146 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



although, organisms may be widely distributed the 

 relative abundance may change. The distance between 

 Red Wharf Bay and Rhyl is about fifteen miles, and the 

 following tables show the distribution : — 



Red Wharf 

 Bay. 



Biddulphia r. 



Coscinodiscus r. 



Ceratium tripos r. 



Pleurobrachia — 



Sagitta r. 



Autolytus r. 



" Mitraria " r. 



Copepoda c. 



Calanus — 



Pseudocalarms fr. 



Paracalanus fr. 



Temora fr. 



Acartia clausi fr. 



Oithona similis r. 



Euterpina r. 



Plaice eggs — 



)ff Puffin Conway 

 Island. Bay. 



Off m 



fr. . 



.. fr. .. 



r. 

 r. 



r. 



r. 



r. 



v. ab. . 



.. v. ab. .. 



r. 

 r. 



c. 



c. 



c. 



— . 



r. 



— 



fr. . 



.. fr. .. 



fr. 



fr. . 



.. fr. .. 



fr. 



fr. . 



.. fr. .. 



fr. 



fr. . 



.. fr. .. 



fr. 



r. 



r. 



r. 



r. 



r. 



r. 



1 



— 



— 



The collections taken in Red Wharf Bay and off 

 Rhyl show that the plankton was practically the same at 

 the two places. The intermediate stations, however, 

 show important differences. At the extreme ends of this 

 area Diatoms were rare, and only two genera were 

 represented ; Sagitta was also scarce. The plankton in 

 the vicinity of Puffin Island and in Conway Bay contained 

 one of the two genera of Diatoms only, but the increase in 

 the number of specimens was quite conspicuous. Sagitta, 

 on the other hand, constituted the bulk of the inter- 

 mediate gatherings, and it is probable that a shoal had 

 been passed through during these observations. This 

 shoal appeared to be quite limited in width and depth, as 



