Three new species, Paraserpula planorbis, Omphalopoma stellata and Spirorbis sarsiae, are described and three known species are redescribed. A list is given of the Serpulidae found between 100 and 1000 fm (approx.) and an appendix gives a key to genera of the sub-families Serpulinae and Filograninae

There are three British species of the wood-boring isopod Limnoria. The boreal L. lignorum is found around all coasts, but is least common on the south and west coasts, where the temperate L. quadripunctata is dominant. The latter also occurs in the Isle of Man, Ireland and the Channel Isles, but has not been found on the east coast. The warm-water L. tripunctata is found only on the central south coast and in South Wales. Each species can survive at levels equivalent to 60-65 % exposure, but in mixed populations L. tripunctata dominates the upper level of Limnoria attack, L. quadripunctata dominates the middle zone and L. lignorum is found at the base of exposed piling or sublittorally.

It is shown that sulpholipid is the predominant acetone-insoluble lipid of grass, sphagnum moss, Selaginella, and of some blue-green, green and brown algae.

This sulpholipid is separable into three entities by paper chromatography.

Phospholipid predominates over sulpholipid in red algae, fungi and the fluffy pericarp of the broad bean.

The sulpholipid in these plant tissues gives a single spot on paper chromatogram

A relationship between sulpholipids and photosynthesis is suggested.

The sulpholipid fractions of green and brown algae were isolated by column chromatography, but attempts to repeat the preparation on red algae and fungi by the same methods were unsuccessful.

Fifteen experiments on the foraminiferid Elphidium crispum (L.) are described. They deal with feeding, movement, the substratum, and salinity, and their bearing on ecology.

The daily production of feeding cysts was used as a measure of the metabolic rate and healthiness of the foraminiferids. Phaeodactylum tricornutum, both living and dead, was used as food; a distinct preference was shown for living food. However, kaolin and graphite having a similar size to the Phaeodactylum were also accepted as food. It is suggested that E. crispum selects its food on the basis of size. The colour of the protoplasm is shown to be closely related to the pigments of the food

Movement in the horizontal plane is normally random. However, this species prefers a clean, hard substratum to one of clay; once a specimen has escaped from a clay substratum, it is loathe to return to it and therefore movement in this instance must be directed and not random.

Movement in the horizontal plane is normally random. However, this species prefers a clean, hard substratum to one of clay; once a specimen has escaped from a clay substratum, it is loathe to return to it and therefore movement in this instance must be directed and not random.

The rate of feeding is shown to be closely related to the salinity of the water, the feeding rate decreasing with the salinity. The amount of calcium present in sea water or in subsaline waters does not appear to affect the rate of feeding. However, lowered temperatures help E. crispum to survive for longer periods in subsaline water. At temperatures of 8° and 16° C , cultures survived subsaline water of 20%0 salinity for 38 days, but at a salinity of i5%03 only the culture kept at 8 C survived (for 15 days).

The cell production of sporelings of five species of marine red algae is inhibited by 3-amino-i,2,4-triazole (3AT).

Results show that short-term immersions in culture medium containing 3AT have a lasting effect on the growth of sporelings

This growth inhibitory effect is reversed by addition of adenine.

Protracted contact with 3AT results in some chlorosis of the sporeling

The growth inhibitory effects of 3AT are more marked with sporelings of intertidal red algae than with sublittoral species.

The analysis shows that the diatom community resides mainly in the top 2 mm of the mud and when in bright light the community moves less than 1 mm towards the surface of the estuarine mud, although the colour of the mud changes noticeably.

The fine mud supports more diatoms than the coarse mud, and the community in fine mud is nearer to the mud surface, but this is probably caused by the more rapid extinction of light in fine mud than in the coarse mud, while also large spaces between the coarse mud particles may offer less protection from the effect of tidal scour than in fine mud, this giving contributory explanation for the less abundant community in coarse mud.

An account is given of the populations of P. montagui occurring off the Northumberland coast at depths ranging from 20 to 50 fm. Sampling, which extended from 1954 to 1961, shows that the population in 20–30 fm is composed predominantly of o-group males and females and smaller numbers of 1-group females while that in 50 fm is composed predominantly of 1 and 2 group males and females. This difference can be explained in terms of sex change and migration.

Eggs laid in the period from the last week in November to the first week in January hatch by the end of April. Growth of the new year-group is so rapid that they mature in time for the next breeding season. Egg numbers vary from 200 to 3000.

It can be calculated that the number of larvae hatched out inshore exceeds that offshore by 15 times, but many of the larvae produced by the deep-water.

The compound eye of the lobster H. vulgaris has a single lobe; its ommatidia are uniform except in length. Each ommatidium consists of a corneal facet, two corneagenous cells, four cone cells, a four-part crystalline cone, an elongate cone stalk, seven retinular cells and a four-part rhabdom. Growth between the zoaeal and adult stages is primarily a lengthening of the cone stalk.

