— 88 — 
P. conspersa f. isidiata (Anzi) Hue Lich. Ex. n. 702. 
The thallus except at the circumference constipate-isidiose, the exciple 
likewise clothed. 
On rocks. 
122, Cap a l’Aigle, Que. ; 73, Algonquin Park, Ont. J. Macoun. 
P. molliuscula Ach. Lich. Univ. p. 492. 
Reaction me K-|- orange. 
On earth. 
761, Old Wives Creek, Assa.: 760, Bow River Pass, Ry. Mts. : 762, Crows 
Nest Pass, Ry. Mts. J. Macoun. No. 316 D. N. Am. Li. labelled P. con- 
spersa stenophy lla, belongs here. 
P. centrifuga Ach. Methodus, p. 206. 
Reaction me K — . 
On rocks. 
3822. Blanc Sablon, Labrador, A. E. Waghorne: 775, Diggs Is., Hudson 
Straits, R. Bell; 752, Lat. 6i°, Long. 104°, J.W. Tyrrell; 773, Clearwater Lake, 
Labrador, A. P. Low: 774, Tadousac, Can.; 756, Lower Arrow Lake, B. C.: 
769, Summit Lake, Que. ; 772, Lake Nipigon; 770, Lake Superior, J. Macoun. 
Commonly found only infertile but some of the specimens well fruited. 
Easily distinguishable from P . conspersa which it somewhat resembles by 
its blackish-brown color below, in P. co?ispersa reddish-brown. 
P. diffusa (Web.) Th. Fr. Arct. p. 60. 
Reaction KI. 
On bark of trees and dead wood. 
3665, Laggan, Alta.; 3666, Yoho Pass, B. C.; 780, Jumping Pound Creek, 
Alta.; 777, Lower Arrow Lake, B.C.; 130, Banff, Ry. Mts.; 785, Cape 
Breton, J. Macoun. No. 4023 on old logs, Montmorency Falls, Que., J. 
Macoun, is provided with whitish soredia facies. P. hyperoptam, synonymous 
with P. ambigua of Tuckerman’s Synopsis, but the above is the old name 
and should be conserved. 
P. hyperopta Ach. Synopsis, p. 208. 
Reaction Ki. 
On old logs and fences. 
3664, Yoho Pass, B. C. ; (characteristic) J. Macoun; 786, Cape Breton J. 
Macoun, strongly resembles P. diffusa but is cinereo-glaucescent with 
whitish soredia; 3820, Labrador, Waghorne. 
This is P. ainbigua var. albescens of Tuckerman’s Synopsis. The 
Acharian name seems to have priority over albescens, Wallr. It is a curious 
fact that dealbate conditions of P. diffusa are often found growing with 
that plant, almost impossible of separation. But typical corticoline P. 
hyperopta is in our experience unaccompanied by P. diffusa. It will not be 
improper to use the designation albescens for the whitish states of P. diffusa. 
Section Hypotrachynae Wain. 
Group Cyclocheilae Arn. 
P. olivacea (L.) Ach. Methodus, p. 213. 
Reaction me C — . 
On tree trunks and branches of trees. 
