260 HERRE 



cia small and very small; disk blackish brown; margin entire, scarcely 



ciliate; "spores - - /*", Tuckerman. 

 14 22 



Occurring very rarely with us, on trees. A wide spread but not 

 very common lichen. 



ii. PHYSCIA OBSCURA (Ehrh.) Nyl. 



Lichen obscurus Ehrhart, PI. Crypt, no. 177. 1785. 



Physcia obscura Nyl. Act. Soc. Linn. Bordeaux, series 3, I: 309. 



1856. 

 Physcia obscura Tuck. Syn. N. Am. Lich. I: 76. 1882. 



Thallus sub-orbicular or sub-stellate, appressed, smooth, not prui- 

 nose; lobes narrow, many-cleft, flat or slightly convex, sorediate; 

 marginally hispid or pseudo-cih'ate; centrally it may pass into small, 

 overlapping lobules, or become crustaceous and disappearing, leav- 

 ing the marginal lobes only; brownish-gray mouse-color to dark 

 brown; beneath black, more or less clothed with black fibrils. 



No fruiting specimens have yet been collected here. 



Not abundant or conspicuous with us; best developed on bark, but 

 occurring likewise on rocks, usually with stellate and much reduced 

 thallus. 



A variable and cosmopolitan lichen. 



LXIV. Anaptychia Korber. 

 Anaptychia Korber, Sys. Lich. Germ. 49. 1855. 



Thallus foliaceous or fruticose, much lobed or branched, prostrate, 

 ascendant, or erect, usually with rhizoids on the lower side; lobes 

 broad to linear, smooth or channelled, often fibrillose; dorsi-ventral 

 or radial, both sides or only the upper with an almost cartilaginous 

 cortex of longitudinal, agglutinated hyphae, not forming pseudopar- 

 enchyma; the algae lie either under the upper cortex or also next the 

 under cortex. 



Apothecia circular, sessile or terminal, lecanorine; disk dark, prui- 

 nose or naked; hypothecium clear, the paraphyses simple; spores 

 brown, ellipsoid to elongate, bilocular, with thick walls. 



Species few, oi wide distribution, occurring on earth, rocks, moss, 

 and bark. 



