12 LIVERPOOL BIOLOGICAL SOCIETY 



Edward Forbes* himself, from his own work and a con- 

 sideration of the observations of others, came to the 

 conclusion that the subzones of his littoral zone (see above) 

 are very well marked on the English coast, and can be 

 distinguished by their characteristic plants and animals, as 

 follows : — First two regions above half-tide mark (1) with 

 Fucus canaliculatus, and the molluscs Littorina rudis and 

 L. neritoides, and (2) with LicJiina, Patella, Balanus, 

 Mytilus ediilis and incrusting nullipores; then a third 

 and very prolific belt at half-tide (3) with Chylocladia 

 articulata and Fucus nodosus, the molluscs Purjnira, 

 Littoriyia littorea, TrocJms tcmbilicakis, and the common 

 sea-anemone; then a fourth above low-water mark (4) 

 with Fuais serratus and the molluscs Littorina ohtusata 

 and Trochus cinerarius, and finally, just at low-w^ater 

 mark a series of four very narrow bands most readily 

 distinguished by their sea-weeds, (5) that of Laureiicia 

 pinnatifida, (6) Conferva rupestris, (7) Chondrus crispns, 

 and ( 8 ) Himanthalia lorea ; this last being the most 

 constant, and being followed by the upper edge of the 

 Laminarian zone, containing Laminaria on rocky coasts 

 and Zoster a on sandy. 



Professor H. de Lacaze-Duthiers has defined on the 

 shore at Koscoff, in Brittany, three zones, viz., (1) that of 

 Fucus, (2) that of Himanthalia, and (3) that of Sargassum; 

 and Professor Giardf has shown that special series of 

 Compound Ascidians inhabit these definite belts. 



About the same time Dr. Leon Vaillant I occupied 

 himself with this subject in the same region, on the 



* "The Natural History of the Euroj)ean Seas," edited by Godwin-Austen. 

 London, 1859, p. 93. 



+ Archives de Zoologie exper. at gener., t. i., 1872. 



X Observ. faites k St. Malo s. 1. zones litt. super., Bull. Soc. Philomat., Paris, 

 nouv. ser., t. vii., p. 144, 1870 ; and Remar. s, 1. zones litt., Soc. de Biologic, 

 Paris, 1872. 



