EXPLANATION OF PLATES. 



PLOTE 13. PAGE 



CYSTIPHYLLUM INVAGINATUM, N. Sp. 34 



FIG. 1. — Lateral view of a large specimen. 

 FIG. 2. — Calix view of another example. 



HELIOPHYLLUM SHERZERI, N. Sp. 34 



FIG. 3. — Lateral view of a large specimen. 



FIG. 4. — Calix view of another large example. 



FIG . 5. — Calix view of another smaller individual. 



FIG. 6. — Lateral view of another smaller specimen. 



HELIOPHYLLUM MINUSCULUM, N. Sp. 35 



FIG. T. — Posterior view. 



F X G . 8. — Calix view of another individual. 



ZAPHRENTIS GROSBACHI, N. Sp. 36 



FIGS. 9-10. — Lateral views of different individuals 

 showing the proliferous growth. 



FIGS. 11-12. — Calix views, of two different exam- 

 ples, showing the smooth, convex space, in 

 the center of the calix. 



