EXPLANATION OF PLATE XVII. 



All tbo tigiires of tUo natural size, except Figs. 9, 10. 



Fig. 1. Clupea IIU5IILIS. From the original specimen obtained by Dr. John E. Evans, on Green River, 

 in 1806. 



Fig. 2. Clupea alta. From the "Petrified Fish Cut," on the Union Pacific Railroad, near Green River. 



Fig. 3. Petalodus allegh-vniensis. Tooth, front view, from a specimen obtained by Messrs. Meek and 

 Hayden, in the ni^iier carboniferous formation of Fort Riley, Kansas. 



Figs. 4-6. Cladodus occidentalis. Tooth found by Messrs. Meek and Hayden, in the upper coal 

 measures of Manhattan, Kansas. 

 Fig. 4. Back view. Fig. 5. Section of the crown. Fig. 6. Bottom of the root. . 



Figs. 7, 8. PTYcnoDUS occidentalis. Tooth discovered by Dr. John L. Le Coute, in the Cretaceous 

 formation east of Fort Haj's, Kansas. 

 Fig. 7. Upjier view. Fig. 8. Lateral view. 



Figs. 9, 10. XiPHACTiNUS AUDAX. A pectoral .spine, one-half the natural size. 

 Fig. 9. Inferior view. Fig. 10. Superior view. 



Figs. 11-17. Myi.ocypeinds robustus. Pharyngeal bones, from Idaho, contained iu the collection of 



Professor J. S. Newberry. 

 Fig. 11. Interior view of a left pharyngeal, containing the three intermediate teeth. 

 Fig. 12. Inferior view of a right pharyngeal, containing the anterior three teeth. 

 Fig. 13. Same view of a smaller left pharyngeal, with the posterior four teeth. 

 Fig. 14. Similar view of another specimen, with the anterior three teeth and the bases of 



the posterior two teeth. 

 Fig. 15. Posterior view of a right pharyngeal of an old auimal, with the second aud fourth 



teeth. 

 Fig. 16. Inner view of a right pharyngeal, with the posterior four teeth. 

 Fig. 17. Posterior view of the same siiecimen. 



Figs. 18, 19. Oncobatis pentagonus. Dermal plate, from the Pliocene of Sinker Creek, Idaho. 

 Fig. 18. Upper view. Fig. 19. Lateral view. 



Fig. 20. Enchodus Shujiaedi. Dentary bone, natural size, but reversed iu position. From the Cre- 

 taceous of Dakota. 



Figs. 21, 22. Cladocyclus occident^vlis. Two scales, natural size. Found with the preceding. 



Figs. 23, 24. Phasganodus dirus. From Cannonball River, Dakota. 

 Fig. 23. A tooth of the natural size. 

 Fig. 24. Dentary bone, reduced one-third. 



Fig. 25. Xystracantiius arcuatus. A dorsal spine, from Leavenworth, Kansas. 



Fig. 26. Hadrohy^u.s .suprbjius: 



The mutilated crown of an upper premolar tooth, natural size, seen on the triturating sur- 

 face. From the Miocene Tertiary of Oregon. 



