Although the high-water Talitridae are normally terrestrial they show little structural modification compared with aquatic amphipods. They have no obvious adaptations to limit water-loss, and their branchial method of respiration is typically aquatic. It was to be expected, therefore, that the evaporating power of the air would play a considerable part in limiting their habitats and determining their habits. The following experiments were made to try and assess the importance of this factor.

The nocturnal migrations of Talitrus over the sand surface cover considerable distances, frequently taking specimens well below mid-tide level. In spite of this, by day the species occupies burrows in a broad, but fairly well-defined, zone in the region of high-water mark. The nocturnal distribution of the animals can be attributed to a somewhat random search for food, but the question arises (worded anthropomorphically), how do the animals find their way back to the high-water region? Perhaps in an attempt to answer this question, Verwey (1929) states briefly that Talitrus orientates on the beach by mnemotaxis to the wind, sun and direction of the sea, and by menotaxis (compass reaction). Mnemotaxis, or orientation by memory images, has been entirely eliminated from the modern classification of orientation reactions (Fraenkel & Gunn, 1940), so that Verwey's contribution is reduced to a statement without evidence that Talitrus orientates by means of a compass reaction to an unknown stimulus, and no other author mentions the orientation of Talitrus on the beach.

In the course of a study of the age and growth of the Common Dragonet, Callionymus lyra L., a number of specimens of another species of Callionymus have been collected off Plymouth, differing from both C. lyra L. and C. maculatus Rafinesque, the only two dragonets previously recorded from the Plymouth area (Mar. Biol. Assoc., 1931), and, indeed, from northern European seas (Andersson, 1942; Day, 1880–84; Duncker, Ehrenbaum, Kyle, Mohr & Schnakenbeck, 1929; Jenkins, 1925; Mohr (in Joubin, 1929–38); Le Danois, 1913; Norman, 1935; Otterstrøm, 1912; Poll, 1947; Redeke, 1941; Sænundsson, 1949; Smitt, 1892–95).

In the Plymouth area there is often a marked and consistent difference in coloration of starfishes (Asterias rubens) from different populations. Starfish from populations to the south of Plymouth Breakwater are red-brown or occasionally pale yellow-brown in colour, whereas those from a population living well within Plymouth Sound have been found to be consistently bright red or brick red in colour (Vevers, 1949). In the present work analysis has been made of the integumentary carotenoids of dark red-brown A. rubens taken from the trawling grounds between Plymouth Breakwater and the Eddystone.

Rees (1949) has established significant biological differences between the two forms of the copepod Calanus finmarchicus, namely finmarchicus and helgolandicus. It is therefore necessary that in future research on the behaviour of Calanus the two forms should be distinguished.

I have myself published observations on the vertical distribution of Calanus and on the seasonal changes in size of individuals of the populations of this copepod off Plymouth. In order to know whether my results have been vitiated by the presence of the two forms in the collections, I have re-examined representative samples of adult females, using the fifth leg as the distinguishing character. The collections in question were those made in 1926 which formed the subject of a paper on seasonal changes in vertical distribution and in the sizes of individuals of different generations (Russell, 1928); and those made in 1931 and recorded in my paper on the vertical distribution of Calanus in relation to light intensity (Russell, 1934).

During the last sixty years many attempts have been made to take photographs underwater at depths varying from just below low-water to many thousands of feet. The pioneer work of Boutan (1893) showed clearly that the essential requirements were a relatively light apparatus fitted with a good source of illumination. Ewing, Vine & Worzel (1946) gave a list of workers who have obtained underwater photographs at wading or diving depths. In their own work Ewing, Vine & Worzel have designed a number of underwater cameras with which they have taken some thousands of pictures of the sea-bottom. In their free-floating cameras the apparatus is allowed to sink to the bottom with a ballast weight. On touching the bottom a trigger sets off the camera which takes two pictures with a time interval of 30 sec. After this the ballast is released and a float brings the apparatus to the surface. In their suspended cameras the component parts are mounted, as in the free-floating cameras, on a vertical pole, with the camera near the top and a trigger at the base. Activation of the camera occurs when the trigger touches the bottom. Their most satisfactory light source proved to be the photoflash bulb. With one or other of these cameras they have obtained large numbers of clear photographs in depths ranging from 10 to 2400 ft., and have used these in studies of bottom deposits, sand ripples, and the distribution of animal life. (See also Ewing, Woolard, et al, 1946.)

