bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Ascidians Trididemnum Alleni and Distaplia Garstangi, New Species from the Plymouth Area
Authors: Berrill N. J. 
Published: May 2009

Two ascidians have been collected in the region of Plymouth that do not fit the descriptions of known species sufficiently well to be identified with them. They are species of Trididemnum and Distaplia.These genera are represented in waters around the British Isles only by Trididemnum tenerum (Verrill) and Distaplia rosea Delia Valle. If Trididemnum niveum should be a valid species and not a synonym for T. tenerum as considered by Hartmeyer (1924), it also is probably present. Accordingly, any species that cannot be identified with these forms must either be new, or must represent geographical extensions of species not previously recorded. In this last respect, the possibility of the Mediterranean Distaplia magnilarva reaching the western Channel must be considered. As the following discussions indicate, the conclusions are that the two forms described here cannot be properly identified with any of the above and are to be treated as new species.Trididemnum alleni n.sp. is named after the late Dr E. J. Allen, so long the inspiring and humane director of the Plymouth Laboratory, while Distaplia garstangi n.sp. is so named as a small tribute to Professor Walter Garstang for his pioneering interest in the ascidians of Plymouth waters.Trididemnum Alleni sp.nov.Colonies are usually small, less than a centimetre in greatest length, and about 3 mm. thick. They are brilliantly white, an appearance retained even in preserved specimens of long standing. The surface is uneven. They are commonly attached to Eunicella and larger hydroids such as Antennularia at depths of from 10 to 30 m., and have been recorded with certainty only from the Plymouth area of the English Channel.
The Development and Growth ofCiona
Authors: Berrill N. J. 
Published: May 2009

Ciona intestinalis(L.) is probably the most cosmopolitan species of ascidians and has long been of general interest. The adult morphology has been well described in monographic form by Roule (1884), the physiology of the heart and circulation by Heine (1902), Enriques (1904) and Wolf (1932), of the nervous system by Magnus (1902), Hecht (1918, 1926), Cate (1928), Haffner (1933), and Bacq & Florkin (1935), and of the digestive system by Yonge (1925). Developmental studies include that of the early embryology by Conklin (1905), problems of fertilization by Morgan (1945) and Damas (1899,1900). In no work, however, has there been a presentation of the entireCionaorganism from the tadpole stage through the critical post-larval stages to the young cionid ascidian. The present account portrays this period of development, together with a discussion of some significant but relatively obscure aspects of adult structure.Eggs and theRearing ofCiona intestinalisWhile ascidians in general are difficult to rear to maturity under laboratory conditions,Cionais relatively easy, and together withBotryllus schlosseri(Pallas) andDiplosoma gelatinosum(M.-Edw.) is liable to appear more or less spontaneously in large aquaria into which tadpoles may have been brought. Artificial fertilization is readily accomplished, and at almost any time of the year, sinceCionais sexually mature above a certain size and reproduction is seasonal only to the extent of the rhythm of the growth cycle. Normally eggs are set free spontaneously at dawn, although individuals kept in the laboratory may accumulate eggs and the oviduct become swollen.
Observations on the Biology and Post-Embryonic Development of Idotea Viridis (Slabber) (Isopoda, Valvifera) from New England Creek, South-East Essex
Authors: Howes N. H. 
Published: May 2009

A local race of Idotea viridis from south-east Essex is described and its classification as /. viridis discussed. This animal is a nektonic form and so far has only been found in New England Creek in south-east Essex. The biology and post-embryonic development of this race is described. Quantitative samples were taken of the animals present in the creek in 1934, 1935 and 1936. I. viridis was rare in the first five months of the year; numbers rose to a maximum in late June and July and remained comparatively high until the end of October.The number of young in the brood pouch is very variable. There is some evidence that the number of fertilized eggs was reduced by the expulsion of embryos before their development was complete. The newly hatched I viridisis described.
Some New Sand-Dwelling Copepods
Authors: Nicholls A. G. 
Published: May 2009

