bluuebunny/crossref_metadata_2025 huggingface dataset:
Wind currents, tidal streams and plankton off the Northumberland coast
Authors: Evans Frank
Published: May 2009

Investigations of the water movements off the southern Northumberland coast have until now been confined to the surface region. While important for navigational and similar purposes such investigations can give us no more than an indication of the total water flow along the coast nor can they elucidate the effects of currents on planktonic organisms which spend part or all of their existence away from the surface. It is for the latter reason that the series of investigations of sea surface currents made aboard the R.V. ‘Alexander Meek’ in 1956–7 (Evans, 1957) has now been supplemented by further series at two deeper levels.
The polychaeteMagelona filiformissp. nov. and notes on other species ofMagelona
Authors: Wilson Douglas P.
Published: May 2009

As already mentioned (Wilson, 1958), a species ofMagelonafrom clean sand near low water at Mill Bay, Salcombe, has not yet been described. This worm was first noticed in 1939; it is recorded in the 1957 edition of thePlymouth Marine Faunaas ‘Magelonasp.’ and it is there mentioned that artificial fertilizations were made and larvae reared in April-September 1939, and that these larvae differed from those of the other twoMagelonaspecies from the Plymouth district (papillicornisF. Müller andalleniWilson). The worm is still common in the same locality at Salcombe, in the same ground and often in the same spade-full aspapillicornis, but it is not as abundant as the latter and probably not as abundant as it was when first seen in 1939. A very good low tide receding below datum is needed to collect it; it is easily overlooked on account of its fragility and fine thread-like appearance, mature females coloured pink by their contained eggs being more readily seen while digging than translucent immature worms or white males. Worms are difficult to collect whole, the tail end usually being left behind in the sand.
The British species of Lutraria (Lamellibranchia), with a description of L. angustior Philippi
Authors: Holme N. A.
Published: May 2009

The Lutrariidae are large lamellibranchs which burrow deeply in bottom-deposits on the shore and in shallow water. The foot is relatively weak, and they live permanently buried 30 cm or so beneath the surface, maintaining connexion with the overlying water through their long siphons, which are united in a common sheath for practically their whole length. The commonest British species, Lutraria lutraria (L.) is found at low-water mark on shores of muddy sand, and offshore its siphons are sometimes taken by the dredge or grab. Another species, L. magna (da Costa) is more local, and appears to inhabit muddy deposits near the mouths of estuaries. It is a southern form, being occasionally found on the south and west coasts of the British Isles, and, like L. lutraria, its range extends southward to the Mediterranean.
Some parameters of growth in the common intertidal barnacle, Balanus balanoides (L.)
Authors: Barnes H. , Barnes Margaret
Published: May 2009

It is difficult to determine the weight or nitrogen content of the living tissues of an operculate barnacle without destroying it. It has been customary, there-fore, in ecological work to express growth in terms of various parameters determined from repeated measurements of the shell. Moore (1934) employed shell volume calculated from the height and basal diameters; others (Costlow & Bookhout, 1953, 1956; Mawatari, Hirosaki & Kobayashi, 1954a, b) have used the area of the basis. Most commonly, however, in growth-rate studies the length of the basis measured through the rostro-carinal axis has been used (Hatton, 1938; Barnes & Powell, 1953). Recently, working with animals cultured in the laboratory when the cast of an individual could be obtained subsequent to ecdysis, Costlow & Bookhout (1957) have used the size of the mouthparts as a measure of growth after first establishing their relation to body size. The space, both areal and volumetric, occupied by a sedentary animal is of primary importance in studies of its ecology and measurements of shell-size are, therefore, adequate for many purposes. For some aspects of growth and ecology it is, nevertheless, very desirable that the relation between such parameters and others, more directly connected with the living material, should be established.
Nitrate in the Sea.
Authors: Harvey H. W.
Published: May 2009

1. A method of estimating nitrates in sea-water is described.

2. A considerable concentration of nitrates occurs in the depths of the ocean and a very low concentration (0 to 10 parts per 1000 million of nitrate-nitrogen) in the surface layers of those areas where there is no upwelling of water from below.

3. The nitrates in the water of the English Channel, twenty-two miles south-west of Plymouth, are almost entirely utilised by phytoplankton in the summer, and commence to be reformed from ammonium salts at a greater rate than they are utilised by the end of the summer.
Seasonal Changes in the Silica Content of Natural Waters in Relation to the Phytoplankton.
Authors: Atkins W. R. G.
Published: May 2009

1. The method of Dienert and Wandenbulcke permits of the estimation of silicate in solution down to the limit of 0-04 mg. of silica per litre, which cannot be distinguished from zero. The phosphate normally present does not interfere with the reaction.

2. All fresh waters examined were found to contain more silicate than does the water of the English Channel.

3. The water of Plymouth Sound is richer in silicate than that of the sea.

4. At Station El in the English Channel silicate decreases during spring, from a winter maximum of 200-240 mg. per cubic metre, so that from April to June, 1925, the amount left, recorded as 40 mg. per cubic metre, was indistinguishable from zero. At this time the water was stripped of phosphate also. Silicate increased again till early July, decreased in August and again in November ; the times of decrease are suggested as being those of diatom increase.

