On dead bark and wood of (1) Brachyglottis repanda, Auckland, Waiuku, Feb 1953, J. M. Dingley, 12479; (2) Coprosma arborea, Henderson, Sep 1953, J. M. D., 24499; (3) C. foetidissima. Taranaki, Mt Egmont, Feb 1952, G. H. Cunningham, 24500; (4) Dacrydium cupressinum, Auckland, Huia, Nov 1948, J. M. D., 24504; (5) Eucalyptus sp., Campbell's Bay, Sep 1955, E. E. Chamberlain, 24505; (6) Eugenia maire, Henderson Valley, May 1952, S. D. Baker, 24502; (7) Leptospermum ericoides, Titirangi, May 1965, R.F.R. McN„ 24603; (8) L. scoparium, Wellington, Mt Tongariro, Dee 1955, G. H. C., 24495;
(9) Leucopogon fasciculatus, Auckland, Mt Te Aroha, Nov 1946, G. H. C., 4776;
(10) Melicytus ramiflorus, Hawkes Bay, Waipatiki Beach, Nov 1955, J. M. D., 24495.

Fructifications arid-waxy, resupinate, thin, effused, indeterminate, forming irregular areas to 15 cm in longest dimension, pruinose. white to creamy white when fresh, changing little on drying; margins concolorous. adnate. In section to 100 µm, thick, consisting of basal layer and hymenium; granular calcareous material scattered abundantly throughout fructification. Basal layer thin, composed of compact, interwoven, indistinct hyphae lying parallel with substratum, clamp connections present. Hymenium composed of dikaryophyses and basidia; dikaryophyses extremely variable in shape, typically nodulose, irregularly branched apically, 1.5-3 µm diam. intergrading through simple, cylindrical dikaryophyses to clavate, gloeocystidia-like structures to 11 µm diam.; probasidia subglobose to obovate, with basal clamp connections, formed in groups, 11.4-15.6 x 8-12.5 µm, becoming 2-celled by longitudinal septa or longitudinally cruciate-septate: sterigmata cylindrical, to 30 x 2.5-3 µm. Basidiospores curved-cylindrical to allantoid, hyaline, apiculate, 11-15.5 x 3.7-4.5-(6) µm. Germination by repetition.

Angiosperm and occasionally gymnosperm bark and wood.

Wells. Lloydia 20: 47, f. 1. 1957; Olive, Bull. Torrey bot. Club 85: 6, f. 1F. 25, f. 10. 1958.

The degree of variability in the shape of dikaryophyses appears to be a characteristic feature of Sebacina mucedinea. In New Zealand collections there is a gradation from irregularly branched dikaryophyses to stout, clavate, gloeocystidia-like structures with hyaline contents. Similar variation was observed in Tahitian material by Olive (1958, p. 23), but the clavate structures were interpreted by him as gloeocystidia. Olive also noted similar structures in the type of S. mucedinea and for this reason placed the species in section Bourdotia.
Neither Martin (1944, p. 69) nor Wells (1957, p. 48) mentioned the presence of gloeocystidia-like structures in S. mucedinea. In a later publication. Wells (1959, p. 560) excluded the species from the genus Bourdotia on the grounds that these structures were not homologous with the gloeocystidia possessing yellow, granular contents found in Bourdotia. In addition, Wells commented that basidium development was not typical of Bourdotia. On the basis of New Zealand material I am inclined to agree with Wells, for in all collections examined the gloeocystidia-like structures lack yellow or brown, granular contents, although their walls may be tinted yellow. However, any disagreement over the interpretation of these structures only serves to support Olive's contention that it is undesirable to use the presence or absence of a single character as a basis for generic separation.
Sebacina mucedinea may be distinguished by the thin, white, mucedinoid fructifications, variable dikaryophyses, and curved-cylindrical to allantoid spores. It is a common species in New Zealand.

Pululahuana, Ecuador.