperiment 15, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 9 th. od, layers 1 S0%Gr Station: 5 miles N. from Liverpool Bar Lightship. Fish caught near Nelson Buoy. ANALYSIS OF SiIzES oF Fisu LIBERATED. 7 miles (?) E. from Nelson Buoy, 7 fathoms. Off Nelson Buoy, 9 faths. Off Nelson Buoy, 13 fathoms. 13 miles 8.W. from Nelson Buoy, 94 faths. N.N.W. from Liverpool Bar Light Ship, 17 fathoms. Pillar Buoy, Horse Channel, 9 fathoms. Liverpool Bay, 14 faths. 16 miles N.N.W. from Liverpool Bar Light Ship, 17 fathoms. 12 miles 8.S.W. from Morecambe Bay Light Ship. 5 miles N.E. from Liver- pool N.W. Light Ship, 15 fathoms. 29/7/06 11/9/06 28/9/06 13/9/06 14/8/06 3/8/06 24/7/06 28/10/06 5/11/06 8/9/06 Both Experiments 10 and 15 have given good results, the former shewing 50 per cent. and the latter 20 per cent. of recaptures. They may conveniently be considered together, as the fish were caught on the same ground ; the stations of liberation are close together, and there was only a month between dates of the two experiments. SEA-FISHERIES LABORATORY. QA9 Bearing in mind that the fishes were liberated at about the time of midsummer, we should expect to find, if the results of the experiments already discussed hold good, that an offshore migration would be exhibited. A glance at Chart IV., where the positions of recaptures are roughly plotted, will shew that these experiments do, indeed, confirm the results already obtained. Most of the fishes returned were recaptured during the three months following liberation, that is during the time when we should expect to find the offshore migration in progress. It will be seen that there is practically no alongshore or inshore migration. Only three fishes have entered the territorial waters. No. LL171, from Experiment 10, immediately on being liberated hurried off inshore, and was caught on the same day in a stake net on Birkdale shore. No. LL270, from Experiment 15, also travelled inshore, and was recaught at the entrance to Horse Channel by a second-class trawler. Finally No. LL178, from Experiment 10, went inshore, and was caught off Roosebeck by a second-class trawler. But, with these exceptions, there is a well-marked offshore migration to be observed, the majority of the fishes returned being recaught to the West of the place of liberation, Nelson Buoy. Only one, No. LL205, went far afield, and was recaught by a Douglas steam trawler S.S.E. from Maughold Head. So far as has yet been observed, none of these fishes has made the lengthy migrations of which several instances have been noticed. feereriment il, ldsth June, 1906. Station: Off Pwllheli beach, Tremadoc Bay. Fish caught off Pwllheli beach and off St. Tudwall Islands. 250 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. ANALYSIS OF SIZES oF FisH LIBERATED. SIZESA(in CHES) P...cachameceeee vases soar eee eee 74| 72; 8 | 8h) 84] 82 9 INo sof plaice versie is ee eee AP aa i By oS 7 4) 4 INoof. dloundersr (c.f icc scateee santo tees — |} — | — | — | — | — | — Sizesy(ImeWes) ies nace sae ees eee 91, 93) 10 | 102; 103; 102) 11 Noi of plaice: ecuesmsresc mao oeaaee 3 3.| 2 1 2 1 1 Noi ot fomuders; ssi. (eaees-eee ae eee ee 1};—|—}—}]—}— | — LL217 Se Gimlet Rock, bearing | 19/7/06} 1) 93} #2 1T N.W., distant 7 miles, Tremadoc Bay. LL214 9? 9 miles off the Bailey | 16/10/06| 5 | 103) 1 | — Light Ship, Dublin Bay, 16 fathoms. Experiment 16, 12th July, Boke Station: Off Penkilan. Fish caught off Penkilan. ANALYSIS OF Sizes oF Fisn LIBERATED. Sizes (inches)......... 7 | 7k | 72 | 8 | SE | 8d.) -83°) 9 ORS ose INo: of plaice sa... ce. répa|| ll Loch |b 9-4 1-9" 1S 1 2 3 4 5 | 6.) es LL422 92 2 miles 8.W. from Jumbo | 4/10/06} 3 | 103; #2 | 2T Buoy, Ribble, 7 faths. LL389 8 Red Wharf Bay, 13 faths. | 9/12/06| 6 | 83] 3 | IT SEA-FISHERIES LABORATORY. 251 Experiments 11 and 16 may be considered together, since the times and stations of lberation were much the same. Neither experiment has, apparently, been successful. Last year (1905) several marked plaice were recaught in Tremadoc Bay, and it was thought desirable to fish there and mark a number of fish during the last summer. Accordingly 91 plaice caught near Pwllheli were liberated in June and July, but so far only four of these have been returned. One, No. LL217, was recaught in almost the same place where liberated, but the other three have made rather long journeys. One was caught in Dublin Bay about five months afterwards, having crossed the deep water of the Irish Channel, and two came North into Lancashire waters, one being recaught in Red Wharf Bay and the other in the Ribble Estuary. These two latter cases and another are the only instances noticed so far of plaice coming North from the Welsh Bays into Liverpool Bay, though the reverse migratioa has been observed many times already. This paucity of recaptures is not to be attributed to the fact that the amount of fishing in Cardigan Bay has been less than usual. Capt. David Pritchard, the Head Bailiff at Pwllheli, writes me as follows:—“In my opinion, plaice have shifted for a time from the usual fishing ground in Tremadoc and Cardigan Bays. Our fleet of 15 small trawlers have been fishing at Tremadoc Bay and at Kilan Grounds, and only one marked plaice has been landed here. It is true that there were only two Southport trawlers in our bay last summer (1906), as against 22 the year before, but the plaice, turbot and brill were very scarce last summer (1906). There have been several large trawlers at work in Cardigan Bay during the last two months, landing their fish at Pwllheli, but a very small quantity of plaice were 252 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. landed here, and no marked ones. There has been a fair percentage of soles, but hardly any plaice to compare with former years.” I think, then, the cause of the apparent failure of these experiments is that a dispersal of the plaice present in Tremadoc Bay in June and July has taken place. Experiment 12, 14th June, 19s Station: 2} miles off Llanrhystyd. Fish caught from New Quay to Aberaron. ANALYSIS OF SIZES OF FIsH LIBERATED. Sizes) (unehes) seseereeenece Td | 74 | 72 | 8 | 8£ | 8h | 82) 9) OF noe INO ot iplaice wy esses L | 2°) 3) 4:°) 4S Fy) eae ees ING. tobsbrilll’) a kecsenes ee INGsof das” eee ee Se ee eS Se re Sizes (imehes)!e..2..seecce 93 | 10 | 104; 103) 11 | 114) 113) 112) 123) 122 ING Of plaice yes. scree Boy 2 PT ae | 2) Oe No 4of Sorilll © Pics cSeate eee: —}|—|;—};—}]1 }—)};—]—)2 | 1 INO: tof tdabs.ncescp eases. —}—}—}—J;—]f—}]—J]—}—] — 1 2 3 4 5, | 6. | tee LL249 11 Off Llanrhystyd ......... 11/9/06; 3 | 114; 4 | 2T LL329 81 Between Aberystwyth | 24/7/06; 2] 9| # | 2T and Llanon, 4 mile from shore. LL335 9 Near Dlanon 220.2. aac rn. 29/7/06} 2; 92 | 4] 2T LL338 72 Near Tilanon <-gcamnceteser 19/6/06; 1 | 72 | —|1T It will be seen that the plaice recovered from this experiment were all caught quite near to the place where liberated and within the territorial waters. One was recaught by the Aberystwyth first class trawler AB71, and the others by the Southport second class trawler LL34o. SEA-FISHERIES LABORATORY. 2538 Heaperiment 14, 16th June, 1906. Station: Ynys Fach, Cardigan Bay. Fish caught off Aberporth Bay. ANALYSIS OF S1zES oF FIsu LIBERATED. Se (UG eS) | ee Tx | 72 | 8 | 8419 | 9F | 92 | 10) I3 MGR RDIAICE Foo. ce cinta ceoenn ss 2 aval Ae cli athe re lp lcm a licence! 2iGe CL CEOS S6c aaa eae eae —/|—;—;—] 1 |—j|—}—] — PaRTIcULARS OF FisH RETURNED. 1 2 3 4. OF |enOv emalanl Ss. LL378 84 Newport Bay ............ Wi OG\ Lae Scale tee eT tpaperament 13, 16th June, 1906. Station: 2 miles H.N.E. from Dinas Head. Fish caught off Dinas Head. ANALYSIS OF SizEs oF FisuH LIBERATED. Sizes (inches) | 8} | 9 | 103) 11 | 113] 12 | 123] 123) 129] 13 | 133] 14 | | No. of plaice | 1 ] Lo eo ae ASP Salome roam ocimnle ol i) PARTICULARS OF FisH RETURNED. 1 2 3 4 Ss) aS i a a a | ee | | |. | LL359 12 Off New Quay Head, | 23/10/06) 5 12 | — | 1T Cardigan Bay. LL350 123 Milford Haven, Close to | 1/11/06} 1 133| 14 | 2T Milford Pier. LL361 123 9 miles S.W. from South | 18/11/06) 6 | — | — | ST Bishop. Experiments 13 and 14 were made in the Milford Haven Sea Fishery District during a police visit to those 254 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. waters by the “ John Fell.” It was intended to carry out a somewhat extensive fish-marking experiment on this cruise, but a report of poaching by a steam trawler (which was detected) compelled Capt. Wignall to change our proposed plans. The recaptures reported shew no unusual features. They were mostly made South of the places of liberation. Fishing there is, of course, more extensive than to the immediate North. Experiment 17, 19th) Septem bem LOG. : Station: Red Wharf Bay. Fish caught in Red Wharf Bay. ANALYSIS OF SIZES oF Fisu LIBERATED. Sizes. (inelies)) us wesaseeaen ees eeeaeases 7 | 7) 8 | 8F} 84] 9 | 94 | 9F wale susiele sia SaaeC ee eeteneetee ] 2 1 1 Ossie 1 SIZES) (INCHES) hye sehen kee eee aie 10 | 104) 103) 102) 11 | 11}) 112) 133 INO: Ol sDlaICE.n eo senaceo eee ceeto me 8 I 2 ] 2) | 4a 2 1 2 3 4 5 | 6 stags LL439 134 Off Great Ormes Head, | 29/9/06} 1 | 133; — | 2T 5 fathoms. LL451 11 Red Wharf Bay, 12 faths.| 11/12/06} 3 | 114; 4 1T 1.1454 10 Red Wharf Bay, 12 faths.| 25/11/06) 2 | — | — | iT LL460 10 Red Wharf Bay,6-7 faths.| 7/10/06; 1 | 10 | — } IT LL467 81 | Red Wharf Bay, 7 faths. | 7/10/06) 1 | 84| — | IT LL474 81 | Red Wharf Bay............ 9/10/06} 1 81; — | 1T LL476 + 8 Mostyn Deep; Dee. =2.2-- 23/10/06) 1 4} 4) 2T LL477 81 4 miles N. from Puffin | 23/10/06; 1 84; 4 1T Island. SEA-FISHERIES LABORATORY. £55 It will be seen that quite a number of recaptures were made shortly after the date of this experiment. I expected that a large proportion of these fishes would be recaught, but after the second month none has been caught. The cause is probably the wild weather of November and December, which has not only affected the fishing, but has also probably led to considerable shifting of the fishes normally present on the fishing grounds. We find that heavy gales have this effect on the shallow water fishing grounds on the West Coast of England. Meamemmment 18, dsrd October, 1906. Station: Luce Bay. Fish caught in Luce Bay. ANALYSIS OF SizEs oF FIsH LIBERATED. S288, (NCES) 65a eee 84 | OF | 114) 1145; 113) 12 | 124 PM PRCE INCE EMER ons s el dassacdecseceddeasenes 1 1 1 i Li orl ee “LEGS; (TOClIVGS)) 65530 CReseeee eee ere 124] 123) 13 | 134) 133] 133) 14 RECON LANC EMD clctas cals cedewevecscescsesesees By Na let teh ap Oo AL 1 PARTICULARS OF FisH CauGHtT. 1 2 3 4 Outen s| mo LL506 | 123 Luce Bay, off Chapel- | 11/10/06) 1 123} — | GN rossen, 6 fathoms. This experiment was made while trawling in Luce Bay for spawning plaice for Piel Hatchery. 9256 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. INTENSITY OF FISHING. The Summary Table shews that about 19 per cent. of the plaice and 19 per cent. of all the fishes lberated during the year have been recovered. Of course, several of the experiments were made late in the season, and many more recaptures will doubtless be made. A considerable number of dabs were also marked and liberated, and these have given poor results. The individual experiments vary greatly in their numerical results. Experiment 10, for instance, gives 50 per cent. of returns for six months’ fishing only, while Experiment 7 for nine months’ fishing gives only 9 per cent. of recaptures. Many factors influence the numerical result of these fish-marking experiments. In Experiment 10 the fish had not apparently become widely dispersed, and were, moreover, liberated at a place which is situated near the widely-frequented fishing ground lying between Liverpool North-West and Morecambe Bay Lightships. Experiment 7 failed probably because the fish marked were in poor condition, and had not been able to survive the transference from tank to tank and the subsequent marking operation. Again, Experiments 11 and 16 were apparently unsuccessful because, for some reason or other, the fish marked have probably become widely dispersed, possibly into areas where there is at present little or no plaice fishing being carried on. Premising, then, that by “ Intensity of fishing” is meant only a very rough approximation to the extent to which the plaice population of the West English seaboard is being exploited, and that for even an approximate estimate of this value much more extensive marking experiments than we have made would be required, I give the figures in the last column of the Summary as representing these approximations. SEA-FISHERIES LABORATORY. 257 INFLUENCE OF DIFFERENT KiInpDs oF FISHING. It was not always possible to obtain information as to the method of fishing by means of which the marked fishes were recaught. The following lst has been compiled from the tables of particulars of fish recaught :—— Method of Fishing. No. of Marked Fish : Returned. Pers eSUIAG CEAWICTS, ......020..2s00ee0eeeeec cece 64 Pramclassesailime trawlers. .......c0.cccceceeseeseeeeess 37 AL2E UGS)... ocho Ags oe 23 Wier MAE CUS EO oon feo nae clas t\ctneseceasccces veces 16 Re PM EEE conc cccnte pos cotscedededddcesesveleeleota nea Z SM ce Scie o0is ss ainls Fans oe x cass voice vns.drsie sins 7 ‘Set nets,” ‘* trammels,” “ tees,” lines, salmon 5 nets. 8 Information not given. It will be noticed that fishing by means of first class trawlers (smacks) apparently predominates in the “ home erounds ” of the Irish Sea. The proportions between the various methods of fishing by means of which the marked fishes have been recaught are almost exactly those compiled from the experiments of 1905. RaTE oF GROWTH OF PLAICE IN THE IRISH SEA. In attempting to deduce the rate of growth of plaice from the marking experiments, two series of figures are made use of—(1) those indicating the increase in length of the marked fish which were set free before the beginning of the season during which growth takes place, that is April-September. The defect in this series is the small number of recaptures during the latter half of the year. It has been found during the two last years that even if a fairly large number of marked fishes have been liberated before the end of March, quite a small proportion will be recaught during the autumn and winter. One S 258 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. cause is probably the decrease in the intensity of the plaice-fishery during the months of September-December. Marked plaice are usually recaught by sailing trawlers, and the unfavourable weather usually experienced during October to December is prejudicial to the fishery. It will be seen from the statistics of plaice landed in the Lancashire and Western Fisheries District that there is an undoubted falling off in the intensity of the plaice fishery during those months. fishes are recaught. The following table is compiled from the results of the experiments of 1905 and 1906 :— Consequently, fewer marked Rate oF GrowtH or MarkEeD FisHes rrom MontH To Montu. Month No. of Fishes Average Increase in Recaught. Length. VAMUALY | Seen ccoskens: 45 0°04 inches (071 cm.) IHDEURIV aenccemacecoe 22 004 ., (Gl cn Mcrreli taste ectnan 15 OV]. > (Asem) PSSOYAL Sacra teenies coslenes 21 0-22 , (Oogenme BY ciiecitnisiavstioe we-toisee 27 0°53 (1°34 cm.) UNG hor ax' Ses ses rrr oe ee 18 0-92 3» (2:35 ems) SULLY Ae acrausienerecescm cee 24 Ley » (4°33 cm.) SUID USE rece cuss n 16 1-7 » (4°33 cm.) September 13 2°44 .,, (6°12 ems) Octoher cds.,Aceses 3 2°4 >» (6 *L2vems) INovemlber.:..csss-c5- a 231. .», (On venm WEcemibers | j.-hesc.ere — — —— The results are represented graphically in Fig. 8. It will be seen from the table and chart that the growth during January, February and March is practically nz. Indeed, the months October, November and December are also to be included, since a large number of the fishes included in the table for January were liberated in the preceding October and November of both years, and some were recaught during those months. Cents. Inches. SEA-FISHERIES LABORATORY. on SP N) fan) ‘Oo Fig. 8. CN = Curve of growth of marked plaice. 260 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. It was only in a very few cases that any increase in length was detected in fishes liberated during October- December and recaught in January. In April the season’s growth begins, and this is most rapid during the months June, July and August. It will be seen that the increase in length during August was apparently nd. That is the average length of the marked fishes returned during that month (and which had been in the sea during the whole season) was apparently no greater than those returned during July. I am quite certain, however, that this is only apparent, and that the fishes received in the laboratory during August were uniformly under- measured. The measurements were made by a laboratory assistant during my absence. It is, indeed, not usually a simple affair to measure a marked plaice sent by post. The fish is often dry, and has to be relaxed by immersion in water for some hours. Then a dead plaice is always shorter than a living one (probably because of the contraction or compression of the inter-vertebral discs). This can be corrected by slightly stretching the fish, and the contraction usually varies from 0°5 to 1 cm. according to the size of the fish. It is, however, quite legitimate to “smooth” the curve, which then shows what is probably a little less than the normal rate of increase in length of plaice from month to month throughout the year. In October growth practically ceases. Plaice during the months of November-January usually have very little food in their stomachs, and many are entirely empty during December and January. During those months the weight of the fish decreases. Altogether the metabolism of the animal is greatly lessened. | The annual rate of increase in length as shewn by the curve is, therefore, about 2} inches. The annual SEA-FISHERIES LABORATORY. 261 growth has, however, been measured in another way. Quite a number of marked plaice have been recovered which have experienced a whole season’s growth, regarding the growth season as ending at the end of September, and the particulars of growth of these are tabulated as follows :— PARTICULARS OF FISHES WHICH HAVE UNDERGONE ONE orn Morr CoMPLETE SEASONS’ GROWTH. Date when liberated. L104 12/11/04 hV5s2 12/11/04 L242 18/11/04 L252 18/11/04 L287 18/11/04 L288 18/11/04 L294 18/11/04 L341 13/11/04 L345 13/11/04 L444 21/1/05 L505 17/3/05 L522 17/3/05 L528 6/7/05 L541 6/7/05 L587 12/7/05 L713 1/2/06 L716 1/2/06 L721 1/2/06 L760 19/2/06 L762 19/2/06 L848 22/7/05 L904 26/10/05 Ly38 26/10/05 LL19 6/3/06 LL20 6/3/06 LL29 6/3/06 LL104 31/3/06 Date when recaught. 12/11/06 3/12/05 7/2/06 28/2/06 12/11/06 4/9/06 3/10/05 28/10/05 3/11/05 19/10/05 7/12/05 16/11/05 10/7/06 17/9/06 7/7/06 21/9/06 13/11/06 30/9/06 28/11/06 28/11/06 26/9/06 26/9/06 27/9/06 26/11/06 5/11/06 9/12/06 23/11/06 Increase in size (inches). (2 seasons’ growth). (2 seasons’ growth). (nearly 2 seasons’ growth). So) GN) CULO OU (over 1 season’s growth). Oo a Or Or SP Orns we H AIS ADTSOONW OSNAITIAW KAO w 3) NK PON WWNWNWNHETRWNWWNWH ADH FB OA fom) ~~ Average: 3°01 inches (= 7°6 cms.). Several fishes exhibiting a complete season’s growth have been received since the above table was compiled. The results do not, however, alter the general growth rate already deduced. Twenty-seven fishes are represented, and this is 262 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. probably a sufficient number to yield a fair average. In calculating this, however, the total increase has been divided by 29 instead of 27, since two of the fishes have undergone two seasons’ growth. One has slightly over one season’s growth, but this may be neglected. The average thus obtained is almost exactly three inches. This is rather more than the result given by the former table, but it must be remembered that the latter probably under-estimates the rate of growth. If a larger number of marked fishes had been recovered in September- November, the growth would no doubt have been greater. But it is also probable that the results of the second table slightly over-estimate the year’s growth. The fishes represented have all been in the sea for over the average length of time between marking and recapture. They are, therefore, probably more vigorous fish than the others, and may have grown more rapidly. Their average initial length was also a little more than the others. At any rate the difference is not great, and one may conclude that in the Irish Sea plaice grow about 23 inches in the year. This applies to fish which are initially of the ordinary smaller marketable sizes, viz., 8 to 10 inches. It should be noted, too, that considerable variation in growth rate exists. Thus plaice No. LL19, after a whole season’s growth, had increased only ?