1901] MICROSCOPICAL JOURNAL. 279 
Epithemia gibba, so remarkably abundant at Topeka, 
was present, but rather uncommon. Of the three or four 
species of Nitzschia, only one seemed to be of a common 
variety, and one of them, Witzschia sigma, is catalogued 
by different authorities as a marine form. A most re- 
markable thing was that not a single Surirella of any 
kind was seen in the three slides mounted. As they are 
one of the most abundant forms everywhere, and there 
being plenty near at Medora, we must either conclude 
that there were none where the fish lived, or that they 
possessed some poisonous or other undesirable qualities 
which caused him to reject them. 
One of the most remarkable things found was Masta- 
gloia. The genus is almost exclusively marine or brack- 
ish, and only one of the two species areever found in fresh 
water, and they are excessively rare. This one, M. lacu- 
stris, was not found at Cincinnati ; though an allied species, 
M. lanceolata, was recognized there with some slight re- 
serve. It is also catalogued by Thomas and Chase, but 
none of either was found at Gage’s pond or Silver Lake. 
Another seems to be what Grunow calls Nitzschia apicu- 
lata, though the blank line down the center and the ab- 
sence of alea seem to identify it with Synedra. 
To give an idea of the relative proportions of the genera 
present in a field of view one-fiftieth of an inch in dia- 
meter, selected merely because it had an Amphiprora in 
it, so as to inc)ude that, there were the one Amphiprora, 
one Amphora, one Cymbella, two Nitzschia, three Pleuro- 
sigma, and thirty-four Navicula. 
The genera and species, so far as observed, were as fol- 
lows : 
Amphiprora conspicua (?), (perhaps columetica?); paludosa W. S., 
said to be British. Amphora cymbifera Greg,; lineata; No. 18, Sch- 
midt’s Atlas, pl. 39. Cocconeis pediculus. Cocconema australicum 
A.5S.; cistula; helveticum; hungaricum; lanceolatun; mexicanum. 
Cyclotella rotula; a small unknown. 
