PHTSCIA. 77 



less hispid, at least below, the reddish-brown, blackening, naked 

 disk bordered by an entire margin. Spores bilocular, ^^ mic. 



Spermatia oblong. Th. Fr. Scand. p. 142. Tuckerm. Obs. 



Lich. 1. c. p. 399, max. p. Parmelia, Fr. L. E. p. 84, max. p- 

 Tuck. exs. n. 87. Schcer. Spicil. p. 441, max. p. 



* endochrysea, Nyl. ; thallus more or less saffron - coloured 



within. Var. erythrocardia, Tuckerm. 1. c. Parmelia endo- 



coccina, Koerb. Parerg. p. 36. 



Trees, dead wood, and rocks. Pennsylvania, Muhlenberg 

 Catal. 1818, and northward to Arctic America, Richardson-, 

 westward to the Pacific coast, Bolander; and southward to 



Louisiana, Hale, and Texas, Wright. A very variable lichen, 



recognizable by the coloration (though this may vary even to 

 glaucescent as to thallus and red as to apothecia in forms of the 

 v. chloantha, Auct.) by the blackening, abundant fibrils, and 

 especially by the occurrence of these more or less on the exciple, 

 which is seldom quite naked, with us, and finally bristly all over. 

 This peculiar exhibition of fibrils characterizes probably all the 

 best conditions of P. obscura, and must be taken therefore for 

 typical. The under side is not merely black-fibrillose beneath, 

 as commonly described, but black, both in European and North 

 American specimens, though doubtless varying in this. 



9(b). P. setosa (Ach.) Nyl.; thallus much as in the imme- 

 diately preceding but larger, and whitish-glaucescent becoming 

 glaucous-cinerascent, the wider, linear lobes fringed by and 

 cushioned on dense black fibrils. Spores rather larger than in 

 the preceding, ^^ mic., but reaching ffi mic. in a specimen from 



Japan. Nyl. Syn. 1, p. 429. Parmelia, Ach. Syn. p. 203. P. 



atricapilla, Tayl. ! New Lich. I. c. p. 162. 



Rocks upon mosses, and trunks. Pennsylvania, Muhlenberg 

 Catal. 1818. New England and New York, Tuckerman. Ohio, 



Lesquereux. New Mexico, Fendler. Mexico, Nylander. The 



most conspicuous member of the commonly humble obscura- 

 stock ; and, beside the lichenographers above-named who have 

 taken it for a distinct species, Nylander L c. cites also Schserer, 

 and Montagne ; and yet, except in size and general luxuriance, 

 the lichen differs in no respect from the preceding. 



10. P. adglutinata (Floerk.) Nyl. ; thallus small, membra- 

 naceous, closely adnate or as it were glued to the substrate, from 



