268 INTRODUCTION TO THE STUDY OF FUNGI 



three genera and three species, has been placed in proximity 

 to the Nectrioideae, although not quite conforming thereto, on 

 account of their approach to a cup-shaped receptacle, so that 

 their position can only be regarded as provisional. Hysteromyxa 

 combines the habit of a Mysterium with the fruit of a 

 Myxomycete. Patellina with the habit of a Patettaria has 

 stylosporous fruit. And Cyphina has the appearance of an 

 Excipula, but is bright coloured and garnished with white 

 hairs, so as to offer an analogy to Volutella. All of these 

 require fuller investigation, and none are European. 



The family Zeptostromaceae diverges from the previous 

 families in losing much of the Sphaeria-like habit, and 

 approaching that of some of the Hysteriaceae, with occasional 

 suggestions of Phacidiaceae. The perithecia are more or less 

 distinctly dimidiate, or scutiform, with or without an ostiolum, 

 or fissured longitudinally, either membranaceous or carbonace- 

 ous, black, and either erumpent or superficial. Under the 

 carpological arrangement, the Hyalosporae are again the most 

 numerous, and resolve themselves into two subdivisions, in one 

 of which, although the perithecia are destitute of a definite 

 mouth, they dehisce in diverse ways, but not with a longitu- 

 dinal fissure. In the other subdivision the perithecia split 

 longitudinally after the manner of the Hysteriaceae. Zeptothy- 

 rium is the chief genus in the first subdivision, 

 with a dimidiate and shield-like perithecium, 

 which does not split by a longitudinal fissure, but 

 soon cracks all round and falls away (Fig. 123). 

 ^ *~\ Some of the species are believed to be the stylo- 

 ^=2=^^, spores of certain species of Goccomyces. The genus 

 ^"^ -=^ Piggotia has an irregular depressed perithecium 

 Fig. 123.— Lep- w hi c h d oes no t f a u a wav. Melasmia is allied, 



tothynum. * 



but in this genus the perithecia are innate in a 

 black effused stroma, growing on fading leaves. The species 

 are the stylosporous condition of Bhytisma, which develop 

 asci in the same stroma after the leaves have fallen and 

 rested on the ground during winter. Actinothecium has 

 an orbicular scutate perithecium, which dehisces by several 

 radiating fissures. In the other group, in which the perithecia 

 split longitudinally — the chief is Zeptostroma, which corre- 



