PLATE 18. 



Figs. 1^. Slrophoincnia opliidiana X 24. Figs. 5-12. S. triangularis. X 55. Fig. 13. S. 

 farcimen. X 60. 



Fig. 1. Cross section of S. ophidiana along line D of fig. 5, p\. S. 



Figs. 2, 3, 4 of same species are along lines, E, F, G, fig. 1, pi. 9. 



Figs. 8, 12, 10, 11 of S. triangularis correspond to lines D, E, F, G, fig. 3, pi. 9. 



Figs. 5, 6, 9 correspond to lines A, B, C, fig. 6, pi. 36. 



Fig. 7. Section through mid gut behind pharynx. 



Fig. 13. Section tlirough mid gut of S. farcimen in region of salivary glands. 



