ASCOMYCETES 361 



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

 ends rounded, 20x8-10 /x. 



Oidium stage ( = Oidium tuckeri). 



Phyllactinia, Lev. 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., Mich., 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 /x, 2, seldom 3-4, spored, spores ovate, 

 variable in size, 40-52X22-25 /x. 



Sphaerotheca, 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., 1851, 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 p. 



Conidia in chains, terminal one the oldest, elliptical, 

 hyaline, 20-30 X 13-16 p. 



Sphaerotheca castagnei, Lev., A?in. Sci. Nat., 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 



