FILICALES. Cyathea dealbata: Auckland, Mountain Road, Waitakere Ranges, 300 m, type collection, P.D.D. herbarium, No. 17426.

Hymenophore annual, membranous, adherent, effused forming irregular areas 7-9 x 3-4 cm; hymenial surface straw colour, drying pallid ochre, velutinate, deeply areolately creviced; margin thinning out, fibrillose, cream, adherent. Context cream, 90-160 µ thick, basal layer of mainly parallel hyphae, intermediate layer a dense zone of erect hyphae soon partly collapsed and cemented; generative hyphae 2-2.5 µ diameter, walls 0.1 µ thick, with clamp connections. Cystidia irregular in shape and size, subulate with radicate bases and acuminate sometimes bifid apices, projecting to 30 µ, often geniculated, basal roots one or several, sometimes freely branched and almost dendriform, 55-75 x 6-10 µ, lumena capillary, walls smooth, enmeshed in hyphal sheaths. Hymenial layer to 20 µ deep, a scanty palisade of basidia, paraphyses, and cystidia. Basidia cylindrical or cucurbitiform with slightly inflated bases, 12-16 x 5-6 µ, bearing 4 spores; sterigmata arcuate, slender, to 7 µ long. Paraphyses cylindrical or obovate, 12-15 x 3.5-4 µ. Spores allantoid, with acuminate ends, 6-8 x 2-2.5 µ, walls smooth, hyaline, 0.1 µ thick.

TYPE LOCALITY: Waitakere Ranges, Auckland, New Zealand.
DISTRIBUTION: New Zealand.

HABITAT: Effused on trunks of tree ferns.

Hymenophorum membranaceum, adnatum, effusum; superficie straminea, pallide ochracea siccante, velutinata, alte areolato rimosa. Hyphae generatoriae fibulatae, 2-2.5 µ diam. Cystidia subulata, basis radicatis, saepe geniculata, 55-75 x 6-10 µ, lumenibus capillatis, in vaginis hypharum implicatis. Basidia cylindricalia, 12-16 x 5-7 µ, 4 sporis. Sporae allantoides, 6-8 x 2-2.5 µ, parietibus levibus, hyalinis. On dead pendent stipes of Cyathea dealbata, Waitakere Ranges, Auckland, N.Z.

Cystidia stain deeply with aniline blue, but are not amyloid. They are irregular both in size and shape and crowded into irregular rows in the hymenial layer and context. Most are subulate, some bifid near apices, others bear a lateral branch about midway, others again are flexuous or the apical part is geniculated. Roots vary in numbers and shape, some being freely branched so that they appear almost dendriform. When branched portions are detached accidentally in preparing sections they appear like dendriform structures among the context hyphae. The habitat is unusual, the collection being taken from hard black residual bases of dead stipes forming the exterior of a tree fern trunk.