162 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



visitation had extended to the Isle of Man. The most 



abundant form along the North Wales coast was 



Coscinodiscus, while Chcetoceros was the most conspicuous 



at Port Erin. Sagitta was extremely plentiful off 



Puffin Island, and tolerably common in Llandudno Bay 



and at Port Erin. Copepoda had increased in quantity 



in the coastal area in the course of six weeks, and were 



also abundant at Port Erin. 



On November 1st one collection was made at the 



entrance to the Ribble and another in Red Wharf Bay. 



These show that Diatoms were widely distributed in the 



territorial area. 



Entrance to Red Wharf 



Ribble. Bay. 



Coscinodiscus c. ... c. 



Rhizosolenia r. ... r. 



Ceratium tripos c. ... c. 



Ceratium fusus c. ... — 



Noctiluca c. ... c. 



Sagitta r. ... c. 



Crab zoea — ... r. 



Crab megalopa — ... r. 



Copepoda c. ... ab. 



Calanus — ... r. 



Pseudocalanus — ... c. 



Paracalanus — ... ab. 



Temora c. ... c. 



Centropages c. ... r. 



Oithona c. ... c. 



Copepoda appeared to be more plentiful in Ped 

 Wharf Bay than at the entrance to the Pibble, and there 

 was also a greater variety at the former place. The 

 other constituents of the plankton differed very slightly 

 in the two samples. 



Two or more surface tow-nettings taken in the vicinity 

 of Port Erin on the same day also show that the plankton 

 may be almost identical at different spots at one period, 