-inch in length. On the other hand plaice No. L152, after a season’s growth, had increased in length 54 inches. Both cases are of course extremes, and are quite abnormal. The otoliths, or earstones, of about half the marked plaice recovered have been examined, with the object of determining the ages of the fishes. It is well known that the calcareous matter in these structures is laid down regularly, so that every year after the first, two distinct SEA-FISHERIES LABORATORY. 263 rings an opaque zone and a translucent zone are added to the otolith. By counting the number of opaque rings, it it possible to arrange the fishes in the groups O, L., IL., III. and IV. according to the number of these zones outside the dark nucleus of the otolith. Of the total number of marked plaice returned 66 have been examined in this way, and may be grouped as follows :— O Group (in the first year of life)... iB peal ieee, | ;,, second, ,, tee «6(Cs|.:«Cthird «4, ,, ieee, ( ,, tourth;, ,, Wee | «5, ffith ,, ,, The numbers examined are, of course, much too Se ee Ne e (ws) small to enable a satisfactory estimate of the size of the fishes at each year to be made. I give the averages calculated for what they are worth :— Females in Group II1., average length = 9-3 inches. 99 BS) IIf., ” 9 = ee om) oe) ” IV., ” oy) = 14 ” Fisu CauGcut 1N Extra-TERRITORIAL AND INTRA- TERRITORIAL WATERS. There were almost exactly as many marked fish recaught outside as in the territorial waters. Such a statement possesses, however, no significance since, if it is the case that an offshore migration takes place in the summer months and an inshore and alongshore migration in the winter months, it obviously follows that the numbers of marked fishes caught inside and outside the territorial limits depends on the time of year at which most of the marked fishes were hberated. If we mean by “winter” the months October to March, and by “summer” the months April to September, we then 264 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. find that 613 plaice were liberated in the “ winter” months of 1904-5, and 217 were liberated during the “summer” months. During the year 1905 about 72 per cent. of the fishes recovered were recaught within territorial waters, and about 28 per cent. were caught outside the territorial limits. Thus the result of these experiments, in which nearly three times as many fishes were liberated during the winter months as during the summer, is that nearly three times as many fish were caught within the territorial as without. On the other hand, in 1905-6, 290 plaice and flounders were liberated in the winter months and 354 plaice and flounders in the summer months, and we find that in these experiments, when the liberations during the two seasons were not far from being equal in number, the number of fishes recaught outside is very nearly equal to those recaught inside the territorial waters. With regard to the size of the fishes recaught, these have not so far been tabulated so as to bring out any relation between depth of water and length of fish. It will be better to let these observations accumulate, and then make this analysis when quite a large number of marked fishes have been recovered. Generally speaking, fishes which at the time of marking and lberation were the largest have travelled furthest. Large fishes have, of course, more vitality, and it is undoubtedly the case (with certain well-known exceptions) that the plaice caught outside territorial waters are larger on the average than those caught inside. But as regards the proportion of fishes caught inside as compared with those caught outside the technical territorial water limit, the main factor is the opposing offshore and inshore migrations, which depend more on the seasons than on the mere size of the plaice. SEA-FISHERIES LABORATORY. 265 GENERAL CONCLUSIONS. i—Percentagze of fish recovered. This, as the Summary Table shews, varies from 50 per cent. to 4 per cent. in the case of plaice, taking each experiment by itself. The causes of the difference in the percentage of fishes recorded are (1) the intensity of fishing, as for example in the case of Experiment 10, where an active fishery was carried on during the summer months over the area immediately contiguous to the place of liberation; (2) on the method of dispersal of the marked fishes, as for instance in Experiments 11 and 16, where the marked fishes liberated have probably been widely dispersed into areas where little trawl fishing is carried on; and (3) on the vitality of the marked fishes, as for instance in Experiment 5, where (as in the case of Experiment 12 of 1905) plaice were marked which had been for many months kept in tanks, and were in poor condition. 2—Influence of methods of fishing. First-class sailing trawlers have recaught more marked plaice than any other class of vessel or fishing method. There is little doubt that in the Lancashire and North Welsh Fishing Grounds this method of trawling predominates, at least for the “home waters.’’- The steam trawlers have caught fewer fishes, but it is well known that these vessels go much further afield and do not frequent the grounds where the marked fishes may be expected to be recaught to the same extent that the smacks do. 3.—Rate of growth. The estimates of the rate of growth of marked fishes constructed on the results of the experiments of 1906 agree 966 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY, well with those of 1905. Plaice practically do not grow at all during the months October to March. At the end of the latter month growth begins. During the months noted, any apparent increase in size of the plaice returned is probably due as much to errors in measurement as to actual growth. At the end of March we begin to notice an increase in length, and during April, May and June the fish steadily increase in length. During July and August the growth is most rapid, and during September it begins to fall off, and in October the plaice have ceased to grow. An estimate of the rate of growth based on the study of a curve constructed from these monthly incre- ments of growth gives us a value of about 24 inches (6°3 centimetres) as the yearly growth rate of the plaice in the waters of the Irish Sea East of the Isle of Man and adjoining the coasts of Lancashire, Cheshire and North Wales. But when the increments of growth indicated by the fishes which have been recovered after one or more years’ sojourn in the sea are tabulated, the average growth rate works out at almost exactly 3 inches (7°6 centimetres), A sufficient number of fishes have been recaught, after being about a year in the sea, to render this estimate a very probable one. At the same time it should be noted that these are the larger and more vigorous fishes (as is indicated by their more lengthy migrations), and that they, therefore, grow perhaps more rapidly than the others which have remained closer to their original habitats. The cessation of growth in the colder months of the year is not necessarily connected in any way with the spawning habits of the fishes. The great majority of the marked fishes recaptured were immature fishes, and one cannot, therefore, attribute the cessation in growth in the SEA-FISHERIES LABORATORY. 267 winter to the maturation of the reproductive organs. There is undoubtedly a decrease in the metabolism of the fish during the cold weather. It does not feed, or does so to a very slight extent, during the months of December and January, and the weight of a plaice of a certain length is always less in the winter than the weight of a fish of the same length in the summer. 4—The migrations. It should be noticed that many instances of quite exceptional migrations are recorded in the tables. Thus fishes liberated off the coast of Lancashire have been recaptured off the Hast and South Coasts of Ireland, and fishes liberated in the same area have also been recaught at the mouth of the Bristol Channel. These lengthy migrations would not surprise us if they were made by actively growing fishes like the cod or hake, or pelagic fishes like the mackerel, but one is accustomed to speak of the plaice as a semi-sedentary fish. Leaving aside these exceptional migrations, the results of this and last year’s experiments shew with some probability that plaice in our waters do not move about in the winter to the same extent that they do in the summer, and that the winter migrations are mostly alongshore ones, with perhaps a general trend to the North along the coasts of Cheshire and Lancashire. In the summer, on the other hand, the migration is an offshore one. There are evidences of a tendency to the southward, and in the exceptionally lengthy migrations already referred to, it is generally this southerly migration that is made. While plaice have been observed to travel from the coasts of Lancashire and North Wales into Tremadoc and Cardigan Bays, the opposite migration has only been observed in two instances. 968 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.: It should also be noted that plaice are not of necessity restricted to comparatively shallow waters. The opinion of most fishermen and others is that outside the 20-fathom contour line plaice are hardly to be found, and no doubt this is largely true. But the fish does migrate, at least, through waters of much greater depth than this, for we have found that they may cross the Irish Channel, which nowhere has a depth of less than about 50 fathoms, and one plaice (L541, Experiment 14, 1905) was actually caught by a steam trawler in water of 57 fathoms W.S.W. from the Smalls Light. Evidence that the marking operation, if carried out carefully on a vigorous plaice, has no effects which are prejudicial to the normal movements and growth of the fish is afforded by several plaice which have been recaught after a considerable lapse of time. No. L104 was taken after exactly two years had elapsed since the time of lberation: this fish had grown 74 inches. No. L287, too, was recaptured after being almost exactly two years in the sea: it had grown 64 inches; and No. L288 was also retaken after very nearly the same interval, and was 64 inches larger than when marked. All these fishes passed through my hands, and their condition was that of normal well-nourished fishes, while the wound caused by the afixed mark was clean and not much larger than when initially made. Then quite a number of fishes have been returned after having been in the sea for periods of from 9 to 15 months, and with few exceptions normal rates of growth were exhibited. CHART | IMENT 22-1905. rcles indicate positions where the ere liberated. circles indicate the approximate positions CHART | St Bees Head, y EXPERIMENT 22 - 1905. y GY, Large circles indicate positions where the fishes were liberated. pel Circles indicate the approximate positions UM where the fishes were recaptured. m2 Numbers within the small circles indicate months between liberation and recapture. hold rege ood Thin lines indicate probable winter migration. Thick lines indicate probable (O) summer migration. Y Blackpool Y i 4, i stAnnes Y Hy Lytha ‘ { / © © i) y ee (©) f ; DY ff pea IR SS ee ee ee ae, “ D ee a. Ternitorien... Ware, y Hoylake U, © / Anglesey “e ; ia sp .-~, | Fe | ~ Sie - ae | r | i ® | a f ce hy iyi? ; Ry $ ie »- ae | ' ite hs t \ ( eg Ne ne ae eee CHART } ERIMENTS 1.6.0 2,3.0 ge circles indicate positions where the es were liberated. mall circles indicate the approximate position CHartIl ‘St Bees Head, “% EXPERIMENTS 1,6.01 2,3.0 Gy Large circles indicate positions where the Ny fies were liberated, wpe circles indicate the approximate positions = lyprere the fishes were recaptured. Vj y Numbers within the small circles indicate Y, StAnnes ~ O Lytha Formby Point OY UY See o=e © Iw a rd [6] we Wang ee y GY Jf iy [2] UY Yy Uj, Yy or [8] neh q Yi Liverpool Uj Yyy SS Srirorial /_ W ap : Hoylake YM), UY prdcritorts <2 pK , y Y Y So Lg eS Be mY py Uy iy Jo S », « Wy, Y Ly, Yj Pp Sey ’ YY | i d 3 Anglesey q yp 9 Yy Yj Ye $ MENT 6. EXPERIMENT 1. EXPERIMENT 2. ; F Coast, Ireland [32 @ South Bay. Wexford. Ireland. L709 @ Holyhead Harbour L754 @ Between Barrels &Saltese Lightships, S,Coast, : L726 © Off Llanon L762 @ North Bay, Co.Wexford. Ireland. oe SS. | } CHART III IMENTS 5,7,8,89. ircles indicate positions where the ere liberated. circles indicate the approximate nositinns CHART III >! Bees Head, Large circles indicate positions where the fishes were liberated, py, omall circles indicate the approximate positions Uff where the fishes were recaptured. Numbers within the small Circles indicate months between liberation and recapture. a Flounders (©) augno ISLE 2 ua Ngo UE 8 Q) aman | Y © CHARTIV IMENTS 10, 15, & 17. circles indicate positions where the were liberated. | | circles indicate the approximate positions lH a CuHartlV ‘S! Bees Head. y, EXPERIMENTS 10,15, & 17. Yy Large circles indicate positions where the fishes were liberated, _yomall circles indicate the approximate positions Yyjwhere the fishes were recaptured. ) Numbers within the small circles indicate lf months between liberation and recapture. Vj, fever fll ‘egy Ly, oof aa p & YU Ve SY, Maughold Head — pec NR Anglesey i oe oie. ¢ om SEA-FISHERIES LABORATORY. 269 EXPLANATION OF THE CHARTS. The charts are to be regarded as exhibiting objective representations of the migrations of the fishes. Except in Chart lit has not been attempted to express synoptically these migrations. Probably the accumulation of several years’ results will enable this to be done. In the meantime it is best to indicate the facts only. The lines connecting the stations of liberation with the places of recovery do not, of course, necessarily indicate the migration paths. It was often difficult to be sure of the exact position of recapture. Depth of water, for instance, as given on an Admiralty chart, often does not agree with the recorded position of recapture. It is perhaps nearly always the case that there may be an error of from one to several miles in the recorded place of recapture, since a fish may be caught at any point of a haul (which may be from 2 to 24 miles in length). 270 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. INTERNAL PARASITES AND DISEASED CONDITIONS OF FISHES. By Jas. JOHNSTONE. 1. CESTODA. 2. TREMATODA. 3. PROTOZOA. 4. CATARRHAL CONDITIONS IN DAB AND SALMON PARR. I.—CESTODA. Abothrium rugosum (Goeze). From Gadus callarias. This is Bothriocephalus rugosus (Goeze) Rudolphi = van Beneden’s Abothrium gadt. About a dozen large cod were dissected last winter, and this cestode was invariably found. Sometimes there were as many as a dozen large worms in each fish. The head of each cestode is implanted in a pyloric caecum, in such a manner that it is impossible to extricate it. I repeatedly dissected these structures with the greatest care, but was never able to find anything resembling a typical bothriocephaline scolex and I do not think that this structure exists in the mature stages of the worm. A portion of the anterior end of the strobila is buried up in a caecum and when the walls of the latter are picked away bit by bit with dissecting needles all that remains is a contorted, horny or waxy-looking, thick filament. The walls of the caecum undergo profound change and become semi-transparent and waxy, sometimes horny, in nature. Sometimes the anterior end of the cestode has perforated the lateral wall of the caecum and lies outside the latter as a contorted kind of cord. It is possible to pick away this investment and then the greatly con- SEA-FISHERIES LABORATORY. 271 tracted strobila is seen inside, but without any trace of segmentation. As one attempts to dissect out the latter one finds that it gradually becomes fused with the sur- rounding waxy tissue which is probably derived from the caecum, and invariably the structure breaks. Von Linstow* describes the worm as having a pseudo-scolex with two slightly developed sucking grooves and figures such a head, from the intestine of Lota vulgaris, as a normal structure. Probably in young codling, recently infected, a stage of the cestode with such a scolex might be found but doubtless with increasing age the changes mentioned above occur, and the normal structure of the head disappears. | The lumen of the gut immediately behind the stomach may at times be almost blocked by the strobilae of these cestodes. The largest specimen found was 85 cm. in total length and about 8 mm. in breadth at its widest part. This worm was, however, incomplete. The older proglottides contained fully developed oncosphere larvae belonging to a later stage than Schauinsland’s Fig. 8. (Bronn, Thier-reich, Bd. 4, 1 B, Pl. LVITI, Fig. 8.) These larvae have a fully developed mantle. They are from 90 to 120 4% in diameter. The undeveloped eggs from the less ripe proglottides are much smaller, and are about 30 u in diameter. Echinobothrium affine, Diesing. From Raia clavata, Shoals, 1906. A single specimen of a small cestode, preserved from the contents of the spiral valve of a large thornback ray, appears to belong to this species. The worm, however, differs in certain respects from both Hchinobothrium typus and /. affine. Fig. 9 represents the scolex, neck and the * Arch, f. Naturgesch., 54 Jahrg. 1888, Bd. I. 272 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. first few proglottides, and Fig.11a part of the neck with some typical spines. Measurements from this single specimen are ;— Fia. 10. Hchinobothriwm affine, Diesing. Spines on neck. x 300 dia. Fic.9. Hchinobothrium affine, Diesing. Head and part of strobila. x 44 dia. Length of head: 13 mm. Breadth of head: 0°36 mm. Length of a spine from the neck: 01 mm. Breadth of a spine from the neck: 0°05 mm. SEA-FISHERIES LABORATORY. 273 A notable difference from the descriptions of either of the above specimens is the absence of coronal hooks. In both Z. typus and E. affine there are two groups of long, slightly-curved hooks on the two muscular lobes of the scolex. In my specimen no trace of these was seen. I think it probable, however, that these spines, or hooks, have been lost in detaching the cestode from the walls of the intestine. Very distinct indications of a musculature which might easily serve for producing movements of the coronal spines are visible. The neck is long and the spines there are well shown. Four longitudinal rows can be seen when the worm is slightly flattened out. These spines differ slightly, however, from the figures of van Beneden,* or Wagener.t The summit of each hook (Fig. 10) is triradiate, these transverse pieces being bent or slightly twisted. The shaft of the spine itself is very slightly curved. Calliobothrium eschrichtii, van Beneden. From Mustelus vulgaris, Llandudno Bay, 1906. A small male Mustelus examined had numerous cestodes on the walls of the spiral valve. Each strobila was about 8 mm. to 1 em. in total length and consisted of comparatively few (about half-a-dozen) proglottides. In addition to these strobilae there were very many detached proglottides in the lumen of the large bowel, most of which belonged presumably to the cestode referred to here. Measurements are :— Length of strobila: 8 mm. to 10 mm. Length of terminal proglottis: about 3°5 mm. Length of first distinct proglottis: 0°6 mm. Length of scolex: 1°2 mm. Breadth of scolex: 1 mm. Greatest length of hooks: 0°08 mm. * Mem. sur les Vers Intestinaux, 1858; pl. 19. + See Bronn’s Thier-reich, Bd. 4, 1 B, Taf. x1., figser, My 274 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. The neck is very short. The whole strobila immediately breaks up on preservation in formalin. Fig. 11s represents the scolex and fig. 11A a pair of hooks. I find the size and appearance of the accessory : oe Fic. 11. Calliobothriwm eschrichtu. A—Hooks, x 575; B—Scolex, x 465 dia. sucker at the summit of the scolex differs somewhat from van Beneden’s figure 3*, but the precise appearance of cestode worms when preserved varies so much that the * Fauna littorale de Belgique. Vers Cestoides, pl. xix. SEA-FISHERIES LABORATORY. 275 differences are perhaps to be attributed to the action of the preservative. The hooks are large and very notice- able. They are not bifurcated, but he in pairs with their broad bases in close contact. One is only slightly curved, but the other is strongly bent. Delicate focussing shews that these structures are hollow. Anthobothrium musteli, van Beneden.