EXPLANATION OF PLATES, 



PUflTE 21. PAGE 



GOMPHOCERAS STRIATUM, N. Sp. (Rowley.) 58 



FIG. 1. — Front view of the aperture. 



FIG. 2. — Ventral side view of same specimen. 



FIG. 3. — Dorsal side view of same individual. 



FIG. 4. — End view of the last septum preserved, show- 

 ing the lateral position of the siphuncle, 

 same specimen. 



GOMPHOCERAS BELLATULUM. N. Sp. (Rowley.) 58 



FIG. 5. — Front view to show the size and shape of the 

 aperture. 



FIG. 6. — Outer. surface of the first chamber wall of an- 

 other specimen, showing the ventral position 

 of the siphuncle. 



FIGS. 7-8. — Dorsal and ventral views respectively of 

 another specimen, 



GOMPHOCERAS FACETUM,N.Sp. (Rowley.) 58 



FIG. 9. — Front view of the large, almost V-shaped, ap- 

 erture. 



FIGS. 10-11. — Ventral and dorsal views of another 

 specimen. 



FIG. 12. — Posterior end view of the same, showing the 

 position of the siphuncle. 



GOMPHOCERAS OVIFORME? Hdl Sp. Rowley. 59 



FIG. 13. — Lateral view of an internal cast from chert. 

 FIG. 14. — Cross section to show elliptical outline. 



CRANOCERAS? ELLIPTICUM, N. Sp. (Rowley.) 59 



FIG. 15. — Side view of an internal cast. 

 FIG. 16. — End view of the same. 



(Continued on next page-) 



