82 ILUNOJS BIOLOGICAL MONOGRAPHS [202 



EXPLANATION OF PLATE 

 Gordius robustus 

 Fig. 27. — ^Anterior end of adult male; dorsal view, drawn from alcoholic spcdmen; X 25. 



Fig. 28. — Anterior end of female, Leidy collection of 1879; dorsal view; drawn from alcoholic 



q>ecimen; X 25. 

 Fig. 29. — Section thru posterior aid of young male, showing jimction of q)erm ducts and 



intestine; X 360. 

 Fig. 30. — Male and female; early stage in process of mating; sketch from living specimens; 



XIO. 

 Fig. 31. — ^Male and female; just before discharge of sperm; X 10. 



Fig. 32. — ^Posterior end of adult male; ventral view; drawn from alcoholic specimen; X 40. 

 Fig. 33. — End view ot anterior end; drawn from alcoholic specimen; X 50. 

 Iig. 34. — ^Posterior end of adult female; end view; drawn from alcoholic specimen; X 50. 

 Fig. 35. — Early stage in the development of adult cuticula; X 480. 

 Fig. 36. — Cross section thru base of fork of male; adult cuticula not completely formed; shows 



canal passing from end of intestine to outlet in larval cuticula at tip of fork; X 120. 

 Fig. 37. — Sagital section thru postcloacal ridge of young male; X 140. 

 Fig. 38. — Structure of adult cuticula; X 440. 



