20 THE UNIVERSITY SCIENCE BULLETIN. 



Such a catastrophe did not disturb the Gelastocorids, for they 

 were out again as soon as the waters sufficiently receded. 

 (Plate II shows a photograph of a western Kansas river.) 



Eastern Kansas. 



Collections were made in the pools and ponds about Law- 

 rence. Lake View, the largest standing body of water avail- 

 able, is six miles from the city. This occupies an abandoned 

 channel of the Kaw river, and is, in fact, an "oxbow" lake. 

 This strip of water is perhaps 150 yards across and a mile long, 

 fringed by willows along the sides and encroached upon at the 

 ends by cattail, scouring rush and other plants. A thorough 

 survey has never been made of this place. 



Haskell Pond : An artificial pond covering perhaps half an 

 acre. This pond has a muddy bottom and little vegetation. It 

 is fed by the runoff of the land and by a little intermittent 

 stream that has its origin in some springy ground in a mow- 

 land meadow above the pond. This stream, a mere ditch, over- 

 grown by tall marsh grass, contains several water holes that 

 have been good collecting for water bugs, especially for Belo- 

 stoma. 



Griesa Pond : A little dammed-up pool of very muddy water, 

 in extent perhaps, three rods long and two broad. This is lo- 

 cated in a five-acre lot and invaded by two or three cows in fly 

 time. Since the bottom consists of deep, fine silt these visita- 

 tions keep it ever turbid and filthy. It was in this pond that 

 the Ramphocorixa and the egg-burdened crayfish were most 

 abundant. 



Smith Pond: Of the same type as above, but less muddy, 

 being located in a pasture and so situated as to receive less 

 silt. It is more than three times the size of the Griesa pool, 

 and perhaps four feet in its deepest part. There are no seed 

 plants growing in the pool. Unicellular algae make its waters 

 green in midsummer. Entomostraca became exceedingly abun- 

 dant here one dry summer, and the pond was teeming with 

 thousands of the back-swimmers of the genus Buenoa. 



The Quarry Pools : Two temporary pools, occupying depres- 

 sions where limestone had been quarried, were visited one 

 season almost daily from earliest spring until they disappeared. 

 The two pools were quite different. One named the Cattail 

 pool was surrounded by cattail. Its waters were clear and 



