i9Qi. WEST. — Notes on the Algcs of Lough Neagh. 87 



sailcloth, and to these were sewn the nets made of the best 

 miller's silk. These nets were attached to the sides of the 

 launch towards and at the stern by ropes several yards in 

 length. The speed used varied from a half to two or even 

 three miles an hour. After about an hour's towing the nets 

 were taken in and the water allowed to drain out naturally. 

 By this means, on turning the nets inside out, a fine greenish 

 sediment was obtained which was scraped off and transferred 

 to small wide-mouthed bottles. The nets were then washed 

 in water contained in a large vessel, and this water was 

 then transferred to large bottles and allowed to stand so that 

 the material desired should be concentrated by subsidence. 

 Total subsidence did not always take place, and the bulk of 

 the material had then to be killed, various means being 

 adopted, chromic acid, trinitrophenol and phenol generally 

 being used for the purpose. Some of the material was kept 

 alive for examination. 



The chief rivers flowing into the lake were also tow-netted, 

 boats having to be used in most cases. The various islands 

 were visited and the algae bordering upon them were collected. 

 Many parts on the borders of the lake were also visited on 

 foot, a boat being sometimes also brought into requisition. 

 Some of the small lakes adjoining were also visited. 



The weather was favourable, and the twelve days spent 

 there were in consequence fully utilised. Nevertheless the 

 time available was insufficient for the completion of the 

 investigation. It is, therefore, arranged that the examination 

 of the lough shall be resumed next summer at a different 

 period — or at different periods — of the year, in order to obtain 

 a more efficient result, as well as to visit those parts of the 

 lake — especially the shores — not yet examined. 



Much time has been given to the examination of the 

 material, and about two hundred species have so far been 

 determined ; a number of these might be termed pseudo- 

 pelagic, occurring in great profusion about the centre of the 

 lake. The investigation shows that there is no lack of minute 

 organisms in all parts of the lake ; these serve as food to larger 

 animals and these to still larger ones, so that eventually there 

 is an ample supply of food for the fish. 



Bradford. 



