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Proceedings of the Royal Physical Society. 



XV. On Branches of Ascophyllum. 

 Littorina ohtusata (L.). Few. 

 Hyale nilssoni (Rathke). 

 Gammarus marinus, Leach. 

 J (Era alhifrons, Leach. 

 Idotea granulosa Rathke. 



V. On Fucus platycarpus. 



Littorina rudis (Maton). Few. 



„ ohtusata (L.). Few. 

 Hyale nilssoni (Rathke). 

 Gammarus marinus, Leach. 

 Jcey^a alhifrons, Leach. 

 Idotea granulosa, Rathke. 



ZONE 2— UPPER HALF. 



B. Where fresh water percolates, 

 i. Under Stones. 



Actinia equina, L. 



Sagartia troglodytes, Johnst. Young. 



Procerodes ulvce (Oersted), and Cocoons of this species. 



Enchytrseids. 



Mytilus edulis, L. 1 inch and smaller ; very abundant. 

 Littorina rudis (Maton). 



„ littorea (L.). Full-sized, and young. 

 Purpura lapillus (L.). 

 Various Ostracods. 

 Balanus balanoides (L.). 

 Gammarus marinus, Leach. 



J(E7'a alhifrons, Leach. Adults and young ; very abundant. 

 Idotea granulosa, Rathke. 



Carcinus mcenas (Penn.). 50 mm., and smaller. 

 Dipteron larvae. 



ii. In Substratum (Shell Gravel). 



Polystomella crisjm, L. Empty tests ; fairly abundant. 

 Cocoons of Procerodes ulvce. 

 Psainmoryctes costatus (Clap.). 

 Enchytrseidse. 



Mytilus edulis, L. Half-grown. 



