The life-cycle of a population of Pandalina brevirostris living off the Northumberland coast is described. Most specimens were taken over sandy gravel or sandy mud with a covering of zoophytes in depths ranging from 20 to 30 fm. A very few specimens were taken over soft mud in 50 fm.

Eggs are laid during the period from January to the beginning of September. Females may lay two or possibly three broods in each breeding season. There is a period of 12–14 weeks between the laying of the eggs and the hatching of the larvae. The ova of those females that have a brood of eggs within the first half of the breeding season mature as the eggs develop, and are ready for laying following the release of the larvae. The adult P. brevirostris reaches maturity 8–12 months after hatching as a larva and lives on to breed again in the following season. They die at the end of their second breeding season. Thus, the probable life-span of the female is 24–30 months following its release as a larva, while that of the males is about 21–27 months.

Just before spawning the semen of the herring is isosmotic with the parent blood, the eggs are hyposmotic. Immediately the eggs are placed in sea water of salinities 5, 17·5, 35 and 50 %0 there is a change in the freezing-point of the yolk indicating that it has approached close to being isosmotic with the water. Changes in the freezing-point of the yolk during development indicate that the overgrowing embryo gradually regulates the osmotic concentration of the yolk, although full regulation is not achieved until after the closing of the blastopore. After this point there is no significant change in the freezing-point of the yolk or body fluids. Regulation is most probably brought about by the activity of the cells of the ectoderm.

An apparatus for sampling the fauna of the uppermost 10 cm of the sea is described. The net is designed to fish at speeds of 5–6 knots in undisturbed water to one side of a ship. A preliminary account is given of the catches made with the net in the Indian Ocean.

The biochemical composition–water, glucose, soluble and insoluble glycogen, protein and non-protein nitrogen, total lipid–of the eggs of Balanus balanoides and B. balanus has been determined during development.

Preliminary analyses of the pigment content are reported.

The changes in both species are similar; but they take place more rapidly in B. balanus with its shorter period of embryonic development.

During development there is a net loss of all fractions; small increases of glucose and soluble nitrogen are, however, found at certain stages.

The pigment is largely a chromolipid; during the early stages of development this increases, but is subsequently lost; astaxanthin is also present. The visual appearance is a poor guide to pigment content.

The oxygen uptake of the eggs has been measured.

There is a discrepancy between the oxygen uptake measured directly and that required to oxidize the substrate lost; the causes of this are discussed.

The results are discussed relative to the habitats of the species.

The heart-body contains haematins derived from by-products of haem synthesis. It also contains a non-haem iron protein and a flavin. Study of the relative amounts of these substances in worms of different ages and at different seasons suggests that the flavin plays some part in the metabolic activity of the organ and that the haematins accumulate throughout life. No evidence was found for the heart-body participating in any excretory activity or in haemoglobin breakdown.

Data from nearly 900 individual herring sampled in the North Shields, Whitby and East Anglian fisheries during the period 1956–60 demonstrate a linear relationship between the percentage fat and the percentage water contents for whole herring minus gonads and gut content, and the fat/water line derived from the data is described.

A long-established population of Jaera hopeana living ectocommensally upon Sphaeroma serratum is described from Wembury. This is a new record for the British fauna and is the northernmost record of a species which is found predominantly in the Mediterranean and Black Sea.

The feeding mechanisms of Ophiocomina nigra have been re-examined. A new mechanism, the mucus-net method, is described for the first time. This is essentially a method of suspension feeding in which seston is trapped in a net of mucous threads between the arm spines. The entangled material is formed into boluses by simultaneous activities of ciliary currents and the tube-feet and is transported to the mouth by the tube-feet.

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.

Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.

This research has been concerned with the movement of pigment in the occlusible tapetum lucidum of the spur dog Squalus acanthias. The pigment expands and covers the reflecting plates of the tapetum in light, and retreats and uncovers the plates in darkness. Movement of pigment in one eye occurs independently of that in the other. Normal movement of pigment is not affected by cutting the optic nerves and oculomotor nerves, by sectioning the cord immediately behind the medulla, nor by excising the pituitary and pineal glands. It is concluded that the process is not under nervous or hormonal control. It occurs normally in excised opened eyes that are kept in oxygenated Ringer solution, but not under partial or fully anoxic conditions. The pigment cells of the chorioid seem to be behaving as independent effectors, sensitive to light. The pigment expands in tapeta freed of retina, in light or darkness. No explanation is yet available for the latter anomalous result. Measurements were made of the reflectivity of isolated tapeta, and curves are presented showing the progressive decrease of reflectivity accompanying expansion of pigment, and changes in the colour composition of the reflected light.

Nitrogen excretion by Calanus finmarchicus (Gunnerus) and C. helgolandicus Claus collected at Millport and Plymouth has been measured under various experimental conditions.

