332 Dr. W. Nylander on new British Lichens^ 



4. Lecidea atrofuscescens, Nyl, 



Thallus cinereo-uigricans vel fusco-nigrescens, deplanatus, areo- 

 lato-difFractus^subopacus; hypothallus niger hinc inde visibilis ; 

 apothecia nigra, adnata, plana (demum convexiuscula), mar- 

 ginata, mediocria (latit. 0*9-1 "2 millim.), ssepe subangulosa, 

 intus subincoloria j sporse 8, incolores, ellipsoidese, long. 

 0-018-0-020 millim., crass. O-009-O'Oll millim.; epitheciura 

 fuscescens; paraphyses graciles, tenerse, subirregulares; hypo- 

 thecium incolor. Gelatina hymenea iodo cserulescens, dein 

 (pro parte saltem) vinose rubescens. 



Ad saxa micaceo-schistosa in Ben Lawers (Mr. I. Carroll). 

 Facie inter L» fusco-atram et tenehrosam quasi media, sporis 



majoribus inter species subsimiles mox dignota (praeter alias 



notas). 



5. Lecidea umbonella, Nyl. 



Tballus albidus vel pallidus, sat tenuis, determinatus (maculatim 

 vel insulatim crescens), rimoso-diffractus; apothecia nigra, 

 parva (latit. fere 0*5 millim.), innata, marginata, saepius sub- 

 gyrosa vel centro umbonata; sporae 8, incolores, cllipsoidcae, 

 long. 0-011-0-014 millim., crass. 0006-0'008 millim.; epi- 

 thecium subincolor; paraphyses mediocres; hypothecium fus- 

 cum vel fuscescens (umbo et perithecium fusco-nigricantia in 

 lamina tenui). Gelatina hymenea iodo bene cserulescens. 



Ad saxa micaceo-schistosa in Benmore (Admiral Jones). 

 Prope L. gyrizantem locum habeat. 



Spermatia cylindrica, recta, long. 0'006-0'007 millim., crass, 

 vix O'OOl millim. in L. umbonella. 



6. Lecidea succedens, Nyl. 



Thallus albidus, tenuis, granulato-insequalis vel subareolatus ; 

 apothecia fusco-nigra, fere mediocria, marginata, intus inco- 

 loria; sporae 8, nigrescentes, ellipsoidese (pariete tenui), sim- 

 plices aut l-septatse, long.0'011-0*014millim., crass. 0*0045- 

 0*0055 millim.; paraphyses mediocres, articulatse, apice in- 

 crassato (crass, fere 0*0045 millim.), fusco vel fuscescente; 

 hypothecium fuscum (vel rubricose fuscum). Gelatina hy- 

 menea iodo cserulescens, dein vinose rubens. 



Supra saxa micaceo-schistosa in Ben Lawers (AdmiralJones). 

 Comparetur L. secedens Nyl. in ' Flora,' 1865, p. 6, arete 

 affinis. Locus system aticus prope L. nigritulam. 



7. Lecidea segregans^ Nyl. 



Thallus albidus vel albido-cinerascens, verrucoso-granulosus, 

 granulis variis convexulis, plus minus segregatis (alibi verru* 



