58 
Plate XI 
( Natural size) 
Zemistephanus vancouveri n. sp. (Page 20.) 
Figure 1. Section of whorls of holotype. National Museum of Canada, Cat. No. 9008. 
Figure 2. Side view, same specimen. 
Defonticeras? sp. (Page 17.) 
Figure 3. Oblique view of type. National Museum of Canada, Cat. No. 9014. 