5. In deep Atlantic water silicate is much more abundant than in the English Channel; values from 360 mg. per cubic metre at 1000 metres to 1200 mg. at 3000 metres were obtained. In winter at any rate the surface value in the Atlantic is similar to that off Plymouth, about 110 mg.per m3 in 1925.
Modification by Habitat in the Portuguese Oyster Ostrea (Gryphcea) angulata.
Authors: Orton J. H. , Awati P. R.
Published: May 2009

While working on the beds in the River Blackwater, Essex, a collection of Portuguese oysters, which had been dredged along with native oysters (O.edulis) from the river and creeks, was seen at a glance to show a distinct average difference in shape from the usual type of Portuguese oyster. The ordinary Portuguese oyster as seen exposed for sale is usually im-ported when quite small, or occasionally well-grown, and relaid on English beds at or above low-water mark to grow and fatten. Orton* has shown by definite experiments on the same beds that the Portuguese oyster spawns and spats in English waters in favourable (hot) weather. There can be no doubt, therefore, that the Portuguese oysters dredged had grown in situ from larvae which had developed in the waters of the river and creeks. In Portugal and France the Portuguese oyster is stated to occur at and just below low water springs (see Bashford Dean, Bull. U.S.F.C. XI, 1891 (1893), p. 368), and is apparently hand collected at the present day for export purposes.

A difference in shape in native oysters is very common, but Bell and others have so far found it a very difficult matter to correlate any particular shape with a particular environment. Indeed, Bell stated, in a letter, that each locality seems to have its own type of shell-growth in the native oyster. Such a difference as that noted above in the Portuguese oyster was therefore deemed worthy of some attempt at expression.
Stages in the Life History of Calanus finmarchicus (Gunnerus), Experimentally Reared by Mr. L. R. Crawshay in the Plymouth Laboratory
Authors: Lebour Marie V.
Published: May 2009

[The stages in the development of Calanus finmarchicus described and figured by Miss Lebour in the present paper were taken from culture jars given into my charge by Mr. L. R. Crawshay, when he left the Laboratory to undertake military duties in connection with the war. In one jar at that time the first copepodid stage, from eggs laid in the jar, had just been reached, and the technical details for the successful rearing of the animals had been mastered. The experiments had been conducted with great care, and all possible precautions had been taken to prevent contamination. Subsequently the experiments were repeated up to a certain point by myself and some additional stages obtained to complete the series.

The cultures were made in 2-litre glass beakers, containing “outside” sea-water filtered through a Berkefeld filter. In order to secure an even temperature the beakers stood in the circulating water of the Laboratory tanks, and a pure culture of the diatom Nitzschia closterium was used as food.—E. J. Allen.]
Notes on the Life History of Anaphia petiolata (Kröyer)
Authors: Lebour Marie V.
Published: May 2009

In the early summer of 1915 it was' noticed that many medusæ brought in with the tow-nettings contained larval Pycnogonids in the manubrium and at the junction of manubrium and stomach. The medusæ specially noticed to contain them were Obelia sp., Cosmetira pilosella, Turris pileata, Stomotoca dinema and Phialidium hemisphericum. By far the greater number were in Obelia, although many were in Phialidium hemisphericum and Cosmetira pilosella. They were extremely abundant in June, after that became scarcer, and finally disappeared by October. On examination they were seen to be larval stages of Anaphia petiolata (Kröyer), a Pycnogonid common in Plymouth Sound. The older larvæ sometimes were seen to cast their skins, so that the species could be easily recognised, although the fourth pair of walking legs were not fully developed. This is evidently the species described by Dogiel (1913) as Anoplodactylus pygmœus, the life history of which he traces from its first entry into the Obelia hydroid to the older stages when it is ready to leave its host. The form he refers to as Anoplodactylus petiolatus occurring in cysts in Coryne with Phoxichilidium femoratum must be some other species, as his figures prove clearly that it differs from A. pygmœus, and also the colour is totally different (a bright pink, while the present form is a pale yellow). Dogiel believes he has proved that Anoplodactylus petiolatus and A. pygmœus are different species from the difference in their life histories, and it is evident that he is dealing with two different species, but his A. petiolatus cannot be the same as our form, which is certainly identical with his A. pygmœus, and shows that Sars (1891) and Norman (1894) were right in regarding A. pygmœus as the young form of A. petiolatus (Kröyer).
Notes on the Œcology of Cirratulus (Audouinia) tentaculatus (Montagu)
Authors: Flattely F. W.
Published: May 2009

Cirratulus tentaculatus is found inhabiting the wet, sandy, somewhat foul mud of the Aberystwyth shore, chiefly in the Laminarian zone, although it also occurs in rock pools higher up the shore in which there is sufficient depth of sand containing the necessary organic matter. The presence of the worm in its natural habitat is indicated by a group of delicate, elongate, rosy or yellow coloured filaments of tentacular appearance which protrude from the sand into the pools left by the receding tide. These filaments nearly always display a certain amount of movement, either waving gently from side to side or curling slightly from the tips. The amount of motion and also the colour of the filaments will depend on the degree of freshness of the water in the pool, and this, of course, will, in its turn, be related to the state of the tide.

