203] TURBELLARIA FROM THE MISSISSIPPI BASIN— HIGLEY 9 



The work, which was carried on for the most part at the University of 

 Illinois, was undertaken at the suggestion of Dr. Henry B. Ward. To him I 

 wish to express my sincere gratitude and appreciation for special opportunities 

 and for his great help and inspiration. 



I also had the opportunity to make collections and to study at the United 

 States Biological Station at Fairport, Iowa, and my thanks are due to the 

 director, Mr. A. F. Shira, and to Mr. H. L. Canfield, who aided me in every 

 way possible. I am also indebted to Mr. R. L. Barney, of the United States 

 Biological Station at Homer, Minnesota, for material sent me, and to Miss 

 EUzabeth Bodfish, of the University of Ilhnois, for many specimens from 

 Urbana localities. 



Through the kindness of Dr. Stephen A. Forbes, director of the IlHnois 

 State Laboratory of Natural History, I was able to learn something of the 

 conditions along the Illinois river at Havana and at Cedar Lake, having at 

 my command the facilities of the laboratory. I wish to express my deep 

 appreciation of these privileges. 



TECHNIQUE 



Collections were made in three ways. Surfaces or open water was dipped 

 up with a pail or jar, and as large amounts as possible carried back to the 

 laboratory, partly for the purpose of ascertaining whether or not specimens were 

 present, and partly for use in aquaria. Then with a long-handled dip net, 

 masses of algae and water-weed were taken either from shallow places 

 along the shore line, or from the surface out in deeper water where they float 

 in great tangles, or from the bottom. In some cases a good deal of water was 

 drained off and the mass of damp weed carried in, to be later plunged in pond 

 or tap water. As a third method, a mass of the alga was taken with a minimum 

 of disturbance and kept as nearly as possible in its relative shape and con- 

 dition. In small ponds where the water was not over three feet in depth, col- 

 lections were made out in the middle and often the leaves and stems of water 

 lilies and other large plants were gathered. These were kept by themselves 

 in clear water. The stems and undersides of the lily pads were generally cov- 

 ered with very fine algae or a growth of diatoms, which made good shelter 

 and feeding ground for many small forms. The bottom mud with its loose 

 covering of organic debris was generally dipped up separately with a small 

 amount of water. Samples were taken both near shore and out in the deeper 

 portions. 



Many collections were kept alive in the laboratory for lengths of time 

 varying from a few days to six months. The algae and other debris were 

 floated out in tap water, rain water, or pond water. Glass jars were used for 

 this purpose, some very shallow and some eighteen inches deep. In cases 

 where a few individuals or a special bit of water weed was to be isolated, 

 shallow glass stender dishes were employed. About half the aquaria were kept 

 covered to prevent evaporation and the others left open, water being added at 



