5° 
The Ohio Naturalist. 
[Vol. X, No. 3, 
Monochytrium presumably has as great an opportunity for the 
dispersal of its spores in dewdrops and spattering rain as has 
Synchytrium. The writer is therefore led to expect that when 
the zoospores of Monochytrium are observed they will be found 
to be amoeboid rather than flagellate. 
For a summary of the most important points in the life 
history of Monochytrium a condensed technical description may 
be offered. The type and only known species I propose to name 
in honor of Professor F. L. Stevens who has made notable con- 
tributions to the cytology of the lower fungi. 
Monochytrium gen. nov. 
Mycelium nullum, plasmodium rotundatum; sporae perdurantes 
30-50/p globosae, ortae a copulationis zoosporarum intra cellulas 
matricis, binucleatae, exosporio crasso, paene levi non echin- 
ulata; zoosporangia circa 70 /p formata a zoosporis sine copula- 
tione, unum a quoque plasmodio, sine membrana, sine collo; 
zoosporae numerosissimae, 2.5/p moto ignoto. 
Intra cellulas epidermicas aut hypodermicas aut raro chlorenchy- 
matas plantarum viventium. 
Monochytrium stevensianum sp. nov. 
Characteribus generis. Intra cellulas foliarum petiolorumque 
Ambrosiae artemisiifoliae in Raleigh, Carolina boreali; Stevens & 
Hall Julio 1908. 
The slides containing the type specimens are deposited in the 
herbarium of the Ohio State University. With them are index 
cards giving the location of the cysts drawn, in vernier readings 
of the Spencer Lens Company’s mechanical stage No. 490 with 
the verniers set to read 30 and 90 respectively when the aperture 
in the centering slide accompanying the instrument occupies the 
optical axis of the microscope. The originals of all the figures 
may therefore be quickly found with any microscope equipped 
with a No. 490 mechanical stage, or with any mechanical stage 
with a vernier reading to tenths of millimeters for after one is found 
and the differences in reading between stage No. 490 and the one 
employed are determined, all may be located by simple additions 
to the readings given. 
