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IOWA ACADEMY OF SCIENCE Voi,. XXVII, 1920 
species of rotifers, principally the loricate forms. These fish ponds 
are shallow artificial ponds ; most of them have Ceratophyllum and 
other aquatic plants in them. 
17. Sunken lake. This is a small, very deep lake, not far 
from the west shore of Spirit lake, having practically no aquatic 
vegetation near the shore, where the collecting was done. 
18. Hottes Lake. Hottes lake is of good size, but is rather 
shallow. Its shores slope off very gradually, and many species 
of rotifers were taken from among the water plants near the 
bank. 
19. Little Spirit Lake. A tow was taken from among Cerato- 
phyllum and algae near the bank of Little Spirit lake, bringing 
several species of rotifers. 
20. Marble Lake. Marble lake is quite similar to Hottes lake, 
but is somewhat larger. Its banks are edged with reeds. 
21. Little Sioux river. Five species of rotifers were found 
in water from Little Sioux river, a small rather sluggish stream 
about two and a half miles from the laboratory grounds. 
LIST OF ROTATORIA 
With notes on distribution, and other features 
ORDER PLOIMA 
N otommata aurita (Muller) (Plate VI, Fig. 1). Several individuals of 
this species were found in water from the swamps about Center lake (13). 
N otommata brachyota Ehrenberg (Plate VI, Fig. 2). This species was 
found in abundance on Rivularia echinulata, floating in Miller’s bay (1). 
The animal is a voracious feeder; several groups of Rivularia were found 
in which the trichomes were almost wholly eaten away, each with four 
or five rotifers on it. The animal is salmon pink in color. On the 
Rivularia were also found a few V orticellae ; one specimen of Taphro- 
campa annulosa was found here also. Rivularia from several other 
localities was examined, but rotifers were found only on that from Lake 
Okoboji. 
Notommata copeus Ehrenberg (Plate VI, Fig. 3). Only one individual 
of this species was found, in water from the vicinity of Center lake (13). 
N otommata najas Ehrenberg (Plate VI, Fig. 4). This large species was 
found in water from: ponds and kettle holes near the north end of Lake 
Okoboji (10), several individuals being taken here. It was met with again 
in water from Little Spirit lake (19). 
Notommata pachyura ’(Gosse) (Plate VI, Fig. 5). Found near the 
entrance of the drainage canal (2), eight individuals being recognized. 
Notommata saccigera Ehrenberg (Plate VI, Fig. 6). This species was 
found in considerable numbers in a jar of alg^, chiefly Mougeotia, which 
had been brought into the laboratory; records failed to show from what 
