THE WATER-CRESS SOWBUG. 15 



are the fresh-water killifishes Funduln.'i notatus, F. diaphanus, and F. disimr. 

 The first occurs from Michigan to Alabama, Mississippi, and Texas, and is 

 rather common in small lowland ponds. The second is found from Maine to 

 North Carolina in river mouths, in the Great Lakes, and in practically all of 

 the small lakes in the upper Mississippi Valley. The third occurs in smaller 

 lakes and p(mds from northern Ohio to Illinois and south to Mississippi. 

 Specimens of each of these species could be obtained at any one of several 

 small lakes in the northern part of Indiana. 



It is probable that some of the catfishes might also be useful in this connec- 

 tion, and it is suggested that it might be worth while to try one or more of 

 the small species known as " mad Toms," belonging to the genus Schilbeodes. 

 One or more species of this genus can be found in almost any small, sluggish 

 stream in Pennsylvania, Virginia, and West Virginia. 



The writer believe.s that carp should prove of value in keeping 

 down this cress sowbug, there being one drawback, however, that the 

 carp must be watched to see that they do not develop too raj^idly 

 and that they do not attack the cress or make the water mudd}'. Cat- 

 fish have been tried and found wanting in the case of the water-cress 

 leaf-beetle, which will be considered elsewhere (pp. 10-20). 