* From Mustelus vulgaris, Llandudno Bay, 1906. About six specimens of a cestode which appears to be the above species were found in the large intestine of a small Mustelus. he characters differ slightly from those Fria. 12. Anthobothriawm musteli. Scolex. x 46 dia. given by van Beneden, so I add a description and figure. The measurements of the worm are :— Length of longest strobila (incomplete): 3 mm. Diameter of scolex: 1°3 mm. Diameter of a bothrium: 1°3 mm. Diameter of auxiliary sucker: 0-1 mm. Length of a free proglottis: 6 mm. Breadth of a free proglottis: 2°5 mm. * Vers Cestoides, p. 126, pl. 7. 276 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. The seolex, which is represented in fig. 12 is large and very regular in shape, suggesting a four-petaled flower. There is no myzorhynchus. There are four long mobile pedicels, each of which carries a shallow cup- shaped bothrium—this is never trumpet-shaped. The internal margins of the bothria have thickened rims with a notch in the middle, but the external margins are very thin. On the internal margin of each bothrium is a small auxiliary sucker, which is not conspicuous and may easily be overlooked. In the centre of each bothrium is an irregular rosette-shaped patch, which appears to represent a radial arrangement of muscle bands, such as is represented in van Beneden’s figure 3, but the precise disposition of the muscle bundles shown there does not appear in my specimens. Round this is an annular band of muscles. Tetrarhynchus erinaceus, van Beneden. An interesting addition to the intermediate hosts of this tapeworm is the Halibut, Hzppoglossus vulgaris. Two specimens of pieces of halibut flesh were sent to this laboratory from the Board of Agriculture and Fisheries. In one case the flesh was abundantly infested with the plerocercoid larvae of the cestode, and in the other case a similar infection had taken place, but the larvae were restricted to the muscles round the vertebral column. The cysts containing larvae were unusually large, and were usually present in tubular cavities in the muscle tisswe. Many larvae were in process of disintegration, and in some cases the cyst contained nothing but a mass of calcareous granules. Usually plerocercoid larvae of I’. erinaceus are adherent to the peritoneum and projecting into the body cavity, and the general infection of the flesh is apparently a rare condition. SEA-FISHERIES LABORATORY. OAT Th 2.—TREMATODA. Distomum ocreatum, Molin. From stomach of Conger vulgaris; top end of “ Hole ” (nearly midway between Douglas and Fleetwood). PHARYNX | WFP INTESTINE SF) TESTIS eT A-UTERUS SS SiNGeESiING Fic. 138. Distomum ocreatum. x 18 dia. 278 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. In the caecal part of the stomach of a conger eel about five feet long over 100 specimens of this distomid were found. The worms while alive were blood-red in colour. ‘The size was variable: when dead after killing in fresh water they were from 5 mm. to about 2°5 mm. in length. The anterior extremity in this state is usually bent ventrally towards the ventral sucker. The following measurements relate to a specimen which had been killed in an expanded condition by slight pressure between two glass slides. Total length: 8 mm. Greatest breadth: 2°25 mm. Diameter of oral sucker: 0°88 mm. Diameter of ventral sucker: 0°92 mm. Diameters of ova: 0:024 x 0:013 mm. The species is, doubtless, near /zstomum ocreatum of Molin, but the characters of the appendiculate Distomids with suckers of nearly equal size do not appear to be very well marked, so I add the following description. The suckers are very nearly equal in size, the ventral being usually only very slightly the larger of the two. ‘The mouth is sub-terminal and lying very near to the pharynx. There is no distinct oesophagus and the intestine passes transversely across the body without any distinct fork. In life the rhythmical movement of this transverse portion of the intestine is very well marked. Successive peristaltic movements pass outwards from the junction of intestine and pharynx, towards the lateral curves of the former with great regularity, and the food contents are throughout the first half of the length of each intestinal ramus in a state of constant agitation. The intestinal rami do not descend into the appendix—at. least not in the specimen figured: in other specimens, however, the opposite appeared to be the case. The SEA-FISHERIES LABORATORY. 279 appendix is, at the greatest, about one-third of the entire length of the animal. It is very retractile and easily ruptured by undue pressure. The characteristic serrations on the margins of the body, due to plications of the skin, were not clearly seen. The main excretory channels are two ducts which curve round from the anterior part of the body and meet behind the ventral sucker, then pass down the mid line of the body to the termination of the appendix as a single channel. The ovary is situated about half-way between the extremities, ventrally and a little to one side, and is nearly spherical in shape. Immediately posterior to it are the vitellaria. There are two principal lobulated masses. In the specimen figured there are three lobes on one side and four on the other. At the anterior extremities the two vitelline masses are connected together by a short bridge of tissue and from this a short duct connects with the ovary. The shape of the vitellaria is far from being constant, and little value can be placed on the extent to which each lateral mass is lobulated. In some specimens the sub-division was very much less than in the figure. Over the middle part of the vitellaria was a rounded structure which is apparently the receptaculum seminis. Neither in preparations of the entire worm nor in section, however, could the exact relations of this structure with the vitellaria and oviduct be made out. The uterus in some specimens is very voluminous. In no case did it descend into the appendix. It is aggregated on the side of the body opposite to the ovary and vitellaria. The ova are very uniform in shape, and the diameters (0025 x 0°015 mm.) agree very well with 280 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the figures given by Linton for the distomid identified by him as Molin’s J. ocreatum. The testes are small, rounded bodies situated one on each side of the ventral sucker, and fairly remote from the ovary. The vasa efferentia curve round to one side of the ventral sucker, and enter the bursa of the cirrus, which lies entirely in front of the sucker, but almost in contact with the latter. The uterus opens externally very near to the male genital aperture, and apparently into a common genital cloaca. Round the extremity of the bursa and the cirrus is a prostate gland, which, however, is not a very prominent structure. The armature of the cirrus itself could not satisfactorily be made out. The above characters are mostly those of Dzastomum ocreatum, Molin, and I think these specimens may safely be referred to this species. Distomum appendiculatum, Rudolphi. From stomach of whiting (Gadus merlangus), Shoals, March, 1906. One specimen of an appendiculate distome was found in the stomach of a whiting, along with some other specimens of a distomid not yet identified. The species is probably D. appendiculatum, but the diagnostic characters of the distomids with a retractile appendix are rather confused, and it may be worth while to give a description of the present form. The measurements are ; — Length: 5 mm. Width: 1 mm. Diameter of oral sucker: 0°17 mm. Diameter of ventral sucker: 0°4 mm. Ova: 0°02 x 0°01 mm. Fig. 14 represents the animal with the appendix SEA-FISHERIES LABORATORY. cirrus . “\ PROSTAT E | oR as oN Zsa CIRRHUS POUCH St 7 INTESTINE a NGS iy nr] Cems A * . st 3 on etal eee fips . Ca eo. OYE A AGG e . races +A PPENDIX Fie, 14. Distomwn appendiculatum. x 34 dia. 281 282 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. fully expanded. The skin is almost everywhere smooth, and only in one place shows the characteristic plications. The ventral sucker is rather more than twice the diameter of the oral one, and is situated well forward. There is a short pharynx followed by a very short oesophagus. The forks of the intestine are straight and cylindrical, and extend well down into the appendix. The ovary is situated about halfway between the extremities and is oval in shape. Immediately behind it are the vitellaria, which are two in number, small and nearly globular in shape, and in close contact with the ovary. The testes lie midway between ovary and ventral sucker. ‘They are almost globular in shape and he obliquely across the body. Almost in contact with the anterior margin of the testis are the seminal vesicle and cirrus pouch. The cirrus itself is long, and is surrounded for the greater part of its length with a compact prostate gland. It opens on the posterior margin of the oral sucker. Apparently the female genital aperture is very near to the male opening, but it was not visible in the preparation. The uterus is long and greatly convoluted in the region of the ovary and vitellaria. Like the intestine, it extends well down into the appendix. The worm when alive was translucent, but possessed no distinct colour. Distomum vitellosum, Linton.* From Flounders (Pleuronectes flesus), Piel tanks. In June, 1906, Mr. A. Scott dissected several mature flounders which had been kept in the tanks at Piel Hatchery during the whole of the previous winter, and found a great number of mature distomids in the *Tinton: Bull. U. 8. Fish. Comm., Vol, 10., 1899, p. 290, pl. 37, fig. 38 SEA-FISHERIES LABORATORY. 283 intestines of several specimens. The characters of these worms agree closely with those of D. vitellosum, a species AMY 4 ~Pharynx ul, I, S orm Ventral Sucker t-Uterus \ is 2 a Oe Bs ede e : i. Ae, ey) #3 S Fig. 15. Distomwm vitellosum. ~« 70 dia. deseribed by Linton from the American hake (Merluccius 284 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. belinearts), and I think it probable that the distome described here is the above species. Measurements made from a specimen killed in fresh water and preserved in formalin are : — Length: 2 to 2°5 mm. Breadth: 0°25 to 0°5 mm. Diameter of oral sucker: 0:23 mm. Diameter of ventral sucker: 0°42 mm. Diameters of ova: 0:08 x 0:04 mm. Fig. 15 represents one of these worms seen rather from the side, but slightly twisted. The skin is smooth and without armature; the body sub-cylindrical, and in death with a very noticeable bend towards the anterior extremity. The ventral sucker is very prominent, and is situated on a kind of protuberance. It is nearly twice the diameter of the oral sucker. The pharynx is large, and there is a short oesophagus—the intestinal forks run straight back to near the posterior extremity. The ovary is situated about halfway between the extremities, is globular in shape and rather small. Immediately in front of it is the uterus, which in most specimens formed a compact mass consisting of, apparently, few convolutions and containing a comparatively small number of eggs. The vitellaria are very conspicuous structures, and in many specimens filled the body, almost preventing a proper view of the other genital organs. There are usually four bands of rounded, irregularly-shaped gland; in the figure these bands are seen from the edges, but when the worm is rotated through 90° they appear to be much more voluminous, the bands then being seen from the flat sides. In many specimens the vitelline ducts are very conspicuous, they run through the middle of the band-like masses of vitellaria, and join to form a trans- verse duct which runs across the body. The ovary is SEA-FISHERIES LABORATORY. 285 situated on the course of this transverse duct, and near to it is a small rounded body, which is probably the recepta- culum seminis. ‘The ovary itself is a globular structure. The testes are two in number, and are situated at about the posterior third of the body. The cirrus pouch and seminal vesicle lie behind the ventral sucker, and the cirrus runs forward to open near the posterior margin of the pharynx, about halfway between the ventral and the oral suckers. The female genital aperture 1s situated close to that of the male organs. Distomum mollissimum, Levinsen.* From intestine of Belone vulgaris, Foulney Island, 1906. 3 AC SEMINAL VESICLE A\) SS ) VITELLARIA {/ INTESTINE Fig. 16. Distomumn mollisimum. x 50 dia. * Oversigt d. k. Danske vidensk. Selskab Forh. No. 1, Tab. 1, 4. Kjobenhavn, 1881. 286 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Several small distomids were sent me by Mr. A Scott, who found them when dissecting a garfish—they certainly belong to the above species. The worm is easily recognised by the star-shaped vitelline glands. It is about 1°5 mm. in length, almost colourless and extremely fragile. Even the pressure of the cover glass is sometimes enough to rupture the preserved specimen. The figure (fig. 16) is constructed from a specimen preserved in formalin. Levinsen found his specimens in the intestine of Cottus scorpio. Hitherto all Cofti dissected from the Irish Sea have failed to provide this distome. Distomum, sp. From Labrus mixtus, Morecambe Bay, 1906. Three small distomids from the intestine of a wrasse do not appear to answer to any published descriptions I have seen. The specimens were, however, only seen after preservation in formalin, and it frequently happens that the details of structure necessary for certain diagnosis can only be made out in living distomids. Fig. 17 represents all that can be seen by staining the specimens to which I refer. The measurements of the worm are :— Length: 1°2 mm. Breadth: 0°56 mm. Diameter of oral sucker: 0°11 mm. Diameter of ventral sucker: 0°24 mm. Diameters of ova: 70u x 50 mu. The ventral sucker is thus about twice the diameter of the oral one. No details of the oesophagus or intestine could be made out. The vitellaria are represented by a comparatively small number of rather large, irregularly- shaped glands distributed throughout the body. No trace of ovary could be made out with certainty, so it is not represented in the figure. The testes are two large oval SEA-FISHERIES LABORATORY. 287 bodies, placed well back near the posterior extremity. Neither the ducts of these bodies nor those of the vitellaria were seen. ‘The cirrus is long, and apparently unarmed. The cirrus pouch and seminal vesicle appear to lie entirely in front of the ventral sucker, but it was difficult to be sure of this. A characteristic feature of the Mics... Distomum, sp. < TO’ dia. anatomy of this distomid is the small number of ova. In the three specimens, 12, 183 and about 24 were the numbers of eggs counted. These are comparatively large, are thin shelled and possess no appendages. In the characters of the vitellaria, the position of the testes and cirrhus and the large size and limited 988 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. number of the ova, the specimens agree with Dzstomum oculatum of Levinsen.* But the so-called eye spots of the latter species are not represented in my specimens, and the size of the ventral sucker and the presence of a distinct armature in Levinsen’s species render it unlikely that the specimens here described are PD. vculatum. Several specimens from Bazrdiella chrysura described by Lintont shew a greater resemblance, but these distomids, too, do not appear to have been identified with any known species. Derogenes varicus, (O. F. Miller). From pyloric part of stomach of Whiting (Gadus merlangus) “shoals,” off Cumberland coast, April, 1906. About half-a-dozen small trematodes were obtained from the above host. The worms were dull red in colour when alive. The figure (fig. 18) is constructed from observations made on the living worm. The principal dimensions are :— Total length: 2 to 2°5 mm.; Greatest breadth: 0°56 mm.; Diameter of oral sucker: ‘0°2 to 0°27 mm.; Diameter of ventral sucker: 0:4 to 0°43 mm. ; Diameters of ova: 0:°055 x 0:03 mm. The body is cylindrical, or very slightly flattened. The greatest breadth is in the region of the ventral sucker, where it is about one-fourth of the total length. From this region the body tapers in both directions and the posterior end is usually slightly more pointed than anteriorly. The skin is quite smooth and possesses no spines. The ventral sucker is rather variable in diameter, * Loc. cit. + Bull. Bureau of Fisheries, Washington, vol. 24, 1904, pl. 23, figs. 168, 169. SEA-FISHERIES LABORATORY. MD ----Oral sucker a = == 7 Ini@inwinss ‘ : ~Lxcretary vessel =—-- Genital aperfure YO Me Drs vii LOOKS Gj +Excretory vessel ae =Testes Fig. 18. Derogenes varicus. x 75 dia. 289 290 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. but is generally very nearly twice the size of the oral sucker. It is situated rather behind the middle of the body, and in the dead worm, usually on an elevated part of the latter. The openings of both suckers are very nearly circular in outline. The pharynx is small and oval in shape. ‘There is no distinct oesophagus and no real undivided section of the intestine. From the pharynx the intestinal rami pass transversely to the margins of the body, and then run back as wide voluminous vessels to near the posterior extremity. In the worms, after killing in fresh water, and subsequent preservation in formalin, the walls of the intestine, when seen in optical section, have crenulated outlines. In the living worms the excretory system is very obvious, but disappears entirely after preservation, and is only indistinctly seen on staining with carmine. The main vessel runs transversely across the body just behind the pharynx, then backwards as two very prominent, rather wide vessels forming a loop. These unite at about the mid transverse line of the ventral sucker, and then pass back in the median line of the body to the posterior extremity. The excretory pore is situated terminally. Often at the summit of a small papilla. The vitellaria lie far back, about halfway between the posterior margin of the ventral sucker and the posterior extremity of the body. They are rather large bodies, quite regular in outline, spherical, or slightly flattened dorso-ventrally, sometimes oval and elongated in the longitudinal axis of the body. | They are made up of a great number of small glandules, but the whole structure is enclosed in a distinct capsule, a short trans- verse duct unites them and from this the vitelline duct passes forwards to the ovary. The latter is a rounded SEA-FISHERIES LABORATORY. 291 structure lying between, and anterior to the vitellaria, and smaller than either of the latter glands. In none of the specimens could I make out with certainty the position and relations of a receptaculum seminis. The testes are two in number. ‘They are rather small, and not at all conspicuous in either living or preserved specimens. The vasa deferentia cannot easily be traced; probably they are separate and unite quite close to the seminal vesicle, or possibly enter the latter independently. The cirrus and its accessory structures lie all in front of the ventral sucker. The seminal vesicle is small and oval in shape. From it the ductus ejaculatorius passes straight forwards in the median line as an apparently strongly muscular organ, terminating in a prominent genital papilla which is situated imme- diately behind the forking of the intestine. Throughout all its length, between the seminal vesicle and the genital papilla, the ductus ejaculatorius is surrounded by a very voluminous prostate gland. In none of my specimens could the exact configura- tions of the convolutions of the uterus be made out with certainty. It is voluminous in most specimens and is erowded with ova. ‘These latter are thick-shelled and slightly yellow or red in colour. The vagina and cirrus both open into a common genital cloaca, situated at the summit of the genital papilla. The opening of this genital cloaca is in all my specimens A-shaped, or erescentic, the apex of the V, or the convexity of the erescent being directed forwards. Most of these characters would apply equally well to Derogenes minor, Looss,* or to D. varicus (O. F. Miller).t It is indeed rather difficult to make out absolutely diagnostic differences between these two species. D. minor was described by Looss from a 292 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Labroid fish (Labrus merula) taken in the Bay of Trieste, and PD. varicus has various hosts, the latest description being that of Odhner, who found the Trematode in a dab (Pleuronectes limanda) from the West Coast of Sweden. Odhner’s specimens resemble those described here in that the vitellaria are rounded and regular in outline instead of being slightly mulberry-shaped as in Looss’s species. This is the only significant difference apparent between the two species. III.