Since the surveys described in our last report (Crisp, 1958) on the distribution in north-west Europe of the immigrant Australasian barnacle, Elminius modestus Darwin, the species has become much commoner along the western coasts and has finally spread to Ireland (Beard, 1957). In this report we present the results of surveys made in 1958–9 along the eastern side of the Irish Channel and in the Isle of Man, as well as full records of a survey of the Irish coast in 1958. The methods employed were similar to those described previously (Crisp, 1958; Bishop & Crisp, 1958).

In May 1958 it was thought that all species of Pogonophora so far discovered in the north-east Atlantic belonged to the genus Siboglinum Caullery (Southward & Southward, 1958). Since then I have had the opportunity of examining further collections from deep water off the British Isles and Spain. At least two species of multitentaculate pogonophores have been discovered, and re-examination of some material collected in May 1958 shows that one of the species was also present in these collections. Although considerable material belonging to other species remains to be worked up it has been thought worth while to describe these two species first. One is widespread and can be locally abundant, while the other is the largest pogonophote so far found in the Atlantic. Both are the first Atlantic representatives of their respective genera.

Apart from the extensive egg surveys carried out by Norwegian workers (Runnstrom, 1941) most of the investigations on the spawning of the Atlantic Herring have depended on studies of the distribution of the spawning fish, on captures of newly hatched larvae, and on records of the occurrence of herring eggs in the stomachs of predatory fish species (principally haddock). With the exception of recent observations by Bolster and Bridger (1957), attempts to sample egg concentrations quantitatively in the North Sea and neighbouring areas have usually proved abortive. In consequence little is known of the distribution and density of eggs on the spawning grounds, their percentage fertilization, mortality during the egg stage, hatching rate, and the relationship between the distribution of eggs and the nature of the sea-bed.

Since MacMunn (1885), the nature and distribution of naphthaquinone pigments in sea urchins have been widely surveyed, and the main findings have been summarized in reviews by Lederer (1952), Fox (1953) and Thomson (1957). Among spinochromes and echinochromes, the most unusual one is the Spinochrome E discovered by Lederer (1952), which is insoluble in ether.

Recently, the author has examined the napthaquinone pigment in the echinoid, Psammechinus miliaris (Gmel.), and has found a similar pigment to Spinochrome E together with other common spinochromes.

Plymouth scad (horse-mackerel) Trachurus trachurus (L.) are known to harbour three species of monogenean trematode gill parasites, of which two belong to the Gastrocotylidae and one to the Microcotylidae. The oncomiracidia (= newly hatched larvae) of these parasites have already been described (Llewellyn, 1957a), but nothing is known of the developmental stages intervening between the oncomiracidia and the adults. Bychowsky (1957) has stated that some information is available about the larval development of 13 monogenean families, leaving 15 families, including the Gastrocotylidae, about whose larval development nothing is known. The ontogenetic development of the Gastrocotylidae is of especial interest since the oncomiracidia are bilaterally symmetrical, but the adults invariably show an extreme degree of asymmetry.

A sea anemone, normally a passive-looking animal, reacts to suitable food-stuffs by a series of fairly complicated activities. When its tentacles encounter solid food there is, first of all, a discharge of cnidae, which poison living prey and adhere to the food mass. These cnidae are independent effectors, responding directly to external excitation (Pantin, 1942). Next, the tentacles clasp the food and bend towards the mouth; they push the food into the mouth, and the pharynx draws it down into the coelenteric cavity where it is digested (Pantin & Pantin, 1943).

In order to evaluate the biological significance of luminescence, it is desirable to know how weak light affects the behaviour of marine animals, and what intensities they can see. Much information is available concerning the attractive power of bright lights, and light directed movements (see Verheijen, 1958, for example), but little for weak point sources. Weak coloured lights have been used by Baylor & Smith (1953) to trap freshwater arthropods.

