—93 — 
P. saxatilis f. furfuracea (Schaer.) Lich. Helvet. Spiclg. p. 455. 
Differs from the species in being more or less isidioid. In high northern 
latitudes the isidia sometimes cover and completely conceal the thallus with 
a thick crust, except at the circumference. 
On rocks usually, but occurring on trees. 
656, Lower Arrow Lake, B. C. ; 633, Gaspe, Que. ; 659, Cape Breton, J, 
Macoun. 635, St. Paul’s Is., Bering Sea; 624, St. George’s Is., Bering Sea, J. 
M. Macoun. 3492, Blanc Sablon, Labrador; 3823, Bolster Rock, Labrador, A. 
C. Waghorne. 
P. saxatilis var. omphalodes (L.) Fr. Li. Eu. Ref. p. 62. f. caesio-pruin- 
osa Nyl. by Stiz. St. Gall. Nat. Ges. 1876, p. 206. 602. Cape Vancouver. 
Bering Sea. J. M. Macoun. 
No omphalodes proper found in the herbarium. The form is like the 
species in all except being pruninose throughout. It has been the habit of 
American lichen students to call any dark, reddish, brownish or blackening 
saxatilis, omphalodes, but the genuine form is shining and smooth, not 
opaque. The reddish or dark color of omphalodes or pseudo-omphalodes is 
due to a natural maceration with meteoric or other waters. 
P. SAXATILIS OMPHALODES f. PANNIFOMIS (Ach.) Nyl. by Stiz. 1 . C. 
Thallus densely imbricated, the lobes reduced and scale-like and some- 
times caesio-pruinose as in the last. 
On rocks 
654, Lower Arrow Lake, B.C. ; 650, Elbow River, Alta.; 648, Lake 
Nipigon, Onfe. J. Macoun. 
Panniform conditions of the species are sometimes seen with normal 
coloration, and it is probable that most of our dark colored panniformis is 
merely the product of discoloration. 
P. saxatilis var. laevis Nyl. Syn. I. p. 386. 
Thallus' smooth, rather shining, faintly and delicately reticulated, 
laciniae narrowed, discrete, below clothed densely with black rhizinae. Apo- 
thecia moderate, for the most part plane, chestnut- colored with an entire 
margin. 
On trunks. 
639, Cape Breton; 619, Mt. Benson, V. I.; 607, St. Anne’s des Monts 
River, Que.; 608, Jupiter River, Anticosti; J. Macoun; 606, Tobique, N. B. 
G. U. Hay. 
P. sulcata Tayl. in Mack. Flor. Hibern. (1836) p. 145. 
Synonymous with P . saxatilis var. sulcata of Tuckerman’s Synopsis. 
Reaction as in P . saxatilis. 
On old boards, posts and rails, trunks and also rocks. 
3304, Sable Is., N. S. ; 613, Belleville, Ont. ; 632, Comox, V. I. ; 649, Jump- 
ing Pound Creek. Alta.; 645, Lower Arrow Lake, B.C. ; 646, Hastings, 
B. C. ; 3655, Montmorency River, Que.; 3647, Cap a L’Aigle, Que.; J 
Macoun. Middleton Is., Alaska. J. M. Macoun. 
Differing sufficiently from P. saxatilis to be accorded specific rank, in 
the opinion of Nylander and others, the best argument for separation seems 
to be that there are no connecting or intermediate states between the two. 
