Knowlks— r/?e Maritime and Marine Lichens of Howth. 131 



L. (0.) pallescens Nyl. — On Blackthorns, Earlscliffe ; rare. 

 Lecanora (Aspicilia) calearea Somm. — On the limestone ; rare. 



fLecanora (Acarospora) fuscata Nyl. — On grits and shales in sunny situations; 

 frequent. 



tL. (A.) rufescens Nyl. — On grits and quartzites, Broad Strand ; frequent. 



fL. (A.) smaragdula Nyl. — Very common on dry rocks in sunny situations all 

 round the coast, associated with Buellia sjjp. and L. simplex, f . strepsodina. 



fL. (A.) Heppii Nyl. — On grits, Hippy Hole, associated with Rhizocarpon 

 peiraeum ; rare. 

 L. (A.) pruinosa Nyl. — On walls, Sutton ; rare. 



fl. (A.) simplex Nyl., f. strepsodina Ach. — On loose stones at the base of 

 eartli-banks, and on schistose rocks all round the coast ; very common. 



*ACAI10SP0EA BENEDARENSIS^ Nov. Sp.'— Thallus dark brown, thick, 

 glebulose-squamulose ; squamules discrete or sometimes confluent, pale 

 beneath, 1-7 mm. wide and about \-l mm. thick, K- CaCl-; apothecia at 

 first completely immersed, innate, concave, concolorous with the thallus, 

 1 or more in each squamule, reddish-brown when moist, margin thick, 

 entire, persistent; paraphyses slender, conglutinate, sparingly branched, 

 yellow-brown at the apices ; hypothecium sordid grumous ; ascus clavate, 

 80-100;u X 15-20 (U, myriospored ; spores, 3-4-6/^ x l-2-5(u; spermogones 

 numerous; spermatia 2-5 /x x l-l'5;u. 



When treated with iodine the first part of the apothecium to take the 

 stain is the hypothecium, which at once turns deep indigo-blue, passing 

 ofE into sordid green later ; the hymenial gelatine gradually takes on a 

 rich clear wine-red colour. 



Habitat — On dry clayey soil and on disintegrating fine shales in 

 sheltered sunny situations on the earth-banks at Broad Strand. 



Sub-tribe PERTUSARIEI. 



Pertusaria dealbata Nyl. f. corallina Cromb. — Broad Strand ; rare. 

 P. ceuthocarpa Turn, and Borr. — East coast ; rare and infertile. 

 P. concreta Nyl. On schistose rocks chiefly on the east coast, associated with 

 Lecanora glaucoma and Rhizocarpon geographicum; not common in our area, 

 f. Westringii Nyl. — On the cliffs near the Needles ; rare. 



1 Thallus eflfusus glebuloso-squamulosus, sijuamuli rimoso-discreti vel confluentes, castaneo- 

 nigii, subtus pallidiores, 1—7 mm. lati, circa J ad 1 mm. alti ; apolhecia primo immersa, semper 

 urceolata, disco piano, margine crasso, prominente, paraphysibus gracilibus, parce ramosis, sursum 

 flavo-brunis, conglutinatis ; bypothecio pallido-griseo, grumoso ; ascus clavatus, SO— lOO/i longus, 

 15-20^ latus ; sporis minutissimis 3-4-5^ loiigis, 1-2-5^ latis; hypotbecium iodo Tiolascens, dein 

 sordido-oUvaceum ; bymeniura pulcbre vino-rubescens. Ad terras argillaceas. Earlscliffe. 



^ From Ben Edar, the Celtic name for Howtb. 



