292 Scientific Proceedings, Royal Dublin Society 



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Parasites 



alphabetically arranged, with periods of 

 duration, times of fructitication, &c. 



Host Plants 



in the order of frequency, with periods 

 of duration. 



Ectocarpus siliculosus. 



May to July. Fruit, June and July. 



Ectocarpus brachiatus. 



Annual. Fruit, June and July. T. 

 (" May, June." Le Jolis.) 



Ectocarpus fasciculatus. 

 Annual. Summer and Autumn. 



Ectocarpus secundus. 



Annual. May, September. Some- 

 times attached to shells. 



Ectocarpus littoralis. 



At all seasons. (Spring, Autumn. 

 Le Jolis.) Often on muddy 

 rocks. 



Ectocarpus tomentosus. 



April to September. T. ("Sum- 

 mer." Le Jolis and Crouan.) 



Corallina officinalis. Perennial. 



Cladophora rupestris. All the year. 



Chorda lomentaria. March to No- 

 vember. 



Chordaria flagelliformis. April to 

 November, and later. 



Halidrys siliquosa. Perennial. 



Asperococcus echinatus. April to 

 October. 



Chorda filum. April to December. 



Polysiphonia elongata. Perennial. 



Laminaria phyllitis. H. May to 

 August. 



Pol. urceolata. March to October 

 Some plants survive Winter. 



Ehodymenia palmata, rarely. Bien- 

 nial. 



Ceram. Deslongchampsii, rarely. All 

 the year. 



Myriotrichia clavaeformis. May — Aug. 



Ehodymenia palmata. Biennial. 



Laminaria saccharina. Perennial. 



Phyllitis caespitosa. March to No- 

 vember, and later. 



Fucus serratus. Perennial. 



,, vesiculosus. Do. 



Chorda lomentaria. March to N. 



vember. 

 Pol. fastigiata. Perennial. 

 Halidrys siliquosa. Do. 

 Cladophora rupestris. All the year. 

 Callitham. arbuscula. Perennial. 

 Lam. digitata. Do. 



Ulva latissima. "At all seasons." 



Harvey. 

 Conferva melagonium. Perennial. 

 Ehodymenia palmata. Biennial. 

 Polysiphonia fibrillosa. Perennial. 



Fucus vesiculosus. 



„ serratus. 

 Himanthalia lorea 



Perennial. 

 Do. 

 Do. 



