

OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 253 
ends of the laciniz, as inconspicuous, small, rounded, orange-coloured tubercles. 
They are chiefly old, containing no free spermatia; there are numerous sterile, 
elongated, hypertrophied sterigmata, which fill up the spermogonal cavity. 
Specimen 3.—St Catharine’s (Brazil), TWEEpIE; also var. farnenis, Ach., Nyl., 
from North America; in Herb. Hooker, Kew. In the latter variety, the spermo- 
gones are generally very distinct, large, deep orange-red tubercles, occurring in 
the axils of the branches or segments of the thallus, which are linear or filiform 
as in P. flavicans, and of a very light colour. 
Species 17. P. flavicans, DC., 
A beautiful Everniiform species, growing in Western Europe, Africa, Asia, Ame- 
rica, and Australia. 
Specimen 1.—Var. crocea, Ach., which occurs in the West Indies and Chili (sub. 
Cornicularia crocea, Ach.) ; from Dr Acnarius himself, 1809; in Herb. Hooker, 
Kew; no habitat given. In addition to the value belonging to the specimen 
from its being an authentic one from Dr Acuarius himself, it is interesting 
as bearing spermogones, which are not very common in this species. They are 
small papillee or warts, of the same colour as the thallus, scattered along the sides 
of the thicker segments of the thallus, nearer the base than the apex. ‘The ostiole 
is of a deep orange-red, much darker than the colour of the thallus, frequently 
.depressed ; in which event the papilleform spermogone assumes an urceolate 
character. The spermatia are rod-shaped, about youth long, and yanth broad ; 
on longish arthrosterigmata like those of P. parietina. But another kind of ste- 
rigmata also occurs; they are simple, linear, branching at the base as in /tama- 
lina and Lichina, about goth to zuth long; the spermatia, given off from the 
apices only, of these sterigmata are acicular, jth long, and sath broad. These 
two kinds of sterigmata occur in different spermogones; but on the same plant or 
specimen. ‘There is no reason to believe that the one is a rudimentary form of 
the other; for their structure and appearance differ ab cnitio. 
Specimen 2.—Var. cxilis, Mich., which occurs in equatorial America and Chili. 
New Orleans, Drummonp; in Herb. Hooker, Kew. The thallus is frequently of 
a very pale gray colour; it is studded over with small orange tubercles, which are 
_ spermogones. 
SPECIES 18. P. villosa, Dub., 
A beautiful species, occurring in Spain and Portugal, Africa and Peru, and a variety 
of which I have also found occurs sparingly in Ireland. From the pale-gray colour 
_ of the thallus, and the large size of the orange spermogones, the latter organs are 
| particularly conspicuous in this species. 
Specimen 1.—Portugal, Trans-Tagus Districts, on sea-coasts; coll. WELWITzsScH, 
No. 110; in Herb. Hooker, Kew; very fine specimens. The spermogones are 
| abundant as very prominent and large orange-coloured tubercles, somewhat 
VOL. XXII. PART I. 3 T 