— PROTOZOA. Ichthyophthirius multifiliis, Fouquet. Trichodina, sp. In June, 1906, Inspector Halsall of the Southport Sanitary Department sent some roach which had been living in Hesketh Lake, Southport. Some little time previously an epidemic had broken out among the fishes in this pond. Only the roach were affected, and pike, perch and eels living in the same water showed no signs of disease. The epidemic produced considerable mortality among the roach for about a month, but by the end of July it had run its course, and there were then thousands of young fishes in the lake, all of which appeared to be quite healthy. The fish, when received at the laboratory showed no apparent outward signs of illness. The skin was bright and clean and without traces of fungus. Dissection showed no internal lesions, and smears made from the blood and various organs * Looss: b. Hinige Distomen der Labriden des Triesten Hafens, Centralbl. f. Bakteriologie, Bd. 29, Abth. 1, p. 437, 1901. + Odhner: Die Trematoden des Arktischen Gebietes ; Inaugural Dissertation Univ. Upsala; Jena, 1905. SEA-FISHERIES LABORATORY. 293 shewed that parasites such as myxosporidia were absent. The gills were then examined, and these were found to be pale and not in a very healthy condition; also small, rounded white specks could just be seen with the naked eye, and when these were examined in detail they were seen to be ciliated infusorians. Fig. 4, pl. VIII, represents one of these organisms. ‘They varied greatly in size, the largest being about 0°75 mm. in length and 0°47 in breadth, and the smallest about 0°38 x 0:28 mm. Usually they were oval in shape, but some were quite round. Their numbers were not considerable; in a small piece of gill, from one of the smaller fishes, which was stained and mounted whole there were 17 parasites. There were 30 double filaments in this piece of gill. In some other pieces of gill roughly examined the parasites appeared, however, to be more abundant than is stated above. They lie in the gill between the filaments and compressed by the latter. They were also found on the internal walls of the operculum and branchial cavity. The parasite 1s completely covered by fine cilia. The nucleus is situated towards one end, or near the middle of the body, and is large and horse-shoe shaped. It is very coarsely granular. ‘The mouth is situated at the opposite end and is small and very definite in outline. A fain, longitudinal striation may be observed in the body. Round the margin, or rather underneath the cilia, is an evident cortical layer. Small vacuoles are very numerous in some specimens. | All these characters are those of Lehthyophthirius multifilis, Fouquet, and I have no hesitation in thus identifying the creature. It is a skin parasite, which has been described as infesting 28 or 30 species of fresh-water fishes in the rivers and lakes of Germany, France, Holland and the United States of North 294 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. America.* So far as I know, it has not previously been observed in British waters. The parasite is always described as inhabiting the skin of the infested fish, where it excavates little cavities or galleries or forms pustules. These cavities or pustules may contain one or a number of individual parasites. A characteristic spotted appearance is thus conferred on the skin of the fish. Ichthyophthirius reproduces either by fission (Stiles), or by the method of encystment. Eventually the parasite leaves the host, and after swimming about in the water for some time surrounds itself by a cyst wall, when it falls to the bottom. The young ciliated individuals leaving the cyst then pass through a free-swimming stage and reinfect fresh hosts. It is by attacking these free- swimming forms that the epidemic in a tank or small pond can most easily be fought. It appears to be impossible to destroy the parasites while living in the skin of the hosts, but if the fishes be taken from the aquarium and common salt added to the latter with a copious supply of fresh water the free-swimming individuals are easily killed. This treatment, practicable though it may be on a small scale, is, however, difficult in the case of a very large pond or “ lake.” It is difficult to say what the specific pathogenic action of the parasite may be. In the roach from Hesketh Lake there was no general infection of the skin—indeed I could not detect the parasite there in any of the specimens examined. Even in the gills the numbers were few, and it seemed difficult to believe that the mechanical destruction of the tissues of the filaments was enough to account for the death of the fish. It was, however, * There is an account of the parasite, with a summary of the literature by C. W. Stiles in Bull. U.S. Fish. Comm., vol. 13, 1893, pp. 173-190. See also Hofer. Handbuch der Fischkrankheiten, p. 122; Munchen, 1904. SEA-FISHERIES LABORATORY. 295 impossible to avoid associating the presence of the infusorian with the death of the fish, as no other cause was apparent which would account for the large mortality experienced. It is just possible that the infusorian kills the fish by forming a toxine which is absorbed through the delicate epithelium of the gills, or at the abraded surface of parts of the latter structures. Associated with the Jchthyophthirw im some of the fishes were infusorians beionging apparently to the genus Trichodina. This is the well-known ciliate found on the common Hydra. The number of specimens found were, however, few, and in such bad condition that the certain determination of the species was not possible. Lymphocystis johnstonei, Woodcock. A small sole was sent to the Laboratory in April last by Dr. Masterman, H.M. Inspector at the Board of Agriculture and Fisheries. The fish was captured off the Hast coast of England by a steam trawler, and sent to the officials of the Board in a sample box of various fishes. ‘The fish is an immature female about 74 inches in total length, and was apparently healthy and in good condition. But the greater part of the surface of the skin was covered over by very small, white, and spherical opaque bodies which were evidently parasites of some kind. They were densely scattered over the ocular side of the fish particularly on the dorsal and ventral regions of the body. On either side of the lateral line the skin was very nearly free from them, but, towards the dorsal and anal fins they became more densely aggregated together. On the fins they were most abundant, par- ticularly on the dorsal fin near the head and on the tip of the pectoral fin. Here they formed dense clusters seated on most of the fin-rays. The skin of the head was 296 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. densely covered with these structures; the tail also con- tained a few; the blind side of the fish also showed a certain number, but far less than on the ocular surface— probably on account of the attrition caused by the fish creeping over the surface of the sand. The little bodies in question were quite colourless, but very opaque, and easily discernible by the naked eye. They were nearly spherical in shape; flattened perhaps in one direction, and where they were closely packed together—as in the clusters on the fins—their shapes were polygonal. Their average diameter was about 0°32 mm. —— a ~ 7 at. > eee VA ey > ——— Poa Oy far a 7 - Soe a eiarpts { —— Ix aoe >>>: >> Dy % ™~ Y (ea fj Fig. 19. Skin of Sole infested with Lymphocystis johnstonet. x 60 dia. The fish had been preserved in formalin and the skin and the structures on and in connection with it were well preserved, but the body cavity had not been opened and the viscera were not in good condition for close examina- tion. But, apparently, the peritoneum and mesenteries SEA-FISHERIES LABORATORY. 297 were quite free from the parasites occurring on the skin. The gills were also free and apparently quite healthy. Fig. 19 represents a general view of a part of the skin which has been stained with carmine and cleared in clove oil. The parasitic structures are mostly covered by the scales. Hach is covered over by a thin fold of epidermis. Usually they are situated beneath the posterior margin of the scales under the fold of epidermis which is reflected over the latter. Sometimes they are apparently quite free from the surface of the skin and can easily be detached by the point of a scalpel, but in such cases they are attached by a delicate pedicel of epidermic tissue. In sections of the skin taken in a transverse plane they can be seen lying beneath the tips of the spines of the scales, which are then cut transversely. In section each of the parasitic bodies is almost certainly a unicellular structure. It is surrounded by a fairly thick, apparently structureless capsule, which stains with difficulty and is, therefore, more easily seen in the unstained preparations. Within is the cell body, containing near the centre an irregularly-shaped included portion surrounded by a differentiated portion of the matrix, which may represent a nuclear membrane. Within this is what may be called a nucleus. There is a matrix of finely granular substance in which are usually two or more rounded karyosomes. The cell substance outside the nucleus stains rather more darkly than that within because of the presence of numerous granules. It shows no clearly marked cortical zone, but round the periphery are a number of reticular structures, very irregular in shape and size, and usually surrounding a portion of cell substance which stains more hghtly than that in which the reticula are imbedded. Hach of these reticula appears to consist of innumerable 298 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. closely apposed granules, which take chromatic stains very easily. Close underneath the capsule, again, are a number of smaller, more closely aggregated collections of similar granules, usually spherical, or nearly so, in shape, and staining less deeply than the reticula just described. Most of the structures above described are to be seen in the remarkable sporozoan, Lymphocystis johnstonet, described by Woodcock,* and it is difficult not to identify the two parasitic structures as the same organism. ‘The mode of occurrence of the structures—on the skin and fins—is the same, and despite the difference in size I regard it as probable that in the case just described we have to deal with an invasion of Lymphocystis individuals, and that the nature of the host and, particularly perhaps, the nature of the skin of the sole—where we find strongly ctenoid scales, instead of the comparatively soft cycloid structures found in the flounder—is the reason of the difference in size. The difference in diameter, 0°32 mm. and 1 to 1:5 mm. in the sole and flounder respectively, may easily be explained by such considerations, and cne may, indeed, find many examples of analogous differences in size in identical parasitic species living on somewhat different hosts. IV.—_DERMAL CATARRH IN SALMON AND DAB. Two cases of pathological changes in the skin of fishes have been observed which do not appear to be referable to parasitic invasions of any kind. In September, 1904, Mr. R. Okell sent me some salmon parr caught in a stream near Douglas which appeared to be suffering from some obscure skin disease, obviously not due to Saprolegnia. Fish thus infected were quite *In An. Rept. Lancashire Sea Fish. Laby. for 1903, pp. 63-72. plait: SEA-FISHERIES LABORATORY. 299 abundant at this time, but about the middle of October the epidemic had greatly subsided, though even then about 10 per cent. of the salmon parr observed seem to be infected. The extent of skin affected in the case of specimens caught at this time also appeared to be less than formerly was the case. All this time salmon parr alone were infected. Brook trout do not appear to have suffered. Fig.5 (pl. VIII) represents the tail portion of one of these fish with a characteristic skin lesion. In all cases the naked eye appearance was pretty much the same as that figured, though not always so prominent. In the less strongly infected fishes the skin.appears to be covered in places with a thin, whitish scum, like felted or com- pressed cotton wool. This can easily be rubbed away and then the skin underneath appears to be quite normal, the scales retaining their usual appearance. Here and there this growth is, however, much more prominent. . For instance, in the case figured there was a raised whitish tumour on each side of the body just above the anal fin. ‘This growth was raised about 2 mm. above the surface of the skin. It had usually a slightly crenulated margin and had surface markings indicating roughly the position of the scales underneath. In the case of some of these larger growths, however, the skin underneath the adventitious tissue was disorganised and the scales came away easily. Microscopic examination showed no traces of a mycelium so the presence of a fungus was out of the question. Neither were there any traces of Myxosporidia. These were specially looked for as the naked eye appearance of some of the fish was not unlike the con- dition of “ Beulenkrankheit ’’ (Myxoboliasis). Smears were made from the blood and from all the visceral organs, 300 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. and portions of muscle tissue were examined, but no trace of myxosporidia could be detected. The gills, too, were quite normal. The skin growth was examined further for the presence of Infusoria, such as Costia. Costia necatrix produces appearances on the skin of various fishes not unlike that observed in this case. In fact, it was possible to eliminate the possibility that sporozoan or infusorian parasites were responsible for the condition. The possibility that bacteria were concerned was also considered, but a search for these was unsuc- cessful, and I had no opportunity of examining fresh material. Sections of the skin, including portions of the growth were then made and stained with methyl-blue-eosin, and Heidenhain’s iron haematoxylin. Part of such a section is represented in fig. 1, pl. VIII. It will be seen that the skin is very much altered. The scales are in some cases quite displaced, and may even be seen buried up in the tissue of the tumour. The dermis is always quite unaffected; whatever the disease is it affects only the epidermis. This latter layer is quite changed. In a normal fish it consists of roughly poly- hedral cells lying close together, and contains large mucus cells included among the others. At the base is a very regular layer of cubical cells, and at the free surface of the skin the epidermal cells become flat and horny. The tissue of the tumour replaces the epidermis, which, as a normal structure, has entirely disappeared. Instead of it we see a densely compacted mass of smaller cells. These are arranged in aggregates somewhat resembling tubercles. In the axis of each tubercle is a core of fibrous tissue, with a structure very difficult to determine; and here and there cavities containing groups of small bodies, not unlike, in size and shape, masses of SEA-FISHERIES LABORATORY. 301 myxosporidian spores. A small portion of the tumour as seen with a high power immersion lens is depicted in fig. 2, pl. VIII. Part of the core of one of the tubercles is shown with a number of the small oval bodies referred to. These have an average length of about 5u. They stain densely with eosin or iron haematoxylin, and show no obvious structure. They are not at all numerous. The rest of the tissue consists of cells of various sizes, with apparently some structureless material serving as a matrix. There are two kinds of these cells. One kind stain densely, are rather smaller than the others, and show a definite nucleus ‘The other kind appear also to be nucleated, though it is difficult to be certain, and are larger. Indeed one can easily say too much regarding the cytology of this tissue, for the preservative was only formalin and I had no opportunity of fixing the thing properly. I think the only probable explanation of this con- dition is that it represents a catarrh of the skin, such a condition as is described by Hofer* as “ Erkaltungs- krankheiten.” I have not seen any such condition as is represented by Hofer’s plates VIII and IX, but the general “ turbidity ’ of the skin, the delicate waxy bloom which he speaks of, is well shown in some of these specimens. It appears to be a paradox, Hofer says, to speak of a fish as catching cold or catarrh; still that such an ailment should be experienced by a fish is not so sur- prising as it at first appears to be. In a cold blooded animal the heat regulating mechanism, which is so characteristic and important a feature in the physiological economy of a warm blooded creature, is conspicuously absent. The temperature of a fish is always that of the medium in which it lives, or only a very little higher. * Handbuch der Fischkrankheiten, Munchen, 1904, p, 87. 302 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Such sudden changes of temperature as a warm blooded animal must accustom itself to are as a rule not experienced by fishes, for changes in the temperature of even a small mass of water such as a pond take place much less rapidly than corresponding changes in the atmosphere. Nevertheless, there are circumstances in which the water temperature may change fairly rapidly —such as, for instance, would be produced by the quick migration of a fish from one part of a small stream into another, or into a pond; or, perhaps, by a sudden freshet in a small stream produced by cold rain or melting snow. Still more would such change be experienced by fishes living in captivity as for instance in fish-breeding estab- lishments; and it is chiefly in relation to fishes living in these conditions that catarrh of the skin has been observed and studied. These Manx salmon parr were then probably suffer- ing from some kind of dermal ecatarrh. Indeed I can suggest no other explanation of the lesions observed. The other apparent cases of dermal catarrh observed were in several dabs (Pleuronectes lomanda) which have been taken during the last year or two. One fish brought to the Piel fishermen’s classes in April, 1906, by Capt. Wignall showed the condition very well. The fish was a mature male with ripe testes and apparently in normal condition. But on either side near the tail was a soft, white, slightly translucent tumour not unlike those described from the Manx salmon parr. The tumour had a papillated surface, was about 1 cm. in diameter, and about 2mm. in height. In the fresh condition there was an irregular radiate arrangement of blood capillaries infiltrating its mass. Smears from a part of this growth were made and stained by Romanowsky’s method, and also by Heidenhain’s iron haematoxylin. The blood of Prate VIII. Dermis x pr RIS csr ae £3 SEO Bs at CLAMS DOT” 8 8 > o on EO, Soe poe. igetioneres Rost inales Chromatophore FIG.I. Layer. E pains RD ap Se tee ir 1-%.Tumour on skin of Salmon Parr. A lchthyophihirius multifillis. fouquet. ©.Tail of Salmon Parr with tumour. U. JSohrsione, de/. SB. sith. SEA-FISHERIES LABORATORY. 8038 the fish was also examined, but was quite normal. Indeed, with the exception of the tumour described no other evidence of disease could be discovered. The tissue of the tumour showed a general resem- blance to that described in the case of the young salmon. But there was a much larger quantity of broken down material, of a finely granular nature, lying between the cells. The latter are apparently epidermal cells altered considerably, staining only very lightly with Romanowsky, but deeply with iron-alum haematoxylin. Among these cells are nests of bacteria staining well with Romanowsky. Several of these are represented in fig. 3, pl. VIII, andit will be seen that they are of very various forms. The long delicate bacillus occurs rather rarely ; it is about 104 in length. Other forms are short curved rods and thick, dumpy bacill, most of which stain as if spore formation were in progress, but are probably only the involution forms of a bacillus akin to the long slender forms. These bacilli are not very numerous, though a fair number could be seen in every field. An attempt was made from the fresh tissue to set up a cultivation on nutrient gelatine at ordinary room temperature, but no results were obtained. Probably they represent only a secondary infection on a partially broken down prolifera- tion of the epidermis. The whole appearance of the latter is so similar to that in the Manx salmon parr that I am inclined to regard this also as a case of dermal catarrh. A mechanical injury is out of the question as the skin underneath was almost normal and no traces of infection by a sporozoan or other parasite could be detected. 