Marine biological station at tort krin. 73 



During the recent summer vacation (August 9th to 

 September 20th, 1907) with the assistance of Mr. 

 Buchanan- Wollas ton and others, I again worked the 

 plankton nets on every possible opportunity from the 

 s.y. " Ladybird," trying to make a still more intensive 

 study of a limited district. On this occasion over 300 

 gatherings were taken in 30 days, an average of 10 per 

 day. On one trip (September 20th) 36 gatherings were 

 taken in an afternoon, in a small area of only about two 

 miles extent, as follows: — 



Locality A : — 6 miles out, W.N.W. of Bradda, over 30 fms. 



1. Hensen and Nansen nets let down to 30 fms. and hauled up 10 fms. (30-20). 



2. „ „ „ 20 fms. „ „ 10 fms. (20-10). 



3. „ „ „ 10 fms. „ „ 10 fms. (10-0). 



3Q to. „ „ IS^J- (30-0) 



Weighted open net (A) and two surface nets (Al and A2) along with shear net 



(Sh. 1) at 15-20 fms. 

 Weighted open net (B) and two surface nets (Bl and B2) along with shear net 



(Sh. 2) at 7-8 fms. 

 (These each ^-hour hauls ; the one set taken immediately after the other,) 

 Mill water bottle at 20 fms., strained at the time. 

 ,, „ at 20 fms., strained on shore. 



Locality B : — 8 miles out W.N.W. of Bradda, over 30 fms. 



1. Hensen and Nansen nets let down to 30 fms. and hauled up 10 fms. (30-20). 



2. „ „ „ 20 fms. „ „ 10 fms. (20-10). 



3. „ „ „ 10 fms. „ „ 10 fms. (10-0) 



4. Nansen (alone) „ „ 30 fms. „ ,, to surface (30-0). 

 Weighted open net (C) and 2 surface nets (CI and C 2) along with shear net 



(Bl) at 7-8 fms. 

 Weighted open net (D) and 2 surface nets (Dl and 1)2) along with shear net 



(B2) at 15-20 fms. 

 (These each ^-hour hauls ; the one set taken immediately after the other.) 

 Mill water bottle at 20 fms., at 10 fms., and at 5 fms. 



The object I had in view on most occasions was to 

 sample the various layers of water, as well as to compare 

 neighbouring localities and adjoining dates, and the 

 following diagrammatic statement of certain of the hauls 

 taken on September 12th will illustrate the plan of 

 work adopted to differentiate the zones : — 



