PLATE XXII. 



Page 



Figs.'l to 12. Callopoba pulchella, n. sp 28! 



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



4. Surface of the original of flg. 3 X9. 



5. One of the depressed spaces of same xi8. 



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, X18. Other parts of its surface more as shown in flg. 5. 



9. Vertical section xi8. 



10 and 11. Average tangential section xi8 and small portion of same x50. 



12. Transverse section, natural size and one flfth of it xi8. Note comparatively small size 



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

 Upper third of the Trenton shales, St. Paul. 



Pigs. 13 to 17. Callopoea pulchella, var. peksimilis, n. var 28i 



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 xi8. 



17. A transverse section, natural size and portion of same xi8. 

 Upper third of the Trenton shales near Cannon Falls. 



Pigs. 18 to 23. Callopoea ceentjlata, n. sp 284 



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



19. Surface of same xg. 



20. Average tangential section xi8. Another, representing a more matured condition, 



rather closely resembles flg. 10. 



21. Vertical section xi8. 



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 zooecial closures, xi8. 

 Upper third of the Trenton shales, St. Paul. 



Pigs. 24 to 31. Callopoea UKDtrLATA Ulr 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. incontroversa. 



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



29. Tangential section xi8. 



30. Portion of a transverse section xi8. 



31. Vertical section xi8. 



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



Figs. 33 to 36. Callopoba rsrcoNTKOVBKSA Ulr 278 



33. Tangential section xi8, representing part of one of the clusters of large zooecia 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 xi8 



35. The axial part of a vertical section xi8. At the right upper corner one of the tubes is 



drawn to its aperture. 



36. An entire but rather short zocecial tube xi8, showing the distribution of the diaphragms. 

 Lower third of the trenton shales, Minneapolis. 



Figs. 37 to 41. Callopoea angulaeis, n. sp 277 



37. Fragment of the natural size. 



38. Vertical section xi8. 



39. Tangential section showing fully matured characters, xis. 



40. Small portion of another tangential section xi8 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 xi8. 

 Lower third of the Trenton shales, Minneapolis. 



