Knowles — The Maritime and Marine Lichens of Hototh. 133 



*L. sorediza Nyl. — Only seeu on the cliffs at White Water Brook. 



tL. albocoerulescens Aoh. — On shady rocks, west end of Broad Strand; 

 abundant. 



tL. confluens Ach. — On rocks, north coast; frequent. 

 L. rivulosa Ach. — On rocks here and there on south and soutli-west coasts ; 

 frequent. On the east and north coasts it grows with Lecanora glaucoma 

 and RMzocnrpon geographicum. 



fL. griseoatra Schaer. — On the cliffs, Hippy Hole. 



*L. imponens Leight. — On Lecanora polytropa, east coast. The only other 

 localities in which this species has been found are near Fishguard in 

 Wales. 

 Biatorina coeruleonigricans A. L. Sm. — On calcareous soil, Q-lenaveena ; 

 very common on the lower part of the earth-banks with Bermalocarpon 

 hepaticiim, Bilimhia aromatica, &c. 



*B. synothea Koerb. — On soil. Old Boat-house, associated with Cladonia 

 cervicornis, and in similar situations at Earlscliffe. This species has 

 not hitherto been noted as growing on the ground, and the Howth 

 specimens are interesting on this account. The spores are typical, 

 measuring 10-12/x x S-ifi, and the epithecium gives the characteristic 

 violet colour when treated with K. The spermogones are numerous, 

 measuring 4-5ju x 2/z. The thallus of the Howth specimens is usually 



* subsp. subnigrata A. L. Sm. — On schistose rocks near the Needles; 



scarce. Distinguished from the species chiefly by the stouter 



spores. 



fB. lenticularis Koerb. — Plentiful all round the coast. On the Broad Strand 



it grows with Placodium lohulcttum on rocks where it is wetted by the 



sea-water at high tide. 



f. nigricans Arnold. — Occasionally with the species. 

 fB. chalybeia Mudd. — On quartzite rocks near the Needles, associated with 



BiieUia canescens ; frequent, 

 t subsp. chloroscotina A. L. Sm.— On slates and schists, in shade. Broad 



Strand, and at High Room Bed ; rare. 

 *B. contristans A. L. Sm. — The specimens which I have referred to this 

 species were gathered at Earlscliffe, where they were growing on the 

 ground, in a dark shady situation, amongst mosses, and associated with 

 Bacidia imihrina. The apothecia are frequently conglomerate ; but the 

 size of the spores and the other characters agree with the description in 

 the " Monograph of British Lichens." The only previous record in the 

 British Isles is from the summit of Ben Lawers, so that the Howth 



