OVULARIA. 501 



O. alnicola (Cke.). On Alnus glutinosa. 

 O. scelerata (Cke.). On Ranunculus sceleratus. 



O. rosea (Fuck.) produces irregular brown spots on the leaves of 

 various species of willow. 



O. asperifolii (Sacc). On Sympkyfam offidnalii. 



O. veronicae (Fuck.). On spots on leaves of Veronica Ckamaedrys, etc. 



O. lamii (Fuck.). On Lamiwn. 



O. syringae (Berk.). On Syringa. 



O. sphaeroidea Sacc. causes spots on leaves of Lotus. 



O. cameola Sacc. On spots on leaves of Scrophularia nodosa. 



O. bistortae (Fuck.). On spots on leaves of Polygonum Bistorta. 



O. obliqua (Cke.). On leaves of Rumex. 



2. Sect. Didymospobae. 



Didymaria. 



Conidia two-celled, colourless, and produced singly at the 

 extremity of simple erect conidiophores. 



Didymaria prunicola Cav. Cavara states that this causes 

 raised roundish spots on the upper surface of leaves of plum ; 

 finally the leaves gradually dry up and fall off. Slender two- 

 celled conidiophores are produced, and give off" each a two-celled 

 obovoid conidium. 



D. Ungeri Cord. On living leaves of Ranunculus repens. (Britain.) 

 D. astragali (Ell. et Hoi.). Found on leaves of Astragalus canadensis. 

 D. spissa Hark. On leaves of Solidago oocidentalis ; both species in 

 North America. 



Bostrichonema. 



Conidiophores erect, spirally twisted, unbranched, and non- 

 septate. Conidia elliptic or oblong, two-celled, and hyaline. 



Bostrichonema alpestre Ces. On living leaves of Polygonum 

 viviparum and P. Bistorta. (Britain.) 



B. modestum (B. et B. White). On leaves of Alchemilla 

 alpina. (Britain.) 



3. Sect. Phragmosporae. 



Ramularia. 



Conidiophores emerging in tufts from the stomata ; they give 

 off a terminal conidium, then bend over and produce a lateral 

 conidium, and so on they branch in a sympodial manner, pro- 



