258 Prof. Dr. C. Mereschkovsky's Diagnoses 



Lecanora cldarona, forma albinea, Mer. 

 Mereschkovsky, Mater, p. une Monogr. d. genre Lecanora. 



Thallus determinatus vel subefFusus, crassiuseuliis vel sat crassus, 

 gramiloso-verrucosus, baud pulverulentus, lacteo-albus, colore 

 griseo vel glaucescente (ut plus minus in typo videtur) omnino 

 destitutus ; apotbecia media, circiter 1 (usque ad 1-3) millim. 

 lata, parum elevata vel subapplanata, subconferta vel contigua, 

 interdum mutuo pressione subangulosa, disco planiusculo vel 

 couvexiusculo, brunneo vel rufo-fusco (ut in forma applanata, 

 Mer.), undo, margine thallode mediocre, parum vel vix discura 

 superante, distincte minuteque granulato-crenulato. 



Spec. orig. (1) in lierb. Conservat. botan. Genevse (vide 

 Tabulas Lecanorce chlarona\ (2) in lierb. Brit. Mus. 

 Lugano (Helvetia italica). 



Forma applanata, Mer. 



Mereschkovsky, l. c 



Tballus indeterminatus, sat tenuis, crassitudine ut in forma typica, 

 ambitu in hypothallo albo evanescens, granulosus, albidus (simul 

 ut in forma albinea), in herbario tempore sordide lutescens ; 

 apothecia mediocria, vulgo 0"8-l-3 (usque ad 1*5) millim. lata, 

 orbicularia, numerosissima, conferta, sed baud compressa, nee 

 angulosa, plana et arete adnata, quasi adpressa, una altera baud 

 snperantes, disco piano (statu juvenili concaviusculo), rufo-fusco 

 vel laete brunneolo (couleur de cuir), nudo ; margine mediocri 

 vel subtenui (ut in forma typica), disco parum superante, albo 

 (tballo concolore), tenuiter, distincte regulariterque granulato- 

 crenulato (valdedistinctior quam in Licb. ticin. exs. no. 14 et 15). 



Spec. orig. (1) in herb. Conservat. botan. Genevse (vide 

 Tabulas Lecanorce chlarouce), (2) in herb. Brit. Mus. 



Forma griseoluj Mer. 



Mereschkevsky, I. c. 



Tballus bene evolutus, baud albus ; apotbeciis dense griseo-pruinosis, 

 disco rugoso. 



Spec. orig. in herb, meo Kazani. 

 Austria Inferior. 



Forma pallescens, Mer. 

 Mereschkovsky, I. c. 

 Tballus subevanescens, albus ; apotbeciis pallide testaceis, seepe 

 subdifibrmibus, margine tenui, albo, miuute granulato-crenulato. 



