ROTATORIA OF THE UNITED STATES. 
99 
Family 22. ANAPODIDJE. 
ANAPUS Bergendal. 
100. A. ovalis Bergendal. 
One specimen, from surface towing in Lake Erie, taken miles north of Kelley Island. 
Lake St. Clair (Jennings, ’94); Lake Michigan, Round Lake, and West Twin Lake near 
Charlevoix, Mich. (Jenuings, ’96). 
Family 23. PEDALIONIDiE. 
Pedal-ion mirum Hudson. — Sandusky Bay, Lake Erie (Kellicott, ’97). Waters connected with the 
Illinois River at Havana, 111. (Hempel, ’98). 
SUMMARY. 
The foregoing list shows that (excluding varieties, synonyms, and doubtfully 
identified animals) 240 species have been recorded as occurring in the United States. 
These are distributed by States, as follows: Michigan 100, Ohio 155, Illinois 112, New 
Jersey 29, New Hampshire 23, New York 21, Maine 18, Minnesota 18, Pennsylvania 
13, Vermont 6, Yellowstone Park 4, Louisiana 2 (?), North Carolina 2 .(?), Virginia 1, 
Wisconsin 1, California 1. 
It will be understood of course that the fact that large numbers are recorded 
from certain States, while in others few or no rotifers have been observed, is due 
purely to unequal distribution of investigators. It is probable that at least as many 
species of Rotifera as are included in the entire list might by careful investigation be 
found in any State in the Union. 
The only large bodies of water that have been investigated with any degree of 
completeness are Lake St. Clair, Lake Erie, and the Illinois River. In the Great 
Lakes there have been found altogether 164 rotifers. Lake Erie has 132 species, Lake 
St. Clair 111 species, Lake Michigan 25 species. From the other Great Lakes no 
rotifers have been recorded. From the Illinois River 105 species and 5 varieties have 
been recorded; 74 of these are common to the Illinois River and the Great Lakes; 25 
are found in the Illinois River and not in the Great Lakes; 90 in the lakes and not in 
the Illinois River. 57 species have been found neither in the Great Lakes nor in the 
Illinois River, but in small ponds, pools, streams, and swamps in various parts of the 
United States. 
The fauna of the Illinois River is characterized, as compared with that of the 
Great Lakes, by a greater proportion of species living in swampy regions. The 25 
species which are recorded from that stream and which have not been found in the 
Great Lakes include, for example, 3 species of Asplanchna and 7 Brachionidse, char- 
acteristic swamp Rotifera. Several of the species occurring in the Illinois River and 
not found in the Great Lakes have been found in swamps or small bodies of water in 
immediate proximity to the lakes. This is true for example of Trocliosphcera solstitialis. 
On the other hand, the fauna of the Great Lakes is marked by the presence of a 
number of distinctly limnetic Rotifera not found in the Illinois River, such as Floscu- 
laria mutdbilis Bolton, F.pelagica Rousselet, Conochilus volvox Ehr., Notops pelagicus 
n. sp., Notommata monopus Jennings, Ploesoma hudsoni Imhof, Gastropus stylifer Imliof, 
and Anapus ovalis Bergendal. 
