bluuebunny/crossref_metadata_2025 huggingface dataset:
On Anthura gracilis (Montagu)
Authors: Sexton E. W.
Published: May 2009

On August 14th, 1913, a fine male specimen of Anthura gracilis was taken by the Oithona, in the young-fish trawl working at the surface at night, about six miles west of the Eddystone.
On the Occurrence of Aphroceras (Leucandra) cliarensis Stephens near Plymouth
Authors: Dendy Arthur
Published: May 2009

In July, 1912, a paper was published in the Proceedings of the Royal Irish Academy (Vol. XXXI) on the Marine Porifera of Clare Island, by Miss Jane Stephens, in which the authoress gives an excellent account of a new species of Calcareous Sponge, Leucandra cliarensis. In April of the same year I happened to be working at the Marine Laboratory at Plymouth, and my friend Mr. Orton brought me several specimens of a very pretty little calcareous sponge just collected by him at Wembury Bay. I was too much occupied with other work to examine these carefully at the time, but simply preserved them in spirit. Recently I have examined them in detail, and find, curiously enough, that they belong to the species described by Miss Stephens from Clare Island on the west coast of Ireland.
Note on Two Unrecorded Plumularian Hydroids from the Plymouth Area
Authors: Ritchie James
Published: May 2009

Confusion has reigned in the works of British authors as to the relationship between Plumularia catharina, Johns., and a more simple form, with unbranched stem, found, like the former, on many parts of the coast. Johnston and Hincks, and the majority of their successors, have recorded the simple form, where it was thought worthy of mention, as a “stemless variety” of the former; but examination of the type specimens of P. catharina in the British Museum has proved that a fundamental distinction exists between the two forms. P. catharina is a branched species and bears on each side of a hydrotheca a pair of lateral sarcothecce; the other is a branchless, bristle-like form, bears on each side of a hydrotheca a single lateral sarcotheca, and has been long known as Antenella (or Plumularia) secundaria (Gmelin).
On Ciliary Mechanisms in Brachiopods and some Polychætes, with a Comparison of the Ciliary Mechanisms on the Gills of Molluscs, Protochordata, Brachiopods, and Cryptocephalous Polychætes, and an Account of the Endostyle of Crepidula and its Allies.
Authors: Orton J. H.
Published: May 2009

The results of the writer's investigations on the ciliary mechanisms on the gills of Mollusca and Amphioxus (1 and 2) gave rise to the suggestion that similar mechanisms might probably also occur in Brachiopods, for it is a well-known fact that Brachiopods—like some Molluscs and Amphioxus—feed on the smaller organisms which are to be found floating in the sea. Owing to the kindness of Dr. H. C. Williamson, of Aberdeen, I have been able to examine living Crania which were obtained by dredging in Loch Fyne, and living Terebratula have also been obtained from Naples. An investigation of the living gill-filaments—or lophophoral cirri, as they are frequently termed in this group—showed that the ciliary mechanisms on these filaments are essentially the same as those occurring on the gill-filaments of Amphioxus, Lamellibranchs, some Gastropods, and most Ascidians. As it was found that existing accounts of the mode of feeding in Brachiopods are vague and incomplete the following description of the process has been written.
Preliminary Account of a Contribution to an Evaluation of the Sea
Authors: Orton J. H.
Published: May 2009

An investigation of the rate of growth in Marine Invertebrates was begun in 1911, and a large amount of material the age of which is known has now been collected from various sources. The particular objects of this research are: (1) to establish the age of common marine invertebrates, (2) to determine the minimum age at which these forms begin to breed, (3) to examine the rate of growth at different seasons of the year and under different conditions, (4) to investigate the fecundity of different forms so far as possible, and (5) to collect the scattered literature on these subjects.
General Report on the Larval and Post-Larval Teleosteans in Plymouth Waters
Authors: Clark R. S.
Published: May 2009

The material on which the present report is based was collected by the Oithona from 1906 to 1909 inclusive, and during the latter half of 1913. Attention was directed particularly to the capture and determination of the post-larval fishes. The investigations during the first four years were carried out by Mr. A. E. Hefford, and his notes have been fully relied upon for the identification of the species. For the collecting and working out of the 1913 material I am directly and wholly responsible.
The Vertical Distribution of Marine Macroplankton. III. Diurnal Observations on the Pelagic Young of Teleostean Fishes in the Plymouth Area.
Authors: Russell F. S.
Published: May 2009

Results are given of collections made with the stramin ring-trawl to study the vertical distribution of post-larval teleostean fishes throughoutthe period from daylight, through the hours of darkness, to daylight on July 15th-16th, 1924, and June 17th, 18th, and 19th, 1925. At the time of collecting in July, 1924, it was full moon ; in June, 1925, there was no moon.

In no case, except perhaps that of Sardina pilcliardus post-larvse, was there evidence of marked upward migration at night ; the general impression for most species was that while the type of distribution shown in daylight was somewhat modified at night, only very few individuals moved up to the surface layers. There was, however, a notable increase in numbers of certainspecies at all depths at night, whether this was an indication of a movement up from layers very close to the bottom is not known ; it will need many more observations before the exact significance of this can be fully understood.

