PLATE 50. 



Fig. 1- IS. 606. 1. Callocystites jEWETTir. ( Pag. 239.) 



1. The posterior side, showing the ovarian aperture destitute of plates closing it. 



2. The right side, showing the pectinated apertures. 



3. The anterior side, showing the pectinated apertures near the base, and the position of the intercalated 



quadrangular plate. 



4. View of the base, showing the large foramen opening from the column, 



5. A portion of the base of the arm plates on the left side. 



6. Two plates from the right side of the body, enlarged, showing the relative form and proportions of the 



pectinated apertures. 



7. One of these pectinated apertures still farther enlarged, and defining more clearly the transverse bars and 



the spaces between. 



8. A portion of the surface enlarged, showing the polygonal spaces, which are separated by scarcely elevated 



ridges. 



9. The structure and arrangement of the arms and plates composing them. 



9 a. A portion of an arm with the tentacula attached from another specimen. 

 9 6. The same enlarged. 10. The bases of the arms enlarged. 



11. The structure of the body, including the first and second series of plates, and a part of the tliird series. 



12. An individual having a slightly different form. 



13. The arms spread out in a plane, and showing their relation to the ovarian and pectinated apertures. 



14. Section of the column, showing the large canal. 



15. A portion of one of the arms enlarged, showing the sinuated groove, with the bases of tentacula marked 



b b. 16. The granulated surface of the plates of the arm magnified. 



17. A fragment of a column very similar to that attached to the body fig. 12. 



18. An enlargement of the same, showing the crenulated edges of the joints. 



Fig. 19 - 29. Fragvients of cohimns of Cystidem. ( Pag. 242.) 



19. Several joints of a column, near the base, having the joints connected and retiexed, with the margins 



strongly crenulate. 



20. An enlargement of two joints from the preceding figure. 



21. A fragment of a column where the joints are composed of interrupted plates, which extend only a short 



distance, gradually thinning away, and being overlaid by the thin edge of another one. 



22. An enlargement of the same. 



23 & 24. A fragment of a column with the joints carinated and reflexed on their outer margins, and finely 



crenulate. 



The separate plates figs. 2-5 and 26, 27 and 28, belong to the same or a similar species. The exterior 



surface of 27 is covered with a minute coral like Aulopora, and the ornament has been obliterated. 



Fig. 28 is the inside of the same plate, showing concentric lines of growth. 

 29, An enlargement of the small branching coral on flg. 27. 