Pandalus borealis Krøyer is a protandric hermaphrodite. In some populations, e.g. that found off the Northumberland coast, the hermaphroditism is partial (Allen, 1959). That is to say only certain individuals undergo sex reversal, while others are primary females, never going through a male phase; all the males undergo sex reversal. In the terminology proposed by Carlisle (1959 a) such populations exhibit partial obligatory protandric hermaphroditism. By contrast, the population of the Gullmarf jord, Sweden, which I have been investigating, appears to exhibit full obligatory protandric hermaphroditism: the population contains no primary females; all the females have passed through a male phase. The data presented in this paper have no bearing, therefore, on the factors regulating the production of primary females, since I have never encountered one.

In the second paper of this series (Carlisle, 1959 b) I have described the results of various experimental manipulations upon the termination of the male phase in the protandric hermaphrodite Pandalus borealis Krøyer. In this paper I shall be concerned with the effects of such interference upon the initiation of the female phase of the life history.

On 5 November 1958 our attention was drawn, by Mr A. K. Nagabhushanam, to the presence in Port Erin bay of large numbers of swimming gastropods. These gastropods proved on examination to be Pleurobranchus membranaceus (Montagu), a species generally believed to be exclusively benthic in habit. This paper is a report on this occurrence and on some aspects of the biology of P. membranaceus.

For 4 days these animals were abundant in the bay and hundreds could have been captured with a hand-net from the steps of the Raglan Pier. Only approximately forty specimens were taken, this number being ample for our purpose. Between 5 and 9 November, numbers were stranded on the beach by the receding tide. Although many local fishermen consented to look out for these easily recognizable animals, and the Port Erin research vessels were out each day, no record of their swimming outside the bay was obtained, although specimens were occasionally dredged. On 9 November they disappeared from the bay without trace, and otter trawl and D-net hauls in the bay yielded only two further specimens; none were found on frequent shore collecting expeditions. However, on 2 December five more specimens were captured swimming near the Raglan Pier and occasional individuals were seen in the same place on 9 December. During the periods of their abundance it was ascertained that they swam during the hours of darkness as well as in daytime.

When large quantities of bottom soil are brought up by the dredge or grab, the problem of sieving the material within a reasonable time presents itself. The usual practice is to wash the soil through a sieve or series of sieves, the finest being of the order of 1–2 mm aperture, according to the nature of the soil or the size of the animals to be collected. It is usually necessary to agitate the soil either by spraying with a hose or by shaking the sieve in a bath of water, in order that finer particles may pass through the sieve. Many of the more delicate animals are damaged by these methods, and Spooner & Moore (1940), working on the Tamar estuary, found it necessary to mix the mud carefully by hand with water to make a ‘soup’ before it could be sieved without damage to the fauna. For work at sea Hartman (1955) describes a machine by which sieving was accomplished with the aid of water sprays and mechanical agitation of the sieves with power provided by an electric motor.

Investigations of the water movements off the southern Northumberland coast have until now been confined to the surface region. While important for navigational and similar purposes such investigations can give us no more than an indication of the total water flow along the coast nor can they elucidate the effects of currents on planktonic organisms which spend part or all of their existence away from the surface. It is for the latter reason that the series of investigations of sea surface currents made aboard the R.V. ‘Alexander Meek’ in 1956–7 (Evans, 1957) has now been supplemented by further series at two deeper levels.

Recent investigations of the bottom fauna off Plymouth by Spooner (1959 a, b) have revealed the existence of a number of unusual and interesting crustaceans. The copepods collected during this investigation were very kindly placed at the disposal of the writer for study. A careful examination of the collection revealed the presence of a second and new species of Paramisophria Scott. This genus was established in 1897 by Scott on the basis of females collected in Scotland. Sars (1903) described the male for the first time. Paramisophria cluthae, the only species known previously, has been recorded from Plymouth.

