V\ac ^M^G HARVARD UNIVERSITY. LIBRARY OF THE MUSEUM OF COMPARATIVE ZOOLOGY. iOdo-Urt I ms- lDM^OI i IS^J Sottinal OF THE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. -■'W«.?-%^ VOLUME IV. (N.S.). ^ 1895-97. PLYMOUTH : PUBLISHKIJ BY THE ASSOCIATION. Agents in London : — Messrs. Dulau & Co., 37, Solio Square, W. oV^ I The Council of the Marine Biological Association ivi.sh it to he 2(nderstood that they do not accept respo7isibility for the accuracy of statements published in this Journal, exceptiny when those statements are contained in an official report of the Council. OCT 1 1897 CONTENTS OF VOLUME IV. (NEW SERIES.) PAOK Title . . . . . . . . i Contents . . . . • ... in List of Governors, Founders, and Members- August, 1896 . . . . ... 308 Report of Council— 1894-95 . . . . . ... 81 1895-96 . . . . . ... 302 Director's Report- August, 1895 . . . . ... 76 January, 1896 . . . . ... 219 August, 1896 . . . . ... 300 February, 1897 . . . . . . . 415 Allen, E. J. Faunistic Notes — January to June, 1895 . . . ... 48 Notes on Dredging and Trawling "Work during tlie latter half of 1895 164 The Reproduction of the Lobster . . ... 60 Additional Observations on the Nerve-elements of the Embryonic Lobster 70 Report on the Sponge Fishery of Florida and the Artificial Culture of Sponges . . . . ... 188 Supplement . . . • ... 289 The Protection of Crabs and Lobsters . . . . . 182 The Regulations of the Local Sea Fisheries Committees in England and Wales . . . . ... 386 Bassett-Smith, p. W. A List of the Parasitic Copepoda of Fish obtained at Plymouth . .155 Bethe, a. A Carcinus with a Right-handed Walking-leg on the Left Side of the Abdomen . . . • ... 144 Bidder, G. Note on Projects for the Improvement of Sponge Fisheries . . . 195 Brebxer, G. Algol ogiral Notes . . . . ... 179 ditto . . . . ... 286 Browne, E. T. On the Changes in the Pelagic Fauna of Plymouth during September, 1893 and 1895 . . . . ... 168 IV CONTENTS OF VOLUME IV. Butler, C!. W. pagk Rei)ort oil tlie Spawning of the Common Sole in the Acjuarium of the Marine Biologioal Asi^ociation's Laboratory during April and ilay, 1895 3 Cleve, p. T. Microscopic Marine Organisms in the Science of Hydrography . .381 Cunningham, .1. T. North Sea Investigations . . . . . . 10 ditto ditto . . . ... 97 Additional Evidence on the Influence of Light in producing Pigments on the Lower Side of Fiat-Fishes . . ... 53 The Reproductive Maturity of the Common Eel . . . . 87 Recent Reports of Fishery Authorities — The Scottish, Newfouiidland, and United States Reports . . 203 Physical and Biological Conditions in the North Sea . . . 233 On the Peculiarities of Plaice from different Fishing Grounds . . 315 GAR.STANC4, W. On Doris maculata, a new species of Nudibrauchiate Mollusk found at Plymouth . . . . ... 167 Contributions to Marine Bionomics — I. Tlie Habits and Respiratory Mechanism of Corystes cassivelaunus 223 11. The Functions of Antero-Lateral Denticulations of the Carajmce in Sand-burvowing Crabs . . ... 396 111. The Systematic Features, Habits, and Respiratory Phenomena of Potiumnus nusutus (Latreille) . . ... 402 GiJNTHER, R. T. Tlie Oyster Culture of the Ancient Romans, ivith Plate I. . . . 360 Hodgson, T. V. Notes on the Pelagic Fauna at Plymouth, Augu.st-December, 1895 . .173 Holt, E. ^Y. L. An Examination of the Present State of the Grimsby Trawl Fishery, with e-special reference to the Destruction of Inunature Fish. Revision of Tables . . . . ... 410 Lanke.ster, E. R. Oljituary Notice of the Right Hon. T. H. Huxley . . . 1 Nutting, C. C. Notes on Plymouth Hydroid.? . . ... 14fi Schiemenz, Dr. Paulus. How do Starfishes open Ov.sters 1 Translated from the German by E. J. Allen . ^ . . . ... 266 Stead, F. B. Preliminary Note on Tiuwling Experiments in certain Bays on the South Coa^^t of Devon . . - ... 90 Fourth Re])ort of the Danish Biological Station . . . .213 Note on a Specimen of Echmorkinus spinosns . ... 264 Variations and Relationships of the Flounder and the Plaice . , 293 Notes and SIemoranda Balance-sheet for 1894-95 ditto 1895-96 Steamboat Fund. List of Subscriptions Index 73 ts 307 418 419 New Series.— Vol. IV., No. 1— issued September, 1895.] [Price 3s. 6d. (Qd, 3fournal OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. -tSBii ''^"^^^ "ii ^^-.-,,'-?r5HBia» THE I'LYMOXJTH LAliOKATOKY. i PLYMOUTH : I'ltlNTEl) FOR THE MARINE UIOLOGICAL ASSOCIATION BY W. URENDON & SON, AND PUBLISHED BY THE ASSOCIATION AT ITS OFFICES ON THE CITADEL HILL. SENT FREE BY TOST TO ALL MEMBERS OF THE MARINE BIOLOGICAL ASSOCIATION; ANNUAL SUBSCRIPTION FOR MEMBERSHIP, ONE GUINEA. Agents in London : — Messrs. Dulau & Co., 37, Soho Square, W. PATRON. H.RH. THE PRINCE OF WALES, K.G., F.RS. OFFICERS AND OOUNCIL. Tlie Duke of Argyll, K.G., K.T., F.R.S. The Duke of Abercorn, K.G., C.B. The Earl of St. Germans. The Earl of Morley. The Earl of DuciE, F.R.S. Lord Revelstoke. The Tiigut Hon. Lord Tweedmouth. Lord Walsinghasi, F.RS. The Right Hon. A. J. BalfCTtr, M.P., F.RS. President. Prof. E. Ray Lankester, LL.D., F.R.S. Vice-Presidents. The Right Hon. Joseph Chamber- lain, M.P. Tlie Right Hon. Sir John Lubbock, Bart., M.P., F.RS. Prof. G. J. Allman, F.R.S. Sir Edward Birkbeck, Bjirt., M.P. Sir Wm. Flower, K.C.B., F.R.S. A. C. L. Gunther, E.«q., F.R.S. Prof. Alfred Newton, F.R S. Rev. Canon Norman, D.C.L., F.R.S. Sir Henry Thompson. Admiral Wharton, R.N., F.R.S. COUNCIL. F. E. Beddard, Esq., F.RS. Prof. F. Jeffrey Bell, F.Z.S. G. C. Bourne, Esq., F.L.S. Sir John Evans, K.C.B., Treas. RS. G. Herbert Fowler, E.sq. S. F. Harmer, Esq. Prof. AV. A. Herdman, F.RS. Governors Elected nrembers. Prof. S. J. Hickson, F.RS. J. J. Lister, Esq. Prof. W. C. McIntosh, F.R.S. P. L. Sclater, Es(i., F.R.S., Sec. Z.S. D. H. Scott, Esq., F.R.S. Prof. Charles Stewart, V.P.L.S. Prof. W. F. R. Weldon, F.RS. Robert Bayly, Esq. The Prime Warden op the Fish- mongers' Company E. L. Beckwith, Esq. (Fishmongers' Conijiany) Prof. BuRDON Sanderson, F.R.S. (Oxford LTp.iversity). Prof. Michael Foster, F.R.S. (Cam- bridge University). SirWM. Flower, K.C.B., F.RS. (Brit. As.soc. for Ad van cement of Science). Hon. Treasurer. E. L. Beckwith, Esastbourne to London, in order to assist us. After seven years, when the laboratory was in full working order, he asked us, on the ground of his delicate health, to accept his resignation of the presidency, which, reluctantly, we did. The successful launching of our Association, the assistance given to it by the Government, by the City Companies, and by other public bodies, are mainly due to the one fact, that we had at our head a man so profoundly trusted as was I'rofessor Huxley. NEW SKKIES. — VOL. IV. NO. 1. B 2 THE RIGHT HON. THOMAS HENRY HUXLEY. The brief description of the purpose of the Association, adopted and circulated by its authority, was due to him, and runs as follows : " To establish and maintain Laboratories on the coast of the United Kinf,f(lom, where accurate researches may be carried on, leading to the improvement of Zoological and Botanical Science, and to an increase of our knowledge as regards the food, life-conditions, and habits, of British food-fishes and molluscs." This is not the place to speak of the manifold labours of our late President in other fields. Our Association is but one of a hundred useful works in which his hand can be traced. But it is, above all, as the man who, without sacrificing the respect of his opponents, has gained for scientific thought a freedom and a hearing, such as were absolutely denied to it in his younger days, that Englishmen must ever remember Huxley with gratitude. Whenever we consult his writings, whether in the laboratory, or in the study — we recognise his power, his extraordinary range and accuracy of knowledge, and his charming style : but we must not think of him either as merely a zoologist, or, as merely an essayist, but as a man who most strenuously, and successfully, fought for the supremacy of Science. E. Bay Lankester. July, 1895. [ - ] Report on the Spawning of the Common Sole (Solea vulgaris) in' the Aquarium of the Marine Biological Association's Laboratory at Plymouth, during April and May, 1895, With i^feliminary remarks on some of the morphological conclusions that may he draivn from the study of the early emhryological history of this form. By Gerard W. Butler, B.A. I. Introductoky. From April 3rd to May 17th of this year I occupied a table at the Plymouth Laboratory, to study the embryology of Teleosteans. As some of the fish in the flat-fish tank were known to be spawning, a net was fitted to the overflow channel into the adjoining tank. By the kind permission of the Director I examined this net daily, and, as a rule, a number of times a day, so that I obtained a pretty complete record of the spawning of the fish in this tank during the period mentioned. Four or more species spawned during this period,* but the point most worthy of record is the breeding for the first time in the Plymouth Aquarium, and perhaps for the first time in captivity, of the common sole. * Fertilized eggs of the Plaice {PI. platcssa) 2 mui. iu diameter were obtained on April 2nd, 4th, 7th, ISth, and some of these hatched out in 10-12 days. Eggs about 1'5 mm. in diameter, ai)parently those of the "Jlerrysolo" {PL viicroccjyhalus) were obtained unfertilized on April 19th, and fertilized on the nights of May .0th, 8th, and 10th. Some of these hatched out on the 5th day, the water temperature being 13° C. Smaller eggs, also without oil globule, varying in diameter from '98 mm. to I 15 mm., and thus answering to the unfertilized eggs of the flounder obtained from ditl'erent fish, but possibly including eggs of some other flat-fish besides PL Jlcs-n/i, were obtained repeatedly during April and first half of May, but only one or two fertilized eggs were seen. Attempts to artificially fertilize flounder eggs resulted in nothing beyond the irregular segmentation of some of the eggs. Probably this was due to the only male available not being in i)ro[>er condition. n 2 4 repokt on the spawning of the common sole. 11. Datks and Times of Spawning of the Sole. I obtained uufertilized eggs of the sole on April 3rd and 7th, but on April 12th 1 found fertilized eggs for the first time. Then, again, on April 20th and 2 1st there were only unfertilized eggs. From this time onward, however, fertilized eggs were found during the rest of my stay at the Laboratory, sometimes on two consecutive days, sometimes with one day's, sometimes with two days' interval ; and unfertilized eggs were the exception. Thus fertilized sole eggs were obtained on April 23rd, 25th, 2(3th, 28th, May 1st, 2nd, 4th, 7th, 8th, 10th. Then on May 11th, 12th, and 13th there were only a few eggs each day, of which the majority were unfertilized, and then again a plentiful batch of fertilized eggs on May 16th. The time of day at which spawning occurred seemed to get earlier as the weather got warmer. Thus, during the last week of April, the eggs would be in the first segmentation (two blastomere) stage between 6 and 7 p.m., which, according to subsequent observations, would point to their having been spawned about, or rather before, 4 p.m. ; but later on the egg-laying would begin about noon. On one occasion, when it began about 11.30 a.m., it was not ended before 2 p.m., which is not so surprising, since, as will be explained later, the eggs seem to be shed one at a time. - 111. On the AppeaPvANge of the Ovapies duping the Spawning Season. On May 15th, as it seemed desirable that the state of the ovaries under these known conditions should be studied, it was decided to sacrifice one of the females, of which there were a fair number spawning, and preserve the ovaries for histological study. I first tried whether any ripe eggs were to be obtained from the living fish, but without success ; and on opening the dead fish there seemed to be no quite ripe eggs in the cavity of the ovary tube. This, it may be remembered, was a day on which none of the other fish spawned, though they did on the next day. Judging by the number of fish spawning in the tank and the number of eggs spawned, the number of eggs ripening each day must have been small proportionately to the eggs in the ovary, which is not, of course, surprising, if the spawning is destined to be kept up, on the average every other day, for a period of three months or so. The ova were of all sizes. The largest and most transparent ones, presumably those most nearly ripe, were distributed singly among those less ripe over the whole laminar surface of the ovary, and did not seem to be confined specially to one region of the ovary. However, the third RErORT ON THE SPAWNING OF THE COMMON SOLE. 5 quarter or so of each ovary (reckoning from the head end backwards) was dotted over with small bloodspots, answering to Holt's description of the spent sole.* I presume, therefore, that this region of the ovary was that from which, in the first three weeks or month of the spawning season, the majority of the eggs had been derived. IV. The Act of Spawning. At the time of spawning the soles came to the very front of the tank close to the glass, so that on a number of occasions I had a good view of the process. The soles lay about on the bottom apparently indiscriminately, here one by itself, there two, three, or more near together. One of them would from time to time move leisurely to another place, and in passing by or over one of its companions, would evidently take notice of it, as by feeling it with the under side of its head, but this never led to any- thing of the nature of pairing, such as some have imagined might occur in the case of the sole ; for the fish would again move on and continue the spawning process elsewhere, apparently regardless of the exact position of its fellows, and preoccupied with its own share in the opera- tion. Doubtless, however, such recognitions in passing are the outward sign of the instinct whereby the fish assemble at the spawning time, so that eggs and spermatozoa may rise together in the water, and fertiliza- tion take place. In spawning the sole lay on the bottom of the tank, and raising its head, brought it down again with force. This act involved a certain agitation of the hinder regions of the body also, which was perhaps as important as the more conspicuous movement of the fore part in as- sisting the expulsion of the ova or spermatozoa, but the appearance was as if the fish desired to create a splash of sand by the downward move- ment of its head. The movement was quite different from that by which soles commonly cover their upper side with sand, and had not that effect. The eggs appear to be shed one at a time, each as the result of one of the movements just described. It seemed to me that this movement wafted the egg tailwards ; at least a fresh egg commonly appeared above the tail of a fish after each of the head splashes described. I never actually saw the exit of either ova or spermatozoa from a fish, but if the eggs are shed singly in the manner described, and tlie spermatozoa in correspondingly small numbers, one could, perhaps, hardly expect to ; and I think anyone who saw the eggs slowly rising * E. W\ L. Holt. "North Sea Investigations" (contd.), Journal of Mar. JIM. Jss. of U.K., vol. ii. (N.s.), p. 371. 6 HEPORT ON THE SPAWNING OF THE COMMON SOLE. towards the surface from within an inch or two of the ground, and fresh eggs taking their place to the accompaniment of the movements described, would draw the conclusions that I have. In considering how it is that the fish come to the front of the tank, and will spawn undisturbed while you are just on the other side of the glass, instead of, as one might have expected, retreating to the farther side, one must remember that the fish now spawning have been five years or so in the aquarium, and that thus they are not only more or less tame generally, but have probably come to consider the window border of the tank floor as their place of assembly 'par excellence ; for it is to that side that they are impelled by the common craving of hunger as feeding time approaches, and on that side that they at all sorts of times tend to linger, from that milder motive of curiosity about us strange creatures in the air-tank on the other side of the glass. V. General Eemarks on the Development. On the three occasions on which I tried, I failed to obtain eggs from the living fish, and thus I never witnessed the process of fertilization so as to time the development from the very beginning, as I should have liked. Perhaps I should have succeeded, had I captured the fish as soon as they began to spawn. However, I obtained eggs one hour before the first formation of the protoplasmic disc at the lower side of the egg, and two and a half hours before the first segmentation. The rapid streaming of the protoplasm between the large yolk spheres of the lower part of the egg (which spheres became temporarily transformed into cones pointing downwards), to form the disc, was a very interesting sight. What I saw fully bears out the late George Brook's explanation* of Kuppfer's account of the phenomenon in the herrinff's e> 13 » 14 » • 15 » • 22 NOllTU SEA INVESTIGATIONS. trawlers fishing in the North Sea, the rest coming by railway. It had been stated a few days before, at a conference of the National Sea Fisheries Protection Association, that great numbers of small plaice were being landed at Billingsgate. On the two mornings when I was there, the proportion of small fish was not so large as it had been, and I failed to obtain a box for complete examination. I saw, however, some of the fish landed from a " cutter," or carrier, and the smallest plaice I could see and measure was 6 in. long. This was one of a few lying about the deck, which had fallen from the boxes. I also examined 8 specimens brought to me by Mr. Johnson, of these only two were over 6 in., the rest were below that size, the smallest being 5|in. I could not find out where these fish were caught, except that it was somewhere on the eastern side of the North Sea. I think it will conduce to clearness and precision in considering the data I have given, to keep separate the questions of size and reproduc- tive maturity. To dispose of the latter first, it seems of interest to me, whether it has a practical bearing or not, to try to discover whether immature plaice are found on all grounds, or to what depths and regions they are chiefly confined. I have described samples, 15 fish altogether, from the Great Fisher Bank, and among them were no immature males, and one female apparently immature. The Fisher Bank is from 20 to 40 fathoms in depth. In the large sample of 212 fish from the Leman ground, there were eight females possibly immature, and three possibly immature males. In 13 fish from the home grounds, I am not sure that any were immature, and the same is true of the 19 from the Dogger Bank. Of the sample from Markham's Hole on April 15th, some may have been immature, but it was difficult to be sure. On the other hand, in the plaice from the Sylt ground, there can be no doubt that a large proportion were immature, all females under 9 in. certainly, and a proportion of those above that size, although I am inclined to think, for the reasons given, that some had spawned. I have not examined many plaice from the Humber, but there can be no doubt that in the earlier months of the year nearly all of these are immature. As far as we can judge at present, it would appear that the year-old fish, all of which are immature, are not taken at the season of the year covered by the present observation, in any considerable numbers on any of the off-shore grounds. I consider that the small plaice from the Sylt grounds and from the Humber, consist largely, but not exclusively, in the case of the former, of year-old fish. To consider now length only. The lower limit of plaice from the Fisher Bank was 12^ in. Of the small fish from the Leman ground, which is opposite the Lincolnshire and Norfolk coasts, the lower limit was 7 in. for males, 9 in. for females, and only one fish in a box of NORTH SEA INVESTIGATIONS. 23 212 was under Sin. Of the sample from the home grounds, there were no males under 10 in., no females under 11 in. Of fish from the Dogger Bank and grounds to the south of it, the lower limit was 9 in. for males and 10 in. for females. In the first sample from the Sylt ground, the minimum was 7 in., and there was only one fish out of 55 under Sin. In the second sample, selected from 4 boxes, the minimum was 6 in., and there were 104 fish out of 187 under Sin. At Billingsgate, a considerable numbe'r of the plaice landed were under 6 in. The upper limit is also of some importance, although it is not fully determined by these observations. Of the fish from the Sylt ground none were above 13 in. in length ; in the sample from the Leman ground the upper limit was 14 in., but there were plenty larger than this in the same catch, and in all the other samples there were fish over 14 in. It appears, therefore, that in the period covered by these observations, the usual minimum on the off-shore grounds is 9 in. for males, 10 in. for females, but occasionally it may be as low as 7 in, and 9 in. Fish below these limits have been obtained only from the Sylt ground and the Humber. Parts of the Dogger Bank are quite as shallow as the Sylt ground, where the small plaice are taken, yet such fish are not found there. Proximity to the land, therefore, appears to be an essential condition in the rearing of young plaice. But the question is, why are the small plaice so much more abundant on the Continental than on the English side ? There can be no doubt that the history of the plaice is the same on the two sides. We have sufficient evidence that the plaice hatched from January to March, are to be found abundantly, in summer, along the edge of the shore on the English side, wherever there is sand or sandy mud. Those of a year old, and some of those which are two years old, are the small plaice which are taken to market by the inshore boats in the Humber, and all along the coast of Lincolnshire, Norfolk, Suffolk, and Essex, and by the large trawlers from the Eastern Grounds. But the difference in numbers obtained on the two sides is enormous. On the eastern side a steam trawler brings in between 200 and 300 boxes after about a fortnight's fishing, but I have not heard of a large trawler ever having been able to get a voyage of small plaice on the English side. The cause of the difference seems to me to lie in the confifaira- tion of the sea bottom. There is a rather broad tract, less tlian 20 fathoms deep, extending from England to Holland, from the latitude of the Humber to that of the north coast of Norfolk. But north of this region the 20 fathom line is about 40 miles from the coast of the islands on the Continental side, from 15 to 3 miles on the Englisli side. South of this region also there is a depression deeper than 20 fathoms, which is nearer to the English side tlian to the Continental. It may be true that more of the fioating eggs and larva) of plaice are carried to 24 NORTH SEA INVESTIGATIONS. the Continental side than to the English, but this would make no difference, if food for the young plaice, and other suitable conditions, especially shallow water, were not more abundant and more extensive. We have seen that the food of the small plaice largely consists of Solen, and it is probable that the abundance of this mollusc depends upon wide tracts of shallow sandy ground in the neighbourhood of the mouths of large rivers. A somewhat similar case is that of Lyme Bay, on the south coast of England, where the 20 fathom line is a long way from the shore, and the smaller Brixham trawlers have been in the habit of taking large numbers of small plaice. In Dr. Fulton's investigations, he took a limit of 12 in., and found that plaice under this size were chiefly confined to depths below 10 fathoms, and a distance from shore less than 3 miles. This was on the east coast of Scotland : the 10 fathom line, according to the chart, is in some places 20 miles from the coast of Sylt Island. All this, however, being admitted, it does not afford a reason why the young or small plaice should be less plentiful on the English side, off the coasts of Lincolnshire and Norfolk, where the general slope is nearly as gradual as on the Dutch and German coasts. There is another difference to be taken into account in this locality, namely, as a study of the chart will show, the existence of numerous banks and holes and rough rocky ground. The grounds are worked by trawlers, but are intricate, and necessitate short hauls, while the Eastern Grounds are noted for the slight wear and tear which they cause to the trawl, and the long hauls which can be made on them. It appears probable that the number of young plaice reared is proportional, not merely to the area of ground near the coast below 15 or 20 fathoms, but to the area of ground of a certain quality, and producing certain kinds of fish food ; and a scientific, accurate comparison of the English grounds with the Continental, from this point of view, would doubtless throw much light on the " eastern question " of the North Sea trawl fishery. I hold strongly to the opinion that the business of naturalists in relation to fishery questions is to establish a sound and extensive basis for conclusions on fishery problems, by a thorough study of the physical and biological conditions of the various fishing grounds. With regard to the North Sea, it cannot be maintained that the investigations already made, valuable as they are, supply anything like an exhaustive knowledge of those conditions. On the contrary, they form merely a foundation and preparation for further progress. In March, 189-4, Prof. Dr. Heincke published in the Milthcilungen of the Deutscher Fischereiverein an article on the question of protection of undersized plaice, &c., reviewing at considerable length the report of our Parliamentary Committee on Sea Fisheries, which sat in 1893. NORTH SEA INVESTIGATIONS. 25 In criticising and objecting to Holt's biological limit of 17 inches for plaice, he maintained that the average size of plaice spawning for the first time is much smaller in the German part of the North Sea than in the English. He stated that as the plaice of the Baltic was, at corres- ponding stages, a smaller race than the plaice of the North Sea, so the plaice of the eastern side of the North Sea was smaller than that of the northern and western parts. According to Heincke, the existence of local differences biade not only the same closed areas and the same close seasons for the whole North Sea, but also the same limit of size, impossible. Heincke mentions no observations which support his assertion, but it appears to rest on his own personal experience, and it will be seen, from the observations above recorded by me, that Mr, Holt's figures were probably somewhat too high. My present conclusion is that although there is considerable variation in the size of plaice spawning for the first time, there is no difference between a German plaice and an English, To those engaged in the fish trade, it may be very beneficial to have a limit of size, to exclude the small plaice, because the uncertainty and risk of the business may be thereby diminished, whether any benefit to the fishery is produced or not. This seems to be especially the case at Billingsgate, although it is, to a certain extent, true in other markets. At the former place, I am informed that a considerable proportion of the smallest plaice are worthless, or very nearly so, and the buyer is unable to judge accurately of the value to himself of the box, as it is sold by auction. The fish at the top of the box are of considerable size, and many a poor dealer, I understand, finds great difficulty in retailing his plaice without a loss. It is certain that numbers of the smallest plaice are thrown away, both at Billingsgate and at the various shops, as worthless, and are carted away for manure. There is practically no demand for plaice 5 or 6 inches long, and dealers naturally object to have to buy the goods they require mixed with a (quantity of rubbish which is of no use to them, and often to pay good money for the worthless fish. But all this has little to do with us ; we are only concerned with the possibility of maintaining and increasing the natural supply of the larger plaice. The limit proposed in the bill now before Parliament is 8 inches for plaice. It is clear, from the facts given, that the effect of this, if the law is enforced, will be to exclude the plaice mentioned above — 5 to 8 inches in length. But the question is, how far this exclusion will cause the fisherman to avoid certain grounds. It is very doubtful if throwing the fish overboard will lead to their survival, except, perhaps, in the case of small boats fishing in places like the Humber. On the other hand, there is reason to believe that on the Eastern 26 NORTH SEA INVESTIGATIONS. Grounds the smaller fish are nearer the land, and, to some extent, the existence of a legal limit may have the effect of causing the travs^lers to fish further out, where the larger fish are. I hope to study this question by visiting the grounds on the fishing boats. At present, very little of the remuneration is obtained from plaice under 8 inches, so that the effect of the proposed law is not likely to be any very great protection of the small fish. I have always thought that the question of reproductive maturity is not the question of chief practical im- portance in this matter. To my mind, the question is, can a limit be discovered which will make the small plaice grounds unprofitable, without causing waste on all other grounds. So far as I can see at present, a limit of 10 inches would have conferred considerable protection to the Eastern Grounds, without causing a corresponding or considerable waste on the grounds in the open and central parts of the North Sea. The probable, or we may say the certain, effects of a limit of 8 inches and of 10 inches can be seen, to some extent, by inspection of the data given in vol. ii., p. 347, of this Journal. The box there recorded from Arlberg, Denmark, containing 198 plaice, would not be affected by the limit of 8 inches, while the box from Schierraonnikoog, containing 286 fish, would lose only 9. With a limit of 10 inches, on the other hand, the latter box would lose 200, and the former would lose 97 out of a total of 193. Of the Humber plaice recorded in the same list, a limit of 8 inches would exclude in one sample 224 out of 425 fish, and a limit of 10 inches would shut out all the 425 except 8. In the report on the Dutch Fisheries for 1893, Dr. P. P. C. Hoek has published the results of some experimental trawlings made with a hired trawler off the Dutch coast. The trawl used had a beam of 35 feet in length. The mesh of the net was 2^ inches at the cod end, taking the length of the whole mesh, which presumably means 1-jV inches from knot to knot. The hauls were made between Terschelliu" on the north, and the latitude of Amsterdam on the south, and may be considered in three groups — (1) within 6 miles of the coast; (2) 15 to 30 miles off; (3) about 55 miles off. The following are the sizes and number of plaice taken : First Group of Trawlings. Sept. 15. Less than 3 miles from shore; depth, 7 to 4 fms. About 175 lbs. of plaice, number not given, size 4i in. to 16 in. ; but of the latter only 1 in 50 fish. Sept. 14-15. 5 or 6 miles off; depth, 8 fms. About 43 lbs. plaice, 6i in. to 10 in. NORTH SEA INVESTIGATIONS. 27 Sept. 15. About same distance; 9 fms. A slightly larger number, 7iin. to lOiin. August 30. Depth, 11 fms. About 26 lbs., 6| in. to 121 in. August 31. Depth, 8^ fms. About 175 lbs., 4 in. to lOfin. ; one in 114 fish was 20| in. Sept. 1. Depth, 12 fms. About 9G lbs., 61 in. to 9 J in. For the records given a sample only was measured ; but in all cases a large proportion were under 8 in., and few over 10 in. Second Group of Trawlings. August 24. Depth, 15 to 17 fms. 460 plaice; of 25 measured, 15 Bin. to 8 gin., 10 8 i in. to 91 in. August 28. Depth, 14 fms. 52 lbs., 8 in. to 11} in. August 29-30. Depth, 15 fms. 70 lbs., 8 in. to lllin., and a few up to 14f in. Sept. 5. Depth, 15 fms. 17| lbs., ^m. to llfin. Sept. 5. Depth, 15 fms. 32 lbs., 8f in. to 14 in. Sept. 5-6. Depth, 16 fms. 119 lbs., 8f in. to llfin. Sept. 20-21. Depth, 16 fms. 119 lbs., 5f in. to lOf in. This last haul was about 15 miles from the coast of the island of Terschelling. Third Group of Traivlings. Sept. 11-12. Depth, 17 fms. 35 lbs. smaller, 17Hbs. larger; 8 in. to 14 in., some up to 18f in, Sept. 12. Depth, 17 fms. 24 plaice, 7| in. to 18} in. Sept. 12-13. Depth, 17 fms. 52i lbs., ^ in. to 14f in. The exact proportions below different limits cannot be ascertained, but the above data indicate that a limit of 8 in. would go far to make the ground where the first group were carried out unprofitable. The different sizes on the different grounds are well brought out by the average lengths given. Thus in the first group the averages were : — 6fin., Sfin., S/jyin., 7-^ in., C^-ins., 7f ins. In the second group : — 8^ in., 9i^o in., a little less than 10 in., 9-^ in., 10 in., 9^ in. In the third group : — 11} in., 12 in., 12 in. In Denmark the limit for plaice by law is now 8 in. to tlie root of the tail, or very nearly 10 in., including the tail. In Belgium the limit enforced is 7] in. (18 cm.). In France it is 5'} in., while in Holland the only limit is 3] in. for flounders, and there is no law for plaice. 28 NORTH SEA INVESTIGATIONS. IV. On the Relations of the Generative Organs and of the Sexes in Some Fishes. Althouijli a considerable number of observations have been made and published concerning the sizes of ripe, nearly ripe, and spent fish, and on the condition of the reproductive organs in these various stages, we are far from possessing at present a complete and satisfactory knowledge of the changes through which these organs pass in the development of the fish to maturity, and from one spawning period to the next. This is in fact a subject where investigation re- quires minute microscopic study, and the application of advanced microscopical science ; and the investigation is necessarily an extended one, because it involves a complete examination of all stages in a given fish, and a comparison of all the different fishes with one another. I have a few observations and suggestions to offer here in addi- tion to those contained in my papers on the subject in previous numbers of this Journal. The first point I wish to consider is the remarkable difference in pro- portional size between the ovaries and testes in different species, and in relation to this, the differences between the sexes in number and size. To Dr. Fulton belongs the credit of having first drawn attention to these phenomena, and he has published some important data concerning them, and suggested some explanations. (See his papers in the 8th, 9th, and 10th Eeports of the Scottish Fishery Board). It is well known that in some fishes, as in the herring, the testes or soft roes are as large as the hard, and the same is true of Clupeoids generally. In the cod family it is difficult to judge without accurate weighing, but the testes, which are of a curious frilled shape, quite different from that of the ovaries, do not appear obviously smaller than the latter. In the flat-fishes, on the other hand, the testes are always smaller than the ovaries, and the minimum is reached in the sole, where they are so small as to have been formerly entirely overlooked. Dr. Fulton has given the actual weights of the organs in a number of specimens, but has not worked out the proportion they bear to the weight of the fish. From averages of 10 male herrings and 16 females it was found that in fish of 11"2 in. in length the testes weighed 35'6 grammes, the ovaries 35"0, so that the testes were actually a little heavier. In a male cod 39 in. long the ripe testes weighed 846 grammes, while in a female of 38 in. the ovaries weighed 2,124 gms., or more than twice as much. A difficulty in exact comparison arises from the varying conditions of the organs, whether in the development towards maturity, or whether the discharge of products after spawning has commenced ; all that can be done is to compare them just before the commencement of spawning. NORTH SEA. INVESTIGATIONS. 29 In a male plaice 21 in. long the testes weighed 29"5grms. ; in a female 23| ins. the ovaries weighed 503 grms. In the lunipsucker, in a male 12 in. long the testes weighed 70'8 grms., in a female 17 in. long the ovaries weii^hed 878 crrms. If the small size of the testes were compensated by the greater abundance of the males, an approach to equality in the quantity of the generative products might be the result. But the opposite of this, according to Dr. Fulton's researches, is usually the case. Thus in the cod there were found to be 133 females to 100 males, in the plaice 142 females to 100 males, but in the lumpsucker there were only 25 females to 100 males, and in the herring the numbers of the two sexes were very nearly equal. Dr. Fulton considers the probable significance of these relations, and concludes that the testes are usually smaller in fish with pelagic ova, and more nearly equal in those with adhesive ova, and he thinks the explanation is that fertilisation is more certain in the case of pelagic ova, because the sperms move upwards like the eggs, while in the case of attached ova a great deal of the milt is wasted. There is probably much truth in this suggestion, but I would put it in a somewhat different way. In the sea the water is generally moving in one direction or another, and the milt shed into the water disperses by diffusion, even without the movement of a current. Therefore, if the eggs are fixed, much of the milt must travel away from them, and more of it is required. Where the eggs are free in the water like the milt, they scatter together, and are moved together by the currents. It is remarkable, however, that in the angler, of which the eggs, though free in the water, remain connected in a continuous sheet, the males are much more numerous (100 males to 26 females), and the males are also larger, though whether the testes are larger than the ovaries has not been ascertained. But the proportion in bulk between testes and ovaries differs very greatly among fishes which agree in having pelagic ova. For instance, in the cod the inferiority of the testes is very much less than in the plaice, and in the plaice than in the sole, while in the flounder, although the testes are smaller, the males are more numerous than the females. It seems to me that these differences are to be explained by the differences in the rate of spawning. Some fishes, like the herring, shod the whole crop of eggs for the season at once. The eggs are all in the same stage of development, and therefore are all ripe at one time, and when spawning begins it continues at a rapid rate until the roe is empty, and the fish is spent. Plaice and cod do not spawn so rapidly as this, but it is certain that in both these fishes a large number of eggs can be squeezed from a ripe female at one time, so that the roe is soon emptied. The rate of spawning, and its duration, can be studied by 30 NORTH SEA INVESTIGATIONS. examining the ripe and ripening ovaries, as Dr. Fulton has done to a great extent in his investigation of the fecundity of fishes. In some cases, although the number of ripe eggs present is considerable, there are others in various degrees of development, so that spawning is prolonged. This is the case in the gurnard, and in some lishes with attached ova, such as Syngnathus acus, Anarrhichas lujms (the cat fish) and others. In the plaice, according to my own experience, and Dr. Fulton's observations, a large number of ripe ova are shed at once, and the season's crop is soon exhausted. There is no prolonged production of young ova to succeed those ilrst shed. The lish being of a high degree of fecundity, and having all its eggs nearly ripe at once, the distension of the body by the ripe ovaries is very great. In accordance with this state of things the testes are rather large, very much larger than in the sole, and spent fish appear early in the spawning season. The spawning process being thus completely and abruptly terminated, the ovary reverts to a resting condition. At Plymouth I found a spent specimen as early as January 28th, at Grimsby the first I recognised was obtained on February 27th. The conclusion that the ovary does revert to its original condition, based on the evidence given in my paper on the ovaries of fishes, vol. iii., p. 154, has been confirmed by my observations this season at Grimsby. It has been shown in former papers by ]\Ir. Holt and myself, that in the spent ovary the chief peculiarity is not the appearance of empty follicles from which ripe eggs have escaped, but the presence of partially yolked eggs, which are found to be afterwards absorbed. But the opaque granular masses to which I have so often referred above, had not attracted my notice very much before the present season. They are easily overlooked, not because there is any difficulty in seeing them, but because they are so indefinite in shape, and do not appear at first to have any important significance. The history of the ovary could be worked out with more certainty if we were able to examine specimens in captivity, the date of whose spawning was known from actual observation. I have in a former paper described a few such specimens, but they were not killed until several months after spawning. I have not yet made a thorough examination of shotten herring, but the few notes I have made tend to show that in the spent ovary the ova are all quite yolkless and transparent, as in the immature ovary. A newly-spent herring can be recognised from the llaccid and congested condition of the ovary, but it is extremely probable that this condition soon passes away. The haddock presents a condition similar to that of the plaice, that is to say the spawning of an individual fish is soon over, the development of the eggs being nearly simultaneous. On April 20th I examined NOETH SEA INVESTIGATIONS. 31 6 specimens in which the condition of the reproductive organs was as follows : — Length of fish 14 4 in. Testis a thin translucent cord : fish apparently immature. Length 15 in. Female, ovary small, I5 in. long, no yolk, no granular masses : apparently immature. Length 17f in. Female, ovary spent, Ij^in. long, much mucus in cavity. In the germinal tissue yolkless eggs and dead partially yolked eggs as in spent plaice, but the latter were few and scattered. Length 19|in. Female, ovary 2g in., spent. Same condition as in preceding. Length 20 Hn. Female, spent ; same condition. Length 20i-in. Male, spent, testis almost invisible. There can be little doubt here about the rapid recovery of the ovary, and the danger of confusing immature with recovered fish. On the other hand, in the lemon dab and common sole, the spawning process in a single female is gradual and prolonged, and spent females do not appear early in the spawning season. When a ripe ovary of these two species is examined, the eggs are not found to be nearly uniform in development, but to form a graduated series down to the minute. In spite of this similarity I have observed that a large number of ripe eggs can be obtained at one time from a lemon dab, and the testes are of considerable size, but still, according to Dr. Fulton's figures, smaller in proportion to the ovaries than in the plaice. The witch appears to resemble the plaice, the eggs developing uniformly, and the testes being rather large. I have examined a few witches at Cleethorpes. The size of mature and immature specimens has not been so carefully studied in this species as in others. On February 18th I examined 6 specimens. Two were males, both mature, 15^ and 16 J- in. long; four were females, 16i to 18jin, and all mature, but not ripe; that is to say, the ovaries were enlarged, and the development of the yolk in the eggs advanced. On February 23rd I examined 4 more, all females, 15 in. to 19Mn. long, and all mature. Mr. Holt found some lemon dabs immature at 12 in., and 50 per cent, of the females at 11 in. At Plymouth I examined numbers of females down to 7 in. long, and none were immature. My observations were made from January to March, Mr. Holt's between February and September. On February 18th last I examined G specimens : 2 were mature males, 12| and 12o in. long, 3 were mature females, 12^ to ISf in. ; and one 9y in. was an immature female. There could be no doubt about the last specimen, as no spent females were to be found at that date. 32 NORTH SEA INVESTIGATIONS. In all the fish hitherto mentioned there are no oil globules in the ripe egg, and the develoitment of the yolk follows the course which I have described in my two papers, vol iii. pp. 154 and 2.58. In all these cases I have satisfied myself that the development of the yolk in the eggs takes less than a year. In other words the formation of the crop of eggs for the next spawning season does not begin until some time, about three or four months, after the preceding spawning. But in my paper, vol. iii, no. 2, I described in the egg of the sole the presence of minute globules in the ova of immature females during the spawning season, and in spent females. Recent observations have shown me that these minute globules occur only in those eggs in which oil globules are present in the ripe condition, and I conclude that the deposit of oily matter commences in the ova long before that of yolk proper. On April 8th I examined 3 small brill, procured from a lot of 34, brought with 4 small turbots and 120 boxes of small plaice from the Sylt Grounds. One was 9} in. long, a male not ripe, but with testes rather large and soft, evidently approaching ripeness. One was 11^ in., a ripe male. One was Hi in., a female, the end of the ovary 4] in. from the anterior end, 4^ from the posterior end of the ventral fin. All the ova under the microscope were transparent, but except in the very smallest there were small, clear globules, principally collected round the germinal vesicle. I think this specimen could not have matured its eggs during the present spawning season, and would not have been ripe for at least 12 months. On April 22nd I examined another specimen, 15 in. long, in which the left ovary was 3^- in. long and 5 in. from the end of the ventral fin. There was nothing to indicate that this specimen was spent, all the ova were transparent, but here and there one showed the scattered globules I have mentioned. This specimen was presumably immature. On April 24th I examined the ovaries of two turbot. One was 19f in. long. The roe was opaque white from the development of yolk, and obviously approaching maturity. Under the microscope the yolk in the eggs was in all stages of development. In some there were only the peculiar globules I have mentioned, in others a little larger, these were more numerous, and began to form a dark zone round the germinal vesicle, while in the outer part of the egg were globules of ordinary yolk of a much lighter appearance. In all the eggs in which the development of yolk was considerable, there was an inner darker and an outer lighter zone. The other specimen was 15\ in. long, and the formation of the dark inner zone had commenced in an egg here and there. Apparently this specimen would have spawned this season. NORTH SEA INVESTIGATIONS. 33 On April 26th I examined a number of Trigla giirnardus. I did not note the sizes of these, but all were mature, and in most of them there were some ripe eggs. In each ovary there was every stage of develop- ment, from the transparent egg with a few globules to the large also transparent ripe egg, with its large single copper-coloured oil globules. As in the turbot, what may be called the second stage consisted in the formation of a dark inner zone round the germinal vesicle, with scattered globules in 'the outer region. In the next stage the egg is full of yolk, no clear protoplasm is visible, but there is a marked con- trast between the dark inner zone and the light outer. In the fourth stage the contrast is less marked : the dark inner zone appears to consist of very minute globules of oil, and at this stage they run together and form large globules, in consequence of which the inner zone becomes more translucent. In the fifth stage the coalescence of the inner globules and of the outer into larger and larger drops can easily be seen, and it is perfectly obvious that the inner drops form the oil globule of the ripe egg. Thus the oil globule originates in the central part of the egg, and only rises to the surface when the whole yolk becomes a continuous liquid. These facts considerably modify the criticism I have given in vol. iii. p. 2G3, of Scharff's account of the development of the egg. I have not his paper here to refer to, but he worked with the eggs of Trigla gitrnardus, and described the division of the protoplasm of the egg into two layers. In the eggs of plaice and flounder I could only find an outer yolk layer and an inner without yolk. I have now shown that there are at any rate two types in the development of yolk in the eggs, one characterising the eggs without oil globules, the other those that possess the latter. In the ovaries of fish whose eggs possess oil globules, the presence of minute scattered globules, in otherwise protoplasmic eggs, does not imply the " active " condition of the ovary — does not, that is to say, prove that the maturation of the ovary for the next spawning season has commenced. It seems to me quite possible that in these fish also a spent ovary may revert to the condition of the immature, but on this point we have at present little or no evidence. The dark inner zone in the developing eggs above described appears to be due to the presence of exceedingly minute and numerous globules of oily matter, which by their great sub-division and refracting power cause the opacity of that part of the egg. V. Two Trips to the Eastern Grounds. Ill order to acquaint myself, by personal examination, with the condition of the Eastern Grounds, and the products of the trawling New SERIF..S.— Vol. IV., No. 1. D 34 NORTH SEA INVESTIGATIONS. there carried on, I liave made two trips on board steam trawlers bound to those grounds. On my first voyage, I left Grimsby Docks on May 14th, on board the s.s. Lucania, belonging to the Alliance Company. Tlie run was about 260 miles E. \ N. When we reached the neigh- bourhood of the Horn Reef on the 15th, it came on to blow, and we lay-to for twenty-four hours without shooting the trawl. This was the commencement of the disastrous gale, which continued, with little inter- ruption, on the English side of the North Sea, until Monday, ]\Iay 20th, but on the German, or eastern side, it moderated on Thursday evening, and for the rest of the trip we had very fine weather. The trawl was first shot on the evening of May 16th, and hauled at 11 p.m., but I did not make any observations until the second haul, at 6 a.m. on the 17th. Tlie position, then, according to the captain, was thirty miles south of the Horn Eeef, twenty miles west of the Sylt. The marketable fish taken were haddock, cod, and plaice. Of the last, the smallest was 12| in. long. Tlie refuse consisted of whelk spawn and crabs (Hyas arancus and Cancer imgurus). Tlie bottom was sand and broken shells ; there were pieces of shell on the net. During the third haul the depth was 11 to 13 fathoms, and the bottom consisted of coarse sand, called rice-ground by the captain. A tow net was put on the trawl head, and the tin at the end of it came up half full of tliis sand, in which were three living specimens of Amjjhiooms. The fish caught were 2 baskets of plaice, none under 12 in., 14 baskets of haddock (9 of kit and 5 of gibbers), 23 cod, 2 turbot 1 brill; none of the turbot or brill under 12 in. The stomachs of the plaice contained Solen. The fourth haul, lasting like the preceding six hours, was concluded at 8 p.m. on the 17th. A net of mosquito-netting on the trawl head, brought up a number of larval flat-fishes in process of transformation, probably plaice and dabs, and also one sand-eel. The fish in the trawl were 14 baskets of haddocks (10 of kit and 4 of gibbers), several cod, 3^ baskets of plaice, the smallest of these being 11^ in. by measurement. There were 2 lemon soles, one of them 8f in. long. A large number of dabs were obtained in this and all other hauls, but were not saved for the market, their value, after being iced for some days, not being considered sufficiently great. A few of tlie largest were cleaned for the cabin table, the rest thrown overboard. The haddocks' stomachs contained brittle stars ; these, and all other marketable fish, were gutted before being packed away in the fish hold. Edible crabs occurred in every haul, but were not saved for market, only a few being eaten on board. At the fifth haul, at 3 a.m. on May 18th, were taken 22 baskets of haddock (7 of gibbers and 15 of kit), and 2 of plaice. A larger number of haddock arc usually taken at night than in the day-time. NORTH SEA INVESTIGATIONS, 35 At the sixth haul, at 10.30 a.m., the catch comprised 8 baskets of haddock, 3 of plaice, 1 turbot, 1 hake, 5 codling, a few whitiug, numbers of dabs, and 1 gurnard. The smallest plaice was lOf in. long. Seventh haul, 5 p.m., IMay 18th. 9 baskets of haddock, viz., 3 of gibbers, 6 of kit, 2 baskets of plaice. 1 turbot, 28 i in. long, a female, nearly ripe; 1 brill, 13^- in. long, approaching ripeness. The food of the plaice was, as usual, Solen. During the eighth haul the vessel was steered first N.N.E., and then S.S.W., the depth was 13 fathoms and the Inner Horn Eeef light was seen, bearing E. by N., distant about ten miles. I could not obtain the exact position for every haul, but it must be understood that trawling was carried on without interruption, so that one or two fixed points are enough to indicate the fishing ground. A steamer carries two trawls, one on each quarter, and as soon as one was hauled, the other was shot. As we were keeping in the same neighbourhood, the vessel was steered on one course for about three hours, and then on the opposite course for the remaining three. It may be pointed out, that the principal part of the catch in these hauls was the haddock. At the eighth — a ni"ht haul — there were 8 baskets of gibbed haddock and 20 of kit, and only 2 baskets of plaice. Ninth haul, 8 a.m., May 19th. The foot-rope was broken and the net torn, an indication of rough ground. The marketable fish were, 8 baskets of gibbers, 16 of kit, 2 of plaice, 4 brill, 2 turbot, about 20 cod, 1 halibut. The kit haddocks measured about 15 in. long, the gibbers 20 to 26 in. The smallest plaice was 12h in. long, the largest 26 in. Of the brill — 2, 13 in. and 14i in. respectively, were immature females ; 2, 14 in. and 16^ in. in length, were ripening. Of the turbot — 1, 13| in., was an immature female ; the other, 14 in., a mature male. The smallest cod was 13 in. long, the rest were about 3 ft. — some more, some less. The stomach of one large cod contained 4 sand-eels and 2 crabs (Inachns) ; another contained 12 sand-eels ; another a large crab (Hyas). The halibut was 4 ft. 8 in. long, a spent female, and had 10 haddocks in its stomach. Tenth haul, 6 p.m. ; depth, 13 fathoms. The trawl was down nine hours this time, the day being Sunday. There was in the net 1 mackerel — a ripe male ; 3 hake — 2 males, 1 female, mature, but not ripe ; 7 large turbot, female, mature, but not ripe ; 1 brill, over 12 in. ; 1 sprat, a ripe female ; 4 baskets of kit haddock, l basket gibbers ; 2 baskets of plaice. In the stomach of one of the turbot were 3 sprats and 2 sand-eels. A few large mackerel were also got at the eleventh haul. Twelfth haul, 8 a.m.. May 20th. During this haul, at 2 a.m., the Outer Horn Eeef Light was seen, bearing N.E. by N., and distant about 10 miles. The net brought up 9 baskets of kit haddock, 2 of gibbers, ]) 2 86 NORTH SEA INVESTIGATIONS. 3 of plaice, 1 of gurnard (Trigla gurnardus), 2 turbot, one 14 in. long, a mature male, one 24 in., a mature female ; 25 large cod, and some small. As usual, there were no small plaice, but many large, 20 in. long and upwards. Thirteenth haul, 5 p.m. The depth of 1;" fathoms was obtained by the lead. There were 7 turbot — 2 mature females, 29^ in. long, 5 mature males, 14^ to 21 Hn.; 2 brill, 17i in. and 20 in., both mature females. Also 10 baskets of kit haddock, 3 of gibbers, 3 of plaice, and 1 of gurnards. About half a basketful of small haddocks, about 10 in. long, were shovelled overboard with the dabs. The smallest of these were 6i in. long, but there were few as small as this. The smallest dab was 5 in., an immature female, but nearly all of them were mature and spawning, many being nearly spent. Sixteenth haul, 4.30 p.m., May 21st. There were 3^ baskets of kit haddock, 1 of gibbers, 3i of plaice, li of gurnards, a few codling and rokcr. The plaice were nearly all large, none under 12 in. There was 1 brill, 12^ in., an immature female ; no turbot. 1 Acanthias vulgaris and 1 Echinus were taken. At 6.30 p.m. we were steering E. by N., the depth 13 fathoms, bottom fine sand. "VVe saw the Outer Horn Eeef Light after dark. Eighteenth haul, 5 a.m., May 22nd. There were 2 turbot, 25f in. and 27| in., both mature females ; 3 brill, 15|- to 18| in., all mature females ; 1 basket of large plaice, none under 12 in., about a basketful of haddock and one of gurnard. In the last, or nineteenth haul, there were 2 soles, one 7i in. long, a male, immature, one 11^ in., a male, mature. A few other soles were taken during the voyage, but never more than 2 or 3 in one haul. Ptoker, i.e., Ilaia clavata, and other species, were also taken, but I paid no particular attention to them. The most important points noticed in this voyage are the following : — No small plaice were thrown overboard, because none were taken of so small a size as to be unmarketable. None of those taken were less than 10|in. long, and a large proportion were 20 in. and upwards. The captain said that when we were in sight of the Inner Horn licef Light, we were on the same ground on which he obtained chiefly small plaice in the previous March. Whatever the significance of that fact may be, supposing it to be correct — and I have no reason to doubt it — it is certain that the small plaice were not there in May. Only two or three lemon soles and an insignificant number of soles were taken. A few immature turbot and brill were observed, but none were under 12 in. in length. The only fish thrown overboard were the dabs, a comparatively small number of small haddock, and some small gurnard and whiting. NOETH SEA INVESTIGATIONS. 37 After my return from this voyage, I noticed in the market that the catches from the Eastern Grounds often inckided larsje numbers of small brill and turbot, and a considerable quantity of soles. Thus, on May 30th, a vessel which had been fishing 10 miles off the Sylt Light, at about 13 fathoms, lauded about 200 boxes of small plaice, 3 boxes of soles, 130 small brill, and 28 small turbot. By small here, I mean brill and turbot about 12 in. in length, very few of these fish exceeding 14 in. I bought a 'sample of the brill for examination, not selecting them in any way There were 20 in the sample — 3 males, 17 females. The smallest female was lOf in., the largest 12| in., and all were immature. On examination of the ovarian tissue with the microscope, a few of the eggs, in nearly all the specimens, were found to contain the scattered central globules, which I have mentioned elsewhere, as occurring in immature brill and turbot. The three males were from 10} to Hi in. in length ; the smallest was sexually ripe, the other two nearly, but not quite so. On June 1st I bought a box of small plaice, brought from the ground off the Sylt. The price of this was 3s. 9d. It contained 3G0 lish — 211 males, 149 females. It is of importance to note that the males were the more numerous, although it is known that the females are more numerous in plaice on the whole. The smallest male was 7f in. long, the largest Hi in. There were 3 males under 8 in., 131 under 10 in. The smallest female was 7f in., the largest 13 in. There were 4 females under 8 in., 8G under 10 in. The total number in the box under 8 in. was 7 ; the total number under 10 in. 217, or GO per cent. I examined the roes of a few of the females microscopically, with the following results : — Plaice 7f in. long. Ova all yolkless ; no opaque masses. 81 SI ^ 8^ 9 9g 91 H 10 11 12i A few opaque masses, or dead yolked eggs. No yolk, no opaque masses. No yolk, a few distinct granular masses. Granular masses distinct. Granular masses distinct, but small. No yolk, no masses. 13 On Monday, June 3rd, I examined in the market the fish landed from a steam trawler, which had been fishing about 21 miles off the 38 NOKTII SEA INVESTIGATIONS. Amrum Light, i.e., to the north of Heligoland, and was struck with the very large number of small brill and turbot in her "voyage." I found, by actual count, that she had 64G small brill and 150 small turbot. Many of these brill were under 12 in. and many of the turbot. There were also 2G larger brill, and 10 larger turbot, the largest of the former being 20 in. long, of the latter, 28 in. The rest of the catch included Gl boxes of medium plaice, 100 boxes of small and 7 boxes of soles. The last were by no means undersized. On this same vessel I went to sea the next day, to make observations during her fishing. We steered E. \ S. from the Newsand Lightship. The trawl was first shot a little before twelve (midnight), on June 5th. The position was about IS or 20 miles west of the Sylt; the depth 13 to 14 fathoms. First haul, G a.m., June Gth. The marketable fish were : 5 baskets of kit haddock, 2 baskets of plaice, none small, 4 cod, rather small, 2 coal fish, 6 turbot. Three of the turbot were females, 2 of them 29^, 31| in. ripe, 1, 21i in., 2 others were mature males loi in. to 20 in. The largest turbot yielded ripe eggs freely, and was nearly spent after I had squeezed it : this shows that the turbot, like the plaice, sheds a large number of eggs at once, especially towards the end of the spawning process. The refuse thrown overboard consisted of small haddocks, dabs, gurnards and whiting. There were also half a basketful of common whelks; Cancer pa/ju7'us,Taianj; whelk spawn, quantities; Asterias ruhens, many; Solaster 2'>cipposus, many; Alcyoniuin digitatum, quantities. Second haul, 11.30 a.m. At the beginning of this shot we towed S.E. i E., depth 12 J fathoms. Just before hauling we got 11 fathoms. When the fish were on the deck I saw that we were now on the small plaice grounds. The plaice kept for market were sorted by the crew into two classes, according to their size, and the smallest were thrown overboard. I found that the smallest saved was 11 in. long, the smallest in the whole catch was Gi in. long. After the valuable fish had been picked up the rest were left for me to examine : I found there were about two baskets of plaice, the largest being 10 in. long ; all these were shovelled overboard, with a few small haddocks and numbers of small dabs. The fish kept were : — 1| baskets large or medium plaice. 1| „ small plaice. 2 „ haddock, i „ dabs. 18 pair of soles, none under Sin. 1 coal fish, 1 Trir/la hirunclo. 5 turbot, 11 J, in., l."Iin., 14 in., 14 in., lOMn. 3 brill, 11 in., 13 in., 13 in. NOKTII SEA INVESTIGATIONS. 39 It is evident that the plaice thrown overboard by the captain of this vessel would have been all taken to market by many captains, because I have seen numbers of plaice from 6 to 10 in., in the market at Grimsby. Third haul, 5.30 p.m. During this shot the vessel was steered first to the S. and we passed near the Amrum Bank, sounding 8 fathoms, coarse sand ; then we steered to the W.S.W. As soon as the other trawl was shot, the nien began picking out and gutting the fish, shovelling over the worthless fish as they proceeded, to get them out of the way. Some of the small plaice and dabs first thrown over were, therefore, alive : whiting and grey gurnard were also rejected. The fish kept 1 baskets medium plaice. 3^ „ small „ 1 „ haddocks. 1 „ cod and dabs. 32 pair of soles. The smallest plaice kept was 10 in. long : many of those thrown over- board were over 8 in. In reckoning the number of soles, only the larger are counted as pairs, a good many smaller, called slips, not being counted, although taken to market. There were also 28 brill, the largest of which was 17 in. long. I measured and examined these carefully. 21 of them were immature females, the smallest being 11 in. long. Leaving out fractions of an inch, 5 of these were 11 in. long; 9, 12 in.; 5, 13 in.; and 2, 14 in. Two were mature females, loHn. and 17 in. respectively. The remaining 5- were males, all immature, though they would probably have become ripe later in the season : 4 of them were 11 in. long, one 12 in. In examining brill and turbot on board ship, I have put down all females as immature which had no yolk in the roe, judging that they would not have spawned this season, wliile those in which the roes were in process of maturation I have called mature, though many of them had not begun to spawn, and probably had never spawned in their lives when caught. Of these 28 brill then, 9 were under 12 in., and 21 females and 5 males were immature. The turbot were 5 in number, 3 of them immature females, 2 mature males. The females were 11^, 12| and 14in. long, the males 11| and loin. long. There were also taken 2 specimens of Trujla hirundo, known to the Grimsby fishermen as latchets, to the Plymouth men as tubs ; these were large mature fish ; and 1 lemon sole 8 'I in. long. Fourth haul, 11. ."Hi p.m. During this haul the vessel was steered somewhat away from the coast into deeper water, namely, 12 to 13 fathoms. It being dark when the trawl came up, T could not examine the fish very completely. As in other similar cases, I contented myself 40 NOKTII SEA INVESTIGATIONS. with making a note of the fish saved according to the information given me by the mate : they were : — 9 baskets of haddocks. 1 „ „ medium phxice. I score cod. II pair of soles. 1 turbot, 2 small brill. 2 latchets. Small plaice occurred in insignificant numbers. Fifth haul, 6. a.m., June 7th. Soon after the trawl was shot, at 12.25 a.m., the Amrum Light was seen just on the horizon, about 20 miles distant. The vessel was steered towards the land, and just before hauling we sounded 10 fatlioms, near the edge of the Amrum Bank. The fish of this haul were also not completely examined by me ; there were saved : — 3 baskets medium plaice. 5^ „ haddock. 18 pair of soles. Nearly a basket of turbot and brill, some small. 3 large cod, some latchets. Very few small plaice. Sixth haul, 9 a.m. The trawl was hauled up after being down about two hours, in consequence of an accident in putting over the buoy. The captain gave orders to put out the usual buoyed flag-staff to mark this ground, where the fish was fairly plentiful, and when the anchor and line belonging to the apparatus were thrown overboard they were caught by the trawl, and it became necessary to haul. The largest plaice was 15 in. long, the smallest 8^ in. There were 11 turbot and 15 brill, 3 turbot and 1 brill being under 12 in. Of latchets, 11 were taken; one I opened was a female approaching ripe- ness, with about 6 sand-eels in the stomach. The latchets were not considered very valuable fish : none were thrown overboard, but a considerable number were eaten on board : the other fish taken for cooking were dabs, whiting, and roker, and occasionally small plaice. The fish thrown overboard from this haul were plaice up to 11 in., dabs up to Hi in., and also some grey gurnard and whiting. The other fish 3 baskets small plaice. 2 „ medium plaice. 1 „ codling and dabs. ■o i ,, gibbed haddock. o n „ kit NOKTII SEA INVESTIGATIONS. 41 Seventh haul, 2 p.m. The depth where the buoy was put down was 12 fathoms. In this haul there were 4 turbot and 6 brill under 12 in., out of a total of 18 turbot and 24 brill: this is nearly 25 per cent. One brill, about 8 in. long, was thrown overboard dead. There were 18 pair of soles, none under 8 in., few, if any, under 10 in. There were 8 latchets. Of the rejected fish the plaice were 7j to 10 in., the haddock about Hi in., the whiting about 13 in., and a number of grey gurnard were also thrown over the side. There were saved : — 2 baskets of small plaice. 2 „ medium „ 12 to 15 in. long. 2 „ haddock. I „ codling and dabs, 1 large cod. It is difficult to estimate exactly the number, or quantity, of small plaice thrown overboard from this haul, but roughly, there were about 2 basketfuls, besides the dabs, gurnards, small haddock and whiting. When the trawl came up, I was called to see a small sole, caught in a crevice of the ground rope. It proved to be a Solca liitca. I did not see a sole less than 9 or 10 in. in length all the voyage and believe that, if caught at all, they escape through the meshes. Several of the smaller that are caught are nearly through the meshes when the net is hauled and are dragged through by the men, by hand, as the net comes up. Eighth haul. Trawl up at 8 p.m., after fishing round the buoy. There were 90 turbot and brill, all rather small, but I only noted 2 turbot and 3 brill under 12 in. Of plaice, the smallest in the haul was 7i in. long ; 2 baskets of the medium size were saved, they were from 12| to IS.Hn. long; also 2 baskets of small, 10 in. to 12i in. About 3 basketfuls were thrown overboard. There were 30 pairs of soles, the smallest Hi in. long. As usual, there were some latchets, and 1 Acanthias vulgaris was taken. 2 baskets of haddock were saved. Ninth haul, 2 a.m., June 8th. At the commencement of this haul, the Amrum Light was seen on the horizon, bearing E. by N. and distant about 20 miles ; this gives, with sufficient accuracy, the position of the fishing ground. A lantern was attached to the top of the buoyed llag- staff, at dusk, the previous evening. The fish saved were : — 3 baskets medium plaice. 5 „ small. 2 „ gibbed haddock. 4 „ kit 58 pair soles. 70 turbot and brill. 12 latchets, 2 cod, 10 codling. A basket dabs. 42 NOKTII SEA INVESTIGATIONS. Tentli haul, 8 a.m., June 8th. There were very few small plaice this haul and few brill, but turbot and haddock were plentiful ; soles were also scarce. The vessel had been further to the westward, although the depth, namely, 10 to 12 fatlioms, had not been much greater. I made a careful examination of the turbot. There was one ripe female, 24 in. long and several ripe males. I fertilised the spawn from this specimen and threw it overboard, that it might not be wasted, as the only bottle available already contained fertilised turbot spawn. There were 9 immature females, the smallest 13^ in., the largest loHn., and 1 female approaching maturity, 14| in. long; 12 mature males, the smallest 13 in., the largest 10 in. long. There were 7 brill, rather small. The rest of the fish saved were : — 2 baskets gibbed haddock. H „ kit 2 „ medium plaice I „ small „ 10^ to 12 in. II pair of soles. 14 large latchets, 2 or 3 smalL 1 basket of cod. Eleventh haul, 2.30 p.m., June 8th. This haul we again got more brill, soles and small plaice, and fewer haddock, having steered towards the land again. 3 small plaice, put into a tub of clean water after the men began to gut the fish, lived vigorously for some time, until they were thrown overboard. Many of the small plaice were alive when the first shovelfuls were thrown over. The smallest of them was 6^ in. long and there were numbers 7 in. ; one of the latter measured 2i in. across the broadest part of the body, excluding the fins. The mesh at the cod end of the trawl is nearly 3 in. in length when elongated and it seems strange that plaice of this size do not escape. The reason is that the skeleton is rigid, and the strong anal spine acts as an obstacle ; the young plaice, too, has no instinct towards working its way through an aperture as the sole has, and none of the required agility — its only instinctive movement, when disturbed, is to Hap its body up and down. The smallest fish in the haul was a dab 41 in. long, an immature female. There were 47 turbot and brill — of these, 5 turbot, and 9 brill, were under 12 in. The smallest turbot was 8i in. long, and its stomach contained 2 sand eels, and 2 small dabs. I examined a sample of the refuse : it contained 27 plaice under 8 in., and 40 over that limit. The rest of the fish saved were : — 4 baskets medium plaice. 6 „ small „ i „ gibbed haddock. U „ kit I „ whiting. 32 pair of soles, the smallest 10^1 in. ; none thrown overboard. NORTH SEA INVESTIGATIONS. 43 Twelfth haul, 8.30 p.m., June 8th. At 7.45 p.m. we sighted the island of Heligoland and then turned round and steered north. We lost the buoy, the day having been very foggy, and were unable to find it again. A large specimen of the tope, Galcus vulgaris, was caught in this haul ; it was a male and measured 3 ft. 8| in. The fish saved were : — 5 baskets of small plaice. 3 „ medium „ 2 , „ kit haddock. 1 „ gibbed „ \ „ soles. 24 turbot and brill, rather small. A quantity of small plaice and dabs thrown over. Thirteenth haul, 2 a.m., June 9th. At 9.30 p.m., at the commence- ment of this haul, the Amrum Light was seen, bearing E. by N., and Heligoland Light, bearing S. by W. I was not on deck when the fish were sorted, but some of the smallest were saved for me ; they were G plaice, 5 in. to 6^ in. in length ; 21 dabs, 2 of them 2^ in. long, the rest 3 1 in. to 6| in. The fish kept for market were : — 7 baskets small plaice. 3 „ medium „ 1 „ gibbed haddock. 3 „ kit 50 pair soles. 21 turbot and brill. 1 latchet, 1 cod. Fourteenth haul, 8.30 a.m., June 9th. We steered in to the eastward, to see if there were more soles to be got nearer the land and at 8 a.m. sounded 9^ fathoms. At this time there were five steam trawlers in sight, one smack, and six German sailing vessels of small size, of a kind called " snibs " by the Grimsby fishermen. There were 60 turbot and brill altogether this haul. I examined 19 brill and 5 turbot. Of the brill, 11 were immature females, the smallest 11^ in., the largest 13^ in. in length. The other 8 were males, the smallest lOf in., the largest 17i- in. long, and all mature except one at 11| in., which would probably have become ripe this season. Of the whole 19, 5 were under 12 in. — 4 males and 1 female. Of the turbot, 1 at 31f in. was a spent female, 1 at 20 1 in. was a mature but not ripe female, 1 at 12| in. was an immature female and 2, 12^ in. and 14 in., were mature males. The rest of the fish kept for market were : — 2^ baskets medium plaice, 12^ in. to IG in. 5 „ small plaice, 9| in. to 12^ in. 1 basket kit haddock. I „ gibbed haddock. i „ codling and dabs. 3 large cod. 30 pair of soles. 44 NOllTU SEA INVESTIGATIONS. The soles in this and other hauls were ripe and spawning. As usual, a lot of small plaice, gurnard, and dabs were thrown overboard. The soles were more plentiful than was usual for a day haul. Fifteenth haul, 12.30 p.m., June 9th. Just before this haul we sounded 10|l fathoms. The fish kept were : — 2 baskets of small plaice. li „ medium plaice. li „ haddock. ^ basket of dabs. I „ whiting. 20 pair of soles. 34 turbot and brill, many under 12 in. About 12 latchets. The smallest brill was 9^ in. long. The smallest dab saved was 9} in. long. I was told that the last time the vessel sold her fish the dabs fetched 10s. a box, which is more than the usual price of small plaice. Whiting were saved for the first time this haul, as they do not keep well for many days in the fish-hold. I examined half a basketful of the stuff thrown overboard. It 101 male plaice, smallest Q} in., largest 10;^ in. 46 female plaice, smallest G^ in., largest 9| in. 18 male dabs, Qh in. to 9h in. 17 female dabs, 5f in. to 9 in. 7 Tri(jla (jurnardus. Trigla cuculus. 1 Baia clavaia, 11 1 in. across the pectorals. Sixteenth haul, 8.30 p.m., June 9th. On this occasion I timed the various stages in the operation of hauling one trawl and shooting the other. The after stopper, which fastens the wire trawl-rope to the quarter of the vessel, to keep it clear of the propeller, was let go at 8.30 p.m. The steam winch was then set in motion and the beam of the trawl was on the rail at 8.40. By 9 o'clock the cod end was hoisted up, the fish emptied out of it and the other trawl shot. This haul we steered somewhat to the westward, to get away from the small plaice ; but the captain said he was afraid we should get away from the soles, too. The catch was not a large one : — 1\ baskets medium plaice. 1 basket small plaice. 1 „ gibbed haddock. 2 baskets kit haddock. 35 turbot and brill. 25 pair of soles. NORTH SEA INVESTIGATIONS. 45 2 ripe female sprats, 1 hake, and 1 Acanthias vulgaris were also taken. About 2 basketfuls of small plaice, dabs, and gurnard thrown over. Seventeenth haul, 2.o0 a.m., June lOth. During this haul we steered again towards the land, with the result of getting more small plaice and more soles, and fewer haddock. The fish saved were : — 4 baskets medium plaice. 11| „ small plaice. 2 „ haddock. 1 basket codling and dabs. 48 pair of soles. A few brill and turbot, and a dozen latchets. About 20 basketfuls of small plaice, &c., thrown over. Eighteenth haul, 8.;30 a.m., June 10th. At 8 a.m. Heligoland was plainly visible, bearing S. by W., and about 14 miles distant. The fish saved were: — a -u ^ ^ ^■ ^ • 4 baskets medium plaice. 1\ „ small plaice, i- „ gibbed haddock. 2 „ kit haddock. 14 pair of soles, the smallest 9| in. About 27 turbot and brill. The smallest plaice was 6| in. long. There was a quantity of soft dark-coloured fine sand among the fish. Nineteenth haul, 2.30 p.m., June 10th. At 1 p.m. Heligoland was bearing S.S.W. The fish were on deck at 2.50 p.m., and at 3.10 many of the small plaice, dabs, &c., were being shovelled overboard, and many were alive. Those shovelled over towards the end of the work of sorting and gutting are nearly all dead. I counted the sexes in a number of the larger or medium-sized plaice, and found 99 females to 43 males, the largest female being 16^ in., the largest male 1G| in. The smallest plaice in the haul was G in. long. According to the mate's reckoning, there were only 8 pair of soles ; I counted 32 soles, the mate neglecting the slips. The small plaice were very abundant, the other fish saved ° ' 4i baskets medium plaice. 13 „ small plaice. 1 basket haddock. 1 „ dabs and codling, 1 large cod. 14 turbot and brill, 1 small turbot being only 9 in. long. Twentieth haul, 8.30 p.m., June 10th. We steered to the north and somewhat nearer to the land this haul, in order to find more soles : we 46 NORTH SEA. INVESTIGATIONS. were out of sight of Heligoland. We sounded 71 fathoms some time before G.4o p.m., and at that time 10 fathoms, the ground being sharp gravelly sand. There were a large number of German " snibs " in sight. These vessels are of shallow draft, only partially decked, and smack rigged. They carry small trawls, only about 20 feet long, which they pull up by hand. Tliey must take a large number of the small plaice, but whether they destroy them or not I do not know. Probably they fish principally for the sake of the soles. This haul produced more soles and fewer plaice than the previous one, which was taken further to the southward : — 1 basket medium plaice. 6 ,, small plaice. 3?) pairs of soles. 1 turbot 9 in. long, 1 turbot 92 in. Twenty-first haul, 3 a.m., June 11th. As usual in a night haul, soles were taken this time more abundantly : no detailed observations on the fish were made by me. The marketable part of the catch comprised : — 1 basket medium plaice. 5 „ small „ 2 „ haddock. 50 pairs of soles. 19 turbot and brill, none large. 3 latchets, a few whiting, dabs, and codling. Twenty-second haul, 10 a.m., June 11th. This was the last haul: we started at full speed for Grimsby at 10.20. At 9 a.m. Heligoland was in sight, bearing S. by W. 15 to 18 miles distant and I counted 25 foreign " snibs " in sight. This haul there were taken 25 turbot, 8 brill. I examined a number of them, namely, 15 turbot and 3 brill. Of the former 12 were mature males, G of them 13 in. long ; 2, 14 in. ; 1, 19 in., and 3, 20 in. Of the 3 females, one 15 in. long was immature, two 22 in. long were mature. Of the brill two were mature males 10 in. and 14^ in. long, the third was an immature female 12 in. long. The rest of the fish saved were : — 3 J baskets medium plaice. 4 „ small „ 3 I „ haddock. 10 soles — 4 large, G slips. Some whiting, latchets, and cod. In one haddock's stomach I found Trophonia, whitings, and a dab ; in another, brittle stars. NORTH SEA INVESTIGATIONS. 47 I landed at Grimsby on the afternoon of June 12th and on June 13th examined at Cleethorpes some of the fish I brought from the steamer on which I made the voyage. Among these were 9 soles, of the size at which they are called slips, that is to say, the smallest soles caught. They were 10| to 11^ in. in length, and all of them were mature males. I also brought a basket of the refuse from the last haul. It proved to contain : — 105 male plaice, smallest 6i in., largest 11| in., next largest 10 in. 71 female plaice, smallest 6f in., largest Hi in., next largest 11 in. and lOi-in. 31 male dabs, 5| in. to 10^ in. 21 female dabs, 5 in. to lOf in. 6 Trigla gurnardus, 9i to 11^- in. ' I examined the ovaries of a few of these fish microscopically : Plaice 8 in. long, ovary small, ova yolkless, no opaque masses. „ 8 in. long, „ „ „ „ o;j m. „ „ „ „ „ o^ m. ,, ,, ,, ,, „ 9-|-in. „ ovary small, but opaque masses very distinct and numerous „ 10^ in. „ one or two dead eggs in ovarian tissue. „ lOfin. „ ovary 2 in. from anterior end, 3 ^'a ^^- from posterior end of ventral fin. No opaque masses. Plaice 10|in. Opaque masses numerous, small, nearly absorbed. „ 11 in. Opaque masses and dead yolked eggs very numerous and conspicuous. Dab 71 in. Probably spawned, but ovary small and transparent, no opaque masses or yolked eggs. „ 8|in. Ovary l^in. from anterior end, 2^ in. from posterior end of ventral fin. Almost certainly recently spawned, some partially yolked eggs present, but not dark and opaque as in the plaice. „ 7i in. Ovary half as long as the ventral fin, red in colour, contained some half-ripe eggs, but not dead yolked eggs as in the plaice, I must postpone the discussion of these observations until a future occasion. [ 4S ] Faunistic Notes. JANUARY TO JUNE, 1895. By E. J. Allen, B.Sc, Director of the Plj^mouth Laboratory. The following notes on the collecting work carried out during the period from January to June, 1895, follow the lines of Mr. Garstang's notes for 1892* and 1893.t In putting the observations on record, I should like to thank the various workers at the Laboratory during the period covered, for the help which they have given. My own part of the work has consisted chietly in keeping the record, and in en- deavouring to give a certain amount of continuity to the whole. At the same time the final responsibility for the names adopted must be my own. What strikes one perhaps most forcibly in keeping a detailed record of collecting operations such as are carried out by the Association, and comparing it with previous records and observations, is the great relative variation in the abundance of different forms from year to year. In any particular year, animals which at a given season are usually quite common, may be almost entirely absent, whilst other forms usually regarded as rare may be taken in great abundance. Several instances of this kind will appear in what follows, and it is from this point of view that such records are likely to be of the utmost value, if continued from year to year. It is only by their means that the modifications of the fauna and flora of any district, due in the first place to the direct action of physical conditions, and in the second to the inter-relations of the various organisms which compose it, may be expected to receive anything like a complete explanation. * This Journah Voh ii. N.S. p. 333. t „ ,, Voh iii. N.S. p. 212. FAUNISTIC NOTES. 49 Ttibularia indivisa has been unusually abundant, and several colonies with polyps of exceptional size for this locality were taken near the Asia Eock, during the latter half of March. This species was also growing in profusion on the rocks below West Hoe Terrace about the same time. Tuhularia indivisa, of a more luxurious growth and redder colour than that found in the Sound, was taken on May 8th from beneath the overhanging shelf of rock below the remains of the old lighthouse at the Eddystone. It was growing there in considerable quantity, side by side with a species of Aglaophenia, which will be described by Prof. Nutting, Tuhularia larynx, which appears to have been common in the Sound in former years, has not been so during the present season. Garvcia nvtans, which has been regarded as a rare form at Plymouth, has been plentiful this spring. It was continually found on the stones dredged in Millbay channel, and on April 8th numerous colonies, covered with gonophores, were growing on the rocks under West Hoe. This species has not, I believe, been previously found at Plymouth between tide marks. A small species of Eudcndrium, of very delicate habit, and at once recognisable by the milk-white colour of its polyps, which Prof. Allman is inclined to regard not as Uudendrium ca2nllare, which it resembles in some points, but as a new species, was found in large quantities on stones taken from Millbay channel, and bore gonophores during April. On the 25th and 2Gth of April, a species of Syncoryne, resembling Syncoryne mirabilis of Agassiz, bearing meduste of two kinds, was found by Mr. Garstang at Devil's l*oint and Garden Battery. This species will be described by Mr. Garstang in detail. On May 9th another species of Syncoryne, resembling Syncoryne eximia, but of rather more delicate habit, with the tentacles already formed on the zooids, was found growing on the roots of Laminaria on a buoy moored near the Eddystone. The interesting hydroid Corymorpha nutans has again been obtained. The last recorded instances of its capture at I'lymouth is by Mr. Heape,* on May 17th, 1887, in about three fathoms, below Fort Tregantle, in Whitsand Bay. On May 20th of the present year, we succeeded in obtaining three specimens with the dredge, olf the same fort, in about nine fathoms, and one mile from shore. One of the specimens had medusiX! attached. On the following day. May 18th, our fisherman, Poach, tried with the dredge a patch of sand at the east end of the Breakwater, and succeeded in taking two specimens. From the abundance in which the medusii; of this species occur here during * This Journal. Vol. i. N.S. p. 394. New Series.— Vol. IV. No. 1. E 50 FAUNISTIC NOTES. the spring and early summer, it seems probable tliat the hydroid grows in large numbers somewhere in the neighbourhood, and it is curious that it should be so seldom taken. Medusie were very late in appearing this season. Daring January not a single one was seen, and only one or two Leptomedusa^ were taken occasionally in the latter half of February. It was not until the middle of March that they began to be met with in any numbers, when the tow-nets contained a good many specimens of the. Anthomedusa, Amjyhicodoji amphiplcurus of Haeckel (March 15th and onwards), each having numerous medusa buds springing from the base of the tentacle bundle. A few specimens of Corymoiyha nutans (Stcenstrupia rubra) also appeared about this time. Leptomedusa? {riiialidiurii sp.) were still found in small numbers, but were not plentiful. Towards the end of March they became numerous. During April Ani2)hicodon generally showed gonads developing on the manubrium, and in May (first seen May 9th) the young hydra form was found inside the umbrella. At the beginning of April two species of Tiaropsis, which will be discussed in detail by Mr. Garstang, were present, and the larger species continued to be taken, the specimens gradually increasing in size, until the end of May. Sarsia pulchella and Margclis [Boiigainvillia) ramosa, L. Agassiz, both of large size, were fairly common during JMay. Specimens of liathkea odopundata were also taken during the same month. From May 21st onwards, medusffi of the Phialidium group, bearing the parasitic Ilalcampa sp. inside the umbrella, were common. The first Ephyra was observed on February 19th, but Ephyrae did not become plentiful until the beginning of March. A month later only Ephyrae of the largest size were taken, and on May 28th the first fairly grown Aurelia (about 3 in. diameter) was seen. On April 29th a small specimen of Chrysnora isosceles (about | in. diameter) was taken, and towards the end of May fair-sized specimens of this medusa were common. The Lucernarian Depastrum cyathiforme, which has been taken twice before at Plymouth,* once at Drake's Island and once under liame Head, has been found on two occasions this year; on February 12th on the shore below Mount Edgcumbe, and on May 15th below Mount Batten. Bolina hydatina, referred to by Mr. Garstangt as having been noticed during May, 1892, and again in May, 1894, but as being apparently • This Journal. Vol. iii. p. 216. t This Journal. Vol. iii. p. 216. FAUNISTIC NOTES. 51 absent during 1893, has been taken this year on several occasions, as before, during the latter half of May. Large colonies of Alcyonmm digitatum have again been growing on the iron piles of the Promenade Pier, a position in which they were found last year. Post-larval stages of Arenicola similar to those described by Dr. Benham * in this Journal, which have previously appeared in February, were not found until nearly a month later than usual, the first recorded being taken on March 25th. A corresponding lateness in the appear- ance of the regular constituents of the floating fauna, as compared with previous records, has been very marked during the early part of this year. A specimen of Sipunculus nudus about 5 in. long was brought to the Laboratory on April 2ud by a fisherman, having been taken whilst trawling. On the 5th of the same month, our own man was on board a Ply- mouth trawler, obtaining fertilised eggs of flat-fishes, when another specimen of about the same size was taken ten miles soutli of the Eddystone light. Amongst the Nudibranchiata large specimens of Aplysia punctata (5-6 inches long when extended) have been abundant in the Yealm Piver, and have been spawning freely in the tanks during May and June. Hero formosa has been found in considerable numbers six miles south of the Mewstone, and Triopa claviger, of which two specimens have been previously recorded at Plymouth, f has again been taken off the Mewstone. Four specimens were found on a mass of the Polyzoan Leprcdia foliacea on May 28th. On February 6th Mr, Sumner found on the dredging from Millbay channel two specimens of Cutliona aurantiaca (A. and H.), a form which has not previously been taken at Plymouth. The remarkable scarcity of the common shrimp (Crangon vidgaris) in the Sound, during the past six months, is a fact worth putting on record. On spots where one haul of the trawl in an ordinary year could have been relied on to bring up many hundreds of shrimps, we could only obtain a dozen or so at each haul during the early mouths of the year. This scarcity still exists, though the numbers appear to be increasing. It is dilllcult to su<:ci » 1 « . o| ,, 1 sole . 5| in. long. There were no other flat fishes in the tank, which was one of the table-tanks in the Laboratory of the Association, at Tlymouth. It was 5 ft. long, 2 ft. G in. wide and 15 in. deep, and its sides and bottom were of slate, the front of glass. I was surprised to notice that all these flat fishes were partially pigmented on their lower sides. At first this appeared to be a complete nullification of the conclusions drawn from my previous experiments, but further examination of the matter gave it, a different interpretation. 54 PIGMENTS OX THE LOWER SIDES OF FLAT FISHES. In the sole there was very little pigmentation on the lower side, only a little at the base of the tail, and on the lower surface of the tail, but in the plaice and flounders the pigmentation extended continuously over the marginal region of the body and the proximal part of the dorsal and ventral fins. The extent of the pigment in the smaller ilounder is shown in Fig. 1. The pigmentation of the outer half of the marginal fins was slight. In the larger flounder the pigmented area on the surface of the body was broader ; the central area was unpig- mented, with the exception of a narrow patch about the middle of the lateral line, as in the smaller specimen. In the two plaice the pig- mentation was not quite so intense and not quite so extensive. In both it was absent, or very nearly so, from the surface of the marginal fins, and from the anterior part of the body, with the exception of a small Fig. 1.— Under side of Flounder, showing pigmentation. patch on the bony ridge of the head in the smaller specimen. In both it was present in the regions of the interspinous bones in the posterior three-fourths of the body, both dorsally and ventrally, and also over the whole lower surface of the caudal fin, absent from the central region of the body entirely ; there was no patch on the lateral line, as in the flounders. It will be clear, therefore, that there was a most remarkable similarity in the distribution of the pigment in these four specimens, which suggests a common cause acting in all of them, and not indefinite " variation." This common cause was access of light to the pigmented areas. There was no sand or gravel at the bottom of the tank, and the fish were resting on the bare slate. The lower surfaces of the fish were not perfectly flat, and therefore certain areas were, when the fish were at rest, in contact with the slate, while other areas were separated from PIGMENTS ON THE LOWER SIDES OF FLAT FISHES. 55 the slate by an interval. The areas of contact were shown by dropping the smaller flounder, in the moist fresh state, on a surface of dry slate, when the areas in contact moistened the slate, while the part of the slate not touched by the fish remained dry. Fig. 2 is a diagram of the impression thus produced on the slate by the fish, and it will be seen that it is a remarkably exact negative of the distribution of the pigment on the lower surface of the fish. The projection of the area of contact towards the dorsal edge of the fish is not so extensive as the unpigmented area on the dorsal region of the body of the fish, and the tail is in contact with the slate. But in view of the exact correspondence in other respects, these differences are easily explained, and do not invalidate the evidence. The white patch Fig. 2:— Iiupressiou of under side of Flounder on dry slate. in Fig. 2, corresponding to the area of pigment on the lateral line, and the remarkable correspondence of the area of contact ventrally with the outline of the pigmented area in the fish, as shown in Fig. 2, are sutliciently striking. With regard to the isolated patch of pigment on the lateral line, a difficulty arises. Since this small area is an island surrounded everywhere by surfaces in contact with the bottom, how could light reach it ? In order to prove that light does reach the pigmented areas, I had recourse to photographic action. The same flounder was placed, while still alive, on a sheet of bromide printing-paper in the dark room, and then exposed for a few seconds to daylight, to light coming horizontally. The result of one such experiment is shown in Fig. 3. Here, again, 56 PIGMENTS ON THE LOWER SIDES OF FLAT FISHES. the darkened area of the paper corresponds with remarkable exactness to the pigmented area of the fish, and, most remarkable of all, there is a small darkened patch corresponding to the isolated pigmented patch on the lateral line of the lish. In this particular photographic print the outer region of the bromide paper, beyond the edges of the fish, is lighter than the outer part of the area covered by the fish. This is simply due to the over-exposure of the uncovered area of the paper, causing a partial reversal of the photographic effect. It must be concluded that the rays of light which reach the small depression on the lateral line of the fish pass parallel to the surface of the fish, and therefore do not fall upon it ; but when they reach the edges of the depression they are slightly refracted, and so Fig. 3. — Reproduction of impression produced by exposing a sheet of bromide photographic paper, with a Flounder lying upon it, to the action of diffuse light, and subse > > „ 10th „ 14th 94 . 67 . 61 . 102 . .. 9 .. 25 . 13-5 .. . 24-7 .. — — )i ») ,, 20th 276 . 160 . .. 27 . 16-9 .. . — .. — .. — 1) }i 1893. Feb. 20th 310 .212 . .. 49 . 23-1 .. . — 4 .. — )» ji May 17 th June 13th 277 . 270 . 246 . 309 .. 46 .. 64 . 17-0 .. . 20-7 .. . — ... — ... 5 >5 JS Caught since May 17th. July 13th 111 . 138 . .. 64 . 46-4 .. . — .. — .. 21 Caught since June 13th. „ 25th 106 . 171 .. 45 . 26-3 .. . 2 .. — .. 3 Unsorted catches. "For the better understanding of these figures, the following must be mentioned : — "The "black" females are reckoned as egg-bearing, since, under natural conditions, i.e., if they had not been confined in the cages, they would have spawned. * Herrick found, however, among about 3,000 animals, a slight excess of females, t Herrick {Zool. Anz. 1891, p. 134) has given a similar table, which, however, does not give the same result. THE REPRODUCTION OF THE LOBSTER. 