304 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. ON A MYXOSPORIDIAN INFECTION OF GADUS ESMARKII. By Jas. JOHNSTONE. WITH A NOTE ON THE IDENTIFICATION OF THE PARASITE. By H. M. Wooncocx, D.Sc., Lister Institute of Preventive Medicine. I. In 1889 Giinther* first recorded the presence of the Norway Pout, Gadus esmarki, in British waters. This fish, previously known only in Scandinavian waters, was noted by Gunther in the Firth of Clyde, and in some of the Western Scottish Lochs, at depths varying from 26 to 80 fathoms. Speaking of the characters of the fish Giinther says, “ Many of them suffered from a singular affection of the eye, namely the whole eyeball, and also a greater or lesser part of the iris, being covered with cysts containing a cheesy matter.” | Again in 1900 Fultont makes a similar observation. Gadus esmarkit, belonging to the so-called Scottish and Scandinavian types, was found by him in the Northern part of the North Sea, where it appears to be fairly abundant, and in the Firth of Clyde. Fulton says that “a very large proportion of those taken in the Firth of Clyde had one or both eyeballs affected in the manner described by the author named [Giinther], (the cysts, however, containing fine granules) but no specimen from the North Sea was observed to be so affected.” In March of 1906, a Norway Pout: was caught in a * Proc. Roy. Soc. Edinburgh, vol. 15, 1889, p. 212. Rept. Scottish Fishery Board, 19, pt, 3, 1900, pp. 282-4. SEA-FISHERIES LABORATORY. 8305 shrimp-trawl worked in shallow water near Morecambe, and sent to me. ‘This specimen had both eyes affected _ in the manner described by Giinther and Fulton. These are the only instances of this affection of the eye which, so far as I am aware, have been observed. Although the fish has been known for a long time on the coasts of Scandinavia, and has since been found on most of the coasts of the British Isles, the eye parasites have only been found on the West Coast of Britain. Probably the specimen found at Morecambe is one of many which have migrated into the Irish sea through the North Channel. Fig. 1, pl. IX represents the head of the specimen (twice natural size). The eye is perhaps larger than in normal specimens. Round the peripheral part of the cornea, and covered loosely by conjunctiva are a number of milk-white rounded or oval bodies, from about 1 to 3 mm. in diameter. Several of these have fused to form elongated masses, which take the curvature of the periphery of the eye. Growing out from the lower margins of this ring is a botryoidal mass of similar material which encroaches on the pupil. When one of the eyes was removed it was seen that these adventitious structures had invaded the lateral and posterior parts of the bulbus oculi. These structures remind one of pustules. When pricked (in the fresh condition) a thick, white, pus-like substance could be squeezed out. But when a trace of this was examined under even a low power of the microscope it was immediately seen that the structure was a Myxosporidian cyst. The “fine granules” filling up the interior were spores containing two polar capsules, and in some cases, two polar filaments were seen under a high power. Vv 306 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Fig. 8, pl. IX represents a nearly meridional section of the wall of the bulbus oculi. Apart from the shape of the bulbus, and the presence of the processus falci- formis and campanula, the fish eye does not differ greatly from that of higher Vertebrates. In the wall, however, we find a choroid layer possessing features solely piscine, and also the peculiar argenteal layer. The sclerotic consists of two layers, (1) a layer of cartilage, ceasing some distance behind the iris: on the internal surface of this is the argentea; and (2) a fibrous layer which lies external to the cartilaginous layer. This feature is, of course, paralleled among other Vertebrata. The intrusive cysts le within the thickness of the cartilaginous layer of the sclerotic. This latter is, of course, quite thin in the normal eye, whereas in the diseased specimen the cysts are sometimes over 2 mm. in diameter. The multiplication of the Myxosporidian within the cartilaginous sclerotic has, therefore, distended the latter layer. In section a layer of cartilage, some- times, hewever, very thin, can be traced all round the cyst. In other parts of the section the cartilage thins out and almost disappears, being either mechanically stretched or, perhaps, reduced by the reaction of the Myxosporidian tissues. The other parts of the eye were apparently quite normal. The function of the organ had not apparently been affected; though it is probable that a kind of cataract might easily be induced by the invasion of the cornea by the cyst masses. This process has indeed begun in the eye figured. J. J. SEA-FISHERIES LABORATORY. 307 JO. Mr. Johnstone kindly sent me a couple of smears made from the contents of one of the cysts above described, expressing his opinion that a Myxosporidian parasite was concerned, and asking me to identify it. On examining the smears, I saw that they consisted entirely of spores, evidently belonging to a Phaenocystan parasite, for two brightly refringent polar capsules were visible in each. One of the slides was stained with Heidenhain’s iron-haematoxylin, the other with thionin. For some reason or other the first method did not prove a success, the stain persisting in the spore-wall in a rather blotchy manner, and obscuring the contents; while the polar capsules did not retain it at all. By the second method the spore-wall itself remained unstained, the polar capsules were deeply stained, and the various nuclei, though not retaining the stain as much as was desirable, eould often be made out with a little trouble. Two spores are seen in fig. 2. In shape they are slightly ovoid, their dimensions averaging 10 » in length by 8 w in breadth. The two polar capsules (p.c.) are situated near one end of the longer axis; the length of each varies from 3} to 34 uw. Unfortunately, I could not find a single spore in which either or both of the polar capsules had the filament evaginated. This was a little surprising, as in a similarly prepared slide of another parasite (Sphaerospora platessae) which I have previously characterised,* the stimulus of spreading the smear had caused many of the capsules to evert their filament. So that I have not been able, so far, to ascertain the length of the filament in the spores under discussion. Occupying a considerable portion. of the sporoplasm is a large, well- Woodcock, Proc. L’pool Biol. Soc., Vol. XVIII., p. 140 (1904). 308 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. defined vacuole (7.v.) which is invariably present. This ts the iodinophilous vacuole, which is characteristic of ali members of the Phaenocystes belonging to the family Myxobolidae. ‘The nucleus in connection with each polar capsule—the nucleus, z.e., of the so-called “ capsular cell,” or portion of the pansporoblast from which each capsule is formed—is shewn at (n.p.c.). The two germ-nuclei of the undivided sporoplasm are visible at (V). It may be added that, in one or two instances, I could make out a slightly deeper-staining line or thickening just internal to the spore-wall on either side. These probably represented the nuclear remains of those other portions or organellae of the pansporoblast, which, as recently shewn by Léger and Hesse,* give rise to the two valves of the spore. As, however, I did not feel quite sure of them, owing to the faintness of the staining, and as neither of the spores drawn actually shewed them at all, I have not included them in the figure. With regard to the systematic position of this parasite of Gadus esmarkii, the simple shape of the spore, lacking any tail-processes, makes it apparent that it must be included in the genus A/yxobolus; and, further, the presence of two practically equal polar capsules places it in the corresponding section of this genus. The dimen- sicns of the spore do not agree at all closely with those of any Myxobolan spore, belonging to this section, which has so far been described. Moreover, up till now no Myxosporidian has been known to occur in one of the Gadidae. Hence it is most probable that this Myxobolus is a new species, for which I propose the name Jf. esmarkii. * Léger and Hesse, C. R. Ac. Sc., 19th March, 1906. ° ay -k, Ms His dial e a ae la (if. 71 oft Pigment layer of choroid MYXOBOLUS ESMARKII. 1. Head of Gadus esmarkii with infected eye. 2. Spores of M. esmarkii. 3. Seclion of optic bulb with mfecled sclerote. fics (ei SJSohnstone del kia. 2. tiM. Woodcock. def, (Ca) PLare |X B. ith, a nec eee SEA-FISHERIES LABORATORY. 309 ICHTHYOLOGICAL NOTES. JAS. JOHNSTONE. (1) An hermaphrodite hake. In June last, Mr. W. Wright, a fisherman who had attended the classes at Piel in 1905, recognised that a hake which he was gutting on board a steam trawler, fishing off the West Coast of Ireland, was possessed of hermaphrodite organs. The viscera were, therefore, preserved in some spirituous liquid and handed to Capt. Wignall, who sent the specimen to me. In the course of dissection, which is always a much more rapid process -on a steam trawler than in a laboratory, the viscera had suffered considerably, and the relations of the genital ducts, urocyst, and alimentary canal were not at all clear in the specimen when it reached me. Nevertheless, there is no doubt that the organs are those of a hermaphrodite hake. Both ovaries are present. That on one side is 5-5 x 325 cm. in diameter; that on the other side being 65 x 35 cms. in the corresponding dimensions. They are apparently normal organs, hard, and crowded with small ova, and not dissimilar in structure and stage of ripeness to the ovaries of a normal hake at the same stage of development and at the same period of the year. The ova are about 0°8 mm. in diameter. At the posterior end of each ovary is a testis. These organs have the shape and appearance characteristic of a well-developed gadoid testis. ‘They are apparently incomplete so I do not give their dimensions. Both are equally well developed, and each is larger than the ovary to which it is attached. They are convoluted in the usual manner though the convolutions are not so 310 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. numerous or complex as in a normal male fish. A thick ' sheet of peritoneum, loaded apparently with fat, connects the two testes. On cutting open the ovaries there was no perceptible lumen, except at the posterior end, where the substance of ovaries and testes became con- fluent. At this place the lumen of the ovary was continuous with that of the proximal part of the testis. Cases of hermaphroditism in most teleosts, especially in Gadoid fishes, are, of course, very rare. Nevertheless, a fair number of hermaphrodites have been described. The earlier literature is discussed, and the instances of hermaphrodite codfish cited in the well-known paper by Howes* on the “ Hermaphrodite genitalia of a codfish,” a further instance as recorded by Ramsay Smith,t and other cases are recorded by Masterman,{ who discusses the cases recorded later than those in Howes’ classical paper. The specimens figured by Howes and Masterman were apparently functional females. Whether or not ripe spermatozoa were extruded by these fishes while alive is difficult to say, but probably the male organs were functionless. In Ramsay Smith’s specimen (from a haddock) the testes and ovaries were equally well developed, but the former were relatively larger than in Howes’ specimen, where the testis formed a small rosette- shaped structure at the extremity of the ovary. In Masterman’s specimens the testes were small and there were a few ripe eggs 1n the mouth of the oviducts. These fishes were, therefore, probably functional females. In the specimen now before me we have what is probably a functional male fish. The testes are well developed and there is free communication between them and the * Journal Linnean Society, vol. 23, 1891. t Rept. Scottish Fishery Bd., vol. 9, p. 352 1891. Do. do. vol. 12, plates 3 and 4, and vol. 13, p. 297, 1893- SEA-FISHERIES LABORATORY. 311 cavities of the ovaries and oviducts. If ripe spermatozoa were extruded these must have been emitted through the (normal) female genital aperture. In the southern Irish Sea the hake appears to spawn later in the year than its allies. Holt* found ripe specimens as late as July, and concludes that, in the Irish seas, the spawning period of the hake may be prolonged from March until the end of July. Hwartt found that the spawning took place late in the year, and M’Intosh reports a ripe male in August on the Hast Coast of Scotland. Apparently, then, the fish may spawn about midsummer, and, if so, the hermaphrodite specimen here described was a functional male—that is if the fish were sexually functional at all—for the ovaries were those of a fish which certainly had not spawned during the year when it was caught, and apparently would not have done so had it remained in the sea. On the other hand the testes had all the appearance of nearly ripe functional organs. It was interesting to note that two or three small pear-shaped bodies possessing all the structure of a testis, were attached to the outside of one of the ovaries some distance from the place where the main testicular mass and that of the ovaries joined. (2) Gurnard (Trigla gurnardus) with malformed lower jaw. A small grey gurnard sent me some time ago by Captain Wignall shews an interesting malformation of the lower jaw. The head of this fish is represented in tig. 20. Seen from the side a notch appears to have been cut out from the mouth of the fish, and even without dissection the peculiar appearance is seen to be due to * Sci. Proc. Roy. Soc. Dublin, vol. 7, p. 401, 1892. + 7th An. Rept. Scottish Fishery Board, pp. 3, 196, 1889. 312 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the absence, or at least great reduction in the size, of the lower jaw. ‘The upper jaw overhangs the mouth which is reduced to a small crescentic slit on the lower side of the head; both jaws are quite immovable. Whatever food the fish obtained must have been of very small size. There were no recognisable food remains in gut or stomach. Nevertheless the fish appears to be healthy and in good condition. Fie. 20. Trigla gurnardus. Natural size. Fig. 21 represents the normal suspensorium and jaw apparatus of a grey gurnard, and it will be seen that we have here the type which, with no essential variation, is encountered among almost all teleostean fishes. In the abnormal skull now before us (fig. 22), the parts of the suspensorium and upper jaw are essentially as in the normal skeleton. The palato-pterygoid arcade consists of the same bones, and in the same relationships as in the normal skull. So also with the maxilla and pre-maxilla. The palato-pterygoid arcade is, it is true, shifted dorsally SEA-FISHERIES LABORATORY. 313 to a position much nearer to the ventral surface of the skull, and this is also the case with the bones of the upper jaw. But otherwise all are quite normal. The difference in the two skulls hes in the lower jaw. In the normal skeleton this consists of the usual parts, dentary, articulare and a very small angulare, and is rather massive. In the abnormal skull these parts are altogether different and are much dwarfed. There is no apparent angulare, but, perhaps this is ossified together with the articulare. This element «fen YSUBOPERCULUM ar ~~ BREOPERCULUM ANGULA REN “SYMPLECTIC QUADRATE Fie. 21. Skull of Trigla gurnardus. Natural size. igor at all dike the normal. bone; it is an irregularly shaped bone the long axis of which is dorso- ventral. On its posterior surface is a saddle-shaped articular surface which receives the articular knob of the quadrate. In front and a little above this is a socket- shaped articular surface into which the proximal end of the lower jaw proper fits. The latter consists of an apparently single bone, which is a flat hoop forming the lower margin of the gape. It probably is the fused and completely ossified Meckelian cartilages, whether or not 314 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. membrane bones are included in it is not certain, but it probably represents only the two Meckel’s cartilages. From these parts, and the articular elements, a strong tendinous and muscular sheet of tissue passes ventrally and is inserted into the hypohyal elements of the hyoid arch. It is the latter which form the prominent “ chin ” shewn in fig. 20. MAXILLA PALATINE “OPERCULUM y/PREQPERCULUM oe BOPERCULUM Fic. 22. Malformed skull of Trigla gurnardus. Slightly magnified. Malformations of this kind are extremely rare among teleostean fishes living in nature. Probably individuals exhibiting them are eliminated at an early stage of their life history. If, as is probably the case, the malforma- tion here described was developed during the post larval stage it is difficult to see how the fish contrived to secure enough food. But it is probable that the gape was of greater extent in this stage, and that the very contracted mouth opening was only developed after adult growth had been attained. SEA-FISHERIES LABORATORY. 315 Gadus esmarkii, Nilsson. The Norway Pout, although by no means an in- frequent fish in British waters, has not until the spring of this year been recognised on the eastern side of the Trish Sea. Probably it is not uncommon among the shoals of small whiting which at times frequent the shrimping grounds. The specimen referred to here was caught by a shrimper near Morecambe, in March, 1906, and was sent to me by Mr. Ed. Gardner. It was a gravid female, containing ripe ova. Both eyes contained a myxosporidian parasite, which is described above. Notrt.—While this report was going through the press Mr. Ragdale, Chairman of the Scientific Sub-Committee, noticed in the Manchester fish market a fine specimen of Beryx splendens, Lowe, measuring twelve inches from extremity of head to root of tail. It was caught off the S.W. coast of Ireland in Lat. 49° 10’ N. Long. 11° W. ‘The specimen has been presented by Mr. W. Vernon to the Manchester Museum.—W. A. H. 316 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. THE FOOD OF FISHES. By Jas. JOHNSTONE. Observations on the food of comparatively few fishes have been made. The following lists refer to the examination of the stomachs of 114 plaice and 146 dabs. The observations were made not as part of a systematic scheme for the investigation of the food of fishes in general, but rather with the object of exhibiting the contrast between the food of plaice and dabs caught on the same fishing ground and in the same hauls of the net. I give the numbers of both kinds of fish taken in the hauls; the sizes of the fish are not given, but generally plaice of 9 to 12 inches in length, and dabs of 7 to 10 inches were examined. The contents of the stomach and intestines are given for each fish examined and the observations relating to plaice and dabs caught together are put in parallel columns. 1. Plaice and Dabs. 3rd January, 1906.—Blackpool Closed Ground. Catch: 3 plaice, 77 dabs : — 3 plaice and 6 dabs examined, but all had empty stomachs. 9th January, 1906.—Beaumaris Bay. Catch: 146 plaice, 109 dabs : — top baee- | 8 dajbis- 4—-ikmpty. 3—Hmpty. 1—Scrobicularia. 1—Mactra. 1—Solen and Scrobicularia. 1—Mactra and Crangon. 1—An amphipod. 1—Foot of Cardium. 2—Ophiurids. SEA-FISHERIES LABORATORY. 317 20th February, 1906.—“ Shoals.”” Catch: 23 plaice, 29 dabs :— (OM as ie e:. ales dia bis’. 4—_Solen. 5—Solen. 2—Solen, Polychaete. 1—Solen, Portunus. 1—Solen, Polychaete, 2—Gonoplax. Eehinid. 1—Nephrops. 1—Crab. 1—Gephyrean worm. 3—Empty. 14th June, 1906.—Tremadoc Bay. Catch: 15 plaice, 24 dabs : — Sep lad ce - 5 Glalog, 1—Solen, Mactra. 1—Solen. 1—Mactra. 1—Solen, Macira. 1—Polychaetes. 1—Portunus. 1—Portunus, Nereids. 1—Nephrops. 1—Compound ascidians. 19th June, 1906.—Aberporth Bay. Catch: plaice, dabs : — 12 dabs. 4—Ophiurids (stomachs very full). 1—Ophiurids, Pagurus, Scrobicularia. 1—Scrobicularia, Aphrodite. 1—Scrobicularia, Nucula. 1—Scrobicularia. 1—Pagurus, Scrobicularia, Natica, Aphrodite. 1—Pagurus. 1—Aphrodite, Scrobicularia. 1—Ampelisca (stomach full). 318 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 9th July, 1906—Near Nelson Buoy. Catch: 320 plaice, 126 dabs : — 2 eplaice: 1 0) dabist 1—Solen. 