Sea water probably contains all the chemical elements, although a number of them have not yet been detected. Considerable information is available on the occurrence of various elements in marine plants and animals, but it is far from complete for any one biological group. Except for recent work by Spooner (1949), on the absorption of radioactive strontium and yttrium by marine algae, no detailed study of the trace elements in the brown algae, nor any attempt to correlate the trace elements in sea water with those in the algae, appears to have been carried out. The following is a brief résumé of the work that has been done in this field.

The larval development of the Cirratulidae is not well known, although an account of the development of Raphidrilus nemasoma Mont, was published by Sokolow in 1911 (under the name of Ctenodrilus branchiata), and of Audouinia tentaculata (Montagu) by Wilson in 1936. Apart from these two publications, only scattered observations may be found in the literature, and these are listed by Wilson (1936). Unfortunately, attempts to rear the larvae of Tharyx marioni (St Joseph) beyond the hatching stage have failed, and as it seems unlikely that further data may be gathered for some time, such results as have been obtained are presented here.

The main points of interest in the development and reproductive habits of T. marioni are: (i) the adults are atoquous; (ii) the eggs are comparatively large and yolky, and unlike Audouinia tentaculata, the pelagic stage is omitted; and (iii the larva on hatching is achaetous, as in other cirratulid larvae.

A specimen of the red mullet (Mullus surmuletus L.), caught in Plymouth waters in October 1949, was found to have tumours projecting externally on the pectoral fins. They were spherical or elliptical in shape, the largest being 20 mm. long. On the suggestion of Mr G. A. Steven some of these outgrowths were cut out and given to the writer for microscopic examination.

When examined fresh they appear to consist of small, spherical, cyst-like bodies of various diameters, but there was no obvious clue as to their nature. After fixing in Bouin and sectioning, they are seen to be composed of cells of various sizes (PI. I, figs. 1–4). It can be seen that these cells lie close to one another, leaving only a little space for the embedding connective tissue which is characterized by the abundance of its own small cells. The blood vessels met with in this tissue contain fish erythrocytes. The whole is covered by stratified squamous epithelium (PI. I, fig. 2).

All the specimens of Autolytus prolifer (O. F. Müller) described here were gathered from colonies of the hydroid Obelia flabellata Hincks, growing on pebbles in a shallow creek in the intertidal zone of the Chalkwell mud flats, on the north side of the Thames estuary. The syllid was found to be very plentiful on this hydroid, living in semi-transparent tubes attached to the stem, but was not found elsewhere.

The specimens agree well with previous descriptions of Autolytus prolifer in the number and arrangement of the pharyngeal teeth, and in the chaetae; but some of the other anatomical features show similarities with other species of Autolytus Grube.

This work was undertaken at the suggestion of Mr F. S. Russell that little was known about the natural history of even so familiar a species as Leander serratus, the common prawn of the English Channel, which may at times form a valuable natural resource to the inshore fishermen. Attention was therefore chiefly concentrated on its growth rate and breeding biology. In spite of the long breeding season the statistical method of studying growth was adopted when preliminary results appeared successful. By this method additional data could be obtained on distribution and migration. In the closely related genus Crangon, growth has been shown to be retarded under laboratory conditions (Nouvel & van Rysselberge, 1937), so that an experimental study could not be relied on to give a picture of the normal life history. Höglund's recent monograph (1943) has treated Leander squilla in great detail. However, this species differs considerably in size and distribution from L. serratus, and it was felt that a similar study in the Plymouth area would not be mere repetition; in fact the biology of L. squilla itself differs somewhat in the two districts.

