PLATE VI. 

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



. I. Clytia caliculata (Hincks). Single hydrotheca (enlarged). 



2. Another hydrotheca (enlarged). 



3. Clytia compressa (Clark). Hydrothecae (enlarged) showing different 

 degrees of thickening of the hydrothecal walls. 



4. Single gonangium (enlarged). 



5. Campanularia ritteri Nutting. Part of colony (enlarged). 



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