GAPING FUNGI— HYSTERIACEAE 223 



which may be referred to in their order. Hyalosporae, in which 

 the sporidia are continuous and hyaline, includes the two 

 genera Schizothyrium and Henriquesia. In the former the 

 sporidia are minute, and in the latter large ; but the habit is 

 also different, the species being small and superficial, mostly 

 occurring on leaves and herbaceous stems in the former ; and 

 erumpent, Hysterium-like, and arboricolous in the latter. The 

 analogue of Schizothyrium, in the Sphaeropsideae, is Labrella, 

 which resembles Schizothyrium in habit and appearance, but 

 the perithecia are stylosporous, and in some species may prove 

 to be genetically related. The Phaeosporae differ from Hyalo- 

 sporae in the continuous sporidia being distinctly coloured. The 

 only genus is Farlowia, in which the habit is distinctly that of 

 Hysterium, to which the species were formerly referred, and 

 the perithecia carbonaceous. The British representatives are 

 the Hysterium Carmichaelianum of Berkeley and the Hysterium 

 repanalum of Bloxam, which hitherto are the only species 

 known. The Hyalodidymae are characterised by hyaline uni- 

 septate sporidia, and include four genera, in one of which, 

 Aulographum, the perithecia are membranaceous, already 

 alluded to ; in Glonium and Actidium the perithecia are 

 carbonaceous, in the former being simple or branched, and in 

 the latter stellate. There is considerable difference in the 

 habit of the different species of Glonium, some being linear 

 and scattered, whilst others are densely agglomerated in compact 

 heaps. There is still a fourth genus, that of Angelinia, in 

 which the perithecia are at first somewhat fleshy, and open, 

 exposing the disc, so that it resembles Cenangium. The colour 

 of the excipulum being reddish, is also abnormal, and the single 

 species is rather a doubtful member of the Hysteriaceae. The 

 Phaeodidymae, with coloured uniseptate sporidia, includes the 

 two genera Tryblidmm and Lembosia. In the former the 

 perithecia are gaping, with swollen lips, exposing the hymenium 

 more than usual in this subfamily. Its nearest ally is Try- 

 Uidiella, in the Pheophragmiae section, and the two supposed 

 genera differ only in the latter having sporidia with more than 

 one septum, whilst in the former they are only uniseptate, for 

 which reason we are disposed to regard the distinctions as only of 

 subgeneric value. Lembosia has also been referred to already 



