40 THE SIAEINE ALO.E OF aUEBNSEY 



All along the west coast, where there is less exposure, the rocks at 

 low tide are thickly covered with H. palmata var, marginrfera. The 

 plants are about 6 inches or so in length, reddish yellow in colour, 

 much thinner in texture, and thickly fringed along their edged with 

 long narrow processes. Occasional plants of J^. serratus mingle here 

 and there among the growth. With the moderately sheltered condi- 

 tions of the east coast there is again a widely spread shaggy develop- 

 ment over rocks of the same level, chiefly of f. tj/pica, with fronds 

 4-0 inches in length. Here and there are specimens of vars. sarniensis 

 and marqinifera. Among the undergrowths are Griffithsia setacea, 

 G. corallina, Oallithamnion tetricum, and PtiJota sericea. 



With increased shelter, as at Bordeaux and Petit Bot, etc., the 

 same conspicuous and heavy growths are prevalent over the rocks at 

 half-tide level, low^er down the plants grow to enormous size, and are 

 bright in colour and thin in texture. The epiphytes are Phloeospora 

 Lrac/u'afa, Polysiphonia Brodicei, Ectocorpus granulosus. 



Laureucia Zone, 



L. pinnatijida occupies a similar f)Osition along the shore to that 

 of Rhodymenia, but appears mostly as an undergrowth. Scanty, 

 greenish procumbent patches creep over old Lithotliamuion Lenor- 

 niandi and L. incrustans aiahoni half tide, where the perennial plants 

 of Laurencia were seen sending up new shoots: their colour deepens 

 towards the Sub-littoral and the growth increases in luxuriance. The 

 best development was observed in moderate shelter^ 



CI 1 071 dr us Zone. 



C. crispus is fairl}^ ubicpiitous from the Mid-littoral down into 

 the Sub-littoral regions. It is scanty in extreme exposure, but fairly 

 abundant along the semi-exposed west coast, where masses of the 

 deep water form are constantly thrown up : with greater shelter tlse 

 zone is enci'oached on by other sjjeeies — viz. Gigartina stellatay 

 Gracilarin confervoides, Ogstocloninm pwrpureicm, Laurencia dasy- 

 pJiylla, etc. Of these, Gigartina sfellata is the most abundant ; it 

 grows in patches here and there along the coast or inhabits rock-jjools 

 and flourishes best with moderate conditions of climate. 



Zone of Soft Encrusting Algce. 



In sheltered districts Ilildenhrandtia sp. grows over rocks and 

 stones under the belt of Eucus spiralis, and descends occasionally to 

 the lower littoral ; at about half tide Eetrospongium Bei^keleyi and 

 Codium adhcprens form scattered patches over bare rocks down to low- 

 tide level, as at L'^Ancresse Bay and Saint's Bay. Malfsia spp. and 

 Feyssonnelia sp. are characteristic of greater exposure and have a 

 wide range over the shore from above half tide down into the Sub- 

 littoral, chiefly on small stones and limpet-shells under the shelter of 

 the larger algse. Eetrocelis crnenta occurs very sparsely, irrespective 

 of climatic conditions, at about the level of low-water mark. 



