OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 181 
Hooker, Kew. The spermogones are longish, brown, irregular tubercles or warts, 
frequently becoming enlarged and deformed. 
Specimen 2.—On trees and pales, New England, U.S. America ; TuoKERM ANN, 
No. 6, exs. (sub Cetraria lacunosa, 8. Atlantica). The margins of the lobes are 
studded over with chiefly degenerate spermogones, which do not give so charac- 
teristic a fringe or denticulate appearance as in P. ciliare. Besides being marginal, 
the spermogones are frequently studded over the flat surface of the lobes near 
their margin. Cambridge, Massachusetts; on pales; TuckERMANN; in Herb. 
Menzies, Royal Botanic Garden, Edinburgh. The spermogonal fringe of the lobes 
is similar to that in P. care, but the spermogones are smaller. Sometimes 
they are studded over projections from the margins of the thallus. 
Species 7. P. ciliare, Ach. 
It is frequently confounded with P. sepincolum, but is distinguishable by its 
marginal spermogones, which are very distinct, constant, and crowded, and which 
give the thalline lobes a peculiar warted appearance. Its name has been conferred, 
it would appear, not in allusion to its spermogones, which might earn for it the 
name rather of denticulata, but on account of occasional marginal fibres,—strong, 
darkish, and branching,—with which it is also furnished. 
Specimen 1.—Schooley’s Mountains, North America, June 1856; Dr A. O. 
Bropiz. The spermogones are largish brown cones or warts; more abundant, 
more distinct, and more constant, than in any of the other species of Platysma. 
The thallus is greenish-gray, smooth and shining above, whitish and lacunose 
below ; the lacinize are sometimes narrowish. The spermogones somewhat re- 
semble those of P. sepincolum, which, however, I have met with only on the sur- 
face, not on the edges, of the thallus. The spermatia are acicular, and about 
yaoth long; the sterigmata are simple, or of a few articulations. 
Specimen 2.—Cambridge, Massachusetts, TuckERMANN; in Herb. Menzies, 
Royal Botanic Garden, Edinburgh; with apothecia. The spermogones are very 
distinct, barrel-shaped organs, seated on the ends of cilia, or tooth-like projections 
from the margin of the thallus. They thus somewhat resemble the spermogones 
of Cetraria Islandica, but are much shorter. The ordinary form of spermogones 
occurs in TUCKERMANN’s exs. No. 5; on trees and pales, New England, U. S. 
America. 
Speciges 8. P. sepincolum, Hoffm., 
Which occurs in Europe, America, and Asia. 
Specimen 1.—On trees, Ingleby Park, Cleveland, Yorkshire, 1854; collected by 
W. Mupp. The spermogones are abundant as small olive-brown prominent 
round tubercles or papillee; superficial or sub-pedicellate ; seated on slight pale 
VOL. XXII. PART I. 3A 
