PLATE XXII. 



Figs. 1 to 12. CALLOPORA PULCHELLA, n. sp 283 



1 to 3. Three typical specimens of the natural size. 



4. Surface of the original of flg. 3 xg. 



5. One of the depressed spaces of same xis. 



6 and 7. Two fragments, one unusually slender the other thicker than usual. 



8. Portion of the original of flg. 7 where the walls are thinner and the mesopores larger than 



usual, xis. Other parts of its surface more as shown in flg. 5. 



9. Vertical section xis. 



10 and 11. Average tangential section xis and small portion of same xso. 



12. Transverse section, natural size and one fifth of it xis. Note comparatively small size 



of the tubes in the axial region and wide peripheral region. 

 Upper third of the Trenton shales, St. Paul. 



Figs. 13 to 17. CALLOPORA PULCHELLA, var. PERSIMILIS, n. var 284 



13. Two fragments showing the exceeding prominence of the monticules. 



14. Portion of the surface between the monticules xi8. 

 15 and 16. Vertical and tangential sections xis. 



17. A transverse section, natural size and portion of same xis. 

 Upper third of the Trenton shales near Cannon Falls. 



Figs. 18 to 23. CALLOPORA CRENULATA, n. sp 284 



18. A fragment of the zoarium of this species, natural size. 



19. Surface of same xg. 



20. Average tangential section xis. Another, representing a more matured condition, 



rather closely resembles flg. 10. 



21. Vertical section xis. 



22. Several tubes from the axial region of same x]8, showing the wavy character of the walls. 



23. Portion of one of the maculae and adjacent parts of a specimen that preserves the cen- 



trally perforated zorecial closures, xi8. 

 Upper third of the Trenton shales, St. Paul. 



Figs. 24 to 31. CALLOPORA UNDTILATA Ulr f 279 



24 and 25. Typical specimens of the natural size. 



26. A fragment with rounded monticules. These are too prominent in the figure. 



27. Nearly smooth fragment, in this respect approaching C. incontrwersa. 



28. Surface of the original of flg. 25, xg. 



29. Tangential section xis. 



30. Portion of a transverse section xis. 



31. Vertical section xis. 



Middle third of the Trenton shales, St. Paul and Minneapolis. 



Figs. 33 to 36. CALLOPORA INCONTROVERSA UJr 278 



33. Tangential section xis, representing part of one of the clusters of large zocecia and a 



few of those of the ordinary size. Compared with C. undulata (flg. 29) it will be noticed 

 that they are of more rounded shape. 



34. The central part of a transverse section xis 



35. The axial part of a vertical section xis. At the right upper corner one of the tubes is 



drawn to its aperture. 



36. An entire but rather short zocecial tube xis, showing the distribution of the diaphragms. 

 Lower third of the trenton shales, Minneapolis. 



Figs. 37 to 41. CALLOPORA ANGULARIS, n. sp 277 



37. Fragment of the natural size. 



38. Vertical section xis. 



39. Tangential section showing fully matured characters, xis. 



40. Small portion of another tangential section xis showing the slightly irregular character 



of the cells at a deeper level in the zoarium than that represented in flg. 39. 



41. (14 on some of the plates.) Axial region of a transverse section xis. 

 Lower third of the Trenton shales, Minneapolis. 