The numbers of post-larvae taken were in the case of most species unfortunately very small on all occasions; it is not possible, therefore, to come to very definite conclusions.

A possible indication of the effect of moonlight was shown by the post-larval Callionymus lyra, for while in July, 1924, at the time of full moon they showed no upward movement at night, in June, 1925, with no moon a certain proportion reached the surface layers.
A General Survey of Larval Euphausiids, with a Scheme for their Identification.
Authors: Lebour Marie V.
Published: May 2009

Whilt working at the life histories of the euphausiids occurring in the English Channel, and also having had opportunities of examining the larvae of several other species belonging to different genera from various localities, the writer noted certain features in the larvae which usually enabled the genus to be distinguished easily. The chief specimens were obtained from plankton collected by Mr. F. S. Russell within a radius of twelve miles from Alexandria, Egypt, whilst working for the Egyptian Fisheries Department. The larval euphausiid material from this collection is rich, and an account of it will soon be published. In the meantime the following general notes are offered, as at present little is known of the systematics of euphausiid larvæ. As several workers are occupied with this group, so important from the point of view of the Fisheries, it seemed advisable to bring all that is known together. In so doing it has been found possible to form a working scheme, from which, being given a series of larvæ of any species, one is enabled to determine the genus. For this scheme the order of development of the pleopods has been taken as the main factor, as it is found that the pleopods develop differently in several of the most important genera.
A New Method for Quantitative Sampling of the Sea-bottom
Authors: Hunt O. D.
Published: May 2009

The apparatus described in this paper has been specially designed for the taking of samples in cases where it is important that the finer constituents of the sample should be adequately retained. In commencing a study of the micro-fauna and micro-flora of the sea-bottom near Plymouth the writer found that, in samples taken by the “Petersen” (2) 1/10 sq. metre bottom-sampler, or by the, conical dredge, the silt and finest material was liable to be washed away to a variable and non-measurable extent while hauling the apparatus. Quantitative observations on very small organisms were judged impossible by these methods and attention was directed towards devising an apparatus which would retain the finer portions of the deposits.
Some Marine Ciliates Living in the Laboratory Tanks at Plymouth, with a description of a New Species,Holophrya coronata.
Authors: De Morgan W.
Published: May 2009

The Ciliates described in this paper were mostly found living in the tanks at the Plymouth Laboratory, which are supplied with a constant circulation of sea-water from two large storage reservoirs. Most of them came from a large shallow tank standing in front of a south window, which is referred to in the paper as “Drake's Island Tank.”
Young Anglers In Captivity and some of their Enemies. A Study in a Plunger Jar
Authors: Lebour Marie V.
Published: May 2009

It is only very rarely that the spawn of the Angler Lophius piscatorius is captured near Plymouth, although it has been recorded (Cunningham, 1896). It is well known that it consists of a gelatinous ribbon several yards long and a yard or more wide, with the eggs (over a million) in one layer divided from one another by roundish capsules. It is probable that the Angler spawns well out to sea, for when these ribbons of eggs have been captured anywhere near the coast the larvae have nearly always already hatched and are lying loose in the capsules (Bowman, 1919). Moreover, most of the spawn caught inshore consists of portions only of the ribbon which have probably drifted towards the coast.
Obisium maritimum Leach found at Wembury, near Plymouth, together with its Original Description, and short notes on its Geographical Distribution
Authors: Barnes H. F.
Published: May 2009

While carrying out a general examination of rock crevices and their fauna, making the best advantage of a specially low tide on March 24th, 1924, at Wembury, near Plymouth, the writer was very pleased to find a single specimen of Obisium maritimum Leach. Several fissures in rocks between high and low tide marks were split open with a hammer and chisel, revealing large numbers of Anurida maritima, together with a Coleopteron, Aepus sp., Acari, and a few Collembola. It was after splitting one such fissure that a single specimen of Obisium maritimum Leach was found in company with Anurida maritima in large numbers, and a few Acari and the Coleopteron. Although a thorough search was made both at the same time and at a later date, no further specimens were found. On splitting the rock the O. maritimum, rushed backwards and forwards in an attempt to conceal itself in some crevice. The particular rock was covered with weed which it was necessary to lift up in order to reveal the crevices, and was situated a few yards from extreme spring low tide mark.
On a Hermaphrodite Specimen of Amphioxus with Notes on Experiments in Rearing Amphioxus
Authors: Orton J. H.
Published: May 2009

A hermaphrodite specimen of Amphioxus has been taken at Plymouth having one gonadial pouch filled with ova and the remaining pouches filled with sperm. This specimen closely resembles a similar one taken by Goodrich at Naples.

The liver and intestine of the Plymouth specimen are abnormal, but no parasites have been identified in the tissues to account for these abnormalities.

It is, moreover, improbable that there is any normal sex-change in Amphioxus, since three independent investigators have found very small specimens of both sexes, therefore no satisfactory explanation can be given of the occurrence of hermaphroditism in the specimen.

