MICHIGAN ACADEMY OF SCIENCE. 
249 
3. On Cherry-trees: (Witches’ brooms.) 
4. On birch: (Witches’ brooms.) 
5. On alder-catkins : 
6. On carpinus: (Witches’ brooms.) 
7. On poplar-catkins : 
April 20, 1911, Univ. of Mich. 
Exoascus cerasi. 
Exoasciis turgidus. 
Exoascus alni-incanae. 
Exoascus carpini. 
Taphria aurea. 