65 "As regards the first three entries, which relate to July 25th, August 13th, and September 14th, 1892, it cannot be maintained that the catches still retained sufficiently closely the natural composition which they possessed when first taken. In the summer the dealer sorts his wares, in order to render selection for sale more easy. He divides the small from the large, puts such lobsters as are about to moult in a special part of the cage (it is in this way that the animals enumerated on the 25th July, 1892, are divided), and prefers to sell the females without eggs on the abdomen first, in order to guard against their becoming " black." The latter circumstance is the cause of the percentage of egg-bearing females, in the first three entries on the list, being somewhat higher than in the following. In calculating the mean, however, this is hardly noticeable. The last ten enumerations are all made, on the other hand, on material which had not yet been sorted, and which therefore possessed the original constitution of the catch. Care was also taken that nothing should be counted twice, for each time new cages which had not previously been looked through were examined. " Eeckoning the whole thirteen entries, the mean percentage of egg-bearing females is 25*4 per cent. ; the last ten, it is only 23 per cent. " It will not, therefore, be an error to maintain that never more than the fourth part of the female lobsters capable of reproduction actually carry eggs ; or, in other words, that a female lobster, as a rule, actually produces eggs only once in every four years." * Few will be inclined to object to the author's exclamation, "Das ist eine Thatsache, die allerdings zu denken giebt ! " but whether, as a result of the thinking, all will be ready to accept the conclusion arrived at, is another question. At first sight, the argument presented appears to be conclusive, but a little consideration will, I think, lead to the conclusion that at least one other explanation of the facts is possible, for it must be borne in mind that Ehrenbaum was not dealing with the number of lobsters living in the sea, but with the number caught in the traps. It is, to say the least, not improbable that a female bearing eggs would be much more wary of entering a trap than one not so encumbered, especially if the trap already contained other lobsters, including females without eggs. The pugnacious habits of these animals are matters of common experience, and I have, on several occasions, known two of them, conihied in one tank, continue their * "A false interpretation of the facts can only be possible in so far that perhaps, some- times, females may have been counted as 'not egg-bearing,' altliough they were slightly uiuler 24 cm. (9^ inches) long, and therefore not yet capable of reproduction. So far as could be judged by the eye, however, the young animals not yet capable of reproduction during the enumeration, were always left on one side." New Seiues.— Vol. IV. No. 1. F GG THE REPRODUCTION OF THE LOBSTER. warfare until one or the other has been killed. The loss of claws and legs is of quite frequent occurrence ; and the fisherman, before confining lobsters in a store-pot, invariably cuts the pincer muscles of the big claws, in order to prevent them injuring each other. Even if no instinct corresponding to maternal jealousy exists amongst these animals, a female bearing eggs is placed at such a physical disadvantage, that it is not unlikely that she would be more cautious of entering a confined space with other lobsters. At any rate, this consideration should be borne in mind when drawing conclusions from the results arrived at by Ehrenbaum. An examination, made at the end of July, of the ovary of a female whose brood had just been hatched, did not appear to me, in itself, to ofTer evidence for or against the view that eggs would not be laid even during the same summer. The ovaries were found to extend from the anterior end of the cesophagus to the middle of the third segment of the abdomen. The eggs were of a dark green colour, and in a lobster 30.5 cm. long, many of them had a diameter of as much as 1.2 mm. If no further evidence of a different kind were forthcoming, one would, I think, have been inclined to expect that these eggs would be laid during the same summer. It seems to be very important for the settle- ment of these questions that the rate of development of the eggs in the ovaries of lobsters kept under conditions as normal as possible should be determined, but this, of course, involves many dilliculties. It could, probably, only be satisfactorily undertaken where the lobsters could be confined in a large tidal pond from which they were unable to escape but from which the water could at intervals be drawn off completely. The number of eggs laid by a lobster becomes very much greater as the age of the animal advances. This appears to be true, both of the American and European species. A female 8 inches long, according to Herrick, carries from 3,000 to 9,000 eggs, whilst in one measuring IG^^ inches, the number was 85,000. As the result of an examination of nearly a thousand individuals, this author finds that "the numbers of eggs produced by a female lobster at each reproductive period vary in geometrical series, while the lengths of the lobsters producing these eggs vary in arithmetical series." Thus an American lobster 8 inclies long produces 5,000 eggs. 10 „ „ „ 10,000 „ 12 „ „ „ 20,000 „ U ,> » „ 40.000 „ 11^ ,. » ,. 80,000 „ THE REPRODUCTION OF THE LOBSTER. 67 Ehrenbaum finds a similar state of things in the Heligoland lobster, although the actual number of eggs on individuals of the same length appears to be less in the European than in the American species. The following table gives the German naturalist's chief results on this head* : Total length of Lobster. 25.4 cm. (10 inches) 28.1cm. (11-iV „ 29.1 cm. (Hi 2P.5 cm. (HI 29.2 cm. (11^ ,, 31.0 cm. (12f 31.1 cm. (12i 35.5 cm. (14 ,, 37.3 cm. (15 Estimated number of eggs, including Number of those lost after eggs animal is counted. caught. 7,026 8,000 7,376 8,000-8,500 8,420 9,009—9,500 13,532 14,000 10,330 ... 11,000 16,800 ... 17, .500 10,307 ... 11,000 20,016 ... 22,000 29,000 ... 32,000 An account of the number of eggs produced by the individual leads to the consideration of what Herrick calls the " law of survival of the larvffi." From the figures given for the American species, it is evident that the total number of eggs produced during the entire life of a female which reaches the length of 16 inches, must be very large, even should Ehrenbaum's conjecture that spawning takes place only once in four years prove to be correct. The question which presents itself is, what proportion of this large number of eggs must develop into sexually mature lobsters, in order to maintain the species in its existing numbers ; and the answer to this question would be completely given if we knew (1) the relation of the total number of females existing to the total number of males, and (2) the number of eggs produced on the average by a sexually mature female during the whole of her life ; for it is only necessary that each female should give rise to two sexually mature individuals in order to accomplish the result, if the number of males is not greatly in excess of the number of females. It is known, from observation, that the males are not greatly in excess, but the average number of eggs produced by females during the course of their lives is more difficult to ascertain, as we have no know- ledge of the number of individuals destroyed at different ages. Many, no doubt, of those which lay their first brood are destroyed before the eggs are hatched, whilst of those which survive, a constantly diminishing number produce a second, third, or fourth lot of young. This, however. * In comparing Ehrenbaum's figures with those of Herrick, it must not be forgotten that those of the latter author are based on an examination of nearly a thousand individuals, whilst those of the former are in each case the result of counting the eggs of a single female. F 2 68 THE KEPRODUCTION OF THE LOBSTER. is in part compensated by the fact that tlic number of eggs produced increases so rapidly with the increase in size of the lobster. Herrick makes the exceedingly moderate statement that, taking into account "the fact that the species, as a whole, does not appear to be maintained at present at an equilibrium, but rather to be actually on the decline, a little reflection will convince anyone that the destruction of the young of this species in nature, must be much greater than that entailed by the survival of 2 in 10,000." But this estimate appears, from a consideration of all the facts, to be considerably too low, and we should, I believe, be well within the mark in placing the figures at 2 in 30,000. It must not be lost sight of that the number of eggs that it is necessary for a female to produce to maintain the species at an equilibrium, in other words, the number of eggs actually produced by each female, had become a fixed quantity before there was any interference on the part of man in the way of lobster fishery, as we must suppose that the species was then adapted to its conditions. Lut, since the introduction of lobster-fishing has done nothing to increase or diminish the dangers to which the larva is exposed after it has become free,* the number of eggs now produced, on an average, by a female lobster during her lifetime, will give us an indica- tion of the minimum number of eggs necessary, in order to ensure the survival to sexual maturity of two individuals. From the Report of the Newfoundland Department of Fisheries for 1893, p. 39, it appears that from a total of 96,098 female lobsters taken from 1890 to 1893, the number of eggs collected was 2,247,908,000, which would give an average of 23,000 eggs for each female. This is the average number of eggs actually carried. But a female with 23,000 eggs would, according to Herrick's results, have a length of more than 12 inches, and would, therefore, from the known average age at which spawning commences, be carrying, at least, her second brood. Under these circumstances 30,000 eggs, on the average, to each female during her lifetime, must be well within the mark and the number of survivors necessary, therefore, to maintain the species cannot be more than 2 to every 30,000 eggs. As Herrick points out, attempted remedial measures, which are confined to the mere hatching of lobster eggs, and turning the larvae immediately into the sea, can have but little practical effect. The rate of destruction will be at least as great as in the case of larvie hatched by the parent, and, on the estimate given above, two, at most, will survive out of every 30,000. This method of attempting to benefit the lobster industry has been extensively used in Newfoundland, and it is * It may, of course, be maintained that the capture of other fish has tended to reduce he number of enemies of the hirv.'e. THE EEPRODUCTION OF THE LOBSTER. 69 interesting to calculate what the probable effect of the operations there being carried on is likely to be. From the Report of the Nctvfoundland Department of Fisheries for 1893, it appears that the largest number of ova dealt with in any one year was 696,517,690, in 1891. Calculating the number of survivors at 2 in 30,000 (as a matter of fact, 20 per cent, were lost before hatching, a much greater number than would be lost under natural conditions), this would give 46,434 adult lobsters added to the neigh- bourhood. Even if all these 46,434 were caught, the percentage of increase on the whole fishery (a little over 5,000,000 in 1893) would be 0"9 per cent. A consideration of the steps by which this conclusion has been reached will, I think, leave the impression that it is still far too high, and that a very much smaller percentage would much more nearly represent the truth. As to whether the result is sufficient to justify the trouble and expense involved in bringing it about, I will not venture to express an opinion. If the larvee could be reared through their early pelagic stage and not liberated until their natural instincts lead them to seek the bottom and hide themselves, the result would, as Herrick maintains, be pro- bably very different ; but if this could be successfully done on a large scale, as no doubt it might be if sufficient capital were put into the undertaking, there seems no reason why the young lobsters should not be reared to the adult stage, and to marketable size, and not turned into the sea at all. An undertaking of this kind, carried out on a scale similar to that upon which oyster- farming is conducted on the Continent, might very probably be made a success. [ 70 ] Additional Observations on the Nerve-Elements of the Embryonic Lobster. By E, J. Allen, B.Sc. Director of the Plymouth Laboratory. In Vol. III., No. 3, p. 208, of this Journal, a summary was given of certain observations made in the Plymouth Laboratory on the nerve- elements of the embryonic lobster. A more detailed description of these elements, with figures, appeared in the Qitarterly Journal of Microscopical Science, vol. 36, 1894. The observations have since been extended, and the following summary of the additional results may not be without interest. In the detailed paper a pair of elements (Element B) was described occurring in the ganglia Thorax II., Th. V., and Th. VIII., each of which consisted of a cell lying in the lateral mass of ganglion cells, which gave off a fibre decussating with its fellow of the opposite side, and then running forward to the brain. Before leaving the ganglion in which the cell lay, the fibre gave off a pair of branches, one going to the ganglion immediately in front, the other to the ganglion immediately behind, the branches breaking up in the neuro- pile of each of these ganglia. Thus Element B, in Th. II., sent a branch to Th. I. and to Th. III. ; Element B, Th. V., sent branches to Th. IV. and Th. VI.; Element B, of Th. A'lII., sent branches to Th. VII. and Th. IX., the main fibres running forward to the brain. A precisely similar element has since been found in Th, XI., sending branches to Th. X. and Abd. I., so that the series is now complete for the thorax, and each of its ganglia appears to be influenced by these elements, the fibres of which arboresce in a particular region of the brain. A number of additional motor fibres, which cannot well be described without drawings, have also been observed in the thorax, some of which resemble those figured in the former paper, whilst others differ from THE NERVE-ELEMENTS OF THE EMBRYONIC LOBSTER. 71 them in essential details. Some of these motor elements send their fibres out of the cord through the anterior nerve roots, others through the posterior. The motor elements previously described are all characterised by the fact that the fibre leaves the central nervous system through one of the roots of that ganglion in which the cell attached to it is situated. The portion of the element which lies within the central nervous system is therefore entirely confined to one ganglion. In a number of elements, which have since stained, whilst the cell lies in one ganglion, the fibre passes out of the cord by the nerve-root of some other ganglion. In one such element, the cell lies in the anterior portion of the central mass of ganglion cells of Th. VII., and gives ofi' a fibre which runs outwards and then upwards, to Th. VI., where it passes out by the posterior root of the ganglion. The fibre gives off a stout arborescent branch in Th. VII., and a straight transverse branch in Th. VI., which passes across to the opposite side of that ganglion. Of elements belonging to new types, perhaps the most interesting are those which, taking origin in a single cell, have two or more branches, which pass out of the central nervous system by the nerve-roots of different ganglia. For example, a cell lying in the anterior portion of the lateral mass of ganglian cells of Thorax VI IL, gives off a moder- ately fine fibre, which very soon bifurcates, one branch passing immediately out of the ganglion through the anterior nerve-root, whilst the other runs forwards along the ganglionic cord. The forward branch pursues a perfectly straight course until it reaches Th. III., where it gives off a branch, which passes out through the posterior root of that ganglion. After giving off this branch the fibre continues to Th. II., where it turns and leaves the ganglion through the posterior root. Hence this element, the cell of which lies in Th. VIII., sup- plies fibres to at least three nerve-roots of different ganglia, namely, the anterior nerve-root of Th. VIII,, the posterior root of Th. III., and the posterior root of Th. IL, and all these fibres have their origin in a single cell. In the Abdominal Ganglia, staining of nerve elements can be obtained in two ways. In the case of embryos in the early or medium stage, fibres which have taken up the methylene blue in the thorax, often continue to absorb the colouring matter in the abdomen, and the cells with which they are connected are thus brought to light. The best results for the abdominal ganglia can, however, be obtained by special preparation of embryos, which are very near the hatching point. In such embryos the abdominal ganglia may be dissected out from the surrounding tissue by careful manipulation with needles. Special care 72 THE nerye-el?:ments of the embryonic lobster. must be taken not to injure or stretch the ganglia, and their continuity with the ganglia of the thorax should be maintained. If the embryo, tlius prepared, be placed with the dorsal surface uppermost in very dilute methylene blue, satisfactory staining of many of the elements of the abdomen will soon take place. The elements of the abdomen belong to types similar to those described for the thorax. In each ganglion a pair of elements exists, taking origin in two ganglion cells lying upon opposite sides. Each cell gives off a fibre, which after decussation with its fellow, passes to the opposite side of the ganglion, and gives off a branch to the neuropile. It then turns forward and runs along the cord to the brain. In this way each of the ganglia of the abdomen is placed in direct communication with the brain. In the sixth abdominal ganglion two pairs of elements of this type occur, thus pointing to the composite nature of the ganglion. A considerable number of motor elements, consisting of a cell in one of the ganglia, and a fibre which passes out of the central nervous system, have stained in the abdomen. These are of two kinds; first, tliose in which the element is confined to a single ganglion, the fibre passing out through one of the roots of the ganglion in which the cell lies, and secondly, those in which the fibre leaves the central nervous system by a nerve-root of a ganglion other than that in which the cell lies. These will be described in detail in a later paper. Further observations have also been made on the sensory nerve elements, which have their origin in cells lying outside the central nervous system. These fibres, on entering a ganglion, make a charac- teristic Y-shaped bifurcation, sending one branch forwards and the other backwards along the cord. These branches have been traced for considerably greater distances than was previously possible, the forward one having been seen to pass through at least nine or ten ganglia. In all probability, all these forward branches go in every case to the brain. The backwardly directed branch has never been actually traced through more than two or three ganglia, and no indication has been obtained as to the locality or nature of its termination. A detailed account of the observations here recorded will be published in the Quarterly Journal of Microseopical Science. [ 73 ] Notes and Memoranda. On a Specimen of Leptocephalus Morrisii. — During the first week of June of the present year, a specimen of Leptocephalus was brought to the Laboratory by a boy, who had found it under a stone on the shore, in a small cove in front of the building. The beach in this cove consists of broken fragments of limestone. The specimen was alive when brought up, and was preserved in formaldehyde. "When I examined it a few weeks later it was entire and in excellent condition, and retained its transparency to a considerable degree in the preserving liquid. The specimen is 11.25 cm. long (4Hn.); the greatest dorso- ventral breadth of the body, a little behind the anus, is 7 mm. ; the breadth in the same direction at the back of the head is 5 mm. The dorsal line rises slightly behind the head. From the tip of the lower jaw to the anus the distance is 5.25 cm., from the tip of the snout to the commencement of the dorsal fin is 3.6 cm. Thus the point at which the dorsal fin commences is nearer to the anus than to the pectoral fin, although, in the fully developed conger, the dorsal fin extends forwards to a point in front of the posterior extremity of the pectorals. In this respect the larval form more resembles the adult common eel {Anguilla) than its own parent. The greatest lateral thickness of the body is just behind the head, and does not exceed 2 mm. Behind the anus it is narrower still. The head, however, is not much compressed laterally, but is rather broad, and flat on the dorsal surface. The length of the head is 8 mm., measured from the tip of the snout to the gill opening ; its breadth is 3 mm. ; its vertical height at the level of the eyes, 4 mm. In characters the head resembles that of the conger very closely. The eyes are large, the exposed front being silvery, except along the dorsal edge, where there is a streak of black pigment. The anterior tubular nostrils and the posterior open ones are present, as in the conger, and the gill opening is a reduced slit in front of the base of the pectoral, as in the latter. The upper jaw is a little longer than the lower, and the angle of the mouth is below the middle of the eye. No bones can be seen in the interior of the body by this examination of the entire animal without further 74 NOTES AND MEMORANDA. preparation ; the myotomes are distinct, numerous, and narrow antero- posteriorly. There are simple, slender, permanent fin rays in the longitudinal fin ; I counted 480 of these, but at the anterior extremities of the fin they were too indistinct to be counted accurately. The end of the tail has the same shape as in the adult conger, the fin passing continuously round it, and the rays being arranged symmetrically and somewhat more elongated than in the dorsal and ventral parts of the fin. The pectoral fin is o mm. long. There is a single linear series of black dots along the middle of each side, each dot being a single stellate chromatophore. There are a few additional chromatophores below the principal series, and also a row alonfj each side of the middle ventral line of the abdomen. At the base of the longitudinal fin, there is a series of chromatophores on each side, one to each fin-ray, continued round the end of the tail to a point about I in. from the apex of the tail dorsally, but there are none on the rest of the dorsal edge of the body. In most respects, as may be seen on comparing the above description with Couch's figure, our specimen agrees well with the latter. The characters of the head are not, however, well brought out in that figure. Judging from our specimen, the eyes are too small, and the character of the mouth and jaws is not shown ; the whole head is also too small. In Couch's figure, too, the body increases more in breadth towards the middle region and in the posterior half than in our specimen, in which the dorso-ventral breadth remains almost uniform in the middle two-thirds of the body, decreasing anteriorly and pos- teriorly. Further anatomical examination must be deferred to some other opportunity. I will only add here that the character of the larva suggests to myself the idea that it corresponds to special conditions of life, as is the case in other larvie, and that these special conditions are not of the pelagic kind. The head is, to all intents and purposes, the head of a conger, and the like may be said of the longitudinal fin, with the reservation mentioned above. The body is compressed, colourless, transparent, and boneless, and these qualities would, I think, be fostered, if not produced, by the habit of living under stones and in narrow crevices, with comparatively little exertion of the trunk musculature. J. T. CuXiN INGHAM. NOTES AND MEMORANDA. 75 Cuthona ? aurantiaca. — I am glad to be able to add this beautiful species to the Kudihranchiate fauna of Plymouth. Two specimens were found amongst some dredging from the Millbay channel, on February 6th, 1895. On the same stone there was a colony of Antennulana ramosa, which most likely formed the food of the Nudi- hranch. One of the specimens had deposited spawn on the same stone. The interest of this lies in the fact that Alder and Hancock mention this animal as spawning in June and July, whereas this specimen spawned on or about the 6th February. I think there can be no doubt that this spav/n belongs to the Eolid, as it exactly answers Alder and Hancock's description of it, and, moreover, no other Nudihranchs were found in the dredging. During the short time I kept these animals alive, like so many other Eolids, they exhibited a partiality for floating on the surface of the water, foot uppermost. J. C. Sdmner, [ 76 ] Director's Report. The issue of the present number of the Journal, which commences Volume IV. of the New Series, has been delayed in consequence of the publication of the Special Number containing ]\Ir. Holt's memoir on " An Examination of the I'resent State of the Grimsby Trawl Fishery, with especial reference to the Destruction of Immature Fish," which was issued to members in June. I am glad to be able to state that this special number has met with a most favourable reception. It is recognised on all hands that Mr. Holt's memoir constitutes the most serious and successful attempt which has been made for some time past, to place before the general public an accurate and scientific account of the facts relating to one of our most important in- dustries. As the reports now published show, Mr. Cunningham has continued to carry forward the investigation of the North Sea fishing grounds, and his observations form an important contribution to our knowledge of the subject. During the time which has elapsed since the appearance of the last regular number of the Journal, the work of the Association at Plymouth has suffered somewhat from the difficulty experienced in obtaining the services of a suitable naturalist to carry on the fishery investigations, which it had been hoped that Mr. Holt would have been able to under- take. The difficulty is, I am glad to say, no longer present, Mr. F. B. Stead, B.A, of King's College, Cambridge, having been appointed by the Council to carry on this branch of our work. An addition to the regular stall" has also been made by the appointment of Mr. T. V. Hodgson to the post of Director's Assistant. A. J. Smith, from the Cambridge Morphological Laboratory, has held the position of Laboratory attendant since the beginning of April, and in a large measure has charge of the preservation of specimens for sale. It is hoped that by improving the quality of the specimens sent out by the Association, the demand for them will become greater and our useful- ness in this direction extended. Considerable expense has been incurred in overhauling the engines and pumps, and putting them into a state of proper working order director's report. 77 The ejector, used for forcing water from the sea, has again been a source of trouble. The iron rod supporting the lower bucket of the automatic valve had rusted so seriously, that it was no longer able to bear the weight, and the bucket became detached. In order to repair this defect it was necessary to remove the cover of the lower chamber of the apparatus, an undertaking of some difficulty. The matter has, however, now been put right, the iron rod having been replaced by one of Muntz metal, which, it is hoped, will better resist the action of the sea-water. The engines and rotary pumps are also being put into a state of thorough repair. The new system adopted for supplying the tanks in the Laboratory with sea-water has shown itself to be a decided improvement upon that originally used. It may be of interest to describe somewhat in detail the method now employed. Water is pumped from the sea at higli tide — when possible, only at the highest spring tides — into one of the large underground reservoirs. From thence it is pumped twice daily into the tanks in the centre of the Laboratory upstairs. In the intervals between the pumpings (twelve hours) these tanks are allowed to empty them- selves about one-half, the water running from them falling into the Aquarium below. The Aquarium, however, is supplied principally by a constant circulation of water from the second underground reservoir, which thus becomes gradually renewed by the water falling into it from the Laboratory. By this arrangement the water supplied in the Laboratory is such only as has not previously been used, whilst at the same time the water in the second reservoir and the Aquarium is constantly replaced by water from the sea. There can be no doubt that the water now in the tanks upstairs is much better for delicate work than that in the general circulation of the Aquarium. Foraminifera, which formerly did not develop normally in the water, can now be satisfactorily reared, and colonies of hydroids have sprung up on the sides of the tanks. Two shallow wooden tanks, placed immediately under the windows on the south side, have been especially successful. Green weeds have sprung up all around their sides, together with a few tufts of red weeds, and numerous colonies of hydroids, serpulids, and compound ascidians. In these tanks the most varied animals, including Hydractinia, Sponges, Echinus, Aplysia, and Ascidians have remained quite healthy for several months, and appear to be still in the same condition. From this and other experi- ments which I have made, I feel little doubt that the direct action of sunlight upon a portion, at least, of the water is an important factor in keeping it in a satisfactory condition to support the more delicate forms of animal life. It is only in the presence of sunlight also that sea- weeds will grow, and in an aquarium where these grow in quantity 78 director's report. a much more abundant supply of the minute forms of animal life, which serve as food for the larger, is invariably found. A commencement has been made on the work of re-arranging and completing the type collection of specimens in the Museum. Several groups are approaching completion, and it is hoped that before long we shall have a representative series of the fauna and flora of the neigh- bourhood. Two valuable additions have been made to the Library through the kindness of Sir William Flower, and of the Director of the Eoyal Gardens at Kew. To the former we are indebted for a complete set of the Philosojjhical Transactions of the liOj/al Society/ from 1857 to 1886, and to the latter for a bound copy of Buffon's Ilistoirc Naturelle. The Library is still very incomplete, and any addition to it will be much valued. Situated as we are, so far from London, and from any scientific library of importance, it is very necessary that our own supply of liter- ature, both zoological and botanical, should be as complete as possible. A large number of standard works we, unfortunately, do not yet possess. The outdoor work of the Association has been regularly carried on, and several captures of interest have been made. The sailing boat, Anton Dohrn, has been used for work in the Sound, and the small steam tug, Lorna, has been hired for work outside. This boat, however, although very suitable for short distances, is not sufficiently large to make expeditions of any length. A short account of the most note- worthy features of the fauna, and the most interesting captures which have been made, will be found in another part of the present number of the Journal. We have been fortunate in obtaining from the Government Grant Committee of the Eoyal Society, a grant towards the expenses of boat hire in connection with an attempt to extend our dredging and trawling work to the deeper water lying between Start Point and the Eddystone. The unsettled weather of the past month has interfered, to some extent, with this work, but the results so far obtained give promise of the discovery of valuable collecting grounds, which would be within our reach if we had a suitable boat to visit them. These investigations will be continued at every available opportunity during the summer, and it is hoped that some, at any rate, of the results will be ready for publication in the next number of the Journal. I am glad to be able to state that the number of workers who have made use of the Laboratory has somewhat increased. The complete list from the beginning of the year is as follows: — J. C. Sumner, January 2nd to February 28th (Echinodcrm fauna). 11. Assheton, M.A., February 1st to February 15th ( Elasmohranch dcvclojjnient). director's report. 79 E. S. Goodrich, b.a., March 20th to April 4th (General Zoology). L. J. Picton, March 20th to April 4th {General Zoology). T. H. Taylor, March 23rd to April 13th (Polyzoa). W. Garstang, b.a., March 21st to May 1st (Tunicata). G. W. Butler, m.a., April 3rd to May 17th (Teleostean development). Prof. C. C. Nutting, April 12th to May 20th (Hydroids). T. H. Eiches, r..A., April 13th ( Nemcrteans ). T. V. Hodgson, May 27th to June 9th ( AmijMpoda). Dr. P. Barthels, ]\Iay 28th to June 8th (Echinodermata). W. Garstang, m.a., June 2Gth to July 31st (Tunicata). S. P. Bedford, June 29th to August 1st (General Zoology). J. E. Gray, July 2nd to August 1st (General Zoology). Prof. W. F. K. Weldon, f.r.s., June 29th (Variation of Carcinus mojnas. Dr. A. Bethe, July 5th (Nervous System of Crustacea). J. Bancroft, July 8th to July 30th (General Zoology). G. P. Bidder, m.a., July 11th (Sponges). W. J. Beaumont, b.a., July 17th (Faunistic investigations). J. D. Gilchrist, Ph.D., July 20th (Nervous System of Mollusea). Amongst the workers v/e have been glad to welcome the three foreign naturalists who have visited us. Prof. Nutting, of the State University of Iowa, was engaged for some six weeks on the study of the Hydroids found at Plymouth, and succeeded in finding not only several species new to the Plymouth fauna, but also in making a number of interesting observations on the structure of the Plumularidw, a family to which he is devoting special attention. It is hoped that the next number of this Journal will contain a paper by Prof. Nutting, embodying some of his more important results. Dr. P. Barthels, from Prof. Ludwig's Laboratory in Bonn, was occupied chiefly in the preservation of Eclmioderms for future study, whilst Dr. Bethe, from Prof. Hertwig's Laboratory in Munich, is engaged in a physiological study of the nervous system of Carcinus mcenas, side by side with an investigation of the minute anatomy of that structure. The latter researches are of particular interest, as they are being made with the aid of the new method which Dr. Bethe has devised for fixing methylen blue preparations with Ammonium molyhdate. This method is, without doubt, destined to play a most important part in future studies of the minute histology of the nervous system of many forms. There can be no question that it is superior to any means yet devised for rendering the results of methylen blue staining permanent, and it has the immense additional advantage that sections of the preparations can be made after imbedding in parafliu in the usual way. 80 director's report. The list of persons working at the Laboratory also includes five students from Oxford and Cambridge, who have visited us during their vacations, and have engaged in general study of the animals found here^ under the direction of Mr. Garstang. This is, I am convinced, a useful extension of the work of the Laboratory, as the study of living animals, under their natural conditions, has not in the past received that atten- tion at the Universities which is due to it. The students who have worked here have, I believe, acquired a very valuable additional insight into their subject, and a few weeks spent, as it were, in the midst of a marine fauna, cannot but have a beneficial influence on their future studies. It is to be hoped that in future years many more students will visit us in this way, and that those who have been here already will return to carry on research. Professor Weldon has been engaged in an attempt to determine the difTerence in the amount of abnormality in individual crabs at different ages. In order to do this, it has been necessary to fit up an apparatus, by means of which some 500 crabs can be kept in separate bottles, with a current of sea-water running through each bottle. To keep these bottles properly cleaned, and the crabs fed daily, has involved a very considerable amount of labour, and as, in addition to this, the individual crabs have to be measured at at least two different ages, the whole investigation is one which can only be carried on at the expense of a great deal of time and energy. Whatever conclusion, however, may be arrived at as the result of the measurements, there can be no doubt that the knowledge gained will be worth any trouble entailed in obtaining it. On another page will be found Mr. Butler's account of his observa- tions on the breeding of the soles in the Aquarium. As Mr. Butler points out, this is the first occasion since the A(|uarium was opened that these fish have been known to produce fertilised eggs, and is probably the first time that such eggs have been obtained from speci- mens of this fish kept in confinement. Considerable progress has been made in arranging certain groups for the type museum by the three gentlemen, Messrs. Garstang, T. H. Taylor and T. V. Hodgson, who have undertaken this work. There still remains much to be done, and it is hoped that other naturalists will be willing to take advantage of the arrangements made for helping with other groups. E. J. Allen. August, 1895. [ «1 ] glitrint ^tolorjrcal Association of tlje ^Initcb l^ingbom. Report of the Council, 1894-95. The Council. The Council has met on ten occasions during the past year for the transaction of the business of the Association. The average attendance at the meetings has been 7*5. Meetings of Special Committees have also been held as occasion required. For various reasons, it is proposed in the future to hold only four Council Meetings in each year, unless special occasion should arise for increasing their number. Dr. A. Gunther, F.E.S., who had been a member of the Council since its formation in 188-1, resigned his seat in the course of the Session, owing to pressure of other occupations, and was elected a Vice-President of the Association. Mr. 6. C. Bourne, of New College, Oxford, was elected to fill his place. The Council has again to acknowledge the courtesy displayed by the Eoyal Society and the Linn?ean Society, in permitting the meetings of the Association to be held in their rooms. The Plymouth Laboratory. The defects in the large reservoirs, referred to in the last Report, have been made good by draining and cementing on the south side. Some considerable trouble was given last year by a fracture in the large pipe which leads seawards from the ejector; this had been presumably caused by a vessel having dragged her anchor over it ; the repairs, which necessitated the employment of a diver, have been carried out satisfactorily. The Council is now able to give a satisfactory report of the condition of the buildings, fittings, and machinery of the Laboratory. The Boats. During the past year the greater part of the work of collection of specimens at sea has been carried out by hired steam-tugs, supple- Nkw Skuiks. — YoL. I\'. Nil. 1. G 82 KEPOKT OF THE COUNCIL. mented whenever possible by the Association's sailing-boat, the Anion JJohrn. The small steam-launch Firefly, which was most serviceable for this purpose for many years, has been at last sold for breaking up. The Council greatly regrets that there is no immediate likelihood of the Association procuring a suitable boat for deep-sea work. The Library. All the most important annual publications relating to Sea Fisheries are now in the Library, both official publications of most Governments, and publications of fishery societies and local authorities. Several memoirs, containing the results of marine explorations, have been added during the past year, notably the two concluding volumes of the Challenger lieports ; there have also been added memoirs from the German Plankton Expedition, the cruises of H.M.S, Investigator, in the Ray of Bengal, the Commission for Investigation of the German Seas, and tlie Bahama Expedition of the Iowa State University. The Association has also received, by gift and exchange, the publications of the Eoyal Societies of London and Edinburgh, the Zoological Society, the Royal Microscopical Society, the Society of Arts, and numerous other scientific societies, academies, and museums at home and abroad. To these, and to the many donors of books and papers, the Council take occasion to render the thanks of the Association. The Museum and Exhibition Series. Although a good deal has been done in the Museum during the past year, much remains still to be done ; and the Director has been fortunate in obtaining promises of assistance from various naturalists in this important work during the coming summer. The series of specimens mounted for exhibition, to which reference has been made in the last two Eeports of the Council, was shown at the meeting of the British Association at Oxford, in 1894, and is at present at the Scarborough Fishery Exhibition, together with a set of dredges, trawls, and tow-nets. The Staff. Several changes have occurred lately in the Staff. ]\Ir. E. J. Bias resigned the post of Director on October 11th, 1894; and Mr. E. J. Allen, B.Sc, University College, London, who had long been a worker at the Laboratory, succeeded him on January 12th, of this year. Mr. Cunningham is at present stationed at Grimsby. Mr. E. W. L. Holt was unfortunately compelled, by ill-health, to leave the Association's service in March last, and Mr. Stead has been EEPOKT OF THE COUNCIL. 83 appointed for the term of oue year, to carry out, for the Plymouth district, statistical and other inquiries similar to those upon which Mr. Holt has been engaged at Grimsby. Mr. J. P. Thomasson, to whose generosity the Association has been so largely indebted in previous years, has renewed his donation of £250, for fishery investigations on the North Sea for another year, commenc- ing in March last. General Report. Mr. Holt concluded his work at Grimsby in the winter, and has since then prepared an account of his observations on the North Sea Fisheries during the past three years, in a more popular form than the technical papers which he has contributed to the Journal. This summary, which gives a most valuable and unique picture of the present state of the Fisheries, and should prove of great value in the event of protective legislation, has been printed as a special number of the Journal, and reprinted for sale and distribution. Mr. Cunningham has prepared for press a natural history of market- able sea fish, to appeal to a wider public than the Journal can attract, which will also be issued as a special number of the Journal, and reprinted for distribution and sale. This memoir is especially designed for the use of the Sea Fisheries' Committees controlling the fisheries of the English coast. In addition to the preparation of this memoir, Mr. Cunningham has continued his investigations into the rate of the growth of fishes, and the minute structure of the eggs and ovary ; he has also carried out further experiments in the relations between light and colouration of fishes. The water in circulation at the Laboratory has lately improved very greatly in quality under a new system of working introduced by the present Director. Whether as a consequence of this or not, the soles in the aquarium have bred this spring for the first time ; no previous record is known of soles having bred naturally in confinement. After June 30th, the arrangement will terminate, by which the Association has made an annual contribution to the Marine Fisheries Society (Grimsby) in return for the use and control of the Cleethorpes Aquarium by Mr. Holt. The following interesting additions have been made to our know- ledge of the Plymouth Fauna during the past year : Tiaropsis diachmata. Halecuwi tenellum. Plumularia halecioides. 84 REPOKT OF THE COUNCIL. Syncorync mirahilis. A'plidium zostericola. Amara'cium pundum. Distaplia rosea. Circinalium concresccns. Corymorpha nutans, of which no specimens have been taken since 1887, has lately been captured on two occasions. Occupation of Tables. The following naturalists have occupied tables in the Plymouth Laboratory during the past twelve months : E. J. Allen, B.Sc, University College, London (Nervous System of Crustacea). R. AssHETON, M.A., Cambridge (Elasmobranch Development). G. P. Bidder, B.A., Naples (Porifera). E. T. Browne, B.A., University College, London (\'ariatii)n of Auri'lia). G. W. Butler, B.A., Cliertsey (Teleostean Development). G. P. Darnell-Smith, B.Sc., Bristol (Physiology of Algte). W. Garstang, M.A., O.xford (Tunicata). E. S. Goodrich, Oxford (General Zoology). M. D. Hill, B.A., Oxford (Molluscan Ova). J. J. Lister, M.A., Cambridge (Development of Foramiiiifera). Pi-of. C. C. NuTTiNci, State University, Iowa (Ilydroids). T. H. Riches, B.A., Plymouth (Development of Nemertines). J. C. Sumner, Royal College of Science, London (Echinodermata). T. H. Taylor, Yorkshire College, Leeds (Polyzoa). Surgeon P. W. Bassett-Smith, R.N., Plymouth, and Mr. L. J. Picton, Oxford, have also made use of the Laboratory, without formal occupation of a table. The following papers, either wholly or in part the outcome of work done at the Plymouth Laboratory, or by members of the Staff stationed elsewhere, have appeared during the past year, in addition to those published in the Journal : Browne, E. T. — On the Variation of the Tcjitac ulocysts of Aurelia aurita, Ci)uart. Journ. Miir. Sci. xxxvii, 245. Garstang, W. — On the Gastropod Colpodaspis pusilla of Michael Sarx, Proc. Zool. Sof. November 20tli, 1894. SiMNKU, .1. C, — Desvrijifiiia (f a Snr Sjirrii's (f ycnii'rtinc, Ann. and Man. "f Nat. I list. si-r. f), viil. xiv. Weldon, W. F. R. — An Attempt to Measure the Death-rate due to Selective Destruc- tion of Cairinus nifcnas, with Rcsjicct to a Particular Diuicnsion, Proc. Ro}'. Soc. Ivii. p. 300. REPORT OF THE COUNCIL. 85 Donations and Receipts. The Eeceipts for the past year include the annual grants from H.M. Treasury (£1000) and the Worshipful Company of Fishmongers (£400) ; and a special donation of £250 from Mr. J. P. Thomasson for the prosecution of fishery investigation. Other sources of income have been — the annual subscriptions (£135), composition fees (£25), rent of tables in the Laboratory (£39), sale of specimens (£205), and admission to the Aquarium (£GG) ; the total amounting, with lesser sums, to £2178. Vice-Presidents, Officers, and Council. The following is the list of gentlemen proposed by the Council for election for the year 1895-96 : — President. Prof. E. Ray Lankester, LL.D., F.R.S. Vice-Presidents. The Duke of Argyll, K.G. K.T., F.R.S. The Duke of Abercorn, K.G., C.B. The Earl of St. Germans. The Earl of Morley. The Earl of DuciE, F.R.S. Lord Revelstoke. The Right Hon. Lord Tweedjiouth. Lord Walsixgham, F.R.S. The Right Hon. A. J. Balfour, M.P., F.R.S. The Right JoSEl'H ChAMBER- Hon. LAIN, M.P. The Riglit Hon. Sir John Lubbock, Bart, M.P., F.R.S. Prof. G. J. Allman, F.R.S. Sir Edward Birkbeck, Bart., M.P. Sir Wm. Flower, K.C.B., F.R.S. A. C. L. G. GiJNTHER, Esq., F.R.S. Prof. Alfred Newton, F.R.S. Rev. Canon Norman, D.C.L., F.R.S. Sir Henry Thompson. Admiral Wharton, R.N., F.R.S. Elected Members. F. E. Beddard, Esc|., F.R.S. Prof. F. Jeffery Bell, F.Z.S. G. C. Bourne, Esq., F.L.S. Sir John Evans, K.C.B., Treas. R.S. G. Herbert Fowler, Esq. S. F. Harmer, Esq. Prof. W. A. Herdman, F.R.S. Prof. S. J. HicKSON, F.R.S. J. J. Lister, Esq. Prof. W. C. McLntosh, F.R.S. P. L. Sclater, Esq., F.R.S., Sec. Z.S. D. H. Scott, Esci., F.R.S. Prof. Charles Stewart, V.P.L.S. Prof. W. F. R. Weldon, F.R.S. Hon. Treasurer : E. L. Beckwith, F.s(|. Jfun. Sevretarij : E. J. Allen, Esq., The Laboratory, Plymouth. "^ (N O O O O O (N O 3 C O =! o o o o in o X) "o o re S3 jj ID . >I - j3 3 1^ O -H I 05 =<3 Ol o CL, tB Ah V CL, '-+< ^"3 o = w- 'WO OCSOQO Kl tJD cq S3 a C •'5 u c-t S ^t3 o «o C "O c ^ "^ CO a , 7^ S OJ o Oi >o c > r. =« "2 CO eco — -C CO (N ^ 5 "o a o o 1 = =^ CO Eh T3 .o; o 2 • III M CO ^ a a O rt ■S CO c/ "5-T3 C reasury . igers' Co lie year 1 ial Donat Ci- "K ■ S"^ g ■ 53 OJ from la in ham stipatio ;:;,<" CO S C oE^ 4> S ::; 1-2=2^1 aj a. CSC "im ll^o-S rt CS •— 1 r-, — •^^ X' c = a . a. . per annum. 1 1 0 ( 'omposition Pee. 15 15 0 ■ KtO 0 0 50(1 0 0 TERMS OF MEMBERSHIP. Annual Members Life Memberfi Founders C4(>\ernors iMcmlitns of till- Association have the following rights and privileges: they elect annually the OHicers and Council ; they receive the Journal of the Association free bv post ; they are admitted to view the Laboratory at Plymouth, and may introduce friends with tluin ; th. y liave the first claim to rent a placi- in the Laboratory for research, with use of tanks, bo«its, &e., and have access to the books in the Library !it Plymouth. All correspondence should In- addressed to the Director, The Laboratory, PI V mouth. -^ ; <^ - 1 New Series.— Vol. IV., No. 2— issued February, 1896.] [Price 3s. 6d. //,/;/ 3^otirnal OF THE MARINE BIOLOGICAL ASSOCIATION OP THE UNITED KINGDOM. THE PLYMOUTH LABORATORY. A PLYMOUTH: ruiXTED FOR TIIK .MARINE DIOLOGICAL ASSOCIATION UY W. DUUNDO.N" & SUN", AND PUBLISHED HY THE ASSOCIATION AT ITS OFFICES ON THE CITADEL HILL, SENT FItEE BY POST TO ALL MEMBERS OF THE MARINE BIOLOGICAL ASSOCIATION : ANNUAL SUBSCRIPTION FOll MEMBERSHIP, ONE GUINF.A. Agents in London :— Messrs. Dulau & Co., 37, Soho Square, W. PATRON. H.R.H. THE PRINCE OF WALES, K.O., F.R.S. OFFICERS AND COUNCIL. President. Prof. E. Ray Laxkester, LL.D., F.R.S. The Duke of Argyll, K.G., K.T., F.R.S. The Duke of Abercorn, K.G., C.B. Tlie Earl of St. Germans. Tlie Earl of Morley. Tlie Earl of DuciE, F.R.S. Lord R?:velstoke. Till' Right Hon. Lord Tweedmouth. Lord Walsixgham, F.R.S. The Right Hon. A. J. Balfour, M.P., F.R.S. Vice-Presideuts. The Right Hon. J(j.sei'H Chamber- lain, M.P. The Right Hon. Sir .John Lubbock, Bart., .M.P., F.R.S. Prof. G. J. Allman, F.R.S. Sir Edward Birkbeck, Bart., M.P. Sir Wm. Flower, K.C.B., F.R.S. A. C. L. GiJNTHBR, Es.|., F.R.S. Prof. Alfred Newton, F.R.S. Rev. Canon Norman, D.C.L., F.R.S. Sir Henry Thompson. Admiral Wharton, R.N., F.R.S. F. E. Beddard, Es(j., F.R.S. Prof. F. Jeffrey Bell, F.Z.S. a. C. Bourne, Esq., F.L.S. Sir John Evans, K.C.B., Treas. R.S. G. Herbert Fowler, E-sq. S. F. Harmer, Esq. Prof. AV. A. Herdman, F.R.S. COUNCIL. Elected Members. Prof. S. J. HiCKSON, F.R.S. J. J. Lister, E.sq. Prof. W. C. McIntosh, F.R.S. P. L. Sclater, Esq., F.R.S., Sec. Z.S. D. H. Scott, Esq., F.R.S. Prof. Charles Stewart, V.P.L.S. Prof. W. F. R. Weldon, F.R.S. Robert Bayly, Esq. The Prime Warden of the Fish- mongers' Company E. L. Beckwith, Es(|. (Fishmonger.'*' (Jonij[)any) Governors. Prof. BuRDON Sanderson, F.R.S. (Oxford University). Prof. Michael Foster, F.R.S. (Cam- bridge University). Sir Wm. Flower, K.C.B. F.R.S. (Brit. Assoc, for Advancement of Science). Han. Treasurer. E. L. Beckwith, Esq., The Knoll, Easthourue. Hon. Secretarij. E. J. Allen, E.sq., The Laboratory, Citadel Hill, Plymouth. PERMANENT STAFF. Director — E. J. Allen, Escj , B.Sc. Xaturalists. J. T. Cunningham, E.-^q., M.A. | F. B. Stead, Esq., B.A Assistant to tlie Director — T. V. Hodgson, Est^. VACATION COURSES IN MARINE BIOLOGY. By akrangement with the Director of tub Plymouth Laboratory of the iiltarinc JJiolocjicnl glssoctatton, ME. WALTER GAESTANG, M.A., F.Z.S., Fellow and Lecturer of Lincoln College, Oxford, and formerly Naturalist to the Marine Biological Association, WILL CONDUCT cotje,s:h]s OIF STTJx^'y IN MAKINE BIOLOGY, At the PLYMOUTH LABORATORY, DURING THE EASTER VACATION, 1896, Between March 23rd and April 24th. Students and others who may desire to avail themselves of the opportunities that will thus be afforded for a practical study of the life and habits of marine organisms, and of the methods employed for their capture and preservation, should communicate in advance with MR. GARSTANG, Lincoln College, Oxford, who will give any further information that may be required. Courses of Study similar to the above in will be conducted at the same time by Mii. A. H. CHURCH, B.A., Jesus College, Oxford, from whom further particulars may be obtained. [ 87 ] AUG 1895 The Reproductive Maturity of the Common Eel. By J. T. Cunningham, M.A. In the Museum of the Eoyal College of Surgeons, in London, there are two specimens of the common eel, in which the ovaries are much enlarged, greatly distending the abdomen, and evidently very nearly ripe. Both those specimens were presented by Mr. Geo. Buckeridge, a salesman in Billingsgate Market, who deals largely in eels. The following are certain particulars concerning the specimens : — (1) Length 15 in., weight 4J oz. Presented Jan. 4, 1894. (2) Length 19 in., girth round the abdomen 5|in., weight 10^ oz. Presented Sept. 25, 1895. Both specimens are in spirit, mounted for exhibition, and the ovaries are seen to be of opaque milk-white colour, and generally to present the same appearance as the nearly-ripe ovaries of the Conger described by me in Vol. IL of this Journal. The greatest width of the ovaries is 1^ in. or 4'8 cm. The eggs are scarcely visible as distinct grains to the naked eye. Microscopically examined in a small piece which Professor Stewart kindly gave me from the larger specimen, the largest eggs were found to be from "13 to '16 mm. in diameter, while the smallest were only "07 mm. It is a remarkable fact that eggs considerably larger than this have been found in the unripe ovaries of eels in the ordinary condition. Mr. Williamson (Thirtcetith Anmial Rep. of Scottish Fishery Board, 1895) states that in a specimen 707 cm. long (28iin.), some of the eggs measured '27 mm., and several other observers have given the maximum size as '25 mm. In the ripe specimen described by Eathke, in 1850, the eggs were also small, not exceeding *2 mm. In the specimen here under description, the microscope showed that the ovarian lamellae were composed almost entirely of ova in close apposition, the adipose tissue so plentiful in the ordinary condition of the ovary having been absorbed. It should be remembered that the eggs were measured after preservation in spirit, which must have caused contraction ; but Eathke, who examined his specimen when it was fresh, also remarks that the eggs were distinctly smaller than in eels with small ovaries. NKW .SEKIKS. — VOL. IV. NO. 2. H 88 THE REPRODUCTIVE MATURITY OF THE COMMON EEL. Fig. 1 represents accurately the appearance of the second specimen when mounted, the abdomen having been opened in the mid-ventral line. The figure is printed from a block prepared for the Field, and lent to me by the kindness of W. B. Tegetmeier, Esq. The time of year at which these specimens were obtained agrees with the conclusion drawn from other evidence, that eels spawn in autumn or winter, and serves to determine the actual fact that some eels are on the point of spawning at the end of September and beginning of January. The equally important question of the place of their capture has next to be considered. Mr. Buckeridge, who very kindly answered the enquiries I made to him on the matter, told me that both specimens were found among consignments of eels from Toom Bridge, in Ireland. Now Toom Bridge is at the point where the river Bann leaves Lough Neagh, and is about 26 geographical miles from the sea. It is certainly an extraordinary fact that an eel so near the ripe condition should be found in fresh-water. We can only suppose that the case is exceptional. There is a possibility that the specimen had been kept in captivity for some time after being caught, and that thus its ovaries had had time to develop. But, on the other hand, when eels have been kept in salt- water aquaria, as they have been at the Plymouth Laboratory, in order that ripe specimens might be obtained, the ovaries have not developed to any obvious degree. liathke's specimen is described in Mutter's Archiv. fiir Anat. Physiol. &c. 1850. It was brought to him, presumably in Berlin, by a fisherman on May 24th. It was dead, but in fresh condition. Nothing is stated concerning its place of capture. The ovary was 1| in. wide in its middle part. The fat, which in ordinary eels is abundant between the eggs, was almost entirely absent. The importance of the condition of this specimen to Eathke's mind was the evidence it supplied that the eel was oviparous, and not viviparous. It would appear that in addition to Eathke's specimen and the two here described, only one other nearly ripe female eel has been recorded. This fourth specimen is that mentioned by Calderwood, in a note in the Ann. and Mag. Nat. Hist. (6), vol. xii. 1893. But the description given is very scanty. The specimen was 29 i in. long, and was captured on December 27, 12 miles south of the Eddystone Lighthouse, or 20 miles from Eame Head, the nearest point of land. The width of the ovary and the size of the eggs are not mentioned. All that is stated is that the ovaries corresponded exactly in appearance with those figured and described by Brock in 1881, but Brock did not mention a ripe specimen. The ova are said to have been apparently ready to drop from the surface of the ovary, and to have been richly stored with oil globules. c 3 01 OB a 0 a OQ o o •a a (iC -3 > o [ 90 ] Preliminary Note on Trawling Experiments in certain Bays on the South Coast of Devon. By F. B. Stead, B.A,, Scholar of King's College, Cambridge, Assistant Naturalist on the Staff of the Marine Biological Association. The following pages are intended to be preliminary to a fuller report which I shall hope to publish later on. For the present I shall confine myself to an account of the objects in view of which these investigations were begun, and of the method by which they have so far been carried out. I further propose to append a brief summary of some of the facts ascertained, reserving a more detailed statement for a future occasion. The expectations with which the work was begun were twofold. It was hoped that by carrying out systematic experiments at fairly regular intervals, in certain well-defined areas within territorial limits, the characters of the populations of fishes of different species inhabiting these areas might be ascertained ; and, further, that by selecting, for the purposes of the investigation, certain bays at present closed to trawlers, in accordance with a bye-law of the Devon Sea Fisheries Committee, the effects of a discontinuance of trawling within these areas might be experimentally tested. This last expectation has, however, been disappointed, owing to the frequent infringement of the bye-law in question.* The scientific issues of an investigation of this kind will become clearer as time goes on : its practical bearings were sufllciently obvious at the outset. For clearly it will afford evidence of a valuable kind in connection with any question that may be raised as to the advisability, or otherwise, of closing the bays investigated. Investigations of a somewhat similar nature have already been carried out by the scientific staff of the Scotch Fishery Board for the east coast of Scotland, and by Holt for the west coast of Ireland. A * To what extent such illegal fishing has gone on, I am not in the position to say. But that it would be impossible to draw scientific conclusions as to the effect of closing the bays when the bays have not, in fact, been closed, is suflficiently obvious. IN CERTAIN BAYS ON THE COAST OF DEVON. 91 comparison of the results obtained by me with those obtained for the above-mentioned districts, will be held over until my own results are more complete. But I may perhaj)s take occasion to point out that my object is not so much to arrive at conclusions, as to the general distribu- tion of fish of different species and of different sizes, as to acquire a more exact knowledge of the changes which take place in the populations inhabiting particular areas. The areas selected in the first instance were Start Bay, Tor Bay, and Teignmouth Bay ; and the 24-ton smack Thistle, of Brixham, carrying a trawl with a 40 ft. beam, was hired by the Association for the purposes of the investigation. I desire to take this opportunity of thanking the skipper and crew of this vessel for the willingness they showed in carrying out my wishes. At the same time, it may not be superfluous to point out that in undertakiug work of this kind the Association is very seriously hampered by the want of a suitable steamer. Much time is necessarily lost on a sailing-vessel, even under favourable condi- tions, and calm weather may stop work entirely. Further, the necessity of making special arrangements as to hiring, and the delay that this entails, renders it impossible to make use of short spells of favourable weather. Moreover, the lack of accommodation on board a small smack puts any but the most cursory examination of specimens while on board entirely out of the question. In fact, it is not too much to say that the work might have been done with half the expenditure of time, and with far greater completeness, if the Association had had a steamer of its own. So far, I have made two separate trips to the above-mentioned bays. On each occasion I was accompanied by the Association's fisherman, H. Eoach. The first of these trips lasted five days, from October 28th to November 1st; on the second, bad weather rendered all further work impossible at the end of the third day — December 4th. The mode of procedure was as follows : — The times of shooting and hauling the trawl, the direction of the wind, the set of the tide, the depths in fathoms and the exact position of the vessel at the beginning and end of a shot, were all recorded. Notes were made of the "rubbish" that was brought up in the trawl ; and, lastly, all the food-fish caught were measured to the nearest quarter of an inch. The measurements were, in all cases, made from the end of the snout to the tip of the tail. Hauls were taken both by niglit and by day ; and my efforts were directed, on the first trip, to obtaining fair samples of the populations of the several bays, and, on the second, to conducting operations in such a way that the successive hauls obtained in December might fairly be compared with those obtained in the same bays a month before. 92 PRELIMINARY NOTE ON TRAWLING EXPERIMENTS It is not, of course, pretended that the same conditions, with the single exception of the difference in time, prevailed for corresponding hauls in two trips. When the physical circumstances are so complex and so variable, no such identity of conditions can be realised ; and, in the absence of a scientific theory of trawling, it is quite impossible to appreciate, except in the roughest manner, in what way an observed difference in the physical conditions may be expected to affect the catch. All I would venture to claim is that, so far as it is possible to do this on a sailing boat, the same ground was towed over on the second trip as on the first, and that, further, when the physical conditions were manifestly unfavourable, and the catch was, in consequence, small, the facts were recognised, and the value of the evidence afforded by the catch in question was duly discounted. Thus, in summing up the statistics so far obtained for Start Bay, I have omitted to include the measurements of the fishes caught in the first two hauls — when, owing to the light winds and calm weather that then prevailed, the catches were relatively small, and the practical experience of the skipper informed me that we had not had "a fair trial." Of the three bays selected for investigation, no adequate examina- tion of one — Tor Bay — has, as yet, been made. Two hauls were made in this bay on November 1st. On each occasion the net came up filled with sea-weed — which had drifted into the bay owing to the rough weather that then prevailed outside — and with little else. On the second trip, which was cut short by a change in the weather, no trial could be made in this bay ; nor has any opportunity since been given me of doing what was previously left undone. Before proceeding to state the results thus far obtained for Start and Teignmouth Bays, I may make mention of the fact that it was originally my intention to make a certain number of hauls in the deeper water of twenty fathoms and more, outside the limits within which trawling is forbidden. Once more my constant enemy, the weather, has pre- vented more than one such haul being made; but the results of this haul deserve to be recorded. The trawl was shot 3 J miles from Berry Head, which bore N.N.W., at 7.30 a.m., on December 3rd, at a depth of 21 fathoms, and was hauled at 11.30 a.m. from a depth of 18 fathoms — after being towed over a distance of about 3 miles in a straight line. The conditions as to wind, &c., under which the haul was taken, appeared to be favourable, and a remark to that effect was made to me by the skipper before the net was hauled. The total catch consisted of 157 whiting, whose middle length* was * By the "middle," or "mid" length, I mean the length on either side of which half the fish measured were found to lie. IN CERTAIN BAYS OX THE COAST OF DEVON. 93 10^ inches; 5d dabs, with a middle length of 9 inches; 18 pouting, all under 7 inches ; 7 grey gurnards, with a middle length of lOf inches; 1 tub, of Hi inches; 1 turbot, of 19 inches; and only 5 plaice, respectively 10|, Hi, 12, 12|, and 12^ inches in length. It will be seen that the quantity of saleable fish in this haul, which lasted four hours, under conditions apparently favourable, was extra- ordinarily small. Too much importance must not, of course, be attached to the results obtained by a single haul ; but I have given the facts as they stand, because, so far as they go, they tend to corroborate the statements again and again made to me by the fisher- men. For it is alleged by these men, firstly, that, at this time of; year, the fish are plentiful " in the bays " ; and, secondly, that they are present in relatively small numbers "outside," though good catches may be made by the large smacks which can venture far out to sea. It is this, then, that constitutes the grievance, of which one result is that trawling can scarcely be said to have entirely ceased in the nominally closed areas. It would be premature, in this preliminary report, to otter any opinion on the much-debated question of the wisdom, or otherwise, of the legislation now in force ; but it may perhaps be as well to point out that, assuming the statements above mentioned to be correct, they do not, in themselves, furnish an argu- ment against the closure of the bays. Setting aside, then, a consideration of the entire question till a future occasion, I may now pass on to a brief statement of the facts ascertained by trawling in the bays. In what follows no attempt is made to distinguish between the hauls taken on the first and those on the second trips ; still less between the individual hauls in the same bays on either occasion. All that I have done is to add together the numbers of each species of food -fish caught in all the hauls considered in each bay, giving, at the same time, the middle length in each case. The results are tabulated below : — START BAY (3 Hauls). TEIGNMOUTH BAY (4 Hauls) Total Number Caught. Mid Length. Total Number Caught. Mid Length. Plaice . . 559 12iin. 1088 lOi in. Dab 890 8| in. 511 71 in. Common Sole 35 11 in. 8 12| in. ]Merry Sole — 4 12 in. Turbot . 1 15^ in. 2 13 in. Brill 2 lljin. 2 11 in. Whiting . 144 10 j in. 61 G in. Pouting . 4 5 in. 40 6^- in. Cod 1 20.Un. Grey Gurnard 57 ll|in. 2 9iin. Tub 8 Ill in. * John Dory 11 11 in. — Herring . 1 9 in. — — 94 TRELIMINARY NOTE ON TRAWLING EXPERIMENTS An inspection of the above table will show that of the different species captured, plaice and dabs occurred in far the largest numbers. With regard to the relative numbers in which these two species were present in the bays, the table gives no certain information ; for the proportionate numbers of plaice to dabs in the several hauls varied very considerably, and the number of hauls made was too few to make it possible for any conclusion to be drawn. It should, however, be noted that of these two species the plaice are alone important from an economic point of view, since the large number of competing dabs ought probably to be regarded as a positive hindrance to the well-being of the plaice; and that, therefore, any discussion as to the merits or demerits of the present bye-law should be almost wholly occupied with the question whether the closure of the bays to trawlers is necessary for the "protection of the plaice. It will further be observed that the plaice in the two bays differed from one another in respect of size ; that while half the plaice caught in Start Bay were under \2\ inches, in Teignmouth Bay the mid-length was only 10 1 inches. A similar difference obtains in the case of the dabs, whose mid-length was 8| inches in Start Bay, and 7A inches in Teignmouth Bay. These differences are of considerable importance ; they appeared in a marked manner in all the hauls taken on either trip, and they imply a striking difference in character between the two bays. Of these differences two explanations alone appear to me to be possible. They may be due in each case (1) to a difference in the ages of the fish caught in the two bays; (2) to a difference in their rate of growth.* As for the first of these explanations, it is difficult to see why there should be a larger proportion of older fish in Start Bay than in Teignmouth Bay ; and with regard to the second, I am unable to point to any causes to which a difference in the rate of growth might be ascribed. Whichever explanation is adopted, a striking difference between the two bays, in respect of the most im- portant fish they contain, appears to be indicated — a difference which is the more remarkable in that the bays in question are not more than 15 miles apart, and open into the same sea. Whether such a difference is constant throughout the year I am not yet in a position to say ; but that it held good from October to December of this year there is no reason to doubt. Further, though it would be out of place in this preliminary paper to enter into further details, I may, perhaps, add that while the differences in the mid-lengths of plaice and dabs for • The possible influence of diO'erenccs in the depths at which hauls were taken in the two bays has not been overlooked ; but a comparison of the soundings taken does not appear to favour such an exi)lanatiou of the dilTereuces between their respective populations. IN CERTAIN BAYS ON THE COAST OF DEVON. 95 these bays are the most obvious, they are not the only difTerences which appear, when the statistics are examined. The general im- pression which such an examination has so far given me is that each bay has a certain individuality of its own in respect of the populations it contains. While plaice and dabs appeared in every haul in considerable numbers, the other species captured were obtained in relatively small numbers, and, in most cases, not in every haul. Thus the 144 whiting recorded for Start Bay were all obtained in the two hauls made in that bay on December 4th ; while of the 57 grey gurnards, 29 were obtained on the first trip, and 28 on the second ; and of the 35 soles, 33 were taken in the first haul made in Start Bay, and only two in the two last hauls. Hence, for the present, at least, in attempting any comparison of the population of the bays examined, little account can be taken of the species captured other than plaice and dabs. A careful comparison of the corresponding hauls in each bay has led me to believe that the attempt to obtain a fair idea of what a vessel provided with a similar net might be expected on the average to catch, was attended with success. And if we were only concerned with the practical and economic side of this investigation, this is all we should have to consider. As it is, the further question arises. How far do the catches so obtained represent the actual populations of the bays ? It must be admitted at once that the results are incovijjleie, since they do not apply to the shallower portions of these bays, with depths of less than 5 fathoms. I intend, therefore, to supplement the facts ascertained by trawling, by an investigation into the catches of the inshore fishermen. It remains to consider to what extent the results are imperfect, for those portions of the bays to which they do apply. That the width of mesh of the net employed exerts some selective influence, in permitting the escape of small fish, seems tolerably certain. But in the case of the plaice, at least, there is good reason to think that this factor did not operate to any serious extent. Dr. Fulton's investigations* have shown that with an ordinary net of 1^-inch mesh from knot to knot, out of a total number of 1080 plaice under 8 inches, only 58 escaped (i.e. 5*3 per cent). In my own investigations, the total number of plaice captured under 8 inches in length is only 71. Unless, then, the proportion of the plaice that escaped was far larger in these experiments than in those carried on by the Garland, the selective influence of the net, in permitting the escape of small plaice, may be neglected. The same cannot, however, be said for dabs. For these fish, Fulton's • Twelfth Annual Report of Scotch Fishery Board, iii. p. 307. 96 TRAWLING EXPERIMENTS ON THE COAST OF DEVON. results show " that with an ordinary net of l|-inch mesh, the great majority of the specimens at or below 6 inches escape." It must further be remembered that other factors may come in — of which we know little or nothing — tending to create a discrepancy between the apparent results as ascertained by trawling, and the actual populations existing in the bays. But this fact, while it should make us cautious in drawing inferences from the former to the latter, does not invalidate any comparison we may institute between the results obtained under like conditions in the two bays. It would be unwise at this juncture to attempt in any way to forecast the results to which these investigations may lead us. But apart from the practical object in view of which they were begun, there are at least three subjects on which these experiments, if systematically carried on, ought to throw light : (1) the rate of growth of the more important fishes captured ; (2) the migrations which may take place from the areas in question for the purposes of spawning, or from other causes ; (3) the nature and influence of local conditions as affecting variations. To what extent it may be possible to attain these ends is uncertain ; but that the method of this investigation — consisting, as it does, in an attempt to study the characteristic features of particular localities — is a sound one, I have become more and more convinced as the time has gone on. [ 9T ] North Sea Investigations. {CONTINUED.) By J. T. Cunningham, M.A. PAGE I. The Size of mature Plaice, Turbot, and Brill, on different Fishing Grounds 97 II. Observations at Sea and in the Markets : — 1. Grimsby ..... 2. Scarborough ..... 3. Hull — The Adoption of the Otter Trawl in Steam Trawling 4. Lowestoft ..... III. Causes of the Observed Distribution of Fish in the North Sea , IV. Proposed Restrictions on the Landing of Undersized Plaice in the light of the New Evidence . . . . . .138 108 112 114 121 133 I. The Size of mature Plaice, Turbot, and Brill, on different Fishing Grounds. In the previous number of the Journal, I described my reasons for doubting whether the conclusions drawn by Mr. Holt, concerning the size at which plaice become mature, would hold good for the whole of the North Sea ; and also whether the evidence he relied upon, in distinguishing mature and immature plaice, was sufficient. I stated that, as an actual fact, one sample of mature plaice, which were much below the limits of size determined by Mr. Holt, had come into my hands. I suggested, as a probability, that the presence of dead degenerating eggs in the tissue of the ovary was a proof that the fish had spawned, was a spent, and therefore a mature specimen. My words were : " It cannot be asserted as a certainty that these granular masses never occur in an immature ovary ; to settle the doubt it will be necessary to make a careful examination of plaice in November and December, when all fish which are about to spawn will have a large amount of yolk in the eggs, and all fish in which the eggs are transparent and yolkless must be immature." It was already known that these degenerating eggs do occur in spent ovaries, from which the ripe eggs have recently been discharged, and which bear 98 NORTH SKA INVESTIGATIONS. evidence of the fact in their somewhat large size, flaccid and collapsed condition, and usually in the presence of a few detached ripe eggs in their interior. Observers were agreed that the explanation of this fact was that when spawning was finished, a certain number of eggs were still only partly developed, and that these, instead of completing their development, degenerated, and were gradually removed by absorption in their place without being discharged. It seemed natural to infer, therefore, that in every ovary in which microscopic examina- tion showed the presence of these degenerating eggs, spawning had previously occurred. This supposition has proved, however, to be incorrect. The granular opaque masses have been found in the ovaries of the plaice in every month of the year from February to December, and in November and December have been found to occur nearly always in ovaries, which showed no trace of the development of yolk in the healthy eggs, which were, therefore, undoubtedly immature, the mature ovaries at this time being much enlarged and far- advanced in development. At this time no fish had begun to spawn, and none were in the spent condition. It is clear, then, that aborted partially yolked eggs do occur in immature ovaries. In different specimens these aborted eggs are seen in different stages of degeneration, and it is evident that in an immature ovary a small number of eggs are constantly beginning to develop yolk, as though about to become ripe eggs, but almost immediately die and degenerate instead of continuing their development. The same process is going on in mature ovaries between the spawning seasons. When the fish becomes mature, then some months before the spawning season a large number of eggs continue to develop without check or interruption until the crop of ripe eggs is produced. The plaice which, on February 27 last, I found to be mature at sizes below Mr. Holt's limits, were said to have been caught off the Leman Shoal, at a depth of 12 to 17 fathoms. I do not feel sure that this was really their place of capture, for reasons which will appear in the sequel. But I have found that the plaice, taken by the Lowestoft trawlers in the neighbourhood of the Brown Badges, are certainly mature at sizes similar to those which characterise the sample mentioned, and considerably below Mr. Holt's limits. On October 2nd, I made a complete examination at Lowestoft of a box of plaice from the Brown liidges. As it was so considerable a time before the commence- ment of the spawning season, I did not attempt to distinguish between mature and immature males. But in many of the females yolk-forma- tion had distinctly commenced, or was even somewhat advanced, and these I put down as mature, the others as immature. The results are as shown in the following table : — NORTH SEA INVESTIGATIONS. 99 Box OF Plaice from Brown Ridges, October 2nd, 1895. Total number, 176. Length in inches. 9 10 11 12 13 14 15 16 17 18 19 Males. 1 6 25 27 10 2 Females. Mature. Immature l(9|iD.) ... 2 — 12 6 24 12 24 14 5 1 Totals. 4 18 55 63 29 3 71 38 176 67 (40-3 per cent.) (21-6 per cent.) (SS'l per cent.) On November 18, I examined another sample, sent from Lowestoft to me in London. The information given me, concerning the place of capture, was that it was on the track of the Harwich boats, nearer the Dutch than the English coast. This would be somewhere to the west of the Hook of Holland. The condition of these plaice was as shown in the following table : — Plaice from Lowestoft, November 18th, 1895. Total number, 197. Malrs. Females. Length in inches. Mature. Inimature. Mature. Immature. Totals 8 — 1 — — 1 9 6 9 — 4 19 10 .. 17 14 2 .. 21 54 11 .. 21 7 12 .. 27 67 12 .. 17 4 11 9 41 13 4 — 5 1 10 14 1 — 1 — 2 15 1 — — — 1 16 17 18 — — 1 — 1 — — 1 — 1 G7 35 33 62 (34 per cent.) (17'8 per cent.) (16"7 per cent.) (31 "5 per cent.) 197 It is possible that, in this last sample, some of the males set dov/n as immature would have become mature before the end of the spawning season, but this is not a question of great importance. In both samples 100 NORTH SEA INVESTIGATIONS, the limits of maturity and immaturity in the females agree with those seen in the sample examined at Grimsby : these limits are 9 in, and 14 in. Below 9 in. no females are mature, above 14 in. none immature. The limits at Plymouth were almost exactly the same, except that three specimens were found to be immature at 14 in. Mr. Holt's limits, on the other hand, were 13 in. and 18 in., so that there is a difference of 4 in. between both the upper and lower limits in the two cases. There is every reason to believe that the maximum size actually attained by the fish corresponds to the size at which it begins to spawn. As a matter of observation we find that the largest plaice caught in the neighbourhood of the Brown Eidges are considerably smaller than the largest caught on grounds further to the north. The largest plaice in the samples above described does not exceed 20 in. in length. The ground named extends between thirty and fifty miles from the Dutch Coast, and to a great distance in a north and south direction. It is limited by the " edge of the deep water " towards the English coast, and this boundary (the twenty fathom line) lies at about fifty-five miles from the coast of Norfolk. The ground is undulating, being traversed by ridges running north and south, over which the depth decreases to a minimum of 11 fathoms, while, in the valleys between, there is, in some places, a depth of 24 fathoms. The ground is therefore neither uniformly shallow, nor close to the land. I was strongly inclined to think that the small plaice of the German Bight would prove to be of the same character as those from the Brown Ridges. My theory was that the race of smaller plaice actually proved to exist off the coast of Holland would be found to extend along the Dutch and German coasts, probably as far as the Horn Keef, and that this would be the explanation of the small size of the plaice landed at Hull and Grimsby, from the German or Heligoland Bight. In order to examine samples of the plaice caught on these eastern grounds in November and December, I considered whether it would be advisable to go to the Biological Station of Heligoland, or to some fishing port on the German coast, or to have samples sent over the sea to me in London. I made enquiries from Dr. Heincke, the Director, and Dr. Ehrenbaum, the Zoologist of the Biological Station, and have much pleasure in here expressing my thanks for the courtesy and thorough efficiency with which they assisted me to obtain the facilities I required. They informed me that plaice were not landed in Heligoland regularly or in large numbers, but that they would assist me in my under- taking if I visited one of the fishing ports on the mainland. I thought, however, that, under the circumstances, I might just as well have samples sent to me in London, and accordingly Dr. Ehrenbaum put me in communication with Herr Diige, the harbour-master at Geestemiiude, NORTH SEA INVESTIGATIONS. 101 who undertook to forward me samples of plaice, with most careful atten- tion to all the precautions and conditions I required. The first sample reached me on November 20th, and the following table shows the result of their examination : — Plaice from Geestemunde, November 20th, 1895. Total number, 186. Males. Females, Id. Mature. Immature. Mature. Immature. Total. 10 — 5 — 2 7 11 2 43 1 35 81 12 7 27 ■ — - 36 70 13 1 3 — 17 21 14 — — — 2 2 15 — — — — — 16 1 — — — 1 17 1 — — — 1 18 — — 1 — • 1 19 — — — — — 20 — — 2 — 2 12 78 4 92 186 (6-5 per cent.) (41-9 per cent.) (2-1 per cent.) (49-5 per cent.) It will be seen, at once, what a striking contrast these fish present to those from the grounds south of the Texel. The single mature specimen at 11 in. is of no importance in comparison with the large numbers of immature. We may say that all below 15 in. were immature, so that they correspond very closely with the plaice examined by Mr. Holt, at Grimsby. Among the males there are a larger proportion mature at 12 and 13 in. than Mr. Holt found, but in the females there is no evidence of maturity at a smaller size than that fixed by him. We must conclude, then, that these fish are small because they are young and immature, not because they are of a smaller race. These fish were stated by Herr Diige to have been caught at 53° 58' north latitude and T 10' east longitude from Greenwich, a position about 15 miles north of the island of Nordeney, at a depth of 13 to 14 fathoms. In a letter which I received on December 5th, Herr Diige informed me that among the plaice landed at Geestemiinde, he found the smallest ripe males were 32 cm. long (12i in.), the smallest mature females 40 cm. (16 in.), an observation which agrees with the results of my examination of the German plaice in London. The above sample does not afford complete evidence concerning the range of size, or the proportional numbers at difl'erent sizes, of the plaice taken on the ground from which it came, because it consists, as Heir 102 NORTH SEA INVESTIGATIONS. Diige informed me, of the marketable fish selected from the whole number brought up by the trawl, the smaller being rejected. This, of course, makes no difference with regard to the minimum size of mature specimens; all those rejected less than 10 in. in length must have been immature. The smaller fish, which were thrown overboard, however, when the sample was taken, were stated to be very few in number, although Herr Diige tells me that it sometimes happens, even in winter, that, in the same locality, plaice mostly from 9 to 12 in. in length are taken. I was desirous of obtaining a sample sent, without selection, just as they came on deck, and Herr Diige was good enough to send me a second consignment. These fish were trawled on December 20th, in 54° 35' north latitude, 7° 40' east longitude, at a depth of 11 fathoms. This position is about 24 miles from the Amrum Light, and in the very same neighbourhood in which the steam trawler, John Bull, was fishing, in June, when I was on board her. The sizes and conditions of these fish are shewn below : — Plaice from Geestemijnde, December 20rH, 1895. Total number, 121. Males. Females In. Mature. Immature. Mature. Immature. Total. 9 — 1 — — 1 10 — 4 — 1 5 11 — 5 — 6 11 12 — 7 — 17 24 13 2 8 — 35 45 14 3 3 — 13 19 15 1 ... 1 7 9 16 — — — 4 4 17 — — 1 — 1 18 1 — — — 1 19 — — 1 — 1 6 29 3 83 (4"9 per cent.) (24 per cent.) (2-5 per cent.) (68-6 per cent.) 121 It will be seen that these unselected plaice were, on the whole, not smaller, but somewhat larger than those in the previous sample from German waters, and with the quite insignificant exception of the one specimen at 9 inches, did not include any smaller specimens. With regard to immaturity, the second sample agrees with the first, no less than 92'6 per cent, of the whole number being immature. In both samples the proportion of mature female specimens below 18 inches is even distinctly lower than in Mr. Holt's records taken at Grimsby. NORTH SEA INVESTIGATIONS. 103 A comparison between these plaice, caught off the German coast in November and December, and those which I have described in the previous number of the Journal, as caught under my own observation in June, in the same neighbourhood, is worthy of careful attention. Firstly, with regard to the locality of capture. The position given by Herr Diige, for the second sample, is 2-4 miles west of Amrum Light ; and in the cruise of the John Bull, the Amrum Light was seen, on two nights, at a distance of 20 miles. Thus, the John Bull was fishing on these occasions 4 miles nearer the land, and it is true that sometimes she was steered nearer the land than this ; but she was also fishing sometimes out of sight of the Amrum Light, and the ground she covered must have included the position where the December sample was taken. Next, with regard to the depth : during the fishing of the John Bull, it varied from 1\ to 12h fathoms, while the December sample was taken at 11 fathoms. At the seventh haul in the record of the trip of the John Bull the depth was 12 fathoms, and at this haul a number of plaice, 7J to 10 inches long, were taken, two baskets 10 to 12 inches long, and two baskets 12 to 15 inches long. The comparison shows, therefore, that although the John Bull extended her operations to positions nearer the land than that where the December sample was taken, yet it is clear that she also fished at the same depth and distance from land, and obtained there numbers of plaice of small sizes, which are not represented in that sample. On the other hand, the December sample includes specimens larger than any taken on the same ground in June, when the maximum was 1G| inches. It appears to me quite probable that these differences are due simply to the growth of the fish in the six months' interval. We must either conclude that the fish taken on the German grounds in early summer are of the same race as those taken in Decem- ber, and therefore, with the exception of a small minority, principally males, immature ; or we must suppose that they are fish of a smaller race which migrate to these grounds from some other, e.g., more southern region. This latter supposition is at present unsupported by any evidence, and I think we must seek to explain the facts on the view that the summer and winter fish are of the same race. This is not difficult, if we suppose that the smaller fish — 6 to 10 inches long — are the year-old fish, which move out from the shallow inshore waters on to those grounds at the beginning of their second summer. The larger immature fish, broadly speaking, from 10 to 15 inches long, must be two-year-old fish, while the number of mature fish over three years is in small proportion. The dispersal of the year-old fish to greater distances from land, and their gradual increase in size, would account for the fact that the fish on the Eastern Grounds become NEW SERIES.— VOL. IV. NO. 2. ■ I 104 NORTH SEA INVESTIGAIIOXS. both much less numerous, and generally larger in late summer and autumn. I have found that the condition of the plaice along the English coasts of Norfolk and Suffolk is not the same as along the opposite Dutch coast. It would appear that the Channel conditions extend northwards along the Dutch coast, while the size of the mature plaice, which is characteristic of more northern grounds, extends southwards to some distance alone: the English coast. Some of the Lowestoft smacks were fishing in October, near the Leman Shoal, and on neighbouring grounds, and were landing plaice considerably larger than those from the Brown Eidges. I examined a box of these large plaice on October 4th, in the same week in which I examined the sample from the Brown Eidges. The results were as follows : — Plaice from Leman Shoal, October 4th, Total number, 115. Females. 1895. Length in inches. Males. Mature. Iniiiiature. Totals 9 • • 1 — — 1 10 5 . . 4 9 11 15 — 6 21 12 6 l(12§in.)... 9 16 13 14 — 7 21 14 7 5 5 17 15 4 8 1 13 16 — 6 2 8 17 — 5 — 5 18 — 3 — 3 19 — — — — 20 — — — — 25 — 1 — 1 52 29 34 (45-2 per cent.) (25'2 per cent.) (29'6 per cent.) 115 The Leman Shoal is somewhat further north than the Brown Eidges, being in the same latitude as the island of Texel, and the depth in its neighbourhood does not exceed 20 fathoms. The contrast between these plaice and those from the Brown Eidges is very marked. It will be seen that the proportion of mature females among the former is not much greater, 25-2 per cent., as compared with 21-5 per cent, of those from the Ikown Eidges. If we take the females separately, the proportion of mature individuals among these is certainly higher in the sample from the Leman Shoal, i.e. the sample of larger fish : it is 4G per cent, among these, o6'l per cent, among the fish from the Brown Eidges. But this is not a very great difference, and appears to be due chietly to the fact NORTH SEA INVESTIGATIONS. 105 that, in the one sample, there were more males and fewer immature females than in the other. The general difference in size in the two samples is sufficiently obvious from the fact that one box contained 176 fish, the other only 115, the box in both cases being of the same size. If we compare the limiting sizes of the mature and immature, they are 9 in. and 14 in. in the case of the smaller, 12 in. and 17 in. in that of the larger, a difference of 3 in. By limiting sizes, I mean the smallest mature and largest immature. Thus the relation of size to maturity in the Leman Shoal plaice agrees closely with that observed by Mr. Holt at Grimsby. I have endeavoured to obtain samples of plaice from the English side, further south than the Leman Shoal. Opposite the coasts of Norfolk and Suffolk there is a depression of the sea-bottom, ranging from 20 to 27 fathoms in depth, its eastern boundary being about midway between the English and Dutch coasts. I tried to obtain a sample taken in this deep water. The box that was sent to me from Lowestoft, in response to a request to this effect, was stated to have been taken 40 to 45 miles E.S.E. of Lowestoft, a position which would be near the eastern limit of the deep water. The fish proved, on examination, to be much more immature than the samples from more eastern grounds already described, although, if the place of capture is correctly reported, it is only about 20 miles further from the Dutch coast than the Brown Eidges, where the smaller fish were taken. The sizes and condition were as here shown. Plaice caught 40 to 45 miles E.S.E. of Lowestoft, Deo. 23rd, 1895. Total number, 132. Ma les. Females. In. Mature. Immature. Mature. Immature. Totals. 9 — 1 — 2 3 10 — 9 — 7 16 11 9 9 — 9 27 12 8 5 1 23 37 13 6 4 1 14 25 14 — 1 — 7 8 15 2 — 1 1 4 16 5 — 2 — 7 17 — — 3 — 3 18 — — 2 — 2 30 29 10 63 (227 per cent.) (22 percent.) (75 per cent.) (478 per cent.) 132 This sample is intermediate in its limiting sizes between the Dutch plaice and the more northern plaice, the limits being 12 in. and 16 in. for females. I 2 106 NOKTII SEA INVESTIGATIONS. In order to make a direct comparison between the samples already mentioned with one from more northern grounds, I obtained a box from Billingsgate. Mr. liichard Vivian, agent of the Hull Steam Fishing and Ice Co., kindly undertook to send me a box, with reliable information concerning the ground on which the fish were taken, and was in a posi- tion to obtain this information from the master of the steam carrier which l)rought the fish from the fishing fleet to London. Accordingly I received, on December Gth, a box of plaice which had been trawled on the south side of the Dogger Bank, in 55° 20' north latitude, 4° 30' east longitude, at a depth of 24 fathoms. The following is the record of the sizes and condition in this sample : — Plaice from South Side of ;N"orth-Eastern Portion of the Dogger Bank, 24 Fathoms, December 6th, 1895. Total number, 68. M ales. Females. In. 10 Mature. Iiiimature. 4 Mature. Innnature. 2 Totals. 6 11 — 4 — 8 12 12 1 3 — 2 6 13 — 7 — 3 10 14 2 1 — 6 9 15 3 1 — 4 8 16 9 — 1 1 11 17 1 — 1 1 3 18 — — — — — 20 — — — — — 21 — — 2 — 2 23 — • — 1 — 1 16 20 5 27 (235 per cent.) (29"4 per cent.) (7"4 per cent.) (39"7 per cent.) 68 The upper limit of the immature here is as high as in Mr. Holt's results; the lower limit of the mature is unusually high. The reason of the latter fact is to be found in the small number of specimens at each size in the sample. Mr. Vivian informed me that the plaice were packed in two sets, some boxes containing only large fish, others containing mixed sizes. My sample was one of the latter. We cannot, therefore, look upon this sample as representing the general condition of the plaice caught on the ground from which it came, but it is important to notice that considerable numbers of plaice from 10 in. to 13 in. long, and quite immature, are caught right in the middle of the North Sea, about 150 miles from the coast either on the east or west. NORTH SEA INVESTIGATIONS. 107 The sizes and conditions of the turbot and brill which I examined in May and June last year, are shown in the two tables here given. Most of them were examined on board the two trawlers on which I made the two voyages described in the previous number of the Journal ; but in addition are included 20 brill from the same grounds, which I examined on shore. Some smaller specimens, which were only 8 and 9 in. long, were measured, but their sex not ascertained. Turbot on the German Grounds, South of Horn Eeef, and off Amrum, 7 to 15 Fathoms, May and June, 1895. Males. Females. In. Mature. Iiuiiiature. Mature. Immature. 11 1 — — 1 12 1 — — 2 13 14 — — 2 14 10 — 1 5 15 1 — — 4 16 17 18 2 — — — — — — — 19 3 — • • • "*"*■ • • • **""* 20 4 — 1 — 21 1 — — • • • ~^~ 22 — — 2 — 23 — — • • • "' — 24 — — 2 — 25 — — 1 — 26 — — — — 27 — — 1 — 28 — — 1 — 29 — — 3 — 30 — • • • ' — — 31 — — 1 • • • ^— ^ Brill on the German Grounds, South of Horn Reef, and off Amrum, 7 TO 15 Fathoms, May and June, 1895. Males. FcmQlp.s In. Mature. Immature. Mature. Immature. 