198 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Material Available. 



The collections made this year have amounted to 

 over 500 — within the limited area off the Isle of Man to 

 which this " Intensive Study " applies. This series 

 compares with those of former years, as follows: — 





At Sea, 



from Yacht. 



In Bay 



throughout 



Year. 



Totals. 





Spring. 



Autumn. 



1907 

 1908 

 1909 

 1910 

 1911 



218 

 156 

 329 

 107 

 120 



279 

 242 

 147 



249 



84 



138 



157 



231+49 



296 



314 



635 

 555 

 756 

 652 

 518 



Totals ... 



930 



1,001 



1,185 



3,116 



These make about 1000 in each of the three vertical 

 columns — Spring, Autumn and Bay — and from over 500 

 to over 750 for each of the five years in question. 



The remarks made in the previous Reports about the 

 nets used and the methods adopted apply again ; but for 

 the vertical hauls we have used almost wholly the Nansen 

 net, either open throughout the haul or closed after 

 traversing a certain zone. The other nets used were 

 "coarse" and "fine" (No. 

 "funnel" net, "Otter" net, 

 "large Nansen," and "Shear' 

 and the methods in which we use 



20 silk) horizontal, 

 " medium Nansen," 

 net. All these nets 

 them have been 



sufficiently described in the previous parts of this study. 



PLANKTON OF PORT ERIN BAY IN 1911. 



The plan adopted for the last few years in regard to 

 the plankton samples from Port Erin Bay has been to 

 take two horizontal (coarse and fine nets) and one vertical 

 haul twice each week throughout the year — thus giving 



