— go— 
Very near to P. conspurcata but distinguishable by the surface and 
reactions. Reported from Isle Miquelon and collected in Maine by the 
writer, with probably a wider distribution. 
P. fuliginosa Nyl. in Flora, 1868. 
Reaction KI, Cl, me.K (C) -f- red. 
Thallus membranaceous, orbicular, appressed, brownish-olivaceous or 
darker, furfuraceous, fulginose or black-isidiose ; beneath blackish and spar- 
ingly rhizinose; lobes plane, crenate; apothecia moderate, brownish, the 
exciple thickened and slightly crenate. Spores U- 
P. FULIGINOSA f. LAETEVIRENS Krbg. 
Color of the thallus much lighter than the type, a medium green, the 
isidia concolorous. 
Only the form so far seen. 
On alders and fence rails. 
721, Hull, Que. ; 723, Ottawa, Ont. , J. Macoun. 
Similar to certain forms of P . olivacea, but kept apart by the reaction 
and isidia. Not previously listed from America, although the species cited 
from Labrador and Isle Miquelon. 
P. prolixa (Ach.) Nyl. Syn. p. 396. 
Reaction none. 
On rocks. 
3501, Labrador, Waghorne. 725, Lake Nipigon, Ont. J. Macoun. This 
is P. olivacea var. b. prolixa of Tuckerman’s Synopsis. 
P. prolixa f. panniformis Nyl. Syn. p. 397. See Tuck. 1. c. 
729, on rocks, Victoria, V. I. J. Macoun. 
P. sorediata (Ach.) Nyl. in Flora, 1879. 
Reaction none. 
On rocks, 
728, Galt, Ont.; 3446, Algonquin Park, Ont.; 729, Black Water River, B. 
C. ; 730, Nipigon River, Ont. J. Macoun. 
P. olivacea var. c. sorediate of Tuckerman’s Synopsis. 
P. dubia (Wulf.) Schaer. Enumer. p. 5. 
Lichen dubius , Wulf. in Jacq. collect. IV. p.275, tab. XIX, fig, 1. 
The antique name for P. Borreri Ach. No specimen of this species was 
found in the herbarium, a rather remarkable fact, and one confirming the 
specific rank of P. rudecta. 
P. rudecta Ach. Synopsis p. 197. 
Reaction me. C+ red, soredia C+ red. 
On trunks and old rails. 
3631, Peele Point, Ont ; 3654, Montmorency River, Que.; 904, Brighton, 
Ont., J. Macoun; 605, Edmonton, Ont. J. White. 
P. Borreri var. rudecta of Tuckerman’s Synopsis. This plant 
deserves specific rank equally with such isidiose forms as P. crinita, P. 
pilosella , P. sulphurata etc. The writer has yet to examine transitional 
states between the present and P. dubia , if such exist. 
