PLATE XXI. 



Fig. I. Campa7iulina rugosa Nutting. Part of colony, showing hydrothecse and 

 gonangia (enlarged). 



2. Gonangium, showing developing medusa (enlarged). 



3. Lafoea ad/icerens Nutting. Part of trophosome (enlarged). 



4. Part of transverse section of gonosome (enlarged). 



5. Grammaria inimeisa Nutting. Part of main stem (enlarged). 



6. Portion of branch with the peripheral tubes removed to show connection 

 of hjdrotheciE with axial tube (more enlarged than fig. 5). 



(206) 



