PARHELIA. 61 



not a member of the brown series, but a blackened form of a 

 member of the glaucesceut series ; and there is no question with 

 which species of the latter it shall .in that case be associable, as 

 an extremely recedent, exclusively alpine condition. 



10. P. pertusa (Schrank) Schser, ; thallus closely attached 

 to the substrate, inflated, membranaceous, glaucous - white ; 

 beneath black, smooth, destitute of fibrils ; lobes sinuately- 

 many-cleft, compaginate, here and there sparingly perforated 

 with rounded holes, and beset with conspicuous, scattered, 

 round, white soredia; apothecia (very rare, except in austral 

 regions) ' smallish, chestnut, with an entire margin. Spores in 



twos and fours, ellipsoid, ^ mic.' Schcer. Spicil. p. 457. Nyl. 



Syn.l,p.4Q2. P. terebrata, Mart. Tuck. Lich. exs. n. 16. P. 

 diatrypa, Ach. L. U. p. 493. 



Trunks, and also rocks, frequent in mountain forests, but 

 not seen fertile. White Mountains ; and also in Hampshire, 

 Mass., Tuckerman Lich. N. E. 1841. 



11. P. lophyrea, Ach.; thallus cartilagineous, cinereous- 

 glaucescent; beneath black, smooth, and, on this side only, 

 cribrose-foraminous ; lobes flattish, lacunulose, flexuous, sinu- 

 ately many-cleft, the tips cut-crenate; apothecia middling- 

 sized; disk chestnut, with a thin, sub-creuate margin. Spores 



spherical, diam, 3-4 mic. Ach. ! L. U. p. 481, & e Nyl. 



Scand. p. 104. P. cribellata, Tayl. ! New Lich. in Hook. Lond. 

 Journ. Sot., 1847, p. 164. Nyl. Syn. 1, p. 403. 



Trees on the West Coast (Menzies) Acharius Meth. 1803. 



12. P. colpodes (Ach.) Nyl. ; thallus coriaceous-membrana- 

 ceous, glaucescent, clothed beneath with a dense, spongy, dark- 

 brown, and blackening nap, and beset here and there with coarse 

 fibrils ; lobes sinuately-many-cleft, flattish, at least at the periph- 

 ery, and there at length more or less cristate-lobulate ; apothecia 

 middling to large ; disk chestnut, entire., Spores very numerous 

 in the thekes, oblong, or club-shaped, and more or less bowed, 

 -^ mic. Tuck. Lich. exs. n. 74. Nyl. Syn. I, p. 404. P. col- 

 podes, & P. cristulata, Ach. Syn. pp. 118-19. Imbricaria con- 

 vexiuscula, Michx. FL, fide Mull. 



Trunks, common throughout the larger part of the United 

 States ; but not known as yet from the Kocky Mountains, or 

 the West Coast. New England (Swarts), Ach. Prodr. 1798. 



