PLATE 2. 



Erysipheae. 



Uncinula Salicis, (D C). 



Fig. 1. Natural size on leaf of Salix flavcscens, var. Scoulcrlana, 

 from Montana. 



2. Part of a leaf with peritheeia magnified. 



3. Aperithecium highly magnified. 



4. An ascus. 



5. Three sporidia. 



6. A eonidia-bearing hypha* 



7. Five conidia. 

 3. Initial hyphae forming a pcrithecium. 