Specimens are not easy to collect owing to the marked propensity the animal exhibits for lying with its body beneath stones or pieces of rock embedded in the mud. In rock pools or crevices where there is but little depth of sand and the animal lies with its body more or less parallel to the surface collection is almost impossible. This response to stimuli of contact and pressure, or, as M. Georges Bohn has it, this “thygmotactism,” is very marked, and, in the aquarium, when specimens are placed in a vessel containing sand and a few stones, the animals will roam about till some portion, at any rate, of their bodies is undergoing pressure from those stones.
Order Leptomedusae
Authors: Kramp P. L.
Published: May 2009

Hydromedusae with umbrella usually hemispherical or flattened; with gonads on radial canals; marginal sense organs, when present, in form of cordyli or marginal vesicles of ectodermal origin; occasionally with ocelli.
Order Coronatae
Authors: Kramp P. L.
Published: May 2009

Scyphomedusae with the umbrella margin cleft into lappets; with a single mouth opening provided with simple lips; with sense organs (rhopalia) and solid marginal tentacles arising from clefts between the lappets; with a circular, coronal furrow in the exumbrella, and peripheral to this a zone of gelatinous thickenings (pedalia) divided by radiating clefts alternating in position with the tentacles and rhopalia.
The Food of Young Herring
Authors: Lebour Marie V.
Published: May 2009

The Herring season of 1923–24 was a peculiarly good one, the fishery continuing from the end of October into the beginning of February.

Newly hatched Herring were first observed on December 17th, 1923, and post-larvæ were abundant up to March, 1924, in the neighbourhood of Plymouth.

Investigations were made into the food of these young Herring, and the probable depth at which they were feeding. Hauls with Young Fish Trawl were made near the surface, midwater, and near the bottom, and tow-nettings were also taken. It has, however, now been found by Mr. Russell that the samples assumed to be near the bottom were possibly in reality some distance above it.
Temperature and the Viscosity of Protoplasm
Authors: Pantin C. F. A.
Published: May 2009

(1) The effect of temperature on the viscosity of the protoplasm has been determined in the unripe eggs ofNereis diversicolorby the centrifuge method.

The viscosity rises as the temperature falls, the rise becoming rapid near 0°C.

(2) These changes of viscosity with temperature are similar to those described by Weber (21) in the protoplasm of certain plant cells.

(3) Attention is drawn to the fact that the temperature coefficients of biological processes should be corrected for the viscosity of the protoplasm in which they occur.

(4) It is shown that the relative changes of protoplasmic viscosity with temperature are probably of the order required to make the temperature coefficients of biological processes constant when corrected for the viscosity factor.

(5) The magnitude of the temperature coefficients of biological processes when corrected for viscosity changes is probably of the same order as that of the temperature coefficients of a chemical process when corrected for changes in the viscosity of its medium.
Recherches sur le Développement post-embryonnaire de la Langouste commune (Palinurus vulgaris).
Authors: Bouvier M. E.-L.
Published: May 2009

C'est surtout pour étudier le développement post-embryonnaire de la Langouste commune (Palinurus vulgaris Latr.) que je me suis rendu au Laboratoire de Plymouth. L'endroit me semblait excellent parce que la Langouste n'est pas rare près des côtes dans les eaux du Devonshire et de la Cornouaille, parce qu'elle est principalement fréquente sur les fonds rocheux au-dessus desquels se dresse le phare d'Eddystone, aussi enfin, parce que le Laboratoire de Plymouth est très bien installé, avec un bateau, l'Oithona, qui peut se rendre en mer chaque jour et effectuer les pêches les plus diverses.
Observations nouvelles sur les trachelifer, larves lucifériformes de Jaxea nocturna
Authors: Bouvier M. E.-L.
Published: May 2009

Durant mon premier séjour au Laboratoire de Biologie maritime de Plymouth, en qualité de “first Ray Lankester Investigator,” j'ai eu la bonne fortune de trouver un certain nombre d'exemplaires de la très curieuse forme larvaire découverte en Ecosse, prés d'Arran, par G. Brook (1889) qui lui donna le nom de trachelifer.
On the Breeding Habits of Echinus miliaris, with a Note on the Feeding Habits of Patella Uulgata
Authors: Orton J. H.
Published: May 2009

While on shore-collecting expeditions in this district it was frequently observed that Echinus miliaris has the habit of associating together in pairs, and sometimes in groups of more than two. The association of these pairs and groups is sometimes so intimate that it is not possible to interpose even the blade of a penknife between the interlocking spines of the urchins. In all cases observed except one, such pairs were placed side by side, but in one particular case the apical region of one individual was almost certainly placed adjacent to the apical portion of the other. In all the collecting expeditions—made at various times of the year between April and August—on which groups were collected, the total number of urchins of all sizes obtained amounts to about 710. Among this number were obtained 84 groups, which amount in all to 189 specimens. In the earlier part of the investigation a group was taken as such if the members were merely fairly close together, but afterwards only those specimens were recorded which were actually touching one another in the manner described above. Out of the total of 84 groups only 27 were actually recorded definitely as touching one another, although some of the other groups may have been touching. Of these 27 closely associated forms all the individuals were ripe except 3 small specimens belonging to two pairs which were recorded as having an immature gonad. The remainder consisted of 19 pairs, 2 pairs, 1 pair, and 3 groups respectively.
On Lumbricillus Scoticus n. sp.
Authors: Elmhirst Richard , Stephenson J.
Published: May 2009

