VIII LIST OF ILLUSTHATIONS. 



Page. 

 Fig. 11. Corynotrypa abrupta. a and 6, portions of the type-specimen, X 9 



and X 20 66 



12. Corynotrypa abrupta. a and b, portion of a zoarium, X 9 and X 20, 



incrusting a crinoid column 66 



13. Corynotrypa schucherti. a and b, portions of the type-specimen, 



incrusting a Streptelasma, X 9; c, several zocecia of the same, 



X 20 67 



14. Corynotrypa dissimilis. a and b, a typical example of the species, 



X 9 and X 20, incrusting the epitheca of the bryozoan Diplotrypa 

 nummiformis; c and d, poorly preserved specimen of the species, 

 X 9 and X 20, growing upon a specimen of Heliolites 68 



15. Mitoclema boreale. Fragment of a zoarium, X 9 70 



16. Mitoclema? mundulum. a and 6, fi'agments, natural size, and 



X 9; c, original of b, X 18, showing surface character. (After 

 Ulrich.) d, portion of young example, X 9 70 



17. Protocrisina exigua. a to e, Wiman's views of Crisinella oeilensis. 



a, fragment, natural size; b, celluliferous surface, X 10, showing 

 the circular zooecia and accessory pores; c, noncelluliferous face, 

 X 10; tZand e, two transverse sections, X 10. ftoi, Ulrich 's views 

 of Protocrisina exigua. /, two fragments, natural size; g, cellu- 

 liferous face, X 18, with zooecial openings and accessory pores; 

 h, noncelluliferous side, X 18, with pores; i, transverse section, 

 X 18 72 



18. Protocrisina ulrichi. a, portion of a zoarium, natural size; b, another 



fragment, showing the noncelluliferous side, natural size, and 

 enlarged eight diameters; c, celluliferous side of another fragment, 

 X8 74 



19. Ceramopora spongiosa. a, portion of a zoarium, natural size; b and c, 



tangential section, X 9, and portion of same, X 20; c7, tangential 

 section of three zocecia, X 20; e and/, vertical sections, X 9 and 

 X 20 77 



20. Ceramopora invenusta. a, tangential section, X 20; b, tangential 



section, X 20; c, vertical section, X 20, through a zoarium 79 



21. Ceramopora in tercellata. a, edge view of the fragmentary type, X 1 ; 



6 and c, tangential section, X 20, and a portion, X 35; d, vertical 

 section, X 20, through one layer of the zoarium 80 



22. Ceramoporella granulosa minor, a, tangential section, X 20; b, ver- 



tical section, X 20, through a single layer of zooecia 82 



23. Ceramoporella uxnormensis. a and b, tangential section, X 20 and 



X 35; c, vertical section, X 20 83 



24. Coeloclema crassimurale. a, fragment of a zoarium, natural size, with 



end view of the same showing the central tube; b, tangential sec- 

 tion, X 20; c, vertical section, X 20, through one side of a zoarium. 84 



25. Coeloclema laciniatus. a, Eichwald's type-specimen, natural size, of 



Coenites laciniatus; b, surface of the same, enlarged 85 



26. Crepipora schmidti. a, vertical section, X 20; b, tangential section, 



X20 87 



27. Crepipora lunatifera. a, the type-specimen, incrusting Hormotoma 



insignis (Eichwald), two-thirds natural size; 6, view of the zooecia 

 at the surface, X 9; c and d, tangential sections, X 20 and X 35, 

 illustrating zooecial structm'e; e, vertical section, X 20, through 

 the zoarium 88 



28. Crepipora incrassata. a, edge view of the type-specimen, natural 



size; b, tangential section, X 20; c, vertical section, X 10, cut- 

 ting two layers of zocecia: d, portion of a vertical section, X 20... 90 



