The Food of the Smaller Fresh- Water Fishes. 
8i 
Notemigonus chrysoleucus, Mitch. Shiner. 
This extremely abundant minnow, commonly called the shiner, 
occurs in all waters throughout the State, from the largest rivers 
to the smallest creeks, and from Lake Michigan to small stagnant 
ponds. 
The intestine is shorter than in any of the preceding species, 
although still rather long, the head and body being contained one 
and one-third times in its length. The gill-rakers are long, fine, 
and numerous, about twenty in number on the anterior arch, and 
fully one-third the length of the corresponding filaments, making, 
therefore, an effective apparatus for the separation of the Ento- 
mostraca from the water. As this fish presents a peculiar combi- 
nation of alimentary structures, and as its food was found unusu- 
ally various, a larger number of specimens were studied than of 
any of the species already discussed. 
Twenty-five fishes were dissected, from a great variety of sit- 
uations in all parts of the State, and representing various dates 
from May to September inclusive. As the food differed widely 
according to situation, that of specimens from certain localities 
being more widely different than the food of different species 
has usually been found, it will be best to mention the most con- 
spicuous differences depending upon situation. 
Specimens taken from the Pecatonica River at Freeport, an 
extraordinarily muddy stream, noted for the abundance of its 
mollusks, had eaten no other food than univalve Mollusca, chiefly 
Valvata tricarinata and Planorbis deflectus. Another, from the 
Illinois River at Pekin, had also eaten largely of mollusks, while 
three taken in Otter Creek in Jersey County, in almost stagnant 
reaches of the stream, extremely muddy, and green with Algae, 
had filled their intestines with mud, like Campostoma; and still 
others from ponds near Normal had eaten only Entomostraca, 
about equally Cladocera and Copepoda. Another specimen from 
the Illinois River had taken similar food, all Daphnias. One speci- 
men from Nippersink Lake, in the northern part of the State, was 
full of wild rice (Zizania). Taking all these groups together, and 
considering the species as a whole, besides the mud already men- 
tioned, about fourteen per cent, of the food consisted of mollusks, 
and only six per cent, of insects, nearly all of which were of 