Amphioxus have been found to spawn in June, and larvae have beenobtained from the captive specimens.It is suggested that the club-shaped gland may secrete a substance for attaching the larva of Amphioxus to objects, and that this function may be correlated with the asymmetry shown in the early development of the Amphioxus .larva.
Styela mammiculata n.sp., a new species of ascidian from the Plymouth area
Authors: Carlisle D. B.
Published: May 2009

Styela mammiculata n.sp. is based on four specimens collected in the Plymouth area during the summer of 1953. The most noticeable external feature is the extensive mammillation of the test. The mammillae are much smaller than those of Phallusia mammillata and deserve to be called rather ‘mammiculae’.

Of the four specimens, two were taken from Drake's Island buoy (National Grid Reference, 20/4753)m Plymouth Sound, growing about half a metre below the water line, and two from the oyster bed of the Lynher river estuary, near Antony Ferry (National Grid Reference, 20/4257), growing about 12 m. below low-tide mark attached to oyster shells. The largest specimen was from the latter locality and measured III mm. long in the contracted, fixed condi- tion. The smallest, from Drake's Island buoy, was 54 mm. long.
Phosphorus and silicon in sea water off Plymouth during the years 1950 tO 1953
Authors: Armstrong F. A. J.
Published: May 2009

The analyses reported here refer to water from International Hydrographic Station E I (lat. 50° 02′ N., long. 4° 22′ W.). They extend the sequence begun in 1923 when sufficiently sensitive chemical methods were first applied at this station (Atkins, 1923 a), and reported thereafter in a series of papers from this Laboratory (Atkins, 1923a, b, 1924, 1926a, b, 1928, 1930, 1953; Cooper, 1933a, b, 1937, 1938; Harvey, 1948, 1950; Armstrong, 1951; Armstrong & Harvey, 1950). This is a factual report and interpretation and comparison with earlier years are deferred.
Hatching in Calanus finmarchicus and some other copepods
Authors: Marshall S. M. , Orr A. P.
Published: May 2009

During observations on the development of the eggs of Calanus finmarchicus the process of hatching was watched on many occasions. Since it differs from that described by Ziegelmayer (1926) for cyclopids it seemed worth while examining the process in other groups of copepods as well.

Hatching can be followed very easily in Calanus (Pl. I). For some time before, the form of the nauplius can be clearly seen with its limbs folded close to the body (A); in many a red pigment spot develops at this time in the otherwise transparent egg. Shortly before hatching the limbs begin to twitch occasionally and a space is just visible round the body of the nauplius. At this stage the inner and the outer egg membranes cannot be distinguished, but when hatching begins, the outer membrane must crack for the delicate inner membrane bulges out (B). The bulge enlarges rapidly (c), and the nauplius extends into the bulge, sometimes leaving a clear space between itself and the membranes (D). Usually it is either the head or the tail end which pushes into the bulge, but occasionally it is a limb. Probably it is abnormal for a limb to extrude first since such eggs do not always hatch successfully. As the inner membrane expands, the outer slips back and the inner, enclosing the nauplius, pops out (E). This emergence often occurs suddenly, but sometimes it is gradual (as in E), when the outer membrane crumples up on the inner, regaining its original shape only when the inner has slipped out and the tension is released (F).
Experimental observations on the vertical migrations of plankton animals
Authors: Hardy A. C. , Bainbridge R.
Published: May 2009

Much information concerning the vertical migration of plankton animals has been gained by using nets at different levels in the sea and at different times of the day and night, and also by experimenting with animals in apparatus of various kinds both in the laboratory and in the sea itself. Such observations and experiments have been summarized in the extensive reviews by Russell (1927) and Cushing (1951) who give full lists of references.
A note on the isolation of small marine algae and flagellates for pure cultures
Authors: Droop M. R.
Published: May 2009

Increasing interest in the comparative biochemistry of marine algae and protozoa is creating a demand for experimental material in the form of pure, i.e. bacteria-free, cultures. For nutritional and biochemical studies pure cultures are, of course, obligatory; but the number of marine strains available for this sort of work is lamentably small. Indeed, none of the so-called μ flagellates has hitherto been grown in pure culture as far as I know, although there exist pure strains of some of the larger and hardier forms.
A preliminary check-list of British marine diatoms
Authors: Hendey N. Ingram
Published: May 2009

The present list of diatoms may be considered an extension of the recent check-list of British marine algae by Parke (1953). It includes not only truly marine species, both sessile and planktonic, but also species inhabiting brackish waters with a few fresh-water species that manage to live, though somewhat precariously, in estuarine conditions.

It has been compiled for the following reasons: (1) to indicate the extent of the diatom flora around British coasts, so that comparisons may be made with that of the other countries; (2) to assist workers in the identification of material by indicating the size of any genus known to inhabit our shores; (3) to check the arrival of new entrants to the British flora; and (4) to provide a basis for a more detailed work, now in preparation. The check-list does not presume to lay down finalized decisions on the taxonomic rank ascribed to any organism or to consider the criteria upon which such ranks are based.
A suggested method for the assay of vitamin B12 in sea water
Authors: Droop M. R.
Published: May 2009

