PYRENIDIUM. | PYRENIDEL. 81 
Tribe III. PYRENIDIEI Nyl. ew Cromb, Journ. Bot. 1874, 
p. 837; Flora, 1875, p. 103. 
Thallus maculate, radiately appressed; cortical layer distinct ; 
gonimic granules moniliformly coherent. Apothecia pyrenoid ; 
spores 4nz, septate, brown; paraphyses scarcely any. Spermo- 
gones unknown. 
A singular tribe, holding amongst the Collemacei an analogous place 
to the Pyrenodei amongst the Lichenacei. In this respect the family 
very appropriately closes with it; for the genus Odryzwm, with its 
pe apothecia, is now 
nown to be entirely parasitic, and 
must be removed. The Pyrenidiei 
consist of a single genus with a sin- 
gle species; further research may 
bring others to light. 
19. PYRENIDIUM Nyjyl. Flora, 
1865, p. 210.—Thallus minute, 
stellato-divided, fibrillose, the 
cortical layer cellular, distinct. 
Apothecia innate, scarcely promi- 
nent; spores oblongo-ellipsoid, 3- 
septate, brownish; paraphyses 
slender, few or obsolete; hyme- 
nial gelatine not tinged with 
iodine. 
Having regard only to the thal- bs Big 2, 
lus, this genus might be supposed Pyrenidium actinellum Nyl.—a. Thal- 
to be allied to Leptogium ; but the ee cageerpug a 30. " . se 
‘form of the apothecia separates iten- Ft te of the sar 350 a AG. 
ee ee pene ees A nimia. ¢@,é’. Vertical sections of two 
: thecia (viewed under water), x 30, 
yeason to doubt that the apothecia with oe aie ‘pores of ee 
really belong to the thallus and not thallus. f, Theca with spores, x 350. 
to a parasitic fungus. g. Two spores, x 500. 
1. P. actinellam Nyl. Flora, 1865, p. 210.—Thallus adnate, 
thinly crusteform, thinly stellato-fibriliose at the circumference, 
the fibrille equally cylindrical, sparingly branched, but usually 
effuse, and entirely covered by or almost entirely composed of 
somewhat erect fibrillee, sordid- or dark-olive (I+wine-red). Apo- 
thecia minute, scarcely prominent, almost entirely innate, the 
pyrenium entirely black ; spores 0,020-24 mm. long, 0,008-9 mm. 
thick.—Carroll, in Journ. Bot. 1865, p. 286; Cromb. Lich. Brit. 
p- 10; Leight. Lich. Fl. p. 36, ed. 3, p. 37. 
The thallus of this species (of which I give Nylander’s emended 
diagnosis) forms small macule on the substratum, which are more 
or less scattered, or at length confluent, When sterile it is externally 
very similar to states of Leptoyium microscopicum; but under the 
microscope its fibrille are seen to be equally cylindrical, while in 
G 
