OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 1438 
matia appear to me to be simply linear and rod-shaped, of equal width through- 
out; while NyLANDER describes them as slightly thickened at both ends. This 
difference in our observations might arise from his using higher magnifying 
‘powers than I am in the habit of employing. Probably this character, if it 
exists, is not a very prominent one. In respect of size and thickness of walls, 
the arthrosterigmata of this genus, like those of Bwomyces, are intermediate be- 
tween those of Sticta and those of Parmelia,—the sterigmata in the latter 
having longer and fewer articulations or cells; those in the former genus being 
altogether broader and stronger, the component cells being more cubical, and 
having much thicker walls. 
Species 1. 7. vermicularis, Scherer. 
(Syn. Cenomyce, Ach.; Cladonia, D.C.; Cladonia a maurocrea B vermicularis, 
Kors. 26.) 
Specimen 1.—ScHRER exs. 86 (sub Cladonia vermicularis a subuliformis.) 
On the ground in alpine situations; Switzerland. The specimen includes two 
forms of the plant, viz., a larger, coarse, and turgid form, corresponding to the 
var. turgida of Cladonia uncialis, and a smaller, ordinary, vermicular form. 
It is on the former, more particularly, that the spermogones occur. This is the 
only case in which I have as yet satisfactorily seen the spermatia and sterig- 
mata of the spermogones. The latter occur abundantly as largish, prominent, 
roundish, flattened, or irregular warts, of the same colour as the thallus, with an 
obscure, central, stellate-fissured ostiole. The internal walls are formed of 
arthrosterigmata, resembling those of Sticta and Collema. They consist of short, 
thick-walled cells, irregularly articulated_so as to give the whole sterigma a very 
zigzag outline. The spermatia are small, rod-shaped, about ~,th long, with a 
breadth of ,,;,th, bristling over the sterigmata, as in the genera above named, 
and attached to the apices of the individual articulations or cells. In external 
aspect the spermogones are somewhat analogous to those of Usnea and Ramalina ; 
but they are generally isolated and sparingly scattered in Thamnolia. 
Specimen 2.—Falkland Islands; Antarctic Expedition, 1839-43 ; Dr Hooxsr. 
The hollow, vermicular, creeping stems are dotted over with minute, black, 
round, immersed bodies, frequently depressed or flattened, which bear a close 
resemblance to the spermogones of /occella. ‘These, however, are the parasitic 
apothecia of a Lecidea. The thece are irregularly obovate, bulging here and 
there from pressure by the contained spores, not tapering below into a pedicel, 
but sac-like, and resembling the thecee of Avthonia. They do not give a blue 
reaction with iodine. The spores are’ eight in each theca, brown, 1-septate, 
oblong-oval, with a constriction opposite the septum, which gives them a figure- 
of-eight appearance. I am not aware that this parasite has been hitherto 
described; and I therefore venture to propose for it, in allusion to its habitat, 
