A clear preference for the actinian anemones Actinia equina, Anemonia sulcata and Anthopleura elegantissima was demonstrated, while the acontian anemones and Corynactis viridis ranked low in the order of preference. The significance of acontia as defensive structures in anemones is discussed briefly. No differences in food preference were found between eolids collected from Plymouth and Millport; and British Aeolidia behaved in the same way towards Californian anemones as did Californian Aeolidia.

The eolids varied in their tendency to bite different species of anemone, but the performance of each individual eolid was similar in different experiments. It is possible that the individual variations may account for conflicting reports in the literature.

For a long time, eggs of the garpike Belone belone have been the subject of intensive and thorough studies on the early embryology of teleosts (Ryder, 1882; Sobotta, 1896; Ziegenhagen, 1896; Kopsch, 1901; Borcea, 1909). This can be attributed to the fact that the eggs of Belone are fairly large in size (3.0 to 3.5 mm diameter, Ehrenbaum, 1905), and easy to collect from submerged plants. Ryder (1882) already used artificially fertilized eggs of Belone for his study on the circulatory system of teleosts.

This paper reports the first phase of an extended exercise in benthic ecology, involving both long- and short-term aims. The short-term aim is to examine the benthic fauna of representative substrate types for a period of a year and to compute the net secondary production of the infaunal macrofauna in terms of ash-free dry weight per square metre per annum. The intention is to identify from among the bulk of species those animals which have the highest productive capacity, to rank these in order of productive importance, and finally to give our best estimate of the production of the animal assemblage as a whole.

The exceptionally heavy settlement of larvae in the autumn of 1970 made it imperative to continue the observations of the previous ten years. This two-year extension has yielded much new knowledge about the growth of Sabellaria colonies at Duckpool, and about other aspects of their life. It revealed that the more densely packed the young were the faster their colony grew, provided conditions were favourable. In unfavourable circumstances close packing of young delayed growth. The rapid elongation of young tubes surrounding older tubes sometimes resulted in holes and fissures forming when the older worms failed to maintain all-round contact with surrounding young as the surface area of a colony increased. Such holes and fissures gave a false appearance of physical damage, and in colonies where they formed weakened the whole structure, becoming a factor in its ultimate destruction by wave action. Such fast-growing colonies have shorter lives than others growing more slowly and remaining more compact.

Two new deep-sea barnacles (Cirripedia) are described. The first, from approximately 5200 m in the Southwest Atlantic, belongs to the most generalized genus of the order Ascothoracica, Synagoga. The two previously known species, S. mira from the Mediterranean and S. metacrinicola from Japan, are from relatively shallow water. The new species is not only more generalized than either of these, but it exceeds previous depth records for any ascothoracican by more than 1000 m. It is apparently a sequentially protandric hermaphroditic ectoparasite, knowledge of which helps clarify difficulties in interpreting the life histories of certain more highly evolved endoparasitic forms. On the other hand, its markedly generalized features bear heavily on considerations of the origin of the Maxillopoda.

The second new species, from approximately 1500 m in the Bay of Biscay, belongs to the most generalized genus of the order Acrothoracica, Weltneria. It is closely related to W. hessleri known from 1000 m off Bermuda and the two are unique in being the only true deep water members of the order. The new species is remarkable in inhabiting a friable, clayey substrate - all other acrothoracicins are known to burrow only in relatively solid forms of calcium carbonate. However, both have a calcified rostral plate, and this indicates that the Acrothoracica stem from scalpellid rather than cyprilepadid or iblid Lepadomorpha.

Surveys of marine benthic distributions are usually performed by sampling from a vessel capable of handling the heavy sampling devices necessary. Because of the inability of such vessels to work in very shallow water or close to the shore the area just beyond the intertidal zone is inaccessible to investigation except by a special vessel (e.g. Mclntyre & Eleftheriou, 1968) or by using diving techniques (e.g. Hughes & Thomas, 1971). This has created a gap in our knowledge of this area, which may be of some importance in reflecting adaptation to effects of land on sea which are not complicated by the effects of tidal exposure.

