PLATE XZ. 



Pinna calamitoides, Shumard (page 167.) 

 Figures 1,1a and 1 b. Three detached fragments of this species. 



Inoceramus undulato-plicatus, Eoemer (page 168.) 



Figure 2. Right valve of a young but perfect specimen. 

 " 2 a. Left valve of another immature shell. 



Inoceramus mytilopsis, Conrad (page 169.) 

 Figure 3. Left valve of an aberrant form of this species. ' 



Inoceramus Vancouverensis, Shumard (page 170.) 



Figure 4. Left valve of a specimen whose length and height are nearly equal. 

 " 4 a. The most common form of the species, in •which the height considerably 



exceeds the length. 

 " 4 b. Umbonal region of a specimen whose beaks are abnormally developed. 



Anomia Vancouverensis, Gabb (page 175.) 



Figures 5 and 5 a. Two upper valves, which retain the markings of some ribbed shell 

 on which they have grown. 

 " 5 b. An upper valve, showing the true surface markings. 

 " 5 c. Side view of the same, to shew the amount of convexity. 

 " 5 d. Minute radiating striaa of the test, highly magnified. 



DisciNA Vancouverensis (page 177.) 

 Figure 6. Upper valve of the type specimen. 



Smilotrochus Vancouverensis (page 178.) 



Figure 7. Side view of the only specimen. 



« 7 a. Transverse section of the same, at or near the summit. 