10 4 ... — — ■ 2 11 3 ... 5? — 16 12 1 ... 2? — 23 13 — • . . — 1 8 14 1 . » . — 1 3 15 — . . . — 2 — 16 1 . . . — 1 — 17 1 ... — 3 — 18 — ... — 1 — 19 — ... — — — 20 — ... — 1 — 108 ' NORTH SEA INVESTIGATIONS. II. — Observations at Sea and in the Markets. 1. Griinshj. At Grimsby there are a number of trawlers — some steamers and some sailing vessels, which are locally called Cleethorpers, and regularly fish on the grounds near the Humber, returning to port at the end of the week. I went out in one of these, the s.s. Rhine, on July 22nd. My object was to examine the grounds near the mouth of the Humber and the Wash, in order to compare them with the grounds off the German coast. We shot the trawl at 2 p.m. the same day, having steamed 55 miles by the log from the Newsand Lightship, at a position a few miles west of the Coal Pit or N.E. Hole, as it is named on the chart illustrating Mr. Holt's description of the Grimsby Trawl Fishery. The depth during the haul was 13 to 18 fathoms. The temperature at the surface was 58° F. The trawl was hauled up at 7.15 p.m. The scruff was plentiful, and consisted of Hydroids, chiefly Scriularia and Hydrallmania. Alcyonidium, called by the fishermen " curly cabbage," was also extremely abundant. Another Polyzoan, namely Crista, was plentiful, and there were many Solaster pajyposus. The quantity of marketable fish was very small. The smallest plaice was 8f in. long, and there were 7 from this size to lOJin, ; these were thrown overboard. Some lemon soles 8| to 9Hn., a few haddock of 8Hn., and some small dabs 6^ in., were also rejected. The fish packed away were : — 1 basket plaice, ^ basket haddock, ^ basket lemon soles and whiting, ^ basket dabs, with a few codling, 4 soles. There were also 10 roker, or rays, and 1 lobster, 10 in. long. The next haul we steered N., down the Coal Pit, and sounded 22^ fathoms. The trawl was hauled at 11.30 p.m. The scruff again was very abundant, consisting chiefly of the Alcyonidium; Hydroids also were very plentiful. There were present also Alcyonium, com- pound Ascidians, and Solaster papposus. Among the Hydroids were large clusters of Antennularia antennina. The smallest plaice was 8J in. long; smallest haddock 7f in. ; smallest whiting 8|in. ; smallest lemon sole 72 in., a female, immature. There were 1 solenette 3| in., a mature female, and 2 others ; 1 latchet, a small specimen ; 1 scad {Caratix trachurus), 1 cod, and 2 rays. The other marketable fish were : — f basket plaice, \ basket haddock, I basket dabs, ^ basket lemon soles and whiting. Third haul, also in Coal Pit, 11.45 p.m. to 5.0 a.m. on Tuesday. As before, a large quantity of scruff and a small quantity of fish. Besides the other items seen in the scruff before, there were several NORTH SEA INVESTIGATIONS. 109 sea-urchins {Echinus miliaris). Of the fish, a basketful of small haddock, whiting, and dabs, and a few small gurnard, were thrown overboard ; the small haddock measured 6f to 8^ in., there being only 2 or 3 of marketable size. The smallest dab was 5 in., a male, the largest 14i in., a female. The smallest plaice was 7i in., a female, the largest 20 i in., but only 2 were small enough to be thrown over- board. The marketable fish were: — 1 basket plaice, \ basket dabs, 6 rays, and 4 lemon soles. Fourth haul, in the Sole Pit which lies to the N.W. of the Coal Pit, and has a maximum depth of 43 fathoms. We sounded 40 fathoms once, and afterwards 13i fathoms. The trawl was hauled at 8.30 a.m. There was less scruff than before, but Alajoniitm, or " teats," were very plentiful in it. Only a small quantity of fish. The smallest plaice was 10 in., an immature female ; there were altogether 28 females, the largest 2H in. ; 19 males, the largest 20iin. There were a few lemon soles, haddock, roker, cod, grey gurnard, and dabs. Up to this time we had not taken a turbot or brill. Fifth haul, 11.30 a.m., June 23rd, to 4.30 p.m., along the east side of the Sole Pit. Scruff as usual, with the addition of whelk-spawn and Flustra, sometimes known to the fishermen as " scented weed." The smallest plaice was 9^ in., and only one thrown over: largest 21^ in. Some small haddocks 8i in. Smallest lemon sole 8J in. The fish thrown away were \ basketful of small haddocks, whiting, gurnards, dabs, the haddocks up to 10| in., dabs up to 9| in., and all the grey gurnard. The fish kept were 1^ baskets plaice, 1 basket kit haddock, \ basket dabs and codlings, \ basket whiting and lemon soles, 3 small roker {Raia clavata), and 2 turbot, one 22 in. male, ripe ; one 2 ft, li in. female, not ripe. Fifteen more hauls were made in or close to the Sole Pit with varying fortune, but several of them were failures, in consequence of the trawl catching fast and the net being torn. The ground in this part is rough, and necessitates short hauls and much net mending. The scruff was always abundant and of much the same composition. I made a careful examination of all the waste fish from one haul. The marketable fish from this haul was : — 1 basket plaice, li baskets kit haddock, i basket dabs and codling, h basket lemon soles and whiting, 14 soles, 2 cod, 1 crab, 12 small rays. The waste fish filled nearly a basket, and comprised : — 220 dabs, 3^ in. to 10 in. long; 86 haddock, 7 in. to 11 in. long, measured to the end of the middle ray of the tail ; 46 grey gurnard, 0^ in. to 11^ in. long; 11 codling, 5| in. to lOi in. long; 3 whiting, 9^ in. to 10 in. ; 8 plaice, 8^ in. to lOin. ; 7 lemon soles, 7 in. to 10 in., the smallest a ripe male; 3 scad, 11^ in. to 12|in. ; 1 bib {Gadus luscus), 6| in. ; 110 NORTH SEA INVESTIGATIONS. 2 solenettes ; 3 Trachunis vipcra, the lesser weever ; 2 thornback rays, 8 in. to 0^ in. across pectorals ; 1 long rough dab, 9 in. long. Plaice up to 24 in. and 2G in. in length occurred in these hauls, and as in the above instance only an insignificant number under 10 in., which were thrown overboard. After this a haul was made 7 or 8 miles to the east of the Dowsing Lightship, at a depth of 9 to 11 fathoms. The marketable fish caught were: — 1^ baskets plaice, 1^ baskets lemon soles, codling, and haddock mixed ; 2 rays, 2 brill 23| in. long. The largest plaice was 24 in., and 4 plaice of 9 in. were thrown overboard. There was an extraordinary quantity of Alcyonidmm, or "curly cabbage," about 1-^ basketfuls, the scruff consisting almost entirely of this. One horse mussel {Mytihts modiolus), and 2 sunstars were seen. At the next haul the trawl was down G hours, from 9 p.m., July 26th, to 3 a.m., July 27th. A still greater quantity of Alcyoni- dium, was brought up — 3 or 4 basketfuls. The fish were : — 2 baskets plaice, f basket kit haddock, | basket lemon soles and whiting, | basket dabs and codling, 14 soles, largest ISi-in., smallest 7in. ; 2 cod, 1 ray, 8 crabs. A basket of plaice is rather more than half a boxful, as the boxes are packed for sale, and the number in a basketful may therefore be estimated at about 50 fish. Only two short hauls of no importance were made after this on the same ground, and then we returned to Grimsby. It will be seen that the grounds visited in this voyage were all too far from the English coast to be considered as corresponding to the grounds visited in the s.s. John Bull. The nearest of them is the Outer Dowsing Ground ; the Outer Dowsing Light is 30 miles from the nearest coast, and we fished on the farther side of the Lightship. The depth off the Dowsing was scarcely greater than off the Island of Amrum. "We sounded 11 fathoms, and, doubtless, trawled in shallower water than that. The other grounds are narrow gullies, surrounded by fairly level ground less than 20 fathoms in depth. In the character of the bottom, these grounds differ very greatly from those visited in both my voyages on the German side. The latter were nearly all sandy, and very little scruff was brought up: pieces of Flustra foliacea, and truncata, and Hydrallmania were entangled in the net, but the total bulk was inconsiderable. On the English Grounds, on the contrary, the quantity of scruff was enormous, and indicates a coarse varied ground of stones and shells. With regard to the character of the fish, the grounds above described resemble those to the south of the Horn Ileef Lights, a voyage to which NORTH SEA INVESTIGATIONS. Ill was described by me in the previous number. That ground was farther seaward than the ground where the small plaice were taken ; it was mostly from 24 to 30 miles from Blaavand Point, the nearest land, and the depth 11 to 15 fathoms. The plaice were in both voyages mostly between 12 and 26 inches in length, although about twice as abundant on the German side. The haddock, too, were abundant at the Horn Eeef, scarce in the voyage of the Rhine, and most other kinds of fish were more abundant on the German Ground, but in the absence of small turbot and brill the two grounds agree. My expectation, therefore, of examining during the voyage of the Rhine, grounds which corresponded in their depth and distance from the Lincolnshire coast with the small plaice grounds to the north of Heligoland, was disappointed. Nor could I find other opportunities of making such an examination. I questioned some of the skippers of sailing smacks which fished the home grounds near the Humber, and was informed that they trawled chiefly in the Yorkshire Hole or Little Silver Pit, and the Westernmost Kough, grounds mostly about 20 miles from the coast. The plaice which I saw landed from these boats were small, but there was no great quantity of them, not more than one box from any one boat. Besides the plaice they had about 3 boxes of soles, 3 or 4 boxes of haddocks, and a few cod, lemon soles, and turbot. I bought a sample of the small plaice, and found there were 18 females 8i in- to 12^ in. long; 19 males 8^ in. to 12J in. long. The evidence is, therefore, still incomplete, but as far as it goes it does not support a supposition I had formed that large plaice 20 in. and upwards were found in shallower water, and nearer the land on the English coast than on the German. This supposition was suggested to me by the fact that whereas only small plaice were brought from certain grounds on the German side, I could not dis- cover that there were any grounds ofi' the Lincolnshire coast where only small plaice were caught. At present we have no proof, how- ever, that the larger plaice are to be taken at depths of 7 to 12 fathoms on the Lincolnshire coast. The shallow grounds, close to that coast, are not so extensive as on the German side, and accord- ing to my experience the Grimsby trawlers usually find more profitable fishing in the deep gullies, to which there is nothing corresponding on the German coast, and in which large plaice are taken It may also be noticed that even in the voyage of the John Bull the small plaice became scarce as soon as the ship steamed to a somewhat greater distance from the land. Thus our course from the Spurn Lightship was E.^S., which would take us to a position S.E. of the Sylt Island : at our first haul the depth was 13 to 14 112 NORTH SEA INVESTIGATIONS. fathoms, and we got none of the small plaice, that is to say, none under about 12 inches. The captain said we were 1 Fio. 1. and not, as was to be expected, between the first and second or the second and third leg-ganglion. There is no doubt that in this case we have neither a double-monster nor an atavism, because the ancestors of the Brachyura never had walking-legs on the abdomen. A second paper on this subject, containing minute descriptions and several illustrations, will soon be published in a German journal, and in that I will endeavour to give a theoretical explanation of this abnormality. [ 146 ] Notes on Plymouth Hydroids. By C. C. Nutting. Professor of Systematic Zoology in the University of Iowa. The following notes are based upon observations made during April and the first half of May, 1895. Although the Plumularidos were the special objects of study, a number of facts concerning other forms were noticed, which, together with the discussion of certain matters brought out in the special study of the Plamularidce, were considered by the Director to be of sufficient interest for publication in this Journal. It will be understood that no general discussion of the hydroids at Plymouth is attempted, nor is it my purpose to give a list of the hydroid forms of that exceedingly rich field, no species being mentioned unless some new fact has been observed concerning it, EUDENDRIUM ALBUM, n. Sp.* Hcibitat. On stones in shallow water near Millbay Channel. The stones are often covered with a dense growth of this hydroid, which appears to the unaided eye like white cottony tufts or downy patches. The gonophores were abundant in April. The distinguishing features of this species are the minuteness of the colony and of the individual hydranths, both of which are less than half the height of any other Eudendrium from British waters, and the very striking white colour of the hydranths, a feature not found in any other Eudendrium in that locality. Eudendrium album is one of the most abundant hydroids at Plymouth during the spring, where it has heretofore been regarded as Eudendrium capillare, Alder. It seemed, however, so different from the descriptions and figures of that species given by Alder, Hincks, and Allman, that specimens were sent to the veteran authority on hydroids — Professor Allman — who regarded it as probably new, and advised the writer to describe it as such. • This is the species referred to by Allen, vol. iv. no, 1, p. 49, of this Journal. A full description, with figures, will shortly be published in Ann. and Mag. Nat. Hist, NOTES ON PLYMOUTH HYDHOIDS. 147 Clytea johnstuni, Alder. Medusie of this species were produced in the aquaria in May. Obelia geniculata, Linn. Numbers of the medusre of this species were bred in the tanks and bottles of the Laboratory during the latter part of April. They may be readily distinguished from the medusa) of Obelia dichotoma, which is very abundant at Plymouth, by the fact that the former have 24 marginal tentacles, while the latter has but 16 at the time of liberation. These small medusie are readily preserved with the tentacles well expanded by stupefying with cocaine and passing through three or four grades of alcohol. Obelia longissima, Pallas ? A specimen brought to the Laboratory early in April is referred with some doubt to this species, which it closely resembled in all respects, except in the fact that the hydrothecte were marked with regular longitudinal flutings, the ridges between the adjacent hollows terminating in blunt teeth at the margin. This beauti- ful ornamentation was quite constant in the hydrothecte, and formed so striking a feature as to suggest a new species. The close agreement, however, of the specimen with Hincks' description and figures of 0. longissima, taken together with the great delicacy of the hydrothecte of the latter, render it probable that the form under consideration was 0. longissima, with the delicate hydrothecaj shrunken so as to be thrown into longitudinal flutings. The gonosome was not present. Secured in Millbay Channel from a depth of about eighteen fathoms. Campandlaria neglecta, Alder. This very minute Campanularian was found growing on the stems of Tuhdaria indivisa. There were several gonangia present, but the acrocysts were not developed. So far as I can ascertain, C. neglecta has not been reported from Plymouth by previous observers, probably having been overlooked on account of its small size. It is only occasionally that the bimucronate ornamentation of the margin can be made out. The stem in its manner of branching and flexuose habit resembles a miniature G. Jlexuosa. Campanularia flexuosa, Hinchs. This beautiful species was found with gonosome well developed, on May 1st. The gonangia differed from Hincks' description in being ornamented with shallow but regular annulations throughout their length. At first glance no indication of this annulation is seen, but with proper treatment of light the markings are plainly made out, and appear to be as symmetrical as those so beautifully shown in the gonangia of Clytea Johnstoni. Campanularia fragilis, ffincks. Not before reported from Ply- mouth. The single specimen secured from .the rocks near Millbay Channel was destitute of gonosome, but showed the characteristic tubular plain-rimmed hydrothecte of the species. The hydranths have about twenty tentacles, and the proboscis is ovate in outline when 148 NOTES ON PLYMOUTH HYDROIDS. the hydrautli is expanded, thus differing from most of the Cam- panularidcc. GONOTHYR/EA LOVENI, Allman. This is one of the most abundant species at Plymouth. A number of specimens of the genus that were brought in from time to time during April and May differed so materially from G. lovhii, and agreed so closely with the descriptions of G. hyalina, Hincks, that I regarded them as belonging to the latter species, and had so labelled them, when another batch of specimens was brought in which showed completely intergrading forms joining the typical G. loveni with almost typical G. hyalina. There is a strong probal)ility that these two so-called species are but varieties of one form, which should bear the name of G. lovhii, Allman. Opekcularella lacerata, Johnston. Found growing on young stems of Tubularia indivisa from Millbay rocks, on April 26th. Other specimens were creeping over the stems of Eudendrium. This is, I believe, the first recorded occurrence of the species at Plymouth. Opercularella hispida, n, sp.* This species bears some resemblance to Calycella syringa, Linn., from which it differs in having a much shorter pedicel, a not strictly tubular hydrotheca, a greater number of segments to the operculum, in the absence of the tubular extension of the operculum, and in a much thinner structure, the hydrothecfe being of glassy transparency in 0. hispida, but of a decided brownish or yellowish horn colour in C. syringa. The most striking feature, however, of the present species is the remarkably hispid appearance of the tentacles, which appear to be made up of series of triangular segments on account of the formid- able array of large nematocysts with which they are armed. While examining the expanded tentacles with a i objective, I was so fortunate as to see these batteries of projectiles suddenly explode, sending out a perfect maze of barbed threads, which appeared to be larger and longer than those of any hydroid that I have seen, except Ncmatophorus grandis, Clarke. In the absence of the gonosome, it is impossible to say with any certainty to which genus this interesting little species belongs. The general form of the hydrotheca, the cylindrical hydranth with conical proboscis, together with the convergent teeth, give a facies like that of the genus Opercularella, in which it is provisionally placed. Calycella syringa, Linn. Found growing abundantly on young stems of Tubularia indivisa. The pedicels are often much longer than one would judge from Hincks' figure. The mass of root-stalks from this species running along in approximately parallel lines on the host, and giving off the peduncled hydrothecte, afford a good idea of how the * A detailed description, with figures, will appear in the Ann.' and Mag. Nat, Hist. NOTES ON PLYMOUTH HYDROIDS. 149 fascicled stems of hydroids may have arisen. In some of the speci- mens the aggregation of root-stalks would doubtless be sufficiently rigid to support themselves in an erect position after the stem to which they cling had died, and we should then have a loosely put together, fascicled stem, which a little further differentiation would convert into a typical polysiphonic hydrocaulus. The tubular extension of the hydrothec* reminds one of similar structures in the genus Cryptolaria, which contains several species further related to the one under discussion, in having the operculum composed of convergent segments. CusPiDELLA GRANDis, Hincks. In looking over my Plymouth series of hydroids after returning to America, I found specimens of this species growing over the stems of Halecium tenellum. A careful examination of the stems of the larger hydroids is frequently repaid by the discovery of one or more species of minute parasitic forms which escape the casual observer, and it is quite likely that a number of new species would reward the patience of any one who would devote himself for a time to a search for these forms on British coasts. Halecium tenellum, Hincks. A number of colonies with female gonangia were taken from a depth of 18 fathoms on April 19th. These specimens closely resemble in several points miniature colonies of H. lahrosum, Alder, especially in the shape of the gonangia and the wrinkled appearance of the stems, which, however, are monosiphonic. Indeed, one cannot wonder that Alder mistook H. tenellum for the young of H. labrosum. Out of a large number of colonies of H. tenellum from Plymouth, there are none over half an inch in height, and they very generally show the reduplication of the margins of the hydrophores, which Hincks mentions as a characteristic feature. Plumularia pinnata, Linn. This is by far the most abundant Plumularian at Plymouth, and afforded an excellent opportunity to study the morphology and reproduction of the group. The Ncmatoijhores. There is a great deal of confusion of terms regarding these structures. The name properly applies to both the sarcodal process and the chitinous receptacle into which it retracts, although it is often used to denote either one of these structures. The terms " sarcostyle," denoting the sarcodal process, and " sarcotheca," denoting the chitinous receptacle, have now come into general use. Hincks' description of F. pinnata is incomplete, in that it does not notice the sarcostyles which occur without the investing sarcothecie. One pair of these naked sarcostyles is found in the usual position of the supracalycine nematophores, and another pair is in the axil of each hydrocladium. The structure of the nematophore.'^ has been the subject of much 150 NOTES ON PLYMOUTH IIYDROIDS. discussion, particularly by Hincks, Allmau, Reichart, Merejkowsky, Weismann, and Jickeli. With the excellent facilities afforded by the Plymouth laboratory, and the valuable suggestions of its director, I secured a number of fortunate serial sections of the expanded sarcostyles of P. pinnata, and have been able to satisfy myself concerning the main points of their structure. The results of this study have corroborated the statements of Merejkowsky up to a certain point, including the following facts — 1. The greater part of the sarcostyle is composed of ectodermal cells. 2. There is a central endoderm core (or cylinder ?) * 3. The cells on one side of this core are very large and quadrangular, while the cells on the other side and of the entire terminal portion of the sarcostyle are of ordinary size, 4. There are pseudopodia-like processes from the free surface of the sarcostyle. On the other hand, I have been entirely unable to find any trace of the "interstitial protoplasm" described by Merejkowsky, in which he claims that the ectodermal cells are imbedded. Weismann f boldly suggests that this "interstitial protoplasm" is owing to an assumed necessity for free sarcode to explain the pseudopodia-like processes on the free surfaces of the sarcostyles. It seems to me that there is no logical demand for free protoplasm to explain the great extensibility of these organs. The possible tenuity of the walls of ectoderm cells can be appreciated by any one who has made a study of nematocysts, and a careful examination of the sarcostyles, both living and in serial sections, has failed to afford any evidence of free protoplasm, and this negative result is not antagonized by any physical necessity for free protoplasm in organisms which can construct endoderm cell-walls of the marvellous tenuity and extensibility of the nematocysts. The function of the nematophores is in more doubt than their structure, and is not yet understood. It is practically certain that they are more or less degraded " persons " of the colony which have come to subserve definite functions of great service, judging from the prevalence of these structures throughout the Flunudaridcc. So far as the species under consideration is concerned, it is safe to say that the sarcostyles are not " fighting persons " or " machopolyps," because they are not armed with any considerable number of nematocysts, the special weapons of hydroids. An examination of the living and active sarco- styles establishes the following facts — 1. The almost incredible extensibility of these organs, which wind * Whilii at Naples, the writer was able to demonstrate that this structure, in another species, has a central cavity. t I^ie Entstehung der Sexualzelhn bei den Hydromcdusen, p. 176. NOTES ON PLYMOUTH HYDROIDS. 151 around the stem, branches, hydrotheca, and gonangia, in a perfect maze of threads, or even flattened lobate masses. 2. In retraction, the movement is not comparable to the flowing of pseudopodia, but is effected by decided, quick, jerky retraction, giving an idea of definite outlines and cohesion. To use a crude comparison, the sarcostyle contracts much as if it was made of stretched india- rubber and not of a fluid. It it also worthy of note that there is no mechanical entanglement of the various extensions of the sarcostyles, although they appear to be hopelessly intertwined. 3. The sarcostyles are particularly active in the vicinity of mutilated or dead hydranths and gonophores, particularly the latter, and seem to have a definite object in climbing over the sides and into the interior of hydrothecae and gonangia. There is no evidence that they are able to repair damaged parts. 4. An examination of living sarcostyles, under a high magnification, disclosed certain cells on the distal surface which had the characteristic outlines and movements of amoeboid cells, and contained foreign particles. It would seem from the foregoing observations that the sarcostyles of P. pinnata are primarily neither fighting persons, nor persons con- cerned in the repair of mutilated or diseased parts. It is probable, on the other hand, that they do remove extraneous matter, or dead organic material from the interior of the hydrothec?e* and gonangia, and that they may aid in the capture and ingestion of food for the colony. Origin of the sex-cells. This species is an excellent one for the de- monstration of the coenosarcal origin of the sex-cells in the Plumularidcc as first announced by Weismann.f The gonangia are so excessively numerous that a single series of sections may often be obtained which will show nearly all stages of this interesting process. The course of events in P. pinnata agrees very closely with Weismann's description of the origin of the sex-cells in P. echinulata, both ova and spermato- blasts, arising in the endoderm of the stem and afterwards migrating into the gonophores, ultimately appearing as ova, or sperm, masses in the matured structures. The ova break through the " stutzlamella " and are fertilized and undergo segmentation between the stutzlamella and the ectoderm. Although the ultimate division of the spermato- blasts may take place in the ectoderm, the primary divisions occur in the endoderm. I have been unable to find any cells recognisable as spermatoblasts in the ectoderm, although very satisfactory serial * E. Metsohnikoff, Quart. Jour. Micr. Sci. no. 93. t See Die Enstehung der Sexuahellcn bei den Hydromeduseu , by Dr. August Weismann. The first announcement was in Zool. Anzeiy. no. 75, 1880. NEW SERIES. — VOL. IV. NO. 2. M 152 NOTES ON PLYMOUTH HYDROIDS. sections were made of the male gonophores. It may be, however, that my specimens were too near maturity to furnish couchisive evidence in this matter. In living specimens a division of sperm-cells with partially-developed flagella was observed in the ectoderm. Asexual multiplication of P. pinnata. On April 23rd several colonies of this species were brought in, which were peculiar in having the ends of a number of hydrocladia greatly elongated, destitute of hydro- thecse and nematophores, and distinctly clavate at the tips. Such specimens were brought in almost daily for some time, whenever the boat went out for collecting. The first colonies found were isolated and kept under observation. They rapidly increased in length, and the terminal turgescence became more prominent. In three or four days it was noticed that these enlarged ends were forking and commencing to branch. In about a week after the first specimens were noticed, it was found that the side of the jar in which the colonies were confined was marked with closely adhering thread-like filaments, which, on exami- nation, proved to be the greatly produced hydrocladial extensions mentioned above, and they were still connected with the colonies from which they sprung. From these adherent extensions were growing new colonies of P. pinnata in various stages of development. After a time the connection between the parent colonies and the young was severed by atrophy of the connecting hydrocladial extension, rootlets were put forth from the adherent portion or end of the original hydrocladia, and thus young and perfectly independent colonies were produced which grew rapidly during the next few weeks. Another group of colonies showing the hydrocladial extensions was so placed that the extensions could not touch the sides of the bottle in which they were kept. In this case the hydrocladia grew and forked as before, and new colonies arose from the forked ends of the hydrocladia. The parent stalks afterwards died and fell to the bottom, giving the young colonies a chance to attach themselves to the glass. This process reminds one so forcibly of the sending out of stolons from which new shoots arise, as seen in many plants, that I have pro- posed the name of stoloniferous reproduction for the asexual multipli- cation of P. pinnata as above described.* It is the first recorded instance of the kind among the Hydroida so far as I can find, although it bears considerable resemblance to the fissiparous formation of frus- tules as recorded by Allman.f Plumularia halecioides, Alder. This minute Plumularian was found parasitic on Antcnmdaria. The gonosome was not present. * See American Naturalist, November, 1895. t Oymnohlastic Hydroids, p. 152. NOTES ON PLYMOUTH HYDROIDS. 153 Plumularia alleni * n, sp. Habitat. Found growing on Antennularia ramosa. This delicate species bears considerable general resemblance in size, form, and parasitic habit to F. halecioides. It differs, however, in having a non- fascicled stem, smaller hydrothecse, more numerous nematophores, and especially in the gonangia, which are greatly unlike the annulated structure of F. halecioides. Aglaophenia pluma, Linn. In studying the development of the corbulffi of this species, an interesting fact regarding the sarcostyles was noticed. A young corbula was under examination, the leaves or ribs of which had not yet coalesced, and the sarcostyles of one leaf were seen to stretch across and attach themselves to the next leaf in front, and remain for some time in that position. It appeared as if these sarcostyles served as temporary attachments to hold the edges of the two leaves together, while they were connected by trabiculis of coenosarc, which rapidly formed a stronger and permanent connection. The perisarc of the edges of the leaves seemed exceedingly thin, and in places appeared to be wanting. A contact having been established between the edges of adjacent leaves, the permanent attachment was soon formed, and the coelomic cavities of the leaves established con- nections at these points. A little later, currents of water bearing granules were seen to flow in active streams from one leaf to the other. In their incipient stages it is difficult to tell the difference between sarcostyles and gonophores, and they make their appearance at about the same period in the development of the corbulse. Aglaophenia helleri, MarUanner- Turner etsclur.'^ This is the form collected by Mr. Allen from Eddystone Eocks, and mentioned by him on page 49, volume iv., No. 1 of this Journal. This being the first record of A. helleri on British shores, the following description is given for the benefit of those who may not have access to the original — Trophosome. Colony unbranched, attaining a height of three-quarters of an inch. Stem monosiphonic, divided by very deep nodes into short internodes, each bearing a hydrocladium springing from its antero- lateral aspect. Hydrocladia alternate, closely-set, divided into inter- nodes, each bearing a hydrotheca, and partly divided by two imperfect transverse septa. Nodes very distinct. Hydrothecte obconic, about as deep as the aperture is wide. Marginal teeth nine, unequal in size, the anterior one often being slightly incurved, and rather longer and more pointed than the others ; the second and fourth teeth, counting * Named in honour of the Director of the Plymouth Laboratory, an enthusiastic worker in marine zoology. Detailed description with figures will be published in Ann. mid Mag. Nat. Uist. t Die Hydroiden des K. K. Naturhistorischen Ho/imiseums, Vienna, 1890, p. 271, plate vii. M 2 I I 154 NOTES ON PLYMOUTH HYDROIDS, from behind, are larger than the first and third. There is no apparent intrathecal ridge. Supracalycine nematophores rather small, stout, reaching to the level of the hydrothecal margin ; the mesial nemato- phore springs from just below the margin of the hydrotheca, and projects straight upward and outward, its truncated end reaching to the level of the longest marginal teeth. There are two modified nemato- phores on each hydrocladium near its base. Gonosome. (Description from Naples specimen.) Corbula thick and short, with the leaves or ribs more closely soldered together than in other small British species. Eibs six on each side, with a row of nematophores on their distal edges. Habitat. Found growing on thick roots of marine plants taken from Eddystone Eocks. Distribution. Naples and Eovigno (Marktanner-Turneretscher), and Plymouth, England. [ 155 ] A List of the Parasitic Copepoda of Fish obtained at Plymouth. By P, W. Bassett-Smith, F.Z.S., F.R.M.S., Surgeon, R.N. The material from which the present list of Parasitic Copepoda has been compiled was obtained in part by the examination of fish at the Marine Biological Association's Laboratory, but to a still greater extent by daily and diligent search at certain fishmongers' in the town. The following are the most important works consulted : — 1785. Miiller, 0. F., Entomostraca seu Inseda testacea, Lipsice et Hafnice. 1826 and 1831. Otto and Burmeister, Nova acta Natur Curios. 1832. Nordmann, A. von, Mikrographische Beitragc zur Naturgcscldclite der wirbellosen Thiere. 1834-40. Milne Edwards, Histoire Naturelle des Crustac^s. 1838. Kroyer, H., Om. Snyltehrcbsene isacr med Hensyn til den Danske Faima, Kroyer's Naturhist Tidsskrift, Bd. 2, pp. 7-52, 131-157. 1850. Baird, W., Natural History of the British Entomostraca. Eay Society. 1851. Beneden, P. J. Van, Note sur un CrustacS parasite nouveau, avec V enumeration des especes, &c. Bull, de I'Acad. de Belg. tome xviii. 1, pp. 286-290. 1860. Cla.\xs,C., Zur Mo rphologie der CojMpoden. Wurzburg naturwiss Zeits. i. pp. 20-36. 1862-68. Hesse, Observations sur des Crustacds rares ou nuuveaux des cotes de France. 16 papers, Ann. Sci. Nat. 1865. Heller, C, Crustaceen, Keise der Fregatte Novara. 1866-79. Gerstacker, A., Crustacea, vol. 5, Bronu. Class, und Ord. des Tliierreichs, Copepoda, pp. 590-806. 1875. Claus, C, Ueber die Entwiekehoig, Organisation und systematischc Stcllung der Argulidat. Zeits wiss Zool. vol. xxv. pp. 217-224. 156 A LIST OF THE PARASITIC COPEPODA 1875. Claus, C, Neue Beitrdge zur henntniss der parasitischer Cope- podcn, ncbst hemcrkungcn uber das System, derselben, tome cit. pp. 327-360. 1877. Kurz, W., Studien iiher die Familic der Lernccopodiden,. Zeit wiss Zool. vol. xxix. pp. 380-428. 1877. Vogt, C, Becherchcs Cotidrcs, Arch. Zool. Exper. vol. vi, pp. 385-456. The system of classification here adopted is that of Gerstcecker, which is founded largely on the minute anatomy of the animals, and is the most recent. CALIGID^. Caligus, Muller. Second and third pair of thoracic legs bifid ; each branch with two joints, first and fourth not bifid. Fourth pair with elongated basal joint; cephalothorax not deeply notched in the centre, frontal lobe bearing a sucking disc near the base. a. Abdomen long. 1. Caligus rapax, Milne Edivards. This species was taken in abun- dance on the surface of the scales of sea trout, Salmo tridta (with Lepeophtlieirus stromii), in the mouth of cod, Gadtts morrhua, and rarely on the surface of grey mullet, Mugil capita. Male generally found accompanying the female, but in smaller numbers. 2. Caligus diaphanus, Nordmann and Kroyer (not Baird). Found in quantity on the inner surface of the operculum of 2Vigla hirundo and T. cucidus. This species is very small, but agrees exactly with Kroyer's description and plate. 3. Caligus scomberi, n. sp* I have been unable to place this with any recorded species, and have therefore named it after the fish it is taken from. It is found on the inner surface of the operculum of Scomber scomber. It much resembles the last, but the carapace is oval instead of being rounded, and the abdomen is much longer. 4. Caligus elegans (?), Van Beneden. A doubtful specimen from the mouth of Gadus morrhuce. 5. Caligus ( Sciosnophillus) tenuis, Van Beneden. Found on the inside of the operculum of Scicena umbra. Four specimens were found, on the only fish of the kind examined, and were unmistakeable. b. Abdomen short. 6. Caligus minimus, Nordmann. A number of specimens of both sexes were taken from the gill cavity and mouth of the bass, Labrax * A liescriptioD, with figures, of this and the other new species mentioned in this paper, at present in manuscript, will be published shortly elsewhere. OF FISH OBTAINED AT PLYMOUTH. 157 lupus, in June and October. The Hamulus acccssorius anterior is particularly long, and the second maxillipedes in the male are very strong and large. 7. Caligus Millleri, Leach, was found on the surface of the body of poor-cod, but was only seen on a few occasions, a large number of males being taken proportionately to the females. The same Caligus was also found on Trigla gurnardu^. 8. Caligus curtus, Mi'dler. This species was taken frequently from the mouth of the cod. Both the description and figure in Mliller's work are very indefinite. This species differs from the latter in being rather smaller, the furcula branches longer, and the abdomen rather bigger. 9. Caligus gurnardi, Kroycr. One specimen of this species was taken from the gill cavity of Trigla cucuhis in June. 10. Caligus hrevipedis, n. sp* Two specimens of this curious form were taken, in August, from the gill cavity of Motella tricirrata. It differs from all other described species in the rudimentary condition of the fourth pair of thoracic limbs. The same character was found in both specimens, so that it could not well be an abnormality. Lepeophtheirus, Nordmann. Frontal lobes without sucking discs ; fourth thoracic segment free ; genital segment without lobes on the back ; abdomen appearing free behind. a. Abdomen long, 1. Lepeophtheirus stromii, Baird {vesper of Milne Edivards). Speci- mens of both sexes of this species were found in quantity on the surface of the body of salmon and salmon-trout in June and July. 2. Lepeophtheirus pollachius, 7i. sp* Both sexes taken in quantity from the palate and back of the tongue of Gadus pollachius, also from the gills of the ling, Molva vulgaris. This species is nearly allied to the last mentioned. 3. Lepeophtheirus Thonipsoni, Baird. In the gills of turbot and brill, Rhonibus maximus and laevis. The specimens of this species were generally found in great numbers in the gills of the above-mentioned fish ; I have taken as many as thirty from one. The specimens described by Kroyer as L. rhombus is closely allied in detail, but the carapace as represented by him is very small and round, whereas in this species it is large and distinctly oval, as shown by Baird. 4. Lepeophtheirus ohscurus {?), Baird. Found in the gills of Rhombus laevis only. This species has outwardly a very close resemblance to * See former note, p. 156. 158 A LIST OF THE PARASITIC COPEPODA the last, but the furcula is distinctly and markedly difterent, the branches being short, and each branch bifurcating. The male agrees with the description given by Baird of a specimen which I believe he mistook for a female. As this specimen was also taken from the brill, it is likely that they are one and the same species. I have therefore named my specimen accordingly. h. Abdomen short. 5. Lepeophtheirus 2Jecioralis, Muller. This species was very common, taken all round the year, from plaice, flounder, and dab ; very fre- quently attached to the posterior surface of the pectoral fin, but they were often seen moving actively about over the body of newly-caught fish. Especially common on the flounder. Both sexes abundant. Elytrophora, Gerstcecker. (1) All four pair of legs two-branched, the terminal branch of all provided with long plumose hairs. (2) The number of joints in each branch varying. (3) The outer and inner branch of first pair two- jointed, both branches of second and third with three joints, the inner branch of fourth with two only. Elytrophora hrachyptera, Gerstcecker. From the gills of a large tunny, Tliynnus thynnus, taken outside Plymouth, I obtained ten specimens of this species, five of each sex, all alive. These I watched for several hours in a bell-glass. They were very active, and the males were seen to attach themselves to the females in the position repre- sented in Dr. Heller's work, firmly fixed by the hook-like posterior antennae, and second maxillipedes. Trebius, Kroyer. (1) All four pairs of legs two branched, the terminal joints of all provided with long plumose setae ; (2) the outer and inner branch of the first pair with two joints, both branches of second, third, and fourth with three joints. Trebivs caudatus, Kroyer. Specimens were found on the dorsal surface of the head, and in the nasal cavities of the skate, Baja batis, but were not common. One was also taken from the skin of a pollack, but possibly may have found its way there during the manipulation of the fish in the boats or on the quay. Cecrops, Leach. (1) The end joints of the bifid branches of all the true legs, with short hook-like bristles, or having smooth edges ; (2) front edge of the cephalothorax deeply cut, two lobed ; (3) anterior antennte covered. OF FISH OBTAINED AT PLYMOUTH. 159 Cecrops Latreillei, Leach. Two specimens were found in the gills of sunfish, Orthagoriscus mola. Pandarus, Leach. (1) Front edge of cephalothorax, not deeply lobed ; (2) anterior antenna free ; (3) cephalothorax broader behind than in front ; (4) first pair of maxillepeds cheliform ; (5) the outer branch of first true leg single-jointed, the inner with two joints, both branches of second and third pairs two jointed, branches of fourth pair one jointed. Fandarus hicolor, Leach. A number of specimens of this species were taken from the surface of Scyllium catidus. DICHELESTHINA. Leknanthropus, Nordmann. (1) Abdomen without dorsal plates ; (2) the two posterior pair of limbs changed into lamellar appendages ; the two first pair very small. Lernanthropus Kroyeri, Van Beneden. From only one Lahrax lupus, in over a dozen examined, did I find any of these curious animals. This was a full-grown fish, and twelve were found, some on the gills of either side. Many of them had the abdomen as a tense bag of bloody fluid, and most had spermatophores attached. Clavella, Oken. (1) Anterior antennfc single, six-jointed, projecting under the edge of the cephalothorax ; (2) posterior antennte with single hook-like claw ; (3) only the anterior pair of limbs formed ; (4) genital segment of female, five to six times as long as the anterior part of the body. Clavella mulli, Van Beneden. A number of specimens of this minute species were taken from the gills of the red mullet, all females. The long straw-coloured ovarian tubes are easily seen projecting beyond the gills. Cycnus, Bd wards (Congericola, Vom Beneden). All four pairs of limbs formed, and two branched anterior antenna^, six-jointed. Cycnus {Congericola) pallida, Van Beneden. This species was not common. From 14 well-grown conger, I only obtained specimens in two : eleven altogether. They are, however, very difficult to find. The posterior antennae are very strong and large, compared with the last genus. 160 A LIST OF THE PARASITIC COPEPODA LERN^ODEA. Penella, Ohen. Thoracic legs close together, found just behind the head, neck without distinct segments, egg sacs thread-like, the hinder part of the body (the genital segment) joined to the neck in a straight line ; from the end of the latter projects the abdomen, as a long plumose rod. Head rounded and corrugated, carrying behind it two arm-like projections. Penella sagitta ? Linn. One specimen was obtained from the Labora- tory, but from what fish was not known. LERNiEONEMA, 3filne Edivards. Genital segment passing gradually into the neck ; head obliquely cut off, or rounded in front ; genital opening placed far off from it ; thoracic legs with developed oar-like joints. 1. Lernceoneina monillaris, Milne Edwards. A very perfect specimen of this species was found attached to the sclerotic of a young herring taken in November. There was no malformation of the eyeball. 2. Lernxonenia encrasicola ? Van Beneden. A broken specimen, probably belonging to this species, was taken from a Clupea alosa. Lernea, Linn. Genital segment dilated, bent in the form of an S, and twisted on its axis; head in front bearing slender forked processes; neck short, simple; all four pairs of thoracic legs unfolded. 1. Lernea hrancliialis, Linnaeus. Specimens were taken from the gills of the cod, bass, whiting, haddock. The body is always full of sanguineous fluid, and the head with its long horns, together with the neck, are deeply buried in the tissues of the gills and head, being surrounded by a laminated clot of blood encysting those parts completely. When once fixed there is apparently no power of movement. The gill cavity of a whiting would appear to be almost filled up with one of these large parasites, and they must materially interfere with the action of the gills. 2. Lernea lusci, n. sp.* This animal was found only in the gills of whiting-pout, Gadus luscus, and was very common, as many as four being found on one fish. The whole head is surrounded by a clot of blood, the elongated horn being buried by the side of the gill bone. * See former note, p. 156. OF FISH OBTAINED AT PLYMOUTH. 161 CHONDEACANTHINA. Chondracanthus, De la Boche. (1) Cephalothorax not separated from the abdomen by a long thin neck. (2) »ont end of the body neither thicker nor more slender than the posterior part. (3) Posterior antenna? in the form of hooks. (4). Cephalothorax without processes. (5) Abdomen compressed with concave sides, or with elongated lobes. Behind the second maxillipedcs are two pairs of lobed processes, representing the thoracic limbs. {a) Two small horns at the posterior angles of the thorax. 1. Chcnulracantlms cornutus, Muller. A great number of specimens were taken from the gills of the Plaice, P. jplatessa, Flounder, P. Jicsiis, and P. megastoma. They differed very much in size, being small and especially abundant in the Flounder. The male was almost invariably found fixed on the abdomen of the mature females, by means of its strong, hook-like posterior antennae. 2. Chondracanthus solea^, Kroyer. Found in the gill cavity of Solea vulgaris, but not common ; male like the preceding. 3. Chondracanthus clavatus, n. s}^* Found only on the gills of P. microceplmlus. (b) A number of supplementary lobes on the sides, none on the middle line. 4. Chondracanthus triglcc, Blainville {G. asscllina, Linn). These were plentifully taken from Trigla gurnardus, T. cuculus, and T. hirundo. The whole anterior portion of the head, and so-called neck, is buried in a ileshy mass in the substance of the gill, the thoracic portion only showing. 5. Chondracanthus merluccii, Holten. Taken from the mouth of Gaelics merluccius, and is very common ; in no fair-sized hake have I ever found it absent. Great numbers are often found together, large areas of mucous membrane being destroyed. The very large hooks of attach- ment (the second antennae) being deeply buried, strong muscles are inserted into the bases of these, both for abduction and adduction, so that one would gather that the animal is able to relax its hold, and probably move from place to place. The male resembles closely that of C. cornutus; in fact, no matter how varied the form of the female in this genus, the males are perfectly distinctive. It was also noticeable that one female would often have more than one male attached, usually to the abdomen. At times as many as five or six would be found fixed on to the various parts of the animal. Occasionally young Caligidce were also present as secondary parasites. * See former note, p. 156. 162 A LIST OF THE PARASITIC COPEPODA (c) Supplementary horns in the median line. 6. Chondracanthus Zci, De la Roche {De la rochiana, Blainville). Found on the gills of Zeus faber. This, too, is very common ; one of these being usually found on either side in the anterior angle of the gill cavity. When very small, the horn-like processes are soft and crowded. Male like that of G. cornutiis. 7. Chondracanthits lophii, Johnst. (Ch. r/ihhosus. Kroyer). Found in almost all well-grown angler tish, Lophius inscatorius, attached to the gills. LERNiEOPODID^. LERNiEOPODA, Kroyer. Cephalothorax short, not attenuated, plainly separated from the body. Maxillipedes of the second pair, long, thin, arm-like, united at their ends ; Cephalothorax one-jointed, oval. Body narrow, bag- like, only slightly segmented. 1. Lernos,opoda salmonea, Linn. {L. carpionis, Kroyer). One female specimen found on the gills of Sahno salar. 2. Lcrnmopoda galei, Kroyer. Many specimens of this animal were taken from Mustelus vulgaris, Galeus vulgaris, Acanthias vulgaris. They were found attached to the soft skin behind the pectoral and anal fins, more particularly in the deep folds by the anal fins of the male fish, and were frequently taken alive. BiiACHiELLA, Cuvier. Cephalothorax markedly thin and elongated, often ringed like a worm. Second maxillipedes are long, arm-like, only united togetlier at their extremity as in the preceding genus, but without articular appendages at their base as in Tracheliastes. 1. Brachiella thynni, Guv. From one large Tunny, Thynmis thynnus, I obtained four specimens, attached to the soft skin, behind the pectoral fins, two on either side, two being mature and two quite small. 2. Brachiella insidiosa. Heller. These were found attached to the gill rays of the hake, Gadus merluccius, being fairly common. They agree very closely with that described by Heller (obtained from a species of Gadus in the Mediterranean), except that the arms are rather shorter, and the cephalothorax is more acutely bent. Both females and males were found. 3. Brachiella impudica, Nordmann. A number of specimens were taken from different species of Gurnards — Trigla cucidus, T. gur- nardus, and 1\ hirundo. Tliey were generally found attached to the soft skin on the inner side of the operculum near to the border, and were very characteristic. The male was generally found fixed OF FISH OBTAINED AT PLYMOUTH. 163 upon the back of the cephalothorax, and has been described by Milne Edwards. Var. parva ? Very frequently a smaller animal was also found on the same fish, in like positions, apparently differing only in not having any secondary lobular prolongations on the arms. They had the three pairs of horn-like processes posteriorly, and the males appeared identical ; but as they bore egg sacs, they might be specifically difl'erent. 4. Brachiclla bispinosa, Nordmann. Found in quantity from Trigla cucuhis, T. garnardus, T. lyra. Attached to the gill rakers of the outer branchiie ; rarely more than two on each fish. The head has the same characteristic organs as in B. impudica. The male, which is found at the back of the cephalothorax, has also equal resemblance. 5. Brachiella triglcv ( Anchorclla triglcv, Claus). This species is found attached to the gills of the various Gurnards, T. cucidus, gurnardus, and Mrundo, but was not very common. Although in its outward form the female has most of the characteristics of an Anchorclla, the male dis- tinctly shows it to belong to this genus. 6. Brachiella 7nerluccii, n. sp* These animals are always found attached to the points of the gill-rakers of the Hake, Oadus raerluccius, and never attached to the gill rays themselves, as B. insidiosa. Both were frequently found in the same fish, but their positions were never other than that noted. Anchorella, Cuvier. Second pair of maxillipedes short, united together, ending close to their origin, in a fixing organ. (Male showing no trace of segmentation of the body, which is not elongated, but globular. B.-S.) 1. Anchorella emarginata, Kroyer. This species was found attached to the gill-rakers of the outer branchiie of Glupea alosa. The second pair of maxillipedes are not completely united at their base. 2. Anchorella paradoxa, Van Beneden. Found on the gills of Scomber scomber, but rare. The species is, however, very characteristic, and the male is distinctive, but has not yet been described by any author.* 3. Anchorella uncinata, Muller. This species is extremely common, being found in the folds of skin around the mouth, and in the gill-cavity of cod, haddock, pollock, whiting, and whiting-pout. The organ of adhesion of this species is a perfect drill. 4. Anchorella quadrata, n. sp* A few specimens were obtained of this species from the Dragonet, Callionynms lyra, attached to the gill rakers. This species is much like Anchorella falax. Heller, in form, except for the great size of the abdomen. • See former note, p. 156. [ 164 ] Faunistic Notes. By E. J. Allen, B.Sc, W. Garstang, M.A., E. T. Browne, B.A., and T. V. Hodgson. Notes on Dredging and Trawling Work during the latter half of 1895. — During the summer and autumn of the year 1895 it was possible, with the aid of a grant made for the purpose by the Govern- ment Grant Committee of the Eoyal Society, to carry on dredging work with some regularity in deeper water, and at greater distance from Plymouth Sound, than had been possible in previous years. Our efforts were concentrated upon the grounds lying between Start Point and the Eddy stone, with a view to compiling a chart showing the nature of the bottom at each spot, and the animals and plants which live there. For this purpose samples were taken, as far as possible, of every species brought up by the dredge and trawl, and preserved for identification, note being made of the relative abundance of each species. With the exception of the Polyzoa and Polychsetes, the material collected has now been worked over, and lists of the animals obtained at the different spots drawn up. It would not, however, be advisable to publish the full details at the present stage, as it is our intention to work the same grounds again during the first six months of 1896, at the end of which time the results of the year's work will be combined, and a detailed chart drawn up. Many conclusions, gathered from a study of the rough charts already made out, require to be checked, and others, perhaps, will require modification. Broadly speaking, the district under investigation can be divided into three principal regions, characterized not only by the nature of the bottom, but also by the animals which live there. The first of these comprises the grounds around the Eddystone, where the bottom is, for the most part, composed of broken shell ; the second, a broad stretch of sandy ground, extending from a couple of miles east of the Eddystone to a line drawn about north and south, and FAUNISTIC NOTES. 165 passing through Bolt Tail ; and the third includes the off-shore grounds between Bolt Head and the Start, where gravel, broken shell, and soft rock predominate. Each of these three principal regions is, of course, capable of considerable further sub-division, but an account of these, with their inhabitants, must be postponed. It may be well, however, to give some notes on a few of the rarer animals found, or of those which have not previously been taken by the Marine Biological Association at Plymouth. Paraphellia expansa, Haddon. Three or four specimens of this interesting anemone were dredged, on August IGth, in about 26 fathoms, at a distance of 3 miles N. W. of the Eddystone. The surface was covered with fine particles of gravel. One of the specimens is still alive in the Laboratory. This species, for which a new genus was formed, was first obtained by Haddon at the mouth of Bantry Bay, in a depth of 40 fathoms, and was described from two specimens — one obtained in 1885, and a second in the following year.* Specimens have since been obtained by Prof. Herdman from near the Isle of Man.f Sarcodictyon catenata, Forbes. The red variety was common on shelly grounds, both round the Eddystone and off Prawl Point. Heteroconlyle conyhcarci, Allman. Four colonies of this rare hydroid were dredged near the East Eutts, on August 30th. The species was identified by Mr. E. T. Browne, to whom the following note is due : — Each colony was on a large shell of Buccinum undatum, inhabited by the common Hermit Crab, Eupagiirus hcrnhardus. The colonies corre- spond to the description given by Allman. There was no difficulty in identifying the species as the gonophores, each with a single ovum, were present in large numbers upon the blastostyles. This hydroid was first taken by Allman in Glengariff Harbour, Bantry Bay, and afterwards by Hincks at Oban, which are, I believe, the only localities where it has been found. Of the other Hydroids, Thuiaria articulata, Pallas, and Diphasia tamarisca, Linn., are worthy of mention. Ophiadis hcdli, Thompson, was abundant around the Eddystone, and especially so off Prawl Point. Ophiura affinis was also taken at the latter place, and a single specimen of Echiyiocardium pennatifidum, Norman, was dredged from a bottom of broken shell, about 5 miles south of Bolt Head. Polyyordius sp. occurred in numbers in gravel and broken shell dredged off Prawl I*oint (34 fms.), and a few were also taken from a ground of fine broken shell (20 fms.) south of the Eddystone. * Haddon, "Revision of Britisli Actiniae," Trans. Hoy. Dub. Sue. iv. (Series ii.) p. 321. t Brit. Assn. Report, Ipswich, 1895. 166 FAUNISTIC NOTES. Enpolia curta, llubrecht. This uemertine was found on three occasions, and was identified by Mr. Riches, who had already taken a specimen in the neighbourhood. It has not previously been recorded for the Atlantic, but occurs in the Mediterranean, at Mauritius, Polynesia, and the West Coast of South America.* We have taken it in the following localities : (1) \ mile N.W. by h N. of Eddystone, August 16th, ground fine broken shell (17-20 fms.); (2) Off Borough Island, August 20th, soft red rock interspersed with gravel (17 fms.) ; (3) 5 miles S. by E. of Prawl Point, September 17th, shells, broken shell, and gravel (34 fms.). Dondersia hanyuhnsis, Pruvot. {Arch. Zool. Exper. et Gen. ix. 1891, p. llb) = Myzoiiicnia hanynh'nsis (Simrot, "Mollusca," Bronn. Thier- Rcichs, 1893, p. 231.) This interesting neomenian, for the identification of which I am indebted to Mr. Garstang, was taken 3 miles E. by N. of the Eddystone, on the 30th September, in 30 fathoms. Four specimens of the bright red variety were found on the hydroid Lafoea dnmosa, var. robusta, growing on Pecten shells. The species has previously been found, also on Lafoea dumosa, at Banyul and Eoscoff. Lyonsia norvegica. This lamellibranch was obtained off Prawl Point. A specimen was subsequently taken off Stoke Point. In addition to the above, which were obtained from deeper water, the following species taken in the ordinary collecting work of the Laboratory may be mentioned. Tuhiclava lucerna, Allman, growing on stones dredged from Millbay Channel (within the Sound), on November 14th. Gonophores were not present. The species is much more slender than Tuhiclava cornucopia, Norman, and the corrugation of the polyj)ary, and its dilatation at the base of the polypite, were very marked. It has previously been taken by Allman, in a rock-pool at Torquay and in Dublin Bay. It does not appear to have been since recorded. Stylocho'plana maculata, Quatrefages, was found in numbers on December 11th, crawling upon zostera dredged in Cawsand Bay. Gamble f gives the following localities for this species : Berwick Bay (Johnston); Firth of Forth (Dalyell); Firman Bay, Guernsey (Laukester); St. Andrews (Mcintosh); Jersey (Koehler); St. Malo (Quatrefages); St. Vaaste-la-Hogue (Clapar^de). It has not been previously recorded for this district. E. J. Allen. • See BOroer. Nemertinen. Fauna u. Flora d. Oolfes v. Neajwl. 1895, where an interesting chart is given showing the distribution of the Genus Eupolia. t Quart. Jour. Micr. Sci. xxxiv. 1892-93, p. 498. FAUNISTIC NOTES. 107 On Doris maculata, a new species of Nudibranchiate Mollusk found at Plymouth. — Under the name Doris maculata, I describe a small Dorid of striking appearance, which has been several times obtained at Plymouth, and which seems to be quite distinct from any form hitherto described. Pending the appearance of a more complete account of the anatomy and affinities of this interesting form, the present note will enable naturalists to recognise its appearance, and to identify it in the event of additional specimens being found. A brief reference to this animal occurs in my "Paunistic Notes at Plymouth for 1893-94." {Jour. Mar. Biol. Assoc, vol. iii. 1894, p. 220.) The notffium of Doris maculata is usually about twice as long as broad, the sides being approximately parallel, and the two extremities equally rounded. The body, however, is flexible, and the actual form of the animal varies accordingly at different times. The largest specimen observed was nearly one inch in length, and proportionately stout and broad ; but the usual length of the specimens obtained varies from three-eighths to three-quarters of an inch. The rhinophores are large, distinctly laminated, and completely retractile. The edge of the rhinophoral cavity is very slightly, if at all, elevated, but is usually provided with a pair of purple tubercles at its sides, one lying on the inner side, the other on the outer side of the cavity. The circumanal gills are constantly five in number, and are so situated that one gill is anterior and median in position, two others form an antero-lateral pair, and the remaining two a postero-lateral pair, symmetrically disposed with regard to the anus. The gills are simple pinnate plumes, completely retractile within a cavity, and are held out somewhat stiffly in expansion. The peribranchial fossa is bounded by a thin raised lip, which is beset with a number of small tubercles, some of which are pigmented with purple granules. The foot is broad, and, although concealed beneath the notteum when the animal is at rest, projects slightly behind it during locomotion. The anterior margin of the foot shows a transverse groove, which separates a slender propodial lip from the rest of the foot. The propodium is quite simple, and shews no trace of a division into two lateral halves. On each side of the oral protuberance is an oral tentacle, whose shape is bluntly conical, or digitiform, according to its state of elongation. The feature which gives this new Doris its most distinctive appear- ance is the presence, on the back, of a number of conspicuously coloured tubercles, connected with one another by a network of low ridges. These tubercles are of different sizes, and there is a good deal of NKW .SKKIES— VOL. IV. NO. 2. -^ 1G8 FAUKISTIC NOTES. irregularity in their arrangement. It is usually possible, however, to recognise two longitudinal rows of particularly large tubercles, three or four on each side, which extend from the rhinophores to the peri- branchial fossa. These two rows of large tubercles are situated along a pair of lines which are the sites of tubercular or pigmented modifi- cations in certain other types of Dorididce, e.y. the sub-lateral rows of filaments on the back of Idalia Lcachii, and the post-rhinophoral rows of pigment-patches in Doris {Jorunna) Johnstoiii. In Doris maculata there is also an irregular median series of tubercles, as well as a number of smaller lateral tubercles irregularly scattered over the back between the main sub-lateral rows and the margin of the notseum. The tubercles are of a deep purple colour, due to granular deposits of a purple pigment. The ridges which connect neighbouring tubercles with one another are often slightly granulated with the same purple pigment. In specimens in which the serial arrangement of the tubercles is not well defined, the general appearance is that of a central network of ridges, radiating out into irregular lines at the sides. The tubercles arise from the nodes of the network. Since the general colour of the body is bright yellow, the contrast effected by the purple tubercles and ridges renders this little creature a very striking object in a mass of dredged material ; it is, moreover, easily recognised as distinct from any British Doris hitherto described. Doris maculata was first found by me at Plymouth on December 18th, 1893, when two specimens were dredged. It has since been obtained on several occasions, but always from the same locality — the western part of Plymouth Sound, known as the New and Queen's Grounds. The bottom here is clean, and consists largely of hard rock and stones, which graduate into beds of shells to the south. The flora and fauna are characterized by the occurrence of Dclcsseria, Anten- nularia, numerous Pohjzoa, and Morcliellium argus. W. Gakstang. On the changes in the Pelagic Fauna of Plymouth during September, 1893 and 1895.— During a visit to the Plymouth Laboratory, in September, 1893, and in September, 1895, for systematic work on medusa3, it was almost a daily occupation to examine with a microscope the contents of the tow-net, for the purpose of obtaining the earliest stages of medusa?. Whilst thus occupied, I noted down not only the meduste seen, but also other pelagic animals. I propose to give here a few notes to show the change in the pelagic fauna for the same month in different years. This FAUNISTIC NOTES. 169 is not intended for a complete list of all the animals seen, but only a few of the more interesting ones are given, and tliose which show the changes in quantity, Noctiluca miliaris. — Bles (1892) states : " The absence of Nodiluca is a very extraordinary feature of the year, for 1891 was remarkable for the immense profusion of this infusorian, which in the months of June and July was present in such numbers that it discoloured large stretches of sea. This year it has been almost entirely absent, and a few individuals, which I found at the end of September, were the only signs of its existence." In 1893, I found Noctiluca almost daily in the tow-net, the quantity varying day by day. On some days the top of the tow-net jar was covered with a thick layer. In 1895 not a single specimen was seen during September.* Liriantha appendicidata was exceedingly abundant in 1893, during September and the early part of October. Mr. Garstang sent me an adult male on October 23rd. I never saw a single specimen in 1895. Amphincma dinema was fairly common during the whole of September, 1893 ; only a few small specimens seen in 1895, the last on September 20th. Lai' SabeUarum ( = Willia stellata) was fairly abundant during the whole of September, 1893, especially the early stages ; but scarce in 1895, and only medusai belonging to the first and second stages were seen. Dipurena haltcrata, a single specimen taken on 25th September, 1893. None seen in 1895. Lizzia hlondina was not taken during September, 1893 ; but Garstang obtained specimens during the summer months. During the early part of September, 1895, this medusa was fairly abundant, and disappeared about the middle of the month. Solmaris and Ociorchis. — Two early stages of a Solmaris, and a specimen of Octorchis were taken on 7th September, 1895, about two miles south of the Breakwater. Botli genera are new to Plymouth. The Solmaridae (Narcomedusffi) inhabit the Mediterranean and the Tropical Seas. Octorchis is also a Mediterranean medusa. On 10th September, 1895, a new species of Dipurena was taken, and on the 17th vSeptember several specimens of Eiichilota, also new to British seas. The medusiB were certainly not so abundant in September, 1895, as in September, 1893. This may have been due to the enormous number of Doliolum and Muggicca which daily entered the tow-net. In 1893, Doliolum was scarce during September, and Liriantha exceedingly * Noctiluca did not appear until December, vitfc Hodcikon, infra, p. 171. — Ed. N 2 170 FAUNISTIC NOTES. abundant. Ohelia Incifcra was exceedingly plentiful during the whole of September, 1893, but in 1895, though a few specimens were taken daily at the beginning of the month, the great crowd did not appear until September 14th, then in the shallow water of Whitsand Bay, but soon swarmed everywhere, along with Muffjicea and Doliolum. Mwjgiwa atlantica, Cunningham. — Cunningham (1892) has given a description of this species. He first obtained specimens near the Eddystone on September 12th, 1891, "and afterwards it was obtained in great abundance close to the Plymouth Breakwater, and even inside the Sound. It was brought in numbers to the Laboratory almost every day up to about the middle of October, but after the end of that month it was not seen again." Cunningham (1892), p. 398, gives an earlier history of this siphono- phore, and also states that in 1892 it was very abundant at I'lymouth, about the middle of September, but decreased considerably towards the end of the month. In 1893, Muggicra was present during the whole of September, and during the early part of the month fairly abundant. In 1895 it was exceedingly abundant. * Beroe. — A single specimen taken on 19th September, 1895, about 3 mm. in length. Echinoderm larvm. — In 1893, Plutei were abundant during the early part of September, but very scarce towards the end. In 1895 several kinds were seen, some very abundant at the end of the month. The Bipinnariffi, described by Garstang (1894), were first taken at Plymouth in 1893, during August, and apparently disappeared before my arrival, as I saw none during September. But, in 1895, a few specimens were occasionally taken. Pilidium. — I did not see any larva3 during September, 1893, but frequently saw them in 1895. Fairly abundant on September 7th and 19th. Terchella. — The larval form in its tube was always present in the tow- net during September, 1893 ; a sudden increase occurred on September 23rd. In 1895, none seen until September 13th; after this date a few were generally present in the tow-net, but they were never abundant. Clicetoptcrus. — In 1893, one or two larvjo were usually taken every day. In 1895, a few were seen at the end of August, but none during September. Polynoe. — In 1893 a few of the early larval stages were taken about the middle of September. In 1895 a few were occasionally seen, but scarce. * Cf. HoDtiSON, infra, p. 174. It reinaiued this year (1895) uutil the middle of December. — Ed. FAUNISTIC NOTES. 171 Magelona. — Abundant throughout the whole of September, 1893. On some days I counted the specimens seen — September 21st, 30; 22nd, 20 ; 23rd, 5 ; 25th, 50 ; 2Gth, 35 ; 27th, 38. On September 23rd all the Polychaete larvoe were scarce, but meduste and other animals did not show any visible decrease. In 1895, Magelona was not nearly so abundant ; often only a few present, occasionally none seen. On September 13th it was fairly abundant. Mitraria. — This appears to be a rare animal on the southern coast of England. I only obtained three specimens on 31st August, 1895. Dr. Fowler informs me that some were taken a few years ago at Plymouth, but were not recorded in the journal. Vallentin (1891) records Mitraria for Falmouth in July, 1890. Actinotrocha. — None seen during September, 1893. Very scarce in 1895 ; only a few specimens seen ; the last taken on September 19th. Rotifei-a. — Garstang (1894), p. 235, writes — "Apparently character- istic of this period (September) are the clouds of pelagic Eotifers, which may be occasionally taken." I cannot find any references to Rotifers in my notes for 1893. Certainly none appeared during Sept., 1895, as I kept a special look out for the benefit of a friend.* Thalia democratica-mucronata. — Garstang (1894) states the nets were crowded with Salps in June, 1893. I saw none during September, In 1895 a few specimens were taken on September 9th only. Doliolum tritonis. — In 1893 a few specimens were taken at the beginning of September, but soon became scarce. One or two occa- sionally taken at the end of the month. In 1895, Doliolum was exceedingly abundant at the beginning of September. Often the tow-nets were crowded with specimens. There was a gradual decrease towards the end of the month. Tornaria. — None seen during September, 1893, but often taken in 1895. Fairly abundant at the beginning of September, and a few were occasionally taken at the end of the month. This is the same species, Tornaria Krohnii, which Bourne (1889) found at Plymouth in 1888, during August and September.* Ami^ioxus. — A specimen taken in the tow-net on September 3rd, 1895, about 2 mm. in length, and another on September 7th, about 3 mm. in length. None seen during September, 1893. In some of the species the variation is great, as they are absent in one year and abundant in the other. Little value, however, can be attached to the slight differences in numbers, as a species may be present every year, but owing to its scarcity escape the tow-net, which after all only traverses through a very small portion of the sea, even in * Cf. Hodgson, infra, p. 176-7. — Ed. 172 FAUNISTIC NOTES. the course of a month. I have given these rarer forms to show that they do occur in September, and they may be of use to other naturalists on fauuistic work. The following list is drawn up to show more clearly the variation in the fauna for the two years : 1893. 1895. abundant . . absent. Nodiluca . Liriantha . Chcctopteriis Dijnirena . Amphincma Lar {Willia) Magelona . Doliolum . Pilidium . Tornaria . Lizzia Actinotrocha Thalia Bipinnaria Mitraria Amphioxus . Beroe Solmaris OctorcMs Dipurena (sp. ?) EucMlota . few daily one fairly abundant abundant few absent all show a great decrease. very abundant, fairly abundant. few. » three, two. one. •all new to Plymouth. From this list it is easily seen that more interesting animals were taken during September, 1895, than in 1893. The cause is difficult to account for ; it may, perhaps, be due to the weather, which was exceptionally fine during September, 1895. There was scarcely any rain, but plenty of sea mists and fogs ; the last week of the month was exceptionally hot. The sea was usually calm ; in fact, September was an ideal month for marine work. The weather during the summer months was very changeable. Mr. Allen informs me that May and June were fine, July was stormy and wet. There was a spell of fine weather at the end of July, and during the first few days of August, then unsettled weather until middle of the month, when the fine weather commenced, which lasted till the end of September. Garstang (1894) gives a general account of the weather for 1893, which may be of interest to quote for comparison : — FAUNISTIC NOTES. 173 "The year 1893 was one of exceptional interest to the marine zoologist. During the first two months Plymouth experienced a continuous succession of heavy gales, l)ut towards the middle of March the winds became lighter, and the sea, which had been running remarkably high outside the breakwater, subsided. From that time onwards till the middle of September we enjoyed six months of the most delightful weather — a period, with scarcely a break, of calm seas and almost cloudless skies. Under the influence of the great heat the temperature of the Channel waters rose continuously, untU, in August, it had attained a point unprecedented for a quarter of a century ; and it was of the highest interest to observe the effect of this high temperature, and of the prolonged calmness of the sea, upon the floating population of the neighbouring portion of the Channel. Numbers of semi-oceanic forms which rarely reach our shores arrived in remarkable profusion. In June the tow-nets were crowded with salps, while towards the latter end of August they were almost choked by masses of living Eadiolaria." (p. 210.) On looking up my notes for 1893, I find that the fine weather first broke up on September 6th, with a south-westerly wind with squalls of rain. The sea remained rough until the 11th, then followed a period of fairly calm seas until September 28th, when bad weather again set in till the end of the month. During the latter half of September westerly winds usually prevailed ; rain fell nearly every day, and on two occasions showers of hail. REFERENCES Bles, E. J. (1892). — "Notes on the Plankton observed at Plymouth during June, July, August, and September, 1892." Jour. Mar. Biol. Assoc. New Series, vol. ii. pp. 340-343. Bourne, G. C. (1889).— "On a Toruaria found in British Seas." Jour. Mar. Biol. Assoc, vol. i. pp. 63-68. PI. vii. viii. Cunningham, J. T. (1892).—" On a species of a Siphonophore observed at Plymouth." Jour. Mar. Biol. Assoc, vol. ii. i^p. 212-215, and p. 398. Garstang, W. (1894).— "Faunistic Notes at Plymouth during 1893-4." Jour. Mar. Biol. Assoc, vol. iii. pp. 210-235. Garstang, W. (1894). — "On some Bipinnarias from the English Channel." Quart. Jour. Micro. Sc. vol. xxxv. pp. 451-459. PI. 28. Vallentin, R. (1891). — "Additions to the Fauna of Falmouth." Rep. Roy. Cornivall Polyiech. Soc. Edward T. Browne. Notes on the Pelagic Fauna at Plymouth. August-December, 1895. — The following notes are by no means exhaustive, or even complete, and merely indicate the more important features of the varied characters of marine life during the period covered by them. In their compilation I have followed the system of a monthly calendar adojited by Garstang (8). If these notes are compared with thoS(,' of other 174 FAUNISTIC NOTES. observers, certain differences present themselves, some striking, others trivial. That considerable and varied changes in the Floating Fauna do take place is suificiently obvious, and they are doubtless strongly influenced by conditions of climate and currents. Garstang (9) briefly deals with the inter-relations of the Plankton ; but very little accurate information on this point is available, and no explanation has yet been given of the periodic appearance and disappearance of certain forms. Thus, Xodiluca is recorded by Bles (1) as superabundant in 1891, scarce in 1892. Browne (7) comments on its abundance in 1893 ; Garstang (9) does not mention it for 1893 or 1894. I have only found a few in- dividuals in December, 1895, a season quite at variance with the notes of other observers. Mvgongia officinalis), a grade of little value. By far the most costly sponges in the market are those from the Mediterranean, the sheepswool sponges of the Bahamas and Florida being regarded as the next in quality. Of the latter, the Florida sponges are said to be superior to those sent from the Bahamas, being supposed to possess a somewhat finer texture, and a more regular and compact mode of growth. The irregularity of shape of the Bahama sponges is stated to be due to the irregular nature of the bottom on which they grow, f The method by which the sponges are procured in Florida is similar to that practised in the Bahamas, but differs essentially from the usual * The following account has been compiled, for the most part, from an article by Kathbun in "The Fishery Industries of the United States" (Section V. vol. 2, p. 819), published by the U.S. Commission of Fish and Fisheries, Washington, 1887. The discussion of the question by Dr. Juan Vilaro [Esponjicultura cuhunn, Revista do Pesca JIaritima VII. Madrid, 1891], was also consulted ; it is compiled chiefly from the American Reports. t The method of preparation of Bahama sponges is also stated to be inferior to that practised in Florida. 100 REPORT OX TIIK SPONGE FISHERY OF FLORIDA Mediterranean mode of fishing. In the latter case the sponges are generally obtained by divers from depths of from 15 to 20 fathoms, the men working without a diving dress, using large stones, which they hold at arm's length in front of them, to carry them to the bottom. They usually remain under water about two minutes. In America, on the other hand, sponges are taken in water of from 3 to 6 fathoms, or even shallower, by means of a three-pronged hook fixed at the end of a pole, men working the poles from small boats. The sponges are seen from the surface with the aid of a " sponge-glass," which is generally a wooden bucket painted a dark colour inside, and with the bottom replaced by a sheet of glass. When the glass is plunged below the surface of the water, the effect of the surface ripples is removed, and by looking through the bucket a clear view of the sea-bottom can be obtained even at considerable depths. As soon as a sponge is seen it is taken by means of the hooks. At the end of a day's fishing, the small boats, each of which is usually occupied by two men, return with their catches to the sponging vessel, which has been lying near all day, and the sponges are placed on board. Some of these vessels remain on the fishing grounds for from one to three months, whilst others return to port at the end of a week or fortnight only. It is generally usual, however, for the vessels to take their catch every week to the " crawls " — enclosures of stakes 8 or 10 feet square, situated in water 2 to 3 feet deep — in which the sponges are cured. The process of curing consists in allowing the animal portion of the sponge to rot, and then clearing it away by squeezing and beating. As much of the water as possible is pressed out, and the sponges then strung on rope yarns, and hung up to bleach and dry. The only other processes to which they are subjected before being placed upon the market are " liming " and trimming, but both of these are carried out after they have passed out of the hands of the fishermen into those of the dealers. The " liming " consists in dipping the sponges in a weak solution of lime in sea-water, and subsequently drying them, a treatment which adds to their value by giving them a bright yellow colour. This process requires to be very carefully performed, as too much lime is liable to injure the tissue of the sponge. When sponge-fishing was first practised on a large scale in Florida, only the larger sponges were taken, but in consequence of the amount of fishing which was carried on, the number of large sponges became insutticient to supply the demand, and the smaller ones were gathered to make up the re(|uisite quantity. It became evident, however, that the value of the grounds would soon become considerably reduced, and those interested in the matter began to consider the possibility of increasing the number of sponges by attempting their artificial AND THE ARTIFICIAL CULTURE OF SPONGES. 191 cultivation. Unfortunately, however, up to the present time, the matter does not appear to have been carried beyond a very elementary experimental stage. Sponge Culture Experiments. — The statement that detached sponges were capable of fixing themselves and continuing their growth, was first recorded in 1785 by Filippo Cavoliui, his account being based upon experiments carried out in the Bay of Naples. It was not, however, until the year 1862 that attention was drawn by Professor Oscar Schmidt to the fact that portions of a sponge would also fix and grow, and the possibility of its application to the produc- tion of sponges on a commercial scale pointed out. Experiments of Buccich. — In consequence of the opinion expressed by Professor Schmidt, " that if a perfectly fresh sponge is cut in suit- able pieces, and if these pieces, properly protected, are again placed in the sea, they will grow and finally develop into complete sponges," a number of experiments were made during 1863-1872, at a station established on the bay of Socolizza, at the north-eastern point of the island of Lesina. This establishment was closed in 1872, on account of the hostility of the native fishermen, who continually interfered with the growing sponges. An account of these experiments has been given by Dr. Emil von ^Marenzeller,* from the original notes of Signer Gregor Buccich, who was in charge of the establishment. The experiments seem to show that for European sponges cuttings, if carefully treated, can be reared successfully until they become of marketable size. Erom the account given, it appears that for making sponge-cuttings the most favourable time is during the winter months, as in cool weather there is less tendency for the sponges to suffer from detachment and exposure to air. The best localities are sheltered bays, with pure sea-water as free as possible from mud. The sponges from which the cuttings are to be made require very careful treatment, and the method finally adopted by Buccich was as follows : The sponges having been obtained either with tongs or a drag-net, and the injured portions, as far as possible, removed, they are fixed by means of wooden pegs to the inner side of a sort of fish-box, which is towed behind the boat. It is better, especially in warm weather, to leave the sponges for a little time in this box, in order to see whether or not putrefaction is likely to take place. "When it has been ascertained that all the sponges are healthy, the cutting and planting are proceeded with. The cutting is done upon a small board, moistened with sea-water, with a knife having a saw-edge, and the pieces are made so as to measure about an inch each way. * Die Aufzucht des Badeschwammes aus Theilstiifken. A''erhaiidl. dcr k.k. Zoologisch- botanischen Gesellschaft in Wien. Vienna, 1878. Translated in U.S. Fish Commission Report, 1879; p. 771. 192 REPORT ON THE SPONGE FISHERY OF FLORIDA Each piece should have as large an area as possible of intact outer skin. Various methods of planting the cuttings were tried. The pieces, especially those with only one cut surface, very soon attach themselves to a suitable base either of stone or wood, if brought into close contact with it. They must, however, in general be fastened in some way to prevent them from being moved about by waves and currents. Amongst other methods tried by Buccich was that of fixing the pieces by means of wooden pegs upon flagstones, in which holes were bored. But in this case the mud and sand on the bottom, and possibly also the excess of light, proved injurious. The apparatus finally adopted consisted of two boards, about 25 inches long and 16 inches broad, kept in a parallel position one above the other by two props placed at a distance apart of about 4h inches, and having their opposite ends fixed to the boards. Between the props stones could be put as ballast. Twenty-four holes, at distances of 4f inches from each other, were bored in each board, into which the two ends of as many bamboo rods could be fastened, thus forming a kind of vertical grating. Before, however, the bamboo rods were placed in position, the pieces of sponge were fixed to them in the following way : Three holes were made in each rod, at equal distances apart, and each piece of sponge was perforated with a hole sufficiently large for it to be able to slide on the rod. Three pieces of sponge were put on each rod, and supported on wooden pegs placed through the holes in the latter. In order to perforate the sponge-cuttings without injuring them, a trepan about a quarter of an inch wide, kept in rapid motion by a fly-wheel, was used. When the pieces of sponge had been fixed on the rods as described, and the rods placed in position in the frame, the whole was sunk to the bottom and allowed to remain. All wood used in the apparatus was well tarred, in order to prevent the destructive action of boring molluscs, and for this purpose it would be advisable, in any future experiments, to construct the apparatus of iron. It was found that if due care had been taken, 90 per cent, of the cuttings developed successfully, and Buccich states that they were found to grow two or three times their original size during the first year. He was of opinion that although some pieces will grow to a considerable size in five years, it would re' C. An interesting account of tlio Syrian divers is given ; besides useful details as to qualities of sponges, kc. NEW SERIKS— VOL. IV. NO. 2. ^ 200 I'KOJI'XTS FOR THE IMPKOVE.MENT OF SPONGE-FISHERIES. But if the transport were successful, and the sponges bred, it is very doubtful if any advantage would be gained. It must be regarded purely as an experiment in the dark ; and I can see no means of forecasting its result, or testing it in any way, but by its completion. If the difference between the sponges is a true racial difference, then the race from the Mediterranean might possibly prove stronger than the race of the Bahamas, and supplant it, though the fact that the climates are different is against considering this as probable. There is, however, grave doubt whether the dilference be due to deep-seated heredity. The sponges of America are considered no more than varieties of the Mediterranean species ; and Professor Hyatt is of opinion (5) that the difference in quality between American and European sponges is due to the higher temperature of the American water, and to the coral sand. My own experience in calcareous sponges points to most remarkable plasticity in response to changes of environ- ment, and it must be considered possible that, even if the imported sponges bred, their offspring would be indistinguishable from those always existing in the locality. C, Close time for Sponges. It is so common and so natural a tendency to consider the well-being of any fishery capable of improvement by the imposition of a close season, that it may be worth while recording simply that, according to F. E. Schulze (7), the toilet-sponge at Lesina breeds quite indifferently all through the year. Professor Schulze is the leader of all modern work on sponges, and his observations were made on a plentiful series of sponges supplied by Signor Buccich. PROJECTS FOli THE LMrROVE.MENT OF SPONGE-FISHERIES, 201 APPENDIX. Eate of Growth in Sponges. — According to T. Lee (12), the fishermen of Nassau say that the young sponge reaches marketable size three months after its attachment. Lamiral (3), in his scheme for acclimatisation on the French coast, stated that exhausted fisheries are regenerated in three years.* 0. Schmidt (6) "inclined to the opinion" that the growth of a self-sown sponge was no faster than that of one of his cuttings, which were found to take seven years to reach marketable size ; — it is noticeable that before the experiment he had expected quicker growth (Lc. p. 776). The Florida fishermen — v. Eathbun (11) — contend that "the Florida sponges grow much more rapidly, and reach a fair size within a comparatively short period." The Florida cuttings increased "to from four to six times their bulk" in six months, but this growth was actually effected in two months, as " fully four months elapsed before they recovered from the injury done them in the cutting." If this last be accurate, then a cutting of 2| cubic inches, growing to five times its bulk in two months, attained a volume equal to a hemisphere over 3 1 inches in diameter. Were it to proceed for the next two months at the same rate, we should have a hemisphere over 6 inches in diameter, which is more than marketable. Had the original 2^ cubic inches been produced at the same geometric rate, then a hemisphere of 1^ inches in diameter would have produced the six-inch sponge in six months. We have no right to assume this constant geometric ratio, nor to reason elaborately from inexact statements about amputated fragments; but putting these observations with the assertions of the Nassau and Florida fishermen, there seems a balance of evidence against assuming in these localities a period much greater than a year before the self-sown sponge becomes marketable. The Levant variety, discussed by M. Lamiral, lives where the atlas shows a mean annual temperature of about 7° F. below that of Florida, and the Adriatic variety, investigated by Professor Schmidt, at a mean temperature of about 7° F. lower still; we have no right to assume that the rates of growth are identical. But since in the Adriatic the same grounds are said (8) to be fished mercilessly, mature and immature, year after year,f there seems to be great presumption against Schmidt's estimate ; and this estimate was calculated from Buccich's cuttings, which I believe to have been unnecessarily * " On ignore quelle est au juste la duiee de la vie des Eponges et la vitesso de leur accroissement ; cepundant, des la troisieme annce, on peut revenir pecher dans les lieux ou elles avaient etc precederaent presque epuisees." — Lamiual, loc. cit. vol. viii. p. 329. t Probably based on Schmidt's own statement : " Man sucht in der schon beschriebenen "Weise dieselben Standorto Jahr fiir Jahr ab. . . , niclit uur die ausgewachsenen, sondern auch die kleineren Exemplare gcnommen werdcn." (Supplement der Spougion der Adria- tischen Meeres, 1864, p. 25.) At tlie time of writing the text I could not refer to Schmidt's original papers ; there is nothing to be added from them to the later account of his experiments given by Marenzeller. r 2 202 I'UOJECTS FOR THE IMPROVEMENT OF SPONGE-FISHERIES. injured by exposure to air, by the trepanned perforation, and by too close planting so as to choke each other. The much-needed observations on the natural growth of commercial sponges could probably be best made by observing the seedlings on a small marked area, artificially cleared. Single sponges fixed on stones could also have labels attached with silver wire, and be examined periodically. That the rapid period of growth suggested by the fishermen is not impos- sible, is shown by a few observations which have been made on calcareous and siliceous sponges. Vosmaer (9) calculated the giant Sycon on the oyster- frames to grow 1 to 2^ inches in length in a fortnight, and (10) found the bud of a Tethya in a month as large as its mother, ^ inch in diameter. Bowerbank (4) quotes H. Lee, that in the Brighton Aquarium Hymeniacidon formed in five months a crust 1 foot in diameter. Of this sponge and of Halichondria numerous large crusts may be observed in sjmng on the rocks near Plymouth Laboratory; they appear rarely to survive the summer, and Johnston (1) states that many allied species are annual. Carter (2) found Spongilla, at Bombay, grow over a surface two or three feet in circumference in nine months ; and states that specimens growing on straw in the water reached a thickness of half-an-inch in a few days, before the straw in the water had changed colour. The growth of horny sponges may easily be much slower than in these instances, but as yet I know of no reason to assume so. REFERENCES TO QUOTATIONS. 1. Johnston, G. (1842). — "History of British Sponges and Lithophytes," p. 92 and p. 124. 2. Carter, H. J. (1649).— Annals and Mag. Nat. Hist. pp. 95 and 96. 3. Laniiral, E. (1861-1863).— ^u/i. Soc. d'Acclim. Paris, vol. viii. p. 327 ; vol. ix. p. 641 ; vol. X. p. 8. 4. Bowerbank, J. S. (1874). — " Monograph of British Spongiadse," vol. iii. p. 339. 5. Hyatt, A. (1875 and 1877). — Mem. Boston Soc. Nat. Hist. vol. ii. quoted here from "U.S. Fish. Comm.," "Fishery Industries" (4to.), Sect. i. pp. 845, 846. 6 Marenzeller, E. von (1878). — Verhandlung der K. K. Zool. Bat. Gesellschaft in Wien, quoted here from translation in " U.S. Fish. Comm. Report " (Svo.), 1879, p. 771, et seqq. 7. Schulze, F. E. {1819).— Zeitschr. wiss Zool. vol. xxxii. p. 617 and p. 642. 8. Faber, G. L. (1883).— "Fisheries of the Adriatic," p. 96. 9. Vosmaer, G. C. J. (I88i).—Mitth. Zool. Stat. Neapel, vol. v. pp. 486 and 487. 10. Vosmaer, G. C. J. (1887).— "Bronn's Klass. u. Ord. d. Spongien," p. 440. 11. Rathbun, R. (1887).— " U.S. Fish. Comm., Fishery Industries" (4to.), sect. v. vol. ii. p. 832. 12. Lee, T. (1889).— "U.S. Fish. Comm., Report of Comm. for 1886," p. 664. 13. Browne, E. T. (1894).