ASCOMYCETES 361 



coloured; asci ovate, pedicellate; spores 4-6, elliptical, 

 ends rounded, 20x8-10 /x. 



Oidium stage {^=Oidiiiin tuckeri). 



Phyllactinia, Le\\ — Perithecia globoso-depressed, con- 

 taining many asci, large, appendiculate, seated on arach- 

 noid mycelium ; asci 2-4-spored ; appendages acicular, 

 straight, radiating, base inflated into a vesicle. 



Phyllactinia suffulta, Sacc, MicJi.^ ii. p. 50. — Amphi- 

 genous or often most abundant on the under surface of 

 leaves, cobweblike, often evanescent ; perithecia scattered, 

 hemispherical, at length depressed, large; asci 4-20, ovate, 

 pedicellate, 80X50 /^, 2, seldom 3-4, spored, spores ovate, 

 variable in size, 40-52 x 22-25 i"* 



Sphaerotlieca, Lev. — Perithecia containing one ascus 

 only ; ascus subglobose, octosporous ; spores elliptical, 

 continuous, hyaline ; appendages of the perithecium 

 filamentous, tips not branched, mixed with the mycelium. 



Sphaerotheca pannosa, Lev., Ann. Sci.Nat., 185 1, vol. xv. 

 p. 138, pi. 6, f. 8. — Mycelium cottony then densely felted, 

 white, then tinged ochraceous, persistent ; perithecia 

 minute, globose, scattered ; appendages, floccose, hyaline, 

 short; asci subglobose; spores 8, elliptical, 22-25 x 

 13-16 fji. 



Conidia in chains, terminal one the oldest, elliptical, 

 hyaline, 20-30 x 13-16 //. 



Sphaerotheca castagnei. Lev., Ami. Sci. Naf., 1851, 

 vol. XV. p. 139, pi. 6, f. 9, 10. — Forming a white, cobweb- 

 like, often evanescent mycelium on both surfaces of leaves 

 or on inflorescence; perithecia scattered, spherical, minute; 

 appendages numerous, short, brownish appendages with 