Euryhaline fishes, such as the salmon and the eel, adapt the osmoregulatory mechanisms of their gills, kidney and intestine so that they retain water while they are in the sea but retain salt while in fresh water (e.g. Krogh, 1939). Thus on entering fresh water the osmotic pressure of plasma in the Atlantic salmon, Salmo salar L., only falls from some 410 m-osmole/1 to about 340 m-osmole/1 (calculated from the freezing point data of Benditt, Morrison & Irving, 1941), although the osmotic pressure of the environment falls from around 1000 m-osmole/1 to almost zero.

A small collection of cephalopod remains taken from 26 blue shark stomachs is examined. This includes 92 lower and 97 upper beaks which are identified as far as possible to species. From measurements of the beaks, mean weight and total weight of each cephalopod species is estimated. The presence of oceanic cephalopod remnants in the stomach contents indicates that some sharks caught in the Looe area had recently migrated inshore from deep water.

A small collection of cephalopod beaks from the stomach of a sperm whale caught off Vigo is described, identified and the weight of cephalopods represented is estimated. Comparisons are made with a similar collection previously described from a whale caught off Madeira.

Measurements have been made, by neutron activation analysis, of arsenic, cadmium, antimony, mercury and zinc in organisms and bottom muds, mainly from Southampton Water and the Solent. The values are on a dry weight basis and refer to whole organism soft tissues unless otherwise stated.

Concentrations of mercury in algae ranged from 0·07 to 0·22 ppm and those in animal tissues from 0·06 to 1·9 ppm. The distribution of the element in various tissues of Mercenaria mercenaria was rather uniform, except that the concentration in the gills was about 2·5 times that in the whole organism. Variations amongst organisms from different parts of the Solent area and comparisons with other regions suggested some possible influences of local waste discharge, but there was no evidence of major effects. Anoxic muds contained higher concentrations of mercury than occurred in unreduced surface layers, suggesting mobility in interstitial waters of the uppermost zone and fixation under reducing conditions.

Diversity is one of the most important parameters used in the description of a community; several theories relating diversity to other phenomena as predation, competition and stability have been proposed (Pianka, 1966). As a result of the increasing interest in diversity a number of studies have appeared during recent years, but the meiofauna has until recently been almost completely neglected, rather surprisingly when one considers the importance of this group of organisms in all marine benthic communities. Coull (1972) studied recently the diversity of harpacticoid copepods, with nematodes the major meiobenthic component, along the North Carolina shelf and in the deep sea. Warwick & Buchanan (1970) appear to be the only ones to have studied diversity in nematode communities, using α of the logarithmic series (Fisher, Corbett & Williams, 1943) as a diversity measure. The paucity of data seems primarily to be due to the taxonomic difficulties encountered in studying nematodes.

The inshore fishery for the pilchard in Cornish waters has existed for several hundred years, and such records as are available concerning fluctuation in catches and market conditions have been reviewed by Couch (1865), Cushing (1957) and Culley (1971). Although pilchard have been landed from Lyme Bay, from the eastern half of the Channel, and from the southern North Sea (Couch, 1865; Furnestin, 1945; Cushing, 1957; personal communications G. T. Boalch) the catches have usually been incidental to other fisheries and more sporadic than in Cornish waters. Traditionally there are three areas fished for the Cornish pilchard: on the north-west coast around St Ives; in Mounts Bay and towards the Scillies; and between the Lizard Pt and Bolt Tail in Devon (Couch, 1865; Culley, 1971). The latter region, constituting the inshore waters of south-east Cornwall and south Devon, effectively forms the eastern limits of the regular occurrence of commercial shoals. Knowledge of the breeding and life-history of the fish in this region has always been scarce and subject to much hearsay evidence (reviewed in Southward, 1963). Up to quite recently it was thought that the main spawning area lay well to the west of the entrance to the Channel, and it was not until the investigations reported by Corbin (1947,195°) a nd Cushing (1957)tnat it was conclusively shown that extensive spawning can occur within the English Channel from May to October. The relationship of the spawning in the western Channel to the other areas of spawning off the entrance to the Channel and in the northern Bay of Biscay is illustrated in a recent series of reports (Arbault & Boutin, 1968; Arbault & Lacroix-Boutin, 1969; Arbault & Lacroix, 1971; Wallace, P. D. & Pleasants, C. A., duplicated ICES meeting paper CM 1972/J: 8), and is further demonstrated by Demir & Southward (1974) in discussing the results of a study of small scale seasonal changes in spawning intensity in inshore waters.

