SEA-FISHERIES LABORATORY. 



163 



and that variation may be considerable at another date. 

 On successive days one may even find that the quantity 

 and kind of organisms undergo changes more or less 

 marked. 



On April 6th one tow-netting was taken in Port Erin 

 Bay and another off the Calf Island. These show a certain 

 amount of similarity. 



Port Erin 

 Bay. 



Biddulphia ab. 



Chaetoceros c. 



Coscinodiscus v.ab. 



Rhizosolenia * — 



Acanthometra r. 



Ceratium tripos r. 



Ceratium fusus r. 



Sagitta r. 



" Mitraria " r. 



Nauplii of barnacles c. 



Crab zoea r. 



Copepoda c. 



Pseudocalanus fr. 



Temora fr. 



Centropages r. 



Acartia fr. 



Oithona fr. 



Whiting eggs — 



Gurnard eggs r. 



Sprat eggs r. 



Rockling eggs r. 



Common Dragonet r. 



Off Calf 

 Island. 



ab. 



c. 



v.ab. 



r. 



Diatoms and Copepoda had a uniform distribution in 

 these areas at this time, but the other organisms 

 mentioned were evidently limited to Port Erin Bay. 



A few days later considerable variation was found in 

 the plankton in Port Erin Bay and its immediate 

 neighbourhood. On April 9th one sample was collected 



