REPORT OF THE LOTANIST. 63 
ceous-brown, five to ten-septate, .002’-.0036’ long, includ- 
ing the very short concolorous peduncle. 
Leaves of soapwort, Saponaria officinalis. Greenbush. 
September. 
The spores are often longer than the flocci. 
NEMATOGONUM AURANTIAOUM Desm. 
Cut surface of a birch stump. Lake Pleasant. August. 
PERONOSPORA OBLIQUA Cooke. 
Living leaves of yellow dock, Rwmex crispus. North 
Greenbush, October. 
PERONOSPORA GERANII 2. Sp. 
Effused, sometimes occupying the whole under surface 
of the leaf, whitish, the flocci irregularly branched, branches 
short, divaricately spreading, the apices not swollen, fur- 
nished with short slender spicules ; acrospores globose, 
.0006’ in diameter. 
Living leaves of Geranium maculatum. North Green- 
bush. June. 
Related by its spiculose branches to P. gangliformis. 
ERYSIPHELLA 7200. gen. 
Perithecia destitute of appendages, spores definite. 
This genus differs from Perisporium in having a definite 
number of spores in an ascus, and from Uncinula, Micros- 
phera and Hrysiphe in being destitute of appendages. 
ERYSIPHELLA AGGREGATA 2. Sp. 
Mycelium obscure or concealed ; perithecia numerous, 
densely crowded, subglobose, glabrous, reddish-brown or 
black ; sporangia numerous, ten to twenty, varying from 
oblong-ovate to subclavate ; spores eight, broad, elliptical, 
-0008’—.0009’ long, .0005’—.0006’ broad. 
Fertile aments of alders. North Greenbush. May. (Plate 
2, figs. 1-3.) 
The perithecia are densely aggregated in the interstices 
of the aments, giving them a compact blackened appear- 
ance. Usually a white meal-like substance more or less 
involyes and, with the crowded perithecia, conceals the 
mycelium. Sometimes nearly all the aments in a cluster 
are covered by this fungus. 
