Clare Island Survey — Marine Algae. 



15 19 



The following table presents the associations and other communities 

 composing the rocky-shore formation in the Clare Island area:— 



A. Exposed coast scries. 



(a) Littoral Her/ion. 



Hildenbrandtia-Verrucaria. 



Prasiola. 



Enteromorpha intestinalis. 



Fucaceae. 



Lichina. 



Porphyra. 



Bangia-Urospora- Ulothrix. 



Ithodymenia. 



Laurencia-Gigartina. 



Callithamnion arbuscula. 



Nemahon. 



Himanthalia. 



Corallina-Lithothamnium. 



Pool vegetation. 



Cave vegetation. 



(b) Sub-littoral region. 



Laminaria. 

 Encrusting algae. 



B. Sheltered coast series. 



(a) Littoral Region. 



Hildenbrandtia-Verrucaria. 



Fucaceae. 



Lichina. 



Porphyra. 



Laurencia-Gigartina. 



Corallina-Lithothamnium. 



Corallina-Cladostephus. 



Ehodochorton floridulum. 



Sand-pool vegetation. 



Cave vegetation. 



(b) Sub-littoral region. 



Laminaria. 

 Encrusting algae. 

 Eruticulose Lithothamnium. 



A. Exposed Coast Series. 



(a) Littoral Region. 



Hildenbrandtia-Verrucaria Association. 



The description of this algal and lichen community is somewhat brief, 

 owing to the difficulty of distinguishing the species in situ, and the labour 

 involved both in collecting and naming material. Hildenbrandtia prototypus 

 and the marine species of Verrucaria are usually taken together as forming 

 one association, and some writers include other plants such as Rividaria atra 

 and Calothrix scopidorum. It is, however, a question whether it would not be 

 advisable to include in the association all the littoral encrusting species that 

 are soft and not calcareous (see note on sheltered form of association, p. 51). 



Hildenbrandtia and Verrucaria resemble each other precisely in growth- 

 form ; and they are often found growing together covering an area of several 



C2 