A small orange-coloured Enchytraeid Oligochaete has been known for some years to occur fairly abundantly in certain sheltered parts of the shore on the Cumbraes. It is also generally present, though scarce, on exposed parts of the shore. Hitherto it has been confounded with other species of Lumbricillus, but is now described as a new species.
A New Type of Luminescence in Fishes. II.
Authors: Hickling C. F.
Published: May 2009

Texperiments are described which indicate that there is a physiological problem quite apartfrom the chemical problem of luminescence in the secretion of Malacocephalus Icevis(Lowe). The luminiferous substances are present in granules, which behave as though each were bounded bya membrane whose permeabilities resemble those of a typical cell, but differ from a cell in that they have little or no power of recovery from adverse conditions.

For optimal luminescence they require (i) a medium of a certain osmotic pressure,(ii) a certain range of alkalinity, (iii) a certain range of temperature, and (iv)abundant oxygen. Sea-water is not necessary for luminescence.

If they are exposed to extremes of acidity or alkalinity, or of hypotonic or hypertonic solutions, irreversible changes rapidly set in in the membrane of the granule, whereby the power of luminescence is lost.

In artificial conditions the rapid fading of the light from the initial brilliance is probably due to an increasing acidity caused by the accumulation of the products of oxidation.
The Food of the Bottom Fauna of the Plymouth Fishing Grounds
Authors: Hunt O. D.
Published: May 2009

1. The food of the bottom fauna of the Plymouth fishing-grounds, at an average depth of 27 fathoms, lias been investigated. This has been done by the examination of the stomach contents of animals, both fresh and preserved, and supplemented by observation of living animals in aquaria.

2. The sources of food have been discussed. Attention is drawn to the importance in these regions, not so much of organic detritus, which is considered by Petersen and Blegvad to be the only important ultimate supply in Danish waters, but of the contributions from the plankton itself and from the considerable microflora and microfauna inhabiting the bottom deposits.

3. Petersen and Boysen Jensen have stated that the detritus present in Danish waters can be traced almost entirely to the annual decay of the Zostera beds. The area occupied by Zostera in Plymouth waters is very smalLin.comparison with that in the Danish fjords and the detritus found here, though considerable in quantity, and in appearance much as described by Petersen, must originate largely from other sources. The possible1 sources of origin apart from land-sources are the coastal Algse and the plankton. A consideration of the annual production of each of these' suggests that the plankton is the more important factor.

4. Blegvad has classified marine animals according to their food into Herbivores, Carnivores, and Detritus-eaters, but this classification does not fit the conditions in the area here studied and is not therefore of general application. Herbivores are absent from these grounds, and few of the animals could be described strictly as detritus-eaters. The animals fall into the following natural groups, according to their food and the mode and location of their feeding:—

A.Carnivores—Animals which feed mainly upon other animals, either living or as carrion.

B.Suspension-feeders—Animals which feed by selecting from the surrounding water the suspended micro-organisms and detritus.

C.Deposit-feeders—Animals which feed upon the detritus deposited on the bottom, together with its associated micro-organisms.

5. Following the preceding classification the food of the common animals of the Plymouth fishing-grounds has been described briefly.
Water Movement and Sea Temperature in the English Channel
Authors: Harvey H. W.
Published: May 2009

During the last three years further evidence has been obtained that water of relatively high salinity, from the Atlantic to the south-west of the entrance, enters the English Channel past Ushant (1).

It is of interest to summarize this evidence in view of the suggestion (2) that the English Channel is cut off from the Atlantic for considerable periods.

The surface samples of very high-salinity water, collected in the Channel by the Ministry of Agriculture and Fisheries, suggest the possibility of masses of oceanic water moving into the Channel past Ushant from time to time; and they further suggest that this oceanic water divides in the western end of the Channel, one part moving direct into the North Sea, through Dover Straits, and the other part turning and passing out northward between Land's End and the Scillies. This is discussed by Mr. J. R. Lumby (see p. 670 of the present number of this Journal).
The Water Movements in the Neighbourhood of the English Channel—North Sea Junction. Drift Bottle Experiments.
Authors: Carruthers J. N.
Published: May 2009

The following short paper is based upon the results of very extensive experiments made with both surface-floating and bottom-trailing drift bottles, by the Ministry of Agriculture and Fisheries during 1920–21.
A Note on the Water Movements in the English Channel and Neighbouring Seas, considered on the Basis of Salinity Distribution.
Authors: Lumby J. R.
Published: May 2009

Comparison of the conceptions which have hitherto been held in regard to the hydrography of the English Channel with those which are offered as a result of the recent activities of the Atlantic Slope Committee, shows that a difference exists which, in the writer's opinion, lies in the interpretation of the material, rather than in the fundamental differences in the material itself. For example, it is stated that the physical character of the water in the English Channel is conditioned, especially in the summer months, by that of the North Sea water rather than by that of the Atlantic water. “En plein été, en août, les eaux chaudes de la mer du Nord affluent dans la Manche.” A similar regimen is suggested for the waters of the Irish Sea, which are said to be derived from the northward. Carruthers shows that the normal water movement in the eastern part of the English Channel is through Dover Straits into the Southern Bight, this movement appearing to be more persistent along the bottom than on the surface. Furthermore, one of the two months in which reversal of this direction appears least likely to occur is August.
A Releasing Apparatus for Horizontally Towed Plankton Nets
Authors: Russell F. S.
Published: May 2009