The copepods described in this paper come from two sources, the Firth of Clyde and the St Lawrence River. Several new species were collected from Balloch Bay on the Greater Cumbrae in 1935 and 1936 during an attempt to obtain some of the early species described from Scottish waters. The remainder were collected while working at the Biological Station at Trois Pistoles, Quebec, during a visit to Canada in 1937. The environment in Balloch Bay is composed of a fine muddy sand, strewn with boulders. The bay is on the eastern side of the island and therefore in a sheltered position. A description is given in Appendix III of The Biology of the Sea Shore, by Flattely & Walton (1922). The conditions under which the Canadian material was found will be dealt with in a later paper describing the remainder of the collection from the St Lawrence; it will be sufficient here to state that the conditions are essentially marine.Copepods from three allied genera are included here: Paramesochra T. Scott, 1892; Leptopsyllus T. Scott, 1894; and Remanea Klie, 1929. The first two have for some time been in a state of considerable confusion and it has been a matter of some doubt into which genus the various species should be placed. Several efforts have been made to clarify the position (notably by Klie, 1929 and Monard, 1935) but the more recent work of Kunz (1938) has produced a clear separation based on the presence or absence of an endopod on the second leg.
Seasonal Variations in the Fat Content of the Flounder, Pleuronectes flesus L
Authors: Wilson Douglas P. 
Published: May 2009

In the flounder adipose tissue forms a padding between the muscles to the dorsal and ventral fins. A little is present under the skin, more especially where the lateral line septa and the myocommata meet the skin. In addition a quantity of fat is associated with the skeleton.Immature flounders living in the estuaries of the Tamar and Lynher are fattest after intense feeding during the summer, and leanest after the winter fast.Maturing flounders have a high fat content before going to sea to spawn. While in the sea during the spawning season, February to April, very little feeding takes place and there is a rapid drop in fat content. Spent fish are very lean.Those females which return to the estuaries after spawning rapidly make good their fat loss.
Substances Controlling the Growth of a Diatom
Authors: Harvey H. W. 
Published: May 2009

The diatom Ditylum brightwelli requires, for vigorous growth in artificial sea water, two organic substances, or groups of substances, in addition to inorganic salts. The substances, or groups, act in a manner complementary to each other.The effect of adding either is greatly increased by the presence of the other.One accessory substance, or group, has been obtained in impure state from natural sea water and from extracts of algae by adsorption on carbon and elution. It has properties of an inorganic acid or internal anhydride.
Studies in the Market Sponges I. Growth from the Planted Cutting
Authors: Crawshay L. R. 
Published: May 2009

An account of the chief earlier experiments, from those of Cavolini in 1785 to the close of Moores experiments in Florida in 1905, is given and the general subject of reconstruction and growth in the sponge cutting is described in detail.Under favourable conditions loss of volume in the initial stages, following cutting, should be practically negligible, the early steps in repair and reconstruction proceeding without delay after severance of the fragment from the original sponge. As chief among these, the dermal covering required for newly cut surfaces, the closing of most of the exposed apertures of the old canal system, and the retention of one or more of these for future oscula, are accomplished rapidly and, for preliminary purposes, are completed within a very few days
The Intertidal Ecology of Selected Localities in the Plymouth Neighbourhood
Authors: Evans Ronald G. 
Published: May 2009

The work includes an investigation of the intertidal distribution of several species previously studied in Cardigan Bay. Twelve localities in the neighbourhood of Plymouth were selected for study, showing a range from conditions of extreme exposure to surf action to conditions of maximum shelter. The main features of rock configuration and surf action at the different localities are briefly described.The method of investigation is described, and results obtained for the zonation of the fucoids on Church Reef are compared with the results of Colman (1933). It concluded that the method of survey adopted in the present work yields results of a high degree of accuracy.The horizontal and vertical distributions of the flora are described and related to the intensity of surf action. This is followed by a discussion of the effects of wave intensity and wave frequency on the distribution of algae in general. The importance of the frequency of wave shock in the mid-tidal region of the shore, and its influence on algal colonization, is stressed. An attempt is made to arrange the algae studied in order of decreasing tolerance of surf.The distribution of the selected species of animals at the different localities is described; and a discussion follows on the effect of wave action as a presence or absence factor in horizontal distribution, and as a modifying factor on vertical zonation. The effect of surf on the size of individuals of certain species is also commented upon.The relation of the plant and animal species to different percentage exposures to the air at different shore levels is discussed.
The Effect of Trematode Parasites on the Growth of Littorina Neritoides (L.)
Authors: Rothschild Miriam 
Published: May 2009