It is now 25 years since I produced the ‘List of Publications’ in Volume XV of this Journal, which brought the earlier 1913 list up to date.

Much has been published since then and there is an evident need for a supplementary list. Accordingly, Mr N. A. Holme has prepared the following classified list of the contents of Volumes XVI to XXIX of the Journal of the Marine Biological Association and of other pubhcations recording the results of researches carried out at the Plymouth laboratory from 1928–1950.

In a survey of the British species of Gammarus inhabiting estuarine waters (Spooner, 1947), it was found necessary to divide G. zaddachi Sexton into two well-marked morphological forms, with different salinity optima, which in fact behave as distinct species. They were, however, on account of their similarity in important structural features, retained as a single species and named G. z. zaddachi and G. z. salinus respectively. At the time little could be said about a third subspecies, essentially marine in its distribution (but ranging into brackish water), which Segerstråle (1947) independently described as G. z. oceanicus.

After the monograph on Leander squilla by Höglund (1943) in Sweden, any further work might seem repetitive; however, at Plymouth some differences in the biology of this species have been noticed, as might be expected from the different climates. It has been thought worth while to record these additional notes on the age and growth, together with records of the food.

De Man (1915) has separated the Scandinavian population as the forma typica from those of Holland, France and Britain, which he grouped into the variety intermedia, the only distinctive character being the length of the carpus of the second leg relative (either longer or shorter) to that of the chela. It is not known whether the two forms intergrade.

Silicon in sea water may be present in suspension, in particles of clay or sand, as a constituent of diatoms, etc., or in solution. Some silicon in solution occurs in the form of silicate. This is usually estimated by the colorimetric method of Diénert & Wandenbulcke (1923), which makes use of the yellow colour of the silicomolybdic acid which is formed when ammonium molybdate and sulphuric acid are added to the water (Atkins, 1923). The colour may be compared with that of standard solutions of picric acid (Diénert & Wandenbulcke, 1923) or potassium chromate (Swank & Mellon, 1934). The method is simple but the colour in sea water is often faint and is not easy to match visually, nor is its intensity strictly proportional to the concentration of silicate. Less colour is produced in sea water than in standard solutions made with distilled water and this ‘salt error’ must be allowed for (Brujewicz & Blinov, 1933; Wattenberg, 1937; Robinson & Spoor, 1936).

The Dublin Prawn or Norway Lobster, Nephrops norvegicus (L.), is widely distributed on soft muddy bottoms, usually between 10 and 50 fathoms. It is found as far north as Iceland and the North Cape, is common in the North Sea and off the Atlantic shores of the British Isles, and extends as far south as the coast of Morocco; a variety, v. meridionalis (Zariquiey-Cenarro, 1935) is found in the Mediterranean and Adriatic (see Havinga, 1929, and Heldt & Heldt, 1931, for details of its distribution). Some aspects of the general biology of Nephrops have been dealt with by Höglund (1942) and Poulsen (1946) for Scandinavian waters, and by McIntosh (1904, 1908) and Storrow (1912)for the waters off north-east England. To a large extent all these workers relied on market catches.

The general biology of the common starfish, Asterias rubens L., has recently been studied by Vevers (1949), whose investigations included observations on the growth-rate of this species. His material was collected in the Plymouth area largely by means of an otter trawl, supplemented by a few Agassiz and dredge hauls, and there are therefore few records in his data of the growth-rate of juvenile A. rubens under natural conditions. Vevers also made observations on the growth-rate of individuals kept in laboratory tanks, but again the results apply mainly to fairly large animals. The only other direct observations on growth-rate appear to be those of Bull (1934), who dealt with three small individuals kept in aquarium tanks, while Orton & Fraser (1930) give measurements made on a natural population taken, after one year's growth, from a buoy.