120 PANffARIA. 



b. conoplea, Fr. ; thallus beset densely with gray soredia, 

 passing, at the centre, into a continuous crust, [apothecia zeo- 

 rine and biatorine]. Fr. I. c. Parmelia, AcJi. L. U.p. 467. 



Trees and rocks, New England, Tucker man Syn. N. E. 1848. 

 Ohio, Lesquereux. North, and South Carolina, Eavenel, etc. 

 Alabama and Mississippi, Peters, etc. Texas, Hall. California, 

 Dr. Palmer. Oregon, Hall. b, New England, Tuckerman. 



6. P. leucosticta, Tuckerm. ; thallus squamulose, cartilagin- 

 eous-membranaceous ; from brownish-ash-coloured becoming 

 tawny-brown; squamules of the circumference expanded, elon- 

 gated, and pinnately tabulate, those of the centre ascendant 

 and imbricated, dissected, dentate-crenate, the teeth white- 

 powdery; hypothallus thin, bluish-black; apothecia smallish 

 to middling, lecanorine, appressed; the red-brown disk at 

 length tumid, and excluding the thin, crenate, soon white- 

 powdery margin. Spores rounded and ovoid, simple, decolorate, 

 ^| mic. Obs. Lich. I c. 4,j?. 404. 



Rocks, and also trunks, common from New England to 

 southern Virginia, Tuckerman in Darliugt. Fl. Cestr. 1853. Ohio, 

 Lesquereux. North Carolina, Curtis. South Carolina and 

 Georgia, Ravenel. Alabama, Peters. Louisiana, Hale. 



7. P. pliolidota (Mont.) Nyl. ; thallus of minute, membrana- 

 ceous, rounded, crenate-lobulate, finally crowded and imbricate 

 squamules which are predominantly pale -yellowish-gray, but 

 are commingled more or less with lead-coloured ones; on a 

 thin, blackening hypothallus; apothecia small, lecanorine, ses- 

 sile, the incurved, crenate margin finally excluded by the pale- 

 to dark-brown disk. Spores ovoid-ellipsoid, simple, decolorate, 

 ljh| mic. Mont. Fl. GUI. p. 146. 



Trees, Mexico; Nylander. The lichen (in Montague's Juan 



Fernandez specimens) has not a little the aspect, in small, of a 

 pale P. Hypnorum, and the light-coloured scales are character- 

 ized by gonidia, as in that ; but a change takes place in some of 

 these scales, whereby they assume a bluish colour (extending 

 also in part to the exciples) and the scales exhibit then a pecu- 

 liar and more delicate crenelation, and offer only gonimia; 

 which appear to tie regarded as determining the place of the 

 lichen. 



8. P. Hookeri (Sm.) Th. Fr. ; thallus squamulose, sub-car- 

 tilagineous, more or less leaden-gray; squamules expanded, 



