MARINE BIOLOGICAL STATION AT PORT ERIN. 



65 



quantities of the larger organisms of the plankton such 

 as Sagitta, Medusae, Ctenophora, Zoeas, the larger Cope- 

 poda and some young fishes. 



As a vertical closing net I greatly prefer the Hansen 

 (figs. 7 and 8) to the Petersen-Hensen (figs. 5 and 6). It 

 is lighter and less complicated (a matter of some 

 importance in a rough sea), more easily manipulated, less 

 liable to failure in action, costs less and catches more for 

 its size of opening. The brass cylinder at the lower end 

 is, however, too small, and might be improved in other 

 ways. 



Fig. 9. — Showing by proportional columns the 



range in quantity taken by the various 



Plankton nets in April, 1907. 



The localities to be sampled, all within a ten-mile 

 radius of Port Erin, were — the two " off-shore " stations, 

 No. I. five miles and No. II. 10 miles from Bradda Head 

 respectively, and three " along-shore " stations, Xo. III. 



