296 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



On plotting the weekly averages of these six species 

 and drawing curves through them the fact comes out that 

 taking them all together the great elevations are fonnd in 

 the six months May to October and the minima are in the 

 six winter and spring months, November to April inclu- 

 sive. Although the maximum for Acartia is in June, 

 for Temora in August, for Pseudocalanus, Paracalanus 

 and Oithona in October, and for Calanus in July and 

 October, when all are put together it is evident that the 

 Copepoda are a summer and autumn group, and in that 

 respect contrast strongly with the Diatoms, for example. 



A few other less important species which have been 

 mentioned in the previous reports will now be dealt with. 



Anomalocera is practically absent, except for an 

 occasional straggler, up to the end of March; 25 young 

 specimens on the 30th and 10 on the 31st ; 45 and 15 on 

 April 7th in mid-channel; 25 to 30 on the 13th, 14th, 

 15th, 19th, and 45 on the 24th; otherwise the numbers 

 are units and tens. May shows a sudden increase to 300 

 on the 28th, and after 40 on the 1st and GO on the 4th of 

 June Anomalocera is practically absent during the 

 remainder of the year. In '08 it occurred from the middle 

 of April to the middle of September; in '07 it was present 

 in the Bay until November. 



Centropages hamatus is never an abundant form. 

 It is practically absent until May, when it appears in 

 units and tens, reaching 160 at the end of the month, 

 200 several times in June, 300 in July and again on 

 August 2nd, after which the numbers rapidly fall to tens 

 and units again and so remain until the end of the year. 

 This is one of the forms that seem to be commoner in 

 the Bay than in the sea outside. 



Microcalanus PusiLLus, Sars. It will be remem- 

 bered that in this Report, Part I, p. 165, it was 



