LICHENS AND LICHEN. PARASITES

174
B.A.N,.Z. ANTARCTIC RESEARCH EXPEDITION
paratheciuln 10-15p crassitudine, hyphis hyalinis, periclinalibns, tenuibus ; hypothecium ca. 7 3,1
crassitudille, hyphis crassiorihus, leptodermeis; thecium ca. 4 0 ~ altitudine; paraphyses
pachydermeae, 2p diametro, semel bisve dichotome super ascos ramosae apicibus clavatis, subincrassatis,
in strat0 gelifacto viridi-nigricanti; asci clavati, primum ca. 21 X lop, apicibus
incrassatis, protopla~tis truncatis cum mamillis longis, truncatis, deiii subsphaerici, 18 X 14p,
leptodermei; ascospoi-ae hreviter ellipsoideae, 6-7 X 3.54p, uniloculares, hyalinae, episporio
modice incrassato.
Thallus umbilicate, polyphpllous, but folioles more or less concrescent in flattened cushions,
deeply folded and cerebriform, nearly covered with apothecia, circular, up to 1.5 cm. in diameter,
parts exposed to light between the apothecia cream buff to chamois, shaded parts and lower surface
ochraceous tawny, somewhat rugose but much smoother than the upper surface ; upper cortex about
?Op thick, loosely fastigiate, of dark greeiiish hyphae about 4~ in diameter, forming isodiametric
periclillal hyphac; algal layer 3540p thick, in some places continuous, in others of discrete
cells above, overJai11 by a hyaline, gelified layer 10-12p thick, seemingly formed of very slender
spherical colonies, cells cystococcoid, mostly glop in diameter; medulla loosely woven, of slender,
thick-walled hyphae about 2p in diameter, in looser portions 5-6~, branched and anastomopecl;
lower cortex fastigiate, of vertical, branched and anastomosing hyphae, imbedded in a gel, 40--60p
thick ; without rhizinae.
Apothecia sliglitly stalked at first, disc flat, level with the exciple, expanding irregularly,
cinllamoll rnfous, soon blackening, convex, often coalescent in cerebriform masses, practically
covering the upper surface of the thallus; apothecium not differentiated from the thallus (i.e.
the apothecium is essentially immersed in the cortex of a thalline wart) ; algal layer continuous
~ulder the pamthecium; parathecium 10-1Sp thick, of slender hyaline, periclinal hyphae; hypothecium
about 15p thick, of coarse, thin-walled decply staining hyphae ; thecium about 40p tall ;
paraphyses thick-walled, 2p in diameter, once or twice dichotomous above the asci, tips slightly
clavate, imbedded in the epithecial gel which is nearly hyaline in thin sections, dark greenish
black in thick sections; asci clavate, 20 X lop at first with thick hyaline tip, protoplast truncate,
with a long, truncate mammilla, becoming subsphaerical, 18 X 1 %~; ascoapores short ellipsoidal, 6-7
X 3.5-4~ with moderately thick epispore.
This species is closely related to 0ntpha.lodiunt quartz~nz (Darb.) Dodge & Baker, but the
systenlatic positioi~ of both is not clear. Both resemble Lecanora, sect. Placodiwn in genrral
appearance and microscopic structure except for the well-developed lower cortex. On the other
hand it must be adinitted that, in several details, the microscopic anatomy is quite suggestive of
Ontphalodiunt. U~ifortul~ately spermogonia have not yet been found in either species. ,
ICing Geo~ge V r~aild : Mt. Murchison, 1,860 ft., A. L. McLean, A.A.E. 14-2; Horn (Dreadnought)
Bluff, A: L. McLean, A.A.E. 37-1, 34, 47 type, 54.
ASPICILIOPSIS Miill.-Arg.
Placodiuna sect. Asp'cdiopsis Miill.-Arg., Bot Jahrb. [Engler] , 5, 135 ; 1885 : Forschungsreise
S. M, S. "Gazelle," 4, 10; 1889.
Lecanora sect. Aspiciliopsis Zahlbr. ap. Engler & Prantl, Die Nat. Pflanzenfam. I, I*, 203 ; 1907.
Type : Urceolaria macrophthalma Tayl.
Thallus very thick, areolate in the centre with a radiate margin which often becomes free
from the substrate; ecorticate on both surfaces; algae protococcoid, but often replaced in part by
the cephalodial algae ; medulla thick ; cephalodia large, floriform, with Stigmienta. Apothecia
innate with a thin parathecium of periclinal hyphae which becomes brownish to almost black,