PLATE 24. 



Figs. 1-5, 11. .Seotion.s of Ifhthyonicniii jiorosa. X 55. Fig. G-10, 12-14. Slroplionionia regu- 

 lari.s. X 55. 



Figs. 1, 4, 11 of I. porosa, correspond to linos B, C, A, fig. 6, p\. 5. 

 Figs. 2, 5 are along the lines E, D, fig. 1, pi. 6 (posterior end). 

 Fig. 3. Section tlirougli middle of body. 



Figs. 6, S, 9, 10, of S. reguluris, are along tlic lines, C, D, B, A in fig. 8, i)l. 20 (in fig. B read el in 

 place of ct). 



Fig. 7. Section of cuticle and h}'podermis of S. regularis. X 205. 



Fig. 12. Section through one sense organ of anterior end of I. porosa. X 555. 



Fig. -13. Section through one seminal receptacle and .several stalks of S. regularis. X 255. 



Fig. 14. Blood corpuscles of S. regularis. X 555. 



