PLATE VII. 



Spirifera oweni. 



Fig. 1-4, 7. Dorsal, profile, cardinal, ventral and front view of speci- 

 men. Page 126 



Fig. 5, 6. Lateral and dorsal view of a young specimen. 



Fig. 8, 9, 10. View of three specimens broken so as to show the 

 spiral cones. 



Spirifera conradana. 



Fig. 11, 12. Dorsal and ventral view of a specimen. Page 110 



Fig. 13. Dorsal view of a small specimen. 



Spirifera knappiana. 



Fig. 14. Ventral view of a specimen. Page 122 



