HYBOPSIS 169 



Pennsylvania and southward to North Carolina and Alabama, our 

 collections in the state of Illinois are limited to the more recently 

 glaciated areas, only one having been made by us below the south- 

 ern boundary of the Wisconsin glaciation. Against this single lo- 

 cality in southern Illinois (Union county) we have 122 localities in 

 the northern two thirds of the state, where the species is not only 

 abundant but is generally distributed, mainly in the smaller streams 

 and also in the glacial lakes of the northeastern section. We have 

 taken it from Lake Michigan at Chicago. 



According to our 137 collections of the horny-head, it is almost 

 wholly a species of the creeks and smaller rivers, the frequency 

 coefficient for the first being 3.08 and for the second 2.47. It has 

 been so rare in stagnant waters that we have taken it but twice 

 in our 591 collections from lakes and ponds. From the larger 

 rivers we have obtained it 6 times in 293 collections. It seems to 

 be with us especially a fish of swift waters and a hard bottom, the 

 coefficient for the former class of situations being 1.38 and for the 

 latter 2.24. It is consistent with this fact that, although commonly 

 scattered throughout the Wisconsin glaciation, it stops short at 

 the southern boundary of this area , not entering the lower Illinoisan 

 at any point. 



The spawning season of this species is late May and early June. 

 In spring males the top of the head is swollen to form a kind of crest, 

 which may be considerably higher than the level of the neck, and is 

 covered with large tubercles. 



The length of ten inches which this fish sometimes attains, per- 

 haps accounts for the rather prominent appearance of crawfishes 

 in its food. Thirteen specimens from northern and central Illinois 

 had derived less than half their food from the animal kingdom, 

 about a fourth of it consisting of insects, largely case-worms and 

 other larvae of Ncuroptera, another fourth of crawfishes, eaten by 

 two of the specimens. The vegetable food was about equally di- 

 vided between thread algas and seeds of grasses. Although insects 

 appear in relatively small ratio, two of these fishes had eaten noth- 

 ing else, and another had eaten 95 per cent, of aquatic larvae. Two 

 other specimens had taken only vegetation, which also composed 

 80 per cent, of the food of three additional. It will be noticed that 

 the alimentary canal of this minnow is of more than average length, 

 a fact probably related to its vegetarian habit. As a game fish, 

 according to Jordan and Evermann, it is the most active and vigor- 

 ous of its tribe. 'Any sort of hook baited with an angleworm 

 or white grub is a lure the hornyhead can seldom resist, and he bites 



