314 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
because of the feebler draught through that type of net, 
so that less water is actually strained in a given time and 
when towed at a given speed, and also because the less 
rapid inflow at the mouth of the net will allow the 
more active rheotropic forms to escape capture. Hach 
of the twe types of net gives an imperfect result in one 
way or the other. Neither ‘* coarse” nor “ fine” taken 
alone will suffice, and it is necessary to use both nets 
together and add their catches, either actually or 
mentally, in order to have even an approximate idea of 
the constitution of the plankton. 
COARSE NET PUNE SMEs: 
Biddukphia 
Chaetoreres 
Fish &9q9s 
Fic. 14. “omparison of Catches with coarse and fine nets. 
The following list shows the amount of the catch in 
each net on all occasions when both were used together 
as was made the constant practice at Port Erin during the 
latter half of April and from September I1th, 1908, 
onwards, 