— Trans. Liverpool Biol. Soc. vol. viii. p. 45. It will be seen from this list how greatly I have been aided in com- piling these notes by the most valuable publications of the United States Commission of Fish and Fisheries. [ 203 ] Recent Reports of Fishery Authorities. The Scottish, Newfoundland, and United States Reports. By J. T. Cunningham, M.A. (1) Thirteenth Annual Report of the Fishery Board for Scotland, being for the year 1894. Edinburgh, 1895. (2) Annual Report of the Newfoundland Department of Fisheries for the year 1894, St. Johns, N.F., 1895. (3) Report of the United States Commissioner of Fish and Fisheries for the year ending June 30th, 1893. Washington, 1895. Artificial Hatching of Fish Eggs. — The Scottish Keport, whose title is given above, is stated to refer to the year 1894 ; but as a matter of fact, a great deal of the work recorded in it was carried out during the earlier portion of 1895. This is the case with the operations of the Dunbar Hatchery, described by Mr. Harald Dannevig, the ^Manager of that establishment. We find that 4-4,085,000 eggs of plaice were collected last spring, and from these 38,615,000 fry were obtained, and liberated in the sea. This shows a loss of only 12 per cent, in the process of hatching. But large as the numbers appear, it should not be forgotten that the above number of eggs represents the produce of only 220 female fish, reckoning 200,000 eggs to each, which is a low estimate, for it has been proved by Dr. Fulton that the larger female plaice produce each from 300,000 to 500,000 eggs in one season. It is, I think, interesting to consider, from various points of view, the proportion borne by the artificial hatching operations to the natural propagation of the fish in the sea. We have not at present ascertained approximately the number of females which spawn in the sea in one season, but we have some data concerning the number of mature females taken out of the North Sea, in one year, by the fishermen. According to Mr. Holt's statistics, which were very carefully collected, the number of mature plaice, over 17 in. in length, lauded at Grimsby 204 RECENT REPORTS OF FISHERY AUTHORITIES. alone in one year is more than 7,000,000 ; and as tliere are three females to two males, we may reckon that over 4,000,000 of these are females. We take, then, 4,000,000 of mature female plaice from the North Sea at Grimsby alone, not to speak of the numerous other trawling ports on the east coast of Britain, and in return we hatch the eggs of 220. The proportion here is one spawner in the hatchery for every 19,090 spawners killed at Grimsby. But next we have to take into consideration the superiority of the artificial process. We do not know what is the mortality of the eggs and fry in the period between fertilisation and the absorption of the yolk, under natural conditions. As we have seen, in the hatchery the mortality is only 12 per cent. Let us assume, for the purposes of calculation, that the loss is only 10 per cent, in the hatchery, and is 90 per cent, in the sea. Then we obtain nine times as many fry in the hatchery as in the sea from the same number of fish. It comes to the same thing if we say that one female spawner in the hatchery is equal to nine spawners shedding their eggs, without assistance, in the sea. We may say, therefore, that the work of the hatchery is equivalent to saving 9 females out of every 19,090 landed at Grimsby, or one out of every 2,121, or, in round numbers, one out of every 2,000. The disproportion would be very much greater if we took the total number of female plaice landed on the east coast of Britain. It seems to me beyond question, that if we regard the whole North Sea plaice fishery in this way, not taking the numbers caught by foreign fishermen into account, the results produced by the operations at Dunbar will be quite imperceptible. To diminish the destruction of mature fish even by one in every 2,000 in each year, could not make any appreciable difference in the general abundance of plaice in the North Sea. It must not be supposed that I have any prejudice against artificial hatching, or that I am unable to appreciate the skill and efficiency with which the Dunbar establishment has been organised and operated. On the contrary, I think that Dr. Fulton and Mr. Harald Dannevig deserve great credit for the energy and ability they have exhibited in the working of the first British hatchery for sea-fish, and for the success they have obtained. No harm, but only good, can result from an honest and strictly accurate calculation of the possible results. The evidence available from other enterprises of the same kind tends to show that quite obvious local results have been produced by the liberation of large numbers of fish-larvro in the sea, and although, as the above calculations show, we cannot expect to perceive any increase in the general plaice production in the North Sea, in consequence of the work at Dunbar, it may be quite possible to recognise on particular local grounds an increased abundance of marketable plaice, derived, RECENT REPORTS OF FISHERY AUTHORITIES. 205 with reasonable probability, from the fry liberated from the hatchery. We cannot, however, admit the correctness of certain calculations con- tained in the official general statement of this Report. These are, tliat if one in a hundred of the fry distributed from the hatchery survived, and were worth sixpence each, the resulting value to the fisheries would be about £18,000, and that it would recj^uire the survival of only one in a thousand, in value one penny each, to cover the expenses of the work. Fish in the sea have clearly no value, and we cannot hope to catch all of them. It is difficult to say whether a quarter, a half, three-quarters, or what proportion would be caught; but even when they were caught and sold, their value could not be all applied to defray the cost of hatching, because the greater part of it, as usual, would go to defray the cost of catching and marketing. Such calcu- lations would only be applicable to fish that were reared entirely in confinement, like chickens or pigs. The importance of the working of a marine hatchery at the present time, and on the comparatively small scale of that at Dunbar, may be reasonably held to be, not in the immediate utili- tarian result to be derived from it, but in its value as a sufficiently extensive experiment in the open. We have reached a certain point in laboratory research and experimentation. We have discovered enough concerning the life-histories of food fishes, and their place in nature, to obtain glimpses of the possibility of a more scientific and more profitable exploitation of the products of the sea than that w^hich is now practised. To convert these glimpses into comprehensive perception, we require more investigation and experi- mentation under the open sky, and on a scale commensurate with the extent of the regions to be exploited. Thus the managers of a hatchery ought not be content with proclaiming the millions of fry they have liberated, but should ascertain what ratio these numbers bear to the number of fry naturally present in the region where they are placed, and should make every endeavour to trace their future history. In this Eeport Ur, Fulton gives the result of some very valuable experiments he has made, as to the effect of the currents on the east coast of Scotland, on bottles floating level with the surface. These results show that buoyant objects at the surface are carried southward and east- ward to the neighbouring shore. One or two of these bottles were found ultimately on the German coast, near Heligoland. The fry from the hatchery were liberated at the mouth of the Firth of Forth, and in St. Andrew's Bay, and according to the direction of tlie drift, ascertained by the experiments just mentioned, the survivors should be found chiefly on the southern shores of the Firth, and further south-east towards Berwick. It will probably turn out, therefore, that the 20G RECENT REPOIiTS OF FISHERY AUTHORITIES. iufluence of a hatchery is confined for the most part to a comparatively limited neighbourhood, and it ought to be possible, if the necessary data are accurately observed, to ascertain the magnitude of its inlluence within these limits. Comparisons should be made between the natural propagation of the fish, and the artificial propagation within the limits thus set by natural conditions. Hitherto they have not been made, and the necessary observations have not been carried out. The results would doubtless be more favourable than those of the comparison above made between the operations of one hatchery and the Grimsby fishery. In the Newfoundland lleport for 1894 it is stated that the number of cod eggs treated at the hatchery, on Dildo Island, Trinity l>ay, in that year, was 346 millions, from which 221i million fry were obtained and liberated. This is a survival of 64 per cent., or a loss of 36 per cent. The number of cod fry liberated was, therefore, nearly six times as great as that of the plaice-fry produced at Dunbar. But it must be remembered that the cod normally produces a much larger number of eggs than the plaice. According to Dr. Fulton's calculations, the number in the cod varies roughly between three and six millions. If we take four millions as a moderate average, the above number of eggs is the produce of only eighty-six female cod, so that from this point of view the work of the Dunbar Hatchery on the plaice was really of greater magnitude than that of the Newfoundland Hatchery on the cod. The efficiency of the treatment was considerably greater at Dunbar, that is to say, the loss or mortality during the treatment was much less in the Scottish establishment. But at Dildo Island the number of eggs collected was so large that there was not room for all of them in the hatching apparatus, and the excess was utilised by being placed in linen bags, suspended in wells, in the wharves outside the hatchery. This may to some extent account for the greater percentage of loss. As evidence of the successful results of the hatching operations in Newfoundland, it is stated that in the beginnins of the summer of 1894 there was a great abundance of cod of various sizes and ages in Trinity Bay, and none in the neighbouring Bonavista and Conception Bays, where the season's fishery turned out very poorly. The liberation of fry has been carried out annually since 1890 in Trinity Bay only, and it is maintained that the cod found in large numbers in that bay in 1894 were derived from the fry deposited. It is stated that the cod one year old were most abundant, next to these in numbers were cod of two years, and then the three-year-old fish, with a fair proportion of still older and larger fish. This is in accordance with the continual increase in the number of fry liberated each season since 1890. In the Newfoundland Ileport for 1892 it is pointed out by Mr. RECENT REPORTS OF FISHERY AUTIIORITIaS. 207 Nielsen, who conducts the hatching operations, that the idea that if the fish were not artificially treated they would propagate in the natural way, is a mistake. All the spawners are caught in the neighbourhood of the hatchery, and if there was no artificial hatching just as many fish would be taken, and no living fry would be returned to the sea from them. We here come upon the same question which was indicated above, in reference to the Dunbar Hatchery, namely, what proportion exists between the number of spawners artificially treated, and that of those which spawn naturally in the same district. Evidently Mr. Nielsen's view is that the capture of adult fish is so great that very few are left to shed their spawn, or, at any rate, such a small number that the number of the fry derived from them is small in proportion to the number of fry liberated from the hatchery. "We cannot deny that the evidence given of the great increase in the number of adult cod, following directly upon the liberation of millions of fry from the hatchery, gives strong support to Mr. Nielsen's contention. But in this, as in other cases, we ought to be supplied with other important evidence, perhaps the most important being a direct determination of the number of cod eggs actually present in Trinity Bay, during the spawning season of the cod, in order that we may compare this with the number of eggs treated artificially in the hatchery. In Newfound- land, as in Norway, it has been observed that an increase in the supply of cod has followed upon artificial hatching. But in regard to all such evidence the vastness of the numbers put forward, and the absence of accurately observed data for comparison, tempt one strongly to adapt a well-known phrase and say, "c'est magnifique, mais ce n'est pas la science." The operation which is stated to produce such successful results, is that of placing so many million living fry in the sea at the stage at which the yolk has just been all exhausted. Surely it is not impossible, or even difficult, to ascertain how many such fry were in the sea already, without the operation. Until this or similar facts have been ascertained, it cannot be said that the process of artificial propagation has been put on a practical basis. However, notwithstanding this criticism, it must be admitted that local benefit from artificial propagation appears to have been produced. This leads to some further interesting considerations. It is well-known that the Scottish Fishery Board have closed certain inshore areas to beam-trawling. In these areas there appears to be no kind of fishing carried on which involves the destruction of young plaice or the young of other flat fishes on a large scale. The abundance of the fiat fishes in these closed areas has been examined annually since 188G, with great statistical accuracy, by means of experimental trawlings carried out by the Board's steamer Garland. Notwithstanding the protection, 208 RECENT REPORTS OF FISHERY AUTHORITIES. the number of plaice and other flat fishes has not increased: it has fluctuated from year to year, but never maintained a steady increase. The number per haul of the trawl has also not increased in the open area. * It seems reasonable to infer that the reduction of the number of spawners on the open grounds, by the great extension of the trawling industry, is so great that protection of the young fish is not sufficient to compensate for it. With food-fishes, as with oysters, we are apt to attach so much importance to the number of ova produced by each female, that we overlook the importance of the number of females. It is of course true that if we could save a larger proportion of the progeny of a few parents, we should obtain a large number of fish or oysters. But, on the other hand, it may be, and experience indicates that it would be, more practicable to obtain our object by preserving a larger number of parents. In the case of oysters more success has been secured, as Mr. Bashford Dean has pointed out, by maintaining a very large reserve of parents, than by trying to preserve a larger pro- portion of the progeny. One method of doing this with sea-fishes would be to create reserved and protected spawning grounds. But there are objections to this method : there is the difficulty of protection, and also the fact that the fish will wander away, and be caught on other grounds. Now it is possible to regard the hatchery, as at present worked, as simply a reserve of spawners. No matter how many spawners may be taken from the sea, those in the hatchery are safe, and will supply their annual quantum of eggs or fry. But to carry out this principle effectively it would be necessary to keep in confinement, not hundreds but thousands or millions of spawners. We should have to maintain a number bearing some significant proportion to the number which now survive to spawn in the sea. It is conceivable that if spawning fish were maintained in confinement all along the coast in sufficient numbers, we might depend for our fish supply almost entirely on the eggs and fry derived from those. It may be that this will be the ultimate solution of the problem of replenishing our exhausted fishing grounds. In the meantime, although it seems wonderful to read of hundreds of millions of fry placed in the sea, as a matter of fact we are dealing, as I have shown, with only a few hundred spawners, while thousands upon thousands are being annually captured. * The following are the average numbers of fish taken per shot of the trawl, in two periods of four years : — Closed Area. Open Area. Flat Round Flat Round fish. fish. fish. fish. 1886-89 178-5 .. 77-8 91-2 ... 86-4 1891-94 120-9 .. 89-9 77-G ... 102-5 RECENT REPORTS OF FISHERY AUTHORITIES, 209 In the American Commissioner's Eeport (p. 72), we find a section devoted to the description of "Some Results of Acclimatisation." The most important of these results is the successful introduction of the Atlantic shad {Clupca sapidissima) to the waters of the Pacific coast of North America. The supply of shad on that coast, we are told, continues to increase, and is now so great that the retail price of the fish there is actually less than on the Atlantic coast. The shad has within a few years not merely been successfully introduced, but has permanently established itself, and become one of the cheapest fish of the region. It must be noticed, however, that this is not, properly speaking, a success to be placed to the credit of the system of artificial propagation. It is true that the introduction was effected by the transportation of artifi- cially hatched fry from hatcheries on the Atlantic seaboard, and their liberation in Pacific waters. But the abundance of the fish in the Pacific States is due to its own natural multiplication in its new habitat, not to its continued artificial propagation there, and the same success might possibly have been obtained if a sufficient number of adult fish had been placed alive, and in healthy condition, in the rivers of the Pacific slope. The transportation of the minute fry may have been easier than that of the adult fish ; perhaps, indeed, the latter operation would not have been possible at all. But even if this were so, the artificial hatching of the fry, in the first instance, was only a detail in the process of transportation and introduction, and artificial propaga- tion has not been carried on subsequently in the new habitat, and therefore has had nothing to do with the subsequent increase in the supply, any more than artificial breeding has had to do with the trouble- some multiplication of European rabbits in Australia. The introduction of shad fry to the rivers of the Pacific States was first attempted in 1871, 24 years ago, when 12,000 of them were liberated in the Sacramento Eiver. From that year until 1886 609,000 fry were liberated in the Sacramento, 600,000 in the Williamette Paver, 300,000 in the Columbia Kiver, and 10,000 in Snake Piver. Nothing is said of any planting of fry after the year 1886. The catch of the fish in 1892 was estimated at 700,000 lbs., having a value to the fishermen of £4000. But, probably in con- sequence of thinness of the population, the demand for shad in the west seems very slight, the price in 1892 being 4 cents, or 2d. a lb., and the fish being only incidentally taken in nets operated for salmon, or other fish. This fact has, doubtless, an important bearing on the increase in the abundance of the shad. The remarks I have made show how completely illogical, in my opinion, is the argument contained in the following sentence, quoted from the Peport under review : "If these far-reaching and no doubt permanent results attend the planting on few 210 RECENT REPORTS OF FISHERY AUTHORITIES. occasions of small numbers of fry, in waters to which the fish are not indigenous, is it not permissible to assume that much more striking consequences must follow the planting of enormous quantities of fry year after year, in native waters ? " The history of the introduction of the striped bass {Roccus lineatus) to the same region adds strong support to my argument, for this intro- duction was altogether independent of artificial propagation. In 1879 about 150 specimens, a few inches long, taken in Shrewsbury Eiver, New Jersey, were carried across the Continent and liberated at the mouth of Sacramento Eiver ; in 1882, another lot of 300 fish was transported to the same region. As a result of these two small deposits the species became distributed along the entire coast of California, and the catch in 1892 was about 43,000 lbs., for which the fishermen received somewhat more than £1,000. The operations of the U.S. Commission for the year, in the propaga- tion and distribution of fish, are recorded in the Eeport in great detail, but only a few points need be mentioned here. The discussion of results is not attempted in this section of the Eeport. The propagation of marine fishes is still conducted on a rather small scale. At Gloucester Station, Mass., 49 million cod eggs were obtained, and 20 million fry produced and liberated. At Woods Hole cold killed the spawners, and only 2,883,000 cod eggs were obtained, from which 850,500 fry were produced. Lobster eggs were also hatched ; and mackerel, sea-bass, and flat fish on a very limited scale. Of shad 31 million fry were hatched at Battery Island Station on the Chesapeake, about 7 million on the Delaware, 5h million at the Central Station, a total of 43| millions. Thus, the number of fry obtained was only a little greater than that of the plaice hatched at Dunbar, and little more than one-fifth of the number of cod-fry hatched in Newfoundland. But, on the other hand, the number of eggs per female shad is given as 45,000, and the number of eggs obtained was 74,150,000, so that 1,647 females were stripped, and from this point of view the propagation of shad in the United States, is on a larger scale than that of plaice or cod in Scotland or Newfoundland. Investigations. — As usual, a considerable amount of research is described in the Scotch Eeport. Dr. Fulton has added another series of experiments to those which have been carried out on the Garland, by his instructions. In this case he has had an equal number of hooks of different sizes fitted on one long line, and the line has been shot, in order to see whether the larger hooks caught fewer small and immature fish. The fish caught in largest numbers were of course haddock, and although the proportion of mature to immature fish was RECENT REPORTS OF FISHERY AUTHORITIES. 211 greater with the larger hooks, still this advantage was not sufficient to compensate for the great general reduction in the number of fish caught. Small hooks catch a large proportion of large fish, and large hooks a considerable proportion of small. Of Prof. Mcintosh's additional contributions to the knowledge of eggs and larvre, perhaps the most interesting is that concerning the turbot. The material in this case was derived from the mature living turbot, collected at the Dunbar Hatchery. In the summer of 1894, these turbot, although gravid, did not spawn. On the 7th September a specimen was examined, and in the centre of the enlarged ovary was a large space filled with mucus and the remains of ripe, but dead, ova. The fish were evidently, it is stated, getting rid of the eggs of the season which had been retained in the ovary, and died there. This is exactly what I described years ago, in this Journal, concerning the sole in the Plymouth tanks. Prof. Mcintosh thinks that the egg- bound condition, i.e. the refusal to shed the spawn in a normal manner, is voluntary, and that it would soon disappear when the fish grew accustomed to confinement. It is quite probable that the turbot would shed its spawn in confinement after a time, but in the Plymouth Aquarium the soles did not spawn till after five or six years, and the turbot has not spawned there yet. At Dunbar, the soles and turbot collected in 1894 were unfortunately lost from overcrowding, in con- sequence of the limited capacity of the ponds ; and in 1895 the fertilised eggs from other turbot which were obtained, were artificially stripped from the fish. Mr. Arthur T. Masterman has two papers in the Scottish Peport, one on the rate of growth of plaice, and one on hermaphroditism iu the cod. The former paper consists largely of comments on Petersen's work and my own; those on the former being complimentary, those on the latter very much the reverse. As he bases his comments largely on theoretical assumptions, I do not think it necessary specially to defend my own work. Mr. Masterman's own contribution to the evidence concerning the growth of plaice consists in the application of Petersen's method of graphic curves to the measurements of plaice taken on the east coast of Scotland by the Garland. The curves obtained, especially those of plaice taken in St. Andrew's Bay in 1891, do give successive maxima in the number of individuals at certain sizes, but that these maxima correspond to the broods of successive years seems to me more than doubtful. Thus, according to Masterman, the mid-size of the year old fish in July is 6 in., of the two year old 8Hn., while in November the mid-size of the year old fish is 9i in., and even iu October is 9 in. That is to say, the majority of the year old fish grow 3 in. in length in the three mouths, July to October, but only 212 RECENT REPORTS OF FISHERY AUTHORITIES. 2^ in. in twelve months. Another objection is tliat, according to Masterman, the plaice of 13 in. mid-size are in July in their fourth year ; although it is known that plaice on the east coast of Scotland are at that size, with few exceptions, immature, while three-year-old plaice are nearly all mature. It is true that Masterman only urges that by the method, with a proper series of observations, valuable results might be obtained ; and if we could explain away the cusp of the curve for July at 6 in., the two cusps at 8^ and 13 in. would represent the plaice in their second and third years, a result which would agree with my own conclusions. In his second paper Mr. Masterman describes two hermaphrodite specimens of the cod, and discusses their condition in relation to hermaphroditism in general. In the course of his remarks he refers to "Nansen's observation of the protandric hermaphrodite condition of Mijxine," apparently in ignorance of the fact that Nansen's description of that condition was a confirmation of my previous discovery. This is the second time that my discovery of the hermaphroditism of Myxine has been attributed in a Eeport of the Scottish Fishery Board to ISTansen. On the former occasion the error was corrected, not by myself, in the columns of Nature. If ]\Ir. Masterman had consulted my paper he would have found that the habits of the hag-fish were more definitely known than he seems to suppose. It should be mentioned that the Eeport of the United States Com- missioner, whose title is given at the head of this article, is merely the report proper, without the appendices, which were issued previously, and which contain detailed accounts of many of the investigations mentioned in the general report. This general report consists of four parts — the Commissioner's own statement, and three divisional reports, one on the division of investigations by Kichard Eathbuu, one on the division of statistics and methods, and the third on artificial propagation and distribution. Eeference to interesting points in the last two divisions has been made, and it remains to mention the character of the investigations carried on by the Commission in the year 1892-93. In 1892 the Albatross was employed by the United States Government in investigations of the seal and seal fisheries of the Behring Sea. From August, 1892, till April, 1893, she was under repair at San Francisco, after which, by direction of the President, she joined the fieet which was employed in patrolling the North Pacific and Behring Sea. The naturalists belonging to the ship remained with her, except when she was under repair, and carried on observations concerning the seals, and the fishes of the places visited, as opportunities occurred. On December 6tli, 1892, an agreement was concluded between the RECENT REPORTS OF FISHERY AUTHORITIES. 213 Governments of Great Britain and the United States, which provided for the appointment of a joint commission of two experts, one on behalf of each Government, to report upon the fisheries in the territorial and contiguous waters of the United States and Canada. The reports were to be presented within two years, and the object in view was the recommendation of practical and administrative measures to be adopted by both authorities. The two Commissioners appointed were Mr. Eichard Eathbun and Dr. William Wakeham, and their investi- gations during the time covered by this report were confined to the mackerel fishery. Various other investigations, such as the survey of oyster beds in Chesapeake Bay and Galveston Bay, the study of the lobster by Professor Herrick, at Wood's Hole, the discovery that the tile-fish had returned to the Continental slope, south of New England, with the return of warm water to that region in consequence of a change in the interaction of the currents, are mentioned, but the full description of them is to be found in special papers. The Fourth Report of the Danish Biological Station. By F. B. Stead, B.A. The Plaice in Danish Waters. — The Fourth Eeport of the Danish Biological Station consists of a lengthy paper by Dr. C. G. J. Petersen " on the Biology of our Flat-fishes and on the Decrease of our Flat-fish Fisheries," which was awarded a prize by Det Kongelige danske Vidensl'oberncs Selskab, and which certainly deserves the careful attention of all who are interested in fishery questions. The first chapter gives a fairly complete account of some of the main features in the life history of the plaice in the Danish seas, together with shorter notes on other flat-fishes ; the second and third are occupied by a discussion of the reasons for the deterioration of the fisheries, and of the remedial measures by which this evil may in the future be prevented. The paper is supplemented by five appendices, one of which, on the post-larval stages of flat-fishes, is of particular interest. For the full English translation with which we are provided English naturalists can but express their gratitude to the author. The first question to which our attention is drawn in this })aper is that of the variations in size, which plaice from different localities 214 Recent reports of fishery authorities. are found to exhibit.* These differences are seen on comparing the average sizes of plaice which have just arrived at maturity, and also the average sizes of mature (grown-up) plaice {i.e., three years old and over) from different localities. Thus while in the Baltic the average size of mature plaice is about 10 inches, it is 11 inches in the Lesser Belt, and 12-13 inches in the Cattegat. Whether this gradual decrease in the average size of the mature fish, as we pass from the Cattegat to the Baltic, is due to a corresponding gradual change in the conditions favourable to growth, or whether it implies a migration of the larger plaice from the Baltic towards the Cattegat, is not certain, but there are reasons for thinking that the plaice of the Baltic do not enter that sea in any numbers till they are one year old, so that to speak of a race of plaice peculiar to the Baltic would be erroneous. Further, as we pass from the German Ocean to the Baltic, there is a gradual decrease of the size at which plaice become ripe for the first time. If to these differences others {e.g., in the number of fin rays) be added, the existence of separate races is still unproved. For seeing that the eggs and fry of all the plaice are pelagic, and must in consequence all be mixed together, the appearance of one form of plaice in the Baltic and another in the Cattegat, must be due either to the ftict that the eggs of one form cannot live when carried into the territory of the other, or that the differences between the two forms are wholly ontogenetic. Of these two alternatives our author is inclined to accept the second. Perhaps the most interesting part of Petersen's paper is that in which he describes his method of determining the rate of growth of plaice. By fishing at any given time of year in a number of different places, at different depths, and with nets of various kinds, and measuring all the fish caught, Petersen found that the fish were grouped about certain maxima corresponding to the most common lengths of the fishes born in successive years. These groups he calls the " 0 group," consisting of fish less than one year old, the " 1 group " between one and two years old, the " 2 group " between two and three years old, and the " 3 group " consists of fish three years old and over. Leaving for a moment the question of how far this method of determining the rate of growth of the fish, and the probable age of any particular individual, is a sound one, we may pass on to a brief resume of the life history of the plaice in Danish seas as traced by Petersen. The spawning season lasts from November to April, with a maximum in January and February. The larvae, so long as they retain their yolk sac, are 6-7 mm. long. " When the yolk sac is absorbed, and the fish have become unsymmetrical and compressed, with their left eye sitting * Cf. Cunningham. "North Sea Investigations" — this Journal, vol. iv. nos. 1 and 2 ; especially no. 1, pp. 23-2.'), and no. 2, pp. 97-lOS. RECENT REPORTS OF FISHERY AUTHORITIES. 215 nearly on the edge of the brow, but while they are still transparent pelagic fish, they are 10 to 12 mm. long." The length at which the metamorphosis is complete, appears to vary from 10 mm. to 13 mm, Petersen was unable to find the young plaice of 12 mm. before the month of May, and concludes that the larvti; hatched in November take six months to pass through their pelagic stage. The same does not hold, however, for the turbot, the brill, the flounder, and the sole, in all of which the spawning season begins later than in the case of the plaice. Further, the young plaice of 12 mm. in length are always found close in on the shores, and never in water of two fathoms and over. From this fact Petersen draws the conclusion that of the pelagic fry in the sea only those which happen to be near the shore at the time when metamorphosis takes place can survive. It is the physical conditions then, and not the presence of enemies, which causes that enormous destruction of larvoe which undoubtedly takes place. The young fish belonging to the "0 group," which have all reached the length of 12 mm. by the month of May, grow to a length of 2—4 inches by the following autumn. In the succeeding winter they cannot easily be found on the shores, and it is suggested that they bore down deep into the sand where the seine cannot reach them. By the end of their first year the young fish migrate into deeper water, and this migration probably begins in the winter months. An investigation made at Aalbek in July, 1893, showed that the plaice were larger the deeper the water examined. Summarising the results of this investigation it was seen that besides the " 0 group," which were found in water of less than 2 fathoms, there was a "1 group" from 2i-2 inches at 5 fathoms, and a " 2 group" from C|-10 incbes, which began to appear in water of 8 fathoms. The different groups are not, however, found in all the seas. On the contrary, while as we have already seen, the " 0 group " is entirely absent from the Baltic, the plaice in their second and third years are present in considerable numbers. The largest specimens (14 in.) found in the Baltic, probably represent the 3 group, and the size at which the 2 group meets tlie 3 group, is set down at 8 to 9 inches. On the other hand, fish of 3 years old and over are not found in the Northern Cattegat in any numbers "without much searching"; and it seems clear that owing to persistent over-fishing there has been in recent years a decrease in the size of the plaice caught in the Cattegat, As Petersen remarks in pathetic italics, "they do not get time in the Cattegat " — cut off, as it were, by ruthless fishermen before they attain their prime ! The fact that the " 3 group," which is almost absent from the Cattegat, and but poorly represented in the Baltic, is found in the NKW SERIES — VOL. IV. NO. 2. Q 216 KECEXT EErORTS OF FISHERY AUTHORITIES. intervening seas, has suggested tlie view that an emigration of three- year-old plaice takes place from the Baltic. Turning now to the question of the accuracy of the method employed for determining the rate of growth of fish, it seems clear that while the existence of the natural groups, each varying about a most common length, correspond to the average size of fish of tliat age is clearly shown ; a reference to Petersen's tables leaves the impression that considerable uncertainty exists as to where one group ends and another begins, and as to the exact position of the most common length for each group. And this is practically admitted, when the remark is made that " besides distinguishing the sexes, we ought also properly .... to fish the same number of specimens of each annual series, in order not to efface the boundary lines between them." How can we be sure that this is done ? * Tn cases where fish of all the different ages can be fished " in one draught" the difliculty is no longer present. It was mentioned above that plaice less than 1 year old were not found in the Baltic. Hensen has, however, shown that the eggs of the plaice are found there ; and the absence of the young fish is accounted for by the peculiar hydrographical conditions which obtain in that sea. For experiments made by I'etersen, in Copenhagen, on living plaice eggs, proved that the highest specific gravity at which all the eggs sank was 1'0120 10° C, corresponding to a salinity of 1-44 per cent. ; and Hensen's investigations prove that '^almost every month there occurs such a low salinity that the eggs must sink to the bottom." If, as is probable, the eggs, on sinking to the bottom, are killed, the absence of the young fish is clearly accounted for. The same does not, however, hold for the turbot, the brill, or the flounder. The fry of these fish are sometimes met with in multitudes on the shores of the Baltic, while in the Cattegat young flounders are found in company with young plaice. AVith regard to the turbot and the brill the explanation given is that the pelagic fry of these fish are more hardy than those of the plaice, and so can live in water of a lower salinity. With regard to the food of plaice of different ages a short summary of the main facts is given by our author. Thus, during the pelagic stages the food consists chiefly of copepods; and even when the fish have grown to 1\ to 1 ^ inches, " Co23epoda, Cladocera, Ostracoda, and the larvcv of bivalves" may form their food. At a length of 2 in. to 3 in., however, the diet has changed, and now consists of Idothea, Gammaridce, smaller Annelida, and the fry of bivalves." When the fish have grown to a length of 3 to 5 in., " they [• Cf. for a more detailed criticism of Petersen's results Cunningham's paper in this number of the Journal pp. 136-138.] RECENT KEPOKTS OF FISHERY AUTHORITIES. 217 take in the main the same sort of food as the older plaice," and after the end of their first year there is no change in the character of the food of the plaice. We may now pass on to our author's discussion of the economic question : how may the plaice fishery be prevented from further deterioration? We may say at once that Petersen is in favour of the imposition of a size limit, but for reasons somewhat different from these commonly given in support of this proposition. He points out that the object to be kept in view is to make the fishery yield as large a profit as possible. It is necessary, therefore, to allow the fish to grow to such a size, that the largest possible weight of fish involving the highest selling price can be obtained. Now, a plaice of 10 iu. weighs less than Mb., and one of 14 in. more than twice as much: it follows that, unless in the time that it takes 10 in. plaice to grow to 14 in., the mortality is such as to reduce the population of these plaice to less than half its original number, the total weight of the plaice at 14 in. will be greater than at 10 in. It is not likely that the death-rate is as high as this, because the plaice does in fact grow to a much larger size than 14in. ; further, it would seem that disease is almost unknown among these fish : and their enemies are apparently few. Hence, by allowing the 10 in. plaice to grow to a larger size before capturing them a greater profit will be obtained. There will of course be a limit of size beyond which it will not be profitable to allow the fish to grow, and this limit will depend on the death-rate at each size. Our author contrasts his view, which he calls the "growth theory," with the " propagation theory " of other writers. Those who hold this latter view insist on the necessity of increasing the 7mmher of in- dividuals, and, in recommending a size limit, are happy if they can secure that the fish shall be allowed a chance of spawning. Petersen, on the other hand, thinks it of more importance to allow the fish to grow to the size at which they will yield a maximum profit, and holds that ample provision is made in nature for keeping up the numbers. As his point of view is an important one, and as it is stated with great clearness, I do not hesitate to quote him on this point in extcnso. " It has always been hard for me to believe that there should be any want of eggs of plaice in our seas, partly because Hensen's excellent investi- gations have shown what immense quantities there are of them, partly because 1 myself see our seas filled with such eggs. Nor have I ever been able to believe in any want of young plaice. . . . Nay, everything seems to me to indicate that it is not in the heginniny, but in the middle and end of the life of the plaice that wo must look for the injury ; for it is here that man interferes as a troublesume 218 RECENT REPORTS OF FISHERY AUTHORITIES. factor."* And again, "If we fisli the plaice while they are small, we do not get so great a profit from them as we might and ought to have. In this only, so far as I can see, the ' destniction ' consists." \ It is of interest to notice that the view here set forth appears also in the discussion on the desirability of a close time for crabs and lobsters. I And if it is assumed for any species — (1) that the provision made in nature for keeping up the numbers of individuals is more than sufficient, and (2) that owing to 7iatural inlluences, the number of surviving groivn-up individuals is fixed and relatively small, then it will follow that the continual destruction caused by man must of necessity lead to a decrease in the number of large individuals, and that this decrease cannot be met either by artificial propagation, or by the imposi- tion of a small size limit. These two assumptions appear to me to underlie the view which our author puts forward as the "growth theory"; and the first of them implies that there is, under natural conditions, an excessive wasteful production of young fish. Our author further points out that, in respect of the plaice, both theories will lead to a similar practical conclusion — the imposition of a size limit; though the effective size limit, from the point of view of the "growth theory," will be higher than that which is required by the "propagation theory." This, however, does not hold good in all cases. The eel-fishery, for instance, consists wholly in the capture of eels which have never spawned. " The propagation theory would be obliged to require a size limit of at least 20 inches, in order to protect the stock of eels satisfactorily; hut then the males could not he cauf/ht at all."^ The growth theory, on the other hand, would be content with a lower limit. It will be seen that the questions raised by the discussion of these different theories are of great practical importance. They are among the scientific problems which call for settlement, before sure guidance can be given to the legislator. * Loc. cit. pp. 61, 62. {In all quotations the italics are Petersen's.) t Loc. cit. p. 57. + Cf. p. 186, this number of Journal, answers of fisherman to cross-examination by Messrs. Pannett and Mally. § Loc. cit. p. 82, footnote. [ 219 ] Director's Report. The investigations into matters connected with economic fishery- questions have been carried on with considerable success, during the summer and autumn months. Mr. J. T. Cunningham has visited various fishing centres on the East Coast, and has been able to supple- ment the observations made by Mr. Holt and himself at Grimsby, in some important respects, by thus extending the field of investigation. As will appear from the full report published by Mr. Cunningham in this number of the Journal, he has, amongst other things, shown that two distinct races of plaice occur in the North Sea. It had already been ascertained that the plaice of the English Channel formed a smaller race than those generally landed at Grimsby from the North Sea. The evidence now obtained from Lowestoft proves that the plaice brought to that port from the Dutch coast, south of the Texel, are no larger than those of the English Channel, so that the high size limit proposed to be applied to the plaice landed at Grimsby would be quite inapplicable to those landed at Lowestoft. Mr, F. B, Stead has commenced an investigation of the fish which inhabit the bays on the South Coast of Devon, at present closed to trawlers. The results of this investigation promise to be of great interest. Erom the facts at present ascertained, it appears that during October and December, the only fish which are taken in these bays in sufficient numbers to be of importance, from a practical point of view, are plaice and dabs. Of these two species, the plaice only are valu- able, and the large number of competing dabs must probably be regarded as a positive hindrance to their well-being. Any controversy that may be raised, therefore, as to the advisability or otherwise of keeping these bays closed to trawlers, should be solely occupied with the consideration of the question whether such closure is necessary or desirable for the protection of plaice. It has further been shown that the bays differ markedly from one another in respect of the sizes of the fish they contain, for whilst half the plaice in Start Bay were found to be over 12 J inches in length, in Teignmouth Bay half the plaice captured were under 10^ inclies, I have given, in another part of the present number of the Journal, a brief account of the investigation which is being carried on into the Q 2 220 director's report. fauna and flora of the outlying grounds between the Eddystone and Start Point. It is proposed, during the next six months, to dredge over the same grounds again, in order to confirm the results already arrived at, and to fill in the many gaps which at present exist in the rough cliarts that have been made. The naturalists who have occupied tables at the Laboratory, since the publication of the list in my last Eeport, are : — E. T. Browne, b.a., August 19th to September 30th (Medusce). G. Brebner, September 5th (Marine Algoc). S. D. Scott, B.A., September 16th to October 5th (General Zoology). A. H. Church, b.a., December 17th to December 25th (Marine Algm). E. H. Chapman, December 28th to January 20th (General Zoology). T. H. Taylor, m.a., January 6th to 10th (Polyzoa). Of the gentlemen whose names appeared in the previous list, Dr. Bethe remained until the middle of October, and Messrs. Eiches and Bidder until December, so that the number of workers at the Laboratory during the later months of the year has been somewhat larger than usual. It will be noticed that two naturalists have been engaged in the study of marine alga3. It is some time since botanists have taken advantage of the facilities afforded at the Laboratory for this kind of work, but it is hoped that for the future this want of support may not be continued. If those interested in marine botany could obtain the necessary funds for the purpose, it would be an excellent thing to have a botanist permanently stationed at Plymouth. The following papers, which have recently been published elsewhere than in the Journal of the Association, contain the results of investi- gations carried on at the Laboratory : — Barthels, P. — "Notiz iiber die Excretion der Holothurien," Zool. Anzeiger, No. 492, 1895. Bidder, George. — "The Collar-cells of Heterocoela," Quart. Jaurn. Micr. Sci. xxxviii. p. 9. Browne, E. T. — " On the Variation of Haliclystus octoradiatus," Quart. Journ. Micr. Sci. xxxviii. p. 1. Garstang, W. — " Budding in Tunicata," Science Progress, iii. Mar., 1895. Garstang, W. — " Outlines of a new Classification of the Tunicata, British Association, Ipswich, 1895. Hickson, S. J. — " The Anatomy of Alcyonium digitatum," Quart. Journ. Micr. Sci. xxxvii. p. 343. MacBride, E. W. — " The Development of Asterina gibbosa" {in 'part). Quart. Journ. Micr. Sci. xxxviii. p. 339. Nutting, C. C. — " Notes on the Peproduction of Plumularian Hydroids," Amer. Naturalist, Nov. 1895, p. 966. directoe's report. 221 Arrangements have been made by which Mr. Garstang will conduct courses of study in Marine Biology, at the Laboratory, during the Easter Vacation. A special room will be fitted up for the accommoda- tion of students joining this class, and it is hoped that a sufficient number will take advantage of the arrangement, to encourage the formation of such classes in the future. Mr. A. H. Church, of Jesus College, Oxford, is also prepared to conduct a similar class in marine botany. Before closing this report, I should like to take the opportunity of drawing attention to some facts regarding the general position of the Association, and its work at the present time. As any further develop- ment of our activity depends so largely upon questions of finance, it will be well if these are considered first, and in doing this it is necessary to distinguish between the maintenance of the Plymouth Laboratory, and the work carried on there, and the expenses of the investigations into the North Sea Fisheries, which have been so success- fully prosecuted on the east coast. The latter have been supported almost entirely by special donations, given from time to time by Mr. J. P. Thomasson, and by the Drapers' and Fishmongers' Companies, and although there is no immediate prospect of funds being forthcoming for their continuation, it is to be hoped that they may not be allowed to lapse for that reason. Leaving these special investigations out of consideration, the annual income of the Association from all sources, amounts to £1,950, and the estimated expenditure for the general conduct of business, and the maintenance of the Plymouth Laboratory on its present footing, is £1,800, which leaves a balance of £150. The want at Plymouth, which must be put before all others, is that of a suitable boat. Experience goes more and more to show that the amount of energy wasted, and the limitation put upon our investiga- tions through this want, is exceedingly great. I do not hesitate to say that the effective work of the Association could be increased by, at least, fifty per cent., if a suitable small steamer were in our possession. Instead of confining our collecting to within five or six miles of Plymouth Sound, the whole western half of the English Channel, including the Channel Islands, would become our field of operations ; whilst the fishery investigations, which we are attempting, could be done more completely, and with far less expenditure of time and serious inconvenience, and others, which are now quite beyond our power, could be undertaken by the present staff. Our income would be sufficient to maintain a boat large enough for our purpose, if only the funds were available to procure her. When this question has once been satisfactorily settled, we may, I 222 director's report. believe, consider that the Association possesses a well-equipped laboratory, capable of turning out a large amount of valuable scientific and economic work, without any considerable increase of the income at present at our command. It must not be forgotten, however, that the above estimate only allows for one naturalist on the staff of the Associa- tion, who can devote any considerable proportion of his time to carrying on research. Further development must then be sought for in the direction of obtaining funds for the appointment of additional natural- ists on the staff, for the resources of the Laboratory will be sufficient to keep several investigators constantly employed, without much additional expense beyond their salaries. Efforts should also be made in all possible directions to induce public bodies to offer scholarships for biological research, which might be held at Plymouth. A number of scholarships are already given to enable the holders to prosecute technical researches in Chemistry and Physics, and if biologists take the matter up, there seems no reason why some of these should not be obtained for fishery investigations. With regard to scholarships for purely scientific work, it is remarkable that whilst the facilities offered to able men, to pursue scientific study up to the examination standard, are by no means limited, opportunities for carry- ing their work to a legitimate conclusion appear to be granted to but few. Year after year numbers of men turn aside directly they reach the point where their real scientific training may be said to commence. These are the men, whose services in the interests of the Association, or, which is saying the same thing, in the interests of Biology in this country, we should endeavour to retain. E. J. Allen. January, 1896. POSTSCEIPT. Since the above report was in the press an opportunity of securing a small steam fishing yacht, upon advantageous terms, has presented itself, and as the vessel appeared to be exactly suited to the work of the Association, the Council decided that it would be advisable to purchase without delay. The yacht, the Busy Bee, of Fowey, is now in our possession, and it is hoped that the confidence of the Council that the supporters of the Association, by subscribing the necessary funds, will recognise the wisdom of the course they have pursued, may not prove to be misplaced. I am glad to announce that Mr. J. P. Thomasson has already been kind enough to make a donation of £100 towards the purchase money. A sum of £G00 is required, and subscriptions may be sent either to the Hon. Treasurer, or to myself. E. J. A. Fehruunj IZlh, 1896. PUBLICATIONS OF THE ASSOCIATION. RECENTLY PUBLISHED. Royal 8w, 109 j>p. AN EXAMINATION OF THE PRESENT STATE OF THE GRIMSBY TRAWL FISHERY, WITH ESPECIAL REFERENCE TO THE DESTRUCTION OF IMMATURE FISH. BY ERNEST W. L. HOLT, Laie Naturalist on the Staff of the Marine Biological Association. PRICE ONE SHILLING. From Messrs. Dulau & Co., 37, Solio Square, London, W. Or from Tlie Director, Tlie Laboratory, Pli/moidh. PUBLICATIONS OF THE ASSOCIATION. Cloth 4to, 150 pp., 18 plates, (12 coloured). A TREATISE ON THE COMMON SOLE. BY J. T. CUNNINGHAM, M.A., Late Fellow of University College, Oxford ; Naturalist to the Association. Price to Members,* 20s. ; to Non-Members, 25s. From tlie Directok, The Laboratory, Plymouth, and through all Booksellers. JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION. Old Series. No. 1, August, 1887 (only a few copies left, reserved for Libraries). No. 2, August, 1888. Price Is. NEW SERIES.— VOLUxME L 1889-90. Eoyal 8vo, xx. and 472 pp., 28 plates. NEW SERIES.— VOLUME XL 1891-92. Royal 8vo, x. and 404 j^P-y I'i plates, 12 looodcnts, and 10 charts. Price, in neat cloth binding, 15s. Qd. ; to Members,* 12s. Separate numbers, in wrappers, 3s. Qd. ; to Members,* 2s. 8d. NEW SERIES.— VOLUME III. Parts 1, 2, 3, 4, and Special Number. May, 1893 ; March, 1894 ; October, 1894 ; February, 1895 ; June, 1895. Separate numbers, in wrappers, 3s. 6d. ; to Members,* 2s. 8d. * Members who desire to obtain tlie publications at a reduced rate must apply to the Director, and not to the Loudon Agents. From the DIRECTOR, The Laboratory, Plymouth. And from the London Agents : Messrs. Dulau & Co., 37, Solio Square, W. OBJECTS OF THE mm ^iologtcal ^ssocicition of i\t tlnifeb fvingbont. THE ASSOCIATION was founded at a Meeting called for the purpose in March, 188-4, and held in the Rooms of the Royal Society of London. The late Professor Huxley, at that time President of the Royal Society, took the chair, and amongst the speakers in support of the project were the Duke of Argyll, Sir Lyon Playfaik, Sir John Lubbock, Sir Josei'H Hooker, the late Dr. Carpenter, Dr. GiJNTHER, the late Lord Dalhousie, the late Professor Moseley, the late Mr. Romanes, and Professor Lankester. The Association owes its existence and its present satisfactory condition to a combina- tion of scientific naturalists, and of gentlemen who, from philanthropic or practical reasons, are specially interested in the great sea fisheries of the United Kingdom, It is universally admitted that our knowledge of the habits and conditions of life of sea fishes is very small, and insufficient to enable either the practical fisherman or the Legislature to take measures calculated to ensure to the country the greatest return from the "harvest of the sea." Naturalists are, on the other hand, anxious to push further our knowledge of marine life and its conditions. Hence, the Association has erected at Plymouth a thoroughly efficient Laboratory, where naturalists may study the history of marine animals and plants in general, and where, in particular, researches on food fishes and molluscs may be carried out with the best appliances. The Laboratory and its fittings were completed in June, 1888, at a cost of some £12,000. Since that time investigations, practical and scientific, have been constantly pursued at Plymouth. Practical investigations upon matters connected with sea-fishing are carried on under the direction of the Council ; in addition, naturalists from England and from abroad have come to the Laboratory, to carry on their own independent researches, and have made valuable additions to zoological and botanical science, at the expense of a small rent, for the use of a working table in the Laboratory, and other appliances. The number of naturalists who can be employed by the Association in special investigations on fishery questions, and definitely retained for the purpose of carrying on those researches throughout the year, must depend on the funds subscribed by private individuals and public bodies for the purpose. The first charges on the revenue of the Association are the working of the sea- water circulation in the tanks, stocking the tanks with fish and feeding the latter, the payment of servants and fishermen, the hire and maintenance of fishing boats, and the salary of the Resident Director and Staff. At the commencement of this number will be found the names of the gentlemen on the staff. In no case does any one salary exceed £250. The Association has received some £25,000, of which £11,000 has been granted by the Treasury. The annual revenue which can be at present counted on is about £1,820, of which £1,000 a year is granted by the Treasury, the remainder being principally made up in Subscriptions. The admirable Marine Hiological Laboratory at Naples, founded and directed by Dr, Dohm, has cost about £20,000, including steam launches, &c., whilst it has an annual budget of £7,000. The Association is at present unable to afford the purchase and maintenance OF a sea-goino Steam Vessel, by means of which fishery investigations can be extended to other parts of the coast than the immediate neighbourhood of Plymouth. Funds are urgently needed in order that this section of the work may be carried out with eflicicncy, The purpose of the Association is to aid at the same time both science and industry. It is national in character and constitution, and its affairs are conducted by a representative Council, by an Honorary Secretary and an Honorary Treasurer, without any charge upon its funds, so that the whole of the subscriptions and donations received are devoted absolutely to the support of the Laboratory and the prosecution of researches by aid of its appliances. The reader is referred to page 4 of the Cover for information as to membership of the Association. CONTENTS OF NEW SERIES, Vol. IV., No. 2. PAGE 1. The Kki'hoductive Maturity or the Commox Eel. By J. T. Cdn- xinhham, ma.. . . . . . . 87 2. Preliminary Note on Trawling Experiments in Certain Bays on THE South Coast of Devon. By F. B. Stead, B.A. . . . 90 3. North Sea Investigations (Continued). By J. T. Cunningham, M.A. 97 4. A Carcincs with a Right-handed Walking-leg on the Left side of the Abdomen. Preliminary Note by Albrecht Bethe . . 144 .'). Notes on Plymouth Hydroids. By C. C. Nutting . . . 14G . 100 0 0 . 500 0 0 TERMS OF MEMBERSHIP. Annual Members . Life Members . , . Founders Governor** Members of the Association have the following rights and privileges ; they elect annually the Officers and Council ; they receive the Journal of the Association free by post ; they are admitted to view the Laboratory at Plymouth, and may introduce friends with them ; they have the first claim to rent a place in the Laboratory for research, with use of tanks, boats, &c., and have access to the books in the Library at Plymouth. All correspoiulinii- sliuulil be addressed to the Director, The Luburatory, Plymouth. New Series.— Vol. IV., No. 3— issued August, 1896.] [Price 3s. 6d. SEP 17 1696 3(ournal ii.fj'ji- OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. Jkr ;>*-;^ -"■ TlIU I'LVMOUTII LAnOllATORY. i PLYMOUTH PRINTED FOR THE MARIXK BIOLOGICAL ASSOCIATION BY W. BUENUON & SON, AND PUBLISHED BY THE ASSOCIATION AT ITS OFFICES ON THE CITADEL HILL. SENT FREE BY POST TO ALL MEM1!E1:.S OF THE MAIIINE BIOLOGICAL ASSOCIATIUN : ANNUAL SUnSCKIPTIUN FOIl MEMBEUSHII', ONE GUINEA. Agents in London :— Messrs. Dulau & Co., 37, Soho Square, W. PATRON. H.R.H. THE PRINCE OF WALKS, K.G , F.K.S. OFFICERS AND COUNCIL. President, Prof. E. Ray Lankester, LL.D., F.R.S. Vice-Pres iden ts. The Duke of Argyll, K.G., K.T., F.R.S. The Duke of Abercorn, K.G., C.B. The Earl of St. Germans. The Earl of Morley. The Earl of DuciE, F.R.S. Lord Revelstoke. The Right Hon. Loi'd Tweedmouth. Lord Walsingham, F.R.S. The Riglit Hon. A. J. Balfour, M.P., F.R.S. Rear- Admiral W The Riglit Hon. Joseph Chamber- lain, MP. The Right Hon. Sir John Lubbock, Bart.,"M.P., F.R.S. Prof. G. J. Allman, F.R.S. Sir Edavard Birkbeck, Bart., M.P. Sir Wm. Flower, K.C.B., F.R.S. A. C. L. Gunther, E.sq., F.R.S. Prof. Alfred Xewton, F.R.S. Rev. Canon Norman, D.C.L., F.R S. Sir Henry Thompson. HARTON, C.B., F.R.S. F. E. Beddard, Esq., F.R.S. Prof. F. Jeffrey Bell, F.Z.S. G. C. Bourne, Esq., F.L.S. Sir John Evans, K.C.B., Treas. R.S G. Herbert Fowler, Esq. S. F. Hahmer, Esq. Prof. "W. A. Herdman, F.R.S. COUNCIL. Elected Members. Prof. S. J. HicKSON, F.R.S. J. J. Lister, Esq. John Murray, Esq., F.R.S. P. L. Sclater, Esq., F.R.S , Sec. Z.S. D. H. Scott, Esq., F.R.S. Prof. Charles Stewart, F.R.S. Prof. W. F. R. Weldon, F.R.S. Governors. Robert Bayly, Esq. J. P. Thomasson, Esq. The Prime Warden of the Fish- mongers' Company. E. L. Beckwith, Es(j. (Fishmongers' Company). Prof. BuRDON Sanderson, F.R.S. (0.\- ford LTniversity). Prof. Michael Foster, F.R.S. (Cam- Inidge University). Sir William Flower, K.C.B,, F.R.S. (British Association). Hon. Treasurer. E. L. Beckwith, Esq., The Knoll, Eastliourne. Hon. Secretary. E. J. Allen, Esq., The Laboratory, Citadel Hill, Plymouth. PERMANENT STAFF. Director — E. J. Allen, Escj., B.Sc. Naturalists. J. T. Cunningham, Esq., M.A. | F. B. Stead, Esq, B.A. Assistant to the Director — T. V. Hodgson, Esq. SEP 17 1896 [ 223 ] Contributions to Marine Bionomics. By Walter Garstang, M.A., Fellow and Lectm-er of Lincoln College, Oxford. I. The Habits and Respiratory Mechanism of Corystes cassivelaunus. Corystes cassivelaunus is a crab of unusually narrow and elongated form, which has received the popular name of " masked crab " from the grotesque resemblance which its sculptured carapace bears to a human face. It is common round all the coasts of the British Isles, and, although normally an inhabitant of the deeper water, is occasionally found at home in sandy pools on the sea shore, and is frequently cast up in hundreds on sandy shores after heavy gales. I. Systematic Position. The systematic position of the Corystoidea has long been a disputed point among carcinologists. Henri M. Edwards (1834) placed the Corystoid crabs near the Dorippidai among the Oxystomata, and re- garded them as connecting links between the Cancroidea {vid the CalappidiTc) on the one hand, and the Anomoura on the other. De Haan (1849) removed the family from the group Oxystomata altogether, and placed it with the Cyclometopa and Catometopa of M. Edwards, in a separate sub-division of the Brachyura, the Brachy- gnatha. Dana (1852) made of the Corystoidea an independent and primary tribe of the Brachyura, distinct from the Cancroidea and Leucosoidea alike. Alphonse Milne-Edwards (1860) reverted to the older view, and placed the Corystida^ near the Calappoid Oxystomata. Heller also (18G3) placed the Corystida^ among the Oxystomata. Finally, Claus (1880) definitely placed the Corystida? in the Cyclo- metopa. In this he has been followed by Miers (188G) and Stebbing (1893). NEW SERIES. — VOL. IV. NO. 3. R 224 CONTRIBUTIONS TO MA.RTNE BIONOMICS. It caunot be said, however, that the real position and affinities of the Corystidoe are yet established. The reason for this uncertainty is probably due to the fact that, as will appear further on, the structure of these animals is remarkably modified in relation to sand-burrowing habits. Some of these adaptive modifications of structure, which re- appear in certain other groups of Crustacea, have undoubtedly impressed the minds of certain writers with ideas of homology and genetic re- lationship between the Corystida3 and groups having no real affinity with that family. The case affords a new illustration of the inadequacy of the purely morphographic method, when unchecked by considerations of functional adaptation, for the solution of problems of relationship and genetic classification. II. Structural Peculiarities. The structure of Corystes cassivclaunus is noteworthy on account of the following features. The second antennte are greatly elongated — as long as, or longer than, the body — and are fringed along their entire length by two rows of hairs, one of which runs along the ventral, while the other runs along the dorsal border of the antenna. The hairs of each row curve inwards towards those of the corresponding row on the second antenna of the opposite side. The second antennse shew a marked tendency to approximate to one another longitudinally; the opposing rows of hairs then interlock, with the resulting formation of a median tube, the lateral walls of which are formed by the jointed flagella of the antennoe, while the dorsal and ventral walls are fenes- trated along their whole extent by the interspaces between the inter- locking hairs. The organ formed by the apposition of the second antennae I shall term the " antennal tube." The long axes of the three stout basal joints of the second antenna are disposed at right angles to one another, and bring about a character- istic double bend in the basal part of the antenna. The double row of hairs found on the flagellum of the antenna is continued backwards along these three basal joints. The hairs on the most distal of the three joints interlock with those of the corresponding joint of the opposite antenna ; the hairs on the anterior face of the deflected middle joints bend inwards towards the median line along the sides of the rostrum, and together with a median triangular tuft of hairs springing from the rostrum itself, form the hairy roof of the proximal part of the antennal tube. The antennal tube opens posteriorly into a rectangular chamber in front of the mouth. This " prostomial chamber," as it may be termed, is roofed by the rostrum in front, the antennal and epistomial sternites CONTRIBUTIONS TO MARINE BIONOMICS. 225 in the middle, and the prelabial plate behind. It is flanked by the two basal joints of the second antennre in front/ and by a forward process of the pterygostomial region of the carapace behind. Its floor is imperfect, and is formed by the anterior part of the third maxillipeds behind, and by a quadrangular sieve in front, furnished by the hairs springing from the two basal joints of the second antennae, the anterior pterygostomial processes, and a special anterior process of the fourth joint of the external maxillipeds. The hairs from all these parts are directed inwards towards the centre of the quadrangular space outlined by the boundaries of the prostomial chamber, and constitute a complete sieve- like floor to the chamber in question. On each side this prostomial chamber leads by a wide aperture into the branchial cavity. The participation of the epistome together with the prelabial space in the formation of a prostomial chamber is one of the features which strongly distinguishes the Corystoid crabs from typical Cyclometopa, Catometopa, and Oxyrhyncha. The arrangements of these parts approxi- mates in some respects to that found in the Oxystomata, where the buccal frame or the peristome is prolonged anteriorly as a definite prostomial chamber to the very tip of the snout. This chamber in the Oxystomata, however, is completely closed in by the third maxillipeds, and is very narrow anteriorly ; in the Corystoidea, on the other hand, it is broad in front, and is imperfectly closed by the third maxillipeds. Ill, Previous Observations on Habits. In Bell's " British Stalk-Eyed Crustacea " (1853) a brief reference is made to the sand-burrowing habits of Corystcs cassivelcamus. Couch had already described the crab as "burrowing in the sand, leaving the extremities of its antennte alone projecting above the surface." The actual process of burrowing appears not to have been observed at the time when Bell wrote, for he quotes Couch's suggestion that the elongated anteuncc possibly " assist in the process of excavation." This theory of the function of the antennae was subsequently rejected by Gosse (1865), as a result of his own observations on the habits of the crab, and again by Hunt (1885), who correctly states that the crab descends into the sand backwards with the greatest agility, " thus leaving the antennae no opportunity of assisting in the operation." The first writers to offer anything approaching a real explanation of the use of the antenucC were the veteran naturalist of Cumbrae, Mr. David Robertson, and Mr. P. H. Gosse. It is difficult to say, and would indeed be ungenerous to enquire, which of these two naturalists has the priority in the matter. Gosse, in 1855, described the outer antennte of Corystes as " together forming a tube " {Manual of Maritic K 2 226 CONTRIBUTIONS TO MARINE BIONOMICS. Zoolofiy, I, p. 158), but he did not apparently publish his observations in full until 1865. In the meantime Mr. David Eobertson communicated to the Philo- sophical Society of Glasgow, on March 13th, 1861, an interesting note on the function of these antennae. He described the burrowing habits of the crab, and shewed that, under these circumstances, the antennal tube preserved " a free passage for the purpose of enabling the animal to carry on the process of its aqueous respiration." Mr. Robertson believed, with Gosse, that the current through the tube was exhalent in character. In another paper he stated that " he had seen the ova cast up through the opening [of the antennal tube]- — the inference being that the animal had placed it by means of its claws within the influence of the current." {Proc. Nat. Hist. Soc, Glasgoiu, vol. i. p. 1.) Gosse (1865) similarly observed that each antenna, from the form and arrangement of its bristles, constituted a "semi-tube, so that when the pair was brought face to face the tube was complete." He also carefully watched a living specimen, as it was sitting upright on the top of the sand, close to the side of a glass aquarium, and observed that the antennal tube formed a channel for a definite current of water. To quote his own words : " I immediately saw that a strong current of water was continuously pouring up from the points of the approximated antennse. Tracing this to its origin, it became evident that it was pro- duced by the rapid vibration of the foot-jaws, drawing in the surrounding water, and pouring it off upwards between the united antenna?, as through a long tube. ..." "I think, then, that we may, with an approach to certainty, conclude that the long antennae are intended to keep a passage open through the sand, from the bottom of the burrow to the superincumbent water, rendered effete by having bathed the gills ; and it is one of those exquisite contrivances and appropriations of structure to habit which are so constantly exciting our admiration . . . [and] are ever rewarding the research of the patient observer." We shall see below that while Gosse's conduit- theory of the function of the antennae is perfectly correct, his inferences as to the function of the antennal conduit are true only to a limited extent. Gosse assumed that the habits of the crab when beneath the sand were similar to its habits when above the sand, and confined his observations to the crab in the latter condition. Experiment shews, however, that there may be a marked difference in the working of certain organs under the different conditions. A third theory as to the function of the antennae in Corystcs cassivelaumis is due to Mr. A. R. Hunt (1885). He says, " I incline to think that the function of the antennte is to maintain a communication between the buried crab and the water above, as without some such con- CONTRIBUTIONS TO MARINE BIONOMICS. 227 nexion there would be a risk of the animals being occasionally buried to a dangerous depth by the accumulation of sand above them. Mr. W. Thompson's statement that the antennae in very small specimens are much longer in proportion to the carapace than in the adult harmonizes well with this hypothesis, as to ensure safety the young would have to burrow to a greater depth compared with the adults than would be pro- portionate to their size." Mr. Hunt was not aware of Gosse's view when he framed the above theory ; but, subsequently, in a footnote to his paper, he referred to Gosse's theory as identical with his own. The two are, however, essentially distinct, if I correctly understand Mr. Hunt's language. According to Gosse's view, the function of the autennaB is to produce a tube subservient to respiration; according to Mr. Hunt's, the function of the elongated antenna3 is essentially sensory, viz., to enable the buried crab to determine the depth to which it burrows. The " danger " to which Mr. Hunt refers is clearly not the danger of suffocation, but the danger of dislodgment from the sand by wave-currents. The arenicolous habits of Corystes are adduced by Mr. Hunt to illustrate one of the various methods adopted by marine animals for resisting wave currents — a view which, in the case of Corystes, I am unable to accept, partly on account of the normally deep water habitat of the crab, and partly on account of evidence given below which tends to shew that the burrowing habits of Corystes are adopted primarily for concealment. IV. New Observations and Experiments. (a) Burrowing Habits. A number of living Corystes cassivelaunus were placed in a series of vessels containing sand of different degrees of coarseness, and it was soon noticeable that these crabs readily burrow in fine sand, but find great difficulty in penetrating very coarse sand or gravel composed of small pebbles. Moreover, a crab that has obstinately declined for several hours to burrow in coarse, gravelly sand, will imme- diately bury itself, if placed in an aquarium of fine sand. In all cases the process of burrowing is effected exclusively by means of the thoracic legs. The crab sits upright on the surface of the sand ; the elongated, talon-like claws of the four hindmost pairs of legs dig deeply into the sand ; the body of the crab is thus forcibly pulled downwards by the grip of the legs, and the displaced sand is forced upwards on the ventral side of the body by the successive diggings and scoopings of the legs ; the slender chelate arms of the first thoracic pair assist in the process of excavation by thrusting outwards the sand which accumulates round the buccal region of the descending crab. This action at the same time, no doubt, loosens the sand in the immediate neighbourhood, and 228 CONTRIBUTIONS TO MARINE BIONOMICS. renders easier and quicker the descent of the crab into its sandy burrow. Briefly stated, in fact, the four hindmost pairs of legs are all engaged in pulling the crab downwards, while the first or chelate pair is engaged in pushing away the more superficial sand in the neigh- bourhood of the crab's maxillipeds. The two actions combine to drive the crab downwards and obliquely backwards. The main object of this latter motion appears to be the prevention of any forcible intrusion of sand into the buccal apparatus. When the carapace of the crab has completely disappeared beneath the surface of the sand, the antenna) are frequently seen to be rubbed obliquely against one another for two or three strokes, whereby the hairs on the antennse are cleansed from adhering particles. This very charac- teristic action of the antenna? was noticed long ago by Couch, and correctly recognised by him as a process of cleansing {vide Bell, p. 161). After this cleansing process, however, the crab proceeds still further in its act of burrowing, and descends deeper and deeper until nothing is visible above the sand but the most distal portion of the antennal tube. Resting passively in its bed of sand, Corystes cassivelaunus spends the daytime thus concealed from all observation. In aquaria an individual will occasionally emerge and remain on the surface of the sand for some time, but this can usually be attributed to the restlessness resulting from strange conditions. I am inclined to think that if the water and sand provided be of a perfectly suitable character, Corystes will remain imbedded throughout the day. (cf. Eobertson, 1. c. supra). I have noticed, however, that individuals which were inactive and concealed beneath the sand during the day, shewed a marked tendency to activity at night. I have observed on several occasions that my aquarium, containing some half-dozen of these crabs, was the scene of distinct excitement and activity late at night; the crabs had emerged from the sand, and were restlessly hobbling about on the surface, as though in search of food. Although I cannot make a final statement upon the point, all my experiences incline me to the view that Corystes cassivelaunus is a nocturnal animal ; it conceals itself in the sand by day as a protection from sight-feeding fishes, but emerges at night for food and recreation. If these habits were ab- solutely constant, we should expect to find the eyes of Corystes undergoing retrogressive changes, as, for example, in the case of Pinnotheres. Such is not the case, however, for the eyes are capable of forming distinct images, as well as, no doubt, of distinguishing light from darkness. (h) Respiratory Currents. We have seen that Gosse observed a current of water setting upwards from the buccal region of the crab CONTRIBUTIONS TO MARINE BIONOMICS. 229 through the antennal tube, and carrying upwards the water which had previously bathed the gills. This current was caused, according to Gosse, by the " vigorous vibration of the foot-jaws." The crab observed by Gosse was sitting on the top of the sand — not beneath it. If some sea-water be coloured by the addition of a little Chinese ink, or finely powdered carmine (the former is the better material), and if a few drops of the coloured water be added to the water in the neighbour- hood of the antennal tube of a buried crab, it will invariably be found that the current which sets through the antennal tube is from above downwards, and not vice versa. The same current may often, and indeed generally, be shewn to exist, even when the crab is not imbedded in the sand. It will then be noticed that the coloured water is sucked between the hairs of the antennal tube, and passes downwards and backwards to the prostomial chamber. Here, in front of the labium, the current divides into two streams, one right and one left, which pass outwards and backwards into the right and left branchial chambers respectively. Finally, the coloured stream emerges from the branchial chamber beneath the edge of the branchiostegite, not at any one point, situated either anteriorly or posteriorly, but along its whole extent, and espe- cially between the bases of the legs. The direction of this current through the branchial chamber is the reverse of that which has hitherto been recognised in all other Decapod Crustacea. In these (e.g., Maia, Cancer, Carcinus, Astacus) the current which bathes the gills is known to enter this chamber beneath the branchiostegite, and to emerge in front by the lateral aperture at the side of the mouth. The normal peribranchial current in Decapod Crustacea is from behind forwards; I shall, therefore, term the current of the buried Corystes a "reversed current," and shall speak of the whole phenomenon as a " reversal " of the normal current. Although Corystes cassivelaunus constantly exhibits this reversed current when imbedded in the sand, yet it is occasionally possible to observe the normal current in the same specimen when the animal is not buried. The coloured water is then rejected when added near the antennal tube ; but if deposited near the bases of the legs, is sucked inwards, and eventually emerges from the branchial cavity into the prostomial chamber, and thence passes either directly to the exterior or forwards by way of the antennal tube. When the normal current is at work it frequently happens that the exopoditic palps of the maxillipeds begin to vibrate. The action of these palps still further intensifies the force of the exhalent currents, and at the same time disperses the streams of water laterally, i.e., the water, instead of passing to the exterior anteriorly in an even stream, is partially diverted to the sides of 230 CONTRIBUTIONS TO ^lARINE BIONOMICd. the crab's body, aud is scattered outwards and laterally by the vigorous lashings of the exopoditic palps. Gosse's observations on the respiratory currents of Corystes cassive- launus are thus seen to be incomplete rather than inaccurate. A current may be directed outwards through the antennal tube, and the effete water from the branchial chamber may be carried away by that channel ; but such a direction of the current in Corystes cassivelaunns is not constant, as Gosse believed, or even usual. Moreover, when the crab is imbedded in sand, the current is always reversed, except for a few seconds now and then, when the crab desires to eject distasteful particles which have entered the prostomial chamber with the respira- tory current. Under such circumstances the reversed inhalent current through the antennal tube is temporarily replaced by a forcible exhalent current. But as soon as the desired ejection has been effected, the reversed current is again set up. This voluntary inhibition of the reversed current can be easily demonstrated by the addition of carmine to the water setting through the antenna). Oddly enough, a weak solution of Chinese ink is less distasteful to Corystes than a mixture of powdered carmine and sea-water. (c) Cause of the Currents. The direction of the respiratory currents is exclusively due to the movements of the scaphognathite, the valve- like and highly muscular appendage of the second maxilla, which is known to produce the regular respiratory currents of other Decapoda. H. Milne-Edwards first demonstrated the important role played by the scaphognathite in Decapod Crustacea; and he maintained that the direction of the respiratory current was absolutely constant, i.e., from behind forwards in all Decapods (1839, p. 136). De Haan (1850, p. 117) has indeed suggested that the current to the branchiae passes from before backwards ; but his remarks on this subject are obviously the result of mere inference, and are not determined by actual experi- ment. He states, for example, that in Portunus the inhalent current sets inwards not only through the aperture between the base of the cheliped and the edge of the branchiostegite, but also through the anterior aperture at the side of the mouth. Experiments on Portumis have shewn me that this is quite devoid of foundation ; the water certainly enters — in part — through the former of these apertures, but the aperture at the side of the mouth is invariably exhalent in function. In the case of Corystes I observed the action of the scaphognathite by removing the three maxillipeds and the edge of the pterygostomial fold of a living specimen. The scaphognathite was completely ex- posed by this preparation, and its movements were readily followed. When the normal current — from behind forwards — was at work, the propulsion of the water could be seen to be effected by a sharp, prompt CONTRIBUTIONS TO MARINE BIONOMICS. 231 blow dealt by the posterior lobe of the scaphognathite, which was succeeded by an undulatory movement from behind forwards of the remaining part of the scaphognathite. As the crab lay on its back the anterior lobe could finally be seen to descend slowly and gently upon the anterior edge of the roof of the chamber, gliding along, and, as it were, stroking its polished surface. When the current is reversed, however, the action of the anterior lobe is quite different; it strikes the water in front with a prompt, decisive blow, and this is succeeded by an undulatory movement of the rest of the scaphognathite from before backwards. The water lying between the valve and the roof of the chamber is thus driven back- wards into the branchial cavity. The action of the scaphognathite is fairly rapid, but after a little observation, checked by the employment of coloured water to test the currents, it becomes quite easy to detect with certainty the direction of the current by inference from the move- ments of the scaphognathite alone. The action of the exopoditic palps of the maxillipeds in causing currents has already been described. Such currents are purely accessory, and Gosse (1865, p. loO) and De Haan (1850, p. 117) have undoubtedly erred in assigning to the maxillipeds an important share in the production of respiratory currents. V. Evolutional Significance. The habits of Corystes cassivdauntis described above seem to me to demonstrate the adaptive nature of the entire organization of this Crustacean, and slight consideration is all that is required to enable a naturalist to recognise the utility of these adaptive features. The burrowing habit is useful as a mode of concealment from enemies. The elongation and smoothness of the carapace, and the elongated claws of the four hindmost pair of thoracic legs, are all features usefully correlated with the specialization of the crab for a sand-burrowing existence. The elongation of the antenme and the arrangement of the hairs upon them, the double bend of their basal joints, the structure of the parts bounding the prostomial chamber, and the arrangement of hairs upon them, are characters which, in conjunction with the reversal of the respiratory current, adapt the respiratory mechanism of the crab in a remarkably complete manner to an arenicolous mode of life. The antennal tube enables the crab to draw its supplies of water directly from the superincumbent reservoir of water, while the arrangement of hairs is such as to constitute a sieve, keeping the sand away from the respiratory organs. 232 CONTRIBUTIONS TO MARINE BIONOMICS. The upright position of the crab is itself a most unusual feature, and is correlated with the formation of an elongated antennal tube ; the posterior position of the legs is functionally correlated with the adoption of the upright attitude. VI. Analogies. A reversal of the respiratory current similar to that which I have just described in Gorystcs also takes place under certain conditions in the allied form Atelecydus heterodon. The habits of this crab are much more complex than those of Corystes, and will form the subject of a later article. An elongation of the antennae, and their conversion into an antennal tube by the interlocking of hairs along their margins, also takes place, as I have recently discovered, in an East Indian Crustacean, Alhunea syrnnista, Fabr., which belongs to the Hippinea among the Macrura Anomala (Anomura). In this type, however, the antennal tube is formed by the first and not by the second pair of antenna?. The antennal tube has obviously been produced independently in Corystes and Alhunea, and affords a remarkable example of homoplastic modification. In all probability the function of the tube is the same in both cases, but no direct observations on this head in the case of Alhunea have yet been made. It seems to me not unlikely that further observation of the habits of Hippa tal'poida of the American coasts will reveal an essentially similar sieve-like function for the curiously bent and setose second antenna? of that animal. BIBLIOGRAPHY. Bell, T. [li'jZ).— British Stalk-Eyed Crustacea, pp. 159-163. Couch, J. (1878).— Cornish Fauna, 2nd Ed., pp. 75, 76. Dana, J. D. (1852). — "Cmstacea." U.S. Exploring Expedition, vol. xiii. Gossc, P. H. (1865).—^ Year at the Shore, pp. 127-131. Haan, W. de (1850). — "Crustacea." Siebold's Fauna Japonica. Hunt, A. R. (1885). — "On the Influence of Wave-Currents on the Fauna inhabiting Shallow Seas." Proc. Linn. Soc., xviii. ZooL, p. 269. Miers, E. J. (1886). — " Braehyura." Challenger Reports, vol. xvii. Milno-Edwards, II. (1834). — Histoire Nat. dcs Crustac^s, 3 vols. ,, (1839.) "Reehcrches sur le Mecanisme de la Respiration ehez les Crustaces." ^7171, Sci. Nat. (2) xi. pp. 129-142. Robertson, David (1861). — "On the Uses of the Antenna? of Corystes cassivelaunus." Proc. Philosoi)h. Soc. Glasgow, v., completed 1864, jip. 55, 56 (with a good figure). ,, (1886-88).— Proc. aiid Trans. Nat. Hist. Soc. Glasgoio, ii. {N.S.), pp. 143, 144. Stabbing, T. R. R. (1893).— "A History of Crustacea." Int. Sd. Series. [ 233 ] Physical and Biological Conditions in the North Sea. By J. T. Cunningham, M.A, SUMMARY. PAGE Results of Professor Otto Pettersson's investigations of the conditions and movements of the various layers of water in the Skagerack and Cattegat, and the influence of these conditions and movements on the migi'ation of fishes. Southern Species entering the Baltic with coast water from the south, Northern Species with coast water from the north . . . . ... 233 Mr. H. N. Dickson's observations in the Fariie-Shetland channel and the northern entrance of the North Sea, and the conclusions he draws from them. Suggested influence upon the migration of fishes of the amount of oxygen in sea- water . 237 Mr. Dickson's paper in the Gcograjjhical Journal for March, 1896, describing the surface salinities and temperatures observed in the International Hydrographic Survey of 1893-1894 . . . . ... 243 Actual peculiarities in the distribution of fishes in the North Sea . . . 246 Southern Species entering the North Sea from the south . ... 247 Probable dependence of the immigration of Southern Species on temperature . . 249 Southern Species entering at the north. All those found in the south, and a great many more occur on the south coast of Norway, though all do not enter the Baltic. Their presence in this neighbourhood due to the warm Atlantic surface drift, or Gulf Stream . . . . ... 252 Distribution of Northern Species. These species principally occur in the deeper water along the east coast of Britain . . . ... 255 The general physical conditions determining the distribution of Northern Species . 257 The migrations of the herring . . . . ... 259 Dilferent sizes of fish of the same species at different parts of its habitat . . 260 In my report, in the preceding number of this Journal, on my observations in the North Sea, I referred briefly to the problem of the relation between the physical and biological conditions. This problem will afford scope for investigation for some time to come,- and the purpose of the present article is to discuss and compare some of the most recent additions to our knowledge of the matter. The paper by Mr. H. N. Dickson, to which I referred in my previous report, was published in the Geographical Journal last March, under the title of " The Movements of the Surface Waters of the North Sea," and in the Scottish Geographical Journal, in 1894, was published a series of papers by Professor Pettersson on " Swedish Hydrographic Eesearch in 2;U PHYSICAL AND BIOLOGICAL CO^'DITIONS IN THE NORTH SEA. the Baltic and the North Seas." Professor Heiucke has discussed the fish fauna of Heligoland, its composition and sources, in an interesting paper iu the series issued under the title of " Wissenschaftliche Meeres- untersuchungeu," by the staff of the Biological Station at Heligoland, in association with the Commission for the Investigation of the German Seas, at Kiel. Professor Heincke's paper is contained in End. I., Hft. 1 of this series (1894), and in the same volume are a number of papers dealing on similar lines with other divisions of the marine fauna of the Heligoland Bight. It will be most convenient and logical to start the present discussion with a consideration of the results of Professor Pettersson's work. He found that the Skagerack and Cattegat were filled with layers of water distinguished from one another by differences of salinity, and that the lower layers entered the channel as under - currents, and could be recognised at the surface somewhere in the North Sea, The different waters he distinguishes are the following : 1. Ocean-water of 35 per thousand salinity or more. 2. Water of from 34 to 35 per thousand salinity. On account of its extension over a great part of the North Sea, this is called North Sea water. 