204 FISHES OF ILLINOIS 



upon the bottom much of the time, and when disturbed first dart 

 away to a little distance, and then bury themselves, tail down- 

 wards, in the mud with one or two quick twists of the body. They 

 have also the singular habit of burrowing into the mud when the 

 water evaporates from a pond. Professor Baird says that a locality 

 which, with the water perfectly clear, will appear destitute of fish, 

 will perhaps yield a number of mudfish on stirring up the mud at 

 the bottom and drawing a seine through it. Ditches on the plains of 

 Wisconsin, or mere bog-holes containing nothing else beyond tad- 

 poles, may thus be found full of mudfish. 



The intestine is short, less than the body in length, the gill-rakers 

 are thick and rather long, about half the length of the filaments, and 

 the pharyngeal apparatus is insignificant. The food of ten speci- 

 mens taken from six localities consisted largel}^ of minute duckweed 

 (Wolffia) and unicellular algae, insects and crustaceans making, how- 

 ever, more than a fourth of the food. The latter were mainly Ento- 

 mostraca. Thin-shelled univalve mollusks {Physa) were taken from 

 two of the specimens, and amphipod Crustacea (Crangonyx) from 

 one. Dr. Abbott reports that he has seen mud-minnows leap out 

 of the water a distance greater than their length to catch insects 

 resting on blades of grass. 



They apparently spawn in early spring, and Abbott reports that 

 in New Jersey he has found them appparently ripe on the 16th of 

 March, and that even earlier than this they were making their way 

 up stream in small brooks, leaping from eddy to eddy, evidently on 

 their way to their spawning beds. We have found ripe females dur- 

 ing the first week of April at Havana. Dr. Ryder says that their 

 adhesive eggs are laid singly upon the leaves of aquatic plants. 

 Those observed b}^ him hatched on the sixth day. 



This little fish is rather peculiarly distributed in Illinois, occur- 

 ring in our collections almost entirely in the extreme northern and 

 the extreme southern parts of the state. We have elsewhere taken 

 it only at Havana and Meredosia, on the Illinois River, where it has 

 occurred ten times in nearly eleven hundred collections. Its fre- 

 quency coefficients are correspondingly unequal for the three sec- 

 tions of the state, those for southern and northern Illinois being 1 . 48 

 and 1 . 28 respectively, while that for central Illinois is but . 23. We 

 have found it most frequently in lakes and ponds, and next in the 

 smaller rivers. 



It is a northern species, on the whole, ranging from Quebec and 

 Ontario throughout the basin of the Great Lakes to the Ohio, and 

 southward along the Atlantic as far as New Jersey, and northward 