If the number of infections with (a) trematode parthenitae and cercariae using Littorina neritoides as first intermediate host only, and (b) encysted metacercariae using L. neritoides as second intermediate host only, are plotted against the size of the snails, two different curves result. The first shows a low rate of infection in the small size groups, but a steep upward slope rising to 91% in the large size groups. The second shows a curve increasing uniformly to 87% infection.Possible interpretations are discussed, and it is concluded that the difference is probably due to the fact that primary infections cause accelerated growth in the host.
A Note on the Determination of Very Small Quantities of Hydroxylamine by Blom's Method
Authors: Barnes H. 
Published: May 2009

In a study on the possible occurrence of hydroxylamine as an intermediate compound in the oxidation of ammonium salts to nitrites in sea water (see Cooper, 1937), the method of Blom was tried in order to estimate the hydroxylamine. The method consists in the oxidation of the hydroxylamine by a solution of iodine in acetic acid, removal of the excess of iodine with N/Io thiosulphate, and estimation of the nitrite so produced by the Griess method; the method has been used by several workers for the estimation of small amounts of hydroxylamine in biological material.The method had not been used for such small amounts of hydroxylamineas would be expected in sea water, and it was therefore tested at high dilutions. It was found that nitrite itself, however, could not be recovered after treatment with the above reagents, and it was noticed that in many cases a precipitate (probably sulphur) was produced, and a distinct smell of hydrogen sulphide was often apparent. It was thought probable therefore that the loss was due to the interaction of the nitrite or the red dye with the thiosulphate used for removing the excess of iodine. This view was confirmed by noting the removal of the red colour, the appearance of a precipitate, and the smell of hydrogen sulphide when a solution of thiosulphate was added to a solution of the dye.Experiments were therefore set up to determine the amount of thiosulphate that could be present in excess without interfering with the estimation.
Oyster Rearing on the River Yealm
Authors: Wilson Douglas P. 
Published: May 2009

In a recent issue of this Journal Dr Hughes (1940) published records of a successful attempt to rear oysters in tanks on the River Yealm during the summer of 1939. In this paper he referred to plans for the following year, and it therefore seems desirable to record a few notes on the 1940 season.Since Dr Hughes left Plymouth I have kept in touch with Mr J. Kingcome, the owner of the fishery, and from time to time have visited his tanks and proffered technical advice. In this I have had the willing co-operation of Mr H. A. Cole of Conway whenever his opinion has been sought. Mr King come has most readily adopted suggestions we have made, and it is to his careful attention and unremitting work that the successful results here recorded are due.Further History of the 1939 SpatDr Hughes mentioned that in August 1939 some of the larger spat were detached from the tiles and placed in cages in the estuary of the river. At the time of writing (mid-October 1940) these range from 4.5 to 8 cm. in diameter. The remainder of the spat spent the winter on the tiles in tank C (Hughes, 1940, Fig. 1), being given almost daily changes of water from the estuary. They were detached from April to July 1940 and placed like the others in wire-meshed cages just above low-water mark spring tides. These oysters have by no means reached the size of those which have been out since August 1939, the size range being 2–4 cm. in diameter.
On the Hydrorhiza and Claspers of the Hydroid Myriothela Cocksi (Vigurs)
Authors: Manton S. M. , Harding J. P. 
Published: May 2009

