LICHENS AND LICHEN. PARASITES

78 D.A.N.Z. ANTARCTIC RESEARCH EXPEDITION
once dichotomous above the asci, tips not enlarged; asci cylindric, about 90 X 15~, tip not
thickened; ascospores unicellular, long ellipsoidal, about 15 X 6p while still in the ascus, with a
broad sheath about 2p thick, thinning when free and becoming 18 X 7p (sheath included in
both measurements).
Spermogonia oblately sphaeroidal, about 250~ in diameter, 150p tall, brown; wall formed by
the outgrowth of cortical hyphae which become slendel. and periclinal and increasiiigly brown
toward the top, 20p thick; spermatiophores 1p or less in diameter, about 25p long, branched at
the base; spermatia curved, somewhat crescent shaped, 6-8 X lp.
The structure of the thallus is clearly that of Psoronzn as is also the structure of the
apothecium with the teiidency of the algae to disappear from the older parts of the amphitliecium.
Exterrially the spermogonia are suggestive of Cetraria and Aspidelia, being marginal
in elevated structures, while the spermatiophores and spermatia resemble those of Lccunora,
rather than the type usual in Psormm. The habit of the apothecia resembles that of the Parmeliaceae.
Macquarie Island: Featherbed Flat, B.A.N.Z.A.R.E. R3314, B531-3.
THELIDEA Hue.
Thelidea Hue, Bull. Soc. Bot. France 48: lxi. 1901.
Type : T. corrzigata Hue.
Thallus erect, foliose, upper surface corticate, of more or less erect, septate hyphae; algae
Palmellaceae 9; ecorticate below. Apothecia biatorine; ascospores hyaline, 2-celled.
The systematic position of this genus is uncertain. Hue made a separate tribe, the Thelideae ;
Bahlbrwkner treats it with the Pannariaceae, but of uncertain position. Our material adds
nothing to clear up the uncertainty. The type is knoiim only from Campbell Island.
Thallus more or less erect, about 8 mm. tall and 10 mm. broad, somewhat flabellate, margin
variously lacerate and snbdigitate, olive yellow, surface minutely granulate and slightly corru-
gate; upper cortex about 2Sp thick, fastigiate, of coarse, occasionally branched, highly gelified
hyphae, lumen less than lp in diameter; algal layer about 35p thick, of hemispheric colonies,
separated by strands lop thick of medullary hyphae, cells spherical, 7-8p in diameter, palmel-
loid; medulla 110-120p thick, loosely woven, of hyaline, very thick-walled hyphae, 6p in diameter,
lumen lp or less, slightly more closely woven below but not developing a lower cortex; provided
with a rooting base. Reproductive structures not seen.
The anatomy of the thallus is somewhat intermediate between that of Psoroma versicolor
(Hook. f. & Tayl.) Miill.-Arg. and Thelidea corrugata Hue. In the cortex, the hyphae are less
branched and anastomosed than in the former, but are not moniliform as in the latter. The iden-
tification of the algae is uncertain. Hue referred the yellowish green algae of Thelidea corru-
gata to Palmella, but Bornet was uncertain, while those of Psoroma are protococcoid. In our
material, the algae are quite yellowish, but occur as single cells with a relatively thick wall.
The chloroplast is quite unfamiliar to me, but rese'mbles those figured for the Palmellaceae more
than those of the Protococcaceae. In habit our plant might be taken for a small, yellowish
Cetraria until it is sectioned.
Growing among mosses.
Macquarie Island : north end, B.A.N.B.A.R.E. R540-5.