The leopard-spotted goby, Gobius forsteri Corbin 1958, described from the western English Channel, is identified with the Madeiran Gobius ephippiatus Lowe 1839, the latter name becoming a senior subjective synonym for this species. From study of variation, with size of fish, in number of lateral-line sensory papillae in preopercular-mandibular row i, it is concluded that the Aegean Gobius thori De Buen 1928 may also be referred to G. ephippiatus. Examination of the syntypes of G. macrolepis Kolombatovic 1891, from the Adriatic, has shown that this name belongs to a close relative of G. ephippiatus and not to Mediterranean populations of the Atlantic Lesueurigobius friesii (Malm), as recent authors have supposed. A new genus, Thorogobius, is proposed for G. ephippiatus, the type species, and G. macrolepis, and a key provided to these two species, which differ in meristic features, development of pelvic anterior membrane and disc, head coloration, and relative number of sensory papillae. Further systematic data on material studied, synonymies, body proportions, papillae and meristic counts are also given.

As the complete list of known occurrences indicates, T. ephippiatus appears to be a warm temperate Mediterranean-Atlantic form which penetrates the eastern Atlantic boreal region around the British Isles at least as far north as the North Channel and eastwards to Lulworth Cove (western English Channel). As an inshore shelf species, T. ephippiatus occurs in or near crevices associated with vertical rock faces, from LWST to 30–40 m. Diet probably consists chiefly of crustaceans and polychaetes. Maximum total length recorded is 129 mm, and greatest age 9 years (determined from otoliths), with sexual maturity by the fifth year of life (age 4 +).

The relationship between the calcite skeleton and associated cells in the spines of Echinus esculentus is described. The cell bodies lie in channels within the skeleton and cytoplasmic processes extend from them toward the calcite. Swollen regions of the cytoplasmic processes contain organelles such as mitochondria and various vesicles. The plasma membranes of the cytoplasmic processes appear to spread over the calcite surface which is thus topologically intracellular. A considerable portion of the stereom space is extracellular and contains an extracellular fluid and collagen fibres.

On the basis of extensive material from Plymouth an attempt has been made to determine the specific limits of the European species of the eolid genus Eubranchus Forbes. From a study of the living animals, jaws, radulae and reproductive systems, it is concluded that five species can be recognized as occurring commonly in Britain, Eubranchus tricolor Forbes (=Galvina viridula Bergh), E. farrani (Alder & Hancock), E. pallidus (Alder & Hancock), E. cingulatus (Alder & Hancock) and E. exiguus (Alder & Hancock). These species are all variable in coloration, but they can nevertheless be easily distinguished by coloration as well as by morphological and ecological characteristics. A further species, E. doriae (Trinchese) from the Mediterranean, was also examined and appears to be distinct. No material of Eubranchus rupiurn (Moller) and E. vittatus (Alder & Hancock) was available for examination, but these are provisionally maintained as distinct species. The European species of Eubranchus are compared with species from other parts of the world in an attempt to decide how many genera should be recognized. It is concluded that the armature of the penis and the liver branching do not form good generic characters, and that consequently Capellinia is to be regarded as a junior synonym of Eubranchus.

The density of 18 species, measured by weighing them in sea water and in air, was found to vary widely. The weights of these fish in sea water ranged from about 7 % to less than 1 % of their air weights.

Studies made on the cod of the Barents Sea showed that in the adult female fish there were regular seasonal variations in the level of calcium and vitamin A aldehydes in the blood (Plack & Woodhead, 1966: Woodhead, 1968). These changes were directly related to each other (Woodhead & Plack, 1968) and it was suggested that the changes of both blood constituents might be influenced by oestrogen secretions from the ripening ovary. It has now been confirmed that oestradiol treatment increases the level of vitamin A1 aldehyde in immature cod (Plack & Pritchard, 1968), and the present paper describes the effect of oestrogen treatment on the concentration of calcium in the plasma, also relating this to vitamin A aldehyde changes.

A new midwater trawl based on that designed by Tucker (1951) is described with details of opening and closing equipment, acoustic release gear and depth telemetering pinger. An account is given of the method used in operating the xtrawl from R.R.S. ‘Discovery’.

A collection of 185 cephalopods from near the southern end of Fuerteventura(Canary Islands) consists of 18 species and 13 unidentified larval specimens. The collection is particularly interesting because the use of modern closing nets and depth monitoring gear has thrown new light on the depth distribution of some of the cephalopod species concerned. Diurnal migration is described for several oceanic cephalopods for the first time.

Total phosphorus and total nitrogen excreted by freshly-caught Calanus finmarchicus (Gunnerus) and C. helgolandicus (Claus) collected from the Clyde and Plymouth Sound have been measured during spring, summer and autumn. The quantities of phosphorus and nitrogen present in animals, plant foods and faecal pellets have also been determined.

Analysis of grab samples from the shallow-water sand community (0—6 m) in the northern Irish Sea has shown that there is an increase in the diversity and in the abundance of amphipod species westwards. The most frequently occurring and the over-all dominant species is Bathyporeia elegans. Six indicator species (Ampelisca brevicornis, Bathyporeia guilliamsoniana, B. elegans, B. nana, Perioculodes longimanus and Pontocrates arenarius) with a high degree of association are present in varying proportions throughout the community.

Descriptive work carried out in two localities at Port Erin, Isle of Man and three localities at Lough Ine, County Cork has shown that there were marked morpho-logical and anatomical differences between sporophytes of Saccorhiza polyschides (Lightf.) Batt. living in different habitats. The plants developed broad, flimsy, curved, non-digitate blades in areas of weak current; long, tough, flat, very digitate blades in strong current and short, tough, flat blades with few digits in habitats without current, but subject to wave action. By means of culture techniques in the laboratory and transplant experiments in the sea the variations were shown to be phenotypically based. The transferred plants adopted the morphology of the population into which they were moved.

Thin-layer chromatography on plates coated with silica gel and with sucroseglucose (1:1) has been used in the study of the pigments of twenty species of marine phytoplankton from four phyla. A number of apparently new xanthophylls have been found, including a fucoxanthin-like pigment which is the major xanthophyll in an unidentified coccoid alga (Plymouth no. 407).

The regulation of total algal numbers in the symbiosis involving Anemonia sulcata and a marine dinoflagellate has been investigated in a series of experiments designed to test the effects of starvation and/or darkness on the host and its alga. The gross effect of these conditions (either separately or in combination) is detectable as a generalized weight loss in the symbiotic system. An electronmicroscopical study has shown that this weight loss can be directly related to changes in the ultrastructural morphology of both Anemonia and its symbionts. The significance of these findings is discussed in relation to current knowledge of the nutritional aspects of algal—invertebrate symbiosis.

The effects of oil-spill removers (‘detergents’) on a population of the dogwhelk Nucella lapillus have been studied at Porthleven in South Cornwall, where heavy oil pollution occurred following the ‘Torrey Canyon’ incident in March 1967. Nucella is one of the shore animals which are most resistant to ‘detergent’ treatment, but at Porthleven the species was wiped out in the harbour and the majority of animals were killed on the reef nearby.