102 ILLINOIS BIOLOGICAL MONOGRAPHS [212 



f 



EXPLANATION OF PLATE 



Gordius robustus 



Fig. 105. — Cross section of nerve cord of adult; X 700. 



Fig. 106. — Nerve cord in specimen with adult cuticula nearly complete; X 340. 



Fig. 107. — Section near posterior end of male with fibrous cuticula nearly complete; X 120. 



Fig. 108. — Section thru anterior end of same specimen as Fig. 107; X 120. 