Adult females feeding on Brachiomonas submarina, Cricosphaera elongata and Skeletonema costatum at cell concentrations corresponding to the mean annual level of particulate nitrogen in Plymouth Sound excrete 12·4, 9·0 and 6·4 μg N/mg dry body weight/day respectively. When the concentration of food is raised, as might occur during a spring outburst of phytoplankton, there is an increase in the quantity of nitrogen excreted. On the other hand, nitrogen excretion rapidly diminishes in the absence of food.

The hitherto unknown hydroid of the anthomedusa Neoturris pileata has been found abundantly in the Clyde Sea Area, and medusae from it have been reared. The hydroid and the stages of development of the medusa are described and figured. The medusa is commonly present in the plankton in this area.

Observation of Balanus balanoides on the shore at Whitstable shows that at all tidal levels a percentage of the animals maintain a connexion between the mantle cavity and the air by means of a minute aperture or pneumostome. A higher percentage of animals at lower shore levels have a pneumostome than those nearer the top of the shore.

The seasonal changes in the foraminiferid populations along the Tamar-Eddy-stone profile have been shown for the winter, spring and summer of 1962. No single environmental factor appears to be wholly responsible for these changes but temperature is considered to be important. Variable salinities are of secondary importance in the Tamar. These seasonal changes have been compared with those observed at Christchurch and found to be different, presumably because of the different temperature and salinity conditions prevailing in the two estuaries.

A qualitative assessment of the energy input of the environment from the nature of the deposited sediment has shown a good positive correlation between the distribution of the Miliolacea and a high-energy environment. All other superfamilies show a negative correlation with high energy, but the Cassidulinacea show a preference for a moderate-energy environment during the summer.

Foraminiferids, found not to be very abundant in the Plymouth region, show a trend toward greater numerical abundance and greater diversity in passing out o t sea. The shortage of living foraminiferids is tentatively correlated with a restricted food supply.

An electrophoretic study of whole blood samples revealed the presence of haemocyanin and of various other proteins in the blood of fifteen species of marine and terrestrial amphipods and isopods.

The amount of haemocyanin per 1 mm3 of blood is independent of body weight over a range from 10 mg to 1 kg.

Under laboratory conditions and during starvation the haemocyanin level of the blood is lowered as compared with freshly caught specimens.

No relationship between moulting stage and haemocyanin content could be established in three oniscoid isopods, representing Ligia, Oniscus, and Porcellio.

In some species the densities of both haemocyanin and ‘slow proteins’ (i.e. proteins between starting line and haemocyanin) seem to vary in more or less the same direction, over at least part of the total range of variability. In the offshore Conilera, however, an indirect relationship seems to exist between these two protein fractions. This is reminiscent of the situation in Maia squinado described by Zuckerkandl (1960).

The slow protein fractions appear to play a number of roles in the species investigated. In Conilera they consist of various copper proteids (perhaps concerned with the synthesis of haemocyanin?), while in intertidal amphipods and some isopods they carry chromophilic groups that may be of importance in mechanisms of colour change. The colour of the blood of a given specimen of Orchestia gammarella and Marinogammarus marinus depends on the amount of the faster moving, blue chromoproteid present in the blood. These chromoproteids are considered to be carotenoproteids.

The type species of Prasinocladus has been re-investigated in cultured material from the Devon coast and studied electron-microscopically by whole mounts and by sections. Salient findings include: the presence of two layers of scales together with characteristic hairs on all four flagella; the arrangement of the flagellar bases in a row, and of characteristic flagellar ‘roots’; the presence of an unusual condition of the pyrenoid with respect to the nucleus; and the structure and behaviour of the theca as different from that of an ordinary cell wall. It is concluded that the genus could appropriately serve as the type of a group to include all known genera and species of monads containing chlorophyll b that possess scaly flagella, but no recommendations are made as to whether the name Prasinophyceae (Christensen, 1962) should be restricted to these or be permitted to cover other known green flagellates lacking scales on their flagella. This investigation is continuing.

Two phases, cyst and motile, of three species of Halosphaera (Prasinophyceae), H. viridis Schrn., H. minor Ostenf. and H. russellii Parke, sp.nov., are described and the distinguishing characters tabulated. The stages in development of the two phases are detailed and a possible periodicity in their production is suggested. Only the motile phase can persist as an independent form reproducing asexually by fission. Sexuality is not recorded for the genus nor can the reported production of aplanospores be substantiated. The supposed ‘heterokont motile phase of Halosphaera’ of Pascher, who placed the genus in the Xanthophyceae, is believed to be a colourless phagotrophic flagellate parasitizing the cyst phase. All cyst phases, with plain or punctate walls, resembling those of Halosphaera in structure, do not necessarily belong to this genus. The study of living material is therefore essential.