ASCOMYCETES 375 



4-5 /x ; conidia same as in JV. vandae, inserted in tufts at 

 the apex of the sporophore. 



Polystigma, Pers. — Stroma rather fleshy, parenchy- 

 matous, effused, innate on the leaf, ochraceous, tawny, or 

 reddish ; perithecia immersed ; asci 8-spored ; spored ovoid 

 continuous ; spermogonia usually present. 



Polystigma rubrum, D. C, Mem. Mus., p. 337, pi. 4, 

 f. 7. — Hypophyllous, suborbicular, reddish, then reddish- 

 brown, ostiola sunk ; asci clavate, 8-spored ; spores ovoid, 

 obtuse, straight, subhyaline, 10x6 //. 



Spermogonia {Libertella rubra, Bonor). — Spermatia fili- 

 form, curved, 30 /x long. 



Dothidiaceae. — Compound, stroma pulvinate, effused, 

 or linear, coriaceous or carbonaceous (not fleshy), blackish 

 (not brightly coloured) ; perithecia or loculi confluent and 

 homogeneous with the substance of the stroma, but dis- 

 tinctly defined, mouth distinct ; asci 4-8-spored ; spores 

 often hyaline, rarely brownish ; secondary forms of fruit 

 common. 



Plowrightea, Sacc. — Stroma convex-pulvinate, often 

 confluent, and form an extended crust, thickish, coriaceous, 

 becoming black ; asci elongated, 8-spored ; spores ovoid 

 or elliptical, i-septate, hyaline, or faintly tinged with 

 yellowish green ; conidia and pycnidia known in some 

 species. 



Plowrightia morbosa, Sacc, SylL, ii. 638 (1883). — 

 Stromata caestipose, forming large, elongated, nodulose, 

 rigid, black incrustations on branches. Conidiophores 

 bearing ovoid olive conidia, about 16 /x long, first covering 

 young stromata with a blackish-olivS velvety layer ; peri- 



