250 PROCEEDINGS OF THE AMEKICAN ACADEMY 



white ; apothecia marginal, adnate, somewhat immarginate, blackish, 

 white within. Fr. Lichenogr. p. 252. Lecidea, Ach. Syn. p. 52. 



On the earth, especially in alpine digtricts. Arctic America, Rich. 

 Pennsylvania, Muhl. 



2. B. gloMfera, Fr. Th. squamose, imbricate, greenish-chestnut, 

 somewhat shining ; scales reniform, rugose, lobate ; apoth. elevated, 

 globose, somewhat immarginate, from rufous becoming black, whitish 

 within. Fr. Lichenogr. p. 255. Lecidea, Ach. Syn. p. 51. Icon, 

 Laur. in Sturm's Fl. t. 26. 



Clefts and depressions of rocks. North America, Ach. Pennsylva- 

 nia, Muhl. New York, Halsey. 



3. B. rufo-nigra, Tuckerm. Th. squamose, imbricate, from pale ru- 

 fous becoming blackish ; scales irregularly suborbiculate, ascending, 

 crenate-lobate ; apoth. adnate, plane, obtusely margined, atrorufous, at 

 length convex, black. Placodiuni sp. nov. Tuckerm. Lich. N. E. I. c. 

 1838. 



Rocks ; near Boston. Scales of the thallus small, obscure to the 

 naked eye. ' 



4. B. airo-rufa, Fr. Th. crustaceous, smoothish, adnate, at first con- 

 tiguous, becoming at length areolate, cinereous-fuscescent ; black be- 

 neath ; at the circumference foliaceous-lobate ; apoth. applanate-adnate, 

 rufous-fuscous, whitish within. Fr. Lichenogr. p. 255. Lecidea, Ach. 

 Lichenogr. p. 200. 



On the earth in alpine districts. White Mountains. 



**- 



'^' Apothecia stipitate, margin at length revolute. 



5. B. placophylla, Fr. Th. subcrustaceous, orbicular, corrugated, 

 glaucous-virescent, at the circumference foliaceous, lobes rounded, and 

 crenate ; white beneath ; apoth. stipitate, pileiform, rufous-fuscous ; 

 stipes thick, compressed, longitudinally rugulose. Fr. Lichenogr. p. 

 257. BcBomyces, Ach. Meth. p. 323, ^ Icon, t. 7, /. 4. Lich. Univ. 

 p. 574. 



On sandy, sterile earth ; slides, and banks of streams, in the White 

 Mountains. 



6. B. Byssoides, Fr. Th. crustaceous, effuse, granulosa, greenish- 

 glaucous, squamulose at the circumference ; hypoth. fibrillose, white ; 

 apoth. substipitate, pileiform, from flesh-colored becoming fuscous ; 



