SEA-FISHERIES LABORATORY. 411 



month, but was not observed after June 19th. The 

 records obtained during- the years 1910 and 1911 are 

 almost identical with each other. It was first noted on 

 June 3rd, 1910, and disappeared after September 17th. 

 The eggs occurred on June 5th in 1911, and were not 

 observed after September 19th. They were present in 

 every collection taken with the surface nets between the 

 dates mentioned in each of the two years, i.e., a period 

 of well over three months. The egg of the sprat did not 

 make its appearance in 1912 until July 8th, and was not 

 observed after the end of that month. 



The pelagic larvae were not often met with in the 

 plankton, but when present were usually more abundant 

 at the end of April than at any other time covered by 

 the spawning period. It appears rather strange that the 

 larvae were more common in the plankton of the area in 

 1908, one of the years containing a single record of the 

 egg, than in 1910 and 1911. A surface collection taken 

 on April 22nd, 1908, contained 130 larvae, and another, 

 taken on April 23rd, contained 329 larvae. Only four 

 larval sprats were obtained in 1910, and these were from 

 a collection made on September 16th. No larvae were 

 observed during the whole of 1911. The larvae were not 

 taken in the area after the end of September in any of 

 the six years, although we have found post-larval sprats 

 18 to 25 millimetres in length in the plankton collected 

 off the North Wales coast as late as the first week in 

 December. 



Gadus callarias, Linn. — Cod. 



The pelagic eggs of this valuable food fish occur in 

 the plankton of the area between the end of February 

 and beginning of May. In 1907 the eggs were not 

 observed until March 29th, and the last date on which 



