SuMSTiNE : North American Hyphomycetes 59 
Amphigenous, white, effused, forming a dense stratum on the 
leaf ; mycelium branched, interwoven ; sporophores erect, simple, 
septate ; spores smooth, ellipsoid, granular within, 25-27 X 40-50 yn. 
On leaves of Platanus orientalis L., Pittsburgh, Pa., August, 
1912. 
It attacks the young leaves usually and causes them to curl up 
and die. Unless checked it may become a dangerous shade tree 
disease. 
10. Acrosporium Gossypii sp. nov. 
Hypophyllous, white to sordid white, effused, thin, spreading 
over the leaf ; mycelium branched, interwoven ; sporophores erect, 
simple, dividing into spores ; spores barrel-shaped, ellipsoid, trun- 
cate at the ends, 16-24 X 40-50 
On Gossypium sp. (Cotton). Kingston, Jamaica. 
The type was collected by T. D. A. Cockerell and sent to me by 
Flora W. Patterson, of the Bureau of Plant Industry, Washing- 
ton, D. C. It was labeled Oidium erysiphoides. 
Oiditim erysiphoides Fr.^® is a composite species. The name 
cannot be applied to any particular form of this genus but belongs 
to all the forms in general. 
Species Reported 
The following species have been reported from North America, 
but no specimens were examined. They probably belong to the 
various genera described in this paper. 
1. Oidium albipes Peck, Ann. Rep. N. Y. State Mus. 30: 57. 
1878. 
2. Oidium Asteris-punicei Peck, Bull. N. Y. State Mus. 150: 
35- 1911- 
3. Oidium candidum Schw. Trans. Amer. Philo. Soc. II. 4: 
285. 1832. The type of this species has been lost and the descrip- 
tion is too brief for determination. 
4. Monilia Harknessii Peck, Ann. Rep. N. Y. State Mus. 34: 
49. 1881. 
5. Monilia Avenae Peck, Bull. Torrey Club 33 : 219. 1906. 
Syst. Mycol. 3: 432. 1829. 
