I48 A. C. EYCLESHYMER AND J. M. WILSON. 



Explanation of Plate VII. 



Fig. 6. Sagittal section through an embryo a few hours older than that shown in 

 Fig. 5, showing one of the adhesive organs cut lengthwise. 



Fig. 7- Section through a single disk of the adhesive organ of a larva in which 

 both head and tail are free from yolk. 



Fig. 8. Section through a single disk of a larva about 8 mm. in length. 



Fig. 9. Section through a single disk of a larva about 9 mm. in length. 



Fig. 10. Section through a single disk of a larva about 14 mm. in length. 



Fig. 11. Section through a single disk af a larva about 20 mm. in length. 



