PLAT|E XI. 



Figs. 1, 2, 3. — Pfychodus, sp. indet. 



Fig. 4. — Pfychodus occidentcdls Leidy, natural size. 



Fig. 5-S. — Pfychodus anomymus Willist., natural size. 



Fig. 9. — Pfychodus polygyi-us Buckl., a little enlarged. 



Figs. 10-15. — Pfychodus whippleyi Marcou, nearly natural size. 



Figs. 16-18, 20-22, 2i. — Pfychodus anonymus Willist., nearly natural size. 



Figs. 19, 23, 25, 26, -21. — Pfychodus, spp. 



