450 Mr Eattray on the Distribution of 



tiforme and 31. strangulans) are not unfrequent from Incli- 

 keith eastward, but the finest forms occur from Dunbar on 

 the south and Kincraig on the north seawards. Corallines 

 are very common (e.g., Corallina officinalis). 



Although some of the most delicate species (e.g., Calli- 

 thamnion Jloridulum, Ceramium diaphanum^ &c.) are here 

 found in abundant association with more robust forms, 

 many of the most beautiful species among the Floridece are 

 especially found in the previous deeper areas ; while, on 

 the other hand, the Chlorophycefe are now beginning to 

 occur in far greater prominence. TJlvacecc {Monostroma latis- 

 simum, JJlva linza, and U. laciuca) are common. Porphyra 

 vulgaris is found from Cramond eastwards ; Confervce are 

 frequent. Gladoplwrce {C. arcta, C. rupestris, G. lanosa, G. 

 Imtevirens, G. glaucescens) are abundant in many parts, but 

 esj)ecially so in rock pools, where the water is free from 

 mud, and well towards the sea. The Enter omorphce are here 

 more common, especially E. compressa and E. erecta. 



On the May Island (seaward side) there is a very copious 

 development of Ghylocladia articulata in this zone beneath 

 a ledge of rock, in a somewhat dark secluded situation, and 

 associated with many sponges and zoophytes. 



The uppermost or Enteromorplia area is especially charac- 

 terised throughout the entire estuary by the presence of 

 Ghlorophijcece. Among these the Enteromorphce are espe- 

 cially prominent in many parts. The circumstance, more- 

 over, that E. intestinalis can survive in pools that are quite 

 above the level of tidal influence, and which can only 

 procure their saline constituents from spray during storms, 

 seems to mark this genus as worthy to give a name to the 

 belt. Enteromorpha intestinalis is also very common in 

 many parts throughout the belt from Inchcolm eastwards, 

 and is usually found in places where fresh water is entering 

 the estuary. It thus forms a well-marked transition to the 

 truly fresh water forms that are often found in its imme- 

 diate proximity. E, compressa is very common all over 

 the estuary, especially from Queensferry to the east, in this 

 belt. It is less sensitive to the influence of fresh water 

 than E. intestinalis, yet is often found associated with the 

 latter where fresh water is dropping down from cliffs or 

 high rocks. In such situations, moreover, it is very com- 



