EXPLANATION OF PLATES, 



FL.f\TE 17. PAGE 



ACROPHYLLUM RUGOSUM, N. Sp. 48 



FIG. 1. — Lateral view of a mature specimen with a 

 portion of the calix broken away to show the 

 conical elevation. 



FIG. 2. — Lateral view of another matured example. 



FIG. 3. — Lateral view of another individual with a por- 

 tion of the calix broken away to show the coni- 

 cal elevation and the lamellae. 



ZAPHRENTIS LAMASTERI, N. Sp. 44 



FIG. 4. — Posterior view showing the smooth flat space 

 in the center of the cup and the lamellae. 



FIG. 5. — Oblique posterior view of another example 

 exhibiting the smooth tabula3 and the fossette. 



CYSTIPHYLLUM EXPANSUM, N. Sp. 45 



FIGS. 6-7-8. — All three views of the calix from differ- 

 ent specimens. 



CYSTIPHYLLUM DIVERSUM, N. Sp. 46 



FIG-. 9. — View of a longitudinal section of a matured 



specimen. 

 FIG. 10. — Calix view of another example. 



