PLATE XXI. 



Placbnticeras occidentale (page 155). 

 Figure 1. Side view of the type of this species from the K-uk River, B.C. 



SCAI'HITES QUATSIN0EN8IS (pUgC 158). 



Figure 2. Side view of the most perfei^t specimen of this species yet collected, 

 from the east side of Winter Harbour, Quatsino Sound. 



DisoiNA pileoll;s (page 159). 



Figure :!. View of the most perfect of the two dorsal valves collected, as seen 



from above.. 

 Figure 3^'. Lateral view of the same, in outline only, to shew the relative 



height of the valve. 



Cyprina Yukonensis (page 160). 



Figure 4. Side view of a right valve of this species. 



SOHLOENBACHIA BOREALIS (page 160). 



Figure 5. Side view of the largest and most perfect specimen of this species 



yet collected. 

 Figure 6- View of an Aptychus found associated with S. horealis. 



BSTHERIA BELLULA (page 162). 



Figure 7. Side view of the type of this species. Twice natural size. 

 Figure 7a. Side view of the left valve of a shell supposed to be referable to E. 

 hellula. Twice natural size. 



