LICHENS AND LICHEN. PARASITES

46 B.A.N.Z. ANTARCTIC RESEARCH EXPEDITION
where it thins and merges with the medulla, even including an occasional algal cell; periphyses
not seen as the upper portion is badly gelified in the specimens seen and invaded by Sclerococcus ( ?) ;
paraphyses slender, vertical, little branched, forming a dense, somewhat gelified palisade betweeii
the long, cylindric, 8-spored asci; ascospores hyaline, muriform with about 3 prominent trans-
verse septa and 5-6 longitudinal ones in the middle cells, 16-25 X 7-lop.
Growing on rocks with T7errzicaria obfuscata, Lecidea sublygomnza, Rhizocarpon kcrguelcnsc,
Aspicilia disjunguenda, A. entlochlora, Lecanora atrocae.sia and Rinodina aspicilina,.
As the ascospore matures, apparently the walls finally gelify between the individual spore
cells, as many groups of small oblong cells are seen in the gel of the ostiole, the groups having
the general shape of the spores that produced them. As one traces these cell groups lower in the
perithecium along the row of the now gelified ascns, the arraiigement is more regular, the nunl-
bcr of cells coinposing the group fewer, until at the base of the perithecium, typical muriform
spores are seen. Such separation of cells of muriform spores with subsequent division of the
spore cells has been observed in other groups of fungi but is not commonly reported in the
lichens.
The collection from Kerguelen which we have provisionally referred here is much more geli-
fietl and parasitized, but such structures as are still discernible, agree with corresponding struc-
tures in the material from Heard Island upon which the above description was based. The Ker-
guelen material is from the type locality of this species.
Kerguelen : Observatory Bay, B.A.N.Z.A.R.E. B192-4.
IIearcl Islalid : Atlas Cove and Corinthian Bay, B.A.N.Z.A.R.E. B140-6.
MICROQLAENA MAWSONI Dodge, sp. nov.
Type: IZerguelen, near Port Jeanne dlArc, 1,600 ft., B.A.N.Z.A.R.E. R201.
Thallns tenuissimns, indeterminatus, contin uus, gelifactus madefactus, obscure oblivaceus ;
ecorticatus; algae palmelloideae, cellulis 4-5p diametro; perithecia dimidiata, involncrello carbonacea,
40-75p crassitudine ad ostiolum circa 20p crassitndine tennescente, circa 250p ab ostiolo
radiante ; ostiolo papillato 20p altitudine, 90p diametro basi ; murus perithecialis 20p crassitndine
I~yphis periclinalibns, tenuibus, hyalinis; periphyses desnnt ; hypothecium a mnro peritheciali no11
distiticlum ; thecium basale, non in lateribns dispositurn ; paraphyses tenues, ramosae, persistentes
ail ostiolum attingentes; asci cylindrici, centro recti, ad latera curvati, circiter 130 X 20p
cvanescentes; ascosporae octonae, snbmonostichae, hyalinae, muriformes, circiter, transversim
7-septatae et longitudinaliter 4-5-septatae(. 3640 X 12-14p.
Thallus very thin, indeterminate, continuous, gelatinous when moist, dark olive ; ecorticate :
algae palmelloid, 4-5p in diameter near the perithecia (scrapings of the thallus show algal cells
more variable in size with occasional filaments of Rivzilam'n) ; perithecia dimidiate, covered by a
carbonaceous involucrellum about 40-75p thick, thinning rapidly to about 20p thick around the
ostiole and extending about 250p from it: ostiole piercing a papilla about 20p tall and about 90p
ill diameter at the base; perithecial wall 20p thick of slender periclinal hyaline hyphae; peri-
~hys~s absent ; hypothecium not differentiated from the perithecial wall ; thecium not differentiated
as a distinct layer and not extending up the sides of the perithecium; paraphyses slender,
branched, persistent, extending to the ostiole ; asci cylindrical, straight in the centre, curved next
the sicle walls, about 130 X 20p, evanescent, 8-spored ascospores subuniseriate, hyaline, muriform
with about 7 transverse septa and 4-5 longitudinal septa while still in the ascus, but continuing
to divide repeatedly after the ascus wall disappears, 36-40 X 12-14p.
. On rock with Steincra TTcrfhii.
This species differs from Microglaena kergzielcrm (Nyl.) Zahlbr. in much larger spores.
Kerguelen : above Port Jeanne d 'Arc, 1,60 0 ft., E. A.N.Z.A.R.E. B201.