36 ILLINOIS BIOLOGICAL MONOGRAPHS [36 



lum cuticola, so heavily, in fact, that the fish often appear entirely black 

 in color. 



28. Hyborhynchus notatus (Raf.). Blunt-nosed Minnow. 



One of the very commonest of the local minnows, found in nearly 

 every lake and every stream. It shows little preference as to lake or stream 

 habitat, but is distinctly more abundant in clear than in muddy water. 

 It prefers the shallows, seldom venturing into water more than three feet 

 in depth, and in the lakes, at least, is most often taken in water of a foot or 

 eighteen inches in depth. The fish breed in June, though I have found 

 females carrying eggs well into July. The eggs are laid on the underside 

 of stones, cans, boards, or even pieces of paper provided the material is 

 not actually buried in the bottom. How the eggs are deposited in this 

 position I can not say. I have taken many nests along the shores of 

 Golden and Oconomowoc lakes, with invariably one of the parents on 

 guard, usually the male, as can be told by the group of tubercles on the 

 snout. The eggs hatch in eight or nine days in water varying from 70° to 

 75°F. The fish are used abundantly as bait for bass, perch and silver bass. 



29. Semotilus atromaculatus (Mitchill). Horned Dace; Chub. 

 Abundant in the Ashippun, Oconomowoc, Bark and Fox rivers, together 



with such of their tributary streams as afford congenial environment. Very 

 gregarious, these minnows are found in schools of many hundreds, or at 

 times thousands, in streams of moderately swift water and gravel bottom. 

 During the warm weather, when the water level of the streams lowers, the 

 minnows retire to the deeper holes, from which they are easily caught on 

 hook and line with small angle worms as bait. Breeding occurs in early 

 June, nests being constructed of much the same type as those of Camposto- 

 ma anomalum with which they are frequently associated. This species, 

 together with Hybopsis kentuckiensis, is the best bait available for bass, 

 pike and pickerel, and many thousands are captured in the glass minnow 

 traps for this purpose every year. So long has this been going on that the 

 species is in danger of extermination in the not far distant future. A very 

 game minnow, they feed on animal matter entirely, a large part of the food 

 being insects which fall upon the water. 



30. Clinostomus elongatus (Kirtland). 



This exquisite fine-scaled minnow has been taken by me only in the 

 Menomonee river, and is therefore represented only in the Lake Michigan 

 drainage area. In this river it is associated with Pimephales promelas 

 and Hybognathus nucha lis, inhabiting slightly muddy water of 18 inches 

 depth and little current. The species is not common, and I have taken only 

 10 specimens. The food consists of entomostraca, with a few insects and 

 insect larvae and quite a bit of algae (Spirogyra). The spawning apparently 

 occurs in June as I have a specimen heavy with eggs taken June 14. It is 

 rather surprising to find this species so far west; until I obtained my 



