ilAN 271899 



Article VI. — A List of the Protozoa and Rotifera found in 

 the Illinois River (Did Adj<(eent Lakes at Havana, III* 

 By Adolph Hempel. 



INTRODUCTORY. 



The material studied in the preparation of this paper was 

 collected at the Biological Experiment Station established on 

 the Illinois River, at Havana, April 1, 1894, by the Univer- 

 sity of Illinois and the Illinois State Laboratory of Natural 

 History. The work of collecting the material ])egan April 

 7, 1894, and was carried on almost entirely at nine substa- 

 tions, designated as A, B, C, D, E, F, G, K, and L. The 

 first three are in Quiver Lake, which is an arm of the river 

 on its east side, about two miles above Havana. A is at the 

 head of the lake ; B, at a wet, springy place on the eastern 

 shore, about half a mile from the head ; and C, about a mile 

 and a half from the head, including both the east and Avest 

 shores at this point as well as the middle of the lake, where 

 the towing-net was hauled, the depth here at low water being 

 about four feet. D is about half a mile above Havana, on the 

 east bank of the river, and E about two and a half miles north 

 of the town, in the main river, opposite C, collections l)eing 

 taken especially from the west shore and the middle of the 

 river, where the depth at low water was about nine feet. About 



*15efore Mr. Ueuipel had completed that part of his raaimseiipt relating to the 

 Protozoa, he left to accept a position in the Muse~i PauUsta, in Sao Paulo, Brazil, and 

 the entire manuscript was placed in my haikls by Dr. Forbes to be prepared for jmb- 

 lication. At first I was reluctant to undertake the work, but realizing the value of 

 the paper as planned by Mr. Hempel to students and teachers of Ulinois natural 

 history, I have spared no effort to put it in the most useful form for this class of 

 workers. 



On account of the limited time and area represented in this list, it can only be 

 regarded as a preliminary one, not sutticient for permanent generalizations on "sea- 

 sonal or locUl distribution, but rather as a history of these groujis at the Station 

 during the two years covered by Mr. Hempel's work. It seemed undesirable, for the 

 same reason, to attempt to give keys to the species listed. I have, however, for the 

 Protozoa, carefully compiled from BiUschli a synopsis of the distinctive chaiucters of 

 the larger subdivisions represented .in the list, and have drawn up from Biitschli, 

 Leidy, and Kent condensed generic descriptions, following, as did :\Ir. Hempel, the 

 order given by BiUschli. The chlorophyll-bearing forms, such as Volvox and EiKjlena, 

 are retained among the Protozoa since they are included by BiUschli, but it is proper 

 to state that they are now regarded as plaiUs by a large number of authors. For the 

 Rotifera. 1 have compiled a synopsis of the families from Hudson and Gosse, and 

 Mr. Hempel's generic diagnoses are mostly from the same source. 



Under each species in the list is a brief account of the im)iortaut points in its 

 history for the two years. These accounts were drawn up from Mr. Hempel's records, 

 and may prove of especial value to students at the Station. Aside from these simi- 

 maries and the additions previously mentioned, the manuscript remains substantially 

 as Tslr. Hempel left it, and will lie found to contain much interesting and useful 

 information for the student of microscopic life. CHAS. A. HART. 



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