226 INTRODUCTION TO THE STUDY OF FUNGI 



WWXi0sQ 



Sporomega. The last genuine species is Ostropa, in which the 

 perithecia are almost sphaeroid, dehiscing above with a 

 longitudinal fissure, thus suggesting relationship with the 

 Lophiostomaceae. The rather aberrant 

 genus Bdbergea is sometimes placed 

 here, as having affinity with Ostropa ; 

 but Acrospermum, appears to us to 

 be more closely related to Hypocreaceae, 

 from the absence of any apical fissure. 

 The total number of species in 

 this subfamily may be accepted as 

 450, and of these some have a very 

 wide geographical distribution. It is 

 an open question whether the family 

 is most closely allied to the Pyreno- 

 myceteae or the Discomyceteae. The 

 consolidation of the hymenium into 

 a disc, and the strong development of the paraphyses, indicate 

 relationship with Discomycetes, and this is supported by the 

 almost universal subsuperficial habit. This is not, however, 

 a question of practical importance, and may be compromised 

 by placing the Hysteriaceae as an intermediate group between 

 the Pyrenomycetes and the Discomycetes. 



Fig. 103. — Sporomega with 

 enlarged perithecium and ascus. 



BIBLIOGRAPHY 



Saccakdo, P. A. " Hysteriaceae,' in Saccardo Sylloge Fimgorwm, vol. ii. Imp. 



8vo. Padua, 1883. 

 Duby, J. E. Mimoire sur la tribu des Hysterinees. 4to. Plates. Geneva, 1861. 

 De Notaris, G. "Prime Knee di una disposizione de Pirenomiceti Isterini," in 



Giorn. Bot. Ital., vol. ii. Florence, 1847. 

 Billings, J. S. "The Genus Hysterium and some of its Allies." American 



Naturalist, vol. v., October 1871. Salem, Mass. 

 Rehm, H. "Revision der Hysterineen," in Hero Duly. Dresden, 1886. 

 Masses, G. "Hysteriaceae," in British Fungus Flora, vol. iv. 8vo. London,, 



1895. 