3. Water whose salinity is 32 to 34 per thousand. This forms a broad edging along the coasts of Holland, Germany, Denmark, and Norway, and is named by Pettersson "bank-water." I shall prefer to distinguish it for the present purpose as coast water, 4. Water from 30 to 32 per thousand salinity, or less, belonging to the outflowing stream from the Baltic, The numbers of course signify the parts of salt by weight in a thousand parts of the water. Now, the oceanic water fills the central part of the North Sea as far as the Dogger Bank from bottom to surface. Towards the east it does not reach to the surface, but fills the bottom of the deep channel which extends along the Norwegian coast and into the Skagerack. The North Sea water is found in the North Sea south-east and west of the Dogger Bank, and along the coasts on each side of the North Atlantic Ocean. In the Skagerack it lies over the oceanic water, and is not found at the surface, except in a band along the north coast of Denmark. The North Sea water flows into the Skagerack principally in spring and summer. The coast water flows into the Skagerack most abundantly in autumn and winter, when it reaches a considerable thickness, and predominates at the surface in the central part of the channel. In summer time the quantity of this water present is very much reduced. It is then displaced by Baltic water. / PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 23o The cause of the difference in the amount of the influx cannot be other than the periodic variation in the outflow from the Baltic. When the Baltic outflow decreases, coast water flows into the Skage- rack, where it is found as a thick and relatively warm surface layer in the coldest months of the year. When the outflow of Baltic water increases in spring and summer, the coast water is swept out of the Skagerack again, and at the same time the deeper waters begin to flow in and swell in volume. Professor Pettersson attributes the latter inflow to a reaction upon the deeper strata in the North Sea, due to the energy stored up in the waters of the Baltic, but I must confess that for my comprehension these expressions require further explana- tion. The annual variation in the Skagerack affects the water to a depth of about 50 fathoms. The temperature of the North Sea water varies inversely with that of the season ; it is the coldest water of the Skagerack in summer, and the warmest in winter. The North Sea water varies much in the amount of dissolved oxygen which it contains ; in July, 1890, it was very deficient in oxygen, while in September, 1893, it was supersaturated with that gas, a condition which has only been found to occur in surface waters from high latitudes. The North Sea water begins to flow into the Skagerack in May, and its entrance coincides with the commencement of the mackerel fishery on the Swedish coast. There seems to be a certain connection between the expansion of the volume of 34 per cent, water in the Skagerack, and the appearance of the mackerel and gar-fish. The temperature of the coast water, on the other hand, and still more of the Baltic water, varies with that of the season. The coast water may flow into the Skagerack from two directions, namely, either from the south along the coasts of Denmark and Germany, or from the north along the coast of Norway. This is important, because there are reasons for believing that the coast water has two periods of influx. The first influx occurs in August and September, and is due to the influence of westerly gales. At this time of the year warm water, whose temperature reaches 15° or 16° C, and whose salinity is 32 to 33 per cent, sets in along the north-west coast of Jutland. It fills the central part of the Cattegat from top to bottom as far to the south as a point between Trindelen and Anhalt, and then dips under the Baltic water. In early autumn the herring fishery, with floating nets, in the Cattegat and south Skagerack, coincides with this influx of coast water. In a subsequent part of his paper, Pettersson points out that Mobius and Heincke, in their memoir on the Fishes of the Baltic, 236 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. state that there are 32 species, of which specimens occur in the Western Baltic occasionally, and are not resident there. These fish are immigrants, and 18 of the species are southern forms — that is, forms whose range extends from the Mediterranean to the British Islands, but not to the Arctic Circle, while of the remaining 14 species, 10 are northern forms — that is, species which are abundant within the Arctic Circle, but do not occur in the Mediterranean. The occurrence of the southern forms in the Baltic takes place chiefly in September and October, and, therefore, coincides with the inflow of the southern coast water. The species in question are : — Labrax liqms, the Bass ; Sciaena aquila ; Mullus surmulctus, the Red Mullet ; Brama Kayi, Eay's Bream ; ThynniLS vulgaris, the Common Tunny ; Xipliias gladius, the Sword-fish ; Trigla Jiirundo, the Tub, or Latchet ; Mugil chclo, the Grey Mullet ; Lahrus maculahis, the Spotted Wrasse ; Crenilahrus melops ; Gadus minutus, the Poor Cod ; Merluccius vulgaris, the Hake ; Solea vulgaris, the Common Sole ; Orthagoriscus mola, the Sun-fish ; Engraulis encrasicholus, the Anchovy ; Conger vulgaris, the Conger ; Carcharias glaucus ; Trygon pastinaca. Now, we cannot consider the herring as a southern fish. It is very improbable that herrings enter the North Sea from the English Channel : on the contrary, the evidence points the other way — namely, to the conclusion that the North Sea herrings come from the north ; and the association of herrings with southern coast water is a fact which requires further examination. Pettersson does not discuss the difiiculty. In January, February, and March, the coldest season of the year, there is an influx of water of the same salinity as that previously mentioned — namely 32 to 33 per cent., but of a temperature of only 4° to 5° C, which evidently comes from the north along the Norwegian coast. In 1893 this northern coast water was entering the Skagerack in November, and it was found to contain a very characteristic Plankton, or assemblage of minute swimming forms, entirely different from that of the adjacent water of the Baltic current. The latter consisted chiefly of vegetable organisms, such as Diatoms, Cilio- flagellates, etc., intermixed with Copepods, such as Ccntropagcs hamatus, which occur also in the Cattegat and Baltic up to the Aland Islands, at the entrance of the Gulf of Bothnia. In the northern coast water, on the contrary, vegetable Plankton was scarce, and the animals were of Arctic or North Atlantic origin, which never appear in the Skagerack during summer, e.g. : — Eupliausia incrmis (Krciyer) (Schizopod) ; Hyperoche Kroyeri (Bovallius) {Amphip)od) ; Parathemisio ohlivia (Kroyer) {Amphipod) ; Dii^hyes truncata (M. Sars) {Siphonrown llidges. As occasional immigrants the following species occur : Lahrax lu2ms, the Bass ; Zeus faher, the John Dory : Gadus luscus, the Pout or Bib ; Motclla tricirrata, the Three-Bearded Rockling ; Conger vulgaris, the Conger ; Mustclus vidgaris, the Smooth Hound ; Scyllium canicula, the Small Spotted Dog-fish; Trygon pastinaca, the Sting Ray. To the fundicolous forms may be added Amphioxus lanceolatus, which burrows in the sea-bottom, and is common near the Horn Reef. PHYSICAL AND BIOLOGICAL CONDITIONS IX THE NORTH SEA. 251 How far the movements of these fundicolous species are influenced by the seasons we have very little evidence to show. I think that it will be found that the occasional immigrants are usually taken in the area in summer, i.e., during the period when the water is warm. I obtained a specimen of Mustelus vulgaris off Lowestoft on September 18th, The grey gurnard is not such a distinctly southern form as the latchet, nor is the red, Trigla cuculus. On board the steam-trawler Lucania, to the south of the Horn Eeef in May, no latchets were taken, while northern forms, such as haddock, were abundant, and one halibut was taken. Grey gurnard were plentiful. Latchets were plentiful off Amrum in June, and on the Brown Eidges in September. It will be found that the abundance of these forms in the Heligoland Bight is in proportion to the degree of their restriction to a southern habitat. The turbot, brill, and sole are fairly common along the north- east coast of England, while turbot and brill extend along the east coast of Scotland, accompanied by Trigla cuculus. As for the weevers, I do not think they are rightly said by Heincke to be common in the neighbourhood of Heligoland, as I did not meet with them there, nor at Grimsby, and although Mcintosh records them as not uncommon at St. Andrew's, this may mean merely that a few specimens are seen every year. They were certainly abundant on the Brown Eidges in September. It is well known that in hard winters soles are caught by the trawlers principally in the deeper depressions in the North Sea, especially in the Great Silver Pit south of the Dogger Bank. The latter is an isolated depression, and being cut off from the influence of the water in the deep valley along the north-east coast of Britain, probably contains warmer water than that valley in winter. The physical condition of such depressions in winter does not appear to have been examined, but the fact that soles collect in the Great Silver Pit in winter indicates that the species we are considering are affected by the fall in the temperature of the shallow eastern and southern waters in the coldest months of the year. At present I have no further knowledge of the relative abundance of the southern fun- dicolous species in the southern area and the Heligoland Bight from December to April. The third class of southern species in the same region comprises the littoral species, which live principally among the sea-weeds of the littoral zones, and belong chiefly to the families of wrasses, pipe-fishes, gobies, etc. The commonest of these at Heligoland are : Gdbius minutus, the Sand Goby ; Ncrophis aequoreus, the Snake Pipe-fish ; Ctcnolahrus rupesti'is, the Goldsinny. Less abundant are : Sgngnathus acus, the 252 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. Common Pipe-fish ; Si2^honosfoma typlih, the Broad-nosed Pipe-fish ; and still rarer, Zahrns mixtus, the Striped Wrasse. To these may be added Mugil chflo, the Thick-lipped Grey IMullet, which haunts the shore, but is an active wandering fish, not restricted in its movements like the others. Heincke does not mention Lahrus maculaius, the Spotted Wrasse, which, having a much more extended range than Lahnis mixtus, is more likely to occur at Heligoland than the latter. Possibly this is a mis- take, and maculatus should be substituted for mixtus in the above list. Lahrus maculatus has certainly been taken at Yarmouth and Lowestoft, and occurs all along the east coast of Britain, while mixtus has scarcely ever been taken there. It is not likely that any of these species, except the grey mullet, make long journeys at different seasons ; they are in all probability resident where they are found in the region considered. They are southern species, which are able to bear the winter cold : Heincke states that they are driven in the cold months of the year from the inter-tidal zone into somewhat deeper water. My conclusions concerning southern species entering the North Sea from the south, are as follows : — (1) The area in which the more characteristic southern species, such as mackerel and Trigla hirundo are found, is bounded by a line drawn from the north coast of Norfolk in a north-easterly direction to the 20 fathom line, and following the latter limit to the Horn Reef. (2) Certain southern aperticolous species visit this area only in summer, from May to October, and certain fundicolous species are found there at the same time, but how far the latter are absent in winter is not known. (3) The immigration of these southern forms at this period of the year appears to be determined by the higher temperature due to the season, not by an inflow of water taking place only at that season. The uniform shallowness of the water is, however, an important factor, on the one hand causing a great difference between summer and winter temperatures, and, on the other, protecting the area in summer from the influence of the cold water in the deeper part of the North Sea, to the north and west. Southern Species Entering at the North. We next proceed to study the distribution and migrations of southern species in the northern part of the North Sea. In a previous part of this paper, I have already given a list of 18 species of southern forms, which according to Mobius and Heincke are occasionally taken in the PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 25 o Western Baltic. But it will be more instructive now to take the species of the southern area in the divisions already distinguished, and note which occur in the Western Baltic and which do not, and what others occur in addition. This analysis has been made by Heincke. Of the aperticolous southern species of the southern area of the North Sea, all occur also in the Western Baltic. The mackerel, scad, and gar-fish occur in some numbers, and are classed by Mobius and Heincke as con- stant rarer residents, but are really summer immigrants making their appearance in May, and absent after October or November. The hake is a rare visitor, and has only been occasionally taken on the east coast of Schleswig-Holstein in November and December. The tunny and anchovy are also but occasional immigrants, which have been occasion- ally taken in autumn. Of fundicolous forms, the following, according to Heincke, do not occur in the Western Baltic : Zeus fciber, the Dory ; Callionymus lyra, the Dragonet ; Gadus luscus, the Pout ; Motella tricin-ata, the Three- bearded Kockling : Solea lutea, the Solenette ; Arnoglossus laterna, the Scald-fish ; Galeus vulgaris, the Tope ; Mustclus vulgaris, the Smooth Hound ; Scyllium canicula, the Small Spotted Dog-fish ; Amphioxus lanccolatus, the Lancelet. All these species have, however, been found in more or less abundance on the west and south coasts of Norway, with the exception of two, Solca lutea, and Mustelus vulgaris. The latter has been taken at the Shetlands and Orkneys. Of littoral species only two, Nerophis aequoreus and Lahrus mixtus, are stated by Heincke to occur at Heligoland and not in the Western Baltic, but these again are fairly common on the south and west coasts of Norway, as far to the north as Tromso. On the other hand, the following southern species occur in the Western Baltic, which are not found in the Heligoland Bight or the southern part of the North Sea : — Aperticolous : Sciaena aquila ; Xiphias gladius ; Orthagoriscus viola ; Carcharias glaucus. Fundicolous : Brama Rayi (deep sea) ; Gadus mimdus ; Raja fullonica. Littoral: Gobius niger ; Lahrus maculatus; Crenilahrus mclops; Nerophis ophidion. In addition to these a large number of southern species have been taken more or less frequently on the west coast of Norway. Of pelagic or aperticolous forms, Collett (JSforgcs Fiske, 1875 J gives Lampris luna; Antcnnarius marmoratus ; Argyropclccus Olfersii ; Exococtus volitans ; Alopecias vidpes ; ScojJelus caninianus ; Scomhresox saurus. These southern aperticolous forms found on the coast of Norway, and not in the southern part of the North Sea, are oceanic species which live 254 ruYsicAL and biological conditions in the north sea. in the warmer parts of the Atlantic far from the coasts. The warm surface drift of the Gulf Stream carries them occasionally to the south- west coast of Norway, as also to the west coasts of the British Islands, but they do not penetrate through the English Channel and are, there- fore, not seen in the southern part of the North Sea. They appear to be usually taken on the Norwegian coast in summer. Certain deep-sea species extend from the Mediterranean to the coast of Norway, such as Argentina sphyraena, but most of these have a very wide range, and need not be considered in relation to the present subject. The southern character of the fish found on the south-west coast of Norway is strikingly exhibited by the numerous species of Scomhridae, Fercidac, Sjyaridae, and Lahridac, which are found there. Besides those which have been mentioned as occurring in the Western Baltic, we have of shallow- water forms: — Pagdlus ccntrodontus ; Cantharus lineatus ; Foli/prion ccrniuni ; Acantholdbnis cxoldus ; Acantliolabrus couchii ; Pristiurus melanostomus ; Spinax niger (deep sea) ; Lamna cornubica : NcropMs lumbriciformis. In considering the relation of the occurrence of these southern forms on the south-west coast of Norway to physical conditions, we have to remember that a narrow channel over 200 fathoms in depth runs along that coast at no great distance from the shore, and that even the 100 fathom line does not go further north than the latitude of the north coast of Scotland. The warm Gulf Stream is only a surface layer, and beneath it is colder water. A large number of the southern species have only been occasionally taken on the Norwegian coast, and then chiefly in summer and autumn. They are probably to be regarded as isolated stragglers, which have been partly tempted onwards by the warmth of the water, partly carried by the surface drift. ]\'Iore detailed information concerning the permanence or periodicity of the occurrence of these species on this coast is required. The information available in Smith's recent edition of Fries and Ekstrom's Scandinavian Fishes, I have not yet had time to study thoroughly, as it is only given in separate statements under each species. It would appear, however, that a considerable number of littoral southern species are resident all the year, and it is to be noted that the surface temperature on the coast of Norway, to the north of 60° N. L., does not fall in February below G°, while in the Heligoland Bight it is between 4° and 5° C. in that month. It has been shown by the physical observations previously reviewed that in summer a strong surface outflow from the Baltic northwards along the Norwegian coast takes place, while in winter this is entirely cut off. This water flowing out in summer is at a high temperature, PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 255 being- warmed by the sun. It is therefore as warm as the Gulf Stream surface water from the Atlantic, and it seems to me that this fact is the chief condition determining the annual arrival of mackerel, gar-fish, scad, and anchovy on the south-west coast of Norway, and at the entrance of the Baltic. The southern forms which have been mentioned occur also to some extent along the east coast of Scotland, but more commonly towards the north. It is therefore evident that they come round the northern end of Britain, and travel southwards. Here, again, detailed informa- tion as to the duration of their stay is at present deficient. It is stated that mackerel do not appear at the Orkneys till July, and in the JMoray Pirth are most abundant in August. The gar-fish, skip-jack, scad, and anchovy are all also recorded as occurring in the Moray Firth and on the east coast of Scotland, the three former as far south as St. Andrew's and the Firth of Forth. Others of the southern species which have been mentioned also are taken as isolated individuals, or in small numbers, as far south as St. Andrew's, and only in summer and autumn. Trigla hirundo, for instance, has been once taken at St. Andrew's, while Pagellus centrodontus is said to be not uncommon there. Zeus fahcr, the dory, is rare in that locality. Labrus macidatus occurs, and the only other wrasse is Crenilahrus melops, which is rare. The southern forms are scarcest or altogether absent between the Firth of Forth and the Wash. Distribution of Northern Species. The northern species, that is, species whose range extends beyond the Arctic circle but not into the Mediterranean, which occur in the Western Baltic, are chiefly littoral species, or fundicolous species, inhabiting moderate depths. The herring is the chief exception, being almost the only aperticolous species in the list. The species, as given by Mobius and Heincke, are : Cottus scoiyius, Cyclo2)terus lumpus, Centronotus gunnellus, Zoarccs viviparus, Spinachia viUgaris, Gadus morrhua, Gadus aeglefinuSy Gadus merlangus, Ammodytcs tohiamts, Pleuronectcs platessa, Pleuroncdcs limanda, Flcuronedes microccphalus, Ilippoglossoides limandoides, Clupecc harengus. Less abundant are : Cottis huhalis, Agonus cataphradus^ Liparis vidgaris, Gadus po/lachius, Lota molva, Motella cimhria. The occasional immigrants are : Anarrhichas lupus, Gadus virens, Flcuronedes cgnoglossus, Ilijjpoglossus vulgaris, Liparis Montagui, Stiekaeus iskmdicus (Lumpenus lampdrac- formis), Brosmius brosme, Raia radiata. As we have seen, Pettersson points out that these northern im- migrants are taken in the Baltic early in the year, from February to April, at which season the Baltic outflow has ceased, the force of the NEW SEKIES. — VOL. IV. NO. 3. T 256 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NOKTH SEA. Gulf Stream is diminished, and an influx of cold water 4° to 5" C. takes place into the Baltic, from the north along the Norwegian coast. Five of these occasional immigrants are absent from the Heligoland region, namely, Liparis Montagui, Stichaeus idandicus, Brosmius hrosme, Pleuroncdcs cynoglossiis, and Raia radiata. These are also wanting in the southern shallower part of the North Sea, that is to say, south of the 20 fathom line, except Liparis Montagui, which, according to Day, occurs at the mouth of the Thames and on the south coast of England. These five are the most especially northern of the above list, and are true Arctic species. Liparis Montagui is common along the east coast of Scotland and north-east coast of England. Of Stichaeus islandicus, only one or two specimens have been taken occasionally in the north- western part of the North Sea, once in 40 fathoms off St. Abb's Head, once in February, 1894, ofl' the mouth of the Firth of Forth, and two specimens in July, 1892, 240 miles E. h N. from Spurn Head. Brosmius hrosme, the tusk or torsk, is abundant from Spitzbergen to the Shetlands, but further south becomes scarcer: it has only been occasionally taken off the Yorkshire coast. Pleuronectes cynoglossiis, the witch, is abundant on the Great Fisher Bank, and may be said to be limited in the North Sea by the 30 fathom line. Baia radiata has a similar distribution, not being found south of Yorkshire. Two species found in the Heligoland region have not been taken in the Baltic, namely, Carelophus ascanii, of the blenny family, and the rockling, Motella mustcla. The former is common on the north-western coast of Norway, and occurs rarely on the east coast of Britain as far south as Yorkshire. Motella mustcla extends southwards throughout the southern area of the North Sea, and occurs also on the south coast of England. The other three occasional immigrants into the Western Baltic, namely, the cat-fish, the coal-fish, and the halibut, occur along the east coast of Britain as far to the south as the 30 fathom line, but not south of it. Hippoglossoides limandoides, the long rough dab, is resident in the Baltic, and also in the north part of the North Sea, north of the 30 fathom line, but is absent from the Heligoland region, and from the shallow southern area. The other species mentioned in the above list, although not entirely absent from the southern area and the eastern slope of the North Sea, become much scarcer there, as will be seen from the observations in these areas recorded in the two previous numbers of this Journal. The lemon dab (Pleuronectes microcepkaUis) is found more plentifully along the English coast in the southern area, i.e., along the line of deeper water. Lepidorhomhus megastoma, the megrim, is a northern form, not PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NOKTH SEA. 257 mentioned in the above list because not occurring in the Baltic, It is common in the northern part of the Xorth Sea, in the deeper water, and also at Iceland, and at depths over 30 fathoms on the south-west coast of England. In the northern region the species most abundant in individuals are haddocks, whiting, cod, plaice, dabs, lemon dabs, witches, long rough dabs, megrims, cat-fishes, ling, while on the southern ground the only northern species which are abundant are whiting, plaice, and dabs. In this discussion I have omitted all mention of a number of species, such as Raia clavata, the thornback ray; Baia hatis, the skate; Lophiua 2yiscatorius, the angler ; which are classed by Heincke and Mobius as of indefinite distribution, because they either extend both to the Arctic Ocean and the Mediterranean, or to neither. In the further consideration of the distribution of northern species, three subjects may be taken separately : (1) the general physical con- ditions, (2) the migrations of the herring, (3) the difference in the size of fish of the same species in different parts of its habitat. (1) The general ijhydccd conditions. In general terms, the physical fact which determines the distribution of northern species of fish in the North Sea, is that deep water in open communication with the Arctic Ocean extends along the east coast of Britain towards the coast of Norfolk. If we look at the contour lines of the sea-bottom, we see that the 100 fathom line passes round the north of the Shetlands and bends round to the south, parallel to the Norwegian coast and at no great distance from it. The 50 fathom line passes dowu the east side of the Shetlands, Orkneys, and the east coast of Britain to the latitude of the Farn Islands, and runs north again along the west side of the Great Fisher Bank, to the edge of the Norwegian depression. The 40 fathom line runs further south off the east coast of England, and to the west of the Dogger Bank and Great Fisher Bank. The 30 fathom line runs outside the Dogger Bank, and the whole of the Fisher Bank is more than 30 fathoms in depth. But the 20 fathom line isolates the Dogger Bank, and leaves a valley between it and the slope of the mainland. To the south of this valley the 20 fathom line runs across the North Sea from Flamborough Head to the continental slope. Apart from movement of the water, this depression must contain at the bottom water which is continuous with the cold bottom water of the Arctic Ocean, and which cannot be much affected or raised in tempera- ture by the warm current of the Gulf Stream, both because that is a current of surface water, and because it Hows past the north of Britain to the Norwegian coast. We see thus that the roads of the northern forms and southern forms actually cross one another to the east of the Shetlands and Orkneys, the southern species travelling in the warm T 2 258 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. surface water of the Atlantic to the south-west coast of Norway, the northern species moving at the bottom down the western side of the North Sea. The observations of the Pomerania expedition previously mentioned, show that in summer, in the deep depression, the temperature at the bottom was not higher than 8° C, while at the surface it was 12° to 14° C. At the western side of the southern area the temperature at the bottom was somewhat lower than at the surface, but not on the eastern side. This is attributed to an inflow of cold water from the north. It seems to me that it is with regard to this question of the flow of the cold bottom water at different times of the year, that further infor- mation from the physicists is most required. We know that northern forms, such as haddock and lemon dabs, extend down the east coast of England as far as the Thames, in greater numbers than on the conti- nental side, and we know that there are isolated depressions over 20 fathoms in depth along this side, which are wanting on the continental side. But it would be interesting to know further to what extent the cold water makes its way southward beyond the latitude of the Wash, and what is the cause of its movement ? Reference has already been made to Dickson's account of the entrance of oceanic water down the east coast of Britain from the north, and his opinion that the important property of this water is, that it contains more oxygen than the bottom water of the deeper part of the North Sea, which it replaces. In his interpretation of the observations, Dickson has laid chief stress on the introduction of Atlantic water into the west side of the North Sea at the bottom, and says little of the temperature of the introduced water. Apparently the reason of this is, that the Atlantic water was originally surface water, and was presumably saturated with oxygen. Now, the question of the oxygen in the bottom water introduced, or in that which it displaces, has not been directly investigated. It seems to me that it is very desirable that Mr. Dickson and the other physicists who are studying the phenomena in question, should consider the movements of the water in relation to the contrasted distribution of northern and southern fish, of which I have in this paper attempted to trace the main features. The herring is a northern species, abundant in the Norwegian Sea, and its incursions into the North Sea must, I think, depend, like the presence of the other northern species characteristic of the north-western part of that sea, on the introduction not of Atlantic water, but of cold water from the Norwegian Sea. It seems to me the question is one rather of temperature than of oxygen. In Dickson's conclusions it is noteworthy that the introduced water is a mixture of Atlantic water and water from the Norwegian Sea, and to me the latter constituent and its low temperature appear to be the more PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 259 important factors. In any case it is important that Dickson concludes from his observations that cold bottom water does How from the north down the north-western depression of the North Sea, and this fact corresponds to the prevalence of northern species of fish in that depression and the east coast of Britain. (2) The migrations of the herring. Turning more particularly to this difficult subject, I cannot profess, with the data at present available, to give a complete explanation of these migrations. I propose merely to point out some of the more obvious relations, in the hope that my remarks may be of some use in directing attention to the conditions which have to be investigated. On the east coast of Scotland, it appears at first sight that the summer herring arrive and are present when the water is warmest. In the northern part, for instance in the Moray Firth, the chief fishing is in July and August. Further south it gets later, taking place in August and September, while at Lowestoft it lasts from October to the beginning of December. There is a mackerel fishing at Lowestoft in September and October, so that during October, as I know from personal observation, both mackerel and herrings are being landed in numljers at the same time. But it must be remembered that the mackerel are going away to the south, and herrings are arriving from the north, and also that mackerel usually swim near the surface, and herring near the bottom, or at some distance below the surface. It is probable that at this time wheu the herrings visit the neighbourhood of the Norfolk and Suffolk coasts, the bottom water is colder than it has been during the preceding summer, in consequence of the inflovv of bottom water from the north. This does not explain why the herrings are absent in January, February, and March. But the herrings come to spawn, and there is some evidence that they retire northwards into deep water to feed. All that I would suggest is, that we do not know that the bottom water, where the summer herring spawn, is at its warmest when the spawning takes place of!" Lowestoft, although, according to Dickson, the mixed Atlantic water which makes its way down the east coast of Scotland in summer is warmer than the water it displaces. The warmth of the infiowing water, however, is not very great, its tem- perature is not above 9° C. We have seen that, according to the observations of the Pomerania, the temperature at the bottom in the northern part of the North Sea in summer is frequently below 8° C, and we do not know what the winter temperature is. The hypothesis that the arrival of herrings is connected with a greater supply of oxygen, seems to be inconsistent with the fact that there is at all times of the year such an abundance of bottom fish (haddock, plaice, cod, etc.) in the places where the summer herring fishery is carried on. 2G0 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. We have seen that Pettersson traces a distinct connection between the herring fishery in the Skagerack and Cattegat, and the inflow of coast water. But there appear to be two periods of inflow, one from the south of warm water 15° C. to 16° C. in temperature in August and September, and one from the north of cold water 4° to 5° C. in January, February, and March. Herring fishery is associated with both of these, but principally, it would appear, with the northern water, which con- tained northern forms of plankton. It is well known that there are winter spawning herring in various localities, which must be considered to be races quite independent of the summer spawners. With regard to the relation of the fish to temperature, it is suggestive that on the south-west coast of England, in the neighbourhood of Plymouth, there are no herrings in summer or autumn, but only from about the end of November till the end of February, that is at the time when the water is coldest. Dr. John Murray considers that there is evidence that the herrings of Loch Fyne and the Firth of Clyde reside there permanently, and do not merely make periodical visits, and believes that they feed chiefly in the deep depressions near the bottom. Whether these are the herrings which spawn on the Ballantrae Banks in early spring, we cannot definitely decide at present. But enough has been said to show that the introduction of Atlantic water with a greater supply of oxygen is not a sufficient explanation of the annual migration of summer herrings into the North Sea, and that probably some important and interesting discoveries have yet to be made concerning the relation between the food, breeding, and movements of herrings, and the temperature of the water in which they are found at different seasons. (.3) Different sizes of fish of the same species at different parts of its habitat. Mr. Holt's observations, together with my own, as published in previous numbers of this Journal, have shown the different sizes of plaice in (1) the northern and western part of the North Sea (2), on the south coast of Iceland (3), in the southern shallow part of the North Sea and in the English Channel. In the two latter cases the difference has been precisely exhibited in the lengths of the smallest mature and largest immature specimens. This is probably the best method of testing the matter, for the average size of mature specimens as a standard is liable to the objection that it depends on the extent to which older and larger fish are captured. Mr. Holt's observations in the Journal, and Petersen's * in the Annual Eeport of the Danish Biological Station, refer to small races of plaice in the Baltic. There are three points to be taken into consideration in relation to these * Dr. C. G. Joh, Petersen, the Danish biologist, is not to be confounded with Prof. Pettersson, the Swedish hydrograplier. PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 261 size-varieties or geographical races : (1) that their occurrence in the plaice is only one instance among a number, several other northern species, e.g., the Greenland bullhead, Cottus greenlandicus, and the so-called Norway haddock, Sehastcs norvegicus, being very much larger on more northern coasts than on British coasts or on the south coast of Norway ; (2) the question whether definite structural peculiarities are present, as well as mere size, to distinguish the geographical forms from one another; (3) the question whether the differences are hereditary, each race breeding and transmitting its peculiarities independently, or whether the fish are the offspring of parents from other areas, and owe their peculiarities merely to the conditions under which they have lived and grown. With regard to the first point, we cannot say that the existence of geographical races differing in size is peculiar to northern forms, although it is to these that my attention has been principally directed. It is probable enough that any wide-spread species may be found to show the same state of things. At a certain part of its habitat it appears that a species attains its greatest development, because there the conditions, whatever they may be, are most favourable to it, and at regions lying near the limits of its range it is less favourably circumstanced, and is found in smaller numbers and of smaller size. In Greenland it is stated that the short-spined bullhead attains to six feet in length, although it is the same species as the Cottus scorpius occurring on the east coast of Britain, where it never exceeds a length of fifteen inches. It is very difficult to decide what are the favourable and unfavourable conditions which cause the differences in size in such cases, and the investigation of these conditions would be both im- portant and interesting. With regard to the plaice and other northern species, it might be supposed that a higher temperature was the chief unfavourable condition, and it may probably enough be one of them. We know that the water of the Channel is warmer than the bottom water of the northern part of the North Sea, and this higher tempera- ture extends for great part of the year to the southern narrower area of the North Sea. But on the other hand, the Baltic, which contains plaice of small adult size, is colder, except perhaps in the height of summer, than the North Sea. Here it might be supposed that the lower salinity was an unfavourable condition, but this would not apply to the English Channel. It is possible that the amount of available food, the extent of suitable ground, and the competition of other species, have more influence on the size and general development of a particular species than purely physical conditions such as salinity and temperature. With regard to the second point, it is found in many cases that 262 PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. minute structural peculiarities do co-exist in geograpliical races together with limits of size. Such races, therefore, must be regarded as in- cipient species ; they only differ from species in the minuteness of the structural peculiarities and in the absence of definite limits between one race and another, a continuous transition from one to the other being observed in individuals and in intermediate areas. The study of such geographical varieties is therefore philosophically important, since in these cases we have actually the origin of species before our eyes. Mr. Holt has previously written in this Journal concerning the ciliation of the scales in the males of tlie dwarf variety of plaice in the Baltic, and mentioned that these plaice have been stated to have a smaller number of dorsal and ventral fin-rays. Dr. Heincke had sucraested that the Heligoland plaice were smaller than those of the western side of the North Sea, and probably formed a local variety. Dr. Georg Duncker, at Heincke's request, has investigated,* by the method applied by the latter to races of the herring, the distinguishing characters of local varieties of the plaice. He examined separately specimens from Greifswald, Kiel, the Cattegat, all localities in the Baltic, and from the neighbourhood of Heligoland. It appears from Duncker's results that ciliation restricted to the middle rays of the dorsal and oval fins is more common than a greater extension of the condition. It was more developed in specimens from Kiel and the neighbourhood than in those from the Cattegat, and in specimens from Heligoland was found on the body in two males out of 35, on the fins alone in 18 out of 35. But unfortunately no examination was made of specimens from other parts of the North Sea, and therefore it remains an open question whether the plaice of the Heligoland Bight have the special characters of a local race. Only a small number of specimens altogether were examined by Duncker. It will be remembered that my own examination of the size of mature specimens went to prove that the plaice of the Heligoland region were not smaller at maturity than those of the north-western part of the North Sea. The examination of specimens from the different regions of the North Sea, for the purpose of ascertaining whether constant structural differences can be found distinguishing the local forms, is yet to be carried out. With regard to the third point, whether the peculiarities of local races are hereditary, or are acquired by the individual in consequence of the conditions under which it has lived and grown, to decide upon this, it would be necessary to know in each case how far interchange of * Variation und Verwandtscliaft von Pleuronectes flems L. und PI. lilaUssa L. : Wissensclwftlichc Mcercsunlcrsuchungen. Ncuc FoUje, Erster Band, Heft 2, 1S96. (See this Journal, vol. iv. p. 293.) PHYSICAL AND BIOLOGICAL CONDITIONS IN THE NORTH SEA. 263 individuals takes place between different areas, or whether the individuals of a region are the offspring of parents which lived in the same region. At present it is difficult to give answers to these questions. The English Channel is so extensive that we can confidently conclude that the plaice found there are the offspring of parents that also lived there. But we cannot be certain that the eggs of plaice which spawn between Lowestoft and the Dutch coast are not carried by the currents to some distant region, most probably to the Heligoland Bight, where they would develop into plaice of larger size at maturity. Similarly we cannot be certain that young plaice on the German coast near Heligoland are the offspring of parents which themselves grew up on that coast. To obtain evidence on these matters we must trace with more certainty the movements of the adult fish, and the course which the eggs are compelled to take by the currents. Something has been done in this way by the hydrographers, and by Dr. Fulton in his experiments with floating bottles, and the results indicate that the plaice of the Heligoland Bight are largely derived from spawn shed in the central part of the North Sea. In the Western Baltic the plaice have marked characteristics, distinguishing them even from those of the Cattegat, especially in the small size at which they are mature. Yet according to Petersen, young plaice, in the first summer after their development from the egg, are not found in the Baltic east of Zealand, Moen, and Falster at all, but enter it from the Cattegat when a year old. At the same time, Petersen finds indications that the mature fish in the Baltic emigrate through the Great Belt and spawn in the Cattegat, so that the dwarf plaice of the Baltic, with all their peculiarities, might be the offspring of parents which lived in the Baltic. [ 264 ] Note on a Specimen of Echinorhinus spinosus. By F. B. Stead, B.A. A SPECIMEN of tills somewhat uncommon shark was recently brought to the Laboratory by some fishermen. The following notes on it may be of interest. The fish was taken with a long line baited with mackerel, for conger. It was captured forty miles south of the Mew- stone, at a depth of about forty-five fathoms. The specimen was a female, and measured 6 feet 6 inches from the end of the snout to the tip of the tail. The following are the principal other measurements : snout to anterior edge of first dorsal fin, 46 inches ; snout to anterior edge of pectoral, 20 inches ; the interval between the anterior edge of the pectoral and the pelvic fin was 26 inches. The first dorsal, which was small, was thus situated immediately above the pelvic. The second dorsal, which was smaller than the first, was situated as nearly as possible midway between the first dorsal and the commencement of the caudal fin. The measurements so far tally with Day's description of the species. Attention may, however, be drawn to the measurements which follow in connection with the following statement in Day : " Ventral (fin) . . . commences mid-way between the front gill opening and the end of the caudal fin in elongated forms : or anterior end of the snout and middle of the caudal fin, as observed in the Plymouth and Aberdeen stouter specimens." (Day's British Fishes, vol. ii. p. 323.) In my specimen the distance from the front gill opening to the anterior edge of the ventral was 30 inches : thence to the end of the caudal was 33 inches. On the other hand, the distance of the anterior edge of the ventral to the middle of the caudal was 26 inches, and to the end of the snout was 44 i inches. It will be seen that my specimen corresponds to one of the " elongated forms," and not to the " stouter specimens," said to have been observed in Plymouth. Considering the relatively small number of specimens of this shark which have been captured and measured, the NOTE ON A SPECIMEN OF ECHINOKHINUS SPINOSUS. 265 distinction between the elongated and stouter forms is perhaps hardly- justified, and the measurements above recorded show that Plymouth specimens do not invariably belong to the latter class. In other respects my notes as to the external features of the fish agree with Day's description. The specimen was sent to the IMuseum of Zoology at the University of Cambridge, and I am indebted to Mr. S. F. Harmer for the following further facts in connection with it : The ovaries were undeveloped : there were no large ovarian eggs, and the oviducts were quite small. It should be noticed in this connection that the specimen was probably not full-grown. Day speaks of a female 9 feet long, contain- ing 17 eggs, as having been taken off the Eddy stone, and mentions a male 6 feet 2 inches long " having two large lobes of milt." In various parts of the alimentary canal specimens were found of the parasite Distomum insigne. Several of these were attached to the roof of the pharynx ; two were in the stomach, and appeared to be partially digested ; one was in the small intestine, and several among the turns of the spiral valve. The alimentary canal contained nothing else except some glairy material and a few Isopods belonging to the species Conilera cylindracea (Montagu). One of these was in the stomach, and alive, though very sluggish ; the others were in the large intestine, in the folds of the spiral valve, and appeared to be partially digested. There was nothing else recognisable in the alimentary canal. In some of the specimens referred to by Day, it is stated that dog- fishes were found in their stomachs, and in one specimen there were no fish, but remains of Crustacea, Day further quotes a suggestion made by Mr. Cornish, that there are two permanent varieties of this shark — " one a ground shark : the other a reund or swimming." I have not been able to find the evidence on which this suggestion was based. [ 2GG ] How do Starfishes open Oysters? # By Dr. Paulus Schiemenz. Many inhabitants of the sea know as well as men do that oysters are good to eat, and the destruction which they suffer on this account can scarcely be less than that brought about by human agency. Starfishes especially extirpate them in great numbers, and Mobiusf maintains that they are the most pernicious enemies which the oyster possesses, although, on the other hand, people have not been wanting who held the destruction of oysters by starfishes to be a fable, ^i Collins II calculates the damage done by these voracious robbers on the oyster beds of Connecticut alone for the years 1887, 1888, and 1889, at 463,G00, 613,500, and 412,250 dollars, whilst that done in all other ways, by molluscs, mud, frost, etc., only represented a total of 39,200, 46,750, and 52,450 dollars. In view of this enormous injury caused by starfishes to the oyster beds, it will be worth while to endeavour to obtain a clear idea of how a starfish really succeeds in eating an oyster. It is generally known that bivalve molluscs, and amongst them oysters, can close their shells so tightly against enemies that considerable force is necessary to open them, and the question arises, Is a starfish able to exert that force ? For the purposes of our discussion, we shall divide the starfishes which attack molluscs into two groups. Those of the first group have * Mitthcilungcn des Deutschen See/ischereivereins. Bd. xii. No. 6, 1896. Translated from the German by E. J. Allen. My thanks are due to Professor Dr. Henking, the general secretary of the German Sea Fisheries Association, both for permission to publish the translation of tliis article, and also for the loan of the blocks from which the figures arc printed. E. J. A. t MoBius, K. " Ueber die Thiere der schleswig-holsteinischen Austerbanke, ihre physikalischen und biologischen Lebensverhaltnisse. " Sitz.-Ber. Akad. Berlin. 1893, pp. 67-92. X Fischer, P. "Faune conchyliogiquo marine du departeraent de la Gironde." Act. Soc. Linn. Bordeaux. Tome 25, 1864, pp. 257-344. II Collins, J. W., "Notes on the oyster fishery of Connecticut." Bull. U.S. Fish. Comm., vol ix. pp. 461-497, 1891. HOW DO STARFISHES OPEN OYSTERS? 267 conical shaped arms, increasing in width from the apex to the base, the united bases forming a more or less marked central body {m, Pig, la). Astropecten auirmtiacus, which is common at Naples, may be taken as the representative of this group.* It lives in places where there is more or less deep sand, half buried in which it pursues its prey. The latter consists, for the most part, of bivalves and gasteropods which also bury in the sand, and the starfish forces them, by means of its flexible tube- feet, into its mouth, which is capable of a very remarkable degree of extension. The number and size of these molluscs which an Astropecten Fig. la. Fig. lb. is capable of swallowing passes belief, and the naturalist who keeps one of them in confinement is often astonished to find, sooner or later, quite a collection of shells in the dish, all of which had been concealed in the huge stomach of the starfish. Hamann f counted at one time ten Fccten, six TeUinciy several Conus, and five Dentalium. In the second group of starfishes (Fig. lb) the arms are far from being so conical in shape, but are more or less cylindrical; indeed in the immediate neighbourhood of the body they are somewhat smaller than a little further off, and hence no true body exists. The members of this * AstrojKctcn irregularis may be taken as the representative of this gi'oup in British seas. E. J. A. t Hamann, 0., Bcitrdge zur Histologic dcr Echinodcrmen. Heft 2. "Die Asteriden auatomisch uud liistulogisch untersucht." Jcua. G. Fischer, Svo., 1885. >■ 268 HOW DO STARFISHES OPEN OYSTERS? group, Asterias glacialis, for example, prefer rocky places, or at least hard ground, to a sandy bottom. Asterias devours all animals which it can overpower, having, like Astropeden, a preference for bivalves (especially oysters) and gasteropods which lie free on the surface. On account of the small size of the disc, the mouth of Asterias is capable of very little enlargement, and it would never be able to swallow oysters, which are its favourite food. Moreover, oysters remain firmly fixed to the bottom, and gasteropods also can often hold on so fast that it appears impossible that they should be passed into the stomach through the mouth. Asterias therefore takes up exactly the same position as Mahomed. As the mountain did not come to the prophet, the prophet went to the mountain, and as Asterias cannot bring his prey into his stomach, he sends his stomach into his prey, that is to say, he throws his stomach out like a proboscis, either wrapping it around or forcing it within the shell of his victim, and in this way digests it entirely outside his own body. The throwing out of the stomach of the starfish has been often seen and described : amongst others by Eudes- Deslonchamps,* Mc Andrew, and Barrett (according to Bronn), Forbes,! Rymer Jones, | Bronn, || Eyton,§ Schmidt,ir Hamann,** and Mobius.tt The following example will show how cleverly Asterias can force his stomach through openings which appear little adapted to the purpose. One would think that a sea-urchin, with its thick array of movable spines, would be safe from the attacks of a starfish ; but this is really not the case, as I was myself able to observe, through the kindness of Sgr. Lo Bianco, the conservator at the Naples Zoological Station. A moderately large sea-urchin was attacked by two starfishes, one on either side. One of these had only just commenced the onslaught. It had thrown its stomach through the narrow space between the spines until it reached the skin of the urchin, which, together with the muscles that attach and move the spines, it devoured, so that the spines by degrees fell off. The second starfish had in this way, as one might say, already digested for itself a road through the spines, and with its stomach had reached the mouth of the urchin. Through this, in spite of the urchin's strong teeth, it had inserted its proboscis, and so sucked out its victim like an oyster. » Eudes-Deslonchamp.s, "Notes sur rAsturie commune." Ann. Sci. Nat. Paris, Zool. Tome 6, pp. 219-221, 1826. t FoKBKs, Edw. a Hidory of British Starfishes and other animals of tJie class Echinodermata. London 8vo., 1841. X Rymer Jone.s, Frorieps N. Notiz. Bd. 12. Nr. 288, 1839. II Bronn, H. G., Klasscn und Ordnuncjen des Thierrcichcs. Bd. 2. Actinozoa, 1860. § Eyton, T. C, "A history of the oyster and the oyster fisheries." TJie Edinburgh Review, vol. cxxvii. pp. 43-76, 1868. IT In Brehm's Thierlchen. Grosse Ausgdbc. Auft. 2. Ahth. 4. Bd. 2. Leipzig, 1878. ** Loc. cil. tt Loc. cit. HOW DO STARFISHES OPEN OYSTERS ? 269 Astropeden and Astcrias possess tube-feet of very different structure. Those of Astropeden are conical and quite pointed at the end, and seem extremely well adapted to boring in sand. Suckers at their ends are entirely wanting. Such enlargements would only be a hindrance when boring in sand. On the other hand, Astropeden has no need of suckers, for it does not climb steep walls ; the animals which it preys upon all move so slowly that they could not escape by flight, and there- fore do not require to be held fast ; and thirdly, this starfish does not need to open its victims. With its feet it brings them into the capacious stomach, from which they cannot again escape. It has now only to quietly wait its time, until the animals, killed by suffocation, open their shells and allow the digestive juices to reach them. In the case of Asierias the circumstances are quite different. The animal is a zealous climber, and by preference clings to perpendicular walls. If, like Astrop)ecten, it possessed pointed tube-feet without suckers, it could not do this, but would fall down as Astropecten does when it attempts to climb in confinement. The animals which Asterias eats are some of them capable of relatively rapid locomotion, and therefore require to be held fast. Many of them, too, have the power of tightly closing their shells, and if the Asterias wishes to get at their soft bodies, the shell must first be opened. For clinging, as well as for opening shells, pointed feet would be quite useless. Feet, however, provided with powerful suckers, such as Astericis possesses, are well adapted to these uses. There is, too, a difference between the ways in which the feet of Astropecten and Asterias move. Whilst Asterias, when the suckers have been loosened, curves the feet outwards, and so draws itself back, Astropecten curves them inwards. It is obvious that the latter mode of progression is much better adapted to a life buried in sand, such as Astropecten leads. Different views have been expressed as to the manner in which Asterias and similar forms succeed in opening the shells of molluscs. At the present time it seems to be generally considered that this is accomplished by the secretion of a stupefying fluid, or poison. As we shall see, however, further on, this view is a complete mistake. In what follows we shall consider (1) the possible methods by which the opening of the shell could be accomplished ; (2) which of these is to be considered the most probable ; and, finally (3), we shall endeavour to prove that this method is, in fact, adopted. There appear to be altogether six possible ways : — 1. The starfish might take the molluscs hy surprise. — Bivalves, includ- ing the oyster, are generally very watchful. A small change of light, a shadow, a slight movement of the water, or any trifling disturbance, 270 HOW DO STARFISHES OPEN OYSTERS? immediately causes the closing of the shell. Such sensitiveness seems to preclude completely the idea of their being surprised by the starfish, for before the latter could reach, say, an oyster with its mouth or its everted stomach, it has already freely touched it with the feet on its long arms, and thereby given it sufficient warning. But even if the oyster allowed itself to be taken by surprise, as soon as ever it felt the stomach of the starfish on its soft parts, it would immediately close the shell, and the starfish would generally only be able to escape by tearing off its stomach. If anyone is not prepared to accept this without further proof in the case of the oyster, he has only to consider, say, a Venus, with its strong shell-margins, which, when closed, do not let the very finest crevice be seen, and which would at once crush such a soft body as the stomach of a starfish. According to Forbes, it is the belief of some oyster-fishermen that Astcrias insinuates an arm into the oyster's gape in order to devour it. The oyster then closes, and the star- fish is caught. To free itself again, and not die miserably of hunger, it elects to sacrifice an arm, and this is the reason why so many mutilated starfishes are found. This is a very pretty fable, but it is no more than a fable, for a starfish of moderate size does not insert an arm into a living oyster, for the simple reason that the gape of an oyster, when open, is much too small. 2. The starfish might beset the oyster so long that it would le compelled, hy hunger and want of air, to open. — This supposition is made by the brothers De Montague* and by Smiley. f To say nothing of the possi- bility that, in this case also, the stomach might easily be bitten off by a renewed closing of the shell, the duration of the attack would be a very long one, for it is well known that bivalves, and especially the oyster, can remain closed for a great length of time without air and nourishment. I fancy that during this long siege the starfish would get such a strong appetite itself that it would prefer to look around for more manageable prey. Moreover, the supposition stands in direct contradiction to an observation of my own, according to which from fifteen to twenty minutes is generally sufficient for the opening of a Venus. 3. The starfish might hypnotise the molluscs. — It is known that certain animals, if their bodies are placed in a quite unaccustomed attitude, are subject to a kind of hypnotism. According to Apgar,| if a U7iio, for example, is seized quickly, and the shell firmly pressed, so that the * De MoNTAGUit;, FiiliRES, " Etudes pratique sur les ennemis et les maladies de I'huitre dans le bassin d' Arcachon. " Act. Soc. Linn. Bordeaux, vol. xxxii. (4 ser. Tome 2). 1879. t Smilp:y, Ciias. W., "Notes Upon Fish and the Fisheries." Bull. U.S. Fish. Comm., vol. V. 1885. (From a statement by Capt. S. J. Martin.) X Apgar, Austin C, "The Musk-rat and the Unio." Journal Trenton Nat. Hist. Soc, vol. i. pp. 58, 59 ; also in Zoologist (3), vol. ii. pp. 425-42d. HOW DO STARFISHES OPEN OYSTERS ? 271 protruding foot is squeezed, after half to three-quarters of a minute it becomes paralysed, and can make no more use of the adductor muscles. Apgar believes that the musk-rat {Fiber zihdhicus) takes advantage of this fact in order to get at the soft parts of the mussel. In the case of the oyster, however, anything of this kind does not apply, for it cannot be brought into an unaccustomed attitude, nor has it any foot to protrude and be squeezed. This could, however, happen with other bivalves which are not fixed and which possess a pro- truding foot ; for, whilst being eaten, these are constantly placed by the starfish in a position quite the reverse of the normal one ; namely, with the hinge below, and the gape above. I have tried experiments on the point with Venus verrueosa, but have failed to notice any hypnotic or paralytic effect. I have made a Venus stand for many hours on the hinge, and have afterwards found exactly the same re- sistance to forcible opening as at other times. Since, however, the starfish can effect the opening in from fifteen to twenty minutes, the possibility of hypnotic efiect is precluded. 4. The starfish might make an opening in the shell with the help of a boring apparatus or an aeicl. — No boring apparatus is possessed by Asterias, and the holes which one often finds in oyster shells are due to gasteropods, and not to starfish, although they have sometimes, in error, been ascribed to the latter; e.g., by Ball and Forbes. I have neither been able to find holes in the shell of a Venus which has been devoured, nor an acid reaction in the everted stomach. It is, however, a difficult thing in sea water, which is slightly alkaline, to demonstrate an acid with litmus paper; but when we recollect that the opening is effected in so short a time, the acid would necessarily require to be very strong, and should be capable of demonstration even under such unfavourable conditions. One does often find regular holes on the shell-margin of oysters which have been eaten, but, as we shall see presently, these are produced, not by boring, but by breaking. We come now to the possibility — 5. That the starfish pours a poison over, or, rather, within the shell of its victim, luhercby the muscular force of the latter is enfeebled, and the shell op>ened. — In itself this is not unlikely, and I was at first of opinion that this was, in fact, the method by which the opening was effected, for it is known that many animals maim their victims by poison, derived generally from the salivary glands, before devouring them. However, even this power would not be of much use to the starfish. As already mentioned, a Venus, for instance, squeezes its shell so tightly together that one could almost speak of its being hermetically closed. A poison poured over the shell could not penetrate, but M'ould flow off without effect. In this case also it would be first necessary to NEW SERIES. — VOL. IV. NO. 3. U 272 HOW DO STARFISHES OPEN OYSTERS? bore in the shell an opening through which the poison could be injected. However, as we have seen above (c/. 4), no such boring of the shell does, in fact, take place. The action of poison was assumed by Eudes- Deslonchamps, Forbes, Eymer Jones, Bronn, Eyton, 0. Schmidt (in Brehm), and Smiley (following Captain Martin). Hamann attempts a detailed description of the process; but, for myself, I fail to see upon what logical grounds, from the presence of a slimy fluid and the opening of the bivalve, a proof for the secretion of poison can be derived. It is not even shown whether the slime comes from the starfish or from the bivalve, and it is a fact, which anybody can easily observe, that bivalves and gasteropods commence a copious secretion of slime if their soft parts are handled. I have, however, made experi- ments which demonstrate quite certainly that Asterias does not secrete a poison, or, rather, that a maiming of its victim by this means does not take place. A Venus verrucosa was offered to an Asterias which had fasted for about a week, and was greedily taken. Whilst the starfish was busy opening, or, rather, eating this Venus, a second one was offered it. This also was immediately taken and, for the time, held fast, its hunger, after the long abstinence, not being satisfied in a moment. When the first mollusc was finished, and its empty shell thrown away, the second was carried by the tube-feet to the mouth, and brought into the usual position. In a short time this one also was opened, and opened extremely wide, but the stomach of the starfish was not thrown out, the animal being satisfied with what he had in hand. The Venus was now taken away from the starfish, whereupon it immediately closed, and was laid in a dish with sand. It was not long before it disappeared in the sand in the usual manner, and it afterwards continued quite normal. Specimens of Venus were, in a similar way, taken from other starfishes at different stages of the process of opening, and before digestion could commence. The result was always similar to that in the first case described, and the animals showed no trace of maiming or other disturbance. Experiments were also undertaken with gasteropods, and these were even more instructive, because the creatures are much livelier, and therefore promised to show more readily any disturbance of their organism. It was, at the same time, possible easily to observe directly all the details of what took place. I chose for these experiments my old friend Natica (sp. mille- punctata or ebrea). Whilst experimenting I made a not uninteresting observation, which completes in a satisfactory way some work which I had formerly published. In a paper on the absorption of water by molluscs,* I had tried to establish the physiological significance of the * ScHiEMENZ, P., "Ueber die Wasseraufnahme bei Lamellibranchiaten und Gastro- poden (einschliesslich der Pteropoden)." 2 Theil. Mitth. Zool. Stat. Neapcl. BJ. 7, pp. 423 472. 1887. HOW DO STAKFISHES OPEN OYSTERS? 273 separate parts of the foot of Natica, and in a later paper* I added a further contribution to the subject. I was not quite clear at that time as to the significance of the " shell lobe " (Fig. 2, Sch. Lap.) ; that is to say, the portion of the foot which, in Natica joseigliina almost entirely, in N. millepundata and cbrea only partially, under ordinary circumstances, covers the shell. I have now, however, been able to observe with certainty the use to which this portion of the foot is put. If a few Natica be placed in a dish in which there are some Asterias, rendered hungry by fasting, the molluscs immediately begin to creep about, and the starfishes endeavour to overpower them. The tube-feet of the Asterias are unable to fix themselves to the body of the Natica on account of its slimy surface, and there is only left them the uncovered remnant of the shell. (Fig. 2, Sch.) But here also the attachment is prevented, for the moment the Natica comes into contact with a star- fish it pulls the " shell lobe " of the foot with a jerk over the previously uncovered part of the shell, and thus there is no place left to which the Fig. 2. suckers of the Asterias can fix. I have observed this proceeding a great many times, and it always takes place so promptly that there can be no doubt as to its connection with the means of defence against starfishes. The drawing of the shell lobe over the shell is brought about by the contraction of the transverse, or, rather, annular muscles of the lobe margin, which act like a sphincter. In nature, of course, Natica hardly comes in contact with Asterias, but it does come in contact with Astropecten, and it is clear that the tube-feet of that animal, though they are quite pointed at their ends and have no suckers, will slip from the slimy surface of the Natica just in the same way as the tube-feet of Asterias. If a Natica in the contracted state be given to an Asterias, the latter fixes its tube-feet upon all parts of the shell of the mollusc, carries it to its mouth, and tries to digest it. If the Natica, however, has lived for some time in the dish and become used to the conditions of confinement, it does not through terror remain closed, but, as a rule, comes out of its shell immediately, and endeavours to free itself from the starfish. A • ScHiEMENZ, P., "Wie bohrt Natica die Muschelnau?" Mitth. Zool. Stat. Kcapel. Bd. 10, pp. 153-169. 1891. u 2 274 HOW DO STARFISHES OPEN OYSTERS? hard fight now commences. As soon as the mollusc begins to protrude its foot, the starfish also throws out its stomach and endeavours to commence the work of digestion. By feeling here and there with the margin of the anterior angle of the foot, which serves as a sense-organ, the gasteropod now tries to find a place somewhere between the tube- feet where there may happen to be a larger space, offering a chance of escape. As is natural, the starfish on its part makes convulsive efforts to hold its victim fast, and block every possible way of escape through the forest of tube-feet. If the Natica succeeds in protruding the fore part of its foot sufficiently far for the corners, upon which the apertures for taking in water are situated, to expand themselves, then the battle has been won. When it has made the fore part of the foot swell up a little, it swells the hind part, and from this the shell lobe ; whereupon, by drawing the latter closely and tightly over the shell, it sweeps off all the suckers of the starfish. As soon as this has happened the mollusc is free and creeps away unhindered, in spite of the fact that the starfish, during the whole time, has partially covered it with its everted stomach. Thus no maiming by poison has taken place. As a further confirmation, though this was hardly necessary, I took away from the starfish a couple of Natica which had not been able to free themselves, and had been already somewhat digested during the fight, and bore wounds. These also recovered ; so that there can be no talk of poisoning, Naturally the fight often ends in the destruction of the Natica, especially when the starfish has fixed a great number of feet on the operculum and just behind it ; for it is then impossible for the mollusc to protrude its foot far enough to be able to swell it up. If the gasteropod perceives the uselessness of the attempt to escape, it withdraws into its shell, closing the latter with the operculum ; and then the starfish must first of all open it again. For this purpose there remains one more possibility, namely : 6. That he opens the shell hy force. — This supposition will be doubtless at first opposed by every reader, who knows from his own experience the strength with which bivalves and gasteropods can keep their shells closed. If, however, we consider the position into which the starfish brings his victim when he wants to open it, the supposition becomes more likely. With oysters and fixed bivalves and gasteropods, Asterias cannot do very much: he must take them as they lie, and cannot alter their position. The circumstances are quite different, however, when he is dealing with a free-living mollusc. If we bring a Venus to the end of an arm of a hungry starfish, the first thing it does is to taste it with the long tul)e-feet, serving as sense-organs, wliich are situated there. In a tew moments the many hundred tube-feet, with which it has been HOW DO STARFISHES OPEN OYSTERS? 275 quietly holding on, come to life, and the whole animal pushes itself towards the side at which the mollusc is offered. The arms next to the ones touched are immediately brought near it ; and with these three, or perhaps only with two of them, the Venus is held fast, the arms being gradually pushed over its shell and one sucker after another made fast to it. But the starfish does not stop moving as soon as the arms have reached the far side of the bivalve, and as fast as they are pushed beyond it the tube-feet fix themselves to the ground. Only when the Venus has in this way reached the middle-third of the arm does the starfish cease the forward movement and remain stationary. Meanwhile the bivalve is carried further forward by the tube-feet until it reaches the mouth of the starfish, and is there turned round into such a position that the hinge is below, and the margin of the gape lies exactly opposite the mouth of its enemy. (Fig. 3.) Hamann has already made mention Fig. 3. of this position. Whilst this is going on, the starfish raises its body and the portions of its arms next it into a peculiar mound, as represented in Figs. 3 and 4. The only writer I can find who makes mention of this curious attitude is Mobius.* When the starfish is resting on the bottom of the dish, what happens inside this mound, one is not, of course, able to see. In order to find out, the animal must be induced to ascend one of the vertical glass sides of the dish, which is not at all a difficult thing to do. By holding a mollusc in front of it, a hungry starfish may be enticed over considerable distances and led round the dish. If one does this too much, however, it ceases to respond ; or, when the mussel is again offered after an interval, begins to crawl away. It might at first sight appear as if this rising into a mound served only to hinder the victim from escaping. Apparently this is one of the reasons for it; for in assuming the position the arms are pressed together so tightly that not even a crevice is left through which escape could be effected. But a consideration of Fig. 3, which to some extent represents * Mobius, K., Die Auster und die Austerwirtliscluifl, p. 120. Berlin, 1877. 276 HOW DO STAKFISHES OPEN OYSTERS? a section of Fig. 4, makes it at once evident that if the starfish intends to open the bivalve by force, he can only do so after he has brought himself and his prey into the positions there represented. I will not here go further into physical considerations, but only remark that the mound itself is extraordinarily rigid, and offers very great resistance to any attempt to press it down. The starfish can now divide its tube-feet in such a way that half of them are fixed to one valve of the shell, the other half to the other ; and a pull in opposite directions can be exerted upon the two valves. If the mound formation is adopted in order to open the mussel in the manner indicated, a starfish which is prevented from adopting such a position will not be able to succeed in opening a free bivalve or gasteropod. I therefore made the following experiment: I took a small vertical dish with glass sides, and, by means of a glass ^m-''vAk\^a Fig. plate, separated off a compartment in which there was just depth enough for a starfish to creep, but in which he could not form a mound. When I had put a starfish, which had been prepared by previous fasting, into this small compartment, I offered him a closed Natica, which he immediately took. Now whereas, under ordinary conditions, provided a long fight did not take place, a starfish would open a Natica in a relatively short space of time,* this starfish wandered round the dish for nearly a whole day, from morning till evening, with his victim — which all the time remained closed — without managing to digest it. It was only towards evening, after many vain attempts, that by all sorts of contortions of his arms he succeeded in forming a mound in a (|uite unnatural Avay, namely, between the glass sides and in a position * There is no need to explain further that gasteropods are opened in exactly the same way as bivalves ; some of the tube-feet of the starfish being fixed to the shell itself, whilst others are fixed to the operculum. The gasteropods are brought into an exactly similar position. HOW DO STARFISHES OPEN OYSTERS ? 277 parallel to them. Then he set about opening and digesting the Natica. This result clearly confirms the correctness of the above supposition. In the case of oysters the circumstances are different, in so far that, under natural conditions, these animals are fixed to the ground, and are also considerably larger than the other bivalves. If a starfish, wishing to open an oyster, can find suitable points for fixing his arms on the objects which lie around, it will give him no great trouble to pull his victim apart. Should he not, however, find these, he must form a mound exactly similar to that in Fig. 3. Physical considerations, how- ever, show that under these circumstances, since he must support the portion of the arms marked a — h in Fig. 3 on the oyster itself, there will only be a prospect of success when this point of support of the arms lies quite far towards the hinge, or even beyond it, so that the Fig. 5. arms can mutually assist each other. There must therefore always be a definite size-relation between the oyster and the starfish ; and from this it follows further that large oysters are relatively safe from the attacks of starfishes, whilst small and medium sized ones are specially liable to destruction. Perhaps some day an oyster fisherman will collect evidence on this point. In relation to the matter I must, however, remark that an oyster can only be regarded as successfully attacked when it has been actually opened ; and a simple attempt on the part of the starfish of itself proves nothing. In the figures which Collins gives on Plate 165 (Figs. 1 and 2), the size-relation under discussion is clearly seen; and I believe I am not mistaken when I imagine that I can see in the positions of the starfishes in these figures the mound formation which I have described. ; In Fig. 5, which I give here from an observation of my own, the starfish has already completed the work of opening ; and has, indeed, already digested the greater part of its victim. There is nothing more 278 HOW DO STARFISHES OPEN OYSTERS? to be seen of a mound formation, since it is no longer necessary, on account of the destruction of the adductor muscle. I give the figure, nevertheless, because in this case the starfish has made use of the bottom of the dish as the point of support, or attachment, for a portion of the arms. The position of these arms is exactly the same as in Fig. 3 : the feet on the parts near their centres (above h) being fixed to the oyster's shell, those on the distal parts (a) to the bottom of the dish. In the figure is seen also very clearly the manner in which the stomach (m) is thrown out, and what a significant position it occupies. That I have not succeeded in this case, as I was able to do with Vcjius, in directly observing the whole process of opening, was due to the fact that the oysters were opened by the starfishes at night. Whether this was accidental or not I cannot say. Venus and Natica were taken and opened at whatever time of the day they were offered. ^fN*. Fig. 6. An examination of shells which have been eaten out, also shows that the starfish pulls powerfully upon the shell of an oyster which he is about to devour. The margin of oyster shells, at least at Naples, is always more or less laminated. Now, in oysters which have been eaten out, the laminated margin of the upper shell is always broken away for a greater or less distance, until the deeper and stronger layers are reached. Fig. 6 shows such a shell; on which, however, the injured place was specially conspicuous. I need hardly mention that I care- fully examined the margins of the oysters before giving them to the starfishes. As no other animals were in the dish excepting oysters and starfishes, the effect upon the shells of the oysters which were eaten could only be due to the starfishes. Moreover, I have seen such broken portions of shell directly attached to the suckers on the feet of a star- fish which was resting upon an oyster. Such broken places I have only found on the flat shell, which is clearly due to the curved shell being less laminated, and, therefore, less easily injured. HOW DO STARFISHES OPEN OYSTERS? 279 The points, recognisable by the injury just described, at which Asterias opens the oysters, show a certain degree of definiteness in position. They do not, however, as I at first suspected, exhibit a perfectly regular relation to a line drawn through the hinge and the muscle scar. In general, indeed, they lie on this line, and this can be readily understood, since the two shells of the oyster represent, to some extent, two levers, with a fulcrum at the hinge. The further the point of seizure lies from the hinge, that is to say, the longer the arm of the lever, the more effective will be the force applied. Precisely on the longest shells, nevertheless (Fig. 7, Nos. 3, 6, and 10), we find the point of seizure lies, not on the line mentioned, but displaced quite Fig. 7. to one- side. I can only explain this variation on the supposition that these oysters were of too great length in the direction of the line through the hinge and muscle for the arms of the starfish, and the latter had to find positions in which their arms could reach further over the shell. The point of seizure in these shells always lies on the side which exhibits the less vigorous growth. This seems to be a general rule in all cases in which the oysters show unequal growth (compare also Nos. 7 and 11 in Fig. 7), and possibly depends on the fact that on the side where there is less growth the shells are naturally less laminated, and the starfish, therefore, has more chance of coming to firm portions of the shell, upon which it can effectually fix its tube- feet. In oysters from other localities, whose shells arc firm at the 280 HOW DO STARFISHES OPEN OYSTERS? margin, and less laminated than those at Naples, such places as those just described, made by breaking away portions of the shell, will naturally not be found. On them, therefore, it will not be possible to ascertain the spot where the starfish has taken hold. Thus, I have come to the conclusion that the starfish opens the shell of his victim by force, and I must now bring forward proof that the animal does actually possess sufficient strength for the purpose. To do this, the strength of a moderate-sized starfish must first of all be measured. As may be seen from Figs. 3, 4, and 5, the starfish does not use all its tube-feet in opening a bivalve, but, at most, only those on the central halves of the arms. In measuring the strength exerted. Fig. 8 the other tube-feet, therefore, must be left out. I succeeded in doing this in the following way : — A hole was cut in a board of a size corresponding approximately to that of the portion of the starfish which comes into play in opening molluscs. One side of the board was covered with a glass plate (in which was a corresponding hole), giving the starfish the opportunity of attaching itself firmly with the remainder of its tube-feet. An Asterias was now enticed with a bivalve on to the board, and the mollusc offered to him through the hole in the board. The bivalve itself was bound round with a string, which was passed, by means of a pulley, over the edge of the dish, and carried at its end a board upon which weights could be placed. After the starfish had taken the mollusc, weights were put on until it let it go. This happened with a weight of 1350 grams. This figure does not, however, represent HOW DO STAEFISHES OPEN OYSTERS ? 281 exactly the strength of the starfish, but is considerably less. Indeed, I have observed that if one endeavours to pull away again a mollusc which has been offered it, a starfish will resist for some time, but if the pull lasts too long, or is too strong, it quite suddenly draws in all its tube-feet, lets the mollusc go, and cannot be persuaded to take it a second time. However, if we accept 1350 grams provisionally as representing the strength of the starfish, we shall, in what follows, be able to show that so much power is far from being necessary for the forcible opening of a moderate-sized Venus. This sounds unlikely, especially since one knows that, according to Lawrence-Hamilton,* a Venus can, with its adductor muscles, with- stand a strain equal to 2071 times its own weight (without the shell). I have myself seen that, with a momentary weight of 4000 grams, a a, r : ■/ Fig. 9. Venus does not think of opening. But the circumstances are com- pletely changed when, instead of a momentary strain, a continuous one is applied. Everyone knows from his own experience that to lift a weight, and to support it for a long time, are two quite different things. In order to investigate the resistance offered by Vemts to a strain, I had a jar of sea water sent from Naples, followed, some days after- wards, by a number of Venus verrucosa (as samples without value) wrapped in moist linen. The latter arrived in Hanover in three days, and were in full vigour, protruding their siphons normally as soon as they were placed in their native element. In order to measure their strength, I constructed, with the modest appliances at my disposal, the apparatus figured above. (Fig. 9.) The * Lawrence-Hamiltux, J., "The Limpet's Strength." Nature, vol. xlv. p. 1S7. 1S92. 282 HOW DO STARFISHES OPEN OYSTERS? apparatus had to be so devised that the bivalve, whilst remaining in water, could be placed in such a position that a measurement of the extent of opening of the shell could easily be made. A glass dish containing sea water (g) was placed on a small table. In this one stood a smaller but higher dish, also containing sea water, which could be renewed from time to time from the larger one. A Venus was now surprised, the handle of a scalpel being placed between the two shells before it had time to close them. The bivalve of course, as soon as the scalpel was put in, closed immediately, and held it fast, and so could easily be taken out. Two tlesh-hooks were then taken : a short one made entirely of metal, with two teeth at each end (/), and a second one with a scalpel handle (/'). The two teeth at one end of the short hook were placed in the shell-opening. The teeth of the second hook were also placed in the opening in such a way that they came between the teeth of the short hook. A double string was then slung from the two hinder teeth of the short hook, and a similar string was made fast to the larger one at the beginning of the flat handle. The handle of this hook was placed between the two strings on its own side, so that it was kept in position by them. By this arrangement, with the aid of the friction of the double strings on the edges of the dish (at a and a), the bivalve was held quite motionless, with the opening upwards. The molluscs were not disturbed by this experi- mental strain ; but, as soon as the shell was far enough open, protruded their siphons and commenced breathing, so that one may say that they were simply normal. Attached to the double strings (at d and d') was a single common string, from the middle of which a scale-pan (w) hung. The weights on this scale-pan were, of course, not all effective, on account of the considerable friction at the points a, h, c, and a', b', c'. In order to determine the true effective weight, I afterwards replaced the bivalve by a spring balance, which was pulled out by the weights. Such spring balances never weigh quite correctly ; but in this case one or two grams does not matter, and I give, therefore, in the following tables, only round numbers (friction being allowed for) : — 1. Venus 4 cm. long, 3-4 cm. broad. 7.55 a.m., loaded with 900 grams. 8.10 „ commenced to open. 8.15 „ open 2 mm. 8.30 „ open 3-5 mm. 1.0 p.m., open 3-5 mm. G.IO „ open 4 mm. : then set free. HOW DO STARFISHES OPEN OYSTERS ? 283 2. Venus 3-9 cm. long, 3-2 cm. broad. 6.15 p.m., loaded with 900 grams. 6.20 „ open nearly 2 mm. 6.30 „ open 4 mm. 7.5 „ open 6 mm. 8.7 „ open 5-5 mm. (because a lamp was brought near). 9.0 „ open 6 mm. 9.30 „ open 6 mm. 6.15 a.m. the next morning, open 6 mm. : then set free. 3. Venus 4 cm. long, 3-3 cm. broad. 7.0 a.m., loaded with 900 grams. 7.5 )) open 2 mm. 7.10 J) open 3-5 mm. 7.15 » open 4 mm. 7.30 » open 5 mm. Load increased to 1250 grams. 7.38 a.m., load increased to 1700 grams. 7.46 ,, load increased to 2000 grams. 8.10 „ open 7 mm. 8.15 „ adductor muscles ruptured. 4. Venus 3-6 cm. Ion", 3 cm. broad. 8.19 a.m., loaded with 900 grams. 8.40 „ open 3 mm. : then set free. 5. Venus 34 cm. long, 2-8 cm. broad. 8.40 a.m., loaded with 900 grams. 8,56 „ open 1-5 mm. 9.2 „ open 2 mm. 12.27 p.m., open 2-5 mm. Load increased to 1000 grams. 2.0 p.m., open 2-5 mm. 6.45 „ open 2-5 mm. Load increased to 1400 grams. 7.15 p.m., open 3 mm. 7.45 „ open over 3 mm. 9.50 „ open 4 mm. : then set free. 284 HOW DO STARFISHES OPEN OYSTERS ? 6. Venus 3-7 cm. long, 3 cm, broad. 9.50 p.m., loaded with 1000 grams. 10.15 „ open 2 mm. 10.30 „ open 4 mm. 11.30 ,, open 4 mm. 7.0 a.m. next morning, found with adductor muscles ruptured, 7. Venus 3-3 cm. long, 2-8 cm, broad. 8.0 a.m., loaded with 900 grams. 8.24 „ open 1-5 mm. 9.45 „ open 2-5 mm. 10.20 „ open 3-5 mm. : then set free. Several of the molluscs closed somewhat when approached or disturbed; but as long as the strain was continued they could never shut up completely, even when their soft parts were mechanically irritated. With the exception of the two which were torn apart, they all closed again completely and tightly immediately they were freed from the strain, and when left to themselves behaved quite normally. It will be seen from the tables that different individuals resist the strain to a very different extent. Generally a weight of 900 grams* is quite sufficient to open a Venus in from five to twenty-five minutes, or, on an average, fifteen minutes. Further, it follows from experiments 3 and 6 that a strain of 2000, or even 1000 grams, exerted on both shells at once, is sufficient, if continued for some time, to rupture the adductors; whilst, according to the results both of Lawrence-Hamilton's experiments and of my own, not even a weight of 4000 grams is enough to bring about a sudden rupture. The difference in effect between a momentary and a continuous strain is thus most clearly shown. We saw above that a starfish of moderate size can develop a force of at least 1350 grams with the tube-feet which come into play ; so that it possesses more than sufficient strength to forcibly open a Venus, since for this purpose at most 900 grams is necessary. The conclusions we have come to are therefore completely confirmed by experiment. What applies to a Venus applies also to an oyster ; which, according to Lawrence-Hamilton, can only resist 1919*5 times its own weight (without the shell), and hence is somewhat weaker than Venus. It hardly requires to be stated that every starfish cannot open every oyster or bivalve, and that the size and strength of the two must be in suitable proportion. * I have not ascertained how small a load is necessary to cause a slight opening of the shell. It only concerned me to learn whether a weight of 1350 grams is large enough. HOW DO STARFISHES OPEN OYSTERS? 285 In order to afford an idea of the rapidity with which a starfish completely devours an oyster or bivalve, I may mention that a starfish of moderate size had completely digested a Venus 3 7 cm. long in 81- hours, and an oyster 2 J, cm. in diameter, which was given it open, in 4 hours. In conclusion, I would point out that the oyster or mussel culturist should take the greatest pains to destroy starfishes wherever and whenever he can get hold of them. It is not sufficient, however, to tear them up, since they possess an extraordinary power of regenera- tion, and are able to replace lost parts in a relatively short time. The central body especially plays an important part in this process, and it is probably for this reason that (according to Forbes) regulations exist in certain parts of England which oblige the fishermen to tear or crush the central body of starfishes which they capture, before throwing them overboard. In many districts it would no doubt be worth while to bring the starfishes ashore, and use them as manure. The practical Americans have constructed a special dredge — the " star dredge " — an iron instrument carrying a number of tangles, with which they syste- matically capture starfishes on the oyster beds. [ 286 ] Algological Notes. By George Brebner. The following is a list of the most important finds since the report in the last number of this Journal. NEW TO BRITAIN. MYXOPHYCE.E. Oscillatoria rosea, Crn. (Queen's Ground). *Symploca aUantica, Gom. f. jJurjmrea, Batt. in lit. (Yealm). *HyeUa cccspitosa, Born, et Flah. var. nitida, Batt. PHzEOPHYCE^.. Rcdfsia disciformis, Cm. (Yealm). FLORIDEiE. *Acrochcdium endopliytimm, Batt. in lit. (Off west-end of Breakwater). *Cruoria rosea, Crn. f. purpurea, Batt. (Yealm). Gruoriopsis crvciata, Duf. (Queen's Ground). „ Haucldi, Batt. (Off west-end of Breakwater). Peyssonelia rupestris, Crn. (Queen's Ground). NEW TO PLYMOUTH DISTRICT. CHLOEOPHYCE^. Cladophora hirta, Klitz. (Drake's Island). PH^OPHYCEiE. Lithoderma fatiscens, Aresch. (plurilocular sporangia, not previously found in Britain.) (Bovisand Bay). „ simulcms, (Kuck.) Batt. ALGOLOGICAL NOTES. 287 FLOPJDEiE. Acrochcetium microscopicum, Niig. (Andern Poiut). Peyssonelia Harveyana, Cm. (Queen's Ground). Rhododermis elegans, Cm. (Queen's Ground, etc.). Litliothamnion Stromfcltii, Foslie. (Queen's Ground). Peyssonelia Bosenvingii, Schm. (Wembury Bay). Those marked thus * are species, or forms, new to science. The new species of Acrochcetium is interesting on account of the main part of the thallus being endophytic, the sporangia being raised above the surface of its host Dasya coccinca, on short one — to a few- celled stalks. This plant therefore occupies a place in the genus Acrochcetium similar to that of Rhodochorton mcmbranaccum in its genus. The latter plant, however, is not endophytic, but grows within the polypary of various hydrozoa. A. endophyticum was described in its barren condition at the Liunean Society's meeting of 19th December, 1895. The sporangia were not found till January, 1896. Cruoria rosea, Cm. f. jyurpurea, Batt. in lit., is probably only a more advanced stage in the life- history of Cruoria rosea, Crn., than had hitherto been recognised. It is so like the figure of Crouan's Cruoria imrpurca that it would have been identified as such by Mr. Batters and myself but for the fact that our solitary specimen showed several inter- mediate stages. Cruoriopsis Hauclcii, Batt. in lit., is an interesting member of the Squamariaceffi, dredged off the west end of the Breakwater. The tetraspores showed almost every transition from zonate to cruciate. It most nearly resembles Cruoriella armorica of Hauck (non Crouau). As one of the two species bearing the name of Cruoriella armorica will have to be re-named, Mr. Batters proposes to call our plant as above. The other finds do not call for special mention here. Certain cultivation experiments were carried on which gave interest- ing results, chieily with regard to the germination of spores. The most important of these was obtained in the case of Ahnfeltia ^j/tca/a, Fr. The nature of the fructification of this alga had not been satisfactorily cleared up, the late Prof. Fr. Schmitz maintaining that what had hither- to been regarded as the fructifying nemathecium was a parasite. His view, however, while widely accepted by algologists, was opposed by Eeinke and others. Specimens of this alga, vichly fruited , were placed alone in a glass jar, in sterilised sea- water, on the 1st February, 1890, and after two mouths (oOth March) a very great number of germinated spores, in the shape of small discs, were found on the sides and bottom NEW SERIES. — VOL. IV. NO. 3. X 288 ALGOLOGICAL NOTES. of the glass jar. The structure and appearance of these discs was such as to practically leave no doubt that they were early stages in the growth of Ahnfeltia iMcata, and not of a parasite. As a result of this experiment, I am strongly of opinion that Prof. Fr. Schmitz's genus Sterrocolax will have to be sunk, and in this view I am supported by Mr. Batters. Unfortunately, owing to the difficulties of cultivation, I did not succeed in getting the culture beyond the disc stage. As the Koyal Society has generously renewed the grant by the aid of which these investigations are being carried on, I hope to repeat the culture, with more success, when the season comes round again. As part of my investigation, I am studying the attaching discs of the red sea-weeds, or Florideas, in order to ascertain to what extent the conditions found in Dumontia Jiliformis, Grev., prevail in other species. So far I have found no other alga which shows a mode of development, from an attaching disc, similar to that described for D. filiforinis. Cf. " On the Development of the Filamentous Thallus of Dumontia Filifor- inis" Journal of the Linnean Society — Botany, vol. xxx. A large number of red sea-weeds {e.g. Gigartina, Polyides, Stennogramme, Phyllophora, Ahnfeltia) are connected with their attaching discs by a simple parenchyma-like tissue ; one or two forms present different and interesting features in the development of the vertical frond from the attaching base, and when their structure is more fully worked out will, in due course, be described and published, but these conditions in no wise resemble what was found to be the case in D. filiformis. The germination of the spores of Glwosiphonia capillaris has yielded interesting results with regard to the mode of formation of the attach- ing disc. On germinating, the spore sends out a few-celled filament, which by the radiate branching of one or two of the cells forms a well- marked disc. My friend Mr. Edw. Batters has continued to give me his invaluable aid in the identification of species, &c. Two or three of the above finds are entirely due to him {e.g. Peyssonelia rupestris, Cm., Lithothavinion Stromfeliii, Foslie), he having recognised them in material forwarded from the Laboratory. The new species and forms will be described by Mr, Batters in the forthcoming number of the Journal of Botany {i.e. in September). [ 289 ] SUPPLEMENT TO Report on the Sponge Fishery of Florida and the Artificial Culture of Sponges.* By E. J. Allen, B.Sc. Hon. Secretary of the Marine Biological Association, and Director of Plj-mouth Laboratory. Since the Eeport on the subject of the Artificial Culture of Sponges was published, some further information of importance relating to the subject has been courteously supplied by the Acting Commissioner of the United States Commission of Fish and Fisheries. This information is in the form of a letter to the United States Commission from Mr. Ealph M. Monroe, of Cocoanut Grove, Biscayne Bay, Florida, to whom the Acting Commissioner refers as "an intelligent and energetic man, whose statements, we think, can be given entire credence," wherein this gentleman gives a detailed account of some experiments conducted by himself at Biscayne Bay, during the years 1889, 1890 and 1891. The letter, which is published by permission of the Acting Com- missioner, is as follows : — "Cocoanut Grove, Dade Co., Flokida, March 20th, 1895. " U. S. Fish Commission, Washington, D. C. "Dear Sirs, — Agreeably to request made by you for a brief report on my experiments in sponge culture, I am pleased to submit the following : Having had my attention called to the possibilities of sponge culture by Mr, J. Fogarty, of Key West, a gentleman of much experience as a buyer and packer of the article, and who hud a few years previously successfully grown a few samples from cuttings, I began work in the same line in November, 1889, at Biscayne Bay, a place admirably * This Journal. Vol. iv. p. 188. X 2 290 REPORT ON THE SPONGE FISHERY OF FLORIDA adapted to such experiuientiuij, far more so than any other place on the coast, having a greater range of bottom from the oozy marls of the inner lagoons to the hard outer coral reef, waters of all degrees of density, from the Gulf Stream to fresh, and currents to suit. Being already well provided with a vessel, boats, sponge hooks, and water glasses, the question of suitable material for attaching to and sinking the cuttings to the bottom gave some trouble, although apparently a simple problem. Saplings of white wood which were plentiful, fairly proof against worms, and heavy enough to retain their place in strong tide- ways, were finally chosen. They were about 12 feet in length, with a cross piece at one end to prevent rolling over. The cuttings were fastened to them by various contrivances, wedged into holes with pegs, wires around the pole, etc., but the quickest, if possibly not the best, as it afterwards turned out, was short pieces of brass wire doubled and driven into the pole with a peculiar grooved punch, which could be done rapidly. At other stages of the experiment I used bamboo stakes, long double lines of twisted wire connected by cross pieces of white wood, with the cuttings inserted between the strands, also flat pieces of coral rock with drilled holes and wooden wedges. Galvanized iron in any form did not answer, especially wire, as it quickly corroded. Most of the first plantings were lost by its use, and I am also inclined to condemn brass wire on account of the possible poisonous effects of the salts formed on it, although some of the best results were obtained when it was used. Having prepared the sinkers and hooked up sufficient sponge for several days' work, placing them in nets hung from the side of the schooner, the process was as follows : Take the poles or other sinker material in a small boat, two kedge anchors, a small long line, aud the sponge in buckets in which the water was changed every few minutes (in this connection, it has been generally understood that exposure to air and sun for even a few minutes was fatal to a sponge, and at first I was very careful in this respect: subsequently I found that several hours of such exposure did not hurt them to any extent: stagnant water, however, will kill them in a very short time), a cutting board and knife, the latter very thin and re-sharpened often, owing to the calcareous matter embedded in the sponge. Having reached the locality which was at first selected by the natural sponge growth already on it, the two kedges are let go at either end of the long line, and by hauling along this line the plantings could be kept quite regular, and when finished were marked by range stakes set up on the adjacent dry banks. The depth of water ranged from eight feet to less than one foot at low tide, at which latter depth many fine sponges are found. By the use of a water glass the plantings could be easily observed at any time without disturbing, them. In cutting the sponge it was done as AND THE ARTIFICIAL CULTURE OF SPONGES. 