LIST OF ILLUSTRATIONS. 



FIG. PAGE 



1. Palceospondylus gunni. Restoration 2 



2. Cyathaspis sturi. Dorsal shield ...... 4 



3. banksi. Dorsal shield, external aspect ... 6 



4. Pteraspis rostrata. Dorsal shield, external aspect ... 7 



5. crouchi. Dorsal shield ...... 7 



6. rostrata. Restoration ...... 7 



7. Cephalaspis lyelli. Dorsal shield 9 



8. . Diagram of dorsal shield 10 



9. . Transverse section of dorsal shield ... 10 



10. murchisoni. Restoration : . . . .11 



11. Auchenaspis egertoni. Head and trunk 11 



12. Pterichthys milleri (testudinarius). Restoration . . .13 



13. Bothriolepis canadensis. Diagram of head-shield ... 14 



14. Supposed upper jaw plates . . 14 



15. hydrophila. Restoration 15 



16. Acanthaspis decipiens. Diagram of body-shield ... 16 



17. Pleuracanthus (Xenacanthus) decheni. Portion of caudal region 20 



18. Skeleton of anal fins . 21 



19. Holoptychius (Glyptolepis) leptopterus. Cartilages of dorsal fin 22 



20. Scaumenacia curta. Cartilages of anal fin . . .22 



21. Cladoselache. Pectoral and pelvic fins 23 



22. Pleuracanthus (Xenacanthus) decheni. Pectoral fin . . 24 



23. Eusthenopteron foordi. Pectoral fin 25 



24. Cladoselache fyleri. Restoration 31 



25. . Caudal fin 31 



26. Pleuracanthus (Xenacanthus) decheni. Restoration . . 34 



27. Acanthodes wardi. Restoration 35 



28. Climatiut scutiger. Outline showing spines .... 36 



29. Acanthodes wardi. Skeletal parts of pectoral fin . .37 



30. Diplacanthus striatus. Pectoral arch and fins . f . . 37 



31. Parexus falcatus. Skeletal parts of pectoral fin ... 37 



32. Hybodus polyprion, Notidanus daviesi, N. microdon, ^V. gigas. 



Outline of teeth 41 



62 



