SEA-FISHERIES LABORATORY. 335 



We have already shown that some unusually large 

 catches were made in the spring of '07, and if we omit 

 that period then the remaining averages range from 0*4 to 

 1*1 c.c. In fact, if three exceptional hauls at the 

 beginning of April, '07, be left out of account, that year 

 would come into range with the others, and the normal 

 catch for this net, pulled through these 10 faths. of 

 water, in April and August together, would then appear 

 to be about three-quarters of a cubic centimetre. The 

 average for April is rather higher than that for August. 



In looking at the details of the numbers of Diatoms, 

 Dinoflagellates and Copepoda (to take only the main 

 groups) for all the Hensen net hauls (all stations) in the 

 three years, one notices far larger quantities of Diatoms 

 (amounting to millions on several occasions) and Dino- 

 flagellates (a few thousands) in the earlier part of April 

 in '07 than in the corresponding period of the other two 

 years; while again, in '09, the phytoplankton was more 

 abundant in the latter part of April than at that time in 

 the previous two years ; but apart from this, there is 

 considerable similarity in the three series. The Copepoda 

 (adults, juveniles and nauplii) especially show substantial 

 agreement. In August the Dinoflagellates are distinctly 

 more abundant in the '08 hauls than in the other two 

 years. 



Nansen Net Hauls in 20 to 10 fathoms. 



In the three years ('07-'09) the Nansen closing net, 

 of 35 cm. diameter at mouth, and made of No. 20 silk, has 

 been used in all 266 times, and of these 141 represent 

 gatherings made vertically in the zone of 20-10 faths., the 

 same number as in the case of the Hensen net. 



At Stat. I, in all, 73 hauls were taken (20 in '07, 

 28 in '08, and 25 in '09) with the results given here; — ■ 

 x 