While experimenting on the vertical distribution of plankton in comparatively shallow waters I found it necessary to devise a releasing apparatus for use with horizontally towed plankton nets. Under existing working conditions there were four circumstances for which the instrument had to be adapted:
Seasonal Changes in the Water and Heleoplankton of Fresh-water Ponds
Authors: Atkins W. R. G. , Harris G. T
Published: May 2009

The seasonal changes in the heleoplankton of two fresh-water ponds have been compared with alterations in the solutes, and it has been shown that in each there was a vernal rise in pH followed by a period of stagnation with lowered pH. In the quarry pond of Borough Farm, Antony, this condition persisted till the autumn; in Staddon reservoir it was succeeded by a period of high alkalinity, lasting till October. These changes are associated with the spring increase in plankton, and the development of masses of floating algæ in Staddon reservoir; they may be traced in Figs. 1 and 3.
The biology of Limacina retroversa
Authors: Morton J. E.
Published: May 2009

The Plymouth Fauna List contains records of two genera of pteropods, Limacina and Clione. Of the first, Limacina retroversa (Flem.) is by far the better-known species, apparently occurring regularly at Plymouth in large numbers in townettings from outside, and sometimes inside, the Sound. It breeds at Plymouth from June to August, and Lebour (1932) has given a detailed account of its breeding and larval stages and has discussed its role in the plankton. The second species of Limacina at Plymouth is lesueuri (d'Orbigny), which has been observed from time to time since 1906, when it was very common. The last record in the Fauna is off the Breakwater in 1920. Of the gymnosomatous pteropods, Clione limacina Phipps is the only species regularly occurring. Lebour (1931) has described the life history of this form, and mentions February to August as its months of greatest abundance. Its breeding season is June to August. Another gymnosome, tentatively referred to as Clionina longicauda, is reported by Russell (1936), and from the specimen department at Plymouth Laboratory the writer obtained some preserved specimens, not easily identifiable, of a Pneumodermopsis taken locally; its species is perhaps ciliata, recorded by Massy (1917) from the Irish Coast.
Notes on the Didemnidae (Ascidiacea). III. A Comparison ofDidemnum maculosum, D. candidum, D. helgolandicum, andTrididemnum alleni
Authors: Carlisle D. B.
Published: May 2009

When Michaelsen (1923) described a species of didemnid from Heligoland, he stated that it was very similar toLeptoclinum maculosumMilne Edwards (1841), so far as may be judged by external appearance, but since no adequate description of this latter existed he proposed to call his Heligoland form by a new name,Didemnum helgolandicum, rather than use an old name which might well be wrong. Neither Michaelsen nor Hartmeyer, who described further details ofD. helgolandicum(1924), was able to compare it directly with specimens ofD. maculosumfrom the Channel coasts whence it was first described by Milne Edwards. Through the kindness of the directors of the Zoological Museum of Copenhagen and of the Biological Station of Roscoff I have been able to obtain specimens of both these forms and to compare them with specimens collected around Plymouth and on the coast of North Wales, and with specimens ofD. candidumSavigny, collected at Naples, and from the Red Sea, and ofTrididemnum alleniBerrill, collected around Plymouth.
Notes on the Didemnidae (Ascidiacea). IV. The increase of Trididemnum niveum (Giard) In the Plymouth area, and the structure of its larva
Authors: Carlisle D. B.
Published: May 2009

Since I first found Trididemnum niveum (Giard) at Salcombe in the autumn of 1951 (Carlisle, 1953) this species has spread and increased greatly in the Plymouth area. I have found it in abundance at Salcombe (Castle rocks and the Salstone), Wembury, and especially at Looe around the Island. The favourite habitat at all these places is the same as that at Roscoff, on the fronds of Cystoseira. It occurs rather less frequently on the holdfasts of Laminaria ochroleuca and occasionally on other species of Laminaria, but very little on any other substrate. It is not truly intertidal; the majority of specimens are to be found just below low-water mark of spring tides, and very rarely are any seen above low-water mark of even the lowest tides of the year.
Note on the Plymouth ‘Nitzschia’ Culture
Authors: Hendey N. Ingram
Published: May 2009

For nearly fifty years a small marine organism has been cultured at the Marine Biological Association's Laboratory at Plymouth, mainly to be used as a food supply in rearing marine larval forms.