The hydrorhiza of Myriothela cocksi is described. It bears adhesive tentacles covered by perisarc, which adhere to the substratum by their flattened extremities.The chitin forming a disk of adhesion is thick, and is attached to the mesogloea of the tentacle. The terminal ectoderm persists.The hydrorhiza of M. cocksi and of species such as M. capensis, M. penola, and M. phrygia, etc., is built on a common plan. In the latter species the perisarc is reduced to adhesive disks more firmly attached to the mesogloea.The method of growth of M. cocksi is recorded.The structure and method of attachment of the claspers of M. cocksi to the egg membrane is described. The mesogloea at the tip of the clasper fuses with the egg membrane after the disappearance of the terminal ectoderm.Evidence is given for the view that the claspers of M. cocksi represent a specialized part of the hydrorhiza.
The Genital Ducts of Some British Stenoglossan Prosobranchs
Authors: Fretter Vera 
Published: May 2009

The foregoing pages include an account of the anatomy and histology of the male and female genital ducts of Ocenebra erinacea, Nucella lapillus, Nassarius reticulatus and Buccinum undatum. Observations have also been made on the mode of functioning of the ducts and the formation of the egg capsules.In both male and female it is possible to divide the genital ducts into a narrow and thin-walled proximal section which leads from the gonad and opens into a thick-walled glandular distal region, and in this respect the Stenoglossa agree with the mesogastropods. Near the junction of these two portions, in the female, arises the gonopericardial duct, which puts the genital duct into communication with the pericardial cavity; in males this structure i s lost or reduced to a vestige lying in a similar position.In males the upper part of the proximal region of the genital duct is used as a vesicula seminalis and the epithelium is capable of taking up and digesting effete or superfluous sperm. Sperms are passed from it into the anterior, distal region during the act of copulation, and secretion from the glands is mixed with them and provides the medium in which they are transferred to the female. In Ocenebra and Nucella this glandular region, the prostate, extends only as far as the opening of the mantle cavity, from which a continuation of the duct, without glandular walls, runs to the penis. The entire distal half of the male duct shows evidence of having been derived from an open seminal groove such as is found in Littorina.
Plankton Production Between the Yorkshire Coast and the Dogger Bank, 1933–1939
Authors: Wimpenny R. S. 
Published: May 2009

Between March 1933 and June 19391 a series of vertical hauls with a plankton net has been made at a line of six stations 12 miles apart, the first lying off Flamborough Head and the last on the south-west patch of the Dogger Bank. This line was usually visited at monthly intervals, the net used being of the Hensen type fitted with bolting silk of 60 meshes to the inch and hauled to the surface by the counter-weight device introduced by Buchanan-Wollaston (1911). Hensen (1887) worked out a filtration coefficient for his net, and when this was applied to the dimensions of the one in use and the depth through which the vertical hauls were made, it was possible to express the catch in numbers per cubic metre of sea water. It was also possible to give the individual catches by weight, and it may not be without interest to observe, before passing on to deal with numbers, that the dry weights taken in 1936 varied between 0.2600 g. per m.3 in August and 0.0015 in February.Although the net method of estimating plankton has often been decried as unreliable, Hensen net results have always given a consistent picture of relative plankton densities in the North Sea. Confidence arising from this consistency has not been lessened by a comparison of the net and sedimentation methods which has been made in respect of the May 1938 samples.The sedimentation method consists in counting the entire deposit of microplankton which has settled on the floor of a glass cell containing a known volume of sea water.
Size Variations in the Cyprids of Some Common Barnacles
Authors: Barnes H. 
Published: May 2009

The sizes, length and breadth, of the cyprids of Balanus balanoides, B. crenatus and Verruca stroemia have been measured on material collected. during the spring outburst and in the later part of the year.The size-frequency curves for Balanus balanoides and B. crenatus show at least two distinct modesduring the spring, equivalent to populations of two distinct sizes. It is suggested that these correspond to populations developed in different environments. Measurements of the nauplii taken from adults at different points on the shore indicate that the size of the nauplii is dependent to some extent upon the conditions of development, the conditions also affecting growth and total nauplii output.Swedish samples, in which the parents had developed under more uniform conditions, showed only a single population as regards size.In B. crenatus and Verruca stroemia, which produce further broods during the year, the size decreases in these later broods. The rate of development of the eggs and embryos, probably dependent upon temperature, is suggested as the important factor.
Decreased Discrimination During Setting After Prolonged Planktonic Life in Larvae of Spjrorbis Borealis (Serpulidae)
Authors: Knight-Jones E. W. 
Published: May 2009

