EXPLANATION OF PLATES. 



PLATE 46. PAGE 



BLOTHROPHYLLUM HOUGHTON!. 156 



FIG. 1 — Ij^teral view of a large corallum, from the Hamilton group 

 of Genflessee county, New York. 



FIGS. 2-3 — Lateral views of two specimens, from the Hamilton 

 group, of Clark county, Indiana. 



FIG. 4: — Anterior view of a small corallum, from the Hamilton group, 

 of Crab Orchard, Kentucky. 



ZAPHRENTIS PROLIXUS, N. Sp. 156 



FIGS. 5-6 — Posterior views of two eorallums. Natural size. 



HELIOPHYLLUM VESICULATUM. 157 



FIGS . 7-8 — Posterior views exhibiting the calix. 



FIGS. 9-10-11-12 — Views of the calix of four different eorallums. 



