218 PROCEEDINGS OF THE AMERICAN ACADEMY 



2. P. perforata, Ach. Th. membranaceous, smooth, greenish-glau- 

 cescent ; on the under side black, with dark fibres ; lobes rounded, as- 

 cendant, subcrenate, ciliate ; apoth. large, rufous, elevated, infundibu- 

 liform ; disk perforate, at length explanate, margin very entire. Fr. 

 Lichenogr. p. 58. 



Trees, particularly on the coast, luxuriant and fertile. Also on 

 stones, &c., in sterile states. Pennsylvania and Virginia (from Bartram 

 and Mitchell), DHL, the original stations of the Lichen. New Eng- 

 land. New York, Torrey. Northwest Coast, Menzies (Herb. Smith!). 



3. P. perlata, Ach. Th. submembranaceous, suborbicular, green- 

 ish-glaucous ; on the under side blackish-fuscous, scarcely fibrillose ; 

 lobes rounded, plane, not ciliate ; apoth. elevated, dark red, cyathi- 

 form, at length explanate, margin thin, entire. Fr. Lichenogr. p. 59. 

 — /5. olivetoruni, Ach. ; margins of the lobes elevated, ci'isped, white- 

 pulverulent. Acli. Syn. p. 198. 



Trunks and rocks in mountainous districts, fertile ; and common also 

 in sterile forms ; New England. New York, Halsey. 



4. P. scortea, Ach. Th. subcoriaceous, orbicular, smooth, glaucous- 

 white ; on the under side black, hispid-fibrillose ; lobes longish, sinu- 

 ate-crenate, incised ; apoth. rufous-fuscous, margin somewhat entire. 

 Ach. Sijn. p. 197. 



Stones and trunks, fertile ; New England. New York, Halsey. 

 Pennsylvania, Muhl. Less common than the next, with which Fries 

 unites it. 



5. P. iiliacea, Ach. Th. membranaceous, orbicular, smoothish, 

 glaucous-cinerascent ; on the under side blackish-fuscous, with black 

 fibres ; lobes sinuate-lacinlate, the external ones rounded, crenate ; 

 apoth. subfuscous, margin very entire. Ach. Syn. p. 199. 



Trunks, fertile, very common ; New England. New York, Halsey. 

 Pennsylvania, Muhl. Nova Scotia, Menzies ! 



6. P. Borreri, Turn. Th. cartilagineous-merabranaceous, orbicu- 

 lar, smoothish, glaucous-cinerascent (with round, marginate soredia) ; 

 on the under side fuscescent, fuscous-fibrlllose ; lacinise rounded at the 

 apices, naked ; apoth. chestnut, margin inflexed, entire. Fr. Lichen- 

 ogr. p. 60. — /?. rudecta, Tuckerm. ; soredia immarginate ; the whole 

 thallus beset with isidioid granules and branchlets. P. rudecta, Ach. ! 

 Syn. p. 197. 