291 nearly as possible in a line with the radial circulating canals, and that each piece should have on it a part of the outer cuticle. As many were not cut this way, and lived, it may not be at all necessary. Each piece was about one inch square on top and somewhat more in length, coming to a point, averaging 25 to a sponge. In cutting care was taken not to express the natural juices or milk, and quickly attaching to the sinkers, were immediately put into the water. The poles held on an average 12 pieces placed 12 inches apart, and with one assistant I was able to plant about 200 cuttings per day. With a more suitable boat having a well to keep the sponge in, and another assistant, I could easily plant from 600 to 800. This work was continued with intervals from November, 1889, until June 11, 1891, with various results, under all the conditions of bottom, doptli, current, etc. With but few exceptions, the sponge survived the cutting process and began a good healthy growth, to be afterwards lost or destroyed in various ways. In many cases, notably one lot planted back of Elliott's Key in 4 feet of water on hard bottom, 75 per cent, lived and in 6 months had doubled in size ; these were mostly taken up before reaching maturity, as a gale would have swept them away, and did so with those that were left. Mature specimens were gotten from many of the other plantings, but the average loss from defective fasten- ings and other causes was greater. The results can be summed up as follows : Material for anchoring cuttings : While very many things other than those used suggested themselves in the progress of the work, I kept strictly within the limits of what was economic and practical, therefore poles and stone seemed best suited, preferably the former arranged so as to be elevated a short distance above the bottom to avoid smothering with silt, and to avoid the coral, etc., which is apt to grow in with the sponge. Fastenings of just the right character have yet to be invented. Location : Anywhere within the bays and lagoons free from heavy sea, too strong current, and too much fresh water, and in moderate depths for easy handling and observation. Growth : This is faster in strong currents, but shape is apt to be poor and quality harsh. This point, however, is not fully determined. Under favourable conditions the cuttings doubled their size in 6 months ; conse- quently, 18 months to 2 years will produce marketable sponge. The sheepswool was the only one of the useful kinds experimented on, although a few cuttings of velvet, grass, and others, seemed to thrive and do equally well. It is quite possible that with State protection to the planters, and better methods to be determined upon by further experi- ment, sponge culture might be ([uite profitable. My belief is, gained in oyster culture from spawn, that a similar method with sponge will 292 REPORT ON THE SPONGE FISHERY OF FLORIDA. eventually prove the correct one, but until more is known of sponge biology it would be useless to suggest methods, notwithstanding the fact that several points in connection with it have been to my mind quite clearly demonstrated. Unfortunately, having had to turn my attention to matters of more immediate pecuniary return, the subject has remained in abeyance. Very respectfully yours, (Signed) Ralph M. Monroe." [ 293 ] Variations and Relationship of the Flounder and the Plaice.* By F. B. Stead, B.A. There can be no question of the importance of the subjects treated of in this paper ; and the results are certainly such as to attract attention. This fact makes it all the more disappointing that the author's method is not calculated to inspire confidence in the accuracy of his conclusions. Before attempting to j ustify this statement, we may give a brief account of the paper as it stands. After giving an extensive bibliography, the author passes on in his second chapter to a statement of the method of the investigation, and of the notation by which he finds it necessary to state his results. In tlie next chapter a table is given showing the extent of variation of particular characters in the species considered, and the degree in which the variations of these same characters in both forms may coincide. The influence of sex and age, and the character and development of the scales, is next treated of, and the following chapter is devoted to a statement of the differences which obtain between the different " local forms" in the North Sea and the Baltic. The rest of the paper is taken up with a consideration of the relations between the local forms and the species, an account of Pleuronedes psevdojlesus, certain morpho- logical and biological observations, and a summary of results. We may now consider the more important parts of this paper in detail, The method of investigation consisted in examining "a large number" of specimens of each species in respect of no less than thirty-six characters. Of these eleven were finally selected as sufficing to dis- tinguish the species one from another, as well as the individual forms of each species from different localities. * "Variation uud Verwandschart von. I'l. Ilesus L. und PI. platessa L., iinlcrsuclit mittelst dcr Heiiicke'schen Methode," von Georg Duncker. IVis-i. Mccrcsuntersuch hrrnusgegcbcn von d. Komm. znr Wiss. Untersuch d. dentschen Mcore in Kid. Hcfl. 2, 1896. 294 VARIATIONS AND RELATIONSHIP OF These characters were the number of vertebra? in the caudal peduncle and in the tail, the number of vertebra? which have no median ha^mapophysis, and the total number of vertebra?; the number of liu rays in the dorsal and anal fins ; the length of the caudal peduncle, and its mean height ; the total length of the body without the caudal fin ; the length of the head on the ocular side ; and the number of branchiostegal rays. In order to eliminate small errors of measurement, such as those which result from the shrinkage of specimens which have been preserved in spirit, and to give at the same time a clearer expression of the main facts of variation, the total range of variation in respect of each particular character was legitimately divided into a small number of arbitrarily selected divisions. Into one of these divisions a number of individuals, all varying slightly from one another, would then fall ; and the individuals in question would be regarded as identical in respect of the particular character examined. The author has, however, considered it necessary to adopt a notation to represent the " variation degrees " of each character, which makes his paper by no means easy to read. The several characters of particular individuals are represented by formula? which the reader has to inter- pret by reference to the chapter on the method employed, whenever they occur. Thus we are told that the " Extreme Flounder form " has characters represented by the formula 5 + 19 + 9 = 33. a a S a (1). Having explained his method, the author gives in his next chapter a table, in which the limits of variation for each particular character in the two species considered are indicated. In two forms so closely allied as the plaice and the flounder, a considerable part of the entire range of variation for any character is often common to the two species. The table given shows in an interesting manner the degree to which the variation ranges of the several characters are distinct in the two species. Thus the number of fin rays in the dorsal fin varies from 51-65 in the flounder, and from 61-80 in the plaice. The total range of variation is 30, and of these 30 possible variations there are 5 which are common to both species. This fact is expressed by saying that the percentage of variation common to the two species is 17 per cent. It is noteworthy that in respect of the depth of the body and the length of the head — the measurements in each case being expressed as percentages of the body length — there is no difference in the ranges of variation for the two species. Our author next deals with the infiuence of age and sex. This part of the subject appears to us to be somewhat inadequately treated. In dealing with local forms, the author states that he examined exclusively "the grown up" specimens ("erwachsenen materials") without defining THE FLOUNDER AND THE PLAICE. 295 the term. An examination of the tables given for plaice reveals the fact that the majority of tlie specimens examined varied in length from 20-30 cms, (about 8-12 in.). To assume that all these individuals were "grown up," and that the influence of age need not therefore be considered, is to assume what appears to us to require proof. Our author himself points out that the influence of age might be such as to lead an observer to erroneous conclusions with regard to the influence of locality. But he neither investigates the relation of differences in age to any particular character, nor does he examine for each locality a sullicient number of individuals of about the same size to render it probable that the differences due to variation in age may be safely left out of considera- tion. It is clear that if a sufficiently large number of forms of the same size were examined, the characters for flshes from each locality might be considered in relation to the most probable age for that size. But even so, the influence of the locality on the rate of growth would have to be determined. With regard to the influence of sex, our author states that in both species the females are always broader, and have longer heads than the males. In the males the number of vertebrae is somewhat smaller than in the females. The subject of the development of scales in the two species is next considered. To this we would draw special attention, as it is in respect of the character of the scales that the two species differ most strikingly from one another, and the author's observations on the point are distinctly interesting. It is pointed out, that in both species cycloid scales begin to develop (when the fisli is 1-5-20 cms. long) over the whole surface of the body, at the bases of the caudal fin rays, on the cheeks and on the prreoperculum. The plaice develops these scales on the ocular side along the inside rays of the dorsal and anal fins, and at the bases of the pectoral and ventral fins. The scales lie embedded in the skin, separated for the most part from one another, and it is only in particular parts, for instance the caudal peduncle on the ocular side, that they overlap. In the female plaice, development of scales rarely proceeds beyond this stage ; in the male, changes may occur after maturity has been reached, but these changes only consist in a transfor- mation of the cycloid scales into the ctenoid condition. In the flounder, on the other hand, the cycloid scales become transformed in various parts of the body into a ctenoid, and even more complicated condition, while the fish is still only 2-3 cms. long. The change of a cycloid into a ctenoid scale proceeds in the following manner : — The posterior edge of the scale becomes raised out of the enclosing epithelium, and a layer of hard transparent substance bearing spines is laid down over the surface of the scale. This layer, which is 29G VARIATIONS AND RELATIONSHIP OF divided presumably from the epithelium, travels forwards over the surface to its anterior edge, and spreads over part of the under surface posteriorly. When this process is complete the scale is said to have reached the Dor n- Stadium,. In the next chapter the author deals with the different local forms of the plaice and flounder from different localities in the North Sea and the Baltic. We do not propose to give a detailed statement of his conclusions, because it appears to us that the evidence on which these are based is quite insufficient. Taking the first locality dealt with as an example, we may note that the author diagnoses 20 male and 8 female flounders. He then takes the most common measure (in 28 individuals) for each character considered, and writes a formula which he calls Die Mittelformel fur die Konigsberge Form. Further, a table is appended in which the frequencies of the several variations of each character in the individuals examined is expressed in percentages of the total number of individuals. Thus we are informed that 55 'per cent, of the W male flounders from Konigsberg have 36 vertebrae. It appears to us that little reliance can be placed on conclusions which are drawn from an examination of so small a number of individuals : and it is simply misleading to express the results of such examination in percentages, when fewer even than a hundred individuals have been examined. The author proceeds to summarise his results by giving two formulte, expressing the characters of Baltic and North Sea flounders. We are not altogether sure what meaning the author attaches to these generalised formuhie. The formulae, assuming the results obtained for the separate localities to be accurate, express the most common measure- ments of the several characters in all the individuals examined from the Baltic and the North Sea, and they may be said to show how in a general way the flounders from these two regions differ from one another in respect to each of the several characters considered. But it would, we think, be a mistake to take these formulaj as expressing the combined characters of the ideal form which the environmental forces were tend- ing to produce in these seas. If it is desired to show the direction in which evolution is tending to transform these populations, account must be taken of the facts of correlation. In a paper on certain correlated variations in Carcinus mcenns* it has been pointed out by Weldon that before we can estimate the changes at present going on in a race or species, we must know, among other things, (a) the percentage of animals which exhibit a given amount of abnormality with regard to a particular character, and (&) the degree of abnormality of other organs, which accompanies a given abnormality of one. The ideal form of which * Weldon. I'roc. Roy. Soc, vol 54., p. 318. THE FLOUNDER AND THE PLAICE. 297 we spoke above is not to be got at by striking an average for each of the separate characters examined in the individuals from the region in question, but rather by determining not merely the amount of any abnormality, but also the degree to which it is associated with other abnormalities. We think we are right in saying that tlie laws of correlation do limit, and to some extent determine, the directions which evolution may take. In dealing with local forms, these considerations ought not to be ignored. We may make our point of view clearer by reference to the formulae given by our author, which denote what he calls the " extreme flounder form," or the " extreme plaice form." These formula are arrived at by taking the extreme variations of the several characters in the flounder and the plaice, contrasting them in this way as much as possible. The formulae thus obtained represent the sum of a number of separate possibilities ; but it by no means follows that the several extreme characters, which are separately possible, are possible in combination with one another in a single individual, and, in point of fact, as an examination of the tables shows, there is not a single instance of either of these extreme forms among the individuals examined by the author. Our author having, as the result of his investigation into the local forms, taken up the position that the relationship between the two species in the Baltic is closer than in the North Sea, finds support for this view in the existence of an intermediate form which inhabits the south-western part of the Baltic, and which was first described by Gottsche as a variety of the plaice, and named Plcuronectes pseudojlesus. This form differs from the flounder in having cycloid scales on its " blind side," and the ctenoid scales of the plaice on its ocular side. It differs, however, from the latter species, and approaches the former in having rows of scales on its lateral line, and on the bases of the dorsal and anal fin rays, which are more highly developed than the ctenoid scales, and represent, in fact, a stage in the development of the scales which is characteristic of the flounder. The question arises, whether it is an intermediate form or a hybrid. On the one hand, the fertility of the fishes would seem to point to the former hypothesis ; on the other, the mingling of the specific characters (of the flounder and the plaice), and the rarity of its appearance, would seem to support the latter. Our author inclines to support the latter view, in opposition to Mobius and Heincke, "ohne dass ich einen wissenschaftlichen grund hierfiir anzugeben vermcichte." A form has been described by Ekstrom and Smitt which is also intermediate between the flounder and the plaice, and differs very slightly from Fleuronectcs psendojlesus. This form, to which the name /'/. ijlaciaiis has been given, is found on tlie western part of the 298 VAUIATIONS AND RELATIONSHIP OF north coast of Xorth America, and on the north coasts of Asia and Europe. Attention may now be drawn to the hypothesis concerning the origin of these closely allied forms, which the author tentatively puts forward. It is pointed out in the first place that the Baltic may be considered intermediate between the North Sea and the Arctic Ocean, as regards the populations it contains. Further, the Baltic plaice, which differ from those of the North Sea in the smaller number of their vertebra3 and fin rays, and in the stronger and more conspicuous ctenoid scales which they possess (characters which may be said to be masculine), would, if these differences were intensified, come to resemble very closely the Arctic form PL glacialis. On the other hand, the flounder in the eastern part of the Baltic tends to vary in the direction of a greater number of vertebr;\i and fin rays, and these characters are feminine. PI. fjlacicdis may, then, be regarded as representing an extreme form of either the plaice with masculine characteristics, or the flounder whose characteristics tend to be feminine. Our author considers that of the forms under consideration, the ^^/^aVe, judging from the rudi- mentary development of its scales, is the oldest; that this form was originally confined to northern latitudes ; and that it wandered thence to the North Sea — without undergoing very much change ; and to the northern coasts of Europe and Asia, where it gave rise to the variety glacialis. At the same time an immigration took place into the Baltic, through the Gulf of Bothnia, which was then open to the North, and the plaice approximated to the glacialis type. As a result of the influence of a mild climate, PI. glacialis became transformed to a flounder-like form. This latter spread over the North Sea and the Atlantic coasts of North America, and gave rise to a number of varieties. In the meantime the original PI. glacialis of the Baltic disappeared, and this form only now remains in the more northern latitudes where it took its rise. It will be seen that this hypothesis attempts to account for the differences which obtain between the North Sea and Baltic plaice, and derives the flounder from a form like the plaice — the modern PI. glacialis being regarded as representing an intermediate stage in the evolution of the flounder. In conclusion, we may note that the author carefully refrains from discussing the causes which have given rise to the local varieties he describes. He does not even enter into the question whether the local dil'ferences arise in the ontogeny of each individual, as the result of the direct action of the environment, or whether they are inherited : in other words, he does not, so far as we can make out, commit himself as to the real nature of the local varieties — whether they are to be regarded THE FLOUNDER AND THE PLAICE. 299 as distinct races or no. He says not a word of Natural Selection or of Laraarckian factors. We are very far from being disposed to complain of these omissions. In his concluding paragraph the author justifies his research by showing that it points to this important fact, namely, that the morph- ology of an organism is not wholly dependent on internal formative forces — e.g., Heredity, and Variation due to internal causes — but is also directly influenced in a determinate manner by external, chemical, and physical forces. The author, unless we are much mistaken, is not here concerned with the causes of evolution : he is merely pointing to the fact that every individual is continually subject to external influences, which must have an effect on its structure, whether characters so acquired are inherited or not. And these external influences may act directly to produce certain modifications in the individual during its lifetime, or indirectly in deter- mining the incidence of selection, or in both of these ways. Leaving out, for the sake of argument, the possibility of inheritance of acquired characters, the external conditions must still be considered of the greatest import — a fact which will be appreciated when it is remem- bered that an individual cannot be rightly regarded as a naked bundle of characters transmitted from its parents, but as an organism endowed with certain inherited tendencies, and reacting during life to the con- ditions of its environment. There can be no question, then, of the value of research which is concerned with the examination of the efl'ects of external conditions. And this makes us regret all the more that the author was not as careful in establishing his facts on a sure basis as he is cautious in expressing his opinion on the theoretical aspects of tlie subject. [ 300 ] Director's Report. As I was able to announce in a postscript to my Report in the last number of the Journal, the Association has secured a small steam fishing yacht, which has already proved exceedingly useful in carrying on the work of the Laboratory. Towards the ^600 which was paid for the vessel, a little over £500 has now been subscribed. It is important that the remainder of the sum should be forthcoming, so that it may not be necessary to draw upon our small reserve fund for this purpose. The number of workers who have visited the Laboratory for the purpose of conducting independent researches has been maintained ; and at the same time the arrangement by which students are admitted to the Laboratory for the purpose of study, rather than of research, has been taken advantage of by a much larger number of students than was anticipated. The following is a list of Naturalists who have occupied research tables, and of the subjects which have engaged their attention : Brebner, G., September 5th, 1895 {Marine Al//cv). Itiches, T, H., b.a., January 13th (Development of Nemertines). Garstang, W., M.A., March 23rd to May 1st, July 22nd {Marine Bionomics). Church, A. H., b.a., April 1st to April 25th, July 8th {Marine Alrjce). Mac Munn, C. A., June 3rd to 17th {Blood of Fishes and Invertebrates). Cleve, P. T., Ph.D., July 2nd to 7th {Diatoms). Watase, S., Ph.D., July 3rd to 8th {Phosphorescence of Marine Animals). Weldon, W. F. 11, m.a., July 7th ( Variation of Crabs). Colcutt, Miss M. C, July 15th {Ilydroids). Beer, T., l*h.D., July 27th {Sense Organs of Crustacea). Scott, S. D., B.A., July 28th {Ascidians). Barnard, J. E., August 4th {Phosphorescent Bacteria). In addition to these, twenty students have attended the classes conducted by Mr. Garstaug. There is every reason to believe that such classes will become a regular feature of the work of the Laboratory, director's report. 301 and a useful adjunct to its activities in otbei- directions. Students attending the classes have the opportunity of taking part in the regular collecting work of the Association, and are thus enabled to obtain a good knowledge of marine animals under their natural conditions. The book which Mr. J. T. Cunningham has recently been preparing, on The Marketable Marine Fishes of the British Islands, is to be published for the Association by Messrs. Macmillan and Co., and will appear at an early date. This work, which it is hoped will meet a long-felt want, has been prepared with a view to bringing before the general reader, in a connected narrative form, the information contained in the numerous technical memoirs, which have appeared during the last few years, dealing with marine fishes, their habits, and modes of development. The book is liberally illustrated with process blocks, and should prove exceptionally useful to those who are interested in fishery ([uestions, either for profit or from the legislative point of view. E. J. Allen. August, 1896. [ 302 ] gUrrnr ^liologiciil |.$soriation of tjje 'J^lnitcb ^lingioni. Report of the Council, 1895-96. The Council. Four ordinary and two special meetings of the Council have been held during the year. The average attendance at the meetings has been 9"5. A sub-committee of the Council visited and inspected tlie Plymouth Laboratory on June 6th. No vacancy has occurred on the Council itself during the year, but the Council has to deplore the loss of Prof. Huxley, tlie first President, to whose efforts the successful launching of the Association, and the assistance which it lias received from the Government, the City Companies, and other public bodies, were largely due. The Council has to again thank the Eoyal Society and the Linnean Society for permitting the meetings of the Association to be held in their rooms. The Plymouth Laboratory. Considerable expense has been incurred during the year in repairing the engines and pumps which supply sea-water to the Aquarium. The fact that a circulation has to be continuously maintained causes con- siderable wear and tear, and constant repairs are necessary to ensure against the possibility of a breakdown. The buildings, fittings, and machinery of the Laboratory are in good condition. The Boats. For the first nine months of the year the ordinary collecting work of the Laboratory was done by the sailing -boat Anton Dohrn, supple- mented from time to time by hired steam tugs. For the fishery investigations conducted by Mr. Stead a small sailing trawler was hired. The steam-launch Pansy has been sold to her former owner, and in February last the Association purchased the steam fishing yacht Bustj Bee from Mr. Treffry, of Fowey. This boat, which is GO feet long, and has a gross tonnage of 22*5, is well adapted to the ordinary work of the Association, and is as large a vessel as it would be possible to maintain RErORT OF THE COUNCIL. 303 on our present income. The vessel is in good condition, and it is hoped that she may do good work for the Association for some years to come. Museum. Progress has been made in the re-arrangement of the type collection of the local fauna for the Museum, and several of the more important groups are almost complete. The herbarium has also been largely augmented during the year, and should prove valuable to botanists who visit the Laboratory. The Staff. The only alteration which has taken place in the staff since the last Annual Meeting has been the appointment of Mr. T. V. Hodgson to the post of Director's Assistant. Mr. Cunningham still continues to devote himself to investigations connected with the North Sea fisheries, though the Council have to regret that up to the present no special donation has been forthcoming to provide for the continuation of this work. It is in the direction of an increase in the number of naturalists employed by the Association that we must look for future developments of our work. Now that a more suitable steamboat has been procured, the Laboratory and its appliances may be regarded as sufficiently complete to allow of a much larger amount of useful work being turned out, if a sufficient number of workers can be engaged for lengthened periods. The Library. Although that portion of the Library which comprises the literature relating to Sea Fisheries may be regarded as fairly complete, a con- siderable sum of money will have to be spent before an equally favourable report can be made of the supply of literature dealing with scientific zoology and botany. Not only are we unable, with our present income, to procure regularly many of the important journals, which should find a place in a Library such as ours, but back numbers of journals to which we now subscribe are in many cases deficient. Through the kindness of Sir William Flower, one such defect has been remedied during the year by the completion of our set of the Philo- sophical Transactions of the Eoyal Society from the year 18G6. The thanks of the Council are due to the Eoyal Society, the Zoological Society, the Eoyal ]\licroscopical Society, and numerous other societies and individuals, at home and abroad, for copies of their publications, by gift or exchange, which have been received. NEW SERIES.— VOL. IV. NO. 3. Y 304 REPORT OF THE COUNCIL. General Report, Mr. Cunningham's memoir on the natural history of marketable food fishes, to which reference was made in the last Report, having assumed a larger and more complete form than was at first intended, it has been decided to issue it as a book. The work will be very fully illustrated, and arrangements have been made by which it will be published for the Association by Messrs. Macmillan and Co. During the summer of last year Mr. Cunningham, in addition to a prolonged stay at Grimsby, visited Scarborough, Lowestoft, and other fishing centres on the East Coast, and by thus extending the field of observation, was able to supplement the work done by Mr. Holt in some important particulars. Mr. Stead has been carrying out trawling experiments in the Bays on the South Coast of Devon, which are at present closed to trawlers, with a view to determining the nature of the fish populations which they contain at various times of the year. The ordinary dredging and trawling work carried on from the Plymouth Laboratory has been extended to the deeper water between the Eddystone Eocks and Start Point, and material is being collected for the compilation of a detailed chart of the various grounds iu this area, showing the nature of the bottom and the kinds and proportions of the inhabitants at each spot. Occupation of Tables. The following naturalists engaged in research work have occupied tables in the Plymouth Laboratory during the year : P. Barthels, Ph.D., Bonn (Ecliinodermata). W. I. Beaumont, B.A., Cambridge (Faunistic Researches). A. Bethe, Ph.D., Berlin (Nervou.'* System of Crustacea). G. Bidder, M.A., Camlnidge (Sj^onges). G. Brebner, Royal College of Science (Marine Alga;). E. T. Browxe, B.A., University College, London (Medusae). A. H. Church, B.A., Oxford (Marine Alga)). W. Garstang, M.A., Oxford (Marine Biononucs). J. D. Gilchrist, B.Sc. Ph.D., Edinburgh (Nervous System of Mollusca). T. V. Hodgson, Mason College (Anijiliij)oda). T. H. Riches, B.A., Camljridge (Development of Nemertines). T. H. Taylor, M.A., Yorkshire College, Leeds (Polyzoa), W. F. R. AVeldon, M.A., University College, London (Variation of Crabs). An important development of the usefulness of the Laboratory has been made by tlie establishment of vacation classes for advanced university students. Courses of study iu Marine Biology have been conducted by Mr. W. Garstang, who was for many years a member of the Association's staff. Eighteen students have taken advantage of this arrangement during the year, the class held at Easter numbering fifteen. REPORT OF THE COUNCIL. 305 To accommodate this class a room on the ground-floor of the east block of the building has been specially fitted up, so that research workers in the large laboratory are in no way interfered with. It is believed that by thus arousing interest in marine investigations before the students have completed their university course, many of them will be likely to subsequently use the Laboratory for the purpose of scientific research. Amongst the papers, either wholly or in part the outcome of work done in the Laboratory, which have appeared elsewhere than in the Journal of the Association, are the following : Allen, E. J. — Studies on the Nervous System of Crustacea: Quart. Journ. Micr. Sci. xxxix. p. 33. Barthels, p. — Notis uber die Excretion der HolotMirien. Zool. Anzeiger, No. 492. 1895. Bidder, George. — The Collar-cells of Heterocoela. Quart. Journ. Micr. Sci. xxxviii. p. 9. Browne, E. T. — On the Variation of Haliclystus octoradiatus. Quart. Journ. Micr. Sci. xxxviii. p. 1. Garstang, W. — Budding in Tunicata. Science Progress, iii. March, 1895. Garstang, W. — Outlines of a new Classification of the Tunicata. British Asso- ciation. Ipswicli. 1895. HiCKSON, S. J. — The Anatomy of Alcyonium digitcdum. Quart. Journ. Micr. Sci. xxxvii. p. 343. MacBride, E. W. — The Development of Asterina gibbosa. Quart. Journ. Micr. Sci. xxxviii. -p. 339. Nutting, C. C — Notes on the Reproduction of Plumularian Hydroids. Amer. Naturalist, Nov., 1895, p. 966. Donations and Receipts, The Eeceipts for the year include the annual grants from H.M. Treasury (£1000) and the Worshipful Company of Fishmongers (£400), a special donation from Mr. T. H. lliches (£30), annual subscriptions (£153), rent of tables in the Laboratory (£89), sale of specimens (£250), and admission to the Aquarium (£76). In addition to these amounts, the following sums have been promised towards the £600 required for the purchase of the steam yacht BiLsy Bee : Fishmongers' Company . . . . £105 The Royal Society . . . . £100 J. P. Thomasson, Esq. . . . . £100 Drapers' Company . . . . £52 10s. Grocers' „ .... £50 Mercers' „ .... £26 5s. Goldsmiths' „ .... £20 EarlDucie £10 Sir Henry Thompson .... £10 W. I. Beaumont, Esq. . . . £1 Is. making a total of £474 16s. for this purpose. The total receipts for the year from all sources amount to £2419. 306 REPORT OF THE COUNCIL. Vice-Presidents, Officers, and Council. The following is the list of gentlemen proposed by the Council for election for the year 1896-97 : — President. Prof. E. Ray Lankester, LL.D., F.R.S. Vice-Presidents. The Duke of Argyll, K.G., K.T., F.R.S. The Duke of Abercorn, K.G., C.B. The Earl of St. Germans. The Earl of Morley. Tlie Earl of DuciE, F.R.S. Lord Revelstoke. The Right Hon. Lord Tweedmouth. Lord Walsingham, F.R.S. The Right Hon. A. J. Balfour, M.P., F.R.S. The Right Hon. Joseph Chamber- lain, M.P. The Right Hon. Sir John Lubbock, Bart., M.P., F.R.S. Prof. G. J. Allman, F.R.S. Sir Edward Birkbeck, Bart., M.P. Sir Wm. Flower, K.C.B., F.R.S. A. C. L. GiJNTHER, E.s(i., F.R.S. Prof. Alfred Newton, F.R.S. Rev. Canon Norman, D.C.L., F.R.S. Sir Henry Thompson. Rear- Admiral Wharton, C.B., F.R.S. F. E. Beddard, Esq., F.R.S. Prof. F. Jeffrey Bell, F.Z.S. G. C. Bourne, Esq., F.L.S. Sir John Evans, K.C.B., Treas. R.S G. Herbert Fowler, Esq. S. F. Harmer, Esq. Prof. W. A. Herdman, F.R.S. Elected Members. Prof. S. J. HiCKSON, F.R.S. J. J. Lister, Esq. John Murray, Esq., F.R.S. P. L. ScLATER, Esq., F.R.S., Sec. Z.S. D. H. ScoTT, Esq., F.R.S. Prof. Charles Stewart, F.R.S. Prof. W. F. R. Weldon, F.R.S. Hon. Treasurer. E. L. Beckwith, Esq. Hon. Secretary. E. J. Allen, Esq., The Laboratory, Citadel Hill, Plymouth. The following Governors are also members of the Council : — Robert Bayly, Esq. J. P. Thomasson, Esq. The Prime Warden mongers' Company. E. L. Beckwith, Esq. Company). of the Fish- (Fishmongers' Prof. BuRDON Sanderson, F.R.S. (Ox- ford University). Prof. Michael Foster, F.R.S. (Cam- bridge University). Sir William Flower, K.C.B., F.R.S. (Brit. Assoc, for Advmnt. of Science). [ 207 ] ^ Oi n n c o o o « 4 =»J >.-: X ■^ O X C O M — o cc C' vo o c t^ i 05 Tf C<: 13 O — CO -H « t^ O O O Ir- c; -^ S<5 o C ^> CO a S ,jn *-■ w o itOOOO(NO icooicoooooc^io 1— O ■* (N I t^ooox CO O cc o CO ■* t- (M CO CO 00 ■^^ II to (M o GO - c4 cc !>• CO X CO o CO o w 5 » K 5 i s &< Q . - coHcoO ■13 s 5 a a ■ '^ cS I S ^ G S ^ I •'^ o — — S C ' "^ 3 3 ^ a o t^O .« r; := o o f^ ■> o ^ O ■* cs r- O ci as CO o X 'O (N m a o — — qj a 1^ -^ C 3 03 o tJD .2 o aj O CO c« s Y 2 [ 308 ] LIST GF ^Qbtxmxs, ifounbcrs, antr |tlembers. 1st august, 1896, I.— Governors. The British Association for the Advancement of Science^ 22", Albe- marle Street, TV. £500 The University of Cambridge £500 The Worsliipful Comj^any of Clothworkers, 41, Mincing Lane, E.G. £500 The Worshipful Company of Fishmongers, London Bridge £39(15 The University of Oxford £500 Bayly, Robert, Torr Grove, Plymouth £1000 Bayl}', John (late), Seven Trees, Plymouth £000' Thomasson, J. P., Woodside, near Bolton £950 II.— Founders. * Member of Council. f Vice-President. t President. 1884 The Corporation of the City of London £210 1888 The Wor.sliipful Company of Drapers, Drapers' Hall, E.G. £315 1884 The Worshipful Company of Mercers, Mercer^ Hall, GJieapside £341 5s. 1884 The Worshipful Company of Goldsmiths, Goldsmiths' Hall, E.G. £100 1889 The Worshipful Company of Grocers, Poultry, E.G. £ 1 20 1884 The Royal Microscopical Society, 20, Hanover Square, W. £100 1884 The Hoy nl Society, Burlington House, Piccadilly, W. £350 1884 The Zoological Society, 3, Hanovei- Square, W. £100 1884 Bulteel, Thos., Radford, Plymouth £100 1884 Burdett-Coutts, W. L. A. Bartlett, 1, Stratton Street, Piccadilly, W.... £100 1888 Bury, Henry, M.A., Trinity Gollege, Camhridge £100 1884 Cri.sp, Frank, LL.B., B.A., Treas. Linn. Soc, 17, Throgmorton Avenue, E.G. £100 1884 Danbeny, Captain Giles A., 30, Gormvallis Grescent, Clifton, Bristol ... £100 1884 Eddy, J. Ray, The Grange, Carleton, Shipton, Yorkshire £100 1884 Gassiott, John P., The Culvers, Carshalton, Surrey £100 ♦*1884 Lankester, Prof. E. Ray, F.R.S., University Museum, Oxford £100 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 309 1885 Derby, the Rt. Hon. the late Earl of, K.G £100 1884 Lister, S. CuulifFe, Sicinton Park, Masham, Yorkshire £100 tl884 Lubbock, The Rt. Hon. Sir John, Bart., M.P., F.R.S., Hujh Elms, Bromley, Kent £100 1884 Poiilton, Prof. Edward B., M.A., F.R.S., Wykeham House, Oxford ... £100 tl889 Revelstoke, Lord, Memhlaml, Yealmpton, S. Devon £100 1890 Riches, T. H., B.A., Incjlenook, Yelverton, S. Devon £130 1884 Romanes, G. J., LL.D., F.R.S. (late) £100 tl889 Thompson, Sir Henry, 35, Wimpole Street, W. £110 *1887 Weldon, Prof. W. F."r., F.R.S., 30a, Wimpole Street, W. £100 1884 Worthington, James (late) £100 III.— Members. ann. signifies that the Member is liable to an Animal Subscription of One Guinea. C. signifies that he has paid a Composition Fee of Fifteen Guineas in lieu of Annual Subscription. 1884 A\gev,\^.ll., Manor House, Stoke, Devonport C. +1884 Allman, Prof. G. J., F.R.S., Ardmore, Parkstone, Dorset £20 *1895 Allen, E. J., B.Sc, The Laboratory, Plymouth ann. 1889 Anderson, Dr. John, 71, Harrington Gardens, S.JV. £20 +1884 Argyll, The Duke of, K.G., Argyll Lodge, Kensington, Jr. C. 1885 Armstrong, Lord, C.B., F.R.S., Crar/ SM?e, i?of/i5un/ G. 1893 Ascroft, R. L., 11, Park Street, Lytham, Lanes ann. 1892 Assheton, R., Birnarn, Gamhridge £20 1890 Badger, A. B., B.A., Glenleigh, Oakfield Road, Balsall Heath, Bir- mingham ann. 1884 Bailey, Charles, F.L.S., Ashjield, Gollege Road, Whalley Range, Man- chester ann. 1893 Bailey, W. E., Forth Enys Museum, Penzance G. 1884 Balfour, 'PTotBsij\ey,F.R.Q., Royal Botanic Gardens, Edi7ihurgh C. 1893 Bassett-Smith, P. W., Staff-Surgeon, R.N., H.M.S. Magdala, Bombay... ann. 1884 Bateson, Wm., F.R S., St. John's College, Gamhridge aim, 1884 Bayliss, W. Maddock, B.Sc, 52, Hamilton Terrace, London, N.W. ann. 1884 Bayly, Miss, Sef<;u Trees, Plymouth £50 1884 Bayly, Miss Anna, Seven Trees, Plymouth £50 1884 Beaumont, W. L, Angel Hotel, Knutsford ann. 1885 Beck, Conrad, 68, CoDi/wW, £. a G. *1889 Beckwith, E. L., The Knoll, Eastbourne arm. ♦1887 Beddard, F. E., F.R.S., Zoological Societtj's Gardens, Regent's Park, N.IF. ann. 1884 Beddington, Alfred H., 8, Gornwall Terrace, Regent's Park, N.W. G. *1884 Bell, Prof. F. Jeffrey, 35, Gamhridge Street, Hyde Park, W. ann. 1887 Berrington, A. D., i/oti re/ o/ Traf^t', Whitehall, S.W ann. 1890 Bidder, George, B.A., Ravensbury Park, Mitcharn, Surrey G. 1885 Bignell, Geo. Carter, F.E.S., 85, Union Street, Stonehouse, Plymouth ... ayin. +1885 Birkbeck, Sir Edward, Bart., M.P., 10, Gharles Street, Berkeley Square, W. ann. 1893 Bh'S, A. J. S., Palm Hou.te, Higher Broughton, Manclieder ann. 1889 Bolitho, T. B., M.P., Treuidden,Pen-Mnce ann. 310 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 1 884 Bompas, G. C. , 121, JFestbourne Terrace, Hyde Park aim. 1 884 Bosse y, Francis, M. D , Mayfield, Redhill, Surrey ann. 1884 Bostock, E., iitone, Staffordshire ann. 1890 Bourne, Prof. A. G., F.R.S., Tlie Prcddcnaj College, Madras ann. *1884 Bourne, (j\\\)QVt C, New Colleye, Oxford ann. 1886 Brent, Francis, F.S.A., 6, Tothill Avenue, Plymouth ann. 1895 Bridge, Prof. T. W., Mason College, BirmingJmm ann. 1890 Brindley, H. H., M.A., St. John's College, Cambridge ann. 1886 Brooksbank, Mrs. M., Leigh Place, Godstone, Surrey C. 1884 Brown, Arthur W. W., 6, Sussex Square, W. C. 1893 Browne, Edward T., 141, Uxbridgc Road, N.JV. ann. 1893 Buchanan, Miss Florence, TJie Miiseum, Oxford ann. 1884 Buckton, G. B., JVeycombe, Haslemere ann. 1886 Bullar, Miss Anna K., Westbourne Hill, Southampton ann. 1887 Burd, J. S., Cresswell, Higher Compton, Plymouth ann. 1889 Burnard, Robert, 3, Hillsborough, Plymouth ann. 1884 Caine, H. T., 5, Upper Wimpole Street, London, TV. C. 1884 Caine, W. S., Tlie Terrace, Clapham Common, S.JV. £ 21 1887 Caldwell, W. H., 12, Harvey Road, Cambridge C. 1887 Carter, James, F.G.S., 30, Petty Cury, Cambridge ann. tl884 Chamberlain, Rt. Hon. J., M.P., 40, Princes Gardens, S.W ann. 1884 Christy, Thomas Howard, Malvern House, Sydenham ((un. 1887 Clarke, Rt. Hon. Sir E., Q.C., M.P., 5, Essex Court, Temple, E.G. £25 1884 Clay, Dr. R. H., IVindsor Villas, Plymouth ann. 1885 Clerk, Major-Gen. H., F.R.S., 40, St. Ermin's Mansions, Caxton Street, S.JV..] £21 1 886 Coates and Co., Southside Street, Plymouth G. 1885 Collier Bros., Old Town Street, Plymouth C. 1890 Cook, C. H., M. A., Elmlea, South Stoke, Reading aim. 1895 CoTderoy, A., IS, Athenceum Street, Plymouth ann. 1889 Grossman, Major-General Sir William, K.C.M.G., Cliesunck, North- %imberland ann. 1885 Darwin, Francis, F.R.S., Wychfield, Cambridge G. 1 885 Darwin, W. E., Ridgemount, Bassett, Southampton £ 20 1889 Davies, H. R., Treborth, Bangor ann. 1889 Deacon, J. Barrington, 11, Osborne Place, Plymouth ann. 1885 Dendy, Arthur, D.Sc, Victoria University, Melbourne ann. 1884 Dewick, Rev. E. S., M.A., F.G.S., 26, Oxford Square, Hyde Park, W. ... G. 1885 Dixey, F. A., M.A., Oxon., Wadham College, Oxford £26 5s. and ann. 1890 Driesch, Hans. Ph.D., Stazione Zoologica, Napoli G. tl889 Ducie,TheRt.Hon.theEarlof,F.R.S., TortworthCourt,Falfidd,R.S.O. £50 15s. 1884 Dunning, J. W., 4, Talbot Square, W. £26 5s. 1884 Dyer, W. T. Thiselton, M.A., C.:M.G., F.R.S., Director of the Royal Gardens, Kew G. "■) 1893 Edward, Stanley, F.Z.S., Kidbrouk Lodge, Blackheath, S.E ann. 1891 Ellis, Hem. Evelyn, AVsenajs, Z>aic/ifc'<, Wiiidsor G. 1893 Enys, John Davies, Enys, Penryn, Gormcall ann. *1884 Evans, Sir John, D.C.L., Treas. Roy. Soc, Nash Mills, Hemel Hempstead £20 1885 Ewart, Prof. J. Cossar, M.D., University, Edinburgh £25 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 311 1884 Fayrer, Sir Joseph, Bart, M.D., F.R.S., 53, Wimpole Street , W ann. 1894 Ferrier, David, M.A., M.D., F.R.S., 34, Cavendish Square, W ann. 1884 Fisou, Frederick W., Greenholme, Burley-in- Wharf edale, Leeds C. *tl884 Flower, Sir W. H., K.C.B., F.R.S., Director of the British Museum of Natural History, Cromwell Road, S.W. G. *1885 Fowler, G. Herbert, B.A., Ph.D., 12, South Square, Gray's Inn, W.G.... ann. 1884 Fox, George H., JFodehouse Place, Falmouth ann. 1 889 Fraser, James, Tregarthyn, Eton Avenue, N.W ann. 1886 Freeman, F. F., Abbotsfield, Tavistock, S. Devon C. 1884 Fry, George, F.L.S., Carlin Brae, Bervnck-on- Tweed £ 21 1884 Fryer, Charles E., Board of Trade, S.W. ann. 1892 Gdlion,Y.,'F.'R.^., A2, Rutland Gate, S.W. ann. 1885 Gaskell, W. H., F.R.S., The Uplands, Shelford, Cambridge C. 1885 Gaskell, E. H., North Hill, Hiyhgate, N. C. 1893 Gatty, Charles Henry, LL.D., F.L.S., Felbridge Place, East Grinstead... G. 1884 Gibson, Ernest, F.Z.S., c/o Fraser, Stoddart, and Ballingall, 16, Castle Street, Edinburgh ann. 1884 Gonne, William £26 5s. 1885 Gordon, Rev. J. M., St. John's Vicarage, Redhill, Swrey anii. 1885 Gotch, Prof. F., F.R.S., University Museum, Oxford ann. 1888 Goiildmg,F.'ii., George Street, Plymouth C. 1884 Grove, E., Norlington, Preston, Brighton rt?m. 1884 Groves, J. W., c/o Rev. J. Farmer, Ongar Rectory, Sussex an7i. tl884 Giinther, Dr. Albert, F.R.S., 2, Lichfield Road, Kew Gardens a?m. 1884 Haddon, Prof. Alfred C, M.A., Innisfail Hill Road, Cambridge ann. 1884 Halliburton, Prof. W. D., M.D., B.Sc, King's College, Strand, W.C. ... ann. 1884 Hannah., Jiohiivt, 82, Addison Road, Kensington, W. C. *1885 Karmer, S>. ¥., King's College, Cambridge C. 1889 Harvey, T. H., Cattedoivn, Plymouth ann. 1888 Hasehvood, J. E., 3, Lennox Place, Brighton C 1884 Raslam, 'M.iss E. 'Rosa, Ravensivood, Bolton £20 1884 Hayne, C. Seale, M.P., 6, Ujyper Belgrave Street, S.W. ann. 1884 Head, J. Merrick, F.R.G.S., J.P., Ardverness, Reigcde ann. 1 884 Heape, Walter, Heyroun, Chaucer Road, Cambridge C. 1887 Heath, Miss A., Yelverton ann. *1884 Herdman, Prof. W. A., F.R.S., University College, Liverpool ann. 1884 Herschel, J., Col., R.E., F.R.S., Observatory House, Slotogh, Berks C. 1884 Heywood, James, F.B..S.,2G, Palace Gardem, W. C. 1889 Rtiyviood, Urs. E. S., Light Oaks, Manchester C *1884 Hickson, Prof. Sydney J., M.A., D.Sc, F.R.S., Ellesmere House, Wilenslow Road, Withington, Manchester ann. 1884 Holdsworth, E. W. H., F.L.S., F.Z.S., Lucerne House, Dartmouth ann. 1893 Holt, Mrs. Vesey W., 104, Elm Park Gardens, S.W. ann. 1889 Howell, Mrs. F. Bullar, Ethy, LostwUhiel ann. 1887 Howes, Prof. G. Bond, F.L.S., Science and Art Department, So%tth Kensington t*""- 1884 Hudleston, W. H., M.A., F.R.S., 8, Stanhope Gardens, South Kensing- ton, S.W. ann. 1885 Hurst, C. Herbert, Ph.D., Royal College of Science, Dublin C. 312 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 1891 Imliau Museuin, Calcutta, 65, Cornhill aim. 1888 Iiiskip, Capt. G. H., R.N., 22, Torrington Place, Plymouth ann. 1893 Jago, 'Edward y Mcnlieniot, Cornwall ann. 1887 Jago-Trelawny, Ma']ov-Gen., F.'R.G.S., Coldrenick, Liskeard C. 1890 Johnson, Prof. T., D.Sc, F.L.S., Ruijal College of Science, Dublin ann. 1892 Joshua, Mrs., 57, Cadogan Square, S.W ann. 1894 Justen, F. W., F.Z.S., c/o Dulau and Co., 37, Soho Square, W ann. 1884 Kellock, W. B., F.L.S., F.R.C.S , 94, Stamford Hill, N. ann. 1884 Kent, A. F. S., Physiological Laboratory, St. Thomas's Hospital, S.JV. ... ann. 1885 Langley, J. K, F.R.S., Trinity College, Cambridge G. 1885 Lea, A. S., M. A., Caitis College, Cambridge ann. *1895 Lister, J. J., M.A., St. John's College, Cambridge cmn. 1884 London, The Lord Bishop of. The Palace, Fulham, S.JV. aim. 1888 Lopes, The Rt. Hon. Sir Massey, Bart., Maristoiv, Roborough, South Devon ann. 1885 Macalister, Prof. A., F.R.S., St. John's College, Cambridge ann. 1884 Mackrell, John, High Trees, Clapham Common, S.JV C. 1886 MacMunn, Charles A., Oak Leigh, JVolverhampton ann. 1889 IMakovski, Stanislaus, Fairlaiun, Red Hill ann. 1885 I\Iarr, J. E., M. A., St. John's College, Cambridge C. 1884 Mason, Philip Brookes, i)Mrfo>i-o?i-rre?tf ami. 1884 McAndrew, James J., Lukesland, Loybridge, South Devon ann. 1884 Mcintosh, Prof. W. C, F.R.S., 2, Abbotsfurd Crescent, St. Andrews, N.B. C. 1894 Meryon, Capt. J. E., R.N., H.M.S. Katoomba, Australian Squadron ann. 1884 Michael, Albert D., Cadogan Mansions, Sloane Square, S.JV. C. 1885 Mitchell, P. Chalmers, B.A., 79, Portsdown Road, Maida Vale ann. 1885 Mocatta, F. H, 9, Connaught Place, JV. C. 1886 Mond, Ludwig, F.R.S., 20, Avenue Road, Regent's Park, N.JV. C. 1884 Morgan, Prof. C. Lloyd, University College, Bristol ann. 1891 Morgans, Thomas, Tlie Guildhall, Bristol ann. tl889 Morley, The Rt. Hon. the Earl of, 31, Prince's Gardens, S.JV. ann. 1885 Morris, John £21 1885 Morrison, Alfred, 16, Carlton Hov.se Terrace £52 10s. tl884 Newton, Prof. Alfred, M.A., F.R.S., Magdalen College, Cambridge £20 tl884 Norman, Rev. Canon, M.A., D.C.L., F.R.S., Houghto7i-le- Spring Rectory, Co. D urham ann. 1884 Ommanney, Admiral Sir Erasmus, K.C.B., F.R.S., 29, Connaught Square, W. ann. 1885 Paget, Sir James, Bart., F.R.S., 5, Park Place, JF. C. 1884 Parsons, Chas. T., Norfolk Road, Edgbaston, Birmingham ann. 1888 Peek, Sir Henry W., Bart., F.Z.S., JVimbledon House, JJ^imbledon C. 1888 Pennsylvania, University of, Philadelphia, U.S. A ann. LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 313 1885 Pliillips, Chas, D. F., M.D., ID, Henrietta Street, Cavendish Square, JV. C. 1887 Phipson, Mrs., Cuniballa Hill, Bombay ann. 1895 Pinwill, Cai^t. Trehane, Probus, Cormoall ann. 1 885 Pocliin, H. D. , Bodua nt Ha II, Eghvysbach, Denb ighsliire G. 1886 Power, Henry, F.R.C.S., 37a, Great Guniberland Place, W. ann. 1885 Pritchard, Prof. Urban, 26, JVimiwle Street, W. ann. 1884 Pye-Smith, P. H., M.D., 54, Harley Street, W. G. 1893 Quintin, St. W. H., Scampstone Hall, liillington, YorJcs ann. 1884 'Radiord, Darnel, Mount Tavy, Tavistock ann. 1884 Ralli, Mrs. Stephen, 32, PrtrZ; ia«e, JF. £30 1 885 Ransom, W. B. , The Pavemen t, Nottingham G. 1893 Raslileigh, E. W., Kilmarth, Par Station, Gormmll ann. 1888 Rawlings, Edward, liichmond Bouse, Wimbledon Gommnn ann. 1892 Robinson, Miss M., University Gollege, London, JV.C. ann. 1892 RiifFer, M.A., M.D., Bactereological Institute, Cairo ann. 1888 ScliarfF, Robert F., Ph.D., Science and Art Museum, Dublin ann. *1884 Sdater, P. L., F.R.S., Sec. Zool. Soc, 3, Hanover Square, JV ann. 1884 Sclater, W. L., The Museum, Cape Toion ann. *1885 Scott, D. H., M.A., Ph.D., F.R.S., Old Palace, Richmond, Surrey 0. 1884 Sedgwick, A., M.A., F.R.S., Whitejlcld, Great Shelford, Cambridge C. 1888 Serpen, E. W., 19, Bill Park Crescent, Plymouth £50 1885 Sheklon, Miss Lilian, Oldall, Neionham College, Cambridge ann. 1884 Shipley, Arthur E., ^I. A., Christ's Gollege, Cambridge C. 1886 Shore, T. W., M.D., The Warden's House, St. Bartholomew's Hospital, E.G. ann. 1894 Simpson, F, C, J.P., Maypool, Churston Ferrers, B.S^O ann. 1885 Sinclair, F. G., New Museums, Cambridge G. 1891 Sinclair, William F., 102, Cheyne Walk, Chelsea, S.W. C. 1884 Skinners, the Worshipful Company of, Skinners' Hall, B.C. £42 1889 Slade, Commander, E. J. Warre, H.M.S. Cockatrice, Mediterranean Station G. 1884 Sladen, W. Percy, 13, Hyde Park Gate, S.W ann. 1893 Sorby, H. C, LL.D., F.R.S., Broomfield, She field ann. 1888 Silencer, Prof. W. Baldwin, M.A., University of Victoria, Melbourne ... ann. 1884 Spring-Rice, S. E., C.B., 1, Bryanston Place, Bryanston Square, W. ... G. *1884 Stewart, Prof. Chas., F.R.S., Royal College of Surgeons, Lincoln's Inn Fields, W.C. ann. 1884 Sutherland, The Duke of, K.G., Stafford House, St. James', S.W. G. 1894 Sykes, E. R., 3, Gray's Inn Place, Gray's Inn, London, W.C. a?in. 1 894 Thomas, W. F. , Bishopshalt, Hillingdon, Middlesex ann. 1890 Thomp.sou, H. F., B.A., 35, Wimpole Street, W. ann. 1884 Thornycrof t, John I., Eyot Villa, Chiswick Mall ann. 1888 Thurston, Edgar, Government Central Museum, Egmore, Madras ann. 1888 Tripe, Major-General, 3, Osiorne Villas, Stoke, Devonport ann. 1888 Valleutin, Rupert, 18, Kimberley Road, Falmouth ann. 1 891 Vaughan, Henry, 28, Cumberland Terrace, N.W. ann. 314 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 1884 Venning, Mrs., 3, Wingfield Villas, Stoke, Devonport £50 1884 Vines, Professor Sydney H., M.A., D.Sc, F.R.S., Botanical Gardens, Oxford ann. 1884 Walker, Alfred 0., Nantyglyn, Cokinjn Bay, N. Wales ann. 1884 Walker, P. F., 36, Princes Gardens, S.W. ajm. 1893 Walker, W. H., 3, Princess Place, Plymouth ann. +1884 Walsingham, Lord, F.R.S , Merton Hull, Thetford £20 1 890 Waterliouse, Edwin, 44, Gresham Street, E.G. ann. 1 890 Were, Nicholas, 9, Osborne Place, Plymouth ann. 1895 Wickliani, Rev. T. D. C, Horsington Rectory, Templecomhe, Somerset ... ann. 1891 Wildy, A. G., \2, FurnivaVs Inn,E.G ann. 1884 Wilson, Scotl B., Heather Bank, Weyhridge Heath G. 1884 Woodall, John W., M.A., F.G.S., St. Nicholas House, Scarborough ann. 1891 Young, Sydney, M.D., 13, Aberdeen Terrace, White Ladies Road, Bristol, ann. IV.— Associate Members. 1889 Ahvard, George, 11, Hainton Street, Great Grimsby. 1889 Caux, J. W. de. Great Yarmouth. 1889 Dannevig, Capt. G. M., Arendal, Norway. 1889 Dunn, Matthias, Mcvagissey. 1889 Olsen, 0. T., F.L.S., F.R.G.S., Fish Dock Road, Great Grimsby. 1889 Ridge, B. J., 3, Gainsbord Place, Mxitley, Plyiaouth. 1890 Roach, W., 4, Gascoyne Place, Plymouth. 1889 Shrubsole, W. H., 62, High Street, Sheerness-on-Sea. 1889 Sinel, Joseph, 2, Peel Villas, Cleveland Road, Jersey. 1890 Spencer, R. L., L. and N. W. Depot, Guernsey. 1890 Wells, W., The Aquarium, Brighton. 1890 Wiseman, Fred., Buckland House, Paglesham., Rochford, Essex. OBJECTS OF THE glai'ine lioloiiical Association of tijc 'JlnitA llingbom. THE ASSOCIATION was founded at a Meeting called for the purpose in March, 1884, and held in the Rooms of the Royal Society of London. The late Professor Huxley, at that time President of the Royal Society, took the chair, and amongst the speakers in support of the project were the Duke of Argyll, Sir Lyon Playfaie, Sir John Lubbock, Sir Joseph Hookek, the late Dr. Carpenter, Dr. GtJNTHER, the late Lord Dalhousie, the late Professor Moseley, the late Mr. Romanes, and Professor Lankester. The Association owes its existence and its present satisfactory condition to a combina- tion of scientific naturalists, and of gentlemen who, from philanthropic or practical reasons, are specially interested in the great sea fisheries of the United Kingdom. It is universally admitted that our knowledge of the habits and conditions of life of sea fishes is very small, and insufficient to enable either the practical fisherman or the Legislature to take measures calculated to ensure to the country the greatest return from the ''harvest of the sea." Naturalists are, on the other hand, anxious to push further our knowledge of marine life and its conditions. Hence, the Association has erected at Plymouth a thoroughly efficient Laboratory, where naturalists may study the history of marine animals and plants in general, and where, in particular, researches on food fishes and molluscs may be carried out with the best appliances. The Laboratory and its fittings were completed in June, 1888, at a cost of some £12,000. Since that time investigations, practical and scientific, have been constantly pursued at Plymouth. Practical investigations upon matters connected with sea-fishing are carried on under the direction of the Council ; in addition, naturalists from England and from abroad have come to the Laboratory, to carry on their own independent researches, and have made valuable additions to zoological and botanical science, at the expense of a small rent, for the use of a working table in the Laboratory, and other appliances. The number of naturalists who can be employed by the Association in special investigations on fishery questions, and definitely retained for the purpose of carrying on those researches throughout the year, must depend on the funds subscribed by private individuals and public bodies for the purpose. The first charges on the revenue of the Association are the working of the sea- water circulation in the tanks, stocking the tanks with fish and feeding the latter, the payment of servants and fishermen, the hire and maintenance of fishing boats, and the salary of the Resident Director and Staff. At the commencement of this number will be found the names of the gentlemen on the staff. In no case does any one salary exceed £2.50. The Association has received some £25,000, of which £11,000 has been granted by the Treasury. The annual revenue which can be at present counted on is about £1,820, of which £1,000 a year is granted by the Treasury, the remainder being principally made up in Subscriptions. The admirable Marine Biological Laboratory at Naples, founded and directed by Dr. Dohrn, has cost about £20,000, including steam launches, &c., whilst it has an annual budget of £7,000. The purpose of the Association is to aid at the same time both science and industry. It is national in character and constitution, and its affairs are conducted by a representative Council, by an Honorary Secretary and an Honorary Treasurer, without any charge upon its funds, so that the whole of the subscriptions and donations received are devoted absolutely to the support of the Laboratory and the prosecution of researches by aid of its appliances. The reader is referred to page 4 of the Cover for information as to membership of the Association. CONTENTS OF NEW SERIES, Vol. IV., No. 3. I'A(iE 1. Contributions to Marine Bionomics. I. The Habits and Respi- ratory Mechanism of Corystes Cassivelaunus. By Walter Garstang, M.A. . . . . ... 223 •2. Physical and Biological Conditions in the North Sea. By J. T. Cunningham, M.A. . . . ... 233 3. Xote on a Specimen op Echinorhinus spinosus. By F. B. Stead, B.A. 264 4. How DO Starfishes open Oysters? By Dr. Paulus Schiemenz (Translated from the German by E. J. Allen) . ... 206 5. Algological Notes. By George Brebner . ... 286 6. Supplement to Report on the Sponge Fishery of Florida, and THE Artificial Culture of Sponges. By E. J. Allen, B.Sc. . 289 7. Variations and Relationships of the Flounder and the Plaice. By F. B. Stead, B.A. . . . ... 293 8. Director's Report . . . . ... .300 9. Report of Council, 1895-96 . . . ... 302 lu. List of Governors, Founders, and Members, IsL August, 1896 . 308 NOTICE. The Council of the Marine Biological Association wish it to he understood that they do not accept resi^onsibility for statements publi-shed in this Journal, excepting when those statements are contained in an olHcial report of the Council. TERMS OF MEMBERSHIP. Annual Members .... per aiiuuni. 1 1 U Life Members . . . Composition Fee. 15 15 0 Founders . . . ... 100 0 0 Governors . . . ... 500 0 0 Members of the Association have the folloM'ing rights and privileges ; they elect annually the Officers and Council ; they receive the .Journal of the Association free l)y post ; they are admitted to view the Laboratory at Plymouth, and may introduce friends with them ; they have the first claim to rent a jilace in the Laboratory for research, with use of tanks, boats, &c., and have access to the books in the Library at Plymouth. All corres])ondence .should be addressed to the Director, '11 le Laltoratory, IMvmouth. New Series.— Vol, IV., No. 4— issued March, 1897.] [Price 3s. 6d. 3(ountaI -r; ,.,. 1897 ^-lij OF THE MARINE BIOLOGICAL ASSOCIATION /^/;^ OF THE UNITED KINGDOM. THE PLYMOUTH LABORATORY. J-. PLYMOUTH: PRINTED FOR THE MARINE BIOLOGICAL ASSOCIATION BY W. BRENDON & SON, AND PUBLISHED BY THE ASSOCIATION AT ITS OFFICES ON THE CITADEL HILL. SENT FREK BY POST TO ALL MEMHEKF OF THE MARINE BIOLOGICAL ASSOCIATION: ANNUAL SUBSCRIPTION FOi; MF»'"ERSHIP, ONE GUINEA. Agents in London :— Messrs. Dulau & Co., 37, Soho Square, W. PATRON. II.R.H. THE PRINCE OF WALES, K.(;., F.R.S. OFFICERS AND COUNCIL. President. Prof. E. Ray Lankester, LL.D., F.R.S. Vice-Presidmts. The Duke of Ahgyli., K.G., K.T., F.R.S. The Duke of Abercorn, K.(j., C.B. Tlie Earl of St. (Germans. Tlie Earl of MoRLEY. Tlu^, Eiivl of DuciE, F.R.S. Lord Revelstoke. The Right Hon. Lord Tweedmol'th. Lord Walsingham, F.R.S. The Right Hon. A. J. Balfour, M.P., F.R.S. Tlu' Right Hon. Joseph Chamber- lain, M.P. The Right Hon. Sir John Lubijook, Bart., M.P., F.R.S. Prof. G. J. Alljian, F.R.S. Sir Edward Birkbeck, Bart. Sir WiL Flower, K.C.B., F.R.S. Dr. A. C. L. GuxTHER, F.R S. Prof. Alfred Newton, F.R.S. Rev. Canon Norman, D.C.L., F.R S. Sir Henry Thompson. Rear-Admiral Wharton, C.B., F.R.S. COUNCIL. Elected Members. F. E. Beddard, Esq., F.R.S. Prof. F. Jeffrey Bell, F.Z.S. G. C. Bourne, E^i, F.L.S. Sir John Evans?, K.C.B., IXC.L., Treas. R.S. G. Herbert Fowler, Esh{, F.R.S. D. H. Scott, Esq., F.R.S. P. L. Sclater, Es1. Soc.) Prof. Charles Stewart, F.R.S. Prof. W. F. R. Weldon, F.R.S. Governors. Robert Bayly, E.sq. I Prof. Burdon Sanderson, F.R.S. J. P. Thomasson, Esq. (Oxford University). Tlie Prime Warden of xhk I-'ish- I'lof. Michael Foster, VM.':^. ('ani- mongers' Company bridge University). E. L. Bhckwith, Es(j. (Fishniongt-rs' Sir \Vm. Flowkh, K.C.B. F.l! S. (P.rit. Coiii])any) Assoc. for Advam-cuu'iit ofSiiriice). JIoii. Treasurer. K. Ij. BecKWITH, Es(j., The Knoll, Eastliournc. PERMANENT STAFF. Director and Hon. Sec.—E. J. Allen, Esq , B.Sc, Tlie Lal>oratory, Citadil Hill, Plvniouth. Assistant to the Director — T. V. Hodgson, Esq. APR 22 1897 ^ 3^. ^ On the Peculiarities of Plaice from Different Fishing Grounds. By J. T, Cunningham, M.A. The investigation here described may be regarded as the natural sequel of the observations by which I showed that the plaice of the Brown Eidges, as well as those from the Plymouth grounds, were smaller when they attained to sexual maturity than those of the northern part of the North Sea. Mr, Holt, in 1894, published in this Journal some obser- vations on the dwarfed and ciliated or spinulated plaice of the Baltic ; and Dr. Heincke, now Director of the German Biological Station at Heligoland, had suggested as a probability that the plaice of the Heligoland region were a smaller geographical race, distinguishable by special characters from those of other regions. I referred to this subject at the end of my paper on the Physical and Biological Con- ditions in the North Sea, in the preceding number of this Journal, and mentioned the paper in which Georg Duncker* has recorded and discussed the results of an examination of samples of plaice and flounder from various localities. Among these localities was the Heligoland region; but Duncker had not compared the plaice of Heligoland with those of other parts of the North Sea. I have not had time to make as extensive an investigation of the matter as would be desirable. I commenced my observations at Lowestoft in September last, and continued them until tlie beginning of December, when I quitted the service of the Marine Biological Association. I have examined samples of plaice from the Brown Eidges, from the grounds off the Norfolk coast, from a position north-east of the Dogger Bank, and from the neighbourhood of the Eddystoue Lighthouse. I have also endeavoured to acquaint myself with the complete geographical dis- tribution of the plaice and the species most nearly allied to it, and for this purpose devoted several days to the examination of specimens in the National Collection. I have to thank Mr. G. A. Boulenger, F.E.S., * JFiss Mccrcsimtersuch. , Neue Folgo, Bd. I., Hoft. 2, 1896. NEW SERIES.— VOL. IV. NO. 4. Z 316 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. for his kindness and courtesy in providing me with facilities for carrying out this part of the work in the Natural History Museum at South Kensington. I will describe first the characters of the samples of plaice from the North Sea and the South-west coast. I. The Variations Observed in Plaice from different parts of THE North Sea and Channel. The method I have employed is not exactly the same as that adopted by Duncker, who followed the example set by Heincke in his papers on the varieties of herrings, in the publications of the Commission zur Untersuchung der Deutschen Meere. The first step in either method is the actual observation by measurement and counting of the principal characters in eoch individual fish. The characters selected by Duncker were the following : — 1. The number of vertebrae in the caudal peduncle. 2. The number of vertebra} between the abdomen and the caudal peduncle. 3. The number of abdominal vertebra?. 4. The total number of vertebrae. 5. The number of gill-rakers on the first branchial arch. 6. The number of dorsal fin-rays. 7. The number of ventral fin-rays. 8. The length of the caudal peduncle. 9. The mean height of the same. 10. The greatest height of the body without the marginal, or dorsal and ventral, fins. 11. The greatest length of the head, on the upper side. 12. The extent of spinulation in the males. In accordance with Heincke's method Duncker divided the variations observed in each of these characters into stages, which he denoted by symbols. The object of this is, firstly, to eliminate small errors of observation; secondly, to allow the differences to become more distinct; and thirdly, to show the relations between different variations ; that is, to exhibit what is known as correlation. The character of each fish is thus represented by a formula consisting of a number of symbols, and a difference between local races may be demonstrated by the fact that the most frequent formulas are different in the two cases. I decided to neglect the examination of the number of vertebra? altogether. The variations in these were too small to be likely to exhibit any differences between the different samples I was investigating, and so far as they existed would be sufliciontly represented by the variations in the number of fin-rays and length of the caudal peduncle. PECULIARITIES OF PLA.ICE FROM DIFFERENT FISHING GROUNDS. 3l7 The exposure and enumeration of the vertebrre are operations that take some time, and by omitting them I was able to examine a larger number of specimens. I omitted also the mean height of the caudal peduncle, the determination of which did not appear to be susceptible of great accuracy, and I did not follow Duncker in combining together head-length and height of body. 1 added the examination of another character, namely, the number of the tubercles, whose prominence or flatness I also noted. The characters I have examined are therefore the following ; — 1. Maximum height of body without fins. 2. The length of the head, from the apex of the lower jaw to the end of the opercular bone, on the upper side. 3. The length of the caudal peduncle, from a line joining the ends of the marginal fins to the middle of the line of articulation of the caudal fin-rays. 4. The length of the caudal fin, from the latter point to the end of the middle rays. 5. The number of the tubercles on the head behind the eyes. 6. The number of the gill-rakers on the first branchial arch, upper side. 7. The number of the dorsal rays. 8. The number of the ventral rays. 9. The number of ciliated rays in the dorsal and ventral fins. 10. The ciliated (spinulated) scales on the head and body. 11. The maturity or immaturity of each specimen. The measurements of lengths were made with a millimetre scale and a pair of dividers, and they were only taken to the nearest millimetre. It did not appear that greater accuracy was possible. The body of a plaice is not rigid like that of a crustacean, but any part of it may be stretched or compressed a fraction of a millimetre, so that any greater accuracy of measurement would have been apparent and not real. No such qualification applies to the enumerations of numerical characters, which are absolute, and were made with the greatest care. The lengths of parts after measurement were calculated as hundredths of the total body-length, which was measured from the apex of the lower jaw to the end of the tail. To obtain this length the fish was laid upon the measuring-rod, and the lower jaw was pushed into contact with the vertical surface of a piece of wood placed upright at one of the lines of the measure, the length at the end of the tail being then read off directly. The measure was always taken with the lower jaw just closed and not pressed. As the lengths were only taken to millimetres it seemed useless to calculate the proportions to higher fractions than hundredths of the body-length. The fish varied from about 200 to 318 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 500 mm. in length, so that -01 of the total length varied from 2 mm. to 5 mm., but -001 would have implied accuracy to from -2 to '5 mm., which was greater than the accuracy of direct measurement. (Con- sidering the great variations in the proportions with age and condition of the individual, differences between local races not exhibited in hundredths of the total length may be regarded as quite unimportant. The direct results of the examination of the specimens and calcula- tion of percentages are recorded in Tables A appended to this paper. The sexes are recorded separately, and the specimens given in order of total length, in order to show what variations depend upon sex or increase in size. The comparison between the samples from different localities, in Tables B, has been made by placing side by side the actual numbers of individuals observed to have each degree of variation which was distinguished. Duncker has given tables of frequency, but they differ from mine in two respects; firstly, that he takes the larger stages of variation mentioned above, and secondly, that he has given the i^er- centafje of individuals, not the actual number. As the number of individuals was in my investigation rather small, and as the object was only to ascertain and compare the distribution of the variations, no advantage appeared to be gained by comparing the percentages of individuals instead of the actual numbers. The largest number of individuals have been examined in the case of the Brown Eidges and the Norfolk coast, these being the two principal distinct regions where the sailing trawlers of Lowestoft work. From the other two regions, namely, the Eddystone grounds and the ground to the north-east of the Dogger Bank, a smaller number were obtained. All those from the Brown Bidges were examined at Lowestoft, and also the greater number of those from off the Norfolk coast: the latter include samples taken outside the Dowsing Bank, off Cromer, and off the Well Bank. An additional sample, taken fourteen miles from Cromer, was sent to me in London from Lowestoft, The Plymouth samples were sent from the Plymouth Laboratory. The remaining sample was a box sent from Billingsgate, and stated by the sender to have been caught 220 miles from Smith's Knoll, just to the north of the tail of the Dogger Bank, at a depth of 25 fathoms. I will proceed now to the comparison of the various characters in the samples. According to the statistical enquiries of Mr. Francis Galton and Professor Weldon the magnitude of a character which occurs with the greatest frequency nearly coincides with the arithmetical mean of all the observed magnitudes, and the frequencies of the other magnitudes are symmetrically disposed about the maximum frequency. tECULIAKITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 319 111 my results in the majority of cases an approximation to this condition is visible; but I have not calculated the actual mean, or attempted to determine the probable error or mean error of the deviations. The question I have proposed to investigate is merely whether there are between the samples differences in the characters examined, which are sullicient to be definitely demonstrated by comparing the frequencies with which the variations occur. The most frequent height of body in the plaice of Brown Ridges is 39, both in the males and females. In the females from the Norfolk coast it is the same, while in the males it is 38. But we cannot say therefore that the Norfolk males are narrower, for among the Brown Eidges specimens there are 16 having a body-height less than 38 per cent., and among the Norfolk coast males only 10. On the contrary, the number of specimens having heights of 4Q, 41, and 42, is greater in the Norfolk coast males than in those of the Brown Ridges, and this does not appear to be due to a difference of age or stage of growth. Duncker found that a considerable decrease in breadth took place between 15 cm. and 20 cm. in length, and an increase after 30 cm. But where two local races are known to differ in absolute size, like those "\ve are now comparing, the question is whether we are comparing samples of corresponding stages and ages. Now there are rather more specimens between 20 cm. and 25 cm. in the Norfolk coast sample than in the other, and therefore more young specimens, and these should be rather narrower than the old specimens ; but we have no reason to suppose that the largest specimens in the Norfolk coast sample are older than those from the Brown Ridges. On the whole, then, we must conclude that the male plaice from the Norfolk coast are broader than those from the Brown Ridges. The single male at 45 was only 20*7 cm. long. The females of the Norfolk coast are also slightly broader than those from the Brown Ridges. It will be seen that the difference between the sexes in height of body is very slight, but what superiority there is, is on the side of the females, and this is in agreement with Duncker's results. In the Plymouth females the body-height 38 per cent, is the most frequent, while the males appear to be broader, the maxi- mum being at 39. On the other hand, in the plaice from north of the Dogger Bank, although there is no maximum frequency, the number of individuals being small, the much greater breadth of body is suOiciently obvious. A comparison of the lists of specimens from, the Norfolk coast, and from the more northern ground which 1 have given, will show that the greater breadth of the more 320 PECULIAKITIES OF PLAICE t"llOM DIFFEEENT FISHING GROUNDS. northern specimens does not depend entirely on age or size. A similar great height of body was found by Duncker in the Cattegat plaice, which exceed in this respect the plaice of the Baltic. The latter are stated to be mostly from 38 to 39 per cent, in height, like my specimens from Brown Ridges and the Norfolk coast. Now the largest specimens from the Cattegat examined by Duncker were between 39 and 40 cm. in total length ; but Petersen, in the Report of the Danish Biological Station, 1893, records specimens up to nearly 22 inches, or 55 cm. Thus the Cattegat plaice do not appear to be very much smaller on the whole than those of the northern part of the North Sea, and we may conclude that they are similar to these. Whether they agree with them in other characters will be seen in the course of this paper. In the last two columns I have added the figures of Plymouth and Brown Ridges to represent a southern race, and the figures of the other two localities to represent a northern, and it will be seen that though the maximum frequency still remains in both sexes of both races at 39, yet the northern race is distinctly broader. In the second set of tables are seen the frequencies obtained by taking all individuals regardless of sex, and here also the greater breadth of the Norfolk coast specimens, and of those from north-east of the Dogger Bank, is evident. Length of Head. The most conspicuous fact that appears from the figures referring to this character is that in all four cases the females are distinctly longer in the head than the males. This agrees with Duncker's results. Duncker also found that the length of the head decreased during the growth of the fish. Such decrease is evident in my list of the males from the Brown Ridges, where the length 20 occurs seven times among the 15 largest specimens, and only greater lengths occur among the 37 smaller. The length 19 per cent, occurs only once, and that is in the largest male from beyond the Dogger Bank. But a sinular decrease is not perceptible in the females. In the Norfolk coast females the length 24 per cent, occurs eight times, twice in the largest specimens, three times in specimens between 30 and 40 cm., and three times in specimens between 20 cm. and 30 cm. The greater length of head, then, in the females of the Norfolk coast is not due to a greater proportion of young specimens in this sample. In the samples from the Brown Ridges and the Norfolk coast the maximum frequency is in both sexes at 22, but in the case of the Norfolk coast the greater lengths are more frequent, and the shorter less frequent than in the case of the Brown Ridges. It is not, however, so obvious that the specimens from north-east of the Dogger Bank have longer heads than those of the Norfolk coast, or even than those PECQLIAKITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 321 of the Brown Eidges. If we take into consideration the small number of specimens we see that there is a slight superiority over the latter. The Plymouth specimens again, as far as we can judge from so small a sample, appear to be a little shorter in the head than those of the Brown llidges; in the males of these only the most frequent head- length is 21, while in all the other cases the maximum is at 22. In treating the samples in two sections only, southern and northern, we see that the former are shorter in the head. When the numbers of the two sexes are combined, the Norfolk coast sample appears to have the longest head on account of the large number of females in this sample. The greater length of head in the northern plaice is evident when all the figures are combined into two columns. Caudal Peduncle. In this character a constant difference between the sexes is not evident, but again a slight superiority in the northern samples is indicated. Length of Caudal Fin. The caudal fin appears to be distinctly longer in the sample from the Norfolk coast than in that from the Brown llidges, the most frequent length being 19 per cent, in the former, 18 per cent, in the latter. The Plymouth specimens, however, have rather longer tails, at least in the males, than those of the Brown Eidges, and those of the north-east of the Dogger Bank rather shorter than those of the Norfolk coast. I am inclined to think that a reduction in the relative length of the caudal fin takes place as the limit of increase in size is reached ; in other words, that the fin is shortest in the oldest specimens, the caudal fin growing less than the body in adult specimens, especially when the size reached is great. Thus two of the three specimens of the Norfolk coast, in which the caudal fin is only 16 per cent, of the total length, are the two largest, 568 cm. and 63-0 cm. respectively. The Norfolk coast samples certainly include more young specimens than any of the others, as well as absolutely the smallest specimens examined, as is natural from the fact that the district is nearest to the shore ; and in this sample the greater lengths of caudal fin are most frequent. Number of Tubercles. This is a character which is not considered by Duncker. Numerical characters are not usually subject to change with growth in the individual, but this character may possibly change to some extent. When one or more tubercles are so fiat as to be virtually obsolete, I have counted only those which were distinct, while in other cases some of the five usually present are represented by two or more separate points. The flatness or prominence of the tubercles must be considered, and it is not fully represented in the tables. In all cases the normal number 5 is most frequent. A reduction occurs most commonly in the sample from the Norfolk coast ; it does '6'12 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. not occur in the specimens from the Brown Eidges, but is more common in the Plymouth specimens than in those from north-east of the Dogger Bank. The description " flat," however, in reference to the tubercles, occurs frequently among the notes of examination of the specimens from beyond the Dogger Bank, and least frequently in connection with the Brown Eidges specimens. The reduction of the tubercles, which makes some of them virtually obsolete and the rest less prominent, was particularly noticed in the largest females from the Norfolk coast, especially in a sample sent me in November, and caught fourteen miles off Cromer. In many of these I thought the condition suggested that the tubercles had actually been subject to mechanical friction. In the same specimens the edges of the marginal fins were thickened and contracted, evidently in consequence of frequent abrasion and healing. We know that the ground off the Norfolk coast is very rough and stony, and that the plaice is in the habit of burying itself in the ground it lives on. The fish also must doubtless push its head under stones and into the ground to obtain its prey ; so that I think it very probable that the tubercles, as well as the edges of the fins, are worn away in the plaice of this district. The ground on the Brown Eidges, on the other hand, is composed of exceedingly fine smooth sand ; that beyond the Dogger Bank is rather smooth ; and on the Plymouth grounds both rough and smooth occur. Gill-rakers. In all cases the most frequent number of the anterior processes on the first branchial arch is 10, and there is not much difference in this character between the sexes or the samples from different localities. But there is seen in the females of the Norfolk coast a slight indication of an increase in the number; the numbers above 10 occur more frequently in proportion. Considering the large number of female specimens from the locality which were examined (91), this result is, I think, significant, and it is confirmed by a similar indication in the females of the most northern locality. We may infer that the number of gill-rakers increases as we proceed towards the north. Fin-rays. The variation in the number of fin-rays is considerable, and the frequencies of the different variations are not very symmet- rically distributed. The largest sample is that of the females of the Norfolk coast, and here the most frequent number in the dorsal fin is 72 ; but the middle frequency, which is almost as great, is 73. The most frequent number in the males is 74; but, nevertheless, it will be seen that on the whole the number of fin-rays is greater in the females than in the males in all the samples; that is to say, in tlie former the higher numbers occur more frequently, and the lower PECULIARITIES OF PLAICE FliOM DIFFERENT FISIHISG GROUNDS. 323 numbers less frequently. In the females from the Brown Piidges there are two maxima for the dorsal rays : one at 70, the other at 76. Whether this indicates a true dimorphism, like that found by Professor Weldon in the shore crabs of Naples with regard to their frontal breadth, I am not prepared to say, the number of individuals being too small. But it is clear that the females of the Brown Eidges have on the whole a slightly greater number of fin-rays than those of the Norfolk coast, and the same is true of the males. As in other cases, the Plymouth specimens seem to resemble those of the Brown Ptidges ; those from beyond the Dogger Bank to resemble those of the Norfolk coast, in this character. The most frequent number of anal rays in the Norfolk coast and Brown Pidges samples is 55, except in the males of the former, where it is 53 or 54. As in the case of the dorsal rays, the figures show a slight superiority in number of anal rays of the southern samples over the northern, although the difference is not in either case very important. Spinidation of the Scales, or Ciliation. In the tables of frequencies I have employed almost the same degrees of spinulation as Duncker, but have distinguished two degrees in the spinulation of the head instead of one. The degrees are (1) on the middle rays of the dorsal and ventral fins only ; (2) also on the head in front of the preopercular bone ; (3) also on the operculum ; (4) also on the skin of the body near the edges, in the region over the interspinous bones ; (5) spinulation extended over other areas of the body. In examining the speci- mens I counted and recorded the number of dorsal and anal fin-rays on which spiuulated scales occurred, and in the first set of tables in which the characters of each specimen are given I have added the numbers together, and given for each specimen the total number of spiuulated rays. One object of this was to ascertain whether the spinulation of the scales extended on to additional rays in proportion to the degree in which it extended to other parts of the body. The result is to show that there is no exact proportion between the number of fin- rays which are spinulated and the extension of the character on other parts of the body. The fact is that scales are also present along the middle rays of the dorsal and anal fins in the females and in the young males, although, like the scales on the other parts of the body, in these cases they are not furnished with spines on their outer edges. In a female 307 cm. long from Plymouth I found that there were rudimentary scales on 24 of the dorsal rays and 21 of the ventral. The spinulation develops at about the time when the male becomes mature, and evidently develops very quickly, although it possibly increases with age. I obtained some male specimens of the Norfolk coast plaice from 20 cm. to 25 cm. in length on purpose to 324 PEUULIAKITIES OF PLAICE fllOM DIFFERENT FISHING GliOUNDS. study the developmeut of the spiuulatiou on the scales. In a specimen 207 cm. long, and another of 238 cm., there was no trace of spines on the scales of the fin-rays, while in another 25"8 cm. long they were just developing. In most cases there are not more than two spines on each scale, and on many scales only one spine. The spine commences as a deposit of calcareous matter in the shape of a short cone, and is formed not as an outgrowth from the scale, but as a separate deposit, of which the base afterwards becomes united to the scale. The position and shape of the growing spine are shown in Fig. 1. In the table of the frequencies of the degrees of spinulation I have omitted those specimens from the males of Norfolk coast and the Brown liidges which were below 26 cm. in length. In the former case there were eight of these, leaving 41 to be considered; in the latter there were only two omitted, leaving 50. It will be seen that in both cases the second degree of spinulation is the most frequent, but it is equally evident Fig. 1. Scale of dorsal fin-ray of a plaice from the Norfolk coast, 25 "8 cm. long, magnified. S the incipient spine at the outer edge of the scale. that the higher degrees are somewhat more frequent in the specimens from the Norfolk coast. Now among the latter the smaller specimens must be younger and more immature than those of the same size from the Brown liidges, and therefore the lower degrees of spinulation ought to be more frequent in the specimens from the Norfolk coast, if we consider only those which do not exceed the maximum length of those from the Brown liidges. One specimen, however, of the three from the Norfolk coast which had no spinulation was actually mature — it was 36"5 cm. long ; the other two were apparently immature, and were smaller. This shows that the development of spinulation does not always correspond exactly to the attainment of maturity, although it does so usually. In the Norfolk coast sample there are 12 specimens exceeding in size the largest of the Brown liidges plaice ; the largest of these 12 is 48'9 cm. long, the next largest is 43*2 cm. Putting aside the largest, we cannot consider the other 11 to be older than any of the tECULIAlailES 01* PLAICE FHOM Dlt'fERENT I'ISIIING GliOUNUS. 325 specimens from the Brown Eidges, because the difference is not greater than that which I have shown to exist in the length of the smallest mature in the two cases. The largest specimen from the Norfolk coast has the fourth degree of spinulation. Taking all these facts into con- sideration, I conclude that on the whole the spinulation is slightly but distinctly greater in the plaice from the Norfolk coast than in those from the Brown Bidges. In the females also there is a slightly more frequent spinulation among the specimens from the Norfolk coast than in those from the Brown Badges. It is rare to find any trace of the condition in the females, but it is by no means exclusively confined to the oldest or largest specimens. One of the three spiuulated females from the Norfolk coast was only 27"0 cm. long, and apparently immature. The much greater development of spinulation in the plaice from beyond the Dogger Bank is very evident from the figures. But we must consider how far this may be due to the greater age of the specimens, since the locality where they were captured is in greater depth of water and much farther from the coast than the district off the Norfolk coast, or even the Brown Ridges. Now in the males of the deep-water sample there are eight specimens over 40 cm. in length, the largest being 47*3 cm. long ; of these, in the smallest specimen, the degree of spinulation is 2, in the largest 5, and in the other six 4. Of the males from the Norfolk coast, six are over 40 cm. in length, and the largest is 48-9 cm. long ; of these three have degree 2, one degree 3, and two only have degree 4. We have no reason to suppose that the northern specimens are older, although not larger; the presumption is the contrary. Therefore we have suflicient proof that the plaice from the more northern locality are considerably more spinulated at the same age than the Norfolk coast specimens, and a fortiori than those of the Brown Bidges. There is evidence that the development of spinulation increases with age; but enough evidence has been here produced to show that the difference between my samples from different localities is not due to differences of age. It may be pointed out as worthy of note that in the two females in which spinulation occurs among the specimens from beyond the Dogger Bank, it is present on the cheek, and almost entirely absent from the fins. The males from Plymouth appear to be rather more spinulated than those from the Brown Bidges ; but it may be mentioned that in the specimen which is recorded as having degree 4, the spinulation of the interspinous regions was only just perceptible. RccaintuUdion. Tiie investigation shows that although the number of individuals examined is not so large as it ahould be, yet there are 82(3 PECULIARITIES OF PLAICE FPvOM DIFFERENT FISHIISG GROUNDS. distinct diflerences in structural characters between the samples, especially between those of the Norfolk coast and the Brown Kidges, which would almost certainly be confirmed by examination of a larger number of specimens. Omitting the tubercles and the length of the caudal peduncle, in which the indications are not very distinct, I find distinct differences in the following characters : Height of body, length of head, length of caudal fin, spinulation of scales, number of gill-rakers, number of fin- rays. The length of the caudal fin decreases apparently with age, and it is not very evident that it is a permanent characteristic of the different local forms. We have then left three characters of proportion and two of number. The first three characters all vary with age, the latter two do not change in the individual. The change in the height of the body with age does not appear to be very constant or important in my samples ; the height is distinctly greater in the northern samples than in the southern. The difference between the sexes is slight. The length of head is a marked sexual character, being greater in the females ; it decreases as age advances, but within the limits of size of my specimens the decrease is not obvious in the females, and not very important in the males. The length of head is a little greater in the northern samples. The spinulation of the scales is a character, with few exceptions, confined to mature males, and forms the most conspicuous local peculiarity. There is no important difference in this character between the plaice of Tlymouth and those of the Brown Eidges; but on the Norfolk coast, and still more beyond the Dogger Bank, it is much more developed than on the Brown Ridges. The number of fin-rays is slightly greater in the females, and is somewhat less in the northern samples than in the southern. The gill-rakers, on the contrary, are slightly increased in the northern samples as compared with the southern. II. Comparison of the Local Forms Examined with those OF other li eg ions. Duncker examined 35 males and 45 females caught in the neigh- bourhood of Heligoland. The males were from 13-4 cm. to 289 cm. in length, the females from 19-3 cm. to 32-6 cm. Now I have shown in a previous paper that no plaice from this district were mature below 11 in., or very nearly 28 cm., in two samples which I examined, con- taining together 307 specimens. It is not surprising, therefore, that in Duncker's specimens the degree of spinulation was much lower than PECULIARITIES OF PLA.ICE FROM DIFFERENT FISHING GROUNDS. 327 in the samples described above from the Norfolk coast, and even from the Brown lUdges. Duncker's male specimens from Heligoland must have been all, or nearly all, immature. It will be seen from my list of Norfolk coast specimens that spinulation often commences on the fin-rays before maturity, and this accounts for the fact that the first stage of the character occurs in a considerable proportion of Duncker's specimens. The smallest in which it occurs is 20'6 cm. long ; the largest in which there is no spinulation at all is 2G"6 cm. long. In my Norfolk coast samples the smallest specimen in which spinulation occurs is 23'5 cm. long, and only one smaller than this was examined, while the largest in which it was absent is 36"5 cm. long. Degree 2 occurs in Duncker's specimens, in one specimen 24o cm. long, and one 267 cm. long, while in the Norfolk coast specimens the smallest in which this degree occurs is 27"3 cm. long. It is not possible then to conclude from Duncker's specimens whether in the race to which they belong spinulation is much developed or little. There is nothing to contradict the probability that they belong to a race as strongly spinulated in the adult males as the Norfolk coast form or that from beyond the Dogger, and we certainly have no evidence at present that they are less spinulated than those of the Brown Ridges. Duncker unfortunately overlooked the question of ■ the age and maturity of his samples, Duncker divides the height of the body into only two degrees, and combines it in his formulai with the length of the head, and I can therefore only attempt to make a comparison from his descriptive remarks. He says that the height exceeds 38 per cent, in the Heligoland plaice but seldom, and it would seem from this that these plaice are rather narrower than those from the Norfolk coast of the same size, and perhaps than those of the Brown Ridges ; but the comparison, under the circumstances, is not worth much. Seventy-two per cent, of the Heligoland specimens have a length of head over 24 per cent., and this would seem to show that these plaice were much longer in the head than any of my North Sea samples. But with regard to both these characters it must be remembered that the pro- portion of smaller specimens is much higher than in my samples, even when I consider only those of my specimens which are below the maxima sizes of Duncker's; and I conclude, therefore, that the head is much longer in the younger specimens. Indeed Duncker himself mentions the fact, stating that the 21 smaller females from Heligoland have a mean head-length of 24"9 per cent., and the 24 larger, above 23'G cm. in length, a mean of only 23'7 per cent. No comparison then is possible except in the characters which do not vary with age, namely, the numbers of fin-rays and gill rakers ; 328 PECULIAltlTIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. and liere Duncker does not give details, but simply states that the anal rays are mostly 51 to 55, the dorsal 66 to 80, aud the gill-rakers mostly 10 or 11. In describing some specimens from the Baltic in this Journal* Mr. Holt referred to two spinulated specimens of the plaice, one from the south coast of Iceland, and one from the Great Fisher Bank in the North Sea. These specimens were among the collections left by Mr. Holt at Cleethorpes which came under my charge. I have examined them, and recorded their characters in the tabular lists appended to this paper. They are both males of large size, and except in the greater size of the Iceland specimen do not differ much from the largest of the males I have examined from beyond the Dogger Bank. In both specimen'', as often occurs in the higher degrees of spinulation, this character is developed slightly on the head and body on the lower side. It never occurs on the fin-rays of the lower side, because there the scales are virtually obsolete. In the Iceland specimen the scales are spinulated all over the upper side of the body except below the pectoral fin, and also very slightly on the head and interspinous regions on the lower side. In the Fisher Bank specimen the spinulation extends all over both sides, also with the same exception, but is much weaker on the lower side than on the upper. We have next to consider the plaice of the IJaltic, samples of which are described by Duncker. Some of the specimens mentioned by Holt in the paper above cited came into my hands, and their characters are detailed in the tabular lists. The plaice of the Cattegat occupy geographically a somewhat intermediate position, and we may examine their characteristics before referring to the fish of the Baltic proper. Duncker remarks of the Cattegat plaice that they resemble those of Heligoland in all other respects, but differ in their enormous height of body and the shortness of the head. This is exactly what might be expected when we know that Duncker's sample from Heligoland consisted chiefly of very young and small specimens of a large-sized race. The males of Duncker's Cattegat sample were from 29"5 to 39-4 cm. in total length, and 10 in number; of females there were 30 specimens 28*0 to 38"G cm. in length. They were thus nearly all larger than the largest of the Heligoland specimens. Four of the 10 males had no spinulation, two had degree 2, and the rest degree 1. One of the specimens without spinulation was 39'4 cm. long, one 35"0 cm., one 341 cm., and one 29*5 cm. According to Petersen's recordst some male plaice are immature in the Cattegat at 32"o cm., if not even at a larger size. But in none of my samples is a male specimen so large as 394 cm. entirely without spinulation. I find it difficult to believe * Vol. iii. p. 198. + Report of the Danish Biological Station, iv. , for 1893. TECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 329 that plaice in the Cattegat are less spinulated when mature than those of the northern part of the North Sea, and think it probable that if a larger number of mature specimens from the former locality were examined they would be found to exhibit as great a development of spinulation. ]\Iy specimens from beyond the Dogger Lank, being taken in deep water far from land, would naturally include few immature specimens, and male specimens in that condition even 35 cm. in length might occur nearer shore. It must be pointed out that in my specimens from beyond the Dogger Bank degree 4 of spinulation only occurs in specimens over 40 cm. in length, and we know from Petersen that male specimens above that length occur in the Cattegat, although Duncker did not obtain any. There is nothing in the results of Duncker con- cerning the numerical characters to distinguish the Cattegat plaice from those of the northern part of the Xorth Sea examined by me. Duncker examined 34 males and 48 females from the Western Baltic, taken in the neighbourhood of Niendorf and Kiel. The males were from 22-6 to 29-7 cm. long, the females from 22-3 to 31-2 cm. long (from 9 in. to little over 12 in.). We know from Holt's evidence that plaice of the Western Baltic at these sizes are all, or nearly all, sexually mature. The spinulation varies from degrees 2 to 5 according to my notation, and it is certain that it is more strongly developed than in the most spinulated of my samples, degree 1 occurring not infreciuently in the females. The height of the body, on the average 38 to 39 per cent, according to Duncker, seems to be no greater than in the Norfolk coast plaice, and scarcely so great as in the specimens from beyond the Dogger Bank. The length of the head is a little greater than in the northern part of the North Sea. In the nurderical characters there is a marked reduction : the dorsal rays rarely exceed 70, though instances up to 75 and one of 78 occur. The ventral have a maximum of GO, but are mostly from 46 to 55. In this respect the form approximates to the character of the flounder. The number of tlic gill-rakers, however, is not greater than in North Sea plaice, but is on the contrary rather less, the number 12 not being exceeded, while in the Cattegat plaice the range of variation extends to 13, as in my specimens from the North Sea. The caudal peduncle, reaching sometimes 9 per cent., seems to be rather larger than in the North Sea. Duncker describes four males and seven females from Greifswald, a place on the coast opposite the island of lUigen, and little more than 100 miles east of Kiel. On the evidence of these few specimens he concludes that the Greifswald plaice ar6 on the whole different from those of the neighbourhood of Kiel, and approximate in several 330 TECULIARITIKS OF rL.VICE FItOM DIFFERENT FISHING CxROUNDS. characters more to those of the North Sea, although it might be expected that, the locality being farther inwards in the Baltic, they would be more different from the plaice of the North Sea. I fail, however, to find in Duncker's description any dilferences to which such importance can be attributed, especially when the small number of specimens is considered. The four males are all small and youn^, 19'6 to 22G cm., and this would partly account for the slightly lower height of body and greater length of head which Duncker mentions. The number of gill-rakers reaches 13, but I fail to see any difference in the number of fin-rays. The degree of ciliation was 2 in all four male specimens, which is in accordance with their small size. We see then that as far as the small amount of evidence at our disposal goes, the Baltic plaice are modified in the same direction as northern forms in the North Sea with regard to reduction of fin- rays and increase of spinulation, and to a much greater degree, wliile with regard to other characters, branchial rays, height of body and length of head, no very distinct differences are exhibited. In accordance witli the reduction of the dorsal and ventral fins, the caudal peduncle is a little longer in the Baltic. It is interesting to notice that as we proceed northwards in the North Sea and Atlantic these modifications are associated with a great increase in total size, while in the Baltic there is an equally conspicuous decrease in size. This proves that the modifications are independent of the rate of growth, and therefore presumably of the amount of available food. III. The Eelatioxs between Local Variations and Specific Characteus in the Plaice and Allied Species. The plaice and flounder are certainly very closely allied, and there is a third form which also differs but slightly from them. This third form is the Pleuronedes glacialis of Pallas. To study the relations of these three forms to one another we must take a general survey of all that is known concerning their whole distribution, and their variations in different parts of their habitats. The question has previously been discussed by Professor Smitt in his edition of the Scandinavian Fishes of Fries and Ekstnim, 1893, and by Duncker in the paper frequently cited above; but I have endeavoured, by examining additional evidence, to carry the investigation somewhat further. Pleuronedes platessa. Southwards on the European coast the plaice seems to extend into the Mediterranean, although I liave not been able to discover any very definite or detailed account of specimens from that sea. Smitt mentions its existence there, and Jordan and PECULIAKITIES OF PLAICE FROM DIFFEKENT FISHING GROUNDS. 