Clare Island Survey — Marine Algae. 15 127 



rare ; the oogonia appear to develop normally. The largest specimens of 

 var. balticv.s noted were found on a little piece of wet marsh at Leenane 

 (growing here on the flat as well as the vertical banks) — a fact which gives 

 support to the view that soft ground and a large amount of moisture favour 

 its development. 



From the above it will be seen that the var. balticus of Clew Bay 

 approaches very closely to the smallest forms of var. volubilis as described by 

 Baker. At Mersea Island, however, receptacles are only found on the large 

 plants ; and the fronds are always much twisted. At Blakeney small plants 

 fruit ; but the receptacles are much larger than in the Irish specimens. In 

 both these localities there is much mud ; and the plants are free, or more or 

 less imbedded. In Clew Bay the substratum consists of firm peat, and mud 

 is absent. 



Var. muscoides, var. nov., 1 Plate VI, "figs. 1 and 2. — Plants very short, 

 fastigiately branched, densely crowded together, 5-6 em. long. Branches 

 cylindrical or compressed, 1-3 mm. wide, not twisted, with marginal 

 eryptostomata. Beeeptacles very scarce, minute, 2-4 mm. diam., dioecious, 

 paraphyses not projecting. « 



Habitat. — On firm peat, near extreme high-water mark. 



With some reluctance I describe this Fucus as a new variety of 

 F. ccsiculosus. It approaches in form some of the Baltic filiform varieties of 

 this species ; but it differs in its peculiar habitat, and appears to be worthy of 

 a special name. At the same time, though the evidence points to its being a 

 variety of F. vesiculosus, the fact is not proved. By giving it pro tern, specific 

 rank, complications in the future are less liable to occur; but this would 

 necessitate the record of an additional new species in the list of novelties ; 

 whereas the plant is almost certainly merely a remarkable variety of an 

 already known plant. 



As previously stated, var. muscoides is connected with the Clew Bay form 

 of var. balticus, of which it may be regarded as a very dwarf upright-growing 

 form with filiform branches. The plants are packed very closely together, 

 and form a dense mossy carpet, a feature which serves to distinguish the 

 present variety from the filiform plants found in the Baltic. In a general 

 way, the more closely packed the plants are, the smaller and more terete the 

 fronds. The eryptostomata are conspicuous, and are, of necessity, marginal. 

 The fastigiate branching is characteristic ; but the branches are often very 

 irregularly produced, and a crop of lateral proliferations is not infrequent. 



1 Frondes perpusillae, dense caespitosae, filiformae vel eompressae, 5-6 cm. longae, 1-3 mm. latae, 

 eryptostomatfDus conspieuis, receptaculis rarissimis, minutis, ovoideis 2-4 mm. latis. Ad terram 

 turf oaam. 



