424 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



1907 and 1908. They were present in the open sea 

 plankton collected on March 4th, 1907, and again 

 between April 15th and 25th. A few more were found 

 later on in the plankton taken between July 12th and 

 31st. Only one record was obtained in 1908, and that 

 was from a collection made on March 11th. None were 

 noticed in any of the next four years' catches. The oil 

 globule in the egg of the rockling sometimes splits up 

 into a number of smaller ones when the egg is just 

 spawned, but these small globules again fuse into one soon 

 afterwards. It is just possible, therefore, that the eggs we 

 identified as those of the solenette were really the newly 

 spawned egg& of rockling. The characteristic egg of the 

 sole was not noticed in any of the plankton collections 

 taken in the area during the whole of the six years, but 

 we have found them occasionally in the surface plankton 

 from other parts of the Irish Sea. 



Trigla gurnardus , Linn. — Grey Gurnard. 

 Trigla cuculus, Linn. — Red Gurnard. 

 Trigla lucerna, Linn. — Yellow Gurnard. 



The pelagic eggs of the above three species are 

 almost certainly present in the plankton from the 

 south-west area off' the Isle of Man from the end of 

 March to about the latter end of August. There is 

 considerable overlapping in the diameter of the egg and 

 the oil globule of the three species, and it is almost 

 impossible to state definitely which one may be 

 represented at any particular time. The following table, 

 which has been summarised from A. E. Hefford's report 

 in the Marine Biological Association Journal already 

 referred to, shows the amount of variation in the 

 size of the eggs and oil globule of the three gurnards 

 mentioned. 



