OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 201 
Sproirus 20. S. glabra, Tayl. 
I do not regard this as a good species, but I am not prepared to allocate it. 
Specimen 1.—Falkland Islands, Antarctic Expedition, 1839-45, Dr Hooxer. 
In the character of its thallus, as well as of its spermogones, it closely resembles 
Ricasolia herbacea. The latter organs are abundant about the margins of the 
lobes, as large distinct papilla, marked on the apex by a round, brown spot 
which surrounds the ostiole. Sometimes they are grouped in twos or threes, 
though they are usually scattered singly; but they are seldom or never confluent. 
The spermatia are rod-shaped, and from gth to smth long; the sterigmata are 
composed of short, cubical, thick-walled cellules. 
SPECIES 21. S. pallida, Hook. fils. 
Specimen 1.—On the branches of decayed and live trees; forests, Kaipara, New 
Zealand, coll. by S. Mossman, 1850, No. 788; in Herb. Royal Botanical Garden, 
Edinburgh. This species appears to belong to the S. pulmonacea group of Stictas ; 
its laciniz are narrow and sub-linear; the lacunze deep; the rugze correspond- 
ingly prominent; the spermogones studded over these ruge, immersed and 
punctiform. 
GENUS II. Ricasouia, DN., Myl. 
The separation of this genus from Sticta, I have already pointed out, appears 
to me to be an exceedingly arbitrary and mischievous one. So far as the sper- 
mogones are concerned, most assuredly no distinction can be drawn between the 
two genera, for I have shown, under Sézcta, that several species of that genus have 
papillzeform spermogones as large as, nay even sometimes larger than, thoseof 
any of the Ricasolas, while others have papilleeform spermogones of the same 
character as those of Azcasolia, though somewhat smaller. I have also shown 
that it is very common for the same species of Sticta to have indiscriminately, 
papilleeform or punctiform spermogones, which latter may further possess flat or 
depressed ostioles. Precisely the same thing occurs in Ricasolia. In #. corrosa 
and &. Kunthii, | have found the spermogones either papilleeform or punctiform, 
the latter with depressed or flat ostioles. In A. dissecta, the spermogones are 
usually punctiform and depressed, exactly as in the S. pulmonacea group of Stictas. 
Sometimes, in /t. dissecta, as is frequently the case in the Stictas, the ostiole is sur- 
rounded by a sort of thalline ring. Here also the spermogones are rarely papilla- 
form. In &. crenulata, again, they are usually papillzeform, but small; punctiform 
ones, however, also occasionally occur. Sometimes a ring of thallus round a de- 
pressed or flat punctiform ostiole gives the semblance of a papillze, when this does 
not really exist. The spermogones of Aicasolia may be described in general terms as 
VOL. XXII. PART I. oF 
