EXPLANATION OF PLATES. 



Figure 4. — Pelvis of Camptonotus dispar Marsh (one twelfth 

 natural size) : «, acetabulum ; other letters as in Figure 5. 



Figure 5. — Hind leg of same (one twelfth natural size : letters as 

 in Plate I. 



Figure 6. — Fore leg of same (one twelfth natural size). 



PLATE IV. 



Cretaceous Bird, Hesperornis regalis Marsh. — Page 466. 



Figure 1. — Restoration of skeleton (one eighth natural size). 



Figure 2. — Left lower jaw : top view (one half natural size). 



Figure 3. — The same : side view. 



Figure 4. — Tooth (four times natural size). 



Figure 5. — Twentieth vertebra, dorsal : side view (one half natural 

 size). 



Figure 6. — The same : front view. 



Figure 7. — Pelvis: side view (one fifth natural size); a, acetabu- 

 lum ; il, ilium ; is, ischium ; p, pubis ; p f , post-pubis. 



PLATE V. 



Cretaceous Bird, Ichthyornis of Marsh. — Page 466. 



Figure 1. — Restoration of Ichthyornis victor Marsh (one half 



natural size). 

 Figure 2. — Left lower jaw of Ichthyornis dispar Marsh: side 



view (twice natural size). 

 Figure 3. — The same : top view. 

 Figure 4. — Cervical vertebra of Ichthyornis dispar Marsh : side 



view (twice natural size). 

 Figure 5. — The same : front view. 



PLATE VI. 



Eocene Mammal, Coryphodon of Owen. — Page 502. 



Figure 1. — Outline of skull and brain-cavity of Coryphodon ha- 

 matus Marsh : top view. About one fifth natural size. 



Figure 2. — Cast of brain-cavity of Coryphodon hamatus : top 

 view (one half natural size). 



Figure 3. — Left fore foot of Coryphodon (one third natural size). 



Figure 4. — Left hind foot of Coryphodon (one third natural size). 



