130 Scientific Proceedings^ Royal Dublin Society. 



Lecanora (Lecania) erysibe Nyl. — Here and there along the Broad Strand 

 on rocks about high-water mark. 



*L. (L.) spodophaeiza Nyl. — Bottle Quay. On rocks about high-water mark, 

 associated with Placodium murorum and Verrticaria maura. Crombie 

 describes the spores of this species as simple, or often spuriously one- 

 septate. In the Howth specimens the spores seem to be almost constantly 

 one-septate. The white fimbriate circumference and the granular nature 

 of the thallus and the larger spores separate it from L.prosechoides, which 

 grows in the same habitat. The only previous records are from the 

 Island of Jersey. 



*L. (L.) actaea Nyl. — Only seen on the quartzites at Red Rocks ; rare. The 

 specimens from this locality agree very well with Larbalastier's from 

 St. Aubin's Fort, Jersey, in the British Museum Herbarium. The only 

 previous records are from the Channel Islands. 



*LECANIA ATRYNIOIDES Nov. Sp.'— Thallus greyish, rimoso-diffract, thin, 

 effuse ; hypothallus dark ; apotliecia dark reddish-brown, crowded and 

 often angulose |-lmm in diameter, margined when young, becoming 

 convex with age ; margin thin, whitish, entire or slightly sub-crenulate 

 and sub-persistent; paraphyses sub-discrete, jointed, clavate and blackish- 

 brown at the apices ; hypothecium colourless ; spores 8 in the ascus 

 colourless, ellipsoid, 1-septate, and occasionally constricted at the septum, 

 sometimes slightly curved, 10 - 14(U x 4 - 6yu; hymenial gelatine, deep blue, 

 then violet with iodine. Spermogoues with slender arcuate spermatia, 

 which are borne on the tips of simple sterigmata. 



Habitat. — Schistose rocks about high spring tide-level, Red Rocks 

 and Broad Strand. This lichen has a general resemblance to Lecanora 

 atrynea, and grows in similar situations. In some of its characteristics 

 it agrees with Lecaniella arenaria (Anzi) Jatta, " Flora Italica," p. 400. 

 I have not been able to see a specimen of this lichen, but as the Howth 

 plant differs from Jatta's description in having larger and sub- 

 persistently margined apothecia, more discrete paraphyses, and broader 

 spores, I have, after some hesitation, described it as a new species. 

 Lecanora (Ochrolechia) tartarea Ach. — Shady rocks. White Water Brook ; 



rare. 

 L. (0.) parella Ach. — Chiefly on the south and south-west coasts ; widespread 

 but nowhere abundant. 



' Thallus cinerascens, tenuis rimosus vel evanescens, inegulariler effiisus ; apothecia aggregata 

 prominula j-l mm. diam., planiuscula dein convexa ; margine thallino pallido, tenui, sub-peisis- 

 teute; paraphysibus subdiscretis, incondite, articulosis, clavis, fuscis ad apices; sporae octonae, 

 ellipticae, uniseptatae, quandoque inourvae, 10 - H/i x 4 - 6(H. Ad saxa silioeo-arinarea circum 

 locos aestuum maximorum. Sutton. 



