26 JACOB REIGHARD. 



19. The caudal and anal fins of the two males may project 

 beyond those of the female so that their distal portions are 

 in contact with each other by their roughened surfaces (Figs. 



2,3)- 



20. The roughened surfaces of the males aid them to hold the 



female between them. 



21. By their contact with each other the roughened surfaces 

 of their caudals and anals may aid the two males to maintain 

 their positions with reference to each other. 



22. Spawning is accomplished during a rapid vibration in 

 unison of the bodies of all three fish. This agitates the bottom 

 material and causes its lighter parts to be swept downstream 

 by the current. 



23. During spawning milt is seen to spurt from the genital 

 openings of the males and cloud the w r ater. 



24. After spawning the fish separate and each may repeat the 

 act many times in various places and in combination with various 

 individuals. 



25. Small fish usually gather at once over the area in which 

 the spawning occurred and there crowd together in a small space. 



26. These fish root in the bottom with their snouts and appear 

 to be eating eggs that have just been buried. 



27. At each pairing act supernumerary males may be present 

 and may attempt to supplant those actually engaged in pairing 



(Fig. 4)" 



28. At the close of the breeding season, the pearl organs are 

 shed and both males and females become uniformly olivaceous in 

 color. 



29. Outside the breeding season the mature fish are not seen 

 on the rapids in great numbers but in Michigan are abundant in 

 lakes in deeper water. 



B. The Red-Horse (Moxostoma aureoleum). 



30. Red-horses congregate on the rapids in southern Michigan 

 in May in situations like those occupied by white suckers, but 

 not in streams as small as some of those in which the white 

 suckers breed. 



31. In both sexes at this time there is a white lateral stripe, 



