142 ILLINOIS ACADEMY OF SCIENCE 



feet wide and where the sand was thrown into many hori- 

 zontal ridges or "ripple marks." Here in two or three 

 inches of water a number of minnows of this species were 

 chasing others of the species that were probably females. 

 When one of these last would be overtaken it would be 

 given a blow on the side by the pursuer. This may have 

 effected spawning. Evidence of this was the finding of 

 young in an aquarium over some sand gathered from 

 beneath a place where I saw this apparent spawning take 

 place. Evidently they hatched from eggs in this sand. Two 

 of these fish were reared : one to a length of % inch 

 (August 5, '09) and one to I14 inches (December, ^909). 



Both were sufficiently large for positive determination. 



None of the ripe fish, males or females, taken by me had 

 pearl organs or special noticeable breeding markings of 

 any kind. This is in accordance with the observation of 

 Jordan ('82, p. 855), who says that the males do not 

 undergo any special changes in color or form during the 

 breeding season. 

 Hyhopsis kentiickiensis (Rafinesque), River Chub. 



Structures that were undoubtedly nests of this species 

 were found in Flat Branch (Fig. 4), about two miles east 

 of Humboldt, Illinois. These were low, round conical piles 

 of small stones (Fig. 5), mostly from I/2 inch to 1^2 

 inches in diameter. The piles varied at their bases from 

 about 6 by 8 inches to 10 by 20 inches and were from about 

 2 to 8 inches in height; this last dimension was evidently 

 determined by the depth of the water. The fish appeared 

 to build till the stones were near the water surface. 

 The nests were found June 14, 1912; June 14, 

 1913, and May 14, 1914, but all had evidently been com- 

 pleted. Forbes and Richardson ('09, p. 169) give the 



breeding time of the species as late May and early June, 



The part of the creek where the nests were found ran 

 through a piece of pasture where there were cattle and 

 hogs; the latter frequently roiled the water. The stream 

 was here mostly about fifteen feet wide and shallow, almost 

 everywhere under a foot in depth, but there were overhang- 

 ing Ibanks which gave good concealment for the nesting 

 fish. The bottom was of firm, light-colored, mixed clay and 

 gravel. The temperature readings made on the dates the 

 nests were found were from 67 °F. to 82° P. 



