745 



in Greenland. It seems to me most likely that the somewhat dif- 

 ferent occurrence of these two species, also in the Faeroes, may 

 be explained thus, that Fuciis uesicnlosus, as mentioned before, 

 requires to be more sheltered than the other; therefore, this alga 

 in a somewhat exposed place grows facing landward and upj)er- 

 most, whilst it may grow nearer to the sea and farther down in a 

 locality as sheltered as Vestmanhavn. 



Fig. 157. Fuciis inflatiis-as^ocialion at a small, low-lying pool on the beach. 

 Illustrations from rocky coast at' Thorshavn. (F. B. phot.). 



Elachista fiicicola is a very common epiphyte on Fiicus vesicii- 

 losiis, and Pohjsiphonia fastigiata is hardly ever sought in vain on 

 AscophijUiim nodosum. Besides these, other epiphytes are sometimes 

 found e. g. Ectocarpiis litoralis, Edocarpiis tomentosiis , Ceramiiim 

 rubrum, Rhodymenia palmata etc. on both algae. Below the dense 

 tufts of seaweeds several red algae are often found, e. g. Gigartina 

 mamillosa, Chondriis crispus, Hildenbrandia rosea, Rhodochorton 

 Rothii, etc. 



On a somewdiat more exposed coast, Fuciis vesiciilosiis , as be- 

 fore mentioned, soon disappears and is replaced by Fuciis spiralis 

 which forms an association at about the same height as Fuciis 

 vesiciilosiis , or a little higher. Below Ascophijllum nodosum, Fucus 



