SEA-FISHERIES LABORATORY. 419 



fishermen's classes. The spawning period probably 

 extends from the middle of March to the end of April. 

 The egg occurred twice in the plankton collected during 

 1907; first on March 29th, and again on April 10th. 

 In 1908 only one record was obtained, and that was from 

 a surface collection taken on April 14th. The eggs were 

 present in the plankton of 1909 from March 27th to 

 April 24th. They were observed in surface collections 

 taken on March 27th, April 6th, 10th, 15th, 19th and 

 24th. The eggs were not captured in any of the 

 collections made during 1910, 1911 and 1912. 



Psetta laevis, Rondel. — Brill. 



Small and half-grown brill are not uncommon in 

 various parts of the Irish Sea, but full-grown mature 

 specimens are not often met with. The pelagic eggs of 

 the fish appear to be very rare in the area off the south- 

 west of the Isle of Man, as it only occurred once in the 

 plankton collected during the whole six years. The 

 single record was obtained from plankton collected on 

 April 1st, 1907. On that date it was found to be present 

 both in Port Erin Bay and also in the open sea. A 

 single specimen of a recently hatched larva identified as 

 a larval Rhomboid was captured in the surface net on 

 May 2nd, 1910. The eggs are occasionally found in 

 plankton collected in Carnarvon and Cardigan Bays in 

 the early part of July. 



Zeugopterus punctatus , Bl. — Muller's Top-knot. 



The pelagic eggs of one of the top-knots, which is 

 probably the above species, are occasionally met with in 

 the plankton from the south-west area off the Isle of 

 Man between April 1st and July 1st. Muller's top-knot 

 is the one generally captured when trawling is being 



