The hitherto unknown hydroid of the anthomedusa Bougainvillia pyramidata has been found in the Firth of Clyde, and medusae from it have been reared to maturity. The hydroid and the stages of development of the medusa are described and figured, and the species is compared with B. ramosa. The seasonal occurrence and distribution of the medusa are discussed.

The hydroid Bougainvillia muscoides (M. Sars) has also been found in the Firth of Clyde. Medusae have been reared from it, and a description, with figures, of the stages of development is given. The specimens found in 1901 in this area and described by Browne as Thamnitis sp. are shown to be young medusae of B. muscoides. The geographical and bathymetric distribution of the species and the seasonal occurrence of the medusa are described and discussed.

The Preliminary Check-list (Parke, 1953), with the three subsequent lists of additions and corrections (Parke, 1956, 1957, 1959) was intended to provide a fundamental basis for the preparation of a Flora of the British marine algae sponsored by the British Phycological Society. Changes, both taxonomic and systematic, have been so numerous in recent years that a new Check-list is now necessary for the six Classes dealt with in 1953. Five additional Classes, marked below with an asterisk, are also included in the new list. As there is still controversy regarding the status and arrangement of the major algal groups they are here given, as in Parke (1953), the rank of Class.

A new species provisionally attributed to the genus Nephroselmis has been described with the aid of light- and electron-microscopy. Significant features include the presence of a single layer of scales over the flagellar and cell surfaces as in Micromonas squamata Manton & Parke, though the morphology of the flagellar scales is as in the outer scale layer of Pyramimonas and Halosphaera. Reasons are given for rejection of Thalassomonas on the grounds of nomen confusum and for homologizing various representatives of it with Micromonas squamata.

Some additional facts about the latter include details of the imbrication of the flagellar scales and demonstration, made possible by the use of lead staining of sections, of a close association between golgi bodies and the scale-producing vesicles.

1. A study of the histology of the eyes of some cartilaginous fishes has been made with special reference to their reflecting tapeta.

2. The rate and way in which the pigment in the melanophores spreads over the reflecting cells of the tapetum of Squalus acanthias when it is lightadapted are described.

3. The reflecting plates in the tapeta are about parallel to the plane of the retina in the centre of the eye, but as we move towards the periphery they become more oblique, until near the ora they are almost perpendicular to the plane of the retina. It is shown that when we take account of the way in which the pupil limits the light which can reach the retina in all these situations the plates are arranged to be roughly perpendicular to the incident light. They reflect light either back through the pupil or on to the very black inside surface of the iris and do not scatter it to other parts of the eye.

4. The reflectivity of tapeta for various angles and various wave-lengths of light has been found by several different methods, and a new and simple way of measuring the reflectivity of natural tissues is described. For the blue and green lights which will be those reaching the eye in life the reflectivity is very high, over 80%, and so approaches that of a good metallic mirror.

5. The external segments of the retinal rods of cartilaginous fishes which have well-developed tapeta are only about half as long as those of other fish living in the same environment, and the retinal optical densities of photosensitive pigments in these fish are only about a half of those of fish without reflecting tapeta.

The uptake of 134Cs by 36 species of marine and freshwater fish and shellfish has been measured, and for selected species has been shown to depend on a power of the weight. For plaice, lobster, and eel, over thousand-fold ranges of weight, the uptake varies according to ω0.78. The times taken to reach half-equilibrium concentrations vary according to a value between ω0.25 and ω0.29, e.g. for a 100-fold increase in weight there is a 3.5-fold increase in half-value time.

The Council have to report with regret the deaths of Captain V. Lord, a member of the Association's staff for 28 years and well known to many workers at the laboratory as skipper of S.S. ‘Salpa’; and of Cdr. C. A. Hoodless, D.S.C., R.N.R. who was Master of R.V. ‘Sabella’ from 1948 to 1953 when he was appointed Master of the Association's new research vessel ‘Sarsia’. Cdr. Hoodless was an able and skilful seaman and did much for marine science. His burial took place at sea from R.V. ‘Sarsia’ on 16 March 1964.

The Council record with great pleasure the award of the 1963 Nobel Prize for Physiology and Medicine to Prof. A. L. Hodgkin, F.R.S., and Prof. A. F. Huxley, F.R.S. Both have been visiting research workers at the Plymouth laboratory and Prof. Hodgkin has served many times on the Council of the Association.

The Council and Officers

During the year Major E. G. Christie-Miller resigned from his position as a Representative Governor on the Council of the Association since 1941. Major Christie-Miller gave devoted service to the Association as Honorary Treasurer from 1941 to 1956, and had been a Vice-President since 1951.

Col. Sir John Carew Pole, Bt., D.S.O., T.D., has been nominated by the Fishmongers' Company in his place.

Four ordinary meetings of the Council were held during the year, two in the rooms of the Royal Society, one in the rooms of the Linnean Society and one at Plymouth. At these the average attendance was seventeen.