OF ARTS AND SCIENCES. 221 



15. P. Fahlunensis, Ach. Th. subcartilagineous, smoothish, from 

 dark-olive becoming blackish ; on the under side paler, subfibrillose ; 

 lacinise digitate-multifid, somewhat plane, subcanaliculate ; apoth. dark- 

 fuscous, crenulate. Fr. Lichenogr. p. 66. — /5. sciasfra, Fr. ; smaller, 

 orbicular ; apoth. subentire. Fr. Lichenogr. p. 61. Parmelia, Ach. 



Alpine and subalpine rocks, and occurring also at lower elevations 

 in mountainous districts. White Mountains ; Chin of Mansfield, and 

 other of the Green IMountains; fertile. Northward to Newfoundland, 

 Pylaie, and Arctic America, Rich. — ^, Greenland, Dill. 



16. P. stygia, Ach. Th. subcartilagineous, shining, from oliva- 

 ceous-fuscous becoming black ; very black on the under side and ob- 

 soletely fibrillose ; lacinia? palmate-multifid, sublinear, convex, recurved 

 at the apices ; apoth. fuscous-black, crenate. Fr. Lichenogr. p. 67. — 

 /S. lanata, Mey. ; laciniae setaceous, filiform, terete, intricate, fuscous- 

 nigrescent; apoth. subgranulate-marginate. Mey. Entwick. der Flecht. 

 p. 231. Fr. I. c. p. 68. Cornicularia lanata^ Ach. Syn. p. 302. 



Alpine and subalpine rocks. White Mountains and the higher Green 

 Mountains. Northward to Newfoundland, Pylaie, and Arctic Amer- 

 ica, R. Br. — ,5, White Mountains, infertile. Northward to Arctic 

 America, Hook. Melville Island, R. Br. 



Series 3. O chr oleu c cb ., Fr. 



17. P. caperata, Ach. Th. submembranaceous, orbicular, rugose 

 (or granulose-pulverulent), ochroleucous ; on the under side blackish 

 and sparingly fibrillose ; lobes sinuate-laciniate, rounded, somewhat 

 entire at the apices ; apoth. fuscous-red, margin tumid-incurved, ru- 

 gose-crenate. Fr. Lichenogr. p. 69. 



Trunks and stones, not commonly fertile ; New England. New 

 York, Torrey. Pennsylvania, Muhl. Westward to Illinois, Russell ! 

 North to Arctic America, Rich, 



18. P. conspersa, Ach. Th. submembranaceous, smoothish, pol- 

 ished (oftener black-punctate), greenish-straw-colored ; fuscous and 

 black-fibrillose beneath ; lacinise variously flexuous, somewhat plane at 

 the circumference, sinuate ; apoth. dark-chestnut, margin subentire. 

 Fr. Lichenogr. p. 69. — ^. stenophylla, Ach. ; laciniae elongated, lin- 

 ear, pinnatifid, imbricate-complicate. Ach. Syn. p. 209. 



Rocks and stones, commonly remarkable for its veiy numerous 

 apothecia ; New England. New York, Torrey. Pennsylvania, Muhl. 

 North to Arctic America, Rich. Degenerate on rails, &;c. 



