398 Illinois State Laboratory of Natural History. 



Note. Three other genera have been described as follows : — 



(1). Pleochscta (Saccardo, Sylloge Fungorum, I., p. 9). Perithecia 

 globose-lenticular, indehiscent, texture subcoriaceous, parenchymatous ; 

 appendages very numerous, rod-like, straight, simple, hyaline ; asci 

 clavate, two-spored; spores simple, elliptical, subhyaline. P. Curtisii, 

 Sacc. & Speg. occurs on leaves of Celiis. in Alabama and Carolina, and in 

 South America. 



(2). Erysiphella (Peck, 28th Report, New York State Museum p. 63). 

 " Perithecia destitute of appendages, spores definite." E. aggregata, Peck, 

 is described on the fertile aments of Alnus serrulaia. 



(3). Saccardia (Cooke, Grevillea VII. [1878], p. 49). Mycelium 

 arachnoid, often evanescent ; perithecia globose, asci globose-ovate. 

 8-spored; spores elliptical, many-celled ; appendages none or interwoven 

 with the mycelium. S. quercina, Cooke on the leaves of Quercus virens, 

 Georgia, and S. Martii, Ell. & Sacc. on Q. laurifoHa, Florida, have been 

 described. None of these plants are known in Illinois. Doubts may be 

 expressed as to the validity of these groups as genera ©f Erydpliese. 



Calodadia, L(§v. is a synonym for Microsphxra, but was previously 

 used for a genus of Algx. 



Erysihe was used for Erysiphe by several authors, and "Wallroth's 

 genus Alphitomorpha was made to include all of the Erysiphese. 



SpHu^ROTHEOA, Lev. 



(Ann. Sci. Nat., Series III., Tome XV., p. 138.) 



Perithecium. containing only one ascus. Appendages simple 

 threads not unlike the mycelium with which they are 

 frequently interwoven. Ascus suborbicular, usually con- 

 taining eight spores. Very rarely two asci have been observed. 



S. pannosa, ( Wallr. ) Lev. 

 (1. c. p. 138.) 



Alphitomorpha pannosa, Wallr. ( Verhand. d. Naturf. Freunde, I., p. 43). 

 Erysibe pannosa, Lk. (Species Plant. VI., I., p. 104). 

 Euroiium rosarum, Grev. (Scott. Crypt. Fl. III., p. 164, Fig. 2), 



Mycelium abundant on the leaves, stems, etc., often sterile; 

 perithecia more often occurring on the branches, scattered, 

 delicate, 90-100 ^u., reticulations evident, small, 10-15 ^; ap- 

 pendages short and delicate, much interwoven with the 

 mycelium, sometimes colored ; ascus large, delicate, ovate, 

 expanding, when free from the perithecium, to a length greater 

 than its diameter; spores 8, large, 29 /a, long. 