One of the difficulties encountered in the use of fresh water organisms for the assay of vitamin B12 of marine origin is the elimination of salt from the extracts. This has suggested that a marine organism might be used with advantage. Indeed on several occasions marine or supra-littoral species have been proposed as possible assay subjects, but acceptable techniques await development (Lewin, 1954; Droop, 1954; Sweeney, 1954). Monochrysis lutheri, a supra-littoral euryhaline species, has advantages over others in being small, robust and giving heavy yields in synthetic media. The method employed in some Monochrysis assays carried out in the early spring of 1954 will be described.
On the biology ofCalanus finmarchicusVIII. Food uptake, assimilation and excretion in adult and Stage VCalanus
Authors: Marshall S. M. , Orr A. P.
Published: May 2009

Apart from a few scattered observations (Hensen, 1887; Gran, 1902) the study of the food ofCalanusbegan with Dakin (1908). He examined the remains present in the gut, and this was the method used also by Esterly (1916), Lebour (1922) and Marshall (1924). They all found that these remains consisted of a greenish mush containing the skeletons of numerous planktonic organisms, chiefly diatoms and dinoflagellates. Naked flagellates were, how-ever, occasionally seen, and it was realized that the food might in reality consist largely of organisms which had no skeleton and could leave no recognizable remains.
The role of micro-organisms in the settlement of Ophelia bicornis Savigny
Authors: Wilson Douglas P.
Published: May 2009

During the course of earlier work with larvae of Ophelia bicornis Savigny it became increasingly clear that a major factor in stimulating these larvae to settle and metamorphose is the presence, on sand grains of suitable size, of living micro-organisms such as bacteria, in numbers neither too many nor too few (Wilson, 1954). It had been shown that an acid-cleaned sand (which is neutral or almost so) kept in sea water becomes increasingly attractive to these larvae with time. It had been admitted, however (loc. cit., p. 366), that these results were derived from a comparison of experiments not designed to this end, and that further tests, planned for the purpose, were desirable.
Hemimycale columella (Bowerbank): a short description and history of the species
Authors: Forster G. R.
Published: May 2009

These notes arise from the difficulty met with in identifying a pinkish encrusting sponge which has been frequently collected by hand from rocks at 5–10 fathoms. The sponge was at first identified, by a process of elimination, with the deep water genus Inflatella. Fortunately some preparations were shown to Dr Lévi at Roscoff to whom the species was at once familiar as Stylotella columella (Bowerbank). It was then found that this species had been described originally by Bowerbank from an Exmouth specimen, and subsequendy by Topsent from both south and west coasts of France. Topsent found the unusual, if not unique, character of this sponge in possessing, besides siliceous spicules, a great abundance of calcareous granules. These granules are almost certainly the ‘gemmules’ described and figured by Bowerbank. De Laubenfels in 1928 collected one specimen from Plymouth Sound which he identified as Stylotella columella; but proposed (1932) that the species should be included in the genus Prianos Gray. Burton in 1934 renamed the species Hemimycale columella, figuring the spicules as styles. Arndt (1935) returned to Stylotella and retained Burton's figure of the spicules. As the styles have been found, so far, only as a small minority amongst the spicules, it has been thought worth while to provide a further description; and to discuss the differing views on the systematic position of the species.
Blood perfusion of the kidney ofLophius piscatoriusL. IV. Magnesium excretion
Authors: Brull L. , Cuypers Y.
Published: May 2009

From our previous publications (Brull & Nizet, 1953; Brull, Nizet & Verney, 1953; Brull & Cuypers, 1954), it appears that the power of concentration of the aglomerular kidney ofLophiusis rather low, the density of the urine being usually less than that of the plasma concentration. Most individual urinary constituents do not reach concentrations that are more than once or twice those in the plasma, magnesium being an exception
The ecology of the Tamar estuary. VII. Observations on the interstitial salinity of intertidal muds in the estuarine habitat of Nereis diversicolor
Authors: Smith Ralph I.
Published: May 2009

The polychaete Nereis diversicolor F. O. Müller is one of the most characteristic elements of the brackish-water fauna of north-western Europe, and inhabits an extremely wide range of salinities. As a background for comparative physiological studies of chloride regulation in worms from different parts of the geographical range, the writer has attempted to describe the salinities and the variations in salinity endured by populations of N. diversicolor in eco-logically distinct and geographically well separated areas. Three principal environments have been studied:
Receptor elements in the muscles ofLeander serratus
Authors: Alexandrowicz J. S.
Published: May 2009

In continuation of the studies on receptor elements in the Crustacea the common prawn,Leander serratus, has been investigated by the methylene-blue method applied in the same way as described in an earlier publication (Alexandrowicz, 1951). It has been found that there are inLeanderreceptors of the same kind as in those crustaceans previously investigated, some of which exhibit features not yet observed before. As in other crustaceans they are similarly situated on the dorsal side of the body, but since a knowledge of the disposition of the dorsal muscles in the thorax and the abdomen is necessary for locating them, some data about the topography of the muscles are first given.
The Euphausiidæ in the Neighbourhood of Plymouth. II. Nyctiphanes Couchii and Meganyctiphanes noruegica.
Authors: Lebour Marie V.
Published: May 2009

