LICHENS AND LICHEN. PARASITES

DODGE-LICHEN8 AND LICHEN PARABITEB. 195
Thallus not articulate, surface smooth, usually pruinose and very pale green
(drying yellow to orange, black maculate in species from Kerguelia)
Laevigatae
Thallus long, pendulous ; not in our area . . . . ~kabilcs
Thallus short, erect ; algae Trentepohlia . . . . Roccellinae
Alectoria Ach., Lichenogr. TJniv., 120 ; 1810.
ALEC~RIA Ach.
Type : A. sarmentosa Ach.
Thallus pendulo;s,Qrostrate or somewhat erect, attached by a hapteron, round or somewhat
flattened, seldom angular, radiate ; cortex horny, of longitudinal conglutinate hyphae ; algae protococcoid
; medulla of longitudinal hyphae ; centre hollow or arachnoid ; pseudocyphellae or soredia
frequent. Apothecia lateral on short br~iihes ; amphithecium usually well developed, margin
naked or ciliate, sessile or substipitate; disc brown to black ; hypothecium hyaline, resting on the
algal layer ; paraphyses branched and ansstomosing ; asci 48-spored ; ascospores unicellular,
ellipsoid, hyaline or brown, thin-walled. Spermogonia immersed in small warts, spermatiophores
little branched, septate; spermatia short, straight, somewhat thickened at the ends.
A single species in the section Byropogonl is present in our material.
ALECTORIA CONGESTA (Zahlbr.) Dodge, comb. nov.
Pnrmelia pubescens v. cmgesta Zahlbr., Dentsche Sudpolar Exp., 8,52 ; 1906.
Type : Kaiser Wilhelm I1 Land, Gaussberg, Vanhoffen, on basalt, (Deutsche Sudpolar Exp.).
Thallus forming dense, flat tufts up to 3 cm. ip diameter and 5 mm. high; more or less
recumbent below, the larger filaments up to 0-3 mm. in diameter, slightly flattened [excessive
pressure in drying?], buffy citrine to Saccardo's olive, repeatedly dichotomous, lower internodes
up to 0-7 y. long, successively shorter and darker, becoming trichotomous and thus pinnate,
ultimate brdnches obtuse, up to 250~ long and 50rin diameter, coal black, dull, deep olive under tHe
high power of the microscope; cortex about 20,~ thick, of longitudinal hyphae with moderately ,
thickened walls, the outermost hyphae with dark brown walls; algal layer filling the rest of the
filament, cells protococcoid, ellipsoidal, about 1 5 in ~ diameter, crowded next the cortex, more
loosely spaced with air-spaces and more medullary hyphae toward the centre.
In the growing tips, the algae are closely packed in rows and appeal almost filamentous,
$th a very thin cortex. Colonies of bacteria appear in many of the axils, perhaps representing
&n Azotobacter symbiosis such as Cengia Sambo (Atti Soc. Ital. Sci. Nat. Mus. Civico Stor. Nat.
, Milano, 62, 226-238 ; 1923 : 64, 191-195 ; 1926) ieported in the Italian Alps and we have suggested
in Antarctica (Dodge & Baker, Ann. Mo. Bot. Gal d., 25, 522 ; 1938). Except for a very small,
depauperate specimen on granite, our material has been detached from the rocks, hence the sub-
stratum is uncertain.
On rocks with Urnbilicnria rugosa, Lecanora exsldans, L. Johnsfmi, L. Ma.wsoni, BuelIia
dendritica and B. muscicola.
King George V Land : Cape Denison, A.A.E. 50-2, 51, 92, 102-3, 103-3, 104-3, 131, 146, 149,
157, 177, 178 ; Madigan Nunatak, 2,400 ft., 30 miles east of winter quarters, C. F. Lassron, A.A.E.
25-6.
Queen Mary Land: Possession Nunatak, C. T. Harrisson, A.A.E. 36; Hippo Nmatak, C. T.
Harrison, A.A.E. 65-2. f
MacRobertson Land : Cape Bruce, B.A.N.Z.A.R.E. B108-9.