PLACODITJM. 177 



perhaps darker ; apothecia small, crowded, adnate, now distinctly 

 lecanorine and now of biatoriue aspect ; the flattish, finally tumid 

 disk brownish-orange, fulvous, or rust-coloured, the entire bor- 

 der often darker. Spores linear-oblong or cymbiform, simple, 

 becoming at length bilocular with approximate sporoblasts, ^^ 



mic. Callopisma, Koerl. Syst. p. 129. Lecanora, Nyl. Lapp. 



Or. p. 129. 



On mosses, Greenland (Breutel), Nylander 1. c. 1866. 



Known to me in an European specimen from the author. It is 

 another offshoot of the cerinum-stock, separated, more widely 

 than the last, by the long spores, which are not polar-bilocular. 

 The lichen occurs in Greenland, according to Nylander I c., with 

 the whole aspect of the muscicoline P. cerinum v. stillicidiorum 

 of authors. 



19. P. sinapispermum (Auct.) Hepp.; thallus running over 

 mosses, thin, granulate ; whitish ; apothecia small to very small, 

 appressed, biatorine, soon convex and sub-globose ; fulvous-fer- 

 rugineous, becoming ferrugineous-brown, and blackening ; the 

 obtuse, entire, concolorous margin soon disappearing. Spores 

 ovoid-ellipsoid, ^^ mic. ; but in three otherwise similar speci- 

 mens from Behring's Straits the spores occur |^| mic. Blas- 



tenia, Koerb. Syst. p. 184. B. leucorcea, Th. Fr. Scand. p. 392. 



Upon mosses, in arctic and alpine regions. Greenland ( Vahl), 

 Th. Fries I c. 1861. Islands of Behring's Straits, Wright. Brit- 

 ish Columbia, Macoun. Eocky Mountains, Hall. An extreme 



member of the stock of P. cerinum, looking toward the next 

 species. 



20. P. ferrugineum (Huds.) Hepp.; thallus sub-cartilagin- 

 eous, at first contiguous, becoming chinky, verruculose, and 

 rugged; more or less ash- coloured, or now whitish; upon a 

 black, more or less obvious, or now even obsolete hypothallus ; 

 apothecia' from almost middling to small, for the most part 

 biatorine, sessile, flattish; disk opake, sub - pruinose, rust- 

 coloured, passing into red, and fulvous, bordered by a finally 

 crisped, persistent proper margin, which is now inclosed in a 



demiss thalline one. Spores ellipsoid, -^ mic. Parmelia, 



Fr. L. E.p. 170. Caloplaca, Th. Fr. Scand. p. 182. 



b. Pottinii ; thallus thin, whitish, or obsolescent ; apothecia 

 biatorine, soon turgid ; olivaceous and blackening, more or less 

 greenish-pruinose ; the paler margin at length excluded, or 

 12 



