408 



Scientific Proceedings, Royal Dublin Society. 



Killeany Bay ; and 5 in the inner part of Ballinskelligs Bay, all soundings between 5 and 

 10 fathoms. In March, 3 in the outer part of Ballinskelligs Bay, soundings 26 to 35 

 fathoms. Fulton, after reviewing his evidence, concludes "that plaice do not spawn 

 in territorial waters on the east coast of Scotland." Our evidence, as far as it goes, 

 shows that this does not hold good for the west coast of Ireland. Owing to the rapid de- 

 clivity of the bottom we meet with no such grounds as the Smith Bank (18 to 20 fathoms) 

 at any considerable distance from land, and must look for their equivalents rather in 

 such grounds as the outer part of Ballinskelligs Bay, and those off the Arran Islands 

 and in the open part of Donegal Bay. The soundings here are about 25 to 30 fathoms.^ 

 I think it very probable that if experiments could be made on these grounds in January, 

 February, and the early part of March, we should find a large number of plaice spawn- 

 ing there. 



LEMON DAB (Lemon " Sole ") — Fleuronectes microcephalus. 



Total number caught, 99. 



Number Examined, 65 — Males, 22. Females, 43. 

 Number approaching Eipeness, 11 — Males, 2. Females, 9. 

 Number ripe, 41 — Males, 19. Females, 22. 

 Number Spent, 13 — Males, 1. Females, 12. 



Table Showing the Distribution in Months. 



The pelagic eggs were taken in the tow-nets in April, May, and June. 



It appears that the spawning period is from March to July, principally in April, 

 May, and June. On the East coast of Scotland, according to Fulton, spawning takes 

 place in May, June, and July, but chiefly in June. 



Distribution of Sp-^wning Fish. 

 Of the 22 ripe females taken, 4 or 5 were in less than 10 fathoms of water; 8 or 9 

 between 10 and 20 fathoms ; 4 between 20 and 30 fathoms ; and 5 at 30 to 40 fathoms. 

 It is noticeable that no ripe females ever occurred in the same haul with spent fish, 

 which were all in the neighbourhood of the 10 fathom line. We have, therefore, 

 evidence of a change of habitat, taking the form mostly of a migration into deeper 

 water (as noticed by Fulton in Scotch waters), in connection with the spawning instinct ; 



1 It appears that plaice do spawn in the territorial waters of the Pentland Firth, 

 where I suppose the declivity of the bottom is more rapid than on the east coast of 

 Scotland. {Vide Ewart & Fulton, 7th Ann. Eep. S. F. B., 1889, p. 188.) 



