LICHENS AND LICHEN. PARASITES

236 B.A.N.Z. -4NTARCTIC RESEARCH EXPEDITION
Type: X. purietina (L.) Th. Fr.
Thallns foliose, dorsiventral, corticate on both sarfaces, with ~.hiziiiae; cortcBs p ~~d~pi~~
chymatons from vertical hyphae, cells thin-walled; algae protococcoid; medulla of loosely woven
branched, thin-walled hyphae. Apothecia sessil c or short stipitate ; ainphithecinm present ; hypo-
thecium liyaline, paraphj-ses septate ; asci 8-spored ; ascospores polari-bilocular, hyaline. Spemo-
goiiia in small warts, spherical; sperlnatiophores septate; spermatia long ellipsoidal.
XANTI-IORIA MAWWNI Dodge, sp. nov.
Type : George V Land, Cape Denison, A.A.E .38.
Thallus pulrinatns, ad 2 cm. diametro, 6 mm. altitudine, lobis cuneatis, snperficie punctatoimpressa,
rugosa vel subscrobiculata, margine fimbriato-lacero, lobulis ca. 0.5 X 0.1 mm., teretis
applauatisve, vel microphyllinis, ochraceus in locis umbrqsis aurantiacorufus vel umbrinus in
locis insolatis ; rhizinae parvae, male evolutae ; cortex superior 18-2OP crassitudine, pseudoparenchymaticus,
cellulis irregularibus, ad 5~ diametro, exteris crystallis minutis, bruilileis inspersis;
stratum algarum ad 3OP crassitudine, cellnlis sparsis 18-2OP diametro, vel in coloniis parvis;
medulla ca. 5OP crassitudine, laxissime contexta, hyphis leptodermeis, irregularibus, ramosis
aiiastomosantibusque; cortex inferior superiori similis.
Thallus in pulvinate tufts up to 2 cm. in diameter, 6 mm. tall, lobes cuneate, surface punctate
impressed, rugose and suhscrobiculate, margin fimbriate lacerate, ultimate lobules about 0.1 mni.
in diameter and 0.5 mm. long flat or nearly terete, sometimes submoniliform or microphylline,
shaded portions ochraceous buff, portions exposed to sun orange rnfous to Sanford's bro\\rn,
attached by minute holdfasts ; rhizinae occasional, small, poorly developed ; upper cortex 18-20;~
thick, pseudoparenchymatous; cells irregular in size, up to 5p in diameter, outer 5~ heavily incrusted
with minute brownish crystals; algal layer up to 3OP thick, more or less discontinuous, of scattered
cells 18--20p in diameter or in small colonies; medulla about 5OP thick, very lax, of thin-walled,
irregular, branched and anastomosing hypha~, with occasional algal cells next lower cortex, which
is similar to the upper cortex in structure and thickness.
Most of our material is growing over soil and mosses. The specimen from Hippo Nunatak.
A.A.E. 27 is much smaller, lobes flatter, growing on rock but seems to belohg here. In this the
rhizinae are about 7 5 in ~ diameter with a cortex of dark brown, thick-walled hyphae, about 5!t in
diameter, cells 8-12~ long; medulla of longitudinal, conglntinate, nearly hyaline hyphae about 4p
in diameter.
Icing George V Lalid : Cape Denison, A.A.E. 17,38 type, 113, B.A.N.Z.A.R.E. 53644,53645,
53646.
Queen Mary Land : Hippo Nunatak, C. T. Harrisson, A.A.E. 26,27 ; David Island, C. T. IJarrisson,
A.A.E. 29, 30; Alligator Nunatak, C. T. Harrisson, A.A.E. 28-3.
M'acRobertson Land : Cape Bruce, R.A.N.Z.A.R.E. 108-37.
MAWWNIA Dodge; gen. nov.
Type : M. Har~issoni Dodge.
Thallus fruticu!osus, prostratus, cortex hyphis longitudjnalibns, coilglutinatis; algae protococcoideae;
medulla laxe contexta. -4pothecia in capitulis, theciis immersis sine paratheciis;
paraphyses tennes ; asci pachydermei ; ascosporne ellipsoideae, polari-biloculares.
Thallns fruticulose, prostrate ; cortex of longitudinal, conglutinate hyphae ; algae protococcoid;
medulla of loosely woven hyphae. Apothecia in heads without algae, thecia immersed,
numerous, without parathecia; paraphyses slender; asci relatively thick-walled, only the tip thinning
at maturity ; ascospores ellipsoidal, hyaline, polari-bilocular.