AND GREAT LIGNITE FORMATIONS OF NEBRASKA. 
145 
just mentioned, but its posterior margins are not crenated, and the intervening back sur¬ 
face is more elevated. The apex of the specimen is worn off in a sloping manner an¬ 
teriorly. This tooth I suspect to represent an incisor. 
As the entire dentition of Megalosaurus has not yet been ascertained, it may turn out 
to be the case, that in other parts of the jaws than those known, it possesses teeth like 
the ones above described as peculiar. Should on future discovery such a condition of things 
be proved to exist, Deinoclon would then cease to be any thing more than a second species 
of Megalosaurus. 
As anatomical and geological evidence favour the view that Iguanodon , Trachodon, and 
Eadrosaurus, were amphibious, i.t is not unlikely that Megalosaurus and Deinodon infested 
the shores, upon which the former quietly grazed or browsed, and proved to them fierce 
and destructive enemies. The two carnivorous saurians perhaps held the same office in 
relation to the more bulky herbivorous lizards, that we find to exist between the larger 
existing feline animals, and the pachyderm solipedal and ruminant mammals. 
Explanation of Figures, Plate 9. 
Figures 21—48, Teeth of Deinodon iiorridus; all the size of Nature. 
Figure 21,/. cj. Two fragments of a large sabre-shaped tooth; lateral view. 
Figures 22, 23. Transverse sections at the positions marked /. <j. 
Figure 24. Front view of the same fragments. 
Summit of a sabre-shaped tooth. 
Section at h. 
Summit of another specimen. 
Section at i. 
Lateral view of the summit of a sabre-shaped tooth, exhibiting the enamel partially worn off. 
Section of the tooth at j. 
A similar tooth. 
Section at 7c. 
A small tooth of the same form. 
Section at l. 
Fragment of a large tooth, with its posterior border forming a plane surface as indicated in the sec¬ 
tion, Figure 36, taken at m. 
Figure 37. Lateral view of the summit of a tooth like the preceding specimen. 
Figure 38. Posterior view of the same specimen. 
Figures 39, 40. Sections at n. o. 
Figure 41. Posterior view of the crown of a tooth, perhaps an incisor. 
Figure 42. Lateral view of the same. 
Figures 43, 44, 45. Sections from the positions indicated. 
Figure 46. Postero-internal view of a conical tooth. 
Figure 47. Antero-external view of the same specimen. 
Figure 48. Section atyj. 
Figure 25. 
Figure 26. 
Figure 27. 
Figure 28. 
Figure 29. 
Figure 30. 
Figure 31. 
Figure 32. 
Figure 33. 
Figure 34. 
Figure 35. 
