378 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



(February 24th), and the rest range from a few tens to 800. 

 There is no marked maximum. The characteristic of the 

 year is the constant presence of the organism in small 

 quantity — which is in marked contrast to the occasional 

 phenomenal appearance of Noctiluca on the coasts of 

 Lancashire and Wales (or no doubt elsewhere also). On 

 the whole it is more characteristic of Noctiluca to be either 

 totally absent or present in great profusion. 



Copepoda. 



We have again taken out the records of the commonest 

 species of Copepoda, and summarise them as follows : — 



Calanus finmarchicus. — There is nothing unusual* 

 about the distribution of this species during 1913. The 

 gatherings are not so large as in 1912, but compare well 

 with other years. The maximum is in July, as has 

 generally been the case, with 4,000 on the 28th. On 

 September 1st there is a large haul of over 3,000. 



P seudocalanus elongatus.- — This species is, as usual, 

 well represented in our nets, being present in every haul 

 taken in Port Erin Bay throughout the year. The maxi- 

 mum is in June (50,000 on the 11th, 68,120 on the 24th), 

 and this year the summer maximum is higher than the 

 autumn one, which only reaches 31,130 on August 28th, 

 and 24,350 on September 22nd. In every other year for 

 which we have records, except 1911, when there was no 

 marked autumnal increase at all, the numbers have reached 

 a higher level in autumn than in summer. 



Oithona similis. — This is again the most abundant 

 species in our nets. The numbers remain very high 

 (usually tens of thousands) from June to September, the 



* Compare the remarks on the distribution of this species on the West 

 Coast of Scotland during the summer of 1913 — See this volume, Herdman 

 and Riddell, p. 312. 