The cultures were originated by the late Dr E. J. Allen in 1907. The first record of these cultures and the methods used to maintain them were published by Allen & Nelson (1910) in a paper describing methods for obtaining persistent cultures of eighteen species of plankton diatoms. One of these cultures flourished so successfully that subcultures have been distributed to many laboratories and institutions both in Europe and America. This organism was named Nitzschia closterium W. Sm. forma minutissima. The authors, however, did not describe the organism or produce an illustration, so the combination can be considered only as a nomen nudum.
Biological differences between sea waters: experiments in 1953
Authors: Wilson Douglas P. , Armstrong F. A. J.
Published: May 2009

The experiments during the 1953 season were arranged to investigate certain criticisms and suggestions made to us after publication of the earlier work (Wilson, 1951; Wilson & Armstrong, 1952), and there were included tests of our own devising intended to narrow the field within which must be made any search for an explanation of the observed biological differences between sea waters from different localities. We were again unable to obtain water from the Celtic Sea and once more, by kind co-operation of the Millport Marine Station, used water from the Firth of Clyde instead. Both the E1 and Clyde waters were collected on the same day and the fertilizations of Echinus esculentus were made and the experiments started 4 days later, which was the minimum time possible after collection of the Clyde water. Every experiment included a control comparison of the two waters.
The development of the ascidian Pyura microcosmus (Savigny)
Authors: Millar R. H.
Published: May 2009

Several recent papers have dealt with the development of members of the ascidian family Pyuridae (Hirai, 1941; Berrill, 1948; Millar, 1951; Sebastian, 1953), but the total number of species with known larvae is still only five, in spite of the large size of the family.

The present paper deals with the embryonic development, the larva, and the post-larval development of Pyura microcosmus (Savigny).
The vapour pressure and osmotic equivalence of sea water
Authors: Robinson R. A.
Published: May 2009

Sea water is a complex solution in which the principal ions are sodium, potassium, calcium, magnesium, chloride and sulphate. The vapour pressure (V.P.) of such a solution can be calculated approximately by making the assumption that each salt contributes to the vapour pressure lowering in amount proportional to its concentration, but such a calculation would ignore the interactions between the various ions. The theory of these interactions has been worked out only for very dilute solutions and it is, therefore, better to rely on direct experimental determinations. Measurements have now been made by the isopiestic vapour-pressure method (Robinson & Sinclair, 1934), in which samples of sea water are equilibrated with sodium chloride solutions until they have the same vapour pressure. The results are expressed in terms of chlorinities of sea water and molalities (moles per kilogram of H2O) of sodium chloride solution which have the same vapour pressure. It is hoped that the results will be of use to physiologists who have occasion to make up salt solutions equivalent to sea water.
A comparative study of the British species ofNuculaandNuculana
Authors: Allen J. A.
Published: May 2009

The survey of the sublittoral fauna of the Clyde Sea Area from 1949 onwards has shown that five species of the Protobranchiata are abundant throughout this region on a variety of substrata. Pelseneer (1891, 1899, 1911), Heath (1937), and Yonge (1939) have contributed much to the knowledge of the group as a whole, but little comparative work has been done at species level. Verrill & Bush (1897, 1898) studied the shell characters of the American Atlantic species. Moore (1931a, b) worked on the faecal pellets of the British Nuculidae and attempted to distinguish the species by this means, while Winckworth (1930,1931), mainly in the light of the latter work, attempted to clarify the nomenclature of these species. Winckworth (1932) lists six British species of the family Nuculidae:Nucula sulcataBronn,N. nucleus(Linné),N. hanleyiWinckworth,N. turgidaLeckenby & Marshall,N. mooreiWinckworth andN. tenuis(Montagu); and four species of the family Nuculanidae:Nuculana minuta(Müller),Yoldiella lucida(Loven),Y. tomliniWinckworth andPhaseolus pusillus(Jeffreys). All species ofNucula, exceptN. hanleyi, were taken from the Clyde Sea Area, although the latter species is included in the Clyde fauna list (Scott Elliot, Laurie & Murdoch, 1901). OnlyNuculana minutaof the Nuculanidae has been taken on the present survey.Yoldiella tomliniis included in the 1901 list but is noted as being ‘insufficiently attested’.Nucula hanleyiwas obtained from the Marine Station, Port Erin, butYoldiellaandPhaseoluswere unobtainable.
The abundance ofOctopusin the English Channel
Authors: Rees W. J. , Lumby J. R.
Published: May 2009

During 1950, the Common Octopus (Octopus vulgarisLamarck) was to be found along the south coast of England in greater numbers than at any time since Garstang (1900) reported on the ‘plague’ on the coasts of Devon and Cornwall in 1899–1900.

In earlier papers (Rees, 1950, 1952) the distribution of the octopus in our northern waters was reviewed, and it was demonstrated that this species is an immigrant which breeds on our south coast only rarely. It reaches these coasts by being brought there as a planktonic larva by the water circulation in the English Channel and by migrations of the adult. The most important factor in controlling the movements of the adult, however, might be expected to be the water temperature in the English Channel—where the species is at the northern limit of its breeding range and might therefore be extremely sensitive to slight changes in temperature.
On the behaviour of barnacles II. The influence of habitat and tide-level on cirral activity
Authors: Southward A. J.
Published: May 2009

During a study of the relation between temperature and cirral activity of barnacles, reported in Part I of this series (Southward, 1955), specimens for investigation were collected from those habitats and tide-levels where the particular species was most abundant. However, it is possible that some variation in behaviour may arise from local environmental factors such as tide-level and degree of exposure to wave action, and experiments were carried out to test this possibility.
The cyphonautes larvae of the Plymouth area and the metamorphosis ofMembranipora membranacea(L.)
Authors: Atkins D.
Published: May 2009

