1912-1913-] Notes on Parasitic A scomycetes. — III. 2 7 



Lorrain Smith, F.L.S., to whom it was submitted, has kindly 

 pointed out that it belongs rather to B. knautice. She states 

 that the latter was first described by Massalongo as a variety 

 of B. succisce, but " differs from that species in the much 

 darker leaf-spots and the smaller spores." x 



VI.— NOTES ON PARASITIC ASCOMYCETES.— Part III. 2 



By Mr D. A. BOYD, Corresponding Member. 



{Read April S3, 1913.) 



The fungi grouped under the Hysteriaceas may be said to 

 occupy a position intermediate between the Pyrenomycetes 

 and Discomycetes. They resemble the Pyrenomycetes in 

 the hard or leathery consistence of the outer integument or 

 wall of the perithecium, but differ in the manner by which the 

 spores are emitted. In the HysteriaceaB there is no apical 

 pore, but the perithecium usually opens by a narrow slit ex- 

 tending longitudinally, the position of which is often marked 

 by a conspicuous furrow. 



The vast majority of the Hysteriacese are saprophytes, and 

 grow on dead branches, stems, leaves, fir-cones, &c. Several 

 species, however, are saprophytic in their fully matured or 

 ascigerous state, but are reputed to be parasitic at an earlier 

 stage of development. Of these an example is afforded by 

 Lophodermium pinastri (Schrad.) Chew, common on dead pine 

 leaves, but also said to occasion serious damage to seedling 

 conifers by causing them to cast their foliage, and not unfre- 

 quently killing them outright. 



To this group is also usually assigned Diehcena quercina 

 (Pers.) Fr., which, in its undeveloped or pycnidial state, is 

 exceedingly common on the bark of living oak-trees, occurring 

 on almost every branch. It forms black patches, rough or 

 rugulose on the surface, and often of considerable extent. The 

 asci, however, are rarely produced. They contain eight broadly 



1 'Trans. Brit. Myc. Soc.,' vol. iii. p. 370. 



a See 'Transactions,' vol. vi., Pt. iv., p. 333, and vol. vi., Pt. v., p. 431. 



