EXPLANATION OF PLATES. 



PLATE 53. PAGE 



ZAPHRENTIS ALVEOLATUS, N. Sp. 178 



FIG. 1 — Vertical section showing the funnel-shaped tabulae. 

 FIG. 2 — Lateral view of a fine specimen showing the tabulae and 

 lamellae. 



ZAPHRENTIS HALLI. Edwards and Haime. 179 



FIG. 3 — Posterior view exhibiting the calix. 

 FIG. 4 — Vertical section showing the tabulae. 



ZAPHRENTIS INTORTUS, N. Sp. 179 



FIG. 5 — Posterior view showing the distorted lamella* characteristic 



of the species. 

 FIG. 6 — Vertical section showing the oblique tabulae. 



HELIOPHYLLUM PARVULUM, N. Sp. 180 



FIG. 7 — Posterior view exhibiting the calix. 

 FIGS. 8-9 — Calix views of two different examples. 



