PLATE XXm. 



Fig. I. Halecium reversum Nutting. Part of colony, showing internodes and 

 hydrophores (enlarged). 



2. Single hydranth with hydrophore (enlarged). 



3. Halecium robusium Nutting. Tip of branch, showing expanded 

 hydranths (enlarged). 



4. Part of branch with soft parts removed to show the hydrophores (en- 

 larged). 



5. Single hydranth with its hydrophore (greatly enlarged). 



(210) 



