14 



Amphigcnous. Mycelium abundant, persistent, haustoria of the 

 mycelial tlircMils lobed. IVrithecia somewhat {iguregatcd, appendages 

 numerous, short, llexuoiis, colored, interwoven with the mycelium. 

 Asci numerous, often 12 or more. Sporidia 2, mostly formed late. 



On Tcm-rtuin Coin/dense, Mentha, ^cntcUurni Iiitcrijloru, S. 

 xj><>i'<t. (tulcnf^ix Tch'iihit. Chelone <jl<ibr<i. 



Widely distributed east of the Rocky Mountains and in Montana 

 i Anderson), hut not often distinguished from E. Cichoracearum in 

 published lists. It can scarcely be separated from the latter l>y the 

 rlmracters of the perithecia, but the difference in the haustoria, first 

 pointed out by De Bary (Morph. uncl Phys. der Pilze, III. p. 49), can 

 be observed by first soaking a portion of the leaf in caustic potash and 

 then removing a little of the mycelium to the slide. The peritheeia 

 and appendages are often rather lighter colored than is usual in E. 

 Cichoracearum. 



E. aggregata, (Peck). 



Erysiphella aggregata^ Peck 2Sth Rep. N. Y. State Mus. Nat. Hist. p. 63. 

 Erysiphe aggrcgata, Farlow, Bull. Bussey Inst. II, (iS/Si, p. 227. 



Mycelinm dense, felt-like, white, but becoming yellowish. Peri- 

 thecia very numerous, closely crowded, opake, thick-walled, with 

 rather small cells, 140-180 ,; appendages very numerous, inter- 

 woven, hyaline or nearly so, rather slender. Asci numerous, 10-50. 

 oblong-ovate or sometimes narrower, thick-walled. Sporidia crowded 

 in the ascus, oval, mostly 15-20 // long. 



On the fertile ainents of Alnus serrulata and of A. incamt, in 

 autumn arid spring. 



Reported from Massachusetts (Farlow). Xew York (Peck), New 

 Jersey and Pennsylvania (Ellis); said to be common in these localities. 

 The genus Erysiphella was proposed for this when it was supposed 

 there were no appendages, 



E. triiia, Hark. Trans. Cal. Acad. of Sci. 1884, p. 41. 



Epiphyllous. Mycelium covering orbicular spots, pruinose, fuga- 

 cious. Perithecia clustered, minute, yellowish-brown, 56-70 //; append- 

 ages none. Asci 3, nearly globular, 31-38 p.. Sporidia 2, oblong- 

 elliptical, or somewhat boat-shaped, very large, sometimes filling the 

 ascus, 18-20x28-32 p. 



On Quercus agrifolia, California (Harkness). Inserted from 

 I taper by Dr. Harkness, read before the California Academy of Sci- 

 ences, February 4, 1884. 



No specimens examined. In the original, Erysiphella is given 

 as an alternate genus. 



