Marine Algoi of the Dunhar Coast. 283 



level, incrustiag rocks and stones ; also on exposed rocks in damp 

 places. Perennial. Fruit in Avinter. 



Family.— ]\rYRIONEMACE^. 

 MYRIONEMA, Grev. 



56. Myi'ionema vulgare, Thur. {Myrioncma strangulans, Grev.) 

 Epiphytic on Enteromorpha compressa at about half-tide level. 



Left uncovered by the tide, and exposed to the light for some hours 

 daily. Annual. Summer and autumn. Fruit in July and August. 



56a. Myrionema vulg-are, var. punctiformc (Harv.), Batters. 



Epiphytic on Porphura laciniata at about half-tide level. 

 Annual. Summer and autumn. Fruit in July and August. 



Family. —CHOKDAEIACE^. 



Tribe I. — Leathesieje. 



ELACHISTA, Duby. 



57. Elachista Areschougii, Crouan. 



Epiphytic on Himantlialla lorea. Annual. June to October. 

 Fruit in July and August. Found by Edward Batters in July 1884. 

 Kew to Britain. 



58. Elachista flaccida, Arescb. 



Epiphytic on Halklrys siliquosa, Himanthalia lorea, Fucus 

 vesiculosus, Ahnfeldtia plicata, and other Algse between tide marks. 

 Annual. June to September. Fruit in July and August. 



59. Elacliista fucicola (Valley), Fries. 



Epiphytic on Fucus serratus and Fucus vesiculosus between tide 

 marks. Earely on rocks. Common. Annual. June to September. 

 Fruit in July and August. 



60. Elachista Grevillei, Harv. iu Nat. Hist. Review, vol. iv. p. 202. 

 Epiphytic on Claclopjliora rupestris in shallow pools above half- 

 tide level. Annual. Summer and autumn. 



61. Elachista scutiilata {Eng. Bot.), Duby. 



Epiphytic on Himanthalia lorea. Annual. Summer and 

 autumn. 



LEATHESIA, Gray. 



62. Leathesia difibrmis (Linn.), Aresch. (Lcathesia tuheriforviis, Gray.) 

 On sand-covered rocks, and epiphytic on small Algte, chiefly in 



shaded places, from about half-tide level to low-water mark. Usually 

 left dry by the tide for some hours daily. Annual. May to 

 October. Usual host plants : Gorallina officinalis, Cladophora 

 rupestris, Halidrys siliquosa, Laurencia liybrida, Polysiphonia 

 nigrescens, Polysiphonia Jihrillosa, Cladophora laitevirem-, Aspero- 

 coccus echinatus. 



