PERTUSARIA. 213 



heaps. Spores solitary ; or often in twos ; mic. - Nyl. 



Scand.p. 179. Th. Fr. Scand. p. 309. P. faginea, Tuck. Syn. 

 N. E. p. 84, max. p. 



Trees, and more rarely rocks, throughout the United States, 

 Tuckerman Gen. 1872. Common equally throughout the North 

 and South, reaching Texas, Wright ; and also California, Bo- 

 lander ; and Oregon, Hall. 



5. P. dactylina (^ch.)Nyl.; thallus incrusting, thin; white; 

 producing finger-shaped, erect, thickish, somewhat divided, 

 (now undeveloped and inconspicuous) cylindrical branchlets, in 

 the tips of which the small, sub-lecanoroid apothecium with 

 pale-flesh-coloured disk, concealed more or less by a thalline 

 veil is contained. " Spores solitary ; ^|^ mic." - Nyl. Lapp. 

 Or. p. 240. Th. Fr. Scand. p. 310. 



On the earth, running over mosses, etc., in alpine districts. 

 Islands of Behring's Straits (Wright), Tuckerman Gen. 1872. 

 White Mountains. 



6. P. ambigens (Nyl.) Tuck.; thallus cartilagineous, smooth 

 becoming rugose-verrucose ; glaucescent ; apothecia small to 

 almost middling-sized, lecanorine, sessile or a little elevated'. 

 1-2-thalamous ; disk flat, from flesh-coloured becoming dark- 

 greenish and livid, with a thin bloom; thalline margin irregu- 

 larly torn-crenate, and at length repeatedly duplicated. Spores 

 in eights ; ~ mic. -- Tuck. Obs. Lich. 4. 1. c. p. 176. Lecanora, 

 Nyl. in Prodr. Fl. N. Gran. p. 40, note. 



Trunks, Oregon, Dr. Lyall. Hall. Elsewhere known only 

 at the Cape of Good Hope ; Zeyher in herb. Sender. 



7. P. lecanina, Tuckerm. ; thallus thin, contiguous, smooth, 

 becoming granulate; pale-yellowish; bordered by the black 

 hypothallus; apothecia small, lecanoroid, sessile, at first white- 

 pruinose; disk pale-flesh-coloured, sub-margiuate ; thalline mar- 

 gin entire. Spores in twos; ^'^ 2 mic. - Gen. Lich. p. 126, 

 note. 



On various trees in California, Bolander; seen only in small 

 patches accompanying P. leioplaca, and P. pustulata. 



8. P.flavicunda, Tuckerm.; thallus cartilagineous, smooth, 

 verrucose-areolate ; pale sulphur-coloured; the areoles becom- 

 ing radiously concrete toward the circumference; apothecia 



