LICHENS AND LICHEN. PARASITES

108 B.A.N.Z. ANTARCTIC RESEARCH EXI'EDITION
stratum discontinuum circiter 75p efficientes. Apothecia immersa dein elevata, nigra, subimmar-
gillata; parathecium hyalinum 55p crassitudine, hyphis radiantibns tenuibus, brumneis, dichoto~ne
ramosis; hypothecium tenue, 10-15p crassitudine hyphis subverticalibus; thecium 3OP altitu-
cline ; paraphyses tennes, apicibus non incrassatis, epithecio viridi ; asci ellipsoidei, apicibus
incrassatis, 25-26 X 12-13p; abcosporae octonae, hyalinae longe-ellipsoideae, obscure uniseptatae,
10-11 x 3-4p.
Thallus crustose, effigurate, with thick, lobed clarlrened margins, whitish becoming glaucous-
grey, centre rimose areolate; cortex 55p thick, of hyaline, thick-walled, subvertical hyphae densely
woven, becoming gelified and somewhat amorphous; algae protococcoid. in rounded colonies, cells
7-8p in diameter, forming a diseontinuous layer about 75p thick. Apothecia immersed at first,
showiiig as a small black disc, becoming elevated, black and almost immarginate; parathecium
hyaline, 55p thick, of slender brownish radiating, dichotomous hyphae imbedded in a gel, the outer
portioii being deep green; hypothecium thin, 10-15p thick, more deeply staining but not clearly
differentiated, of subvertical hyphae; thecium about 30r, tall; paraphyses slender, forking once or
twice above the asci, tips not thickened, epithecial gel not well developed, greenish; asci ellip-
soidal, tip thickened, protoplast slightly papillate, 8-spored, 25-26 X 12-13p; ascospores hyaline,
long ellipsoid, hyaline, rather thick-walled, obscurely uniseptate, 10-11 X 34p.
Growing over old Pertzuaria subperrimosa, Aspicilia endochlora and Lecanora atrocaesin and
on roclr with Rhizocarpo~i Johnlstoni and Buellia subplicata.
Kerguelen : Greenland Harbour, B.A.N.Z.A.R.E. B177-39.
Bacidiu DNtrs., Giorn. Bot. Ital., 1,-189 ; 1846.
BACIDIA DNtrs.
Type : Originally based on Lecidea rosella Ach. and L. carnea Ach. Since L. carnea Ach. has
been transferred from the genns, we may accept L. rosella Ach. as the type, as this would con-
serve the genus in the sense commonly used.
The synonymy of this very large and variable genus is very confused, hence I have not tried to
cite the numerous synonyms. Of the five species in our collections four belong in Eubacidia
Zahlbr. and one in sect. Weitenwebera Zahlbr. (Bilimbia DNtrs. non Reichb., Weitenwebera Opiz
non Schrank) .
Thallus crustose, homoeomerous or heteromerous, ecorticate ; algae protococcoid. Apothecia
sesqile, rarely somewhat immersed or almost stipitate, with flat to very convex disc; parathecium
light colourecl ; hypothecium hyaline ar darkening ; asci usually 8-spored ; ascospores hyaline,
.ng fusiform to acicular, 3-many-septate, walls and septa thin, cells cylindric, straight, curved or
helical. Spermatia acicular, straight or curved.
BACIDIA (BILIMBIA) LASERONI Dodge, sp. nov.
Type : King George V Land, Madigan Nunatak, 2,400 ft., 30 miles east of Winter ~uarters,
C. F. Laseron, A.A.E. 2.
Thallus glebosus, obscure viridis vel subniger; cortex 20p crassitudine, gelifactus, hyphis
periclinalibus; algae protococcoideae, coloniis 35-55p diametro, raro coduentibus, cellulis 8p
diametro, compactis; medulla hyphis tenuibus dense compactis. Apothecia circiter 0.15 mm.
diametro, stipitata, convexa, immarginata, disco rufo nigricante ; parathecium deest ; hypothecium
circiter 90p crassitudine, ab hyphis medullaribus non bene distinctum ; thecium 75p altitudine ;
paraphyses 2-~J.L diametro, ter dichotome ramosae, apicibus non incrassatis; asci clavati dein
dimidia parte superiori latiores, circiter 35 x %lop; ascosporae octonae, subfusiformes, hyalinae,
4-loculares, apicibus rotundatae, fascieulatim dispositae, circitrr 15 X 3p.
Thallus glebose, dark green to almost black, growing over tips of weathered Stereocaulon