400 



Peoria Lakk. 1923 Comparkd with 1922. Av. Xos. per Sq. Yd. 



foot of Horshor Isl. 



Pkoria Lakk. 1923 Comparkd with 1922. Av. Nos. per Sq. Yd. 



• Foot of Horshor Isl. 



Numbers of midge larvae (Cliironomidae) in Peoria Lake dredgings 

 in 1023 as in li)22 were irrcs;ular and not apparently of great signifi- 

 cance. Only two species previously associated by us definitely with 

 polluliun were taken, and it was a little mystifying to find tbeni most 