The present paper is a continuation of last year's work on the Euphausiidæ in the neighbourhood of Plymouth (Lebour, 1924), in which the early larval stages were described of Nyctiphanes Couchii, Meganyctiphanes norvegica and, less fully, those of Thysanoessa inermis and T. neglecta. These two last-named forms are reserved for a detailed description in another paper, only Nyctiphanes and Meganyctiphanes being dealt with here. The first paper described these as far as the last Calyptopis stages, and it was shown that they were much alike although perfectly distinct, especially as regards colour. The nauplii and metanauplii were easily distinguishable. The whole of the remaining life-history of Nyctiphanes Couchii has now been elucidated and also that of Meganyctiphanes norvegica, with the exception of a few late larval stages. The absence of these, however, does not materially affect our knowledge of its life-history.
The Eggs and Newly Hatched Larva ofTypton spongicola O. G. Costa.
Authors: Lebour Marie V.
Published: May 2009

At the end of June, 1924, a female ofTypton spongicola, dredged by theSalpa, bearing eggs, was taken from the spongeDesmacidon fruticosusin which it lives, and given to me alive. This was placed in a Plunger Jar in the Laboratory, and on July 8th most of the eggs hatched out. The larvæ did not live long, and never sloughed the skin; but several were preserved, and the following notes on these are of interest, as very little is known of the development in the Pontoniinæ to which subfamily of the Palaemonidee in the Caridea, Typton belongs (Gurney, 1925). The female continued to live for some months at the bottom of the Plunger Jar without any sponge shelter. It ate any dead plankton, and was a useful scavenger. This is interesting, as its ordinary food is the Desmacidon in which it lives (Hunt, 1923).
On a New British Sea Anemone
Authors: Stephenson T. A.
Published: May 2009

It is a curious fact that the majority of the British anemones had been discovered by 1860, and that half of them, as listed at that date, had been established during a burst of energy on the part of Gosse and his collecting friends. Gosse added 28 species to the British Fauna himself. It is still more surprising that since Gosse ceased work, no authentic new ones have been added, other than more or less offshore forms, with the exception of Sagartia lucice; and this species appears to have been imported from abroad. There is, however, an anemone which occurs on the Breakwater and Pier at Plymouth, which has not yet been described. Dr. Allen tells me it has been on the Breakwater as long as he can remember, and to him I am indebted for the details of its habitat given further on. Whether it occurs elsewhere than in the Plymouth district and has been seen but mistaken for the young of Metridium dianthus, is as yet unknown.
On the Anatomy and Relationships of New or Little known British Actiniaria
Authors: Stephenson Mary
Published: May 2009

This paper contains anatomical descriptions of some British species whose systematic position has hitherto been uncertain because of the absence of detailed knowledge of their structure. To these descriptions are added notes on anatomical points of interest connected with other species.

Some of the facts gained have a general systematic bearing which will be pointed out as they occur in connection with the descriptions, or in the discussion at the end of the paper. I am indebted to Dr. Allen, Mr. W. Edgar Evans, Mr. E. Elmhirst, Miss M. Delap, and Dr. T. A. Stephenson for material, and to Dr. Esdaile for valuable guidance.
Muscle-Tumours in the European Turbot
Authors: Young Maxwell W. , Johnstone Jas.
Published: May 2009

In 1913 a successful attempt was made to introduce the European Turbot to New Zealand waters. On 12 January of that year 298 young fish, caught in the neighbourhood of Plymouth, and kept for some time at the Marine Biological Station, were put aboard the Waimana. Of these fish 195 were safely transported across the tropics, and were put into the tanks at the Portobello Marine Hatchery. The operation was a very successful one, thanks to the care of the late T. Anderton, who was then Curator of the hatchery.

The turbot were originally from one to two inches in length. It was intended to liberate most of them in the sea, but, on consideration, it was decided to keep them in captivity. Three years later (May, 1916) there were still 182 fish, 5 having died and 8 having been liberated in the sea. They grew very rapidly in the tanks, so much so that in May of 1916 many were about 18 inches in length. To keep these large fish healthy was difficult, and so, in 1916, 128 of them were liberated in Taukutu Bay.
Oxidation in Sea Water
Authors: Harvey H. W.
Published: May 2009

1. Putrefaction in sea-water sets free compounds toxic to Calanus. A portion of these compounds withstands oxidation to non-toxic forms in air saturated water for considerable periods.

2. “Deep water” from the English Channel contains a catalyst, probably an iron compound, which increases the rate of oxidation of a number of easily oxidisable organic compounds. Its action is inhibited in surface and inshore waters by dissolved organic matter.

3. Hydrogen peroxide decomposes relatively quickly in “deep water” from the English Channel, at a velocity corresponding to that of a monomolecular reaction. A catalyst, probably an iron compound, active towards hydrogen peroxide, occurs in sea-water. The action of the catalyst is inhibited by dissolved organic substances in surface and inshore water, until such substances are oxidised by the hydrogen peroxide.
On Rhythmic Periods in Shell-growth in 0. edulis with a Note on Fattening
Authors: Orton J. H.
Published: May 2009

Continuous observations on the Upper Fal Estuary oyster beds during the years 1925, 1926, and 1927 have established the fact that 0. edulis exhibits on these beds two definite periods of shell-growth, i.e. increase in shell-area, in one year; one period of general shell-growth occurs in the spring, beginning early in April, and the other in autumn at the end of September or early in October. There is some evidence-but as yet incomplete-that internal shell-growth occurs solely and simultaneously with the deposition and thickening of the new shell-shoots in a period of one to two months.

