Ill 



grounds and at different times. The same kind of results can, 

 however, be obtained by making direct experiments. Plaice 

 were marked in the Irish Sea in small numbers, the region 

 itself being a small one, and there were two principal series of 

 experiments, in the area just off the estuary of the Ribble and 

 in Red Wharf and Beaumaris Bays. The numbers of fish 

 marked are as follows : — 



(1) Offshore from the Ribble Estuary (" Liverpool Bay ") : 



Total .. 



1,129 plaice. 



(2) In Red Wharf and Beaumaris Bays : 



12th Nov., 1904 42 plaice. 



12th Nov., 1904 

 1st Feb., 1906 

 21st Feb., 1906 

 19th Sept., 1906 

 6th Feb., 1907 

 24th Oct., 1907 

 20th Nov., 1913 



Total 



49 



44 



8 



41 



92 



120 



220 



616 plaice. 



The methods employed were those adopted by the English 

 investigators. The mark was a bone button on the white side 

 of the fish and an oval, concave, hard brass disc on the coloured 

 side. These two marks were connected by a silver wire passed 

 through the body about | inch below the edge of the fin on the 

 dorsal margin. Fixing the mark was very easy, and we were 

 unable to trace any serious injury to the patient. Later on 