1—Tubicolous polychaetes. 1—Nucula. 1—Tubicolous polychaetes, 1—Tubicolous polychaetes. Nucula. 3—Tubicolous polychaetes, 1—Ophiurids. Scrobicularia. 3—Ophiurids. 1—Tubicolous polychaetes, 1—Ophiurids, Nucula. Scrobicularia, Nucula. 1—Holothurian, Pectinaria. 3—Tubicolous polychaetes, 1—Portunus. Nucula. 1—-Empty. 1—Tubicolous polychaetes, Scrobicularia, ophiurids. 1— Empty. 10th July, 1906.—Off New Quay. Catch: 8 plaice, 16 dabs :— on epila meee: 6 “da ose 3—Polychaetes. 2—U pogebia. 2—Hermit crabs. 1—Ophiurids. 1— Empty. 13th July, 1906—Llandudno Bay. Catch: 16 plaice, 84 dabs: — 2" plaice: 12 dabs. 6—Scrobicularia, Nereids. 3—WNSabella. 3—Nereids. 3—Sabella,. sprats. 2—-Nereids, Echinocyamus. 2—Sprats. 1—Solen. 1—Sprats, Crangon. (Little food in any stomach).1—Sprats, Actinia. 2—Portunus. (Stomachs full.) | SEA-FISHERIES LABORATORY. 319 19th September, 1906.—Red Wharf Bay. Catch: 5 plaice, 24 dabs :— 3 plaice. 21 dabs. 3—Scrobicularia. 3—Ophiurids. 1—Ophiurids, Solen. 1—Ophiurids, Scrobicularia. 1—Ophiurids, Hermit crab. 1—Ophiurids, Crangon. 1—Ophiurids, Ampelisca, Hermit crabs, Echinus. 2—Scrobicularia, Ampelisca. 1—Ampelisea, Ophiurids. 1—Ampelisca, Hermit crab, Ophiurids. 2—Hermit erabs. 1—Crangon. 1—Carcinus. 5—Hmpty. 20th September, 1906.—Entrance to Formby Channel. Catch: 22 plaice, 150 dabs. 8 plaice. 11 dabs. 2—Scrobicularia. 1—Tubicolous worms. 2—Scrobicularia, 2—Tubicolous worms, Polychaetes. Mactra. 2—Ophiurids, Polychaetes, 1—Tubicolous worms, Mactra. Venus. 1—Polychaetes, Mactra. 2—Tubicolous worms, nay, Portunus. (Very little food in 1-_Tubicolous worms, stomachs.) Carcinus. 1—Natica. 1—Nereids. 1—Sprat, Ophiurids. 1—Sprat, crab. (Stomachs full.) 320 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 2nd October, 1906.—Luce Bay. Catch: 88 plaice, 14 dabs. ; Zeeep ead c'e: 4 dabs. 10—Solen. 1—-Arenicola. 1—Solen, Nereids, 1—Portunus. Ampelisca. 1—Nephrops. 2—Solen, Nereids. 1—Philine, Tube worm. 1—Solen, Ampelisca. 2—Solen, Nucula, Mactra, Crab. 3—Nereids. 1—Nereids, Ampelisca 1—Arenicola. 2—Hmpty. aa 2nd October, 1906.—Luce Bay. Catch: 21 plaice, 21 dabs :— ae © Vole roe. 6 da bse 6—All Solen. 1—-Solen. ; 1—Solen, Pandalus. 1-—Solen, Ophioglypha. 1--Solen, Crab. 1—Philine. 1—Gasteropod foot. 2nd October, 1906.—Luce Bay. Catch: 184 plaice, 37 dabs :— . (amspllvaece | 14 dabs. 1—Solen. 1—Solen. 1—Solen, Nucula. 3—Ophioglypha. | 1—Solen, Nucula, Nereids. 1—Ophioglypha, Scrobicu- 1—Solen, Nucula, Nereids, laria. | Scrobicularia. 1—Ophioglypha, Scrobicu- 1—Nucula. laria, ‘Uhraciaesae 1—Nucula, Nereids. 1—Ophioglypha, Carcinus. 1—Nucula, Serobicularia. 1—Ophioglypha, Cardium — echinatum. 1—Scrobicularia, Crab. 2-—Hermit crabs. 7” 1—Portunus. 1 =Phline: 1—Nemertine. SEA-FISHERIES LABORATORY. BAIL 5th November, 1906.—Catch: 41 plaice, 82 dabs :— Le Olea iGe. . lo dabs. 3 10—Solen. 4—Solen. 2—Solen, Crab appendages. 1-—Solen, Nereids, Hermit crabs, Zoophytes. 1—Hermit crabs, Solen. - 1—Hermit crabs, 7 Amphitrite. oe -_1—Hermit crabs, Solen, Pecten. 1—Zoophytes, Solen. 1—Portunus. 1—Soft crab. 4—Kmpty. 22nd November, 1906.—Near Nelson Buoy. Catch: 10 plaice, 10 dabs :— Seeplaice. (diay bis. All empty. All empty. It is, of course, only practicable to display these observations in a roughly quantitative manner. The actual numbers of food animals present in the alimentary canal of each fish were not counted, and only approximate estimates of the abundance of each constituent of the food were made. It is, nevertheless, possible to shew roughly what is the commonest food of each fish. In the following table the numbers of black dots represent the number of fishes in which the food animals noted in the adjoining columns occurred exclusively. Hach full dot represents two fishes. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 322 ‘sqep pur soreyd Jo pooq “ez ‘DLT a ae Ee ea ee SA snureAoourgo gq": ~elOoTUeIy"** STOUR T[oOUVT pue spraniqdg'*"|®@ ee STMT x YY YY soyevyoAog snopoorqny,"*"|@ sojovyoATog’*’ spodiqdury'*"|q@ eo0e4SNID + "“1@ sojovyoAtog + re cat soqyovqoAog + ‘i “1900800000 eooeqsnig + ws “1@ SHOUSICII[OMVT’ |\SOSSSSOSOOOOOCOOCCCOCCOCSE MOIVIg vocceceece panpensnereson Kn denier eeeeee eocccerccccccee seykydooz rteseeseeeeeeeeserees QUIT TOUIONT wee eeeeeeseceseeee epodoso4se4y Foe Etre cevade ten elootuely See sarees “LIN JO[OHT erate SUETDIOSY, ER eeereecereescssere “-ueersqdexy Pp@e@e@e@eeee90 eeevee eee esecccees vee spraniqdg @@@) syouviqijemey+ “« »>@@@'':'::: eooejsnip+spraniqdg Divcrcerees sprantygdo + “ Dd eeseee eeeecee eluryoy + (a4 @ eeeceeeree e90Bqsniy + rs D eee cece eseces eecees “sre samIdg Dd 8 eeeeee syeaidg + «ec D\*“wooeqsnig + se ee ee ¥ B® @\-: soyovyoATOg snojoorqny, D eer ccccccccesceseces sojoeqoATog D @ eeeeerece eee eooeqysnin I9TIO D cor nccvseccecenecccece spodiyqdury d@ eercccccccccces ececce sdorydo yt ® @ e ® @ re) eccvccccetccnce snainsedny Aporyo ‘sqery 10q110 Di--: soqgovqoAjog ns eee eee eer ecreseeeeeeeees snunji0g |) (S) Cee eeererorecceceses eens eullIqd de Bee eq [Odi + oe D@@@ @|vo0vjsnIip+ cs eeee0e000''" sqOURIqIT[OuUe'T SAV] SEA-FISHERIES LABORATORY. 323 When arranged in this way the contrast between the food of plaice and dabs is at once evident. We see (1) that the dab is an omnivorous feeder and that it will take anything on the sea bottom from a sprat to a zoophyte; but that (2) it indicates a preference for particular food animals such as ophiurids, crabs and lamellibranchs. The latter were usually Scrobicularia alba, Mactra, Tellina, and often the feet of Cardiwm echinatum. The crabs were either Portunus depurator, which often occurred alone in the alimentary canal, Carcinus moenas, which was less common, or Hupagurus bernhardus, which was, perhaps, the commonest crab found as the food of the dab. The ophiurids were nearly always Ophiura albida. The Amphipods were always Ampelisca. Sprats were, of course, an unusual food, but on one occasion (in Llandudno Bay, on 138th July, 1906), two dabs were found which were gorged with small sprats. The tubicolous Polychaetes were either Sabella or Amphitrite. U pogebia, a Callianassid Crustacean, which so far we have only found in the stomachs of fishes, was found in two dabs taken on 10th July, 1906, off New Quay Head. At the foot of the first column in the table are given several animals which occurred exceptionally in the stomachs of dabs examined from various grounds. They were generally associated with other food animals and never occurred in abundance. ‘They indicate further the catholicity of taste of the dab. The plaice affords a decided contrast. It will be seen that by far the commonest food animals of this fish were lamellibranch mollusca. Next in importance come Polychaete worms which very seldom, apparently, afford an exclusive food for the plaice, but are nearly always associated with lamellibranchs. Both errant and tubicolous polychaetes are eaten. The former are 824 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. usually Nereids, and the latter are often Sabella and Pectinaria. Ophiurids afford a very exceptional food for the plaice. Once or twice Hehinocyamus pusilla was found, but in association with other animals, usually lamellibranchs. The commoner lamellibranchs are, of course, those eaten by the plaice. The following table represents the order of abundance in which these animals occurred in plaice stomachs : — BOleM ee ecencsese on 0000080008000 0800808008088000088 Gt Solen-+ Mactra ..|/q Solen+Nucula..|/@ Solen+ Scrobi- ) cularia | < Scrobicularia ....\@@@ » +Nucula..|¢@ INCU ay se. occ ow sec ) MACCPA A vicsas Shccee ) Fic. 24. Food of plaice. The distribution of plaice and dabs, considered as a bionomic problem is, of course, one which would require much more patient and serious investigation than we have yet been able to attempt. In the consideration of the commoner food animals eaten by each species there is, however, a probable explanation of the comparative ubiquity of the dab as compared with the plaice. The latter is much more fastidious in its tastes than the dab, and when the common bivalve molluscs, which it always prefers, are not present on a fishing ground, or are sanded up, or disappear from any other cause, the plaice deserts this ground in favour of others where these molluscs are to be found. So we find that a “strike,” or settlement - of the spat of mussels, or other lamellibranchs on any fishing ground is often followed by an extensive immigra- tion of plaice to this spot. Fishermen credit the plaice with the possession of some occult power of detecting the SEA-FISHERIES LABORATORY. 325 presence of abundant bivalve food, even at considerable distances, but the reason of these aggregations of plaice on sea bottoms where there is for a time an abundant young lamellibranch fauna is simply this, that plaice are always to some extent moving about, except perhaps during one or more of the colder winter months, and when they encounter accidentally such an abundance of their favourite food they remain in the place where this is to be found deserting it when the food becomes scarce. On the other hand, the dab, being a greedier feeder, and one accustomed to “take what it can get,” finds a more or less abundant table spread for it on almost any of the shallow-water fishing grounds off our coasts. So we find that the dab is much more widely distributed than the plaice, and that when we cannot fish the latter the dab is generally to be obtained. The sole is again more fastidious than either plaice or dab. The stomachs of these fish caught on the “ John Fell” have been examined very often, but the results are not tabulated. One finds, however, that it is com- paratively rarely that soles have any food animals in their stomachs other than Polychaete worms. In the varying abundance of the latter we have then one of the causes of the migrations of the sole. Of course, this is not the only cause, but, no doubt, it is one of the most - Important. Finally I give the records of the examination of the stomachs of several cod caught during the early part of the year. They shew little beyond what we already know, viz., that the cod feeds largely on fish and crustacea. 326 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Cop. 9th January, 1906.—Beaumaris Bay. One specimen, 33ins. long. Contents of the stomach were :— 3 dragonets ; 1 poor-cod ; 1 small pleuronectid. 3rd January, 1906.—Blackpool Closed Ground. One specimen, about d3ins. long. Stomach contents :— 33 sprats (or young herrings, species indeter- minable). 1 pleuronectid, 8ins. long; 3 pleuronectid, 3ins. long; 6 shrimps; 1 Aphrodite ; 1 piece of coal. 24th January, 1906—Beaumaris Bay. One cod, 30ins. long. Stomach contents : — 6 Carcinus. 31st January, 1906.—Red Wharf Bay. 1 cod, 30ins. long. Stomach contents :— 6 Hermit crabs. 31st January, 1906.—Near Liverpool N.W. Light Ship. Cod, 27ins. long. Stomach contents :— 1 whiting, 10ins long. Cod 22ins. long. Stomach contents :—— 7 Portunus. Codling, 9ins. long. Stomach contents :— 9 Portunus. SEA-FISHERIES LABORATORY. 327 Ist February, 1906. Near N. Constable Buoy. © Cod 32ins. long. Stomach contents :—— 2 flat fishes, 6 to 8ins. long; 1 dragonet ; 15 Portunus. 20th February, 1906.—Shoals. Cod, 33ins. long. 1 dragonet ; 15 Portunus. 20th February, 1906.—Shoals. Cod, 3dins. long. Stomach contents : — 1 poor-cod, much fish debris. Cod 28ins. long. Stomach contents :— 8 Portunus; 1 small whiting. tod 28ins. long. Stomach contents :— 7 Nephrops. 328 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. REPORT ON VARIOUS BACTERIOLOGICAL ANALYSES OF MUSSELS FROM LANCASHIRE AND WALKS. By Jas. JOHNSTONE. 1.—On THE BACTERIOLOGICAL ANALYSIS OF MUSSELS FROM St. ANNES-ON-THE-SEA. At the last meeting of the Scientific Sub-Committee in May, 1906, instructions were given to make a bacteriological examination of the mussels on the bed near St. Annes. Accordingly on June 6th, 1906, Dr. Jenkins, Mr. J. Wright and I visited the locality in question and I then collected a sample for analysis. The sewer at St. Annes is an iron pipe 24 inches in diameter which runs out over the foreshore to the low water mark of ordinary spring tides, and discharges some distance North of the town into the channel known as North Channel or Hollow. The flow of sewage through the pipe is continuous and there is delivered every 24 hours approximately 227,800 gallons (= 26 gallons per head of population). The sewage is quite untreated. The mussel bed is situated near to, and indeed round, the sewage outfall, and some little distance to the South of the latter. It is a small bed but the mussels on it are fairly abundant. The shellfish are of good quality, with fine, clean and thin shells, apparently rapidly growing fish. Those examined were apparently well- nourished and healthy molluscs. The ground was, at the time when I collected the sample, fairly hard and clean. There were quite a number of starfishes on the bed, and to the presence of these animals is to be ascribed the unusual SEA-FISHERIES LABORATORY. 329 number of empty shells present on the ground at the time. We looked for paper or other naked-eye evidence of sewage deposits on the bed but could see little traces of such matter. : This bed has long had an evil reputation and I am informed by Dr. F. Booth, Medical Officer of Health for the Urban District of St. Annes, that though he has no direct evidence of illness in St. Annes resulting from the consumption of these mussels, the Medical Officer of Blackpool has attributed several cases of enteric fever directly to the consumption of mussels from this bed. Unfortunately there is also grave reason for suspecting the cockles from the adjacent foreshore. It is apparently the case that cockles clean themselves of ingested sewage bacilli much less readily than mussels (Klein). ‘That is, these micro-organisms find a more suitable nzdus in the tissues of the cockle than in those of the mussel. I think the direction of the tidal streams favours the contamination of these mussels. Not only is there direct and continual pollution by the St. Annes sewer, but a considerable quantity of greatly diluted sewage from Lytham and even from the Ribble Estuary generally, must find its way over these grounds at the earlier period of the ebb-tide. It is true that St. Annes sewage must pass out to sea through the North channel after the higher sand banks have become bared by the ebb, but it is also probable that, with the first of the flood some at least of this sewage may find its way back through the same channel on to the mussel bed. The topography of the coast, indeed, renders it impossible that these shell- fish can escape direct contamination. The sample of mussels for examination was collected about 5 p.m. on 6th June. The mussels were collected from every part of the bed and at once placed in a recently 330 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. - sterilised, tightly closing paint tin. They were taken back to Liverpool on the same evening and the unopened tins were at once placed in a sink and packed round with fragments of ice. The lids of the tins were tightly closed to prevent ingress of the water resulting from the melting of the ice. Every precaution was thus taken to prevent multiplication of the micro-organisms con- tained in the shellfish during the interval between collection and analysis. When the tins were opened next day the valves of the mussels were still tightly closed; in the meantime not all the ice had melted. The primary inoculations were made in the forenoon of June 7th, within 20 hours after collection of the sample. ‘Ten mussels were selected at random from the entire sample. The outside of the shell of each was rapidly washed with tap water (Liverpool water is free from sewage bacteria). The mussel was then opened with a sterile instrument; a slit with a sterile knife was made through the visceral mass into the stomach, and then about 1/10th cc. of the liquid in the latter cavity was withdrawn in a recently-drawn-out glass pipette. This was evenly spread over the surface of a recently poured plate of Griinbaum’s neutral-red, bile-salt, lactose agar. At the same time a similar quantity of liquid was taken up in the same pipette and inoculated in a recently boiled tube of sterile milk; a different pipette was used for each mussel. The plates were incubated for 24 hours at a temperature of 42°C. The milk tubes were heated to 78°C. for 20 minutes to destroy vegetative forms of bacteria, and they were then incubated for 24 hours at 42°C. under anaerobic conditions (in an atmosphere of hydrogen). The results of the primary surface inoculations on the neutral-red agar are given below :— SEA-FISHERIES LABORATORY. 331 Muss. No. or CoLon-LIKE COLONIES. WHITE CoLONIES. LS a ee NOM gece bay eae seat, 12 2 eRe ee Oe aoa Suc naesees 4 PM | Ee ese encivo « 36. 7 ~ with many diffuse red patches 6 Foes . IBA Lae 3 with several diffuse red ‘patches with 5 diffuse red patches 8 ae Beets) fae | s oe ....| numerous with several diffuse red. patches 9 Ad ee tt ails as. a “with numerous diffuse red. patches 10 Es AOOWL O20 Lee .cs on ises cere ee v0 == The significance of these results is that unpolluted mussels or oysters taken far out at sea contain no bacteria ‘in their stomachs which grow on neutral-red agar. This is also true of non-sterile but uncontaminated sea water. The great majority of the organisms growing on this medium are such as are found in sewage, and indeed are those that have their normal habitat in the human intestine. The diffuse patches are formed by the fusion of numerous “ colon-like 99 colonies. 332 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. The object of the anaerobic milk cultures was to demonstrate the presence of a spore-forming anaerobic bacillus—the B. enteritidis sporogenes of Klemm, or a nearly related form. All the ten cultures made gave positive reactions; that is, the milk was curdled and abundant gas formation took place, breaking up the curd in the characteristic manner. This again is presumptive evidence of sewage pollution since unpolluted shellfish and unpolluted fresh or sea water do not readily give this reaction. Bacillus coli, the presence of which is now regarded as indicative of sewage pollution, grows on neutral red agar as deep red, and large colonies. Not all these “colon-like”’ growths are, however, produced by the typical B. coli. Eleven of these colon-like colonies were, therefore, selected from the ten plates, and from them pure sub-cultures were made on nutrient agar. After 24 hours incubation at 42°C. these secondary cultures were examined in detail. The presence or absence of motility of the bacilli was observed microscopically, and each sub-culture was inoculated in 7 different media (bile salt glucose broth, glucose broth, lactose broth, mannite broth, cane sugar broth, glycerine broth, and litmus milk). These tertiary sub-cultures were again incubated for 48 hours at 42°C. At the end of this time six gave the reactions for the typical Bacillus coli. Therefore, about one-half of the discrete colonies identified as ‘ those of B. colt. Neutral-red, bile-salt lactose agar not only affords ‘colon-lke ” proved to be an easy means of picking out organisms which are probably B. coli, but it also distinguishes these from organisms belonging to the Gaertner and typhoid groups. These latter grow on the medium in question as white SEA-FISHERIES LABORATORY. Soe translucent colonies. Particular attention was paid to these latter organisms and eight were selected and examined in pure sub-culture as in the case of the “ colon-like ”’ colonies. Most of these colonies were those of aberrant organisms which could not be identified. Two of them gave most of the reactions characterising Gaertner’s bacillus, and may possibly have been this microbe. One of them, however, (isolated from mussel No. 2), was of much oreater significance, and had the following characters : 1. It formed a round, slightly raised, translucent colony on neutral red, bile-salt, lactose agar. . It was motile. It formed acid only in bile-salt broth. Formed acid in glucose broth. . Shghtly discoloured lactose broth. . Formed acid in mannite broth. . Gave no reaction with cane sugar broth. ONAN cw @w . Formed acid in milk. The agglutination test was made for me by Mr. Lewis of the Pathological Department at Liverpool University. Twenty-nine parts of an emulsion of the _ bacillus were mixed with one part of a serum taken from a patient suffering from enteric fever, and which gave a positive result with a known strain of Bacillus typhosus. This was kept under observation for half an hour. At the end of this period well-marked clumping of the bacilli took place. All these reactions are characteristic of Bacillus typhosus the specific germ of enteric fever and I think it highly probable, therefore, that this microbe was present in mussel No. 2. It is only in comparatively few cases that B. 384 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. typhosus has been isolated from shellfish, though there is little doubt that it is often present. The microbe is one which possesses little vitality in sea water (Herdman and Boyce), or in the alimentary canal of the mussel or oyster (Klein), and its presence, therefore, indicates recent, and therefore, dangerous pollution, a result which is indeed apparent from the unusually large numbers of Baczllus colt present in the mussels examined. A quantitative analysis of the bacteriology of the mussels was also made (as regards B. colz) by the method of decimal dilutions of Dr. A. C. Houston, Bacteriologist to the Royal Commission on Sewage Disposal. Five mussels were taken and removed from their shells with sterile precautions. The liquid from the shell cavities was made into an emulsion with the bodies of the shell- fish and this emulsion was made up to the volume of 500 cc. with sterile water. 