Tyne Salmon Conservancy) to do all they can to prevent poisonous 

 effluents being poured into tlie river, and to see that poisonous 

 products are not deposited on the banks. 



An important step has been taken as to the formation of the 

 mussel beds at Holy Island. Arrangements have been made for 

 obtaining a lease of the area, and it is hoped that a beginning 

 will be made in transplantation this season. 



A paper on the Crustacea is meant to draw attention to the 

 confusion which exists regarding larval nomenclature, and 

 especially to bring together the knowledge we possess as to the 

 growth and the age of various species, based mainly on the series 

 obtained by G. Brook and Mr. Waddington. The statement 

 shows that the Decapod Crustacea only reach maturity after 

 about four to five years from hatching, and that the crab and 

 lobster, for example, may reach an age which cannot be said to 

 be less than 20 years. 



Miss Olga M. Jorgensen, M.Sc, contributes a series of papers 

 on the work she has been engaged in during the year. The 

 first gives the results of an examination of the water of the tanks 

 of the Cullercoats Laboratory, with a view to indicating the 

 nature and the quantity of the micro-plankton of the water 

 supply, and incidentally the changes in the micro-plankton of 

 Cullercoats Bay. It is shown that the tanks and the sea 

 undergo the spring and autumn increases so generally observed 

 in the North Atlantic region, but it is plain that the maxima 

 are intensified by the accumulation of plankton in the tanks 

 between the periods of pumping. The results, therefore, do not 

 give a true picture of the sea plankton, but they give an in- 

 teresting and important indication of the monthly variation of 

 the micro-plankton of the tanks and the lists of species will be 

 found to be of great value. 



Aviphidinium operculatnm, which was recorded for the first 

 time in 1913 and has appeared irregularly since, was found in 

 1917 and 1918 from November to May. It has thus, so to speak, 

 become established at Cullercoats as Herdman has found it to 

 have been at Port Erin. 



