738 



Fiircellaria fastigiata, Chondriis crispiis, Laurencia pinnatifida, Halo- 

 saccion ramentaceiim, Ceramiiim^ rubriim, Chcvlomorpha Melagoniiim, 

 Porphyra niiniata and P. leiicosticta, Alaria esculenta, Laminaria digi- 

 iata and L. saccharina, especially f. Phyllitis, species of Delesseria, etc. 

 and in general several algae which otherwise grow only in the sub- 

 littoral region. 



Thus it is evident, that a great many different species may be 

 found in the pools; especially in the low lying basins. To show 

 how rich in species such pools may be, we may mention that, 

 according to Rattray (67, p. 428) Traill has found 67 difl^rent 

 species in a relatively small littoral pool in the Firth of Forth. 



It may be pointed out that it is peculiar to the algae-vegetation 

 growing in the pools that the different species often grow irregularly 

 mingled with each other. This is surely due to the absence of tides. 

 In larger littoral pools one may however see the algae forming very 

 distinct belts; various green algae uppermost: Enteromorpha, Clado- 

 phora etc., and farther down Pohjsiphonia , Rhodomela, Chondrus, 

 Delesseria etc. In a littoral pool above the highest water mark, but 

 w^ith clean water, E/7/6ro/7io/*/;/ja intestinalis for instance was found along 

 the edge, next to that a belt of Cladophora riipestris and Cladophora 

 sericea, below that a dense matting of Corallina with small Mono- 

 stroma fiiscum, and lastly Laurencia pinnatifida in great quantities. 



This distribution is most clearly seen in large, deep pools 

 found so far up in the littoral region that the waves can reach 

 them only in stormy weather. In the summer in calm weather, 

 the uppermost layer of water wall turn brackish by the supply of 

 rain and the difTerent layers of water will be distinctly indicated by 

 the vegetation. 



In his report of the littoral rock pools on the west coast of Nor- 

 way, Boye (6, p. 26) also calls our attention to the great differences 

 in the vegetation which correspond with the difTerent heights at 

 which the basins are found. He moreover emphasizes that only 

 Enteromorpha intestinalis is found at the greatest height. He also 

 says that Hansteen's »67i;aceen-formation« (38, p. 346) probabh^ be- 

 longs in part to this vegetation. 



Simmons, who does not give any special report of the vege- 

 tation of littoral pools, says (78, p. 253), when speaking of the » Co- 

 rallina- formaiion^ , that the Corallina msiy abundantly cover the bot- 

 tom of such pools. 



