154 ASCOMYCETES. 



III. Species which produce (1) pustule-like outgrowths, (2) 

 leaf-spot, or (3) smooth coatings of asci. 



H. aureus (Pars.) on Populus nigra (incl. pyramidalis) 



and F. monUifera. 

 JS. polysporus (Sor.) on Acer tartaricum and A. Pseudo- 



platanus. 

 E. bullatus (Berk, et Br.) on Pyrus communis and Cydonia 



japonica. 

 E. carneus (Johan.) on Betula nana, B. odorata, and P. 



intermedia. 

 E. coerulescens (Desm. et Mont.) on Quercus puhescens, Q. 



sessiliflora, Q. Cerris, Q. laurifolia, Q. rubra, Q. tinctoria, 



Q. aquatica. 

 E. Sadebeckii (Johan.) on Alnus glutinosa. 

 E. ulmi (Fuck.) on Ulmus campestris, U. montoMa, and U. 



americana (spots and blisters). 

 E. virginicus (Sey. et Sad.) on Ostrya virginica. 

 E. australis (Atk.) on Carpinus americanus. 

 E. filicinus (Eostr.) on Aspidium spinidosum. 

 E. potentillae (Farl.) on Potentilla geoides, P. canadensis, P. 



sylvestris. 

 E. githaginis (Rostr.) on Agrostemma Githago. 

 E. lutescens (Eostr.) on Polystichum Thelypteris. 

 E. umielliferarum' (Eostr.) on Heradeum Sphcndylivm,, Peu- 



cedanum palustre and P. Oreoselinum. 

 E. ostryae (Mass.) on Ostrya carpinifolia (brown spots). 

 E. hetulae (Fuck.) on Betula vemicosa, B. puhescens, B. 



turkestanica (whitish spots). 

 E. Jiavus (Farl.) on Betula populifolia, B. papyracea. 

 E. acericolus (Mass.) on Acer campestre and A. Pseudo- 



platanus. 

 E. fasciculatics (Lag. et Sad.) on Nephrodium (whitish spots). 



The following are some of the more important species of 

 Exoasceae : 



Exoascus pruni Fuck. (Pocket-plums). This attacks the 

 ovaries of Prunus domestica (plum), P. Padus (bird cherry), and 

 P. virginiana, causing the mesocarp to grow rapidly, whereby 

 the fruits increase in size and become much changed in form. 



