LICHENS AND LICHEN. PARASITES

162 B.A.N.Z. ANTARCTIC RESEARCH EXPEDITION
Thallus crustose, uniform ; ecorticate ; algae protococcoid, medulla loosely woven, of thin-
walled hyphae. Apothecia sessile, more or less constricted at the base; amphithecium essentially
a continuation of the thallus with the algal layer disappearing early; paraphyses dichotomously
branched at acute angles forming a denser palisade with a densely wove11 epithecium; asci
2-4-spored ; ascospores large, hyaline multinucleate, sheath thin.
LECANIDIVM CRQZETICVM Dodge, sp. nov.
Type: Crozet Archipelago, Possession Island, Amercan Bay, B.A.N.Z.A.R.E. B20.
Thallus crassus, albidus, KOH-, areolato-rimosus, margine crasso sed non lobato; cortex
circiter 80p crassitudine, hyphis tenuibus ltnastomosantibus laxe contextus, plus minusve periclinalibus,
cum crystallis parvis; stratum algarum protococcoideum, circiter 30p crasstitudine,
discontinuum, coloniis cellularum 6-7p diametro; medulla similis cortici, laxius contexta cum paucis
aut sine crystallis. Apothecia ~essilia aut btsi subconstricta, circiter 1 mm. diametro, solitaria,
disco plano, cretaceo; amphithecium 180-200p crassitudine simile cortici thallino, gonidiis mox
evanescentibus ; hypothecium circiter 90p crassitudine, hyphis dense contextum ; thecium 425-450p
altitudine; paraphyses tenues, dichotome ramosi, epithecio 160-170p crassitudine cum crystallis
prirvis; asci circiter 250 X 50p muro 18-20p crassitudine, 2-4-spori; ascosporae hyalinae,
120 X 55p, muro tenui, obovoideae.
Thallus thick, white, KOH-, areolate rimose, margin thick but not lobed; cortex about 80r
thick of loosely woven, slender, anastomosing hyphae, more or less periclinal with very small
crystals; algal layer protococcoid, about 30p thick, discontinuous with colonies of small cells,
6-7p in diameter; medulla of the same texture as the cortex or somewhat more loosely woven and
few or no crystals. Apothecia sessile or somewhat constricted at the base, about 1 mm. in diameter,
solitary, disc plane, chalky ; amphithecium 180-200p thick, of the same texture as the cortex, algal
cells soon disappearing so that scarcely a living algal cell can be found in a mature apothecium ;
hypothecium about 90p thick, of densely woven, deeply staining hyphae; thecium 425450p tall:
paraphyses slender, dichotomously branched at very acute angles, forming a dense palisade
between the asci and ending in a densely woven epithecium, 16-17p thick, not staining and with
abundant small crystals; asci about 250 X 50p, wall about 18-2OP thick, protoplast clavate,
2-4-spored ; ascospores hyaline, about 120 X 55p, wall rather thin, apparently obovoid.
From my material, I have been unable to find mature spores in a position to measure them
accurately. Most of the asci are just begil;ning to differentiate spores. The one mature spore
found was still within the thecium and in such a position that its measurements and the thickness
of its sheath are uncertain. The species differs from Pertusaria Werthii. in the surface of the
thallus not staining with KOH, although the medulla stains light yellow in sections, the thecium
and spores remain hyaline in KOH, nea~ly complete absence of algae from the amphithecium (Zahlbruckner
figures a well-developed, continuous algal layer) also in the apparently much larger
spores..
Growing over very porous lava, alone or with Xanthoporina. kerguelensis, Steinera Werthii,
\
Pannericl dkhroa, Leeidea superjecta and Rinodina aspin'lina.
Crozet Archipelago : Possession Island, American Bay, B.A.N.Z.A.R.E. B20-3, B20-6, B20-7.
LECANIDIUM SUBFQLIOSUM Dodge, sp. nov.
Type : Kerguelen, Observatory Bay, B.A.N.Z.A.R.E. B188-2.
Thallus crassus, subfoliosus, muscos investiens, orbicularis, ad 2 cm. diametro, albus, margine
lobato, lobis rotundatis, circiter 1 mm. latitudine, 2-3 mm. longitudine. Apothecia circiter 1 mm.