1 cc. of this liquid, therefore, contained 1/100th part of one mussel. The liquid was then diluted so that 1 cc. contained 1/1,000 part of one mussel and the process was repeated. In this way emulsions were obtained which contained :— A. 1/100 part of a mussel. B. 1/1,000 part of a mussel. C. 1/10,000 part of a mussel. D. 1/100,000 part of a mussel. 1 ce. of each was then inoculated on neutral red agar as before, and also in milk under anaerobic conditions. A contained about 20 colon-like organisms. B 5 55 6 55 34 C er 8 2 $9 Fe D was sterile. One of the colonies in C was produced by B. colt. This organism was, therefore, present in 1/10,000 part of a mussel (average of five examined). —————— SEA-FISHERIES LABORATORY. 335 The enteritidis reaction was given only by emulsion A. B. coli was, therefore, present in 1/10,000 part of a mussel but was absent in 1/100,000 part. I think that the above results leave no room for doubt that the mussels from the bed near the St. Annes Sewage Outfall are most gravely polluted by micro-organisms of intestinal (or faecal) origin. 2.—REPORT ON AN EXAMINATION OF THE MussEt BEDS AT MORECAMBE. An analysis of mussels from the “ Ring-Hole,” Morecambe, was made in July of this year, and a Report was presented to the Chairman of the Joint Committee. That Report was only a preliminary one, and was only intended to show whether or not it was desirable to make a more exhaustive examination. It was evident that further enquiry was necessary, and on 15th September, at the time of the low spring tides, Mr. Scott and I visited Morecambe for this purpose. I desire here to state that every assistance was given to us by the Local Sanitary Authority, and that no information that we asked for was withheld. On this first visit we were accompanied by Alderman Thomas Baxter, Alderman Snowden, the Chairman of the Sanitary Committee, Councillor Miller, Inspector Lamb and Mr. E. Gardner, the local Fishery Officer. We saw the sewer outfalls and some of the mussel beds, and collected a number of samples from the vicinity of the main sewer outfalls, from “ Baiting-Knot” Skear, and from Ring-Hole. These samples were taken at about 6 p.m., near the time of low water. Again, on 5th October, Mr. Scott and I made another visit to Morecambe and met Dr. Watterson, the 336 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. Medical Officer of the Borough. At this time the men were working on the outer Heysham Skears and we there- fore visited the latter at 5 a.m., the time of low water on the morning tide. Further samples were taken from “ Great-Out”’ and “ Little-Out ” Skears, and from Ring- Hole. Samples of sea-water were also taken from off Great-out Skear, from off Baiting-Knot, from over the main sewer outfall (at that time covered), and from Ring- Hole. On this visit we also saw the main sewage culverts and the purification works. | Bacteriological analyses of the shellfish so collected were made in the usual manner. The results show that Bacillus colt was present in practically all the mussels examined. But in no case was the degree of contamina- tion considerable. There was a noticeable difference in the results obtained from this analysis and those from the analysis of July 19th. Im this latter case the mussels (which we did not personally collect) were apparently not a representative sample from the Morecambe mussel beds, although they may have been taken from a place from which mussels are sent to the markets. To describe a mussel as dangerously polluted merely because it contains Bacillus colt would be quite unjustifi- able. This microbe is not, in such circumstances, so far as we know, dangerous to health. Its presence in a shellfish merely. indicates that the latter is living in sea- water which is exposed to some degree of sewage contamina- tion. Its presence always indicates the possibelity that the shellfish in which it is found may, under certain circumstances, come to harbour microbes of a nature strictly pathogenic, such as the typhoid bacillus. But when the number of B. colz in a mussel is few then this possibility is remote. When the number is large, or when the pollution is notorious (as in such cases as those of the SEA-FISHERIES LABORATORY. 337 mussels at Egremont, Rock Ferry, or St. Annes) then we may reasonably conclude that the shellfish should not be used for human food. In every sample of mussels from the coasts of Lancashire, Cheshire and Wales examined so far, Bacillus colt has been found; and much more extensive investigations carried out by the Sewage Com- mission with reference to oysters have given the same result. “If,” say the Commissioners, “it should be seriously contended that the mere presence of B. coli or coli-like microbes in an oyster should condemn it, few oysters would probably escape condemnation.’ Probably the same conclusion holds good for mussels also. At the present time about 90 per cent. of the sewage of Morecambe is treated by the biological or septic method of purification. The remainder passes into the sea as crude sewage. There can be no doubt that the presence of this crude sewage is objectionable, but I am assured that, in a short time, all the Morecambe sewage will pass through the septic tanks. There is some diversity of opinion among bacteriologists as to how far this method of treatment of crude sewage removes the danger to health which might be incurred should the effluent go near a shellfish laying. But the general opinion is that the chance of dangerous bacteria (such as Bacillus typhosus) finding their way into the effluent is greatly lessened. This is specially the case when the effluent is very largely diluted with sea water before reaching shellfish beds. When the present Morecambe sewerage scheme was sanctioned by the Local Government Board, this was apparently considered, for the main sewage outfall is so situated that the effluent is carried well out to sea and is enormously diluted on the ebb tide before coming near the mussel beds. Shellfish are dangerous to health when they X 3388 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. contain toxic quantities of Bacillus typhosus (producing enteric fever), or possibly B. enteritedis (producing ~ Gaertner poisoning). These organisms must, in any circumstances, if they are present at all, always be present in sewage in small numbers; and when the latter is intercepted in storage culverts and septic tanks, and then turned into the sea and greatly diluted, the chance that a mussel can be dangerously infected becomes very small. Most people will say that neither crude sewage, nor a purified effluent, should find its way anywhere near a shellfish bed. One must agree with this opinion, but it is rather to be regarded as a “counsel of perfection.” When practicable methods of sanitary engineering and sewage disposal are being considered, and when one thinks of such a densely populated littoral as that of Lancashire, it must be apparent that the ideal of removing sewage so that it cannot approach mussel beds is quite unattainable. The general conclusion, then, is that the mussels from the skears and beds at Morecambe are not polluted to such an extent as to constitute serious danger to the health of those consuming them for food. In view of the importance of the interests involved, I give below the evidence on which this opinion is based. The Morecambe Sewage System. The accompanying chart shows the positions of the mussel beds and the sewer outfalls. Altogether six sewers empty into the Channel. No. I., which hes to the West of the West End Pier, is the main sewer, and carries seawards the treated effluent from the purification works. It is a 24-inch iron pipe, and terminates near the skear called “Seldom Seen,” at the low water mark of spring tides. No. II., the “ Midland Culvert,” is situated to SEA-FISHERIES LABORATORY. 309 the East of the old harbour; it serves the Winter Gardens, the Midland Hotel, and a small group of houses near this. No. III., the “ Queen Street” sewer, runs out obliquely from Queen Street, near the Central Pier. Nos. IV. and V., the “ Calton Terrace ” and “ Thornton Road ” sewers, le to the East of the Central Pier. No. VI., the “ Bare Sewer,’ is not shown on the chart; it serves the township of Bare. Nos. II. to VI. deliver crude sewage, and Nos. IIT. to VI. are 12-inch iron pipes. They all terminate at low-water mark of ordinary tides. Taking a normal population of 11,000 and an average water supply of 20 gallons per head per 24 hours, we find that the main sewer outfall delivers 200,000 gallons of purified sewage, and the other outfalls, 20,000 gallons of crude sewage per 24 hours. Probably the contribution of the Old Harbour to the pollution of Ring-Hole may be neglected. At the present time the Harbour is strictly private ground, and is used only for breaking up old warships and other superannuated vessels. It is largely silted up, and though the bottom at low water looks exceedingly foul, it is probable that this foulness is more apparent than real. At any rate, the only sewage matters issuing from it are those produced by the workmen employed on the vessels. As a source of pollution the Old Harbour does not count for much, and whatever evil exists could easily be remedied. Sewers II. to VI. represent the outfalls of the original Morecambe sewerage system before the new scheme was brought into operation. For some years prior to 1897 the Local Government Board had urged on the Borough Council the desirability of adopting a system of sewage purification. In 1897 they expressed the opinion “that untreated sewage should not be discharged anywhere in Morecambe Bay,” an ideal which, except at Morecambe, 340 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. the Local Sanitary Authorities have not yet attempted to realise. In 1898 Mr. H. Bertram Nichols, C.E., designed the present system of sewerage. At that time the Cameron method of septic purification was in high favour, and it was decided to adopt this. The scheme provided for the collection and treatment of the sewage (almost entirely domestic) of Morecambe, Bare and Torrisholme— an estimated population of 11,000, with an annual influx of 30,000 visitors—at an estimated total cost of £60,000. Really the system was designed to cope with a population of 60,000 persons, and for an average daily water supply of 20 gallons per head. The main sewers are laid along the back of the town, and terminate in two main outfalls, iron pipes of 21-inch and 24-inch diameter respectively. These open into two culverts, which are designed to contain an aggregate night flow of 400,000 gallons. The culverts open into a well, and the sewage, after being screened so as to remove solid matters, 1s raised by means of four centrifugal pumps worked by electric power to the level of the channels leading into the septic tanks. There are eight rectangular tanks, each of which is covered in and airtight. After passing through a “ detritus chamber,” in which much of the grit from road washings is allowed to settle, the sewage passes through special inlet pipes into the tanks themselves. Here it is allowed to remain, and the well-known septic process of purification goes on. The saprophytic and nitrifying bacteria normally present in the stale sewage act on the organic matters present, and most of the solids present in suspension pass into a state of solution. Organic matter is broken down and resolved largely into harmless nitrites and nitrates. A certain amount of sludge settles at the bottom of the septic tanks, but the rate of accumulation of this 1s very SEA-FISHERIES LABORATORY. 341 slow, and the tanks require to be cleaned out only at very long intervals. The result is the production of an effluent which, if the tanks are properly worked, is almost clear, is non-putrescible, and which does not cause a nuisance. The effluent after leaving the septic tanks passes into an underground storage culvert which has a storage capacity of 800,000 gallons. At the outlet end of this storage culvert is a penstock chamber and a chamber provided with a tidal valve. The culvert discharges into a 24-inch iron pipe, the liquid in which is under pressure from the head of sewage in the culvert. The culvert was designed to remain full, or partially full, of effluent for nine hours, and to discharge in three hours. In actual practice the sewer outfall is opened three hours after, and closed four hours before high water. The main outfall sewer runs out over the sands to a point at Seldom Seen Skear at the low-water mark of spring tides and there discharges. At Morecambe the duration of the ebb is much greater than that of the flood. At spring tides the flood lasts for 3 hours and 15 minutes on the average, and at the neaps for 4 hours and 40 minutes. Hxtensive float experiments were carried out to determine how far the sewage would be carried by the ebb before the tide turned.* Drift bottles, and large wooden floats provided with flags so that their movement could be observed, were used. The information derived from these float tests showed that the sewage would be carried well out to sea before the turn of the tide, and would not return to Morecambe. Many of the bottles * The Hngineer’s report is:—‘‘ From information derived from the float tests on the 10th February, and 16th and 23rd March, 1897, and between 25th of August and the 3rd September last (1898), there is no doubt that the best point of discharge is at ‘‘ Seldom Seen,”’ a point on the north side of the fishing baulks lying north of the Battery Inn. At this point the tide at half-ebb would be sufficient to carry away une sewage coming from Morecambe far out to sea before the tide turned,’’ 342 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. were carried out of the Bay entirely and were found at Drigg, on the Cumberland coast. Others went over to Grange, and, no doubt, after oscillating for some time on the ebb and flood would ultimately leave Morecambe Bay. Whatever way the sewage finally went, the dilution in Heysham Lake and the Lune would be enormous. Com- parative analyses of the sea-water on the ebb and flood would show, I think, that sewage bacteria though found in the ebb, in the Morecambe Channels, would be absent, or at least very few, in the ensuing flood. It was intended to make these analyses, but the work was too extensive in scope to be undertaken at the time. Such comparative determinations of the numbers of bacilli in sea-water have been made in various places, as, for instance, in the estuary of the Thames and in Kiel Harbour, and the results are both interesting and practically important. | Bacteriological Analyses. On the occasion of our first visit six samples were collected. Two were taken from near the main sewer outfall, two from Baiting Knot, and two from Ring-Hole. All the samples, with one exception from the top of Baiting Knot, were raked by Mr. Ed. Gardner by means of the “long craam.” In each sampling several drags were made, and the total sample was mixed and about a dozen mussels put into a sterilised tin. The tins were placed in ice until the analysis was made (some twelve hours afterwards). Four mussels were then selected at random from each sample-—24 in all, and about yo cc. of the stomach contents of each was plated on neutral-red, bile-salt, lactose agar (Grinbaum’s medium). After 48 hours’ incubation at 42°C. the plates were examined. Each alternate mussel was also examined for the presence of anerobic spore-bearing bacilli. SEA-FISHERIES LABORATORY. 343 The results of these primary inoculations are shown on the following table. It will be seen that the “ enteri- tidis reaction” was typical in each of the 12 anerobic cultures made. ‘The colonies which resembled those produced by Bacillus colt were counted, and the numbers present in 75 cc. of the stomach juices of each shellfish vary from 14 downwards. On two of the plates no “colon-like”’ colonies were present. In some of the countings the number is to be regarded as a minimum one on account of the fusion of colonies. 344 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. lst ANALYSIS. Primary CULTURES ON NEUTRAL-RED, BILE-saLtT, LAcTOSE Locality. Between ‘‘ Seldom Seen” and “Reap ” Skears. N. from “ Reap ” Skear. 99 99 N. Side of “ Baiting i Knot.”’ 99 99 From top of “ Baiting Knot.” 99 99 N. Side of “ Ring Hole.” 9? Top end of “ Ring Hole.” Mussel. eae rece me aes Oe AGAR PLATES. “< Colon-like ’’ Colonies. 4 5 3 several patches 5 patches 5 Z many fused . several patches ... O i 4 2 Enteri- White tidis Colonies. re- action. .numerousand ... + fused. as sn I patch ee fe) I patch Beer = . large patches oO og Sc . many patches fe) PE aT 2 2 2 i tt fe) B numerous ... + fused colonies fo) . many patches ... + . several patches a O cee ate ife) sete fo) ee = fe) Ss . numerous and fused. ; (e) ie a fe) SEA-FISHERIES LABORATORY. 345 Thirteen of the colonies identified as belonging to the colon group were then subcultured on nutrient agar in sloped tubes, and after 48 hours’ incubation these growths were subcultured in bile-salt broth, glucose, lactose, mannose, and cane sugar broths, and in litmus milk. Again, after 48 hours’ incubation the cultures were examined. The results of these tertiary subcultures are shown on the next table. It is obvious that the colonies Nos. 6 and 14 are not those of B. colt. In two cases (7 and 11) the bacilli were non-motile, and in three cases (1, 6, 7,) the motility was very feeble. But at least six out of the thirteen colonies examined in detail proved to be those of typical B. colt. | The white colonies present on the primary plates did not belong to bacteria possessing any special significance. Ist ANALYSIS. RESuutTS oF TERTIARY SUBCULTURES FROM PRIMARY PLATES. Mussel. a Glucose. Lactose. Mannose. Caine Milk. Motility Salt. Sugar i PERM anos... AP Ln are) 6... ° Oo ate. N.. PE 2 Pees A) i APS. | sae, aS ag ale 3 Riek A es A es: a fe) ac a 6 AEP E NE Pease Seed es ale fo) ac Rar 6 Be MN eae te aed CO Ss.qhyt aoie O fo) + i Dees a AP ORNs. eA Oe ye.) aS O ac ale 7 een) dee hea. a ag ac — 7 pears dno wr are ly) ag O ac a 7 BA Rtae eae Von AP sas, ane O ac a 9 MNO D i), A Re aa PY... aL d ac ae Men A eA an, AO 635° Oe ac — A ee. Anse aw nnsel dee s.s || a Oo ac ste Pe Sees A ae A. A oe AL Ee te EXPLANATION OF SYMBOLS :— a = acid; g = gas; c = clot; d = discolouration. 346 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. The second analysis was conducted in precisely the same manner. A sample of about 20 mussels was collected from Great-out and Little-out Skears, one mussel being taken from each part of the skears visited. This sample was therefore a thoroughly representative one. One drag was then made in the middle of Ring-Hole, and a similar quantity was taken from the sample. Five mussels from each of these samples were examined as before. In the case of the Ring-Hole shellfish the enteritidis reaction was not tried for. The results of these primary inoculations are shown on the next table. Distinctive white colonies were absent in each case, and the numbers of colon-like colonies vary from 20 down- wards. In the case of two of the Outer Skear mussels the enteritidis reaction was atypical. 