These general bursts of shell-growth occur in the pre-breeding and post-breeding part of the season

Similar periods of shell-growth occur on beds in the River Blackwater (AVest Mersea), and also occur mainly in the pre-breeding and postbreeding part of the season; but shell-growth begins in the spring in April-May on these beds, a few weeks later than on the Upper Fal Estuary,
and in the autumn in August-September a few weeks earlier than on the Upper Fal beds.

Spring and autumn periods of shell-growth are also known to occur on many other estuarine beds.
The Vertical Distribution of Marine Macroplankton. VII Observations on the Behaviour of Calanus finmarchicus
Authors: Russell F. S.
Published: May 2009

The vertical distribution of Calanus finmarchicus adults in the daylight in the Plymouth region as shown by stramin ring-trawl catches in described for the period April to September in 1926. The general results confirmed the indications given in 1925 that there is a, gradual descent of the region of maximum abundance from about 10 metres in April to-metres in June, with a definite rise towards the surface ia July, August, and September.

2. The rise towards the surface was evident on sunny days as well as dull, indicating that the suggestion that dull weather and low light intensity was its cause in 1925 may possibly have been incorrect.

Measurements of the total lengths of Calanus were made which showed a seasonal change, a brood of small adults occurring in July, August, and September, as opposed to a brood of large adults whichdominated in the spring.

It is suggested that possibly these two broods are physiologically different, and that the small type of adult prefers a higher light intensity and lives nearer the surface than the large type.

The males and females differed in their behaviour, the males being always slightly deeper in the water than the females.

Some indications are given of the course of the life-cycles of Calanus in the Plymouth area.

While from April to the end of June the abundance of the last copepodid stage (Stage V) rarely exceeded more than 20% of the total Calanus in any one catch, they became very much more abundant in July, August, and September, reaching even 60% and 70%.
Studies on Conditioned Responses in Fishes. Part I.
Authors: Bull H. O.
Published: May 2009

It has been shown by experiments formulated upon the conditioned response principle that the blenny, Blennius gattorugine, is able to perceive and to profit by very small changes in its environment. This fish is able to form conditioned motor responses using food as unconditioned stimulus, towards a momentary increase of 0-4C, or more, in the temperature of the surrounding water.

It is also able to form similar conditioned motor responses towards a momentary decrease in the salinity of the surrounding water, of as little as 3 parts per 1000, or towards a change of greater magnitude (up to 37 parts per 1000).

Conditioned responses have been established in the wrasses, Crenilabrus inelops and Labrus bergylta, towards visual stimuli of varying kinds. It appears that these fishes can discriminate after differential training between one or two sources of light, and between monochromatic red, green, yellow, or violet light, but not readily between even comparatively large differences in intensity of a luminous source. These results are those obtained upon dark-adapted fishes. More extensive experiments will be necessary before a final statement is made upon their capacity for colour discrimination.
The Larvæ ofPolydora ciliataJohnston andPolydora hopluraClaparède
Authors: Wilson Douglas P.
Published: May 2009

The developments of Polydora ciliata Johns, and Polydora hoplura Clap, are described from the egg to a very late planktonic stage in the case of the former, and to young metamorphosed individuals in the case of the latter. Only external characters are described.

In both species the eggs are laid in egg-sacs attached to the wall of the parent's burrow.

The larvae of P. ciliata are released at a stage with three chsetigerous segments and lead a long planktonic life.

The larvae of P. hoplura are provided with special food in the form of yolk-masses ; they undergo most of their development while in the protecting burrow of their parent; are released at a very late stage, and have only a short planktonic life.

The larvae of both species have a complicated vestibule surrounding the mouth, and are provided with special sensory cilia on the head.

The larvae are provided with a special kind of cilia, situated at the ends of every nototroch, which are used to take hold of the long provisional bristles in swimming. This suggests that one of the functions of the long bristles is that, in conjunction with these grasping-cilia, they increase the rigidity of the swimming larva, and hence the efficiency of its driving cilia.

Previous references to Polydora larvae are briefly discussed.
Notes on the Biology of Tellina tenuis da Costa
Authors: Stephen A. G.
Published: May 2009

The present paper deals with the results of investigations into certain phases in the life-history of the bivalve mollusc Tellina tenuis carried out during the autumn of 1926 and 1927.

Collections in the intertidal zone and below L.W.M., were made in a number of bays in the Cumbrae and neighbourhood, Kames Bay, Millport, being selected for intensive study.

In Kames Bay Tellina tenuis ranges from a little below H.W.M. to depths of about 4 fm. The maximum concentration of about 1000 per sq. m. is found at L.W.M. springs and the numbers decrease to zero at H.W.M. and 4 fm.

In Kames Bay the density of Tellina tenuis falls in a progressive manner from L.W.M. to H.W.M.

The size-frequency distribution shows a regular gradation from the lower to the higher levels. At L.W.M. and below individuals of small size predominate, while at H.W.M. they are proportionately few.

