314 Mr George Traill on the 



77b. Myrionema Leclancherii, Harv. 



Usually epiphytic on decaying fronds of Rhodymenia jialviata 

 and Ulva Laduca, Linn. Annual. Autumn. One specimen 

 from Rousay epiphytic on Ulva Laduca, Linn., found by Mrs 

 Traill of Woodwick about the year 1839. Identified recently by 

 Mr Batters. This is the only Orkney specimen recorded. 



Family. —CHORD ARIACE^. 



Tribe I.— Leathesie/E. 



ELACHISTA, Duby. 



78. Elachista stellaris, Aresch. 



Found in Kirkwall Bay epiphj'tic on Stilopliora Lynghya.4 by 

 Mr Pollexfen. Identified by Mr Batters. New to Orkney. 



79. Elachista fucicola (Velley), Fries. 



Ei^ipliytic on fud between tide marks. Annual. June to 

 September. Fruit in July and August. 



80. Elachista scutulata {Eng. Bot.), Duby. 



Epiphytic on Himanthalia lorea. Annual. Summer and 

 autumn. Fruit in August. 



LEATHESIA, Gray. 



81. Leathesia difformis (Linn.), Aresch. (Lcathesia tuheriformis, S. F. 



Gray.) 



On sand-covered rocks, and epiphytic on small Algse, from about 

 half-tide level to low-water mark. Usually left uncovered by the 

 tide in shaded places for several hours dail}'. Annual. May to 

 October. 



Tribe II. — Euchordarie^. 



CHORDARIA, Ag. 



82. Chordaria flagelliformis (Miill., Fl. Dan.), Ag. 



In pools between tide marks ; common. Annual. April to 

 l^ovember. Fruit in August. 



Tribe III. — Mesoglcee.^. 



MESOGLOIA, Ag. 



83. Mesogloia vermiciilaris {Bng. Bot.), Ag. 



Generally a little below low-water mark on stones and rocks ; 

 also epiphytic on Algae. Always submerged. Annual. Summer. 

 Exposed rocks, Skaill, West Mainland ; Broch of Deerness, fine. 



CASTAGNEA (Derb. et Sol.), Thuret. 



84. Castagnea virescens (Carm. ), Thur. {Mesogloia vircsceiis, Carni.) 

 Common on rocks and stones in jwols at about half-tide level ; 



very rarely epiphytic on Alg*. Always submerged. Annual. 

 Spring and summer. 