In mid-February 1963, a survey of sea temperatures in the western English Channel was made by means of a thermistor towed continuously behind the ship, also by water-bottle samples in a limited area between Plymouth and the Lizard. Evidence is given that surface temperatures, as measured by the thermistor, were representative of the whole water column. Sea temperature records from Torquay indicate that at this time temperatures were near their minimum for this exceptionally cold winter; at Plymouth where sea temperatures are usually more erratic because of estuarine influences the minimum had already been passed. A comparison with data for previous years at Plymouth shows that during January, February and March mean temperatures were lower than in any corresponding month since records were started in 1898.

A re-investigation of fresh material makes it necessary to create the new genus Thalassodrilus for T. prostatus (Knollner). Careful adherence to generic and specific criteria as detailed leads to the recognition of nineteen brackish-water and marine Tubificidae, and some dubious entities are also listed.

Variations in the breeding habits of cirripedes are discussed.

The effect of temperature and light during various stages of gonad development has been determined for B. balanoides.

Constant illumination inhibits breeding, the inhibition relating to the later stages of gonad development.

There is a critical temperature above which breeding will not take place, the level of which may possibly be raised by decreased periods of illumination. A period of 4–6 weeks at less than 12 h of light per day and below the critical temperature is required for maturation of the gametes. It is difficult to advance the date at which egg-masses are laid down by more than a few weeks.

The results are discussed in relation to the animal's ecology. There is a very close adaptation to boreo-arctic conditions; the north-south gradient in the time at which the eggs are fertilized is related to the temperature gradient but the constancy from year to year of this date in any one locality under the same micro-environment cannot be explained on the basis of temperatures. Light periodicity is probably involved.

Previous work on the biology and distribution of Calocaris is discussed briefly. The distribution in Northumberland waters is considered in relation to depth and bottom sediment.

Quantitative monthly samples show that population numbers remain very stable throughout the year. A well marked egg-laying period occurs in January-February when relatively few eggs (average 38) are attached to the pleopods. Eggs are carried for 8–9 months and hatch in September-October. By a combination of size-frequency distribution and gonad-developmnt classification the age-groups in the population are interpreted. After passing through a phase of testes development and spermatophore formation individuals lay their first batch of eggs at the end of the 5th year. The ovaries regenerate over a 2-year period and a second egg-laying takes place at the end of the 7th year with a possible third at the end of the 9th year.

The incidence of soft individuals in the samples together with observed changes in the coverage with epifaunistic growths indicate that after entering the 5th year a single annual moult cycle begins with a slowing down in growth rate.

Population numbers, fecundity and larval survival are discussed. Both the survival curve and the apparent lack of serious predation suggest that the population reaches senescence

Entobdella soleae, a monogenean skin parasite of the common sole was induced to feed on its host. The feeding organ (,pharynx-) is protruded during feeding and encloses a circular area of host skin. The gland cells in the feeding organ produce a proteolytic secretion which digests the epidermis of the fish. The liquid food is then pumped by the feeding organ into the intestinal diverticula, where it is absorbed.

Acanthocotyle sp. from the skin of an elasmobranch fish, Raia clavata, feeds on epidermis in the same way as Entobdella soleae. Observations on other skin and gill-parasitic monopisthocotylineans indicate that the majority of them are epidermis feeders, although there is evidence that some gill parasites, for example Amphibdella torpedinis, may feed on blood.

The evolution of parasitism in the Monogenea is tentatively attributed to the outstanding qualities offish epidermis as a food for a potential ectoparasite and in particular to its rapid rate of regeneration.

Six species of algae, Chlorella marina Butcher, Dunaliella tertiolecta Butcher, Isochrysis galbana Parke, Monochrysis lutheri Droop, Phaeodactylum tricornutum Bohlin and Hemiselmis virescens Droop were fed to oyster larvae in bacteria-free culture. In addition, cultures of Chlorella stigmatophora Butcher, Isochrysis galbana and Phaeodactylum tricornutum containing bacteria were also used. Cultures of galbana containing bacteria were used as controls in all series of experiments. In each series various densities of food, expressed both as cell numbers and as packed cell volume, were fed to the larvae of Ostrea edulis L. for 22–46 h and the change in the mean size of the larval population was used as the index of the value of the food.

The experiments with Chlorella confirmed previous work that organisms of this genus have little value as food for larvae. With Dunaliella and Phaeodactylum growth was better at low food densities with some (but not all) batches of larvae compared with Isochrysis. The comparison of cultures of Isochrysis and Phaeodactylum with and without bacteria showed no consistent improved growth with either food. Monochrysis had about the same food value as Isochrysis. With Hemiselmis some growth was obtained but not as much as with Isochrysis.

Variation in size of fossil euryhaline ostracods is discussed and compared to size variation in recent forms. The most likely cause of variation in size of euryhaline ostracods is variation in salinity. Similarities are indicated between Fabanella and Cyprideis species.

Larger algae and protozoa plankton of inshore waters seem generally well known, except for a few groups of very small flagellates. The same statement cannot be made for the micro-organisms of the bottom sediment-water interfaces and intertidal sand. Many ecologists and physiologists would like to know more about what species and how many individuals can be expected in such locations as these.