331 Goss * state that in the Museum of Comparative Zoology at Cambridcre, Mass., there are a number of specimens from Trieste. Xorthwards the species extends to the White Sea. The evidence of this is that Smitt {loc. cit. p. 395) mentions a young plaice from Archangel which agrees with the form described by Pallas from Alaska and Kamtchatka under the name PL quad rituhcrculatus, and by Steindachner under the name PL Palhtsii. Smitt regards these names as synonyms of PL lAatessa. I do not admit the synonymy, and shall discuss the matter presently; but we may take it that the plaice extends to the White Sea. We have seen that it is abundant on the south coast of Iceland, and extends into the Baltic as far as Greifsvvald. But the plaice is not mentioned as occurring on the coast of Greenland, and is certainly absent from the east coast of North America. In the Pacific, however, forms which must be regarded as local varieties of the plaice, or very closely similar to it, reappear, and I will here give the history of these forms so far as it is known. The following is a list of the names under which the specimens have been described or mentioned : — Pkuroncctes quadrituhercidatus, Pallas, Zoogr. Rosso-Asiat. iii. 423, 1811. Bean, Proc. U.S. Nat. Mus. 1881. Jordan and Gilbert, Synopsis Fish. N.A. 1882. Parophrys quadrituherculatus, Glinther, Cat, Fish. Brit. Mus. iv. p. 456 (copied). Pleuronectes Pcdlasii, Steindachner, Ichth. Beitr., S.B., k. Akad. d. Wiss. Wien, Ixxx. 1880. Platessa quadrituhcrculcUa, Jordan and Goss, Flounders and Soles of Am. and Eur. Rep. U.S. Fish. Com. for 1886, pub. 1889. The original description of quadrituheradatus by Pallas is as follows : — Longitudo {11 " 4'" ) fere pedalis, latitude summa cum pinnis 5 " 11 '" sine pinnis 4 ". Forma Flesi. Caput a latere oculato, fusco nigricante, tuberculis quatuor osseis, conicis obtusis prominentissimis, serie lineae laterali continua, quorum duo approximata anterius, tertium orbitae superioris postico margini contiguum, quartum maximum sinui branchiali adsidet, Linea lateralis in utroque latere a sinu branchial! levissime descendens, dehinc media rectissima speciem cateuulae referens. Corpus glaberrimum, squamis subdistinctis obsoletissimis, Cauda evidentius squamosa usque in radiorum intervalla. Opercula angulata. Pinnae pectorales rad. 11 subacutae ; ventrales falcatae, rad. 6. P. dorsi ab orbitis incipiens rad. 70, P. ani pollicari a ventralibus distantia, rad. 51. Spina subcutanea ad anum. P. caudae rotundata, radiis 18 robustis bifidis. * " Flounders and Soles of America and Europe." Report of U.S. Fish Commisnon for 1886. NEW SERIES. — VOL. IV. NO, 4, 2 A 332 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. Now there is one point in this description which shows that the fish described was not a plaice at all. The four tubercles are not all behind the eyes, but only the third and fourth. Jordan and Goss describe their specimen as having about five tubercles above the operculum, and D. 68, A. 50. Bean gives no description, but states that his specimen was obtained at Kodiak ; Jordan and Goss' specimen was also collected at Kodiak, and it is not clear whether it was the same specimen or whether there were two. Kodiak is a large island off the south coast of Alaska. In the British Museum collection there is a single specimen identified as the quadrituherculatns of Pallas, and collected by the U.S. Fish Com. steamer Albatross. The identification is evidently that of the American naturalists, and the specimen leaves no doubt as to what were the characters of the fish so identified. The specimen was taken at Herendeen Bay, a bay on the north side of the Alaska Peninsula in 5G° north latitude and 161° west longitude. The characters of the specimen are given in the tables below, and it will be seen that they are similar to those of a plaice. The body is rather broad and the head long, but in these respects the fish does not differ from the plaice of the North Sea to any important extent, and it must be remembered that we can make no very minute comparison between spirit specimens and fresh specimens. The tubercles on the head are, however, peculiar, and have a character which has not been observed in any Atlantic plaice ; they are remarkably prominent, regularly conical, and uniform in size. In number and position they are like the tubercles of the plaice. The scales are like those of the plaice, cycloid and reduced so that they do not overlap. The lateral line is slightly elevated above the pectoral fin, but otherwise straight as in the plaice. The specimen is male, and the scales on the fin-rays are spinulated as in the majority of male plaice. The teeth seem to be rather smaller than in the North Sea plaice. We find then that in the North Pacific, about the shores of Kodiak and the Alaska Peninsula, there is a local variety of the plaice, of which only a few specimens have been obtained, and that this form has been erroneously identified with the Fl. quadritv.lercidatus of Pallas. The depth of water at which it was taken is not stated. The only other record we have of a plaice-like fish in the North Pacific is Steindachner's account of PI. Pallasii. The specimens so named came from Kamtchatka. The characters described are five depressed bony tubercles with blunt outer edges in a horizontal row between the eye and the lateral line. Dorsal rays, 63-68 ; anal, 48-53 ; all the fin-rays scaleless ; scales small, rounded. A figure is given showing the tubercles more rounded and less prominent than in the British Museum specimen. South of Alaska and Kamtchatka we have no evidence that the PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 333 Pacific form of the plaice exists. The flat-fishes of California and the west coast of America generally have been attentively studied by American zoologists, and are captured regularly for the market; but no specimens of this form have been noticed except the above, nor have any been discovered in Japan. The plaice-like form again is not known at present to extend further north than Herendeen Bay. Flat-fish have been collected at more northern places on the west coast of Alaska, but specimens of this form were not among them. It appears, therefore, that the species in the Pacific does not extend so far north or so far southwards as in the Atlantic ; but, on the other hand, it is found on the west shores as well as on the east, whereas on the west side of the Atlantic it is absent. Pleuronedes glacialis. Now to the northward, where the plaice disappears, the northern species, glacialis, is found in its stead, and this species occurs along all the northern coasts of Europe and America, and on the east coast of America. It presents local variations, and has been described under various names, but there is no doubt that it constitutes a single species, which in many respects is closely allied to the plaice. The following are the principal synonyms and references : — Pleuronedes glacialis, Pallas, Zoogr. Rosso-Asiatica, iii. p. 424. Pleuronedes cicatricosus, Pallas, ibid. PI. glacialis, Richardson, Voy. H.M.S. Herald, p. 166 (1852). Bean, Proc. U.S. Nat. ]\Ius. 1881, p. 241 (Kotzebue Sound, Northern Alaska). Jordan and Gilbert, Synopsis Fish. N.A. Smitt, Scandinavian Fishes, 1893. Platessa chinensis, Lilljeborg, Svensk Vet. Akad. Hand], 1850. Platessa glabra, Storer, Proc. Boston Soc. Nat. Hist. 1843, p. 130. Liopsetta glabra, Gill, Proc. Acad. Nat. Sci. Philad. 1864. Euchalarodus Puinami, Gill, Proc. Acad. Nat. Sci. Phil. 1864, p. 216. Pleuronedes glaher, Goode and Bean, Proc. U.S. Nat. INIus. 1878, p. 347. Bean, ibid, p. 345. Pleuronedes Franklinii, Giinther, Cat. Fish. Brit. Mus. iv. 1802, p. 442. Pallas first described P. glacialis in 1773, in his account of his journeys through various provinces of Russia; and in his larger work, published in 1811, repeated the description with but little modification. His specimens were taken in the Kara Sea and at the mouth of the river Obi. The chief characters given are the absence of spiny tubercles like those of the flounder; the ridge behind the eyes rough, but not divided into tubercles ; the middle rays of the fins on the coloured side roughened with very minute spines ; dorsal rays, 56; anal, 39. The upper side is also squamulis asperis gramdaUim, which probably means that the upper side was spinulated all over. 834 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. According to Pallas* description P. cicatricosus differs but little from glacialis. The specimens were collected in the sea between Kamtchatka and America, It is said to be more oblong, the length being three times the breadth without the fins. There is a rough osseous ridge behind the eyes. On the upper side tlie scales are far apart and scarcely projecting, except that every third or fifth over all the body and operculum has projecting setae on its margin ; the middle fin -rays are also roughened with slight projecting points. Length of the specimen was 8iV inches, the breadth 2\9i inches ; the number of dorsal rays 59, anal 36. It is clear that the two forms thus described belong to the same species, and it is difficult to decide which was the more spinulated of the two. Eichardson states that he identified as the P. glacialis of Pallas a flounder taken in Bathurst's Inlet, which is on the north coast of North America. He afterwards obtained two specimens from the same region from Dr. Rae. They had all the characters described by Pallas, except the roughness of the middle rays of the dorsal and ventral fins. Eichardson suggests for the first time that this may be a sexual peculiarity. He states that the parietal and suprascapular space— in other words, the post-ocular ridge — is divided into elevated granular surfaces; the scales are small and without spinules, except along the bases of the dorsal and ventral fins on the upper side. The length was 7*5 inches ; the dor^i-al rays 58, the ventral 43. In the British Museum collection there are two specimens identified with Eichardson's species, whicli Dr. Giinther named Franklinii, con- sidering it distinct from glacialis. One of these is 22-8 cm. long (9 inches), and according to the label came from Dr. Eae's collection. It has evidently been dried, and is moth-eaten; but the spinulated scales could be felt both on the fin-rays and on the body. The other specimen has also been dried, and was too hard and stiff for detailed examination ; but this also has some spinulated scales on the fin-rays and the edge of the body. This specimen was labelled, "From the Haslar collection." Probably one of these specimens, or both, were those examined by Eichardson, whose description of the spinulation in such case was incorrect. They are certainly of the same species as the glacialis and cicatricosus of Pallas. The first description of specimens of the same species on the east coast of North America is that of Storer, in 1843, who gives it the name Platessa glabra. He says the body is perfectly smooth, and mentions no spinulated scales on the fins. But the number of the fin-rays (D. 54, A. 39), and the character of the post-ocular ridge (naked and rough, continued back to the superior angle of the opercu- lum, where it is much larger, and terminates in an obtuse point\ show PECULIARITIES OF PLAICE FKOM DIFFEKENT FISHING GROUNDS. 335 that the fish iu question resembled gladalis. The specimens were taken in Boston harbour. In 1864 Gill gave the name Liojjsctta glabra to Storer's species, and described a new species under the name Euchalarodus Putnami. The description summarised is as follows : D. 55-58, A. 39-40. Two specimens examined, obtained at Salem, Mass. Scales minute, distinct, immersed, each one on the coloured side with several slender teeth behind, directed outwards ; on the light side of the body smooth or uniciliate. Lateral line straight. Head with an osseous ridge con- tinued backwards, where it is expanded and separated from an oblique bony tubercle on the scapula. The name was given from the teeth, which were in a single series and movable. In 1878 Tarleton H. Bean pointed out that the movable teeth and certain other minute characters, described by Gill in Euchalarodus, occurred also in P. glabra, and in the plaice, the teeth being movable iu mature specimens in the breeding season ; and that Euchalarodus Putnami was in fact the male of Liopsetia glabra, differing from it only in having more of the scales ciliated. The largest female in the gravid condition was 13i inches long. In the Review of Flounders and Soles, 1889, Jordan and Goss confirm Bean's conclusions, and state that they see no difference by which Liopsetia glabra can be separated from P. gladalis. Specimens have been taken from Providence, Ehode Island, to Labrador, so that the southern limit of the species is 41° north latitude. Specimens identified as the P. gladalis or cicatricosus of Pallas have been taken in recent years by the U.S. Fishery steamer Albatross, on the west coast of Alaska, north of the Alaska Peninsula, The species is recorded by Bean as taken in Kotzebue Sound, but he gives no description ; the same specimens, however, are briefly described by Jordan and Gilbert in their Sgno2)sis of the Fishes of North America. It is there stated that the dorsal rays are 56, the anal 42 in number ; that the scales are minute, imbedded, ctenoid in the males, smooth in the females. Now, the specimen in Bean's catalogue is numbered 27,947, and this very specimen, bearing the same number and labelled from Kotzebue Sound, is now in the British Museum, received from the Smithsonian Institution. I examined it myself, and have recorded its characters in the lists below. It is a female, and yet is strongly ciliated on the fins and all over the body on the upper side, and only a little less on the lower side. On the coast of Alaska then the females are not without spinulation. In Jordan and Goss' Flounders and Soles a female of the same form from Kotzebue Sound is figured, and appears to be the same specimen which I have examined; but the number is quoted as 27,497, probably a mere clerical error. 336 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. There arc two other specimens fi-om Alaska in the British Museum, collected by the Albatross in the Nushagak Eiver, and obtained from the U.S. Fish Commission. These also I have examined, and have recorded their characters below, lioth are females, and immature ; the smaller is ciliated on the fins, head, and central region of the upper side, but not on the interspinous regions ; on the lower side it is also ciliated in the central region. The larger is ciliated all over the upper side, except the region covered by the pectoral, but not on the lower side. Lilljeborg's specimens came from the mouth of the river Dwina, at Archangel, from which place Smitt also obtained specimens. Smitt considers Lilljeborg's species identical with Pallas' cicatricosus, but thinks that there are important differences between this and glacialis. He says that Pallas based his distinction on the deeper form of the body, and greater closeness of the scales in glacialis. The difference reappears, though modified by age and sex, between the specimens brought by Nordenskiuld from the north coast of Siberia, east of the Kara Sea, and the specimens brouglit from the White Sea. The specimens of the east coast of the United States, according to Smitt, also belong to cicatricosus. The narrower form, with fewer or smaller scales, therefore, according to Smitt, occurs in the White Sea, on the east coast of America, and in the Behring Sea ; while the broader form extends along the Arctic shores of America and of Siberia ; the glacialis is a purely Arctic form, while cicatricosus lives in a milder climate. The evidence I have been able to examine does not enable me to test Smitt's conclusions with regard to the breadth of body or length of head very completely. I can only point out that the three specimens from tlie coast of Alaska, one of which at 18'3 cm. was mature, agree fairly closely with the proportions given by Smitt for cicatricosus, and at the same time are not markedly narrower or longer in the head than many of the female plaice from the northern part of the North Sea. The male glacialis examined by Smitt were longer than the cicatricosus, all females, which he examined, and may have been older, which would to some extent account for their greater breadth and shorter heads. Smitt does not discuss the spinulation of the scales, and does not even mention that this is on the east coast of xVmerica a sexual character. In the two specimens from the north coast of North America which I have examined, as far as can be judged from their unsatisfactory condition, the spinulation is not greater than in male plaice from the North Sea, but their sex is unknown. The three specimens from the coast of Alaska are all females, and more spinulated than most of the male plaice from beyond the Dogger Bank. PECULIARITIES OF PLAICE FKOM DIFFERENT FISHING GROUNDS. 337 In these specimens of glacialis, therefore, spinulation is undoubtedly more developed than in the most spinulated plaice, even than in those of the Baltic. On the other hand, the descriptions of the American naturalists do not tend to show that the forms named by them Lioindta Putnami and gkibra are more spinulated than the plaice of the Baltic. It is clear, however, that all the local forms of glacialis differ very distinctly from the plaice in the smaller number of fin-rays and the character of the post-ocular ridge, which is granulated, termina- ting posteriorly in a pear-shaped elevation of the skull-bone, succeeded by a slight elevation of the post-temporal bone. These two elevations correspond to the two posterior tubercles of the plaice, but are not prominent enough to be called tubercles. We have seen that in the White Sea both plaice and glacialis occur ; but this is the limit of the plaice eastwards and of glacialis westwards. The two species similarly succeed one another on the coast of Alaska, the northern limit of the plaice being the northern shore of the Alaskan Peninsula, which also forms the southern limit of glacialis. Glacialis therefore is strictly a geographical representative of the plaice. So far as we know it is, like the plaice, a marine form, not ascending rivers higher than their mouths. There are remarkable and interesting differences in the limits between the two species in different parts of the world, which are found on examination to correspond very closely to differences of temperature depending on ocean currents. In a map of the world by John Bartholomew the seas closed by ice in winter in the north are distinguished, and the distribution of the species glacialis corresponds almost exactly to the area of these seas. Owing to the north-eastern trend of the coast of Scandinavia the Gulf Stream, or north-easterly warm current in the Atlantic, travels far to the north and east, producing an ice-free sea as far as the entrance of the White Sea. Thus the plaice extends on the east side of the Atlantic beyond the North Cape, latitude about 72°, while on the east side of the Pacific its northern limit is about 56°. The westward projection of Alaska stops the north-easterly progress of the warm current in the Pacific, so that Behring Sea is closed by ice in winter, and here we have the form glacialis. Again, the open warmer sea in the Atlantic embraces the south coast of Iceland, where the plaice is not only abundant, but reaches its maximum size ; while the glacial sea extends along the coasts of Greenland, down the west coast of America to Nova Scotia. The southerly cold current, known as the Labrador current, passes down from the north along the coast of Labrador and the east coast of North America, and this fact corresponds to the southerly extension of the glacialis form to Cape Cod, and the entire absence of the plaice. It appears that glacialis is taken 338 PECULIAKITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. on the coast of the United States cliielly, if not exclusively, in winter ; and we may conclude that the low temperature of the water in winter excludes the plaice, while the high summer temperature prevents the extension of glacialis further to the south. Pleuronedes ficsus. We have next to consider the flounder, which is distinguished from the other two species most conspicuously by the character of the scales, many of which are more reduced than in the plaice, while others on particular parts of the body have taken on a peculiar development, and have been enlarged into prominent thorny tubercles. These tubercles are most constantly present in a single row along the bases of the dorsal and ventral fins, and are also usually present on the head and about the lateral line, while in certain forms they are developed over nearly the whole of the skin of the upper side. The species occurs on the east side of the Atlantic all along the coasts of Europe — from the White Sea on the north to the Black Sea at the extremity of the Mediterranean. At different regions within these limits it exhibits local variations. Duncker examined samples from various parts of the Baltic and from the North Sea. In criti- cising his results we must take into account the fact that the flounder is essentially an estuarine iish, often ascending rivers into fresh water, and only descending to the sea in order to spawn. In the Baltic the flounder extends much further than the plaice, and generally exhibits a much greater development of tubercles than on the coasts of the North Sea. Duncker examined samples from Kunigsberg, Greifswald, Niendorf, and Kiel. From Kunigsberg he had 20 males and 8 females ; the males from 19-0 cm. to 28-2 cm. in length, the females from 23'3 to 28'2 cm. They were remarkable for their very rough squamation, great height of body, very short heads, and conspicuous red spots, approximating to the coloration of the plaice. There were crowded small tubercles over the whole of the upper side, on the blind side at least along the lateral line, on the abdomen, and on the inter- spinous region. The average height of body was 399 per cent, in the males, 4M per cent, in the females. The length of head was 22*3 per cent., and also less in the males. The number of fln-rays was higher than in other Baltic samples, the mean of the dorsal being 58-1, of the ventral 407. The number of gill-rakers was 11-18. The Greifswald sample consisted of 14 males, 15 females; the males in length 105 cm. to 260 cm., the females 15-8 cm. to 34-6 cm. In these the squamation was less rough ; the height of body less, 37"8 per cent, on the average ; the head longer. It seems to me all these differ- ences are sufficiently explained by the greater proportion of younger and smaller specimens. The mean numbers of the dorsal and ventral PECULIAUITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 339 rays was a little lower, but in such a small number of specimens the difference does not seem of great importance. From Niendorf and Kiel there were 26 males, 30 females ; the length of tlie males was 201 cm. to 38'5 cm., of the females 208 cm. to 30G cm. According to Duncker the squamation and coloration are intermediate between the Greifswald and Konigsberg forms. The Niendorf males were narrow, and these were few in number and of large size ; the length of head slightly greater than in the Konigsberg sample, a fact very probably due to the greater proportion of females. The mean of the numbers of dorsal fin-rays was only a little over 56, that of the ventral the same as in the Greifswald sample. Duncker's North Sea specimens were collected near Heligoland, therefore in the sea ; at Cuxhaven at the mouth of the Elbe ; and at Hamburg. Considering the migratory habits of the species, it is obvious that these must be considered as belonging to one region, and Duncker admits that they are difiicult to distinguish. The Heligoland specimens are stated to have been obtained in July and August, and it is surprising that flounders should be found abundantly in the sea at that time of the year. But perhaps the fact is explained by the shallowness of the water, and the proximity of the two large rivers Elbe and Weser. We find, however, as might be expected, that the Heligoland specimens are the largest and doubtless the oldest. The numbers and sizes are : — '&^ Heligoland . . 15 males, 23'0 cm. to 3r5 cm. 29 females, 23-8 cm. to 421 cm. Cuxhaven . . 18 males, 224 cm. to 28'0 cm. 7 females, 22*5 cm. to 26*1 cm. Hamburg. . . 14 males, 151 cm. to 27*8 cm. 13 females, 22-2 cm. to 27-8 cm. In these North Sea flounders the rougli tubercles are limited to the bases of the fins and the lateral line, while the scales on the rest of the body are smooth and cycloid ; the tubercles occur chiefly at the anterior part of the lateral line, and in the middle region of the bases of the fins. The number of gill-rakers is on the average two or three higher than in the Baltic (15 to 22). The fin-rays are more numerous. The body is narrower ; but in the length of head no constant difference was evident. I cannot altogether agree with Duncker in his views with regard to the comparison between the variations of the plaice and flounder in the North Sea and Baltic. He considers that the two forms approach one another to some extent in the Baltic more than they do in the North Sea. In the two cases we find a similar modification in the greater roughness of the scales, in the greater breadth of the body, and the reduction in the number of fin-rays. The number of gill-rakurs 340 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. is liiglier in the llouuder than in the plaice, and is reduced in the Baltic ; in this respect the niodilication does reduce the difference between the species, and the difference in the coloration is also reduced in the ]>altic. The length of the caudal peduncle in the llounder is reduced in the Baltic, while in the plaice it is somewhat increased. The three modifications which are in the same direction are those which take place in passing from south to north; and it is a fact that the Baltic is colder than the North Sea. On the other hand, it seems to me probable that as the Baltic is fresher than the North Sea the flounder there may live less in the rivers, and therefore, on the whole, in Salter water, while the plaice lives in fresher, and that this may have some- thing to do with the brighter red spots in the llounder in the Baltic. Tlie flounder in the Mediterranean has been described under different names in the belief that it formed distinct species. The synonyms, or names given to these local forms, are : — Plcuroncdes luscus, Pallas, Zoogr. llosso-Asiat. iii. p. 427. 1811 (Black Sea). Flatessa rjlahra, Rathke, Fauna der Krym., p. 352. 1837 (Crimea). Flatcssa 2JCisser, Bonaparte, Fauna Italica, Pesc. 1838-40. Pleuronedes italicns, Giinther, Cat. Fish. Brit. Mus. iv. 1862 (Dalmatia). I have not taken the trouble to go through the descriptions given by the authors cited, but have examined the specimens in the British Museum, details of whose characters are given in the lists below. The chief peculiarity of italicus, according to Giinther's description, is that the lateral line is smooth, not furnished with thorny tubercles. In the smallest of the three specimens from Dalmatia there were no tubercles on the lateral line, and no spinules on the scales on the middle fin-rays of the dorsal and ventral fins. In the next specimen in order of size there were spinules on 22 of the dorsal and ventral rays, no tubercles on the lateral line or on the head. In the third specimen two tubercles were found at the anterior end of the lateral line, but only one spinule was detected on the dorsal fin, none on the ventral. Spinules on the fins are not present in the North Sea flounders. The number of the fin-rays is not greater than in the North Sea flounders, but is as great, and therefore greater than in the flounders of the Baltic. The height of body also resembles that of the North Sea specimens, while the length of the caudal peduncle is as short as in the Baltic. The length of head shows nothing remarkable. Of the local form described as luscus there were seven specimens in the British Museum : four from Constantinople and the Bosphorus, three from the B>lack Sea. In all these there were a number of tubercles along the front part of the lateral line, but these were not PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 341 very abundant or very prominent. The spinules on the fin-rays were also more numerous and more regular. The fin-rays are scarcely different from those of the Dalmatia form, but the body is higher and the head apparently a little longer; these, however, are differences of age, the body being higher in the larger specimens, the head longer in the smaller. In the ]Mack Sea specimens, as in those from Dalmatia, the tubercles along the bases of the fins are present, more developed in the former. Again, we find here that the greater development of tubercles corresponds to a colder climate ; the Black Sea is considerably colder, at least in winter, than the Adriatic. The presence of spinulated scales on the fin-rays, as in the plaice, is remarkable. On the northern coast of the eastern hemisphere the flounder is not known to occur further east than the White Sea. Smitt states that Lieut. Sandeberg brought specimens from the White Sea in which the body was entirely smooth, with the exception of the spinous tubercles at the bases of the fin-rays, and a few on the head and near the lateral line. They were described as a distinct species under the name Pleuronedes Boydanovii ; but quite similar forms may, according to Smitt, be found in the Baltic. These were apparently individual variations, and it is not clear whether or not the flounder on the whole is as strongly spinous in the White Sea as in the Baltic. The flounder is not included in Liitken's Fishes of Greenland, and is not mentioned as occurring on the north-east coast of North America. Yet there is a form, scarcely distinct as a species, in the Pacific, remark- able chiefly for the extensive development of spiny tubercles, but in the character of these tubercles, and in other respects, very closely similar to the European flounder. The chief difference is, that according to the descriptions of Jordan and Goss there are no cycloid scales in the Paciflc form, to which they actually give a distinct generic name, Platichthys stdlatus. This form extends from Point Conception on the coast of California, latitude 34°, to Coronation Gulf on the Arctic coast of America, which is north of latitude 70°, and not very far west of Hudson's Bay. It is difficult to understand why the flounder-like form should be absent on the intervening coasts, or in the intervening rivers, between the north-west coast of America and the coast of Europe. On the Asiatic side of the Pacific the form stcllatus extends southwards to Saghalien, and indeed from the descriptions appears to be the same species as Fkuroncctcs aqKrrimus of Japan. Smitt suggests in one passage that the forms which culminate in the plaice and flounder started from one of the three liminula (dab) (jlacialis or cicalricosiis, and considers the latter two varieties to be diverging in the same directions as Jlcsits and i^l^i^icssa. Duncker, on the other hand, considers the plaice the oldest form on account of its 342 PECULIARITIES OF PLAICE FPvOM DIFFERENT FISHING GROUNDS. cycloid scales, and to have come from the far north ; to have formed the variety glacialis on the Arctic coasts, and then with this variety to have entered the ]>altic, where the plaice gave rise to the Baltic form of plaice, and the glacialis to the flounder. The conclusions at present suggested by the facts to my own mind are as follows : The plaice is by no means necessarily the original form, as there is reason for holding that the original form of these and other flat-fishes had ctenoid scales of the usual kind, as in the dab. The facts show that the species glacialis is the Arctic form, the flounder the fluviatile form of the plaice. Whatever the causes which led to the reduction of the scales in the plaice, it is certain that the ctenoid condition is more developed in the Arctic form : this form is also without tubercles and has fewer fin-rays. There are objections to the view, which Duncker appears to take, that the development of the tubercles in the flounder is a further stage in the development of the spinules on the scales in the plaice and in glacialis. The most spiuulated scales occur in the two latter forms on the fin-rays and in the interspinous regions, while in the flounder it is precisely in these two regions that the scales are most rudimentary, and along the base of the fins and along the lateral line the scales are developed into spiny tubercles. As we have seen, the spinules on the fin-rays are retained to some extent only in the smoothest flounders, those of the Mediterranean, while in those of more northern latitudes the fin-rays are scaleless. Thus we might almost say that the condition of the flounder was due to the further progress of a modification in the same direction as that of the plaice, that the ctenoid scales first underwent reduction, and then when they had become rudimentary some of them in particular parts of the body developed into tubercles. This view, however, is not consistent with the fact that both plaice and flounder become rougher, their calcified skin armature more developed, in the north than in the south. The correct interpretation of this fact is evidently that the development of scales has taken a different direction in the flounder, and that in both directions cold, or some condition accompanying a northern climate, has the effect of producing enlargement of the structures connected with the scales. It is not possible at present to see any connection between the fact that the flounder lives in rivers, and the peculiar development of its tubercles, nor can we see any advantage to the fish in the possession of these structures. We do not find that the correspondence which is observed between climate and development of spines on the scales in the plaice and flounder exists when we compare the species of flat-fishes with one another. The sole, for instance, is a distinctly southern form, and its scales are strongly ctenoid all over the body. The dab, however, is PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 343 more closely allied to the plaice and flounder, and also has ctenoid scales all over its body, except the area covered by tlie pectoral fin ; ctenoid scales extend also on to the fin-rays. Now it is not a fact that the dab inhabits more northern regions tlian the plaice, and still less than glacialis. On the contrary the dab and plaice are constantly taken together on the same ground. The dab extends on the European coast from the Bay of Biscay to the Kara Sea, and is plentiful on the south coast of Iceland, and is found in the Baltic at least as far east as Goth- land. On the American side of the Atlantic the dab lives in the same latitudes as glacialis, but in a sliglitly different form, described by American naturalists as a distinct species, under the name Limanda ferruginea. In the North Pacific, however, we do find that the local form of the dab, like the local form of the flounder, is rougher than in other parts of the world. This form is described under the name Limanda aspcra, and extends from Sitka and Saghalien to Wrangel Island off the coast of Siberia. Thus, although we find here again that rougher scales in the same species characterise the more northern forms, and appear to indicate a direct influence of climate, we do not find that northern and southern species are constantly distinguished by a similar difference in the character of the scales. The occurrence of spinulation as a secondary sexual character, developing in the males, as such characters generally do, only when maturity is reached, is peculiar to the plaice, and at present we have no evidence that, as Duncker suggests, the character is of any importance in the relations of the sexes. 344 PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. A.— TABLES SHOWING THE CHARACTERS OBSERVED IN EACH SPECIMEN EXAMINED. The specimens of each sex in eacli locality are arranged in order of size. The Height of Body, Length of Head, Length of Caudal Peduncle, and Length of Caudal Fin, are expressed in hundredths of the Total Length. The Total Length is measured from the extremity of the lower jaw to the end of the middle ray of the caudal fin. The degrees of sj)inulation of the scales, often called ciliation, are as follows : — 1. On the fin-rays only : the numbers of si)inulalcd dorsal rays and ventral rays are added together in one column ; the degree on the body is shown in the next column. 2. On tlie fin-raj's, and also on the head in front of the preopercular ])one. 3. Also on the operculum. 4. Also on the body in the region of tlu; interspinous bones. 5. Also on a greater extent of the l)ody. PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. U5 Locality : Plymouth — grounds near Eddystone. Males. Total Number, 15. Lengtli lit. of Length cm. Boily. of Head. 29-3 .. 40 .. 23 .. 29-4 .. 39 .. 23 .. 30-2 .. 38 .. 22 .. 32-2 .. 36 .. 22 .. 32-3 .. 37 .. 21 .. 32-4 .. 39 .. 21 .. 32-5 .. 38 .. 23 .. 32-8 .. 40 .. 21 .. 33-3 .. 39 .. 23 .. 33-5 .. 37 .. 22 .. 337 .. 38 .. 21 .. 33.9 .. 41 .. 22 .. 37-4 .. 39 .. 22 .. 38-7 . 37 .. 21 .. 42-4 .. 35 .. 21 .. Cau. Ped. 5 . 5 . 6 , 5 , 5 , 6 , 6 . 6 . 6 . 5 . 5 . 6 . 5 Cau. Fin. 20 19 19 18 19 18 20 19 19 19 17 18 18 19 ]8 Tubercles. Gill- I?akers. ... 5 ... 9 . ... 5 ... 11 . ... 5 ... 10 . 9 . 11 . 10 . 11 . 10 . 10 . 10 9 10 10 11 D. Rays. 71 74 73 76 72 74 70 67 72 71 77 72 73 7.5 69 A. Rays. 54 55 56 , 56 52 53 52 54 53 56 52 Ciliated Raya. Com- • 'mencing .. 0 .. 36 .. 37 .. 37 .. 31 .. 58 .. 40 .. 0 .. 55 .. 40 .. 50 .. 43 .. 37 .. 40 Cil. Rudy. 0 0 2 2 2 0 4 0 0 3 2 2 2 0 0 Matu- rity. i III m i m i ni ? ? in m ? m 111 III Females. Total Numbeu, 21. 29 30 30 30 30 31 31 32 32 32 34 35 35 36 37 38 39 39 40 42 43 38 . 38 . 40 . 37 . 41 . 38 . 39 . 39 . 38 . 38 . 38 . 38 . 40 . 41 . 40 . 38 . 38 . 37 . 36 . 38 . 39 . .. 23 .. 22 .. 21 .. 23 .. 24 .. 22 .. 22 .. 21 .. 22 .. 22 .. 22 .. 23 .. 21 .. 22 .. 23 .. 22 .. 22 .. 23 .. 21 .. 21 .. 23 6 . 5 . 5 . 6 . 5 . 6 . 5 . 6 . 5 . 6 . 5 . 6 . 7 6 . 5 . 6 . 6 . 5 . 6 . . 18 . 19 . 19 . 18 . 19 . 20 . 18 . 19 . 19 . 20 . 17 ,. 23 ,. 17 .. 18 .. 18 ,. 18 .. 18 .. 20 .. 18 ,. 17 .. 18 5 5 5 5 5 5 5 5 5 5 5 7 6 5 4 5 5 5 5 5 9 10 10 10 10 9 10 ? 10 10 9 10 10 10 10 10 10 11 11 10 9 75 75 75 74 72 76 75 75 71 74 75 66 71 74 72 74 72 75 72 76 68 0/ 55 55 53 55 56 55 54 ... — 52 ... — 56 ... — 55 ... — 56 ... — 56 ... — 57 ... — 51 ... — •• 1 — .. — .. in — ., — .. m m — .. — .: in 111 — .. — .. m — .. m — .. 111 — .. m — .. m — .. m — m 346 PECULIAPJTIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. Locality : Brown Ridges, North Sea. II.VLE.S. Total NuMisEU, 52. Length, lit. of Length Can. Caa. Tubercles. Gill D. A. Ciliated Cil. Matu cm. Hotly. of Head. Pod. Fin. Rakers. Rays. Rays. Kays. Body. rity. 22 1 . . 36 .. 24 . .. 5 .. . 18 .. 5 .. 11 ... 72 . .. 53 ... 0 . . 0 .. i 24 9 . . 37 .. 22 . .. 5 .. . 21 ... 5 .. 10 ... 68 . .. 51 ... 0 . . 0 .. . i 26 2 . . 39 .. 21 . .. 6 .. . 18 .. 5 ... n ... 74 . . 55 ... 42 . . 0 .. i 26 9 . . 40 .. 22 . .. 6 .. . 18 .. 5 ... 9 ... 73 . . 55 ... 29 . . 0 .. i? 27 5 . . 39 22 .. 6 .. . 17 .. 5 ... 10 ... 73 . . 54 .. 17 . . 0 .. i? 27 5 . . 38 .. 22 . .. 6 .. . 18 .. 5 ... 9 ... 74 . . 56 ... 9 . . 0 .. i? 27 7 . . 37 .. 21 . .. 6 .. . 18 .. 5 ... 9 ... 71 . . 53 ... 35 . . 0 .. ? 28 1 . . 39 22 .. 6 .. . 18 .. 5 .. 10 ... 72 . . 53 ... 36 . . 2 .. — 28 3 . . 39 . .. 22 . .. 6 .. . 18 .. 5 ... 10 ... 78 . . 57 ... 37 . . 0 .. — 28 4 . . 39 .. 22 . .. 6 .. . 19 .. 5 ... 9 ... 76 . . 55 ... 34 . . 2 .. m 28 5 . . 38 .. 23 . .. 5 .. . 19 .. 5 ... 10 ... 78 . . 55 .. 26 . . 0 .. — 28 6 . . 39 . .. 22 . .. 5 .. . 17 .. 5 .. 10 ... 73 . . 56 ... 42 . . 2 .. m 28 8 . . 37 . .. 22 . .. 5 .. . 19 .. 5 ... 9 ... 73 . . 53 ... 32 . . 0 .. — 28 8 . . 38 . .. 21 . .. 6 .. . 18 .. 5 ... 10 ... 69 . . 53 .. 42 . . 0 .. — 29 2 . . 40 .. 22 . .. 5 .. . 17 .. 6 ... 9 ... 73 . . 52 .. 36 . . 2 .. — 29 3 . . 37 . .. 22 . .. 5 .. . 18 .. 5 ... 10 ... 75 . . 54 .. 39 . . 0 .. — 29 5 . . 38 .. 22 . .. 6 .. . 18 .. 5 ... 10 ... 73 . . 52 .. 39 . . 2 .. m 29 6 . . 39 . .. 22 . .. 6 .. . 18 .. 5 ... 10 ... 71 . . 51 .. 21 . . 0 .. — 30 0 . . 38 . .. 22 . .. 6 .. . 18 .. 5 ... 11 ... 71 . . 52 .. 24 . . 0 .. — 30 0 . . 40 .. 23 . .. 6 .. . 19 .. 5 ... 10 ... 72 . . 53 ... 10 . . 0 .. — 30 1 . . 37 .. 22 . .. 6 .. . 18 .. 5 ... 10 ... 76 . . 56 ... 42 . 2 m 30 1 . . 39 . .. 21 . .. 6 .. . 17 .. 5 ... 12 ... 72 . . 55 ... 32 . . 0 .. — 30 3 . . 37 .. 22 . .. 5 .. . 18 .. 5 ... 10 ... 74 . . 55 ... 40 . . 2 .. — 30 3 . . 40 . .. 22 . .. 6 .. . 18 .. 6 ... 11 ... 75 . . 55 .. 25 . . 2 .. m 30 7 . . 40 .. 22 . .. 5 .. . 17 .. 5 ... 10 ... 74 . . 55 .. 37 . . 0 .. — 30 7 . . 38 . .. 23 . .. 5 .. . 22 .. 5 ... 10 ... 70 . . 51 ... 9 . . 0 .. — 31 2 . . 38 . .. 22 . .. 7 .. . 17 .. 5 ... 10 ... 73 . . 55 .. 47 . . 3 .. m 31 6 . . 41 . .. 22 . .. 6 .. . 18 .. 5 ... 9 ... 77 . . 58 .. 33 . . 0 .. m 31 8 . . 38 . .. 22 . .. 5 .. . 18 .. 5 ... 10 ... 70 . . 55 .. 48 . . 2 .. — 32 0 . . 38 . .. 21 . .. 6 .. . 21 .. 6 ... 9 ... 73 . . 54 ... 37 . . 2 .. m 32 1 . . 38 . .. 23 . .. 6 .. . 19 .. 5 ... 9 ... 72 . . 53 .. 41 . . 2 .. m 32 3 . . 39 . .. 22 . .. 6 .. . 16 .. 5 ... 9 ... 73 . . 55 .. 47 . . 2 .. — 32 4 . . 38 . .. 21 . .. 6 .. . 18 .. 6 ... 9 ... 70 . . 52 ... 41 . . 2 .. m 32 9 . . 36 .. 21 . .. 6 .. . 18 .. 6 ... 9 ... 70 . . 53 .. 34 . . 0 .. — 32 9 . . 39 . .. 22 . .. 5 .. . 20 .. 5 ... 10 ... 69 . . 50 .. 35 . . 2 .. — 33 2 . . 37 . .. 21 . .. 6 .. . 18 .. 5 ... 10 ... 73 . . 53 .. 36 . . 2 .. — 33 4 . . 39 . .. 22 . .. 6 .. . 18 .. 5 ... 10 ... 68 . . 50 .. 26 . . 2 .. m 33 8 . . 36 . .. 20 . .. 4 .. . 17 . .. 5 ... 11 ... 71 . . 55 .. 39 . . 3 .. — 33 8 . . 36 . .. 21 . .. 4 .. . 17 .. 5 ... 9 ... 75 . . 58 .. 47 . . 2 .. — 34 1 . . 36 . .. 20 . .. 6 .. . 16 .. 6 ... 10 ... 76 . . 53 .. 25 , . 2 .. — 34 2 . . 36 . .. 22 . .. 5 .. . 19 .. 5 ... 10 ... 75 . . 57 .. 0 . . 0 .. — 34 2 . . 39 . .. 22 . .. 5 .. . 19 .. 5 ... 11 ... 73 . . 52 .. 37 . . 0 .. m 34 6 . . 40 . .. 21 .. 7 .. . 19 .. 5 ... 9 ... 75 . . 55 .. 17 . . 0 .. m 34 8 . . 37 . .. 22 . .. 6 .. . 18 .. 5 ... 11 ... 68 . . 51 .. 26 . . 0 .. PECULIAKITIES OF PLAICE FROM DIFFERENT FISHIKG GROUNDS. S-l? Males — continued. Length, nt. of Length Cau. Cau. Til bercle s. Gill D. A. Ciliated Cil. Matu cm. Body. of Head. Ped. Fin. Rakers. Rays. Rays. Rays. Body. rity. 34-8 . . 40 . . 20 ... 5 .. 18 ... 5 . .. 9 .. . 67 .. . 51 .. 39 . . 2 ... — 35-1 . . 36 . . 20 ... 6 .. 17 ... 5 . .. 9 .. . 76 .. . 56 .. 35 . . 3 ... — 35-4 . . 35 . . 20 ... 6 .. 19 ... 5 . .. 11 .. . 74 .. . 56 .. 44 .. . 2 ... — 35-7 . . 38 . . 22 ... 6 .. 17 ... 6 . .. 11 .. . 76 .. . 56 2 . 0 ... — 35-8 . . 39 . . 20 ... 7 .. 18 .. 7 . .. 10 . . 71 .. . 52 .. 41 . . 2 ... — 35-8 . . 39 . . 20 ... 5 .. 18 ... 5 . .. 11 .. . 69 .. . 54 .. 36 . . 3 ... ra 36-0 . . 40 . . 21 ... 6 .. 17 ... 7 .. 10 .. . 74 .. . 55 .. 39 .. 2 — 36-8 . . 41 . 22 ... 5 .. 18 ... 6 . .. 10 .. . 75 .. . 58 .. 41 .. 2 m Fi :males. Total Number, 57. 24-9 . 37 . . 22 ... 6 .. 18 ... 5 . .. 12 .. . 72 .. . 51 .. 0 .. . 0 ... m 25-1 . . 37 . . 22 ... 5 .. 18 ... 6 . .. 10 .. . 77 .. . 57 ... — . . — ... i? 25-1 . . 40 . . 24 ... 6 .. 19 ... 6 . .. 10 .. . 72 .. . 50 .. — .. . — ... i 26-0 .. . 38 . . 23 ... 6 ... 19 ... 5 . .. 10 .. 71 .. 51 .. — .. . — ... i 26-1 . . 39 . . 23 ... 5 .. 18 ... 5 .. 10 .. . 70 .. . 52 .. — .. . — ... — 26-4 . . 36 . . 23 ... 6 .. 18 ... 5 . .. 9 .. . 70 .. . 51 ... — . . — ... i 26-6 . . 39 . . 23 ... 7 .. 17 ... 5 . .. 10 .. . 72 .. . 55 .. — . . — ... i 267 . . 38 . . 22 ... 5 .. 18 ... 5 . .. 10 .. . 71 .. . 54 .. — .. . — ... i 27 0 . . 37 . . 22 .. 5 .. 19 ... 5 .. 9 .. . 72 .. . 55 ... — . . — ... i 27-5 . . 39 . . 23 ... 5 .. 19 ... 5 . .. 10 .. . 73 .. . 54 .. — . . — ... i 27-7 . . 39 . . 22 ... 6 .. 17 ... 5 .. — .. . 74 .. . 56 ... — . . — ... — 27-8 . . 39 . . 23 ... 6 .. 20 ... 5 .. 9 .. . 72 .. . 55 ... — . . — .. 1 28-1 . . 40 . . 22 ... 6 .. 17 ... 5 .. 10 .. .75 .. . 57 ... — . . — .. i 28-2 . . 38 . . 23 ... 6 .. 17 ... 5 .. 10 .. . 76 .. . 57 ... — . . — .. i 28-5 . . 37 . . 23 ... 6 .. 17 ... 5 .. 11 .. . 70 .. . 50 ... — . . — .. i 28-8 . . 39 . . 22 ... 5 .. 17 ... 5 .. 11 .. . 70 .. . 54 ... — . . — .. ra 29-7 . . 38 . . 23 ... 7 .. 17 ... 5 .. 9 .. . 69 .. . 51 ... — . . — .. i 29-8 . . 38 . . 23 ... 6 .. 18 ... 5 .. 10 .. . 76 .. . 58 ... — . . — .. i 29-8 . . 38 . .. 22 ... 6 .. 18 ... 5 .. 10 .. . 75 .. . 54 ... — . . — .. i 30-3 . . 39 . .. 22 ... 6 .. 18 ... 5 .. 10 .. . 76 .. . 56 ... — . . — .. i 30-4 . . 38 . . 22 ... 6 .. 18 ... 5 .. 10 .. . 79 .. . 58 ... — . . — .. i 30.5 . . 40 . . 23 ... 6 .. 18 ... 6 .. 11 . 77 .. . 55 ... — . . — .. i 30-5 . . 37 . . 21 ... 6 .. 18 ... 6 .. 10 .. . 70 .. . 52 ... — . . — .. i 30-6 . . 39 . .. 22 ... 5 .. 19 ... 6 .. 11 . . 76 . . 58 ... — . .. — .. i 30 6 . .. 38 . .. 22 ... 7 .. . 17 ... 5 .. 10 . . 75 .. . 53 ... 19 . . 0 .. ra 30-8 . . 41 . .. 21 ... 6 .. 20 ... 5 .. 10 . . 75 .. . 55 ... — . . — .. ra 31-1 . . 38 . .. 22 ... 6 .. 18 ... 5 .. 10 . . 71 .. . 52 ... — . .. — .. m 31-2 . . 37 . .. 23 ... 6 .. . 20 .. 5 .. 11 . . 69 . . 51 ... — . .. — .. 31-2 . . 40 . .. 21 ... 6 .. 17 ... 5 ... 10 . . 78 . . 57 ... — . .. — .. i 31-2 . .. 38 . . 22 ... 5 .. . 19 ... 5 ... 10 . . 71 . . 52 ... — . .. — .. ra 31-6 .. 40 . . 22 ... 5 .. . 18 ... 5 ... 10 . . 73 . 53 ... — . .. — .. ra 31-6 . .. 40 . .. 22 ... 5 .. . 19 ... 5 ... 10 . . 71 . . 51 ... — . .. — .. 31-7 . .. 39 . .. 22 ... 6 .. . 18 ... 5 ... 10 . . 81 . . 59 ... — . .. — .. . i 31-9 . .. 36 . .. 21 ... 6 .. . 17 ... 5 ... 9 . . 75 . . 58 ... — . .. — .. . i 31-9 . N .. 39 . EW .SKR .. 23 ... 5 .. lES.— VOL. IV. . 18 ... NO. 4. 6 ... 9 . . 73 . . 55 •^~ 2 B 348 PECULiARiriES of plaice from different fishing grounds. Locality: Brown Ridges, North Sea. Females — continued. Length, Ht. of Length Can. Can. Tubercles Gill D. A Ciliated Cil. Matn cm. Body. of Head. Fed. Fin. Rakers. Rays. Rays. Rays. Body. rity. 31 9 . . 41 . .. 22 . . 5 .. . 17 . .. 5 .. . 10 .. . 74 . .. 55 ... — .. . — ... i 32 1 . . 38 . .. 23 .. . 5 .. . 18 . .. 5 .. . 10 .. . 70 . .. 52 ... — .. . — .. i 32 4 . . 39 , .. 23 . . 6 .. . 17 . .. 6 .. . 11 .. . 74 . .. 52 ... — .. . — . .. m 32 6 . . 37 . . 23 .. . 6 .. 18 . .. 5 .. . 11 .. . 76 . .. 55 ... — .. . — . .. — 33 3 . . 36 . .. 23 . . 6 .. . 17 .. 5 .. . 10 .. . 79 . .. 57 .. — .. . — .. — 33 4 . . 39 . .. 23 . . 6 .. . 18 .. 6 .. . 10 .. . 69 .. 50 .. — . . — .. — 33 9 . . 36 . .. 21 . . 5 .. . 18 .. 5 .. . 10 .. . 75 .. 55 .. — . . — .. — 34 0 . . 40 . .. 22 . . 5 .. . 18 .. 5 .. . 10 .. . 70 .. 51 .. — . . — .. — 34 2 . . 39 . .. 22 . . 6 .. . 18 .. 5 .. . 9 .. . 79 .. 57 .. — . . — .. — 34 3 . . 39 . .. 21 . . 6 .. . 18 .. 6 .. . 10 .. . 68 .. 53 .. — . . — .. — 34 •3 . . 39 . .. 22 . . 5 .. . 17 .. 5 .. . 11 .. . 74 .. 54 .. — . . — .. m 34 8 . . 36 . .. 20 . . 5 .. . 17 .. 5 .. . 10 .. . 74 .. 55 .. — . . — .. — 34 •8 . . 40 . .. 22 . . 6 .. . 18 .. 5 .. . 10 .. . 73 .. 54 .. — . . — .. m 36 1 . . 36 . .. 21 . . 6 .. . 18 .. 6 .. . 9 .. . 73 .. 56 .. — . . — .. — 36 2 . . 39 . .. 22 . . 6 .. . IS .. 5 .. . 11 .. . 77 .. 57 .. — . . — .. — 36 4 . . 39 . .. 23 . . 6 .. . 19 .. 6 .. . 10 .. . 68 .. 52 .. — . . — ... m 37 0 . . 38 . .. 22 . . 6 .. . 17 .. 6 . . 11 .. 77 .. 55 .. — . . — . . . m 37 •3 . ... 39 . .. 21 .. . 5- .. . 19 .. 5 . . 10 .. . 71 ... 55 .. — . . — . . . in 37 7 . . 39 . .. 22 . . C .. . 18 .. 5 . . 10 .. . 68 .. .54 .. . — . . — ... m 38 •4 . . 41 . .. 23 . . 5 .. . 19 .. 5 .. . 13 .. . 64 .. 48 .. — . . — ... m 38 9 . . 39 . .. 23 . .. 5 .. . 18 ... 5 . . 10 . . 76 ... 56 .. . — .. — .. m 39 •4 . . 39 . .. 22 . . 5 .. . 18 .. 5 .. . 11 .. . 76 .. 55 .. — — ... m jTSDSl ^49 Loealiiw: Xinf^ CwuL Maims. Icial Xnaii. 4f. 1^" r~ -- zt Lae^ Can. ■:-t- w. . .... a.. _- 0 _- ca. saew. - 23 ... « . . i.r ... » ._. i« _. i^ ... >4 - 24 _ C ... 17 s .-- 10 , 7S *-• 55 „. 21 _. — - - - ... 24 ... c ... 20 _. 4 .— 9 — « fii ... 53 „. 0 _ — 34 « — 38 -.. ft - 5 ... ^ ^ ... C ..« It •M n ••. 53 .. 21 _ ^^ ^^™ tft-S — . 38 — 23 ... 5 . . 1* „. 3 ..- 10 ,., «7 ,,, 51 1- 38 _- _ 25-2 ... 42 - — 22 _ 5 !7 ... 5 .-. 10 ... 74 ... » _ 37 _ 0 .. — 25-3 — 3S ... S „. 5 :« 5 10 .„ 79 ... 5« _ 27 _ 0 .. ., — 25-8 ... 40 ... 22 ... i — *** ... 5 — . 9 ... n 54 — i^^i — — 3«-l ... 37 -.- 23 ... • ... id ... 3 ... 11 •-■. 70 ... 34 _ S : as^ 40 22 ... 3 ... 19 — 4 — . 8 ... 7* 52 r 27-1 — 37 22 ... 5 ... 13 _- 5 » 10 ... < - - r 1: i 27-3 ..« 38 ... 22 J • • t . . - .- : f : 2S-3 ... 38 ... Sz ... ; Ij ... = ^.. ... ■ — ... . ■ : 28-8 .«. 3i — 22 _. 5 „ IS — 7 — 10 . ft — 55 ... 43 3 — 29"2 40 ... 21 ... « _. 19 ... 5 _— 11 — - 74 57 ... 37 - — 2»-3 39 22 _ 7 „- IS — 5 70 .-. IS -■- — 29-5 42 _— 23 7 17 ... 3 r 7? r^j. ; r _ — 29-5 . _ 40 S ... « ... 21 _ C — 11 _. - - . . — »0 3? 22 — « _ r 5 ... 10 _. 7^ _.- 5« • r _ — 30-3 3« 2S .„ C .. 1; 3 ^_, « -£ r - — . a»^ 41 ... 24 ... » ... 17 ... 5 - ■ — Sl^ 37 21 ... i _ T - f . 72 -«. 52 27 — 32 tS 1 3S 21 -_ 5 _'. i 10 7± 33 44 ^ — «-2 39 22 ... C . L.'- ... 5 9 n , 33 z2 _. o — 33-3 .-. 37 - — 21 ... C ... 15 _ 5 ■~. 10 .-- n 33 -. 34 _ li — 33-2 39 — 3 _. « ... - I .■ . 9 74 54 ... t _. - — »-3 •*. 40 22 ... « ... Ij" .. w- — . 11 — .. «3 --« 50 „ 33 ... . '. 31^ . 3S 22 — 5 ... 1« — 5 __- 10 PS 57 *a - 1 K-1 ... 37 fS ... 5 ... - % ... « 10 72 .. i"~ — S-3 «.- 40 ... '^v* ... 5 ... A ■ ... e --. It «i. 7S ... 5: — »-5 9i 21 ... 5 ... f*5 ... 5 — 10 m^^ 70 57 . -r-i . . s 35-5 3» f;2 ■5 ... I? .. « — 10 ... 74 5* 2» 2 . — 35^ 3« 3 .. i 1* .. 5 _• 10 _. 7-5 «*« Cnm- 2 - i 38-0 39 f2 ... « -. IJ .. 5 10 73 57 ... 49 ... 3 .. . — 9S-5 ... 3« 2"; .. « ... 17 --. « la 74 ... 54 2S 0 - - — 3C-5 3S 22 . - « . . li ... 5 . 73 50 _. 0 _. 0 - . m 3«-S ... 3S ±2 — € ... U ... 5 ... 10 7S 50 iX 3 . — 3S-9 ... 39 22 ... « \ , . 4 9 75 53 ... S7 . 2 ^ 37-0 37 21 ... « - ; 5 It ... 73 59 ... as . . 2 -- n 37-7 ».- 3» 21 ... < 'J . 4 .-• It m»m. n 54 ... 32 .. 3 -- - n. 3£-3 . _ : 1' 5 — 73 5« ... #7 ... 2 . — 3§-« .-. -rl- _ _ ■i .J S 10 70 51 ... 4 ... '? . = 3»-l » 22 r If % 10 74 ... 54 .. 52 .. ■a — 40-4 40 21 .. -5 ... :5 4 - 10 n ... 54 .. » .. 4 . — 40-5 39 22 ... -5 ... I.- i — 11 71 51 ... S5 - . r: 43-0 ... 40 22 5 ... li" — 5 10 74 5S ... 51* - — 43-1 «.- 41 — - 21 _. 0 _. 19 ... 5 12 — 74 --. 53 42 4 — 43-2 ... 40 22 ... C ... 19 ... 5 75 » ... 50 .. 2 — 4S-9 St --2 .- T • « 74 ... 53 ... 44 i — 350 rECULTARITIES OF PLAICR FROM DIFFERENT FISHING GROUNDS. Locality: Norfolk Goad. Females. Total Numbei:, 91. Length, Ut. of Length Can. Cau. Tubercles Gill D. A. Ciliate.1 Cil. Hatu cm. Body. of Hea .. . 10 .. . 73 . . 53 ... — ... — 34 7 . . 39 .. . 21 . . 5 .. . 20 . . 5 .. . 11 .. . 75 . . 55 ... — ... — 34 9 . . 40 .. . 21 . . 6 .. . 19 . . 5 .. . 10 .. . 74 . . 55 ... — ... — 34 9 . . 41 .. . 23 . . 6 .. . 19 . . 5 .. . 10 .. . 72 . . 52 ... — ... — 35 1 . . .39 .. . 22 . . 6 .. . 19 . . 5 .. . 11 .. . 72 . . 52 ... — ... — 35 1 . . 38 .. . 24 . . 6 .. . 17 . . 5 .. . 9 .. . 73 . . 53 ... — ... — 35 1 . . 37 .. . 23 . . 6 .. , 18 . . 6 .. . 8 .. . 71 . . 53 ... — ... — 35 4 . . 38 .. . 22 . . 5 .. . 19 . . 6 .. . 11 .. . 72 . . 54 ... — ... — .. m 35 5 . . 40 .. . 23 . . 6 .. . 19 . . 5 .. . 11 .. . 74 . . 53 ... — ... — 35 7 . . 39 .. . 22 . . 6 .. . 18 . . 5 .. . 9 .. . 70 . . 53 ... — ... — 36 0 . . 40 .. . 23 . . 6 .. . 20 . . 5 .. . 10 .. . 72 . .. 52 ... — ... — 36 •5 . . 38 .. . 22 . . 6 .. . 19 . . 7 .. . 9 .. . 76 . .. 54 ... — ... — 36 •6 . . 39 .. . 22 . . 6 .. . 18 . . 5 .. . 9 .. . 72 . .. 54 ... — .. — 36 6 . . 37 .. . 22 . . 5 .. . 18 . . 5 .. . 10 .. . 79 . . 61 ... — ... — 36 •7 . . 42 .. . 23 . . 5 .. . 18 . . 5 .. . 8 .. . 67 . . 52 ... — ... — 36 7 . . 39 .. . 23 . . 5 .. . 19 . . 5 .. . 10 .. . 70 . . 52 ... — ... — .. — 37 0 . . 37 .. . 24 . . 6 .. . 18 . . 5 .. . 11 .. . 78 . . 57 ... — ... — 37 9 . . 37 .. . 23 . . 6 .. . 18 . . 5 .. . 11 .. . 70 . . 52 ... — ... — 37 ■9 . . 36 .. . 23 . . 6 .. . 19 . . 3 .. . 10 .. . 78 . . 57 ... — .. — 38 2 . . 37 .. . 23 . . 6 .. . 18 . . 5 .. . 11 .. . 72 . . 55 ... — ... — . 38 5 .. . 39 .. . 22 . . 5 .. . 19 . . 5 .. . 12 .. . 72 . . 53 ... — ... — 38 6 . . 40 .. . 22 . . 5 .. . 20 . . 4 .. . 11 .. . 73 . . 53 ... — ... — 38 8 . , 38 .. . 22 . . 6 .. . 18 . . 4 .. . — .. . 70 . . 51 ... 20 ... 0 . PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 351 Females — continued. Length, cm. 39 39 39 40 40 40 40 40 40 40 41 42 43 43 44 44 45 45 45 45 46 46 46 46 47 47 48 49 49 49 49 51 51 51 52 52 52 54 55 56 56 63 Ht. of Body. Length of Head. Cau. Fed. •1 . . 39 . . 23 . . 6 ... ■2 . . 42 . . 22 . . 6 ... •8 . . 38 . . 24 . . 5 ... •0 . . 40 . . 22 . . 6 ... •2 . . 40 . . 22 . . 5 ... •3 . . 38 .. . 23 . . 6 ... •5 . . 39 . . 22 . . 6 ... •7 . . 39 . . 22 . . 6 ... •7 . . 37 .. . 22 . . 5 ... •9 . . 39 . . 22 . . 7 ... •8 . . 38 .. . 22 . . 5 ... •5 . . 39 . . 23 . . 5 ... ■4 . . 43 .. . 22 . . 5 ... •7 . . 37 . . 22 . . 5 ... •0 . . 42 . . 23 . . 5 ... •7 . . 39 . . 21 . . 6 ... •0 . . 39 . . 22 . . 6 ... •0 . . 38 . . 22 . . 6 ... ■5 . . 37 . . 23 . . 6 ... •7 . . 37 . . 22 . . 5 ... •0 . . 36 . . 22 . . 6 ... •2 . . 40 . . 21 . . 6 ... ■3 . . 39 . . 23 . . 6 ... •8 . . 39 . . 23 . . 5 ... •4 . . 40 . . 22 . . 7 ... •5 . . 38 . . 23 . . 5 ... •2 . . 40 . . 23 . . 6 ... •2 . . 37 . . 23 . . 6 ... •3 . . 39 . . 23 . . 5 ... •5 . 40 . . 25 . .5 ... •7 . . 38 . . 23 . . 5 ... •0 . . 39 . . 21 . . 6 ... •6 . . 37 . . 23 . . 6 ... •9 . . 38 . . 23 . . 5 ... •7 . . 36 . . 23 . . 5 ... ■8 . . 38 . . 22 . . 6 ... •9 . . 38 . . 21 . . 5 ... •8 . . 38 . . 22 . . 5 .. •9 . . 39 . . 23 . . 5 ... •3 . . 38 . . 25 . . 5 ... •8 . . 40 . . 24 . . 5 ... •0 . . 36 . . 24 . .. 5 ... Cau. Tubercles Gill D. A. Fin. Rakers. Rays. Kays 17 ... 5 .. . 9 .. . 72 . .. 53 18 ... 5 .. . 9 .. . 76 . .. 54 19 ... 5 .. . 9 .. . 73 . .. 54 19 ... 5 .. . 10 .. . 75 . .. 56 19 ... 5 .. . 11 .. 74 . .. 53 18 ... 5 .. . 11 .. 68 . .. 50 19 ... 5 .. . 11 .. 70 . .. 51 19 ... 5 .. . 10 .. 69 . .. 52 17 .. 5 . . 10 .. 76 . .. 56 18 ... 5 .. . 10 .. 75 . .. 56 19 ... 5 .. . 11 .. 76 . .. 55 20 ... 5 .. . 10 .. . 74 . . 55 18 ... 5 .. . 10 .. . 71 . .. 55 19 ... 5 .. . 12 .. . 75 . .. 58 20 ... 4 .. . 10 .. . 74 . .. 55 20 ... 5 .. . 10 .. . 73 . .. 55 20 ... 5 .. . 10 .. . 73 . .. 55 16 ... 5 .. . 10 .. . 71 . .. 54 17 ... 5 .. . 12 .. . 75 . .. 55 18 ... 5 .. . 10 .. . 75 . .. 55 18 ... 4 .. . 10 .. . 76 . .. 57 19 ... 5 .. . 9 .. . 73 . .. 53 18 ... 6 .. . 10 .. . 71 . .. 52 18 ... 3 .. . 11 .. . 70 . .. 52 17 ... 5 .. . 10 .. . 70 . .. 53 17 ... 4 .. . 11 .. . 78 . .. 56 18 ... 5 .. . 9 .. . 74 . .. 55 18 ... 5 .. . 10 .. . 74 . .. 56 18 ... 4 .. . 12 .. . 76 . .. 56 18 ... 4 .. . 10 .. . 70 . .. 54 19 ... 5 .. . 11 .. . 73 . .. 53 17 ... 5 .. . 11 .. . 76 . .. 57 18 ... 5 .. . 10 .. . 71 . .. 57 17 ... 2 .. . 10 .. . 74 . .. 55 18 ... 2 .. . 9 .. . 73 . .. 54 19 ... 5 .. . 10 .. . 75 . .. 53 19 ... 3 .. . 8 .. . 72 . .. 54 20 ... 3 .. . 11 .. . 75 . .. 55 20 ... 5 .. . 11 .. . 76 . .. 57 17 ... 5 .. . 8 .. . 75 . .. 55 16 ... 5 .. . 11 .. . 72 . .. 52 16 ... 5 . . 11 .. . 76 .. 56 Ciliated Rays. Cil. Uodv 23 Matu- rity. m i m i in i lU m m i in lU in ni ni in ni ni m m ni ni in m in m in ni m m 111 m 111 in m m m ui m in 352 PECULIAlU'llES OF PLAICE FROM DIFFEUENT FISHING GROUNDS. Leugth, cm. 28 32 32 35 35 36 38 39 42 42 42 43 43 46 47 47 3 Locality : North-eastern end of Dogger Bank, 25 fathoms. Males. Total Number, 16. D. Rays. 72 70 Ht. of Length Can. Body, of liead. Ped. 5 7 38 40 41 40 39 38 40 41 42 41 42 42 40 42 39 35 Can. Tubercles Fin. 22 22 21 20 23 22 22 22 21 21 22 22 23 21 21 19 6 7 6 6 5 6 5 6 6 7 6 6 5 5 19 18 19 18 18 17 19 18 19 19 17 16 18 18 19 17 5 5 5 5 5 5 5 6 6 5 5 5 5 5 7 5 Gill Rakers. 13 . 10 . 10 . 11 . 10 . 10 . 11 . 9 . 12 . 10 . 10 . 10 . 9 . 10 . 10 . 9 . 73 70 69 70 74 70 73 68 69 72 74 74 70 75 A. Rays. 54 53 54 52 54 55 56 53 54 52 52 55 54 52 55 54 Ciliated Kays. 0 0 33 44 17 36 34 34 42 31 44 39 42 41 43 48 Cil. Body 0 0 2 3 2 2 2 0 2 4 4 4 4 4 4 5 Matu- rity. i i i m i ? ra m m m m m m m ni 30 31 33 35 35 38 40 40 40 40 42 43 44 44 44 45 45 45 45 45 45 49 49 50 53 55 57 ... 41 ... 38 ... 38 ... 39 ... 40 ... 41 ... 43 ... 37 ... 42 ... 41 ... 40 ... 41 ... 39 ... 39 ... 40 ... 42 ... 40 ... 39 ... 38 ... 39 ,.. 39 ... 41 ... 41 ... 39 .. 40 .. 40 .. 41 23 24 23 22 22 22 23 22 23 23 22 21 23 22 23 22 21 22 21 22 22 22 21 21 21 22 24 Females. ... 18 ... ... 19 ... ... 18 ... ... 19 ... ... 17 ... ... 18 ... ... 18 ... ... 19 ... ... 19 ... ... 18 ... ... 18 ... ... 17 ... ... 19 ... ... 17 ... ... 19 ... ... 19 ... ... 18 ... ... 17 ... ... 17 ... ... 17 ... ... 18 ... ... 16 ... ... 17 ... ... 18 ... ... 17 .. ... 18 ... ... 17 ... Total Number, 27. 5 5 5 6 5 6 5 5 5 5 6 4 5 6 7 5 6 5 5 6 5 5 5 6 6 10 10 11 9 10 11 11 10 10 11 11 11 11 10 12 10 11 10 10 12 9 10 11 10 11 11 10 75 . .. 53 72 . .. 54 71 . .. 54 74 . .. 53 73 . .. 55 75 . .. 55 74 . .. 54 75 . .. 57 72 . .. 53 72 . .. 53 70 . .. 53 76 . .. 56 72 . .. 54 76 . .. 57 72 . .. 53 75 . . 54 70 . .. 55 72 . . 55 80 . . 56 77 . 56 74 . . 56 79 . . 58 77 . . 60 76 . . 57 74 . . 55 72 . . 54 69 . . 52 2 (trace) 2 (trace) 1 m m i i m i m m m m m m m m m m m m PECULIAKITIES OF PLAICE FKOM DIFFERENT FISHING GROUNDS. 353 Locality : Off South Coast of Iceland. Specimen in spirit, collected by Mr. Holt. Length, Ht. of Length Can. cm. Body, of Head. Fed. 60-6 ... 40 ... 21 ... 6 Male. Cau. Tubercles. Gill D. A. Fin. Kakers. Rays. Rays. 19 ... 5 ... 9 ... 7'2 ... 54 Ciliated Cil. Matu- Rays. Body. rity. . 47 ... 5 ... — Locality : Fisher Bank, North Sea. Specimen in spirit, collected by Mr. Holt. Length, Ht. of Length Cau. cm. Body, of Head. Fed. 49-1 ... 37 ... 23 ... 6 Male. Can. Tubercles. Gill D. A. Ciliated Cil. Matu Fin. Rakers. Rays. Rays. Rays. Body. rity. 17 ... 5 ... 11 .. . 74 . .. 55 .. 51 .. . 5 . — Locality : Baltic Sea. Specimens in spirit, sent to Mr. Holt from Hamburg, probably caught near Kiel. Males. Length, Ht. of Length Cau. Can. Tubercle.". Gill D. A. Ciliated Cil. Matu- cm. Body. of Head . Fed. Fin. Rakers. Rays. Rays. liays. Body, rity 23-5 .. 36 . .. 23 .. 6 . .. 20 ...4 (ii.it) 9 .. 64 . .. 47 . .. 50 .. 4 ... — 23-8 . .. 40 . .. 23 .. 7 19 .. 5 . 9 .. 70 . .. 54 . .. 50 .. 5 ... — 24-1 . .. 37 . .. 23 .. 6 . . 21 .. 5 .. . 10 .. 69 . .. 52 . .. 55 .. 5 ... — 24-2 . .. 38 .. 23 .. 5 . . 21 ..5(n«tt.. . 9 .. 69 . .. 52 . .. 49 .. 5 ... — 25-3 . .. 38 . .. 22 .. 7 . . 21 .. 5 .. . 11 .. 65 . .. 48 . .. 29 .. 5 ... — 29-4 . .. 38 . .. 23 .. 7 . . 19 .. 4 .. . 10 .. 73 . .. 53 . .. 44 .. 5 ... — Females. 23-4 . . 38 .. 25 . .. 6 . .. 21 . . 5 . . 10 . . 63 .. 48 . . — . .. — . m 25-2 . . 39 .. 25 . .. 6 . . 22 . . 6 . 9 . . 70 .. 51 . . — . .. — . . ra 26-8 . . 39 .. 23 . .. 6 . . 20 . . 6 . . 11 . . 67 .. 54 . . — . .. — . . m 30-4 . . 37 .. 22 . . 6 . . 20 . . 6 , 9 . . 70 .. 55 . — . .. — . m 31-5 . . 41 .. 23 . . 6 . . 17 . . 5 . . 9 . . 75 .. 54 . — .. — . m 354 PECULIAKillE« OF PLAICE FROM DIFFERENT FlSIllMi GUuUNDS. SPECIMENS IX THE BRITISH MUSEUM COLLECTION. Variety of Pleuronedes platessa. Collected liy U.S. Fishery steamer Alhalross, at Herendeeii Bay, Alaska. Length, Ht. of Length Can. cm. Body, of Head. I'ed. 23-3 ... 42 ... 24 ... 6 Can. Tubercles. Gill D. A. Fiu. Rakers. Rays. Rays. 18 ... 5 ... — ... 70 ... 51 Ciliated Cil. Matu- Hays. IJody. rity. . 40 ... 0 ...(?i Varieties of Pleuronedes glacialis. Collected by U.S. Fishery steamer in Nushagak River, Alaska. 18-3 .. . 39 . ,. 23 . .. 9 . .. 16 .. .. 0 ... - - ... 55 . .. 41 . . . many . . . 5 . .. $i 171 .. ? . 24 . .. 8 . .. 16 .. . 0 ... - - ... 59 . .. 40 . ,. many .. . 4 . ..$i 18-3 39 Collected at Kotzebue Sound, Alaska. 23 ... 9 ... 16 ... 0 ... — ... 53 ... 39 ... 34 ... 5 ... $ m Varieties of Pleuronedes flesus. PL Italicus, Giinther ; imsser, Bonaparte. Specimens from Dalmatia. 13-7 . .. 37 ., ,. 22 . .. 7 . .. 18 ., ,. 2 .. . — . .. 58 . .. 42 ., ,. 0 . .. — . .. i 19-6 . .. 36 .. . 23 ., ,. 8 ., ,. 18 .. . 2 .. . — . .. 62 ., .. 42 .. 22 .. — . ..$i 20-1 . .. 37 ., ,. 23 . .. 8 . .. 18 ., ,. 2 .. — . .. 59 . .. 42 . .. 1 . .. ? PI. 'luscus, Pallas. Specimens from the Bosphorus. 28-3 . .. 42 .. ,. 22 . .. 7 . .. 18 ., ,. 2 .. . — . .. 60 . .. 43 . .. few ... - — ... $ m 28-3 . .. 37 ., ,. 22 . ,. 8 . .. 18 .. 2 . — . .. 56 . .. 41 . .. 28 ... - ... f^- #1;:^ Fi-. 4. li;-. .). THE OYSTER CULTURE OF THE ANCIENT ROMANS. 365 EXPLANATION OF PLATE I. Illustratiiuj Mr. R. T. GUntha's Paper on '^ The Oyster Culture of the Ancient Romans." Fig. 1. — OSTRIARIA beneath a bridge connecting the upper stories of two buiklings, similar to those represented in Fig. 2. One oyster is shown attached to each rope. To the right is a pier. Piombino vase. After De Rossi. Fig. 2. — OSTRIARIA and buildings near Baiae. Three oysters are attached to each rope. The ropes hang from a framework, as in Fig. 1. Borgiano vase. After De Rossi. Fig. 3. — Glass vase. Museo Borgiano. Fig. 4. — Oyster culture in Lucrine Lake. The man in the punt is shown holding up a rope of oysters (cf. Fig. 6), which he has just detached from the cross -ropes between the posts. Fig. 5. — View of Lake Fusaro, showing the upper ends of the posts used to support the oysters. On the left is the steep profile of the Monte di Piocida. The volcanic peak in the distance is Mont' Epomeo in Ischia. Fig. 6. — Rojje with oysters (pei-golaro), showing mode of insertion between the strands. I am indebted to Mr. C. Ilallett for this sketch from my photograph. [ 36G ] Recent Reports of Fishery Authorities. The Scottish Report for 1895. Fourteenth Annual Report of the Fishery Board for Scotland, being for the year 1895. Edinburgh, 1896. The Effect of the Closure of Inshore Areas upon the Size and Abundance of the Food -Fishes which they contain. — In the Eeport under consideration Dr. T. Wemyss Fulton, the Scientific Superintendent of the Scottish Fishery Board, publishes an important Review of the Trawling Experiments of tlie Garland in the Firth of Forth and St. Andrews Bay in the years 1886-1895. As is well known, these areas have been closed to trawlers during the ten years under consideration. The Board's steamboat Garland has from time to time made experimental hauls with a 25 ft. beam-trawl along certain fixed lines within the areas, the fish captured being measured and recorded, and the results of the experiments published from year to year in the lieports. After ten years' work, Dr. Fulton now gives a general review of the whole investigation, and indicates the conclusions to which, in his opinion, the results of the experiments seem to point. The views expressed are of so much importance that we prefer to sive the account of the manner in which the observations were recorded, and the summary and general conclusions, in Dr. Fulton's own words : — " In conducting the trawling experiments the aim has been, as far as possible, to trawl over each station at intervals of about a month, and to keep careful records of each haul, and of the conditions under which it was made. The regular trawling work has been done only in the day- time .... The observations at each station comprised (1) the date and hour of the haul and its duration ; (2) the temperature of the air and of the water at surface and bottom; (3) the density of the water at surface and bottom ; (4) the transparency of the water, as indicated by the depth at which an enamelled disc just ceased to be visible ; (5) the direction and force of the wind, the state of the tide, the condition of the weather and of the sea in regard to surface disturbance, and EECKNT REPORTS OF FISHERY AUTHORITIES. 367 the height of the barometer — the temperature, density, and other observations being taken at the beginning and at the end of the trawling; that is to say, at each end of the station; (6) the nature of the pelagic fauna, collections being made by means of tow-nets at surface and bottom, and occasionally at intermediate depths ; (7) the number of each species of fish, and the length of each individual caught in the trawl ; (8) the nature and relative abundance of the invertebrate organisms found in the trawl, which form a large portion of the food of the bottom-living fishes." "Summary and Conclusions. " Wliile the trawling experiments of the Garland in the Firth of Forth and St. Andrews Bay have been productive of a great body of scientific knowledge respecting the reproduction, spawning areas, and tlie natural history generally of the food-fishes, the immediate practical object in view was to ascertain the influence which the cessation of beam-trawling would have upon the relative abundance of the food-fishes within the closed areas. The method adopted for this purpose has been already explained, namely, the periodic examination of certain selected stations in each of the areas, the enumeration and measurement of the fishes caught, and the comparison of the statistics thus obtained from month to month and year to year. A question which confronts one at the outset is whether the period during which the experiments have been carried on is sufficiently long to enable definite conclusions to bo formulated with certainty. It is evident, on the one hand, that if trustworthy conclusions in regard to the influence of beam-trawling can be drawn from the ten years' experiments in the Firth of Forth and St. Andrews Bay, it is un- necessary that they should be continued there. On the other hand, it would be obviously unwise to terminate them until definite conclusions are obtained, since so much depends upon them. " The problem is complex, inasmuch as the natural causes, which are of course by far the most important in producing fluctuations in the abundance of the food-fishes in any given area, are very variable and very obscure. There is in the first place the group of physical influences, such as the weather, storms, currents, and temperature, acting directly upon the fishes themselves at all stages of their life, from the floating egg onward to the adult condition, and upon the organisms upon which they feed ; and in the second place, a group of biological causes, such as variations in reproductive activity, migrations from the closed area to the outer waters, and vice versa, and the presence, or absence, of other fishes upon which particular species feed, e.g., the herring. For example, it was discovered by the fine-meshed nets of 368 RECENT REPORTS OF FISHERY AUTHORITIES. the Garland that in the autumn of 1889 a vast shoal of young whiting — computed after careful observations to number over 200,000,000 — • was present in the Firth of Forth. They were too small to be caught that year in the ordinary net used in the trawling experiments, and the average for that year was not large. But in 1890 the average number rose in the closed waters of the Forth from lo'G to 56'9, and in the open waters from 19'9 to 121"G; and the fishermen in the district caught very nearly double the quantity of whitings that they did in 1889. This increase in the abundance of whitings was local, and may have been due to a combination of causes. Another example was the sudden and extraordinary abundance of small haddocks all along the east coast of Scotland in 1893. In the Firth of Forth the average sprang up from 221 to 118-8 in the closed waters (over 1000 being sometimes taken in a haul), and in the open waters from 42'4 to 176'3 ; and in the closed waters of St. Andrews Bay the average rose from I'O to 23'8, and in the open area from 8*8 to 43"8. " These instances will suffice to show how sudden and marked the natural fluctuations may be, and how they tend to obscure the influence of a minor though constant factor, such as a mode of fishing. The answer to the question as to how long it is necessary to continue the observations in the Firth of Forth and St. Andrews Bay depends to a large extent upon the continuity of the results underlying the varia- tions, as determined by a comparison of the averages in the first and second parts of the period during which they have been carried on. From the statistical analysis given in the foregoing pages, and sum- marised below, it appears to be fairly well proved that there has been a diminution of the more important flat-fishes in the closed waters, instead of an increase, as was anticipated ; and that this may probably be traced to the influence of beam-trawling in the open waters where the fishes spawn; but with regard to round-fishes, which are more numerous and migratory, the same conclusion cannot at present be drawn. In my opinion, after full consideration of the question, the best course is in the meantime to suspend the trawling experiments in the Firth of Forth and St. Andrews Bay, and to carry them on systematic- ally in the Firth of Clyde and the Moray Firth. Both of these areas contain within the closed limits extensive spawning grounds (which are absent from the Firth of Forth and St, Andrews Bay) that are fre- quented by successive shoals of the food-fishes at the spawning time ; and it is of great importance to ascertain the effect of the protection of these spawning places. "The statistics of the ten years' observations in the Firth of Forth and St. Andrews Bay point to the following conclusions : — " 1. No very marked change has taken place in the abundance of the RECENT KEPORTS OF FISHERY AUTHORITIES. 369 food-fishes generally withia the closed or open waters since the prohi- bition of trawling. The average number of the food-fishes (taken together) caught in each haul of the net in the years 1886-1890 was 2426 in the closed waters of the Forth, and 160-9 in the open waters; in the closed waters of St. Andrews Bay the average was 290*2, and in the open waters 1904. In the five years 1891-1895, the general averages were 252"8 for the closed area of the Forth, and 1717 in the open area; for the closed area of St. Andrews Bay the average was 184"o, and for the open area 182-7. There was thus a decrease in both areas of St. Andrews Bay, and an increase in both areas of the Forth. " 2. Among round-fishes, cod increased in numbers in all the areas, closed and open. Haddocks increased in the closed and open areas of the Forth, and in the open waters of St. Andrews Bay, and decreased in the closed waters of Sfc. Andrews Bay. Whitings decreased in abundance in all the areas, and gurnards increased in the closed waters of the Forth, and decreased in the other three areas. " 3. Flat-fishes, taking the different kinds together, increased in the open waters of St. Andrews Bay, and decreased in all the other areas. Plaice decreased in all the areas to the extent of 8-7 fishes per haul of the net in the closed waters of the Firth of Forth, and no less than 74'9 fishes per haul in the closed waters of St. Andrews Bay ; in the open waters of St. Andrews Bay the decrease was 23'1 fishes per haul, and in the open waters of the Forth, where they are scarcer, 0'6 per haul. Lemon soles, in like manner, diminished in abundance in all the areas — to the extent of 8 '4 fishes per haul of the net in the closed area of the Firth. In the other areas, where they are much scarcer, the decrease was less striking. These are the most important and valuable of the flat-fishes obtained : turbot and brill were not caught in sufficient numbers to enable an average to be usefully calculated. On the other hand, the common and abundant dabs, commercially of little importance, increased rather than diminished in numbers. The common dab increased in the closed area of the Forth by 8 "9 fishes per haul, and in the open area of St. Andrews Bay by 29"3 fishes per haul ; they decreased in the closed area of St. Andrews Bay by 20"3 fishes pei haul, and in the open waters of the Forth by 2"1 per haul. The long rough dab increased in all the areas, except in the closed area of St. Andrews Bay, where they are very scarce, the decrease there being 0*5 per haul. In the closed waters of the Forth their increase amounted to 62 fishes per haul, and in the open waters to 4*9 per haul ; in the open waters of St. Andrews Bay the increase was 3"3 per haul. '"These facts in connection with the relative abundance of flat-fishes are of importance. On the face of it, it appears strange that there 870 RECENT KEPORTS OF FISHERY AUTHORITIES. should liave beeu a fairly continuous decrease in the numbers of plaice and lemon soles in the closed waters throughout the period. Fluctua- tions have undoubtedly occurred from year to year, but, as has been frequently pointed out in previous reports, the statistics show a fairly steady falling off in the abundance of the species ; and of such a character, when compared with the variations of other species, as to preclude the idea that it is due to the operation of natural causes. It was naturally expected that the prohibition of the use of the beam- trawl in the Firth of Forth and !St. Andrews Bay would be followed by an increase and not by a decrease in the numbers of these species within the closed area, because the beam-trawl is the most effective fishing instrument by which they are captured, and its interdiction was equivalent to the removal probably of their greatest enemy.* " But such has not been the case. Before dealing with the probable cause of the falling off among plaice and lemon soles attention may be directed to the increase in the numbers of common dabs and long rough dabs, which may be said to have taken the place to some extent in the closed waters of the more valuable flat-lishes. Takimr the figures for the closed area of the Firth of Forth as the result of 574 hauls of the net during the ten years, the decrease in the number of plaice caught per haul of the net is found to have been 8"7, and of lemon soles 8-4, a decrease almost exactly counterbalanced by the increase in common dabs, which was 8 "9, and in long rough dabs, which was 6'2. This clearly indicates a change in the relative proportion of the flat-fishes in the area, from whatever cause arising. Now there are some important differences in this connection between the dabs on the one hand, and the plaice and the lemon soles on the other. The dabs become mature while still comparatively small, and escape in great numbers through the meshes of an ordinary trawl net, and they spawn to a large extent in the closed waters. Plaice and lemon soles, on the contrary, do not spa\vu within the closed waters, and immature individuals are caught in great numbers by the ordinary trawl net. Thus the size at which common dabs and long rough dabs become mature is about 5 inches — the males frequently at a smaller size— while plaice do not become * "The in'oportion of the fish lu'csent in a given area that may be captured by fishing apparatus is frei]ueiitly under-estimated. Of several tliousands of plaice, marked for future identification and retuined living to the closed waters, about 12 per cent, were subsequently recaptured and returned to me within 18 months — and mostly within a few montlis — of their liberation. Tliey were nearly all retaken iu the closed waters by hook ; and as tliere is no reason to suppose that the marked fish were more prone to seize the bait than the fish around them wliich hud not previously been captured, it may be assumed tliat at least 1 in 9 or 1 iu 10 of tlie jilaice living on au area fall victims to the hook of the fisherman. With the beam-trawl the jiroportion would have been very much greater. — Vide ' An Kxperinicntjd Investigation on the Migrations and Rate of Growth of the Food Fishes,' Part III., Eleventh Annual JRcjwrl, p. 176." KECENT REPORTS OF FISHERY AUTHORITIES. 371 mature until they are 13 or 14 inches long, and lemon soles not until they reach a length of 9 or 10 inches.* "The consequence of this difference in the length when sexual maturity is first reached in the two groups is that all adult plaice and lemon soles, and large numbers which have not yet reached maturity, which enter an ordinary trawl net, cannot escape through the meshes, and are captured : while large numbers of adult dabs of both species, and by far the greater proportion of the immature, do escape through the meshes of the net, and are therefore not caught. In other words, the ordinary beam-trawl is not anything like so destructive to dabs as to plaice and lemon soles. The special experiments made on the Garlaiid bring out this matter in a marked manner.f " Thus in 43 hauls of the Garland's ordinary net, having meshes in the cod-end of 1| inches from knot to knot, 2705 plaice of all sizes were retained in the net, and only 67 escaped through the meshes; among lemon soles 371 were retained, and 154 escaped; among common dabs 3367 were retained and 9892 escaped ; and among long rough dabs 506 were retained, and 2562 passed through the meshes. Of the 67 plaice which escaped, 59 were 7 inches or less in length, and only 8 above that size (8 inches); of the 154 lemon soles none were above 7 inches ; of the 9892 common dabs which found their way out of tlie net, 2086 were 6 inches or over — that is to say, of adult size — and 5426 were 5 inches in length, or about the size at which maturity is reached ; of the 2562 long rough dabs which escaped, 1238 were 5 inches or over. " The other point is also of importance, namely, the place where the fishes spawn ; and the information on this subject obtained by the Garland is of great value. :J; The plaice and the lemon sole spawn outside the territorial waters, and therefore beyond the limits of the closed areas. All the plaice and almost all the lemon soles in the Firth of Forth and St. Andrews Bay come in from the outer waters, their floating pelagic eggs, or their equally helpless larva?, being borne in by the currents ; or some may have migrated thither at a later stage. The abundance of these forms in the closed areas is therefore strictly and directly dependent on the outer seas. It is not the same with the dabs. They seem to spawn indifferently in the closed and in the open waters, although spawniug individuals are rather more numerous in the latter. • " Vide ' Observations on the Reproduction, Maturity, and Sexual Relations of the Food-Fishes,' Part III., Tenth Annual Ilcport, p. 232." t "Fide 'The Capture and Destruction of Immature Sea Fishes,' Part III., 'The Relation between the Size of the Mesh of Trawl Nets and the Fish Captured,' Pari III., Twelfth Annual lleport, p. 302." X "Vide 'The Spawning and Spawning-Places of Marine Food -Fishes,' Part III., Eifjhth Anniud Report, p. 257; also Part III., Tenth Annual Report, p. 235." 372 KECEKT KEPORTS Of FISHERY AUTHORITIES. All urea like the Firth of Forth is therefore, to a very large extent, iudepeudeiit of the outer seas so far as concerns its supply of dabs, it being in large measure self-productive. " The differences above described between the plaice and lemon soles and the dabs seem to furnish a reasonable explanation of their decrease and iucrease respectively. When beam-trawlers were prohibited from working in the Firth of Forth and St. Andrews Bay, they naturally concentrated their efforts in the free waters outside, and trawling operations there have very greatly increased since the Bye-laws were passed. The immediate consequence of the cessation of trawling in the Firth of Forth and St. Andrews Bay appears to have been an increase in the abundance of flat-fishes within the closed areas, as shown by the very high averages in the year 1887. The fact that this increase was not only not maintained, but that a progressive decrease in plaice and lemon soles occurred subsequently, indicates another influence, namely, excessive trawling on the offshore grounds where these fishes spawn. This would affect the abundance of the important flat-fishes, such as plaice and lemon soles, in two ways. By general overfishing, the numbers are decreased on the fishing-ground, as indicated by the averages for the open area ; and in the second place, by the removal of too great a proportion of the mature spawning fishes, the supply of floating eggs and larvpe to the inshore closed areas, and upon which they are dependent, is diminished below the normal, with the result that the supply of adults is also subsequently diminished. This appears to me to be the only feasible explanation of the facts stated, and it would indicate protection of the spawning areas as the proper course to be pursued. The protection of the immature fishes, which has been so strongly advocated by many authorities, will not, it can be safely said, be sufficient in the areas under consideration. This is clearly proved by the fact that the fish which, above all others, has the nurseries of its young located in the inshore waters is the plaice. The distribution of immature plaice is special in this respect, by far the largest number being got near the shore, and fewer and fewer the further from the shore.* In the Firth of Forth and St. Andrews Bay immature plaice have therefore been particularly well protected since 1886, and yet this is the species whose diminution is most marked. "The results of the trawling experiments hitherto conducted in the Firth of Forth and St. Andrews Bay point to two main conclusions of great importance for fishery regulations. One, which may be regarded as demonstrated, is that the mere closure of even large areas in tlie territorial waters, such as the Firth of Forth and St. Andrews • "Fide 'The Distribution of Immature Sea Fish and their Cajjture by various Modes of Fishing,' Part III., Eujhth Anniuil Report, p. 166." RECENT HEPORTS OF FISHERY AtJTHORlTlES. 373 Bay, which are destitute of spawning-grounds, will have little or no permanent effect in increasing the abundance of the important food- fishes, and especially the flat-fishes, within thera. The other, which, although highly probable, has not yet been actually demonstrated by experiment, is that protection of the offshore spawning-grounds for certain periods is the most likely method of increasing the abundance of the fishes in the inshore waters. In completion of the experiments in the Firth of Forth and St. Andrews Bay, it would be desirable if a part at least of the offshore waters from which the supplies of floating eggs and larva3 to these areas are drawn were closed duriug the spawning season. It would then be possible to ascertain, by comparison of the results with those already obtained, to what extent protection of spawning areas will lead to an increase in the fish supply within the territorial waters. The extent and situation of the offshore areas which stand in this direct and close relationship to a given portion of the territorial waters have not yet been satisfactorily determined ; but experiments are now being made to clear up this point." The Dunbar Hatchery. — Mr. Harald Dannevig gives an account of the working of the Marine Hatchery at Dunbar during 1895. Three species, the turbot, the lemon sole, and the plaice, were dealt with. As in previous years, the great difficulty has been in obtaining a sufficient supply of spawning fish in a healthy condition. In the case of the turbot, the supply consisted of thirty- four fish, which had to be brought to Dunbar from Girvan on the west coast, and no natural spawning took place. Eggs were, however, pressed from the ripe fish and successfully fertilised. About 3,800,000 larval turbot were hatched and distributed in the neighbourhood of Dunbar. Less difficulty was experienced with the lemon soles, which, when they reached the hatchery uninjured, spawned naturally. About 4,480,000 fertilised eggs were obtained duriug the season from a stock of sixty-eight healthy fish, and from these 4,145,000 larvae were successfully hatched out and distributed in the local waters and westwards as far as the Bass Hock, the loss of eggs during development being thus only 7"5 per cent. In the case of the plaice again it was found necessary, in order to ensure a good supply of eggs, to press them from the ripe females and artificially fertilise. In this way 14,970,000 eggs were obtained, and from them 11,350,000 larvfc were hatched. About 7,000,000 of these larva) were distributed in the North Sea in the neighbourhood of Dunbar. It was considered advisable, however, to test, if possible, the effect produced by thus placing large numbers of newly-hatched larviu in the sea, and in order to do this it was determined to attempt to place them in a more or less confined area. For this purpose Loch 374 RECENT REPORTS OF FISHERY AUTHORITIES. Fyne, on the west coast of Scotland, was selected, 4,000,000 larvre being conveyed there by train in four separate consignments. The transport appears to have been fairly successful, though on two occasions the larvfe are reported as showing a certain amount of weakness when put out in the loch. This difficulty will no doubt be got over after further experience in the best methods of transport lias been gained. The Oyster Beds of the Firth of Forth. — Dr. Fulton contributes a second valuable paper to the Report, in which he discusses the past and present condition of the oyster beds in the Firth of Forth. The causes of the exhaustion of the beds are considered, and various suggestions made as to the measures which should be adopted in order to make them again productive. Dr. Fulton considers that the present condition of the beds is entirely due to improper fishing and the neglect of efficient regulations ; and further, that there is still a chance of restoring at least a part of them by judicious aid. The measures recommended are (1) the laying down of a stock of oysters to furnish spat ; (2) the supply of suitable cultch for the reception of the spat ; and (3) keeping the ground clean and as free as possible from enemies. As no oysters are so suitable for any locality as the oysters which naturally live there or in the neighbourhood, by far the best means of obtaining the breeding stock would be to collect the oysters at present scattered over the beds, and to lay them down in one or more selected places. This might be done by purchasing from the fishermen the oysters taken when dredging for mussels and clams. The oysters thus obtained for breeding purposes might be supplemented by others obtained elsewhere. In order to obtain a supply of clean cultch for the spat to settle upon, mussel and clam shells might be collected from the various villages and exposed to the sun and air until the spatting time, when they should be strewn on the various grounds. Dr. Fulton calculates that an expenditure of £600 per annum for five or six years would be sufficient to carry out the scheme he recommends, including the protection of the areas where the breeding stock was deposited. On the other hand, the fishermen on the south side of the Firth of Forth have lost during the last twenty years fully £150,000 by the exhaustion of the beds, to say nothing of the loss to the citizens. Hate of Growth of the Herring. — Mr. Masterman's paper, "On the Eate of Growth of the Food-Fishes," deals with the rate of growth of the Herring at St. Andrews, and the author gives the following summary of his conclusions : — "The young larva, hatched at from 5 to 7 mm. (j2_ inch) in length, lives near the bottom till some 10 mm. (j*(y inch) is attained by a rapid increase in length. The attenuated post-larval herring then migrates upwards through the mid- water to the surface, the mid-water stage lasting from about 10 mm. (i^ inch) to RECENT REPORTS OF FISHERY AUTHORlTIhS. 375 23-24 mm. (j^j. inch), and the surface stage from 24 mm. to 27-28 mm. (about 1 inch), when a movement shorewards takes place, and the littoral habit is acquired." The young herring of the spring-spawning remain near shore, chieily at the mouths of rivers, until mid-winter, when the length of some 50 mm. (2 inches) has been reached. They are not found during the spring and summer, but recur in the same localities in the autumn with a length of about 80 mm. (3i inches), which is increased to 100 mm. (4 inches) by the end of the year. Other Papers. — Dr. J. H. i'ullartou contributes a memoir on the European Lobster, in which he deals chiefly with the breeding and development of that animal. His results agree in the main with those obtained by Ehrenbaum in Heligoland, a full account of which was given in this Journal, vol. iv. pp. 60-69. A series of figures is given, showing the external appearance of the embryos and larvse at various stages of development. . Amongst the other papers may be mentioned Professor M'Intosh's "Contributions to the Life- Histories and Development of the Food and other Fishes," and Mr. Thomas Scott's faunistic papers, dealing with the Firth of Forth, the inland waters of Scotland, and the inland waters of the Shetland Islands. The Danish Report. Report of the Danish Biological Station to the Home Department. V. 1804. By C. G. John Petersen, Ph.D., Copenhagen, 1896. The Eridal-dress of the Common Eel.*' — Dr. C. G. J. Petersen's paper — " The Common Eel {Angnilla vulgaris, Turtoyi) gets a particular breeding-dress before its emigration to the sea. The bearings of this fact on the classification and on the practical Eel-fisheries" — forms an important contribution to the solution of the mystery which lias surrounded the life-history of the eel, and serves to complete the brilliant observations of Professor Grassi, an account of which was given in this Journal two years ago by Mr. Cunningham. Three different kinds of eel have been recognised both by fishermen and naturalists. Thus Yarrel distinguishes three species, the sharp- nosed eel — silver eel of the fishermen — {Angnilla acutirostris), the broad-nosed eel — grig or frog-mouthed eel of fishermen — {Anguilla * On tliis subject compare also Professor G. B. Grassi, " The Rci>roduction and Aluta- niorphosis of the Common Eel (Anguilla vulfjaris)." Proceed. Roy. Soc. London, No. 303, Dcccmbei-, 1896. An accotmt of Grassi'sobsfM'vations is given by Cunningliam, "Tlie Larva of the Eel," Joura. Mar. Biol. Assoc, vol. ill. pp. 278-287. 376 RECENT llEPORTS OF FISHERY AUTHORITIES. latirostris), and the snig or yellow eel {Aiujuilla medioj'ostris). Later authors have, for the most part, regarded the three kinds as varieties of one species, Anguilla vulgaris. Gilnther, however, in his Catalogue of the Fishes in the British Museum, attempts to distinguish two species, A. vulgaris and A. latirostris, the latter being tlie frog-mouthed or broad-nosed eel of Yarrel. In the Eeport now under review Petersen regards the three so-called varieties as representing three stages in the development of one and the same animal, and his conclusions, based upon a large number of carefully-considered observations, appear to be well founded. Briefly stated the result arrived at is, that the yellow eels comprise both males and females, but are all young fish, which have not yet commenced to assume the bridal-dress of the adult, and in which the generative organs are little developed. The frog-mouthed eels are larger females still in the same conditions, whilst the silver eels comprise both males and females which have taken on the bridal-dress. The generative organs of the latter class are more fully developed, and the animals just on the point of migrating to the sea to spawn. The following more detailed account of the three kinds of eels is derived from that given by Petersen. Yellow Eels. — The yellow eels are generally of rather light colour, the back, for instance, being grey or brownish, often with a greenish shade, the sides pale yellow, and the belly either like the sides or of a pure white. They are found in both salt and fresh water, and are taken during the winter as well as in summer. The digestive organs are well developed, and the eels feed voraciously. The snout in front of the eyes is much flattened ; the eyes are small, the interorbital space being greater than the horizontal diameter of the eye — in larger specimens generally about double the size. Looked at vertically from above the eyes face upwards rather than sideways, and the corners of the mouth, with the lips, can be seen distinctly outside the eyes. The pectoral fins are light in colour and rounded posteriorly. The skin is thin, the scales are but slightly visible, and very little guanine, which gives the metallic, silvery look to the silver eels, is deposited. The lateral line and its branchings can be seen, but not very distinctly. The yellow eels comprise both males and females, but there are no good external characters to distinguish the sexes excepting size, the males being never longer than 48 cm. (19 inches), whilst the females can reach | to 1 metre (20 to 40 inches). The generative organs are but little developed in either sex, although they are sufficiently so to make it quite possible to distinguish males from females, without microscopic examination, in specimens 10 inches long and upwards. With the aid of the microscope the sexes may be distinguished by an examination of RECENT REPORTS OF FISHERY AUTHORITIES. 