As already mentioned (Wilson, 1958), a species of Magelona from clean sand near low water at Mill Bay, Salcombe, has not yet been described. This worm was first noticed in 1939; it is recorded in the 1957 edition of the Plymouth Marine Fauna as ‘Magelona sp.’ and it is there mentioned that artificial fertilizations were made and larvae reared in April-September 1939, and that these larvae differed from those of the other two Magelona species from the Plymouth district (papillicornis F. Müller and alleni Wilson). The worm is still common in the same locality at Salcombe, in the same ground and often in the same spade-full as papillicornis, but it is not as abundant as the latter and probably not as abundant as it was when first seen in 1939. A very good low tide receding below datum is needed to collect it; it is easily overlooked on account of its fragility and fine thread-like appearance, mature females coloured pink by their contained eggs being more readily seen while digging than translucent immature worms or white males. Worms are difficult to collect whole, the tail end usually being left behind in the sand.

The Lutrariidae are large lamellibranchs which burrow deeply in bottom-deposits on the shore and in shallow water. The foot is relatively weak, and they live permanently buried 30 cm or so beneath the surface, maintaining connexion with the overlying water through their long siphons, which are united in a common sheath for practically their whole length. The commonest British species, Lutraria lutraria (L.) is found at low-water mark on shores of muddy sand, and offshore its siphons are sometimes taken by the dredge or grab. Another species, L. magna (da Costa) is more local, and appears to inhabit muddy deposits near the mouths of estuaries. It is a southern form, being occasionally found on the south and west coasts of the British Isles, and, like L. lutraria, its range extends southward to the Mediterranean.

It has been shown (Arnold, 1957) that when exposed to air the common British limpet, Patella vulgata L., reacts to splashing with normal or moderately diluted sea water by raising the front edge of the shell, and that the amount of this movement can be correlated with the degree of dilution and with the tide level from which the animals are obtained. A basically similar result was obtained by the use of solutions of sodium chloride. The precise factors influencing the limpets were not identified. Additional data can now be presented on these and other reactions of P. vulgata as a contribution towards further definition of these factors.

It is difficult to determine the weight or nitrogen content of the living tissues of an operculate barnacle without destroying it. It has been customary, there-fore, in ecological work to express growth in terms of various parameters determined from repeated measurements of the shell. Moore (1934) employed shell volume calculated from the height and basal diameters; others (Costlow & Bookhout, 1953, 1956; Mawatari, Hirosaki & Kobayashi, 1954a, b) have used the area of the basis. Most commonly, however, in growth-rate studies the length of the basis measured through the rostro-carinal axis has been used (Hatton, 1938; Barnes & Powell, 1953). Recently, working with animals cultured in the laboratory when the cast of an individual could be obtained subsequent to ecdysis, Costlow & Bookhout (1957) have used the size of the mouthparts as a measure of growth after first establishing their relation to body size. The space, both areal and volumetric, occupied by a sedentary animal is of primary importance in studies of its ecology and measurements of shell-size are, therefore, adequate for many purposes. For some aspects of growth and ecology it is, nevertheless, very desirable that the relation between such parameters and others, more directly connected with the living material, should be established.

Lepas anatifera L. is generally found on floating objects in tropical and sub-tropical oceanic waters, where sea temperatures exceed 18–200 C.

This note concerns a series of experiments to determine the best conditions of salinity, temperature and pH for cultivating the euryhaline phagotrophic dinoflagellate Oxyrrhis marina Dujardin.

The strain of Oxyrrhis employed was isolated from a brackish pool at Tvarminne, Finland (Droop, 1953a, b). The culture medium for the experiments contained soil extract and an artificial sea water, SW 1 (NaCl, MgCl26H2O, KCl, and CaSO42H2O in the proportions by weight 15:2.5:0.4:0.5), and for food a small quantity of the yeast Saccharomyces exiguus was administered daily from an agar culture with a wire loop.

Oxyrrhis marina Dujardin is a non-photosynthetic dinoflagellate whose obvious mode of nutrition is phagotrophy. The method of feeding was described by Barker (1935). It is an extremely euryhaline and hardy organism and is apparently very successful in brackish habitats such as supralittoral rock pools and ditches (Droop, 1953 a). Owing to the ease with which it can be cultivated Oxyrrhis is a choice for the initial study of phagotrophy among the predominantly plant-like Dinoflagellata.