Laboratory experiments showed that freshly liberated Spirorbis larvae settle on surfaces which bear previously settled individuals, in marked preference to bare controls, but that larvae which have been kept swimming for 3 hr., or longer, exercise less choice when setting.When larvae are freshly liberated there is a great difference between the rate of setting gregariously, and the rate of setting in isolation; but after they have been kept swimming for 3 hr. this difference becomes less, owing to the larvae setting more rapidly both gregariously and in isolation. After swimming for about 8 hr. rates of setting fall off, and many larvae fail to settle, apparently through weakness.I am greatly indebted to Dr D. J. Crisp for advice regarding this problem, and to him and Mr G. M. Spooner for much help with statistical treatment.
Studies on the Interrelationships of Zooplankton and Phytoplankton
Authors: Bainbridge Richard 
Published: May 2009

An apparatus in which it is possible to observe the horizontal migrations of zooplankton in gradients of phytoplankton is described, and an account given of its use in experiments involving various organisms. A preliminary search for toxic organisms is also described.The experiments comprise a demonstration of a migration by various animals into concentrations ofthe diatoms Skeletonema, Thalassiosira, Biddulphia, Nitzschia and various mixed cultures and the flagellates Chlamydomonas, Peridinium, Dicrateria, K, and Oxyrrhis. Cultures of Rhodomonas and Gymnodinium II are found to produce the opposite effect, and no reaction towards Lauderia, Coscinodiscus, Eucampia, Syracosphaera and Exuviaella could be shown. Results with bacteria cultures andvarious inorganic gradients are also discussed.A second apparatus in which it is possible to observe the vertical migrations of zooplankton in the presence and absence of phytoplankton is also described, and an account given of experiments in it involving various organisms.The experiments comprise a demonstration that greater numbers of animals swim up in the presence of mixed phytoplankton cultures, Coscinodiscus, Skeletonema, Ditylum, Chlamydomonas, Gymnodinium I and II and Oxyrrhis than in unenriched water. Flagellate One has no effect and Chlorella possibly depresses the number swimming up.Under-water observations on the swimming movements of some of the animals used are described.
The possible application of the observations towards resolving the problem of the inverse distribution of phytoplankton and zooplankton in the sea is discussed, and the hypothesis is proposed that this may be accounted for by a combination of migration and grazing. It is considered that plankton animals must migrate both horizontally and vertically into patches of phytoplankton and, when present in sufficient numbers, graze these down very quickly.
A Preliminary Check-List of British Marine Algae
Authors: Parke Mary 
Published: May 2009

This preliminary list of some of the classes of the algae has been prepared, mainly for the use of British phycologists, to form a basis on which to work for the eventual compilation of a complete check and locality list of all species of British marine algae. The compiler would be grateful for all additions and corrections to this list, and for records of marine species from the algal classes not included in the present list.The classes of algae treated in this list are the Chlorophyceae (53 gen., 156 spp.), Xanthophyceae (7 gen., 15 spp.), Chrysophyceae (15 gen., 22 spp.), Phaeophyceae (96 gen., 199 spp.), Rhodophyceae (126 gen., 324 spp.), and Cyanophyceae (39 gen., 125 spp.). The genera are listed alphabetically under the family and the species alphabetically under the genus. If a name has been changed from that given in Newton (1931), the name in Newton is added, in brackets, below. Names preceded by a question mark appear to need revision for nomenclatural or taxonomic reasons. Most of the so-called varieties listed are very probably merely habitat forms of the species, but further investigation is needed before new combinations are made for them. Notes are given at the end of each class, the number in brackets following a name in the list refers to these notes.The compiler is grateful to Mr R. Ross and Miss Linda Newton, of the British Museum, and to Miss C. I. Dickinson, of the Herbarium, Kew, for their help over a number of problems.