296 Scientific Proceedings, Royal Dublin Society. 



Parasites 



alphabetically arranged, with periods of 

 duration, times of fructification, &c. 



Host Pi,ants 



in the order of frequency, with periods 

 of duration. 



I'olysiphonia atro-rubescens. 

 All the year. (" Fruit, Winter," 

 Le Jolis. ) ( " Winter and Spring, ' ' 

 Crouan). Usually on rocks at 

 limit of low tides. 



Porphyra laciniata. 

 All the year. Usually on rocks 



I'tilota plumosa. 

 Perennial. Fruit, July and August. 



llhodymenia palmata 



Biennial. Cystocarps, July and 

 August. T. ("Spring," CVoMan. 

 '■ Fruit, November to February," 

 Le Jolis.) Tetraspores, February. 



Rhodomela lycopodioides. 



Perennial. Fruit,March to June. T. 



Rhizoclonium riparium. 



January to August. T. (" Winter 

 and Spring," Crouan. "All the 

 year," Le Jolis.) 



llivularia atra. 

 All the year? Often on rocks. 

 Always submerged. 



Sphacelaria cirrhosa. 



All the year. Fruit, June and July. 



Ulothrix flacca. 



Annual. November to August. T. 

 Fruit in Winter and Spring. 

 Usually on rocks near high water. 



Polysiphonia elongata, rarely. Peren- 

 nial. 



Corallina officinalis. Perennial. 

 Callitham. arbuscula. Do. 



Himanthalia lorea. Do. 



Polysiphonia fibrillosa. Do. 



Cladophora rupestris, rarely. All the 

 year. 



Laminaria digitata. Perennial. 



Rhodomela lycopodioides, rarely. 



Perennial. 

 Polyides lumbricalis, very rarely at 



Dunbar. Perennial. 



Ahnf eldtia plicata, rarely. Perennial. 

 Lam. digitata, ,, Do. 



Fucus serratus, ,, Do. 



,, vesiculosus, ,, Do. 



Laminaria digitata. Perennial. 

 Fucus vesiculosus. Perennial. 



Corallina officinalis. Perennial. 

 Cladophora rupestris. All the year. 

 Cladostephus spongiosus. Perennial. 



Halidrys siliquosa. Perennial. 

 Cladostephus distichus. Do. 

 Polysiphonia fibrillosa. Do., rarely. 



Fucus vesiculosus. Perennial. 

 Callithamnion Rothii. Do. 

 Corallina officinalis. Do. 

 Fucus platycarpus. Do. 