At higher levels growth is more rapid than at the lower levels.

The size-frequency curves and density of Tellina tenuis in the other bays at L.W.M. correspond with those of half-tide in Kames Bay.

The rate of growth may therefore be influenced by the density of population as well as by the habitat.

In all areas the 1926 brood predominates.

The Tellina tenuis population in Kames Bay seems to be composed of four year-groups, one of which is almost unrepresented. Collections from neighbouring bays indicate that older groups may be present.

The amount of young brood on the bottom seems to vary considerably from year to year, being large and small in alternate years.

The two closely related species, T. tenuis and T. fabula, are both plentiful in Kames Bay, but their range is not coincident.

Eipe sperms were found from May onwards and ova were rounding off in June.

Young Tellina tenuis, passing the 2-mm. sieve but retained by the 1-mm. sieve, were found in Kames Bay in August, chiefly below L.W.M., but in October plentifully distributed up to half-tide and in lesser numbers higher up the shore.

The food usually consists of vegetable detritus, but during the spring increase diatoms appear almost exclusively in the gut.
On the Food of Young Plaice (Pleuronectes platessa)
Authors: Scott Andrew
Published: May 2009

The investigation of the food contents in the stomachs of young fishes was included in the scheme of scientific investigations drawn up and initiated by Professor Herdman for the Lancashire Sea Fisheries Committee nearly thirty years ago. The lengthy series of Annual Reports contain here and there accounts of the observations made on the stomach contents of various Pleuronectidæ captured close inshore, and the pelagic stages of other fishes caught from time to time in the plankton tow-nets. No systematic attempt has, however, been made, in connection with the investigation of the Irish Sea, to determine the food of any particular species of fish during the early part of its life history.

Other observers working in other areas, notably Dr. Marie Lebour at Plymouth, have added very much to our knowledge of the early food of young fishes. Dr. Lebour's reports, published in the Journal of the Marine Biological Association, Vols. XI and XII, deal with a very large number of larval and post-larval stages of the more important food fishes caught in the tow-nets and young fish-trawl in Plymouth Sound and beyond.

The present report gives an account of the food contained in the stomachs of young plaice (Pleuronectes platessa, Linn.) from a few days after hatching to about five months old. The samples examined in April and May were taken from the spawning pond at Port Erin, Isle of Man, where they had hatched from the pelagic eggs spawned by the adult plaice early in 1921. The later stages examined during May to August represented young plaice hatched in the open sea about the same time as those in the pond, and which had made their way close inshore.
On the Young Stages ofBlennius ocellarisL.,Blennius pholisL., andBlennius gattorugineL
Authors: Ford E.
Published: May 2009

The post-larval blennies taken off Plymouth during recent years have been assigned to three species, namely,Blennius ocellarisL.,Bl. pholisL., andBl. gattorugineL. The process of identification, however, has emphasised the need for the revision of the available descriptions and illustrations of the various stages in development, and I have, therefore, thought it desirable to report on the Plymouth forms and give drawings of them.

Blennius Ocellaris (12 rays to the pectorals).

Ehrenbaum (2, p. 83) has copied two figures of the young of this species which were originally produced by Holt (5, p. 45), and it is somewhat unfortunate that both need to be commented upon. The first is satisfactory as a representation of the appearance of a larva some time after hatching, but the length is wrongly given as 6.3 mm. Garstang (4, p. 74) explained that this was an error in transcription, and, after a re-examination of Holt's specimens, he found that the total length was 4.6 mm. (varying between 4.55 and 4.65). The second figure, depicting a young fish of 18 mm., which Holt tentatively assigned toBl. ocellaris, was taken exception to by Garstang and the identification questioned, and it must be admitted that it does not portray satisfactorily the characters of the species.

The full account of the rearing of the young from the egg by Garstang (4) was unfortunately not illustrated; but as several of his original specimens are in the Plymouth collection, I have been able to identify quite readily the more recently captured examples and have made a series of drawings which are given below (Figs. 1 to 4).
On the Post-larvæ of the Wrasses occurring near Plymouth
Authors: Ford E.
Published: May 2009

Six species of Wrasses occur in the adult stage in the neighbourhood of Plymouth (Clark 3, p. 217), namely, Labrus bergylta Asc., Labrus mixtus (L.), Ctenolabrus rupestris (L.), Crenilabrus melops (L.), Centrolabrus exoletus L., and Julis julis (L.).
The Hydrogen Ion Concentration of Sea Water in its Biological Relations
Authors: Atkins W. R. G.
Published: May 2009

