264 INTRODUCTION- TO THE STUDY OF FUNGI 



Hypocenia the sporules are fusoid and pale brown. Levieuxia 

 is a South African genus, containing a single species, with a 

 stipitate perithecium, which is fissured at the apex when 

 mature. The only genus with hairy perithecia is Ghaetomella, 

 which is the analogue of Ghaetomium, but deficient in asci. 

 The residue of the section consists of genera in which the 

 perithecia are compound or caespitose. Haplosporella is, in 

 fact, a caespitose Sphaeropsis, the perithecia being aggregated 

 in dense erumpent pustules, resembling those of some species 

 of Botryosphaeria. Weinmannodora has a stroma which is 

 hemispherical and carbonaceous, with radiating fertile cells, 

 containing globose dark sporules. Cytoplea consists of a single 

 species, in which the stroma is at first pulvinate, then con- 

 fluent and effused. Practically the entire section is repre- 

 sented in Europe by Sphaeropsis and Coniothyrium, with 

 smooth perithecia ; and Chaetomella, with setose perithecia ; 

 and in the compound genera by Haplosporella. 



The Phaeodidymae is also a small section, with uniseptate 

 coloured sporules, and is, in fact, entirely made up of species 

 which entered into the old genus Diplodia, as recognised by 

 Fries. Thus Diplodia, as limited, contains species with a 

 smooth perithecium, and coloured sporules, not having a mucous 

 envelope ; Macrodiplodia, with similar smooth perithecia, but 

 coloured sporules having a mucous envelope, as in the sporidia 

 of Massaria; Chaetodiplodia, with hairy perithecia, and 

 sporules as in Diplodia. The remaining genus with simple 

 perithecia is Diplodiella, in which the perithecia are almost 

 superficial, and flourish on decaying wood. The single com- 

 posite genus is JBotryodiplodia, with the perithecia densely 

 aggregated in erumpent pustules as in Haplosporella. 



The section Hyalodidymae is characterised by hyaline 

 uniseptate sporules. Two genera correspond to Phyllosticta in 

 Hyalosporae, in that the species are mostly parasitic on living 

 leaves, collected on discoloured spots. In Ascochyta the sporules 

 are simply uniseptate, but in Robillarda the sporules are uni- 

 septate and crested at the apex with long setae, resembling in 

 this respect the genus Pestalozzia. In three other genera the 

 smooth perithecia are scattered and not seated on discoloured 

 spots. Actinonema has the perithecia seated upon a radiating 



