ILLUSTRATIONS. XI 



Page. 



Fig. 3. Postfrontal, with supraorbital horn core, of Monodonius recurvicornis Cope 5 



4. Occipital region of Monodonius recurvicornis 6 



5. Skull of type of Triceratops prorsus Marsh 15 



6. Occipital region of type skull of Triceratops flabellatus Marsh 16 



7. Occipital condyle of type of Torosaurus gladius Marsh 17 



8. Occipital region of skull of type of Triceratops flabellatus 17 



9. Occipital region of skull of type of Triceratops flabellatus 18 



10. Skull of type of Triceratops flabellatus, side view 18 



11. Skull of type of Triceratops flabellatus, back view 19 



12. Frill of type of Torosaurus gladius Marsh 20 



13. Parietal of type of Monodonius crassus Cope 20 



14. Squamosals of Torosaurus, Triceratops, and Ceratops 21 



15. Squamosal of type of Triceratops flabellatus 21 



16. Skull of type of Triceratops serratus Marsh, superior view 22 



17. Quadrate of type of Triceratops flabellatus 23 



18. Quadratojugal of type of Triceratops flabellatus 23 



19. Right nasal of type of Triceratops flabellatus 25 



20. Maxillary, palatine, and lachrymal of type of Triceratops flabellatus, internal view 26 



21. Maxillary, palatine, and lachrymal of type of Triceratops flabellatus, external view 26 



22. Maxillary of type of Triceratops flabellatus 27 



23. Left pterygoid of type of Triceratops flabellatus 27 



24. Cranium of type of Triceratops horridus 28 



25. Palatine region of type of Triceratops horridus 28 



26. Skull of Triceratops serratus Marsh, palatal view 29 



27. Vertical section through skull of Triceratops horridus (type) 30 



28. Left premaxillary of type of Triceratops flabellatus 31 



29. Nasal horn core of Triceratops prorsus 33 



30. Rostral of type of Triceratops elatus 33 



31. Horizontal section of brain case of type of Triceratops flabellatus ■ 37 



32. Brain cast of Triceratops serratus, inferior view 37 



33. Longitudinal section of skull of Triceratops flabellatus 3S 



34. Brain cast of Triceratops serratus, lateral view 39 



35. Predentary of type of Triceratops pirorsus 40 



36. Right dentary of type of Triceratops flabellatus 41 



37. Left splenial of type of Triceratops prorsus 41 



38. Left angular of type of Triceratops flabellatus 42 



39. Right surangular of type of Triceratops flabellatus 42 



40. Right angular, surangular, and articular of type of Triceratops prorsus 42 



41. Lower jaw of type of Triceratops prorsus 43 



42. Superior tooth of Triceratops serratus 43 



43. Vertical series of teeth from lower jaw of Triceratops flabellatus 44 



44. Inferior teeth of Triceratops flabellatus '. 45 



45. Sections through roots of incipient and growing teeth of Triceratops 45 



46. Superior and inferior teeth of Triceratops 45 



47. Section of maxillary of Triceratops, showing dental grooves 46 



.48. Presacral vertebral series of type of Triceratops brevicornus Hatcher 47 



49. Anterior cervical vertebrse of Triceratops prorsus ■. 47 



50. Anterior cervical vertebras of Triceratops prorsus .. .: 48 



51. Anterior dorsal vertebra of Triceratops prorsus 50 



52. Posterior dorsal vertebra of Triceratops prorsus 51 



53. Sacrum of Triceratops prorsus, inferior view 52 



54. Sacrum of Triceratops prorsus, side view 53 



55. Sacrum of Triceratops prorsus with ilia in position, superior view 54 



56. Spinal cord of sacrum of Triceratops prorsus 54 



57. First caudal of Triceratops prorsus i . . . 55 



58. Median caudal of Triceratops prorsus 56 



59. Distal caudals of Triceratops 56 



60. Pelvis of Triceratops flabellatus 56 



61. Right ilium of Triceratops flabellatus ; 57 



62. Left pubis of type of Triceratops flabellatus 57 



63. Ischia of Triceratops prorsus 58 



64. Left scapula and coracoid of Triceratops prorsus 59 



65. Humerus of Triceratops prorsus, anterior view 60 



