LICHENS AND LICHEN. PARASITES

DODGE-LICHENS AND LICHEN PABABITES I87
of the dark brown, coarse medullary hyphae (not at the junction with the finer, white medullary
hyphae as in M. pertusa) ; soredia in the centre of the thallus, from circul'ar, subcerebriform
soralia which brealr up into coarsely granular soredia and are more or less confluent (not at
the tips as in M. pertusa) ; lower surface antique brown at the margin, darker towards the centre,
variously wrinkled and verrucose, smooth, without rhizinae ; upper cortex 25-35p thick, fastigiate,
of very thick-walled hyphae about 4p in diameter, with spherical protoplasts about 2p in diameter,
decomposed above; algal layer about 35p thick, of loosely arranged, solitary protococcoid cells,
11-15p in diameter, more or less continuous, with occasional small colonies about 20p in diameter,
composed of closely packed young cells 5-6p in diameter, separated by strands of medullary
hyphae (the future soredia?) ; upper medulla 50-60p thick, compact, hyaline, of thick-walled,
longitudinal hyphae:%-6p in diameter, appearing almost pseudoparenchymatous above, somewhat
looser below; lower \ medulla of dark brown hyphae, very loosely woven, 7-8p in diameter,
splitting into two layers, each 75-100p thick, thus lining the central cavity (often with outgrowths
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at the septa suggesting the clamp connections of the Basidiomycetes) ; lower cortex a palisade of
the lower medullary hyphae, cells rounded, about 8p in diameter, giving a loose pseudoparen-
, chyma, ,dark brown to black in thicker sections. Apothecia and spermogonia not seen.
At first sight this might be taken for M. pertusa (Schrank) Schaer, but the soredia are borne
on the older portions, not the growing tips, the rupture to form the cavities of the inflated lobes is
in the centre of the lower medulla, not at its junction with the upper medulla, all dimensions are
much larger, and the upper cortex is hyaline and decomposing.
Growing over mosses, Macquarie Island. Probably the reports of Parmelia pertusa from
Campbell Island by Nylander and of P. diatrypu from the Auckland Islands by J. D. Hooker and
Taylor belong hme.
Macquarie Island, Featherbed Flat, Sta. 81a, B.A.N.Z.A.R.E. 531-21, 531-22; north end of
Island, Sta. 81, B.A.N.Z.A.R.E. 540-12, 540-13.
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Parmelia ~ch., Meth. Lich., 153; 1803.
PARMELIA Ach.
Imbricariu Ach., K. Vetenslr. Akad. Nya Handl., 15, 250; 1794: Michaux, F1. Bor.-Am., 2, 322;
1803.
Physcia S. F. Gray, Nat. Arr. Brit. Pl., 1, 455 ; 1821 non Schreber, 1791.
Type : P. sazatilis (L.) Ach.
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Thallus foliose, appressed or ascending, laciniate, with rounded or linear lobes, often imbricate ;
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' .i pipper surface often sorediose or isidiose, lower surface either lighter or darker than the upper,
usually covered with rhizinae except at the margins (rhizinae absent in subgenus Hypogyntnia) ;
upper cortex of vertical hyphae, lower cortex usually similar (but of longitudinal hyphae in the
Physcioideae) ; medulla of loosely woven periclinal hyphae ; algae protococcoid ; apothecium on
the upper surface, never marginal, sessile or short stipitate, disc concave or flat, chestnut brown,
amphithecium prominent, hypothecium hyaline with algae below; paraphyses imbedded in a gel,
usually branched and septate, clavate or pointed at the tips; asci clavate, usually 8-spored,
ascospores hyaline and unicellular; spermogonia immersed in the surface of the thallus or
amphithecium, spherical or pyriform, opening by black ostioles, wall black or dark brown above,
light brown or hialine below, spermatiophores simple or branched; spermatia cylindric or fnsiform,
often slightly constricted in the middle.
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