204 ' KANSAS ACADEMY OF SCIENCE. 



M. quercina (Schw.) Burrill, Bull. 111. State Lab. Nat. Hist. II, p. 424. 

 Erysiphe quercinum Schw. Syn. N. Am. No. 2492 in Trans. Am. Phil. Soc. 

 N. S. 4: 270 (1834). "Hyphasma occupans fere totum folium expansum candi- 

 cans, tenuissimum, floccis vix distinctis sporangiolis raris minutissimis sparsis 

 nigris. Praesertim loco distinguenda species." Perithecia 90-100 mmm. Ap- 

 pendages 1-4 times diameter of perithecium, hyaline, much interwoven with 

 mycelium, 4-6 times dichotomous, branches short, tips recurved, sporidia 

 variable 3-8. On Quercus velutina Lam., Q. macrocarpa Michx., Q. Muhlen- 

 bergii Engelm. 



DESCRIPTION OF PLATES. 



Unless otherwise indicated all magnifications are as follows: Perithecia, 

 X 62; asci, x 225; sporidia, x 500; tips of appendages, x 500. 

 Sphaerotheca castagnei, Fig. 2. 

 Erysiphe communis, Fig. 9. 

 Erysiphe cichoracearum. Fig. 10. 

 Erysiphe graminis, Fig. 11. 



Uncinula necator, Fig. 4. Sporidia and tips, x 225. 

 Uncinula flexuosa, Fig. 5. 

 Uncinula macrospora. Fig. 6. 

 Uncinula parvula. Fig. 8. 

 Uncinula salicio, Fig. 7. 

 Phyllactinia suffulta. Fig. 3. Tips, x 225. 

 Podosphaera oxycanthae. Fig. 1. Tips, x 225. 

 Microsphaera grossulariae. Fig. 15. Tips, x 225. 

 Microsphaera symphoricarpi, Fig. 14. Tips, x 225. 

 Microsphaera euphorbiae, Fig. 13. Tips, x 225. 

 Microsphaera alni. Fig. 12. Sporidia and tips, x 225. 

 Microsphaera quercina, Fig. 16. Tips, x 225. 



