PLATE IX. 



[Proc. Wash. Acad. Sci., Vol. Ill, PI. XX.] 



Fig. I. Obelia dubia Nutting. Part of colony (enlarged). 



2. Gonothyrcea inornata Nutting. Part of colony, showing hydrothecae 



and gonangium (enlarged). 

 3 and 4. Gonangia (enlarged). 

 [204] (222) 



