534 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



horizontal fishing, and should be made with Xo. 20 silk 

 for smaller organisms, and with No. 12 or Xo. 3 when 

 larger forms are specially required, since with these 

 latter silks more water will be filtered in a shorter lime, 

 and the catch will be free from the masses of small 

 diatoms, which are not wanted. 



All plankton nets should be fitted with a metal 

 filtering bucket attached to a brass ring, which forms the 

 base of the net, by means of a screw attachment, or by 

 the simple device of a bayonet joint. This bucket 

 consists simply of a brass cylinder, the size varying 

 according to the size of the net ; the lower end is closed 

 by a piece of silk of the same mesh as that used for the 

 net, and attached to the brass cylinder by means of a 

 clamp ring. 



When the net has been used, it is only necessary to 

 wash it down with a few pails of water thrown on the 

 outside, and to unscrew the bucket with the catch. If 

 time is short, and the catch has to be preserved as soon 

 as possible, the silk itself can be removed from the bottom 

 of the bucket, rolled up, and dropped into a bottle of 

 alcohol without removing the organisms; a new piece of 

 silk is then placed on the bucket and it is ready for 

 further use. 



For fishing pelagic eggs, young larval stages of fishes, 

 or when large catches are desired for histological or anat- 

 omical work of large plankton organisms, such as Medusae, 

 very large Copepods, Sagittae, pelagic worms, &c, the 

 German "Brutnetz" is a very successful instrument. This, 

 as the name implies, was constructed for fish eggs and 

 larvae. It is much cheaper than the silk nets, since it 

 is constructed of " cheese cloth," or of good canvas. This 

 is simply a conical net about three metres long, the mouth 

 of which is kept open by a wooden ring of cane 80 to 