2nD ANALYSIS. PRIMARY SUBCULTURES ON NEUTRAL-RED, BILE-SALT, LacrosE AGAR PLATES. ‘“‘ Colon-like”’ White Enteri- eye ATES Colonies. Colonies. Men “ Ring Hole ” Ieee about 20 fo) 99 2 99 20 O 99 3 14 O x 4 9 0 ” 5 Zh ae Oo some patches Ont. (Skears 6 4 fo) . not typical 99 i 7 fe) ate ce 8 16 O . not typical ts Eee 7 Ms O + some patches e fe) 14 O + SEA-FISHERIES LABORATORY. 347 As before, a number of the colon-like colonies from the primary plates made from the Outer Skear mussels were subcultured. The results are given below in detail. It is evident that colonies 8, 9, 9, 10, 10, are not those of B. colt, while there are other four in which motility was not observed. Four colonies are those of typical B. colt. This is a lower proportion than was observed in the case of mussels taken from the skears higher up the Channel, and therefore nearer to the sewer outfalls. It is what one might expect to find. The contamination of the outer Heysham Skears is less than that of Baiting Knot and Ring-Hole. By the time that the sewage reaches the Heysham Skears it has become so greatly diluted that there is a much less chance of sewage bacteria being ingested by the shellfish. The percentage of microbes indubitably identified as B. coli is also less, an indication that the micro-organism undergoes some change as a result of its sojourn in sea-water, or perhaps perishes altogether. 2nND ANALYSIS. REsvutts oF TERTIARY SUBCULTURES FROM PRIMARY PLATES. Mussel. ee Glucose. Lactose. Mannose Cane wink. Motility. Salt. 4 * Sugar. Pree AO ate, Ae ae 6c) dy ave + OUR. AR). cae Ae? Ga) VA) cae) WC ts PREMERA oe. ANP ec. ALM ee BO 4 ELI ate eS iss AS ws AG i. ag Omri aac — pues OF >. Oo 23270) 7.4.9 0 Oe rar. tare at Pe 1 AS A oes, AL Ou Gs vase = Pee 8 AO 2. AE i AL Ol ae ac 3+ Beene, AS... AUS ae. a8 OB \aeusanc — ayo ind AP Ns NAL)... ag fe) ed ai3 Q.. a a a a a O == HO! a a Ale grt = | . ] t we =) * { : z = Le 5 i ~ ; —. - if x , t ! \ ’ n . ' . 1 5 a ¥ . a t se al 4 ‘ - j . is { Aa 0, i i i « in qi ‘ i t a Das i Ren, lS ae 2K, ee eee 1 y x x . y - . “= 1 ‘ i ’ i v =) 9 Mussels DEGANWY MORFRAX. PARADE \ 5 mvt CONWAY Cuarr VI, SIME WGI! (RUA ROP oir CONWAY ESTUARY SHEWING POSITIONS of MUSSEL BEDS AND SEWER OUTFALLS SEWER OUTFALLS: 7 LLAN DUDNO JUNCTION Conway River: 1 ce. water from below Deganwy. Conway RivER: 1| ce. water from off Bodlondeb Point. Conway River: 1 cc. water from opposite Conway. O71 L.M.B.C. MEMOIRS. No. XV. ANTEDON. BY HERBERT C. CHADWICK, Curator of the Port Erin Biological Station, Hon. Lecturer in Marine Biology in the University of Liverpool. ANTEDON BIFIDA, Pennant (=Comatula rosacea, Linck, of Forbes and other authors), is the most familiar example of the Class CrinoipEa found in British seas. Of the six species of the genus recognised as British, five appear to be confined to the deeper waters of our seas, but A. bifida has been recorded from depths of a few fathoms only at many points around our coasts. In the L.M.B.C. district it occurs in large numbers off Cemmaes Bay, North Anglesey, at a depth of 10 fathoms, and also off Bull Bay. It is abundant around the South end of the Isle of Man, and is often found clinging by means of its cirri to the wicker creels used by fishermen for the capture of lobsters and crabs. The fishermen state that specimens are always more numerous on the creels after stormy weather. With abundant aeration and a moderate amount of light, Antedon may be kept under observation in tanks for months. It is not usually an active animal. By means of its cirri it clings tenaciously to-stones, alge, hydroids, &c., the arms being widely spread horizontally with the tips more or less flexed towards the disc (PI. I., fig: 1). When disturbed it swims actively and with strikingly graceful movement, the two arms of each pair being invariably flexed and extended alternately (Pl. I., Z 372 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. fig. 2). The colour of Antedon is very variable. Some specimens are of a deep reddish purple, uniformly distributed over both disc and arms, but the majority are clouded and spotted with rose, orange, and yellow tints. The colouring matter is highly soluble in fresh water, alcohol, and glycerine, but not in ether. Its properties in Antedon bifida and other species of the genus have been described by Moseley (1), Krukenberg (2), and MacMunn (8), to whose papers the reader is referred.* EXTERNAL CHARACTERS. Antedon is composed of a central disc and five pairs of long and flexible arms fringed with pinnules (Pl. L., fig. 2). The disc consists of a shallow cup or calyx, composed of a number of calcareous plates firmly articu- lated together, and a lenticular visceral mass, lodged within the cavity of the calyx, and containing the central parts of the ambulacral, nervous, and vascular systems in addition to the alimentary canal. A number of jointed appendages called cirri, each terminating in a claw, are attached to the sloping sides of the central plate of the calyx (Pl. I., fig. 3, cz.). The opposite face of the disc 1s the “tegmen calycis” (PI. II., fig. 24, tg.cl.). Near its centre is the mouth (méh.), surrounded by five shghtly elevated valvular folds (Pl. II., fig. 28, v.f.). The tegmen calycis is traversed by five ambulacral grooves, fringed with delicate tentacles (Pl. II., fig. 24, amb. gr.), which radiate from the mouth to the edge of the disc and there bifurcate to enter and traverse the entire length of the ten arms and all their pinnules except the first or proximal one (fig. 24). In one of the five interradial * The black numerals in brackets refer to the list of references given at the end (p. 410). ANTEDON. 373 portions into which the tegmen calycis is divided by the ambulacral grooves there is a conical projection, the anal funnel (Pl. II., fig. 24, an. fl.), at the apex of which the anus (an.) is situated. ‘The margin of the anal aperture bears minute papille. With the aid of a good lens a number of minute pores may be detected in the tegmen ealycis. These are the external apertures of the ciliated funnels of the water vascular system. Orientation— When Antedon is at rest with the mouth directed upwards and the anal interradius nearest to the observer, it is customary to call the opposite radius anterior. The four remaining radii are thus right anterior, right posterior, left posterior, and left anterior. In correspondence with this designation of the radu the interradi are called right anterior, right postero- lateral, posterior (or anal), left postero-lateral and left anterior respectively. To maintain this orientation when the animal is viewed from the aboral surface the posterior (anal) interradius must be turned away from the observer. THE SKELETON. The skeleton of the calyx 1s composed of a centro- foteieplate (Pl. I, fie. 3; Pl. V., fig. 02; Pl. VI., fig. 59, ent. dr.), to the convex aboral surface of which the cirri are articulated; five radial plates (Pl. V., fig. 52; Pl. VI., _ fig. 59, rd.), which form a pentagon and rest upon the plane oral surface of the centro-dorsal; and five basal plates which are fused together to form a single plate, the een 1. fies 17 and 18; Pl. V., fig. 52; -Pl. VL, fig. 59, ros.), which roofs over a bowl-shaped cavity in the centro-dorsal (Pl. I., fig. 19). To these must be added, as contributing to the support of the visceral mass, the two most proximal joints of the arms, called respectively the first and second primibrachials (Pl. I., fig. 3; Pl. V., 374 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. fig. 52; Pl. VI., fig. 59, pmb. 1 and pmb. 2). The latter joint is axillary, and supports, in each radius, two long series of secundibrachials (Pl. I., fig. 3, sec.), which form the skeletons of the five pairs of arms, and to these the much shorter series of joints which support the pinnules are articulated. Several specimens of Antedon with only eight arms have been observed by the writer, and one with twelve was described by Dendy (4). The eight-armed condition results from the absence of one of the radii, while the two extra arms of the twelve-armed specimen resulted from the bifurcation of two of the normal ones. In each of these the second secundibrachial became an axillary, similar to the second primibrachials, and of which each facet bore the long series of, in this case tertibrachial, joints forming the arms. In many species of Antedon one or both facets of the primibrachial axillary bear a series of two or three secundibrachial joints, the second or third of which is an axillary, and may in turn bear two or three tertibrachial joints, the second or third of which is also an axillary. In this way the large number of arms borne by many tropical species arise. All the skeletal plates are composed of more or less densely reticulate calcareous matter, to which the name “stereom”’ has been given. This reticulate structure may be seen in its simplest form in the skeletal plates of the larva (Pl. VI., figs. 66, 67, and 69), in which the reticulations are all in one plane, but in the much more massive plates of the adult they form a sort of sponge work, the meshes of which vary in shape and size even in the same plate. The Centro-dorsal Plate—The form of this plate (Pl. I., figs. 3 and 19) resembles that of a shallow bowl. It is of considerable thickness; and its outer margin, as well as that which bounds and slightly overhangs the ANTEDON 375 comparatively small cavity, is pentagonal, with rounded and slightly upturned angles (fig. 19). In the peripheral - portion of the bottom of the cavity may be seen the inner ends of a number of minute canals, through which mewmencocoss pass to the cirri (Pl. V., fig. 02; Pl. VL., fig. 59). The central portion of the aboral face of the plate is flat or only slightly convex (Pl. L., fig. 20). The peripheral portion is wholly occupied by a number of sockets for the articulation of the cirri. Those which border the flattened central portion of the plate have a nearly circular outline, while the more peripheral ones become more or less angular, owing to close approxima- tion. At the bottom of each socket there is a minute papiullform elevation, perforated in its centre by the external opening of one of the canals already mentioned. The oral face of the plate is nearly flat. Shallow grooves traverse it at the interradial angles from the periphery to the margin of the cavity, marking it out into five equal and radial segments (fig. 19). The Cirri.—These vary in number from twenty to Meamytoriy. Hach cirrus (Pl. I1., fig. 3; Pl. III., fig. 38) is composed of from ten to eighteen calcareous joints, the terminal one being in the form of a claw, immovably articulated with the penultimate joint. The proximal and next succeeding joints are cylindrical and shorter than the remainder, which are compressed from side to side and slightly constricted about the middle of their length, the latter character becoming less marked, almost to disappearance, in the terminal joints. A minute canal, continuous with one of the canals of the centro-dorsal plate, traverses the whole series of joints and ends blindly in the terminal claw (fig. 38, ax.cn.). All the joints, except the penultimate and terminal ones, are united by elastic hgaments, and the interarticular spaces 376 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. between the joints are widest on the side nearest the vertical axis of the animal, towards which the whole cirrus is always more or less flexed. Radial Plates.— These plates (Pl. V., fig. 52; Pl. VL., figs. 56 and 59, rd.), closely adhering to each other by their lateral faces and together forming a well marked pentagon, are also adherent by their aboral faces (figs. 52 and 59) to the oral face of the centro-dorsal plate. Kach radial plate is of triangular form. Its slightly truncated apex, forming the internal face of the plate (Pl. I., fig. 4), is turned towards the vertical axis of the animal, its base forms one of the sides of the radial pentagon, while its lateral faces are in close contact with its fellows on either side. The lateral faces are flat, and each presents a fairly large aperture in the angle formed by the aboral and internal faces (fig. 6). Two apertures of slightly larger size appear in the latter face, which is small and irregular (fig. 4). The external face (fig 5) presents an oval aperture in the middle of its width, and a well marked transverse ridge divides this face into upper and lower portions. The former is divided into two pairs of fossee by an incomplete transverse ridge and the continuation of two converging ridges, which are more conspicuous on the oral face of the plate (fig. 7). The upper, deeper pair lodge the proximal ends of the powerful flexor muscles, while the lower, shallow pair afford attachment for the proximal ends of the inter- articular ligaments. The lower (aboral) portion of this face is occupied by a single fossa which lodges the proximal ends of an elastic extensor hgament. The oral face of the plate presents two curved ridges (fig. 7), the shorter ends of which approach each other along the median line and form the median edges of the pair of fossee which lodge the flexor muscles. The apertures ANTEDON. uel on the external, internal, and lateral faces of the radial plates belong to a system of canals which radiate from the central funnel-like space enclosed by the five plates, and also form an annulus around it. These canals lodge the radial cords and commissures of the apical nervous system, and their courses will be more readily understood in relation to that system. The Rosette.—This plate (Pl. I. figs. 17 and 18) assumes the form of a disc with a circular aperture in the centre, and a margin divided by deep clefts into ten radiating processes. Of the latter, five are triangular and le in nearly the same horizontal plane as the disc (fig. 8); whilst the alternating five have nearly parallel margins, which are inflected in such a way as to form a shallow groove, the whole process being markedly reflected in the direction of the centro-dorsal plate. The exact form of the rosette can only be made out after dissociation from the radial pentagon by maceration in a solution of caustic potash. When in situ it almost completely shuts off the funnel-shaped cavity enclosed by the five radials from the cavity of the centro-dorsal plate, the circular aperture in its centre being the only communication eeyewde. 02; Pl. V1., fig. 59). The five triangular processes are interradial, that is to say, they are directed towards the sutures between the radials; the alternating processes are radial, and abut upon the axial faces of the radials, from which also a number of irregular calcareous outgrowths pass to the oral face of the rosette (Pl. VI., fig. 59). First Primibrachial Plates.—Hach of these is an ellipsoid disc-like plate of moderate thickness (Pl. L., fig. 3, pmb. 1; figs. 8 and 9), having two nearly parallel faces, of which the inner, or axial, has much the larger area (fig. 8), and articulates with the outer, or 378 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. abaxial, face of the corresponding radial. ‘he axial face is divided transversely by a well-marked ridge into two portions of unequal size. The larger portion is on the oral, or upper, side of the ridge, and is sub-divided by a median vertical and two oblique and less prominent ridges into two pairs of fossee, of which the upper pair are the deeper. The smaller portion of the face is on the aboral, or lower, side of the ridge, and is wholly occupied by a broad and deep fossa. At the point of intersection of the transverse, vertical, and oblique ridges is the oval opening of a canal which traverses the plate from face to face. The smaller abaxial face (fig. 9) is of simpler character, and presents only one pair of fosse, divided by a vertical ridge which passes round the opening of the above-mentioned canal, and at its upper, or oral, end is continuous with a shghtly raised margin, which bounds the fossee above. The oral margin of the plate presents a well-marked notch when viewed from this face. Second Primibrachial Plates.—These plates resemble the radials in general form (PI. 1., fig. 3, pmb. 2; figs. 10 and 11). Hach one presents a triangular figure when viewed from above or below, and has three articular faces. Of these, the axial closely resembles the abaxial face of the first primibrachial, with which it is articulated, having a single pair of lateral fossee divided by a vertical ridge, which also passes round the transversely oval aperture of the axial canal. The surfaces of the lateral fossze slope away slightly from the vertical ridge, so that when the latter is in close contact with the corresponding ridge of the first primibrachial the second primibrachial has a slight range of lateral movement upon the first. A median crest and a pair of divergent lamellz project from the upper, or oral, margin of the axial face to form parts of the two oblique surfaces of articulation (fig. 11). ANTEDON 379 In general plan these latter correspond with the articular faces of the radials and first primibrachials, there being a strong transverse ridge that separates a deep fossa on its aboral side from two pairs of fosse on its oral side (fig. 10). The divergent lamelle described above form vertical dividing ridges between the latter. The radial canal, which has been seen above to traverse the first prumibrachial, enters the second and immediately bifur- cates, and the oval apertures of its two branches appear on the corresponding oblique articular faces at the point where the transverse ridge is joined by the vertical one. Interradial Plates.—In some specimens of Antedon three or four small interradial plates are found in the interradiil between the axillaries. The Arms.-The arms (Pl. I., figs. 1, 2 and 3) are rather slender and taper gradually to extreme tenuity. Kach arm is composed of a long series of joints or segments (figs. 3 and 21), placed end to end and bound together by muscular and ligamentous fibres (Pl. V., fig. 00). These segments are termed secundibrachials, and are of the same fundamental form throughout the length of the arm, each one being a short cylindrical rod, traversed by a minute axial canal (figs. 12 to 16, also fig. 21). The absolute length of the segments decreases very gradually from the base to the tip of the arm, those at the latter extremity being rather more than half the length of those at the former. The proportion of length to diameter presents considerable variation. ‘Thus, at the proximal end of the arm the length of the first few segments is less than half their diameter; in the middle region their length is less than twice their diameter; while at the distal extremity of the arm the segments become more and more cylindrical in form, and their length is at least four times their diameter. Viewed from the aboral 880 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. surface the outer margins of the first secundibrachials (Pl. I., fig. 8) are seen to be considerably longer than the inner, so much so that the angle of about 80° at which their proximal articular faces incline towards each other is widened out to one of about 130° between their distal faces. The outer margin of the second joint also is longer than the inner, and presents a shallow socket divided by a transverse ridge, in which a minute perforation appears. To this socket the first (oral) pinnule is articulated (fig. 3). With certain exceptions to be presently described, the succeeding joints present a similar inequality in the length of their margins, but the longer margin is alternately outer and inner, and the pinnule borne by every such joint is articulated to it. Hence, when viewed from the dorsal surface, the joints present the appearance of triangles, the apices of which point alternately to one side and the other (fig. 3). In the middle and more distal parts of the arm the inequality of the margins becomes less and less marked; and while in the proximal portion of the arm the articular socket of the pinnule encroaches upon the distal articular socket of the segment (fig. 14), in the middle and distal portions it is more and more restricted to the lateral face (fig. 15). The articular faces of the great majority of the secundi- brachial segments present very similar characteristics (figs. 12 to 16). Fig. 40). x aah x e fiat ~%?@ 1 oral Oh OFS = MtFarlane & Erskine, Lith. Edin? AUN TT DO Ne 3.x 650 PLATE IV 4 MtFParlane & Erskine, Lith Edin™ Fig. 44. x 320 asses CAE = - Hy a l AUN Bok HA Ny HS I im me i ua i | tees MS Nt} DURIBLY ee 1 I ten. ANTEDON. a= wr ---H T LS a ieee —, be = eres, O ee 2 S I = os a a a es tS lee aa a = ue) = 3 i iS) “al z ob - PLATE Ve i 1 \ rTad.nu. cen. cap. ex. lig. ies a0. x 40 7 ms SS MEM Hl 2 M ill MFarlane & Erskine Lith Edin® PLATE Via {