SEA-FISHERIES LABORATORY. 233 



of catches on an off-shore station, the Nansen being 

 greater than the Hensen and the three open nets being 

 greater still, while the weight net has caught more again 

 than those on the surface. Form 42 on the second 

 off-shore station at the same date shows a very similar 

 proportion between the catches. Many other similar 

 examples might be given. On the other hand, there are 

 cases, such as station III on April 4th, when the Hensen 

 and Hansen brought up such enormous quantities of 

 Diatoms from the lower zone of water as to outnumber 

 many times over the catch of all the other nets put- 

 together. On this occasion, the Hensen nets caught 

 64*5 c.c. and the Xansen 1(>4 c.c, and several numbers of 

 individual species of Diatoms in a single net run into 

 millions, Chaetoceros contortion being estimated at fifteen 

 millions in the Hansen net. On the following day at the 

 second off-shore station the number of that Diatom is 

 estimated at fourteen millions and the total amount in 

 the Hansen net was 100 c.c, while the Hensen had only 

 12*5 c.c. The surface nets were 9 and 12 respectively, 

 and the weighted net 15*5 c.c. 



Although the numbers are not so high in the case of 

 other groups, the same general principle holds later in 

 April, when the Diatoms are disappearing and the 

 Copepods are more abundant. We find that the Nansen 

 net still obtains a much larger catch, and that the bulk of 

 it is then made up of adult and larval Copepoda. For 

 example, on April 22nd, at off-shore station I, the Nansen 

 catch was c.c. and the Hensen 1 c.c. The Nansen had 

 2,250 Copepoda and the Hensen 185; the Nansen had 

 15,000 Copepod Xauplii, and the Hensen 3,000 ; the 

 Xansen had 1,500 later Copepod larvae, and the Hensen 

 had 250 ; the Hansen had 1,000 Oikopleura, and the 

 Hensen 125. Many other similar examples might be given. 



