SEA-FISHERIES LABORATORY. 241 



early April and a less conspicuous one during the latter 

 half of September. 



The spring hump rises suddenly and falls again 

 almost as suddenly, the main portion occupying about 

 three weeks (the last week in March and the first fortnight 

 in April). It is to be noted that its height is largely 

 influenced by the catches of three days, namely, April 4th 

 (2,369,3-33), April 5th (3,533,800) and April 8th 

 (1,720,600), which were due mainly to the large numbers 

 of Chaetoceros contortum, C. dehile and I'halassiosira 

 nordenskioldii in certain of the nettings included. 

 Omitting these three days, however, the curve retains the 

 same general character as before, except that the peak is 

 very materially reduced. 



The autumn hump is not so well marked, in fact if 

 the catches of the three days, September 12th, 20th and 

 30th, be omitted it almost entirely disappears and is 

 confined to the last week in September ; it depends, 

 moreover, entirely upon surface nettings taken in the 

 Bay. 



At other times of the year the catches were small, 

 reaching, however, about 200,000 now and then sporadi- 

 cally. The minima were during August, October and 

 December, in particular from August 9th to August 20th, 

 when no Diatoms were taken, though surface nettings 

 were made (within the Bay) on all the days with two 

 exceptions. 



DlNOFLAGELLATA. 



The following list of the Dinoflagellata throughout the 

 year is drawn up on exactly the same lines as that for the 

 Diatoms. 







Nets. 



Total. 



Average per 



Jan. 



8 



1 = 













18 



1 = 



100 



100 



Feb. 



5 



1 = 



1,400 



1,400 



