PLATE XXV— Concluded. 

 Fig. 18. Bellerophon (Bucania) Exiguus Foerste 548 



18. a. View from above, b. Side view. The umbilicus here is very small. H. O. Marl. 



Fig. 18. Bellerophon (Bucania) opertus Foerste 548 



18. Not the type ; the umbilicus in the cast is larger than in B. exiguus. c. Lateral view. 



d View almost from in front. H. O. Marl. 



Fig. 19. Bellerophon fiscello-striatus Foerste 548 



19. a. Lateral view, the inner margin of the whorl not well shown, though the umbili- 



cus is large. 6. Front view. c. Upper view. d. View showing sinuous outer lip 

 of aperture, e. A little of the carina and part of the adjacent striae, enlarged. 

 S. H. O. Stolz's quarry. 



Fig. 20. Orthis (Herbertella) Daytonensis Foerste 575 



20. a. Pedicle valve, b. Interior of the same. CO. 



Fig. 21. Orthis (Herbertella) Daytonensis Foerste 575 



21. A lateral view showing outlines of a perfect shell. CO. 



Fig. 22. PlaTyceras (PlaTystoma) Niagarense Hall 553 



22. A mature specimen, a. Side view. b. Top view ot spire. B. O. 



Fig. 23. Acidaspis ortoni Foerste 522 



23. Glabellar regions not correctly shown, and the spines of the free cheek should be a 



little longer. B. O. 

 Fig. 24. Calymene yogdesi Foerste 526 



24. Smaller specimens from the limestone. S. H. O 



Fig. 25. Calvmene vogdesi Foerste 526 



25. The type. C. O. 



Fig. 26. Lichas breviceps Hall 529 



20. a, b. Two glabella;, c. Surface enlarged. These specimens have lobes of consider- 

 able size in the occipital furrow not well shown in the figure beneath the lateral 

 lobes of the glabella. This distinction belongs to variety Clintovensis. S. H. O. 

 d. Pygidium. S. H. O. e. Part of a glabella, B O., belonging all to the same va- 

 riety. 



