S. Castaynei in published lists. The first named hosts are those Upoll 

 which the parasite has been considered distinct by Eai'le and the 

 writer ; the others are given upon the authority of the authors quoted. 

 The distinction between the two species in question is, however, 

 apparently real in the fact that the characteristically large, irregular 

 cells of the wall of the perithecium of S. Castagnei are not found in 

 those called S. Humuli, and the sporidia of the latter constantly 

 average larger than those of the former. The difference also in the 

 appendages seems to indicate specific distinction. Tulasne's figure 

 (Select Fung. Carp. I, tab. IV, fig. 9) clearly shows these peculiarities 

 of S. Htimuli, the name then used for the fungus. The much more 

 abundant mycelium of S. pannosa, and the smaller appendages sufii- 

 ciently separate that from 8. Humuli, though the affinities appear to 

 be quite as close here as between the latter and S. Castagnei, witli 

 which only our plant has been confounded. 



This is a very destructive parasite, especially on cultivated hops, 

 in the Old as well as in the New World. On raspberries it also does con- 

 siderable damage, though in many cases only the conidia are produced. 



On Geranium maculatum the cells of the wall of the perithecium 

 vary much, even in the same mount under the microscope, but the spo- 

 ridia and other characteristics are those of S. Hurtiuli. 



S. pannosa, (Wallr.) 



AlphitoTnorpha pannosa, Wallr. Verhand. d. Naturf. Freunde^ I, p. 43, 

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

 EutoHum Rosarum, Grev. Scott. Crypt. Fl. HI, p. 164, fig. 2. 

 , Sphterotheca pannosa. Lev. Aun. Sci. Nat. XV, p. 138. 



Mycelium abundant on the leaves, stems, etc., often sterile. Peri- 

 thecia more often occurring on the branches, scattered, delicate, 90- 

 100 /i, reticulations evident, small, 10-15 //; appendages short and 

 delicate, much interwoven with the mycelium, sometimes colored. 

 Ascus large, delicate, ovate, expanding, when free from the perithecium, 

 to a length gi-eater than its diameter. Sporidia 8, large, 29 fi long. 



On Rosa hlanda, R. Arlcansana, R. lucida, R. humilis, R. 

 parviflora. Rather common from K^ew England to California (Hark- 

 ness), and Texas (Jennings). 



Winter (Die Pilze, II, p. 26) and Saccardo (Syll. Fung. I, p. 2) 

 describe this species with hyaline appendages; but Tulasne (Select 

 Fung. Carp. I, p. 208) describes them as colored. They frequently 

 are colored in our specimens. De Bary (Morph. und Phys. der Pilze, 

 II, p. 48) says "colorless or brown at base." 



S. M.\li, (Duby). 



Erysiphe Mali, Duby Bot. Gall. p. 869. 



Sphmrotheca leucotricka, K. & E. Jour. Myc. IV, p. 58- 



Sphtzrotkeca Mali, T^utrill, (this publication). 



Amphigenous. Mjce]\um white, submembranaceous, persistent 



