396 Witson: NortTH AMERICAN PERONOSPORALES 
the epispore brown, irregularly wrinkled, permanently united to 
the persistent wall of the odgonium. 
Type species, Protomyces graminicola Sacc. 
Key to the species 
Odspore small, 26-36 4 ; epispore not pronouncedly opaque ; host, 
C 1. S. graminicola. 
Oéspore large, 28-45 «4; epispore very opaque; host, Chloris. 2. S. Farlowit. 
I, SCLEROSPORA GRAMINICOLA (Sacc.) Schroter, in 
Cohn, Krypt. Fl. Schles. 3': 236. 1886 
Protomyces graminicola Sacc. Nuovo Giorn. Bot. Ital. 8: 172. 
1876. 
Peronospora graminicola Schroter, in Zopf & Sydow, Myc. March. 
g. 1881. 
Peronospora graminicola Setariae-italicae Traverso, Bull. Soc. Bot. 
Ital. 1902: 168. f. 7-3. 1902. > 
Infesting leaves and inflorescence, causing marked distortion 
of the latter and, in the case of odspores, the rapid disintegration 
of the former; conidiophores 100 x 10-12 #; conidia 20 x I5- 
184: oogone-wall thick, 4-12 , at maturity 30-60 pz diam., reddish- 
brown ; odspore pale-brown, 26-36 p. 
The conidiophores of this species are very stout and quite un- 
like those of any other American species of the order. Their very 
ephemeral character has caused them to be overlooked by collec- 
tors, while the reddish-brown color given to the leaves by the 
oospores renders them rather conspicuous objects. As a result 
herbarium material of this species is rich in odspores while the 
conidia are rare. The variety on Chaetochloa italica is described 
as having much larger oospores than does the typical form, but 
an examination of American as well as authentic foreign material 
upon this host failed to show any constant or appreciable differ- 
ence between the material upon this and upon the other hosts of 
the species. 
On POACEAE: 
Chaetochloa italica (L.) Scribn., Iowa, * Halsted ; Michigan, 
Wheeler ; Wisconsin, * Pammel. 
Chaetochloa viridis (L..) Scribn., lowa, Carver 1 3, * Halsted 
N. Am. Fungi 1803a), * Hitchcock, * Pammel (Econ. 