The marine Amoebida have not been investigated nearly as extensively as freshwater and soil species of that order. In North America, where they have received the most attention, they have been studied most by Schaeffer (1926), with more recent work by Bovee (e.g. 1956), Sawyer (1968, 1971a, 1911b, 1974a, 1974b, papers in preparation), and Page (1970, 1971a, 1971b, 1972a). Grell (1961, 1966) and Grell and Benwitz (1970, 1971a, 1971b) have investigated some interesting amoebae from European and African marine habitats. Droop (1962) described a new species of amoebo-flagellate (Amoebida, Vahlkampfiidae) from brackish water in Scotland, but otherwise there is little literature on British marine Amoebida. Some recent work on the British fauna was reported by Page (1972b, 1973, 1974).

A total of 618 cephalopods comprising 29 identified species and 98 young unidentified larvae were collected at 30° N 23° W in opening–closing rectangular midwater trawls (RMT combination net), an Isaacs Kidd midwater trawl equipped with an openingclosing bucket and a British Columbia midwater trawl. Discrete horizons were fished between the surface and 2000 m and day and night vertical distribution for the more common species is described. Material is sufficiently abundant to draw tentative conclusions on the vertical distributions of 16 species. These show a wide variety of migratory and non-migratory behaviour including diel migration, ontogenetic migration and static distribution at various depths and over various depth ranges.

A high concentration of certain planktonic animals was found in a frontal region in the English Channel. Temperature, salinity and current measurements and direct visual observations (underwater) describe the nature of the front. It is shown that water depth, season, strong tidal mixing and residence time are important factors leading to the formation and maintenance of a turbulent convergent tidal front.

The distinguishing features of the common squid of British waters, Loligo forbesi, are summarized, and contrasted with those of L. vulgaris. The life-cycle and growth of L. forbesi are described, based on samples from trawl catches off Plymouth. This species seems to be an annual - young squid first appear in the trawl in late May, when their length is about 10 or 11 cm. Subsequent growth is rapid, and the males reach 30 cm and the females 25 cm by November. Spawning takes place mainly in December-January, but may continue into the spring. Neither sex survives beyond a single spawning season. Hatching of the spawn probably takes 30–40 days, and if the young squid taken in the trawl in late May hatched in the early part of the same year, a growth rate of about 25 mm/month would be required. Known growth rates for other species of Loligo are about 20 mm/month, so that indicated for L. forbesi does not seem to be impossibly high. The life-cycle is summarized in Fig. 8. There is also a summer spawning population, which grows to a rather smaller size at maturity, and which also seems to be annual.

During the summer L. forbesi ranges throughout the English Channel and southern North Sea, particularly in inshore areas. In October the squid migrate farther offshore and tend to occupy the western part of the Channel.

Values for total weight of squid/2 h trawl are given, on a monthly basis, for 1966–9. The largest quantities are usually taken in October and November, the highest single figure being 30.54 kg/2 h trawl, in November 1967.

Two new species of cranchiid cephalopod are described. These were both collected by opening-closing midwater trawls (RMTs) when vertical series were fished in the North Atlantic from R.R.S. ‘Discovery’.

The spatial settlement of marine invertebrate larvae is not a random process. The distribution of the adults of a particular species is influenced by the behavioural responses of the animal to a range of environmental stimuli which, in the case of many sessile invertebrates, result in the display of clear substrate selection. The role of habitat selection in determining the distribution of aquatic invertebrates has been the subject of a review by Meadows & Campbell (1972). The selection of algal substrata by the larvae of various intertidal species of Bryozoa has been demonstrated by Ryland (1959); among these, the ctenostomatous bryozoans Alcyonidium hirsutum and A. polyoum were shown to exhibit a strong preference for fronds of the alga Fucus serratus, an experi-mental result which accorded well with the distribution of the two species on the shore (Ryland, 1962).