377 the reproductive organs in specimens down to 8 inches. Below this size the distinction is impossible. Froc;-mouthed Eels. — These are really the same as the yellow eels, excepting that they are much larger and are all females. They are large females, with ovaries as yet but little developed, and which have not commenced to take on the breeding-dress. Their bodies are long and lean, and they feed voraciously. The pectoral fins are light coloured and rounded behind. The heads appear large in proportion to the bodies, and possess the same characters as the heads of the yellow eels in a more exaggerated form. These large, lean fish appear in numbers at the beginning of summer, having probably been starving during the winter. They are caught in large numbers on hooks baited with fish, and their stomachs are often much dilated with food. Later in the year they become less frequent, having become fat and taken on the breeding-dress. Silver Eels. — These are yellow eels, which have assumed the breeding-dress, and are about to migrate to the sea to breed. The author has observed all transition stages between yellow and silver eels, and yellow eels with commencing metallic lustre kept in caufs he has frequently observed transformed in a few weeks into silver eels. Silver eels are all of large size, and comprise both males and females. No males have been found under 29 cm. (11|- inches) long, and they are rare at this size. The smallest female observed was 42 cm. (lOh inches) long, but these also are seldom seen so small. The bodies of the silver eels are plump and fat. The snout in front of the eyes, particularly in the males, is high and a little compressed, probably owing to the considerable development of the olfactory organs and an increase in the size of the eyes. When the head is looked at vertically from above, the eyes protrude beyond the lips, and face sideways or outwards rather than, as in the yellow eels, upwards. The eyes are also considerably larger than in yellow eels of the same length. This was proved both by measuring and weighing eyes from the two kinds. The colour of the back is dark, nearly black ; there are bronze streaks at the sides, and the ventral side is silver-white with a metallic lustre. The pectoral fins are dark coloured, even black, pointed behind, and longer in proportion to the head than those of the yellow eels, which are bright coloured and rounded. The skin of the body is thick and firm, the outlines of the scales distinct, and the lateral line, with its ramifications, easily seen. The silver eels do not feed much, and are seldom caught on hooks. The digestive organs are comparatively much smaller than those of yellow eels, as the author has proved by weighing them, whilst the 378 RECENT REPORTS OF FISHERY AUTHORITIES. reproductive organs of both males and females are in a much more advanced condition. The silver eels emigrate from the rivers to the sea in summer and autumn, and are caught in traps, the mouths of which are set to face up-stream. In winter all the eels caught are yellow eels. Petersen points out that, in consequence of the above relations between the different kinds of eels in closed waters or rivers, where all the silver eels can be caught as they emigrate to the sea, the yellow eels should not be taken at other times, but allowed to remain until they become silver eels of larger size and greater value. In confirmation of Petersen's views, and in order to complete the history, we may add the following quotation from Grassi's most recent paper in the Frocccdmgs of the Royal Society*: — " In another point my researches have yielded a very interesting result. As a result of the observations of Petersen, we know now that the common eel develops a bridal coloration or ' mating habit,' which is chiefly characterised by the silver pigment without trace of yellow, and by the more or less black colour of the pectoral fin, and finally by the large eyes. Petersen inferred that this was the bridal coloration from the circumstance that the individuals exhibiting it had the genital organs largely developed, had ceased to take nourishment, and were migrating to the sea. Here Petersen's observations cease and mine begin. The same currents at Messina, which bring us the Leptocephali, bring us also many specimens of the common eel, all of which exhibit the silver coloration. Not a few of them present the characters described by Petersen in an exaggerated condition ; that is to say, the eyes are larger and nearly round instead of elliptical, whilst the pectoral fins are of an intense black. It is worth noting that in a certain number of them the anterior margin of the gill-slit is intensely black, a character which I have never observed in eels which had not yet migrated to the sea, and which is wanting in the figures and in the originals sent to me by Petersen himself. Undoubtedly the most important of these changes is that of the increase of the diameter of the eye, because it finds its physiological explanation in the circumstance that the eel matures in the depths of the sea. That, as a matter of fact, eels dredged from the bottom of the sea have larger eyes than one ever finds in fresh- water eels, I have proved by many comparative measurements, made between eels dredged from the sea-bottom and others which had not yet passed into the deep waters of the sea. Thus, for instance, in a male eel taken from the Messina currents, and having a total length of 34i cm., * Proceedings Hoy. Soc, vol. Ix. No. 363. Sec also Quart. Journ. Micr. Set., New Series, vol. xxxix. part 3. HECENT KEPORTS OF FISHERY AUTIIOHITIES. 379 the eye had a diameter, both vertical and transversal, of 9 mm. ; and in another eel of 33^ cm. the same measurement was recorded. In a female eel, derived from the same source and purchased in the market, whose length was 48i cm., the vertical diameter of the eye was 10 mm., and the transversal diameter rather more than 10 mm. These are not the greatest dimensions which I observed, and I conclude from these facts that the bridal-habit described by Petersen was not quite completed in his specimens, and that it becomes so only in the sea and at a great depth. In relation to these observations of mine stands the fact that the genital organs in the eel taken in the Messina currents are sometimes more developed than in eels which have not yet entered the deep water. Thus it has happened that male individuals have occurred, showing in the testes here and there knots of spermatozoa. These spermatozoa are similar to those of the Conger vulgaris, and must be considered as ripe. As is well known, so advanced a stage of sexual maturity has never before been observed in the common eel. This appears to be due to the fact that the males hitherto examined had not yet migrated into the deep water of the sea " To sum up, Anguilla vulgaris, the common eel, matures in the depths of the sea, where it acquires larger eyes than are ever observed in individuals which have not yet migrated to deep water, with the exception of the eels of the Eoman cloacie. The abysses of the sea are the spawning places of the common eel : its eggs float in the sea water. In developing from the egg, it undergoes a metamorphosis, that is to say, passes through a larval form denominated Leptoccphalus brcvirostris. What length of time this development requires is very diilicult to establish. So far we have only the following data : — Inrst, Anguilla vulgaris migrates to the sea from the month of October to the month of January; second, the currents, such as those of Messina, throw up from the abysses of the sea specimens which, from the commencement of November to the end of July, are observed to be more advanced in development than at other times, but not yet arrived at total maturity ; third, eggs, which according to every probability belong to the common eel, are found in the sea from the month of August to that of January inclusive ; fourth, the Lq)tocc2)halus brcvirostris abounds from February to September. As to the other months, we are in some uncertainty, because during them our only natural lisherman, the OrUiagoriscus mala, appears very rarely ; lifth, I am inclined to believe that the elvers ascending our rivers are already one year old, and I have observed that in an aquarium specimens of L. brcvirostris can transform themselves into young elvers iu one month's time." NEW SERIES. — VOL. IV. NO. 4. ^ D 380 RECENT REPOKTS OF FISIIEKY AUTHORITIES. Report of the Heligoland Biological Station. Wisscnschaftliche Mecresuntersuchungen heraiisgegeben von cler Kommission zur loissenschaftlichen Untcrsuchung der deutsclien Mccrc in Kid und dcr Biologischcn Anstalt auf Helgoland. Neue Folge, Zweiter Band. Heft 1, Abt. 1. 1896. The Eggs and Larvae of Fishes. — In the present communication, which is to be followed by others on the same subject, the author deals with the eggs and various larval stages of the flat-fishes found in the neiglibourhood of Heligoland, and with the eggs and larvae of the sprat. Excellent figures are given of stages in the larval development of the plaice, dab, flounder, turbot, brill, scald-back, sole, solenette, and of the sprat. Similar larva? of most of these species have already been figured by naturalists, but many intermediate stages are now shown for the first time, and it will be a great convenience to other workers to have such excellent figures of successive larvas thus broucrht toirether. The most important additions to our knowledge of the development of fishes which Dr. Ehrenbaum makes are the full accounts which he furnishes of the eggs and various larval stages of the scald-back (Arnogloss'iis laterna) and the solenette (Solea liUea), concerning which little was previously known. He has been able to show that in the case of the former species {Arnoglossus laterna) metamorphosis takes place in a similar way to that described by Steenstrup, Agassiz, and Pfeffer in the genus Flagusia; that is to say, the right eye, during metamorphosis, does not pass round the top of the head, as in the turbot, brill, etc., but appears to come through it. What really happens, however, in these cases is not that the eye actually comes througli the skull of the fish, but that the dorsal fin extends forwards to the snout, whilst the eyes are still on each side, and with the rotation of the head during metamorphosis the eye is carried round and pierces the fleshy portion of the base of this fin. [ 381 ] Microscopic Marine Organisms in the Service of Hydrography.* By Professor P. T. Cleve, University of Upsala. It has for a long time been known that the sea abounds iu microscopic organisms, both animal and vegetable. Among the former are entomostraca, infusoria, radiolarians, foraminifera, as well as larvce of mollusca, radiates, and bryozoa. Among the plant-life the mass consists of diatoms, cilioflagellates, flagellates, and certain unicellular chlorophyllaceous algfe. For these pelagic forms Prof. Hensen has proposed the name ijlanhton, which has been universally accepted. Some years ago I examined the samples of vegetable plankton collected by the Swedish Arctic expeditions, as w^ell as samples from various parts of the tropical seas, and I became convinced that certain parts of the oceans are characterised by different species. In the year 1893 I spent the summer at the west coast of Sweden, where I had the opportunity of examining the plankton at the marine biological station of Christineberg ; that is to say, in a fjord (loch) called GuUmarsfjord. I found that in the month of June the plankton consisted mainly of cilioflagellates, Ceratium tripos being the most common. During the last days of the month, however, the plankton changed. The water was from that time very rich in entomostraca, and the cilioflagellates became less abundant. At the same time the mackerel appeared iu the fjord. All my samples had been collected at the mouth of the fjord, where the water is not very deep. In the interior the fjord becomes deeper, as is the case also with the Scotch lochs, and I now wished to know the character of the plankton at different depths. What I hitherto had examined was the plankton of the current, called by the Swedish hydrographers the Baltic current, which in the spring and summer runs along the Scandinavian coast up to Bergen, in Norway. Below that surface current there exists, according to the Swedish hydrographers, water with lower temperature and greater salinity. In • Reprinted from Nature, vol. Iv. No. 1413. 382 MICROSCOPIC MARINE ORGANISMS IN HYDROGRAPHY. company with l*rof. G. Theel, and with the aid of his net, which could be closed and opened below the water, I made in July an attempt to get plankton from diiferent depths of the fjord. We found in the cold bottom - water very little plankton, some few specimens of a large Sagitta and of Calanus finmarchicus only. At about 30-40 metres the ciliollagellates (among them Ceratium divergens) were abundant, and on the surface the entomostraca. This examination was repeated during the first days of August, when I and Dr. Aurivillius had the oppor- tunity of accompanying Prof. Pettersson and Mr. G. Ekman on the hydrographical expedition which went out at the time. The result was the same as before ; but from the determination of the temperature and the salinity of the water, it became clear that the plankton had been collected in water differing in those respects, and consequently that the different strata of water were characterised by different amounts of plankton, and by different species. Samples of plankton were afterwards collected by the Swedish hydrographical expeditions at the same time as samples of water for physical and chemical research. The examination of the plankton was carried out by Dr. Aurivillius, who took charge of the animal plankton, and by myself, who undertook the vegetable. Having examined a large number of samples, I have lately found that the plankton of the Skagerack and Kattegat can be classed according to the prevailing species, and in this way 1 distinguished four types, namely : (1) Tripoa-'pkm'kton, (2) Didymus-planUon, (3) Tricho-planUon, and (4) Sira-planJcton. (1) The IVipos-planJitoJi is characterised by its scarcity in diatoms, and its abundance in cilioHagellates and entomostraca, which give to the spirit, in which the samples are preserved, an orange or yellow colour, all the other kinds of plankton colouring it more or less deep green. Among the entomostraca, according to the publications of Dr. Aurivillius, Faraccdanus parvus, Pseudocalanus elongatus, and Ecadne spinifera are the most abundant. Among the cilioflagellates Ceratium trii^os, with the variety macroceros, is the most common. C. divergens, C. furca, and C. fusus occur in less numbers. Diatoms are, as I have said, scarce, the most abundant being Coscinodiscus concinnus and Iihizosolenia gracillima. In winter and early spring the unicellular alga, Halosphaera viridis, is found in abundance. This kind of plankton characterises the water of the Pialtic current, and prevails in the summer in the Kattegat and Skagerack. The organisms consist chiefly of euryheline and eurythismic species, which can withstand the dilution of the Salter North Sea water by the slightly saline Baltic water. It seems very probable that this first type of plankton may by future researches be split up into different kinds. We may thus, perhaps, MICROSCOnC MARINE ORGANISMS IN HYDROGRAPHY. 383 distinguish one kind, characterised by Halu&phacra viridis, and occurring in the winter; another by lihizosolcnia gracillima, occurring in the summer ; one with Faracalanus parvus, and another with Pseudoccdanus elongatus, and so on. In all cases it seems to be certain that the water containing this first type is derived from the North Sea as well as from the Baltic. (2) The Didymus-2^lankton consists principally of diatoms, among which the most characteristic species are Cliaetoceros curvicetus, Oh. didymus, Ditylum BriijlitweUii, Rhizosolenia (data, and gracillima (the latter probably a residuum of Type 1), Skeletonema costatum and Thalassiothric Fraiienfddii (the latter probably common to Type 3). A silicoflagellate, Dictyocha speculum, occurs constantly, but not abundantly. The cilioflagellates, as well as the entomostraca, are scarce. This kind of plankton was predominant in the Skagerack and Kattegat in November, 1893, filling the fjords from the bottom to the surface. With the water containing this kind of plankton the herring arrived on the shores of Scandinavia. It seems to have been a very large bulk of water that at this time set in to the coast, as it drove away the whole of the summer water from bottom to surface. The diatoms of this type are not known from the Arctic Ocean or from the Northern Atlantic, but are well known from the coasts of France and Belgium and the English Channel, It seems thus to be beyond doubt that the water came from the southern North Sea, along the western coast of Denmark. The temperature, as well as the salinity, were found to be variable, but the plankton constant. In the Gullmarsfjord the water at the surface had a temperature of 7° C, at a depth of 30 m. nearly 12°, and at the bottom only 4° to 5°. The salinity amounted resjDectively to about 2G-27, 32 and 33 to 37 per thousand. This variation may be explained by the mixture of the water of the second type with the water previously present in the Kattegat. Probably the warmest water was the most pure water of Type 2, and corresponds to one of the kinds of water called by the Swedish hydrographers the bank-ivater. (3) The third type of plankton, the Tricho-plankton, is distinguished by its diatoms, especially the following species: Tlialassiosira loiujissima, lihizosolenia styliformis, Chaetoceros atlanticus (in a less degree also by Ch. horcalis and its variety Briylitioellii), and Biddulpliia muh'dcnsis. The first-named species occur abundantly and almost pure in the Northern Atlantic, south of Iceland ; the last-named I observed at Plymouth, West Scotland, and in the North Sea. This plankton may thus be considered a Northern Atlantic plankton. At the Scandinavian coast it seems to occur very rarely in a pure state ; in fact, I have seen 384 MICKOSCOPIC MARINE ORGANISMS IN HYDROGRAPHY. it only once, in February of this year, gathered at the bottom of the Christiania fjord (100 m.), where the temperature amounted to 7'5° C, and the salinity to o4-76 per thousand, the highest figures obtained by the hydrographical examinations of all the samples gathered in February, 1896. On the other hand, this plankton was frequently found mixed with the next type in samples collected at the time named. (4) The fourth type, the Sira-planldon, consists also mainlj'- of diatoms, but of different species, the most characteristic being Thal- assiosira AordensJcidldii and 27i. gravida, Chaeioceros graenlandicus, Ch. socialis, Gh. scolopendra, Ch. teres, Nitschia seriata, many of which belong to the Arctic seas, and some of which are new to science. Among the cilioflagellates the most abundant is a variety ardica of Ccraiium tripos, distinguished by Dr. Aurivillius as a constituent of the plankton of Baffin's Bay. There can be no doubt about the Arctic origin of this type. It occurred in the Skagerack and Kattegat this year in February and March, always more or less mixed with (3) and (1). In the Skagerack the water witli Types (3) and (4) was covered by a shallow layer of water with Type (1) ; but in the Kattegat it reached the surface. The admixture of Type (3) shows that the water on or before its arrival at the coast of Sweden was mixed with Atlantic water. The tem- perature and the salinity were found to vary greatly, owing to the admixture of the slightly saline Baltic water, at this time of the year very cold. I have observed the same type of water in some slides collected on the west coast of Scotland by Mr. George Murray, and sent to me by Mr. Grove. These samples had been gathered in the spring of 1888 — a year remarkable in England as an unusually cold one. As far as the plankton researches are advanced at present we may conclude that the surface-water around the Swedish coast consists in the summer of water from the North Sea mixed with Baltic water; that in the autumn its place is taken by water from the southern part of the North Sea ; and in the winter by water from the Northern Atlantic and the Arctic Ocean. Whether these changes occur regularly every year, or in certain years only, cannot be answered for the moment. Probably the last change is in correspondence, as Professor Petersen has recently suggested, with variations in the amount of water which the Gulf Stream carries past Iceland, westwards to Davis Strait, and eastwards to the Arctic Ocean. I think I have proved by the above that the examination of plankton is a matter of the greatest interest, not only in relation to hydrography, but also to meteorology and to fishery questions. There can be no doubt MICROSCOPIC MARINE ORGANISMS IN HYDROGRAPHY. 385 about the close connection between the state of the sea and the move- ments of the air, and the still obscure causes of the migration of fishes may be found to be intimately connected with the change of water containing different kinds of plankton. It is thus an important matter that the plankton of the North Sea should be thoroughly and systematically examined ; but for this, inter- national co-operation of all the nations around the North Sea is required. I imagine that a central station, under the direction of competent persons and provided with adequate accommodation, might be erected. Samples could be collected at certain intervals, and by the same kind of apparatus at different stations, and sent to the central one for examination. The details should be published every month, and the general results formulated in a way that would be useful to hydro- graphers, meteorologists, etc. The marine biological stations already in existence will probably be found willing for co-operation in such an undertaking ; but they will be able to collect plankton only near the shores, or at short distances from them. For getting samples from the open seas, the officers of the steamers crossing the North Sea and the Northern Atlantic might be found willing to assist, as the plankton may, as Dr. John Murray hinted to me, be procured by pumping water into a silk net. I recently tried this method whilst crossing from Edinburgh to Guttenburg. I fastened the net to the pump when the deck was being washed, and in this way I obtained sufficient plankton to prove that in the last days of July the North Sea was almost free from diatoms, and its plankton consisted mainly of cilioflagellates and entomostraca. [ 386 ] The Regulations of the Local Sea Fisheries Committees in England and Wales. By E, J. Allen, B.Sc, Director of the Plymouth Laboratory. The powers conferred on the Board of Trade, under the Sea Fisheries Eegulation Act of 1888, to create, upon the application of a County or Borough Council, a local Fisheries District, and to provide for the con- stitution of a Local Fisheries Committee for the regulation of the sea fisheries carried on within the district, have been requisitioned by the majority of the Councils of the maritime counties of England and Wales, and at the present time Fisheries Districts and Fisheries Committees are constituted around nearly the whole coast line, the Committees having jurisdiction over all fishing carried on within the three-mile limit. The only portion of coast still unprovided for is that which lies in the counties of Norfolk and Suffolk, between Happisburg and Dovercourt. The following is a list of the Fisheries Districts, with their boundaries, as they now exist : — Northumberland — from the boundary between England and Scot- land to the river Tyne. North-eastern — from the river Tyne to Donna Nook Beacon, on the coast of Lincolnshire. Eastern — from Donna Nook Beacon to Happisburg, on the coast of Norfolk. Between Happisburg in Norfolk and Dovercourt in Essex no Fisheries District has been established. Kent and Essex — from Dovercourt in Essex to Dungeness. Sussex — from Dungeness to Hayling Island. Southern— from Hayling Island to the western boundary of Dorset. REGULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. 387 Devon — Southern section, from eastern boundary of Devon to Eame Head in Cornwall. Northern section, from eastern to western boundary of Devon. Cornwall — from northern boundary of Cornwall to Eame Head. Glamorgan — from Nash Point to Worms Head. MiLFORD Haven — from Worms Head to Cemmaes Head in Pembroke. Western — from Cemmaes Head to the boundary between Carnarvon and Denbigh. Lancashire — from the boundary between Carnarvon and Denbigh to Haverigg Point in Lancashire. Cumberland — from Haverigg Point to Sark Foot. The powers of the Local Fisheries Committees, as extended by subsequent Acts (Fisheries Act, 1891, and Sea Fisheries [Shell Fish] Eegulation Act, 1894), include the making of bye-laws, subject to the approval of the Board of Trade, for the prohibition or regulation of any method of fishing for sea fish, for the establishment of close seasons for any sea fish, and for the regulation, protection, and development of fisheries for all kinds of shell fish (molluscs and crustaceans). Those powers have been largely exercised by the Committees, and the full text of all the bye-laws, which have received the sanction of the Board of Trade, is published in the Annual Reports of the Inspectors of Sea Fisheries for England and Wales. It may be useful to those interested in the protection of fisheries, more especially of inshore fisheries, to bring together under subject headings the regulations now in force, which vary considerably in the different districts around the coast. The regulations and restrictions apply to the sea within three miles of the coast, but not to those tidal estuaries which are under the jurisdiction of Boards of Salmon Conservators. Trawling with Steam Vessels. Trawling from vessels propelled otherwise than by sails or oars is entirely prohibited on the east coast of England, from Northumberland to the southern limit of the Eastern Fisheries District at Happisburg, on the coast of Norfolk. South of tliis point steam trawling is permitted along the east coast, and along the south coast of Sussex as far west- ward as Hayling Island, the mesh of the trawl, however, being regulated, as for sailing trawlers {see below), within the limits of the Kent and Essex and the Sussex Sea Fisheries Districts. Along the remainder of the south coast (Soutliern, Devon, and Cornwall Districts), and along the west coast of England and Wales, steam trawling is forbidden, excepting in the Milford Haven and Cumberland Districts. 388 REGULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. Trawling with Sailing Vessels. I. Trawling for Sea Fish, Northumberland District. — Trawling is prohibited. North-eastern District {Durham and Yorkshire). — Prohibited, excepting in Bridlington Bay, between February 1st and September 1st ; beam not to exceed 22 ft., and net to be raised and cleared at least every half-hour. Eastern District {Lincolnshire and north coast of Norfolk). — In northern portion of district,* the length of trawl beam must not exceed 22 ft., and the net must be raised and cleared not less than once in every hour. In southern portion of district i^ trawling is prohibited. Norfolk {east coast) and Suffolk. — No district, and therefore no restrictions. Kent and Essex District. — No trawl net may be used having more than 36 rows of knots to the linear yard. Sussex District. — No trawl net may be used having more than 30 rows of knots to the yard. Southern District {Rants and Dorset). — No restrictions. Devon District. — Trawling is prohibited in the bays on the south coast. On the north coast there are no restrictions. Cornwall District. — No restrictions. Glamorgan District (south coast of Wales). Mesh — not less than 1| inch gauge.J Circumference of net — not less than 100 meshes. Bectm — not greater than 40 feet, MiLFORD Haven District. — No restrictions. Western District {vjest coast of Wales). Mesh — not less than 1| inch gauge. Circumference of net — not less than 100 meshes. Beam — not greater than 45 feet. * "That portion of the said disti'ict whicli lies to the westward of a line drawn true north-east from the lightship known as tlie 'Lynn Well Light,' and to the northward of a straight line drawn from Gibraltar Point to Gore Point." t "That portion of the said district which lies between a line dra^\^l true north- nortli-east from the building standing upon Salthouse Beach, known as Randall's Folly (or the Sailor's Refuge), and a line drawn true north-east from Cromer Light- house." J " No person shall use any ti-awl net for taking sea fish, other than shrimps or pra\vns, having a mesh through which a square gauge of 1| inches measured across each side of tlie square, or G inches measured round the four sides, will not pass without pressure when the pet is wet." regulations of the local sea fisuekies committees. 389 Lancashire District. Mesh — not less than If inch gauge. [Except south of Formby Point, from July 1st to October 15th, mesh not less than IJ inch gauge may be used.] Circumference of net — With beam greater than 25 ft., circumference not less than 80 meshes. M » » 1^ it. „ „ „ 60 „ less „ 18 ft. „ „ „ 50 Beam — From January 1st to June 30th not to be greater than 30 feet. Vessel — From January 1st to June 30th not to be greater than 15 tons. Cumberland District. — No restrictions. II. Shrimps and Prawns. {All regulations applying to fishing for shrimps and prawns, whether hy trawling or other means, will he included under this heading.) Northumberland District. — Trawling prohibited. North-eastern District {Durham and Yorkshire to Donna Nook). — Beam not to exceed 8 feet in extreme length, and net to be raised and cleared at least once in every half-hour. Excepting : — (1) Between a straight line drawn true east from Castle Eden Dene, and a straight line drawn true north-east from Skinningrove Beck, a push net only may be used. (2) In the River Humber, between a straight line drawn from the entrance to St. Andrew's Dock to the northern extremity of tlie pier at New Holland, and a straight line drawn from Spurn Head Lighthouse to Donna Nook Beacon, between March 1st and October 31st, a trawl having a beam not exceeding 20 feet may be used, the net to he raised and cleared not less than once in every hour. Eastern District {Lincolnshire and north coast of Norfolk). — Length of trawl beam not to exceed 20 feet, and net not to have any pocket. Between December 1st and the last day of February no trawl net may be used for taking shrimps or prawns. East coast of Norfolk and Suffolk. — No district, and therefore no restrictions. Kent and Essex District. — No trawl net may be used having more than 108 rows of knots to the linear yard, except that for a length of 8 feet from the cod end there may be not more than 144 rows of knots to the yard. Sussex District. — No restrictions. Southern District {Hants and Dorset). — No restrictions. 390 PECULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. Devon Distkigt. — Trawling in the bays on the south coast is pro- liibited, witli the exception of trawling for shrimps or prawns in Plymouth Sound, with a beam not exceeding 8 feet in length, the net to be raised and cleared at least once every half-hour. Cornwall District, — No restrictions. Glamorgan District {south coast of Wales). Mesh — not less than | inch gauge. '^" Circumference of net — not less than 160 meshes. Beam — not greater than 40 feet. Milford Haven District. — No restrictions. Western District {ivest coast of Wales). Jllcsh — not less than | inch gauge. Circumference of net — not less than 160 meshes. Beam — not greater than 45 feet. Lancashire District. Mesh — not less than f inch gauge. Circumference of net — With beam greater than 20 ft., not less than 140 meshes. „ less „ 20 ft. „ ,, 120 „ Beam — not greater than 25 feet. Cumberland District. — No restrictions. Seining. In the North-eastern {Yorkshire and Lincolnshive), Western {ivest coast of Wales), and Lancashire Districts seining is prohibited, except- ing for the capture of sand-eels for bait in the North-eastern, and for herring, mackerel, and sparling in the Western and Lancashire Districts. In these cases also the net is regulated. In the Kent and Essex, Sussex, and Glamorgan Districts there are general mesh regulations for all nets used in the capture of sea fish, which would include seines. In other districts there are no regulations. The following regulations in the above-named districts may be mentioned : — North-eastern District. — A net may be used for taking sand-eels for bait, without a pocket; net 108 feet long and 12 feet deep, the central portion (12 ft. x 12 ft.) to be of closely- textured netting. • " No person shall use any net for taking shrimps or prawns having a mesh through which a square gauge of three-ciglitlis of an inch measured across each side of the square, or \\ inches measured round the four sides, will not pass without pressure when the net is wet." IlEGULATtONS OF THE LOCA.L SEA FISHKRlES COMMITTEES. 39l Kent and Essex District. — No net may be used for sea fish having more than 144 rows of knots to the yard. Sussex Distkict. — No seine or draft net may be used having more than 30 rows of knots to the yard, excepting when fishing for herring or mackerel, at any time, or for sprats during November, December, and January. Glamorgan District. — No net for sea fish (except sprats) may have a mesh less than 1 inch gauge. Western District {west coast of Wales). — No net for taking mackerel or herring may have mesh less than 1 inch gauge. Lancashire District. — Similar to Western District. Trammel, Stake, and Stop Nets. On the east coast the only bye-law relating to such nets is one made by the North-eastern Committee, whereby the use of trammel nets is prohibited in certain specified districts off the mouths of the principal rivers. On other parts of this coast the use of these nets is un- restricted. * On the south coast the only regulation applies to Chichester Harbour, where no stop nets may be set across the creeks within one hour before and after low water. On the west coast regulations exist in the Glamorgan, Western, and Lancashire Districts only, as follows : — Glamorgan District (soicth coast of Wales). — Stop nets for sprats must have a mesh not less than ^^ inch gauge. All stake and stop nets must be marked by buoys or poles, must be at least 10 yards from other stake nets or any fishing weir, and a pool 12 inches deep at low water must be kept for each net from May to October, at other times G inches deep, such pool to be three- quarters the size of the cage of the net, and not less than 36 square feet in area. Western District (ivest coast of Wales). — Trammel nets are pro- hibited. The position of stake nets must be marked by poles or buoys : the nets must not be nearer the centre of any stream than the edge of the stream at low water, and they must not be nearer than 50 yards to any other stake net. * In this connection particular notice should bo taken of the fact that we are not considering any bye-laws apjilicable to estuaries under the jurisdiction of Boards of Salmon Conservators. 392 REGULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. Lancashire District. — Trammel nets are prohibited. The regula- tions for stake nets are generally similar to those in force in the Western District, but the distance from other stake nets must be 150 yards. There is also a somewhat curious bye-law, which reads as follows : — " No person shall use, in fishing for mackerel or herring, any stake net except at the times and places at which, and in tlie manner in which, such nets have been heretofore commonly used for the capture of such fish respectively." Smelt or Sparling. In the Northumberland District there are no restrictions. In the North-eastern sparling nets may be used only between July 21st and March 21st, and mesh of net must not be less than six-tenths of an inch from knot to knot.^' In the Eastern District the nets must have not more than 24 knots to the foot, and they may not be used between April 1st and August 31st, In the Kent and Essex District the net must have not more than 72 rows of knots to the yard, and must not be more than 60 fathoms lomr. On the south coasts of England and Wales there are no restrictions. In the Western District {west coast of Wales) the mesh of the net must allow a square gauge with each side f inch long to pass through, whilst in Lancashire the fish may only be taken with seine or draft net, the size of mesh is increased to one inch, and the fish may not be caught between April 1st and October 31st. Crabs and Lobsters. In considering the regulations relating to crabs and lobsters, it must be borne in mind that the Eisheries (Oyster, Crab, and Lobster) Act, 1877, applies to the whole country, and makes it illegal to take, have in possession, sell or expose for sale, any edible crab which measures less than 4} inches across the broadest part of the back (except when for use as bait) ; or any edible crab carrying spawn attached to the tail ; or any edible crab which has recently cast its shell ; or any lobster which measures less than eight inches from the tip of the beak to the end of the tail, when spread out fiat. The Sea Fisheries Committees have made the following additional regulations in their respective districts : — Northumberland District. — No additional restrictions. * There is also a restriction as to the nature of the material of which the net is made. REGULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. 393 North-eastern District {Durham and Yorlshirc). — Crabs under 4^ inches not to be taken, even for bait. Lobsters under 9 inches long not to be taken. No lobsters or crabs to be taken between September 1st and January 31st of following year. Eastern District {Lincolnshire and north coast of Norfolk). — Crabs under 4| inches not to be taken, even for bait. No lobster carrying spawn, and no lobster which has recently cast its shell and is still soft, to be taken. From November 1st to June 30th no crabs known locally as " whitefooted " to be taken. Kent and Essex District. — No lobster carrying spawn to be taken. Sussex, Southern {Hants and Dorset), and Devon Districts. — No restrictions. Cornwall District. — No male edible crab less than 6 inches broad, „ female „ „ 5 „ may be taken. Glamorgan and Milford Districts. — No restrictions. No lobsters or crabs Western District {west coast of Wales) Lancashire District carrying spawn may be taken. No lobster less than 9 inches from beak to tail ; no edible crab less than 5 inches across broadest part of back, may be taken. Cumberland District. — No restrictions. Molluscs. Oysters. — In addition to the close times fixed by Act of Parliament, viz., for deep-sea oysters from 15th June to 4th August, and for all other oysters from 14th May to 4th August, the following are the regulations made by Local Fisheries Committees for their respective districts : — Kent and Essex District. — No cultch may be removed from an oyster ground. Southern District {Hants and Dorset). — No oysters may be taken from loth May to 30th September, and none may be taken at any time which will pass through a circular ring of 2 inches in internal diameter, except for stocking and breeding purposes. No cultch or other material for the reception of spat may be removed. .^ ^ , I No oysters may be taken which will pass through a circular ring 2^ inches in internal ', diameter. In other districts no additional restrictions have been made. Western District {west coast of Wales) Lancashire District 3!)4: KECiULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. Mussels. — Eastkijn District {Lincolnshire and north coast of Norfolk). — No mussels may be taken from INIay 1st to August 31st, nor any less than 2 inches in length at other times, except for stocking or breeding. No instrument may be used for taking mussels other than a rake not exceeding 18 inches broad, and with the teeth 1 inch apart. Glamorgan District {south coast of Wales). — No mussels may be taken in May, June, or July, except for stocking or breeding purposes. Mussels may be taken only {a) with a dredge, (h) by hand, or (c) with a rake not more than 8 feet wide, with the teeth 1 inch apart. Western District {ivest coast of Wales). — No mussels may be taken in May, June, July, or August, excepting for stocking, breeding, or bait (in one part of the district the prohibition extends also to April, September, and October), and none may be taken at any time less than 2] inches long. IMussels may be taken only {a) by hand, (h) with a rake not exceeding 3 feet wide, used from a boat, and when the bed is covered with at least 4 feet of water. Lancashire District. — No mussels may be taken in May, June, July, or August, and none at any time less than 2j inches long. jNIussels may be taken only (a) by hand, (IS) with a rake not exceeding 3 feet wide, used only from a boat, and when the bed is covered with at least 4 feet of water. In other districts no restrictions have been made. Cockles. — Eegulations are in force as follows : — Eastern District {Lincoln and north coast of Norfolk). — No instru- ment may be used for taking cockles except a rake not more than 12 inches long, with teeth 2 inch apart. Glamorgan District {south coast of Wales). — Cockles may only be taken by hand, or with a rake not more than 12 inches wide, with teeth I inch apart. Western District {luest coast of Wales). — Cockles may only be taken by hand, or with a rake not more than 12 inches wide, with teeth f inch apart. None may be taken which pass through an oblong gauge 4 inch wide and 2 inches long. REGULATIONS OF THE LOCAL SEA FISHERIES COMMITTEES. 395 Lancashire District. — No cockles may be taken which pass through an oblong gauge f inch broad and 2 inches long. They may be taken only («) by hand, (b) with a craam having not more than three teeth, (c) with other instruments under regulations which differ in different parts of the district.* Periwinkles. — In the Sussex District periwinkles may not be taken between April 1st and October 31st, and in the Southern District not between May 1st and August 31st. In other districts no regulations exist. Injurious Substances. Bye-laws prohibiting the deposit or discharge of any solid or liquid substance detrimental to sea fish or sea fishing are in force in the following districts : Kent and Essex, Sussex, Southern, Devon, and Lancashire. * Bye-law 20. No person shall fish for cockles except — {«) Bj' hand, or (b) AVith an instrument locally known as a craam, liaviuf,' not more than three teeth : ])rovided that — (1) Between the 1st day of November and the last day of February following, both inclusive, it shall be lawful to use an instrument locally known as the jumbo, not exceed- ing 4 feet 6 inches in length, 14 inches in width, and 1 inch in thickness, provided that such instrument shall be constructed entirely of wood, and shall not be dragged across the cockle beds or artificially weighted. (2) In that part of the district which lies to the southward of a line drawn true west from the mark known as " Kossall Landmark," near Fleetwood, it shall be lawful to use a rake not exceeding 12 inches in width. (3) In that part of the district which lies between a straight line drawn seawards through the north-west sea marks near Formby Point, and a line drawn true west from the western extremity of the southern training wall in the river Ribble or Gut Channel, it shall be lawful to use a spade. NEW SEKIES. — VOL. IV. NO. 4. 2 E [ 896 ] Contributions to Marine Bionomics. By Walter Garstang, M.A., Fellow and Lectuier of Liucoln College, Oxford. II. The Function of Antero-lateral Denticulations of the Carapace in Sand-burrowing Crabs. The antero-lateral margins of the carapace in many of the crabs of our own and of foreign coasts are beset with a row of teeth or spines, which vary in character and number in different species and genera. In the Oxyrhyncha (Spider-crabs) the whole surface of the carapace is generally studded with spines and stiff hairs of a peculiar character, but there is no general restriction of these processes of the carapace to the antero-lateral margins of the body. These crabs, moreover, do not adopt burrowing habits. Their armature of spines, tubercles, and hairs is employed, as is well known, for protective purposes : in some cases possibly as an actual defence against attack, in others {i.e., Eurynome as2Jera) as a means of protective resemblance to their surroundings; but in the great majority as mere pegs and hooks for the fixation of foreign bodies, such as alga^, hydroids, polyzoa, and ascidians, for purposes of concealment and disguise. In the Catometopa (Land-crabs, etc.) the carapace is usually smooth over its whole surface. These animals often burrow in sand, but for the most part their burrows are permanent subterranean tunnels and chambers. In the Cyclometopa, however — the group which includes most of our commoner British crabs — the back of the carapace is generally smooth, while the antero-lateral margins are in most forms conspicuously serrated. Most of these animals inhabit sandy or gravelly areas, and show a marked propensity towards burrowing habits. Their burrows are never* permanent channels or tunnels in the sand, but are mere temporary excavations, the sand, mud, or gravel being in actual contact with their bodies when imbedded. So far as I am aware no one has hitherto elucidated the remarkable constancy of antero-lateral serrations of the carapace in this group of crabs. I here present evidence which tends to show that the presence • i>ci/lla scrrala of the Natal coast appears to bo exceptioual in this resi^ect. (Kkauss, Die i)iUi(i/ricanischc7i Craslacccn, 1843, p. 12.) CONTKIBUTIONS TO MARINE BIONOMICS. 397 of conspicuous serrations on these margins of the carapace is func- tionally related to the exigencies of respiration when these animals are buried in sand. The marginal teeth are perhaps best developed and most conspicuous in crabs of the family Portuuidte (Swimming-crabs). As M. Alphonse Milne-Edwards has remarked : " Je ne connais aucun Portunien oii le bord latero-anterieur de la carapace soit entier ou arme d'epines arrondies ou de tubercules obtus." (1860, p. 202.) In Bathyncctcs longipcs there are five sharp -pointed teeth on each of the antero-lateral borders. These teeth increase in size regularly from before backwards, and the posterior tooth is a particularly stout and sharp structure. This crab is almost invariably an inhabitant of sandy areas {e.g., Mounts Bay in Cornwall) ; and the individual whose habits I am about to describe was also dredged upon a bottom of fine sand in the neighbourhood of the Eddystoue. In an aquarium containing sand the crab burrows into the sand just beneath the surface, leaving its eyes and the transverse slit-like aperture of the buccal frame exposed. The crab is actually imbedded up to the anterior edge of the external maxillipeds ; but it pushes away the sand in front of it by means of these appendages, and when at rest maintains these appendages in a sloping posture, so that they act as a quadrangular sieve-like fence in front of the buccal area. This happens both in very fine siliceous sand and in fine shell sand. The crab was not seen at any time to go completely beneath the surface, though I do not mean to imply by this that the crab never buries itself entirely. This may or may not be the case. Atclecydus heterodon is another sand-burrowing crab, whose habits I have studied for a much longer period ; and this crab has very diversified habits. It may remain partially imbedded at the surface of the sand, with its eyes and a broad funnel formed by the second antennae alone protruding, or it may disappear completely beneath the sand to a depth of several inches. When the crab {Bathynectes longiiies) is partially imbedded in the sand as above described, it may be noticed that the chelipeds are flexed and approximated to the under side of the antero-lateral regions of the carapace in an attitude precisely similar to that assumed by Atelecyclus heterodon, or the Oxystome crab Matuta, under the same conditions (1897). The position of the cheliped is such that the marginal teeth of the antero-lateral region of the carapace exactly overhang the slit-like orifice between the distal half of the cheliped (carpopodite and propodite) and the ptcrygostomial fold of the carapace. There is thus produced on each side of the crab, between cheliped and carapace, a channel similar to that which would be produced by the approximation in parallel planes of two fiat plates. This channel cummuuicatu.s below with the 2 E 2 398 CONTlilBUTlONS TO MARINE BIONOxMlCS. afTeroiit (iulialaut) aperture of the branchial chamber, which is situated at the base of the cheliped, and opens above through the notches between the teeth of the antero-lateral margins of the carapace. Since the back of the crab is covered with sand, it will readily be understood from this description that the antero-lateral teeth act as a coarse sieve or grating placed over the orilice of this accessory channel, and that they prevent the accidental intrusion of sand-particles into the lumen of the channel, a function which it was easy to determine that they efficiently discharged. The pair of accessory channels produced by the approximation of chelipeds to carapace I propose to term the " exostegal channels," owing to their situation on the external face of the branchiostegite. I show elsewhere (1897) that these channels probably represent in a generalised condition certain remarkable accessory afferent branchial canals of the Oxystome Brachyura, which attain their most specialised form and relations in Ehalia and other Leucosiida^. M. Alphonse Milne-Edwards (1861), p. 207) states that in the Portunidic "les mains ne sont jamais conformues de facon a pouvoir s'applit|uer exactement contre la region buccale, ainsi que cela se voit chez quelques autres Jjrachyures uageurs tels que les Calappes et les JMatutes." This contrast is quite in accordance with my view, that the afferent channel of the Portunida3 represents a primitive and relatively unspecialised type, from which the highly elaborate canals of the Oxystomata have been derived. That these accessory channels in the Portunidai are functionally connected with the respiratory process, was demonstrated by me in the case of Bathynectes longipes in the following manner : — When the crab was partially imbedded in sand with its face close to the front of a square glass acj^uarium, in the attitude already described it could be seen that beneath the body of the crab was a shallow ventral water-chamber, free from sand. The crab was resting with its body in an approximately horizontal plane. Sand-particles were supported over the orifice of the exostegal channel by the sieve-like row of teeth along the antero-lateral margins. Some water, coloured black with Indian ink, was then added by means of a pipette to the water lying above the slit between cheliped and carapace. The coloured water was at once sucked downwards between the grains of sand into the exostegal channel in waves which apparently corresponded to blows of the scaphognathite, and after a few seconds emerged in a black stream out of the afferent orifice of the branchial chamber situated in front of the mouth. It was quite clear that the water passed downwards through the exostegal channel to the afi'erent aperture at the base of the cheliped, and that it entered the branchial chamber by this aperture. CONTRIBUTIONS TO MARINE BIONOiMICS. 399 Similar observations and experiments were made upon numerous specimens of Atelecyclus heterodon, a crab belonging to an altogether different family. In this crab the antero-lateral margins are provided with as many as nine teeth, but the function of the teeth was found to be essentially similar. Owing to the different form of the body, and the different shape of the cheliped in the two crabs, the orifice of the channel between cheliped and carapace is of greater relative extent in Atelecyclus than in Bathynectcs ; but the length of the denticulated margin of the carapace was found to correspond precisely with the extent of the inhalant gap in each case. The following conclusions may be drawn, therefore, from these observations : — (1) Antero-lateral denticulations of the carapace in crabs may subserve a sieve-like function. (2) The extent of the denticulated area corresponds with the extent of the inhalant gap between the carapace and the cheliped when the latter appendage is approximated to it in the flexed position. It is also obvious that a new function must be ascribed to the chelipeds of sand - burrowing crabs provided with antero-lateral denticulations of the carapace. In such cases the chelipeds act as organs temporarily subservient to the respiratory process by providing a broad operculum to the exostegal channel. Attention may be recalled in this connection to the fact elucidated by Milne-Edwards in 1839, that iu the LeucosiidEe the floor of the afferent branchial channel is also provided b}' one of the appendages, in this case by the external maxillipeds. The relations of the afferent channel in the Leucosiidie to the external channel which I have now described iu the Cyclometopa are discussed by me in the paper to which reference has already been made (1897). The subservience of the chelipeds to the respiratory process enables me, moreover, to explain the function of a remarkable spine which in the Portuuid;e is almost universally present on the inner margin of the distal extremity of the carpal joint (carpopodite or wrist) of the cheliped. This carpal spine, though usually strong and conspicuous, presents various minor modifications of form which are employed by systematists in the discrimination of different species. The appearance of the spine in Bathynectcs longipes is represented by Bell and liisso. When the cheliped is fully extended the carpal spine projects freely from its anterior margin; but when the propodite is flexed towards the proximal part of the cheliped, it is arrested at a certain angle with the carpopodite by the carpal spine in question. If now the arm (meropodite) of the cheliped be approximated to the carapace in the position requisite for the completion of the exostegal canal, it 400 CONTRIBUTIONS TO MARINE r.IONOMICS. will be found that the angle at which the propodite has been arrested by the carpal spine is precisely the angle required for the proper apposition of cheliped to carapace in connection with the respiratory process. The carpal spine acts then as a stay or barrier to excessive flexion of the cheliped. Its function corresponds, therefore, in part to the function of such skeletal processes as the olecranon of the human ulna, which prevents excessive extension of the arm. Examination of a series of Portunids reveals that the variations in the form of the carpal spine in different species and genera are all functionally correlated with the different shapes and proportions of the carapace, and of the segments of the cheliped in the forms examined ; the result in all cases being that the shape of the carpal spine is adapted to ensure the due amount of flexion of the cheliped for the completion of the respiratory channel between cheliped and carapace. A similar function seems also to be discharged by the enlarged posterior spine of the antero-lateral margins in Balkyncctes longipes, since the car- popodite presses upwards against it during flexion of the cheliped. An examination of preserved specimens of the Mediterranean lAopa hasiata, and of the American Callinedes sapidus, in which the posterior spine is greatly elongated, seems to me to support this view, though I do not regard the evidence in this case as altogether unequivocal. A complete explanation of the enlargement of this posterior antero-lateral spine should also throw light on the great epibranchial spines of the Oxystome genus Matuta, and of the Lencosiid genera Iphis and Ixa. In the latter cases any relation between the development of the spines and the forma- tion of an inhalant chamber between cheliped and carapace is precluded by the known course of the afferent current in a gutter running between the pterygostomial plate and the exopodite of the third maxilliped. The phenomena presented by the respiratory processes of these sand- burrowing crabs throw light, as it seems to me, not only on the problem of the utility of a number of morphologically trivial, but systematically important features of Decapod Crustacea, but also on an altogether different problem, viz., the phylogeny of the r>rachyura Oxystomata. Crabs of the latter group are all characterised by their sand-burrowing habits of life. Similarity of habits often induces homoplastic changes of form in types genetically distinct; but there are certain significant details of structure in the different Oxystome types which appear to me to be only explicable on the view that these crabs are descended from ancestors in which the form of the body closely resembled that of sand- burrowing (Jyclonietopa in being provided with antero-lateral serrated margins, and in which the chelipeds were employed for the production of an extensive inhalant channel, completely roofed over by the pro- jecting teeth of the carapace. For a fuller discussion of this subject I must refer the reader to another paper to be published in the Quarterly Journal of Microscopical Science (1897). CONTRIBUTIONS TO MARINE BIONOMICS. 401 BIBLIOGRAPHY. Bell, T.—British Stalk-Eyed Crustacea, 1853. Garstang, W. — "On some Modifications of Structure subservient to Respiration in Decapod Crustacea whicli burrow in sand, with remarks on tlie Utility of Specific Characters in the genus Calappa, and the description of a new species of Albunea." Quart. Joxir. Micr. Sci, 1897. Milne-Edwards, A.— "Hist, des Crust. Podophth. Fossiles." Ann. Sci. Nat. (4) xiv. 1860. Milne-Edwards, H. — "Rech. sur le Mechanisnie de la Respiration chez les Crustaces." Ann. Sci. Nat. (2) xi. 1839. Fi(i. 1. Fig. 1. — Batlnjnectcs longiiKs. Dorsal view, showing the five teeth of the antero- lateral margins. The chelipeds are in a half-extended condition ; their pro- l^odites (hands) are shown resting against the carpal spines. The specimen shows an abnormality in the union of the two anterior marginal teeth of the right side to form a single bifid tooth. Fio. 2. Fig. 2. — Bathjnectes longipes. Dorsal view, showing the i)osition of the chelipeds after flexion of the wrists (carpopodites) as well as of the hands. The left cheliped is in the attitude assumed by the crab whun imbedded in sand ; the antero-lateral teeth are seen to form a sieve above the orifice of the inhalant gap between cheliped and carapace. On the right side the arm (meroi)odite) of the cheliped does not rest in its proper position beneath the enlarged po.-;terior marginal tooth ; hence the inliahmt gap is imperfectly formed, and its aperture is imperfectly covered by the marginal teeth. 402 CONTniBUTIONS TO MARINE BIONOMICS. III. The Systematic Features, Habits, and Respiratory Phenomena of Portumnus nasutus (Latreille). The crab whose habits I now describe has not previously been recorded as an inhabitant of Ihitish seas. I found two specimens, both male, imbedded in a patch of coarse shell sand on the south side of Drake's Island at low water, spring' tides: one on August 11th, 1896, and the other on the following day. 1. Nomenclature, My first impression on noticing this remarkable little crab was that I had an abnormal specimen of a young Carcinus macncis before me; but the possibility of such a leap from the normal as the frontal area of this specimen would produce on a variation-chart was soon disposed of by Trofessor Weldon, and we identified the crab with the Portunus higuttatus of Eisso (1816), now usually known under tlie name PJatyonicJms nasutus of Latreille (1825, p. 151; cf. also Milne-Edwards, 1834; Costa, 1853, p. 11; Carus, 1885). The genus Platyonichus of Latreille (1818) was originally coextensive with the genus PortummLs of Leach (1815), Latreille having simply altered Leach's name owing to its similarity to the name Purlimus, with which he feared it might be confused. Dana (1852), however, and Bell (1853), showed that the species included within the genus Platyoniclms were separable into two well-marked groups, which were accordingly named by these writers Platyonichus and Portumnus respectively, the latter name being reapplied to the group which included Leach's type, viz., Portumnus latipes. It is to the latter group that Platyonichus nasutus belongs, so that I must refer to it for the future as Portumnus nasutus. It is true that the earliest specific name applied to the present species is higuttatus of Risso (1816), the name nasutus of Latreille (1825) being nearly ten years later. Since, however, the species has been invariably referred to under Latreille's name, probably owing to the influence of Milne-Edwards' adoption of it, I submit that we have here an ex- ceptional case which demands exceptional treatment. The rule of priority provides a decisive method of dealing with a confused and complicated synonymy ; but its application in the present case could not be urged on such grounds, and would be distinctly inconvenient. I shall therefore adhere to the employment of Latreille's name nasutus in referring to the species under discussion. In the event, however, of possible differences being discovered between Mediterranean and Atlantic races of this species, I would point out that liisso's name CONTRIBUTIONS TO MARINE BIONOMICS. 403 was created for Mediterranean specimens, while Latreille's type came from the west coast of France. 2. Generic Characters. The genus Portumnus takes its place together with Carcinus, Platyonichus, and Pohjhius in the Platyonichinre, a sub-family of the Portunidu' distinguished from the Tortuninai by the absence of lateral ridges on the pra^labial plate, and by the absence of a distinct accessory lobe to the endopodite of the first maxillipeds. Portumnus is distinguished from Platyonichus by having the dactylus of the fifth thoracic leg of a slender lanceolate form, and the carapace not broader than long. In Platyonichus the dactylus is elliptical or broadly oval, and the carapace is broader than long. To these dis- tinctions I may add that in Platyonichus the interorbital margin is at most tridentate or quadridentate, while in Portumnus the inner angle of the orbit contributes a distinct accessory tooth to the frontal margin, rendering this margin five-toothed, as in Polyhius Hensloicii. 3. Specific Characters. The two species of the genus which alone are known to me are P. latijics (Pennant) and P..nasutus. A description of the former species may be found in Bell (1853) under the name Portumnus variegatus. The characteristic features of P. nasutus are as follows : — Frontal area projecting in front of the orbits in the form of a conspicuous triangular lobe with gently undulate lateral margins. The undulations mark the subdivision of the interorbital margin into five rounded lol)ules, which correspond to the five interorbital teeth of P. latijKS. The interorbital lobe bends downwards in front. The carapace is relatively broader than in P. Icdiiocs, so that the antero-lateral margins make a sharper angle with the median transverse axis. The orbit shows two superior fissures and one inferior fissure (imce Latreille and H. Milne-Edwards, who mention only one superior fissure), while in P. laiijKS the orbit is stated to be cither entire (Bell; Leach, 1815) or provided with a single fissure above (H. Milne- Edwards, 1834). The basal joint of the second antenna is movable. 4. Colour. The colour of the carapace of Porttimmis 7iasutus is thus described by Risso (181G, p. 31) — "yellowish-white, adorned with two great spots of coral-red . . . The red spots are larger in the female than in the 404 CONTRIBUTIONS TO MARINE BIONOMICS. male." Ou account of the presence of these spots Eisso named the species Portunus higuttatus, 2}ort2ine a deux taches, fortune himacuU (p. 25). Costa, on the other hand (Addizioni, 1853, p. 11), describes the colour as " livid olive-brown tending towards purple ; that of the feet and of the inferior face more pallid. In fresh specimens one may sometimes observe two rose-coloured spots in the middle of the carapace, which vanish after death." Of my own specimens the larger one was of a uniform dull greenish yellow colour, the smaller one having the carapace and basal joints of the legs absolutely white, and the two terminal joints of the four posterior pairs of thoracic legs coloured pale brown and amethyst-violet. No reddish spots were visible in the living specimens. It is possible that these spots are only to be observed in the breeding season, and that they are due to the colour of the reproductive glands showing through the carapace. Such a phenomenon is at any rate described by Eisso for Bathyncctes longipcs. He states (1816, pp. 30, 31): "La femelle, dans le temps des amours, est ornee de deux grandes taches d'un rouge fence sur la partie anterieure du tet." The eggs of the latter species are described as "d'un rouge aurore," which would sufficiently account for the red colour of the ovarian regions before deposition of the ova ; those of P. nasnius are described as " d'un jaune dore." Eisso states that the eggs of P. nasutiis are laid in May and August. 5. Sand-burrowing Habits. The habits of Portummis nasidus have hitherto been very imperfectly described. Eisso (18 IG, pp. 25-31) states simply that at Nice the crab inhabits "la region des polypiers corticiferes " (p. 25), or "la region des coraux" (p. 31). Latreille's specimen (1825, p. J 51) was obtained by D'Orbigny on the coast of La Vendee, which probably implies a sandy habitat, especially as Latreille's specimens of " Platyonichus varicyatiis " {Poi'tumnus latipcs) were obtained by the same naturalist on the same coast {Nonv. Did. d'lIisL Nat., 1818), and the latter species is known to have sand-burrowing habits. My own observations are, however, unequivocal. The specimens were found burrowing in coarse shelly gravel, and when the crabs were introduced into an aquarium containing a deep layer of the same gravel they were observed to burrow into it at once with extreme agility until their bodies were completely covered to a depth of an inch or more. The act of burrowing is effected by means of the hinder thoracic legs, as is usual among Portunids. The crabs can also burrow in fine siliceous, sand. When imbedded, P. nasutus seems always to adopt a nearly horizontal CONTRIBUTIONS TO MARINE BIONOMICS. 405 position — not the upright attitude exhibited by Corystes cassivdaunus (this Journal, 189G, p. 223). The anterior part of the body is, however, generally a little higher than the posterior. 6. Eespiratory Currents. Under these circumstances, Portumnus nasidus exhibits a reversed water-current through its branchial chamber, though this is much more diflicult to demonstrate in the present species than in the case of Corystes. The method I adopted was as follows : — The depth of gravel in the aquarium was so regulated that the crab could not burrow far beneath the surface. The fragments of sand and shell which lay upon the front of its carapace and upon its inter- orbital lobe were then gently removed, one by one, with a pair of fiue forceps, until the aperture of the buccal frame was exposed. These proceedings were, however, incessantly watched by the crab, which, not unnaturally, did not hesitate to disturb ray preparations whenever it conceived that there was due cause for alarm. I therefore took the precaution to leave some fragments of shell over its eyes, and thus did not seriously disturb its impression that it was safely ensconced. I eventually succeeded in getting the crab so suitably situated that, on the addition of a little black-coloured water by means of a pipette to the region in front of the crab's maxillipeds, I had the satisfaction of seeing the water sucked inwards on both sides, to reappear again in a pair of streams at the base of the chelipeds. The two exhalant streams rose above the surface of the sand in a pair of clouds, one on each side of the body. Suddenly, and without warning, the normal current was set up, and then the lateral clouds of inky water were rapidly sucked in again on each side, to re-emerge again a second or two afterwards in a continuous stream in front of the mouth. Without this kindly co- operation on the part of the crab it would have been ditticult, if not impossible, to get so successful a demonstration of the reversal of the currents. One of the most interesting phenomena presented by this crab is indeed the frequency with which, when under observation, it will alternate the direction of the respiratory currents."*^ It may even suspend the respiratory currents altogether for long intervals ; e.g., iov as long as fifty-live seconds. At such times there is absolutely no movement in the surroundintj water. 'to 7. Utility of Specific Characters. The interorbital prolongation of the frontal area, which gives both its name and most peculiar feature to the species Portumnus nasutus, is * Probably to eject distasteful particles. This is undoubtedly the explanation of similar phenomena in the case of Corystes. (See this Journal, vol. iv. 1896, p. 230.) 406 CONTRIBUTIONS TO MARINE BIONOMICS. a feature usefully correlated with a habit of burrowing in coarse shelly gravel. It acts as an ellicieut buckler for the protection of the anterior sense-organs ; but its unusual size and its downward bend seem to be more directly correlated with the reversal of the branchial currents, which I have shown tu take place when the crab is imbedded. The advantage of reversal in the present case is a point to which I shall recur when dealing with the phenomenon in a more general manner ; but, granted the reversal, the utility of the possession of a stout triangular shelf over the inhalant orifices is obvious after a study of the animal s habits and of the nature of the objects amid which the crab excavates its dwelling-place. In Corystcs, which lives in fine sand, the inhalant antennal tube has been shown (189G) to subserve the double purpose of a supply pipe and a sieve. In P. nasuius a sieve is unnecessary so long as the crab inhabits coarse shell-gravel, the fragments of which are too large to enter the respiratory channels ; and this appears to be the specific habit of the crab. But if the anterior inhalant apertures (during reversal) were altogether unprotected, the pointed fragments of shell might easily penetrate the inhalant orifices (during reversal), and so occlude their lumen. Such occlusion would prevent the crab from burrowing in the kind of material most suitable to its respiratory organisation, and thus expose the animal to increased risks of destruction by its ever-watchfnl enemies among fishes. The overhanging buckler provided by the prominent frontal lobe acts, however, as a very eificient means of supporting the shell-fragments well above the inhalant orifices — a function the existence of which I do not throw out as an academical suggestion, but the value of which I had frequent opportunities of observing and appreciating in my aquaria. The interorbital lobe of F. nasuius is remarkably similar to the frontal protuberance of Carcinus maenas in the Megalops stage, which becomes reduced in later stages of development. Since I have found no indications of a reversal of the respiratory currents in the latter species, I am inclined to believe that the retention of this larval feature in P. nasutus is to be correlated with the reversal of the currents which occurs, as I have shown above, in this type ; while its eventual loss in Carcinus maenas is to be indirectly attributed to the lack of any further use for it after the larval stages. The larval forms of P. nasutus are at present, however, unknown, and it is impossible to support this view with the necessary embryological facts. The other specific characters of P. nasuUis (viz., breadth of carapace, retention of two supra-orbital fissures, mobility of basal joint of second antenna) are not new features acquired within the history of the present species, but are merely heirlooms i'rom Portunid ancestors of less specialised habits. It is not their presence in P. nasutus which is to CONTRIBUTIONS TO MARINE BIONOMICS. 407 be accounted for, but their absence in Portumnus latipcs. The elucida- tion of those features will be attempted in a subsequent article dealing with the habits of the latter species. In conclusion I may add that a good figure of P. nasuius is given in Costa's classical memoir on the fauna of the Bay of Naples (1853). BIBLIOGRAPHY. Bell, T.— I.e. (1853). Cams, J. Victor. — Prodromus Fauwe Mediterranerti. Stuttgart, 1885. Costa, O. G. — Fauna del Regno di Napoli, 1836. Addizioni a' Decapodi Brachiuri, February, 1853, pp. 14, 15, Tav. 6, tig. 4. Daua, J. D. — "Crustacea." U.S. Exploring Expedition, vol. xiii. 1852. Garstang, W. — 1. "The Habits and Respiratory Mechanism of Corystes cassi- velaunus." Tliis Journal, iv. pp. 223-232. 18D6. „ 2. "On the Function of certain Diagnostic Characters of Decapod Crustacea." Rep. Brit. Ass. Liverpool, 1896, pp. 828-830. Latreille, M.— 1. Nouv. Did. d'Hist. Nat. 1818. „ 2, Encycl. Methodique, x. 1825. Leach, W. E.— 1. Trans. Linn. Soc, xi. pp. 306-400. 1815. „ 2. Malac. Podoph. Brit. 1815, Milne-Edwards, H. — Hist. Nat. des Grustace's. 1834. Risso, M. — Hist. Nat. des Grustace's des environs dc Nice. 1816 (Plate I., tig. 2). L ^os ] The Distribution of Marine Plankton. In order to endeavour to co-ordinate the work of the many naturalists who make use of the tow-net round the coasts of the British Isles during the year, the following circular has been issued. The list of organisms, upon the presence or absence of which information is desired, contains only such as can be quite easily recognised. The scheme must be regarded as more or less experimental for this year, with a view to findinfr out what can be done in this direction. Jllnvinc i3iolor(ical dissociation of tfjc ©Iniicti Ixingtiom. The Laboratory, Plymouth, December 30th, 1S96. Sir, — Many of tlie organisms commonly found in the plankton of the sea around the Dritish coast exhibit remarkable variations in their relative abundance at particular localities from year to year, but little is known as to the extent and causes of such variations. As a number of naturalists make use of the tow-net at many places round the coast, especially during the summer, much valuable information would be obtained if in all cases records were kept of the presence or absence of a limited number of the commoner species, and these records subsequently brought together. In the hope that you may be willing to assist in obtaining such information, I enclose a short list of organisms, the presence or absence of which I would ask you to record at any locality and as often as you may be using the tow-net during the year 1897. The records may Ije forwarded to me from time to time, and all should be sent in before January 31st, 1898. Additional copies of the list will be sent, if desired, and your assistance is requested in inducing other naturalists to co-operate in making the records. I am, Sir, yours faithfully, E. J. Allen, Director. THE DISTRIBUTION OF MARINE PLANKTON. 409 LIST OF SPECIES. List of Species to be recorded whenever and wherever possible, during the year 1897:— Hcdosphacra viridis. Noctiluca miliaris. Aurelia aurita (including Eijhyrac). Agalmopsis. Mvrjgicca atlantica. Hormiphora plumosa. Be roe. Tomoptcris. Anomalocera Fatersoni. Doliolum. Salpa. Where the generic name only is given in the above list, the specific name of the specimens taken should be added. Should any doubt exist, preserved specimens should be kept. In making a record the following should be stated : — Date. Hour. Locality. (With as much accuracy as possible.) Depth. (Depth of water, and maximum depth at which net has been worked.) r 0. Absent. 1. Few only. 2. Moderately plentiful. 3. Exceptionally abundant. Quantity Observations on the temperature of the sea, and notes on wind, tide, etc., will also be of value. llecords to be sent in before January 31st, 1898, or forwarded from time to time to the Director, Marine Biological Association, Tlymouth. [ ^10 ] An Examination of the Present State of the Grimsby Trawl Fishery, with especial reference to the Destruction of Immature Fish. ■ Revision of Tables. By Ernest W. L. Holt. About a year subsecjueiit to the appearance of my paper ou the Grimsby Trawl fishery my attention was directed to certain arithmetical errors in the table on pp. 40G and 407 (pp. 70 and 71 of the lieprint). These errors are in truth, considerable, though fortunately not of a nature to allect the arguments brought forward in the text, as will appear to such of my readers as may be at pains to compare the revised edition with the original. Although I have no intention of seeking to evade the responsibility for the figures published under my name, I may ask, nevertheless, to be allowed to advert briefly to the circumstances under which they went to press. At the time my paj)er was in preparation I was suffering from an illness that ultimately compelled me, with much regret, to sever my connection with the Association ; and when it seemed advisable to expand my original statistics of " boxes " into columns of other quantities, I found my eyesight unequal to the cyphering thereby entailed. I was therefore obliged to confide the calculations, in great part, to other hands, with results sufficiently disastrous to my own reputation for accuracy. The revision of the tables has brought to light two errors, which are not those of arithmetic, and for which the responsibility is entirely my own. In the entries for June, July, and August, 1892, it has been explained that 1000 cwt. was subtracted from the Board of Trade returns, as representing approximately the quantity of fish landed from Iceland during the said months. My intention, though not clearly explained in the text, was to subtract the amount from the aggregate ; but in the tables it was inadvertently taken from each separate month. * Journ. Mar. Biol. Assoc, vol. iii. No. 5, Special Number, pp. 339-448. Reprinted under the above title. 1895. PRESENT STATE OF THE GRIMSBY TUAWL FISHERY, 411 In the present edition this item will be found to have been altered in accordance with the actual conditions, the amount subtracted being divided between the three months in proportions which correspond roughly with the relative abundance of Iceland fish during the period concerned. The figures 49,000 in column i were a misprint for 41,000 — the Board of Trade total. A further error appears to have been made in the number of boxes for June, 1893, and this has accordingly- been altered to the number originally published in the Journal of the Association, vol. iii. p. 124. The table on p. 410 (Reprint, p. 74) is dependent on the calculations in the former table, and is therefore vitiated by the errors alluded to. It happens, however, that the revision of this table only brings into greater prominence the destruction of undersized fish. My attention has recently been drawn to the absence of any definite statement in my text as to the method by which the averages of number of fish in boxes of different qualities were deduced. At this lapse of time I regret that I am unable to lay hands upon the original figures, and can only state that I deduced averages from the contents of a large number of boxes of each quality counted during the earlier period of my work, and checked the results so obtained from time to time during the later years; and in order to run no risk of exaggerating the proportion of undersized fish, I actually made use of averages which somewhat underestimated such proportion. It remains for me to express my indebtedness to the Association for publishing this corrected version of my tables (which my own circum- stances did not allow of my undertaking), and to Professor Weldon and Mr. E. J. Allen for tlie revision of my figures. NEW SERIES. — VOL. IV. NO. 4. 2 F 412 THE PRESENT STATE OF THE GRIMSBY TRAWL FISHERY. Table shoiving the Weight, Bulk, and approximate Numlcr of Plaice fishing 2^ower {in voyages of steam-trawlers) The terms "large" and "small " in this talile refer only to the market designation under All Dekp-sea Grounds. North Ska. Total. Total. Cwt. Boxes. Fish. Cwt. Boxes. Fish. 1892. i ii iii iv V vi April .... 11,000 9,778 1,253,200 11,000 9,778 1,253,200 May .... 12,000 10,667 1,191,200 12,000 10,667 1,191,200 June .... \ ( 11,075 9,844 1,504,900 July .... [41,000 36,355 4,697,450 17,650 15,689 1,877,750 August .... ) ( 11,275 10,022 1,290,800 Septoiubor 15,000 13,333 l,.'.l 0,900 15,000 13,333 1,510,900 October .... 20,000 17,778 1,822,050 20,000 17,778 1,822,050 November 20,400 18,133 1,813,300 20,400 18,133 1,813,300 December 11,000 9,778 977,800 11,000 9,778 977,800 1893. January .... 10,000 8,889 892,050 10,000 8,889 892,050 February 7,600 6,756 680,250 7,600 6,756 680,250 March .... 10,000 8,889 888,900 10,000 8,889 888,900 April* .... 12,213 10,833 1,471,650 11,963 10.633 1,463,650 May .... 23,580 20,439 2,953,020 17,726 15,756 2,765,700 June .... 22,919 19,555 2,313,250 13,731 12,205 2,019,250 July .... 29,760 25,190 2,259,290 15,540 13,814 1,804,250 August .... 22,992 19,675 1,806,610 14,424 12,821 1,532,450 September 13,864 12,296 1,334,000 13,552 12,046 1,324,000 October .... 18,215 16,191 1,710,450 18,215 16,191 1,710,450 November 12,621 11,219 1,244,300 12,621 11,219 1,244,300 December 6,141 4,570 470,050 5,141 4,570 470,050 1894. January .... 5,021 4,463 477,650 5,021 4,463 477,650 February 4,134 3,674 377,900 4,134 3,674 377,900 March .... Total for year ending \ March, 1894 ) 9,378 8,336 1,061,150 9,378 8,336 1,061,150 179,838 156,441 17,479,320 141,446 125,728 16,250,800 April .... 21,179 18,705 3,068,490 19,822 17,619 3,025,050 May .... 17,914 15,577 2,174,230 14,018 12,460 2,049,550 June .... 18,277 . 15,939 2,139,720 14,829 13,181 2,029,400 July .... 17,880 15,559 1,752,160 14,119 12,550 1,631,800 August .... 19,441 17,206 1,886,590 18,608 16,540 1,859,950 September Total for six months . 19,466 17,303 1,871,300 19,466 17,303 1,871,300 114,157 100,289 12,892,490 100,862 89,653 12,467,050 * Totals previous to this date are taken from ofiicial returns. THE PRESENT STATE OF THE GRIMSBY TRAWL FISHERY. 413 landed at Grimshj by deep-sea tratvlers, and (col. xvi) the diversion of from the North Sea grounds in each month. which the tisli so euumerated are sold. Vide text, pp. 402 and 403 (pp. 66 and 67 of Reprint). North Sea. Iceland. Large. SraalL • Cwt. Boxes. Fish. Voyages. Cwt. Boxes. Fish. Cwt. Boxes. Fish. vii viii ix X xi xii xiii xiv XV xvi 8,935 7,942 794,200 2,066 1,836 459,000 11,067 9,837 983,700 934 830 207,500 . . . 7,171 6,374 637,400 3,904 3,470 867,500 ) ••• 15,334 13,630 1,363,000 2,316 2,059 £14,750 1,000 800 24,000 ? 9,110 8,098 809,800 2,165 1,924 481,000 ) ... ... l.%668 12,149 1,214,900 1,332 1,184 296,000 . . . .. . 19,668 17,483 1,748,300 332 295 73,750 20,400 18,133 1,813,300 ... 11,000 9,778 977,800 ... ... ... ... ... ... 9,977 8,868 886,800 24 21 5,2.^.0 7,566 6,725 672,.500 35 31 7,750 10,000 8,889 888,900 ... ... 8,960 7,964 796,400 3,003 2,669 667,250 250 200 8,000 2 8,800 7,822 782,200 8,926 7,934 1,983,500 5,854 4,683 187,320 20 7,740 6,880 688,000 5,991 5,325 1,331,250 9,188 7,350 294,000 30 12,369 10,995 1,099,500 3,171 2,819 704,750 14,220 11,376 455,040 36 12,.546 11,152 1,115,200 1,878 1,669 417,250 8,568 6,854 274,160 21 12,656 11,250 1,125,000 896 796 199,000 312 250 10,000 1 17,530 15,582 1,558,200 685 609 152,250 11,703 10,403 1,040,300 918 816 204,000 . . . ... 5,043 4,483 448,300 98 87 21,750 ... ... 4,786 4,254 425,400 235 209 52,250 4,055 3,604 360,400 79 70 17,500 7,671 6,819 681,900 1,707 1,517 379,250 ... 113,859 101,208 10,120,800 27,587 24,520 6,130,000 38,392 30,713 1,228,520 110 10,348 9,198 919,800 9,474 8,421 2,105,250 1,357 1,086 43,440 7 7,991 7,103 710,300 6,027 5,357 1,339,250 3,896 3,117 124,680 25 9,494 8,439 843,900 5,335 4,742 1,185,500 3,448 2,758 110,320 21 11,293 10,038 1,003,800 2,826 2,512 628,000 3,761 3,009 120,360 19 17,063 15,167 1,516,700 1,545 1,373 343,250 833 666 26,640 5 18,408 16,363 1,636,300 1,058 940 235,000 ... ... ... 74,597 66,308 6,630,800 26,265 23,345 5,836,250 13,295 10,636 425,440 414 PRESENT STATE OF THE GRIMSBY TRAWL FISHERY. Table shoioing the Numbers and Projwrtion of Plaice of different sizes landed at Grimsby by deep-sea trawlers in one year. Sexually 13 inches and ' Below Mature. Imiuatan above. 13 inches. 17 inches and above. Below 17 inches. No. % No. % iv No. % No. % i ii iii V vi vii viii 1893. April . 557,480 38 906,170 62 783,485 53 680,165 47 May . 547,540 20 2,218,160 80 902,330 33 1,863,370 67 •luno 481,600 24 1,537,650 76 752,325 37 1,266,925 63 July . 769,650 43 1,034,600 57 1,060,025 59 744,225 41 August 780,640 51 751,810 49 1,045,405 68 487,045 32 September . 787,500 59 536,500 41 1,032,400 78 291,600 22 October 1,090,740 64 619,710 36 1,417,605 83 292,845 17 November . 728,210 59 516,090 41 956,670 77 287,630 23 December 313,810 67 156,240 33 405,645 86 64,405 ] 14 1894. January 297,780 62 179,870 38 388,085 81 89,565 19 February 252,280 67 125,620 33 326,110 86 51,790 14 March . 477,330 45 583,820 55 56 651,635 61 60 409,515 39 40 Total for year 7,084,560 44 9,166,240 9,721,720 6,529,080 [ -iis ] Director's Report The number of workers who have occupied tables at the Laboratory during the winter mouths has not been large. It becomes increasingly evident that the amount of work which can be carried on during this period of the year must depend upon the number of naturalists who can be employed by the Association to undertake general or special investigations. At the present moment our funds will only permit of the employment of one such naturalist, who is engaged in fishery investigations. My own time is so much occupied with administrative and other duties, that comparatively little of it can be devoted to scientific research. It may be worth while to point out once more that whilst the United States Commission of Fish and Fisheries is allowed an annual sum of £35,000 for salaries alone, a considerable portion of which is devoted to the payment of naturalists engaged in research, the total income of the Marine Biological Association amounts to only about £2000 a year. Since the publication in August of the last number of the Journal, the following naturalists have visited the Laboratory : — Brebner, G., August 1st to October 6th, 1896 ) December 30th, 1896, to Jan. 18th, 1897 \ (^^^'"'^^^ ^^^^^')- Brumpt, E. (Paris), September 8th to 24th {General Zoology). Church, A. H., B.A., July 8th to September 30th {Marine Algcc). Goodrich, E. S., B.A., January 4th to 11th {Holothurians). ]\Ienon, E., August 24th to October 13th {Nervous System of Mollusca). Riches, T. H., B.A., January 13th to December 10th {Nemertines). Scott, S. D., B.A., July 28th to November 20th {Ascidians). Early in December we received a visit from a party of four fishermen, who, under the auspices of the Technical Education Committee of the Aberdeenshire County Council, were making a tour of the varioifs fishing centres of England and Scotland, accompanied by Mr. liobert TurnbuU, B.Sc, who acted as instructor. "We arranged for two lectures on the Natural History of Eishes to be given for the benefit of the party, and assisted them as much as possible in seeing the various methods of fisliing practised in this port. Mr. F. B. Stead, who has been working at food fishes at Plymouth, has left for Naples, where he is at present occupying the Cambridge 2 F* 416 director's report. University table. Mr. S. D. Scott, of King's College, Cambridge, is temporarily assisting me to carry on the fishery investigations. The work on the east coast, commenced by Mr. Holt and subsequently continued by Mr. Cunningham, has now ceased owing to lack of the necessary funds for its maintenance. The experimental trawling in the bays on the Devonshire coast has been continued during the autumn and winter. The results of the trawlings in January show clearly, as was to have been expected, that the larger plaice have left, probably for the spawning grounds, whilst the fish from the estuaries and from close inshore have come out into the bays. Thus in Teignmouth Bay, whereas in October and December 4 per cent, only of the plaice were 7 inches and under, in January the proportion at this size and under had increased to 32 per cent. In connection with studies on the distribution of fish eggs, larvre, and young fish, a series of experiments has been started for determining the surface drift in the western portion of the English Channel by means of floating bottles. The experiments are similar to those which have been made by l*rof. Herdman in the Irish Sea, and by the Scottish Fishery Board in the North Sea ; but we have adopted a bottle of somewhat larger size, in order to counteract as much as possible the direct action of the wind upon the bottle itself. Ordinary egg- shaped soda-water bottles are being used, weighted with shot in such a way that the bottle floats vertically, the shot being kept in place by being imbedded in solid paraffin. The thanks of the Association are due to Admiral the Hon, Sir E. E. Fremantle, Commander-in-Chief at Devonport, who has kindly arranged for bottles to be put overboard by the torpedo-boat destroyers cruising in the neighbourhood. This will enable us to carry out the experiments in a much more satisfactory way than would otherwise have been possible. Owing to the rugged nature of the coast, I do not anticipate that we shall recover so large a percentage of the bottles as was the case in Prof Herdman's and the Scottish experiments, Witli a view to obtaining information as to the distribution of marine plankton, a scheme has been arranged to endeavour to co-ordinate the work of the many naturalists who frequently make use of the tow-net around the British coasts. A further account of this will be found on p. 408. The dredging and trawling work on the grounds between the Eddy- stone and Start Point was continued during last summer, and the results of about seventy hauls have been worked out. It is hoped that the results of this work, which has been carried on regularly for two summers, will shortly be ready for publication. In promising to place on the estimates for the year 1897-98 the director's report. 417 usual grant of £1000 to the Association, the Lords Commissioners of H.M. Treasury have made it a condition of the grant tliat the Association will give all the assistance in its power to the Inspectors of Irish Fisheries in investigations which they desire to be made on the habits, etc., of the mackerel visiting the Irish coast. In connection with this subject, a report is being prepared upon the present state of knowledge of the natural history of the mackerel in all parts of the world. Mr. Cunningham's book on the Natural History of the Marketable Marine Fishes of the British Islands, which has been published for the Association by Messrs. Macmillan & Co., has been very favourably noticed by the Press, and there seems little doubt but that it will be regarded as a standard popular work on the subject. The system of filtering sea -water through layers of blanketing, which was devised in connection with the hatchery at Dunbar, has been adopted for the Aquarium here with satisfactory results. The supply of water from the sea has been greatly interfered with owing to the pipe which brings the water to the ejector having been damaged by the stranding of the steamship Ariel on the rocks below the Laboratory. The pipe has been repaired, and we are advised that the owners are liable for the damage done. The Busy Bee, which has now been in regular use for twelve months, continues in good condition, and has given very little trouble in the way of repairs. We have found her coal consumption remarkably low, and the expense of running her has been considerably less than was anticipated. We are now having a compact trawling winch, capable of carrying a drum of wire-rope, built for her, which will greatly increase her usefulness. I regret to say that the whole of the money for this vessel has not yet been subscribed. With the necessary fittings, including the winch, a sum of nearly £700 has been spent. Towards this amount, as will be seen from the list which follows this Report, £537 14s. has been given. We are very anxious that the balance should be met during the present financial year, which ends in May. E. J. Allen. February, 1897. [ 418 ] Steamboat Fund. LIST OF SUBSCEIPTIONS TO JANUARY, The Worshipful Company of Fishmongers The Royal Society . J. P. Thomasson, Esq. The "Worshipful Company of Drapers ,, „ „ Grocers ,, ,, ,, Mercers „ „ „ Skinners „ ,, „ Goldsmiths The Earl of Ducie . Sir Henry Thompson E. L. Beckwith, Esq. Mrs. E. S. Heywood The Earl of St. Germans R. Assheton, Esq. G. Fry, Esq. J. j\Iackrell, Esq. E. Grove, Esq. S. F. Harmer, Esq. S. Makowski, Esq. W. H. St. Quintin, Esq. A. 0. Walker, Esq. . W. I. Beaumont, Esq. 1897. £ s. d. 105 0 0 100 0 0 100 0 0 52 10 0 50 0 0 2G 5 0 21 0 0 20 0 0 10 0 0 10 0 0 5 5 0 5 5 0 5 0 0 5 0 0 5 0 0 5 0 0 3 0 0 2 2 0 2 2 0 2 2 0 2 2 0 1 1 0 £537 14 0 OCT 1 1337 [ ^i'-» ] INDE r Acanthias vulyaris, 41, 45 Achrochcetium enrJojihyticiim, 286, 287 Actinotrocha, 171 Acialmojists, 409 Aglaophenia, 49 — Helleri, 153 — 2^luma, 153 Ahnfeltia plicata., 287 Albunea symnista, 232 Alcyonium cliyitatuin, 38, 51 Algological Notes, 179, 286 Allen, E. J., see contents Amarcecium puncfum, 84 Amphicodon ampMpleurus, 50 Ampliinema dinema, 169 AmpihioKUs lanceolatus, 34, 171, 250 Anchor ella enutryinata, 163 — paradoxa, 163 — qimdrata, n. sp., 163 — ?>%/«;, 163 — uncinata, 163 Anchovy, 134 Awjuilla ncKfirostris, 375, 377 — latirostns, 376, 377 — mediorostris, 376 — rulf/aris, 375 Anovifdncern Prifemoyn, 175, 409 Aplidium ::oiitcnmla, 84 Aplysia ptindatn, 51 Acrochmtium microscojncum, 287 Arenicola, 51 Arnoyhssvn laterna, 380 /I sterias (jlacialu, 268 Adrnpeden aura7itiani$, 267 Atelecydus heterodo7i, 232, 397, 399 Anrdin anrifa, 50, 409 NEW SEUIES. — VOL. IV. NO, 4, B. Balance-sheet, 86, 307 Balcenoptera Sibbaldii, 237 Baltic, Northern species in, 237, 255 — Southern sjjecies in, 236 Bassett-Sniith, P. W., see Contents. BaUiynedes longipes, 397 res])iratory process, 398 Beroe, 170, 409 Bethe, A., see Contents Bidder, G., see Contents Biddulphia mobilensis, 383 Bionomics, contributions to Marine, 223, 396 Bolina hydatina, 50 Boiujainvillia, see Margelis Brachiella bispinosa, 163 — impudica, 162 var. jKirva, 1 63 — insidiosa, 162 — thynn% 162 — tri/jlce, 163 Braihyura Oxystoniata, phylogeny, 400 Brebner, G., see contents Brill on the German Grounds, 107 — size limit for, 143 — size and maturity, 32 Browne, E. T., see Contents Brown Ridges, comparison with Ger- man Coast, 131 Burrowing Crabs, function of antero- lateral denticulations in cara- pace of, 396 Burrowing habits of Portumnus nasutus, 404 liutler, (!. W., see Contents 420 INDEX. C. CulannsJinmarchicIiHs, 382 Caligidct, 156 Caligns hrevipedis, w. sp., 157 — curt us, 157 — diaphanus, 156 — elerjans (?), 156 — gurnardi, 157 — minimus, 156 — Mullen, 157 — rapax, 156, 177 — scomberi, n. sp., 156 — tenuis, 156 Callinectes sapidus, 400 Gallocolax neglect us, 180 Ccdycella syringa, 148 GV( ?n|»rt?i ?t/( ( nV f Jkxiwsa, 147 — fragilis, 147 — ncglecta, 147 Candace pectinata, \11 Cardnus, abnovinal specimen, 144 Catoinetopa, burrowing habits, 396 Cecrops Latreillei, 159 Ceyitropages hamatus, 236 — typicus, 175, 176 Ceratium divergens, 382 — >rca, 382 — fiisus, 382 — ;ry;os, 175, 176, 381 Getochilus septentrionalis, 175, 176 Ghcctoceros atlantictis, 383 — borealis, 383 — curvicetus, 383 — didymus, 383 — grmdaiulicus, 384 — socicdis, 384 — scolopendra, 384 — 2. The (Oyster C'ulturr of the Ancient Romans, v:ith Plate I. By K. T. GiJNTHER, M.A. . . . ... .360 3. Hixent REPORT.S of Fishery Authorities . ... 366 4. ^[icRoscopic Marine Organisms in the Service of Hydrography'. By Prof. P. T. Cleve . . . ... 381 ;"). ' The Regulations of the Local Sea Fisheries Committees in England and Wales. By E. J. Allen, B.Sc. . . . 386 C. Contributions to Marine Bionomics. Jiy Walter Garstang, M.A. n. Tlie Functions of Antero-Lateral Denticulationa of the Carapace in Sand-burrowing Cral»s . . ... 396 III. The Systematic Features*, Hal)it.s, and Respiratory Phenomena of Portumnus nasutus (Latreille) . ... 402 7. The Distribution of Marine Plankton . ... 408 8. An Examination of the Present State of the Grimsby Trawl Fishery, with especial reference to the Destruction of Immature Fish. Revision of Tables. By E. W. L. Holt . . 410 9. Director's Report . . . . • . . 415 K). Steamboat Fund— List of Subscribers . ... 418 NOTICE. The Council of the Marine Biological Association wish it to he understood that they do not acce))t responsil)ility for statements juildished in this Journal, excepting when those statements are contained in an ollicial report of the Council. TERMS OF MEMBERSHIP. & s. d. Annual Members .... l)er annum. 1 1 0 Life Members . . . Composition Fee. 15 15 0 Founder.-* . . . • . . 100 0 0 Governors . . . ... 500 0 0 Members of the Association have the following rights and privileges ; they elect annually the Officers and Council ; they receive the Journal of the Association free ])y post ; they are admitted to view the Laboratory at Plymouth, and may introduce friends with them ; they have the first claim to rent a place in the Laboratory for research, with use of tanks, boats, &c., and have access to the books in the Library at Plymoutli, All correspondence should be addressed to the Director, The Laboratory, Plymouth. 3 2044 093 366 730 Date Due FEB U 1956 'vW* k. ■ ' -''* \ j^ fffnri^