OF ARTS AND SCIENCES. 255 



23. B. quernea, Fr. Cr. deliquescent, granulose-farinose, fuscescent- 

 ochroleucous ; hypoth. black ; apoth. immersed, convex, brown, at 

 length immarginate. Fr. Lichenogr. p. 279. Lecidea^ Ach. 



Trunks ; New England. 



24. B. lucida, Fr. Cr. granulate, greenish-yellow, at length deli- 

 quescent and ochroleucous ; hypoth. white ; apoth. (minute), convex, 

 pale yellow, often excluding the paler margin. Fr. Lichenogr. p. 279. 

 Lecidea, Ach. 



Stones and decaying wood. Arctic America, Rich. 



25. B. aurantiaca, Fr. Cr. cartilagineous, uneven, somewhat gran- 

 ulate, lutescent ; innate in a black hypothallus ; apoth. somewhat ele- 

 vated on a thalline stratum which constitutes a crenulate, evanescent, 

 spurious margin, disk dark-orange (and fuscescent), with a thin proper 

 margin. Parmelia, Fr.! Lichenogr. p. 165. Lecidea, Ach. Borr.in 

 Hook. Br. Fl. 2, p. 186. Lecanora salicina, Ach. 



Trunks, dead wood, and rocks ; New England. New York, Hahey. 

 Pennsylvania, Muhl. Arctic America, Rich. 



26. B. fusco-lutea, Hook, (sub Lecid.). Cr. thin, effuse, smooth, 

 somewhat granulose, whitish; apoth. somewhat elevated, plane, yel- 

 lowish, at length rufous-fuscous, pruinose, with a thin margin. Lecidea, 

 Hook, in Rich. I. c. Lichen fusco-luteus, Dicks. E. Bot. t. 1007. 



Upon mosses ; Arctic America, Rich. Fries suspects this to be a 

 state of B. ferruginea. It does not seem to be the Lecidea fusco-lutea, 

 K, of Ach. Syn. 



XVI. LECIDEA, Ach., Fr. 



Apolhecia margined at first by a very black, carbonaceous, proper 

 exciple, becoming scutelliform or hemispherical, solid. Disk at first 

 punctiform-impressed, always open, oftener horny, and placed upon a 

 carbonaceous stratum. Thallus horizontal, arising from a hypothallus, 

 somewhat crustaceous, effigurate, or uniform. Apothecia very black 

 from the first, the margin never, and the disk rarely, otherwise col- 

 ored. Fr. 



Sect. I. Thallus efiigurate at the circumference, or wholly rugose- 

 plicate. 



1. L. Candida, Ach. Crust rugose-plicate, candicant, becoming at 

 length white-farinose, lobed at the circumference ; hypothallus black ; 



