496 IV. Licheues, 2. discocymatii. 



datam elidunfc; alia denique reliquis magis tenuantnr, 10 

 lacinias finduutur arctiusquc eubilibus in orbem expansa 

 et quasi coniluentia adprimuntur (Lccanora adglutinata 

 FL). 3) Alia blastemata periblastcsiu phyllodem evin- 

 cuut, angustantur antem ac cohstiparitur et a margiue 

 vel sub ipsis cymatiis tentacula exserunt (Lecanora ulo- 

 ihrix Ach.), sivc dilatantur, pythmenes coerccnt, ordinem 

 concentricum feliciter quidcm, P. pulvcrulentae more per- 

 fieiunt, plerumque tamen a typo tum nisu dispergendi 

 et assurgendi tum chnaumata soreumatica a ceutro inde 

 profundendi deilectunt iisqne denique incondita, in P. 

 pityreae modnm penitus obliterautur.^) 



966. P. aleurites Ach., blastemate thallode, su- 

 pra incuso pallide-cinerascente, subtus concolore pyLli- 

 menes nigros exserente, phyllis Centralibus rugoso-pli- 

 catis coutignis, periphericis discretis planis rotundatis 

 undulatis inciso crenatis in orbem figuratum digestis, cy- 

 matiis planis scutellaribus nigro-fuscis ciuctura crenula- 

 ta incusa redimitis. — P. aleurites Ach. Uch. 484., syn. 

 208. Lobaria dijfusa Hoffm. germ. 156., Placodium dif- 

 fusum JJoffm. pl. lich. t. 65. /. 2. Lichen aleuritcs Ach. 

 pr. 117. irahlcnb. lapp. 423., succ. II. 816. Engl. bot. 

 t. 858. L. diffusus Dicks. cr. UI. t. I). /. 6. 



Ad ligna vetusta sepimentorum Abietesque grandae- 

 va* Hereyn. (Jloffm t ). 



£67. P. diffusa W*, blastemate thallode utrinqne 

 homoplacino supra nitidulo, nunc cinereo -fuscescente 

 nunc pallide-sulfureo nitidulo subtus phaeotropo pytli- 

 menibus brevibus uigricantibus arcte adhaerente, phyilis 

 linearibus complanatis adpressis laciniatis, periphericis 

 sublatescentibus obtusc-bi-trilobis subtruncatis orbiculatim 

 radiantibus, ccntralibus conniventibus saepius verrucosis, 

 vervucis plurimis in sorcumata chnaumatica centrum non- 

 nisi nbiitcrautia fatisccntibus, cymatiis centralibus discum 

 planum rubro-fuscnm ciuctura crenulata redimitum re- 

 cludentibus, scutellaribus. — Parmelia diffusa ffallr. 

 in lit. Lichen ambiguus Jl ahlcub. succ. II. blS. 



