LICHENS AND LICHEN. PARASITES

DODGE--LICHENS AN11 YJICHEN PARASITES 237
MAWWNIA HARRISSONI Dodge, sp. nov.
Type: Queen Mary Land, Possession Nunatak, C. T. Harrisson, A.A.E. 53.
Thallus prostratus, niger, dichotome ramosus, ramis acl 75p diametro, racliantihns; cortex
hyphis longitudinalibus, conglutinatis, obscure fuligineis, 5p dia1net1.o; algae protococcoicleae,
7-8p diametro, coloiliis parvis ; medulla hyphis laxe contextis, 6-7p diametro, crystallis inspersis.
Capitula apotheciorum ad 200p diametro, discis convexiusculis, nigris ; parathecium deest ; theciis
immersis, 75p diametro, 50p altitudine; paraphyses tenues, semel bisve super ascos dichotome
ramosae, apicibus clavatis, nigris, pachydermeis, ca. 4r diametro ; aqci clavati, apicibus incrassatis,
protoplastis conicis, dein magis ellipsoidei, 25 X 15p, pachydermei, sed apicibus tennescentibus ;
ascosporae octonae, distichae, late ellipsoideae vel ovoideae, polari-biloculares, 8-9 X 5.5-6p,
prntoplastis late conicis 3p altitudine, isthmis tennibus jnnctis.
Thallus prostrate, black, branching clichotomous, larger branches up to 75p in diameter,
radiating; cortex of longitudinal, conglutinate branched, dark fuliginous hypha'e about 5r in
diameter ; algal cells scattered, protococcoid, 7- 6r in diameter ; producing apotheciiform assimilative
aeroles (perhaps soralia) up to 200r in diameter, upper surface (corresponding to the
disc of an apothecium) white or slightly greenish, cortex eroded, except for a few somewhat
moniliform fragments of hyphae, algal cells grouped in small colonies, mostly rather deep in
the medulla ; medulla of loosely uroven hyphae &7p in diameter, with abundant hyaline crystals
and larger hyaline rock crystals near the surface, also small coloilies of bacteria.
Apothecial heads spherical, up to 200~ in diameter, black, similar in structure to the
assimilative areoles but without algae; with minute thecia immersed in the heads, disc
concolourous and of the same curvature as the adjacent sterile tissue (hence invisible except i11
sections) ; no parathecium; thecium about 75p in diameter and 50p tall; paraphyses slender, once
or twice branched above the asci, tips clarate, black, thick-walled, about 4p in diameter; asci
clavate at first with a very thick wall and tip, protoplast conical above, becoming almost
ellipsoid, 25 X 15r, wall remaining relatively thick, but tip thinning, 8-spored; ascospores
distichous, broadly ellipsoidal to ovoid, polari-bilocular, 8-9 X 5.5-6p, protoplasts somewhat
broadly conic, about 3p tall, connected by a very slender isthmus.
This species is easily mistaken for a young state of Buellia flavoplana Darb. or a small
Alectoria, except for the peculiar structure of the apothecial heads and ascospores. The
anatomy of the thallus corresponds closely with that of Alectorin. and in a general way with
that of Teloschktes, but the apothecia are very distinct from either.
Queen Mary Land, Possessioil Nunatak, 'c. T. Harrisson, A.A.E. 53.
POLYCAULIQNA Hue.
. Polyca?ilim Hue, Exp. Antarct. Franc. Sci. Nat. Lich., 8; 1908.
Pkodium sect. Thantn0m.a Tuck. Gen. Lich., 107; 1872.
Type: P. rqalis (Vainio) Hue. The type of Placodiunt sect. Thanl.nonta is P. coralloidcs
Tuck.
Thallus fruticulose, yellow to chestnut, ercct or decumbent at the periphery, dichotomous
or irregularly branched, branches often short and nodulose; cortex completely surrounding the
thallus, duplex the outer zone, amorphous from hyphae perpendiclilar to the axis, the inner more
branched and much more slender; algae protococcoid; medulla of hyphae parallel to the axis,
closely conglutinate. Apothecia terminal on the main axis or branches, constricted at the base,
concave then flattened, disc orange; amphithecium and parathecium well developed; hypothecium