It has long been known that sea water is alkaline and numerous determinations of its alkalinity have been made. The method adopted was the usual one for mixtures of carbonates and bicarbonates, or some modification of it. Those waters which give no colour with phenolphthalein contain bicarbonate only, but for the most part ocean waters have a small amount of carbonate also. Owing to the presence of larger amounts of carbonates and bicarbonates the reaction of sea water is more stable than that of rain or river water, inasmuch as it has a greater alkaline reserve which acts as a “buffer.” The significance of this has been pointed out by Moore, Prideaux, and Herdman (1915) and by other workers. The measurement of alkalinity was carried out by the above named using N/100 hydrochloric acid and titrating to the end points with phenol phthalein and methyl orange. The results are recorded in cubic centimetres of centinormal acid per 100 c.c. of sea water; this is convenient as it is what is measured directly, but others adopt the perhaps more rational notation of milligram equivalents of hydroxyl per litre (Buch, 1914). One cubic centimetre of N/100 acid per 100 c.c. corresponds to 0.1 milligram equivalent per litre. Some workers on fresh waters, Birge and Juday (1911) for example, consider water as acid if it contains more carbon dioxide than that sufficient to convert the carbonate into bicarbonate, and titrate back to a pink with phenolphthalein. Their acid water is, however, still alkaline to methyl orange.
The Preparation of Permanently Non-acid Formalin for Preserving Calcareous Specimens
Authors: Atkins W. R. G.
Published: May 2009

Formalin, which is permanently non-acid and only slightly alkaline, close to pH9, may be prepared by the addition of borax till a good red colour is shown with phenolphthalein, or a slaty blue with thymol blue, when added to the diluted formalin.

Distillation of formalin from solid magnesium carbonate gives an acid product, which is at pH4·4.

Formalin neutralised with sodium hydroxide becomes acid on standing, the change being more rapid in sunlight than in the dark. A reaction of pH5·2 was reached in fifty-six days in light, the initial value being pH8·0. Commercial formalin, “ 40 per cent,” may be as acid as pH2·8.
A Contribution towards the Life History of Parorchis acanthus Nicoll, A Trematode in the Herring Gull
Authors: Lebour Marie V. , Elmhirst Richard
Published: May 2009

Parorchis acanthus is a Trematode described by Nicoll (1907) from the bursa Fabricii and rectum of the Herring Gull, Larus argentatus; in 1906 he first described it as Zeugorchis acanthus. Originally found at St. Andrews, it is now known to be common at Millport and also occurs in gulls from the Northumberland coast, and probably is abundant elsewhere. Nicoll found it once in the Common Gull, Larus canus. In 1907 (Lebour, 1907) one of the present writers described a cercaria occurring in rediæ from Purpura lapillus. This was named Cercaria purpurœ sp. inq., and afterwards identified with young stages of Parorchis acanthus in the Herring Gull (Lebour, 1914). It was thus shown that the first host of this Trematode is Purpura lapillus and the final host the Herring Gull, but the intermediate host was unknown. Localities for the cercaria were Loch Ryan, Wigtownshire; Budle Bay, Fenham Flats and Cullercoats in Northumberland; Robin Hood's Bay in Yorkshire; and Millport. Adults occur at St. Andrews, Northumberland coast and Millport, as already stated.

The Cercaria appeared to be closely related to Echinostomum cercariæ, and it was suggested (Lebour, 1914) that the intermediate host would probably be some marine bivalve, as it is often so with Echinostomum (e.g. E. secundum in Mytilus edulis and Cardium edule, E. leptosomum in Scrobicularia tenuis). This suggestion now proves to be correct, and we are able to show that the intermediate host of Parorchis acanthus is Mytilus edulis or Cardium edule.

On August 13th, 1921, at the Millport Station some larval cercariæ were noticed by Elmhirst swimming in a small glass aquarium, which contained a collection of Purpura lapillus, Cardium edule and Mytilus edulis.
Note on the Occurrence of Echinus esculentus above Low-tide Mark on the Cornish Coast
Authors: Trewavas Ethelwynn
Published: May 2009

When collecting on the shores in the Plymouth area, while a member of the Easter Class at the Marine Biological Laboratory, Plymouth, in 1921, I was struck by the absence above low-water mark of Echinus esculentus, as contrasted with its abundance in this zone at Port Erin in the Isle of Man; for there, as Chadwick states, “it may be collected by hand on the beach, and on the ruined breakwater at low-water of spring tides.” There is no record of this species except below tide-marks in the “Plymouth Marine Invertebrate Fauna” list (Journ. Marine Biological Association, Vol. VII, 1904).

In 1849 W. P. Cocks, in the Trans. Penzance Natural History and Antiquarian Society (“List of Echinodermata procured in Falmouth and Neighbourhood from 1843 to 1849”), recorded the occurrence of this species thus:—

“Echinus sphœra.—Trawl refuse; common: young specimen found attached to stones, low-water mark.”

Later (1887–8), in the same journal, G. F. Tregelles, in a paper on “Echinodermata of Mount's Bay,” makes the following statement of the species of the genus Echinus: “The commonest and largest is E. esculentus (Pennant) [E. sphœra Forbes], which literally swarms off this coast at all depths. It is brought in by trawlers; it is found in crab-pots, into which it climbs laboriously after bait; the seaweed gatherers obtain them in from one to two fathoms of water. The Mouse-hole fishermen call them ‘zarts,’ doubtless an old Cornish word.”
The Laboratory of the Marine Biological Association at Plymouth
Authors: Allen E. J. , Harvey H. W.
Published: May 2009

The Marine Biological Association of the United Kingdom, to whom the Plymouth Laboratory belongs, is a corporate body of subscribing members, interested in scientific investigations concerning the habits and life-histories of food fishes and other marine animals. The Laboratory is managed by a Council elected annually by the members of the Association.