ILLINOIS BIOLOGICAL MONOGRAPHS 



VOLUME 3 



305«Kp 306 /"/ S"4°P1'«* ,^, 



Conop, Chloropisca '^ 3U ' 3U» Hydrou.:. 3O9 A„by,„ 310s.,cophi«. 



PF.TF.RSOX HEAD AND MOUTH PARTS OV DIPTRRA PLATF. XIII 



