PLATE VI. 

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



Tig. I. Clytia calicnlata (Hincks). Single hydrotheca (enlarged). 



2. Another hydrotheca (enlarged). 



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

 degrees of thickening of the hydrothecal walls. 



4. Single gonangium (enlarged). 



5. Campanularia riiteri 'i^utiinQ. Part of colony (enlarged). 

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