162 
Journal of Mycology 
[Vol. 11 
immature ascus with eight spores as ordinarily seen. Fig. 28 
shows a spore in which a constriction is beginning to form, and 
Fig. 29 shows the spore after it has divided and formed two 
spores. Fig 30 shows a mature ascus with sixteen ascospores. 
In no other species of Phyllachora did I find more than eight 
spores in an ascus. The sixteen ascospores seem to place it in 
another genus, but the character of the stroma would make it a 
Phyllachora. Material which had been collected in Ohio was 
either sterile or immature. 
EXPLANATION OF PLATE 79. 
A Leitz microscope with oculars 18 and 0 and objectives 7 and 3 
were used in making the magnified drawings. The plate was made from 
the original drawings and reduced 2J4 diameters. 
For Figs. 4, 9, 13, 16, 19, 22, 23, 27, 28, 30 and 31 a No. 18 ocular 
and No. 7 objective were used, giving a magnification of 500 diameters. 
For Figs. 3, 8, and 14 a No. 6 ocular and No. 3 objective were used, 
giving a magnification of 166 Diameters. 
For Figs. 2, 7, 12, 17, 21, and 26 a No. 6 ocular and No. 3 objective 
were used, giving a magnification of 27 diameters. 
Figs. 1, 5, 6, 11, 17, 20, and 25 showing hosts, are natural size unless 
otherwise indicated. 
1-4. Phyllachora trifolii (Pers.) Fckl. on Trifolium wormskioldii. 
1. Host plant natural size. 
2. Cross section of leaf showing perithecia. 
3. Ascus. 
4. Ascospore. 
Figs. 5-10. Phyllachora ambrosia (B. & C.) Sacc. on Ambrosia psilos- 
tachya. 
5. Host plant natural size. 
6. A piece of leaf magnified two diameters showing stroma. 
7. Cross section of leaf showing perithecia. 
8. Asci. 
9. Ascospore. 
10. Paraphyses. 
Figs. 11-13. Phyllachora diplocarpa E. & E. on Distichlis spicata. 
11. Host plant natural size showing stroma on surface of leaf. 
12. Cross section of leaf showing perithecia. 
13. Conidiospore. 
Figs. 14-16. Phyllachora graminis ? (Pers.) Fckl. on Bouteloua oligos- 
tachya showing how asci and paraphyses are fascicled 
(14-15). 
14. A mature and an immature ascus. 
15. Paraphysis. 
16. Ascospores. 
Figs. 17-19. Phyllachora lespedezae (Schw.) Sacc. on Lespedeza repens... 
17. Leaf of host showing the stromata. 
18. Cross section of leaf showing perithecium. 
19. Asci containing ascospores. 
Figs. 20-24. Phyllachora cornuospora Atk. on Panicum agrostoides. 
20. Host plant magnified two diameters showing stroma. 
21. Cross section of leaf showing perithecia. 
22. Ascus containing ascospores. 
23. Mature ascospores. 
24. Paraphyses. 
