PLATE 2. 



Fig. 5. Longitudinal section from the oral wall of a tentacle. 



Fig. 6. Transverse section of pinnule. X 600. 



Fig. 7. Transverse section of a tentacle, showing the arrangement of the 

 muscles. X 85. 



Fig. 8. Longitudinal section of ectoderm of polyp wall. 



Figs. 9-12. Isolated ectoderm cells of polyp wall, drawn from maceration 

 preparations. 



Figs. 13-17. Ectoderm cells of tentacle isolated by maceration. 



Fig. 13. Two cover cells and a sense cell. 



Figs. 14, 15. Interstitial cells. 



Figs. 16, 17. Muscle cells of the ectoderm. 



Fig. 18. Longitudinal section of the ectoderm of polyp wall, in state of 

 expansion. 



Fig. 19. Section of ectoderm of the body wall of a polyp near the coenosarc. 



Fig. 20. Longitudinal section of polyp wall, partly contracted. X 600. 



Fig. 21. Longitudinal section of tentacle wall, aboral side. X 600. 