Several cyphonautes larvae (Polyzoa Ectoprocta) have been distinguished and described (Lohmann, 1911; Marcus, 1940; Thorson, 1946), but few have been seen to metamorphose, thus Unking the late larva with the adult. Three, belonging to the suborder Cheilostomata, which have been observed to do so, areCyphonautes compressusintoElectra pilosaL. (Schneider, 1869; Barrois, 1877; Kupelwieser, 1905–6),Cyphonautes occidentalisintoMembranipora villosa, (Robertson, 1908; O'Donoghue, 1927) and an unnamed cyphonautes intoNichtina( =Membranipora)tuberculata(Hastings, 1929, pp. 706–7).
The comparative external morphology and revised taxonomy of the British species ofIdotea
Authors: Naylor E.
Published: May 2009

This paper aims at describing the external morphology of seven British species ofIdoteafrom the functional and developmental aspects, thus revising earlier descriptions, such as those of Collinge (1917), which were based largely on adult specimens. Limitations of earlier descriptions are apparent, but some characters can be sifted from the older literature and combined with characters emphasized in this paper to give a schematic description of the seven species.
An improved ‘vacuum’ grab for sampling the sea-floor
Authors: Holme N. A.
Published: May 2009

The sampler to be described takes a small unstratified sample of the sea-bed, the sample being subject to a minimum of loss while being brought up. Such samples are of use in survey work, or for studies on grade size, mineralogical composition, chemical properties, or microfauna and flora of the deposits.

Although core-samples, in which the original stratification is retained, can be taken in soft muddy sediments without difficulty, it is not at all easy to take cores of sand or gravel. On such deposits an unstratified sample may be the best that can be obtained. Coarse sediments may be sampled by a dredge fitted with canvas bag, but when a small sample is required quickly, a light instrument which can be lowered vertically from the ship on a rope or hydro-graphic wire is needed. ‘Snapper’ samplers do not always take a satisfactory sample as the jaws may be prevented from closing by a pebble or shell wedged between them, much of the sample being lost while hauling up (cf. Stetson, 1938, p. 7). Stetson describes an instrument which takes a small semicircular core of sediment, the sample being sealed in the coring tube while being brought up, so preventing any loss of material. While no doubt taking good samples, the instrument is rather heavy (57 kg) and complicated in construction.
Plant production on the Fladen ground
Authors: Steele John H.
Published: May 2009

The quantitative study of phytoplankton production may be pursued in many ways, but these ways can be divided into two general methods of approach. There is, first, the direct estimation of a production rate for a particular sample of the population; for example, the light-dark bottle technique for measuring oxygen production (Gaarder & Gran, 1927; Riley, 1939) and the new 14C technique (Steeman Nielsen, 1952). These estimates are made under conditions which must be, to some extent, artificial. Secondly, there is the direct estimation of relevant variables in the sea (phosphate, oxygen, chlorophyll concentration, etc.) from which production is calculated on the basis of hypotheses about the behaviour of phytoplankton. These hypotheses are, of necessity, simplifications of a mass of laboratory experiments and of previous field work. Riley, Stommel & Bumpus (1949) give a full account of this approach and of the difficulties involved in it.
The abnormal development of plaice embryos and larvae in marine aquaria
Authors: Shelbourne J. E.
Published: May 2009

We know that a mature female plaice can liberate many thousands of eggs into the sea during the spring spawning season in the southern North Sea (Simpson, 1951). We also know that a very small percentage indeed of these eggs develops into fish of marketable size. At all stages in its life history a plaice is con-fronted with environmental hazards, which, if not overcome, may have fatal consequences.
Neurohormones of invertebrates: I. Cardio-regulators of Cyprina and Buccinum
Authors: Welsh John H.
Published: May 2009

The present study had two aims: first to seek among the molluscs of the Plymouth region, one with a heart suitable for the bioassay of acetylcholine and 5-hydroxytryptamine; and secondly, to examine moUuscan nervous tissue for the presence of cardio-regulator substances. Brief reports of some of the results have appeared elsewhere (Welsh, 1953a, 1954a).
A record of plankton on the echo-sounder
Authors: Cushing D. H. , Richardson I. D.
Published: May 2009

A number of records from echo-sounders have been loosely attributed to the presence of plankton. Only two records have been adequately identified as having been produced by plankton; first, the traces offish larvae, or shallow scattering layers (Burd & Lee, 1951); and secondly, the echo layer, at the depth of the temperature discontinuity or thermocline, which is sometimes associated with plankton animals or plants (Cushing, Lee & Richardson, in press). A third type of record, that from the ‘deep scattering layer', has been associated with the presence of euphausiids (Hersey & Moore, 1948; Moore, 1950; Boden, 1950): an equally plausible association with the presence of fish has been made by Marshall (1951), Tucker (1951) and Hersey & Backus (1954). A fourth type of echo record, a ‘noisy’ record, will be described and will show that it is probably attributable to plankton organisms, consisting, in one instance, of euphausiids.
Filtering, feeding, and digestion in the lamellibranch Lasaea rubra
Authors: Ballantine Dorothy , Morton J. E.
Published: May 2009

