LICHENS AND LICHEN. PARASITES

DODGE-LICHENS AND LICHEN PARASITES 99
Apothecia crowded on the tops of the areoles, constricted beneath, black, shining, mostly
about 0.5 mm. in diameter (proliferating ones up to 1 mm.), exciple prominent, disc remaining
flat (or concentrically gyrose from proliferation of new small apothecia from the disc of the old
one) ; parathecium carbonaceous, 150~ thick, of isodiamctric, thick-walled, dark brown cells,
about qLr in diameter; hypothezium inconspicnnus, about 2OP thick, of very slender subvertical
hyphae, epithecium greenish-blue when first sectioned, fading on standing; thecium 25-3OP tall;
paraphyses, slender, wall. gelified, once branched above the asci, tips clarate, black, about 2 .5~ in
diameter; asci broadly clavate, 26 X 10-12p, wall aboiit 4~ thick, protoplast papillatc at first,
becoming clavate; ascospores unicellular, hyaline, long cllipaoidal with a broad sheath,
7-8 X 2.5-3~ (including sheath).
This species is intermediate between L. Coreyi which it resembles in several microscopic
characters, and L. Blackblrrni and L. rwpicida which it resembles in habit.
Icing George V hand, Madigan Nunatak. 2,400 ft., 30 miles east of Winter Quarters, C. F.
Laseron, A.A.E. 41-1.
LECIDEA BLACKBURNI Dodge & Baker
Lecidea Blackbllrnl Dodge & Baker, Ann. Mo. Bot. Gard., 25, 540; 1939.
Type : South Victoria Land. Queen Maud Mts., Mt. Scudder, 86" 03' S., 150" 40' W., Q. A.
Blackburn, R. S. Russell, Jnr. & S. D. L. Paine QM-6 (2).
Non-assimilative portion a few black strands composed of dark, irrrgular hyphae, clendritic,
extending over areas 4-3 mm. in *diameter; assimilative portion up to 0.75 mm., irregularly
areolate, soft to gelified when moist, pale olive buff to citrine drab ; col-tes 10-18p thick, of several
layers of small, fastigiate cells, light to dark-brown in the outer layers, the whole covered by n
layer of dead cells, up to 2OP thick; algal layer 90-10OP thick, cells up to 1 5 in ~ diameter, closely
packed; medulla up to 850~ thick, of slender hyphae 1-1.5~r in diameter, reticulately arrangecl,
more compactly so about the algae; lower cortex absent.
Apothecia up to 0.5 mm. in diameter, irregularly elliptical to circular in outline, more or less
flattened with a distinct margin, sessile, closely crowded or scattered, black, somewhat shining;
parathecium consisting of a few cells merging with the marginal cortex which is well developed,
up to 2 5 thick, ~ of large, isodiametric cells, carbonaceous, fusing with the epithecium above and
the thalline cortex below; hypothecium 60-70r, thick, fuscous brown slightly thinning toward the
margin, of thick-walled pseudoparenchyma; thezium 50-9OP tall; paraphyses lp in diameter,
heads up to 3~r, darkened, without incrustations, uiibranched or branched near the tips, epithecium
8-12~, thick, carbonaceous, rough, turning green with K; asci (37-) 52-60 X 9-1lP, 8-spored,
long, slender clavate, expanding gradually from the attenuate base (not abruptly as in L. cancriformis)
; ascospores 6 5-8.5 X 2-2. Sp, ellipsoidal, unicellular.
A few weathered thalli seem to belong here although the spores are somewhat larger. The .
above description was based on the type.
King George V Ln~ld: Madigan Nuntak, 2,400 ft., C. I?. Laseron A.A.E. 25-1.
LECIDEA CANCRIFORMIS Dodge & Baker
Lecidea cancriformis Dodge b Baker, Ann. Mo. Bot. Gard., 25, 539 ; 1938.
Type: South Victoria Land, Queen Maud Mts., Mt. Scudder 86" 03'S., 150" 40' W., Q. A.
Blackburn, R. S. Russell, Jnr. & S. D. L. Paine QM-6 (2).
Thallus areolate, 11p to 0.5 mm. wicle, usually in long strands bearing several apothecia,
greyish white, gelified when moist, irregular in shape, more or less verrncose, small and inconspicuous
in comparison with the apothecia ; upper cortex 2-8~ thick, brownish, of small fastigiate