202 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
precisely those of Sticta, with the single exception, that they are more generally large 
and papilleeform, resembling nascent apothecia. They are generally so large as 
to be visible to the naked eye, as in R. herbacea. Their diameter in this species is 
about sth to jth; in. R. glomulifera, th to th. They are frequently confluent, 
in which case they become still larger irregular tubercles, with a somewhat de- 
pressed apex. Occasionally the spermogones are flat, lurid, or deep-brown macule, 
as in certain forms or varieties of R. glomulifera. The ostiole is usually small and 
round; with age, it becomes frequently stellate-fissured, or it expands into a 
saucer-shaped cavity, with dark, turgid, irregular edges, when the nucleus or 
body of the old spermogone falls out. The thallus is sometimes studded over with 
black, very irregular perforations, where there existed old spermogones, whose 
nuclei have fallen out. The patent irregular ostiole frequently gives the spermo- 
gonal papilla the aspect of a young apothecium, as in R. herbacea and R. glomuli- 
jera. In regard to site, the spermogones may be either scattered over the general 
surface of the thallus, or chiefly on or about the margins of the lobes. They are 
peripheral in &. dissecta, crenulata, Kunthii, and coriacea. Sometimes they 
occur on large, deformed, wart-like growths of, and from, the thallus, resem- 
bling those of Parmelia saxatilis, on which Lecidea Smithii grows. Occasion- 
ally they are met with, seated directly on the margins of the lobes, to which 
they give a coarsely denticulate character, as in the analogous form of Parmelia 
perforata. Here they are rather barrel-shaped than mammillar or papilleeform. 
The internal tissue, spermatia and sterigmata, are quite those of Sticta. The 
typical species of the genus, /. herbacea and R&. glomulifera, were formerly in- 
cluded among the Parmelias by Scumrer and other authors, but I long ago 
pointed out that they really belong to Stzcta.* 
SPECIES 1.’ R. herbacea, DN., 
Which occurs in Europe and America. The spermogones are usually abun- — 
dant and very distinct ; hence this is one of the best species in which to study 
the spermogones of Aecasolia. Parmelia perlata is not unfrequently confounded 
with it; but the character of the spermogones suffices at once to distinguish 
these two lichens,—those of the Parmelia being punctiform, very minute, 
black, and immersed. ‘The large papillar or mammillar spermogones of £&. her- 
bacea have the same tint as the thallus, of which they appear to be elevations, 
with the exception of the ostiole, which is in the centre of a brown areola or spot 
seated on the apex of the cone. The spermogones are flattened or depressed at 
the apex; they closely resemble young apothecia; and the only safe way of dis- 
tinguishing them is by microscopic examination. The internal tissue is white, 
dense, horny, semi-transparent when moistened, of a grayish or pale rose tint. 
* Popular History of British Lichens. London, 1856, pp. 189 and 191. 

