PLATE 3. 



Fig. 22. Section through the coenosarc to show cords of interstitial 

 cells. X 67. 



Fig. 23. Section of epidermis of coenosarc. 



Fig. 24. Ectoderm of coenosarc in the region shown in Figure 26. 



Fig. 25. Section of decalcified spicule, showing spicule-producing cells. 



Fig. 26. Outline of portion of coenosarc between polyps, to show the 

 distribution of supporting fibers and of nettle batteries. X 67. 



Fig. 27. Section to show mesogloea. 



Fig. 28. Section showing mesogloea cells. X 400. 



Fig. 29. Section of "a cord" in mesogloea of coenosarc. 



Fig. 30. Longitudinal section of epitheUum (ectodermal) Hning the stomo- 

 daeum and of mesogloea. 



Fig. 31. Longitudinal section of the wall of stomodaeum, showing both 

 ectoderm and mesogloea. 



Fig. 32. Transverse section of a part of siphonoglyph. 



Fig. 33. Transverse section of a portion of a mesentery. 