Lasaea rubra is the smallest and commonest of Plymouth bivalves. It is intertidal on rocky shores, often in immense numbers, in crevices and other protected places, and in Pygmaea pumila (Colman, 1940). This bivalve is an excellent laboratory animal. It remains fully active for several days under laboratory conditions, and a large number of animals can be used in a single experiment, eliminating the variations in activity found when dealing with a few, or single specimens of larger animals. Because of the relatively high position Lasaea rubra may occupy on the shore its feeding cycle is broken by regular dry periods at each tide. Thus, for experiments relating to periodicity in feeding, we have an animal whose times of feeding can easily be ascertained and experimentally varied over a wide range. Lastly, in making serial sections and in examining total gut contents, in work on the digestive system, the small size of the animal is of obvious advantage.
The effect of water conservation on the structure of marine fish embryos and larvae
Authors: Shelbourne J. E.
Published: May 2009

Fish eggs can be divided into three main groups: marine pelagic eggs which float of their own accord, marine demersal, and freshwater demersal eggs. The embryological development of freshwater teleosts follows an accepted pattern, demonstrated by morphologists during the nineteenth century. Marine embryos, both pelagic and demersal, do not conform in all respects to this pattern, and misunderstandings have frequently arisen by lack of attention to known structural differences between the three groups. Mclntosh & Prince (1890), in their comprehensive review offish development, emphasized some outstanding anomalies in pelagic structure, but gave no adequate explanation of their occurrence.
Notes on Experiments in the Keeping of Plankton Animals under Artificial Conditions
Authors: Crawshay L. R.
Published: May 2009

The experiments referred to in the following pages were carried out by the wish of the Director at the Plymouth Laboratory, between June, 1912, and February, 1913. They were undertaken with a view to keeping under observation some of the smaller zooplankton, and particularly the Copepoda, in order that they might be followed through the different stages of their life cycle. After a long series of disappointing results, the experiments were unavoidably interrupted at a time when apparently the chief obstacles to success had been located and largely overcome.
Twin Gastrulæ and Bipinnariæ of Luidia sarsi, Düben, and Koren
Authors: Gemmill James F.
Published: May 2009

Early in June of this year (1914) I received from the Plymouth Marine Laboratory through the kindness of Dr. E. J. Allen, F.r.s., several Thermos flasks containing quantities of a culture of Luidia in the early blastula stage. This culture was made for me by Mr. James Gray, King's College, Cambridge, to whom, and to Dr. Allen, I desire herewith to express my indebtedness. The larvæ were little the worse of the journey to Glasgow, but it seemed to me that they showed even greater irregularities of form than might have been expected from Mortensen's (13) description of blastula formation in our species. However, in the end, abundance of perfectly typical young bipinnariæ were secured from the contents of the various flasks. The abnormal larvæ became gradually fewer through death, and those which survived could be isolated without much trouble, since they exhibited less capacity for keeping near the surface of the water than their healthier brethren. A great many of the early malformations were of the nature of double or twin formation, and it soon became evident that the teratological type in question, namely, double monstrosity, was about to receive a more varied expression, and to attain a more advanced stage in development, than it had ever before been my good fortune to find in any starfish culture.

In the accompanying illustrations two series of abnormal larvæ are figured, one at the gastrula stage (Figs. 1–11), and the other at that of the early bipinnaria (13–21). As a description is appended to each figure, only questions of general interest need be dealt with here.
Experimental Legislation with Reference to the Crab and Lobster Fisheries of the East Coast of Britain
Authors: Meek Alexander
Published: May 2009

So large a demand has been made for copies of the recently published paper on the effects of legislation on the crab fisheries of the East Coast that a new paper is necessary. A summary is given of the previous paper and the figures have been reproduced. For convenience of reference they are arranged and numbered as before. The opportunity has been taken to give a review of the attempts to improve the lobster fisheries by legislation.
The Vertical Distribution of Marine Macroplankton. An Observation on Diurnal Changes
Authors: Russell F. S.
Published: May 2009

INTRODUCTION.

1. A series of hauls with the ring-trawl were made at five depths in water 50 metres deep, so that samples were obtained approximately in daylight, at dusk, at midnight, at dawn, and again in daylight.

A depth-recorder was used with the net giving a graphic record of its path through the water.

2. Examination of the catches demonstrated the diurnal changes in vertical distribution of the species caught by the ring-trawl.

3. Four types of behaviour were shown:—

(a) A definite migration to the surface in the dark hours of certain forms living in the deeper layers in the daytime.

(b) An expanding of the distribution of other organisms, that in the daytime had a zone of maximum abundance in the deeper layers, so that they were evenly scattered from the surface downwards.

(c) Certain animals showed no or very little change in their vertical distribution during the dark hours.

(d) A movement up to the midwater region by those forms that during the daytime adopt either a truly benthic existence or are congregated in the water layers immediately adjacent to the sea floor.

(Lists of species grouped under their respective types of behaviour are to be found on page 780.)

4. Many such observations are required before conclusions can be drawn as to the normal diurnal behaviour of plankton animals: this is a definite record of what occurred in this locality in mid-July at a period of full moon in fair weather.