328 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
the plant was collected, east or west—nor whether it was corticolous or saxicolous *. 
The corticolous form occurs in Lapland, Nordland, and the Samoyede country, on Betula, 
Populus, and Salix caprea—rarely fertile, but bearing sometimes the parasitic Celidium 
Stictarum, Tul., which is regarded as a fungus by Th. Fries (Arct. p. 50) +. The saxi- 
colous forms, which are frequently dissociated as S. linita, Ach. (e.g. in Th. Fries's 
‘Arct.’ p. 50), from corticolous states, occur in various parts of North America, and may 
also be met with on the Greenland side of Davis's Straits. Neither is this form or pseudo- 
species, however, recorded by Th. Fries as a Greenland lichen, while he describes it as 
very rare in Northern Scandinavia, 
Gen. 15. PARMELIA. 
1. P. saxatilis, L.—Jakobshavn, on granitic rocks, close to the sea; Egedesminde ; 
Illartlek glacier.—“ Very common everywhere" in the districts visited by Dr. Brown. 
Many and frequently puzzling forms occur, always sterile, often deformed, and occasion- 
ally the seat of parasitic Micro-lichens or Micro-fungi. All the ordinary European varieties 
occur (leucochroa, Wallr.; omphalodes, L.; and panniformis, Ach.), with innumerable 
 passage-forms or intermediates. But that form which is both the commonest and the 
most remarkable, is what may be appropriately distinguished as 
Spherophoroidea—in which the greater portion of the thallus (the periphery being gene- 
rally excepted) is covered and concealed by a dense compound-isidioid growth, which re- 
sembles a series, densely aggregated, of specimens of Spherophoron coralloides in miniature, 
These anamorphoses of the thallus—these Sphzrophoroid growths—convert a foliaceous 
thallus into the semblance of a crustaceous or fruticulose one. While generally constitut- 
ing a surface which is nearly level or uniform, these growths are sometimes also developed as 
subspherical masses, y detached and quite comparable with the concentric and erratic 
forms of P. sinuosa 1, and with the spherical warts of Lecanora tartarea and L. ventosa, 
though they are on a smaller scale than the former, and on a larger scale than the latter, 
tumour-like deformities. Every gradation exists between the simply isidioid and the 
compound isidioid or sphxrophoroid conditions, the colour of the central deformed por- 
tions of the thallus being usually deep bronze. 
The sphzrophoroid forms of saxatilis have apparently certain characters in common 
with Parmelia isidiocera, Nyl. (Syn., p. 382), collected at Cape Krusenstern, W. Arctic 
America, lat. 67”, by Beechey. Its thallus has the facies of levigata, is smooth peri- 
pherally, white within; the apothecial exciple and isidia yellow within; the latter mostly 
ramulose. The plant is fertile, and is allied to P. aurulenta, Tuck. $, a North American 
species. I have not seen a specimen of P. isidiocera. But I doubt its being a good 
. * Compare remarks in paper on the “ Greenland Lichen Flora,” formerly quoted, (p. 305). 
+ Vide Papers on “ Arthonia melaspermella,” Journal of Linnean Society, Botany, vol. ix. p. 278; and * Otago 
pue and Fungi,’ p. 449. 
i Vide the author's * Monograph of Abrothallus,” Quart. Journal of Miseria Science, vol. v. 1857 (sub nom. 
P ee ; or Mudd's * British Lichens’ (p. 96, sub P. sinuosa). 
$ Compare also P. rd Ach. (Tuckerman, * Synopsis of North-American Lichens, 1848, p. 25). 
x 
