AN INVESTIGATION OF THE SOOTY MOULDS OF NEW SOUTH WALES. V. THE SPECIES OF THE CHAETOTHYRIEAE. By LILIAN Feaser, M.Sc, Linnean Macleay Fellow of the Society in Botany. (Thii'ty-nine Text-figures.) [Read 31st July, 1935.] The members of the subsection Chaetothyrieae of the family Capnodiaceae are much less conspicuous than those of the Eucapnodieae. They never form a thick sooty covering on the leaves of plants. Their mycelium is characteris-tically very thin and vsridely effused. The fructifications are scattered irregularly. No fungi belonging to this group have hitherto been recorded for New South Wales, and only one, Chaetothyrium {Meliola, Ziikalia) loganiense (Sacc.) Th. and Syd., has been recorded for Queensland. The species here described belong to the genera AWialoderma and Chaetotliyrium. In referring species to the genus Chaetothyrium the writer has followed the emendations of Petrak (1929). Petrak considers that the genera Chaetothyrium, Phaeosaccardinula and TreuMomyces, which are separated by Theissen and Sydow (1917) by the presence or absence of setae and the nature of the septation of the ascospores, are not generically distinct. He points out that intergrading forms between types with setae and those lacking setae may occur in the one species. Boedijn (1931) has come to a similar conclusion. In Theissen and Sydow's key to the Chaetothyrieae the differences between the genera Aithalodervia and Chaetothyrium are given as follows: Spores 4 to many celled, colourless. X. Setae present around the ostiole only, mycelium smooth .... Aithaloderma XX. Setae present on the mycelium or perithecium Chaetothyrium Von Hoehnel (1918) has come to the conclusion that the presence of setae round the ostiole in Aithaloderma is not necessarily a generic character. He quotes cases in which they are absent altogether from some fructifications and present on others of the same species. Since, therefore, the presence of setae on mycelium or fructification is not a valid feature for the separation of genera, the key of Theissen and Sydow breaks down. The two genera Aithaloderma and Chaetothyrium are admittedly distinct, but must therefore be separated on different features. It is suggested that the following may serve as a basis for separation: Aithaloderma. — ^Ascostroma conical, widest at the base, usually about 100/tc in diameter. The wall pseudoparenchymatous. The apical pore often surrounded by divergent dark setae. Asci as numerous as in Capnodium. Pycnidium conical, similar to the ascostromata. Mycelium without setae, dark coloured, usually fairly stout. (Various types of pycnidia have been described as belonging to species of Aithaloderma, but it is probable that elongated forms such as Microzyphium belong to other fungi.)
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