OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 139 
apothecia, which frequently assume similar appearances. The microscopic struc- 
ture at once distinguishes them. These warts, both spermogonal and apothecial, 
are frequently pruinose, or covered by a fine dust, derived from the surface of 
the thallus, which pruina obscures their naturally black surface. Sometimes the 
black ostiole is sunk in the thalline wart, which forms a pale, sub-prominent mar- 
gin around it. But more generally, as I have already mentioned, it is flattened 
or convex. The spermatia in all the different forms of spermogone just described 
are very beautiful and delicate, about ;4,th to ,4,th long, and curved or twisted 
like those of the subfusca group of Lecanoras. They are borne on the apices of 
linear delicate sterigmata, which are sub-ramose at the base, and are closely 
ageregated. The form of the immersed body of the spermogone is spherical, its 
cavity simple, and. the internal tissue, though originally white, becomes brown 
with age. 
SPECIES 2. R. fuciformis, Ach., 
Which, though not quite so extensively distributed as the preceding species, yet 
occurs in Europe, Africa, and America. 
Specimen 1.—ScH&RER, exs., 553; maritime rocks, shores of the Atlantic ; 
Pe.ver. One large segment of the thallus is studded over with prominent, irre- 
gular, black tubercles, which are old spermogones, containing no free spermatia. 
Specimen 2.—\Imported from Lisbon into Liverpool under the name of “ Chicken- 
weed,” for the British Orchill manufacture; sent by Rev. W. A. Lercuton, April 
1856. The spermogones are sparingly scattered towards the extremities of the 
lacinize, as largish, black, distinct points. The spermatia and sterigmata differ 
considerably from those which occur in the spermogones of African specimens. 
The former are oblong or rod-shaped, very minute, resembling those of Ramalina, 
being about ~ th to — th long; the sterigmata also being like those of Ramalina. 
6500 5000 
Specimen 3.—Imported for the British Orchill manufacture, probably from the 
west coast of Africa; used in the manufacture of Orchill, under the name of “ mixed 
Orchella weeds,” by Messrs Ropinson, Huddersfield. Many of the specimens, 
at least, are corticolous, for they are found with small portions of the twigs of 
trees or bushes attached. The spermogones are abundantly scattered over the 
laciniz as minute, round, brown points. These points or ostioles sometimes are 
surrounded by a pale thalline ring or margin, and they then somewhat resemble 
young apothecia. The spermatia are generally sickle-like or curved, not twisted 
or vermiform, about ,;th long. The sterigmata are longish, linear, simple, deli- 
cate. In some specimens, in abundant fructification, the spermogones are unusu- 
ally large and distinct, scattered among the apothecia. The spermatia are rod- 
shaped or straight, about .,th long. The sterigmataare short and sub-ramose at 
base. Occasionally the apothecia are dotted over with black, punctiform, de- 
pressed spermogones; they are rendered distinct, when they occur, from con- 
