18. Palatal dart-head, and group of palatal teeth, of _Dipterus_ 83 19. Cranial buckler of _Dipterus_ 85 20. Base of cranium of _Dipterus_ 86 21. Under jaw of _Dipterus_ 87 22. Longitudinal section of head of _Dipterus_ 88 23. Section of vertebral centrum of Thornback 92 24. Dermal tubercles of _Asterolepis_ 95 25. Scales of _Asterolepis_ 96 26. Portion of carved surface of scale 96 27. Cranial buckler of _Asterolepis_ 98 28. Inner surface of cranial buckler of _Asterolepis_ 99 29. Plates of cranial buckler of _Asterolepis_ 102 30. Portion of under jaw of _Asterolepis_ 103 31. Inner side of portion of under jaw of _Asterolepis_ 104 32. Portion of transverse section of reptile tooth of _Asterolepis_ 105 33. Section of jaw of _Asterolepis_ 106 34. Maxillary bone? 108 35. Inner surface of operculum of _Asterolepis_ 109 36. Hyoid plate 110 37. Nail-like bone of hyoid plate 111 38. Shoulder plate of _Asterolepis_ 112 39. Dermal bones of _Asterolepis_ 113 40. Internal bones of _Asterolepis_ 114 41. Ditto 115 42. Ischium of _Asterolepis_ 116 43. Joint of ray of Thornback:—of _Asterolepis_ 117 44. Coprolites of _Asterolepis_ 118 45. Hyoid plate of Thurso _Asterolepis_ 124 46. Hyoid plate of Russian _Asterolepis_ 127 47. Spine of _Spinax Acanthias_:—fragment of Onondago spine 143 48. Tail of _Spinax Acanthius_:—of _Ichthyosaurus tenuirostris_ 172 49. Port Jackson Shark (_Cestracion Phillippi_) 177 50. Tail of _Osteolepis_ 195 51. Tail of _Lepidosteus osseus_ 196 52. Tail of Perch 197 53. _Altingia excelsa_ (Norfolk-Island Pine) 212 54. Fucoids of the Lower Old Red Sandstone 216 55. Two species of Old Red Fucoids 217